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211.
Charge‐Transfer‐Induced Fluorescence Quenching of Anthracene Derivatives and Selective Detection of Picric Acid
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Dines Chandra Santra Manas Kumar Bera Dr. Pradip Kumar Sukul Dr. Sudip Malik 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(6):2012-2019
2,6‐Divinylpyridine‐appended anthracene derivatives flanked by two alkyl chains at the 9,10‐position of the core have been designed, synthesized, and characterized by NMR, MALDI‐TOF, FTIR, and single‐crystal XRD. These anthracene derivatives are able to recognize picric acid (2,4,6‐trinitrophenol, PA) selectively down to parts per billion (ppb) level in aqueous as well as nonaqueous medium. Fluorescence emission of these derivatives in solution is significantly quenched by adding trace amounts of PA, even in the presence of other competing analogues, such as 2,4‐dinitrophenol (2,4‐DNP), 4‐nitrophenol (NP), nitrobenzene (NB), benzoic acid (BA), and phenol (PH). The high sensitivity of these derivatives toward PA is considered as a combined effect of the proton‐induced intramolecular charge transfer (ICT) as well as electron transfer from the electron‐rich anthracene to the electron‐deficient PA. Moreover, visual detection of PA has been successfully demonstrated in the solid state by using different substrates. 相似文献
212.
Vahab Solouki Bonab Ica Manas‐Zloczower 《Journal of Polymer Science.Polymer Physics》2017,55(20):1553-1564
Thermoplastic polyurethanes (TPUs) are among the most versatile engineering polymers. The presence of hard and soft segments on their backbone and specific hydrogen bond interactions between the hard segments, provide TPUs with outstanding engineering properties while rendering them as very complex systems to study. Knowledge of morphology–property relationship is essential for TPUs since their thermal and mechanical behavior are directly dictated by their complicated morphology. In this research, TPU morphological features related to the hard segment content (HSC) were explored in tandem with system macroscopic properties. It was observed that TPUs display multiscale phase separated morphology with specific morphological features dependent on the HSC. At a certain critical HSC, an interconnected network of hard segments was formed which resulted in significant changes in TPU properties. This was explained in analogy with percolation phenomena in filler reinforced systems and considering the hard segments as reinforcing agent. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1553–1564 相似文献
213.
Mahajan Priya Wadhwa Bhumika Barik Manas Ranjan Malik Fayaz Nargotra Amit 《Molecular diversity》2020,24(1):45-60
Molecular Diversity - The traditional method of drug discovery process has been surpassed by a rational approach where computer-aided drug designing plays a vital role in the identification of... 相似文献
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满足空间反射时间反演parity and time-reversal(PT)联合对称性的库源平衡宏观开放系统近几年成为一个研究热点.本文将PT对称性引入到动力学系统,用格子玻尔兹曼方法求解Navier-Stokes方程,发现在二维黏性流体中,如果进口和出口的条件完全等同,在低雷诺数流动中,流场的PT对称函数(ρ)随雷诺数(Re)的增高以ρn~Ren指数增长.用三种不同的速度剖面来驱动流体,计算流场达到稳定状态时的PT对称性.结果发现,进出口平衡的黏性管流中,ρn~Ren的规律在三种驱动模式中出现,表明流场的PT对称性是由流体本身决定的,与驱动模式没有关系,从此论证所得到的指数率的谱适性. 相似文献
216.
The design and synthesis of a new pterin-based ratiometric and sensitive ‘naked-eye’ sensor R for highly selective recognition of acetate are reported. The acidic lactam NH and the NH of 2-N-pivaloyl group of receptor R along with 2,4-dinitrophenyl hydrazone group having the other acidic NH moiety lead to the binding of acetate anion in a 1:2 ratio by change of spectroscopic behavior on complexation (UV–vis and 1H NMR studies) which is also proven by Job plot. The sharp color change from light yellow to violet promises R to be a useful chromogenic ratiometric sensor for acetate amongst other common anions. 相似文献
217.
Ray AK Bhattacharya S Banerjee M Mukherjee AK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(7):1375-1378
o-Chloranil has been shown to form 1:1 molecular complexes with pyridine and 2-, 3- and 4-picolines in CCl4 medium. Isosbestic points have been found but charge-transfer bands could not be detected. The formation constants of the complexes exhibit a very good linear free energy relationship from which the Hammett p parameter for the complexation reaction is found to be -3.67. 相似文献
218.
We consider the nonlocal version of the Weinberg Salam model (following Kleppe et al.) with a finite parameter Λ signifying a fundamental length scale. We calculate the extra contributions to the anomalous magnetic moment of the muon coming from the nonlocal structure in this model. We find that the nonlocal contribution can be comparable to weak contributions and goes to increase theoretical estimates. We use this calculation to determine the limit on the scale of nonlocality. We obtain the result 1/Λ ? 3 × 10?16cm, which could be improved when present experimental errors narrow down. 相似文献
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220.
Michel Fleck Manas Layek Rajat Saha Debasis Bandyopadhyay 《Transition Metal Chemistry》2013,38(7):715-724
Three new Schiff base complexes, namely [Mn(L)Cl] · H2O (1), [Co(L)Cl]2 · 2CH3COCH3 (2) and [Co(L)NCS]2 (3), where H2L = 2,2′-[propane-1,2-diylbis(nitriloeth-1-yl-1-ylidene)]diphenol, have been prepared and characterized. The syntheses of 1 and 2 have been achieved by reacting equimolar amounts of the respective metal chloride and the tetradentate Schiff base ligand (H2L). While the mononuclear Mn(III) complex 1 was obtained with MnCl2 in acetone medium, the same synthetic system yielded the binuclear Co(III) complex 2 in the presence of CoCl2. Dissolution of 1 and 2 followed by crystallization with ammonium thiocyanate in methanol yielded two isostructural phenoxo-bridged binuclear complexes, namely [Mn(L)NCS]2 (previously reported by us) and a new complex [Co(L)NCS]2 (3), respectively. All the complexes 1–3 have been characterized by microanalytical, spectroscopic, single crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1 adopts a distorted tetragonal pyramidal geometry while 2 and 3 comprise dimeric Co(III) units with bridging phenolate oxygen atoms. All the complex units in 1–3 and the respective solvent molecules are held together by weak intermolecular H-bonding to constitute a supramolecular network in the solid state. The antibacterial activity of the complexes has been tested against some Gram(+) and Gram(?) bacteria. 相似文献