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A novel formula for location of double bond in alkenyl acetates and alcohols based on mass spectral data of dimethyl disulfide derivatives

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Chinese Journal of Chemistry 1997年第6期15卷 534-540页

作者： Xiao, jh Yuan, G Yang, LZ Sun, YF Wang, XL Peking Univ Dept Chem Beijing 100871 Peoples R China

A new formula was presented for locating double bond position in dodecenols, tetradcenols hexadecenols and their acetates, based on mass spectral data of dimethyl disulfide derivatives. In this procedure, molecular ion and base peak ion were utilized as characteristic parameters to identify the positional isomers. The method was tested with mass spectra of 25 dimethyl disulfide derivatives of mono-unsaturated acetates and alcohols, and the original double-bond position in each isomer was located unambiguously.

关键词： mass spectrometry double bond positional isomer sex pheromone

Ab initio Studies on the Reaction of M￣++CH_4→M￣+CH_2+H_2(M=Sc,Y,La)

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Chemical Research in Chinese Universities 1996年第4期12卷 368-373页

作者： Zhu, RS Dai, SS Huang, jh Ye, S YUNNAN UNIV DEPT CHEMKUNMING 650091PEOPLES R CHINA

The present paper covers the reactions of M￣+ +CH_4→M￣+CH_2+H_2(M=Sc,Y,La)investigated theoretically using ab initio MO methods and reaction channels onthe singlet potential energy surfaces (PESs) examined and discusses the reactionmechanism. The results indicate that the formation of M￣+CH_2 is primarily via a sin-glet H M￣+ CH_3 intermediate,followed by a four-center elimination of H_2,all ofthese reactions have negative activation energies and the trend of reactivity is La￣+>Sc￣+>Y￣+.

关键词： s:Ab initio calculation Transition metalion Methane Reaction mechaNism

A Novel Condensation Reaction of Alkyl Aryl Ketone with Ethyl Ortho-Formate under Microwave Irradiation

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Chinese Chemical Letters 1998年第1期9卷 1-4页

作者： Yu, jh Hu, YL Yang, SY Yin, YQ Cai, LP Chinese Acad Sci Lanzhou Inst Chem Phys State Key Lab Oxo Synthesis & Select Oxidat Lanzhou 730000 Peoples R China Lanzhou Univ Natl Lab Appl Organ Chem Lanzhou 730000 Peoples R China

Under microwave irradiation, boron trifluoride has been found to mediate a novel condensation reaction of alkyl aryl ketone with ethyl ortho-formate to give a series of new condensation products (5,6,7,8). Their structures were determined by IR, H-1/C-13-NMR, MS spectra, and the crystal structure of 8 was further defined by X-ray diffraction.

关键词： microwave irradiation condensation alkyl aryl ketone

A new method of NMR technique in the study of active center structure of metalloenzyme

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Chinese Science Bulletin 1997年第20期42卷 1703-1705页

作者： Hu, jh Xu, YT Zheng, XF cheng, GB Chinese Acad Sci Dalian Inst Chem Phys Dalian 116023 Peoples R China

UP until now, all methods using NMR technique to study the coordinated structure of activecenter in metalloenzyme are to reconstitute the diamagnetic ions [i. e. Zn(Ⅱ), etc.] in metal-loenzyme or its paramagnetic ions [i. e. Cu(Ⅱ), etc] whose electronic relaxation times are notshort enough to substitute the metal ions of active center in enzyme with [Co(Ⅱ), Ni(Ⅱ)],which are paramagnetic and whose electronic relaxation time is shorter, so that the ~1H NMRspectra of the coordinated structure of active center are separated from those of the rest of en-

关键词： metalloenzyme copper-zinc superoxide dismutase cobaltous chlorate NMR.

Study of primary leiomyosarcoma induced by MNNG in BALB/C nude mice

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World Journal of Gastroenterology 2000年第1期6卷 128-130页

作者： Zhu JS Su Q Zhou JG Hu PL Xu jh Institute of Oncology Hengyang Medical CollegeHengyang 421001China

INTRODUCTIONIt has been well known that MNNG is one of thestrong and multipotential carcinogens that havebeen frequently reported inducing malignant *** have successfully induced rat and doggastric adenocarcinomas,squ... 详细信息

关键词： Subject headings leiomyosarcoma stomach neoplasms MNNG BALB/C nude mice

Recognition and implication of eclogite in the western Altun Mountains, Xinjiang

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Chinese Science Bulletin 1997年第11期42卷 931-934页

作者： Liu, L Che, ZC Luo, jh Wang, Y Gao, ZJ Department of Geolcgy Northwest University Xi’an China

SINCE high-pressure metapelitic rocks have been discovered in the Beiketan area of eastern Al-tun Mountains,a set of eclogite has been recognized in south of Jianggesayi,western *** eclogite,associated with quartz-garnet-clinopyroxenite and metamorphosed retrogradelyto garnet-amphibolite partially,is exposed in the Proterozoic meso- to hypometamorphic rocksand can be traced eastward to northwest of Mangya asbestos deposit,for about 200

关键词： Altun Mountains eclogite high-pressure metamorphism.

Thymidine kinase gene mutation leads to reduced virulence of pseudorabies virus

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Chinese Science Bulletin 2001年第23期46卷 1972-1975页

作者： Pan, ZS Zhang, CY Ding, jh Min, P Wuhan Univ Coll Life Sci Inst Virol Wuhan 430072 Peoples R China

To explore correlation between the tk gene structure of pseudorabies virus (PRV) and its virulence, to study the effect of the gene mutation on PRV biological properties, and to investigate mechinism of reduced virulence, thymidine kinase (TK)-deficient mutant of pseudorabies virus strain Hubei (PRV HB) was isolated by selection for resistance to 5-bromodeoxyuridine. The tk genes of PRV HB and its TK mutant were cloned and sequenced. 1587 base pairs of the tk gene and flanking regions of wild-type (wt) virus were sequenced, which included an open reading frame (ORF) of 1098 bp encoding a protein of 366 amino acids. The ORF contained two 137-bp repeated sequences, which were connected by an adenosine. 1458 bp of the tk and flanking regions of TK- mutant were sequenced. Analysis of the tk gene sequence of TK mutant indicated that one of 137 bp repeated sequence and the connecting adenosine in the tk gene of the wt virus was deleted and a repeated sequence of 8 nucleotides (GCGCGCC) was inserted. All

关键词： pseudorabies virus thymidine kinase nucleotide se- quence amino acid sequence TK mutant.

p53-dependent and independent apoptosis induced by ionizing radiation in murine bone marrow cells

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Chinese Science Bulletin 1997年第2期42卷 155-159页

作者： Cui, YF Zhou, PK Lord, BI Hendry, jh BEIJING INST RADIAT MED BEIJING 100850PEOPLES R CHINA

APOPTOSIS or programmed cell death is a model of cell death, along with typical morphological and biochemical changes. The cell death, occurring during embryonic development, T and B cell maturation and endocrine-induced atrophy, is a physiological apoptosis which controls the amount of cells in the body. Apoptosis can also be induced by various factors, such as ionizing radiation and anti-tumour agents which damage DNA, and has been proposed to be a consequence of the induced expression of some tumour-related genes or increase of the proteins sta-

关键词： apoptosis p53 knock-out mouse bone marrow cells ionizing radiation.

The compression of IR spectra by using wavelet neural network

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Chinese Science Bulletin 1997年第10期42卷 822-825页

作者： Liu, W Li, JP Xiong, jh Pan, ZX Zhang, MS Department of Applied Chemistry University of Science and Technology of China Hefei China Fundamental Physics Center University of Science and Technology of China Hefei China

IR spectra play an important role in determining the structure of compounds qualitatively *** general a great number of data are required to exactly show the features ofthe *** various compounds,there are massive IR *** the basicfeatures of IR spectra being reserved,it is important to compress IR spectra for improving thestorage,index and process of IR *** wavelet neural network(WNN)is a newneural network model based on wavelet ***,its introduction and applica-tion in chemistry have not been *** this note,WNN is applied to the compression ofthe IR spectra of *** results show that the original spectra can be

关键词： wavelet neural network IR spectra data compression.