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1.
耿胜利 《地震地磁观测与研究》1986,(1)
CGY-1A型磁传感器是根据电磁感应原理设计而成,其灵敏度很高,达280μV/γ·Hz。配LH型磁放大器,其分辨率可达4×10~(-3)γ/mm·Hz。该器件与国内现用大地电磁测深磁探头以及美国现用磁探头器件在同一技术条件下进行对比测试,其结果表明:CGY-1A型磁传感器可以记录到适当频率的天然电磁场,这样为分析高空磁层和地球内外场耦合、探测地下构造、普查石油、地热资源有着实际价值。 相似文献
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根据中国地震局地球物理研究所四室提供的资料,2000年10月份首都圈地区(38.0°～41.0°N,113.0°～120.0°E)共发生ML≥2.0地震10次(见表1)。10月10日06时45分发生在钱营的ML2.9地震是本月最显著的事件。本月地震频度与9月份基本持平,震中主要分部在首都圈东部和西部,中部地区相对较为平静。表1 2000年10月份首都圈地区ML≥2.0地震序号发 震 时 刻 年月日时分秒 震中位置φN/(°) λE/(°)震级/ML震 中012000-10-01T16-02-0540.1118.62.1迁安022000-10-02T00-37-0540.5113.52.3阳高032000-10-10T06-45-0539.7118.42.9钱营… 相似文献
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动力扰动下太湖梅梁湾水-沉积物界面的营养盐释放通量 总被引：2，自引：2，他引：2
通过波浪水槽试验,研究了不同水动力扰动条件下太湖梅梁湾水-沉积物界面的营养盐通量.结果发现,水动力扰动对该通量的影响很大,在中等扰动强度下(水底波切应力为0.019N·m-2,相当于梅梁湾中部夏季盛行风-东南风风速5～7 m·s-1),TN,DTN和NH4+-N的通量分别为1.92×10-3,-1.81×10-4和5.28×10-4mg·m-2·s-1(向上为正,向下为负),而TP,TDP和SRP的通量分别为5.69×10-4,1.68×10-4和-1.29×10-4mg·m-2·s-1.根据对气象资料的统计,夏季5～7 m·s-1东南风风速的最大持续时间为15h,以上述通量和风速持续时间进行计算,太湖底泥区域按水面积的47.45％,将分别有111tTN,32tNH4+-N,34tTP和10tTDP进入水体,可分别导致整个太湖水体中相应的平均浓度升高约0.025,0.007,0.007和0.002 mg·1-1.当扰动增大时(水底波切应力为0.217 N·m-2,相当于梅梁湾中部东南风速10～11 m·s-1),营养盐通量显著增加,其中TN,DTN和NH4+-N分别达1.16×10-2,6.76×10-3和1.14×10-2 mg·m-2·s-1,而TP通量亦大幅度上升,达到2.14×10-3 mg·m-2·s-1,上述通量的增加幅度均达到一个量级以上.但是,TDP的通量有所减小,其值为9.54×10-5 mg·m-2·s-1,而SRP虽然存在增加趋势,但其通量值却很小(5.42×10-5 mg·m-2·s-1).统计结果显示,太湖地区该风速的持续时间不超过5h.若以5h计,在上述强扰动情况下,营养盐释放量分别为232t TN,134.9t TDN,228t NH4+-N,42.7 t TP,2.0t TDP和1.1tSRP,水体中相应的平均浓度的升高量为0.050,0.029,0.049,0.009,0.0004和0.0002 mg·1-1.由此可见,在浅水湖泊中,动力扰动能造成水体中营养盐浓度的急骤升高,虽然在微扰动情况下,有些指标的释放通量出现负值(如DTN和SRP),水底沉积物表现为上述营养盐成分的汇集场所,但沉积物中大多数营养盐成分会随着底泥悬浮和水体-沉积物界面环境条件的改变而进入水体,给水体生态系统带来严重影响,这也是浅水湖泊所具有的显著特征之一. 相似文献
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发 震 时 间震 中 位 置月 -日 T时 :分 :秒φN/ (°) (′)λN/ (°) (′)地 点震 级ML深 度h/ km 精 度0 1- 16 T11:5 8:44 .0 37°14′ 112°0 2′汾阳市 3.0 10 10 1- 2 2 T0 1:11:47.0 36°15′ 111°38′洪洞县 3.0 1410 1- 2 6 T17:0 7:42 .7 35°11′ 111°5 6′垣曲县 3.2 1110 2 - 0 1T0 1:0 7:35 .6 39°5 2′ 113°44′大同县 3.45 10 2 - 0 4T0 7:14:11.837°38′ 112°31′太原市 3.110 10 4- 12 T0 0 :45 :2 3.837°0 3′ 111°5 2′介休市 3.2 1320 5 - 15 T16 :11:16 .839°2 8′ 113°2 4′应 县 4.… 相似文献
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Theearthquakes (ML≥ 3 0 )catalogueofFouthquarterinnortheasternarea ,2 0 0 2序号发 震 时 间地 震 位 置月日时 分 秒北 纬东 经地 点震级(ML)深度(km)精度110 90 9-3 8-3 4 0 48°48′ 13 0°2 9′黑龙江嘉荫 3 9822 10 12 13 -5 1-4 7 7 3 9°2 3′ 12 2°13′辽宁省普兰店 3 0 1113 10 2 5 0 5 -12 -0 5 5 40°3 6′ 12 2°5 2′辽宁省海城 3 6814 10 2 5 18-3 4-2 5 83 8°3 3′ 12 0°15′渤海 3 7 25 112 19-2 2 -3 2 5 3 8°2 2′ 12 0°2 6′黄海 3 5 26112 5 12 -2 0 -5 0 93 8°5 6′ 12 1… 相似文献
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对安丘地震台16年室内基线的研究结果表明:室内基线观测精度可达到2×10~(-7).室内基线的变化大部分是室温引起的地表热形变,其量值达7×10~(-5).地壳活动的信息仅为5×10~(-6).因而降低和消除地表热形变是提高室内基线应用价值的关键. 相似文献
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根据中国地震局分析预报中心提供的资料,2000年8月份华北地区(33.0°～42.0°N,111.0°～125.0°E)共发生ML≥3.0地震6次,无ML≥4.0地震发生(见表1)。8月14日06时10分孟县ML3.5地震是本月最显著的事件。本月地震频度与7月份持平,震中主要分布在华北东部,其他地区相对较为平静。表1 2000年8月份华北地区ML≥3.0地震序号发 震 时 刻 年月日时分秒 震中位置φN/(°) λE/(°)震级/ML震 中012000-08-07T23-18-0937.9122.23.0黄海022000-08-14T06-10-1234.9112.83.5孟县032000-08-14T18-30-2135.4122.93.0黄海042000-08-21T1… 相似文献
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中国l地壳运动观测网络首期观测数据处理 总被引：6，自引：0，他引：6
介绍了中国地壳运动观测网络的布设、基准站和基本站首期观测情况。利用GAMIT和GLOBK软件对首期观测数据进行了处理，计算结果归算到ITRF97框架上。单天整体解结果表明：基线重复性NS向分量为2.28+0.87×10-9×S，EW向分量为3.67+0.82×10-9×S，高程分量为6.84+1.29×10-9×S(S为GPS站间距离，以mm为单位)。对基准网和基本网的整体平差结果表明：点位精度水平分量为2～3 mm，高程分量为3～5 mm，基准网和基本网首期观测达到了设计要求。 相似文献
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磁传感器标定技术与误差分析 总被引：1，自引：0，他引：1
本文介绍CGY—系列磁传感器标定时的标准磁场为长螺线管“匀强”磁场源,其磁电转换常数为125nT/mA,频带范围0—15KHz,精度为5×10~(-3)。采用电磁感应法进行标定,其标定结果误差估算不大于2.5％,理论设计验证,误差不大于4％,此标定方法优于圆电流场源和亥姆霍兹磁场源装置标定方法。 相似文献
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M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities. 相似文献
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《地震工程与工程振动(英文版)》2014,(4)
正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and 相似文献
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George W. Housner 《地震工程与工程振动(英文版)》2008,7(2):I0001-I0001
Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States. 相似文献
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《国际泥沙研究》2014,(4)
正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study 相似文献
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JianCheng Shi 《中国科学:地球科学(英文版)》2014,57(10):2281-2282
正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases 相似文献
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Dissolved total carbohydrates (DTCH), dissolved free monosaccharides (DFMS), dissolved organic carbon (DOC), biodegradable DOC (BDOC), and humic substances (HS) were measured in White Clay Creek (WCC), a stream in southeastern Pennsylvania Piedmont, USA. Samples were collected over different seasons and under baseflow and stormflow conditions. DOC concentrations ranged from 1.0 to 12.8 mg/L C with the highest concentrations associated with stormflows. Carbohydrates ranged from 0.42 to 12.4 μM and accounted for 2.9 to 12.7% of the DOC. Humic substances represented the major DOC fraction, accounting for 55 to 72% of the DOC pool under all flow conditions. The humic fraction had a lower carbohydrate content (4.4%) than the non-humic fraction of DOC (7.2%). Stormflow DOC was enriched in carbohydrates relative to baseflow DOC, but the percentage of humic-C changed little. Carbohydrates were primarily present as dissolved polysaccharides (55%), but a significant fraction was bound to humic substances (40%), while a small proportion was present as monosaccharides (5%). The major monosaccharides in stream water, listed in order of decreasing concentration, included glucose, galactose, rhamnose, xylose, arabinose, mannose, and fucose. On average (30.6 ± 7.4)% (n = 44) of the stream water DOC was biodegradable, and carbohydrates accounted for 9.9 to 17.7% of the BDOC. 相似文献