全文获取类型
收费全文 | 328篇 |
免费 | 19篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 76篇 |
金属工艺 | 2篇 |
机械仪表 | 4篇 |
建筑科学 | 18篇 |
矿业工程 | 1篇 |
能源动力 | 35篇 |
轻工业 | 20篇 |
水利工程 | 8篇 |
无线电 | 41篇 |
一般工业技术 | 35篇 |
冶金工业 | 3篇 |
原子能技术 | 1篇 |
自动化技术 | 98篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 18篇 |
2021年 | 17篇 |
2020年 | 7篇 |
2019年 | 15篇 |
2018年 | 15篇 |
2017年 | 17篇 |
2016年 | 11篇 |
2015年 | 11篇 |
2014年 | 11篇 |
2013年 | 24篇 |
2012年 | 29篇 |
2011年 | 38篇 |
2010年 | 19篇 |
2009年 | 23篇 |
2008年 | 11篇 |
2007年 | 22篇 |
2006年 | 9篇 |
2005年 | 2篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1987年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有347条查询结果,搜索用时 15 毫秒
31.
Alexandros Gasparatos Mohamed El-Haram Malcolm Horner 《Renewable & Sustainable Energy Reviews》2009,13(5):1074-1081
This paper provides a concise overview of the influence of human activity within the UK society on resource consumption and the subsequent effects on the environment. The concept of the Multi Scale Integrated Analysis of Societal Metabolism (MSIASM) is applied in order to elucidate the evolution of the UK economy for the period between 1981 and 2004. Our findings highlight the transition to a service-based economy and the disproportionate increase of energy demand when compared to the overall population increase. Emergy synthesis is applied in order to understand the production and consumption patterns and the environmental support required to sustain human activity within the UK for the year 2004. Generally speaking the UK society greatly benefits from its significant natural resources with 44.3% of the total emergy used coming from home sources and 29.1% from locally renewable sources. Interestingly enough, despite its significant natural resources, the UK economy, seems to be a net emergy importer by 638.5 × 1021 seJ. Furthermore, the current economic activity is believed to have a significant impact in the environment despite the relatively low environmental load ratio of 2.44. 相似文献
32.
Mohammad Nahid Siddiqui Dimitris S. Achilias Halim Hamid Redhwi Dimitris N. Bikiaris Konstantinos–Alexandros G. Katsogiannis George P. Karayannidis 《大分子材料与工程》2010,295(6):575-584
Recycling of PET was examined using hydrolytic depolymerization in an alkaline solution under microwave irradiation. The reaction was carried out in a sealed microwave reactor in which the pressure and temperature were controlled and recorded. The main products were the monomers TPA and EG. The effect of reaction temperature, time, amount of PET and alkaline concentration on the degree of PET depolymerization and TPA recovery was investigated. Microwave irradiation was found to reduce the time needed to achieve a specific degradation of PET significantly, with almost complete depolymerization occurring in 30 min at 180 °C and only 46 W of microwave power. Using a phase transfer catalyst (TOMAB) resulted in the same amount of unreacted PET but at significantly lower depolymerization temperatures.
33.
Kostas Tsagkaris Gerard Nguengang Aristi Galani Imen Grida Ben Yahia Majid Ghader Alexandros Kaloxylos Markus Gruber Apostolis Kousaridas Mathieu Bouet Stylianos Georgoulas Aimilia Bantouna Nancy Alonistioti Panagiotis Demestichas 《International Journal of Network Management》2013,23(6):402-423
Academic and industrial research initiatives have sought to make fully autonomic networks a reality. Some of these initiatives pursued a holistic approach, while others focused on setting up functionalities for specific networking domains. These efforts did not succeed in being extensively deployed, because the goals of network operators were not satisfactorily met. These goals include unification of management operations, enablement of end‐to‐end management and enhancement of the overall system performance in a trusted way, while reducing management cost. In this paper, we analyse a set of existing autonomic management architectures and frameworks with respect to a selected set of criteria. We then identify missing parts and challenges and propose a framework to unify the most promising attributes towards a novel approach of realization of autonomic networking management. We call this proposal Unified Management Framework (UMF). Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
34.
Pappalardo G Amodeo A Pandolfi M Wandinger U Ansmann A Bösenberg J Matthias V Amiridis V De Tomasi F Frioud M Larlori M Komguem L Papayannis A Rocadenbosch F Wang X 《Applied optics》2004,43(28):5370-5385
An intercomparison of the algorithms used to retrieve aerosol extinction and backscatter starting from Raman lidar signals has been performed by 11 groups of lidar scientists involved in the European Aerosol Research Lidar Network (EARLINET). This intercomparison is part of an extended quality assurance program performed on aerosol lidars in the EARLINET. Lidar instruments and aerosol backscatter algorithms were tested separately. The Raman lidar algorithms were tested by use of synthetic lidar data, simulated at 355, 532, 386, and 607 nm, with realistic experimental and atmospheric conditions taken into account. The intercomparison demonstrates that the data-handling procedures used by all the lidar groups provide satisfactory results. Extinction profiles show mean deviations from the correct solution within 10% in the planetary boundary layer (PBL), and backscatter profiles, retrieved by use of algorithms based on the combined Raman elastic-backscatter lidar technique, show mean deviations from solutions within 20% up to 2 km. The intercomparison was also carried out for the lidar ratio and produced profiles that show a mean deviation from the solution within 20% in the PBL. The mean value of this parameter was also calculated within a lofted aerosol layer at higher altitudes that is representative of typical layers related to special events such as Saharan dust outbreaks, forest fires, and volcanic eruptions. Here deviations were within 15%. 相似文献
35.
Pierre Santucci Christina Dedaki Alexandros Athanasoulis Laura Gallorini Anaïs Munoz Dr. Stéphane Canaan Dr. Jean-François Cavalier Dr. Victoria Magrioti 《ChemMedChem》2019,14(3):349-358
In the quest for new antibacterial agents, a series of novel long- and medium-chain mono- and disubstituted β-lactones was developed. Their activity against three pathogenic mycobacteria—M. abscessus, M. marinum, and M. tuberculosis—was assessed by the resazurin microtiter assay (REMA). Among the 16 β-lactones synthesized, only 3-hexadecyloxetan-2-one (VM005) exhibited promising activity against M. abscessus, whereas most of the β-lactones showed interesting activities against M. marinum, similar to that of the classical antibiotic, isoniazid. Regarding M. tuberculosis, six compounds were found to be active against this mycobacterium, with β-lactone VM008 [trans-(Z)-3-(hexadec-7-en-1-yl)-4-propyloxetan-2-one] being the best growth inhibitor. The promising antibacterial activities of the best compounds in this series suggest that these molecules may serve as leads for the development of much more efficient antimycobacterial agents. 相似文献
36.
37.
This paper aims at analysing the factors, which motivate communities to resist the installation of wind farms in their vicinity. To this end, the choice experiment methodology was employed in communities in two Greek Aegean Islands to assess the determinants of preferences towards different wind-farm projects. Unlike other studies, the willingness to accept welfare measure was adopted. The results of our analysis show that the conservation status of the area where the wind farms are to be installed, along with the governance characteristics of the planning procedure are the most important determinants of local community welfare in relation to wind farms. In contrast to other studies, we find that the physical attributes of wind farms appear to be of less relative importance from a local community welfare point of view. Implications for the EU's future energy policy are drawn. 相似文献
38.
Enass K. Abo‐Hamed Timothy Pennycook Yana Vaynzof Chris Toprakcioglu Alexandros Koutsioubas Oren A. Scherman 《Small (Weinheim an der Bergstrasse, Germany)》2014,10(15):3145-3152
Late transition metal nanoparticles (NPs) with a favorably high surface area to volume ratio have garnered much interest for catalytic applications. Yet, these NPs are prone to aggregation in solution, which has been mitigated through attachment of surface ligands, additives or supports; unfortunately, protective ligands can severely reduce the effective surface area on the NPs available for catalyzing chemical transformations. The preparation of ‘metastable’ NPs can readily address these challenges. We report herein the first synthesis of monodisperse metastable ruthenium nanoparticles (RuNPs), having sub 5 nm size and an fcc structure, in aqueous media at room temperature, which can be stored for a period of at least 8 months. The RuNPs can subsequently be used for the catalytic, quantitative hydrolysis of ammonia‐borane (AB) yielding hydrogen gas with 21.8 turnovers per min at 25 °C. The high surface area available for hydrolysis of AB on the metastable RuNPs translated to an Ea of 27.5 kJ mol‐1, which is notably lower than previously reported values for RuNP based catalysts. 相似文献
39.
Turro E Giannis A Cossu R Gidarakos E Mantzavinos D Katsaounis A 《Journal of hazardous materials》2011,190(1-3):460-465
The electrochemical oxidation of stabilized landfill leachate with 2960 mg L(-1) chemical oxygen demand (COD) over a Ti/IrO(2)-RuO(2) anode was investigated in the presence of HClO(4) as the supporting electrolyte. Emphasis was given on the effect of electrolysis time (up to 240 min) and temperature (30, 60 and 80°C), current density (8, 16 and 32 mA cm(-2)), initial effluent's pH (0.25, 3, 5 and 6), HClO(4) concentration (0.25 and 1M) and the addition of NaCl (20 and 100mM) or Na(2)SO(4) (20mM) as source of extra electrogenerated oxidants on performance; the latter was evaluated regarding COD, total carbon (TC), total phenols (TPh) and color removal. Moreover, the anode was studied by scanning electron microscopy and cyclic voltammetry. The main parameters affecting the process were the effluent's pH and the addition of salts. Treatment for 240 min at 32 mA cm(-2) current density, 80°C and the pH adjusted from its inherent value of 0.25 (i.e. after the addition of HClO(4)) to 3 yielded 90% COD, 65% TC and complete color and TPh removal at an electricity consumption of 35 kWh kg(-1) COD removed. Comparable performance (i.e. 75% COD reduction) could be achieved without pH adjustment but with the addition of 100mM NaCl consuming 20 kWh kg(-1) COD removed. 相似文献
40.
Klaus Nolte Alexandros Kaloxylos Kostas Tsagkaris Thomas Rosowski Makis Stamatelatos Aristi Galani Eckard Bogenfeld Panagis Magdalinos Jens Tiemann Jens Gebert Paul Arnold Dirk von Hugo Nancy Alonistioti Panagiotis Demestichas Wolfgang Koenig 《International Journal of Network Management》2011,21(5):360-383
Future mobile networks are expected to be complex heterogeneous systems. On the one hand this will enable users to take advantage of a number of different access technologies. On the other hand it will seriously affect network management procedures since more extensive operations and decisions will have to be dealt with. To tackle these challenges a number of new dynamic mechanisms need to be designed. It is imperative that certain network management tasks have to be performed without human intervention to reduce the OPEX costs and achieve faster responses in different events. To achieve this goal, the introduction of self‐x functionalities, combined with cognitive mechanisms and the ability to reconfigure network entities and terminals, is required. Moreover, the introduction of a new pilot channel needs to be considered to assist the terminals in selecting the most suitable radio access technology according to their requirements. We present the functional architecture of an evolved network that was designed in the context of the EU‐funded IP project ‘E3: End‐to‐End Efficiency’. This architecture aims to enhance existing procedures usually performed in traditional operation and maintenance systems (e.g. spectrum management, network planning, configuration actions). We explain the rationale of our design and provide specific examples to illustrate the role of the different functional entities and their interfaces. A considerable part of this architecture has recently been approved as a feasibility study by the ETSI Committee Reconfigurable Radio System. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献