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Experimental Study on Oxy-Fuel Combustion and NO Emission in a Spouted-Fluidized Bed with under Bed Feeding

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作者： mingxin Kang Tielong Shen Department of Applied Science and Engineering Sophia University

ISBN: (纸本)9781538629185

This paper proposes an experimental comparison between two optimal controllers for automotive spark ignition engines, including an gain-scheduled linear quadratic regulation（LQR） controller and model predictive controller（MPC）. The aim of the study is to highlight the control effects between the LQR and MPC scheme on the specific engine control problem,and provide a reference for the future controller design. The control problem is formulated to ensure the fast torque tracking performance, and meanwhile to improve the thermal efficiency by reducing the pumping loss. The nitrogen oxide emission is chosen as constraint. The experiment were implemented on the full-scale gasoline engine, and the experiment results demonstrate the performance of the proposed optimal control designs.

关键词： Optimal Control Automotive Engines LQR MPC torque control

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Journal of Thermal Science 2021年第4期30卷 1132-1140页

作者： XU mingxin WU Yachang WU Haibo OUYANG Haodong ZHENG Shu LU Qiang National Engineering Laboratory for Biomass Power Generation Equipment North China Electric Power UniversityBeijing 102206China Shenhua Guohua Electric Power Research Institute(Beijing)Co. Ltd.Beijing 100025China

The spouted-fluidized bed is modified from the classical fluidized bed device,which combines the features of spouted and fluidized *** the present work,the performance of oxy-fuel spouted-fluidized bed combustion with under bed feeding and its effect on NO emission were systematically *** results revealed that it was feasible to use a spouted-fluidized bed combustor for oxy-fuel combustion with real flue gas *** transition from air combustion to oxy-fuel combustion was smooth and the concentration of CO_(2) in the flue gas could be as high as 90%steadily(dry base).Increasing the reaction temperature exhibited a negative effect on NO *** with that under the shallow bed,the concentration of NO in the flue gas was lower under the deep bed ***,the utilization of crush particles was favorable for suppressing NO emission because of the promoted mixing between coal particles and solid bed ***,the addition of limestone was proven to undesirably increase the NO emission during oxy-fuel spouted-fluidized bed combustion.

关键词： spouted-fluidized bed oxy-fuel combustion transition NO emission bed materials limestone

A privacy-preserving video subscription scheme with the limitation of expire date

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Science China(Information Sciences) 2017年第9期60卷 271-273页

作者： Liehuang ZHU mingxin CHEN Zijian ZHANG Ange TONG Chen XU School of Computer Science and Technology Beijing Institute of Technology

There are many video service websites(e.g.,iqiyi and youku)providing VIP *** these video services,users can register for VIP by paying fare and then they can enjoy some special services in a certain time *** just define the video subscription as an aforementioned *** and more users enjoy this form of video services and the number of the users is increasing all the ***,it is extremely easy for the video

关键词： exp more time A privacy-preserving video subscription scheme with the limitation of expire date link

Tree species classification in an extensive forest area using airborne hyperspectral data under varying light conditions

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Journal of Forestry Research 2023年第5期34卷 1359-1377页

作者： Wen Jia Yong pang Institute of Forest Resource Information Techniques Chinese Academy of ForestryBeijing 100091People’s Republic of China Key Laboratory of Forestry Remote Sensing and Information System National Forestry and Grassland AdministrationBeijing 100091People’s Republic of China

Although airborne hyperspectral data with detailed spatial and spectral information has demonstrated significant potential for tree species classification,it has not been widely used over large areas.A comprehensive process based on multi-flightline airborne hyperspectral data is lacking over large,forested areas influenced by both the effects of bidirectional reflectance distribution function(BRDF)and cloud shadow *** this study,hyperspectral data were collected over the Mengjiagang Forest Farm in Northeast China in the summer of 2017 using the Chinese Academy of Forestry's LiDAR,CCD,and hyperspectral systems(CAF-LiCHy).After BRDF correction and cloud shadow detection processing,a tree species classification workflow was developed for sunlit and cloud-shaded forest areas with input features of minimum noise fraction reduced bands,spectral vegetation indices,and texture *** indicate that BRDF-corrected sunlit hyperspectral data can provide a stable and high classification accuracy based on representative training ***-shaded pixels also have good spectral separability for species *** red-edge spectral information and ratio-based spectral indices with high importance scores are recommended as input features for species classification under varying light *** to the classification accuracies through field survey data at multiple spatial scales,it was found that species classification within an extensive forest area using airborne hyperspectral data under various illuminations can be successfully carried out using the effective radiometric consistency process and feature selection strategy.

关键词： Tree species classification BRDF effects Cloud shadow Airborne hyperspectral data Random forest

Participants Recruitment for Coverage Maximization by Mobility Predicting in Mobile Crowd Sensing

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China Communications 2023年第8期20卷 163-176页

作者： Yuanni Liu Xi Liu Xin Li mingxin Li Yi Li School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China School of Cyber Security and Information Law Chongqing University of Posts and TelecommunicationsChongqing 400065China State Key Laboratory of Networking and Switching Beijing Research Institute China UnicomBeijing 100048China

Mobile Crowd Sensing(MCS)is an emerging paradigm that leverages sensor-equipped smart devices to collect *** introduction of MCS also poses some challenges such as providing highquality data for upper layer MCS applications,which requires adequate ***,recruiting enough participants to provide the sensing data for free is hard for the MCS platform under a limited budget,which may lead to a low coverage ratio of sensing *** paper proposes a novel method to choose participants uniformly distributed in a specific sensing area based on the mobility patterns of mobile *** method consists of two steps:(1)A second-order Markov chain is used to predict the next positions of users,and select users whose next places are in the target sensing area to form a candidate pool.(2)The Average Entropy(DAE)is proposed to measure the distribution of *** participant maximizing the DAE value of a specific sensing area with different granular sub-areas is chosen to maximize the coverage ratio of the sensing *** results show that the proposed method can maximize the coverage ratio of a sensing area under different partition granularities.

关键词： data average entropy human mobility prediction markov chain mobile crowd sensing

Tracking Cryptosporidium in urban wastewater treatment plants in a cold region:Occurrence,species and infectivity

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Frontiers of Environmental Science & Engineering 2022年第9期16卷 1-14页

作者： Dan Xiao Zhaofeng Lyu Shiheng Chen Yang Huo Wei Fan mingxin Huo Jilin Academy of Agricultural Sciences Changchun 130033China School of Chemical Engineering Changchun University of TechnologyChangchun 130012China School of Environment Northeast Normal UniversityChangchun 130117China

This study investigated the occurrence,species,infectivity and removal efficiency of Cryptosporidium *** typical wastewater treatment *** from different process units were collected seasonally and synchronously from four wastewater treatment plants(WWTPs)in Northeastern *** Cryptosporidium oocysts were identified in most samples from both influent(97.50%)and effluent(90.00%)wastewaters of the four WWTPs,at an average density of 26.34 and 4.15 oocysts/L,*** overall removal efficiency was 84.25%,and oocysts were mainly removed(62.01%)by the modified secondary sedimentation *** Cryptosporidium species were identified in the effluent ***,***,and *** were the three most prevalent *** viability assays indicated no reduction of excystation rate during the primary and secondary wastewater treatments(varied in the range of 63.08%–68.50%),but the excystation rate declined to 52.21%in the effluent after ***,the Cryptosporidium oocysts showed higher infection intensity in the cold season(winter and spring)than that in summer and *** influences of environmental temperature on virulence factors of Cryptosporidium were further *** was observed that more extracellular secretory proteins were bound on the oocyst surface and several virulence genes were expressed relatively strongly at low temperatures,both of which could facilitate oocyst adhesion,invasion,and host immune *** research is of considerable interest since it serves as an important step towards more accurate panoramic recognition of Cryptosporidium risk reduction in WWTPs,and especially highlights the potential health risk associated with Cryptosporidium in cold regions/seasons.

关键词： WWTPs Cryptosporidium Occurrence Species Infectivity Low temperature

Microstructure Dictating Performance:Assembly of Graphene-Based Macroscopic Structures

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Accounts of Materials Research 2021年第1期2卷 7-20页

作者： mingxin Li Jie Lian Department of Mechanical Aerospace and Nuclear EngineeringRensselaer Polytechnic InstituteTroyNew York 12180United States

CONSPECTUS:A wide range of groundbreaking advancements in electronics,photonics,nanocomposites,etc.,have been achieved in the past decades due to the favorable attributes of single-layer graphene,including its record-breaking thermal conductivity,charge carrier mobility,fracture strength,and Young’s ***,the realization of the potentials of macroscale graphene assemblies has remained *** difficulties mainly lie within manipulating graphene sheets into an orderly intermolecular orientation and controlling the macroscopic ordering of the graphitic *** the formation of graphene macroscopic structures and eliminating defects on both the nano-and microscales meanwhile optimizing performance is no easy *** address these microstructural issues in macroscopic graphene assemblies,multiple chemical,thermal,and mechanical approaches have been developed with a goal of overall performance ***,in this Account we provide a brief review of our contributions in the microstructure engineering of macroscale graphene assemblies with the focus on graphene fibers(GFs),graphene papers(GPs),and other graphene-based assemblies with graphene oxide(GO)colloids as *** upon the developments in wet chemistry on assembling individual GO sheets into macroscopic structures,we successfully intercalated large GO sheets with small GO sheets,which increased compactness for wet-spun GFs without disturbing the sheet orientation and alignment of the large GO *** GO compactness during wet assembly allows for the increase of thermal and electrical conductivities as well as the mechanical strength of GFs at a single stroke.A high degree of alignment of graphene sheets with abundant sp2 carbon atoms is also necessary for achieving high thermal and electrical conductivities in graphene *** control of GO sheet alignment and orientation during the wet-spinning assembly is demonstrated through the shape and size

关键词： crystallite spinning breaking

Quick Evaluation of Present-Day Low-Total Organic Carbon Carbonate Source Rocks from Rock-Eval Data: Middle–Upper Ordovician in the Tabei Uplift, Tarim Basin

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Acta Geologica Sinica(English Edition) 2018年第4期92卷 1558-1573页

作者： CHEN Junqing pang Xiongqi YANG Haljun pang Hong pang Bo State Key Laboratory of Petroleum Resources and Prospecting China university of Petroteurn Beijing 102249 China College of Geosciences China University of Petroleum Beijing 102249 China Geological Survey of Canada Natural Resources Canada Calgary T2L 2A 7 Canada Research Institute of Petroleum Exploration and Development PetroChina Tarim Oilfield Company Korla 841000 China

Previous studies have postulated the contribution of present-day low-total organic carbon （TOC） marine carbonate source rocks to oil accumulations in the Tabei Uplift, Tarim Basin, China. However, not all present-day low-TOC carbonates have generated and expelled hydrocarbons; therefore, to distinguish the source rocks that have already expelled sufficient hydrocarbons from those not expelled hydrocarbons, is crucial in source rock evaluation and resource assessment in the Tabei Uplift. Mass balance can be used to identify modern low-TOC carbonates resulting from hydrocarbon expulsion. However, the process is quite complicated, requiring many parameters and coefficients and thus also a massive data source. In this paper, we provide a quick and cost effective method for identifying carbonate source rock with present-day low TOC, using widely available Rock-Eval data. First, we identify present-day low-TOC carbonate source rocks in typical wells according to the mass balance approach. Second, we build an optimal model to evaluate source rocks from the analysis of the rocks＇ characteristics and their influencing factors, reported as positive or negative values of a dimensionless index of Rock-Eval data （IR）. Positive IR corresponds to those samples which have expelled hydrocarbons. The optimal model optimizes complicated calculations and simulation processes; thus it could be widely applicable and competitive in the evaluation of present-day low TOC carbonates. By applying the model to the Rock-Eval dataset of the Tabei Uplift, we identify present-day iow-TOC carbonate source rocks and primarily evaluate the contribution equivalent of 11.87×10^9 t oil.

关键词： present-day low-TOC carbonate source rocks quick evaluation model Rock-Eval TabeiUplift

New field of cryptography: DNA cryptography

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Chinese Science Bulletin 2006年第12期51卷 1413-1420页

作者： XIAO Guozhen LU mingxin QIN Lei LAI Xuejia National Key Lab of ISN Xidian University Xi'an 710071 China Queen's University Cancer Research Institute 10 Stuart St. Kingston ON K7L3N6 Canada Department of Computer Science & Engineer Shanghai JiaoTong University Shanghai 200030 China

DNA cryptography is a new born cryp- tographic field emerged with the research of DNA computing, in which DNA is used as information car- rier and the modern biological technology is used as implementation tool. The vast parallelism and ex- traordinary information density inherent in DNA molecules are explored for cryptographic purposes such as encryption, authentication, signature, and so on. In this paper, we briefly introduce the biological background of DNA cryptography and the principle of DNA computing, summarize the progress of DNA cryptographic research and several key problems, discuss the trend of DNA cryptography, and compare the status, security and application fields of DNA cryptography with those of traditional cryptography and quantum cryptography. It is pointed out that all the three kinds of cryptography have their own ad- vantages and disadvantages and complement each other in future practical application. The current main difficulties of DNA cryptography are the absence of effective secure theory and simple realizable method. The main goal of the research of DNA cryptography is exploring characteristics of DNA molecule and reac- tion, establishing corresponding theories, discovering possible development directions, searching for sim- ple methods of realizing DNA cryptography, and lay- ing the basis for future development.

关键词：密码术 DNA计算 DNA密码信息载体生物技术