36 research outputs found

    Research on the Non-uniform Temperature Field for Purifying Polysilicon in Large Directional Solidification Equipment

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    太阳能资源分布广泛并可无偿获取,使光伏发电成为新型能源的重要发展方向之一。因其发电组件具备建设周期短、安全可靠、布置灵活等优点得到了人们的青睐。硅作为光伏发电主要的基础材料,已占据市场90%以上的份额。冶金法提纯多晶硅具备投产建设速度快、提纯工艺流程短、成本较化学法低等优点,近年来发展迅速,受到国内外的广泛重视。 定向凝固是冶金法的核心。与中小型提纯相比,大型定向凝固的生产效率高,综合成本较低,但固液界面较难维持水平,晶粒不易保持垂直方向上的整齐排列,凝固和退火过程中裂锭的概率也较大,对温度场构建、设备用材、控制策略均提出了更高的要求。本文针对提纯体积达1000mm×1000mm×450mm...Solar energy resources are widely distributed and can be obtained easily, so that the photovoltaic power generation has become an important direction of development of new energy. It has been widely accepted by people because of its short construction period, safety and reliability, flexible placement. Silicon is the main basis of photovoltaic power generation, has accounted for more than 90% of t...学位:工学博士院系专业:物理与机电工程学院_测试计量技术及仪器学号:1992012015387

    Research and Theoretical analysis of Ultrasonic Vortex Anemometer

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    风速的测量作为流速测量领域一个重要的部分,与人们的日常生产、生活已密不可分。古时候的中国人就利用风吹芦苇的弯曲程度以及随风飘扬的旗帜来估计风速的大小;现代科技的发展更促使其广泛地应用在航天航空、科研实验、现代农业及气象科学等重要的领域。 为了满足各个领域的使用要求,科技人员开发出了种类繁多、各具特色的风速仪表。根据测量的原理,风速计可分为转轮式(风杯式与旋桨式)、热敏式、热线式、超声式、皮托管式等五大类,数十个品种。其中,利用涡街发生体(VortexGenerator)产生旋涡原理制成的涡街风速计因具备测量范围大、无活动耗损部件,便于携带等优点获得了广泛的应用。 本课题的主要内容是开发一种...As an important part of measuring fluent, measuring wind velocity has set a close relation with people’s ordinary life. In ancient times, Chinese had made use of the reed and flag in wind to estimate wind velocity, and which has been applied widespread in the field of aerospace, scientific research, modern agriculture, meteorology and so on by the development of modern science and technology. To ...学位:工学硕士院系专业:物理与机电工程学院机电工程系_机械制造及其自动化学号:2005130169

    Design and numerical simulation of novelvortex generator

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    涡街发生体是涡街流量计的关键部件之一,其流体力学外形决定了涡街流量计的量程、精度。设计了一种新型的涡街发生体,并通过CFD软件FLUENT对新型涡街发生体和目前常用的涡街发生体进行数值仿真、理论分析和比较。结果表明:在实际应用中,新型涡街发生体的流体力学性能优于其他涡街发生体,适合高、低流速下产生强度大且稳定的涡街。Vortex generator is an important component of vortex flowmeter.The shape of CFD decides vortex flowmeter's range and accuracy.A novel vortex generator is disigned,its numerical value is simulated and the theory is analysed by FLUENT,and the other common generators are compared with it.As a result,through practical application,the advanced vortex generator has a better performance than others,it is able to make powerful and steady vortexes in low or high Renault value.福建省重大专项前期研究计划资助项目(2005HZ1022

    Directional Solidification of Polycrystalline Silicon in Non-uniform Thermal Field

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    设计一种辐射加热装置环状布置的多晶硅定向凝固设备,通过构建非均匀热场,使硅熔体侧壁区域温度高于中央区域,在熔体密度差的作用力下,液相自然对流强度加剧,使固液界面富集的杂质加速汇聚至熔体表面,提高杂质提纯效率,并在满足工艺要求的同时达到节能目的。进行数学建模和数值模拟研究来阐述该热场的设计原理,并通过试验验证。试验表明,环状加热方式使晶粒生长方向略微外倾,相对于传统加热方式,其能耗更低、并提高了除P、Al效率。A directional solidification equipment with annular radiation heat device is designed for polysilicon purification.By constructing an inhomogeneous hot field,the temperature of the lateral wall of the silicon melt is higher than that of the central region.The natural convection intensity of the liquid phase increases because of the melt density difference.So the impurity in the solid-liquid interface accelerates converging to the surface of the melt.It can make strong natural convection in the liquid phase,improve impurities purification efficiency,meet the process and achieve the purpose of energy saving at the same time.Theoretical research and numerical simulation is used to illustrate the principle,and is verificated by experiment.Experiment results show the heating mode makes direction of grain growth slightly tilt outward,compared with the conventional heating mode,it makes energy consumption and content of P,Al lower.福建省高校产学合作科技重大项目(2012H6023); 福建省高端装备制造协同创新中心资

    Study on Application of Heat Compensation Structure in Polycrystalline Silicon Directional Solidification Equipment

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    定向凝固(dS)是冶金法提纯太阳能级多晶硅的重要工艺环节。以保证垂直的晶体生长方向,维持良好的固液相界面形态为目的,设计了一种带有热量补偿结构的多晶硅定向凝固设备,用以替代常规设备的侧壁加热装置,在满足工艺要求的同时达到节能减排、降低成本的目标。进行理论分析和数值模拟来阐述原理与设计结构,对优化凝固工艺、设备结构、控制方法提供了理论依据与技术支持。Directional solidification(DS) is an important technological link of manufacturing solar grade(6N) polycrystalline silicon by metallurgy.In order to ensure the vertical direction of crystal growth,maintain a good solid-liquid interface shape,the directional solidification equipment of polycrystalline silicon with heat compensation cavity structure was designed for replacing the lateral heating device of the conventional equipment,which meets the process requirements,saves power and reduces cost at the same time.The principle was illustrated and the structure was designed by the theoretical analysis and numerical simulation.It provides theoretical basis and technical support in the optimization of solidification process,equipment structure and control method.福建省高校产学合作科技重大项目(2012H6023

    类泛素蛋白及其中文命名

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    泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

    一种新型的用于数字信号处理的进化硬件原胞结构

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    采用CORDIC算法在单一的电路体系结构下实现了具有多种算术功能的进化电路原胞.该原胞可以作为构建此类进化硬件的基本组成模块.分析表明,采用CORDIC算法的原胞具有丰富的运算能力而只消耗较少的芯片资源,可以成为一种有前途的用于数字信号处理功能级进化电路的原胞设计的方案

    离心力对制备沉积物间隙水中化合物浓度的影响

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    研究了离心力对间隙水化合物浓度的影响。将腐殖质掺入东湖沉积物样品 ,按泥∶水 =1∶4 (体积 )比室温下静置 30d ,随后掺入铜 ,泥∶水 =1∶4 (体积 )比静置 10d ,得到总有机碳含量在 1 4 7%— 5 72 %、铜含量在 12 0— 2 70 0mg/kg(干重 )的试验沉积物样品 ,用离心法制备沉积物中的间隙水。离心参数为 30 0 0r/min、5 2 0 0r/min、90 0 0r/min、10 5 0 0r/min和 12 0 0 0r/min ,4℃下离心 2 0min。

    利用微卫星标记扩充水稻双单倍体群体的遗传图谱

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    Kinematic Error Modeling for Tailored Blank Laser Welding Machine Based on the Improved MBS

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    采用改进的多体系统建模理论对激光拼焊生产线运动误差进行研究。用低序体阵列描述多体系统拓扑结构,用特征矩阵表示多体系统中间体的相对位置和姿态。在基于多体系统理论的误差建模基础上提出位置误差传递函数的概念,用来描述各个误差源对位置精度的影响。根据激光拼焊生产线的结构特点,运用改进的多体系统理论精度分析理论,对激光拼焊生产线运动精度进行系统、全面的分析。采用Leica激光跟踪仪对激光拼焊线的运动误差进行检测,并将检测结果与误差模型分析结果进行对比,结果表明所建立的模型能有效预测激光拼焊线的运动误差
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