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81.
A new neutral ruthenium(II) complex of dihydro-bis(1-pyrazolyl) borate is synthesised by the reaction of RuCl2(PPh3)3 with the ligand in methanol and is characterised on the basis ofir and31P{1H}nmr spectra. 相似文献
82.
Cyclopropanation of active methylene compounds has been achieved in good yields with ethylene carbonate as the cyclopropanating agent in the presence of a simple base. 相似文献
83.
Veera Reddy Arava Sreenivasula Reddy Bandatmakuru Sashibhushan Malreddy Narayanaswamy Golla 《合成通讯》2013,43(11):1565-1571
Efficient methods for the syntheses of amines 6b and 9b, the major metabolites of the antidepressant drugs amitriptyline 1a and nortriptyline 1b, are described. 相似文献
84.
Nucleophilic substitution reactions of 2,3-epoxy alcohols, easily prepared via Sharpless asymmetric epoxidation chemistry, offer access to a wide variety of enantiomerically pure compounds. In this communication, we describe the use of a Payne rearrangement to control regioselectivity in the ring-opening of a series of 2,3-epoxy alcohols with dimethylsulfoxonium methylide to yield diastereomerically and/or enantiomerically pure disubstituted tetrahydrofuran rings. The factors influencing the success and substitution pattern of the THF ring products are discussed, including steric, electronic, and solvent effects. 相似文献
85.
Sulfamic acid (SA) is a bi-functional, cost-effective and reusable green catalyst for the synthesis of 4- (pyrazol-4-yl)methylenepyrazol-5(4H)-one derivatives by one-pot, three-component condensation of pyrazol-4-carbaxaldehydes, β-ketoesters and phenyl hydrazine (Route-I). In addition to this method, another simple condensation of pyrazol-4-carbaxaldehydes with pyrazolone in the presence of SA under the solvent-free condition in good yield is reported. The merits of these protocols are mild conditions, non-aqueous workup, high yields, easy availability of the catalyst, no chromatographic separation and inexpensive solid acid catalyst. Furthermore, SA could be recycled and reused for five times without losing its catalytic activity. 相似文献
86.
Poonam Kalhotra Veera C. S. R. Chittepu Guillermo Osorio-Revilla Tzayhri Gallardo-Velazquez 《Molecules (Basel, Switzerland)》2021,26(4)
Currently, SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has infected people among all countries and is a pandemic as declared by the World Health Organization (WHO). SARS-CoVID-2 main protease is one of the therapeutic drug targets that has been shown to reduce virus replication, and its high-resolution 3D structures in complex with inhibitors have been solved. Previously, we had demonstrated the potential of natural compounds such as serine protease inhibitors eventually leading us to hypothesize that FDA-approved marine drugs have the potential to inhibit the biological activity of SARS-CoV-2 main protease. Initially, field-template and structure–activity atlas models were constructed to understand and explain the molecular features responsible for SARS-CoVID-2 main protease inhibitors, which revealed that Eribulin Mesylate, Plitidepsin, and Trabectedin possess similar characteristics related to SARS-CoVID-2 main protease inhibitors. Later, protein–ligand interactions are studied using ensemble molecular-docking simulations that revealed that marine drugs bind at the active site of the main protease. The three-dimensional reference interaction site model (3D-RISM) studies show that marine drugs displace water molecules at the active site, and interactions observed are favorable. These computational studies eventually paved an interest in further in vitro studies. Finally, these findings are new and indeed provide insights into the role of FDA-approved marine drugs, which are already in clinical use for cancer treatment as a potential alternative to prevent and treat infected people with SARS-CoV-2. 相似文献
87.
The synthesis and characterisation of ruthenium(II) complexes with 2-amidobenzimidazoles are reported. The complexes RuCl2(DMSO)4 and RuCl2(PPh3) react with 2-(acetamido)benzimidazole (AB) and 2-(benzamido)benzimidazole (BB) it acetone to give products of the type [Ru(L)2(N−O)2]Cl2 [L=DMSO, PPh3, N−O=AB, BB). The displacement reactions are faster in the case of methyl (AB) than phenyl (BB) substituted ligands. The
ligands are bifunctional chelating agents coordinating through the tertiary nitrogen of benzimidazole ring and amide oxygen.
The complexes are characterised based on their elemental analysis, conductivity data, infrared,1H and31P nmr spectra. Acis-geometry is proposed for all the complexes reported. 相似文献
88.
Matthew W. Brenner Veera M. Boddu Ashok Kumar 《Applied Physics A: Materials Science & Processing》2014,117(4):1849-1857
This study focuses on the effect of carbon precursor on the carbon nanotube (CNT) morphology and energy dissipation. Benzene, toluene, and m-xylene were used as carbon precursors for the synthesis of CNT forests following a chemical vapor deposition process. The results indicate that substituents on the benzene ring increase entanglement in the CNT forests. The absorbed energy was slightly greater for CNT forests synthesized using m-xylene than for toluene, but was much smaller for benzene. When compressed to a strain of 0.67, the toluene CNTs absorbed more energy than the m-xylene CNTs. The restitution was much higher for the forests synthesized with m-xylene than toluene while it further decreased for the forests made with benzene. A strong correlation is also observed between the average diameter of the CNTs and the number of methyl substituents on the benzene ring. The control of the entanglement of the CNT forests can potentially be used to design high energy absorbing composites for blast energy dissipation. 相似文献
89.
Subbarami Reddy Sanjeeva Rao Jadhav Parashuram G. Punnaiah V. Sridhar Veera Bhadraiah 《辐射效应与固体损伤》2013,168(4):411-415
Methacrylamide-2-acrylamido-2-methylpropanesulphonic acid (MA-AMPS) (80:20) is subjected to n -irradiation and the generated free radicals are identified by the electron spin resonance (ESR) technique. The ESR spectrum "obser"ved for MA-AMPS (80:20) has shown a complex line shape, indicating the presence of more than one free radical. Computer simulations are employed to unravel the radicals responsible for the ESR spectrum. Radical "identification has been done with the magnetic parameters employed during computer simulation. The observed ESR spectrum of the copolymer is simulated to be a superposition of component quartet, quintet and singlet spectra. The component spectra are assigned to ~CH 2 - . (CONH 2 )-CH 2 ~ or ~CH 2 - . H-CH 2 ~, . H 3 radicals, "respectively. The possibility of formation of such radicals in the sample material has been discussed. 相似文献
90.
Computer readable databases have become an integral part of chemical research right from planning data acquisition to interpretation of the information generated. The databases available today are numerical, spectral and bibliographic. Data representation by different schemes--relational, hierarchical and objects--is demonstrated. Quality index (QI) throws light on the quality of data. The objective, prospects and impact of database activity on expert systems are discussed. The number and size of corporate databases available on international networks crossed manageable number leading to databases about their contents. Subsets of corporate or small databases have been developed by groups of chemists. The features and role of knowledge-based or intelligent databases are described. 相似文献