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排序方式: 共有6442条查询结果,搜索用时 31 毫秒
1.
Mehdi Hosseini Abadshapoori 《亚洲传热研究》2021,50(2):1056-1072
Increasing the heat capacity of heat exchangers is a crucial need for modern devices. The thermal conductivity of the usual fluids and the Nusselt (Nu) number of flows containing such fluids are two bottlenecks in the way of increasing heat delivery in the heat exchangers. For this reason, nanofluids have been introduced. The effect of utilizing a Cu-water nanofluid as a coolant of two hot pipes in a square cavity is investigated numerically with a two-component lattice Boltzmann method. The volume fraction of nanoparticles is assumed to be constant (0.03) while the Richardson (Ri) number varies from 0.02 to 20. Results show that the effectiveness of nanoparticles is better observed in the natural convection mode. However, sedimentation is also very probable at high Ri numbers, which significantly reduces the effectiveness of the nanoparticles. Configurations which produce a natural convection stream similar to the forced convection one as well as the configurations with high spacing and hence, low heat stream interactions, are the best choices for a uniform heat rate from the pipes. 相似文献
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As the development of cloud computing and the convenience of wireless sensor netowrks, smart devices are widely used in daily life, but the security issues of the smart devices have not been well resolved. In this paper, we present a new NTRU-type public-key cryptosystem over the binary field. Specifically, the security of our scheme relies on the computational intractability of an unbalanced sparse polynomial ratio problem (DUSPR). Through theoretical analysis, we prove the correctness of our proposed cryptosystem. Furthermore, we implement our scheme using the NTL library, and conduct a group of experiments to evaluate the capabilities and consuming time of encryption and decryption. Our experiments result demonstrates that the NTRU-type public-key cryptosystem over the binary field is relatively practical and effective. 相似文献
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ObjectiveTraffic collisions yield a substantial rate of morbidity and injury among child-pedestrians. We explored the formation of an innovative hazard perception training intervention – Child-pedestrians Anticipate and Act Hazard Perception Training (CA2HPT). Training was based upon enhancing participants’ ability to anticipate potential hazards by exposing them to an array of traffic scenes viewed from different angles.MethodTwenty-four 7–9-year-olds have participated. Trainees underwent a 40-min intervention of observing typical residential traffic scenarios in a simulated dome projection environment while engaging in a hazard detection task. Trainees were encouraged to note differences between the scenarios presented to them from separate angles (a pedestrian's point-of-view and a higher perspective angle). Next, trainees and control group members were required to perform crossing decision tasks.ResultsTrainees were found to be more aware of potential hazards related to restricted field of view relative to control.ConclusionsChild pedestrians are responsive to training and actively detecting materialized hazards may enrich child-pedestrians’ ability to cross roads. 相似文献
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膨化硝酸铵晶体特性研究 总被引:4,自引:0,他引:4
膨化硝酸铵是一种改性硝酸铵晶体,具有显著自敏化特征,成功应用于各类膨化硝铵炸药及震源药柱中.在膨化剂(表面活性剂)的作用下改善了膨化硝酸铵的物理性能和晶体结构及其特征.本文通过硝酸铵固体表面接触角的测量,算出了膨化硝酸晶体表面能;利用差热分析(DSC)技术给出了膨化剂对硝酸铵晶变的影响;采用x射线衍射分析了膨化硝酸铵晶体的晶格特性. 相似文献
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文中介绍了预应力钢筒混凝土管的概念、优越性,并结合山西省万家寨联接段引黄工程的实际施工,总结出了穿越各种地下管线的施工经验。 相似文献
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R. A. Borzooei M. Bakhshi M. Mashinchi 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2008,12(8):739-749
In this paper, we study the lattice structure of some fuzzy algebraic systems such as (G-)fuzzy groups, some fuzzy ordered
algebras and fuzzy hyperstructures. We prove that under suitable conditions, these structures form a distributive or modular
lattice.
This research partially is supported by the “ Fuzzy Systems and its Applications Center of Excelence, Shahid Bahonar University
of Kerman, Iran”. 相似文献