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A Numerical Study of Second-Order Turbulent Moments in the stably Stratified Nocturnal Boundary Layer

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Advances in Atmospheric Sciences 1992年第2期9卷 201-212页

作者：朱平许小金李兴生 Beijing Institute of Meteorology Academy of Meteorological Science SMAhe structures and the vertical profiles of turbulent variance and covariance of the stably stratified boundary layer (SBL) are simulated with a second-order closure turbulence model. The results confirm that the vertical profiles of the dimensionless turbulence variance and covariance can be well represented by the form F = A(1 - Z / h)x. Here h is the height of SBL. and both exponent a and coefficient A are the functions of terrain baroclinicity radiation cooling and the state of temporal development of SBL. Comparing with Minnesota and Cabauw experiment data we have analysed the value of a and expounded the main reasons that great difference in a exists among different literatures.

The structures and the vertical profiles of turbulent variance and covariance of the stably stratified boundary layer (SBL) are simulated with a second-order closure turbulence model. The results confirm that the vertical profiles of the dimensionless turbulence variance and covariance can be well represented by the form F = A(1 - Z / h)x. Here h is the height of SBL. and both exponent a and coefficient A are the functions of terrain, baroclinicity, radiation cooling and the state of temporal development of SBL. Comparing with Minnesota and Cabauw experiment data, we have analysed the value of a and expounded the main reasons that great difference in a exists among different literatures.

关键词： turbulent turbulence stratified covariance closure exponent Minnesota terrain analysed stably

A MODEL STUDY OF THE stably STRATIFIED BOUNDARY LAYER OVER SLOPED TERRAIN

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Chinese Science Bulletin 1989年第8期34卷 665-668页

作者：李兴生朱翠娟钟世远 Academy of Meteorological Science SMA Department of Atmospheric Science Nanjing University

At night, over sloped terrain the drainage flow can be always caused by cooling: of the air near a sloped surface. Its structure differs from that over horizontal planes. Brost and Wyngaard pointed out that even sligh... 详细信息

关键词： sloped terrain stably stratified boundary layer.

Three-Dimensional Numerical Simulation of stably Stratified Flows over a Two-Dimensional Hill

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Open Journal of Fluid Dynamics 2017年第4期7卷 579-595页

作者： Takanori Uchida Research Institute for Applied Mechanics Kyushu University Kasuga-shi Japan

stably stratified flows over a two-dimensional hill are investigated in a channel of finite depth using a three-dimensional direct numerical simulation (DNS). The present study follows onto our previous two-dimensional DNS studies of stably stratified flows over a hill in a channel of finite depth and provides a more realistic simulation of atmospheric flows than our previous studies. A hill with a constant cross-section in the spanwise (y) direction is placed in a 3-D computational domain. As in the previous 2-D simulations, to avoid the effect of the ground boundary layer that develops upstream of the hill, no-slip conditions are imposed only on the hill surface and the surface downstream of the hill;slip conditions are imposed on the surface upstream of the hill. The simulated 3-D flows are discussed by comparing them to the simulated 2-D flows with a focus on the effect of the stable stratification on the non-periodic separation and reattachment of the flow behind the hill. In neutral (K = 0, where K is a non-dimensional stability parameter) and weakly stable (K = 0.8) conditions, 3-D flows over a hill differ clearly from 2-D flows over a hill mainly because of the three-dimensionality of the flow, that is the development of a spanwise flow component in the 3-D flows. In highly stable conditions (K = 1, 1.3), long-wavelength lee waves develop downstream of the hill in both 2-D and 3-D flows, and the behaviors of the 2-D and 3-D flows are similar in the vicinity of the hill. In other words, the spanwise component of the 3-D flows is strongly suppressed in highly stable conditions, and the flow in the vicinity of the hill becomes approximately two-dimensional in the x and z directions.

关键词： Finite-Difference Method stably Stratified Flows Two-Dimensional Hill

Bacterial diversity in soils subjected to long-term chemical fertilization can be more stably maintained with the addition of livestock manure than wheat straw

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Science Foundation in China 2015年第4期23卷 4-4页

With the support by the National Natural Science Foundation of China and the Strategic Priority Research Program of the Chinese Academy of Sciences,*** Haiyan’s laboratory at the Institute of Soil Science,Chinese Academy of Sciences,reported comparative analysis of bacterial communities in soils that have been subjected to 30years of chemical fertilization(NPK)with the addition of either cow manure,pig manure or wheat straw residues,which was published in Soil Biology&Biochemistry(2015,88:9—18).

关键词： fertilization manure wheat livestock straw maintained residues Strategic amendment stably

Ester Bond Containing Protein:Mechanically Stable Yet Dynamic

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Chemical Research in Chinese Universities 2021年第6期37卷 1352-1353页

作者： ZHANG Wenke State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun130012P.R.China

Gram-positive pathogens can colonize on mucosal tissues stably withstanding large mechanical disturbance from coughing and sneezing by secreting special surface adhesion ***,how these proteins resist mechanical unfolding remains *** a recent work,using single molecule force spectroscopy,Cao et *** that an ester bond containing surface adhesion protein from Gram-positive bacteria,Clostridium perfringenes.

关键词： positive standing stably

A class of rings with PF structures

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Chinese Science Bulletin 1995年第15期40卷 1233-1236页

作者：陈焕艮 Mathematics Department Hunan Normal University Changsha 410006 China

Suppose R be a commutative ring with an identity element 1. Tong Wenting hasstudied PF rings in ref.[1]. A ring R is called a PF ring if every finitely generatedprojective R-module is free. In this note, we construct ... 详细信息

关键词： PF ring K0 group stably free module.

Category X(R) and A-groups

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Science China Mathematics 1995年第2期38卷 159-170页

作者：陈焕艮佟文廷 Department of Mathematics Nanjing University Nanjing 210008 China

New groups: X-groups are constructed. These groups are easy to calculateand they reflect more general properties of rings than K0-groups. As their applications, some characteristics of group rings with torsion-free ... 详细信息

关键词： K0-group stably free module quadratic field.

A NON-AXISYMMETRIC STRUCTURE OF CORONAL MAGNETIC LOOP

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Chinese Science Bulletin 1984年第8期29卷 1028-1032页

作者：王水 University of Science and Technology of China Hefei

Observations of the EUV and the soft X-ray of the sun have revealed many loop-like structures, which are rooted near the region with strong magnetic field in the photosphere, with their upper part extending out into t... 详细信息

关键词： extending corona stably ordinary aligned stationary approximate perturbation representative merged

Low Brittleness FeCrAl Alloy

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China Rare Earth Information 1993年第3期 2-3页

A new electrothermal alloy containing 0.1—1.0 wt% yttrium has been developed by *** Pei andhis coworkers in Baotou Research Institute of *** alloy is characterized by low brittleness,high strength at high temperature,good cold worka-bility,high service temperature,long lifetime and lowoxidation *** experts identified that its compre-hensive property had reached an advanced level incomparison with the same kind of alloy in the world.

关键词： Baotou yttrium lifetime tempera stably