实用型跳高架的制作

在日常教学和训练中所用的跳高架比较重且容易损坏,为此笔者根据跳高架的原理,利用废旧的镀锌管、三角铁和螺纹钢制作了实用型跳高架,重量比一般跳高架轻一倍以上,牢固耐用。一、制作材料及工具材料:直径2cm的镀锌管1根,长约200cm;直径3cm的镀锌管1段,长约8cm;边长3cm的三角铁2块,各长50cm;边长4cm的三角铁1块,各     

煤巷锚网支护在益新煤矿的应用与发展

本文简述了鹤岗矿业集团益新煤矿在煤巷锚网支护方面经历的几个阶段,和现阶段的应用l睛况,探索煤巷锚网支护的发展方向。     

Deformation mechanism of high-stress and broken-expansion surrounding rock and supporting optimization based on the gray correlation theory

Aiming at the large deformation and support problems of high-stress and broken-expansion surrounding rock, and taking 1 000 m level roadway of Mine II in Jinchuan as the research object, an investigation on the deformation and damage of roadway surrounding rock and an analysis of its mechanism were carried out. The gray correlation theory was used in support scheme optimization design. First, causes and mechanism of deformation of the 1 000 m horizontal transport channel were analyzed through field investigation, laboratory test and data processing methods. We arguued that poor engineering geological conditions and deep pressure increases were the main factors, and the deformation mechanism was mainly the ground deformation pressure. Second, the gray correlation theory was used to construct supporting optimization decision method in the deep roadway. This method more comprehensively considers various factors, including construction, costs, and supporting material functions. The combined support with pre-stressed anchor cables, shotcrete layer, bolt and metal net was put forward according to the actual roadway engineering characteristics. Finally, 4 support schemes were put forward for new roadways. The gray relational theory was applied to optimizing the supporting method, undertaking technical and economic comparison to obtain the correlation degree, and accordingly the schemes were evaluated. It was concluded as follows： the best was the flexible retaining scheme using the steel strand anchor; the second best was the one using plate anchors on the top and rigid common screw steel bolt on the two sides; the ttiird was; the rigid common screw steel bolt in full section of roadway; and the worst is the planished steel rigid support. The optimized scheme was applied to the 1000 m level of new excavation roadway. The results show that the roadway surrounding rock can reach a stable state after 5 to 6 months monitoring, with a convergence rate less than 1 mm/d.     

新化学冷却工艺提高热轧螺纹钢防锈性能

近期,中国科学院金属研究所科研人员研发了一种化学冷却工艺,优化了能够改善水冷螺纹钢表面氧化皮组成和处理液的结构化学配方,能显著提高热轧螺纹钢防锈性能。一系列大气腐蚀评价试验均表明,该化学冷却螺纹钢的防锈性能明显好于水冷螺纹钢。     

钢铁:期货推出的相关受惠分析

事件:上期所即将推出螺纹钢和线材两种钢材交易品种。点评:1、钢铁上市公司套保受惠:商品期货最主要作用不外乎是套期保值和价格发现功能,这对于钢铁上市公司规避钢材     

惊心动魄的“黑色星期四”

行情越接近疯狂,越有大量的跟风者涌入,于是市场更容易产生新的裂变,结果就上演了本周星期四的突变行情,包括铜、铝、锌、螺纹钢、大豆在内的21个品种集体跳水,一些品种盘中甚至触及跌停,市场资金流失近80亿,这样迅速爆发的极端行情,无疑给市场带来了莫大的恐慌!     

信用恐慌

正3月10日,上证指数大跌2.86%,再度跌穿2000点,大盘重回"1"时代。与此同时,大宗商品市场也遭受重创,铜、铁矿石、焦炭、螺纹钢等工业品主流品种被封于跌停板。种种迹象表明,市场对于信用违约的担忧情绪正在上升,其对于整个金融市场的影响不可忽视。超日债违约引发蝴蝶效应3月4日晚,上海超日太阳能科技股份有限公司董事会发布公告,表示2011年公司债(11超日债)第二期利息无法按期全额支付,从而正式违约。     

钢材期货跨品种套期保值的可行性分析

基于中厚板价格与螺纹钢价格之间的高度相关性,利用螺纹钢期货对企业采购的中厚板进行跨品种套期保值具有一定的可行性;并且模拟方案显示,利用钢材期货进行跨品种套期保值交易的效果很好。但是在取得较好效果的同时,企业也应该注意到跨品种套期保值的主要风险并做好应对政策。     

螺纹钢管在冬季排水工程中的应用

厚镀锌螺纹钢管是一种新型的排水管道材料,它卓越的防腐蚀性能和良好的耐候性能已经得到排水行业的认可,它方便的运输和快捷的安装已被用户接受。介绍在严寒的北方冬季施工及配套辅件使用的优越性。     

八一钢铁:快速成长的西北地区“钢铁明珠”

公司是新疆唯一一家大型钢铁联合企业,是我国西北地区仅有的两个钢铁生产基地之一。公司主要从事钢铁冶炼、轧制、加工及销售,生产的钢种有普碳钢、螺纹钢、焊条钢、冷轧薄板、彩涂及镀锌板等品种,产品占据新疆市场份额的70%以上,近年来,公司产品在兰