检索结果-南通市图书馆

Multiple Soliton Asymptotics in a Spin-1 Bose–Einstein Condensate

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

Chinese Physics Letters 2024年第9期41卷 15-22页

作者： zhong-Zhou Lan School of Computer Information Management Inner Mongolia University of Finance and EconomicsHohhot 010070China

Spinor Bose–Einstein condensates(BECs)are formed when atoms in the multi-component BECs possess single hyperfine spin states but retain internal spin degrees of *** study concentrates on a(1+1)-dimensional three-couple Gross–Pitaevskii system to depict the macroscopic spinor BEC waves within the meanfield *** the distribution of the atoms corresponding to the three vertical spin projections,a known binary Darboux transformation is utilized to derive the𝑁matter-wave soliton solutions and triple-pole matter-wave soliton solutions on the zero background,where𝑁is a positive *** those multiple matterwave solitons,the asymptotic analysis is performed to obtain the algebraic expressions of the soliton components in the𝑁matter-wave solitons and triple-pole matter-wave *** asymptotic results indicate that the matter-wave solitons in the spinor BECs possess the property of maintaining their energy content and coherence during the propagation and ***,in the𝑁matter-wave solitons,each soliton component contributes to the phase shifts of the other soliton components;and in the triple-pole matter-wave solitons,stable attractive forces exist between the different matter-wave soliton *** multiple matter-wave solitons are graphically illustrated through three-dimensional plots,density plot and contour plot,which are consistent with the asymptotic analysis *** present analysis may provide the explanations for the complex natural mechanisms of the matter waves in the spinor BECs,and may have potential applications in designs of atom lasers,atom interferometry and coherent atom transport.

关键词： soliton solitons asymptotic

The Effect of Moisture in Different Altitude Layers on the Eastward Propagation of MJO

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2024年第3期38卷 437-452页

作者： Xiaoyu ZHU zhong zhong Yimin ZHU Yunying LI Yijia HU Yao HA College of Meteorology and Oceanography National University of Defense TechnologyChangsha410000China Key Laboratory for Virtual Geographic Environment School of Geography ScienceNanjing Normal UniversityNanjing210023China Jiangsu Collaborative Innovation Center for Climate Change School of Atmospheric SciencesNanjing UniversityNanjing210000China

In this study,driven by ERA5 reanalysis data,the Weather Research and Forecasting(WRF)version 4.0 was used to investigate the eastward propagation of the Madden-Julian oscillation(MJO)in the tropical atmosphere during December-February(DJF)of 2007/*** experiment with 11 cumulus parameterization schemes respectively shows that the Grell 3D scheme is one of several worse ones in describing MJO *** addition,still by use of the Grell 3D scheme,four nudging assimilation experiments for water vapor in all model vertical layers(Ndg_all),lower layers(Ndg_low),middle layers(Ndg_mid),and upper layers(Ndg_upp)were *** is found that when the water vapor in the model approaches to the observed value,the model performance for MJO activities is improved *** the four nudging simulations,Ndg_all certainly performs *** Ndg_mid is important for the MJO-filtered profiles related to moisture,Ndg_low and Ndg_upp exhibit superiority to Ndg_mid in simulating MJO eastward ***_low has advantages when MJO features are represented by zonal wind at 850 hPa and precipitation because the lower-level MJO-filtered moisture is conducive to the existence of lower-level condensational heating to the east of the MJO convective ***_upp performs better when describing the MJO eastward propagation features by outgoing longwave radiation(OLR)since it can capture the moisture and cloud top temperature of deep convection associated with MJO,as well as front Walker *** results suggest that the lower-level moisture is more important in regulating the MJO eastward propagation,and the observed maximum MJO-filtered moisture in the middle troposphere might be a phenomenon accompanying the MJO deep convection,but not a factor controlling its eastward propagation.

关键词： Madden-Julian oscillation(MJO) nudging technique Weather Research and Forecasting(WRF)model vertical moisture structure

在线全文

学校读者我要写书评

暂无评论

自更新记忆网络在降水预报中的应用

青海大学学报 2023年第5期41卷 93-101页

作者：高嘉辉钟德钰青海大学土木水利学院青海西宁810016 青海大学三江源生态与高原农牧业国家重点实验室青海西宁810016 清华大学水圈科学与水利工程全国重点实验室北京100084 清华大学水利部水圈科学重点实验室北京100084 清华大学水利水电工程系北京100084

为提高宁夏回族自治区多流域范围内长期降水预报的准确度,本文以宁夏回族自治区10个3级流域为研究区域,提出含有自更新记忆细胞的自注意记忆-窥孔连接-卷积长短时序网络,采用整层水汽通量为降水预报因子,月降水为预测对象,选用回归与分... 详细信息

为提高宁夏回族自治区多流域范围内长期降水预报的准确度,本文以宁夏回族自治区10个3级流域为研究区域,提出含有自更新记忆细胞的自注意记忆-窥孔连接-卷积长短时序网络,采用整层水汽通量为降水预报因子,月降水为预测对象,选用回归与分类共9项评价指标,探究新方法的适用性。结果表明:相对于其他3种方法,NCMSAM-Peephole-ConvLSTM方法预测精度最高,MAE下降12.0%,RMSE下降10.0%,CORR提升6.2%,MSLE降低61.8%,NSE提升12.8%;阈值在25 mm以内时,NCMSAM-Peephole-ConvLSTM方法、SAM-Peephole-ConvLSTM方法的POD、CSI、HSS中位数均高于其他2种方法。4种方法中NCMSAM-Peephole-ConvLSTM方法预报准确度最高,其次为SAM-Peephole-ConvLSTM方法,ConvLSTM与ConvGRU方法效果较差。

关键词：降水预报深度学习自注意机制卷积长短时序网络

New Results in Cooperative Adaptive Optimal Output Regulation

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 253-272页

作者： DONG Yuchen GAO Weinan JIANG zhong-Ping State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China Department of Electrical and Computer Engineering Tandon School of EngineeringNew York UniversityBrooklynNY 11201USA

This paper investigates the cooperative adaptive optimal output regulation problem of continuous-time linear multi-agent *** the multi-agent system dynamics are uncertain,solving regulator equations and the corresponding algebraic Riccati equations is challenging,especially for high-order *** this paper,a novel method is proposed to approximate the solution of regulator equations,i.e.,gradient descent *** is worth noting that this method obtains gradients through online data rather than model information.A data-driven distributed adaptive suboptimal controller is developed by adaptive dynamic programming,so that each follower can achieve asymptotic tracking and disturbance ***,the effectiveness of the proposed control method is validated by simulations.

关键词： Adaptive dynamic programming cooperative output regulation gradient descent method multi-agent systems.

Tuning Surface Molecular Design of Porous Carbon for Blue Energy Harvesting

在线全文

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 651-662页

作者： Jian Yu zhong-Lin Wang Tianwei Ma Department of Civil and Environmental Engineering University of Hawaii at MānoaHonoluluHI 96822USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Engineering Texas A&M University-Corpus ChristiCorpus ChristiTX 78412USA

Capacitive mixing is a promising blue energy technology due to its membrane-free electricity generation and long electrode life ***,because of limited performance,existing systems do not lend themselves to practical *** it is a crucial factor directly influencing electrode behavior,surface chemistry has largely been overlooked in capacitive ***,we show that manipulating surface functionalization alone can tune the responses of electrodes to produce a high voltage rise without altering the pore structure of the *** findings reveal that the spontaneous electrode potential of a surface-modified carbon electrode shifts negatively proportional to the surface charge due to the surface groups,which explains why and how manipulating the surface chemistry can improve the power generation capacity.

关键词： electrode Porous mixing

Dark Localized Waves in Shallow Waters:Analysis within an Extended Boussinesq System

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

Chinese Physics Letters 2024年第4期41卷 32-37页

作者： Zhengping Yang Wei-Ping zhong Milivoj Belic Department of Medical Science Shunde PolytechnicShunde 528300China Department of Electronic Engineering Shunde PolytechnicShunde 528300China Division of Arts and Sciences Texas A&M University at Qatar23874 DohaQatar

We study dark localized waves within a nonlinear system based on the Boussinesq approximation,describing the dynamics of shallow water *** symbolic calculus,we apply the Hirota bilinear method to transform an extended Boussinesq system into a bilinear form,and then use the multiple rogue wave method to obtain its dark rational *** the first-and second-order dark solutions,we examine the conditions under which these localized solutions exist and their spatiotemporal *** the selection of various parameters and by utilizing different visualization techniques(intensity distributions and contour plots),we explore the dynamical properties of dark solutions found:in particular,the first-and second-order dark rogue *** also explore the methods of their *** findings presented here not only deepen the understanding of physical phenomena described by the(1+1)-dimensional Boussinesq equation,but also expand avenues for further *** method can be extended to other nonlinear systems,to conceivably obtain higher-order dark rogue waves.

关键词： Boussinesq bilinear nonlinear

Study on 6-DOF active vibration-isolation system of the ultra-precision turning lathe based on GA-BP-PID control for dynamic loads

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 33-60页

作者： Bo Wang zhong Jiang Pei-Da Hu Department of Precision Instrument Tsinghua UniversityBeijing100084People’s Republic of China Institute of Machinery Manufacturing Technology China Academy of Engineering PhysicsMianyang621900SichuanPeople’s Republic of China

The vibration disturbance from an external environment affects the machining accuracy of ultra-precision machining *** active vibration-isolation systems(AVIS)have been developed based on static *** a vibration-isolation load changes dynamically during ultra-precision turning lathe machining,the system parameters change,and the efficiency of the active vibration-isolation system based on the traditional control strategy *** solve this problem,this paper proposes a vibration-isolation control strategy based on a genetic algorithm-back propagation neural network-PID control(GA-BP-PID),which can automatically adjust the control parameters according to the machining ***-isolation simulations and experiments based on passive vibration isolation,a PID algorithm,and the GA-BP-PID algorithm under dynamic load machining conditions were *** experimental results demonstrated that the active vibration-isolation control strategy designed in this study could effectively attenuate vibration disturbances in the external environment under dynamic load *** design is reasonable and feasible.

关键词： Ultra-precision diamond turning lathe Active vibration isolation Six degrees of freedom Dynamic load Genetic algorithm-back propagation neural network-PID(GA-BP-PID)control

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

多源数据驱动的黄河未来水沙变化趋势研究

水力发电学报 2021年第5期40卷 99-109页

作者：李雅娟张宇田颖琳张青青钟德钰青海大学水利电力学院西宁810016 清华大学水沙科学与水利水电工程国家重点实验室北京100084 青海大学省部共建三江源生态与高原农牧业国家重点实验室西宁810016

由于近年来气候变化和人类活动的双重影响,导致黄河水沙锐减,对未来变化趋势作出可靠判断十分必要。利用基于多种机器学习特征筛选的统计模型方法,采用潼关站实测径流量与输沙量、欧洲中期天气预报中心中尺度数据及不同气候变化路径的CO... 详细信息

由于近年来气候变化和人类活动的双重影响,导致黄河水沙锐减,对未来变化趋势作出可靠判断十分必要。利用基于多种机器学习特征筛选的统计模型方法,采用潼关站实测径流量与输沙量、欧洲中期天气预报中心中尺度数据及不同气候变化路径的CO_(2)排放浓度下全球气候模式数据对未来水沙作了预测。结果表明,在rcp26情景下,潼关站未来10年、20年、50年的断面径流量为234.21亿m^(3)、227.52亿m^(3)、219.6亿m^(3),与2000—2016年平均径流量228.86亿m^(3)相比,径流量增加了约2.3%、-0.5%、4.0%;同期的断面输沙量预测结果为2.68亿t、3.44亿t、5.72亿t,与2000—2016年平均输沙量2.48亿t相比增加了约7.9%、38.4%、130.2%,表明黄河流域"水少沙多"的形势依然是未来较长一个时期的主要特征。

关键词：黄河水沙预测多元回归分析数据驱动

在线全文

学校读者我要写书评

暂无评论

中小流量下黄河下游游荡段河床调整规律

水力发电学报 2020年第4期39卷 33-45页

作者：景唤钟德钰张红武王彦君黄海清华大学水沙科学与水利水电工程国家重点实验室北京100084 青海大学省部共建三江源生态与高原农牧业国家重点实验室西宁810016 长江科学院水利部江湖治理与防洪重点实验室武汉430010 中国水利水电科学研究院北京100038

小浪底水库运用后,进入黄河下游河道的水沙情势发生显著变化,大流量洪水频率大幅减小,中小流量洪水作用凸显。为揭示黄河下游游荡段中小流量下的演变特征,本文开展了500、1000、1500和2000 m3/s流量级下黑岗口—夹河滩段的动床物理模型... 详细信息

小浪底水库运用后,进入黄河下游河道的水沙情势发生显著变化,大流量洪水频率大幅减小,中小流量洪水作用凸显。为揭示黄河下游游荡段中小流量下的演变特征,本文开展了500、1000、1500和2000 m3/s流量级下黑岗口—夹河滩段的动床物理模型试验。结果表明,垂向上,研究河段河床冲刷与淤积沿程相间分布,具有典型的游荡性河段的冲淤交替特征;横向上,中小流量下游荡段仍存在横向摆动的可能,且随着流量增大,主流弯曲系数由1.18减小至1.13,河道逐渐由蜿蜒向顺直发展;纵向上,各流量下深泓线调整趋势与冲淤量变化规律基本一致。此外,本文着重分析了河道工程与桥下河段河床的时空调整过程并运用随机模型进行了模拟。通过分析发现:时间上,河道工程附近河床垂向调整速率早期较快,之后随时间快速非线性减缓;空间上,桥下河段累积冲刷深度沿程非线性减小,空间衰减特性显著。应用表明,随机模型对典型局部河段的时空调整预测效果较好,相关系数R2可达0.74以上。本文探讨了中小流量下黄河下游典型游荡段长河段与局部的冲淤演变特征,可为未来黄河下游典型游荡性河段的河道整治与保护提供科学依据。

关键词：黄河下游游荡段河道冲淤模型试验横向摆动局部演化