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GO-modified flexible polymer nanocomposites fabricated via 3D stereolithography

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Frontiers of Chemical Science and Engineering 2019年第4期13卷 736-743页

作者： Chi Him Alpha Tsang Adilet Zhakeyev dennis Y.C.Leung Jin Xuan School of Environmental Sciences and Engineering Sun Yat-Sen UniversityGuangzhou 510006China Department of Mechanical Engineering The University of Hong KongHong KongChina Department of Chemical Engineering Loughborough UniversityLoughboroughLE113TUUK

Graphene oxide(GO)induced enhancement of elastomer properties showed a great deal of potential in recent years,but it is still limited by the barrier of the complicated synthesis ***(SLA),used in fabrication of thermosets and very recently in“flexible”polymers with elastomeric properties,presents itself as simple and user-friendly method for integration of GO into *** this work,it was first time demonstrated that GO loadings can be incorporated into commercial flexible photopolymer resins to successfully fabricate GO/elastomer nanocomposites via readily accessible,consumer-oriented SLA *** material properties of the resulting polymer was characterized and *** mechanical strength,stiffness,and the elongation of the resulting polymer decreased with the addition of *** thermal properties were also adversely affected upon the increase in the GO content based on differential scanning calorimetry and thermogravimetric analysis *** was proposed that the GO agglomerates within the 3D printed composites,can result in significant change in both mechanical and thermal properties of the resulting *** study demonstrated the possibility for the development of the GO/elastomer nanocomposites after the optimization of the GO/“Hexible”photoreactive resin formulation for SLA with suitable annealing process of the composite in future.

关键词： graphene oxide polymer flexible 3D printing stereolithography

Evaluation of cable tension sensors of FAST reflector from the perspective of EMI

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High Technology Letters 2016年第2期22卷 135-141页

作者：朱明 Wang Qiming dennis Egan Wu Mingchang Sun Xiao National Astronomical Observatories Chinese Academy of SciencesBeijing 100012P.R.China National Radio Astronomy Observatory PO Box 2Green BankWV 24944USA

The active reflector of FAST （ five-hundred-meter aperture spherical radio telescope） is suppor- ted by a ring beam and a cable-net structure, in which nodes are actively controlled to form series of real-time paraboloids. To ensure the security and stability of the supporting structure, tension must be monitored for some typical cables. Considering the stringent requirements in accuracy and long- term stability, magnetic flux sensor, vibrating wire strain gauge and fiber bragg grating strain gauge are screened for the cable tension monitoring of the supporting cable-net. Specifically, receivers of radio telescopes have strict restriction on electro magnetic interference （EMI） or radio frequency in- terference （RFI）. These three types of sensors are evaluated from the view of EMIfRFI. Firstly, these fundamentals are theoretically analyzed. Secondly, typical sensor signals are collected in the time and analyzed in the frequency domain, which shows the characteristic in the frequency domain. Finally, typical sensors are tested in an anechoic chamber to get the EMI levels. Theoretical analysis shows that Fiber Bragg Grating strain gauge itself will not lead to EMI/RFI. According to GJB151 A, frequency domain analysis and test results show that for the vibrating wire strain gauge and magnetic flux sensor themselves, testable EMIfRF1 levels are typically below the background noise of the ane- choic chamber. FAST finally choses these three sensors as the monitoring sensors of its cable ten- sion. The proposed study is also a reference to the monitoring equipment selection of other radio tele- scopes and large structures.

关键词： five-hundred-meter aperture spherical radio telescope (FAST) cable tension mo-nitoring magnetic flux vibrating wire fiber Bragg electro magnetic interference (EMI)

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一种能实现单频PPP-RTK的GNSS局域参考网数据处理算法

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地球物理学报 2015年第7期58卷 2306-2319页

作者：张宝成 ODIJK dennis 中国科学院测量与地球物理研究所动力大地测量学国家重点实验室武汉430077 GNSS Research Centre Department of Spatial SciencesCurtin University

全球范围内大量布设的GNSS（Global Navigation Satellite System）参考网为精密定位、导航和授时等应用提供了丰富的数据资源.基于局域参考网,先后发展了若干侧重实现双频精密定位的技术,如NRTK（Network Real Time Kinematic）,PPP（P... 详细信息

全球范围内大量布设的GNSS（Global Navigation Satellite System）参考网为精密定位、导航和授时等应用提供了丰富的数据资源.基于局域参考网,先后发展了若干侧重实现双频精密定位的技术,如NRTK（Network Real Time Kinematic）,PPP（Precise Point Positioning）和PPP-RTK等.其中,PPP-RTK融合了NRTK和PPP的技术优势,是目前相关研究的热点.本文改进了利用局域参考网提取各类改正信息的算法,以便于实现单频PPP-RTK,具体步骤包括：1）逐参考站实施非组合PPP,并固定已知站星距和卫星钟差,预估电离层延迟、浮点模糊度等参数;2）联合所有参考站的PPP模糊度预估值,通过重新参数化,形成一组双差整周模糊度和接收机、卫星相位偏差;3）固定双差整周模糊度,精化求解卫星相位偏差和各参考站PPP电离层延迟.基于网解中用到的卫星轨道和钟差,以及网解所提供的卫星相位偏差和（内插的）电离层延迟,参考网内的单频流动站即可实施PPP-RTK.基于澳大利亚某连续运行参考站网和流动站的实测数据,考察了：1）参考网数据处理中,双差模糊度的固定成功率（98.89%）和卫星相位偏差估值的时间稳定性（各连续弧段优于0.2周）;2）流动站处电离层延迟的内插精度（优于10cm）;3）单天内任一历元起算,固定静态（动态）单频PPP整周模糊度所需时长（均不超过10min）;4）模糊度固定前后,单频动态PPP的定位精度（模糊度固定后,平面和天顶RMS分别优于5cm和10cm;模糊度固定前,相应RMS仅为28～53cm）.

关键词：单频PPP-RTK 卫星相位偏差电离层延迟整周模糊度固定

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Neonatal Direct Rigid Laryngoscopy and Bronchoscopy: A Near Miss

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Antitumor immunity induced by the photodynamic action of BAM-SiPc,a silicon(IV)phthalocyanine photosensitizer

Open Journal of Anesthesiology（麻醉学期刊） 2024年第4期 126页

作者： dennis E.Feierman Mark Kronenfeld Jacob Sutton Gil Zoizner Evan P.Salant

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Cellular & Molecular Immunology 2019年第7期16卷 676-678页

作者： Ying Zhang dennis K.P.Ng Wing-Ping Fong School of Life Sciences The Chinese University of Hong KongHong KongChina Department of Chemistry The Chinese University of Hong KongHong KongChina

Photodynamic therapy(PDT)is a promising approach to treat cancer.1 It involves the use of three individually nontoxic substances to produce a toxic effect.A photosensitizer,when illuminated with light of an appropriate wavelength,will be activated and convert molecular oxygen into reactive oxygen species(ROS),which can then kill tumor *** success of PDT depends on its potency as well as the targeting of the photosensitizer to the tumor site.2 For example,in photoimmunotherapy,the photosensitizer is conjugated to monoclonal antibodies that direct the photosensitizer to tumor cells that express the specific antigen recognized by the antibodies,and the tumor cells are killed upon light irradiation of the tumor site.3 This direct cytotoxicity is useful in treating localized tumor;however,it has limited applicability when metastasis *** this regard,the activation of antitumor immunity appears to be more promising because most cancer patients die,not from localized tumor,but from cancer metastasis and relapse.

关键词： immunity metastasis cancer

On the origin of microbial magnetoreception

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National Science Review 2020年第2期7卷 472-479页

作者： Wei Lin Joseph L.Kirschvink Greig A.Paterson dennis A.Bazylinski Yongxin Pan Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Institutions of Earth Science Chinese Academy of Sciences France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicellular Organisms Chinese Academy of Sciences Division of Geological & Planetary Sciences California Institute of Technology Earth-Life Science Institute Tokyo Institute of Technology Department of Earth Ocean and Ecological Sciences University of Liverpool School of Life Sciences University of Nevada at Las Vegas College of Earth and Planetary Sciences University of Chinese Academy of Sciences

A broad range of organisms, from prokaryotes to higher animals, have the ability to sense and utilize Earth’s geomagnetic field—a behavior known as magnetoreception. Although our knowledge of the physiological mechanisms of magnetoreception has increased substantially over recent decades, the origin of this behavior remains a fundamental question in evolutionary biology. Despite this, there is growing evidence that magnetic iron mineral biosynthesis by prokaryotes may represent the earliest form of biogenic magnetic sensors on Earth. Here, we integrate new data from microbiology, geology and nanotechnology, and propose that initial biomineralization of intracellular iron nanoparticles in early life evolved as a mechanism for mitigating the toxicity of reactive oxygen species(ROS), as ultraviolet radiation and free-iron-generated ROS would have been a major environmental challenge for life on early Earth. This iron-based system could have later been co-opted as a magnetic sensor for magnetoreception in microorganisms, suggesting an origin of microbial magnetoreception as the result of the evolutionary process of exaptation.

关键词： magnetoreception biomineralization magnetotactic bacteria exaptation

Aluminum-air battery with cotton substrate:Controlling the discharge capacity by electrolyte pre-deposition

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Green Energy & Environment 2023年第3期8卷 757-766页

作者： Wending Pan Yifei Wang Holly Y.H.Kwok dennis Y.C.Leung Department of Mechanical Engineering The University of Hong KongHong KongChina

Conventional Al-air battery has many disadvantages for miniwatt applications,such as the complex water management,bulky electrolyte storage and potential leakage ***,the self-corrosion of Al anode continues even when the electrolyte flow is stopped,leading to great Al *** tackle these issues,an innovative cotton-based aluminum-air battery is developed in this *** of flowing alkaline solution,cotton substrate pre-deposited with solid alkaline is used,together with a small water reservoir to continuously wet the cotton and dissolve the alkaline *** this manner,the battery can be mechanically recharged by replacing the cotton substrate and refilling the water reservoir,while the thick aluminum anode can be reused for tens of times until complete *** cotton substrate shows excellent ability for the storage and transportation of alkaline electrolyte,leading to a high peak power density of 73 mW cm^(-2) and a high specific energy of 930 mW h g^(-1).Moreover,the battery discharge capacity is found to be linear to the loading of pre-deposited alkaline,so that it can be precisely controlled according to the mission profile to avoid Al ***,a two-cell battery pack with common water reservoir is developed,which can provide a voltage of 2.7 V and a power output of 223.8 *** further scaling-up and stacking,this cotton-based Al-air battery system with low cost and high energy density is very promising for recharging miniwatt electronics in the outdoor environment.

关键词： Al-air battery Cotton-based Electrolyte pre-deposition Capacity control Miniwatt electronics

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A Video Store Application Design and Implementation Using JAVA Servlet, JSP and SQL Server

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A Video Store Application Design and Implementation Using JA...

作者： dennis Gitari Njagi 中南大学

学位级别：硕士

电子商务(E-commerce)是使用电子技术进行商业活动的过程。本课题主要讨论在线视频信息系统的设计和实现。客户可以根据喜好搜索视频产品、浏览产品详细信息以及购买它们。购买过程是通过获取用户的信用卡信息和地址来实现的。上述功能... 详细信息

电子商务(E-commerce)是使用电子技术进行商业活动的过程。本课题主要讨论在线视频信息系统的设计和实现。客户可以根据喜好搜索视频产品、浏览产品详细信息以及购买它们。购买过程是通过获取用户的信用卡信息和地址来实现的。上述功能必须能够通过任何web客户端访问。在从信用卡中扣除了费用以后商店工作人员将会把商品邮寄给用户。这一系统是自动的,并且可以帮助公司提高管理和订单分发的效率。这里使用了一个叫“Generations Video Store” 的虚拟公司来表示一个典型企业的信息需求。本系统采用MVC(Model VieW Controuer)设计模式进行设计与实现,而所使用的Java技术主要是Java servletS,JSP(Java Server Pages)和Javabeans。本文首先介绍了我们的系统的背景,随后介绍了MVC体系结构。接下来进行需求定义和分析,用到了Kozar需求模型、PIECES等框架。本系统体系中同样也考虑了会话和安全性需求,例如,会话跟踪,Java安全性,SSL(Secure Socket Layer 安全套接字层)和数据库安全性。本系统中所必需的数据表使用作为后台数据库的SQL Server2000来进行设计。另外与JDBC有关的连接缓冲池也是一个着重考虑的问题。接下来是基于MVC体系结构的系统界面设计和实现。本文中给出了部分界面截图,并说明了MVC体系结构中Java servlets、JSP页面和Javabeans之间的交互。最后通过分析系统的不足和开发过程中碰到的问题对整个项目进行了总结,同时给出了若干改进的建议。

关键词： MVC体系结构电子商务 JSP(Java Server Pages) JavaBeans

Routing Protocol for Low Power Lossy Wireless Sensor Networks

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Routing Protocol for Low Power Lossy Wireless Sensor Network...

作者： dennis Owiti Miyare 华南理工大学

学位级别：硕士

A wireless sensor network（WSN）is made up of several sensor nodes and each node is equipped with a radio transceiver,a microcontroller and an energy *** usually run on batteries and this imposes a constraint on the lifespan of a node and in turn the entire *** the name suggests,a sensor collects data,communicating this collected data is the most expensive action it performs in terms of power *** thesis evaluates a network protocol that implements measures to reduce energy consumption in Wireless Sensor Networks,measures such as dynamic sending rate of control messages and addressing topology inconsistencies only when data packets have to be sent,Routing Protocol for Low power Lossy *** aims to prove that the protocol will allow the nodes to discover each other,conserve the system resources such as energy and memory,minimize data loss between the nodes and establish efficient routes for data to flow through the *** based on Ipv6 the protocol should also do away with non-interoperable networks interconnected by protocol translation gateways and proxies and transition to an end-to-end IP-based *** simulating the operation of the protocol in a lab environment we proved the effectiveness and efficiency of the proposed scheme by a comprehensive qualitative analysis of its ability to save energy by finding the shortest possible route to minimize transmission energy

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