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 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.     

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     

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。     

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.     

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.     

Process of acceleration of filtration of viscose

Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969.     

Determination of oxirane content of derivatives of fats

Although oxirane functions react readily with a large variety of chemical reagents, no single analytical method has been universally successful in measuring the oxirane content of all epoxides. This failure is ascribable to the manner in which the chemical reactivity of the three membered cyclic ethers is modified by molecular structure and by the presence of nearby substituents. A survey of the various types of published analytical methods is given, but major emphasis is placed upon a discussion of procedures applicable to the analysis of epoxy derivatives of fats. Most of these latter methods depend upon the addition of some reagent, HX, to the epoxide ring with simultaneous cleavage of a carbon-oxygen bond. Utiliz. Res. Dev. Div., ARS, USDA.     

Interpretation of DSC measurements of the degree of fusion of rigid PVC

Differential scanning calorimetric (DSC) measurements can be used to infer the degree of fusion of rigid PVC articles. The preferred method involves annealing of the specimen at 260°C for 5 minutes, to erase all crystalline structures, followed by a 2 day storage at room temperature. New crystalline entities that are formed give use to an endotherm in the DSC heating mode. The magnitude of this endotherm divided by the total endotherm observed to 220°C can be used to estimate the degree of fusion of the specimen. Data from various processes and different cross-sections of extruded pipe are consistent with solvent resistance estimations.     

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。     

Quantitative measure of selectivity of hydrogenation of triglycerides

Graphs have been prepared using a digital computer that allow the quantitative determination of the degree of selectivity for the hydrogenation of cottonseed, peanut, corn, soybean and linseed oils. Use of these graphs requires only a knowledge of the composition of the initial (unhydrogenated) oil and that of the hydrogenated oil plus simple calculations. If the exact composition of the initial oil is unknown, a typical composition can generally be assumed.     

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）。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

Approximation of temperature dependence of the modulus of elasticity of glass

A refined nonlinear value of the main parameter of a material, i.e., the elongation modulus versus the instant temperature value, was suggested for introduction into the computational algorithm of tempering stresses.     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

光度法测定甲醛的研究进展

本文综述了近年来光度法测定甲醛的研究进展,分别从非动力学光度法、动力学光度法进行归纳,并从反应介质、检出限、线性范围和应用等方面进行叙述。     

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。     

Effect of Plastic Component of Defromation on Accuracy of Prediction of Functional Properties of Polymeric Materials

Fibre Chemistry - Classical methods for predicting polymeric materials deformation processes are based on numerical solution of governing Boltzmann-Volterra viscoelasticity type of equations, which...     

Computer-aided method of analysis of nanocomposite structure on the basis of calculations of isolines of fractal dimensionality

A computer-aided method of analysis of nanocomposite textures on the basis of calculation of the fractal dimensions of nanostructures using microphotographs of the nanocomposites is proposed. The computer-aided method of assessment of the fractal dimensions is notable for the use of an algorithm of calculation of the self-similarity indices of the power spectra of two-dimensional luminance fields of the nanostructure imaging on microphotographs and the use of the box-counting algorithm for measurement of the fractal dimensions. This method makes it possible to assess the rates and directions of cluster growth in the nanocomposite texture. On the basis of numerous computer experiments using the method proposed, we have ascertained that dark zones of two types are present on microphotographs of the texture of the nanocomposites obtained by sedimentation of tin oxides and formation of fine-particle silicon carbide: homogeneous zones, where there is no manifestation of the fine structure of the nanocomposites, and indistinctly contoured structured zones that hypothetically can correspond to the formation of new clusters or ensembles of nanoparticles.     

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。