Newly-generated Daliangshan Fault Zone—Shortcutting on the central section of Xianshuihe-Xiaojiang fault system

The Daliangshan fault zone is the eastern branch in the central section of Xianshuihe-Xiaojiang fault system. It has been neglected for a long time, partly because of no destructive earthquake records along this fault zone. On the other hand, it is located on the remote and inaccessible plateau. So far it was excluded as part of the Xianshuihe-Xiaojiang fault system. Based on the interpretation of aerophotographs and field investigations, we document this fault zone in detail, and give an estimation of strike-slip rate about 3 mm/a in Late Quaternary together with age dating data. The results suggest that the Daliangshan fault zone is a newly-generated fault zone resulted from shortcutting in the central section of Xianshuihe-Xiaojiang fault system because of the clockwise rotation of the Southeastern Tibetan Crustal Block, which is bounded by the Xianshuihe-Xiaojiang fault system. Moreover, the shortcutting may make the Daliangshan fault zone replace the Anninghe and Zemuhe fault zones gradually, and finally, the later two fault zones will probably die out with the continuous clockwise rotation.     

珠江口水域微表层中的痕量金属

采用自制滚筒式自动采样器采样，研究了珠江口水域微表层中Ｆｅ，Ｍｎ，Ｃｕ，Ｐｂ，Ｚｎ，Ｃｄ的含量、分布变化及富集状况。并通过颗粒痕量金属／颗粒Ｆｅ比值计算，探讨了痕量金属的来源。结果表明：Ｃｕ，Ｐｂ，Ｚｎ，Ｃｄ在微表层的平均富集系数分别为２．３，１．４，３．０和１．９。颗粒态Ｆｅ，Ｍｎ的平均富集系数为１．１和０．９。各种金属有明显的季节和空间变化，有各种不同的来源。     

世界一些大城市防灾减损的比较研究

比较分析了一些大城市的防灾减损措施，提出了具体对策。     

上海市居民乡村旅游行为特征及感知研究

运用旅游心理学原理,采用比较分析和交互分析等研究方法,分析了上海市居民乡村旅游的人口学特征、行为偏好以及效果感知,并提出加强乡村旅游宣传力度、观念创新和服务管理等建议.     

阿拉善高原古湖岸堤释光测年与晚第四纪湖面变化

阿拉善高原位于现代西风环流与东亚季风环流过渡带,该地区分布的湖泊对全球性气候变化响应极为敏感,阿拉善高原广泛分布的古湖岸堤为较准确地重建晚第四纪湖泊水位变化提供了良好载体。近年对黑河、石羊河尾闾湖泊以及吉兰泰盐池、雅布赖盆地等地的古湖岸堤的沉积地层以及石英和钾长石释光测年研究,重建了不同区域较高分辨率的末次间冰期以来湖泊时空演化过程。发现早在300 ka以前阿拉善高原就已经形成了高水位湖泊,黑河尾闾额济纳盆地在MIS 11或更早、MIS 9、MIS 7、MIS 5和MIS 1形成了高湖面湖泊,高湖面湖泊形成存在100 ka的周期。阿拉善高原在末次间冰期及全新世形成了稳定高湖面湖泊,但间冰期内部湖面波动具有空间差异性,东部区域湖泊高湖面出现在MIS 5e~5c和中全新世,西部湖泊高湖面出现在MIS 5a~5c和晚全新世。湖面变化的空间差异性很可能与冰期-间冰期旋回尺度及间冰期内部东亚夏季风与西风气候系统在阿拉善高原的相互作用密切相关。

     

Numerical simulation of a South China Sea typhoon Leo (1999)

Summary ?A South China Sea typhoon, Leo (1999), was simulated using the Penn State/NCAR mesoscale model MM5 with the Betts-Miller convective parameterization scheme (BMEX). The simulation had two nested domains with resolutions at 54 and 18 km, and the forecast duration was 36 hours. The model was quite successful in predicting the track, the rapid deepening, the central pressure, and the maximum wind speed of typhoon Leo as verified with reports from the Hong Kong Observatory (HKO). The structure of the eye, the eye wall, and the spiral convective cloud band simulated in the model are found to be comparable to corresponding features identified in satellite images for the storm, and also with those reported by other authors. A trajectory analysis was performed. Three kinds of trajectory were found: (1) spirally rising trajectories near the eye wall; (2) spirally rising/descending trajectories in the convective/cloud free belt; (3) straight and fast rising trajectories in a heavy convection zone along one of the cloud bands on the periphery of the tropical cyclone. Both the HKO and the U.S. Joint Typhoon Warning Center (JTWC) reported the rapid deepening of Leo started around 00 UTC 29 April. In the model, the eye was first formed in the lower troposphere, and it extended to the upper troposphere within a few hours. We speculate that the spin-up of cyclonic rotation in the low-level eye enhanced the positive vorticity along the low-level eye wall. The positive vorticity was then transported to the upper troposphere by convection, leading to an extension and growth of the eye into the upper troposphere. To examine the impact of convective parameterization scheme (CPS) on the simulation, the Grell scheme (GLEX) was also tested. The GLEX predicted a weaker typhoon with a wilder eye that extended not as high up in the upper troposphere as BMEX. The different structures of the eye between the BMEX and GLEX suggest that the mesoscale features of the eye are dependent on the convection. In other words, the vertical and horizontal distribution of convective heating is essential to the development and structure of the eye. Received December 18, 2001; accepted May 7, 2002 Published online: March 20, 2003     

中国北方烧变岩的分布、特征及研究意义*

中国北方烧变岩分布广泛,见于以昆仑山—秦岭—大别山为界的中国北方地区多个沉积盆地边缘,但地质学家对其研究较为薄弱。野外调查显示中国北方烧变岩主要以4种方式分布: (1)大面积连片分布,(2)沿山脉走向的线状分布,(3)沿河流下切河谷分布,(4)为第四系黄土覆盖。烧变岩主要为侏罗系、石炭—二叠系煤层自燃所致。各类型的烧变岩在中国烧变岩区不同程度发育,具瓷化结构、白化结构、烧熔结构、残余构造、气孔构造、微柱状节理、角砾状构造、垮塌构造、裂缝充填等结构和构造。其颜色以砖红色、赭红色、棕色、钢灰色最为典型,岩石中发育鳞石英、方石英、堇青石、铁堇青石、莫来石等典型高温矿物。中新世以来,中国西部、北部地区构造活动强烈,干旱气候加剧,烧变岩也主要形成于这一时期,但煤层自燃与构造运动、环境变化、古野火事件的耦合关系还鲜有提及,其所蕴含的各种地质信息值得在今后的研究中予以关注。     

中国对虾摄食行为的化学感觉生理学研究──Ⅲ.中国对虾幼体及早期仔虾的摄食行为及化学感觉

报道了中国对虾幼体及早期仔虾（ １）对轮虫（活体、死体）和卤虫无节幼体 （活体、死体）的摄食过程及摄食率；（２）对悬浮砂粒的摄食情况；（３）摄食水流的产 生机制、方向及模式；（４）对食物的化学敏感性。结果表明，中国对虾幼体及早期仔 虾化学感觉机能不明显。摄食附肢的协调运动产生摄食水流。摄食水流一方面将 食物带到口器附近，另一方面能促进对虾对食物的机械感受。摄食水流的方向还可 以逆转。幼体及早期仔虾对食物的选择主要依据其大小、形状和运动性，而与食物 的化学组成（味道）关系不大。此阶段的对虾采取了悬浮摄食模式，且主动和被动两 种模式并存。本研究还表明，将幼体和早期仔虾的食性简单地区分为草食或肉食性 值得商榷。     

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中国柑橘生产空间变迁及其驱动因素

综合运用产业集中度、探索性数据分析(ESDA)、产业重心模型、空间杜宾模型等方法对中国柑橘生产空间演变特征,以及驱动因素进行实证分析.结果显示:1978-2015年中国柑橘生产空间呈现扩张态势,可分为急剧增长期(1978-1991年)、低速增长期(1992-2000年)、稳步增长期(2001-2015年).中国柑橘生产...