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2019年全国高考英语模拟试题 预览
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作者 刘艺玲 胡新 +4 位作者 杨娟 谢期繁 储俊 陈光伟 李毅 《广东教育:高中版》 2019年第4期47-53,共7页
第二部分阅读理解(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项。AA visitor’s guide to bike hire in AmsterdamMany of the must-see spots in Amsterdam can ... 第二部分阅读理解(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项。AA visitor’s guide to bike hire in AmsterdamMany of the must-see spots in Amsterdam can be seen on aone -day bike tour.Some of the city’s major bike rental shops include: Yellow Bike Yellow Bike has two locations in Amsterdam- Nieuwezijds Kolk 29 and Nieuwe Nieuwstraat 16. Theyare only a 3 - minutewalk from Central Station. The company’s trademark bright yellow bikes make renting from Yellow Bike great for beginners. Bike rental costs €12 for 24 hours and €20 for 48 hours. 展开更多
关键词 英语模拟试题 全国高考 YELLOW YELLOW 阅读理解 ONLY from for
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Changes in freezing and thawing indices over the source region of the Yellow River from 1980 to 2014 预览
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作者 Rui Wang Qingke Zhu Hao Ma 《林业研究:英文版》 CAS CSCD 2019年第1期257-268,共12页
Freezing and thawing indices are not only of great significance for permafrost research but also are important indicators of the effects of climate change.However,to date,research on ground-surface freezing and thawin... Freezing and thawing indices are not only of great significance for permafrost research but also are important indicators of the effects of climate change.However,to date,research on ground-surface freezing and thawing indices and their relationship with air indices is limited.Based on daily air and ground-surface temperatures collected from 11 meteorological stations in the source region of the Yellow River,the freezing and thawing indices were calculated,and their spatial distribution and trends were analyzed.The air-freezing index(AFI),air-thawing index(ATI),ground surface-freezing index(GFI),ground surface-thawing index(GTI),air thawing-freezing index ratio(Na)and surface ground thawing-freezing index ratio(Ng)were 1554.64,1153.93,1.55,2484.85,850.57℃-days and 3.44,respectively.Altitude affected the spatial distribution of the freezing and thawing indices.As the altitude increased,the freezing indices gradually increased,and the thawing indices and thawing-freezing index ratio decreased.From 1980 to 2014,the AFI and GFI decreased at rates of 8.61 and 11.06℃-days a^-1,the ATI and GTI increased at 9.65 and 14.53℃-days a^-1,and Na and Ng significantly increased at 0.21 and 0.79 decade^-1.Changes in the freezing and thawing indices were associated with increases in the air and ground-surface temperatures.The rates of change of the ground surface freezing and thawing indices were faster than the air ones because the rate of increase of the groundsurface temperature was faster than that of the air and the difference between the ground surface and air increased.The change point of the time series of freezing and thawing indices occurred in 2000–2001.After 2000–2001,the AFI and GFI were lower than before the change point,and the changing trend was lower.The ATI,GTI,Na and Ng during 2001–2014 were higher,with faster rates than before.In addition,the annual thawing indices composed a greater proportion of the mean annual air temperature and mean annual ground surface temperature than the annual freezing ind 展开更多
关键词 CLIMATE change FREEZING and thawing indices PERMAFROST The source region of the YELLOW RIVER
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你我风采秀
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作者 杨沛霖 顾铭瑜(指导) +5 位作者 闫旭 蓝杰(指导) 於靖 戴大恩(指导) 赵辰阳 许家红(指导) 《英语角》 2019年第14期52-55,共4页
最近,秋天姐姐收到了很多小朋友的来稿,这些作文都写得非常棒,但是仍然有些不足之处。一起来看看怎么修改吧!Four Seasons There are four seasons in a year. They're spring, summer, autumn and winter. Spring is warm. I can s... 最近,秋天姐姐收到了很多小朋友的来稿,这些作文都写得非常棒,但是仍然有些不足之处。一起来看看怎么修改吧!Four Seasons There are four seasons in a year. They're spring, summer, autumn and winter. Spring is warm. I can see green trees, yellow birds and red flowers in the garden. How beautiful! I can ride a bike in spring. 展开更多
关键词 BEAUTIFUL YELLOW There green CAN 小朋友 SEE RED
Color, Culture and Communication 预览
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作者 刘响慧 《海外英语》 2019年第8期230-232,共3页
The warm yellow symbolizes China, and cool blue the West. Based on the different geographical and psychological significances, there exists cultural disparity in behavioral patterns between these two color cultures, y... The warm yellow symbolizes China, and cool blue the West. Based on the different geographical and psychological significances, there exists cultural disparity in behavioral patterns between these two color cultures, yet their fusion can lead the world culture to a new stage—green culture, just as the mixing of yellow and blue in equal proportions produces peaceful and harmonious green. To the fatigued people, green culture is refreshment. Yellow Culture, Blue Culture and Green Culture will coexist in the world—these are the future cultures for the world. 展开更多
关键词 YELLOW CULTURE BLUE CULTURE Green CULTURE FUSION COMMUNICATION
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Development and Application of an in Situ Penetrator for Rapid Strength Testing of Submarine Sediment 预览
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作者 ZHANG Minsheng WANG Zhenhao +2 位作者 WANG Xiuhai WEN Mingzheng HONG Bo 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第2期328-338,共11页
In marine engineering,the strength of a submarine sediment is an indispensable parameter for assessment of construction.In this study,a free-fall cone penetrator named IPen was developed to realize a rapid and efficie... In marine engineering,the strength of a submarine sediment is an indispensable parameter for assessment of construction.In this study,a free-fall cone penetrator named IPen was developed to realize a rapid and efficient measurement of sediment strength.The equipment is characterized by modular design and self-contained data acquisition.It is equipped with an acceleration sensor,a water pressure sensor,and a piezocone penetration test(CPTu)probe.It is designed to be released from near seabed surface with a releaser and then fall freely to provide a higher penetration velocity.Its maximum working depth is approximately 2500m and maximum penetration depth is approximately 3 m.To derive the correlation between penetration resistance and sediment strength,a calibrator was devised to determine the penetration-rate factor.In addition,the factor applicable to in situ test points was determined in laboratory experiments.In June 2016,the IPen was tested in situ in the South Yellow Sea,China,during a shared voyage funded by the National Science Foundation.Meanwhile,undisturbed column samples were collected for laboratory tests.Based on the in situ test results,it was demonstrated that the IPen could accurately record the working states of various sensors during the freely falling course.IPen test results reliably reflected the sediment strength at all the testing points when compared with laboratory calibration tests,in situ vane tests and penetration tests,laboratory penetration tests,and unconsolidated and undrained triaxial compression tests. 展开更多
关键词 SUBMARINE SEDIMENT free-fall CONE PENETRATION test SEDIMENT strength the Yellow Sea penetration-rate factor
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Concentration and Characterization of Colored Dissolved Organic Matter in the Surface Microlayer and Subsurface Water of the Yellow Sea and the East China Sea 预览
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作者 ZHANG Jing ZHAO Junjie +1 位作者 YANG Guipeng LIU Weifeng 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第2期383-393,共11页
The distribution and chemical properties of colored dissolved organic matter(CDOM)in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated.The input of freshwater and biological act... The distribution and chemical properties of colored dissolved organic matter(CDOM)in the Yellow Sea and the East China Sea during December 2011-January 2012 were investigated.The input of freshwater and biological activities had an evident influence on the CDOM levels(characterized by the light absorption coefficient at the wavelength of 355 nm a355)in the study area.The spatial distribution of CDOM levels displayed a gradually decreasing trend from the coastal waters(0.37m^-1)to the open sea(0.18m^-1).The spectral slope ratio(the slope ratio SR defined as S275-295:S350-400)during the cruise was correlated with salinity,and exhibited a large variation from inshore(average of 2.515)to offshore sites(average of 5.327)compared with the distribution of a355.The values of SR were related to CDOM molecular weight(MW).The a355,SR,and chlorophyll a in 37 samples collected from the surface microlayer were significantly correlated with those in the corresponding subsurface water samples,implying a strong exchange action between the microlayer and bulk water.The a355 and SR of CDOM exhibited significant microlayer enrichment,with mean enrichment factors(EFs)of 1.72 and 1.62,respectively. 展开更多
关键词 COLORED dissolved organic matter(CDOM) absorption coefficient SPECTRAL SLOPE ratio Yellow SEA East China SEA
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Two-thousand years of debates and practices of Yellow River training strategies 预览
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作者 Zhaoyin Wang Cheng Liu 《国际泥沙研究:英文版》 SCIE 2019年第1期73-83,共11页
Throughout the history of China,the Yellow River has been associated with flood disasters and changes in the course of its lower reaches because of sedimentation.From 602 B.C.to 1949 the river experienced 1593 levee b... Throughout the history of China,the Yellow River has been associated with flood disasters and changes in the course of its lower reaches because of sedimentation.From 602 B.C.to 1949 the river experienced 1593 levee bursts,flooding vast areas,and claiming millions of human lives.The river shifted its main course by avulsion 26 times with the apex around Zhengzhou,resulting in devastating calamities and numerous old channels.Training of the Yellow River has a history of more than 3000 yr.Levee construction has been the major strategy for flood control.Two extremely different strategies has been proposed and practiced in the past 2000 yr,i.e.the“wide river and depositing sediment”strategy and the“narrow river and scouring sediment”strategy.This paper analyzes the levee breaches and flood disasters in the past 2000 yr and compares the results of the two extremely different strategies.The“narrow river and scouring sediment”strategy has only short term effects on levee breach control and flood mitigation.The“wide river and depositing sediment”strategy can essentially mitigate flood disasters and reduce levee breaches for a long term period of time.The“wide river and depositing sediment”strategy has been used and no levee breach has occurred in the past 67 yr,which has been the only periods of more than 50 yr with no levee breaches in the history of the Yellow River since 700 A.D.Modern flood and sedimentation management methods have also been introduced,and the strategy of applying the“widen the river and enhance the levees”approach for the upper and lower reaches management is proposed. 展开更多
关键词 Yellow RIVER LEVEE breaches AVULSION Wide RIVER and depositing SEDIMENT STRATEGY Narrow RIVER and SCOURING SEDIMENT STRATEGY
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Effects of Rice-Fish Co-culture on Oxygen Consumption in Intensive Aquaculture Pond 预览
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作者 LI Fengbo SUN Zhiping +6 位作者 QI Hangying ZHOU Xiyue XU Chunchun WU Dianxin FANG Fuping FENG Jinfei ZHANG Ning 《水稻科学:英文版》 CSCD 2019年第1期50-59,共10页
Rice-fish co-culture has gained increasing attention to remediate the negative environmental impacts induced by intensive aquaculture.However,the effect of rice-fish co-culture on oxygen depletion has rarely been inve... Rice-fish co-culture has gained increasing attention to remediate the negative environmental impacts induced by intensive aquaculture.However,the effect of rice-fish co-culture on oxygen depletion has rarely been investigated.We constructed a rice-fish co-culture system in yellow catfish(Pelteobagrus fulvidraco)and freshwater shrimp(Macrobrachium nipponense)ponds using a new high-stalk rice variety,and conducted a field experiment to investigate the effect of rice-fish co-culture on water parameters and oxygen consumption.The results showed that rice-fish co-culture reduced the nutrients(total nitrogen,ammonia-N,total phosphorous and potassium)and the dissolved oxygen content in fish and shrimp ponds.However,they showed similar seasonal change of dissolved oxygen in the water of fish and shrimp ponds.Rice-fish co-culture reduced the total amount of oxygen consumption and optimized the oxygen consumption structure in pond.The respiration rates in water and sediment were significantly reduced by 66.1%and 31.7%in the catfish pond,and 64.4%and 38.7%in the shrimp pond,respectively,by additional rice cultivation.Rice-fish co-culture decreased the proportions of respiration in sediment and water,and increased the proportion of fish respiration.These results suggest that rice-fish co-culture is an efficient way to reduce hypoxia in intensive culture pond. 展开更多
关键词 rice-fish CO-CULTURE oxygen depletion RESPIRATION POND aquaculture yellow CATFISH freshwater shrimp
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Zhu Xianmo -- The Man Who Harnessed the Power of China’s Mother River 预览
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作者 DANG XIAOFEI 《今日中国:英文版》 2019年第5期48-49,共2页
THE Yellow River is the second longest river in China and called the cradle of Chinese civilization. With a drainage area totaling 750,000 square kilometers, it runs 5,464 kilometers through nine provinces and autonom... THE Yellow River is the second longest river in China and called the cradle of Chinese civilization. With a drainage area totaling 750,000 square kilometers, it runs 5,464 kilometers through nine provinces and autonomous regions before emptying into the Bohai Sea. 展开更多
关键词 China’s MOTHER RIVER YELLOW RIVER
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Comparative Efficacies of Next-Generation Insecticides Against Yellow Stem Borer and Their Effects on Natural Enemies in Rice Ecosystem 预览
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作者 Muhammad Matiar RAHAMAN Michael Joseph STOUT 《水稻科学:英文版》 CSCD 2019年第3期157-166,共10页
The efficacies of some next-generation insecticides against the rice yellow stem borer (YSB), Scirpophaga incertulas (Walk.), and their compatibilities with natural enemies were investigated during 2014 and 2015. Thre... The efficacies of some next-generation insecticides against the rice yellow stem borer (YSB), Scirpophaga incertulas (Walk.), and their compatibilities with natural enemies were investigated during 2014 and 2015. Three newer insecticides, chlorantraniliprole 0.4% G, dinotefuran 20% SG, and methoxyfenozide 24% SC, and two commonly used insecticides, carbufuran 5 G and quinalphos 25 EC, were evaluated in the field for their efficacies against YSB and their non-target effects on natural enemies. Application of chlorantraniliprole 0.4% G at 10.96 kg/hm2 resulted in the greatest reduction in YSB infestation (deadhearts and whiteheads) and greatest increase of yield compared to the untreated control plots, followed by methoxyfenozide 24% SC at 0.41 L/hm2, dinotefuran 20% SG at 0.15 kg/hm2, carbufuran 5 G at 10.96 kg/hm2, and quinalphos 25 EC at 1.50 L/hm2. All the insecticides reduced the numbers of predators viz., lady bird beetles, wolf spiders, carabid beetles, earwigs, green mirid bugs, and damselflies. Numbers of adults of the egg parasitoids Trichogramma sp., Telenomus sp. and Tetrastichus sp. were significantly reduced in insecticide-treated plots compared to untreated control plots. In all field trials, the harmful effects of the five insecticides were in the following rank order (least harmful to most harmful): chlorantraniliprole 0.4% G, carbufuran 5 G, dinotefuran 20% SG, methoxyfenozide 24% SC, and quinalphos 25 EC. On the basis of reduction in YSB infestation, increase in grain yield, and compatibility with natural enemies, chlorantraniliprole 0.4% G was proved to be the best of all the insecticides for YSB management system, although the study suggested minimizing its retail price for enhancement of cost effectiveness in farmers’ fields. 展开更多
关键词 INSECTICIDE yellow stem BORER natural ENEMY CHLORANTRANILIPROLE RICE yield
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谈无铅焊锡回流焊后锡面发黄 预览
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作者 刘浩 范银星 《印制电路信息》 2019年第2期55-58,共4页
热风整平焊锡是在PCB表面形成一层既抗铜氧化,又可提供良好的可焊性的涂覆层。随着家电产品类终端客户对产品焊接可靠性严格的要求,外观的严格标准也渐渐纳入整个产品的质量需求。往往许多热风整平焊锡产品在经过高温后,比如一次回流焊... 热风整平焊锡是在PCB表面形成一层既抗铜氧化,又可提供良好的可焊性的涂覆层。随着家电产品类终端客户对产品焊接可靠性严格的要求,外观的严格标准也渐渐纳入整个产品的质量需求。往往许多热风整平焊锡产品在经过高温后,比如一次回流焊而发生锡面的发黄,在空气中放置一段时间后,发黄更加严重或发紫。本文主要讨论锡面发黄的关键因子,并提出一些参考解决方案。 展开更多
关键词 锡/铜/镍 再流焊 锡面 发黄 金属合金层
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Breeding of XX Females(XX♀),YY Physiological Females(YY♀),YY Super-males(YY♂)of Pure-line Yellow Catfish(Pelteobagrus fulvidraco Richardson) 预览
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作者 Qiankai TAN Zhifa TANG +3 位作者 Zhixue TANG Xiuli CHEN Xiaolong WU Tonghui LU 《农业生物技术:英文版》 CAS 2019年第1期1-4,9共5页
Mature wild-type yellow catfish(Pelteobagrus fulvidraco Richardson)individuals with excellent traits have been screened from the Yangtze River as broodstock to establish the germplasm bank of pure-line yellow catfish ... Mature wild-type yellow catfish(Pelteobagrus fulvidraco Richardson)individuals with excellent traits have been screened from the Yangtze River as broodstock to establish the germplasm bank of pure-line yellow catfish by artificial gynogenesis technique and hormonal sex reversal method.Based on pure lines of yellow catfish,super-males and physiological females of yellow catfish were selected by GMT technique,hormonal sex reversal method and test-crossing to establish the germplasm bank of YY physiological females(YY♀).The propagation system of male yellow catfish(XY♂)was established based on the combination of super-males(YY♂)and pure-line female(XX♀)for large-scale production of pure-line yellow catfish males,which effectively overcome the disadvantages in the production of common fingerlings and male fingerlings using low-grade fish with slow growth and small size at the bottom of the fish grader as broodfish,such as progeny germplasm degeneration,loss of growth vigor and reduction of breeding benefits.The technical route of breeding pure-line YY physiological females(YY♀)and YY super-males(YY♂)laid the foundation for large-scale production of environmentally friendly yellow catfish males with pure germplasm and strong stress resistance,and provided an efficient,stable,healthy,environmentally friendly,energy-saving and income-increasing approach for sustainable development of yellow catfish breeding industry. 展开更多
关键词 Yellow catfish(Pelteobagrus FULVIDRACO Richardson) Pure line selection XX females(XX♀) YY PHYSIOLOGICAL females(YY♀) YY super-males(YY♂)
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Epidemiological, prevention and control updates of yellow fever outbreak in Brazil
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作者 Marli do Carmo Cupertino Rebeca Garcia +3 位作者 Andréia Patrícia Gomes Sérgio Oliveira de Paula Nicholas Mayers Rodrigo Siqueira-Batista 《亚太热带医药杂志:英文版》 SCIE CAS 2019年第2期49-59,共11页
Yellow fever is an acute viral disease endemic to tropical countries, like Brazil, where, since the 1940 s, has no significant documented outbreaks similar to that observed between 2016/2018(2 045 confirmed cases and ... Yellow fever is an acute viral disease endemic to tropical countries, like Brazil, where, since the 1940 s, has no significant documented outbreaks similar to that observed between 2016/2018(2 045 confirmed cases and 677 deaths;caused by the sylvatic form).The principal manipulating factors inciting this change were absence of appropriate vaccination campaigns and increased urbanization & population growth in forest areas, with prevalence of the virus in the species inhabiting of these areas.The 2016/2018 outbreaks exhibited incidence in areas with historically low or no yellow fever virus activity, triggering a surge in recorded deaths-mainly in the Southeastern states of Brazil.The Brazilian government aggressively responded, reforming the countries’ prophylactic measures, including vaccine implementation-as of March, 2018, switching from the former double dose regimen of the vaccine, to a single dose protocol, deemed as adequate.Moreover, some states appropriated the fractionated dosage(1/5 of the standard dose), in foresight of potential vaccine shortages.To prevent the uprising of new sylvatic yellow fever cases in Brazil, it’s obligatory the development of effective combative plans, including adaptation of prophylactic measures individually(use of repellents, protective clothing etc.), applicable vaccination campaigns in every endemic region, to raise awareness to locals and visitors alike.Notwithstanding these preventative strategies, the persistence of cases and the recent outbreaks in Brazil, highlight the possible ineffectiveness of combative measures.Based on these considerations, the objective of this review was to raise more awareness of the epidemiological impact of the disease in Brazil. 展开更多
关键词 INFECTIOUS disease Epidemiology Arboviruses Yellow FEVER AEDES aegypti
Properties of Alkali-activated Yellow River Sediment-slag Composite Material
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作者 李高年 WANG Baomin 刘慧 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第1期114-121,共8页
In order to consume the Yellow River sediment as much as possible and improve the longterm stability of the Yellow River, Yellow River sediment was utilized as the main raw material to produce a composite material. Ca... In order to consume the Yellow River sediment as much as possible and improve the longterm stability of the Yellow River, Yellow River sediment was utilized as the main raw material to produce a composite material. Ca(OH)2 was used as alkali-activator to activate the active SiO2 and Al2O3 compositions in Yellow River sediment. 10 wt% slag was added into the mixture to further improve the strength of the composites. The effect of activity rate of the Yellow River sediment and dosage of Ca(OH) 2 on the compressive strength of the Yellow River sediment-slag composite material at different curing ages was researched. XRD, SEM/EDS, light microscope and FTIR were used to further explore the products and the microstructure of the composite material. Results showed that the active ratio of sediment had a great influence on the compressive strength of specimen. In addition, the compressive strength of specimen increased with the increase of Ca(OH)2dosage and curing age. When the dosage of Ca(OH)2 was more than 5 wt% as well as the curing age reached 90 days, the compressive strength of the composite material could meet the engineering requirement. In the alkali-activated process, the main product was hydrated calcium silicate(C-S-H) gel, which filled up the gaps among the sediment particles and decreased the porosity of the specimen. Moreover, the CaCO3 produced by the carbonization of the C-S-H gel and excess Ca(OH)2 also played a role on the strength. 展开更多
关键词 Yellow River sediment SLAG COMPRESSIVE strength hydrated calcium silicate(C-S-H) gel microstructure
Role of permafrost in resilience of social-ecological system and its spatio-temporal dynamics in the source regions of Yangtze and Yellow Rivers
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作者 FANG Yi-ping ZHU Fu-biao +2 位作者 YI Shu-hua QIU Xiao-ping DING Yong-jian 《山地科学学报:英文版》 SCIE CSCD 2019年第1期179-194,共16页
Permafrost is one of the key components of terrestrial ecosystem in cold regions.In the context of climate change,few studies have investigated resilience of social ecological system(SER)from the perspective of permaf... Permafrost is one of the key components of terrestrial ecosystem in cold regions.In the context of climate change,few studies have investigated resilience of social ecological system(SER)from the perspective of permafrost that restricts the hydrothermal condition of alpine grassland ecosystem.In this paper,based on the structural dynamics,we developed the numerical model for the SER in the permafrost regions of the source of Yangtze and Yellow Rivers,analyzed the spatial-temporal characteristics and sensitivity of the SER,and estimated the effect of permafrost change on the SER.The results indicate that:1)the SER has an increasing trend,especially after 1997,which is the joint effect of precipitation,temperature,NPP and ecological conservation projects;2)the SER shows the spatial feature of high in southeast and low in northwest,which is consistent with the variation trends of high southeast and low northwest for the precipitation,temperature and NPP,and low southeast and high northwest for the altitude;3)the high sensitive regions of SER to the permafrost change have gradually transited from the island distribution to zonal and planar distribution since 1980,moreover,the sensitive degree has gradually reduced;relatively,the sensitivity has high value in the north and south,and low value in the south and east;4)the thickness of permafrost active layer shows a highly negative correlation with the SER.The contribution rate of permafrost change to the SER is-4.3%,that is,once the thickness of permafrost active layer increases 1 unit,the SER would decrease 0.04 units. 展开更多
关键词 RESILIENCE of social ECOLOGICAL system PERMAFROST PERMAFROST active layer thickness Structural dynamic equation Source REGIONS of YANGTZE and Yellow RIVERS
Observed characteristics of tidal currents and mean flow in the northern Yellow Sea 预览
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作者 BI Congcong BAO Xianwen +4 位作者 DING Yang ZHANG Cong WANG Yu SHEN Biao WAN Kai 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第2期461-473,共13页
Several bottom-mounted Acoustic Doppler Current Profiler (ADCP) moorings were deployed in the northern Yellow Sea (NYS) during the four seasons of 2006–2007 and also the summertime of 2009. A synthesis analysis on th... Several bottom-mounted Acoustic Doppler Current Profiler (ADCP) moorings were deployed in the northern Yellow Sea (NYS) during the four seasons of 2006–2007 and also the summertime of 2009. A synthesis analysis on the time-continuous records was performed to examine the characteristics and variations of tidal currents and mean flow over the observation period at these stations. Tidal currents accounted for ~75% of the total kinetic energy, with the absolute dominance of M2 constituent. Visible vertical variations of tidal flow were found on all sites, featured by the decrease of amplitude, increase of rotation rate as well as a decreasing trend of the phase for M2 component with depth. A notable exception was in the central NYS, where the maximum tidal currents occurred in the upper or middle layers (~20–40 m) instead of near the surface (<10 m). The observed mean flow was relatively weak, smaller than 15 cm/s. Velocity on the northern end of Yellow Sea Trough (YST) was characterized by low magnitude and an obvious layered structure vertically. In the Bohai Strait (BS) and the northern slope area, the currents weakened and the flow direction presented a major trend to deflect counterclockwise with depth in most observations. Summertime cyclonic circulation around the Yellow Sea Cold Water Mass (YSCWM), its intensification on the frontal zone and the Yellow Sea Warm Current (YSWC) for the winter season were all evident by our direct current measurements. However, the details of water exchange through the BS appeared partly diff erent from the traditionally-accepted pattern. The vertical diff erences of tidal and mean flow were larger in summer than that in winter, implying the influence of thermal structure to the local currents. Aff ected by the water stratification, mean flow usually reached its maximum near the thermocline in spring and summer, while showing a nearly uniform vertical distribution during winter. 展开更多
关键词 NORTHERN YELLOW Sea moored current measurements TIDAL CURRENTS mean flow thermal structure
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Dynamic Changes in the Wetland Landscape Pattern of the Yellow River Delta from 1976 to 2016 Based on Satellite Data 预览
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作者 CONG Pifu CHEN Kexin +1 位作者 QU Limei HAN Jianbo 《中国地理科学:英文版》 SCIE CSCD 2019年第3期372-381,共10页
The Yellow River Delta wetland is the youngest wetland ecosystem in China’s warm temperate zone. To better understand how its landscape pattern has changed over time and the underlying factors responsible, this study... The Yellow River Delta wetland is the youngest wetland ecosystem in China’s warm temperate zone. To better understand how its landscape pattern has changed over time and the underlying factors responsible, this study analyzed the dynamic changes of wetlands using five Landsat series of images, namely MSS(Mulri Spectral Scanner), TM(Thematic Mapper), and OLI(Operational Land Imager) sensors in 1976, 1986, 1996, 2006, and 2016. Object-oriented classification and the combination of spatial and spectral features and both the Normalized Difference Vegetation Index(NDVI) and Normalized Difference Water Index(NDWI), as well as brightness characteristic indices, were used to classify the images in eCognition software. Landscape pattern changes in the Yellow River Delta over the past 40 years were then delineated using transition matrix and landscape index methods. Results show that: 1) from1976 to 2016, the total area of wetlands in the study area decreased from 2594.76 to 2491.79 km~2, while that of natural wetlands decreased by 954.03 km~2 whereas human-made wetlands increased by 851.06 km~2. 2) The transformation of natural wetlands was extensive: 31.34% of those covered by Suaeda heteropteras were transformed into reservoirs and ponds, and 24.71% with Phragmites australis coverage were transformed into dry farmland. Some human-made wetlands were transformed into non-wetlands types: 1.55% of reservoirs and ponds became construction land, and likewise 21.27% were transformed into dry farmland. 3) From 1976 to 2016, as the intensity of human activities increased, the number of landscape types in the study area continuously increased. Patches were scattered and more fragmented. The whole landscape became more complex. In short, over the past 40 years, the wetlands of the Yellow River Delta have been degraded, with the area of natural wetlands substantially reduced. Human activities were the dominant forces driving these changes in the Yellow River Delta. 展开更多
关键词 LANDSCAPE pattern OBJECT-ORIENTED classification LANDSAT WETLANDS YELLOW River Delta
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Physical-biogeochemical interactions and potential effects on phytoplankton and Ulva prolifera in the coastal waters off Qingdao(Yellow Sea,China) 预览
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作者 Qinsheng Wei Baodong Wang +6 位作者 Qingzhen Yao Zhigang Yu Mingzhu Fu Junchuan Sun Bochao Xu Linping Xie Ming Xin 《海洋学报:英文版》 SCIE CAS CSCD 2019年第2期11-23,共13页
In recent years,the spectacular massive green tide of Ulva prolifera has become a recurrent phenomenon appearing every summer in the coastal waters off Qingdao(Yellow Sea,China),attracting the attention of scientists ... In recent years,the spectacular massive green tide of Ulva prolifera has become a recurrent phenomenon appearing every summer in the coastal waters off Qingdao(Yellow Sea,China),attracting the attention of scientists and local government.Based on multidisciplinary data collected during summer and winter,this study focuses on the hydrological characteristics and regional biogeochemical processes in coastal waters off Qingdao.The results show that the boundary of the Yellow Sea Cold Water Mass(YSCWM)can reach the Qingdao coastal region in summer and is locally raised to the upper layers to form coastal upwelling beyond tidal mixing and favorable wind.The regional summer upwelling off the Qingdao coast effectively enriches the nutrient concentrations in the upper water column and thus promotes growth of phytoplankton but reduces the dissolved oxygen(DO)concentration and pH value in the bottom.The regional summer upwelling off Qingdao coast may facilitate the growth and regional blooming of the U.prolifera that migrate to this region with the southerly wind.Additionally,the effects of the front on the aggregation of U.prolifera may be significant.In winter,the Yellow Sea Warm Current(YSWC)extends and spreads along the offshore region off the Subei Shoal towards the Qingdao coastal sea.This tongue-shaped warm water meets the cold coastal water off Qingdao,which leads to the formation of a physical front.As a consequence,remarkable fronts of nutrient and chlorophyll a(Chl a)also form between the shoreward warm water and the cold coastal water.This study increases the understanding of the interactions between the regional physical,chemical,and biological processes off the Qingdao coast. 展开更多
关键词 BIOGEOCHEMICAL process UPWELLING front ULVA PROLIFERA Qingdao coast southern Yellow Sea
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Seasonal size composition and abundance distribution of Euphausia pacifica in relation to environmental factors in the southern Yellow Sea 预览
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作者 Tao Zuo Hui Liu 《海洋学报:英文版》 SCIE CAS CSCD 2019年第2期70-77,共8页
The seasonal size structure and spatial abundance distributions of Euphausia pacifica populations were investigated in the central part of southern Yellow Sea from August 2009 to May 2010.The abundance and biomass of ... The seasonal size structure and spatial abundance distributions of Euphausia pacifica populations were investigated in the central part of southern Yellow Sea from August 2009 to May 2010.The abundance and biomass of E.pacifica were higher in spring and summer,and lower in autumn and winter.The mean abundance and biomass(calculated by carbon)were 74.94 ind./m3 and 8.23 mg/m3,respectively.Females with total length(TL)ranging between 10 and 19 mm in summer had a substantial contribution to the population biomass,whereas larvae of TL of 3–7 mm in spring were the main contributor to the population abundance.The sex ratio(female:male)showed a female bias in four seasons.Its value peaked in summer,and then decreased in autumn,spring,and winter successively.Cohort analysis revealed that the length-frequency distribution of E.pacifica could be characterized as one group with large animals(mean TL>12 mm)accompanied by one or two subgroups of small individuals(mean TL<7 mm).Regarding the spatial distribution,juveniles and adults of E.pacifica tend to concentrate in relatively deep water with low temperature(~11°C)and high salinity(>32),whereas its larvae showed more abundance in inshore water with rich chlorophyll a,low salinity(<32),and warm temperature(>11°C),especially in summer and autumn.Associations changed seasonally between stage-specific abundance and environmental factors. 展开更多
关键词 spatial DISTRIBUTION size composition BIOMASS Euphausia pacifica YELLOW Sea
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Properties of coarse particles in suspended particulate matter of the North Yellow Sea during summer 预览
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作者 ZHANG Kainan WANG Zhenyan +1 位作者 LI Wenjian YAN Jun 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第1期79-92,共14页
Fine particles in seawater commonly form large porous aggregates.Aggregate density and settling velocity determine the behavior of this suspended particulate matter(SPM)within the water column.However,few studies of a... Fine particles in seawater commonly form large porous aggregates.Aggregate density and settling velocity determine the behavior of this suspended particulate matter(SPM)within the water column.However,few studies of aggregate particles over a continental shelf have been undertaken.In our case study,properties of aggregate particles,including size and composition,over the continental shelf of the North Yellow Sea were investigated.During a scientifi c cruise in July 2016,in situ eff ective particle size distributions of SPM at 10 stations were measured,while temperature and turbidity measurements and samples of water were obtained from surface,middle,and bottom layers.Dispersed and inorganic particle size distributions were determined in the laboratory.The in situ SPM was divided into(1)small particles(<32μm),(2)medium particles(32–256μm)and(3)large particles( >256μm).Large particles and medium particles dominated the total volume concentrations(VCs)of in situ SPM.After dispersion,the VCs of medium particles decreased to low values(<0.1μL/L).The VCs of large particles in the surface and middle layers also decreased markedly,although they had higher peak values(0.1–1μL/L).This suggests that almost all in situ medium particles and some large particles were aggregated,while other large particles were single particles.Correlation analysis showed that primary particles<32μm infl uenced the formation of these aggregates.Microscopic examination revealed that these aggregates consisted of both organic and inorganic fi ne particles,while large particles were mucus-bound organic aggregates or individual plankton.The vertical distribution of coarser particles was clearly related to water stratifi cation.Generally,medium aggregate particles were dominant in SPM of the bottom layer.A thermocline blocked resuspension of fi ne material into upper layers,yielding low VCs of medium-sized aggregate particles in the surface layer.Abundant large biogenic particles were present in both surface and middle layers. 展开更多
关键词 suspended PARTICULATE matter(SPM) coarse particles aggregates North Yellow Sea laser in SITU SCATTERING and transmissometery(LISST)
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