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961.
N. Koteeswara Reddy K. Ramesh R. Ganesan K.T. Ramakrishna Reddy K.R. Gunasekhar E.S.R. Gopal 《Applied Physics A: Materials Science & Processing》2006,83(1):133-138
Tin sulphide films were grown at different substrate temperatures by a thermal co-evaporation technique. The crystallinity of the films was evaluated from X-ray diffraction studies. Single-phase SnS films showed a strong (040) orientation with an orthorhombic crystal structure and a grain size of 0.12 μm. The films showed an electrical resistivity of 6.1 Ω cm with an activation energy of 0.26 eV. These films exhibited an optical band gap of 1.37 eV and had a high optical absorption coefficient (>104 cm-1) above the band-gap energy. The results obtained were analysed to evaluate the potentiality of the co-evaporated SnS films as an absorber layer in solar photovoltaic devices. PACS 78.40.Fy; 68.60.-p; 61.10.Nz; 68.55.-a; 78.66.-w 相似文献
962.
Manab Sharma Bhaskar J. Sarmah Pradip Bhattacharyya Ramesh C. Deka Dipak K. Dutta 《应用有机金属化学》2007,21(4):255-263
The complexes [Rh(CO)2ClL]( 1 ), where L = 2‐aminophenol ( a ), 3‐aminophenol ( b ) and 4‐aminophenol ( c ), have been synthesized and characterized. The ligands are coordinated to the metal centre through an N‐donor site. The complexes 1 undergo oxidative addition ( OA ) reactions with various alkyl halides ( RX ) like CH3I, C2H5I and C6H5CH2Cl to produce Rh(III) complexes of the type [Rh(CO)(COR)XClL], where R = ? CH3( 2 ), ? C2H5( 3 ), X = I; R = C6H5CH2? and X = Cl ( 4 ). The OA reaction with CH3I follows a two‐stage kinetics and shows the order of reactivity as 1b > 1c > 1a . The minimum energy structure and Fukui function values of the complexes 1a–1c were calculated theoretically using a DND basis set with the help of Dmol3 program to substantiate the observed local reactivity trend. The catalytic activity of the complexes 1 in carbonylation of methanol, in general, is higher (TON 1189–1456) than the species [Rh(CO)2I2]? (TON 1159). Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
963.
Ramesh M. Singru 《Hyperfine Interactions》2009,188(1-3):91-93
An attempt is made to outline the new challenges faced by the community of Mössbauer spectroscopists with a special focus on India. Some suggestions are made to overcome these challenges. 相似文献
964.
Biswanath Das Joydeep BanerjeeR. Ramu Rammohan PalN. Ravindranath C. Ramesh 《Tetrahedron letters》2003,44(29):5465-5468
Aromatic acetates were selectively deprotected in the presence of aliphatic acetates to the corresponding phenols in excellent yields using Amberlyst-15 or iodine as catalysts in methanol at room temperature. The first catalyst can be recovered. 相似文献
965.
Ramesh Paudel Gopi Chandra Kaphle Mohammed Batouche Jingchuan Zhu 《International journal of quantum chemistry》2020,120(24):e26417
The half-metallicity of Heusler alloys is quite sensitive to high pressure and disorder. To understand this phenomenon better, we systematically studied the half-metallic nature, magnetism, phonon, and thermomechanical properties of FeCrTe and FeCrSe Heusler alloys under high pressure using ab initio calculations based on density functional theory. The ground-state lattice constants for FeCrTe and FeCrSe alloys are 5.93 and 5.57 Å, respectively, consistent with available theoretical results. Formation energy, cohesive energy, elastic constants, and phonon dispersion confirmed that both compounds are thermodynamically and mechanically stable. The FeCrTe and FeCrSe alloys showed a half-metallic character with a band gap of 0.68 and 0.58 eV at 0 GPa pressure, respectively, and magnetic moments of 2.01 μB for both alloys, using generalized gradient approximation (GGA) approximation. FeCrTe alloy changes from metallic to half-metallic above 30 GPa pressure using GGA + U. The elastic properties were scrutinized, and it was found that, at 0 GPa pressure, FeCrTe is ductile, and FeCrSe is brittle. Under pressure, FeCrSe becomes brittle above 10 GPa pressure. Average sound velocity Vm, Debye temperature ƟD, and heat capacity CV were predicted under pressure. These outcomes will improve the integration of Fe-based half-Heusler alloys in spintronic devices. 相似文献
966.
Ramesh C. Kamboj Dinesh Kumar Surinder Berar Geeta Sharma Rita Arora 《Journal of heterocyclic chemistry》2014,51(4):948-953
The photo‐irradiation of chalconoid‐like compounds; (2E,4E)‐1‐(2‐hydroxyaryl)‐4‐methyl‐5‐phenylpenta‐2,4‐dien‐1‐ones to 4‐flavanoids in solution phase has been described. The molecular scaffold of the probed substrates is responsive to intramolecular cyclization as well as cis‐trans isomerizations and photoproducts corresponding to both of reactions have been realized also. The formation of photoproducts has been explained on the basis of excited state intramolecular proton transfer that further depends upon the different substituents present on the phenolic moiety. 相似文献
967.
Properties of Sizeable [n]Cycloparaphenylenes as Molecular Models of Single‐Wall Carbon Nanotubes Elucidated by Raman Spectroscopy: Structural and Electron‐Transfer Responses under Mechanical Stress 下载免费PDF全文
Miriam Peña Alvarez Paula Mayorga Burrezo Prof. Miklos Kertesz Dr. Takahiro Iwamoto Prof. Shigeru Yamago Jianlong Xia Prof. Ramesh Jasti Prof. Juan T. López Navarrete Prof. Mercedes Taravillo Prof. Valentín G. Baonza Prof. Juan Casado 《Angewandte Chemie (International ed. in English)》2014,53(27):7033-7037
[n]Cycloparaphenylenes behave as molecular templates of “perfectly chemically defined” single‐wall carbon nanotubes. These [n]CPP molecules have electronic, mechanical, and chemical properties in size correspondence with their giant congeners. Under mechanical stress, they form charge‐transfer salts, or complexes with fullerene, by one‐electron concave–convex electron transfer. 相似文献
968.
Investigating structural aspects to understand the putative/claimed non‐toxicity of the Hg‐based Ayurvedic drug Rasasindura using XAFS 下载免费PDF全文
Nitya Ramanan Debdutta Lahiri Parasmani Rajput Ramesh Chandra Varma A. Arun T. S. Muraleedharan K. K. Pandey Nandita Maiti S. N. Jha Surinder M. Sharma 《Journal of synchrotron radiation》2015,22(5):1233-1241
XANES‐ and EXAFS‐based analysis of the Ayurvedic Hg‐based nano‐drug Rasasindura has been performed to seek evidence of its non‐toxicity. Rasasindura is determined to be composed of single‐phase α‐HgS nanoparticles (size ~24 nm), free of Hg0 or organic molecules; its structure is determined to be robust (<3% defects). The non‐existence of Hg0 implies the absence of Hg‐based toxicity and establishes that chemical form, rather than content of heavy metals, is the correct parameter for evaluating the toxicity in these drugs. The stable α‐HgS form (strong Hg—S covalent bond and robust particle character) ensures the integrity of the drug during delivery and prevention of its reduction to Hg0 within the human body. Further, these comparative studies establish that structural parameters (size dispersion, coordination configuration) are better controlled in Rasasindura. This places the Ayurvedic synthesis method on par with contemporary techniques of nanoparticle synthesis. 相似文献
969.
The direct catalytic azidation of 2-hydroxy-1,2,2-triarylethanones occurs at room temperature using 2 mol % of InBr3 as Lewis acid and TMSN3 as soluble azide source. 2-Azido-1,2,2-triarylethanones have been isolated in excellent yields. The role of aryl group and stereoelectronic factors indicate that the mechanism may involve the formation of a stable carbenium ion towards azidation. 相似文献
970.
Three-component coupling reactions of aldehydes, amines, and cyclic enol ethers have been carried out in the presence of samarium triflate to afford the corresponding pyrano and furanoquinolines in excellent yields with high endo-selectivity. The reaction conditions are mild and amenable to scale-up. 相似文献