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排序方式: 共有797条查询结果,搜索用时 15 毫秒
1.
该文分析了应用袋装炸药装填水孔爆破产生拒爆、"冲天炮"、根底偏高和爆破效果差等问题,然而应用乳化炸药混装车装填水孔可以解决这些问题,并且爆破后具有根底平整、大块率低、毒气少和综合效益高等优点.以三峡永久船闸旁侧泄水箱涵工程和江苏田湾核电站工程为例进行了分析. 相似文献
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B 炸药中绝热剪切带形成机理的细观研究 总被引:1,自引:0,他引:1
通过对快速加载后Comp.药柱剖面的扫描电镜和光学显微镜观察分析,对Comp.B炸药在快速加载下剪切带形成机理的微观机制有了初步的认识。文中采用形变试样的剖面观察分析方法,针对固体药柱这种比较软的材料,如何进行磨样、抛光、浸蚀,作了一些尝试和探索,总结出一套有效的实施办法。对不同加载速率条件下受压缩的药柱中细观组织进行了观察、分析、比较,首次给出国产Comp.B炸药装药的原始细观组织形貌,以及快速加载后药柱中细观组织形貌。经过分析,得到冲击载荷下炸药装药中绝热剪切带形成、发展的定性认识,为分析Comp.B炸药装药受冲击载荷时热点形成机理提供了一些有益的实验依据。 相似文献
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NC74-1型氨合成催化剂的升温还原及应用 总被引:1,自引:0,他引:1
介绍了NC74-1氨合成催化剂在山东华鲁恒升化工股份有限公司大氮肥氨合成的装填、升温还原及使用情况。 相似文献
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数据集市技术浅析 总被引:1,自引:0,他引:1
文笃石 《西安邮电学院学报》2009,14(5):90-92
数据集市是当前数据仓库建设的重要环节,本文通过对目前某电信的数据现状进行分析,给出了两种数据集市的建设方案,并分别对两种方案特点进行了描述。解决了电信所遇到的数据问题。 相似文献
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介绍了一种自行设计的用于高速齿轮试验台的新型液压加载装置,阐明了该装置的结构及工作原理.对影响加载装置的转矩和效率的几个主要参数进行了公式推导和分析. 相似文献
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台风对大坝的作用包括台风引起的强降雨对大坝的影响、台风引起的库水位波动(波浪)对大坝的影响以及台风风荷载对大坝的影响等。基于加卸载响应比理论,通过对台风作用下的大坝效应增强和维持判据进行深入研究,提出了库水位加卸载响应比和波浪加卸载响应比的计算方法,给出了台风作用下大坝效应增强与维持判据的评判准则。利用上述方法和评价准则,对受2010年10号台风"莫兰蒂"影响的东坞水库进行分析,结果表明,东坞水库大坝受台风影响不大,大坝处于稳定状态。将加卸载响应比理论引入到水利工程领域,是对加卸载响应比理论的应用范围的拓展,也是研究台风作用下大坝稳定性的新思路。 相似文献
8.
《Ergonomics》2012,55(7):685-695
This study investigated the contribution of soft tissue deformation below the sacrum (S) and vertical spinal creep to total height loss (THL) measured in sitting. Eight asymptomatic subjects (four males, four females) aged between 21 and 51 years were measured. Simultaneous measurement of THL and S were commenced after the subjects had been sitting for 5 min. THL was recorded while subjects were positioned in a seated stadiometer, which controlled their spinal posture. S was measured by placing an ultrasound transducer at the level of the top of the subject's sacrum. Over 25 min of sitting with loaded and unloaded interventions applied to their spine, different response characteristics between S and THL were noted. This study demonstrated that soft tissues below the sacrum could contribute up to 30% on average of total height loss. This suggests that researchers should take into account the soft tissue deformation outside the spine when studying vertical creep in sitting. 相似文献
9.
《Ergonomics》2012,55(10):1361-1371
The coefficient of rolling resistance (C r) for pneumatic tyres is dependent on hysteresis loss from tyre deformation which is affected by the vertical force applied to the tyres (F v) and the tyre inflation pressure (P r). The purpose of this paper was to determine the relative influence of five different levels of P r and four different levels of F v on C r and to examine the relationships of C r with P r and F v during cycling locomotion. F v was modified through carriage of additional mass by the subject. C r was determined with the coasting deceleration method from measurements performed in a level hallway. Iterations minimizing the sum of the squared difference between the actual deceleration distance and a predicted deceleration distance were used to determine C r. This latter distance was computed from a derivation based on Newton's second law applied to the forces opposing motion. C r was described by a hyperbolic function of P r (C r = 0.1071 P r ?0.477, r 2 = 0.99, p < 0.05), decreasing 62.4% from 150 kPa (Cr= 0.0101) to 1200 kPa (Cr = 0.0038). F v was related to C r by a polynomial function (C r = 1.92.10?8 F v 2 ?2.86.10?5 F v + 0.0142, r 2 = 0.99, p = 0.084), with an added mass of 15 kg (C r = 0.0040) resulting in an 11.4% increase in C r compared with no added mass (C r = 0.0035). From this study, it is concluded that the relationships of P r and F v with C r for cycling are non-linear. Furthermore, a simulation model shows that changes in P r and F v of the magnitude examined here have an important effect on competitive cycling performance. 相似文献
10.
H. Helminen E. Juntura J. Koponen P. Laihonen H. Ylinen 《Environmental Modelling & Software》1998,13(5-6)
Nutrient concentrations have increased in the Archipelago Sea during recent years. This is probably caused by growth in the loads from agriculture, air, fish farming and the Baltic proper. The Archipelago Sea acts like a nutrient filter between the Baltic proper and the Bothnian Sea; part of some of the externally input nutrients are retained within this area. Previously only rough estimates of the amount of the background load have been given. In this study the amount of net nutrient inflow from the Baltic proper was estimated with the aid of a three-dimensional hydrodynamic model for the years 1993–1997. Our model suggests that the role of background nutrient load from the Baltic proper may sometimes be decisive in the eutrophication process. For example, in June 1993 the background load of phosphorus was 300 000 kg in one month, i.e. about threefold compared to the total phosphorus load from fish farming during this whole year. Nutrient inflow varies a lot during open water seasons and therefore more detailed studies are highly recommended. If all other local loading sources were included in the dynamic nutrient balance model we could calculate actual nutrient concentrations at any given time in the Archipelago Sea. 相似文献