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191.
采用3DSMAX三维动画技术构造原子轨道的角度函数图,通过动画演示,形象,直观地表达了原子轨道的形状特点,极值的方向和节面的位置。  相似文献   
192.
The unified chaotic system contains the Lorenz system and the Chen system as two dual systems at the two extremes of its parameter spectrum. This paper presents the design of bang bang controller for unified system and multitude of numerical experiments under various control parameters. Numerical experiments meet the theoretic proof perfectly and convincingly demonstrated the controller can be effectively used for unified systems with uncertainty of the equilibrium points. The method enriches the applications of chaotic control. Foundation item: Supported by the National Natural Science Foundation of China(50209012) Biography: Deng Xiao-ming (1980-), male, Master candidate, research direction: chaos control.  相似文献   
193.
The Lattice-Boltzmann method is an effective tool for solving fluid mechanics problems, but there isn’t still a good scheme to determinate some parameters in Boltzmann equations. In this paper, a technique using evolutionary algorithm to automatically model Boltzmann equations is introduced. Numerical simulation shows that the designed scheme is fast and efficient. Biography: Chen Ju-hua ( 1963-), male, Associate professor, research direction: Lattice-Boltzmann method, evolutionary algorithm.  相似文献   
194.
Xu L  Wei Y  Reboul J  Vaglio P  Shin TH  Vidal M  Elledge SJ  Harper JW 《Nature》2003,425(6955):316-321
Programmed destruction of regulatory proteins through the ubiquitin-proteasome system is a widely used mechanism for controlling signalling pathways. Cullins are proteins that function as scaffolds for modular ubiquitin ligases typified by the SCF (Skp1-Cul1-F-box) complex. The substrate selectivity of these E3 ligases is dictated by a specificity module that binds cullins. In the SCF complex, this module is composed of Skp1, which binds directly to Cul1, and a member of the F-box family of proteins. F-box proteins bind Skp1 through the F-box motif, and substrates by means of carboxy-terminal protein interaction domains. Similarly, Cul2 and Cul5 interact with BC-box-containing specificity factors through the Skp1-like protein elongin C. Cul3 is required for embryonic development in mammals and Caenorhabditis elegans but its specificity module is unknown. Here we report the identification of a large family of BTB-domain proteins as substrate-specific adaptors for C. elegans CUL-3. Biochemical studies using the BTB protein MEL-26 and its genetic target MEI-1 (refs 12, 13) indicate that BTB proteins merge the functional properties of Skp1 and F-box proteins into a single polypeptide.  相似文献   
195.
讨论了理想调节网络对三相电力负荷中的无功与三相不平衡进行完全调节的基本原理,给出了应用理想调节电纳与模糊c均值聚类算法提取负荷聚类特征的方法,聚类特征可用于用户电力调节系统的优化设计。工程实例表明了该方法的正确性与有效性。  相似文献   
196.
研究了在实验室条件下利用一次加碱法制备聚合氯化铝的过程中,总铝浓度及碱化度对聚合氯化铝中铝聚合形态组成的影响,结果表明随碱化度的提高,低浓PAC中Alc含量变化较小,而高浓PAC中Alc含量呈显著上升趋势;同时,低浓PAC中Alc的含量呈较明显增加,而高浓PAC中Alb含量则呈缓慢下降趋势;无论高浓还是低浓PAC,其Ala的含量均呈较显著的下降趋势.  相似文献   
197.
通过XRD、DTA-TG、SEM和EPMA等手段研究了富铁低碱度钢渣的水热反应、水热产物及其胶凝性.结果表明富铁低碱度钢渣的水热反应产物为水化钙铁石榴子石;富铁低碱度钢渣-石英砂体系的水热反应产物以Fe-tobemorite为主,蒸压强度显著提高;富铁低碱度钢渣-石灰体系的水热反应产物为高碱度的C2SH.  相似文献   
198.
注塑模模架设计KBE系统及其智能关键技术   总被引:7,自引:1,他引:7  
结合当前工程设计领域 KBE技术的发展和模架设计的数据流图 ,给出了注塑模模架设计KBE系统的基本框架 ,并对其关键技术进行了分析 :模架设计知识采用框架 -规则的方法表示 ,并给出了推理的流程图 ,通过面向子目标的方法提高了 KBE系统的知识表示和推理能力 ;将事例推理的方法结合在 KBE系统中 ,提高了系统对以往成功事例的参考能力 ;利用神经网络的自学习能力 ,解决了模架中镶块和前后模设计的计算问题 .通过实际的应用 ,该系统能够有效地提高模具企业的模具设计和分析能力  相似文献   
199.
The exponential Radon transform, a generalization of the Radon transform, is defined and studied as a mapping of function spaces. It is represented in terms of Fourier transform of its domain and range, and this leads to the harmonic decomposition reconstruction. The results are similar results of Tretiak and Metz. Foundation item: Supported by the National Natural Science Foundation of China (No. 19971064), Key Project of Science and Technology of Hubei Province Education Committee. Biography: Wang Jin-ping (1963-), male, Ph.D. candidate, research direction: numberical solution of singular integral equation and integral transformation etc.  相似文献   
200.
The current study was to investigate mRNA expression of cyclin D2 and p16 during the transition from cardiac myocyte hyperplasia to hypertrophy. Cultured cardiac myocytes (CM) and fibroblasts (FC) obtained from 1-day-old Sparague-Dawley rats were used in this study. We have determined (1) hyperplasia by cell growth curve and fluorescence activated cell sorting (FACS); and (2) ultrastructure by electron microscope observation; and (3) expresions of cyclin D2 mRNA and p16 mRNA by using in situ hybridization and image analysis. The results were shown (1) Results of cell growth curve and FACS analysis showed CM could proliferate in the first 3 cultured days (4 days in postnatal development). But the ability decreased quickly, concomitant with the differentiation. (2) The ultrastructure of CM showed the large amount of myofilaments and mitochondrion and FC showed moderate amount of rough endoplasmic reticulum. (3) The expression of cyclin D2 mRNA in 3−, 4−, 5−day CM group was 0.89 times (p<0.05), 0.80 times (p<0.05) and 0.56 times (p<0.01) of that in 1-day group respectively. P16 mRNA in 2−, 3−, 4−, 5−day CM group were 1.63 times (p<0.01), 1.72 times (p<0.01), 1.99 times (p<0.01) and 2.84 times (p<0.01) of that in 1−day group respectively. It can be concluded that cultured neonatal rat cardiac myocytes could proliferate during the first 3 cultured days, but the ability of proliferation decreased, from the fourth day, concomitant with differentiation. Cyclin D2 and p16 have the key roles during the transition from myocyte hyperplasia to hypertrophy. Biography: Zhang Yu-xia (1974-), female, Master, research direction: cardiovascular pathology.  相似文献   
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