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环坡深耥大垄豆禾混播治理风蚀穴试验
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作者 刘慧涛 朱平 +4 位作者 赵协哲 孟庆秋 吕耀双 吕鹏飞 修金福 《中国沙漠》 CSCD 北大核心 1997年第4期453-455,共3页
严重风蚀穴(群众称之为风剥板)不均匀分布于流动沙地中,坚硬紧实,单一生物措施难以治理。经采取环坡深耥大垄,运用豆科牧草沙打旺与禾本科谷子混播的方法,使风蚀穴得到了治理,方法简单易行。
关键词 风蚀穴 环坡深耥大垄 豆科牧草 混种 禾本科
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自密封高压阀门坡形环泄漏原因分析及改进措施
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作者 张宗棠 《通用机械》 2005年第11期63-64,共2页
结合自密封阀门的工作原理分析了坡形环泄漏的原因,并提出了升级坡形环材质,加强阀门使用后的热复紧工作以及提高阀门装配精度等改进措施,确保了此类阀门在运行中的可靠度。
关键词 自密封阀门 泄漏 改进措施 泄漏原因分析 高压阀门 自密封 原理分析 装配精度
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摆正规划与领导的关系
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作者 关士 《中外房地产导报》 1999年第24期17-17,共1页
“规划、规划,纸上画画,墙上挂挂,抵不了领导一句话”这种顺口溜之所以畅行至今,表明规划与领导间依然存在某些扭曲。前些年房地产热时那种乱批乱建的火爆和近期中央电视台对贵阳、西安违法建筑曝光反映出来的,不就是这种看法的最好佐证... “规划、规划,纸上画画,墙上挂挂,抵不了领导一句话”这种顺口溜之所以畅行至今,表明规划与领导间依然存在某些扭曲。前些年房地产热时那种乱批乱建的火爆和近期中央电视台对贵阳、西安违法建筑曝光反映出来的,不就是这种看法的最好佐证么? 规划是一个城市(或地区)发展的蓝图,“城市规划必须符合我国国情。 展开更多
关键词 房地产热 滚条 环坡 分级审批制度 城市规划 历吏 开发程序 近期建设 远景发展 最好让
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Study on Original Ecological Tridimensional Slope Vegetation 被引量:2
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作者 YAN Zhi-xin REN Zhi-hua +2 位作者 YAN Chang-ming JIANG Ping WANG Hou-yu 《Journal of Mountain Science》 SCIE CSCD 2013年第6期932-939,共8页
No matter from the perspective of slope protection, landscape effect and construction cost, or from the perspective of ecological benefit, the development of original ecological tridimensional vegetation has become th... No matter from the perspective of slope protection, landscape effect and construction cost, or from the perspective of ecological benefit, the development of original ecological tridimensional vegetation has become the inevitable trend for slope vegetation in pursuit of protecting ecological condition, decreasing soil erosion, maintaining ecological balance and beautifying environment of slope. The concept of original ecological tridimensional slope vegetation is proposed in this paper, and the original ecological tridimensional slope vegetation is studied through theoretical analysis and experiments. Specifically, the mechanical effect of slope vegetation in reinforcing the cohesion and shear strength of soil mass is firstly discussed, and then experiments are performed to study the water interception and containing function of slope under various vegetation conditions. Moreover, the relation between soil moisture and cohesion, the relation between root distribution density and cohesion, and the relation between root distribution density and soil shear strength are also studied based on experiments.Finally, based on field observation, the soil erosion states of slope under various vegetation conditions are comparatively studied. It is found that the original ecological tridimensional slope, which combines grass,shrub and tree, can generate comprehensive slope protection effects, and hence strengthen the slope protection ability and bring multiple slope protection benefits. Thereby, the theoretical foundation for developing original ecological tridimensional slope vegetation is established. 展开更多
关键词 Original ecology Tridimensional slope Slope vegetation
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Vertical patterns in plant diversity and their relations with environmental factors on the southern slope of the Tianshan Mountains(middle section)in Xinjiang(China) 被引量:17
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作者 LIU Bin 《Journal of Mountain Science》 SCIE CSCD 2017年第4期742-757,共16页
The investigation of distribution patterns of species diversity is significant for successful biodiversity conservation. The spatial patterns of vegetation and different life-forms species diversity along an elevation... The investigation of distribution patterns of species diversity is significant for successful biodiversity conservation. The spatial patterns of vegetation and different life-forms species diversity along an elevation gradient in the middle section of the southern slope of the Tianshan Mountains in Xinjiang, China were explored, using the detrended canonical correspondence analysis (DCCA) and the generalized additive model (GAM) methods based on a field survey of 53 sampling plots. In this work 158 species of seed plants were recorded, including 141 herbaceous, 14 shrub, and 2 tree species, in which the woody plants are very limited. 53 sampling plots were classified into 9 major plant communities. The results indicate that the herb communities were the most sensitive to changes in elevation gradient. The diversity indices of the community as a whole presented bimodal patterns. The peak values for the species diversities were found in the transition region between mountain steppe desert and mountain desert steppe (2,200-2,300m), and in the alpine grassland region (2,900-3,100m), while maximum species diversities were in the areas of intermediate environmental gradient. The main environmental factors on the distribution patterns in plant diversity were the elevation, soft water, total nitroeen, available nitrogen, organic matter, and total salt. The response tendency of the four diversity indices for the whole community to the soil environment was the same as that of the herb layers. 展开更多
关键词 Species diversity Distribution pattern Plant community Soil properties Tianshan Mountains
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A discussion of the risks and benefits of using rock terracing to limit soil erosion in Guizhou Province
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作者 杰克.麦孔其 马焕成 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第1期41-47,83,共7页
The construction of stone terraces to minimise soil erosion is common throughout Guizhou. This technique, however, has high inherent risk. Stone terraces are usually much higher than those with earth risers. While th... The construction of stone terraces to minimise soil erosion is common throughout Guizhou. This technique, however, has high inherent risk. Stone terraces are usually much higher than those with earth risers. While they trap a greater thickness of soil on the slope they increase the risk of slope failures, reduce moisture and nutrient availability to plants, and thin more soil up slope. The stone risers also threaten long-term productivity. When a riser collapses debris is deposited over the terrace below making farming difficult. These breaches in the terrace focus surface runoff leading to gully formation and increased sediment transport down slope. Artificial drainage systems, often used in conjunction with terracing, compound the risk. These channels prevent precipitation from soaking into the soil. This limits groundwater and soil moisture recharge which reduces the availability of water for crops and the length of the growing season. The rapid drainage of water from the slope reduces the time of concentration of the catchment resulting in an increase in flood activity. Floods are caused by smaller rainstorm events. They arrive faster and peak quicker and higher than before the channels were constructed. Engineering solutions to soil erosion must therefore be used in conjunction with, and are not as a substitute for, good land management strategies. Furthermore, despite changes in land use practices, and the application of new technologies, there is a maximum amount of production that can be obtained from this land on a sustainable basis. 展开更多
关键词 Soil erosion Reafforestation TERRACING Sustainability LANDSLIDING Environmental management
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Vegetation-environment Relationships Between Northern Slope of Karlik Mountain and Naomaohu Basin,East Tianshan Mountains 被引量:8
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作者 ZHANG Haiyan QIAN Yibing +1 位作者 WU Zhaoning WANG Zhongchen 《Chinese Geographical Science》 SCIE CSCD 2012年第3期288-301,共14页
Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu B... Based on data from 22 sample plots and applying the Canonical Correspondence Analysis (CCA), this paper discusses the vegetation-environment relationships between the northern slope of Karlik Mountain and Naomaohu Ba- sin, which is situated in the easternmost end of the Tianshan Mountains, Xinjiang Uygur Autonomous Region, China. For the zonal vegetation, community diversity of mountain vegetation is higher than that of the desert vegetation due to environmental factors. The CCA ordination diagram revealed that the composition and distribution of vegetation types are mainly determined by altitude, soil pH and soil salt content. With increasing elevation, the soil pH and total salt content decrease but the contents of soil organic matter, soil water, total nitrogen and total phosphorus increase gradu- ally. In the CCA ordination diagrams, the sample plots and main species can be divided into five types according to their adaptations to the environmental factors. Type Ⅰ is composed of desert vegetation distributed on the low moun- tains, hills, plains and deserts below an elevation of 1900 m; type Ⅱ is distributed in the mountain and desert ecotone with an elevation of 1900-2300 m, and includes steppe desert, desert steppe and wetland meadow; type Ⅲ is very sim- ply composed of only salinized meadow; type Ⅳ is distributed above an elevation of 2300 m, containing mountain steppe, meadow steppe, subalpine meadow and alpine meadow; type Ⅴ only contains salinized meadow. The results show that with increasing elevation, species combination changes from the xerophytic shrubs, semi-shrubs and herbs distributed in the low altitude zone with arid climate to the cold-tolerant perennial herbs growing in the high altitudinal zone with cold climate. 展开更多
关键词 vegetation pattern environmental factors canonical correspondence analysis (CCA) vegetation-environment relationships Tianshan Mountains XINJIANG
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Comparison of Single Loop and Dual Loop PP Reactors and PP Product Development
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作者 Lu Yunfeng Jiang Rong Feng Suogui(Yan’an Petroleum Refining Industrial Group, Jiaokouhe Township, Luochuan County,Shaanxi 727406) 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2003年第2期33-38,共6页
The present status of PP technology in China is presented. Through a review of single loop and dual loop PP reactor technology as well as development and utilization of PP products it is concluded that import of PP te... The present status of PP technology in China is presented. Through a review of single loop and dual loop PP reactor technology as well as development and utilization of PP products it is concluded that import of PP technology should be based on the demand of PP products and market trend with consideration of local conditions. The existing problems and future development of PP technology in China are discussed. 展开更多
关键词 POLYPROPYLENE technology PRODUCT REVIEW
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Risk Assessment of Disaster Chain: Experience from Wenchuan Earthquake-induced Landslides in China 被引量:6
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作者 ZHOU Hong-jian WANG Xi YUAN Yi 《Journal of Mountain Science》 SCIE CSCD 2015年第5期1169-1180,共12页
This paper deals with the formative process of the Wenchuan earthquake disaster chain risk. Selected earthquake-landslides chain risk is critically evaluated by the probability of landslide displacement failure based ... This paper deals with the formative process of the Wenchuan earthquake disaster chain risk. Selected earthquake-landslides chain risk is critically evaluated by the probability of landslide displacement failure based on the Newmark's permanent-deformation model. In this context, a conceptual model of regional disaster chain risk assessment was proposed, in which the hazardformative environments sensitivity was the core factor as well as the main difference compared with single disaster risk assessment. The disaster chain risk is accumulation of primary disaster risk and the secondary disasters risks. Results derived from the Wenchuan case proved that the conceptual model was suitable for the disaster chain risk assessment, especially the sudden disaster chain. This experience would offer greater potential in application of conceptual model of disaster chain risk assessment, in the process of large-scale disaster risk governance. 展开更多
关键词 Disaster chain Risk assessment Wenchuan Earthquake LANDSLIDE
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Geospatial susceptibility mapping of earthquake-induced landslides in Nuweiba area, Gulf of Aqaba, Egypt 被引量:1
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作者 Sara ABUZIED Samia IBRAHIM +1 位作者 Mona KAISER Tarek Saleem 《Journal of Mountain Science》 SCIE CSCD 2016年第7期1286-1303,共18页
Earthquake induced landslides are one of the most severe geo-environmental hazards that cause enormous damage to infrastructure, property, and loss of life in Nuweiba area. This study developed a model for mapping the... Earthquake induced landslides are one of the most severe geo-environmental hazards that cause enormous damage to infrastructure, property, and loss of life in Nuweiba area. This study developed a model for mapping the earthquake-induced landslide susceptibility in Nuweiba area in Egypt with considerations of geological, geomorphological, topographical, and seismological factors. An integrated approach of remote sensing and GIS technologies were applied for that target. Several data sources including Terra SAR-X and SPOT 5 satellite imagery, topographic maps, field data, and other geospatial resources were used to model landslide susceptibility. These data were used specifically to produce important thematic layers contributing to landslide occurrences in the region. A rating scheme was developed to assign ranks for the thematic layers and weights for their classes based on their contribution in landslide susceptibility. The ranks and weights were defined based on the knowledge from field survey and authors experiences related to the study area. The landslide susceptibility map delineates the hazard zones to three relative classes of susceptibility: high, moderate, and low. Therefore, the current approach provides a way to assess landslide hazards and serves for geo-hazard planning and prediction in Nuweiba area. 展开更多
关键词 Geographic Information Systems(GIS) Remote Sensing(RS) Landslides Susceptibility mapping Weights Nuweiba area
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A Study on the Estimation of Ship Waves Interaction with the Sloping Banks of the Channel
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作者 Igor Chicherin Alexander Pustoshny 《Journal of Shipping and Ocean Engineering》 2012年第3期165-174,共10页
The problem of shore wash in environmental engineering is connected in particular with the effect of waves generated by the ships and fast speed boats. Another problem is protection of "Marines" with anchored boat a... The problem of shore wash in environmental engineering is connected in particular with the effect of waves generated by the ships and fast speed boats. Another problem is protection of "Marines" with anchored boat against waves. Sloping banks provoke unfavorable transformation of waves. Simultaneously sloping bank is the factor which significantly complicates prediction of wave pattern in numerical analysis. The purpose of present paper is to demonstrate the results of numerical investigation of ship waves pattern in constrain water area with slope banks by panel method for non-linear ship waves calculation usually applied for ship hull perfection as routine instrument of towing tanks technology. The method initially developed for calculation of ship hull waves in inviscid infinite fluid was adapted to meet boundary conditions on slope banks. Verification of the method was done for 60-series ship in rectangular channel. Development of wave pattern generated by two ship of different types--monohull ferries and river catamaran was investigated. It was found that ship waves height significantly increased due to slopping banks comparing with case of deep water and shallow water rectangular channel. 展开更多
关键词 Shore wash slopping bank ship waves nonlinear panel method.
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Effects of Moisture Content on Cyclic Shear Properties of Soils during Epicentral Earthquakes
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作者 Hirofumi Toyota Ayaka Susami Susumu Takada 《Journal of Civil Engineering and Architecture》 2011年第12期1091-1102,共12页
Numerous landslides occurred in hilly and mountainous areas during the 2004 Niigata-ken Chuetsu Earthquake. Social problems developed when many towns became isolated because landslides cut offtraffic and public servic... Numerous landslides occurred in hilly and mountainous areas during the 2004 Niigata-ken Chuetsu Earthquake. Social problems developed when many towns became isolated because landslides cut offtraffic and public service lifelines. The hilly areas are composed mainly alternate layer of soft sandstone and mudstone deposited in quaternary or tertiary period. This geomorphology formed by folding presents a prominent landslide area in this region. This area has been utilized as rice terraces or carp breeding ponds because of plenty of water in the ground all the time. In addition, there was rainfall of more than 100 mm caused by Typhoon No. 23 two days before the earthquake in Chuetsu area. Block samples were extracted from the failure sites. The samples obtained were mainly low-cemented sandy soils. Triaxial tests of the samples under saturated and unsaturated conditions were conducted to examine the soils' strength properties and estimate the indices for slope stability. 展开更多
关键词 Triaxial test unsaturated soil LANDSLIDE site investigation GEOLOGY
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Landslide Disaster Vulnerability in Western Kenya and Mitigation Options: A Synopsis of Evidence and Issues of Kuvasali Landslide
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作者 B.K. Rop 《Journal of Environmental Science and Engineering》 2011年第1期110-115,共6页
The Kuvasali landslide disaster in Malava, Western Kenya, which caused harmful geo-environmental hazards to the villagers in August 2007, formed the premise of this paper. The existing landslide vulnerability occurren... The Kuvasali landslide disaster in Malava, Western Kenya, which caused harmful geo-environmental hazards to the villagers in August 2007, formed the premise of this paper. The existing landslide vulnerability occurrence ratings have been identified and documented using participatory approaches to ascertain the adoptive indigenous methods, which helped mitigation against the negative impacts by determining the slope steepness using Abney level. The geological set up, settlement and climatic factors, relating to landslides, revealed that the affected homesteads were on a steep slope of approximately 70%, with underlying metamorphosed basement rocks comprising ofgneisses, schists and granite intrusions. The steep escarpment overlying these rocks, where the landslide occurred, consists of volcanic rocks and black cotton clayey soils. The slope has scattered vegetation cover due to farming, while the low-lying area is planted with sugar cane and maize plantations. The landslide disaster led to loss of lives, injuries and damage to property. Natural resources, including water points, suffered siltation. Mitigation measures such as geo-hazard mapping and zoning, awareness training and campaigns for the local people focusing on hazard-prone areas resulting from poor land use practices have been recommended. 展开更多
关键词 LANDSLIDE land use SLOPE
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官田养鸡人
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作者 陆灯光 《今日海南》 1999年第10期46-46,共1页
我到官田村去,去看那些养鸡的人。地处东方市三家乡南面的这个村子。三面环坡。坡上是一片一片的青草地和一片一片的灌木林。官田村的人,就在这一面面坡上放养着鸡,就象人们在荒坡野地上放牧着牛羊一样。这是一种非常独特的、园林式的... 我到官田村去,去看那些养鸡的人。地处东方市三家乡南面的这个村子。三面环坡。坡上是一片一片的青草地和一片一片的灌木林。官田村的人,就在这一面面坡上放养着鸡,就象人们在荒坡野地上放牧着牛羊一样。这是一种非常独特的、园林式的饲养法,是他们的一大创造。因为传统的群鸡饲养法,都是圈养在鸡舍里,并且给鸡喂的都是从市面上买来的精饲料。现在他们改变了这种方法,在坡上放养,使鸡的活动范围广了,既可觅到草地上的昆虫吃,又有人工喂给它们谷粒等粗粮。这样喂养起来的鸡,肉质非常细嫩、香甜,比起饲料鸡来,真不知要强多少倍。拿自己养的鸡和饲料鸡作一番比较后,他们自豪地说:"拿10只饲料鸡来换我们的1只,我们也不愿意哩。"正因为这样, 展开更多
关键词 养鸡 官田 精饲料 灌木林 放养 肉质 饲养法 环坡 青草
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装置新人推介刘成英 张蕾 滕菲
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作者 淅雨 《艺术界》 1997年第6期54-55,共2页
刘成英 四川成都艺术家 他的这件作品考虑的是人与环境的关系。他曾在作品里说:“动物一旦落入陷井,本能会使它们挣扎,那是现实中的真实。那么在比拟的空间、用几十年、甚至几百年的过程才落入人类为自己设置的‘陷井’,为何不考虑走出... 刘成英 四川成都艺术家 他的这件作品考虑的是人与环境的关系。他曾在作品里说:“动物一旦落入陷井,本能会使它们挣扎,那是现实中的真实。那么在比拟的空间、用几十年、甚至几百年的过程才落入人类为自己设置的‘陷井’,为何不考虑走出‘陷井’,或者根本不让‘陷井’产生?” 展开更多
关键词 陷井 新人 作品 蝴蝶 油漆 档案 人与 环坡 曲别针 回形针
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女儿绿
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作者 李华章 《长江文艺》 1996年第4期70-70,共1页
我在五峰茶山深入生活,前前后后一年有余,以产茶著名的菜花、九环坡、水沢司、香沟、春光都留下过我的足迹;而那里的茶园和茶农也深深地印在我的心里。岁月似乎没有弃我而去,我依然强烈地回味着那云雾茶的清香和魅力。到茶山泡了这么长... 我在五峰茶山深入生活,前前后后一年有余,以产茶著名的菜花、九环坡、水沢司、香沟、春光都留下过我的足迹;而那里的茶园和茶农也深深地印在我的心里。岁月似乎没有弃我而去,我依然强烈地回味着那云雾茶的清香和魅力。到茶山泡了这么长时间,品尝过著名的珍眉、毛尖、炒青,但至今遗憾的是我未曾品尝过名叫“ 展开更多
关键词 长时间 深入生活 茶园 茶农 品尝 云雾茶 环坡 峰茶 炒青 足迹
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Effects of Slope Aspects on Soil Bacterial and Arbuscular Fungal Communities in a Boreal Forest in China 被引量:17
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作者 CHU Haiyan XIANG Xingjia +4 位作者 YANG Jian Jonathan M. ADAMS ZHANG Kaoping LI Yuntao SHI Yu 《Pedosphere》 SCIE CAS CSCD 2016年第2期226-234,共9页
The effects of slope aspects on soil biogeochemical properties and plant communities in forested environments have been studied extensively; however, slope aspect influence on soil microbial communities remains largel... The effects of slope aspects on soil biogeochemical properties and plant communities in forested environments have been studied extensively; however, slope aspect influence on soil microbial communities remains largely unexamined, despite the central role of soil biota in ecosystem functioning. In this study, the communities of both soil bacteria and arbuscular mycorrhizal fungi (AMF) were investigated using tagged pyrosequencing for three types of slope aspects (south-facing aspect, north-facing aspect and flat area) in a boreal forest of the Greater Khingan Mountains, China. The bacterial and AMF community composition differed with slope aspects. Bacterial diversity was the lowest on the north-facing aspect, and AMF diversity was the lowest on the flat area. Aspects also had a significant impact on soil pH and available phosphorus (P) and shrubby biomass. Soil pH and understory shrub biomass were significantly correlated with bacterial communities, and soil available P and shrub biomass showed significant correlations with AMF communities. Our results suggested that slope aspects affected bacterial and AMF communities, mediated by aspect-induced changes in plant community and soil chemical properties (e.g., pH and available P), which improved the knowledge on the effects of forest slope aspects on aboveground and belowground communities. 展开更多
关键词 available P plant communities PYROSEQUENCING shrubby biomass soil chemical properties soil microbial communities soil pH
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Prey availability, prey selection, and trophic niche width in the lizard Psammodromus algirus along an elevational gradient 被引量:2
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作者 Gregorio MORENO-RUEDA Elena MELERO +2 位作者 Senda REGUERA Francisco J, ZAMORA-CAMACHO Ines ALVAREZ-BENITO 《Current Zoology》 SCIE CAS CSCD 2018年第5期603-613,共11页
Mountains imply enormous environmental variation, with alpine habitats entailing harsh environ- ments, especially for ectotherms such as lizards. This environmental variability also may imply variation in prey availab... Mountains imply enormous environmental variation, with alpine habitats entailing harsh environ- ments, especially for ectotherms such as lizards. This environmental variability also may imply variation in prey availability. However, little is known about how lizard trophic ecology varies with elevation. In this study, we analyze diet, prey availability, prey selection, and trophic niche width in the lacertid lizard Psammodromus algirus along a 2,200-m elevational gradient in the Sierra Nevada (SE Spain). The analysis of fecal samples has shown that Orthoptera, Formicidae, Hemiptera, Coleoptera, and Araneae are the main prey, although, according to their abundance in pitfall traps, Formicidae and Coleoptera are rejected by the lizard whereas Orthoptera, Hemiptera, and Araneae are preferred. Prey abundance and diversity increase with elevation and diet subtly varies along with the elevational gradient. The consumption of Coleoptera increases with elevation probably as a consequence of the lizard foraging more in open areas while basking. The electivity for Araneae increases with elevation. Araneae are rejected in the lowlands--where they are rela- tively abundant--whereas, at high elevation, this lizard positively selects them, despite they being less abundant. The lizard trophic niche width expands with elevation due to concomitant greater prey diversity and hence this lizard feeds on more prey types in highlands. Although no sex difference in diet has been found, the trophic niche is broader in females than males. As a whole, alpine lizards show a trophic niche simitar to that found at lower elevat(ons, suggesting that P. algirus is well adapted to the harsh environment found in alpine areas. 展开更多
关键词 alpine habitats arthropods mountain ecology niche variation hypothesis trophic ecology
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AUV Based Source Seeking with Estimated Gradients 被引量:4
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作者 LI Zhuo YOU Keyou SONG Shiji 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2018年第1期262-275,共14页
This paper addresses the source seeking problems for an autonomous underwater vehicle(AUV) with the estimated gradients. The AUV is embedded with multiple sensors, which are only able to detect the signal strengths ... This paper addresses the source seeking problems for an autonomous underwater vehicle(AUV) with the estimated gradients. The AUV is embedded with multiple sensors, which are only able to detect the signal strengths of the source with unknown distribution. To resolve this challenge,a sensor configuration is explicitly designed as a semicircle to estimate gradients of the signal field.Then, a controller is obtained via the estimated gradients to drive the AUV to approach the source.Moreover, an upper bound for the localization error is provided in terms of the radius of the semicircle and the signal distribution. Finally, the authors include a simulation example by applying the strategy to a Remote Environmental Monitoring Unit S(REMUS) for seeking the deepest point of a region of seabed in the South China Sea. 展开更多
关键词 AUV dynamics gradient estimation source seeking
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Serpulids and their paleoecology of the Paleogene Kalatar Formation in southwest Tarim Basin of China 被引量:1
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作者 YANG HaiJun SHEN JianWei +3 位作者 ZHANG LiJuan LI Meng HUANG ZhiBin WANG Yue 《Science China Earth Sciences》 SCIE EI CAS 2012年第7期1087-1100,共14页
Polychaete serpulids are globally distributed tubeworms mostly in marine environments from Late Triassic to modem time. These calcareous tubeworms could be rock-forming, reef-building, or a principal fouling organism ... Polychaete serpulids are globally distributed tubeworms mostly in marine environments from Late Triassic to modem time. These calcareous tubeworms could be rock-forming, reef-building, or a principal fouling organism in harbor and bays. Car- bonates of the Paleogene Kalatar Formation in southwest Tarim Basin yield abundant serpulid fossils, which, together with oyster fossils, constitute the characteristic fossil assemblage of the Kalatar Formation. Other common fossils include bivalves, gastropods, ostracods, echinoderms, and bryozoans. Lithologies that yielded serpulid fossils are characterized by micritic bio- clastic limestone, sandy limestone, and shelly limestone, indicating a semi-restricted to open shallow marine environment with medium to low water energy. The research data about serpulids and their fossil materials from China are relatively rare. Based on the studies of tbssils taxonomy, community palaeoecology, and fossil taphonomy, this paper analyzed and studied the types, occurrence, distribution, and morphological characteristics of serpulids and their palaeoecological features in the Kalatar For- mation. Two serpulid community compositions were recognized in the Kalatar Formation, including a rock-forming Ditrupa community and a cluster-growth Propomatoceros community. The Ditrupa community was distributed in coastal environment of the west Kunlun piedmont, lived on sandy hard substrates with little mud, and rarely occurred in lagoon and tidal settings. The Propomatoceros community occurred in offshore middle carbonate ramp in the piedmont of the south Tianshan Moun- tains and in offshore shelf in the piedmont of the west Kunlun Mountains. According to the analysis on the host-rock litholo- gies, preservation and symbionts, it is inferred that serpulids in the Kalatar Formation grew on the oyster shell or other hard substrate, and they did not form reefs or bioherms. 展开更多
关键词 serpulids PALAEOECOLOGY Kalatar Formation PALEOGENE southwest Tarim Basin
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