全文获取类型
收费全文 | 1388篇 |
免费 | 73篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 20篇 |
综合类 | 5篇 |
化学工业 | 182篇 |
金属工艺 | 35篇 |
机械仪表 | 40篇 |
建筑科学 | 123篇 |
矿业工程 | 4篇 |
能源动力 | 55篇 |
轻工业 | 120篇 |
水利工程 | 14篇 |
石油天然气 | 4篇 |
无线电 | 178篇 |
一般工业技术 | 196篇 |
冶金工业 | 94篇 |
原子能技术 | 7篇 |
自动化技术 | 385篇 |
出版年
2023年 | 12篇 |
2022年 | 10篇 |
2021年 | 31篇 |
2020年 | 24篇 |
2019年 | 17篇 |
2018年 | 41篇 |
2017年 | 32篇 |
2016年 | 50篇 |
2015年 | 43篇 |
2014年 | 45篇 |
2013年 | 115篇 |
2012年 | 87篇 |
2011年 | 81篇 |
2010年 | 86篇 |
2009年 | 71篇 |
2008年 | 67篇 |
2007年 | 92篇 |
2006年 | 75篇 |
2005年 | 50篇 |
2004年 | 49篇 |
2003年 | 63篇 |
2002年 | 30篇 |
2001年 | 23篇 |
2000年 | 30篇 |
1999年 | 23篇 |
1998年 | 22篇 |
1997年 | 12篇 |
1996年 | 23篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 13篇 |
1992年 | 19篇 |
1991年 | 15篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1966年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有1462条查询结果,搜索用时 15 毫秒
11.
Differentiation of apple juice samples on the basis of heat treatment and variety using chemometric analysis of MIR and NIR data 总被引:4,自引:0,他引:4
Linda M. Reid Tony Woodcock Colm P. ODonnell J. Daniel Kelly Gerard Downey 《Food research international (Ottawa, Ont.)》2005,38(10):1109-1115
The potential of mid-infrared (MIR) and near-infrared (NIR) spectroscopy for their ability to differentiate between apple juice samples on the basis of apple variety and applied heat-treatment was evaluated. The heat-treatment involved exposure of juice samples (15 ml) for 30 s in a 900 W microwave oven and the apple varieties used to produce the juice samples were Bramley, Elstar, Golden Delicious and Jonagold. The chemometric procedures applied to the MIR and NIR data were partial least squares regression (PLS1 for differentiation on the basis of heat-treatment, PLS2 for varietal differentiation) and linear discriminant analysis (LDA) applied to principal component (PC) scores. PLS1 and PLS2 gave the highest level of correct classification of the apple juice samples according to heat-treatment (77.2% for both MIR and NIR data) and variety (78.3–100% for MIR data; 82.4–100% for NIR data), respectively. 相似文献
12.
13.
Uncertainty of Predictions of Embankment Dam Breach Parameters 总被引:3,自引:0,他引:3
Tony L. Wahl 《Canadian Metallurgical Quarterly》2004,130(5):389-397
Risk assessment studies considering the failure of embankment dams often require the prediction of basic geometric and temporal parameters of a breach, or the estimation of peak breach outflows. Many of the relations most commonly used to make these predictions were developed from statistical analyses of data collected from historic dam failures. The prediction uncertainties of these methods are widely recognized to be very large, but have never been specifically quantified. This paper presents an analysis of the uncertainty of many of these breach parameter and peak flow prediction methods. Application of the methods and the uncertainty analysis are illustrated through a case study of a risk assessment recently performed by the Bureau of Reclamation for a large embankment dam in North Dakota. 相似文献
14.
15.
16.
Tony C. Scott Robert Mann Roberto E. Martinez II 《Applicable Algebra in Engineering, Communication and Computing》2006,17(1):41-47
We present a canonical form for a natural and necessary generalization of the Lambert W function, natural in that it requires minimal mathematical definitions for this generalization, and necessary in that it provides a means of expressing solutions to a number of physical problems of fundamental nature. This generalization expresses the exact solutions for general-relativistic self-gravitating N-body systems in one spatial and one time dimension, and a previously unknown mathematical link between the (1+1) gravity problem and the Schrödinger wave equation. 相似文献
17.
Integrated Microfluidic CustomArray Device for Bacterial Genotyping and Identification 总被引:2,自引:0,他引:2
18.
Xu Y Xu D Lin S Han TX Cao X Li X 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2012,42(3):729-739
In this paper, we study the problem of detecting sudden pedestrian crossings to assist drivers in avoiding accidents. This application has two major requirements: to detect crossing pedestrians as early as possible just as they enter the view of the car-mounted camera and to maintain a false alarm rate as low as possible for practical purposes. Although many current sliding-window-based approaches using various features and classification algorithms have been proposed for image-/video-based pedestrian detection, their performance in terms of accuracy and processing speed falls far short of practical application requirements. To address this problem, we propose a three-level coarse-to-fine video-based framework that detects partially visible pedestrians just as they enter the camera view, with low false alarm rate and high speed. The framework is tested on a new collection of high-resolution videos captured from a moving vehicle and yields a performance better than that of state-of-the-art pedestrian detection while running at a frame rate of 55 fps. 相似文献
19.
Dave McKenney Tony White 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2012,16(2):247-259
This paper investigates the speed improvements available when using a graphics processing unit (GPU) for evaluation of individuals
in a genetic programming (GP) environment. An existing GP system is modified to enable parallel evaluation of individuals
on a GPU device. Several issues related to implementing GP on GPU are discussed, including how to perform tree-based GP on
a device without recursion support, as well as the effect that proper memory layout can have on speed increases when using
CUDA-enabled nVidia GPU devices. The specific GP implementation is designed to evolve stock trading strategies using technical
analysis indicators. The second goal of this research is to investigate the possible improvement in performance when training
individuals on a larger number of stocks and training days. This increased training size (nearly 100,000 training points)
is enabled due to the speedups realized by GPU evaluation. Several different scenarios were used to test various speed optimizations
of GP evaluation on the GPU device, with a peak speedup factor of over 600 (when compared to sequential evaluation on a 2.4 GHz
CPU). Also, it is found that increasing the number of stocks and the length of the training period can result in higher out-of-training
testing profitability. 相似文献
20.
Tony Cheng-Kui Huang 《Applied Soft Computing》2012,12(3):1068-1086
Comprehending changes of customer behavior is an essential problem that must be faced for survival in a fast-changing business environment. Particularly in the management of electronic commerce (EC), many companies have developed on-line shopping stores to serve customers and immediately collect buying logs in databases. This trend has led to the development of data-mining applications. Fuzzy time-interval sequential pattern mining is one type of serviceable data-mining technique that discovers customer behavioral patterns over time. To take a shopping example, (Bread, Short, Milk, Long, Jam), means that Bread is bought before Milk in a Short period, and Jam is bought after Milk in a Long period, where Short and Long are predetermined linguistic terms given by managers. This information shown in this example reveals more general and concise knowledge for managers, allowing them to make quick-response decisions, especially in business. However, no studies, to our knowledge, have yet to address the issue of changes in fuzzy time-interval sequential patterns. The fuzzy time-interval sequential pattern, (Bread, Short, Milk, Long, Jam), became available in last year; however, is not a trend this year, and has been substituted by (Bread, Short, Yogurt, Short, Jam). Without updating this knowledge, managers might map out inappropriate marketing plans for products or services and dated inventory strategies with respect to time-intervals. To deal with this problem, we propose a novel change mining model, MineFuzzChange, to detect the change in fuzzy time-interval sequential patterns. Using a brick-and-mortar transactional dataset collected from a retail chain in Taiwan and a B2C EC dataset, experiments are carried out to evaluate the proposed model. We empirically demonstrate how the model helps managers to understand the changing behaviors of their customers and to formulate timely marketing and inventory strategies. 相似文献