Influence of long-period pesticide force on genetic polymorphism of wolf spider Pardosa pseudoannulata (Lycosidae: Araneae)

Wolf spiders are predators in large quantities in the fields. How wolf spiders keep their dominant species status under long-period pesticide force? To answer this question, eight geographical populations of Pardosa pseudoannulata were used as materials to test the influence of geographical habitats on their genomic DNA polymorphism. The RAPD pattern showed polymorphic variations among and within different populations. Total 84 bands amplified by 10 random primers, of which 62 (73.81%) are polymorphic, were generated from 55 individuals of eight geographical populations. Meanwhile, Shannon’s index (Ho= 0.5177) showed a rich genetic diversity of P. pseudoannulata, and most of the genetic variation (64.24%) was found within populations. Multiple regression analysis suggested that it is the climatic variation (such as annual average temperature etc.) that results in adaptive eco-geographic differentiation, and it is the long-period pesticide force that speeds up the genetic differentiation of P. pseudoannulata which changed the genetic diversity of the population.     

改性纳米碳酸钙补强NR/SBR/BR并用胶的表征

通过固相法在硬脂酸改性商品纳米碳酸钙CCR中加入间苯二酚与六亚甲基四胺的络合物RH,制备了改性纳米碳酸钙M-CCR,并分别制备了天然橡胶/丁苯橡胶/顺丁橡胶并用胶与M-CCR和CCR的复合材料.利用橡胶加工分析仪(RPA)和透射电子显微镜(TEM)研究了M-CCR和CCR在并用胶基体中的分散性、界面结合力、加工性能和形态.同时比较了复合材料的力学性能.结果表明,并用胶填充M-CCR的加工性能、补强作用以及填料的分散性和界面结合力均明显优于CCR.     

Scanning for sisnatures of geosraphically restricted selection based on population genomics analysis

Natural selection, as the driving force of human evolution, has direct impact on population differentiation. However, it is still unclear to what extent the genetic differentiation has been caused by natural selection. To explore this question, we performed a genome-wide scan with single nucleotide polymorphism （SNP） data from the International HapMap Project. Single locus FsTanalysis was applied to assess the frequency difference among populations in autosomes. Based on the empirical distribution of FsT, we identified 12669 SNPs correlating to population differentiation and 1853 candidate genes subjected to geographic restricted natural selection. Further interpretation of gene ontogeny revealed 121 categories of biological process with the enrichments of candidate genes. Our results suggest that natural selection may play an important role in human population differentiation. In addition, our analysis provides new clues as well as research methods for our understanding of population differentiation and natural selection.     

From deep basin gas to diagenetic trap—An example from the Yulin Gas Field in the Ordos Basin

In the updip portion of the Yulin Gas Field in the Ordos Basin, there are no any structural, stratigraphic and sedimentary lithologic seals. Using thin-section petrography, ultraviolet fluorescence microscopy, micro-thermometry and Raman microspectrometry, this paper finds out the diagenetic trap and studies the diagenetic history of this field. It was revealed that three phases of diagenesis and hydrocarbon charging happened in late Triassic, late Jurassic and the end of early Cretaceous respectively. In the first two phases, acid geofluid entered the reservoir and caused dissolution and cementation. Although the porosities had been increased, further compaction accompanying re-subsidence resulted in tight sandstone and conglomerates. Till the end of the early Cretaceous, bulk of gas migrated into the tight reservoir. Cementation, however, kept on in the updip portion of this field due to low gas saturation and formed the diagenetic trap. The mechanism for gas accumulation was changed from deep basin gas to diagenetic trap, which offers a sealing condition that can retain gas for much longer time.     

额田王咏秋风歌之语象溯源

古代中日两国吟咏爱情的诗歌中，“秋风”一词时有所见。从日本最早的古典和歌大成《万叶集》中所记载的、由女歌人额田王所咪的“思近江天皇咏秋风歌”可知，它与中国六朝闺怨诗既有联系又有区别，“秋风”语象在当时的中日诗歌中具有不同的意蕴。     

CRC算法在计算机网络通信中的漏检分析

在计算机网络通信中,为了降低数据通信线路传输的误码率,可以采用一种差错检测控制——循环冗余码验(CRC).介绍了CRC算法的原理、CRC算法的校验规则、CRC算法分析、CRC算法的漏检分析.     

天然气水合物渗流特征及其描述

天然气水合物渗流是一个多相多组分非等温的物理化学渗流过程,这个过程包含了相变、能量变化以及储层介质的物理性质的变化。提出了天然气水合物藏孔隙度、渗透率、饱和度等参数的定义方式。应用渗流力学理论,结合水合物开采方式,对其渗流过程进行了描述,建立了天然气水合物藏开采的基本数学模型,并探讨了目前天然气水合物渗流研究存在的问题,为下一步天然气水合物藏的物理模拟和数值计算提供了理论基础。     

再生橡胶改性高强混凝土性能试验研究

以废轮胎橡胶粉作为改性材料，研究了橡胶粉含量和细度对高强混凝土密度、坍落度、抗压强度、劈裂抗拉强度和抗折强度的影响。研究表明：随着橡胶粉掺量的增加，橡胶粉高强混凝土材料的密度、坍落度、强度会下降。橡胶粉的粒径对高强混凝土的抗压强度、抗折强度影响不明显，但劈裂抗拉强度就随着橡胶粉粒径的增大而下降。     

氯丁橡胶/丁基橡胶的成形工艺研究

选用CR1211和IIR1751为生胶原料,以氧化锌/氧化镁和硫磺为硫化体系,二氧化硅和白炭黑为补强剂,经混炼、硫化等加工过程,研究了CR1211和IIR1715并用橡胶的成形工艺。结果表明,当IIR投料顺序在先时,混炼较容易,硫化胶的力学性能优异,稳定性好,当CR1211和IIR1715投料比为1∶1时,硫化橡胶强度和热性能都较好。同时还发现,硫化橡胶强度随硫化温度升高而下降,合适的硫化条件为160℃,10.5 min。     

化学势相关问题的剖析和讨论

文章根据全微分和欧拉定理，分析了关于化学势在不同状态参量情况下的各种推导，讨论了化学势的定义式；结合吉布斯函数判据和广义功的方法，分析了相变过程，讨论了吉布斯函数的物理意义。