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211.
一个无重复生成所有可逆矩阵的算法 总被引:2,自引:0,他引:2
在本文中,我们给聘个无重复生成所有可逆矩阵的算法,并估计了该算法的计算复杂度。 相似文献
212.
铁铬系高(中)温变换催化剂研究现状 总被引:14,自引:0,他引:14
本文介绍和评述了国内外铁铬系高(中)温变换催化剂的现状和研究动态,其中包括铁铬系高温变换催化剂的应用和研究意义、变换反应的机理以及各种助剂的影响,并指出了该研究的发展趋势。 相似文献
213.
Summary One classical method for quantitation of amino acids in proteins is hydrolysis of the proteins and determination of the free
amino acids. Although the drastic experimental conditions necessary for complete hydrolysis always cause degradation of some
of the amino acids, if mild hydrolysis conditions are used, a mixture of amino acids and oligopeptides is obtained. If these
conditions are adequately tuned, the oligopeptides are almost exclusively dipeptides. For this reason we have initiated a
study to find a derivatizing agent suitable for the analysis of amino acids and dipeptides by an absolute method of quantitation
already tested for amino acids. FMOC-Cl was found to be a suitable derivatizing agent for this purpose. 相似文献
214.
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216.
Baohua Zhang Yi Kong Huijun Liu Bin Chen Bolin Zhao Yelin Luo Lijuan Chen Yuwei Zhang Dongxue Han Zujin Zhao Ben Zhong Tang Li Niu 《Chemical science》2021,12(40):13283
Due to overcoming the limitation of aggregation caused quenching (ACQ) of solid-state emitters, aggregation-induced emission (AIE) organic luminogens have become a promising candidate in aqueous electrochemiluminescence (ECL). However, restricted by the physical nature of fluorescence, current organic AIE luminogen-based ECL (AIECL) faces the bottleneck of low ECL efficiency. Here, we propose to construct de novo aqueous ECL based on aggregation-induced delayed fluorescence (AIDF) luminogens, called AIDF-ECL. Compared with the previous organic AIE luminogens, purely organic AIDF luminogens integrate the superiorities of both AIE and the utilization of dark triplets via thermal-activated spin up-conversion properties, thereby possessing the capability of close-to-unity exciton utilization for ECL. The results show that the ECL characteristics using AIDF luminogens are directly related to their AIDF properties. Compared with an AIECL control sample based on a tetraphenylethylene AIE moiety, the ECL efficiency of our AIDF-ECL model system is improved by 5.4 times, confirming the excellent effectiveness of this innovative strategy.Electrochemiluminescence (ECL) using an aggregation-induced delayed fluorescence (AIDF) organic luminogen, i.e. AIDF-ECL, was reported for the first time, featuring “lighting” dark triplets (ca. 75% in total) for all-exciton-harvesting ECL applications. 相似文献
217.
Zhong‐Zhen Yu Ming Lei Yu‐Chun Ou Guisheng Yang Guo‐Hua Hu 《Journal of Polymer Science.Polymer Physics》2000,38(21):2801-2809
A reactive extrusion process was developed to toughen an amorphous copolyester (PETG) of ethylene glycol, terephthalic acid and 1,4‐cyclohexanedimethanol using either a maleic anhydride grafted polyethylene–octene elastomer (POEg), or a maleic anhydride grafted mixture (TPEg) of the polyethylene–octene elastomer and a semicrystalline polyolefin plastic as the impact modifier. TPEg showed an important toughening effect on the PETG. A sharp ductile‐brittle transition was observed when the TPEg content was about 10 wt %. For POEg toughened PETG, the ductile–brittle transition required a higher content in POEg, ∼15 wt %. Evolution of the topography and morphology of the blends and the relationship between impact strength and topography were discussed. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2801–2809, 2000 相似文献
218.
提出了一种具有预调制腔、主谐振腔和提取腔组成的多腔轴向提取虚阴极振荡器结构。腔体特性分析表明其在工作频段可以获得更高的提取效率。粒子模拟显示该结构在电压700 kV,电流23 kA的条件下,可输出功率大于1.7 GW,频率4.0 GHz,功率效率大于10%的微波。初步的实验研究获得了辐射功率约700 MW,频率约4.1 GHz的微波输出。对实验结果的进一步分析表明,通过适当加大器件虚阴极振荡工作区微波管直径的方法可以有效改善器件的谐振性能,从而获得更好的工作性能。 相似文献
219.
Pan Zhou Haiyu Zhou Yingchun Xia Qingqing Feng Xian Kong Wen-hui Hou Yu Ou Xuan Song Hang-yu Zhou Weili Zhang Yang Lu Fengxiang Liu Qingbin Cao Hao Liu Shuaishuai Yan Kai Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(19):e202316717
The electrolytes for lithium metal batteries (LMBs) are plagued by a low Li+ transference number (T+) of conventional lithium salts and inability to form a stable solid electrolyte interphase (SEI). Here, we synthesized a self-folded lithium salt, lithium 2-[2-(2-methoxy ethoxy)ethoxy]ethanesulfonyl(trifluoromethanesulfonyl) imide (LiETFSI), and comparatively studied with its structure analogue, lithium 1,1,1-trifluoro-N-[2-[2-(2-methoxyethoxy)ethoxy)]ethyl]methanesulfonamide (LiFEA). The special anion chemistry imparts the following new characteristics: i) In both LiFEA and LiETFSI, the ethylene oxide moiety efficiently captures Li+, resulting in a self-folded structure and high T+ around 0.8. ii) For LiFEA, a Li−N bond (2.069 Å) is revealed by single crystal X-ray diffraction, indicating that the FEA anion possesses a high donor number (DN) and thus an intensive interphase “self-cleaning” function for an ultra-thin and compact SEI. iii) Starting from LiFEA, an electron-withdrawing sulfone group is introduced near the N atom. The distance of Li−N is tuned from 2.069 Å in LiFEA to 4.367 Å in LiETFSI. This alteration enhances ionic separation, achieves a more balanced DN, and tunes the self-cleaning intensity for a reinforced SEI. Consequently, the fast charging/discharging capability of LMBs is progressively improved. This rationally tuned anion chemistry reshapes the interactions among Li+, anions, and solvents, presenting new prospects for advanced LMBs. 相似文献
220.
Dr. Fenghua Ding Atsunori Doi Dr. Takafumi Ogawa Dr. Hiroki Ubukata Dr. Tong Zhu Dr. Daichi Kato Dr. Cédric Tassel Dr. Itaru Oikawa Dr. Naoki Inui Dr. Satoru Kuze Tsutomu Yamabayashi Dr. Kotaro Fujii Prof. Masatomo Yashima Prof. Xing Ou Dr. Zhijian Wang Prof. Xiaobo Min Prof. Koji Fujita Prof. Hitoshi Takamura Prof. Akihide Kuwabara Tianren Zhang Prof. Kent J. Griffith Prof. Zhang Lin Prof. Liyuan Chai Prof. Hiroshi Kageyama 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(15):e202401779
The Li3MX6 compounds (M=Sc, Y, In; X=Cl, Br) are known as promising ionic conductors due to their compatibility with typical metal oxide cathode materials. In this study, we have successfully synthesized γ-Li3ScCl6 using high pressure for the first time in this family. Structural analysis revealed that the high-pressure polymorph crystallizes in the polar and chiral space group P63mc with hexagonal close-packing (hcp) of anions, unlike the ambient-pressure α-Li3ScCl6 and its spinel analog with cubic closed packing (ccp) of anions. Investigation of the known Li3MX6 family further revealed that the cation/anion radius ratio, rM/rX, is the factor that determines which anion sublattice is formed and that in γ-Li3ScCl6, the difference in compressibility between Sc and Cl exceeds the ccp rM/rX threshold under pressure, enabling the ccp-to-hcp conversion. Electrochemical tests of γ-Li3ScCl6 demonstrate improved electrochemical reduction stability. These findings open up new avenues and design principles for lithium solid electrolytes, enabling routes for materials exploration and tuning electrochemical stability without compositional changes or the use of coatings. 相似文献