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Extraction and Crystal Structure of Physalin B 被引量:1
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作者 杨海军 沙聪威 +1 位作者 陈梅果 胡玲 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第5期795-800,共6页
The title compound of physalin B(C28H32O9), a main active physalin of Physalis angulata L, was isolated from the whole plant of Physalis angulata L, and characterized by X-ray diffraction analysis. It crystallizes i... The title compound of physalin B(C28H32O9), a main active physalin of Physalis angulata L, was isolated from the whole plant of Physalis angulata L, and characterized by X-ray diffraction analysis. It crystallizes in the monoclinic system, space group P21 with C28H32O9, a = 12.4996(2), b = 14.35620(10), c = 14.75190(10), V = 2607.97(5) 3, Z = 4, Dc = 1.382 mg/cm3, Mr = 542.56, F(000) = 1152, and μ = 0.870 mm-1. The final R = 0.0389 and wR = 0.1037 for 47670 observed reflections(I 〉 2σ(I)). The rigid molecule consists of eight fused rings involving two lactones. There are two C28H32O9 molecules in an symmetric unit, and the title compound is stacked into a 3D layer structure through hydrogen bonds. In the 5~20 μmol/L range, physalin B can significantly inhibit the secretion of inflammatory cytokines TNF-α and IL-6 on RAW264.7 cells. The results suggest that physalin B has anti-inflammatory activity in vitro. 展开更多
关键词 physalin b crystal structure Physalis angulata L physalin
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Synthesis and Electronic Structure of A2B Type Halogen Atoms Substituted H3-Triarylcorroles 被引量:1
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作者 李敏智 朱卫华 +3 位作者 MACK John MKHIZE Scebi NYOKONG Tebello 梁旭 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第3期367-380,共14页
Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism(MCD) spectra and a series of TD-DF... Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism(MCD) spectra and a series of TD-DFT calculations have been used to analyze trends in the electronic structures. Significant differences are observed in the optical spectra when solvents of differing polarity are used,which can be assigned to the effect of NH-tautomerism. 展开更多
关键词 A_2b type corrole solvatochromism electronic structure spectroscopy TD-DFT
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ELECTRIC PROPERTY AND STRUCTURE OF EOSIN B,ROSE BENGAL,EOSIN 10B (PHLOXINE B) AND THEIR RARE EARTH COMPLEXES
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作者 王流芳 陈忠林 +2 位作者 彭周人 卢爱茹 张联祥 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第2期149-150,共2页
The electric property and structure of some fluorescein derivatives and their rare earthcomplexes have been reported before.In order to investigate the effect of differentsubstituents on the electric property,the chan... The electric property and structure of some fluorescein derivatives and their rare earthcomplexes have been reported before.In order to investigate the effect of differentsubstituents on the electric property,the change of resistivity with temperature of eosin B(disodium salt of dibromodinitrofluorescein),rose bengal (disodium salt of tetrachlorotetraiodofluorescein),eosin 10B (dipotassium salt of dichlorotetrabromofluorescein) andtheir complexes with La(Ⅲ),Ce(Ⅲ),Gd(Ⅲ) and Y(Ⅲ) is studied in this paper. 展开更多
关键词 AND THEIR RARE EARTH COMPLEXES ELECTRIC PROPERTY AND structure OF EOSIN b ROSE bENGAL EOSIN 10b PHLOXINE b REC
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Structures of Isodoternifolin A and B
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作者 Wang, ZM Feng, H Liang, XT 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第9期816-817,共2页
StructuresofIsodoternifolinAandBStructuresofIsodoternifolinAandB¥ZhiMinWANG;HaoFENGandXiaoTianLIANG(Institut... StructuresofIsodoternifolinAandBStructuresofIsodoternifolinAandB¥ZhiMinWANG;HaoFENGandXiaoTianLIANG(InstituteofChineseMateria... 展开更多
关键词 structures of Isodoternifolin A and b
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STRUCTURE OF MOLECULAR COMPOUND CRYSTAL A_2B(A =1, 6, 7, 8,-TETRA-PHENYL (3, 4-BENZO)BICYCLO[4, 2, 0]OCTA-7-ENE, B=CIS, CIS-1,2,3,4,-TETRAPHENYLBUTADIENE)
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作者 环振威 刘卫国 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1993年第5期383-386,共4页
C100H78, (A: C36H28, B: C28H22) Mr = 1279. 74, monoclinic, P21/a, a=17. 282(3), b=10. 669(4), c= 19, 927(3) A , β =102. 99(1)°,V = 3580. 1(2) A3, Z=2, μ(MoKα) = 0. 623cm-1, F(000) = 1356, Dc=1. 187g/cm3, room ... C100H78, (A: C36H28, B: C28H22) Mr = 1279. 74, monoclinic, P21/a, a=17. 282(3), b=10. 669(4), c= 19, 927(3) A , β =102. 99(1)°,V = 3580. 1(2) A3, Z=2, μ(MoKα) = 0. 623cm-1, F(000) = 1356, Dc=1. 187g/cm3, room temperature. The final R=0. 084, Rw = 0. 086 for 1255 independent observed reflections (I≥3σ(I)). Owing to the existence of 1,6,7, 8-Tetraphenyl (3,4-benzo)-bicyclo[4, 2, 0]octa-7-ene(A) , cis, cts-1, 2, 3, 4-Tetraphenylbutadiene (B) in A2B can take the different conformation from the one in the pure B crystal. The reason of the formation of this molecular compound crystal is put forward. 展开更多
关键词 Crystal structure Molecular Compound A2b Type
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Ab Initio Theoretical Prediction on Structures of Boron Cationic Cluster B_(17)^+
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作者 Xu-Guang HU Yu-Min CAI Qian-Shu LI(Institute of Theoretical Chemistry, National Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130023)(Department of Chemical Engineering, Xi an Petroleum Institute,Xi an, 710061)(Col 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第8期737-740,共4页
Four isomers of the three-dimensionally connected bare boron cationic cluster B were investigated by using ab initio molecular orbital theory at the HF/6-31G level. The results show that the D5h symmetric isomer of B ... Four isomers of the three-dimensionally connected bare boron cationic cluster B were investigated by using ab initio molecular orbital theory at the HF/6-31G level. The results show that the D5h symmetric isomer of B is a possible isomer candidate of its stable geometries with closed structure. 展开更多
关键词 Ab Initio Theoretical Prediction on structures of boron Cationic Cluster b
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Precipitation behavior of B2-like particles in Fe-Cu binary alloy 被引量:6
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作者 HuipingRen WeiminMao 《Journal of University of Science and Technology Beijing》 CSCD 2002年第3期185-187,共3页
The precipitation behavior in Fe-Cu binary allow was investigated undertransmission electron microscope (TEM) during aging at 650 deg C for the time range of 100 s to 300h. In addition to the zones with higher copper ... The precipitation behavior in Fe-Cu binary allow was investigated undertransmission electron microscope (TEM) during aging at 650 deg C for the time range of 100 s to 300h. In addition to the zones with higher copper content and epsilon-Cu were observed, a metastablephase with B2-like structure was found in the early stage of the precipitation process, which isquite different from the equilibrium copper phase shown in the Fe-Cu binary phase diagram and hasperfect coherent relationship to the alpha-Fe matrix. The appearance of B2-like structure is veryimportant concerning the mechanism of aging strengthening effect and mechanical properties ofcorresponding engineering steels and alloys containing copper. 展开更多
关键词 Fe-Cu alloy PRECIPITATION b2 structure
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Designing and Realization of Database Platform of County Agricultural Production Technology in Yunnan Province 被引量:1
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作者 ZHANG Li-lian LI Wen-feng PENG Lin 《Asian Agricultural Research》 2010年第2期30-32,共3页
According to the objective reality in Yunnan Province,such as great difference of weather,a great proportion of minorities,technological backwardness of agricultural production,low conversion rate of research accompli... According to the objective reality in Yunnan Province,such as great difference of weather,a great proportion of minorities,technological backwardness of agricultural production,low conversion rate of research accomplishments,and a limited number of agricultural technical personnel,ASP.NET technique and SQL Server 2005 database technique are adopted.Database platform of county agricultural production technology in Yunnan Province is established by using B/S structure.This platform includes presentation layer,application layer,and data layer,involving regional information,technology column information,technology classification information,technology content and other databases.It has six functional modules,namely information browse,system management,regional maintenance,technical section maintenance,category maintenance and technical information release,integrating crop cultivation,livestock breeding,economic forest management,plant protection,agricultural products processing,agricultural machinery use and other agricultural technical information.This platform can exchange information dynamically with the client,perform the query request from users,and send the result to users.This database platform has friendly interface,profuse information,high pertinency and so on,which offers rich and reliable information resources to farmers,agricultural technical personnel,and government.At present,this platform has been popularized in some areas of Yunnan Province and has obtained good results. 展开更多
关键词 Agricultural production technology Database platform b/S structure China
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Ultra-high strength Mg-Li alloy with B2 particles and spinodal decomposition zones 被引量:1
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作者 Shun Zhang Ruizhi Wu +3 位作者 Feng Zhong Xiaochun Ma Xiang Wang Qiang Wu 《Fundamental Research》 CAS CSCD 2023年第3期430-433,共4页
The bcc-structured Mg-Li alloy is currently the engineering metallic material with the lowest density,but it has not been widely used due to its low strength.In this paper,alloying Zn effectively improves the strength... The bcc-structured Mg-Li alloy is currently the engineering metallic material with the lowest density,but it has not been widely used due to its low strength.In this paper,alloying Zn effectively improves the strength of the bcc-structured Mg-Li alloy.Due to the semi-coherent B2 structured nanoparticles,the compressive yield strength of the as-cast Mg-13Li-9Zn alloy reaches higher than 300 MPa.Due to the solid solution strengthening of Zn and the spinodal zone,the compressive yield strength of the as-quenched Mg-13Li-15Zn(LZ1315)alloy immediately increases to 400 MPa.In addition,the as-quenched LZ1315 alloy exhibits natural aging strengthening behavior.Due to the precipitation of B2 nanoparticles,the yield strength of the peak aged alloy is up to 495 MPa. 展开更多
关键词 Mg-Li alloy Alloying Zn Semi-coherent b2 structure Solid solution strengthening Natural aging strengthening
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First-principles investigation of B2 partial disordered structure,martensitic transformation, elastic and magnetic properties of all-d-metal Ni-Mn-Ti Heusler alloys
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作者 Ziqi Guan Jing Bai +5 位作者 Jianglong Gu Xinzeng Liang Die Liu Xinjun Jiang Xiang Zhao Liang Zuo 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第9期103-111,共9页
In this work,the B2 partial disordered structure of the austenitic parent phase,martensitic transformation,elastic and magnetic properties of the Ni8 Mn4+xTi4-x(x=0,1 and 2) Heusler alloys have been systematically inv... In this work,the B2 partial disordered structure of the austenitic parent phase,martensitic transformation,elastic and magnetic properties of the Ni8 Mn4+xTi4-x(x=0,1 and 2) Heusler alloys have been systematically investigated by the first-principles calculations.The preferential atomic occupation of B2 structure is one Ti atom exchange with the nearest neighboring Mn atom from the view of lowest energy principle.This disordered exchange sites(Mn-Ti) and the excess Mn atoms occupying the Ti sites(MnTi)could reduce the nearest Mn-Mn distance,resulting in the anti ferromagnetic state in the austenitic and martensitic phases of the alloys.The total magnetic moment of the alloy decreases with the increasing Mn content;it is ascribed to the antiferromagnetic magnetic moments of the excess Mn atoms.When x=0,the alloy does not undergo martensitic transformation since the austenite has absolute phase stability.The martensitic transformation will occur during cooling process for x=1 or 2,owing to the energy difference between the austenite and the martensite could provide the driving force for the phase transformation.The elastic properties of the cubic austenitic phase for the Ni2 MnTi alloy is calculated,and the results reveal the reason why Ni-Mn-Ti alloy has excellent mechanical properties.The origin of martensitic transformation and magnetic properties was discussed based on the electronic density of states. 展开更多
关键词 Ni-Mn-Ti First-principles calculations Martensitic transformation b2 partial disordered structure Elastic properties
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STRUCTURE IN THE PRECORE REGION OF HEPATITIS B CORE GENE AFFECTING ITS EXPRESSION IN E.coil
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作者 马贤凯 丁广治 +4 位作者 石成华 左平 逯好英 卢秀桂 黄翠芬 《Science China Chemistry》 SCIE EI CAS 1987年第11期1190-1198,共9页
Restriction fragments of HBV-DNA, cleaved by endonuclease HhaI,containing HBcAg gene were trimmed by BAL-31 exonuclease to remove different lengths of the precore sequence.They were inserted into plasmid pUR222 at Eco... Restriction fragments of HBV-DNA, cleaved by endonuclease HhaI,containing HBcAg gene were trimmed by BAL-31 exonuclease to remove different lengths of the precore sequence.They were inserted into plasmid pUR222 at EcoRI site through synthetic linker ligation. Transformants in E.coli BMH7118 showing different levels of HBcAg gene expression were screened and analyzed for their nucleotide sequences in the junction region both by Maxam and Gilbert’s chemical degradation method and by M13 chain termination method. Results of sequence analysis of different transformants revealed a partial palindromic (loop and stem) structure, at -7 to -35 nucleotide with regard to ATG of the HBcAg gene as position +1, which has dramatic effect on the level of expression of the inserted gene using the same promoter,SD sequence and identical N-terminus.The amount of HBcAg synthesized differed from 9% in the high expressing plasmid to less than 0.01% of the total cell proteins in the low expressing transformants.The findings 展开更多
关键词 HbeAg HbcAg structure IN THE PRECORE REGION OF HEPATITIS b CORE GENE AFFECTING ITS EXPRESSION IN E.coil
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Influence of tension-twisting deformations and defects on optical and electrical properties of B,N doped carbon nanotube superlattices 被引量:1
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作者 刘贵立 姜艳 +2 位作者 宋媛媛 周爽 王天爽 《Journal of Semiconductors》 EI CAS CSCD 2016年第6期33-38,共6页
As the era of nanoelectronics is dawning,CNT(carbon nanotube),a one-dimensional nano material with outstanding properties and performances,has aroused wide attention.In order to study its optical and electrical prop... As the era of nanoelectronics is dawning,CNT(carbon nanotube),a one-dimensional nano material with outstanding properties and performances,has aroused wide attention.In order to study its optical and electrical properties,this paper has researched the influence of tension-twisting deformation,defects,and mixed type on the electronic structure and optical properties of the armchair carbon nanotube superlattices doped cyclic alternately with B and N by using the first-principle method.Our findings show that if tension-twisting deformation is conducted,then the geometric structure,bond length,binding energy,band gap and optical properties of B,N doped carbon nanotube superlattices with defects and mixed type will be influenced.As the degree of exerted tension-twisting deformation increases,B,N doped carbon nanotube superlattices become less stable,and B,N doped carbon nanotube superlattices with defects are more stable than that with exerted tension-twisting deformations.Proper tension-twisting deformation can adjust the energy gap of the system;defects can only reduce the energy gap,enhancing the system metallicity;while the mixed type of 5%tension,twisting angle of 15° and atomic defects will significantly increase the energy gap of the system.From the perspective of optical properties,doped carbon nanotubes may transform the system from metallicity into semi-conductivity. 展开更多
关键词 b and N doped carbon nanotubes defects tension-twisting deformation electronic structure optical properties
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Cytochrome P450 BM3 of Bacillus megaterium-A possible endosulfan biotransforming gene
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作者 Muhil Vannan Seralathan Saravanadevi Sivanesan +4 位作者 Amit Bafana Sanjay Madanchand Kashyap Arrigo Patrizio Kannan Krishnamurthi Tapan Chakrabarti 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第11期2307-2314,共8页
Computing chemistry was applied to understand biotransforrnation mechanism of an organochlorine pesticide, endosulfan. The stereo specific metabolic activity of human CYP-2B6 (cytochrome P450) on endosulfan has been... Computing chemistry was applied to understand biotransforrnation mechanism of an organochlorine pesticide, endosulfan. The stereo specific metabolic activity of human CYP-2B6 (cytochrome P450) on endosulfan has been well demonstrated. Sequence and structural similarity search revealed that the bacterium Bacillus megaterium encodes CYP-BM3, which is similar to CYP-2B6. The functional similarity was studied at organism level by batch-scale studies and it was proved that B. megaterium could metabolize endosulfan to endosulfan sulfate, as CYP-2B6 does in human system. The gene expression analyses also confirmed the possible role of CYP-BM3 in endosulfan metabolism. Thus, our results show that the protein structure based in-silico approach can help us to understand and identify microbes for remediation strategy development. To the best of our knowledge this is the first report which has extrapolated the bacterial gene for endosulfan biotransformation through in silico prediction approach for metabolic gene identification. 展开更多
关键词 Protein structure similarity CYP-2b6 CYP-bM3 Endosulfan
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Structural elucidation, theoretical investigation using DFT calculations,thermal and dielectric analyses of new zinc(Ⅱ) based inorganic–organic hybrid
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作者 Nejla Chihaoui Besma Hamdi Ridha Zouari 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第3期642-650,共9页
A novel interesting d^(10) metal hybrid, [1,2-C_6H_(10)(NH_3)_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate(II) was grown, structurally characterized and their vibrational as well as thermal and diele... A novel interesting d^(10) metal hybrid, [1,2-C_6H_(10)(NH_3)_2]ZnCl_4; 1,2-diammoniumcyclohexane tetrachlorozincate(II) was grown, structurally characterized and their vibrational as well as thermal and dielectric proprieties were studied. A preliminary single crystal X-ray diffraction structural analysis has revealed that the latter crystallizes in the monoclinic system(space group C2/c). Its unit cell dimensions are a = 32.394(9) ?, b = 12.217(4) ?, c = 10.175(3) ?, β = 97.852(13)° with Z = 12 and the refinement converged to R = 0.034 and ωR = 0.065. Hirshfeld surface analyses, especially d_(norm)surface and fingerprint plots were used for decoding intermolecular interactions in the crystal network. The optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3 LYP method with the Lan L2 DZ basis set. The thermal and dielectric analyses suggested the presence of ferroelectric phase transition at 314 K. 展开更多
关键词 d^(10) metal hybrid Chlorozincate(Ⅱ) Crystal structure DFT/b3LYP/Lan L2DZ FT-IR Raman scattering Dielectric analyses
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Cosmic-ray helium nuclei measurement with the calorimeter of the Alpha Magnetic Spectrometer
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作者 Feng-ze Zhang Zhi-Cheng Tang +6 位作者 Zu-Hao Li Cheng Zhang Ze-Tong Sun Jia-Yu Hu Shang-Lin Li Guo-Ming Chen He-Sheng Chen 《Radiation Detection Technology and Methods》 CSCD 2022年第3期427-432,共6页
Purpose The distributions of energy responses of helium measured by the electromagnetic calorimeter(ECAL)of Alpha Magnetic Spectrometer(AMS-02)in Monte-Carlo do not agree with those in real data,thus using energy resp... Purpose The distributions of energy responses of helium measured by the electromagnetic calorimeter(ECAL)of Alpha Magnetic Spectrometer(AMS-02)in Monte-Carlo do not agree with those in real data,thus using energy response matrix obtained from Monte-Carlo to measure the cosmic ray helium spectrum is not correct.Therefore,the spectrum measured with ECAL based on raw Monte-Carlo would be different from the real one.The purpose is to correct the response matrix to measure helium spectrum with ECAL.Methods The energy measured by ECAL of AMS-02 provides in-flight correction for the energy response matrix in Monte-Carlo.Results The spectrum based on corrected response matrix is consistent with the AMS collaboration published result.Conclusions It is feasible to measure helium spectrum with ECAL with corrected energy response matrix. 展开更多
关键词 Cosmic rays Helium spectrum Electromagnetic calorimeter Monte Carlo simulation Fig.1 a The structure of ECAL b The indication of PMTs in one superlayer
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