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东北型中蜂的生活习性及管理要点
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作者 徐士磊 石丽萍 邓德万 《中国蜂业》 2007年第1期28-29,共2页
我国的野生中蜂主要生活在雨水较多,空气湿润、蜜粉源植物种类较多的山区、丘陵。在树洞、岩缝、土穴等防风避雨处营造巢穴。中蜂在长期的生存繁衍过程中,形成了特有的生活习性。因为蜜蜂空中交尾的特性及未进行系统的科学育种工作,... 我国的野生中蜂主要生活在雨水较多,空气湿润、蜜粉源植物种类较多的山区、丘陵。在树洞、岩缝、土穴等防风避雨处营造巢穴。中蜂在长期的生存繁衍过程中,形成了特有的生活习性。因为蜜蜂空中交尾的特性及未进行系统的科学育种工作,虽然有上千年的家养史,仍未改变其原始野性。 展开更多
关键词 生活习性 野生中蜂 管理要点 东北型中蜂 植物种类 育种工作 蜜粉源 丘陵
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新东北ZF6A-252型断路器测速专用辅助装置的研制
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作者 杨钧豪 《电气开关》 2023年第5期101-102,106,共3页
对开关机械特性测试的重要性进行阐述,针对新东北ZF6A-252断路器HMB型液压弹簧操作机构位置狭小无法安装常规测速传感器的问题进行研究,设计一种专用测速辅助装置解决该问题,提高了该型号断路器的机械特性试验数据的有效性与准确性,充... 对开关机械特性测试的重要性进行阐述,针对新东北ZF6A-252断路器HMB型液压弹簧操作机构位置狭小无法安装常规测速传感器的问题进行研究,设计一种专用测速辅助装置解决该问题,提高了该型号断路器的机械特性试验数据的有效性与准确性,充分保障了电网的安全稳定运行。 展开更多
关键词 东北ZF6A-252 机械特性测试 测速辅助装置
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东北边境口岸型县域产业结构发展研究 被引量:3
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作者 王楠 张本明 《开发研究》 CSSCI 2008年第3期103-105,共3页
东北边境口岸型县域的产业结构发展不仅影响到所在省、市及东北经济区的未来发展模式,更关系到新时期国家的安全与发展问题,具有重要现实研究意义。通过分析现阶段产业结构的模式与特点,指出口岸经济与县域经济虽呈正相关,但关联度较差... 东北边境口岸型县域的产业结构发展不仅影响到所在省、市及东北经济区的未来发展模式,更关系到新时期国家的安全与发展问题,具有重要现实研究意义。通过分析现阶段产业结构的模式与特点,指出口岸经济与县域经济虽呈正相关,但关联度较差,三次产业非均衡发展比例不断提高,县域产业结构较单一,抗风险能力弱。并提出产业结构调整的四项措施。 展开更多
关键词 东北边境口岸县域 产业结构 口岸经济 关联
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滇东北铅锌(银)矿矿集区成矿规律研究 被引量:5
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作者 杨宁 薛步高 《云南地质》 2012年第1期1-11,共11页
滇东北铅锌(银)矿集区,是云南省重要的铅锌(银)产地,含6个矿带,总计上表(截止2008年底)Pb+Zn 766.9 180万t(Pb 291.0723万t、Zn 475.8475万t),占全省上表Pb+Zn储量的19.36%。其主体地质特征与MVT型相似,但也存在差异,可称为MVT型含氟、... 滇东北铅锌(银)矿集区,是云南省重要的铅锌(银)产地,含6个矿带,总计上表(截止2008年底)Pb+Zn 766.9 180万t(Pb 291.0723万t、Zn 475.8475万t),占全省上表Pb+Zn储量的19.36%。其主体地质特征与MVT型相似,但也存在差异,可称为MVT型含氟、钡的新亚类———滇东北型。 展开更多
关键词 铅锌矿床 成矿流体 赋矿环境 东北型 云南滇东北
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东北的两栖类
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作者 温世生 刘明玉 宋淑香 《辽宁大学学报(自然科学版)》 CAS 1994年第1期66-70,共5页
本文报导了东北区(包括沿海岛屿)两栖类分布的情况.辽宁省两栖类的分布具有东北区与华北区之间过渡的性质;中部吉林省的两栖类,反映了东北区两栖类分布的一般特点.气温为东北区两栖动物分布的主要限制因子.
关键词 分布 东北型 两栖类
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四款新型拖拉机
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作者 苏机 《农家致富》 2018年第3期25-25,共1页
一、东方红LX1504拖拉机作为国产"老大哥",东方红这一款LX1504拖拉机颇受消费者喜爱。作为中国一拖推出的新机型,东方红LX1504拖拉机是在借鉴国外先进技术基础上,根据市场需求自行开发的,具有国际先进水平的四轮驱动型轮式拖拉机。其... 一、东方红LX1504拖拉机作为国产"老大哥",东方红这一款LX1504拖拉机颇受消费者喜爱。作为中国一拖推出的新机型,东方红LX1504拖拉机是在借鉴国外先进技术基础上,根据市场需求自行开发的,具有国际先进水平的四轮驱动型轮式拖拉机。其动力强劲、性能卓越、造型美观、视野开阔、适应性强,广泛适用于各种农田作业和运输等其他作业。东方红LX1504拖拉机分为冬麦区(天骄)和东北型两款。 展开更多
关键词 拖拉机 中国一拖 农田作业 冬麦区 驱动 四轮 东北 天骄 农机企业 一款
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Spatial connectivity and distribution of landscape type in the natural secondary forests of eastern mountainous region,northeast China——a case study of Mao'ershan region in Heilongjiang Province
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作者 李淑娟 隋玉正 +2 位作者 冯海清 王凤友 李玉文 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第2期141-144,i003,共5页
Mao'ershan region is representative in the natural secondary forested region of the eastern mountainous region, northeast China. The landscape nearest neighbor index and landscape connectivity index were calculate... Mao'ershan region is representative in the natural secondary forested region of the eastern mountainous region, northeast China. The landscape nearest neighbor index and landscape connectivity index were calculated with ARC/INFO software for Mao'ershan region. The spatial distribution of the landscape of the region was analyzed. The results showed that the landscape connectivity index of non-woodland was significantly higher than that of woodland. The landscape connectivity index of natural forest was nearly equal to zero, which means its fragmentation degree is high. The nearest neighbor index of plantation was lower than that of natural forest and non-forestland. Among the man-made forests, the distance index of the coniferous mixed plantation is the lowest, and its pattern is nearly glomeration. The landscape pattern of natural forest presented nearly random distribution. Among non-forest land, the distance index of cut blank was the lowest, and its pattern was also nearly glomeration. Keywords Landscape type - Landscape pattern - Nearest neighbor index - Landscape connectivity index - Natural secondary forest - Northeast China CLC number S759.92 Document code A Foundation item: This paper was supported by the Key Project of State Department of Science Technology (2002BA515B040).Biography: LI SHu-juan (1977), female. Lecture in Ocean University of China, Qingdao 266003, P. R. China.Responsible editor: Zhu Hong 展开更多
关键词 Landscape type Landscape pattern Nearest neighbor index Landscape connectivity index Natural secondary forest Northeast China
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Using ^(137)Cs Tracer Technique to Evaluate Erosion and Deposition of Black Soil in Northeast China 被引量:33
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作者 FANG Hua-Jun YANG Xue-Ming +1 位作者 ZHANG Xiao-Ping LIANG Ai-Zhen 《Pedosphere》 SCIE CAS CSCD 2006年第2期201-209,共9页
Soil and water losses through erosion have been serious in the black soil region of Northeast China. Therefore, a sloping cultivated land in Songnen Plain was selected as a case study to: 1) determine the ^137Cs ref... Soil and water losses through erosion have been serious in the black soil region of Northeast China. Therefore, a sloping cultivated land in Songnen Plain was selected as a case study to: 1) determine the ^137Cs reference inventory in the study area; 2) calculate erosion and deposition rates of black soil on different slope locations; 3) conduct a sensitivity analysis of some model parameters; and 4) compare overall outputs using four different models. Three transects were set in the field with five slope locations for each transect, including summit, shoulder-slope, back-slope, foot-slope, and toe-slope. Field measurements and model simulation were used to estimate a bomb-derived ^137Cs reference inventory in the study area. Soil erosion and deposition rates were estimated using four ^137Cs models and percentage of ^137Cs loss/gain. The ^137Cs reference value in the study area was 2 232.8 Bq m^-2 with ^137Cs showing a clear topographic pattern, decreasing from the summit to shoulder-slope, then increasing again at the foot-slope and reaching a maximum at the toe-slope, Predicted soil redistribution rates for different slope locations varied. Among models, the Yang Model (YANG-M) overestimated erosion loss but underestimated deposition. However, the standard mass balance model (MBM1) gave predictions similar to a mass balance model incorporating soil movement by tillage (MBM2). Sensitivity analysis of the proportion factor and distribution pattern of ^137Cs in the surface layer demonstrated the impact of ^137Cs enrichment on calculation of the soil erosion rate. Factors influencing the redistribution of fallout ^137Cs in landscape should be fully considered as calculating soil redistribution rate using ^137Cs technique. 展开更多
关键词 black soil cesium-137 (^137Cs) Northeast China quantitative models soil erosion
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Effect of Magnetic Field on Enzyme Activities in Main Soils of Northeast China 被引量:6
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作者 LIUXIAOYI YIYANLI 《Pedosphere》 SCIE CAS CSCD 1996年第4期341-348,共8页
Soil enzyme activities as affected by applied magnetic field were studied with three main soils (brown soil, black soil and albic soil) collected from Northeast China. Appropriate intensities of magnetic field could o... Soil enzyme activities as affected by applied magnetic field were studied with three main soils (brown soil, black soil and albic soil) collected from Northeast China. Appropriate intensities of magnetic field could obviously enhance the activities of hydrogen peroxidases, invertases, amylases and phosphatases in the three soils, although the effect varied with types and water regimes of the soils. Increasing times of magnetic treatment could multiple its good effect on the activities of hydrogen peroxidases in soils. 展开更多
关键词 magnetic effect magnetic treatment soil enzyme activity
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Assessment of Point and Nonpoint Sources Pollution in Songhua River Basin,Northeast China by Using Revised Water Quality Model 被引量:14
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作者 YANG Yuhong YAN Baixing SHEN Wanbin 《Chinese Geographical Science》 SCIE CSCD 2010年第1期30-36,共7页
Individual participation of pollutants in the pollution load should be estimated even if roughly for the appropriate environmental management of a river basin.It is difficult to identify the sources and to quantify th... Individual participation of pollutants in the pollution load should be estimated even if roughly for the appropriate environmental management of a river basin.It is difficult to identify the sources and to quantify the load, especially in modeling nonpoint source.In this study a revised model was established by integrating point and nonpoint sources into one-dimensional Streeter-Phelps(S-P) model on the basis of real-time hydrologic data and surface water quality monitoring data in the Jilin Reach of the Songhua River Basin.Chemical oxygen demand(COD) and ammonia nitrogen(NH 3-N) loads were estimated.Results showed that COD loads of point source and nonpoint source were 134 958 t/yr and 86 209 t/yr, accounting for 61.02% and 38.98% of total loads, respectively.NH 3-N loads of point source and nonpoint source were 16 739 t/yr and 14 272 t/yr, accounting for 53.98% and 46.02%, respectively.Point source pollution was stronger than nonpoint source pollution in the study area at present.The water quality of upstream was better than that of downstream of the rivers and cities.It is indispensable to treat industrial wastewater and municipal sewage out of point sources, to adopt the best management practices to control diffuse pollutants from agricultural land and urban surface runoff in improving water quality of the Songhua River Basin.The revised S-P model can be successfully used to identify pollution source and quantify point source and nonpoint source loads by calibrating and validating. 展开更多
关键词 ammonia nitrogen chemical oxygen demand nonpoint source pollution point source pollution revised water quality model Songhua River Basin
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Decomposition Analysis on Direct Material Input and Dematerialization of Mining Cities in Northeast China 被引量:4
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作者 QIU Fangdao TONG Lianjun +1 位作者 ZHANG Huimin ZHANG Na 《Chinese Geographical Science》 SCIE CSCD 2009年第2期104-112,共9页
Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calcul... Material dematerialization is a basic approach to reduce the pressure on the resources and environment and to realize the sustainable development. The material flow analysis and decomposition method are used to calculate the direct material input (DMI) of 14 typical mining cities in Northeast China in 1995–2004 and to analyze the demateri- alization and its driving factors in the different types of mining cities oriented by coal, petroleum, metallurgy and multi-resources. The results are as follows: 1) from 1995 to 2006, the increase rates of the DMI and the material input intensity of mining cities declined following the order of multi-resources, metallurgy, coal, and petroleum cities, and the material utilizing efficiency did following the order of petroleum, coal, metallurgy, and multi-resources cities; 2) during the research period, all the kinds of mining cities were in the situation of weak sustainable development in most years; 3) the pressure on resources and environment in the multi-resources cities was the most serious; 4) the petro- leum cities showed the strong trend of sustainable development; and 5) in recent years, the driving function of eco- nomic development for material consuming has continuously strengthened and the controlling function of material utilizing efficiency for it has weakened. The key approaches to promote the development of circular economy of min- ing cities in Northeast China are put forward in the following aspects: 1) to strengthen the research and development of the technique of resources’ cycling utilization, 2) to improve the utilizing efficiency of resources, and 3) to carry out the auditing system of resources utilization. 展开更多
关键词 direct material input material flow analysis DEMATERIALIZATION decomposition method mining cities Northeast China
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Conceptualizing and Measuring Economic Resilience of Resource-based Cities: Case Study of Northeast China 被引量:29
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作者 TAN Juntao ZHANG Pingyu +2 位作者 LO Kevin LI Jing LIU Shiwei 《Chinese Geographical Science》 SCIE CSCD 2017年第3期471-481,共11页
This paper develops a conceptual model and an indicator system for measuring economic resilience of resource-based cities based on the theory of evolutionary resilience and the related concepts of persistence, adaptat... This paper develops a conceptual model and an indicator system for measuring economic resilience of resource-based cities based on the theory of evolutionary resilience and the related concepts of persistence, adaptation, and transformation. Nineteen resource-based cities in Northeast China were analyzed using the indicator system. The results showed that Liaoning and Jilin provinces had higher economic resilience than Heilongjiang Province. Panjin, Benxi, and Anshan in Liaoning Province were the top three cities, while Shuangyashan and other coal-based cities in Heilongjiang Province ranked last. Metals-and petroleum-based cities had significantly higher resilience than coal-based cities. The differences in persistence, adaptability, transformation, and resilience among resource-based cities decreased since the introduction of the Northeast Revitalization Strategy in 2003. Forestry-based cities improved the most in terms of resilience, followed by metals-based and multiple-resource cities; however, resilience dropped for coal-based cities, and petroleum-based cities falling the most. The findings illustrate the importance and the way to develop a differentiated approach to improve resilience among resource-based cities. 展开更多
关键词 resource-based cities economic resilience Northeast China
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A Seasonal Prediction Model for the Summer Rainfall in Northeast China Using the Year-To-Year Increment Approach 被引量:9
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作者 ZHU Ya-Li 《Atmospheric and Oceanic Science Letters》 2011年第3期146-150,共5页
Using the year-to-year increment approach,this study investigated the relationship of selected climatic elements with the increment time series of the summer rainfall between successive years in Northeast China,includ... Using the year-to-year increment approach,this study investigated the relationship of selected climatic elements with the increment time series of the summer rainfall between successive years in Northeast China,including the soil moisture content,sea surface temperature,500 hPa geopotential height,and sea level pressure in the preceding spring for the period 1981-2008.Two spring predictors were used to construct the seasonal prediction model:the area mean soil moisture content in Northwest Eurasia and the 500 hPa geopotential height over Northeast China.Both the cross-validation and comparison with previous studies showed that the above two predictors have good predicting ability for the summer rainfall in Northeast China. 展开更多
关键词 Northeast China summer rainfall seasonalprediction year-to-year increment
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Effects of Forest Type and Urbanization on Carbon Storage of Urban Forests in Changchun, Northeast China 被引量:9
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作者 ZHANG Dan ZHENG Haifeng +5 位作者 REN Zhibin ZHAI Chang SHEN Guoqiang MAO Zhixia WANG Peijiang HE Xingyuan 《Chinese Geographical Science》 SCIE CSCD 2015年第2期147-158,共12页
Rapid urbanization has led to dramatic changes in urban forest structures and functions, and consequently affects carbon(C) storage in cities. In this study, field surveys were combined with high resolution images to ... Rapid urbanization has led to dramatic changes in urban forest structures and functions, and consequently affects carbon(C) storage in cities. In this study, field surveys were combined with high resolution images to investigate the variability of C storage of urban forests in Changchun, Northeast China. The main objectives of this study were to quantify the C storage of urban forests in Changchun City, Northeast China and understand the effects of forest type and urbanization on C storage of urban forests. The results showed that the mean C density and the total C storage of urban forests in Changchun were 4.41 kg/m2 and 4.74 × 108 kg, respectively. There were significant differences in C density among urban forest types. Landscape and relaxation forest(LF) had the highest C density with 5.41 kg/m2, while production and management forest(PF) had the lowest C density with 1.46 kg/m2. These differences demonstrate that urban forest type is an important factor needed to be considered when the C storage is accurately estimated. Further findings revealed significant differences in different gradients of urbanization, and the mean C density decreased from the first ring(6.99 kg/m2) to the fourth ring(2.87 kg/m2). The total C storage increased from the first ring to the third ring. These results indicate that C storage by urban forests will be significantly changed during the process of urbanization. The results can provide insights for decision-makers and urban planners to better understand the effects of forest type and urbanization on C storage of urban forests in Changchun, and make better management plans for urban forests. 展开更多
关键词 urban forest carbon storage carbon density urbanization gradients climate change
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Land Use Effects on Soil Organic Carbon, Microbial Biomass and Microbial Activity in Changbai Mountains of Northeast China 被引量:16
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作者 FANG Xiangmin WANG Qingli +4 位作者 ZHOU Wangming ZHAO Wei WEI Yawei NIU Lijun DAI Limin 《Chinese Geographical Science》 SCIE CSCD 2014年第3期297-306,共10页
Land use changes are known to alter soil organic carbon (SOC) and microbial properties, however, information about how conversion of natural forest to agricultural land use as well as plantations affects SOC and mic... Land use changes are known to alter soil organic carbon (SOC) and microbial properties, however, information about how conversion of natural forest to agricultural land use as well as plantations affects SOC and microbial properties in the Changbai Moun- tains of Northeast China is meager. Soil carbon content, microbial biomass carbon (MBC), basal respiration and soil carbon mineraliza- tion were studied in five selected types of land use: natural old-growth broad-leaved Korean pine mixed forest (NF); spruce plantation (SP) established following clear-cutting of NF; cropland (CL); ginseng farmland (GF) previously under NF; and a five-year Mongolian oak young forest (YF) reforested on an abandoned GF, in the Changbai Mountains of Northeast China in 2011. Results showed that SOC content was significantly lower in SP, CL, GF, and YF than in NF. MBC ranged from 304.4 mg/kg in CL to 1350.3 mg/kg in NF, which was significantly higher in the soil of NF than any soil of the other four land use types. The SOC and MBC contents were higher in SP soil than in CL, GF, and YF soils, yielding a significant difference between SP and CL. The value of basal respiration was also higher in NF than in SP, CL, GF, and YF. Simultaneously, higher values of the metabolic quotient were detected in CL, GF, and YF soils, indicat- ing low substrate utilization of the soil microbial community compared with that in NF and SP soil. The values of cumulative mineral- ized carbon and potentially mineralized carbon (Co) in NF were significantly higher than those in CL and GF, while no significant dif- ference was observed between NF and SP. In addition, YF had higher values of Co and C mineralization rate compared with GF. The results indicate that conversion from NF into agricultural land (CL and GF) uses and plantation may lead to a reduction in soil nutrients (SOC and MBC) and substrate utilization efficiency of the microbial community. By contrast, soils below SP were more conducive to the preservation of soil organic matter, which was reflected in the comparison of microbial indicators among CL, GF, and YF land uses. This study can provide data for evaluating soils nutrients under different land use types, and serve as references for the rational land use of natural forest in the study area. 展开更多
关键词 land use soil organic carbon (SOC) microbial biomass carbon (MBC) carbon mineralization basal respiration ChangbaiMountains
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Analysis of the effect of medical insurance on cancer inpatients: A 10-year retrospective study on a large hospital in Northeast China 被引量:1
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作者 Zhendong Zheng Lu Wang +2 位作者 Quanwei Fu Tao Han Xiaodong Xie 《Oncology and Translational Medicine》 2015年第6期284-288,共5页
Objective The aim of the study was to analyze hospital costs for cancer inpatients availing different methods of payment and the influencing factors, to provide inputs to improve the medical insurance payment policy. ... Objective The aim of the study was to analyze hospital costs for cancer inpatients availing different methods of payment and the influencing factors, to provide inputs to improve the medical insurance payment policy. Methods We analyzed the information related to length of hospital stay, hospitalization cost, and self-pay cost, collected from one large-scale, Grade A, Class Three hospital in Shenyang, China, during 2004–2013.Results The number of cancer inpatients with different payment types(medical insurance group and non-medical insurance group) presented a rising trend. Further, the ratio of medical insurance inpatients increased rapidly(from 22.2% to 48.7%); however, this group was still a minority. The length of hospital stay became shorter(21 d vs. 17 d; P = 0.000) while the gap got narrower; the hospitalized expense showed an upward trend and the difference was remarkable($24048.6 ± $4376.28 vs. $20544.36 ± $4057.01; P = 0.000). Conclusion Along with normalization of cancer therapy, the influence of payment on treatment has been getting weak, the policy has impact on controlling hospitalization cost, lightening burden of cancer patient, as well as allocating medical resources in a reasonable way, becoming an important defray pattern of hospitalization cost. 展开更多
关键词 medical insurance cancer inpatients retrospective study
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Iron-Oxide Cu-Au Mineralizing Systems: Eastern Yakutia Perspective
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作者 Aleksey Kostin 《Journal of Environmental Science and Engineering(B)》 2012年第9期1045-1053,共9页
The GIS (geographic information system) used for predicting the associated with upper-intrusive zone of hydrothermal alteration IOCG (iron-oxide copper gold) mineralizing systems is shown by example of the northea... The GIS (geographic information system) used for predicting the associated with upper-intrusive zone of hydrothermal alteration IOCG (iron-oxide copper gold) mineralizing systems is shown by example of the northeast of Russian. IOCG ore deposits can have enormous geological resources with significant reserves of base, precious and strategic metals, are economically attractive targets for mineral exploration worldwide, but are still unknown in the northeast Russian. It was localized in Tarinskiy ore node (eastern Yakutia) field of brecciated altered rocks with sulfide and iron-oxide cement is a first in eastern Yakutia nature anomaly of IOCG-type with iron-oxide Cu-Au ± U specialization, that was formed close to the surface of Rep-Yuruinskiy pluton. It should be of interest as a new precious metals world class deposit type in northeast of Russia. 展开更多
关键词 GIS iron oxide-Cu-Au ± U Rep-Yuruinskiy Tarinskiy ore node.
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Simulation of Precipitation in Monsoon Regions of China by CMIP3 Models 被引量:3
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作者 TU Kai YAN Zhong-Wei +1 位作者 ZHANG Xue-Bin DONG Wen-Jie 《Atmospheric and Oceanic Science Letters》 2009年第4期194-200,共7页
The output of 25 models used in the Coupled Model Intercomparison Project phase 3 (CMIP3) were evaluated,with a focus on summer precipitation in eastern China for the last 40 years of the 20th century.Most mod-els fai... The output of 25 models used in the Coupled Model Intercomparison Project phase 3 (CMIP3) were evaluated,with a focus on summer precipitation in eastern China for the last 40 years of the 20th century.Most mod-els failed to reproduce rainfall associated with the East Asian summer monsoon (EASM),and hence the seasonal cycle in eastern China,but provided reasonable results in Southwest (SW) and Northeast China (NE).The simula-tions produced reasonable results for the Yangtze-Huai (YH) Basin area,although the Meiyu phenomenon was underestimated in general.One typical regional phe-nomenon,a seasonal northward shift in the rain belt from early to late summer,was completely missed by most models.The long-term climate trends in rainfall over eastern China were largely underestimated,and the ob-served geographical pattern of rainfall changes was not reproduced by most models.Precipitation extremes were evaluated via parameters of fitted GEV (Generalized Ex-treme Values) distributions.The annual extremes were grossly underestimated in the monsoon-dominated YH and SW regions,but reasonable values were calculated for the North China (NC) and NE regions.These results suggest a general failure to capture the dynamics of the EASM in current coupled climate models.Nonetheless,models with higher resolution tend to reproduce larger decadal trends and annual extremes of precipitation in the regions studied. 展开更多
关键词 PRECIPITATION East Asian Monsoon IPCC AR4 coupled models generalized extreme values
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Effects of Spatial Aggregation on Forest Landscape Model Simulation in Northeastern China
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作者 周宇飞 贺红士 +2 位作者 布仁仓 金龙如 李秀珍 《Transactions of Tianjin University》 EI CAS 2009年第3期178-186,共9页
Issues of scale and aggregation become important when large range of space and time scales is considered in landscape models.However,identifying appropriate levels of aggregation to accurately represent the processes ... Issues of scale and aggregation become important when large range of space and time scales is considered in landscape models.However,identifying appropriate levels of aggregation to accurately represent the processes and components of ecological systems is challenging.A raster-based spatially explicit forest landscape model,LANDIS,was used to study the effects of spatial aggregation on simulated spatial pattern and ecological process in Youhao Forest Bureau of the Small Khingan Mountain in Northeastern China.The model was tested over 500 simulation years with systematically increased levels of spatial aggregation.The results show that spatial aggregation significantly influences the simulation of fire disturbance,species abundance,and spatial pattern.Simulated fire regime was relatively insensitive to grain size between 30.m and 270.m in the region.Spatial aggregation from 300.m to 480.m dramatically decreased fire return interval(FRI) and increased mean fire size.Generally,species abundance and its aggregation index(AI) remained higher level over simulation years at the fine-grained level of spatial aggregation than at coarser grains.In addition,the simulated forest dynamics was more realistic at finer grains.These results suggest that appropriate levels of spatial aggregation for the model should not be larger than 270m. 展开更多
关键词 SCALE spatial aggregation LANDIS fire disturbance SUCCESSION spatial pattern Northeastern China
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Study on the Non-point Source Pollution in the Upper and Middle Reaches of the Taoer River Basin 被引量:2
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作者 Liu Yumei Li Lijuan +1 位作者 Liang Liqiao Li Jiuyi 《Chinese Journal of Population,Resources and Environment》 2011年第1期48-54,共7页
The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source ... The Taoer River basin is the epitome in the west of Northeast China and it is one of the most fragile and sensitive ecoregions. Thus, protection of water quality of the Taoer River is important. Not only point source pollution but non-point source (NPS) pollution results in deteriorating water quality. In this study, long-term hydrologic impact assessment model was used to evaluate the impacts of land use change impacts on NPS pollution, and the replacement cost method was used to calculate the economic loss caused by NPS pollution. Through analyzing the NPS pollutant loads of different land categories and the economic loss, the article puts forward that there exists a close relationship between land-use types and NPS pollution, and agricultural pollution is the main component of the NPS pollution in this area. The results of this study can provide decision-making basis for agricultural development and land-use change. 展开更多
关键词 NPS L-THIA economic loss Taoer River Basin
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