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201.
Rati Ranjan Nayak Nilotpala Pradhan Debadhyan Behera Kshyama Madhusikta Pradhan Srabani Mishra Lala Behari Sukla Barada Kanta Mishra 《Journal of nanoparticle research》2011,13(8):3129-3137
An eco-friendly microbial method for synthesis of silver colloid solution with antimicrobial activity is developed using a
fungal strain of Penicillium purpurogenum NPMF. It is observed that increase in concentration of AgNO3 increases the formation of silver nanoparticle. At 5 mM concentration highly populated polydispersed nanoparticles form.
Furthermore, change in pH of the reaction mixture leads to change in shape and size of silver nanoparticles. At lower pH two
peaks are observed in the absorption spectra showing polydispersity of nanoparticles. However, highly monodispersed spherical
nanoparticles of 8–10 nm size form with 1 mM AgNO3 concentration at pH 8. Antimicrobial activity of nanoparticles is demonstrated against pathogenic gram negative bacteria
like Escherichia coli and Pseudomonas aeruginosa, and gram positive bacteria like Staphylococcus aureus. The antimicrobial activity of silver nanoparticles obtained at different initial pH show strong dependence on the surface
area and shape of the nanoparticles. 相似文献
202.
The aqueous polymerization of methyl methacrylate initiated by the redox system K2S2O8-ascorbic acid has been studied at 35°C under the influence of oxygen. The rate of polymerization increases with increasing ascorbic acid concentration at low activator concentration, remains constant within the range 4.375 × 10?3 to 11.25 × 10?3 mole/liter, and at higher ascorbic acid concentration again decreases. The rate varies linearly with monomer concentration. The initial rate and the limiting conversion increase with increasing polymerization temperature. Organic solvents (water-miscible only) and small amounts of neutral salts like KC1 and Na2SO4 depress the initial rate and the maximum conversion. The addition of small amounts of salts like Cu2+ and Mn2+ increases the initial rate, but no appreciable increase in the limiting conversion is observed. 相似文献
203.
Abstract 4-Acetyl-phenyl acrylate was prepared by reacting 4-hydroxy acetophenone with acryloyl chloride. It was then polymerized using benzoyl peroxide (BPO) as initiator to give the homopolymer. Both the vinylmonomer and its homopolymer were characterized by FTIR spectra. The polyurethane obtained from castor oil and TDI (Toluene-2,4-diisocyanate) with varying NCO/OH ratio was reacted with the new monomer 4-acetyl phenyl acrylate to give a large number of interpenetrating polymer networks (IPNs) using divinyl benzene as cross-linker and BPO as initiator. The thermogravimetric studies of the IPNs have been carried out and the kinetic parameters have been evaluated. 相似文献
204.
Bhattacharya S Chattopadhyay S Nayak SK Banerjee M 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,62(1-3):729-735
Supramolecular complexation of [60]- and [70]fullerenes with 37-allyl-38,39,40,41,42-pentahydroxy-5,11,17,23,29,35-hexa(4-tert butyl)calix[6]arene (I) has been studied in CCl(4) medium by NMR spectrometric method. All of the complexes are found to be stable with 1:1 stoichiometry. Formation constants (K) of the above supramolecular complexes have been determined from systematic variation of NMR chemical shifts of specific protons of I in the presence of [60]- and [70]fullerenes. Trends in the K value suggest that [70]fullerene binds more strongly with I relative to [60]fullerene. Both PM3 and ab initio calculations reveal that the intermolecular interaction in the [70]fullerene/I complex proceeds through quite deep energy minima. 相似文献
205.
Thanh N. Truong Tom Cook Manohar Nayak Chaiwoot Boonyasiriwat Le-Thuy T. Tran Shaowen Zhang 《Molecular physics》2013,111(4):353-360
We present a development of an integrated extendable web-based environment called Computational Science and Engineering On-line (CSEO) to include different fields of computational science. Our initial efforts are focusing on an integrated environment for multi-scale modelling of complex reacting systems from fundamental quantum chemistry with different entry points. CSEO provides an information management system that allows data flow from one application to another in a transparent manner. In addition, it provides a set of web-based graphic-user interfaces (GUIs) to different scientific applications. Current available GUIs are for quantum chemistry, thermodynamics and kinetics. Work is in progress to allow CSEO accessing resources from the computing grids using the Globus technology. CSEO can be accessed at http://cseo.net. It can also be hosted at different mirror sites. 相似文献
206.
207.
A. Sreenath Reddy Jincheng Mao S. Vanitha Vishnu Nayak Badavath L. Sivarama Krishna M. Lavanya M.V. Jyothi kumar 《Journal of Saudi Chemical Society》2019,23(7):947-957
Two slightly distorted octahedral complexes of copper(II) with (E)-2-((E)-3-(3,4,5-trimethoxyphenyl)allylidene)hydrazinecarbothioamide (L1) common name 3,4,5-trimethoxy-cinnamaldehydethiosemicarbazone and (E)-N-phenyl-2-((E)-3-(3,4,5-trimethoxyphenyl)-allylidene)hydrazinecarbothioamide (L2) common name 3,4,5-trimethoxycinnamaldehyde-4-phenylthiosemicarbazone have been synthesized. The two free ligands and their copper(II) complexes were characterized by spectroscopic techniques like FT-IR, FT-Raman, UV, EPR, Powder X-ray diffraction and cyclic voltammetry. The EPR spectra evidenced a rhombically distorted octahedron geometry for both the copper(II) complexes. The band gap calculations for the ligands L1, L2 and their complexes Cu(L1)2Cl2 and Cu(L2)2Cl2 were found to be 2.98, 2.61, 2.66 and 2.50 eV respectively. Cu(L1)2Cl2 and Cu(L2)2Cl2 have shown 50% of viability at 80 μg/ml and 60 μg/ml. The anti-oxidant activity study revealed that the compounds are good reductants of DPPH radical. Moderate to good anti-bacterial activity is shown by the compounds against the Gram-positive and Gram-negative bacteria. Molecular docking studies have been carried out to predict the orientation and binding mode of analysis in the active site. The synthesized ligand and complex well occupy (catalytic triad and adenine-binding site) in the active site of β-ketoacyl-acyl carrier protein synthase III enzyme, and also well occupy in helix 11 (in the DCS complex) of human estrogen receptor. Moreover they form water mediated hydrogen bond and hydrogen bond with Cys530 residue. 相似文献
208.
Ashok Kumar R. K. Jain Praveen Yadav R. N. Chakraborty B. K. Singh B. K. Nayak 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):95-98
It is observed that for Lexan and Makrofol-DE polycarbonate plastic detectors the mean diameters of fission fragments from a 252Cf source increases as a result of gamma-ray exposure. We have studied the bulk etching rate and track etching rate before and after gamma-ray irradiation on Lexan and Makrofol-DE polycarbonate plastics. The mechanism of Lexan and Makrofol-DE polycarbonate plastic detectors can be understood with the help of this exposures. It is also noted that degree of ordering of Lexan and Makrofol-DE polycarbonate is dependent on the gamma ray dose due to degradation and cross-linking processes. The results show that bulk and track etch rate increases with gamma dose while activation energy associated with bulk and track etch rates at a particular temperature and sensitivity decreases with gamma dose. 相似文献
209.
The graft copolymerization of methyl methacrylate onto wool fibers was investigated in aqueous solution using the acetylacetonato complex of manganese(III). The rate of grafting was determined by varying the monomer, the complex, the temperature, the acidity of the medium, the nature of the wool, and the reaction medium. The graft yield increases with increasing monomer and complex concentrations. The graft yield also increases with increasing temperature. The grafting is considerably influenced by chemical modification of wool prior to grafting. A suitable mechanism has been proposed and a rate equation has been derived. 相似文献
210.
The synthesis
of conducting polymers based on m-nitroaniline, m-chloroaniline and m-aminophenol
by aniline initiated ammonium peroxydisulfate oxidation, has been attempted.
The IR spectra of the polymers have been studied. Thermogravimetric analysis
of the conducting polymers has been followed using a computer analysis method
LOTUS PACKAGE, developed by us for assigning the degradation mechanism. A
number of equations have been used to evaluate the kinetic parameters. The
mechanism of degradation of the conducting polymers has been explained on
the basis of their kinetic parameters. 相似文献