A universal scaling law for hadronic reactions

A master scaling law is proposed for arbitrary distributions in arbitrary hadronic processes of which all experimentally established scaling laws (and a host of others, easily deduced as occasion demands) are special cases.     

The effect of a coriolis force on Taylor-Couette flow

Taylor-Couette flow subject to a Coriolis force is studied experimentally and numerically. In the experiment, the Couette apparatus is mounted on a turntable with the axis of the cylinders orthogonal to the rotation vector of the turntable. The Coriolis force stabilizes the fluid against the onset of Taylor vortices and alters the velocity fields, both above and below the transition from the initial flow. At small dimensionless turntable frequencies, the transition yields time-independent Taylor vortices which are tilted with respect to the cylinder axis. At larger there is a direct transition to turbulence. We determine the first-order correction to the classical Couette initial flow, to account for the effects of the Coriolis force, by expanding in powers of. We present numerical results for the axial velocity (the only nonvanishing correction term to order) in the infinite-cylinder approximation.     

On Stability and Trajectory Boundedness in Mean-square Sense for ARMA Processes

Abstract For the multidimensional ARMA system A(z)y_k=C(z)w_k it is shown that stability(det A(z)≠0,z:│z│≤1)of A(z) is equivalent to the trajectory boundedness in the mean square sense(MSS)which,as a rule,is a consequence of a successful stochastic adaptive control leading the closed-loop of an ARMAXsystem to a steady state ARMA system.In comparison with existing results the stability condition imposed onC(z)is no longer needed.The only structural requirement on the system is that det A(z) and det C(z) have nounstable common factor.     

Epi-Convergence and Lower and Epi-Upper Semicontinuous Approximations in Distribution

The paper introduces an extension of the epi-convergence, the lower semicontinuous approximation and the epi-upper semicontinuous approximation of random real functions in distribution. The new notions could be helpful tools for sensitivity analyzes of stochastic optimization problems. The research is evoked by S. Vogel and continues the research started by Vogel and the author.     

Fourier Transformation of the Renormalization-Invariant Coupling

We discuss integral transformations of the QCD renormalization-invariant coupling (running coupling constant). Special attention is paid to the Fourier transformation, i.e., to the transition from the space–time to the energy–momentum representation. Our first conclusion is that the condition for the possibility of such a transition provides one more argument against the real existence of unphysical singularities observed in the perturbative QCD. The second conclusion relates to a way to translate some singular long-wave asymptotic behaviors to the infrared region of transferred momenta. Such a transition must be performed with the Tauberian theorem taken into account. This comment relates to the recent ALPHA collaboration results on the asymptotic behavior of the QCD effective coupling obtained by numerical lattice simulation.     

完全可压缩渗流驱动问题的特征线有限元方法及其误差分析

多孔介质中渗流驱动问题数值方法的研究，对合理经济地开发油田，了解地下油水运动规律有一定意义。特征线法结合差分或有限元法解渗流问题，在理论和应用上获得了成功３－５，但还有很多问题需进一步研究２．前人研究多是假定流体不可压或微可压，本文研究一类完全可压缩两相驱动问题。采用特征线法与有限元法相结合，构造并分析了全离散数值格式，基于周期性假设，证明了最优Ｌ２模误差估计。     

Effect of optical-phonon scattering on the energy distribution of hot electrons in semiconductors at low temperature

Summary The variational method is used in finding the solution of the transport equation for a system of hot electrons inn-Ge atT=20 K in the presence of high electric field. The role of the emission of optical phonons by hot electrons together with the effect of electron capture by repulsive centres on the formulation of the distribution function are studied. It is shown that the emission of optical phonons plays a dominant role in the formulation of the distribution. The influence of electron capture is very small, it may become appreciable at higher trap concentrations. The obtained distribution function is then used in calculating the capture rate of electrons by negatively charged centres. It is shown that the capture rate increases with electric field.

---

Riassunto Il metodo variazionale è usato per trovare la soluzione dell'equazione di transporto per un sistema di elettroni caldi inn-Ge aT=20 K in presenza di grande campo elettrico. Si studiano il ruolo dell'emissione di fononi ottici da elettroni caldi insieme con l'effetto della cattura degli elettroni da centri di repulsione sulla formulazione della funzione di distribuzione. Si mostra che l'emissione di fononi ottici svolge un ruolo dominante nella formulazione della distribuzione. L'influenza della cattura degli elettroni è molto piccola, può diventare apprezzabile a piú grande concentrazione di trappole. La funzione di distribuzione ottenuta è quindi usata nel calcolare il rapporto di cattura degli elettroni da centri a carica negativa. Si mostra che il rapporto di cattura cresce col campo elettrico.

---

Резюме Используется вариационный метод для нахождения решения транспортного уравнения для системы горячих электронов вn-Ge приT=20 К при наличии сильного электрического поля. Исследуется роля испускания оптических фононов горячими электронами и эффект эахвата электпонов отталкивающими центрами при определении функции распредения. Показывается, что испускание оптических фононов играет доминируюэую роль при образовании функции распределения. Влияние захвата электронов очень мало и становится существенным при более высоких концентрациях ловушек. Полученная функция распределения используется при вычис-лении интенсивности захвата злектпонов отрицательно заряженными центрами. Показывается, что интенсивность захвата увеличивается с возрастанием электрического поля.

     

基于机器视觉的刀具轮廓在线检测方法的研究

超精密单点金刚石车削过程中需要对刀具参数进行检测。基于机器视觉原理,采用新型的机械结构设计了新型刀具在线检测系统。通过垂直放置的两组由同轴远心镜头和CMOS相机组成的光学系统来获取车刀刀尖正面及侧面的图像,再经图像处理系统来获取刀具的轮廓及位置信息,完成对刀具轮廓及位置的在线检测,实验验证可实现测量的重复性定位精度达1μm。在线检测的方式借助了超精密车床自身的高精度和运动机构,可以保证相机焦点和机床主轴之间的相对位置关系,弥补了目前刀具检测系统稳定性差和重复性精度低的不足,提高了加工的整体效率。     

Porphyrin-like porous nanomaterials as drug delivery systems for ibuprofen drug

In recent years, nanomaterial-based drug delivery carriers have become some of the most attractive to be studied. The purpose of this study is to investigate the interaction of C60 fullerene, carbon nanotube and graphene having porphyrin-like FeN4 clusters with a non-steroidal anti-inflammatory drug (ibuprofen) by means of the density functional theory. Results showed that the graphene with FeN4 clusters could remarkably increase the tendency of graphene for adsorption of ibuprofen drug. Also, our ultraviolet–visible results show that the electronic spectra of the complexes exhibit a blue shift toward lower wavelengths (higher energies). It was found that Ibp/FeN4-graphene had high chemical reactivity, which was important for binding of the drug onto the target site. In order to go further and gain insight into the binding features of considered systems with ibuprofen drug, the Atoms in Molecules analysis was performed. Our results determine the electrostatic features of the Ibp/FeN4-graphene bonding. Consequently, the results demonstrated that the FeN4-graphene could be used as potential carriers for the delivery of ibuprofen drug.     

水翼表面粗糙带对空化抑制效果的数值研究

为研究水翼表面粗糙带对空化的抑制效果,在修改的NACA16翼型吸力面施加一粗糙带,对在不同粗糙带条件下翼型的水动力学特性和周围流场进行了数值模拟研究,得到了升阻力系数、吸力面最小压力系数和近壁面湍动能随粗糙带变化的趋势,探讨了水翼表面粗糙带对抑制表面空化的效果。结果表明,随着粗糙带宽度和高度的增大,翼型周围流场的压强显著升高并使吸力面的最低压力高于饱和蒸汽压,从而延缓了初生空化的发生。该结果为认识粗糙带对水翼抗空蚀性能的影响提供了参考。