机载粉剂催化剂播撒设备的研制及其在奥运和残奥消云中的应用     

金华  张蔷  何晖  马新成  黄梦宇  田海军  刘力威 《气象》2012,38(11):1443-1448

人为引发的下沉气流可以抑制对流云的发展,这一现象已在试验中得到验证。用“人工下沉气流法”实施人工消云试验时,需在云顶大剂量的播撒粉剂催化剂。北京市人工影响天气办公室研制了能完成此类大剂量播撤任务的设备,并通过外场飞行试验对设备进行检验和改进。这是国内人工影响天气领域首个采用空投播撒法的粉剂催化剂播撤设备;可减少催化剂对飞机和播撤设备的污染。分析发现,新设备能够满足人工消云作业中播撒大剂量粉剂催化剂的需要。该设备在北京奥运会、残奥会开闭幕式当日的消云试验作业中投入使用,共实施消云飞行作业9架次,累计利用新设备播撒吸湿性粉剂催化剂34吨。  相似文献   

野外组装可移动式防直击雷装置的研究   总被引：1，自引：1，他引：0  

高燚  潘家利  石保平 《气象研究与应用》2008,29(3):55-57

通过对9m×9m的实际接地网进行计算,对于二类和三类防雷建筑物,可以应用当环形接地网的等效面积大于78.5m2后,采取不计接地网接地电阻的设计方法来实现野外可移动式接地网设计,并将避雷针和避雷线组合的接闪器设计成标构件,方便组装,实现野外组装可移动式防直击雷装置.  相似文献   

Modifications of resonant column and torsional shear device for the large strain     

Yoon-Shin Bae  James A. Bay 《Computers and Geotechnics》2009

Conventional RC/TS (resonant column and torsional shear) devices use a specimen with an aspect ratio (height-to-diameter) of 2:1 and this generates a maximum shear strain in the sample of about 1.5% at the maximum rotation of the driving system. The objective of this study is to modify the RC/TS device to generate higher strain amplitude. The modifications include a new base pedestal to overcome the limitations in the travel of the drive system and modification of the coil wiring to increase torque. The effects of the new coil wire on torque in the electromagnetic drive system were evaluated and the application of the modified device was illustrated using sand soil.  相似文献   

Stress Measurement by Overcoring at Shallow Depths in a Rock Slope: the Scattering of Input Data and Results   总被引：1，自引：0，他引：1  

C. Clément  V. Merrien-Soukatchoff  C. Dünner  Y. Gunzburger 《Rock Mechanics and Rock Engineering》2009,42(4):585-609

This paper describes a field experiment of stress measurement using the overcoring method performed in a rock slope, called Rochers de Valabres (located in France’s Southern Alps Region), a field laboratory site prone to rockfalls. Six measurements were conducted at shallow depths from the surface, moving deeper along a sub-horizontal borehole. The experiment was conducted in heterogeneous and anisotropic gneiss, with the overcored rock elastic properties, as evaluated by biaxial and uniaxial tests, being widely scattered. Since stress calculations are sensitive to all input data uncertainties, strain inversion was, thus, performed using an experimental device and Monte Carlo simulations. The experimental device allows the assessment of rather broad confidence intervals for both stress magnitude and orientation. The results indicate that the stress state in the surface area is quite heterogeneous and may be correlated with topography. The measurements show a nonlinear stress distribution with distance to the free surface, along with high values of principal stresses, despite the vicinity of the surface. Although influenced by local topography, orientations of the principal computed stresses are characterized by a high turnover due to local heterogeneities. The results are roughly in accordance to a 2D finite element model of the site.  相似文献   

分体式不提钻钻孔压水试验孔口装置的研发与应用          下载免费PDF全文

聂新明 《探矿工程》2019,46(3):51-56

在钻探施工过程中,由于工程要求,必须对钻孔做孔口压水试验,根据钻孔吸水量、压力数据,检验钻孔的漏失及其他情况。传统孔口压水试验使用的孔口装置,必须把孔内钻具提出孔外,严重地影响工程施工进度。分体式不提钻钻孔压水试验孔口装置的研发,可在不提钻的情况下完成孔口压水试验作业,大幅度缩短施工工期,减轻工人的劳动强度,减少安全事故的发生,对钻探工程施工具有一定的经济价值和现实意义。本文详细介绍了研制的分体式不提钻钻孔压水试验孔口装置的结构、工作原理及使用方法,并与传统孔口压水装置进行了试验对比,验证了分体式不提钻孔口压水试验孔口装置工作的可靠性及优势。  相似文献   

日照黄海海域冷水团勘察工程施工工艺探究          下载免费PDF全文

张辉 《探矿工程》2019,46(5):52-57

日照万泽丰渔业有限公司黄海冷水团优质鱼类绿色养殖项目是山东省首批公布的新旧动能转换重大项目,规划海域面积20 km2。工程勘察是工程建设项目首先开展的基础性工作,是项目选址、设计和施工的重要依据。本文通过有效盘活有限资源,科学论证、严谨施工,创新钻探船改造、重力导向装置实现深海套管安放,成功实施了该项目的工程勘察工作,为远海深水勘察施工提供了经验。  相似文献   

Predicting the visualization intensity for interactive spatio-temporal visual analytics: a data-driven view-dependent approach     

Jing Li  Tong Zhang  Qing Liu  Manzhu Yu 《International journal of geographical information science》2017,31(1):168-189

The continually increasing size of geospatial data sets poses a computational challenge when conducting interactive visual analytics using conventional desktop-based visualization tools. In recent decades, improvements in parallel visualization using state-of-the-art computing techniques have significantly enhanced our capacity to analyse massive geospatial data sets. However, only a few strategies have been developed to maximize the utilization of parallel computing resources to support interactive visualization. In particular, an efficient visualization intensity prediction component is lacking from most existing parallel visualization frameworks. In this study, we propose a data-driven view-dependent visualization intensity prediction method, which can dynamically predict the visualization intensity based on the distribution patterns of spatio-temporal data. The predicted results are used to schedule the allocation of visualization tasks. We integrated this strategy with a parallel visualization system deployed in a compute unified device architecture (CUDA)-enabled graphical processing units (GPUs) cloud. To evaluate the flexibility of this strategy, we performed experiments using dust storm data sets produced from a regional climate model. The results of the experiments showed that the proposed method yields stable and accurate prediction results with acceptable computational overheads under different types of interactive visualization operations. The results also showed that our strategy improves the overall visualization efficiency by incorporating intensity-based scheduling.  相似文献   

数字化地震观测及技术系统建设若干问题   总被引：1，自引：0，他引：1  

宋臣田  姜捷  赵仲和 《地震地磁观测与研究》1999,20(6):54-59

首先论述了数字地震台网的基本特点和优点,然后着重论述数字地震台网技术系统建设中的若干问题,包括台址的选择,拾振器,采集器,传输信道和无线数字传输设备的选择和安装,以及系统安装中的总体技术要求等。  相似文献   

基于GPS-RTK技术的波浪能发电装置结构动态位移监测及滤波方法          下载免费PDF全文

郭欣然  陶涛  杨毅  刘石 《海洋技术学报》2023,(4):51-59

利用全球定位系统实时差分技术（Global Positioning System Real-Time Kinematic,GPS-RTK）对波浪能发电装置进行结构变形监测得到的信号会存在噪声。针对这个问题,本文提出一种结合巴特沃斯（Butterworth）滤波器和自相关函数经验模态分解（Empirical Mode Decomposition,EMD）的滤波降噪算法,利用动态位移仿真信号进行了实验验证。结果表明：该滤波算法能够有效降低装置动态位移监测数据中噪声的影响,利用滤波算法对仿真信号进行降噪处理之后,可以提取出信号中包含的结构固有频率。  相似文献   

Reduction of pounding effects in elevated bridges during earthquakes     

Robert Jankowski  Krzysztof Wilde  Yozo Fujino 《地震工程与结构动力学》2000,29(2):195-212

Pounding of adjacent superstructure segments in elevated bridges during severe earthquakes can result in significant structural damage. The aim of this paper is to analyse several methods of reduction of the negative effects of collisions induced by the seismic wave propagation effect. The analysis is conducted on a detailed three‐dimensional structural component model of an isolated highway bridge. The results show that the influence of pounding on the structural response is significant in the longitudinal direction of the bridge and significantly depends on the gap size between superstructure segments. The smallest response can be obtained for very small gap sizes and for gap sizes large enough to prevent pounding. Further analysis indicates that the bridge behaviour can be effectively improved by placing hard rubber bumpers between segments and by stiff linking the segments one with another. The experimental results show that, for the practical application of such connectors, shock transmission units can be used. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献