Study on extracting method of single slope surface shape based on DEM:taking Wanzhou district of three gorges reservoir area as example

This paper focused on the extracting method of single slope shape. Applying the software of ARCGIS 9.0, DEM (digital elevation model) was established. From the DEM, topographic characters, including valleys and ridges were extracted. Some valley lines were extended in order to intersect with the ridges nearby. All slope were divided into different slope surface, which enclosed by valleys and ridges. And the slope surface shapes were defined three types, Line Slope, Upper-concave and lower-convex slope, Upper-convex and lower-concave slope, according to their functions. And the judge formula of single slope surface shape was brought forward. Taking Wanzhou District as test area, it indicates that auto-extracting method of single slope surface shape has high precision relatively. This study can provide references to the studies of region geological disasters prevention and cure.     

Improved D-IDS using the federated peer-to-peer architecture

A number of IDSs have been proposed for a networked or distributed environment. A modified D-IDS using federated peer-to-peer architecture, MCR (Multicast Reflector) and modified shaker protocol were proposed. The suggested scheme can be implemented easily and performs the information sharing between low-level IDS agents. As all users within a group monitor each other's, the common control server can perform detect intrusions with less cost and support the detection of the inside intruders.     

用重影线法求解两个平面立体的相贯线

提出了用重影线法求解两个平面立体的相贯线并判断可见性的新方法．对两条直线在某投影面上发生重影的现象进行分析，从空间角度认识其几何位置，由此得出重影线的定义．将其加以扩展，应用求解两个平面立体的相贯线的问题上，可以很快得出相贯线并判断可见性．     

镍镀层材料表面硬脂酸配合物膜的电化学和光电子能谱研究

通过加速化学和电化学腐蚀实验(LSV)比较了长链脂肪酸和杂环化合物等一系列有机缓蚀剂在镍镀层材料表面形成的配合物膜的耐蚀性,结果表明,硬脂酸在镍镀层材料表面形成的膜耐蚀效果最佳.用光电子能谱(XPS和AES)研究了配合物膜层的结构和性能,以及在金属表面的成键特征和波谱变化,探讨了配合物膜的组成、化学状态和缓蚀机理.硬脂酸分子中COO-中的氧原子与镍镀层表面发生界面反应形成硬脂酸配合物膜,膜由镍的氧化物和镍的硬脂酸配合物组成,其中Ni和O分别呈 2、 3和-2价,配合物膜的结构可表示为Ni-硬脂酸/NimOn/Ni,各元素的相对原子百分浓度(A.C.%)分别为Ni65.6%、C23.5%、O10.7%,该膜层厚度约为12.5nm.     

基于线结构光扫描点云数据的数据精简及三角网格剖分

在分析线结构光扫描点云数据特点的基础上,讨论了针对测量点云数据精简算法,包括测量基面数据精简和基于弦高-角度偏差准则的数据精简算法.介绍了散乱数据的基于Delaunay三角剖分优化准则和Liang提出的相邻扫描线之间的三角网格构建方法,并在此基础上提出了一种改进方法,基于优化准则的线结构光扫描点云数据三角剖分算法,该算法符合Delaunay的三角最优剖分.以摩托车后视镜点云数据为例的实验结果表明该方法是有效的和切实可行的.图12,参11.     

Relationship between the tropical cyclone genesis over the Northwest Pacific and the sea surface temperature anomalies

Using the tropical cyclone (TC) data derived from the Joint Typhoon Warning Center (JTWC) and the sea surface temperature data derived from the Joint Environmental Data Analysis Center (JEDAC) at the Scripps Institute of Oceanography from January 1955 to December 2000, we analyzed the relationship between the TC genesis over the Northwest Pacific (NWP) and the sea surface temperature anomalies (SSTA) over the Pacific basin. A long-term trend indicated that the highest frequency of monthly TC genesis appeared earlier and the annual genesis sum increased gradually during the last half century with some oscillations. No significant synchronous correlation was found between the NWP TC events and the SSTA over the Pacific basin, while the annual sum of TC genesis was closely related with the SSTA averaged from the first three months (January, February and March) of the year in the equatorial western and eastern Pacific and over mid-high latitudes of the North Pacific. The results implied that there are an interannual El Nio SSTA mode in the equatorial western and eastern Pacific and an interdecadal SSTA mode in the northern Pacific, which affected the TC genesis. A regression analysis between the first three-month SSTA and the annual TC sum based on two time scales was conducted. The correlation coefficient between simulated and observed TC sums reached a high value of 0.77.     

Relationship between the tropical cyclone genesis over the Northwest Pacific and the sea surface temperature anomalies

Using the tropical cyclone (TC) data derived from the Joint Typhoon Warning Center (JTWC) and the sea surface temperature data derived from the Joint Environmental Data Analysis Center (JEDAC) at the Scripps Institute of Oceanography from January 1955 to December 2000, we analyzed the relationship between the TC genesis over the Northwest Pacific (NWP) and the sea surface temperature anomalies (SSTA) over the Pacific basin. A long-term trend indicated that the highest frequency of monthly TC genesis appeared earlier and the annual genesis sum increased gradually during the last half century with some oscillations. No significant synchronous correlation was found between the NWP TC events and the SSTA over the Pacific basin, while the annual sum of TC genesis was closely related with the SSTA averaged from the first three months (January, February and March) of the year in the equatorial western and eastern Pacific and over mid-high latitudes of the North Pacific. The results implied that there are an interannual El Nio SSTA mode in the equatorial western and eastern Pacific and an interdecadal SSTA mode in the northern Pacific, which affected the TC genesis. A regression analysis between the first three-month SSTA and the annual TC sum based on two time scales was conducted. The correlation coefficient between simulated and observed TC sums reached a high value of 0.77.     

拟共形映射的唯一极值问题

拟共形映射的极值问题是拟共形映射理论中的重要课题,将考虑曲面R=U Ri(i∈I)上的极值问题,其中每个Ri为双曲Riemman曲面,Ri ∩Ri=Φ,i≠j,I为可数非空指标集.我们将把经典情形极值问题的几个重要结果推广到我们要研究的空间R上来.     

Daily variation of carbon flux in soils of Populus euphratica forests in the middle and lower reaches of the Tarim River

In order to lucubrate the daily variation of respiration in soils of Populus euphratica forests and analyze its relationship with environmental factors in the middle and lower reaches of the Tarim River, the LI-8100 instrument of soil CO2 flux system was used to measure the parameters of soil carbon flux and air temperature 10 cm above ground surface along the profiles of Usyman, Archy River, Yengisu and Karday, and the relationships between the soil carbon flux and the soil moisture content were analyzed. The nonlinear regression analysis was carried out with the software SPSS13.0. We observed that: (1) soil respiration began to be restrained when the air temperature was up to 30℃10 cm above the ground surface; (2) the rates of soil respiration under the forests of Populus euphratica were significantly different at various moisture contents, the soil carbon flux was high along the Usyman profile, which has a high soil moisture content, and it was low along the profiles of Archy River, Yengisu and Karday, which has a low soil moisture content; (3) the exponential model can be used to explain the relationship between soil respiration and air temperature 10 cm above the ground surface. The average Q10 values along the profiles of Usyman, Archy River, Yengisu and Karday are 0. 61, 0.16, 0. 22 and 0. 35 respectively, much lower than the average of the world; (4) there is a positive correlation between the soil carbon flux and the soil moisture content.     

浅谈《数学分析》中的斯托克斯公式

对于斯托克斯公式,在教材中,大都是在证明了第一项φlp(x,y,z)dx=(s)∫∫pzd$zx-(s)∫∫pydσxy之后,由同理可证得φlQ(x,y,z)dy=∫∫(s)αQαxdσxy-(s)∫∫Qzdyz及φlR(x,y,z)dz=(s)∫∫Rydyz-(s)∫∫Rxdzy然后三项相加而完成证明。在教学中,通过研究曲面的法方向及方向余弦间的关系;研究格林公式的几种情况等,笔者对这部分内容给出证明。