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1.
采用地面逐小时降水资料和NCEP FNL1° ×1°再分析资料,对给内蒙古东南部造成区域性强降水的影响因素进行诊断分析.结果表明:台风和西风槽是造成此次强降水的主要影响系统,副热带高压的稳定维持是台风北上的重要原因,高空槽携带的冷空气与台风暖湿空气结合造成赤峰北部的对流性天气;高、低空急流的耦合一方面上升运动加强,另一...  相似文献   

2.
利用区域自动站观测资料、ECMWF ERA50.25°×0.25°逐小时分析资料、FY2G云顶相当黑体亮温TBB等资料对2021年8月1日—2日07时通辽地区暴雨过程进行诊断分析,结果表明:(1)通辽市本次暴雨天气过程受台风“烟花”北上变性为温带气旋与高空槽合并的影响,主要影响系统是高空槽、高空急流、低空切变线以及台风倒槽。(2)在暴雨过程中,通辽市处于高空急流入口区右侧,上升区的抽吸作用有利于地面减压,而台风减弱成温带气旋北上为本次过程提供了水汽条件,过程期间整层大气水汽含量高。(3)强降水区与假相当位温高能舌区(能量锋区)相对应,并且上方存在不稳定层结,利于暖湿空气的辐合抬升。(4)通过对云顶相当黑体亮温TBB分析,流云团的发展对降水天气过程起到促进作用,并且强降水区域处于TBB等值线密集区。  相似文献   

3.
江瑶  冯爽  付远 《科技通报》2022,(6):24-29
利用云降水显式预报系统(CPEFS)、新一代多普勒天气雷达及探空反演资料等观测资料,采用水汽特征分析,对浙江夏季1次降水过程的增雨潜力进行研究。其中模式预报的降水落区和云带产品与实况的降水分布、云系特征及移动方向基本一致。利用该时段模式预报产品,结合平行时间的观测资料,对强降水云团和人工增雨作业目标云团的结构及物理特征进行对比分析,结果表明:实况强降水落区与具有较高的冰相和液相物质的云团相对应;在实况弱降水区域,可以通过水汽条件、上升气流、冰晶及云水混合比等气象指标判别出该区域因缺乏冰晶而导致的低降水效率;作业目标云系的发展增强与增雨作业有着较好的对应关系,且在作业后1小时内增雨效果最为明显。  相似文献   

4.
青海省短时强降水(强暴雨)特征分析   总被引:2,自引:0,他引:2  
本文利用青海省48个自动气象站2004~2006年6~9月逐时降水资料,分析了青海短时强降水(强暴雨)的降水性质、持续时间、降水范围以及时空分布特征。结果表明:青海短时强降水(强暴雨)范围小、持续时间短、局地性强并伴有雷暴和冰雹等强对流天气,系统性天气造成的短时强降水较少;短时强降水的分布明显受到地形影响,降水次数自西北向东南呈阶梯性递增趋势,在东南部有一高值中心,在青海湖以东、青海南部地区各有一个次高值中心;青海的大到暴雨天气过程主要以短时强降水(强暴雨)为主;短时强降水(强暴雨)在盛夏的7-8月出现最多,且多发生在傍晚前后。  相似文献   

5.
徐燚  张力 《科技通报》2009,25(5):570-576,604
应用卫星云图、常规观测资料、NCEP再分析资料结合浙江地形分布特征分析了台风"圣帕"期间浙江强降水的成因,并利用由NCEP再分析资料计算得到的对流参数对这次过程进行了简单的诊断分析,结果表明,一些参数对本次过程具有很好的指示作用,可以在预报台风降水中使用.  相似文献   

6.
文章利用西南区域中心所研发的SWC-WARMS数值模式预报产品和西藏地区的地面实况资料,对SWCWARMS数值模式在西藏地区的降水预报产品进行检验,分析SWC-WARMS数值模式在西藏地区灾害性天气过程的预报能力,通过检验分析得出以下结论:(1)SWC-WARMS模式降水产品对西藏夏季强降水和灾害性天气过程的具有一定的预报能力,尤其是对25mm以下的降水落区较好,对超过25mm以上的强降水落区预报范围偏大。(2)SWC-WARMS模式降水产品对西藏冬季强降雪和灾害性天气过程的预报能力较好,尤其是对西藏南部边缘地区的暴雪过程预报效果较好,对小到中雪的预报落区预报范围偏大。  相似文献   

7.
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。  相似文献   

8.
运用NCEP/NCAR 0.5°×0.5°再分析格点资料,台风报文资料,从大尺度环境场、越赤道气流、台风扰动能量频散等方面对1013号台风鲇鱼进入南海后出现路径突变转向的物理原因进行深入分析。研究结果表明:(1)"鲇鱼"台风进入弱环境场后转向关键区内局地风场的变化与台风自身相互作用对台风路径突变有重要影响;(2)台风转向前期越赤道气流的加强对于转向区内的风向变化有积极作用,并且这种作用从对流层低层850 h Pa至中层500 h Pa随高度逐渐增强;(3)台风处于弱环境流场中时,台风运动有沿其自身扰动能量频散形成的波列传波方向移动的趋势。  相似文献   

9.
陈晔峰  杨明  赵放  陈晴  高祝宇  肖云  张晓冬 《科技通报》2019,35(1):49-53,59
为了扩大浙江区域降水观测范围至海上区域,以浙江省研发的雷达定量估测降水(ZJ-QPE)为海上区域产品,以基于自动气象站观测的逐10分钟小时降水量作为地面观测产品,采用了克里金(Kriging)插值方法对二者进行融合试验,生成了浙江区域10分钟、0.01°×0.01°分辨率的高分辨率降水量融合产品。本文分别从产品误差的时空分布特征的融合效果以及对强降水过程监测能力等方面,对比评估了融合降水的产品质量。结果表明,该方案在陆地区域(存在站点)的地区能较好地保留地面观测信息,在海洋区域(雷达格点)则保留雷达反演的降水信息,最终形成了一套覆盖浙江及周边区域的高时空分辨率的降水格点场。  相似文献   

10.
为了探讨不同环境条件造成青海乐都两次短时强降水的原因,本文以发生在青海乐都的两次降水过程,即2014年6月3日区域对流性降水和2014年7月25日单点对流性降水为例,利用常规观测资料、NCEP 1°×1°再分析资料,对比分析环境条件。结果表明:1."6.03"和"7.25"短时强降水天气过程环流形势分别为冷槽型和西北气流型,高空槽携带的正涡度平流及冷平流为短时强降水提供了有利条件,地面干线是短时强降水天气触发机制;2.低槽、切变线、地面辐合线、地面干线、高位涡中心叠置区与强降水区有较好的对应关系;3."6.03"和"7.25"过程层结特征阈值:850h Pa和500h Pa假相当位温差17℃以上,总指数44,威胁指数166以上,假相当位温大于366K,抬升凝结高度747m以上,对流有效位能857 J/kg以上,锋生条件84以上;4."6.03"区域性对流降水所需的水汽条件和动力条件高于"7.25"单点对流性降水,而"7.25"单点对流性降水热力条件好于"6.03"区域性对流降水,单点强降水需要储存较高的热量才能触发强对流天气。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
<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  相似文献   

19.
<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  相似文献   

20.
<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.  相似文献   

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