斑节对虾白斑综合症杆状病毒感染的实验模式     

邱德全  林继辉  刘丽  张凌飞 《广东海洋大学学报》2001,21(1):10-13

在建立斑节对虾实验室养殖模式的基础上，对野外采集的有白斑综合症病毒（WSSV）病典型症状的斑节对虾初步纯化其病毒，并进行WSSV的PCR检测，得到WSSV的感染用样品。对健康斑节对虾分别进行浸浴感染，投喂感染和注射感染。对感染死亡个体进行WSSA的PCR检测和细菌检测，证实WSSV感染性和致死性。浸浴感染、投喂感染和注射感染的感染量分别为4mL/L、0.2g/10g虾体、1/2稀释液0.05mL/10g虾体，死亡开始时间分别为16d、42h、28h，三种感染模式最终死亡率100%，从开始死亡到全部死亡延续时间分别为15d、82h、44h。  相似文献   

Evaluation of Fluorobenzoate Tracers in Surface Soils   总被引：2，自引：0，他引：2  

Dan B. Jaynes 《Ground water》1994,32(4):532-538

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On the calculation of perturbations in the radial position of satellites     

Lin Liu 《Chinese Astronomy and Astrophysics》1997,21(4):488-500

With the aim of analyzing the errors in the radial position of satellites, we give in this paper the expressions for the radial perturbation which include the complete zeroth- and first-order terms in the orbital eccentricity. A simpler and faster method of calculating the perturbation is given.  相似文献   

The international politics of whaling: Peter J Stoett UBC Press, 1997, 228 pp. $65.00. ISBN 0-7748-0605-2     

Dan Goodman 《Marine Policy》1997,21(6):547-549

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山西省石炭系与二叠系界线     

林联情 《河南国土资源》1995,(1)

１８８２年李希霍芬在太原西山建立石炭系的太原系含煤建造以来，石炭系与二叠系的分界意见，归纳起来有三：①以Ｐｓｅｕｄｏｓｃｈｗａｇｅｒｉｎａ（ｓ．１）带之底为界，下面为石炭系，上面为二叠系；②以晋东南的灰白色“佳祥砂岩”与太原西山黄绿色“骆驼脖子砂岩”对比，砂岩底面为石炭系与二叠系的分界线，下面是石炭系山西组，上面是二叠系石盒子组，山西组的地层时代定为晚石炭世；③以晋东南灰白色第三砂岩（陵川砂岩）与太原西山“北岔沟砂岩”对比，砂岩底面为石炭系与二叠系的分界线，下面是石炭系太原组，上面是二叠系山西组，山西组的地层时代为早二叠世。笔者认为石炭系与二叠系的划分，以第③方案较适宜。  相似文献   

Numerical calculations in the orbital determination of an artificial satellite for a long arc     

Lin Liu  Xinhao Liao 《Celestial Mechanics and Dynamical Astronomy》1994,59(3):221-235

Numerical methods are usually used for the computation of ephemerides with perturbations for the precise orbital determination of an artificial satellite. But their numerical stability will be encountered in a long arc. In this case the use the improved Encke special perturbation methods has been suggested. The results of this paper show that Encke's method does indeed have a certain effectiveness, but cannot yet completely resolve the numerical stability, and the more efficient method is to use the energy integral or its variational relation to control the growth of the along-track error in general numerical calculations so that the aim of stabilization can be achieved.  相似文献   

广东省拖网网囊调查     

杨吝  张旭丰  孙典荣  谭永光 《广东海洋大学学报》2001,21(4):22-26

为实施中华人民共和国国家标准《南海区拖网网囊最小网目尺寸》,对广东省范围内拖网网囊现状进行摸底调查,结果表明,广东省沿海拖网渔船现用网囊网目尺寸(内径)在16.7～35.2 mm范围内,总体平均为27 mm,均未能达到1989年国家技术监督局发布的中华人民共和国国家标准--《南海区拖网网囊最小网目尺寸》--内径39 mm.  相似文献   

Effective collision strengths with inclusion of resonance for hyperfine-structure transitions in H- and Li-like ions     

Hong Lin Zhang  Douglas H. Sampson 《Monthly notices of the Royal Astronomical Society》2001,322(3):433-437

Calculations are made of the resonance contribution to electron-impact excitation of H-like ¹³C and Li-like ²³Na, ²⁵Mg, ²⁷Al and ²⁹Si to the upper hyperfine levels that produce millimetre (mm) lines of likely astrophysical interest. The resonance contribution is found to be very important for these Li-like ions, considerably more important than for Li-like ⁵⁷Fe considered previously. However, resonances are found to be rather unimportant for H-like ¹³C. The effect of radiative decay on the resonance contribution is found to be insignificant in all of the present calculations.  相似文献   

海量多波段星表数据的交叉证认的实现   总被引：2，自引：1，他引：1  

高丹  张彦霞  赵永恒 《天文研究与技术》2005,2(3):186-193

许多天文学家需要星表来选源、证认和研究。目前国外有一些大的数据中心提供了星表查询、多源查询(即小样本交叉证认)、可视化等功能。但是随着大数据量及全波段天文时代的到来,这些服务已经越来越不能满足天文学家的需求。在详细分析了国外数据中心的服务后,提出了新的问题,并给出一套解决方案。着重讨论了任意两个星表的交叉证认和大数据量星表的交叉证认的实现,以及交叉证认结果的分类和参数的自由选择等方面的课题。  相似文献   

A concordance model of the Lyman α forest at z= 1.95     

Tridivesh Jena  Michael L. Norman  David Tytler  David Kirkman  Nao Suzuki  Angela Chapman  Carl Melis  Pascal Paschos  Brian O'Shea  Geoffrey So  Dan Lubin  Wen-Ching Lin  Dieter Reimers  Eckardt Janknecht  Cora Fechner 《Monthly notices of the Royal Astronomical Society》2005,361(1):70-96

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