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91.
PLC控制的教学机械手 总被引:2,自引:0,他引:2
张建文 《华东地质学院学报》2001,24(3):237-241
介绍一台可编程控制器(PLC)教学机械手的研制。它是一个水平/垂直位移的机械设备,用来将工件由左工作台搬到右工作台,在PLC控制下可实现手动及自动等多种工作方式,为学习PLC的原理及应用提供一种理想的示教装置。 相似文献
92.
面对连云港市新浦区软土地基上施工的某住宅楼 ,施工时由于对北楼部分桩出现的缩颈及断裂未能妥善处理 ,造成楼房北倾的问题。经协商 ,及时采取了旋喷桩加固法加固北楼基础 :采用沉降法(切桩 )、纠偏 (使各承台均匀、协调、沉降 )、接桩、固封等措施 ,效果良好。 相似文献
93.
面对资源、环境、人口、地质灾害等人类的生产、生活乃至生存的严峻危机,需要我们掌握地球内部的客观规律,不断更新和寻找地球科学理论和新的思维方式,掌握地球科学发展趋势,以协调好人与自然、人地关系及社会经济和可持续发展理论,造福于人类。 相似文献
94.
Considering the fact that there is only one pair of fixed potential poles in one direction used to monitor the resistivity
changes under the observatory station which may indicate process of earthquake preparation, based on the precondition that
the resistivity structure is 1-dimensional under the observatory station, and by way of equivalent model put forward by the
authors, this paper suggests a kind of method trying to separate the resistivity changes in deep layers from that of the shallow
layer. Analysis shows that, to obtain the same measured data with the same array, any a multi-layered geo-electrical structure
can be equivalently taken as a two-layered one, we call it equivalent model. In this paper, the resistivity and thickness
of the upper layer of the equivalent model are equal to that of the first layer of the original one, the resistivity of the
lower layer of the equivalent model is obtained with calculation according to the requirement of equivalence, its value is
relevant with the resistivities and thicknesses of all layer of the original model except for the first one, so the resistivity
change of the equivalent layer can indicate the synthetic effect of variation of all layers of the original model except for
the first one. The primary research results show that this method can work well.
Foundation item: Chinese Joint Seismological Science Foundation (100146). 相似文献
95.
An integrated geophysical survey which combines vertical seismic profile method, shallow reflection seismic method, electric
sounding, soil temperature measurement and radioactive gas measurement was used to investigate Zhaoshuling landslide in the
new site of Badong County and to assess the stability of the landslide. By rational use of these methods together with borehole
geological profile and other geological information, the spatial distribution of the landslide body, the formations and structures
within and without the landslide body were determined and the stability of the landslide was also assessed, thus making great
contribution to the successful and rational investigation and assessment of the landslide. 相似文献
96.
通过某工业城市大型一级导线网观测成果的限差检验、观测数据处理,探讨导线网平差时、,边、角验权的合理选择和匹配,及其对平差结果的精度影响,从中得出一些认识和有益的经验。 相似文献
97.
Free cupric ion concentrations and Cu complexation in selected Swiss lakes and rivers 总被引:1,自引:0,他引:1
Hanbin Xue Andrea Oestreich David Kistler Laura Sigg 《Aquatic Sciences - Research Across Boundaries》1996,58(1):69-87
[Cu2+] and Cu complexation parameters in some selected freshwater systems in Switzerland were determined by the technique of ligand-exchange and DPCSV. Results from the water columns of some eutrophic and oligotrophic lakes are presented and compared to small acid lakes. Cu is strongly complexed by organic ligands which with very high stability constants at low concentrations are probably biologically produced, as indicated by the seasonal variations in the eutrophic lakes and by the relationship between Cu complexation and algal activity in the eutrophic (pCu=15–16), oligotrophic (pCu=13–14) and acidic (pCu=9–10) lakes. The extent of Cu complexation in river waters was generally lower than in the eutrophic lakes, at similar DOC levels. No obvious correlation between Cu complexation and DOC was observed, indicating that Cu complexing ligands are specific organic compounds. 相似文献
98.
用中国科学院大气物理研究所高分辨率、自由表面热带海洋环流模式对厄尼诺/南方涛动(El/Southern Oscillation)循环中另一重要位相La Niña事件进行了数值模拟研究。模式区域为南北纬30°之间的热带太平洋,经纬圈水平方向分辨率分别为2°和1°,垂直方向分为不等距的14层;模式中考虑了盐度并引入与洋流切变和层结稳定度有关的垂直扩散参数化方案。在观测到的海表风应力、热量和淡水通量(蒸发与降水之差)驱动下,所发展的模式从1984年积分到1989年。本文给出模式对近十几年来最强的1988年La Niña事件进行数值模拟的结果,着重分析La Niña期间热带太平洋海面起伏、流场和温度场时空演变,以及La Niña和El期间变量场时空结构差别。文中还进行了模式结果和一些观测资料间的比较。 相似文献
99.
100.
In this paper we describe the transport of pollution in groundwater in the neighbourhood of a well in a uniform background flow. We compute the rate at which contaminated particles reach the well as a function of the place of the source of pollution. The motion of a particle in a dispersive flow is seen as a random walk process. The Fokker-Planck equation for the random motion of a particle is transformed using the complex potential for the advective flow field. The resulting equation is solved asymptotically after a stretching transformation. Finally, the analytical solution is compared with results from Monte Carlo simulations with the random walk model. The method can be extended to arbitrary flow fields. Then by a numerical coordinate transformation the analytical results can still be employed. 相似文献