全文获取类型
收费全文 | 144篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 22篇 |
金属工艺 | 19篇 |
机械仪表 | 14篇 |
建筑科学 | 4篇 |
能源动力 | 6篇 |
轻工业 | 22篇 |
石油天然气 | 2篇 |
无线电 | 3篇 |
一般工业技术 | 39篇 |
冶金工业 | 15篇 |
自动化技术 | 12篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 5篇 |
2013年 | 17篇 |
2012年 | 16篇 |
2011年 | 21篇 |
2010年 | 8篇 |
2009年 | 20篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1993年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有158条查询结果,搜索用时 15 毫秒
1.
Purification,structural data and biological properties of polysaccharide from Prunus amygdalus gum 下载免费PDF全文
Fatma Bouaziz Mohamed Koubaa Claire Boisset Helbert Fatma Kallel Dorra Driss Imen Kacem Raoudha Ghorbel Semia Ellouz Chaabouni 《International Journal of Food Science & Technology》2015,50(3):578-584
This work demonstrates the efficiency of almond gum polysaccharides (AGPs) as bioactive compounds. AGPs were first extracted using H2O2, in the presence of NaOH, at different times and temperatures. The optimal extraction conditions were 4% H2O2 and 2 N NaOH, for 7 h at 50 °C, leading to an extraction yield of 58.2% (w/w). After a purification step, the retained AGPs were characterised using high‐performance liquid chromatography showing a molecular weight of 99.3 kDa. The monosaccharide composition of AGPs were assessed using gas chromatography–mass spectrometry. AGPs were found to be a complex heteropolysaccharide with a repeating unit mainly composed of galactose, arabinose, xylose, mannose, rhamnose, and glucuronic acid with the respective ratios: 45:26:7:10:1:11. The acidic nature of the polysaccharide is due to the presence of glucuronic acid. Total antioxidant activity, free radical‐scavenging activity and reducing power assay of AGPs were investigated. The obtained results showed high antioxidant activities of AGPs. Furthermore, beyond 60 mg mL?1, AGPs exhibited bacterial growth inhibition for five pathogenic strains: Escherichia coli, Staphylococcus aureus, Enterococcus feacalis, Pseudomonas aeruginosa and Salmonella typhimurium. 相似文献
2.
Mechanical properties of alumina-fluorapatite composites with different titania additive amounts (0, 0.5, 1, 1.4, 2, 3, 4 and 5 wt%) have been investigated between 1200 and 1600℃. The optimum values of densification and mechanical properties of composites have been reached with 1.4 wt% of titania after the sintering process at 1500℃ for 1 h. Thus, the rupture strength of alumina-26.52 wt% Fap-1.4 wt% TiO2 reaches 75 MPa. At higher temperature and beyond 1.4 wt% TiO2 ,the densification and mechanical properties were hindered by the formation of both intergranular porosity and secondary phase. X-ray diffraction (XRD) analysis of alumina-Fap-TiO2 composites shows the formation of aluminium titanate (Al2O3-TiO2:Al2TiO5 ). The 27Al magic angle scanning nuclear magnetic resonance analysis of Al2O3-Fap-TiO2 composites reveals the presence of octahedral and pentahedral aluminium and novel environment relative to tetrahedral aluminium sites. 相似文献
3.
Ghayth Rigane Mohamed Bouaziz Nidhal Baccar Samira Abidi Sami Sayadi Ridha Ben Salem 《Journal of food science》2012,77(10):C1077-C1083
Abstract: A very simple method is proposed to produce hydroxytyrosol, a commercially unavailable compound with well‐known biological properties which justify a potential commercial application. The 2‐phase Chemlali olive pomace is selected as substrate for chemical treatment. Different conditions of chemical treatment, including concentration of acid and alkaline solutions, time and temperature, were assayed. A high amount of hydroxytyrosol (1360 mg/kg of fresh 2‐phase olive pomace) was obtained using water bath after treatment at 80 °C for 90 min with 1 M of H3PO4. However, treatment of 2‐phase Chemlali olive pomace using autoclave apparatus could produce a large amount of hydroxytyrosol (1993.60 and 1515.88 mg/kg of fresh alperujo, 1 M acid and basic catalyst, respectively). By taking into consideration practical and economic aspects, acid‐catalyzed treatment was more effective using autoclave conditions, whereas the alkali catalyzed conditions were not very suitable. This study could provide useful information for industry to produce the potentially bioactive compound. Practical Application: The 2‐phase Chemlali olive pomace is selected as substrate for chemical treatment. Treatment of “alperujo” using water bath or autoclave apparatus was carried out. A high amount of hydroxytyrosol was obtained using autoclave apparatus. 相似文献
4.
5.
A 2D finite element analysis of the effect of numerical parameters on the reliability of Ti6Al4V machining modeling 总被引:1,自引:0,他引:1
Mariem Yaich Yessine Ayed Zoubeir Bouaziz Guénaël Germain 《Machining Science and Technology》2020,24(4):509-543
AbstractThe numerical analysis, based on the finite element modeling (FEM), presents nowadays an efficient computational tool. It allows a better understanding of several thermo-mechanical phenomena involved during the machining process. However, its reliability heavily depends on the accurate definition of the numerical model. In this regard, a FE analysis focused on the 2D modeling of the Ti6Al4V dry orthogonal machining was carried out in this study. The relevance of different numerical meshing approaches and finite elements topologies was studied. The effect of the friction coefficient on the numerical chip morphology, its geometry, the cutting and the feed forces was investigated. The adequacy of several compared adaptive meshing approaches, in terms of the modeling of severe contact conditions taking place around the cutting-edge radius, was underlined in the current study. However, numerical serrated chips, closer to the experimental ones, were only predicted when the pure Lagrangian formulation was adopted and a proper determination of the failure energy was carried out. The definition of different mesh topologies highlighted the efficiency of the 4-node quadrangular mesh, with a suitable edge length, in increasing the agreement with the experimental data, while reducing the computing times. 相似文献
6.
Fatma Bouaziz Mohamed Koubaa Khaoula Ben Jeddou Francisco J. Barba Fatma Chaari Souhail Besbes Rhoudha Ellouz Ghorbel Semia Ellouz Chaabouni 《International Journal of Food Science & Technology》2017,52(1):205-213
The aim of this work was to investigate the effect of almond gum as dietary fibre source in enhancing the wheat bread quality. Different amounts of almond gum (2%, 5% and 10% (w/w)) were used in bread formulation. The volume, texture, crust and crumb colour, as well as the sensorial properties, were evaluated and compared to control (without almond gum). The obtained results showed that almond gum addition enhanced significantly the volume of bread. The highest volume was obtained using 2% almond gum concentration with 23.6% increase, compared to control. Using almond gum in bread formulation improved considerably its texture with a notable decrease in hardness by 61.7% and 42.5% when using 2% and 5% almond gum, respectively. The sensory analysis scores showed that the better overall acceptability was found for breads supplemented with 2% almond gum, as compared to control and breads supplemented with 5% or 10% almond gum. 相似文献
7.
D. Rèche T. SturelO. Bouaziz A. ColA.F. Gourgues-Lorenzon 《Materials Science and Engineering: A》2011,528(15):5241-5250
In order to optimize the metallurgical quality of advanced high strength steels for automotive applications, the present study aims at understanding damage mechanisms involved in air-bending of two low alloy TRansformation Induced Plasticity (TRIP)-aided steels. Air-bending tests were performed together with metallographic investigations of damage development in bent specimens. In order to assess the role of hard bands induced by chemical segregations, air-bending tests on specimens with various locations of the main hard band (with respect to the neutral fibre) were performed. Cracking initiates from the outer surface or from just below, mainly by decohesion between ferrite and secondary (martensite) phases, at hard bands located close to the outer surface. From these examinations, together with a simple kinematics analysis of bending, a quantitative relationship between cracking, local thickness of hard band and local “mesoscopic” strain is proposed. 相似文献
8.
Moez Smaoui Zoubeir Bouaziz Ali Zghal Gilles Dessein Maher Baili 《The International Journal of Advanced Manufacturing Technology》2011,56(5-8):463-474
Since industry is rapidly developing, either locally or globally, manufacturers witness harder challenges due to the growing competitivity. This urges them to better consider the four factors linked to production and output: quality, quantity, cost and price, quality being of course the most important factor which constitutes their main concern. Efforts will be concentrated??in this research??on improving the quality and securing more accuracy for a machined surface in ball-end milling. Quality and precision are two essential criteria in industrial milling. However, milling errors and imperfections, due mainly to the cutting tool deflection, hinder the full achieving of these targets. Our task, all along this paper, consists in studying and realizing the simulation of the deflected cutting tool trajectory, by using the methods which are available. In a future stage, and in the frame of a deeper research, the simulation process will help to carry out the correction and the compensation of the errors resulting from the tool deflection. The corrected trajectory which is obtained by the method mirror will be sent to the machine. To achieve this goal, the next process consists??as a first step??in selecting a model of cutting forces for a ball-end mill. This allows to define??later on??the behavior of this tool, and the emergence of three methods namely the analytical model, the finite elements method, and the experimental method. It is possible to tackle the cutting forces simulation, all along the tool trajectory, while this latter is carrying out the sweeping of the part to be machined in milling and taking into consideration the cutting conditions, as well as the geography of the workpiece. A simulation of the deflected cutting tool trajectory dependent on the cutting forces has been realized. 相似文献
9.
Cold uniaxial pressing of powder into a green body is a common forming process used in ceramic and pharmaceutical industries.
Argillaceous particles are used as a model system to investigate granule failure during compaction. Indeed, the volume enclosed
between the die and punches is reduced and the powder consolidates until a final height is obtained or a prescribed compacting
pressure is reached. Desired properties of the green body are high strength, uniform density, no defects and fracture. In
this work an experimental investigation has been focused on the ‘cracking cone’ fracture in powder compacts. This includes
studies of crack propagation and determination of operating conditions to avoid the green body fracture. The numerical modelling
is implemented using a finite element method based on the Von Mises criterion. A case of simulation is presented to demonstrate
the ability of the model to compute the distribution of the relative stresses. 相似文献
10.
Effective strain rate sensitivity of two phase materials 总被引:1,自引:0,他引:1
Analytical expressions are derived for the effective strain rate sensitivity exponent of a two phase material when the behavior of both phases and of the composite itself can be described by power law relations between the stress and strain rates. The material is assumed to be plastically isotropic and obey to von-Mises type creep behavior. Two types of boundary conditions are considered: strain or stress-controlled. The obtained formulas are applied to a geological composite material (mixture of camphor and octachloropropane) with the help of different simple models of two phase composites. 相似文献