论BFe30—1—1冷凝管生产工艺及其改进的途径

论述了ＢＥｅ３０－１－１冷凝管生产工艺的优点及主要问题，对现行工艺提出了改进方案。     

Preparation of branched polyacrylonitrile through self‐condensing vinyl copolymerization

Branched polyacrylonitrile (PAN) was prepared through a self‐condensing vinyl copolymerization of acrylonitrile and 2‐(2‐bromopropionyloxy)ethyl acrylate (BPEA). The branched architecture of the product was confirmed by NMR spectra and the average degree of branching (DB ) was estimated. Through a comparison of the intrinsic viscosity of the product with that of its linear analogue, the contraction factor g′ was calculated. It was found that the viscosity of the branched PAN was obviously lower that that of linear PAN. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

高能束合金化技术的研究现状和发展趋势

综述了国内外以激光为代表的高能束表面合金化技术的研究现状，报道了当前表面合金化技术的研究问题，对高能束表面合金化技术的趋势进行了分析。指出激光合金化改性层的质量控制、合金化过程的自动化、合金化技术在工业生产中的推广应用是该技术的重要攻关方向。     

Preparation of hyperbranched polymers by atom transfer radical polymerization

A cheap acrylic AB* monomer, 2‐(2‐chloroacetyloxy)‐isopropyl acrylate (CAIPA), was prepared from 2‐hydroxyisopropyl acrylate with chloroacetyl chloride in the presence of triethylamine. The self‐condensing vinyl polymerization by atom transfer radical polymerization (ATRP), a “living”/controlled radical polymerization, has yielded hyperbranched polymers. All the polymerization products were characterized by proton nuclear magnetic resonance spectroscopy (¹H NMR). CAIPA exhibited distinctive polymerization behavior that is similar to a classical step‐growth polymerization in the relationship of molecular weight to polymerization time, especially during the initial stage of the polymerization. However, a significant amount of monomer remained present throughout the polymerization, which is consistent with typical chain polymerization. Also, if a much longer polymerization time was used, the polymer became gel. As a result of the unequal reactivity of group A* and B*, the polymerization is different from an ideal self‐condensing vinyl polymerization: the branch structures of polymers prepared depend dramatically on the ratio of 2,2'‐bipyridyl to CAIPA. Hyperbranched polymers exhibit improved solubility in organic solvent, however, they have lower thermal stability than their linear analogs. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2114–2123, 2002     

Banach空间四阶边值问题的拟上下解方法

通过构造拟上下解的单调迭代过程,在拟解对之间利用Sadvoskii不动点定理获得了Banach空间四阶边值问题解的存在性     

某热电厂6 MW背压机组技术改造

某热电厂为提高能源利用率,拟新建一台6MW中温次高压背压式汽轮发电机组,替代2台3MW中温中压背压式汽轮发电机组,同时为解决公司淡季热负荷低造成系统稳定性差的问题,将一期1台3MW抽凝机组改造成后置机接在背压机排汽管道后,利用背压机排汽作为它的进汽,起到维持背压机稳定运行的作用。本文对此技术改造进行了分析,以高参数的背压机组替代低参数的背压机组,提高能源利用率,减少污染物排放总量,达到节约能源、保护环境、提高区域内居民生活质量的目的。     

汽轮机冲转调试中真空速降的原因分析及处理

新疆八一钢铁集团热电分厂一期工程2×25 MW次高压抽汽凝汽式机组2002年8月开始建设,2004年4月开始进行机组冲转调试.1、2号机组为武汉汽轮机厂产品,汽轮机型号为C25-4.9/0.98;凝汽器型号为N-2000-1;射水抽汽器型号为TDA-N25,抽气量为11.5 kg/h;射水泵型号为KQW150/370-37,扬程44 m.机组一段抽汽管路为Dg600,管路上设有水控止回阀、脉冲安全阀等设施,因为只是冲转调试阶段,一段抽汽与热网之间用盲板断开.机组在冲转调试前对各抽汽管路进行灌水打压试验,试验结果符合验收标准.     

Condensing Heat Transfer in Steam-Water Condensing-injector

An experiment on the direct heat transfer process between supersonic steam and subcooled water jet was performed, using a steam-water condensing-injector. Photographic observation provided information on the state of flow, and establishment of a critical separate steam-water flow was confirmed. The temperature and pressure distributions along the flow were measured and the effective coefficients of condensing heat transfer were evaluated from the observed data, based on a model embodying an idealized interface between vapor and liquid. In the vicinity of the water nozzle exit, where the vapor-liquid interface was distinct, the heat transfer coefficients obtained were 14–28 (cal/°C.cm².sec), and some correlation was observed among Nusselt, Reynolds and Jakob numbers, upon adopting the velocity and the physical properties of the steam phase. The relations Nu=6.0.Re ^0.9(Pr=1.04–1.10), and Re=1.8×10⁸.Ja ^3.0, i.e., Nu=1.6×10⁸.Ja ^2.7 were derived as a rough estimation. No clear correlation could be discerned in the corresponding data obtained from observation points further downstream, where a distinct steam-water interface no longer existed. In conclusion, it is proposed that, in deriving the correlations between Nu and Re or Ja, the physical properties of the vapor and the vapor-liquid relative velocity should be adopted, on account of the strong dependence of condensing heat transfer on steam velocity and water subcooling.     

氟里昂压缩冷凝机组的构成及其工作原理

文章主要介绍氟里昂压缩冷凝机组的构成及其工作原理，进行分析，以便大家详细了解，促进氟里昂压缩冷凝机组的技术发展及技术进步。     

提高背压式供热机组负荷适应性与运行经济性的方法

为使长沙天宁热电公司的热电联产机组能适应低负荷时的稳定与经济运行,提出在原有背压式汽轮机的排汽处串接低压凝汽式汽轮机的方法。实际证明,低压凝汽式汽轮机的增设既能使机组具有较好的热负荷适应性,又能维持机组运行参数的稳定,提高了机组运行的经济性。