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排序方式: 共有744条查询结果,搜索用时 78 毫秒
101.
102.
介绍了检察院直接受理侦查案件由上一级检察院审查逮捕的法理依据,分析了职务犯罪案件决定逮捕权上提一级后将面临的问题,提出了克服问题的措施建议。 相似文献
103.
An extreme ultraviolet spectrometer has been developed for spectroscopic studies of highly charged ions with an electron beam ion trap. It has a slit-less configuration with a spherical varied-line-spacing grating that provides a flat focal plane for grazing incidence light. Alternative use of two different gratings enables us to cover the wavelength range 1-25 nm. Test observations with the Tokyo electron beam ion trap demonstrate the high performance of the present spectrometer such as a resolving power of above 1000. 相似文献
104.
Experimental study on hysteresis phenomena of shock wave structure in an over-expanded axisymmetric jet 总被引:1,自引:0,他引:1
Shigeru Matsuo Toshiaki Setoguchi Junji Nagao Miah Md. Ashraful Alam Heuy Dong Kim 《Journal of Mechanical Science and Technology》2011,25(10):2559-2565
In recent studies on two-dimensional supersonic jets, it is reported that the hysteresis phenomenon for the reflection type of shock waves in the jet flow field is occurred under the quasi-steady flow condition and this phenomenon is affected by the transitional pressure ratio between the regular reflection and Mach reflection. However, so far, there are few researches on the hysteresis phenomenon for the transition of shock waves between regular and Mach reflection in over-expanded supersonic jets and the phenomenon has not been investigated satisfactorily. Therefore, the purpose of this study is to clarify the hysteresis phenomena for the reflection type of shock wave in the over-expanded axi-symmetric supersonic jet experimentally, and to discuss the relationship between hysteresis phenomenon and rate of the change of pressure ratio with time. Furthermore, the effect of Mach number at the nozzle exit on hysteresis loop was investigated for two kinds of nozzle. 相似文献
105.
采用正交试验法完成了HSS/Co-M35含钴高速钢丝锥加工Ti-6Al-4V钛合金的攻丝试验。利用极差分析法研究了丝锥全生命周期参数即丝锥前角(刀具设计参数)、刃口钝化半径(刀具制造参数)、主轴转速(刀具使用参数)对攻丝性能的影响。利用综合评分法将扭矩max、轴向切削力max和切削温度max等3项攻丝性能指标转化为单一综合切削性能指标y*i,分析结果表明:攻钛合金时丝锥全生命周期参数取刃口钝化半径0.01 mm,丝锥前角10°,主轴转速150 r/min时最优。通过试验与数值模拟获得的扭矩值及趋势、切屑形态及切削刃对比图,验证了在Advant Edge FEM软件中建立的丝锥攻Ti-6Al-4V钛合金模型的可靠性。 相似文献
106.
Main‐chain smectic liquid crystalline polymer exhibiting unusually high thermal conductivity in an isotropic composite 下载免费PDF全文
Shusuke Yoshihara Masatoshi Tokita Toshiaki Ezaki Mitsuru Nakamura Masashi Sakaguchi Kazuaki Matsumoto Junji Watanabe 《应用聚合物科学杂志》2014,131(6)
The thermal conductivity (TC) of an isotropic composite comprising of a main‐chain smectic liquid crystalline PB‐10 polyester and 50‐μm‐sized roughly spherical magnesium oxide (MgO) particles is investigated. The increase in the composite TC with higher MgO fractions is steeper than that expected by Bruggeman's theory for the TC of a polydomain PB‐10 polyester (0.52 W m?1 K?1). When the filler content is larger than 30 vol %, the composite TC approaches a value that can be explained only if the polyester functions as a matrix with 1.0 W m?1 K?1, which is five times as high as those of isotropic common polymers (0.2 W m?1 K?1). Such an unusually high TC for a polymer matrix is attributed to some polymer lamellae that lie parallel to the particle surface and are stacked toward neighboring particles, thus creating effective heat paths between the particles and a continuous thermal network in a composite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39896. 相似文献
107.
The reforming of CH4 with CO2 over supported Rh catalysts has been studied over a range of temperatures (550–1000 K). A significant effect of the support on the catalytic activity was observed, where the order was Rh/Al2O3>Rh/TiO2>Rh/SiO2. The catalytic activity of Rh/SiO2 was promoted markedly by physical mixing of Rh/SiO2 with metal oxides such as Al2O3, TiO2, and MgO, indicating a synergetic effect. The role of the metal oxides used as the support and the physical mixture may be ascribed to the promotion in dissociation of CO2 on the surface of Rh, since the CH4 + CO2 reaction is first order in the pressure of CO2, suggesting that CO2 dissociation is the rate-determining step. The possible model of the synergetic effect was proposed. 相似文献
108.
Summary
Poly(phenylene oxide) (PPO) — aromatic polyester multiblock copolymers were synthesized by polycondensation of bisphenol-A
/ isophthalic acid or m- and p-hydroxybenzoic acids in the presence of PPO having a carboxylic acid at one end and a phenolic hydroxy group at the other
using triphenylphosphine / hexachloroethane as coupling agent. TG analysis showed that the multiblock copolymer showed relatively
high thermal stability.
Received: 5 January 1998/Accepted: 4 February 1998 相似文献
109.
Based on the equilibrium configuration paths, this study investigates the postbuckling behaviour, including the shape recovery capability, of stainless steel (SUS304) columns after a complete loading-unloading cycle. Experiments were conducted and later numerical simulation was carried out in order to analyze the observed buckling and postbuckling behaviour. Large deflection analysis is necessary for slender columns. Moreover, comparison of the experimental critical load with analytical predictions verifies the fact that physical nonlinearity should be taken into account to analyze the column’s buckling behaviour comprehensively. Thus, based on large deflection theory as well as the nonlinear stress-strain relations, the load-deformation curves of the columns during a complete loading-unloading cycle have been predicted by using the finite element modelling (FEM) code ANSYS.Precise and quantitative analyses of the results verify the fact that the material’s stress-strain properties, both in tension and compression, attribute to the column’s buckling behaviour. 相似文献
110.
Outstanding Toughness of Cherry Bark Achieved by Helical Spring Structure of Rigid Cellulose Fiber Combined with Flexible Layers of Lipid Polymers 下载免费PDF全文
Kayoko Kobayashi Yoko Ura Satoshi Kimura Junji Sugiyama 《Advanced materials (Deerfield Beach, Fla.)》2018,30(6)
Cellulose, a main component of cell walls, generally makes materials hard and brittle. However, an ultratough, cellulosic material is found in nature: cherry bark. Surprisingly, it elongates by more than twice of its initial length and behaves as a plastic film during stretching. This amazing mechanical property is achieved by a well‐designed cell wall structure; cellulose fibers are folded like helical springs, covered by multiple flexible layers of lipid polymers. 相似文献