国产MB—86催化剂使用情况分析

抚顺引进的５００００ｔ／ｙ丙烯腈装置要改造到７００００ｔ／ｙ的生产能力，其中更换国产催化ＭＢ－８６是较为关键的一步，文章对此进行了总结与分析。     

聚丙烯酸丁酯-丙烯酸/苯乙烯辐射接枝共聚物粘接性能的研究

采用过氧化预辐射法将生产高分子特效膜残留下的废苯乙烯（Ｓｔ）与聚丙烯酸丁酯－丙烯酸（ＰＢＡ－ＡＡ）接枝，制得ＰＢＡ－ＡＡ／Ｓｔ接枝共聚物。比较了辐射法和化学法所制接枝共聚物的粘接性能，考察了Ｓｔ含量、丙烯酸丁酯（ＢＡ）／ＡＡ共聚物特性粘度、ＡＡ用量、ＢＡ和Ｓｔ预辐射剂量对接枝共聚物粘接性能的影响。结果表明，采用辐射法所制接枝共聚物的粘接性能优于化学法所制接枝共聚物的粘接性能；废Ｓｔ比纯Ｓｔ效果好；当Ｓｔ含量为３３％、ＢＡ／ＡＡ共聚物特性粘度适中、ＡＡ用量为５．５份（ＢＡ用量固定为１００份）、ＢＡ预辐射剂量为１６．０ｋＧｙ、Ｓｔ预辐射剂量为３２．０ｋＧｙ时，制得的接枝共聚物的粘接性能最为理想     

橡胶硫化曲线变化的数学模型拟合：I.有返原现象的硫化曲线

提出了用组合模型ｙ（Ｐ）＝ｆ１（ｔ）＋ｆ２（ｔ）描述硫化过程转矩化过程转矩Ｐ的变化。式中ｆ１（ｔ）和ｆ２（ｔ）分别表示硫化反应和老化反应对Ｐ变化的贡献部分。模型参数的确定采用Ｔｏｂｏｌｓｋｙ提出的ＰｒｏｃｅｄｕｒｅＸ方法。在孟山都流变仪上测定了天然橡胶在１８０，１７０，１６０，１５０，１４０℃时的硫化曲线。得到：ｙ（Ｐ）＝１－（Ｐ－Ｐｏ）／（Ｐ∞－Ｐｏ）；ｆ１（ｔ）＝Ａｅｘｐ［Ｋ１（ｔ－ｔｏ）］；     

国外消息

Ｄｙｓｔａｒ将其分散染料统一冠名Ｄｉａｎｉｘ从１９９９年１月起，Ｄｙｓｔａｒ公司的所有分散染料统一以Ｄｉａｎｉｘ商标出售。原有的Ｒｅｓｏｌｉｎ（Ｂａｙｅｒ）和Ｄｉａｎｉｘ（Ｈｏｅｃｈｓｔ／Ｍｉｔｓｕｂｉｓｈｉ）将合并，并依据应用将其部分更名以形成单一...     

隧道活化炉氯化锌法生产粉状活性炭的试验

本文介绍以木屑为原料，采用氯化锌法在隧道活化炉生产粉状活性炭的新工艺。中试生产规模３０－５０ｔ／ｙ，产品质量均达到或超过部颁标准，废气，废水大大低于国家排放标准，减少对环境的污染。     

隧道活化炉氯化锌法生产粉状活性炭的试验

本文介绍以木屑为原料，采用氯化锌法在隧道活化炉生产粉状活性炭的新工艺。中试生产规模３０～５０ｔ／ｙ，产品质量均达到或超过部颁标准，废气、废水大大低于国家排放标准，减少对环境的污染。     

2000t／d水泥生产线自动化系统国产化应注意的若干问题

２０００ｔ／ｄ水泥生产线自动化系统国产化应注意的若干问题顾如生陕西省耀县水泥厂（７２７１００）１概述就目前已建成的新型干法生产线来看，大中型水泥生产线基本上都采用集散型控制系统（又称分布式计算机系统）ＤＣＳ（ＤｉｓｔｒｉｂｕｔｅｄＣｏｎｔｒｏｌＳｙｓ...     

国内外循环床锅炉的发展及其特点

论述了国内外几种典型循环床锅炉的发展，介绍了华中理工大学煤燃烧国家重点实验室与武昌锅炉容器厂联合开发的１０ｔ／ｈ，２０ｔ／ｈ，３５ｔ／ｈ，７５ｔ／ｈ，１３０ｔ／ｈΠ型下排气旋风分离器循环床锅炉及其特点。     

中国大陆赖氨酸需求大增

随着中国大陆饲料工业的发展，Ｌ赖氨酸的消费量也逐年增加，年需求量目前约４万ｔ，估计２０００年将会急速增加到８万ｔ。目前中国大陆赖氨酸产能仅２－３万ｔ，每年都需进口。南宁赖氨酸厂正由１万ｔ／ａ扩建为３万ｔ／ａ，川化味之素公司也由１万ｔ／ａ扩建为３万ｔ／ａ，福建大泉赖氨酸厂由０－３万ｔ／ａ扩建为０－６万ｔ／ａ。并计划在玉米主要产地的黑龙江、吉林、山东等省新建２～４万ｔ／ａ的新厂。中国大陆赖氨酸需求大增     

烧碱纯度对离子交换树脂再生度的影响分析

我厂５０００ｔ／ｙ三胺精制工艺是采用离子交换树脂净化工艺。目前使用的树脂为强碱性阴离子交换树脂。新购置的树脂是氯型的，通过用稀的ＮａＯＨ溶液进行转型变成ＯＨ型树脂，可用于三胺精制生产。使用后的树脂采用ＮａＯＨ溶液进行再生，将酰胺型树脂和部分氯型树脂再...     

Diffusion During the Supercritical Drying of Silica Gels

Drying is the most critical elaboration step of large monolithic and crack-free silica aerogel plates. In the present work, we are studying the supercritical CO₂ drying and more precisely the first step, here called the supercritical washing step. This phase consists of replacing the liquid phase contained in the nanopores with supercritical CO₂. Within this study, this step is governed by molecular diffusion through the gels. These phenomena were investigated experimentally in order to estimate the duration of the washing step. The experimental results were then fitted with an analytical mass transfer model to identify the effective diffusion coefficient.     

Extraction of tocopherols from the deodorized distillate of soybean oil with liquefied petroleum gas

Deodorizer distillate, produced during the last processing step of edible oil refinement, is a mixture of tocopherols, sterols, fatty acids, glycerides, hydrocarbons, water and other materials. The amount of tocopherols in deodorizer distillate is large enough to be considered as raw material for vitamin E preparation. In this work, separation of tocopherols from sterols has been achieved using liquefied petroleum gas (LPG) extraction. LPG was chosen as extraction solvent in order to improve extract recovery and prevent tocopherol degradation.     

The Limiting Distribution of the Residual Processes in Nonstationary Autoregressive Processes

The weak limit of the partial sums of the normalized residuals in an AR(1) process y _t = ρ y _{t −1} + e _t is shown to be a standard Brownian motion W ( x ) when |ρ| ≠ 1. However, when |ρ| = 1, the weak limit is W ( x ) plus an extra term due to estimation of ρ. Asymptotic behaviour of the partial sums is investigated with ρ = exp( c )/ n ) in the vicinity of unity, yielding a c -dependent weak limit as n ←∞, whose limit is again W ( x ) as | c | ←∞. An extension is made to nonstationary AR( p ) processes with multiple characteristic roots on the unit circle. The weak limit of the partial sums has close resemblance to that for the polynomial regression.     

我国煤制乙二醇竞争力分析

介绍了我国乙二醇市场现状,截至2019年底,我国乙二醇总产能为1 159万吨/年,其中,煤制乙二醇产能达491万吨/年,2020年还将有近400万吨/年的产能释放。煤制乙二醇技术逐渐成熟,所以短期内市场存在产能增速较快但产量增速缓慢的不匹配状态。比较了石油制乙二醇和煤制乙二醇生产工艺路线的成本,从生产成本、产品质量和物流方式3个维度分析了煤制乙二醇的市场竞争力,得出了煤制乙二醇的发展具有广阔前景,并根据国内乙二醇市场的远期发展趋势,提出了发展建议。     

乡镇矿山科学管理出效益的体会

柳树沟磷矿开工时技术力量十分薄弱，以自己培养为主．广泛争取设计院等单位支持．基建工程严格按设计施工，并且建立健全各项规章制度，实行科学管理，安全生产文明生产，扩大生产规模，已由年产９万ｔ扩大到２０万ｔ，企业经济效益、社会效益十分显著，成为乡镇矿山典范，磷矿企业的标兵．     

网络丝的网络数与网络牢度关系的研究

利用丝道直径不同的网络器,在各种工艺条件下,对长丝进行网络加工,分析了加工参数(空气压力、超喂率、加工速度)对网络数和网络牢度的影响。利用最小二乘法求得网络数与网络牢度的回归方程,并阐明了网络数与网络牢度之间的关系随丝道直径和加工参数变化的规律。证明了固定的网络器,在一定的工艺条件下,可以通过网络数来估算网络牢度。     

The contribution of the utilization option to reducing the CO2 atmospheric loading: research needed to overcome existing barriers for a full exploitation of the potential of the CO2 use

The use of CO₂ (biological/chemical/technological) is the only technology that may contribute to reducing the atmospheric loading while generating a profit. In this paper some options that may find an early industrial application are considered, and barriers that need to be overcome for their full implementation are analyzed. Options that may produce a reduction of the immission into the atmosphere of the order of 1 Mt/y of CO₂ are considered. The estimate of the atmospheric reduced loading, in case the various options are implemented, ranges at 300 Mt/y in the short-medium term, with an upper limit of 700 Mt/y in the long term.     

The effect of reaction conditions on the urethane prepolymer formation

Summary In the two step synthesis of urethane copolymers, most statements from the literature assume that all of the diisocyanate will be used up in the formation of the isocyanate-endcapped polyol. However, a computerized simulation indicated the formation of three kinds of product.Synthetic experiments were conducted to study the first step of this reaction. It was found that not all of the intermediates reacted in the first step of the synthesis. Some diisocyanate remained unreacted and a polyol dimer was formed. Two different polyols were used in this study. When a polyol has primary hydroxyl groups on each end, more unreacted diisocyanate was present at the completion of the reaction than when the polyol has a primary and a secondary hydroxy end. The investigation of the solvent effect revealed that the solvent used had little effect on the prepolymer formation. The study of the temperature effect showed that more unreacted diisocyanate was obtained at the higher temperature for the 4,4-diphenylmethane diisocyanate/polytetramethylene glycol reaction.     

氰化钠法生产EDTA钠盐先进工艺

与传统工艺(经由EDTA中间体)比较,氰化钠法生产EDTA钠盐先进工艺具有如下优点:由EDTA四钠原液生产二钠盐,减少3道工序,硫酸(100%)和氢氧化钠(100%)单耗分别降低0.350t/t和0.216t/t;由二钠盐生产四钠盐减少一道工序,硫酸和氢氧化钠单耗分别降低0.272t/t和0.173t/t;产品纯度99.3%～99.5%,产率93%～95%(以乙二胺计),达到文献水平。     

TIME SERIES RESIDUALS WITH APPLICATION TO PROBABILITY DENSITY ESTIMATION

Abstract. A linear stationary and invertible process y _t models the second-order properties of T observations on a discrete time series, up to finitely many unknown parameters θ. Two estimators of the residuals or innovations ɛ _t of y _t are presented, based on a θ estimator which is root- T consistent with respect to a wide class of ɛ _t distributions, such as a Gaussian estimator. One sets unobserved y _t equal to their mean, the other treats y _t as a circulant and may be best computed via two passes of the fast Fourier transform. The convergence of both estimators to ɛ _t is investigated. We apply the estimated ɛ _t to estimate the probability density function of ɛ _t . Kernel density estimators are shown to converge uniformly in probability to the true density. A new sub-class of linear time series models is motivated.