石羊河流域主汛期降水日变化特征

利用石羊河流域2009-2013年主汛期(6-8月)有完整资料的32个区域气象站和5个自动气象站共37个站点逐时降水资料,运用常规的气候统计方法,采用逐时降水量、逐时降水频次、逐时降水强度和不同持续时间降水4个指标对石羊河流域主汛期降水日变化特征进行了研究。结果表明:石羊河流域主汛期降水总量及日数的空间分布总体上与其地理位置、海拔、纬度以及影响系统密切相关,表现为自上游向下游呈递减趋势,降水强度空间分布较复杂。石羊河流域主汛期小时降水量、降水频次及降水强度呈三峰型分布,主要集中出现在20:00-23:00、01:00-09:00、14:00-20:00,其中强降水呈现双峰分布,基本都出现在20:00-23:00、14:00-20:00;石羊河流域主汛期持续1～3 h短时降水的降水量和降水次数大于持续10 h以上降水过程的降水量和降水次数,且持续1～6 h的短时降水多发于午后到傍晚,持续时间超过6 h的长持续性降水的最大降水量通常出现在夜晚-凌晨和午后-傍晚。     

新疆阿勒泰小红山铜矿床地质-地球化学特征及找矿预测

小红山铜矿位于西伯利亚板块南缘阿尔泰陆缘活动带中,区内构造演化复杂,岩浆活动强烈,具有较好的成矿条件。通过对小红山铜矿地表、深部原生晕空间套合与叠加分析,以及稀土、微量、同位素等岩石地球化学测试,研究了矿体空间分布规律、矿床成因和成矿机理,认为小红山铜矿属于中低温岩浆热液铜矿床,受构造及变霏细岩的控制。对铜矿区进行了成矿预测,划分出找矿靶区5处,其中A类和B类找矿靶区各1处,C类找矿靶区3处。     

欧拉模型模拟波浪的抑制数值耗散效应的一种简单方法

数值波浪水槽是研究波浪及波浪与结构相互作用的常用工具，可在真实尺度下产生波浪，并提供流场的详细数据。然而，大部分数值波浪水槽都存在数值耗散和数值色散问题，数值耗散使波能缓慢消散，数值弥散在波传播过程中使波频移。本文在有限差分法（FDM）求解欧拉方程的基础上，提出了一种抑制数值耗散效应的简单方法，考虑阻尼项的影响，对波的传播解进行了解析求解。该方法的主要思想是在动量方程中附加一个源项，其强度由数值阻尼效应的强度决定。本文通过对规则线性波、Stokes波和不规则波的数值模拟，验证了该方法的有效性。结果表明，本文方法可有效减小数值波浪水槽中存在的数值耗散现象。     

中国洞穴动物调查研究进展

黑暗、潮湿、常温的岩溶地下洞穴,使生活其中的动物构成特殊的群落,表现出特殊的行为和体征,根据其生活习性,洞穴动物可分为真洞穴动物（Troglobites）、半洞穴动物（Troglophiles）和洞栖动物（Trogloxenes）;中国岩溶洞穴动物研究开始于上世纪70年代后期,已经先后发现洞穴动物新种131个,在洞穴动物行为及特征方面,开始了大量的调查研究,取得了较好的进展。考虑到中国岩溶洞穴分布广泛、数量众多,中国洞穴动物调查研究还有很大的潜力。     

利用单基站GPS数据建立电离层VTEC模型

介绍几种常用的电离层VTEC模型.通过利用哈尔滨市CORS观测网络的单基站GPS双频观测数据建立多种电离层VTEC 模型,并对建模成果进行分析与研究.结果表明,模型选择和GPS卫星空间分布对建模有较大影响.     

An Improved Simplified Method for Predicting the Hydroelastic Response of Mat-Like VLFS

Very Large Floating Structures (VLFS) have received considerable attention recently. Efficient and accurate estimation of their hydroelastic responses in waves is very important for the design. The most efficient approach would obviously be the analytical one. Within the category of analytical approaches, the simplified method proposed by Ohkusu and his colleague are of special characteristics. However, when one studies their methods, several questions arise. The purpose of this paper is to critically study the simplified methods proposed by Ohkusu and his colleague in order to answer these questions. Some problems in their original methods have been found and possible improvements are suggested. It is concluded that the improved simplified method using the same idea of Ohkusu and his colleague could provide a reasonable estimate of the hydroelastic response of mat-like VLFS in a certain range of incident angles of waves.     

Hydroelastic analysis of flexible floating interconnected structures

Three-dimensional hydroelasticity theory is used to predict the hydroelastic response of flexible floating interconnected structures. The theory is extended to take into account hinge rigid modes, which are calculated from a numerical analysis of the structure based on the finite element method. The modules and connectors are all considered to be flexible, with variable translational and rotational connector stiffness. As a special case, the response of a two-module interconnected structure with very high connector stiffness is found to compare well to experimental results for an otherwise equivalent continuous structure. This model is used to study the general characteristics of hydroelastic response in flexible floating interconnected structures, including their displacement and bending moments under various conditions. The effects of connector and module stiffness on the hydroelastic response are also studied, to provide information regarding the optimal design of such structures.     

干湿循环作用下红黏土收缩特征研究

以贵州某高速公路沿线红黏土为研究对象,开展了干湿循环作用后红黏土的收缩特性试验研究,探讨了干湿循环次数和初始含水率对红黏土收缩性状的影响.试验结果表明：同一循环次数内,各试样的环向收缩率在6～8 h时达到稳定,而轴向线缩率则需更长的稳定时间;随着初始含水率增加,各试样的初始轴向线缩率减小,而初始环向收缩率增加;28%含水率试样具有相近的最终轴向变形和环向变形量,而34%含水率的试样环向变形量高于轴向变形量;初始含水率变化不大,但体缩率的变化率却明显不同,说明干湿循环过程使得土体内部结构变得不稳定,但颗粒间相互作用的本质未发生明显变化;干湿循环作用对重塑红黏土最优含水率位置的基本无影响,这说明其未能改变黏土集聚体内对结合水的最大吸附能力.通过压汞试验得到了不同干湿循环作用后试样的孔隙分布情况,随着干湿循环次数的增加小孔径尺寸和分布密度改变较小,而大孔径尺寸减小,分布密度也在减小.干湿循环作用对聚集体内孔径的影响大于对微聚体内孔隙影响,与所测得的宏观收缩规律相吻合.     

Guanling Biota: A Marker of Triassic Biotic Recovery from the end-Permian Extinction in the Ancient Guizhou Sea

After a slow recovery from the end-Permian extinction during the Early Triassic and rapid radiation in the Middle Triassic, evolution of organisms reached a new peak phase in the Late Triassic. The Guanling Biota from the Wayao Member （conodont Paragondolella polygnathiformis Zone）, Falang Formation, Xinpu, Guanling County, Guizhou Province, southwestern China corresponds to this peak that marks the full recovery from the end-Permian extinction of marine ecosystems. The biota is of high diversity, containing well preserved and completely articulated skeletons of vertebrates comprising marine reptiles, fishes, and invertebrates including crinoids, ammonites, bivalves, and other fossils, and is one of the best examples of marine ecosystem records in life history. The fossil marine reptiles and crinoids are most significant in this biota, especially the marine reptiles, which provide an important link between the Triassic Pacific and Tethys, and between Triassic basal forms and the Jurassic-Cretaceous marine top predators. The most remarkable fossils are the large completely articulated ichthyosaur skeletons up to and more than 10 m, and the first recorded thalattosaurs and placodonts in China. Following our review, of the 17 named reptilian taxa the eight listed here are considered to be valid： three ichthyosaurs （Qianichthyosaurus zhoui Li, 1999; Guizhouichthyosaurus tangae Cao and Luo in Yin et al., 2000, Guanlingsaurus liangae Yin in Yin et al., 2000）, three thalattosaurs （Anshunsaurus huangguoshuensis Liu, 1999, Xinpusaurus suni Yin in Yin et al., 2000, Xinpusaurus kohi Jiang et al., 2004）, and two placodonts （Sinocyamodus xinpuensis Li, 2000, Psephochelys polyosteoderma Li and Rieppel, 2002）. Mixosaurus guanlingensis Cao in Yin et al., 2000 might be a junior synonym of Qianichthyosaurus zhoui Li, 1999, and Cymbospondylus asiaticus Li and You, 2002 and Panjiangsaurus epicharis Chen and Cheng, 2003 might be junior synonyms of Guizhouichthyosaurus tangae Cao and Luo in Yin et al., 2000. It needs to re-describe the holotypes after a complete preparation for clarifying the taxonomic status of Typicusichthyosaurus tsaihuae Yu in Yin et al., 2000, Xinpusaurus bamaolinensis Cheng, 2003, Neosinosaurus hoangi （Zhou in Yin et al., 2000）, Wayaosaurus geei Zhou in Yin et al., 2000, Wayaosaurus bellus Zhou in Yin et al., 2000 and Placochelys ？ minutus Yin and Luo in Yin et al., 2000.     

贵州关岭动物群产出地层的地球化学特征及其对物源和沉积环境的指示意义

对贵州关岭晚三叠统法郎组瓦窑段底部的毛凹剖面系统地采集了105个岩石样品，测定了样品中的36种化学元素含量。作者对它们进行元素富集因子（EF）分析、R型聚类分析、R型因子分析、元素和氧化物的含量与Al2O3的含量比值以及δCe在剖面中垂向变化的分析，讨论了元素含量变化的制约因素、沉积物的来源、古海洋氧化还原条件的变化、关岭动物群的埋藏环境。结果表明：研究的5.2 ~17.7 m段剖面地层以陆源碎屑和生物碎屑混合沉积为主，沉积物来源于陆壳，而不是火山和热液的来源，其沉积的氧化还原条件多次反复变化；元素的含量变化主要受陆源物质、氧化还原条件、生物碎屑以及成岩作用控制；从元素地层学角度将所研究的剖面段从下到上可划分为4层，第1层至第4层元素对比值曲线呈现出平缓波动-频繁波动-平缓波动的周期性变化特征；该段偏还原的环境对海百合及海生爬行动物化石的保存和埋藏起了良好的作用。