3 种全球环流预报场近地层风速突变预报能力评估

本文采用Bernaola-Galvan启发式分割算法对3种全球环流预报场预报风速序列以及气象站和测风塔的实测风速序列分别进行风速突变事件的挑选,并综合挑选结果对3种全球环流预报场对我国风速突变事件的预报能力进行检验和评估.结果显示: ECMWF全球环流预报场风速突变事件的预报效果最优,其次是GFS,然后为T639,但是在青藏高原和甘肃北部地区,GFS要优于ECMWF,在我国沿海尤其是南部沿海地区,T639为最佳;ECMWF在新疆北部、甘肃北部、内蒙古中西部、河北和山西风速突变预报准确率较高,约为30%以上,其次为东北、山东、河南和江苏,约为10%~30%,其余地区预报准确率基本上在20%以下,尤其在西藏和四川大部分地区预报准确率为0,T639预报场在沿海地区的预报准确率基本在30%左右;ECMWF预报场在我国大部分地区预报相位偏差在3h以内,幅度偏差基本上在3m/s之内,仅在新疆北部、甘肃北部、青海北部、内蒙古及辽宁地区相位偏差为3~6h之间,幅度偏差大于3m/s,在新疆北部和内蒙古东部幅度偏差达到6m/s.     

格尔木地区沙尘天气过程数值模式精细化检验

利用2022年常规5 min间隔地面能见度观测资料、ECMWF及CMA-GFS模式资料,通过数理统计分析方法,对格尔木辖区内14个观测站的能见度观测资料与能见度模式预报数据进行检验分析,结果表明：（1）ECMWF模式较CMA-GFS模式能见度预报准确率稍高,ECMWF模式临近时次预报准确率较前一时次有略微提高,5 km准确率较3 km准确率高10%,总体上两种模式预报准确率均较差。（2）ECMWF模式预报值与观测值之间存在一定的线性关系,并且临近时次起报的预报值方程拟合度更高;ECMWF模式较CMA-GFS模式更接近观测值,但数值偏高,ECMWF模式的预报值存在20%左右的高估,而CMA-GFS模式存在70%左右的高估;ECMWF模式临近时次起报的预报场与观测值的离散程度更低,而CMA-GFS模式则相反。（3）从时空变化特性来看,两种模式的能见度预报值较观测值有数值偏大、时间滞后、落区偏南的特征。检验结果对提高当地能见度客观预报准确率具有重要的参考价值。     

阿尔山五里泉负氧离子预报方程的建立及检验

利用阿尔山五里泉空气负氧离子自动测报系统的实时监测数据和阿尔山气象站的气象要素观测资料,分析了负氧离子浓度的季节差异和日变化规律,采用逐步回归法筛选通过T检验的预报因子,建立了负氧离子浓度逐小时和逐日预报方程,并检验预报效果,结果表明,春夏秋季负氧离子浓度日变化趋势基本一致,均呈现夜间高,白天低的特征,最低值出现在午后14∶00;负氧离子浓度在春夏秋季与相对湿度呈显著正相关,与气温呈显著负相关,在冬季相关性较差。通过建立4个季节负氧离子浓度逐小时和逐日预测模型,实现了负氧离子预报的定量化,经检验预报方程效果显著。     

青、老年人扩张型心肌病的临床研究

探讨老年人扩张型心肌病 ( DCM)的临床特征并与青年人 DCM进行比较 .通过临床观察对 80例老年人和 140例青年 DCM的临床资料进行对比分析 .结果发现 :( 1)老年组醛固酮值( 30 4 .8± 69.1)较青年组 ( 2 13.3± 54.5,pmol/ L)明显增高 ( P<0 .0 5) ,老年组 T3和 FT3值 ( 0 .78± 0 .2 1,2 .87± 0 .73)较青年组 ( 1.2 6± 0 .33nmol/ L ,3.55± 0 .64pmol/ L )明显降低 (均为 P<0 .0 1) ;( 2 )老年组室性心律失常发生率 ( 61.3% )较青年组 ( 92 .1% )低 ( P<0 .0 1) ;( 3)老年组低血钾、低血镁发生率高 (分别为 51.3%和 2 7.5% ) ,对洋地黄敏感性增加 ,易发生洋地黄中毒( 2 8.8% ) ;( 4 )老年组的病程 [( 11.0± 4 .7)年 ]和平均生存期 [( 6.9± 4 .2 )年 ]均较青年人 [( 5.2±2 .5)和 ( 3.4± 2 .7)年 ]长 (均为 P<0 .0 5) ;( 5)老年组的主要死因是充血性心力衰竭 ( 78.9% ) ,青年组则为恶性心律失常 ( 61.9% ) .结论为老年人 DCM的预后比青年人相对要好 ;老年人 DCM常伴低 T3综合征 ;心力衰竭、电解质失衡及交感神经兴奋是老年人 DCM室性心律失常的主要原因     

ECMWF集合预报产品对浙江汛期降水的预报性能评估

利用2018和2019年汛期ECMWF集合预报系统输出的降水预报资料和浙江省内自动气象观测站的降水数据,通过RPS评分、Brier评分、可靠性分析和ROC分析等方法,评估了基于ECMWF集合预报的降水概率预报产品在浙江汛期降水中的预报性能。结果表明：(1)概率预报对多个量级降水的综合预报效果在0～24 h为最好,72 h以后开始明显变差;(2)分量级而言,概率预报对于从小雨到暴雨量级的降水都是有一定预报能力的,预报性能在1～4 d内较稳定;(3)系统对小雨的预报性能优于其他量级降水的预报,而对暴雨以上量级降水来说,预报性能迅速减弱;(4)对大雨以下量级降水,概率预报对于低频(高频)事件,给出过低(过高)的发生概率;而对暴雨以上量级降水全频率事件均出现高估。     

基于Logistic方法建立气象诱发脑卒中预警模型

基于2009年7月1日至2018年11月30日邢台市三级综合医院的脑卒中(脑梗塞、脑出血)住院患者的临床资料,结合同期13种气象要素,研究分析诱发脑卒中疾病的主要气象因素为气温、气压和风速。应用SPSS 25.0统计软件中Logistic回归方法建立分级预测预警模型,实际检验脑出血预报准确率达98.6%,脑梗塞预报准确率达99.2%,脑卒中预报准确率达95.3%。分级预警模型中脑梗塞、脑卒中发病人数大于或等于2人时预测准确率超过90%。此研究为邢台地区防治脑卒中疾病提供合理依据,为开展精细化医疗气象服务提供重要参考。     

青海省东北部汛期雷达定量预测降水分析

本文利用2005、2006年6～9月西宁C波段多普勒天气雷达基数据资料和雷达周围11个气象站自动雨量资料,通过概率配对方法建立了反射率因子Z和雨强I之间的关系,并对2007年6月14～15日发生在青海省东北部的一次区域性降水过程进行了试报,结果表明:距雷达80km范嗣以内预报准确率较高,为短时降水定量预报提供了依据.     

可用于城市空气污染预报的嵌套气象模式系统

基于区域大气模拟系统 ,采用网格嵌套方法 ,发展了由区域尺度气象模式 (R αM )和城市尺度气象模式 (C βM )组成的嵌套模式预报系统 ,为空气污染预报提供必需的气象要素场。共进行了 5组预报实验 ,并分别与对应区域和城市尺度的两类静力平衡预报模式 :Eta模式 (区域尺度 )和M βM (城市尺度 )的预报结果进行了比较研究。结果表明 ,R αM和C βM预报结果更能准确合理地反映天气系统的实际变化规律 ,其预报效果明显好于Eta模式和M βM。建立的嵌套模式预报系统可为空气污染业务预报提供一个好的工作平台     

包头市水资源供需平衡分析

1　包头市可利用供水水源状况包头市区可利用的供水水源有 :地下水资源、水库水和黄河水。包头市及近郊范围内的地下水多年平均补给资源量为 1 .2 6× 1 0 8m3/a;水库可向城市提供 5× 1 0 4 m3/d,作为城市自来水公司季节性调节水源 ;目前包头市在黄河昭君坟段和磴口段取黄河水量为 1 .5 7× 1 0 8m3/a作为城市供水 (包括包钢用水 )。综合地下水和地表水 ,现包间市区可利用的水资源量为 3× 1 0 8m3/a左右 (含 1× 1 0 8m3/a的农业用水 ,可作为城市供水资源量约为 2× 1 0 8m3/a左右 )。 1 996年城市总供水量为 2 .5 5× 1 0 8m3/a,地下水已…     

短期温度、降水的多模式集成预报

通过对T213、NCEP、JMA和德国天气在线4种模式的产品对湖州从2005年1月到2007年6月的温度、降水预报的对比分析,利用前5日和历史权重法建立了对温度、降水的集合预报方法,检验表明:集成的温度、降水预报结果优于大多数模式单独的预报结果,降水24 h、48 h定性预报准确率70%左右.前5日集成模式重要温度预报的平均绝对误差在2℃左右,并且不存在明显的系统误差,预报达到了一定的精度;同时前5日的集成方法比历史集成方法更为优越,可提高温度和降水准确率5%左右,为预报员提供更精细的客观预报参考.     

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.     

Low doses of a red wine ingredient figh diabetes in mice

Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.     

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.     

Molecular motor assembly of a biomimetic system

Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.     

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