检索结果-南通市图书馆

Control Theory and Technology 2024年第3期22卷 455-467页

作者： r.h.harsha Nawarathna yuandan Lin yuan Wang Department of Mathematical Sciences Florida Atlantic UniversityBoca RatonFL 33431USA

We consider how small delays affect the integral-input-to-state stability(iss)property for a *** result is similar to the input-to-state stability(Iss)result obtained in[1]:the iss property will be preserved in a practical and semi-global manner if the delay interval is small ***,since the iss quantifies the robust stability in terms of a generalized Li norm of the inputs instead of a generalized Loo norm of the inputs for the Iss case,the techniques and proofs for the Iss case do not apply to the iss case *** the proofs in[1]are based on the Lyapunov-razumikhin approach,our proofs are based on the iss-Lyapunov functions for the zero-delay *** addition to the interest by its own in showing how the iss property is affected by small delays,the result also serves to the study of the iss property for singularly perturbed systems.

关键词： Integral-input-to-state stability Nonlinear systems Small delays Lyapunov method

robustness of the octupole collectivity in 144Ba within the cranking covariant density functional theory in 3D lattice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第8期35卷 124-131页

作者： Ze‑Kai Li yuan‑yuan Wang Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China hebei Key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000China

The octupole deformation and collectivity in octupole double-magic nucleus 144Ba are investigated using the Cranking covariant density functional theory in a three-dimensional lattice *** reduced B(E3)transition probability is implemented for the first time in semiclassical approximation based on the microscopically calculated electric octupole *** available data,including the I-ωrelation and electric transitional probabilities B(E2)and B(E3)are well ***,it is shown that the ground state of 144Ba exhibits axial octupole and quadrupole deformations that persist up to high spins(I≈24h).

关键词： Octupole collectivity Cranking covariant density functional theory rotational spectrum Electric transitional probabilities

Single-pilot operations in commercial flight:Effects on neural activity and visual behaviour under abnormalities and emergencies

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第8期37卷 277-292页

作者： Qinbiao LI Chun-hsien ChEN Kam K.h.NG Xin yuan Cho Yin YIU human Factors and Ergonomics Laboratory Department of Aeronautical and Aviation EngineeringThe Hong Kong Polytechnic UniversityHong Kong Special Administrative Region 100872China School of Mechanical&Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

With cutting-edge technologies and considering airline human-resource-saving,a single pilot in commercial jets could be technically *** changes in captains’natural behaviours are initially required to comprehend the specific safe human performance envelope for safeguarding single-pilot flight,particularly in high-risk *** paper investigates how captains’performance transforms for fixing emergencies when operating from Dual-Pilot Operations(DPO)to Single-Pilot Operations(SPO)through a physiological-based *** pilots flew an emergency-included flight with/without first officers’*** neural activities and scanning behaviours were recorded using a 32-channel Electroencephalogram(EEG)and glasses-based eye tracker,with the observation and post-experiment questionnaires to evaluate the flight operations and pilots’*** alone,there was a significantly increased cortical activity in h and b waves over the frontal,parietal,and temporal lobes during the more complicated emergencies,and pilots focused less on the primary flight display while spending significantly more time scanning the other *** physiological fluctuating patterns associated with risky operations in SPO were highlighted by cross-correlating multimodal *** experimental-based noteworthy insights may wish to inform commercial SPO measures to lessen the persistent physiological fluctuation,assisting airlines in creating SPO-oriented intelligent flight systems to give captains adequate support for assuring safer air transportation.

关键词： Aviation engineering Single pilot operations Behaviour changes Eye tracker Electroencephalogram

hydrogen-rich surface of MoC catalysts for efficient CO_(2) hydrogenation induced by a coupled hydrogen donator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano research 2024年第8期17卷 7762-7767页

作者： Dong Xu Si-yuan Xia Qi-yuan Li Jie-Sheng Chen Xin-hao Li School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240China

Direct CO_(2) hydrogenation offers an important strategy for promoting the global carbon balance,but high thermodynamic and kinetic stability of CO_(2) has restricted its applicability to only a handful of industrial ***,we introduce a proof-of-concept application of the electron-rich Pt surface to promote hydrogen donation for electron-rich MoC particles acting as hydrogen acceptors,thereby constructing hydrogen-rich surface of MoC active ***,the formed hydrogen-rich and electronrich surface could greatly decrease reaction activation energy to boost the efficient CO_(2) hydrogenation into formic acid over the MoC *** optimized MoC@NC/Pt-0.1(NC:nitrogen-doped carbon)catalyst exhibits a high turnover frequency(TOF)value of 1.2 h^(−1) at a lower temperature of 60℃and a TOF of 24.2 h^(−1) under standard reaction conditions widely used in the literature,exceeding 7 times of MoC@NC catalyst and surpassing the benchmark classical non-noble metal active center-based heterogeneous catalyst.

关键词： electron-rich Pt nanoparticles hydrogen donation hydrogen-rich MoC nanoparticles CO_(2) hydrogenation formic acid

A Stable Copper-based Metal-Azolate Framework for Efficient Electroreduction of CO_(2)to C_(2+)Products

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical research in Chinese Universities 2024年第4期40卷 664-669页

作者： LIU yuan-yuan ZhU hao-Lin LIAO Pei-Qin ChEN Xiao-Ming Key Laboratory of Bioinorganic and Synthetic Chemistry Ministry of EducationGBRCE for Functional Molecular EngineeringSchool of ChemistryIGCMESun Yat-sen UniversityGuangzhou510275P.R.China Chemistry and Chemical Engineering Guangdong Laboratory Shantou515031P.R.China

Driven by renewable or excess electrical energy,electrochemical CO_(2)reduction reaction(eCO_(2)rr)represents a promising carbon-neutral approach to generating valuable low-carbon fuels by consuming CO_(2)and h_(2)O.C_(2+)products are one of the most economically valuable products among the reduction species of eCO_(2)rr,but there are still some challenges,such as low selectivity or low current *** this work,we showed that a copper-based metal-azolate framework(MAF),denoted as MAF-203,exhibits the high performance of eCO_(2)rr to yield C_(2+)products with the Faradaic efficiency(C_(2+))of 52.5%and a current density of 660 mA/cm^(2)at-1.2 V *** in a flow cell device under alkaline *** experiment,in situ infrared spectroscopy and the density functional theory(DFT)calculations showed that the electron donating effect of methyl substituents on organic ligands of the copper-based MAF could enhance the ligand field and activation of key intermediates(*CO and*ChO species),thus promoting the coupling of*CO and*ChO for yielding C_(2+)products.

关键词： Metal-organic framework Carbon dioxide Electroreduction C_(2+)product Metal-azolate framework

Net effect of air pollution controls on health risk in the Beijing-Tianjin-hebei region during the 2022 winter Olympics and Paralympics

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 Environmental Sciences 2024年第1期135卷 560-569页

作者： Changqing Lin Peter K.K.Louie Alexis K.h.Lau Jimmy C.h.Fung Zibing yuan Minghui Tao Xuguo Zhang Md.Shakhaoat hossain Chengcai Li Xiang Qian Lao Division of Environment and Sustainability The Hong Kong University of Science and TechnologyHong KongChina Environmental Protection Department Hong Kong Government SARHong KongChina Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina Guangdong-hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality The Hong Kong University of Science and TechnologyHong KongChina Department of Mathematics The Hong Kong University of Science and TechnologyHong KongChina School of Environment and Energy South China University of TechnologyGuangzhou 510006China hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China Department of Public health and Informatics Jahangirnagar UniversityDhaka 1342Bangladesh Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Jockey Club School of Public health and Primary Care The Chinese University of Hong KongHong KongChina

Due to the non-linearity in ozone(O_(3))formation,reducing the emission of nitrogen oxides(NO_(x))may increase O_(3) *** the counteractive O_(3) response to NO_(x) reduction,overall impact of air pollution controls can be ambiguous when the assessments focus on the changes in pollutant *** this study,a risk-based method was used to gauge the net effect of air pollution controls on mortality risk in the Beijing–Tianjin–hebei(BTh)region during the 2022 Winter Olympics and Paralympics(WOP).This mega-event presents a unique opportunity to investigate the efficacy of deep cuts in pollutant *** show that O_(3) concentrations greatly increased as nitrogen dioxide(NO_(2))concentrations decreased in the *** to the active photochemical formations,O_(3) became the dominant pollutant that affected human health during the *** the substantial O_(3) increases,the health benefits of NO_(2) reductions overwhelmed the adverse health effects of O_(3) increases in most regions of the BTh(at 81 out of 112 stations).After considering the impacts of particulate matter,the integrated health risk of air pollution mixtures declined almost everywhere in the *** results underscore the great necessity of changing the assessment paradigm of pollution control from using concentration-based methods to using risk-based *** with the carbon neutrality policy,stringent control of NO_(x)emission from combustion sources is a promising way to achieve synergistic control solutions for air pollution and climate change.

关键词： Ozone Nitrogen dioxide health risk Carbon neutrality Mega-events

Synthesis of multifunctional additives for solid propellants:Structure,properties and mechanism

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 308-316页

作者： Pingan Zhang Lina Sun Jianmin yuan Jianru Deng College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082PR China College of Material Science and Engineering Hunan UniversityChangsha 410082PR China hu Bei Sanjiang Aerospace Jianghe Chemical Technology Co. LtdYichang 444200PR China

To simplify the composite propellant formulation and address the current issue of the single-functionality present in existing additives,the multi-cyano,amine-based polybutadiene(AEhTPB-CN)was prepared based on AEhTPB by adopting appropriate synthesis *** replacing 10% of hTPB binder in the propellant formulation,it can effectively enhance the interfacial bond strength between the propellant binder matrix and solid fillers(AP(ammonium perchlorate)and rDX(cyclotrimethylene-trinitramine)),the mechanical properties of the hTPB/AP/rDX/Al propellant were superior to blank control propellant with an improvement of 35.4% in tensile strength,62.0% enhancement in elongation at break,and reduce the propellant burn rate by 10.7% with any energy *** function mechanism of AEhTPB-CN was systematically elucidated through experiments and computer simulation *** results show that the tertiary amine group in AEhTPB-CN can react with AP to form ammonium ionic bonds,and the hydroxyl and cyano groups can form hydrogen bonding interactions with AP,which enables AEhTPB-CN to be firmly adsorbed on the AP surface through chemical and physical *** rDX,the interfacial bonding effect of AEhTPB-CN is attributed to their ability to form C-h···N≡C weak hydrogen bonding interaction between the cyano group and rDX methylene group.

关键词： hydroxyl-terminated polybutadiene(hTPB) hTPB propellant Chemical modification Bonding agent Mechanism

Interface structure of α-Mg/14h-LPSO:First-principles prediction and experimental study

在线全文

学校读者我要写书评

暂无评论

Journal of rare Earths 2024年第9期42卷 1792-1799,I0006页

作者： yuan Shi Xiaohua Zhang hongyan Yue Chao Li School of Materials Science and Chemical Engineering Harbin University of Science and TechnologyHarbin150040China

The interfacial structure of the α-Mg/14h-LPSO phase in rare earth-including magnesium alloy was investigated via high-angle annular dark-field scanning transmission electron microscopy(hAADFSTEM) imaging and first-principles calculations of density-functional *** possible interfacial models were constructed according to the different terminations of the LPSO phase,and the corresponding interfacial energies were calculated,from which the four most stable structures(Terl-MgY-hollow,Ter2-Zn-hollow,Ter3-MgYII-hollow and Ter4-Mg-bridge) were *** interfacial phase diagrams related to the Y chemical potentials were obtained from the calculations,and the most stable interfacial structure was ***-MgY-hollow and Ter2-Zn-hollow have the lowest interfacial energies in the range of-0.7 eV here fluctuating change of state is the minimized and the interface is the most *** separation work of the two models was calculated to predict the bonding strength of the structures at both ends of the *** calculation results show that the maximum interfacial separation work is 1.45 J/m^(2) for the interface model of α-Mg and 14h-LPSO phase structure with Ter2-Zn-hollow termination.

关键词： rare earths Magnesium alloy hAADF-STEM LPSO First-principles Interface

Current status of early gastric cancer screening research

在线全文

学校读者我要写书评

暂无评论

Cancer Biology & Medicine 2024年第3期21卷 218-222页

作者： Can hu Li yuan Xiangdong Cheng Department of Gastric surgery Zhejiang Cancer HospitalHangzhou Institute of Medicine(HIM)Chinese Academy of SciencesHangzhouZhejiang 310022China Key Laboratory of Prevention Diagnosis and Therapy of Upper Gastrointestinal Cancer of Zhejiang ProvinceHangzhou 310022China Zhejiang Provincial research Center for Upper Gastrointestinal Tract Cancer Zhejiang Cancer HospitalHangzhou 310022China

Gastric cancer is a predominant threat to the health and well-being of China's residents. Data from the World health Organization(WhO) in 2020 revealed that gastric cancer in China notably accounted for 44.0% of new c... 详细信息

关键词： cancer Gastric gastric

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted Ph13-8Mo stainless 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4期31卷 945-955页

作者： yuan Zhang Xiang Liu Chang-jun Wang Chang Liu School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel research Institute Co. Ltd.Beijing 100081China

Ph13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of Ph13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,Ph13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： high-strength stainless steel-Selective laser melting-heat treatment Microstructure Mechanical property