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Chemical inequivalence behavior of the protons attached to the same carbon in ethylene-propylene copolymer(EPC)

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Chinese Chemical Letters 2008年第4期19卷 469-474页

作者： Peng Yu Bi Hui Ru dong nan nan Wang College of Science Beijing University of Chemical TechnologyBeijing 100029PR China

Six ethylene-propylene copolymer samples with different structural parameters were analyzed by ^1H NMR,^13C NMR and ^1H-^13C COSY in this *** the aid of the ^1H-^13C COSY spectra of ethylene-propylene copolymer,the chemical inequivalence behavior of the protons attached to the same carbon in the ethylene-propylene copolymer could be observed. Four basic types of chemical bonds were divided,and two kinds of main conformations were proposed to explain this phenomenon. Based on the calculation of conformation distribution,it can be proved that the explanation of this phenomenon was reasonable.

关键词： Chemical inequivalence Ethylene-propylcne copolymer NMR

High sensitivity dual polarization four channels surface plasmon resonance refractive index sensor with wide detection range and high linearity based on photonic crystal fiber

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Optoelectronics Letters 2025年

作者： CUI nan PAN Honggang ZHANG Ailing ZHAO Zihong CHEN Zhipan ZHANG Bo Tianjin Key Laboratory of Film Electronic and Communication Devices， Engineering Research Center of Optoelectronic Devices and Communication Technology， Ministry of Education， School of Integrated Circuit Science and Engineering， Tianjin University of Technology

In this paper， we propose and numerically characterize the optical characteristics of a high sensitivity dual polarization four channels surface plasmon resonance refractive index sensor with wide detection range and high linearity based on photonic crystal fiber （PCF）. Four light transmission channels are constructed by using big air holes. The small rectangular air hole in the center of the fiber core is used to add asymmetry. We use gold plasma material to achieve better sensing performance. A thin film of TiO2is placed on the PCF surface， which assists gold in the adhesion on PCF. The maximum wavelength sensitivity of the sensor can reach 20000 nm/RIU in both x and y polarization modes. While the maximum wavelength resolution of the sensor is 5×10-6RIU. The average wavelength sensitivity reached 15900nm/RIU and 15800nm/RIU in x and y polarization mode. The sensor features R2=0.9969 / R2=0.9966 high linear performance in x and y polarization mode and the maximum FOM values 509.13 RIU-1/ 489.63 RIU-1in x and y polarization mode. Besides the sensor’s detection range is 1.26-1.36， which is a wide refractive index detection range. The sensor has a wide range of applications in biomedical and other fields.

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By the power of young researchers

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Environmental Science and Ecotechnology 2021年第4期8卷 10-12页

作者： nan-Qi ren State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin150090China

Anchored in this changing time,science and technologies matter;yet young researchers matter *** is not simply that in time they will grow to be the next generation of experienced scientists,but that,at this point in their career,their fearlessness and ambitions make them driving forces of evolutional changes,adventurers pushing intellectual boundaries,and navigators in the big *** is exactly why we called out the inaugural EarlyCareer Editorial Board(ECEB)of Environmental Science and Ecotechnology.

关键词： technology. driving young

Isolation and Characterization of Vagococcus fluvialis from Bats

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Biomedical and Environmental Sciences 2021年第10期34卷 834-837页

作者： QIN Tian JIANG Lu Xi ren Hong Yu JIA Xue Yang NIE Xu dong LI Yi nan State Key Laboratory for Infectious Disease Prevention and Control Collaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesNational Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijing 102206China Department of Respiratory Medicine Zhejiang Provincial People's HospitalPeople's Hospital of Hangzhou Medical CollegeHangzhou 310000ZhejiangChina

The genus Vagococcus was first described by *** initially consisted of a single species,*** species was isolated from chicken feces and river water and first described by Hashimoto et al.[1,2].Teixeira et *** *** from... 详细信息

关键词： initially fluvialis coccus

Hydrodynamic characteristics of a four-compartment periodic anaerobic baffled reactor

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Journal of Environmental Sciences 2007年第10期19卷 1159-1165页

作者： LIU Xiao-lei ren nan-qi WAN Chun-li School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China School of Water Conservancy and Environment Engineering Changchun Institute of Technology Changchun 130012 China

Periodic anaerobic baffled reactor （PABR） is a novel reactor based on the design concept of anaerobic baffled reactor （ABR）. Residence time distribution （RTD） studies on both clean and working reactors at the same hydraulic residence time （HRT） of 2 d were carded out to investigate the dead spaces and mixing patterns in PABRs at different organic loading rates （OLRs） in various switching manners and frequencies. The results showed that the fraction of dead space in PABR was similar to that in ABR, which was low in comparison with other reactor designs. Dead space may be divided into two categories, hydraulic and biological. In RTD studies without biomass, the hydraulic dead space in the PABR run in an ＂every second＂ switching manner with T = 2 d was the lowest whereas that in the PABR run in a T = ∞ （ABR） switching manner was the highest. The same trend was obtained with the total dead space in RTD studies with biomass no matter what the OLR was. Biological dead space was the major contributor to dead space but affected decreasingly at higher OLR whichever switching manner the PABR run in. The flow patterns within the PABRs were intermediate between plug-flow and perfectly mixed under all the conditions tested,

关键词： dead space residence time distribution periodic anaerobic baffled reactor anaerobic processes wastewater treatment

Characteristics of subsurface mesoscale eddies in the northwestern tropical Pacifi c Ocean from an eddy-resolving model

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Journal of Oceanology and Limnology 2020年第5期38卷 1421-1434页

作者： XU Anqi YU Fei nan Feng ren Qiang Institute of Oceanology Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Ocean Circulation and Waves Chinese Academy of SciencesQingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China Marine Dynamic Process and Climate Function Laboratory Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

Subsurface eddies(SSEs)are common features of the ocean *** are particularly abundant in oceanic basins and the vicinity of major intermediate water outfl *** are responsible for subsurface transport of mass,heat,and *** of high-resolution general circulation model data has revealed the existence of subsurface anticyclonic eddies(SSAEs)and subsurface cyclonic eddies(SSCEs)in the northwestern tropical Pacifi c *** are abundant east of the Philippines(0°–22°N,120°E–140°E)and in latitude bands between 9°N–17°N east of 140°*** composite structure of SSEs was *** had a core at about 400-m water depth and their maximum meridional velocity exceeded 10 cm/*** exhibited two cores with diff erent salinity polarities in the surface and ***,spatial distributions of heat transport induced by SSEs in the northwestern tropical Pacifi c were presented for the fi rst time.A net equatorward heat fl ux toward a temperature up-gradient was *** analysis of eddy-mean fl ow interactions revealed that the circulation is baroclinically and barotropically unstable at diff erent depths and to diff ering *** energy conversions suggest that both barotropic and baroclinic instabilities are responsible for SSE generation east of the Philippines,whereas baroclinic instability caused by a horizontal density gradient and vertical eddy heat fl ux are important between 9°N and 17°N east of 140°*** movement of the north equatorial current and the north equatorial undercurrent can contribute to SSE generation in our study region.

关键词： the northwestern tropical Pacifi c Ocean subsurface eddies composite structures heat transport energy source

Reliability of the Ultimate Strength of Ship Stiffened Panel Subjected to Random Corrosion Degradation

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China Ocean Engineering 2017年第1期31卷 11-18页

作者： FENG Guo-qing HU Bing-nan ren Hui-long College of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China

Attentions have been increasingly paid to the influence of the corrosion on the ultimate strength of ship structures. In consideration of the random characteristics of the corrosion of ship structures, the method for the ultimate strength analysis of the ship stiffened panel structure subjected to random corrosion degradation is presented. According to the measured corrosion data of the bulk carriers, the distribution characteristics of the corrosion data for the stiffened panel on the midship deck are analyzed, and a random corrosion model is established. The ultimate strength of the corroded stiffened panel is calculated by lhe nonlinear finite element analysis. The statistical descriptions of the ultimate strength of the corroded stiffened panel are defined through the Monte Carlo simulations. A formula is proposed on the ultimate strength reduction of the stiffened panel as a function of the corrosion volume. The reliability analysis of the ultimate strength of the corroded deck stiffened panel is performed. It shows that both the corrosion data of the deck stiffened panel and the ultimate strength of the random corroded deck stiffened panel follow the log-normal distribution. The ultimate stress ratio of the stiffened panel is inversely proportional to the corrosion volume ratio.

关键词： stiffened panel corrosion ultimate strength time variant reliability corrosion volume /:~no- ~T (~ ~11 R NI R^n l-I I. 9017 Rollnhilltvnftho.ltlmnto ~trontrth nf^hl

Lattice Boltzmann simulation of the effects of cavity structures and heater thermal conductivity on nucleate boiling heat transfer

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Applied Mathematics and Mechanics(English Edition) 2023年第6期44卷 981-996页

作者： Fanming CAI Zhaomiao LIU nan ZHENG Yanlin ren Yan PANG Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

The boiling heat transfer technology with cavity surfaces can provide higher heat flux under lower wall superheat,which is of great significance for the cooling of electronic chips and microelectromechanical *** this paper,the boiling characteristics of the cavity surfaces are investigated based on the lattice Boltzmann(LB)method,focusing on the effects of cavity shapes,sizes,and heater thermal conductivity on the heat transfer *** results show that the triangular cavity has the best boiling performance since it has less residual vapor and higher bubble departure frequency than those of the trapezoidal and rectangular *** the cavity size increases,the enhancement of heat transfer by the cavity mouth is suppressed by the heat accumulation effect at the heater *** liquid rewetting process during bubble departure is the reason for the fluctuation of the space-averaged heat flux,and the heater thermal conductivity determines the fluctuation *** evaporation of liquid in the cavity with high thermal conductivity walls is more intense,resulting in shorter waiting time and higher bubble departure frequency.

关键词： lattice Boltzmann(LB)method boiling cavity conjugate heat transfer

Evaluation of aquatic rehabilitation technologies for polluted urban rivers and the case study of the Foshan Channel

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Frontiers of Environmental Science & Engineering 2010年第2期4卷 213-220页

作者： Haifeng JIA nan dong Hongtao MA Department of Environmental Sciences&Engineering Tsinghua UniversityBeijing 100084China

An index system for evaluation of technologies for urban river rehabilitation was proposed and *** index system includes indicators of cost,resources,environmental improvement,and social *** calculation method for an objective value of each index based on its attributes and weights was *** Foshan Channel,which is a seriously polluted,black and malodorous urban river in Foshan City,China,was selected as a case *** values of the attributes and the weights of the indices for the Foshan Channel were *** technologies for the rehabilitation of the Foshan Channel were evaluated based on this index ***,a rehabilitation scheme for the Foshan Channel was proposed.

关键词： river rehabilitation urban rivers river pollution multi-objective analysis the Foshan Channel