应用Fuzzy聚类分析划分耕地类型的研究

划分耕地类型是土地利用现状调查中的基本问题.本文对 Fuzzy 聚类分析在划分耕地类型区中的应用作了初步研究,并用此法将乐至县的耕地划分为5大类型,改进了传统的综合区划法.     

完整与非完整力学系统的积分变分原理的Riemann形式

非完整力学系统的Hamilton变分原理,有三种形式:ГеΛбзр,Воронец及Суспоъ。本文在引进3N维Euclid基本空间的二阶切空间及Riemann空间中,提出一、二阶非完整力学系统的积分变分原理的Riemann形式。推广势函数V。指出二阶非完整力学系统的作用量,才与完整力学系统的Hamilton作用量一样,具有稳定值。举了例题。     

人发中钙、镁的原子吸收光谱测定的干扰及其消除

本文研究了不同量的K,Na,Al,SiO_3~(2-),PO_4~(3-),SO_4~(2-)对火焰原子吸收光谱测定人发中Ca,Mg含量的影响.结果表明Al,SiO_3~(2-)对Ca,Mg的吸收值,PO_4~(3-)对Ca的吸收值,有负干扰,加入La(Ⅲ)或Sr(Ⅱ)可消除干扰.其余元素皆无影响.测定出人发中Ca,Mg含量的变动系数(n=10)及回收率(n=9)分别为3.4～5.9％,1.5～2.9％和93.1～100.8％,93.9～105.9％.     

矩阵分光光度（CPA）法同时测定痕量铜,铋,铁

以金属离子Ｍ,２－（３,５－二溴吡啶偶氮－２）－５－二乙氨基苯酚（３,５－ｄｉＢｒ－ＰＡＤＡＰ）和聚乙二醇辛基苯基醚（ＯＰ）的三元络合物为显色体系,用矩阵分光光度（ＣＰＡ）法研究了共存痕量铜、铁、铁３元素的测定,并对实际铅锭样品中的痕量杂质进行了测定,得到了较满意的结果。     

一种快速高精度立体视觉光条匹配算法

提出一种用于视觉检测的快速高精度立体匹配算法,利用投影和透视变换理论以及矩阵转换知识建立了摄像数学模型及双目视觉传感器模型,并给出摄像机模型中各种参数的求解方法;在外极约束理论的基础上,提出了外极斜率匹配方法,从而实现空间光条快速精确匹配。实验取得了令人满意的结果,并且该项技术已成功地应用于国家“８６３”重点攻关项目。     

固体氧化物燃料电池阴极材料 La_(1-x)Sr_xMnO_3 研究

固体氧化物燃料电池以其高效、低污染等优越性被认为是未来很有希望的发电方式,越来越受到广泛关注,Ｌａ１－ｘＳｒｘＭｎＯ３材料是目前最受重视的阴极材料。该文采用固相反应法合成了该材料粉末,对合成反应工艺参数进行了优化。采用四电极法在空气中测定了材料的电导性能,测试温度为室温到１０００℃,测试结果表明：电导率随Ｓｒ掺杂比例增加和温度升高而增大,随孔隙率的增加而变小。还对材料Ｌａ１－ｘＳｒｘＭｎＯ３晶体结构和烧结性能进行了研究。     

导向剂室温老化合成低硅X型沸石

利用导向剂室温(15～30℃)老化后高温晶化合成低硅X型沸石(LSX),用XRD测定样品晶型.对导向剂作用的研究表明,加入老化5h的导向剂17Na2O.6SiO2.Al2O3.250H2O可抑制LSX样品中的羟基方钠石(HS)杂晶,但没有加快LSX反应体系的晶化速度.对原料配比和反应条件的研究表明,产物对H2O/(Na2O K2O)摩尔比和Na2O/(Na2O K2O)摩尔比非常敏感,稍有变化就会引起杂晶的生成;随着室温老化和晶化温度的升高以及时间的延长,样品LSX结晶度增大.室温(25～30℃)老化12h、110℃晶化3h合成的LSX结晶度好、纯度高,Si/Al摩尔比为1.02±0.03.     

The diploid genome sequence of an Asian individual

Here we present the first diploid genome sequence of an Asian individual. The genome was sequenced to 36-fold average coverage using massively parallel sequencing technology. We aligned the short reads onto the NCBI human reference genome to 99.97% coverage, and guided by the reference genome, we used uniquely mapped reads to assemble a high-quality consensus sequence for 92% of the Asian individual's genome. We identified approximately 3 million single-nucleotide polymorphisms (SNPs) inside this region, of which 13.6% were not in the dbSNP database. Genotyping analysis showed that SNP identification had high accuracy and consistency, indicating the high sequence quality of this assembly. We also carried out heterozygote phasing and haplotype prediction against HapMap CHB and JPT haplotypes (Chinese and Japanese, respectively), sequence comparison with the two available individual genomes (J. D. Watson and J. C. Venter), and structural variation identification. These variations were considered for their potential biological impact. Our sequence data and analyses demonstrate the potential usefulness of next-generation sequencing technologies for personal genomics.     

High precision topographic data on Lop Nor basin＇s Lake ＂Great Ear＂ and the timing of its becoming a dry salt lake

High precision elevation measurements using DGPS were carried out along three representative tran-sects for the ＂Great Ear＂ area, a dry salt lake within the Lop Nor basin. Results indicate that the Lop Nor basin is only 5.2 m deep and its lowest point occurs at the center of the ＂Great Ear＂. In addition, the basin is asymmetric-steeper in the southwest （0.19‰） and gentler in the northeast （0.09‰）. Points along the same ＂Great Ear＂ ring were found to have an identical elevation value, but different when from different ones （lower towards the center）. The spacing of the ＂Great Ear＂ rings was found to be closely related with the surface steepness. The closer the ＂Great Ear＂ rings are spaced, the steeper the ground surface, and vice versa. These findings support the argument that the ＂Great Ear＂ rings are the former shoreline trails left behind by Lop Nor water during the last few episodes of recession towards its total dry up. A comprehensive analysis of the high precision elevation data, historical accounts, aerial and satellite photographs and imagery, and official topographic maps of the study area suggests that the ＂Great Ear＂ area in the Lop Nor basin was incorrectly mapped as being covered by a great body of water on the 1963 topographic maps. A re-interpretation of the 1958 aerial photographs and newer remote sensing imagery indicated that the ＂Great Ear＂ ring structure was already in place in 1958 and it continued to appear on the subsequent remote sensing data without any major changes. It is estimated that lake water in the ＂Great Ear＂ area of the Lop Nor basin disappeared between the late 1930s and early 1940s.