尿素水解过程的计算模拟

通过对尿素水解反应平衡常数的求取以及 Ｎ Ｈ３  Ｃ Ｏ２  Ｈ２ Ｏ Ｃ Ｏ（ Ｎ Ｈ２ ）２ 体系的相平衡计算方法的建立，采用内外双层法实现了尿素水解工段的计算机模拟，为大型合成氨厂尿素水解工段的改造提供了理论分析的依据。     

3万吨／年过磷酸钙造粒工段的改造

３万吨／年过磷酸钙造粒工段的改造刘新平（新疆昌吉市磷肥厂８３１１００）中图分类号ＴＱ４４２．１１图１改造前的工艺流程图２改造后的工艺流程我厂３万吨／年粒状过磷酸钙生产线于１９８３年建成投产。１９９１年又投资４２万元对造粒工段进行改造，使粒肥日产能力达...     

生化处理含酚污水几个问题的探讨

生化处理含酚污水几个问题的探讨李大全（黑龙江化工总厂齐齐哈尔市１６１０４１）我厂的含酚污水主要由回收工段、精苯工段及焦油工段等排出，其中回收工段合酚污水量为６５ｍ３／ｈ，浓度为２００～２５０ｍｇ／Ｌ；焦油工段为２０ｍ３／ｈ，浓度为１５０～２５０ｍｇ／...     

提高精炼气质量一法

提高精炼气质量一法我厂合成氨生产能力为２万ｔ／ａ，精炼工段采用７００铜塔，内装阶梯型塑料，配备２台１０ｍ３、１台４ｍ３铜泵，设备能力是够宽余的。但由于近两年来，煤气中硫化氢含量较高（脱硫前３￣４ｇ／ｍ３），脱硫后有超指标现象，造成铜液中硫化铜沉析。虽...     

因地制宜进行合成氨挖潜技改

以最少的投资，最短的时间，对合成氨２＾＃系统的造气、变换、脱硫、脱碳、压缩、合成等工段均作了因地制宜的改造，使生产能力从３万ｔ／ａＮＨ３增加到４万ｔ／ａＮＨ３，达到了与目前尿素装置相匹配的目的。     

4Al＋3TiO_2＋3C化学反应的差热分析研究

通过差热分析曲线和物相分析等研究了４Ａｌ＋３ＴＯ_２＋３Ｃ普通化学反应和自燃烧化学反应的特点。研究结果表明，在一定的升温速率下Ａｌ、ＴｉＯ_２、Ｃ相互之间均能发生相互化学反应；随着升温速率的提高，Ａｌ、ＴｉＯ_２、Ｃ任意两组元之间的相互化学反应受到抑制。运用４Ａｌ＋３ＴｉＯ_２＋３Ｃ自蔓延高温合成反应制备了Ａｌ_２Ｏ_３－ＴｉＣ陶瓷复合材料。     

小氮肥生产装置挖潜改造的经验总结

介绍了小氮肥生产装置挖潜改造的经验：适当改造变换工段主要设备的内部结构,即将其生产能力从１５万ｔ／ａ扩大至３万ｔ／ａ;用Φ８００的合成塔替代原合成塔,就能将合成工段的生产能力从２万ｔ／ａ扩大至３万ｔ／ａ。     

戈尔过滤器的改造

１存在问题１９９９年２月以来，我厂在煤气脱硫工段使用了戈尔过滤器处理硫浆，但因操作不正常而造成民用煤气中的硫化氢含量超标，分析其原因有以下几点。（１）因戈尔过滤器的滤袋材质为膨体聚四氟乙烯，滤袋既不能打褶，不允许粘上油污，又不能碰伤滤袋表面，故在操作中需进行频繁清洗，使袋的破损率较高。（２）过滤器用压缩空气控制气动挠性阀的开关作业，在夏季，因小型空压机供给的压缩空气存在杂质多、压力低和积水严重等问题，一般２至３天就会因发生气源堵塞而被迫停产，以清洗空气过滤器、减压器和油雾器等设备。（３）过滤器在…     

半水煤气脱硫工艺改造初探

半水煤气脱硫工艺改造初探黄榜元，李（江西氨厂）生产实践及测定结果表明，以煤为原料的氨合成装置工艺中，半水煤气脱硫塔仅能脱除绝大部份的无机硫（Ｓ２－），不能脱除有机硫。虽然在变换工段大部分有机硫转变为无机硫（Ｈ２Ｓ），但仍有相当数量（３～５ｍｇ／ｍ３）...     

磷酸—铵中和反应器的技改

个旧市化肥厂年产３万吨磷酸－铵装置由化工部第三设计院及上海化工研究院设计，采用加压喷雾干燥工艺（见图１），生产粉粒状磷酸一铵。磷铵工段中和反应器是整个工段的关键设备。 中和反应器规格为：直径 １６００ ｍｍ，高２ ７８６ｍｍ，设计温度 １７０℃，工作压力 ０．２１４ ＭＰａ，采用涡轮圆盘平直 ６片桨叶，搅拌器转速 ４００ ｒ／ｍｉｎ，配功率 ７． ５ ｋＷ，无挡板，轴密封型式为填料密封，整台设备通过３个测重传感器支承于支座上，依据整个设备的质量变化进行加料及排料的操作。１运行中存在的问题 （１）由于中和器搅拌…     

Human IRP1 Translocates to the Nucleus in a Cell-Specific and Iron-Dependent Manner

Iron regulatory protein 1 (IRP1) is a bifunctional protein with mutually exclusive RNA-binding or enzymatic activities that depend on the presence of a 4Fe-4S cluster. While IRP1 is a well-established cytosolic protein, work in a Drosophila model suggested that it may also exhibit nuclear localization. Herein, we addressed whether mammalian IRP1 can likewise translocate to the nucleus. We utilized primary cells and tissues from wild type and Irp1^−/− mice, as well as human cell lines and tissue biopsy sections. IRP1 subcellular localization was analyzed by Western blotting, immunofluorescence and immunohistochemistry. We did not detect presence of nuclear IRP1 in wild type mouse embryonic fibroblasts (MEFs), primary hepatocytes or whole mouse liver. However, we observed IRP1-positive nuclei in human liver but not ovary sections. Biochemical fractionation studies revealed presence of IRP1 in the nucleus of human Huh7 and HepG2 hepatoma cells, but not HeLa cervical cancer cells. Importantly, nuclear IRP1 was only evident in iron-replete cells and disappeared following pharmacological iron chelation. These data provide the first experimental evidence for nuclear IRP1 expression in mammals, which appears to be species- and cell-specific. Furthermore, they suggest that the nuclear translocation of IRP1 is mediated by an iron-dependent mechanism.     

Synthesis and Crystal Structure of Diaqua(1,10-Phenanthroline-N,N')(Thiosulfato-O,S)Manganese(II). Biological Properties

The synthesis of diaqua(1,10-phenanthroline-N,N')(thiosulfato-O,S)manganese(ll) [Mn(phen)(S(2)O(3))(H(2)O)(2)] was investigated. Its structure was determined by single crystal X-ray diffraction from 2418 reflections (I > 3 sigma(I)) to a final value of R = 0.047 and Rw = 0.054. Crystal data are as follows : space group P(2) (1); a = 10.356(3), b = 7.097(3), c = 20.316(2) A, beta = 94.29(2) degrees , V = 1489.1(8) , A(3), Z = 2. There are two independent title compounds in the asymetric unit. Each manganese atom has a distorted octahedral Mn(SO)N(2)O(2) geometry with the S and O atoms (from two neighbouring thiosulfate ligands) mutually trans, two N atoms from the 1,10-phenanthroline ligand and two water oxygen. The thiosulfate group behaves as a bridging ligand, connecting, through sulfur and oxygen, Mn atoms related by the binary b translation, thus forming infinite chains running parallel to this axis. Infrared and electronic spectra are reported.     

互叶白千层挥发油气相指纹图谱的化学模式识别研究

以28批互叶白千层精油为研究对象,利用气相色谱法建立互叶白千层挥发油的指纹图谱,对其主要色谱峰进行归属,抽取并确定了9个色谱峰为共有特征峰,同时运用计算机辅助相似性评价、聚类分析及判别分析对其进行模式识别研究。三种方法得到的分类结果一致,相辅相成,可为评价互叶白千层挥发油以及对植物的质量评价和分类提供科学依据。     

Initial Sintering of Alumina and Hematite

Experimental measurements of the rate of shrinkage of pressed Al₂O₃ compacts, the neck growth between single-crystal Al₂O₃ spheres and plates, and the effect of particle size on neck growth between single-crystal Al₂O₃ spheres and plates are mutually consistent with the bulk diffusion sintering model. Tbe temperature dependence of the rate of shrinkage and neck growth in Al₂O₃ is characterized by an activation energy of 165 kcal. per mole. Apparent diffusion coefficients and temperature dependence calculated from the shrinkage of pressed compacts of Fe₂O₃ agree with measured diffusion coefficients for the diffusion of Fe in Fe₂O₃.     

溶剂脱水塔的研制

本文介绍了PTA装置溶剂脱水塔研制的基本经验,主要包括:2205双相不锈钢材料控制要求、2205双相不锈钢封头成型技术、2205双相不锈钢焊接、设备检验要求。     

硫铁矿制酸装置转化系统40kt／a改为60kt／a技改方案

介绍硫铁矿制酸装置转化系统40 kt/a扩能为60 kt/a的技改方案中,转化器、换热器和SO2主风机的技改措施为降低阻力,SO2体积分数最好由原8%提高到8.5%,可使换热器总阻力由13.6 kPa降到11.5 kPa,通过换热核算,部分换热器需更换;为提高转化率与保证尾气达标排放,最好将3+1 4段转化改为3+2 5段转化.     

红土镍矿分解实验研究

提出了酸碱交替分解、互为活化的工艺思路,通过实验确定了优化工艺条件和工艺流程。在优化工艺条件下,红土镍矿中Fe2O3、NiO、MgO、Co、SiO2分解率分别达到96.78%、99.62%、94.39%、100%和98.60%,从而为实现对红土镍矿的全元素综合利用奠定了基础。     

The structure of aminofunctional silane coupling agents: 1. γ-Aminopropyltriethoxysilane and its analogues

Gamma-aminopropyltriethoxysilane (γ-APS) and its analogues are studied as aqueous solutions as well as solids by Fourier transform infra-red spectroscopy (FT i.r.) and laser Raman spectroscopy. Emphasis was placed on a determination of the nature of the interaction between the amine groups and the residual silanol groups in partially cured solids. Comparison with γ-aminopropyltrisilanolate and partially cured solids obtained from γ-aminopropylmethyldiethoxysilane and γ-aminopropyldimethylethoxysilane lead us to conclude that the residual silanol groups are strongly hydrogen bonded to the amine groups as SiOH … NH₂ rather than SiO^? … ⁺NH₃. Hydrolysis of γ-APS at concentrations ranging 2–80% by weight showed that the solutions below 40% by weight have a few unhydrolysed alkoxy groups. The amine groups are mutually hydrogen bonded in unhydrolysed silane. However, in an aqueous solution and highly cured solids, the amine groups are either free or are interacting predominantly with water molecules.     

Solidus, Subsolidus, and Subdissociation Phase Equilibria in the System Fe-Al-O

The objective of this investigation was to determine phase relations in the system Fe-Al-O outside the composition and temperature regions of oxygen dissociation. Subsolidus phase equilibria were studied using inert atmospheres and the quenching technique. Compatibility relations are presented on isothermal sections at 1000°, 1250°, and 1350°C. Lattice parameters of iron-bearing spinel, Al₂O₃and Fe₂O₃ are given as a function of composition. Stability and some structural relations of the compound Fe₂O₃ Al₂O₃ are discussed. Solidus surfaces in the nondissociating portions of the system have been established using both published data and measurements made during this investigation.