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661.
A series of segmented poly(urethane-urea)s containing 1,3,5 triazine in the hard block and hexamethylene spacers in the soft block was prepared. The hard to soft segment ratio was varied systematically, to afford a series of polymers in which the chromophore concentration varied from 4.2% to 18.1%. Although triazine emission is located in the UV region, the films with higher content of the chromophore emitted a visible blue light (425 nm) when excited at the very red-edge of the absorption band. The photophysical properties of the materials were strongly dependent on the relative amount of triazine moieties along the main chain. Isolated moieties emit in copolymers with small amount of triazine groups, indicating that even though in solid state, these moieties tend to be apart. Two photophysical consequences were observed when the amount of triazine increases: there is some energy transfer process involving isolated moieties with consequent decrease of the lifetime and an additional red-edge emission attributed to aggregated lumophores. The mono-exponential decay observed for the isolated form is substituted by a bi-exponential decay of the aggregated species. The materials were not strong emitters, but since the N-containing triazine moieties are good electron transport groups, the polymers have potential application as electron transport enhancers in various applications. 相似文献
662.
Recent applications of 2,4,6-trichloro-1,3,5-triazine and its derivatives in organic synthesis 总被引:2,自引:0,他引:2
Grzegorz Blotny Author Vitae 《Tetrahedron》2006,62(41):9507-9522
663.
664.
V. G. Kharchenko N. V. Pchelintseva L. I. Markova O. V. Fedotova 《Chemistry of Heterocyclic Compounds》2000,36(9):1007-1025
Literature and characteristic experimental data correlated in the review concern the intramolecular cyclization by various means of substituted 1,5-diketones of the acyclic, semi-, and bicyclic series, proceeding to the formation of oxygen-containing heterocycles, such as pyrans, pyrylium salts, di- and tetrahydrofurans, and their condensed analogs, aroylfurans etc. 相似文献
665.
666.
667.
稀土配合物RE(TPTZ)Cl_3的合成、表征及荧光性能研究 总被引:1,自引:0,他引:1
首次以2,4,6-三吡啶基三嗪(TPTZ)与Sm, Eu, Tb和Dy氯化物反应,合成四种单一稀土配合物以及Tb分别1∶1掺Gd, Y, La的三种异核配合物。经元素分析、稀土络合滴定、摩尔电导率、红外光谱、紫外光谱和差热-热重测定表明,配合物的组成分别为RE(TPTZ)Cl3·3H2O(RE=Sm, Eu, Tb, Dy)和Tb0.5Ln0.5(TPTZ)Cl3·3H2O(Ln=Gd, Y, La);TPTZ作为三齿配体与稀土离子配位,即中心环提供一个N原子,两个吡啶环分别提供一个N原子;配合物中3个水分子与稀土离子配位,1个Cl-在外界,2个在内界,为1∶1型电解质;配合物内外界可能为[RE(TPTZ)(H2O)3Cl2] Cl,稀土离子的配位数为8。配合物的荧光光谱测试表明,四种单一稀土配合物中,Tb配合物发光最强;三种1∶1掺杂异核Tb配合物荧光强度大于纯Tb配合物,表明Y3+, La3+和Gd3+都可以敏化Tb3+的发光,其中Gd3+的敏化作用最强,Y3+次之,La3+最差。 相似文献
668.
2-Anilino-6-chloro-4-methoxy-1,3,5-triazine was synthesized and studied by dynamic NMR. The activation parameters of hindered internal rotation in unsymmetrically substituted arylamino-sym-triazine were determined for the first time. It was found that a sterically more hindered rotational isomer is thermodynamically more stable in this compound (slow-exchange NOE data). 相似文献
669.
The bromo‐substituted aromatic dicarboxylic acid 5‐amino‐2,4,6‐tribromoisophthalic acid (H2ATBIP), in the presence of the N‐donor flexible bipyridyl‐type ligands 1,3‐bis(pyridin‐4‐yl)propane (bpp) and N,N′‐bis(pyridin‐4‐ylmethyl)oxalamide (4‐bpme) and ZnII ions, was used as an O‐donor ligand to assemble two novel luminescent metal–organic frameworks (MOFs), namely poly[[(μ‐5‐amino‐2,4,6‐tribromoisophthalato‐κ2O1:O3)[μ‐1,3‐bis(pyridin‐4‐yl)propane‐κ2N:N′]zinc(II)] dimethylformamide monosolvate], {[Zn(C8H2Br3NO4)(C13H14N2)]·C3H7NO}n, ( 1 ), and poly[[(μ‐5‐amino‐2,4,6‐tribromoisophthalato‐κ2O1:O3)diaqua[μ‐N,N′‐bis(pyridin‐4‐ylmethyl)oxalamide‐κ2N:N′]zinc(II)] monohydrate], {[Zn(C8H2Br3NO4)(C14H14N4O2)(H2O)2]·H2O}n, ( 2 ), using the solution evaporation method. Both ( 1 ) and ( 2 ) were characterized by FT–IR spectroscopy, elemental analysis (EA), solid‐state diffuse‐reflectance UV–Vis spectroscopy, and powder and single‐crystal X‐ray diffraction analysis. Complex ( 1 ) shows a two‐dimensional (2D) corrugated layer simplified as a 2D (4,4) topological network. The supramolecular interactions (π–π stacking, hydrogen bonding and C—Br…Br halogen bonding) play significant roles in the formation of an extended three‐dimensional (3D) supramolecular network of ( 1 ). Complex ( 2 ) crystallizes in the chiral space group P212121 and exhibits a novel 3D homochiral framework, showing a diamond‐like topology with Schläfli symbol 66. The homochirality of ( 2 ) is further confirmed by the solid‐state circular dichroism (CD) spectrum. The second harmonic generation (SHG) property of ( 2 ) was also investigated. The hydrogen and C—Br…Br/O halogen bonding further stabilize the framework of ( 2 ). The central ZnII ions in ( 1 ) and ( 2 ) show tetrahedral and octahedral coordination geometries, respectively. The coordinated and uncoordinated water molecules in ( 2 ) could be removed selectively upon heating. Most importantly, ( 1 ) and ( 2 ) show rapid and highly sensitive sensing for a large pool of nitroaromatic explosives (NAEs). 相似文献
670.
Ya-Qian Zhang Vladislav A. Blatov Xiu-Xiu Lv Ding-Yi Tang Lin-Lu Qian Ke Li Bao-Long Li 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(7):960-968
Coordination polymers (CPs) have been widely studied because of their diverse and adjustable topologies and wide‐ranging applications in luminescence, chemical sensors, magnetism, photocatalysis, gas adsorption and separation. In the present work, two coordination polymers, namely poly[(μ5‐benzene‐1,3,5‐tricarboxylato‐κ6O1:O1′:O3:O3:O5,O5′){μ3‐1,3‐bis[(1,2,4‐triazol‐4‐yl)methyl]benzene‐κ3N:N′:N′′}di‐μ3‐hydroxido‐dicobalt(II)], [Co2(C9H3O6)(OH)(C12H12N6)]n or [Co2(btc)(OH)(mtrb)]n, (1), and poly[[diaquabis(μ3‐benzene‐1,3,5‐tricarboxylato‐κ3O1:O3:O5)bis{μ3‐1,3‐bis[(1,2,4‐triazol‐4‐yl)methyl]benzene‐κ3N:N′:N′′}tetra‐μ3‐hydroxido‐tetracopper(II)] monohydrate], {[Cu4(C9H3O6)2(OH)2(C12H12N6)2(H2O)2]·H2O}n or {[Cu4(btc)2(OH)2(mtrb)2(H2O)2]·H2O}n, (2), were synthesized by the hydrothermal method using 1,3‐bis[(1,2,4‐triazol‐4‐yl)methyl]benzene (mtrb) and benzene‐1,3,5‐tricarboxylate (btc3?). CP (1) exhibits a (3,8)‐coordinated three‐dimensional (3D) network of the 3,8T38 topological type, with a point symbol of {4,5,6}2{42·56·616·72·82}, based on the tetranuclear hydroxide cobalt(II) cluster [Co4(μ3‐OH)2]. CP (2) shows a (3,8)‐coordinated tfz‐d topology, with a point symbol of {43}2{46·618·84}, based on the tetranuclear hydroxide copper(II) cluster [Cu4(μ3‐OH)2]. The different (3,8)‐coordinated 3D networks based on tetranuclear hydroxide–metal clusters of (1) and (2) are controlled by the different central metal ions [CoII for (1) and CuII for (2)]. The thermal stabilities and solid‐state optical diffuse‐reflection spectra were measured. The energy band gaps (Eg) obtained for (1) and (2) were 2.72 and 2.29 eV, respectively. CPs (1) and (2) exhibit good photocatalytic degradation of the organic dyes methylene blue (MB) and rhodamine B (RhB) under visible‐light irradiation. 相似文献