线状空间数据传输的几何相似性度量算法与实验分析

 同一地物在不同比例尺或者不同来源的地图上通常存在着相似性,对于图形几何形似性度量方法的研究有利于地图编制、查询、匹配、更新。线状地物要素在地图中占有很大的比例,因此,本文以线状空间目标为例,在前人的基础上给出了线状空间数据的几何图形相似性度量模型:(1)以差异距离作为相似性特征的位置相似度;(2)以分形维数作为相似性特征的形状相似度;(3)以长度或者周长作为相似性特征的大小相似度。相对于(3)大小相似度而言,(1)位置相似度、(2)形状相似度综合考虑了几何图形整体统计的方法和局部几何特征结构。完成多尺度传输的线状空间数据几何相似性度量实验,并对数据传输量与几何相似性度量方法进行比较,实验结果表明:基于广义Hausdorff距离模型的中位数Hausdorff距离的位置相似性对于空间数据渐进性传输具有稳定性和可行性。最后,总结了本文的研究成果,并展望了该方向进一步研究的若干问题。     

MONITORING POLYNUCLEAR AROMATIC HYDROCARBONS IN SEDIMENT POREWATER BY SPMD

A new mimic biological Semi-permeable Membrane Device (SPMD) introduced for sampling organic pollutants yielded satisfactory results when it was frrst used as a passive sampler to concentrate and determine 16 kinds of polynuclear aromatic hydrocarbons (PAHs) by means of capillary GC on an HP 5890 GC-FID in coastal sediment perewater. The concentration of PAHs in sediment porewater for naphthalene(N), acenaphthlene(AL), acenaphthene (AE), fluorene (F), phenaphthene(P), anthracene(A), fluoranthene(FA), pyrene(Py), benzo[a]anthracene(B[a]A), chrysene(Chr), benzo[b] fluor- anthene(B[b]F), benzo[k]fluoranthene(B[k]F), benzo[a]pyrene(B[a]P),indeno[1,2,3,-cd]-Pyrene(I[123]P), dibenz[a,h]anthracene(D[ab]A) and benzo[g,h,i] perylene(B[ghi]P) were:50.36, under detection limits(UD), 18.19, 8.41, 8.40, 1.44, UD, 8.01, 524.15, 168.47, 50.13,123.66, 63.48, 27.40, 82.04 and 58,81 ng/L, respectively.     

Simulation of probability distributions commonly used in hydrological frequency analysis

Random variable simulation has been applied to many applications in hydrological modelling, flood risk analysis, environmental impact assessment, etc. However, computer codes for simulation of distributions commonly used in hydrological frequency analysis are not available in most software libraries. This paper presents a frequency‐factor‐based method for random number generation of five distributions (normal, log–normal, extreme‐value type I, Pearson type III and log‐Pearson type III) commonly used in hydrological frequency analysis. The proposed method is shown to produce random numbers of desired distributions through three means of validation: (1) graphical comparison of cumulative distribution functions (CDFs) and empirical CDFs derived from generated data; (2) properties of estimated parameters; (3) type I error of goodness‐of‐fit test. An advantage of the method is that it does not require CDF inversion, and frequency factors of the five commonly used distributions involves only the standard normal deviate. Copyright © 2006 John Wiley & Sons, Ltd.     

The response of CO2 flux to rain pulses at a saline desert

As the substantial component of the ecosystem respiration, soil CO₂ flux is strongly influenced by infrequent and unpredictable precipitation in arid region. In the current study, we investigated the response of soil CO₂ flux to rain pulses at a saline desert in western China. Soil CO₂ flux was measured continuously during the whole growing season of 2009 at six sites. We found that there were remarkable changes in amplitude or diurnal patterns of soil CO₂ flux induced by rainfall events: from bimodal before rain to a single peak after that. Further analysis indicated that there is a significant linear relationship (P < 0.001) between soil CO₂ flux and soil temperature (T_soil). However, a hysteresis between the waveform of diurnal course of CO₂ flux and T_soil was observed: with soil CO₂ flux always peaked earlier than T_soil. Furthermore, a double exponential decay function was fitted to the soil CO₂ flux after rainfall, and total carbon (C) releases were estimated by numerical integration for rainfall events. The relative enhancement and total C release, in association with the rain pulses, was linearly related to the amount of precipitation. According to the size and frequency of rainfall events, the total amount of C release induced by rain pulses was computed as much as 7.88 g C·m^–2 in 2009, equivalent to 10.25% of gross primary production. These results indicated that rain pulses played a significant role in the carbon budget of this saline desert ecosystem, and the size of them was a good indicator of rain‐induced flux enhancement. Copyright © 2012 John Wiley & Sons, Ltd.     

Isolation, cloning and sequencing of AFLP markers related to disease-resistance traits in Fenneropenaeus chinensis

Amplified fragment length polymorphisms （AFLP） technique was used to analyze the fingerprinting of four successive generations of Fenneropenaeus chinensis to reveal their disease-resistance traits. Some loci showed quite different genetic frequencies due to artificial selection, which implied that these fragments were putative markers related to the disease-resistance trait. We developed a simple and effective method to further characterize these AFLP fragments. Specific AFLP bands were cut directly from polyacrylamide gels, re-amplified, cloned and sequenced. Eight putative genetic markers were sequenced and their sizes ranged from 63 to 209 bp. The sequences were submitted to dbGSS （database of Genome Sequence Survey）; and the BLAST analysis showed low similarity to the function genes, indicating these markers were tightly linked to a disease-resistance trait but were not functional genes.     

The influence of the orbital eccentricity of a primary on the chaotic region

Applying the resonance overlap theory to the elliptic three-body model, it is shown that the effect of the eccentricity is to increase the size of the chaotic region.     

Describing neutron stars by the relativistic mean field theory

Neutron stars are studied in the framework of the relativistic mean field theory of interacting nucleons, hyperons, and mesons. Within the hadronic freedom, the cores of neutron stars are found to be dominated by hyperons when the density is sufficiently high. The influence of hyperon coupling constants on the transition from a neutron star to a hyperon-dominated strange neutron star is also investigated. It is found that the transition density gets its minimum value when the ratio of hyperon coupling constant to nucleon's takes the value of 0.65, and the calculated maximum mass of the neutron star is 1.4 M which lies within the range of the observational results.     

工厂化培养蒙古裸腹溞研究

采用充氧培养的方法 ,研究了不同饵料和不同盐度、光照下蒙古裸腹的生长情况。结果表明 :投喂小球藻、亚心形扁藻、等鞭金藻时蒙古裸腹的增殖率分别为 4 0 6 .6 %、377%、32 2 .2 % ,差异并不明显 ,而投喂酵母的增殖率达到 86 6 .7% ,效果显著 ;在 10～ 30的盐度范围内 ,盐度为 10时增殖最快 ,增殖率为 382 % ;自然光和遮光对蒙古裸腹的增殖率为 375 .2 %和 - 0 .6 8% ,差异显著 ,其生长和繁殖需一定的光照。     

AN ANALYSIS OF THE POLICY－MAKING IN REGULATING THE INDUSTRIAL STRUCTURE AND DISTRIBUTION IN TRADITIONAL INDUSTRIAL BASE IN MIDDLE LIAONING PROVINCE

ＡＮＡＮＡＬＹＳＩＳＯＦＴＨＥＰＯＬＩＣＹ－ＭＡＫＩＮＧＩＮＲＥＧＵＬＡＴＩＮＧＴＨＥＩＮＤＵＳＴＲＩＡＬＳＴＲＵＣＴＵＲＥＡＮＤＤＩＳＴＲＩＢＵＴＩＯＮＩＮＴＲＡＤＩＴＩＯＮＡＬＩＮＤＵＳＴＲＩＡＬＢＡＳＥＩＮＭＩＤＤＬＥＬＩＡＯＮＩＮＧＰＲＯＶＩ...