基于综合集成赋权法的建设用地集约利用时空评价

在对建设用地集约利用及其评价进行系统学解释的基础上,建立一套包括建设用地投入强度、使用强度、利用效率和利用结构四方面的评价指标体系,引入综合集成赋权法以确定参评指标权重。并以湘潭市为例,运用该方法及集约度时空分布模型,对其建设用地集约利用进行综合评价,从而对建设用地集约利用评价方法进行了有益的探索。

城市生活固体废弃物回收处理物流系统的构建与评价

越来越多的城市垃圾严重地破坏了城市的环境,因此,如何有效地回收处理城市垃圾是各国亟待解决的重大问题。在查阅大量有关城市生活固体废弃物回收处理系统实践的基础上,从循环经济的角度,构建了一套城市生活固体废弃物的回收处理物流体系以及综合评价该系统的指标体系,并通过实例给出了科学的评价方法——综合集成赋权法,为城市生活固体废弃物回收处理系统的构建与评价提供了理论参考。

IEEE 802.16中改进的QoS调度算法设计

IEEE802.16标准在每个节点处都提供实时业务和非实时业务。由于基于优先级的业务的服务质量(QoS)的需求不同,因此需要对传统的调度算法进行改进使其具有更大的适应性。为了改善QoS端到端时延的性能,提出了一种混合调度算法(EDD和WFQ算法相结合)。仿真结果表明:在每个节点处,提出的混合算法比仅使用EDD算法能给实时业务产生的时延更少,并且还能够使单个BS在可允许的端到端时延范围内容纳数量更多的子SS,而且使用从BS到SS的GPSS模式的调度机制比使用GPC模式能产生更小的时延。

医用超高分子量聚乙烯的改性及其摩擦学特点

背景:超高分子量聚乙烯因其自身优良的理化性能而被广泛应用于医学领域中的人工关节置换。目的:概述医用超高分子量聚乙烯应用于人工关节假体的摩擦磨损性能及其改性研究进展。方法:以"超高分子量聚乙烯、人工关节假体、摩擦磨损机制、摩削";"Ultra-High Molecular Weight Polyethylene,UHMWPE,artificial joint prosthetics,mechanism of friction and wear,wear debris"为关键词,检索1970至2012年ISI数据库、PubMed数据库,1979至2012年CNKI数据库、万方数据库及维普科技期刊数据库中有关医用超高分子量聚乙烯作为人工关节假体的自身摩擦磨损及改性研究。结果与结论:研究证实超高分子量聚乙烯的主要摩擦磨损机制为磨粒磨损、黏附磨损和疲劳磨损。针对其低耐摩擦性能,目前实验室可以通过无机填料改性法,包括羟基磷灰石、氧化锆、炭黑、碳纤维、碳纳米管等,交联法包括有机硅氧烷偶联剂交联和各种离子辐射等方法进行改性,并在各种模拟环境下所进行的摩擦磨损测试,结果证明这些改性后的材料耐磨性能均得到了不同程度提高。对医用超高分子量聚乙烯应用于人工关节假体的摩擦磨损实验研究体系主要包括摩擦磨损模拟试验机、润滑体液、磨损、磨屑的测定和评价等。

基于综合集成赋权法的主攻方向和突破口决策模型

针对现有主攻方向和突破口决策过程中指标权重确定方法的不足,提出了一种多属性决策方法。首先基于模糊层次分析法确定主观权重、熵权法确定客观权重;然后把主观权重和客观权重综合,使得到的综合权重同时反映主观和客观程度。最后,通过实例分析,说明采用该方法进行主攻方向和突破口选择排序是可行、有效的。

Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress

In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.

一种基于室内场景的多摄像头人体定位算法

室内场景中的人体定位追踪,通常用于智能监控和室内服务机器人的人机交互。传统多摄像头场景人体定位算法思想来源于三维重建,缺点是需要标定的参数众多,实时性较差。而基于主轴的场景人体定位算法虽然实时性好,但是无法处理人体遮挡的情况。基于像素的人体定位算法虽然精度较高,但是实时性较差。本文重新设计了一种非标定的场景人体定位算法,其算法思想是利用检测得到的人体矩形框代替人体前景信息,在矩形框的上边和下边进行采样单应投影,获取人体候选脚点,进行纬度聚类,在簇内根据到簇中心进行权值授予以及依据权值阈值筛选有效候选脚点,最终获取人体脚点位置。实验证明,本文设计的场景人体定位算法不仅精度高,而且速度快。

MRI DWI序列显示健康志愿者骶髂关节成像的最佳b值

背景:MRI DWI序列是一种简单易行、特异性较强、敏感度较高且能早期诊断活动性骶髂关节炎、监测其活动性的检查方法之一,但DWI序列对骶髂关节显示的最佳b值尚无统一标准。目的:通过比较10-20岁健康志愿者骶髂关节MRI不同b值时DWI及表观弥散系数差异,寻找MRI DWI序列显示骶髂关节的最佳b值。方法:随机选择21名10-20岁无骶髂关节疾病的健康志愿者作为研究对象,行骶髂关节轴位T1WI、STIR及DWI扫描(b值为0,300,600,900s/mm2),观察不同b值对骶髂关节的显示情况,对图像进行评价;同时,分别测量双侧骶髂关节的骶侧、髂侧关节旁骨髓的表观弥散系数,对不同b值双侧骶髂关节旁骨髓表观弥散系数进行统计学分析。结果与结论:21名健康志愿者42个骶髂关节在b值为300,600s/mm2时,图像显示清晰,对比度好,能清晰显示骶髂关节关节。b值为900s/mm2时,图像伪影较大,图像质量模糊,对比度差,无法完成表观弥散系数值的测量。b值为600s/mm2时,双侧骶髂关节旁骨髓所测得的表观弥散系数值变化范围小,而b值为300s/mm2时,表观弥散系数值差异性较大。结果显示600s/mm2是MRIDWI序列显示骶髂关节的最适宜b值,不仅能清晰显示双侧骶髂关节,而且所测得关节旁骨髓的表观弥散系数值精确度较高。

Apparent diffusion coefficient evaluation for secondary changes in the cerebellum of rats after middle cerebral artery occlusion

Supratentorial cerebral infarction can cause functional inhibition of remote regions such as the cerebellum, which may be relevant to diaschisis. This phenomenon is often analyzed using positron emission tomography and single photon emission CT. However, these methods are expensive and radioactive. Thus, the present study quantified the changes of infarction core and remote regions after unilateral middle cerebral artery occlusion using apparent diffusion coefficient values. Diffu- sion-weighted imaging showed that the area of infarction core gradually increased to involve the cerebral cortex with increasing infarction time. Diffusion weighted imaging signals were initially in- creased and then stabilized by 24 hours. With increasing infarction time, the apparent diffusion co- efficient value in the infarction core and remote bilateral cerebellum both gradually decreased, and then slightly increased 3-24 hours after infarction. Apparent diffusion coefficient values at remote regions （cerebellum） varied along with the change of supratentorial infarction core, suggesting that the phenomenon of diaschisis existed at the remote regions. Thus, apparent diffusion coefficient values and diffusion weighted imaging can be used to detect early diaschisis.

Metformin inhibits food intake and neuropeptide Y gene expression in the hypothalamus

Metformin may reduce food intake and body weight, but the anorexigenic effects of metformin are still poorly understood. In this study, Sprague-Dawley rats were administered a single intracere- broventricular dose of metformin and compound C, in a broader attempt to investigate the regula- tory effects of metformin on food intake and to explore the possible mechanism. Results showed that central administration of metformin significantly reduced food intake and body weight gain, par- ticularly after 4 hours. A reduction of neuropeptide Y expression and induction of AMP-activated protein kinase phosphorylation in the hypothalamus were also observed 4 hours after metformin administration, which could be reversed by compound C, a commonly-used antagonist of AMP-activated protein kinase. Furthermore, metformin also improved lipid metabolism by reducing plasma low-density lipoprotein. Our findings suggest that under normal physiological conditions, central regulation of appetite by metformin is related to a decrease in neuropeptide Y gene expres- sion, and that the activation of AMP-activated protein kinase may simply be a response to the anorexigenic effect of metformin.

水质模糊评价中污染因子赋权方法的改进及应用

针对常规的赋权方法及水质评价方法存在的不足，提出了两种改进的污染因子赋权方法，在此基础上应用模糊模式识别方法进行水质评价，得到了满意结果。