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271.
<正>Many studies have shown that knowledge resources have been the real source of innovation and competitiveness of real estate enterprises.Therefore,it is the basic work to establish the real estate enterprise knowledge resources framework for implementing knowledge management(KM),and it should be given enough attention.A sort of the real estate enterprise knowledge resources framework system has been built in this paper based on the thought of Clark Henderson' s enterprise knowledge classification,and the contents have been analyzed and expounded.Thus,the real estate enterprises can grasp clearly the basic contents of its knowledge resources,then depict the knowledge system,in the end the solid foundation should be settled for implementing knowledge management. 相似文献
272.
Hydrogels resulting from the self-assembly of small peptides are smart nanobiomaterials as their nanostructuring can be readily tuned by environmental stimuli such as pH,ionic strength and temperature,thereby favoring their practical applications.This work reports experimental observations of formation of peptide hydrogels in response to the redox environment.Ac-I 3 K-NH 2 is a short peptide amphiphile that readily self-assembles into long nanofibers and its gel formation occurs at concentrations of about 10 mmol/L.Introduction of a Cys residue into the hydrophilic region leads to a new molecule,Ac-I 3 CGK-NH 2,that enables the formation of disulfide bonds between self-assembled nanofibers,thus favoring cross-linking and promoting hydrogel formation.Under oxidative environment,Ac-I 3 CGK-NH 2 formed hydrogels at much lower concentrations(even at 0.5 mmol/L).Furthermore,the strength of the hydrogels could be easily tuned by switching between oxidative and reductive conditions and time.However,AFM,TEM,and CD measurements revealed little morphological and structural changes at molecular and nano dimensions,showing no apparent influence arising from the disulfide bond formation. 相似文献
273.
探讨一类含对流项抛物方程的只含有时间变量热源识别反问题.这类问题是不适定的,即问题的解不连续依赖于测量数据.利用简化的Tikhonov正则化方法和拟逆正则化方法分别得到问题的正则近似解,并且分别给出正则解和精确解之间具有Ho¨lder型误差估计. 相似文献
274.
基于出行需求的交通服务(DRT,Demand Responsive Transport)就出行者的需求可以迅速地提供相应的出行服务,同时在应对个性化出行需求方面比常规公共交通方式更具时间和空间上的灵活性.作为近年来客运交通领域的一次革新,在欧美发达国家已经得到了较为广泛的应用.立足于DRT的基本理论,探索了DRT模式下... 相似文献
275.
A tidal bore is a unique Earth surface process, characterized by its highly destructive energy, predictable periodicities and magni-tudes, and the production of characteristic sedimentary features. Tidal bores and associated rapid flood flows are highly turbulent flows of the upper-flow regime with a velocity over several meters per second. Reynolds (Re) and Froude (Fr) numbers, respectively, are larger than 104 and 1.0, making them significantly different from regular tidal flows but analogous to turbidity currents. Until now, understanding of tidal-bore depositional processes and products has been limited because of the difficulty and hazards involved with gauging tidal bores directly. The Qiantang bore is known as the largest breaking bore in the world. Field surveys were carried out in May 2010, along the north bank of the Qiantang Estuary to observe the occurrence of peak bores, including regular observations of current, water level and turbidity at the main channel. Several short cores were sampled on the intertidal flats to study the characteristic sedimentary features of tidal bores. Hydrodynamic and sedimentological studies show that the processes of sediment resuspension, transport and deposition are controlled primarily by the tidal bores, and the subsequent abruptly accelerated and decelerated flood flows, which only account for one tenth of each semidiurnal tidal cycle in the estuary. Tidal-bore deposits are generally poorly sorted because of rapid sedimentation after highly mixed suspension by intense turbulence. This behavior is characteristic of the absence of tractive-current depositional components in a C-M diagram. It also goes along with well-developed massive bedding, graded bedding, basal erosion structures, convolute bedding and dewatering structures. Together, these sedimentary features can constitute fingerprinting of turbidites, widely distributed in the deep-water environment. However, a tidal bore is triggered by intensely deformed tidal waves propagating into a shallow-water environment, which returns to regular tidal flows rapidly after the passage of the bore head. The tidal-bore deposits are usually bounded by the intertidal-flat deposits with typical tidal beddings at the top and on both flanks. The difference between tidal-bore deposits (TBD) and tidal sandy/muddy deposits (TSD/TMD) is evident not only in sedimentary structures, but also in the grain-size composition. They can be clearly distinguished in grain-size bivariate plots, typically the plot of mean grain size vs. standard deviation (or sorting). Some trend variations generally exist in mean grain size with TBD>TSD>TMD, sorting with TMD>TBD>TSD (larger value indicating poorer sorting), and both skewness and kurtosis with TSD>TBD>TMD. These findings will undoubtedly shed new light on our understanding of tidal-bore sedimentology, ancient tidal-bore sedimentary facies and environments, and related oil-and-gas field prospecting. 相似文献
276.
近年来,随着科学技术的迅猛发展,新型高分子材料在煤矿得到广泛应用,国内大部分生产矿井随着采深加大,巷道压力明显提高,尤其是综采工作面,在周期来压前后,出现大量片帮、冒顶,严重制约产量,并对安全生产提出严峻考验.化学加固材料在煤体合理加注后,可以有效提高煤壁硬度,有效控制片帮、冒顶事故,为均衡、正规、安全生产提供有效保障. 相似文献
277.
多重微孔颗粒生物反应床是我公司研究开发的一种经济且能强有效去除垃圾渗滤液中污染物的反应器。本文先对矿化垃圾填料和多重微孔颗粒填料的挂膜性能和粒径分布进行比较,再以上海老港垃圾填埋场调节池出水为研究对象,构建多重微孔颗粒反应床的小试模型,对比20℃条件下反应柱和多重微孔颗粒反应柱对COD、NH3-N、TN指标的去除效果。 相似文献
278.
279.
图书馆是大学最具标志性的建筑之一,它除了具有文献收藏检索、科技信息服务、学术交流研究等功能外,还应该体现一所大学的文化,体现出强烈的时代特征和人文关怀.以华中师范大学新图书馆建筑设计方案为例,探讨了当代大学图书馆建筑设计中的文化要素. 相似文献
280.
食饵具有感染率的捕食-被捕食系统可以用来解释生命科学中的很多现象,该问题已经被很多学者研究。在人口动力学中,收获率对物种有重要的影响。研究了一类具有收获的食饵有感染的时滞三维捕食-被捕食模型的稳定性,同时发现当参数经过一系列临界值时,系统产生Hopf分支现象。数值仿真证明了理论结果。 相似文献