手性配位交换色谱法拆分普卢利沙星对映体

以L-异亮氨酸和CuSO4作为手性流动相添加剂,采用手性配位交换色谱法拆分普卢利沙星对映体.考察了添加剂的种类、浓度、比例以及流动相pH等因素对拆分的影响.优化的色谱条件为:C18色谱柱,流动相为8 mmol/L L-异亮氨酸和4 mmol/L CuSO4溶液(pH=3.5)-甲醇(68∶32,V/V),流速为1.0 ...     

比值-导数荧光法测定藤茶中的蛇葡萄素

以10 g/L AlCl3溶液为络合剂,在λex=442 nm,λem=503、505、507 nm下,建立比值-一阶导数荧光分析法测定藤茶中的蛇葡萄素.蛇葡萄素质量浓度在l0.08～151.2μg/mL范围内与比值导数光谱的峰谷差值呈良好的线性关系(r=0.9979),平均回收率为97.35%,(RSD=2.3%,n=9).经配对t检验法分析,与HPLC法的测定结果无显著差异.该法可用于藤茶提取过程中质量控制的检测方法.     

Kuhn-Tucker鞍点等价定理的推广

考虑如下单目标数学规划问题minf(劝,g(二)(0.lzeeL 、,Z F /‘、其中二任E.,g间是仍维向量函数. 作相应于(r)的Lagrange函数L(二,动一f(劝+。勺(劝.若有一个点挤,动,玉〔刀气云〔刃‘,云>o,使 L(玉,动《L(玉,司《L(二,动对一切二任E”,。〔刃份,二)0成立,则称俩,动为L(二,叻的一个鞍点. H.w.Knhn and A.W.Tu业er在文章[1〕中首次证明了著名的鞍点等价定理(简称K刃等价定理): K--T等价定理设f闭和功(劝(了~1,2,…,二)是凸函数,而且g(劝满足约束资格.那么,历是(p)的最优解的充分必要条件是:存在云>o,使任,动是L(二,动的鞍点. 文章[2…     

间接光度法测定水和废水中硫酸盐

在稀盐酸介质中定量加入铬酸钡悬浮液使与SO2-4反应生成BaSO4沉淀。经煮沸,并调节溶液的酸度后,将含有沉淀的溶液以1500r·min-1的速率离心1min,在420nm波长处用1cm吸收皿,以水作参比测定上层澄清液中CrO2-4的吸光度。硫酸根浓度在0～6mg/50ml范围内符合比耳定律。检出限为0.48μg·ml-1,RSD(n=8)为5.38%(SO2-40.50mg)和1.03%(SO2-42 00mg)。平均回收率为99.5%,方法已应用于雨水、地面水及废水中硫酸根的测定。     

面向智能电网的EPON解决方案

通信接入是坚强智能电网通信支撑的关键,而EPON能实现高宽带与新业务现代网络信息的发展需求,适用于电网的通信建设。在研究了EPON技术的原理以及相对于其他通信技术的优势的基础上提出了利用EPON设备实现电网智能抄表、电网智能营销所、配电自动化、电力智能大厦、电力智能小区的方案,具有适应性和可行性,配合保护策略构建统一坚强智能绿色电网。     

多目标规划中Kuhn-Tucker条件的充分性的推广

本文在更一般的凸性条件下,讨论了多目标规划中Kuhn—Tucker条件的充分性。特别指出了:对于等式约束函数不必像通常那样假定为线性的,在证明方法上也不必像通常那样依赖于单目标规划来处理。     

多目标凸规划的自身对偶性

<正> §1 前言在单目标数学规划的对偶理论中,建立了各种各样的对偶型,其中有一重要者是自身对偶型。所谓一个单目标规划是自身对偶的,是指它和它的对偶规划是等价的。亦即,它可以从它的对偶规划中增加或减去某些约束条件而得到,而且它和它的对偶规划有相同的最优解和相同的最     

多目标非线性规划的对偶理论

<正> §1前言在单目标数学规划的对偶理论中,我们知道,两个规划问题称为是对偶的,如果它们满足:(1)其中一个是最小问题,另一个是最大问题;(2)如果其中一个规划问题存在最优解,那么另一个规划问题也存在最优解,而且两个规划问题的最优值相等;(3)如果两个规划问题同时存在可行解,     

Effect of disorder on exciton dissociation in conjugated polymers

By using a multi-configurational time-dependent Hartree–Fock(MCTDHF) method for the time-dependent Schr ?dinger equation and a Newtonian equation of motion for lattice, we investigate the disorder effects on the dissociation process of excitons in conjugated polymer chains. The simulations are performed within the framework of an extended version of the Su–Schrieffer–Heeger model modified to include on-site disorder, off-diagonal, electron–electron interaction, and an external electric field. Our results show that Coulomb correlation effects play an important role in determining the exciton dissociation process. The electric field required to dissociate an exciton can practically impossibly occur in a pure polymer chain, especially in the case of triplet exciton. However, when the on-site disorder effects are taken into account, this leads to a reduction in mean dissociation electric fields. As the disorder strength increases, the dissociation field decreases effectively. On the contrary, the effects of off-diagonal disorder are negative in most cases. Moreover, the dependence of exciton dissociation on the conjugated length is also discussed.     

Ground-state phase diagram of the dimerizedspin-1/2 two-leg ladder

Dimerized spin-1/2 ladders exhibit a variety of phase structures, which depend on the intra-chain and inter-chain spin exchange energies as well as on the dimerization pattern of the ladder. Using the density matrix renormalization group (DMRG) algorithm, we study critical properties of the bond-alternating two-leg Heisenberg spin ladder with diagonal interaction J_×. Two types of spin systems, staggered dimerized antiferromagnetic ladder and columnar dimerized ferro-antiferromagnetic couplings ladder, are investigated. To clarify the phase transition behaviors, we simultaneously analyze the string order parameter (SOP), the twisted order parameter (TOP), as well as a measurement of the quantum information analysis. Based on measuring this different observables, we establish the phase diagram accurately and give the fitting functions of the phase boundaries. In addition, the phase transition of cross-coupled spin ladder (in the absence of intrinsic dimerization) is also discussed.