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研究了堆载预压法加固软土地基的过程中地下水浸没作用对预压荷载的减小情况,给出了深圳蛇口地区堆载预压加固地基过程中荷载的变化规律,利用大、小应变条件下的固结沉降计算公式对几种工况下的计算结果进行了对比分析.结果说明,考虑地下水浸没作用对地基固结沉降的影响随荷载和土压缩性以及土层厚度的增加而增大.通过与传统计算方法的比较,表明进行大变形分析时预压荷载的变化对最终沉降量有显著影响. 相似文献
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Reactive Materials (RMs), a new material with structural and energy release characteristics under shock-induced chemical reactions, are promising in extensive applications in national defense and military fields. They can increase the lethality of warheads due to their dual functionality. This paper focuses on the energy release characteristics of RM casings prepared by alloy melting and casting process under explosive loading. Explosion experiments of RM and conventional 2A12 aluminum alloy casings were conducted in free field to capture the explosive fireballs, temperature distribution, peak overpressure of the air shock wave and the fracture morphology of fragments of reactive material (RM) warhead casings by using high-speed camera, infrared thermal imager temperature and peak overpressure testing and scanning electron microscope. Results showed that an increase of both the fireball temperature and air shock wave were observed in all RM casings compared to conventional 2A12 aluminum ally casings. The RM casings can improve the peak overpressure of the air shock wave under explosion loading, though the results are different with different charge ratios. According to the energy release characteristics of the RM, increasing the thickness of RM casings will increase the peak overpressure of the near-field air shock wave, while reducing the thickness will increase the peak overpressure of the far-field air shock wave. 相似文献
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We seek dynamic server assignment policies in finite‐capacity queueing systems with flexible and collaborative servers, which involve an assembly and/or a disassembly operation. The objective is to maximize the steady‐state throughput. We completely characterize the optimal policy for a Markovian system with two servers, two feeder stations, and instantaneous assembly and disassembly operations. This optimal policy allocates one server per station unless one of the stations is blocked, in which case both servers work at the unblocked station. For Markovian systems with three stations and instantaneous assembly and/or disassembly operations, we consider similar policies that move a server away from his/her “primary” station only when that station is blocked or starving. We determine the optimal assignment of each server whose primary station is blocked or starving in systems with three stations and zero buffers, by formulating the problem as a Markov decision process. Using this optimal assignment, we develop heuristic policies for systems with three or more stations and positive buffers, and show by means of a numerical study that these policies provide near‐optimal throughput. Furthermore, our numerical study shows that these policies developed for assembly‐type systems also work well in tandem systems. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008 相似文献
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本文研究了二甲基硅二苯基硅共聚物(P(DMS-CO-DPS))的紫外光谱。文中得到了共聚物主链Si-Si 链最大紫外吸收波长及摩尔吸收系数与其分子量的定量关系;发现共聚物在高浓度(约大于0.03g/1)的条件下,在λ=325nm 处有一位置不变,吸收大小与共聚物分子量、浓度有关的吸收。 相似文献
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本文研究了用二甲基二氯硅烷和二苯基二氯硅烷的混合物与金属钠反应,制取可溶性的二甲基硅二苯基硅共聚物。结果表明:共聚物产率随两单体配比的接近而增大,分子量随二苯基二氯硅烷含量的增大而减小;单体配比相近时,反应时间基本上不影响共聚物的分子量硬组成含量,但在反应初期共聚物产率随时间而增加;反应温度对共聚物产率、分子量基本上无影响;共聚物呈无定型非晶态结构。 相似文献
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可编程控制器直流调速系统通信监控 总被引：2，自引：0，他引：2
研究了 Ｓ Ｉ Ｅ Ｍ Ｅ Ｎ Ｓ可编程控制器与具有通信功能的直流调速器之间的通信控制,通过对系统的硬件配置、控制方式、通信软件实现介绍,给出了应用 Ｐ Ｌ Ｃ进行直流调速器串行通信监控的方法。 相似文献
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An important aspect of supply chain management is dealing with demand and supply uncertainty. The uncertainty of future supply can be reduced if a company is able to obtain advance capacity information (ACI) about future supply/production capacity availability from its supplier. We address a periodic‐review inventory system under stochastic demand and stochastic limited supply, for which ACI is available. We show that the optimal ordering policy is a state‐dependent base‐stock policy characterized by a base‐stock level that is a function of ACI. We establish a link with inventory models that use advance demand information (ADI) by developing a capacitated inventory system with ADI, and we show that equivalence can only be set under a very specific and restrictive assumption, implying that ADI insights will not necessarily hold in the ACI environment. Our numerical results reveal several managerial insights. In particular, we show that ACI is most beneficial when there is sufficient flexibility to react to anticipated demand and supply capacity mismatches. Further, most of the benefits can be achieved with only limited future visibility. We also show that the system parameters affecting the value of ACI interact in a complex way and therefore need to be considered in an integrated manner. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011 相似文献
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以超短波潜对岸通信和超长波岸对潜通信为基础,概述了激光通信的发展、激光传输的特性、激光器件特性和接收滤光器特性及其发展动向。 相似文献