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71.
Maryam Mehrnezhad Abbas Ghaemi Bafghi Ahad Harati Ehsan Toreini 《International Journal of Information Security》2017,16(2):133-149
This paper introduces pictorial intelligent system for human identification (PiSHi), an image-based captcha which uses three human cognitive abilities to distinguish humans from machines. The first is the human ability to easily recognise the image’s upright orientation. The second is the human brain’s ability in recognising a picture’s content when it is only partially visible. And the third is the human ability in unconscious decision making when encountering pictorial challenges. This work models such complicated human patterns in problem solving for the first time. In order to extract these behavioural patterns and save them in a pattern database, we have implemented our own captcha and performed a series of experiments. PiSHi’s interface presents the user with a set of distorted pictures and asks her to click on the upright orientation of all the pictures in any preferred order. Next, it captures the user’s interaction patterns, compares them with the ones saved in the pattern database, and grants her a corresponding credit. Based on this credit, the user either passes or fails the test, and participates in updating the picture database. Our experiments indicate that human users can solve our proposed captcha effectively—with an accuracy of 99.44 %. Besides, our proposed system is secure against several types of attacks including random guessing and reverse image search engines. The results offer the possibility of utilising the identified human behavioural models in practical captchas. 相似文献
72.
Computational Visual Media - Photometric stereo is a fundamental technique in computer vision known to produce 3D shape with high accuracy. It uses several input images of a static scene taken from... 相似文献
73.
Output feedback controller for polytopic systems exploiting the direct searching of the design space
This paper deals with the problem of designing a robust static output feedback controller for polytopic systems. The current research that tackled this problem is mainly based on LMI method, which is conservative by nature. In this paper, a novel approach is proposed, which considers the design space of the controller parameters and iteratively partitions the space to small simplexes. Then, by assessing the stability in each simplex, the solution space for design parameters is directly determined. It has been theoretically proved that, if there exists a feasible solution in the design space, the algorithm can find it. To validate the result of the proposed approach, comparative simulation examples are given to illustrate the performance of the design methodology as compared to those of previous approaches. 相似文献
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76.
This paper presents a developed geometric approach for deriving the typologies and geometries of discontinuous double-shell
domes in Islamic architecture. Common geometric attributes are created using a corpus of twenty one domes that were built
in the Middle East and Central Asia, beginning from the early through to the late Islamic periods. An outline of the origin
and development of the discontinuous double-shell domes and their morphological features are addressed. Using the al-Kashi
geometrical essences, a four-centered profile as an initial shape is constructed based on new geometric parameters to deduce
the geometric commonalities of the two aspects of formal language (typologies and geometries) of such domes. Common geometric
prototypes for typical profiles shared by the study cases are generated and formulated according to a proposed system. The
theoretical frame work for the formal language of discontinuous double-shell dome architecture is structured to indicate a
moderate development of this sort of Islamic domes and highlight the specific geometric relationship between the Islamic domical
configurations and practical mathematic rules for many decades. It can also be established a basic approach for considering
the geometric compositional designs and the typological derivations of the other eastern domes. 相似文献
77.
78.
A. Nadjafi Maryam Negari R. S. Mamoory A. Simchi N. Ehsani 《Powder Metallurgy and Metal Ceramics》2007,46(9-10):423-428
Microwave energy is highly efficient for heating and processing different materials. In recent years, this type of heat transfer has been used in sintering process. Rapid and highly efficient heating, time and energy saving, and improved properties of sintered materials are advantages of microwave sintering. In this paper, Fe and Fe-Cu powder compact samples (cylindrical and bone shapes) are sintered both in microwave and electrical tube furnaces. The microwave generator has 2.45 GHz frequency and 1 KW power. Times are selected in the range of 5–25 min for microwave sintering and 5–40 min for electrical heating. The sintering temperature is set at 1120°C. Samples are sintered in the reducing atmosphere of 95% N2 + 5% H2 mixture. The density, hardness, and tensile strength of the samples are measured. The results are compared. The results show that the microwave-sintered materials have a finer microstructure. The microwave-sintered materials have 6–8% higher density, 5–10 HV5 higher hardness, and about 10% higher tensile strength than conventionally sintered materials. 相似文献
79.
Maryam Imani 《International journal of remote sensing》2013,34(17):4297-4314
In this article, we propose a feature extraction method based on median–mean and feature line embedding (MMFLE) for the classification of hyperspectral images. In MMFLE, we maximize the class separability using discriminant analysis. Moreover, we remove the negative effect of outliers on the class mean using the median–mean line (MML) measurement and virtually enlarge the training set using the feature line (FL) distance metric. The experimental results on Indian Pines and University of Pavia data sets show the better performance of MMFLE compared to nearest feature line embedding (NFLE), median–mean line discriminant analysis (MMLDA), and some other feature extraction approaches in terms of classification accuracy using a small training set. 相似文献
80.
The 1996 Welfare to Work Mandate has had a significant impact on the lives of families that use public assistance. What role can university counseling and psychology training programs play in the facilitation of this mandate that is intended to return welfare recipients to work? The Welfare Reform Act is discussed in relation to an innovative program that provides graduate-level training for bachelor's-level social service workers to meet the challenges of new service-delivery mandates. Relevance of this collaborative effort to professional psychology is explored, and implications for training master's-level graduate students are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献