全文获取类型
收费全文 | 400篇 |
免费 | 38篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 3篇 |
综合类 | 2篇 |
化学工业 | 141篇 |
金属工艺 | 2篇 |
机械仪表 | 17篇 |
建筑科学 | 13篇 |
能源动力 | 16篇 |
轻工业 | 53篇 |
石油天然气 | 2篇 |
无线电 | 39篇 |
一般工业技术 | 79篇 |
冶金工业 | 17篇 |
自动化技术 | 60篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 47篇 |
2021年 | 52篇 |
2020年 | 31篇 |
2019年 | 25篇 |
2018年 | 26篇 |
2017年 | 27篇 |
2016年 | 31篇 |
2015年 | 17篇 |
2014年 | 14篇 |
2013年 | 31篇 |
2012年 | 10篇 |
2011年 | 19篇 |
2010年 | 21篇 |
2009年 | 12篇 |
2008年 | 15篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有444条查询结果,搜索用时 15 毫秒
121.
122.
Khurshid Hafiz Fatima Farran Hani Allawnha Mohamad Ayoub Mohammad El‐Chafei 《The International journal of environmental studies》2013,70(4):433-443
Idling the engine of heavy‐duty truck is the only way a driver can control the temperature in the cab/sleeper and have power for auxiliary devices when the truck is parked. It is an inefficient and noisy process that wastes thousands of litres of fuel per year while standing stationary in a parking lot. Almost all heavy‐duty trucks idle about 20–40% of the time when the engine is running, depending on season, geographic location and trucking operation. This extensive engine idling has many disadvantages, including pollutant emissions, noise pollution, unnecessary fuel and maintenance costs, and driver discomfort. This paper discusses the problems related to truck idling and proposes an auxiliary power generation unit that can significantly reduce the fuel consumption, cut the costs, enhance engine life and reduce pollution. A control methodology is presented to regulate the output voltage of the auxiliary power unit under variable load conditions. 相似文献
123.
Bilal Ahmed Anam Hashmi Mohammad Saghir Khan Javed Musarrat 《Advanced Powder Technology》2018,29(7):1601-1616
Yellow pepper extract and quercetin (QDH) were used for YPE-AgNPs and Q-AgNPs fabrication. The AgNPs were thoroughly characterized using standard physico-chemical techniques and were found monodispersed, pleomorphic and had variable shape and size with a lattice fringe of 0.23?nm. YPE-AgNPs and Q-AgNPs revealed a characteristic SPR band at 438?nm and 431?nm. The XRD crystal size of YPE-AgNPs and Q-AgNPs was 10.16 and 12.20?nm while TEM analysis showed a size range of 5–40 and 1–25?nm. Bio-fabricated AgNPs remained stable for at least four weeks as the SPR did not deviate with time. FTIR data revealed functionalization of AgNPs by organics of reaction mixture. AgNPs had robust antibacterial and antibiofilm activity against ESβL(+) Escherichia coli, Pseudomonas aeruginosa, and methicillin sensitive and resistant Staphylococcus aureus. Staining of isolates with fluorescent probes displayed the increased production of ROS and membrane permeability. AgNPs hampered EPS production, endorsed DNA leakage, and generated superoxide radicals. Time and concentration dependent experiments demonstrated a consistent decrease in bacterial growth. Structural changes viz. irregular margins, distortion, depressions/indentations and shrinkage of cells were obvious under SEM. AgNPs due to strong antibacterial activity could be exploited as a supplement with antibacterial drugs to control resilient human infections. 相似文献
124.
125.
Dwi Susilaningsih Louis S. Sirait Khairul Anam M. Sidiq Habibi Bambang Prasetya 《International Journal of Hydrogen Energy》2014
A prototype system for hydrogen gas production from a biological system of facultative fermentation has been applied for electricity power supply. The prototype was designed for application in remote or isolated areas in Indonesia. The fermentation system, which was designed to be as simple as possible, includes the preparation of the microbial seed, the substrate material, the vessel and other required equipment, gas capture and purification, a converter, and transportation. The model experiment in the field undergoes several modifications depending on the biomass sources in the actual location, i.e., some areas have agroforestry, sugarcane, soy sauce and palm sugar wastes. The light intensity and temperature followed the natural conditions. The results indicated that a cultivation scale of 5–25 L per substrate does not affect the result, i.e., a hydrogen production of approximately 60–70% of the total gas produced. The hydrogen gas produced was converted into electricity sources to power fans and house lamps. However, the hydrogen power is not yet sustainable due to the batch fermentation system, the biomass supply and the local electrical system, which is conventional (not a grid system). We propose to merge the electrical system in those areas, i.e., combining the source of electrical power from wind, solar, biomass, ocean current and fossil fuel-based generators. The model of the electricity pool system is important for Indonesia because, geographically, Indonesia consists of more than seventeen thousand islands, where the electricity supply remains unstable. 相似文献
126.
Kaniz Fatima Sultana So Young Lee Ji-Eun Lee Joobeom Seo Shim Sung Lee 《Inorganic chemistry communications》2007,10(12):1496-1500
Two 20-membered penta- and hexadentate macrocycles containing one or two pyridine subunits, namely [20]aneNO2S2 (L1) and [20]aneN2O2S2 (L2), have been synthesized. Reaction of L1 with silver(I) nitrate afforded a unique 2:2 (M:L) disilver(I) complex [μ2-Ag2(L1)2](NO3)2 (1) in which two four-coordinate Ag atoms bridge two ligands to form a cyclic dimer. In contrast, an endo-dentate 1:1 monosilver(I) complexes [AgL2]X; [X = ClO4 (2) or PF6 (3)] which show isomorphous structures were obtained from the reactions of L2 with silver(I) salts. 相似文献
127.
Yassin Fatima Mohamed Ouarda Wael Alimi Adel M. 《Multimedia Tools and Applications》2022,81(5):6599-6631
Multimedia Tools and Applications - As an increasingly larger number of users partake in Facebook, the images shared and posted by user in Facebook provide a richer background to build a more... 相似文献
128.
129.
Ahmed Naveed Bakar Kamalrulnizam Abu Zuhra Fatima Tul Kehkashan Tanzila Mujahid Muhammad Akram Rathore Muhammad Siraj Dawood Muhammad Isyaku Babangida 《International Journal of Wireless Information Networks》2022,29(3):314-340
International Journal of Wireless Information Networks - Due to fast development in digital systems, the traditional network architecture is becoming inadequate for the requirements of new... 相似文献
130.
We implement and undertake an empirical study of the cache-oblivious variant of the polygon indecomposability testing algorithm of Gao and Lauder, based on a depth-first search (DFS) traversal of the computation tree. According to Abu Salem, the cache-oblivious variant exhibits improved spatial and temporal locality over the original one, and its spatial locality is optimal. Our implementation revolves around eight different variants of the DFS-based algorithm, tailored to assess the trade-offs between computation and memory performance as originally proposed by Abu Salem. We analyse performance sensitively to manipulations of the several parameters comprising the input size. We describe how to construct suitably random families of input that solicit such variations, and how to handle redundancies in vector computations at no asymptotic increase in the work and cache complexities. We report extensively on our experimental results. In all eight variants, the DFS-based variant achieves excellent performance in terms of L1 and L2 cache misses as well as total run time, when compared to the original variant of Gao and Lauder. We also benchmark the DFS variant against the powerful computer algebra system MAGMA, in the context of bivariate polynomial irreducibility testing using polygons. For sufficiently high degree polynomials, MAGMA either runs out of memory or fails to terminate after about 4 h of execution. In contrast, the DFS-based version processes such input using a couple of seconds. Particularly, we report on absolute irreducibility testing of bivariate polynomials of total degree reaching 19,000 in about 2 s for the DFS variant, using a single processor. 相似文献