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121.
针对汽车大型覆盖件零件的工艺特点,采用先进的模拟仿真技术、测量技术、调试技术、逆向工程技术,探索出了一条汽车大型覆盖件模具制造调试的途径。 相似文献
122.
我国型钢生产技术进步20年及展望 总被引:3,自引:1,他引:3
按小型材、棒线材、中型材、轨梁和大型材分类 ,对 2 0年来我国在型钢生产领域的主要技术进步进行了总结 ,对其生产现状进行了分析 ,对其发展前景进行了展望 相似文献
123.
Effects of Austempering after Hot Deformation on the Mechanical Properties of Hot Rolled Si-Mn TRIP Steel Sheets 总被引:1,自引:0,他引:1
LIZhuang ZHANGPing-li WUDi 《材料热处理学报》2004,25(5):248-251
Excellent mechanical properties are obtained by austempering after hot deformation without subsequent heat treatment in the present Si-Mn TRIP steel sheets. Isothermal holding time after finishing rolling has affected the mechanical properties of this steel. The results show that the sample exhibits a good combination of ultimate tensile strength and total elongation when it is held at the bainite transformation temperature after hot deformation. The stability of retained austenite increases with an increase of isothermal holding time, and a further increase in the holding duration results in a decrease of it. The tensile strength, total elongation and strength ductility reach the maximum values (774MPa, 33% and 25542MPa% respectively) for this sort of hot rolled Si-Mn TRIP steel using the optimal technology. 相似文献
124.
Gaussian type models have been established according to the real detected voltage of magnetically insulated ion diode and intense pulsed ion beam density near the focus of the diode. The energy deposition of Al target irradiated by intense pulsed ion beam has been simulated by Monte Carlo method based on these models. The results of energy depositions of the irradiation of single energy ions and the Gaussian distribution IPIB have been obtained. Especially cases of ion beam irradiating Al target at different angles on one dimension and two dimensions are discussed. The evolution processes of the energy deposition of ions in target have been simulated during a pulse. In addition, incident angles of H+ ions and C+ ions ranging from 20 to 40° have been researched. We obtained the conclusions that C+ ions of the beam affect the physical properties of near surface region, but H+ ions affect the deeper layer. The energy of intense pulsed ion beam mainly deposits on target surface, so melting and evaporation begin both from target surface. 相似文献
125.
126.
127.
小径管焊缝射线照相标准的实践与问题研讨 总被引:5,自引:1,他引:5
通过分析小径管焊缝射线检验中存在问题,对X射线检测标准作了进一步探讨。 相似文献
128.
A. Domingue K. Piyakis E. Sacher M. Di Renzo S. D nomm e T. H. Ellis 《The Journal of Adhesion》1993,40(2):151-162
The irreversibly bound interfacial layer deposited by the γ-aminopropysilanetriol adhesion promoter onto a crystalline silicon substrate, which remains even after profuse washing, was found by XPS to have resulted from the fragmentation and rearrangement of the original γ-aminopropylsilanetriol molecule. A mechanism is proposed, involving the homolytic scission of the terminal N-C bond. One of the subsequent reactions is believed to involve hydrogen loss by abstraction and the formation of a terminal vinyl group, which bonds to the substrate. Support for this mechanism is found in IR spectroscopy of this layer. 相似文献
129.
通过理论推导证明:在外扩散与化学抑制共存的非均相固定化酶促反应中,总有效系数η为外扩散有效系数ηdif和化学抑制有效系数ηch的乘积,并且分别小于相应的ηdif和ηch;从数学上解释了外扩散抑制和一般性化学抑制间所存在的“抗激发互交作用”。利用所得公式计算表明:底物浓度对外扩散与竞争性、非竞争性和反竞争性等不同化学抑制共存的非均相固定化酶促反应有明显不同的影响;扩散抑制均显著地影响非均相固定化酶促反应,使得反应体系的总有效系数随抑制作用的增加而明显减小,从而对这类反应有了更进一步的认识 相似文献
130.
Huyong Yan Guoyin Wang Di Wu Yu Huang Mingsheng Shang Jianjun Xu Kun Shan Xiaoyu Shi Jianhua Dong Lei Feng Botian Zhou Ye Yuan Yufei Zhao 《Water Resources Management》2017,31(5):1435-1456
In the field of water quality management, it is vital to determine the main precursory anomalies from the precursor of intricate water bloom in the context of a given area. In this paper, a water bloom precursor analysis method, based on two direction singular rough set, was proposed. This approach was produced on the basis of the different sections and pre-water bloom of water bloom precursor anomalies and characteristic of elements transferred in singular rough set. For testing the validity of two direction singular rough set application in water bloom precursor analysis, Xiangxi River, which is one of the typical tributaries of Three Gorges Reservoir in China, was selected as study area. The result showed that compared with other indexes, pH and dissolved oxygen (DO) are the most valuable indicators of water bloom in the precursory anomalies. Furthermore, regarding with water bloom precursory anomalies in Xiangxi River, most of the nutrient loading and biological community are the key indicators. Hence, this method can determine the main precursory anomaly for water bloom in the study area, which provides powerful knowledge support to water quality specialists for them to comprehensively analyze precursory anomaly so as to find out its relationship with occurrence law of water bloom. 相似文献