Jaumann率型一维大变形本构关系的双曲线模型

鉴于Jaumann率型本构关系难以得到应力应变全量之间的严格解析形式,采用有限元法研究了一维大变形过程中Kirchhoff应力和Green应变之间的变化规律。首先,基于虚功原理推导了完全拉格朗日描述的大变形有限元方程,然后提出了模拟大变形本构关系的双曲线模型和割线模量处理方法。算例分析结果表明,双曲线模型能够较好地拟合大变形本构关 系。大变形计算本构关系应当考虑初始孔隙比的影响。     

Comparative mitochondrial genome analysis of Sesarmidae and its phylogenetic implications

Here, we sequenced the complete mitogenome of Parasesarma eumolpe (Brachyura: Grapsoidea: Sesarmidae) for the first time. The characteristics of this newly sequenced mitogenome were described and compared with other Sesarmidae species. The 15 646-bp mitogenome contains 13 protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and an A-T rich region. All of the PCGs are initiated by the start codon ATN and terminated by the standard TAN codon or an incomplete T. The pairwise Ka/Ks ratio analysis shows that all 13 PCGs are under purifying selection, whereas the ATP8 gene is an outlier, with pairwise comparison values ranging from neutral selection (0.000) to positive selection (1.039). The gene arrangement of P. eumolpe compared with ancestral Decapoda shows the translocation of two tRNAs (tRNA-His and tRNA-Gln), which is identical to other Sesarmidae species. Phylogenetic analyses show that all Sesarmidae species are placed into one group, and the polyphyly of Eriphioidea, Ocypodoidea, and Grapsoidea is well supported. The relationship between gaps in the QIM region and the phylogeny of Sesarmidae is analyzed. It is obvious that both the G5 (the gap between Q and I) and G6 (the gap between I and M) decrease progressively with the evolution process. These results will help to better understand the genomic evolution within Sesarmidae and provide insights into the phylogeny of Brachyura.     

谈山西地区数据共享测震资料的收集

论述了山西测震台网观测历史、地震观测报告基本情况、数据共享资料收集、整理的总体思路以及采取的措施,认为,其中一些经验对地震数据整理具有一定的借鉴作用,相关处理程序可在全国范围内推广应用。     

氯铝酸离子液体催化环己酮肟Beckmann重排制己内酰胺

以氯铝酸离子液体作为催化剂和反应介质,通过实验研制一种价格低廉且环保的环己酮肟Beckmann重排制己内酰胺的催化体系.结果表明:环己酮肟转化率和己内酰胺选择性随离子液体酸性的增强而逐渐增大,离子液体中溶解的HCl对环己酮肟Beckmann重排的影响不大;反应温度、反应时间和离子液体用量对环己酮肟Beckmann重排有着较大的影响;确定离子液体Et3NHCl-2AlCl3催化环己酮肟Beckmann重排反应的最佳条件,反应温度为100℃,反应时间为60min,离子液体与环己酮肟摩尔比为1∶1;在该反应条件下,环己酮肟转化率为99.7%,己内酰胺选择性为98.0%,己内酰胺收率为97.8%.     

土地整治规划数据库建立——以平原县为例

针对新一轮土地整治规划数据库建设的技术要求,研究了基于苍穹土地整治规划管理信息系统和质检软件进行建库的流程,包括数据库创建、数据的处理与入库、成果输出、数据库质量检查与错误处理等内容.     

东方小藤壶Chthamalus challengeri（甲壳动物亚门：无柄目）线粒体基因组：小藤壶科基因排列比较及藤壶亚目系统发育分析

藤壶是潮间带生态、幼体发育以及生物防污损研究中重要的模式生物。目前,线粒体基因组学的发展有助于从线粒体基因组水平上更好地理解系统发育关系。本研究获得东方小藤壶Chthamalus challengeri完整线粒体基因组,大小为15358bp的环状分子。与藤壶亚目其它物种相比,东方小藤壶非编码区的长度较长,而基因区的长度则相近。东方小藤壶线粒体基因组A+T含量为70.5%。现有藤壶物种的线粒体基因组中存在起始和终止密码子的变化。同属的东方小藤壶和触肢小藤壶C. antennus具有共同的基因排列。然而,小藤壶科中不同属之间却具有不同的基因排列,包括两个tRNA基因出现易位,一个基因块出现倒置。值得注意的是,与以往藤壶亚目物种不同,小藤壶属两个物种的srRNA和lrRNA基因都在重链上编码。小藤壶科中进化树的拓扑结构与基因排列证据相互支持,系统发育分析表明小藤壶科是单系群,而藤壶科和古藤壶科则是多系群。     

Comparative mitochondrial genome analysis of Varunidae and its phylogenetic implications

Complete mitochondrial genomes(mitogenomes) can indicate phylogenetic relationships, as well as useful information for gene rearrangement mechanisms and molecular evolution. Currently, the phylogenetic location of the genus Varuna(Brachyura: Varunidae) has not been well resolved mainly because of limited representatives(only two extant species). Here, we determined a new mitogenome of this genus(Varuna litterata) and added the published mitogenomes to reconstruct the phylogeny of Varunidae. The ...     

Relative stabilities of cholestadienes calculated by molecular mechanics and semi-empirical methods: application to the acid-catalyzed rearrangement reactions of cholesta-3,5-diene

The study of geochemical transformations undergone by ‘biological markers’ after their incorporation into sediments is an important field of organic geochemistry. Combined with laboratory simulation experiments, molecular mechanics calculations have been shown to be very useful to establish the reaction pathways, and to predict intermediate components and stable reaction end products, especially in the case of the acid-catalyzed isomerization reactions of steroid and terpenoid hydrocarbons. Many commercially available softwares are able to optimize (minimize) the geometries of molecules and compute some of their thermodynamical data with either molecular mechanics (MM) or semi-empirical methods of quantum chemistry. In order to verify the reliability of these methods, we have computed the relative thermodynamic stabilities of a large number of steradiene isomers with MM3 (Tripos Inc.), MM+ (HYPERCHEM^TM) and MM2 (Chem3D, CambridgeSoft Corp.) empirical force fields, and with AM1 and PM3 (HYPERCHEM^TM) semi-empirical methods. The calculation results of thermodynamic stabilities of steradiene isomers are used to explain the compounds produced by the rearrangement of cholesta-3,5-diene when treated with p-toluenesulfonic acid in acetic acid at 70°C. The end products, namely the spirosteradienes 7–8, obtained by this treatment are the most stable steradiene isomers according to all computational methods. The relative thermodynamic stabilities of cholestadienes are also consistent with the mechanism postulated for the spirosteradiene formation proceeding through a pathway including cholestadienes 2–6 as intermediates.     

基于GPS技术的基本农田土地整理测绘研究

介绍了土地整理测绘的特点和工作原理,探讨了GPS技术在枝江市基本农田土地整理测绘中的应用,验证了GPS技术在实际中的有效性和准确性.     

Tectonic reorganizations and radiolarian assemblages of the northwest Pacific continental framing of Russia

Abstract Main stages of radiolarian taxonomic evolution in the Pacific rim of Russia are discussed. The diversity and distribution of radiolarian assemblages displayed in the studied sections and their geological and tectonic setting have implications regarding paleoecological and paleo-oceanographic conditions as well as paleotectonic reconstructions. Radiolarian events show the close relationship with the tectonic rearrangements in the Pacific and in North America. The attempt to analyze paleo-oceanological aspects and major factors affecting radiolarian events is presented.