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Tidally induced upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer

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Science china Earth Sciences 2007年第3期50卷 462-473页

作者： L XinGang1,2,3.4, QIAO FangLi1,2, XIA ChangShui1,2 & YUAN YeLi1,2 1 The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, china 2 Key Laboratory of Marine Science and Numerical Modeling (MASNUM), State Oceanic Administration, Qingdao 266061, china 3.Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, china 4 {3. university of the Chinese Academy of Sciences, beijing 10003., china 1. The First Institute of Oceanography State Oceanic Administration Qingdao 266061 China 2. Key Laboratory of Marine Science and Numerical Modeling (MASNUM) State Oceanic Administration Qingdao 266061 China 3. Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China 4. graduate university of the Chinese Academy of Sciences Beijing 100039 China

MASNUM wave-tide-circulation coupled numerical model (MASNUM coupled model, hereinafter) is de-veloped based on the Princeton Ocean Model (POM). Both POM and MASNUM coupled model are ap-plied in the numerical simulation of the upwelling off Yangtze River estuary and in Zhejiang coastal waters in summer. The upwelling mechanisms are analyzed from the viewpoint of tide, and a new mechanism is proposed. The study suggests that the tidally inducing mechanism of the upwelling in-cludes two dynamic aspects: the barotropic and the baroclinic process. On the one hand, the residual currents induced by barotropic tides converge near the seabed, and upwelling is generated to maintain mass conservation. The climbing of the residual currents along the sea bottom slope also contributes to the upwelling. On the other hand, tidal mixing plays a very important role in inducing the upwelling in the baroclinic sea circumstances. Strong tidal mixing leads to conspicuous front in the coastal waters. The considerable horizontal density gradient across the front elicits a secondary circulation clinging to the tidal front, and the upwelling branch appears near the frontal zone. Numerical experiments are de-signed to determine the importance of tide in inducing the upwelling. The results indicate that tide is a key and dominant inducement of the upwelling. Experiments also show that coupling calculation of the four main tidal constituents (M2, S2, K1, and O1), rather than dealing with the single M2 constituent, im-proves the modeling precision of the barotropic tide-induced upwelling.

关键词： upwelling dynamic mechanism numerical simulation tidal movement tidal mixing front

Rate Adaptation Schemes for Different Service Requirements in the Code Division Multiple Access Environment

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The Journal of china Universities of Posts and Telecommunications 1994年第1期1卷 16-21页

作者： Yang Dacheng (Department of Telecommunications Engineering, beijing university of Posts arid Telecommunications, beijing 100088, P. R.{3.)

the of the important requirements of any candidate architecture for the future personal communication System is the flexibility to support several different service requirements. These services may require different bearer rates or different Ed/N0 requirements. This paper will propose two rate adaptation schemes which could be applied to the Code Division Multiple Access (CDMA) architecture for accepting different service requirements.'.

关键词： CDMA Rate adaptation

The late Paleoproterozoic extension event:aulacogens and dyke Swarms in the North china craton

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Progress in Natural Science:Materials International 2006年第2期16卷 201-208页

作者： HOU Guiting, LI Jianghai, LIU Yulin and QIAN Xianglin (Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking university, beijing 100871, china) [a]Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space Sciences Peking University Beijing China

The extension structures and tectonic implication in the North china Craton ( NCC) are discussed in this paper based on the mafic dyke swarms and geochronology, combining with the geochronology of aulacogens. The late Paleoproterozoic time is the important turning point in the Precambrian evolution of the NCC. The extension system (e.g. aulacogens and dyke swarms) is widespread in the NCC, which marks the carbonization of the NCC with the rigid characteristic similar to the modern plate. The paleostress field modeling suggests that the dyke swarms and aulacogens are arogenic extension marking the start of the supercontinent, not synorogenic and post-orogenic extension. The mafic dyke swarms in the NCC mainly ranged from 1.83.to 1.77 Ga. The extension of the NCC is very limited brittle extension, the average extension ratio is only 0.3.% given by mafic dyke swarms extension calculation, so most of extension in the NCC is contributed by the aulacogens. The mafic dyke swarms are related with the aulacogens in the origin.

关键词： North china craton late Paleoproterozoic aulacogens mafic dyke swarms extension.

喷灌条件下土壤NO_3.--N含量的空间变异性研究

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土壤学报 2004年第6期41卷 991-995页

作者：高鹭胡春胜毛仁钊中国科学院地理科学与资源研究所中国科学院石家庄农业现代化研究所石家庄050021

作物生长所需的养分主要来源于土壤,因而土壤作为作物生长的营养库,其养分的变异必然会引起作物生长的变异.北方旱地土壤氮素形态一般以硝态氮为主,所以开展土壤NO-3.N含量空间变异性研究对于科学合理地制定农田施肥方案,提高氮肥利用率... 详细信息

作物生长所需的养分主要来源于土壤,因而土壤作为作物生长的营养库,其养分的变异必然会引起作物生长的变异.北方旱地土壤氮素形态一般以硝态氮为主,所以开展土壤NO-3.N含量空间变异性研究对于科学合理地制定农田施肥方案,提高氮肥利用率,促进变量施肥技术的发展,实现精确施肥具有重要意义[1～3..灌区田间实际情况表明,在土壤质地相同的区域内,土壤特性(物理、化学及生物性质)在同一时刻,各个空间位置上的量值并不相同[4].喷灌是一种节水效果十分显著,适应性较强的灌水方式,相比传统灌溉其湿润层要浅,对硝态氮的淋洗以及对环境的影响必然也较传统灌溉不同.因此利用地统计学方法,研究喷灌条件下土壤中硝态氮的空间变异性,对NO-3.N的空间监测、寻找土壤空间变异研究与作物生长空间变异研究的最佳切合点以及研究喷灌条件下硝态氮对环境的影响程度具有重要的指导意义.……

关键词：土壤氮素作物生长养分喷灌空间变异性 N含量 NO3.- 形态硝态氮

APPLICATION OF TIME-VARYING VISCOUS GROUT IN GRAVEL-FOUNDATION ANTI-SEEPAGE TREATMENT

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Journal of Hydrodynamics 2011年第3期23卷 391-397页

作者： CHENG Peng-da LI Lu TANG Ju WANG Dao-zeng Shanghai Institute of Applied Mathematics and Mechanics Shanghai university Shanghai 200072 China beijing Wangleihong Foundation Project Co. Ltd Beijing 100071 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai university Shanghai 200072 China

The time-varying viscosity of common grout and the controllable grout are measured with a rotation viscometer in experiments. The time-varying viscosity of grout is analyzed according to the characteristics in the process of anti-seepage treatment for gravel foundation. The principle of effective stress for porous medium is applied to analyzes the fluid-structure coupling in grouting. In the consideration of coupling physical variables, dynamic models of porosity, permeability and viscosity are constructed. The diffusion radius can thus be defined by the foundational porosity. The distribution of holes in field experiments is designed according to the diffusion radius of grout. Then, the permeability test is designed to verify the grout effect. The calculated diffusion radius coincides with experimental results, and the permeability meets the requirements of the project, which is valuable for the anti-seepage treatment in gravel foundation.

关键词： fluid-structure coupling viscosity gravel foundation

Study on the Influence Mechanism of Organizational Culture on the M＆A Effectiveness

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Study on the Influence Mechanism of Organizational Culture o...

Photosynthetic characteristics of dominant tree species and canopy in the broadleaved Korean pine forest of Changbai Mountains

2010 IEEE 2nd Symposium on Web Society

作者： YAO Ziping~(1,2) (Research Center for Contemporary Management of Tsinghua university beijing,china) (School of Management,{3. university,Chinese Academy of Sciences beijing,china) SHI Kan (School of Management,{3. university, Chinese Academy of Sciences beijing,china)

＜正＞This article is to explore the impact mechanism of organizational culture on the M＆A effectiveness,by the survey of 3. senior managers from the acquiring *** findings are:organizational culture difference does not deal significantly with the M＆A effectiveness,but has the negative influence on the executives organizational commitment;organizational culture identification has a positive influence on M＆A effectiveness;most of the senior managers are easy to make the confusion of the culture tolerance and cultural integration involvement.

关键词： organizational culture M&A effectiveness influence mechanism

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Science china Earth Sciences 2006年第S2期49卷 89-98页

作者： WU Jiabing, GUAN Dexin, SUN Xiaomin, ZHANG Mi, SHI Tingting, HAN Shijie & JIN Changjie Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, china graduate university of the Chinese Academy of Sciences,{3., china Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101, china

Based on the light-photosynthesis response measurement at leaf level, combined with over- and under-canopy eddy covariance measurements, research on photosynthetic characteristics of single trees and forest canopy was conducted. The relationship between light intensity and photo-synthetic rates for leaves and canopy can be well fitted by a non-rectangular hyperbola model. Mongolian oak presented a high light compensation point, Lcp (28μmol·m-2·s-1), a light saturation point Lsp (>1800μmol·m-2·s-1), and a maximal net photosynthetic rate Pmax (9.96μmol·m-2·s-1), which suggest that it is a typical heliophilous plant. Mono maple presented the highest apparent quantum efficiencyα(0.066) but the lowest, Lcp (16μmol·m-2·s-1), Lsp (=800μmol·m-2·s-1), and Pmax (4.51μmol·m-2·s-1), which suggest that it is heliophilous plant. Korean pine showed the lowestαvalue but a higher Pmax, which suggest that it is a semi-heliophilous plant. At the canopy level, the values of both or and Pmax approached the upper limit of reported values in temperate forests, while Lcp was within the lower limit. Canopy photosynthetic characteristics were well consistent with those of leaves. Both showed a high ability to photosynthesize. However, environmental stresses, especially high vapor pressure deficits, could significantly reduce the photosynthetic ability of leaves and canopy.

关键词： photosynthesis light response curve broadleaved Korean pine forest eddy covariance method.

Preconcentration and determination of trace copper(II) in natural water using silica gel modified with 1-(2-pyridylazo)-2-naphthol

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Journal of Environmental Sciences 1989年第1期1卷 121-124页

作者： Tong Shenyang, Liu Feng, Li Kean Department of Chemistry,Peking university,beijing china

Trace copper (II) in water can be preconcentrated using silica gel modified with 1-(2-pyridylazo)-2-naphthol (PAN) and be determined spectrophotometri-cally. The conditions for the preconcentration were studied. The method was applied to both artificial and natural water samples and the results suggest that copper (II) of ppb level in water can be measured accurately after the preconcentration.

关键词： PAN silica gel copper preconcentration.

非完整系统的Noether对称性与Hojman守恒量

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物理学报 2004年第5期53卷 1271-1275页

作者：罗绍凯郭永新梅凤翔浙江工程学院数学力学与数学物理研究所辽宁大学物理系沈阳110036 北京理工大学理学院北京100081

研究非完整力学系统的Noether对称性导致的非Noether守恒量———Hojman守恒量 .在时间不变的特殊无限小变换下 ,给出系统的特殊Noether对称性与守恒量 ,并给出特殊Noether对称性导致特殊Lie对称性的条件 .由系统的特殊Noether对称性 ,... 详细信息

研究非完整力学系统的Noether对称性导致的非Noether守恒量———Hojman守恒量 .在时间不变的特殊无限小变换下 ,给出系统的特殊Noether对称性与守恒量 ,并给出特殊Noether对称性导致特殊Lie对称性的条件 .由系统的特殊Noether对称性 ,得到相应完整系统的Hojman守恒量以及非完整系统的弱Hojman守恒量和强Hojman守恒量 .给出一个例子说明本结果的应用 .

关键词：分析力学非完整系统 Noether对称性非Noether守恒量 Hojman守恒量广义坐标