全文获取类型
收费全文 | 526篇 |
免费 | 40篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 142篇 |
金属工艺 | 6篇 |
机械仪表 | 6篇 |
建筑科学 | 12篇 |
矿业工程 | 1篇 |
能源动力 | 14篇 |
轻工业 | 83篇 |
水利工程 | 7篇 |
石油天然气 | 2篇 |
无线电 | 31篇 |
一般工业技术 | 73篇 |
冶金工业 | 120篇 |
原子能技术 | 6篇 |
自动化技术 | 61篇 |
出版年
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 10篇 |
2020年 | 9篇 |
2019年 | 16篇 |
2018年 | 25篇 |
2017年 | 19篇 |
2016年 | 18篇 |
2015年 | 12篇 |
2014年 | 18篇 |
2013年 | 41篇 |
2012年 | 24篇 |
2011年 | 29篇 |
2010年 | 23篇 |
2009年 | 19篇 |
2008年 | 17篇 |
2007年 | 24篇 |
2006年 | 15篇 |
2005年 | 22篇 |
2004年 | 11篇 |
2003年 | 13篇 |
2002年 | 9篇 |
2001年 | 11篇 |
2000年 | 4篇 |
1999年 | 11篇 |
1998年 | 34篇 |
1997年 | 25篇 |
1996年 | 15篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 9篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1986年 | 4篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1959年 | 2篇 |
1957年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有566条查询结果,搜索用时 31 毫秒
81.
Title of program: LATTICE Catalogue number: AARH Listing available from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: CDC CYBER 205; Installation: CYBERNET Data Center, Minneapolis, MN, USA (test run was executed on the system when it was being checked out) Operating system: CYBER 200 O.S. Programming language used: CYBER 200 FORTRAN High speed storage required: 65–256 K (virtual memory system) Number of bits in a word: 64 Overlay structure: none Number of magnetic tapes required: none Other peripherals used: card reader, line printer Number of cards in combined program and test deck: 662 Card punching code: CDC 相似文献
82.
Reports an error in the original article by De Soto and Liebowitz (Journal of Abnormal & Social Psychology, 1956[Nov], 53, 334-337). Some incorrectly calculated probabilities of Type II errors were given. Recalculated probabilities are given in Table 1. These are probabilities of Type II errors for 2-tail t tests of the difference between mean vocabulary scores of high and low perceivers in case of certain hypothetical true differences in various experimental conditions and groupings, as explained in the original article. The probabilities in Table 1 are substantially greater than those given earlier, but low enough that a complete absence of significant t's would be surprising if a large true difference existed. All t's obtained were nonsignificant, and the average difference was in fact in the wrong direction. It may be noted that 1-tail t tests might have been used, since the direction of the difference was hypothesized. One-tail t tests would have had lower probabilities of Type II errors than 2-tail t tests for the hypothetical true differences listed, and would also have yielded uniformly nonsignificant results. (The following abstract of this article originally appeared in record 1958-03650-001). This experiment was a replication of that of Krech and Calvin (Levels of perceptual organization and cognition. J. abnorm. soc. Psychol., 1953, 48, 394-400) using modified techniques. The correlation previously reported by Krech and Calvin between intelligence and perception, did not obtain upon replication. The data confirmed their finding that progression over trials was usually from low to high perceptual organization, but did not show a correlation between perception and stimulus-exposure time from 0.01 to 1.00 second. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
83.
Prediction of NaCl,nitrate and nitrite contents in minced meat by using a voltammetric electronic tongue and an impedimetric sensor 总被引:2,自引:0,他引:2
Roberto H. Labrador Rafael Masot Miguel Alcañiz Diana Baigts Juan Soto Ramón Martínez-Mañez Eduardo García-Breijo Luis Gil José M. Barat 《Food chemistry》2010
A method for predicting levels of sodium chloride, sodium nitrite and potassium nitrate in minced meat by using a combination of two different electrochemical methods; namely an electronic tongue (ET) based on pulse voltammetry and electrochemical impedance spectroscopy measurements is proposed here. The measurements with the voltammetric ET were carried out on both saline solutions (brines) and minced meat, whereas the impedimetric sensor was used only in minced meat. The addition of the salts was performed following an experimental design in which a system of three compounds/three levels was established. Multivariate analysis including Cross validation and Partial Least Square (PLS) techniques were applied for data management and prediction models building. A very good prediction of the concentration of chloride was achieved, whereas the prediction for the concentration of nitrate and nitrite can be considered as moderate. 相似文献
84.
Cristian A. Silva Jian lv Lu Yin Itthipon Jeerapan Gabriel Innocenzi Fernando Soto Young‐Geun Ha Joseph Wang 《Advanced functional materials》2020,30(30)
The adoption of epidermal electronics into everyday life requires new design and fabrication paradigms, transitioning away from traditional rigid, bulky electronics towards soft devices that adapt with high intimacy to the human body. Here, a new strategy is reported for fabricating achieving highly stretchable “island‐bridge” (IB) electrochemical devices based on thick‐film printing process involving merging the deterministic IB architecture with stress‐enduring composite silver (Ag) inks based on eutectic gallium‐indium particles (EGaInPs) as dynamic electrical anchors within the inside the percolated network. The fabrication of free‐standing soft Ag‐EGaInPs‐based serpentine “bridges” enables the printed microstructures to maintain mechanical and electrical properties under an extreme (≈800%) strain. Coupling these highly stretchable “bridges” with rigid multifunctional “island” electrodes allows the realization of electrochemical devices that can sustain high mechanical deformation while displaying an extremely attractive and stable electrochemical performance. The advantages and practical utility of the new printed Ag‐liquid metal‐based island‐bridge designs are discussed and illustrated using a wearable biofuel cell. Such new scalable and tunable fabrication strategy will allow to incorporate a wide range of materials into a single device towards a wide range of applications in wearable electronics. 相似文献
85.
Hangbo Zhao Sei Jin Park Brian R. Solomon Sanha Kim Dan Soto Adam T. Paxson Kripa K. Varanasi A. John Hart 《Advanced materials (Deerfield Beach, Fla.)》2019,31(14)
Many natural surfaces such as butterfly wings, beetles' backs, and rice leaves exhibit anisotropic liquid adhesion; this is of fundamental interest and is important to applications including self‐cleaning surfaces, microfluidics, and phase change energy conversion. Researchers have sought to mimic the anisotropic adhesion of butterfly wings using rigid surface textures, though natural butterfly scales are sufficiently compliant to be deflected by capillary forces exerted by drops. Here, inspired by the flexible scales of the Morpho aega butterfly wing, synthetic surfaces coated with flexible carbon nanotube (CNT) microscales with anisotropic drop adhesion properties are fabricated. The curved CNT scales are fabricated by a strain‐engineered chemical vapor deposition technique, giving ≈5000 scales of ≈10 µm thickness in a 1 cm2 area. Using various designed CNT scale arrays, it is demonstrated that the anisotropy of drop roll‐off angle is influenced by the geometry, compliance, and hydrophobicity of the scales; and a maximum roll‐off anisotropy of 6.2° is achieved. These findings are supported by a model that relates the adhesion anisotropy to the scale geometry, compliance, and wettability. The electrical conductivity and mechanical robustness of the CNTs, and the ability to fabricate complex multidirectional patterns, suggest further opportunities to create engineered synthetic scale surfaces. 相似文献
86.
Problems stemming from quantitative phase imaging from intensity measurements play a key role in many fields of physics. Techniques based on the transport of intensity equation require an estimate of the axial derivative of the intensity to invert the problem. Derivation formulas in two adjacent planes are commonly used to experimentally compute the derivative of the irradiance. Here we propose a formula that improves the estimate of the derivative by using a higher number of planes and taking the noisy nature of the measurements into account. We also establish an upper and lower limit for the estimate error and provide the distance between planes that optimizes the estimate of the derivative. 相似文献
87.
The synthesis of poly (N,N′-dimethylacrylamide-co-acrylic acd) under different feed molar ratios was carried out by radical polymerization. Both homopolymers were also synthesized to compare the metal ion binding abilities. All polymers were water-soluble and were characterized by FTIR, 1H-NMR, 13C-NMR, and TGA. The metal complexing properties for the metals Cu(II), Co(II), Ni(II), Cd(II), Zn(II), Pb(II), Hg(II), Cr(III), and Fe(III) in the aqueous phase were investigated using the liquid-phase polymer-based retention (LPR) method. The metal ion interactions with the hydrophilic polymer were determined as a function of pH and the filtration factor. According to the interaction pattern obtained, the metal ions form the most stable complexes with the copolymer poly(N,N′-dimethylacrylamide-co-acrylic acid) within the pH range 5–7. Hg(II) was not retained at all the pH ranges investigated. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 93–100, 1998 相似文献
88.
This work presents a computational matrix framework in terms of tensor signal algebra for the formulation of discrete chirp Fourier transform algorithms.These algorithms are used in this work to estimate the point target functions(impulse response functions)of multiple-input multiple-output(MIMO)synthetic aperture radar(SAR)systems.This estimation technique is being studied as an alternative to the estimation of point target functions using the discrete cross-ambiguity function for certain types of environmental surveillance applications.The tensor signal algebra is presented as a mathematics environment composed of signal spaces,finite dimensional linear operators,and special matrices where algebraic methods are used to generate these signal transforms as computational estimators.Also,the tensor signal algebra contributes to analysis,design,and implementation of parallel algorithms.An instantiation of the framework was performed by using the MATLAB Parallel Computing Toolbox,where all the algorithms presented in this paper were implemented. 相似文献
89.
90.
Quality enhancement of the abundant under‐valued crustacean,lobster krill (Munida spp.), during its chilled storage 下载免费PDF全文
Bibiana García‐Soto José M. Miranda Jorge Barros‐Velázquez Santiago P. Aubourg 《International Journal of Food Science & Technology》2015,50(3):708-716
Lobster krill (Munida genus) represents an under‐valued crustacean frequently caught on European fishing banks. In this work, its sensory, microbiological and biochemical qualities were evaluated during chilled storage. Additionally, the effects of a prestorage antimelanosic treatment consisting of soaking in sodium metabisulphite (SMB) solutions at two different concentrations (0.25% and 0.75%) were also studied. SMB prestorage treatment provided lobster specimens that still exhibited acceptable sensory quality after 10 days of storage, while control specimens were unacceptable at that time. SMB treatment also resulted in a significant (P < 0.05) inhibition of microbial growth, mainly of Enterobacteriaceae, psychrotrophes and proteolytic bacteria. Low lipid oxidation levels were observed for all batches; however, a significantly higher (P < 0.05) retention of polyunsaturated fatty acids was found in SMB‐treated lobster, especially in the 0.75% SMB batch. The results presented here open the way to the potential commercialisation of currently under‐utilised lobster krill as a chilled product. 相似文献