全文获取类型
收费全文 | 2226篇 |
免费 | 138篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 34篇 |
综合类 | 1篇 |
化学工业 | 772篇 |
金属工艺 | 59篇 |
机械仪表 | 61篇 |
建筑科学 | 62篇 |
矿业工程 | 3篇 |
能源动力 | 77篇 |
轻工业 | 221篇 |
水利工程 | 12篇 |
石油天然气 | 6篇 |
无线电 | 104篇 |
一般工业技术 | 459篇 |
冶金工业 | 61篇 |
原子能技术 | 15篇 |
自动化技术 | 424篇 |
出版年
2023年 | 20篇 |
2022年 | 65篇 |
2021年 | 109篇 |
2020年 | 53篇 |
2019年 | 69篇 |
2018年 | 118篇 |
2017年 | 79篇 |
2016年 | 132篇 |
2015年 | 100篇 |
2014年 | 130篇 |
2013年 | 223篇 |
2012年 | 110篇 |
2011年 | 170篇 |
2010年 | 135篇 |
2009年 | 105篇 |
2008年 | 106篇 |
2007年 | 90篇 |
2006年 | 58篇 |
2005年 | 43篇 |
2004年 | 37篇 |
2003年 | 27篇 |
2002年 | 29篇 |
2001年 | 20篇 |
2000年 | 21篇 |
1999年 | 15篇 |
1998年 | 20篇 |
1997年 | 26篇 |
1996年 | 19篇 |
1995年 | 11篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 13篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1980年 | 14篇 |
1979年 | 12篇 |
1978年 | 4篇 |
1977年 | 10篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1973年 | 5篇 |
排序方式: 共有2371条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Godfrey C. Onwubolu Petr Buryan Frank Lemke 《The International Journal of Advanced Manufacturing Technology》2008,39(11-12):1080-1092
This paper presents an enhanced approach to predictive modeling for determining tool-wear in end-milling operations based on enhanced-group method of data handling (e-GMDH). Using milling input parameters (speed, feed, and depth-of-cut) and response (tool wear), the data for the model is partitioned into training and testing datasets, and the training dataset is used to realize a predictive model that is a function of the input parameters and the coefficients determined. In our approach, we first present a methodology for modeling, and then develop predictive model(s) of the problem being solved in the form of second-order equations based on the input data and coefficients realized. This approach leads to some generalization because it becomes possible to predict not only the test data obtained during experimentation, but other test data outside the experimental results can also be used. Moreover, this approach makes it easy to present the realized solution in a form that can be further optimized for the input parameters using some optimization techniques. The results realized using our e-GMDH method are promising, and the comparative study presented shows that the e-GMDH outperforms polynomial neural network (PNN); moreover, it is more flexible than the conventional GMDH, which tends to produce nonlinear solutions even for simple problems. In the investigation, the extended particle swarm optimization (PSO) technique was applied to obtain the optimal parameters. Consequently, the modeling approach is extremely useful in realizing a computer-aided process-planning system in an advanced manufacturing environment. 相似文献
5.
6.
Petr A. Nikrityuk Kerstin Eckert Roger Grundmann 《Metallurgical and Materials Transactions B》2006,37(3):349-359
This paper presents a numerical study of the Lorentz force and fluid flow induced by a rotating magnetic field in a medium
with a nonhomogeneous electric conductivity placed in a cylindrical vessel with insulated walls. The nonhomogeneity is modeled
by the presence of a solid and a liquid phase of different electrical conductivity. The solid phase is located orthogonally
to the axis of rotation, which corresponds to the case of unidirectional solidification. The simulations were performed for
different locations of the solid front and different ratios of the electrical conductivity, σ
s
/σ
l
=0.2... 10. Here σ
s
and σ
l
are the electric conductivity of the solid and liquid phases, respectively. The results showed that the difference between
electrical conductivity of solid and liquid phases has a noticeable effect on the mean-time Lorentz force and the velocity:
namely, the presence of the solid phase (σ
s
>σ
l
) leads to an increase of the Lorentz force and fluid flow in the cylinder. 相似文献
7.
Jiři Gregor 《Mathematics of Control, Signals, and Systems (MCSS)》1991,4(2):205-215
A significant part of the theory of one-dimensional linear shift-invariant systems is based on the concept of weighting function
(or impulse response): the output is the convolution of the weighting function with the input. This paper introduces the concept
of linear translation-invariant systems and uses this notion in studying impulse response, z-transforms, and transfer functions
for multidimensional systems. 相似文献
8.
A new analytical method has been developed for the determination of the reactive lysine content of soya bean protein. The method is based on the reaction of the free basic groups of the protein with 1-phenylazo-2 naphthol-6,8 disulphonic acid. With regard to the stoichiometry of the procedure, it has been proved, contrary to earlier reports, that the basic amino acids, histidine, arginine and lysine, each combine with one mole of the dye. After acylation with propionic anhydride lysine alone loses its dye reactivity. The usefulness of the proposed method has been demonstrated by the determination of the reactive lysine content of several untreated, heat-treated and acid-treated soya bean samples. The results show that heat damage of about 5% in reactive lysine content can be measured in 1·5 h with good reproducibility. 相似文献
9.
10.
Petr Hájek Radko Mesiar 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2008,12(12):1239-1243
We investigate (quasi)copulas as possible truth functions of fuzzy conjunction which is not necessarily associative and present
some axiom systems for such fuzzy logics. In particular, we study an expansion of Łukasiewicz (infinite valued propositional)
logic by a new connective interpreted as an arbitrary quasicopula (and also by a new connective interpreted as the residuum
of the copula). Main results concern standard completeness. 相似文献