29 research outputs found

    The Geometric Structure of Nonlinear Least Square Solution for Signal by Complex Exponents and Alternate Algorithm

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    本文给出了复指数信号模型非线性最小二乘解的几何结构 .从分析迭代算法的收敛性态入手得到解的几何结构 ,将有助于构造十分有效的迭代算法 .另外 ,本文在低信噪比 (10dB)及较小频率差 (0 0 2Hz)的情况下 ,对迭代求解的收敛控制条件进行了研究The geometric structure of nonlinear least squares solution for signals by complex exponents is offered in this paper.Beginning with analysis for the convergent state of alternative algorithm solving two equations together contented by the model's nonlinear least squares solution,the recognition for geometric structure of nonlinear least squares solution is acquired.It would help to construct a fully effective algorithm and understanding for the solution's structure is deepened.The alternative algorithm presented by this paper is fully effective in higher SNR or when the difference of frequency in model is slightly increased.Nevertheless,the invalid convergence (large error) appears in the condition with lower SNR(10dB) and smaller difference of frequency (0 02 Hz),if the convergent control condition of alternative algorithm is only in accordance with varying quantity of least squares error

    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

    Observation of inhomogeneous plasmonic field distribution in a nanocavity

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    等离激元材料和器件中电场的强度分布是等离激元技术及其应用的重要基础。虽然针尖增强光谱成像技术的发展已经实现了亚纳米的横向空间分辨率,并发现了亚纳米级电场的不均匀性,但是迄今人们对电场的纵向场强分布仍然知之甚少。李剑锋教授课题组设计了一种具有~2Å空间分辨率的分子尺,利用金单晶基底和壳层隔绝金纳米粒子来构筑等离激元纳米腔,并通过分子尺的拉曼信号强度,精准地直接表征纳米腔中的纵轴方向上高度不均匀的场强分布。中国科学技术大学罗毅教授课题组利用基于量子场论的局域场光谱理论,精确地模拟得到了与实验相符的等离激元纳腔中的场分布,并发现了因分子自聚焦作用而引起的“等离激元梳”。该工作提供了一种通用有效的定量表征纳腔中场强分布的方法,完善了对等离激元学基础的理解,为超高空间分辨的拉曼光谱成像、光学力调控分子组装、单分子反应操控提供指导。 该工作是在李剑锋教授和中国科学技术大学罗毅教授共同指导下完成的。实验部分主要由李超禹(论文第一作者,已毕业博士)、温宝英(在读博士)、李松波(已毕业硕士)完成,复旦大学段赛研究员(论文共同第一作者)和陈舒(已毕业博士)进行了局域场光谱理论计算。谢立强(已毕业博士)和毛秉伟教授帮助完成了扫描探针显微镜实验。浙江师范大学周小顺教授和王亚浩老师提供了自组装膜表征方面的重要帮助。印度的Kathiresan、叶龙武教授课题组和浙江大学陆展教授课题组在分子合成方面提供了重要帮助。瑞士伯尔尼大学Wandlowski教授和田中群教授为该工作提供了指导。【Abstract】The progress of plasmon-based technologies relies on an understanding of the properties of the enhanced electromagnetic fields generated by the coupling nanostrucutres.Plasmon-enhanced applications include advanced spectroscopies, optomechanics, optomagnetics and biosensing. However, precise determination of plasmon field intensity distribution within a nanogap remains challenging. Here, we demonstrate a molecular ruler made from a set of viologen-based, self-assembly monolayers with which we precisely measures field distribution within a plasmon nanocavity with ~2-Å spatial resolution. We observed an unusually large plasmon field intensity inhomogeneity that we attribute to the formation of a plasmonic comb in the nanocavity. As a consequence, we posit that the generally adopted continuous media approximation for molecular monolayers should be used carefully.The progress of plasmon-based technologies relies on an understanding of the properties of the enhanced electromagnetic fields generated by the coupling nanostrucutres1,2,3,4,5,6. Plasmon-enhanced applications include advanced spectroscopies7,8,9,10, optomechanics11, optomagnetics12 and biosensing13,14,15,16,17. However, precise determination of plasmon field intensity distribution within a nanogap remains challenging. Here, we demonstrate a molecular ruler made from a set of viologen-based, self-assembly monolayers with which we precisely measures field distribution within a plasmon nanocavity with ~2-Å spatial resolution. We observed an unusually large plasmon field intensity inhomogeneity that we attribute to the formation of a plasmonic comb in the nanocavity. As a consequence, we posit that the generally adopted continuous media approximation for molecular monolayers should be used carefully.The Swedish National Infrastructure for Computing is acknowledged for computer time. S.D. is sponsored by Shanghai Pujiang Programme (grant no. 19PJ1400600). 该研究工作得到国家自然科学基金、国家重点研发计划、安徽省量子信息技术引导专项等的资助和支持

    养殖水体中的微型裸腹溞对高浓度鱼类化学信息素的反应:以生命表研究为例

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    本文通过研究微型裸腹溞的生活史,探讨了当东湖养殖的鲢鳙密度进一步增大时,它们释放的化学信息素对微型裸腹溞的间接作用,同时也讨论了微型裸腹溞在高密度鱼类捕食下种群能够延续的可能机制。在淡水生态系统中,无视力的生物能通过化学物质的交流来感知环境中的捕食压力,从而作出相应的调整策略。本研究结果显示高浓度的鱼类化学信息素对微型裸腹溞的生活史并没有显著影响,意味着微型裸腹溞有可能通过与该鱼类的长期共存而适应了这类物质。但是我们的结果与前人的相比还是存在着很大的差异,尤其是明显提高的总后代数、平均怀卵量和内禀增长力

    Studies on the acquiring method for the son-wave of experimental data in voltammetry

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    分析研究了伏安法标准加入浓度曲线 (子波 )的提取方法 .从分析子波畸变的特征入手 ,结合基于奇异值分解原理的TLS算法 ,提出了一种两组份浓度子波峰形的相关滤波叠代求解方案 .The acquiring method for the son-wave (standard addition's) of experimental data in voltammetry has been discussed in this paper. By feature-recognizing for the son-wave's distortion and applying of TLS algorithm,one related filtering algorithm is presented

    Method for Preprocessing Experimental Data of Voltammetry

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    研究伏安法实验数据的预处理方法 .采用基于奇异值分解原理的 TL S算法 ,对经过预处理后的实验数据进行再处理 ,取得良好的效果 .文中着重讨论各种预处理方法的合理性和有效性 ,并对 TL S算法的适用性进行探讨A study is made on the method for preprocessing the data from voltammetric experiment. Good effect can be obtained for the experimental data passed through preprocessing and then processed by adopting total least square (TLS) algorithm which is based on the principle of singular value decomposition. The authors discuss the reasonableness and effectiveness of various methods of preprocessing, and inquire into the compatibility of TLS algorithm.福建省自然科学基金资助项

    伏安法实验数据子波信息提取方法的研究

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    从实际测得的伏安法实验数据出发 ,分析研究了伏安法标准加入浓度曲线 (子波 )的提取方法。从分析子波畸变的特征入手 ,结合基于奇异值分解原理的TLS算法 ,提出了一种两组份浓度子波峰形的相关滤波叠代求解方案
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