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Numerical modeling of deep-seated landslides interacting with man-made structures 被引量:3
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作者 Giovanni Barla 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2018年第6期1020-1036,共17页
This paper describes the interaction between deep-seated landslides and man-made structures such as dams, penstocks, viaducts, and tunnels. Selected case studies are reported first with the intent to gain insights int... This paper describes the interaction between deep-seated landslides and man-made structures such as dams, penstocks, viaducts, and tunnels. Selected case studies are reported first with the intent to gain insights into the complexities associated with the interaction of these structures with deep-seated landslides(generally referred to as deep-seated gravity slope deformations, DSGSDs). The main features, which characterize these landslides, are mentioned together with the interaction problems encountered in each case. Given the main objective of this paper, the numerical modeling methods adopted are outlined as means for increase in the understanding of the interaction problems being investigated. With the above in mind, the attention moves to an important and unique case history dealing with the interaction of a large-size twin-tunnel excavated with an earth pressure balance(EPB)tunnel boring machine(TBM) and a deep-seated landslide, which was reactivated due to the stress changes induced by tunnel excavation in landslide shear zone. The geological and geotechnical conditions are described together with the available monitoring data on the landslide movements, based on the advanced and conventional monitoring tools used. Numerical modeling is illustrated as an aid to back-analyze the monitored surface and subsurface deformations and to assist in finding the appropriate engineering solution for putting the tunnel into service and as a follow-up means for future understanding and control of the interaction problems. The simulation is based on a novel time-dependent model representing the landslide behavior. 展开更多
关键词 Deep-seated landslides man-made structures Landslide-structure interaction Monitoring of landslide movement Numerical modeling
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Considering and comparing regeneration in natural and man-made stands in northern Iran
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作者 Mir Mozaffar FALLAHCHAI 《Forestry Studies in China》 CAS 2012年第2期131-136,共6页
In this study the regeneration diversity of Syahkal forests afforestated and natural stands in north of Iran was studied and compared from the point of view of evenness and diversity index. In order to accomplish this... In this study the regeneration diversity of Syahkal forests afforestated and natural stands in north of Iran was studied and compared from the point of view of evenness and diversity index. In order to accomplish this study two natural and man-made stands that almost are located in the same height above the sea level were chosen. The area of each stand was 30 ha and the inventory was done by the random-systematic method with a 5R land measurement (500 m2) selected. Also, in order to study the regeneration in the center of each sample piece 125 square meters micro plots were formed. The results show that regeneration diversity index in natural stands is more than that in man-made stands which in this case Mc-Arthur index with 2.41 has the most amount while Simpson index with 0.543 has the least amount. But the evenness indexes in man-made stands are more than that in natural stand which the main reason is the purity of the man-made stand. 展开更多
关键词 diversity EVENNESS man-made stands Iran's forests
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Ecology and Fish Biodiversity of Man-Made Lakes of Southern Benin (West Africa): Implications for Species Conservation and Fisheries Management
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作者 Houehanou M. A. G. Gbaguidi Alphonse Adite Edmond Sossoukpe 《Journal of Environmental Protection》 2016年第6期874-894,共21页
Man-made lakes are alternative and potential habitats for biodiversity conservation, fisheries and extensive aquaculture. We investigated the ecology and the fish community structure of two (2) sand-dragged man-made l... Man-made lakes are alternative and potential habitats for biodiversity conservation, fisheries and extensive aquaculture. We investigated the ecology and the fish community structure of two (2) sand-dragged man-made lakes, Lake Ahozon and Lake Bewacodji of Southern Benin, with implications for species conservation, fisheries management and aquaculture valorization. From August 2014 to July 2015, habitats conditions were evaluated and fishes were sampled monthly with seine, cast net, experimental gill net and hooks in the open water and aquatic vegetation habitats of both lakes. Overall, the water quality of Lake Ahozon was globally favorable for the growth and the survival of the fish resources whereas Lake Bewacodji exhibited a poor water quality indicated mainly by an acid pH (mean: 6.32 ± 0.58) and low dissolved oxygen concentrations (mean: 3.52 ± 1.25 mg/l) caused by dense floating plants, Nymphea sp mainly and huge daily dumping of domestic wastes. The study revealed low species richness, d = 5.89 and d = 3.87, and low species diversity, H’ = 0.76 and H’ = 0.48 for Lakes Ahozon and Bewacodji, respectively, with Lake Ahozon more diverse than Lake Bewacodji. The fish community of Lake Ahozon comprised six (6) species, 3 cichlids Sarotherodon galilaeus, Oreochromis niloticus and Tilapia guineensis, the silver catfish, Chrysichthys nigrodigitatus (Claroteidae), the African bonytongue, Heterotis niloticus (Osteoglossidae), and the African catfish, Clarias gariepinus (Clariidae). Numerically, S. galilaeus dominated Lake Ahozon and made 85.21% of the sample. In Lake Bewacodji, the fish composition comprised four (4) species, Sarotherodon galilaeus multifasciatus, the dominant species making numerically 91.58% of the total sample, T. guineensis, C. gariepinus and C. nigrodigitatus. With regard to trophic structure, the fish assemblages of both lakes were numerically dominated by planktinovores/ detritivores, mainly S. galilaeus, O. niloticus, T. guineensis and C. nigrodigitatus making together 99.46% of Lake Ahozon fish community, and S. galilaeus multifasciatus, T. guineensis and C. nigrodigitatus accounting together for about 98.59% of Lake Bewacodji. In Lake Ahozon, standard length (SL) frequencies histograms showed an unimodal size distribution for H. niloticus, the nile tilapia O. niloticus and C. gariepinus whereas the two cichlids, S. galilaeus and T. guineensis exhibited a bimodal size distribution. In Lake Bewacodji, S. galilaeus multifasciatus, C. nigrodigitatus and C. gariepinus exhibited an unimodal size distribution. A sustainable exploitation of both man-made lakes requires the implementation of an integrated management scheme which should include habitat restoration and protection plan, fisheries/aquacultural valorization, ecological sound agriculture/ecotourism and environmental monitoring.   展开更多
关键词 Conservation Diversity Domestic Wastes FISHERIES Habitat Degradation MANAGEMENT man-made Lakes Sand-Dragging Sarotherodon galilaeus
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The 25th CIMFC(Bengbu 2019):Exploring the future of the man-made fibers
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《China Textile》 2019年第10期38-43,共6页
The 25th China International Man-made Fiber Conference (Bengbu 2019)(hereinafter referred to as CIMFC 2019), themed on “Opening and Integaration for Interactive Development — Coordinated Progress of Global Man-Made ... The 25th China International Man-made Fiber Conference (Bengbu 2019)(hereinafter referred to as CIMFC 2019), themed on “Opening and Integaration for Interactive Development — Coordinated Progress of Global Man-Made Fiber Industry”, was convened in Bengbu City, Anhui Province. CIMFC 2019 was sponcored by China National Textile and Apparel Council (CNTAC), organized by China Chemical Fibers Association, Chi-na Textile International Exchange Center, and China BBCA Group Corp., supported by Bengbu Municipal People’s Goverment, and co-organized by Bengbu Investment Promotion and Foreign cooperation Center, Bengbu Municipal Bureau of Commerce and Foreign Affairs, and Oerlikon Man-made Fiber. 展开更多
关键词 CIMFC Bengbu man-made fibers
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MAN-MADE
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作者 崔东豪(台湾)(绘画) 《世界儿童(漫画版)》 2010年第2期8-11,共4页
前情提要 似水与流年根据博士日记上面的提示一路找到太阳遗迹,终于见到了博士,博士向两人说明了一切,原来,流年竟是人造人……
关键词 初等教育 漫画 课外阅读 man-made
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MAN-MADE
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《世界儿童(漫画版)》 2010年第9期8-11,共4页
名月背叛了虎帝大人,他要所有的新型M-M战士听命于他。于是,被博士利用变身药丸救出的流年他们决定要阻止名月。
关键词 初等教育 漫画 课外阅读 man-made
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THE CAS AND CHINA'S FIRST MAN-MADE EARTH SATELLITE Lu Shouguan(Chinese Academy of Sciences)
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作者 Lu Shouguan Chinese Academy of Sciences Director of the former Task Office for Satellite Develop-ment under the CAS and former director of the CAS Bureau of Planning 《Bulletin of the Chinese Academy of Sciences》 2000年第1期52-62,共11页
In the festivedays whencelebrating the50th anniversa-ry of the found-ing of the Peo-ple’s Republic,and the 50th an-niversary of thefounding of theChinese Acad-emy of Scienc-es (CAS), it isnatural for thepeople to thi... In the festivedays whencelebrating the50th anniversa-ry of the found-ing of the Peo-ple’s Republic,and the 50th an-niversary of thefounding of theChinese Acad-emy of Scienc-es (CAS), it isnatural for thepeople to thinkwith pride ofChina’s 展开更多
关键词 Chinese Academy of Sciences THE CAS AND CHINA’S FIRST man-made EARTH SATELLITE Lu Shouguan CAS
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Man-made fiber industry enjoys optimistic transformation and upgrading
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《China Textile》 2017年第12期18-19,共2页
As an important fundamental industry of the national economy,the man-made fiber industrial chain is integrated into the era development and it assumes the responsibility of advancing.Each link of the industrial chain ... As an important fundamental industry of the national economy,the man-made fiber industrial chain is integrated into the era development and it assumes the responsibility of advancing.Each link of the industrial chain is connected with each other.After the development and accumulation of several decades,the new produced polyester,PTA and other plants keep 展开更多
关键词 man-made fiber industry enjoys optimistic transformation and upgrading PTA
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Notable effects on comprehensive techniques of man-made biosphere in rice fields
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作者 Feng Yilen,CNRRI 《Chinese Rice Research Newsletter》 1996年第4期12-12,共1页
Studied by Mr. LIU Zhongzhu, ex Chairman of Fujian Academy of Agri Sciences, a combined technique of man—made biosphere in rice fields deserves notice. The research indicated that using man—made biosphere in rice fi... Studied by Mr. LIU Zhongzhu, ex Chairman of Fujian Academy of Agri Sciences, a combined technique of man—made biosphere in rice fields deserves notice. The research indicated that using man—made biosphere in rice fields can enrich soil, reduce the infects of diseases, insects and weeds, economize the use of pesticide and herbicide, decrease green house effect, and improve atmosphere. As tested, the yield for rice is usually 10500—12000 kg/ha, for fish is usually 2250—3250 kg/ha. Again, about 50%—60% fertilizer and 30%—50% pesticide can be saved. The net income increased $ 1,080—1,800 per ha. 展开更多
关键词 Notable effects on comprehensive techniques of man-made biosphere in rice fields
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Effects of sand burial on biomass, chlorophyll fluores-cence and extracellular polysaccharides of man-made cyanobacterial crusts under experimental conditions 被引量:9
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作者 WANG WeiBo1,2, YANG CuiYun1,2, TANG DongShan1,2, LI DunHai1, LIU YongDing1& HU ChunXiang1 1 State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100039, China 《Science China(Life Sciences)》 SCIE CAS 2007年第4期530-534,共5页
Soil cyanobacterial crusts occur throughout the world, especially in the semiarid and arid regions. It always encounters sand burial, which is an important feature of mobile sand dunes. A greenhouse study was conducte... Soil cyanobacterial crusts occur throughout the world, especially in the semiarid and arid regions. It always encounters sand burial, which is an important feature of mobile sand dunes. A greenhouse study was conducted to determine the effects of sand burial on biomass, chlorophyll fluorescence and extracellular polysaccharides of man-made cyanobacterial crusts in six periods of time (0, 5, 10, 15, 20 and 30 d after burying) and at five depths (0, 0.2, 0.5, 1 and 2cm). The results indicated that with the increase of the burial time and burial depth extracellular polysaccharides content and Fv/Fm decreased correspondingly and there were no significant differences between 20 and 30 burial days under dif-ferent burial depths. The degradation of chlorophyll a content appeared only at 20 and 30 burial days and there was also no significant difference between them under different burial depths. It was also observed a simultaneous decrease of the values of the Fv/Fm and the content of extracellular poly-saccharides happened in the crusted cyanobacterium Microcoleus vaginatus Gom. It may suggest that there exists a relationship between extracellular polysaccharides and recovery of the activity of pho-tosystem II (PS II) after rehydration. 展开更多
关键词 Microcoleus vaginatus Gom. man-made CYANOBACTERIAL CRUSTS sand burial BIOMASS photosynthetic activity extracellular polysaccharides
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A man-made object detection algorithm based on contour complexity evaluation 被引量:2
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作者 Guili XU Zhengbing WANG +2 位作者 Yuehua CHENG Yupeng TIAN Chao ZHANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第6期1931-1957,共27页
Man-made object detection is of great significance in both military and civil areas, such as search-and-rescue missions at sea, traffic signs recognition during visual navigation, and targets location in a military st... Man-made object detection is of great significance in both military and civil areas, such as search-and-rescue missions at sea, traffic signs recognition during visual navigation, and targets location in a military strike. Contours of man-made objects usually consist of straight lines, corner points, and simple curves. Motivated by this observation, a man-made object detection method is proposed based on complexity evaluation of object contours. After salient contours which keep the crucial information of objects are accurately extracted using an improved mean-shift clustering algorithm, a novel approach is presented to evaluate the complexity of contours. By comparing the entropy values of contours before/after sampling and linear interpolation, it is easy to distinguish between man-made objects and natural ones according to the complexity of their contours.Experimental results show that the presented method can effectively detect man-made objects when compared to the existing ones. 展开更多
关键词 Complexity evaluation Contour chain code Contour detection man-made object detection Salient contour
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Mathematical modeling of microwave drying of crashed cotton stalks for man-made composite material
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作者 Wang Hongti Li Peng Guo Kangquan 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2016年第2期171-178,共8页
Drying characteristics,energy consumption and drying kinetics modeling of crashed cotton stalks dried in a microwave dryer were investigated in this research.A microwave dryer with an output power of 1000 W and 2450 M... Drying characteristics,energy consumption and drying kinetics modeling of crashed cotton stalks dried in a microwave dryer were investigated in this research.A microwave dryer with an output power of 1000 W and 2450 MHz was employed,and the effects of material load ranging from 50 g to 250 g on drying time,drying rate,drying efficiency and specific energy consumption were evaluated.The results showed that drying rate decreased with drying duration.A rising rate period was followed by a falling rate period and the overall drying process occurred in the falling rate period.Six mathematical models were used to fit the drying rates data of crashed cotton stalks,and Midilli et al.model was found the best prediction model by comparing R2,RMSE andχ^(2)values between experimental and predicted moisture ratios.With decrease in material load from 250 g to 50 g,effective moisture diffusivity increased from 2.8668×10^(-8)m^(2)/s to 7.9817×10^(-8)m^(2)/s.Results also indicated that drying efficiency and specific energy consumption significantly increased with the increase of the material load.Average drying efficiency and specific energy consumption varied in the range of 7.52%-19.78%and 12.49-35.90 MJ/kg water,respectively.There were a lowest energy consumption of 10.99 MJ/kg water and a highest drying efficiency of 17.13%at the material load level of 250 g. 展开更多
关键词 mathematical modeling crashed cotton stalks man-made composite material microwave drying KINETICS
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Skiers Take to Man-made Slopes
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作者 Helen Pearson 夏廷芳 《科技英语学习》 2007年第3期10-11,共2页
人造雪技术在许多滑雪场地已经得到广泛应用:它制造足够的雪量使比赛顺利进行,也能制造出维持较久且状况较好的冰雪表面,使竞赛选手更容易创造新纪录。这项技术能缓解因全球气温变暖使得滑雪场地愈加难找这一难题。可是过度依赖人造雪... 人造雪技术在许多滑雪场地已经得到广泛应用:它制造足够的雪量使比赛顺利进行,也能制造出维持较久且状况较好的冰雪表面,使竞赛选手更容易创造新纪录。这项技术能缓解因全球气温变暖使得滑雪场地愈加难找这一难题。可是过度依赖人造雪也产生一些问题。国际保护阿尔卑斯山组织的人士表示,制造人造雪要消耗水及能量,而这些人造雪溶水则会对周围的生态系统造成影响。 展开更多
关键词 MAN 人造雪 Skiers Take to man-made Slopes
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Impacts of artificial dams on terrestrial water storage changes and the Earth's elastic load response during 1950-2016: A case study of medium and large reservoirs in Chinese mainland
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作者 Linsong Wang Mingtao Zhu +2 位作者 Yulong Zhong Jianwei Sun Zhenran Peng 《Geodesy and Geodynamics》 EI CSCD 2024年第3期252-263,共12页
The construction of dams for intercepting and storing water has altered surface water distributions, landsea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir prop... The construction of dams for intercepting and storing water has altered surface water distributions, landsea water exchanges, and the load response of the solid Earth. The lack of accurate estimation of reservoir properties through the land surface and hydrological models can lead to water storage simulation and extraction errors. This impact is particularly evident in many artificial reservoirs in China. The study aims to comprehensively assess the spatiotemporal distribution and trends of water storage in medium and large reservoirs(MLRs) in Chinese mainland during 1950-2016, and to investigate the gravity,displacement, and strain effects induced by the reservoir mass concentration using the load elasticity theory. In addition, the impoundment contributions of MLRs to the relative sea level changes were assessed using a sea-level equation. The results show impoundment increases in the MLRs during1950-2016, particularly in the Yangtze River(Changjiang) and southern basins, causing significant elastic load effects in the surrounding areas of the reservoirs and increasing the relative sea level in China's offshore. However, long-term groundwater estimation trends are overestimated and underestimated in the Yangtze River and southwestern basins, respectively, due to the neglect of the MLRs impacts or the uncertainty of the hydrological model's output(e.g., soil moisture, etc.). The construction of MLRs may reduce the water mass input from land to the ocean, thus slowing global sea level rise. The results of the impact of human activities on the regional water cycle provide important references and data support for improving the integration of hydrological models, evaluating Earth's viscoelastic responses under longterm reservoir storage, enhancing in-situ and satellite geodetic measurements, and identifying the main factors driving sea level changes. 展开更多
关键词 man-made dams Terrestrial water storage Elastic load response Sea level changes Chinese mainland
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新疆生产建设兵团水土保持遥感监管实施成效及相关建议
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作者 左强 李素雅 +2 位作者 房成泰 李宁 李骁 《水利发展研究》 2024年第5期53-58,共6页
新疆生产建设兵团自2019年以来创新水土保持监管模式,通过连年7次开展生产建设项目水土保持遥感监管,总体实现从问题导向被动监管转为目标靶向主动监管。文章系统总结了兵团生产建设项目水土保持遥感监管实施情况和工作成效,分析兵团水... 新疆生产建设兵团自2019年以来创新水土保持监管模式,通过连年7次开展生产建设项目水土保持遥感监管,总体实现从问题导向被动监管转为目标靶向主动监管。文章系统总结了兵团生产建设项目水土保持遥感监管实施情况和工作成效,分析兵团水土保持监管目前存在的问题,从重点关注项目建设期过程监管,推动水土保持执法能力建设,提高监管智能化水平,加强生产建设项目“全链条”监管等方面提出建议,以期为兵团及其他地区水土保持遥感监管提供有益参考。 展开更多
关键词 人为水土流失 水土保持 遥感 监管
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联系数-图论耦合的城市河网水系连通性评价 被引量:4
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作者 门宝辉 刘菁苹 《水力发电学报》 CSCD 北大核心 2023年第1期65-76,共12页
为分析城市化背景下洛阳市河网水系的连通性,根据其主要河流和人工河渠构建了河网图模型,应用五元联系数对河道连通性进行评价,利用集对分析与图论法耦合模型计算连通度,计算得到洛阳河网水系的连通度为1.34。在图模型中分别去掉6条人... 为分析城市化背景下洛阳市河网水系的连通性,根据其主要河流和人工河渠构建了河网图模型,应用五元联系数对河道连通性进行评价,利用集对分析与图论法耦合模型计算连通度,计算得到洛阳河网水系的连通度为1.34。在图模型中分别去掉6条人工河渠连通通道,构建新的图模型作为6个连通方案。6个方案连通度值分别为1.06、1.25、1.23、1.29、1.19、1.27。结果表明6条人工河渠对洛阳市河网水系格局连通性影响程度大小为:引黄入洛>伊洛连通>引黄济瀍>引畛济涧>中州渠>引洛济伊。该耦合模型实现了功能连通性与结构连通性的综合评价,并利用五元减法集对势分析影响连通性的因素,提出从水量、水库调度能力、河岸生态、水质等改善水系连通性。 展开更多
关键词 河网水系 连通性 图论 集对分析 人工河渠
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玉米秸秆前处理装置除叶整理机的设计
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作者 张佳彬 张艳红 +1 位作者 王赫昱 徐林 《林业机械与木工设备》 2023年第10期71-74,共4页
我国是一个农业大国,每年有大量的农作物秸秆面临着处理问题,然而传统的焚烧方式会对环境产生污染。将农作物秸秆原料化利用,生产高附加值的秸秆人造板,不仅创造了经济价值,更是推进节能减排固碳的关键举措,是助力我国实现碳达峰、碳中... 我国是一个农业大国,每年有大量的农作物秸秆面临着处理问题,然而传统的焚烧方式会对环境产生污染。将农作物秸秆原料化利用,生产高附加值的秸秆人造板,不仅创造了经济价值,更是推进节能减排固碳的关键举措,是助力我国实现碳达峰、碳中和的潜力所在。但由于秸秆叶片、叶鞘含量高,表面能低,秸秆基人造板在加工利用过程中还存在一些阻碍。介绍了一种秸秆前处理装置—除叶整理机设计及工作原理,可高效脱除玉米秸秆表面叶片、叶鞘,为玉米秸秆原料化利用提供可借鉴的路线。 展开更多
关键词 玉米秸秆 人造板 前处理 除叶整理机
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气候变化导致青藏高原马鹿种群适应性分布退缩:以类乌齐马鹿国家级自然保护区为例
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作者 叶秀林 郭克疾 +4 位作者 李欣蕊 吴庆 张梦斐 李明 赵序茅 《兽类学报》 CAS CSCD 北大核心 2023年第2期149-156,共8页
近50年青藏高原的气候变化速率是全球平均值的2倍,对高原有蹄类的种群分布和多样性维持带来严重影响。本研究以西藏类乌齐马鹿国家级自然保护区的马鹿种群为例,通过2013年和2021年对马鹿和牦牛种群数量、分布的调查,并整合了物种分布模... 近50年青藏高原的气候变化速率是全球平均值的2倍,对高原有蹄类的种群分布和多样性维持带来严重影响。本研究以西藏类乌齐马鹿国家级自然保护区的马鹿种群为例,通过2013年和2021年对马鹿和牦牛种群数量、分布的调查,并整合了物种分布模型和种群动态模型,评估了当前和未来气候变化及人类活动(放牧、道路、居民点等)对马鹿种群适应性分布的影响。研究表明,马鹿种群在2013—2021年由890头增加到1400头,根据种群增长模型预计在2050年马鹿种群数量将达到1735头,但其适宜栖息地在2050年代下降43.4%,2070年代下降5.1%,表明马鹿种群增长与适宜栖息地缩小之间的冲突将不利于马鹿种群的可持续发展。同时,当前马鹿与牦牛栖息地重合率为19%,2050年代为60%,2070年代为37%,且牦牛与马鹿存在食物竞争,这在一定程度上减少了马鹿原有的适宜栖息地。为保护马鹿,建议减少牦牛的饲养量1000~1500头。本研究将种群增长模型、种间竞争关系与物种分布模型整合,把气候变化对物种的影响延伸到种群层面,对其他物种的保护具有借鉴意义。 展开更多
关键词 物种保护 高原有蹄类 人为干扰 分布变迁 栖息地
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一种顾及多因子的生态保护红线勘界定标自动化预标注方法
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作者 高林营 武萌华 周智勇 《测绘通报》 CSCD 北大核心 2023年第3期160-164,共5页
生态保护红线勘界定标是确保生态保护红线精准落地的重要举措,是践行“绿水青山就是金山银山”理念的重要手段。本文提出了一种顾及多因子的生态保护红线勘界定标自动化预标注方法,即通过建立生态保护红线边界处的最小计算单元并定义其... 生态保护红线勘界定标是确保生态保护红线精准落地的重要举措,是践行“绿水青山就是金山银山”理念的重要手段。本文提出了一种顾及多因子的生态保护红线勘界定标自动化预标注方法,即通过建立生态保护红线边界处的最小计算单元并定义其片区属性,评估计算其地形地貌特征、道路通达性、人为活动的频繁程度,实现自动化获取大场景、大范围生态保护红线界桩、标识牌点位预标注区域;并以重庆市生态保护红线为试验区域,验证了该方法能够取得良好效果,提高了界桩、标识牌点位及布设密度的科学性、合理性,降低了生产成本,自动化程度高。 展开更多
关键词 多因子 勘界定标 地形地貌 道路通达性 人为活动
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华北低丘陵山区人工林土壤微生物生物量碳氮变化及其影响因素
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作者 庄静静 鲜靖苹 +2 位作者 王晓冰 李振华 程翠 《福建农业学报》 CAS CSCD 北大核心 2023年第12期1459-1465,共7页
【目的】土壤微生物是土壤中重要的存在,土壤中的微生物量碳和微生物量氮能直接或间接参与土壤理化过程,是维持土壤质量的重要指标,可综合反映土壤肥力特性和生物活性。【方法】在河南省济源市黄河小浪底生态系统定位站内选择3种人工纯... 【目的】土壤微生物是土壤中重要的存在,土壤中的微生物量碳和微生物量氮能直接或间接参与土壤理化过程,是维持土壤质量的重要指标,可综合反映土壤肥力特性和生物活性。【方法】在河南省济源市黄河小浪底生态系统定位站内选择3种人工纯林,包括刺槐(Robinia pseudoacacia)林、栓皮栎(Quercus variabilis)林和侧柏(Platyclodus orientalis)林,采集未分解枯落物层(L层)、半分解/腐殖化枯落物层(F/H层)以及矿质土层(0~10、10~20 cm)的土壤样品,测定微生物生物量碳(Microbial biomass carbon,MBC)、微生物生物量氮(Microbial biomass nitrogen,MBN)、MBC/MBN以及枯落物层和土壤层总碳(Total carbon,TC)、总氮(Total nitrogen,TN)、可溶性有机碳(Dissolved organic carbon,DOC)和可溶性有机氮(Dissolved organic nitrogen,DON),研究探讨土壤微生物生物量(Soil microbial biomass,SMB)与树种、土深的关系及其机理。【结果】(1)在枯落物层,3种林型的TC最高值均出现在F/H层,而TN的最高值则均出现在L层;3种林型TC和TN均表现为F/H层>L层>0~10 cm、10~20 cm土层,差异显著(P<0.05)。3种林型的DOC表现为枯落物层高于矿质土壤层,DON为矿质土壤层高于枯落物层。枯落物层3种林分之间的DOC含量均表现为栓皮栎林显著高于刺槐林,二者与侧柏林之间差异不显著(P>0.05)。(2)在枯落物层,3种林型的MBC均表现为F/H层高于L层,表现为刺槐林>栓皮栎林>侧柏林。在矿质土层中,3种林型的MBC均为0~10 cm高于10~20 cm土层,表现为栓皮栎林>刺槐林>侧柏林,同一土层的刺槐林和栓皮栎林之间差异不显著(P>0.05)。枯落物层及矿质土层的MBN均表现为栓皮栎林>刺槐林>侧柏林。栓皮栎林在各个土层中均是MBN最高的树种,且与侧柏林之间差异显著(P<0.05)。(3)L和F/H层的MBC/MBN比值相差不大,而在矿质土层中,随土深增加MBC/MBN呈上升趋势。在矿质土层,3种林型MBC/MBN均表现为10~20 cm显著高于0~10 cm;在0~10 cm,3种林型之间差异不显著(P>0.05),在10~20 cm,刺槐林显著高于侧柏林(P>0.05),而与栓皮栎林之间差异不显著(P<0.05)。(4)相关性分析表明,3种林型的MBC均与总碳、总氮呈极显著正相关(P<0.01),其中栓皮栎林MBC与总碳的相关系数最大,为0.959。刺槐林和栓皮栎林的C/N与总碳、总氮呈负相关,而侧柏林的C/N则与总碳、总氮呈正相关,相关系数分别为0.512和0.524。【结论】在华北低丘陵山区种植栓皮栎对土壤的生态恢复效果较好,更有利于生态系统的碳氮循环。 展开更多
关键词 微生物量 微生物量碳 微生物量氮 碳氮比 人工林
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