全文获取类型
收费全文 | 2198篇 |
免费 | 163篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 21篇 |
综合类 | 2篇 |
化学工业 | 483篇 |
金属工艺 | 46篇 |
机械仪表 | 95篇 |
建筑科学 | 91篇 |
矿业工程 | 4篇 |
能源动力 | 206篇 |
轻工业 | 321篇 |
水利工程 | 26篇 |
石油天然气 | 16篇 |
无线电 | 144篇 |
一般工业技术 | 370篇 |
冶金工业 | 103篇 |
原子能技术 | 36篇 |
自动化技术 | 399篇 |
出版年
2024年 | 9篇 |
2023年 | 27篇 |
2022年 | 62篇 |
2021年 | 105篇 |
2020年 | 70篇 |
2019年 | 66篇 |
2018年 | 127篇 |
2017年 | 89篇 |
2016年 | 126篇 |
2015年 | 75篇 |
2014年 | 113篇 |
2013年 | 274篇 |
2012年 | 127篇 |
2011年 | 161篇 |
2010年 | 136篇 |
2009年 | 201篇 |
2008年 | 115篇 |
2007年 | 88篇 |
2006年 | 77篇 |
2005年 | 38篇 |
2004年 | 37篇 |
2003年 | 24篇 |
2002年 | 26篇 |
2001年 | 14篇 |
2000年 | 22篇 |
1999年 | 14篇 |
1998年 | 28篇 |
1997年 | 13篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有2363条查询结果,搜索用时 15 毫秒
61.
In this paper, the maximum length limits for integral bridges built on clay are determined as a function of the ability of steel H-piles supporting the abutments to sustain thermal-induced cyclic displacements and the flexural capacity of the abutment. First, H-pile sections that can accommodate large plastic deformations are determined considering their local buckling instability. Then, a low-cycle fatigue damage model is used to determine the maximum cyclic deformations that such piles can sustain. Next, nonlinear static pushover analyses of two typical integral bridges are conducted to study the effect of various geometric, structural, and geotechnical parameters on the performance of integral bridges subjected to uniform temperature variations. Using the pushover analyses results, design guidelines are developed to enhance and determine the maximum length limits for integral bridges built on clay. It is recommended that the maximum length of concrete integral bridges be limited to 210 m (689 ft) in cold climates and 260 m (853 ft) in moderate climates and that of steel integral bridges be limited to 120 m (394 ft) in cold climates and 180 m (590 ft) in moderate climates. 相似文献
62.
N. Emrahoğlu İ. Yeğingil V. Peştemalci O. Şenkal H. M. Kandirmaz 《International journal of remote sensing》2013,34(4):649-655
In this study, a new classification algorithm in which only the selected pixels have been attempted to be classified (selected pixels classification: SPC) has been introduced and compared with the well known supervised classification methods such as maximum likelihood, minimum distance, nearest neighbour and condensed nearest neighbour. To examine the algorithm, Landsat Thematic Mapper (TM) data have been used to classify the crop cover in the selected region. It is clearly demonstrated that the SPC method has the higher accuracy with comparable CPU times. 相似文献
63.
Ertugrul Yildirim Alper Aslan Ilhan Ozturk 《Renewable & Sustainable Energy Reviews》2012,16(8):6123-6127
The paper investigates the causality relationships among industrial production index, coal consumption and employment in industrial sector for the period of 1973:1–2011:10 in USA. After noticing that there are breaks in the regression model, the Hatemi-J test for cointegration is employed to the cases that take into account two possible regime shifts. It is concluded that there is a long run relationship between industrial production and industrial coal consumption with the breaks at 1983:4 and 1998:4. We found a negative relationship between coal consumption and industrial production for the period of 1973:1–1983:4 and positive relationship for 1983:5–1998:4 period. For the last period that covers 1983:5–2011:10, the cointegration relationship turned to negative. In addition, the results show that causal relationship between coal consumption and industrial production changes over time. 相似文献
64.
Neural Computing and Applications - In this paper, we consider a system of nonlinear delay integro-differential equations with convolution kernels, which arises in biology. This problem... 相似文献
65.
66.
67.
68.
Investigating the effect of production process of ball mill refiner on some physical quality parameters of compound chocolate: response surface methodology approach
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Omer Said Toker Fatma Tugce Zorlucan Nevzat Konar Orhan Dağlıoğlu Osman Sagdic Dilek Şener 《International Journal of Food Science & Technology》2017,52(3):788-799
Chocolate compound was produced using ball mill refiner, and the effect of agitator shaft speed and refining time on the physical quality parameters (particle size, colour and steady‐state rheology) of compound chocolate was determined using response surface methodology. The shaft speed and refining time range were selected between 40–60 r.p.m. and 10–30 min, respectively. Determination coefficient of the models established for particle size, Newtonian viscosity and colour parameters (brightness, chroma and hue angle) were found to be very close to unity. Increasing shaft speed and time induced a reduction in particle size and an increase in viscosity of the samples. Temperature sweep test was also performed, and the obtained data were successfully fitted to Arrhenius equation to calculate the corresponding parameters representing temperature dependency of the compounds. The results highlighted that the establishment of such models can provide essential information in terms of optimisation of production processes regarding usage purpose of the compound chocolate. 相似文献
69.
Adel Alaeddini Kai Yang Alper Murat 《Quality and Reliability Engineering International》2013,29(2):241-258
Most preset response surface methodology (RSM) designs offer ease of implementation and good performance over a wide range of process and design optimization applications. These designs often lack the ability to adapt the design on the basis of the characteristics of application and experimental space so as to reduce the number of experiments necessary. Hence, they are not cost‐effective for applications where the cost of experimentation is high or when the experimentation resources are limited. In this paper, we present an adaptive sequential response surface methodology (ASRSM) for industrial experiments with high experimentation cost, limited experimental resources, and high design optimization performance requirement. The proposed approach is a sequential adaptive experimentation approach that combines concepts from nonlinear optimization, design of experiments, and response surface optimization. The ASRSM uses the information gained from the previous experiments to design the subsequent experiment by simultaneously reducing the region of interest and identifying factor combinations for new experiments. Its major advantage is the experimentation efficiency such that for a given response target, it identifies the input factor combination (or containing region) in less number of experiments than the classical single‐shot RSM designs. Through extensive simulated experiments and real‐world case studies, we show that the proposed ASRSM method outperforms the popular central composite design method and compares favorably with optimal designs. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
70.
We report on an experimental study of the effects of interphase boundary anisotropy on eutectic microstructures using a new methodology called rotating directional solidification (RDS), which consists of rotating a thin sample with respect to a fixed unidirectional thermal gradient. The systems used are thin, large eutectic grains of the CBr4–C2Cl6 and In–In2Bi lamellar eutectic alloys. The shape of the observed RDS lamellar trajectories turns out to be a reproducible eutectic-grain-dependent feature, in agreement with the theoretical prediction that these trajectories are approximately homothetic to the Wulff form of the interphase boundary in the sample plane. We show that different modes of lamellar growth, ranging from quasi-isotropic to (crystallographically) locked, exist in different eutectic grains of the two alloys studied. A detailed characterisation of these modes is given, with particular attention to the as-yet poorly understood aspects of locked lamellar growth. 相似文献