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Lightweight Deep Learning Models for High-Precision Rice Seedling Segmentation from UAV-Based Multispectral Images

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Plant Phenomics 2023年第4期5卷 876-892页

作者： Panli zhang Xiaobo Sun donghui zhang Yuechao Yang Zhenhua Wang College of Engineering Northeast Agricultural UniversityHarbin 150030China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Key Laboratory of Remote Sensing Information and Imagery Analyzing Technology Beijing Research Institute of Uranium GeologyBeijing 100029China College of Agriculture Northeast Agricultural UniversityHarbin 150030China

Accurate segmentation and detection of rice seedlings is essential for precision agriculture and high-yield ***,current methods suffer from high computational complexity and poor robustness to different rice varieties and *** article proposes 2 Iightweight neural network architectures,LW-Segnet and LW-Unet,for high-precision rice seedling *** networks adopt an encoder-decoderstructure with hybrid lightweight convolutions and spatial pyramid dilated convolutions,achieving accurate segmentation while reducing model *** imagery acquired by unmanned aerial vehicle(UAV)was used to train and test the models covering 3 rice varieties and different planting *** results demonstrate that the proposed LW-Segnet and LW-Unet models achieve higher F1-scores and intersection over union values for seedling detection and row segmentation across varieties,indicating improved segmentation ***,the models exhibit stable performance when handling different varieties and densities,showing strong *** terms of efficiency,the networks have lower graphics processing unit memory usage,complexity,and parameters but faster inference speeds,reflecting higher computational *** particular,the fast speed of LW-Unet indicates potential for real-time *** study presents lightweight yet effective neural network architectures for agricultural *** handling multiple rice varieties and densities with high accuracy,efficiency,and robustness,the models show promise for use in edge devices and UAVs to assist precision farming and crop *** findings provide valuable insights into designing lightweight deep learning models to tackle complex agricultural problems.

关键词： seedling union weight

Design and experiment of high-productivity two-stage vacuum pressure swing adsorption process for carbon capturing from dry flue gas

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Chinese Journal of Chemical Engineering 2022年第3期35卷 378-391页

作者： Xiuxin Yu Bing Liu Yuanhui Shen donghui zhang The Research Center of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

A two-stage vacuum pressure swing adsorption(VPSA)process that coupled kinetically controlled and equilibrium controlled separation process with reflux has been investigated for capturing carbon dioxide from dry flue gas(85%N_(2)/15%CO_(2)).In the first enriching stage,carbon molecular sieve(CMS),which shows kinetic selectivity for CO_(2)/N_(2),is adopted as the adsorbent to remove most N_(2)in feed gas,thereby upgrading CO_(2)and significantly reducing the amount for further *** second stage loads zeolite 13X as adsorbent to purify the CO_(2)-rich flow from the first stage for meeting the requirements of National Energy Technology *** of experiments have been conducted for adsorption isotherms measuring and lab-scale experimental validation as well as *** effect of feed composition on the separation performance of the PSA system was studied experimentally and theoretically *** optimal results achieved 95.1%purity and 92.9%recovery with a high CO_(2)productivity(1.89 mol CO_(2)·h^(-1)·kg^(-1))and an appropriate energy consumption of 1.07 MJ·(kg CO_(2))^(-1).Further analysis has been carried out by simulation for explicating the temperature,pressure,and concentration distribution at cyclic steady state.

关键词： Two-stage VPSA process Binary mixture CO_(2)capture Zeolite 13X Carbon molecular sieve

Enrichment of CO from syngas with Cu（I）Y adsorbent by five-bed VPSA

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Frontiers of Chemical Science and Engineering 2013年第4期7卷 472-481页

作者： Shuna LI Huawei YANG donghui zhang Chemical Engineering Research Center State key laboratory of chemical engineering Tianjin University Tianjin 300072 China

Cu（I）Y adsorbent was prepared by reduction of Cu（II）Y which was prepared by ion exchange between the NaY zeolite and a solution of Cu（II） chloride. The dynamic adsorption capacity of Cu（1）Y for CO was calculated by adsorption breakthrough curve measured on a fixed bed at 30~C and 0.006MPa （g） of CO partial pressure. The calculated CO adsorption capacity was 2.14 mmol/g, 37.5 times as much as that of NaY zeolite. The adsorption breakthrough curve experiment was also simulated with Aspen Adsorption software and the results were approxi- mately consistent with experimental results. Then a five- bed VPSA process for separating CO from syngas on this adsorbent was dynamically simulated with Aspen Adsorp- tion software with the adsorption pressure of 0.68 MPa （g） and the desorption pressure of -0.075MPa （g）. The results showed that CO was enriched from 32.3% to 95.16%-98.12%, and its recovery was 88.47%-99.44%.

关键词： Cu(I)Y adsorbent breakthrough curve deso-rption VPSA simulation

Growing Up with Distant Parents:Socialization and Alienation of“Left-Behind”Children in Rural China

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Frontiers of Education in China 2015年第4期10卷 505-525页

作者： zhang donghui School of Education Renmin University of ChinaBeijing 100872China

An increasing number of left-behind children has emerged in rural China as a result of the large-scale migration of rural farmers to urban cities since the *** the absence of parent(s)from the family,the left-behind children face crises in socialization and their relationships with their parents are threatened by physical *** paper investigates how Chinese left-behind children negotiate the missing roles of parents and how the parent-child relations in such families change over time,through in-depth case studies of two left-behind children with different family backgrounds in rural Henan province.

关键词： left-behind children rural China parent-child relations socialization

Interculturality,Identity,and Power:Experiences of Volunteer Chinese Teachers at Overseas Confucius Institutes

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Frontiers of Education in China 2018年第2期13卷 193-215页

作者： zhang donghui School of Education Renmin University of ChinaBeijing 100872China

With the rapid expansion of Confucius Institutes globally,the Hanban launched a Volunteer Chinese Teachers(VCT)Program with the purpose of selecting a large number of college graduates and graduate students from Chinese universities to fill vacancies for overseas Chinese *** spite of the multitude of students participating in the program,there has been a paucity of research attention on *** do these students,most of whom have never been abroad before,manage their life in their host country and negotiate their new role as a VCT in an overseas Confucius Institute?What are their intercultural experiences as they venture into a new country to serve as a native teacher of Chinese?Based on in-depth interviews with a dozen VCTs teaching in linguistically and culturally different contexts,this study seeks to examine the dynamics of interculturality,identity and power relations involved in their overseas language teaching.

关键词： Volunteer Chinese Teachers(VCT) Confucius Institute intercultural experiences native teachers of Chinese

Unresolved CFD-DEM simulation of adsorption process with different particle shapes in radial flow adsorber

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Particuology 2024年第11期94卷 133-145页

作者： Runye zhang Jie Peng Yaohui Wang Zhongli Tang Wenbin Li donghui zhang The Research Center of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

The design and operation of radial flow adsorber are crucial in large-scale industrial oxygen production,which necessitate accurate prediction of gas-solid transfer *** this work,a developed Computational Fluid Dynamics-Discrete Element Method(CFD-DEM)model combined with the adsorption model is *** developed CFD-DEM model is validated by comparing simulated results with experimental data and empirical ***,the effect of particle packing structure and particle shapes on the dynamic adsorption process are analyzed in *** results reveal the mechanism of particle packing structure affecting axial velocity distribution,showing that uneven distribution of resistance on the outer flow channel side leads to uneven axial velocity distribution in the *** to cylindrical adsorbents,the use of spherical adsorbents results in a more uniform axial velocity distribution,consequently reducing bed pressure *** study holds significant potential for optimizing gas distribution and improving separation efficiency in future industrial applications.

关键词： Vacuum pressure swing adsorption Oxygen production Radial flow adsorber CFD-DEM

Integrated vacuum pressure swing adsorption and Rectisol process for CO_(2) capture from underground coal gasification syngas

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Chinese Journal of Chemical Engineering 2023年第5期57卷 265-279页

作者： Jian Wang Yuanhui Shen donghui zhang Zhongli Tang Wenbin Li The Research Center of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

An integrated vacuum pressure swing adsorption(VPSA) and Rectisol process is proposed for CO_(2) capture from underground coal gasification(UCG) syngas. A ten-bed VPSA process with silica gel adsorbent is firstly designed to pre-separate and capture 74.57% CO_(2) with a CO_(2) purity of 98.35% from UCG syngas(CH_(4)/CO/CO_(2)/H_(2)/N_(2)= 30.77%/6.15%/44.10%/18.46%/0.52%, mole fraction, from Shaar Lake Mine Field,Xinjiang Province, China) with a feed pressure of 3.5 MPa. Subsequently, the Rectisol process is constructed to furtherly remove and capture the residual CO_(2)remained in light product gas from the VPSA process using cryogenic methanol(233.15 K, 100%(mass)) as absorbent. A final purified gas with CO_(2) concentration lower than 3% and a regenerated CO_(2) product with CO_(2) purity higher than 95% were achieved by using the Rectisol process. Comparisons indicate that the energy consumption is deceased from 2.143 MJ·kg^(-1) of the single Rectisol process to 1.008 MJ·kg^(-1) of the integrated VPSA & Rectisol process, which demonstrated that the deployed VPSA was an energy conservation process for CO_(2) capture from UCG syngas. Additionally, the high-value gas(e.g., CH_(4)) loss can be decreased and the effects of key operating parameters on the process performances were detailed.

关键词： Underground coal gasification Vacuum pressure swing adsorption Rectisol process CO_(2)capture Integrated process

Vacuum pressure swing adsorption process for coalbed methane enrichment

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Chinese Journal of Chemical Engineering 2021年第4期34卷 264-280页

作者： Bo Lu Yuanhui Shen Zhongli Tang donghui zhang Gaofei Chen State Key Laboratory of Coal and CBM Co-mining Jincheng 048000China The Research Center of Chemical Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

The enrichment of low concentration coalbed methane using adsorption process with activated carbon adsorbent was studied in this *** isotherms of methane,nitrogen and carbon dioxide on activated carbon were measured by volumetric method,meanwhile a series of breakthrough tests with single component,binary components and three components feed mixture has been performed for exploring dynamic adsorption ***,a rigorous mathematical model of adsorption bed containing mass,energy,and momentum conservation equation as well as dualsite Langmuir model with the Linear driving force model for gassolid phase mass transfer has been proposed for numerical modeling and simulation of fixed bed breakthrough process and vacuum pressure swing adsorption ***,the lumped mass transfer coefficient of methane,nitrogen and carbon dioxide on activated carbon adsorbent has been determined to be 0.3 s^(-1),1.0 s^(-1) and 0.06 s^(-1) by fitting the breakthrough curves using numerical ***,a six bed VPSA process with twelve step cycle sequence has been proposed and investigated for low concentration coalbed methane *** demonstrated that the methane molar fraction in feed mixture ranged from 10%to 50%could be enriched to 32.15%to 88.75%methane in heavy product gas with a methane recovery higher than 83%under the adsorption pressure of 3 bar(1 bar=105 Pa)and desorption pressure of 0.1 *** consumption of this VPSA process was varied from 0.165 k·W·h·m^(-3) CH_(4)to 0.649 k·W·h·m^(-3) CH_(4).Finally,a dualstage VPSA process has been successfully developed to upgrade a low concentration coalbed methane containing 20%methane to a target product gas with methane purity higher than 90%,meanwhile the total methane recovery was up to 98.71%with a total energy consumption of 0.504 k·W·h·m^(-3)CH_(4).

关键词： oalbed methane enrichment VPSA process Activated carbon Numerical modeling

Cultivating Citizens with Confucian Cosmopolitanism:Defining the Purpose of Liberal Arts Education in the Asian Context

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Frontiers of Education in China 2020年第4期15卷 564-587页

作者： Baoyan CHENG donghui zhang College of Education University of Hawai‘i at MānoaHonoluluHI 96822USA School of Education Renmin University of ChinaBeijing 100872China

In contrast to the continued decline of liberal arts education in the US,there has been a revived interest in liberal arts education in Asian countries in recent *** in a comprehensive understanding of the central tenets of liberal arts education in the West,this paper looks into the struggles Asian countries face in their exploration of liberal arts education and provides a direction for Asian countries in their efforts to practice liberal arts *** paper establishes the deep connections between humanistic approaches of the Confucian tradition and liberal arts education by pointing to a common ground for the education of ***,the purpose of liberal arts education,in the East as well as in the West,should be the liberation of human beings from the constraints of ignorance,prejudice and traditional customs and through the cultivation of a cosmopolitan morality that emphasizes unity,solidarity and the fusion of *** universities should contemplate the purpose and value of higher education in the 21st century and tap into the rich resources of Confucianism in order to give its liberal arts education a“soul.”

关键词： liberal arts education Confucianism cosmopolitanism higher education Asia/China