三江流域地形对汛期强降水作用诊断分析

采用1981-2010年汛期逐日降水资料、NCEP再分析资料及地形资料,对三江流域汛期暴雨进行天气学分型,选取典型个例对强降水落区与地形进行天气学分析。结果表明:三江流域主要暴雨天气型有:高空槽东移型、暖切变型、冷切变型、低涡东移型、台风影响型,各类型暴雨在各月分布差异较大;高空槽型降水大值点基本都在槽南侧辐合条件最好、且西南气流辐合条件最好的地点;冷切变型和暖切变型降水大值点在切变南侧西南气流辐合条件较好,且西南气流与地形夹角较大站点,低涡型暴雨降水大值点处在低涡南侧或低涡中心附近,西南气流与地形夹角较大站点,台风影响型暴雨由于台风自身云系深厚,螺旋云带区域降水量较大,大值点一般在与台风东部象限风向交角最大站点;地形引起的上升速度使得对流发展引起降水,也能够作为中小尺度的强对流系统的触发机制,造成不稳定能量的释放,在山区的迎风坡暴雨频次数增加,暴雨量增大;利用vb语言开发暴雨个例显示平台,对暴雨研究与预报有重要意义。     

小尺度台风暴雨灾害情景风险研究——以福州市琅岐镇为例

自然灾害和人文灾害的相互作用下,灾害发生频率、强度及其造成的损失率日益加剧。当前,对于台风灾害风险评估,国内没有一套统一的流程和标准,在面对小尺度台风灾害风险评估理论和方法的全面调研更是尚未进行开展。在此基础上,选定为暴雨灾害频发的琅岐镇的研究,通过对琅岐岛的实证研究,梳理提出一套基于小尺度台风暴雨灾害风险评估的过程和方法。     

说颭風

1.台风的定义台风是一种热带旋风。凡是两种不同方向的气流或是流水遇到一起,便会成功旋流。旋流转动的方向,可以作顺钟向转如图一甲,也可作逆钟向转,如图一乙。前者称为顺转,后者称为逆转。在台风范围以内,风向是逆转的。因为旋转的力量,就发生离心力。好像江河中的涡流,旋转便会使涡流中心的水凹下去,即涡心要比四边低一点。同样地,空气中的旋流,因为转动的关系,也会使中心气压降低。台风也是一种低气压。他的范围比起江河中的涡流,或是马路上能见到的旋风要大得多。江河中的涡流普通直径不过是几尺到几丈。台风的直径在热带内     

一次秋季台风暴雨的物理量诊断分析

利用NCEP分析资料、常规地面站雨量观测资料和区域中尺度自动站雨量资料,综合分析了"罗莎"台风的物理诊断量,探讨秋季登陆台风的特征和降水机制.湿位涡和螺旋度的分析结果表明:低层湿位涡对台风的移向和登陆点具有很好的指向作用,对台风的强度变化也有指导意义;在秋季冷空气侵入时,低层湿位涡的正值不稳定区是暴雨多发区域;垂直螺旋...     

变节距和定节距涡旋压缩机的量化比较

定节距涡旋压缩机作为气体循环的动力系统,在流体机械、空调通风、石油化工领域已经广泛得到使用。与其他种类压缩机相比,涡旋压缩机具有气体脉动小、效率高、可靠性高(转速可达到13000r/min)、结构紧凑、噪声小、零部件少等诸多优点。近几年,对变节距涡旋压缩机的研究已成为压缩机行业的前沿热点。本项目就是迎合了压缩机的发展方向,通过改变基圆半径,以达到改变节距的目的,利用分段曲线等微分几何理论,建立动、静涡旋盘涡旋壁的型线方程,完成对定节距涡旋压缩机的改进。然而对变节距涡旋压缩机和定节距涡旋压缩机的比较现仅限于概念上,还未进行量化对比。本文将对两者的差距实现量化,探究变节距涡旋压缩机相比定节距涡旋压缩机在各方面的优点。     

云海多姿

如果你乘坐飞机的话,就能有机会看到波涛起伏的万里云海,它覆盖在大地之上,真的好像起伏的海浪一样。气象卫星拍摄的近千千米的台风云系图片中,云墙则像水流急速汇向中心的江河里的涡旋一般,那涡旋中心便是“台风眼”,四周云带沿逆时针方向汇向台风中心。     

浙江“湿能”课题组在台风路径及暴雨预报方面初成效

台风及梅汛期暴雨是影响浙江的重大灾害性天气,常造成山洪爆发,洪水泛滥,水库倒塌,对人民生命财产危害极大。如8506号台风在玉环县登陆,狂风、暴雨使不少房屋倒塌,农田被毁,人畜伤亡,损失很大。如何作好台风及暴雨的预报,使人们早有预防,将其危害减轻到最低程度,这是摆在气象预报人员面前的重大任务。由于天气系统是宏观的,不能人为控制,目前也难以在实验室进行天气系统演变的实验(当然已有青藏高原系统和台风的一些简单模拟实验),且影响天气变化的因素极其复杂,     

卫星云图与雷达资料在克州强对流天气过程中的应用

应用常规天气图和喀什CINRAD/CC多普勒天气雷达回波资料对2017年克州境内典型区域性强降水分析。得出本次降水是以区域混合型降水为主,伴随有局地强对流降水天气过程。反射率因子很好反映出影响降水涡旋云系及外围云系上中小尺度天气系统发生、发展、消亡过程。径向速度反映出涡旋云系上更小尺度系统存在,垂直风廓线较好反映各层气流和风向风速变化。利用实时卫星云图及雷达资料,不仅可观测大范围云系分布,而且可观测中小尺度对流云团发生、发展和消散演变全过程。卫星云图云顶亮温变化与强降水有很好对应,雷达产品有助分析强降水落区,特别是速度图中逆风区相对于较强降水有1~2h提前量。     

孙吴县冰雹天气气候分析及防御建议

冰雹天气是一种严重的灾害性天气,一般而言,冰雹是在大气层结很不稳定,高空冷平流很弱的条件下,积雨云迅猛发展所产生的球状固态降雨,是中小尺度天气系统活动的结果。冰雹天气出现的范围小,时间短,但因其来势猛、强度大、并常伴有狂风暴雨,因而对农作物危害极大。雹粒降落在作物茎、叶和果实上,使作物受到损害,轻     

非均匀加速西行进入南海的台风个例的诊断分析

非均匀加速西行进入南海的台风是台风预报的难点问题之一。本文首先根据1949-2009年间CMA-STI热带气旋最佳路径数据集计算台风的移向和移速,按照文中对这类台风的定义统计后,收集到10个同等类型的台风个例。一般性统计分析结果表明:此类台风具有月分布集中、强度强、登陆概率大等特征。为了进一步了解此类台风的大气西风带环流背景特征和台风进入南海前后非均匀加速西行的成因,以0313号"杜鹃"和0814号"黑格比"两个典型台风为例,利用1°×1°NCEP再分析资料,从500hPa高空形势场、风场和涡度场这三方面入手分析。分析结果如下:(1)在台风西行过程中,一直都很强大的带状西太平洋副高或不断地非均匀加强西伸的副热带高压脊是维持台风非均匀加速西行最主要的原因;(2)台风北侧强大的偏东气流也在非均匀加强;(3)副高脊线附近的负涡度值区稳定且非均匀加强,是维持台风非均匀加速西行的主要原因之一。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.