大型铸钢件操作侧机架的铸造工艺

通过多年校企合作生产实践,对大型铸钢件操作侧机架铸造工艺进行了探讨与研究.经过多次技术论证,并对铸造工艺进行计算机模拟仿真试验,以确保铸造工艺合理、可靠.最终采用大型外冷铁、配合冒口对铸件温度场进行控制,采用电弧炉、LF炉联合冶炼,以提供足够的优质钢水,确保铸件质量.此件最终经德国专家严格验收,铸件内、外质量优良,达到了大型铸钢件的设计要求.     

国产X65卷板在库鄯管道的应用

上海宝钢首次生产的Ｘ６５卷板，作为库鄯输油管道用钢哮，经制管和试验检查，钢材稳定、质量合格，完全符合ＡＰＩ５Ｌ标准，在力学性能和化学成分等方面邓国际水平，为我国高强度、高韧性的管 道用钢填补了空白。     

有机膦酸盐对碳钢在NaHCO3—Na2CO3溶液中钝化性能的影响

采用恒电位方法研究了羟基乙叉二膦酸（ＨＥＤＰ）、二乙烯三胺五甲太膦酸（ＤＥＴＰＭＰ）、三乙烯四胺六甲叉膦酸（ＴＥＴＨＭＰ）、乙二胺四叉膦酸（ＥＤＴＭＰ）对碳钢在ＮａＨＣＯ３－Ｎａ２ＣＯ３缓冲液中钝化过程破裂电位的影响，结果表明；在一定的浓度范围内，上述有机膦酸盐能促进碳钢的钝化，并能使其进入自钝化状态，但当有机磷酸盐浓度增中到一定值后，碳钢的阳极溶解电流又重新增大，有机磷酸盐对碳钢在在含Ｃｌ离子的     

一种用C18柱纯化低浓度微量寡核苷酸的新方法

通过比较4种不同的回收方法和C18硅胶4种不同的用量对回收的影响,提出了回收低浓度微量寡核苷酸的最佳方案:分别用1 mL乙腈、2 mL灭菌双蒸水和1 mL 10 mmol/L乙酸铵平衡装填10 mg硅胶的C18 Sep-Pak反相层析柱;再将寡核苷酸溶液通过C18柱;然后用1 mL 25 mmol/L碳酸氢铵洗脱C18柱,并以3000 r/m in离心2 m in;最后用1 mL 30%乙腈洗脱C18柱,将收集的溶液离心冻干后即得到纯化的寡核苷酸。该方法的回收率可达53.7%±3.0%。     

高校学报栏目设置的探讨

本文阐述了高校学报栏目的概念、特征、作用及其划分的方法，讨论了学报栏目编排时应注意的几个问题。     

DNA recovery from agarose gels with a simple centrifuge-driven sephadex filtration

Conventional methods of DNA recovery from agarose gel generally require expensive equipment, extended elution times, or considerable handling of the sample after elution. We developed a simple protocol for a quick and effective recovery of DNA from agarose gels with good yield and quality. Using a Sephadex resin filled spin column, DNA fragments of 500 bp to 6 kb in an agarose gel slice were easily recovered by a 2 min centrifugation. The recovery efficiencies were over 40%-50% and the eluted DNA can be used directly for downstream application, such as polymerase chain reactions (PCR) and restriction enzyme digestion. This method could also be used to recover large DNA fragment (48 kb) without degradation. The use of Sephadex helps to remove small molecular impurities from agarose and it also reduces the chance of clogging the column filter caused by direct contact with agarose.     

浅谈钢筋砼构造柱通病的防治

本文论述了砖混结构现浇砼构造柱质量通病的产生原因,预防措施及施工方法。     

粘钢加固技术的设计与应用

粘钢即在被加固构件表面粘贴钢板，籍以提高其承载能力，目前粘钢技术已在实际工程中得到广泛应用，技术日趋成熟，粘钢有施工简便、工期短、占用的空间小等优点；本文根据施工经验提出施工方法，以利在实际加固当中取得较好的经济效益。     

桥梁钢筋锈蚀检测

本文通过对桥梁结构物中钢筋锈蚀的分析，来评定桥梁结构中钢筋的使用状态，为准确鉴定旧桥的质量与可靠度提供技术数据。     

Prediction of the buckling stress of intermediate wooden columns using the secant modulus

We made several buckling tests of wooden columns with intermediate slenderness ratios () and examined the empirical formulas. On the basis of the examination, we formulated an equation for predicting the buckling stress () of an intermediate wooden column. Sitka spruce (Picea sitchensis Carr.) and buna (Japanese beech, Fagus crenata BI.) were used for the studies. A compressive load was applied on the specimen supported with pin ends, and the buckling stress was predicted by the tangent modulus theory and two empirical equations: those of Tetmajer and Newlin-Gahagan. The predicted - relations were compared with the test results, and the applicability of these predictions were examined. Based on the comparisons, we formulated an equation that can predict the - relations of materials with various stress-strain characters in the plastic strain range.