混凝土结构裂缝成因分析及预防

分析了混凝土结构裂缝的形成原因,并对如何避免砼结构裂缝进行了探讨。     

浅谈如何提高职工队伍的技能素质

就职工教育现状以及如何提高职工技能素质两方面做了深入细致的分析和研究,并提出了一些自己的看法。     

辽西金羊盆地北票组烃源岩分布及有机质丰度

为了更好地评价金羊盆地石油地质条件，采取综合分析的方法，通过资料收集、野外实测剖面以及具有代表性岩样的采集和分析。得出如下结论。金羊盆地北票组分布广泛，是盆地主要烃源岩，为盆地油气生成提供了物质基础；北票组烃源岩属差—中等烃源岩，其有机质丰度虽然不高，但具有一定的生烃能力：金羊盆地发育的凹陷中，章吉营于—巴图营子凹陷面积最大，北票组沉积厚度大，保存条件相对较好，是找油气的最有利地带。     

Rollout及其并行求解算法在多类商品库存控制中的应用

Rollout算法是Bertsekas提出的求解马尔科夫决策过程(MDP)问题的一种仿真优化算法。文章研究Rollout算法求解多类商品库存控制问题,给出了基于性能势和神经元动态规划的Rollout优化算法。另外,为了降低运算时间,文章提出了两种Rollout并行求解算法,并讨论了这两种并行算法各自的适用场合。实验结果表明,Rollout算法能满足模型未知系统的优化要求,具有较好的并行性能。     

模拟夹层的大变形有限元等厚节理单元模型

利用大变形有限元基本理论,提出了模拟夹层的大变形有限元等厚节理单元模型,并推导了其相关的大变形有限元计算公式,解决了夹层的大变形有限元模拟计算问题.     

Large-scale complementary integrated circuits based on organic transistors

Thin-film transistors based on molecular and polymeric organic materials have been proposed for a number of applications, such as displays and radio-frequency identification tags. The main factors motivating investigations of organic transistors are their lower cost and simpler packaging, relative to conventional inorganic electronics, and their compatibility with flexible substrates. In most digital circuitry, minimal power dissipation and stability of performance against transistor parameter variations are crucial. In silicon-based microelectronics, these are achieved through the use of complementary logic-which incorporates both p- and n-type transistors-and it is therefore reasonable to suppose that adoption of such an approach with organic semiconductors will similarly result in reduced power dissipation, improved noise margins and greater operational stability. Complementary inverters and ring oscillators have already been reported. Here we show that such an approach can realize much larger scales of integration (in the present case, up to 864 transistors per circuit) and operation speeds of approximately 1 kHz in clocked sequential complementary circuits.     

邓小平的"世界历史"观念

"世界历史"观念是邓小平理论的重要历史思想基石.近代世界市场的形成,打破了各民族相互隔绝的状态,中国因固守传统丧失了迎头赶上的历史机遇;当代世界经济一体化的趋势,扩大了中国与西方世界的发展距离,社会主义初级阶段的基本国情必须在"开放的世界"中进行历史定位,改革开放是走出困境的必由之路.     

Anomalous 17O compositions in massive sulphate deposits on the Earth

The variation of delta 18O that results from nearly all physical, biological and chemical processes on the Earth is approximately twice as large as the variation of delta 17O. This so-called 'mass-dependent' fractionation is well documented in terrestrial minerals. Evidence for 'mass-independent' fractionation (delta 17O = delta 17O-0.52 delta 18O), where deviation from this tight relationship occurs, has so far been found only in meteoritic material and a few terrestrial atmospheric substances. In the rock record it is thought that oxygen isotopes have followed a mass-dependent relationship for at least the past 3.7 billion years, and no exception to this has been encountered for terrestrial solids. Here, however, we report oxygen-isotope values of two massive sulphate mineral deposits, which formed in surface environments on the Earth but show large isotopic anomalies (delta 17O up to 4.6%). These massive sulphate deposits are gypcretes from the central Namib Desert and the sulphate-bearing Miocene volcanic ash-beds in North America. The source of this isotope anomaly might be related to sulphur oxidation reactions in the atmosphere and therefore enable tracing of such oxidation. These findings also support the possibility of a chemical origin of variable isotope anomalies on other planets, such as Mars.     

Design and Implementation of File Access and Control System Based on Dynamic Web

0 IntroductionComputer Aided Design (CAD) is popular nowadays .However ,it still has some disadvantages suchthat doc-uments can not be managedin a reasonable way and data cannot be saved permanently.These disadvantages makeitincon-venient to review the historical information. Some exitingproblems are as follows .① Lack of Document ManagementSystem. An enterprise will have lots of documents such asCADdrawings about its products .But ,CADsoftware cannotmanage them properly, especially wh…     

含Fe-Mo-B预合金粉铁基合金的温压成形与液相烧结

研究了含Fe-Mo-B预合金粉的铁基合金的温压和液相烧结行为,分析了成形温度和压制压力对压坯密度的影响,对比了不同Fe-Mo-B预合金粉含量下烧结前后试样的密度和显微组织. 结果表明:与常温成形相比,温压能够明显提高压坯密度,在120℃时含10%和15.4% Fe-Mo-B预合金粉的压坯密度分别提高0.34g·cm-3和0.32g·cm-3;混合粉中加入一定量的Fe-Mo-B预合金粉,压坯烧结时可形成液相烧结,促进材料的致密化,密度最大可达7.49g·cm-3,其相对密度为97.74%,并可获得典型的贝氏体组织.