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841.
The shear-wave splitting was analyzed on the deep seismic sounding profile crossing the Dabieshan area. The direction difference
between Sg and SmS fast wave polarization indicates that the modem regional tectonic stress field in the Dabieshan area exists
only in uppcr crust, while the crack alignment caused by the Triassic collision between the North China and the Yangtze blocks
had been preserved in mid-lower curst. 相似文献
842.
Identification and classification of subspecies of Asian cultivated rice and their hybrids 总被引:2,自引:0,他引:2
Xiangkun Wang Renhua Li Chuanqing Sun Zichao Li Hongwei Cai Xinli Sun 《科学通报(英文版)》1998,43(22):1864-1864
Having reviewed the major classification systems proposed by various scholars across the world, it is found thatindica andjaponica underO. sativa L. are two major directions thoroughly differentiated from the Asian cultivated rice, forming the framework of the classification
structure. A system withindica andjaponica as the only two subspecies is therefore reiterated. There are various ways to determine the indica-japonica identity of hybrid
rice, but the “combined morphological trait index” (CMT index) method is more efficient and easier to handle, although the
isozyme analysis, molecular marker analysis and grain quality assay methods are also feasible. 相似文献
843.
Carbon isotope anomaly in marbles associated with eclogites from the Dabie Mountains 总被引:1,自引:0,他引:1
This is a report of carbon isotope anomaly in marbles associated with the UHP eclogites from the Dabie Mountains. The results
place constraints on the degree of crust-mantle interaction during the UHP metamorphism. 相似文献
844.
An all solid-state electrochromic smart window employing prussian blue and electrodeposited WO3 film with poly (vinyl chloride) (PVC) gel electrolyte that has high conductivity (2 mS/cm) at room temperature has been fabricated
for the first time. The smart window has beell found to be excellent for electrochromism and memory characteristics. 相似文献
845.
In order to ascertain the mechanism of interaction between carbide and metallic catalyst and formation of diamond under high pressure and high temperature, and find a new method to synthesize diamond with special properties, it is necessary to investigate the reaction behavior of different carbides and metallic solvent_catalysts under high pressure and high temperature. A system of Cr-3C-2 powder and Ni 70Mn 25Co 5 alloy in weight ratio of 1∶6 was treated under 6 0 GPa and 1 500℃ for 20, 30 or 60 min respectively. X_ray diffraction of the samples indicated the Cr 3C 2 decomposed partially after high pressure and temperature treatment, and Cr 7C 3, Cr and diamond formed respectively. There was not any trace of graphite in the samples. The result suggested that the separated carbon atoms could form diamond directly without conversion process of graphite into diamond. The observation of SEI, WDX and EDX also showed that diamond crystals were synthesized in the system, which have perfect surfaces and shapes, with the average grain size of about 40 μm. The properties of the crystals are being investigated. 相似文献
846.
单向耦合映象格子的时空混沌同步 总被引:1,自引:1,他引:0
用主动-被动分拆方法实现了单向耦合映象格子系统的时空混沌同步,从理论上给出步范围,并从数值实验上得到验证。该法具有高度保密性,且信号可以完全恢复,特别适用于混沌保密通讯 。 相似文献
847.
Qun Chen 《科学通报(英文版)》1998,43(21):1780-1780
Harmonic maps with potential from complete manifolds are considered. This is a new kind of maps more general than the usual
harmonic maps relating to many interesting problems such as equilibrium system of ferromagnetic spin chain and Neumann motion.
Aiming at the general properties, the author derives basic gradient estimates and then Liouville type results for these maps,
which are interesting in constrast to those of the usual harmonic maps for the presence of potentials. 相似文献
848.
Ming Tan Dongsheng Liu Hua Zhong Xiaoguang Qin Hongchun Li Shusen Zhao Tieying Li Jinbo Lu Xiangyang Lu 《科学通报(英文版)》1998,43(6):506-506
Within the East Asian monsoon zone the change in oxygen isotope of Holocene stalagmite is mainly related to monsoon rain rather than to temperature. And carbon isotope can be taken as a comprehensive signal which contains the natural information and the information of anthropogenic activity. Isotopic analysis is also compared with the annual layer records. 相似文献
849.
介绍铁路站场CAD系统中面向对象用户界面的设计与研究,该系统用户界面的设计充分分考虑了铁路站场CAD系统的特点和工程应用,采用面向对象的方法与技术,实现了一个高度图形化和交互式,适用于铁路站场设计工作需要的图用户界面。 相似文献
850.
该文研究了一为具有时变参数或扰动的非线性系统的鲁棒轨迹跟踪控制问题,假定系统的标称模型是可以反馈线性化的,通过递推构造壮环系统地的Lyapunov函数,给出了该类不确定系统鲁棒输出跟踪控制器设计方案。该控制器能保证闭环系统的状态是一致有界的,且通过对控制器参数的适当选择,可使闭环系统的输出跟踪达到指定的精度要求,最后由一机器人控制系统的仿真研究表明,该文提出了控制方案具有很强的鲁棒性,控制效果是令 相似文献