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961.
Xin Cheng LI Gui Ling NING* Liang Ping WU Ji Hong SHAN Yuan LIN School of Chemical Engineering Dalian University of Technology Dalian Chemistry Department East China Normal University Shanghai 《中国化学快报》2002,13(12)
The activation of carbon-carbon bonds by soluble transitional metal complexes has been one of the most prominent challenges in recent years1-3. Despite the inertness of carbon-carbon bonds, some possible ways to cleave carbon-carbon bonds have been devised, such as relieving ring energy4, inducing aromatic stabilization5, forming stable metallocyclic complexes6, etc. Silver salts, such as silver perchlorate and silver trifluoroacetate, play an important role in carbon-carbon bond activation,… 相似文献
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963.
The ionization process in the collisions of He^2+ with C^q+ (q = 0-5) is investigated by using the continuum-distorted-wave eikonal-initial-state approximation. Double-differential cross sections for 1s and 2s sub-shells are obtained at the electron-ejected angle θ = 0° with the projectile energy ranging from 30keV/u to 10MeV/u. Variation of ionization mechanisms with q in C^q+ is studied, and the dependences on the projectile energies and target sub-shells are also discussed. It is found that in the whole energy range, the absolute values of soft collision (SC) and binary encounter (BE) peaks decrease with increasing q. For the lower incident energies, the electron capture to the projectile continuum (ECC) peak decrease with increasing q as well as SC and BE peaks. For the higher incident energies (〉 1 MeV/u), the absolute value of ECC peak increases with increasing q, so that the crossings of cross sections appear for C^q+ with different q. This can be explained by the matching of velocities between the projectile and the electron initially bound to the target. 相似文献
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966.
通过对半导体材料中载流子迁移率的特性分析,在原HPM探测器的基础上,提出了探测器中半导体传感器的新设计,使探测器的检测灵敏度提高一个量级;同时研制成功S波段HPM探测器。在传感器的加工方面采用了新的工艺,并对电源进行了改进,使之功能完善、使用简单、具有实用性。其电源偏压在40V时,X波段的探测器在60kW时输出检测脉冲信号幅度高达9V,S波段的探测器在600kW时输出检测脉冲信号幅度高达10V,可适用于10~500ns脉宽的HPM功率测量。 相似文献
967.
Based on the hydrodynamic shell-on-shell collision model, the Z-pinch processes of nested tungsten wire-array in Sino-Russian joint experiments on Angara-5-1 facility are simulated by means of our one-dimensional three-temperature radiation magneto-hydrodynamic code. The results show the evolutions of x-ray radiation burst, implosion trajectories of interfaces, current transfer in inner and outer wire-array plasmas, and the temporal and spatial changes of magnetic field and current density in the process. About 20% of the total driven current is transferred into the inner wire-array plasma by convection and diffusion of magnetic field when the two shells are pinched closest. Compared to the measured x-ray power, the simulated full width at half maximum and time at the strongest radiation agree approximately with the measured values. It is also demonstrated in our simulation that the radiation of nested wire-array Z-pinch is enhanced. The effects of fluctuations of driven current on yields of x-ray are also investigated. 相似文献
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970.
Nisin Z的工业生产中利用细胞菌体吸附Nisin Z,离心后的发酵上清液(Nisin Z效价1000IU/m L左右)则通常被当成废液处理。本文建立大孔吸附树脂富集浓缩,丙酮-盐双水相脱色及中压制备型高效液相色谱精制三步法,从低浓度的发酵液上清液中回收较高纯度Nisin Z的方法。经过HZM-3树脂吸附和解吸,乳链菌肽Z的纯度由0.28%提高了95倍至26.65%,双水相脱色后Nisin Z纯度进一步提高至55.43%,经过制备分离后Nisin Z纯度达到94.12%。总回收率为71.39%,脱色率为95.7%。 相似文献