唐可肽对糖尿病大鼠血脂及脂质过氧化作用的影响

目的探讨唐可肽对糖尿病大鼠脂代谢及脂质过氧化作用的影响。方法用高糖高脂饲料及小剂量链脲佐菌素(streptozotocin,STZ)建立糖尿病大鼠模型,并将成模大鼠分为唐可肽高、中、低剂量组和模型组,同时采用正常的SD大鼠为对照组。唐可肽干预8周后检测各组大鼠的血脂、抗氧化酶和过氧化产物水平,观察肝脏组织的形态学变化。结果与模型组相比唐可肽各剂量组能明显减低糖尿病大鼠血清甘油三酯(triglyceride,TG)、游离脂肪酸(free fatty acids,FFA)和丙二醛(malondialdehyde,MDA)的含量(P<0.05);中、高剂量组能明显降低糖尿病大鼠血清总胆固醇(total cholesterol,TC)的含量,提高超氧化物歧化酶(superoxide diamutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)的活力(P<0.05);高剂量组能升高高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)而降低低密度脂蛋白胆固醇(low density lipoprotein cholesterol,LDL-C)的水平(P<0.05)。唐可肽高、中、低剂量组对糖尿病大鼠肝脏组织的脂肪变性有不同程度的缓解作用。结论唐可肽可调节糖尿病大鼠脂代谢紊乱,提高其抗氧化能力,改善其肝脏组织的脂肪变性。     

β2肾上腺素能受体基因多态性与维吾尔族肥胖的关系

目的探讨β2肾上腺素能受体(β2-adrenergic receptor,β2-AR or ADRB2)基因R16G、Q27E多态性与新疆维吾尔族人群肥胖发生的相关性。方法采用Taqman技术对新疆754例维吾尔族受试者进行β2-AR基因R16G、Q27E位点基因分型,并分析各基因型和等位基因频率在不同体重指数(BMI)水平的分布及其与超重、肥胖的关系。结果维吾尔族人群中超重组与肥胖组的血压、甘油三酯及胆固醇水平显著高于正常体重组(P<0.05)。R16G、Q27E两个多态位点的基因型频率与等位基因频率在正常体重组、超重组与肥胖组之间的分布均无统计学差异(P>0.05);按性别分层后基因型与等位基因频率的分布在3组间亦未见统计学差异。R16G、Q27E多态构成的4种单倍型在正常体重组、超重组与肥胖组的分布无统计学差异(P>0.05)。维吾尔族与汉族人群间比较,Q27E基因型与等位基因频率分布的差异有统计学意义(P<0.001)。结论β2-AR基因R16G、Q27E多态性与新疆维吾尔族人群肥胖发生无关,但Q27E基因型与等位基因频率分布在汉族与维吾尔族人群间不同。     

深水海底管线铺设自动焊接技术研究

介绍深水海底管线铺设自动焊接设备的研制以及自动焊接工艺方案的设计与实施,通过管道焊接接头超声检验和力学性能试验证明,采用双车双炬焊接成功的管道接头均符合API STD 1104-2005要求。在建造场地模拟试验的基础之上,成功地进行了自动焊接海上试验。     

搅拌楼粉料储存输送系统的节能分析与改进

为了解决搅拌楼(站)粉料储存输送系统的节能问题,根据机械设计节能基本原理对沥青和水泥搅拌站粉料输送系统进分析与改进.通过分析得出了现有粉料输送系统工作过程中消耗电能较高的原因;通过对现系统的结构改进和优化设计得到了相对比较节能的粉料输送系统,可为该系统的节能研究及产品研发提供新的方法.     

支持向量机和遗传算法组合策略的VLCC船中结构优化设计(英文)

In this paper a hybrid process of modeling and optimization,which integrates a support vector machine(SVM) and genetic algorithm(GA),was introduced to reduce the high time cost in structural optimization of ships.SVM,which is rooted in statistical learning theory and an approximate implementation of the method of structural risk minimization,can provide a good generalization performance in metamodeling the input-output relationship of real problems and consequently cuts down on high time cost in the analysis of real problems,such as FEM analysis.The GA,as a powerful optimization technique,possesses remarkable advantages for the problems that can hardly be optimized with common gradient-based optimization methods,which makes it suitable for optimizing models built by SVM.Based on the SVM-GA strategy,optimization of structural scantlings in the midship of a very large crude carrier(VLCC) ship was carried out according to the direct strength assessment method in common structural rules(CSR),which eventually demonstrates the high efficiency of SVM-GA in optimizing the ship structural scantlings under heavy computational complexity.The time cost of this optimization with SVM-GA has been sharply reduced,many more loops have been processed within a small amount of time and the design has been improved remarkably.     

Multi-Objective Optimization of Torsion Springs for Solar Array Deployment

For solar array deployment, most existing studies mainly focus on modeling method of deployment dynamics, characteristics of hinges, and synchronization mechanisms. However, torsion springs, which work as the drive mechanisms, have hardly attracted people’s attention. In this study, the influence of the parameters of torsion springs on the deployment behavior of a solar array system with clearance joint is investigated by simulation experiments. The experimental results indicate that the deployment performances are very sensitive to the parameter values of the torsion spring. Suitable torsion springs are highly needed to improve the deployment dynamics of solar array system. Therefore, a multi-objective optimization method for the design of torsion springs is proposed. The objective of the optimization is to make the contact-impact force in revolute joint and the mass of the torsion spring minimum under the constraints of deployment time and structure strength. Finally, the effectiveness of the multi-objective optimization method is verified by an optimization example of solar array system.     

微波养护车加热系统改进方案研究

提出了微波养护车加热系统采用高压发电技术的方案,分析了全波供电方案和分波供电方案的适用性及优缺点,给出了半波整流电路和全波整流电路的试验数据及分析结果,证明了高压发电机在微波养护车上使用的可行性,得出:全波或者半波电路都可以用来作为磁控管供电电路。     

城市交通管理的国民经济效益评价方法研究

在对比分析现有国民经济效益评价方法的基础上,本文从时间节省、燃油节约和交通事故减少3个方面提出了适合我国国情的国民经济效益评价的模型与方法,探讨了模型中主要参数的计算方法和取值。以178个城市3年来的统计数据为基础进行了应用研究,结果表明,模型能够较为合理的对交通管理产生的国民经济效益进行评价。     

水平定向钻机智能化控制系统方案设计

针对水平定向钻机的实际工作情况提出了控制系统的设计目标.在此基础上,基于可编程逻辑控制器和专用控制器分别提出了水平定向钻机的智能化控制系统方案,并对其优缺点进行了分析.     

微波加热旧沥青混合料的应用研究

针对沥青厂拌热再生中出现的旧料加热问题，以实验为基础，从级配、含水量2个方面对微波加热旧沥青混合料的加热效率及影响因素进行了研究，得出了一些有价值的结论，为微波加热旧沥青混合料厂拌设备的应用提供了参考依据。