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排序方式: 共有548条查询结果,搜索用时 15 毫秒
101.
Effect of Intercritical Annealing Parameters on Dual Phase Behavior of Commercial Low-Alloyed Steels 总被引:4,自引:1,他引:3
It is known that dual phase (DP) heat treatments and alloying elements have a strong effect on martensitic transformations and mechanical properties. In the present work, the effects of some intercritical annealing parameters (heating rate, soaking temperature, soaking time, and quench media) on the microstructure and mechanical properties of cold rolled DP steel were studied. The microstructure of specimens quenched after each annealing stage, was analyzed using optical microscopy. The tensile properties, determined for specimens submitted to complete annealing cycles, are influenced by the volume fractions of multi phases (originated from martensite, bainite and retained austenite), which depend on annealing processing parameters. The results obtained showed that the yield strength (YS) and the ultimate tensile strength (UTS) increase with the increasing intercritical temperature and cooling rate. This can be explained by higher martensite volume ratio with the increased volume fraction of austenite formed at the higher temperatures and cooling rates. The experimental data also showed that, for the annealing cycles carried out, higher UTS values than ~ 800 MPa could be obtained with the S3 steel grade. 相似文献
102.
E. Tel A. A. Gok M. Sahan İ. H. Sarpun Y. Kavun A. Aydin 《Journal of Fusion Energy》2017,36(4-5):173-177
In this study, calculation of charged particles induced nuclear reactions of beryllium (9Be) target nuclei have been investigated in the incident proton and alpha at energy range from threshold to 50 MeV. The excitation functions for 9Be target nuclei reactions have been calculated by using PCROSS nuclear reaction calculation code. Weisskopf–Ewing model for equilibrium, calculations and the full exciton and cascade exciton models for pre-equilibrium calculations were used. Also, the semi-empirical calculations for (p,α) reactions have been done by using cross section formula updated with new coefficient developed by Tel et al. (Pramana Indian Acad Sci 74(6):931, 2010). The calculated results were compared with the experimental data for different energy levels ranging from 0.00 to 9.65 MeV taken from the literature. 相似文献
103.
Nuh Aydin Suat Karadeniz Bahattin Yildiz 《Applicable Algebra in Engineering, Communication and Computing》2013,24(5):355-367
We consider quasi-cyclic codes over the ring $\mathbb{F }_2+u\mathbb{F }_2+v\mathbb{F }_2+uv\mathbb{F }_2$ , a finite non-chain ring that has been recently studied in coding theory. The Gray images of these codes are shown to be binary quasi-cyclic codes. Using this method we have obtained seventeen new binary quasi-cyclic codes that are new additions to the database of binary quasi-cyclic codes. Moreover, we also obtain a number of binary quasi-cyclic codes with the same parameters as best known binary linear codes that otherwise have more complicated constructions. 相似文献
104.
105.
Process management and innovation arguably remain among the concepts under focus of recent researches since there is no significantly outstanding method to measure and monitor the level of innovation in the manufacturing processes over a particular time period taking the fundamental activities of manufacturing processes into account. Although there are various studies relevant to process improvement, manufacturing processes are not focused on in the literature. This paper presents a novel performance indicator, called degree of process innovation, for monitoring and measuring innovation in manufacturing processes based on the four most important components among the fundamental activities of a manufacturing system. The components are namely Average Labour Utilisation, Cumulative Bottleneck Ratio, Unit Production Time and Unit Production Cost. The idea behind this approach has flourished on the basis of an indicator proposed in the literature to measure the general organisational improvements. The scope of that indicator has been narrowed down to manufacturing processes to accurately reflect the state of the manufacturing processes. The proposed approach has been verified with a case study in manufacturing industry, where each of the four sub-indicators was calculated based on the data provided and aggregated into the degree of process innovation. The innovation degree is successfully indicated. 相似文献
106.
A CNC machining operation is the outcome of the application of the integrated capabilities of various resources within the CNC machining centre. Part fixtures, clamping and other location mechanisms are essential subsets of CNC machining resources. Today, various fixturing techniques and attachments available in the market allow manufacturers to enhance their production capability without buying expensive machine tools. This technology-rich fixturing domain is detached while representing and exchanging machine tool resource information for making manufacturing decisions. The research work in this article utilises the STEP-NC compliant unified manufacturing resource model (UMRM) for representing fixtures in conjunction with the parent CNC machining centre. Thus, UMRM is enhanced in this context to represent various fixtures such as universal vises, chucks, pallets and auxiliary rotary tables among others. The major contribution of this article is the application of the extension of the UMRM approach for representing fixturing domain, which allows generic modelling of fixtures and loading devices in addition to machine workpiece and process modelling. This would enable the stage of automated process planning and manufacturing. The universal approach in representing resource information allows the data to be utilised for making a wide variety of manufacturing decisions. 相似文献
107.
Ozturk E Ocak N Turan A Erener G Altop A Cankaya S 《Journal of the science of food and agriculture》2012,92(1):59-65
BACKGROUND: The effects of humic substances (HS) on quality traits (colour, water‐holding capacity, and pH) of breast and thigh meats and on blood minerals (calcium and phosphorus) and on metabolites (glucose, total protein, triglyceride and cholesterols) as well as on the performance, carcass, and gastrointestinal tract (gut) traits of broilers were studied. In total, 480 male chicks (ROSS 308) were allocated to four treatments, each with five replicates containing 24 birds. While control birds were fed a diet (mash form) with no additives (0 HS), other treatment birds were fed with diets containing HS at 0.5 (0.5 HS), 1.0 (1 HS) or 1.5 (1.5 HS) g kg?1 from 1 to 42 days of age. RESULTS: The body and carcass weights and feed efficiency increased (P < 0.05) by 1.5 HS, and blood cholesterol decreased (P < 0.05) by 1 HS and 1.5 HS compared to 0 HS. The 0.5 HS decreased (P < 0.10) low‐density lipoprotein compared to 0 HS. The 0.5 HS resulted in thigh meat and breast meat that were lighter and darker than those found in the other groups and 1.5 HS respectively (P < 0.01). CONCLUSION: Feeding with a diet containing HS caused a measurable variation in the meat quality and blood cholesterol as well as the performance, carcass, and gut traits of broilers. Copyright © 2011 Society of Chemical Industry 相似文献
108.
Aydin Yildiz Sait Erdogan Abdurrahman Saydut Candan Hamamci 《Food Analytical Methods》2012,5(3):591-595
Among food sources, particular attention is paid to milk and dairy products, due to its nutritional importance. Benzoic acid
is extensively used in the preservation of foods. A reliable method for the determination of benzoic acid in some dairy products,
such as yogurt, ayran, and cheese using high-performance liquid chromatography and UV detection was validated. The peak of
benzoic acid was measured at a wavelenght of 226 nm. Samples were purchased from supermarkets in Turkey in the period 2009–2010.
All dairy product samples were produced from cow’s milk. The levels of benzoic acid in cheese, yogurt, and ayran samples were
in the range of 3.17 to 56.77 mg kg−1, 8.94 to 28.30 mg kg−1, and 1.54 to 16.57 mg L−1, respectively. The results show that benzoic acid widely occurs in milk products in Turkey at the low levels. 相似文献
109.
Bahcebasi S Kocyigit I Akyol L Unal A Sipahioğlu MH Oymak O Utas C 《Hemodialysis international. International Symposium on Home Hemodialysis》2011,15(2):284-287
Central venous catheterization is frequently performed for perioperative management and long-term intravenous access. Although complications associated with central venous catheter insertion have been widely reported, there are few reports of carotid-jugular arteriovenous fistula formation. Endovascular procedures are associated with a risk of immediate and delayed thromboembolic and ischemic complications. We describe a case of a carotid-jugular arteriovenous fistula and a cerebrovascular infarct following the insertion of a double-lumen catheter for hemodialysis access. We provide recommendations for the prevention and the early detection of this iatrogenic complication. 相似文献
110.
Environmental concerns associated with fossil fuels are creating increased interest in alternative non-fossil energy sources.
Nuclear fusion can be one of the most attractive sources of energy from the viewpoint of safety and minimal environmental
impact. When considered in all energy systems, the requirements for performance of structural materials in a fusion reactor
first wall, blanket or diverter, are arguably more demanding or difficult than for other energy system. The development of
fusion materials for the safety of fusion power systems and understanding nuclear properties is important. In this paper,
ground state properties for some structural fusion materials as 27Al, 51V, 52Cr, 55Mn, and 56Fe are investigated using Skyrme–Hartree–Fock method. The obtained results have been discussed and compared with the available
experimental data. 相似文献