广义Ekeland变分原理的推广

给出了经典Ekeland变分原理的一个推广,完善并改进了已有文献的证明,并把它推广到了拟度量空间上.     

《普洱茶文化赏析》通识课“三合一”教改实践与反思

在深化教育领域综合改革大背景下,近两年来,大理学院面向全校各专业学生开设的《普洱茶文化赏析》通识选修课,积极适应教育发展改革新形势;将课堂教学、实训、大学生创业指导"三合一",创新教改模式,不仅使学生学到通识教育知识,还培养其创新创业能力,提高学生的实践实训能力,在教改实践中取得了较好效果,受到学生普遍欢迎。     

Hemingway’s Political Views in His First Period of Creation

Based on the influence of different relationship between general ideology and authorial ideology on Hemingway＇s works in the first period of his creation, the thesis aims to study the different reflection of his political interest from the perspective of ideology.     

两类图完美匹配的计数公式

利用划分、求和、再递推的方法给出图2-nRO_8和图2-F_(2n+1,4)完美匹配数目的计算公式.进一步,用所给的方法可计算出许多图类的所有完美匹配的数目.     

再论线性矩阵方程的解法

目的进一步研究线性矩阵方程的解法。方法利用矩阵的初等变换法。结果给出了矩阵方程AX=B,XA=B和AXB=C的新的通解公式和一般解法。结论使已有的相关方法得到改进。     

Serum levels of perfluorinated compounds in the general population in Shenzhen, China

Perfluorinated compounds (PFCs) have been detected in many environmental matrices, biota, and nonoccupationally exposed populations in China recently. However, little is known about the distribution and levels of various PFCs in the general population living in areas where there is PFC exposure. In the present study, the levels and prevalence of ten target PFCs were determined in 227 serum samples from a population of nonoccupationally exposed individuals in Shenzhen, China. Results indicated that human exposure to PFCs was prevalent in Shenzhen. Perfluorooctanoate (PFOA) was the dominant PFC contaminant in the serum samples, with a median concentration of 6.72 ng/mL, followed by perfluorooctane sulfonate (PFOS) with a median concentration of 2.07 ng/mL. Other PFCs were detected at much lower concentrations, with median concentrations ranging from 0.02 to 0.87 ng/mL. Statistically, no significant (P>0.05) gender differences were observed for any of the PFCs. Significant (P<0.01) positive correlations were found between age and serum concentrations of the target PFCs, except for perfluorobutane sulfonate (R = 0.16, P = 0.01), perfluorohexanoic acid (R = 0.08, P = 0.22), and perfluoroheptanoic acid (R = 0.11, P = 0.10). Based on the one-compartment pharmacokinetic model, the total daily intakes of PFOA and PFOS for the general population in Shenzhen were calculated as 0.63 and 0.20 ng/kg body weight/day, respectively.     

基于马尾松测交系子代的生长、干形和木材密度的配合力分析

利用设置在浙江省淳安县姥山林场的14年生测交系交配设计(测交系未经过一般配合力测定)的遗传测定林,研究马尾松生长、干形和木材基本密度的一般配合力(GCA)和特殊配合力(SCA)及所受的遗传控制。结果表明:马尾松胸径、树高、木材基本密度和干物质积累量皆存在显著的GCA和SCA效应,其全同胞家系遗传力在0.746～0.908间,受较强的遗传控制,其中胸径、木材基本密度和干物质积累量受加性基因效应控制为主、显性基因效应次之,树高受基因的显性效应控制略高于加性效应,而树干通直度完全由加性基因效应影响。统计分析表明,来自中南部的1134、1127和5906测交系其胸径、树高和木材干物质积累量的GCA为正值且较高,而来自北部安徽的3203测交系木材基本密度的GCA最高。在9个待测系中,5476、5158、3205的胸径、树高、木材干物质积累量和树干通直度的GCA均较高,但5476和5158的木材基本密度的GCA则较低,与木材基本密度GCA较高的5910和3205差异显著。马尾松SCA的大小则独立于GCA,因性状和组合而异。依据单株干物质积累量大于总体平均值的20%及树干通直度得分不小于4的选择标准,筛选出7个优良杂交组合,其单株干物质积累量的现实增益和遗传增益分别为22.68%～67.34%和20.25%～60.13%。     

含负项的关联规则挖掘研究综述

关联规则挖掘是数据挖掘研究的一个重要领域,传统的关联规则仅反映了正项之间的关联关系,无法反映出数据之间隐藏的负关联关系.从以下方面对含负项的关联规则挖掘进行了综述:引入负项的原因,包含正、负项的关联规则概念及相关术语,最新的含负项关联规则研究情况,经典算法的讨论.最后,展望了含负项关联规则领域未来的研究方向.     

浅谈高校后勤改革中的与时俱进

在高等教育改革体系中,高校后勤改革已成为社会热点和高校改革工作的重点之一．高校后勤的改革必须从认识、服务、管理、环境等方面与时俱进,从实际出发,科学定位．     

变系数二阶线性微分方程的又一个新的可解类型

本文通过利用未知函数的线性变换和自变量变换,将一类变系数线性微分方程化成二阶常系数线性微分方程,从而得到变系数二阶线性微分方程的一个新的可解类型.