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虾蟹混养塘中WSSV对三疣梭子蟹(Portunus trituberculatus)致死效应的定量研究 总被引:1,自引:0,他引:1
采用实时荧光定量PCR法,在对白斑综合症多发的虾蟹混养塘内三疣梭子蟹体内病毒含量进行定量跟踪检测的基础上,结合电子显微镜及病理切片,对室内经口服、注射两种回感模式处理已感染白斑综合症病毒的濒死三疣梭子蟹体内病毒含量进行实验验证,并观察其体内主要器官组织的病理改变。结果表明,受白斑综合症病毒感染的三疣梭子蟹存活与死亡取决于蟹体内病毒含量,当病毒含量≥109拷贝/ml时均进入濒死或死亡阶段,其主要器官组织均有明显的病理改变。 相似文献
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PAULJ.GEMPERLINE 《地理学报(英文版)》1989,(3)
One of the major application areas of factor analysis, multivariate calibration and quantitation, is coveredin this review. The algorithms, methodologies and applications covered include principal componentregression, target transformation factor analysis, singular value decomposition and rank annihilationfactor analysis. Many important areas of research having relevance to multivariate calibration andquantitation problems are also covered in this review, including background correction, measurementerror, rank determination, cross-validation, figures of merit, detection of invalid samples, experimentaldesign, sample selection, statistical inference and wavelength selection. 相似文献
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光学显微镜矿物定量方法简单、结果可靠,被广泛应用于工艺矿物学和岩矿鉴定工作中。"线测法"测试速度快,效率高,并且适用于细粒矿物颗粒,在应用中占有重要的地位。但是常规的测试线具有方向同一性的特征,不能很好地处理待测矿物颗粒"择优取向"的问题。针对该问题,本文阐述了一种通过旋转载物台进行镜下矿物定量的方法。主要工作原理为:系列圆周线穿切各待测矿物颗粒截线长度比等于其体积比。主要测试过程为:转动载物台一周,测定待测矿物颗粒与视域周边相交的各段圆周截线所占的包含角之和(’K)。观测一定数量的视域(N),计算质量百分含量(W)=[(’K/(N×360)]·(δ/Δ)×100%。经理论分析,并对方铅矿、闪锌矿和磁铁矿光片进行了检验,结果表明:旋转载物台矿物定量工作量低、简单易行、精度较高,与传统"线测法"测试结果差值小于±5%,并且可以有效地解决待测矿物颗粒"择优取向"对测试结果的不利影响。 相似文献
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The rapid development of biomarker geochemistry and its application to petroleum exploration problems has been due in no small part to gas chromatography-mass spectrometry (GC-MS). The recent availability of hybrid and triple stage quadrupole mass spectrometers have introduced a number of novel ways for the detection and identification of biomarkers present in extremely complex mixtures of organic compounds from various sources including crude oils and source rock extracts.A triple stage quadrupole mass spectrometer has been used in the MS/MS mode with both a gas chromatograph and direct insertion probe as inlet systems, to develop alternative methods for biomarker analyses. Selected ions formed in the ion source of the mass spectrometer are permitted to enter the collision cell where, following collision with an inert gas, the daughter ions are separated using the third quadrupole. In this manner specific parent/daughter ion relationships are utilized to monitor and resolve classes of biomarkers or individual components from within a complex mixture. Furthermore, deuterated analogues of naturally occurring biomarkers can be utilized for quantitation purposes since the parent/daughter relationship for the standard will differ, depending on the number of deuterium atoms present, even though the relative retention times are identical.The ability of MS/MS to resolve components spectrometrically as well as chromatographically greatly enhances the analytical short-column capabilities of this system. In this paper the utilization of GC-MS/MS and the direct insertion probe MS/MS to determine biomarker distributions in crude oils both qualitatively and quantitatively are discussed. The results from the study show that it is possible to use the probe data to rapidly correlate oils on the basis of their source materials and if necessary select samples for more detailed analysis by GC-MS/MS. A major advantage of the direct insertion probe method is speed of analysis although some component resolution is lost. In an effort to minimize this problem and still maintain the rapid analysis time, the use of short columns in the GC is also described. This approach provides the ability to undertake relatively rapid analyses with limited chromatographic resolution but at relatively high levels of sensitivity. 相似文献
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