水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

气化给煤系统故障分析

气化给煤装置自投运以来,出现了气化煤仓堵煤、称重给煤机输送皮带因跑偏而损伤以及清扫装置故障频繁等问题,多次造成气化系统减负荷运行。通过对出现的各种问题进行分析,找到了产生这些问题的原因,并有针对性地采用配煤和改进清扫链等措施,使出现的问题得到了极大的改善。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

A Review of Contemporary Views of Theories of Adhesion

The once distinct and independent theories of adhesion have been losing their isolation and converging. Ideas of the effects of surface roughness, once dismissed as irrelevant except in the case of textiles, have been revised; albeit on a smaller scale as details of surfaces have been revealed by sophisticated techniques. Electrostatic interactions across an interface have been more deeply explored and their significance recognised and expounded. Diffusion of groupings and chain segments within a polymer have been related to the possibilities of interaction with a variety of surfaces. Perhaps most important, theories of adsorption have been extended in depth. The precise nature of the molecular interactions have been recognised and quantified. In doing this the contribution of diffusion and elastoplastic phenomena have been integrated. These developments are collated and analysed to present the present understanding of the concepts.     

Stability of granules of solid solutions of poly-pehnyleneterephthalamide

Conclusions Studies of starting solutions of PPTA in sulfuric acid and of granules obtained under pressrue at low temperature, and of granules stored in a hermetic package, have been carried out by the methods of differential thermal analysis, turbidity spectrum and viscometry.On granulation of a solidified PPTA solution, short-term storage of the granules in a hermetic package, or short contanct of the granulated mass with air, no appreciable change in melting point or of the intrinsic viscosity of the system takes place.Long storage of a granulated solution, even in hermetic packages, can lead to a considerable decrease in the melting point of the crystal solvates, caused by an increase in defectiveness of crystal structure under the effect of moisture.Translated from Khimicheskie Volokna, No. 3, pp. 25–26, May–June, 1986.     

醋酸纤维素取代基分布与性质的关系

分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。     

熟石膏陈化过程的研究进展

探讨了熟石膏陈化过程中无水石膏（AⅢ-CaSO₄）与水蒸气的反应机理以及二水石膏（CaSO₄·2H₂O）的脱水机理。首先介绍了熟石膏陈化过程的基本原理,然后讲解了熟石膏陈化过程中水蒸气在AⅢ-CaSO₄上的物理吸附与化学吸附,其后描述了熟石膏陈化过程中CaSO₄·2H₂O晶体的脱水行为与脱水动力学,最后提到了CaSO₄·2H₂O、CaSO₄·0.5H₂O、AⅢ-CaSO₄的晶体结构。     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

平板硫化机横梁受热变形及热板中高度的应用

介绍了平板硫化机热板中高度在硫化排气过程中的作用及其实现途径和评价方法;提出了设置热板中高度时应遵守的＂刚性横梁、柔性热板＂概念和＂最短路径、最小排气阻力＂原则;探讨了横梁热变形对热板中高度的影响。结果表明,参考横梁热变形设置的热板中高度有助于解决平板硫化机在复杂状态下硫化制品时的表面排气问题。     

Determination of the extent of oxidation of fats

Summary The amount of secondary oxidation products in refined and unrefined fats has been determined by reaction with benzidine acetate in iso-octane absolute alcohol solution, and measurement of the absorption at 350 mμ of the yellow color has been made. An “aldehyde value” has been calculated from this absorption intensity, using cinnamaldehyde as a reference substance. Determination of the aldehyde value and peroxide number of oils before and during refining has given information on the effect of the different refining processes on the state of oxidation of the oils. The effect of hardening on the content of oxidation products of an oil has been investigated. The effect of the amount of oxidation products in the unrefined material on the flavor stability of the refined material and of the margarine made from it has also been studied.     

A study of miscibility of blends of polybutadienes of varying microstructure

The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure.     

Decomposition of the technology of creation of commodity portfolio of a textile enterprise

In economics and management, classical single-factor study of an object is being pursued increasingly rarely. The results of multifactor studies can be presented explicitly in the form of scales and matrices of various dimensions. This article provides a classification of the technologies of creation of commodity portfolio of an enterprise in the form of two- and three-dimensional taxonomic (classification) space. Squares of matrices correspond to objects and methods of creation of a variety of products manufactured by the enterprise. Substantive, procedural, and innovation levels of the hierarchy of the technology of commodity portfolio creation are considered as the classification criteria.     

金黄色葡萄球菌滤液中凝固酶组分分析

目的对金黄色葡萄球菌滤液制剂中凝固酶进行纯化,并对其性质及作用进行分析。方法用分子筛层析等方法纯化凝固酶,用HPLC、光谱等方法对其进行纯度和性质分析。用双向免疫扩散试验和T淋巴细胞增殖试验检测其生物学特性。结果经纯化的凝固酶纯度达97%以上,相对分子质量约为350000,含17种氨基酸,主要紫外吸收峰出现在260nm左右,α-螺旋含量占27.3%,组分中含糖约18.1%,T淋巴细胞增殖试验和双向免疫扩散法证明纯化的凝固酶具有生物学活性。结论金黄色葡萄球菌滤液中凝固酶为一类糖与蛋白复合物,具有抗原活性,可能在金黄色葡萄球菌滤液的功效中发挥作用。     

邢钢套筒窑换热器内漏生产实践

介绍了套筒窑换热器的工作原理、作用及邢钢套筒窑换热器内漏的判断依据,对套筒窑换热器内漏的原因进行了简要的分析,对内漏前后的主要参数进行了对比,同时结合实际生产情况,制定了行之有效的控制措施,收到了良好的效果。     

Confirmation of identity of aflatoxins

Aflatoxins are detected and determined by analytical procedures based on physical and chemical properties, e.g., ultraviolet absorbance, fluorescence, solubility and Chromatographie retention times during thin layer (TLC) or liquid chromatography. For acceptance of analytical results based on these properties, especially for regulatory purposes, proof of identity of the compound being measured is essential. Numerous tests have been devised for confirmation of identity. Included are tests based on toxicological effects observed in the duckling, zebrafish, chick embryo,Bacillus megaterium and many other species; chemical tests based on formation of derivatives such as the acetates and water adducts; and tests based on color changes of TLC spots after contact with spray reagents, e.g., sulfuric acid. All of the foregoing have inherent uncertainties in interpretation of identity. On the other hand, mass spectrometry (MS) is one of the most specific methods of identification available; however, it has been difficult to apply at the low concentrations at which aflatoxins are routinely detected. In this paper, the confirmation techniques for aflatoxins are placed in historical perspective and are reviewed and evaluated A recently developed procedure for the application of negative ionization MS for the confirmation of identity of aflatoxins in foods or feeds at concentrations as low as 10 ng/g is described. This procedure consists of isolation of the aflatoxin by Association of Official Analytical Chemists’ methods, purification by preparatory 2-dimensional TLC, in situ elution of the aflatoxin TLC spot and analysis of the sample by negative ion chemical ionization MS using a direct insertion probe.     

对库伦法测定石油产品氯含量探讨

文章对采用氧化微库仑法进行石油和石油产品的氯含量进行了探讨,介绍了ECS3000氯分析仪在测定石油及石油产品氯含量的应用。为库仑测氯仪的正确使用和故障排除提供了参考资料。通过多年来的实践证明,采用库仑法测定石油及石油产品氯含量是科学和有效的,为生产、科研使用提供了可靠数据。     

我国聚丙烯工业国际竞争力分析

应用管理学和市场营销学的基本原理和方法,深入分析我国聚丙烯工业的内部和外部环境、市场状况以及加入WTO后所面临的机遇与挑战.在此基础上,应用SWTO(态势分析法),确认出主要的优势和劣势、机会和威胁,对我国聚丙烯工业的国际竞争力进行结构化的综合分析.     

德士古煤气化工艺运行方式总结

在全面总结德士古气化炉试运行经验的基础上,进行了优化煤种配比和降低气化操作温度等新尝试。经过一段时间的摸索和考察,肯定了高、低灰熔点煤种的混配可降低入炉煤的灰熔点,保证气流床熔融排渣气化工艺的稳定运行;在低于煤灰熔融温度下进行气化并实施固态排渣工艺是可行和有效的,经十余年的运行,其经济效益明显。