国土资源信息标准化概述   总被引：2，自引：0，他引：2  

骆昌鑫  胡小华 《国土资源信息化》2008,(3):12-14

标准化是国土资源信息化建设的基础。本文对国土资源信息标准化的概念、目标与任务、总体框架进行了概述,并对国土资源信息化标准的编制与发布、实施与管理进行了说明。  相似文献   

基于城市地块变化的基准地价更新研究     

杨小雄  何志明  黄小兰 《热带地理》2007,27(5):446-450

采用传统的方法编制地价指数及更新基准地价需要大量的地产交易资料,而我国大多数城镇地产交易市场尚未发育完善,存在收集资料困难,操作难度大等问题。文中在研究城市地块变化及其测度的基础上,通过分析地块变化指数和地价指数之间的相关性,建立了相关模型,从而测算出地价指数并更新基准地价。以土地市场发育不太完善的广西县级城市——桂平市为例进行了实证研究,并采用德尔菲法对结果的合理性进行了分析。结果显示,专家评价平均值为49.83,标准差为2.256 7,符合度为99.66%,说明基于地块变化的基准地价更新的方法是科学可行的。  相似文献   

How to cut a sediment core for <Superscript>210</Superscript>Pb geochronology: a supplement     

Xueqiang?LuEmail author  Eiji?Matsumoto 《Environmental Geology》2005,49(2):251-252

To obtain the profile of excess ²¹⁰Pb in sediment column, it is necessary to section the collected core to date. Sectioning thickness is generally not explicit. An approach when sedimentation rate is constant has been suggested by Lu and Matsumoto (Environ Geol 47:804–810, 2005). This paper addresses the case when sedimentation rate is variable. Actually, it is possible to assume that sedimentation rate is constant within the sectioning thickness and based on this concept, a tentative approach for determining reasonable sectioning thickness is proposed.  相似文献   

International standard (ISO) on seismic actions for designing geotechnical works–An overview     

Susumu Iai   《Soil Dynamics and Earthquake Engineering》2005,25(7-10):605-615

The seismic performance of geotechnical works is significantly affected by ground displacement. In particular, soil–structure interaction and effects of liquefaction play major roles and pose difficult problems for engineers. An International Standard, ISO23469, is being developed for addressing these issues in a systematic manner within a consistent framework. The objective of this paper is to give an overview of this International Standard.In this International Standard, the seismic actions are determined through two stages. The first stage determines basic seismic action variables, including the earthquake ground motion at the site, the potential for earthquake-associated phenomena such as liquefaction and induced lateral ground displacement. These basic variables are used, in the second stage, for specifying the seismic actions for designing geotechnical works. In the second stage, the soil–structure interaction plays a major role. Types of analyses are classified based on a combination of static/dynamic analyses and the procedure for soil–structure interaction classified as follows:

– simplified: soil–structure interaction of a global system is modeled as an action on a substructure;

– detailed: soil–structure interaction of a global system is modeled as a coupled system.

Regional　Tectonic　Deformation　Background　and　Medium-　and　Short-Term　Precursors　to　the　Minle-Shandan　Earthquakes     

Zhang Xi 《中国地震研究》2005,19(1):12-21

INTRODUCTIONOnOctober 2 5,2 0 0 3,twoearthquakesofMS6 .1andMS5.8hitMinleandShandanofGansuProvinceinsuccession (at 38.4°N ,1 0 1 .2°E ;and 38.4°N ,1 0 1 .1°E) .Theseismicfaultisthrustandleft lateraltheMinle DamayingfaultwhichstrikesEWandisaffiliatedtot…  相似文献   

松花江、嫩江洪水等级划分标准及规律分析   总被引：6，自引：0，他引：6  

张桂华  潘华盛  董淑华  杜春英 《黑龙江气象》2000,(1):13-16

松花江（哈尔滨江段）、嫩洒（江桥站）洪水可划分成５个等级。第Ⅰ级为无洪水,又可分为２个副级,即１ａ级为中水,１ｂ级为枯水;第２组为警戒洪水;第３级为一般洪水;第４级为大洪水;第５级为特大洪水。各级划分是采用流体力学能量方程,位能与动力之各用Ｅ指数表示,再将Ｅ值按Ｐ－Ⅲ型分布将其密度函数转换成Ｚ指数,按Ｚ值正态分布特点划分洪水等级。松花江在９８年中共发生过１９次洪水,嫩江在４７年中共发生过１０次洪水  相似文献   

Evidence of nonlinear site response in HVSR from SMART1 (Taiwan) data     

P. Dimitriu  N. Theodulidis  P. -Y. Bard 《Soil Dynamics and Earthquake Engineering》2000,20(1-4)

Deamplification of strong motion and the increase of the effective period of soil deposits are typical nonlinear effects; we seek them in SMART1-array data by applying the horizontal-to-vertical spectral ratio (HVSR) technique. The recordings, from four soil and one rock stations, represent 23 earthquakes (M_L 4.9–7.0); PGA varies between 20–260 cm/s². For each station, mean HVSR curves are calculated for two PGA ranges: <75 cm/s² and >100 cm/s² (weak and strong motion). At the soil stations, the “weak” (linear) and “strong” (nonlinear) responses are significantly different. Below 1–1.8 Hz, the nonlinear response exceeds the linear one. Above 2 Hz, the nonlinear response drops below the linear one and above 4–6 Hz below unity (deamplification). From 10 to 16 Hz, the two responses converge. One soil site shows significant negative correlation between resonance frequency and ground acceleration. Such behaviour agrees with other empirical studies and theoretical predictions. Our results imply that the HVSR technique is sensitive to ground-motion intensity and can be used to detect and study nonlinear site response.  相似文献   

绿色分析化学技术的研究进展   总被引：13，自引：2，他引：11  

刘咸德  王林 《岩矿测试》2000,19(4):268-274

绿色分析化学技术已成为国际分析化学的前沿,其目标是利用以好的方法和原理,尽量不用或少用有在化学试剂,将环境污染减少到最低限度,目前的研究主要集中于环境友好的样品处理和富集技术,如微波消解、微波萃取、超临界流体萃取、固相萃取、固相微萃取和膜萃取等,以及绿色分析技术,如用开发仪器的功能来消除干扰,从而取代使用掩蔽试剂,将不机相测定变为水相测定等,文章对上述内容进行了综述,引用近期文献５４篇。  相似文献   

地震孕育机制与破裂机制的研究   总被引：6，自引：0，他引：6  

周友华 《地球科学进展》2000,15(6):637-643

在理论上得出地震孕育发生的普遍物理机制是:地震前孕震区在垂直向会逐步形成、发展弹性的“拉疏隆起—压缩凹陷”的不稳结构,在水平向也多会形成对称相间分布的两个弹性压缩区及两个弹性拉疏区。应变的“压缩区与拉疏区同时产生、对应存在、共为一体”的这种双向应变结构是地壳构造运动中形成孕震体与非孕震体的根本区别,也是能用以首先找到孕震地区的主要依据;地震的破裂机制是:孕震体形成的双向应变结构,构成了应力集中后的失稳与剪切破裂的必要条件,当初始破裂后,就会引起压缩区与拉疏区发生逆转性的弹性膨胀与收缩的相互配合而不断提供位错空间,从而能使应力与破裂快速地传递与扩张。这一地震孕育与破裂机制的认识,几乎能解释绝大多数的地震前兆现象及震时震后的冒砂、冒水与断层的破裂、错动现象。  相似文献   

累托石/聚丙烯酸(钠)-丙稀酰胺吸水保水复合材料的制备及性能     

范力仁  王春龙  栗海峰  景录如  沈上越 《地球科学》2007,32(1):105-110

采用焙烧-磁选法、酸洗提纯法、煅烧法均能有效减少湖北钟祥累托石粘土中的黄铁矿.实验用累托石粘土中黄铁矿含量为4.37%, 硫含量为2.32%.采用焙烧磁选法, 温度300℃、时间2.0h、二次磁选后, 累托石粘土中硫含量降为0.52%;酸洗法, 酸液浓度60%、时间1.0h、温度60℃时, 硫含量为0.57%;煅烧法, 当温度550℃、时间为0.5h时, 硫含量为0.78%.研究发现所得粘土矿物对聚合复合法制备累托石/聚丙稀酰胺-丙烯酸(钠) 吸水保水复合材料的阻聚作用不明显, 且不影响后续聚合反应最高硫含量约为0.78%.在65~70℃反应条件下, 含煅烧累托石粘土20%、丙烯酰胺15%、引发剂0.25%、交联剂0.08%, 丙烯酸中和度为80%的吸水保水复合材料的吸去离子水倍率为870, 吸自来水倍率为250, 吸生理盐水倍率为68.累托石粘土添加量在0%~30%之间时, 吸水保水复合材料的吸液倍率比不含累托石的吸水树脂高.吸水保水复合材料吸液倍率从870g/g降到84g/g时, 凝胶强度从49g/cm2上升到235g/cm2.   相似文献