检索结果-南通市图书馆

Synthesis of Co-Cr-Mo Fluorapatite Nano-Composite Coatings by Pulsed Laser Deposition for Dental Applications

Materials Sciences and Applications 2017年第2期8卷 135-152页

作者： Osama Khfagi Ntevheleni Thovhogi Dhiro Gihwala Malik Maaza johan andré mars Cape Peninsula University of Technology CPUT Bellville South Africa UNESCO-UNISA African Chair in Nanosciences/Nanotechnology College of Graduate Studies University of South Africa Pretoria South Africa Nanosciences African Network (NANOAFNET) Materials Research Department iThemba LABS-National Research Foundation (NRF) Somerset West South Africa Higher Institute for Medical Professions Ajdabiya Libya

Aim: The study was to fabricate FA nanopowder/Co-Cr-Mo dental alloy nanocomposite using pulsed laser deposition (PLD), and to evaluate bioactivity properties on simulated body fluid. Methods: In this work, the FA nanopowder was prepared by mixing calcium hydroxide (Ca(OH)2), phosphorouspent oxide (P2O5) and calcium fluoride (CaF2) in a planetary high energy ball mill using zirconium vial. Fluorapatite (FA) nanopowder was processed in the form of pellet for pulsed laser deposition process. The Co-Cr-Mo alloy was coated with FA nanopowder which was approximately 35 - 65 nm at various laser energy, pressure and time. The X-ray diffraction (XRD) was used to analyze phase, crystallinity and size distribution of Co-Cr-Mo/FA nanocomposite. The surface analysis was by scanning electron microscopy (SEM), Atomic Force microscopy (AFM) and Energy dispersive spectroscopy (EDS). Results: From the results obtained, It was shown that FA nanopowder deposited on Co-Cr-Mo alloy was stable during 14 days of incubation on simulated body fluid. It was also observed that the FA nanopowder coated on the surface of the alloy was still intact after the deposition process, which indicated the bioactivity and biocompatibility of the material. Conclusions: The fabrication of FA nanocomposite based dental alloys (Co-Cr-Mo) using PLD was done successfully. This was confirmed by various characterization techniques, which included XRD, AFM, SEM and EDS.

关键词： Biocompatibility Cobalt-Chromium-Molybdenum Alloys Dental Alloys Fluorapatite Pulsed Laser Deposition (PLD) Simulated Body Fluid (SBF)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Disturbance Rejection in Space Applications:Problems and Solutions 30th

Disturbance Rejection in Space Applications:Problems and Sol...

引用

第三十届中国控制会议

作者： Enrico Canuto andrés Molano-Jimenez Carlos Perez-Montenegro Politecnico di Torino Dipartimento di Automatica e Informatica Corso Duca degli Abruzzi 2410129 TorinoItaly

ISBN: (纸本)9781457706776

＜正＞In the propulsive phase of planetary landing like mars or Moon when only soft landing is the target,guidance, navigation and control are driven by an Inertial Measurement Unit and a radar altimeter/*** measurements are affected by bias and scale（factor） errors,which are aggravated by the vehicle axis to be tilted with respect to the local vertical for most of the descent trajectory,and by the attitude navigation error cumulated during the ballistic（and aerodynamic） flight after the orbiter *** complementing the Centre-of-Mass dynamics with appropriate disturbance state equations driven by noise vectors,and by estimating noise from the model error,scale errors and bias can be real-time retrieved as disturbance state variables,then eliminated from the tracking errors through disturbance rejection, under convergence conditions and sensor *** same result is proved cannot be achieved under pure feedback control. The result shows a well known fact:bias can only be eliminated by disposing of different sensors.A typical case study is the attitude control of drag-free satellites where fine accelerometers allow to reject wide-band drag torques at the price of the attitude drifting because of the accelerometer *** is cancelled by treating it a disturbance to be estimated by attitude sensors like star *** runs illustrate the results.

关键词： Disturbance rejection Disturbance model Attitude control Planetary landing

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

瑞典水文变化-气候变化影响模拟

引用

AMBIO－人类环境杂志 2004年第4期33卷 207-213页

作者： johan andréasson StenBergstrm Bengt Carlsson L.Phil Graham Gran Lindstrm 王纲胜瑞典气象水文研究所(SMHI) 瑞典气象水文研究所(SMHI)罗斯比中心

温室效应加剧导致的气候变化将会引起水文系统的变化。随着气候要素的变化,水文变化将会在全球呈现出区域差异性。因此,有必要开展局地和区域尺度上的水文变化影响研究,评价不同区域将会受到怎样的影响。本研究旨在对广泛的瑞典流域上... 详细信息

温室效应加剧导致的气候变化将会引起水文系统的变化。随着气候要素的变化,水文变化将会在全球呈现出区域差异性。因此,有必要开展局地和区域尺度上的水文变化影响研究,评价不同区域将会受到怎样的影响。本研究旨在对广泛的瑞典流域上气候变化的水文影响(响应)进行评估。我们采用不同的方法,将气候模型中产生的气候变化信号转换输入到水文模型中。利用瑞典区域气候模拟计划(SWECLIM)生成的区域气候情景,我们进行了几次水文模型模拟研究。得出的基本结论是:根据流域的地理位置处于瑞典北部或南部,气候变化对河道水流的分区影响是显著不同的。此外,预测的水文变化不仅与用于确定区域气候模型边界条件的全球气候模型的选择有关,而且与人为气体排放情景的选取有关。

关键词：气候变化水文模型区域气候模拟全球气候气候模型气候要素水文影响瑞典区域差异计划

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Multiple-Organ Extracorporeal Support Therapies in Critically Ill Patients

引用

Open Journal of Nephrology 2021年第2期11卷 281-293页

作者： José Lucas Daza María C. Correcha Ferro andrés David Cardenas Luis Daza Emilio Rey Jonathan de Jong John Galindo Gerardo Gutiérrez Luis Puello Yaroslad de la Cruz Nephrology Unit Hospital De Clinicas Buenos Aires Argentina Department of Medicine Manizales University Manizales Colombia Department of Medicine Cooperativa University Ibague Colombia Hematolology Unit Fluminense University Rio de Janeiro Brasil Nephrology Unit Fresenius Medical Care Ibague Colombia

The critically ill patient is capable of presenting a multiple organ dysfunction syndrome (MODS) caused by different diseases, which can be infectious (sepsis, septic shock) as well as non-infectious (pancreatitis, large surgeries, traumatic injuries, burn patients and brain injuries), this syndrome is characterized by global hemodynamic and organ perfusion alterations accompanied by an uncontrolled and marked inflammatory response unresponsive to pharmacological treatment due to which extracorporeal organ support can be a viable option. Acute renal lesion can occur in up to 60% of patients receiving intensive care, and close to 10% - 20% require renal replacement therapy (RRT) globally this can be provided as peritoneal dialysis (PD) or intermittent hemodialysis (IHD), continuous renal replacement therapy (CRRT), hybrid therapies known as sustained slow efficiency dialysis (SLED), which combines the benefits IHD and CRRT, slow continuous ultrafiltration (SCUF). Extracorporeal membrane oxygenation (ECMO) and extracorporeal elimination of CO2, have been used more frequently lately, these are temporal artificial support used for respiratory and/or cardiac insufficiency that is refractory to conventional treatment. Acute liver failure in adults has a mortality rate close to 50% furthermore one-third of patients hospitalized for cirrhosis are likely to progress to acute liver failure which will drastically increase its mortality. Based on concepts of albumin dialysis, one of its most known is the following: Molecular Adsorbent Recirculating System (mars), Fractionated Plasma Separation and Absorption—FPSA (Prometheus®) and also, hemoperfusion with different cartridges used in different extracorporeal therapies, used in liver failure, rhabdomyolysis, cytokine release syndrome and more in the context of the pandemic covid19. The objective of this review is to know the different extracorporeal therapies and the therapeutic utility in critical patients

关键词： MODS (Multiple Organ Dysfunction Syndrome) RRT (Renal Replacement Therapy CRRT (Continuous Renal Replacement Therapy) SLED (Slow Efficiency Dialysis ECMO (Extracorporeal Membrane Oxygenation) ECCO2 (Extracorporeal Elimination of Carbon Dioxide) ARDS (Acute Respiratory Distress Syndrome) AKI (Acute Kidney Injury)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

行星着陆——推进下降过程的建模与控制(英文)

引用

中国科学技术大学学报 2013年第1期43卷 1-14页

作者： Canuto Enrico Molano-Jimenez andres Perez-Montenegro Carlos Malan Stefano Martella Paolo 都灵理工大学自动化与电子信息科学系意大利都灵10129 阿莱尼亚航天公司 Strada Antica di Collegno 253意大利都灵10135

登陆火星或月球时,释放降落伞后进入推进阶段,通过轴向推力倾斜实现水平方向运动,能够与速度矢量(重力)的相反方向一致或与需要的加速度方向保持一致.后一种策略能实现精确着陆,在该策略下,倾斜角(俯仰角和偏转角)与水平加速度成正比.... 详细信息

登陆火星或月球时,释放降落伞后进入推进阶段,通过轴向推力倾斜实现水平方向运动,能够与速度矢量(重力)的相反方向一致或与需要的加速度方向保持一致.后一种策略能实现精确着陆,在该策略下,倾斜角(俯仰角和偏转角)与水平加速度成正比.这种策略并未采用以水平加速度为姿态控制目标的递阶导航与控制方案,而是基于角加速度对位置作用的四阶动力学特性设计了一个独特的控制系统.除去倾斜角的非线性因素(垂直制动规定的轴向推力)后,系统综合动力学方程能够实现(准)输入-状态线性化.论文同时表明:一方面,基于参考轨迹(倾斜角和位置)的控制器设计仅能实现部分输入-状态线性化;另一方面,系统的内部稳定性可以证明.即使存在不可镇定的外部干扰动力学模态时,仍能确保系统稳定性.蒙特卡洛仿真验证了闭环控制策略的有效性.

关键词：行星着陆有动力下降闭环控制姿态控制位置控制

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：