分子筛吸附器自动再生系统在DCS中实现

介绍了空分装置的分子筛吸附器再生系统的自动控制原理，选用集散控制(DCS)系统实现控制过程，解决了原仪表控制系统的设计、操作和运行上存在问题。新系统更合理、更安全可靠、操作更方便、直观，同时提高了净化工艺的自动化水平。     

Chemical vapor deposition of amorphous ruthenium-phosphorus alloy films

Chemical vapor deposition growth of amorphous ruthenium-phosphorus films on SiO₂ containing ∼ 15% phosphorus is reported. cis-Ruthenium(II)dihydridotetrakis-(trimethylphosphine), cis-RuH₂(PMe₃)₄ (Me = CH₃) was used at growth temperatures ranging from 525 to 575 K. Both Ru and P are zero-valent. The films are metastable, becoming increasingly more polycrystalline upon annealing to 775 and 975 K. Surface studies illustrate that demethylation is quite efficient near 560 K. Precursor adsorption at 135 K or 210 K and heating reveal the precursor undergoes a complex decomposition process in which the hydride and trimethylphosphine ligands are lost at temperatures as low at 280 K. Phosphorus and its manner of incorporation appear responsible for the amorphous-like character. Molecular dynamics simulations are presented to suggest the local structure in the films and the causes for phosphorus stabilizing the amorphous phase.     

含铼钼精矿焙烧尾气收尘与铼回收一体化装置的研制与应用

研制了一种含铼钼精矿焙烧尾气收尘和铼回收装置,该装置将自激式除尘器技术与球面筛板塔技术相结合:采用自激式除尘器进行收尘和铼回收;采用球面筛板淋洗塔进行进一步收尘和铼回收,并将其应用到工程实际中。这是国内首次成功地将此类装置应用于钼精矿焙烧尾气收尘和铼回收生产实践中。经过生产实践,证明该装置切实可行,淋洗效率高,并具有结构简单、操作方便、成本低和能耗小等特点。此外,此除尘系统还可应用于冶金矿山、化工和建材等领域中的湿法除尘。     

用高分子复合材料修复轧管机组大型构件

介绍采用高分子复合材料修复用于钢管生产的轧管机组大型构件的方法。重点介绍机架轴承座孔的修复工艺流程 ,修复定位 ,技术操作要点及修复效果。     

香豆胶衍生物的化学结构及稳定性研究

将市售商品溶于水,用异丙醇沉析提纯,溶于0.1 mol/L NaNO3纯水溶液中,经0.5μm滤膜过滤后用水相凝胶渗透色谱法(GPC)测定,测得香豆胶(FG)、羟丙基香豆胶(HPFG)、阳离子香豆胶(CFG)的数均、重均相对分子质量Mn、Mw分别为:1.19×105、3.36×105,8.52×104、2.85×105,9.33×104、2.87×105。用甘露聚糖链在碱性条件下醚化时发生降解,解释两种改性FG的相对分子质量较FG低而多分散性(Mw/Mn)较FG高的测试结果。认为商品FG的1%水溶液黏度(1300 mPa.s)高于商品HPFG和CFG(分别为705和610 mPa.s)的原因是前者相对分子质量较高且残渣含量也较高(~10%,后二者为1%~2%)。HPFG的取代度为0.12,根据文献发表的13C-NMR数据确认HPFG分子链上羟丙基取代位置为C6。讨论了香豆胶(半乳甘露聚糖)的化学结构。热重分析法测定的热稳定性,HPFG高于CFG,CFG又高于FG。图6表3参13。     

Effect of organic dopants on electrodeposition and characteristics of polyaniline under the varying influence of H2SO4 and HClO4 electrolyte media

Electrodeposition of conducting polyaniline (Pani) was made under potentiostatic condition at pH 1.0 in different electrolyte media (H₂SO₄ and HClO₄) in the absence and presence of two organic dopants, disodium salts of naphthalene-1,5-disulphonic acid (NSA) and of catechol-3,5-disulphonic acid (CSA). The rate and yield of Pani deposition were dependent on the acid medium and the dopant employed. NSA in H₂SO₄ caused an increase in rate and yield but CSA decrease when compared to the rate and yield of H₂SO₄ alone. In HClO₄ medium, both the dopants showed a decrease. With regard to DC electrical conductivity, both the dopants exhibited an enhancement in H₂SO₄ medium but NSA a decline in HClO₄. Characterisation of the electrosynthesised polymer samples by various instrumental techniques (cyclic voltammetric: CV, FTIR, UV-Visible: UV-Vis, EPR, XRD, TGA and DTG methods) revealed that between the two acid media, H₂SO₄ was the better one. Further, it enlightened the role of two organic dopants in relation to the acid media. The advantageous role of NSA in H₂SO₄ had origin on its molecular characteristics such as non-polarity, larger π-electron cloud etc., while CSA could not perform such a role because of its easily oxidisable hydroxyl groups. In HClO₄, however, both the dopants could play only an unfavourable role owing to its greater polarity and oxidizing power than H₂SO₄.     

Properties of Quaternary Alloy Magnetic Semiconductor (InGaMn)As Grown on InP

We have studied properties of quaternary alloy magnetic semiconductor (InGaMn)As grown on InP substrates by low-temperature molecular-beam epitaxy (LT-MBE). A large MCD peak whose intensity is larger than 500 mdeg for (InGaMn)As was observed. This peak intensity was about three times larger than that of typical (GaMn)As films. Relatively high Curie temperature of 83 K of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was observed by Hall measurements. The carrier concentration of [(In_0.53Ga_0.47)_0.88Mn_0.12]As was estimated to be more than 1.0 × 10²¹ cm^–3 by using the Curie–Weiss fitting of the Hall coefficient R _H, indicating that more than 40% of Mn atoms are activated. This means that (InGaMn)As has a higher activation ratio of Mn as acceptors than (GaMn)As.     

A generalized equation for the prediction of melting temperatures of homopolymers and copolymers

A generalized equation was derived to calculate the melting temperatures of homopolymers and copolymers. The Gibbs‐Thomson equation for homopolymers and a modified application to copolymers were derived using the proposed equation. The melting temperature T_m⁰ in the Flory equation corresponds to the melting temperature T_m^C,∞ of copolymer crystals with stems of infinite length. Also, T_m^C,n*, the melting temperature for copolymer crystals with stems containing the maximum possible number of structural units, n*, should be used instead of T_m⁰ as the basis of supercooling in crystallization. The proposed equation shows good agreement with experimental data for α‐alkene‐ethylene homogeneous copolymers.     

Non-steady-state model for kinetics of free radical polymerization, 4. Direct thermal initiation

This paper deals with the non-steady-state kinetics of direct thermal initiated polymerization. The initiation is assumed to be a bimolecular reaction of the monomer. The relationship between the radical concentration and the monomer conversion is rigorously derived. In further treatment a few very close approximations are introduced based on the fact that the number of monomer molecules reacting in the initiation step is much less than that consumed in the propagation step for a process producing high polymer, and the value of the rate constant for propagation or chain transfer is much lower than that for chain termination. Expressions for various molecular parameters, such as molecular weight distribution, number-average and weight-average degrees of polymerization, and dispersity, are given. Several numerical examples are provided.