检索结果-南通市图书馆

Theoretical study of ion-molecule collision: dynamics, cross sections, and dissociation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Theoretical study of ion-molecule collision: dynamics, cross...

Four Late-type Galaxies with Double Radio Lobes and Properties of Such Galaxies

第七届全国计算原子与分子物理学术会议

作者： W.Yu C.-z.gao Y.Wu B.Wei Institute of Modern Physics Fudan University Key Laboratory of Nuclear Physics and Ion-beam Application (MOE) Fudan University Institute of Applied Physics and Computational Mathematics

＜正＞Using time-dependent density-functional theory coupled non-adiabatically to molecular dynamics（TDDFT-MD）,we investigate the scattering dynamics,cross sections and dissociation in ion-induced *** electronic evolution is described by Kohn-Sham equations and ionic dynamics is treated on the level of classical molecule dynamics according to Ehrenfest theorem.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第4期24卷 84-90页

作者： z.S.Yuan X.Y.gao z.L.Wen J.L.Han National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The triggering mechanism for radio lobes from late-type galaxies is not fully *** samples are desired for a thorough investigation and *** utilizing the optical data from the newly released Dark Energy Spectroscopic Instrument imaging surveys and the radio sources from the NRAO VLA Sky Survey and the Faint Images of the Radio Sky at Twenty-centimeter,we identify four Late-type Galaxies with double Radio Lobes(La GRLs):J0217-3645,J0947+6220,J1412+3723 and J1736+*** previously known La GRLs,we confirm the correlation between radio power P_(1.4GHz)and stellar mass M_(*)of host ***(25/35)La GRLs belong to the blue cloud galaxies,while the newly identified cases in this work are located within the region of the red *** find a clear correlation between the differential radio power,i.e.,the offset from the P_(1.4GHz)-M_(*)relation,and the galaxy color,indicating that bluer galaxies at a fixed M_(*)tend to host more powerful radio ***,the majority(31/36)of La GRLs are either located in a galaxy group or displaying a disturbed *** suggest that all of the galaxy mass,color and surrounding environment could play important roles in triggering radio lobes in late-type galaxies.

关键词： galaxies:active galaxies:jets galaxies:spiral radio continuum:galaxies

基于非线性级联傅里叶变换的光学Hash函数构造

在线全文

学校读者我要写书评

暂无评论

物理学报 2010年第3期59卷 1762-1768页

作者：何文奇彭翔祁永坤孟祥锋秦琬高志深圳大学光电工程学院光电子器件与系统教育部/广东省重点实验室深圳518060 Clemson大学生物医学工程系 501-5 Rhodes Research CenterClemsonSC 29634USA

提出一种基于非线性级联傅里叶变换的光学Hash函数的构造方法.此方法分为两轮单向加密过程,在第一轮中,先将待处理的数字信息以512bit作为数据块编码,将整个数字信息整分成若干个"8×8的256阶灰度图像"(信息平面),然后在光电混合系统中... 详细信息

提出一种基于非线性级联傅里叶变换的光学Hash函数的构造方法.此方法分为两轮单向加密过程,在第一轮中,先将待处理的数字信息以512bit作为数据块编码,将整个数字信息整分成若干个"8×8的256阶灰度图像"(信息平面),然后在光电混合系统中对上述信息平面组做非线性级联傅里叶变换得到一个数值矩阵,对其进行扩展后得到4个信息平面,再对它们做非线性级联傅里叶变换得到64bit的Hash值(hash1);在第二轮中,先将原始信息平面中的每个数值循环左移4位,构造出相应的辅助信息平面组,然后对其做与第一轮相同的单向加密操作,得到hash2,将其与之前生成的hash1组合起来构成最终128bit的Hash值(hash).同时,本文提出采用雪崩效应系数(AEC)作为评价光学Hash函数性能的参数,理论分析和仿真实验均表明,该方法构造的光学Hash函数具有很好的抗碰撞性和良好的雪崩效应.

关键词：信息光学光学Hash函数非线性级联傅里叶变换雪崩效应

背对背连接的土工合成材料加筋土挡墙的分析与设计

在线全文

学校读者我要写书评

暂无评论

路基工程 1997年第6期 78-85页

作者： S.C.R.Lo S.Q.Li M.Gopalan z.gao 孙增生铁道部科学研究院西北分院

本文研究了承受由轨道传来的重型滞留超载的背对背连接的土工合成材料加筋土挡墙的设计。挡墙设计中使用了简化法则,应用非线性有限元分析,研究了临界断面。发现背对背连接挡墙的应力、应变场与普通加筋土挡墙的完全不同。然而,如果在... 详细信息

本文研究了承受由轨道传来的重型滞留超载的背对背连接的土工合成材料加筋土挡墙的设计。挡墙设计中使用了简化法则,应用非线性有限元分析,研究了临界断面。发现背对背连接挡墙的应力、应变场与普通加筋土挡墙的完全不同。然而,如果在所提供的刚度范围内使用土工合成材料加固,那么简化设计准则就给出一种偏小的加筋张力和相对于有限元结果的连结力系数。如果采用金属加筋,有限元分析预测的加筋张力就大得多,这种差异是由于背对背连结挡墙对加筋刚度的依赖性而引起的。

关键词：铁路加筋土挡土墙土工合成材料分析设计

Post-layout simulation driven analog circuit sizing

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第4期67卷 289-300页

作者： Xiaohan gao Haoyi zHANG Siyuan YE Mingjie LIU David z.PAN Linxiao SHEN Runsheng WANG Yibo LIN Ru HUANG School of Integrated Circuits Peking University School of Computer Science Peking University Department of Electrical and Computer Engineering University of Texas at Austin Institute of Electronic Design Automation Peking University

Post-layout simulation provides accurate guidance for analog circuit design, but post-layout performance is hard to be directly optimized at early design stages. Prior work on analog circuit sizing often utilizes pre-layout simulation results as the optimization objective. In this work, we propose a post-layoutsimulation-driven(post-simulation-driven for short) analog circuit sizing framework that directly optimizes the post-layout simulation performance. The framework integrates automated layout generation into the optimization loop of transistor sizing and leverages a coupled Bayesian optimization algorithm to search for the best post-simulation performance. Experimental results demonstrate that our framework can achieve over 20% better post-layout performance in competitive time than manual design and the method that only considers pre-layout optimization.

关键词： analog EDA transistor sizing Bayesian optimization post-layout simulation

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第1期21卷 82-90页

作者： Kun gao Yan Peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第5期31卷 1117-1126页

作者： Kun gao Yan Peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast *** lower level height tends to entrap inclusions in the molten *** the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was *** transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid *** results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the *** is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in *** jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation zone on the inside radius and the outside radius respectively,according to the 10 s time-averaged *** with the industrial observation and simulation results,the shape of the free surface is a wave that varies with *** addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

Topological and superconducting properties of monolayered CoN and CoP:A first-principles comparative study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 98-108页

作者： Jiaqing gao zhenyu zhang Ping Cui International Center for Quantum Design of Functional Materials(ICQD) Hefei National Research Center for Physical Sciences at Microscale(HFNL)University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum ***,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to *** two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero z2 topological invariant in each *** a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band ***,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced *** different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon *** central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.

关键词： topological yielding otherwise

对于慢性心肌梗死非增强心脏MRI诊断的深入学习

在线全文

学校读者我要写书评

暂无评论

国际医学放射学杂志 2019年第4期 486-486页

作者：陈萍 N.zhang G.Yang z.gao C.Xu Y.zhang R.Shi Department of Radiology Beijing Anzhen HospitalCapital Medical University

摘要肾脏损害在冠心病病人中很常见,如果严重的话,延迟钆增强(LGE)成像则不能用于对心肌梗死的评估。目的通过对非增强心脏MR的深入学习,开发一个用于描绘慢

关键词：心肌梗死 MRI 深入学习