全文获取类型
收费全文 | 2007篇 |
免费 | 110篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 504篇 |
金属工艺 | 61篇 |
机械仪表 | 70篇 |
建筑科学 | 88篇 |
矿业工程 | 7篇 |
能源动力 | 178篇 |
轻工业 | 356篇 |
水利工程 | 7篇 |
石油天然气 | 16篇 |
无线电 | 71篇 |
一般工业技术 | 389篇 |
冶金工业 | 42篇 |
原子能技术 | 10篇 |
自动化技术 | 306篇 |
出版年
2024年 | 12篇 |
2023年 | 23篇 |
2022年 | 47篇 |
2021年 | 82篇 |
2020年 | 69篇 |
2019年 | 62篇 |
2018年 | 123篇 |
2017年 | 107篇 |
2016年 | 120篇 |
2015年 | 81篇 |
2014年 | 118篇 |
2013年 | 303篇 |
2012年 | 94篇 |
2011年 | 125篇 |
2010年 | 150篇 |
2009年 | 114篇 |
2008年 | 100篇 |
2007年 | 97篇 |
2006年 | 44篇 |
2005年 | 29篇 |
2004年 | 32篇 |
2003年 | 15篇 |
2002年 | 22篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 13篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 12篇 |
1980年 | 6篇 |
1978年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有2119条查询结果,搜索用时 15 毫秒
1.
M.D. Mikhailov M.N. Özişik 《International Communications in Heat and Mass Transfer》1985,12(4):393-404
A new, powerful method of analysis, involving the combined use of finite integral transform and finite element techniques, is presented for the solution of time dependent heat flow systems composed of many one-dimensional elements connected through the nodes. This method leads to an eigenvalue problem which is not of the conventional Sturm-Liouville type. A procedure for the determination of the eigenvalues is described. The solution obtained is in the form of an infinite series and contains quasi-steady and transient terms. The general solution obtained can be applied in the mathematical modelling of many engineering applications such as the determination of the penetration of the daily temperature cycle into buildings, the analysis of heat transfer in array of extended surfaces in compact heat exchangers, and many others. 相似文献
2.
In this paper, an automatic diagnosis system for diabetes on Linear Discriminant Analysis (LDA) and Morlet Wavelet Support Vector Machine Classifier: LDA–MWSVM is introduced. The structure of this automatic system based on LDA-MWSVM for the diagnosis of diabetes is composed of three stages: The feature extraction and feature reduction stage by using the Linear Discriminant Analysis (LDA) method and the classification stage by using Morlet Wavelet Support Vector Machine (MWSVM) classifier stage. The Linear Discriminant Analysis (LDA) is used to separate features variables between healthy and patient (diabetes) data in the first stage. The healthy and patient (diabetes) features obtained in the first stage are given to inputs of the MWSVM classifier in the second stage. Finally, in the third stage, the correct diagnosis performance of this automatic system based on LDA–MWSVM for the diagnosis of diabetes is calculated by using sensitivity and specificity analysis, classification accuracy, and confusion matrix, respectively. The classification accuracy of this system was obtained at about 89.74%. 相似文献
3.
Fatih Çalışır Muhammet Baştan Özgür Ulusoy Uğur Güdükbay 《Multimedia Tools and Applications》2017,76(10):12433-12456
High user interaction capability of mobile devices can help improve the accuracy of mobile visual search systems. At query time, it is possible to capture multiple views of an object from different viewing angles and at different scales with the mobile device camera to obtain richer information about the object compared to a single view and hence return more accurate results. Motivated by this, we propose a new multi-view visual query model on multi-view object image databases for mobile visual search. Multi-view images of objects acquired by the mobile clients are processed and local features are sent to a server, which combines the query image representations with early/late fusion methods and returns the query results. We performed a comprehensive analysis of early and late fusion approaches using various similarity functions, on an existing single view and a new multi-view object image database. The experimental results show that multi-view search provides significantly better retrieval accuracy compared to traditional single view search. 相似文献
4.
5.
6.
7.
Victor Verbiţchi Aurel-Valentin Bîrdeanu Nicuşor-Alin Sîrbu 《International Journal of Electronics》2013,100(8):1092-1099
An experimental model of a voltage–frequency converter was realised and utilised for the control of the thermal behaviour by the laser welding of thermoplastic polymer materials. The input signal of 0–10?V comes from a thermal–optical real-time analysing device of the welding process. The output signal of 0–300?Hz is introduced to the input interface of a laser welding equipment, for setting the laser pulse frequency. Operation tests were performed on the laser welding equipment type HL 124P LCU. The pulses have rectangular waveform, with the amplitude of 20?V. The frequency is very stable, with deviations of less than 0.5?Hz. The waveform and the frequency response at the converter output are appropriate. 相似文献
8.
Irradiation combined with a conventional cooking procedure was applied to meatball and the effects on bacterial load and inoculatedAeromonas hydrophila were determined. Meatball samples were irradiated by using a60Co source at the dose levels of 0, 0.30,0.75,1.50,2.50 kGy and cold stored at 4±1°C for 7 days. Bacterial load and the count ofA. hydrophila decreased when the irradiation dose level increased. A minimum inhibition effect was found at the dose of 0.30 kGy. Irradiation in combination with a conventional cooking procedure was found to be more effective in reducingA. hydrophila and the bacterial load in meatball. This study indicated that a dose of 0.75 kGy was sufficient to destroy approximately 104 cfu/g ofA. hydrophila in meatball. 相似文献
9.
L. Feştilă R. Groza M. Cîrlugea A. Fazakas 《Analog Integrated Circuits and Signal Processing》2007,50(3):231-249
We systematized and developed some procedures for the modular design of externally-linear internally nonlinear (ELIN) circuits
resulting in a general LIN↔ELIN transformation procedure. This one was also extended to analysis of these types of circuits.
The procedure is exemplified on log-domain circuits. In the design one starts with the linear block diagram (LIN) described
by transfer functions and one substitutes directly each linear building block by a corresponding nonlinear one. The parameters
of each nonlinear component depend on the given parameters of its linear correspondent. Input F
−1 and output F blocks are added. In the analysis one identifies the nonlinear basic circuit components and each of them is
substituted by its corresponding linear building block. Input and output F
−1-F cells are removed. The ideal transfer function can be calculated on the linear block diagram now. The LIN↔ELIN transformations
make a direct connection between equivalent linear and ELIN circuits, simplify their design and analysis procedures and permit
the development of CAD procedures. 相似文献
10.
In this paper, we present a multiuser detection technique based on artificial neural network (NN) for synchronous multicarrier code division multiple access systems over Rayleigh fading channels. To test the robustness of the proposed receiver, also the effect of power control problem is studied with a comparative manner. Bit error rate (BER) performance of the NN based receiver is compared with the single user bound and conventional receivers. Although the BER performance of the conventional receiver degrades as the number of the users and power level differences among the users increase, as a decision structure, neural network based receiver gives closer BER performance to the single user bound. 相似文献