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Variability of turbulence dispersion characteristics during heavy haze process: A case study in Beijing

Journal of Environmental Sciences 2023年第2期124卷 440-450页

作者： Lei Liu yu Shi Zhe Zhang Fei Hu LAPC Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The turbulent standard deviations and the turbulent third-order and fourth-order moments are the key turbulence dispersion parameters in Lagrangian dispersion ***,the characteristics of these parameters under heavy haze conditions in urban areas have not been fully investigated,and the commonly used similarity relations of these parameters in modelswere based on observations in highly flat and sparsely populated *** this paper,the vertical profiles of these parameters and their local similarity relations under heavy haze conditions in the wintertime of Beijing have been analyzed by using data collected at a 325-m meteorological *** heavy haze process has been divided into three stages:transport stage(TS),cumulative stage(CS),and dispersion stage(DS).Results show that the turbulent dispersion parameters behave differently during three *** the TS and DS,the maxima appear in the profiles of the turbulent standard deviations above the urban canopy;in the CS,the turbulent standard deviation are almost constant with *** analysis of the third and fourth order moments shows that the wind velocities above the urban canopy in the TS deviate from the Gaussian distribution more significantly than those in the CS and *** local similarity relations of the turbulent dispersion parameters in the TS,especially for the longitudinal wind components,are normally different from those in the CS and ***,different from the common assumptions in Lagrangian models,the turbulence dispersion in horizontal directions is anisotropic and should be parameterized by multiple similarity relations under heavy haze conditions.

关键词： Heavy haze Turbulence dispersion Local similarity Lagrangian model

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Mineral Transition of Calcium Aluminate Clinker during High-Temperature Sintering with Low-lime Dosage

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Journal of Materials Science & Technology 2015年第12期31卷 1244-1250页

作者： Di Zhang Xiaolin Pan Haiyan yu yuchun Zhai School of Materials and Metallurgy Northeastern University

The mineral transition mechanism and physicochemical property of calcium aluminate clinker sintered at 1350 ℃ were systematically studied using analytical reagent α-Al 2O 3,CaCO 3 and SiO 2 when the molar ratio of CaO to Al 2O 3 is *** results show that the formation of Ca 2SiO 4 accelerates the diffusion of CaO and Al 2O 3,which promotes the formation of CaAl 2O 4 determined by dilatometer,X-ray diffraction,Fourier transform infrared spectroscopy and scanning electron microscopy *** 4O 7,Ca 3Al 2O 6,Ca 3SiO 5 and Ca 2Al 2SiO 7 only exist in the initial stage of reactions,the amounts of which decrease with the increase of sintering *** 3Al 2O 6 and Ca 12Al 14O 33 react with Al 2O 3 and CaAl 4O 7 to form CaAl 2O 4,while Ca 2Al 2SiO 7 reacts with CaO and Ca 12Al 14O 33 to form Ca 2SiO 4 and CaAl 2O *** sintered clinker contains CaAl 2O 4 and γ-Ca 2SiO 4 as well as some Ca 12Al 14O 33 when the sintering duration is longer than 1.0 *** differential scanning calorimetry results reveal that Ca 2SiO 4,Ca 2Al 2SiO 7 and CaAl 2O 4 are formed at985 ℃,1045℃ and 1339 ℃,*** the sintering duration contributes to the transition of β-Ca 2SiO 4 to γ-Ca 2SiO 4,which improves the pulverization and alumina leaching property of the sintered clinker.

关键词： Sintering Pulverization Mineral Calcium aluminates Microstructure

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Role of the Anterior Cingulate Cortex in Translational Pain Research

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Neuroscience Bulletin 2021年第3期37卷 405-422页

作者： Xiao Xiao Ming Ding yu-Qiu Zhang Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence Ministry of EducationInstitute of Science and Technology for Brain-Inspired IntelligenceBehavioral and Cognitive Neuroscience CenterFudan UniversityShanghai 200433China State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science Department of Translational NeuroscienceJing’an District Centre Hospital of ShanghaiInstitutes of Brain ScienceInstitute of Integrative MedicineFudan UniversityShanghai 200032China

As the most common symptomatic reason to seek medical consultation,pain is a complex experience that has been classified into different categories and *** pain processing,noxious stimuli may activate the anterior cingulate cortex(ACC).But the function of ACC in the different pain conditions is not well *** this review,we elaborate the commonalities and differences from accumulated evidence by a variety of pain assays for physiological pain and pathological pain including inflammatory pain,neuropathic pain,and cancer pain in the ACC,and discuss the cellular receptors and signaling molecules from animal *** further summarize the ACC as a new central neuromodulation target for invasive and non-invasive stimulation techniques in clinical pain *** comprehensive understanding of pain processing in the ACC may lead to bridging the gap in translational research between basic and clinical studies and to develop new therapies.

关键词： Anterior cingulate cortex Deep brain stimulation Transcranial magnetic stimulation Transcranial direct current stimulation Pathological pain Inflammatory pain Neuropathic pain Cancer pain

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Accommodation of curtailed wind power by electric water heaters based on a new hybrid prediction approach

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Journal of Modern Power Systems and Clean Energy 2019年第3期7卷 525-537页

作者： Yang yu Zengqiang MI Xiaoming ZHENG Da CHANG State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBaoding071003China Hebei Key Laboratory of Distributed Energy Storage and Micro-grid North China Electric Power UniversityBaoding071003China

Wind power curtailment is of great importance with the increase of large-scale wind power connected to the grid. A new concept of redundant wind power accommodated by dispatching electric water heaters(EWHs) is developed in the paper. Precise predictions of wind power and EWHs load power are the basis for this work. A hybrid multi-kernel prediction approach integrating an adaptive fruit fly optimization algorithm(AFOA)and multi-kernel relevance vector machine(MKRVM) is proposed to deal with the sample distribution of multisource heterogeneous features uncovered by an energy entropy method, where AFOA is used to determine the kernel parameters in MKRVM adaptively and avoid the arbitrariness. For the large computation of the prediction approach, parallel computation based on the Hadoop cluster is used to accelerate the calculation. Then, an economic dispatching model for accommodating wind power is built taking into account the penalty of curtailed wind power and the operation cost of EWHs. The proposedscheme is implemented in an intelligent residential *** results show that the optimization performance of the hybrid prediction approach is superior to those of four usual optimization algorithms in this case. Regular or orderly scheduling of EWHs enables accommodation of superfluous wind power and reduces dispatch cost.

关键词： Wind power curtailment Electric water heaters(EWH) Dispatching model Relevance vector machine Prediction model

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Low-carbon transition of iron and steel industry in China:Carbon intensity, economic growth and policy intervention

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Journal of Environmental Sciences 2015年第2期27卷 137-147页

作者： Bing yu Xiao Li yuanbo Qiao Lei Shi State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University School of Economics and Management Tsinghua University

As the biggest iron and steel producer in the world and one of the highest CO2 emission sectors, China’s iron and steel industry is undergoing a low-carbon transition accompanied by remarkable technological progress and investment adjustment, in response to the macroeconomic climate and policy intervention. Many drivers of the CO2 emissions of the iron and steel industry have been explored, but the relationships between CO2 abatement,investment and technological expenditure, and their connections with the economic growth and governmental policies in China, have not been conjointly and empirically examined. We proposed a concise conceptual model and an econometric model to investigate this crucial question. The results of regression, Granger causality test and impulse response analysis indicated that technological expenditure can significantly reduce CO2 emissions, and that investment expansion showed a negative impact on CO2 emission reduction. It was also argued with empirical evidence that a good economic situation favored CO2 abatement in China’s iron and steel industry, while achieving CO2 emission reduction in this industrial sector did not necessarily threaten economic *** shed light on the dispute over balancing emission cutting and economic *** the policy aspects, the year 2000 was found to be an important turning point for policy evolution and the development of the iron and steel industry in China. The subsequent command and control policies had a significant, positive effect on CO2 abatement.

关键词： CO2emission reduction Iron and steel industry Economic growth China Vector autoregression(VAR)

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A consistency improving method in the analytic hierarchy process based on directed circuit analysis

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Journal of Systems Engineering and Electronics 2019年第6期30卷 1160-1181页

作者： WU Shihui LIU Xiaodong LI Zhengxin ZHOU yu Equipment Management and UAV Engineering College Air force Engineering University

Test of consistency is critical for the analytic hierarchy process(AHP) methodology. When a pairwise comparison matrix(PCM) fails the consistency test, the decision maker(DM) needs to make revisions. The state of the art focuses on changing a single entry or creating a new matrix based on the original inconsistent matrix so that the modified matrix can satisfy the consistency requirement. However, we have noticed that the reason that causes inconsistency is not only numerical inconsistency, but also logical inconsistency, which may play a more important role in the whole inconsistency. Therefore, to realize satisfactory consistency, first of all, we should change some entries that form a directed circuit to make the matrix logically consistent, and then adjust other entries within acceptable deviations to make the matrix numerically consistent while preserving most of the original comparison information. In this paper, we firstly present some definitions and theories, based on which two effective methods are provided to identify directed circuits. Four optimization models are proposed to adjust the original inconsistent matrix. Finally, illustrative examples and comparison studies show the effectiveness and feasibility of our method.

关键词： analytic hierarchy process(AHP) pairwise compari son matrix(PCM) logical inconsistency numerical inconsistency directed circuit.

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Instance selection method for improving graph-based semi-supervised learning

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Frontiers of Computer Science 2018年第4期12卷 725-735页

作者： Hai WANG Shao-Bo WANG yu-Feng LI 1 National Key Laboratory for Novel Software Technology Nanjing University Nanjing 210023 China Collaborative Innovation Center of Novel Software Technology and Industrialization Nanjing 210023 China

Graph-based semi-supervised learning is an important semi-supervised learning paradigm. Although graphbased semi-supervised learning methods have been shown to be helpful in various situations, they may adversely affect performance when using unlabeled data. In this paper, we propose a new graph-based semi-supervised learning method based on instance selection in order to reduce the chances of performance degeneration. Our basic idea is that given a set of unlabeled instances, it is not the best approach to exploit all the unlabeled instances; instead, we should exploit the unlabeled instances that are highly likely to help improve the performance, while not taking into account the ones with high risk. We develop both transductive and inductive variants of our method. Experiments on a broad range of data sets show that the chances of performance degeneration of our proposed method are much smaller than those of many state-of-the-art graph-based semi-supervised learning methods.

关键词： graph-based semi-supervised learning performance degeneration instance selection

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Low CO content hydrogen production from oxidative steam reforming of ethanol over CuO-CeO_2 catalysts at low-temperature

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Journal of Energy Chemistry 2013年第6期22卷 861-868页

作者： Xue Han yunbo yu Hong He Jiaojiao Zhao Research Center for Eco-Environmental Sciences Chinese Academy of Sciences

CuO-CeO2 catalysts were prepared by a urea precipitation method for the oxidative steam reforming of ethanol at *** catalytic performance was evaluated and the catalysts were characterized by inductively coupled plasma atomic emission spectroscopy,X-ray diffraction,temperature-programmed reduction,field emission scanning electron microscopy and thermo-gravimetric *** CuOCeO2 catalysts,H2 with low CO content was produced in the whole tested temperature range of 250–450 *** non-noble metal catalyst 20CuCe showed higher H2production rate than 1%Rh/CeO2 catalyst at 300–400 C and the advantage was more obvious after 20 h testing at400 *** results further confirmed that CuO-CeO2 catalysts may be suitable candidates for low temperature hydrogen production from ethanol.

关键词： CuO-CeO2 catalyst hydrogen production oxidative steam reforming low-temperature

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Methane activation by[LnO]^(+):the 4f orbital matters

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Science China Chemistry 2024年第1期67卷 330-335页

作者： Bowei yuan Jingxiang Zou Mincheng yu Shaodong Zhou College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang UniversityHangzhou 310027China Zhejiang Provincial Innovation Center of Advanced Chemicals Technology Institute of Zhejiang University–QuzhouQuzhou 324000China Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

Gas-phase reactions of[LnO]^(+)with methane have been studied by using inductively coupled plasma-mass spectrometer(ICP-MS)combined with quantum chemical *** indicate that the[LnO]^(+)(Ln=Sm-Lu)ions are able to activate methane to generate methyl *** particular,[EuO]^(+)and[YbO]^(+)exhibit the highest ***,ab initio computations reveal a novel HAT process operating in the absence of a terminal oxygen radical,as mediated by[EuO]^(+)and[YbO]^(+).Such a process diverges from previous findings on the methane activation by metal oxide clusters,not only on the electronic pattern during the course of hydrogen transfer,but also on the important role that 4f electrons *** associated electronic origins have been discussed,and the well-designed 4f electron occupation may turn to be a promising approach in constructing lanthanide involved catalysts.

关键词： lanthanide oxides methane activation 4f orbitals quantum chemical calculation ion-molecule reaction

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Engineering self-catabolic DNAzyme nanospheres for synergistic anticancer therapy

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Science China Chemistry 2024年第7期67卷 2412-2422页

作者： yu Chen yu Guo Jiaoli Wang Ruiting Liu Xiaohai Yang Kemin Wang Ying Pu Hui Shi Jin Huang Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringKey Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan ProvinceHunan UniversityChangsha 410082China National Clinical Research Center for Geriatric Disorders Department of GeriatricsXiangya HospitalCentral South UniversityChangsha 410008China

DNAzyme-based gene therapy faces some challenges including cell penetration,activity limitation,and co-delivery ***-assembled DNA nanomedicine has attracted widespread attention due to its many *** is urgent to develop a universal DNA degradation strategy for precise programmable drug ***,we reported a self-catabolic DNAzyme nanospheres(SCNS),which could simultaneously achieve cell penetration,activity enhancement,and co-delivery *** SCNS were assembled through Y-DNA stepwise hybridization with each other,which were then loaded with aptamer(Apt),doxorubicin(Dox),and zinc oxide nanoparticles(ZnO NPs).The acid-triggered dissociation of ZnO NPs leads to the generation of Zn^(2+)ions cofactors for immediately self-catabolic DNAzyme *** the disassembly of the SCNS,three types of anticancer treatments would be activated,which include Zn^(2+)involved reactive oxygen species(ROS),Dox-induced chemotherapy,and DNAzyme-based gene *** experimental results show that the nanoplatform(Apt-SCNS-Dox-ZnO)has a good tumor-killing effect and minimal side *** a smart self-driven drug delivery nanoplatform,it is anticipated to displace extraordinary potential in biomedicine and bioengineering.

关键词： DNAzyme nanosphere ZnO NPs ROS Dox anticancer therapy

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