oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 131 )

2018 ( 2971 )

2017 ( 3067 )

2016 ( 3314 )

Custom range...

Search Results: 1 - 10 of 132087 matches for " ?杨岩岩 "
All listed articles are free for downloading (OA Articles)
Page 1 /132087
Display every page Item
饮料中有机酸和无机离子的离子色谱测定法
,更生
色谱 , 1990,
Abstract: 离子色谱是一项对水溶液的电离物质色谱分析的技术,从70年代中期以来,这项技术运用愈来愈广泛,特别在食品分析方面有很快的发展。 有机酸和无机酸在碱性条件呈阴离子状态,往往可以用离子色谱法检测,但由于不
双曲柄四环板式针摆行星减速器减振降噪研究
,
兵工学报 , 2011,
Abstract: ?双曲柄四环板式针摆行星减速器是一种新型环式摆线针轮减速器,在实验中发现,减速器在运转时产生较大的振动和噪声,在一定程度上影响了其推广和应用。以三齿轮联动双曲柄四环板式针摆行星减速器为研究对象,运用Artemis集成化多通道声与振动分析系统对其进行不同工况下的振动与噪声测试,进而分析了减速器主要部件的振动噪声特性,识别出减速器内部主要噪声源为摆线轮和针轮啮合时产生的噪声。针对该噪声源和减速器箱体分别提出相应的改进方案,并对改进后的减速器再次进行测试与分析。结果表明,减速器箱体的结构改进和针摆齿轮传动比的改变有效地降低了该减速器的振动与噪声。该研究结果为双曲柄四环板式针摆行星减速器的减振降噪设计提供了依据。
门冬氨酸鸟氨酸治疗慢性肝炎中、重度黄疸疗效观察
焦运,
宁夏医科大学学报 , 2008,
Abstract: 为观察门冬氨酸、鸟氨酸治疗慢性肝炎中、重度黄疸的临床疗效,选择146例慢性肝炎中、重度黄疸患者(其中合并肝性脑病者42例)分为治疗组(给予门冬氨酸鸟氨酸10g治疗,合并肝性脑病者20g);对照组(给予舒肝宁20mL,合并肝性脑病者给予左旋多巴300mg),比较两种药物退黄效果及患者神志改善情况。结果,治疗组中、重度黄疸患者治疗后SB明显低于对照组,差异有统计学意义(P<0.05,或P<0.01)。治疗组肝性脑病患者治疗有效率高于对照组(χ2=5.47,P<0.05)。治疗后治疗组ALT明显低于对照组(P<0.05),PTA明显高于对照组(P<0.05)。门冬氨酸鸟氨酸治疗慢性肝炎消退黄疸及肝性脑病效果确切。更多还原
环境激励下古建筑木结构模态参数识别与分析
,
武汉理工大学学报 , 2010,
Abstract: ?结构的模态参数识别是结构健康监测的重要内容,对结构的状态评估与损伤识别具有重要意义,对于古建筑木结构亦是如此。利用在典型藏式古建筑木结构中布设的加速度动力特性监测系统,获得所监测结构在人群荷载等环境随机激励下的振动响应数据,采用随机减量法与itd法相结合的方法对加速度信号在时域内进行结构模态参数识别,获取监测结构的动力特性参数。分析结果表明,该方法可以在环境激励下有效的识别结构的模态频率与阻尼比。结合监测传感器所采集的数据,利用matlab工具箱函数建立人工神经网络,分析人群分布区域、密度、行走频率等因素对结构动力特性参数识别精确度的影响,并在此基础上对监测结构的动力响应进行预测,为该藏式古建筑木结构的结构状态评估提供必要的数据支持。?
腔镜联合术式对行全子宫切除术患者手术相关指标、疼痛程度及术后并发症的影响
,
- , 2018, DOI: 10.3969/j.issn.1007-1989.2018.08.013
Abstract: 摘要: 摘要:目的??探讨腔镜联合术式对行全子宫切除术患者手术相关指标、疼痛程度及术后并发症的影响。方法?研究对象选取该院2014年5月-2017年5月收治的行全子宫切除术的患者共80例,采用随机数字表法分为对照组(40例)和观察组(40例),分别行腹腔镜辅助阴式全子宫切除术式和腔镜联合术式治疗;比较两组患者手术操作时间、术中失血量、尿管拔除所需时间、总住院时间、术后6、12及24?h视觉模拟评分(VAS)和术后并发症发生情况。结果?两组手术操作时间和术中失血量比较差异无统计学意义(P?>0.05);观察组尿管拔除所需时间和总住院时间均明显短于对照组(P?<0.05);观察组术后VAS评分均明显低于对照组(P?<0.05);观察组术后并发症发生率明显低于对照组(P?<0.05)。结论?腔镜联合术式下行全子宫切除术可有效缩短术后康复所需进程,缓解机体疼痛,并有助于预防术后并发症发生,价值优于腹腔镜辅助阴式全子宫切除术式。
Abstract: Abstract: Objective?To investigate the influence of combined endoscopic surgery scheme on the level of operation-related indexes, pain degree and postoperative complications of patients underwent total hysterectomy.?Methods?80 patients underwent total hysterectomy were chosen from May 2014 to May 2017 and randomly divided into two groups including control group (40 patients) with LAVH surgery scheme and observation group (40 patients) with combined endoscopic surgery. Then the operation time, the amount of blood loss, the catheter removal time after operation, the total hospital staying time, the VAS score in 6?h, 12?h and 24?h after operation and postoperative complications incidence of the two groups were compared.?Results?There was no significant difference in the operation time and the amount of blood loss between the two groups (P?>?0.05). The catheter removal time after operation and the total hospital staying time of observation group were significant shorter than that in control group (P?
碳纤维增强木基复合材料的制备及其力学性能
The Preparation and Mechanical Properties of Wood-based Composite Materials Reinforced by Carbon Fiber

,
- , 2015, DOI: doi:10.3969/j.issn.1001-7461.2015.06.42
Abstract: 为了研究碳纤维增强木基复合材料的力学性能,选择直径为12 μm的碳纤维制备试样。分别对碳纤维增强木基复合材料与木纤维板进行了三点弯曲力学性能测试,运用扫描电镜(SEM)对其微观结构进行表征。结果表明:通过力学曲线对比及断裂机理分析,可以明显的发现碳纤维增强木基复合材料的力学性能要优于木纤维板,这种“三明治”结构的材料设计充分发挥出碳纤维独特的缓冲能力,试件在较高外加载荷作用下并不是产生突然的断裂破坏,而是具有一定的承载能力。SEM分析表明,聚醋酸乙烯胶粘剂工作强度高,在受力时能够很好的传递载荷,碳纤维网与木纤维板结合良好。
In order to study the mechanical properties of wood-based composite materials reinforced by carbon fiber, the paper selected the carbon fibers with a diameter of 12 μm to prepare test specimens. The three-point bending mechanical tests were taken respectively between the wood-based composite materials reinforced by fiberglass and the wood fiberboard. The three-point bending mechanical tests were taken respectively between the wood-based composite materials reinforced by carbon fiber and the wood fiberboard, which was used to characterize its microstructure by scanning electron microscopy (SEM). It could obviously discover that the mechanical properties of wood-based composite materials reinforced by carbon fiber were superior to wood fiberboard’s by the comparison of mechanics curve and the analysis of fracture mechanism. The design of the material with this “sandwich” structure fully reflected the unique buffering capacity of fiberglass, so the specimen at high applied loads did not produce a sudden fracture failure, however it had a certain carrying capacity. The SEM analysis demonstrated that polyvinyl acetate adhesives had high work intensity. When stressed, it could be a good transfer loads to make good combination with carbon fiber mesh and wood fiberboard
线性回归模型中响应值的选取对二分类问题的影响
The Effects of Different Response Values in Linear Regression Model on Binary Classification
 [PDF]

王小英, , 陈常龙
Statistics and Applications (SA) , 2015, DOI: 10.12677/SA.2015.42007
Abstract:
我们利用多元线性回归模型处理两个总体的分类问题,首先对响应变量按一定的规则赋值,并在最小二乘法的基础上构建判别函数及判别准则,进而论证了响应值的选取对平衡及不平衡数据二分类问题的影响。此外,我们将此判别方法与经典判别分析方法如:经典马氏距离判别法、Bayes判别法进行比较,并得到它们之间的内在联系及优缺点。
We use the multiple linear regression model to deal with the classification problem of two popula-tions. Firstly, we assign the response variables and some corresponding values with certain rules, and then construct discriminant function and criterion via least square method. On this basis, we discuss the effects of different response values on classification for balanced and unbalanced data in linear model. In addition, we compare the mentioned discriminant method above with classic discriminant methods including the classical Mahalanobis distance discriminant and Bayes dis-criminant. At last, we find the inner relation between these methods as well as their advantages and disadvantages.
信息技术在智能办公大厦中的应用
,亮兴
计算机系统应用 , 1993,
Abstract: 现代信息技术文化(in formation technology culture)赋于传统建筑物以智能,从而构成智能建筑系统。本文 分析了该系统的结构和功能,并论述了智能办公大厦的基本特征及应用前景。
ENU诱导点突变——大规模基因突变和功能研究
,
生物工程学报 , 2001,
Abstract: ENU诱导点突变正在成为一种大规模基因功能研究的有效手段。这里介绍了ENU诱变的机制、影响诱变效率的因素、ENU诱变的策略、表型的筛选、点突变的鉴定以及相关的研究和取得的一些最新进展。
8.0kaB.P.以来三江平原北部沼泽发育和古环境演变研究
永兴,王世
地理科学 , 2003,
Abstract: 8.0kaB.P.以来,三江平原北部气候变化序列划分为5个阶段,温暖湿润(8000~5590aB.P.)→较温暖湿润(5590~1851aB.P.)→温冷稍湿(1851~1110aB.P.)→寒冷偏湿(1110~649aB.P.)→冷凉略湿(649aB.P.~至今)。气候的变化模式依次为高温期→温暖适宜期→缓慢降温期→急剧降温期→低温渐暖期。在5590aB.P.和1317aB.P.,发生强烈降温事件。沼泽发育也依次划分为5个时期,沼泽化过程发展期→沼泽大发展期→沼泽发育缓慢期→沼泽发育波动期→沼泽发育萎缩期。植被演替相应为温性阔叶林→针、阔叶混交林和草原→以落叶阔叶树稍多的针、阔叶混交林和草原→以桦为主的阔叶林→针阔混交林、以松占优势的针、阔叶混交林和草原。在1851~1317aB.P.、649~309aB.P.和309~0aB.P.期间,受频繁的农业生产、砍伐森林、开垦沼泽为农田等人类活动的影响,沼泽发育呈现退化的趋势。
Page 1 /132087
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.