Reform and optimization measures have been proposed for the talent cultivation model of mechanical engineering graduate students. The teaching curriculum system for graduate students should introduce new technologies, methods, processes, and achievements in a timely manner. With practical and innovative ability assessment as the main line, emphasis is placed on assessing students' comprehensive abilities to identify, analyze, and solve problems. It is encouraged to integrate collective guidance from a team of supervisors on the basis of the supervisor responsibility system. Scientific research training and practice are necessary means and effective ways to improve graduate education. Establishing a feedback and continuous improvement mechanism for graduate student cultivation quality is an important method to enhance the quality of cultivation. By optimizing the postgraduate talent cultivation model, the Mechanical Engineering discipline at Hunan Institute of Technology has achieved remarkable results in fostering top-notch innovative talents, providing valuable insights and references for other universities in their postgraduate mechanical engineering training programs.

Nickel-iron (NiFe)-based hydroxides are promising catalysts for water electrolysis, but suffer from poor conductivity and active site agglomeration. This study reports a FeNiO(OH)@carbon nanotube (CNT) composite catalyst fabricated by anchoring Ni2O2(OH) on CNTs followed by FeNiOx(OH)y electrodeposition. Through this design, a hierarchical conductive network and a porous structure are synergistically constructed, which simultaneously addresses the bottlenecks of poor conductivity and active site agglomeration in NiFe hydroxides while significantly enhancing mass transport efficiency. The CNT network not only significantly enhances conductivity but also forms a hierarchical porous structure, improving mass transport. The optimized catalyst exhibits excellent bifunctional activity, requiring low overpotentials of 169 mV for the HER and 193 mV for the OER at 10 mA cm-2 in 1.0 M KOH, with small Tafel slopes of 68 and 32 mV dec-1, respectively. It also demonstrates outstanding stability over 100 h (hydrogen evolution reaction (HER)) and 150 h (oxygen evolution reaction). The assembled FeNiO(OH)@CNTs parallel to FeNiO(OH)@CNT electrolyzer achieves 10 mA cm-2 at 1.61 V, maintaining stability for 100 h. Combined characterization and mechanistic analysis results suggest that CNTs may not only improve conductivity but also facilitate the formation of the high-valence Ni3+ active phase (NiOOH) by optimizing electron transport pathways, thereby significantly reducing the HER/OER energy barriers. This finding offers a new approach for active phase engineering. This study provides an effective strategy for designing high-performance non-precious metal bifunctional electrocatalysts.

Carbon fiber reinforced phenolic resin aerogel (Cf/PRA) composites exhibit potential for ultra-high temperature thermal protection systems. Nevertheless, their application in oxidative environments is constrained by inadequate antioxidant properties and challenges in fabricating dense, crack-free coatings without substrate damage. In this study, we fabricated dense ZrB2-ZrO2-MgHPO4 coatings on Cf/PRA via liquid-solid reactions facilitated by magnesium phosphate materials. The composite coating, 1 mm in thickness, demonstrated a defect-free structure, attributed to the mutual filling of micro ZrB2 particles and nano ZrO2 particles. Consequently, the coating exhibited a high interfacial bonding strength of 5.17 MPa, owing to the difficulty of crack initiation and propagation, as well as limited strain localization. The coated Cf/PRA demonstrated robust ablation resistance, with a linear ablation rate of 0.098 mu m/s at 2500 degrees C for 120 s, a substantial temperature drop of 1980 degrees C within an 11 mm thickness, and notable thermal insulation performance. This research introduces a novel approach to enhance the ablation resistance of nano-porous carbon monolithic materials. The developed aerogel composites hold significant promise for aerospace ultra-high temperature thermal protection applications.

To enhance the ablation and anti-particle resistance of carbon matrices, a novel ZrB2-ZrO2 modified magnesium phosphate cement composite coating (ZMPCC) with room temperature curing capability was prepared using a slurry method. This novel composite coating integrates the ablation resistance of ultra-high temperature ceramics with the room temperature curing capability of phosphates. This study focused on the microstructure, mechanical properties, and ablation resistance of the coating. The results reveal that the primary bonding phase of the cured ZMPCC is magnesium phosphate, which exhibits a strong interface adhesion strength of 4.6 MPa due to the mechanical coupling at the bonding interface. When exposed to an oxyacetylene flame at temperatures up to 2400 +/- 50 degrees C for 120 s, the coating demonstrated a mass ablation rate and linear ablation rate of-5.36 x 10-3g/s and 0.102 x 10-3 mm/s, respectively. During the initial stage of ablation, the glass phase formed by ZrB2 and phosphate effectively contributed to self-healing, while in the later stage, the dense oxide layers of ZrO2 and Zr0.904Mg0.096O1.904 formed to resist further gas flow erosion.

The magnetic field (MF) environment has significant regulatory effects on the working performance of proton exchange membrane fuel cell (PEMFC). In this study, a two-phase steady-state model of coupled MF and PEMFC is developed. Using multiphysics coupling simulation and experimental verification to analyze the effects of different magnet arrangements (bipolar, anode, and cathode) on the heat and mass transfer, component transport, and electrochemical reaction of PEMFC. It is shown that the cathode magnet arrangement has optimum effects on the working performance of PEMFC, followed by the anode and bipolar arrangement. With the cathode magnet arrangement, the pressure distribution of the flow field is optimized, and the average mass fluxes of hydrogen and oxygen are respectively increased by 0.3105 g/(m2 center dot s) and 0.2517 g/ (m2 center dot s). The average mole fraction of liquid water on cathode side is reduced from 0.170 to 0.116. Meanwhile, the MF promotes gas motion, which significantly increases the oxygen molar fraction close to the outlet of flow channels. The maximum oxygen molar fraction is raised from 0.156 to 0.171, an enhancement of 9.6 %. There is a more uniform current density and temperature distribution on the PEM, with the average current density improved by 1.33 x 103 A/m2 and the maximum temperature difference reduced from 3.8 K to 1.4 K. Furthermore, the maximum power density is sequentially enhanced by 16.5 %, 26.4 % and 30.5 % for the three magnet arrangements under simulation conditions. The maximum deviation between simulation and experiment is less than 3.5 %, verifying the accuracy of results.

Stable pressure control can improve the efficiency and lifespan of proton exchange membrane fuel cell (PEMFC) systems. The anode inlet pressure of the hydrogen supply system in PEMFC is easily affected by changes in current load and purge disturbances. In response to these issues, a second-order nonlinear active disturbance rejection control (NLADRC) method applicable to the system is proposed. Firstly, a dynamic model of the hydrogen supply system based on an 80 kW PEMFC is established, and the accuracy of the model is verified. Subsequently, a NLADRC for the hydrogen supply system is designed and compared with the traditional proportional integral derivative (PID) control. Finally, the effect of NLADRC on the fuel-control union (FCU) is verified through hardware-in-the-loop (HIL) test. The simulation results show that, compared with PID control, the anode inlet pressure of the hydrogen supply system based on the NLDARC has less overshoot, a faster response speed, stronger anti-interference ability and a good following effect. Through the HIL test, it is verified that the NLADRC algorithm is also applicable to the FCU. The model and control method proposed in this paper can be used to optimize the control of the hydrogen supply system and improve the dynamic performance of PEMFC.

Proton exchange membrane fuel cell (PEMFC) is considered as a type of clean and efficient energy device. Fuel cell air supply system is a key component to maintaining the system output efficiency. In this paper, a dynamic control model for PEMFC system oxygen excess ratio (OER) management is built, and an OER control strategy is designed based on Fractional-Order PID. An OER control index mapping the relationship between the OER and the optimal net power under different load currents is proposed to improve the output performance of the system. The results show that Fractional-Order PID can achieve high accuracy and fast response real-time OER regulation under the step current in comparison to the traditional PID and Fuzzy PID control. Furthermore, under the dynamic load current of vehicle, the average relative error of OER is 2.81% under optimal OER control based on Fractional-Order PID and the power generation efficiency of the PEMFC system can be increased to 52.55%.

During the operation of the proton exchange membrane fuel cell (PEMFC), the chemical reaction yields a large amount of heat. Long-term operation may cause local overheating problems which damage the proton exchange membrane structure, pull down the fuel cell performance drastically. Aiming at improving the temperature distribution and cooling capacity of PEMFC, a novel tree-shaped fractal fuel cell bipolar plate cooling flow field is proposed. The polarization curve, current density distribution, maximum temperature, temperature uniformity, cooling hydraulic pressure drop and the water content of proton exchange membrane are investigated for the fractal cooling flow field with different number of dimensions. The results show that the tree-shaped fractal cooling flow field can achieve better distributions of coolant and temperature uniformity than parallel cooling flow field. The maximum temperature reduces from 340.7 K to 337.8 K, and temperature uniformity index reduces from 1.47 to 0.45, respectively. Compared with the serpentine cooling flow field, the tree-shaped fractal cooling flow field effectively solves the problem of excessive cooling pressure drop and reduces the parasitic power loss while ensuring efficient cooling performance. This novel cooling flow field design offers an excellent solution to solve the local overheating of PEMFC.

Low cycle fatigue tests were carried for 316L stainless steel and the material cyclic property was simulated by finite element method.The test results show that the significant cyclic additional hardening can be observed in different strain ranges and it is more evident with increase in strain range.The mixing model combined with the nonlinear kinematic hardening and the isotropic hardening is used to describe the elastic and plastic behavior.The simulation results of stress-strain agree well with the test results for the second cycle in different strain ranges.The error of the maximum stress for first 20 cycles between the simulation results and test results depends on the strain range and the maximum error is 3.20％.The energy approach is used to predict the fatigue life based on the test results and simulation results and the prediction results are in a factor-2 scatter band.

文章针对考研学生提出了“人性化关怀+细致化专业辅导”的管理模式，鼓励和引导学生考研，促成毕业生高端成才，是高校人才培养工作的一项重要内容。文章以湖南理工学院机械学院为例，从考研氛围、过程指导、心理辅导和激励机制等四个方面对该管理模式进行了剖析，为进一步做好考研学生管理工作提供了经验和借鉴。

A series of low cycle fatigue tests under stress control were conducted for the smooth and notched specimen of 022Cr17Ni12Mo2 stainless steel. The ratio of fatigue strength of smooth specimen to notched specimen decreases with decrease in fatigue life. The notched effect is more significant at lower stress level. The cyclic additional hardening is observed for the smooth and notched specimen at all test conditions. The cyclic hardening amount is larger for notched specimen than those for smooth specimen at the same stress levels.

对减速器输出轴进行动力学分析，根据受力方程、边界条件建立减速器输出轴动力学模型，采用有限元单元法进行求解，得出输出轴最危险点的位置为轴身与轴颈的交界处，此区域应力最大；另外，输出轴的轴端变形最大，因此同样是危险区域之一。以有限元分析软件ANSYS为基础，论述了输出轴的初步设计，校核其强度、刚度。

A feasible scheme of pressure vessel design was stated and an optimization design method was proposed to reduce the wall thickness. The structure design of pressure vessel was discussed based on the knowledge of material mechanics and the size parameters were calculated. ANSYS software was used to simulate according to the actual working conditions. The optimization design was conducted based on these results using the Design Opt in ANSYS. The difference was compared between traditional design method and the design method of ANSYS. The goal of improving equipment stiffness and lightweight structure was achieved by ANSYS when the technical indicator in practice could be satisfied.

文章分析了工程应用型本科院校机械类专业人才培养产教融合的背景与现状、以湖南理工学院机械学院为例,从培养方案及课程体系、实践教学体系、"双师型"教学团队、产教融合共赢途径等四个方面对其机制进行了研究与实践.对用人单位、毕业生进行调查结果显示,改革效果良好.

This paper analyzes specialized AutoCAD teaching present situation of t independent college machinery majors. It is necessary for AutoCAD teaching to put forward concrete teaching plan and goal, choose suitable teaching materials, reform teaching methods and means, and strengthen the construction of teaching staff based on the micro-lectures.The reform effect is good.

This paper analyzes specialized AutoCAD teaching present situation of machinery majors. It is necessary for AutoCAD teaching to put forward case study method. It is discussed on suitable teaching materials,teaching Organization and evaluation,teaching methods and means based on case study. The reform effect is good.

A series of low cycle fatigue tests under stress control were conducted for notched specimen of 022Cr17Ni12Mo2 stainless steel. The tensile test results show that the yield strength and tensile strength of the notched specimen are more than those of smooth specimen. The necking phenomena indicate that the material has excellent plasticity. The fatigue lives of notched specimens were predicted by the local stress-strain approach. The predictions of fatigue notched factor form tests are more accurate than those of Peterson approach. The predictions of crack initiation life are in a factor-2 scatter band.

针对Mod.9Cr-1Mo钢不同缺口半径下的多轴疲劳试验结果进行模拟计算，采用体积法进行疲劳寿命预测，并与等效应变法的预测结果进行了对比。模拟结果表明，各路径下缺口根部应力集中程度随缺口半径减小而更为明显，最大应力集中程度达3.45。等效应变法给出的疲劳寿命预测结果随着缺口半径的减小而偏于保守，保守量高达90倍。为克服等效应变法给出的偏于保守的结果，基于剪应力随距缺口根部距离的变化趋势进行有效距离的计算，采用体积法进行寿命预测，94.1%的预测结果位于2倍分散带内。

This paper analyzes specialized English teaching present situation of the new undergraduate colleges,the characteristics and course target of the course.It is necessary for specialized English teaching to put forward concrete teaching plan and goal,choose suitable teaching materials,reform teaching methods and means,and strengthen the construction of teaching staff.Based on undergraduates and Employer,the reform effect is good.