Scheduling with safety distances

We investigate the problem of Scheduling with Safety Distances (SSD) that consists in scheduling jobs on two parallel machines without machine idle time. Every job is already assigned to its machine, and we just have to specify an ordering of the jobs for each machine. The goal is to find orderings of the jobs such that the minimum time elapsed between any two job completion times is maximized. We prove that this problem is NP-hard in general and give polynomial time algorithms for special cases. These results combined establish a sharp borderline between NP-complete and polynomial solvable versions of the problem SSD.This research was supported by the Christian Doppler Laboratorium für Diskrete Optimierung.On leave from the Mathematics Section, Forestry University Nanjing, Nanjing, PR China.     

A simple proof of the inequalityR M (MF(κ))≤1.2 + (1/2κ)

We consider the well-known problem of schedulingn independent tasks nonpreemptively onm identical processors with the objective of minimizing the makespan. Coffman, Garey and Johnson described an algorithm MULTIFIT, based on bin-packing, with a worst case performance better than the LPT-algorithm. The bound 1.22 obtained by them was claimed by Friesen in 1984 that it can be improved to 1.2. In this paper we give a simple proof for this bound.This work was done when the author was visiting the Technische Universität Graz, and this project is supported by the National Natural Science Foundation of China.This work was partially supported by the Austrian Fonds zur Förderung der wissenschaftlichen Forschung, Project S 32/01.On leave from the Mathematics Section, Nanjing Forestry University, Nanjing 200028, China     

The role of RGO in TiO<Subscript>2</Subscript>–RGO composites for the transesterification of dimethyl carbonate with phenol to diphenyl carbonate

TiO₂–RGO composites were prepared and used as efficient heterogeneous catalysts for the transesterification of dimethyl carbonate with phenol. Transmission electron microscopy images demonstrated that the RGO could remarkablely improve the dispersion of TiO₂. X‐ray photoelectron spectroscopy showed that RGO could change the chemical states of Ti species. Py-IR and Py-TPD results indicated the addition of RGO led to the increase of medium Lewis acid sites of TiO₂, which are positive for the transesterification reaction. The TiO₂–RGO composite with 50 wt% RGO exhibited a remarkable catalytic performance for the transesterification of dimethyl carbonate with phenol to diphenyl carbonate. Under the optimized conditions, the 53.5% phenol conversion and 99.9% transesterification selectivity were achieved. This phonel conversion of 53.5% could be compared with the result of homogeneous catalysts. RGO has been an excellent structural and electronic promoter in TiO₂–RGO composites.     

Analysis of the constituents in rat plasma after oral administration of Shexiang Baoxin pill by HPLC‐ESI‐MS/MS

A valid method using liquid chromatography coupled with electrospray ionization (ESI) and ion trap mass spectrometry was established for the study of the absorbed components in rat plasma after oral administration of a traditional Chinese medicine (TCM) Shexiang Baoxin pill. The plasma was deproteinated by adding methanol prior to liquid chromatography, in which separation was carried out on a Symmetry C₁₈ column (5 µm, 250 × 4.6 mm). A linear gradient with 0.5% formic acid–water–acetonitrile was used as mobile phase. Mass spectra were acquired in both negative and positive modes. Twenty‐one components including 17 components from Shexiang Baoxin pill and four metabolites were observed from a comprehensive analysis of the chromatography of Shexiang Baoxin pill, controlled plasma and dosed plasma. All of the 17 prototype compounds and three of the metabolites were identified by comparing their retention behaviors and MS and MS/MS spectra with reference compounds and literature data. This study developed an integrated method for screening the bioactive constituents in plasma after oral adminstration of Chinese herbal medicine and provided helpful chemical information for further pharmacology and active mechanism research on TCM. Copyright © 2009 John Wiley & Sons, Ltd.     

Effects of hydrogen bubbles on deformation of zinc anodes at high depth of discharge

Journal of Solid State Electrochemistry - The effects of hydrogen evolution reaction on the deformation of zinc anode which cycles at nearly 100% depth of discharge (DOD) are studied. Results show...     

The effectiveness of borneol on pharmacokinetics changes of four ginsenosides in Shexiang Baoxin Pill in vivo

Shexiang Baoxin Pill (SBP) is a traditional Chinese medicine, widely used for cardiovascular diseases in the clinic. Ginsenosides are important effective components in SBP, but their pharmacokinetic characteristics are still not known. In this paper, we studied the pharmacokinetics of ginsenoside Rb1, Rc, Re and Rg1 in SBP and investigated the effect of borneol on the pharmacokinetic characteristic of ginsenosides based on an Agilent G6410A triple quadrupole LC/MS system. Results showed that the pharmacokinetic parameters of ginsenoside Rb1, Rc, Re and Rg1 in rat plasma after oral administration of SBP are significantly different with oral administration of SBP without Borneolum Syntheticum. Plasma pharmacokinetic profiles after oral administration of ginsenoside Rb1, Rc, Re, Rg1 and co‐administration with borneol at three different ratios (10:1, 1:1 and 1:10 ginsenoside vs borneol, w/w) were also determined. It was demonstrated that borneol can elevate the plasma concentration of ginsenosides after co‐admininstration. Copyright © 2013 John Wiley & Sons, Ltd.     

基于高性能负载型钼基载氮体的化学链合成氨性能研究

化学链合成氨是一种新型的、环境友好的低压合成氨技术, 其借助于载氮体的传递作用实现固氮与释氮制氨的循环, 已受到产学界的广泛关注. 构建高效、绿色的载氮体是化学链合成氨技术的关键. 本工作通过一步热解法制备了负载型钼基载氮体, 并对其释氮、固氮及稳定性进行了研究. 结果表明: 在释氮阶段, 当热解制备温度为450 ℃时, 钼基载氮体的氢化产氨速率为最大, 可达20000 μmol•g^-1•h^-1; 固氮过程中, 氢气的引入加快了钼基载氮体从氮气中补充晶格氮的速率, 实现了载氮体的高效再生; 历经12次循环后, 负载型钼基载氮体(制备温度为600 ℃)的产氨速率基本稳定在1500 μmol•g^-1•h^-1. 本研究探索了负载型钼基载氮体化学链合成氨的可行性, 结果可为新型过渡金属基载氮体的开发及其化学链合成氨研究提供理论基础.     

锌在不同植物种苗中的吸收效应分析

为探讨植物种苗对水体中锌的吸收效应,采用实验室内培养方法,选择了玉米等7种作物种苗为受试品种,研究了不同植物对锌的吸收。结果表明,除棉花外,各类作物在5 d内可使水体中锌含量明显降低,黑芝麻、玉米、水稻植物幼苗的根中分别积累了高达19.8、18.8、15.9mg.g1,地上部茎叶中积累了8.2、10.1、7.1 mg.g1的锌。提出选择具有"超量积累倾向"的作物种苗进行环境水体中锌污染的植物修复。