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81.
LEI Peng CHANG XiaoLin XIAO Feng ZHANG GuiJin & SU HuaiZhi School of Hydraulic Engineering Changsha University of Science Technology Changsha China College of Water Resources Hydroelectric Engineering Wuhan University.Wuhan Mid-south Design Research Institute China Hydropower Engineering Consulting Group Co Changsha College of Water Conservancy Hydropower Engineering Hohai University Nanjing 《中国科学:信息科学(英文版)》2011,(6)
Owing to the deficiency in early warning for high concrete dam,a formula was established to characterize the deformation behavior of high concrete dam as a whole.The early warning index of spatial deformation was calculated by low probability principle on the basis of the deformation entropy formula proposed.The steps were as follows.Firstly,the probability method was utilized to define the degree of order and degree of chaos for each survey point.Secondly,the weight distribution among the survey points was... 相似文献
82.
导管架式海洋平台在随机波浪等外载荷作用下极易产生有害振动,且其动力响应具有极强的非线性和时变性,采用被动控制方法和基于精确数学模型的主动控制方法控制海洋平台的有害振动很难达到理想的控制效果.结合灰预测和支持向量机的优点,提出了基于灰预测和支持向量机的自适应逆控制方法,并将其与动态刚度阵法相结合应用于导管架式海洋平台的振动主动控制中.数值算例分析表明,该控制方法可有效地控制波浪和风载荷作用下引起导管架式平台的有害振动,并能解决由于控制信号传输等原因引起的时滞问题. 相似文献
83.
本文介绍了基于某些名、优农产品在其生长过程中所需要的特定敏感元素,配制出“仿土质”专用肥。经施用证明,肥效显著,经济效益可观,具有推广应用的前景。 相似文献
84.
Cu–dinitro–diamino phthalocyanine was synthesized and converted to the diazonium salt. Polyacrylamide bonded CuPc(NO2)2 [PAA–CuPc(NO2)2] (I) was synthesized by hot polymerization of acrylamide and this diazonium salt. Polymer(I) is water soluble and contains about 7 mol % CuPc(NO2)2 rings, which are covalently bonded to PAA. Polymer(I) shows good photoconductivity, which is much better than that of the corresponding phthalocyanine monomers. By doping with iodine (I2), the photosensitivity of polymer(I) is increased, which through fluorescence analysis is explained by the fact that a charge–transfer complex (CTC) of polymer(I) with I2 is formed. The influence of interface layer (IFL) and charge–transportation material (CTM) on the photoconductivity of polymer(I) were also studied. 相似文献
85.
86.
Tungsten oxide (WO3) nanorods array prepared using chemical vapor deposition techniques was studied. The influence of oxygen gas concentration
on the nanoscale tungsten oxide structure was observed; it was responsible for the stoichiometric and morphology variation
from nanoscale particle to nanorods array. Experimental results also indicated that the deposition temperature was highly
related to the morphology; the chemical structure, however, was stable. The evolution of the crystalline structure and surface
morphology was analyzed by scanning electron microscopy, Raman spectra and X-ray diffraction approaches. The stoichiometric
variation was indicated by energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. 相似文献
87.
In this paper, we propose a new hard problem, called bilateral inhomogeneous small integer solution (Bi-ISIS), which can be seen as an extension of the small integer solution problem on lattices. The main idea is that, instead of choosing a rectangle matrix, we choose a square matrix with small rank to generate Bi-ISIS problem without affecting the hardness of the underlying SIS problem. Based on this new problem, we present two new hardness problems: computational Bi-ISIS and decisional problems. As a direct application of these problems, we construct a new lattice-based key exchange (KE) protocol, which is analogous to the classic Diffie- Hellman KE protocol. We prove the security of this protocol and show that it provides better security in case of worst-case hardness of lattice problems, relatively efficient implementations, and great simplicity. 相似文献
88.
Considering the randomness or interval character of physical parameters and applied loads of composite pressure vessels (COPV), the COPV reliability-analyzing model is built. And then the computational expressions for the mean value, standard deviation and deviation of fiber stress are deduced by the random factor method. The probabilistic and interval reliability designs on COPV are implemented by utilizing the probabilistic method and interval method combined with the improved particle swarm optimization (PSO) algorithm, respectively. The influence of fluctuation of structure uncertain parameters on COPV design thickness is inspected. Finally, examples are given to demonstrate that both probabilistic and interval reliability methods can satisfy the safety requirement and both are of higher rationality than the traditional safety factor method. And probabilistic method has a lower relative error but a higher computational complexity contrasted with the interval method. 相似文献
89.
针对我国当前网络政治参与中存在着非法参与行为多、政务信息不公开致使公众政治参与缺乏信息基础、政府对公众网络政治参与的行为与观点缺乏回应等问题,本文提出了采取完善政治参与和网络政治参与的法治化机制,建立健全网络参政相关法规,保障公民网络参政议政权益,规范和打击非法政治参与行为;修改政府信息公开的法律法规,加大政府信息公开力度与规范网络监督机制;建立政府对公民网络政治参与的回应制度,以解决公民网络政治参与的相关问题,推动法治文明. 相似文献
90.
Nanocrystalline titania films codoped with aluminum and boron were prepared by cathodic vacuum arc deposition. In the process, titanium alloy target was used under an O2/Ar atmosphere, and sensitization of films were carried out by natural dye-sensitized complex in anhydrous ethanol. The structure, surface morphology and UV-vis spectra of titania films codoped were measured by X-ray diffraction analysis, scanning electron microscopy and ultraviolet-visible spectrometer. Theas-deposited films are found to be amorphous. The films annealed were examinedto be of anatase structure with orientation along the (101) planes, the averagecrystal size is in the range between 41 and 45 nm. SEM results show that thereare some pores in the codoped titania films, the optical properties of the dye-sensitized films were also measured which reveals that the spectral responses of films shift to the visible region. Under simulated sunlight illumination, the overall energy conversion efficiency of dye-sensitized nanocrystalline solar cell is 0.9%. 相似文献