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951.
Axisymmetrie fundamental solutions that are applied in the consolidation calculations of a finite clay layer with impeded boundaries were derived. Laplace and Hankel integral transforms were utilized with respect to time and radial coordinates, respectively in the analysis. The derivation of fundamental solutions considers two boundary-value problems involving unit point loading and ring loading in the vertical. The solut-ions are extended to circular distributed and strip distributed normal load. The computation and analysis of set-tlements, vertical total stress and excess pore pressure in the consolidation layer subject to circular loading are presented.  相似文献   
952.
Lipophilic tea polyphenols (LTP) were prepared by catalytic esterifieation of green tea polyphenols (GRIP) with hexadeeanoyl chloride. A novel long-chain aeyl-derivative of epigalloeateehin-3-o-gallate(EGCG) was first isolated from purification of LTP by high-speed eountereurrent ehromatography (HSCCC)using a solvent system composed of n-hexane-ethyl acetate-methanol-water ( 1 : 1 : 1 : 1, v/v) . The moleeularstructure of the acyl-derivative, Epigallocatechin-3-O-gallate-4‘-O-hexadeeanate , was elucidated by meansof elemental analysis, IR, 1H-NMR and MS spectra.  相似文献   
953.
In the peralumineous granite of Yajiangqiao zircon population can be divided into two groups (i.e. Zircon Ⅰ and Zircon Ⅱ), which were formed in magmatic chamber and in emplacement place, respectively. The Hf isotope compositions of two stages of zircon show that the host magma was essentially derived from crustal material by melting. However, some higher 176Hf/177Hf ratios indicate that the granitic zircons should contain fine crystal of zircon formed in mantle-derived magma. In fact, the backscattered electron imaging and the electron microprobe analysis reveal that there is another type of zircon included within Zircon Ⅰ, which is quite different from Zircon Ⅰ and Zircon Ⅱ in morphology and chemistry. They are considered to be the product of the mantle-derived magma intruded into the granitic magma chamber at the beginning of anatexis. Thus,it is suggested that the formation of Yajiangqiao granite is related to the underplating of mantle magma.  相似文献   
954.
Eclogite cobbles were discovered by Wang et al. (2001) in the Fenghuangtai Formation of the northern margin of Dabie Mountains in the Dushan area of Anhui Province, China[1]. They proposed that after the formation during the Triassic, the high-pressure (HP) and ultra-high-pressure (UHP) metamorphic rocks reached the sur-face through exhumation and uplifting before the late Ju-rassic. However, they have not provided any evidence about isotopic ages. One kind of cobbles of HP-UHP rocks w…  相似文献   
955.
A series of 1,8,15,22-tetra(2,4-ditertbutylphen-oxy) phthalocyanines [α-(oAr)4PcM,M1=(H)2,M2=Pd,M3=Cu,M4=Zn,M5=Pb] were synthesized in this study.Each compound was bromized in two kinds of solvent.One is the solvent mixture of 1,1,2-trichloroethane and water,the other is 1,1,2-trichloroethane alone.The effects of solvent,bromine excess added and reaction duration on the bromization reaction were studied.The shift of maximum absorbance wave-length both is solution and in solid thin film was investigated comparatively,discovering that both were bathochromism but the former was more.TG data showed that the temperature of thermal decomposition decreased continuously with the increase of numbers of bromine.Finally,the fragments produced during the bromization of (OAr)4PcPb in 1,1,2-trichloroethane were characterized by GC/MS.Based on the electronic structure,the possible mechanism of decomposition of these compounds was presented and discussed.  相似文献   
956.
基于衍射特性分析的光纤布拉格光栅耦合模理论研究   总被引:1,自引:0,他引:1  
从衍射光学角度出发研究了光纤布拉格光栅的光学特性,进而采用理想模展开的耦合模理论对光纤布拉格光栅的模场分布进行了详细分析,推导出反射率、布拉格反射波长及反射主峰带宽等特征参数的表达式,具体计算结果表明理论与实际结果吻合较好,从而验证了理论的正确性。  相似文献   
957.
肖娟 《科学之友》2007,(20):130-131
介绍了统计工作在煤炭企业统计工作中的重要作用,并对煤炭企业如何做好统计工作,从3个方面进行了论述.  相似文献   
958.
探讨异丙酚的镇静遗忘效果,对200例在硬膜外麻醉下行下腹部手术的患者在手术中分别应用异丙酚或杜冷丁、氟哌利多,观察手术过程中的镇静遗忘效果.  相似文献   
959.
GJC4/100型高低浓度甲烷传感器是以高性能单片机为核心,以载体催化元件和热导元件为敏感元件来检测甲烷浓度的高精度、低功耗、高可靠性、智能型甲烷传感器,该传感器既可检测0~4%的低浓甲烷,又可检测4%~100%的高浓甲烷。已通过国家煤矿防爆产品安全质量检测检验中心进行的性能检验和防爆检验,取得了矿用安全标志准用证(MA认证),并在全国多家矿井推广应用。  相似文献   
960.
作者以自身实践出发,从5个方面论述了学校图书馆在学校教育中的作用。  相似文献   
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