全文获取类型
收费全文 | 347篇 |
免费 | 26篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 98篇 |
金属工艺 | 9篇 |
机械仪表 | 32篇 |
建筑科学 | 8篇 |
矿业工程 | 2篇 |
能源动力 | 8篇 |
轻工业 | 60篇 |
水利工程 | 7篇 |
石油天然气 | 4篇 |
无线电 | 24篇 |
一般工业技术 | 43篇 |
冶金工业 | 18篇 |
自动化技术 | 59篇 |
出版年
2024年 | 3篇 |
2023年 | 4篇 |
2022年 | 23篇 |
2021年 | 38篇 |
2020年 | 22篇 |
2019年 | 18篇 |
2018年 | 19篇 |
2017年 | 12篇 |
2016年 | 18篇 |
2015年 | 11篇 |
2014年 | 20篇 |
2013年 | 34篇 |
2012年 | 22篇 |
2011年 | 28篇 |
2010年 | 16篇 |
2009年 | 19篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 12篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
排序方式: 共有373条查询结果,搜索用时 15 毫秒
361.
362.
F. H. S. Eleuterio L. S. Amorim H. Belich M. T. D. Orlando C. A. C. Passos J. S. Espinoza Ortiz 《Journal of Superconductivity and Novel Magnetism》2014,27(12):2679-2684
We investigate Hg 0.82Re 0.18Ba 2Ca 2Cu 3O 8.76 polycrystalline samples with an optimum oxygen content aimed to analyze both their granular composition and to measure their magnetic response. We find out that the sample corresponds to a solid solution of two intrinsic structural superconductor phases. The AC magnetic susceptibility of a powder sample with a particle size of 20 μm have a critical temperature at 133 K. To make mesoscopic-scale particles of 600 nm in size, a sample of the powder was crushed and sieved. Now, the AC magnetic sample susceptibility shows two critical temperatures at 133 and 98 K. They have been described adopting a particular parametrization of the complex scalar field associated with the order parameter in a new framework of the Ginzburg–Landau theory. Thus, we propose a microscopic model to describe the dynamical interaction between these two types of grains. 相似文献
363.
Kurtis F. Budden Shaan L. Gellatly Annalicia Vaughan Nadia Amorim Jay C. Horvat Nicole G. Hansbro David L. A. Wood Philip Hugenholtz Paul G. Dennis Peter A. B. Wark Philip M. Hansbro 《International journal of molecular sciences》2023,24(1)
Bifidobacterium are prominent gut commensals that produce the short-chain fatty acid (SCFA) acetate, and they are often used as probiotics. Connections between the gut and the lung, termed the gut–lung axis, are regulated by the microbiome. The gut–lung axis is increasingly implicated in cigarette smoke-induced diseases, and cigarette smoke exposure has been associated with depletion of Bifidobacterium species. In this study, we assessed the impact of acetate-producing Bifidobacterium longum subsp. longum (WT) and a mutant strain with an impaired acetate production capacity (MUT) on cigarette smoke-induced inflammation. The mice were treated with WT or MUT B. longum subsp. longum and exposed to cigarette smoke for 8 weeks before assessments of lung inflammation, lung tissue gene expression and cecal SCFAs were performed. Both strains of B. longum subsp. longum reduced lung inflammation, inflammatory cytokine expression and adhesion factor expression and alleviated cigarette smoke-induced depletion in caecum butyrate. Thus, the probiotic administration of B. longum subsp. longum, irrespective of its acetate-producing capacity, alleviated cigarette smoke-induced inflammation and the depletion of cecal butyrate levels. 相似文献
364.
Fernando Guedes Mariana V. Branquinho Sara Biscaia Rui D. Alvites Ana C. Sousa Bruna Lopes Patrícia Sousa Alexandra Rêma Irina Amorim Ftima Faria Tatiana M. Patrício Nuno Alves Antnio Bugalho Ana C. Maurício 《International journal of molecular sciences》2022,23(24)
Additive manufacturing or 3D printing applying polycaprolactone (PCL)-based medical devices represents an important branch of tissue engineering, where the sterilization method is a key process for further safe application in vitro and in vivo. In this study, the authors intend to access the most suitable gamma radiation conditions to sterilize PCL-based scaffolds in a preliminary biocompatibility assessment, envisioning future studies for airway obstruction conditions. Three radiation levels were considered, 25 kGy, 35 kGy and 45 kGy, and evaluated as regards their cyto- and biocompatibility. All three groups presented biocompatible properties, indicating an adequate sterility condition. As for the cytocompatibility analysis, devices sterilized with 35 kGy and 45 kGy showed better results, with the 45 kGy showing overall improved outcomes. This study allowed the selection of the most suitable sterilization condition for PCL-based scaffolds, aiming at immediate future assays, by applying 3D-customized printing techniques to specific airway obstruction lesions of the trachea. 相似文献
365.
A new SiO2/SnO2 carbon ceramic composite was prepared by the sol-gel method, and its potential application in electrochemistry as a novel electrode material has been studied. The prepared xerogel was structurally and electrochemically characterized by scanning electron microscopy coupled to energy dispersive spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and cyclic voltammetry. The composite was pressed in a rigid disk-shape and used as a conductive substrate to immobilize a water-soluble organic-inorganic hybrid polymer, 3-n-propyl-4-picolinium chloride silsesquioxane. The oxidation of nitrite was studied on this polymer film coated electrode in aqueous solution using cyclic voltammetry and differential pulse voltammetry. This modified electrode exhibited a better defined voltammetric peak shifted negatively about 60 mV. The linear detection limit found for nitrite was from 1.3 × 10−5 to 1.3 × 10−3 mol l−1 and the detection limit was 3.3 × 10−6 mol l−1. 相似文献
366.
Louryval Coelho Paixão Ilmar Alves Lopes Allan Kardec Duailibe Barros Filho Audirene Amorim Santana 《应用聚合物科学杂志》2019,136(48):48263
Biofilms are defined as flexible films prepared from biological materials such as proteins or polysaccharides, which act as barriers to external elements and can consequently protect the products and increase their shelf life. The objective of this study was to evaluate the effects of hydrophilic and hydrophobic plasticizers and mixtures thereof in the characterization of alginate biofilms. Films plasticized with glycerol were less hygroscopic than films plasticized with TC (tributyl citrate) or with TC/glycerol mixtures. The presence of TC in the plasticization of the films turn them more hygroscopic, thus confirming their excellent performance in protecting against dissolution and in water vapor permeability. Films plasticized with pure TC were the least water-soluble and showed the higher tensile stress, having a globular microstructure, which was attenuated as the TC was partially substituted by glycerol, making the structure more compact but not as homogenous as films containing only glycerol as the plasticizer. Films plasticized with pure TC and with TC/glycerol mixtures were opaque and showed only one glass transition temperature (Tg). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48263. 相似文献
367.
Bio‐nanocomposites for food packaging applications: effect of cellulose nanofibers on morphological,mechanical, optical and barrier properties
下载免费PDF全文
![点击此处可从《Polymer International》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Raissa Alvarenga Carvalho Taline Amorim Santos Viviane Machado de Azevedo Pedro Henrique Campelo Felix Marali Vilela Dias Soraia Vilela Borges 《Polymer International》2018,67(4):386-392
The effect of the addition of various concentrations of cellulose nanofibers (CNF) on the thickness, solubility, morphology, mechanics, water vapor permeability and optical properties of biopolymers isolated from whey protein produced by the casting method was studied. The results show that the addition of CNF did not cause significant variation in the thickness of the films and resulted in nanocomposites with lower solubility and water vapor permeability. Scanning electron microscopy analysis showed that the films obtained with up to 4% of CNF showed good dispersion of the nanofibers in the whey protein matrix. The results of mechanical tests showed that the nanofibers acted as reinforcing material resulting in more resistant and less flexible films. © 2017 Society of Chemical Industry 相似文献
368.
Biological treatment of effluent containing textile dyes 总被引:1,自引:0,他引:1
I M C Gonçalves A Gomes R Brás M I A Ferra M T P Amorim R S Porter 《Coloration Technology》2000,116(12):393-397
Colour removal of textile dyes from effluent was evaluated using a laboratory 'upflow anaerobic sludge blanket' reactor. Several commercial dyes were selected to study the effect of dye structure on colour removal. The anaerobic reactor was fed with glucose, an easily biodegradable organic matter and selected individual dyes. Results show that some of the dyes are readily reduced under anaerobic conditions even at a high concentration of 700 mg/l. The average removal efficiency for acid dyes using this method was between 80 and 90% and that observed for the direct dye used was 81%. Laboratory experiments using the anaerobic reactor with disperse dyes, such as an anthraquinonebased dye, were unsuccessful even at low concentrations of 35 mg/l. Additional experiments were conducted to evaluate the toxicity of a selected disperse dye to an anaerobic environment. Results indicate that the purified dye is more toxic to the biomass than the commercial one. 相似文献
369.
Milton Carlos Kuga Gisele Faria Marcos Antonio Rossi Jardel Camilo do Carmo Monteiro Idomeo Bonetti‐Filho Fábio Luiz Camargo Vilella Berbert Kátia Cristina Keine Marcus Vinicius Reis Só 《Scanning》2013,35(1):17-21
The presence of residual endodontic sealer in the pulp chamber may cause discoloration of the dental crown and interfere with the adhesion of restorative materials. The aim of this study was to compare the efficacy of different solvents in removing residues of an epoxy resin‐based sealer (AH Plus) from the dentin walls of the pulp chamber, by scanning electron microscopy (SEM). Forty‐four bovine incisor dental crown fragments were treated with 17% EDTA and 2.5% NaOCl. Specimens received a coating of AH Plus and were left undisturbed for 5 min. Then, specimens were divided in four groups (n = 10) and cleaned with one of the following solutions: isopropyl alcohol, 95% ethanol, acetone solution, or amyl acetate solution. Negative controls (n = 2) did not receive AH Plus, while in positive controls (n = 2) the sealer was not removed. AH Plus removal was evaluated by SEM, and a score system was applied. Data were analyzed by Kruskal–Wallis and Dunn tests. None of the solutions tested was able to completely remove AH Plus from the dentin of the pulp chamber. Amyl acetate performed better than 95% ethanol and isopropyl alcohol (p < 0.05), but not better than acetone (p > 0.05) in removing the sealer from dentin. No significant differences were observed between acetone, 95% ethanol, and isopropyl alcohol (p > 0.05). It was concluded that amyl acetate and acetone may be good options for cleaning the pulp chamber after obturation with AH Plus. SCANNING 35:17‐21, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
370.
Jingwei Tang Byungsoo Kim Vinicius C. Azevedo Barbara Solenthaler 《Computer Graphics Forum》2023,42(2):161-173
Controlling fluid simulations is notoriously difficult due to its high computational cost and the fact that user control inputs can cause unphysical motion. We present an interactive method for deformation-based fluid control. Our method aims at balancing the direct deformations of fluid fields and the preservation of physical characteristics. We train convolutional neural networks with physics-inspired loss functions together with a differentiable fluid simulator, and provide an efficient workflow for flow manipulations at test time. We demonstrate diverse test cases to analyze our carefully designed objectives and show that they lead to physical and eventually visually appealing modifications on edited fluid data. 相似文献