检索结果-南通市图书馆

Phytochemical isolation, antimicrobial activity and pharmacological studies of Clausena dentata (willd.) roem.

在线全文

学校读者我要写书评

暂无评论

Phytochemical isolation, antimicrobial activity and pharmaco...

Synchrotron radiation studies of the orientation of thin silicon phthalocyanine dichloride film on HOPG substrate

The 3～(rd) International Conference on Natural Products :Natural Products -a Must for Human Survival ABSTRACTS

作者： N.Raman R.Kamaraj S.Chattopadhyay C.J.Chintalwar centre for Advanced Studies in Botany University of Madras Guindy campus Chennai -600 025 India. College of Pharmacy Sri Ramachandra Medical College and research Institute(Deemed University) Porur Chennai -600 116 India Bio-organic Division baba atomic research centre Trombay Mumbai -400 085 India. Bio-organic Division baba atomic research centre Trombay Mumbai -400 085 India.

The major advantage of natural products for random screening is the structural diversity provided by most available combinatorial approaches based on heterocyclic compounds. Clausena (Rutaceae) is a genus of about 23 species of unarmed trees and shrubs, mainly growing Indo-Malayan with a few in China, Africa and Australia. Ten species are known to grow in India, of which 5 are of economically importance. C. dentata, a plant of immense medicinal value was taken for detailed study for phytochemical, antibacterial and pharmacological investigations. The dry powder of the stem bark was extracted successively with 3 solvents viz., hexane, chloroform and methanol. The extracts were subjected to column chromatography. Four compounds were isolated. Two coumarins, 3-(1,1-dimethylallyl) xanthyletin and dentatin were isolated from hexane extract. The chloroform extract yielded another coumarin, nordentatin. An alkaloid, carbazole was isolated from methanol extract. All the compounds were identified based on spectral studies such as GC, UV, IR, NMR and MS. This investigation is the first report of the dentatin and nordentatin stem bark of C. dentata. The 13C-NMR studies of dentatin and nordentatin have been carried out for the first time. The existence of carbazole alkaloid is reported for the first time in C. dentata. The compounds showed significant antibacterial activity against E. coli, Salmonella typhi, Klebsiella pneumoniae, Vibrio cholerae and Staphylococcus aureus. The activity by dentatin and nordentatin against Vibrio cholerae was comparable with standard antibiotic ciprofloxacin. All the 3 extracts and the 4 isolated compounds were tested for various pharmacological activities such as anti-inflammatory, analgesic and hepatoprotective effect for extracts, anticoagulant, antiplatelet aggregation, prothrombin time and effect on perfused frog heart for isolated compounds. The present study is the first report for pharmacological activities of C. dentata.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Physics C 2008年第9期32卷 769-772页

作者：邓居智陈荣 SEKIGUCHI Tetsuhiro baba Yuji HIRAO Norie HONDA Mitsunori Key Laboratory of Nuclear Resources and Environment (East China Institute of Technology) Ministry of Education Synchrotron Radiation research Center Japan Atomic Energy Agency

Thin silicon phthalocyanine dichloride films on HOPG were prepared and the sample was heated in the vacuum with laser. The thickness of the thin sample on HOPG was checked by X-ray photoemission spectroscopy. The orientation of the molecules in respect to the substrate plane was investigated by measuring the silicon K-edge near edge X-ray absorption fine structure （NEXAFS）. In the NEXAFS spectra of the thin sample, two clear peaks which were assigned to Is → σ^＊Si-N and 1s→ σ^＊Si-Cl appeared around 1847.2 eV and 1843.1 eV respectively. The intensities of the resonance peaks showed strong polarization dependence. A quantitative analysis of the polarization dependence revealed that the Si-N bond tended to lie down while the Si-Cl bond was out of the molecular plane.

关键词： near edge X-ray absorption fine structure (NEXAFS) orientation silicon phthalocyanine dichloride polarization dependence

Contracted interlayer distance in graphene/sapphire heterostructure

在线全文

学校读者我要写书评

暂无评论

Nano research 2015年第5期8卷 1535-1545页

作者： Shiro Entani Liubov Yu. Antipina Pavel V. Avramov Manabu Ohtomo Yoshihiro Matsumoto Norie Hirao Iwao Shimoyama Hiroshi Naramoto Yuji baba Pavel B. Sorokin Seiji Sakai Advanced Science research Center Japan Atomic Energy Agency Tokai Ibaraki 319-1195 Japan Technological Institute for Superhard and Novel Carbon Materials Troitsk Moscow 142190 Russia Moscow Institute of Physics and Technology Dolgoprudny Moscow 141700 Russia Siberian Federal University 79 Svobodniy pr. Krasnoyarsk 660041 Russia Ouantum Beam Science Directorate Japan Atomic Energy Agency Tokai Ibaraki 319-1195 Japan National University of Science and Technology MISiS Moscow 119049 Russia

Direct growth of graphene on insulators is expected to yield significant improvements in performance of graphene-based electronic and spintronic devices. In this study, we successfully reveal the atomic arrangement and electronic properties of a coherent heterostructure of single-layer graphene and α-Al2O3（0001）. The analysis of the atomic arrangement of single-layer graphene on α-Al2O3（0001） revealed an apparentcontradiction. The in-plane analysis shows that single-layer graphene grows not in a single-crystalline epitaxial manner, but rather in polycrystalline form, with two strongly pronounced preferred orientations. This suggests relatively weak interfacial interactions are operative. However, we demonstrate that unusually strong physical interactions between graphene and α-Al2O3（0001） exist, as evidenced by the small separation between the graphene and the α-Al2O3（0001） surface. The interfacial interaction is shown to be dominated by the electrostatic forces involved in the graphene n-system and the unsaturated electrons of the topmost O layer of α-Al2O3（0001）, rather than the van der Waals interactions. Such features causes graphene hole doping and enable the graphene to slide on the α-Al2O3（0001） surface with only a small energy barrier despite the strong interfacial interactions.

关键词： graphene sapphire chemical vapor deposition graphene/insulator interface

Synthesis of Hexagonal Boron Carbonitride without Nitrogen Void Defects

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Materials Sciences and Applications 2015年第5期6卷 353-359页

作者： Md. Abdul Mannan Yuji baba Tetsuya Kida Masamitsu Nagano Hideyuki Noguchi Department of Chemistry University of Rajshahi Rajshahi Bangladesh Synchrotron Radiation research Unit Quantum Beam Science Directorate Japan Atomic Energy Agency Ibaraki-ken Japan Sector of Fukushima research and Development Japan Atomic Energy Agency Fukushima-shi Japan Department of Chemistry and Applied Chemistry Saga University Honjyo Japan

The synthesis and structure of hexagonal boron carbonitride (h-BCN) film on polycrystalline diamond surface were reported. Polycrystalline diamond and/or diamond-like carbon were first fabricated on Si (100) and then diamond like carbon was used as substrate. The deposition was performed by radio frequency plasma enhanced chemical vapor deposition. In order to reduce the content of nitrogen void defects, the deposition was performed at the high temperature of 950°C under the working pressure of 2.6 Pa. The typical sample with atomic composition of B31 C37 N26 O6 in the h-BCN lattice was characterized by X-ray photoelectron spectroscopy. The fine structure of the film was studied by near-edge X-ray absorption fine structure (NEXAFS) measurements. The B K-edge and N K-edge of NEXAFS spectra revealed that the synthesized h-BCN film had the ideal honeycomb- like BN3 configuration without nitrogen void defects.

关键词： h-BCN Defect Chemical Vapor Deposition XPS NEXAFS

Hexagonal Nano-Crystalline BCN Films Grown on Si (100) Substrate Studied by X-Ray Absorption Spectroscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Materials Sciences and Applications 2013年第5期4卷 11-19页

作者： Md. Abdul Mannan Yuji baba Norie Hirao Tetsuya Kida Masamitsu Nagano Hideyuki Noguchi Department of Chemistry and Applied Chemistry Faculty of Science and Engineering Saga University Saga Japan Department of Chemistry and Applied Chemistry Faculty of Science and Engineering Saga University Saga Japan Synchrotron Radiation research Unit Quantum Beam Science Directorate Japan Atomic Energy Agency Ibaraki Japan Synchrotron Radiation research Unit Quantum Beam Science Directorate Japan Atomic Energy Agency Ibaraki Japan

Hexagonal nano-crystalline boron carbonitride (h-BCN) films grown on Si (100) substrate have been precisely investigated. The films were synthesized by radio frequency plasma enhanced chemical vapor deposition using tris-dimethylamino borane as a single-source molecular precursor. The deposition was performed by setting RF power at 400 - 800 W. The reaction pressure was at 2.6 Pa and the substrate temperature was recorded at 700°C - 800°C. Formation of the nano-crystalline h-BCN compound has been confirmed by X-ray diffraction analysis. The diffraction peaks at 26.3° together with a small unknown peak at 29.2° were elucidated due to the formation of an h-BCN structure. The films composed of B, C, and N atoms with different B-N, B-C, C-N chemical bonds in forming the sp2-BCN atomic configuration studied by X-ray photoelectron spectroscopy. Orientation and local structures of the h-BCN hybrid were studied by near-edge X-ray absorption fine structure (NEXAFS) measurements. The dominant presence of p* and s* resonance peaks of the sp2-hybrid orbitals in the B K-edge NEXAFS spectra revealed the formation of the sp2-BCN configuration around B atoms like-BN3 in h-BN. The orientation was suggested on the basis of the polarization dependence of B K-edge and N K-edge of the NEXAFS spectra.

关键词： Nano-Crystalline h-BCN Films Synchrotron Radiation XPS NEXAFS Orientation

Ion Beam Surface Modification of Y-TZP and Effects of Subsequent Annealing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5B期25卷 1032-1036页

作者： Y.Motohashi T.Shibata S.Harjo T.Sakuma M.Ishihara S.baba K.Sawa research Center for Superplasticity Ibaraki University Nakanarusawa 4-12-1 Hitachi Ibaraki 316-8511 Japan Oarai research Establishment JAERI Oarai Higashiibaraki-gun Ibaraki 311-1394 Japan

Tetragonal zirconia polycrystals containing 3 mol% yttria (3Y-TZP), which show Superplasticity at high temperatures, were irradiated using 130 MeV Zr+" ions in the TANDEM accelerator facility at Tokai research Establishment, JAERI. The irradiation induced atomic displacement damage was analyzed by TRIM code. Changes in the mechanical properties and fracture behavior caused by the ion irradiation and the effects of subsequent annealing were studied. The distribution of micro-indentation depth as a function of the indentation position from the irradiated surface to the specimen interior was also examined. The occurrence of compressive residual stresses and increases in hardness and fracture toughness were found in the as-irradiated surface region of the specimen. The subsequent annealing revealed that these quantities were decreased gradually with raising the annealing temperature. Probable causes of the generation of the residual stress and the changes in mechanical properties and fracture mode due to the irradiation are discussed.

关键词： ion beam surface modification annealing 3Y-TZP residual stress mechanical properties micro-indentation Superplasticity

Novel evidence for the σ-bond linear-chain molecular structure in ^(14)C

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2021年第8期45卷 71-75页

作者： Han-zhou Yu Jing Li Yan-Lin Ye BiaoYang Cheng-JianLin Hui-Ming Jia Jian-Ling Lou Xiao-Fei Yang T.baba Qi-Te Li Yu-Cheng Ge Zhi-Huan Li Hui Hua Jin-Yan Xu Zai-Hong Yang Jun Feng Hong-Liang Zang Qiang Liu Wei Jiang Yang Liu Jing-Jing Li Wei Liu Shi-Wei Bai Jie Chen Jia-Xing Han Jia-Hao Chen Kai Ma Dong-Xi Wang Lei Yang Nan-Ru Ma LI-Jie Sun School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China FRIB/NSCL Laboratory Michigan State UniversityEast LansingMichigan 48824USA China Institute of atomic Energy Beijing 102413China Kitami Institute of Technology 090-8507 KitamiJapan research Center for Nuclear Physics(RCNP) Osaka University10-1 MihogaokaIbarakiOsaka 567-0047Japan Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China

A multi-nucleon transfer and cluster decay experiment,^(7)Li(^(11)B,^(14)C^(*)→α+^(10)Be)α,is conducted at an incident beam energy of 55 *** reaction channel has a significantly large 0-value,which favors populating the high lying resonant states in ^(14)*** decay paths,from these resonances to various states of the final nucleus ^(10) Be,can be selected,owing to the experimentally achieved optimal resolution of the Q-value spectrum.A number of resonant states are reconstructed from the forward emitting 10Be+α fragments,and their major molecular structures can be detected according to the selective decay paths and relative decay widths.A state at 22.4(2)MeV validates the previously measured and theoretically predicted band head of the positive-parity σ-bond linear-chain mo-lecular *** additional resonances at 22.9(2)and 24.2(2)MeV are identified and consistent with the predicted 2^(+) and 4^(+) members of the same molecular band,thus providing novel evidences for the existence of the exotic clustering chain structure in neutron-rich carbon isotopes.A few high energy resonances,which also indicate the presence of the σ-bond molecular structure,are observed;however,further studies are still required to clarify their ascription in band systematics.

关键词： linear-chain state reaction 0-value transfer reaction cluster decay relative branching ratio

Nutritional and Anti-Nutrient Composition of Three Kola Nuts(Cola nitida,Cola acuminata and Garcinia kola)Produced in Benin

在线全文

学校读者我要写书评

暂无评论

Food and Nutrition Sciences 2015年第15期6卷 1395-1407页

作者： Durand Dah-Nouvlessounon Adolphe Adjanohoun Haziz Sina Pacome A.Noumavo Nafan Diarrasouba Charles Parkouda Yann E.Madodé Mamoudou H.Dicko Lamine baba-Moussa Laboratoire de Biologie et de Typage Moléculaire en Microbiologie FASTUniversitéd’Abomey-CalaviCotonouBénin centre de Recherches Agricoles Sud Institut National des Recherches Agricoles du BéninAttogonBénin UFR des Sciences Biologiques UniversitéPéléforo Gon CoulibalyKorhogoCote d’Ivoire Département de Technologie Alimentaire IRSAT/CNRSTDTAOuagadougouBurkina Faso Département de Nutrition et Sciences Alimentaires FSAUniversitéd’Abomey-CalaviCotonouBénin Laboratoire de Biochimie Alimentaire EnzymologieBiotechnologie Industrielle et BioinformatiqueUniversitéde OuagadougouOuagadougouBurkina Faso

Kola nuts were regularly chewed by West Africans and Beninese in particularly. The aim of this study was to investigate nutritional and anti-nutrient content of three Benin’s kola nuts (Cola nitida, Cola acuminata and Garcinia kola). Proximate composition of the three species of kola nuts was assessed using standard analytical AOAC methods. Phenolics and flavonoids contents were determined by Folin-Ciocalteu and aluminum trichloride methods, respectively. Mineral composition was determined by atomic Absorption Spectrometry method. Free and total amino acids were separated and quantified by HPLC. Protein content of the three kola nuts ranges from 4.95% (G. kola) to 10.64% (C. acuminata) whereas fat content ranges from 0.2 ± 0.00 (C. nitida) to 2.5 ± 0.42 (G. kola). Total phenolics abounded (2444.96 ± 81.56 μg Eq AG/100g) in C. acuminata, while flavonoids predominated (561.69 ± 22.10 μgEqQ/100g) in G. kola. The three species are a good source of magnesium and a copper provider was lowest in C. nitida (0.59 ± 0.08 mg/g) and in C. acuminata (0.65 ± 0.02 mg/g). The dominant total essential amino acids were threonine (C. acuminata) and methionine (C. acuminata and G. kola), while the predominant non-essential total amino acids according to species were arginine (C. nitida and G. kola), proline (C. acuminata) and cysteine (G. kola). For the anti-nutrients factors, saponins were in great proportion (8.33% ± 0.25%), while the oxalates were in small proportion (0.44% ± 0.04%). The three species have an interesting nutritional composition, but these seeds have the relatively lowest amino acids content.

关键词： Kola Nuts Polyphenolic Compound Micronutrient Benin