67 resultados para 785

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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针对海上油田大斜度油井的多相流测量问题,首先分析海上油田油井多相流测量面临的困难,阐述测试施工、资料解释所采取的对策以及测试仪器在大斜度井中的实验结果,最后介绍油井多参数测试仪器在渤海油田中的测量应用情况。

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A newly developed numerical code, MFPA(2D) (Material Failure Process Analysis), is applied to study the influence of stochastic mesoscopic structure on macroscopic mechanical behavior of rock-like materials. A set of uniaxial compression tests has been numerically studied with numerical specimens containing pre-existing crack-like flaw. The numerical results reveal the influence of random mesoscopic structure on failure process of brittle material, which indicates that the variation of failure mode is strongly sensitive to the local disorder feature of the specimen. And the patterns of the crack evolution in the specimens are very different from each other due to the random mesoscopic structure in material. The results give a good explanation for various kinds of fracture modes and peak strength variation observed in laboratory studies with specimens made from the same rock block being statistically homogenous in macro scale. In addition, the evolution of crack is more complicated in heterogeneous cases than in homogeneous cases.

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The present paper describes a systematic study of argon plasmas in a bell-jar inductively coupled plasma (ICP) source over the range of pressure 5-20 mtorr and power input 0.2-0.5 kW, Experimental measurements as well as results of numerical simulations are presented. The models used in the study include the well-known global balance model (or the global model) as well as a detailed two-dimensional (2-D) fluid model of the system, The global model is able to provide reasonably accurate values for the global electron temperature and plasma density, The 2-D model provides spatial distributions of various plasma parameters that make it possible to compare with data measured in the experiments, The experimental measurements were obtained using a tuned Langmuir double-probe technique to reduce the RF interference and obtain the light versus current (I-V) characteristics of the probe. Time-averaged electron temperature and plasma density were measured for various combinations of pressure and applied RF power, The predictions of the 2-D model were found to be in good qualitative agreement with measured data, It was found that the electron temperature distribution T-e was more or less uniform in the chamber, It was also seen that the electron temperature depends primarily on pressure, but is almost independent of the power input, except in the very low-pressure regime. The plasma density goes up almost linearly with the power input.

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The effect of alcohol solution on single human red blood Cells (RBCs) was investigated using near-infrared laser tweezers Raman spectroscopy (LTRS). In our system, a low-power diode laser at 785 nm was applied for the trapping of a living cell and the excitation of its Raman spectrum. Such a design could simultaneously reduce the photo-damage to the cell and suppress the interference from the fluorescence on the Raman signal. The denaturation process of single RBCs in 20% alcohol solution was investigated by detecting the time evolution of the Raman spectra at the single-cell level. The vitality of RBCs was characterized by the Raman band at 752 cm(-1), which corresponds to the porphyrin breathing mode. We found that the intensity of this band decreased by 34.1% over a period of 25 min after the administration of alcohol. In a further study of the dependence of denaturation on alcohol concentration, we discovered that the decrease in the intensity of the 752 cm(-1) band became more rapid and more prominent as the alcohol concentration increased. The present LTRS technique may have several potential applications in cell biology and medicine, including probing dynamic cellular processes at the single cell level and diagnosing cell disorders in real time. Copyright (c) 2005 John Wiley T Sons, Ltd.

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A deep-etched polarization-independent binary fused-silica phase grating as a three-port beam splitter is designed and manufactured. The grating profile is optimized by use of the rigorous coupled-wave analysis around the 785 nm wavelength. The physical explanation of the grating is illustrated by the modal method. Simple analytical expressions of the diffraction efficiencies and modal guidelines for the three-port beam splitter grating design are given. Holographic recording technology and inductively coupled plasma etching are used to manufacture the fused-silica grating. Experimental results are in good agreement with the theoretical values. (c) 2008 Optical Society of America.

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在“神光-Ⅱ”装置上进行先进高能多功能激光束系统(简称第九路)研制工程中,由于在原ICF靶室上又增加了输入“汤姆逊探针光”和“X光背光照明探针光”的锥形真空套筒及其终端光学元件,导致原有靶室结构的变化,可能会引入新的不稳定因素.通过有限元分析方法,建立有限元分析模型,进行优化设计.通过位移传感器测量结果可知,第九路终端光学元件径向窜动所引起的打靶误差最大值为2.110 μm,小于“神光-Ⅱ”靶场终端光学系统的最大允许误差值7.785 μm.

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采用提拉法生长Y3Al5O12(YAG)晶体和Yb3+掺杂原子数分数分别为5%, 10%, 15%, 20%, 25%, 50%和100%的Yb∶Y3Al5O12(Yb∶YAG)晶体。系统表征和分析了Yb3+掺杂浓度对拉曼光谱的影响。随着Yb3+掺杂浓度的增加,晶体的振动模式没有明显的变化,晶体结构没有改变;在370 cm-1和785 cm-1附近,振动吸收峰的半峰全宽逐渐增大。分析得出,Yb3+掺杂浓度对晶体的晶格、对称性、荧光寿命均有影响,从而可能影响到晶体的光谱和激光性能。

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本文综述了草原群落土壤呼吸研究的理论、方法、最新进展和主要成果。从2001年6月5日到10月15日,在内蒙古锡林河流域的一个典型草原群落放牧地段用气相色谱法对土壤呼吸进行了测定,并同期观测相应的环境因子,分析了它们之间的相互关系,并根据根系生物量和土壤呼吸的相关性外推出根系呼吸占土壤总呼吸的比例。同时,采用碱液吸收法对该草原群落和一个沼泽化草甸群落的土壤呼吸进行了比对测定,比较在不同生境下土壤呼吸速率的差异。另外,重点比较了两种常用的土壤呼吸测量方法——碱液吸收法和气相色谱法对典型草原群落土壤呼吸的测量效果。主要研究成果如下: 1.在草原群落,生物量(包括地上和地下生物量)、温度(包括气温和土壤温度)和水分及土壤呼吸的季节变化均呈不规则的波动曲线;土壤呼吸与土壤湿度高度相关,与温度尤其是土壤温度以及地下生物量之间存在着一定的相关性,但和地上生物量及绿色生物量之间几乎没有关系。 2.草原群落和草甸群落土壤呼吸的季节动态基本一致,均出现了两个峰值,分别出现在6月底和7月底,它们的变化范围分别为312.8~1738.9 mg C﹒m-2﹒d-1 和 354.6 ~2235.6 mg C﹒m-2﹒d-1,日平均土壤呼吸速率分别为785.9 mg C﹒m-2﹒d-1 和1349.6 mg C﹒m-2﹒d-1,草甸群落的土壤呼吸速率明显高于草原群落; 3.土壤水分是草原群落土壤呼吸的主要限制因子,但对草甸群落的土壤呼吸变化却基本没有影响;草甸群落中,地上总生物量与土壤呼吸速率间没有显著的相关关系,但地上部分绿色生物量与土壤呼吸间存在着显著的幂函数关系,而在草原群落中,土壤呼吸速率与地上活生物量或地上总生物量的相关关系均很弱。 4.在草原群落,根系呼吸占土壤总呼吸的比例为60.7% - 93.3%,平均为82%; 5.碱液吸收法和气相色谱法的测定结果具有很高的相关性(R2=0.7563),它们的季节动态基本一致,变化范围分别为从249.3~1795.1 mg C﹒m-2﹒d-1和从312.8~1738.9 mg C﹒m-2﹒d-1,平均值分别为634.2 mg C﹒m-2﹒d-1和802.7 mg C﹒m-2﹒d-1,碱液吸收法的测量值是气相色谱法的约1.4倍。

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以线二色光谱为主对色素分子在光合膜中的取向及其变化进行了研究。 测定并分析比较了数种高等植物的叶绿体或类囊体的线二色光谱,以及捕光色素蛋白复合体和光系统Ⅱ颗粒的线二色光谱,对谱中各成分及其取向作出推测。对比不同种和不同生长条件植物类囊体线二色光谱,表明色索分子在膜中定向相对稳定,肯定了光合膜具有液晶特性。 通过十八碳不饱和脂肪酸对类囊体线二色光谱的影响的分析研究,确定亚麻酸和亚油酸可改变膜内侧叶绿素分子在膜中的取向,而对外周天线色素分子的取向影响不大,推测亚麻酸分子的疏水尾部进入腹内疏水区对内部叶绿素蛋白复合体发生作用。 对小麦黄化苗转绿过程的研究,发现类胡罗卜素分子在黄化质体中取向异常,方向与腹垂直,在连续照光时期有翻转过程,最终趋于与膜平行,变得有利于光能传递。

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本实用新型主要涉及一种用于核物理实验的高性能的时间拾取装置的结构。一种高性能时间拾取装置,包括有壳体(1),壳体(1)上设有与束流管线连接的孔(11),其主要特点是还包括有在壳体(1)内设有表面为椭球面的光反射空腔(12),在椭球面的光反射空腔(12)的垂直轴线上设有塑料闪烁薄膜(2),塑料闪烁薄膜(2)的中心与椭球面的光反射空腔(12)的上焦点(A)重合,壳体(1)上的孔(11)的中心线穿过椭球面的光反射空腔(12)的上焦点(A);在椭球面的光反射空腔(12)的下焦点(B)处设有光电倍增管(4)的接收面。本实用新型的优点是具有高时间分辨、高计数率能力、低探测阈、耐辐照。其探测效率对于中能次级束达到90%以上,时间分辨为140ps,在~10↑[8]个/秒离子强度辐照下,仍能正常工作。它的结构简单,性能稳定,价格低廉,容易操作,是中能重离子实验中理想的时间探测器。

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研究采用PCR-SSCP技术研究番鸭不同就巢群体(就巢1月群、就巢2月群、就巢3月群)、番鸭非就巢群和白改鸭5个群体250个个体PRL基因第4外显子多态性与就巢性状之间的相关性.结果表明,在外显子4编码区内发现2个SNP位点,分别位于该基因的3 777 bp (T/C)和3 785 bp(A/C)处.基因型与就巢性状指标相关分析的结果表明,番鸭非就巢群体与各就巢群体间差异极显著(P<0.01),同时番鸭与白改鸭差异显著(P<0.05),推测PRL基因与就巢性有一定的相关.

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研究采用PCR-SSCP技术研究番鸭不同就巢群体(就巢1月群、就巢2月群、就巢3月群)、番鸭非就巢群和白改鸭5个群体250个个体PRL基因第4外显子多态性与就巢性状之间的相关性.结果表明,在外显子4编码区内发现2个SNP位点,分别位于该基因的3 777 bp(T/C)和3 785 bp(MG)处.基因型与就巢性状指标相关分析的结果表明,番鸭非就巢群体与各就巢群体间差异极显著(P<0.01),同时番鸭与白改鸭差异显著(P<0.05),推测PRL基因与就巢性有一定的相关.