检索结果-南通市图书馆

Breaking the efficiency limitations of dissipative Kerr solitons using nonlinear couplers

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 88-94页

作者： Ming Li Xiao-Xiao Xue Yan-Lei Zhang Xin-Biao Xu chun-hua Dong Guang-Can Guo Chang-Ling Zou CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Centerfor Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Department of Electronic Engineering Beijing National Research Center for Information Science and TechnologyTsinghua University Beijing 100084China

Dissipative Kerr solitons(DKS) have long been suffering from poor power conversion efficiency when driven by continuous-wave lasers. By deriving the critical coupling condition of a multimode nonlinear optics system in a generalized theoretical framework,two efficiency limitations of the conventional pump method of DKS are revealed: the effective coupling rate is too small and is also power-dependent. A general approach is provided to resolve this challenge by introducing two types of nonlinear couplers to couple the soliton cavity and CW input through nonlinear processes. The collective coupler opens multiple coupling channels and the self-adaptive coupler builds a power-independent effective external coupling rate to the DKS for approaching the generalized critical coupling condition, which promises near-unity power conversion efficiencies. For instance, a conversion efficiency exceeding 90% is predicted for aluminum nitride microrings with a nonlinear coupler utilizing second-harmonic generation. The mechanism applies to various nonlinear processes, including Raman and Brillouin scattering, and thus paves the way for micro-solitons toward practical applications.

关键词： Kerr frequency comb conversion efficiency nonlinear coupler

在线全文

学校读者我要写书评

暂无评论

当地DFD方法在扑翼流动数值模拟中的应用

计算力学学报 2013年第6期30卷 815-821页

作者：刘冠冕周春华艾俊强南京航空航天大学空气动力学系南京210016 中航通用飞机设计研究院珠海519040 中国航空工业集团第一飞机设计研究院西安710089

应用当地DFD(Domain-Free Discretization)方法对包含复杂运动边界的扑翼流场进行了数值模拟。该方法通过壁面法线方向的外插确定外部相关点上的流动变量值,同时强加相应的边界条件。应用这种方法,动边界流动的模拟可以在固定网格上实现... 详细信息

应用当地DFD(Domain-Free Discretization)方法对包含复杂运动边界的扑翼流场进行了数值模拟。该方法通过壁面法线方向的外插确定外部相关点上的流动变量值,同时强加相应的边界条件。应用这种方法,动边界流动的模拟可以在固定网格上实现,无需为了跟随物体的运动而在每个时间步上对网格进行实时更新。对三种拍动模式的双翅流场进行了数值模拟,升、阻力系数时间历程的计算结果与参考文献的实验数据吻合很好,验证了当地DFD方法处理复杂动边界问题的可靠性。最后,数值模拟了完整昆虫模型的扑翼流场,并详细分析了涡系结构和飞行机理。

关键词：边界非协调方法动边界问题扑翼流动边界嵌入方法非定常流动

腹部开放伤合并海水浸泡致急性肾衰犬模型的建立

在线全文

学校读者我要写书评

暂无评论

军医进修学院学报 2007年第2期28卷 135-137页

作者：李昕周春华海军总医院肾内科北京100037

目的:建立腹部开放伤合并海水浸泡致急性肾功能衰竭动物模型,为海战伤的研究提供技术平台。方法:成年杂种犬20只,致腹部开放伤后随机分为海水浸泡组和对照组,每组10只。观察各时间点生存率、体温、血压、肾功、血气、渗透压、病理等变... 详细信息

目的:建立腹部开放伤合并海水浸泡致急性肾功能衰竭动物模型,为海战伤的研究提供技术平台。方法:成年杂种犬20只,致腹部开放伤后随机分为海水浸泡组和对照组,每组10只。观察各时间点生存率、体温、血压、肾功、血气、渗透压、病理等变化。结果:经过海水浸泡后,动物立即出现低血压、低温、高渗,然后逐渐出现代谢性酸中毒,血肌酐和血尿素氮逐渐升高,病理也出现急性肾衰竭表现,与对照组比较有显著性差别(P<0.05)。结论:该模型具备战伤合并海水浸泡的伤情变化特点,出现了典型的急性肾衰的病情特点,可行且重复性好,适用于海战伤致急性肾衰的病理生理和相应治疗手段的研究。

关键词：肾功能衰竭,急性创伤海水浸泡动物模型

Pulsations of Three Rapidly Oscillating Ap Stars TIC 96315731,TIC72392575,and TIC 318007796

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第8期24卷 157-168页

作者： Hai-Jian Zhong Dong-Xiang Shen chun-hua Zhu He-Lei Liu Su-Fen Guo Guo-Liang Lü School of Physical Science and Technology Xinjiang UniversityUrumqi 830046China Xinjiang Astronomical Observatory National Astronomical ObservatoriesChinese Academy of SciencesUrumqi 830000China

We analyze the frequencies of three known roAp stars,TIC 96315731,TIC 72392575,and TIC 318007796,using the light curves from the Transiting Exoplanet Survey *** TIC 96315731,the rotational and pulsational frequencies are 0.1498360 day^(-1)and 165.2609 day^(-1),*** the case of TIC 72392575,the rotational frequency is 0.25551 day^(-1).We detect a quintuplet of pulsation frequencies with a center frequency of135.9233 day^(-1),along with two signals within the second pair of rotational sidelobes of the quintuplet separated by the rotation *** two signals may correspond to the frequencies of a dipole *** TIC318007796,the rotational and pulsational frequencies are 0.2475021 day^(-1),192.73995 day^(-1),and196.33065 day^(-1),*** on the oblique pulsator model,we calculate the rotation inclination(i)and magnetic obliquity angle(b)for the stars,which provide the geometry of the pulsation *** the phases of the frequency quintuplets,the pulsation amplitude and phase modulation curves,and the results of spherical harmonic decomposition,we conclude that the pulsation modes of frequency quintuplets in TIC96315731,TIC 72392575,and TIC 318007796 correspond to distorted dipole mode,distorted quadrupole mode,and distorted dipole mode,respectively.

关键词： asteroseismology-techniques photometric-stars oscillations(including pulsations)-stars chemically peculiar

Radical involved reactive wetting and retarding mechanism of alumina refractory ceramic by molten slags under weak static magnetic field

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6期31卷 1355-1366页

作者： Sheng-hao Li Ao huang Fan-bo Zeng Hui Peng Hao-ran Wei Xue-chun huang Sheng-qiang Song hua-zhi Gu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

High alumina slag will cause severe corrosion at the interface of alumina refractory,and the wetting behavior of slag is a key factor influencing the corrosion resistance of refractory *** static magnetic field is a promising solution for improvement in the slag resistance of *** wetting of alumina refractory ceramics with different basicities of high alumina slags under a weak static magnetic field was analyzed,given that a weak static magnetic field can affect the corrosion behavior of refractory *** slag S_(3) as an example,when there was an external static magnetic field of 1.0 mT at 1600 ℃,the thickness of calcium aluminate reaction layer at the interface decreased by 36.7%,the denting depth of interface decreased by 35.6%,and the apparent wetting angle increased by 20%.The living radicals and their formation path in oxide melts were verified by first-principles calculation combined with electron paramagnetic resonance spectroscopy *** influence of the flux density of a weak static magnetic field on the wetting behavior of slags was also *** contact angle of the slags increased owing to the inhibitory effect of magnetic field on the radicalinvolved reaction at the interface of the slag and the alumina refractory *** relationships between the magnetic flux density,diffusion coefficient,slag microstructure(hyperfine coupling constant),and contact angle were *** provides a theoretical basis for the field control of radical involved reactive wetting between inorganic oxide slags and solid oxide ceramics.

关键词： Alumina refractory ceramic Molten slag Weak magnetic field effect Reactive wetting Free radical

Icariin ameliorates viral myocarditis by inhibiting TLR4-mediated ferroptosis

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

Asian Pacific Journal of Tropical Biomedicine 2024年第3期14卷 106-114,I0002-I0005页

作者： Wei Luo Yi Lu Jun-hua Deng Peng Liu Yan huang Wan-Xi Liu chun-Li huang Laboratory of the Atherosclerosis and Ischemic Cardiovascular Diseases Department of CardiologyAffiliated Hospital of Youjiang Medical University for NationalitiesYoujiang Medical University for NationalitiesBaiseGuangxi 533000China Department of Critical Care Medicine Affiliated Hospital of Youjiang Medical University for NationalitiesBaiseGuangxi 533000China Department of Respiratory and Critical Care Medicine Affiliated Hospital of Youjiang Medical University for NationalitiesBaiseGuangxi 533000China Postgraduate School of Youjiang Medical University for Nationalities BaiseGuangxi 533000China Department of Neonatology Affiliated Hospital of Youjiang Medical University for NationalitiesBaiseGuangxi 533000China Department of Nephrology People’s Hospital of PubeiQinzhouGuangxi 535300China Urban Community Health Service Center of Youjiang District BaiseGuangxi 533000China

Objective:To explore the mechanism by which icariin alleviates viral ***:CVB3-induced cardiomyocytes were used as an in vitro model of viral myocarditis to assess the effects of icariin treatment on cell viability,inflammation,and ***,the effects of icariin on ferroptosis and TLR4 signaling were *** AC16 cells were transfected with TLR4 overexpression plasmids,the role of TLR4 in mediating the regulatory effect of icariin in viral myocarditis was ***:Icariin significantly elevated cell viability and reduced inflammatory factors TNF-α,IL-1β,IL-6,and *** cytometry revealed that icariin decreased apoptosis rate,and the protein expression of Bax and cleaved caspase 3 and 9 in CVB3-induced ***,it suppressed ferroptosis including lipid peroxidation and ferrous ion,as well as the TLR4 ***,TLR4 overexpression abrogated the modulatory effects of ***:Icariin mitigates CVB3-induced myocardial injury by inhibiting TLR4-mediated *** animal study is needed to verify its efficacy.

关键词： Viral myocarditis CVB3 TLR4 Ferroptosis Icariin

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

卫星飞轮隔振与吸振联合减振系统设计

光学精密工程 2014年第4期22卷 897-903页

作者：虞自飞周徐斌申军烽周春华上海卫星工程研究所空间机热一体化技术实验室上海200240

分析了抑制卫星飞轮振动的方法,提出了隔振为主、吸振为辅的联合减振方案。研究了会聚式隔振系统参数对其减振性能的影响;针对会聚式隔振系统存在的不足,提出了圆周分布式吸振方法和相应的吸振系统,分析表明会聚式隔振系统在4个方向的... 详细信息

分析了抑制卫星飞轮振动的方法,提出了隔振为主、吸振为辅的联合减振方案。研究了会聚式隔振系统参数对其减振性能的影响;针对会聚式隔振系统存在的不足,提出了圆周分布式吸振方法和相应的吸振系统,分析表明会聚式隔振系统在4个方向的隔振效率达90%以上。根据会聚式隔振系统在X平动方向隔振效率较低的问题,建立了会聚式隔振和圆周分布式吸振的联合减振系统仿真模型。仿真结果表明,联合减振系统较单纯的隔振系统在X平动方向减振效率提高近50%,且不改变其他方向的减振性能。因此,联合减振设计方法合理可行,适用于卫星飞轮等主要振源的振动抑制,并为飞轮联合减振系统的工程化设计提供了理论支持。

关键词：飞轮圆周分布式减振系统吸振隔振联合减振

在线全文

学校读者我要写书评

暂无评论

智慧标识网络服务机理研究进展及安全性分析

电子学报 2021年第8期49卷 1653-1664页

作者：支婷刘颖周华春张宏科北京交通大学下一代互联网互联设备国家工程实验室北京100044

随着互联网规模的不断扩大以及应用场景的多元化,传统网络无法很好地满足新业务的动态多样化需求,因此国内外对未来网络展开了深入研究.本文首先介绍了未来互联网体系架构的研究现状.其次,介绍了具备“三层、两域”特征的智慧标识网络(S... 详细信息

随着互联网规模的不断扩大以及应用场景的多元化,传统网络无法很好地满足新业务的动态多样化需求,因此国内外对未来网络展开了深入研究.本文首先介绍了未来互联网体系架构的研究现状.其次,介绍了具备“三层、两域”特征的智慧标识网络(Smart Identifier NETwork,SINET)体系架构,然后重点阐述了SINET服务机理在服务的命名与解析、路由机制、服务缓存、移动性、传输控制机制、可扩展性、绿色节能等关键技术方面取得的研究进展,并进一步详细分析了SINET服务机理的安全性.最后总结了SINET面临的挑战,对SINET服务机理在大规模场景部署中可能存在的问题做出讨论.

关键词：智慧标识网络服务机理动态适配安全性

基于身份与位置分离的嵌套移动网络路由优化机制

在线全文

学校读者我要写书评

暂无评论

电子学报 2008年第7期36卷 1261-1267页

作者：杨水根秦雅娟周华春张宏科北京交通大学电子信息工程学院北京100044

基于移动IPv6嵌套移动网络中存在的路由优化问题,本质上是由传统互联网的体系结构造成的.在传统互联网体系结构中,IP地址同时代表了节点的身份标识和位置标识,这种双重功能不利于节点的移动.针对这一问题,本文提出一种身份与位置分离的... 详细信息

基于移动IPv6嵌套移动网络中存在的路由优化问题,本质上是由传统互联网的体系结构造成的.在传统互联网体系结构中,IP地址同时代表了节点的身份标识和位置标识,这种双重功能不利于节点的移动.针对这一问题,本文提出一种身份与位置分离的体系结构,IP地址只作为节点的位置标识,引入端点标识符作为通信双方的身份标识,使得当节点的地址改变时通信双方的连接不中断.在该身份与位置分离体系结构基础上,提出一种嵌套移动网络的路由优化机制,利用封装在IPv6逐跳选项报头中的路由更新选项、路由确认选项和路由删除选项进行路由优化.性能分析结果表明,该机制具有较低的报文开销和路由更新时延.

关键词：嵌套移动网络路由优化身份与位置分离 IPv6逐跳选项报头