浅谈村民违法建房现象的成因及对策

近年来,农村违法建房现象时有发生,有些地方到了"村村点火,组组冒烟"的程度。而承担执法责任的国土、规划、城管等部门更是疲于奔命,但收效甚微。作为一名基层国土资源管理的工作人员,笔者认为当前村民违法建房有如下几个特点:     

海洋微藻间竞争研究进展

微藻是海洋生态系统中最主要的初级生产者,也是引发赤潮的主要生物[1-2].微藻之间的竞争作用是海洋生态系统的重要组成部分,对竞争机理的探讨,可进一步解释群落结构演替和赤潮发生原因,为赤潮治理提供新的思路,对海洋生态系统的修复和保护具有重要意义,竞争机理在微藻开发利用上的应用,将取得重大的经济效益和社会效益[3].     

Phylogenetic analysis of Pectinidae(Bivalvia) based on the ribosomal DNA internal transcribed spacer region

The ribosomal DNA internal transcribed spacer (ITS) region is a useful genomic region for understanding evolutionary and genetic relationships. In the current study, the molecular phylogenetic analysis of Pectinidae (Mollusca: Bivalvia) was performed using the nucleotide sequences of the nuclear ITS region in nine species of this family. The sequences were obtained from the scallop species Argopecten irradians, Mizuhopecten yessoensis, Amusium pleuronectes and Mimachlamys nobilis, and compared with the published sequences of Aequipecten opercularis, Chlamys farreri, C. distorta, M. varia, Pecten maximus, and an outgroup species Perna viridis. The molecular phylogenetic tree was constructed by the neighbor-joining and maximum parsimony methods. Phylogenetic analysis based on ITS1, ITS2, or their combination always yielded trees of similar topology. The results support the morphological classifications of bivalve and are nearly consistent with classification of two subfamilies (Chlamydinae and Pectininae) formulated by Waller. However, A. irradians, together with A. opercularis made up of genera Amusium, evidences that they may belong to the subfamily Pectinidae. The data are incompatible with the conclusion of Waller who placed them in Chlamydinae by morphological characteristics. These results provide new insights into the evolutionary relationships among scallop species and contribute to the improvement of existing classification systems.     

Seismically induced slope instabilities and the corresponding treatments: the case of a road in the Wenchuan earthquake hit region

On May 12, 2008, a magnitude 8.0 earthquake hit Wenchuan County, Sichuan Province resulted in great loss of life and properties. Besides, abundant landslides and slope failures were triggered in the most seriously hit areas and caused disastrous damages to infrastructures and public facilities. Moreover, abundant unstable slopes caused by the quake have the potential to cause damages for a considerable long period of time. The variety of these slopes and the corresponding treatments are connected with the topographical and geological conditions of the sites. It is decided to document and identify some of these major slope instabilities caused by the earthquake and their treatments. The paper shows the condition of a road in Dujiangyan through in situ explorations. The case history showed significant implications to the reconstruction of the quake-hit regions and future disaster prevention and management works.     

对虾传染性皮下及造血组织坏死病毒衣壳蛋白基因的克隆表达及抗体制备

本文根据GenBank登录的对虾传染性皮下及造血组织坏死病毒(IHHNV)的全基因组序列(NC-002190),设计出主要结构蛋白基因的相应引物,从厦门发病的对虾中,提取DNA,以此为模板,利用PCR扩增目的基因.再将目的基因分别与pGEX-6p1载体和pET-28a载体连接,构建重组表达载体pGEX-Ⅳ、pET-Ⅳ,重组子经酶切和测序鉴定后导入表达型大肠杆菌BL21,IPTG诱导表达,SDS-PAGE检测,大小约为62KDa和41KDa,与预测大小一致.将pET-Ⅳ表达重组蛋白经纯化,免疫小鼠,Western免疫印迹反应结果表明其抗体均可与pGEX-Ⅳ和pET-Ⅳ表达的蛋白发生特异性反应.本研究的结果为对虾IHHNV的快速检测及其免疫提供了研究基础.     

相手蟹属两种蟹类线粒体16SrRNA基因序列的比较

测定了相手蟹属（Sesarma）红螯相手蟹（S．haematocheir）和褶痕相手蟹（S．plicata）线粒体16SrRNA基因部分片段的序列,二者的序列长度相同,均为533bp,且A、T、G、C的含量相似,分别为198bp（37．1％）,206bp（38．6％）,84bp（15．8％）,45bp（8．4％）和200bp（37．5％）,205bp（38．5％）,81bp（15．2％）,47bp（8．8％）;二者的序列有49处差异,其中21个位点为转换、22个位点为颠换和6个缺失／插入位点。进一步对20种相手蟹属蟹类的长度为361bp的16SrRNA基因同源序列进行分析,发现AT的含量为78．6％～82．9％,明显高于GC的含量,且存有91个变异位点。从NJ树和遗传距离来看,在分布于中国的3种相手蟹中,无齿相手型（S．dehaani）和红螯相手蟹的亲缘关系最近（d=0．0151）,而它们与褶痕相手蟹的亲缘关系则较远（d=0．0924／0．09231。分布于中国的相手蟹和分布于北美的相手蟹之间存在着较大的遗传距离（差异）,表明它们之间有着较远的亲缘关系,互为单系起源。     

基于数字频率合成技术的任意波形发生器设计与应用

介绍了直接数字合成技术的原理及其在任意波形发生器上的应用,设计了任意波形发生器和多类信号的 混合发生软件.并对任意波形发生器的性能进行了测试.测试结果表明,该仪器频率信号发生准确、可靠.将该仪器用于漆包线信号传输特性分析.得到了漆包线的频率特性.     

地灾防治知多少

2008年5月12日发生的四川汶川特大地震,造成重大人员伤亡和财产损失,绐中国人民带来巨大伤痛。中国政府决定,自2009年开始,每年的5月12日为国家“防灾减灾日”。值此四川汶川特大地震发生一周年和首个“防灾减灾日”之际,本刊对地质灾害防治知识做一介绍,以使更多的人了解地质灾害,增强防灾避险意识,最大限度地减少损失。     

地震预报，路在何方？

地震到底能不能预报?汶川地震后出现了对立的声音。其实,这种对立始终存在。地震,是地壳运动的表现,是存在于客观中的自然现象。有发生发展过程,自然也就有了规律。认识了规律地震就可以预测,对于人类