α-alumina is used as the main raw material. The ceramic support is prepared by extrusion molding process, and the ceramic flat membrane for water treatment is prepared by the dip coating process. The effect of different sintering temperatures on the physical properties of the film is studied. The research shows that: 1) as the sintering temperature of the film increases, the pores on the surface of the film gradually decrease, the pore size of the film gradually becomes smaller, and the bonding strength between the film and the support gradually increases. 2) the ceramic membrane sintered at 1 250℃ has a best performance, with a porosity of 41.91%, a compressive strength of 17.96 MPa, good acid and alkali resistance, good film bonding strength, uniform pore size distribution, an average pore size of about 0.1 μm, and a pore size of more than 80%. Filtering experiment is performed on the alumina wastewater, by being treated by ceramic flat membrane, the impurity content in the wastewater can be reduced to 0.3 parts per 10 000, and the turbidity can be reduced to 0.11 NTU.

Glass fiber (GF) reinforced Polyamide 66 (PA66) composites are prepared by melt blending and injection molding. The effects of GF content on the mechanical properties and thermal deformation properties of the composites are studied, and the optimal ratio was selected. The results show that: when the GF content increases from 0% to 30%, the tensile strength, bending strength, bending modulus and impact strength of the composite increase by 78%, 71%, 108% and 260%, respectively, and the hot deformation temperature increases to 220℃; when the GF content continues to increase from 30%, the performance of the composite is not obviously improved, and the phenomenon of floating fiber is intensified, which affects the overall appearance of the product. Considering the practical application conditions and production cost, the optimal ratio of GF reinforced PA66 composite is GF content with 30%.

The graphene has a thermal conductivity of as high as 5 300 W/(m·K) and a specific surface area of as high as 2 630 m²/g, with excellent thermodynamic properties. In the heat dissipation of industrial computers, manufacture of graphene spray radiator was carried out: Graphene precursor material (Reduced Graphene Oxide, RGO) was prepared by the improved Hummer method, and processing methods such as diazotization and high-temperature reduction. Through mechanical mixing, the resin material was modified, and the graphene composite with high thermal conductivity was prepared. Graphene composite material was sprayed on the surface of the radiator by plastic spraying process, and the graphene sprayed radiator was obtained. Taking the HPC300 CNC system industrial computer as the test platform, the graphene sprayed radiator test was carried out and compare its sprayed effect against the anodized radiator and traditional aluminum extrusion radiator, further to evaluate the application effect. The test results show: 1) The heat dissipation performance of the graphene spray radiator is improved by 18.7% compared with traditional aluminum extrusion radiator and 9.6% compared with anodized radiator. 2) The spraying controllability of graphene spraying process is higher, which can better meet the requirements of electrostatic design. 3) Under the same heat dissipation design requirements, the graphene spray radiator is lighter and smaller, which is suitable for working in high-frequency vibration environment and has higher safety.

Capturing CO₂ by solid adsorbent is one of the most effective means in CO₂ capture and storage technologies. Using fly ash and slag as raw materials, solid waste base geopolymer composite porous materials with developed pore structure were prepared by alkali activator, foaming agent and foam stabilizer. Orthogonal experiments were used to optimize the ratio of composite porous materials, and the geopolymer composite porous particles with compressive strength of 15.395 N and CO₂ adsorption capacity of 156.28 cm³/g were prepared. On the basis of the optimized scheme, 3 different types of zeolites, namely, 13X molecular sieve, 4A molecular sieve and clinoptilolite, were added into geopolymer matrix to prepare zeolite-geopolymer composite porous materials. After adding zeolites, the compressive strength decreases, but the specific surface area and pore volume increase, and the CO₂ adsorption performance is obviously improved. Among them, the performance of the composite porous material with 13X zeolites is the best, and its CO₂ adsorption capacity reaches 602.43 cm³/g, which is about 3.2 times higher than that of the composite porous material without zeolites.

The parameters of alumina fiber prepared by sol-gel method during heat treatment were discussed. The changes of fiber volume, weight and crystal form at different heat treatment temperatures and rates were investigated by thermogravimetric analysis, crystal form analysis and micromorphology analysis. Findings: 1) Below 550℃, the mass and volume of the fiber shrink sharply, and the shrinkage rate is higher than 85%. 2) The weak γ-Al₂O₃ crystal phase appears in alumina fiber at 800℃, and the γ phase becomes stronger and stronger with the increase of temperature, and it turns into Mullite phase at 1 275℃, and the transition of Mullite phase becomes stronger at 1 300℃. 3) The heat treatment rate of the fiber has a great influence on the properties of the fiber, so a lower heating rate should be selected in the heat treatment process.

SnS₂ is considered as one of the most potential anode materials due to its high theoretical lithium storage capacity, but with poor cycle stability and rate performance. SnS₂ nanoparticles/MXene composite (SnS₂ NPs@MXene) was prepared by an in-situ confinement solvothermal method, in which SnS₂ nanoparticles are uniformly embedded in the MXene layers in a sandwich structure. SnS₂ NPs sandwiched between MXene can inhibit the stacking of MXene and relieve the volume strain of SnS₂ NPs. As an anode of lithium-ion batteries, SnS₂ NPs@MXene composite electrode has high reversible capacity, excellent rate performance and long-term cycling stability under high current density. The reversible capacity is 931 mAh·g^-1 after 200 cycles at a current density of 0.1 A·g^-1. The reversible capacity is as high as 566.5 mAh·g^-1 at a current density of 5 A·g^-1. The reversible capacity remains at 646 mAh·g^-1 at 2 A·g^-1 after 2 000 cycles. It is of great significance that the synthesis method of SnS₂ nanoparticles/MXene composite is also applicable to other two-dimensional layered metal sulfide nanoparticles/MXene composite, as well as two-dimensional layered metal sulfide nanoparticles/two-dimensional materials.

Laser cleaning technology is a kind of technology which can efficiently remove the scale on the surface of superplastic titanium alloy, and has potential application in the aviation field. Establish the cleaning effect evaluation factors such as clean coverage, design experimental scheme, and investigate the influence of cleaning mode, power, speed and times on the cleaning effect. It is found that: 1) Compared with the sweep cleaning mode, the fixed-point cleaning mode can more quickly achieve higher clean coverage. 2) The higher the cleaning power and cleaning speed, the better the cleaning effect. The cleaning times can compensate for the influence of the lower cleaning power and cleaning speed to a certain extent, but it will form defects such as dark spots and corrosion on the surface of superplastic titanium alloy. 3) Cleaning the same position for too many times will lead to light yellow oxidation color on the surface of superplastic titanium alloy. Factors such as mode, power, speed and frequency have cross influence on the cleaning effect of scale on the surface of superplastic titanium alloy, which should be weighed in practical application.

In order to reduce the maximum temperature gradient and the maximum curing degree gradient in the curing process of composite materials and improve the molding quality of composite structural parts, a synergistic control method of curing temperature and curing degree of composite materials based on temperature curve optimization was proposed. The analysis model of curing process of composite materials was built, and the model accuracy was verified by taking AS4/3501-6 composite plate structure as an example. The test sample points were selected, the test samples were established, the generalized regression neural network was trained and tested, and an approximate model of the curing process of composite materials was established. Grey correlation analysis and response surface method were used to optimize the approximate model, and the optimized design variables, as well as responses of maximum temperature gradient and maximum curing degree gradient were obtained. The analysis of the optimization results shows that compared with the original design, the maximum temperature gradient and the maximum curing degree gradient after optimization have decreased by 54.93% and 13.27%, respectively. The proposed synergistic control method has remarkable effect in multi-objective and non-uniform optimization of the curing process of composite materials.

Using hydrophobic white carbon black particles, fluorocarbon paint and acetone as raw materials, the preparation scheme of composite super-hydrophobic coating is proposed, and the feasibility of its application in the metal corrosion protection is evaluated. By controlling the mass ratio of raw materials, hydrophobic white carbon black particles are dissolved in the acetone solution to prepare the white carbon black self-assembly dispersion, which is used as the surface layer; the spin coating method is used to improve the hydrophobicity of fluorocarbon paint body by using white carbon black as the bottom layer. The white carbon black-fluorocarbon paint composite super-hydrophobic coating with micro-nano rough structure is obtained through the process design concept of such a “surface-bottom” combination. The results show that when the mass ratio of white carbon black to acetone solution is 0.025 and the mass ratio of white carbon black to fluorocarbon paint is 0.3, the contact angle of the composite coating can reach 152° and the rolling angle is less than 5°, which reflects an excellent super-hydrophobic effect. In the indoor environment, the steel plate is subjected to atmospheric natural exposure corrosion test for 1 year, and the coating shows excellent anti-corrosion effect. The super-hydrophobic mechanism of the coating is analyzed, showing that the design of “surface-bottom” combination can prevent the water from long-time staying and lasting erosion on the metal surface, and block the interaction of three elements (anode, cathode and corrosion medium) of metal electrochemical corrosion, forming a closed-loop effect for the metal corrosion protection.

The layout of grounding connection in the vehicle chassis structure can effectively ensure the vehicle to meet the objectives including electromagnetic compatibility, but the anti-corrosion design of chassis is a difficulty. Based on the analysis and test of the existing common grounding structure, three optimized structures are designed, and the cyclic dynamic corrosion test is carried out by using the test sample piece, and the anti-corrosion effect is verified by measuring the coating thickness. After three rounds of iterative optimization, the obtained structure is the process bolt with flange, and the height of the boss at the opening of the threaded hole of 2.2 mm, which meets the chassis anti-corrosion requirements. Verified results show that, the blistering level is optimized from B3 to B0, the corrosion level is optimized from Ri5 to Ri0, the average coating thickness is increased from 0.6 μm to 54.8 μm, and the coverage protection ratio of metal body at thread joint is increased from 50% to 100%. The corrosion test verification of the formal subframe also meets the anti-corrosion target requirements. The analysis and judgment show that the main causes of corrosion of grounding structure in chassis environment include: the zinc coating is damaged by acid pickling, the sealing performance is insufficient due to insufficient structural pressing force, and the coating is torn off when dismantling process bolts/nuts, which should be paid attention to in similar anti-corrosion design, as to enhance the quality of chassis.

The performance of lubricating greases is the key to ensure the service life of wire ropes. By studying on the physical and chemical properties of 7 common lubricating greases for wire ropes, the physical and chemical indexes of 7 lubricating greases, such as ash, residual carbon, moisture, specific gravity, viscosity, water resistance, oxidation resistance and corrosion resistance were determined, and the quality and function of lubricating greases were compared by auxiliaries of chart and observation. Findings: 1) According to the results of composition determination, lubricating greases with few impurities and caking resistance are KL-90, KL-70 and XT-70, lubricating greases with carbon deposition resistance are CH-1, IRIS655 and A19-200, and lubricating grease with the best low-temperature fluidity is XT-70. 2) From the measurement results of physical properties, 7 lubricating greases have little difference in fluidity and water resistance, in which KL-90 is the lubricating grease with wide applicable temperature. 3) According to the measurement results of chemical properties, the lubricating grease with the best oxidation resistance and corrosion resistance is both IRIS655. The intrinsic relationship between the physical and chemical indexes of different lubricating greases was analyzed, and the applicability of various lubricating greases in different environments was ascertained.

The alloy coating is prepared on the surface of Q235 steel substrate with Ni60A alloy powder as cladding material. The effects of laser power on the microstructure, microhardness and wear resistance of Ni60A alloy cladding layer are investigated by single factor comparison experiment. It is found that: 1) Under three laser powers (2.5 kW, 3 kW, 3.5 kW), crack-free coatings can be formed, and dendrite is the main microstructure; 2) Under low power, the dendrite size in the cladding layer is smaller, the average microhardness is higher, the average friction coefficient is lower, and the wear resistance of the material is higher; 3) Under the laser power of 2.5 kW, the highest hardness of cladding layer is 4.6 times that of substrate, and the friction coefficient is small, which can most effectively improve the surface hardness and wear resistance of low carbon steel.

Started from the indexes such as chromaticity, acid value, emulsion resistance, rotating oxygen bomb value, paint film tendency index (MPC value), sediment (sludge and n-pentane insolubles), the new turbine oil and the running turbine oil of a power plant were taken as samples, to carry out the open cup aging test and infrared spectrum test, and thus, the correlation between the antioxidant performance and the oxidation stability of turbine oil was judged, and the evaluation indexes of oxidation stability were determined. Findings: all indexes of antioxidant performance are positively correlated with oil aging time and oil oxidation degree; rotating oxygen bomb value and paint film tendency index should be taken as the main evaluation indexes of oxidation stability of turbine oil together with the acid value and sediment mentioned in Glossary on Electric Power Oil (DL/T 419—2015); the precipitated sludge produced after oil aging contains carbonyl compounds and ester-based compounds, so the sludge and other sediments should be removed in time at the initial stage of oil oxidation to avoid the accumulation of aging products and the production of macromolecular sludge.

In order to give full play to the high temperature resistance of Nb-W alloy substrate and promote its application in the thrust chamber of attitude and orbit control engine in an aerospace, a multi-element co-infiltrated molybdenum silicide coating is prepared on the surface of Nb-W alloy by vacuum ion plating and multi-element silicidation treatment. By analyzing the forming process and failure mechanism of multi-element co-infiltrated molybdenum silicide coating, the high-temperature oxidation resistance mechanism is clarified, and its application feasibility is confirmed. It is found that: 1) The coating structure consisting of coarse columnar crystals MoSi₂, fine columnar crystals NbSi₂ and Nb₅Si₃ is formed by the vapor diffusion of silicon in the process of multi-element co-cementation; 2) Multi-element co-infiltrated molybdenum silicide coating can form SiO₂ glass film with self-healing ability at high temperature to isolate oxygen, and its failure process is essentially a process of silicon consumption; 3) The high temperature oxidation resistance life of MoSi₂→(Nb, Mo)Si₂→Nb₅Si₃ coating formed by molybdenum plating and siliconizing on the surface of Nb-W alloy is better than that of MoSi₂ coating directly formed on the surface of molybdenum substrate.

According to the lightweight requirements of aerospace equipment, the casting process of Mg-Y4-Nd2-Gd1 series high-performance heat-resistant magnesium alloy is studied based on the development of a transition cabin shell casting. Technological schemes including melting, casting and heat treatment are analyzed, the design principles of parameters such as shrinkage are put forward, and the casting simulation is carried out. According to the simulation results, the causes of casting defects are analyzed and identified, and the optimization measures such as changing the gating system to 3° taper and appropriately increasing the filling speed are put forward. The optimized indexes are proposed, the secondary simulation is carried out, showing that the optimization measures and casting schemes have a good improvement effect. The optimized scheme is applied to production verification, and the qualified rate of castings reached 75%, achieving the following goals: 1) The tensile strength at room temperature reached 300 MPa and the elongation reached 3%; 2) At 250℃, the tensile strength reaches 230 MPa and the elongation reaches 5%. It lays a foundation for batch production of high-performance heat-resistant magnesium alloy castings.

To report the challenges brought by the coupling extent between the fluid and solid interfaces on the additive manufacturing technology. On the basis of a model, i.e., a fluid column surrounded by the infinite isotropic solid, the acoustic equation satisfied by the fluid, the elastic wave equation satisfied by the solid and the coupling boundary conditions between the fluid and solid interfaces are established in the angular-frequency-wavenumber domain. By introducing the concept, i.e., fluid-solid coupling degree, the fluid-solid interface incomplete coupling boundary conditions with slippery normal displacement, slippery normal stress and zero tangential stress are derived, and the dispersive characteristics and waveform characteristics excited by the monopole sources with different center frequencies are investigated. The coupling between the fluid column and the hard solid reduces the cut-off frequency and suppresses the propagation velocity of all modes; when the coupling degree of normal displacement or normal stress increase, the modes become far away from or close to the cases when the periphery of the fluid column is not contacted with the hard solid, respectively. The coupling between the fluid column and the soft solid only generates the 0^th order mode of dispersive wave with a relatively low cut-off frequency; when the coupling degree of normal displacement or normal stress decrease, the 0^th order mode becomes far away from the cases when the periphery of the fluid column is not contacted with the soft solid, and the cut-off frequency continues decreasing or even disappears, which may further lead to the reversal of the 0^th order mode. When the coupling degree of normal stress is zero, the generated wave series with complexity is not a certain mode in the dispersive curve, but some other kind of non-dispersive wave. The “Hysteresis P-wave” retained in the fluid column and the propagation characteristics nearly same as the case when the fluid column is surrounded by the transversely isotropic solid are the special mathematical and physical phenomena when the fluid column is coupled with the soft solid.

Nessler's reagent spectrophotometry is the first detection method recommended and applied by national environmental protection standard HJ 535-2009, which is widely used in relevant fields of water quality monitoring. According to the Regulations of the People's Republic of China on Certification and Accreditation and relevant regulatory requirements, method verification must be carried out before standard methods are used. According to HJ 535-2009, the method was verified by the processes of standard series solution preparation, standard curve establishment, determination condition optimization, detection limit test, precision test and recovery test. The results show: 1) The best test conditions of this method are: pH=7~8, color development temperature is 25℃ and standing time is 10~20 min. 2) The linear range of the method is 4.52×10^-4~0.10 mg, the detection limit is 1.13×10^-4 mg/L, and the detection limit is 4.52×10^-4 mg/L. 3) The precision of the method is high, the RSD is in the range of 1.10%~4.23%, and the recovery rate is in the range of 97.89%~103.33%.

Based on the structural characteristics and technological quality requirements of ZM6 magnesium alloy thick and large cylindrical casting, the development process of casting is studied. Aiming at solidification sequence control, technologies such as differential pressure casting and gravity casting are combined to carry out numerical simulation optimization and comparison, and the cold iron with thickness of 20 mm is surrounded in the middle of the vertical cylinder to increase the temperature gradient of the casting from bottom to top and shorten the solidification crystallization time of the casting. According to the flame retardant design, the mass ratio of talc powder, sulfur and boric acid in the coating is adjusted from 8:1:1 to 6:2:2, and the near liquidus pouring is introduced to realize effective flame retardant. Research result: the ZM6 magnesium alloy thick and large cylindrical casting with mechanical properties and internal quality meets the technological requirement index of Class Ⅱ casting in HB 7780-2005.

Welding deformation and residual stress of austenitic stainless steel hull structure will cause risks such as corrosion cracking. The MSC.MARC nonlinear finite element analysis software is applied to carry out the thermal elastic-plastic study. Focusing on 5 typical welding joints of hull structures fabricated by austenitic stainless steel, the welding deformation and residual stress of test plates with different sizes and various thermal inputs are studied. The study reveals that, 1) the magnitude and distribution of welding deformation and residual stress in the test plate are significantly affected by heat input. Basically, the welding stress of typical joints has increasing trend along with the enhancement of heat input. The peak values of transverse stress and longitudinal stress of butt joints are more sensitive to the increase of heat input, and the maximum increase can reach 37.8%. The Mises stress increases more obviously in the T-joint, and the maximum increase can reach 11.6%. 2) The welding deformation of typical joints shows different trends with the increase of heat input. The total deformation of butt joints increases with the enhancement of heat input, while that of T-joints decreases. Conclusion: if attention is paid to on the control of heat input during butt welding in the construction of austenitic stainless steel hull structure, excessive welding deformation and residual stress can be avoided.

Coastal cities in southern China are densely populated and humid with buildings and communication networks, and the communication cables in distribution networks are easily affected by rats. Considering geomorphological environment, anti-rat performance, safety, reliability and construction convenience, a new type of nonmetallic armored anti-rat pipeline optical cable with glass fiber bundle is developed. Its structural and protect design is carried out, tests such as tensile, flattening, impact, torsion, bending are used for mechanical performance test. Technological performance indicator test shows that the optical fiber signal has no obvious additional attenuation, and the sheath has no visible cracking; the flame retardant performance is tested by single vertical combustion test, showing that the combustion distance is within the range of relevant standards; the anti-rat performance is tested by direct rat bite method, showing that the structures such as internal cable core armor can prevent the bitten by rats, and the optical cable is fully protected. After engineering application, the optical cable has good rat prevention effect, which provides theoretical and technological support for the construction of strong power grid.

The FGH97 alloy has excellent comprehensive mechanical properties at high temperature, but fatigue fracture may still occur after long-term exposure to high temperature and stress. Taking an FGH97 alloy turbine disk as the research object, the high temperature oxidation test of FGH97 alloy is designed, the high temperature oxidation process is simulated; with the oxidation proportion of Ti and Cr in FGH97 alloy as the analysis factor, the working temperature of the FGH97 alloy turbine disk is deduced when it has rupture failure. It is found that: 1) When the temperature is lower than 800℃, the oxidation of Ti in FGH97 alloy is dominant; when the temperature is higher than 800℃, the oxidation of Cr plays a dominant role. 2) The highest service temperature of the FGH97 alloy turbine disk is about 1 000℃. At this temperature, the γ' phase in the source region has no overheating and overburning phenomena such as bonding growth, remelting and secondary precipitation.

An innovative coprecipitation method was proposed to prepare inorganic solid electrolyte of garnet-structure lithium-ion battery: Al-Mg double-doped lithium lanthanum zirconium oxide (Li_6.4Al_0.2La₃Zr_2-0.5xMg_xO₁₂). Thermogravimetric analysis (TG), differential scanning calorimeter (DSC) and X-ray diffraction (XRD) were used to analyze the composition and phase transition of the sample precursor during heating. The optimum sintering temperature, sintering time and magnesium doping amount x were investigated, and the dependence between lithium-ion conductivity and temperature was further analyzed. Findings: 1) When the sintering temperature reaches 630℃, lithium lanthanum zirconium oxide can be formed; 2) The best sintering temperature is 1 100℃ and the best sintering time is 6 h; 3) When the magnesium doping amount x is 0.1, the ionic conductivity of prepared Li_6.4Al_0.2La₃Zr_1.95Mg_0.1O₁₂ at room temperature of 25℃ is 1.93×10^-4 S/cm, and the activation energy is 0.271 eV. The Al-Mg double-doped lithium lanthanum zirconium oxide with the most complete cubic crystal structure, the least impurity phase, the largest approximate density, the smallest interface resistance, the highest ionic conductivity and the smoothest and complete surface morphology is prepared.

An innovative liquid phase oxidation modification process of diamond particles by introducing strong oxidant KMnO₄ and strong oxidizing inorganic acid was put forward. X-Ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Ray (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and the quantitative determination of surface functional groups of diamond by succinimide ester with fluorescent molecules, were used to investigate the effect of oxidation time on the oxidation effect of diamond particles, and the changes of diamond structure under the optimal process parameters were further investigated. Findings: 1) the matrix structure and surface morphology of the diamond treated by liquid phase oxidation have not changed significantly, but the oxygen content has increased significantly, and the oxygen content can be increased from 9.42% to 11.87%, with an increase of about 25%. 2) The increased oxygen element probably exists on the diamond surface in the form of carbonyl groups, and the amount of newly added carbonyl groups can reach 3.4×10¹³ cm^-2.

The research and monitoring of the service life of the plastic tiles is a key issue to promote the giant and intelligent development of the hydroelectric generating units. Taking the elastic metal plastic tiles with single layer powder and double layer powder as the research object, the differences between them were compared from the aspects of appearance, friction and wear properties, mechanical properties and insulation properties, etc. It is found that the composites with single layer powder and double layer powder both have good friction, wear and insulation properties. Compared with composites with single layer powder, the bending fatigue properties of composites with double layer powder are improved by about 40%, the peeling shear strength of plastic layer is increased by more than 20%, and the peeling shear strength of brazing layer is increased by about 5%. By observing the colour changes of the working layer and the bonding layer of the elastic metal plastic tile with double layer powder, it can effectively determine whether the service life of the tile is terminated. On the basis of elastic metal plastic tile with double layer powder, sensors are added to form an intelligent thrust tile, which is applied to the 1# unit of Hongjiadu Hydropower Station and has been in good operation for several months, indicating that it can be widely used in hydroelectric generator units.

The traditional g-C₃N₄ photocatalytic materials have some problems such as high recombination rate of photo-generated electrons and holes, low utilization rate of visible light, low quantum efficiency, small specific surface area and large internal resistance. Their photocatalytic performance is poor. By using a series of methods such as calcination and hydrothermal reaction and taking the g-C₃N₄ nano-sheets as the substrate, different contents of CdS were compounded with the g-C₃N₄ nano-sheets, and the CdS/g-C₃N₄ photocatalytic composites with different ratios were prepared by up-conversion and heterojunction construction. Characterizing instruments or methods such as scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet-visible spectrophotometer and BET were used to investigate the composition, micro-morphology, specific surface area and photocatalytic properties of photocatalytic composites. Rhodamine B was regarded as a pollutant, and its degradation performance under visible light was analyzed. It is found that the 7% CdS/C₃N₄ photocatalytic composites are superior to the 5% CdS/C₃N₄ photocatalytic composites and the pure g-C₃N₄ nano-sheets in the degradation of rhodamine B. Such a result show that the mechanism of up-conversion and heterojunction construction can effectively reduce the recombination rate of photo-generated electrons and holes, improve the utilization rate of visible light, and thus improve the photocatalytic rate of materials.

On the basis of the theory of "multiple energy dissipation mechanisms commonly dissipate energy", a new SMA-Friction Compound Damper (SFCD) was developed by improving the design of friction damper using the Shape Memory Alloys (SMA) material. The structure and working principle of SFCD were described in detail, and the test specimens were manufactured. The mechanical properties of dampers under different displacement amplitudes and loading rates under cyclic loading are studied through uniaxial tension-compression cyclic tests, and the time history analysis of eight-story steel frame structures without and with SFCD was carried out. The results show: 1) SFCD has a strong displacement correlation under uniaxial tension-compression cyclic loading, and the unit cyclic energy consumption can increase from 41 159.0 N·mm when the displacement amplitude is 3 mm to 217 241.2 N·mm when the displacement amplitude is 12 mm. 2) SFCD can combine the high energy dissipation characteristics of SMA with the traditional friction energy dissipation form. Under different loading rates, the energy dissipation variation of damper is only 4.0%, which is less disturbed by loading rate, and has stable hysteretic performance and good energy dissipation performance. 3) SFCD controls the overall displacement and residual displacement of the structure better than velocity and acceleration. Under the selected seismic waves, the displacement control of the first floor and top floor of the steel frame structure is above 55%, and the maximum damping rate is 70.26%. Generally, the application of SFCD can achieve remarkable earthquake absorption effect under strong earthquakes.

The curing process of fiber reinforced resin matrix composite materials is affected by material system (such as resin type and volume content, fiber type, etc.) and curing system (such as curing equipment, curing pressure, curing temperature rise and fall rate, curing mold type, etc.), which will cause cured deformation at the macro level and affect the surface accuracy of composite material parts. A simulation prediction method on cured deformation based on macro linear shrinkage was proposed. Under certain conditions of material system and curing system, all physical and chemical variables were treated by constant treatment, which could be summed up as the ratio of the length change in X, Y and Z directions to the length before curing. The finite element simulation model was established to predict the cured deformation results of C-type specimens with symmetric and asymmetric laminates, and the results were compared with the actual scanning results. The results show that the maximum relative error of the simulation prediction results is 10.68%, and the average relative error is 3.59%. The prediction accuracy can meet the needs of engineering practice, greatly reducing the difficulty of cured deformation prediction, and can play a practical guiding role in mold compensation surface design and cured deformation control of parts.

The erosion of coal particles and the corrosion caused by the blackwater vaporization have adverse effects on the service life of blackwater angle valve. The Co112 hard metal was deposited on the surface of F22 seal of blackwater angle valve by plasma transferred arc welding, and the effects of surfacing layers on the microstructure, element distribution and Vickers hardness were investigated. Findings: 1) The second surfacing is subjected to a heat treatment on the basis of the first surfacing, the eutectic composition ratio is higher than that of the first surfacing, the dendrite structure is refined, and there is an obvious microstructure transformation zone at the junction. 2) There is a columnar structure near the fusion line, which is dominated by Cr element. After surfacing two layers, the content of Cr element in the first surfacing layer increases. 3) Compared with the surfacing layer, the average and maximum microhardness of the surfacing layers are increased by 11.6% and 8.1%, respectively. Further analysis shows that the second surfacing plays the role of solid solution strengthening and fine grain strengthening, and the “second toughness” of the surfacing improves the performance of the first surfacing layer, which makes the blackwater angle valve better meet the service requirements.

In the R&D of membrane technology, loess/powder ash based ceramic membrane support can better meet the needs of low cost material development and high value added application of water treatment process. Equipment and methods such as Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD) and thermogravimetric analysis (TG-DTG) were used to study the influence of sintering system indexes such as sintering temperature and temperature holding time on the macro-performance (water flux, flexural strength, acid-base corrosion rate, etc.) and micro-performance (micro-section, phase change, thermal effect, etc.) of the support. The results show: 1) During the sintering process, the increase of sintering temperature has a negative effect on the water flux of the support, and the minimum is 2 166.18 L·(m²·h·MPa); the bending strength has a positive influence, and the maximum is 50.03 MPa; micro-crystal forms such as Mn₂AlO₄ and Al₂(SiO₄)O are formed in the sintering process, which can effectively improve the mechanical properties of the support. 2) When the sintering temperature is 1 050℃ and the temperature holding time is 3 h, the macroscopic shape of the support is relatively flat, and the neck connection is formed between grains, and the water flux, flexural strength and acid-base corrosion rate are maintained at a high level.

In order to identify diamonds scientifically, accurately and quickly, and to enhance the completeness of the diamond identification technology system, professional identification instruments or equipment such as gem microscope, polarizer, fluorescent lamp, infrared spectrometer and ultraviolet-visible optical fiber spectrometer were used to carry out the experimental design to detect and compare the natural diamond and its analogues. Findings: 1) The natural diamond and the HTHP synthetic diamond have sharp facets, high hardness, different levels of clarity and color; the synthetic cubic zirconia and the synthetic silicon carbide have smooth facets and low hardness; the synthetic silicon carbide can be seen with double facets. 2) Under polarizer, the natural diamond, the HTHP synthetic diamond and the synthetic cubic zirconia show optical characteristics of isotropic body, while the synthetic silicon carbide shows the opposite. 3) The infrared spectrum and the ultraviolet-visible optical fiber spectrum show that the characteristic absorption peaks of the natural diamond are completely different from those of its similar products. Using a variety of instruments, equipment and methods to test the diamonds and similar products can achieve the effect of mutual verification and get accurate and reliable diamond identification conclusions.

Taking a ZL114A special-shaped thin-wall bracket casting as the research object, the casting process research was carried out. The principles to be followed to ensure the internal quality of ZL114A alloy castings were put forward, and the casting process flow covering gating system design, cold iron layout, simulation, sand mold 3D printing, metal melting and gating parameter design was put forward. Novacast software was used to simulate the filling and pouring process of castings, showing that the design and placement of the end chills are beneficial to realize the principle of sequential solidification of castings and can effectively reduce the occurrence of loose defects. Meanwhile, the quality of alloy liquid can be effectively improved by controlling the alloy composition in the smelting process, increasing grain refiners and refining with argon gas. The technological parameters of the differential pressure casting process were determined, and it is proved by X-ray nondestructive testing that the castings meet the Class I casting standard in the aviation industry standard Specification for Aluminum Alloy Castings (HB 963-2005) and meet the internal quality requirements of finished products.

The wire materials of metallographic microstructure of Ti-3Al-4.5V-5Mo(TC16) titanium alloy were observed, and the effects of solution aging heat treatment on the microstructure and mechanical properties (tensile properties and impact properties) of TC16 titanium alloy were investigated. Findings: 1) After solution heat treatment, there are a large number of primary α-phases, metastable β-phases and α″-phases in the microstructure of the wire materials. With the increase of solution temperature, the content of primary α-phases decreases until it disappears completely, and more α″-phases are formed. After aging heat treatment, transformation structure of β-phases appears in the wire materials, and the morphology and size of primary α-phases changed little. 2) Under the condition of solid solution, the tensile strength of wire materials decreases with the increase of temperature, but the plasticity changes little with the increase of temperature. After aging heat treatment, the strength of the wire materials increases and the plasticity decreases, among which the maximum tensile strength is 1 280 MPa, the maximum yield strength is 1 182 MPa, the maximum elongation after fracture is 25%, and the maximum area shrinkage is 58%. 3) Under the condition of solid solution, the impact toughness and impact absorption energy of the wire materials increase with the increase of temperature. After aging heat treatment, the impact toughness and impact absorption energy both decrease, with the maximum impact toughness of 89 J/cm² and the maximum impact absorption energy of 36 J.

Mo/Al/B₂O₃/diamond powder was used as a thermal explosion reaction system to form a coating on the surface of diamond particles. The phase compositions of the thermal explosion reaction products and diamond particles were studied by X-ray diffraction (XRD), and the micro-morphology of diamond particles was observed by scanning electron microscope (SEM). Results and Findings: The thermal explosion reaction products are easy to be crushed and the diamond particles are easy to be separated from the bonding agent. With the increase of diamond content, the sample expansion gradually intensifies; under the protection of high-purity Ar gas, the matrix will form a material with MoAlB as the main phase. The thermal explosion reaction will form a multi-component coating composed of Al, Mo₂C, Al₂O₃ and AlMo₃ on the diamond surface; the coating is composed of a large number of grains with an average particle size of 2 μm. Generally, when the diamond content is low (10% and 20%), the surface of diamond particles in the products is well coated.

By combining with sol-gel method, bionic TiO₂ was prepared by using rice straw as the biological template. Aiming at the catalytic degradation of methylene blue, the preparation process optimization strategy and photocatalytic activity of bionic TiO₂ were investigated. Findings: the degradation rate of methylene blue is over 93% when the rice straw powder doping amount is 1.75 g, the calcination temperature is 500℃, the calcination time is 5 h, and the sunlight is irradiated for 30 min. The bionic TiO₂ samples were characterized by field emission scanning electron microscopy, X-ray diffractometer, X-ray photoelectron spectroscopy and UV-visible spectrophotometer. Results: 1) the bionic TiO₂ replicates the multi-layered three-dimensional structure of rice straw, increases the specific surface area, and realizes the doping of elements such as N and P; 2) in the bionic TiO₂, a new impurity energy level is formed, the band gap is narrowed by 0.04 eV, and the light absorption sideband is red-shifted, by which its photocatalytic performance is further improved.

Taking 15-5PH stainless steel samples as the research object, firstly, hot-dip aluminizing process of stainless steel was implemented, and then, hard anodic oxidation of aluminum alloy was carried out using polytetrafluoroethylene (PTFE). The surface properties of anodic oxide film obtained under different experimental conditions were investigated. Findings: the hot-dip aluminized film and the anodic oxide film are firmly bonded to the substrate with good bonding strength after repeated heating and chilling as per the thermal shock test (GB/T 5270—2005); silicon content of 6%, hot-dip aluminizing temperature of 630℃ and hot-dip aluminizing time of 2 min can be used as the ideal process parameters for the hot-dip aluminizing of stainless steel, and a hot-dip aluminizing layer with a thickness of 15 μm can be obtained; the PTFE-A1₂O₃ oxide film obtained by adding PTFE nano-emulsion for hard anodic oxidation has better chemical stability and thermal stability than the common A1₂O₃ oxide film; when the content of PTFE nano-emulsion is 25%, the self-lubricating property of PTFE-A1₂O₃ oxide film is the best.

Gear steel is a kind of steel used to manufacture gears, and the inclusion level in the gear steel is a key factor affecting the life of gear. Taking 20CrMnTiH gear steel as the research object, a control hierarchy including hot metal pretreatment, converter smelting, LF refining, vacuum degassing (VD) and billet continuous casting was formed. Firstly, the end temperature of converter was adjusted from 1 660℃ to 1 620℃, and the end carbon content was adjusted from 0.03% to 0.08%, so that the oxygen content in the steel was reduced from 0.092% to 0.034%. Secondly, optimized was the refined slag system, adjusted were the content of calcium oxide (from 62%~66% to 55%~60%), aluminum oxide (from 25%~31% to 32%~36%) and silicon dioxide (from 6%~10% to 4%~9%). Thirdly, in the vacuum degassing process, the vacuum time was extended from 12 min to 18 min, which promoted the removal of elements such as hydrogen and oxygen. Fourthly, in the process of billet continuous casting, protective casting measures were taken to avoid the contact between molten steel and air, and avoid the inclusion caused by secondary oxidation. The trial-production results show: Class A fine inclusions are reduced from Grade 2.0 to Grade 1.0, and coarse inclusions are reduced from Grade 1.0 to Grade 0.5; Class D fine-grained inclusions are reduced from Grade 1.5 to Grade 1.0, and coarse-grained inclusions are reduced from Grade 1.0 to Grade 0.5. The finished products can meet the requirements of high-quality varieties

Alumina powder with average particle sizes of 10 μm and 5 μm is used as the main raw material. Through particle gradation, a ceramic support with a narrow pore size distribution is successfully prepared, and the effect of particle gradation on the support-related properties is studied. The research shows that as the proportion of 5 μm alumina powder increases, the porosity of the ceramic support decreases, the compressive strength increases, the average pore diameter decreases, and the gas flux decreases accordingly; when the mass ratio of 10 μm alumina to 5 μm alumina is 1:1, the distribution of the pore diameter is the narrowest, the porosity of the support is 43.5%, the compressive strength is 25.8 MPa, the average pore diameter is 0.6 μm, and the gas flux is 21.9 m³/(m²·h) (△P=0.1 bar).

There is easy to suffer severe corrosion on the blade root of blast furnace gas residual pressure turbine power generating system (TRT) during operation. The sealants on the market are surveyed, and a silicone rubber coating whose construction time is between 0.25~0.5 h, curing time is more than 1 h and is resistant to saturated NH₄Cl corrosion is primarily selected. The applicability of such a silicone rubber coating is evaluated by analyzing its physical and chemical properties, corrosion resistance and actual adhesion. The study shows that: 1) In terms of physical and chemical properties, the surface drying time of the coating is 40 min, and its actual drying time is 100 min; its wet film thickness is 215 μm and its dry film thickness is 146 μm; the non-volatile content of the coating is 97 wt% and 85 vt%, respectively; the flexibility of the coating is good when it is cured; 2) In terms of corrosion resistance, even if the coating is prepared into tensile lap-shear specimens and immersed in saturated NH₄Cl solution at 100℃ for 30 d, the color of the coating still do not change, the failure method between coating and test board are both adhesion damages, and the tensile shear strength slightly decreases from 1.13 MPa to 1.09 MPa; 3) In terms of actual adhesion, if the coating is applied in the blade root and the groove, and then the blade root is pushed out from the groove after the coating is cured at room temperature, the coating could cover 80% of the blade roots surface, which can considerably protect the metal substrate. In conclusion, the selected silicone rubber coating meets the requirements of TRT working conditions and could be used as the anticorrosive coating for the blade roots of TRT.