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361.
In this double-blind, cross-over, placebo-controlled, randomized study, two groups of eight healthy male volunteers were challenged with endotoxin (4 ng/kg) on two occasions, once in conjunction with placebo and once with granulocyte colony-stimulating factor (G-CSF; 5 microg/kg). In group 1, G-CSF was administered intravenously 2 hours before endotoxin challenge; in group 2, G-CSF was administered subcutaneously 24 hours before endotoxin challenge. In group 1, G-CSF significantly enhanced the release of tumor necrosis factor (TNF), interleukin-6 (IL-6), IL-8, IL-1 receptor antagonist (IL-1ra), and soluble TNF receptors. In group 2, G-CSF significantly reduced IL-8 concentrations and modestly attenuated TNF and IL-6 levels. In this group, IL-1ra and soluble TNF receptors were enhanced by G-CSF pretreatment and lipopolysaccharide (LPS)-induced soluble TNF receptor release was further augmented, whereas LPS-induced IL-1ra concentrations remained unaltered. Both pretreatments with G-CSF increased LPS-induced peripheral neutrophilia; the expression of CD11b, CD18, and CD67; and the release of elastase and lactoferrin. Both pretreatments also down-regulated neutrophil L-selectin expression and prevented the endotoxin-induced pulmonary neutrophil accumulation during the first 2 hours after endotoxin challenge. These data indicate that two different pretreatments with G-CSF result in differential effects on LPS-induced cytokine release but similar effects on LPS-induced neutrophil activation and changes in expression of cell surface molecules. Finally, regardless of the effects of G-CSF on LPS-induced cytokine release, G-CSF blocks LPS-induced pulmonary granulocyte accumulation.  相似文献   
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A technique for measuring neutron excitation functions using wide energy neutron beams is explored. Samples are activated with a set of neutron fields, each covering a relatively wide energy interval and created using an ion accelerator and conventional nuclear reactions. Measured activities are determined using gamma-ray spectrometry and reduced to excitation curves using spectrum unfolding. The technique is demonstrated on the measurement of the excitation function curve up to 5.6 MeV for 113In(n,n′)113Inm using the 115In(n,n′)115Inm reaction as an internal standard.  相似文献   
364.
In the past 10 years, the research community has produced a significant number of design notations to represent security properties and concepts in a design artifact. These notations are aimed at documenting and analyzing security in a software design model. The fragmentation of the research space, however, has resulted in a complex tangle of different techniques. Hence, practitioners are confronted with the challenging task of scouting the right approach from a multitude of proposals. Similarly, it is hard for researchers to keep track of the synergies among the existing notations, in order to identify the existing opportunities for original contributions. This paper presents a systematic literature review that inventorizes the existing notations and provides an in-depth, comparative analysis for each.  相似文献   
365.
Over the last few years, advanced digital applications have become available to tourists. Some of these offer the possibility of creating personalised routes. This paper introduces a tourist expert system, called the City Trip Planner, that allows planning routes for five cities in Belgium. It is implemented as a web application that takes into account the interests and trip constraints of the user and matches these to a database of locations in order to predict personal interests. A fast and effective planning algorithm provides an on-the-fly suggestion of a personal trip for a requested number of days, taking into account opening hours of attractions and time for a (lunch) break. The expert system is discussed in detail. Usage statistics and user feedback demonstrate that it is highly appreciated by tourists.  相似文献   
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Candida bombicola is a yeast species known to synthesize glycolipids. Although these glycolipids find several industrial, cosmetic and pharmaceutical applications, very little is known about the genetics of C. bombicola. A basic tool for genetic study and modification is the availability of an efficient transformation and selection system. In order to develop such a system, the URA3 gene of Candida bombicola was isolated using degenerate PCR and genomic walking. The gene encodes for an enzyme of 262 amino acids and shows high homology with the known orotidine-5'-phosphate decarboxylases of several other yeast species. The functionality of the gene was proved by complementation of a URA3-negative Saccharomyces cerevisiae strain.  相似文献   
368.
    
We give a general overview of the state-of-the-art in subspace system identification methods. We have restricted ourselves to the most important ideas and developments since the methods appeared in the late eighties. First, the basics of linear subspace identification are summarized. Different algorithms one finds in literature (such as N4SID, IV-4SID, MOESP, CVA) are discussed and put into a unifying framework. Further, a comparison between subspace identification and prediction error methods is made on the basis of computational complexity and precision of the methods by applying them on 10 industrial data sets.  相似文献   
369.
    
Virtual characters in games and simulations often need to plan visually convincing paths through a crowded environment. This paper describes how crowd density information can be used to guide a large number of characters through a crowded environment. Crowd density information helps characters avoid congested routes that could lead to traffic jams. It also encourages characters to use a wide variety of routes to reach their destination. Our technique measures the desirability of a route by combining distance information with crowd density information. We start by building a navigation mesh for the walkable regions in a polygonal two‐dimensional (2‐D) or multilayered three‐dimensional (3‐D) environment. The skeleton of this navigation mesh is the medial axis. Each walkable region in the navigation mesh maintains an up‐to‐date density value. This density value is equal to the area occupied by all the characters inside a given region divided by the total area of this region. These density values are mapped onto the medial axis to form a weighted graph. An A* search on this graph yields a backbone path for each character, and forces are used to guide the characters through the weighted environment. The characters periodically replan their routes as the density values are updated. Our experiments show that we can compute congestion‐avoiding paths for tens of thousands of characters in real‐time. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
370.
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