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WANG Yue BI Xiao-Jun CUI Shu-Wang DING Lin-Kai DAN Zeng-Luo-Bu DING Xiao-Hong FAN Chao FENG Cun-Feng FENG Zhao-Yang FENG Zhen-Yong GAO Xiao-Yu GENG Qing-Xi GUO Hong-Wei HE Hui-Hai HE Mao HU Hai-Bing HU Hong-Bo HUANG Qing JIA Huan-Yu LA Ba-Ci-Ren LE Gui-Ming LI Ai-Feng LI Jin-Yu LOU Yu-Qing LU Hong LU Sui-Ling MENG Xian-Ru MU Jun REN Jing-Ru TAN You-Heng WANG Bo WANG Hui WANG Yong-Gang WU Han-Rong XUE Liang YANG Xian-Chu YE Zong-Hai YU Guang-Ce YUAN Ai-Fang ZHANG Hui-Min ZHANG Ji-Long ZHANG Nai-Jian ZHANG Xue-Yao ZHANG Yong ZHANG Yi ZHA Xi-Sang-Zhu ZHOU Xun-Xiu YUAN Qiang 《中国物理C(英文版)》2008,32(11)
Using the data taken from Tibet Ⅱ High Density (HD) Array (1997 February--1999 September) and Tibet-Ⅲ array (1999 November--2005 November), our previous northern sky survey for TeV γ-ray point sources has now been updated by a factor of 2.8 improved statistics. From 0.0° to 60.0° in declination (Dec) range, no new TeV γ-ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV T-ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level (C.L.), the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits. 相似文献
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Abstract This paper is devoted to investigate extinction and nonextinction conditions of the extended Beverton–Holt equation (BHE) for dynamics of populations in Ecology when potential discontinuities at sampling points are included in the model. The proposed model is described by means of four sequences of parameters. Two of them are the intrinsic growth rate and the carrying capacity sequences which are included in the basic BHE model. The other two ones, namely, the harvesting (i.e., the hunting or fishing quota) and the internal consumption (which can include positive and negative migrations in the considered population habitat) sequences are included to parameterize the model discontinuities. Such discontinuities are related to impulses in the corresponding continuous‐time logistic equation. The obtained results establish how the harvesting quota and/or the internal consumption has to be fixed to guarantee the population nonextinction or, eventually, its extinction. Finally, some controllability results related to the search of a carrying capacity sequence such that the solution of the proposed impulsive BHE tracks a reference one are obtained. 相似文献
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A. T. Rudchik K. W. Kemper V. O. Romanyshyn O. A. Ponkratenko V. M. Kyryanchuk V. V. Uleshchenko 《The European Physical Journal A - Hadrons and Nuclei》2009,41(1):31-37
The data for the 7Li + 9Be and 7Be + 9Be elastic scattering at the energies E
lab(7Li) = 15.75 , 24, 30, 34, 63 and 130MeV and E
lab(7Be) = 17 , 19 and 21MeV were analyzed within the optical model and coupled-reaction-channels method. The elastic and inelastic
scattering, reorientation of 7Li , 7Be and 9Be as well as most important transfer reactions were included in the coupled-channels scheme. The resulting 7Li and 7Be potentials are very similar and have the same energy dependence. The real potential for recently derived 8Be + 9Be scattering potentials is very similar to that for 7Li , 7Be but the imaginary part of the 8Be one has a much greater strength at longer range. 相似文献
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Romanyshyn L Tiller PR Alvaro R Pereira A Hop CE 《Rapid communications in mass spectrometry : RCM》2001,15(5):313-319
Liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods developed for quantification using rapid ('ballistic') gradients on narrow bore, short HPLC columns have been previously described by this laboratory. This paper compares the fast gradient approach with the more traditional high-organic isocratic LC/MS/MS methods. The comparison is based on an analysis of the effectiveness of the chromatographic separations when using the two approaches (i.e. k', N, and W). The data presented herein are derived from actual biological samples analyzed as part of the drug discovery process. 相似文献
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Ultra-fast chromatographic separations has enabled fast chromatographic method development and rapid analysis for sample quantification. Decreasing over-all analytical time has become a factor of major importance for all aspects of drug discovery. However, merely decreasing chromatographic analysis time by decreasing k' can lead to inconsistent quantitative or qualitative results due to ineffective separations in complex matrices. We have found that by changing column length and gradient slope we can maintain chromatographic integrity of chemically diverse analytes and achieve the analytical speed required for bioanalytical drug discovery quantitative analysis. We have optimized method development strategy by performing separations on 2x20 mm HPLC columns at flow-rates of 1.5 ml/min to 2 ml/min with full linear gradients achieved in 1 min for the quantification of pharmaceuticals and their metabolites from biological matrices. This method development strategy can be readily adapted to other matrices. This paper will discuss the effects of column length and gradient time in ultra-fast chromatographic resolution. 相似文献
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Liquid chromatography-mass spectrometry (LC/MS) has become one of the most widely used analytical techniques in both qualitative and quantitative analysis of small molecules. Recently, with the increasing demand for ever-higher sample throughput, the use of faster chromatographic separations has become popular, along with other LC/MS methods that decrease analytical cycle-time. The burgeoning use of LC/MS has meant that the primary expertise of many practitioners today is not in the field of LC/MS, which has been facilitated by the ease-of-use of modern LC/MS systems. An examination of the current state of the literature, relating to "fast LC/MS", should serve well to those new to LC/MS, and should help them in the development of fast LC/MS methods that are effective in terms of both the chromatography and the utilization of the mass spectrometer. This review paper focuses on fast LC/MS analyses of small molecules that have been reported in peer-reviewed publications. 相似文献
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