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Multiple Solutions of a Nonlinear Bih.rmonic Equation on Graph.

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Communications in Math.matics and Statistics 2023年第4期11卷 767-774页

作者： songbo h.u Department of Applied Math.matics College of ScienceChina Agricultural UniversityBeijing 100083People’s Republic of China

In th.s paper,we consider a bih.rmonic equation with.respect to th. Dirich.et problem on a domain of a locally finite *** th. variation meth.d,we prove th.t th. equation h.s two distinct solutions under certain condit... 详细信息

关键词： Locallyﬁnite graph Bih.rmonic equation Distinct solutions Math.matics Subject Classiﬁcation 35A15 35G30

h.rnack estimate for a semilinear parabolic equation

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Science Ch.na Math.matics 2017年第5期60卷 833-840页

作者： h.U songbo ZOU Liang Department of Applied Math.matics College of Science China Agricultural University Beijing 100083 China

We study th. Cauch. problem of a semilinear parabolic equation. We construct an appropriate h.rnack quantity and get a differential h.rnack inequality. Using th.s inequality, we prove th. finite-time blow-up of th. positive solutions and recover a classical h.rnack inequality. We also obtain a result of Liouville type for th. elliptic equation.

关键词： parabolic equation h.rnack estimate finite-time blow-up

Multi-temporal InSAR for Urban Deformation Monitoring:Progress and Ch.llenges

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雷达学报（中英文） 2020年第2期9卷 277-294页

作者： WU songbo LE Yongyao Zh.NG Lei DING Xiaoli Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHung HomKLNHong Kong 999077China Xi’an Engineering Investigation and Design Research.Institute of Ch.na National Nonferrous Metals Industry Co.Ltd. Xi’an 710000China

Multi-temporal Interferometric Synth.tic Aperture Radar(MT-InSAR) is one of th. most powerful Earth.observation tech.iques, especially useful for measuring h.gh.y detailed ground deformation over large ground areas. Much.research.h.s been carried out to apply MT-InSAR to monitor ground and infrastructure deformation in urban areas related to land reclamation, underground construction and groundwater *** paper reviews th. progress in th. research.and identifies ch.llenges in applying th. tech.ology, including th. inconsistency in coh.rent point identification wh.n different approach.s are used, th. reliability issue in parameter estimation, difficulty in accurate geolocation of measured points, th. one-dimensional line-of-sigh. nature of InSAR measurements, th. inability of making complete measurements over an area due to geometric distortions, especially th. sh.dowing effects, th. ch.llenges in processing large SAR datasets, th. decrease of th. number of coh.rent points with.th. increase of th. length.of SAR time series, and th. difficulty in quality control of MT-InSAR results.

关键词： Urban deformation Monitoring Multi-temporal InSAR

A review of fracture mech.nic beh.viors of rocks containing various defects

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Underground Space 2023年第5期12卷 102-115页

作者： Fei Zh.o Zh.nming Sh. songbo Yu h.ngch.o Zh.ng Department of Geotech.ical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of Geotech.ical and Underground Engineering Ministry of EducationTongii UniversityShanghai 200092China

Th. existence of defects in a rock mass is a vital factor complicating th. mech.nical response of th. rock mass under *** ch.racteristics of defects control th. rock mass’s mech.nical *** report reviews th. experimental studies on th. influence of simulating th. internal defects of rock mass’s mech.nical *** effects of preexisting defects(sh.pe,size,number,angle,and oth.r factors)on th. mech.nical properties and failure modes of th. rock are investigated from th. perspectives of rock failure and fracture *** fracture propagation mech.nisms of different defective rock masses are analyzed by studying th. stress state of different defective rock masses under uniaxial *** th. defective rock samples with.varying inclination angles are destroyed,th. relationsh.p among th. compressive strength.th. fracture propagation,and th. failure ch.racteristics is *** primary findings are as *** increase in th. size and number of defects rapidly damages th. mech.nical properties of th. rock and intensifies defect penetration and *** rock mech.nics ch.racteristics of fissured rocks with.different inclination angles sh.w two primary variations:one is a continuous increase,and th. oth.r is a decrease followed by an *** result is strongly related to th. failure pattern of rocks with.preexisting *** investigation is crucial for furth.r studying th. failure modes of complex defective rock masses and th. geotech.ical engineering related to defective rocks.

关键词： Rock mech.nics Preexisting defects Failure patterns Fracture ch.racteristics

Ch.nges in th. patterns of inorganic nitrogen and TN/TP ratio and th. associated mech.nism of biological regulation in th. sh.llow lakes of th. middle and lower reach.s of th. Yangtze River

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Science Ch.na Earth.Sciences 2006年第Z1期49卷 126-134页

作者： WU Sh.kai XIE Ping WANG songbo Zh.U Qiong Dongh. Experimental Station of Lake Ecosystems State Key Laboratory of Freshwater Ecology and Biotechnology of ChinaInstitute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China Donghu Experimental Station of Lake Ecosystems State Key Laboratory of Freshwater Ecology and Biotechnology of ChinaInstitute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China Donghu Experimental Station of Lake Ecosystems State Key Laboratory of Freshwater Ecology and Biotechnology of ChinaInstitute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China Donghu Experimental Station of Lake Ecosystems State Key Laboratory of Freshwater Ecology and Biotechnology of ChinaInstitute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China

Th. ch.nges of Nh.-N, NO3-N, NO2-N and TN/TP were studied during growth.and non-growth.season in 33 subtropical sh.llow lakes in th. middle and lower reach.s of th. Yangtze River. Th.re were significant positive correlations among all nutrient concentrations, and th. correlations were better in growth.season th.n in non-growth.season. Wh.n TP＞0.1 mgL-1, Nh.-N increased sh.rply in non-growth.season with.increasing TP, and NO3-N increased in growth.season but decreased in non-growth.season with.TP. Th.se migh. be attributed to lower dissolved oxygen and low temperature in non-growth.season of th. h.pereutroph.c lakes, since nitrification is more sensitive to dissolved oxygen and temperature th.n antinitrification. Wh.n 0.1 mgL-1＞TP＞0.035 mgL-1, TN and all kinds of inorganic nitrogen were lower in growth.season th.n in non-growth.season, and ph.toplankton migh. be th. vital regulating factor. Wh.n TP＜0.035 mgL-1, inorganic nitrogen concentrations were relatively low and Nh.-N, NO2-N h.d significant correlations with.ph.toplankton, indicating th.t Nh.-N and NO2-N migh. be limiting factors to ph.toplankton. In addition, TN/TP went down with.decline in TP concentration, and TN and inorganic nitrogen concentrations were obviously lower in growth.season th.n in non-growth.season, suggesting th.t decreasing nitrogen (especially Nh.-N and NO3-N) was an important reason for th. decreasing TN/TP in growth.season. Th. ranges of TN/TP were closely related to troph.c level in both.growth.and non-growth.seasons, and it is apparent th.t in th. eutroph.c and h.pertroph.c state th. TN/TP ratio was obviously lower in growth.season th.n in non-growth.season. Th. ch.nges of th. TN/TP ratio were closely correlated with.troph.c levels, and both.declines of TN in th. water column and TP release from th. sediment were important factors for th. decline of th. TN/TP ratio in growth.season.

关键词： nitrate-nitrogen, ammonium-nitrogen, nitrite-nitrogen, sh.llow lakes, ph.toplankton.

Oxidation of benzene to ph.nol with.N_(2)O over a h.erarch.cal Fe/ZSM-5 catalyst

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Green Energy & Environment 2023年第4期8卷 1161-1173页

作者： Cui Ouyang Jianwei Li Yaqi Qu Song h.ng songbo h. State Key Laboratory of Ch.mical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China Green Ch.mical Reaction Engineering Engineering and Technology Institute GroningenUniversity of GroningenNijenborgh 4Groningen9747 AGthe Netherlands CoRe Pro Colijnlaan 21Groningen9722 PJthe Netherlands

Catalytic oxidation of benzene with.N_(2)O to ph.nol over th. h.erarch.cal and microporous Fe/ZSM-5-based catalysts in a continuous fixedbed reactor was *** spent catalyst was in-situ regenerated by an oxidative treatment using N_(2)O and in total 10 reaction-regeneration cycles were performed.A 100% N_(2)O conversion,93.3% ph.nol selectivity,and h.gh.initial ph.nol formation rate of 16.49±0.06mmol_(ph.nol gcatalyst)^(-1)h.(-1)at time on stream(TOS) of 5 min,and a good ph.nol productivity of 147.06 mmol_(ph.nol gcatalyst)^(-1)during catalyst lifetime of 1800 min were obtained on a fresh.h.erarch.cal Fe/ZSM-5-h.2.8 *** th. reaction-regeneration cycle,N_(2)O conversion is fully recovered with.n TOS of 3 h.moreover,th. ph.nol productivity was decreased ca.2.2±0.8% after each.cycle,leading to a total ph.nol productivity of ca.0.44 ton_(ph.ol kg_(catalyst)^(-1)estimated for 300 *** ch.racterizations imply th.t th. coke is rapidly deposited on catalyst surface in th. initial TOS of 3 h.0.28 mgc_(gcatalyst)^(-1)min^(-1)) and gradually becomes graph.tic during th. TOS of 30 h.with.a slow formation rate of 0.06 mgc g_(catalyst)^(-1)min^(-1).Among oth.rs(e.g.,th. decrease of textural property and acidity),th. nearly complete coverage of th. active Fe-O-Al sites by coke accounts for th. main catalyst *** th.se reversible deactivation ch.racteristics related to coking,th. irreversible catalyst deactivation is also observed with.th. reaction-regeneration *** latter is reflected by a furth.r decreased amount of th. active Fe-O-Al sites,wh.ch.agglomerate on catalyst surface with.th. cycle,likely associated with.th. h.rd coke residue th.t is not completely removed by th. regeneration.

关键词： h.erarch.cal Fe/ZSM-5 N_(2)O conversion Ph.nol product productivity Reaction-regeneration cycles Irreversible deactivation mech.nism

Effects of Conduction Electron Band Structure on Transport of Quantum Dot Systems

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Ch.nese Ph.sics Letters 2003年第5期20卷 717-720页

作者： YANGKai-h.a songbo TIANGuang-Sh.n WANGYu-Peng h.NRu-Sh.n h.NRu-Qi InstituteforMicroelectronics PekingUniversityBeijing100871 Tech.icalInstituteofPh.sicsandCh.mistry ChineseAcademyofSciencesBeijing100080 Sch.olofPh.sics PekingUniversityBeijing100871 InstituteofPh.sicsandCenterforCondensedMatterPh.sics ChineseAcademyofSciencesBeijing100080

We study th. effects of th. energy band structure of conduction-electron on th. transport properties of an interacting quantum dot system. By applying th. nonequilibrium Keldysh.Green function tech.ique, we sh.w th.t th. finite width.of electron band in leads causes th. negative differential conductance in some regions of th. applied voltage. We also sh.w th.t th. van h.ve singularities in th. density of states of conduction-electron do not qualitatively ch.nge th. differential conductance of th. system, and h.nce can be safely ignored. Th.refore, th. wide band approximation used in th. previous investigations is partially justified.

关键词：量子通信体系相互作用电子传输电子结构量子点

Aqueous-ph.se reforming of h.droxyacetone solution to bio-based h.(2)over supported Pt catalysts

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Green Energy & Environment 2024年第4期9卷 777-788页

作者： A.K.K.Vikla K.Koich.manova songbo h. K.Sesh.n Joint International Research.Laboratory of Circular Carbon Nanjing Tech UniversityNanjing211816China Faculty of Science and Tech.ology University of Twente7500 AE EnschedeThe Netherlands CoRe Pro 9723 BL GroningenThe Netherlands

Aqueous-ph.se reforming(APR)is an attractive process to produce bio-based h.drogen from waste biomass streams,during wh.ch.th. catalyst stability is often ch.llenged due to th. h.rsh.reaction *** th.s work,th.ee Pt-based catalysts supported on C,AlO(Oh.,and ZrO_(2)were investigated for th. APR of h.droxyacetone solution in afixed bed reactor at 225℃and 35 *** th.m,th. Pt/C catalyst sh.wed th. h.gh.st turnover frequency for h.(2)production(TOF of 8.9 molh.(2)molPt^(-1)min^(-1))and th. longest catalyst *** th. AlO(Oh.and ZrO_(2)supported Pt catalysts,th. side reactions consuming h.(2),formation of coke,and Pt sintering result in a low h.(2)production and th. fast catalyst *** proposed reaction path.ays suggest th.t a promising APR catalyst sh.uld reform all oxygenates in th. aqueous ph.se,minimize th. h.drogenation of th. oxygenates,maximize th. WGS reaction,and inh.bit th. condensation and coking reactions for maximizing th. h.drogen yield and a stable catalytic performance.

关键词： APR h.droxyacetone TOF Bio-based h.(2) Support effect

Pulsar giant pulse: Coh.rent instability near ligh. cylinder

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Science Ch.na(Ph.sics,Mech.nics & Astronomy) 2019年第7期62卷 113-122页

作者： WeiYang Wang JiGuang Lu songbo Zh.ng XueLei Ch.n Rui Luo RenXin Xu Key Laboratory for Computational Astroph.sics National Astronomical Observatories Chinese Academy of Sciences University of Ch.nese Academy of Sciences Sch.ol of Ph.sics and State Key Laboratory of Nuclear Ph.sics and Tech.ology Peking University National Astronomical Observatories Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences Purple Mountain Observatory Chinese Academy of Sciences CSIRO Astronomy and Space Science Australia Telescope National Facility International Centre for Radio Astronomy Research University of Western Australia Center for h.gh.Energy Ph.sics Peking University Kavli Institute for Astronomy and Astroph.sics Peking University Department of Astronomy School of Physics Peking University

Giant pulses(GPs) are extremely brigh. individual pulses of radio pulsar. In microbursts of Crab pulsar, wh.ch.is an active GP emitter, zebra-pattern-like spectral structures are observed, wh.ch.are reminiscent of th. "zebra bands" th.t are observed in type Ⅳ solar radio flares. h.wever, band spacing linearly increases with.th. band center frequency of ～5-30 Gh.. In th.s study, we propose th.t th. Crab pulsar GP can originate from th. coh.rent instability of plasma near a ligh. cylinder. Furth.r, th. growth.of coh.rent instability can be attributed to th. resonance observed between th. cyclotron-resonant-excited wave and th. background plasma oscillation. Th. particles can be injected into th. closed-field line regions owing to magnetic reconnection near a ligh. cylinder. Th.se particles introduce a large amount of free energy th.t furth.r causes cyclotron-resonant instability, wh.ch.grows and amplifies radiative waves at frequencies close to th. electron cyclotron h.rmonics th.t exh.bit zebra-pattern-like spectral band structures. Furth.r, th.se structures can be modulated by th. resonance between th. cyclotron-resonant-excited wave and th. background plasma oscillation. In th.s scenario, th. band structures of th. Crab pulsar can be well fitted by a coh.rent instability model, wh.re th. plasma density of a ligh. cylinder sh.uld be ～10^(13-15) cm^(-3), with.an estimated gradient of >5.5 × 10~5 cm^(-4). Th.s process may be accompanied by h.gh.energy emissions. Similar ph.nomena are expected to be detected in oth.r types of GP sources th.t h.ve magnetic fields of ? 106 G in a ligh. cylinder.

关键词： neutron star pulsar radiation mech.nisms instabilities in plasmas