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Uphill or downhill?Cropland use change and its drivers from the perspective of slope spectrum
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作者 pan sipei LIANG Jiale +1 位作者 CHEN Wanxu PENG Yelin 《Journal of Mountain Science》 SCIE CSCD 2024年第2期484-499,共16页
The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphi... The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphic features is considered as a digital terrain analysis method which reflects the macro-topographic features by using micro-topographic factors.However,pieces of studies have extended the concept of slope spectrum in the field of geoscience to construction land to explore its expansion law,while research on the slope trend of cropland from that perspective remains rare.To address the gap,in virtue of spatial analysis and geographically weighted regression(GWR)model,the cropland use change in the Yangtze River Basin(YRB)from 2000 to 2020 was analyzed and the driving factors were explored from the perspective of slope spectrum.Results showed that the slope spectrum curves of cropland area-frequency in the YRB showed a first upward then a downward trend.The change curve of the slope spectrum of cropland in each province(municipality)exhibited various distribution patterns.Quantitative analysis of morphological parameters of cropland slope spectrum revealed that the further down the YRB,the stronger the flattening characteristics,the more obvious the concentration.The province experienced the greatest downhill cropland climbing(CLC)was Shannxi,while province experienced the highest uphill CLC was Zhejiang.The most common cropland use change type in the YRB was horizontal expansion type.The factors affecting average cropland climbing index(ACCI)were quite stable in different periods,while population density(POP)changed from negative to positive during the study period.This research is of practical significance for the rational utilization of cropland at the watershed scale. 展开更多
关键词 Cropland climbing Land use change Slope spectrum Driving factors Geographically weighted regression Yangtze River Basin
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槲皮素对奈瑟球菌感染脑膜炎大鼠继发内毒素血症的抑制作用及机制研究 被引量:4
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作者 郦铮铮 陈瑾 +2 位作者 潘珍珍 潘思培 张楠 《中国临床药理学与治疗学》 CAS CSCD 2019年第6期658-664,共7页
目的:分析槲皮素对奈瑟球菌感染脑膜炎大鼠继发内毒素血症的抑制作用影响。方法:选取SPF级Wistar雄性大鼠60只,随机数字表法将大鼠分成6组,分别是模型组、正常组、阳性对照组、低剂量槲皮素组、中剂量槲皮素组及高剂量槲皮素组,每组各10... 目的:分析槲皮素对奈瑟球菌感染脑膜炎大鼠继发内毒素血症的抑制作用影响。方法:选取SPF级Wistar雄性大鼠60只,随机数字表法将大鼠分成6组,分别是模型组、正常组、阳性对照组、低剂量槲皮素组、中剂量槲皮素组及高剂量槲皮素组,每组各10只,除正常组大鼠外,其他大鼠制备奈瑟球菌感染脑膜炎模型,造模后阳性对照组灌胃2mL剂量为100mg/L的地塞米松药液,低、中、高剂量槲皮素组灌胃2mL剂量为50、100、200mg/L的槲皮素药液,正常组与模型组大鼠灌胃等剂量生理盐水,各组大鼠给药间隔12h,共给药5次。观察各组大鼠给药12、24、36、48及60h时其存活率状况,同时间隔12h检测大鼠体温一次,ELISA法检测血清IL-6、TNF-α、脂多糖、IL-1β、IL-8含量,Western blot检测p65与IκBα蛋白表达,RT-PCR检测脑组织Toll样受体4(TLR4)mRNA、CD68mRNA相对表达量。结果:造模24h内模型组大鼠全部死亡,模型组大鼠存活率低于正常组,中剂量及高剂量槲皮素组大鼠存活率优于模型组、阳性对照组及低剂量槲皮素组,差异有统计学意义(P<0.05);模型组大鼠血清IL-6、TNF-α、IL-1β及IL-8含量显著高于正常组(P<0.05),其他各给药组血清IL-6、TNF-α、IL-1β及IL-8含量显著低于模型组。其中,中、高剂量槲皮素组大鼠降低显著,和模型组、阳性对照组对比差异有统计学意义(P<0.05)。模型组大鼠IκBα蛋白表达比正常组下降,p65蛋白表达比正常组上升,中、高剂量槲皮素组大鼠IκBα蛋白表达比模型组、阳性对照组上升,p65蛋白比模型组、阳性对照组下降,差异均有统计学意义(P<0.05)。结论:槲皮素可抑制奈瑟球菌感染脑膜炎大鼠机体NF-κB炎症通路,降低血清炎性因子含量,提高大鼠存活率。 展开更多
关键词 细菌性脑膜炎 脑膜炎奈瑟球菌 内毒素血症 炎性因子 槲皮素
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基于文献计量分析的国内外空间规划研究比较 被引量:4
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作者 潘思佩 陈万旭 +1 位作者 梁加乐 李江风 《中国农业资源与区划》 CSCD 北大核心 2023年第2期131-144,共14页
[目的]生态文明背景下,科学制定国土空间规划和完善空间治理体系,对统筹好资源环境保护与空间开发以及经济发展具有重要现实意义。[方法]文章运用文献计量分析和可视化的知识图谱分析方法,以“空间规划”为主题进行文献检索,对2000年以... [目的]生态文明背景下,科学制定国土空间规划和完善空间治理体系,对统筹好资源环境保护与空间开发以及经济发展具有重要现实意义。[方法]文章运用文献计量分析和可视化的知识图谱分析方法,以“空间规划”为主题进行文献检索,对2000年以后国内外有关空间规划的相关期刊文献集进行多角度的可视化分析。[结果](1) 2000—2020年国内外有关空间规划研究的文献量都呈现逐年上升的趋势,但在研究机构之间的合作强度上均有待加强;(2)我国有关空间规划的研究论文发表的期刊虽多,但是发文期刊仍然集中在城市规划领域,国外有关空间规划的论文发表所涉及的期刊类型则更为丰富;(3)共词分析发现,国内外在空间规划研究领域中,某些研究方向的成果,如“多规合一”等,集中在少数研究学者之中;(4)聚类分析发现,国外有关空间规划的研究在2020年之前明显处于大量工具的开发阶段,而我国有关空间规划的研究则处于最初的概念形成转向大量工具开发的过渡阶段;(5)研究前沿辨析发现,国外有关空间规划研究已经延伸到不同的学科,较早考虑到了环境问题,技术问题也得到特别的关注,而中国的研究则呈现明显的时间阶段,所关注的热点问题不断变化,并且缺少不同学科间的交融研究。[结论]中国今后空间规划的研究对象将更为丰富,内涵与外延将得到不断的扩展细化,生态问题既是空间规划研究的重点也是未来研究的趋势。 展开更多
关键词 空间规划 国内外 比较 文献计量 知识图谱
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Land-use planning in China:Past,present,and future
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作者 CHEN Wanxu pan sipei YE Xinyue 《Journal of Geographical Sciences》 SCIE CSCD 2023年第7期1527-1552,共26页
Under the framework of ecological civilisation,the formulation of territorial spatial planning(TSP) and improvement of spatial governance systems are of great practical significance.Since the founding of the People’s... Under the framework of ecological civilisation,the formulation of territorial spatial planning(TSP) and improvement of spatial governance systems are of great practical significance.Since the founding of the People’s Republic of China,land-use planning(LUP) has experienced profound changes,and tremendous research efforts have been made in that field.However,systematic studies on LUP history are scarce.To bridge the existing gap,this study traced back to the emergence of LUP,described its practice stages,and analysed the evolution of its classification system and methods.Further,the three rounds of general LUP practice and the current TSP over the past 40 years of the reform and opening-up have been discussed.The evolution of LUP was found to be closely related to economic development and could be broadly divided into four stages.The development of land-use classification in China has been slow and can be divided into five stages according to the evolution of the land classification system and important historical events.The development of LUP methods can be divided into two stages,before and after 1978.Since the economic reform,China has successively conducted three rounds of general LUP under different institutional and policy backgrounds.Future development should aim to innovate the theories and methods of TSP with Chinese characteristics and promote the study of village planning and the construction of TSP systems to achieve rural revitalisation and ecological civilisation. 展开更多
关键词 land-use planning land-use policy territorial spatial planning sustainable development China
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长江中游城市群交通可达性对生态系统服务供需耦合影响研究 被引量:1
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作者 陈万旭 卞娇娇 +2 位作者 梁加乐 潘思佩 曾源源 《Journal of Geographical Sciences》 SCIE CSCD 2022年第8期1471-1492,共22页
The spatial relationships between traffic accessibility and supply and demand(S&D)of ecosystem services(ESs)are essential for the formulation of ecological compensation policies and ESs regulation.In this study,an... The spatial relationships between traffic accessibility and supply and demand(S&D)of ecosystem services(ESs)are essential for the formulation of ecological compensation policies and ESs regulation.In this study,an ESs matrix and coupling analysis method were used to assess ESs S&D based on land-use data for 2000,2010,and 2020,and spatial regression models were used to analyze the correlated impacts of traffic accessibility.The results showed that the ESs supply and balance index in the middle reaches of the Yangtze River urban agglomeration(MRYRUA)continuously decreased,while the demand index increased from 2000 to 2020.The Gini coefficients of these indices continued to increase but did not exceed the warning value(0.4).The coupling degree of ESs S&D continued to increase,and its spatial distribution patterns were similar to that of the ESs demand index,with significantly higher values in the plains than in the montane areas,contrasting with those of the ESs supply index.The results of global bivariate Moran’s I analysis showed a significant spatial dependence between traffic accessibility and the degree of coupling between ESs S&D;the spatial regression results showed that an increase in traffic accessibility promoted the coupling degree.The present results provide a new perspective on the relationship between traffic accessibility and the coupling degree of ESs S&D,representing a case study for similar future research in other regions,and a reference for policy creation based on the matching between ESs S&D in the MRYRUA. 展开更多
关键词 traffic accessibility ecosystem services supply ecosystem services demand coupling analysis spatial regression middle reaches of the Yangtze River urban agglomeration China
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