全文获取类型
收费全文 | 159篇 |
免费 | 5篇 |
专业分类
化学工业 | 46篇 |
机械仪表 | 2篇 |
建筑科学 | 9篇 |
能源动力 | 2篇 |
轻工业 | 29篇 |
石油天然气 | 1篇 |
无线电 | 21篇 |
一般工业技术 | 25篇 |
冶金工业 | 4篇 |
自动化技术 | 25篇 |
出版年
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 15篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 8篇 |
2013年 | 9篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 6篇 |
2009年 | 9篇 |
2008年 | 5篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
排序方式: 共有164条查询结果,搜索用时 15 毫秒
31.
Fotios I. Gogoulos Anna Antonakopoulou Georgios V. Lioudakis Aziz S. Mousas Dimitra I. Kaklamani Iakovos S. Venieris 《Electronic Markets》2014,24(2):101-112
Business networking has substantially reshaped common enterprise procedures and has paved the way for the development of ground-breaking information sharing patterns and inter-organizational cooperative practices. Yet, critical issues still stand unaddressed; privacy and sensitive information confidentiality implications threaten to diminish the economic and social benefits derived from online collaboration. Nevertheless, privacy preservation refers to a multidimensional and cross-disciplinary subject, accompanied by both legal as well as technical challenges. In this context, this paper describes the design of a privacy-aware decision engine operating within synergistic contexts. Decision making regarding the production of authorizations and information usage rules is founded on a detailed privacy context and the enforcement of a deductive reasoning algorithm. The proposed reasoning process spans two distinct phases, taking into account an a priori perspective of the system while at the same time maintaining responsiveness in dynamic contexts. 相似文献
32.
Simpson Beauchamp C Dourou D Geornaras I Yoon Y Scanga JA Belk KE Smith GC Nychas GJ Sofos JN 《Journal of food science》2012,77(6):M343-M347
Studies examined the effects of meat-contact material types, inoculation substrate, presence of air at the liquid-solid surface interface during incubation, and incubation substrate on the attachment/transfer and subsequent biofilm formation by Escherichia coli O157:H7 on beef carcass fabrication surface materials. Materials studied as 2 × 5 cm coupons included stainless steel, acetal, polypropylene, and high-density polyethylene. A 6-strain rifampicin-resistant E. coli O157:H7 composite was used to inoculate (6 log CFU/mL, g, or cm(2)) tryptic soy broth (TSB), beef fat/lean tissue homogenate (FLH), conveyor belt-runoff fluids, ground beef, or beef fat. Coupons of each material were submerged (4 °C, 30 min) in the inoculated fluids or ground beef, or placed between 2 pieces of inoculated beef fat with pressure (20 kg) applied. Attachment/transfer of the pathogen was surface material and substrate dependent, although beef fat appeared to negate differences among surface materials. Beef fat was the most effective (P < 0.05) inoculation substrate, followed by ground beef, FLH, and TSB. Incubation (15 °C, 16 d) of beef fat-inoculated coupons in a beef fat homogenate (pH 4.21) allowed the pathogen to survive and grow on coupon surfaces, with maximal biofilm formation observed between 2 and 8 d of storage and when air was present at the liquid-solid interface. The results indicated that the process of fabricating beef carcasses may be conducive to the attachment of E. coli O157:H7 onto meat-contact surfaces and subsequent biofilm formation. Furthermore, it is recommended that substrates found in beef fabrication settings, rather than laboratory culture media, be used in studies designed to investigate E. coli O157:H7 biofilm development and control in these environments. PRACTICAL APPLICATION: Findings of this study provide knowledge on the effect of type of beef carcass fabrication surface material, fabrication-floor fluids and residues, and incubation conditions on attachment/transfer and subsequent biofilm formation by E. coli O157:H7. The results highlight the importance of thoroughly cleaning soiled surfaces to remove all remnants of beef fat or other organic material that may harbor or protect microbial contaminants during otherwise lethal antimicrobial interventions. 相似文献
33.
Patrick P. Naulleau Christopher N. Anderson Jerrin Chiu Paul Denham Simi George Kenneth A. Goldberg Michael Goldstein Brian Hoef Russ Hudyma Gideon Jones Chawon Koh Bruno La Fontaine Andy Ma Warren Montgomery Dimitra Niakoula Joo-on Park Tom Wallow Stefan Wurm 《Microelectronic Engineering》2009,86(4-6):448-455
Microfield exposure tools continue to play a dominant role in the development of extreme ultraviolet (EUV) resists. Here we present an update on the SEMATECH Berkeley 0.3-NA microfield exposure tool and summarize the latest test results from high-resolution line-space printing. Printing down to 20-nm is presented with large process latitude at 22-nm half-pitch lines. Also presented are line-edge roughness results along with a discussion of the importance of mask contributors to line-edge roughness measured in resist. Finally we briefly describe an upgrade to the tool that will enable EUV resist development at the 16-nm half-pitch node and beyond. (This paper was presented in MNE 2008 conference, <http://www.mne08.org>, <http://www.mne-conf.org>). 相似文献
34.
A high concentration of indole has been linked to ‘plastic-like’ off-flavour in wines, predominantly in wines produced under sluggish fermentation conditions. The purpose of this study was to determine the ability of yeast and bacteria to form indole and whether tryptophan was required for indole accumulation during winemaking. Wine-associated yeast and bacteria species (Saccharomyces cerevisiae, Saccharomyces bayanus, Candida stellata, Hanseniaspora uvarum, Kluyveromyces thermoloterans, Oenococcus oeni, Lactobacillus lindneri, Pediococcus cerevisiae and Pediococcus parvulus) were screened for their potential to generate indole during alcoholic or malolactic fermentation. Tryptophan was required for the accumulation of indole in chemically defined medium, and all yeast and bacteria fermentations were able to accumulate indole. C. stellata showed the greatest potential for indole formation (1033 μg/L) and among the bacteria, the highest concentration was generated by L. lindneri (370 μg/L). Whether primary fermentation is the principle cause of indole formation remains to be determined. We hypothesise that during an efficient fermentation, indole is removed through catabolic metabolism, but, when a sluggish fermentation arises, non-Saccharomyces species might produce excess indole that is still present by end of fermentation. 相似文献
35.
Bulk heterojunction solar cells were fabricated using the blend films of a porphyrin bearing pyridinylethynyl group (POR) as electron donor and PC60BM or PC70BM as electron acceptor. Photoluminescence measurement of the blend films of POR with fullerene derivatives indicated that charge transfer was possible between POR and fullerene derivatives. The solution processed bulk heterojunction solar cells using the blend of POR with PC60BM and PC70BM exhibit overall power conversion efficiency (PCE) of 1.96% and 2.54%, respectively. The PCE of the BHJ solar cell has been further improved up to 3.27% when thermally annealed POR:PC70BM was used as active layer, which is attributed mainly to the increase in short circuit current. The increase in Jsc is attributed to the enhanced crystallinity of the blend (particularly POR) and efficient π-electron conjugation of POR, resulting to an improvement in hole mobility, leading to more balance charge transport. The PCE of the device based on as cast POR:PC70BM has been further improved up to 4.06% when DMF treated PEDOT:PSS buffer layer was used. 相似文献
36.
Alevizaki Viktoria-Maria Anastasopoulos Markos Tzanakaki Anna Simeonidou Dimitra 《Photonic Network Communications》2020,40(3):209-220
Photonic Network Communications - To address the limitations of current radio access networks (RANs), centralized RANs adopting the concept of flexible splits of the BBU functions between radio... 相似文献
37.
G2MPLS is a Network Control Plane (NCP) architecture that implements the concept of Grid Network Services (GNS) required for implementing photonic Grids. It provides part of the functionalities related to the selection, co allocation and maintenance of both Grid and network resources through a set of seamless procedures at the user to network and inter domain boundaries. G2MPLS main features and procedures are presented in this document, as well as the considerations to deploy it and facilitate its dissemination. 相似文献
38.
Flow Routing and its Performance Analysis in Optical IP Networks 总被引:1,自引:0,他引:1
Optical packet-switching networks deploying buffering, wavelength conversion and multi-path routing have been extensively studied in recent years to provide high capacity transport for Internet traffic. However due to packet-based routing and switching, such a network could result in significant disorder and delay variation of packets when they are received by end users, thus increasing the burstiness of the Internet traffic and causing higher-layer protocol to malfunction. This paper addresses a novel routing and switching method for optical IP networks — flow routing, and its facilitating protocol. Flow routing deals with packet-flows to reduce flow corruption due to packet out-of-order, delay variation and packet loss, without using complicate control mechanism. Detailed performance analysis is given for output-buffered optical routers adopting flow routing. Two flow-oriented discarding techniques, i.e., flow discard (FD) and early flow discard (EFD), are discussed. Compared with optical packet-switching routers, a remarkable improvement of good-throughput is obtained in the optical flow-routers, especially under high congestion periods. We conclude that EFD behaves as a robust technique, which is more tolerant than FD to the change of traffic and transmission system factors. 相似文献
39.
Spiridon A Petropoulos Dimitra Daferera Moschos G Polissiou Harold C Passam 《Journal of the science of food and agriculture》2009,89(9):1534-1542
BACKGROUND: Turnip‐rooted parsley, a field‐crop of northern Europe, has recently been introduced to the Mediterranean region for fresh consumption or production of essential oil. Because of soil salinity within this area, the sensitivity of turnip‐rooted and two other parsley subspecies (plain‐ and curly‐leafed) to salt was studied. RESULTS: NaCl or CaCl2 additions to the irrigation water raised the electrical conductivity (EC) in increments from 0.5 dS m?1 to 4.5 dS m?1 (year 1) or 6.0 dS m?1 (year 2), reducing parsley foliage weight in year 2, but increasing the root weight of turnip‐rooted parsley in year 1. Raising the EC with NaCl increased the yield of foliar essential oil from curly‐leafed parsley (both years), but not from the other cultivars. CaCl2 had less effect on oil yield. The relative concentrations of the principal aroma constituents (β‐phellandrene, myristicin, β‐myrcene and apiole) of the foliar essential oil were affected by NaCl or CaCl2 in a way that differed between cultivars. Oil yield from parsley roots was very low and apparently unaffected by salinity. CONCLUSION: All three parsley subspecies are moderately sensitive to salinity, but may be cultivated at <4.5 dS m?1 EC. Salinity may assist oil production by increasing oil yield (curly‐leafed parsley) and positively affecting certain aroma constituents. Copyright © 2009 Society of Chemical Industry 相似文献
40.
Dimitra Dourou Anna C.S. Porto-Fett Brad Shoyer Jeffrey E. Call George-John E. Nychas Ernst K. Illg John B. Luchansky 《International journal of food microbiology》2009,130(3):245-250
The fate of Listeria monocytogenes, Salmonella Typhimurium, or Escherichia coli O157:H7 were separately monitored both in and on teewurst, a traditional raw and spreadable sausage of Germanic origin. Multi-strain cocktails of each pathogen (ca. 5.0 log CFU/g) were used to separately inoculate teewurst that was subsequently stored at 1.5, 4, 10, and 21 °C. When inoculated into commercially-prepared batter just prior to stuffing, in general, the higher the storage temperature, the greater the lethality. Depending on the storage temperature, pathogen levels in the batter decreased by 2.3 to 3.4, ca. 3.8, and 2.2 to 3.6 log CFU/g for E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, during storage for 30 days. When inoculated onto both the top and bottom faces of sliced commercially-prepared finished product, the results for all four temperatures showed a decrease of 0.9 to 1.4, 1.4 to 1.8, and 2.2 to 3.0 log CFU/g for E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, over the course of 21 days. With the possible exceptions for salt and carbohydrate levels, chemical analyses of teewurst purchased from five commercial manufacturers revealed only subtle differences in proximate composition for this product type. Our data establish that teewurst does not provide a favourable environment for the survival of E. coli O157:H7, S. Typhimurium, or L. monocytogenes inoculated either into or onto the product. 相似文献