2009年11月25—27日苏州地区持续性大雾天气过程分析

结合常规观测资料对2009年11月25—27日苏州地区持续性大雾天气进行分析。分析结果表明,本次大雾天气是由辐射降温和平流作用共同引起,属于平流辐射雾。在本次大雾形成前,苏州地区的天空晴朗,温度高,出现逆温层,风场配置适合,空气湿度接近饱和,这些条件是促成此次连续性大雾天气的条件。     

石家庄雾霾天气治理

近些年,随着我国会买天气的增多,很多地区把灰霾并入雾天气一起作为灾害天气,统称为”雾霾天气”.雾霾天气引起的污染事件屡见不鲜.例如,1930年12月-5日比利时Meuse谷地的大雾天气,造成雾区近万人出现哮喘等症状,在3天内死亡60人,1952年12月伦敦著名的烟雾事件,当时伦敦上空连续四五天大雾弥漫,烟,粉尘蓄积不散,造成震惊一时的4000人死亡的严重事件.随着国内工业和经济的发展,颗粒污染问题日趋严重,因此,秋冬季节雾霾交织的天气时有发生.     

祁玉民的最后一搏？

2009年12月1日。寒冬。沈阳大雾三日。 “四年前，我来华晨（上任），也是这样的天气。”华晨汽车董事长祁玉民对《中国企业家》记者谈起了天气，皱了皱眉头。     

聚焦中国高速铁路

高速火车,被人称作有轨飞机,它不受恶劣天气的影响,不怕大雾和阴霾。每年一入冬,饱受因天气困扰而滞留机场的旅客,对此有着切肤之痛。有轨飞机的安全正点,运力之强大,使飞机无法望其项背。     

聚焦中国高速铁路

高速火车,被人称作“有轨飞机”,它不受恶劣天气的影响,不怕大雾和阴霾。每年一入冬,饱受因天气困扰而滞留机场的旅客,对此有着切肤之痛。“有轨飞机”的安全正点,运力之强大,使飞机无法望其项背。     

中国现代物流迎来大发展的曙光——第二届中国物流企业家论坛暨2004中国物流企业年会侧记

2004年12月1日,北京。这天,北京、华北乃至全国的大部分地区都遭遇了历史罕见的大雾天气,这场大雾不仅考验着北京脆弱的交通,也为这天召开的第二届中国物流企业家论坛暨2004中国物流企业年会带来了意想不到的麻烦,数位重量级的与会代表被浓雾阻隔在赴京的路上,会议组织者不得不     

恶劣天气下气象测报问题及应对措施

气象预报是人们各项经济活动的决策依据，气象预报的准确程度同人们的生活息息相关，而冰雪、雷电、大雾及暴雨等恶劣天气对气象测报有极大的影响，因此探究恶劣天气下气象测报问题具有非常重要的意义。本文主要阐述了在恶劣天气下常见的气象测报问题及处理办法，并总结了相关的应对措施，以期有效提高观测质量，保证地面气象测报的准确性。     

防电压波动技术的应用

<正>电网经常发生电压波动,电网电压等级越高,发生电压波动的影响面就越广,造成的损失就越大,尤其是在夏季雷雨、大风、大雾、冻雨等恶劣天气时,造成电压波动的几率就越高。"晃电"系     

苏州地区城市化空间格局及演化分析

基于苏州地区1984-2005年的6个时相的卫星遥感数据,从城镇实体地域扩展的视角,通过城市化强度指数,运用全局和局域空间自相关测度等方法,分析了1980年代以来苏州地区城市化强度的时相性变化、空间集聚特征的演化,以及城市化"热点区"和"冷点区"的空间分布格局等.分析得出,1980年代以来,随着苏州地区的城市化进程,其城市化格局的空间集聚性逐渐减弱;城市化发展的高值簇即"热点区"呈现出较明显空间演化和跃迁的特征;苏州地区城市化过程中的全局层面的多因素驱动、"热点"轮换和局域层面的中心辐射与梯度推进是并存的.     

2011年1月份低温雨雪天气成因分析

该文分析了2011年1月1日到2月1日环流形势及地面形势、低层气温、水汽条件等。结果表明,造成这次低温雨雪天气的主要原因是:低纬80°～90°E有弱的南支槽活动,副高位于海南以南,低纬度的配置利于南支槽前的偏南气流带来暖湿空气与冷空气在30°N附近交汇,导致独山地区出现持续低温雨雪天气。中低层的0℃线的位置,整个1月份,850hpa0℃总比700hpa0℃线的位置偏北,说明独山地区始终存在逆温层。在50°～60°N,80°～100°E一带盘据强大的冷高压,冷高中心在1050hpa以上,最大达到1060hpa,冷高压地区气温低于-30℃,为持续南下的冷空气提供充足的水汽条件,是本次低温雨雪天气的冷空气来源。     

Workfare,welfare, agency,and well-being

Workfare programs are state-instituted programs that require able-bodied persons with children of school age who wish to claim welfare payments to participate in job training programs, and, eventually, to enter the work force. The philosophy of workfare is based on the value of work and the goal of self-determination. However, as a mandatory program for welfare recipients, workfare requires of those recipients certain duties which, according to those who challenge workfare, interfere with the freedom to choose what one will do with one's life. Whether some form of workfare will be adopted as part of our national welfare system remains to be seen. What the debate about such a program suggests is that welfare, in itself, by ignoring the necessity of security and education for full human agency, neither satisfies basic needs nor prepares its recipients for any life other than that of dependency. With all its difficulties workfare nevertheless presents an alternative to welfare that, at least in theory, more closely identifies its purpose with the values of our society.     

Externalities, Indivisibility, Nonreplicability, and Agglomeration

In this paper we argue that the impact of external scale economies and diseconomies on city size is not nearly as clear-cut as it is tacitly believed in urban economics. Similarly, city-size distortions are not caused by externalities alone. Indivisibility and nonreplicability, which prevent establishing the “right” number of cities, may represent a source for city-size distortions which can be stronger than the standard resource misallocation resulting from external scale economies and diseconomies. It follows that a direct population dispersion policy is not just an inferior substitute to Pigouvian taxes and subsidies but rather a useful complement.     

Mean, median, mode

Summary This note is an attempt to avoid doing the same search for the third time. It happened twice in my life that I wished to prove that the median is located between mean and mode for certain B -distributions: first in 1953, next in 1976. For arbitrary distributions the result is sometimes referred to as F echner's theorem. Of course it does not hold in general. In order to prove the result for particular distributions one can often use an elegant theorem of T imerding . There is a nice relationship with the standardized third central moment.