检索结果-南通市图书馆

Physical neural networks with self-learning capabilities

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8期67卷 23-42页

作者： Weichao Yu Hangwen guo jiang Xiao jian Shen State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China Zhangjiang Fudan International Innovation Center Fudan UniversityShanghai 201210China Department of Physics Fudan UniversityShanghai 200433China Shanghai Research Center for Quantum Sciences Shanghai 201315China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

Physical neural networks are artificial neural networks that mimic synapses and neurons using physical systems or *** networks harness the distinctive characteristics of physical systems to carry out computations effectively,potentially surpassing the constraints of conventional digital neural networks.A recent advancement known as“physical self-learning”aims to achieve learning through intrinsic physical processes rather than relying on external *** article offers a comprehensive review of the progress made in implementing physical self-learning across various physical *** learning strategies that contribute to the realization of physical self-learning are *** challenges in understanding the fundamental mechanism of learning,this work highlights the progress towards constructing intelligent hardware from the ground up,incorporating embedded self-organizing and self-adaptive dynamics in physical systems.

关键词： self-learning physical neural networks neuromorphic computing physical learning

Variability Analysis for a Two-station Queueing Network in Heavy Traffic with Arrival Processes Driven by Queues

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第2期40卷 445-466页

作者： jian CAO Yong-jiang {2. Kai-ming YANG School of Science Beijing University of Posts and TelecommunicationsBeijing 100876China

The law of the iterated logarithm(LIL)for the performance measures of a two-station queueing network with arrivals modulated by independent queues is developed by a strong approximation *** convenience,two arrival processes modulated by queues comprise the external system,all others are belong to the internal *** is well known that the exogenous arrival has a great influence on the asymptotic variability of performance measures in *** the considered queueing network in heavy traffic,we get all the LILs for the queue length,workload,busy time,idle time and departure processes,and present them by some simple functions of the primitive *** LILs tell us some interesting insights,such as,the LILs of busy and idle times are zero and they reflect a small variability around their fluid approximations,the LIL of departure has nothing to do with the arrival process,both of the two phenomena well explain the service station’s situation of being busy all the *** external system shows us a distinguishing effect on the performance measures:an underloaded(overloaded,critically loaded)external system affects the internal system through its arrival(departure,arrival and departure together).In addition,we also get the strong approximation of the network as an auxiliary result.

关键词： two-station queueing network the law of the iterated logarithm(LIL) strong approximation fluid approximation

Degradation of neonicotinoids with different molecular structures in heterogeneous peroxymonosulfate activation system through different oxidation pathways

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第9期35卷 331-339页

作者： Ruonan guo Heng Zhang Changsheng guo Ningqing Lv Beidou Xi {2. Xu State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

The elimination of neonicotinoids(NEOs)from water has been a research priority due to their threats to human health and *** this study,we established the heterogeneous peroxymonosulfate(PMS)activation system using manganese catalyst(Mn NC)and cobalt catalyst(Co NC)to trigger the nonradical oxidation and synergistic oxidation pathway,respectively to remove *** results showed that the nonradical oxidation system exhibited superior NEOs degradation *** composition of organic pollutants in wastewater significantly impacted subsequent degradation *** charge distribution and reaction sites of various NEOs were analyzed using density functional theory(DFT)calculations,and it demonstrated the electron distribution and activity of NEOs were significantly influenced by the type and number of *** group(–NO_(2.)and cyanide group(–C≡N)were identified as strong electron-withdrawing groups and prone to be attacked by negatively charged *** transformation of NEOs was analyzed,and result showed that the C and N sites adjacent to the nitro group and cyanide group were more susceptible to oxidation attacks.S and N atoms,which possess strong electronegativity and high electron cloud density,were identified as key active sites in the degradation *** outcomes of this study provide valuable guidance for the oriented regulation of oxidation pathways towards efficient removal of NEOs in water.

关键词： Fenton-like processes Molecular structure Neonicotinoids Nonradical oxidation Degradation pathway

Processing of a low-costγ-γ'NiPtAl coating with improved oxidation resistance

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第6期43卷 2832-2841页

作者： Yan jiang Liang-Liang Wei jian He Hong-Bo {2. School of Materials Science and Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structural Materials and Protective Coatings Ministry of Industry and Information TechnologyBeihang UniversityBeijing 100191China

A novelγ-γ'(Ni solid solution—Ni_(3)Al)NiPtAl coating was produced on advanced single-crystal(SC)superalloy N5 by electroplating of a thin Pt coating with~3μm in thickness followed by heat treatment at 1000℃in *** comparison,a traditionalγ-γ'NiPtAl coating was also produced by electroplating of a thick Pt coating with~6μm in thickness followed by heat treatment at 1100℃in *** novel coating has a mass gain of~0.5 mg·cm^(-2.after 100 h 1-h cyclic oxidation at 1150℃,showing better oxidation resistance than the traditional *** oxide scale mostly consisting ofα-Al_(2.O_(3)grew on the novel coating because the element Cr from the SC alloy substrate contributes to the formation ofα-Al_(2.O_(3).Pt content in the novel coating has significant effect on the oxidation *** optimized Pt content in the coating is about 16 at%,which is helpful to reduce the diffusion of harmful elements from the substrate into the coating but also to reduce the cost of the coating.

关键词： γ-γ'NiPtAl coating Platinum Oxidation Al_(2.O_(3) Superalloy

Three-dimensional cell-based strategies for liver regeneration

在线全文

学校读者我要写书评

暂无评论

BIOCELL 2024年第7期48卷 1023-1036页

作者： DAN guo XI XIA jian YANG Liver Transplant Center Transplant CenterWest China HospitalSichuan UniversityChengdu610041China Frontiers Medical Center Tianfu Jincheng LaboratoryChengdu610212China

Liver regeneration and the development of effective therapies for liver failure remain formidable challenges in modern *** recent years,the utilization of 3D cell-based strategies has emerged as a promising approach for addressing these urgent clinical *** review provides a thorough analysis of the application of 3D cell-based approaches to liver regeneration and their potential impact on patients with end-stage liver ***,we discuss various 3D culture models that incorporate hepatocytes and stem cells to restore liver function and ameliorate the consequences of liver ***,we explored the challenges in transitioning these innovative strategies from preclinical studies to clinical *** collective insights presented herein highlight the signiﬁcance of 3D cell-based strategies as a transformative paradigm for liver regeneration and improved patient care.

关键词： Three-Dimensional Liver regeneration Organoids Stem cells Cell therapy

Improving mathematical model of burden distribution and correcting chute angle to cope with fluctuation of stock line

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第2期31卷 342-356页

作者： jian-sheng Chen Wen-guo Liu Hao guo Wang Ding Qing-guo Xue Jing-song Wang Hai-bin Zuo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China MCC Capital Engineering&Research Incorporation Limited Beijing100176China Hunan Valin Xiangtan Iron and Steel Co. Ltd.Xiangtan411101HunanChina

Accurate evaluations of the burden distribution are of critical importance to stabilize the operation of blast *** mathematical model and discrete element method(DEM)are two attractive methods for predicting burden *** on DEM,the initial velocities of the pellet,sinter,and coke were calculated,and the velocity attenuations of the above three particles between the burden and the chute were *** initial velocity and velocity attenuation were applied to a mathematical model for improving the ***,based on the improved model,a scheme for rectifying the chute angles was proposed to address the fluctuation of the stock line and maintain a stable burden *** validity of the scheme was confirmed via a stable burden distribution under different stock *** mathematical model has been successfully applied to evaluate the online burden distribution and cope with the fluctuation of the stock line.

关键词： Burden distribution Mathematical model Discrete element method Velocity attenuation Stock line fluctuation

Overvoltage Calculation Method for Sending System Under DC Fault Disturbance Considering the Influence of Renewable Energy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第5期10卷 1865-1875页

作者： Haoyue Gong jianbo guo Qiang guo jian Zhang Qinyong Zhou Libo Zhang China Electric Power Research Institute Beijing 100192China

Bipolar blocking and commutation failure in the renewable energy transmission system through ultra-high voltage direct current will produce significant temporary *** paper analyzes the physical process of sending end grid overvoltage caused by two types of DC faults and establishes a DC overvoltage model considering renewable energy *** to characteristics of the sending end grid,the influence of the system equivalent impedance,the proportion of renewable energy output,the active and reactive power coefficients of the renewable energy sources during the low voltage ride through process on the overvoltage is analyzed respectively,and the relationship between the proportion of renewable energy output and the short-circuit ratio under the overvoltage constraint is *** validity and practicality of the model and analysis method proposed in this paper are verified by combining the typical transmission system at the sending end of the actual power grid and regional power grid systems.

关键词： Bipolar blocking commutation failure low voltage ride through renewable energy temporary overvoltage

Ultralow-phase-noise and broadband frequency-hopping coupled optoelectronic oscillator under quiet point operation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第8期12卷 1785-1793页

作者： HUI LIU MINGYANG guo TIAN ZHANG jian DAI KUN XU State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Advancements in microwave photonics have yielded novel approaches for generating high-purity microwave *** these,optoelectronic oscillators(OEOs)and coupled optoelectronic oscillators(COEOs)have demonstrated the capability to generate frequency-independent microwaves with exceptionally low phase ***,the tunability of the oscillators is rather limited due to the necessity for narrowband electronic bandpass filters,presenting challenges in achieving both wide and rapid tuning ***,we present a COEO featuring ultralow phase noise,flexible tuning capability,and high *** is achieved through a quiet point(QP)-operated harmonic mode-locked fiber laser,which effectively mitigates optical amplifier noise and supermode competition,thus significantly diminishing the necessity for ultra-narrow electronic *** to the liberated tuning ability,we present an oscillator that can be tuned from 2.GHz to 18 GHz,with phase noise as low as-140 d Bc/Hz at 10 k Hz under the QP *** then illustrate the practical application of the proposed oscillator in generating frequency-hopping signals with consistent spurious modes less than-85 d Bc,absolute phase noise below-135 d Bc/Hz at 10 k Hz,hopping resolution of 1.2. MHz,and fractional frequency stability below 6.1×10^(-12.at 1 s averaging time when locked to a *** presented COEO structure emerges as a compelling solution for agile and low-noise microwave sources in advanced wireless communication and radar systems.

关键词： optoelectronic tuning amplifier

Inverse reliability analysis and design for tunnel face stability considering soil spatial variability

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1552-1564页

作者： Zheming Zhang jian Ji Xiangfeng guo Siang Huat Goh Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China Department of Civil and Environmental Engineering National University of SingaporeSingapore

The traditional deterministic analysis for tunnel face stability neglects the uncertainties of geotechnical parameters,while the simplified reliability analysis which models the potential uncertainties by means of random variables usually fails to account for soil spatial *** overcome these limitations,this study proposes an efficient framework for conducting reliability analysis and reliability-based design(RBD)of tunnel face stability in spatially variable soil *** three-dimensional(3D)rotational failure mechanism of the tunnel face is extended to account for the soil spatial variability,and a probabilistic framework is established by coupling the extended mechanism with the improved Hasofer-Lind-Rackwits-Fiessler recursive algorithm(iHLRF)as well as its inverse analysis *** proposed framework allows for rapid and precise reliability analysis and RBD of tunnel face *** demonstrate the feasibility and efficacy of the proposed framework,an illustrative case of tunnelling in frictional soils is presented,where the soil's cohesion and friction angle are modelled as two anisotropic cross-correlated lognormal random *** results show that the proposed method can accurately estimate the failure probability(or reliability index)regarding the tunnel face stability and can efficiently determine the required supporting pressure for a target reliability index with soil spatial variability being taken into ***,this study reveals the impact of various factors on the support pressure,including coefficient of variation,cross-correlation between cohesion and friction angle,as well as autocorrelation distance of spatially variable soil *** results also demonstrate the feasibility of using the forward and/or inverse first-order reliability method(FORM)in high-dimensional stochastic *** is hoped that this study may provide a practical and reliable framework for determining the stability of tunnels in complex

关键词： Limit analysis Tunnel face stability Spatial variability HLRF algorithm Inverse reliability method