全文获取类型
收费全文 | 1046篇 |
免费 | 49篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 18篇 |
化学工业 | 279篇 |
金属工艺 | 15篇 |
机械仪表 | 13篇 |
建筑科学 | 31篇 |
矿业工程 | 3篇 |
能源动力 | 46篇 |
轻工业 | 104篇 |
水利工程 | 10篇 |
石油天然气 | 4篇 |
无线电 | 111篇 |
一般工业技术 | 144篇 |
冶金工业 | 52篇 |
自动化技术 | 267篇 |
出版年
2023年 | 7篇 |
2022年 | 35篇 |
2021年 | 28篇 |
2020年 | 24篇 |
2019年 | 33篇 |
2018年 | 40篇 |
2017年 | 29篇 |
2016年 | 40篇 |
2015年 | 29篇 |
2014年 | 34篇 |
2013年 | 67篇 |
2012年 | 82篇 |
2011年 | 66篇 |
2010年 | 52篇 |
2009年 | 47篇 |
2008年 | 55篇 |
2007年 | 66篇 |
2006年 | 49篇 |
2005年 | 30篇 |
2004年 | 44篇 |
2003年 | 19篇 |
2002年 | 25篇 |
2001年 | 16篇 |
2000年 | 11篇 |
1999年 | 17篇 |
1998年 | 15篇 |
1997年 | 21篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1097条查询结果,搜索用时 15 毫秒
71.
A. Mohammed Hussain Jens V.T. HøghTorben Jacobsen Nikolaos Bonanos 《International Journal of Hydrogen Energy》2012
This report concentrates on high performance anodes appropriate for SOFCs operating at low temperatures (400–600 °C). Symmetrical cells were made by screen printing of Nb-doped SrTiO3 (STN) on both sides of a dense ScYSZ electrolyte. Backbones I (36% porosity) and II (47% porosity) were obtained by sintering STN in air and reducing atmosphere, respectively. The porous microstructures were then infiltrated with Ni and Gd-doped CeO2 (CGO) precursors to incorporate the electrocatalytically active sites. The electrochemical performance of the anode was improved with the increment of Ni-CGO loadings. The gas diffusion impedance was investigated with He and N2 in H2/H2O gas mixtures and by varying the H2O content at 655 °C. This study indicated that the gas diffusion in these electrodes are influenced by Knudsen and bulk diffusion. 相似文献
72.
73.
Dimitrios Dechouniotis Nikolaos Leontiou Xenofontas Dimitropoulos Andreas Kind Spyros Denazis 《International Journal of Network Management》2009,19(6):513-526
Nowadays traffic monitoring and analysis tools provide poor information about traffic volume without giving any clear view of what the hidden rules and relationships that govern these flows are. Since the majority of flows is generated by services (web browsing, email, p2p) and most of these applications are dependent on many network assets (servers and databases) we should discover the underlying relationships of every application. We present a technique that discovers the hidden relationships among components of a network that consist of parts of specific applications. From time information and flow attributes, such as IP addresses and service ports, our method using a novel hybrid genetic algorithm produces a small set of fuzzy rules that can reveal the underlying relationships over a network without any guidance. These dependencies build a service graph which can become a useful tool for fault localization, monitoring service performance, designing changes and anomaly detection. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
74.
Claudia Loitsch Gerhard Weber Nikolaos Kaklanis Konstantinos Votis Dimitrios Tzovaras 《User Modeling and User-Adapted Interaction》2017,27(3-5):445-491
Moving between devices is omnipresent, but not for people with disabilities or those who require specific accessibility options. Setting up assistive technologies or finding settings to overcome a certain barrier can be a demanding task for people without technical skills. Context-sensitive adaptive user interfaces are advancing, although migrating access features from one device to another is very rarely addressed. In this paper, we describe the knowledge-based component of the Global Public Inclusive Infrastructure that infers how a device shall be best configured at the operating system layer, the application layer and the web layer to meet the requirements of a user including possible special needs or disabilities. In this regard, a mechanism to detect and resolve conflicting accessibility policies as well as recommending preference substitutes is a main requirement, as elaborated in this paper. As the proposed system emulates decision-making of accessibility experts, we validated the automatic deduced configurations against manual configurations of ten accessibility experts. The assessment result shows that the average matching score of the developed system is high. Thus, the proposed system can be considered capable of making precise decisions towards personalizing user interfaces based on user needs and preferences. 相似文献
75.
Murat Tiryakioğlu John Campbell Nikolaos D. Alexopoulos 《Metallurgical and Materials Transactions B》2009,40(6):802-811
Several indices are available in the literature to assess the structural quality of cast Al alloys, especially Al-7 pct Si-Mg
alloys that are based on tensile test results. Some of these indices, most notably the one developed by Drouzy et al., provide a number that necessarily does not have a physical meaning, whereas the others are a measure of what fraction of
the expected tensile performance is achieved. These indices are analyzed in depth, their similarities and shortcomings are
discussed in detail, and recommendations are made. 相似文献
76.
Vasileios Tzitzios Nikolaos Kostoglou Maria Giannouri Georgia Basina Christos Tampaxis Georgia Charalambopoulou Theodore Steriotis Kyriaki Polychronopoulou Charalambos Doumanidis Christian Mitterer Claus Rebholz 《International Journal of Hydrogen Energy》2017,42(37):23899-23907
A nanoporous metal–organic framework material, exhibiting an IRMOF-1 type crystalline structure, was prepared by following a direct solvothermal synthesis approach, using zinc nitrate and terephthalic acid as precursors and dimethylformamide as solvent, combined with supercritical CO2 activation and vacuum outgassing procedures. A series of advanced characterization methods were employed, including scanning electron microscopy, Fourier-transform infrared radiation spectroscopy and X-ray diffraction, in order to study the morphology, surface chemistry and structure of the IRMOF-1 material directly upon its synthesis. Porosity properties, such as Brunauer–Emmet–Teller (BET) specific area (~520 m2/g) and micropore volume (~0.2 cm3/g), were calculated for the activated sample based on N2 gas sorption data collected at 77 K. The H2 storage performance was preliminary assessed by low-pressure (0–1 bar) H2 gas adsorption and desorption measurements at 77 K. The activated IRMOF-1 material of this study demonstrated a fully reversible H2 sorption behavior combined with an adequate gravimetric H2 uptake relative to its BET specific area, thus achieving a value of ~1 wt.% under close-to-atmospheric pressure conditions. 相似文献
77.
Fault detection and identification for a class of continuous piecewise affine systems with unknown subsystems and partitions 下载免费PDF全文
Nikolaos Moustakis Bingyu Zhou Thuan Le Quang Simone Baldi 《International Journal of Adaptive Control and Signal Processing》2018,32(7):980-993
This paper establishes a novel online fault detection and identification strategy for a class of continuous piecewise affine (PWA) systems, namely, bimodal and trimodal PWA systems. The main contributions with respect to the state‐of‐the‐art are the recursive nature of the proposed scheme and the consideration of parametric uncertainties in both partitions and in subsystems parameters. In order to handle this situation, we recast the continuous PWA into its max‐form representation and we exploit the recursive Newton‐Gauss algorithm on a suitable cost function to derive the adaptive laws to estimate online the unknown subsystem parameters, the partitions, and the loss in control authority for the PWA model. The effectiveness of the proposed methodology is verified via simulations applied to the benchmark example of a wheeled mobile robot. 相似文献
78.
Alberto Coz Mercedes Villegas Ana Andrés Javier R. Viguri Dionissios Mantzavinos Nikolaos P. Xekoukoulotakis 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2011,86(12):1542-1547
BACKGROUND: Olive oil mill waste is a serious environmental problem in the Mediterranean basin given its particular characteristics of high organic content, seasonal and localized generation, and the type of processing involved. RESULTS: Olive mill waste from a three‐phase mill was characterized by means of total analysis, availability and mobility of the pollutants in order to help the decision‐maker about possible options for its valorization and/or disposal. Water content, loss of ignition, total organic carbon, phenol index and metals concentrations were measured to fully characterize the waste. Three leaching tests (NEN 7341, EN 12457 and UNE CEN‐TS 15364 EX) were carried out to evaluate the environmental hazard of the waste material and the leachates were characterized with respect to electric conductivity, pH, heavy metals, anions and organic pollutants (phenol index and total organic carbon) according to European waste directives. The results were compared with EU regulations for inert, non‐hazardous and hazardous waste disposal. CONCLUSION: It was found that not only organic parameters must be taken into account concerning the fate of this waste material, but also the mobility of heavy metals and anions should be studied. Furthermore, stabilization/solidification processes are recommended before landfill disposal of this kind of agro‐waste material. Copyright © 2011 Society of Chemical Industry 相似文献
79.
Skaropoulos NC Russchenberg HW 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(8):1583-1591
We use the T-matrix approach and the analytical orientation-averaging technique to formulate the problem of light scattering by an ensemble of rotationally symmetric particles in arbitrary orientation. The mathematical formulation yields analytical expressions for the elements of the ensemble-averaged scattering matrix that involve no more than four nested summations. An expansion into generalized spherical functions is used in the particular case where the scatterers are partially aligned along the direction of incidence. A computer code that implements the analytical expressions derived is publicly available on the World Wide Web at http://irctr.et.tudelft.nl/ -Skaropoulos/T-matrix.htm. 相似文献
80.
Nikolaos Kazantzis Author Vitae Author Vitae Costas Tseronis Author Vitae Author Vitae 《Automatica》2005,41(1):79-86
The present work proposes a systematic methodology for the optimal selection of controller parameters in the sense of minimizing a performance index, which is a quadratic function of the tracking error and the control effort. The performance index is calculated explicitly as an algebraic function of the controller parameters by solving Zubov's partial differential equation (PDE). Standard optimization techniques are then employed for the calculation of the optimal values of the controller parameters. The solution of Zubov's PDE is also used to estimate the closed-loop stability region for the chosen values of the controller parameters. The proposed approach is finally illustrated in a chemical reactor control problem. 相似文献