155 research outputs found

    Preparation of Dendritic Pt Thin Films and Their Anomalous Infrared Effects

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    采用方波电位,在10x10-3MOl·l-1k2PTCl6+3x10-4MOl·l-1PbAC2+0.5MOl·l-1HClO4溶液中,于本体PT电极上电沉积制备出枝晶状PT薄膜.随着沉积时间的增加,枝晶长度逐渐由400nM增加到900nM,且枝晶上的小晶粒(--10nM大小)变得密集.根据循环伏安(CV)曲线中氢吸脱附电量可得出PT薄膜具有中等粗糙度(Cr=9-36),且电极表面的粗糙度随着沉积时间增加而增大.观察到PT薄膜上吸附态CO的原位红外光谱具有明显的增强吸收效应,当沉积时间为6MIn时所制得的枝晶PT电极的红外增强效应最大.CO呈现多种谱峰形状,随着沉积时间的增加,谱峰形状依次为左高右低的双极峰(类fAnO红外效应),单极向下(表面增强红外吸收),左高右低的双极峰,单极向上(异常红外效应),左低右高的双极峰和单极向下.这表明纳米材料薄膜所呈现出的特殊红外性能,与纳米材料的尺度和聚集状态等密切相关.所制备的枝晶状PT薄膜有望为深入认识纳米材料的特殊红外性能提供一个良好的模型材料.Dendritic Pt thin films are electrodeposited on bulk Pt electrodes in 10×10 -3 mol · L -1 K 2 PtCl 6 +3× 10 -4 mol · L -1 PbAc 2 + 0.5 mol · L -1 HClO 4 using square-wave potential pulses.As the deposition time increases, the length of the Pt dendrites increases from 400 to 900 nm, and the distribution density of Pt nanoparticles (--10 nm), which consist of coiled Pt dendrites, increases greatly.From hydrogen adsorption/ desorption obtained from cyclic voltammograms (CV), the surface of the dendritic Pt thin film electrodes has a relative roughness (C r ), which increases from 9 to 36 as the deposition time increases.Maximum enhanced IR absorption of adsorbed CO (CO ad ) is observed at the deposition time of 6 min.Anomalous infrared effects for CO ad are also seen on the dendritic Pt thin film electrodes.The line shapes of CO ad change with increasing deposition time, in order: bipolar→downward→bipolar→upward→bipolar→ downward bands.Fano-like infrared effects (bipolar), surface enhanced IR absorption (enhanced downward band), and abnormal IR effects (enhanced upward band) are highly dependent on the surface architecture of the nanostructures.The as-prepared dendritic Pt thin films provide model substrates for in-depth studies of the anomalous infrared effects of CO ad in metal nanostructures.国家自然科学基金(21073152;20933004;20833005;21021002);福建省高校杰出青年科研人才培育计划(JA10003)资助项目---

    An Optical High Temperature Thermometer for Plume Measurement of Solid Propellant Rocket Motor

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    利用辐射光谱测量温度的原理,设计并制造了一种新型的非接触式光学辐射高温计.详细介绍该温度计的基本原理和标定方法,并将该温度计应用于火箭发动机喷管出口羽流的温度测量中,初步的实验结果和数值模拟结果相一致

    2016年夏季南海海盆水体颗粒物粒径分布特征

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    颗粒物粒径分布(Particle Size Distribution,PSD)代表了颗粒物浓度与颗粒物粒径之间的关系,影响着海洋生态环境和水体光学特性等。文章基于2016年夏季航次调查的生物光学剖面数据,研究了南海海盆海域PSD的分布特征。研究发现,幂律函数可以较好地拟合南海海盆区域的PSD,对数空间中的实测的PSD与模拟的PSD平均决定系数高达0.95。PSD斜率(ξ)的分布范围为[1.27,7.65],均值为3.93±0.56。南海海盆区域表层水体的ξ均值与全球大洋表层水体的ξ均值相近,但高于海湾等表层水体的ξ均值。ξ能较好地表征颗粒物平均粒径DA的大小,两者存在明显负相关关系,即ξ值越高,DA越小;反之,DA越大。通过分析T1断面的生物光学剖面数据及总体平均的PSD剖面数据,发现PSD剖面分布特征如下:1)表层水体的ξ值相对较高,且DA值相对较低,推测可能是由于微微型藻类为主导颗粒物所致;2)ξ值极小值层出现在次表层叶绿素浓度极大值层(Subsurface Chlorophyll Maximum Layer,SCML)中,并伴随DA极大值层的出现,其原因可能是SCML中的大粒径浮游植物占比显著增加;3)弱光层中的ξ值较SCML中的高,但略低于表层的ξ值,而DA则位于表层与SCML的DA之间,这可能与浮游植物及其碎屑的絮凝、分解、沉降等过程相关。PSD特征影响着海水的固有光学特性,分析发现:由于SCML中的叶绿素浓度增加,颗粒物散射系数(bp(532))和颗粒物后向散射系数(bbp(532))也相应呈现显著增加的趋势。弱光层中的平均bp(532)与平均bbp(532)最小。ξ与颗粒物衰减光谱斜率之间呈高分散性,Boss等(2001b)的模型适合用于粗略估算区域性的ξ分布范围及均值。国家自然科学基金(41576030,41431176,4176045,4176044,41376042);;热带海洋环境国家重点实验室自主研究项目(LTOZZ1602);;广州市科技计划重点项目(201504010034,201707020023,201607020041);;广东省科技计划重点项目(2016A020222008);;中科院A类先导专项(XDA11040302)~

    Investigation of Structures of the Self-assembled Pseudorotaxane of Cucurbiturils with Some Alkyldiamines

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    以1H核磁共振技术和X射线单晶衍射分析方法考察了 3种瓜环与长链二胺 ( 1,7 庚二胺与 1,8 辛二胺 )相互作用的结构特征 .1HNMR分析表明瓜环 (Q[6]和Q[7] )与有机二胺 ( 1,7 庚二胺与 1,8 辛二胺 )有较强的相互作用 ,形成自组装类轮烷结构 ;Q[8]与 1,7 庚二胺与 1,8 辛二胺之间相互作用力相对较弱 ;晶体结构测定结果表明 ,六元瓜环与辛二胺自组装形成的类轮烷实体中 ,辛二胺是以直链状穿过六元瓜环的空腔 ,两配位氨基留在瓜环两端口之外 .The structures of self-assembled pseudorotaxane of cucurbit[n]urils(n=6~8) with some alkyldiamines have been investigated by 1H NMR technique and single crystal X-ray diffraction method. The results reveal that the interaction between cucurbit[6]uril or cucurbit[7]uril and 1,7-diaminoheptane or 1,8-diaminooctane is stronger than that between cucurbit[8]uril and 1,7-diaminoheptane or 1,8-diaminooctane, and the pseudorotaxanes of cucurbit[n]urils with the alkyldiamines were observed. Particularly, in the pseudorotaxane of cucurbit[6]uril with 1,8-diaminooctane, the amino groups of 1,8-diaminooctane are left outside the ports of cucurbit[6]uril.国家自然科学基金(No.200261002);; 贵州省重点基金(No.20023004);; 贵州省国际合作(No.200211003)资助项目

    Investigation of structures of the self-assembled pseudorotaxane of cucurbiturils with some alkyldiamines

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    The structures of self-assembled pseudorotaxane of cucurbit [n] urils ( n = 6 similar to 8) with some alkyldiamines have been investigated by H-1 NMR technique and single crystal X-ray diffraction method. The results reveal that the interaction between cucurbit[6]uril or cucurbit[7]uril and 1,7-diaminoheptane or 1,8-diaminooctane is stronger than that between cucurbit[ 8] uril and 1,7-diaminoheptane or 1, 8-diaminooctane, and the pseudorotaxanes of cucurbit[n] urils with the alkyldiamines were observed. Particularly, in the pseudorotaxane of cucurbit [6] uril with 1, 8-diaminooctane, the amino groups of 1, 8-diaminooctane are left outside the ports of cucurbit [6] uril

    中国物理海洋学研究70年:发展历程、学术成就概览

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    本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

    On the Storicity of History

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    人类生活的历史世界是否具有如叙述文本所呈现的故事性样式,这是一个引起广泛关注的理论问题。本文在当代西方历史哲学叙述主义宽广的理论语境下,通盘考虑了关于这一问题的正、反两方面的观点,认为生活历史中所发生的事件内在地具有情节及开头与结尾;更重要的是,基于叙述理解与实践活动间的互动关系,关于历史潜在地具有故事性结构的主张可以从理论上获得正当的辩护。当然,历史的潜在故事性,有赖于历史叙述赋予其现实形态。Whether the historical world in which humankind lived contains the structure of story as it is presented in narrative texts,is a theoretical issue which has aroused wide attention.This paper tries to give an overall survey of this topic,and discusses the positive and negative points about the issue within and beyond the current context of the development of Western narrative historical philosophy.It argues that the historical events in human life had inherent stories with their beginnings and ends.Therefore,based on the interaction between the narration of story and the practice of human life,the proposition of history containing the structure of story is tenable.2008年度国家社会科学基金项目“历史与叙述:叙述语义背景下历史本体论之思考”(08BZX046)阶段性研究成

    Naturalizing Phenomenology and Transcendental Phenomenology——Questioning the Program of Naturalized Phenomenology Advocated by Roy and Others

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    鲁瓦等人所提倡的现象学自然化要求放弃胡塞尔现象学的反自然主义立场,从而将现象学对意识结构的描述整合到认知科学中。然而,这一激进的自然化现象学方案误解了胡塞尔反自然主义的实质及其所包含的先验主义立场。作为一种先验哲学,胡塞尔现象学与认知科学的自然主义之间存在着明显的张力关系。重思自然主义与先验主义的关系是探讨现象学之自然化可能性的关键,就此而言,晚期胡塞尔先验现象学进一步反思先验主体性,并试图弱化和缓和先验哲学与经验科学之间的对立,为现象学与认知科学等经验科学之间的对话与合作留下了思想的空间。Jean-Michel Roy and others advocated the phenomenology for naturalizing purpose in an effort to abdicate the anti-naturalistic stance in Husserl's phenomenology,which integrated the phenomenological description of the structure of consciousness into cognitive science.However,this radical program of naturalizing phenomenology misconceived the essence of Husserl's anti-naturalistic concept as well as the transcendental stance contained within.As a type of transcendental philosophy,there is a clear tension between Husserl's phenomenology and naturalism that belongs to cognitive science.Reconsideration of the relationship between naturalism and transcendentalism is the key to exploring the possibility of naturalization of phenomenology,and for this purpose,Husserl's transcendental phenomenology in his later years could further reflect upon the transcendental subjectivity,and tried to weaken and ease the opposition between transcendental philosophy and empirical science,creating ideological space for dialogue and cooperation between phenomenology and cognitive science

    Truth: A Philosophical Analysis Based on Everyday Semantics

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    作为哲学和日常语言中双栖的词汇,“真理“的日常语义是我们厘清真理概念的重要理据。基于对真理的日常语义分析,真理在语义和概念上均不止于真,而是具有内在的意义(义理)蕴涵。在西方哲学的真理言说中,海德格尔独特真理观的要义之一正在于此。在英美和欧陆哲学两种真理观的背景下,人文真理源于存在的意义明证性,在严格性方面并不逊色于科学真理由决于事实而来的确定性。"Truth"is a term residing in both philosophy and everyday language.Analyzing its everyday semantics is fundamental for clarifying the concept of "truth"and can reveal that "truth"goes beyond being true in semantic and conceptual terms,but has intrinsic meanings.It is this idea that makes Heidegger unique in Western philosophers' discussions about "truth".In the wider context of two different views of truth advocated by British-American and European philosophers,the humanistic conception of truth emphasizes the validation of existence of meanings.This approach is,strictly speaking,by no means inferior to the view that posits that scientific truth must be ascertained by nothing but facts

    对中国现行外语教育必修制度的思考(上)

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    中国现行外语教育制度有一个显著特点,就是必修性:从小学、中学到大学、硕士、博士研究生等20多年的学习中,外语是惟一始终必修、必考的课程,甚至是硕士研究生入学考试两门公共必考科目之一,是博士研究生入学考试的唯一公共必考科目;一些高校实行学士硕士学位与外语四六级挂钩;外语专业学生还必须学习、考试第二外语;中级以上职称晋升还与职称外语考试挂钩。由于具有以上的必修性特点,笔者在此将中国现行外语教育制度称为“外语必修制度”
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