基于Logistic模型的P2P资源流行程度分析

为了解决目标资源数量增多而带来的监管成本过高的问题,提出一种基于Logistic模型的资源流行程度分析方法.利用该方法估计目标资源的流行程度,剔除流行程度低的资源,以此缩小监控范围,减少节点的部署数量.在Kad中对不同资源进行追踪,统计资源的共享节点数量,估计Logistic模型的参数,并进行曲线拟合.通过决策树建模得出,资源的共享节点数量和资源大小是影响该方法准确性的关键因素.     

金属多面体上低剖面天线的矩量法分析

采用矩量法对任意形状导体上的低剖面天线进行了整体分析,其中导体采用三角形面元矢量基函数、细线结构采用三角形基函数、线面连接处采用特殊的基函数,在处理积分奇异时,通过坐标变换、积分转化、降维处理实现了奇异积分的精确快速计算,以平板单极子天线为例,验证了该方法的有效性.最后,利用该方法对金属立方体上的低剖面电小环天线特性进行了分析,得出的结论对设计复杂载体上低剖面天线或天线阵有一定的参考价值。     

Upregulation of miR145 and miR126 in EVs from Renal Cells Undergoing EMT and Urine of Diabetic Nephropathy Patients

Simple SummaryDiabetic nephropathy is one of the most frequent complications of diabetes, resulting from diffuse damage to different kidney cells. The identification of subjects at risk is mandatory to prevent its development and provide appropriate therapies reducing the unmanageable evolution towards end-stage kidney disease. The aim of this work was to identify urinary-derived extracellular vesicles (EVs) miRNA cargo to be used as biomarker of kidney damage in diabetic patients. The miRNA profile was then correlated with the molecular mechanism associated with the glomerular and tubular damage using a diabetic-like model. In patients, miR145 and miR126 in urinary EVs increased together with albuminuria. MiR145 and miR126 increased in parallel in EVs from renal epithelial cells undergoing transition to a fibrotic mesenchymal phenotype. These data unveiled a role for miR126 and miR145 as the biomarkers of damage progression and proteinuria development in diabetic nephropathy. AbstractDiabetic nephropathy (DN) is a severe kidney-related complication of type 1 and type 2 diabetes and the most frequent cause of end-stage kidney disease. Extracellular vesicles (EVs) present in the urine mainly derive from the cells of the nephron, thus representing an interesting tool mirroring the kidney’s physiological state. In search of the biomarkers of disease progression, we here assessed a panel of urinary EV miRNAs previously related to DN in type 2 diabetic patients stratified based on proteinuria levels. We found that during DN progression, miR145 and miR126 specifically increased in urinary EVs from diabetic patients together with albuminuria. In vitro, miRNA modulation was assessed in a model of TGF-β1-induced glomerular damage within a three-dimensional perfusion system, as well as in a model of tubular damage induced by albumin and glucose overload. Both renal tubular cells and podocytes undergoing epithelial to mesenchymal transition released EVs containing increased miR145 and miR126 levels. At the same time, miR126 levels were reduced in EVs released by glomerular endothelial cells. This work highlights a modulation of miR126 and miR145 during the progression of kidney damage in diabetes as biomarkers of epithelial to mesenchymal transition.     

中国煤矿粉尘危害防治技术现状及发展方向

为了解决煤矿综掘工作面粉尘污染难题,以唐口煤矿3110运输巷综掘工作面为研究对象,对压抽风量比r为0.5、0.8、1.2、1.5条件下的多径向涡旋气幕运移及其阻尘效果开展数值模拟研究。结果表明,随着r的减小,控制风流结构的主要因素由惯性转变为抽风负压,气幕保持径向涡旋状态的轴向运移距离及其前部低速紊流区均随之减小,当r减小至0.8及0.5时,能够在掘进作业区域形成轴向阻尘流场,粉尘污染范围也随之减小。结合综掘工作面实际情况,选取r为0.8,经现场应用,掘进机司机前部断面形成了较为完整的轴向阻尘流场,风速减小至0.38~1.19 m/s,掘进机司机处粉尘质量浓度降至63.0 mg/m³。

     

超长综采工作面撤架期间煤自燃预测及防控技术研究

大兴煤矿北一202工作面采用超长开切眼布置,存在采空区空间大、开采易自燃煤层、工作面全程俯采且顶板存在复合煤岩层采空区遗煤量大等因素,导致工作面防灭火工作难度大幅提高。通过在工作面进、回风巷道,以及上、下隅角向工作面70 m处架后采空区预埋4个束管测点,对北一202超长俯采工作面采空区自燃“三带”分布范围进行多点位观测,得出超长俯采工作面采空区最大氧化带宽度为37.7 m,位于上隅角向工作面70 m架后采空区。根据北一202工作面实际参数,建立三维几何模型,通过Fluent数值模拟分析,揭示了超长俯采工作面采空区流场及O₂体积分数变化规律,并将采空区自燃“三带”分布范围模拟结果与实测结果进行对比,发现两者基本一致,证明了采用数值模拟方法分析研究超长俯采工作面采空区流场、O₂体积分数分布规律的有效性和科学性。

     

微波法辅助提取葡萄叶白藜芦醇及其纯化研究

以新疆南部巴州地区赤霞珠葡萄叶为原料,采用微波辅助法提取葡萄叶中的白藜芦醇,并NKA-Ⅱ树脂进行纯化。实验表明:微波辅助法提取葡萄叶白藜芦醇的最佳工艺条件为:乙醇浓度40%,微波功率640 W,时间76 s,料液比1∶92,在此条件下提取白藜芦醇为13.52 mg/g;经过静态实验筛选,采用NKA-Ⅱ树脂对白藜芦醇粗品进行纯化,其纯化的最佳工艺参数为:6 BV、浓度3 mg/m L、p H4的白藜芦醇样液以2 BV/h通过树脂,用4倍柱体积90%的乙醇以3BV/h的流速洗脱效果最佳,纯度由35.7352 mg/g提高到了181.5888 mg/g。结论:虽然微波辅助法的提取率不是最高的,但时间短,有利于工业生产,纯化虽然有一定效果,但仍需进一步研究。      

注水替油井提前失效机理探讨

碳酸盐岩油藏注水替油技术在塔河油田推广应用以来,取得了良好的增产效果,但随着注水井和注水量的增加,不同区块的注水井表现出独特的动态特征.油井注水失效后表现出累计注采比远低于区域内其它注水井,注水提前失效,生产效果大幅下降.     

辣木叶中多酚提取的工艺研究

本论文采用热浸提法,以食用酒精为溶剂,考察酒精度数、液料比、D-异抗坏血酸钠用量、提取温度和提取时间对辣木叶多酚提取率的影响,并在单因素实验的基础上,通过响应面实验分析,优化了辣木叶多酚的提取工艺。结果表明,辣木叶多酚的最优提取工艺条件:食用酒精度数为64%vol,液料比为20∶1（m L·g-1）,D-异抗坏血酸钠添加量为0.15‰,提取温度为64℃,提取时间为115 min,在此条件下多酚的得率为3.39%。      

Ti-12Co-5Al合金的β相α+Ti2Co时效相变与硬度

研究了超塑合金Ti-12Co-5Al非平衡态β相α+Ti₂Co共析转变的时效过程以及它的硬度变化。当温度为450℃时,随着时间的增长硬度随之增加,β相的转变也更加完全,转变产物之间以及转变产物与母相之间的相变也从完全共格到半共格再到完全非共格,而峰值发生在320min左右;当时间为20min时,随温度的升高也具有相同的规律,峰值发生在600℃左右。Al元素除了具有固溶强化的作用之外,还有提高共析相变温度,从而减缓了相转变动力学的进行。     

Columnar to Equiaxed Transition During Solidification of Small Ingot by Using Electric Current Pulse

A new approach to applying the electric current pulse (ECP)with parallel electrodes to the promotion of the transition from columnar crystal to equiaxed crystal and the improvement of macrosegregation was introduced. The ECP was applied to different stages of the solidification. The results showed that the application of the ECP in both the initial stage (the thickness of solidified shell reached 2 mm approximately)and the late stage (the thickness of solidified shell reached 14 mm approximately)of solidification can promote the columnar to equiaxed transition (CET). The analysis showed that during solidification, a large number of nuclei around the upper surface fell off due to ECP, which subsequently showered on the melt and impinged the growth front of the columnar crystal. There-fore, the CET occurred. In addition, this method was also employed to influence the solidification process of bearing steel, and the results showed that the structure was changed from columnar crystal to equiaxed crystal, indicating that ECP can enhance the homogeneity of structure and composition of bearing steel.