广西沿海热带气旋暴雨分析

利用1954-1998年的资料,以统计分析的方法,对广西沿海热带气旋暴雨与热带气旋生成地区、路径和天气形势的相互关系进行初步探讨,归纳出几点有价值的结论.     

多年冻土区路堤边坡上遮阳板的稳定性分析

在青藏铁路和青藏公路的施工建设中,许多主动保护冻土的措施已经被采用,遮阳板就是其中有效的降温措施之一.由于青藏高原风速较平原地区大,且会对建筑物造成一定的破坏,所以文章以高原平均风速最大的地区-安多地区的风速条件为例对遮阳板的稳定性进行数值试验,从而得出合理的遮阳板的结构参数,为今后施工和维护提供了科学依据.     

组合GPS/测距测向仪车载导航和卡尔曼滤波

讨论了ＧＰＳ单点伪距定位的特点,然后利用距测向仪来弥补ＧＰＳ导航的不足以及提高导航精度,并给出了确定初值的一种迭代算法,最后提出了八状态的卡尔曼滤波器。     

Standing stock of phytoplankton and primary productivity in Penaeus orientalis larval multiplication releasing area of the Xiangshan Bay

INTRODUCTIONTheXiangshanBayisoneoftheimportantmarineaquaculturebasesinZhejiang.Since1982,themultiplicationreleasingexperimentsofPenaeusorzentalisKishinouyelarvalhavebeencarriedoutinthebay.Thestudyonthephytoplankton,chlaconcentrationandproductivityandthelifepatternofreleasedlarvaeprawnintheXiangshanBayisoneoftheimportanttasksoftheNationalKeyProject--AquaticExploitationTechniqueResearchinLakesandHarbors.TherearemanylargebaysandharborsalongChina'scoast,butonlyafewobservationshavebeend…     

翡翠贻贝软体部营养成分的研究

分析了翡翠贻贝Pernaviridis软体部的营养成分。其中蛋白质及氨基酸含量较高 ,必需氨基酸占总氨基酸量的 33 2 %。粗脂肪和脂肪酸含量丰富 ,特别是EPA和DHA总量占总脂肪酸的 2 6 0 1 %。除富含Ca,Mg ,Fe等无机元素外 ,Se的含量也较高。     

振动系统的逆与优化问题(Part-Ⅱ)部分边界值再构内部场(Ⅰ)理论

研究由一振动体的部分边界测量数据再构振动体内部场的逆问题.提出基于偏微分方程控制方法的一种算法,并证明原用于处理散射问题的Null-field method 可用来求解优化问题的随伴问题.     

静动载下共面非贯通裂隙贯通机制分析

共面非贯通裂隙的贯通机制对于确定外载下岩质边坡的滑动面位置及滑动面综合抗剪强度至关重要。采用预制共面非贯通裂隙石膏模型试样单轴静动载对比试验,对不同裂隙倾角共面排列裂隙的扩展、贯通过程进行了观测,研究显示：共面非贯通裂隙不同倾角下的贯通模式存在较大差异,裂隙倾角为0o～35o时以裂隙面发生闭合变形为主;45o～65o时裂隙间较易出现剪切型破坏模式;75o～90o预制裂隙面较难产生滑动,裂隙试样主要产生劈裂形式的破坏。动载下预制裂隙试样裂尖翼裂纹及次生共面裂纹起裂后易朝原起裂方向快速发展;易在两预制裂隙内端部产生直接贯通,这与静载下岩桥处的贯通常通过分支裂纹拐折扩展、相连不同。含共面非贯通裂隙试样在裂隙倾角为35o左右时强度呈现最小值,这与贯通性裂隙试样裂隙倾角为60o左右呈现最小值相差较大,这是因为裂隙面摩擦强度没来得及发挥作用所致。因此,含非贯通节理裂隙岩体的综合抗剪强度公式应引入强度发挥系数,以充分考虑岩桥胶结强度与裂隙面摩擦强度不能同步发挥作用的破坏本质。     

洞室岩体参数的位移正演反分析

岩体的某些参数,如弹性模量、强度参数等,对地下洞室的施工和设计具有极其重要的作用。直接进行这些参数的现场测量势必要耗费大量的物资和精力,但结果不一定令人满意。在这种背景下,位移反分析的工程应用具有很重要的理论和实用价值,它克服了直接测量岩体参数所带来的弊端,仅用工程中较易得到的位移量就可以反演出岩体的这些参数。笔者应用位移正演的方法,结合石碑岭隧道这一具体工程进行了岩体参数的反演计算。     

Spatial and temporal variations in pH and total alkalinity at the beginning of the rainy season in the Changjiang Estuary, China

The results of field observation carried out in May 2003 were used to examine pH and total alkalinity behaviors in the Changjiang Estuary. It was showed that pH and total alkalinity took on clear spatial variations in values with the minima in the low salinity region. Like salinity, transect distributions of pH and total alkalinity （TA） in a downriver direction had a sharp gradient each. These gradients appeared in such a sequence that the TA gradient was earlier than salinity and pH gradients, and the salinity gradient was earlier than the pH gradient. These distribution characteristics seemed to be strongly influenced by the mixing process of freshwater and seawater, for both pH and total alkalinity had significant linear relationships with salinity and temperature. For pH, phytoplankton activities also had a significant impact upon its spatial distribution. During a period of 48 h, pH and total alkalinity changed within wide ranges for every layer of the two anchor stations, namely, Stas 13 and 20, which were located at the mixed water mass and seawater mass, respectively. For both Stas 13 and 20, pH and TA fluctuation of every layer could be very wide during a 4 h period. As a whole, the data of the two anchor stations showed that neither variations in salinity and temperature nor phytoplankton activities were the main factors strongly influencing the total alkalinity temporal variability on a small time scale. The data of Sta. 20 implied that both salinity variation and phytoplankton activities had a significant influence on pH temporal variability, but the same conclusion could not be drawn from the data of Sta. 13.     

盐藻的一种盐诱导碳酸酐酶基因转录起始点的确定及表达载体的构建

采用5′RACE和巢式PCR的方法确定盐藻(Dunaliella salina)一种盐诱导碳酸酐酶基因的转录起始位点,通过序列分析得出转录起始位点为A,从而确定核心启动子及上游调控区的位置。应用巢式PCR技术分别扩增盐藻这种碳酸酐酶基因上游调控区的2个片段,长度大约分别为0．8和1．2kb,序列经测定无误后分别与带β-葡糖苷酸酶(GUS)报告基因的载体相连接,经酶切鉴定这两种表达载体构建正确。用基因枪法将这两个载体导入盐藻细胞中,经染色检测,GUS基因在转化藻株中得到瞬时表达。