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991.
Authors Index
Author Index to Volume 121 相似文献992.
Ji‐Cai Fan Zhi‐Cai Shang Jun Liang Xiu‐Hong Liu Yang Liu 《Journal of Physical Organic Chemistry》2008,21(11):945-953
Oxidation of aliphatic and aromatic alcohols has been studied by using N‐bromosuccinimide (NBS) as oxidant and polyethylene glycol (PEG) as reaction medium under mild reaction conditions. Temperature and solvent effect are studied. Theoretical study is also done with the Gaussian 98 suite of program and the calculation results are in good accordance with the experimental outcome. This system offers a very clean, convenient, environmentally benign method for the oxidation of alcohols. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
993.
Implementing remote controlled-NOT gates and entanglement swapping via geometric phase gates in ion-trap systems
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We propose a scheme for the implementation of remote controlled-NOT gates and entanglement swapping via geometric phase gates in ion-trap systems. The proposed scheme uses the two ground states of the A-type ions as memory instead of the vibrational mode. And the system is robust against the spontaneous radiation and the dephasing. 相似文献
994.
光束漂移的莫尔条纹检测原理 总被引:1,自引:0,他引:1
针对大气湍流光束漂移,设计了一套使用莫尔条纹进行检测的系统,该系统具有检测微小长度和角度的特点,它是将光束漂移的微小角度借助条纹的方式进行放大。分析大气湍流条件下可能获得的最大条纹宽度,然后将条纹宽度和现有较好的CCD分辨率作比较。在CCD分辨率不足的情况下,采用莫尔条纹细分技术,通过适当的电路,将条纹的光信号转换成电信号,使相位变化转换为脉宽的变化,并在形成的方波中内插高频脉冲,通过测量脉冲数目可进一步实现高倍率细分,从而达到较高的分辨率,理论上系统的检测精度可达到0.025μrad。 相似文献
995.
B. Wang T. Zhou Z. L. Xiu B. J. Kim 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,60(1):89-95
We numerically investigate how to enhance
synchronizability of coupled identical oscillators in complex
networks with research focus on the roles of the high level of
clustering for a given heterogeneity in the degree distribution.
By using the edge-exchange method with the fixed degree sequence, we
first directly maximize synchronizability measured by the
eigenratio of the coupling matrix, through the use of the so-called
memory tabu search algorithm developed in applied mathematics. The
resulting optimal network, which turns out to be weakly
disassortative, is observed to exhibit a small modularity. More
importantly, it is clearly revealed that the optimally
synchronizable network for a given degree sequence shows a very low
level of clustering, containing much fewer small-size loops than the
original network. We then use the clustering coefficient as an
object function to be reduced during the edge exchanges, and find it
a very efficient way to enhance synchronizability. We thus
conclude that under the condition of a given degree heterogeneity,
the clustering plays a very important role in the network synchronization. 相似文献
996.
Rong-Can Yang Xiu Lin Zhi-Ping Huang Hong Xie Jian-Feng Lin Gui-Ru Huang 《Optics Communications》2007,279(2):399-402
We propose a simple protocol for the generation of W states and the implementation of phase-covariant cloning and anticloning machines via adiabatic passage in ion-trap system. In the present scheme, the system state evolves in the dark space during the whole procedure. We only use the two-level ions to act as memory and do not require the transfer quantum information from ions to the vibrational mode, which makes the system simple and robust against decoherence. Moreover, the proposal may be feasible based on current technologies. 相似文献
997.
This paper develops convergence theory of the gradient projection method by Calamai and Moré (Math. Programming, vol. 39, 93–116, 1987) which, for minimizing a continuously differentiable optimization problem min{f(x) : x } where is a nonempty closed convex set, generates a sequence xk+1 = P(xk – k f(xk)) where the stepsize k > 0 is chosen suitably. It is shown that, when f(x) is a pseudo-convex (quasi-convex) function, this method has strong convergence results: either xk x* and x* is a minimizer (stationary point); or xk arg min{f(x) : x } = , and f(xk) inf{f(x) : x }. 相似文献
998.
液体晃动等效力学模型的参数识别 总被引:2,自引:0,他引:2
本文研究确定贮箱内液体晃动等效力学模型的参数的试验方法。通过对充液贮箱试验系统的简化分析得到系统的传递函数表达式,应用频响函数拟合方法得到了模型参数,在曲线拟合过程中利用权函数解决液体晃动的非线性影响因素。应用本文所述方法研究了某型号卫星推进剂贮箱的液体晃动问题。 相似文献
999.
Derivations and Automorphisms of the Positive Part of the Two-parameter Quantum Group Ur,s(B3)
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We compute the derivations of the positive part of the two-parameter quantum group U_(r,s)(B_3) and show that the Hochschild cohomology group of degree 1 of this algebra is a threedimensional vector space over the base field C. We also compute the groups of(Hopf) algebra automorphisms of the augmented two-parameter quantized enveloping algebra ?_(r,s)~(≥0)(B_3). 相似文献
1000.
高阶紧致格式求解二维粘性不可压缩复杂流场 总被引:3,自引:0,他引:3
提出了一种求解二维不可压缩复杂流场的高精度算法.控制方程为原始变量、压力Poisson方程提法.在任意曲线坐标下,采用四阶紧致格式求解Navier-Stokes方程组,时间推进采用交替方向隐式(ADI)格式,在非交错网格上用松弛法求解压力Poisson方程.对于复杂的流场,采用了区域分解方法,并在每一时间步对各子域实施松弛迭代使之能精确地反映非定常流场.利用该算法计算了二维受驱空腔流动,弯管流动和垂直平板的突然起动问题.计算结果与实验结果和其他研究者的计算结果相比较吻合良好.对于平板起动流动,成功地模拟了流场中旋涡的生成以及Karman涡街的形成 相似文献