喀什—乌恰地区流动地磁测量数据处理及初步分析

介绍了2008年在喀什—乌恰地区32个测点的流动地磁测量数据的处理方法。利用该数据建立了喀什—乌恰地区地磁场的曲面样条模型,绘制了区域地磁基本场分布图。以2005年中国地磁场球冠谐模型为参考场剥离了岩石圈磁场,绘制了喀什—乌恰地区岩石圈磁场局部异常分布图。表明岩石圈磁场局部异常与测区内地震在空间上有一定的对应关系。     

黄海南部小黄鱼群体遗传多样性研究

以黄海南部吕泗渔场的小黄鱼（Pseudosciaena polyactis）群体为研究对象,采用ISSR技术对其遗传多样性进行分析。在使用的99个引物中,有10个引物可扩增出清晰稳定的条带,共计64条,分子质量在300-3000bp。其中多态性片段42条,多态性片段比例为65．63％,个体间相似性系数0．6667-43．8764,平均为0．7813,个体间平均遗传差异为0．2187。Shannon多样性指数12．0832,多样性值0．1888。表明黄海南部小黄鱼群体保持较高的遗传多样性,具有较大的变异潜力。提出应采取有效管理保护措施,以维持小黄鱼群体的遗传多样性水平,使该渔业资源得到合理利用。     

多尺度相关性分析的机载双极化InSAR轨道误差校正方法

在高分辨率机载干涉SAR成像处理过程中,由于载机飞行过程中偏离理想轨迹,需要高精度的惯导系统和GPS系统记录载机的运动轨迹并进行运动补偿.然而,由于目前传感器导航精度的限制,在完成运动补偿处理后仍然存在轨道误差,从而影响干涉相位的精度,本文提出了一种机载双极化InSAR轨道误差去除方法.该方法利用小波多尺度分析对不同极...     

Elimination of Interferences in the Determination of Palladium,Platinum and Rhodium Mass Fractions in Moss Samples using ICP‐MS/MS

Moss samples (Pleurozium schreberi) exposed to traffic‐related emission of Pd, Pt and Rh were analysed in this study. Successful elimination of interferences was achieved in the determination of Pd, Pt and Rh mass fractions in these samples using inductively coupled plasma‐tandem mass spectrometry (ICP‐MS/MS). Based on the results, a reliable determination of Pd, Pt and Rh mass fractions in microwave‐digested moss samples was obtained using ammonia (10% NH₃ in He) in the collision/reaction cell when ¹⁰³Rh was measured either on‐mass (103→103) or with mass‐shift (103→171) and mass‐shifts for ¹⁰⁸Pd (108→159) and ¹⁹⁵Pt (195→229) were used. The ICP‐MS/MS procedure was validated using BCR‐723 (road dust) as a reference material. In addition, a good agreement between the ICP‐MS/MS results and the results obtained with cloud point extraction and quadrupole ICP‐MS was observed for the moss samples.     

Laboratory Measurements of Vortex- and Wake-Induced Vibrations of A Tandem Arrangement of Two Flexible Risers

The dynamic response of two flexible model risers in tandem arrangement immersed in a stepped current was analyzed. The risers, with an external diameter of 20 mm and a total length of 6200 mm, had an aspect ratio of 310. They were hinged to the support structure at the center-to-center distances away 3?12 times the external diameter. The top 1200 mm was exposed to a uniform current at a speed which was up to 0.9 m/s (the Reynolds number was 18000) and the rest in still water. The dynamic responses, which were obtained through the Fiber Bragg Grating strain gauges mounted on the surface, were analyzed by studying the cross-flow amplitudes and modal weights. The cross-flow vibration were observed up to the third mode, and the modal transformation from the second mode to the third mode was clearly observed. The experiment confirmed that the typical vortex-induced vibration (VIV) had occurred on the up-stream riser. But for the down-stream riser, the main excitation mechanism was wake-induced vibration (WIV). The modal transformation of WIV was more complex than that of VIV, which might be helpful for other researchers to study the interference effect.     

Historical Landscape Change in Yellowstone National Park: Demonstrating the Value of Intensive Field Observation and Repeat Photography

Although transportation and outdoor recreation are well‐recognized aspects of national parks, few studies have explored these aspects from the perspective of human geography as a means of analyzing historical landscape change. This paper offers an innovative synthesis of methods for studying cultural landscape change over time through a case study of the historical geography of transportation, tourism, and outdoor recreation along the Howard Eaton Trail (HET) in Yellowstone National Park. We conducted research through a field course that combined repeat photography, archival research, Geographic Information Systems (GIS), and traditional field methods. Results indicate that a combination of repeat photography and other methods can create an effective means of evaluating cultural landscape change; even short field courses provide opportunities for students and faculty to conduct collaborative research that provides powerful, multidimensional, situated‐learning experiences; and repeat photography creates datasets that may benefit future research and teaching.     

Study on a gravity precursor mode of the M_S=7.0 Lijiang earthquake

Introduction Earthquake prediction must be based on some kind of precursors. The precursors are some things that will indicate a shock occurrence (MEI, et al, 1993). The information of earthquake precursors comes from a deep-seated interior of crust. Therefore the analysis and pick-up of pre-cursory information should be based on the internal process of crustal movement, which includes the earthquake preparation. Being the weak parts of crust, the slip and dislocation of faults can cause cru…     

入室盗窃临近重复案件与孤立案件分布的影响因素对比研究

以中国南方某特大城市YP区为例,结合犯罪地理学主要理论选取相关变量构建二元逻辑回归模型,探讨区域环境对入室盗窃临近重复案件和孤立案件分布的影响差异。研究发现：居民数量、银行&ATM机和公园集聚的区域发生临近重复案件的概率比孤立案件更高,而道路密度高的社区难以发生临近重复案件;青少年人口比重高和低租金住户多的社区会加剧弱势群体、问题人群的集中趋势,临近重复犯罪发生的可能性也会随之上升,其中青少年人口的影响程度高于低租金住户。研究结果可对微观社区层面入室盗窃临近重复犯罪的治安防控与警务政策制定提供一定的参考。     

一元线性回归模型显著性检验方法的改进

采用重复观测的方法,即对每个测量点重复m次的方法,组建新的数对(xi,■),建立改进的一元线性回归模型y=β0 β1xi ■■~N(0,σ2/m),对残差平方和Qε进行分解为误差平方和QE和重复观测变异平方和QL。从而给出不同的检验方法确定回归方程拟合的好坏。