Optimization of conditions for high temprature capillarary gas chromatography using a split-mode programmable temprature vaporizing injection system

This paper discribes an investigation into the effects of various operating conditions applied in a PTV-based gas chromatographic system on the performance observed in high temperature analyses. The work comprises a combination of physical and chromatographic measurements, and conclusions are drawn as to the most effective way of using the equipment under evaluation.     

MAC protocol with delay-aware adaptive round time for split light-trail

Light-trail (LT) has been considered as an attractive solution for optical networks to support emerging services such as video-on-demand, pseudo-wires, and data-centers. The media access control (MAC) protocol is essential for LT networks because LT is a shared-medium. Recently, in order to enhance the throughput, a regular LT can be split into several sub-LTs at the split nodes where traffic undergoes optical-electronic-optical conversation. To deal with the split LT, a novel MAC protocol named Delay-aware adaptive round time for split LT (DAARTS) is developed on the basis of DAART MAC protocol and the schemes of splitting LT. To estimate the performance of the developed MAC protocol, ART, DAART and DAARTS protocols are simulated and compared in the scenarios of three different traffic patterns. Simulation results show that, for traffic 1 and traffic 2, DAARTS has stable throughput performance and can obtain almost 40.83% and 106.64% throughput improvement compared with DAART, respectively. In other words, DAARTS can further enhance the throughput of LT networks.     

北京奥运前期典型天气拉曼激光雷达观测研究

以自行研制的双波长三通道拉曼激光雷达、振荡天平（PM10、PM2.5）、碳黑（BC）气溶胶分析仪及能见度仪相结合对“好运北京”2008年奥运会前期典型天气状况进行了测量与分析,给出了北京奥运主场馆上空气溶胶消光系数的垂直分布及其时空变化关系,计算了气溶胶的消光散射比,并分析了灰霾天气条件下大气能见度、气溶胶颗粒物PM10、PM2.5、BC及气溶胶消光系数垂直分布之间的相互关系。研究结果表明,灰霾天气条件下,大气能见度、颗粒物质量浓度与气溶胶颗粒物消光系数之间具有直接的相关性。     

General alternative regularization methods for split equality common fixed-point problem

The purpose of this paper is to propose a general alternative regularization algorithm for split equality common fixed-point problem of nonexpansive operator in the framework of infinite-dimensional Hilbert spaces. We prove the strong convergence of the proposed algorithm with the stepsizes chosen by two ways. As a consequence, we obtain strong convergence theorems for split equality common fixed-point problem of firmly-nonexpansive operator and split equality problem. The efficiency of the proposed algorithms is illustrated by some numerical tests.     

An analytical bound on the fleet size in vehicle routing problems: A dynamic programming approach

We present an analytical upper bound on the number of required vehicles for vehicle routing problems with split deliveries and any number of capacitated depots. We show that a fleet size greater than the proposed bound is not achievable based on a set of common assumptions. This property of the upper bound is proved through a dynamic programming approach. We also discuss the validity of the bound for a wide variety of routing problems with or without split deliveries.     

基于时延估计的分裂阵时域波束形成技术

大孔径拖曳线列阵受舰艇横向机动、洋流影响和水动力影响时会产生一定的阵形畸变,阵形畸变使得波束形成时阵列流型失配,进而降低了目标方位分辨率和阵处理的增益。在无法进行阵形估计时,基于时延估计的分裂阵时域波束形成技术将大孔径拖曳线阵分为左右两个子阵分别做波束形成,通过加权广义相关时延估计算法估算对应波束的时延差,再依据估算时延差对左右两个波束进行延时求和得到最终的波束信号。仿真和海试数据证明,相对于全阵直接做波束形成的方法,基于时延估计的分裂阵的时域波束形成技术有效提高了目标方位分辨率和阵处理的增益。     

Effects of finite pulse width on two-dimensional Fourier transform electron spin resonance

Two-dimensional (2D) Fourier transform ESR techniques, such as 2D-ELDOR, have considerably improved the resolution of ESR in studies of molecular dynamics in complex fluids such as liquid crystals and membrane vesicles and in spin labeled polymers and peptides. A well-developed theory based on the stochastic Liouville equation (SLE) has been successfully employed to analyze these experiments. However, one fundamental assumption has been utilized to simplify the complex analysis, viz. the pulses have been treated as ideal non-selective ones, which therefore provide uniform irradiation of the whole spectrum. In actual experiments, the pulses are of finite width causing deviations from the theoretical predictions, a problem that is exacerbated by experiments performed at higher frequencies. In the present paper we provide a method to deal with the full SLE including the explicit role of the molecular dynamics, the spin Hamiltonian and the radiation field during the pulse. The computations are rendered more manageable by utilizing the Trotter formula, which is adapted to handle this SLE in what we call a "Split Super-Operator" method. Examples are given for different motional regimes, which show how 2D-ELDOR spectra are affected by the finite pulse widths. The theory shows good agreement with 2D-ELDOR experiments performed as a function of pulse width.     

非线性Schrönger方程的算法和光学孤子相互作用的数值结果

本文首先指出了算法分裂步骤(split step)Fourier法和光束传播(Pmpagating beam)法的等价性。利用这种算法,我们数字地摸拟了:1、可变等振幅孤子脉冲对在无耗光纤中的传输过程,证明提高振幅可使孤子的相互作用大大减小;2、初始等间隔的一阶孤子脉冲序列在无耗光纤中的传输过程,发现它完全不同于两个孤子脉冲的传输。     

双因素裂区试验主区双向区组的设计与分析

本文给出了双因素裂区试验主区双向区组的设计与分析。这种设计在主区的两个方向上均采用随机区组设计或在主区的一个方向上采用随机区组设计，而在另一个方向上采用平衡不完全区组设计，用较少试验小区来控制主区两个方向上环境差异，减少主区的试验误差。     

Selective and non-selective sampling from precolumn separations—with emphasis on the sampling of aqueous solutions

Various methods of gas chromatographic analysis at high resolution and low detection limits in aqueous solutions are described with regard to sampling techniques, column technology, and the application of coupled pre-columns, also including multidimensional methods. Immobilized polyethylene glycol (Carbowax 20 M) columns have also been produced and used successfully.