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71.
用密度泛函理论(B3LYP)方法和相对论有效原子实势(RECP)近似,研究了NiVTi、TiV2、NiV2、NiTi2和TiNi2的平衡结构与性质,讨论了最高占据轨道(HOMO)与最低空轨道(LUMO)之间的能级间隙,分析了聚合物体系的稳定性质。 相似文献
72.
LI Liang SONG Jian HE Lin ZHANG Mengjun LI Hongzhi State Key Laboratory of Automotive Safety Energy Tsinghua University Beijing China 《机械工程学报(英文版)》2011,(3)
The early fatigue damage in the van-body of the semi-trailer is often caused by the unique mechanical characteristics and the dynamic impact of the loads.The traditional finite element method with static strength analysis cannot support the fatigue design of van-body;thus,the dynamics analysis should be adopted for the endurance performance.The accurate dynamics model to describe the transient impacts of all kinds of uneven road and the proper system transfer functions to calculate the load transfer effects... 相似文献
73.
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75.
对中型中密度纤维板生产中造成环境污染的污染源、污染因子进行了分析研究,根据同类企业实际运行情况提出了治理途径和解决措施。 相似文献
76.
由国家计量部门相关政策变更所引发的一系列问题,给射线检测结果带来诸多变数,也直接影响到检测的质量。启用兰片基标准密度片奖有助于广大密度计用户及时发现问起,并找到解决问题的好方法。 相似文献
77.
A new model for describing the compaction process of iron powder was proposed based on the continuum hypothesis and elliptical yield criterion. To simulate the densification behaviour, the constitutive model was implemented in Marc computer program. For the relationship between load and displacement, different models were compared and the influence of the parameters in the constitutive equations was determined by means of simulation and experiments. The density distribution of a balancer was measured and simulated. The results show that the parameter η adopted plays a modification role for the load-displacement curve, and compared with other models the present model fits better with the experimental data in the later stage of the compaction process mainly due to the different parameters A and B. The friction on the contact surface contributes to the inhomogeneous density distribution under large deformation of the workpiece. The comparison between the simulation and experimental data indicates that this model can be used to predict the powder compact process precisely and effectively. 相似文献
78.
Simultaneous measurements of space charge and external current were carried out using a PEA measurement system with an electrometer on the back of a grounding electrode in order to clarify the physical situation of a huge packet of positive space charges in LDPE films. A large number of positive charges from a semiconducting anode were accumulated at the interface between LDPE and an Al‐cathode at a mean applied field of 1.5 MV/cm and then finally disappeared. The results of simultaneous measurements showed that the external current kept a relatively high value during charge accumulation and further increased when the charges disappeared. Both the charge dynamics and the external current were restricted by addition of a low‐molecular‐weight paraffin wax, indicating that carrier transport was influenced by the microstructure of the polymer. The dynamics of the residual charges after short‐circuiting is also discussed. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(4): 10–17, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21256 相似文献
79.
WANG Wei-xing 《中国电子科技》2005,3(4):310-313
Given image sequences of closely packed particles, the underlying aim is to estimate diameters without explicit segmentation. In a way, this is similar to the task of counting objects without directly counting them. Such calculations may, for example, be useful)Cast estimation of particle size in different application areas. The topic is that of estimating average size (=average diameter) of packed particles, from formulas involving edge density, and the edges from moment-based thresholding are used. An average shape factor is involved in the calculations, obtained for some frames from crude partial segmentation. Measurement results from about 80frames have been analyzed. 相似文献
80.
文中给出回传通道调试的相关研究成果,介绍回传通道的前端信号处理、光纤链路调节、电缆分配网设置的方法,提出采用等效数字调制信号源、通过测试回传通道NPR性能评价回传通道质量的实用测试方法. 相似文献