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61.
Dr. Xiao‐Jun Tang Zuxiao Zhang Prof. Dr. William R. Dolbier Jr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):18961-18965
Photoredox‐catalyzed reductive difluoromethylation of electron‐deficient alkenes was achieved in one step under tin‐free, mild and neutral conditions. This protocol affords a facile method to introduce RCF2 (R=H, Ph, Me, and CH2N3) groups at sites β to electron‐withdrawing groups. It was found that TTMS (tris(trimethylsilyl)silane) served nicely as both the H‐atom donor and the electron donor in the catalytic cycle. Experimental and DFT computational results provided evidence that RCF2 (R=H, Ph, Me) radicals are nucleophilic in nature. 相似文献
62.
63.
Frontispiece: Gd‐DTPA‐Dopamine‐Bisphytanyl Amphiphile: Synthesis,Characterisation and Relaxation Parameters of the Nanoassemblies and Their Potential as MRI Contrast Agents 下载免费PDF全文
64.
The unusual tricyclo[6.4.0.04.9]dodecane framework was constructed in eight linear steps in 13%overall yield.An innovative strategy accessing the framework from bicyclo[3.3.1]nonanes was employed.The key steps involve a Robinson annulation,a base induced decarboxylation and epimerization in a single step,and an intramolecular alkylation. 相似文献
65.
Non‐Invasive Salivary Electrochemical Quantification of Paraquat Poisoning Using Boron Doped Diamond Electrode 下载免费PDF全文
Thiago Matheus Guimarães Selva William Reis de Araujo Thiago Regis Longo Cesar da Paixão 《Electroanalysis》2015,27(7):1642-1648
The present work describes the first electrochemical method for quantifying paraquat herbicide poisoning in human saliva samples. Paraquat shows two couples of well‐defined peaks in aqueous solution using a boron doped diamond (BDD) electrode. By using square wave voltammetry (SWV) technique under optimum experimental conditions, a linear analytical curve was obtained for paraquat concentrations ranging from 0.800 to 167 µmol L?1, with a detection limit of 70 nmol L?1. This method was applied to quantify paraquat spikes in human saliva samples and in two different water samples (tap and river). The recovery values obtained ranged from 83.0 to 104 % and 99.1 to 105 %, respectively, which highlight the accuracy of the proposed method. 相似文献
66.
Laser Machined Plastic Laminates: Towards Portable Diagnostic Devices for Use in Low Resource Environments 下载免费PDF全文
Jason C. Harper Bryan D. Carson George D. Bachand William D. Arndt Melissa R. Finley C. Jeffrey Brinker Thayne L. Edwards 《Electroanalysis》2015,27(11):2503-2512
Despite significant progress in development of bioanalytical devices cost, complexity, access to reagents and lack of infrastructure have prevented use of these technologies in resource‐limited regions. To provide a sustainable tool in the global effort to combat infectious diseases the diagnostic device must be low cost, simple to operate and read, robust, and have sensitivity and specificity comparable to laboratory analysis. In this mini‐review we describe recent work using laser machined plastic laminates to produce diagnostic devices that are capable of a wide variety of bioanalytical measurements and show great promise towards future use in low‐resource environments. 相似文献
67.
Dr. Oleksandr S. Kanishchev Prof. William R. Dolbier Jr. 《Angewandte Chemie (International ed. in English)》2015,54(1):280-284
Current approaches to prepare SF5‐substituted heterocycles during the synthesis of targeted heterocyclic compounds require the use of SF5‐functionalized aryl or alkyne reagents or SF5Cl as a source of the SF5 functional group. Herein we report that excess oxidative fluorination of 2,2′‐dipyridyl disulfide with a KF/Cl2/MeCN system leads to the formation of thirteen new 2‐pyridylsulfur chlorotetrafluorides (2‐SF4Cl‐pyridines). These molecules are found to undergo further chlorine–fluorine exchange reactions by treatment with silver(I) fluoride enabling ready access to a series of ten new substituted 2‐pyridylsulfur pentafluorides (2‐SF5‐pyridines). This is the first preparatively simple and readily scalable example of the transformation of an existing heterocyclic sulfur functionality to prepare SF5‐substituted heterocycles. 相似文献
68.
High Ethene/Ethane Selectivity in 2,2′‐Bipyridine‐Based Silver(I) Complexes by Removal of Coordinated Solvent 下载免费PDF全文
Dr. Matthew G. Cowan William M. McDanel Prof. Hans H. Funke Dr. Yuki Kohno Prof. Douglas L. Gin Prof. Richard D. Noble 《Angewandte Chemie (International ed. in English)》2015,54(19):5740-5743
Following removal of coordinated CH3CN, the resulting complexes [AgI(2,2′‐bipyridine)][BF4] ( 1 ) and [AgI(6,6′‐dimethyl‐2,2′‐bipyridine)][OTf] ( 2 ) show ethene/ethane sorption selectivities of 390 and 340, respectively, and corresponding ethene sorption capacities of 2.38 and 2.18 mmol g?1 when tested at an applied gas pressure of 90 kPa and a temperature of (20±1) °C. These ethene/ethane selectivities are 13 times higher than those reported for known solid sorbents for ethene/ethane separation. For 2 , ethene sorption reached 90 % of equilibrium capacity within 15 minutes, and this equilibrium capacity was maintained over the three sorption/desorption cycles tested. The rates of ethene sorption were also measured. To our knowledge, these are the first complexes, designed for olefin/paraffin separations, which have open silver(I) sites. The high selectivities arise from these open silver(I) sites and the relatively low molecular surface areas of the complexes. 相似文献
69.
Christopher B. Kelly Kyle M. Lambert Michael A. Mercadante John M. Ovian Prof. William F. Bailey Prof. Nicholas E. Leadbeater 《Angewandte Chemie (International ed. in English)》2015,54(14):4241-4245
A scalable, high yielding, rapid route to access an array of nitriles from aldehydes mediated by an oxoammonium salt (4‐acetylamino‐2,2,6,6‐tetramethylpiperidine‐1‐oxoammonium tetrafluoroborate) and hexamethyldisilazane (HMDS) as an ammonia surrogate has been developed. The reaction likely involves two distinct chemical transformations: reversible silyl‐imine formation between HMDS and an aldehyde, followed by oxidation mediated by the oxoammonium salt and desilylation to furnish a nitrile. The spent oxidant can be easily recovered and used to regenerate the oxoammonium salt oxidant. 相似文献
70.
Cocrystal Formation through Mechanochemistry: from Neat and Liquid‐Assisted Grinding to Polymer‐Assisted Grinding 下载免费PDF全文
Dr. Dritan Hasa Gabriela Schneider Rauber Prof. Dario Voinovich Prof. William Jones 《Angewandte Chemie (International ed. in English)》2015,54(25):7371-7375
Mechanochemistry is an effective method for the preparation of multicomponent crystal systems. In the present work, we propose an alternative to the established liquid‐assisted grinding (LAG) approach. Polymer‐assisted grinding (POLAG) is demonstrated to provide a new class of catalysts for improving reaction rate and increasing product diversity during mechanochemical cocrystallization reactions. We demonstrate that POLAG provides advantages comparable to the conventional liquid‐assisted process, whilst eliminating the risk of unwanted solvate formation as well as enabling control of resulting particle size. It represents a new approach for the development of functional materials through mechanochemistry, and possibly opens new routes toward the understanding of the mechanisms and pathways of mechanochemical cocrystal formation. 相似文献