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991.
A new application of the polymeric ionic liquid (PIL) in capillary electrophoresis is reported. Poly(1-vinyl-3-butylimidazolium bromide) was physically adsorbed on silica capillary as the simple and effective coating for capillary electrophoresis (CE) analysis, in which the PIL is not present in the background electrolyte. The electroosmotic flow (EOF) of the PIL-coated capillary as compared with that of the bare fused-silica capillary shows a different dependence on electrolyte pH values. The EOF is reversed over a wide pH range from 3.0 to 9.0 and shows good repeatability. It is also found that the coated capillary has a good tolerance to some organic solvents, 0.1 M NaOH and 0.1 M HCl. The PIL-coated capillary has been employed in different areas. Both the basic proteins and anionic analytes can be well separated by PIL-coated capillaries in a fast and easy way. The PIL-coated capillary is also able to separate organic acid additives in a grape juice. The results showed that this type of coating provides an alternative to the CE separation of anions and basic proteins.  相似文献   
992.
A hybrid system containing a pillar[5]arene unit and ten crown ether moieties was developed. The LCST behavior and thermo-responsiveness were successfully introduced into this pillar[5]arene-crown ether system. Both host-guest interactions and salting-out effect displayed great effects in realizing the supramolecular control over LCST properties and thermo-responsiveness. Compared with the individual macrocycles, this hybrid macrocycle system dramatically amplified the supramolecular control effect over LCST behavior.  相似文献   
993.
The enantio-discrimination of beta-chiral primary ammonium ions is achieved by a rational approach that utilizes three-center (bifurcated) hydrogen bonding. The extraction experiments on various selected guests reveal that the bifurcated H-bonding plays a crucial role for the chiral discrimination. The X-ray data obtained for an inclusion complex substantiate such interactions. Using the bifurcated H-bonding, the chiral molecular recognition with our C(3)-symmetric tripodal oxazoline receptors is extended generally toward ammonium ions of alpha-, beta-, and alpha,beta-chiral amines. Simple molecular models, evoking the bifurcated H-bonding, explain the chiral discrimination modes.  相似文献   
994.
用选择照射方法研究了N-甲基异靛蓝(isoindigatin)在(CD_3)_2CO、CDCl_3、DMSO-d_6溶剂中及重水交换后的~1H NMR谱。得到了化学环境极为类似的两芳环质子在不同溶剂中的NMR谱线归属和偶合常数。  相似文献   
995.
刘昊  韩德来  张彤  崔一平 《光学学报》2004,24(4):56-459
交叉波导是集成光学中的一种重要的器件单元,针对大角度交叉波导的结构及折射率分布,运用基于广义道格拉斯算子的宽角多步有限差分光束传播法模拟大角度交叉波导的传输特性,数值计算出波导中的光场的分布。与Crank-Nicholson格式的有限差分光束传播法相比,该算法在几乎不增加计算时间和计算机内存资源的情况下,结合了广义道格拉斯格式的有限差分光束传播法截断误差小[只有o(△x)^4]和宽角多步法所具有较高精度的优点,是光波导器件理想的数值模拟工具。在此基础上计算分析了大角度交叉波导的输出分支波导的能量与交叉角度的关系,以及交叉角度对波导间能量耦合的影响。这为实际的设计制作光器件的工作提供了极好的基础。  相似文献   
996.
For the problem of estimating the normal mean based on a random sample X 1,...,X n when a prior value 0 is available, a class of shrinkage estimators % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-qqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xHapdbiqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaubeaeqaje% aWbaGaamOBaaWcbeqdbaGafqiVd0MbaKaaaaGccaqGGaGaaiikaiaa% dUgacaGGPaGaeyypa0Jaam4AaiaacIcadaqfqaqabKqaahaacaqGUb% aaleqaneaacaqGubaaaOGaaiykaiaabccadaqfqaqabKqaahaacaWG% UbaaleqaneaaceqGybGbaebaaaGccaqGGaGaey4kaSIaaeiiaiaacI% cacaaIXaGaaeiiaiabgkHiTiaabccacaWGRbGaaiikamaavababeqc% baCaaiaab6gaaSqab0qaaiaabsfaaaGccaGGPaGaaiykamaavababe% qcbaCaaiaad6gaaSqab0qaaiabeY7aTbaaaaa!5615!\[\mathop {\hat \mu }\nolimits_n {\rm{ }}(k) = k(\mathop {\rm{T}}\nolimits_{\rm{n}} ){\rm{ }}\mathop {{\rm{\bar X}}}\nolimits_n {\rm{ }} + {\rm{ }}(1{\rm{ }} - {\rm{ }}k(\mathop {\rm{T}}\nolimits_{\rm{n}} ))\mathop \mu \nolimits_n \] is considered, where % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-qqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xHapdbiqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaubeaeqaje% aWbaGaamOBaaWcbeqcdawaaiaadsfaaaGccaqGGaGaaeypaiaabcca% caWGUbWaaWbaaSqabeaacaaIXaGaai4laiaaikdaaaGccaGGOaWaa0% aaaeaacaWGybaaamaaBaaajeaWbaGaamOBaaWcbeaakiaabccacqGH% sislcaqGGaWaaubeaeqajeaWbaGaaGimaaWcbeqdbaGaaeiVdaaaki% aacMcacaqGGaGaae4laiabeccaGiabeo8aZbaa!4C33!\[\mathop T\nolimits_n {\rm{ = }}n^{1/2} (\overline X _n {\rm{ }} - {\rm{ }}\mathop {\rm{\mu }}\nolimits_0 ){\rm{ /}} \sigma \] and k is a weight function. For certain choices of k, % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-qqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xHapdbiqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaubeaeqaje% aWbaGaamOBaaWcbeqdbaGafqiVd0MbaKaaaaGccaqGGaGaaiikaiaa% dUgacaGGPaaaaa!3CEE!\[\mathop {\hat \mu }\nolimits_n {\rm{ }}(k)\] coincides with previously studied preliminary test and shrinkage estimators. We consider choosing k from a natural non-parametric family of weight functions so as to minimize average risk relative to a specified prior p. We study how, by varying p, the MSE efficiency (relative to \-X) properties of % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-qqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xHapdbiqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaubeaeqaje% aWbaGaamOBaaWcbeqdbaGafqiVd0MbaKaaaaGccaqGGaGaaiikaiaa% dUgacaGGPaaaaa!3CEE!\[\mathop {\hat \mu }\nolimits_n {\rm{ }}(k)\] can be controlled. In the process, a certain robustness property of the usual family of posterior mean estimators, corresponding to the conjugate normal priors, is observed.  相似文献   
997.
对Jacobi椭圆函数展开法进行了扩展,且利用这一方法求出了Zakharov方程组的一系列新的精确周期解,在极限情况下可得到相应的孤波解,补充了前面研究的结果. 关键词: Jacobi椭圆函数展开法 非线性发展方程 精确解 周期解  相似文献   
998.
Dijkstra算法的一个改进   总被引:2,自引:1,他引:2  
韩伟一  王铮 《运筹与管理》2004,13(6):6-10,85
本文得到了一种Dijkstra算法的改进算法,如果最短路问题具有n个点和m条边,那么改进算法把问题的计算复杂性从原来的O(nlogn m)降低为O(nlogn M)(M≤m)。  相似文献   
999.
不同压电分流电路对声子晶体梁带隙的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
通过在匀质基体梁上周期性对贴连有分流电路的压电片,可以形成一维声子晶体结构.不同分流电路将决定梁的带隙特性.电阻分流电路能够对梁的模态共振有一定的抑制作用,而且可以通过改变压电效应的强弱使Bragg带隙结构发生变化.LC分流电路会使梁产生局域共振带隙,其带隙是由压电片激励LC电路产生电磁振荡形成.引入电阻后会使LC电路的共振作用变弱,使得带隙衰减幅值变小,但可以扩宽带隙频率范围.  相似文献   
1000.
Circulators play a significant role in radar and microwave communication systems.This paper proposes a broadband and highly efficient plasmonic circulator,which consists of spoof surface plasmon polaritons(SSPPs)waveguides and ferrite disks to support non-reciprocal mode coupling.The simulated performance of symmetrically designed circulator shows that it has an insertion loss of roughly 0.5 dB while the isolation and return loss is more than 12 dB in the frequency range of 6.0 GHz–10.0 GHz(relative bandwidth of 50%).Equivalent circuit model has been proposed to explain the operating mechanism of the plasmonic circulator.The equivalent circuit model,numerical simulations,and experimental results are consistent with each other,which demonstrates the good performance of the proposed plasmonic circulator.  相似文献   
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