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排序方式: 共有676条查询结果,搜索用时 31 毫秒
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Siddhartha Sankar Mandal K. S. Ghosh 《International Journal of Cast Metals Research》2018,31(3):177-192
Destabilisation of as-cast chromium white iron with 16 wt-% chromium are performed by continuous destabilisation treatment for 4 h and short duration (0.66 h) cyclic destabilisation treatment at 900, 950, 1000, 1050, and 1100 °C. Continuous destabilisation causes secondary carbides precipitation from austenite which on slow cooling transforms to pearlite matrix. Cyclic destabilisation treatment causes similar precipitation of finer secondary carbides following shorter period austenitisation and a matrix containing martensite and retained austenite on forced-air cooling. After continuous destabilisation, hardness falls below the as-cast value (HV622); whereas it rises to HV950 after cyclic destabilisation treatment. The as-cast notched impact toughness (4.0 J) increases to 8.5 J or more after both continuous and cyclic destabilisation at 1050 and 1100 °C. Abrasive wear resistance after continuous destabilisation improves only at higher wear load (49.0 N), while after cyclic destabilisation it supersedes the as-cast and Ni-Hard IV performance at both low (19.6 N) and high (49.9 N) wear load. 相似文献
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Shrestha Bibek Alsadoon Abeer Prasad P. W. C. Al-Naymat Ghazi Al-Dala’in Thair Rashid Tarik A. Alsadoon Omar Hisham 《Multimedia Tools and Applications》2022,81(27):38945-38969
Multimedia Tools and Applications - The natural population-based prediction of type 2 diabetes is costly since it needs a high number of resources. Even though much research has used machine... 相似文献
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ABSTRACTMany governments have begun to demand that large public facility agencies adopt and implement building information modelling (BIM) in their business processes. Some have published BIM guides. Most of these are technical specifications that are useful at the project level, but they provide no support for the organization-level adoption effort. On the basis of a literature review, action research and case studies of five large UK government facility agencies, a BIM adoption impact map (BIM AIM) is proposed. It describes a set of possible relationships between the actions taken by public facility agencies, the intermediate outcomes of their actions and the eventual achievement of value for the occupants of the facilities they build. BIM AIM can be used by public facility agencies with a wide variety of construction project types to analyse and visualize the strengths, weaknesses and opportunities in their BIM adoption efforts, potentially enabling them to focus on social impacts and outcomes rather than on the technological or management actions that intermediate stakeholders promote. 相似文献
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One of the important measures of post-earthquake functionality of bridges after a major earthquake is residual displacement. In many recent major earthquakes, large residual displacements resulted in demolition of bridge piers due to the loss of functionality. Replacing the conventional longitudinal steel reinforcement in the plastic hinge regions of bridge piers with super-elastic shape memory alloy (SMA) could significantly reduce residual deformations. In this study, numerical investigations on the performance of SMA-reinforced concrete (RC) bridge bents to monotonic and seismic loadings are presented. Incremental dynamic analyses are conducted to compare the response of SMA RC bents with steel RC bents considering the peak and the residual deformations after seismic events. Numerical study on multiple prototype bridge bents with single and multiple piers reinforced with super-elastic SMA or conventional steel bars in plastic hinge regions is conducted. Effects of replacement of the steel rebar by SMA rebar on the performance of the bridge bents are studied. This paper presents results of the parametrical analyses on the effects of various design and geometric parameters, such as the number and geometry of piers and reinforcement ratio of the RC SMA bridge bents on its performance. 相似文献
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Cu metal matrix composite with Y2W3O12 as a thermal expansion compensator was fabricated by high energy ball milling followed by compaction and sintering, and its thermal properties were explored for the potential applications as heat sinks in electronic industries, high precision optics, and space structures. The volume fraction of reinforcement was varied from 40% to 70% in order to tailor the composite for the simultaneous accomplishment of low thermal expansion and high thermal conductivity. The synthesis technique was optimized by varying the parameters like milling time from 1 to 20 h and sintering temperature from 600 to 1000 °C in order to achieve densified composites. The relative density of the composites is found to be around 90% for the 10 h milled powders followed by compaction at a pressure of 700 MPa and sintering at a temperature of 1000 °C. The thermal expansion of the composites exhibits linear behavior in the temperature range 200 to 800 °C and the low coefficient of thermal expansion (CTE) is found to be for Cu–70%Y2W3O12 composite whose value, 4.32±0.75×10−6/°C, matches with that of Si substrate. The thermal conductivities are found to increase with a decrease in the volume fraction of the reinforcement and decrease with an increase in the temperature for all the samples. The experimentally determined CTE and thermal conductivity values are found to be comparable to those predicted by the thermal expansion based Kerner and Turner model and the thermal conductivity based Maxwell model, respectively. 相似文献
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Sanjay Paul Rajeev Shrestha T. N. J. I. Edison Yong Rok Lee Sung Hong Kim 《Advanced Synthesis \u0026amp; Catalysis》2016,358(19):3050-3056
An efficient protocol for the direct sulfanylation of various 4‐hydroxycoumarins and 4‐hydroxyquinolinones in good yield with arylsulfonylhydrazides as sulfanylating agents was developed via copper(I) bromide⋅dimethyl sulfide‐catalyzed S–O, S–N bond cleavage and C–S cross‐coupling reactions. A highly selective fluorescence turning‐on sensing of cadmium(II) ions in water using the synthesized 3‐sulfanyl‐4‐hydroxycoumarin derivative was also investigated.