Prediction of Chameleonic Efficiency

Chameleonic properties, i. e., the capacity of a molecule to hide polarity in non-polar environments and expose it in water, help achieving sufficient permeability and solubility for drug molecules with high MW. We present models of experimental measures of polarity for a set of 24 FDA approved drugs (MW 405-1113) and one PROTAC (MW 1034). Conformational ensembles in aqueous and non-polar environments were generated using molecular dynamics. A linear regression model that predicts chromatographic apparent polarity (EPSA) with a mean unsigned error of 10 Ų was derived based on separate terms for donor, acceptor, and total molecular SASA. A good correlation (R²=0.92) with an experimental measure of hydrogen bond donor potential, Δlog P_oct-tol, was found for the mean hydrogen bond donor SASA of the conformational ensemble scaled with Abraham's A hydrogen bond acidity. Two quantitative measures of chameleonic behaviour, the chameleonic efficiency indices, are introduced. We envision that the methods presented herein will be useful to triage designed molecules and prioritize those with the best chance of achieving acceptable permeability and solubility.     

On the linear correlation between microhardness and mechanical properties in polar polymers and blends

The tensile elastic modulus (E), yield stress (σ_Y) and microhardness (MH) of neat and binary and ternary blends of glassy semicrystalline ethylene–vinyl alcohol copolymer (EVOH), a glassy amorphous polyamide and a semicrystalline nylon‐containing ionomer covering a broad range of properties were examined. The tests were carried out on dry and water‐equilibrated samples to produce stiffer and softer materials, respectively. From the results, more accurate linear correlations were found to describe adequately the microhardness, modulus and yield stress of these strongly self‐associated polymers through hydrogen bonding. Copyright © 2003 Society of Chemical Industry     

Computerized IR Determination of Structural Group Composition for High-Boiling Oil Fractions

A computerized form is given of IR spectral determination for structural group composition in high-boiling oil fractions by Berthold's method (7 structural elements) and Kuklinskii's method (28 structural elements), which reduces the analysis time by factors of 3–4 and improves the accuracy.     

山区长输气管线的曲线测设

该文介绍了在山区长输气管线测量中 ,管线的折点桩之间大部分不通视且部分点上空有障碍物 ,采用GPS不能施测坐标时 ,结合山区的自然地理条件 ,采用全站仪间接施测折点水平角 ,极坐标法测设曲线以及跨越障碍物测设曲线的内容和方法 ,可在一定精度要求下应用     

Oleuropein Inhibits LDL Oxidation Induced by Cooking Oil Frying By-products and Platelet Aggregation Induced by Platelet-Activating Factor

Oleuropein, a polyphenolic glucoside, constituent of olive fruit and oil, has been previously shown to exhibit, in vitro, potent properties as a biological antioxidant. In the present paper, two new properties are demonstrated in vitro as well, concerning its vascular protection activity, against the atheromatic lesion formation and its blood antithrombotic effect. Firstly, it was found that the oxidation of low-density lipoproteins (LDL), induced by different quantities of total polar materials (TPM), was inhibited by 10 μ M (final concentration) of oleuropein, revealing approx. 50% protection. Secondly, platelet-rich human plasma aggregation, induced by either the platelet-activating factor or adenosine diphospate or arachidonic acid, was inhibited by oleuropein. The 10 μ M (final concentration) of oleuropein was proven to be the most effective among the tested concentrations against LDL oxidation, while an IC₅₀=0.41 mM was calculated for its inhibitory activity against platelet aggregation induced by 0.7 μ M platelet-activating factor.     

Analysis of polar compound classes in SRC-II liquids: Comparison of non-aqueous titrametric,i.r. spectrometric and h.p.l.c. methods

Results for various types of polar compounds in SRC-11 coal-derived liquids and other fuels were obtained by one or more of the three analytical methods: non-aqueous titration, i.r. spectroscopy and h.p.l.c. Practical aspects as well as precision, accuracy and assumptions necessary for effective application of each of the methods are discussed. H.p.l.c. is applicable to the widest variety of compound types, is the most rapid, most sensitive and shows the best promise for increased development and improvement. Application and development of these techniques is a logical step toward improving process monitoring, catalyst development, toxicological screening and general fuel analysis.     

南京老虎山黄土-古土壤剖面不同粒级组分的磁化率及其古气候意义

利用沉降离心法将老虎山黄土-古土壤的酸不溶相分离成<2μm、2～45μm和>45μm三个粒级组分,并分别测定了这些组分和全岩的磁化率。结果表明,无论是全岩,还是三个不同粒级组分,它们的磁化率都可以单独作为长江中下游地区古气候演变的参考指标。其中,<2μm粒级的质量磁化率明显大于全岩和2～45μm、>45μm两粒级,而且其分辨率也明显高于2～45μm和>45μm这两个粒级组分。本实验结果还显示,虽然<2μum的质量磁化率最大,但对全岩质量磁化率的贡献率与2～45μm粒级相当,>45μm粒级的贡献率较低。     

DT型粉状炸药专用蜡的研制

以多种含蜡馏分为基础原料，添加适量DT复合添加剂研制的DT型粉状炸药专用蜡具有优异的分散性和抗水性，可满足各种低梯粉状炸药要求，简化炸药配方，方便操作及其质量控制，以其生产的炸药爆速高，贮存期长，各项性能满足GB12437－2000标准要求。     

氟化活性炭纤维对极性分子的吸附

将活性炭纤维（ACF）与氟气反应制备出氟化活性炭纤维（FACF），根据将FACF与参照试样XPS的对比，碳原子是以sp^3杂化轨道同氟原子形成共健键。αs图分析氮吸附等温线的线果表明，ACF氟化后其比表面积和微孔容积都显著降低，微孔宽度基本不变，ACF的水吸附等温线呈V型，而FACF对水的吸附量极小；FACF的微孔表面具有完美的憎水性和高稳定性，乙醇和甲醇在ACF上的吸附等温线是Ⅰ型，在FACF上接近于Ⅰ型，但吸附量显著降低。     

主轴回转精度测试中的多圈数据采集及处理

本文就主轴回转精度测试中的多圈数据采集和处理方法作了探讨。根据提出的方法和改进后的测试系统编制了实用程序,进行了实测,获得了测试结果。