裂隙的弹性耦合模型及应用

将裂隙视为两种半无限均匀介质经弹簧联结起来的应力连续而应变非连续的物理模型。依据平面波的传播理论提出由振幅比或裂隙耦合动刚度表示裂隙的粘合程度。推导了裂隙两侧地震波振幅的比值与裂隙耦合动刚度的关系。最后介绍了该项研究在对敦煌榆林窟崖体裂隙灌浆效果进行的人工地震检测中的应用情况     

卫星动态观测数据揭示中国地表色调分布及时序变化特征

本文对2001年—2010年的MODIS光谱反射率数据进行时空聚类,得到2001年—2010年8天合成的色调信息,并初步分析了中国地表色调的时空分布格局及变化趋势,得出以下主要结论:(1)中国地表主色调主要由代表植被的绿色、裸土的褐色、裸土与植被混合的黄色、水体的蓝色以及冰雪的白色这5种颜色组成。分布在西北地区的褐色在一年中4个季节都为主色调。NDVI值较低的绿色光谱簇在春秋冬3个季节都为主色调,分布在南方的热带、亚热带针叶林以及灌木区。NDVI值较高的绿色光谱簇只在夏季一个季节为主色调,分布在长江中下游、华南、西南以及东北部分地区。永久白色主要分布在西藏、青海、四川等多年积雪地区。(2)黄淮海平原农业区色调在一年中呈现褐色—绿色—褐色—绿色—褐色的变化,与第一轮生长—间歇—第二轮生长物候历一致。长江中下游以及华南水稻播种和插秧时节有独特的光谱簇,呈现出植被与水体混合的特征。从华南地区、长江中下游地区到河北、陕西、甘肃、宁夏再到黑龙江,从南到北呈现出作物播种时间推迟、收割时间提早、生长期变短的现象。(3)甘肃北部、四川北部、山西北部、河北北部是年际主色调在绿色和黄色之间变化最为频繁的区域。这些年际主色调变化频繁区域也是中国绿度变化最显著的区域,也是在LUCC分类中易产生错误的地区。     

沼泽湿地对污水中NH4+-N和PO3-4-P净化模拟研究

选取三江平原典型沼泽湿地--毛苔草沼泽,通过人工施加氮肥和磷肥来模拟农田污水排入沼泽湿地后,沼泽植物对污水的净化效果.从植物营养吸收角度进行野外实地污水净化模拟研究,对植物直接吸收利用的营养成分NH4+-N、PO34--P进行了测试分析.研究表明毛苔草沼泽对水中的NH4+-N、PO34--P的净化随时间的推移呈现明显的指数衰减下降趋势,随着氮、磷含量的增加,沼泽湿地对污水净化逐渐变慢,净化所需时间增长,曲线数值方程模拟效果较好.     

SD智能数显仪打印功能的实现

本文介绍了ＳＤ智能数显仪与微型打印机的接口,并编程实现其功能。     

云南测震台有线信道与无线信道互为备份传输方案设计

针对云南省测震台网对连续率提升的需求,结合现行网络框架以及已有网络接入条件,通过路由器及服务器配置,设计并实现以有线信道为主,无线信道为辅的传输方案,为提升云南测震台网运行率提供一种选择。     

石家庄市应急避难场所信息管理系统设计与实现

基于石家庄市地震应急避难场所及医院的实际情况,利用百度地图API接口,开发了应急避难管理系统.该系统将避难场所及医院信息存储在MySQL数据库中,通过数据的检索、调用,将避难场所及医院的位置、面积、可容纳人数等信息显示在系统中.实现了信息展示、路线规划等功能,在突发事件发生后可减轻灾难损失,提高公共服务能力.     

Gravel‐bed river evolution in earthquake‐prone regions subject to cycled hydrographs and repeated sediment pulses

Sediment often enters rivers in the form of sediment pulses associated with landslides and debris flows. This is particularly so in gravel‐bed rivers in earthquake‐prone mountain regions, such as Southwest China. Under such circumstances, sediment pulses can rapidly change river topography and leave the river in repeated states of gradual recovery. In this paper, we implement a one‐dimensional morphodynamic model of river response to pulsed sediment supply. The model is validated using data from flume experiments, so demonstrating that it can successfully reproduce the overall morphodynamics of experimental pulses. The model is then used to explore the evolution of a gravel‐bed river subject to cycled hydrographs and repeated sediment pulses. These pulses are fed into the channel in a fixed region centered at a point halfway down the calculational domain. The pulsed sediment supply is in addition to a constant sediment supply at the upstream end. Results indicate that the river can reach a mobile‐bed equilibrium in which two regions exist within which bed elevation and surface grain size distribution vary periodically in time. One of these is at the upstream end, where a periodic discharge hydrograph and constant sediment supply are imposed, and the other is in a region about halfway down the channel where periodic sediment pulses are introduced. Outside these two regions, bed elevation and surface grain size distribution reach a mobile‐bed equilibrium that is invariant in time. The zone of fluctuation‐free mobile‐bed equilibrium upstream of the pulse region is not affected by repeated sediment pulses under the scenarios tested, but downstream of the pulse region, the channel reaches different fluctuation‐free mobile‐bed equilibriums under different sediment pulse scenarios. The vertical bed structure predicted by the simulations indicates that the cyclic variation associated with the hydrograph and sediment pulses can affect the substrate stratigraphy to some depth. Copyright © 2017 John Wiley & Sons, Ltd.     

红山基准地震台ELF电磁观测资料异常特征分析

对河北省红山基准地震台2014年3月7日至2015年12月31日ELF观测的天然电磁场数据进行处理,研究电磁场强度与视电阻率变化规律,分析2014年8月3日鲁甸6.5级地震、2015年的4月19日文安3.0级地震、4月25日尼泊尔8.1级地震、11月15日滦县2.9级地震发生前后电磁短临异常现象,结果表明,1 Hz、39 Hz、178 Hz电磁场自功率谱有明显的台阶、突跳和集丛现象,视电阻率异常变化幅度达到1—2个数量级。     

Study of the correlations between main shocks and aftershocks and aftershock synthesis method

To consider the influence of aftershocks in engineering design, the correlations between main shocks and aftershocks should be examined, and an aftershock simulation method with main shock ground motions needs to be developed. In this study, the data on the sequences of main shock-aftershock ground motions and other related parameters were collected. Using these data, correlations between the magnitude, frequency, duration and energy of the main shock-aftershock ground motions were investigated. The results showed that the magnitude of the aftershock can be larger than that of the main shock. The shapes of the Fourier amplitude spectra of main shocks and aftershocks were similar; however, the predominant frequency and high-frequency components of the aftershock tended to be larger. Considering the magnitude difference between the main shock and the aftershock, the correlation of durations was explored. Additionally, a new concept, the duration ratio, was defined to describe the concentration of seismic energy release, and main shock energy was strongly positively correlated with the energy attenuated during the main shock-aftershock sequence. Finally, based on these results regarding correlation, an aftershock synthesis using recorded main shock ground motions was constructed with the trigonometric series method for seismic design, and some examples are given to analyze the rationality of this synthetic method.

     

贵州乌江流域人口与经济发展协调性研究

贵州乌江流域是典型的山地流域,流域自然生态环境恶劣,人口与经济发展矛盾突出,探究流域人口与经济协调发展关系对于推动流域人口与经济可持续发展具有重要意义。选取2001~2015年贵州乌江流域各区域相关数据,运用人口-经济弹性、地理集中度、耦合指数、空间自相关和重心分析等方法对流域人口与经济协调发展关系进行探究。结果表明：① 在总量规模上,流域人口增长与经济增长协调度较高,但流域内各区域却存在差异。② 人口、经济地理集中度在空间分布上存在区域差异,流域中部区域较高且由中部向四周逐渐降低。人口、经济地理集中度在全域空间上莫兰指数值逐渐变小,表明流域人口、经济地理集中度空间自相关性在减弱,人口、经济发展的空间独立性逐渐增强。③ 人口重心、经济重心逐渐向远离流域几何重心的西南方向移动,人口重心与经济重心发生偏离,贵州乌江流域存在区域发展非均衡性。