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一种针对背景变化的移动物体压缩量子关联成像方法
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作者 徐晓赫 刘娇 赵生妹 《南京邮电大学学报(自然科学版)》 北大核心 2016年第2期111-117,共7页
提出了一种针对背景变化的移动物体压缩量子关联成像方法,可实现移动物体的追踪。将移动物体每个时刻的图像作为量子关联成像的物体,相邻时刻两幅图像的量子关联成像符合测量差值为测量值,参考光路空间光调制器上的二维随机分布作测量矩... 提出了一种针对背景变化的移动物体压缩量子关联成像方法,可实现移动物体的追踪。将移动物体每个时刻的图像作为量子关联成像的物体,相邻时刻两幅图像的量子关联成像符合测量差值为测量值,参考光路空间光调制器上的二维随机分布作测量矩阵,通过最小化增广拉格朗日函数和交替方向全变差算法(TVAL3)压缩感知获得移动物体相邻时刻关联成像差值图像。在此基础上,对差值图像进行"与"操作,得到移动物体各个时刻的位置和形状信息。数值实验的结果表明,在采样率低至0.075时,该方法能有效地获得移动物体的动态变化信息。该方法利用关联成像保证了不可达环境下对移动物体的追踪;利用压缩感知技术降低了重构差值图像时所需的测量次数;通过差值处理避免了背景变化对移动物体检测的影响。为移动物体的跟踪研究提供了一种新方向。 展开更多
关键词 量子关联成像 背景 移动物体识别 压缩感知 增广最小差重建算法
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小学数学复习题组设计要注重“三化” 被引量:1
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作者 郁燕红 《数学教学通讯》 2018年第28期38-39,共2页
复习课是小学数学教学中的重要课型,复习题是引导学生进行数学复习的有效载体之一。教师在设计复习题时不能局限于单一化的模式,要通过"串珠成链"的策略进行复习题组的设计。基于此背景,本文对小学数学层次化、变式化、生活... 复习课是小学数学教学中的重要课型,复习题是引导学生进行数学复习的有效载体之一。教师在设计复习题时不能局限于单一化的模式,要通过"串珠成链"的策略进行复习题组的设计。基于此背景,本文对小学数学层次化、变式化、生活化复习题组的设计策略进行了探究,希望能够达到一定的借鉴意义。 展开更多
关键词 复习题组 层次 变式化 生活
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高中化学教学中问题情境的设计 被引量:2
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作者 陈军 《中学理科园地》 2018年第1期31-32,34,共3页
在教学中,问题情境设计的具体要求为:课题导入的 问题情境能有效地激发学生的学习兴趣;探究性学习中的问 题情境有利于启发学生分析与探究;解题训练中的问题情境 有利于培养学生的思维辨析能力;课题延伸拓展中的问题情 境具有“诱导”... 在教学中,问题情境设计的具体要求为:课题导入的 问题情境能有效地激发学生的学习兴趣;探究性学习中的问 题情境有利于启发学生分析与探究;解题训练中的问题情境 有利于培养学生的思维辨析能力;课题延伸拓展中的问题情 境具有“诱导”学生主动学及如何学的作用或功能. 展开更多
关键词 问题情境 兴趣 启发 变式化 诱导
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初中课堂微观化教学模型变式的理性架构
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作者 邵文鸿 李政淼 《中国教师》 2023年第8期59-62,76,共5页
为回应微观化教学模型的“认知窄化”“学科差异”与“教师主体缺失”等问题,本文从知识的亚类立场、不同的学科立场以及教师的智慧立场构建了微观化教学模型变式的立论逻辑与结构样态,从课堂教学科学开展的视角构建了微观化教学模型变... 为回应微观化教学模型的“认知窄化”“学科差异”与“教师主体缺失”等问题,本文从知识的亚类立场、不同的学科立场以及教师的智慧立场构建了微观化教学模型变式的立论逻辑与结构样态,从课堂教学科学开展的视角构建了微观化教学模型变式生成的保障机制和方法路径。 展开更多
关键词 微观教学模型 教研机制 课堂志
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Geo-information Tupu Analysis of Land Use Change in Haihe River Basin 被引量:2
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作者 朱占永 郭伟志 张海力 《Agricultural Science & Technology》 CAS 2012年第5期1139-1144,共6页
[Objective] This study was to provide basis for the scientific management of land use in Haihe River Basin (HRB) through the quantitative exploration of the land use conversion, changes of intensity and spatial dist... [Objective] This study was to provide basis for the scientific management of land use in Haihe River Basin (HRB) through the quantitative exploration of the land use conversion, changes of intensity and spatial distribution in this region. [Method] With the support of remote sensing technology and geographic information technology, the land use maps of the study area in 40 years (1970-2010) were in- terpreted and plotted. Four kinds of tupu, namely, land use change tupu, process tupu, arising tupu and evolution mode tupu were built through the spatial overlay of the land use maps to analyze the change rules of land use patterns. [Result] The conversion of arable land to construction land was the main characteristics of land use changes in HRB for the 40 years; the area of non-stable region accounted for 35% of the total, indicating that the land use changed remarkably, thus, it was nec- essary to strengthen the scientific land management in HRB; the new conversions to all land use patterns were all the lowest in 1980-1990, indicating that land use changed slowly during this period. [Conclusion] The results indicate that, compared with conventional transfer matrix method, geo-information tupu has obvious advantage in analyzing land use changes that it can demonstrate the spatial distribution of interest region, display the multi-dimensional spatial information. 展开更多
关键词 Haihe river basin Tupu analysis Land use change Evolution mode
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The change of Chinese students' cultural patterns and its roots in the process of globalization
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作者 王丽皓 周薇薇 《Sino-US English Teaching》 2011年第2期126-129,共4页
One of the most important characteristics of culture is that it is subject to change. The theory of cultural patterns in intercultural communication is used to study the change of Chinese students' living pattern, co... One of the most important characteristics of culture is that it is subject to change. The theory of cultural patterns in intercultural communication is used to study the change of Chinese students' living pattern, communication pattern and thinking pattern because of globalization. The factors and reasons of both change and the unchanged are analyzed and summarized. 展开更多
关键词 cultural patterns CHANGE Chinese students
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Dynamic of forest landscape in Heilongjiang Province for one century
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作者 王晓春 孙龙 +3 位作者 周晓峰 王天明 李淑娟 国庆喜 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第1期39-45,共7页
With the help of GIS tool of ARC/INFO, ARCVIEW and FRAGSTATS, the map of forest resource distribution of Heilongjiang Province was analyzed in 1896, 1949 and 1981. Using total area, mean patch size, patch density, coe... With the help of GIS tool of ARC/INFO, ARCVIEW and FRAGSTATS, the map of forest resource distribution of Heilongjiang Province was analyzed in 1896, 1949 and 1981. Using total area, mean patch size, patch density, coefficient of patch size variation, mean patch fractal dimension and mean shape index, we studied the change of forest landscape pattern and the change of each patch types in this region. As a result, the total area of forest landscape and mean patch size decreased sharply, the quantity and density of patches increased, the juxtaposition of patches weakened, the shape of patch tended to become regular, and the border of patch simplified. All these showed that the forest landscape of this area tended to fragment gradually, and the fragment of Korean pine forest is the severest. The diversity of whole forest landscape and the evenness of landscape types distribution reduced gradually. Human impact, instead of climate change and forest community succession, is the most important reason for such dramatic changes. 展开更多
关键词 LANDSCAPE PATTERN Climate change DIVERSITY FRAGMENT Heilongjiang Province
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Advantages of the latest Los Alamos Sea-Ice Model(CICE):evaluation of the simulated spatiotemporal variation of Arctic sea ice 被引量:2
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作者 WANG Huazhao ZHANG Lujun +1 位作者 CHU Min HU Siyu 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第2期113-120,共8页
The Los Alamos Sea-Ice Model(CICE)is one of the most popular sea-ice models.All versions of it have been the main sea-ice module coupled to climate system models.Therefore,evaluating their simulation capability is an ... The Los Alamos Sea-Ice Model(CICE)is one of the most popular sea-ice models.All versions of it have been the main sea-ice module coupled to climate system models.Therefore,evaluating their simulation capability is an important step in developing climate system models.Compared with observations and previous versions(CICE4.0 and CICE5.0),the advantages of CICE6.0(the latest version)are analyzed in this paper.It is found that CICE6.0 has the minimum interannual errors,and the seasonal cycle it simulates is the most consistent with observations.CICE4.0 overestimates winter sea-ice and underestimates summer sea-ice severely.Meanwhile,the errors of CICE5.0 in winter are larger than for the other versions.The main attention is paid to the perennial ice and the seasonal ice.The spatial distribution of root-mean-square errors indicates that the simulated errors are distributed in the Atlantic sector and the outer Arctic.Both CICE4.0 and CICE5.0 underestimate the concentration of the perennial ice and overestimate that of the seasonal ice in these areas.Meanwhile,CICE6.0 solves this problem commendably.Moreover,the decadal trends it simulates are comparatively the best,especially in the central Arctic sea.The other versions underestimate the decadal trend of the perennial ice and overestimate that of the seasonal ice.In addition,an index used to objectively describe the difference in the spatial distribution between the simulation and observation shows that CICE6.0 produces the best simulated spatial distribution. 展开更多
关键词 Los Alamos Sea-Ice Model(CICE) spatiotemporal variation perennial ice seasonal ice model evaluation
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Cloud Seedability Study with a Dual-Model System 被引量:1
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作者 JIN Ling LEI Heng-Chi +2 位作者 KONG Fan-You YANG Jie-Fan HU Zhao-Xia 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第4期197-202,共6页
In this research, one-dimensional stratiform a novel dual-model system, cold cloud model (1DSC) coupled to Weather Research and Forecast (WRF) model (WRF-1DSC for short), was employed to investigate the effects ... In this research, one-dimensional stratiform a novel dual-model system, cold cloud model (1DSC) coupled to Weather Research and Forecast (WRF) model (WRF-1DSC for short), was employed to investigate the effects of cloud seeding by silver iodide (AgI) on rain enhancement. Driven by changing environmental conditions extracted from the WRF model, WRF-1DSC could be used to assess the cloud seeding effects quantitatively. The employment of WRF- 1DSC, in place of a one-dimen- sional two-moment cloud seeding model applied to a three-dimensional mesoscale cloud-resolving model, was found to result in massive reduction of computational resources. Numerical experiments with WRF-1DSC were conducted for a real stratiform precipitation event ob- served on 4-5 July 2004, in Northeast China. A good agreement between the observed and modeled cloud system ensured the ability of WRF-1DSC to simulate the observed precipitation process efficiently. Sensitivity tests were performed with different seeding times, locations, and amounts. Experimental results showed that the optimum seeding effect (defined as the percentage of rain enhancement or rain enhancement rate) could be achieved through proper seeding at locations of maximum cloud water content when the updraft was strong. The optimum seeding effect was found to increase by 5.61% when the cloud was seeded at 5.5 km above ground level around 2300 UTC 4 July 2004, with the maximum AgI mixing ratio (As) equaling 15 ng kg-1. On the other hand, for an overseeded cloud, a significant reduction occurred in the accumulated precipitation (-12.42%) as Xs reached 100 ng kg^-1. This study demonstrates the potential of WRF- 1DSC in determining the optimal AgI seeding strategy in practical operations of precipitation enhancement. 展开更多
关键词 dual-model system AGI cloud seeding WRF clmld model
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Robustness-tracking control based on sliding mode and H_∞ theory for linear servo system 被引量:1
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作者 田艳丰 郭庆鼎 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第2期213-217,共5页
A robustness-tracking control scheme based on combining H_∞ robust control and sliding mode control is proposed for a direct drive AC permanent-magnet linear motor servo system to solve the conflict between tracking ... A robustness-tracking control scheme based on combining H_∞ robust control and sliding mode control is proposed for a direct drive AC permanent-magnet linear motor servo system to solve the conflict between tracking and robustness of the linear servo system. The sliding mode tracking controller is designed to ensure the system has a fast tracking characteristic to the command, and the H_∞ robustness controller suppresses the disturbances well within the close loop(including the load and the end effect force of linear motor etc.) and effectively minimizes the chattering of sliding mode control which influences the steady state performance of the system. Simulation results show that this control scheme enhances the track-command-ability and the robustness of the linear servo system, and in addition, it has a strong robustness to parameter variations and resistance disturbances. 展开更多
关键词 permanent-magnet linear synchronous motor sliding mode control H_∞ robust control DIRECT-DRIVE end-effect
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Climate Change in China Congruent with the Linear Trends of the Annular Modes 被引量:4
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作者 ZHOU Tian-Jun LI Jian 《Atmospheric and Oceanic Science Letters》 2008年第1期1-7,共7页
The authors exploit the remarkable connection between the Chinese climate trends and the annular modes by partitioning the trends into components linearly congruent with and linearly independent of the annular modes. ... The authors exploit the remarkable connection between the Chinese climate trends and the annular modes by partitioning the trends into components linearly congruent with and linearly independent of the annular modes. Results show that the winter hemisphere annular mode has closer connection to Chinese climate than the summer one, e.g., the wetting JJA (June-July-August) rainfall trend along the Yangtze River valley and the associated temperature trends are significantly linearly congruent with the trend of the southern annular mode, while the JFM (January-February-March) climate trends are closely linked to the northern annular mode. The seasonal differences of a meridional wave-train-like chain across the equatorial Pacific associated with the annular modes are responsible for the seasonal-dependent connections to Chinese climate. 展开更多
关键词 Chinese climate TREND annular modes
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Effect of temperature on batch elastase production by Bacillus sp. EL31410 被引量:5
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作者 何国庆 徐莹 +2 位作者 陈启和 阮晖 李景军 《Journal of Zhejiang University Science》 EI CSCD 2004年第12期1583-1589,共7页
The production of elastase by Bacillus sp. EL31410 at various temperatures was investigated. In order to study the effect of temperature on elastase fermentation, different cultivation temperatures, ranging from 39 ℃... The production of elastase by Bacillus sp. EL31410 at various temperatures was investigated. In order to study the effect of temperature on elastase fermentation, different cultivation temperatures, ranging from 39 ℃ to 28 ℃, were evaluated in shake flask. The result indicated that 37 ℃ was best for cell growth at earlier stage; while maximum elastase activity was obtained when the cells were cultivated at 30 ℃. This result was verified by batch fermentation in 5-L bio-reactor under 37 ℃ and 30 ℃ temperature, respectively. The specific cell growth rate at 37 ℃ was higher than that at 30 ℃ during earlier stage of cultivation. The maximum value [5.5 U/(h-g DCW)] of elastase formation rate occurred at 24 h at 30 ℃ compared to 4.6 U/(h-g DCW) at 30 h at 37 ℃. Based on these results, two-stage temperature shift strategy and oscillatory temperature cultivation mode were evaluated in the next study. When compared to single temperature of 37 ℃ or 30 ℃, both two-stage temperature shift strategy and oscillatory temperature strategy improved biomass but did not yield the same result as expected for elastase production. The maximum biomass (both 8.6 g/L) was achieved at 30 h at 37 ℃, but at 42 h using two-stage temperature cultivation strategy. The highest elastase production (652 U/ml) was observed at 30 ℃ in batch process. It was concluded that cultivation at constant temperature of 30 ℃ was appropriate for elastase production by Bacillus sp. EL31410. 展开更多
关键词 Bacillus sp. EL31410 ELASTASE TEMPERATURE Batch fermentation Temperature-shift strategy
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China cardiovascular diseases report 2015: a summary 被引量:50
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作者 Wei-Wei CHEN Run-Lin GAO +10 位作者 Li-Sheng LIU Man-Lu ZHU Wen WANG Yong-Jun WANG Zhao-Su WU Hui-Jun LI Dong-Feng GU Yue-Jin YANG Zhe ZHENG Li-Xin JIANG Sheng-Shou HU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2017年第1期1-10,共10页
1 Introduction Major and profound changes have taken place in China over the past 30 years. An epidemic of cardiovascular diseases (CVD) in China is emerging as a result of lifestyle changes, urbanization, and the ... 1 Introduction Major and profound changes have taken place in China over the past 30 years. An epidemic of cardiovascular diseases (CVD) in China is emerging as a result of lifestyle changes, urbanization, and the accelerated process of aging. The incidence of CVD is continuously increasing and will remain an upward trend in the next decade. Since 2005, 展开更多
关键词 Atrial fibrillation Cardiovascular diseases HYPERTENSION Risk factors STATISTICS STROKE
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Climate Change over China in the 21st Century as Simulated by BCC_CSM1.1-RegCM4.0 被引量:79
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作者 GAO Xue-Jie WANG Mei-Li Filippo GIORGI 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第5期381-386,共6页
Driven by the global model,Beijing Climate Center Climate System Model version 1.1(BCC_CSM1.1),climate change over China in the 21st century is simulated by a regional climate model(RegCM4.0)under the new emission sce... Driven by the global model,Beijing Climate Center Climate System Model version 1.1(BCC_CSM1.1),climate change over China in the 21st century is simulated by a regional climate model(RegCM4.0)under the new emission scenarios of the Representative Concentration Pathways—RCP4.5 and RCP8.5.This is based on a period of transient simulations from 1950 to2099,with a grid spacing of 50 km.The present paper focuses on the annual mean temperature and precipitation in China over this period,with emphasis on their future changes.Validation of model performance reveals marked improvement of the RegCM4.0 model in reproducing present day temperature and precipitation relative to the driving BCC_CSM1.1 model.Significant warming is simulated by both BCC_CSM1.1 and RegCM4.0,however,spatial distribution and magnitude differ between the simulations.The high emission scenario RCP8.5 results in greater warming compared to RCP4.5.The two models project different precipitation changes,characterized by a general increase in the BCC_CSM1.1,and broader areas with decrease in the RegCM4.0 simulations. 展开更多
关键词 climate change regional climate model RCP scenarios China
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How Well does BCC_CSM1.1 Reproduce the 20th Century Climate Change over China? 被引量:31
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作者 XIN Xiao-Ge WU Tong-Wen +3 位作者 LI Jiang-Long WANG Zai-Zhi LI Wei-Ping WU Fang-Hua 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第1期21-26,共6页
The historical simulation of phase five of the Coupled Model Intercomparison Project (CMIP5) ex- periments performed by the Beijing Climate Center cli- mate system model (BCC_CSM1.1) is evaluated regard- ing the t... The historical simulation of phase five of the Coupled Model Intercomparison Project (CMIP5) ex- periments performed by the Beijing Climate Center cli- mate system model (BCC_CSM1.1) is evaluated regard- ing the time evolutions of the global and China mean sur- face air temperature (SAT) and surface climate change over China in recent decades. BCC CSM1.1 has better capability at reproducing the time evolutions of the global and China mean SAT than BCC_CSM1.0. By the year 2005, the BCC_CSM1.1 model simulates a warming am- plitude of approximately I℃ in China over the 1961- 1990 mean, which is consistent with observation. The distributions of the warming trend over China in the four seasons during 1958-2004 are basically reproduced by BCC CSM1.1, with the warmest occurring in winter. Al- though the cooling signal of Southwest China in spring is partly reproduced by BCC_CSM1.1, the cooling trend over central eastern China in summer is omitted by the model. For the precipitation change, BCC_CSM1.1 has good performance in spring, with drought in Southeast China. After removing the linear trend, the interannual correlation map between the model and the observation shows that the model has better capability at reproducing the summer SAT over China and spring precipitation over Southeast China. 展开更多
关键词 BCC_CSM climate system model simula- tion climate change
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Computation of the Simplest Normal Forms for Resonant Double Hopf Bifurcations System Based on Lie Transform 被引量:2
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作者 张琪昌 何学军 郝淑英 《Transactions of Tianjin University》 EI CAS 2006年第3期180-185,共6页
The simplest normal form of resonant double Hopf bifurcation was studied based on Lie operator. The coefficients of the simplest normal forms of resonant double Hopf bifurcation and the nonlinear transformations in te... The simplest normal form of resonant double Hopf bifurcation was studied based on Lie operator. The coefficients of the simplest normal forms of resonant double Hopf bifurcation and the nonlinear transformations in terms of the original system coefficients were given explicitly. The nonlinear transformations were used for reducing the lower- and higher-order normal forms, and the rank of system matrix was used to determine the coefficient of normal form which could be reduced. These make the gained normal form simpler than the traditional one. A general program was compiled with Mathematica. This program can compute the simplest normal form of resonant double Hopf bifurcation and the non-resonant form up to the 7th order. 展开更多
关键词 nonlinear systems normal form bifurcation mathematical transformations Lie operator computer program
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In vivo and in situ detection of colorectal cancer using Fourier transform infrared spectroscopy 被引量:3
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作者 Qing-BoLi ZhiXu +9 位作者 Neng-WeiZhang LiZhang FanWang Li-MinYang Jian-ShengWang SuZhou Yuan-FuZhang Xiao-SiZhou Jing-SenShi Jin-GuangWu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第3期327-330,共4页
AIM: Real-time and rapid Identification of the malignant tissue can be performed during or before surgical operation. Here we aimed to detect in vivo and in situ colorectal cancer by using Fourier transform infrared (... AIM: Real-time and rapid Identification of the malignant tissue can be performed during or before surgical operation. Here we aimed to detect in vivo and in situ colorectal cancer by using Fourier transform infrared (FTIR) spectroscopy and fiber-optic technology. METHODS: A total of five patients with large intestine cancer were detected in vivo and in situ. Of them, three cases of colon cancer and one case of cecum cancer were detected intraoperatively and in vivo by using a FTIR spectrometer during surgical operation, and one case of rectum cancer was explored non-invasively and in vivo before the surgical operation. Normal and malignant colorectal tissues were detected in vivo and in situ using FTIR spectroscopy on the basis of fundamental studies. RESULTS: There were significant differences between FTIR spectra of normal and malignant colorectal tissues detected in vivo and in situ. Experimental results revealed that the spectral characteristics of normal and malignant tissues found in vivo and in situ were similar to those obtained from in vitro measurement in our previous fundamental research. CONCLUSION: FTIR fiber-optic attenuated total reflectance (ATR) spectroscopy can identify in situ and in vivo colorectal cancer. FTIR spectroscopie method with fiber optics is a non-invasive, rapid, accurate and in vivo cancer detection technique in clinical diagnosis. 展开更多
关键词 Colorectal cancer Fourier transform infrared spectroscopy
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Tidal effects on diel variations of picoplankton and viruses in the Changjiang estuary 被引量:1
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作者 李云 李道季 +2 位作者 方涛 张利华 王延明 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第3期435-442,共8页
Spatial distributions and seasonal variations of picoplankton (i.e. Synechococcus spp., Prochlorococcus spp., picoeukaryotes and heterotrophic bacteria) and viruses in the Changjiang estuary have been reported in the ... Spatial distributions and seasonal variations of picoplankton (i.e. Synechococcus spp., Prochlorococcus spp., picoeukaryotes and heterotrophic bacteria) and viruses in the Changjiang estuary have been reported in the past. However, short-term variations (e.g. at a tidal timescale) of these organisms and their regulating factors remain unclear. We determined the time-series of fluctuations of picoplankton and viruses with tide simultaneously in flow cytometry in the Changjiang estuary during a cruise in June 2006, in which a tidal model based rectangle equation was applied. The results indicate that high cell abundances of picoplankton and viruses occurred during flood tide and low cell abundances during ebb tide. The period of the surface cell abundance variations was about 13 h, suggesting the surface cell abundances in the Changjiang estuary were largely regulated by tide. However, cell abundances in middle and bottom waters varied in different periods due to influences of tidal induced physical forces such as resuspension and stratification. Therefore, tidal action is an important factor for the diel variations of picoplankton and viruses in the Changjiang estuary. 展开更多
关键词 PICOPLANKTON viruses tidal effect Changjiang estuary
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Water transports through the four main straits around the South China Sea 被引量:4
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作者 王庆业 崔红 +1 位作者 张书文 胡敦欣 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第2期229-236,共8页
A quasi-global high-resolution HYbrid Coordinate Ocean Model (HYCOM) is used to investigate seasonal variations of water transports through the four main straits in the South China Sea. The results show that the annua... A quasi-global high-resolution HYbrid Coordinate Ocean Model (HYCOM) is used to investigate seasonal variations of water transports through the four main straits in the South China Sea. The results show that the annual transports through the four straits Luzon Strait, Taiwan Strait, Sunda Shelf and Mindoro Strait are -4.5, 2.3, 0.5 and 1.7 Sv (1 Sv=106 m3s-1), respectively. The Mindoro Strait has an important outflow that accounts for over one third of the total inflow through the Luzon Strait. Furthermore, it indicates that there are strong seasonal variations of water transport in the four straits. The water transport through the Luzon Strait (Taiwan Strait, Sunda Shelf, Mindoro Strait) has a maximum value of -7.6 Sv in December (3.1 Sv in July, 2.1S v in January, 4.5Sv in November), a minimum value of -2.1 Sv in June (1.5 Sv in October, -1.0 Sv in June, -0.2 Sv in May), respectively. 展开更多
关键词 CIRCULATION volume transport numerical model South China Sea
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Droplet Pattern Formation and Translation in New Microfluidic Flow- Focusing Devices
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作者 徐华国 梁好均 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第6期679-684,I0003,I0004,共8页
We conducted experiments on specially designed microfluidic chips that generate droplets through a microfluidic ow-focusing approach. The fluid flow in the microfluidic channel produced a shear flow field at low Reyno... We conducted experiments on specially designed microfluidic chips that generate droplets through a microfluidic ow-focusing approach. The fluid flow in the microfluidic channel produced a shear flow field at low Reynolds numbers. The droplets in the microfluidic system exhibited special droplet pattern formations similar to periodic crystal-like lattices because of the competition between shear forces and surface tension. By adjusting the flow rate ratio of the water (droplet phase) to oil (continuous phase) phases and changing the outlet channel widths, the droplets formed monolayer dispersion to double-layer formation to monolayer squeezing when the outlet channel widths were 250 or 300 μm. We also obtained droplets with monolayer dispersion, three-layer arrangements, double-layer squeezing, and monolayer squeezing when the outlet channel width was 350 μm. The outlet channel width was increased to 400 μm, and four-layer arrangements were observed. We also studied the translation of droplet formation, which resulted in a detailed strategy to control drop size and droplet pattern formation for emulsi cation in microfluidic devices. We expect that our strategy can provide theoretical guidance to synthesize dispersion or polydisperse colloid particles. 展开更多
关键词 Microfluidic flow-focusing device Droplet pattern formation TRANSITION
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