Time-resolved PL Spectra Study of Ordered Ga_(0.52)In_(0.48)P Alloys

【中文摘要】 在室温和低温液氮下 ,研究了有序和无序 Ga0 .52 In0 .4 8P的时间分辨发光谱。对实验结果的拟合表明 ,有序 Ga0 .52 In0 .4 8P的发光呈双指数规律衰退。其中快过程对应着有序区域上载流子的复合 ,慢过程则对应着有序区域和无序区域的空间分离中心上载流子的复合。无序 Ga0 .52 In0 .4 8P的发光在室温下呈单指数规律衰退。同时从低温下的时间分辨发光谱还可以看出有序样品的发光峰随着延迟时间的变长而蓝移 ,说明低温下在有序 Ga0 .52In0 .4 8P中存在着载流子从无序区域到有序区域的转移 【英文摘要】 The time resolved photoluminescence(TRPL) spectra of ordered and disordered Ga 0.52 In 0.48 P alloys grown by MOVPE were investigated.The least square fitting of the luminescence decay spectra of ordered alloys shows that there exist two exponential processes:The short lifetime process was corresponding to the high energy peak in PL spectra which is attributed to the recombination of the carriers in the ordered domains and the long lifetime process was corresponding to the low energy peak in the P...国家自然科学基金 (编号:69776011); 福建省自然科学基金 (编号:A9910004和 A0110007

Construction of polyoxometalates-based coordination polymers through direct incorporation between polyoxometalates and the voids in a 2D network

通讯作者地址: Long, YX (通讯作者), Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surface, Key Lab Analyt Sci,Minist Educ, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, Coll Chem & Chem Engn, State Key Lab Phys Chem Solid Surface, Key Lab Analyt Sci,Minist Educ, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 电子邮件地址: [email protected] series of polyoxometalates (POMs)-based coordination polymers, namely, {[Cu(2,3-Me(2)pz)(2,5-Me(2)pz)(0.5)](4)-(SiW12O40)(2,5-Me(2)pz)}(n) (2,3-Me(2)pz) =2,3-dimethylpyrazine; 2,5-Me(2)pz = 2,5-dimethylpyrazine; 1), {[Cu-2(4,4'-bipy) (4)(H2O)(4)](SiW12O40)(H2O)(18)}(n) (4,4'-bipy) 4,4'-bipyridine; 2), {[Cu(2-Mepz)(1.5)](3)(PMo12O40)(H2O)(3.5)}(n) (2-Mepz) 2-methylpyrazine; 3), {[Ag(2,3-Me(2)pz)(1.5)](4)(SiW12O40)}(n) (4), {[Cu(pz)(1.5)](4)(SiW12O40)(H2O)(3)}(n) (pz = pyrazine; 5), {[Cu(2,3-Me(2)pz)(1.5)](4)(SiW12O40)}(n) (6), {[Cu(4,4'-bipy)(1.75)](4)(SiW12O40)(H2O) 2}(n) (7), and {[Cu-2(4,4'-bipy)(4)(H2O)(4)](SiW12O40)(4,4'-bipy)(2)(H2O)(4)}(n) (8), were synthesized through direct incorporation between POMs and the voids of the 2D network. Crystal structural analysis reveals that the relationship between the size of the void of the 2D network and that of POMs is of key importance for successful synthesis of POMs-based open metal-organic frameworks. Guest replacement shows that the pore size of the framework constructed through direct incorporation between POMs and the voids of the 2D network is very sensitive to guest molecules

中国物理海洋学研究70年：发展历程、学术成就概览

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

移动Wimax系统中ICI抑制技术的研究

载波间干扰（ICI）主要由频率偏差所引起,它破坏了正交频分复用（OFDM）系统中子载波之间的正交性,大大降低了系统的性能。在高速移动Wimax系统中,信道的时变性导致的ICI更加不容小觑。文章将一种基于部分传输序列（PTS）算法的ICI抑制技术引入到移动Wimax系统中,针对其运算复杂的弊端提出了优化算法,并通过MATLAB语言进行了系统仿真,证明了算法对于Wimax系统中抑制ICI的有效性

Progress in Research of Mesoscale Eddies in the South China Sea

根据维基百科的定义(https:∥en.wikipedia.org/wiki/Edd),海洋中水平直径在10~500km、持续时间由数天至数月之; 间的水平旋转水体通称为中尺度涡。南海中尺度涡最早发现于1956年,60a来的观测与研究表明,南海是中尺度涡多发、频发海区。南海中尺度涡研究大致经; 历了早期发现、将中尺度涡当作单体运动现象研究、统计分析和当作群体运动现象研究等阶段,本文概要评述南海中尺度涡研究发展史和近年最新研究进展。经过6; 0a的观测与研究,南海中尺度涡的宏观特征,包括三维结构和运动学,已大致清楚。南海中尺度涡全年皆可发生,主要分布在水深大于1; 000m的深海盆,其中吕宋海峡以西和海盆西边界最为集中,气旋式冷涡和反气旋式暖涡发生概率大致相同。南海中尺度涡海面半径大多分布在50~150km; ,半径随水深减小,平均水平尺度比太平洋的涡旋要小。涡旋个数逐月变化,但季节规律不明显;年际变化幅度约20%,但与ENSO无明显对应关系;年平均个; 数的统计结果不一,最少11个·a~(-1),最多49个·a~(-1)。南海中尺度涡旋转流场从表层一直延伸到海底,流矢量表层(100m)最大(可达; 40cm·s~(-1)),随水深减小,2; 000m仍可达3.5~5.0cm·s~(-1),但相对涡旋中心不对称,涡轴线向西倾斜。南海中尺度涡以2.0~9.0cm·s~(-1)的速度向西传; 播,低速区分布在深海盆东边界和西南部分海域。海面涡度平均值在5.4*10~(-6)~20*10~(-6); s~(-1)区间,高于太平洋平均值。近期研究把南海中尺度涡视为群体运动现象,先后提出长寿涡列、驻波模态和罗斯贝标准模等新概念。关于南海中尺度涡的; 发生机制,前人多认为黑潮和南海局地为起源。最新观点认为以罗斯贝波和中尺度涡为表现形式的太平洋中尺度扰动直接进入南海,并与海盆固有振荡模态发生共振; ,从而构成太平洋起源。而南海中尺度涡耗散过程、中尺度涡与其他海洋过程的相互作用有待进一步研究。According to Wikipedia(https:∥en.wikipedia.org/wiki/Eddy),mesoscale; eddies in the ocean are rotating water masses with diameters between; about 10and 500km and lifetime from days to months.Mesoscale eddies in; the South China Sea(SCSME)were firstly observed in 1956.Since; then,60-years of observations and investigations have shown that the SCS; are a unique ocean area with energetic and high-frequency occurred; mesoscale eddies.The research of SCSME has passed stages of early; discovery,being studied as a single water mass motion and as grouped; water mass motion.This paper reviews the development history and new; progress in the research of SCSME.By 60-years of observations and; investigations, general characteristics of SCSME,such as the 3Dstructure; and the kinematics,have been mostly revealed. SCSME may occur all year; around.They are mainly distributed in the deep basin with the water; depth deeper than 1 000m,in particular concentrated in the west of the; Luzon Strait and the western boundary of the basin.The occurrence; frequencies of cyclonic eddies and anticyclonic eddies are near the; same.The sea surface radiuses of SCSME are mostly distributed with a; range from 50to 150km.The radius decreases with the water depth.The; average horizontal scale of SCSME is smaller than that in the; Pacific.The number of SCSMEs has monthly variation,but not obvious; seasonal variation.The amplitude of annual variation is about 20%,but; correspondence to the ENSO events is not supported by the; observations.The statistical results of annual number of SCSMEs are; inconsistent.The minimum number is 11per year,and the maximum is 49per; year.The rotating current field of SCSME extends from the sea surface to; the bottom. The current vector reaches the maximum value of 40cm·s~(-1); at the surface layer of 100m,decreases with the water depth to; 3.55.0cm·s~(-1) at 2 000m.SCSMEs propagate westward with velocities from; 2.0 to 9.0cm·s~(-1),and the low velocity areas are distributed in the; eastern boundary of the deep basin and the southwestern SCS.The mean; value of the sea surface vorticity of SCSMEs is within a range from 5.4; *10~(-6) to 20*10~(-6) s~(-1),higher than that in the Pacific.Recent; investigations treat SCSME as a grouped motion phenomenon,and have; proposed new concepts of long-lived eddy row,standing wave modes and the; Rossby normal modes.Of the generation mechanisms,previous investigators; have suggested the Kuroshio origin and the SCS local origins.The newest; point-of-view suggests that disturbance from the Pacific in the form of; the Rossby waves and eddies may enter the SCS directly and resonance; with intrinsic oscillation modes of the basin,so that forms another; Pacific origin.In addition,the dissipation processes and the interaction; of SCSMEs with other ocean processes are worth further pursuing.国家自然科学基金项目; 台湾海峡与吕宋海峡水体交换及相互作用研究; 广东省高等学校优秀青年教师项目; 广东海洋大学创新强校项

Satellite altimeter data analysis of the South China Sea and the northwest Pacific Ocean:statistical features of oceanic mesoscale eddies

采用AVISO提供的卫星高度计融合数据,对南海及西北太平洋(5°~35°n,105°~150°E)1993~2009年17A间的中尺度涡活动进行统计分析.结果表明南海中尺度涡活动具有明显的年际变化,每年观测到产生的中尺度涡个数平均为21~22个,标准差约为4个,占年平均值的20%;而西北太平洋中尺度涡个数的年际差异不大,平均每年观测到150~151个中尺度涡产生,标准差约为14个,仅占年平均值的9%.中尺度涡的逐月统计结果表明南海和西北太平洋的中尺度涡活动均有明显季节变化,1993~2009年间的各月南海和西北太平洋分别观测到30~31个和213~214个中尺度涡产生,标准差分别约为6个和41个,均占各自月平均值的19%.中尺度涡主要集中分布在南海东北部、越南东部和黑潮流轴附近海域.涡动能、海面高度距平均方根以及涡度均方根的空间分布大致与涡旋个数分布一致,但在西北太平洋的低纬海区和黑潮延伸体区域则不甚吻合.在相同的涡旋判别标准下,西北太平洋低纬海区(5°~15°n)观测到的中尺度涡个数比中高纬海区要少得多.17 years(1993--2009) of merged gridded satellite altimeter sea level anomaly(MSLA) data obtained from Archiving,Validation and Interpretation of Satellite Oceanographic data(AVISO) are used to analyze the activity of mesoscale eddies in the South China Sea(SCS) and the northwest Pacific Ocean(NPO;5°--35°N,105°--150°E).The results indicate that the eddy activity in the SCS has distinct annual variation.The average number of newly generated mesoscale eddies observed in the SCS is 21--22 in each year and the standard deviation is around 4,accounting for 20% of the annual mean value.By contrast,in the NPO,the eddy number varies relatively little in different years.Newly generated eddies observed in the NPO average 150--151 every year with a standard deviation of about 14,only 9% of its annual mean value.The monthly statistical results suggest that there are remarkable seasonal variations in both the SCS and the NPO.The average number of newly generated mesoscale eddies observed in the SCS and the NPO per month during 1993--2009 are 30--31 and 213--214,relatively,and the standard deviations are approximately 6 and 41,both accounting for 19% of the respective monthly mean value.Eddies are observed more frequently in the northeastern SCS,east off Vietnam and the vicinity of the Kuroshio axis.The spatial patterns of eddy number distribution are about the same with each other for anticyclonic eddies and cyclonic eddies,while there are some discrepancies in terms of the specific amount and positions.The spatial patterns of eddy number distribution are in good agreement with those of the eddy kinetic energy,the root mean square of sea level anomaly and the root mean square of vorticity in the studied area,except for that in the Kuroshio Extension area and in the tropical band of the NPO.The disagreements may be caused by the large-amplitude meanders and baroclinic instabilities for the former area,and that the geostrophic hypothesis is not valid in low-latitude area for the latter one.Under the premise of the same criteria for eddy identification,mesoscale eddies observed in the tropical area(5°--15°N) of the NPO are quite less than those at higher latitudes,the reason for which may be that the Rossby deformation radius is larger there.国家重点基础研究发展计划资助项目(2007CB411803;2009CB421208);国家自然科学基金资助项目(40976013;40821063);美国NOAA计划资助项目(05-01-11-000

Statistical analysis of the features of meso-scale eddies near the Luzon Strait

采用1993年1月到2008年12月16A融合海面高度距平数据,追踪吕宋海峡附近海域(18°~23°n,116°~126°E)中尺度涡的移动轨迹,结果表明:时间分辨率为7d的卫星高度计资料难以观测到中尺度涡从西北太平洋通过吕宋海峡传进南海的过程,但对1994年吕宋海峡中部观测到的一个气旋涡及其附近中尺度涡的运动轨迹进行分析可见,西北太平洋海面高度变化会与吕宋海峡内部海面高度耦合后向南海传播。海面高度距平数据的时间-经度图表明,西北太平洋海面高度变化信号在西传至吕宋海峡附近(121°~122°E)时出现信号不连续。对21°n,116°~140°E断面的海面高度距平数据按周期分别为1~3月、3~6月、330~390d(年信号)进行分段带通滤波,发现不同周期的西北太平洋信号穿过吕宋海峡传入南海受到的阻隔作用、向西传播的速度以及它们所受的强迫机制均不同。16 years(1993-2008) of merged sea level anomaly(MSLA) data obtained from Archiving,Validation and Interpretation of Satellite Oceanographic data(AVISO) are used to track the trajectories of meso-scale eddies near the Luzon Strait(LS)(18°-23°N,116°-126°E),and the results indicate that it is difficult to observe meso-scale eddies from the northwestern Pacific propagating into the South China Sea(SCS) through the LS based on the data with the temporal resolution of 7 d.The analysis on one cyclonic eddy observed in the middle of the LS in 1994,suggests that the sea level anomaly from the Northwestern Pacific propagates into the SCS through the LS after coupling with the original signal in the LS.The time-longitude diagram implies that the sea level anomaly signals become discontinuous near the LS(121°-122°E) when they propagate westward.After applying the band-pass filter to the sea level anomaly data in the section 21°N,116°-140°E with the periods of 1-3 month,3-6 month and 330-390 d,one can conclude that the signals from the Northwestern Pacific propagating into the SCS through the LS get different blocked,have different westward propagation velocity and have different forcing mechanisms for different period bands.国家重点基础研究发展计划(2007CB411803;2009CB421208);国家自然科学基金(40976013;40821063