排序方式: 共有93条查询结果,搜索用时 93 毫秒
31.
1Generalsituationofthecascades1.1Cascadeshydropowerplants HanjiangRiverisoneofthelongesttributariesof YangtseRiver,originatingfromNingqiangcountyof ShaanxiprovinceandflowingthroughShaanxi provinceandHubeiprovince.HanjiangRiveris1567kmlongintotal,and709kmofitinShaanXi provincerunsthroughHanzhongandAnkangregions fromtheeasttothewest.TheupperreachesofHanjiangfromYangxian countytoBaihecountyinShaanxiprovinceis443km long,anditstotalheadfallsisabout280mhigh.Withabundantwaterpowerresources,its… 相似文献
32.
Dong Mingkai male years old master of technology lecture. * Supported by the High Technology Research Deverlopment program of China 《西南师范大学学报(自然科学版)》1998,(5)
Extensionisthemostimportantconceptindefaultlogic.Reiterhadmadesomeresearchonthespecialkindofdefaultlogic,thatisnormaldefaultl... 相似文献
33.
He Ping male years old professor. * Supported by the Netherlands Organization for Scientific Research NWO 《西南师范大学学报(自然科学版)》1998,(5)
ThegenusFusaeawasfoundedbySaford[1]in1914.ThetypespeciesF.longifoliawasoriginalydescribedbyAublet[2]asAnnonalongifolia.Bailo... 相似文献
34.
对2,3-二氯-6-羧酰氯喹啉类活性染料的反应活泼性以及“染料-纤维”键的稳定性进行了反应动力学研究,测定水解速度常数;与其他类型活性染料进行比较,对此类活性染料性能进行了评价。 相似文献
35.
LIU Zhenrong 《系统科学与复杂性》1992,(4)
In this paper a mathematical model of chemical systems is investigated.We present the conditions for the existence and local stability of the steady statesand the periodic solution of the Hopf type.Specifically,we show by using an ana-lytical method that there may exist two or four Hopf bifurcation points separatedat a finite distance from each other;at the same time,a technique for studying theHopf bifurcation value is given. 相似文献
36.
以解决目前悬臂锥形钢管抗弯承载力计算为目的,考虑径厚比、失效长度、锥度等因素,推导管径较大端的径厚比在10~60情况下截面失效界限位置与不同锥度的对应关系,提出考虑失效区域的承载力计算设计理论;分析锥度0.1~1.0区间内钢管各截面的抗弯承载力并确定失效长度取值。在开展端部径厚比为30的情况下,锥度0.2、0.3、0.4、0.5悬臂钢管抗弯极限承载力和锥度0.4、0.5钢管失效长度的有限元验算工作,不论承载力和失效长度都与理论推导吻合较好,说明该理论达到了控制失效区域,避免塔体整体失效的设计目的。另编制锥度和失效长度的关系表供设计计算查询。 相似文献
37.
YAN Na GENG DeLu HONG ZhenYu & WEI BingBo* Department of Applied Physics Northwestern Polytechnical University Xi’an China 《科学通报(英文版)》2011,56(9):912-918
Al-27%Cu-5.3%Si ternary eutectic alloy was melted using a YAG laser and then solidified while being acoustically levitated. A maximum undercooling to 195 K (0.24 TL) was achieved with a cooling rate of 76 K/s. The solidification microstructure was composed of (Al+θ+Si) ternary eutectics and (Al+θ) pseudobinary eutectics. During acoustic levitation, the (Al+θ+Si) ternary eutectics are refined and the (Al+θ) pseudobinary eutectics have morphological diversity. On the surface of the alloys, surface oscillations and acoustic streaming promote the nucleation of the three eutectic phases and expedite the cooling process. This results in the refinement of the ternary eutectic microstructure. During experiments, the reflector decreases with increasing alloy temperature, and the levitation distance always exceeds the resonant distance. Because of the acoustic radiation pressure, the melted alloy was flattened, and deformation increases with increasing sound pressure. The maximum aspect ratio achieved was 6.64, corresponding to a sound pressure of 1.8×104 Pa. 相似文献
38.
NIE Jing LIU Lin ZHAO XiaoHang XIE Ping ZHOU PingKun XING GuiChun LIU XiangJun HE FuChu HAN WeiDong * & ZHANG LingQiang * Department of Molecular Biology General Hospital of Chinese People’s Liberation Army Beijing China State Key Laboratory of Proteomics Beijing Proteome Research Center Beijing Institute of Radiation Medicine Beijing Department of General Surgery Chi... 《科学通报(英文版)》2011,(30)
The tumor suppressor p53 locates at the key point of cell growth or apoptosis balance, and the expression level of p53 is tightly controlled by ubiquitin ligases including MDM2. Upon DNA damage stresses, p53 was accumulated and activated, leading to cell cycle arrest or apoptosis. We previously showed that Smad ubiquitylation regulatory factor 1/2 (Smurf1/2) promotes p53 degradation by interacting with and stabilizing MDM2, and consequently enhancing MDM2-mediated ubiquitylation of p53. However, it is uncle... 相似文献
39.
Gastric vagal afferent inputs reach the glycemia-sensitive neurons of lateral hypothalamic area in the rat 总被引:1,自引:0,他引:1
ZHANG Yueping* ZHU Jingning* JIANG Jianming & WANG Jianjun Department of Biological Science Technology Nanjing University Nanjing China * These two authors made equal contributions to this work. 《科学通报(英文版)》2003,48(6)
The lateral hypothalamic area (LHA) is one of the most important central areas in the regulation of feeding behavior[1]. The glycemia-sensitive neurons within the LHA sense the blood glucose level and subsequently trig-ger various visceral and somatic responses for maintaining the homeostasis of blood glucose concentration. Some electrophysiological studies have demonstrated that the gastric vagal afferent inputs could reach the LHA in the cat[2,3], but the studies did not reveal whether th… 相似文献
40.
基于MapReduce的粒子群投影寻踪模型的设计与实现 总被引:1,自引:0,他引:1
利用MapReduce模式设计并实现了粒子群投影寻踪算法的并行化,以提高算法的效率.在分类阶段使用了基于MapReduce的KNN分类算法并行,实验结果表明:基于MapReduce实现的粒子群投影寻踪模型能够有效地寻找到较好的投影方向,确保分类效果;并且与其串行算法相比,在实现效率上有较大的提高. 相似文献