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161.
Towards Fabrication of Atomic Dopant Wires via Monolayer Doping Patterned by Resist-Free Lithography 下载免费PDF全文
Fabrication of atomic dopant wires at large scale is challenging.We explored the feasibility to fabricate atomic dopant wires by nano-patterning self-assembled dopant carrying molecular monolayers via a resist-free lithographic approach.The resist-free lithography is to use electron beam exposure to decompose hydrocarbon contaminants in vacuum chamber into amorphous carbon that serves as an etching mask for nanopatterning the phosphorus-bearing monolayers.Dopant wires were fabricated in silicon by patterning diethyl vinylphosphonate monolayers into lines with a width ranging from 1 μm down to 8 nm.The dopants were subsequently driven into silicon to form dopant wires by rapid thermal annealing.Electrical measurements show a linear correlation between wire width and conductance,indicating the success of the monolayer patterning process at nanoscale.The dopant wires can be potentially scaled down to atomic scale if the dopant thermal diffusion can be mitigated. 相似文献
162.
Dr. Lei Dong Mengqi Fu Prof. Lifang Liu Hai-Hao Han Prof. Yi Zang Prof. Guo-Rong Chen Jia Li Prof. Xiao-Peng He Dr. Sébastien Vidal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(63):14445-14452
Two red-emitting dicyanomethylene-4H-pyran (DM) based fluorescent probes were designed and used for peroxynitrite (ONOO−) detection. Nevertheless, the aggregation-caused quenching effect diminished the fluorescence and restricted their further applications. To overcome this problem, tetraphenylethylene (TPE) based glycoclusters were used to self-assemble with these DM probes to obtain supramolecular water-soluble glyco-dots. This self-assembly strategy enhanced the fluorescence intensity, leading to an enhanced selectivity and activity of the resulting glyco-dot comparing to DM probes alone in PBS buffer. The glyco-dots also exhibited better results during fluorescence sensing of intracellular ONOO− than the probes alone, thereby offering scope for the development of other similar supramolecular glyco-systems for chemical biological studies. 相似文献
163.
164.
Dr. Xue Feng Lu Prof. Bao Yu Xia Prof. Shuang-Quan Zang Prof. Xiong Wen Lou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(12):4662-4678
In view of the clean and sustainable energy, metal–organic frameworks (MOFs) based materials, including pristine MOFs, MOF composites, and their derivatives are emerging as unique electrocatalysts for oxygen reduction reaction (ORR). Thanks to their tunable compositions and diverse structures, efficient MOF-based materials provide new opportunities to accelerate the sluggish ORR at the cathode in fuel cells and metal–air batteries. This Minireview first provides some introduction of ORR and MOFs, followed by the classification of MOF-based electrocatalysts towards ORR. Recent breakthroughs in engineering MOF-based ORR electrocatalysts are highlighted with an emphasis on synthesis strategy, component, morphology, structure, electrocatalytic performance, and reaction mechanism. Finally, some current challenges and future perspectives for MOF-based ORR electrocatalysts are also discussed. 相似文献
165.
Tienan Zang Yachen Xie Sa Su Feiran Liu Qianqian Chen Dr. Jing Jing Prof. Rubo Zhang Prof. Guangle Niu Prof. Xiaoling Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(25):10089-10093
Enzymes contain several subunits to maintain different biological functions. However, it remains a great challenge for specific discrimination of one subunit over another. Toward this end, the fluorescent probe TPEMA is now presented for highly specific detection of the B subunit of cytosolic creatine (CK) kinase isoenzyme (CK-B). Owing to its aggregation-induced emission property, TPEMA shows highly boosted emission toward CK-B with a fast response time and very low interference from other analytes, including the M subunit of CK (CK-M). With the aid of a Job plot assay, ITC assay and molecular dynamics simulation, it was directly confirmed that the remarkably enhanced fluorescence of TPEMA in the presence of CK-B results from the restriction of single molecular motion in the cavity. Selective wash-free fluorescence imaging of CK-B in macrophages under different treatments was successfully demonstrated. 相似文献
166.
167.
Yazhen Wang Rifang Li Hongge Jia Guoxing Yang Yutao Di Chenxi Xu Liqun Ma Hui Zhang Yongli Zhou Yu Zang Shuangping Xu Zhaoyang Sun Liwu Zu Chenge Yue Tianyu Lan 《Chemical Papers》2018,72(11):2871-2877
A novel peroxy group-containing silane coupling agent was synthesized and anchored on the surface of titanium dioxide nanoparticles (nano-TiO2) to form an immobilized-initiator-modified nano-TiO2 species. In this study, the kinetic parameters of the peroxy group-containing silane were tested and assessed using DSC. The pre-exponential factor (Ad) was 8.973?×?108 and the activation energy (Ea) was 80.736 kJ mol?1. Moreover, the empirical Arrhenius equation was determined to be ln Kd?=???80.736/RT?+?ln(8.973?×?108). To obtain continuous polymers, acrylonitrile (AN) and methyl methacrylate (MMA) were polymerized using the novel peroxy group-containing silane and FeSO4 as an initiator system. The number average molecular weights (Mn of PAN?=?3×104 and Mn of PMMA?=?1.4?×?105) and polydispersity indexes (PDI of PAN?=?2.76 and PDI of PMMA?=?1.65) were determined by GPC. It was suggested that the redox initiation system can generate highly reactive species on the surfaces of inorganic nanoparticles. The nano-TiO2-grafted polymers were successfully obtained. 相似文献
168.
Cong Li Rui Zang Pengxin Li Zengming Man Shijian Wang Xuemei Li Yuhan Wu Shuaishuai Liu Prof. Guoxiu Wang 《化学:亚洲杂志》2018,13(3):342-349
Prussian blue and its analogues (PBAs) have been recognized as one of the most promising cathode materials for room‐temperature sodium‐ion batteries (SIBs). Herein, we report high crystalline and Na‐rich Prussian white Na2CoFe(CN)6 nanocubes synthesized by an optimized and facile co‐precipitation method. The influence of crystallinity and sodium content on the electrochemical properties was systematically investigated. The optimized Na2CoFe(CN)6 nanocubes exhibited an initial capacity of 151 mA h g?1, which is close to its theoretical capacity (170 mA h g?1). Meanwhile, the Na2CoFe(CN)6 cathode demonstrated an outstanding long‐term cycle performance, retaining 78 % of its initial capacity after 500 cycles. Furthermore, the Na2CoFe(CN)6 Prussian white nanocubes also achieved a superior rate capability (115 mA h g?1 at 400 mA g?1, 92 mA h g?1 at 800 mA g?1). The enhanced performances could be attributed to the robust crystal structure and rapid transport of Na ions through large channels in the open‐framework. Most noteworthy, the as‐prepared Na2CoFe(CN)6 nanocubes are not only low‐cost in raw materials but also contain a rich sodium content (1.87 Na ions per lattice unit cell), which will be favorable for full cell fabrication and large‐scale electric storage applications. 相似文献
169.
Let A be a 0 − 1 matrix with precisely two 1’s in each column and let 1 be the all-one vector. We show that the problems of deciding whether the linear system
(1) defines an integral polyhedron,
(2) is totally dual integral (TDI), and
(3) box-totally dual integral (box-TDI)
are all co-NP-complete, thereby confirming the conjecture on NP-hardness of recognizing TDI systems made by Edmonds and Giles
in 1984.
Supported in part by NSA grant H98230-05-1-0081 and NSF grants DMS-0556091 and ITR-0326387.
Supported in part by the Research Grants Council of Hong Kong and Seed Funding for Basic Research of HKU. 相似文献
170.
Alejandro Capap Ming-Dong Zhou Shu-Liang Zang Fritz E. Kühn 《Journal of organometallic chemistry》2008,693(20):3240-3244
Equimolar reactions of the derivatives of ((2-hydroxynapthalen-1-yl)methylene)aniline with methyltrioxorhenium (MTO) lead to complexes 1–4, where MTO is coordinated via the oxygen of the former hydroxyl-group to MTO. The resulting complexes are very stable but not particularly catalytically active if no electron acceptor resides on the Schiff base. The electron withdrawing groups placed on the Schiff base ligand have the effect of increasing the catalytic activity but somewhat decrease the complex stability. 相似文献