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121.
Bowen Yang Feng Cai Shuai Huang Prof. Dr. Haifeng Yu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):4064-4071
Imprinting nanopatterns on flexible substrates has diverse applications in advanced fabrication. However, the traditional thermal nanoimprint lithography (T-NIL) often causes shrinkage upon cooling. Here, a simple yet versatile method is introduced to fabricate multiple nanopatterns on a flexible substrate coated with an azopolymer by combining athermal nanoimprint lithography (AT-NIL) and photolithography. The azopolymer has various mechanical properties upon photoirradiation: 1) phototunable glass-transition temperatures (Tg) and concomitantly photoinduced switch from glassy plastic to viscoplastic polymer; 2) prominent modulation of viscoplasticity under light illumination at different wavelengths. Regionally selective multiple nanopatterns are conveniently fabricated, presenting angle-dependent structural color images on poly(ethylene terephthalate) (PET) substrates. The flexible, athermal and multiple nanopatterning method has the potential for on-demand fabrication of complex nanopatterns. 相似文献
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123.
A well‐balanced explicit/semi‐implicit finite element scheme for shallow water equations in drying–wetting areas
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Numerical solutions of the shallow water equations can be used to reproduce flow hydrodynamics occurring in a wide range of regions. In hydraulic engineering, the objectives include the prediction of dam break wave propagation, fluvial floods and other catastrophic flooding phenomena, the modeling of estuarine and coastal circulations, and the design and optimization of hydraulic structures. In this paper, a well‐balanced explicit and semi‐implicit finite element scheme for shallow water equations over complex domains involving wetting and drying is proposed. The governing equations are discretized by a fractional finite element method using a two‐step Taylor–Galerkin scheme. First, the intermediate increment of conserved variable is obtained explicitly neglecting the pressure gradient term. This is then corrected for the effects of pressure once the pressure increment has been obtained from the Poisson equation. In order to maintain the ‘well‐balanced’ property, the pressure gradient term and bed slope terms are incorporated into the Poisson equation. Moreover, a local bed slope modification technique is employed in drying–wetting interface treatments. The proposed model is well validated against several theoretical benchmark tests. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
124.
Precisely Controlled Multidimensional Covalent Frameworks: Polymerization of Supramolecular Colloids
Dr. Yongguang Li Shanshan Wu Lingling Zhang Xin Xu Yajun Fang Juzhen Yi Dr. Jehan Kim Dr. Bowen Shen Prof. Myongsoo Lee Dr. Liping Huang Liwei Zhang Junhui Bao Prof. Hongbing Ji Prof. Zhegang Huang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(48):21709-21713
Rapid and selective removal of micropollutants from water is important for the reuse of water resources. Despite hollow frameworks with specific functionalized porous walls for the selective adsorption based on a series of interactions, tailoring a stable shape of nanometer- and micrometer-sized architectures for the removal of specific pollutants remains a challenge. Here, exactly controlled sheets, tubes, and spherical frameworks were presented from the crosslinking of supramolecular colloids in polar solvents. The frameworks strongly depended on the architecture of original supramolecular colloids. As the entropy of colloids increased, the initial laminar framework rolled up into hollow tubules, and then further curled into hollow spheres. These shape-persistent frameworks showed unprecedented selectivity as well as specific recognition for the shape of pollutants, thus contributing to efficient pollutant separation. 相似文献
125.
Mi Ouyang Dacheng Dai Xuming Hu Yuwen Li Zhangxin Chen Bowen Tao Lina Zhang Weijun Li Yujie Dong Ru Bai Xiaojing Lv Cheng Zhang 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2269-2279
A new star-shaped structure conjugated microporous polymers, poly (2,8,14-tri[4-diphenyl-benzene]-hexaazatrinaphthylene) (PTPA-HATN), was designed and in-situ electrochemically polymerized on the surfaces of FTO electrodes with a directional alignment TiO2 nanorod array to obtain TiO2/PTPA-HATN core-shell nanocomposite films. Compared with the PTPA-HATN film, the TiO2/PTPA-HATN composite film exhibits higher optical contrast and faster response time, with contrast of 57% at 783 nm, coloring time of 3.62 s and discoloring time of 2.55 s (43%, 4.63 s and 4.77 s for PTPA-HATN film, respectively). After 400 cycles, the contrast of nanocomposite film decreased by 28%, while the PTPA-HATN film basically lost its electrochromic properties. A simple three-layer EC prototype device based on TiO2/PTPA-HATN nanocomposite film constructed with hydrogel electrolyte clearly shows color changes at different voltages. On the one hand, the formation of core-shell porous nanostructure of TiO2/PTPA-HATN composite film provides a larger ion doping/de-doping interface, shortening the average diffusion length of ions. On the other hand, the large indented polymer-nanorods contact interface makes it difficult for the polymer to detach from the electrode, thus significantly improving the cyclic stability of the composite film. 相似文献
126.
127.
Gaoxiang Liu Nikita Fedik Chalynette Martinez‐Martinez Sandra M. Ciborowski Xinxing Zhang Alexander I. Boldyrev Kit H. Bowen 《Angewandte Chemie (International ed. in English)》2020,59(23):8760-8764
We reply to the comment by S. Pan and G. Frenking who challenged our interpretation of the Na?:→BH3 dative bond in the recently synthesized NaBH3? cluster. Our conclusion remains the same as that in our original paper ( https://doi.org/10.1002/anie.201907089 and https://doi.org/10.1002/ange.201907089 ). This conclusion is additionally supported by the energetic pathways and NBO charges calculated at UCCSD and CASMP2(4,4) levels of theory. We also discussed the suitability of the Laplacian of electron density (QTAIM) and Adaptive Natural Density Partitioning (AdNDP) method for bond type assignment. It seems that AdNDP yields more sensible results. This discussion reveals that the complex realm of bonding is full of semantic inconsistencies, and we invite experimentalists and theoreticians to elaborate this topic and find solutions incorporating different views on the dative bond. 相似文献
128.
Several cobalt complexes bearing tridentate (NNN) ligands were synthesized and served as precatalysts for alkyne hydrosilylation with Ph2SiH2. For terminal alkynes, the catalyst L2 b‐CoCl2 was selected, and resulted in the corresponding α‐vinylsilanes with high (Markovnikov) regioselectivity and extensive functional‐group tolerance. For internal diaryl alkynes, the catalyst L2 c‐CoCl2 exhibited the best activity, and afforded E‐selective vinylsilanes through syn‐addition in excellent yield under mild conditions. 相似文献
129.
Herein, an arsenomolybdate, {Cu(diz)4(H2O)2}[{Cu(diz)2(H2O)2}2{As2Mo6O26}]·2H2O (diz = 1,2-diazole) (1), has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, IR, TG, XPS, PXRD, and UV–Vis-NIR. The {Cu-diz} complexes link the [As2Mo6O26]6? polyoxoanions, forming a 1-D infinite chain. The 2-D layer is constructed from 1-D chains through hydrogen bonds. Adjacent layers and free {Cu(diz)4(H2O)2} complexes are fused through hydrogen bonding to form a 3-D topological framework with symbol of {414·610·84}{4}2. Compound 1 exhibits luminescence at room temperature, excellent degradation activity for four different organic dyes (RhB, MB, MO, and AP) under UV irradiation. The photocatalytic mechanism of 1 is discussed in detail. Furthermore, the electrocatalytic activity of 1 toward hydrogen peroxide has also been studied. 相似文献
130.
Vapor deposition of CdTe from elemental cadmium and tellurium sources was studied as a function of the Cd/Te ratio, the supersaturation and the substrate temperature, in order to achieve optimum growth conditions for CdTe windows with low optical absorptivity in the infrared. A multisubstrate arrangement was designed to enable acquisition of growth data simultaneously on up to six specimens, each exposed to different growth conditions. Polycrystalline blanks up to 15 cm2 × 2 mm thick were grown at rates of 0.02-1.5 mm/h with the growth rate exhibiting sensitivity to all of the above variables. Our results show that stoichiometry (as well as free carrier concentrations) can be controlled by adjustments in the Cd/Te ratio and/or the substrate temperature. Similarly, microstructural aspects (e.g., grain and void size) are shown to exhibit strong sensitivity to variations in growth conditions. 相似文献