检索结果-南通市图书馆

Molecular dynamics study of hydrogen-induced cracking behavior of ferrite–pearlite gas transmission pipeline steel

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2期31卷 488-500页

作者： tao-long Xu Si-han Guo Gong-zhen He Hao-yu han Petroleum Engineering School Southwest Petroleum UniversityChengdu610500SichuanChina Sichuan East Gas Transmission Sales Center of Sinopec Natural Gas Branch Wuhan430074HubeiChina

Hydrogen embrittlement of pipelines depends on the hydrogen-induced cracking behavior of the pipeline steel *** on molecular dynamics analysis,the ferrite–cementite(α-Fe/Fe3C)lamellar atomic structure with the Bagaryatskii orientation relationship was established,and stepwise relaxation of the conjugate gradient energy minimization and constant-temperature and constant-pressure relaxation were performed under NPT(the isothermal–isobaric)*** mechanical property curves of theα-Fe/Fe3C models were obtained under different cementite terminal plane structures,and the evolution of the atomic structure was analyzed in *** addition,the influence of different hydrogen concentrations,different temperatures,different strain rates,changes in voids,and different micro-degrees of freedom on the deformation and failure mechanism of the model was investigated,aiming to provide a reliable way to explore the micro-mechanism of macro-cracking behavior of pipeline steel.

关键词： Ferrite-cementite lamellar structure Pipeline steel Failure mechanism Crack propagation Molecular dynamics

Carbon efficiency modeling and optimization of solar-powered cellular networks

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(Information Sciences) 2024年第5期67卷 228-243页

作者： Yuxi ZHAO Xiaohu GE Wen YAN tao han Yi ZHONG School of Electronic Information and Communications Huazhong University of Science and Technology Huawei Technology Co. Ltd.

As wireless communication traffic experiences rapid growth, the carbon emissions caused by the communication industry are also on the rise. To achieve “carbon neutrality”, researchers are considering the use of renewable energy sources to power cellular networks, thereby reducing carbon emissions. However, a challenge arises when using renewable energy, specifically owing to the unpredictable nature of both the energy consumption of the cellular network and the power generation from renewable sources. This inconsistency results in low renewable energy utilization and reduced carbon efficiency. Herein, we construct a carbon efficiency model of solar-powered cellular networks using practical data from solar radiation. We propose a mechanism that alternately optimizes the performance of the renewable energy network and the cellular network. This approach is based on convex optimization theory and the Dinkelback algorithm, and it leads to the design of a carbon efficiency optimization algorithm. This algorithm aims to improve the carbon efficiency of cellular networks and reduce their carbon emissions. Simulation results demonstrate that our optimization scheme yields a maximum improvement of 2.56 × 108bps/g in the carbon efficiency of the cellular network as compared to conventional power allocation schemes such as the traditional water filling method and heuristic energy sharing and charge/discharge algorithms.

关键词： cellular networks renewable energy carbon efficiency convex optimization theory dinkelbach

Feasibility of medical radioisotope production based on the proton beams at China Spallation Neutron Source

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第6期35卷 26-39页

作者： Bing Jiang Bin-Bin Tian han-tao Jing Qi-Fan Dong Spallation Neutron Source Science Center Dongguan 523803China Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China University of Chinese Academy of Sciences Beijing 100049China

The utilization of a proton beam from the China Spallation Neutron Source(CSNS)for producing medical radioisotopes is appealing owing to its high current intensity and high *** medical isotope production based on the proton beam at the CSNS is significant for the development of future radiopharmaceuticals,particularly for theα-emitting *** production yield and activity of typical medical isotopes were estimated using the FLUKA *** results indicate that the 300-MeV proton beam with a power of 100 kW at CSNS-II is highly suitable for proof-of-principle studies of most medical *** particular,this proton beam offers tremendous advantages for the large-scale production of alpha radioisotopes,such as 225Ac,whose theoretical production yield can reach approximately 57 Ci/*** on these results,we provide perspectives on the use of CSNS proton beams to produce radioisotopes for medical applications.

关键词： CSNS proton beam Medical isotope production α-Emitting radionuclides Nuclidic purity analysis

Influence of Repetitive Impulse Waveforms on Surface Discharge Characteristics and Insulation Life for Polyimide Film

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 746-755页

作者： Zhiyun han Qingmin Li Yujin Guo tao Liu Guojing Dong hanwen Ren State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China Electric Power Research Institute Beijing 100085China Inner Mongolia Electric Economy and Technology Academy Hohhot 010020China

Accelerated insulation aging problems under high frequency repetitive impulses in power electronic transformers are drawing more and more attention in modern power systems. Partial discharge (PD) characteristics including discharge inception voltage, phase distribution and statistical characteristics on polyimide (PI) surface under different impulse waveforms and the insulation life of PI films are studied in this paper. We carry out experiments based on PD and insulation lifetime test systems, using five different types of repetitive impulses, including three bipolar waves and two unipolar waves. The experimental results show that there is little variation in discharge inception voltage under different waveforms, but great variation in phase distribution and statistical characteristics of PD. In addition, insulation life is approximately the same under different waveforms with the same polarity, and the aging rate under bipolar waveforms is larger than that under unipolar waveforms. We explain the differences between the bipolar and unipolar waveforms on insulation life, which can be concluded that the surface charge under unipolar waveform accumulates more significnatly compared with bipolar waveform and decreases the electric filed strength in discharging the air gap and inhibits surface discharge from occurring.

关键词： Insulation life polyimide film power electronic transformer repetitive impulse surface discharge characteristics

Interpretable data-driven fault diagnosis method for data centers with composite air conditioning system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2024年第6期17卷 965-981页

作者： Yiqi Zhang Fumin tao Baoqi Qiu Xiuming Li Yixing Chen Zongwei han SEP Key Laboratory of Eco-Industry School of MetallurgyNortheastern UniversityShenyang110819China Energy Saving and Low-carbon Technology of Process Industry Engineering Research Center of Liaoning Province Northeastern UniversityShenyang110819China College of Civil Engineering Hunan UniversityChangsha410082China

Fault detection and diagnosis are essential to the air conditioning system of the data center for elevating reliability and reducing energy *** study proposed a convolutional neural network(CNN)based data-driven fault detection and diagnosis model considering temporal dependency for composite air conditioning system that is capable of cooling the high heat flux in data *** input of fault detection and diagnosis model was an unsteady dataset generated by the experimentally validated transient mathematical *** dataset concerned three typical faults,including refrigerant leakage,evaporator fan breakdown,and condenser ***,the CNN model was trained to construct a map between the input and system operating ***,the performance of the CNN model was validated by comparing it with the support vector machine and the neural ***,the score-weighted class mapping activation method was utilized to interpret model diagnosis mechanisms and to identify key input features in various operating *** results demonstrated in the pump-driven heat pipe mode,the accuracy of the CNN model was 99.14%,increasing by around 8.5%compared with the other two *** the vapor compression mode,the accuracy of the CNN model achieved 99.9%and declined the miss rate of refrigerant leakage by at least 61%*** score-weighted class mapping activation results indicated the ambient temperature and the actuator-related parameters,such as compressor frequency in vapor compression mode and condenser fan frequency in pump-driven heat pipe mode,were essential features in system fault detection and diagnosis.

关键词： data center composite air conditioning system fault detection and diagnosis interpretable artificial intelligence

Accelerated aging and frailty in cardiovascular diseases

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 Geriatric Cardiology 2024年第8期21卷 828-830页

作者： Xue-Hua CHENG tao WU Li han Department of Traditional Chinese Medicine Geriatrics Huadong Hospital Affiliated to Fudan UniversityShanghaiChina

Aging is the greatest risk factor for cardiovascular disease(CVD),which is the most common cause of death in European countries.[1]It is estimated that during the period from 2020 to 2022,there were 9.0%more excess deaths from CVD than expected.[2]By 2030,approximately 20%of the population will be aged 65 years and older,and CVD will account for 40%of deaths in this age group,[3]imposing a significant burden on the healthcare system and society as a *** is related to frailty,which represents the dynamic progression of physical and physiological decline in older *** limits an individual’s ability to recover from acute stressors and serves as a predictor of clinical adverse *** the uncertainties in screening,assessing,and managing frailty in clinical practice,emphasizing the connections between frailty,aging,and CVD will provide new insights for the prediction,prevention and management of CVD in the aging population.

关键词： aging prevention prediction

Sampling-efficient path planning and improved actor-critic-based obstacle avoidance for autonomous robots

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第5期67卷 197-214页

作者： Yefeng YANG tao HUANG Tianqi WANG Wenyu YANG han CHEN Boyang LI Chih-yung WEN Department of Aeronautical and Aviation Engineering The Hong Kong Polytechnic University Center for Control Theory and Guidance Technology Harbin Institute of Technology School of Engineering The University of Newcastle Research Center for Unmanned Autonomous Systems The Hong Kong Polytechnic University

Autonomous robots have garnered extensive utilization in diverse fields. Among the critical concerns for autonomous systems, path planning holds paramount importance. Notwithstanding considerable efforts in its development over the years, path planning for autonomous systems continues to grapple with challenges related to low planning efficiency and inadequate obstacle avoidance response in a timely *** study proposes a novel and systematic solution to the path planning problem within intricate office buildings. The solution consists of a global planner and a local planner. To handle the global planning aspect, an adaptive clustering-based dynamic programming rapidly exploring random tree(ACDP-RRT) algorithm is proposed. ACDP-RRT effectively identifies obstacles on the map by leveraging geometric *** obstacles are then represented as a collection of sequentially arranged convex polygons, optimizing the sampling region and significantly enhancing sampling efficiency. For local planning, a network decoupling actor-critic(ND-AC) algorithm is employed. The proposed ND-AC simplifies the local planner design process by integrating planning and control loops into a neural network(NN) trained via an end-to-end model-free deep reinforcement learning(DRL) framework. Moreover, the adoption of network decoupling(ND) techniques leads to an improved obstacle avoidance success rate when compared to conventional actor-critic(AC)-based methods. Extensive simulations and experiments are conducted to demonstrate the effectiveness and robustness of the proposed approach.

关键词： rapidly exploring random tree (RRT) adaptive clustering network decoupling actor critic (AC) path planning

Comparison of cytokine levels in prostatic secretion between the Ⅲa and Ⅲb subtypes of prostatitis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2024年第1期26卷 77-84页

作者： Cheng-Lin han Yu-Xuan Deng Peng Hu Bin-tao Hu tao Wang Ji-Hong Liu Ming-Chao Li Department of Urology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430000China

Chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS),also known as National Institutes of Health(NIH)type Ⅲ prostatitis,is a common disorder with an unclear etiology and no known curative *** on the presence or absence of leukocytes in expressed prostatic secretion(EPS),CP/CPPS is classifiedfurther into Illa(inflammatory)and Illb(noninflammatory)***,the severity of symptoms is not entirely consistent with the white blood cell(WBC)*** the preliminary finding of a link between inflammatory cytokines and CP/CPPS,we performed this clinical study with the aim of identifying cytokines that are differentially expressed according to whether the prostatitis subtype is Ⅲa or Ⅲ*** found that granulocyte colony-stimulating factor(G-CSF),interleukin-18(IL-18),and monocyte chemoattractant protein-1(MCP-1)levels were significantly elevated and interferon-inducible protein-10(IP-10)and platelet-derived growth factor-BB(PDGF-BB)levels were downregulated in the EPS of patients with type Ⅲa *** a word,it is a meaningful study in which we investigate the levels of various cytokines in EPS according to whether prostatitis is the Ⅲa or Ⅲb *** combination of G-CSF,IL-18,MCP-1,IP-10,and PDGF-BB expression levels could form a basis for classification,diagnosis,and therapeutic targets in clinical P/CPPS.

关键词： chronic prostatitis/chronic pelvic pain syndrome(CP/CPPS) cytokines NIH-Ⅲa NIH-ⅢB

Prospects for weighing neutrinos in interacting dark energy models using joint observations of gravitational waves andγ-ray bursts

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 C 2024年第9期48卷 225-233页

作者： Lu Feng tao han Jing-Fei Zhang Xin Zhang College of Physical Science and Technology Shenyang Normal UniversityShenyang 110034China Key Laboratory of Cosmology and Astrophysics(Liaoning Province)&Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

Cosmological observations can be used to weigh neutrinos,but this method is model-dependent,with results relying on the cosmological model *** we consider interactions between dark energy and dark matter,the neutrino mass constraints differ from those derived under the standard *** the contrary,gravitational wave(GW)standard siren observations can measure absolute cosmological distances,helping to break parameter degeneracies inherent in traditional cosmological observations,thereby improving constraints on neutrino *** paper examines the constraints on neutrino mass within interacting dark energy(IDE)models and explores how future GW standard siren observations could enhance these *** multi-messenger GW observations,we consider the joint observations of binary neutron star mergers by third-generation ground-based GW detectors and shortγ-ray burst observations by missions similar to the THESEUS satellite *** current cosmological observations(CMB+BAO+SN),we obtain an upper limit on the neutrino mass in the IDE models of 0.15(or 0.16)*** the inclusion of GW data,the upper limit on the neutrino mass improves to 0.14 *** indicates that in the context of IDE models,the improvement in neutrino mass constraints from GW observations is relatively ***,GW observations significantly enhance the constraints on other cosmological parameters,such as matter density parameter,the Hubble constant,and coupling strength between dark energy and dark matter.

关键词： interacting dark energy neutrino mass gravitational wave standard siren cosmology