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Sensitivity study of coastal plumes

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Acta Oceanologica Sinica 1999年第2期18卷 147-166页

作者： Wang Jia Mo Ruxi Gao Zhenhui Yin Zhongbin and Chen Mingjian 1. international arctic {2. center-Frontier, university of alaska fairbanks, Fairbanki, alaska 99775, usa. Email: jwang @ chukchi. iare. uaf. edu 2. Guangxi Marine Monitoring Forecast Cen Intl. arctic Res. center-Frontier University of Alaska Fairbanks Fairbanks AK 99775 United States Guangxi Mar. Monitoring Forecast C. South China Sea Branch State Oceanic Administration Beihai 536000 China Marine Monitoring Division North Sea Branch State Oceanic Administration Qingdao 266033 China Off. of Marine Monitoring Technology Hi-Tech R. and D. Program of China Beijing 100081 China State Oceanic Administration Beijing 100860 China

A three-dimensional numerical model of the coastal plume in an ideal basin for the western Gulf of Maine of usa, based on the observations, was configured to examine the dynamical properties under the spring riverine, tidal, and wind forcing. The purpose of this paper is to reveal possible effects of different factors on the coastal plume. The control run with a sloping bottom mimicking the western Gulf of Maine reproduced a southward advection speed of 14 km/d, consistent with the observed speed of 13.3 km/d. The plume evolutions due to the two typical wind forcing, upwelling favourable (wind from north) and downwelling favourable (wind from south). were simulated to explain the observations during the spring of 1993. A systematic sensitivity study was also conducted on the following themes: model parameters. dynamic processes, and topography effect.

关键词： Coastal plume three-dimensional model Gulf of Maine

Tribological applications of biomaterials: an overview

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Science China Mathematics 2001年第S1期44卷 297-306页

作者： Bing Shi Hong Liang Department of Mechanical Engineering, university of alaska fairbanks fairbanks, ak,{2. Univ alaska fairbanks Dept Mech Engn Fairbanks AK 99775 USA

Tribological research is the study of lubrication, friction, and wear. Tribology of biomate-rials is to study how the materials work and fail. This will help us to produce better *** plays a very important role in improving the design and making successful biomaterialsfor medical purposes. Joints of human body, such as hip, knee, jaw, dental parts etc., all need toconsider the wear and lubrication problem. In this paper, we give a general introduction of bioma-terial research in tribological applications. Materials, the synthetic characterization, and their failureare introduced.

关键词： Biomaterials Tribological Materials

THE INSTABILITY OF NON-HYDROSTATIC STRATIFIED FLOWS

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Journal of Hydrodynamics 1999年第4期11卷 39-44页

作者： Ren Jiou chun, Shen I fan, Tao Ming de Depatment of Mechanics and Engineering Science, Fudan university, Shanghai 2.0433, P.R.ChinaWang Jia international {2. research center, university of alaska fairbanks, P.O. 7572.0, fairbanks, ak 99775 72.0

In this study we concentrate on the perturbations of pressure and density caused by thermohaline and expect to discuss the instability of the primitive equations of stratified flows for non hydrostatic internal waves. Traditionally, under the assumption of hydrostatic pressure, the Lagrangian derivative of the vertical velocity is ignored and the vertical velocity can be computed by integrating the continuity equation. In the process of dense water formation, on the basis of a quasi non hydrostatic perturbation pressure, the time derivative of the vertical velocity and the Coriolis term in the vertical momentum equation are included. With non hydrostatic approach we obtain three typical forms of the instability with Synge′s theorem, Miles′ theorem and Howard′s semicircle theorem. With the non hydrostatic Synge′s theorem, the Coriolis acceleration appears while stratification exists. The non hydrostatic conclusions derived by Miles′ theorem and Howard′s semicircle theorem are the same as their hydrostatic counterparts.

关键词： non hydrostatic stratified instability

A preliminary study on vegetation-erosion dynamics and its applications

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Science China Earth Sciences 2005年第5期48卷 689-700页

作者： WANG Zhaoyin 1,2., WANG Guangqian 1 , LI Changzhi 1 & WANG Feixin 1 1. Department of Hydraulic Engineering, Tsinghua university, Beijing 100084, China 2. international {2. and Training center on Erosion and Sedimentation, Beijing 100084, China Department of Hydraulic Engineering Tsinghua University Beijing China international research and Training {2. on Erosion and Sedimentation Beijing China

Vegetation-erosion dynamics is a new interdisciplinary science, studying the laws of evolution of watershed vegetation under the action of various ecological stresses. Introducing a qualitative expression of ecological stresses in this paper, the present authors establish the cou- pled differential equations for the vegetation-erosion process and derive a theoretical solution. The model is applied to the Anjiagou watershed on the Loess Pateau and the Xiaojiang water- shed and its sub-watersheds on the Yunnan Plateau. The calculated results agree well with the vegetation development processes. Abstracted from the differential equations the so-called vegetation-erosion chart is worked out, with which we can predict the development trend of vegetation under no human stresses. It is demonstrated that the erosion control is important for vegetation development and reforestation must be a long-term strategy. On the Yunnan Plateau with relatively high precipitation and temperature, vegetation can be greatly improved if erosion is controlled. On the dry and cold Loess Pateau suffering from high rate of soil erosion, however, vegetation can effectively control erosion but erosion reduction exhibits low effectiveness on vegetation development. Vegetation in the area is not stable and management is always needed to maintain the vegetation.

关键词： vegetation-erosion dynamics, human activities, coupled differential equations, erosion control, vigor ofvegetation.

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

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Science China Earth Sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3 & WANG Huijun2.1. Nansen-Zhu international research {2., Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 10002., China 2. Department of Atmospheric Science, Yunnan university, Kunming 650091, China 3. Graduate university of the Chinese Academy of Sciences, Beijing 100049, China Nansen-Zhu international research {2. Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Department of Atmospheric Science Yunnan University Kunming China Graduate university of the Chinese Academy of Sciences Beijing China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials international 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1, GONG Qin~1 and YE Datian~2.*(1. Department of Biomedical Engineering, Tsinghua university, Beijing 100084, China 2. research {2. of Biomedical Engineering, Graduate School at Shenzhen, Tsinghua university, Shenzhen 518055, China) Department of Biomedical Engineering Tsinghua University Beijing 100084 China research center of Biomedical Engineering Graduate School Shenzhen Tsinghua University Shenzhen 518055 China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

Integrating MODFLOW and GIS technologies for assessing impacts of irrigation management and groundwater use in the Hetao Irrigation District,Yellow River basin

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Science China(Technological Sciences) 2009年第11期52卷 3257-3263页

作者： XU Xu1,2. HUANG GuanHua1,2.& QU ZhongYi3 1 center for Agriculture Water research, China Agricultural {2., Beijing 100083, China 2.Chinese-Israeli international center for research and Training in Agriculture, China Agricultural {2., Beijing 100083, China 3 Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural {2., Hohhot 010018, China center for Agriculture Water research China Agricultural University Beijing China Chinese-Israeli international center for {2. and Training in Agriculture China Agricultural University Beijing China Water Conservancy and Civil Engineering College Inner Mongolia Agricultural University Hohhot China

Due to severe water scarcity, water resources used in agricultural sector have been reduced markedly in Hetao irrigation district. Application of water-saving practices (WSPs) is required for the sustainable agricultural development. The human activities including WSPs and increase of groundwater abstraction can lower down the groundwater table, which is helpful to the salinity control. Meanwhile, an excessively large groundwater table depth may result in negative impact on crop growth and fragile ecological environment. In this paper, the Jiefangzha irrigation system in Hetao irrigation district was selected as a typical area, a groundwater flow model based on ArcInfo Geographic Information System (GIS) was developed and implemented to quantify the effect of human activities on the groundwater system in this area. The preand post-processing of model data was performed efficiently by using the available GIS tools. The time-variant data in boundary conditions was further edited in Microsoft Excel with programs of Visual Basic for Application (VBA). The model was calibrated and validated with independent data sets. Application of the model indicated that it can well describe the effect of human activities on groundwater dynamics in Jiefangzha irrigation system.

关键词： groundwater flow modeling MODFLOW GIS water-saving practices irrigation district

Genetic analysis of segregation distortion of mating-type factors in Lentinula edodes

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Progress in Natural Science:Materials international 2005年第8期15卷 684-688页

作者： CHENG Shuiming 1,2. LIN Fanxue1, XU Xuefeng1, LI Anzheng1 and LIN Fangcan1*(1. State Key Laboratory of Agricultural Microbiology and Institute of Applied Mycology, Huazhong Agricultural university, Wuhan 430070, China 2. National Engineering research {2. For Wheat, Henan Agricultural university, Zhengzhou 450002. China) State Key Laboratory of Agricultural Microbiology and Institute of Applied Mycology Huazhong Agricultural University Wuhan 430070 China National Engineering research center For Wheat Henan Agricultural University Zhengzhou 450002 China

Analyses of the mating-type ratio of protoplast monokaryons to spores in 2. strains of Lentinula edodes were performed through statistical methods. The results showed that the segregation distortion phenomenon commonly exists in both types of Lentinula edodes, 17 out of the 2. samples did not display the expected 1∶1 ratio of protoplast monokaryons; and among them 8 fruiting strains distorted 1∶1∶1∶1 segregation of spores. The degree of distortion in all tested wild strains was significantly lower than that of cultured strains. In fruiting test of positive-negative parent, predominant spores were those with the mating type identical to dikaryotic parent, indicating that the predominance of nuclei mainly depends on the mating type of dikaryotic parent. Data from di-mon mating test verified that monokaryons with acceptor nuclear type are present exclusively in a large amount after dedikaryotization, suggesting that the specificities among B factors and some other unknown factors in cytoplasm are probably responsible for the phenomenon of skewed segregation.

关键词： Lentinula edodes mating-type factors segregation distortion cytoplasm.

Assessment of groundwater suitability for different activities in Toshka district,south Egypt

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Journal of Groundwater Science and Engineering 2024年第1期12卷 34-48页

作者： Marwa M Aly Shymaa ak Fayad Ahmed MI Abd Elhamid Faculty of Engineering Mataria Helwan UniversityCairo 11718Egypt Division of Engineering International Academy for Engineering and Media Science(IAEMS)6th of October City 15515Egypt Hydraulics research Institute National Water Research CenterMWRICairo 13621Egypt

Globally,groundwater has globally emerged as a crucial freshwater source for domestic,irrigation,and industrial *** evaluation of groundwater quality in the Toshka region is imperative to ensure its suitability for the extensive agricultural and industrial activities underway in this promising,groundwater-dependent development *** is particularly significant as Egypt increasingly relies on groundwater reserves to address freshwater deficits and to implement mega-development projects in barren *** this study,fifty-two samples were collected from the recently drilled wells tapping into the Nubian Sandstone Aquifer(NSA)in the Toshka *** quality was assessed through hydrochemical analysis,Piper diagram,and various indicators such as Na%,SAR,RSC,KR,MH and *** hydrochemical analysis revealed improved groundwater quality characteristics,attributed to continuous recharge from Lake *** Piper diagram categorised most of the water samples as"secondary salinity"water *** all wells proved suitable for irrigation with only two wells unsuitable based on MH values and six wells based on KR *** Total Hardness(TH)values,all samples were classified as"Soft",indicating their suitability for domestic and industrial *** Quality Index(WQI)results concluded that all samples met WHO and FAO guidelines for drinking and irrigation,*** distribution maps,constructed using GIS,facilitate the interpretation of the *** monitoring of quality parameters is essential to detect any deviation from permissible limits.

关键词： Nubian Sandstone Aquifer Water Quality Assessment Hydro-chemical Analysis Irrigation Quality Indicators Domestic Use Water Quality Index