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Spatio-temporal evolution and topographic gradient effect of land use and ecosystem service value in the Lhasa River Basin
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作者 ZHOU Jianwei FENG Bin +8 位作者 WU Hua XU Tong CHEN Linna ZHAO Xinyong GUO Qiyun LI Jiatong ZHANG Chenguang ZHU Kangcheng KONG Yuzhong 《Journal of Mountain Science》 SCIE CSCD 2024年第6期2059-2074,共16页
The Lhasa River Basin forms an essential human settlement area in the southern part of the Qinghai-Tibet Plateau.This study employed ecosystem service value(ESV)evaluation model,terrain gradient grading,and Geodetecto... The Lhasa River Basin forms an essential human settlement area in the southern part of the Qinghai-Tibet Plateau.This study employed ecosystem service value(ESV)evaluation model,terrain gradient grading,and Geodetector to analyze land use and ESV in the Lhasa River Basin from 1985 to 2020.The findings reveal that:(1)From 1985 to 2020,grassland was the dominant land use.There was a trend of grassland reduction and the expansion of other land types.(2)ESV has increased over the research period(with a total increase of 0.84%),with higher values in the southeast and lower values in the northwest.Grassland contributed the most to ESV,and climate regulation and hydrological regulation were the ecosystem services that contribute the most to ESV.(3)Natural factors like NDVI and altitude,as well as economic factors like population density and distance from roads,influenced the spatial differentiation of ESV,the explanatory power of NDVI reached up to 0.47.The interaction between factors had a greater impact than individual factors.These research results can provide theoretical support for national spatial planning and ecological environment protection in the Lhasa River Basin and other similar areas. 展开更多
关键词 Ecosystem services value Land use Terrain gradient effect Lhasa River Basin Driving factors
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Novel miR-490-3p/hnRNPA1-b/PKM2 axis mediates the Warburg effect and proliferation of colon cancer cells via the PI3K/AKT pathway
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作者 Xiang-Hui Wan Guo-Bing Jin +8 位作者 Qun Yang Ji-Long Hu Zhi-Liang Liu Jun Rao Can Wen Peng-Ling Li Xi-Mei Yang Bo Huang Xiao-Zhong Wang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第5期2038-2059,共22页
BACKGROUND Heterogeneous ribonucleoprotein A1(hnRNPA1)has been reported to enhance the Warburg effect and promote colon cancer(CC)cell proliferation,but the role and mechanism of the miR-490-3p/hnRNPA1-b/PKM2 axis in ... BACKGROUND Heterogeneous ribonucleoprotein A1(hnRNPA1)has been reported to enhance the Warburg effect and promote colon cancer(CC)cell proliferation,but the role and mechanism of the miR-490-3p/hnRNPA1-b/PKM2 axis in CC have not yet been elucidated.AIM To investigate the role and mechanism of a novel miR-490-3p/hnRNPA1-b/PKM2 axis in enhancing the Warburg effect and promoting CC cell proliferation through the PI3K/AKT pathway.METHODS Paraffin-embedded pathological sections from 220 CC patients were collected and subjected to immunohistochemical analysis to determine the expression of hnRNPA1-b.The relationship between the expression values and the clinicopathological features of the patients was investigated.Differences in mRNA expression were analyzed using quantitative real-time polymerase chain reaction,while differences in protein expression were analyzed using western blot.Cell proliferation was evaluated using the cell counting kit-8 and 5-ethynyl-2’-deoxyuridine assays,and cell cycle and apoptosis were detected using flow cytometric assays.The targeted binding of miR-490-3p to hnRNPA1-b was validated using a dual luciferase reporter assay.The Warburg effect was evaluated by glucose uptake and lactic acid production assays.RESULTS The expression of hnRNPA1-b was significantly increased in CC tissues and cells compared to normal controls(P<0.05).Immunohistochemical results demonstrated significant variations in the expression of the hnRNPA1-b antigen in different stages of CC,including stage I,II-III,and IV.Furthermore,the clinicopathologic characterization revealed a significant correlation between hnRNPA1-b expression and clinical stage as well as T classification.HnRNPA1-b was found to enhance the Warburg effect through the PI3K/AKT pathway,thereby promoting proliferation of HCT116 and SW620 cells.However,the proliferation of HCT116 and SW620 cells was inhibited when miR-490-3p targeted and bound to hnRNPA1-b,effectively blocking the Warburg effect.CONCLUSION These findings suggest that the novel miR-490-3p/hnRNPA1-b/PKM2 axis could provide a new strategy for the diagnosis and treatment of CC. 展开更多
关键词 Heterogeneous ribonucleoprotein A1-b MiR-490-3p Colon cancer Alternative splicing Warburg effect
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Preliminary study on the protective effect of electroacupuncture Neiguan acupoint pretreatment on rats with myocardial ischemia-reperfusion injury:role of the miR-214-3p/NCX1 axis
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作者 Hai-Long Fan Ya-Qin Liu +4 位作者 Li-Li Jiang Qi-Rong Li Li-Li Niu Li-Zhen Yang Fu-Ran Du 《Integrative Medicine Discovery》 2024年第27期1-11,共11页
Background:Ischemia-reperfusion can worsen myocardial damage and increase the risk of death.Studies have revealed that ischemic preconditioning provides the best endogenous protection against myocardial ischemia-reper... Background:Ischemia-reperfusion can worsen myocardial damage and increase the risk of death.Studies have revealed that ischemic preconditioning provides the best endogenous protection against myocardial ischemia-reperfusion injury(MIRI),and the principle of electroacupuncture(EA)preconditioning is comparable to that of myocardial ischemic preconditioning adaption.Our earlier research demonstrated that EA pretreatment inhibits the expression of calmodulin-dependent protein kinase IIδ(CaMKIIδ),sodium/calcium exchanger 1(NCX1),and cyclophilin D,hence providing protection against MIRI.However,the exact mechanism is still unknown.The expression of NCX1 mRNA is directly regulated by microRNA-214(miR-214).Moreover,it suppresses the levels of CaMKIIδand cyclophilin D.Whether these variables contribute to EA preconditioning to improve MIRI needs to be investigated,though.This study aimed to preliminarily determine whether EA pretreatment ameliorates MIRI by modulating the miR-214-3p/NCX1 axis.Methods:We used a rat MIRI model to investigate the effect of EA pretreatment on MIRI and the expression of miR-214-3p.In addition,adenovirus injection inhibited miR-214-3p expression in the rat MIRI model,and the influence of EA pretreatment towards MIRI was observed in the context of blocked miR-214-3p expression.Both the myocardial histological abnormalities and the alterations in the ST segment of the rat electrocardiogram were analyzed.NCX1 mRNA,cyclophilin D,and CaMKIIδexpression levels were also analyzed.Results:EA pretreatment improved MIRI.In rats with MIRI,EA administration increased miR-214-3p expression while decreasing NCX1 mRNA,cyclophilin D,and CaMKIIδproteins in cardiac tissues.The beneficial effect of EA pretreatment against MIRI was reversed,coupled with elevated levels of NCX1 mRNA,cyclophilin D,and CaMKIIδprotein expression,when an adenovirus injection disrupted the expression of miR-214-3p.Conclusions:Our findings preliminarily show that EA pretreatment inhibits the expression of NCX1 mRNA,cyclophilin D,and CaMKIIδproteins via miR-214-3p,hence exerting MIRI protection. 展开更多
关键词 myocardial ischemia-reperfusion injury miR-214-3p NCX1 ELECTROACUPUNCTURE protective effect
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An Uncertain Programming Model for Land Use Structure Optimization to Promote Effectiveness of Land Use Planning 被引量:4
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作者 LI Xin MA Xiaodong 《Chinese Geographical Science》 SCIE CSCD 2017年第6期974-988,共15页
Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the r... Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the researcher first expounded the uncertainties of LUSO. Based on this, an interval programming model was developed, of which interval variables were to hold land use uncertainties. To solve the model, a heuristics based on Genetic Algorithm was designed according to Pareto Optimum principle with a confidence interval under given significance level to represent LUSO result. Proposed method was applied to a real case of Yangzhou, an eastern city in China. The following conclusions were reached. 1) Different forms of uncertainties ranged from certainty to indeterminacy lay in the five steps of LUSO, indicating necessary need of comprehensive approach to quantify them. 2) With regards to trade-offs of conflicted objectives and preferences to uncertainties, our proposed model displayed good ability of making planning decision process transparent, therefore providing an effective tool for flexible land use planning compiling. 3) Under uncertain conditions, land use planning effectiveness can be primarily enhanced by flexible management with reserved space to percept and hold uncertainties in advance. 展开更多
关键词 land use structure optimization (LUSO) UNCERTAINTIES FLEXIBILITY land use planning decision support system effectiveness
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Land Use Change During 1960~2000 Period and itsEco-environmental Effects in the Middle and UpperReaches of the Yangtze River:a Case Study in YiliangCounty,Yunnan,China 被引量:4
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作者 YANGZisheng LIANGLuohui +1 位作者 LIUYansui HEYimei 《Journal of Mountain Science》 SCIE CSCD 2004年第3期250-263,共14页
Land use/land cover change (LUCC) is a focus of the research of global environmental changes. The middle and upper reaches of the Yangtze River, which are the most ecologically fragile mountainous area in China as wel... Land use/land cover change (LUCC) is a focus of the research of global environmental changes. The middle and upper reaches of the Yangtze River, which are the most ecologically fragile mountainous area in China as well as one of the areas in China with most notable LUCC, have been on the Chinese Government's list of priority areas for ecological restoration. This paper is to reveal the trend of LUCC and the ecological degradation arising from it, and to provide a basis for the future sustainable use of land resources in the region based on a detailed analysis of Yiliang County. Based on the county's land use/cover maps in 1960, 1980 and 2000 drawn with the aid of aerial photograph interpretation, field investigation and GIS based spatial-temporal data analysis, LUCC during 1960~2000 period and the ecological degradation arising from it were analyzed. Using the Markv model, the paper brings out a forecast of what the county's LUCC would be like if the county's current land use continues, as well as the reasons and countermeasures for restoring degraded ecosystems. 展开更多
关键词 Land use/cover change (LUCC) drivingforce eco-environmental effect ecological security sustainable use upper reaches of the Yangtze River
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Effects of Land Use Change on Eco-environment in Hilly Area of Central Sichuan Basin——A Case Study of Yanting County, Sichuan Province 被引量:2
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作者 Luo Huai-liang, Zhu Bo, Chen Guo-jie, Gao Mei-rongInstitute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China College of Resources and Environment, Sichuan Normal University, Chengdu 610066, Sichuan, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03B期981-986,共6页
With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts ... With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts operated over long time, measurement and calculation of NPP (net primary production) and biomass of biological community, and analysis of soil organic matter content show that the artificial alder and cypress mixed forest has outstanding eco-environmental effect: adjusting local climate, raising soil fertility, alleviating menace of drought, and raising NPP and biomass of biological community. It is very beneficial for improving ecological environment to afforest artificial alder and cypress mixed forest in populous Hilly Area of Central Sichuan Basin, China. Key Words: land use/land cover change (LUCC); eco-environmental effect; Hilly Area of Central Sichuan Basin; the artificial alder and cypress mixed forest 展开更多
关键词 of as for Sichuan Province effects of Land use Change on Eco-environment in Hilly Area of Central Sichuan Basin A Case Study of Yanting County on ECO
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Anomalous spin Josephson effect in spin superconductors
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作者 曾文 沈瑞 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期126-131,共6页
The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson ef... The spin superconductor state is the spin-polarized triplet exciton condensate,which can be viewed as a counterpart of the charge superconductor state.As an analogy of the charge Josephson effect,the spin Josephson effect can be generated in the spin superconductor/normal metal/spin superconductor junctions.Here we study the spin supercurrent in the Josephson junctions consisting of two spin superconductors with noncollinear spin polarizations.For the Josephson junctions with out-of-plane spin polarizations,the possibleπ-state spin supercurrent appears due to the Fermi momentum-splitting Andreev-like reflections at the normal metal/spin superconductor interfaces.For the Josephson junctions with in-plane spin polarizations,the anomalous spin supercurrent appears and is driven by the misorientation angle of the in-plane polarizations.The symmetry analysis shows that the appearance of the anomalous spin Josephson current is possible when the combined symmetry of the spin rotation and the time reversal is broken. 展开更多
关键词 tunneling junction spin supercurrent 0-πtransition anomalous spin Josephson effect
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Changes of landuse form and their ecological effect on desert-steppe area in Ningxia
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作者 WEN Yun-chao1, FENG Han-ping1, YU Jiang-ping1, WANG Yi-ming2 (1.Institute of Geographic, Sciences and Natural Resources Research, Chinese Academy of Beijing 100101,China 2.National Land Division, Ningxia Economic Commission, Yinchuan, 750001, China) 《Journal of Geographical Sciences》 SCIE CSCD 2000年第4期103-108,共6页
The central part of Ningxia is a desert-steppe area with a sparse population and fragile ecosystem where over-grazing has caused serious degeneration of steppe ecosystem; however, the southern part is a populous loess... The central part of Ningxia is a desert-steppe area with a sparse population and fragile ecosystem where over-grazing has caused serious degeneration of steppe ecosystem; however, the southern part is a populous loessic hilly area subject to serious soil erosion. The central desert steppe has become an oasis with immigrants from southern loessic hilly area thanks to the implementation of new irrigated projects by pumping water from the Yellow River. Using government investment and loan of World Bank, the new irrigated area has been developed which covers an area of 32,527 ha with 145 thousand immigrants moving there from the southern loessic hilly area in 1984-1994. A new ecosystem of oasis economy has been established, socio-economic, and environmental benefits achieved, and changes in land use were prominent. In the central desert steppe of Ningxia, except the original pasture and dryland farming, irrigational farming, horticulture and livestock breeding have been developed. As a result, artificial ecosystems of various types have been formed in the irrigated areas mentioned above. This paper will particularly discusses the changes of landuse patterns in resultant ecological effects, and the environemntal problems for sustainable development in the irrigated area. For the changes of landuse patterns, four aspects are relevant: the dryland was changed into irrigated land, the grassland became irrigated farmland, the agricultural landuse pattern changed and the cropping patterns also altered. The ecological benefits of the irrigated area are as follows: 1) the desert-steppe has been partially replaced by man-made oasis; 2) drinking water for human and livestock was guaranteed; 3) the shifting sand dunes in some areas were brought under control; 4) soil erosion was mitigated; 5) soil mellow process was accelerated and soil fertility increased; and 6) the eco-economic system was diversified. Finally, the authors identifies solutions to the environmental problems, including water pollution. Soil secondary salinization, soil strucrure, improvement shelterbelt construction, all related to sustainable development in irrgational area. 展开更多
关键词 land use ecological effect IRRIGATION suslainable development Ningxia
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Anti-tumor effects induced by gene vaccines co-expressing truncated human prostate specific membrane antigen gene and mouse 4-1BBL
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作者 匡幼林 《外科研究与新技术》 2011年第4期250-250,共1页
Objective To investigate the influence of m4-1BBL on anti-tumor effects induced by truncated human prostate specific membrane antigen ( tPSMA ) gene in mice. Methods A eukaryotic expression plasmid encoding tPSMA and ... Objective To investigate the influence of m4-1BBL on anti-tumor effects induced by truncated human prostate specific membrane antigen ( tPSMA ) gene in mice. Methods A eukaryotic expression plasmid encoding tPSMA and m4-1BBL ( pDC316-tPSMA-IRES m4-1BBL) ,pDC316-tPSMA and pDC316 were constructed. 展开更多
关键词 GENE Anti-tumor effects induced by gene vaccines co-expressing truncated human prostate specific membrane antigen gene and mouse 4-1BBL IRES
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Effects of Slow Release Fertilizer on the Yield and Nutrient Use Efficiency of Carnation and Its Environmental Protection Effect 被引量:4
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作者 杜彩艳 段宗颜 +1 位作者 胡万里 陈拾华 《Agricultural Science & Technology》 CAS 2011年第4期571-575,共5页
[Objective] The aim was to study the effects of slow release fertilizer on the yield,economic benefit and nutrient use efficiency of carnation and environmental pollution.[Method] Taking carnation(Dianthus caryophyl... [Objective] The aim was to study the effects of slow release fertilizer on the yield,economic benefit and nutrient use efficiency of carnation and environmental pollution.[Method] Taking carnation(Dianthus caryophyllus)as research object,the application effect and environmental protection effect of slow release fertilizer on carnation were discussed through field plot test.[Result] The main agronomic characters of carnation improved after the application of slow release fertilizer;compared with Conv-F treatment,the yield of carnation with slow release fertilizer increased by 18.67%-20.83%,and its economic benefit increased by 105 500 yuan/hm2,while the ratio of output to input improved by 74.29%;under the same NPK ratio and nutrient amount,the yield,economic benefit and ratio of output to input of carnation after the application of slow release fertilizer increased by 2.11%,14 800 yuan and 16.2%,respectively;besides,the application of slow release fertilizer improved the nutrient use efficiency of carnation,and N,P and K nutrient use efficiency in Opt-F-0.7% treatment increased by 13.88%,8.57% and 30.14% compared with Conv-F treatment.[Conclusion] Slow release fertilizer could not only reduce the waste of fertilizer resources and improve fertilizer use efficiency but also decrease the pollution caused by nutrient loss,which had important practical significance for protecting ecological environment and promoting the sustainable development of agriculture. 展开更多
关键词 Slow release fertilizer CARNATION YIELD Nutrient use efficiency Environmental protection effect
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Control Effects of Bacillus subtilis DJ-6 and Pyraclostrobin Alone and in Combination Against Fusarium oxysporum 被引量:9
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作者 吉沐祥 姚克兵 +3 位作者 李国平 吴祥 陈宏洲 庄义庆 《Agricultural Science & Technology》 CAS 2014年第11期2020-2025,共6页
[Objective] This study was conducted to screen a synergistic biological fungicide complex to control Fusarium wilt, reducing the use of chemical pesticides. [Method] The inhibitory effects of Bacil us subtilis DJ-6 an... [Objective] This study was conducted to screen a synergistic biological fungicide complex to control Fusarium wilt, reducing the use of chemical pesticides. [Method] The inhibitory effects of Bacil us subtilis DJ-6 and pyraclostrobin alone or in combination at five ratios against Fusarium oxysporum were detected by mea-suring mycelium growth rate in laboratory tests. The growth promotion and disease control effect of combined or single use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000, 1∶2 000 and 1∶3 000 dilutions were detected in field trials. [Result] The EC50 values of combined use of B. subtilis DJ-6 and pyra-clostrobin at ratios of 1∶1, 1∶2, 1∶3, 1∶4 and 1∶5 against F. oxysporum were 5.311 5, 4.008 6, 3.570 6, 3.350 9 and 3.218 9 μg/ml, with the synergistic ratios (SR) of 2.28, 1.77, 1.53, 1.64, 1.11, among which the synergetic effect at 1∶1 was the best. The fungicidal activity of pyraclostrobin was greater than that of B. subtilis DJ-6 in laboratory tests. Field trials revealed that al the 1∶1 000, 1∶2 000 and 1∶3 000 dilu-tions of 20% pyraclostrobin·2×1011 cfu/g B. subtilis DJ-6 WP in combination, 1∶1 000 dilution of 1 ×1012 cfu/g B. subtilis DJ-6 WP and 1∶2 000 dilution of 250 g/L pyra-clostrobin EC promoted the growth of strawberry by increasing plant height, leaf petiole, leaf blade area and stem diameter. Among them, the treatments with 1∶1 000 and 1∶2 000 of 20% pyraclostrobin · 2×1011 cfu/g B. subtilis DJ-6 WP in combina-tion had better effects than other treatments. The control effects of al the treat-ments were measured 30 and 80 d after fungicide application. The control effects of 1∶1 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combina-tion were up to 100% and 93.11%, which were higher than those in al other treat-ments. The second highest control effects were found in the treatment with 1∶ 2 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination, they were 92.49% and 86.49%, higher than those in other treatments except the 1∶1 000 dilution of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 in combination. The control effects of 1∶3 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination were 82.61% and 72.42%, higher than those in treatment with 1∶1 000 dilution of 1×1012 cfu/g B. subtilis DJ-6 WP, but lower than those in treat-ment with 1∶2 000 dilution of 25% pyraclostrobin EC. [Conclusion] Al the results re-vealed that the combination use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000 to 1∶2 000 dilution had better control effect against strawberry Fusarium wilt. 展开更多
关键词 Strawberry Fusarium wilt Bacil us subtilis DJ-6 Pyraclostrobin use in combination Antibacterial activity Plant growth traits Field control effects
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Yield Increasing and Quality Improving Effects of Smash-ridging Method("4453" Effects) and Its Potential in Benefiting the Nation and the People 被引量:4
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作者 韦本辉 《Agricultural Science & Technology》 CAS 2014年第10期1767-1769,共3页
Yuan Longping proposed that smash-ridging technology could be extend-ed widely nationwide. ln the research, smash-ridging technology reconstruct cultiva-tion layers with loose soils in agricultural fields, creating "... Yuan Longping proposed that smash-ridging technology could be extend-ed widely nationwide. ln the research, smash-ridging technology reconstruct cultiva-tion layers with loose soils in agricultural fields, creating "4453" effects, as fol ows: "Four increases" include to increase loosen soil quantity in cultivation layers, soil nutri-ents use, "water pool" in soils, and "oxygen pool" in soils. Four reductions are to reduce soil erosion, carbon emission, salt content and heavy metal in soils. Five resistances refer to improve crop resistance capacity in terms of drought, high tem-perature, lower temperature, disease and lodging. Three improvements indicate to enhance photosynthetic efficiency over 10%, yield in 10%-30% and quality over 5%. lt is researched that without additional chemical fertilizer, yield could increase by 10% by labor force, animal, tractor or smash-ridging machine. What’s more, by smash-ridging cultivation, the depth can be 20 times or higher compared with tractor cultivation, with looser soils. lt is estimated that if smash-ridging cultivation is applied once in agricultural lands in China, present soil layers can be twice as deep as present. Specifical y, the thickness of loose soil-layers could be extended from 10-18 cm at present to 25-35 cm, and natural rainfal would increase by 40 bil ion cm3. After vitalization of soil nutrients, chemical fertilizer would decrease by 7 bil ion kg, and the increased c rops would feed more than 300 mil ion population as per yield at 7 50 kg/hm2. 展开更多
关键词 Smash-ridging technology Extension nationwide lncrease range in 10%-30% Supporting more 300 mil ion population"4453" effects Development potential
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Progress of Scale Effects in Land Use
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作者 徐军亮 章异平 《Journal of Landscape Research》 2009年第7期31-34,共4页
The concepts of scale and scale effect in land use were introduced in this study,and the relationship between scale effect and land use was also discussed,which showed the deficiency in present studies and the trend o... The concepts of scale and scale effect in land use were introduced in this study,and the relationship between scale effect and land use was also discussed,which showed the deficiency in present studies and the trend of further studies. 展开更多
关键词 LAND use SCALE SCALE effect
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Effects of grazing on net primary productivity,evapotranspiration and water use efficiency in the grasslands of Xinjiang,China 被引量:10
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作者 HUANG Xiaotao LUO Geping +1 位作者 YE Feipeng HAN Qifei 《Journal of Arid Land》 SCIE CSCD 2018年第4期588-600,共13页
Grazing is a main human activity in the grasslands of Xinjiang, China. It is vital to identify the effects of grazing on the sustainable utilization of local grasslands. However, the effects of grazing on net primary ... Grazing is a main human activity in the grasslands of Xinjiang, China. It is vital to identify the effects of grazing on the sustainable utilization of local grasslands. However, the effects of grazing on net primary productivity (NPP), evapotranspiration (ET) and water use efficiency (WUE) in this region remain unclear. Using the spatial Biome-BGC grazing model, we explored the effects of grazing on NPP, ET and WUE across the different regions and grassland types in Xinjiang during 1979-2012. NPP, ET and WUE under the grazed scenario were generally lower than those under the ungrazed scenario, and the differences showed increasing trends over time. The decreases in NPP, ET and WUE varied significantly among the regions and grassland types. NPP decreased as follows: among the regions, Northern Xinjiang (16.60 g C/(m2·a)), Tianshan Mountains (15.94 g C/(m2·a)) and Southern Xinjiang (-3.54 g C/(m2·a)); and among the grassland types, typical grasslands (25.70 g C/(m2·a)), swamp meadows (25.26 g C/(m2·a)), mid-mountain meadows (23.39 g C/(m2·a)), alpine meadows (6.33 g C/(m2·a)), desert grasslands (5.82 g C/(m2·a)) and saline meadows (2.90 g C/(me.a)). ET decreased as follows: among the regions, Tianshan Mountains (28.95 mm/a), Northern Xinjiang (8.11 mm/a) and Southern Xinjiang (7.57 mm/a); and among the grassland types, mid-mountain meadows (29.30 mm/a), swamp meadows (25.07 mm·a), typical grasslands (24.56 mm/a), alpine meadows (20.69 mm/a), desert grasslands (11.06 mm/a) and saline meadows (3.44 mm/a). WUE decreased as follows: among the regions, Northern Xinjiang (0.053 g C/kg H2O), Tianshan Mountains (0.034 g C/kg H2O) and Southern Xinjiang (0.012 g C/kg H2O); and among the grassland types, typical grasslands (0.0609 g C/kg H2O), swamp meadows (0.0548 g C/kg H2O), mid-mountain meadows (0.0501 g C/kg H2O), desert grasslands (0.0172 g C/kg H2O), alpine meadows (0.0121 g C/kg H2O) and saline meadows (0.0067 g C/kg H2O). In general, the decreases in NPP and WUE were more significant in the regions with relatively high levels of vegetation growth because of the high grazing intensity in these regions. The decreases in ET were significant in mountainous areas due to the terrain and high grazing intensity. 展开更多
关键词 grazing effect grassland type net primary productivity EVAPOTRANSPIRATION water use efficiency BiomeBGC grazing model
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The causes and environmental effects of land use conversion during agricultural restructuring in Northeast China 被引量:6
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作者 刘彦随 甘红 +1 位作者 Jay GAO DENG Xusheng 《Journal of Geographical Sciences》 SCIE CSCD 2004年第4期488-494,共7页
During the last decade of the 20th century, extensive conversion inagricultural land use took place in Northeast China. The goal of this study is to ascertain itsspatial distribution and regional differentiation, dete... During the last decade of the 20th century, extensive conversion inagricultural land use took place in Northeast China. The goal of this study is to ascertain itsspatial distribution and regional differentiation, determine its causes, and analyze itsenvironmental impact. Especially we attempt to elucidate how institutional constraints havefacilitated the change at a time of agrarian restructuring when newly emerging free market washybridized with the former planned economy. Information on six categories of land use was mappedfrom interpretation of Landsat TM images recorded in 1990, 1995 and 2000. Most of land use changestook place during the first half of the decade, coinciding with abrupt and chaotic changes ingovernment directives. Farmland was changed mainly to woodland, water body and built-up areas whilewoodland and grassland were converted chiefly to farmland. Spatially, the change from farmland towoodland was restricted to the west of the study area. The change from grassland to farmland tookplace in the grazing and farming interlocked west. These chaotic and occasionally conflictingchanges were largely caused by lack of stability and consistency in agricultural land use policiespromulgated. They have exerted adverse impacts on the local environment, including land degradation,increased flooding, and modified climate regime. 展开更多
关键词 land use conversion agricultural restructuring remote sensing environmental effects northeast China
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Effect of Agricultural Land Use Changes on Soil Nutrient Use Efficiency in an Agricultural Area,Beijing,China 被引量:5
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作者 CHEN Liding QI Xin +2 位作者 ZHANG Xinyu LI Qi ZHANG Yanyan 《Chinese Geographical Science》 SCIE CSCD 2011年第4期392-402,共11页
Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in th... Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in the rural areas of China.The purpose of this study is to evaluate the effect of these land use changes on the soil properties,nu-trient absorption rate,and nutrient use economic efficiency ratio in an agricultural area of Beijing.Specifically,the cropland,the orchard and the vegetable field were examined.Results of this study suggest that land use and farming management practices significantly affect the content of soil organic carbon (SOC),total nitrogen (TN),total phos-phorus (TP),and available phosphorus in the surface layer of 0-25 cm (p<0.05) in the Yanqing Basin,northwestern Beijing.Soil nutrients in each agricultural land use type decrease rapidly with the increasing soil depth.Orchard and vegetable field tend to have higher soil nutrients than the cropland does.However,the soil nutrient-absorption rate (NAR) of the orchard and vegetable field is lower than that of the cropland,even though orchard and vegetable field may provide much higher economic benefit.While increasing SOC,TN,and TP in the orchard and vegetable field by intensive farming may be a valuable option to improve soil quality,potential increase in the risk of nutrient loss,or agricultural non-point source pollution can be a tradeoff if the intensive practices are not managed appropriately. 展开更多
关键词 agricultural land use soil nutrient absorption rate (NAR) soil nutrient use economic efficiency ratio (NEER) soil property environmental effect
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Land use change and its ecological effect in Qian’an County of Jilin Province 被引量:4
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作者 ZHONGLinsheng ZHANGYongmin +1 位作者 ZHAOShidong KarlE.Rvavec 《Journal of Geographical Sciences》 SCIE CSCD 2003年第4期423-428,共6页
Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian'an County in both spatial and temporal aspects from 1945 ... Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian'an County in both spatial and temporal aspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changes and their ecological effects are discussed too. The main findings of this study are as follows: (1) Land use changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetland and water bodies, and an increase in cultivated land, saline-alkali land, and the land for housing and other construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by 102,137.23 ha over the half century. Accordingly, the main landscape type changed from a steppe landscape to a managed agricultural ecosystem. (2) Results of correlation analysis show that the land use change in the study area was mainly driven by the socioeconomic factors. (3) The ecological effects of land use change in the area are characterized by serious salinization, degression of soil fertility and the weakening of landscape suitability. 展开更多
关键词 land use change ecological effect land degradation Qian'an County
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Effect of switching from treatment with nucleos(t)ide analogs to pegylated interferon α-2a on virological and serological responses in chronic hepatitis B patients 被引量:16
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作者 Li-Ting He Xiao-Guang Ye Xiao-Yuan Zho 《World Journal of Gastroenterology》 SCIE CAS 2016年第46期10210-10218,共9页
AIM To investigate the efficacy of switching to pegylated interferon-α-2a(Peg IFNα-2a) treatment in nucleos(t)ide analog(NA)-treated chronic hepatitis B(CHB) responder patients. METHODS A 48-wk prospective and retro... AIM To investigate the efficacy of switching to pegylated interferon-α-2a(Peg IFNα-2a) treatment in nucleos(t)ide analog(NA)-treated chronic hepatitis B(CHB) responder patients. METHODS A 48-wk prospective and retrospective treatment trial of NA-treated CHB patients who had received entecavir(ETV) for at least 48 wk and had serum hepatitis B virus(HBV)-DNA < 500 IU/m L, serum hepatitis B envelope antigen(HBe Ag) < 100 S/CO, serum alanine aminotransferase, and aspartate aminotransferase levels < 2 × the upper limit of normal of 40 IU/L was performed. The effects on virological and serological responses and adverse reactions to 0.5 mg daily ETV for 48 wk vs switching to Peg IFNα-2a were compared. Forty-four patients were randomized to be switched from NA treatment to the Peg IFNα-2a group, and 44 patients were simultaneously randomized to the ETV group. RESULTS After 48 wk of therapy, the decrease in hepatitis B surface antigen(HBs Ag) levels was greater in the Peg IFNα-2a group than in the ETV group(3.1340 log10 IU/m L vs 3.6950 log10 IU/m L, P = 0.00). Seven patients who were anti-HBs-positive at baseline achieved HBs Ag loss when switched to Peg IFNα-2a(15.91% vs 0%,P = 0.018). The HBe Ag serological conversion rate was higher in the Peg IFNα-2a group than in the ETV group; however, the difference was not significant because of the small sample sizes(34.38% vs 21.88%, P = 0.232). In the Peg IFNα-2a group, patients with HBs Ag levels < 1500 IU/m L at baseline had higher HBe Ag seroconversion and HBs Ag loss rates at week 48 than those with HBs Ag levels ≥ 1500 IU/m L(HBe Ag seroconversion: 17.86% vs 62.5%, P = 0.007; HBs Ag loss: 41.67% vs 6.25%, P = 0.016). Moreover, patients with HBs Ag levels < 1500 IU/m L at week 24 had higher HBs Ag loss rates after therapy than those with HBs Ag levels ≥ 1500 IU/m L(36.84% vs 0%, P = 0.004). However, there were no statistically significant differences in HBe Ag seroconversion rates(47.06% vs 25.93%, P = 0.266). CONCLUSION NA-treated CHB patients switched to sequential Peg IFNα-2a achieved highly potent treatment termination safely. 展开更多
关键词 Chronic hepatitis B ENTECAVIR pegylated interferon-α-2a Sequential therapy effect
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Land use change and effect analysis of tideland reclamation in Hangzhou Bay 被引量:4
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作者 LI Jin-tao LIU Yan-sui YANG Yuan-yuan 《Journal of Mountain Science》 SCIE CSCD 2018年第2期394-405,共12页
Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in C... Since the beginning of the 20th century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in China. The increase of land area alleviated the contradiction of supply and demand between human and land, which provided the guarantee for agricultural production and industrial development. However, marine ecological environment has been seriously damaged due to the increasing scale of tideland reclamation. This paper took the Hangzhou Bay in the Yangtze River Delta as a study area to explore the evolution law, socioeconomic effect and eco-environmental effect of reclaimed land from 1985 to 2015. The result showed that as follows:(1) The area of tideland reclamation was 460.67 km^2 with 16.57% cultivated land and 15.93% construction land, and its land use was inefficient;(2) Land use change has spatial and temporal difference, the speed of tideland reclamation had been increasing from 1985 to 2015 in time and the scale of reclaimed land in the southern(84.07%) of Hangzhou Bay was larger than the northern region(15.93%) in space;(3) The evolution law of land use was from tideland to swampland and coastal waters to agricultural facility land, to cultivated land to industrial-mining land to idle land, rural-urban construction land, and formed obviously hierarchical structure;(4) Effect analysis of land use change found that the socio-economic effect had increased but the eco-environmental effect had decreased from 1985 to 2015, it reflected socio-economic effect was acquired through sacrificing eco-environmental effect;(5) It pointed out the existing problems on land extensive inefficient, environmental degradation and economy excessive growth without scientific planning, and offered some suggestions in land comprehensive improvement project, industrial transformation and upgrading and scientific planning and legal safeguardto promote sustainable development in the Hangzhou Bay in the new period. 展开更多
关键词 Land use change Tideland reclamation effect analysis Hangzhou Bay Yangtze River Delta
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Combining CLUE-S and SWAT Models to Forecast Land Use Change and Non-point Source Pollution Impact at a Watershed Scale in Liaoning Province, China 被引量:15
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作者 LIU Miao LI Chunlin +3 位作者 HU Yuanman SUN Fengyun XU Yanyan CHEN Tan 《Chinese Geographical Science》 SCIE CSCD 2014年第5期540-550,共11页
Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. I... Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making. 展开更多
关键词 Conversion of Land use and its effect at Small regional extent (CLUE-S) Hunhe-Taizi River Watershed non-point source pollution Soil and Water Assessment Tool (SWAT)
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