全文获取类型
收费全文 | 5000篇 |
免费 | 270篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 34篇 |
综合类 | 4篇 |
化学工业 | 1012篇 |
金属工艺 | 79篇 |
机械仪表 | 81篇 |
建筑科学 | 349篇 |
矿业工程 | 10篇 |
能源动力 | 207篇 |
轻工业 | 898篇 |
水利工程 | 31篇 |
石油天然气 | 10篇 |
无线电 | 237篇 |
一般工业技术 | 919篇 |
冶金工业 | 595篇 |
原子能技术 | 21篇 |
自动化技术 | 789篇 |
出版年
2023年 | 51篇 |
2022年 | 41篇 |
2021年 | 91篇 |
2020年 | 75篇 |
2019年 | 102篇 |
2018年 | 187篇 |
2017年 | 190篇 |
2016年 | 190篇 |
2015年 | 166篇 |
2014年 | 189篇 |
2013年 | 347篇 |
2012年 | 281篇 |
2011年 | 329篇 |
2010年 | 252篇 |
2009年 | 206篇 |
2008年 | 239篇 |
2007年 | 253篇 |
2006年 | 236篇 |
2005年 | 145篇 |
2004年 | 134篇 |
2003年 | 146篇 |
2002年 | 124篇 |
2001年 | 89篇 |
2000年 | 85篇 |
1999年 | 85篇 |
1998年 | 200篇 |
1997年 | 121篇 |
1996年 | 102篇 |
1995年 | 66篇 |
1994年 | 51篇 |
1993年 | 52篇 |
1992年 | 28篇 |
1991年 | 25篇 |
1990年 | 21篇 |
1989年 | 21篇 |
1987年 | 17篇 |
1986年 | 17篇 |
1985年 | 26篇 |
1984年 | 34篇 |
1983年 | 26篇 |
1982年 | 17篇 |
1981年 | 24篇 |
1980年 | 27篇 |
1979年 | 17篇 |
1978年 | 11篇 |
1977年 | 26篇 |
1976年 | 31篇 |
1975年 | 12篇 |
1974年 | 14篇 |
1973年 | 15篇 |
排序方式: 共有5276条查询结果,搜索用时 15 毫秒
81.
Jakob Kjøbsted Huusom Niels Kjølstad Poulsen Sten Bay Jørgensen 《Journal of Process Control》2009,19(4):570-578
Iterative Feedback Tuning constitutes an attractive control loop tuning method for processes in the absence of an accurate process model. It is a purely data driven approach aiming at optimizing the closed loop performance. The standard formulation ensures an unbiased estimate of the loop performance cost function gradient with respect to the control parameters. This gradient is important in a search algorithm. The extension presented in this paper further ensures informative data to improve the convergence properties of the method and hence reduce the total number of required plant experiments especially when tuning for disturbance rejection. Informative data is achieved through application of an external probing signal in the tuning algorithm. The probing signal is designed based on a constrained optimization which utilizes an approximate black box model of the process. This model estimate is further used to guarantee nominal stability and to improve the parameter update using a line search algorithm for determining the iteration step size. The proposed algorithm is compared to the classical formulation in a simulation study of a disturbance rejection problem. This type of problem is notoriously difficult for Iterative Feedback Tuning due to the lack of excitation from the reference. 相似文献
82.
Øystein Vedaa Anette Harris Bjørn Bjorvatn Siri Waage Børge Sivertsen Philip Tucker 《Ergonomics》2016,59(1):1-14
A systematic literature search was carried out to investigate the relationship between quick returns (i.e. 11.0 hours or less between two consecutive shifts) and outcome measures of health, sleep, functional ability and work–life balance. A total of 22 studies published in 21 articles were included. Three types of quick returns were differentiated (from evening to morning/day, night to evening, morning/day to night shifts) where sleep duration and sleepiness appeared to be differently affected depending on which shifts the quick returns occurred between. There were some indications of detrimental effects of quick returns on proximate problems (e.g. sleep, sleepiness and fatigue), although the evidence of associations with more chronic outcome measures (physical and mental health and work–life balance) was inconclusive.
Practitioner Summary: Modern societies are dependent on people working shifts. This study systematically reviews literature on the consequences of quick returns (11.0 hours or less between two shifts). Quick returns have detrimental effects on acute health problems. However, the evidence regarding effects on chronic health is inconclusive. 相似文献
83.
R.G. Raidou O. Casares‐Magaz L.P. Muren U.A. van der Heide J. Rørvik M. Breeuwer A. Vilanova 《Computer Graphics Forum》2016,35(3):231-240
In radiotherapy, tumors are irradiated with a high dose, while surrounding healthy tissues are spared. To quantify the probability that a tumor is effectively treated with a given dose, statistical models were built and employed in clinical research. These are called tumor control probability (TCP) models. Recently, TCP models started incorporating additional information from imaging modalities. In this way, patient‐specific properties of tumor tissues are included, improving the radiobiological accuracy of models. Yet, the employed imaging modalities are subject to uncertainties with significant impact on the modeling outcome, while the models are sensitive to a number of parameter assumptions. Currently, uncertainty and parameter sensitivity are not incorporated in the analysis, due to time and resource constraints. To this end, we propose a visual tool that enables clinical researchers working on TCP modeling, to explore the information provided by their models, to discover new knowledge and to confirm or generate hypotheses within their data. Our approach incorporates the following four main components: (1) It supports the exploration of uncertainty and its effect on TCP models; (2) It facilitates parameter sensitivity analysis to common assumptions; (3) It enables the identification of inter‐patient response variability; (4) It allows starting the analysis from the desired treatment outcome, to identify treatment strategies that achieve it. We conducted an evaluation with nine clinical researchers. All participants agreed that the proposed visual tool provides better understanding and new opportunities for the exploration and analysis of TCP modeling. 相似文献
84.
ABSTRACTAutomated detection and recognition of faces have been implemented in a broad range of media environments. Following that development, what concerns us in this article is the analysis of emotions from facial expressions using computer-based systems, in relation to which we critically investigate the use of theories of basic emotions. We explore in depth the company Affectiva’s attempts to translate, represent and schematize human emotions, as they raise a variety of problems and issues of uncertainty. We analyse the uncertainties concerning the processing of the human face ‘as image’ due to issues concerning temporality and static images as well as polyphony and modulations of the spectrum of expressions. One of our key arguments concerns the temporal character of human emotions, and we address how algorithmically regulated protocols of discretization may be said to prompt specific patterns of emotional responses and expressions based on an ideal of eliminating uncertainty. Through discussions via art pieces by Lauren McCarthy and Kyle McDonald, we question what happens when the protocols of computer systems start to perform aspects of emotional labour for us, making judgments by predicting adequate emotional responses based on the use of the strict metrics criticized in the article. 相似文献
85.
86.
Huth J Buchholz M Kraus JM Mølhave K Gradinaru C v Wichert G Gress TM Neumann H Kestler HA 《Computer methods and programs in biomedicine》2011,104(2):227-234
The direct observation of cells over time using time-lapse microscopy can provide deep insights into many important biological processes. Reliable analyses of motility, proliferation, invasive potential or mortality of cells are essential to many studies involving live cell imaging and can aid in biomarker discovery and diagnostic decisions. Given the vast amount of image- and time-series data produced by modern microscopes, automated analysis is a key feature to capitalize the potential of time-lapse imaging devices. To provide fast and reproducible analyses of multiple aspects of cell behaviour, we developed TimeLapseAnalyzer. Apart from general purpose image enhancements and segmentation procedures, this extensible, self-contained, modular cross-platform package provides dedicated modalities for fast and reliable analysis of multi-target cell tracking, scratch wound healing analysis, cell counting and tube formation analysis in high throughput screening of live-cell experiments. TimeLapseAnalyzer is freely available (MATLAB, Open Source) at http://www.informatik.uni-ulm.de/ni/mitarbeiter/HKestler/tla. 相似文献
87.
Nikolaj S. Bjørner Anca Browne Michael A. Colón Bernd Finkbeiner Zohar Manna Henny B. Sipma Tomás E. Uribe 《Formal Methods in System Design》2000,16(3):227-270
We review a number of formal verification techniques supported by STeP, the Stanford Temporal Prover, describing how the tool can be used to verify properties of several versions of the Bakery Mutual exclusion algorithm for mutual exclusion. We verify the classic two-process algorithm and simple variants, as well as an atomic parameterized version. The methods used include deductive verification rules, verification diagrams, automatic invariant generation, and finite-state model checking and abstraction. 相似文献
88.
Legal reasoning with subjective logic 总被引:1,自引:0,他引:1
Judges and jurors must make decisions in an environment of ignoranceand uncertainty for example by hearing statements of possibly
unreliable ordishonest witnesses, assessing possibly doubtful or irrelevantevidence, and enduring attempts by the opponents
to manipulate thejudge's and the jurors' perceptions and feelings. Three importantaspects of decision making in this environment
are the quantificationof sufficient proof, the weighing of pieces of evidence, and therelevancy of evidence. This paper proposes
a mathematical frameworkfor dealing with the two first aspects, namely the quantification ofproof and weighing of evidence.
Our approach is based on subjectivelogic, which is an extension of standard logic and probability theory,in which the notion
of probability is extended by including degrees ofuncertainty. Subjective Logic is a framework for modelling humanreasoning
and we show how it can be applied to legalreasoning. 相似文献
89.
A novel approach of combining flexible molecular docking, GRID molecular interaction fields, analysis of ligand-protein hydrogen bond interactions, conformational energy penalties and 3D-QSAR analysis was used to propose a binding mode in the dimer interface of the iGluR2 receptor for the biarylpropylsulfonamide class of positive allosteric AMPA modulators. Possible binding poses were generated by flexible molecular docking. GRID molecular interaction fields of the binding site, ligand-protein hydrogen bonding interactions and conformational energy penalties were used to select the most likely binding mode. The selected binding poses were subjected to a 3D-QSAR analysis using previously published activity data. The resulting model (2 LVs, R2=0.89, q2=0.61) predicted the activities of the compounds in the test set with a standard deviation on error of prediction of 0.17. The proposed binding mode was validated by interpretation of the PLS-coefficient regions from the 3D-QSAR analysis in terms of interactions between the receptor and the modulators. 相似文献
90.