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Because of poor model generalization ability and low diagnostic accuracy caused by rolling bearing fault diagnosis in a small sample environment, a novel method based on the Gram angle division field (GADF), the continuous wavelet transform (CWT) and the parallel two-dimensional group normalizatio convolutional neural network (P2D-GCNN) for the fault diagnosis of rolling bearings is proposed. Firstly, collected data are preprocessed and one-dimensional vibration signals are converted into two-dimensional images by using the Gram angle division field and the continuous wavelet transform as the input of the model. Then the data enhancement technique is used to expand the sample sub-graph to meet the input requirements of the network. The sample sub-graph is imported into the convolutional neural network with the group normalization algorithm for diagnostic detection. The results show that the generalization ability of the data processing method and the model built in this paper in the small-sample environment is much higher than that of other network models such as the small vector machine and the 1D-CNN. In order to further verify the recognition ability of the model in the small sample environment, the sample sizes of 70%, 40% and 20% of the dataset are used to do experiments many times. Their corresponding training accuracy and test accuracy were 99.38%, 99.02%, 99.47%, 98.29%, 99.05% and 97.08% respectively, indicating that the model is highly accurate for the fault diagnosis of rolling bearings in the small sample environment.

In recent years, an increasing number of English teachers have recognized the importance of reading and writing skills. Traditional English teaching methods often overlook the essential link between these skills, which hinders the improvement of students’ overall English proficiency. This paper introduces an adaptive Huber growth curve model to represent cognitive abilities in English reading. It develops an English reading ability detection model using a function-based approach. The model involves word feature extraction, fine-grained learning, and establishing information channels. These processes collectively contribute to a sequence annotation model that not only identifies but also automatically corrects errors in English writing samples. This facilitates integrated intelligent teaching of reading and writing skills. Analysis of English reading and writing capabilities among students at various colleges and universities reveals that the most notable improvement is in students’ critical thinking abilities during English reading, with most scores ranging between 3.5 and 4 and a total of 52 students participating. The difference in writing scores of the subject classes was 1.4186, of which the T value was 3.7855, the DF value was 112.3, and the P value was 0.000, which was significant, and the magnitude of the English writing scores of the subject class A was greater than that of the class B, which indicated that the integration of literacy and writing effectively improved the overall writing skills of the students.

In this study, the effects of Mg addition on the organization refinement and mechanical properties of the alloys were investigated by designing Zn-Mg binary alloys with different compositions. Solution treatment and cold drawing successfully prepared fine wire materials with smooth surface and uniform organization. The material’s mechanical properties were further improved by treating the fine wires with an optimized annealing process. Electrochemical tests and in vitro degradation experiments showed that the degradation properties of the alloy in simulated body fluids were closely related to the alloy composition and microstructure. Cytotoxicity tests showed that the prepared Zn-Mg alloys were significantly cytotoxic to tumor cells. The corrosion weight loss analysis revealed the corrosion behavior of the alloy and its trend with time. Overall, this study provides critical experimental data and theoretical basis for preparing biodegradable biomedical metal-zinc alloys with excellent performance, and lays a solid foundation for future clinical applications.

Glycerylphosphorylcholine (GPC) was prepared by transesterification using supported sodium methoxide as catalyst and natural lecithin as raw material. Sodium methoxide has been proved to be an effective catalyst for the preparation of GPC, which is easy to recover and reuse. After six repeated uses, its stability is satisfactory. The effects of agitation speed, catalyst dosage, and reaction temperature on the reaction were investigated, respectively, and the optimum conditions for preparing GPC catalyzed by supported sodium methoxide were found: the concentration of phosphorylcholine was 0.1 mol·L−1, the stirring speed was 600 rpm, the amount of catalyst was 7.5 g·L−1, the reaction temperature was 45°C, and the reaction time was 4 h; then, the conversion rate of phosphatidylcholine could reach 99%. At the same time, the reaction kinetic model was established based on the mechanism of the transesterification, and the experimental data were compared with the calculated values; it was found that the experimental data fitted the model well. Finally, the reaction activation energy obtained by the Arrhenius equation is 41.6 kJ·mol−1, which indicates that the supported sodium methoxide has good catalytic performance in this reaction system.

The rolling-heat treatment process can significantly improve the strength of D6A steel. In order to explore the toughening mechanisms of D6A alloy steel, the micrometer grade D6A alloy steel is obtained by hot rolling and intercritical warm rolling plus annealing process, which consists of ferrite matrix and granular cementite. The microstructure and mechanical properties of the experimental steel were characterized by tensile test at room temperature, SEM, X-ray diffraction and EBSD. The results show that the grain size is refined from 4.5 μm to 1.5 μm with the increase of rolling pass, the cementite content increases gradually, and the proportion of grain boundary with small angle increases. The yield strength and tensile strength increase continuously, while the elongation decreases slightly, indicating that the size of subgrain decreases continuously during the rolling process, grain boundary area, and the resistance to dislocation slip increase. At the same time, the dislocation density of the experimental steel with different rolling pass was calculated. When the thickness reduction is 88%, the dislocation density is the highest, and then the degree of working hardening is the highest. The analysis shows that with the increase of the deformation, the strength increment caused by the strengthening of the second phase and grain refinement shows an increasing trend, while the strength increment caused by dislocation enhancement first increases and then decreases. The main strengthening methods of D6A steel are second phase strengthening, fine grain strengthening and dislocation strengthening.

Taking a small watershed in the Pengzhou mountainous area of Sichuan as the research object,this paper employs historical precipitation data,watershed zoning data,DEM,and other data to calibrate the model parameters on a watershed runoff confluence model based on Navier-Stokes equation (N-S equation) with stable flow fields.The conclusions are as follows:① After model parameter calibration,the diffusion coefficient is 0.12,with an acceleration coefficient of 0.12 and a maximum water velocity of 3;② The analysis of confluence characteristics under different precipitation scenarios shows that with the increasing rainfall,the maximum water depth rises,and the time for maximum increase in water depth and the time for the maximum water depth decrease.The watersheds with the maximum time for a water depth of less than 200 min are mainly the upper watersheds,while those with the maximum time for a water depth of more than 200 min are mainly the main watersheds;③ The assessment reveals that there are no watersheds with high risk levels of mountain floods in the small watershed of Pengzhou mountainous area,17 watersheds with high levels,19 watersheds with relatively high levels,and only one watershed with low levels.

The raw materials of geopolymer come from industrial wastes, which have the advantages of lower carbon emissions and less energy consumption compared with traditional cement products. However, it still has the disadvantages of low strength, easy cracking, and low production efficiency, which limit its engineering application and development. At present, with the application and development of nanotechnology in the field of materials, it is found that nanomaterials have a good filling effect on composites, which greatly improves the integrity of the composites. It has become a very popular research direction to optimize and improve the engineering application performance of geopolymer concrete (GPC) by nanomaterials. The modification of nanomaterials can further improve the properties of GPC and expand its application fields in engineering and life. Based on people’s strong interest in nanomaterial-modified GPC and providing the latest and complete research status for further related work, this paper summarized the key technical problems in the field of nanomaterials-modified GPC in the past decade. Those include the modification mechanism, dispersion mode, and mechanical properties of nanomaterials. At the same time, the application bottlenecks and key problems of nanomaterials-modified GPC are comprehensively analyzed. Finally, the prospects and challenges of future work in this field are discussed.

Objective To investigate the relation between TMB and the efficiency of PD-1/PD-L1 inhibitors treatment for non-small-cell lung cancer. Methods Studies were searched from PubMed, Embase, Cochrane Library database, Chinese Biomedical Literature Database and Wanfang Database up to March 25, 2020. RevMan 5.3 software and STATA15.0 were used for analysis. Results Twelve literatures were involved, including 1209 patients. TMB significantly improved PFS (HR=0.54, 95%CI: 0.42-0.70, P < 0.001) but reduced the ORR (OR=4.41, 95%CI: 2.54-7.63, P < 0.001) of NSCLC patients treated with PD-1/PD-L1 inhibitors. The subgroup analyses showed that the predictive value of TMB was significant in non-small cell lung cancer treated by PD-1/PD-L1 inhibitors combined with anti-CTLA-4 therapy or chemotherapy. No significant publication bias was observed by the Begg's test and Egger's test. Conclusion High tumor mutation burden may predict the improved PFS of non-small cell lung cancer by PD-1/PD-L1 inhibitors treatment, but its predictive value for OS, ORR and long-term survival need more exploration.

The adsorption of l-α-glycerophosphocholine (GPC) by cation-exchange resin 001 × 7 was studied in a batch system. The adsorbent dosage, shaking speed, and adsorption temperature were investigated. An adsorption efficiency of more than 99.4% was obtained under optimal conditions. The kinetic data evaluated by the pseudo-second-order kinetic model fitted the experimental data better than those evaluated by the pseudo-first-order model. The rate constant k2 increased when the temperature increased, indicating the adsorption was endothermic in nature. The Langmuir and Freundlich isotherm models were used to analyze the adsorption equilibrium data, and it was found that the experimental data well fitted the Langmuir isotherm model. The thermodynamic parameters, enthalpy change (ΔG0), free energy change (ΔH0), and entropy change (ΔS0), were calculated. The value of ΔG0 was found to be in the range of −5.09 to −14.20 kJ mol−1, indicating that the adsorption was spontaneous and basically physisorption, and the positive values of ΔH0 and ΔS0 exhibited that the adsorption was endothermic and the randomness of the system increased during the adsorption.

The bonding property between fibers and concrete matrixes has an important effect on the mechanical properties of composites. So far,scholars at home and abroad have done a lot of research to improve the bonding strength between the fiber and the matrix in concrete and ultimately to enhance the fiber reinforcement effect.This paper summarizes tests at home and abroad on the interfacial bonding property of fiber reinforced concrete and their evaluation indexes and analyzes the mechanism and the influence of the interfacial bonding property of modified fiber reinforced concrete from the two aspects of matrix property and fiber surface characteristics.It is concluded that nanomaterials,organic polymers,and part of the active minerals all affect the hydration process of cement concrete. The hydration evolution process,microstructure,and modification mechanism of the matrix in concrete under multi-mineral and polymer hybrid modification need to be studied immediately.Optimal modification methods for different fibers should be proposed according to economical efficiency,construction technology,and modification effect.

In order to implement the educational policy in the new era, the paper proposes to reconstruct the teaching content system of basic computer courses. It aims to form an employment ability tree that can benchmark the actual job demands with the guidance of the precise connection between the supply side of talent training and the future demand side of enterprises. Starting from the preset training needs of technical talents on autonomous controllable platforms in China, and faced with the practical problems by the teaching of basic computer courses, the teaching content is reconstructed by the three-step method of “update - feedback - continuous learning”. In the process of concrete implementation, the knowledge map of “point, line and plane” is established and the PDCA cycle model of “plan-do-check-action” is adopted to implement teaching; Bring together, build and share high-quality curriculum resources to improve teaching quality. Highquality course resources are gathered, built and shared to improve the teaching quality.

The bolted rotor is a typical rotor structure with light weight, high strength, good rigidity, flexible selection of all kinds of wheel materials, etc., which is formed by pressing and combining several sections of rotors or discs and is widely used in aero-engines and gas turbines. Aiming at blind assembly, trail assembly and inconsistent assembly tightness of bolted rotor, and the degradation and loosening of bolt tightness in service, a quantitative detection method of bolt assembly quality based on GHM multiwavelet was proposed. Using the GHM multiwavelet with excellent characteristics such as symmetry, compactness, orthogonality, vanishing moment and high order vanishing moment, feature extraction of the bolted rotor assembly tightness states was performed. The quantitative detection index of assembly quality was defined by the relative energy band distribution based on multiwavelet. The experimental verification shows that the proposed method can accurately identify six kinds of bolt states from tightness to looseness.

Catalytic efficiency in synthesis of vitamin E succinate was dramatically increased via the preparation of robust catalyst and the improvement of reaction system. 4-dimethylaminopyridine (DMAP) was covalently immobilized on nano-SiO2 to avoid the catalyst contamination of the product and permit the easy recycling of DMAP. Then, a hexane-acetone mixed solvent system was firstly introduced to replace the traditional single-solvent system, which was employed to improve the activity of immobilized DMAP derivative and the substrate solubility of the reaction system. The highest vitamin E succinate yield of 94% was achieved. In addition, the recyclability and stability of the immobilized DMAP derivative was excellent, the yield of vitamin E succinate had no obvious loss and remained 90% after recycling 20 times. The excellent results make this technology be a promising candidate for the industrial production of vitamin E succinate.

Calcined sodium silicate could serve as an efficient and benign heterogeneous catalyst for the production of L-α-glycerophosphocholine from natural lecithin. The catalytic transesterification of natural lecithin by calcined sodium silicate proceeded to almost 100% conversion under the following conditions: sodium silicate amount of 6 wt%, reaction temperature of 65°C, lecithin concentration of 10.5 mmol/l, stirring intensity of 300 rpm, reaction time of 120 min. In addition, this catalyst could be separated completely by simple centrifugation and retained high activity after three re-uses. Compared to the previously reported catalysts, calcined sodium silicate, with the significantly important characteristics of non-toxicity and easy excretion from the human body, was beneficial to the benign production of L-α-glycerophosphocholine and its security as well as application in food and medicine fields.

The moving mechanism configuration has a major impact on the static stability,dynamic stability and driving force of the wheeled service robot. Taking the six-wheel mobile underpan as the object,the relationships between the wheel layout and the static stability,dynamic stability,driving force to cross obstacle and turn are analyzed. A multi-objective optimization model for wheel layout is established and the optimal solution is derived by using MATLAB genetic algorithm toolbox. Assuming the factors of pitch angle,roll angle and drive torque as evaluation indicators,motion simulation of the mobile underpan is carried out by the virtual prototyping technology. The results show that the pitch angle and roll angle after optimization are decreased by17. 6% and 27. 2%,respectively. The average value and mean square of drive torque are decreased by 2. 8%and 3. 6%,respectively. It is beneficial to the transmission performance and endurance of the mobile underpan. The results also verify the correctness and validity of the established multi-objective optimization model.

Aiming at the problems of traditional GM (1,1) model in forecasting non-growth sequences in terms of water consumption,such as poor precision and over-fitting,a residual grey prediction model corrected with Markov chains is used to predict domestic water consumption.Based on the traditional grey prediction model,this paper firstly establishes an improved residual grey prediction model as follows:establish grey model on the absolute residual,and judge the sign of the predictive residual when t＞n based on Markov state transition matrix to correct the predictive value from grey model,and then apply the model to the prediction of domestic water consumption in Henan Province from 2007 to 2018.The results show that the average relative error of the traditional grey prediction model is 4.14%,while that of the improved residual grey prediction model is only 2.04%.The precision class of improved residual grey prediction model is “good”,meanwhile,the posterior variance of improved model is also smaller than that of the traditional model,which indicating that the improved model has higher precision and better reliability than the traditional grey prediction model,therefore,it is a new method for water consumption prediction.