全文获取类型
收费全文 | 1167篇 |
免费 | 121篇 |
专业分类
电工技术 | 12篇 |
综合类 | 2篇 |
化学工业 | 317篇 |
金属工艺 | 8篇 |
机械仪表 | 21篇 |
建筑科学 | 66篇 |
矿业工程 | 1篇 |
能源动力 | 32篇 |
轻工业 | 260篇 |
水利工程 | 9篇 |
石油天然气 | 1篇 |
无线电 | 46篇 |
一般工业技术 | 197篇 |
冶金工业 | 38篇 |
原子能技术 | 1篇 |
自动化技术 | 277篇 |
出版年
2024年 | 5篇 |
2023年 | 12篇 |
2022年 | 21篇 |
2021年 | 48篇 |
2020年 | 43篇 |
2019年 | 38篇 |
2018年 | 66篇 |
2017年 | 56篇 |
2016年 | 63篇 |
2015年 | 47篇 |
2014年 | 73篇 |
2013年 | 123篇 |
2012年 | 104篇 |
2011年 | 100篇 |
2010年 | 63篇 |
2009年 | 71篇 |
2008年 | 58篇 |
2007年 | 75篇 |
2006年 | 42篇 |
2005年 | 37篇 |
2004年 | 35篇 |
2003年 | 40篇 |
2002年 | 15篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有1288条查询结果,搜索用时 31 毫秒
991.
In recent years a great effort has been devoted to understanding the nature of model transformations. As a result, several
mechanisms to improve model transformation languages have been proposed. Phasing has been mentioned in some works as a rule
scheduling or organization mechanism, but without any detail. In this paper, we present a phasing mechanism in the context of rule-based transformation languages. We explain the structure and the behavior of the mechanism, and how
it can be integrated in a language. We also analyze how the mechanism promotes modularity, internal transformation composition
and helps to solve usual transformation problems. Besides, we show several examples of application to illustrate the usefulness
of the mechanism. 相似文献
992.
Constrained domain maximum likelihood estimation for naive Bayes text classification 总被引:1,自引:0,他引:1
The naive Bayes assumption in text classification has the advantage of greatly simplifying maximum likelihood estimation of
unknown class-conditional word occurrence probabilities. However, these estimates are usually modified by application of a
heuristic parameter smoothing technique to avoid (over-fitted) null estimates. In this work, we advocate the reduction of
the parameter domain instead of parameter smoothing. This leads to a constrained domain maximum likelihood estimation problem
for which we provide an iterative algorithm that solves it optimally. 相似文献
993.
Andrea Giovannucci Jesús Cerquides Ulle Endriss Juan A. Rodríguez-Aguilar 《Autonomous Agents and Multi-Agent Systems》2010,20(3):342-368
Mixed multi-unit combinatorial auctions are auctions that allow participants to bid for bundles of goods to buy, for bundles
of goods to sell, and for transformations of goods. The intuitive meaning of a bid for a transformation is that the bidder
is offering to produce a set of output goods after having received a set of input goods. To solve such an auction the auctioneer
has to choose a set of bids to accept and decide on a sequence in which to implement the associated transformations. Mixed
auctions can potentially be employed for the automated assembly of supply chains of agents. However, mixed auctions can be
effectively applied only if we can also ensure their computational feasibility without jeopardising optimality. To this end,
we propose a graphical formalism, based on Petri nets, that facilitates the compact represention of both the search space
and the solutions associated with the winner determination problem for mixed auctions. This approach allows us to dramatically
reduce the number of decision variables required for solving a broad class of mixed auction winner determination problems.
An additional major benefit of our graphical formalism is that it provides new ways to formally analyse the structural and
behavioural properties of mixed auctions. 相似文献
994.
José de Jesús Rubio Jesus Lopez Jaime Pacheco Rodrigo Encinas 《Asian journal of control》2018,20(4):1504-1518
In this paper, a controller is recommended for the regulation of two electrical plants. Since electrical plants generate electricity all the time, the regulation to get that all the plant states reach constant behaviors is important. Two main characteristics of the introduced method are: (i) it is based in the separation of the plant model equations, only some model equations are chosen for the regulation while the other model equations are ignored, it avoids the difficulty in the consideration of the full plant model; (ii) the Lyapunov strategy is employed to analyze the stability of the selected model equations in the electrical plant, it lets to ensure the regulation purpose. The advised method is applied in a gas turbine and a wind turbine for the electricity generation. 相似文献
995.
Mery Carolina Pazos Zarama Jesús Sigifredo Valencia Ríos M. D. Alba M. A. Castro 《Journal of Porous Materials》2007,14(2):239-242
The zeolite beta is a crystalline synthetic aluminosilicate with wide-pore size (6 to 9 Å) and a Si/Al ratio from 5 to 100. In this study, we have investigated the influence of several synthesis parameters on the physicochemical properties of the materials. The synthesis of zeolite beta has been performed by hydrothermal method, the aluminum source and gallium content in the structure being variable. The structural characterization was carried out by means of X-ray diffraction, SEM and 27Al and 71Ga MAS NMR spectroscopy. When the aluminum sulfate is used as aluminium source, zeolite beta with higher crystallinity is generated. All the samples showed a XRD pattern similar to crystalline zeolite beta and the 27Al and 71Ga MAS NMR spectrum demonstrated that the incorporation of both heteroatoms was efficient. 相似文献
996.
Rosa M. Badia Jesús Labarta Raül Sirvent Josep M. Pérez José M. Cela Rogeli Grima 《Journal of Grid Computing》2003,1(2):151-170
The aim of GRID superscalar is to reduce the development complexity of Grid applications to the minimum, in such a way that writing an application for a computational Grid may be as easy as writing a sequential application. Our assumption is that Grid applications would be in a lot of cases composed of tasks, most of them repetitive. The granularity of these tasks will be of the level of simulations or programs, and the data objects will be files. GRID superscalar allows application developers to write their application in a sequential fashion. The requirements to run that sequential application in a computational Grid are the specification of the interface of the tasks that should be run in the Grid, and, at some points, calls to the GRID superscalar interface functions and link with the run-time library.GRID superscalar provides an underlying run-time that is able to detect the inherent parallelism of the sequential application and performs concurrent task submission. In addition to a data-dependence analysis based on those input/output task parameters which are files, techniques such as file renaming and file locality are applied to increase the application performance. This paper presents the current GRID superscalar prototype based on Globus Toolkit 2.x, together with examples and performance evaluation of some benchmarks. 相似文献
997.
We investigate the effects of outliers on the KPSS tests. We find that for nonstationary series outliers induce spurious stationarity
by lowering the power of these tests. The empirical size of these tests is also found to be sensitive to the location of the
outlier.
JEL classification: C15, C22
An erratum to this article can be found at 相似文献
998.
It has been argued that the aim of non-linearities in different visual and auditory mechanisms may be to remove the relations between the coefficients of the signal after global linear ICA-like stages. Specifically, in Schwartz and Simoncelli (2001), it was shown that masking effects are reproduced by fitting the parameters of a particular non-linearity in order to remove the dependencies between the energy of wavelet coefficients. In this work, we present a different result that supports the same efficient encoding hypothesis. However, this result is more general because, instead of assuming any specific functional form for the non-linearity, we show that by using an unconstrained approach, masking-like behavior emerges directly from natural images. This result is an additional indication that Barlow's efficient encoding hypothesis may explain not only the shape of receptive fields of V1 sensors but also their non-linear behavior. 相似文献
999.
García J Trigo JD Alesanco A Serrano P Mateo J Istepanian RS 《Computer methods and programs in biomedicine》2007,88(3):273-282
In this paper a new wireless decision-support system for haemodialysis patients using heart rate variability (HRV) is presented. The telemedicine system provides connectivity to three participant sites: the general practitioner or nurse at the point of care in the dialysis unit, the remote information and processing server and the cardiologist. At the clinical point of care, the nurse acquires the electrocardiogram (ECG) by using a tailored mobile telecardiology system as well as other relevant physiological information during the clinical procedure, and sends it to the information server. The received information is stored in a secure file server, linked to the patient database and the ECG signal is automatically analyzed by using advanced signal processing tools in the processing server, where a complete clinical results report is generated. The cardiologist can then be linked by means of a web browser to the information server to analyze these results for further clinical diagnosis support. The system has been applied to study HRV in patients undergoing haemodialysis. The clinical report consisted of trends for time- and frequency-domain HRV indexes and other supplementary information automatically calculated, which show the response of the electrical activity of the heart to the dialysis process and that can be helpful for the follow-up of these patients. The telecardiology framework has been successfully evaluated both by the patients and the hospital personnel showing a high compliance with the system. The design and implementation of the telecardiology system have followed the most recent advances in web technologies, biomedical information and storage standards and signal processing techniques. The presented system can be used as a telemedicine tool for clinical diagnosis support and could also be used in other clinical settings. 相似文献
1000.
Co‐administration of Antimicrobial Peptides Enhances Toll‐like Receptor 4 Antagonist Activity of a Synthetic Glycolipid
下载免费PDF全文
![点击此处可从《ChemMedChem》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Fabio A. Facchini Dr. Helena Coelho Stefania E. Sestito Dr. Sandra Delgado Alberto Minotti Prof. David Andreu Prof. Jesús Jiménez‐Barbero Prof. Francesco Peri 《ChemMedChem》2018,13(3):280-287
This study examines the effect of co‐administration of antimicrobial peptides and the synthetic glycolipid FP7, which is active in inhibiting inflammatory cytokine production caused by TLR4 activation and signaling. The co‐administration of two lipopolysaccharide (LPS)‐neutralizing peptides (a cecropin A–melittin hybrid peptide and a human cathelicidin) enhances by an order of magnitude the potency of FP7 in blocking the TLR4 signal. Interestingly, this is not an additional effect of LPS neutralization by peptides, because it also occurs if cells are stimulated by the plant lectin phytohemagglutinin, a non‐LPS TLR4 agonist. Our data suggest a dual mechanism of action for the peptides, not exclusively based on LPS binding and neutralization, but also on a direct effect on the LPS‐binding proteins of the TLR4 receptor complex. NMR experiments in solution show that peptide addition changes the aggregation state of FP7, promoting the formation of larger micelles. These results suggest a relationship between the aggregation state of lipid A‐like ligands and the type and intensity of the TLR4 response. 相似文献