Paleomagnetic result of the Lower-Cretaceous from Luanping basin,Hebei Province and its tectonic implications*

A paleomagnetic study of about 95 samples from 16 sites sampled in the Early Cretaceous in Luanping basin in Hebei Province was reported. Stepwise thermal demagnetization was used to isolate magnetic components. Most samples have a characteristic direction with a high temperature component above 500°C. The tectonic-corrected data areD = 347.8°,I = 50.4°, α₉₅ = 7.l°, and the corresponding pole position is at 76.1°N, 346.3°E,with dp =6.4°,dm = 3.8°, paleolatitude λ = 31.1°N. This result indicates a counterclockwise post-Cretaceous rotation of 30.7° ±9.8° with respect to the stable Ordos basin in the west of North China Block, and a non-significant northward motion. This rotation could be related to local fault action or structural detachment, or regional NNW-NWWward motion and collision of Kula-Pacific plate with eastern China since the Early Cretaceous.

     

汉江某区段堤防隐患探测的物探方法

运用探地雷达,电磁法,直流充电法以及自然电场法,查明了汉江某区段堤防中涌水通道的确切位置,渗水的范围,并根据物探异常的推断解释结果,提出了相应的治理方案。     

Paleomagnetic result of the Lower-Cretaceous from Luanping basin,Hebei Province and its tectonic implications*

A paleomagnetic study of about 95 samples from 16 sites sampled in the Early Cretaceous in Luanping basin in Hebei Province was reported. Stepwise thermal demagnetization was used to isolate magnetic components. Most samples have a characteristic direction with a high temperature component above 500°C. The tectonic-corrected data areD = 347.8°,I = 50.4°, α₉₅ = 7.l°, and the corresponding pole position is at 76.1°N, 346.3°E,with dp =6.4°,dm = 3.8°, paleolatitude λ = 31.1°N. This result indicates a counterclockwise post-Cretaceous rotation of 30.7° ±9.8° with respect to the stable Ordos basin in the west of North China Block, and a non-significant northward motion. This rotation could be related to local fault action or structural detachment, or regional NNW-NWWward motion and collision of Kula-Pacific plate with eastern China since the Early Cretaceous.     

滇池草海底泥疏挖对水体水质及底泥影响分析研究

1998年 5月起 ,滇池草海经过近 1年的疏挖 ,清除底泥约 4 0 0× 10 4 m3,使内草海水体质量有明显改善。内湖底质的有机污染物及金属污染物得到有效去除 ,减少了泥层中污染物向水体的扩散 ;大部分水体透明度达到 0 .8m ,已超过沉水植物恢复的需补偿深度 ,为草海水生态恢复创造了条件 ;疏浚区水深增加 ,湖容扩大 ,提高了草海的调蓄能力。但与外草海及外滇池对照点底泥相比 ,草海底泥金属污染物含量仍处较高水平     

北京-萨哈林剖面的地幔纵向速度结构

本文根据北京台网、大连、长春、牡丹江、海参威等26个台站的记录,选用了从北京地区到阿留申群岛西端的300多个地震,研究了北京-萨哈林剖面的地幔纵向速度分布。 用Herglotz-Wiechert公式计算得出的V-h作为初始模型,计算理论走时曲线,找出了与实际走时曲线符合较好的速度结构。其特点为:上地幔顶部的速度为7.8公里/秒;高速盖层中有正速度梯度;在约60-120公里深度范围内为低速层;130公里以下速度缓慢增大;在370-440公里、600-740公里有两个速度梯度较大的过渡层,其中以370-440公里的正速度梯度最大,与之相应的震中距为19°。在1060公里以下有微弱的正梯度。 用Kaila方法计算了深度为400公里左右的地震震源深度处的速度值,与上述结果一致。     

新疆西克尔地区微震波谱的初步研究

为探索大地震发生前孕震区内微震辐射波谱的变化,在新疆西克尔地区,用选频测震仪对微震波谱进行了观测和研究。选频测震仪分为6个频道,各道中心频率分别为6.0周、8.1周、15.7周、30.0周、50.0周、75.0周。初步结果表明:在一个地震系列中,随着临近较强地震（M_L≥3.2）的发生,微震P波在10周-60周频率范围内的谱值增高,其置信水平一般在70％以上。较强地震发生以后,微震P波在相应频率范围内的谱值下降。 文中还简要地分析了选频地震记录的物理意义,并对较强地震前,微震辐射波谱变化的原因作了初步说明。     

RESEARCH ON EARTHQUAKE EMERGENCY MAPPING METHOD BASED ON TEMPLATE MATCH

After an earthquake, earthquake emergency response and rescue are important ways to mitigate earthquake-induced losses. Various earthquake emergency maps can provide effective references and guidance to those actions. Currently, related studies include the investigation on symbols of emergency maps, remote sensing emergency mapping and GIS-based mapping methods. However, the existing studies overlook the characteristics of rapidity, dynamicity and variety of presentation methods in making earthquake emergency maps. In this paper, a map template matching method is used to quickly make earthquake emergency maps considering their characteristics. We take investigations on the service objects(users)of the earthquake emergency maps to understand the needs of making earthquake emergency maps. The audience theory in mass media field and map information transmission theory are adopted to classify the users of the earthquake emergency maps into four categories: earthquake emergency commanders, technical staffs for decision-making, earthquake emergency rescuers, and the public. The components of different types of users are described and then their diverse demands in earthquake emergency maps are analyzed, such as the needs of on-field disaster information maps, earthquake information maps, physical geography and social economic maps. Following those needs, we introduce the representation methods of the earthquake emergency maps according to their formats(vector or raster)and contents, such as point symbolization method, kilometer grid method, line symbolization method and range method. Then, we study the rapid plotting method of earthquake emergency map based on map template matching method. The core steps of the method include: 1)before earthquake, the templates of different earthquake emergency maps are designed, prepared and connect the earthquake emergency features with their related spatial database. The map layout and map elements are stored in the templates. 2)After earthquake, the earthquake emergency features will be generated from seismic models(such as attenuation model of earthquake magnitude and seismic intensity)or the information obtained from field investigation. 3)Corresponding earthquake emergency map template is selected in accordance with the generated seismic features. And the features are used to update related features inside the selected template. 4)Minor adjustments are made such as to the map scale and some map annotations to finally generate the formal earthquake emergency map. Architecture of template system of the earthquake emergency maps is designed, including map user level, map template level, template layer level and map element level. Regrading to the architecture, the general map template of earthquake emergency is presented which includes four main regions: title region, main picture region, auxiliary region and annotation region. The main picture region is the essential, which lays geographic background maps and earthquake emergency features. Finally, an earthquake emergency mapping system is developed. Based on the system, a case study is presented, which demonstrates making a simulated seismic intensity influence map. From three aspects, the case presents the application of the template-matching method including: generating earthquake emergency features, substituting the features inside the template with the generated features, and revising map annotations. Therefore, the map template matching method is verified so that it can be used to quickly generate various earthquake emergency maps.     

轨道调谐建立洛川黄土地层的时间标尺

对黄土高原中部洛川厚140m黄土剖面进行了黄土层间隔5cm、古土壤层间隔3cm的采样,在室内测量了全部样品的磁化率．以磁化率变化作为东亚夏季风气候变化的替代性指标,利用轨道调谐方法建立了黄土－古土壤序列的时间标尺．结果表明,B／M界线处的年龄是772KaB．P,午城黄土与离石黄土分界线的年龄为1348KaB．P,黄土堆积底界的年龄为2471KaB．P．．通过和古地磁场倒转点绝对年龄对比以及与太阳辐射量变化时间序列进行交叉谱分析,证明了新时间标尺的可信性．     

公路收费系统通用通信组件设计与实现

介绍了公路收费系统中所需的实时数据通信功能的设计,并通过组件方式,将其制作成具有一定安全性的通用组件,提供给应用系统调用,从而提高开发效率.     

时空过程网络可视化模拟与分析服务——以溃坝洪水为例

洪水溃坝等复杂灾害现象的时空过程模拟分析,是当前国际地理信息科学热点研究方向之一。随着网络的普及化,公众对GIS时空分析模型的网络实时集成和可视化分析提出了迫切的需求。本文以溃坝洪水为例开展了时空过程网络可视化模拟与分析服务研究,利用Web GL、HTML5、Ajax、Web Service、GPU并行计算等技术手段,通过探讨溃坝洪水时空模型计算优化、网络三维可视化模拟与动态交互分析等关键技术,研发了原型系统并进行应用实验。实验结果表明,本文研究成果有助于实现时空过程信息的网络发布,在线影响分析及动态可视化服务,可为分布式网络环境下溃坝洪水等时空过程信息管理和应急决策提供科学依据和技术支持。