Correlation of liquefaction resistance with shear wave velocity based on laboratory study using bender element

INTRODUCTION Evaluation of soil liquefaction resistance is an important aspect of geotechnical engineering practice, and several types of evaluating procedures have evolved over the last three decades. The well known “simplified procedure” originated by Seed and Idriss (1971) can be used to evaluate liquefaction resistance based on standard penetration test (SPT) blow counts. Over the years, the simplified procedure has been modified and updated with additional data, and has become th…     

水洞试验中阻塞比对阻力测量影响的数值模拟

为了使表面形貌减阻效果的水洞试验结果可以模拟和预测自由边界的结果、使水洞试验中验证过的有效减阻措施可以成功运用到无限场的情况，该文采用当今最流行的数值模拟方法，基于FLUENT软件对有水洞壁的模型试验和自由边界的无限场模型进行模拟。结果表明，水洞试验的阻塞比不得超过25％，否则在水洞试验中验证的有效减阻措施将无法应用到自由边界的无限场。在水洞试验阻塞比的有效范围内，随着阻塞比的增大或来流速度的增大，表面摩擦系数随之增大。     

Minimax线性估计中的Cook距离与相关系数

本文讨论Minimax线性估计中的影响度量—Cook距离与相关性之间的关系。建立了Cook距离与相关系数之间的等式关系,Cook距离与复相关系之间的不等式关系。     

椪柑的营养水平与其产量的相关性

作物多元素的营养水平与其产量的相关性研究至今尚未见文献报导。本文提出了多元素营养水平的计算方法:即把各个营养元素的浓度均换算成氮素浓度来表示,并根据各个营养元素对于产量的贡献进行加权,以加权总和来表示多元素的营养水平。回归分析结果表明,椪柑多元素的营养水平与其产量呈正相关,相关系数高度显著(P<0.01)。此外,本文还提出了椪柑的营养断诊标准。     

基于改进自适应TV模型的全自适应去噪算法

为使保边性更好的去噪模型在邻近图像边缘处得到应用,同时在图像平坦处得到平滑性更好的模型,解决选择单一的正则项系数对图像处理结果造成的不良影响,有效地自适应选取正则项系数,采用基于小波变换的图像分割技术将图像分为边缘区域和平坦区域,通过修改TV模型的数值解法和ROF算法,实现自适应正则项系数算法。实验结果表明,改进的模型和自适应正则项系数选取算法得出的图像,均方误差为56.69,峰值信噪比为31.00,平均相似度为0.84。改进的TV模型在图像去噪效果方面优于原模型,自适应正则项系数算法能够弥补原图像去噪方法的不足。     

浅谈磷酸分布曲线的应用

本文根据磷酸的分布曲线推导出NaH2PO4和Na2HPO4水溶液氢离子浓度计算的最简公式．     

考虑高阶相关性的灌注桩沉降可靠度分析

为精准确定灌注桩的沉降,将桩周土体参数看作随机变量,并采用响应面法对桩基可靠度进行研究。由于,与桩沉降相关的多个土体参数之间高阶项可能存在高度相关性,基于高阶正交原理提出了新型非相关响应面法,以克服传统响应面法不考虑高阶参数高阶相关性的难题。结合实际工程计算发现,提出的新型响应面法比传统响应面法得到的值更为保守。可见,如果不考虑参数的高阶相关性,可能导致高估的计算结果。     

Auto-Ignition and Heat Release Correlations for Controlled Auto-Ignition Combustion in Gasoline Engines

Auto-ignition and heat release correlations for controlled auto-ignition(CAI)combustion were derived from extensive in-cylinder pressure data of a four-stroke gasoline engine operating in CAI combustion mode.Abundant experiments were carried out under a wide range of air/fuel ratio,speed and residual gas fraction to ensure that the combustion correlations can be used in the entire CAI engine operation range.Furthermore,a more accurate method to compute the residual gas fraction was proposed by calculating the working fluid temperature at the exhaust valve close timing in the experiments.The heat release correlation was described in two parts,one is for the first slower heat release process at low temperature,and the other is for the second faster heat release process at high temperature.Finally the heat release correlation was evaluated on the single cylinder gasoline engine running with CAI combustion by comparing the experimental data with the 1-D engine simulation results obtained with the aid of the GT-Power simulation program.The results show that the predicted loads and ignition timings match closely with the measurements.     

非智力因素对教学过程的影响及其定量分析

非智力因素对教学过程影响的定量化分析,可以使教育工作者从中看到各种非智力因素对教学过程的影响并非等同,从而使教师在今后的教学中有针对性地对学生进行非智力因素的培养,以达到事半功倍的效果。     

诠释空调器的能效系数

本通过严格的计算以及结合实际空调器性能参数的分析发现：1、空调器的能效系数可以大于1，一般在2－3之间取值。2、能效系数大于1并不违反能量守恒定律。