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11.
U. Pandey S. Banerjee A. Mukherjee H. D. Sarma M. Venkatesh 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(3):719-723
Several human tumors such as neuroendocrine tumors, medullary thyroid carcinoma, etc., express somatostatin receptors which
specifically bind somatostatin and its analogues such as lanreotide, octreotide, etc. In order to prepare a therapeutic agent
for targeting such tumors, attempts were made to prepare 90Y-DOTA-Lanreotide. Lanreotide could be successfully conjugated with the macrocyclic chelating agent DOTA (1,4,7,10-tetraaza
cyclododecane tetracetic acid) which forms stable complexes with 90Y. 90Y-DOTA-Lanreotide could be prepared in >98% radiochemical purity and remained stable for 72 hours at room temperature. The
tracer showed specific binding to A431 cells. Biodistribution studies in C57BL6 mice bearing melanoma showed ∼1.3% uptake
pergram of tumor at 24-hour p.i. 相似文献
12.
The possibility of excited‐state protomeric shifts in the biologically important molecule, alloxan, is investigated. We have focused on the S1 and T1 excited states of alloxan and its hydroxy tautomers. Modifications brought in by excitation on the relative stabilities, activation barriers, and optimized geometries, computed at the MNDO, AM1, and PM3 levels of approximation, have been discussed for both excited electronic states. The absorption and fluorescence spectra for the three tautomers are also discussed. Results show significant changes in the geometries on excitation, although the changes are similar for the singlet and triplet excited states. Though the relative stability orders do not change, the 2‐hydroxy tautomer is stabilized, while the 4‐hydroxy tautomer gets destabilized on excitation. The excited states are (n,π*) states, involving the promotion of a nonbonding oxygen lone pair from the CO? CO? CO moiety, which explains why the oxygens of this group become less basic and the 4‐hydroxy tautomer gets destabilized on excitation. However, the activation barriers do not reduce significantly on excitation, and this precludes the possibility of ground‐ or excited‐state proton transfer in the gas phase. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001 相似文献
13.
The optimum conditions for the titration of antimony(III) with dichromate, and diphenyl-aminesulphonic acid as indicator, have been established. No iodine catalyst is used; the analytical reaction is based on an induced reaction with iron(II) as inductor. The titration can be done as easily as an iron(II) titration and the end-point is equally sharp. Titrations are possible with 0.01N solutions. 相似文献
14.
15.
Saurav Ch Sarma Jesús Barrio Alexander Bagger Angus Pedersen Mengjun Gong Hui Luo Mengnan Wang Silvia Favero Chang-Xin Zhao Qiang Zhang Anthony Kucernak Maria-Magdalena Titirici Ifan E. L. Stephens 《Advanced functional materials》2023,33(41):2302468
The electrochemical CO2 reduction reaction (CO2RR) to value-added chemicals with renewable electricity is a promising method to decarbonize parts of the chemical industry. Recently, single metal atoms in nitrogen-doped carbon (MNC) have emerged as potential electrocatalysts for CO2RR to CO with high activity and faradaic efficiency, although the reaction limitation for CO2RR to CO is unclear. To understand the comparison of intrinsic activity of different MNCs, two catalysts are synthesized through a decoupled two-step synthesis approach of high temperature pyrolysis and low temperature metalation (Fe or Ni). The highly meso-porous structure results in the highest reported electrochemical active site utilization based on in situ nitrite stripping; up to 59±6% for NiNC. Ex situ X-ray absorption spectroscopy (XAS) confirms the penta-coordinated nature of the active sites. The catalysts are amongst the most active in the literature for CO2 reduction to CO. The density functional theory calculations (DFT) show that their binding to the reaction intermediates approximates to that of Au surfaces. However, it is found that the turnover frequencies (TOFs) of the most active catalysts for CO evolution converge, suggesting a fundamental ceiling to the catalytic rates. 相似文献
16.
17.
Summary The mixed ligand complex, [Fe(Phen)2(N3)2] can be extracted into nitrobenzene giving a molar absorptivity of 16750 at 510 nm. This is the basis of a photometric method for iron which may be either in the trivalent or bivalent state. The new method is free from interference from a number of substances and is more sensitive than the ferroin method.
Zusammenfassung Der Eisen-Phenanthrolin-Azid-Mischkomplex [Fe(Phen)2(N3)2] ist mit Nitrobenzol extrahierbar und gibt bei 510 nm eine molare Absorption von 16750. Darauf läßt sich eine photometrische Bestimmungsmethode für zweioder dreiwertiges Eisen begründen. Diese wird von vielen Stoffen nicht gestört und ist empfindlicher als die Ferroinmethode.相似文献
18.
T. Suryanarayana Murthy D. V. N. Sarma 《Fresenius' Journal of Analytical Chemistry》1958,161(2):114-115
Summary A method for separation of thorium from rare earths in monazite based on the difference of stability of EDTA complexes towards oxine is described. 相似文献
19.
Sumit Bhaduri Krishna R. Sarma Bikshandarkovil A. Narayan 《Transition Metal Chemistry》1981,6(4):206-210
Summary Four-coordinate nickel nitrosyl complexes of the general formula Ni(NO)X(Dppe) (Dppe=Ph2PCH2CH2PPh2) have been prepared byin situ formation of Ni(NO2)X(Dppe), (X= Cl, Br, I or SCN) followed by reduction with triphenylphosphine, or carbon monoxide, and/or DMF. Oxygenation of the nitrosyl complexes gives the corresponding nitro products and as indicated by u.v.-vis spectroscopy involves formation of an intermediate. The oxygenation rate increases markedly in the presence of light or of a catalytic amount of benzoyl peroxide and a tentative explanation is offered for these observations. Ionic adducts are formed in reactions between the nitrosyl complexes and donor molecules.Paper presented in part at the XXth ICCC Conference. 相似文献
20.
Dutta D Sarma TK Chowdhury D Chattopadhyay A 《Journal of colloid and interface science》2005,283(1):153-159
In this paper we report a new idea for synthesizing polyaniline in an ordinary filter paper. The synthesis was carried out by a process in which aqueous acidic aniline solution and the oxidizing agent H(2)O(2) was added to the paper drop by drop and in sequence. Uniform polymerization could be obtained with the addition of reagents in either sequence. The polymer formation led to a green coloration of the paper. Formation of the emeraldine salt of polyaniline was confirmed by UV-vis and FTIR spectroscopy. Scanning electron microscopic measurements were made for surface characterization of the polymer formed in the paper. The same paper was used as a sensor for ammonia in vapor and in solution, for acid and base as well as endpoint indication, and also to filter acids and bases. We found that, using the polymer-containing paper, ammonia concentrations in a solution as low as 14 ppm could be measured. 相似文献