五个人的精彩NOA US SPURS

不知道大家看过上期SK和公牛队的对比后有何感想,是不是早已有两支队伍在你的心里亲密接触了呢?是的,世界就是如此的奇妙,事情与事情之间也存在着千丝万缕的联系。两个看似风马牛不相及的东西却也总有一些相似之处,那就更不要说篮球和CS战队之间了,要是你的想象力够丰富的话,拿CS战队和高尔夫球作比较也未尝不可啊,没准那天泰格伍兹就成了你心目中的Johnny.R也说不定。

A study of the effect of local scour on the flow field near the spur dike

The flow field near a spur dike such as down flow and horseshoe vortex system(HVS)are susceptible to the topographic changes in the local scouring process,resulting in variation of the sediment transport with time.In this study,large eddy simulations with fixed-bed at different scouring stages were conducted to investigate the changes in flow field.The results imply that the bed deformation leads to an increase in flow rate per unit area,which represent the capability of sediment transportation by water,in the scour hole.Moreover,the intensity of turbulent kinetic energy and bimodal motion near the sand bed induced by the HVS were also varied.However,the peak moments between the two sediment transport mechanisms were different.Hence,understanding the complex feedback mechanism between topography and flow field is essential for the local scour problem.

Two Studies Carried out in the SPURS Program

The SPURS program in MIT provides an encouraging environment for fellows to carry out studies on a wide range of topics. In this essay, I briefly describe the two research works I finished as part of SPURS in 2016. One of them originated from the shared interest in affordable housing among SPURS fellows. The other one came from a combination of urban study with my previous study on architectural history and theory. Besides a short description of the contents and conclusions of these projects, this essay also illustrates the positive impacts the SPURS program made on my current work and studies.

Design & Beyond Design:Inspirations from the SPURS Program at MIT

As a SPURS fellow at the Massachusetts Institute of Technology(MIT) from August 2014 to June 2015, I had a great opportunity to participate in many MIT courses and professional trips and interviews offered by SPURS. Based on this experience, this paper discusses inspiration gotten from American planning practice and education, such as the Big-Dig of Boston the High Line Park of New York, involving complicated space shaping content, pre-simulation analysis, continuous post-evaluation of policy-making, and cross-disciplinary research for urban problem solving.

Absence Makes the Heart Grow Fonder:My SPURS Experience and Reflections on Planning Education in China

As a SPURS fellow, my one-year study at MIT had a great impact on my career in urban planning and education. I gained knowledge regarding planning systems in the USA, and my view on planning was changed and expanded. This paper reviews my experience as a SPURS fellow at MIT, and concludes with an analysis of planning education in China from the perspective of a SPURS fellow.

China’s IP protection spurs growth of foreign patent filings

Japan,the United States and Germany topped the list of the most patent filings in China in 2019,according to the China’s National Intellectual Property Administration(CNIPA).Market entities from 186 countries and regions applied for patents and trademarks in China in 2019.Japan.

Revolutionary Base Spurs Development

MAO Zedong’s Autumn Harvest Uprising spurred not only revolution but development and innovation among the masses. In October 1927, Mao Zedong led troops to Jinggang Mountain, establishing the first revolutionary base. During the 1960s, many young people went to work at Jinggang Mountain and devoted their youth to this revolutionary base. The open-minded and shrewd

苹果Co基因的SSR标记定位(简报)

柱型苹果,其特征是节间高度短缩,腋芽萌发为大量的短枝,很少或无侧生延长新梢,呈自然单干形g-4].柱型苹果几乎不需要修剪,非常适合于高密度栽植[5],可以极大地提高土地利用率.因此,柱型苹果是苹果株型育种的一个重要基因资源.

基于MATLAB/GUI的直齿圆柱齿轮齿厚计算软件设计（英文）

在齿轮的测量和进一步的分析中,常用到分度圆以外的其他圆上的齿厚,传统的方法就是通过人工进行计算,计算量大,且易出错。为了解决以上问题,利用MATLAB/GUI功能,开发直齿圆柱齿轮齿厚计算软件,在MATLAB/GUI添加相应的控件,并在相应的回调函数中编写程序,以实现相应的计算功能。计算实例表明:本文设计开发的计算软件具有一定的实用价值。

The equation and the parameter of the spur system

The regular position of radioloops in the sky and their angular dimensions are described by an equation with a single parameter 2 π/к. Thus, for loops I-IV к takes values 3, 4, 6 and 9 within average random observational errors;and the relative accuracy is only few percent. The parameter form is similar to the wavelength, expressed via the wave number к. It is an argument for the hypothesis of wave nature of spurs. Other arguments are considered as well.

EFFECT OF INVOLUTE CONTACT RATIO ON THE DYNAMIC PERFORMANCE OF SPUR GEAR WITH NOTOOTH PROFILE MODIFICATION

The effect of involute contact ratio on the torsional vibration behavior ofspur gear-pair is studied analytically through a mass-spring model. The tooth stiffness in model notonly has a relation with time, as many prior studies presented, but, more important, with involutecontact ratio (ICR) as well. The ICR embodies its impact on the spur gear's dynamic performancethrough changing the proportion of tooth stiffness when there are n+1 teeth in contact to toothstiffness when there are n teeth in contact. A couple of curves about impact of ICR on the gear'sdynamic performance are presented, and they clearly demonstrate that the model can accuratelydescribe the effects of ICR on dynamic transmission error. Finally, some conclusions useful toreduce vibration and noise of gear-pair are proposed.

Experiments and numerical simulations on transport of dissolved pollutants around spur dike

The flow field around a spur dike has three-dimensional characteristics. In order to analyze the influence of the flow field on pollutant transport, based on a compressive volume of fluid （VOF） scheme, the three-dimensional transient compressive pollutant transport model （CPTM） and the cubic equation （CE） bounded differencing scheme were developed. For the calibration and validation of CPTM, laboratory experiments were carried out in a flume with a non-submerged spur dike. The spur dike was angled at 60°, 90°, and 120° from the upstream direction. The simulation results agreed with the experimental results. The simulations and experiments showed that the distribution of pollutant concentration was determined by circumfluence and the main flow. Concentration decay in the circumfluenee zone was slower than that in the main flow. Downstream of the spur dike, the concentration fluctuation became intensive with the increase of spur dike angle.

Influence of Spur Dike on Hydrodynamic Exchange Between Channel and Shoal of Generalization Estuary in Physical Model Test

Widely applied in maintaining estuarial waterway depth, the spur dike has played an important role in currents and sediment exchange between channel and shoal and sediment back-silting in the channel. Through establishing a generalized physical model at a bifurcated estuary and conducting current tests under the joint action of runoff and tide, the influence of the spur dike length on current exchange between channel and shoal is analyzed. Results show that when the spur dike length reaches a certain value, the direction of the flow velocity shear front between the channel and shoal will change. The longer the spur dike, the larger the transverse fluctuating velocity at the peak of flood in the channel shoal exchange area, while the transport of the transverse hydrodynamics is obvious in the process of flood. There is an optimum length of spur dike when the shear stress in the channel and the longitudinal velocity in flood and ebb reach the maximum, and the flow velocity will decrease when the spur dike length is smaller or larger than the optimum. For a certain length of spur dike, the larger the channel shoal elevation difference, the larger the peak longitudinal flow velocity in the middle of the navigation channel in flood and ebb. However, the transverse flow velocity will first decrease and then increase. The transverse transportation is obvious when the channel shoal elevation difference increases.

STUDY ON THE LUBRICATION FACTOR OF INVOLUTE SPUR GEARS

Based on a lot of numerical solutions to the problems of the thermalnon-Newtonian elastohydrodynamic lubrication and some fatigue tests with rollers, the lubricationfactor of involute spur gears (called gear for short) is investigated. The results suggest that gearlubrication effects bear close relations to a dimensionless parameter D which is syntheticallydetermined by gearing rotational speed, load, material, dimension and lubricant viscosity. When D<=8, the gear fatigue life increases as the lubricant viscosity is increased; When D>8, however, thelife decreases with the viscosity addition, which is in marked contrast to the lubrication factorZ_L recommended by the International Standard for Computing Cylindrical Gear Strength. At the end, aset of formulae for calculating gear lubrication factors suitable for different working conditionsare advanced.

Nonlinear Dynamic Analysis of Coupled Gear-Rotor-Bearing System with the Effect of Internal and External Excitations

Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out. However, the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated. An eight-degree-of-freedom（8-DOF） nonlinear spur gear-rotor-bearing model, which contains backlash, transmission error, eccentricity, gravity and input/output torque, is established, and the coupled lateral-torsional vibration characteristics are studied. Based on the equations of motion, the coupled spur gear-rotor-bearing system（SGRBS） is investigated using the Runge-Kutta numerical method, and the effects of rotational speed, error fluctuation and load fluctuation on the dynamic responses are explored. The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion, quasi-periodic motion, chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations. Significantly, the changing rotational speed could effectively control the vibration of the system. Vibration level increases with the increasing error fluctuation. Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase, the chaotic motion may be restricted. The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.

Effect of integral squeeze film damper on vibration and noise of spur gear with center-distance error

When the actual installation center distance between a pair of spur gears is greater than the theoretical center distance,backlash increases,leading to increased vibration and noise.The structural parameters of an integral squeeze film damper(ISFD)were designed with the stiffness of rigid support as reference to investigate the effect of an ISFD on the dynamic characteristics of a spur gear transmission system with center-distance installation error.A spur gear test bench with center distance-error was built to investigate the vibration and noise reduction characteristics of ISFD.The experimental results indicate that,compared with a rigid support,the ISFD can reduce vibration by approximately 40%and noise by approximately 5 d B.ISFD can effectively absorb the impact energy caused by an increase of in backlash,which is conducive to the stable operation of the spur gear transmission system.

Microelements Distribution in Sulfides from Black Smokers of Hydrothermal Vent Field Broken Spur(MAR)

Numerous investigations on submarine hydrothermal ore-forming occurrence have been actively carried out in the last two decades with significant results.The Ag and Au enrichments in the sulfides from black smokers ofhydrothermal vent field Broken Spur(MAR) aroused our interest to study their mineral hosting forms.Samples were collected from seven hydrothermal chimneys within Broken Spur in the British-Russian BRAVEX(1994) and

Effects of Spur Dyke's Orientation on Bed Variation in Channel Bend

Spur dykes also known as Groynes are often used to either divert or attract the flow from the main structure to safeguard their life.Those structures may be bridge piers,abutments or any similar hydraulics structures.Spur dykes are also used to save the cutting of banks on concave side of stream.Lots of work have been done in recent past on spur dykes by many investigators in which various hydraulic and geometrical parameters of spur dykes such as discharge,sediment size,flow velocity,shear stress,spur dykes shape,size and submergence etc.are studied in detail.But mostly all the studies were pointed out in straight open channels.Very few studies were done in curved channel and only their similar effects were studied.In present thesis main emphasis is given to study the effect of orientation and location of spur dykes in meandering channel on the bed of downstream side.In the present study experimental work has been carried out in 80°bend and constant discharge(Q=4.5 l/s)is allowed to pass in channel without spur dyke.It is found that maximum scouring occurs at angular displacementθ=60°to 80°in the vicinity of outer bank.To minimize this scouring,spur dyke has been installed at angular displacementθ=20°,40°&60°by changing the dyke angleα=60°,90°&120°respectively.It is found that scouring atθ=60°is reduced by installing spur dyke at angular displacementθ=40°which is oriented atα=60°and scouring atθ=80°is reduced by installing spur dyke at angular displacementθ=60°which is oriented atα=60°.