轧制道次间插入冷却对特厚钢板组织与性能的影响

使用实验轧机旁冷却装置配合轧机进行轧制实验，研究轧制道次间不同冷却工艺对特厚钢板组织和性能的影响规律.研究结果表明:采用道次间冷却工艺可以在全厚度方向获得组织细化及强韧性提高效果，采用强冷道次间冷却实验钢1/4处晶粒尺寸可细化至10μm，强度为376MPa，-40℃冲击功为169J;心部晶粒尺寸可细化至15μm，强度为360MPa，-40℃冲击功为123J.本工艺可形成470μm厚表层细晶层，晶粒尺寸可细化至5μm;粗轧道次间插入冷却工艺轧制钢板强度和冲击韧性优于中间坯冷却工艺;随冷却强度增加，钢板内部组织明显细化且强度大幅提高.     

Innovation on Petroleum Engineering Technology of China Beach and Shallow Water Areas

1Chinaoffshoreoil&gasresourcesandtheircharacteristicfeatures　Chinaoffshoreoil&gasexplorationstartedduringthe1 95 0s .Until 1 971 ,thecommercialHai 4fieldwasfoundinBohai.Subsequentlytwoproductionplatformswereconstruc ted ,thefirstChinaoffshoreoilfieldwasformed .Fromthenon ,Chinaoffshoreoil&gasexplorationandexploitationspeedbecameprogressivelyfaster.Afteralargeamountofexplorationwork ,theoilandgasresourcesinChinacoastalareasweremadeclearpreliminarily .AccordingtoState sSecondaryResourceEva…     

标准贯入与波速在原位测试中的对比分析

标准贯入与波速测试在工程勘察中都是较重要的原位测试手段,应用广泛。通过对芜湖城南某地块分别利用标准贯入试验和单孔波速测试法进行原位测试试验结果的分析,说明在工程勘察及成果运用中,应综合考虑多种因素,合理采用有关参数。     

恢复坎儿井输水系统功在当代利在千秋

文章简述了坎儿井输水系统的优缺点，及在干旱地区农业发展中的重要作用。要恢复、发展坎儿井输水系统，全面认识到坎儿井输水系统在新疆干旱区绿洲农业发展中的重要意义。     

浅埋煤层开采中的溃沙灾害研究

分析了浅埋煤层开采的水文条件和工程地质条件，得出了浅埋煤层发生渍沙灾害必须具备的4个条件；根据浅埋煤层中组合关键层的一些参数分析了老顶破断岩块的运动规律，判断了浅埋煤层开采中岩块是否发生回转失稳，探讨了岩块回转触矸后发生滑落失稳的可能性，计算了断裂岩块端角接触面高度，得出了满足裂隙滤沙的合理端角接触面高度；大柳塔1203工作面开采只发生了涌水而未溃沙，这和理论计算的结论基本一致．参8．     

Critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau

Scientific evidence for the upper limit of farmland is proposed. Shallow gully erosion is one of erosion types distributed extensively on sloping farmland in the hilly regions of the Loess Plateau. Field observation and aerial photos interpretation, as well as laboratory experiments show that the shallow gully erosion occurring on the steeper farmland in the hilly regions of the Loess Plateau is an important factor leading to intensive erosion on slope, because of its extensive distribution and intensive runoff collection. The data on the formation, development and distribution of shallow gullies on sloping farmland indicate that critical slope gradient for shallow gully initiation ranges from 15 to 20 degrees with an average of 18.2 degrees. Therefore, it is suggested that critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau should be kept within the critical slope gradient for shallow gully initiation to prevent shallow gully formation in order to control soil loss more effectively. But as the first step, the cultivation on the slopes with slope larger than 25 degrees where the maximum erosion occurs should be strictly forbidden.     

木兰溪两岸浅井水对紫露草四分体微核率的影响

采用紫露草四分体微核技术,对莆田木兰溪下游河溪水和饮用的浅井水进行致突变性监测。结果表明,１０份河溪水能明显诱发紫露草四分体微核率的增高;与对照组相比１０份浅井水也均不同程度提高了四分体微核效应,８份已达到显著或极显著水平（Ｐ〈０．０５或Ｐ〈０．０１）,且与诱发的紫竹梅四分体微核效应显著相关,ｒ＝０．９７７７。说明浅井水内存在致植物细胞染色体畸变物质,提示当地居民上消化道肿瘤高发与饮水污染有一定相     

大柳塔煤矿12305工作面覆岩活动规律的相似模拟

为了研究薄基岩浅埋煤层开采过程中覆岩活动规律,利用相似材料模型法,对大柳塔煤矿12305工作面进行了相似模拟实验,得出了薄基岩浅埋煤层开采过程中覆岩活动特点.结果表明,薄基岩浅埋煤层开采的覆岩活动规律与常规开采顶板活动规律存在根本区别,应该有其自身的开采理论指导现场生产.     

强夯—塑料板排水法在粉土和粉质粘土地基加固中的试验研究

针对黄河中下游粉土、粉质粘土成层地基,通过插设塑料排水板和不插排水板条件下强夯对比试验研究,证实了插设塑料排水板可以有效的降低强夯时超静孔隙水压力峰值,加快其消散,缩短强夯施工工期;提高强夯夯沉,减少振动对土体的扰动,缩短触变恢复时间,因而人工塑料排水板在强夯处理此类地基中是十分有效的。