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81.
82.
Mishra T De AK Chattopadhyay S Mallick PK Sett P 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,61(4):767-776
From the critical analyses of Raman and infrared spectra, different normal modes of vibration of diphenylmethane (DPM) have been identified. The near ultraviolet absorption spectra of the molecule are found to consist of two band systems, one around 220 nm and the other around 270 nm with respective f-values 5.23 x 10(-2) and 6.44 x 10(-3). The first system is broad and shows few diffuse structures, whereas the later one exhibits very well-resolved structure. They are respectively assigned as 1L(a) and 1L(b) bands. The Raman excitation profiles of several normal modes have been analyzed to get structural and other information of different excited electronic states. 相似文献
83.
A. K. Sarkar P. K. Mallick S. Chakravorti S. B. Banerjee 《Journal of Chemical Sciences》1983,92(3):197-201
The electronic absorption spectra of paramethoxy benzyl alcohol (pmba) and parachloro benzyl cyanide (pcbc) are described.
The broad features of the spectra of the molecules are consistent with allowed transition forC
2v symmetry. However, the solid state and glass matrix spectra of pmba at 77K indicate possible deviation from planarity in
the structure of the molecule. In pcbc, it is pointed out that intensity borrowing may be responsible for the large intensity
of the vibrationally-induced part of the spectra, in which non-totally symmetric vibrations are excited. 相似文献
84.
The kinetics of aqua ligand substitution fromcis-[Ru(bipy)2(H2O)2]2+ by 1, 10-phenanthroline (phen) have been studied spectrophotometrically in the 35 to 50°C temperature range. We propose the following rate law for the reaction within the 3.65 to 5.5 pH range:
相似文献
85.
Ahmad?T.?Ali F.?RahamanEmail author A.?Mallick 《International Journal of Theoretical Physics》2016,55(5):2469-2480
We have studied the conformal, homothetic and Killing vectors in the context of teleparallel theory of gravitation for plane-symmetric static spacetimes. We have solved completely the non-linear coupled teleparallel conformal Killing equations. This yields the general form of teleparallel conformal vectors along with the conformal factor for all possible cases of metric functions. We have found four solutions which are divided into one Killing symmetries and three conformal Killing symmetries. One of these teleparalel conformal vectors depends on x only and other is a function of all spacetime coordinates. The three conformal Killing symmetries contain three proper homothetic symmetries where the conformal factor is an arbitrary non-zero constant. 相似文献
86.
Rajashi Haldar Ajay Kumar Binit Mallick Prof. Swaroop Ganguly Dr. Dipankar Mandal Prof. Maheswaran Shanmugam 《Angewandte Chemie (International ed. in English)》2023,62(9):e202216680
Developing robust, wearable, and biocompatible energy harvesting devices with bulk oxides (ceramics and perovskites) is extremely hard to achieve due to their zero mechanical flexibility, heavy metal toxicity, and tunability of properties. Alternatively, discrete inorganic complexes can be an excellent choice to overcome the above-stated issues, thanks to appropriate molecular engineering. Herein, we report an above-room-temperature ferroelectric discrete molecular complex [Cu(L-phe)(bpy)(H2O)]PF6⋅H2O ( 1 ) which is suitable for piezoelectric energy harvesting due to its large values of piezoelectric co-efficient (d33=10 pm V−1) and spontaneous polarization (Ps=1.3 μC cm−2). Among the devices prepared with the composite films of polyvinyl alcohol (PVA) and various weight % composition of 1 , the 10 Wt % composite shows the highest output voltage of 8 V, a power density of 0.85 μW cm−2, and output current of 5 μA, which is highest for any discrete inorganic complex reported to date. 相似文献
87.
Dr. Rakesh K. Saunthwal Dr. Maria Schwarz Dr. Rajendra K. Mallick William Terry-Wright Prof. Jonathan Clayden 《Angewandte Chemie (International ed. in English)》2023,62(14):e202216758
A practical, transition metal-free method allows the enantioselective synthesis of α,α-diarylmethylamines by asymmetric α-arylation of benzylamines. Enantioselective lithiation of N′-aryl-N-benzyl-N-isopropyl ureas using a chiral lithium amide base generates a benzyllithium that undergoes an unactivated stereospecific intramolecular nucleophilic aromatic substitution to generate an α,α-diarylmethylamine in the form of its urea derivative, in up to >99 % ee. Treatment with acid induces an “azatropic shift” with retention of configuration, the product of which may be hydrolysed to the target amine. 相似文献
88.
Sudip Baguli Subham Sarkar Soumajit Nath Dr. Dibyendu Mallick Dr. Debabrata Mukherjee 《Angewandte Chemie (International ed. in English)》2023,62(47):e202312858
Azomethine ylides are typically in situ generated synthons for making N-heterocycles through cycloaddition reactions. But an offbeat aspect about them is the isomeric nature of aldiminium-based azomethine ylides and (alkyl/aryl)(amino)carbenes, interconvertible by a formal 1,3-H+ transfer. Herein, two thermally robust azomethine ylides with a N-appended picolyl sidearm are isolated, which cyclize to pyaziridines at 80 °C but unprecedentedly result N−picoCAAC-CuCl (CAAC=cyclic(alkyl)(amino)carbene) complexes when heated with CuCl at merely 60 °C. The pendant Npy, as revealed by computational analysis, plays a crucial role in this unusual 1,3-H+ shift using a deprotonation-protonation sequence, as well as in placing the CuCl at the carbenic site in tandem. The softer nature of Cu(I) is also critical. Chelating CAACs are rare and one with a N-tethered additional donor is priorly unknown. Both N-picoCAAC and pyaziridine are bidentate chelators giving highly active cationic Rh(I) catalysts for hydrosilylating unactivated olefins by Et3SiH. Notably, the pyaziridine-Rh(I) is superior than the N-picoCAAC-Rh(I) catalyst. 相似文献
89.
90.
Sett P Mishra T Chowdhury J Ghosh M Chattopadhyay S Kumar Sarkar S Kumar Mallick P 《The Journal of chemical physics》2008,128(14):144507
Detailed investigation on the vibrational and electronic spectra has been carried out in order to study various properties of 2,2'-dipyridylketone molecule in its ground and excited electronic states. To get insight into the structural and symmetry features of the molecule, Raman excitation profiles of several normal modes have been analyzed. The polarized Raman spectra in different environments along with their IR counterpart have been critically surveyed and different normal modes have been assigned. The knowledge in regard to the positions of different excited electronic states has been acquired from the study of electronic absorption spectra. All the experimental observations have been substantiated and corroborated theoretically by the quantum chemical calculation. Possibility of exciton splitting of the 1La band has been explored both from theoretical and experimental points of view. 相似文献
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