太阳能供电系统在天津测震台站的应用     

孙路强  栗连弟  卞真付  郭巍  柳艳丽 《地震地磁观测与研究》2014,(1):247-249

利用太阳能供电系统解决天津市部分台站无法接入交流供电的问题,对部分台供电系统进行改造,采用复合式供电模式,避免农忙或雷雨季节停电问题,以提升台网整体数据传输连续率。  相似文献   

Integrated method of RS and GPR for monitoring the changes in the soil moisture and groundwater environment due to underground coal mining   总被引：3，自引：0，他引：3  

Zhengfu Bian  Shaogang Lei  Hilary I. Inyang  Luqun Chang  Richen Zhang  Chengjun Zhou  Xiao He 《Environmental Geology》2009,57(1):131-142

Mining affects the environment in different ways depending on the physical context in which the mining occurs. In mining areas with an arid environment, mining affects plants’ growth by changing the amount of available water. This paper discusses the effects of mining on two important determinants of plant growth—soil moisture and groundwater table (GWT)—which were investigated using an integrated approach involving a field sampling investigation with remote sensing (RS) and ground-penetrating radar (GPR). To calculate and map the distribution of soil moisture for a target area, we initially analyzed four models for regression analysis between soil moisture and apparent thermal inertia and finally selected a linear model for modeling the soil moisture at a depth 10 cm; the relative error of the modeled soil moisture was about 6.3% and correlation coefficient 0.7794. A comparison of mined and unmined areas based on the results of limited field sampling tests or RS monitoring of Landsat 5-thermatic mapping (TM) data indicated that soil moisture did not undergo remarkable changes following mining. This result indicates that mining does not have an effect on soil moisture in the Shendong coal mining area. The coverage of vegetation in 2005 was compared with that in 1995 by means of the normalized difference vegetation index (NDVI) deduced from TM data, and the results showed that the coverage of vegetation in Shendong coal mining area has improved greatly since 1995 because of policy input RMB￥0.4 per ton coal production by Shendong Coal Mining Company. The factor most affected by coal mining was GWT, which dropped from a depth of 35.41 m before mining to a depth of 43.38 m after mining at the Bulianta Coal Mine based on water well measurements. Ground-penetrating radar at frequencies of 25 and 50 MHz revealed that the deepest GWT was at about 43.4 m. There was a weak water linkage between the unsaturated zone and groundwater, and the decline of water table primarily resulted from the well pumping for mining safety rather than the movement of cracking strata. This result is in agreement with the measurements of the water wells. The roots of nine typical plants in the study area were investigated. Populus was found to have the deepest root system with a depth of about 26 m. Based on an assessment of plant growth demands and the effect of mining on environmental factors, we concluded that mining will have less of an effect on plant growth at those sites where the primary GWT depth before mining was deep enough to be unavailable to plants. If the primary GWT was available for plant growth before mining, especially to those plants with deeper roots, mining will have a significant effect on the growth of plants and the mechanism of this effect will include the loss of water to roots and damage to the root system.  相似文献   

A Research on the Algorithm of Local Atomic Time     

Li Bian  Qu Li-li  Gao Yu-ping  Hu Yong-hui 《Chinese Astronomy and Astrophysics》2011,35(2):314

The goal of all time laboratories’ pursue is to produce and keep a stable, precise and reliable time scale. The long-term stability of the time scale is mainly taken into account in the traditional ALGOS algorithm, while the local atomic time scale should give consideration to both the long-term and shortterm stabilities. From the analysis and research on the atomic clock noise model and under the condition that the long-term stability of the local atomic time scale does not drop, a complete algorithm is proposed which is suitable for the calculation of the local time scale TA (NTSC) carried out at the time laboratory with the time-keeping clocks of a unitary type and being close in performance at the National Time Service Center, called the NTSC for short, of Chinese Academy of Sciences. The data of all the clocks in the NTSC which participated in the calculation of the International Atomic Time (TAI) all the year round in 2008 are applied to the test and verification of the new algorithm, with the result showing that both the short- and long-term stability indexes of the obtained TA (NTSC) are improved. The research result is suitable for the calculation of the atomic time scale of the time laboratory whose time keeping system is similar to that of the NTSC.  相似文献   

吉林西部地区高砷地下水砷的阈值分析及风险评价   总被引：1，自引：0，他引：1  

赵娟  李育松  卞建民  张丽姝  杨占梅 《吉林大学学报(地球科学版)》2013,43(1):251-258

高砷地下水导致的砷中毒是吉林西部地区近年来新发现的地方病。为评价饮用水中砷对人体健康产生的潜在危害,在野外调查、采样分析的基础上,开展了水砷安全阈值分析 ,确定了砷的总质量浓度0.05 mg/L为研究区的水砷安全阈值,建立了地下水健康风险评价模型,进行了地下水砷健康风险评价。结果表明:研究区地下水砷引起的个人年均风险度最高达2.11×10^-3 a^-1,其中高砷的第四系承压水中97.06%的采样点水砷对人体的个人年均致癌风险度,大于国际辐射防护委员会(ICRP)推荐的最大可接受值5.0×10^-5 a^-1;作为备用水源的第三系大安组、泰康组承压水69.57%采样点砷的致癌风险度也超过最大可接受风险水平。通过对风险度评价结果与砷中毒病情等资料的对比分析,风险评价结果与砷中毒病情基本一致,验证了评价结果的合理性。  相似文献   

MPLS VPN高速区域网络在天津地震监测系统中的应用.   总被引：4，自引：4，他引：0  

李刚  孙晶岩  卞真付  周利霞  王晓磊  齐士超 《震灾防御技术》2012,7(1):92-99

天津市地震局在“十五”及“十一五”期间,利用MPLS VPN技术,建成了全国最快的区域级地震通信网络系统,实现了54个节点的高带宽互联.本文详细阐述了MPLS VPN技术在天津地震监测系统中的建设与应用情况,以期为今后更好的服务于地震行业提供参考.  相似文献   

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卞和方  张书毕  张秋昭  郑南山 《大地测量与地球动力学》2012,32(4):83-86

????????????????????????????????????????????GNSS??λ????????????????????????????????????????????????????λ?????????????????????????????????????????γ??????????????????????λ????????????????????????????????t???????????????????????  相似文献   

三种地下水位动态预测模型在吉林西部的应用与对比     

王宇  卢文喜  卞建民  侯泽宇 《吉林大学学报(地球科学版)》2015,45(3):886-891

准确而可靠地预测地下水埋深对生态环境保护和水资源规划管理具有重要意义。针对吉林西部浅层地下水位动态变化的复杂性和非线性,提出了基于小波分析与人工神经网络相结合的预测方法小波神经网络(WA-ANN)模型。将研究区2002年1月2009年12月当月降水量、蒸发量、人工开采量和前月平均地下水埋深4个参数作为输入,当月平均地下水埋深作为输出,建立浅层地下水埋深预测模型,并与BP神经网络(BP-ANN)模型和自回归移动平均(ARIMA)模型进行比较,对比分析了三者的建模过程及其模拟精度。结果显示:相比两种ANN模型,ARIMA模型建模过程更为简单,计算效率更高;但WA-ANN模型的拟合精度高于BP-ANN和ARIMA模型,预测效果更好。总体来看,WA-ANN模型在浅层地下水埋深预测中具有一定的应用推广价值。  相似文献   

利用湖州台形变观测资料检测地震激发的地球球形自由振荡     

方燕勋  卞根发  惠若愚  孙宗强 《中国地震研究》2016,(4):584-593

By using the digital observations of the pendulum tiltmeter, water tube tiltmeter,extensometer and volumetric strainmeter at Huzhou station and with the power spectrum density estimation method,we acquired the_0S_5-_0S_50 fundamental sphere free oscillations caused by the Japan earthquake on March 11,2011,then compared it with the PREM model. The relative errors are mostly bigger than 1.2‰. The extensometer and volume strainmeter can clearly detect _0S_2,_0S_3and_0S_4,which are closely related to the deep structure and earth's interior.  相似文献   

准噶尔盆地火山岩分类研究与应用     

王璞珺  缴洋洋  杨凯凯  张增宝  边伟华 《吉林大学学报(地球科学版)》2016,46(4):1056-1070

岩石分类一直是人们长期探索的课题。由于油气勘探的需要,针对储层研究的盆地火山岩分类已经成为火成岩研究的重要新方向。在综合分析国内外火山岩分类研究的基础上,根据3条野外剖面和21口钻井岩心岩屑的观察描述、岩石薄片鉴定和化学成分分析等资料,依照结构-成分-成因分类原则,建立了适于储层评价的准噶尔盆地石炭系火山岩及其他岩类的岩性分类体系和识别标准。将本区火山岩划分为火山熔岩、火山碎屑熔岩、火山碎屑岩、沉火山碎屑岩等4大类;同时将盆地内与火山岩共生的其他岩类也进行分类和识别,共划分出8大类45种基本类型。与我国东部的中新生代盆地火山岩不同,本区古生代火山岩普遍遭受较长期风化改造和蚀变作用,常见有绿泥石化、碳酸盐化和黏土矿化。这些蚀变会影响到TAS图解岩性判别的结果,因此笔者探讨了蚀变条件下的岩石识别和定名方法。本文分类体系针对火山岩储层研究,结果显示,基于该分类体系岩性与储集空间的类型及其变化规律呈现明显相关性,不同岩性的储集空间类型、组合方式和发育程度存在差异,由此可指导火山岩油气勘探。  相似文献   

地形在高大金字塔沙山形成发育过程中的作用——以敦煌鸣沙山-月牙泉地区为例     

张伟民  谭立海  边凯  牛清河 《中国沙漠》2016,36(5):1207-1215

地形在金字塔沙山形成发育过程中起着重要的作用。金字塔沙山通常形成于山前地带,应属于地形屏障影响下形成的一种沙丘类型。首先,上升气流的发育是山前风阻区气流的主要特征,地形屏障是上升气流发生发展的主要原因。沙山的坡脚、坡中及坡顶分别是上升气流的启动区、发育区及衰退区。上升气流是沙山增高增大发育的主要机制。其次,金字塔沙山多发育于局地环流发育较强的地带,局地环流与区域风况配置是形成复杂沙丘类型的重要因素。本区局地环流偏南风不仅持续时间长,且受到鸣沙山微地形的影响,下坡气流较强。实地观测结果破解了常规气候台观测数据难以揭示上升气流及局地环流对金字塔沙丘形成发育的影响。第三,下附地形在沙山形成发育过程中决定着沙丘发育的“临界尺度”,即丘体达到“临界尺度”的时候,坡面上升气流及风速放大作用逐渐显现,促使丘体增高增大发育,随着沙丘形态与上升气流的互馈作用进一步增强,金字塔沙丘逐渐形成演化为高大沙山。实地观测进一步证实了金字塔沙山是纵向（横向）沙丘形变的一种形式。并提出了金字塔沙山在地形条件下形成演化的一种新模式。  相似文献