In order to solve the problem of poor stability of traditional electrolyte membrane in all solid state lithium battery, a preparation method of thermally crosslinkable polymer electrolyte membrane for all solid state lithium battery of electric vehicle was proposed. Using 2-mercapto benzoxazole, sodium 5-sulfonate dihydro-2-mercapto benzimidazole complex as raw materials, then using toluene and dimethylformamide as preparation reagents, using high-speed centrifuge, magnetic stirrers and other preparation instruments for the preparation of all solid state lithium battery can be thermocrosslinked polymer preparation, and using the thermocrosslinked polymer to prepare the electrolyte membrane. The performance of the electrolyte membrane prepared is verified by comparative experiments. The experimental results show that the electrolyte membrane prepared by this method has smaller ion exchange capacity and higher proton conductivity, indicating that the preparation method has better stability.
The objective is to explore the change of natural vibration characteristics and seismic performance of concrete filled steel tubular arch bridge（CFST） under ambient temperature. The study was carried out by means of mechanical analysis. Firstly, the self-vibration frequency of the super-stationary structure of the arch bridge under the influence of ambient temperature is calculated based on structural dynamics. The degree of influence of ambient temperature changes on the self-oscillation frequency of the bridge structure is also analysed. Secondly, the structural response of the arch bridge during ground shaking is analysed based on the time course analysis method and interpreted in relation to the material elastoplasticity, travelling wave effect and the interaction between the structure and the foundation. Then, the research object of the above-bearing steel pipe and concrete arch bridge is taken as the research object, and the finite element analysis software is used to simulate and test the effect of the steel pipe and concrete arch bridge under the influence of ambient temperature. The experimental results show that the temperature variation characteristics of the arch bridge materials affect the self-oscillation frequency, with the modulus of elasticity of the asphalt material being more affected by the temperature variation. The frequency changes drastically in low and high temperature environments, causing the vibration pattern of the arch bridge to change. The effect of ambient temperature on the vertical ground vibration response of the arch ribs is negligible, while the lateral and longitudinal ground vibration response of the arch ribs increases at low temperatures. The results provide a reference for the seismic design of similar CFSTs.
The magnetic permeability and power consumption of FeNiMo cores were studied at heat treatment temperatures ranging from 590 to 730 ℃ using aerosolized powder. The magnetic permeability of the cores increased from 110 to 161 with the increase of heat treatment temperature, and the power consumption decreased and then increased. The cores at 650 ℃ heat treatment temperature had the smallest power consumption of 488.2 mW/cm~3 under the test conditions of f=100 kHz and B m =100 mT. The loss separation shows that the proportion of eddy current loss to the total power loss increases with the increase of frequency f and flux density B m with the increase of heat treatment temperature, the hysteresis loss decreases continuously, and the hysteresis loss no longer changes significantly at 650 ℃; The eddy current loss rises when the heat treatment temperature reaches 730 ℃. This is caused by the destruction of the insulation layer between the particles inside the magnetic powder core due to the high heat treatment temperature.
A variety of different components of aluminum-lithium alloy powder were designed and prepared. The aluminum-lithium alloy powder is formed by Selective Laser Melting（SLM）, and the highly dense, crack-free self-developed Al-Mg-Li alloy forming parts were selected for heat treatment process research. The results show that the third generation of Al-Li-Cu alloy is very prone to micro-cracks in the process of rapid solidification of SLM, and the second generation of Al-Li-Mg alloy is more suitable for SLM, which can obtain highly dense, crack-free forming samples. SLM Al-Li-Mg alloy is aged and heat treated at 200 ℃, the reinforced phase is mainly δ′ phase, the aging period reaches the peak aging state for 48 h, and the aging time continues to be extended, and its mechanical properties have decreased.
Studying the mechanical properties and deformation mechanism of pipe jacking tunnel joint is great significance to investigate the hidden dangers of pipe jacking tunnel. ABAQUS software has professional data processing and analysis functions. ABAQUS software is used for modeling to form the bending stiffness model of socket joint of circular rigid jacking tunnel based on ABAQUS. Simulation experiments are carried out to study the factors affecting the mechanical properties of socket joints. The results show that the stress change of socket joint is less affected by the tensile speed of rubber seal ring and more affected by hardness. When studying the influence of steel casing on the bending stiffness of the joint, it is found that the bending moment increases with the increase of opening angle, the bending stiffness increases with the increase of the thickness of steel collar, and increases with the increase of the length of steel collar.
As a fascinating and widely used polymer, polyimide（PI） has become a new research hotspot and drawn broad interdisciplinary attention as a visible-light-responsive photocatalyst. This is due to its appealing electronic band structure and high physicochemical stability. A panorama of the latest progress related to the design and construction of PI and PI based composite photocatalyst were summarized, including graphitic carbon nitride（g-C 3 N 4 ） based photocatalytic structure in polyimide, nanoarchitecture design of bare polyimide and its photocatalytic ability, modification of PI and well-matched energy levels of another semiconductor to form heterojunction nanostructure. There will be also theoretically discussed the band structures, electronic properties, optical absorption, and interfacial charge transfer in PI-based heterostructures nanohybrids. It is anticipated that can stimulate a new research doorway to facilitate the next generation of PI based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties.
Hydrogen affects metal properties very sensitively. Whether from preventing the harmful effect of hydrogen or actively using hydrogen energy, it is necessary to have a deeper understanding of the interaction between hydrogen and metal. Taking the commonly used metals in industry as the main object, from the aspects of electron, atom, crystal structure and thermodynamics, the process of hydrogen entering the metal and its state in the metal, the solid solution and position of hydrogen in the metal, the factors affecting the hydrogen concentration, the diffusion behavior of hydrogen, the metal hydrogen phase diagram and the law of the influence of hydrogen on the properties of metal were summarized and introduced.
According to the individual needs of users, the optimal production control method is determined by studying the working principle of the whole plate printer and orthogonal experiment. Research showed that: the pressure of dip roll, transfer roll and the fluid flow had played a key role for high speed printing line.Through orthogonal experiment, the control measures on printing line on the surface of electrolytic tinplate are put forward.The line speed achieved 470 mpm.
Anode electrode material is an important part of sodium ion battery, which directly affects the specific capacity, magnification performance and cycle stability of the battery. Metal selenides are considered as one of the most promising cathode materials for sodium ion batteries because of their high specific capacity and high reaction kinetics. SnSe 2 @PC nanorods were prepared by selenidation carbonization-selenium strategy using coordination polymers as precursors. The effect of selenium process on the sodium ion storage performance of SnSe 2 @PC nanorods was studied. The results show that SnSe 2 @PC nanoflowers obtained by carbonization at 700 ℃ and selenidation at 400 ℃ have excellent sodium ion storage properties, and their reversible specific capacity reaches 172.6 mAh g -1 at 10 A g -1 current density.At the same time, under the current density of 5 A g -1 , the specific capacity can still reach 175.8 mAh g -1 after 900 cycles.
Microstructure of H220BD steel was observed by OM with different annealing temperature and different dew point conditions in furnace, surface morphology was observed by OM and SEM with different different dew point, its mechanical properties and aging performance with different annealing temperature and different dew point were tested. The results show that the dew point in the furnace has no effect on the surface morphology and grain size. When the dew point in the furnace is low, the degree of decarburization is low, BH value is high, and aging performance is poor. When the dew point in the furnace increases, aging performance is good, but BH value decreases accordingly. Grain size and BH value increase as annealing temperature increases, when the annealing temperature is 820 ℃, dew point in the furnace is-20 ℃, BH value and aging performance can reach the best, and aging performance can meet more than six months.
Phenolic compounds have a wide range of applications in chemical production and it’s of great importance in both chemical raw material and intermediate. During the process, the phenol-containing wastewater it produced has a wide range of sources. At the same time, because of the strong pollution and difficult degradation, it is particularly important to improve the treatment technology of phenol-containing wastewater. Adsorption is the most common, simple and efficient method in solving the problems of phenol-containing wastewater. The key of it is the reasonable selection of adsorption materials. Metal-organic frameworks（MOFs） is a kind of coordination polymer developed rapidly in recent years. It is a new kind of porous material besides zeolite and carbon nanotubes. It is useful and effective in catalysis, energy storage and separation. Reviewed the research progress of adsorption of phenol-containing wastewater by MOFs and summarized the types, structures and preparation methods of MOFs by comparing. Meanwhile made a further clarification on the adsorption mechanism and the factors affecting the adsorption process of phenol-containing wastewater. What′s more, prospected the improvement direction and application prospect of the adsorption performance of MOFs.
2 mm thick Al/Li dissimilar alloys plate under different welding conditions were chosen for numerical simulation. The model of heat source and cold source are established by finite element analysis software ABAQUS. Temperature filed and stress field of friction stir welding was compared under conditions of air cooling and intense cooling. Results show that the temperature field during welding presents an elliptical distribution, and the residual stresses perpendicular to the weld exhibits an "M" tendency. Meanwhile, the peak residual stresses are located at the edge of the shoulder zone. Compared with the air cooling condition, the peak stress on the upper surface of the AA2060 welded plate was reduced by 13%. At the same intense cooling distance, decreasing the intense cooling temperature increased the temperature gradient between the heat and cold sources, thereby leading to the decreased residual stresses. It has been shown that the residual stress in Al/Li alloys can be effectively controlled by intense cooling during welding.
Because of its light weight, low density, low thermal expansion coefficient, corrosion resistance, high strength, high stiffness, high temperature strength and thermal stability, good wear and fatigue resistance, Al matrix composites are used more and more widely in industry. Combined with the current research of aluminum matrix composites, the types and characteristics of reinforcements, preparation methods, interface problems and optimization mechanism, main application fields were summarized and discussed.
Based on the investigation of the production and sales of complete vehicles equipped with driving assistance system (ADAS) in 2020, as well as the current situation analysis and prediction of the market penetration of the main functions of ADAS, this paper puts forward that 2022-2025 will be the window period for the rapid development of auxiliary driving vehicles. Through the investigation of the development of main safety technologies of ADAS and the overview of the current situation of auxiliary driving functions, this paper analyzes the reasons for the supply interruption of vehicle specification chip supply chain and the current situation of production capacity in recent one year, and puts forward that vehicle and parts enterprises, including government departments, should rethink the industrial chain layout of automobile chips in the next five years, so as to promote the commercialization of domestic auxiliary driving vehicles (equipped with ADAS) as soon as possible.
电化学沉积是一种制备高性能与高可靠Au-30%（原子分数）Sn共晶合金封装材料的较好方法。采用恒电流法从一种无氰Au-Sn电镀液中沉积得到Au-Sn共晶合金薄膜。通过电化学测试、合金薄膜成分与形貌分析以及多批次重现性实验，确定在-2.0 mA/cm~2电流密度下可以沉积出表面平整致密且Sn原子含量稳定在30%（原子分数）左右的Au-Sn共晶合金薄膜。Au-Sn共晶合金薄膜的沉积速率约为5.0μm/h。差热分析曲线（DSC）表明，Au-Sn共晶合金薄膜共晶点温度为277.4℃,与理论值相一致。另外，该无氰Au-Sn电镀液具有较好的储存寿命。研究结果可以为无氰共沉积Au-Sn共晶合金薄膜提供一定的参考和经验。
利用水气联合雾化方法制备铜粉，考察了不同水雾化压力（20、35、68、87、99 MPa）对粉末粒度、化学成分、氧含量、形貌、安息角的影响。结果发现，在铜熔液加热到1 300℃,保温30 min,气雾化压力2 MPa,水雾化压力99 MPa的条件下，得到的铜粉球形度最高，氧含量最低、粒度分布范围最小、粉末在50μm以下的铜粉收得率达到80%以上。
为分析铝合金壳体模具高密度压铸成型方法的压铸效果,以机电设备的壳体模具为例,设计其内浇口系统、铸压机型号、初始和边界两种条件.确定压铸方案后,利用Flow-3D软件内TruVOF方法,依据方案中机电设备的壳体模具高密压铸数值,模拟铝合金熔融后液体充型过程,完成机电设备的壳体模具压铸成型,并且通过Flow-3D软件的Metal Casting Models方法跟踪铸件缺陷以及缺陷分析.分析结果显示:利用该方案压铸生产的铸件存在大范围卷气现象,铸件密度低于铝合金标准密度;根据分析结果,增加内浇口数量以及设计环形溢流槽,优化压铸方案,可有效降低压铸充型过程中发生卷气现象,使卷气发生最高值从0.578下降至0.382左右,提升铸件密度质量.
采用Ar气体保护焊的焊接方法,选择"基体+过渡层+保护层"的结构,首先在35CrMo钢上堆焊ER83-1的低合金钢焊丝的过渡层,随后在过渡层上堆焊HS112耐磨钢焊丝的保护层,焊接电流为300 A,焊接电压为25 V,焊接速度为7 mm/s,气体流量为18 L·min-1,并选择左向焊的焊接方法,以获得连接质量较好的焊接连接层.对过渡层、保护层进行了显微组织、硬度及拉伸性能的分析,结果表明,在基体和过渡层的连接层中,铁素体薄层和珠光体以长块状形态交替分布,这种弥散分布的形式有利于改善过渡层的塑韧性;而过渡层+保护层由细针状铁素体、少量块状铁素体以及珠光体组成,此时保护层的硬度在47～49HRC范围内,而抗拉强度达到了 765.8 MPa.
钕铁硼晶界扩散技术已成为制备超高矫顽力烧结钕铁硼产品的必备技术,但是重稀土扩散源提升磁体矫顽力的行为及机制有诸多问题需要研究.利用高温激光扫描共聚焦金相显微镜(LSCM)对已经进行过晶界扩散的钕铁硼磁体重新进行高温加热和冷却,结合扫描电镜、电子探针、脉冲场磁强计观察初始状态、加热过程、冷却后的磁性能、微观组织行为及特征对比,结果发现:晶界扩散磁体进行过LSCM高温加热观测再经过冷却后,矫顽力下降636 kA/m,剩磁也进一步下降0.014 T,经过热处理后矫顽力未能完全恢复;LSCM高温加热实验发现,晶界扩散磁体加热过程中,在600～700℃范围内先后出现灰色和黑色的斑点并逐步扩展覆盖整体表面;冷却后样品表面被Nd、Dy、Al、Cu为主的膜层覆盖,说明加热过程中的斑点扩展是液相熔化后溢出表面并覆盖表面形成膜层的推论性解释;LSCM实验前后元素面分布图对比表明,高温加热后即便晶界和Dy分布显得连续,但因为高温加热破坏原有结构,矫顽力较低;重稀土在晶界附近的偏聚及高温下的相变诱导了主相周围形成高各向异性的(Nd,Dy)2 Fe14 B壳层,是晶界扩散提升矫顽力的核心原因.
铝合金材料是当前汽车车身板材制作的主要材料,但在板材过厚的条件下,易形成飞边、气孔以及未焊合等缺陷,严重时将威胁汽车行驶安全,因此分析铝合金车板板材焊缝组织缺陷.在明确铝合金车身板材的焊接性能基础上,选取型号为EN-AW6005A-T6、EN-AW5083A-H111以及EN-AW6082-T6的铝合金材料作为母材,采用盘状MIG焊焊丝和棒状TIG焊焊丝和带锥形螺纹搅拌针的焊具,根据相应的工艺要点完成铝合金车身板材焊接.分析不同焊缝组织缺陷得到以下结论:孔洞缺陷形成的主要原因是焊缝中、下部材料塑性流动较差;铝合金车板板材表层过度软化是导致飞边缺陷形成的主要原因;未焊合发生在焊缝底部,其产生原因是焊接热输入不足,焊缝底部再结晶程度低;焊核区底部焊缝组织显微硬度值较低,而顶部值相对较高.
