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91.
For target tracking applications, wireless sensor nodes provide accurate information since they can be deployed and operated near the phenomenon. These sensing devices have the opportunity of collaboration among themselves to improve the target localization and tracking accuracies. An energy-efficient collaborative target tracking paradigm is developed for wireless sensor networks (WSNs). A mutual-information-based sensor selection (MISS) algorithm is adopted for participation in the fusion process. MISS allows the sensor nodes with the highest mutual information about the target state to transmit data so that the energy consumption is reduced while the desired target position estimation accuracy is met. In addition, a novel approach to energy savings in WSNs is devised in the information-controlled transmission power (ICTP) adjustment, where nodes with more information use higher transmission powers than those that are less informative to share their target state information with the neighboring nodes. Simulations demonstrate the performance gains offered by MISS and ICTP in terms of power consumption and target localization accuracy. 相似文献
92.
Wang D Xin HL Yu Y Wang H Rus E Muller DA Abruña HD 《Journal of the American Chemical Society》2010,132(50):17664-17666
A simple method for the preparation of PdCo@Pd core-shell nanoparticles supported on carbon based on an adsorbate-induced surface segregation effect has been developed. The stability of these PdCo@Pd nanoparticles and their electrocatalytic activity for the oxygen reduction reaction (ORR) were enhanced by decoration with a small amount of Pt deposited via a spontaneous displacement reaction. The facile method described herein is suitable for large-scale, lower-cost production and significantly lowers the Pt loading and thus the cost. The as-prepared PdCo@Pd and Pd-decorated PdCo@Pd nanocatalysts have a higher methanol tolerance than Pt/C in the ORR and are promising cathode catalysts for fuel cell applications. 相似文献
93.
Xuefei Xu Habib Ullah Muhammad Humayun Linfeng Li Xia Zhang Mohamed Bououdina Damien P. Debecker Kaifu Huo Deli Wang Chundong Wang 《Advanced functional materials》2023,33(44):2303986
Constructing multiple heterogeneous structures allows for improving the electrocatalytic activity of NiO by incorporating multiple active sites. Unfortunately, the poor conductivity of NiO makes efficient charge transfer within the heterogeneous structures difficult, thereby inhibiting the improvement of its intrinsic activity. Herein, F-doped NiO/Ni@C heterogeneous catalyst (F-NiO/Ni@C) is fabricated via a new organic-inorganic hybrid approach, showing both advanced hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) activity. The targeted F-doping increases electron delocalization, and facilitates electron transfer from Ni to NiO at the nano-interfaces. This interphase synergy provides ready-to-use F-NiO active sites, allowing F-NiO/Ni@C to achieve optimum H* adsorption Gibbs free energy for HER and a lower energy barrier for UOR. As a result, the as-configured F-NiO/Ni@C || F-NiO/Ni@C cell requires an ultra-low cell voltage of 1.37 V to achieve 10 mA cm−2 in alkaline media (with 0.3 M urea), outperforming the state-of-the-art benchmark Pt/C|| RuO2 cell (1.45 V). This study reveals the positive impact of anion doping on interphase synergy and provides useful guidelines for designing monometallic catalysts for UOR as well as hydrogen generation. 相似文献
94.
Jseph Deli Pter Mlnar Gyula Tth Andreas Baumeler Conrad Hans Eugster 《Helvetica chimica acta》1991,74(4):819-824
Cycloviolaxanthin (= (3S,5R,6R,3′S,5′R,6′R)-3.6:3′,6′-Diepoxy-5,6,5′,6′-tetrahydro-β,β-carotene-5,5′-diol), a Novel Carotenoid from Red Paprika (Capsicum annuum) From red paprika (Capsicum annuum var. longum nigrum) cycloviolaxanthin was isolated as a minor carotenoid and, based on spectral data, assigned the symmetrical structure 8 . 相似文献
95.
A novel Zn(II) ions imprinted poly (2-hydroxyethyl Methacrylate-N-methacryloyl-(L)-histidine methyl ester) poly(HEMAH) surface plasmon resonance (SPR) nanosensor were designed for detection of Zn(II) ions in aqueous solution and artificial plasma providing a low cost, rapid and reliable results compared to other techniques such as atomic absorption spectroscopy, inductively coupled plasma-mass spectrometer, X-ray fluorescence with synchrotron radiation. Zn(II) ions imprinted nanofilm on the SPR chip surface was synthesized by bulk polymerization. Characterization of Zn(II) ions imprinted nanosensor was performed by contact angle measurement, atomic force microscopy (AFM), ellipsometry and Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR). Designed nanosensor was applied for selective detection of Zn(II) ions in aqueous solution within the range of 0.5–1.0?µg/mL. The limit of detection (LOD) and limit of quantification (LOQ) were calculated as 0.19 and 0.64?ng/mL, respectively. Association kinetics analysis, Scatchard, Langmuir, Freundlich, Langmuir–Freundlich, Tempkin and Dubinin-Radushkevich isotherms were analyzed to the experimental data in order to identify the adsorption behavior. The selectivity of the SPR nanosensor was examined by using competitive metal ions such as Cd(II), Cu(II), Pb(II), and Fe(II). To evaluate the imprinting effect of Zn(II) ions imprinted (MIP) and non-imprinted (NIP) nanosensor was also prepared as the control. Repeatability of the response signal was tested by four times adsorption–desorption–regeneration cycle. 相似文献
96.
Pter Molnr Jzsef Deli Erzsbet sz Ferenc Zsila Mikls Simonyi Gyula Tth 《Helvetica chimica acta》2004,87(8):2159-2168
Circular dichroism (CD) spectroscopy was used to distinguish between the isomeric (all‐E)‐configured 3′‐epilutein ( 2 ) and 6′‐epilutein ( 8 ) to establish the absolute configuration of epilutein samples of different (natural and semisynthetic) origin, including samples of 2 obtained from thermally processed sorrel. Thus, the CD data of lutein ( 1 ) and epilutein samples ( 2 ) were compared. Our results unambiguously confirmed the (3R,3′S,6′R)‐configuration of all epilutein samples. Compound 2 was thoroughly characterized, and its 13C‐NMR data are published herewith for the first time. 相似文献
97.
How a new realistic mobility model can affect the relative performance of a mobile networking scheme
The validity of the mobility model used to evaluate a cellular network determines the validity of the evaluation. In the literature, unrealistic assumptions on mobility are exercised for the sake of simplicity. In this paper, we present a novel mobility model which is realistic in the sense that it captures the moving‐in‐groups, conscious traveling and inertial behaviours of the subscribers while respecting the non‐pass‐through feature of structures like households and preserving the autonomy of the subscribers. The mobility and call patterns of the subscribers are determined according to the locus of the subscriber over a real map. Thus, our model allows the subscribers to leave home or arrive home, walk or drive in the streets, get on the highways at specific entry points together with numerous hot and blind spots in the terrain, like city centers and lakes. The call pattern of a subscriber is affected by the type of structure he is in. The model can work on real maps to simulate the mobility patterns in real life. We have evaluated the proposed model against the well‐known way point mobility model. We also analyzed the effect of the mobility model on systems with and without guard channels. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
98.
应用原子分子反应静力学原理导出LaH分子的电子状态和可能的离解极限,考虑相对论紧致有效势RCEP(RelativisticCompactEffectivePotential)近似下,用QCISD方法计算了LaH分子基态X1∑+的平衡几何Re和离解能De为2.125A和2.623eV,并在计算出来的一系列单点势能基础上,用正规方程组拟合Murrell-Sorbie(M-S)势能函数,得到相应态的解析势能函数,由此计算对应的光谱参数,其Be、ae、ωe和ωexe的理论值,分别为:3.7333、0.0723、1461.73和21.383cm-1. 相似文献
99.
混合模糊系统,即通过调控参数将Mamdani和T-S合并建立的一种新型系统模型.混合模糊系统不仅能保持各自模糊系统的优良特性,还可大大缩减系统内部的模糊规则总数.为避免因增加输入变量引发高维混合模糊系统规则爆炸,基于混合模糊系统的分层表示,给出了分层混合模糊系统对连续函数的逼近算法.对比发现,高维分层混合模糊系统的规则总数可被大幅度削减.此外,通过实例模拟了一个三维混合模糊系统分层后的实际输出,并用统计学的t-假设检验方法检验了该分层混合模糊系统的逼近性能. 相似文献
100.
Satellite networks are used as backup networks to the terrestrial communication systems. In this work, we tried to find a
routing strategy over dynamic satellite systems to better utilize the capacity of the network. The satellite networks are
not affected by natural disasters, therefore they can be used widely during and after disasters. The Minimum Flow Maximum
Residual (MFMR) routing algorithm over the Routing Set boundaries is proposed in order to better utilize the capacity of the
system by distributing the load over the shortest path alternatives of the system. We assumed the satellite network as having
finite states and formulated the problem by using Finite State Automation concept along with earth-fixed cell strategy by
using a virtual satellite network model. The routing problem in satellite networks is previously studied in the literature
and it is conjectured that the problem is NP-Hard. The online and offline problems are stated and the MFMR algorithm is described
in detail. The algorithm is compared with alternatives by simulating the network on Opnet Modeler. Finally, the performance
analysis of different scenarios is given in this work.
Roy Kucukates received his BS, MS and PhD degrees in computer engineering from Bogazici University, Istanbul, in 1993, 1995 and 2002, respectively.
He worked as teaching assistant in Bogazici University between 1993 and 1995. Currently, he is a part time instructor in the
Computer Engineering Department of Koc University and Dogus University. He is the co-founder and manager of Gordion Bilgi
Hizmet Ltd Sti. LEO satellite networks, wireless networks, simulation and performance evaluationl, routing protocols can be
stated among his research areas.
Cem Ersoy received his BS and MS degrees in electrical engineering from Bogazici University, Istanbul, in 1984 and 1986, respectively.
He worked as an R&D engineer in NETAS A.S. between 1984 and 1986. He received his PhD in electrical engineering from Polytechnic
University, Brooklyn, New York in 1992. Currently, he is a professor and department head in the Computer Engineering Department
of Bogazici University. His research interests include performance evaluation and topological design of communication networks,
wireless communications and mobile applications. Wireless sensor networks. Dr. Ersoy is a Senior Member of IEEE. 相似文献