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1.
ＺＮ－１型数字钟控监测仪──一种新型的光记录电源为保证观测资料连续可靠，所使用的光记录电源应具有较完善的报警功能。现介绍一种新型的光记录电源──ＺＮ－１型数字钟控监测仪。该仪器使用ＣＭＯＳ数字集成电路和数字钟专用集成电路，集各种功能于一体，除电源线至... 相似文献
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陆顺永 《地震工程与工程振动》1996,(4)
提出了基础－地基系统具有频变参数的质－弹－阻模型，在这个模型中，系统的刚度Ｋ＝Ｋ０－Ｋ１ω２和阻尼系数Ｃ＝Ｃ０＋Ｃ１ω随系统振动频率而变化。文章以竖向振动为例，给出了用稳态激振下的动力反应测量值确定系统参数Ｋ０、Ｋ１，Ｃ０，Ｃ１的方法；讨论了基础频变刚度系统与附加质量系统的等效范围和差别。 相似文献
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按照地球膨胀学说进行全球构造动力物理模拟的相似性研究，得到了膨胀地球岩石层弹性球壳力学模型的方程分析相似准则和地幔物质沿膨胀裂谷通道上涌流动的方程分析相似准则．按照各相似准则的约束，计算得到了满足与膨胀地球原型相似的模型参数：膨胀初始半径为０．４６ｍ；原始岩石层的厚度、密度分别为３×１０－３ｍ和（１．２－１．８）×１０ｋｇ／ｍ３，其强度为１０４Ｐａ；原始地球膨胀内压为４．２５×１０４Ｐａ；原始地表重力为－１．２５×１０－２Ｎ／ｋｇ；上涌物质密度、粘度分别为１．２×１０２ｋｇ／ｍ３和２×１０２Ｐａ·ｓ；原始地幔物质上涌厚度、速度和加速度分别为２．５×１０－２ｍ，２．０×１０－３ｍ／ｓ和３×１０２ｍ／s2．由此表明材料物性等条件能够较好地满足原型要求的模型条件． 相似文献
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陆顺永 《地震工程与工程振动》1996,16(4):30-36
提出了基础－地基系统具有频变参数的质－弹－阻模型，在这个模型中，系统的刚度Ｋ＝Ｋ０－Ｋ１ω＾２和阻尼系数Ｃ＝Ｃ０＋Ｃ１ω随系统振动频率而变化。文章以竖向振动为例，给出了用稳态激振下的动力反应测量值确定系统参数Ｋ０，Ｋ１，Ｃ０，Ｃ１的方法；讨论了基础频变刚度系统与附加质量系统的等效范围和差别。 相似文献
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地电供电对地磁观测干扰的排除 总被引：3，自引：1，他引：2
随着数字化地震技术的发展,台站逐步进入了智能化的管理,各台站都相应地使用了计算机和数字化智能仪器,目前许多地震台站的地磁观测都安装了ＺＮＣ－Ⅱ质子智能磁力仪,每分钟观测一个地磁Ｚ分量值,并利用设定的程序将它记录在单片机上,通过信号线与计算机相接,能够... 相似文献
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本文使用Ｎａｋａｉ预处理和Ｖｅｎｅｄｉｋｏｖ调和分析方法，对慎西地区下关台ＧＳ１５－２２７重力仪１９８７－１９９２年观测资料和丽江台ＥＴ－２２重力仪１９９０－１９９２年的观测资料进行了分析处理，并对其计算结果进行仪器动力学特征及惯性和海潮负荷，进而确定慎西地区潮汐基准参数为：δ（０１）＝１．１６６±０．００１，δ（Ｍ２）＝１．１６３±０．０００，△ψ（０１）＝－０．３８±０．０８，△ψ（Ｍ２）＝－ 相似文献
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地震震级—频度G—R关系的偏离度 总被引：3，自引：1，他引：3
假设震级－频度分布服从对应于Ｇ－Ｒ式母体分布污染的情况，文中引进震级分布偏离度来描述实际资料分布与Ｇ－Ｒ式的偏离程度。在Ｇ－Ｒ式分参数稳健估计的基础上给出了偏离度的计算方法。华北地区１９８０－１９９３年取资料时间窗长１年，滑动步长１个月的ζ值计算结果表明，６级左右强地震前的半年至一个半左右ζ值明显为相对稳定的低值，震后呈高值变化。 相似文献
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大同—阳高地震及强余震电磁辐射异常 总被引：3，自引：0，他引：3
叙述了河北地震电磁辐射观测台网的分布、仪器系统的主要性能和观测资料既况及其分析使用方法，研究了大同－阳高１９８９年１０月１８日６．１级的中强震群和１９９１年３月２６日５．８级地震前后台网电磁辐射记录资料的变化情况，统计、计算了异常参数和数量；得出了地震电磁辐射异常具弱－强－弱－地震、临近地震频率升高，异常变化越强烈，异常时间越长，异常量越大，地震也越强等特征的结论。 相似文献
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为计算１９８９年１０月１８日大同－－阳高６．１级地震的震源参数,根据断裂力学的有关公式分析了断裂扩展过程中应力和位移的变化,利用弹塑性力学中的达格代尔塑性区中最大位移的公式计算了应力场的初始剪切应力τ。和地震释放的总能量ＥＴ;根据不同作用行震波资料和历史地震等烈度线所得出的不同震级的地震矩,利用最小二乘法拟合得出山西地区不同震级地震矩之间的关系,计算出大同一阳高６．１级地震的地震矩和其它震源参数。 相似文献
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形状记忆合金力学性能的试验研究 总被引：19，自引：0，他引：19
本文针对一种国产形状记忆合金材料,通过试验和分析,首先定性地探讨了其力学性能随激振频率、环境温度、应变幅值和滞回圈数的变化情况;随后,提出了一种简化的四折线力学本构模型,在试验的基础上,确定了模型的特征参数;最后,将该材料与国外同类材料进行了对比,指出了国产材料的不足和应改进之处。 相似文献
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Monika E. Bailey George A. Isaac Ismail Gultepe Ivan Heckman Janti Reid 《Pure and Applied Geophysics》2014,171(1-2):257-276
An automated short-range forecasting system, adaptive blending of observations and model (ABOM), was tested in real time during the 2010 Vancouver Olympic and Paralympic Winter Games in British Columbia. Data at 1-min time resolution were available from a newly established, dense network of surface observation stations. Climatological data were not available at these new stations. This, combined with output from new high-resolution numerical models, provided a unique and exciting setting to test nowcasting systems in mountainous terrain during winter weather conditions. The ABOM method blends extrapolations in time of recent local observations with numerical weather predictions (NWP) model predictions to generate short-range point forecasts of surface variables out to 6 h. The relative weights of the model forecast and the observation extrapolation are based on performance over recent history. The average performance of ABOM nowcasts during February and March 2010 was evaluated using standard scores and thresholds important for Olympic events. Significant improvements over the model forecasts alone were obtained for continuous variables such as temperature, relative humidity and wind speed. The small improvements to forecasts of variables such as visibility and ceiling, subject to discontinuous changes, are attributed to the persistence component of ABOM. 相似文献
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Motovilov Yu. G. Bugaets A. N. Gartsman B. I. Gonchukov L. V. Kalugin A. S. Moreido V. M. Suchilina Z. A. Fingert E. A. 《Water Resources》2018,45(1):128-134
A physically based model of runoff formation with daily resolution has been developed for the upper part of the Ussuri basin with an area of 24400 km2 based on ECOMAG hydrological modeling platform. Two versions of the hydrological model have been studied: (1) a crude version with the spatial schematization of the drainage area and river network based on DEM 1 × 1 km with the use of soil and landscape maps at a scale of 1: 2500000 and (2) a detailed version with DEM 80 × 80 m and soil and landscape maps of the scale of 1: 100000. Each version of the model has been tested for two variants of meteorological inputs: (1) meteorological forcing data (temperature, air humidity, precipitation) at eight weather stations and (2) with the involvement of additional data on precipitation collected at 15 gages in the basin. The model has been calibrated and validated over a 34-year period (1979–2012) with the use of runoff data for the Ussuri R. and its tributaries. The results of numerical experiments for assessing the sensitivity of model hydrological response to the spatial resolution of land surface characteristics and the density of precipitation gaging stations are discussed. 相似文献
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Improvement of the Noah land surface model for warm season processes: evaluation of water and energy flux simulation 总被引：1，自引：0，他引：1
The Noah model is a land surface model of the National Centers for Environmental Prediction. It has been widely used in regional coupled weather and climate models (i.e. Weather Research and Forecasting Model, Eta Mesoscale Model) and global coupled weather and climate models (i.e. National Centers for Environmental Prediction Global Forecast System, Climate Forecast System). Therefore, its continued improvement and development are keys to enhancing our weather and climate forecast ability and water and energy flux simulation accuracy. North American Land Data Assimilation System phase 1 (NLDAS‐1) experiments indicated that the Noah model exhibited substantial bias in latent heat flux, total runoff and land skin temperature during the warm season, and such bias can significantly affect coupled weather and climate models. This paper presents a study to improve the Noah model by adding model parameterization processes such as including seasonal factor on leaf area index and root distribution and selecting optimal model parameters. We compared simulated latent heat flux, mean annual runoff and land skin temperature from the Noah control and test versions with measured latent heat flux, land surface skin temperature, mean annual runoff and satellite‐retrieved land surface skin temperature. The results show that the test version significantly reduces biases in latent heat, total runoff and land skin temperature simulation. The test version has been used for the NLDAS phase 2 (NLDAS‐2) to produce 30‐year water flux, energy flux and state variable products to support the US drought monitor of National Integrated Drought Information System. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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通过在SAMI2模式的电子能量方程中添加人工加热项,数值模拟了在加热条件下磁场线上电子温度与电子密度的扰动情况,并对比了不同加热条件下的扰动效应.结果表明,入射到电离层中的大功率无线电波与等离子体相互作用,能够有效造成整条磁场线上电子温度的升高而产生电子温度扰动,尤其是加热点处,温度可增加3倍多;由于电子温度升高,压力平衡受到破坏,引发等离子体扩散进而导致电子密度扰动;电子密度扰动使得垂直于磁场线的电子密度梯度发生变化,这有可能形成电离层管(Ionosphere duct);电子温度和电子密度的扰动幅度随着加热时间的推移而减小,即扰动逐渐趋于稳定.电子温度与密度的扰动与加热率存在一种非线性关系. 相似文献
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地下（矿井和隧道内）超前探测灾害水源是磁共振测深（Magnetic Resonance Sounding,MRS）方法应用的新领域,在地球物理方法中是一个难题.本文在地面磁共振探测理论的基础上,建立地下全空间模型,推导直立线圈的磁共振响应信号表达式,对比国际标准模型验证了数值计算的准确性.引入旋转系数矩阵,计算任意地磁场方向和线圈方向的激发场垂直分量.研究了磁共振响应信号与线圈法向偏角和倾角的关系,指出当线圈法向方向垂直于地磁场方向时,磁共振响应信号最大.同时,研究表明磁共振超前探测距离与激发脉冲矩和接收灵敏度紧密相关,激发脉冲矩越大,接收灵敏度越高,则超前探测距离越大,但存在极限距离.在地下线圈尺寸受限的情况下,为使检测信号灵敏度为5 nV时,超前探测距离达到30 m,提出了边长2 m线圈的匝数优化方案,共圈模式最少需要100匝,分离线圈模式最少需要10匝发射线圈和160匝接收线圈.仿真模型试验结果证明,随着噪声水平增大,磁共振超前探测距离和反演分辨率均减小.泽雅隧道探测实践表明,本文提出的地下空间磁共振理论在矿井和隧道环境中进行超前探测是可行的. 相似文献
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宋贯一（1991,2006）相继发现日-地之间存在一种奇特的能量（动量）相耦合的自然现象:当太阳辐射光压作用于地表之后,地球表面物质的特殊物理性质会自然地把太阳辐射光压立刻分解为两部分,即P1和P2.其中P1为全球各纬度带内单位海洋和陆地表面接收到的等值光压（P1为随时间和纬度而变化的变量）.在一个回归年的时段内,由P1在北、南两半球上的不平衡分布激发自转轴摆动,引起转动惯量的变化（该变化是目前所了解到的地球转动惯量的最大变化）并产生极移,该项极移运动的周期为12个月左右.由于P1在北、南半球上的分布相对赤道是基本对称的和规则的,P1对自转轴摆动的激发可称谓“规则性激发”;P2为全球各纬度带内单位陆地和海洋表面接收到的光压值之差（P2为随时间和纬度而变化的变量）.在一个回归年的时段内,由 P2在北、南两半球上的不平衡分布激发自转轴摆动而产生的极移运动周期为14个月附近.由于P2在北、南两半球上的分布相对赤道是不对称和不规则的, P2对自转轴摆动的激发可称谓“不规则性激发”.这种天然存在的力源,恰恰是近百年来世界各国研究地球自转的地球物理学家渴望寻找的那种既能激发自转轴产生自由章动、又使其摆动含有两个不同周期（12个月和14个月）的激发力源.正是这一奇特自然现象的发现,才使长期以来困扰地球物理学领域内的极移、极移所包含两个周期的涨落变化及由此引起的地球自转速度变化等自然之谜得以破解成为可能. 本文作者仅对天文观测的极移运动周期及其极移运动所包含的两个周期分量在一定的范围内变化的成因作出了详细的解析,并得出如下结论： （1）极移运动主要是由太阳光压P1 和P2共同激发引起的.天文观测的极移摆动周期的涨落变化是太阳光压（P1＋P2）激发自转轴摆动过程中,在空间上自转轴的摆动中心相对自转轴中心（地心）移动造成的,涨落范围在395～403±2天之间,即天文观测的极移运动的实际计算周期应在13.0～13.3个月之间变化.（2）极移所含的周年期摆动是由太阳光压P1激发的.天文观测的周年期摆动周期涨落很小,变化于365.24～365.53天之间.在一个回归年内,由于日-地间距离的变化,使地球表面接受到的太阳辐射光能产生微小差异则是造成观测的周年摆动周期稍有拖长的原因.（3）极移所含的钱德勒摆动周期是由太阳光压P2激发的.天文观测的钱德勒周期涨落较大,变化于426～437±2天之间,即实际计算周期应在14.0～14.4个月之间变化.观测的钱德勒摆动周期的变化是太阳光压P2激发自转轴摆动过程中,在空间上自转轴的摆动中心相对自转轴中心（地心）移动造成的.上述的定量解析数据均得到实际观测资料的验证,为极移光压成因理论的正确性提供了具体详实的证据. 相似文献
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André St‐Hilaire Taha B. M. J. Ouarda Zoubeida Bargaoui Anik Daigle Laurent Bilodeau 《水文研究》2012,26(9):1302-1310
Water temperature is a key abiotic variable that modulates both water chemistry and aquatic life in rivers and streams. For this reason, numerous water temperature models have been developed in recent years. In this paper, a k‐nearest neighbour model (KNN) is proposed and validated to simulate and eventually produce a one‐day forecast of mean water temperature on the Moisie River, a watercourse with an important salmon population in eastern Canada. Numerous KNN model configurations were compared by selecting different attributes and testing different weight combinations for neighbours. It was found that the best model uses attributes that include water temperature from the two previous days and an indicator of seasonality (day of the year) to select nearest neighbours. Three neighbours were used to calculate the estimated temperature, and the weighting combination that yielded the best results was an equal weight on all three nearest neighbours. This nonparametric model provided lower Root Mean Square Errors (RMSE = 1·57 °C), Higher Nash coefficient (NTD = 0·93) and lower Relative Bias (RB = ? 1·5%) than a nonlinear regression model (RMSE = 2·45 °C, NTD = 0·83, RB = ? 3%). The k‐nearest neighbour model appears to be a promising tool to simulate of forecast water temperature where long time series are available. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献