Novel synthesis of o-naphthothiophenequinone derivatives via regioselective Diels-Alder reaction

A novel procedure to construct o-naphthothiophenequinones has been achieved from readily available o-benzothiophenquinones and N-dienes via Diels-Alder reaction-aromatization sequence as key steps. The absolute regioselectivity was established via Diels-Alder reaction of o-benzothiophenquinones with rich electron N-dienes.     

Speckle characteristics of simulated deep Fresnel region under shadowing effect

After the three-dimensional self-affine fractal random surface simulation, we use the optical scattering theory to calculate the deep Fresnel region speckle(DFRS) under consideration of the more strict shadowing effect. The evolution of DFRS with the scattering distance and the intensity probability distribution are studied. It is found that the morphology of the scatterer has an antisymmetric relationship with the intensity distribution of DFRS, and the effect of micro-lenses on the scattering surface causes the intensity probability distribution of DFRS to deviate from the Gaussian speckle in the high light intensity area.     

采用单边大光腔结构改善电吸收调制器的光场分布

设计并制备了具有单边大光腔结构的半导体电吸收(electroabsorption，EA)调制器.模拟和测试的结果均表明：单边大光腔结构能有效地改善EA调制器的光场分布，使椭圆形的近场光斑变得圆形化，从而达到与圆形模式光纤之间的匹配，有利于提高耦合效率.     

激光扫描技术在靶场测试中的应用研究

为了解决光电类仪器在武器射击准确度和射击密集度的测试中遇到天空背景亮度不够,或弹丸口径小,弹道偏高而无法测试的问题,利用旋转棱镜使激光束在空中扫描,照亮弹丸表面,从而大大降低对光电传感器灵敏度的要求,使得该项测试工作不受天空背景条件的影响,并提高测试精度.     

非晶氧化钛薄膜形成过程中钛离子能量对表面结构影响的机理

研究了非晶氧化钛薄膜沉积过程中入射钛离子能量对表面结构形成机理以及薄膜特性的影响.模拟结果表明,通过提高入射钛离子能量,可以有效降低成膜表面粗糙度,从而减小薄膜表面的光学散射损耗.研究发现,当入射离子能量提高后,薄膜生长模式从"岛"状生长过渡到了"层"状生长,且离子入射点附近的平均扩散系数也有显著增加,这有利于形成更加平整的高质量薄膜表面.     

恒流电晕充电对聚四氟乙烯多孔薄膜驻极体驻极态的影响

利用常温下恒流和恒压电晕充电、充电后的等温表面电位衰减、热刺激放电和扫描电镜等实 验手段研究了恒流和恒压电晕充电技术对聚四氟乙烯多孔薄膜驻极体驻极态的影响.与恒压电晕充电相比较，恒流电晕充电时由于流过薄膜的电流恒定，增加了注入电荷在多孔结构厚度方向界面处的俘获概率，使沉积电荷密度上升，改善了驻极体的储电能力.然而，这些位于不同层深多孔界面处的俘获电荷在这类功能膜储存或使用过程中，经外激发从脱阱位置 以跳动（hopping）模式输运至背电极的路径相对缩短将导致脱阱电荷衰减较快. 关键词： 恒流电晕充电 聚四氟乙烯多孔膜 驻极体 电荷稳定性     

波长调制吸收光谱技术的燃气轮机燃烧室温度组分二维分布测量方法

可调半导体激光光谱技术（TDLAS）可实现温度、组分浓度等多参数同时测量,具有体积小、响应速度快、环境适应性高等优点,逐渐成为燃烧流场诊断的主要手段之一。TDLAS光谱测量常采用直接吸收技术和波长调制技术,其中强度归一化的波长调制技术,适合存在振动、湍流等致光束偏转效应和强辐射本底等恶劣应用环境条件的燃气轮机流场参数测量。基于TDLAS技术,开展了1f归一化波长调制技术燃气轮机燃烧室温度、组分浓度参数测量方法研究和实验室验证工作,并在某燃气轮机单喷嘴台架进行了冷态、热态试验验证,实现了燃气轮机燃烧室沿气流方向温度及H₂O、CH₄浓度二维分布测量。采用1f归一化波长调制技术抑制台架振动、热辐射背景噪声,采用1 392,1 469和1 343 nm蝶形封装的DFB激光器,三支激光器的出光方式为时分复用,选取H₂O的7 185.6,6 807.83和7 444.3 cm-1处的吸收线,两两组合使用,测量热态下一定范围内的温度和H₂O浓度;采用1 654 nm蝶形封装的DFB激光器,选取CH₄的6 046.96 cm-1处的吸收线进行冷态CH₄浓度测量。实验室对测量系统可靠性进行验证,配置4%~6%范围内的CH₄气体进行测量并与实际值对比,浓度测量最大相对偏差为3.72%;在高温炉中设定900~1 500 K范围内的温度台阶,充入纯水汽,计算不同设定温度和压力下的温度和浓度测量值,温度测量最大相对偏差3.07%,浓度测量最大相对偏差为-2.00%,验证了该测量系统的可靠性。台架燃气轮机实验中,集成了一套小型化测量仪器,设计多束激光收发一体的测量结构。实验采用两个电动位移台,搭载测量结构,每间隔5 mm逐点移动采样,对燃气轮机燃烧室300 mm×60 mm的燃烧区域进行测量,获取了若干工况下冷热态结果。通过双三次插值的方法绘制分辨率为0.5 mm的二维流场分布图,结果分别反映了测量区域范围内CH₄和火焰分布的真实状态。为燃气轮机喷嘴燃料、空气掺混情况和燃烧特性研究提供了新的研究方法和技术手段。     

Breather molecules and localized interaction solutions in the (2+1)-dimensional BLMP equation

The (2+1)-dimensional Boiti–Leon–Manna–Pempinelli (BLMP) equation is an important integrable model. In this paper, we obtain the breather molecule, the breather-soliton molecule and some localized interaction solutions to the BLMP equation. In particular, by employing a compound method consisting of the velocity resonance, partial module resonance and degeneration of the breather techniques, we derive some interesting hybrid solutions mixed by a breather-soliton molecule/breather molecule and a lump, as well as a bell-shaped soliton and lump. Due to the lack of the long wave limit, it is the first time using the compound degeneration method to construct the hybrid solutions involving a lump. The dynamical behaviors and mathematical features of the solutions are analyzed theoretically and graphically. The method introduced can be effectively used to study the wave solutions of other nonlinear partial differential equations.     

Progress of microscopic thermoelectric effects studied by micro- and nano-thermometric techniques

Heat dissipation is one of the most serious problems in modern integrated electronics with the continuously decreasing devices size. Large portion of the consumed power is inevitably dissipated in the form of waste heat which not only restricts the device energy-efficiency performance itself, but also leads to severe environment problems and energy crisis. Thermoelectric Seebeck effect is a green energy-recycling method, while thermoelectric Peltier effect can be employed for heat management by actively cooling overheated devices, where passive cooling by heat conduction is not sufficiently enough. However, the technological applications of thermoelectricity are limited so far by their very low conversion efficiencies and lack of deep understanding of thermoelectricity in microscopic levels. Probing and managing the thermoelectricity is therefore fundamentally important particularly in nanoscale. In this short review, we will first briefly introduce the microscopic techniques for studying nanoscale thermoelectricity, focusing mainly on scanning thermal microscopy (SThM). SThM is a powerful tool for mapping the lattice heat with nanometer spatial resolution and hence detecting the nanoscale thermal transport and dissipation processes. Then we will review recent experiments utilizing these techniques to investigate thermoelectricity in various nanomaterial systems including both (two-material) heterojunctions and (single-material) homojunctions with tailored Seebeck coefficients, and also spin Seebeck and Peltier effects in magnetic materials. Next, we will provide a perspective on the promising applications of our recently developed Scanning Noise Microscope (SNoiM) for directly probing the non-equilibrium transporting hot charges (instead of lattice heat) in thermoelectric devices. SNoiM together with SThM are expected to be able to provide more complete and comprehensive understanding to the microscopic mechanisms in thermoelectrics. Finally, we make a conclusion and outlook on the future development of microscopic studies in thermoelectrics.     

飞秒激光氘团簇库仑爆炸引发核聚变的机理研究

在超强飞秒激光与氘团簇的相互作用中，利用库仑爆炸模型，分析了可以引发核聚变的高能氘核产生的机理，提出了氘离子团簇膨胀尺寸与时间的关系式，计算了多种尺寸的氘团簇库仑爆炸时氘核的动能以及氘团簇的解体时间． 关键词： 飞秒强激光 氘团簇 库仑爆炸 核聚变