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造沙大亨和它的梦想
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作者 叶军 《我们爱科学》 2010年第22期14-17,共4页
造沙大亨的造沙厂 你是来参观俺的造沙厂的?好好,欢迎欢迎!不用找了,俺的身体就是造沙厂。不信?俺给你现场表演一下。看到那边大丛大丛的珊瑚了没?那就是俺的造沙原料。俺先游过去在珊瑚上啃两口,过一会儿,俺就会排出又白又细... 造沙大亨的造沙厂 你是来参观俺的造沙厂的?好好,欢迎欢迎!不用找了,俺的身体就是造沙厂。不信?俺给你现场表演一下。看到那边大丛大丛的珊瑚了没?那就是俺的造沙原料。俺先游过去在珊瑚上啃两口,过一会儿,俺就会排出又白又细的珊瑚沙了。怎么样,没骗你吧,看看,是不是又细又白的珊瑚沙?神奇吧? 展开更多
关键词 鹦嘴鱼 造沙大亨” 珊瑚 习性
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酱香型白酒润粮方式对基酒产质的影响
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作者 官常清 张福荣 +1 位作者 甘霖耀 杨明 《酿酒科技》 2024年第11期82-85,共4页
酱香型白酒的酿造工艺中,下沙、造沙润粮是关键的起始步骤,对后续的蒸煮糊化过程,乃至整个制酒生产结果都起到了决定性的作用。文章综述了生产过程中润粮方式不同对白酒产质、白酒风味物质的影响,同时展望了润粮新技术方法的实践应用与... 酱香型白酒的酿造工艺中,下沙、造沙润粮是关键的起始步骤,对后续的蒸煮糊化过程,乃至整个制酒生产结果都起到了决定性的作用。文章综述了生产过程中润粮方式不同对白酒产质、白酒风味物质的影响,同时展望了润粮新技术方法的实践应用与未来发展,用于酱香型白酒生产中,可提高对生产过程的控制和基酒产质,以及保护、提高基酒风味物质的产生。 展开更多
关键词 酱香型白酒 造沙 润粮方式
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柴东北缘上古生界砂砾岩碎屑组分特征及其物源构造属性 被引量:1
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作者 孙娇鹏 陈世悦 +3 位作者 庄毓凯 刘金 胡忠亚 马帅 《地质力学学报》 CSCD 北大核心 2015年第4期463-472,共10页
基于柴东北缘德令哈地区上古生界126件碎屑岩样品的镜下鉴定,结合对牦牛山组、城墙沟组、怀头他拉组、克鲁克组及扎布萨尕秀组砂砾岩岩石学特征、沉积特征的野外调查,研究柴达木东北部地区晚古生代碎屑岩物源区,并在此基础上进一步讨论... 基于柴东北缘德令哈地区上古生界126件碎屑岩样品的镜下鉴定,结合对牦牛山组、城墙沟组、怀头他拉组、克鲁克组及扎布萨尕秀组砂砾岩岩石学特征、沉积特征的野外调查,研究柴达木东北部地区晚古生代碎屑岩物源区,并在此基础上进一步讨论该地区晚古生代盆山格局.研究结果表明,柴东北缘德令哈地区晚古生代主要发育扇三角洲-障壁海岸沉积体系,砂砾岩碎屑颗粒结构成熟度较低,重力流证据普遍存在;各层段砂砾岩碎屑颗粒中Q/(R+F)值在1.89~3.74之间,呈现低成分成熟度特点.碎屑颗粒组成及近物源沉积证据一致表明,研究区晚古生代以鱼卡—沙柳河加里东期造山带为主要物源区.该造山带至少存在了195 Ma,包括距今465~430 Ma的山体隆升与距今430 ~270 Ma的山体剥蚀阶段.柴达木海盆与德令哈海盆是两个独立的海盆,发育展布方向完全相反的沉积体系.同时,德令哈地区上古生界含油气系统勘探应将鱼卡河—沙柳河高压—超高压变质带视为勘探边界. 展开更多
关键词 晚古生代 碎屑颗粒组分 物源分析 鱼卡—柳河山带 属性
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Effect of biological agents on survival rate and root growth of Scots Pine seedlings 被引量:4
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作者 唐凤德 梁永君 +2 位作者 韩士杰 宫伟光 丁宝永 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第2期124-126,i002,共4页
Two-year-old Scots pine (Pinus sylvstris var.mongolica) seedlings were treated with Pt mycorrhiza powder, ABT root-growing powder, HRC water-absorbing agent and high-yield powder, and planted on the sandy land in Bali... Two-year-old Scots pine (Pinus sylvstris var.mongolica) seedlings were treated with Pt mycorrhiza powder, ABT root-growing powder, HRC water-absorbing agent and high-yield powder, and planted on the sandy land in Balinyouqi, Inner Mongolia (180°12′13″E and 43°13′05″N). The effect and function of these biological agents on survival rate of seedlings were tested and analyzed by measuring the fine root growth and gross root growth. The results showed that the survival rates of the seedlings treated with Pt3, ABT, and HRC biological agents increased by 29.3%, 23.6%, and 16%, respectively. The regression analysis revealed that the length of fine roots (<2 mm) was positively correlated with seedling survival rate, which means that the Pt3 powder, ABT foot-growing powder and HRC water-absorbing powder increased the survival rates of the seedlings by promoting the growth of fine roots. Keywords Biological agents - Pinus sylvstris var.mongolica - Sandy soil - Roots - Survival rate CLC number S723.1 - S791.253 Document code A Foundation item: This article was supported by the National Natural Science Foundation of China (No. 39970627).Biography: TANG Feng-de (1967-), male, Ph. Doctor in Institute of Applied Ecology. Chinese Academy of Sciences, Shenyang 110016, P. R. China.Responsible editor: Zhu Hong 展开更多
关键词 Biological agents Pinus sylvstris var.mongolica Sandy soil ROOTS Survival rate
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Analysis and assessment of land desertification in Xinjiang based on RS and GIS 被引量:5
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作者 LIHu WANGXiaofeng GA0Yaqi 《Journal of Geographical Sciences》 SCIE CSCD 2004年第2期159-166,共8页
The land desertification in Xinjiang was monitored and analyzed based on RS and GIS techniques. Satellite data interpretation was adopted to obtain the general situation of Xinjiang’s land desertification in assistan... The land desertification in Xinjiang was monitored and analyzed based on RS and GIS techniques. Satellite data interpretation was adopted to obtain the general situation of Xinjiang’s land desertification in assistance with the sampling method and on-the-spot investigations. Related monitoring and investigations showed that Xinjiang was facing with severe wide range land desertification, and its desertified area made up 77.08% of the total monitoring area. As for land types, the desertified farmland accounted for 1.92% of the total monitoring area, desertified woodland 4%, desertified grassland 45%, and unused land 49%. Accordingly, as for desertification degrees, non-desertified land occupied 22.92%, weak desertified land 5.69%, medium-degree desertified land 16.58%, severe desertified land 33.19% and super severe desertified land 21.61%. Finally, as for inducing factors, wind-eroded desertification made up 58.23%, water-eroded desertification 8.69%, salinization desertification 6.52% and frozen-melt eroded desertification 3.64%. Xinjiang’s land desertification tended to get worse and the harnessing mission remained hard. 展开更多
关键词 XINJIANG land desertification remote sensing GIS monitoring and analysis
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Soil animals and nitrogen mineralization under sand-fixation plantations in Zhanggutai region,China 被引量:8
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作者 CHEN Fu-sheng ZENG De-hui +2 位作者 HU Xiao-fei CHEN Guang-sheng YU Zhan-yuan 《Journal of Forestry Research》 SCIE CAS CSCD 2007年第1期73-77,共5页
The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distin... The effects of soil animals on soil nitrogen (N) mineralization and its availability were studied by investigating soil animal groups and their amounts of macro-faunas sorted by hand, and middle and microfaunas distinguished with Tullgren and Baermann methods under three Pinus sylvestris var. mongolica Litv. plantations in Zhanggutai sandy land, China. In addition, soil N mineralization rate was also measured with PVC closed-top tube in situ incubation method. The soil animals collected during growing season belonged to 13 orders, 5 groups, 4 phyla, whose average density was 86 249.17 individuals·m^(-2). There were significant differences in soil animal species, densities, diversities and evenness among three plantations. Permanent grazing resulted in decrease of soil animal species and diversity. The average ammonification, nitrification and mineralization rates were 0.48 g·m^(-2)·a^(-1), 3.68 g·m^(-2)·a^(-1) and 4.16 g·m^(-2)·a^(-1), respectively. The ammonification rate in near-mature forest was higher than that in middle-age forests, while the order of nitrification and net mineralization rates was: middle-age forest without grazing < middle-age forest with grazing < near-mature forest with grazing (P<0.05). Soil N mineralization rate increased with soil animal amounts, but no significant relationship with diversity. The contribution of soil animals to N mineralization was different for different ecosystems due to influences of complex factors including grazing, soil characteristics, the quality and amount of litter on N mineralization. 展开更多
关键词 Soil animals N mineralization Pinus sylvestris var. mongolica Litv. Zhanggutai sandy land
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Late Cenozoic Tectonic Deformation in the Dongsha Islands and Adjacent Sea Area 被引量:6
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作者 吴时国 刘展 +3 位作者 王万银 郭军华 T.Lüdmann H.K.Wong 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2003年第4期377-388,共12页
Dongsha Island and the adjacent sea area locate at the northern continental margin of the South China Sea (SCS), and is connected to the east by the Manila Trench. Analyses of seismic stratigraphy and gravity, magneti... Dongsha Island and the adjacent sea area locate at the northern continental margin of the South China Sea (SCS), and is connected to the east by the Manila Trench. Analyses of seismic stratigraphy and gravity, magnetic and drilling wells data led to the discovery of three post fault sequences (V, VI, VII). Extensive tectonic uplift, magma activity and erosion occurred in Dongsha Island and the adjacent area, where most of the faults in the northeastern SCS were still active during Pliocene and Quaternary. Two groups of faults trending NEE and NW were developed during Late Cenozoic. We conclude that three important tectonic movements, especially Dongsha movement (4.4-5.2 Ma) and Liuhua movement (1.4-1.89 Ma), controlled the structural framework in the Dongsha rise; whose deformation in the east is stronger than that in the west and whose stress field variation suggests that the tectonic uplift in the study area contributed to magmato tectonic events correlated to the main collision phases between the East China and Taiwan 5-3 and 3-0 Ma ago. 展开更多
关键词 Late Cenozoic tectonic movement seismic stratigraphy plate collision South China Sea
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Surface Macrofabric of Boulder Dominated Desert Mountain Slopes, California, USA
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作者 Donald A. FRIEND 《Journal of Mountain Science》 SCIE CSCD 2005年第3期181-192,共12页
Rhyolite domes formed over a million year continuum in eastern California are used to study boulder dominated slopes. Slopes in this study are steep (-25°to-35°) and are made of coarse boulder sized blocks... Rhyolite domes formed over a million year continuum in eastern California are used to study boulder dominated slopes. Slopes in this study are steep (-25°to-35°) and are made of coarse boulder sized blocks. These slopes include well varnished vertically oriented colluvial deposits that have been likened to relict periglacial stone stripes, or as indicated in this study, are the result of ongoing desert slope processes. The deposits are common throughout the arid southwestern US, but their morphometric character, fabric, and rates of formation have not been assessed systematically. Results indicate that boulder deposits examined here are remnant from the original surface formed during volcanic eruption and that these boulder slope deposits evolve slowly. Grain size, grain shape and grain angularity do not change significantly from genesis to -0.6 Ma; trends in the data change markedly after that time. Mean eigenvectors indicate a fabric oriented downhill, parallel to the slope, consistent with the visual impression that long thin to plate-like rocks orient themselves similarly; however, fabric is actually randomly dispersed, similar to that at slope genesis, as indicated by the eigenvalue analysis resultants of C and K. Interestingly, grainsremain or become more angular over the million-year time scale of the study as they decrease in size, indicating active in situ weathering processes on individual grains; this result is counter to the common assumption that as grains weather they become more rounded over time. 展开更多
关键词 Boulder-fields desert-slopes macrofabric
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A Rapid Assessment of Scleractinian and Non-Scleractinian Coral Growth Forms Along the Saudi Arabian Coast, Red Sea
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作者 Abdulmohsin A.Al-Sofyani N.Marimuthu J.Jerald Wilson 《Journal of Ocean University of China》 SCIE CAS 2014年第2期243-248,共6页
In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Is... In this study we assessed the current status of coral reefs along the Saudi Arabian coast of the Red Sea. Among the three growth forms of Acroporid corals, the branching forms were found to dominate in the Farassan Islands (44.55%±11.10% cover) fol-lowed by tabular forms in the Doga Islands (ranging between 18%±6.47% and 18.30%±9.47% cover). Digitate forms were rarely found along the coast except at Maqna. Among the five growth forms of non-Acroporid corals, we observed maximum cover of branching forms in the Yanbu offshore area (58.89%±15.11% cover) followed by the Jeddah coast (24.76%±14.04% cover). The Millepora spp., a non-Scleractinian coral, was abundant at all the near-shore sites, such as Jeddah (10.70%±8.21%) and A1-Wajh (9.81%±6.69%). The live coral cover (including both Scleractinian and non-Scleractinian corals) of Saudi Red Sea coast was seen to be higher in the north and gradually decrease towards the south. Principal Component analysis showed that the contribution of Acro- porid corals was greater in the southern region than in the northem and middle regions, but vice-versa in the case of non-Acroporid corals. Bray-Curtis cluster analysis categorized all the study sites into two major clusters with 60% similarity. Among them, one cluster-forming sites from Maqna to Masturah (Northem region) and the second one comprised the middle and southem regions (Jeddah to Farassan Islands), and one outlier Rabigh. 展开更多
关键词 coral reef growth forms Saudi Arabia coral diversity scleractinian coral Red Sea
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The Influence of Surface Morphology of Dense Ca-P Ceramics on Apatite Formation in Dynamic SBF
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作者 段友容 许森 +1 位作者 陈继镛 张兴栋 《Journal of Donghua University(English Edition)》 EI CAS 2005年第4期63-66,共4页
This study aimed at exploring the effect of surface morphology of dense phosphate calcimn (Ca-P) ceramics upon the formation of bone-like apatite in static or dynamic simulated body fluid (SBF). Dense and sandblas... This study aimed at exploring the effect of surface morphology of dense phosphate calcimn (Ca-P) ceramics upon the formation of bone-like apatite in static or dynamic simulated body fluid (SBF). Dense and sandblasted calcium phosphate ceramics were immersed into dynamic SBF flowing at normal physiological speed of body fluid of skeletal muscle. The changes were characterized using SEM, XPS, IR and XRD. Changes can be observed after the sandblasted surface of dense calcium phosphate ceramics had been immersed in SBF for 14 days. XPS analysis results showed that the flake-like structure was composed of Ca, P, C, O; IR analysis result of surface structure of samples showed that there were specific peaks for CO3^2-; XRD results indicated the decrease in crystallinity and the increase in amorphous structure. The rough surface was advantageous for the formation of bone-like apatite. Increasing the Ca^2+, HPO4^2- concentration of SBF could also enhance the bonelike apatite formation. All the results demonstrated that local concentration is a key factor affecting nucleation. 展开更多
关键词 Dense calcium phosphate ceramics sandblasted surface dynamic SBF bone-like a patite
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Change of Soil Organic Carbon after Cropland Afforestation in ′Beijing-Tianjin Sandstorm Source Control′ Program Area in China 被引量:6
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作者 ZENG Xinhua ZHANG Wanjun +6 位作者 LIU Xiuping CAO Jiansheng SHEN Huitao ZHAO Xin ZHANG Nan-nan BAI Yuru Yi Mei 《Chinese Geographical Science》 SCIE CSCD 2014年第4期461-470,共10页
Land use change is one of the major factors that affect soil organic carbon (SOC) variation and global carbon balance. However, the effects of land use change on SOC are always variable. In this study, using a serie... Land use change is one of the major factors that affect soil organic carbon (SOC) variation and global carbon balance. However, the effects of land use change on SOC are always variable. In this study, using a series of paired-field experiments, we estimated the effects of revegetation types and environmental conditions on SOC stock and vertical distribution after replacement of cropland with poplar (Populus tomentosa) and korshinsk peashrub (Caragana korshinskt'i) in three climate regions (Chifeng City, Fengning City and Datong City of the 'Beijing-Tianjin Sandstorm Source Control' (BTSSC) program area. The results show that SOC sequestration rate ranges from 0.15 Mg/(ha-yr) to 3.76 Mg/(ha-yr) in the soil layer of 0-100 cm in early stage after cropland afforestation in the BTSSC program area. The SOC accumulation rates are the highest in Fengning for both the two vegetation types. Compared to C. korshinskii, P tomentosa has greater effects on SOC accumulation in the three climate regions, but significantly greater effect only appears in Datong. The SOC density increases by 20%-111% and 15%-59% for P. tomentosa and 9%-63% and 0-73% for C. korshinskii in the 0-20 cm and 20-100 cm soil layers, respectively. Our results indicate that cropland afforestation not only affects SOC stock in the topsoil, but also has some effects on subsoil carbon. However, the effect of cropland afforestation on SOC accumulation varied with climate regions and revegetation types. Considering the large area of revegetation and relatively high SOC accumulation rate, SOC sequestration in the BTSSC program should contribute significantly to decrease the CO2 concentration in the atmosphere. 展开更多
关键词 soil organic carbon (SOC) cropland afforestation soil profile carbon sequestration Beijing-Tianjin Sandstorm SourceControl program
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Simulation study on copper and zinc release from contaminated sandy soils due to acidification
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作者 ZHANG Ming-kui D.V. CALVERT 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第4期289-292,共4页
Afforestation in sandy soils can cause soil acidification and affect Cu and Zn release. The behaviors of Cu and Zn release from contaminated arable sandy soils were investigated in the laboratory with the methods of s... Afforestation in sandy soils can cause soil acidification and affect Cu and Zn release. The behaviors of Cu and Zn release from contaminated arable sandy soils were investigated in the laboratory with the methods of simulated acidification of the soils. The results showed that soil acidification could change chemical forms of Cu and Zn in the soils, impel the transformation of Cu and Zn from carbonate associated fractions to exchangeable, organic matter and oxides associated fractions, and thus increase the release potential of Cu and Zn in the soils. The effect of the acidification on Zn leaching was more significant than that of Cu. Water solubility of Cu and Zn in the soils was increased with decreasing pH, and the solubility of Cu and Zn was increased exponentially at pH 3.8-4.5, and 6.2-6.5, respectively. 展开更多
关键词 COPPER ZINC Contaminated sandy soil ACIDIFICATION AFFORESTATION
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Comparative Study of Self-Compacting Concrete with Manufactured and Dune Sand
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作者 Leila Zeghichi Zeid Benghazi Laid Baali 《Journal of Civil Engineering and Architecture》 2012年第10期1429-1434,共6页
Sand is an inert element essential in the composition of concrete; its use ensures granular continuity between the cement and gravel for better cohesion of concrete. This paper presents the results of a study that inv... Sand is an inert element essential in the composition of concrete; its use ensures granular continuity between the cement and gravel for better cohesion of concrete. This paper presents the results of a study that investigated the influence of sand quality on the properties of fresh and hardened SCC (self-compacting concrete). The dune sands are very fine materials characterized by a high intergranular porosity, high surface area and low fineness modulus; on the other hand crushed (manufactured) sand has a high rate into thin and irregular shapes which influence the workability of concrete. The amount of dune sand varies from (0%, 50% to 100%) by weight of fine aggregates. The results show that the rheological properties favour the use of dune sands; however the mechanical properties support the use of crushed sand. 展开更多
关键词 Self-compacting concrete dune sand crushed sand FLOWABILITY segregation resistance.
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Opportunities of manufacture under global economic crisis: The case of Estonia
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作者 Kaarel Kilvits 《Chinese Business Review》 2009年第9期17-29,共13页
Because of the smallness of Estonia, its main source of economic growth is export, i.e. successful sales in the world market. It is necessary to shift from branches, activities and value chains where it is difficult t... Because of the smallness of Estonia, its main source of economic growth is export, i.e. successful sales in the world market. It is necessary to shift from branches, activities and value chains where it is difficult to increase value added, to more profitable and promising ones. The present economic situation provides for this an exceptionally good chance. All kinds of development, international relocation of production and reallocation of economic power in the world are gathering speed. It is necessary to rapidly find an opportunity in the "declining" market, a profitable niche. Manufacturing entrepreneurs and executive managers have for several years already been complaining of shortage of workforce that hinders them carrying out new business plans, increasing production and exports. Increased supply of workforce dismissed from construction is an opportunity for the forced development of the manufacturing export sector and sharp increase in exports. 展开更多
关键词 MANUFACTURE RESTRUCTURING EXPORT export sector economic crisis
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Marine Environment around Taiwan Coast
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作者 Ho-Shong Hou 《Journal of Civil Engineering and Architecture》 2016年第11期1297-1303,共7页
Coastal erosion is an island-wide problem in Taiwan; about 80% of the island's sandy coastline had suffered from erosion over the past few decades. Historically, with the specific tectonic environment and rapid uplif... Coastal erosion is an island-wide problem in Taiwan; about 80% of the island's sandy coastline had suffered from erosion over the past few decades. Historically, with the specific tectonic environment and rapid uplifting rate, lots of sediment had been yielded and transported to the coastal area that resulted in an advancing shoreline. Taiwan economically moved from a developing country to a developed one; a lot of human intervention had been made along the island coast. These are the major factors on recent coastal erosion. Even actions such as building of stabilization structures may inadvertently increase erosion. Some intervention examples are chosen to address how human-induced change made the profound impact on coastal erosion in Taiwan. All the information serves to provide a better understanding of the coastal processes, and a better response to the erosion problem. 展开更多
关键词 EROSION SEDIMENT protection construction.
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Sedimentary erosive processes and sediment dispersal in Kaoping submarine canyon 被引量:6
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作者 CHIANG ChengShing YU HoShing 《Science China Earth Sciences》 SCIE EI CAS 2011年第2期259-271,共13页
The Kaoping submarine canyon, connected to the Kaoping River in the coastal plain in SW Taiwan, continues the dispersal path of modern Kaoping River sediments, from an active small mountainous drain basin to the recei... The Kaoping submarine canyon, connected to the Kaoping River in the coastal plain in SW Taiwan, continues the dispersal path of modern Kaoping River sediments, from an active small mountainous drain basin to the receiving basin of the South China Sea. Using seismic reflection sections, Chirp sonar profiles, and bathymetric mapping, we reveal characteristic erosive processes responsible for multiple cut-and-fill features, deeply entrenched thalweg, and sediment dispersal that are closely related to turbidity currents in the canyon. The river-canyon connection setting, along with extreme climatic conditions and active tectonism, is favorable for generation of turbidity currents at the canyon head. The upper reach of the Kaoping Canyon is distinguished into three distinct morpho/sedimentary features. The canyon head is characterized by V-shaped axial thalweg erosion. The sinuous segment of the upper reach is dominated by a deeply incised canyon pathway with trough-like morphol- ogy. Relatively small-scaled features of cut-and-fill associated with the dominant incision process are commonly along the canyon floor, resulting in a flat-floored pathway. Sliding and slumping dominated the steep canyon walls, producing and transporting sediments to canyon floor and partially filling up canyon thalweg. The meandering segment is characterized by erosive features where deeply down-cutting occurs in the outer bend of the major sea valley, forming V-shaped entrenched thalweg. The recurrences of turbidity currents have allowed continuous incision of the canyon head and have kept the connec- tion between the canyon head and the river mouth during Holocene highstand of sea level. The upper reach of the Kaoping Canyon is linked to drainage area and maintains as a conduit and/or sink for terrigenous and shallow marine material. Sediment-laden river plume operates in the Kaoping River-Canyon system, with turbidity currents flushing fiver sediments into the canyon head where the canyon thalweg is the most erosive. Presently, the upper reach of the Kaoping Canyon can be considered as a temporal sediment sink. 展开更多
关键词 entrenched thalweg cut-and-fill sediment dispersal active submarine canyon
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Methods and application of using detrital zircons to trace the provenance of loess 被引量:11
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作者 XIE Jing YANG ShiLing DING ZhongLi 《Science China Earth Sciences》 SCIE EI CAS 2012年第11期1837-1846,共10页
The composition of single-grain detrital zircons is an effective provenance indicator of loess,and sheds new light on dust formation and transportation.Here we review the features of detrital zircons and their use as ... The composition of single-grain detrital zircons is an effective provenance indicator of loess,and sheds new light on dust formation and transportation.Here we review the features of detrital zircons and their use as a provenance indicator,including internal structure,trace element,U-Pb age spectrum and Hf isotopic compositions,and present a case study from the Horqin sandy land and its surrounding loess.The loess samples have detrital zircon age peaks in range of 2600-2300,2100-1600,and 600-100 Ma,of which the 2600-2300 Ma zircon grains mainly have positive Hf(t) values(3.4-8.7),the 2100-1600 Ma zircon grains mainly have negative Hf(t) values(10.1-6.8),and the 600-100 Ma zircon grains have a variable Hf(t) values ranging from 21 to 15.9.The detrital zircon signatures of the loess are similar to the Horqin sandy land,but clearly different from the Chinese Loess Plateau and central-western deserts,implying that the loess is transported mainly from the Horqin sandy land in the Last Glacial period.Comparing these with neighboring tectonic units,we found that zircon populations at 2600-2300,2100-1600,and 600-100 Ma with negative Hf(t) values may come from the northeast North China Craton(NCC),and those at 600-100 Ma with positive Hf(t) values may come from the east Central Asian Orogenic Belt(CAOB).It is estimated that the two sources contribute equally to the Horqin sandy land and the surrounding loess. 展开更多
关键词 loess provenance detrital zircon U-Pb age Hf isotope Horqin sandy land
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