自抗扰控制技术在铝电解过程控制中的应用

针对铝电解控制系统的大滞后、大惯性以及动态特性随工况变化的不确定性等特点,本文提出了ADRC技术的氧化铝浓度控制方案。该控制方案能使铝电解过程很快进入稳态,超调量较小,提高了铝电解过程的动态和稳态性能。     

毽球运动在广西普通高校推广的可行性分析

通过文献资料、访谈、数理统计等方法分析在广西普通高校推广毽球运动的可行性。结果表明:毽球运动符合新时期高校体育课程改革的发展趋势;受到广西大部分大学生的欢迎;广西高校开展毽球运动有较好条件;在广西普通高校推广毽球运动是具有可行性的。     

Lipoprotein(a) in Children of Asian Indian Descendants and Their Caucasian Neighbors: The Slovak Lipid Community Study

To elucidate a higher rate of premature cardiovascular disease (CVD) in Asian Indian descendants (Roma) in Slovakia, we investigated frequency distribution, correlates and relationship of lipoprotein(a) [Lp(a)] to family CVD risk factors in Roma children and their Caucasian neighbors. The study sample consisted of 607 healthy children aged 7–18 years (55% Roma, 48% male) as part of the biracial (Roma–Caucasian) Slovak Lipid Community Study. Overall, frequency distribution data of Lp(a) were highly skewed to low concentrations, with markedly higher Lp(a) levels in Roma than in Caucasian children (median and range, mg/dL: 14.5; 0–159.2 vs 6.2; 0–112.3, P < 0.001), regardless of age and gender. Lp(a) was positively correlated with apo B (0.159, P = 0.004) in Roma, and LDL cholesterol (0.170, P = 0.005) in Caucasian children. In addition, daily income of the family was negatively related with Lp(a) in Roma (−0.134, P = 0.036) while positively in Caucasians (0.136, P = 0.047). For both race groups, no significant association was found between Lp(a) and age, body mass index, mean arterial pressure, smoking, and physical activity. Also, no significant relationships were examined between serum Lp(a) levels >30 mg/dL in children and family CVD risk factors, except for diabetes mellitus in parents of Caucasian origin (OR 4.46; 95%CI: 1.23–16.20). In a multivariate analysis, daily income, LDL cholesterol or apo B explained ~7% of the variance of Lp(a). This study suggests a significantly higher serum Lp(a) levels in Roma than in Caucasian children and a small effect, in general, of relevant CVD risk factors on the variation of Lp(a) levels in childhood.     

Angiotensin Converting Enzyme Gene Polymorphism and its Association with Hypertension in South Indian Population

Hypertension, a well known risk factor for various cardiovascular, peripheral vascular and renal events is an important public health challenge. Renin angiotensin system (RAS) being the most vital pathogenic mechanism of hypertension is mediated by a key component; the angiotensin converting enzyme (ACE). The present study was aimed to know the relationship of ACE gene polymorphism and the possible risk of development of hypertension in south Indian population. The study included 101 clinically diagnosed hypertensive patients without any associated disease condition and 81 age and sex matched apparently healthy controls. Genotyping was performed using a polymerase chain reaction, (PCR) amplification of the intron 16 fragment harboring the 287 bp Alu repeat sequence. Three possible genotypes D/D, I/I homozygous and I/D heterozygous were analyzed where the D/D genotypes corresponds to higher ACE levels (D-Deletion, I-Insertion). The PCR products were separated on 2 % agarose gel. Statistical analysis was performed using SPSS.15 software program. We found a significance in frequency of D/D genotype in the hypertensive patients compared to the control group (p = 0.0005, odd’s ratio = 4.157). This suggested that ACE (D/D) genotypes are more prone for the development of hypertension. This is relatively a pilot study; but nevertheless may assist in identifying the pathophysiological cause of hypertension.     

QFD在体育产业经营管理人才培养中的应用研究

为使高校培养的体育产业经营管理人才与社会用人单位之间相互适应,将质量机能展开(QFD)理论应用到体育产业经营管理人才培养中,构建体育产业经营管理人才培养模型。通过该模型的建立,分别构建体育产业经营管理人才质量需求规划矩阵、体育产业经营管理人才培养设计矩阵、体育产业经营管理人才培养设计方案矩阵,最后明确了体育产业经营管理人才培养方案的管理控制过程。     

科技投入与产出的关联性分析——以新疆为例

根据统计年鉴1999～2008年数据,利用灰色关联分析法对科技投入与产出进行关联性计算,并以新疆为例进行实证分析;根据过去十年的科技投入产出状况,利用GM(1,1)模型对2009～2014年新疆科技投入与产出的相关性进行展望。研究结果显示,近十年,新疆科技产出主要由科技活动人员投入数量与投入时间推动;而未来五年,新疆科技产出将由科技经费投入与科技设备投入来推动,预示科技投入活动将由"劳动密集型"向"资金密集型"转型。     

基于ANP-物元理论的综合评价方法及应用

从系统论的观点出发,考虑事物之间的相互关联以及发展变化等特征,提出了一种将网络层次分析法与物元评价法相结合的综合评价方法。确定的权重,能充分反映评价指标之间相互依存和反馈的复杂关系,评价方法能得出事物的发展变化趋势。算例表明,该评价方法是有效和可行的,有利于提高评价结果的准确度和可靠性。     

酚类化合物对蝌蚪急性毒性的定量构效关系研究

对21种酚类化合物进行DFT-B3LYP/6-311G**水平全优化计算,据所得量子化学参数建立酚类化合物对日本长腿蛙蝌蚪24h急性毒性(24h-LC50)的定量构效关系(QSAR)模型。对训练集样本经逐步多元回归分析(SMR)后,所建QSAR模型的相关系数R及去一法(LOO)交互检验复相关系数R2cv分别为0.967和0.882,用预测集样本进行了外部预测,所得外部预测样本复相关系数R2ext和外部预测集交互检验Qe2xt分别为0.988和0.960,表明所建立的QSAR方程具有较好的稳健性和预测能力。模型结果表明:ELUMO愈负,化合物毒性愈强;分子疏水性参数logP较大时具有较大的脂溶性,化合物的毒性较大;极性愈大,毒性愈小。应用域(AD)表征表明建立的模型可以应用于应用域内化合物的毒性预测,具有潜在应用价值。     

碱-硅酸反应和硫酸盐侵蚀复合作用下的混凝土耐久性

碱-硅酸反应(ASR)和硫酸盐侵蚀是影响混凝土耐久性的两个重要因素。目前,对于单一因素作用下混凝土劣化过程的研究已有诸多报道,但关于混凝土在碱-硅酸反应和硫酸盐侵蚀复合作用下的损伤失效过程及机理研究却很少。本文介绍了近年来国内外在碱-硅酸反应和硫酸盐侵蚀方面的研究现状,主要阐述了它们各自的膨胀机理和抑制措施。在对Grattan等人试验中得到的膨胀数据、X射线衍射图和扫描电子显微镜图进行分析的基础上,讨论了混凝土在这两种因素复合作用下可能出现的膨胀值变化和强度变化,并提出有效的抑制措施。     

关系型求职对农民工工作不安全感的影响:社会资本的调节作用

基于社会网络理论,研究在缺乏有效劳动力市场机制的情况下,农民工的关系型求职对其工作不安全感的影响关系,重点关注农民工个体社会资本的调节作用。采用问卷调查的方法,共收集到14家建筑施工企业305个有效样本。研究发现:农民工的关系型求职对其工作不安全感具有显著的负向影响关系;农民工个体社会资本(网络规模、网络成分和网络资源)对其关系型求职与工作不安全感之间的关系具有显著的调节作用,与拥有较低社会资本的农民工相比,拥有较高社会资本的农民工其关系型求职对工作不安全感才具有显著影响关系。最后,针对研究结论的启示和意义进行了探讨。