全文获取类型
收费全文 | 1123篇 |
免费 | 35篇 |
学科分类
工业技术 | 1158篇 |
出版年
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 30篇 |
2020年 | 21篇 |
2019年 | 17篇 |
2018年 | 16篇 |
2017年 | 30篇 |
2016年 | 38篇 |
2015年 | 21篇 |
2014年 | 36篇 |
2013年 | 66篇 |
2012年 | 59篇 |
2011年 | 73篇 |
2010年 | 47篇 |
2009年 | 57篇 |
2008年 | 57篇 |
2007年 | 40篇 |
2006年 | 45篇 |
2005年 | 31篇 |
2004年 | 29篇 |
2003年 | 29篇 |
2002年 | 27篇 |
2001年 | 24篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 60篇 |
1997年 | 41篇 |
1996年 | 20篇 |
1995年 | 12篇 |
1994年 | 24篇 |
1993年 | 23篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 15篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有1158条查询结果,搜索用时 15 毫秒
81.
Bertrand Baud-Lavigne Samuel Bassetto Bruno Agard 《Journal of Intelligent Manufacturing》2016,27(4):741-749
This paper proposes a method for finding a robust solution to the problem of joint product family and supply chain design. Optimizing product design and the supply chain network at the same time brings substantial benefits. However, this approach involves decisions that can generate uncertainties in the long term. The challenge is to come up with a method that can adapt to most possible environments without straying too far from the optimal solution. Our approach is based on the generation of scenarios that correspond to combinations of uncertain parameters within the model. The performance of designs resulting from these scenario optimizations are compared to the performance of each of the other design scenarios, based on their probability of occurrence. The proposed methodology will allow practitioners to choose a suitable design, from the most profitable to the most reliable. 相似文献
82.
Gustafson C Tretiak O Bertrand L Nissanov J 《Computer methods and programs in biomedicine》2004,74(1):53-61
Visualization software for three dimensional digital brain atlases present many challenges in design and implementation. These challenges include the design of an effective human interface, management of large data sets, display speed when slicing the data set for viewing/browsing, and the display of delineated volumes of interest (VOI). We present a software design, implementation and storage architecture that addresses these issues, allowing the user to navigate through a reconstructed volume quickly and smoothly, with an easy-to-use human interface. The software (macostat, for use with Macintosh OS) allows the user to rapidly display slices of the digital atlas at any arbitrary slicing angle, complete with delineated VOIs. The VOIs can be assigned colors of the user's choosing. The entire atlas, or selected portions, may be resliced with slices stored as individual image files, complete with delineations. These delineations may be transferred to corresponding sections of experimental materials using our analysis program (brain). The software may be obtained from the laboratory's web site: http://www.neuroterrain.org 相似文献
83.
Improving the spatio-temporal distribution of surface solar radiation data by merging ground and satellite measurements 总被引:2,自引:0,他引:2
Appropriate information on solar resources is very important for a variety of technological areas, such as: agriculture, meteorology, forestry engineering, water resources and in particular in the designing and sizing of solar energy systems. However, the availability of observed solar radiation measurements has proven to be spatially and temporally inadequate for many applications. In this paper we propose to merge the global solar radiation measurements from the Royal Meteorological Institute of Belgium solar measurements network with the operationally derived surface incoming global short-wave radiation products from Meteosat Second Generation satellites imageries to improve the spatio-temporal resolution of the surface global solar radiation data over Belgium. We evaluate several merging methods with various degrees of complexity (from mean field bias correction to geostatistical merging techniques) together with interpolated ground measurements and satellite-derived values only. The performance of the different methods is assessed by leave-one-out cross-validation. 相似文献
84.
This paper describes a parameterized distributed algorithm applicable to any directed graph topology. The function parameter
of our algorithm is instantiated to produce distributed algorithms for both fundamental and high level applications, such
as shortest path calculus and depth-first-search tree construction. Due to fault resilience properties of our algorithm, the
resulting protocols are self-stabilizing at no additional cost. Self-stabilizing protocols can resist transient failures and
guarantee system recovery in a finite time. Since the condition on the function parameter (being a strictly idempotent r-operator) permits a broad range of applications to be implemented, the solution presented in our paper can be useful for
a large class of distributed systems.
Received: August 1999 / Accepted: January 2001 相似文献
85.
In this paper we introduce a new symmetry feature named “symmetry kernel” (SK) to support a measure of symmetry. Given any symmetry transform S, SK of a pattern P is the maximal included symmetric sub-set of P for all directions and shifts. We provide a first algorithm to exhibit this kernel where the centre of symmetry is assumed to be the centre of mass. Then we prove that, in any direction, the optimal axis corresponds to the maximal correlation of a pattern with its symmetric version. That leads to a second algorithm. The associated symmetry measure is a modified difference between the respective surfaces of a pattern and its kernel. A series of experiments supports the actual algorithm validation. 相似文献
86.
This paper investigates single-machine coupled-task scheduling where each job has two tasks separated by an exact delay. The objective of this study is to schedule the tasks to minimize the makespan subject to a given job sequence. We introduce several intriguing properties of the fixed-job-sequence problem under study. While the complexity status of the studied problem remains open, an O(n2) algorithm is proposed to construct a feasible schedule attaining the minimum makespan for a given permutation of 2n tasks abiding by the fixed-job-sequence constraint. We investigate several polynomially solvable cases of the fixed-job-sequence problem and present a complexity graph of the problem. 相似文献
87.
Dominique Bertrand Marc Lila Vincent Furtoss Paul Robert Gerard Downey 《Journal of the science of food and agriculture》1987,41(4):299-307
Application of principal component regression (PCR) was proposed for the development of a prediction equation of forage composition by near infra-red spectroscopy. PCR involves two steps: (a) the creation of new synthetic variables by principal component analysis (PCA) of spectral data, and (b) multiple linear regression with these new variables. Results obtained by this procedure have been compared with those generated by the conventional application of multiple linear regression (MLR) on spectral data. The comparison used the determination of protein content and in vitro dry matter digestibility (IVDMD) in 345 samples of lucerne forages. For protein determination, results of both procedures were quite similar (correlation coefficients: 0.978 and 0.980; standard errors of calibration: 0.86 and 0.84% DM; standard errors of prediction: 0.81 and 0.80% DM respectively for MLR and PCR prediction equations). The same was observed for IVDMD determination (correlation coefficients: 0.942 and 0.951; standard errors of calibration: 1.89 and 1.71% DM; standard errors of prediction: 2.22 and 2.22% DM, respectively). A large number of PCA variables were necessary for an accurate prediction of both constituents. The influence of the number of regression terms introduced in the PCR equation has been studied. The criterion for stopping the introduction of new terms in PCR did not seem as critical as in MLR. 相似文献
88.
Cocontraction changes in muscular fatigue at different levels of isometric contraction 总被引:1,自引:0,他引:1
Denis Gagnon A. Bertrand Arsenault Gilmen Smyth Fran ois Kemp 《International Journal of Industrial Ergonomics》1992,9(4):343-348
Ten normal subjects participated in a study designed to contrast results obtained in pre- and post-fatigue states. The measures contrasted were the IEMG ratios of agonist/antagonist pairs of muscles. The experimental task was an 8 s ramp isometric elbow flexion ranging from 0 to 100% of a maximal voluntary contraction (MVC). IEMG ratios were obtained at levels of 20, 40, 60 and 80% MVC. Records from the following muscles were obtained with surface electrodes: biceps brachii (BB), brachioradialis (BR), triceps brachii (TB) and anconeus (SU). The torque at the elbow joint was measured by a Cybex II dynamometer. Fatigue was induced using a 60% MVC of elbow flexion maintained during 5 minutes. The data were collected on-line at a sampling rate of 1 kHz. The results indicated that the IEMG ratios (BB/TB and BR/SU) presented a tendency, across subjects, toward a decrease at the levels of 40%, 60% and 80% MVC at the post- relative to the pre-fatigue state. The BB/BR ratios remained stable. These changes in the post-fatigue ratios disclose a tendency toward a saturation of the agonist occurring concomitantly with an increased level of contraction of the antagonists. 相似文献
89.
Monocrystalline platelets of pentahydrate Copper sulfate are submitted to temperature and pressure conditions such that they cause this salt to be converted into a trihydrated salt. Thermal equilibrium of these platelets is ensured before the reaction starts. Temperature is recorded as moving away from the superficial domain undergoing conversion, by means of an I.R. scanning camera fitted with a cooled detecting device. The occurence of a thermal gradient from the reactive solid-solid interface can, thus, be shown. It seems, therefore necessary to take into account the physical properties of the crystal, which are involved in the occurence of thermal gradients in the solid, to explain the anisotropy of this interface displacement during a conversion where a gas is removed. 相似文献
90.
In this paper, various discrete-time estimation problems are studied for a finite and homogeneous Markov chain observed by a marked point process. These problems, which could have significant applications in target tracking, manufacturing or communication theory, have never been studied in the literature. The quantities to be estimated are the state, the number of jumps and the occupation times. The identification of the chain transition matrix is also addressed via an expectation maximization procedure. Solutions, in the sense of the conditional distribution, are obtained by a change of probability measure and are shown to have convenient recursive forms. The efficiency of this new approach for sensor modeling is illustrated by the study of a linear Markovian jump filtering problem where, in addition to a classical state observation, a mode Markov point process observation is assumed. A numerical example is given 相似文献