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The Late Miocene‘ovibovin’bovids in Eurasia
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作者 Muhammad ILYAS LI Qiang +1 位作者 SHI Qin-Qin NI Xi-Jun 《古脊椎动物学报(中英文)》 CSCD 北大核心 2024年第4期262-290,共29页
During the Late Miocene,numerous medium to large-sized herbivores,that resemble the living Ovibos in skeletal morphology,dispersed throughout the Holarctic realm and comprised eleven genera:Lantiantragus,Shaanxispira,... During the Late Miocene,numerous medium to large-sized herbivores,that resemble the living Ovibos in skeletal morphology,dispersed throughout the Holarctic realm and comprised eleven genera:Lantiantragus,Shaanxispira,Tsaidamotherium,Criotherium,Mesembriacerus,Hezhengia,Urmiatherium,Parurmiatherium,Plesiaddax,Sinotragus,and Prosinotragus.These genera are primarily found in eastern Asia,in which nine genera are found in northern China,as well as in countries in eastern Europe and western Asia.They are distinguished by unique characteristics,including a perpendicular braincase,specialized horn cores,and a robust basioccipital.Previous studies have often classified these‘ovibovin’bovids as part of the conventional subfamily/tribe Ovibovinae/Ovibovini,along with extant Ovibos.Nevertheless,an increasing number of studies do not support the monophyly of the subfamily/tribe Ovibovinae/Ovibovini,nor is a close relationship likely between these Late Miocene‘ovibovin’bovids and extant Ovibos.Among the eleven genera of‘ovibovin’bovids,Plesiaddax,Hezhengia,and Urmiatherium are often considered to have a very close relationship and conventionally form the tribe Urmiatheriini.However,previous phylogenetic analyses do not support the monophyly of Urmiatheriini.This paper presents a summary of the transmutation of the terms Ovibovidae/Ovibovinae/Ovibovini/Ovibovina,the temporal and spatial distribution of the Late Miocene‘ovibovin’bovids in Eurasia,the principal characteristics of these taxa,and the previous phylogenetic analyses. 展开更多
关键词 EURASIA Late Miocene ‘ovibovin’bovids BOVIDAE temporal and spatial distribution
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Simultaneous Identification of Thermophysical Properties of Semitransparent Media Using a Hybrid Model Based on Artificial Neural Network and Evolutionary Algorithm
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作者 LIU Yang HU Shaochuang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第4期458-475,共18页
A hybrid identification model based on multilayer artificial neural networks(ANNs) and particle swarm optimization(PSO) algorithm is developed to improve the simultaneous identification efficiency of thermal conductiv... A hybrid identification model based on multilayer artificial neural networks(ANNs) and particle swarm optimization(PSO) algorithm is developed to improve the simultaneous identification efficiency of thermal conductivity and effective absorption coefficient of semitransparent materials.For the direct model,the spherical harmonic method and the finite volume method are used to solve the coupled conduction-radiation heat transfer problem in an absorbing,emitting,and non-scattering 2D axisymmetric gray medium in the background of laser flash method.For the identification part,firstly,the temperature field and the incident radiation field in different positions are chosen as observables.Then,a traditional identification model based on PSO algorithm is established.Finally,multilayer ANNs are built to fit and replace the direct model in the traditional identification model to speed up the identification process.The results show that compared with the traditional identification model,the time cost of the hybrid identification model is reduced by about 1 000 times.Besides,the hybrid identification model remains a high level of accuracy even with measurement errors. 展开更多
关键词 semitransparent medium coupled conduction-radiation heat transfer thermophysical properties simultaneous identification multilayer artificial neural networks(ANNs) evolutionary algorithm hybrid identification model
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Interfacial characteristics and microstructural evolution of Sn-6.5Zn solder/Cu substrate joints during aging 被引量:2
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作者 赵国际 盛光敏 +1 位作者 吴莉莉 袁新建 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第8期1954-1960,共7页
The influence of isothermal aging at 150 °C on the microstructural characteristics and microhardness of the Sn-6.5Zn solder/Cu joint was studied. The mechanisms for the formation and evolution of intermetallic co... The influence of isothermal aging at 150 °C on the microstructural characteristics and microhardness of the Sn-6.5Zn solder/Cu joint was studied. The mechanisms for the formation and evolution of intermetallic compound (IMC) at the interface of the Sn-6.5Zn/Cu joint were also analyzed. The results indicate that a continuous layer consisting of CuZn and Cu5Zn8 IMCs is formed in the interface zone. As the aging time prolongs, the thickness of the IMC layer first increases and then decreases, and the continuous and compactable layer is destroyed due to the decomposition of the Cu-Zn IMC layer. A discontinuous layer of Cu6Sn5 IMC is present within the Cu substrate near the decomposed region. The interface becomes rough and evident voids form after aging. The microhardness of the interface increases owing to the application of aging. 展开更多
关键词 Sn-6.5Zn solder interface intermetallic compound AGING evolution
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Effect of heat treatment on microstructure and thermophysical properties of diamond/2024 Al composites 被引量:6
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作者 修子扬 王旭 +2 位作者 M.HUSSAIN 冯超 姜龙涛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3584-3591,共8页
50%diamond particle (5μm) reinforced 2024 aluminum matrix (diamond/2024 Al) composites were prepared by pressure infiltration method. Diamond particles were distributed uniformly without any particle clustering, ... 50%diamond particle (5μm) reinforced 2024 aluminum matrix (diamond/2024 Al) composites were prepared by pressure infiltration method. Diamond particles were distributed uniformly without any particle clustering, and no apparent porosities or significant casting defects were observed in the composites. The diamond-Al interfaces of as-cast and annealed diamond/2024 Al composites were clean, smooth and free from interfacial reaction product. However, a large number of Al2Cu precipitates were found at diamond-Al interface after aging treatment. Moreover, needle-shaped Al2MgCu precipitates in Al matrix were observed after aging treatment. The coefficient of thermal expansion (CTE) of diamond/2024 Al composites was about 8.5×10-6 °C-1 between 20 and 100 °C, which was compatible with that with chip materials. Annealing treatment showed little effect on thermal expansion behavior, and aging treatment could further decrease the CTE of the composites. The thermal conductivity of obtained diamond/2024 Al composites was about 100 W/(m?K), and it was slightly increased after annealing while decreased after aging treatment. 展开更多
关键词 Al matrix composites DIAMOND INTERFACE ANNEALING AGING thermal properties
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Temporal-spatial Distribution Model of Cold Chain Logistics for Vegetables
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作者 陈绍慧 张鹏 +1 位作者 鲁晓翔 李江阔 《Agricultural Science & Technology》 CAS 2012年第5期1115-1118,共4页
[Objective] The aim was to study on temporal-spatial distribution model of cold chain logistics for vegetables. [Method] Broccoli was taken as an example. Detailedly, time-space distribution model of cold chain logist... [Objective] The aim was to study on temporal-spatial distribution model of cold chain logistics for vegetables. [Method] Broccoli was taken as an example. Detailedly, time-space distribution model of cold chain logistics for broccoli was proposed from standpoints of costs and benefits based on changes of time and space, and a comprehensive evaluation was made on timeliness, efficiency, risks, added- value of products and satisfaction of information in cold-chain logistics. [Result] The efficiency of cold chain logistics for vegetable can be greatly improved by temporal- spatial distribution model of cold chain logistics. [Conclusion] Costs and benefits of vegetables in temporal-apstial distribution could be evaluated by the model. 展开更多
关键词 VEGETABLE Cold-chain logistics Temporal-spatial distribution BROCCOLI
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物时
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作者 吴涤 《中学生百科(大语文)》 2017年第3期34-35,共2页
“四季,一个温柔而苦涩的提醒。”静谧拥吻书房,穆斯法塔在黑暗中隐匿。月光光,狰狞的时间皮囊下未藏杀机。
关键词 中国 当代文学 散文 《物时》
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Microstructure evolution of a new directionally solidified Ni-based superalloy after long-term aging at 950 ℃ upto 1 000 h 被引量:3
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作者 黄炎 王磊 +3 位作者 刘杨 付顺明 吴剑涛 燕平 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第10期2199-2204,共6页
The microstructure evolution of a new directionally solidified(DS) Ni-based superalloy used for gas turbine blades after long-term aging at 950 ℃ was investigated.The results show that the γ ' phase becomes more ... The microstructure evolution of a new directionally solidified(DS) Ni-based superalloy used for gas turbine blades after long-term aging at 950 ℃ was investigated.The results show that the γ ' phase becomes more regular in dendritic arm and interdendritic area,while both the mass fraction and the size of γ ' phase increase gradually with increasing aging time.During long-term aging,the MC carbide dissolves on the edge to provide the carbon for the formation of M23C6 carbide by the precipitation of Cr at the grain boundary.The rose-shaped γ '/γ eutectic partly dissolves into γ matrix and the aging promotes it transform into raft-shape γ '.The microstructure is generally stable and no needle-like topologically close-packed phase(TCP) can be found after aging for 1 000 h. 展开更多
关键词 Ni-based superalloy long-term aging microstructures evolution carbides γ phase
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Analysis of Reference Evapotranspiration Change and Its Impact Factors in Australia
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作者 谢今范 曾丽红 +1 位作者 宋开山 张柏 《Agricultural Science & Technology》 CAS 2009年第5期30-33,共4页
[ Objective] To discuss regional response of reference evapotranspiration ( ETo ) to global climate change and its influencing factors. [Method] Penman-Monteith equation was adopted to calculate ET0 in Australia fro... [ Objective] To discuss regional response of reference evapotranspiration ( ETo ) to global climate change and its influencing factors. [Method] Penman-Monteith equation was adopted to calculate ET0 in Australia from 1998 to 2007. Spatiotemporal change characteristics were analyzed by using GIS spatial analysis tools and relationships between ETo and main climate factors were also analyzed. [ Resultsl The results showed that multi-year average ET0 increased from the east and south part to the northwest part and inland, and its distribution was consistent with climate zones. Multi-year average ETo of the whole region was 1 750 mm, obtaining minimum and maximum values in 2000 and 2002 respectively. Regional ETo decreased in the order of summer, spring, autumn and winter; January and December got the highest monthly ET0, while June got the lowest value 79.55 mm. ETo positively correlated with mean temperature and solar radiation, R2 for each were 0.83 and 0.94, while the relationship between ETo and average relative humidity was negative, and precipitation had no significant relationship with ET0. [ Conclusion] This research could provide important reference for crop water requirement study and making irrigation method for Australia. 展开更多
关键词 AUSTRALIA Reference evapotranspiration Penman-Monteith equation Spatiotemporal change
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Sutureless Intestinal Anastomosis with a Novel Device of Magnetic Compression Anastomosis 被引量:19
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作者 Chao Fan Jia Ma Hong-ke Zhang Rui Gao Jian-hui Li Liang Yu Zheng Wu Yi Lv 《Chinese Medical Sciences Journal》 CAS CSCD 2011年第3期182-189,共8页
Objective To explore the feasibility and efficiency of a novel magnetic compression anastomats(MCAs) in intestinal anastomosis.Methods A total of 36 male mongrel canines underwent intestinal anastomosis using traditio... Objective To explore the feasibility and efficiency of a novel magnetic compression anastomats(MCAs) in intestinal anastomosis.Methods A total of 36 male mongrel canines underwent intestinal anastomosis using traditional hand-sewn(n=18) or a novel MCAs(n=18).We compared the anastomosis time,postoperative complications,bursting strength of anastomoses,gross appearance,and pathology between two groups at each time-point of follow-up.Results The mean anastomosis time with MCAs was significantly less than that with hand-sewn(8.50±1.95 vs.31.1±4.32 minutes,P<0.001).The blood stools and intussusceptions occurred in both groups during follow-up period.Only 1 mongrel canine receiving intestinal anastomosis by MCAs experienced anastomotic leakage.The average bursting pressure of anastomoses obtained from mongrel canines undergoing intestinal anastomosis by MCAs was significantly higher than that by traditional hand-sewn at 1 week's follow-up time(P<0.05).Gross appearance of the anastomoses constructed by MCAs was relatively smoother and flatter.Pathological evalution of anastomoses revealed that general inflammation was greater in hand-sewn anastomoses than magnetic anastomosis.Conclusion The magnetic compression anastomat is a safe and effective device of sutureless intestinal anastomosis in canine models. 展开更多
关键词 magnetic compression anastomosis bursting strength foreign body reaction
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Spatial and temporal variation of picoplankton distribution in the Yellow Sea, China 被引量:2
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作者 赵苑 赵丽 +4 位作者 肖天 赵三军 宣基亮 李超伦 宁修仁 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第1期150-161,共12页
Seven surveys were carried out in April, September, October, December 2006 and March, May, August 2007 in the Yellow Sea, China. Variations in the spatial and temporal distribution of Synechococcus, picoeukaryotes and... Seven surveys were carried out in April, September, October, December 2006 and March, May, August 2007 in the Yellow Sea, China. Variations in the spatial and temporal distribution of Synechococcus, picoeukaryotes and heterotrophic bacteria are quantified using flow cytometry. Synechococcus and heterotrophic bacteria are most abundant from late spring to autumn, while picoeukaryotes concentration is high in spring. Synechococcus and heterotrophic bacteria concentrated high in the northwest part of the Yellow Sea in spring and autumn, while picoeukaryotes distributed evenly over the whole study area except for a small frontal zone in the coastal area on the west (in spring) and central Yellow Sea (in autumn). Under mixing conditions, the vertical distribution of the three picoplankton groups showed a well-mixed pattern. Upon a well-established stratification, the maximum abundance of picoplankton occurred above the mixed layer depth (-30 m). Cell sizes of Synechococcus and picoeukaryotes were estimated by converting forward scatter signals (FSC) from cytometry analysis to cell diameter, showing the results of 0.65-0.82 um for Synechococcus and 0.85-1.08 um for picoeukaryotes. The average integrated carbon biomasses ranged 15.26-312.62 mgC/m2 for Synechococcus, 18.54-51.57 mgC/m2 for picoeukaryotes, and 402.63-818.46 mgC/m2 for heterotrophic bacteria. The distribution of Synechococcus and heterotrophic bacteria was temperature dependent, and picoplankton presence was poor in the Yellow Sea Cold Water Mass. 展开更多
关键词 SYNECHOCOCCUS PICOEUKARYOTES heterotrophic bacteria DISTRIBUTION Yellow Sea Cold Water Mass
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Retrieval of Electron Return Time from High-order Harmonics Generated in a Mixture of He and Ne Gases 被引量:1
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作者 金成 周效信 赵松峰 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第4期735-741,共7页
In terms of single-atom induced dipole moment by Lewenstein model, we present the macroscopic high-order harmonic generation from mixed He and Ne gases with different mixture ratios by solving three-dimensional Maxwel... In terms of single-atom induced dipole moment by Lewenstein model, we present the macroscopic high-order harmonic generation from mixed He and Ne gases with different mixture ratios by solving three-dimensional Maxwell's equation of harmonic field. And then we show the validity of mixture formulation by Wagner et al. [Phys. Rev. A 76 (2007) 061403(R)] in macroscopic response level. Finally, using/east squares fitting we retrieve the electron return time of short trajectory by formulation in Kanai et al. [Phys. Rev. Lett. 98 (2007) 153904] when the gas jet is put after the laser focus. 展开更多
关键词 high-order harmonic generation Maxwell's equation Lewenstein model return time
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Activity budget of Rhinopithecus bieti at Tibet:Effects of day length,temperature and food availability 被引量:8
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作者 Zuofu XIANG Sheng HUO Wen XIAO 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第6期650-659,共10页
How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day leng... How animals allocate their time to various activities has significant consequences for their survival because they reflect the different constraints on time-energy balances. Many ecological variables, such as day length, temperature, food availabil- ity, are supposed to effect on activity budgets allocation of temperate primates. To examine the potential influence of these three variables, the activity budgets ofRhinopithecus bieti was studied at Xiaochangdu, Tibet from June 2003 to March 2005. Pearson correlations were utilized to assess potential relationships between activity budget and day length, food availability and temperature, and stepwise multiple regressions to identify the priority of resting and other activities (activities besides feeding, moving and resting). Time spent resting and doing "other activities" is positively related to day length, temperature and food availability. No significant correlations were found between feeding/moving time and any of these variables. This suggests that foraging time (feeding + moving) takes priority over rest and other activities. Day length and foraging time (as independent variables) were related to the time spent in the other two activities besides feeding/moving (as dependent variables). Both time spent resting and in "other activities" were highly significant positive functions of day length, with the latter a highly significant negative function of feeding time and moving time. Resting time may therefore be interpreted as taking priority over "other activities" time. These results provide further evidence of the importance of day length, temperature and food availability to seasonal activity budgets [Current Zoology 56 (6): 650q559, 2010]. 展开更多
关键词 Activity budget Rhinopithecus bieti Day length TEMPERATURE Food availability Activity pattem
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Temporal Changes in Transboundary Air Pollutants in Bottom Sediments of Lakes in East Asia 被引量:1
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作者 Shlntaro Mura Ryosuke Sato +5 位作者 Masaki Hashimoto Akiko Murakami-Kitase Hideo Yamazaki Shusaku Yoshikawa Ju-Yong Kim Kazuo Kamura 《Journal of Environmental Science and Engineering(B)》 2013年第11期629-639,共11页
To clarify temporal changes in the transboundary pollution, we analyzed SCPs (spheroidal carbonaceous particles) in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of an... To clarify temporal changes in the transboundary pollution, we analyzed SCPs (spheroidal carbonaceous particles) in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of anthropogenic atmospheric pollution in bottom sediments. Recently deposited SCPs in air and unmelted snow on Mt. Fuji were also characterized. The concentrarion and characteristics of SCPs reflected the environmental and industrial history of the area. Evidence of transboundary air pollution was observed after the 1980s in Yashagaike and Kotaniike ponds in Japan, which are located on the coast of the Sea of Japan. The concentration suggests that the pollutants originated from continental Asia, particularly after the 1980s. The chemical composition of the SCPs allowed the source of emissions to be identified. Chinese SCPs were found at Yashagaike and Kotaniike ponds in Japan, and at Songiiho and Urimji lakes in Korea. The size distributions showed that small SCPs are transported over long distances. On the summit of Mr. Fuji, SCPs transported by the prevailing westerlies from China were found in addition to SCPs emitted in Japan. 展开更多
关键词 Bottom sediments transboundary air pollution SCPs.
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Scheduling transactions in mobile distributed real-time database systems 被引量:1
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作者 雷向东 赵跃龙 +1 位作者 陈松乔 袁晓莉 《Journal of Central South University of Technology》 EI 2008年第4期545-551,共7页
A DMVOCC-MVDA (distributed multiversion optimistic concurrency control with multiversion dynamic adjustment) protocol was presented to process mobile distributed real-time transaction in mobile broadcast environment... A DMVOCC-MVDA (distributed multiversion optimistic concurrency control with multiversion dynamic adjustment) protocol was presented to process mobile distributed real-time transaction in mobile broadcast environments. At the mobile hosts, all transactions perform local pre-validation. The local pre-validation process is carried out against the committed transactions at the server in the last broadcast cycle. Transactions that survive in local pre-validation must be submitted to the server for local final validation. The new protocol eliminates conflicts between mobile read-only and mobile update transactions, and resolves data conflicts flexibly by using multiversion dynamic adjustment of serialization order to avoid unnecessary restarts of transactions. Mobile read-only transactions can be committed with no-blocking, and respond time of mobile read-only transactions is greatly shortened. The tolerance of mobile transactions of disconnections from the broadcast channel is increased. In global validation mobile distributed transactions have to do check to ensure distributed serializability in all participants. The simulation results show that the new concurrency control protocol proposed offers better performance than other protocols in terms of miss rate, restart rate, commit rate. Under high work load (think time is ls) the miss rate of DMVOCC-MVDA is only 14.6%, is significantly lower than that of other protocols. The restart rate of DMVOCC-MVDA is only 32.3%, showing that DMVOCC-MVDA can effectively reduce the restart rate of mobile transactions. And the commit rate of DMVOCC-MVDA is up to 61.2%, which is obviously higher than that of other protocols. 展开更多
关键词 mobile distributed real-time database systems muliversion optimistic concurrency control multiversion dynamic adjustment pre-validation multiversion data broadcast
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A Real-Time Photo-Realistic Rendering Algorithm of Ocean Color Based on Bio-Optical Model 被引量:4
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作者 MA Chunyong XU Shu +2 位作者 WANG Hongsong TIAN Fenglin CHEN Ge 《Journal of Ocean University of China》 SCIE CAS 2016年第6期996-1006,共11页
Abstract A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton,... Abstract A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton, colored dissolved organic material (CDOM), inorganic suspended particle, etc., which have different contributionsto absorption and scattering of light. We decompose the emergent light of the ocean surface into the reflected light from the sun and the sky, and the subsurface scattering light. We estab- lish an ocean surface transmission model based on ocean bidirectional reflectance distribution function (BRDF) and the Fresnel law, and this model's outputs would be the incident light parameters of subsurface scattering. Using ocean subsurface scattering algorithm combined with bio-optical model, we compute the scattering light emergent radiation in different directions. Then, we blend the re- flection of sunlight and sky light to implement the real-time ocean color rendering in graphics processing unit (GPU). Finally, we use two kinds of radiance reflectance calculated by Hydrolight radiative transfer model and our algorithm to validate the physical reality of our method, and the results show that our algorithm can achieve real-time highly realistic ocean color scenes. 展开更多
关键词 ocean color BRDF subsurface scattering bio-optical model
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Seasonal changes in the demersal nekton community off the Changjiang River estuary 被引量:1
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作者 姜亚洲 凌建忠 +2 位作者 李建生 杨林林 李圣法 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第2期278-289,共12页
The diversity,community structure and seasonal variation in demersal nekton off the Changjiang(Yangtze)River estuary was evaluated using monthly trawl survey data,collected between December 2008 and November 2009.A to... The diversity,community structure and seasonal variation in demersal nekton off the Changjiang(Yangtze)River estuary was evaluated using monthly trawl survey data,collected between December 2008 and November 2009.A total of 95 species(56 teleosts,11 cephalopods,and 28 decapod crustaceans)from 69 genera,49 families and 15 orders were collected.These species could be classifi ed into six groups on the basis of temporal distribution patterns.The resident crab Ovalipes punctatus dominated the community,both in number and biomass.A clear seasonal succession was observed in the species composition.Cluster analysis revealed three primary seasonal groups corresponding to the samples collected in winter-spring,late spring-summer and late summer-autumn.The highest biomass and lowest diversity were observed in summer,while the lowest biomass and highest diversity in winter.The abundance-biomass comparison curves and community composition suggested that the investigated community was moderately disturbed.The results suggest that reduction in fi shing pressure and in the degree of seasonal hypoxia are essential for sustainable resource management off the Changjiang River estuary. 展开更多
关键词 species diversity community structure seasonal succession summer hypoxia abundancebiomass comparison curves
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EXAMINATION OF SILICATE LIMITATION OF PRIMARY PRODUCTION IN JIAOZHOU BAY, CHINA I. SILICATE BEING A LIMITING FACTOR OF PHYTOPLANKTON PRIMARY PRODUCTION 被引量:31
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作者 杨东方 张经 +2 位作者 吕吉斌 高振会 陈豫 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2002年第3期208-225,共18页
Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou Bay, were analyzed to determine the spatiotemporal variations i... Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou Bay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO - 3 N, NO - 2 N, NH + 4 N, SiO 2- 3 Si, PO 3- 4 P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq.(1) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temperature; that the main factor controlling the primary production is Si; that water temperature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecological niches for C , the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D , the coefficient of water temperature’s effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay, the biogeochemical sediment process of the silicon, the phytoplankton predominant species and the phytoplankton structure. The authors considered silicate a limiting factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and uptake by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrinsic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant nutrient concentrations but low phytoplankton biomass in some waters is reasonably explained in this paper. 展开更多
关键词 PHYTOPLANKTON silicon limiting factor Jiaozhou Bay
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Development of Studies on RNA Interference 被引量:1
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作者 张俐 张雅琼 +5 位作者 佘丽娜 徐文婷 贾阳映 谢世清 孙文丽 梁泉 《Agricultural Science & Technology》 CAS 2012年第9期1838-1842,共5页
RNA interference (RNAi), caused by endogenous or exogenous double- stranded RNA (dsRNA) homologous with target genes, refers to gene silencing widely existing in animals and plants. It was first found in plants, a... RNA interference (RNAi), caused by endogenous or exogenous double- stranded RNA (dsRNA) homologous with target genes, refers to gene silencing widely existing in animals and plants. It was first found in plants, and now it has developed into a kind of biotechnology as well as an important approach in post- genome era. This paper is to summarize the achievements of studies on RNAi tech- nology in basic biology, medicine, pharmacy, botany and other fields. 展开更多
关键词 RNA interference Post-genome Functional genome
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Medium Optimization for Improved Ethanol Production in Very High Gravity Fermentation 被引量:6
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作者 胡纯铿 秦晴 高培培 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第6期1017-1022,共6页
An optimal medium (300 g·L^-1 initial glucose) comprising 6.3 mmol·L^-1 Mg2+, 5.0 mmol·L^-1 Ca2+, 15.0 g·L^-1 peptone and 21.5 g·L^-1 yeast extract was determined by uniform design to impr... An optimal medium (300 g·L^-1 initial glucose) comprising 6.3 mmol·L^-1 Mg2+, 5.0 mmol·L^-1 Ca2+, 15.0 g·L^-1 peptone and 21.5 g·L^-1 yeast extract was determined by uniform design to improve very high gravity (VHG) ethanol fermentation, showing over 30% increase in final ethanol (from 13.1% to 17.1%, by volume), 29% decrease in fermentation time (from 84 to 60 h), 80% increase in biomass formation and 26% increase in glucose utilization. Experiments also revealed physiological aspects linked to the fermentation enhancements. Compared to the control, trehalose in the cells grown in optimal fermentation medium increased 17.9-, 2.8-, 1.9-, 1.8- and 1.9-fold at the fermentation time of 12, 24, 36, 48 and 60 h, respectively. Its sharp rise at the early stage of fermentation when there was a considerable osmotic stress suggested that trehalose played an important role in promoting fermentation. Meanwhile, at the identical five fermentation time, the plasma membrane ATPase activity of the cells grown in optimal medium was 2.3, 1.8, 1.6, 1.5 and 1.3 times that of the control, respectively. Their disparities in enzymatic activity became wider when the glucose levels were dramatically changed for ethanol production, suggesting this enzyme also contributed to the fermentation improvements. Thus, medium optimization for VHG ethanol fermentation was found to trigger the increased yeast trehalose accumulation and plasma membrane ATPase activity. 展开更多
关键词 medium optimization very high gravity fermentation TREHALOSE plasma membrane ATPase
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Impact of light intensity on flowering time and plant quality of Antirrhinum majus L. cultivar Chimes White 被引量:2
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作者 MUNIRMuhammad JAMILMuhammad BALOCHJalal-ud-din KHATTAKKhalidRehman 《Journal of Zhejiang University Science》 CSCD 2004年第4期400-405,共6页
Shades of different light intensities (29%, 43%, 54%,60% or 68%) along with control (no shade) were studied to observe their effects on the flowering time and plant quality. A hyperbolic relationship was observed betw... Shades of different light intensities (29%, 43%, 54%,60% or 68%) along with control (no shade) were studied to observe their effects on the flowering time and plant quality. A hyperbolic relationship was observed between different light intensities under shade,and time to flowering.The total number of flower buds showed a curvilinear relationship with light intensities. Growth parameters related to the plant characteristics such as plant height,leaf area and plant fresh weight were improved under shading treatments at the expense of flowering time and number of flower buds.However,both linear and polynomial models applied assumed that cultivar Chimes White was equally sensitive to light intensity throughout development. 展开更多
关键词 Antirrhinum majus L. SNAPDRAGON Growth and development FLOWERING Light intensity.
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