基于灵敏度分析的地基沉降反演参数优化

土工参数的反分析对地基沉降的准确计算和预测意义很大,但是现有的土体非线性本构模型涉及的计算参数较多,造成了参数反分析的困难甚至误差.基于系统灵敏度分析原理,以一个实际工程为例,说明了E-v模型和E-B模型中计算参数的灵敏度分析的方法,并通过灵敏度分析方法,确定了E-v模型和E-B模型合理的沉降反分析的参数,大大提高了反分析的效率.     

联立方程计量经济学模型系数的一种极大似然估计

对随机扰动ε和系数矩阵B、Γ作了一些假定和约束下，推导出联立方程计量经济学模型的结构式YB=XΓ＋ε的系数矩阵和随机扰动协差阵的极大似然估计的表达式，避免了方程的识别问题，具有一定的实际意义．     

复杂建筑结构加固及其检测方法研究

分析复杂建筑因使用功能改变而进行加固的必要性。结合武昌火车站华中商城加固改造工程实例，探讨了复杂建筑的结构加固的程序与方法，提出这类加固工程处理的新思路：检测原结构一加固设计与施工。加固效果检测。着重介绍了复杂建筑的柱、梁与板的加固设计方法和施工工艺。     

TSVD正则化方法的参数选取及数值计算

对于求解不适定问题的TSVD正则化方法，给出了能达到渐进最优阶的正则参数的后验选取法．从数值实现角度看，TSVD正则化方法是求解不适定问题的十分有效的方法．     

A genome scan for quantitative trait loci affecting grain yield and its components of maize both in single-and two-locus levels

Maize is one of the most important cereal crops in the world. The hybrid yield advantage is responsible for about 10 percent of the total global maize production of 550 Mt[1]. It is exigent to study the yield traits so as to improve the hybrids per se in …     

小波包分析在振动测试信号去噪中的应用

简要阐述了小波分析、小波包分析的基本原理,并在此基础上介绍了利用小波包给信号去噪的一般原理。最后通过计算机仿真,对于一个含有随机噪声的振动测试信号,在默认阈值下比较了小波去噪和小波包去噪效果的不同。     

盘式制动器试验台模拟机的设计

对盘式制动器工作原理及试验原理进行了研究,研制开发出了盘式制动器试验台模拟机.简要介绍了对盘式制动器试验台模拟机主机部分的设计,实现飞轮组的多片组合.设计出驱动制动系统和单片机测试系统,以保证系统的模拟精度.     

大功率LED封装结构的仿真设计

设计针对大功率LED的光学结构进行分析,建立大功率LED的光学仿真模型,模拟LED光强分布曲线,对实测数据和仿真结果进行了比较,重点说明LED封装结构设计方法和思路,最后总结了仿真设计的意义。     

Reappraisal of phylogenetic status and genetic diversity analysis of Asian population of Lentinula edodes

Phylogenetic relationship within the Lentinula genus is constructed based on the sequenced ITS fragments of the 60 Chinese wild L. edodes isolates and the sequence data of 48 isolates of different species from other districts downloaded from the GenBank. The 108 isolates of Lentinula genus are divided into two branches and seven groups, one branch and two groups in the New World, and the other branch and five groups in the Old World, and the isolates clustering of different groups corresponds obviously with the classification of the morphological species. Asian isolates are partitioned in group Ⅰ and Ⅴ, two of the five groups of the Old World, by which the germplasm resources status represented is of great importance shown by the phylogenetic analysis. Group Ⅴ which fills up the blank of geographic distribution has become one of the mainstream groups with an increased isolate number, while group Ⅰ has a tendency to dissimilate into two subgroups (Ia and Ib) with a huge isolate quantity and a coverage of most tested districts, suggesting that China (or Asia) is an important genetic diversity center of the natural population of Lentinula genus. Genetic analysis of Asian isolates based on groups Ia, Ib and group Ⅴ indicates that the diversity of the east coastal-land, northwestern highland and southwestern China and Himalayas districts is the most plentiful, which is the three priorities in diversity protection of Asian Lentinula population.     

环境因子对底栖动物生命活动的影响

底栖动物是水生态系的一个重要组成部分,其生存、种类组成与分布、现存量和生物多样性受到水质、底质、温度、水深等理化因子和水草、底栖动物间、饵料生物、捕食动物等生物因子的影响,本文对在这几个方面的研究进行了归纳,并提出了底栖动物保护和利用的建议.