[目的]揭示萍乡碳储量时空分布特征,阐明土地地类变化与碳储量之间的关系,为探明区域生态系统碳储量状况提供数据支撑。[方法]利用FLUS(future land use simulation)模型与InVEST(integrated valuation of ecosystem services and trade...[目的]揭示萍乡碳储量时空分布特征,阐明土地地类变化与碳储量之间的关系,为探明区域生态系统碳储量状况提供数据支撑。[方法]利用FLUS(future land use simulation)模型与InVEST(integrated valuation of ecosystem services and trade-offs)模型,预测了2030年萍乡市3种不同情景下(自然发展、耕地保护和生态优先)碳储量值。[结果](1)2010—2020年萍乡市碳储量整体呈下降趋势,共减少1.47×10^(6)t;(2)耕地、建设用地、草地、水体和建设用地面积增加和林地与灌木面积减少,是导致碳储量变化的主要原因;(3)2030年自然发展、耕地保护和生态优先情景下陆地生态系统碳储量分别约为4.906×10^(7),4.919×10^(7),5.038×10^(7)t,其中生态优先情景下碳储量损失最少。[结论]萍乡生态系统碳储量呈下降趋势,主要受耕地与建设用地增大的影响,未来应加强对安源区与经济开发区重点变化区域的监测研究。展开更多
对农村居民点用地进行合理规划对于平衡城乡用地矛盾具有重要意义。以张家界市为例,首先运用地理信息系统(geographic information system,GIS)分析方法分析农村居民点空间分异特征;其次从区位交通、自然环境、社会经济三个方面选取了...对农村居民点用地进行合理规划对于平衡城乡用地矛盾具有重要意义。以张家界市为例,首先运用地理信息系统(geographic information system,GIS)分析方法分析农村居民点空间分异特征;其次从区位交通、自然环境、社会经济三个方面选取了与公路、河流、学校、医院的距离、高程、温度和降水等14个指标,运用未来土地利用模拟(future land-use simulation,FLUS)模型在自然发展情景下预测2025年、2030年和2035年土地利用状况;最后提取2030年农村居民点用地数据,基于地理模拟与优化系统(geographical simulation and optimization systems,GeoSOS)平台运用蚁群优化算法(ant colony optimization,ACO)进行空间布局优化,采用景观格局指数量化分析优化前后变化并给出建议。研究发现:①张家界市农村居民点近几年用地增加但聚集度减小,布局总体表现出“中东部密,西北部疏”的分异特征,破碎化明显,需要进行科学合理规划;②农村居民点的分布密度分别为永定区>慈利县>武陵源区>桑植县,布局模式按基本形态可划分为团状、带状、零散和组团模式;③FLUS模型预测2025年、2030年和2035年农村居民点规模通过精度验证,在2025—2035年间由扩张趋于平稳,局部密度增长但整体密度变化不大,形状与其他类型用地相比较为简单;④优化后农村居民点用地整体布局往地势平坦区域聚集,形态表现为“整体聚集、局部分散”,该研究可为区域农村用地布局规划提供技术支撑。展开更多
A reliable and sensitive competitive real-time fluorescent quantitative immuno-PCR （RTFQ-IPCR） assay using a molecular beacon was developed for the determination of trace fluoranthene （FL） in the environment.Under...A reliable and sensitive competitive real-time fluorescent quantitative immuno-PCR （RTFQ-IPCR） assay using a molecular beacon was developed for the determination of trace fluoranthene （FL） in the environment.Under optimized assay conditions,FL can be determined in the concentration range from 1 fg/mL to 100 ng/mL,with y=0.194x ＋ 7.859,and a correlation coefficient of 0.967 was identified,with a detection limit of 0.6 fg/mL.Environmental water samples were successfully analyzed,recovery was between 90% and 116%,with intra-day relative standard deviation （RSD） of 6.7%-12.8% and inter-day RSD of 8.4%-15.2%.The results obtained from RTFQ-IPCR were confirmed by ELISA,showing good accuracy and suitability to analyze FL in field samples.As a highly sensitive method,the molecular beacon-based RTFQ-IPCR is acceptable and promising for providing reliable test results to make environmental decisions.展开更多
为准确进行西藏年楚河流域未来土地利用模拟,对比分析了FLUS模型(Future Land Use Simulation Model)和PLUS模型(Patch-generating Land Use Simulation Model)在该流域LUCC(土地利用(Land use)/土地覆盖变化(Land cover change))模拟...为准确进行西藏年楚河流域未来土地利用模拟,对比分析了FLUS模型(Future Land Use Simulation Model)和PLUS模型(Patch-generating Land Use Simulation Model)在该流域LUCC(土地利用(Land use)/土地覆盖变化(Land cover change))模拟的结果,并在此基础上开展了研究区2030年的土地利用模拟应用。结果表明:(1)采用本地化参数的FLUS模型获得的模拟结果与真实数据的Kappa系数(0.6350)、FOM系数(0.0800)以及模拟图像的总体精度(0.8240)均优于PLUS模型模拟的结果,表明FLUS模型在研究区具有更好的适用性;(2)依据过去的土地利用变化数据对模型的领域权重和转移矩阵参数进行本地化处理,可提高模拟结果与真实数据的Kappa系数,有助于增强模型在区域的适用性;(3)基于FLUS模型的2030年年楚河流域土地利用模拟结果显示,该区域草地、湿地与水体面积将继续减少,耕地、城市、未利用土地、积雪与冰川将增加,林地变化不大,其中,最主要的土地利用变化由草地变为未利用土地。展开更多
With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control ...With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control the urban sprawl.Reasonable delineation of UGB can inhibit the disorderly spread of urban space and guide the normal development of the city.It is of practical significance for the construction of green urban space.The study utilizes GIS technology to establish a land construction suitability evaluation system for Nankang city,which is experiencing rapid urban expansion,and outlines the preliminary UGB under the future land use simulation(FLUS)model.At the same time,considering the coupled coordination of"Production-Living-Ecological Space",and based on the suitability evaluation,we revised the preliminary UGB by combining the advantages of the patch-generating land use simulation(PLUS)model and the convex hull model to delineate the final UGB.The results show that:1)the comprehensive score of the evaluation of the suitability of the construction of land from high to low shows the distribution of the center of the city to the surrounding circle type spread,the center of the city has the highest suitability score.The results of convex hull model show that the urban expansion type of Nankang is epitaxial.In the future,the urban expansion will mainly occur in the northern part of the city.The PLUS model predicts an increase of 3359.97 hm^(2)of construction land in Nankang by 2035,of which 2022.97 hm^(2)is urban construction land.2)The FLUS model has a prediction accuracy of 86.3%and delineates a preliminary UGB area of 9215.07 hm^(2).3)We used the results of the construction suitability evaluation,PLUS model simulation results,and convex hull model predictions to revise the originally delineated UGB.The final delineated UGB area is 8895.67 hm^(2)and it is capable of meeting the future development of the study area.The results of the delineation can promote sustainable urban development,and the delineation methodology can provide a reference basis for the preparation of territorial spatial planning.展开更多
Background: 1-3, 1-6 β-glucan derived from Baker’s yeast (Saccharomyces cerevisiae) has been widely studied for its immune stimulatory capabilities and safety. Previous studies found β-glucan to have efficacy at re...Background: 1-3, 1-6 β-glucan derived from Baker’s yeast (Saccharomyces cerevisiae) has been widely studied for its immune stimulatory capabilities and safety. Previous studies found β-glucan to have efficacy at reducing incidence of URTIs as well as being a low risk for negative side effects. The current study aimed to examine the effects of yeast β-glucan (Angel Yeast) on cold and flu incidences and symptoms in healthy adults. Methods: Two hundred and thirty-one males and females aged 18 to 65 years old supplemented with either β-glucan or a placebo for 3-months. Participants completed a general health questionnaire every 4 weeks and in addition, if participants experienced any cold or flu symptoms, these were recorded daily (along with severity) until resolved or up to 2 weeks. Results: Supplementation with β-glucan reduced the self-reported severity of sore throats and improved sleep quality compared to the placebo group. Conclusions: Yeast β-glucan supplementation appears to be able to help reduce certain symptoms experienced during a cold or flu episode and is safe and well tolerated.展开更多
DFT-B3LYP/6-311G＊＊ method has been used to optimize molecular geometric structures of 527 polychlorinated fluoranthene（PCFRT） congeners and calculate their thermo-dynamic properties in the ideal gas state,such as ...DFT-B3LYP/6-311G＊＊ method has been used to optimize molecular geometric structures of 527 polychlorinated fluoranthene（PCFRT） congeners and calculate their thermo-dynamic properties in the ideal gas state,such as heat capacity at constant volume（Cv）,entropy（S）,standard enthalpy of formation（ΔfH） and standard Gibbs free energy of formation（ΔfG）.The relations of Cv,S,ΔfH and ΔfG with the number and position of chlorine atoms have also been explored,from which the relative stability of PCFRT congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation（Δr,fG）.It was found that some of the PCFRT isomers are in a nonplanar configuration and there are intramolecular Cl…Cl weak interactions in some of the isomers.With increasing the number of chlorine atoms,the values of ΔfH and ΔfG of the most stable PCFRT isomers decrease initially and then increase.The values of ΔfH and ΔfG of PCFRT congeners with the same number of chlorine atoms show a strong dependence on the positions of chlorine atoms.The relative thermodynamic stability of PCFRT isomers is determined mainly by intramolecular adjacent Cl…Cl nuclear repulsive interaction between Cl atoms at two different six-membered rings.Most PCFRT congeners are easier to form thermodynamically than their parent compound.展开更多
合理的土地利用计划对避免高碳排放有着重要意义,进行低碳经济视角下的土地利用优化模拟有利于绿色发展和土地资源科学配置。以北京市为例,将兴趣点(point of interest,POI)数据纳入FLUS模型的BP-ANN算法模块中对其进行改进,利用2010年...合理的土地利用计划对避免高碳排放有着重要意义,进行低碳经济视角下的土地利用优化模拟有利于绿色发展和土地资源科学配置。以北京市为例,将兴趣点(point of interest,POI)数据纳入FLUS模型的BP-ANN算法模块中对其进行改进,利用2010年和2020年2期土地利用数据对改进模型的模拟精度进行对比验证。在此基础上,耦合Markov法及理想点法,对研究区2030年自然演变情景及低碳经济情景下的土地数量结构和空间布局进行模拟分析。研究结果表明:①引入POI数据的FLUS模型在模拟2020年土地利用时,Kappa系数提高4.85%、总体精度提高3.42%,改进模型有利于提高模拟精度;②经模拟验证,在自然演变情景中,碳排放量增加7.70%,建设用地面积增长7.68%,耕地、草地面积持续减退;③在低碳经济情景中,与自然演变情景相比,碳排放量减少198.49万t,建设用地持续扩张的趋势得到遏制,浅山区草地被占用的现象得到缓解,北部林地面积增长明显。研究说明了土地利用模型的模拟精度随城市发展元素的变化而变化,纳入POI数据可以为土地规划提供更好的决策支持,低碳经济导向的土地结构调整及空间布局优化,可以为区域土地合理利用和规划布局提供参考。展开更多
文摘[目的]揭示萍乡碳储量时空分布特征,阐明土地地类变化与碳储量之间的关系,为探明区域生态系统碳储量状况提供数据支撑。[方法]利用FLUS(future land use simulation)模型与InVEST(integrated valuation of ecosystem services and trade-offs)模型,预测了2030年萍乡市3种不同情景下(自然发展、耕地保护和生态优先)碳储量值。[结果](1)2010—2020年萍乡市碳储量整体呈下降趋势,共减少1.47×10^(6)t;(2)耕地、建设用地、草地、水体和建设用地面积增加和林地与灌木面积减少,是导致碳储量变化的主要原因;(3)2030年自然发展、耕地保护和生态优先情景下陆地生态系统碳储量分别约为4.906×10^(7),4.919×10^(7),5.038×10^(7)t,其中生态优先情景下碳储量损失最少。[结论]萍乡生态系统碳储量呈下降趋势,主要受耕地与建设用地增大的影响,未来应加强对安源区与经济开发区重点变化区域的监测研究。
文摘依托数学模型和情景模拟,形成弹性的土地利用优化配置方案,对促进生态脆弱农区生态、农业和经济用地协调发展具有重要意义。以河套灌区乌兰布和灌域为例,采用MSPA(morphological spatial pattern analysis)和斑块重要性指数识别和提取生态源地,耦合NSGA-Ⅲ(non-dominated sorting genetic algorithmⅢ)和FLUS(future land use simulation)模型,基于4种情景模拟形成具有弹性的生态脆弱农区土地利用优化配置方案。结果表明:基于NSGA-Ⅲ可以快速形成研究区多目标下的Pareto解集,且解集内的各目标效益均优于2020年土地利用效益值。生态安全优先发展、粮食生产优先发展和经济优先发展情景存在其他两项目标效益提升不明显的情况。相对来说,最小土地利用变化条件下的均衡效益发展情景可在土地利用变化幅度最小的情况下,达到更高、更均衡的综合效益。制订土地利用优化配置方案时,在参考各情景土地利用优化配置布局的基础上识别土地利用协调冲突区,有助于形成弹性的土地利用优化配置方案,以适应区域可能发生的内外部经济政策环境变化。
基金support by the Scienceand Technology Commission of Shanghai Municipality in China (Key Project of Fundamental Research) (No.09JC1407600)the Science and Technology Commission of Shanghai Municipality in China (Key Project of theScience and Technology Research) (No. 09231202805)the Shanghai Leading Academic Discipline Project(No. B604)
文摘A reliable and sensitive competitive real-time fluorescent quantitative immuno-PCR （RTFQ-IPCR） assay using a molecular beacon was developed for the determination of trace fluoranthene （FL） in the environment.Under optimized assay conditions,FL can be determined in the concentration range from 1 fg/mL to 100 ng/mL,with y=0.194x ＋ 7.859,and a correlation coefficient of 0.967 was identified,with a detection limit of 0.6 fg/mL.Environmental water samples were successfully analyzed,recovery was between 90% and 116%,with intra-day relative standard deviation （RSD） of 6.7%-12.8% and inter-day RSD of 8.4%-15.2%.The results obtained from RTFQ-IPCR were confirmed by ELISA,showing good accuracy and suitability to analyze FL in field samples.As a highly sensitive method,the molecular beacon-based RTFQ-IPCR is acceptable and promising for providing reliable test results to make environmental decisions.
文摘为准确进行西藏年楚河流域未来土地利用模拟,对比分析了FLUS模型(Future Land Use Simulation Model)和PLUS模型(Patch-generating Land Use Simulation Model)在该流域LUCC(土地利用(Land use)/土地覆盖变化(Land cover change))模拟的结果,并在此基础上开展了研究区2030年的土地利用模拟应用。结果表明:(1)采用本地化参数的FLUS模型获得的模拟结果与真实数据的Kappa系数(0.6350)、FOM系数(0.0800)以及模拟图像的总体精度(0.8240)均优于PLUS模型模拟的结果,表明FLUS模型在研究区具有更好的适用性;(2)依据过去的土地利用变化数据对模型的领域权重和转移矩阵参数进行本地化处理,可提高模拟结果与真实数据的Kappa系数,有助于增强模型在区域的适用性;(3)基于FLUS模型的2030年年楚河流域土地利用模拟结果显示,该区域草地、湿地与水体面积将继续减少,耕地、城市、未利用土地、积雪与冰川将增加,林地变化不大,其中,最主要的土地利用变化由草地变为未利用土地。
基金supported by the Humanities and Social Sciences Program of Jiangxi Universities(Grant No.GL21129)the Graduate Student Innovation Fund Program of Gannan Normal University(Grant No.YCX23A043)the Open Subject of Geography Discipline Construction of Gannan Normal University(Grant No.200084).
文摘With rapid economic development,the size of urban land in China is expanding dramatically.The Urban Growth Boundary(UGB)is an expandable spatial boundary for urban construction in a certain period in order to control the urban sprawl.Reasonable delineation of UGB can inhibit the disorderly spread of urban space and guide the normal development of the city.It is of practical significance for the construction of green urban space.The study utilizes GIS technology to establish a land construction suitability evaluation system for Nankang city,which is experiencing rapid urban expansion,and outlines the preliminary UGB under the future land use simulation(FLUS)model.At the same time,considering the coupled coordination of"Production-Living-Ecological Space",and based on the suitability evaluation,we revised the preliminary UGB by combining the advantages of the patch-generating land use simulation(PLUS)model and the convex hull model to delineate the final UGB.The results show that:1)the comprehensive score of the evaluation of the suitability of the construction of land from high to low shows the distribution of the center of the city to the surrounding circle type spread,the center of the city has the highest suitability score.The results of convex hull model show that the urban expansion type of Nankang is epitaxial.In the future,the urban expansion will mainly occur in the northern part of the city.The PLUS model predicts an increase of 3359.97 hm^(2)of construction land in Nankang by 2035,of which 2022.97 hm^(2)is urban construction land.2)The FLUS model has a prediction accuracy of 86.3%and delineates a preliminary UGB area of 9215.07 hm^(2).3)We used the results of the construction suitability evaluation,PLUS model simulation results,and convex hull model predictions to revise the originally delineated UGB.The final delineated UGB area is 8895.67 hm^(2)and it is capable of meeting the future development of the study area.The results of the delineation can promote sustainable urban development,and the delineation methodology can provide a reference basis for the preparation of territorial spatial planning.
文摘Background: 1-3, 1-6 β-glucan derived from Baker’s yeast (Saccharomyces cerevisiae) has been widely studied for its immune stimulatory capabilities and safety. Previous studies found β-glucan to have efficacy at reducing incidence of URTIs as well as being a low risk for negative side effects. The current study aimed to examine the effects of yeast β-glucan (Angel Yeast) on cold and flu incidences and symptoms in healthy adults. Methods: Two hundred and thirty-one males and females aged 18 to 65 years old supplemented with either β-glucan or a placebo for 3-months. Participants completed a general health questionnaire every 4 weeks and in addition, if participants experienced any cold or flu symptoms, these were recorded daily (along with severity) until resolved or up to 2 weeks. Results: Supplementation with β-glucan reduced the self-reported severity of sore throats and improved sleep quality compared to the placebo group. Conclusions: Yeast β-glucan supplementation appears to be able to help reduce certain symptoms experienced during a cold or flu episode and is safe and well tolerated.
基金Sponsored by Natural Science Fundamental Research Program of Henan Provincial Education Department (No.2009A150022)Young Backbone Teacher Program of Xinyang Normal University
文摘DFT-B3LYP/6-311G＊＊ method has been used to optimize molecular geometric structures of 527 polychlorinated fluoranthene（PCFRT） congeners and calculate their thermo-dynamic properties in the ideal gas state,such as heat capacity at constant volume（Cv）,entropy（S）,standard enthalpy of formation（ΔfH） and standard Gibbs free energy of formation（ΔfG）.The relations of Cv,S,ΔfH and ΔfG with the number and position of chlorine atoms have also been explored,from which the relative stability of PCFRT congeners was theoretically proposed according to the magnitude of the relative standard Gibbs free energy of formation（Δr,fG）.It was found that some of the PCFRT isomers are in a nonplanar configuration and there are intramolecular Cl…Cl weak interactions in some of the isomers.With increasing the number of chlorine atoms,the values of ΔfH and ΔfG of the most stable PCFRT isomers decrease initially and then increase.The values of ΔfH and ΔfG of PCFRT congeners with the same number of chlorine atoms show a strong dependence on the positions of chlorine atoms.The relative thermodynamic stability of PCFRT isomers is determined mainly by intramolecular adjacent Cl…Cl nuclear repulsive interaction between Cl atoms at two different six-membered rings.Most PCFRT congeners are easier to form thermodynamically than their parent compound.
文摘合理的土地利用计划对避免高碳排放有着重要意义,进行低碳经济视角下的土地利用优化模拟有利于绿色发展和土地资源科学配置。以北京市为例,将兴趣点(point of interest,POI)数据纳入FLUS模型的BP-ANN算法模块中对其进行改进,利用2010年和2020年2期土地利用数据对改进模型的模拟精度进行对比验证。在此基础上,耦合Markov法及理想点法,对研究区2030年自然演变情景及低碳经济情景下的土地数量结构和空间布局进行模拟分析。研究结果表明:①引入POI数据的FLUS模型在模拟2020年土地利用时,Kappa系数提高4.85%、总体精度提高3.42%,改进模型有利于提高模拟精度;②经模拟验证,在自然演变情景中,碳排放量增加7.70%,建设用地面积增长7.68%,耕地、草地面积持续减退;③在低碳经济情景中,与自然演变情景相比,碳排放量减少198.49万t,建设用地持续扩张的趋势得到遏制,浅山区草地被占用的现象得到缓解,北部林地面积增长明显。研究说明了土地利用模型的模拟精度随城市发展元素的变化而变化,纳入POI数据可以为土地规划提供更好的决策支持,低碳经济导向的土地结构调整及空间布局优化,可以为区域土地合理利用和规划布局提供参考。
