用氢还原铁矿及对CO2生成的影响

概括了利用氢还原铁矿石的情况.从理论上讲,氢还原意味着零CO2排放.评述了氢反应能力和现有工艺.讨论了氢气来源和相关的CO2效应.并对成本进行了估计和比较.     

利用有限元法对板坯电磁搅拌中电磁场的数值模拟

基于Maxwell方程,建立了板坯内部电磁场的数学模型.为了满足计算机求解的需要,对数学模型进行了离散化和简化处理.使用有限元法对简化后的数学模型进行了仿真,得到了电磁场等势线图和磁力分布图.通过对磁场分布进行定性分析,得到了在其他条件不变的情况下,电磁力和电流强度、电磁力和电流频率的变化关系.     

城镇化进程中的土地资本化问题探析

工业化是现代化发展的起点和核心内容.工业化导致要素的空间聚集和大规模的人口迁徙,促进了城市的形成和发展.工业化所带来的先进技术,也彻底改造了传统农业生产方式.但是,我国目前工业化和农业现代化的发展却受到了空间的制约.在这种情况下,只有提升空间使用效率才能解决空间供求的巨大矛盾.这个提高空间使用效率的方法就是土地资本化.本文理论联系实际,分析了城镇化进程中土地资本化的相关问题,为城镇化提供更多可持续发展的空间.     

天铁医疗保险基金支付管理系统的设计与应用

天铁集团为加强社保的信息化管理,设计开发了天铁医疗保险基金支付管理系统.对该系统的主要功能、算法和约定进行了详细叙述.该系统的可靠性和实用性强,提高了工作效率和准确率,实现了医疗保险基金的高效监管和有效合理使用.     

2250热轧过程控制系统的应用

首钢京唐联合钢铁公司2250热轧生产线采用了日本tmeic公司的过程控制系统.在系统结构设计上,采用了四级网络,并使用了EGD网络与特殊仪表进行通信以及对板型实时控制,达到了良好的通信效果.引入了zone_director和Piece_director概念,对跟踪区和piece分别管理.另外在模型计算方面,结合了东芝和GE模型的优点,取得了满意的产品质量.     

MPEG-4在DSP上的实现

采用TMS320C6711 DSP芯片实现了MPEG-4视频编码器.本文介绍了编码器硬件和软件的结构设计,讲述了视频采集和TMS320C6711 DSP的特性.简单介绍了MPEG-4的算法原理,详细阐述了核心算法的设计--运动估计算法.从DSP的结构和特性出发,阐述了软件优化的关键技术,给出了测试结果.     

技艺需要与政治——自由和平等关系的疏朗

人类是通过技艺满足需要的动物.由于需要之间、技艺之间的冲突,人也是政治动物.技艺在近现代取得了快速的发展.在政治上,人类产生了对自由和平等的要求.自由和平等是冲突的,不过二者都根植于人的需要和技艺.因此对自由和平等的思考应该深入到这个层次.现代社会的基本特征是,人的需要以获利为形式得到极大的张扬,政治领域和经济领域被分离.这个事实值得警惕和反思.毕竟,人既是生产动物,也是政治动物.     

ICP-OES法测定钽中钙、铝、镁、铌、硅和钨

用ICP-OES光谱仪对钽中钙、铝、镁、铌、硅和钨的测定进行了研究和探讨.对样品中元素的分析谱线,仪器分析参数,准确度和精密度进行了研究,确定了最佳实验条件.相对标准偏差不大于6.41％.方法具有良好的精密度和准确度,操作简单、快捷.     

H型钢轧制腹板波浪的研究

对H型钢轧制过程中腹板波浪的产生机理及形成条件进行了研究.首先利用解析的方法给出了腹板产生屈曲的临界应力和应变.使用有限元软件MSC.Marc,建立了H型钢轧制的弹塑性有限元模型,并成功地仿真出了腹板屈曲现象,给出了此过程中轧件的应力和变形规律.得到了出现腹板波浪时腹板和翼缘相对压下量的临界比值和半波长等特征值参数.     

大西洋铜公司韦尔瓦精炼厂的最新改进

西班牙韦尔瓦精炼厂1970年开始生产,1995年采用了艾萨永久阴极铜技术.引进艾萨法后,作业不断改进,产量高出设计能力15%,且阴极质量极佳.同时,还做了一些重大改进,例如,2000年对电解液净化过程进行了改造,使得大西洋铜公司完全排除了装运韦尔瓦冶金联合企业之外的电解液.然而这些改进又产生了一些技术难题和操作问题,例如钝化现象和电解液污染.本文介绍了最近几年的工艺变化和操作改进.     

UV- and gamma-radiation sensitive mutants of Arabidopsis thaliana

Arabidopsis seedlings repair UV-induced DNA damage via light-dependent and independent pathways. The mechanism of the "dark repair" pathway is still unknown. To determine the number of genes required for dark repair and to investigate the substrate-specificity of this process we isolated mutants with enhanced sensitivity to UV radiation in the absence of photoreactivating light. Seven independently derived UV sensitive mutants were isolated from an EMS-mutagenized population. These fell into six complementation groups, two of which (UVR1 and UVH1) have previously been defined. Four of these mutants are defective in the dark repair of UV-induced pyrimidine [6-4]pyrimidinone dimers. These four mutant lines are sensitive to the growth-inhibitory effects of gamma radiation, suggesting that this repair pathway is also involved in the repair of some type of gamma-induced DNA damage product. The requirement for the coordinate action of several different gene products for effective repair of pyrimidine dimers, as well as the nonspecific nature of the repair activity, is consistent with nucleotide excision repair mechanisms previously described in Saccharomyces cerevisiae and nonplant higher eukaryotes and inconsistent with substrate-specific base excision repair mechanisms found in some bacteria, bacteriophage, and fungi.     

炼钢厂钢包周转率的影响因素

针对某炼钢厂生产流程建立钢包周转过程仿真模型,对影响钢包周转率的热修时间、生产钢种和修包包龄等因素进行仿真研究.仿真结果表明:热修时间增加,钢包周转率下降,当日产45炉典型钢种,热修时间在0~20 min范围内钢包周转率为6.43,而当热修时间为50~60 min时钢包周转率为5.0;生产不同钢种的钢包周转率差别较大,日产41~50炉的SPHC钢种时,钢包周转率最大值为6.28,最小值为5.63,而生产同样炉数的X70钢种时钢包周转率最大值为5.0,最小值为4.55;修包包龄增加,钢包周转率提高,日产48炉典型钢种,修包包龄为40次时钢包周转率为4.0,修包包龄为45次钢包周转率达极限值6.86.     

Characterization of postreplication repair in mutagen-sensitive strains of Drosophila melanogaster

Mutants of Drosophila melanogaster, with suspected repair deficiencies, were analyzed for their capacity to repair damage induced by X-rays and UV radiation. Analysis was performed on cell cultures derived from embryos of homozygous mutant shocks. Postreplication repair following UV radiation has been analyzed in mutant stocks derived from a total of ten complementation groups. Cultures were irradiated, pulse-labeled, and incubated in the dark prior to analysis by alkaline sucrose gradient centrifugation. Kinetics of the molecular weight increase in newly synthesized DNA were assayed after cells had been incubated in the presence or absence of caffeine. Two separate pathways of postreplication repair have been tentatively identified by mutants derived from four complementation groups. The proposed caffeine sensitive pathway (CAS) is defined by mutants which also disrupt meiosis. The second pathway (CIS) is caffeine insensitive and is not yet associated with meiotic functions. All mutants deficient in postreplication repair are also sensitive to nitrogen mustard. The mutants investigated display a normal capacity to repair single-strand breaks induced in DNA byX-rays, although two may possess a reduced capacity to repair damage caused by localized incorporation of high specific activity thymidine-3H. The data have been employed to construct a model for repair of UV-induced damage in Drosophila DNA. Implications of the model for DNA repair in mammals are discussed.     

一种改进的Ad Hoc网络路由协议AODV-DD

针对AODV路由协议进行本地修复时存在节点移动剧烈区域本地修复重复发生和本地修复没有考虑已存在下游链路的问题,提出一种新的带决策的双向修复AODV路由协议（AODV—DD）,新协议对AODV的本地修复算法进行了改进,根据节点本地修复次数对是否发生本地修复进行决策,并且在修复时进行双向修复的算法优化。NS2中的仿真实验表明,改进本地修复算法后的路由协议性能有了一定的提升,尤其在时间延迟方面有较大的改进。     

Alternatives to platelet transfusion]

It is well established that a full-thickness articular cartilage defect is repaired with a fibrocartilaginous tissue, cells of which are derived from undifferentiated mesenchymal stem cells in the bone marrow. To characterize the repair cells biochemically, full-thickness defects were created in rabbit knee joints and the repair tissues taken at 3, 6, and 12 weeks after surgery. The repair cells were cultured and examined biochemically to investigate the effects of four exogenous growth factors with regard to the metabolism of type II collagen and proteoglycans. A significant increase of carboxy-terminal type II procollagen peptide production was observed in the conditional medium of the repair cells, especially taken at 6 weeks after surgery, in the presence of each growth factor. Glycosaminoglycan content was also increased and proteoglycan synthesis stimulated. The repair cells taken at the early stage of the repair process could originally have more activity of type II collagen synthesis, and the growth factors used could enhance the differentiation of the repair cells in vitro.     

KGLF-11励磁装置插件离线调试台的设计与应用

设计和制作的KGLF-11励磁装置插件离线调试台，具有脱离生产设备修复调试主要插件的功能。调试台对于加快检修速度，提高检修质量，改善检修环境，降低检修成本等方面的作用十分突出，且具有体积小，成本低，搬运方便等特点。