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921.
922.
923.
Yuetian Yan Guodong Chen Hui Wei Richard Y.-C. Huang Jingjie Mo Don L. Rempel Adrienne A. Tymiak Michael L. Gross 《Journal of the American Society for Mass Spectrometry》2014,25(12):2084-2092
Epitope mapping is an important tool for the development of monoclonal antibodies, mAbs, as therapeutic drugs. Recently, a class of therapeutic mAb alternatives, adnectins, has been developed as targeted biologics. They are derived from the 10th type III domain of human fibronectin (10Fn3). A common approach to map the epitope binding of these therapeutic proteins to their binding partners is X-ray crystallography. Although the crystal structure is known for Adnectin 1 binding to human epidermal growth factor receptor (EGFR), we seek to determine complementary binding in solution and to test the efficacy of footprinting for this purpose. As a relatively new tool in structural biology and complementary to X-ray crystallography, protein footprinting coupled with mass spectrometry is promising for protein–protein interaction studies. We report here the use of fast photochemical oxidation of proteins (FPOP) coupled with MS to map the epitope of EGFR-Adnectin 1 at both the peptide and amino-acid residue levels. The data correlate well with the previously determined epitopes from the crystal structure and are consistent with HDX MS data, which are presented in an accompanying paper. The FPOP-determined binding interface involves various amino-acid and peptide regions near the N terminus of EGFR. The outcome adds credibility to oxidative labeling by FPOP for epitope mapping and motivates more applications in the therapeutic protein area as a stand-alone method or in conjunction with X-ray crystallography, NMR, site-directed mutagenesis, and other orthogonal methods. Figure
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924.
Li-Yi Chen Wei-Cheng Wu Huan-Tsung Chang 《Journal of the American Society for Mass Spectrometry》2014,25(11):1944-1952
Quantitation of cytochrome c (Cyt c) in cell lysates through surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using gold nanoparticles (Au NPs) as the matrix and GR-10 peptide as an internal standard has been demonstrated. To shorten digestion time, temperature sensitive microgels containing trypsin (TR) and Au NPs have been employed. As-prepared functional microgels (TR/Au NPs/MGs) allow digestion of Cyt c within 15 s under microwave irradiation. The internal standard SALDI-MS approach provides linearity (R2 = 0.98) of MS signal ratio (I 1168.6/I 1067.6) of the tryptic digested peptide (m/z 1168.6) to GR-10 peptide (m/z 1067.6) against the concentration of Cyt c ranging from 25 to 200 nM, with a limit of detection (at a signal-to-noise ratio of 3) of 10 nM. This approach has been validated by the analysis of the lysates of HeLa cells, with an average concentration of 13.7?±?3.5 μM for cytoplasmic Cyt c. Increased concentrations of Cyt c in the HeLa cells treated with etoposide (a commercial drug) or carbon dots (potential drug) have been revealed through this simple, sensitive, and rapid SALDI-MS approach, supporting the drugs induced Cyt c-mediated apoptosis of the cells. This study has shown that this internal standard SALDI-MS approach holds great potential for cell study. Graphical Abstract
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925.
Qiang Chen Zheng Fang Shaofen Wang 《Journal of Thermal Analysis and Calorimetry》2014,115(2):1799-1804
A specially designed thermo-electrochemical calorimeter was applied to measure the electrochemical Peltier heats (EPH) of Fe(CN) 6 3?/4? system at 295.15 K. The curves of the electrode potential changes and temperature changes against time for Fe(CN) 6 3?/4? couple with five groups of different concentrations were obtained under the condition of various constant-current polarizations. The EPH values for the considered electrode reaction are determined to be ?41.31, ?42.73, ?44.28, ?45.87, and ?46.65 kJ mol?1 at the respective concentrations of 0.125, 0.175, 0.225, 0.275, and 0.300 mol dm?3; and the EPH and the apparent enthalpy change corresponding to the infinite dilution to be ?37.42 and ?84.10 kJ mol?1 at 295.15 K, respectively. 相似文献
926.
Meng Li Hong‐Ye Bai Zu‐Lin Da Xu Yan Chao Chen Jin‐Hui Jiang Wei‐Qiang Fan Wei‐Dong Shi 《Crystal Research and Technology》2015,50(3):244-249
CaFe2O4/MgFe2O4 nanowires with heterostructure had been successfully synthesized by electrospinning method. The obtained samples were systematically characterized by scanning electron microscopy (SEM), X‐Ray diffraction (XRD), UV–Vis diffuse reflectance spectra (UV‐Vis DR) and Environment scanning electron microscopy (ESEM). The novel CaFe2O4/MgFe2O4 nanowires exhibit an enhanced photocatalytic activity for degrading of tetracycline (TC) under visible light. Compared with bare CaFe2O4 or MgFe2O4 samples, the prepared CaFe2O4/MgFe2O4 (Ca:Mg:Fe = 3:2:10) composited nanowires show the best photocatalytic performance with a degradation efficiency of 40% after 150 min reaction time. This enhancement is attributed to the heterostructure of CaFe2O4/MgFe2O4 nanowires, which effectively repress the recombination of photo‐generated electrons and holes. Based on heterostructure and energy band positions, the enhancement of mechanism under visible‐light enhances the photocatalytic activity. 相似文献
927.
Jun-Wei Chen Yu-Yi Kuo Kuan-Ting Chen Chao-Ran Wang Chih-Yu Chao 《Molecular Crystals and Liquid Crystals》2015,611(1):139-145
We demonstrate that the supramolecular structure can be formed through the fibrous self-assembly of the polyfluorene-based polymer F8BT in liquid crystal (LC) 5CB. With the utility of alignment layer, the F8BT molecules can be aligned and formed oriented polymer network. We found that the presence of oriented polymer network makes twisted nematic LC exhibit excellent electro-optical properties (EO) of driving voltage reduction and EO bump peak elimination. The polyfluorene-based supramolecular structure provides the function of stabilizing LC molecules. We consider this functional self-assembled network has potential to apply in various devices for the ability of improving performance in operating property. 相似文献
928.
Azobenzene‐Functionalized Metal–Organic Polyhedra for the Optically Responsive Capture and Release of Guest Molecules 下载免费PDF全文
Dr. Jinhee Park Dr. Lin‐Bing Sun Ying‐Pin Chen Zachary Perry Prof. Dr. Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2014,53(23):5842-5846
Stimuli‐responsive metal–organic polyhedra (srMOPs) functionalized with azobenzene showed UV‐irradiation‐induced isomerization from the insoluble trans‐srMOP to the soluble cis‐srMOP, whereas irradiation with blue light reversed this process. Guest molecules were trapped and released upon cis‐to‐trans and trans‐to‐cis isomerization of the srMOPs, respectively. This study provides a new direction in the ever‐diversifying field of MOPs, while laying the groundwork for a new class of optically responsive materials. 相似文献
929.
JPC – Journal of Planar Chromatography – Modern TLC - 相似文献
930.
Dr. Liuyi Li Dr. Zhilin Chen Dr. Hong Zhong Prof. Dr. Ruihu Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(11):3050-3060
Two urea‐based porous organic frameworks, UOF‐1 and UOF‐2, were synthesized through a urea‐forming condensation of 1,3,5‐benzenetriisocyanate with 1,4‐diaminobenzene and benzidine, respectively. UOF‐1 and UOF‐2 possess good hydrophilic properties and high scavenging ability for palladium. Their palladium polymers, PdII/UOF‐1 and PdII/UOF‐2, exhibit high catalytic activity and selectivity for Suzuki–Miyaura cross‐coupling reactions and selective reduction of nitroarenes in water. The catalytic reactions can be efficiently performed at room temperature. Palladium nanoparticles with narrow size distribution were formed after the catalytic reaction and were well dispersed in UOF‐1 and UOF‐2. XPS analysis confirmed the coordination of the urea oxygen atom with palladium. SEM and TEM images showed that the original network morphology of UOF‐1 and UOF‐2 was maintained after palladium loading and catalytic reactions. 相似文献