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Study on Distribution Characteristics and Occurrence Form of Soil Fluorine in Sorghum Base of Renhuai City
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作者 Ziping PAN Maoyan SHAO +2 位作者 Xubin HUANG Ting CHEN Luyao SUI 《Agricultural Biotechnology》 CAS 2023年第1期66-71,共6页
In order to find out the effects of soil fluorine on ecological environment and crop safety in the sorghum cultivation base of Renhuai City, Guizhou Province, the content and the occurrence forms of soil fluorine and ... In order to find out the effects of soil fluorine on ecological environment and crop safety in the sorghum cultivation base of Renhuai City, Guizhou Province, the content and the occurrence forms of soil fluorine and its influencing factors of Maoba Town were investigated and studied. The results showed that the total fluorine content in the soil of the sorghum base ranged from 668.60 to 2 596.80 mg/kg, with an average of 1 483.25 mg/kg, which was 3.10 and 1.85 times of the national soil background value and the average value of the soil in endemic areas, respectively. The spatial distribution of fluorine in the soil of the study area was uneven, and the fluorine content was in the order of Anliang Village>Yangliu Village>Houba Village>Xiongfeng Village. The soil fluorine contents of various forms varied greatly, and the distribution law was as follows: residual state>water soluble state>organically bound state>exchangeable state>Fe/Mn-F state. The residual fluorine content was the highest, accounting for more than 99% of total fluorine content, while the sum of other four forms was less than 1%, with their respective proportions ranging from 0.10% to 0.30%. The content and proportion of available fluorine in water-soluble and exchangeable states were relatively low, which had limited influence on the surrounding water environment and crop safety. The physicochemical properties of soil, such as pH, organic matter, cation exchange capacity and clay particles had a certain influence on the occurrence forms of soil fluorine, thus changing the availability and migration of soil fluorine, which might endanger the ecological environment safety, food safety and human health. 展开更多
关键词 Sorghum base Soil Fluorine Occurrence form Distribution characteristics Renhuai City
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Resources of Colored-leaf Trees and Their Phenological Ornamental Characteristics in Lhasa City 被引量:2
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作者 LIU Zhineng ZHOU Peng XU Jin 《Journal of Landscape Research》 2017年第1期30-36,共7页
By using biological five points,expert consultation and fuzzy comprehensive evaluation,the species,phenological ornamental characteristics,and landscape application of colored-leaf trees in Lhasa City were surveyed sy... By using biological five points,expert consultation and fuzzy comprehensive evaluation,the species,phenological ornamental characteristics,and landscape application of colored-leaf trees in Lhasa City were surveyed systematically. The results show that there are 42 species of colored-leaf trees in Lhasa City,belonging to 31 genera and 18 families,of which there are 5,19,and 18 species of spring,autumn,and common colored-leaf trees,accounting for 11.90%,45.24% and 42.86% of total number of the investigated tree species respectively. It is clearly seen that there are too few species of spring colored-leaf trees in the city. There are 19 and 17 species of trees possessing red and yellow leaves,while the leaves of other 6 species of colored-leaf trees are shown in other colors,and the number of their species accounts for 45.24%,40.48% and 14.28% of total number of the investigated tree species respectively. The best ornamental periods of spring,autumn and common colored-leaf trees in Lhasa City average 38.4,41.8 and 251.8 d respectively. Prunus cerasifera Ehrhar f. atropurpurea Rehd.,Ulmus pumila L.,Populus × beijingensis W. Y. Hsu,and Salix alba are applied most frequently in Lhasa City,and their relative frequency is 18.67%,10.29%,9.91% and 8.95% respectively. According to the comprehensive assessment value of their ornamental characteristics,the ornamental characteristics of 15 species of colored-leaf trees in Lhasa City are good or very good,and there is a positive correlation between the comprehensive assessment value and relative frequency. Based on the investigation,the current application situation and problems of colored-leaf trees in Lhasa City were analyzed,and solutions to the problems were proposed. 展开更多
关键词 TIBET Lhasa City Colored-leaf trees PHENOLOGY Ornamental period Comprehensive assessment value Frequency
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Research on the relation between the geologic environment and the trace elements of underground water in Huaibei Coalfield 被引量:1
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作者 宋晓梅 胡宝林 +1 位作者 桂和荣 陈陆望 《Journal of Coal Science & Engineering(China)》 2004年第2期42-46,共5页
Based on testing the trace elements of the four main aquifers of underground water in Huaibei Coalfield by using the ICP-MS in the University of Science and Tech- nology of China(USTC), the relation of trace elements ... Based on testing the trace elements of the four main aquifers of underground water in Huaibei Coalfield by using the ICP-MS in the University of Science and Tech- nology of China(USTC), the relation of trace elements of the four main aquifers was analyzed by using maximum correlation coefficient method. The study indicates that the different aquifers posses respective microelement distributional characteristics, which caused with average contents of trace elements in the different aquifers are related to the pH of the underground water and the contents of trace elements of the wall rock source in the research area, so researching on the distribution of geographic space and the change trend of hydro-geochemical character of different aquifers and the relation of the geologic environment and the trace elements conduce to establish the disciminand model of water inrush source. 展开更多
关键词 AQUIFER trace element geochemical characteristic CORRELATIVITY
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Geographical Variation in the Advertisement Calls of Leptobrachella ventripunctata(Anura:Megophryidae)in Southwestern China
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作者 Chaobo FENG Tuo SHEN +4 位作者 Lang MU Jing LIU Shize LI Yixin DIAO Haijun SU 《Asian Herpetological Research》 SCIE CSCD 2024年第3期140-151,共12页
In anurans,advertisement calls(ACs)are an essential form of intraspecific communication.This study evaluates geographical variation in the ACs of Leptobrachella ventripunctata in the Guizhou Plateau,southwestern China... In anurans,advertisement calls(ACs)are an essential form of intraspecific communication.This study evaluates geographical variation in the ACs of Leptobrachella ventripunctata in the Guizhou Plateau,southwestern China,and explores correlations between call characteristics,body size,and environmental factors.ACs are simple calls of L.ventripunctata,and apparent differences were observed in the ACs among different geographical populations of L.ventripunctata.The Call duration(CD)revealed a significant positive correlation with altitude and a significant negative correlation with temperature and humidity.Moreover,the Dominant frequency(DF)exhibited a significant negative correlation with altitude and the habitat closure degree and a significant positive correlation with temperature.These variations in ACs between different geographical populations of L.ventripunctata may critically impact the adaptive evolution of species,and the calls may also be relevant for environmental selection. 展开更多
关键词 ANURAN BIOACOUSTICS environmental factors geographical divergence
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The Optimization and Thinking about Traditional Living Environment of the Tibetan Gongbu Culture——In the Case of Juemu Village on the Side of the Niyang River
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作者 Wenbo LI Yue LU +2 位作者 Nengqiang LIN Liping FAN Qionghua JIANG 《Asian Agricultural Research》 2017年第10期49-54,共6页
Based on the problems of traditional living environment of the Tibetan Gongbu culture and the concept of inheriting the Tibetan Gongbu culture and the harmonious coexistence of environment and human,living environment... Based on the problems of traditional living environment of the Tibetan Gongbu culture and the concept of inheriting the Tibetan Gongbu culture and the harmonious coexistence of environment and human,living environment design of Juemu Village on the side of the Niyang River is optimized. It adheres to the importance of traditional culture,and especially emphasizes the layout of buildings with Tibetan style and their surrounding,function optimization,and the plant design,thereby exploring and attempting planning method of Tibetan living environment under the background of new rural construction. 展开更多
关键词 Gongbu culture Juemu Village Living environment OPTIMIZATION THINKING
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Total Factor Productivity and Influence Factors of Economic Environment in the Yellow River Delta
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作者 SHAN Changqing 《Journal of Landscape Research》 2016年第5期93-96,共4页
The paper analyzed total factor productivity of Binzhou City, and key factors that influence its economic growth and effluent discharge. The results showed that(i) production efficiency of the city during 2005–2013 k... The paper analyzed total factor productivity of Binzhou City, and key factors that influence its economic growth and effluent discharge. The results showed that(i) production efficiency of the city during 2005–2013 kept stable, mean of Malmquist-Luenberger index was 1.044,9 without considering effluent discharge, and the average annual increase rate was 4.49%, and that was 1.020,4 considering effluent discharge, the average annual increase rate was 2.04%, and the increase rate reduced by 2.45%.(ii) GDP growth showed significant negative correlation and positive correlation with capital input and energy input, but insignificant negative correlation and positive correlation with labor force input and technological progress.(iii) Effluent discharge showed insignificant negative correlation and positive correlation with capital input and energy input, but significant negative correlation and positive correlation with labor force input and technological progress. 展开更多
关键词 The Yellow River Delta Total factor productivity Economic environment Influence factor
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Survey on Germplasm Resources of Araliaceae Plants in Southeastern Tibet and Study on Their Landscape Application
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作者 Kuang WANG Junli AN +2 位作者 Zhen XING Xuesen LIU Weilie ZHENG 《Asian Agricultural Research》 2018年第9期46-52,共7页
In recent years,the Araliaceae plants have been widely used in the planning of urban garden and road green space. China is rich in Araliaceae plant resources and Araliaceae plants are outstanding in form,but their orn... In recent years,the Araliaceae plants have been widely used in the planning of urban garden and road green space. China is rich in Araliaceae plant resources and Araliaceae plants are outstanding in form,but their ornamental value is less studied. Through the statistical survey of the germplasm resources of Araliaceae plants in southeastern Tibet,and the research and analysis of their functions and ornamental characteristics,this paper concluded that the Araliaceae plants in southeastern Tibet have high ornamental value,and 12 varieties of Araliaceae plants can be used in gardens and have great research and development significance. Finally,it came up with recommendations for the collection and protection,introduction and breeding,and garden application of Araliaceae plant resources. 展开更多
关键词 栀子科植物 城市发展 城市绿化 种植业
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Different responses of soil respiration and its components to nitrogen and phosphorus addition in a subtropical secondary forest 被引量:5
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作者 Junjun Zhang Yong Li +3 位作者 Jinsong Wang Weinan Chen Dashuan Tian Shuli Niu 《Forest Ecosystems》 SCIE CSCD 2021年第3期491-503,共13页
Background:Nitrogen(N)and phosphorus(P)deposition have largely affected soil respiration(Rs)in forest ecosystems.However,few studies have explored how N and P individually or in combination to influence Rs and its com... Background:Nitrogen(N)and phosphorus(P)deposition have largely affected soil respiration(Rs)in forest ecosystems.However,few studies have explored how N and P individually or in combination to influence Rs and its components(autotrophic respiration,Ra;heterotrophic respiration,Rh),especially in highly P-limited subtropical forests.To address this question,we conducted a field manipulation experiment with N and/or P addition in a 50-year-old subtropical secondary forest.Results:We found that N addition on average reduced Rs,Ra,and Rh by 15.2%,15%,and 11.7%,respectively during 2-year field study.P addition had an inconsistent effect on Ra,with Ra increasing by 50.5%in the first year but reducing by 26.6%in the second year.Moreover,P addition on average decreased Rh by 8.9%–30.9%and Rs by 6.7%–15.6%across 2 years.In contrast,N and P co-addition on average increased Rs,Ra,and Rh by 1.9%,7.9%,and 2.1%during the experimental period.Though Rs and Rh were significantly correlated with soil temperature,their temperature sensitivities were not significantly changed by fertilization.Ra was predominantly regulated by soil nitrogen availability(NH4+and NO3−),soil dissolved organic carbon(DOC),and enzyme activities,while the variation in Rh was mainly attributable to changes in soil microbial community composition and soilβ-D-Cellubiosidase(CB)andβ-Xylosidase(XYL)activities.Conclusion:Our findings highlight the contrasting responses of Rs and its components to N or P addition against N and P co-addition,which should be differentially considered in biogeochemical models in order to improve prediction of forest carbon dynamics in the context of N and P enrichment in terrestrial ecosystems. 展开更多
关键词 Nitrogen deposition Phosphorus enrichment Heterotrophic respiration Autotrophic respiration Enzyme activities Microbial community composition
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SPATIAL AND TEMPORAL VARIABILITY OF NORTHWEST PACIFIC TROPICAL CYCLONE ACTIVITY IN A GLOBAL WARMING SCENARIO 被引量:3
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作者 顾成林 康建成 +1 位作者 闫国东 陈志伟 《Journal of Tropical Meteorology》 SCIE 2016年第S1期15-23,共9页
Utilizing the Joint Typhoon Warning Center(JTWC) and Tokyo-Typhoon Center of the Japan Meteorological Agency(JMA RSMC TOKYO) best-track tropical cyclone(TC) data for the period 1951-2014,variations in spatial and temp... Utilizing the Joint Typhoon Warning Center(JTWC) and Tokyo-Typhoon Center of the Japan Meteorological Agency(JMA RSMC TOKYO) best-track tropical cyclone(TC) data for the period 1951-2014,variations in spatial and temporal characteristics of Northwest Pacific TC activity for a global warming scenario are discussed.The results suggest that since the early 1960 s,there has been an overall decreasing trend in the frequency of occurrence,intensity,peak intensity,length of movement,and lifetime of TCs.However,global wanning has led to a linearly increasing trend in TC activity in eastern Asia,which indicates that Northwest Pacific TC activity decreases,but the frequency of landfalls and intensity are likely strengthened.Therefore,the threat of TCs towards eastern Asia is enhanced.The increase in TC activity in eastern Asia is likely the result of a strengthened Walker circulation due to an increasing temperature gradient between the northwest Pacific Ocean and the central and eastern Pacific Ocean.The strengthening Walker circulation could increase the magnitude of the vertical wind shear,relative vorticity,and meridional wind shear of low-level easterlies near the equator in the tropical Northwest Pacific,which affects the spatial and temporal variations of TC activity in the Northwest Pacific. 展开更多
关键词 global WARMING western NORTH PACIFIC TROPICAL CYCLONE spatial and temporal variability
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A flume test on erosion mechanism for an abandoned section of the Huanghe(Yellow)River Delta 被引量:1
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作者 高涛 李广雪 +2 位作者 史经昊 DONG Ping 刘杰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第3期684-692,共9页
The erosion mechanisms of abandoned coastal section are understood detailedly by flume experiment, which play an important role to the offshore engineering facilities. A movable-bed physical model has been used to inv... The erosion mechanisms of abandoned coastal section are understood detailedly by flume experiment, which play an important role to the offshore engineering facilities. A movable-bed physical model has been used to investigate the coastal erosion of an abandoned section of the Huanghe (Yellow) River Delta. The theory of physical scale models is discussed and a method for constructing the representative seabed section is developed. The results indicate that during the period initially after the abandonment of the delta the entire bed experienced rapid erosion because the seabed was steep and prone to liquefaction that resulted from storm wave action. After this initial period, a balance of erosion and accretion was established, and the beach profllc equilibrated with a point of balance present on the profile. The experimental results indicate that the volume of deposition was about half that of the erosion. Wave action may also induce significant stratal changes through its interaction with the soft seabed. The major morphological features developed in the model delta section were found to be qualitatively comparable with those observed in the prototype. A distorted modeling law that maintains the similarity of the modeled and prototype equilibrium beach profiles is proposed. Experimental results show that the distorted modeling is able to reproduce the beach-face slope in nature, and the model also successfully reproduced three historical evolutionary stages of erosion. 展开更多
关键词 abandoned Huanghe (Yellow) River Delta flume simulation WAVE pore pressure EROSION
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Effect of dosage of expandable graphite,dimethyl methylphosphonate,triethanolamine,and isocyanate on fluidity,mechanical,and flame retardant properties of polyurethane materials in coal reinforcement 被引量:5
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作者 Hu Xiangming Wang Deming Cheng Weimin 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第2期345-352,共8页
In this study,orthogonal experiments were conducted to investigate the influence of expandable graphite(EG),dimethyl methylphosphonate(DMMP),triethanolamine(TEA),and isocyanate content on the compressive and bonding s... In this study,orthogonal experiments were conducted to investigate the influence of expandable graphite(EG),dimethyl methylphosphonate(DMMP),triethanolamine(TEA),and isocyanate content on the compressive and bonding strengths,oxygen index,and fluidity of rigid polyurethane foam(RPUF).The results revealed that EG significantly increased the oxygen index of RPUF,enlarged the diameter of foam cells,and decreased the cell-closed content in foam;thus,leading to a pressure drop in RPUF.However,excessive EG was capable of reducing the fluidity of polyurethane slurry.TEA exhibited significant influence on the compressive strength of RPUF,which dropped initially,and then increased.DMMP had a remarkable effect on the flame retardant property and compressive strength of RPUF.Compressive strength of RPUF initially displayed an increase followed by a decrease with increasing dosage of DMMP,and achieved the maximum value at DMMP dosage of 4%.DMMP could effectively reduce the diameter of RPUF cells leading to an increase in the percentage of close area in foam.DMMP displayed the flame-retardation effects mainly in the gas phase leading to a significant enhancement in the oxygen index of RPUF.Moreover,the compressive strength and bonding strength of RPUF decrease significantly with the increase of isocyanate content due to the increased blowing efficiency by the CO_2.The oxygen index and flowing length of foam increased with the increase in isocyanate dosage. 展开更多
关键词 Rigid polyurethane foam Expandable graphite Compressive strength Flame retardant Scanning electron microscopy(SEM) Microstructure
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Effects of Long-term Fertilization on Phosphorus Accumulation and Migration in Purple Soil 被引量:1
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作者 Li Xueping Zou Meiling Ren Jiayun 《Meteorological and Environmental Research》 CAS 2015年第8期46-49,共4页
Based on a long-term location test lasting for 20 years, the accumulation and migration of phosphorus in purple soil was studied. The results showed that P2Os input in paddy-upland rotation was 120.0 kg/( hm2 · ... Based on a long-term location test lasting for 20 years, the accumulation and migration of phosphorus in purple soil was studied. The results showed that P2Os input in paddy-upland rotation was 120.0 kg/( hm2 · a) (a conventional level of phosphorus application), and P had a surplus of 53.9 kg/(hm2 · a). Phosphorus accumulating in soil increased available phosphorus (Olsen-P) content, and the positive correlation between P changing balance and Olsen-P change in wheat-rice rotation was extremely significant. The mixed application of organic fertilizer and chemical P fertilizer can speed up accumulation of available phosphorus in soil. Olsen-P content in all treatments with P fertilizer was higher in 0 -60 cm soil than that of treatments without P fertilizer, and Phosphorus applied in surface soil moved to soil at a depth of 60 cm, increasing risk of P leakage and loss. The migration of phosphorus in soil is affected by P input, type of organic fertilizer and planting method. The quantities of phosphorus moving down increased with the increase of P input, and the application of pig manure can lead to migration of phosphorus in soil more easily compared with straw. The migration of phosphorus from soil to water mainly occurred in the first ten days after rice was transplanted, and paddy field drainage should not be conducted in the first 30 days after rice was transplanted. 展开更多
关键词 Long-term fertilization PHOSPHORUS ACCUMULATION MIGRATION China
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Study of trace elements in coal and mining wastes and its significance in China 被引量:1
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作者 黄文辉 车遥 唐修义 《Journal of Coal Science & Engineering(China)》 2003年第2期43-47,共5页
In the world energy about 26% of all was derived from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past ... In the world energy about 26% of all was derived from coal combustion. Nearly 80% of the electricity produced in China is generated from coal. Coal will play the most important role in the coming 50 years as the past century in China. However one consequentially of the mining and combustion of coal is the mobilization of trace elements, especially trace metals, which have environmental and human health significance. Information on concentrations and distributions of potentially toxic elements in coal, and information on the modes of occurrence of these elements and the relations of the minerals in coal can help to predict the behavior of the potentially toxic trace metals during cleaning, combustion, weathering, and leaching. 展开更多
关键词 Chinese coal mining wastes trace elements environmental and health significance
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Investigation and Analysis on the Present Situation of Indoor Formaldehyde Pollution in Residence of Binzhou City 被引量:1
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作者 Zou Meiling Wen Weiwei Wang Linlin 《Meteorological and Environmental Research》 CAS 2015年第4期11-13,共3页
As gradual improvement of living environment and indoor decoration form diversification, the indoor air pollution has become the "invisi- ble killer" harming human health, and has been listed as one of ten big threa... As gradual improvement of living environment and indoor decoration form diversification, the indoor air pollution has become the "invisi- ble killer" harming human health, and has been listed as one of ten big threats to human health by the World Health Organization, which also be- came one of hot issues concerned by countries all over the world. In this paper, through the determination of formaldehyde in some houses of Binzhou, the release of formaldehyde with the increase of time was explored; change of formaldehyde in the same residence in different functional areas was analyzed; the influence of the temperature, humidity and plant to formaldehyde content was also analyzed. 展开更多
关键词 Indoor formaldehyde pollution Binzhou Investigation and analysis China
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Accumulation Laws of Nitrogen and Phosphorus in Wetland Plants 被引量:1
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作者 ZHENG Huanqiang RONG Kun 《Journal of Landscape Research》 2017年第1期87-90,93,共5页
To study the accumulation regularity of nitrogen and phosphorus in typical constructive plants in coastal wetland,samples of Suaeda glauca(Bunge) Bunge,Phragmites austrahs and Tamarix chinensis Lour,were taken from th... To study the accumulation regularity of nitrogen and phosphorus in typical constructive plants in coastal wetland,samples of Suaeda glauca(Bunge) Bunge,Phragmites austrahs and Tamarix chinensis Lour,were taken from the Yellow River Delta National Coast Wetland Nature Reserve,nitrogen and phosphorus content in plants was measured and analyzed.The results showed that ① nitrogen and phosphorus content in different wetland plants is correlated;② different species in the same place and the same species in different spaces show different accumulation regularity of nitrogen and phosphorus;③ nitrogen and phosphorus content in plants is closely related to nitrogen and phosphorus content in the habitat;④ nitrogen content in T.chinensis Lour,is the highest,the mean is 11.63 g/kg,and phosphorus content in S glauca(Bunge) Bunge is the highest,the mean is 1.38 g/kg;⑤ nitrogen content in the 3 species:T.chinensis Lour.> S.glauca(Bunge) Bunge > P.australis;⑥ nitrogen content in aboveground parts of all plants is significantly higher than that in underground parts,and phosphorus content in aboveground parts of all plants except S.glauca(Bunge) Bunge is significantly higher than that in underground parts;⑦ nitrogen content in the 3 species in the study area is significantly higher than phosphorus content in these species. 展开更多
关键词 The Yellow River Delta Wetland plant Nitrogen and phosphorus content Accumulation law
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Study on Monitoring and Analysis of TSP Caused by Road Traffic in Binzhou City
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作者 Cao Qing Xu Lanjuan 《Meteorological and Environmental Research》 CAS 2016年第4期26-28,共3页
Wind speed,temperature,relative humidity and TSP concentration at three intersections in Binzhou City were monitored,and the relationships of TSP concentration with wind speed,temperature,relative humidity and traffic... Wind speed,temperature,relative humidity and TSP concentration at three intersections in Binzhou City were monitored,and the relationships of TSP concentration with wind speed,temperature,relative humidity and traffic flow at the three intersections in Binzhou City were analyzed by using SPSS.The results show that traffic flow was the main factor affecting TSP concentration of road traffic in Binzhou City. 展开更多
关键词 ROAD traffic Monitoring TOTAL suspended PARTICULATES Binzhou CITY China
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Analysis of Relationships between Sewage Discharge and Economic Development in Binzhou Based on EKCs
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作者 Shan Changqing 《Meteorological and Environmental Research》 CAS 2016年第5期40-42,共3页
Relationships between environmental pollution and economic development in Binzhou during 2001- 2013 were studied through an Environmental Kuznets Curve( EKC). The results showed that with the increase of GDP per capit... Relationships between environmental pollution and economic development in Binzhou during 2001- 2013 were studied through an Environmental Kuznets Curve( EKC). The results showed that with the increase of GDP per capita,the emissions of industrial wastewater,COD and ammonia nitrogen in Binzhou City increased at first and then decreased during 2001- 2013,showing inverted-U-shaped curves where turning points appeared in the middle; the emission of domestic sewage showed an upward trend,and a turning point would not appear in a short term; the emissions of domestic COD and ammonia nitrogen dropped firstly and then rose gradually,showing U-shaped curves,and they would not decrease in a short time. The turning points of industrial wastewater,COD and ammonia were at( 4. 29,14 550),( 2. 46,44 803) and( 2. 27,2 708) respectively; domestic sewage had no turning point,and domestic COD and ammonia nitrogen would not reach the turning points in a short term. 展开更多
关键词 SEWAGE DISCHARGE ECONOMIC development EKC Binzhou China
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Formation Age and Tectonic Setting of the Muli Arc-Ophiolite Complex in the South Qilian Belt, NW China
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作者 YAN Zhen FU Changlei +3 位作者 Jonathan C.AITCHISON NIU Manlan Solomon BUCKMAN CAO Bo 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第S01期69-69,共1页
The Qilian orogenic belt is the northernmost orogen of the Tethyan domain and connects the Altaids to the north. It contains an assembly of Precambrian micro-continental fragments, early Paleozoic island arcs, accreti... The Qilian orogenic belt is the northernmost orogen of the Tethyan domain and connects the Altaids to the north. It contains an assembly of Precambrian micro-continental fragments, early Paleozoic island arcs, accretionary complexes, ophiolites, forearc and backarc basins, and high-pressure(HP) metamorphic rocks, indicating a long history of accretionary processes. Spatially, this orogen is adjacent to the Tarim, Qaidam, and North China blocks, which also extends into accretionary orogenic belts to the east and SW such as the Qinling and Kunlun belts. Abundant ophiolites in this orogen record the closure of an early Tethyan Ocean and amalgamations between micro-continents of North China, Qaidam, and Tarim. Thus, the ages and tectonic settings of these ophiolites within this belt provide important information regarding evolution of the Proto-Tethys Ocean and assembly of micro-continental blocks, which aids understanding of the spatial and temporal relationship of this orogen within the Tethyan realm. Dismembered ophiolites sporadically crop out along the northern margin of the South Qilian belt, and, from east to west, are locally referred to as the Lajishan, Gangcha, Muli, and Dadaoerji ophiolites. Much attention had been paid to these ophiolites, and several competing models for the tectonic evolution of this belt have been suggested. Considerable disagreement remains in respect of the temporal and spatial framework of the Qilian Orogen and details such as timing of subduction(s) and associated polarities, early collision events, and final closure of oceanic basins. In particular, the formation age and tectonic setting of Muli arc-ophiolite complex remains unknown, which limits understanding of the tectonics of the South Qilian belt and the history of the Proto-Tethys Ocean. The Muli arc-ophiolite complex is distributed over 20 km^2 west of the township of Muli in the western segment of the South Qilian Belt and consists of serpentinite, dunite, cumulate gabbro, basalt, plagiogranite, and chert. Field mapping results demonstrate that these units have been largely destroyed by faulting and generally occur as blocks/slices. They are tectonically interlayered with Upper Ordovician – Lower Silurian siliciclastic turbidite. Arc-ophiolite rocks are intruded by 470–450 Ma subduction-related granitoid plutons and are unconformably overlain by shallow marine to non-marine sediments of Permian-Jurassic age. Basalts show typical subduction-related calc-alkaline geochemical affinity, representing portions of an island arc. Geochemical results for plagiogranites and spinels from serpentinite demonstrate that the Muli arc-ophiolite complex represents a super-subduction zone(SSZ)-type ophiolite. U-Pb zircon data indicate formation associated with southward subduction of the Proto-Tethyan Ocean during a short interval between 539–522 Ma. Voluminous Late Ordovician-Early Silurian deep-water marine siliciclastic and volcaniclastic turbidites and volcanic arc rocks are exposed to the south of the Muli arc-ophiolite complex, whereas fluvial coarse-grained sandstones and conglomerates unconformably overlie the Cambrian-Middle Ordovician ophiolite-arc systems in the eastern South Qilian Belt. These indicate that closure of the Proto-Tethys Ocean was diachronous during the early Paleozoic. 展开更多
关键词 Muli arc-ophiolite complex SSZ-type ophiolite Proto-Tethys Ocean Qilian Orogen
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Impacts of Climate Change on Spatial and Temporal Distribution of Runoff and Sediment Yield in Xixi Watershed of Jinjiang Basin
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作者 Rong Kun 《Meteorological and Environmental Research》 CAS 2016年第3期34-37,共4页
Based on meteorologic data in Xixi Watershed from 1972 to 1979, the SWAT model was applied to simulate the response of runoff and sediment yield in Xixi Watershed to climate change under 24 kinds of climate change sce... Based on meteorologic data in Xixi Watershed from 1972 to 1979, the SWAT model was applied to simulate the response of runoff and sediment yield in Xixi Watershed to climate change under 24 kinds of climate change scenarios, and then the spatial and temporal distribution of change rates of the runoff and sediment were analyzed. The results showed that the runoff yield would increase with the increase of precipitation or decrease of temperature, and the sediment yield would increase with the increase of precipitation or increase of temperature; the runoff would be more sensitive to variations in precipitation than to variations in temperature, and precipitation change would lead to more obvious change in the run- off yield; the temporal distribution of change rates of the runoff and sediment yield would be uneven in the 12 months, and the variation trends of the two change rates in the 12 months would be accordant; the spatial distribution of change rates of the runoff and sediment yield would be uneven in the sub-watersheds, and the change rate of the runoff yield would be bigger in the sub-watersheds where the runoff yield in the basic period would be smaller. This study can provide decision-making basis for sustainable development of Jinjiang Basin. 展开更多
关键词 Climate change Runoff yield Sediment yield Spatial and temporal distribution SWAT model Xixi Watershed
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Landscape Destruction of the Potala Palace Square in Tibet
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作者 LIU Zhineng GUO Jianbin +2 位作者 ZHOU Peng HAO Wenyuan XU Jin 《Journal of Landscape Research》 2017年第4期63-66,共4页
This paper, with the Potala Palace Square as the object of study, uses the post occupancy method to carry out a field investigation in a joint manner of questionnaire survey, interviews and behavioral trails observati... This paper, with the Potala Palace Square as the object of study, uses the post occupancy method to carry out a field investigation in a joint manner of questionnaire survey, interviews and behavioral trails observation, so as to analyze the landscape destruction behavior of the Potala Palace Square. The results show that the existing problems in design and management of that square as well as the public are responsible for the destruction; male foreign tourists in all ages, who mostly are the unemployed, students and service employees, prove to be destructors. The Potala Palace Square is characterized by regionalism. Opinions on green effect, management and other options of inland public and local residents vary from one to another. Designers and the administrative department of the square are required to come up with countermeasures to avoid the destruction. In practical design, designers must comply with the thinking of "Design Must be for People" and natural ecological principles, and the administrative department should scientifically manage and maintain the square. 展开更多
关键词 The Potala Palace Square Landscape design Public at large VANDALISM Post occupancy method
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