检索结果-南通市图书馆

China Communications 2022年第10期19卷 38-54页

作者： Luguang Wang fei song Gui Fang Zhibin Feng Wen Li Yifan Xu Chen Pan Xiaojing Chu College of Communications Engineering Army Engineering University of PLANanjing 210000China

In multi-agent confrontation scenarios, a jammer is constrained by the single limited performance and inefficiency of practical application. To cope with these issues, this paper aims to investigate the multi-agent jamming problem in a multi-user scenario, where the coordination between the jammers is considered. Firstly, a multi-agent Markov decision process (MDP) framework is used to model and analyze the multi-agent jamming problem. Secondly, a collaborative multi-agent jamming algorithm (CMJA) based on reinforcement learning is proposed. Finally, an actual intelligent jamming system is designed and built based on software-defined radio (SDR) platform for simulation and platform verification. The simulation and platform verification results show that the proposed CMJA algorithm outperforms the independent Q-learning method and provides a better jamming effect.

关键词： multi-agent reinforcement learning intelligent jamming collaborative jamming software-defined radio platform

Effect of biometric characteristics on biomechanical properties of the cornea in cataract patient

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2016年第6期9卷 854-857页

作者： Xue-fei song Achim Langenbucher Zisis Gatzioufas Berthold Seitz Moatasem El-Husseiny Department of Ophthalmology Saarland University Medical Center Department of Ophthalmology Ninth People's HospitalShanghai Jiao Tong UniversitySchool of Medicine Experimental Ophthalmology Saarland University

AIM： To determine the impact of biometric characteristics on the biomechanical properties of the human cornea using the ocular response analyzer （ORA） and standard comprehensive ophthalmic examinations before and after standard phacoemulsificaUon. METHODS： This study comprised 54 eyes with cataract with significant lens opacification in stages I or II that underwent phacoemulsification （2.8 mm incision）. Corneal hysteresis （CH）, corneal resistance factor （CRF）, Goldmann-correlated intraocular pressure （IOPg）, and corneal-compensated intraocular pressure （IOPcc） were measured by ORA preoperatively and at lmo postoperatively. Biometric characteristics were derived from corneal topography [TMS-5, anterior equivalent （EQTMS） and cylindric （CYLTMS） power], corneal tomography [Casia, anterior and posterior equivalent （EQaCASC, EQpCASIA） and cylindric （CYLaCASIA, CYLpCASIA） power], keratometry [IOLMaster, anterior equivalent （EQIOL） and cylindric （CYL,oL） power] and autorefractor [anterior equivalent （EQAR）]. Results from ORA were analyzed and correlated with those from all other examinations taken at the same time point. RESULTS： Preoperatively, CH correlated with EQpCASIA and CYLpCASIA only （P=0.001, P=0.002）. Postoperatively, IOPg and IOPcc correlated with all equivalent powers （EQTMS, EQIOL, EQAR, EQaCASIA, and EQpCASIA）（P=0.001, P=0.007, P=0.001, P= 0.015, P=0.03 for IOPg and P〈0.001, ,0=0.003, P〈0.001, P= 0.009, P=0.014 for IOPcc）. CH correlated postoperatively with EQaCASIA and EQpCASIA only （P=0.021, P=0.022）. CONCLUSION： Biometric characteristics may significantly affect biomechanical properties of the cornea in terms of CH, IOPcc and IOPg before, but even more after cataract surgery.

关键词： cataract surgery biometric characteristics biomechanical properties ocular response analyzer cornealtomography correlation analysis

Investigation on synergistic deposition of wax and hydrates in waxy water-in-oil(W/O) flow systems

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

Petroleum Science 2022年第4期19卷 1840-1852页

作者： Yang Liu Xiao-Fang Lv Qian-Li Ma Shi-Dong Zhou Bo-Hui Shi Hui Du Yun Lei Peng-fei Yu Shang-fei song Jing Gong Bing-Cai Sun Jiangsu Key Laboratory of Oil and Gas Storage and Transportation Technology Changzhou UniversityChangzhouJiangsu213164China Institute of Petroleum Engineering Technology Sinopec Northwest Oil Field CompanyUrumqiXinjiang830011China National Engineering Laboratory for Pipeline Safety/State Key Laboratory of Natural Gas Hydrate China University of Petroleum-BeijingBeijing102249China CNPC Safety and Environmental Protection Technology Research Institute Co.Ltd Beijing102206China

Elucidating the synergistic effect of wax and hydrates, involving formation, aggregation and deposition,is imperative to the operation and transportation safety for offshore petroleum fields. To understand the characteristics and mechanism of synergistic deposition of wax and hydrates, flow and deposition experiments of systems with different wax contents(0-2.89 wt%), initial flow rates, pressures and temperatures were conducted in a high pressure visual flow loop. According to the flow rate and pressure drop data as well as the visual window observation, four different types of plugging scenarios of waxhydrate coexisting systems with different flow properties and wall deposition state were summarized,including rapid plugging, transition plugging, gradual plugging type I and gradual plugging type *** with the wax-free system after hydrate formation, even with the addition of anti-agglomerant(AA) with the same concentration, wax-hydrate coexisting systems could not reach stable hydrate slurry flow state, indicating that the existence of wax deteriorated the performance of AA. Aside from the influence of wax crystals on hydrate agglomeration, it was found that wax deposition layer would alter the adhesion and bedding of hydrates, resulting in the variation of flow properties and wall deposition *** low wax content systems(0.75 wt%) where rapid plugging occurred, the synergistic effect between wax and hydrates promoted the formation of wax-hydrate coupling aggregates, resulting in severe local deposition when the coupling aggregates attained critical deposition size and consequently decreasing flow rate, forming a vicious circle of decreasing transportability. Since bedding of coupling aggregates was hindered by the uniformly coated wax deposition layer on pipe wall, gradual plugging rather than rapid plugging occurred in medium wax content systems(1-1.25 wt%), predominately caused by the gradual increment in viscosity of waxy hydrate slurry. For relative

关键词： Flow assurance Wax Hydrates Flow properties Synergistic deposition

THE EVENTUALLY DISTANCE MINIMIZING RAYS IN MODULI SPACES

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2018年第3期38卷 950-964页

作者： fei song Yi QI Guangming HU LMIB School of Mathematics and Systems Science Beihang University LMIB School of Mathematics and Systems Science Beihang University

The eventually distance minimizing ray（EDM ray） in moduli spaces of the Riemann surfaces of analytic finite type with 3 g ＋ n-3 〉 0 is studied, which was introduced by Farb and Masur [5]. The asymptotic distance of EDM rays in a moduli space and the distance of end points of EDM rays in the boundary of the moduli space in the augmented moduli space are discussed in this article. A relation between the asymptotic distance of EDM rays and the distance of their end points is established. It is proved also that the distance of end points of two EDM rays is equal to that of end points of two Strebel rays in the Teichmu¨ller space of a covering Riemann surface which are leftings of some representatives of the EDM rays. Meanwhile, simpler proofs for some known results are given.

关键词： Augmented Teichmüller space augmented moduli space Strebel differential EDM ray

Covalently tethering disulfonic acid moieties onto polyoxometalate boosts acid strength and catalytic performance for hydroxyalkylation/alkylation reaction

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2022年第4期65卷 699-709页

作者： Lifei Lian Yubing Liu Xianfeng Yi Hanbin Hu Xiang Chen Hongqiang Li Wei Chen Anming Zheng Yu-fei song State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China Wuhan Center for Magnetic Resonance Key Laboratory of Magnetic Resonance in Biological SystemsState Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsWuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China

Solid acid catalysts are widely used in the production of various high-value added and industrially important *** the use of organosilicon compounds to modify the vacancy site has been extensively studied,the covalent tethering-SO_(3)H functionalized organosilicon modified polyoxometalates(POMs)has been rarely *** this work,two catalysts(TBA_(4)[SiW_(11)O_(39)(O(SiC_(3)H_(6)SO_(3)H)_(2))](compound 2)and TBA_(4)[SiW_(11)O_(39)(O(SiC_(8)H_(8)SO_(3)H)_(2))](compound 3))were synthesized successfully through covalently grafting different sulfonic acid(-SO_(3)H)groups onto[SiW_(11)O_(39)]^(8−)cluster,*** 2 was achieved by surface grafting and in situ oxidation(3-mercaptopropyl)-trimethoxysilane,while compound 3 was achieved by surface grafting of 2-(4-chlorosulfonylphenyl)*** Brønsted acid strength of compounds 2 and 3 can be demonstrated by different methods including potentiometric titration,pyridine adsorption studies,and the ^(31)P trimethylphosphine oxides(TMPO)nuclear magnetic resonance(NMR).The systematic investigation of the relationship among POM structures,acid strength,and electron density was carried out based on density functional theory(DFT)calculation and experimental results,which revealed that covalent modification of compounds 2 and 3 decreased the electron density of the O-H bond,and promoted the release of H^(+).When applied in hydroxyalkylation/alkylation(HAA)reaction of 2-methylfuran(2-MF)with cyclohexanone,compound 2 exhibited better catalytic performance with conversion of ~93%,monocyclic fuel precursors(1a)yield of 79.9% and selectivity of 85.7% than compound 3,which can be attributed to strong Brønsted acid and the intramolecular hydrogen-bonding interactions between the neighboring -SO_(3)H moieties in compound ***,compound 2 also showed excellent catalytic activity in the HAA reaction of 2-MF with several different aldehydes and ketones(e.g.,furfuraldehyde,5-methylfurfurald

关键词： polyoxometalates sulfonic acid covalent modifications acid catalysis alkylation reaction

Molecular surface functionalization of In_(2)O_(3) to tune interfacial microenvironment for enhanced catalytic performance of CO_(2) electroreduction

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1242-1250页

作者： Suwen WangQiang GaoCui Xu Shuai Jiang Mengyang Zhang Xianjun Yin Hui-Qing Peng Bin Liu Yu-fei song State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringCollege of ChemistryBeijing University of Chemical TechnologyBeijing 100029China

Indium-based materials(e.g.,In_(2)O_(3))are a class of promising non-noble metal-based catalysts for electroreduction of carbon dioxide(CO_(2)).However,competitive hydrogen reduction reaction(HER)on indium-based catalysts hampers CO_(2) reduction reaction(CO_(2)RR)*** herein tune the interfacial microenvironment of In_(2)O_(3) through chemical graft of alkyl phosphoric acid molecules using a facile solution-processed strategy for the first time,which is distinguished from other researches that tailor intrinsic activity of In_(2)O_(3) *** surface functionalization of alkyl phosphoric acids over In_(2)O_(3) is demonstrated to remarkably boost CO_(2) *** example,octadecylphosphonic acid modified In_(2)O_(3) exhibits Faraday efficiency for H_(2) H_(2) H_(2)(FE)of as low as 6.6%and FEHCOOH of 86.5%at-0.67 V ***,which are far superior to parent In_(2)O_(3) counterparts(FE of 24.0%and FEHCOOH of 63.1%).Moreover,the enhancing effect of alkyl phosphoric acid functionalization is found to be closely related to the length of alkyl *** virtue of comprehensive experimental characterizations and molecular dynamics simulations,it is revealed that the modification of alkyl phosphoric acids significantly alters the interface microenvironment of the electrocatalyst,which changes the electrocatalyst surface from hydrophilic and aerophobic to hydrophobic and *** this case,the water molecules are pushed away and more CO_(2) molecules are trapped,increasing local CO_(2) concentration at In_(2)O_(3) active sites,thus leading to the significantly enhanced CO_(2)RR and suppressed *** work highlights the importance of regulating the interfacial microenvironment of inorganic catalysts by molecular surface functionalization as a means for promoting the electrochemical performance in electrosynthesis and beyond.

关键词： carbon dioxide(CO_(2))electroreduction interfacial microenvironment molecular surface functionalization In_(2)O_(3)catalyst water and CO_(2)diffusion

A Quasi-periodic Oscillation of ~4.6 yr in the Radio Light Curves of Blazar PKS 0607-157

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

Research in Astronomy and Astrophysics 2023年第9期23卷 105-113页

作者： Xiao-Pan Li Hai-Yan Yang Yan Cai Xie-fei song Hai-Tao Yang Yu-Qiong Shan College of Physics and Information Engineering Zhaotong UniversityZhaotong 657000China

We present periodicity search analyses on long-term radio light curves at 4.8,8,and 14.5 GHz of blazar PKS 0607–157 observed by the University of Michigan Radio Astronomical Observatory *** highly variable radio emissions are approximately distributed as a log-normal probability distribution *** Power Spectral Density for the radio light curves can be well characterized by a power-law *** the Weighted Wavelet Z-transform and Lomb-Scargle periodogram methods,significant Quasi-periodic Oscillation(QPO)of∼4.6 yr in the radio light curve has been observed above the 3σconfidence level,which presents an interesting case among blazar QPO *** explore three plausible physical models to explain the observed QPOs:a supermassive binary black hole system,Lense-Thirring precession of the disk,and helical motion of plasma blobs within the jet.

关键词： galaxies active-(galaxies )BL Lacertae objects general-(galaxies )BL Lacertae objects individual(PKS 0607-157)

Simulation of optimal work extraction for quantum systems with work storage

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第2期33卷 195-203页

作者：宋鹏飞张旦波 Key Laboratory of Atomic and Subatomic Structure and Quantum Control(Ministry of Education) and School of PhysicsSouth China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials Guangdong–Hong Kong Joint Laboratory of Quantum Matterand Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China

The capacity to extract work from a quantum heat machine is not only of practical value but also lies at the heart of understanding quantum *** this paper,we investigate optimal work extraction for quantum systems with work storage,where extracting work is completed by a unitary evolution on the composite *** consider the physical requirement of energy conservation both strictly and on *** both,we construct their corresponding unitaries and propose variational quantum algorithms for optimal work *** show that maximal work extraction in general can be feasible when energy conservation is satisfied on *** demonstrate with numeral simulations using a continuous-variable work *** work show an implementation of a variational quantum computing approach for simulating work extraction in quantum systems.

关键词： quantum algorithm quantum thermodyanmics

Astrometric Observations of NEA 1998 HH49 Using the Daocheng 50 cm Telescope

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7期24卷 71-78页

作者： Huan Xu Xiang-Ming Cheng Yi-Gong Zhang Teng-fei song Zhen-Jun Zhang Qing-Yu Peng Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China Engineering Laboratory on Applied Astronomical Technology of Yunnan Kunming 650216China School of Information Engineering Kunming UniversityKunming 650214China School of Computer Science and Information Engineering Anyang Institute of TechnologyAnyang 455000China Department of Computer Science Jinan UniversityGuangzhou 510632China Sino-French Joint Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China

This study details an astrometric observation campaign of the Near-Earth Asteroid 1998 HH49,conducted with the aim of refining our understanding of its physical *** the 50 cm telescope located at the Wumingshan Mountain in Daocheng,Sichuan,images were obtained over four nights,from 2023 October 19 to October *** observations were processed using Astrometrica software,facilitating the precise determination of the asteroid's *** observational results were compared with the ephemerides from three distinct sources to verify accuracy:the Jet Propulsion Laboratory(JPL)Horizons System,the Institut de Mécanique Céleste et de Calcul deséphémérides(IMCCE)Miriade,and the Near-Earth Objects Dynamic Site(NEODyS-2).When compared with the JPL ephemeris,a mean observed-minus-calculated(O-C)result of 0.″07 in the *** and-0.″35 in the *** was ***,the comparison with the IMCCE ephemeris yielded mean O-C results of 0.″08 in the *** and-0.″06 in the *** comparison with the NEODyS-2 ephemeris yielded the mean O-C results of 0.″06 in ***-0.″49 in *** study's findings demonstrate a general consistency between the observed data and the ephemeris predictions,with minor discrepancies observed across the data ***,both the JPL and NEODyS-2 ephemerides show that the residuals in the *** exceed those in the *** disparities may result from atmospheric differential color refraction,ephemeris discrepancies,observational errors,and other ***,it is worth noting that further investigation is required due to the potential influence of additional ***,the Daocheng 50 cm Telescope exhibits the ability to conduct high-precision positional measurements.

关键词： astrometry ephemerides time

Tunable Syngas Synthesis from Photocatalytic CO2 Reduction Under Visible-Light Irradiation by Interfacial Engineering

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2020年第5期26卷 352-361页

作者： Conghui Qiu Sha Bai Wenjing Cao Ling Tan Junyan Liu Yufei Zhao Yu-fei song State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

Visible-light-driven CO2 photoreduction to achieve renewable materials,such as syngas,hydrocarbons,and alcohols,is a key process that could relieve environmental problems and the energy crisis *** of syngas products with diff erent H2:CO proportions is highly expected to produce high value-added chemicals in the ***,the development of technologies employing long-wavelength irradiation to achieve CO2 photoreduction and simultaneous tuning of the resultant H2:CO proportion remains a challenging *** this work,we carried out interfacial engineering by designing a series of heterostructured layered double-hydroxide/MoS2 nanocomposites via electrostatic *** syngas proportion(H 2:CO)obtained from CO2 photoreduction could be modulated from 1:1 to 9:1 by visible-light irradiation(λ>400 nm)under the control of the interface-rich *** work provides a cost-eff ective strategy for solar-tofuel conversion in an artificial photosynthetic system and describes a novel route to produce syngas with targeted proportions.

关键词： Interfacial engineering LDH/MoS2 CO2 photoreduction Syngas synthesis Heterostructure