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中兽医五行归类土行脉象季节新论(下)
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作者 王成 《四川畜牧兽医》 2001年第8期55-55,共1页
关键词 中兽医 王行归类 行脾 季节
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菩萨顶碑文
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作者 玄烨 《五台山研究》 1996年第1期31-31,共1页
菩萨顶碑文菩萨顶大文殊院碑文玄烨夫坤舆九壤,厥有名区。方《志》所标,莫之胜纪。若其峦陇绵邈,岩冈崇阻,萦纡窈窕,悠然远望,列峰竞秀,壁立霞驳,不可殚视,则惟清凉山之五台为最胜。五台并高数十里,如覆盂,如悬栈阁,如鹘摩... 菩萨顶碑文菩萨顶大文殊院碑文玄烨夫坤舆九壤,厥有名区。方《志》所标,莫之胜纪。若其峦陇绵邈,岩冈崇阻,萦纡窈窕,悠然远望,列峰竞秀,壁立霞驳,不可殚视,则惟清凉山之五台为最胜。五台并高数十里,如覆盂,如悬栈阁,如鹘摩天,如鳌脊出海。飞穹岫,飘渺超忽... 展开更多
关键词 文殊院 无何有之乡 菩萨 碑文 清凉山 玄烨 萦纡 土脉 驻跸 教律
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Research on the imaging of concrete defect based on the pulse compression technique 被引量:3
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作者 李长征 张碧星 +1 位作者 师芳芳 谢馥励 《Applied Geophysics》 SCIE CSCD 2013年第3期337-348,359,共13页
When the synthetic aperture focusing technology (SAFT) is used for the detection of the concrete, the signal-to-noise ratio (SNR) and detection depth are not satisfactory. Therefore, the application of SAFT is usu... When the synthetic aperture focusing technology (SAFT) is used for the detection of the concrete, the signal-to-noise ratio (SNR) and detection depth are not satisfactory. Therefore, the application of SAFT is usually limited. In this paper, we propose an improved SAFT technique for the detection of concrete based on the pulse compression technique used in the Radar domain. The proposed method first transmits a linear frequency modulation (LFM) signal, and then compresses the echo signal using the matched filtering method, after which a compressed signal with a narrower main lobe and higher SNR is obtained. With our improved SAFT, the compressed signals are manipulated in the imaging process and the image contrast is improved. Results show that the SNR is improved and the imaging resolution is guaranteed compared with the conventional short-pulse method. From theoretical and experimental results, we show that the proposed method can suppress noise and improve imaging contrast, and can also be used to detect multiple defects in concrete. 展开更多
关键词 Concrete defect LFM pulse compression SAFT SNR
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Regolith thickness modeling using a GIS approach for landslide distribution analysis, NW Himalayas 被引量:4
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作者 Muhammad BASHARAT Masood QASIM +3 位作者 Muhammad SHAFIQUE Nasir HAMEED Muhammad Tayyib RIAZ Muhammad Rustam KHAN 《Journal of Mountain Science》 SCIE CSCD 2018年第11期2466-2479,共14页
Regolith thickness is considered as a contributing factor for the occurrence of landslides.Although, mostly it is ignored because of complex nature and as it requires more time and resources for investigation. This st... Regolith thickness is considered as a contributing factor for the occurrence of landslides.Although, mostly it is ignored because of complex nature and as it requires more time and resources for investigation. This study aimed to appraise the role of regolith thickness on landslide distribution in the Muzaffarabad and surrounding areas, NW Himalayas.For this purpose regolith thickness samples were evenly collected from all the lithological units at representative sites within different slope and elevation classes in the field. Topographic attributes(slope, aspect, drainage, Topographic Wetness Index,elevation and curvature) were derived from the Digital Elevation Model(DEM)(12.5 m resolution).Arc GIS Model Builder was used to develop the regolith thickness model. Stepwise regression technique was used to explore the spatial variation of regolith thickness using topographic attributes and lithological units. The derived model explains about 88% regolith thickness variation. The model was validated and shows good agreement(70%) between observed and predicted values. Subsequently, the derived regolith model was used to understand the relationship between regolith thickness and landslide distribution. The analysis shows that most of the landslides were located within 1-5 m regolith thickness. However, landslide concentration is highest within 5-10 m regolith thickness, which shows that regolith thickness played a significant role for the occurrence of landslide in the studied area. 展开更多
关键词 REGOLITH GIS Regression LANDSLIDES HIMALAYAS
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Possible Collapse Mode for Slender Reinforced Concrete Plates Subjected to Blast Load
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作者 ZHANG Xin 杜修力 +1 位作者 CHEN Zhen ZENG Fanna 《Transactions of Tianjin University》 EI CAS 2008年第B10期500-503,共4页
This paper discusses the collapse mode of thin reinforced concrete (RC) plates sub-jected to blast load. To extend the well known plastic-mode method to analyze, not only perfect-plastic plates , but also RC plates, i... This paper discusses the collapse mode of thin reinforced concrete (RC) plates sub-jected to blast load. To extend the well known plastic-mode method to analyze, not only perfect-plastic plates , but also RC plates, it is needed to investigate the effect of material cracking on the collapse mode because the plate might have been cracked on both upper and lower surface before the plastic-mode fully develops, creating an unexpected type of collapse mode shape. A new fail-ure mode is proposed and verified by numerical analysis in this paper. The new mode is a result of the material cracking and has an un-negligible effect on the reaction mechanism of the RC plate to the blast load. 展开更多
关键词 pulse load flexural wave and reinforced concrete slab
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Relationship between High-quality Tea and the Geological Background in Qionglai Mountains 被引量:1
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作者 ZENG Qi-guo MA Xiao-jun +3 位作者 PENG Pei-hao LUO Fan WANG Yun HU Yao-wen 《Agricultural Science & Technology》 CAS 2011年第6期908-913,共6页
[Objective] Many strata emerge in the high-quality tea producing area in Qionglai Mountains,which belongs to Mesozoic Cretaceous(K),Mingshan Fm(E1-2mn)and Dayi conglomerate Team(N)of Cenozoic Tertiary System as well a... [Objective] Many strata emerge in the high-quality tea producing area in Qionglai Mountains,which belongs to Mesozoic Cretaceous(K),Mingshan Fm(E1-2mn)and Dayi conglomerate Team(N)of Cenozoic Tertiary System as well as Quaternary System(Q).Analysis on the migrating features of soil heavy metal from each stratum to tea leaves showed that the enrichment ability of elements was Cu>Cd>Zn>Ni>Hg>As>Cr>Pb.By comparing the soil background values with the soil base values of Sichuan hilly area and Chengdu economic region,it could be concluded that Cd,Hg,Mo,Pb and Se were enriched,and other metal elements existed at a level close to that of the comparing areas.The pH was a little acidic,and high quality tea cultivation could be developed here at present.With the increase of human activities,the environment of study area tends to deteriorate.Therefore,land planning and use should be reasonable.The government should control the environment nearby and prevent pollution. 展开更多
关键词 Qionglai Mountains High-quality tea Geological background
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Influence of Livestock Soil Eutrophication on Floral Composition in the Pyrenees Mountains 被引量:1
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作者 BADíA David MARTí Clara +3 位作者 SáNCHEZ José Ramón FILLAT Federico AGUIRRE Javier GóMEZ Daniel 《Journal of Mountain Science》 SCIE CSCD 2008年第1期63-72,共10页
Livestock behaviour in the Pyrenees includes free grazing and a long resting period that provokes the accumulation of dung and urine in some places,so-called camping areas. The aims of this study were (i) to analyze a... Livestock behaviour in the Pyrenees includes free grazing and a long resting period that provokes the accumulation of dung and urine in some places,so-called camping areas. The aims of this study were (i) to analyze any change in floral composition,and in nutritional and chemical contents of plants in a livestock camping area; and (ii) to relate the floral composition with soil chemical properties. In a linear transect,five sampling zones were established,from the centre of the camping area to the surrounding Nardus stricta-dominant pasture. The above ground plant biomass and the topsoil were sampled in each zone with 6 replicates per zone. Plant species were classified and weighed to calculate above ground biomass,nutritional and chemical contents,and Shannon diversity and evenness indices. Additionally,soils were sampled in two periods,at the beginning and at the end of grazing period. Soil available nutrients (nitrate,ammonium,phosphorus,potassium,calcium and magnesium),total nitrogen,organic carbon and pH were measured. Plant chemical contents (protein,lignin and others) were significantly related to the proportions of grasses,legumes and other plants; so,the protein content is positively correlated with legumes plant biomass while lignin content is negatively correlated with grasses. Both plant and soil nutrients increased linearly towards the centre of the camping area. However,the relationship among plant species richness,diversity and evenness relative to its position along the studied transect was bell-shaped. From the outskirts to the centre of the camping area,plants with low nutrient demand were progressively replaced by those with medium and high nutrients demand and by pioneers. Nardus stricta-dominant pasture has low plant diversity and plant nutrient content as well as a poor soil nutrient availability. The presence of the camping area introduced patches with more soil nutrients and new species in the large spatial scale. However at a small spatial scale,the strong soil nutrient concentration into the centre of the camping area reduced floral composition again. To ensure positive effects of camping areas on plant diversity,and to manage more effectively the nutrients returned to the soil,a reduction in the stocking rate should be pursued. 展开更多
关键词 Plant diversity species richness soil chemistry European mountains PYRENEES
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Anti-chloride permeability and anti-chloride corrodibility of a green high performance concrete admixture in concrete 被引量:1
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作者 郑永保 《Journal of Chongqing University》 CAS 2003年第2期43-45,共3页
The effects of green high performance concrete (GHPC) admixture on the anti-chloride permeability and anti- chloride corrodibility of concrete are studied by a series of experiments designed on the basis of the diffus... The effects of green high performance concrete (GHPC) admixture on the anti-chloride permeability and anti- chloride corrodibility of concrete are studied by a series of experiments designed on the basis of the diffusion principle and electro-chemical principle. The GHPC admixture consists of fly ash, gangue, slag, red mud, etc., of which the mass fraction of industrial residues is over 96 %. The anti-permeabilities and anti-corrodibilities of the tested GHPC and normal concrete (NC) are evaluated by the Diffusion Coefficients of chloride which was obtained by measuring the concentration of chloride in the tested systems by the voltage difference method. It is found that the adoption of GHPC admixture greatly improves the anti-chloride permeability and anti-chloride corrodibility by modifying the inner structure and contracting the porosity of concrete to the reduce considerably the diffusion rate of chloride. The admixture is desirable regarding its engineering performances as well as economical and environmental interests. 展开更多
关键词 green high performance concrete admixture anti-permeability anti-corrodibility voltage difference method
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Evaluating the Spatial Uncertainty of Future Land Abandonment in a Mountain Valley(Vicdessos, Pyrenees-France): Insights from Model Parameterization and Experiments
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作者 Thomas Houet Laure Vacquié David Sheeren 《Journal of Mountain Science》 SCIE CSCD 2015年第5期1095-1112,共18页
European mountains are particularly sensitive to climatic disruptions and land use changes.The latter leads to high rates of natural reforestation over the last 50 years. Faced with the challenge of predicting possibl... European mountains are particularly sensitive to climatic disruptions and land use changes.The latter leads to high rates of natural reforestation over the last 50 years. Faced with the challenge of predicting possible impacts on ecosystem services,LUCC models offer new opportunities for land managers to adapt or mitigate their strategies.Assessing the spatial uncertainty of future LUCC is crucial for the definition of sustainable land use strategies. However, the sources of uncertainty may differ, including the input parameters, the model itself, and the wide range of possible futures. The aim of this paper is to propose a method to assess the probability of occurrence of future LUCC that combines the inherent uncertainty of model parameterization and the ensemble uncertainty of the future based scenarios. For this purpose, we used the Land Change Modeler tool to simulate future LUCC on a study site located in the Pyrenees Mountains(France) and two scenarios illustrating two land use strategies. The model was parameterized with the same driving factors used for its calibration. The definition of ‘static vs. dynamic' and ‘quantitative vs.qualitative(discretized)' driving factors, and their combination resulted in four parameterizations. The combination of model outcomes produced maps of the spatial uncertainty of future LUCC. This work involves adapting the definition of spatial uncertainty in the literature to future-based LUCC studies. It goes beyond the uncertainty of simulation models by integrating the uncertainty of the future to provide maps to help decision makers and land managers. 展开更多
关键词 Land use Land cover SCENARIO Model Mountainous reforestation Land abandonment Landmanagement
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Constraints of REE and trace elements of high-pressure-veins and host rocks in western Tianshan on origin of deep fluids in paleosubduction zones 被引量:1
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作者 黄德志 高俊 戴塔根 《Journal of Central South University of Technology》 2005年第2期192-198,共7页
The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensi... The western Tianshan high-pressure(HP) metamorphic belt represents the paleosubduction mélange of paleozoic south Tianshan ocean between the Yili-central Tianshan and Tarim plates. High-pressure veins are extensively developed in this HP belt. Compared with normal mid-ocean ridge basalt(N-MORB), the high-pressure veins and host rocks are enriched in light rare earth elements(LREE) and incompatible elements. But high-pressure veins show a larger variation than host rocks in total REE abundance. On the trace element spidergram, all the samples are enriched in incompatible elements and show strong positive Pb anomaly relative to N-MORB. The array tendency lines of plots of the HP rocks have apparent slopes on diagram of m(Sr) vs m(Sr)/m(Zr), m(Li) vs m(Li)/m(Y) and (m(Ce)) vs m(Ce)/m(Pb), which indicates that the enrichment in LREE and incompatible elements relative to N-MORB of the HP-metamorphic rocks from western Tianshan is not attributed to magma evolution process of the protolith. High field strength elements, such as Nb, Ta, Ti, Zr and Hf, do not show negative anomaly relative to N-MORB, which is dissimilar to that of island arc basalts. Therefore, the enrichment in LREE and incompatible elements of the HP rocks is not attributed to the enrichment of the source of the protolith. The mass ratios of Rb to Ba, Ce to Pb, Nb to U and Ta to U of high-pressure veins and host rocks are intermediate of mid-ocean ridge basalt or oceanic island basalt and continental crust. The fluids in western Tianshan paleosubduction zones are mixtures of two sources, dehydration or devolatilization of host rocks and of subducted sediments. 展开更多
关键词 rare earth elements trace element fluid in paleosubduction zone high-pressure vein host rock western Tianshan
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A Review on Fiber Lasers 被引量:3
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作者 Lin Jintong Lu Dan Dai Yitang 《China Communications》 SCIE CSCD 2012年第8期1-15,共15页
After a half century of development, fiber laser has evolved from a concept to a great family penetrating into various fields of applications. This paper reviews the history and current development of fiber lasers, wi... After a half century of development, fiber laser has evolved from a concept to a great family penetrating into various fields of applications. This paper reviews the history and current development of fiber lasers, with topics covering both continuous wave and short pulse fiber lasers. Important issues such as the major rare earth dopants, fiber laser brightness, polarization effects, clad pumping technology, beam combination, mode locking and pulse shaping are discussed in this paper. 展开更多
关键词 fiber laser rare earth doped fiber continuous wave fiber laser ultra-short pulse fiber laser
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Effects of Topography and Land use on Woody Plant Species Composition and Beta Diversity in an Arid Trans-Himalayan Landscape, Nepal 被引量:5
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作者 Shishir PAUDEL Ole R VETAAS 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1112-1122,共11页
Distribution patterns of plant species are believed to be impacted by small-scale habitat heterogeneity. However, there have been few comparative studies examining how woody vegetation composition and diversity varies... Distribution patterns of plant species are believed to be impacted by small-scale habitat heterogeneity. However, there have been few comparative studies examining how woody vegetation composition and diversity varies with aspects of different orientations in the Trans-Himalayan region at a local scale. Here, we examined the effects of incoming solar radiation on variation in woody species composition and compared the diversity between the northeast- and southwest-facing slopes in a Trans-Himalayan valley of Nepal. We also examined the implicit interactions between slope orientation and land use in determining the compositional variations between the slopes. We selected two pairs of northeast- and southwest-facing slopes where the first pair has a similar land use and differs in exposure only(Pisang site) while the other pair has clear differences in land use in addition to slope exposure(Braka site). In each site, we sampled 72 plots(36 on each slope) in which the presence and absence of woody species, environmental variables, and disturbance were recorded. Correspondence Analysis(CA) results suggested that the woody species composition significantly varied between northeast- and southwest-facing slopes at both sites, and was significantly correlated with measured environmental variables such as radiation index, altitude, and canopy openness. In the Braka site,mean alpha diversity was significantly higher on southwest-facing slopes. In contrast, beta diversity and gamma diversity were greater on northeast-facing slopes at both sites. Our results suggest that topographic variables(e.g., radiation index) affect species composition between the slopes, likely due to their influence on small scale abiotic environmental variables. However, the effects of land use, such as livestock browsing/grazing may interact with the effects of slope exposure, effectively reducing differences in species composition within slopes but enhancing the differences in beta diversity between contrasting slopes in the Braka. We conclude that slope orientation and land use are important factors in structuring the woody species composition and diversity in the arid Trans-Himalayan region. We suggest that both environmental and land use variables should be taken into consideration in future studies on plant community structure along the cultural landscapes. 展开更多
关键词 Correspondence analysis Diversity Environmental gradients Himalaya Land use Topographic aspect Woody vegetation
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One patient of hepatic veno-occlusive disease with an increased cancer antigen-125 expression caused by misuse of Sedum aizoon
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作者 Siliang Wu 《TMR Clinical Research》 2018年第1期15-19,共5页
Nowadays hepatic veno-occlusive disease is mainly caused by Sedum aizoon in China,and its prognosis dependents on the dosage and courses of the Sedum aizoon treatment but lacks other objective indicators.There are a l... Nowadays hepatic veno-occlusive disease is mainly caused by Sedum aizoon in China,and its prognosis dependents on the dosage and courses of the Sedum aizoon treatment but lacks other objective indicators.There are a lot relationships between CA125 level and liver cirrhosis,this case had a obvious increased CA125 level in the serum,hydrothorax and ascites,following by the liver cirrhosis in a short time,and then died of upper gastrointestinal bleeding.By now we guess that CA125 level could forecast the liver cirrhosis following by hepatic veno-occlusive,which will become the prognosis of the hepatic veno-occlusive. 展开更多
关键词 Hepatic veno-occlusive disease Sedum aizoon Cancer antigen-125
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Surface Soil Effects Studies Based on HN Ratios of Microtremors at Kingston Metropolitan Area, Jamaica
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作者 Walter Salazar Lyndon Brown Garth Mannette 《Journal of Civil Engineering and Architecture》 2013年第10期1301-1322,共22页
The authors performed single mobile microtremor measurements at 218 sites at KMA (Kingston Metropolitan Area) with the objective of estimating the amplification effects due to the earthquake ground motion on the sur... The authors performed single mobile microtremor measurements at 218 sites at KMA (Kingston Metropolitan Area) with the objective of estimating the amplification effects due to the earthquake ground motion on the surface geology. The Fourier transform was applied to the most stationary parts of the triaxial wave motion recordings for each individual site and applied the traditional Nakamura technique, namely, the horizontal to vertical spectral ratio (H/V) to retrieve the predominant shear wave period of vibration of the soil profiles above the bedrock. The results yield predominant long periods of about 3.0-4.0 s in the port area and the waterfront, 1.0-2.0 s in the central part of Kingston, 0.3-1.0 s in Portmore and very stiff soil conditions in the surrounding area of the city. The results coincide fairly well with previous geological studies in the region, geotechnical data in boreholes, gravimetric measurements and strong motion recordings, suggesting a high degree of amplification of ground motion in the whole period range of engineering interest. Additionally, the authors obtained the liquefaction vulnerability factor Kg proposed by Nakamura based on the H/V ratio of microtremors. The results suggest that the port area, the waterfront and the Port Royal are highly susceptible to liquefaction. Finally, the authors obtained fundamental periods of vibration based on microtremor measurements on the roof and the basement of four important buildings in the KMA and indicated future lines of research employing ambient noise measurements on structures. 展开更多
关键词 MICROTREMORS Rayleigh and S-waves amplification factor fundamental period of vibration
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Nitric Oxide Emission Following Wetting of Dry Soils in Subtropical Humid Forests 被引量:2
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作者 LI De-Jun and WANG Xin-Ming 2 State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China) 《Pedosphere》 SCIE CAS CSCD 2009年第6期692-699,共8页
Information about soil nitric oxide (NO) emissions from subtropical forests is quite limited, and even less is known about the pulse emission of NO when wetting soils after a long period of dryness. In this study, w... Information about soil nitric oxide (NO) emissions from subtropical forests is quite limited, and even less is known about the pulse emission of NO when wetting soils after a long period of dryness. In this study, we measured NO fluxes following wetting of dry soft in a broadleaf forest and a pine forest in subtropical China. Large pulses of NO fluxes were observed after soil wetting in both forests. NO fluxes increased significantly within 0.5 h following wetting in both forests and reached peak 1 and 4 h after soil wetting in the pine forest and the broadleaf forest, respectively. In the broadleaf forest, averaged peak flux of NO pulses was 157 ng N m^-2 s^-1, which was 8 times the flux value before wetting, and in the pine forest, the averaged peak flux was 135 ng N m-2 s 1, which was 15.5 times the flux value before wetting. The total pulses-induced NO emissions during the dry season were roughly estimated to be 29.4 mg N m^-2 in the broadleaf forest and 22.2 mg N m^-2 in the pine forest or made up a proportion of 4.6% of the annual NO emission in the broadleaf forest and 5.3% in the pine forest. 展开更多
关键词 dry season flux. NO. pulse subtropical China
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Vegetation Geo-climatic Zonation in the Rocky Mountains, Northern Utah, USA 被引量:1
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作者 Antonin KUSBACH Helga VAN MIEGROET +1 位作者 Janis L.BOETTINGER James N.LONG 《Journal of Mountain Science》 SCIE CSCD 2014年第3期656-673,共18页
We developed a vegetation geo-climatic zonation incorporating the zonal concept, gradient and discriminant analysis in Wasatch Range, northern Utah, USA. Mountainous forest ecosystems were sampled and described by veg... We developed a vegetation geo-climatic zonation incorporating the zonal concept, gradient and discriminant analysis in Wasatch Range, northern Utah, USA. Mountainous forest ecosystems were sampled and described by vegetation, physiographic features and soil properties. The Snowpack Telemetry and National Weather Service Cooperative Observer Program weather station networks were used to approximate the climate of sample plots. We analysed vegetation and environmental data using clustering, ordination, classification, and ANOVA techniques to reveal environmental gradients affecting a broad vegetation pattern and discriminate these gradients. The specific objective was to assess and classify the response of the complex vegetation to those environmental factors operating at a coarse-scale climatic level. Ordination revealed the dominant role of regional, altitude-based climate in the area. Based on vegetation physiognomy, represented by five tree species, climatic data and taxonomic classification of zonal soils, we identified two vegetation geo-climatic zones:(1) a montane zone, with Rocky Mountain juniper and Douglas-fir; and(2) a subalpine zone, with Engelmann spruce and subalpine fir as climatic climax species. Aspen was excluded from the zonation due to its great ecological amplitude. We found significant differences between the zones in regional climate and landformgeomorphology/soils. Regional climate was represented by elevation, precipitation, and air and soil temperatures; and geomorphology by soil types. This coarse-scale vegetation geo-climatic zonation provides a framework for a comprehensive ecosystem survey, which is missing in the central Rocky Mountains of the United States. The vegetation-geoclimatic zonation represents a conceptual improvement on earlier classifications. This framework explicitly accounts for the influence of the physical environment on the distribution of vegetation within a complex landscape typical of the central Rocky Mountains and in mountain ranges elsewhere. 展开更多
关键词 Ecological classification Ecosystemsurvey Land classification Zonal concept Vegetation zone Vegetation geo-dimatic zone Climate change
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Study on Water-Soluble Organic Reducing Substances. I. Determination of Organic Reducing Substances by Differential Pulse Voltammetry
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作者 WUYOU-XIAN DINGCHANG-PU 《Pedosphere》 SCIE CAS CSCD 1991年第2期157-167,共11页
A new method was proposed for study of organic reducing substances in soils. According to the theoretical relationship between the voltammetric behaviors and reduction-oxidation reaction of reducing substances, the wo... A new method was proposed for study of organic reducing substances in soils. According to the theoretical relationship between the voltammetric behaviors and reduction-oxidation reaction of reducing substances, the working conditions of differential pulse voltammetry (d.p. v.) for determining the organic reducing substances produced during the processes of the anaerobic decomposition of plant materials were established with a glass carbon electrode as working electrode, 1 M Ag-AgCl electrode with large area as reference electrode, 0.2 M NH4AC as supporting electrolyte and pH buffer solution, pulse amplitude (AE) of 25 mV, scan rate at 2 mV·S-1and scan potential ranging from -0.5 to +1.2 voltage(vs. M Ag-AgCl). The peak current proportional to the concentration of reducing substances, and the characteristic peak potential of each organic reducing substance were regarded as the quantitative and qualitative base, respectively. These results obtained under the conditions mentioned above directly reflect both the reducing intensity and capacity of the organic reducing system in soils. 展开更多
关键词 differential pulse voltammetry organic reducing substances peak current peak potential
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Object-Based Analysis of Multispectral RS Data and GIS for Detection of Climate Change Impact on the Karakoram Range Northern Pakistan
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作者 Waquar U1 Hassan Chaudhary Ake Sivertun 《Journal of Environmental Science and Engineering(A)》 2015年第6期303-310,共8页
Changing climate has a great impact on northern area of Pakistan's environment and is more prone to environmental changes impacts than rest of the country due to its high elevation. However, melting glaciers effect n... Changing climate has a great impact on northern area of Pakistan's environment and is more prone to environmental changes impacts than rest of the country due to its high elevation. However, melting glaciers effect not only the local environment but also the whole country with frequent and heavy floods. Remote sensing (RS) from Satellites and Airplanes used in Geographical Information Systems (GIS) are technologies that can aid in understanding the on-going environmental processes. Furthermore, help researchers to observe, understand, forecast and suggest response to changes that occur. It can be natural disasters or man-made disasters and human induced factors. Still analysis accuracy issues play a vital role for the formulation of any strategy. To achieve better results, object based analysis methods have been tested. Various algorithms are developed by the analysts to calculate the magnitude of land cover changes. However, they must be evaluated for each environment that is under observation as mountainous areas. Here were object-based methods evaluated in comparison with pixel based. Landslides, soil moisture, soil permeability, snow cover and vegetation cover can be effectively monitored by those methods. 展开更多
关键词 Geographical information systems spatial data analysis object-based analysis of remote sensing data glacier degradation in Karakoram vegetation and snow cover.
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The influence of environmental variables on distribution patterns of Irano-Turanian forests in Alborz Mountains, Iran 被引量:1
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作者 Hooman RAVANBAKHSH Alireza MOSHKI 《Journal of Mountain Science》 SCIE CSCD 2016年第8期1375-1386,共12页
Topographic and edaphic variables are the main ecological factor determining species spatial variability on mountainous forests. A field study was performed in central Alborz to investigate how the edaphic and topogra... Topographic and edaphic variables are the main ecological factor determining species spatial variability on mountainous forests. A field study was performed in central Alborz to investigate how the edaphic and topographic parameters can affect the tree and shrub communities. Initially, 27 forest stands were identified and the homogeneous units were separated regarding physiognomy. In each single homogeneous unit, one random sample plot (1000 m^2) and totally 43 plots were established. In each plot, the presence and abundance of all trees and shrubs were recorded and four soil samples were taken from depths of 0-5 and 5-20 cm. Concerning classification results, eight different forest communities were identified. The lowest and highest soil pH values were observed in Malus orientalis and pistacia-Amygdalus communities, respectively. The water saturation percent of pure- and mixed Juniperus excelsa and Rhus coriaria was the highest amongst communities. The clay content was the highest in pure J.excelsa. The 0-5 organic matter and Nitrogen content in mixed J. excelsa were significantly higher than pure J. excelsa and other communities. The CCA (Canonical Correspondence Analysis) altitude, precipitation, pH, results indicated that the EC, SP, clay and CaCO3 are the most important factors determine the distribution of trees and shrub in central Alborz. 展开更多
关键词 Irano-Turanian Mountainouswoodlands Multivariate analysis Species-environment relationship
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Influence of Recycled Construction Materials Aggregate on Mechanical and Physical Properties of Concrete
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作者 Zainab Aamer Shamsulddin Rafaa Zair Jassim 《Journal of Civil Engineering and Architecture》 2016年第11期1244-1258,共15页
The main purpose of this research is to study the properties of re-use different types of construction materials such as PVC (polyvinylchloride) scraps, clay brick and recycled concrete as a partial replacement of c... The main purpose of this research is to study the properties of re-use different types of construction materials such as PVC (polyvinylchloride) scraps, clay brick and recycled concrete as a partial replacement of coarse aggregate. Different proportions (1%, 3%, 5% and 7%) by weight were used for PVC. scrap, (10%, 20%, 30%, and 40%) by weight were used for recycled concrete and (5%, 10%, 15%, and 20%) by weight were used for clay brick. Mechanical tests such as compressive and tensile strength tests and physical tests such as ultrasonic pulse velocity, bulk density, porosity, specific gravity and water absorption tests were done to the samples after curing in normal water for 28 days. Test results showed slightly degradation in mechanical and physical engineering properties of concrete specimens that used partial replacement of recycled concrete coarse aggregate, degradation increased with increasing of replacement but test results still closely to reference samples. Use of polyvinyl chloride in proportions not more than 5% as a partial replacement of coarse aggregates given acceptable results in comparison with reference samples but all test results degraded at 7% replacements. Test results of partial replacement of crushed brick coarse aggregates unacceptable and the range of degradation are wide because of increased (water: cement) ratio to improve the concrete workability. 展开更多
关键词 Recycled concrete PVC. chips clay brick environment benefits coarse aggregate replacements.
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