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排序方式: 共有213条查询结果,搜索用时 31 毫秒
91.
Singh RV Chaudhary P Poonia K Chauhan S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(3):587-594
Series of new trigonal bipyramidal and octahedral complexes of tin(IV) have been synthesized by the reaction of dimethyltin(IV) dichloride with 4-nitro-benzanilidethiosemicarbazone (L(1)H), 4-chlorobenzanilidethiosemicarbazone (L(2)H), 4-nitrobenzanilidesemicarbazone (L(3)H) and 4-chlorobenzanilidesemicarbazone (L(4)H). The unimolecular and bimolecular reactions of dimethyltin(IV) dichloride and monobasic bidentate ligands were carried out using microwave irradiations as the thermal energy source and the complexes so formed were characterized by elemental analysis, conductance measurements, molecular weight determinations and spectral data, viz. IR, UV-vis, (1)H and (13)C NMR. The complexes have also been prepared by the general thermal methods for comparison purposes. The comparison data support the synthesis using the microwave route, i.e. green chemistry route. The tin(IV) complexes show penta-coordinated structure for 1:1 complexes and hexa-coordinated for 1:2 complexes. The antifungal, antibacterial and antifertility activities have been examined and the results were indeed very encouraging. 相似文献
92.
Various oxomolybdenum complexes are efficient and selective homogeneous catalysts in the presence of organic hydroperoxides. The increasing interest in the heterogenisation of such catalysts has led to an increased interest in finding suitable support materials for the complexes. These supports include ionic liquids, mesoporous materials and zeolites to name a few. Several methods are used to anchor the catalyst depending on the nature of the carrier material. The supported catalysts combine properties of homogeneous catalysts such as reactivity, control and selectivity with those of heterogeneous catalysts such as enhanced stability and recyclability. 相似文献
93.
Gacche R Khsirsagar M Kamble S Bandgar B Dhole N Shisode K Chaudhari A 《Chemical & pharmaceutical bulletin》2008,56(7):897-901
Synthetic derivatives of 1-(2-hydroxy-3-(2-hydroxy-cyclohexyl)-4,6-dimethoxy-phenyl)-methanone were evaluated in-vitro for their activities related to antioxidant and anti-inflammatory. The antioxidant potential was determined by calculating reducing potential, OH and DPPH (2,2-diphenyl-1-picryl hydrazine) radical scavenging activities. The in-vitro anti-inflammatory related activities of synthetic chalcones (SCs) were demonstrated by performing inhibition assays of trypsin, beta-glucuronidase and diene conjugates. The results of the various parameters studied shows that the selected derivatives were found to be effective reducing agents and were reactive towards stabilizing the OH and DPPH radicals. The compounds have showed moderate to poor or no inhibition profile towards trypsin and beta-glucuronidase, but were found to be effective inhibitor of dien conjugates (hydroperoxides). An attempt has been made to define structure activity relationship using BioMed CAChe 6.1.10: a computer-aided molecular modeling tool which applies equations from classical and quantum mechanics. The experimental and in silico results of the present investigation shows that the basic nucleus 1-(2-hydroxy-3-(2-hydroxy-cyclohexyl)-4,6-dimethoxy-phenyl)-methanone can be considered as a potential candidate for the design and development of lead antioxidant and anti-inflammatory agents. 相似文献
94.
95.
Tiwari Aditya Narayan Tapadia Kavita Thakur Chandrakant Sharma Ashima 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(9):3819-3833
Journal of Radioanalytical and Nuclear Chemistry - Magnetically modified nanoparticles have been demonstrated to be quite successful at re-mediating wastewater in recent experiments. The current... 相似文献
96.
Himatkumar V. Patel Kavita A. Vyas Sudhanshu P. Pandey Francis Tavares P. S. Fernandes 《合成通讯》2013,43(18-19):1935-1940
A one-pot synthesis of 5,6-disubstituted-2-phenyl-3(2H)-pyridazinones 4 is achieved on treatment of carbanion of ethyl trimethlsiylacetate with phenylhydrazones of 1,2-dicarbonyl compounds 1. 相似文献
97.
Gauhar Abbas B. Ananthanarayan I. Caprini I. Sentitemsu Imsong S. Ramanan 《The European Physical Journal A - Hadrons and Nuclei》2010,45(3):389-399
We present a general formalism for deriving bounds on the shape parameters of the weak and electromagnetic form factors using
as input correlators calculated from perturbative QCD, and exploiting analyticity and unitarity. The values resulting from
the symmetries of QCD at low energies or from lattice calculations at special points inside the analyticity domain can be
included in an exact way. We write down the general solution of the corresponding Meiman problem for an arbitrary number of
interior constraints and the integral equations that allow one to include the phase of the form factor along a part of the
unitarity cut. A formalism that includes the phase and some information on the modulus along a part of the cut is also given.
For illustration we present constraints on the slope and curvature of the Kl3 scalar form factor and discuss our findings in some detail. The techniques are useful for checking the consistency of various
inputs and for controlling the parameterizations of the form factors entering precision predictions in flavor physics. 相似文献
98.
The direct substrates of one protein kinase in a cell can be identified by mutation of the ATP binding pocket to allow an unnatural ATP analog to be accepted exclusively by the engineered kinase. Here, we present structural and functional assessment of peptide specificity of mutant protein kinases with unnatural ATP analogs. The crystal structure (2.8 A resolution) of c-Src (T338G) with N(6)-(benzyl) ADP bound shows that the creation of a unique nucleotide binding pocket does not alter the phospho-acceptor binding site of the kinase. A panel of optimal peptide substrates of defined sequence, as well as a degenerate peptide library, was utilized to assess the phospho-acceptor specificity of the engineered "traceable" kinases. The specificity profiles for the mutant kinases were found to be identical to those of their wild-type counterparts. 相似文献
99.
A simple, rapid, straightforward and washing/separation free of in-solution digestion method for microwave-assisted tryptic digestion of proteins (cytochrome c, lysozyme and myoglobin) using bare TiO(2) nanoparticles (NPs) prepared in aqueous solution to serve as multifunctional nanoprobes in electrospray ionization mass spectrometry (ESI-MS) was demonstrated. The current approach is termed as 'on particle ionization/enrichment (OPIE)' and it can be applied in ESI-MS, atmospheric pressure-matrix-assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The bare TiO(2) NPs can assist, accelerate and effectively enhance the digestion efficiency, sequence coverage and detection sensitivity of peptides for the microwave-assisted tryptic digestion of proteins in ESI-MS. The reason is attributed to the fact that proteins or partially digested proteins are easily attracted or concentrated onto the surface of TiO(2) NPs, resulting in higher efficiency of digestion reactions in the microwave experiments. Besides, the TiO(2) NPs could act as a microwave absorber to accelerate and enrich the protein fragments in a short period of time (40-60 s) from the microwave experiments in ESI-MS. Furthermore, the bare TiO(2) NPs prepared in aqueous solution exhibit high adsorption capability toward the protein fragments (peptides); thus, the OPIE approach for detecting the digested protein fragments via ESI and MALDI ionization could be achieved. The current technique is also a washing and separation-free technique for accelerating and enriching microwave-assisted tryptic digestion of proteins in the ESI-MS and MALDI-MS. It exhibits potential to be widely applied to biotechnology and proteome research in the near future. 相似文献
100.
Joseph J. Pesek Maria T. Matyska Kavita V. Prajapati 《Journal of separation science》2010,33(19):2908-2916
Two novel silica hydride‐based fluorinated bonded phases have been synthesized using a hydrosilation procedure to test combined fluorine and hydride selectivity. The bonded moieties were characterized by elemental and spectral analysis. Chromatographic testing was done using hydrophilic analytes in the aqueous normal phase mode. At higher amounts of the nonpolar solvent in the mobile phase, there should be increased retention for solutes such as acids, bases and other polar compounds, whereas nonpolar solutes can be retained when water is increased as in RP chromatography. The synergistic effects of the fluorinated phase selectivity and aqueous normal phase retention on a hydride surface have been explored for small polar molecules. The stability and repeatability of the hydride‐based fluorinated stationary phases were evaluated. The use of acetone as the organic component in the mobile phase was also tested. 相似文献