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.     

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。     

KINEMATIC VISCOSITY-TEMPERATURE BEHAVIOR OF HEAVY TBP-FRACTIONS (455°C+) OF ARABIAN CRUDE OILS

A generalized kinematic viscosity-temperature correlation for undefined liquid heavy petroleum fractions has been developed to represent the data for a wide range of temperature from 100°C to 200°C. The correlation is based on the experimental kinematic viscosity data of true boiling point fractions of four Arabian crude oils. The characterization property required for estimation is 50% boiling point. The proposed correlation fits the experimental data with an overall absolute error of 6.1%. Experimental measurements of kinematic viscosity of heavy true boiling point fractions of Arabian crude oils were also obtained in order to develop the proposed correlation.     

Partial or total silylation of dextran with hexamethyldisilazane

The silylation reaction of dextran with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) in DMSO was studied as the first step of the synthesis of new amphiphilic polyester-grafted dextrans. According to the experimental conditions, i.e. dextran molar weight, medium temperature and reaction time, HMDS/OH ratio, addition of a catalyst and co-solvent, partially or totally silylated dextrans were recovered. The highest silylation yields were obtained with the lowest molecular weight dextrans. The increase in temperature medium and/or reaction time, the presence of catalyst or co-solvent favored the protection yield. Whatever the dextran used, complete silylation of the polysaccharide chain could be achieved by adequate selection of the experimental conditions. The thermal properties of resulting silylated polysaccharides were investigated by temperature modulated DSC. It was observed that T_g values of partially silylated dextran were maintained between 120 and 140 °C, independently of the dextran molecular weight. Interestingly, DMSO proved to behave as an efficient plasticizer of (partially) silylated dextrans. The partially silylated dextrans were efficiently used as multifunctional macroinitiators for the controlled ring-opening polymerization (ROP) of lactone. The ROP was then promoted from the remaining hydroxyl groups in the presence of tin or aluminium activator. After polymerization and ultimate deprotection of the silylated dextran backbone, amphiphilic polyester-grafted dextrans were readily recovered.     

Comparative study on adaptive rational macromodels of highly resonant structures

Two macromodeling techniques using rational bases are investigated to accurately predict the natural frequencies of highly resonant microwave structures. Three methods are proposed and compared to calculate pole‐free solutions to the Thiele continued fraction and vector fitting pole‐residue models of the characteristic equation det[Z(s)]. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

New correlation for predicting the viscosity of heavy petroleum fractions

A new, simple and reliable empirical correlation for predicting the viscosities of heavy petroleum fractions is proposed, applicable to fractions with mid-boiling points from 80 to 550°C over a wide range of viscosities (0.4 to 260 mm² s⁻¹) and measurement temperatures (40 to 200°C). This correlation showed better accuracy in the prediction of heavy petroleum fraction viscosities than that of the most accurate and much more complicated predictive methods in the literature, since it gave an overall average absolute deviation of 6.5% when tested on 296 data for medium and heavy petroleum fractions.     

改进的蒽酮法检测肺炎链球菌荚膜多糖结合物中多糖浓度

目的改进检测肺炎链球菌荚膜多糖结合物中多糖浓度的蒽酮法。方法分别对蒽酮法中蒽酮的浓度和处理温度进行优化,并对改进的方法进行验证和重复性检测。结果适宜的蒽酮浓度为0·3g/300ml,处理温度为40℃,在检测肺炎链球菌多糖结合物原液中的多糖浓度时,标准曲线回归系数高,方法稳定,重现性好。结论改进的蒽酮法可以有效、准确、稳定地检测肺炎链球菌结合物多糖原液中的多糖浓度。     

多糖类生物降解材料的研究进展

本文在参考二十八篇文献及专利报道的基础上详述了以多糖类天然高分子为原料的生物降解材料的研究发展。淀粉、纤维素、壳聚糖及其它多糖，是自然界中大量存在的天然高分子材料，来源丰富，价格低廉、且易被微生物分解。多糖类降解材料可用通用的加工方法和设备加工成型，产品性能优良，可完全生物降解，其开发和应用是解决目前世界范围内的塑料产生的污染问题的理想途径。