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排序方式: 共有331条查询结果,搜索用时 31 毫秒
61.
Kumar M Kumar R Bhalla V Sharma PR Kaur T Qurishi Y 《Dalton transactions (Cambridge, England : 2003)》2012,41(2):408-412
A thiacalix[4]arene based fluorescent chemosensor 3 in the cone conformation has been synthesized and its recognition behaviour is evaluated toward various metal ions in mixed aqueous media. The chemosensor 3 showed high selectivity towards Fe(3+) ions by fluorescence quenching of excimer emission. Further, evaluation of the 3·Fe(3+) complex prepared in situ demonstrated great promise for the detection of the Fe(3+) ion in the presence of amino acids, blood serum and bovine serum albumin (BSA) solution. The compound 3 has suitable permeability into the PC3 cells and can be utilized as a Fe(3+) selective sensor in living cells (PC3 cells). 相似文献
62.
Yogesh NangiaVijayender Bhalla Bipul KumarC. Raman Suri 《Electrochemistry communications》2012,14(1):51-54
The paper reports a highly sensitive enzyme free electrochemical immunoassay (EFEIA) for the detection of herbicide chlorsulfuron. The assay is based upon oxidative gold nanoparticle (GNP) dissolution in an acidic solution. The consequent release of large amounts of gold (Au) metal ions after dissolution of gold nanoparticles tagged to antibody leads to the development of sensitive stripping voltammetry based immunoassay. The detection is made possible by the reduction of Au3 + ions at the screen printed electrode surface followed by metal analysis by using the square wave voltammetry technique. The sensitivity of chlorsulfuron detection by competitive assay procedure was 6.7 pg mL− 1 for EFEIA in marked contrast to optical detection using Standard ELISA procedure that gives a sensitivity of 4.97 ng mL− 1. 相似文献
63.
Gourab Chatterjee Ajay Jha Alejandro Blanco-Gonzalez Vandana Tiwari Madushanka Manathunga Hong-Guang Duan Friedjof Tellkamp Valentyn I. Prokhorenko Nicolas Ferr Jyotishman Dasgupta Massimo Olivucci R. J. Dwayne Miller 《Chemical science》2022,13(32):9392
The concerted interplay between reactive nuclear and electronic motions in molecules actuates chemistry. Here, we demonstrate that out-of-plane torsional deformation and vibrational excitation of stretching motions in the electronic ground state modulate the charge-density distribution in a donor-bridge-acceptor molecule in solution. The vibrationally-induced change, visualised by transient absorption spectroscopy with a mid-infrared pump and a visible probe, is mechanistically resolved by ab initio molecular dynamics simulations. Mapping the potential energy landscape attributes the observed charge-coupled coherent nuclear motions to the population of the initial segment of a double-bond isomerization channel, also seen in biological molecules. Our results illustrate the pivotal role of pre-twisted molecular geometries in enhancing the transfer of vibrational energy to specific molecular modes, prior to thermal redistribution. This motivates the search for synthetic strategies towards achieving potentially new infrared-mediated chemistry.Channelling vibrational excitation energy to achieve ground-state charge-transfer (CT)-assisted isomerization in a donor-bridge-acceptor molecule in solution. 相似文献
64.
Photosensitizing assemblies of pyrazine derivative PDA have been developed which exhibit a high photostability, ‘lighted’ excited state, balanced redox potential, high transportation potential and activate oxygen via type-I pathway only. These PDA assemblies in combination with Cu(II) ions catalyze the CuAAC reaction via in situ reduction of Cu(II) ions without any reducing or stabilizing agent. The present protocol has wide substrate scope with recyclability of the catalytic system up to six catalytic cycles and is applicable to gram-scale synthesis. 相似文献
65.
The intermittency effect has been observed in interactions of 800 GeV protons with emulsion-nuclei in one-(pseudorapidity/azimuthal angle) and two-dimensional (pseudorapidity and azimuthal angle) phase spaces in different multiplicity intervals. The intermittency strength is found to decrease with increasing multiplicity. Compared to one dimension, the two dimensional distribution is found to reflect better the intermittent behavior of the interactions. The dependence of various intermittency parameters on order of moment gives clear evidence of self-similar cascade mechanism in the interactions but there is no definite indication of the presence of different phases in the cascade. 相似文献
66.
H. L. Bhalla R. Mathew Grace Samuel N. Sivaprasad 《Journal of Radioanalytical and Nuclear Chemistry》1997,221(1-2):93-95
The preparation of stable and immunoreactive radioiodinated clonidine for the development of a radioimmunoassay of clonidine is described. Tyrosylmethyl ester (TME) conjugate of carboxylic acid derivative of clonidine was radioiodinated using chloramine T as the oxidizing agent. The radioiodinated clonidine was purified by thin layer chromatography, gel filtration and solvent extraction. Radiochemical purity, specific activity and immunoreactivity were determined. The stability of the labeled compound during storage was tested in various solvents at different temperatures. 相似文献
67.
Adamovich MI Aggarwal MM Alexandrov YA Andreeva NP Anzon ZV Arora R Avetyan FA Badyal SK Bhalla KB Bhasin A Bhatia VS Bogdanov VG Bubnov VI Burnett TH Cai X Chasnikov IY Chernova LP Chernyavsky MM Eligbaeva GZ Eremenko LE Gaitinov AS Ganssauge ER Garpman S Gerassimov SG Grote J Gulamov KG Gupta SK Gupta VK Heckman HH Huang H Jakobsson B Judek B Just L Kachroo S Kalyachkina GS Kanygina EK Karabova M Kaul GL Kitroo S Kharlamov SP Krasnov SA Kulikova S Kumar V Lal P Larionova VG Lepetan VN Liu LS 《Physical review letters》1992,69(5):745-748
68.
69.
The large discrepancies between the calculated and observed structures for BrF(4)(+) and IF(4)(+) (Christe, K. O.; Zhang, X.; Sheehy, J. A.; Bau, R. J. Am. Chem. Soc. 2001, 123, 6338) prompted a redetermination of the crystal structures of BrF(4)(+)Sb(2)F(11)(-) (monoclinic, P2(1)/c, a = 5.2289(6) A, b = 14.510(2) A, c = 14.194(2) A, beta = 90.280(1) degrees, Z = 4) and IF(4)(+)SbF(6)(-) (orthorhombic, Ibca, a = 8.2702(9) A, b = 8.3115(9) A, c = 20.607(2) A, Z = 8). It is shown that for BrF(4)(+), the large differences were mainly due to large errors in the original experimental data. For IF(4)(+)SbF(6)(-), the geometry previously reported for IF(4)(+) was reasonably close to that found in this study despite a very large R-factor of 0.15 and a refinement in an incorrect space group. The general agreement between the calculated and the redetermined geometries of BrF(4)(+) and IF(4)(+) is excellent, except for the preferential compression of one bond angle in each ion due to the influence of interionic fluorine bridges. In BrF(4)(+), the fluorine bridges are equatorial and compress this angle. In IF(4)(+), the nature of the fluorine bridges depends on the counterion, and either the axial (in IF(4)(+)SbF(6)(-)) or the equatorial (in IF(4)(+)Sb(2)F(11)(-)) bond angle is preferentially compressed. Therefore, the geometries of the free ions are best described by the theoretical calculations. 相似文献
70.
Tenn WJ Young KJ Bhalla G Oxgaard J Goddard WA Periana RA 《Journal of the American Chemical Society》2005,127(41):14172-14173
A thermally and air stable O-donor, iridium-methoxo complex is reported that undergoes stoichiometric, intermolecular C-H activation of benzene with co-generation of methanol and the iridium-phenyl complex. 相似文献