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641.
Yusuke HirasawaRyo Matsuya Khozirah ShaariNordin Hj Lajis Nahoko UchiyamaYukihiro Goda Hiroshi Morita 《Tetrahedron letters》2012,53(31):3971-3973
Novel C16N2-type Lycopodium alkaloids consisting of a decahydroquinoline with an aminohexyl side chain, lycobelines A-C (1-3), were isolated from the club moss of Huperzia goebelii, and their structures and relative stereochemistry were elucidated on the basis of spectroscopic data and chemical correlations. 相似文献
642.
A new dimeric Lythraceae alkaloid with a cyclobutane ring, sarusubine A (1), has been isolated from the leaves of Lagerstroemia subcostata, and the structure and stereochemistry were elucidated by spectroscopic data. 相似文献
643.
Chengjian Tan Yingtong Di Ye Wang Suo Gao Ningchuan Kong Jianxin Zhang Chunshun Li Xiaojiang Hao 《Tetrahedron letters》2008,49(21):3376-3379
Oldhamine A, a novel alkaloid with an unusual cyclopentadienyl anion in the fused-pentacyclic skeleton was isolated from the twigs of Daphniphyllum oldhami. The structure of oldhamine A was elucidated based on the spectroscopic data and the single-crystal X-ray diffraction crystallography. It is the first X-ray diffraction of the Daphniphyllum alkaloids with nitrogen-containing two pentacyclic rings. The inter-conversion between cyclopentadienyl anion and conjugated enolic unit was also conducted. 相似文献
644.
645.
我国二萜生物碱化学的研究进展(1986~1992) 总被引:3,自引:0,他引:3
本文综述了我国1986~1992年之间在二萜生物碱化学反应方面的研究。 相似文献
646.
Pranesh Kumar Atul Rawat Amit K. Keshari Ashok K. Singh Siddhartha Maity Arnab De 《Natural product research》2016,30(4):460-463
The present study was undertaken to investigate the antiproliferative action of isolated M1 (6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) from Mucuna pruriens seeds using human hepatic carcinoma cell line (Huh-7 cells). Initially, docking studies was performed to find out the binding affinities of M1 to caspase-3 and 8 enzymes. Later, cytotoxic action of M1 was measured by cell growth inhibition (MTT), followed by caspase-3 and 8 enzymes assay colorimetrically. Our results collectively suggested that M1 had strong binding affinity to caspase-8 in molecular modelling. M1 possessed antiproliferative activity on Huh-7 cells (EC50 = 13.97 μM) and also inhibited the action of caspase-8 enzyme, signified process of apoptosis. M1 was active against Huh-7 cells that may be useful for future hepatic cancer treatment. 相似文献
647.
Enantioseparation of chiral sulfonates by liquid chromatography and subcritical fluid chromatography
Tert‐butylcarbamoyl‐quinine and ‐quinidine weak anion‐exchange chiral stationary phases (Chiralpak® QN‐AX and QD‐AX) have been applied for the separation of sodium β‐ketosulfonates, such as sodium chalconesulfonates and derivatives thereof. The influence of type and amount of co‐ and counterions on retention and enantioresolution was investigated using polar organic mobile phases. Both columns exhibited remarkable enantiodiscrimination properties for the investigated test solutes, in which the quinidine‐based column showed better enantioselectivity and slightly stronger retention for all analytes compared to the quinine‐derived chiral stationary phase. With an optimized mobile phase (MeOH, 50 mM HOAc, 25 mM NH3), 12 of 13 chiral sulfonates could be baseline separated within 8 min using the quinidine‐derivatized column. Furthermore, subcritical fluid chromatography (SubFC) mode with a CO2‐based mobile phase using a buffered methanolic modifier was compared to HPLC. Generally, SubFC exhibited slightly inferior enantioselectivities and lower elution power but also provided unique baseline resolution for one compound. 相似文献
648.
A novel Lycopodium alkaloid, lycopladine H (1), with a fused-tetracyclic ring system consisting of an azocane ring connected to a [2,2,2]-bicyclooctane ring and a 3-piperidone ring, was isolated from the club moss Lycopodium complanatum. The structure and relative stereochemistry of 1 were elucidated on the basis of spectroscopic data. 相似文献
649.
Chen Y Shao C Huang Z Zhang Y Cai X She Z Zhou S Lin Y 《Magnetic resonance in chemistry : MRC》2009,47(1):92-95
The structure elucidations and complete (1)H and (13)C NMR assignments are reported for two new natural products: 3-benzylidene-8,8a-dihydroxy-2-methyl-hexahydro-pyrrolo[1,2-a]pyrazine-1,4-dione(1) and 4-hydroxy-6-(hydroxy-phenyl-methyl)-N-(3-methyl-butyryl)-nicotinamide (2). Both of these secondary metabolites were isolated from the fermentation medium of a Mangrove endophytic fungus. High resolution electron impact mass spectrometry (HREIMS), FT-IR Spectroscopy and NMR experiments including gCOSY, gHMQC, gHMBC and NOE were used for determination of the structures and assignments of the amide alkaloids. 相似文献
650.
Two new C_(19)-diterpenoid alkaloids from roots Aconitum hemsleyanium var. atropurpureum 总被引:2,自引:0,他引:2
Pei Tang Dong Lin Chen Xi Xian Jian Feng Peng Wang Department of Chemistry of Medicinal Natural Products West China College of Pharmacy Sichuan University Chengdu China 《中国化学快报》2007,18(6):704-707
A new franchetine-type C19-diterpenoid alkaloid 3-hydroxyfranchetine 1 and a new aconitine-type C19-diterpenoid alkaloid atropurpursine 2 have been isolated from the roots of Aconitum hemsleyanium var. atropurpureum. The structures of these new alkaloids were established on the basis of spectral data. 相似文献