GB 50205取消焊工钢印要求的意义

该文回顾了我国引进苏联钢结构工程施工验收标准、增加焊工钢印要求的标准演变历程,讲述我国古代物勒工名制度与我国钢结构工程施工质量验收规范中焊工钢印规定的关系,并分析焊工钢印规定存在的历史原因、技术弊端.该文认为,应加强事前工艺评定和焊缝检测管理,借助更具可追溯性的施工记录、竣工图、声像资料等现代档案管理技术实现与实物分离记责.     

基于C6711处理器cdma2000 1X系统前向信道信号的处理

在cdma20001x前向信道中,要对一段信号进行传送,一般选用QPSK调制,因为QPSK调制比QAM更适合噪音环境。采用TI6000系列的TMS320C6711芯片处理前向信道信号,可以对复杂性和实时性较高的信号做采集、量化、编码、调制等实时处理,主要功能通过软件编程实现,从而使系统具有结构灵活、可靠性高、可扩展等优点。     

战术战斧导弹的五大新特点

战术战斧导弹(Block 4)是美海军下一代的巡航导弹，按计划将于2004年装备海军，计划从2002年开始的第一个5年内生产1343枚。这极大地补充了现在战斧Blcok 2／3导弹的库存。该导弹既可以由水面舰艇发射，也可以由潜艇发射，在“沙漠风暴”中第一次得以使用。战术战斧导弹将在以下几个方面的性能进行改进和提高：发射平台任务规划能力、飞行中重新定位、巡航、作战摧毁评估能力以及飞行中性能状态报告。     

国产TRT在马钢2500m^3高炉上的应用

对马钢2500m^3高炉应用国产TRT的情况进行总结，认为该国产机组具有工艺合理、投资少、节能降耗、环保效益好等优点。     

马钢高炉MG法炉渣处理工艺的开发与应用

对MG法炉渣处理工艺的开发及其在马钢2 500m3高炉上的使用情况进行了总结.生产实践表明,MG法炉渣处理工艺的开发与应用是成功的.     

用数码相机拍摄证件照

用数码相机拍摄证件照不仅方便快捷，而且经济实惠，下面笔者谈谈自己用数码相机拍摄证件照的一些体会和方法。     

Multifunctional hydrogels that promote osteogenic hMSC differentiation through stimulation and sequestering of BMP2

The extracellular environment controls many cellular activities thereby linking external material cues to internal cell function. By better understanding these processes, synthetic extracellular material niches can be tailored to present cells with highly regulated physical and/or chemical cues that promote or suppress selected cell functions. Here, poly(ethylene glycol) (PEG) hydrogels were functionalized with fluvastatin-releasing grafts and growth factor binding heparin domains to enable the dynamic exchange of information between the material and cells from the outside-in and inside-out (i.e., bidirectional signaling). By incorporating a fluvastatin-releasing graft and carefully controlling the dose and temporal release, materials were designed to promote bone morphogenic protein (BMP2) and alkaline phosphatase (ALP) production by human mesenchymal stem cells (hMSCs). When the release of fluvastatin was controlled to occur over 2 weeks, BMP2 and ALP production was increased 2.2-fold and 1.7-fold, respectively, at day 28 compared to hMSCs cultured in the absence of fluvastatin. By introducing a heparin functionality into the gel to sequester and localize the hMSC-produced BMP2, the osteogenic differentiation of hMSCs was further augmented over fluvastatin delivery alone. Osteopontin and core binding factor α1 gene expression was 6-fold and 4-fold greater for hMSCs exposed to fluvastatin in the presence of the heparin functionalities, respectively. These results demonstrate how multifunctional gels that interact with cells in a bidirectional manner can efficiently promote selected cell functions, such as the osteogenic differentiation of hMSCs.     

国产TRT在马钢2500m3高炉上的应用

对马钢2500m3高炉应用国产TRT的情况进行总结,认为该国产机组具有工艺合理、投资少、节能降耗、环保效益好等优点.     

延时爆破物料抛掷模型试验

延时爆破物料抛掷模型试验Ｄ．Ｓ．普利斯等由于重视采矿活动中环境监测，因此在开采露天矿时应用新技术是必要的。一个重要的环境问题是地下水酸化，这是由于地层，如典型的页岩，含有高于平均水平的硫铁矿成分。地下水酸化在露天矿中明显加快，因为相对不透水的页岩层爆...