孟加拉湾风暴时空分布和活动规律统计特征

利用1945—2006年JTWC公布的孟加拉湾风暴资料,对其进行统计分析。结果表明：孟加拉湾热带气旋（下称孟湾TC）生成个数年平均约为8.12个,全年均有发生,其中2~3月最少,之后开始增加,10月达到峰值;与孟湾TC不同,孟加拉湾热带风暴（下称孟湾TS）呈双峰型分布,峰值为5月和9~10月。从孟湾TS的强度上看,达到H4标准的超级强风暴1971—1986年仅出现1次,而1987—2006年则出现了8次。孟湾TS生成位置、平均维持时间和最长维持时间的月际变化均呈双峰型分布,4~5月和10~11月为峰值。孟湾TS的生成位置10~11月峰值大于4~5月,而平均维持时间和最长维持时间则是4~5月峰值大于10~11月。孟湾TC登陆方向大部分为西北或偏西路径,占56.7%。孟湾TS登陆方向与TC有一些不同,主要差异是西北路径和未登陆次数减少,偏西和东北路径增加。由于4~5月是孟湾TS东北路径登陆的一个峰值,因此,与云南雨季开始期关系密切,对云南初夏降水影响很大。

Spatial and temporal distribution of storms and their activities over the Bay of Bengal

By statistically analyzing the storm data from the Joint Typhoon Warning Center(JTWC) over the Bengal Bay during the period 1945-2006,it is found that the yearly averaged tropical cyclone(TC) number over the Bay of Bengal is 8.12,which takes place in any month of the whole year;February and March have the fewest TC numbers.The TC numbers begin to increase starting in April and arrive at a peak in October.Differing from TC over the Bay of Bengal,the tropical storms(TS) over the Bay of Bengal has two peak periods,appear in May and in October or November,respectively.With regard to TS intensity,the super severe storm of H4 criterion appeared only one time during the period 1971-1986,but appeared eight times during the period 1987-2006.The monthly change of the original position,the averaged maintaining time,and the longest maintaining time of TS also have two peak values:They appear in April or May and in October or November,respectively.The peak value of the original position in October or November is bigger than that in April or May.The peak value of the average maintaining time and the longest main-taining time of the TS in April or May is bigger than that in October or November.TC landfall path is mostly moving toward northwest or west and accounts for 56.7 percent.The landfall path of the TS differs from that of TC in some respects.The main difference is that the numbers of the northwestern path and un-landfall of TS are less than those for TC,and the numbers of the western path and northeastern path of TS are greater than for TC.Because of the landfall TS in the north-east path has a peak,it and the beginning of the rainy season in Yunnan Province are closely related;it is on Yunnan Province's early summer precipita-tion that they have a great impact.

微库仑法及紫外荧光法测定石油产品中总硫含量的对比

针对测定石油产品中总硫的两种不同方法,即紫外荧光法测硫含量、微库仑法测硫含量,比较两种方法相近、不同之处,以便选择最有效、最经济、最环保的试验方法。为了更直观的比较两种方法,以日本三菱化成公司生产的TS-03氧化微库仑仪来说明微库仑法,以泰州市天创仪器有限公司生产的TCS-2000S荧光定硫仪说明紫外荧光法。