The Li₂ZnTi₃O₈@polyaniline (LZTO@PANI) composite materials were prepared by sol?gel and chemical oxidation polymerization methods using tetrabutyl titanate, zinc acetate, lithium acetate and aniline as raw materials. The materials were characterized and analyzed by X?ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscope (SEM) transmission electron microscope （TEM） and electrochemical testing. The results show that the polyaniline in the composite material has an amorphous structure and no impurities are introduced. When the coating amount of polyaniline is 5.3%, the discharge specific capacity is 330.0 (mA·h)/g at 0.1 A/g. In addition, after 100 cycles, the specific discharge capacity is 281.3 (mA·h)/g.

Hierarchical porous Hβ molecular sieve with different structure and acidity were prepared by alkali treatment. XRD, SEM, N₂ physical adsorption and NH₃?TPD characterization methods were used to characterize molecular sieves before and after alkali treatment. With hierarchical porous Hβ molecular sieve as the carrier, the Ru?Hβ bifunctional catalysts were prepared by an equal volume impregnation method, and the benzene hydroalkylation reaction activity and stability were evaluated in a fixed bed reactor.The results show that Hβ molecular sieve can effectively increase the proportion of mesopores after being treated with a proper concentration of alkali, which is beneficial to improve the hydroalkylation activity and stability. At 2 MPa, 210 ℃ and a liquid hourly space velocity of 1 h^-1, when the Ru mass fraction is 0.2% (based on the mass of hierarchical porous Hβ molecular sieve), the dual?functional catalyst composed of hierarchical porous Hβ can achieve effective and stable operation. At the same time, the conversion rate of benzene is 54.32%, the selectivity of cyclohexyl benzene is 71.47%, and the stability of the catalyst does not decrease significantly within 280 h.

Ir(Ⅲ) complex Ir(ppy)₃ was used as luminescent probe of the detection of three nitroaromatics include 3?nitrobenzoic acid, 3?nitrobenzyl alcohol, and 3?nitrotrifluorotoluene. And the luminescent detection mechanism was studied by density functional theory calculation and spectral analysis. The results showed that 3?nitrobenzoic acid, 3?nitrobenzyl alcohol and 3?nitrotrifluorotoluene could quench the luminescence of Ir(ppy)₃ in acetonitrile, with detection efficiencies K_SV of 20.4 L/mmol, 1.8 L/mmol and 2.8 L/mmol, and the lowest detection limits are 0.155×10^-6 mol/L, 1.760×10^-6 mol/L and 1.116×10^-6 mol/L, respectively. The luminescent detection mechanism of 3?nitrobenzoic acid, 3?nitrobenzyl alcohol, and 3?nitrotrifluorotoluene of Ir(ppy)₃ is electron transfer.

A method for synthesizing β?hydroxyethyl sulfide by reacting a thiol with ethylene carbonate by an organic acid potassium salt (KA) was reported. The results show that under normal pressure and solvent?free conditions, KOAc, KSAc and HCOOK have higher catalytic activity, and the catalytic activity of multi?organic potassium salt is relatively lower, while CF₃SO₃K and CH₃SO₃K have no catalytic activity. With KOAc as a catalyst, the order of reaction of various thiols is thiophenol>2?mercaptoethanol>hydrazine thiol>normal aliphatic thiol. According to the theory of soft and hard acid and base, the activation mechanism of -S-H by potassium salt was discussed.

The C12-C16 olefin fractions were separated by distillation from coal chemical mixed olefins. The obtained C12-C16 olefins were used as raw materials to synthesize polyalphaolefin (PAO) by AlCl₃ catalyst. The influence of polymerization temperature, polymerization time, polymerization pressure and amount of catalyst were researched. The optimum polymerization conditions were determined. The physical properties of the product were analyzed. The results show that the evaporation temperature of C12-C16 olefins in cold trap oil is 214~274 ℃. Under the conditions of polymerization temperature of 137 ℃, polymerization time of 40 min, polymerization pressure of 4.0 MPa and catalyst mass of 10 g, the polymerization yield is 84.57%, and the kinematic viscosity of obtained PAO product at 40 ℃ is 32.53 mm²/s, the flash point is 221 ℃, the freezing point is -53 ℃, and the bromine value is 9.6 g(Br)/(100 g) .

In recent years, light?emitting organics have attracted widespread attention due to their unique functions. Among them, room temperature phosphorescent organics have the characteristics of longer wavelength and long life due to their triplet excitons and relatively slow decay rate, resulting in a wide range of application prospects in optical devices, photocatalytic reactions and other fields. At present, the construction of room temperature phosphorescent organic system is mainly accomplished by promoting spin?orbit coupling and suppressing the non?radiative decay process from the triplet state to the ground state. This article summarized the development of room temperature phosphorescent organic system in recent years. According to how to design room temperature phosphorescent organic system, several methods were proposed and their principles were analyzed, and the future development and application of room temperature phosphorescence organic system were prospected.

According to the characteristics of the canteen, the FLACS software was used to build a three?dimensional model for a university canteen. On the basis of considering the jet direction, obstacles and other factors, the leakage and explosion of natural gas were simulated, and the diffusion process of gas cloud, the development law of explosion shock wave and temperature in a specific scene were studied. The results show that when the gas leaks vertically upward, the gas accumulates in the small booth due to the obstruction of the canteen roof. When the natural gas leaks horizontally, the volume fraction of natural gas cloud in the dining area is higher. At the initial stage of the explosion, the explosion pressure shock wave centered on the ignition point first appears, and the pressure shock wave travels outward in a circular arc. The leakage direction has little effect on the maximum over pressure generated by the explosion.The temperature distribution is greatly affected by the direction of leakage. When vertical injection is carried out, the high temperature is concentrated in the small booth. When horizontal injection is carried out, the temperature is distributed from high to low.

At present, water injection is often used to extract oil, but CO₂ corrosion often occurs in water?bearing pipelines. Therefore, Computational Fluid Dynamics (CFD) was used to study the distribution of oil and water in straight pipes and bends at different water content (volume) and flow rates, to determine the conditions for the occurrence of CO₂ corrosion in oil pipelines, and the effect of flow rate and water content on the wall shear force was analyzed. The results show that the occurrence of CO₂ corrosion depends on the water content and flow rate in the pipeline. When the water content increases, oil infiltration in the inner wall of the pipe to prevent corrosion; when the water content decreases, the amount of water accumulation increases, resulting in serious CO₂ corrosion. When the flow rate increases, turbulence occurs in the pipeline, so it is difficult to form water accumulation, reducing the risk of corrosion. However, an increase in flow rate will lead to an increase in wall shear, which will destroy the corrosion product film and further accelerate the corrosion rate. In downward elbows, under the action of gravity, water often does not occur in the pipeline, and the risk of corrosion is low; in upward elbows, water is most likely to occur, and the risk of corrosion is high; affected by scouring, the elbow end is corroded seriously. The elbow end is susceptible to the interaction of corrosion and mechanics, so corrosion is serious. The research results have certain guiding significance for the safe operation of oilfield gathering pipelines.

Soil collapse in natural disasters seriously threatens to the stability of buried pipelines. In order to study the stability of buried pipelines in the suspended collapse area, based on the finite element method,the displacement, strain and stress of buried elbows with different wall thickness and outer diameter in the suspended state were studied. Based on the eigenvalue buckling theory, the ultimate length that the buried elbow can withstand when the soil collapses under certain conditions was studied. The results show that reducing the buried depth, increasing the outer diameter and wall thickness can effectively reduce the displacement of pipeline in soil collapse. The stress and strain of the pipeline occur in the center of the collapse area and the fixed ends of the two sides; the increase of the outer diameter and wall thickness of the pipeline can inhibit the occurrence of local excessive stress to a certain extent. The ultimate length of the buried elbow in the goaf is about 87 m, and improving the outer diameter and wall thickness of the pipeline can enhance the buckling resistance of the buried elbow in the process of soil collapse.

In order to improve the accuracy of gasifier risk assessment, a safety assessment method that combines cloud model with catastrophe progression method was proposed. Through literature review and expert analysis, the risks of the gasifier are divided into mechanical systems, personnel, management and environmental risks, and a multi?level risk assessment system for the gasifier was established. The cloud model is an effective tool for qualitative and quantitative conversion. The entropy and hyper?entropy feature values of the cloud model were introduced, and the cloud entropy weight method was proposed to improve the traditional weight calculation method, and the weight calculation of all indicators was carried out to improve the accuracy of the ranking results. According to the normalization formula, the mutation membership value of each layer index and the total mutation membership value of the gasifier are calculated, and the risk level of the gasifier is judged according to the risk level evaluation table. The research results show that this method improves the comprehensiveness and objectivity of the weight ranking, and makes the gasifier risk assessment results consistent with the actual situation, which verifies the feasibility and effectiveness of the method.

In this paper, the heat treatment process of carburizing and quenching of 20CrMnTi steel gear was simulated by DEFORM?HT software, and the carbon mass fraction change from the surface layer to the core after carburization was obtained. The changes in the martensite structure after quenching were analyzed, the residual stress after quenching was analyzed, the appropriate quenching cooling medium was selected, and the metallographic structure and the Rockwell hardness from the surface to the core were measured through experiments. The results show that the metallographic structure and Rockwell hardness are in good agreement with the simulation results, which have certain guiding significance for production.

The compliant microgrippers are directly contacted with the gripper in the microoperation field and during microassembly.And as the end microactuator in the micro?operation and micro?assembly system,it plays an important role in realizing micro?operation and micro?assembly tasks.A flexible microgripper mechanism based on straight circular flexure hinge and reed isosceles trapezoidal flexure hinge was studied in this paper.The displacement amplification and parallel displacement of gripper displacement were realized by piezoelectric ceramic driving.The mechanical pseudo?rigid body model of the flexible microgripper was established, and the kinematics model was established by using the pseudo?rigid body model method.Furthermore, the displacement amplification factor was calculated, and the relationship among the input force, input displacement and output displacement was obtained.The finite element method was used to simulate and verify the model.The results show that the prediction of theoretical values is consistent with the simulation results.

For a long time, fabric defect detection has been completed by quality inspectors. Meanwhile, the process of defect discrimination is greatly affected by subjective factors and has the problems of low detection efficiency and high cost. With the close combination of computer vision technology and various fields, fabric defect detection system based on vision has gradually become an important solution to replace manual quality inspection. For the fabric defect detection based on vision, this paper reviews the aspects including industry development, general detection standards, overall structure of the system and key technologies in detection algorithms, introduces the existing fabric defect detection products based on vision in the market, analyzes the common defect detection standards and the basic structure of the detection system, and summarizes and compares the research status of image processing and deep learning technology in the field of fabric defect detection in recent years. Finally, the paper summarizes the key problems to be solved, and discusses the possible development direction in the future.

Logging while drilling (LWD) technology can obtain more real formation data information than traditional logging, so it is more suitable for practical applications. What follows is how to quickly and accurately determine whether the mixture contains crude oil in the process of testing while drilling, that is, to achieve qualitative analysis of the mixture. Laser Raman spectroscopy analysis technology, as a relatively complete molecular spectroscopy technology currently developed, has been widely used in the field of many kinds of material analysis. In this paper, according to the characteristics of crude oil drilling fluid mixture, based on laser Raman spectrum analysis technology, a qualitative analysis algorithm based on partial least squares analysis was proposed. At the same time, the known Raman spectra are smoothed and denoised, baseline correction based on the fitting polynomial method, normalization and other pre?processing operations. On this basis, the feature extraction process with singular value decomposition as the main method was completed, thus attained the aim of qualitative analysis of mixture, and completed the quantitative calculation within a certain precision.

In view of the unstable and nonlinear characteristics of the rolling bearing vibration signal of rotating electrical machines, the traditional time?frequency analysis method and wavelet packet decomposition method have energy leakage and poor adaptive ability in the signal decomposition process, and the EMD decomposition method has modal aliasing and other problems. In order to improve the fault diagnosis accuracy of rolling bearings, CEEMDAN combined with energy moment method is proposed to extract the original vibration signal features. The weight and offset of ELM hidden layer are optimized by SPSO algorithm, and the CEEMDAN?SPSO?ELM method is used to analyze and diagnose single and multiple damage faults of rolling bearings.The effectiveness of the algorithm and the improvement of diagnosis accuracy are verified by comparative experiments.

The aero?engine clamp has an assembly constraint relationship with the pipeline, and its layout position has an important influence on the direction of the pipeline and the vibration performance. An optimization method of engine clamp position adjustment based on improved Grey Wolf Optimization (GWO) was proposed. Based on the existing pipe?clamp geometric layout scheme, this method takes the adjustment of the natural frequency of the pipe?clamp to avoid resonance as the main optimization goal, takes the pipeline obstacle avoidance and the pipeline?clamp meeting assembly constraints as constraints, and applies the improved GWO algorithm to carry out the secondary optimization and adjustment of the clamp position. In order not to affect the geometric layout of the pipeline, an optimized space for the position of the clamp based on the pipeline projection line was established. In order to improve the efficiency of optimization calculation, the Kriging surrogate model reflecting the position of clamp and the natural frequency of pipeline was established to replace the time?consuming finite element calculation program in the optimization process. In order to improve the search performance of GWO, a GWO algorithm with improved convergence factor was proposed. This method can optimize the position of the clamp under the premise of ensuring the fine adjustment of the pipe geometric layout, and can ensure that the pipe and clamp meet the assembly constraints. Finally, the effectiveness of the proposed method was verified by the test function example and the clamp arrangement example.