全文获取类型
收费全文 | 112篇 |
免费 | 21篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 24篇 |
金属工艺 | 3篇 |
机械仪表 | 4篇 |
建筑科学 | 3篇 |
能源动力 | 4篇 |
轻工业 | 6篇 |
无线电 | 18篇 |
一般工业技术 | 53篇 |
冶金工业 | 5篇 |
原子能技术 | 1篇 |
自动化技术 | 11篇 |
出版年
2024年 | 1篇 |
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 5篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 13篇 |
2009年 | 11篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1990年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有133条查询结果,搜索用时 31 毫秒
1.
Nelaka Govinna Papatya Kaner Davette Ceasar Anita Dhungana Cody Moers Katherine Son Ayse Asatekin Peggy Cebe 《Polymer International》2019,68(2):231-239
Nonwoven super‐hydrophobic fiber membranes have potential applications in oil–water separation and membrane distillation, but fouling negatively impacts both applications. Membranes were prepared from blends comprising poly(vinylidene fluoride) (PVDF) and random zwitterionic copolymers of poly(methyl methacrylate) (PMMA) with sulfobetaine methacrylate (SBMA) or with sulfobetaine‐2‐vinylpyridine (SB2VP). PVDF imparts mechanical strength to the membrane, while the copolymers enhance fouling resistance. Blend composition was varied by controlling the PVDF‐to‐copolymer ratio. Nonwoven fiber membranes were obtained by electrospinning solutions of PVDF and the copolymers in a mixed solvent of N,N‐dimethylacetamide and acetone. The PVDF crystal phases and crystallinities of the blends were studied using wide‐angle X‐ray diffraction and differential scanning calorimetry (DSC). PVDF crystallized preferentially into its polar β‐phase, though its degree of crystallinity was reduced with increased addition of the random copolymers. Thermogravimetry (TG) showed that the degradation temperatures varied systematically with blend composition. PVDF blends with either copolymer showed significant increase of fouling resistance. Membranes prepared from blends containing 10% P(MMA‐ran‐SB2VP) had the highest fouling resistance, with a fivefold decrease in protein adsorption on the surface, compared to homopolymer PVDF. They also exhibited higher pure water flux, and better oil removal in oil–water separation experiments. © 2018 Society of Chemical Industry 相似文献
2.
A performance study of multiprocessor task scheduling algorithms 总被引:1,自引:0,他引:1
Multiprocessor task scheduling is an important and computationally difficult problem. A large number of algorithms were proposed
which represent various tradeoffs between the quality of the solution and the computational complexity and scalability of
the algorithm. Previous comparison studies have frequently operated with simplifying assumptions, such as independent tasks,
artificially generated problems or the assumption of zero communication delay. In this paper, we propose a comparison study
with realistic assumptions. Our target problems are two well known problems of linear algebra: LU decomposition and Gauss–Jordan
elimination. Both algorithms are naturally parallelizable but have heavy data dependencies. The communication delay will be
explicitly considered in the comparisons. In our study, we consider nine scheduling algorithms which are frequently used to
the best of our knowledge: min–min, chaining, A*, genetic algorithms, simulated annealing, tabu search, HLFET, ISH, and DSH with task duplication. Based on experimental results,
we present a detailed analysis of the scalability, advantages and disadvantages of each algorithm.
相似文献
Damla TurgutEmail: |
3.
Recent progress in energy harvesting technologies made it possible to build sensor networks with rechargeable nodes which target an indefinitely long operation. In these networks, the goal of energy management is to allocate the available energy such that the important performance metrics, such as the number of detected threats, are maximized. As the harvested energy is not sufficient for continuous operation, the scheduling of the active and inactive time is one of the main components of energy management. The active time scheduling protocols need to maintain the energy equilibrium of the nodes, while considering the uncertainties of the energy income, which is strongly influenced by the weather, and the energy expenditures, which are dependent on the behavior of the targets. In this paper, we describe and experimentally compare three active time scheduling protocols: (a) static active time, (b) dynamic active time based on a multi-parameter heuristic and (c) utility-based uniform sensing. We show that protocols which take into consideration the probabilistic models of the energy income and expenditure and can dynamically adapt to changes in the environment, can provide a significant performance advantage. 相似文献
4.
Lithium‐sulfur batteries have attracted much research interest because of their high theoretical energy density and low‐cost raw materials. While the electrodes are composed of readily available materials, the processes that occur within the cell are complex, and the electrochemical performance of these batteries is very sensitive to a number of cell processing parameters. Herein, a simple electrochemical model will be used to predict, with quantitative agreement, the electrochemical properties of lithium‐sulfur cathodes with varying carbon to sulfur ratios. The discharge capacity and the polarization were very similar for the lowest sulfur loadings, while above 23.2 wt% sulfur the gravimetric capacity dropped significantly, and there was an increase in the cell polarization. In addition, a transition in the electrode morphology, from well dispersed to aggregated sulfur at the surface, will be reflected in the change in a critical model parameter demonstrating the sensitivity and functionality of even this simple model in predicting complex behavior in the lithium‐sulfur cells. 相似文献
5.
The research goal of this study is to produce suitable scaffolds for tissue engineering applications. Different ratios of polyvinyl alcohol (PVA)/starch (90:10, 70:30, 50:50) and crosslinking methods have been used to prepare cryogels. Chemically crosslinked cryogels were synthesized using glutaraldehyde as the crosslinking agent. For the physically crosslinked cryogels, sodium dodecyl sulfate was used during cryogelation as the foaming agent. Chemical structure and pore morphology were demonstrated by Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). Swelling ratio and degradation profile of the scaffolds were also determined. 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide assay and SEM were used to investigate the biocompatibility of the scaffolds and cell morphology. Genotoxicity test was performed to show DNA fragmentation. The overall results demonstrated that PVA/starch cryogels could have potentially appealing application as scaffolds for tissue engineering applications and additives affect the architecture and characteristic properties of the cryogels. 相似文献
6.
Natural radioactivity of Cay?rhan lignite coal treated at Cay?rhan (Ankara, Turkey) power plant, its ash and soil samples mixed with ash in the power plant field were investigated. For comparison, soil samples were collected from a distance of 4 km south of the plant. The analysis shows that the samples include natural radionuclides such as 226Ra, 232Th and 40K. The mean activity concentrations of 226Ra, 232Th and 40K were 57.82, 30.45 and 322.21 Bq · kg−1, respectively. Obtained values shows that the average radium equivalent activity (Raeq), air-absorbed dose rate (D), annual effective dose (AED) and external hazard index (Hex) for all samples are 123.9 Bq · kg−1, 58.90 nGy · h−1, 71.99 μSv · y−1 and 0.34, respectively. The Raeq values of samples are lower than the limit of 370 Bq · kg−1, equivalent to a γ-dose of 1.5 mSv · y−1. The measured activity concentrations for these radionuclides were compared with the reported data of other countries. 相似文献
7.
8.
James?M.?Ma Samad?A.?Firdosy Richard?B.?Kaner Jean-Pierre?Fleurial Vilupanur?A.?RaviEmail author 《Journal of Materials Science》2014,49(3):1150-1156
Lanthanum telluride (La3?x Te4) is a state-of-the-art n-type high temperature thermoelectric material that behaves as a weak and brittle ceramic. Vickers microindentation hardness testing was explored as a rapid analysis technique to characterize the mechanical properties of this material. An indentation size effect was observed with hardness values ranging from 439 ± 31 kgf/mm2 (0.01 kgf/10 s contact time) to 335 ± 6 kgf/mm2 (0.5 kgf/10 s contact time). The Vickers indentation fracture toughness, K VIF, based on measurements of crack lengths emanating from the corners of the Vickers indents was 0.70 ± 0.06 MPa m1/2. 相似文献
9.
10.