常用化学化工互联网数据库简介

化合物各种常见性质的检索对化学化工工作者十分重要。介绍了几个重要的化学化工互联网数据库,包括Chemfinder,NCI,SRC,ZINC,ChemBlink五个数据库,并对其站点、内容和功能以及使用技巧作了简要的阐述。     

Internet上免费化学化工资源检索

介绍了Internet上免费化学化工资源的导航系统、免费化学数据库、免费化学化工软件、免费化学化工期刊及可免费查询的世界各国专利。     

网上化学信息检索

随着网络技术和化学学科的发展,利用网络进行化学信息检索已经成为每位化学工作者必须掌握的最重要的检索手段。本文介绍利用网络进行化学信息检索的手段,对常规化学信息、常用中英文数据库、标准图谱数据库以及文献求助等方法分别进行了介绍。     

开发农用化学品的新方法

新技术的使用改变了传统寻找新的农用化学品品种的途径,组合化学、高通量筛选(HTS)和基因技术作为创新手段被广泛应用。虽然目前我们还无法证明它们的优点,但是,随着时间的推移,这些新技术将会创造出巨大的经济和社会效益。     

磁性微球在天然药物化学中的应用进展

伴随化工合成与材料学的飞速发展,磁性微球这种新型材料与天然药物化学之间的学科交叉已经逐渐深入,磁性微球成功解决了部分以往依靠传统技术手段在天然药物化学研究中无法攻克的困难。它所应用的范围现已贯穿药物开发,成分分析,质量标准和制剂工艺等重要环节。本文主要围绕其在提取分离、活性筛选、化学分析和药物制剂4个方面的应用与进展进行综述,为相关研究提供参考依据。     

组合化学在多相催化领域中的应用

本文系统综述了新近兴起的技术——组合化学在多相催化领域中的研究进展。通过对组合催化研究的两个关键因素催化剂库合成及催化剂高通量筛选技术的评价分析认为,在对已有的催化体系和催化剂优化的同时，如何高效研制新催化材料及开发新筛选检测技术，是组合催化研究的主导思想，对此的深刻理解和运用，将增强实验室的创新能力。     

新型催化技术——组合催化

介绍了组合催化技术的基本原理及研究方法,对高速筛选技术及组合催化技术的应用情况进行了综述,并展望了组合催化技术发展方向和趋势。     

组合催化的原理、策略与发展

介绍了组合催化的基本原理和催化剂库的高通量筛选方法;讨论了组合催化技术的2个关键因素———催化剂库的合成方法和相应的高通量检测技术在催化研究中的重要作用。综述了组合催化技术在无机、有机以及生物催化领域中的应用进展,指出进一步与计算机相结合,研究新的催化剂体系、开发新的催化剂合成技术和新的筛选技术是今后组合催化的发展方向和趋势。     

Internet化学专利数据库使用技巧

本文主要介绍了因特网上化学专利概况 ,对网上专利的查询方式、一些国内外优秀的专利搜索工具进行了较为系统的整理和综合 ,使广大化学工作者熟悉有关专利检索数据库、特别是因特网上的专利检索与查询技巧 ,希望能有助于化学工作者及时了解化学最新专利情报和信息。     

Symyx与陶氏公司和BP联合开发催化剂

Symyx技术公司和陶氏化学公司采用高通量筛选技术,新开发出一系列烯烃聚合用单活性点催化剂。该催化剂为酰胺-醚为基础的铪催化剂。Symyx与陶氏公司从1999年1月以来一直联合采用高通量筛选技术开发聚烯烃催化剂,并且陶氏公司正在开发Symyx公司在合作中发现的几种催化剂。采用传统的催化剂开发方法,发现一种催化剂需要约一年,采用高通量筛选技术则只需数天。     

微生物源硝基还原酶催化反应的研究

在建立的微生物源硝基还原酶筛选模型上,从众多微生物菌株中筛选诱变到一株细菌134-13,其培养液能将对-(N-苯基甲酰基)邻硝基苯甲醚转化成对-(N-苯基甲酰基)邻氨基苯甲醚,在优化的培养基上培养22 h,底物的转化率可达89.4%.     

压力曲筛筛面的化学清洗

淀粉行业应用压力曲筛，取得良好的经济效益和社会效益。但多数中小型淀粉厂对筛面的清洗束手无策。文章较详细地阐述曲筛筛面的清洗方法——化学清洗，化学清洗曲筛筛面既清洗了筛面，又不腐蚀筛面。化学清洗是曲筛筛面清洗的一种行之有效而简便实用的方法。     

Efficient Screening of Target-Specific Selected Compounds in Mixtures by 19F NMR Binding Assay with Predicted 19F NMR Chemical Shifts

Ligand-based ¹⁹F NMR screening is a highly effective and well-established hit-finding approach. The high sensitivity to protein binding makes it particularly suitable for fragment screening. Different criteria can be considered for generating fluorinated fragment libraries. One common strategy is to assemble a large, diverse, well-designed and characterized fragment library which is screened in mixtures, generated based on experimental ¹⁹F NMR chemical shifts. Here, we introduce a complementary knowledge-based ¹⁹F NMR screening approach, named ¹⁹Focused screening, enabling the efficient screening of putative active molecules selected by computational hit finding methodologies, in mixtures assembled and on-the-fly deconvoluted based on predicted ¹⁹F NMR chemical shifts. In this study, we developed a novel approach, named LEFshift, for ¹⁹F NMR chemical shift prediction using rooted topological fluorine torsion fingerprints in combination with a random forest machine learning method. A demonstration of this approach to a real test case is reported.     

利用筛分装置提高磷矿石品位的研究

本文通过试验比较了筛分前后磷矿石的品位及筛下矿石份额,发现筛分装置的筛分间距对筛分结果有很大影响,因此可以通过选择合适的筛分间距来提高磷矿品位,达到化工厂生产对磷矿石品位的要求.     

Derivation of performance equations for solid-solid screens

Equations relating efficiency of separation to reject loss of desirable material have been derived for solid-solid screens. The derivations were based on the relative passage of particles through individual screen plate apertures and the extent of mixing on the feed side of the screen plate. Two limiting cases of mixing were considered: plug flow and mixed flow along the screen plate. Both barrier and probability screening were included in the analysis. The physical significance of the terms in the equations and the implications of their derivation were described in relation to wood pulp screening.     

Development of a data‐driven fuzzy screening model for enhanced oil recovery methods using an adaptive weighting system

Screening of enhanced oil recovery (EOR) methods is a main prerequisite for EOR planning and design. In this study, an integrated data‐driven screening model (DDSM) is developed to improve EOR screening using the combined capabilities of the fuzzy expert approach (FEA) and support vector regression (SVR) techniques. In this study, EOR field data from the past 40 years were reviewed to generate an updated and reliable EOR criteria table as a basis to construct a fuzzy screening model. The DDSM was evaluated to determine the quantitative screening and ranking of EOR methods using seven field datasets, including the fast forecasting of the nominated EOR methods. In order to improve screening performance, a fuzzy model was integrated using 4 SVR models to predict the adaptive weights of the screening parameter for decision making. The SVR models can predict the recovery factor (RF) of EOR methods including gas, chemical, steam, and combustion to calculate the adaptive effective weight of the screening parameters. The SVR models were trained with datasets generated from simulations of the EOR process. The absolute average error (AAE) of the SVR models from the simulation varied within the range of 0.078–0.095 for the prediction of the RF. The DDSM results were compatible to the data published in other literature. In addition, the developed model can provide comparable results to common screening software. The results showed improvements due to the adaptive weighting system on the EOR methods’ screening for the studied reservoirs relative to the fuzzy engine with constant weights. The presented integrated model can guide the screening process to select the efficient EOR method in practical applications.     

Introduction of a generally applicable method to estimate retrieval of active molecules for similarity searching using fingerprints

Fingerprints are bit string representations of molecular structure and properties and are among the most widely used computational tools for similarity searching and database screening. Various fingerprint designs are available and their search performance is in general strongly dependent on the compound classes under study and the chemical characteristics of screening databases. Currently, it is not possible to predict the probability of identifying novel hits through fingerprint searching. However, for practical applications, such estimations would be very useful because one might be able, for example, to prioritize fingerprints and compound selection strategies or decide whether or not a similarity search campaign with subsequent experimental evaluation of candidate compounds would be promising at all. We have developed a method that makes it possible to predict the outcome of similarity search calculations using any type of keyed fingerprint. The methodology incorporates bit frequency distributions of reference molecules and the screening database into an information-theoretic function and determines the principally possible recall of active compounds within selection sets of varying size. We calibrate the function on diverse compound classes and accurately predict compound recovery in retrospective virtual screening trials. Furthermore, we correctly predict fingerprint search performance on two experimental high-throughput screening data sets (HTS). Our findings indicate that given a set of reference molecules, a fingerprint, and a screening database, we can readily estimate how likely it will be to retrieve active compounds, without knowledge about the distribution of potential hits in the database.     

大型抛射筛数学模型分析

通过抛射筛数学模型建立的因素分析，描述了在这建模过程中众多因素对透筛概率的影响，指出颗粒能否透筛是一个复杂的过程。颗粒透筛的几何概率仅反应颗粒与筛网接触一瞬间的透筛现象，在此之前还有其它因素对颗凿的运动产生影响。大型抛射筛数学模型的建立过程，考虑了颗粒在筛分过程中运动规律及透筛概率规律。     

A Novel Approach to the Discovery of Small-Molecule Ligands of CDK2

In an attempt to identify novel small-molecule ligands of cyclin-dependent kinase 2 (CDK2) with potential as allosteric inhibitors, we have devised a robust and cost-effective fluorescence-based high-throughput screening assay. The assay is based on the specific interaction of CDK2 with the extrinsic fluorophore 8-anilino-1-naphthalene sulfonate (ANS), which binds to a large allosteric pocket adjacent to the ATP site. Hit compounds that displace ANS directly or indirectly from CDK2 are readily classified as ATP site binders or allosteric ligands through the use of staurosporine, which blocks the ATP site without displacing ANS. Pilot screening of 1453 compounds led to the discovery of 12 compounds with displacement activities (EC(50) values) ranging from 6 to 44 μM, all of which were classified as ATP-site-directed ligands. Four new type I inhibitor scaffolds were confirmed by X-ray crystallography. Although this small compound library contained only ATP-site-directed ligands, the application of this assay to large compound libraries has the potential to reveal previously unrecognized chemical scaffolds suitable for structure-based design of CDK2 inhibitors with new mechanisms of action.     

超声波振动筛在三氯蔗糖生产中的应用

超声波振动筛是超声波技术与振动筛分技术的有机结合,它可以由普通筛分进行简单的加超声波系统改造而成,利用超声波振动筛进行三氯蔗糖的筛分,能够减少筛分过程的粉尘污染及产品消耗,能够大幅提高筛分效率,节约成本,能够消除或降低筛分过程的静电吸附问题、避免或减少筛网堵塞问题,能够有效提高筛分精度。