PROPAGATION OF 30—60 DAY LOW FREQUENCY OSCILLATIONS AND THEIR INFLUENCE UPON THE SUBTROPICAL WESTERLIES JET STREAM DURING NORTHERN HEMISPHERE WINTER

Based on daily ECMWF gridpoint data of two winters during 1981—1983 including an ENSOyear,propagation of low frequency oscillations(LFO)during Northern Hemisphere winters andtheir influences upon 30—60 day oscillations of the subtropical jet stream are studied with the sta-tistical methods as complex empirical orthogonal function(CEOF)and so on.Results show that inthe winter of a normal year(1981—1982),30—60 day oscillations in the subtropical zone aremainly in the northern and southern flanks of exit region of jet stream.In the ENSO year(1982—1983),they are mainly in the vicinity of entrance and exit regions of jet stream.Intraseasonalchanges of subtropical jet stream manifested themselves as latitudinal fluctuation or longitudinalprogression or regression of about 40 day period.There are marked differences between propagat-ing passages of low frequency modes responsible for changes of subtropical jet stream in the normalyear(1981—1982)and in the ENSO year(1982—1983).Changes of oscillation amplitude showobvious phases.In general,the one in late winter is stronger than that in early winter,strongestone occurs in February.     

南海波高熵和风速熵

根据风速的统计分布，给出了有因次风速熵和无因次风速熵的定义及其计算方法，使用ＧＥＯＳＡＴ高度计１９８６年１１月－１９８９年２月的有效波高和风速的资料，计算，分析了南海海域上的波高熵，风速熵，给出它们的时间变化特征和空间变化特征，并对不同随机量的无因次熵，即随机度进行了比较。     

Pathogens and pathogenicity to Penaeus orientalis Kishinouye

ＰａｔｈｏｇｅｎｓａｎｄｐａｔｈｏｇｅｎｉｃｉｔｙｔｏＰｅｎａｅｕｓｏｒｉｅｎｔａｌｉｓＫｉｓｈｉｎｏｕｙｅＩＮＴＲＯＤＵＣＴＩＯＮＢａｃｔｅｒｉａ，ｅｓｐｅｃｉａｌｌｙｖｉｂｒｉｏｓａｒｅｏｎｅｏｆｔｈｅｍａｊｏｒｐａｔｈｏｇｅｎｓｔｏｃｕｌｔｕｒ...     

全站仪交汇法在高速公路路面沉降监测中的应用

文章介绍了全站仪交会法沉降监测,方便简洁地解决了测量人员不能进入的高速公路等特殊位置的测量问题,并通过对该方法的精度分析,论证了其可行性和有效性,对以后类似的测量工作提供经验和依据。     

Climate changing characteristics of Zhangye City in Heihe River basin during 1968–2005

At present, researches on climate change of the Heihe River basin mainly focus on the relationship between basin climate change and regional water resources, regional desertification and dynamic climatic seasons of sandstorm, but less on climate change of oasis region, where there are more intense and frequent human activities. Based on data of precipitation, temperature, strong wind and dust events frequencies obtained from the six meteorological stations of Zhangye region in Heihe River basin, the features of climate change during 1968–2005 were carefully studied. Results show that the regional temperature rise rate exceeded the average level of China. The annual precipitation changed a little, but the precipitation had a slowly increasing trend in spring and winter. Frequencies of strong wind and sandstorm days show obviously descending trends, which had a close correlation with the regional temperature rise and the precipitation increase in spring and winter. Meanwhile, further human economic activities and exploitations to the oasis in the inland valley of arid regions also affected the climate change of this region, which has a sensitive and fragile eco-environment. __________ Translated from Journal of Desert Research, 2007, 27(6): 1048–1054 [译自: 中国沙漠]     

成都城市发展对热岛强度影响的主成份回归分析

本文对成都市总人口、建成区面积等11个因子、作了主成份回归L-S估计和M-估计,讨论了成都城市发展对“热岛”强度的主要影响因子。结果表明,城区房屋建筑面积及总人口数是影响城市气候(气温)的主要因子,其次为城市人口总户数、建成面积等。 文中,对回归方程进行了拟合计算,回归效果比较满意(尤其是稳健回归)。     

我对霰和米雪的认识与理解

在实际观测中，有时某种天气现象的特征并不典型，或某些现象之间形态有相似之处，形成条件也有共同点，容易混淆。霰和米雪就是２种容易混淆的天气现象。虽然《地面气象观测规范》根据其外形和结构做出了定义，但是，大气中的各种天气现象是非常复杂的，甚至是千变万化的。有时出现的天气现象并不象《规范》中规定的那么标准、典型，而是同时具备２种现象的某些特征，或者介于２种现象的标准之间，这就给观测识别和记录带来一些困难。如２０００年初冬我们观测到这样的天气现象：层积云产生固态颗粒降水，直径在１mm～３mm之间，下降时间为…     

西南某电站右岸倾坡内夹泥裂隙成因探讨

西南某拟建大型水电站的右岸岩体中存在倾向坡内的夹泥裂隙，通过对其的发育情况以及所处的地质环境进行系统的研究和认真剖析，认为该区内的倾坡内夹泥裂隙的成因并非正常卸荷引起，而是在构造的基础上，穹隆挽近期隆起的结果，为右岸坝肩稳定性评价提供了可靠的依据。     

节水灌溉理论与技术发展现状

水资源日益短缺是全球性的问题。农业节水潜力较大，从长远战略角度看，发展节水灌溉对缓解我国水资源的供需矛盾意义重大，本文通过节水灌溉理论研究进展情况的介绍，提出了西北地区发展节水灌溉应注意的问题。     

前兆观测中的远场效应及其成因机制的初步探讨

在近２年的前兆观测实践中，我们发现了一种十分有趣的，奇特的现象，在１９９６年３月１９日新疆阿图什６．９级强震发生前和１９９７年３￣４月新疆伽师６级强震群发生前，在远隔２５００公里外的四川地区观测到了多种前兆手段的群体突变事件。我们称它为强震的“远场效应”。本文还对它的成因机制作了初步的探讨。