1,648 research outputs found

    A Kind of Large Load Light UAV Conceptual Design Platform and Manufacturing

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    近年来,无人机在军事领域的地位越来越重要;在民用领域,无人机的重要性也日益凸显。轻型无人机具有结构简单、体积较小、飞行高度低、飞行速度慢等特点,俗称“低小慢”航空器,可以利用较小的空间进行收放,起飞准备时间短,方便使用者利用有限的时间和空间进行工作。近几年来,随着飞控技术被不断重视,各方面科研力量都着手研制自己的飞控系统,同时各个拥有航空背景的高等学府也纷纷投入其中。作为高校,研制飞控系统需要有适合做飞行实验的飞行平台,此时,轻型无人机就可以发挥重要作用。因此,能够自主设计制造一款适合高校无人机飞控实验的轻型无人机就可以很好地满足各类需求,还能掌握一整套轻型无人机设计制造流程,为刚接触无人机行...In recent years, unmanned aerial vehicles in the military field position more and more important; in civilian areas, the importance of UAVs have become increasingly prominent. Light UAV has a simple structure, small size, low height flight, slow flight characteristics, commonly known as "low small, slow" aircraft that can take advantage of a smaller space retractable, ready to take off time is sho...学位:工学硕士院系专业:航空航天学院_工程硕士(机械工程)学号:1992013115292

    Design and Research on Digital Public Space

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    数字化的冲击是我们这个时代无法回避的问题,这种冲击渗透到社会、政治、文化、生活等方方面面。正如美国著名的未来学家尼古拉斯•尼葛洛庞帝(NicholasNegroponte)在其20年前的个人巨著《数字化生存》中对未来世界的预言“信息DNA正在迅速取代工业经济时代的原子,成为人类生活的交换物。” 随着信息科技的迅猛发展,人们的生活正在被二进制的数字化形式所改变,很显然,全球已经迈入一个全新的数字化时代。这个时代与以往有着截然不同的变化,人们身份的虚拟化、性别的模糊化、知识的可塑性等,以及当数字化元素介入公共空间之后,公共空间出现了颠覆性的转变,新的数字空间完全超越了现实空间的范畴,...In our era, the impact of digitalization is unavoidable, which has been deeply influencing all aspects, including the society, politics, culture and life. 20 years ago, Nicholas Negronte, a famous American futurist made his prediction about the future world in his masterpiece Being Digital, saying that information DNA is rapidly replacing the atom of the era of the industrial economy and becoming ...学位:文学硕士院系专业:艺术学院_美术学学号:1862013115357

    Genetic Analysis on Grain Shape and Mapping, Cloning and Characterizing of Major Grain length Gene in rice

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    水稻是世界上最重要的禾谷类作物之一,提高水稻产量和改善稻米品质是水稻遗传与育种研究的永恒主题。水稻粒形是粒长、粒宽、长宽比及粒厚的综合性状,是稻米外观品质的重要指标,同时对稻米的碾磨品质、食味品质及产量均有重要影响。厦门大学水稻遗传育种研究室长期致力于大粒优质水稻新品种的遗传与育种研究,前期采用60Co-γ射线辐照水稻成熟花粉诱变方法,获得了一批遗传上稳定的长粒大粒水稻种质材料并广泛应用于优质籼稻育种中。为了解这些大粒材料谷粒性状的遗传基础,本研究选择其中的三个大粒品系JF171、JF178、JF3与引进的小粒品种Samba配制杂交组合,并构建遗传群体,对谷粒性状进行遗传分析及相关数量性状基因...Rice (Oryza sativa L.) is one of the most important cereal crops in the world. Grain yield increase and grain quality improvement are two fundamental challenges in rice genetics and breeding. Rice grain shape is a phenotype controlled genetically by quantitative trait loci (QTLs). It is characterized by a combination of grain length (GL), grain width (GW), grain length to width ratio (LWR) and gr...学位:理学博士院系专业:生命科学学院_遗传学学号:2172008015040

    日本视角:不只是技术的精益求精(三)

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    前几天在CCTV9看了一个不长的译制专题片《创造历史的动物2:蚕》,内容是很符合科学技术史的口味的——它叙述了养蚕和制丝技术的西传。在历史的回顾之外,影片显示:当下蚕丝制造的最高水平显然是在巴西。精选留种用蚕茧;人工控制从蛹到蚕蛾的蜕变;将雄性涂成红色,提高雌雄交配的效率;在卵和幼虫孵化的环节剔除不良部分;5000家农户在工场附近养蚕,由于气候适应,巴西每年能养8代蚕;全自动烘茧和制丝技术保证产品质量的稳定,20公斤蚕茧能产

    中山茂先生学术评传

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    中山茂(1928~2014年)先生是日本著名科学史家,同时也是李约瑟在日本的重要支持者。他生在大阪,长于广岛,并于1945年亲历了原子弹爆炸。战后他进入东京大学学习天文学,毕业后赴哈佛大学留学,于1960年获科学与学术史博士学位之后回日本东京大学任教。中山茂先生在科技史领域业绩很多,尤以翻译库恩的《科学革命的结构》从而将其"范式论"介绍到日本一事最广为人知。此外,从研究中国和日本的天文学史出发,他的研究业绩广及与东亚的近代化相关联的科学技术史、大学史,以及现代科学技术社会史

    The Research on Chinese Character Acquistion of Intermediate Chinese learners of Mae Fah Luang University

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    汉字教学研究是汉语作为第二语言教学的一个重要分支。汉语国际传播背景下的泰国大学生的汉字教学研究仍需进一步深化。本文以泰国皇太后大学中级汉语学习者在大二下学期期中、期末考试书写的798篇作文223487字的一手真实语料为研究材料,统计14个平行班级涉及3个不同专业的学生的汉字书写整体情况,并分析书写错误的汉字,考察具有规律性的汉字偏误情况及其成因,再根据结论提出改善中级汉字教学的相应对策。力争找到能帮助泰国学生又好又快地习得汉字的合适对策,提高学生的汉语书面语水平和语言文字的应用能力。 研究过程中运用多种手段,主要有:a.文献研究法(购买新出版的专业纸质书籍、搜集下载电子版的中外文文献);b....Teaching Chinese characters is an important branch of teaching Chinese as a second language. The study of Chinese characters teaching in Thailand under the background of Chinese international communication still needs to be further deepened. This paper takes Mae Fah Luang University intermediate Chinese learners in the 798 essay sophomore next semester midterm and final exam to write 223487 words ...学位:汉语国际教育硕士院系专业:海外教育学院_汉语国际教育硕士学号:2652014115125

    荧光原位杂交技术和流式细胞仪用于环境样品中产毒及非产毒微囊藻的定量监测

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    全球范围内,高频次、大范围暴发的蓝藻水华对淡水水体环境造成严重影响.微囊藻因其在生长特别是衰亡过程中向水体释放微囊藻毒素而威胁人类健康.因此,分析其产毒株及非产毒株在环境样品中的组成,建立产毒蓝藻的预报及评价体系显得极为重要.本文采用荧光原位杂交技术结合流式细胞技术实现对环境样品中产毒藻株的鉴别与定量.针对目标基因mcyA设计的、以地高辛标记的双链DNA探针可有效应用于产毒微囊藻FACHB905和PCC7806的鉴别.分别对来自滇池、太湖和关桥的11个样品进行分析显示,该方法与传统的形态学鉴定及PCR方

    热力学在无机化学“四大平衡”教学中的应用

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    利用化学反应吉布斯自由能变化?_rG_m~?来计算无机化学\"四大平衡\"的平衡常数,解释诸如沉淀-溶解平衡教学中为什么要求微溶强电解质等问题,并从化学反应等温式类推了电极反应的等温式,推导了复杂电极的标准电极电势与其简单电极的标准电极电势之间的关系,拓展了热力学在现行基础化学教学上的应用范围。国家基础科学人才培养基金(J1310024

    Study on the Preparation and Electrochemistry of Anode Catalyst for Direct Methanol Fuel Cell

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    目前,贵金属铂(Pt)是常用的直接甲醇燃料电池(DMFC)的阳极催化剂,但其价格昂贵、资源少及易被毒化等缺点,限制了DMFC的商业化。PtAu核壳结构的中空微球(H-PtAu)代替纯铂作为阳极催化剂,一方面可以降低成本,另一方面可以提高催化活性,增强其稳定性。本文首先采用不同的方法制备了不同粒径的金纳米粒子,确定了制备不同粒径的金纳米粒子的最佳工艺参数。然后利用二氧化钛(TiO2)为催化剂载体或模板,通过简单地调节反应溶液的pH值制备了TiO2载PtAu微球(PtAu/TiO2)和H-PtAu,并对其物化性质进行了一系列表征,同时采用循环伏安法对其电化学性能进行了测试。主要结论如下: (1)...At present, platinum is regarded as the most commonly used anode catalyst of direct methanol fuel cell (DMFC). However, the high price, limited resource and low tolerance to CO poisoning restrict its business applications. The hollow PtAu sphere (H-PtAu) instead of pure platinum catalyst should reduce the loading of platinum and improve the electrocatalytic activity and stability of anode catalyst...学位:工学硕士院系专业:化学化工学院_化学工程学号:2062010115144

    QTL Mapping, Epistasis and Environmental Effects Analysis for Rice Chalkiness Trait

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    水稻的垩白性状是当前限制中国稻米品质提升的最主要因素.研究垩白形成机理及遗传特性,将有利于提高育种中垩白性状的改良效率.本课题组先前构建了广陆矮; 4号/佳辐占重组自交系(GJ RIL)及遗传图谱.本研究连续2年在上杭县和龙海市两地共种植6季GJ; RILs,据各季垩白性状表型数据进行遗传分析,结合遗传图谱进行QTL定位、上位性分析和环境效应分析.遗传分析发现垩白粒率和垩白度呈偏态分布,推测; 垩白性状受主效基因与微效基因共同影响.QTL定位中,垩白粒率获得3个QTLs,qPGWC2、qPGWC4和qPGWC5,遗传贡献率分别为2.84; %、3.74%和14.09%;垩白度获得3个QTLs,qDEC1、qDEC4和qDEC5,遗传贡献率分别为2.96%、4.88%和7.79%.上; 位性分析中,垩白粒率和垩白度分别获得7对和5对上位性QTLs,贡献率为0.23%~3.55%.RM307~RM518区间内同时检测到垩白粒率和垩; 白度的QTLs,并参与了垩白粒率和垩白度的上位性互作.RM598~RM5140区间内也同时检测到垩白粒率和垩白度的QTLs,也参与了垩白度的上位; 性互作.环境效应分析发现,垩白度的3个QTLs及~eqDEC10和~eqDEC9这对上位性QTLs均与2010年早季龙海种植环境发生显著或极显著; 的互作效应.Rice (Oryza sativa L.) chalkiness is the most important limiting factor; for currently improving rice quality in China. Studying rice chalky; formation mechanism and hereditary character will be helpful for; increasing the efficiency of the improvement of chalky quality in; breeding. A Guanglu'ai No.4/Jiafuzhan recombinant inbred line(GJ RIL); was developed and its genetic map was constructed previously by our; research group. In this study, the genetic analysis of rice chalkiness; was carried out basing on the chalky phenotyping data of GJ RIL from a; total of 6 growth seasons of two different locations, Shanghang county; and Longhai city, in two consecutive years. Then the QTL mapping,; epistasis and environmental effects of chalkiness were studied by using; these phenotying data and the genetic map. The genetic analysis; indicated that percentage of grains with chalkiness (PGWC) and degree of; endosperm chalkiness (DEC) showed skewness distribution, suggesting that; chalkiness trait was affected by both major and minor genes together. In; QTL mapping, three PGWC QTLs, qPGWC2, qPGWC4 and qPGWC5, were detected,; which explained 2.84%, 3.74% and 14.09% of the genetic variation,; respectively. Three DEC QTLs, qDECl, qDEC4 and qDEC5, were mapped, which; explained 2.96%, 4.88% and 7.79% of the genetic variation, respectively.; In QTL epistasis analysis, 7 and 5 pairs of epistasis QTLs for PGWC and; DEC were identified respectively, and their contribution rates ranged; from 0.23% to 3.55%. The RM307~RM518 interval harbored the PGWC and DEC; QTLs, which were involved in epistatic interaction of PGWC and DEC; respectively. The RM598~RM5140 interval also harbored the PGWC and DEC; QTLs, which also participated in epistatic interaction of DEC.; Environmental effect analysis showed the three DEC QTLs (qDECl, qDEC4; and qDEC5) and a pair of epistatic QTLs between ~eqDEC10 and ~eqDEC9 all; exhibited significant or very closely significant interaction effects; under the environmental conditions in early season at Longhai city of; Fujian province in 2010.福建省中青年教师教育科研项目; 厦门大学中央高校科研基本业务
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