全文获取类型
收费全文 | 180篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 45篇 |
金属工艺 | 2篇 |
机械仪表 | 6篇 |
建筑科学 | 10篇 |
能源动力 | 15篇 |
轻工业 | 23篇 |
水利工程 | 5篇 |
石油天然气 | 1篇 |
无线电 | 15篇 |
一般工业技术 | 32篇 |
冶金工业 | 10篇 |
原子能技术 | 2篇 |
自动化技术 | 29篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 17篇 |
2021年 | 14篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 17篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 21篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 3篇 |
1999年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 2篇 |
1985年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有195条查询结果,搜索用时 0 毫秒
91.
The effects of impeller speed, air flow rate, cell concentration, agitator size and cell volume on the recovery of aluminium particles have been studied in a KHD Humboldt Wedge AG machine, using alkyl benzene sodium sulphonate paste as collector and pine oil as frother. The recovery yield increased with increasing impeller speed, air flow rate, cell concentration and cell volume, up to a certain range, whereafter it decreased. A decrease in the recovery yield was observed on increasing the agitator size. A mathematical model has been developed to correlate percentage recovery with the above variables. 相似文献
92.
This paper investigates combined heat transfer improvement methods. These methods include introducing pulsating flow, adding nanofluids, and manipulating the flow's characteristics in a corrugated plate heat exchanger. Tests are carried out with multi-walled carbon nanotube (MWCNT), graphene nanoplate (GNP), and a mixture of GNP and MWCNT meeting the requirement of 0.01% nanofluids volume fraction and exposed to pulsation. Results demonstrated that the use of pulsating frequencies from 0 to 30 Hz of GNP-water, MIX nanofluids–water, and MWCNT–water nanofluids with a constant concentration of 0.01 wt% leads to a significant improvement in heat transfer. Using pure water at frequency f = 0 Hz as a benchmark, the Nusselt number of the mixture nanofluid increases by 15.2%, 27.5%, 40.4%, and 52.8% with the increase of frequency pulsation from 0 to 30 Hz with a slight effect on the pressure-drop at this low used constant nanofluid concentration = 0.01%. The highest Nusselt number value for GNP-water nanofluid improved by an amount of 58.3% at the highest frequency compared with pure water at f = 0 Hz. 相似文献
93.
Pattern Analysis and Applications - Because of their high recognition rates, coding-based approaches that use multispectral palmprint images have become one of the most popular palmprint... 相似文献
94.
Ghoumid Kamal Ghadban Amina Boukricha Sokaina Ar-reyouchi El Miloud Yahiaoui Reda Mekaoui Slimane Raschetti Marina Lepers Catherine 《Telecommunication Systems》2020,73(3):433-441
Telecommunication Systems - Optical code division multiple access (OCDMA) systems are attracting an increasing interest in optical fiber communication. This is due to the various advantages that... 相似文献
95.
Exploring bioaugmentation strategies for azo dye CI Reactive Violet 5 decolourization using bacterial mixture: dye response surface methodology 下载免费PDF全文
Lamia Ayed Karima Bekir Sami Achour Abdelkrim Cheref Amina Bakhrouf 《Water and Environment Journal》2017,31(1):80-89
The use of response surface methodology based on statistical design of experiments is becoming increasingly widespread in several sciences such as analytical and environmental chemistry. In the present study, the decolourization and the degradation efficiency of CI Reactive Violet 5 (CIRV5) was studied using a novel bacterial consortium. CIRV5 (1000 p.p.m.) biodegradation was investigated under shaking condition in mineral salt medium solution (MSM) at a 7.5 pH and a 25°C temperature. The degradation pathways were also predicted, using UV‐visible spectroscopy analysis. Under optimal conditions, the bacterial consortium was able to decolourize the dye completely (>99%) within 8 h. The colour and chemical oxygen demand (COD) removal were 99.29 and 94.93%, respectively. Polymerase chain reaction (PCR) technique was utilized to detect the adhesin genes ‘icaA’ and ‘icaD.’ Our results showed that Staphylococcus aureus had a high decolourization capacity. Phytotoxicity study using Triticum turgidum ssp durum showed the no toxicity of the produced products. 相似文献
96.
Recent developments in mass spectrometry have permitted direct analysis of biomolecules in tissue. However, most studies have focused on proteins with emphasis on biomarker discovery. In the present work, matrix-assisted laser desorption/ionization mass spectrometry was used for the direct analysis of lipids in rat cerebellum. The lipid bilayer role as a storage depot for small organic molecules such as therapeutic drugs and pollutants such as DDT, as well as the ability to compare lipid profiles in healthy and diseased animal models, are a few of the many reasons why the direct probing of tissue to determine the qualitative and possibly quantitative lipid content could be a very useful tool. Molecular ions corresponding to cholesterol, phosphatidylcholines, sphingomyelins, and phosphatidylethanolamines were recorded in positive ion mode, while ones corresponding to phosphatidylinositols, sulfatides, and gangliosides were recorded in negative ion mode. Overall, representatives from all major categories of brain lipids including cholesterol, 15 phospholipid species (9 phosphatidylcholines, 1 sphingomyelin, 3 phosphatidylethanolamines, 2 phosphatidylinositols), 10 sulfatides (5 hydroxylated species and 5 nonhydroxylated species), and 7 species of gangliosides were detected. 相似文献
97.
Palani Parthiban Fasquelle Didier Tachafine Amina 《Journal of Materials Science》2022,57(26):12279-12317
Journal of Materials Science - In pursuit of developing high-performance lead-free energy storage capacitors, strontium titanate (SrTiO3) and calcium titanate (CaTiO3) are widely recognised as... 相似文献
98.
Amina Kemmar Yahia Lebbah Samir Loudni Patrice Boizumault Thierry Charnois 《Constraints》2017,22(2):265-306
Sequential pattern mining (SPM) is an important data mining problem with broad applications. SPM is a hard problem due to the huge number of intermediate subsequences to be considered. State of the art approaches for SPM (e.g., PrefixSpan Pei et al. 2001) are largely based on the pattern-growth approach, where for each frequent prefix subsequence, only its related suffix subsequences need to be considered, and the database is recursively projected into smaller ones. Many authors have promoted the use of constraints to focus on the most promising patterns according to the interests of the end user. The top-k SPM problem is also used to cope with the difficulty of thresholding and to control the number of solutions. State of the art methods developed for SPM and top-k SPM, though efficient, are locked into a rather rigid search strategy, and suffer from the lack of declarativity and flexibility. Indeed, adding new constraints usually amounts to changing the data-structures used in the core of the algorithm, and combining these new constraints often require new developments. Recent works (e.g. Kemmar et al. 2014; Négrevergne and Guns 2015) have investigated the use of Constraint Programming (CP) for SPM. However, despite their nice declarative aspects, all these modelings have scaling problems, due to the huge size of their constraint networks. To address this issue, we propose the Prefix-Projection global constraint, which encapsulates both the subsequence relation as well as the frequency constraint. Its filtering algorithm relies on the principle of projected databases which allows to keep in the variables domain, only values leading to a frequent pattern in the database. Prefix-Projection filtering algorithm enforces domain consistency on the variable succeeding the current frequent prefix in polynomial time. This global constraint also allows for a straightforward implementation of additional constraints such as size, item membership, regular expressions and any combination of them. Experimental results show that our approach clearly outperforms existing CP approaches and competes well with the state-of-the-art methods on large datasets for mining frequent sequential patterns, sequential patterns under various constraints, and top-k sequential patterns. Unlike existing CP methods, our approach achieves a better scalability. 相似文献
99.
Amina Rangoonwala Nicholas M. Enwright Elijah Ramsey III Joseph P. Spruce 《International journal of remote sensing》2016,37(7):1692-1713
This study combined a radar-based time series of Hurricane Sandy surge and estimated persistence with optical sensor-based marsh condition change to assess potential causal linkages of surge persistence and marsh condition change along the New Jersey Atlantic Ocean coast. Results based on processed TerraSAR-X and COSMO-SkyMed synthetic aperture radar (SAR) images indicated that surge flooding persisted for 12 h past landfall in marshes from Great Bay to Great Egg Harbor Bay and up to 59 h after landfall in many back-barrier lagoon marshes. Marsh condition change (i.e. loss of green marsh vegetation) was assessed from optical satellite images (Satellite Pour l’Observation de la Terre and Moderate Resolution Imaging Spectroradiometer) collected before and after Hurricane Sandy. High change in condition often showed spatial correspondence, with high surge persistence in marsh surrounding the lagoon portion of Great Bay, while in contrast, low change and high persistence spatial correspondence dominated the interior marshes of the Great Bay and Great Egg Harbor Bay estuaries. Salinity measurements suggest that these areas were influenced by freshwater discharges after landfall possibly mitigating damage. Back-barrier marshes outside these regions exhibited mixed correspondences. In some cases, topographic features supporting longer surge persistence suggested that non-correspondence between radar and optical data-based results may be due to differential resilience; however, in many cases, reference information was lacking to determine a reason for non-correspondence. 相似文献
100.