Pr3+离子在氟化物玻璃中的光跃迁的计算与分析

测量了Pr(0.5):ZBLAN非晶的吸收光谱,由此利用Judd-Ofelt理论计算了Pr3 离子在材料中的光谱跃迁强度参量,讨论Judd-Ofelt理论在计算Pr3 离子的强度参数时存在的问题.从所得到的强度参数计算预言了此材料中Pr3 离子的各能级之间的自发辐射跃迁速率、荧光分支比和积分发射截面,由所得结果讨论了该材料作为激光材料的前景及可能存在的光子雪崩上转换机制.     

星载太阳紫外光谱监视器的地面辐射定标

星载太阳紫外光谱监视器是一种小型化、高精度紫外-真空紫外光谱辐射计,它有两种工作模式,即探测太阳紫外光谱辐照度的太阳模式和探测大气的太阳后向散射紫外光谱辐亮度的大气模式。对应这两种工作模式分别建立了紫外-真空紫外光谱辐照度和紫外光谱辐亮度定标装置。光谱辐照度标准灯直接辐照仪器的漫反射板进行仪器的光谱辐照度响应度定标,光谱辐照度标准灯辐照标准漫反射板形成朗伯面光源进行仪器的光谱辐亮度响应度定标。误差分析表明:160~250 nm光谱辐照度绝对定标误差为6.5%,250~400 nm为4.3%;250~400 nm光谱辐亮度绝对定标误差为5.9%。星载太阳紫外光谱监视器获得的地外太阳紫外光谱辐照度与大气的太阳后向散射光谱辐亮度数据,同国际上的观测结果相比一致性达±10%。     

苯快速反应点火特性的光谱研究

利用由单色谱仪、压力传感器以及示波器组成的测试系统, 测定了高温激波管中苯快速反应的几个重要产物：H,C₂和CH的点火延迟时间和出现的顺序。提出了一种在入射激波条件下确定含能材料冲击点火延迟时间的新方法,并介绍了苯在快速反应中碳生成的微观反应机理。 研究表明: 无论马赫数如何改变,H原子总是最先出现,说明苯在快速反应过程中,首先断裂的C—H键,而不是C—C键。利用较早出现的反应中间产物H原子来测定苯的点火延迟时间更为准确。利用单色谱仪技术能较好地研究苯的快速反应点火特性,新方法与国内外常用的全色光技术相比可明显减少实验量。     

自全国各地100多位理事Road Machinery Branch of China Highway and Transportation Society He

In this paper, a three dimensional ratio-dependent chemostat model with periodically pulsed input is considered. By using the discrete dynamical system determined by the stroboscopic map and Floquet theorem, an exact periodic solution with positive concentrations of substrate and predator in the absence of prey is obtained. When β is less than some critical value the boundary periodic solution (xs(t), 0, zs(t)) is locally stable, and when β is larger than the critical value there are periodic oscillations in substrate, prey and predator. Increasing the impulsive period τ, the system undergoes a series of period-doubling bifurcation leading to chaos, which implies that the dynamical behaviors of the periodically pulsed ratio-dependent predator-prey ecosystem are very complex.     

Analysis of Vicinal Water in Soft Contact Lenses Using a Combination of Infrared Absorption Spectroscopy and Multivariate Curve Resolution

In this paper, we propose a new spectroscopic method to explore the behavior of molecules near polymeric molecular networks of water-containing soft materials such as hydrogels. We demonstrate the analysis of hydrogen bonding states of water in the vicinity of hydrogels (soft contact lenses). In this method, we apply force to hydrated contact lenses to deform them and to modulate the ratio between the signals from bulk and vicinal regions. We then collect spectra at different forces. Finally, we extracted the spectra of the vicinal region using the multivariate curve resolution-alternating least square (MCR-ALS) method. We report the hydration states depending on the chemical structures of hydrogels constituting the contact lenses.     

Ameliorating the interfacial issues of all-solid-state lithium metal batteries by constructing polymer/inorganic composite electrolyte

Lithium metal is one of the most promising anodes for next-generation batteries due to its high capacity and low reduction potential.However,the notorious Li de...     

Cytosolic escape of mitochondrial DNA triggers cGAS-STING-NLRP3 axis-dependent nucleus pulposus cell pyroptosis

Low back pain (LBP) is a major musculoskeletal disorder and the socioeconomic problem with a high prevalence that mainly involves intervertebral disc (IVD) degeneration, characterized by progressive nucleus pulposus (NP) cell death and the development of an inflammatory microenvironment in NP tissue. Excessively accumulated cytosolic DNA acts as a damage-associated molecular pattern (DAMP) that is monitored by the cGAS-STING axis to trigger the immune response in many degenerative diseases. NLRP3 inflammasome-dependent pyroptosis is a type of inflammatory programmed death that promotes a chronic inflammatory response and tissue degeneration. However, the relationship between the cGAS-STING axis and NLRP3 inflammasome-induced pyroptosis in the pathogenesis of IVD degeneration remains unclear. Here, we used magnetic resonance imaging (MRI) and histopathology to demonstrate that cGAS, STING, and NLRP3 are associated with the degree of IVD degeneration. Oxidative stress induced cGAS-STING axis activation and NLRP3 inflammasome-mediated pyroptosis in a STING-dependent manner in human NP cells. Interestingly, the canonical morphological and functional characteristics of mitochondrial permeability transition pore (mPTP) opening with the cytosolic escape of mitochondrial DNA (mtDNA) were observed in human NP cells under oxidative stress. Furthermore, the administration of a specific pharmacological inhibitor of mPTP and self-mtDNA cytosolic leakage effectively reduced NLRP3 inflammasome-mediated pyroptotic NP cell death and microenvironmental inflammation in vitro and degenerative progression in a rat disc needle puncture model. Collectively, these data highlight the critical roles of the cGAS-STING-NLRP3 axis and pyroptosis in the progression of IVD degeneration and provide promising therapeutic approaches for discogenic LBP.Subject terms: Cell death, Diseases     

一类随机环境中的随机游动

研究了在环境平稳遍历时,右半直线上可逗留的随机环境中的随机游动的常返性和非常返性,给出非常返、正常返、零常返的充要条件,并讨论了极限性质.作为推论,给出P独立同分布时的相应结论.     

基于表面增强拉曼光谱技术的心肌生物标志物检测

心血管疾病(CVD)是全球最主要的死亡原因,急性心肌梗死(AMI)是心血管疾病致死的主要病因,安全快速地诊断AMI对于降低患者的死亡率至关重要。因常用的检测方法如心电图(ECG)缺乏足够的敏感性,寻找并针对AMI生物标志物开展高灵敏检测已成为早期检测AMI重要手段。心肌肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB)和肌红蛋白(Myo)是目前公认的检测AMI的重要心肌生物标志物。在过去的几十年里,许多生物传感器被开发出来用于检测心肌生物标志物,其中基于表面增强拉曼光谱(SERS)的心肌生物标志物检测技术迅速发展,并表现出独特的技术优势和广阔的应用前景。本文首先介绍了多种心肌生物标志物及其与AMI的关联,在此基础上概述主要的心肌生物标志物检测方法的原理、优势及局限性,重点介绍近年来新兴的SERS技术及其在心肌生物标志物传感方面的最新研究进展,并对该技术在AMI诊断方面的应用前景以及有待突破的瓶颈进行了讨论和展望。     

石墨基液流电池复合双极板

液流电池是一种安全性高、使用寿命长、可扩展的大规模储能系统,可以协助电网调峰储能,提高能源利用率,发展前景广阔。双极板是液流电池的重要组成部分。功能上起到了分隔、串联电池、传导电流、为电堆提供结构支撑等作用。从成本构成角度看,双极板的价格占电堆成本的比重也较大。开发高性能、低成本的双极板对加快液流电池的商业化应用具有重要意义,也是目前业界的迫切需求。虽然文献上报道了许多针对液流电池双极板开发的工作,但是目前高性能、低成本的液流电池双极板产品仍无法充分满足市场需求。本文着重介绍了石墨基复合双极板的研究现状,介绍了材料选择、工艺流程对关键性能的影响,对相关工作进行了评述,并为液流电池双极板的开发提出了建议。