沿空留巷合理支护和卸压保护的研究

本文在总结国内外沿空留巷所取得经验和成果的基础上,主要研究了沿空留巷的合理支护和沿空留巷的卸压保护。推导出了中等稳定顶板条件下计算支护系统所需阻力和可缩量的公式,并进行了相应的模拟实验研究。运用非线性有限元法和相似模拟实验对留巷卸压进行了探讨。     

人防工程消防电气设计的探讨

论述了人防工程主要用电设备及其运行特点 ,并对其消防电源的配置和火灾自动报警系统进行了分析研究 ,提出了具体的技术性措施。     

"后姚明时代"中国男篮发展对策研究——对第25届亚锦赛中国男篮攻防能力的分析

采用文献资料、录像观察、数据统计、逻辑分析等方法,对第25届亚锦赛中国男篮的攻防能力进行了研究,研究结果认为:新一届中国男篮存在防守质量差、篮板球保护意识淡薄、身体对抗下投篮命中率低、后卫线队员能力不足等诸多问题.针对上述问题,提出了强化篮板球意识、提高队员身体对抗能力、重视优秀后卫队员和年轻队员的培养、加强中外高水平...     

北京电网集控型防误系统建设研究

本文针对北京电网集控站现有运行模式,提出北京电网集控型防误系统建设方案,对集控型防误系统建设需求作了详细分析,提出了北京电网集控型防误系统所需特点,重点讨论了集控站防误系统建设方案中的组网模式、五防操作模式以及防误系统功能的设计方案,为保证北京电网电力设备的安全稳定运行提供了思路。     

Natural history of an ant–plant–butterfly interaction in a Neotropical savanna

Non-myrmecophilous lepidopteran larvae using plants bearing ant attractants such as extrafloral nectaries are good models for studying morphological and behavioural mechanisms against ant predation. Udranomia spitzi (Hesperiidae) is a butterfly whose larvae feed on leaves of Ouratea spectabilis (Ochnaceae), a plant with extrafloral nectaries. We described the early stages of U. spitzi, and used field observations and experiments to investigate the defensive strategies of caterpillars against predatory ants. Larvae pass through five instars and pupation occurs inside larval leaf shelters. Ant-exclusion experiments revealed that the presence of ants did not affect significantly caterpillar survival. Predation experiments showed that vulnerability to ant predation decreased with increase in larval size. The present study showed that predatory ants are not as relevant as demonstrated for other systems, and also illustrates how observational data and field experiments can contribute to a better understanding of the biology and ecology of a species of interest.     

Size,spines and crochets: defences of luna moth caterpillars against predation by brown anoles

Field-testing predator-prey interactions between invasive exotic brown anole lizards and sentinel larvae of the luna moth, Actias luna, suggests that late instars of this saturniid, and perhaps many other saturniids, are well defended by their spines and crochets against predation by lizards. However, Actias luna larvae remain vulnerable to anole predation until they reach about 3 cm in length. In contrast, even relatively small caterpillars that are chemically defended, such as those of the io moth, Automeris io, and the monarch butterfly, Danaus plexippus, were shown to be well defended against anoles by their toxins. There is an obvious advantage for caterpillars to be chemically defended. However, there is also a tradeoff: Danaus plexippus are restricted to feeding on a relatively small group of plants, which limits resources and requires specialisation; in polyphagous Automeris io, the constant production of elaborate spines and toxin leads to prolonged larval development, which is at least twice as long as that of Actias luna, and exposes the caterpillars to mortality factors such as parasitism for a longer duration.     

高校图书馆馆员权利及其维护

高校图书馆馆员除理应享有宪法及法律法规赋予的权利外,还应当享有与其工作密切相关的权利。但是我国高校图书馆馆员权利现状很不理想。维护图书馆馆员权利应当加强图书馆民主管理制度建设,馆员自身的法律意识和信息育人的形象意识。     

灰色理论在确定防空导弹武器系统经济寿命中的应用

针对使用保障费用数据有限的防空导弹武器系统经济寿命的确定问题，根据灰色理论建立了预测模型，并用该方法预测了某一设备的经济寿命，分析结果令人满意。     

略论假想防卫及其过当

大陆法系对属于违法性阻却事由的错误的假想防卫及其过当存在着极为复杂的理论和激烈的争论,属于事实错误的假想防卫只可能是疏忽大意的过失犯罪或者意外事件,而行为人对其过当部分也正如对防卫过当一样不可能存在故意。     

既有暗挖区间扩挖优化技术分析

介绍了北京地铁10号线太阳宫站～三元桥站区间既有矿山法暗挖隧道扩挖为人防段的2种施工方案,在分析了原设计方案9导洞扩挖的优缺点的基础上,提出了"十字撑4导洞"的优化方案,该方案将既有暗挖区间内的十字内撑逐步转换为人防扩挖段初衬的中隔墙与中隔壁,避免了大量的破除工作,将9导洞暗挖施工转换为了4导洞施工,大大缩短了施工工期,降低了工程总体造价.并将原设计人防段由矩形形式变换为马蹄形形式,结构受力更加合理.