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81.
82.
Ghobadi Nader Hafezi Fatemeh Naderi Sirvan Amiri Fatemeh Luna Carlos Arman Ali Shakoury Reza Ţălu Ştefan Rezaee Sahar Habibi Maryam Mardani Mohsen 《Semiconductors》2019,53(13):1751-1758
Semiconductors - The purpose of this research is to explore the properties of CoSe nanostructured thin films on glass substrates prepared by a chemical solution deposition method. Special attention... 相似文献
83.
Sisi He Yueyu Zhang Longbin Qiu Longsheng Zhang Yun Xie Jian Pan Peining Chen Bingjie Wang Xiaojie Xu Yajie Hu Cao Thang Dinh Phil De Luna Mohammad Norouzi Banis Zhiqiang Wang Tsun‐Kong Sham Xingao Gong Bo Zhang Huisheng Peng Edward H. Sargent 《Advanced materials (Deerfield Beach, Fla.)》2018,30(18)
The ability to release, as electrical energy, potential energy stored at the water:carbon interface is attractive, since water is abundant and available. However, many previous reports of such energy converters rely on either flowing water or specially designed ionic aqueous solutions. These requirements restrict practical application, particularly in environments with quiescent water. Here, a carbon‐based chemical‐to‐electricity device that transfers the chemical energy to electrical form when coming into contact with quiescent deionized water is reported. The device is built using carbon nanotube yarns, oxygen content of which is modulated using oxygen plasma‐treatment. When immersed in water, the device discharges electricity with a power density that exceeds 700 mW m?2, one order of magnitude higher than the best previously published result. X‐ray absorption and density functional theory studies support a mechanism of operation that relies on the polarization of sp2 hybridized carbon atoms. The devices are incorporated into a flexible fabric for powering personal electronic devices. 相似文献
84.
F. Pelayo García de Arquer Oleksandr S. Bushuyev Phil De Luna Cao‐Thang Dinh Ali Seifitokaldani Makhsud I. Saidaminov Chih‐Shan Tan Li Na Quan Andrew Proppe Md. Golam Kibria Shana O. Kelley David Sinton Edward H. Sargent 《Advanced materials (Deerfield Beach, Fla.)》2018,30(38)
Electrochemical reduction of CO2 is a compelling route to store renewable electricity in the form of carbon‐based fuels. Efficient electrochemical reduction of CO2 requires catalysts that combine high activity, high selectivity, and low overpotential. Extensive surface reconstruction of metal catalysts under high productivity operating conditions (high current densities, reducing potentials, and variable pH) renders the realization of tailored catalysts that maximize the exposure of the most favorable facets, the number of active sites, and the oxidation state all the more challenging. Earth‐abundant transition metals such as tin, bismuth, and lead have been proven stable and product‐specific, but exhibit limited partial current densities. Here, a strategy that employs bismuth oxyhalides as a template from which 2D bismuth‐based catalysts are derived is reported. The BiOBr‐templated catalyst exhibits a preferential exposure of highly active Bi () facets. Thereby, the CO2 reduction reaction selectivity is increased to over 90% Faradaic efficiency and simultaneously stable current densities of up to 200 mA cm?2 are achieved—more than a twofold increase in the production of the energy‐storage liquid formic acid compared to previous best Bi catalysts. 相似文献
85.
A. Stassi C. D’urso V. Baglio A. Di Blasi V. Antonucci A.S. Arico A.M. Castro Luna A. Bonesi W.E. Triaca 《Journal of Applied Electrochemistry》2006,36(10):1143-1149
A 60 wt% Pt–Fe/C and a 60 wt% Pt–Cu/C catalysts with Fe and Cu content of 5 wt% were prepared by using a combination of colloidal and incipient wetness methods; this has allowed synthesis of small nanostructured crystalline bimetallic catalysts with particle size less than 3 nm and with a suitable degree of alloying. These materials were studied in terms of structure, morphology and composition using XRD, XRF and TEM techniques. The electrocatalytic behaviour for ORR of the catalysts was investigated using the rotating disk technique and compared to that of a pure Pt catalyst with similar particle size. No improvement in performance was recorded with the Pt–Cu compared to Pt catalyst, whereas, a promoting effect in enhancing the ORR was observed for the Pt–Fe catalyst both with and without methanol in the oxygen-saturated electrolyte solution. 相似文献
86.
Stabilization of the Reductase Domain in the Catalytically Self‐Sufficient Cytochrome P450BM3 by Consensus‐Guided Mutagenesis 下载免费PDF全文
Prof. Dr. Gloria Saab‐Rincón Hanan Alwaseem Dr. Valeria Guzmán‐Luna Leticia Olvera Prof. Dr. Rudi Fasan 《Chembiochem : a European journal of chemical biology》2018,19(6):622-632
The multidomain, catalytically self‐sufficient cytochrome P450 BM‐3 from Bacillus megaterium (P450BM3) constitutes a versatile enzyme for the oxyfunctionalization of organic molecules and natural products. However, the limited stability of the diflavin reductase domain limits the utility of this enzyme for synthetic applications. In this work, a consensus‐guided mutagenesis approach was applied to enhance the thermal stability of the reductase domain of P450BM3. Upon phylogenetic analysis of a set of distantly related P450s (>38 % identity), a total of 14 amino acid substitutions were identified and evaluated in terms of their stabilizing effects relative to the wild‐type reductase domain. Recombination of the six most stabilizing mutations generated two thermostable variants featuring up to tenfold longer half‐lives at 50 °C and increased catalytic performance at elevated temperatures. Further characterization of the engineered P450BM3 variants indicated that the introduced mutations increased the thermal stability of the FAD‐binding domain and that the optimal temperature (Topt) of the enzyme had shifted from 25 to 40 °C. This work demonstrates the effectiveness of consensus mutagenesis for enhancing the stability of the reductase component of a multidomain P450. The stabilized P450BM3 variants developed here could potentially provide more robust scaffolds for the engineering of oxidation biocatalysts. 相似文献
87.
Synthesis and Evaluation of the Anticancer and Trypanocidal Activities of Boronic Tyrphostins 下载免费PDF全文
Noemi de J. Hiller Nayane A. A. e Silva Dr. Robson X. Faria Dr. André Luís A. Souza Dr. Jackson A. L. C. Resende André Borges Farias Dr. Nelilma Correia Romeiro Dr. Daniela de Luna Martins 《ChemMedChem》2018,13(14):1395-1404
Molecules containing an (cyanovinyl)arene moiety are known as tyrphostins because of their ability to inhibit proteins from the tyrosine kinase family, an interesting target for the development of anticancer and trypanocidal drugs. In the present work, (E)‐(cyanovinyl)benzeneboronic acids were synthesized by Knoevenagel condensations without the use of any catalysts in water through a simple protocol that completely avoided the use of organic solvents in the synthesis and workup process. The in vitro anticancer and trypanocidal activities of the synthesized boronic acids were also evaluated, and it was discovered that the introduction of the boronic acid functionality improved the activity of the boronic tyrphostins. In silico target fishing with the use of a chemogenomic approach suggested that tyrosine‐phosphorylation‐regulated kinase 1a (DYRK1A) was a potential target for some of the designed compounds. 相似文献
88.
An iterative trellis search technique is described for the maximum-likelihood (ML) soft decision decoding of block codes. The proposed technique derives its motivation from the fact that a given block code may be a subcode for a parent code whose associated trellis has substantially fewer edges. Through the use of list-Viterbi (1967) decoding and an iterative algorithm, the proposed technique allows for the use of a trellis for the parent code in the ML decoding of the desired subcode. Complexity and performance analyses, as well as details of potential implementations, indicate a substantial reduction in decoding complexity for linear block codes of practical length while achieving ML or near-ML soft decision performance 相似文献
89.
90.
The binding ability of poly(4‐vinylpyridine) hydrochloride resin for Cu(II), Cd(II), Zn(II), Hg(II), Pb(II), Cr(III), and U(VI) was investigated. All these ions, except Hg(II), could be not removed from aqueous solutions under the same conditions. The selective sorption of Hg(II) from mixtures of ions was observed. The elution of Hg(II) bound to the resin was also investigated using various concentrations of nitric acid and perchloric acid. Due to rapid complexation, a high mercury ion‐binding capacity, high selectivity, and ease of regenerability, the resin can be useful for the removal and recovery of mercury ions from aqueous solutions. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1557–1562, 1999 相似文献