排序方式: 共有50条查询结果,搜索用时 15 毫秒
1.
下泥盆Siegenian 组砂岩储层是阿尔及利亚D 区块的主要勘探目的层。研究其储层特征及控制因素对勘探潜力的评价及后期开发有着重要的指导意义。经过研究,块内砂岩类型主要为石英砂岩,岩屑石英砂岩,储层储集空间主要为各种类型的次生孔隙和少量的裂缝,原生粒间孔不发育,多为粒间溶孔、粒内溶孔及微裂隙。孔隙结构主要为中小孔微细喉,储层物性较差,为中低孔、特低渗储层类储层;储层性质主要受到沉积条件和成岩作用的控制,成岩作用中以压实作用和溶蚀作用对储层物性影响最大,其次是胶结作用和交代作用。 相似文献
2.
Evaluation of Inhaled Versus Deposited Dose Using the Exponential Dose‐Response Model for Inhalational Anthrax in Nonhuman Primate,Rabbit, and Guinea Pig
下载免费PDF全文
![点击此处可从《Risk analysis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bradford W. Gutting Andrey Rukhin Ryan S. Mackie David Marchette Brandolyn Thran 《Risk analysis》2015,35(5):811-827
The application of the exponential model is extended by the inclusion of new nonhuman primate (NHP), rabbit, and guinea pig dose‐lethality data for inhalation anthrax. Because deposition is a critical step in the initiation of inhalation anthrax, inhaled doses may not provide the most accurate cross‐species comparison. For this reason, species‐specific deposition factors were derived to translate inhaled dose to deposited dose. Four NHP, three rabbit, and two guinea pig data sets were utilized. Results from species‐specific pooling analysis suggested all four NHP data sets could be pooled into a single NHP data set, which was also true for the rabbit and guinea pig data sets. The three species‐specific pooled data sets could not be combined into a single generic mammalian data set. For inhaled dose, NHPs were the most sensitive (relative lowest LD50) species and rabbits the least. Improved inhaled LD50s proposed for use in risk assessment are 50,600, 102,600, and 70,800 inhaled spores for NHP, rabbit, and guinea pig, respectively. Lung deposition factors were estimated for each species using published deposition data from Bacillus spore exposures, particle deposition studies, and computer modeling. Deposition was estimated at 22%, 9%, and 30% of the inhaled dose for NHP, rabbit, and guinea pig, respectively. When the inhaled dose was adjusted to reflect deposited dose, the rabbit animal model appears the most sensitive with the guinea pig the least sensitive species. 相似文献
3.
张晓平 《汕头大学学报(人文社会科学版)》2001,17(2):28-32,36
文学意象的创造不是孤立的,它深受文化传统的影响和制约。本文以“太阳”意象为例,分析了文学意象的蕴涵既有历史的积淀又有在创新过程中的转变,并从接受美学角度指出,读者的文化修养是影响文学意象理解的重要因素。 相似文献
4.
介绍了一种测量微波晶体管噪声参数的方法,并用矢量网络分析仪和噪声系数测试仪组建了一套自动测试系统。在系统软件的控制下,该系统可对微波晶体管噪声参数进行快速、准确的测量;并给出了部分测试结果,还与厂家典型值进行了比较。 相似文献
5.
本文介绍了两种光学镀膜真空淀积技术——离子辅助淀积和反应离子镀,并详述了近年来的应用及进一步的发展。 相似文献
6.
Paul D. Moskowitz William H. Medeiros Neal L. Oden Henry C. Thode Jr. Elizabeth A. Coveney Robert E. Rosenthal 《Risk analysis》1987,7(3):371-388
Experimental data were compiled for seven soybean varieties studied at four different locations in the U.S. for a period of one to three years. Three dose–response functions (linear, quadratic, and Weibull) were fitted, as appropriate, to the experimental data. Effects of acid deposition on soybean yields were estimated by combining variety-specific dose–response and production data. These calculations suggest that U.S. soybean production (2.2 billion bushels in 1982) would increase by 3.2 million bushels with a 10% reduction in 1982 hydrogen ion concentration levels in all counties where soybeans were grown, and by almost 70 million bushels with uniform improvement to pH 5.2. These estimates are based on many simplifying assumptions and are subject to several important sources of uncertainty explored in this study. The calculated changes are small in comparison with effects from other natural and anthropogenic stresses. 相似文献
7.
元素硫沉积是高含硫气藏开采过程中存在而又必须解决的难题之一。随着高含硫气藏储层压力不断下降,元素硫溶解度也不断下降,一旦元素硫溶解度低于元素硫含量,元素硫就会从地层中沉积下来。沉积的元素硫会堵塞地层孔隙,降低渗透率,严重影响气井产能。为了研究元素硫在地层中的沉积形态和沉积特征,利用自主设计的实验流程和实验方法,使TD5-1井高含硫气体通过岩芯,并降低压力让元素硫在岩芯中沉积下来,然后对沉积了元素硫的岩芯进行电镜扫描和能谱分析,首次得到了元素硫在岩芯中的沉积形态,即元素硫主要以膜状形式分布在岩芯孔隙壁面上。该研究结果为深入认识、掌握元素硫沉积规律以及指导高含硫气藏合理开发奠定了基础。 相似文献
8.
9.
Gary W. Oehlert 《Revue canadienne de statistique》1988,16(1):51-60
We investigate ordinary least-squares and Bayesian methods for constructing interval estimates for historical lake pH's inferred from diatom sediments. The Bayesian method explicitly models several forms of variability, including the sampling and classification variability of the diatom records, estimation variability, and measurement error in observed pH's. The two methods produce similar interval estimates, but the Bayesian model allows design recommendations to be made. 相似文献
10.
以往对高含硫气藏开发技术研究所需录取的资料在实际操作过程中难以得到。因此,针对井筒附近发生硫沉积的高含硫气藏,建立了硫沉积复合气藏产量递减数学模型,运用 Stefest 数值反演绘制了 Blasingame 产量递减曲线,并分析了硫沉积对气井产量递减规律的影响。结果表明:产量递减中期,硫沉积区含硫饱和度越高,无因次递减产量积分“导数”曲线下凹越深,当含硫饱和度增大到 0.5 时,积分“导数”曲线下凹至最深,积分“导数”达最小值;硫沉积半径越小,无因次递减产量平缓段出现的时间越早;产量递减后期,无因次递减产量积分与积分“导数”曲线晚期为一条斜率为–1 的直线,表现为调和递减。该方法比压力恢复试井法更具优越性,可为高含硫气藏的开发提供指导。 相似文献