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Translocation of Polymer Chains Through a Channel with Complex Geometries

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Chinese Journal of Chemical Physics 2008年第6期21卷 555-559页

作者： zhi-yong yang Lin-xi Zhang Jun Cheng Department of Physics Wenzhou University Wenzhou 325027 China

The elastic behavior of a single chain transporting through complex channel which can be seen as the combination of three different channels （left channel, middle channel, and right channel, respectively） is investigated using the new pruned-enriched Rosenbluth method with importance sampling. The elastic force during the translocation process is calculated. At the entrance into the middle channel, there is the first plateau in the curve of the elastic force f （f〉0） versus x, here x represents the position of the first monomer along the x-axis direction. When the first monomer moves to a certain position, a second plateau is observed with the elastic force f〈0, which represents spontaneous translocation. The free energy difference between the subchain in the right channel and the subchain in the left channel may drive the transloeation. The influence of chain length and width of the left and right channels on the translocation process are also investigated. From the simulation results, more detailed explanations for the reason why the component translocation time is not the same for different channels can be presented.

关键词： Elastic behavior nPERMis Polymer translocation

Pinhole imaging to observe spatial jitters of a triple-pulse X-ray source on the Dragon-Ⅱ LIA

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Nuclear Science and Techniques 2016年第5期27卷 140-145页

作者： Yi Wang zhi-yong yang Xiao-BingJing Qin Li Heng-Song Ding zhi-yong Dai Key Laboratory of Pulsed Power Institute of Fluid Physics China Academy of Engineering Physics Mianyang 621900 China

In high-energy flash radiography,scattered photons degrade the acquiring image,which limits the resolving power of interfaces and density of dense *** application of large anti-scatter grid can reduce the scattered photons remarkably,but this requires a stable source position in order to reduce the loss of signal photons in the grid *** pinhole imaging technique is applied to observe spatial jitters of a triple-pulse radiographic source of a linear induction *** simulations are conducted to analyze the imaging performance with the same or close parameters of the pinhole object and experimental *** are carried out to observe spatial jitters of the source between different *** of the source position between different pulses are measured in each experiment.

关键词：针孔成像 X射线源空间脉冲直线感应加速器抖动高能闪光照相散射光子

Factors affecting the pilot trading market of carbon emissions in China

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Petroleum Science 2018年第2期15卷 412-420页

作者： yong Jiang Ya-Lin Lei yong-zhi yang Fang Wang School of Humanities and Economic Management China University of GeosciencesBeijing 10083China Key Laboratory of Carrying Capacity Assessment for Resources and Environment Ministry of Land and ResourcesBeijing 100083China Petrochina Research Institute of Petroleum Exploration and Development Beijing 100083China

Climate change and carbon emissions are major problems which are attracting worldwide attention. China has had its pilot carbon emission trading markets in seven regions for more than 3 years. What affects carbon emission trading market in China is a big question. More attention is paid to how China promotes the carbon emission trading schemes in the whole country. This paper addresses concerns about the functioning of carbon emission trading schemes in seven pilot regions and takes the weekly data from November 25, 2013, to March 19, 2017. We employ a vector autoregressive model to study how coal price, oil price and stock index have affected the carbon price in China. The results indicate that carbon price is mainly affected by its own historical price; coal price and stock index have negative effects on carbon price, while oil price has a negative effect on carbon price during the first 3 weeks and then has a positive effect on carbon price. More regulatory attention and economic measures are needed to improve market efficiency, and the mechanisms of carbon emission trading schemes should be improved.

关键词： Carbon emission trading market Carbon price VAR model China

Atomic-scale characterization of multiple precipitating species in a precipitation-hardened martensitic stainless steel

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Journal of Iron and Steel Research International 2022年第2期29卷 207-214页

作者： Zhen-bao Liu Zhe yang Jian-xiong Liang zhi-yong yang Guang-min Sheng Division of Special Steels Central Iron and Steel Research Institute(CISRI)Beijing100081China School of Material Science and Engineering Chongqing UniversityChongqing400044China

Multiple precipitating species in a 2.2 GPa grade precipitation-hardened martensitic stainless steel with balanced ductility were characterized at atomic scale by atom probe *** results indicated that the clustering of solute atoms was promoted with progressive aging treatments.(Cr,Mo)-rich carbide(M_(2)C)precipitated at the linear dislocations in the as-aged *** segregation of Cr,Mo,and C at phase boundaries favored the precipitation of carbide and caused the formation of Cr-lean *** decomposition of martensitic matrix during aging led to the substantial precipitation of fine Cr-rich(α′Cr)*** with the first aging treated samples,a synergistic enhancement of both strength and ductility of the secondary aging treated(SAT)samples was primarily ascribed to the enhanced precipitation of Cr-rich ***,Ni-rich filmy reversed austenite precipitated at the lath boundary,which was beneficial to the ductility of SAT samples.

关键词： Aging treatment Nanoprecipitate Atom probe Spinodal decomposition Precipitation-hardened martensitic stainless steel

CO_(2)storage with enhanced gas recovery(CSEGR):A review of experimental and numerical studies

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Petroleum Science 2022年第2期19卷 594-607页

作者： Shu-yang Liu Bo Ren Hang-Yu Li yong-zhi yang zhi-Qiang Wang Bin Wang Jian-Chun Xu Ramesh Agarwal Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Bureau of Economic Geology The Jackson School of GeosciencesThe University of Texas at AustinAustinTXUSA Research Institute of Petroleum Exploration and Development Beijing100083China Tsinghua-Berkeley Shenzhen Institute Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055GuangdongChina Washington University in St.Louis St.LouisMO63130USA

CO_(2)emission mitigation is one of the most critical research *** a promising option of carbon capture,utilization and storage(CCUS),CO_(2)storage with enhanced gas recovery(CSEGR)can reduce CO_(2)emission by sequestrating it into gas reservoirs and simultaneously enhance natural gas *** the past decades,the displacement behaviour of CO_(2)—natural gas has been extensively studied and demonstrated to play a key role on both CO_(2)geologic storage and gas recovery *** work thoroughly and critically reviews the experimental and numerical simulation studies of CO_(2)displacing natural gas,along with both CSEGR research and demonstration projects at various *** physical property difference between CO_(2)and natural gas,especially density and viscosity,lays the foundation of *** experiments on displacement behaviour and dispersion characteristics of CO_(2)/natural gas revealed the fundamental mixing characteristics in porous media,which is one key factor of gas recovery efficiency and warrants further *** numerical simulations demonstrated that it is technically and economically feasible to apply CSEGR in depleted gas ***,CO_(2)preferential flow pathways are easy to form(due to reservoir heterogeneity)and thus adversely compromise CSEGR *** preferential flow can be slowed down by connate or injected ***,the optimization of CO_(2)injection strategies is essential for improving gas recovery and CO_(2)storage,which needs further *** successful K12—B pilot project provides insightful field-scale knowledge and experience,which paves a good foundation for commercial *** experiments,simulations,research and demonstration projects are needed to facilitate the maturation of the CSEGR technology.

关键词： Carbon capture Utilization and storage(CCUS) Enhanced gas recovery CO_(2)geologic storage Miscible displacement Dispersion

Temporal variations of CO_2 concentration near land surface and its response to meteorological variables in Heihe River Basin, northwest China

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Journal of Environmental Sciences 2006年第4期18卷 708-715页

作者： CHEN Ren-sheng KANG Er-si JI Xi-bin yang Jian-ping ZHANG zhi-hui yang yong Laboratory of Watershed Hydrology and Ecology Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy ofSciences Lanzhou 730000 China

Atmospheric CO2 concentration （CC） near land surface and meteorological variables have been measured at four sites, named Yeniugou （alpine meadow and permafrost）, Xishui （mountainous forest）, Linze （oasis edge） and Ejina （lower desert）, respectively, in Heihe River Basin, northwest China. The results showed that, the half hourly CC at night was larger than in daytime, and the daily averaged CC was the largest in winter. The averaged CC of 932 d at the Linze was about 418 ppm, was about 366 ppm in the 762 d at the Ejina. In the same period from September 23 to November 9, 2004, the averaged CC was about 625,334, 436 and 353 ppm, at Yeniugou, Xishui, Linze and Ejina, respectively. The linear relationship between daily averaged CC and air temperature T was negative, between CC and relative humidity （RH） was positive. The linear CC-atmospheric pressure （A P） relationship was negative at the Linze and Yeniugou, was positive at the Ejina. The relationship between CC and global radiation R was exponent, and soil temperature Ts was negative linear, and soil water content was complex. The correlation between CC and wind speed was not existent. Using meteorological variables together to simulate CC, could give good results.

关键词： CO2 concentration meteorological variables Heihe River Basin

Carbide dissolution and austenite grain growth behavior of a new ultrahigh-strength stainless steel

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Journal of Iron and Steel Research International 2020年第6期27卷 732-741页

作者： Zhen-bao Liu Xin Tu Xiao-hui Wang Jian-xiong Liang zhi-yong yang yong-qing Sun Chang-jun Wang Institute for Special Steel Institute Central Iron and Steel Research InstituteBeijing 100081China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

The isothermal grain growth behavior for a new ultrahigh-strength stainless steel (UHSSS) is investigated in temperature range from 900 to 1150 ℃ and holding time range from 0 to 20 min. In the temperature range from 1000 to 1050 ℃, a bimodal grain size distribution was induced by different austenite grain growth rates which resulted from the weakened pin-ning effect by the partial dissolution of M6C particles along austenite grain boundaries. Further raising heating temperatures, M6C particles almost dissolved and the bimodal grain size distribution phenomenon became weakened, indicating that the austenite grain coarsening temperature of the new UHSSS was close to 1050 ℃. According to the present experimental results, a pragmatic mathematical model based on the Arrhenius equations was developed to predict the austenite grain growth process, which elaborated the influence of heating temperature, holding time and initial grain size on the austenite grain growth. Predictions for the new UHSSS presented a good agreement with experimental results.

关键词： Ultrahigh-strength stainless steel Austenite grain growth Mathematical model M6C particle

PRESSURE CHARACTERISTICS OF CAVITATION CONTROL BY AERATION

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Journal of Hydrodynamics 2005年第6期17卷 764-769页

作者： DONG zhi-yong LU yang-quan JU Wen-jie CAI Xin-ming DING Chun-sheng School of Civil and Architectural Engineering Zhejiang University of Technology Hangzhou 310032 China

This experimental investigation was systernatically conducted with the aid of a non-circulating water tunnel in the Hydraulics Laboratory at Zhejiang University of Tech nology in China, The test velocity is between 20m/s and 40m/ s. The least air concentration to prevent cavitation erosion lies between 1. 7% and 4. 5%. Pressure waveforms with and without aeration in cavitation and cavitation erosion regions were measured. Time-averaged pressure profiles with and without aeration were compared. Pressure characteristics cotresponding to least air concentration to prevent cavitation erosion in cavitation and cavitation erosion regions were analyzed.

关键词： pressure increase compression wave cavitation control by aeration least air concentration eavitation number

Influence of Cy berKnife Prescription Isodose Line on the Discrepancy of Dose Results Calculated by the Ray Tracing and Monte Carlo Algorithms for Head and Lung Plans: A Phantom Study

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Current Medical Science 2020年第2期40卷 301-306页

作者： Jing yang Gang LIU Hong-yuan LIU Xin NIE zhi-yong yang Jun HAN Sheng ZHANG zhi-wen LIANG Cancer Center Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430023China

Incorporation of the Monte Carlo(MC)algorithm in optimizing CyberKnife(CK)plans is cumbersome,and early models unconfigured MC calculations,therefore,this study investigated algorithm-based dose calculation discrepancies by selecting different prescription isodose lines(PIDLs)in head and lung CK *** plans were based on anthropomorphic *** shells were set at 2-60 mm from the target,and the constraint doses were adjusted according to the design *** optimization,30%-90%PIDL plans were generated by ray tracing(RT).In the evaluation module,CK plans were recalculated using the MC ***,the dosimetric parameters of different PIDL plans based on the RT and MC algorithms were obtained and *** discrepancies(mean+SD)were 3.72%+0.31%,3.40%+0.11%,3.47%+0.32%,0.17%+0.11%,0.64%+3.60%,7.73%+1.60%,14.62%+3.21%and 10.10%+1.57%for Djs,Dmeam),Dys,and coverage of the PTV,DGI,V,,V;and V,in the head plans and-6.32%+1.15%,-13.46%+0.98%,-20.63%+2.25%,-34.78%+25.03%,12248%+175.60%,-12.92%+5.41%,3.19%+4.67%and 7.13%+1.56%in the lung plans,*** following parameters were significantly correlated with PIDL:dp98%at the 0.05 level and dpal,dys and dv3 at the 0.01 level for the head plans;dp98e%at the 0.05 level and do1e%,dpmeam,Ccoweange,dool,dvs and dv;at the 0.01 level for the lung *** may be used to calculate the dose in CK head plans,but when the dose of organs at risk is close to the limit,it is necessary to refer to the MC results or to further optimize the CK plan to reduce the *** lung plans,the MC algorithm is *** early models without the MC algorithm,a lower PIDL plan is recommended;otherwise,a large PIDL plan risks serious underdosage in the target area.

关键词： CyberKnife prescription isodose line Monte Carlo ray tracing phantom