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Calculation of theoretically potential gas amount using stable carbon isotope ratio

Chinese Science Bulletin 1995年第20期40卷 1729-1733页

作者：陈红汉孙永传张启明张国华 China University of Geoscienoes Wuhan 430074 China Nanhai West Oil Corporation Zhanjiang 524057 China

With the development of petroleum exploration, it is more important to know theoretically potential gas amount which can be used as the quantitative evaluation of natural gas source. Hydrocarbon gases are the products of organic matter during its mature history. δ13C of each gas carries a record of its source and maturation information. Previous empirical approach and partition function method not only lack understanding of the stable carbon isotopic controls, but also requires assumption of isotopic equilibrium Recently, Chris Clayton considered the isotopic effects as a Rayleigh

关键词： stable carbon isotope ratio Rayleigh fractionation theoretically potential gas amount.

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The atomic structure and the properties of Ununbium (Z=112) and Mercury (Z=80)

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Science China(Physics,Mechanics & Astronomy) 2007年第6期50卷 707-715页

作者： S.FRITZSCHE B.FRICKE Institut fr Physik Universita..t Kassel 34132Germany

A super heavy element Uub (z = 112) has been studied theoretically in conjunction with rela-tivistic effects and the effects of electron *** atomic structure and the oscillator strengths of low-lying levels have been calculated,and the ground states have also been determined for the singly and doubly charged ions. The influence of relativity and correlation effects to the atomic properties of such a super heavy element has been investigated in detail. The results have been compared with the properties of an element Hg. Two energy levels at wave numbers 64470 and 94392 are suggested to be of good candidates for experimental observations.

关键词： super heavy element, atomic structure, relativistic effects, electron correlation effects, MCDF method A super heavy element Uub (Z = 112) has been studied theoretically in conjunction with rela-tivistic effects and the effects of electron correlations. The atomic structure and the oscillator strengths of low-lying levels have been calculated, and the ground states have also been determined for the singly and doubly charged ions. The influence of relativity and correlation effects to the atomic properties of such a super heavy element has been investigated in detail. The results have been compared with the properties of an element Hg. Two energy levels at wave numbers 64470 and 94392 are suggested to be of good candidates for experimental observations.……

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Structural parameterization and functional prediction of antigenic polypeptome sequences with biological activity through quantitative sequence-activity models (QSAM) by molecular electronegativity edge-distance vector (VMED)

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Science China(Life Sciences) 2007年第5期50卷 706-716页

Only from the primary structures of peptides, a new set of descriptors called the molecular electro-negativity edge-distance vector (VMED) was proposed and applied to describing and characterizing the molecular structures of oligopeptides and polypeptides, based on the electronegativity of each atom or electronic charge index (ECI) of atomic clusters and the bonding distance between atom-pairs. Here, the molecular structures of antigenic polypeptides were well expressed in order to propose the auto-mated technique for the computerized identification of helper T lymphocyte (Th) epitopes. Furthermore, a modified MED vector was proposed from the primary structures of polypeptides, based on the ECI and the relative bonding distance of the fundamental skeleton groups. The side-chains of each amino acid were here treated as a pseudo-atom. The developed VMED was easy to calculate and able to work. Some quantitative model was established for 28 immunogenic or antigenic polypeptides (AGPP) with 14 (1― 14) Ad and 14 other restricted activities assigned as "1"(+) and "0"(-), respectively. The latter comprised 6 Ab(15-20), 3 Ak(21-23), 2 Ek(24-26), 2 H-2k(27 and 28) restricted sequences. Good results were obtained with 90% correct classification (only 2 wrong ones for 20 training samples) and 100% correct prediction(none wrong for 8 testing samples); while con-trastively 100% correct classification (none wrong for 20 training samples) and 88% correct classification (1 wrong for 8 testing samples). Both stochastic samplings and cross valida-tions were performed to demonstrate good performance. The described method may also be suitable for estimation and prediction of classes I and II for major histocompatibility an-tigen (MHC) epitope of human. It will be useful in immune identification and recognition of pro-teins and genes and in the design and devel-opment of subunit vaccines. Several quantitative structure activity relationship (QSAR) models were developed for various oligop

关键词： molecular electronegativity distance-edge vector (VMED), antigenic polypeptide (AGPP) sequences, bioactive oligopeptide (BAOP) chains, quantitative sequence-activity models (QSAM), theoretically computational descriptors (TCD)

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