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Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

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Frontiers of Environmental Science & Engineering 2023年第10期17卷 133-145页

作者： Yali Chang Jianwei Cao Wenfeng Song Zhi Wang chenyang xu Mengzhuo Long School of Mechanical Electronic and Information Engineering China University of Mining and TechnologyBeijing 100083China CAS Key Laboratory of Green Process and Engineering National Engineering Research Center of Green Recycling for Strategic Metal ResourcesInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China

This work designed a new CaO-Al_(2)O_(3)-SiO_(2)-SO3 glass for the immobilization of multiple heavy metals found in dechlorinated fly ash having high amounts of calcium and sulfur. Increasing the (CaO + SO3)/SiO_(2) mass ratio (M(CS/S)) from 0.28 to 0.85 was found to lower the proportions of Mn, Ni and Zn in an unstable state, while an M(CS/S) ratio of 0.51 gave the lowest proportions of unstable Cr and Pb. Decreasing the degree of polymerization of the glassy network increased the proportions of Mn, Cr, Ni, Pb and Zn in the carbonate bound state. The leaching out of metals in this state was the primary cause of degradation of Q^(3) structural units in the glassy network. The amount of Mn in the iron-manganese oxide bound state was increased by increasing the number of Q^(2) units in the silicate network. Decreasing the CaO/SiO_(2) mass ratio (M(C/S)) raised the proportions of Mn, Ni and Zn in the unstable state. An M(C/S) value of 0.43 lowered the proportions of unstable Cr and Pb. A principal components analysis determined that the leaching of toxic heavy metals from the glass was primarily related to the proportions of these metals in the unstable state while there were no evident correlations between leaching and the proportions in stable states.

关键词： Dechlorinated fly ash SO_(3) Heavy metal Chemical speciation Glass solidification

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Digital mapping of pesticides bioconcentration by integrating remote sensing techniques and plant uptake model

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International Journal of Digital Earth 2023年第1期16卷 2152-2167页

作者： chenyang xu Shuangqiao Liao Minghao Lin Qian Yue Jizhe Xia School of Agriculture Sun Yat-sen UniversityGuangdongPeople’s Republic of China Modern Agricultural Innovation Center Henan Institute of Sun Yat-sen UniversityZhumadianPeople’s Republic of China Institute of Tropical and Marine Meteorology People’s Republic of China Meteorological AdministrationGuangzhouPeople’s Republic of China Department of Urban Informatics Shenzhen UniversityShenzhenPeople’s Republic of China

Although pesticides have been widely used worldwide to enhance crop yield and product quality,most pesticides are harmful to the environment and human *** absorb pesticides mainly from air and ***,the soil-plant pathway is essential for pesticide *** factor(BCF)has extensively been applied to evaluate potential plant contamination by pesticides from ***,this study developed a simplified plant transpiration-based plant uptake model(PT-model)to estimate plant pesticides’BCF from soil based on plant *** sensing techniques were employed to generate spatiotemporal continuous plant transpiration via *** BCF mapping was achieved by integrating PT-model with Moderate Resolution Imaging Spectroradiometer(MODIS)remotely sensed *** results were compared with a verified model driven by relative humidity and air temperature(RA-model),which has been confirmed byfindings from previous *** estimated BCF was within the boundaries of the RA-model,indicating the simulation’s overall *** this study,the BCF temporal trend estimated by the proposed method agreed with the RA-model assimilating meteorology datasets,while the spatial distribution was partially ***,the proposed method generates the spatiotemporal patterns of pesticide BCF with relatively consistent results supported by previous records andfindings.

关键词： Pesticide bioconcentration factor evapotranspiration plant uptake model remote sensing

RSscore:Reaction superiority learned from reaction mapping hypergraph

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Chinese Journal of Chemical Engineering 2024年第10期74卷 203-215页

作者： chenyang xu Lijuan Guo Kang Zhou Hai Yu Chaoliang Wei Fengqi Fan Lei Zhang State Key Laboratory of Fine Chemicals Frontiers Science Center for Smart Materials Oriented Chemical EngineeringInstitute of Chemical Process Systems EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 116024China PetroChina Lanzhou Lubricating Oil Research&Development Institute Lanzhou 730060China

The selection of chemical reactions is directly related to the quality of synthesis pathways,so a reasonable reaction evaluation metric plays a crucial role in the design and planning of synthesis *** reaction conditions also need to be considered in synthesis pathway design,a reaction metric that combines reaction time,temperature,and yield is required for chemical reactions of different reaction *** this study,a chemical reaction graph descriptor which includes the atom-atom mapping relationship is proposed to effectively describe ***,through pre-training using graph contrastive learning and fine-tuning through supervised learning,we establish a model for generating the probability of reaction superiority(RSscore).Finally,to validate the effectiveness of the current evaluation index,RSscore is applied in two applications,namely reaction evaluation and synthesis routes analysis,which proves that the RSscore provides an important agents-considered evaluation criterion for computer-aided synthesis planning(CASP).

关键词： Computer-aided synthesis planning Neural networks Reaction evaluation indicator Reaction graph Graph contractive learning

Smart Contract Based DDoS Attack Traceability Audit Mechanism in Intelligent IoT

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China Communications 2023年第8期20卷 54-64页

作者： Zhuohao Wang Weiting Zhang Runhu Wang Ying Liu chenyang xu Chengxiao Yu Institute of Scientific and Technical Information of China Beijing 100038China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China

In this paper,we focus on providing data provenance auditing schemes for distributed denial of service(DDoS)defense in intelligent internet of things(IoT).To achieve effective DDoS defense,we introduce a two-layer collaborative blockchain framework to support data ***,using data scattered among intelligent IoT devices,switch gateways self-assemble a layer of blockchain in the local autonomous system(AS),and the main chain with controller participation can be aggregated by its associated layer of blocks once a cycle,to obtain a global security *** optimize the processing delay of the security model,we propose a process of data pre-validation with the goal of ensuring data consistency while satisfying overhead *** the flood of identity spoofing packets,it is difficult to solve the identity consistency of data with traditional detection methods,and accountability cannot be pursued ***,we proposed a Packet Traceback Telemetry(PTT)scheme,based on in-band telemetry,to solve the ***,the PTT scheme is executed on the distributed switch side,the controller to schedule and select routing ***,a tracing probabilistic optimization is embedded into the PTT scheme to accelerate path reconstruction and save device *** results show that the PTT scheme can reconstruct address spoofing packet forward path,reduce the resource consumption compared with existing tracing *** tracing audit method has fine-grained detection and feasible performance.

关键词： smart contract Internet of Things distributed denial of service telemetry audit

Porous monoliths of 3D graphene for electric double-layer supercapacitors

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Carbon Energy 2021年第2期3卷 193-224页

作者： Jinjue Zeng chenyang xu Tian Gao Xiangfen Jiang xue‐Bin Wang National Laboratory of Solid State Microstructures(NLSSM) Jiangsu Key Laboratory of Artificial Functional MaterialsCollaborative Innovation Center of Advanced MicrostructuresCollege of Engineering and Applied SciencesNanjing UniversityNanjingChina WPI Center for Materials Nanoarchitectonics National Institute for Materials Science(NIMS)TsukubaJapan

For delivering the nanoscaled extraordinary characteristics in macroscopical bulk,it is essential to integrate two-dimensional nanosheets into threedimensional(3D)porous monoliths,alternatively called as 3D architectures,3D networks,or *** intersupported structure of porous monolithic 3D graphene(3DG)can prevent aggregation or restacking of graphene individuals,and the interconnected sp^(2) network of 3DG not only can provide the highway for the transport of electron/phonon but also can present continual cavities/channels for mass *** review summarizes the synthesis methodology of 3DG porous monoliths and highlights the application for electric double-layer *** challenges and future prospects about the manufacture and application of 3DG are also discussed.

关键词： 3D graphene electric double-layer capacitor graphene aerogel porous monolith supercapacitor

Specific ion effects on soil aggregate stability and rainfall splash erosion

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International Soil and Water Conservation Research 2022年第4期10卷 557-564页

作者： Jingfang Liu Feinan Hu chenyang xu Wei Du Zhenghong Yu Shiwei Zhao Fenli Zheng State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau College of Natural Resources and EnvironmentNorthwest A&F UniversityYangling712100China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling712100China College of Agricultural Science and Engineering Hohai UniversityNanjing210098China

Soil interparticle forces can pose important effects on soil aggregate stability and rainfall splash ***,these interparticle forces are strongly influenced by specific ion *** this study,we applied three monovalent cations(Li^(+),Na^(+),and K^(+))with various concentrations to investigate the influence of specific ion effects on aggregate stability and splash erosion via pipette and rainfall simulation *** specific ion effects on soil interparticle forces were quantitatively evaluated by introducing cationic non-classical *** results showed that aggregate stability and splash erosion had strong ion *** breaking strength and splash erosion rate at the same salt concentration followed the sequence as Li^(+)>Na^(+)>K^(+).With decreasing salt concentration,the difference in aggregate breaking strength or splash erosion rate between different cation systems increased initially(1–10^(-2)mol L^(–1))and later was nearly invariable(10^(–2)–10^(–4)mol L^(–1)).The experimental results were well quantitatively explained by soil interparticle forces considering cationic non-classical ***,both aggregate breaking strength and splash erosion rate of three cations revealed a strong positive linear relation with net force subjected to cationic non-classical polarization(R^(2)=0.81,R^(2)=0.81).These results demonstrated that different non-classical polarization of cations resulted in different soil interparticle forces,and thus led to differences in aggregate stability and splash *** study provides valuable information to deeply understand the mechanisms of rainfall splash erosion.

关键词： Aggregate breaking Cationic non-classical polarization Soil interparticle forces Splash erosion Surface potential

基于BERT模型自适应的科技项目申报书关键文本抽取方法

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科技通报 2025年第1期41卷 8-14页

作者：徐晨阳李子伦张兆娜杨冬菊中国科学技术信息研究所北京100038 大规模流数据集成与分析技术北京市重点实验室北京100144 北方工业大学数据工程研究院北京100144

科技项目申报书内容涵盖了科技领域主要的研究方向和创新性。为提升科技领域项目文本关键内容的抽取效果,本文提出了一种基于BERT(bidirectional encoder representations from transformers)模型自适应的科技项目申报书关键文本抽取方... 详细信息

科技项目申报书内容涵盖了科技领域主要的研究方向和创新性。为提升科技领域项目文本关键内容的抽取效果,本文提出了一种基于BERT(bidirectional encoder representations from transformers)模型自适应的科技项目申报书关键文本抽取方法。在该方法中,首先进行原始文本的预处理;其次,将BERT和伪标签相结合进行模型训练,并构建自适应阈值确保模型训练最优化;最后,本文将模型工程化,进行实际应用。通过实验对比验证:提出的方法在文本抽取过程中表现出良好的性能,数据标注准确度随着数据规模不断增大而呈现提升;该方法在准确率、精确率、召回率与F1值等方面,均优于模型LSTM+SAT(long short-term memory+short-term memery)和模型BERT+PL(BERT+pseudo label)。

关键词： BERT模型自适应伪标签文本抽取模型训练

Stability of Valuations: Higher Rational Rank

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Peking Mathematical Journal 2018年第1期1卷 1-79页

作者： Chi Li chenyang xu Purdue University West LafayetteUSA Beijing International Center for Mathematical Research BeijingChina

Given a klt singularity x∈(X,D),we show that a quasi-monomial valuation v with a finitely generated associated graded ring is a minimizer of the normalized vol-ume functionvol_((X,D),x),if and only if v induces a degeneration to a K-semistable log Fano cone ***,such a minimizer is unique among all quasi-mono-mial valuations up to *** a consequence,we prove that for a klt singular-ity x∈X on the Gromov-Hausdorff limit of Kähler-Einstein Fano manifolds,the intermediate K-semistable cone associated with its metric tangent cone is uniquely determined by the algebraic structure of x∈X,hence confirming a conjecture by Donaldson-Sun.

关键词： Quasi-monomial valuation Normalized volume K-stability Metric tangent cone

A Survey on the Current Situation of Prehospital First Aid about Knowledge, Belief and Behavior among University Students in Jingzhou

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Open Journal of Applied Sciences 2024年第5期14卷 1251-1261页

作者： Tianyue Zhang Hong Zhou chenyang xu Juan Zhou Department of Medical Health Science Center Yangtze University Jingzhou China

Objective: To understand the current situation of prehospital first aid knowledge, attitude and behavior of university students in Jingzhou City. Methods: A prehospital first aid knowledge questionnaire and the convenience sampling method were used to survey 307 university students in Jingzhou City. Results: The mean score of prehospital first aid knowledge of university students in Jingzhou City was 12.85 ± 2.643, the mean score of attitude was 50.73 ± 4.114, and the mean score of behavior was 39.05 ± 8.898;There was a statistically significant difference in the scores of prehospital first aid knowledge, attitude, and behavior of university students depending on whether or not they had received prehospital first aid training (P P Conclusion: Jingzhou University students have a positive attitude toward pre-hospital first aid, but the knowledge level and behavior are low, which suggests that the government, society and the school should create good conditions to promote the improvement of pre-hospital first aid knowledge and ability.

关键词： Prehospital First Aid University Student Knowledge Attitude Behaviors