激光惯性约束聚变中光学汤姆逊散射研究进展

当前,激光惯性约束聚变在越来越接近点火的极端能量密度条件下,实验与模拟的偏离逐渐增大,一个关键原因是缺乏对黑腔等离子体状态及其影响黑腔能量学和内爆对称性的细致研究和判断。光学汤姆逊散射主动式、诊断精确、参数完备的优点,使之成为激光惯性约束聚变黑腔等离子体状态参数精密诊断的标准方法。中国面向激光惯性约束聚变研究的光学汤姆逊散射实验技术的发展与神光系列激光装置的建设和在其上开展的物理实验紧密相关。近年来,四倍频汤姆逊散射实验技术在神光III原型和100 kJ激光装置上相继建立,部分实验结果不仅加深了对激光惯性约束聚变靶物理的认识,还反映了实验条件对汤姆逊散射诊断的影响,促进了实验技术的精密化发展。在未来,还需要进一步发展多支路汤姆逊散射、五倍频汤姆逊散射和超热相干汤姆逊散射等新技术,面向点火黑腔条件,大幅提升激光等离子体状态参数的诊断精度,开展新物理机制的探索和研究,在激光惯性约束聚变和其他高能量密度物理科学领域发挥更重要的作用。     

紫外熔石英元件高精度低缺陷控形控性制造技术研究进展

传统的紫外熔石英元件加工方法本身会引入各类制造缺陷,需要后期加工来消除前期加工带来的缺陷,限制了熔石英元件的加工 质量和加工效率。针对这些问题,课题组提出了采用磁流变、离子束、保形光顺和流体动压抛光等可控柔体加工技术提升熔石英元件的加工效果,并开展了相关研究。主要介绍了课题组在关键技术上取得的重要进展,包括亚纳米精度表面控形制造技术、纳米精度本征表面控性生成方法、熔石英元件高精度低缺陷组合工艺与设备等一系列关键技术。通过探讨关键技术及其发展现状,为未来紫外熔石英元件高精度低缺陷制造技术的发展提供参考。     

Semiconductor Emitters in Entropy Sources for Quantum Random Number Generation

Random number generation (RNG) is needed for a myriad of applications ranging from secure communication encryption to numerical simulations to sports and games. However, generating truly random numbers can be elusive. Pseudorandom bit generation using computer algorithms provides a high random bit generation rate. Nevertheless, the reliance on predefined algorithms makes it deterministic and predictable once initial conditions are known. Relying on physical phenomena (such as measuring electrical noise or even rolling dice) can achieve a less predictable sequence of bits. Furthermore, if the physical phenomena originate from quantum effects, they can be truly random and completely unpredictable due to quantum indeterminacy. Traditionally, physical RNG is significantly slower than pseudorandom techniques. To meet the demand for high-speed RNG with perfect unpredictability, semiconductor light sources are adopted as parts of the sources of randomness, i.e., entropy sources, in quantum RNG (QRNG) systems. The high speed of their noise, the high efficiency, and the small scale of these devices make them ideal for chip-scale QRNG. Here, the applications and recent advances of QRNG are reviewed using semiconductor emitters. Finally, the performance of these emitters is compared and discuss their potential in future technologies.     

Noncommutative geometry and conformal geometry. III. Vafa–Witten inequality and Poincaré duality

This paper is the third part of a series of papers whose aim is to use the framework of twisted spectral triples to study conformal geometry from a noncommutative geometric viewpoint. In this paper we reformulate the inequality of Vafa–Witten [42] in the setting of twisted spectral triples. This involves a notion of Poincaré duality for twisted spectral triples. Our main results have various consequences. In particular, we obtain a version in conformal geometry of the original inequality of Vafa–Witten, in the sense of an explicit control of the Vafa–Witten bound under conformal changes of metrics. This result has several noncommutative manifestations for conformal deformations of ordinary spectral triples, spectral triples associated with conformal weights on noncommutative tori, and spectral triples associated with duals of torsion-free discrete cocompact subgroups satisfying the Baum–Connes conjecture.     

Synthesis and bioevaluation of radioiodated nitroimidazole-based hypoxia imaging agents containing different charged substituents

Journal of Radioanalytical and Nuclear Chemistry - In this work, a series of radiolabeled 2-nitroimidazole-based iodotriazoles containing positively charged, negatively charged, or neutral...     

Adaptive registration of diffusion tensor images on lie groups

With diffusion tensor imaging (DTI), more exquisite information on tissue microstructure is provided for medical image processing. In this paper, we present a locally adaptive topology preserving method for DTI registration on Lie groups. The method aims to obtain more plausible diffeomorphisms for spatial transformations via accurate approximation for the local tangent space on the Lie group manifold. In order to capture an exact geometric structure of the Lie group, the local linear approximation is efficiently optimized by using the adaptive selection of the local neighborhood sizes on the given set of data points. Furthermore, numerical comparative experiments are conducted on both synthetic data and real DTI data to demonstrate that the proposed method yields a higher degree of topology preservation on a dense deformation tensor field while improving the registration accuracy.     

Stabilization of the Closed-Ring Isomer of Spiropyran by Amide Naphthotube in Water and Its Application in Naked-Eye Detection of Toxic Paraoxon

The thermodynamically unstable, colourless closed-ring isomer of spiropyran can be stabilized in water by the anti-configurational isomer of amide naphthotube. The influence of the binding on the thermodynamics and kinetics of spiropyran have been studied. The complex was further used to prepare a test paper that allows naked-eye detection of toxic paraoxon.     

AlGaN基宽禁带半导体光电材料与器件

AlGaN基材料是带隙可调的直接带隙宽禁带半导体材料,是制备紫外(UV)光电子器件的理想材料.经过数十年的研究,目前已经在异质衬底外延生长AlGaN基材料、高效掺杂等方面取得了巨大进展.以此为基础,AlGaN基紫外光电器件制备领域也得到长足发展.在本综述中,主要介绍了高质量AlGaN基材料的MOCVD外延生长方法、掺杂方法以及近年来在紫外发光、紫外探测器件方面取得的进展.     

Long-term follow-up analysis of zolpidem in fingernails after a single oral dose

The determination of xenobiotics in keratinized matrices, such as nails and hair, has received considerable attention because of the relatively long detection window for compounds. The distribution of xenobiotics in fingernails, unlike hair, was equivocal. The main aim of this study was to use follow-up surveys to measure zolpidem profiles in nails after subjects consumed a single dose of the drug. In addition, the zolpidem concentrations in nails were compared with data for different biosamples, such as hair and blood from previous work. With these preconditions, a high-performance liquid chromatography–tandem mass spectrometry method was developed and validated for the determination of zolpidem in nails. Nails underwent alkaline hydrolysis and were extracted with diethyl ether. A Capcell Pak C18 MGII column was used to separate the target compound, and an API 4000 Qtrap mass spectrometer was used as a detector. The results for nail samples from seven subjects who had taken a single 10 mg zolpidem dose were significant: two relatively high zolpidem concentrations were observed in the long-term follow-up analysis of nails. The zolpidem concentration was less than 1.74 pg/mg and less than 3.29 pg/mg in fingernails and toenails, respectively. The subsequent peak concentration of zolpidem was observed between 10 and 15 weeks after each subject took a single dose of the drug. This result suggested that the germinal matrix area was a primary in vivo pathway for zolpidem secretion into the nail. The analysis of biosamples, such as nails, may be a useful adjunct to conventional methods of drug testing and hair analysis. Further research is needed concerning the contamination risk in analysis of nail biosamples.