苯并三唑和8-羟基喹啉对铜的缓蚀协同作用

通过电化学极化曲线和电化学阻抗谱研究了苯并三唑（BTA）和8 羟基喹啉（HQ）对铜的缓蚀协同作用， BTA和HQ复配使用后提高了电极的膜电阻，降低了电极的膜电容，增强了对铜腐蚀的抑制作用.通过MM2分子力学程序和PPP SCF量子化学方法优化计算了BTA和HQ的分子结构参数，分析讨论了它们之间的缓蚀协同效应.     

The effect of magnetic field on the stability of (18-crown-6) complexes with potassium ion

Macrocyclic polyethers are ligands with selectivity for metal ions. In order to understand the interactions between ligand, ion and solvent we resorting to study of magnetic field effect on ion-macrocyclic complexes. Therefore, we studied the complexation between 18-crown-6 and potassium ion in water through the conductometry technique (in 25+0.05 °C) by a nonlinear least-square program (Genplot) under magnetic field.We observed that stability constants of complexes in the presence of the magnetic field, were decreased. Like-wise, we observed that, magnetic field influenced on ion, solvent and ligand one by one.     

MORMIN: A quasi-Newtonian energy minimizer fitting the nuclear overhauser data

In this article, we describe the program MORMIN, which can simultaneously minimize the mechanical energy of a given macromolecular structure, together with a weighted quadratic penalty function of the difference between the observed and computed nuclear Overhauser effect (nOe) peaks. The gradient of the nOe penalty function relatively to the proton coordinates is computed from an exact closed formula of a matrix exponential derivative. To cut CPU time, the molecular system is partitioned into nonoverlapping subsets containing the protons involved in the observed peaks. The algorithm is no longer exact, but if a 1% relative error is accepted it can be run, on a scalar computer, in about the same CPU time as needed for the calculation of the mechanical energy. We have successfully run the program in more than 1000 situations, including cases where the hybrid method failed because of the occurrence of negative eigenvalues. In some cases, the optimization of the Cartesian coordinates could be successfully extended to individual atomic diffusion times. © 1993 John Wiley & Sons, Inc.     

Das Monte Carlo-studium der binären copolymerisation in der annahme des vorletzten Effektes. I. Theorie,MEMORY 5-programm,anwendungen

This paper presents a mathematical model (using the Monte Carlo technique) for the building of a binary copolymer considering the penultimate effect. One discusses the algorithm and the computer implementation. Finally, two applications are given. The purpose of this series of papers is to provide a Monte Carlo method to compute the sequence distribution for the hypothesis of penultimate effect (program MEMORY 5), ultimate effect (program MEMORY 3), and copolymerization with depolymerization (program MEMORY 6).     

STUDIES ON THE SEQUENCE STRUCTURE OF TPA/EG/PHB LIQUID CRYSTALLINE COPOLYESTERS

In this paper, the sequence structure of TPA/EG/PHB liquid crystalline copolyesters made from different synthetic methods has been studied by ~1H-NMR with the help of computer program of processing peaks. The results showed that the ether bonds were not observed in TPA./EG/PHB copolyesters and the synthetic process had a great effect on their sequence structure. Under certain conditions, the high,random TPA/EG/PHB copolyesters which were considered to have higher performances than PET/xPHB could be obtained.     

Dynamic response of shear induced structure solutions in permeable rock

Additives for improving the flow uniformity during secondary oil recovery are partially retained in the rock. The flow improval effects continue to be observed even when the chemical solution is succeeded by pure water. Considerable flushing with water is required before the old permeability of the rock is restored to its original higher level. This effect is extremely advantageous for the application to water flooding profiles in oil recovery. It makes possible an alternating water slug/chemical solution flooding program which further reduces the already relatively small amount of chemicals required in the operation.     

Characterizing the transmission properties of an ion funnel

The characteristic features of ion transmission properties in a radio-frequency (RF) electric-field driven ion funnel using the SIMION ion trajectory simulation package is presented. A user program applying the Douglas ion-neutral collisional drag coefficient model is incorporated to properly account for the ion focusing and transport effect of the background gas under the effect of the driving RF and a superimposed DC field. The simulated m/z transmission window compares favorably with the experimental results reported by Smith et al. RF amplitude and pressure dependence of experimentally observed m/z transmission windows are also examined, and an approximated effective potential model based on Gerlich's equation is proposed to interpret the low-m/z cutoff behavior. A modified ion funnel configuration is described.     

Calculation of chromatographic dead times and retention indices with the aid of a computer program in BASIC

A computer program is presented for calculating chromatographic dead time from the observed retention times of an homologous series of standards using the iterative approximation procedure of Guardino et al. The program is written in BASIC and is readily adaptable to most microcomputers capable of using BASIC. Corrected retention times and capacity factors of standards and of samples are also calculated by the program. Examples of applications in gas chromatography and reversed-phase high-pressure liquid chromatography are presented. A listing of the BASIC program is given.     

化学计量保证方案展望

介绍化学计量保证方案的概况、实施程序、作用和意义,展望了化学计量保证方案的前景。     

Bioinformatics Analysis of Oligosaccharide Phosphorylation Effect on the Stabilization of the β-Amylase Ligand Complex

Starch is the most abundant storage carbohydrate produced in plants. The beginning of transitory starch degradation in plants depends mainly on day cycle, posttranslational regulation of enzyme activity, and starch phosphorylation, but the molecular mechanism of these factors' influence is not yet precisely described. The aim of our analysis was to investigate the effect of phosphorylation on the intermolecular energies for stabilization of the complexes between the set of phosphorylated and nonphosphorylated carbohydrate ligands and Solanum tuberosum (L.) β-amylase model. For performing protein-ligand docking procedures and calculating the binding energies, the DOCK6 and Glide 4.5 program suites were applied. We have observed simultaneously the effect of chain elongation, phosphorylation, and chain branching. Results of flexible ligand docking show that phosphorylation as well as chain elongation increase the stabilization of the ligand-protein complex.     

三功能策略设计制备具有优异低温抗积碳性能的Ni-CeO2@SiO2催化剂催化甲烷干重整反应

随着全球人为温室气体排放量(主要是甲烷和二氧化碳)的增加,全球变暖的趋势逐渐增加,因此,迫切需要通过各种技术来捕获和利用这些温室气体.甲烷干气重整反应(DRM)可以有效地将甲烷和二氧化碳这两种资源丰富、价格低廉的温室气体转化为高附加值化学品,减少它们向大气排放.尽管DRM工艺的应用具有许多优势,但是反应期间碳沉积和活性组分的烧结是阻碍其工业应用的两个主要原因.这些碳沉积物可能覆盖活性中心或阻塞催化剂的孔道,从而导致催化剂活性降低.镍基催化剂因其价格低廉、初始活性高和资源丰富而得到广泛的应用.但应用于DRM反应的Ni基催化剂在反应中容易烧结和积碳,导致催化剂迅速失活.为解决上述问题,本文从三功能策略角度出发,即SiO2壳层的限域作用和Ni-Ce之间的协同作用以及CeO2的消除积碳作用,采用原位一锅法设计合成了一种限域型Ni-CeO2核壳结构催化剂(Ni-CeO2@SiO2).通过X射线衍射、透射电子显微镜、能量色散X射线光谱、N2吸附/脱附、氢气程序升温还原和脱附、氧气程序升温脱附、拉曼光谱、热重分析和原位漫反射红外傅里叶变换光谱测试对催化剂进行了系统的表征,来揭示催化剂的理化性质和反应机理.催化剂应用于甲烷干气重整反应结果表明,在温度区间为550～800℃时,与传统浸渍法合成的催化剂相比,Ni-CeO2@SiO2催化剂具有更高的活性.高温800℃下的稳定性测试结果显示,传统浸渍法合成的催化剂在反应20 h后就出现了大量的积碳且活性下降明显;而Ni-CeO2@SiO2催化剂在800℃下反应100 h后未检测到积碳,并且催化剂中的Ni纳米颗粒的平均粒径从5.01 nm仅增长到5.77 nm,表现出很好的高温抗积碳和耐烧结性能.值得注意的是,Ni-CeO2@SiO2催化剂在低温600℃(形成碳沉积的最可能温度区域)下反应20h后也未检测到积碳的形成,表现出催化剂良好的低温稳定性和抗积碳性能.这可能归因于对Ni-CeO2@SiO2催化剂的三功能作用,即多孔二氧化硅壳层的限域作用、Ni与CeO2之间强的金属-金属氧化物相互作用以及具有丰富活性氧物种CeO2的消除积碳的作用.通过原位漫反射红外傅里叶变换光谱测试来探究反应机理.结果 表明,DRM反应在Ni-CeO2@SiO2催化剂上遵循L-H机理,添加CeO2可以消除碳沉积并促进CO2活化.该三功能策略为设计其他应用于DRM的高性能催化剂提供了指导,有望加快该工艺的工业化.     

定量X-射线荧光光谱分析中用于计算理论α系数的计算机程序DRALPHA

在修改后的基本参数法程序NRLXRF基础上本文所研制的计算机程序DRALPHA可用于计算Lachance-Traill或Claisse-Quintin方程中的理论α系数以校正X-射线荧光定量分析中元素间的吸收-增强效应。     

Testing an alternative search algorithm for compound identification with the ‘Wiley Registry of Tandem Mass Spectral Data,MSforID’

A tandem mass spectral database system consists of a library of reference spectra and a search program. State‐of‐the‐art search programs show a high tolerance for variability in compound‐specific fragmentation patterns produced by collision‐induced decomposition and enable sensitive and specific ‘identity search’. In this communication, performance characteristics of two search algorithms combined with the ‘Wiley Registry of Tandem Mass Spectral Data, MSforID’ (Wiley Registry MSMS, John Wiley and Sons, Hoboken, NJ, USA) were evaluated. The search algorithms tested were the MSMS search algorithm implemented in the NIST MS Search program 2.0g (NIST, Gaithersburg, MD, USA) and the MSforID algorithm (John Wiley and Sons, Hoboken, NJ, USA). Sample spectra were acquired on different instruments and, thus, covered a broad range of possible experimental conditions or were generated in silico. For each algorithm, more than 30 000 matches were performed. Statistical evaluation of the library search results revealed that principally both search algorithms can be combined with the Wiley Registry MSMS to create a reliable identification tool. It appears, however, that a higher degree of spectral similarity is necessary to obtain a correct match with the NIST MS Search program. This characteristic of the NIST MS Search program has a positive effect on specificity as it helps to avoid false positive matches (type I errors), but reduces sensitivity. Thus, particularly with sample spectra acquired on instruments differing in their setup from tandem‐in‐space type fragmentation, a comparably higher number of false negative matches (type II errors) were observed by searching the Wiley Registry MSMS. Copyright © 2013 John Wiley & Sons, Ltd.     

ISOEFF98. A program for studies of isotope effects using Hessian modifications

A new program for calculations of isotope effects has been developed. It requires only force constants for substrate and transition state as the external data. All other calculational steps are integrated into the program. ISOEFF98 has features of Hessian modification and scale factor optimization. The first of these allows studies of isotope effect changes upon weakening or strengthening of internal coordinates. The second feature allows fitting of the calculated isotope effect to the experimental value by scaling of molecular frequencies. This revised version was published online in July 2006 with corrections to the Cover Date.     

T-Analyst: a program for efficient analysis of protein conformational changes by torsion angles

T-Analyst is a user-friendly computer program for analyzing trajectories from molecular modeling. Instead of using Cartesian coordinates for protein conformational analysis, T-Analyst is based on internal bond-angle-torsion coordinates in which internal torsion angle movements, such as side-chain rotations, can be easily detected. The program computes entropy and automatically detects and corrects angle periodicity to produce accurate rotameric states of dihedrals. It also clusters multiple conformations and detects dihedral rotations that contribute hinge-like motions. Correlated motions between selected dihedrals can also be observed from the correlation map. T-Analyst focuses on showing changes in protein flexibility between different states and selecting representative protein conformations for molecular docking studies. The program is provided with instructions and full source code in Perl.     

MoWeD, a computer program to rapidly deconvolute low resolution electrospray liquid chromatography/mass spectrometry runs to determine component molecular weights

A computer program is described that can rapidly process low-resolution electrospray liquid chromatography/mass spectrometry (LC/MS) for peptides and proteins and assign molecular weights for observed components. The program first analyzes individual scans using a deconvolution algorithm similar to that previously described by Zhang and Marshall. Results for the entire run are then sorted by mass and those values found in adjacent scans are grouped together. The list of found components can also be compared to a user defined list of target molecular weight values making it easy to compare the results from different analyses. The program also has the capability to process a rolling average of scans that improves the performance when analyzing high molecular weight components. Other program features facilitate closer examination of selected spectra or regions of the chromatogram to check the MoWeD mass assignments. The utility of the program was demonstrated by the analysis of LC/MS data derived from a complex mixture of proteins derived from a bacterial whole cell lysate that had previously been analyzed manually. The MoWeD analysis was 30 times faster and provided a more comprehensive list of the components present.     

微相分离及链结构对聚酯-聚醚嵌段共聚物分子运动的影响

本文首先研究了成型方法和热处理对聚对苯二甲酸乙二酯与聚氧四亚甲基嵌段共聚物动态力学温度谱的影响,结合应力-应变曲线讨论了微相分离与力学性能的关系。其次,比较了三种不同链结构的聚酯-聚醚嵌段共聚物在不同温控程序下的动态力学温度谱,讨论了链结构对软链段结晶的影响。最后观察了聚氨酯-聚醚嵌段共聚物双重玻璃化转变现象并作了解释。     

稀土元素在植物中的分异机制 (I) 小麦不同器官中的稀土元素分异模式及形成机制

以小麦为植物材料，利用外源稀土添加、营养液培养等人工控制手段，研究了稀土元素在植物体内的分异效应，并探讨了分异效应产生的机制。结果表明，稀土元素在小麦不同器官中出现显著分异。根系出现中稀土(MREE)富集特征和“M”型四重效应，分析是由稀土元素与PO4^3-的选择性沉淀造成。小麦地上部分稀土元素分布出现“W”型四重效应，分析也是由根部磷沉淀造成。与此同时，小麦茎部相对富集轻稀土(LREE)，叶中相对富集重稀土(HREE)。运用VMINTEQ程序计算了木质部溶液中稀土元素的结合形态主要有LnEDTA^-和Ln^3 (Ln指稀土元素)，但仅有LnEDTA^-表现出HREE相对富集特征，其他形态则表现出LREE相对富集特征。分析叶部LREE／HREE分异是吸收LnEDTA^-造成，而茎部LREE／HREE分异则是吸收Ln^3 和其他形态稀土的结果。细胞壁对Ln^3 的吸附也是导致以上分异特征的重要因素。