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基于CFD方法的对拍扑翼推进特性分析 被引量:5
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作者 张伟伟 徐杨 +1 位作者 蒋跃文 叶正寅 《空气动力学学报》 CSCD 北大核心 2014年第4期446-452,共7页
双翼对拍推进相对于单扑翼推进具有效率高,机械设计容易,升力和惯性力平稳的特点。论文采用雷诺平均NS方程和非结构混合运动网格方法求解非定常流场,以NACA0012翼型为例,研究了低速状态下双翼对拍时沉浮运动的振幅、频率、双翼的间距以... 双翼对拍推进相对于单扑翼推进具有效率高,机械设计容易,升力和惯性力平稳的特点。论文采用雷诺平均NS方程和非结构混合运动网格方法求解非定常流场,以NACA0012翼型为例,研究了低速状态下双翼对拍时沉浮运动的振幅、频率、双翼的间距以及沉浮俯仰两自由度相角差等参数对推进效率和推进系数的影响。研究发现,相对单扑翼推进,双翼对拍能够得到更大的推力和更高的推进效率。附加俯仰自由度后,选择合适的沉浮和俯仰相角差,两自由度组合扑动系统的推进性能相比单纯沉浮扑动系统又将进一步得到提高。 展开更多
关键词 扑翼推进 双翼对拍 数值模拟 非定常流场
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“对拍”方法在程序验证中的应用
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作者 谢玉韬 徐剑 李庆英 《电脑知识与技术》 2022年第18期45-47,共3页
在编程实践中,如何验证所写程序是否正确有很多方法,“对拍”是常用的一种。介绍了“对拍”的基本概念、应用场景,以两个数求和为例详细说明了“对拍”的过程,在此基础上使用Java语言开发了图形用户界面的判题工具,该工具利用对拍原理,... 在编程实践中,如何验证所写程序是否正确有很多方法,“对拍”是常用的一种。介绍了“对拍”的基本概念、应用场景,以两个数求和为例详细说明了“对拍”的过程,在此基础上使用Java语言开发了图形用户界面的判题工具,该工具利用对拍原理,基于给定多组样例数据,对用户提交的程序的正确性进行验证并给出反例,操作界面友好,操作方便,提高了程序验证的效率。 展开更多
关键词 程序验证 对拍 JAVA语言 图形化工具
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Quantum Secure Direct Communication and Quantum Sealed-Bid Auction with EPR Pairs 被引量:4
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作者 王章银 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第12期997-1002,共6页
I present a new protocol for three-party quantum secure direct communication (QSDC) with a set of ordered M Einstein-Podolsky-Rosen (EPR) pairs. In the scheme, by performing two unitary operations and Bell state m... I present a new protocol for three-party quantum secure direct communication (QSDC) with a set of ordered M Einstein-Podolsky-Rosen (EPR) pairs. In the scheme, by performing two unitary operations and Bell state measurements, it is shown that the three legitimate parties can exchange their respective secret message simultaneously. Then I modify it for an experimentally feasible and secure quantum sealed-bid auction (QSBD) protocol. Furthermore, I also analyze th^ecurity of the protocol, and the scheme is proven to be secure against the intercept-and-resend attack, the disturbancb attack and the entangled-and-measure attack. 展开更多
关键词 Einstein-Podolsky-Rosen (EPR) pairs quantum secure direct communication quantum sealedbid auction Bell state measurement unitary operation
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Howarcl Koberts' Hypatta oJ Alexanclrta: A Form of Neoplatonic Beauty 被引量:1
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作者 Liana De Girolami Cheney 《Journal of Literature and Art Studies》 2014年第12期1080-1092,共13页
This essay examines an American 19th-century sculpture, Howard Roberts' Hypatia, both historically and aesthetically (see Figures 1 and 2). Problems of interpretation are found at both levels because of limited doc... This essay examines an American 19th-century sculpture, Howard Roberts' Hypatia, both historically and aesthetically (see Figures 1 and 2). Problems of interpretation are found at both levels because of limited documentation. However, a speculative analysis adapting Plotinus' notions on the "delight of the intellect" and of "seeing" assist in considering beauty in the carved form, even if the subject is grave. What prompted this commission and who commissioned this work are questions to be considered. 展开更多
关键词 19th Century American Sculpture Howard Roberts Hypatia NEOPLATONISM PHILADELPHIA
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Buckling and post-buckling of rotationally restrained columns with imperfections
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作者 CAI JianGuo XU YiXiang +1 位作者 FENG Jian ZHANG Jin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第8期1519-1522,共4页
The stability of imperfect columns has been studied by many researchers. Often the ends of a column are not necessarily fixed or pin-ended for practical structures. Therefore, rotationally restrained columns having an... The stability of imperfect columns has been studied by many researchers. Often the ends of a column are not necessarily fixed or pin-ended for practical structures. Therefore, rotationally restrained columns having an initial imperfection in an asymmetric mode have been studied in this paper. An elastic formula using the large deflection theory was given, and the shooting method was used to obtain the equilibrium paths and critical loads. Then the relationship between the end rotation and rotational restraints has been studied and discussed followed by a detailed discussion on the influence of imperfection on the column behaviour. 展开更多
关键词 COLUMNS BUCKLING IMPERFECTIONS structural stability supports
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Attacks and Improvement of Quantum Sealed-Bid Auction with EPR Pairs 被引量:3
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作者 刘文杰 王芳 +2 位作者 季赛 瞿治国 王小军 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第6期686-690,共5页
Recently, an experimentally feasible three-party quantum sealed-bid auction protocol based on EPR pairs [Z.Y. Wang, Commun. Theor. Phys. 54 (2010) 997] was proposed. However, this study points out Wang's protocol c... Recently, an experimentally feasible three-party quantum sealed-bid auction protocol based on EPR pairs [Z.Y. Wang, Commun. Theor. Phys. 54 (2010) 997] was proposed. However, this study points out Wang's protocol cannot resist some internal bidders' attacks, such as the Twiee-CNOT attack, the collusion attack. A malicious bidder can launch the Twice-CNOT attack to obtain the other's bid, or the dishonest auctioneer may collude with one bidder and help him/her win the action by changing his/her bid. For preventing against these attacks, a simple solution by using the QKD-based message encryption and a post-confirmation mechanism by adopting the hash function are proposed. 展开更多
关键词 quantum sealed-bid auction EPR pairs twice-CNOT attack collusion attack IMPROVEMENT
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