全文获取类型
收费全文 | 190篇 |
免费 | 33篇 |
专业分类
电工技术 | 6篇 |
综合类 | 1篇 |
化学工业 | 67篇 |
金属工艺 | 5篇 |
机械仪表 | 8篇 |
建筑科学 | 4篇 |
能源动力 | 6篇 |
轻工业 | 13篇 |
水利工程 | 1篇 |
无线电 | 26篇 |
一般工业技术 | 51篇 |
冶金工业 | 15篇 |
原子能技术 | 1篇 |
自动化技术 | 19篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 18篇 |
2019年 | 4篇 |
2018年 | 21篇 |
2017年 | 18篇 |
2016年 | 12篇 |
2015年 | 11篇 |
2014年 | 5篇 |
2013年 | 11篇 |
2012年 | 18篇 |
2011年 | 14篇 |
2010年 | 13篇 |
2009年 | 11篇 |
2008年 | 11篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2003年 | 3篇 |
2002年 | 4篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
1.
Removal of gaseous and vapor constituents of environmental tobacco smoke (ETS) by activated carbons in a packed bed arrangement was studied under dynamic conditions and was compared with that by silica gel and molecular sieve 13X. ETS is a mixture of sidestream smoke and exhaled mainstream smoke, and it consists of various organic and inorganic compounds, trace heavy metals, and particulate matters. Due to the complex nature of ETS-air mixture, its removal from indoors is a challenging task. For experimentation in a laboratory, the ETS was produced from a specially designed smoking apparatus that simulated the puffng of a cigarette by a person. Air containing ETS was passed through a bed containing about 25 grams of activated carbon at room temperature. The flow rate of air-ETS mixture through the bed was 4000 cm3/min. The relative humidity of the air was 50% and contained about 35 to 40 ppm of hydrocarbons as measured as methane-equivalent. The number of particles in the inlet air stream were in the range of 30,000 to 35,000 particles/cm3. About 60% of hydrocarbons present in ETS were removed at these operating conditions for a period of about 70 hours. Based on 15 adsorption and regeneration cycles, it was noted that the carbon bed did not loose its capacity for ETS significantly as indicated by the BET surface area and water adsorption data. At the beginning of an adsorption cycle, the carbon bed captured a significant number of particles. However, the bed rapidly lost its particle capture effciency as the experiment progressed. The number of particles in the outlet air stream was found to be the same as that of the inlet stream within five minutes. 相似文献
2.
Helmy Ahmed Garg Saurabh Nahata Nitin Pamu Priyatham 《Mobile Networks and Applications》2005,10(1-2):99-113
Traditional protocols for routing in ad hoc networks attempt to obtain optimal or shortest paths, and in doing so may incur significant route discovery overhead. Such approaches may be appropriate for routing long-lived transfers where the initial cost of route discovery may be amortized over the life of the connection. For short-lived connections, however, such as resource discovery and small transfers, traditional shortest path approaches may be quite inefficient. In this paper we propose a novel architecture, CARD, for resource discovery in large-scale wireless ad hoc networks. Our mechanism is suitable for resource discovery as well as routing very small data transfers or transactions in which the cost of data transfer is much smaller than the cost of route discovery. Our architecture avoids expensive mechanisms such as global flooding and complex hierarchy formation and does not require any location information. In CARD resources within the vicinity of a node, up to a limited number of hops, are discovered using a proactive scheme. For resources beyond the vicinity, each node maintains a few distant nodes called contacts. Contacts help in creating a small world in the network and provide an efficient way to query for distant resources. Using contacts, the network view (or reachability) of the nodes increases, reducing the discovery overhead and increasing the success rate. On the other hand, increasing the number of contacts also increases control overhead. We study such trade-off in depth and present mechanisms for contact selection and maintenance that attempt to increase reachability with reduced overhead. Our schemes adapt gracefully to network dynamics and mobility using soft-state periodic mechanisms to validate and recover paths to contacts. Our simulation results show that CARD is scalable and can be configured to provide desirable performance for various network sizes. Comparisons with other schemes show overhead savings reaching over 93% (vs. flooding) and 80% (vs. bordercasting or zone routing) for high query rates in large-scale networks. 相似文献
3.
Tushar S. Deore Amid L. Sadgar Radha V. Jayaram 《Journal of surfactants and detergents》2021,24(1):185-190
Ionic liquids have been found to be suitable alternatives to volatile organic solvents in chemical transformation. Through a proper choice of cations and anions, the properties of an ionic liquid can be tuned so that it resembles an amphiphile. Such specially designed molecules are known as surface-active ionic liquids (SAIL). Like conventional surfactants, SAIL also form aggregates in an aqueous medium. Studies show that the mixing of SAIL with conventional surfactants leads to synergistic micellization. However, very few reports are available on the application of such systems as reaction media. Present study focuses on the application of mixed micelles of 1-tetradecyl-3-methylimidazol-1-ium bromide, ([C14mim]Br) with nonionic surfactant, Octylphenol ethoxylate with 10 moles of ethylene oxide (OPE-10). Enhanced solubilization and selective catalytic oxidation of toluene using hydrogen peroxide as an oxidant and tungstic acid as a catalyst have been studied in detail using this system. 相似文献
4.
The Journal of Supercomputing - Hpcfolder is a user-friendly high-performance computing tool that can be used to analyze the performance of algorithms parallelized using MPI. It is possible to view... 相似文献
5.
Tushar Chopra Mitchell H. Rosner 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(1):11-18
The past year has seen interesting publications in the fields of chronic kidney disease and end stage renal disease. This review highlights some of these important papers and places their findings in the context of clinical care. 相似文献
6.
Tushar Goel Nielen Stander Yih-Yih Lin 《Structural and Multidisciplinary Optimization》2010,41(3):421-432
This study pertains to practical use of the GA for industrial applications where only a limited number of simulations can
be afforded. Specifically, an attempt is made to find an efficient allocation of the total simulation budget (population size
and number of generations) for constrained multi-objective optimization. A study is conducted to seek improvements while restricting
the number of simulations to 1,000. Parallelization is exploited using concurrent simulations for each GA generation on a
HP quad-core cluster, and resulted in a significant time savings. Furthermore, the efficient distribution of computational
effort to achieve the greatest improvement in performance was explored. Two analytical examples as well as an automotive crashworthiness
simulation of a finite element model with 58,000 elements were used as test examples. Various population sizes and numbers
of generations were tried while limiting the total number of simulations to 1,000. The optimization performance was compared
with Monte-Carlo and space filling sampling methods. It was observed that using the GA, many feasible and trade-off solutions
could be found. It is shown that allowing a large number of generations is beneficial to get good trade-off solutions. For
the vehicle design, significant improvements in the performance were observed. This example also suggests that, for problems
with a small feasible region, the number of feasible solutions can be significantly increased in the first few generations
involving about 200 simulations. 相似文献
7.
Krishna Tushar Kumar Amit Peh Li-Shiuan Postman Jacob Chiang Patrick Erez Mattan 《Micro, IEEE》2009,29(4):48-61
Networks on chip must deliver high bandwidth at low latencies while keeping within a tight power envelope. Using express virtual channels for flow control improves energy-delay throughput by letting packets bypass intermediate routers, but EVCs have key limitations. Nochi (NoC with hybrid interconnect) overcomes these limitations by transporting data payloads and control information on separate planes, optimized for bandwidth and latency respectively. 相似文献
8.
A Combinatorial Approach for Assessing the Magnetic Properties of High Entropy Alloys: Role of Cr in AlCoxCr1–xFeNi
下载免费PDF全文
![点击此处可从《Advanced Engineering Materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
9.
10.
Photoswitchable Membranes Based on Peptide‐Modified Nanoporous Anodic Alumina: Toward Smart Membranes for On‐Demand Molecular Transport
下载免费PDF全文
![点击此处可从《Advanced materials (Deerfield Beach, Fla.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)