RS与GIS支持下的桓仁县农村居民点景观格局与空间分布特征分析

运用RS和GIS技术以及景观分析方法,以辽东山区桓仁县各乡镇农村居民点为研究对象,选取斑块数、斑块面积、斑块密度、平均斑块面积、面积加权平均斑块分维数5个景观指数,从居民点用地、规模、形态、分离度4个方面进行景观空间格局分析;并从居民点空间分布与地形地貌、土壤侵蚀、经济发展3个方面进行居民点空间分布特征研究.结果表明:桓仁县农村居民点呈现出用地比重偏少,聚落斑块数量多、平均斑块面积小,大部分规模较小,分布稀疏零散,分维数小、斑块稳定,分离度较大的景观格局;桓仁县居民点分布与海拔、坡度均呈"倒数"关系,与土壤侵蚀呈较明显的线性关系,与经济发展关系密切.     

Nd isotopic variations and its implications in the recent sediments from the northern South China Sea

The chondrite-normalized REE distribution patterns in recent sediments from the northern South China Sea and surrounding areas are similar, with the HREE values being almost equal to or slightly higher, and the La_N/Lu_N ratio being lower, than PAAS standards. However, samples from the Xijiang River, a major branch of the Pearl River system, show opposite trends, i.e., with slightly lower HREE values and higher La_N/Lu_N ratio than PAAS. The distribution of Nd isotopes in sediments from the northern South China Sea was controlled by the Pearl River and the inshore area of South China, respectively. The volume of ε_Nd(0) from inshore areas of southern China is apparently higher than that from the Pearl River, and ε_Nd(0) values in offshore sediments and Taiwan Island are between these values. The results clearly show that ε_Nd(0) volume in the northeastern South China Sea is higher than in the southwest part of the northern South China Sea, indicating different source rock types. The main source rock of the Pearl River sediment is carbonate types and affects sediment deposition in the southwest of the northern South China Sea, while the source rock in the inshore area of southern China, mainly Mesozoic and Cenozoic granites, contributes to sediments in the northeastern area of the northern South China Sea. Due to different source rock types, the HREE values and the volume of ε_Nd(0) in recent sediments supplied by the inshore area of southern China are higher than those from the Pearl River. Over 80% of the rapidly accumulated sediments on the northern slope of the South China Sea in the southeast of Dongsha Islands area were derived from Taiwan Island and from inshore areas of South China, with only less than 20% from the Pearl River. Supported by National Natural Science Foundation of China (Grant Nos. 40276019, 40238060 and 40621063), and National Basic Research Program of China (Grant No. 2007CB819501)     

Self-assembled monolayers of stearic imidazoline on copper electrodes detected using electrochemical measurements, XPS, molecular simulation and FTIR

A type of imidazoline inhibitor was synthesized using stearic acid and diethylenetriamine (DETA) as raw materials. Self-assembled monolayers (SAMs) of stearic imidazoline (IM) were prepared on copper surface. The copper electrode modified by IM was detected by electrochemical impedance spectros-copy (EIS),Tafel polarization curves, X-ray photoelectron spectroscopy (XPS) and Fourial transform reflection spectroscopy (FTIR). The biggest inhibition efficiency for copper corrosion of IM was 99% in NaCl solution according to EIS results. The XPS results provided evidence that the IM was adsorbed on copper surface. The theoretical calculations of molecular simulation supported the experimental re-sults and showed that the IM molecules were tilted at an angle to the copper surface.     

The horizontal transmission of Cryphonectria hypovirus 1 （CHV1） is affected by virus strains

The effects of virus strains on the virus transmission in Cryphonectria parasitica were observed in this study. In laboratory assays by replicating vegetative incompatibility （vic） genotypes in independent fungal isolates, we quantified the transmission of three CHV1 viruses between isolates heteroallelic at one or two vic loci, and demonstrated that different CHV1 virus isolates determined their transmission abilities. The results suggested that using the hypoviruses with higher transmission abilities could increase the efficiencies of the biological control of chestnut blight.     

中国人实际碳酸氢根参考值与地理环境的关系研究

收集了全国各地4417例正常人的实际碳酸氢根参考值,应用SPSS统计软件,运用相关分析和回归分析的方法,研究了实际碳酸氢根参考值与海拔高度、年日照时数、年平均气温、年平均相对湿度、年降水量5项地理因素之间的关系.结果发现,实际碳酸氢根参考值与地理因素之间有显著的相关关系(F=8.574,P=0.000).运用回归分析法对实际碳酸氢根参考值和地理因素进行多元线形回归,通过回归方程计算出全国10个城市的实际碳酸氢根参考值.依据实际碳酸氢根参考值与地理因素之间的依赖关系,将全国划分为8个区.     

2008年保安族6～14岁中小学生形态发育指标的调查与分析

目的：了解保安族中小学生身体形态的现状和发育特征。方法：采用《中国学生体质健康调研手册》规定的方法随机整群抽样,以保安族主要聚居区甘肃省积石山保安族东乡族撒拉族自治县大河家镇的4所学校（初中1所、小学3所）6～14岁保安族中小学生为测试对象。对所有被试者进行身高、体重、胸围等形态指标测量和派生指标统计学分析。结果：6～14岁保安族学生的身高、体重、胸围、BMI指数和维尔维克指数均值随年龄增长而增长;胸围／身高X100指数随年龄呈U形增长特点。女生增长突增年龄较男生早一至两年。结沦：保安族6～14岁中小学生形态生长发育符合一般发育规律,但也存在一定程度的发育不均衡现象。     

二元小波紧框架的显式构造

研究了二元小波紧框架的结构,这个小波紧框架是由V1中的n个函数构成.首先给出由这n个函数生成二元小波紧框架的充分条件,并借助尺度函数给出了构造二元小波紧框架的显式公式,其次给出二元小波紧框架的分解与重构算法,并构造了小波紧框架的数值算例.     

用微波等离子体处理污染物

对微波等离子体光谱仪进行改装, 使微波等离子体反应器对污染物中的甲醛和SO₂进行降解, 实验结果表明两种物质均能得到有效去除, 并总结了放电状态、 载气流量、 类型、 进样质量浓度和pH值的改变对污染物去除效果的影响, 分析了反应过程中出现的降解趋势.     

“食物链”与生物进化

文中"食物链"所指的是物质与能量的获得与丧失关系.这种关系存在于自然界的各个方面并推动了生物的进化,其作用形式为协同进化.研究这一关系有利于合理利用资源与维持生态平衡.     

大学生心理健康与主观幸福感相关研究

目的：研究大学生心理健康与主观幸福感指标的相关。方法：采用《精神症状自评量表》（SCL-90）和《综合幸福感问卷》（MHQ）测量了107名大学生。结果：（1）幸福指数及各维度与SCL-90总均分及各维度存在显著负相关;（2）逐步回归分析显示,抑郁、恐怖和强迫可解释幸福指数的20%变异,强迫因子解释生活满意的22%变异,抑郁分别解释正性情感12%变异,负性情感11%变异。结论：心理健康指标评估应包括正负两个指标系统,抑郁是影响大学生主观幸福感的核心因素。