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Total plant performance evaluation based on big data: Visualization analysis of TE process

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Chinese Journal of Chemical Engineering 2018年第8期26卷 1736-1749页

作者： mengyao li Wenli Du Feng Qian Weiming Zhong Key Laboratory of Advanced Control and Optimization for Chemical Processes Ministry of Education East China University of Science and Technology

The performance evaluation of the process industry, which has been a popular topic nowadays, can not only find the weakness and verify the resilience and reliability of the process, but also provide some suggestions to improve the process benefits and efficiency. Nevertheless, the performance assessment principally concentrates upon some parts of the entire system at present, for example the controller assessment. Although some researches focus on the whole process, they aim at discovering the relationships between profit, society, policies and so forth, instead of relations between overall performance and some manipulated variables, that is, the total plant performance. According to the big data of different performance statuses, this paper proposes a hierarchical framework to select some structured logic rules from monitored variables to estimate the current state of the process. The variables related to safety and profits are regarded as key factors to performance evaluation. To better monitor the process state and observe the performance variation trend of the process, a classificationvisualization method based on kernel principal component analysis(KPCA) and self-organizing map(SOM) is established. The dimensions of big data produced by the process are first reduced by KPCA and then the processed data will be mapped into a two-dimensional grid chart by SOM to evaluate the performance status. The monitoring method is applied to the Tennessee Eastman process. Monitoring results indicate that off-line and on-line performance status can be well detected in a two-dimensional diagram.

关键词： Performance evaluation Structured logic rules Hierarchical framework Multidimensional visualization KPCA–SOM

A comparative study of long-time series of global-scale albedo products

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International Journal of Digital Earth 2023年第1期16卷 308-322页

作者： li mengyao liu Qiang Qu Ying College of Global Change and Earth System Science State Key Laboratory of Remote Sensing ScienceBeijing Normal UniversityBeijingPeople’s Republic of China Pengcheng Laboratory ShenzhenPeople’s Republic of China School of Geographical Sciences Northeast Normal UniversityChangchunPeople’s Republic of China

Albedo is a key variable in the study of global or regional earth system ***-quality albedo products are helpful for the accurate analysis and prediction of the Earth’s environment and *** paper analyzes the similarities and differences in several global-scale albedo *** conclusions are as follows:(1)Ignoring the downward radiation weight leads to a maximum deviation of±0.2 in the mean albedo in space and time;(2)Most of the products have good consistency at the global scale,especially after 2000,the consistency in the middle latitudes is better than that in the low latitudes and high latitudes;(3)Although there are obvious inter-annual variations and zonal differences in global mean albedo data from 2000 to 2020,the overall trend is not *** complex spatio-temporal variation of albedo requires high-quality remote sensing products to characterize its ***,existing datasets do not show good agreement in these details,and more efforts are needed in this area.

关键词： Albedo remote sensing assessment spatio-temporal variation

Carbonized Yolk-shell Metal-Organic Frameworks for Electrochemical Conversion of CO_(2) into Ethylene

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Chemical Research in Chinese Universities 2023年第2期39卷 246-252页

作者： WANG Renquan li Tiantian GAO Rui QIN Jiaqi li mengyao GUO Yizheng SONG Yujiang State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalian116024P.R.China

With the excessive consumption of fossil fuels and the massive emission of CO_(2),it has led to a series of environmental crises posing a serious threat to sustainable *** CO_(2) reduction reaction( CO_(2)RR)to ethylene helps solve these serious environmental ***,we report the synthesis of a copper-based electrocatalyst by pyrolysis of yolk-shell structured HKUST-1 with partial substitution of trimesic acid by benzimidazole(nitrogen source).The electrocatalyst exhibits an ethylene Faradic efficiency(FE)of 25.8%and a partial ethylene current density of 23.7 mA/cm^(2),in addition,the electrocatalyst can maintain stable performance during 10 h of electrolysis,which are all better than those of the electrocatalyst without nitrogen *** to electrochemical measurements and X-ray photoelectron spectroscopy(XPS),we propose that the nitrogen dopant plays an effective role in stabilizing Cu(I)species and promoting CO_(2) molecules activation,as well as suppressing the reduction of Cu(I)species during ***,the performance of the electrocatalyst toward CO_(2)RR is studied in a flow *** work provides a new route for the design of Cu-based electrocatalyst toward electrochemical CO_(2) conversion into ethylene.

关键词： CO_(2) Cu MOF Electrocatalyst Nitrogen Ethylene

Effects of Integrated Soil-Crop System Management on Soil Organic Carbon Characteristics in a Primosol in Northeast China

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Pedosphere 2017年第5期27卷 957-967页

作者： ZHANG Jinjing CAO Zhiyuan FENG Guozhong li mengyao li Cuilan GAO Qiang WANG lichun Key Laboratory of Soil Resource Sustainable Utilization for Jilin Province Commodity Grain Bases College of Resource and Environmental ScienceJilin Agricultural University Institute of Agricultural Resources and Environments Jilin Academy of Agricultural Sciences

A synchronous increase in crop productivity, nutrient use efficiency, and soil carbon(C) sequestration is important from the point of view of food security and environmental protection. In recent years, integrated soil-crop system management(ISSM), which uses crop models and advanced nutrient management to redesign cropping systems, has been successfully demonstrated to achieve both high crop productivity and high nutrient use efficiency in China, but the effects of ISSM on soil organic C(SOC) characteristics remain unknown. In this study, the effects of current farmers' practice(FP), high-yielding practice(HY), which maximizes yields without considering costs, and ISSM on the content and chemical composition of SOC were studied in a 4-year(2009–2013) field plot experiment with maize(Zea mays L.) monoculture in an Alluvic Primosol in Northeast China. The ISSM resulted in higher soil total organic C(TOC), water-soluble organic C, easily-oxidizable organic C, particulate organic C, and humic acid C compared with HY and FP in the region. The SOC contents in aggregate size fractions generally followed a similar pattern to TOC. Compared with FP,HY decreased the mean weight diameter, geometric mean diameter, percentage of > 0.25-mm water-stable aggregates, and the stability ratio of water-stable aggregates, and increased the structure-deterioration rate and index of unstable aggregates. The opposite trend was observed between ISSM and HY. Solid-state ^(13)C nuclear magnetic resonance spectra of bulk soil showed that ISSM had higher O-alkyl C and aliphatic C/aromatic C ratio, but lower aromatic C, carbonyl C, and alkyl C/O-alkyl C and hydrophobic C/hydrophilic C ratios than HY and FP. Our results suggest that ISSM improves the quantity and quality of SOC and has a positive effect on soil aggregation and aggregate stability.

关键词： aggregate size fractions maize grain yield nutrient use efficiency soil aggregates solid-state ]3C nuclear magneticresonance

Orderedisorder transition and thermal conductivities of the(NdSmEuGd)_((1-x)/2)Dy_(2x)Zr_(2)O_(7)series

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Journal of Materiomics 2023年第1期9卷 138-147页

作者： mengyao li Chucheng lin Yaran Niu Jimei Zhang Yi Zeng Xuemei Song The State Key Lab of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China Key Laboratory of Inorganic Coating Materials CAS Shanghai Institute of CeramicsChinese Academy of SciencesShanghai200050China

Rare-earth zirconates with pyrochlore and fluorite structures have recently been identified as promising thermal barrier coating materials owing to their low thermal *** this study,six samples with the general formula(NdSmEuGd)_((1-x)/2)Dy_(2x)Zr_(2)O_(7)were synthesized to further reduce the thermal conductivity.X-ray diffraction and Raman spectroscopy showed that the transition from an ordered pyrochlore to a disordered fluorite structure is due to cation and anion *** electron microscopy showed that anion disorder occurred before cation disorder.A modified mass disorder parameter was introduced into this system,which can describe the change in thermal conductivity *** parameter can be a basis for designing more complex materials with lower thermal conductivities.

关键词： Orderedisorder transition Thermal conductivity High entropy Rare-earth zirconates

Diverse terahertz wavefront manipulations empowered by the spatially interleaved metasurfaces

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Science China(Information Sciences) 2023年第3期66卷 230-238页

作者： Jitao li Zhen YUE Jie li Chenglong ZHENG Silei WANG mengyao li Yating ZHANG Yan ZHANG Jianquan YAO School of Precision Instruments and Opto-Electronics Engineering Tianjin University College of Optoelectronic Engineering Chengdu University of Information Technology Department of Physics Capital Normal University

Optical metasurfaces have advanced approaches for manipulating light information in the spatial domain, in which the spatially interleaved metasurfaces demonstrate the ability to manipulate a more complex wavefront of light than metasurfaces without the spatial interleaving. The potential of the spatially interleaved metasurfaces has not been fully exploited. In this paper, we design the spatially interleaved terahertz(THz) metasurfaces based on the ingenious spatial interleaving principles to develop the diverse THz wavefront manipulations. Four functions are performed, including the orbital angular momentum(OAM)superposition of single-frequency vortex beams, the separate vortex focusing of single-frequency dual beams,the different OAM manipulations of bifrequency beams in different planes, and achromatic focusing. The demonstrated functions prove that the spatially interleaved metasurface can manipulate THz wavefront at both single frequency and bifrequency, which traditional metasurfaces cannot. This work paves the way for diverse THz wavefront manipulations.

关键词： terahertz wavefront manipulations metasurfaces spatial interleaving onformation optics

Effects of Enclosure on Grassland Ecological and Economic Benefits in Northern China

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Chinese Geographical Science 2024年第1期34卷 67-78页

作者： HU Bo WEN Qingke XI Fengjiang li mengyao WANG libing REN Yuejuan Aerospace Information Research Institute Chinese Academy of SciencesBeijing100094China University of Chinese Academy of Sciences Beijing100049China Inner Mongolia Remote Sensing Center Co. Ltd.Huhhot010000China Xilinhot the Maodeng pasture Xilinhot026000China China University of Mining and Technology Xuzhou221116China Shanxi Provincial Key Lab of Resources Environment and Disaster MonitoringCoal Geological Geophysical Exploration Surveying&Mapping Institute of Shanxi ProvinceJinzhong030600China

Grasslands in northern China serve the country as both an ecological barrier and a livestock production ***,installing enclosures has been becoming the major grassland restoration measure adopted by many local ***,the effects of restoration on both ecological and production benefits of grassland remain unclear for implemented grassland restoration ***,a representative rangeland in northern China,the Maodeng pasture in Inner Mongolia Autonomous Region was selected as the study area,and remote sensing monitoring analyses were carried out to quantify the ecological benefits and economic benefits from 2015 to *** results showed that:1) in terms of ecological benefits,the grassland area with a grassland coverage rate of more than 60% accounts for 32.3% of the regional area,and 86.4% of its grassland grew significantly better than the same period in2015,showing a significant improvement in grassland *** the average amount of carbon per unit area as the ecological benefit evaluation index,it increased by 27.1% to 32.48Tg C/yr from 2015 to 2021.2) In terms of economic benefits,both theoretical grass production and livestock carrying capacity increased from 2015 to *** to 2015,the theoretical grass production in 2021 increased by 24.8% to 71 900 *** livestock carrying capacity reached 52 100 sheep units in 2021,nearly 11 000 sheep units more than that in *** the study period,multiple economic indicators(on a per capita basis of permanent residents) for the pastoral area of Xilinhot City to which the Maodeng pasture belongs,have grown *** capita total income rose from 29 630 yuan(RMB) in2015 to 62 859 yuan(RMB) in *** on grassland resources to develop the pastoral ecology also broadens the potential economic development ***,the establishment of the reserve and the experiment of implanting an enclosure policy have had a significant and positive impact on Maodeng pasture’s develo

关键词： enclosure grassland ecological benefit economic benefit Maodeng pasture Inner Mongolia northern China

All-silicon chiral metasurfaces and wavefront shaping assisted by interference

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Science China(Physics,Mechanics & Astronomy) 2021年第11期64卷 69-77页

作者： Chenglong Zheng Jie li Jitao li Zhen Yue Silei Wang mengyao li Hongliang Zhao Xuanruo Hao Huaping Zang Yating Zhang Jianquan Yao Key Laboratory of Opto-Electronics Information Technology(Tianjin University) Ministry of EducationSchool of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Chiral metasurfaces have different electromagnetic responses with circularly polarized lights,showing as circular dichroism and optical ***,a novel kind of all-silicon chiral metasurface is proposed by introducing destructive interference between achiral *** maximum value of circular dichroism spectra can reach *** adding an antireflective layer at the side of the silicon substrate,the maximum circular dichroism reaches *** is more,the bandwidth of circular dichroism greater than 0.4 reaches 0.15 *** samples are fabricated to verify the feasibility of this scheme,and the experimental results are in good agreement with the *** addition,the proposed scheme can also be used to generate various interesting functions,such as beam control and vortex *** flexible and efficient implementation solution of chiral metasurface can bring new ideas to the development of chiral devices in the future.

关键词： metasurface chiral terahertz decoupling

Directional design and synthesis of high-yield hollow Fe-MFI zeolite encapsulating ultra-small Fe_(2)O_(3) nanoparticles by using mother liquid

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Nano Research 2021年第11期14卷 4304-4313页

作者： Yi Zhai Fumin Wang Xubin Zhang Guojun Lv Yuzhou Wu Tao Jiang Qing Zhang Mengyue li mengyao li Yongkui liu School of Chemical Engineering and Technology Tianjin UniversityTianjin300350China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang212003China

How to directionally design the hollow zeolite via a green route is of great significance. Here, we successfully synthesized the hollow Fe-silicate-1 encapsulated ultra-small Fe_(2)O_(3) nanoparticles (2.5 nm) with higher yield (85.2%) by mother liquid than traditional dissolution-recrystallization for the first time, which was achieved by precisely regulating the number and distribution of defects in zeolite and cleverly utilizing the TPAOH and nuclei in mother liquor. The effects of synthetic temperature, synthetic period and addition amount of parent zeolite on the formation of hollow zeolite have been investigated and the effect of synthetic conditions on the defects in parent zeolite has been also firstly quantified. The corresponding formation mechanism has been proposed. The abundant inner defects provided by the zeolite synthesized at 130 °C for 1 day and large amount of TPAOH remaining in mother liquid are conducive to the formation of hollow zeolite. Meanwhile, both parent zeolite and nuclei (4-, 5-member rings and structure units) in mother liquid obtained at 130 °C play the crucial roles in enhancing the zeolite yield. Notably, Fe_(2)O_(3) nanoparticles could decompose into small fragments by the interaction with nuclei in mother liquid. Partial ultra-small Fe_(2)O_(3) nanoparticles would be encapsulated in cavity and the rest could be inserted in the zeolite framework, which is significantly different from the conventional dissolution-recrystallization mechanism. The obtained encapsulated catalyst shows the superior catalytic performance and stability in phenol and tetracycline degradation reactions.

关键词： mother liquid hollow zeolite high yield defect sites degradation reaction