全文获取类型
收费全文 | 324篇 |
免费 | 31篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 108篇 |
机械仪表 | 2篇 |
建筑科学 | 30篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 73篇 |
水利工程 | 6篇 |
石油天然气 | 2篇 |
无线电 | 14篇 |
一般工业技术 | 54篇 |
冶金工业 | 4篇 |
原子能技术 | 1篇 |
自动化技术 | 53篇 |
出版年
2023年 | 5篇 |
2022年 | 23篇 |
2021年 | 24篇 |
2020年 | 15篇 |
2019年 | 21篇 |
2018年 | 11篇 |
2017年 | 23篇 |
2016年 | 22篇 |
2015年 | 14篇 |
2014年 | 15篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 22篇 |
2010年 | 21篇 |
2009年 | 9篇 |
2008年 | 19篇 |
2007年 | 17篇 |
2006年 | 12篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有355条查询结果,搜索用时 0 毫秒
91.
Implementing Equitable Water Allocation in Transboundary Catchments: The Case of River Nestos/Mesta 总被引:3,自引:1,他引:2
Eleni Kampragou Eleni Eleftheriadou Yannis Mylopoulos 《Water Resources Management》2007,21(5):909-918
Border areas comprise inevitably problematic fields especially when the countries are bound to share common water resources.
The conflict potential is rather high and quite often countries are directed to the negotiation table in order to form tranboundary
agreements. These agreements aim to the settlement of tensions and conflicts originating from the management of shared water
resources. Often a starting point of the conflict resolution is the water allocation scheme between the interested parts.
The definition of entitlements over shared water resources in not an easy task and it requires the use of specific decision
tools in order to reach the maximum level of objectivity. According to the Water Framework Directive (WFD) 2000/60, management
of transboundary catchments shall be based on existing structures set by international agreements, such as the UN Convention
on the Protection and Use of Transboundary Watercourses and International Lakes. The main aim of this paper is the implementation
of a water allocation tool based on representative indicators characterizing the involved parties while placing emphasis on
environmental protection. The variables used are proposed by the UN Convention on the Law of the Non-navigational Uses of
International Watercourses incorporating both natural and socio-economic aspects. These factors are quantified for each country
and a weight factor is assigned to each one depending on its importance and suitability for describing the environmental and
socio-economic situation in each country. As an illustration example the transboundary river Nestos/Mesta case is presented. 相似文献
92.
Maximilian Moser Johannes Gladisch Sarbani Ghosh Tania Cecilia Hidalgo James F. Ponder Jr. Rajendar Sheelamanthula Quentin Thiburce Nicola Gasparini Andrew Wadsworth Alberto Salleo Sahika Inal Magnus Berggren Igor Zozoulenko Eleni Stavrinidou Iain McCulloch 《Advanced functional materials》2021,31(26):2100723
Electrochemically induced volume changes in organic mixed ionic-electronic conductors (OMIECs) are particularly important for their use in dynamic microfiltration systems, biomedical machinery, and electronic devices. Although significant advances have been made to maximize the dimensional changes that can be accomplished by OMIECs, there is currently limited understanding of how changes in their molecular structures impact their underpinning fundamental processes and their performance in electronic devices. Herein, a series of ethylene glycol functionalized conjugated polymers is synthesized, and their electromechanical properties are evaluated through a combined approach of experimental measurements and molecular dynamics simulations. As demonstrated, alterations in the molecular structure of OMIECs impact numerous processes occurring during their electrochemical swelling, with sidechain length shortening decreasing the number of incorporated water molecules, reducing the generated void volumes and promoting the OMIECs to undergo different phase transitions. Ultimately, the impact of these combined molecular processes is assessed in organic electrochemical transistors, revealing that careful balancing of these phenomena is required to maximize device performance. 相似文献
93.
94.
Nikolaos Gougoulias Ioannis Vagelas Ioannis Vasilakoglou Fotios Gravanis Aida Louka Eleni Wogiatzi Professor Nikolaos Chouliaras 《Journal of the science of food and agriculture》2010,90(2):286-290
BACKGROUND: Oregano essential oil and neem have been reported to be effective against soil‐borne pathogens and nematodes. The possibility of having an effect on soil properties was the aim of this investigation. Moreover, thiram, a common widely used chemical pesticide, was used for comparison. RESULTS: The effects of all three above‐mentioned substances were investigated during an incubation experiment, for 15 weeks. Crushed neem pellets were added at 1.0, 2.0 or 3.0 g per 50 g of soil. Oregano dry matter was applied at 0.2, 0.4 or 0.6 g per 50 g of soil. Finally, thiram was applied at 0.1, 0.2 and 0.3 g per 50 g of soil. The addition of neem resulted in a decrease in organic carbon mineralisation, higher than that of oregano, but not as prominently as thiram. The addition of neem resulted in an increase in the content of nitrate, organic P, bioavailable P, bioavailable K and bioavailable Mn. Oregano had a slight negative effect on organic matter biodegradation, but caused an increase of nutritional mineral elements. Microbe colonies in soil were increased by the addition of neem cake granules, whereas oregano and thiram treatments caused a decrease. The addition of thiram reduced nitrate and available Mn contents, but at the lowest dose increased organic P and available K. Thiram reduced prominently available Cu at the upper rates, but it increased these forms at the lowest rate, while available Zn content was increased in two lowest rates. CONCLUSION: The results of this study indicated that neem or oregano could be applied to the soil without any extremely negative effect on the available forms of nutritional mineral elements, as thiram does. Copyright © 2009 Society of Chemical Industry 相似文献
95.
Al Otaiba Stephanie; Petscher Yaacov; Pappamihiel N. Eleni; Williams Rihana S.; Dyrlund Allison K.; Connor Carol 《Canadian Metallurgical Quarterly》2009,101(2):315
This study examines growth in oral reading fluency across 2nd and 3rd grade for Latino students grouped in 3 English proficiency levels: students receiving English as a second language (ESL) services (n = 2,182), students exited from ESL services (n = 965), and students never designated as needing services (n = 1,857). An important focus was to learn whether, within these 3 groups, proficiency levels and growth were reliably related to special education status. Using hierarchical linear modeling, the authors compared proficiency levels and growth in oral reading fluency in English between and within groups and then to state reading benchmarks. Findings indicate that oral reading fluency scores reliably distinguished between students with learning disabilities and typically developing students within each group (effect sizes ranging from 0.96 to 1.51). The growth trajectory included a significant quadratic trend (generally slowing over time). These findings support the effectiveness of using oral reading fluency in English to screen and monitor reading progress under Response to Intervention models, but also suggest caution in interpreting oral reading fluency data as part of the process in identifying students with learning disabilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
Dr. Eleni Loizou Dr. Popi Nicolaidou Kanari Georgia Kyriacou Maria Aletrari 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2010,5(3-4):459-463
Directive 98/83/EC concerning the drinking water quality and Directive 80/777/EC for Natural Mineral Water demand strict control and monitoring for the presence of metals. The State General Laboratory as the official control laboratory (Accredited by ISO 17025:2005) implements a national monitoring program in order to ensure that the drinking and natural mineral water quality satisfy the requirements of the respective Directives. The National Monitoring program covers mainly metals such as Pb, Cd, Cr, Ni, As, Se, Sb, Hg, Mn, Cu, Fe, Al and B in water supplied for human consumption either by distribution networks, vending machines, mobile water containers, ground water intended for human consumption as well as bottled water. The determination of metals in water by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) is a technique that successfully meets the requirements of the above Directives as it is a very powerful tool for the measurement of metals at very low concentrations with high accuracy and precision. The results obtained indicate that metal concentrations in drinking and bottled water examined were by far, below the acceptable legal limits and even below the relevant detection limits. However, in samples of bottled natural mineral water, high boron concentration were determined and risk assessment was performed due to the absence of relevant legal limits. The present paper demonstrates the steps undertaken by the General Water Analysis Laboratory of the SGL for the validated method used by ICP-MS in the determination of trace metals including boron in drinking and bottled water. 相似文献
97.
98.
Eleni Tomai Isabelle Herlin Jean‐Paul Berroir Poulicos Prastacos 《International journal of remote sensing》2013,34(13):3315-3330
In this paper, we introduce the idea of documenting operational chains for land degradation assessment using ontologies. We believe that this process will help end users better understand the application domain characteristics and evaluate the results of the assessment process. Since the application domain is wide, various operational chains for land degradation assessment and their associated documentation exist, according to different options. This parameterization process causes the development of different ontologies, which nonetheless are, to a certain extent, linked because of the common software components of the corresponding operational chains. We therefore propose a hierarchical structure of these ontologies; so that several requirements such as understanding of expert knowledge interconnections and of application domain variety, documentation and assimilation of new expert knowledge, and reusability of software components become feasible. 相似文献
99.
Condition monitoring, within the power industry, is essential to ensure continuous operation and health of electrical plans. This is a complex activity that requires the combination of different artificial intelligence techniques. This article describes a multiagent framework to support such a condition-monitoring approach. The resulting condition monitoring multiagent system (COMMAS) was applied to two different case studies, to monitor the start-up sequences of industrial gas turbines and identification of partial discharge signal defects in gas insulated substations. 相似文献
100.
Stefanos Gritzalis Sokratis K. Katsikas Dimitrios Lekkas Konstantinos Moulinos Eleni Polydorou 《Computers & Security》2000,19(8):731
In this paper, the unified, abstract KEYSTONE Public Key Infrastructure is presented. This architecture consists of a reference model, a functional architecture specification, and a set of technologies that can be used for implementing the functional units, along with all relevant standards. It was derived within the course of the KEYSTONE project, which was funded by the European Commission under the Electronic Trust Services II Programme. The proposed PKI architecture guarantees openness, scalability, flexibility, extensibility, integration with existing TTP and information infrastructure, transparency and, above all, security. Thus, it enjoys all the desirable characteristics and fulfils all those criteria that are essential for a PKI to constitute a successful framework for the development of inter-domain and international Trusted Services. 相似文献