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为避免传统预测方法的参数取值主观性问题,采用参数随机产生的蒙特卡罗方法预测中国中长期煤炭需求。首先分析了经济增长、能源结构和产业结构三个主要煤炭需求影响因素,并基于1980~2015年间各影响因素及煤炭消费的历史数据和最小二乘法的多元线性回归拟合煤炭需求方程。在此基础上,构建各影响因素的概率分布,采用蒙特卡罗方法模拟1981~2015年的煤炭需求,发现仿真结果可以较好拟合现实,可作为仿真预测的有效工具。结合经济新常态和能源结构调整的现状,控制参数取值范围进行蒙特卡罗仿真预测,结果显示,2016~2025年的煤炭需求呈先上升后下降趋势,并于2020年达到需求的峰值40.25亿吨,这些结果对于煤炭产业的科学决策有重要的作用。 相似文献
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A comprehensive study on the efficient one‐pot synthesis of polyhedral octaphenylsilsesquioxane (OPS) is reported via the hydrolytic condensation of phenyltrimethoxysilane (PTMS) in the presence of basic catalyst to investigate the specific synthesis mechanism. The synthetic reactions are monitored with real time infrared (RTIR) spectroscopy. Then RTIR coupled with 29Si nuclear magnetic resonance spectroscopy (NMR) and matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF‐MS) are used to monitor the reactions and identify the intermediary species during the reaction. The rapid hydrolysis of PTMS is detected by RTIR. Contrary to previous reports, the ladder‐like structured species are identified as intermediates during the reaction process. It is suggested that formation of caged T8 OPS is realized through the chain break and rearrangement of the ladder‐like phenyltrimethoxysilanes. Accordingly, a scheme from hydrolysis of the PTMS to formation of the OPS is provided. 相似文献
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针对Ni单原子催化剂表面的CO2电还原反应(CO2RR), 提出了以Ni为活性位点的“单中心”机理以及同时借助Ni位点还原和碳氮锚定位水解的“双功能”机理. 依据稳态极化的实验结果, 开展了CO2RR的动力学解析与模型参数的敏感性分析; 借助暂态模型方程, 分别获取可表达CO2RR线性与非线性频响特征的电化学阻抗谱(EIS)与总谐波失真(THD)谱. 研究结果表明, CO2的溶解分压对CO2RR活性影响最显著. 若CO2RR遵循“单中心”机理, Ni位点COOHads的形成为速率控制步骤; 但若为“双功能”机理, 碳氮锚定位的水解与Ni位点的CO2,ads还原同为速率控制步骤. EIS理论上可用于区分CO2RR的“单中心”机理与“双功能”机理; 与之相比, THD谱在CO2RR的机理识别中并无优势. 相似文献
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Dr. Zhihe Qing Guoyan Luo Shuohui Xing Dr. Zhen Zou Dr. Yanli Lei Prof. Juewen Liu Prof. Ronghua Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(33):14148-14152
The Au−S bond is the classic way to functionalize gold nanoparticles (AuNPs). However, cleavage of the bond by biothiols and other chemicals is a long-standing problem hindering practical applications, especially in cells. Instead of replacing the thiol by a carbene or selenol for stronger adsorption, it is now shown that the Pt−S bond is much more stable, fully avoiding cleavage by biothiols. AuNPs were deposited with a thin layer of platinum, and an AuNP@Pt-S nanoflare was constructed to detect the miRNA-21 microRNA in living cells. This design retained the optical and cellular uptake properties of DNA-functionalized AuNPs, while showing high-fidelity signaling. It discriminated target cancer cells even in a mixed-cell culture system, where the Au-S based nanoflare was less sensitive. Compared to previous methods of changing the ligand chemistry, coating a Pt shell is more accessible, and previously developed methods for AuNPs can be directly adapted. 相似文献
47.
Dr. Yujia Qing Mira D. Liu Denis Hartmann Dr. Linna Zhou Dr. William J. Ramsay Prof. Hagan Bayley 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(36):15841-15846
We report a single-molecule mechanistic investigation into 2-cyanobenzothiazole (CBT) chemistry within a protein nanoreactor. When simple thiols reacted reversibly with CBT, the thioimidate monoadduct was approximately 80-fold longer-lived than the tetrahedral bisadduct, with important implications for the design of molecular walkers. Irreversible condensation between CBT derivatives and N-terminal cysteine residues has been established as a biocompatible reaction for site-selective biomolecular labeling and imaging. During the reaction between CBT and aminothiols, we resolved two transient intermediates, the thioimidate and the cyclic precursor of the thiazoline product, and determined the rate constants associated with the stepwise condensation, thereby providing critical information for a variety of applications, including the covalent inhibition of protein targets and dynamic combinatorial chemistry. 相似文献
48.
A novel PtSnNa/ZSM-5 monolithic catalyst was designed and synthesized for the propane dehydrogenation reaction, which was a significant transformation in industry. Experimental results showed that although the propane conversion and the propylene selectivity gradually fell down along with the reaction time, the descent speed of the PtSnNa/ZSM-5 monolithic catalyst was slower than that of the granule catalyst and the propane conversion and propylene selectivity of the reaction with monolithic catalyst still remained at a high level after 12 hr. The monolithic catalyst had regular pore structure that facilitated the separation of the product from the catalyst and reduced the limitation on internal and external diffusion and mass transfer, and led to the high catalytic activity and stability. The catalyst could be easily fabricated and was of highly industrial application potential. 相似文献
49.
The electronic sensitivity and effectiveness of the pristine, Fe,- Mg-, Al- and Ga-doped ZnO nanoclusters interacted with 5-fluorouracil (5-FU) anticancer drug are theoretically investigated in the gas phase using the B3LYP/wB97XD density functional theory calculations with LANL2DZ basis set. It is concluded that 5-FU adsorption on the doped nanoclusters has relatively higher adsorption energy as compared with the pristine zinc oxide. A number of thermodynamic parameters, such as band gap energy (Eg), adsorption energy (Ead), molecular electrostatic potential, global hardness (η) and density of electronic states, are attained and compared. Also, calculated geometrical parameters and electronic properties for the studied systems indicate that Mg- and Ga-doped Zn12O12 present higher sensitivity to 5-FU compared with the pristine nanocluster. Theoretical results reveal that adsorption of 5-FU on the doped nanoclusters is influenced by the electronic conductance of the nanocluster. Therefore, Mg- and Ga-doped ZnO can be considered as promising nanobiosensors for detection of 5-FU in medicine. 相似文献
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