Dynamic response of a dip slope with multi-slip planes revealed by shaking table tests

This study investigated the effect of internal discontinuity on the dynamic response of a dip slope and evaluated the performance of Newmark’s theory on the sliding of a dip slope with multi-slip planes. A series of shaking table tests were performed under various geometric conditions to explore the dynamic behavior of a dip slope under different external excitations. The test results, including for deformation processes and critical accelerations, under various slope angles, slope sizes, and seismic intensities were examined and further compared with Newmark’s theory. The results of this study are summarized as follows: (1) two types of slope sliding (differential and complete) were determined. (2) Increasing the slope angle and the height of sliding mass tended to shorten the duration of slope deformation. (3) Critical acceleration of the slope increased gradually with increasing peak ground accelerations of input excitations; when the slope height and dip angle increased, the critical acceleration decreased. (4) The triggering time became earlier as the frequency of input excitation increased; the magnitude of sliding mass greatly depended on the amplitude of the input excitation. (5) By comparing critical acceleration between the experimental and theoretical results, Newmark’s theory was determined to overestimate critical acceleration during seismic-induced dip slope failure. This may cause unsafe evaluations, and sliding along existing discontinuities develops more easily in reality.     

江西省县域“三化”协调发展度空间格局演变及其障碍因子诊断

以县域单元为研究对象,从新型城镇化、新型工业化和农业现代化3个方面构建“三化”协调发展度评价模型,利用ESDA和GIS技术,揭示2000—2012年江西省县域“三化”协调发展度的空间格局演变过程,并采用障碍因子诊断模型找出阻碍江西省县域“三化”协调发展度提升的障碍因子。结果表明：江西省县域“三化”协调发展水平较低,提升潜力大;在总体空间格局上,江西省县域“三化”协调发展度水平具有较强的空间自相关性,相似地区集聚分布,热点区沿浙赣线和京九线（江西段）北段成带状集聚,冷点区主要向赣东南地区集聚,鄱阳湖周边地区的冷点区逐渐消失;阻碍江西省县域“三化”协调发展度提升的障碍因子主要表现为地均工业增加值、工业化率、城镇化率、人均社会固定资产投资额和人均农林牧渔业增加值5个方面,地均工业增加值历来是主要的障碍因子。     

Cognitive radio resource allocation based on coupled chaotic genetic algorithm

A coupled chaotic genetic algorithm for cognitive radio resource allocation which is based on genetic algorithm and coupled Logistic map is proposed. A fitness function for cognitive radio resource allocation is provided. Simulations are conducted for cognitive radio resource allocation by using the coupled chaotic genetic algorithm, simple genetic algorithm and dynamic allocation algorithm respectively. The simulation results show that, compared with simple genetic and dynamic allocation algorithm, coupled chaotic genetic algorithm reduces the total transmission power and bit error rate in cognitive radio system, and has faster convergence speed.     

THE BALANCE BETWEEN SUPPLY AND DEMAND OF WATER RESOURCES AND THE WATER—SAVING POTENTIAL FOR AGRICULTURE IN THE HEXI CORRIDOR

The Hexi Corridor is an important base of agriculture development in Northwest China. According to recent statistics, there are 65.94×10⁸m³ of water resources available in the Hexi Corridor. At present, net consumption in development and utilization is 43.33×10⁸m³. Water supply and demand reach a balance on the recent level of production, but loss of evaporation and evapotranspiration is as much as 25.69×10⁸m³. So net use efficiency of water resources is 59%. Based on analyzing balance between water and land considering ecological environment at present, there exists the serious water shortage in the Shiyang River system where irrigation lands have overloaded. There is a comparative balance between supply and demand of water resource in the Heihe River system; and the Sule River system has some surplus water to extend irrigation land. Use of agriculture water accounts for 83.3% and ecological forest and grass for 6.9%. The Hexi Corridor still has a great potential for water saving in agriculture production. Water-saving efficiency of irrigation is about 10% by using such traditional technologies as furrow and border-dike irrigation and small check irrigation, and water-saving with plastic film cover and techniques of advanced sprinkler and drip/micro irrigation etc. cansave more than 60% of irrigated water. Incremental irrigation area for water-saving potential in the Hexi Corridor has been estimated as 56% – 197% to original irrigation area. So the second water sources can be developed from water saving agriculture in the Hexi Corridor under Development of the Western Part of China in large scale. This potential can be realized step by step through developing the water-saving measures, improving the ecological condition of oasis agriculture, and optimizing allocation of water resources in three river systems. Foundation item: Under the auspices of the Key innovation Project Engineering of Chinese Academy of Sciences (KZcx-1-10-03) Biography: GAO Qian-zhao (1942 –), male, a native of Changzhou, Jiangsu, Professor and supervisor of Ph. D students. His research interests include hydrology and rational utilization of water resources in the arid zone.     

南京大学太阳塔CCD成像光谱观测系统和初步观测结果

本文介绍南京大学太阳塔的ＣＣＤ成像光谱观测系统的结构，工作方式，给出了该系统的一些性能测试结果，作为应用该系统的实例，文中给出了根据该系统观测的二维光谱资料，经处理得到的一个Ｈａ耀斑在线心和不同偏带处单色像的变化过程，该耀斑的亮度场轮廓图和速度场轮廓图。     

三江平原沼泽湿地与稻田CH4排放对比研究

2001年5～10月,在三江平原对毛果苔草沼泽湿地和由沼泽湿地开垦后稻田的CH4 排放通量进行了同步观测.三江平原毛果苔草沼泽湿地CH4排放通量范围是1.32～46.38 mg/(m2@h),平均值为17.29 mg/(m2@h).稻田的CH4 排放通量范围是0.05～24.37 mg/(m2.h),平均值为6.67 mg/(m2.h).沼泽湿地CH4 排放通量平均值是稻田的2.5倍,水分条件和因土地利用方式改变引起的土壤理化条件变化是导致二者的CH4 排放通量产生差异的主要原因.CH4 排放通量有明显的季节变化,7～8月高温期出现CH4 排放高峰.     

九龙山构造须二段致密砂岩储层裂缝特征及成因

裂缝是川西北地区九龙山构造上三叠统须家河组二段致密砂岩天然气藏分布的重要控制因素。利用野外露头、岩心、成像测井和薄片等资料,并结合实验分析,对该区裂缝的成因类型、发育特征、形成期次及其形成机理进行了分析。研究区须二段致密砂岩储层发育有构造裂缝和成岩裂缝两种类型,其中以构造裂缝为主,主要有北东东-南西西向、北北东-南南西向和北西-南东向3组。按照裂缝的倾角,构造裂缝又可分为高角度构造裂缝和低角度构造裂缝。其中,高角度构造剪切裂缝主要是在印支晚期、燕山晚期和喜马拉雅期3期构造作用下形成,形成构造裂缝的力源来自于龙门山以及米仓山-大巴山的水平构造挤压作用、深埋藏造成的异常高压流体压力以及抬升剥蚀造成的应力作用。低角度构造裂缝主要与构造挤压作用下断层的逆冲作用或层间滑动造成的近水平剪切作用有关。     

南阳凹陷西大岗露头区核桃园组裂离不整合的发现及其地质意义

本文重点解剖南阳凹陷唐河低凸起西大岗露头区核桃园组二段中亚段（E2h2^2）与上亚段（E2h2^1）的接触界。通过实测剖面,结合室内岩石薄片鉴定、粒度分析、X衍射和地球化学分析,确认该接触界面实为裂离不整合,不同于前人认识的“古暴露面”,系由北东向控盆断裂一曲洼断裂强烈的伸展作用所造成,代表了南阳凹陷以南部控盆断裂为主向以东部控盆断裂为主的转变。     

Identification of isotopically primitive interplanetary dust particles: A NanoSIMS isotopic imaging study

We have carried out a comprehensive survey of the isotopic compositions (H, B, C, N, O, and S) of a suite of interplanetary dust particles (IDPs), including both cluster and individual particles. Isotopic imaging with the NanoSIMS shows the presence of numerous discrete hotspots that are strongly enriched in ¹⁵N, up to ∼1300‰. A number of the IDPs also contain larger regions with more modest enrichments in ¹⁵N, leading to average bulk N isotopic compositions that are ¹⁵N-enriched in these IDPs. Although C isotopic compositions are normal in most of the IDPs, two ¹⁵N-rich hotspots have correlated ¹³C anomalies. CN⁻/C⁻ ratios suggest that most of the ¹⁵N-rich hotspots are associated with relatively N-poor carbonaceous matter, although specific carriers have not been determined. H isotopic distributions are similar to those of N: D anomalies are present both as distinct D-rich hotspots and as larger regions with more modest enrichments. Nevertheless, H and N isotopic anomalies are not directly correlated, consistent with results from previous studies. Oxygen isotopic imaging shows the presence of abundant presolar silicate grains in some of the IDPs. The O isotopic compositions of the grains are similar to those of presolar oxide and silicate grains from primitive meteorites. Most of the silicate grains in the IDPs have isotopic ratios consistent with meteoritic Group 1 oxide grains, indicating origins in oxygen-rich red giant and asymptotic giant branch stars, but several presolar silicates exhibit the ¹⁷O and ¹⁸O enrichments of Group 4 oxide grains, whose origin is less well understood. Based on their N isotopic compositions, the IDPs studied here can be divided into two groups. One group is characterized as being “isotopically primitive” and consists of those IDPs that have anomalous bulk N isotopic compositions. These particles typically also contain numerous ¹⁵N-rich hotspots, occasional C isotopic anomalies, and abundant presolar silicate grains. In contrast, the other “isotopically normal” IDPs have normal bulk N isotopic compositions and, although some contain ¹⁵N-rich hotspots, none exhibit C isotopic anomalies and none contain presolar silicate or oxide grains. Thus, isotopically interesting IDPs can be identified and selected on the basis of their bulk N isotopic compositions for further study. However, this distinction does not appear to extend to H isotopic compositions. Although both H and N anomalies are frequently attributed to the survival of molecular cloud material in IDPs and, thus, should be more common in IDPs with anomalous bulk N compositions, D anomalies are as common in normal IDPs as they are in those characterized as isotopically primitive, based on their N isotopes.     

天山古生代洋陆转化特点的几点思考

本文简要评述了天山地区前寒武纪洋陆格局、古生代洋盆的开启与闭合的时限、古生代洋陆格局、下石炭统底部碰撞造山磨拉石发现的地质意义、以及石炭－二叠纪大规模裂谷岩浆作用形成的地球动力学背景等问题，并且提出了一些新的思考。