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991.
Genetic heterogeneity of prostatic carcinoma-derived cell lines as emphasized by DNA fingerprinting.
S Bettink B Wullich A Christmann T Zwergel K D Zang G Unteregger 《Electrophoresis》1992,13(9-10):644-646
To investigate genetic heterogeneity during in vitro cultivation of human prostatic carcinomas following radical prostatectomy we performed DNA fingerprinting using the digoxygenin-labeled probes (GACA)4 and (GTG)5. DNA was isolated from fresh material stemming from different areas within one tumor and from cell cultures of the same material. The patterns which were obtained by the nucleolar organizer region (NOR)-specific probe (GACA)4 exhibit only a few prominent low molecular mass bands and no differences were observed between any of the tumors analyzed so far. Changes in the fingerprint pattern occurred between cell cultures derived from different areas within one tumor when the DNA was cleaved by HaeIII and signals detected with the (GTG)5 probe. The "area-specific" pattern was stable during several subcultivations of these cell lines, indicating genetic stability of these prostatic carcinoma cells in vitro. Thus individual cell lines derived from radical prostatectomy seem to represent a biological system very close to the situation in vivo. 相似文献
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993.
Abid Naeem Chengqun Yu Weifeng Zhu Xuanbin Chen Xuan Wu Lihua Chen Zhenzhong Zang Yongmei Guan 《Molecules (Basel, Switzerland)》2022,27(23)
Traditional wound dressings often cannot treat wounds caused by bacterial infections or other wound types that are insensitive to these wound treatments. Therefore, a biodegradable, bioactive hydrogel wound dressing could be an effective alternative option. The purpose of this study was to develop a hydrogel membrane comprised of sodium alginate, polyvinyl alcohol, acrylic acid, and gallic acid for treating skin wounds. The newly developed membranes were analyzed using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), sol-gel fraction, porosity, mechanical strength, swelling, drug release and data modelling, polymeric network parameters, biodegradation, and antioxidation (DPPH and ABTS) and antimicrobial activity against Gram-positive and negative bacteria. The results revealed that hydrogel membranes were crosslinked successfully and had excellent thermal stability, high drug loading, greater mechanical strength, and exhibited excellent biodegradation. Additionally, the swelling ability and the porosity of the surface facilitated a controlled release of the encapsulated drug (gallic acid), with 70.34% release observed at pH 1.2, 70.10% at pH 5.5 (normal skin pH), and 86.24% at pH 7.4 (wounds pH) in 48 h. The gallic acid-loaded hydrogel membranes showed a greater area of inhibition against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli bacteria as well as demonstrated excellent antioxidant properties. Based on Franz cell analyses, the permeation flux of the drug from optimized formulations through mice skin was 92 (pH 5.5) and 110 (pH 7.4) μg/cm2·h−1. Moreover, hydrogel membranes retained significant amounts of drug in the skin for 24 h, such as 2371 (pH 5.5) and 3300 µg/cm2 (pH 7.4). Acute dermal irritation tests in rats showed that hydrogel membranes were nonirritating. Hydrogel membranes containing gallic acid could be an effective option for improving wound healing and could result in faster wound healing. 相似文献
994.
CuiPing Tang XingXue Dai JianWei Du DongLiang Li XiaoYa Zang XiangYang Yang DeQing Liang 《中国科学:化学(英文版)》2010,53(12):2622-2627
Pipeline blockage by gas hydrates is a serious problem in the petroleum industry. Low-dosage inhibitors have been developed for its cost-effective and environmentally acceptable characteristics. In a 1.072-L reactor with methane, ethane and propane gas mixture under the pressure of about 8.5 MPa at 4 °C, hydrate formation was investigated with low-dosage hydrate inhibitors PVP and GHI1, the change of the compressibility factor and gas composition in the gas phase was analyzed, the gas contents in hydrates were compared with PVP and GHI1 added, and the inhibition mechanism of GHI1 was discussed. The results show that PVP and GHI1 could effectively inhibit the growth of gas hydrates but not nucleation. Under the experimental condition with PVP added, methane and ethane occupied the small cavities of the hydrate crystal unit and the ability of ethane entering into hydrate cavities was weaker than that of methane. GHI1 could effectively inhibit molecules which could more readily form hydrates. The ether and hydroxy group of diethylene glycol monobutyl ether have the responsibility for stronger inhibition ability of GHI1 than PVP. 相似文献
995.
Zang X Luo R Song N Chen TK Bozigian H 《Rapid communications in mass spectrometry : RCM》2005,19(22):3259-3268
An on-line solid-phase extraction liquid chromatography/tandem mass spectrometry (SPE LC/MS/MS) assay using a newly developed SPE column and a monolithic column was developed and validated for direct analysis of plasma samples containing multiple analytes. This assay was developed in an effort to increase bioanalysis throughput and reduce the complexity of on-line SPE LC/MS/MS systems. A simple column-switching configuration that requires only one six-port valve and one HPLC pumping system was employed for on-line plasma sample preparation and subsequent gradient chromatographic separation. The resulting analytical method couples the desired sensitivity with ease of use. The method was found to perform satisfactorily for direct plasma analysis with respect to assay linearity, specificity, sensitivity, precision, accuracy, carryover, and short-term stability of an eight-analyte mixture in plasma. A gradient LC condition was applied to separate the eight analytes that cannot be distinctly differentiated by MS/MS. With a run time for every injection of 2.8 min, a minimum of 300 direct plasma injections were made on one on-line SPE column without noticeable changes in system performance. Due to the ruggedness and simplicity of this system, generic methods can be easily developed and applied to analyze a wide variety of compounds in a high-throughput manner without laborious off-line sample preparation. 相似文献
996.
Yaping Zang Ilana Stone Michael S. Inkpen Fay Ng Tristan H. Lambert Colin Nuckolls Michael L. Steigerwald Xavier Roy Latha Venkataraman 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(45):16154-16158
A single‐molecule method has been developed based on the scanning tunneling microscope (STM) to selectively couple a series of aniline derivatives and create azobenzenes. The Au‐catalyzed oxidative coupling is driven by the local electrochemical potential at the nanostructured Au STM tip. The products are detected in situ by measuring the conductance and molecular junction elongation and compared with analogous measurements of the expected azobenzene derivatives prepared ex situ. This single‐molecule approach is robust, and it can quickly and reproducibly create reactions for a variety of anilines. We further demonstrate the selective synthesis of geometric isomers and the assembly of complex molecular architectures by sequential coupling of complementary anilines, demonstrating unprecedented control over bond formation at the nanoscale. 相似文献
997.
Smart Transformation of a Polyhedral Oligomeric Silsesquioxane Shell Controlled by Thiolate Silver(I) Nanocluster Core in Cluster@Clusters Dendrimers 下载免费PDF全文
Si Li Zhao‐Yang Wang Prof. Dr. Guang‐Gang Gao Bing Li Peng Luo Yu‐Jin Kong Prof. Dr. Hong Liu Prof. Dr. Shuang‐Quan Zang 《Angewandte Chemie (International ed. in English)》2018,57(39):12775-12779
Using polyhedral oligomeric silsesquioxane (POSS) modified by a thiol group as a protected ligand, atom‐precise multi‐heteorocluster‐based dendrimers Ag12@POSS6 ( 1 a and 1 b ) were assembled. Through the reactive ?SH groups, six POSS shell ligands stabilize the central 12‐core silver(I) cluster by diverse Ag?S interactions. When such Ag12@POSS6 complex was stimulated by different solvents (acetone or tetrahydrofuran), the core Ag12 silver(I) cluster underwent reversible structural transformation between flattened cubo‐octahedral (in 1 a ) and normal cubo‐octahedral (in 1 b ); concomitantly shell POSS clusters rearranged from pseudo‐octahedral to quasi‐octahedral. Furthermore, the film matrix modified by 1 a or 1 b showed different hydrophobicity. 相似文献
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