46 research outputs found

    The Estimation of Submarine Inputs of Groundwater to a Coastal Bay Using Radium Isotopes

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    福建省漳州市隆教湾海水中镭同位素的研究,目的是评价海底地下水排泄量。在2007年6月的航次中,垂直于岸线的9km剖面上布置15个站位,每个站位用潜水泵采集表层海水样60L于塑料桶中。水样运回实验室后,立即用装有锰纤维的PVC管以虹吸的方式富集水样中的镭同位素,水通过PVC管的流速小于300ml/min。224Ra活度用连续射气法测定,测完224Ra后密封7d以上,然后用直接射气法测定226Ra活度。224Ra和226Ra活度都呈现自岸向海逐渐降低的规律,表明扩散控制镭同位素的分布,由224Ra获得68.83km2d-1的扩散系数,同时226Ra形成-0.963dpm100l-1km-1的活度梯度。用扩散系数和活度梯度建立的226Ra的离岸通量为6.62×1011dpmkm-2d-1,这个通量一定是得到SGD输入的镭支持,从而获得隆教湾的海底地下水排泄量是3.03×109m3km-2d-1。该排泄量包括陆源地下淡水排泄量和再循环海水排泄量,绝大部分可能是再循环海水,有待进一步研究。This paper reports the results of initial research on radium isotopes of surface ocean waters in the Longjiao Bay on the western flank of Taiwan Strait. The main objective of this research is to assess the submarine groundwater discharge (SGD). In order to assess the spatial distribution of 224Ra and 226Ra, the authors collected 15 surface ocean water samples (ca. -1 m in depth) during the low tide. The collection was performed within a period of 2 hours in the direction from onshore to 9 km offshore by using 60 L polypropylene buckets. In the laboratory, the water samples were immediately treated through gravity-fed PVC column (4.5 cm in diameter, 50 cm in length), filled with manganese oxide-impregnated acrylic fiber at a flow rate of ~300 ml/min to retain radium. After that, the activities of 224Ra absorbed on the Mn-fiber were measured through the continuous emanation method. Finally, the Mn-fiber was sealed for more than 7 days, and the activities of 226Ra absorbed on the Mn-fiber were measured through the direct emanation method. 226Ra distribution yields an activity gradient of -0.963 dpm100 l-1km-1. The short-lived 224Ra distribution in this region yields an eddy diffusion coefficient of 68.83 km2d-1. The interpretation is that the eddy diffusion is the primary controlling agent for the shore perpendicular distribution of the long-lived 226Ra. In order to estimate the seepage rate of groundwater in the study area, the authors applied the approach developed by Moore. The short-lived radium isotopes, 224Ra, were used to establish the eddy diffusion coefficient for the near-shore study area. The product of the eddy diffusion coefficient and the offshore 226Ra activity gradient established the 226Ra flux of 6.62×1011dpmkm-2d-1. It is expected that this flux must be balanced by Ra input from the submarine groundwater discharge (SGD). On the basis of the flux of SGD within the shore, 226Ra budget was calculated as 3.03×109 m3km-2d-1. This magnitude of SGD includes terrestrially-derived fresh SGD and recirculated seawater SGD, However, further researches should be required to determine the terrestrially-derived fresh SGD on the one hand, and recirculated seawater SGD on the other hand.国家自然科学基金项目(编号:40672166)资

    Application of 5S management method on the materials science & engineering experimental teaching and personnel training

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    将5S管理方法引入材料科学与工程实验室建设与实验教学管理中。通过建立5S推行组织、确定试运行实验室的方法学习5S管理模式,以点带面,建立逐步在整个实验教学中心、在学生培养中推行5S管理的方法。The 5S management method is introduced into material science and engineering laboratory construction and experimental teaching management.By establishing an implementation organization, determining the test run laboratory, the 5S management mode is studied.And then fan out from point to area, it's gradually set up in the whole experiment center.It's also implemented during the personal training of the students in the university.教育部“十二五”国家级实验教学示范中心:厦门大学材料科学与工程专业实验教学示范中心(教高厅函[2012]13号); 教育部卓越工程师教育培养计划:厦门大学材料科学工程(教高厅函[2013]38号); 教育部第二批高等学校特色专业建设点:材料科学与工程(教高函[2007]31号); 福建省本科高校专业综合改革试点:材料科学与工程专业(闽教高[2012]41号

    Construction an Opening Materials Science and Engineering Experimental Platform for all Students in the University

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    厦门大学材料科学与工程实验教学中心是2012年教育部批准建设的国家级专业实验教学示范中心。该实验教学中心针对不同学科、不同层面的学生,开设面向本专业的A类专业实验课程、面向校内相关理工科专业的B类材料基础实验课程以及面向全校各专业的C类材料通识实验课程。通过分层次、分体系的实验课程设置,教学科研协同发展和校企联合培养的实验教学模式,以及智能化管理系统的建设,实现实验室对全校师生的开放,全面提高实验中心的辐射示范作用。Materials science and engineering experimental teaching center of Xiamen University is an national professional teaching demonstration center, which was approved to construct by the education Ministry in 2012. According to the knowledge background and different requirement of the students in the university the experimental teaching center offers three level experimental courses: Course A is for the students in material college, which contains many specialized materials experiments; Course B is for the students major in science and engineering in the university, which contains basic materials experimental courses; Course C is for all students in the university, which contains general study materials experimental courses. Through the three level course settings and relevant teaching methods, as well as a controlled, visualized and intelligent management system, the center orderly opening to the students comes true. It is benefit to improve the role of radiation and demonstration of the center

    高性能SOAP引擎关键技术研究与实现

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    Web服务具有松散耦合,互操行性强和平台无关等特点,是面向服务体系架构SOA的主要实现方式。基于XML的SOAP协议是Web服务的核心协议之一,它是独立于特定编程语言和平台的可扩展消息处理框架,使得Web服务具有良好的互操作性和可扩展性。但是SOAP协议的性能限制了SOAP协议和Web服务在高性能分布式计算环境中的应用。SOAP引擎是支持SOAP协议的Web服务运行支撑环境,SOAP引擎的性能直接决定了Web服务的性能。 本文首先通过分析分布式组件交互模型的演化,指出基于消息的松耦合交互模型是其发展方向,但同时会带来性能的下降。Web服务是支持这种交互模型的典型代表,其网络通信和数据模型映射是影响Web服务性能的关键因素。 在分析结果的基础上,本文提出了一种基于Reactor模式的网络通信模型,通过基于事件驱动的I/O和分治原则,有效地提高了SOAP引擎处理网络通信的性能和可扩展性。 此外,论文提出了一种新的数据模型映射机制-动态提前绑定,通过在运行时动态产生驱动数据模型映射的模板来避免耗时的Java反射操作,由模板实例实现XML数据对象和Java数据对象间的快速映射。 论文将基于Reactor模式的网络通信模型和动态提前绑定技术应用于自主开发的新一代SOAP引擎-SOAPExpress,测试数据表明SOAPExpress的平均性能比Apache Axis 1.2提高100%以上

    重掺半导体表面等离子体的研究

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    一种策略驱动的Web服务质量保障框架

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    随着面向服务计算技术的发展和应用,提供非功能属性保障能力成为服务在企业应用中获得成功的关键因素。同传统的分布式计算技术不同的是,服务是动态发现和绑定的,这要求服务双方必须动态协商并保障各种非功能属性。使用WS-Policy语言来显式描述Web服务的非功能性的能力和需求,并提出了一种策略驱动的服务保障框架来完成非功能属性的动态保障,最后在SOAP引擎SOAPExpress中实现了这一框架,结果表明它可以有效满足企业应用对Web服务质量的需求

    high performance soap processing based on dynamic template-driven mechanism

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    通过实验分析了Java平台上SOAP处理的性能,发现XML数据与Java数据间的数据模型映射是影响SOAP处理、决定Web服务性能的关键因素.对此,提出了一种新的数据模型映射机制--动态提前绑定,通过在运行时动态产生驱动数据模型映射的模板来避免耗时的Java反射操作,并实现XML数据对象和Java数据对象间的快速映射.动态产生的数据映射模板由上下文无关文法定义,并通过带输出的下推自动机实现.将此技术应用于自主开发的高性能SOAP引擎--SOAPExpress,实验表明SOAPExpress的平均性能比A

    无氢类金刚石薄膜表面H_2O和O_2分子共同作用的第一性原理计算

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    无氢类金刚石碳基薄膜(Diamond-like carbon,DLC)在潮湿大气环境中具有较低的摩擦系数,这主要是由于环境中的H_2O和O_2两种活性分子钝化了无氢DLC薄膜表面的悬键,但迄今两种活性分子对无氢DLC薄膜低摩擦行为的协同影响机制仍不清楚.本文中通过第一性原理计算方法研究了H_2O和O_2分子共存时在金刚石表面的钝化状态,并推测了无氢DLC薄膜实现低摩擦的可能途径.结果表明:H_2O和O_2两种活性分子在金刚石表面分解形成OH、H及O基团,其中O原子和H原子的相互吸引能够促使其形成OH基团.当H_2O分子和O_2分子按比例2:1共存时,金刚石表面全部由OH基团钝化,而非2:1比例时,金刚石表面会形成C-OH、C-H和C-O共存的复杂情况

    一种用于高通量气体样品分析的真空紫外光电离源

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    本发明涉及质谱分析仪器,具体的说是一种用于高通量气体样品分析的真空紫外光电离源,包括电离源腔体和真空紫外光源;于电离源腔体顶部设置有气体入口,气体样品通过气体入口进入到电离源腔体内部;在电离源腔体内部,沿气体样品流动方向依次设置有相互间隔、同轴、平行的离子引出电极、离子漏斗和差分接口极板;真空紫外光源设置于电离源腔体侧壁上,真空紫外光源发出的真空紫外光平行于离子引出电极的极板并穿过极板间相互间隔的区域进入到离子引出极板的通孔区域。本发明的真空紫外光电离源可有效提高整个质谱仪系统的检测灵敏度,在高通量气体样品分析和环境中有机污染物痕量或超痕量检测领域有着广阔的应用前景。待填

    中红外下半导体掺杂调制的表面等离子体透射增强效应

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    理论研究了平面电磁波通过n型重掺GaAs薄膜的透射谱.当GaAs薄膜两表面刻上亚波长的周期性沟槽结构时,透射谱在中红外波段出现了异常的透射增强现象.把这一现象归因于表面等离子体模式和波导模式的耦合.通过优化结构参数可以得到最大的透射效率.此外,发现随着掺杂浓度的升高,透射谱线中的透射峰逐渐向高频方向移动,最优化后透射峰值随掺杂浓度的升高而逐渐降低.这是由于掺杂浓度的改变,导致了不同的等离子体频率和电子碰撞频率,从而影响了激发模式和薄膜对电磁波的吸收
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