全文获取类型
收费全文 | 403篇 |
免费 | 26篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
综合类 | 5篇 |
化学工业 | 128篇 |
金属工艺 | 27篇 |
机械仪表 | 11篇 |
建筑科学 | 14篇 |
矿业工程 | 1篇 |
能源动力 | 46篇 |
轻工业 | 33篇 |
石油天然气 | 2篇 |
无线电 | 26篇 |
一般工业技术 | 74篇 |
冶金工业 | 6篇 |
原子能技术 | 1篇 |
自动化技术 | 53篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 12篇 |
2021年 | 25篇 |
2020年 | 26篇 |
2019年 | 33篇 |
2018年 | 43篇 |
2017年 | 33篇 |
2016年 | 31篇 |
2015年 | 24篇 |
2014年 | 33篇 |
2013年 | 50篇 |
2012年 | 21篇 |
2011年 | 21篇 |
2010年 | 21篇 |
2009年 | 17篇 |
2008年 | 12篇 |
2007年 | 12篇 |
2006年 | 5篇 |
2004年 | 3篇 |
排序方式: 共有431条查询结果,搜索用时 31 毫秒
91.
In this paper, a novel hybrid approach is proposed for predicting peak particle velocity (PPV) due to bench blasting in open pit mines. The proposed approach is based on the combination of adaptive neuro-fuzzy inference system (ANFIS) and particle swarm optimization (PSO). In this approach, the PSO is used to improve the performance of ANFIS. Furthermore, a model is developed based on support vector regression (SVR) approach. The models are trained and tested based on actual data compiled from 120 blast rounds in Sarcheshmeh copper mine. To determine the accuracy and efficiency of ANFIS–PSO and SVR models, a statistical model (USBM equation) is applied. According to the obtained results, both techniques can be used to predict the PPV, but the comparison of models shows that the ANFIS–PSO model provides better results. Root mean square error (RMSE), variance account for (VAF), and coefficient of determination (R 2) indices were obtained as 1.83, 93.37 and 0.957 for ANFIS–PSO model, respectively. 相似文献
92.
A novel method based on model predictive control (MPC) is presented for synthesis and optimization of a wide band reflector antenna with cosecant squared and flat‐topped radiation patterns. The proposed system is a doubly curved reflector antenna with nonlinear dynamic equation. This article investigates design and optimization of a double ridged horn reflector antenna operating within the frequency range of 8 to 18 GHz. In order to synthesize the proposed reflector antenna, MPC is used to achieve the desired radiation cosecant pattern. This method utilizes system model and tries to find the best control effort for minimizing the cost function by predicting the future behavior. The system differential equation is comprised of first and second order derivatives, so MPC can be a good solution for synthesis of a doubly reflector antenna. MPC optimizer operates based on state space model, so the proposed system is linearized in the operating range. Maximum error, the average error and side lobe level of this method for the radiation pattern of the proposed wideband antenna respectively are 1.4, 0.9, and ?20 dB. Simulation results of the radiation pattern in CST and HFSS software show that the proposed reflector antenna can be used in broadband surveillance radar systems. 相似文献
93.
Amir Ghasemi Hamed Amiri Hossein Zare Maryam Masroor Akbar Hasanzadeh Ali Beyzavi Amir R. Aref Mahdi Karimi 《Microfluidics and nanofluidics》2017,21(9):151
Advanced nanomaterials such as carbon nanotubes (CNTs) display unprecedented properties such as strength, electrical conductance, thermal stability, and intriguing optical properties. These properties of CNT allow construction of small microfluidic devices leading to miniaturization of analyses previously conducted on a laboratory bench. With dimensions of only millimeters to a few square centimeters, these devices are called lab-on-a-chip (LOC). A LOC device requires a multidisciplinary contribution from different fields and offers automation, portability, and high-throughput screening along with a significant reduction in reagent consumption. Today, CNT can play a vital role in many parts of a LOC such as membrane channels, sensors and channel walls. This review paper provides an overview of recent trends in the use of CNT in LOC devices and covers challenges and recent advances in the field. CNTs are also reviewed in terms of synthesis, integration techniques, functionalization and superhydrophobicity. In addition, the toxicity of these nanomaterials is reviewed as a major challenge and recent approaches addressing this issue are discussed. 相似文献
94.
95.
Sangtarash Hosein Arab Hamed G. Sohrabi Mohammad R. Ghasemi Mohammad R. 《Engineering with Computers》2021,37(4):2837-2852
Engineering with Computers - This paper presents a new four-node quadrilateral flat shell element, named QFSUQ, for analysis of shell structures. The element is formed by assemblage of a new... 相似文献
96.
We present an efficient approach for solving nonlinear fractional differential equations. The convergence analysis of the approach is studied. To demonstrate the working of the presented approach, we consider three special cases of nonlinear fractional differential equations. The results of theses examples and comparison with different methods provide confirmation for the validity of the proposed approach. 相似文献
97.
Amiri Iraj S. Sorger Volker J. Ariannejad M. M. Ling Xi Ghasemi M. Yupapin P. 《Microsystem Technologies》2018,24(3):1673-1681
Microsystem Technologies - This paper reports on an approach for fabrication of micro-channels with nanometer thickness achieved by optimization of UV lithography processes. Rectangular... 相似文献
98.
Mohammad Javad Raee Ahmad Gholami Mohammad Bagher Ghoshoon Younes Ghasemi 《分离科学与技术》2018,53(9):1397-1404
Purification is one of the most important steps in biotechnological downstream process. This procedure is associated with some difficulties including several separation steps. Common cell separation procedures are usually time and energy consuming that also compromises cell growth, viability and reusability. Magnetic immobilization was introduced as a novel separation technique to provide a quick, easy and convenient alternative vs. traditional cell harvesting methods. In this study, recombinant E. coli producing extracellular asparaginase was decorated by synthesized L-lysine coated iron oxide nanoparticles and cell growth, immobilization efficiency and asparaginase productivity was evaluated. 相似文献
99.
Copper-phthalocyanine and nickel nanoparticles as novel cathode catalysts in microbial fuel cells 总被引:1,自引:0,他引:1
Mostafa Ghasemi Wan Ramli Wan Daud Mostafa Rahimnejad Majid Rezayi Amin Fatemi Yaghoob Jafari M.R. Somalu Alireza Manzour 《International Journal of Hydrogen Energy》2013
In this study, four different catalysts (i.e., carbon black, nickel nanoparticle (Ni)/C, Phthalocyanine/C and copper-phthalocyanine/C), were tested in a two-chamber Microbial Fuel Cell (MFC) and their performances were compared with Pt as the common cathode catalyst in MFC. The characterization of catalysts was done by TEM, XPS and EDX and their electrochemical characteristics were compared by cyclic voltammetry (CV) and Linear Sweep Voltammetry (LSV). The results proved that copper phthalocyanine and nickel nanoparticles are potential alternatives catalyst for Pt. Even copper-phthalocyanine generated power is almost the same as Pt. The CV and LSV results reported high electrochemical activity of these catalysts. The maximum power density and coulombic efficiency was achieved by copper-phthalocyanine/C as 118.2 mW/m2 and 29.3%. 相似文献
100.
M. Salehi Doolabi B. Ghasemi S. K. Sadrnezhaad A. Habibolahzadeh K. Jafarzadeh 《Oxidation of Metals》2018,89(3-4):429-451