高效率放电抽运KrF准分子激光器

248 nm放电抽运KrF准分子激光器在微电子学和医学等领域有重要的应用价值。在大多数应用中,激光器的最大输出效率和能量都是十分重要的参数。为了提高激光器输出效率和能量,实现KrF准分子激光器的稳定放电,采用新型开关电源和结构紧凑的张氏电极,并通过优化储能/放电电容比例和工作气体配比等方法,研制出了一台小型高效率放电抽运KrF准分子激光器。研究了开关电源对充放电特性的影响,以及气体配比对激光输出效率和能量的影响。该激光器的各项参数相比以往的产品有了较大改善,可重复频率为1~80 Hz,输出效率最高达2.5%,最大单脉冲输出能量380 mJ;当工作电压高于25 kV时,激光输出能量不稳定度约为1.8%。     

小波变换在位相展开中的应用

在结构照明型光学三维传感和干涉型计量技术中，都需要将计算出的截断位相恢复为物理参数对应的连续位相，位相展开的过程中，对于十分复杂的截断位相，如何有效地标记出极点和截断线是至关重要的。本文提出利用小波变换寻找截断线的方法，利用小波变换系数的模极大值与局部奇异性的关系，通过检测小波变换系数模极大值的位置来标记截断线的基本走向，进而采用图像处理中的二值数学形态学处理方法形成完整的截断线，构成指导位相展开的控制模板，新算法有效地标记了极点和截断线，将位相展开的错误限制在局部范围。本文给出了这种算法的详细分析和计算机模拟实验的结果。     

有机胺碱对硅粗抛光及表面微形貌的影响

硅单晶抛光片是极大规模集成电路应用最广泛的衬底材料,抛光液为影响硅单晶片抛光最关键的因素。通过改变抛光液中有机胺碱配比来调节抛光液的pH值。实验结果表明:随着有机胺碱比例的不断增加,pH值随之上升,硅片的去除速率(material removal rate,MRR)先增大后减小。pH值在10.5左右时去除速率达到最大值(1706nm/min)。此时用Agilent 5600LS型原子力显微镜测得硅片表面的粗糙度为0.369nm。并用马尔文Zetasizer 3000HSA纳米粒度分析仪测定不同有机胺碱浓度下的抛光液中水溶胶磨粒粒径变化。通过对实验后晶片表面进行检测并结合去除速率综合考虑,抛光液pH值宜选择为10.5左右。抛光速率在pH值为10.3～10.6比较稳定。     

Multigaps Embedded Nanoassemblies Enhance In Situ Raman Spectroscopy for Intracellular Telomerase Activity Sensing

The highly sensitive and quantitative biodetection of intracellular telomerase is challenging. A DNA‐driven nanoparticle self‐assembling pyramid encoding a Raman reporter (Cy5) is reported that detects telomerase in live cells. In the presence of the target, the telomerase primer is extended and the inner DNA chain is replaced, leading to the reduction in the surface‐enhanced Raman scattering (SERS) signal and the simultaneous recovery of the fluorescent signal. The SERS signal has a linear range for the detection of telomerase in situ of 1 × 10^–14 to 5 × 10^–11 IU, with a limit of detection of 6.2 × 10^–15 IU. The fluorescent signal is used to confirm the intracellular telomerase activity, demonstrating the efficacy of the designed pyramid probe. This biosensing strategy provides a reliable and ultrasensitive protocol for the quantification of biomarkers in living cells.     

评过剩吸附量和绝对吸附量关系式的不正确性

页岩吸附气和煤层吸附气都是重要的非常规天然气资源。该资源的评价依赖于在不同压力下等温累积吸附量的计算和等温饱和吸附量的确定。不同压力下的等温累积吸附量,需要通过吸附仪的测试资料,利用有关的计算方法求得。基于1976年Adamson(阿达姆森)提出的固相对气相吸附质量的关系式是不确定的,因此,1998年Donohue和Aranovich引用Adamson的吸附关系式,并提出过剩吸附量和绝对吸附量及其关系式也是不正确的。周理等于2000年发表的文章,确认和引用了Donohue和Aranovich过剩吸附量和绝对吸附量及其关系式同样是不正确的。在2015至2018年间,俞凌杰等沿用周理等的过剩吸附量和绝对吸附量关系式,发表了多篇论文。通过本文的研究,认为过剩吸附量和绝对吸附量是两个缺少物理定义和使用价值的伪名词,两者之间的关系式也是不正确的。利用过剩吸附量和绝对吸附量的关系式根本得不到等温吸附量、等温累积吸附量和等温饱和吸附量。     

Assembled Plasmonic Asymmetric Heterodimers with Tailorable Chiroptical Response

Directed nanocrystal (NC) heteroassemblies could potentially achieve tailorable multiplex circular dichroism (CD) bands. Here, for the first time, we developed assembly of nanoparticle (NP)‐nanorod (NR) chiral heterodimers with chiral molecules to explore their chiroptical activities. The experimental results revealed that plasmonic CD responses were in the region from 520 to 750 nm, which was in agreement with the theoretical simulation. Importantly, the CD band could be regulated by controlling the gaps between adjacent NCs and altering the building blocks of the assemblies. These results show that the plasmonic chiroptical response of NP‐NR heterodimers could come from the finger‐crossed chiral construction of adjacent NC in the heterodimers and the formation of plasmonic hot‐spots in the assemblies could further enhance the plasmonic CD. This work provides a new opportunity to create heterogeneous nanoscale plasmonic objects with tailorable chiroptical response for application in biosensors, in vivo chiral medical carriers and negative refractive index materials.     

Photoactive Conjugated Polymer-Based Hybrid Biosystems for Enhancing Cyanobacterial Photosynthesis and Regulating Redox State of Protein

Constructing artificial hybrid biosystems, comprising of organisms and organic non-biological functional material, will afford promising opportunities to achieve brand new or enhanced functions. In this work, a hybrid biosystem is designed and constructed by electrostatically recombining photoactive cationic poly(fluorene-co-phenylene) derivative (PFP) with a cyanobacterium (Synechococcus sp. PCC7942, Syne) for enhancing its photosynthesis and regulating exogenous redox state of protein. The light utility efficiency of Syne is significantly improved assisted by the excellent ultraviolet light-harvesting ability of PFP, which accelerates electron-transfer rate in non-cyclic electron transport chain, and further augments the light-dependent reaction in photosynthesis. As a result, O₂, NADPH, and ATP production in the light-dependent reaction are increased by 52.8%, 47.9%, and 27.2%, respectively. Moreover, the extracellular electron transfer property of Syne is able to realize electronic communication with external circumstances. Specifically, the electrons exported from Syne can reduce exogenous oxidized cytochrome c (Cyt c) and adsorbed PFP has the ability to regulate the reduction degree of Syne to Cyt c. This work reports an ideal design of a conjugated polymer-based hybrid biosystem, providing a strategy to promote photosynthesis and regulate the redox state of protein.     

煤矸石燃烧过程中汞的释放规律及其动力学研究

我国煤矸石电厂的装机量已达30 000 MW,煤矸石电厂排放的汞对环境造成的污染不容忽视。为了建立和完善汞控制技术的理论基础,对煤矸石燃烧过程中汞的释放规律及其动力学进行了系统研究,结果表明：随着层燃温度的升高和停留时间的延长,煤矸石中汞的释放率逐渐增大;汞释放规律符合一级动力学方程,1^#、2^#煤矸石中汞释放反应的活化能E分别为25.25、18.77 kJ/mol,频率因子A分别为0.796、0.189 min^-1。