岩溶地面塌陷形成机理与成因模式研究——以山东泰安—莱芜为例

山东省泰安—莱芜地区自20世纪70年代中期开始就陆续由于岩溶水的排除而出现严重的地面塌陷,属于隐伏灰岩区岩溶地面塌陷,给当地社会和经济发展带来了巨大危害。总结归纳了该地区岩溶地面塌陷的时空分布特征,论述了其产生的地质条件和人为诱发因素,探讨了岩溶地面塌陷的形成机理,并针对存在的问题探索了其成因模式,最后给出了今后该类研究的思路。     

Theoretical Analysis of Diffraction Efficiency of Photocarrier Grating

The diffraction efficiency of the photocarrier grating (PCG) has been theoretically analyzed. Firstly, the model of the PCG has been set up, and the distribution of the carrier concentration has been studied. Secondly, the change in refractive index produced by the photocarriers has been estimated. Finally, a rigorous coupled-wave analysis has been employed to investigate the diffraction efficiency of the PCG. The results show that when the angle between the two excitation lasers increases, the change of the refractive index decreases, leading to a weak grating. The optimal incident angle of the probe laser is dependent on the angle between the two excitation lasers, and the relation between these two angles for the higher diffraction efficiency of the +1st forward-diffracted wave has been found. In terms of diffraction efficiency, the optimal parameters have been estimated, and the feasibility of the PCG to be a forward-diffracted component has been confirmed.     

Replies to the comments on “Faber series method for plane problems of an arbitrarily shaped inclusion [1]”

This work presents a brief introduction to the Faber polynomials and Faber series in order to reply to the comments made by Prof. Y. Z. Chen on “Faber series method for plane problems of an arbitrarily shaped inclusion (Luo and Gao in Acta Mech 208:133–145, 2009),” and finally, it is shown that his comments and conclusion are hasty and incorrect.     

谈钢琴视奏

视奏是钢琴演奏者必须具备的基本功,培养良好的视奏能力,可以迅速地把握钢琴作品的整体结构,提高练琴的效率和质量,也有助于在较短的时间浏览大量的钢琴作品.视奏应作为钢琴学习一个重要的内容,并贯穿始终.     

先秦台型建筑(连载十八)

该文对中国先秦台型建筑的渊源及其演变通过对相关文献研究中的引得作了系统的疏理。     

基于PC104总线的变电站自动抄表系统

介绍了一种基于PC104总线的变电站自动抄表系统,对PC104的应用特点进行了描述,给出了系统的硬件结构及软件流程图,阐述了系统软、硬件的设计思想和具体实现方法。     

自动化控制系统及安全连锁在医药工业生产中的应用

本文重点介绍自动化设计和自动化改造,使企业在实现自动化以后,突破生产过程关键参数的检测问题;完善了被控对象的控制方案问题,而且合理地建立企业网络信息平台,同时做好了各环节的基础工作,使化学制药的自动化建设变成现实。真正在经济效益、技术进步、生产安全上,取得了明显的效果。     

Novel high-energy ionic molecules deriving from new monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties

ABSTRACT

In recent years, the exploration of a practical strategy for novel energetic molecules with high energy and low sensitivity is very desirable but highly challenging. Novel ionic energetic molecules have attracted much attention in this area due to their prominent advantages including low sensitivities, high thermal stability, and excellent energy performances. Herein, five different ionic energetic molecules based on new monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties with enhanced oxygen balance have been synthesized, characterized and evaluated as potential high-energy materials. Thermal stability, sensitivities and energy output test were measured and studied in detail. The heats of formation and energetic parameters were calculated by using Gaussian 09 suite of programs and EXPLO 5 code. The results suggest that all as-prepared new molecules exhibit good thermal stability with high decomposition temperature (3, 231°C; 5, 160°C; 6, 185°C; 7, 180°C; 8, 213°C), and relative low sensitivity (IS > 20 J, FS = 324 N). Inheriting the significant oxygen content of monovalent and divalent 4-oxyl-3,5-dinitropyrazolate moieties, they also possess good energy properties (v _D = 8238 ~ 9208 m s^?1, P = 26.8 ~ 36.7 GPa, V _o = 481.8 ~ 959.4 L kg^?1), which make them competitive high-energy materials.     

提高晶闸管di/dt能力的研究

从di/dt损坏机制、定量公式入手,分析了国内外有关di/dt的著作、文章,研究了提高晶闸管器件di/dt能力的各种有效方法,给出了一个常规新设计及其研究成果。     

Faber series method for plane problems of an arbitrarily shaped inclusion

This paper presents the theoretical and numerical results for the plane problem of an arbitrarily shaped inclusion in an infinite isotropic matrix based on the Faber series method. The key of the method is to express the complex potentials in the arbitrary inclusion in the form of Faber series with unknown coefficients and then substitute them directly into the boundary conditions on the interface. These conditions lead to a set of linear equations containing all the unknown coefficients. Through solving these linear equations, one can obtain the complex potentials both inside the inclusion and in the matrix. Then, numerical results are presented and graphically shown for the cases of an elliptic, square, and triangle inclusions, respectively. It is found that as the stiffness of the inclusion increases, the hoop stress decreases at the rim of the inclusion, while the radial and shear stresses increase. Especially, it is also found that the stresses show the nature of intense fluctuations near the corners of the triangle inclusion, since the inclusion in this case is similar to a wedge.