全文获取类型
收费全文 | 639篇 |
免费 | 52篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 43篇 |
综合类 | 3篇 |
化学工业 | 139篇 |
金属工艺 | 12篇 |
机械仪表 | 25篇 |
建筑科学 | 36篇 |
矿业工程 | 2篇 |
能源动力 | 48篇 |
轻工业 | 63篇 |
水利工程 | 15篇 |
石油天然气 | 12篇 |
无线电 | 57篇 |
一般工业技术 | 94篇 |
冶金工业 | 48篇 |
原子能技术 | 5篇 |
自动化技术 | 92篇 |
出版年
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 40篇 |
2020年 | 36篇 |
2019年 | 47篇 |
2018年 | 56篇 |
2017年 | 49篇 |
2016年 | 52篇 |
2015年 | 23篇 |
2014年 | 50篇 |
2013年 | 74篇 |
2012年 | 47篇 |
2011年 | 32篇 |
2010年 | 29篇 |
2009年 | 23篇 |
2008年 | 19篇 |
2007年 | 9篇 |
2006年 | 11篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 16篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有694条查询结果,搜索用时 0 毫秒
91.
Meera Mahadevan Sangyool Lee Serguei V. Dessiatoun Michael Ohadi Ebrahim Al Hajri Kyu Yong Choi 《化学工程与技术》2016,39(2):293-300
The feasibility of using a microtubular reactor for heterogeneous polymerization of ethylene was investigated experimentally. Chemically inert polymer tubing of 800–2300 μm in inner diameter was fabricated and used as a polymerization reactor. Nonporous silica nanoparticles with a diameter of 400 nm were synthesized and used as support for the high‐activity rac‐ethylene(indenyl)2ZrCl2 catalyst with methylaluminoxane as cocatalyst and toluene as diluent. Large‐diameter microtubular reactors were also successfully used to conduct heterogeneous polymerization of ethylene in continuous reaction operations. High initial catalyst activity was obtained and the overall polymerization activity per volume or reactor length was quite high. No particle fragmentation occurred and the polymer particles were covered with small subgrains or nanofibrils with a diameter of 30 nm. 相似文献
92.
93.
94.
Asghari Kaljahi Ebrahim Amini Birami Farideh 《Bulletin of Engineering Geology and the Environment》2015,74(3):959-969
Bulletin of Engineering Geology and the Environment - Kandovan is one of the geo-tourism attractions in the East Azarbaijan Province of Iran, where rural houses were carved within the cone-shaped... 相似文献
95.
Kaveh Mohammad Amiri Chayjan Reza Taghinezhad Ebrahim Abbaspour Gilandeh Yousef Younesi Abdollah Rasooli Sharabiani Vali 《Engineering with Computers》2019,35(3):1045-1058
Engineering with Computers - In this paper, multi-stage continuous belt (MSCB) dryer was used for carrot slices drying. Experiments were performed at three air speeds (1, 1.5, and 2 m/s)... 相似文献
96.
Abbas Roozbahani Ebrahim Ebrahimi Mohammad Ebrahim Banihabib 《Water Resources Management》2018,32(15):4985-5005
Groundwater resources are steadily subjected to increasing water demands. The aquifers are considered as the most accessible source of fresh water. In recent years, they have been faced with severe water withdrawal in arid and semi-arid countries like Iran and thus some aquifers was considered as forbidden aquifers that it means the water withdrawal from these aquifers is unauthorized. Given a critical situation, groundwater resources management in the form of tools such as monitoring the level of the aquifers and developing the restoring scenarios is essential. Therefore, for this purpose, a framework has been developed based on prediction of groundwater level using Bayesian Networks (BNs) model. Furthermore, Multi Criteria Decision Making methods (MCDM) techniques proposed and employed for ranking of proposed groundwater management scenarios. This framework was evaluated for restoring the Birjand aquifer in Iran in different hydrological conditions. A probabilistic Dynamic BN was proposed for groundwater level prediction under uncertainties. After analyzing the obtained results, the applicable short term scenarios for groundwater management as well as appropriate economic, social and technical criteria were defined for decision making procedure. Then, using elicitation of decision makers’ opinions on the relative importance and performance of criteria, SAW, TOPSIS and PROMETHEE-II techniques were applied to rank the scenarios and the obtained results were aggregated by Borda method for final ranking of the scenarios. Lastly, the final results demonstrates the capability of the proposed framework for groundwater resources planning and management which can be employed for reducing the risk of aquifer level declining. 相似文献
97.
Nasrollah Najibi Ilkhechi Amin Ranjbar Aghjehkohal Ebrahim Feyzi TanourAghaj Mahdi Mozammel 《Journal of Materials Science: Materials in Electronics》2017,28(6):4598-4605
In this study, preparation of Si and Cd co doped (5 mol% Si and 5–20 mol% Cd) TiO2 dip-coated thin films on glass substrates via sol–gel process have been investigated. The samples were characterized by X-ray diffraction (XRD) and Scanning electron microscopy analysis after heat treatments. XRD results suggested that adding dopants has a great effect on crystallinity and particle size of TiO2. Titania rutile phase formation was inhibited by Si4+ and promoted by Cd2+ doping. But the effect of Cd doped appeared at high concentration. Accordingly, the thin films showed various water contact angles. The water contact angles changed from 69.0° to 9.6° by changing the content of Cd doped. 相似文献
98.
Babaei Hadi Eslami M. Reza 《International Journal of Mechanics and Materials in Design》2021,17(2):381-401
International Journal of Mechanics and Materials in Design - An attempt is made in the current research to analyse the nonlinear thermal stability and imperfection sensitivity of functionally... 相似文献
99.
Zeyad Ghaleb Al-Mekhlafi Ebrahim Mohammed Senan Taha H. Rassem Badiea Abdulkarem Mohammed Nasrin M. Makbol Adwan Alownie Alanazi Tariq S. Almurayziq Fuad A. Ghaleb 《计算机、材料和连续体(英文)》2022,72(1):775-796
Stroke and cerebral haemorrhage are the second leading causes of death in the world after ischaemic heart disease. In this work, a dataset containing medical, physiological and environmental tests for stroke was used to evaluate the efficacy of machine learning, deep learning and a hybrid technique between deep learning and machine learning on the Magnetic Resonance Imaging (MRI) dataset for cerebral haemorrhage. In the first dataset (medical records), two features, namely, diabetes and obesity, were created on the basis of the values of the corresponding features. The t-Distributed Stochastic Neighbour Embedding algorithm was applied to represent the high-dimensional dataset in a low-dimensional data space. Meanwhile,the Recursive Feature Elimination algorithm (RFE) was applied to rank the features according to priority and their correlation to the target feature and to remove the unimportant features. The features are fed into the various classification algorithms, namely, Support Vector Machine (SVM), K Nearest Neighbours (KNN), Decision Tree, Random Forest, and Multilayer Perceptron. All algorithms achieved superior results. The Random Forest algorithm achieved the best performance amongst the algorithms; it reached an overall accuracy of 99%. This algorithm classified stroke cases with Precision, Recall and F1 score of 98%, 100% and 99%, respectively. In the second dataset, the MRI image dataset was evaluated by using the AlexNet model and AlexNet + SVM hybrid technique. The hybrid model AlexNet + SVM performed is better than the AlexNet model; it reached accuracy, sensitivity, specificity and Area Under the Curve (AUC) of 99.9%, 100%, 99.80% and 99.86%, respectively. 相似文献
100.
Yahya Nabil A. A. Ebrahim Ahmed Abdulrab Ali Swillam Mohamed A. Abd-Shukor R. 《Journal of Superconductivity and Novel Magnetism》2022,35(9):2293-2300
Journal of Superconductivity and Novel Magnetism - The effects of nanoparticle additions, rolling, and sintering time on the transport critical current density, Jc, of Ag-sheathed... 相似文献