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151.
An indigenous electron energy loss spectrometer has been designed and fabricated for the study of free molecules. The spectrometer
enables the recording of low-resolution electronic spectra of molecules in the vapour phase with ready access to the vacuum
ultraviolet region. Electron energy loss spectra of aliphatic alcohols and carbonyl compounds as well as of benzene derivatives
have been recorded with the indigenous spectrometer and the electronic transitions in these molecules discussed.
Contribution No. 274 from the Solid State and Structural Chemistry Unit, dedicated to Dr. Raja Ramanna on his 60th birthday. 相似文献
152.
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154.
The methylation of propene and toluene with dimethyl ether has been studied using both experimental and theoretical methods, and the results are compared with results obtained for methylation with methanol. The results indicate that the nature of the methylation reaction mechanisms is very similar for both methylation agents. Both experiment and theory show that dimethyl ether is a slightly more reactive methylating agent than methanol. 相似文献
155.
Patel RN Singh N Shukla KK Niclós-Gutiérrez J Castineiras A Vaidyanathan VG Nair BU 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,62(1-3):261-268
Two new mixed ligand copper(II) complexes with diethylenetriamine, 2,2'-bipyridine and 1,10-phenanthroline have been synthesized. The crystal and molecular structures of [Cu(dien)(phen)](ClO(4))(2) and [Cu(dien)(bipy)](BF(4))(2) (dien=diethylenetriamine, phen=1,10-phenanthroline, bipy=2,2'-bipyridine) were determined by X-ray crystallography from single crystal data. These two complexes have similar structures. The EPR spectral data also suggest that these complexes have distorted square pyramidal geometry about copper(II). Anti-microbial and superoxide dismutase activities of these complexes have also been measured. They show the higher SOD activity than the corresponding simple Cu(II)-dien/Cu(II)-PMDT (PMDT=N,N,N',N',N'-pentamethyldiethylenetriamine) complexes because of a strong axial bond of one of the nitrogen atoms of the alpha-diimine. Both the complexes have been found to cleave plasmid DNA in the presence of co-reductants such as ascorbic acid and glutathione. 相似文献
156.
Srinivasan Radhika Mookandi Kanthimathi Ramakrishnan Parthasarathi Balachandran Unni Nair 《Transition Metal Chemistry》2007,32(3):362-366
A new europium complex containing the chelate tridentate ligand and imidazole terpyridine (itpy), was synthesized. The complex
was characterized by elemental analysis, mass, FT-IR and photoluminescence spectroscopic techniques. The europium complex
in solution showed characteristic luminescence properties. The room temperature photoluminescence spectrum of this complex
was composed of typical Eu3+ red emission assigned to 5D0 → 7F2 transition. The metal-centered red emission seemed to be promoted by the ligand-assisted energy transfer, namely antenna
effect. 相似文献
157.
Two mixed ligand complexes of ruthenium(ii) [Ru(bzimpy)(bpy)(OH(2))](2+) (1) and [Ru(bzimpy)(phen)(OH(2))](2+) (2) have been synthesized and characterized by FAB mass, (1)H NMR, cyclic voltammetry and spectroelectrochemical measurements. Controlled potential electrolysis of these complexes results in the conversion of ruthenium(ii) to ruthenium(iii) at 0.6 V and ruthenium(iii) to ruthenium(iv) at 0.8 V vs. SCE. The binding constant of these complexes with DNA has been determined electrochemically and found to be (3.58 +/- 0.25) x 10(4) and (2.87+/- 0.2) x 10(4) M(-1). Viscosity measurements suggest that these complexes bind with DNA through intercalation. Such intercalative binding to DNA has been found to induce chirality to the two complexes. Electrochemically generated ruthenium(iv) species of these complexes have been found to bring about oxidative cleavage in DNA. 相似文献
158.
Unni AK Takenaka N Yamamoto H Rawal VH 《Journal of the American Chemical Society》2005,127(5):1336-1337
Axially chiral 1,1'-biaryl-2,2'-dimethanol (3, BAMOL) family of diols are highly effective catalysts for enantioselective hetero-Diels-Alder reactions between aminosiloxydiene 1 and a wide variety of unactivated aldehydes. The reactions proceed in useful yields and excellent enantioselectivities. The diols function in the same capacity as Lewis acids, by activating the aldehyde carbonyl group through hydrogen bonding. 相似文献
159.
Srinivasan J Cload ST Hamaguchi N Kurz J Keene S Kurz M Boomer RM Blanchard J Epstein D Wilson C Diener JL 《Chemistry & biology》2004,11(4):499-508
Two molecular sensors that specifically recognize ADP in a background of over 100-fold molar excess of ATP are described. These sensors are nucleic-acid based and comprise a general method for monitoring protein kinase activity. The ADP-aptamer scintillation proximity assay is configured in a single-step, homogeneous format while the allosteric ribozyme (RiboReporter) sensor generates a fluorescent signal upon ADP-dependent ribozyme self-cleavage. Both systems perform well when configured for high-throughput screening and have been used to rediscover a known protein kinase inhibitor in a high-throughput screening format. 相似文献
160.
Solomon Legese Hailu Balachandran Unni Nair Mesfin Redi-Abshiro Isabel Diaz Rathinam Aravindhan Merid Tessema 《催化学报》2016,(1):135-145
将Fe(Ⅲ),Ni(Ⅲ)和Cu(Ⅱ)与N,N'-双邻羟苯亚甲基-1,2-苯二胺配位的络合物封装在Y分子筛内,作为多相类Fenton的高级氧化过程的催化剂,用于降解4-氯-3-甲基苯酚(PCMC).采用粉末X射线衍射、热重、N2吸附-脱附、红外光谱、元素分析和扫描电镜对所制催化剂的物化性质进行了表征,并考察了H2O2的初始浓度、催化剂用量、温度和pH值等因素对模型有机污染物降解的影响.结果表明,在Fe(Ⅲ),Ni(Ⅲ)和Cu(Ⅱ)催化剂作用下,在较低的酸性pH值、催化剂用量0.1 g、H2O2的初始浓度0.35 mmol/L的条件下,于50℃反应120 min几乎可以完全去除PCMC.同时还考察了所制PCMC降解催化剂的重复使用性能,提出了可能的催化剂失活机理,也研究了PCMC氧化过程中可能的中间产物和动力学. 相似文献