273 resultados para 320.4477

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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A 320 kV high voltage (HV) platform has been constructed at Institute of Modern Physics (IMP) to satisfy the increasing requirements of experimental studies in some heavy ion associated directions. A high charge state all-permanent magnet ECRIS-LAPECR2 has been designed and fabricated to provide intense multiple charge state ion beams (such as 1000 e mu A O6+, 16.7 e mu A Ar14+, 24 e mu A Xe27+, etc.) for the HV platform. LAPECR2 has a dimension of 0 650 mm x 560 mm. The powerful 3D magnetic confinement to the ECR plasma and the optimum designed magnetic field for the operation at 14.5 GHz makes it possible to obtain very good performances from this source. After a brief introduction of the ECRIS and accelerator development at IMP, the conceptual design of LAPECR2 source is presented. The first test results of this all-permanent magnet ECRIS are given in this paper.

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Molar heat capacities of n-butanol and the azeotropic mixture in the binary system [water (x=0.716) plus n-butanol (x=0.284)] were measured with an adiabatic calorimeter in a temperature range from 78 to 320 K. The functions of the heat capacity with respect to thermodynamic temperature were established for the azeotropic mixture. A glass transition was observed at (111.9 +/- 1.1) K. The phase transitions took place at (179.26 +/- 0.77) and (269.69 +/- 0.14) K corresponding to the solid-liquid phase transitions of. n-butanol and water, respectively. The phase-transition enthalpy and entropy of water were calculated. A thermodynamic function of excess molar heat capacity with respect to temperature was established, which took account of physical mixing, destructions of self-association and cross-association for n-butanol and water, respectively. The thermodynamic functions and the excess thermodynamic ones of the binary systems relative to 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity and the calculated excess heat capacity with respect to temperature.

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UTT (Ultrasonic Tomography Tool) is widely used in the oil industry and can be used to inspect corrosion, casing wall damage, casing breakoff, and casing distortion in the well borehole with the maximum environment temperature being 125 °C, and the pressure being 60 MPa. UTT consists of tool head, upper centralization, electronic section, lower centralization, transmitters, and receivers. Its outer diameter is 4.6 cm and length is 320 cm. The measured casing diameter ranges from 60 mm to 254 mm. The tomography resolution is 512×512. The borehole measurement accuracy is 2 mm. It can supply 3D pipe tomography, including horizontal and vertical profile. This paper introduces its specification, measurement principle, and applications in oilfield.damage, casing breakoff, and casing distortion in the well borehole with the maximum environment temperature being 125 °C, and the pressure being 60 MPa. UTT consists of tool head, upper centralization, electronic section, lower centralization, transmitters, and receivers. Its outer diameter is 4.6 cm and length is 320 cm. The measured casing diameter ranges from 60 mm to 254 mm. The tomography resolution is 512×512. The borehole measurement accuracy is 2 mm. It can supply 3D pipe tomography, including horizontal and vertical profile. This paper introduces its specification, measurement principle, and applications in oilfield.

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研究了水平管内不同液相介质(水、油和不同浓度的CMC溶液)对气液两相间歇流动压降的影响.实验管道为内径50mm的透明有机玻璃管,从入口到分离器长约30 m,实验段由2个长3 m的水平管组成.共记录了320组不同表观流速下的压降信号:油相0.17~1.85 m/s,水相0.17~2.48 m/s,CMC溶液0.17~1.42 m/s,气相0.06~3.40 m/s.结果表明,液相为牛顿流体(油或水)的气液流动,随着表观气相流速的增大,压降呈增加趋势;非牛顿幂率流体(不同浓度的CMC溶液)的管道流动,当流动指数低于一定值时,压降随气相流量的增加呈降低趋势,并且低于单液相流动的压降.Lockhart-Martinelli模型过高地预测了气-非牛顿幂率流体两相的压降.

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本文综述了金属材料发生韧性断裂的裂尖钝化,孔洞成核和长大,孔洞-孔洞或孔洞-裂尖汇合导致裂纹扩展的物理特征,和描述这些特征的本构理论及物理模型。

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《非牛顿流体力学》一文介绍了由流变学发展起来的一门分支学科——非牛顿流体力学的发展简况、学科内容、研究动向和展望。作者陈文芳教授系英籍非牛顿流体力学专家,1979年来中国,几年来已为我国非牛顿流体力学的发展作出了贡献。作者还深切期望,在本世纪末能建立一个具有中国特色的非牛顿流体力学学派。

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<正> 1979年,日本宇航研究所的Hirano发表了一篇纤维增强层合板铺层角度优化的研究论文。他把与x轴成α_k和—α_k(k表示某一层)方向所铺设的纤维同种、数目相等、基体同一的一个层片定义为一个单层。各个单层之间可以不完全满足单层所定义的条件,这样就考虑到了由N个单层迭合起来的层合板沿厚度方向异质的情况。同时,他还限定各个单层厚度是相等的。每个单层可以取任意的角度。给出层合板的层数,寻求一组铺层角度——各个单层的角度,使临界载荷值最大。由于与迭代起始值有关,他一般是给出8种起始值,然后再从8组结果中挑选临界载荷最大者为最优铺层角度。

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<正> 根据Lejeune-Dirichlet定理,力学系统处于静平衡情形的稳定的充要条件是系统的势能在平衡位置具有极小值。对于旋转的力学系统(机械系统或液体系统)就不象这样简单了。早在100年前Thomson和Tait就指出了旋转力学系统具有长期稳定性(secular stability)和动力稳定性(dynamiC stability)的重要差别。对于旋转液体星准稳演化过程到底按哪一种稳定性判断,是一个争论近百年的问题。在本世纪50年代以前,Thomson,Tait,Poincare,Liapounoff,Darwin,Teans和Lamb等,主张“长期稳定是真实的稳定”,“是天体演化学唯一感兴趣的稳定”。基于这种观点建立的Jeans-Darwin双星分裂理论曾

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实验表明,在连续CO_2激光辐照下,Ge平行板透射光强度随时间呈准周期性的变化。基于平行平面板的多光束干涉理论,并考虑激光引起的温升对Ge片折射率和厚度的影响,得到的计算结果与实验相符合。这说明平行平面Ge在高功率连续CO_2激光作用下因折射率和厚度随温度的变化而具有一种动态的法布里-珀罗干涉效应。

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In this paper we explore techniques to identify sources of electric current systems and their channels of flow in solar active regions. Measured photospheric vector magnetic fields (VMF) together with high-resolution white-light and H filtergrams provide the data base to derive the current systems in the photosphere and chromosphere. Simple mathematical constructions of fields and currents are also adopted to understand these data. As an example, the techniques are then applied to infer current systems in AR 2372 in early April 1980. The main results are: (i) In unipolar sunspots the current density may reach values of 103 CGSE, and the Lorentz force on it can accelerate the Evershed flow, (ii) Spots exhibiting significant spiral pattrn in the penumbral filaments are the sources of vertical major currents at the photospheric surface, (iii) Magnetic neutral lines where the transverse field was strongly sheared were channels along which strong current system flows, (iv) The inferred current systems produced oppositely-flowing currents in the area of the delta configuration that was the site of flaring in AR 2372.

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对滑坡监测的特点及国内外滑坡监测技术的发展现状进行简要的介绍,对无线实时遥测技术在滑坡监测中的应用现状做必要的综述,对KLA1型地表位移遥测系统的工作原理进行阐述,并详述阐述将遥测系统应用于三峡库区奉节天池滑坡应急监测的具体情况。KLA1型地表位移遥测系统是测量地表相对位移的监测仪器,在宜昌茅坪、重庆北碚、重庆万州枇杷坪等地已实际应用。该系统由三部分组成,分别为位移传感装置、数据采集发射模块、数据接收处理终端。在实际监测过程中,当滑体滑动时,监测点相对于固定点有线位移,这一信息由角位移传感器记录并转化为相应的电学量,电学量由无线发射模块通过GSM网络发射至远程终端,PC机作为终端通过相应的监测软件进行数据的接收及分析。通过奉节天池滑坡实测数据的分析,给出天池滑坡滑体位移随时间的变化曲线,预测此滑坡未来的发展趋势,证明监测设备的准确性、实时性,并说明此种监测技术运用于滑坡监测具有很高的实用价值。

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通过对固体中波动问题的模拟建立了一种光滑粒子法的新形式,一种运用SPH的核函数的类似有限体积法的计算方法.通过对统计体积的修正以及对边界粒子的核函数修正,较好地解决了SPH方法中长期以来制约其被广泛应用的主要问题之一边界条件的表述.在此基础上成功地在光滑粒子法中实现了透射边界条件的模拟.同时利用反卷积修正使得较大粒子间距下的计算结果的精度大大提高.这种方法不但保持了SPH的简单性,而且很容易实现应力边界条件.