全文获取类型
收费全文 | 479篇 |
免费 | 5篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 54篇 |
金属工艺 | 10篇 |
机械仪表 | 6篇 |
建筑科学 | 38篇 |
能源动力 | 24篇 |
轻工业 | 33篇 |
水利工程 | 5篇 |
石油天然气 | 2篇 |
无线电 | 30篇 |
一般工业技术 | 96篇 |
冶金工业 | 144篇 |
原子能技术 | 5篇 |
自动化技术 | 31篇 |
出版年
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2013年 | 32篇 |
2012年 | 21篇 |
2011年 | 18篇 |
2010年 | 26篇 |
2009年 | 15篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 9篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 14篇 |
2002年 | 8篇 |
2001年 | 9篇 |
2000年 | 14篇 |
1999年 | 9篇 |
1998年 | 33篇 |
1997年 | 21篇 |
1996年 | 16篇 |
1995年 | 24篇 |
1994年 | 14篇 |
1993年 | 6篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 6篇 |
1976年 | 10篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1968年 | 3篇 |
1967年 | 5篇 |
排序方式: 共有484条查询结果,搜索用时 31 毫秒
1.
To have market relevance and gain widespread market adoption, zero energy buildings (ZEBs) will need to be designed and constructed cost-effectively, and preferably without additional costs. An approach was developed to create low-energy buildings without additional construction costs such that it yielded innovation in building technology and integration by the market. A case study of the implementation of this method is presented to provide a data point that ZEBs can be built with zero cost increase. Documenting cost-control best practices and packaging those strategies for adoption by the commercial building sector will help make the business case for ZEBs for mainstream construction and promote market uptake of the innovative technologies and design approaches needed. The holistic implementation of cost-control strategies will enable ZEBs to be designed and constructed on a typical budget. The current state of ZEB economics is evaluated and a path forward is proposed for greater market penetration of ZEBs. By demonstrating how to combine ZEB technologies and design approaches into an overall efficiency package that can be implemented at minimal (zero, in certain cases) incremental capital cost, the domain of ZEB design and construction can be expanded from a niche market to the commercial construction mainstream. 相似文献
2.
3.
Jie DuanmuE. Kristofer Gamstedt Andrey PranovichAri Rosling 《Composites Science and Technology》2011,71(4):520-527
In the present work dough moulding compound premixes of allyl glycidyl ether modified (AGE)-potato starch, (DS) = 0.2, has been prepared and tested for its fiber reinforced composite properties. The AGE-starch was hydrolyzed with α-amylase under neutral condition for 6 h at 45 °C for improved process ability. The grafting and hydrolytic scission was confirmed by nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC), respectively. Homogeneous composite premixes of AGE-starch, wood fibers, various amount of glycerol and ethylene glycol dimethacrylate were successfully mixed with a Brabender-kneader at 55 °C and cured by compression molding at 150 °C using 2 wt% of dibenzoyl peroxide. Adding 5 wt% of glycerol did not reduce the ultimate strength of the composites; 10% glycerol reduced the strength from 60 MPa to 40 MPa, and 16% glycerol to 14 MPa. The results with 5 wt% glycerol are comparable with earlier achieved results. The water absorption rate increased with increased glycerol content and the mechanical strength of the composites was lost completely when the moisture uptake reached 15 wt%. 相似文献
4.
Rana Sabouni Aidan Leach Cedric Briens Franco Berruti 《American Institute of Chemical Engineers》2011,57(12):3344-3350
In this work, it was found that spray nozzles pulsations greatly improved the liquid feed spray distribution on fluidized bed particles. Pulsating a spray nozzle doubled its nozzle performance index at various operating conditions. The objective of this study was to impose fluctuations of well‐defined frequency and amplitude on the liquid spray to investigate potentially beneficial effects of fluctuations on the liquid feed distribution on the particles in the fluidized bed. Three sets of experiments were conducted to study the quality of the spray jet‐bed interaction using a conductance probe method. The jet penetration for each experiment was calculated theoretically. © 2011 American Institute of Chemical Engineers AIChE J, 2011 相似文献
5.
Julie I. Jay Shetha Shukair Kristofer Langheinrich Melissa C. Hanson Gianguido C. Cianci Todd J. Johnson Meredith R. Clark Thomas J. Hope Patrick F. Kiser 《Advanced functional materials》2009,19(18):2969-2977
Materials that respond to physiological stimuli are important in developing advanced biomaterials for modern therapies. The reversibility of covalent crosslinks formed by phenylboronate (PBA) and salicylhydroxamate (SHA) has been exploited to provide a pH‐responsive gel for application to the vaginal tract. Dynamic rheology reveals that the gel frequency‐dependent viscoelastic properties are modulated by pH. At pH 4.8 the viscous component dominates throughout most of the frequency range. As the pH increases, the characteristic relaxation time continues to increase while the G′Plateau levels off above pH 6. At pH 7.5, the elastic component dominates throughout the frequency sweep and is predominately independent of frequency. Particle tracking assesses the transport of both fluorescently labeled HIV‐1 and 100‐nm latex particles in the PBA–SHA crosslinked gel as a function of pH. At pH 4.8 the ensemble‐averaged mean squared displacement at lag times greater than three seconds reveals that transport of the HIV‐1 and 100‐nm particles becomes significantly impeded by the matrix, exhibiting diffusion coefficients less than 0.0002 µm2 s?1. This pH‐responsive gel thus displays properties that have the potential to significantly reduce the transport of HIV‐1 to susceptible tissues and thus prevent the first stage of male‐to‐female transmission of HIV‐1. 相似文献
6.
7.
Cyril Caminade Jolyon M. Medlock Els Ducheyne K. Marie McIntyre Steve Leach Matthew Baylis Andrew P. Morse 《Journal of the Royal Society Interface》2012,9(75):2708-2717
The Asian tiger mosquito (Aedes albopictus) is an invasive species that has the potential to transmit infectious diseases such as dengue and chikungunya fever. Using high-resolution observations and regional climate model scenarios for the future, we investigated the suitability of Europe for A. albopictus using both recent climate and future climate conditions. The results show that southern France, northern Italy, the northern coast of Spain, the eastern coast of the Adriatic Sea and western Turkey were climatically suitable areas for the establishment of the mosquito during the 1960–1980s. Over the last two decades, climate conditions have become more suitable for the mosquito over central northwestern Europe (Benelux, western Germany) and the Balkans, while they have become less suitable over southern Spain. Similar trends are likely in the future, with an increased risk simulated over northern Europe and slightly decreased risk over southern Europe. These distribution shifts are related to wetter and warmer conditions favouring the overwintering of A. albopictus in the north, and drier and warmer summers that might limit its southward expansion. 相似文献
8.
Electricity storage systems (ESS) for bulk energy storage are principally used for load levelling purposes or for relieving the intermittency of renewables. Another use is electricity arbitrage through the rule of ‘buy low, sell high’. This operation tracks the market‐clearing price (MCP) profiles and produces profit by exploiting the differences between peak and off‐peak prices. The profits made in this way depend on technology characteristics and the market competition level. We investigate the influence of demand‐side management (DSM) on ESS profitability when the only income is from provision of electricity arbitrage services, by optimizing the time allocation of the charge and discharge operations. Two scenarios of DSM in the market have been selected for two management periods (MP): 1 day and 3 days. The longer MP is examined in order to investigate the potential for higher economic value when energy transfer to the next day is permitted. The key finding is that a very small load shifting from peaks to off‐peaks, due to DSM, significantly affects the ESS profit. The significant profit losses the ESS showed are a result of the high capital costs and the small difference of the peak and off‐peak electricity prices in the Greek market. Therefore, under the assumptions we have made for this research, any attempt to use ESS in ‘buy low, sell high’ operation is not profitable. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
9.
G. J. Rogan Y. A. Dudin T. C. Lee K. M. Magin J. D. Astwood N. S. Bhakta J. N. Leach P. R. Sanders R. L. Fuchs 《Food Control》1999,10(6):421-414
We have developed immunological-based detection methods to support labeling of protein-containing food fractions derived from Roundup Ready® soybeans. Western blotting and enzyme linked immunosorbent assay (ELISA) procedures were developed to measure the 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) protein derived from the Agrobacterium sp. strain CP4 in the major processed fractions derived from Roundup Ready soybean. Expression of the CP4 EPSPS protein confers tolerance to Roundup® herbicide. The western blotting method utilizes a polyclonal goat anti-CP4 EPSPS antibody which specifically binds to CP4 EPSPS followed by detection of bound goat antibody with biotinylated Protein-G. Detection of this complex is accomplished using horseradish-peroxidase (HRP) labeled NeutrAvidin™ and signal development by enhanced chemiluminesence. Data from western blot analyses of these fractions establish that stable epitopes remain after the seed has been subjected to processing conditions typically employed by the food industry, thereby enabling development of an ELISA method. The ELISA for measurement of CP4 EPSPS is a triple antibody sandwich procedure utilizing a monoclonal capture antibody and a polyclonal detection antibody followed by a third biotin labeled monoclonal anti-rabbit antibody. Sandwich formation is detected using HRP labeled NeutrAvidin™ with color development using TMB substrate. In the sandwich ELISA, the immunological activity of CP4 EPSPS was reduced by the extraction method required to solubilize CP4 EPSPS protein from processed fractions. Sensitivity of the CP4 EPSPS ELISA was sufficient to detect CP4 EPSPS protein in processed soybean fractions that contained 2% Roundup Ready soybean mixed with conventional processed soybean fractions, thereby making the ELISA an acceptable method to assess CP4 EPSPS protein in processed soybean fractions. Data on sensitivity, accuracy, precision and specificity, established that the western blot and ELISA methods are appropriate for compliance with the EC Novel Foods Regulation. 相似文献
10.
H. Takeda H. Harinaka T. Shiosaki M.A. Zubair C. Leach R. Freer T. Hoshina T. Tsurumi 《Journal of the European Ceramic Society》2010,30(2):555-559
BaTiO3–(Bi1/2K1/2)TiO3 (BT–BKT) ceramics have a low ρRT of 101–102 Ω cm like that of semiconducting materials prepared by sintering in a N2 flow with low O2 concentration. By annealing in air, the BT–BKT ceramics show an abrupt increase in their resistivity near the Tc, namely, a positive temperature coefficient of resistivity (PTC) characteristic. With 5 mol% and 10 mol% BKT added to BT, the ceramics display the PTC characteristic at 155 °C and 165 °C, respectively. Furthermore, the ratio, ρmax/ρRT, of the highest resistivity (ρmax) and the resistivity at room temperature (ρRT) of the ceramics increased on adding a small amount of Mn and a sintering aid. 相似文献