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991.
叶绿体不同浓度下光诱导延迟荧光光谱研究   总被引:8,自引:6,他引:2  
王成龙  钱隆  范多旺  王锦辉 《光子学报》2005,34(7):1028-1031
针对《光子学报》文献[1]中实验结果与已有报道相关光谱特征的显著差异,利用多种光谱学手段对不同浓度下叶绿体延迟荧光行进了研究.实验结果表明:PSⅠ反应中心叶绿素P700对PSⅡ所发685 nm成份的吸收随叶绿体浓度的增加而增强,从而导致PSⅠ发出的730 nm成份增强,而使得延迟荧光光谱中730 nm成为主峰,甚至685 nm成份的消失.该研究结果表明:叶绿体延迟荧光光谱中730 nm成份,是由PSⅠ作用中心叶绿素P700对PSⅡ中所发685 nm成份延迟荧光的重吸收,产生激发态所发出的荧光.该结论有助于延迟荧光光谱中各成份产生机理的进一步研究.  相似文献   
992.
A novel inclusion compound of [Mn(dca)2(3-nic)2]n·(3-nic)2n(1,dca = dicyanamide,3-nic = nicotinamide) has been prepared and characterized by single-crystal X-ray diffraction,elemental analysis and IR.This complex crystallizes in the triclinic system,space group P1 with a = 7.5979(8),b = 7.7128(9),c = 14.5346(17),α = 100.094(2),β = 92.444(2),γ = 116.736(2)o,V = 741.72(15) 3,Z = 1,Dc = 1.512 g/cm3,Mr = 675.55,μ = 0.507 mm-1,F(000) = 347,S = 1.023,the final R = 0.0400 and wR = 0.1010.The inclusion compound is constructed by a three-dimensional host network that consists of dca,3-nic and Mn2+ with coordination and hydrogen-bonding interactions.In the network,one-dimensional rectangular channels are formed,and the guest molecules(3-nic) are included in the channels.The guest molecules interlink with the host through strong hydrogen bonds.  相似文献   
993.
LIU  Hong-Wen LU  Wen-Guan 《结构化学》2010,(9):1416-1420
A new 2D Zn(Ⅱ) coordination polymer [Zn(HIDC)(bix)0.5]n(1) was obtained by the hydrothermal reaction of ZnCl2,imidazole-4,5-dicarboxylic acid(H3IDC) and 1,4-bis(imidazol-1-ylmethyl)-benzene(bix) with a 2:2:1 mole ratio.X-ray diffraction crystal structural analysis reveals it crystallizes in monoclinic,space group P21/n with a = 12.125(3),b = 10.541(3),c = 12.484(3) ,β = 115.834(4)°,V = 1436.0(6) 3,Mr = 338.60,Z = 4,Dc = 1.566 Mg·m-3,F(000) = 684,μ(MoKα) = 1.730 mm-1,the final R = 0.0439 and wR = 0.0888 for 2101 observed reflections with I ≥ 2σ(I).In 1,each zinc(Ⅱ) ion is five-coordinated with a slightly distorted trigonal bipy-ramidal coordination geometry,and each μ2-HIDC2-acts as a bridge to bond two neighboring Zn(Ⅱ) ions,leading to a 1D zigzag chain architecture.The adjacent zigzag chains are further linked by μ2-bix to form an infinite 2D network structure.The fluorescence spectrum of 1 exhibits intense emission at 466 nm when excited at 397 nm in solid state at room temperature.  相似文献   
994.
A dinuclear cadmium complex [Cd2(phen)2(C14H11O3)4(CH3CH2OH)]·(CH3OH)·(H2O) has been synthesized with benzilic acid and 1,10-phenanthroline by hydrothermal method.The crystal structure was determined by X-ray diffraction with crystal parameters as follows:triclinic system with space group P1,a = 1.21298(10),b = 1.32586(11),c = 2.4815(2) nm,α = 76.2630(10),β = 81.4500(10),γ = 69.1700(10)o,V = 3.6143(5) nm3,Dc = 1.438 g/cm3,Z = 1,F(000) = 1600,the final GOOF = 0.937,R = 0.0521 and wR = 0.1328.In the title complex,the dinuclear structure is defined by carboxyl oxygen atoms adopting a monodentate bridged coordination mode.The coordination environment of Cd(Ⅱ) ion is CdO4N2,giving a distorted octahedral coordination geometry.TG analysis shows that the title complex is stable under 140 ℃.  相似文献   
995.
A new 1D coordination polymer [Co(bpp)3Cl2(H2O)2]n 1 (bpp = 1,3-bis(4-pyridyl)-propane) was synthesized and characterized by elemental analysis,IR spectrum and single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system,space group Ibca with a = 16.569(9),b = 17.240(10),c = 27.087(16) ,V = 7738(8) 3,Z = 8,Dc = 1.306 g/cm3,Mr = 760.65,λ(MoKa) = 0.71073 ,μ = 0.623 mm1,F(000) = 3192,the final R = 0.0678 and wR = 0.2011. The Co(II) atom is coordinated in a slightly distorted octahedral CoN4Cl2 geometry by two Cl atoms in the axial positions,four N atoms from the two bridging bpp ligands and two pendant bpp ligands. The CoN4Cl2 octahedra are connected by the bridging bpp ligands to form a 1D neutral coordination polymer chain. The chains are linked by face-to-face π-π interactions between adjacent pendant bpp ligands to give rise to a 3D supramolecular architecture. The photoluminescent investigation indicates that the emission of 1 is attributed to ligand-centered emission. The variable-temperature magnetic susceptibility measurement shows weak antiferromagnetic behavior in the complex.  相似文献   
996.
A new dinuclear complex[Zn(dpa)(bipy)(H2O)]2(dpa=2,2'-diphenic acid,bipy=2,2'-bipyridine)1 has been hydrothermally synthesized and structurally characterized by elemental analysis,IR,fluorescence spectrum and single-crystal X-ray diffraction.The complex crystallizes in monoclinic,space group P21/c with a=10.960(2),b=9.4841(18),c=20.599(4)(A),β=104.452(3)°,V=2073.4(7)(A)3,C48H36N4O10Zn2,Mr=959.55,Dc=1.537 g/cm3,μ(MoKa)=1.225 mm-1,F(000)=984,Z=2,the final R=0.0364 and wR=0.0843 for 2788 observed reflections(I>20(I)).In the crystal structure,the zinc atom is five-coordinated with two carboxylate oxygen atoms from different dpas,one coordinated water molecule and two nitrogen atoms from bipy ligands,showing a slightly distorted triangular bipyramidal geometry.Furthermore,it exhibits a zero-dimensional network structure with a sixteen-membered ring and shows yellow photoluminescent property at room temperature.  相似文献   
997.
A new equation of state for associating fluids has recently been presented by Medeiros and Tellez-Arredondo, the Cubic-Two-State Equation of State (CTS EoS) [Ind. Eng. Chem. Res. 47 (2008) 5723]. This equation arises from the coupling of the Soave–Redlich–Kwong EoS (SRK) with an association term from a two-state association model. The CTS EoS is polynomial in volume and it is able to describe vapor pressures and molar volume of associating fluids such as water, alcohol and phenol, among others. The equation is also able to describe the liquid–vapor equilibria of their mixtures with alkanes. In this paper, the physical and thermodynamic foundations of the CTS EoS are further investigated. In order to verify its applicability for cross-associating systems, the equation was employed in the prediction of phase equilibria behavior of binary alcohol–alcohol and water–alcohol mixtures. Very good agreement between predictions and experimental phase equilibria data was obtained with very simple combining rules and only one adjustable binary parameter. No additional parameters were necessary to describe ternary systems. With the purpose of checking the model's hypothesis and limitations, the two-state association term was coupled with the hard sphere Carnahan–Starling EoS, forming the CS-TS equation and the association characteristic parameters were determined theoretically for prototype association fluids. Monte Carlo NPT simulations of such fluids were performed and the results were compared with the equation's predictions. The CS-TS was able to describe qualitatively the pvTpvT behavior of the prototype; nevertheless, it is not as accurate as those predictions obtained from the combination CS with Wertheim's association term. It seems that, when adjusting parameters of the CTS EoS to real substances, the discrepancies between the predicted and the real association contribution are dissipated among other adjustable parameters, specially on the dispersive term of the SRK equation. Finally, it is shown that CTS EoS isotherms can only have one or three real bigger roots than the co-volume for positive pressures, similar to cubic equations of state, and then it has the desirable form to describe vapor–liquid phase equilibria of associating compounds mixtures.  相似文献   
998.
以对乙酰氨基苯甲酸和2,2′-联吡啶为配体合成了一个新配合物[Cd(C9H8O3N)2(2,2′-bipy)(H2O)]2·(H2O)3。该配合物晶体属三斜晶系,空间群P1,晶胞参数:a=1.2559(3)nm,b=1.5068(3)nm,c=1.6507(3)nm,α=112.14(3)°,β=101.83(3)°,γ=93.84(3)°,V=2.7959(10)nm3,Dc=1.592g·cm-3,Z=4,μ(MoKα)=0.840mm-1,F(000)=1364,最终偏离因子R1=0.0276,wR2=0.0683。标题配合物的不对称单元由2个独立的单核结构Cd(C9H8O3N)2(2,2′-bipy)(H2O)和3个晶格水分子组成。中心镉髤离子处于六配位的变形八面体环境中。本工作测定了配合物的荧光和电化学性能。  相似文献   
999.
刘光祥  徐衡  任小明 《无机化学学报》2010,26(10):1851-1855
水热合成了一个新配合物{[Cd(BDC)(bpimb)0.5(H2O)]·H2O}n。通过元素分析、红外光谱、热重以及X-射线单晶洐射对其进行了表征.该晶体属单斜晶系,P21/c空间群。Cd髤原子通过BDC和bpimb两种配体连接成一维带状结构,带与带之间通过O-H…O和C-H…O连接成三维超分子结构。室温下配合物具有较强的荧光发射光谱。  相似文献   
1000.
合成了标题配合物Cu(Cmba)2(Mim)2(Cmba为2-氯-6-甲基苯甲酸阴离子,Mim为N-甲基咪唑),并用X射线单晶衍射仪测定了其晶体结构。晶体属单斜晶系,P21/n空间群,晶胞参数为:a=0.7389(15)nm,b=2.1379(4)nm,c=0.8150(16)nm,β=112.41(3)°,V=1.1902(4)nm3,Z=2,Dc=1.582g.cm-3。最后精修结果为:R1=0.0682,wR2=0.1740。在配合物结构中每个Cu髤原子分别与来自2个羧酸根离子中的2个氧原子、2个N-甲基咪唑分子中的2个N原子进行配位,形成了1个平面四边形结构。电化学研究显示配合物中的Cu2+/Cu+对的氧化还原是一个准可逆的过程。  相似文献   
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