全文获取类型
收费全文 | 80篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
化学工业 | 15篇 |
金属工艺 | 3篇 |
建筑科学 | 7篇 |
能源动力 | 5篇 |
轻工业 | 3篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 17篇 |
一般工业技术 | 13篇 |
冶金工业 | 14篇 |
自动化技术 | 7篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2002年 | 3篇 |
2000年 | 3篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有86条查询结果,搜索用时 15 毫秒
11.
Design and Validation of an Efficient Authentication Scheme with Anonymity for Roaming Service in Global Mobility Networks 总被引:1,自引:1,他引:0
Daojing He Sammy Chan Chun Chen Jiajun Bu Rong Fan 《Wireless Personal Communications》2011,61(2):465-476
Designing a user authentication protocol with anonymity for the global mobility network (GLOMONET) is a difficult task because
wireless networks are susceptible to attacks and each mobile user has limited power, processing and storage resources. In
this paper, a secure and lightweight user authentication protocol with anonymity for roaming service in the GLOMONET is proposed.
Compared with other related approaches, our proposal has many advantages. Firstly, it uses low-cost functions such as one-way
hash functions and exclusive-OR operations to achieve security goals. Having this feature, it is more suitable for battery-powered
mobile devices. Secondly, it uses nonces instead of timestamps to avoid the clock synchronization problem. Therefore, an additional
clock synchronization mechanism is not needed. Thirdly, it only requires four message exchanges between the user, foreign
agent and home agent. Further, the security properties of our protocol are formally validated by a model checking tool called
AVISPA. We also demonstrate that this protocol enjoys important security attributes including prevention of various attacks,
single registration, user anonymity, no password table, and high efficiency in password authentication. Security and performance
analyses show that compared with other related authentication schemes, the proposed scheme is more secure and efficient. 相似文献
12.
In this paper, we propose a new architecture for multicast ATM switches with fault tolerant capability based on the Clos–Knockout switch. In the new architecture, each stage has one more redundant switch module. If one switch module is faulty, the redundant module would replace the faulty one. On the other hand, under the fault‐free condition, the redundant modules in the second and third stages will provide additional alternative internal paths, and hence improve the performance. The performance analysis shows that the cell loss probability is lower than the original architecture when all modules are fault free, and the reliability of the original architecture is improved. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
13.
Perone Sammy; Madole Kelly L.; Ross-Sheehy Shannon; Carey Maeve; Oakes Lisa M. 《Canadian Metallurgical Quarterly》2008,44(5):1242
The authors examined the relation between infants' motor skills and attention to objects features in events in which a hand acted on an object (e.g., squeezed it) that then produced a sound (e.g., squeaking). In this study, 6- to 7-month-old infants (N = 41) were habituated to a single event and then tested with changes in appearance and action. Infants robustly responded to changes in action, but as a group did not respond to changes in appearance. Moreover, more skilled activity with objects during naturalistic play was associated with longer looking in response to a change in appearance, but not to a change in action. Implications for the relation between perception and action in infancy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
Ho I-Ting Chang Kai-Chun Tiparti Dhruv Yeh An-Chou Tin Sammy 《Metallurgical and Materials Transactions A》2023,54(1):23-38
Metallurgical and Materials Transactions A - This investigation rationalizes the impact of oxide particles on the melt pool and subsequent formation of microstructure in superalloy Inconel 718... 相似文献
15.
Stoichko Antonov Jiajie Huo Qiang Feng Dieter Isheim David N. Seidman Eugene Sun Sammy Tin 《Metallurgical and Materials Transactions A》2018,49(3):729-739
Boron additions to Ni-based superalloys are considered to be beneficial to the creep properties of the alloy, as boron has often been reported to increase grain boundary cohesion, increase ductility, and promote the formation of stable boride phases. Despite the importance, it is not well understood whether these improvements are associated with the presence of elemental boron or stable borides along the grain boundaries. In this investigation, two experimental powder-processed Ni-based superalloys containing elevated levels of Nb were found to exhibit increased solubility for B in the γ matrix when compared to similar commercial Ni-based superalloys. This resulted in an overall lower B concentration at grain boundaries that suppressed boride formation. As the predictive capability of CALPHAD database models for Ni-based superalloys have improved over the years, some discrepancies may still persist around compositionally heterogeneous features such as grain boundaries. Improved quantification of the characteristic partitioning of B as a function of the bulk alloy composition is required for understanding and predicting the stability of borides. 相似文献
16.
In Mozambique, domestic energy is often composed of a mix of sources, primarily used for lighting and cooking, with biomass and kerosene as more common sources. Electrification programs, intended to connect new consumers countrywide, have not significantly contributed either to the intensification of electricity consumption or to the reduction of the use of biomass in households. The choice of energy source is dependent on price and on the capability of the household to invest in energy-consuming appliances. Based on the data from a household survey carried out in Mozambique during 2002/03, this paper analyzes the geographic differences in unit expenditures for domestic energy and finds evidence of an inverted energy ladder with prices of useful energy units. The data show that biomass sources are often more expensive per unit of useful energy than higher-grade sources, supporting arguments favoring electrification as a poverty alleviation strategy. In addition, this study estimates the likelihood of poor households transitioning from biomass to electricity consumption based on various factors. Results indicate that income is not a determining factor in the transition, but wealth and the level of the Primary Energy Consumption Share (PECS) are as important factors as the nature of the energy mix. 相似文献
17.
Qianying Shi Xianfei Ding Meiling Wang Yunrong Zheng Jianping He Sammy Tin Qiang Feng 《Metallurgical and Materials Transactions A》2014,45(4):1833-1843
The effect of Co on the as-cast and heat-treated microstructures was investigated in two experimental Ni-based single-crystal superalloys containing low levels of Re and Ru. The experimental results indicated that increasing the Co content from 7.9 to 15.8 wt pct decreased the volume fraction of (γ + γ′) eutectic and the solidification segregation ratio of W. High levels of Co additions were also found to decrease the solvus temperatures of the γ′ phase and (γ + γ′) eutectic as well as the solidus temperature. During the long-term thermal exposure at 1373 K (1100 °C), no TCP phases precipitated in either alloy. However, the coarsening and coalescence of γ′ precipitates in the alloy containing 15.8 wt pct Co was slower than that in the other alloy with 7.9 wt pct Co. In the current study, high levels of Co additions decreased the equilibrium volume fraction of γ′ phase, leading to a change in the partitioning ratios of TCP-forming elements Cr, Mo, Re, and W between the γ and γ′ phases. This change resulted in a lower degree of elemental supersaturation in the γ matrix and improved the phase stability of the γ/γ′ microstructure. These experimental results were then compared with those obtained from multi-component thermodynamic calculations, and good agreement was observed. 相似文献
18.
Thomas Kozmel Edward Y. Chen Charlie C. Chen Sammy Tin 《Metallurgical and Materials Transactions A》2014,45(5):2590-2600
Recent efforts have focused on the development of novel manufacturing processes capable of producing microstructures dominated by sub-micron grains. For structural applications, grain refinement has been shown to enhance mechanical properties such as strength, fatigue resistance, and fracture toughness. Through control of the thermo-mechanical processing parameters, dynamic recrystallization mechanisms were used to produce microstructures consisting of sub-micron grains in 9310 steel. Starting with initial bainitic grain sizes of 40 to 50 μm, various levels of grain refinement were observed following hot deformation of 9310 steel samples at temperatures and strain rates ranging from 755 K to 922 K (482 °C and 649 °C) and 1 to 0.001/s, respectively. The resulting deformation microstructures were characterized using scanning electron microscopy and electron backscatter diffraction techniques to quantify the extent of carbide coarsening and grain refinement occurring during deformation. Microstructural models based on the Zener–Holloman parameter were developed and modified to include the effect of the ferrite/carbide interactions within the system. These models were shown to effectively correlate microstructural attributes to the thermal mechanical processing parameters. 相似文献
19.
Warren P. McPherson Neil R. FosterDavid W. Hastings John R. KalmanKiyofumi Okada Sammy Heng 《Fuel》1985
Secondary vitroplast, produced by treating a Liddell vitrinite concentrate with tetralin in a continuous flow, packed-bed microreactor under a nitrogen pressure of 13.8 MPa at 360, 410 and 460 °C, has been analysed by i.r. spectroscopy, gel permeation chromatography, solid state 13C n.m.r. and reflectance microscopy. Results showed that this intermediate in the liquefaction process had the same carbon aromaticity as the untreated vitrinite concentrate and that both its aromaticity and reflectance were independent of the temperature of formation. It was concluded that the initial solution of the vitrinite concentrate in tetralin involved no significant hydrogenation of the vitrinite. 相似文献
20.
Channelization of streams associated with floodplain forested wetlands has occurred extensively throughout the world and specifically in the southeastern United States. Channelization of fluvial systems alters the hydrologic and sedimentation processes that sustain these systems. In western Tennessee, channelization and past land‐use practices have caused drastic geomorphic and hydrologic changes, resulting in altered habitat conditions that may affect avian communities. The objective of this study was to determine if there were differences in avian communities utilizing floodplain forests along unchannelized streams compared to channelized streams with valley plugs, areas where sediment has completely filled the channel. During point count surveys, 58 bird species were observed at unchannelized sites and 60 species were observed at valley plug sites. Species associated with baldcypress‐tupelo (Taxodium‐Nyssa) swamps (e.g. Great Egret (Ardea albus) and Black‐crowned Night Heron (Nycticorax nycticorax)) and mature hardwood forests with open midstories (e.g. Eastern Wood‐Pewee (Contopus virens), Yellow‐throated Vireo (Vireo flavifrons), Cerulean Warbler (Dendroica cerulea) and Scarlet Tanager (Piranga olivacea)) were either only found at unchannelized sites or were more abundant at unchannelized sites. Conversely, species associated with open and early successional habitats (e.g. Tree Swallow (Tachycineta bicolor), Northern Mockingbird (Mimus polyglottos) and Blue Grosbeak (Passerina caerulea)) were either only found at valley plug sites or were more abundant at valley plug sites. Results of habitat modelling suggest that the habitat characteristics of floodplain forests at unchannelized sites are more suitable for Neotropical migrant bird species of conservation concern in the region than at valley plug sites. This study, in combination with previous research, demonstrates the ecological impacts of valley plugs span across abiotic and biotic processes and tropic levels. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献