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861.
H. Enginar P. Unak F. Z. Biber Müftüler F. Y. Lambrecht A. Yurt Kilcar S. Yolcular B. Seyitoğlu E. I. Medine I. Bulduk 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):667-673
In current study, ethyl-morphine (em) was synthesized from the morphine and glucuronidated via enzymatic mechanism. The conjugated
glucuronide ethyl-morphine (em-glu) was radiolabeled with 131I using iodogen method. The quality control studies of radiolabeled compound (131I-em-glu) were done with Thin Layer Radio Chromatography to confirm the radiolabeling efficiency. Biodistribution studies
of 131I labeled em-glu were run on healthy male Albino Wistar rats. The distribution figures demonstrated that 131I-em-glu was eliminated through the small intestine, large intestine and accumulated in urinary bladder both receptor blocked
and unblocked biodistribution studies. A greater uptake of the radiolabeled substance was observed in the m.pons, hypothalamus
and mid brain than in the other branches of the rats’ brains. 相似文献
862.
Arijit Jana Chiranjit Maity Suman Kumar Halder Keshab Chandra Mondal Bikash Ranjan Pati Pradeep Kumar Das Mohapatra 《Applied biochemistry and biotechnology》2012,167(5):1254-1269
Tannase production by newly isolated Penicillium purpurogenum PAF6 was investigated by ??one variable at a time?? (OVAT) approach followed by response surface methodology (RSM). Tannin-rich plant residues were used as supporting solid substrate and sole carbon source and, among them, tamarind seed was found to be the most favorable substrate than haritaki, pomegranate, tea leaf waste and arjun fruit. Physicochemical parameters were initially optimized using OVAT methodology and some important factors like incubation time, incubation temperature, substrate:moisture ratio as well as carbon, nitrogen and phosphate concentrations were verified with Box?CBehken design of response surface methodology. Phosphate source, nitrogen source and temperature were found as the most favorable variables in the maximization of production. Tannase production was enhanced from 1.536 U/g to 5.784 U/g using tamarind seed OVAT optimization and further enhancement up to 6.15 U/g following RSM. An overall 3.76- and 4.0-fold increases in tannase production were achieved in OVAT and RSM, respectively. 相似文献
863.
Huang S Pfeiffer C Hollmann J Friede S Chen JJ Beyer A Haas B Volz K Heimbrodt W Montenegro Martos JM Chang W Parak WJ 《Langmuir : the ACS journal of surfaces and colloids》2012,28(24):8915-8919
Ultrasmall water-soluble silver nanoclusters are synthesized, and their properties are investigated. The silver nanoclusters have high colloidal stability and show fluorescence in the red. This demonstrates that like gold nanoclusters also silver nanoclusters can be fluorescent. 相似文献
864.
Beltrán-Osuna ÁA Cao B Cheng G Jana SC Espe MP Lama B 《Langmuir : the ACS journal of surfaces and colloids》2012,28(25):9700-9706
In this work, a new antifouling silica hydrogel was developed for potential biomedical applications. A zwitterionic polymer, poly(carboxybetaine methacrylate) (pCBMA), was produced via atom-transfer radical polymerization and was appended to the hydrogel network in a two-step acid-base-catalyzed sol-gel process. The pCBMA silica aerogels were obtained by drying the hydrogels under supercritical conditions using CO(2). To understand the effect of pCBMA on the gel structure, pCBMA silica aerogels with different pCBMA contents were characterized using scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) spectroscopy, and the surface area from Brauner-Emmet-Teller (BET) measurements. The antifouling property of pCBMA silica hydrogel to resist protein (fibrinogen) adsorption was measured using enzyme-linked immunosorbent assay (ELISA). SEM images revealed that the particle size and porosity of the silica network decreased at low pCBMA content and increased at above 33 wt % of the polymer. The presence of pCBMA increased the surface area of the material by 91% at a polymer content of 25 wt %. NMR results confirmed that pCBMA was incorporated completely into the silica structure at a polymer content below 20 wt %. A protein adsorption test revealed a reduction in fibrinogen adsorption by 83% at 25 wt % pCBMA content in the hydrogel compared to the fibrinogen adsorption in the unmodified silica hydrogel. 相似文献
865.
Prof. Viktor Brabec Dr. Jaroslav Malina Dr. Nicola Margiotta Prof. Giovanni Natile Prof. Jana Kasparkova 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(48):15439-15448
To determine how the Y‐family translesion DNA polymerase η (Polη) processes lesions remains fundamental to understanding the molecular origins of the mutagenic translesion bypass. We utilized model systems employing a DNA double‐base lesion derived from 1,2‐GG intrastrand cross‐links of a new antitumor PtII complex containing a bulky carrier ligand, namely [PtCl2(cis‐1,4‐dach)] (DACH=diaminocyclohexane). The catalytic efficiency of Polη for the insertion of correct dCTP, with respect to the other incorrect nucleotides, opposite the 1,2‐GG cross‐link was markedly reduced by the DACH carrier ligand. This reduced efficiency of Polη to incorporate the correct dCTP could be due to a more extensive DNA unstacking and deformation of the minor groove induced in the DNA by the cross‐link of bulky [PtCl2(cis‐1,4‐dach)]. The major products of the bypass of this double‐base lesion produced by [PtCl2(cis‐1,4‐dach)] by Polη resulted from misincorporation of dATP opposite the platinated G residues. The results of the present work support the thesis that this misincorporation could be due to sterical effects of the bulkier 1,4‐DACH ligand hindering the formation of the Polη–DNA–incoming nucleotide complex. Calorimetric analysis suggested that thermodynamic factors may contribute to the forces that governed enhanced incorporation of the incorrect dATP by Polη as well. 相似文献
866.
Mohammed Ikbal Rakesh Banerjee Sanghamitra Atta Avijit Jana Dibakar Dhara Anakuthil Anoop Dr. N. D. Pradeep Singh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(38):11968-11975
A new class of carboxylate and sulfonate esters of 1‐hydroxy‐2(1H)‐quinolone has been demonstrated as nonionic photoacid generators (PAGs). Irradiation of carboxylates and sulfonates of 1‐hydroxy‐2(1H)‐quinolone by UV light (λ≥310 nm) resulted in homolysis of weak N? O bond leading to efficient generation of carboxylic and sulfonic acids, respectively. The mechanism for the homolytic N? O bond cleavage was supported by time‐dependent DFT calculations. Photoresponsive 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–methyl methacrylate (SSQL‐MMA) and 1‐(p‐styrenesulfonyloxy)‐2‐quinolone–lauryl acrylate (SSQL‐LA) copolymers were synthesized from PAG monomer 1‐(p‐styrenesulfonyloxy)‐2‐quinolone, and subsequently controlled surface wettability was demonstrated for the above‐mentioned photoresponsive polymers. 相似文献
867.
Andreas Schlundt Wolfgang Kilian Dr. Michael Beyermann Dr. Jana Sticht Dr. Sebastian Günther Sabine Höpner Kirsten Falk Dr. Olaf Roetzschke Dr. Lorenz Mitschang Dr. Christian Freund Dr. 《Angewandte Chemie (International ed. in English)》2009,48(23):4142-4145
Caged in : The formation of a complex between a peptide ligand and a major histocompatibility complex (MHC) class II protein is detected by a 129Xe biosensor. Cryptophane molecules that trap Xe atoms are modified with a hemagglutinin (HA) peptide, which binds to the MHC protein. The interaction can be monitored by an NMR chemical shift change of cage–HA bound 129Xe.
868.
Anukul Jana SakyaS. Sen HerbertW. Roesky Carola Schulzke Sudipta Dutta SwapanK. Pati 《Angewandte Chemie (International ed. in English)》2009,48(23):4246-4248
A happy ending : The germanium(II) hydride [LGeH], where L=[HC{(CMe)(2,6‐iPr2C6H3N)}2], reacts with a diazoalkane to form the hydrazone derivative (see picture). The reaction proceeds through the unprecedented end‐on nitrogen insertion of the diazo compound.
869.
Michaela Pekarova Jana Kralova Lukas Kubala Milan Ciz Antonin Lojek Cenek Gregor Jan Hrbac 《Analytical and bioanalytical chemistry》2009,394(5):1497-1504
In this study, we realized the continual and long-term electrochemical detection of NO production by stimulated macrophages
using modified porphyrinic microsensor. The NO release from RAW 264.7 cells stimulated by lipopolysaccharide started 5 h after
the lipopolysaccharide administration. After reaching its maximum at the sixth hour, the stable level of NO production was
observed between the seventh and 12th hour of the experiment. This phase was followed by a gradual decline in NO production.
A close correlation between the NO signal detected with microelectrode and nitrite accumulation, which had been determined
in supernatants removed from stimulated cells, was observed. This finding was utilized for the calibration of the electrochemical
experiment. The presence of iNOS enzyme, which constitutes a main requirement for NO production by stimulated macrophages,
was confirmed by Western blot analysis of iNOS protein expression at key time points of the corresponding electrochemical
experiment. The capability of our microsensor to instantaneously monitor the changes in the NO production by stimulated RAW
264.7 cells was demonstrated by the immediate decrease in the signal due to NO as a response to the addition of iNOS inhibitor
into the cell culture medium.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
870.
The first example of nucleophilic substitution with perfluoroalkyl Grignard reagents on the sp3 carbon centre is described. Thus, a series of organometals RF-MgBr, prepared from perfluorinated alkyl iodides RF-I with RF = C4F9, C6F13, C8F17, C10F21 and C12F25, reacted with 1,3,2-dioxathiolane-2,2-dioxide to afford the corresponding 2-(perfluoroalkyl)ethyl magnesium sulfates, which were isolated after metathesis to the corresponding potassium salts. In the model reaction, perfluorohexylmagnesium iodide was reacted with methyl triflate yielding polyfluorinated alkane. The attempts to extend the reaction to 1,3,2-dioxathiane-2,2-dioxide were unsuccessful due to its inferior reactivity and only reduced polyfluoroalkane and the product of coupling were detected in the reaction mixture. Polyfluorinated sulfates are easily hydrolyzed with hydrochloric or triflic acid to the corresponding alcohols, which is an alternative to standard transformation of perfluoroalkyl iodides to 2-(perfluoroalkyl)ethanols. Quantum-chemical calculations of the PES of the reaction with both sulfur-containing heterocycles found that the failure of the reaction with 1,3,2-dioxathiane-2,2-dioxide is caused by higher activation energy of the process. 相似文献