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家乡的三棵老柏树
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作者 陈慧君 《中国测绘》 2019年第3期77-78,共2页
难忘故乡那三棵参天的老柏树.我的故乡坐落在山上,又因陈姓居多,所以得名陈家山村.村庄就在半山腰的一块平地上依势而建,山下有一条螳螂河自西向东流去,河两岸是肥沃的良田.一条省道——博沂路沿河而行.山上有一眼长年不断的泉水,冬暖夏... 难忘故乡那三棵参天的老柏树.我的故乡坐落在山上,又因陈姓居多,所以得名陈家山村.村庄就在半山腰的一块平地上依势而建,山下有一条螳螂河自西向东流去,河两岸是肥沃的良田.一条省道——博沂路沿河而行.山上有一眼长年不断的泉水,冬暖夏凉,滋润着纯朴而善良的村民. 展开更多
关键词 依势 博沂路 螳螂 沿河 平地上 河自 故乡 滋润
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Co-occurrence Patterns of Above-ground and Below-ground Mite Communities in Farmland of Sanjiang Plain, Northeast China 被引量:7
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作者 LIN Lin GAO Meixiang +3 位作者 LIU Dong ZHANG Xueping WU Haitao WU Donghui 《Chinese Geographical Science》 SCIE CSCD 2014年第3期339-347,共9页
One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, litt... One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, little is known with regard to co-occurrence patterns in above-ground and below-ground communities. In this paper, we used a null model to test non-randomness in the structure of the above-ground and below-ground mite communities in farmland of the Sanjiang Plain, Northeast China. Then, we used four tests for non-randomness to recognize species pairs that would be demonstrated as significantly aggregated or segregated co-occurrences of the above-ground and below-ground mite communities. The pattern of the above-ground mite commu- nity was significantly non-random in October, suggesting species segregation and hence interspecific competition. Additionally, species co-occurrence patterns did not differ from randomness in the above-ground mite community in August or in below-ground mite com- munities in August and October. Only one significant species pair was detected in the above-ground mite community in August, while no significant species pairs were recognized in the above-ground mite community in October or in the below-ground mite communities in August and October. The results indicate that non-randomness and significant species pairs may not be the general rule in the above-ground and below-ground mite communities in farmland of the Sanjiang Plain at the fine scale. 展开更多
关键词 above-ground mite below-ground mite mite communities co-occurrence patterns interspecific competition species pairassociations
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Effects of Nitrogen Addition on Plant Functional Traits in Freshwater Wetland of Sanjiang Plain,Northeast China 被引量:14
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作者 MAO Rong ZHANG Xinhou SONG Changchun 《Chinese Geographical Science》 SCIE CSCD 2014年第6期674-681,共8页
To clarify the responses of plant functional traits to nitrogen(N) enrichment, we investigated the whole-plant traits(plant height and aboveground biomass), leaf morphological(specific leaf area(SLA) and leaf dry mass... To clarify the responses of plant functional traits to nitrogen(N) enrichment, we investigated the whole-plant traits(plant height and aboveground biomass), leaf morphological(specific leaf area(SLA) and leaf dry mass content(LDMC)) and chemical traits(leaf N concentration(LNC) and leaf phosphorus(P) concentration(LPC)) of Deyeuxia angustifolia and Glyceria spiculosa following seven consecutive years of N addition at four rates(0 g N/(m2·yr), 6 g N/(m2·yr), 12 g N/(m2·yr) and 24 g N/(m2·yr)) in a freshwater marsh in the Sanjiang Plain, Northeast China. The results showed that, for both D. angustifolia and G. spiculosa, N addition generally increased plant height, leaf, stem and total aboveground biomass, but did not cause changes in SLA and LDMC. Moreover, increased N availability caused an increase in LNC, and did not affect LPC. Thus, N addition decreased leaf C∶N ratio, but caused an increase in leaf N∶P ratio, and did not affect leaf C∶P ratio. Our results suggest that, in the mid-term, elevated N loading does not alter leaf morphological traits, but causes substantial changes in whole-plant traits and leaf chemical traits in temperate freshwater wetlands. These may help to better understand the effects of N enrichment on plant functional traits and thus ecosystem structure and functioning in freshwater wetlands. 展开更多
关键词 nitrogen addition Deyeuxia angustifolia Glyceria spiculosa leaf chemical traits leaf morphological traits whole-planttraits Sanjiang Plain
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Study on the Degradation Trend of Ryegrass-White Clover Artificial Grassland 被引量:12
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作者 张建波 李相林 +4 位作者 万里强 陈瑞祥 赵相勇 陈伟 陈国南 《Agricultural Science & Technology》 CAS 2009年第1期26-28,88,共4页
[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass (Lolium perenne) - white clover ( Trifolium repens) artificial grassland in Maiping Townsh... [Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass (Lolium perenne) - white clover ( Trifolium repens) artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas (area around the sheep shed, hilltop, hillside, flatland at the foot of the hill) were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass ( Paspalum dilatatum Poir. ) -Indian lovegrass ( Eragrostis pilosa) and dallis grass - cogongrass [ Imperata cylindrica ( Linn. ) Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum ( Chrysanthemum coronarium L. ) and knotgrass ( Paspalum distichum L. ). [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China. 展开更多
关键词 Ryegrass Lolium perenne) White clover( Trifolium repens) Artificial grassland DEGRADATION
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Causes of Land Loss in Tuvalu,a Small Island Nation in the Pacific
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作者 XUEChunting 《Journal of Ocean University of China》 SCIE CAS 2005年第2期115-123,共9页
Studies on land loss in Tuvalu reveal the following findings. Although both sea level rise and coastal erosion can cause land loss in the tropic Pacific oceanic islands, their mechanisms are different. When sea level ... Studies on land loss in Tuvalu reveal the following findings. Although both sea level rise and coastal erosion can cause land loss in the tropic Pacific oceanic islands, their mechanisms are different. When sea level rises, the low elevation coastal zone submerges and the erosion datum plane rises, the beach process progresses normally as always, resulting in no beach sediment coarsening. When the sea level is stable, coastal erosion removes finer sediment from reef flat, beach and land, resulting in beach sediment coarsening. The human-induced coastal erosion in the tropic Pacific oceanic islands has the following features. 1) Erosion occurs or intensifies immediately after inappropriate human activities. 2) It occurs near the places having human activities and places related to the above places in sediment supply. 3) It often occurs on original prograding or stable coasts (on lagoon coasts for atolls) because there are more coastal engineering projects and other human activities on such coasts. 4) It is chronic, covering a long period of time. The coastal geological events in Tuvalu islands do not accord with the features resulted from sea level rise but do accord with the features resulted from coastal erosion, particularly from human-induced erosion. The land loss in Tuvalu is mainly caused by inappropriate human activities including coastal engineering and aggregate mining, and partly caused by cyclones. Moreover, all recent measurements (satellite altimetry,thermosteric sea level data and tide observations) so far have not been able to verify any sea level rise around Tuvalu islands. 展开更多
关键词 sea level rise land loss coastal erosion artificial channel aggregatemining
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Numerieal Prediction of Storm Surge in the Qingdao Area Under the Impact of Climate Change 被引量:3
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作者 FENG Jianlong JIANG Wensheng BIAN Changwei 《Journal of Ocean University of China》 SCIE CAS 2014年第4期539-551,共13页
A typhoon-induced storm surge simulation system was developed for the Qingdao area, including a typhoon diagnostic model for the generation of wind and pressure fields and a 2D Advanced Circulation(ADCIRC) model for s... A typhoon-induced storm surge simulation system was developed for the Qingdao area, including a typhoon diagnostic model for the generation of wind and pressure fields and a 2D Advanced Circulation(ADCIRC) model for simulating the associated storm surge with a 200 m resolution along the Qingdao coastline. The system was validated by an extreme surge event Typhoon Mamie(8509) and the parameters of Typhoon Mamie were used to investigate the sensitivity of typhoon paths to Qingdao storm surges with four selected paths: the paths of Typhoons Mamie(8509), Opal, 3921 and 2413, the selection being made according to their relative position to Qingdao. Experiments based on the Typhoon Mamie(8509) storm surge were also conducted to study the possible influences of future climate changes, including the sea level rise and sea surface temperature(SST) rise, on storm surges along the Qingdao coast. Storm surge conditions under both present day and future(the end of the 21 st century) climate scenarios associated with the four selected paths were simulated. The results show that with the same intensity, when typhoons follow the paths of 3921 and 2413, they would lead to the most serious disasters in different areas of Qingdao. Sea level and SST affect storm surges in different ways: sea level rise affects storm surge mainly through its influence on the tide amplitude, while the increased SST has direct impact on the intensity of the surges. The possible maximum risk of storm surges in 2100 in the Qingdao area caused by typhoons like Mamie(8509) was also estimated in this study. 展开更多
关键词 storm surge typhoon path climate change Qingdao
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The "Silk Road Economic Belt" and the "China Dream" Relationship: A Strategy or Tactic
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作者 Xing Li Wan Wang 《Sociology Study》 2015年第3期169-175,共7页
The "Silk Road Economic Belt" and the "China Dream" are tightly linked together rather than isolated from each other. The essence of the construction of the "Silk Road Economic Belt" is to give equal considerati... The "Silk Road Economic Belt" and the "China Dream" are tightly linked together rather than isolated from each other. The essence of the construction of the "Silk Road Economic Belt" is to give equal considerations to both the East and the West, paying equal attentions to the North and the South, while balancing the land and the sea and connecting domestic with foreign. This is the innovation and priority of China's peripheral diplomacy as well as a strategic support and tactical guarantee of the "China Dream". The "Silk Road Economic Belt" is constructed to make history serve reality; it exchanges economy for politics, space on land for time at sea, and balances a weakness in sea power with superiority in land power. Instead of simply replicating the Silk Road, the "Silk Road Economic Belt" possesses a broader realm and a richer context. Moreover, this is China's ultimate strategy and profound tactical conception facing toward the future. 展开更多
关键词 "Silk Road Economic Belt" "China Dream" the center of Eurasia STRATEGY tactic
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Mean Sea Level Changes near Weizhou Island from 1969 to 2010
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作者 ZHENG Zhaoyong LI Guangxue +1 位作者 TANG Chaolian ZHOU Xiong 《Journal of Ocean University of China》 SCIE CAS 2014年第3期369-374,共6页
Tidal data from Weizhou, Zhapo, and Shanwei stations between 1969 and 2010 and from five gauging stations in the western Pacific Ocean provided by PSMSL, and the global mean sea level data recorded between December 19... Tidal data from Weizhou, Zhapo, and Shanwei stations between 1969 and 2010 and from five gauging stations in the western Pacific Ocean provided by PSMSL, and the global mean sea level data recorded between December 1992 and December 2010 by TOPEX and Jason satellites were compiled and analyzed. The results show that the perennial mean sea level near Weizhou Island is 211.7 cm(relative to the water gauge zero), and the relative mean sea level rising rate is 2.2 mm yr-1 from 1969 to 2010, which is consistent with the relative mean sea level rising rate recorded at other gauging stations in the western Pacific regions and with the global mean sea level rising rate. The absolute mean sea level rising rate at Weizhou Island is 3.0 mm yr-1 from 1993 to 2010, also conforming with the global mean sea level rising rate(3.1±0.4 mm yr-1) during the same time period. The highest annual tide level at Weizhou Island has a rising rate of 4.6 mm yr-1 and shows a 20-year quasi-periodic variation from 1966 to 2010. The primary cause of the mean sea level rising is global warming. 展开更多
关键词 CLIMATOLOGY mean sea level change global climate change Weizhou Island
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Study on the Seismic Fortification Criteria of Offshore Platforms in the Bohai Sea
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作者 Lv Yuejun Peng Yanju +1 位作者 Wang Junqin Sha Haijun 《Earthquake Research in China》 2013年第1期109-120,共12页
This paper analyzes the seismicity and seismic risk distribution in the Bohai Sea. Based on the seismic design parameters of 46 platforms in the Bohai Sea, a statistic analysis is made on the ratios of the peak accele... This paper analyzes the seismicity and seismic risk distribution in the Bohai Sea. Based on the seismic design parameters of 46 platforms in the Bohai Sea, a statistic analysis is made on the ratios of the peak accelerations for different probability levels. In accordance with the two-stage design method, a scheme of two design seismic levels is proposed, and two fortification goals are established respectively for strength level earthquakes and ductility level earthquakes. Through analogy and comparison to the Chinese seismic code for buildings, it is proposed that the probability level for the strength and ductility level earthquakes takes return periods of 200a and 1000~2500a respectively, and we further expounded on its rationality. Finally, the fortification parameters in the sub-regions of Bohai Sea area are given in the light of seismic risk zonation and ground motion division. This article is a summary of experiences from many years of offshore platform seismic fortification work, and an exploratory study on the seismic fortification standards of offshore platforms in China, which may provide some references for the establishment of the standard. 展开更多
关键词 Bohai Sea Offshore platform Seismic fortification level
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Prediction of China's Submerged Coastal Areas by Sea Level Rise due to Climate Change 被引量:5
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作者 ZUO Juncheng YANG Yiqiu +2 位作者 ZHANG Jianli CHEN Meixiang XU Qing 《Journal of Ocean University of China》 SCIE CAS 2013年第3期327-334,共8页
Based on the simulation with the Ocean-Atmosphere Coupled Model CCSM and Ocean Model POP under the green- house gas emission scenario of the IPCC SRES A2 (IPCC, 2001), and on the earth crust subsidence and glacier m... Based on the simulation with the Ocean-Atmosphere Coupled Model CCSM and Ocean Model POP under the green- house gas emission scenario of the IPCC SRES A2 (IPCC, 2001), and on the earth crust subsidence and glacier melting data, the relative sea level change is obtained along the coast of China in the 21 st century. Using the SRTM elevation data the submergence of coastal low land is calculated under the extreme water level with a 100-year retum period. The total flooding areas are 98.3× 10^3 and 104.9× 10^3 km2 for 2050 and 2080, respectively. For the three regions most vulnerable to extreme sea level rise, i.e., the coast of Bohai Bay, the Yangtze River Delta together with neighboring Jiangsu Province and northern Zhejiang Province, and the Pearl River Delta, the flooded areas are 5.0× 10^3, 64.1×10^3 and 15.3 × 10^3 km2 in 2050 and 5.2 × 10^3, 67.8×10^3 and 17.2 × 10^3 km2 in 2080, respectively. 展开更多
关键词 sea level rise submerged area extreme water level of 100-year recurrence 1985 National Height Datum
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Average iron isotopic compositions of the upper continental crust:constrained by loess from the Chinese Loess Plateau 被引量:3
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作者 Yingzeng Gong Ying Xia +1 位作者 Fang Huang Huimin Yu 《Acta Geochimica》 EI CAS CSCD 2017年第2期125-131,共7页
Iron isotopic composition of the upper continental crust(UCC) is critical for understanding Fe mobilization and migration through the Earth. Because rocks exposed at Earth's surface have heterogeneous δ^(56)Fe, f... Iron isotopic composition of the upper continental crust(UCC) is critical for understanding Fe mobilization and migration through the Earth. Because rocks exposed at Earth's surface have heterogeneous δ^(56)Fe, finegrained clastic sediments can be used to estimate the average composition of UCC. In this study, we report δ^(56)Fe of loess-paleosol sequences from Yimaguan, Chinese Loess Plateau(CLP), to constrain the average Fe isotopic composition of UCC. The loess-paleosol sequences in this area formed in glacial-interglacial cycles and are characterized by varying degrees of weathering. Our data show that the loess-paleosol layers have extremely homogeneous Fe isotopic compositions with δ^(56)Fe ranging from 0.06‰ to 0.12‰, regardless of variations in the major element composition and weathering intensity. Our study indicates that since Fe isotopes are not significantly fractionated during loess deposition, the loess can be regarded as representative of UCC. It follows that the average δ^(56)Fe of UCC is 0.09‰± 0.03‰(2SD), consistent with previous estimates based on igneous rock data. 展开更多
关键词 Yimaguan LOESS Fe isotopes Uppercontinental crust
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Development of Coastal Vulnerability Index for the Kingdom of Bahrain
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作者 Sabah S. Aljenaid 《Journal of Earth Science and Engineering》 2012年第6期328-336,共9页
The CVI (coastal vulnerability index) was developed and used to assess the vulnerability of the coastline of the Kingdom of Bahrain main islands to future SLR (sea level rise). A total of 717 km of the coastline w... The CVI (coastal vulnerability index) was developed and used to assess the vulnerability of the coastline of the Kingdom of Bahrain main islands to future SLR (sea level rise). A total of 717 km of the coastline was evaluated. Six spatial factors acting on the coastal area: erosion/accretion patterns (shoreline change), topography (elevation above mean sea level), geology, geomorphology, slope, and mean sea level rise were incorporated and ranked to develop the CVI. This index was classified into four levels of vulnerability: low, moderate, high, and very high. Vulnerable hotspots are located along the central portions of the western and eastern coastlines. The vulnerability of these areas is mostly driven by their characteristically shallow coastal slopes, low elevations, and erosion-prone nature of the sandy soils presents, comprising about 54 km of the studied shoreline. Another 33 km of coastline were classified as highly vulnerable and located along the eastern coast. In addition, the western coast of the southern tip of the main island (Bahrain) was also classified as a highly vulnerable shoreline. Twenty-two km was classified as the moderate vulnerable. The remaining coastal areas were classified as low to moderately vulnerable comprising about 608 km of the total length of the coastline. Identifying those hotspots susceptible to SLR is essential for more effective coastal zone management and to help in reducing the impacts of SLR on both infrastructure and human beings. 展开更多
关键词 CV1 (coastal vulnerability index) SLR (sea level rise) vulnerability.
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Global Distribution of Thermosteric Contribution to Sea Level Rising Trend 被引量:1
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作者 ZUO Juncheng DU Ling +1 位作者 ZHANG Jianli CHEN Meixiang 《Journal of Ocean University of China》 SCIE CAS 2010年第3期199-209,共11页
The sea level derived from TOPEX/Poseidon (T/P) altimetry data shows prominent long term trend and inter-annual variability. The global mean sea level rising rate during 1993-2003 was 2.9mm a^-1. The T/P sea level t... The sea level derived from TOPEX/Poseidon (T/P) altimetry data shows prominent long term trend and inter-annual variability. The global mean sea level rising rate during 1993-2003 was 2.9mm a^-1. The T/P sea level trend maps the geographical variability. In the Northern Hemisphere (15°-64°N), the sea level rise is very fast at the mid-latitude (20°-40°N) but much slower at the high-latitude, for example, only 0.5 mm a^-1 in the latitude band 40°-50°N. In the Southern Hemisphere, the sea level shows high rising rate both in mid-latitude and high-latitude areas, for example, 5.1 mm a^-1 in the band 40°- 50°S. The global thermosteric sea level (TSL) derived from Ishii temperature data was rising during 1993-2003 at a rate of 1.2 mm a^-1 and accounted for more than 40% of the global T/P sea level rise. The contributions of the TSL distribution are not spatially uniform; for instance, the percentage is 67% for the Northern Hemisphere and only 29% for the Southern Hemisphere (15°-64°S) and the maximum thermosteric contribution appears in the Pacific Ocean, which contributes more than 60% of the global TSL. The sea level change trend in tropical ocean is mainly caused by the thermosteric effect, which is different from the case of seasonal variability in this area. The TSL variability dominates the T/P sea level rise in the North Atlantic, but it is small in other areas, and shows negative trend at the high-latitude area (40°-60°N, and 50°-60°S). The global TSL during 1945-2003 showed obvious rising trend with the rate of about 0.3 mm a-l and striking inter-annual and decadal variability with period of 20 years. In the past 60 years, the Atlantic TSL was rising continuously and remarkably, contributing 38% to the global TSL rising. The TSL in the Pacific and Indian Ocean rose with significant in- ter-annual and decadal variability. The first EOF mode of the global TSL from Ishii temperature data was the ENSO mode in which the time series of the first mode showed steady rising trend. Among the three oceans, the first mode of the Pacific TSL presented the ENSO mode; there was relatively steady rising trend in the Atlantic Ocean, and no dominant mode in the Indian Ocean. 展开更多
关键词 thermosteric effect sea level trend T/P altimeter spatial distribution
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Inventory and Geometrical Changes in Small Glaciers Covering Three Northern Patagonian Summits Using Remote Sensing and GIS Techniques
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作者 Alfonso Fernández José Araos Jorge Marín 《Journal of Mountain Science》 SCIE CSCD 2010年第1期26-35,共10页
In the last few decades, a large quantity of research has been performed to elucidate the current behavior of glaciers in southern Chile, especially with respect to the volumetric changes in the outlets of the Norther... In the last few decades, a large quantity of research has been performed to elucidate the current behavior of glaciers in southern Chile, especially with respect to the volumetric changes in the outlets of the Northern and Southern Patagonian Icefields (NPI and SPI, respectively). Calculations have shown a generalized thinning and withdrawal, which greatly contributes to the increase in sea level attributed to the ice melt from non-polar glaciers. However, these icefields are surrounded by many small icecaps, which have'yet to be studied in detail. A precise estimation of the volume of ice located in these mountain chains could provide new information with respect to this area's exact contribution to the increase in sea level. Thus, this study presents an inventory of relatively small Northern Patagonian glaciers in the surrounding of the three summits: Mount Queulat, and the Maca and Hudson volcanoes. The study used remote sensing techniques in a GIS environment to determine the margins, surface areas, thickness changes and hypsometry for the glaciated zones. Landsat images from different dates were analyzed using standard band ratio and screen delineation techniques. Additionally, digital elevation models from different dates were compared using map algebra, calculating thickness changes. Based on the results, we propose that there are important volumetric changes in the glaciers studied, whichcould be explained by precipitation trends in a general context, and an influence of the glaciers' sizes in some local response. Therefore, we suggest the exact contribution of the Patagonia to the increase in sea level corresponds to a regional pattern rather than just the behavior of a single ice field. 展开更多
关键词 Glacier inventory thickness change digital elevation model morphometric measurement
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Neighborhood and Adaptation to Climate Change: A Case Study of Adelaide
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作者 Premita Paudyal Alpana Sivam 《Journal of Civil Engineering and Architecture》 2010年第12期39-46,共8页
Extreme weather is expected to be widespread by the year 2100 due to changes in precipitation and temperature, and rising sea levels. It is expected that there will be more heat waves, floods, bush fires, coastal eros... Extreme weather is expected to be widespread by the year 2100 due to changes in precipitation and temperature, and rising sea levels. It is expected that there will be more heat waves, floods, bush fires, coastal erosion and drought. Unfortunately, Australia is vulnerable to climate change due its hot and dry climate and as the driest state; changes are already being felt in South Australia. There is an urgent need to start adapting to climate change to cope with present and predicted climate change in the future by changing or adjusting building regulations, land use plans, and land subdivision regulations. This paper aims to provide design guidelines for adaptation to climate change at the neighborhood level. A case study method was adopted to achieve the aim of this paper. The study was conducted in two stages. The first stage presents the current design of neighborhood and its adopted design parameters for climate change. The second part provides the design guidelines for adaptation to climate change at the neighborhood level. The case study has a well oriented grid iron layout that serves as the basis of orienting and sitting future buildings that can adapt to climate change. However, the orientation of roads is good, it will be necessary to reconfigure elements of landscaping and built environment in order to address climate change in built environment by modifying design elements. 展开更多
关键词 Climate change NEIGHBORHOOD ADAPTATION energy efficiency building design SUBDIVISION LANDSCAPE planning.
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Development of Breakup Model for Large Eddy Simulation of Diesel Spray
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作者 Tatsunori Fujii Koji Kitaguchi +2 位作者 Soichi Hatori Tsukasa Hori Jiro Senda 《Journal of Energy and Power Engineering》 2013年第12期2312-2320,共9页
Diesel spray is injected at high pressure. So, upper stream region of spray is high Weber number condition. However, even if the fuel is injected at high pressure, the downstream region of spray is corresponding to re... Diesel spray is injected at high pressure. So, upper stream region of spray is high Weber number condition. However, even if the fuel is injected at high pressure, the downstream region of spray is corresponding to relatively low Weber number condition. Thus, KH (Kelvin-Helmholtz) model modeled for high Weber number conditions and MTAB (modified Taylor analogy breakup) model are used for primary and secondary breakup processes respectively. This study is focused on the development of new hybrid breakup model The calculations are performed by LES (large eddy simulation) incorporated into KIVA code. LES of non-evaporating diesel spray are performed using KH & RT (Rayleigh-Taylor) model, MTAB model and KH-MTAB model. Then, LES with these models were compared with experimental results. As the result, the availability of KH-MTAB model is showed. It is found that KH-MTAB is good agreement with experimental results of penetration and SMD (Sauter mean diameter) in relatively low density conditions. 展开更多
关键词 Diesel spray spray structure large eddy simulation breakup model KH-MTAB model.
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Validation of a Critical Nitrogen Curve for Summer Maize in the North China Plain 被引量:14
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作者 YUE Shan-Chao SUN Fu-Lai +5 位作者 MENG Qing-Feng ZHAO Rong-Fang LI Fei CHEN Xin-Ping ZHANG Fu-Suo CUI Zhen-Ling 《Pedosphere》 SCIE CAS CSCD 2014年第1期76-83,共8页
The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A c... The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A critical N dilution curve of N_c=34.0W^(-0.37),where W is the aboveground biomass(Mg DM ha^(-1))and N_c the critical N concentration in aboveground dry matter(g kg^(-1)DM),was developed for spring maize in Europe.Our objectives were to validate whether this European critical N dilution curve was appropriate for summer maize production in the North China Plain(NCP)and to develop a critical N dilution curve especially for summer maize production in this region.In total 231 data points from 16 experiments were used to test the European critical N dilution curve.These observations showed that the European critical N dilution curve was unsuitable for summer maize in the NCP,especially at the early growth stage.From the data obtained,a critical N dilution curve for summer maize in the NCP was described by the equation of N_c=27.2W^(-0,27),when aboveground biomass was between 0.64 and 11.17 Mg DM ha^(-1).Based on this curve,more than 90%of the data for the N deficiency supply treatments had an N nutrition index(NNI)<1 and 92%of the data for the N excess supply treatments had an NNI>1. 展开更多
关键词 critical N dilution curve N nutrition index optimal N management plant-based N diagnostic indicator
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Evaluation of farmland losses from sea level rise and storm surges in the Pearl River Delta region under global climate change 被引量:2
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作者 康蕾 马丽 刘毅 《Journal of Geographical Sciences》 SCIE CSCD 2016年第4期439-456,共18页
The Pearl River Delta on China's coast is a region that is seriously threatened by sea level rise and storm surges induced by global climate change, which causes flooding of large areas of farmland and huge agricu... The Pearl River Delta on China's coast is a region that is seriously threatened by sea level rise and storm surges induced by global climate change, which causes flooding of large areas of farmland and huge agricultural losses. Based on relevant research and experience, a loss evaluation model of farmland yield caused by sea level rise and storm surges was established. In this model, the area of submerged farmland, area of crops, and per unit yield of every type of crop were considered, but the impact of wind, flooding time, changes in land use and plant structure were not considered for long-term prediction. Taking the Pearl River Delta region in Guangdong as the study area, we estimated and analyzed the spatial distribution and loss of farmlands for different scenarios in the years 2030, 2050, and 2100, using a digital elevation model, land-use data, local crop structure, rotation patterns, and yield loss ratios for different submerged heights obtained from field survey and questionnaires. The results show that the proportion of submerged farmlands and losses of agricultural production in the Pearl River Delta region will increase gradually from 2030 to 2100. Yangjiang, Foshan, and Dongguan show obvious increases in submerged farmlands, while Guangzhou and Zhuhai show slow increases. In agricultural losses, vegetables would sustain the largest loss of production, followed by rice and peanuts. The greatest loss of rice crops would occur in Jiangmen, and the loss of vegetable crops would be high in Shanwei and Jiangmen. Although losses of peanut crops are generally lower, Jiangmen, Guangzhou, and Shanwei would experience relatively high losses. Finally, some measures to defend against storm surges are suggested, such as building sea walls and gates in Jiangmen, Huizhou, and Shanwei, enforcing ecological protection to reduce destruction from storm surges, and strengthening disaster warning systems. 展开更多
关键词 sea level rise storm surge submerged farmland loss of farmland Pearl River Delta
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