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71.
诺氟沙星–铜(Ⅱ)-吡啶衍生物配合物的合成、表征及生物活性 总被引:1,自引:1,他引:0
诺氟沙星(NFA)(图1)(1-乙基-6-氟-1,4-二氢-4-氧代-7-(1-哌嗪基)-3-喹啉羧酸)是一种典型的喹诺酮类抗菌化合物,主要通过抑制DNA旋转酶和拓扑异构酶Ⅱ使脱氧核糖核酸、核糖核酸及蛋白质的合成受到干扰,使细胞不能再进行分裂,而起杀菌作用,具有广谱抗菌性[1]. 相似文献
72.
Calzolari A Alexandre SS Zamora F Di Felice R 《Journal of the American Chemical Society》2008,130(16):5552-5562
We present an ab initio study of the structural and electronic properties of the halogen-bridged MMX single polymer [Pt2(CH3CS2)4I]n and of various possible modifications of its sequence, in the framework of density functional theory. The computed band structure of the infinite regular polymer reveals a net metallic character; this evidence is compatible with the outcome of recent measurements done in the solid phase at room temperature. By taking the regular [Pt2(CH3CS2)4I]n polymer as our reference system, we analyzed the origin and the robustness of the metallic state along the chain with respect to a large set of geometrical and chemical perturbations of the subunits. In particular, we considered partial substitutions of the metal, halide, and dithiocarboxylate ligand subunits, as well as structural strain, defects, and magnetic effects. Our results demonstrate that the metallic character of single MMX chains is very resistant to a wide range of possible distortions that can occur in reality. 相似文献
73.
Delgado S Sanz Miguel PJ Priego JL Jiménez-Aparicio R Gómez-García CJ Zamora F 《Inorganic chemistry》2008,47(20):9128-9130
We report on a novel highly semiconducting 1D coordination polymer architecture obtained by the reaction of a Cu(II) salt with 2,2'-dipyridyldisulfide under microwave solvothermal conditions. This reaction proceeds with an unusual C-S and S-S bond cleavage of the 2,2'-dipyridyldisulfide ligand. The unprecedented architecture of this coordination polymer consists of a 1D chain formed by the assembling of Cu9 cluster cages. The electrical conductivity behavior of this novel material suggests new perspectives for the use of coordination polymers as electrical conducting materials. 相似文献
74.
Guijarro A Castillo O Calzolari A Sanz Miguel PJ Gómez-García CJ di Felice R Zamora F 《Inorganic chemistry》2008,47(21):9736-9738
Three new compounds of formula [Pt2(SSCR)4] (R = CH3, (CH2)4CH3, cyclohexyl) have been prepared and characterized by X-ray diffraction. Their crystal structures consist of one-dimensional linear chains formed by stacking of the dimetallic complexes in which the alkyl group on the dithioacetate modulates the intermetallic distances between dimetallic entities. Direct current electrical conductivity studies show that crystals of the three compounds behave as semiconductors and their conductivity values are directly connected to the intermolecular metal-to-metal distances. These experimental results are supported by density functional theory calculations. 相似文献
75.
单重态氧化学VIII.类卟啉稀土配合物光敏化产生单重态氧的ESR研究 总被引:1,自引:0,他引:1
用电子自旋共振(ESR)方法研究类卟啉稀土配合物([CO2H-APPC)Gd]Cl2)光敏产生单重态氧的II型机制。利用2,2, 6, 6-四甲基哌啶(TEMP)对单重态氧的捕捉, 测定所生成的氮氧自由基的ESR信号, 经加NaN3和CD3OD的实验, 证实了([CO2H-APPC)Gd]Cl2)光敏作用可有效地产生单重态氧, 并观察到在实验所用的浓度范围内, 随着光敏剂浓度加大, 生成的单重态氧也增加, 同时比较了几种不同稀土离子配合物产生单重态氧的差别。结合氧的消耗和氮氧自由基的ESR线宽变化对氧浓度的依赖性, 证明了类卟啉稀土配合物光敏化生成单态氧的II型反应在光动力光疗中起关键作用。 相似文献
76.
A Branch and Contract Algorithm for Problems with Concave Univariate, Bilinear and Linear Fractional Terms 总被引:1,自引:0,他引:1
A new deterministic branch and bound algorithm is presented in this paper for the global optimization of continuous problems that involve concave univariate, bilinear and linear fractional terms. The proposed algorithm, the branch and contract algorithm, relies on the use of a bounds-contraction subproblem that aims at reducing the size of the search region by eliminating portions of the domain in which the objective function takes only values above a known upper bound. The solution of contraction subproblems at selected branch and bound nodes is performed within a finite contraction operation that helps reducing the total number of nodes in the branch and bound solution tree. The use of the proposed algorithm is illustrated with several numerical examples. 相似文献
77.
78.
乐碧宏 《宁波大学学报(理工版)》2005,18(1):122-125
证券风险的计量准确与否,是证券组合理论能否有效运用的前提,在现有研究成果的基础上,结合我国证券市场的特点,选取“流通市值”作为影响我国证券风险的第二个因素,建立了证券风险计量模型,并使用统计软件对模型的适用性进行了检验. 相似文献
79.
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