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Effects of Coal Rank and High Organic Sulfur on the Structure and Optical Properties of Coal-based Graphene Quantum Dots

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Acta Geologica Sinica(English Edition) 2018年第3期92卷 1218-1230页

作者： TANG Yuegang HUAN Xuan LAN Chunyuan XU Miaoxin college of geoscience and surveying Engineering China University of Mining & Technology (Beijing) Beijing 100083 China

Coal-based graphene quantum dots(GQDs) were successfully produced via a one-step chemical synthesis from six different coal ranks, from which two superhigh organic sulfur(SHOS) coals were selected as natural S-doped carbon sources for the preparation of S-doped GQDs. The effects of coal properties on coal-based GQDs were analyzed by means of high-resolution transmission electron microscopy(HRTEM), X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, X-ray photoelectron spectroscopy(XPS), ultraviolet-visible(UV-Vis) absorption spectroscopy, and fluorescence emission spectra. It was shown that all coal samples can be used to prepare GQDs, which emit bluegreen and blue fluorescence under ultraviolet light. Anthracite-based GQDs have a hexagonal crystal structure without defects, the largest size, and densely arranged carbon rings in their lamellae; the highrank bituminous coal-based GQDs are relatively reduced in size, with their hexagonal crystal structure being only faintly visible; the low-rank bituminous coal-based GQDs are the smallest, with sparse lattice fringes and visible internal defects. As the metamorphism of raw coals increases, the yield decreases and the fluorescence quantum yield(QY) initially increases and then decreases. Additionally, the surface of GQDs that were prepared using high-rank SHOS coal(high-rank bituminous coal) preserves rich sulfur content even after strong oxidation, which effectively adjusts the bandgap and improves the fluorescence QY. Thus, high-rank bituminous coal with SHOS content can be used as a natural S-doped carbon source to prepare S-doped GQDs, extending the clean utilization of low-grade coal.

关键词： coal graphene quantum dots coal rank organic sulfur China

Evolution mechanism and treatment timing of penetrating fissures

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Journal of Mountain Science 2024年第10期21卷 3453-3473页

作者： ZHANG Yanjun YAN Yueguan ZHU Yuanhao DAI Huayang college of Geoscience and surveying Engineering China University of Mining and Technology-BeijingBeijing 100083China

The Inner Mongolia mining area in western China are characterized by the development of numerous penetrating fissures,resulting in severe land *** is significant to reveal the underlying evolution mechanism and identify treatment timing for restoring the ecological *** Guanbanwusu mining subsidence area in Inner Mongolia,China was selected as the research case for this *** evolution mechanism of different penetrating fissures was revealed by field measurement,physical simulation and theoretical *** treatment timing prediction model for the mining subsidence area was established based on the enhanced Weibull time *** results show that the ground fissures are mainly step-type and collapse-type *** breaking form of overlying strata determines their vertical opening and horizontal *** high mining intensity in the western mining area results in a shortened period of dynamic fissure expansion and reduced closure *** damage extent of the overlying strata exhibits zoning characteristics both vertically and *** relative standard deviation of the prediction model is only 3.7%.Concurrently,the prediction model is employed to determine the optimal timing for treatment in the study area,estimated to be 259 ***,once this threshold is reached,the study area undergoes treatment and restoration of its e cological *** study addresses the knowledge gap in this field by highlighting the interconnectedness between rock strata structure and evolution mechanism of penetrating fissures,thereby providing a method for determining the treatment timing in mining subsidence areas.

关键词： Mining subsidence Ecological restoration Fissures Evolution mechanism Prediction model Treatment timing

Impacts of anthropogenic and biophysical factors on ecological land using logistic regression and random forest:A case study in Mentougou District,Beijing,China

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Journal of Mountain Science 2022年第2期19卷 433-445页

作者： TIAN Chao CHENG Lin-lin YIN Ting-ting college of Geoscience and surveying Engineering China University of Mining and Technology(Beijing)Beijing 100083China

Ecological land is an important guarantee to maintain urban ecological security and sustainable *** increasing studies have been brought to ecological land,with few explorations of the relative importance of anthropogenic-natural factors and how they interact to induce the ecological land *** research sought to fill this *** this study,18 factors,including the risk of goaf collapse,fault,prime croplands,were selected from six aspects of topography,geology,climate,accessibility,socio-economic and land control *** regression(LR)and random forest(RF)models were adopted to identify the anthropogenic and biophysical factors on the dynamic change of ecological land of Mentougou in Beijing from 1990 to *** results show that there was a significant increase in ecological land from 1990 to *** increased area of ecological land reached 102.11 km2 with an increased rate of 0.78,the gravity center of ecological land gradually moved to the *** impact of anthropogenic factors on ecological land was greater than that of natural factors,ecological land was mainly driven by proportion of prime cropland,per capita GDP,land urbanization,temperature,per capita rural income,elevation and aspect ***,slope and precipitation were also identified as important predictors for ecological land *** model comparison suggested that RF can better identify the relationship between ecological land and explanatory variables than LR *** on our findings,the implementation of government policies along with anthropogenic factors are the most important variables influencing ecological land change,and the rational planning and allocation of ecological land by Mentougou government are still needed.

关键词： Logistic regression Random forest Ecological land Determinants Dynamic change

Application of Silicon and Selenium in Rice for Reducing Cadmium Stress

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Phyton-International Journal of Experimental Botany 2023年第6期92卷 1873-1886页

作者： Mohammad Reza Boorboori Husen Qiu Jieyun Liu Haiyang Zhang college of Environment and surveying and Mapping Engineering Suzhou UniversitySuzhou234000China

Rice is an essential part of the human diet in most parts of the world;On the other hand,the industrialization of societies has led to pollution of the environment,including heavy metal contamination of soil and water,which negatively affects rice production and ***,finding ways to increase the yield and quality of this strategic crop seems *** studies have been conducted in recent decades to find effective and inexpensive solutions to reduce the adverse effects of heavy metals in rice *** to the negative effect of cadmium pollution on rice quality and yield,the current study aimed to investigate cadmium absorption and transfer mechanisms in rice(from absorption by roots to loading in grains),and its effects on rice morphology,physiology,and biochemistry(such as biomass,nutrient absorption,antioxidant defenses).Also,rice’s natural mechanisms for detoxifying cadmium were *** study also intended to identify the absorption and transfer pathways of silicon and selenium in rice,their roles in improving rice structures,and their antagonistic effects on reducing cadmium stress(absorption,transport,and toxicity of cadmium).

关键词： Oryza sativa L antagonism elements mechanism stress

Tidal modeling based on satellite altimetry observations of TOPEX/ Poseidon, Jason1, Jason2, and Jason3 with high prediction capability: A case study of the Baltic Sea

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Geodesy and Geodynamics 2024年第4期15卷 404-418页

作者： Alireza A.Ardalan Asiyeh Hashemifaraz School of surveying and Geospatial Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran

This research aims to optimize the utilization of long-term sea level data from the TOPEX/Poseidon,Jason1,Jason2,and Jason3 altimetry missions for tidal *** generate a time series of along-track observations and apply a developed method to produce tidal models with specific tidal constituents for each *** tidal modeling methodology follows an iterative process:partitioning sea surface height(SSH)observations into analysis/training and prediction/validation parts and ultimately identi-fying the set of tidal constituents that provide the best predictions at each time series *** study focuses on developing 1256 time series along the altimetry tracks over the Baltic Sea,each with its own set of tidal *** of the developed tidal models against the sSH observations within the prediction/validation part reveals mean absolute error(MAE)values ranging from 0.0334 m to 0.1349 m,with an average MAE of 0.089 *** same validation process is conducted on the FES2014 and EOT20 global tidal models,demonstrating that our tidal model,referred to as BT23(short for Baltic Tide 2023),outperforms both models with an average MAE improvement of 0.0417 m and 0.0346 m,*** addition to providing details on the development of the time series and the tidal modeling procedure,we offer the 1256 along-track time series and their associated tidal models as supplementary *** encourage the satellite altimetry community to utilize these resources for further research and applications.

关键词： Satellitealtimetry Baltic Sea Ocean tide modeling Jason3 Jason2 Jason1 TOPEX/Poseidon EOT20 FES2014

GNSS clock corrections densification at SHAO:from 5 min to 30 s

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Science China(Physics,Mechanics & Astronomy) 2014年第1期57卷 166-175页

作者： CHEN JunPing ZHANG YiZe ZHOU XuHua PEI Xiao WANG JieXian WU Bin Shanghai Astronomical Observatory Chinese Academy of Sciences college of surveying and Geo-Informatics Tongji University

High frequency multi-GNSS zero-difference applications like Precise Orbit Determination （POD） for Low Earth Orbiters （LEO） and high frequency kinematic positioning require corresponding high-rate GNSS clock corrections. The determination of the GNSS clocks in the orbit determination process is time consuming, especially in tile combined GPS/GLONASS pro- cessing. At present, a large number of IGS Analysis Centers （AC） provide clock corrections in 5-rain sampling and only a few ACs provide clocks in 30-s sampling for both GPS and GLONASS. In this paper, an efficient epoch-difference GNSS clock determination algorithm is adopted based on the algorithm used by the Center for Orbit Determination in Europe （CODE）. The clock determination procedure of the GNSS Analysis Center at Shanghai Astronomical Observatory （SHAO） and the algorithm is described in detail. It is shown that the approach greatly speeds up the processing, and the densified 30-s clocks have the same quality as the 5-rain clocks estimated based on a zero-difference solution. Comparing the densified 30-s GNSS clocks provided by SHAO with that of IGS and its ACs, results show that our 30-s GNSS clocks are of the same quality as that of 1GS. Allan deviation also gives the same conclusion. Further validation of the SHAO 30-s clock product is performed in kine- matic PPP and LEO POD. Results indicate that the positions have the same accuracy when using SHAO 30-s GNSS clocks or IGS （and its AC） finals. The robustness of the algorithm and processing approach ensure its extension to provide clocks in 5-s or even higher frequencies. The implementation of the new approach is simple and it could be delivered as a black-box to the current scientific software packages.

关键词： satellite clock corrections GNSS epoch-difference clock densification kinematic precise point positioning

Spatiotemporal dynamics of population density in China using nighttime light and geographic weighted regression method

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International Journal of Digital Earth 2023年第1期16卷 2704-2723页

作者： Wei Guo Jinke Liu Xuesheng Zhao Wei Hou Yunxuan Zhao Yongxing Li Wenbin Sun Deqin Fan college of Geoscience and surveying Engineering China University of Mining and TechnologyBeijingPeople’s Republic of China Chinese Academy of surveying&Mapping BeijingPeople’s Republic of China

The distribution and dynamic changes of regional or national population data with long time series are very important for regional planning,resource allocation,government decision-making,disaster assessment,ecological protection,and other sustainability ***,the existing population datasets such as LandScan and WorldPop all provide data from 2000 with limited time series,while GHS-POP only utilizes land use data with limited *** view of the limited remote sensing images of long time series,it is necessary to combine existing multi-source remote sensing data for population spatialization *** this research,we developed a nighttime light desaturation index(NTLDI).Through the cross-sensor calibration model based on an autoencoder convolutional neural network,the NTLDl was calibrated with the same period Visible Infrared Imaging Radiometer Suite Day/Night Band(VIRS-DNB)***,the geographically weighted regression method is used to determine the population density of China from 1990 to 2020 based on the long time series ***,the change characteristics and the driving factors of China's population spatial distribution are *** large-scale,long-term population spatialization results obtained in this study are of great significance in government planning and decision-making,disaster assessment,resource allocation,and other aspects.

关键词： Nighttime light Population density Geographically weighted regression Population spatialization Driving force analysis

The Mechanisms of Trichoderma Species to Reduce Drought and Salinity Stress in Plants

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Phyton-International Journal of Experimental Botany 2023年第8期92卷 2261-2281页

作者： Mohammad Reza Boorboori Haiyang Zhang college of Environment and surveying and Mapping Engineering Suzhou UniversitySuzhou234000China

Environmental stresses caused by climate change have severely affected agriculture in the present century;Salinity and drought have challenged most forecasts for increased agricultural production in the past few decades,there-fore,different methods that reduce the effect of these stresses on plants have attracted scientists’*** effect of beneﬁcial soil microorganisms on soil health and increasing plants’resistance to stresses is one of the solutions that researchers have paid attention *** study investigated how Trichoderma species can be affected by the molecular and morphophysiological mechanisms of plants and improve their salt and drought *** study also studied the different Trichoderma species’functions to get a better understanding of how they reduce salt and drought ***,theﬁndings of this study provide a clear path for future research to focus on the unknown aspects of Trichoderma species andﬁnd effective ways to boost crop production under environmental stresses.

关键词： Dryness microorganisms molecular morphophysiology plant resistance saline environment

Facility Mapping of University of Lagos

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Journal of Geoscience and Environment Protection 2017年第12期5卷 166-180页

作者： Esther Oluwafunmilayo Makinde Seyi Adewale Adebangbe Babajide Abdulahmeen Erinjogunola Department of surveying and geoinformatics Faculty of Engineering University of Lagos Lagos Nigeria

This paper shows a detailed methodology for creating 2D and 3D visual facility map of the campus. The purpose of this study work is to develop an interactive interface containing the 2 and 3-Dimensional features of all the facilities within the University of Lagos. The spatial attributes of the facilities were collected with the aid of total stations. The most recent Google earth software was used as source of data to produce 2-dimensional facilities of the study area through digitization process. SRTM Digital elevation model image was downloaded from United State Geological Survey website to give the elevation data required for the 3-dimensional representation. All these data were processed with ArcGIS 10.2.1.

关键词： GIS Digital Elevation Model (DEM) 2D Map 3D Map