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Impact of Accumulated Temperature on Wetland Vegetation Area in Poyang Lake

Computers, Materials & Continua 2022年第10期73卷 1915-1926页

作者： Xin Yao Junyu Zhu Hong Zeng Wenzheng Yu hanxiaoya zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China Cold and Arid Regions Environmental and Engineering Research Institute CASLanzhou730000China Faculty of Science The University of Auckland1010New Zealand

Accumulated temperature,which is now widely used in agronomy,is an important ecological factor to the growth of plants,but few relative studies have been found on the vegetation area of floodplain grasslands in Poyang *** research used the classification and regression tree(CART)to classify normalized vegetation area index derived from MODIS LAI(Moderate Resolution Imaging Spectroradiometer Leaf Area Index)images from 2008 to 2014,according to different climate indexes,such as mean daily air temperature(n),accumulated temperature(jw),daily maximum temperature(g),daily minimum temperature(d),accumulative precipitation(j),water level(s)and average water level for 20 days preceding(a).The results showed that:(1)The accumulated temperature and the 20-day average WL(water level)were found to have the greatest impact on variation in wetland vegetation area,and they both dominated the classification process twice;(2)Two classification thresholds of accumulated temperature were 790°C and 1784°C,approximately corresponding to the beginning of April and midMay;(3)790°C could also be used as a threshold to select remote sensing images to analysis the annual variability of vegetation,*** accumulated temperature is lower than 790°C,remote sensing images of similar accumulated temperature rather than similar date should be selected from different years for *** also found that,effects of different hydrological factors on area of floodplain grasslands showed stage characteristics:(1)From January to March,water level changes slowly with less rainfall,as a result,the 20-day average WL which can interpret the hydrologic characteristics smoothly showed significant importance in this stage;(2)While entering April,intense rainfall make accumulative precipitation to be the dominating factor of classification;(3)From late April to mid-May,in condition of accumulative precipitation higher than 405 mm,daily water level is of most importance,because to the flood recessio

关键词： Poyang Lake wetlands MODIS LAI CART model accumulated temperature water level

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Poisson-Gumbel Model for Wind Speed Threshold Estimation of Maximum Wind Speed

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Computers, Materials & Continua 2022年第10期73卷 563-576页

作者： Wenzheng Yu Yang Gao Zhengyu Yuan Xin Yao Mingxuan Zhu hanxiaoya zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China Faculty of Science The University of Auckland1010New Zealand

Poisson-Gumbel joint distribution model uses maximum wind speed corresponding to multiple typhoons to construct sample *** are usually used to filter sample sequences to make them more consistent with Poisson ***,few studies have discussed the threshold setting and its impact on Poisson-Gumbel joint distribution *** this study,a sample sequence based on the data of Qinzhou meteorological station from 2005 to 2018 were *** set 0%,5%,10%,20%and 30%gradient ***,we analyzed the influence of threshold change on the calculation results of maximum wind speed in different return *** results showed that:(1)When the threshold increases,the maximum wind speed of each return period will decrease *** indicates that the length of the sample series may have a positive effect on the return period wind speed calculation in Gumbel and Poisson-Gumbel *** the augment of the threshold increases the average value of the maximum wind speed of the sample sequence,it shortens the length of the sample sequence,resulting in a lower calculated value of the maximum wind ***,this deviation is not *** the common 10%threshold as an example,the maximum wind speed calculation deviation in the 50 a return period is about 1.9%;(2)Theoretically,the threshold is set to make the sample sequence more consistent with Poisson distribution,but this example showed that the effect is worth further *** the overall trend showed that the increase of the threshold can makeχ2 decrease,the correlation coefficient of linear fitting was only *** Qinzhou meteorological station data as an example,theχ2 of 20%threshold was as high as 6.35,meaning that the selected sample sequence was not ideal.

关键词： Poisson-Gumbel threshold maximum wind speed probability distribution return period

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Classification of Desertification on the North Bank of Qinghai Lake

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Computers, Materials & Continua 2022年第7期72卷 695-711页

作者： Wenzheng Yu Xin Yao Li Shao Jing Liu Yanbo Shen hanxiaoya zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China School of Environmental Science&Engineering Nanjing University of Information Science&TechnologyNanjing210044China Public Meteorological Service Center China Meteorological AdministrationBeijing100081China Center for Wind and Solar Energy Resources China Meteorological AdministrationBeijing100081China Faculty of Science The University of Auckland1010New Zealand

In this paper,RS,GIS and GPS technologies are used to interpret the remote sensing images of the north shore of Qinghai Lake from 1987 to 2014 according to the inversion results of vegetation coverage(FVC),albedo,land surface temperature(LST),soil moisture(WET)and other major parameters after image preprocessing,such as radiometric correction,geometric correction and atmospheric *** this basis,the decision tree classification method based on landsat8 remote sensing image is used to classify the desertification land in this area,and the development and change of desertification in this period are *** results show that the fluctuation of desertification land area in this area increased during the study period,but from 2003 to 2014,the land area of mild desertification,moderate desertification and severe desertification landwere respectively decreased 0.92,145.89 and 29.39 km2,while the area of serious desertification land still has a slow increasing *** the driving force of desertification change trend in this area is caused by human factors or global change needs to be further studied.

关键词： Remote sensing Qinghai Lake desertification classification

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Characteristics of Climate Change in the Lake Basin Area of Gangcha County

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Computers, Materials & Continua 2022年第10期73卷 363-379页

作者： Wenzheng Yu Aodi Fu Li Shao Haitao Liu Xin Yao Tianliang Chen hanxiaoya zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China School of Environmental Science&Engineering Nanjing University of Information Science&TechnologyNanjing210044China Faculty of Science The University of Auckland1010New Zealand

This paper mainly was based on the average temperature,precipitation,humidity,and wind direction of Gangcha county from 1960 to *** using wavelet analysis and Mann-Kendall(M-K)mutation analysis,specifically analyzed the climate change characteristics in the lake basin area of Gangcha *** result showed that the climatic change in the lake basin area of Gangcha county is *** average temperature,average minimum temperature,average maximum temperature,and evaporation showed an increasing *** the evaporation in the study area was higher than *** average relative humidity showed a decreasing *** the sunshine and the average wind speed percentage showed a significant decreasing *** the Morelet wavelet,The time series of annual mean temperature,annual evaporation and annual sunshine percentage all have quasi3a and quasi4A periods,and the annual mean precipitation has quasi2–3A,quasi2–5A and quasi2–6A periods,which appear in 1996–2005,1962–1978 and 1978–1996 *** mean annual relative humidity has obvious quasi2–7A and quasi3A time series,which appear from 1960 to 1996,1997 to 2005 and after 2008,*** annual mean wind speed has quasi3–4A and quasi5A time series characteristics,which appear in 1964–1967,1984–1995,after 2009 and 1971–1983,*** Mann-Kendall(M-K)mutation analysis,it is found that the mutations of evaporation and the average speed of wind are *** mutation of evaporation started in 2004,and the mutation of average started in 2003.

关键词： Climate change the qinghai lake Morelet wavelet Mann-Kendall test

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Characteristics of Desertification Change in Lake Basin Area in Gangcha County

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Computers, Materials & Continua 2022年第11期73卷 3771-3793页

作者： Wenzheng Yu Mingxuan Zhu Li Shao Yanbo Shen Haitao Liu Tianliang Chen hanxiaoya zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China Public Meteorological Service Center China Meteorological AdministrationBeijing100081China Center for Wind and Solar Energy Resources China Meteorological AdministrationBeijing100081China Faculty of Science The University of AucklandAuckland1010New Zealand

Qinghai Lake Basin area in Gangcha county is selected as the study area in terms of desertification change features in this *** on the remote sensing(RS)and global positioning system(GPS)technologies,the desertification information range from 1989 to 2014 in the study area is *** the method of the decision tree,the desertification in the research area is been divided into four grades including mild desertification,moderate desertification,severe desertification and serious *** change characteristics of desertification in the study area were analyzed in detail,which showed that the desertification in the study area experienced a process of first development and then a *** rapid development of desertification appears in the 1990s,where about 1101.22 kilometers of desertification area was increased in this *** the twenty-first Century,the desertification is gradually significant recovered and local area exist intensified *** are tendencies of interactive transform in different types of *** tendencies of different degrees of desertification land are rising,and there’re some differences in rising rates,where the expansion rate of moderate desertification is the biggest,increasing by 7.27 kilometers per year.

关键词： Desertification classification desertification expansion rate grass land change the Qinghai Lake

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Evolution of Desertification Types on the North Shore of Qinghai Lake

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Computers, Materials & Continua 2022年第5期71卷 3635-3646页

作者： Wenzheng Yu Jintao Cui Yang Gao Mingxuan Zhu Li Shao Yanbo Shen Xiaozhao zhang Chen Guo hanxiaoya zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China College of Hydrology and Water Resources Hohai UniversityNanjing210098China School of Environmental Science&Engineering Nanjing University of Information Science&TechnologyNanjing210044China Public Meteorological Service Center China Meteorological AdministrationBeijing100081China Center for Wind and Solar Energy Resources China Meteorological AdministrationBeijing100081China China Huaneng Group Co. Ltd.Beijing100036China China Huaneng Group Cleaning Energy Technology Academy Co. Ltd.100081China Faculty of Science The University of Auckland1010New Zealand

Land desertification is a widely concerned ecological environment *** the evolution trend of desertification types is of great significance to prevent and control land *** this study,we applied the decision tree classification method,to study the land area and temporal and spatial change law of different types of desertification in the North Bank of Qinghai Lake area from 1987 to 2014,based on the current land use situation and TM remote sensing image data of Haiyan County,Qinghai Province,The results show that the area of mild desertification land and moderate desertification land in the study area has decreased,while the area of severe desertification land and extreme desertification land has increased significantly in the past 30 *** area of desertification land decreased by 4.02 km2,of which the area of mild and moderate desertification land decreased by 39.73 km2 and 36.8 km2 respectively,and the area of severe and extreme desertification land increased by 32.78 km2 and 39.73 km2 *** for the mutual transformation relationship,the transformation from severe desertification land to extreme desertification land is the main,and the junction of severe desertification land and extreme desertification land is the sensitive area of *** the north shore of Qinghai Lake,the sandy land tends to expand *** research provides reference basis for local land desertification monitoring,and has a great guidance for local effective land desertification and soil and water conservation.

关键词： Qinghai Lake desertification evolution mechanism remote sensing

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Restoration of Wind Speed in Qinzhou, Guangxi during Typhoon Rammasun

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Journal on Big Data 2022年第1期4卷 77-86页

作者： Aodi Fu Mingxuan Zhu Wenzheng Yu Xin Yao hanxiaoya zhang School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing210044China School of Applied Meteorology Nanjing University of Information Science&TechnologyNanjing210044China Faculty of Science the University of AucklandAuckland1010New Zealand

In 2014,Typhoon Rammasun invaded Qinzhou,Guangxi,causing damage to the wind tower sensor at 80 m in *** order to restore the wind speed at 80 m at that time,this paper was based on the hourly average wind speed data of the wind tower and meteorological station from 2017–2019,and constructed the wind speed related model of Meteorological Station and the wind measuring tower in Qinzhou,Moreover,this paper Based on the hourly average wind speed data of Qinzhou Meteorological Station in 2014,Restored the hourly average wind speed of the anemometer tower during Rammasun *** results showed it is significant correlation that the hourly mean wind speed of the wind tower at 80 m and the hourly mean wind speed of meteorological station at 100 m(R2=0.9632),and speed of the wind measuring tower and speed of meteorological station constitutes an equation,This equation is Y=*** hourly average wind speed of the wind tower at 80 m during the 2014 Rammasun Landing was restored using this *** the results in Schedule 4.

关键词： Typhoon Rammasun restoration of wind speed regression analysis

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Preparation of silver nanoparticles through the reduction of straw-extracted lignin and its antibacterial hydrogel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 504-514页

作者： Lou zhang Shuo Li Fu Tang Jingkai zhang Yuetong Kang Hean zhang Lidong Li State Key Laboratory for Advanced Metals and Materials School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Silver nanoparticles(Ag NPs)have attracted attention in the field of biomaterials due to their excellent antibacterial ***,the reducing and stabilizing agents used for the chemical reduction of Ag NPs are usually toxic and may cause water *** this work,Ag NPs(31.2 nm in diameter)were prepared using the extract of straw,an agricultural waste,as the reducing and stabilizing *** analysis revealed that the straw extract contained lignin,the structure of which possesses phenolic hydroxyl and methoxy groups that facilitate the reduction of silver salts into Ag *** surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their *** the prepared Ag NPs were added to the precursor solution of acrylamide,free radical polymerization was triggered without the need for extra heating or light irradiation,resulting in the rapid formation of an Ag NP-polyacrylamide composite *** inhibition zone test proved that the composite hydrogel possessed excellent antibacterial ability due to the presence of Ag *** prepared hydrogel may have potential applications in the fabrication of biomedical materials,such as antibacterial dressings.

关键词： silver nanoparticles hydrogel straw extraction antibacterial

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Depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 335-345页

作者： Feng zhang Chenyang zhang Linlin Wu Wei Sun Hongliang zhang Jianhua Chen Yong Pei Songjiang Li Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization Hunan International Joint Research Center for Efficient and Clean Utilization of Critical Metal Mineral ResourcesSchool of Minerals Processing and BioengineeringCentral South UniversityChangsha 410083China State Key Laboratory of Mineral Processing Beijing General Research Institute of Mining&MetallurgyBeijing 100160China Hunan Provincial Key Laboratory of Micro&Nano Materials Interfaces Science College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China School of Resources Environment and MaterialsGuangxi UniversityNanning 530004China Department of Chemistry Xiangtan UniversityXiangtan 411105China China Railway Resource Group Co.Ltd Beijing 102300China

The depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth ***,the depression mechanism of sulfite ions on sphalerite and Pb^(2+)activated sphalerite in the flotation separation of galena from sphalerite was further systematically investigated with experiments and density functional theory(DFT)*** X-ray photoelectric spectroscopy(XPS)results,DFT calculation results,and frontier molecular orbital analysis indicated that sulfite ions were difficult to be adsorbed on sphalerite surface,suggesting that sulfite ions achieved depression effects on sphalerite through other non-adsorption ***,the oxygen content in the surface of sphalerite treated with sulfite ions in creased,which enhanced the hydrophilicity of the sphalerite and further increased the difference in hydrophilicity between sphalerite and ***,sulfite ions were chelated with lead ions to form PbSO_(3)in *** hydrophilic PbSO_(3)was more easily adsorbed on sphalerite than *** interaction between sulfite ions and lead ions could effectively inhibit the activation of *** addition the UV spectrum showed that after adding sulfite ions,the peak of perxanthate in the sphalerite treated xanthate solution was significantly stronger than that in the galena with xanthate solution,indicating that xanthate interacted more readily with sulfite ions and oxygen mo lecules within the sphalerite system,leading to the formation of ***,sulfite ions hardly depressed the flotation of ga lena and could promote the flotation of galena to some *** study deepened the understanding of the depression mechanism o sulfite ions on sphalerite and Pb^(2+)activated sphalerite.

关键词： sphalerite galena sulfite ion density functional theory depression mechanism

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Glucocorticoid receptor signaling in the brain and its involvement in cognitive function

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Neural Regeneration Research 2025年第9期20卷 2520-2537页

作者： Chonglin Su Taiqi Huang Meiyu zhang Yanyu zhang Yan Zeng Xingxing Chen Brain Science and Advanced Technology Institute Hubei Province Key Laboratory of Occupational Hazard Identification and ControlSchool of MedicineWuhan University of Science and TechnologyWuhanHubei ProvinceChina

The hypothalamic-pituitary-adrenal axis regulates the secretion of glucoco rticoids in response to environmental *** the brain,a nuclear receptor transcription fa ctor,the glucocorticoid recepto r,is an important component of the hypothalamicpituitary-a d renal axis's negative feedback loop and plays a key role in regulating cognitive equilibrium and *** glucoco rticoid receptor influences cognitive processes,including glutamate neurotransmission,calcium signaling,and the activation of brain-derived neurotrophic factor-mediated pathways,through a combination of genomic and non-genomic *** interactions within the central nervous system can alter the expression and activity of the glucocorticoid receptor,there by affecting the hypothalamic-pituitary-a d renal axis and stress-related cognitive *** appropriate level of glucocorticoid receptor expression can improve cognitive function,while excessive glucocorticoid receptors or long-term exposure to glucoco rticoids may lead to cognitive *** with cognitive impairment-associated diseases,such as Alzheimer's disease,aging,depression,Parkinson's disease,Huntington's disease,stroke,and addiction,often present with dysregulation of the hypothalamic-pituitary-adrenal axis and glucocorticoid receptor *** review provides a comprehensive overview of the functions of the glucoco rticoid receptor in the hypothalamic-pituitary-a d renal axis and cognitive *** emphasizes that appropriate glucocorticoid receptor signaling fa cilitates learning and memory,while its dysregulation can lead to cognitive *** provides clues about how glucocorticoid receptor signaling can be targeted to ove rcome cognitive disability-related disorders.

关键词： brain-derived neurotrophic factor calcium signaling glucocorticoid receptor glucocorticoid glutamate transmission hypothalamic-pituitary-adrenal axis long-term potentiation neurocognitive disorders neuroplasticity stress

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