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51.
Hajime Shigemitsu Youhei Tani Tomoe Tamemoto Tadashi Mori Xinxi Li Yasuko Osakada Mamoru Fujitsuka Toshiyuki Kida 《Chemical science》2020,11(43):11843
The development of photocatalysts is an essential task for clean energy generation and establishing a sustainable society. This paper describes the aggregation-induced photocatalytic activity (AI-PCA) of amphiphilic rhodamines and photocatalytic functions of the supramolecular assemblies. The supramolecular assemblies consisting of amphiphilic rhodamines with octadecyl alkyl chains exhibited significant photocatalytic activity under visible light irradiation in water, while the corresponding monomeric rhodamines did not exhibit photocatalytic activity. The studies on the photocatalytic mechanism by spectroscopic and microscopic analyses clearly demonstrated the AI-PCA of the rhodamines. Moreover, the supramolecular assemblies of the rhodamines exhibited excellent photocatalytic hydrogen evolution rates (up to 5.9 mmol g−1 h−1).Simple amphiphilic rhodamines formed supramolecular assemblies and exhibited aggregation-induced photocatalytic activity and hydrogen evolution in water. 相似文献
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54.
Thieno[3,4‐c]phosphole‐4,6‐dione: A Versatile Building Block for Phosphorus‐Containing Functional π‐Conjugated Systems
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Prof. Dr. Youhei Takeda Kota Hatanaka Takuya Nishida Prof. Dr. Satoshi Minakata 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(30):10360-10364
A versatile phosphorus‐containing π‐conjugated building block, thieno[3,4‐c]phosphole‐4,6‐dione (TPHODO), has been developed. The utility of this simple but hitherto unknown building block has been demonstrated by preparing novel functional organophosphorus compounds and bandgap‐tunable conjugated polymers. 相似文献
55.
Masakazu Iwasaki Tadashi Narita Youhei Umino 《Journal of organometallic chemistry》2011,696(15-16):2763-2766
The structure of benzyllithium complexed with lithium 2–(1–pyrrolidyl)ethoxide was investigated by X-ray crystallographic analyses to afford (C4H8N–CH2CH2OLi)6·(C6H5CH2Li)2 structure of a doubly capped hexagonal prism with Ci symmetry of heavily distorted structure. The crystal structure of C4H8N–CH2CH2OLi was also examined to give the distorted hexagonal prism of hexamer with S6 symmetry. 相似文献
56.
Fully developed incompressible turbulent flow in a conical diffuser having a total divergence angle of 8° and an area ratio
of 4∶1 has been simulated by ak-ε turbulence model with high Reynolds number and adverse pressure gradient. The research has been done for pipe entry Reynolds
numbers of 1.16×105 and 2.93×105. The mean flow velocity and turbulence energy are predicted successfully and the advantage of Boundary Fit Coordinates approach
is discussed. Furthermore, thek-ε turbulence model is applied to a flow in a conical diffuser having a total divergence angle of 30° with a perforated screen.
A simplified mathematical model, where only the pressure drop is considered, has been used for describing the effect of the
perforated screen. The optimum combination of the resistance coefficient and the location of the perforated screen is predicted
for high diffuser efficiency or the uniform velocity distribution. 相似文献
57.
T. Oka T. Tabuchi S. Kawasaki J.L. Luo Guo-qing Zheng 《Journal of Physics and Chemistry of Solids》2011,72(5):497-500
We report 75As nuclear quadrupole resonance (NQR) studies on oxypnictide superconductors LaFeAsO1−xFx (x=0.08, 0.15) and LaNiAsO1−xFx (x=0, 0.06, 0.10, 0.12). In LaFeAsO0.92F0.08 (Tc=23 K), nuclear spin-lattice relaxation rate 1/T1 shows no coherence peak just below Tc and decreases with decreasing temperature accompanied by a hump structure at T∼0.4Tc, which is a characteristic of the multigap superconductivity. In the normal state, the quantity 1/T1T increases with decreasing temperature to Tc, indicating that the existence of antiferromagnetic correlation originating from its multiple electronic band structure. On the other hand, LaNiAsO1−xFx shows a clear Hebel-Slichter (coherence) peak just below Tc, evidencing that the LaNiAsO1−xFx is a BCS superconductor. In the normal state, 1/T1T is constant in the temperature range for all LaNiAsO1−xFx, which indicates electron correlations are weak. We suggest that the contrasting behavior of both superconductivity and electron correlations in LaFeAsO0.92F0.08 and LaNiAsO1−xFx between them relate to the difference of electronic band structure configuration. We also provide a possible interpretation for the pseudogap-like behavior in the normal state observed in both compounds. 相似文献
58.
Muraoka T Abe K Haga Y Nakamura T Ueno K 《Journal of the American Chemical Society》2011,133(39):15365-15367
Base-stabilized silanone complex Cp*(OC)(2)W(SiMe(3)){O═SiMes(2)(DMAP)} (2) was synthesized by the reaction of (silyl)(silylene)tungsten complex Cp*(OC)(2)W(SiMe(3))(═SiMes(2)) (1) with 1 equiv of pyridine-N-oxide (PNO) in the presence of 4-(dimethylamino)pyridine (DMAP). Further oxygenation of 2 with 3 equiv of PNO at 80 °C resulted in the formation of a W-O-Si-O-Si framework to give disiloxanoxy complex Cp*(O)(2)W{OSiMes(2)(OSiMe(3))} (3). Complex 3 was also obtained by the direct reaction of complex 1 with 4 equiv of PNO at 80 °C. 相似文献
59.
Takanori Iwasaki Shin Murakami Youhei Takeda Norimitsu Tohnai Nobuaki Kambe 《化学:亚洲杂志》2020,15(8):1349-1354
Changes in the photophysical properties of pyrene ( Py )‐octafluoronaphthalene ( OFN ) co‐crystals ( Py ? OFN ) upon mechanical stimuli are described herein. The Py ? OFN co‐crystal showed a mechano‐induced bathochromic shift in emission, and a similar tendency was observed for the 1,3,6,8‐tetramethylpyrene‐ OFN co‐crystal. These shifts are due to disruption of the microscopic molecular orientation in the co‐crystal, which allows for excimer formation. In sharp contrast to the parent Py ? OFN and methyl‐substituted Py ‐ OFN co‐crystals, no mechano‐induced bathochromic shift was observed when longer alkyl chains were introduced to the 1‐, 3‐, 6‐, and 8‐positions of the Py chromophore. This photophysical opposability against mechanical stimuli could be explained by the orthogonally oriented alkyl groups on the Py ring, which existed between two Py cores like pillars. This fixed OFN to maintain the face‐to‐face alternatively stacked structure of the co‐crystal and thus prevented the formation of the Py excimer. The pillar effect demonstrated herein provides a rational design for co‐crystalline systems that are photophysically stable against mechanical stresses. 相似文献
60.
2,6‐Diphospha‐s‐indacene‐1,3,5,7(2 H,6 H)‐tetraone: A Phosphorus Analogue of Aromatic Diimides with the Minimal Core Exhibiting High Electron‐Accepting Ability
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Dr. Youhei Takeda Takuya Nishida Prof. Dr. Satoshi Minakata 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(33):10266-10270
Phosphorus analogues of pyrromellitic diimides (PyDIs), which represent a family of privileged electron‐accepting organic compounds, have been successfully synthesized as novel electron‐accepting π‐conjugated molecules. Investigation into their physicochemical properties uncovered their prominent electron‐accepting abilities over the corresponding PyDI. Furthermore, theoretical studies revealed the significant contribution of σ*–π* hyperconjugation in stabilizing the LUMO+1. 相似文献