地质工程自动监测硬件系统若干技术问题

地质工程自动监测系统具有监测对象信息变化差异大,监测环境恶劣等显着特点。其硬件系统须具备监测范围广,抗干扰能力强,抗雷击等特殊功能。同时,为了适应现代化工程建设的要求,还应具备先进的智能化和网络化等功能。为此,本文对地质工程自动监测系统的功能和组成、当前的发展趋势及所涉及到一些关键硬件技术问题展开了讨论,着重总结了作者有关地质工程自动监测硬件系统关键技术问题的研究。最后介绍了作者为五强溪水电站边坡工程建立的自动监测系统,以及该系统双端防雷保护和模块化信号调理等难题的解决。     

求一类多元多峰函数全局极小的区间斜率方法

Based on the interval analysis, an interval slope method is proposed for finding all global minimizers of a several peaks function f on domain X^0包含于R^n, which is given by interval slope discard tests and interval extension of objective function.Numerical results of representative test functions show that this method is practical and effective.     

Research on the Longitudinal Section of River Restoration Using Probabilistic Theory

Since the 1960s, many rivers have been destroyed as a consequence of the process of rapid urbanization. As accurate figures are important to repair rivers, there have been many research reports on methods to obtain the exact river slope and elevation. Until now, many research efforts have analyzed the river using measured river topographic factors, but when the flow velocity changes rapidly, such as during a flood, surveying is not easy; and due to cost, frequent measurements are difficult. Previous research has focused on the cross section of the river, so the information on the river longitudinal profile is insufficient. In this research, using informational entropy theory, equations are presented that can calculate the average river slope, river slope, and river longitudinal elevation for a river basin in real time. The applicability was analyzed through a comparison with the measured data of river characteristic factors obtained from the river plan. The parameters were calculated using informational entropy theory and nonlinear regression analysis using actual data, and then the longitudinal elevation entropy equation for each river and the average river slope were calculated. As a result of analyzing the applicability of the equations presented in this study by R² and Root Mean Square Error, all R² values were over 0.80, while RMSE values were analyzed to be between 0.54 and 2.79. Valid results can be obtained by calculating river characteristic factors.     

啁啾sinc取样光纤光栅研究

提出了一种特殊的取样光纤光栅：啁啾sinc取样光纤光栅.研究表明,对于均匀光纤光栅进行啁啾sinc取样,可以实现色散斜率补偿和获得精确的反射波长数控制;对啁啾光纤光栅进行啁啾sinc取样,则能够实现色散和色散斜率的同时补偿,并且可以进行精确的波长数控制及获得各信道一致的反射率.利用啁啾sinc取样光纤光栅,可以对各种传输光纤进行色散和色散斜率的补偿.     

岩质边坡稳定性及预应力锚固分析现状

本文首先对目前常用的各类边坡稳定性分析方法的主要特点进行了评述,包括定性方法类的历史分析法、工程地质类比法、图解法、专家系统法,定量分析方法类的确定性模型法,如极限平衡法,应力应变分析法;非确定性模型法,如可靠性分析法、灰色系统理论法及模糊综合评判法等;及两类方法结合而成的随机有限元法。其次,对预应力锚固边坡的设计及稳定性分析作了阐述。     

Conceptualizations of slope in Mexican intended curriculum

Slope is a fundamental mathematics concept in middle and high school that transcends to the university level. An understanding of slope is needed at the university level since slope plays an important role in understanding problems involving variation and change. In this study Mexican curricula documents were examined to determine which conceptualizations of slope are addressed in the intended mathematics curriculum. To explain the results, we use conceptualizations of slope identified in previous research. Our findings reveal that, to a certain extent, the conceptualizations proposed in the Mexican intended mathematics curriculum differ slightly in terms of the emphasis and timing of instruction from what others have identified in the U.S., with slope as a geometric ratio receiving less emphasis in the Mexican curriculum. There was also noted discontinuity within the Mexican curriculum in introducing slope in grade 9 and subsequently introducing of linear functions in grade 10 without explicit mention of slope. Suggestions are made for future studies, both to consider the conceptualizations of slope promoted in the Mexican textbooks and the impact they have in classroom instruction and student learning of slope.     

凹边坡参数对边坡稳定性的影响

抽象出凹边坡的几何模型,采用量纲分析的方法,给出凹边坡几何参数和物理力学参数对边坡稳定系数的影响通式．在FLAC定义的边坡稳定系数意义下,经过数万次计算,采用二次回归的方法,确定了通式中的影响指数,形成经验公式．结果表明,受Mohr-Coulomb和拉应力两个强度准则控制的材料,形成的凹边坡的稳定性受无量纲粘聚力、边坡角、内摩擦角的控制．凹形边坡有利于边坡的稳定,边坡稳定性与岩土的抗拉强度关系不大．这一稳定系数公式对于形状规则均匀性好且符合Mohr-Coulomb破坏准则的凹边坡可以给出精度高的估计．对于其它边坡的稳定性评价还需要做有针对性的工作．     

基于光谱分析与角度斜率指数的植被含水量研究

植被含水量是植被生长状态的重要指示因子,是农业、生态和水文等研究中的重要参数,其诊断对于监测自然植被群落的干旱状况、预报森林火灾等都具有重要意义。通过对植被光谱反射率与植被含水量的相关性分析,发现植被波谱不同波段的光谱反射率与植被含水量的相关性差异很大,其中可见光红光波段(620～700 nm)、近红外波段(800～1 350, 1 600～1 950, 2 200～2 400 nm)的光谱反射率与植被含水量具有较好的相关性,选取了660,850,1 630和2 200 nm的光谱反射率作为RED,NIR,SWIR1和SWIR2的波段值来建立角度斜率指数;分析了植被含水量与角度斜率指数的关系,将角度斜率指数(SANI,SASI,ANIR)作为反演植被含水量的参量,建立植被含水量与角度斜率指数之间线性回归模型。通过对近红外角度指数ANIR改进,提出了近红外角度归一化指数NANI(near infrared angle normalized index)与近红外角度斜率指数NASI(near infrared angle slope index),建立植被含水量与NANI和NASI之间线性回归模型,结果显示：NANI与Palacios-Orueta等提出的角度斜率指数(SANI,SASI,ANIR)相比有一定的优势,模型可决系数R2从原最高0.791提高到0.853,RMSE也从原最小0.047降低到0.039。确定了NANI为反演植被含水量的最佳角度斜率指数,并建立了植被含水量反演模型。该研究主要创新点：在前人研究成果基础上,通过对原角度斜率指数的改进,提出了NANI和NASI角度斜率指数,使其在植被含水量反演上具有更高的精度。     

基于动量原理的大坡度沥青路面动水压力计算及影响因素分析Calculation and influence factors analysis for hydrodynamic pressure of asphalt pavement with large slope based on momentum theorem

在多雨地区长大纵坡沥青路面是雨天事故多发区域。应用动量定理,建立了沥青路面动水压力的力学计算模型,并系统分析了车辆荷载、行车速度和道路纵坡对动水压力的影响。结果表明,当水膜厚度＜3 mm时,动水压力随车速及车辆荷载的增大而增大,上坡时,动水压力随着纵坡坡度的增大而增大,下坡时,动水压力随着纵坡坡度的增大而减小。当水膜厚度＞3 mm时,动水压力随车速、车辆荷载增大而增大,上坡时,动水压力随着纵坡坡度的增大而增大,下坡时,动水压力随着纵坡坡度的增大呈先缓慢增加然后又缓慢减小的变化趋势;无论是上坡还是下坡,动水压力都随着车轮半径的增大而增大。本研究成果为多雨地区长大纵坡沥青路面重载交通高速行车易发生交通事故提供了理论分析依据。     

Impactless biped walking on a slope

Walking without impacts has been considered in dynamics as a motion/force control problem. In order to avoid impacts, an approach for both the specified motion of the biped and its ground reaction forces was presented yielding a combined motion and force control problem. As an application, a walker on a horizontal plane has been considered. In this paper, it is shown how the control of the ground reaction forces and the energy consumption depend on the gradient of a slope. The biped dynamics and the constraints within the biped system and on the ground are discussed. A motion control synthesis is developed using the inverse dynamics principle proven to be most efficient for human walking research, too. The impactless walking with controlled legs is illustrated by a seven-link biped. The “flying” biped has nine degrees of freedom, with six control inputs. During locomotion, the standing leg has three scleronomic constraints, and the trunk has three rheonomic constraints. However, there are three rheonomic constraints for the prescribed leg motion or three scleronomic constraints for reaction forces of the trailing leg, respectively. The nominal control action for impactless walking can be precomputed and stored. The model proposed allows the investigation of several problems: uphill and downhill walking, optimization of step length, stiction of the feet on the slope and many more. All these findings are also of interest in biomechanics.