A NOTE ON THE APPLICATION OF LINEAR WAVE THEORY AT A CRITICAL LEVEL

The purpose of this note is to estimate the accuracy and practical limitations of applying linear theory at a critical level over a realistic range of atmospheric stabilities for an idealized surface terrain. These estimates are made by comparing the results of a linear model with a nonlinear numerical model at a critical level. Essentially similar results are obtained from each model for wave stress, wave breaking height and wave dissipation through the critical level. Because gravity waves can be either evanescent or internal depending on the relative sizes of the Scorer parameter and the wavenumber of the ground surface disturbance, the somewhat paradoxical result develops that wave breaking and non-linearity increase with increasing bulk Richardson number. It is recommended that steady linear wave theory be used in gravity wave drag parameterizations provided near real time profiles of background velocity and temperature are available.     

江苏油田易塌地层分类及泥浆技术的研究

地层矿物组分，理化性能分析是整个泥浆工作中一项极为重要的基础工作，在对江苏地区主要勘探开发区块地层的岩心矿的组分和理化性能分析的基础上，进行地层分类及地层泥浆技术及工艺的适应性研究，制定也富民等2个区块的泥浆技术方案，解决了一些地区的塌垮问题，尤其是近年来在崔庄，码头庄会战中，大大减少复杂事故的发生，缩短了钻井周期，完井周期，保护了油气层。     

基于临界孔隙度模型的地震波传播

基于岩石物里学中临界孔隙度模型,建立一种简洁的均匀弹性流体饱和孔隙介质模型,进行地震波传播研究.首先定义了构建目标模型的基本力学模型:介绍了全孔隙度区间内基本力学模型和目标孔隙介质的含义,其中基本力学模型除了完全弹性固体模型S和完全弹性流体模型F还包括临界孔隙模型C.然后通过等效力学模型推出了目标力学模型介质本构关系的组分表达形式.文中分别通过直接求取弹性参数的表达形式和运用应力应变关系两种方法得到介质模型的本构关系,进而得到该模型波动方程的组分表达形式.最后对这种介质模型进行了地震波传播的数值模拟,结合模拟结果分析孔隙对地震波传播的影响.     

论坡面侵蚀的临界坡度

尽管对坡面水力侵蚀中的临界坡度已作了大量研究，但对临界坡度的大小目前仍无一致结论。本文从坡面流的能量理论出发，对临界坡度进行了研究。结果表明，在流量一定时临界坡度在２４°－２９°之间，其大小视坡面水深与大于等于８４％的坡面颗粒的粒径而定。这一结果与众多室内外试验结果一致，从而从理论上解决了临界坡度的大小问题。     

Thermodynamics under the extended uncertainty principle background: Q−ϕ criticality analysis

The study of thermodynamics in the background of the “extended uncertainty principle (EUP)” comes into interest in recent eras. In this article, we consider a charged black hole (BH) in higher dimensional space–time and present the thermodynamic parameters, based on a semiclassical framework, initially. Then we extend the same within the EUP background. We also analyze the $Q-\varphi$ criticality and find the critical points (${\varphi }_c,Q_c$ and $T_c$) when $Q-\varphi$ criticality appears. We study the effects of EUP on phase transition for higher dimensions ($d=5$) by plotting the $Q-\varphi$ diagrams. Further, we investigate the stability (thermal and global) of the BHs by employing the specific heat and the Gibbs free energy without and within EUP correction and compare the results with the Schwarzschild BHs in higher dimensions.