放牧对浑善达克沙地丘间低地植被群落及土壤的影响

为探究放牧对丘间低地植被群落及土壤的影响,分析了浑善达克沙地丘间低地在重度和轻度放牧下植被的地上生物量、物种重要值、物种丰富度、Shannon-Wiener多样性指数、Pielou均匀度指数、Simpson生态优势度指数及0~10 cm土壤中黏粒、粉粒、砂粒、有机碳和全氮含量。结果表明：（1）植被地上生物量、土壤黏粒、粉粒、砂粒、土壤有机碳和全氮含量在不同放牧程度下存在极显著差异（P<0.01）,物种丰富度、Shannon-Wiener多样性指数和Pielou均匀度指数在不同放牧程度下差异不显著（P>0.05）,Simpson生态优势度指数在不同放牧程度下差异显著（P<0.05）。（2）放牧区植被以禾本科为主,禾本科植被地上生物量占整个植被群落的54.88%~57.76%;重度放牧区植被地上生物量为63.59 g·m^-2,比轻度放牧区低26.61%。（3）羊草（Leymus chinensis）和狗尾草（Setaria viridis）是放牧区的优势种,其重要值依次为14.16%（重度放牧区）和19.10%（轻度放牧区）、13.40%（重度放牧区）和15.42%（轻度放牧区）,重度放牧下雾滨藜（Bassia dasyphylla）、克氏针茅（Stipa krylovii）和猪毛蒿（Artemisia scoparia）的重要值较显著高于轻度放牧区,而羊草则低于轻度放牧区。（4）重度放牧加剧了土壤沙漠化,使砂粒含量增加,草地生产力下降,土壤有机碳和全氮含量降低。     

浅谈测绘监理在第三次国土调查中的运用 ——以益阳市第三次国土调查监理为例

从1988年建设部颁布《关于开展建设监理工作的通知》算起,在我国工程建设领域推行工程监理制度已有三十多年历史.工程监理在工程建设过程中发挥了重要作用,我国目前在工程领域建立了完善的监理法规及标准体系,形成了较为完整的工程监理机制.但在测绘领域,全面推行测绘监理仍尚需时日,有待健全.湖南省各市州第三次国土调查项目引入了监...     

Methods Comparison for Microsatellite Marker Development： Different Isolation Methods, Different Yield Efficiency

Microsatellite markers have become one kind of the most important molecular tools used in various researches. A large number of microsatellite markers are required for the whole genome survey in the fields of molecular ecology, quantitative genetics and genomics. Therefore, it is extremely necessary to select several versatile, low-cost, efficient and time- and labor-saving methods to develop a large panel of microsatellite markers. In this study, we used Zhikong scallop (Chlamys farreri) as the target species to compare the efficiency of the five methods derived from three strategies for microsatellite marker development. The results showed that the strategy of constructing small insert genomic DNA library resulted in poor efficiency, while the microsatellite-enriched strategy highly improved the isolation efficiency. Although the mining public database strategy is time- and cost-saving, it is difficult to obtain a large number of microsatellite markers, mainly due to the limited sequence data of non-model species deposited in public databases. Based on the results in this study, we recommend two methods, microsatellite-enriched library construction method and FIASCO-colony hybridization method, for large-scale microsatellite marker development. Both methods were derived from the mi-crosatellite-enriched strategy. The experimental results obtained from Zhikong scallop also provide the reference for microsatellite marker development in other species with large genomes.     

BTEX异常对海域油气藏指示作用的研究

常规的油气化探方法一般是应用烷烃类作为油气勘探的基本指标,但是烷烃类易受人类活动和生物活动的干扰,使常规的化探技术在油气勘探中一直受到限制。人们开始考虑采用直接的生物标记化合物来预测油气藏,如芳烃系列中的苯系化合物苯(benzene)、甲苯(toluene)、乙苯(ethylbenzene)、二甲苯(xylem),简称BTEX。国内外研究表明,BTEX基本不受人类活动和生物活动的干扰,对油气藏具有良好的指示作用。依据南海某区的实测资料,采用自主研发的油气化探可视化评价软件进行数据处理,剥离背景异常,圈出有效的BTEX异常,并与靶区地层剖面进行了对比,结果证实了BTEX对海域油气藏具有良好的指示作用。     

钻井柱状图可视化查询系统的设计与实现

钻井柱状图是石油行业勘探开发最常用的一种图件。为了开发出灵活通用的钻井柱状图制作软件,为可视化分析提供良好基础,提出了“两库四类三层”系统设计方案,应用COM思想和模板定制技术,采用C#．net语言从底层进行了软件实现,所开发的软件模块具备一定的独立性和较好的通用性。     

Hematological changes in white spot syndrome virus-infected shrimp, Fenneropenaeus chinensis (Osbeck)

The pathological changes of hemocytes in the haemolymph and hepatopancreas were examined in experimentally and naturally WSSV (white spot syndrome virus) infected Fenneropenaeus chinensis. The results showed that the pathological manifestations of hemocytes were similar among moribund shrimps infected via injection, feeding and by nature. Firstly, the total hemocyte counts (THCs) in WSSV-infected shrimp were significantly lower than those in healthy shrimp. Secondly, necrotic, broken and disintegrated cells were often observed, and a typical hematolysis was present in the haemolymph smear of WSSV-infected shrimp. Thirdly, necrosis and typical apoptosis of hemocytes were detected with TEM in the peripheral haemolymph of WSSV-infected shrimp. Hyalinocytes and semi-granulocytes with masses of WSSVs in their nuclei often appeared, whereas no granular hemocytes with WSSV were found in the hepatopancreas of moribund infected shrimps. All our results supported that hemocytes were the main target cells of WSSV, and hyalinocytes and semigranular hemocytes seemed to be more favorable for WSSV infection in F. chinensis.     

乳山湾邻近海域波浪特征要素规律研究

基于高分辨率MASNUM第三代海浪模式并根据Yuan等(2009)提出的波浪破碎统计物理模型,对乳山湾外海2008年各个季节波浪特征要素(有效波高和跨零周期等)与波浪破碎参数(白冠覆盖率、卷入深度和破碎能量损耗率)进行了数值模拟。利用Janson-1卫星高度计观测资料对有效波高模拟结果进行了检验,平均误差在0.17m左右。模拟结果显示,该海域波浪参数具有明显的季节变化特征,在2008-08乳山湾邻近海域受大风天气过程影响期间,有效波高在1.0~1.8m,破碎参数变化显著,白冠覆盖率最大达4.5%,卷入深度在1.5m以上,相应的破碎能量损耗率量值在6~11kg/s3。结果表明,波浪破碎过程对该区域海洋动力环境有着重要影响,是造成乳山湾口表层高溶解氧的可能机制之一。     

长江口表层沉积物矿物磁性分区特征及其沉积环境指示意义

本研究旨在揭示现代长江口不同沉积环境铁磁性矿物的分布差异,寻找有效识别河口-陆架沉积环境的磁学指标,以便更好地将环境磁学应用于河口古环境研究。在长江口及邻近陆架的6个沉积环境:汊道、拦门沙、三角洲前缘斜坡、前三角洲、前三角洲-陆架过渡区和残留砂区,采集表层沉积物样品,进行粒度和磁性测量。结果显示,χ和SIRM在汊道和拦门沙呈现显著高值,HIRM、χfd%、χARM、χARM/χ和χARM/SIRM在前三角洲和前缘斜坡呈现显著高值,反映了陆源物质输运距离和河口沉积动力对磁性矿物分布的控制作用。因此,参数组合HIRM、χARM、χARM/χ和χARM/SIRM可用于识别全新世地层前缘斜坡和前三角洲-陆架;参数组合χ、SIRM和S-20mT可尝试用于识别汊道和拦门沙环境。     

Effects of the seasonal variation in chlorophyll concentration on sea surface temperature in the global ocean

The effects of biological heating on the upper-ocean temperature of the global ocean are investigated using two ocean-only experiments forced by prescribed atmospheric fields during 1990–2007, on with fixed constant chlorophyll concentration, and the other with seasonally varying chlorophyll concentration. Although the existence of high chlorophyll concentrations can trap solar radiation in the upper layer and warm the surface, cooling sea surface temperature (SST) can be seen in some regions and seasons. Seventeen regions are selected and classified according to their dynamic processes, and the cooling mechanisms are investigated through heat budget analysis. The chlorophyll-induced SST variation is dependent on the variation in chlorophyll concentration and net surface heat flux and on such dynamic ocean processes as mixing, upwelling and advection. The mixed layer depth is also an important factor determining the effect. The chlorophyll-induced SST warming appears in most regions during the local spring to autumn when the mixed layer is shallow, e.g., low latitudes without upwelling and the mid-latitudes. Chlorophyll-induced SST cooling appears in regions experiencing strong upwelling, e.g., the western Arabian Sea, west coast of North Africa, South Africa and South America, the eastern tropical Pacific Ocean and the Atlantic Ocean, and strong mixing (with deep mixed layer depth), e.g., the mid-latitudes in winter.