Electro-optic modulation of AlGaN in deep ultraviolet

深紫外非线性光学材料在光信息处理和高速光通讯等领域具有广泛的应用前景，发展适宜工作在深紫外波段的新型非线性光学材料成为国际学术界和产业界研发的热点。AlGaN基半导体凭借宽带隙带来的信道容量大、纤锌矿晶格排列缺乏反演对称性造成的非线性光学效应、以及作为半导体可控制对n型p型的光电集成等优势，成为理想的深紫外波段非线性光学材料，在电光调制和电光开关等非线性光学器件方面极具应用潜力。本文理论设计并生长了高Al组分的AlxGa1-xN/GaN超晶格结构，通过椭圆偏振光谱表征测算AlxGa1-xN/GaN超晶格结构的电光系数，在极化场、外电场和共振效应多场调制下增强电光效应，为AlGaN非线性材料走向...Nonlinear optical materials operated in deep ultraviolet have potential applications in high speed optical telecommunications, which much interests the international academics. Due to the advantages of large channel capacity resulted from wide band gap, the nonlinear optical property induced by intrinsic crystallographic non-centro symmetry and electron energy band, and the controllable optoelectr...学位：工学硕士院系专业：物理科学与技术学院_微电子学与固体电子学学号：1982013115297

微小RNA-200a&c在改善广州管圆线虫诱导的Balb/c小鼠脱髓鞘性视神经炎中的作用

目的探讨过表达miRNA-200a&c后对广州管圆线虫诱导的Balb/c小鼠脱髓鞘性视神经炎的保护作用。方法选取2~3周SPF级Balb/c小鼠分成4组，即正常组，广州管圆线虫感染7 d、14 d、21 d组。分别记录不同时间分组小鼠的体质量及其生存情况，并对小鼠进行神经行为学评分及视觉评分。视觉诱发电位（VEP）检测不同时间分组小鼠视觉损伤情况。透射电镜观察不同时间分组小鼠眼球组织结构变化。广州管圆线虫感染第7天时通过立体定位注射向小鼠侧脑室注射miRNA-200a&c外源性类似物，同时将小鼠分为正常组，广州管圆线虫感染21 d组、广州管圆线虫感染+阴性对照（NC）组、广州管圆线虫感染+过表达miRNA-200a&c类似物组。VEP检测以上分组小鼠视觉损伤情况。透射电镜观察以上分组小鼠眼球组织结构变化。免疫荧光检测以上分组小鼠眼部视网膜神经节细胞（RGCs）及视神经少突胶质细胞（OLs）的数量变化。结果广州管圆线虫感染第21天，部分Balb/c小鼠眼睑完全闭合（32.52±4.67）%或出现眼球萎缩（15.79±3.23）%等现象，同时出现小鼠体质量下降（21 dpi：P＜0.05）和神志不清等表现，感染21 d组小鼠神经行为学评分明显降低，转棒实验时长缩短68%（21 dpi：P＜0.01），部分小鼠出现偏瘫而无法正常行走，甚至部分出现行动迟缓、共济失调、定向障碍；另外有部分小鼠出现刺激感觉反应迟钝，单侧视力缺失，视动反应阈值下降83%，视觉功能明显下降（21 dpi：P＜0.05）。VEP结果显示广州管圆线虫感染21 d时Balb/c小鼠潜伏期与正常组相比轻度延长（21 dpi：P＜0.05），且多为单侧眼部发病。过表达miRNA-200a&c后，与感染21 d组相比，VEP检测结果显示，P1波潜伏期明显缩短（P＜0.05）；透射电镜结显示视网膜神经节细胞胞质肿胀情况较感染21 d组对比有所减轻，视神经髓鞘结构较感染21 d组对比相对紧密，厚度也较均匀（P＜0.05）；免疫荧光结果显示RGCs和OLs数量较感染21 d组相比细胞数量明显升高且细胞排列紊乱的现象也有所改善（P＜0.05）。结论广州管圆线虫感染Balb/c小鼠后引起脱髓鞘性视神经炎，过表达miRNA-200a&c可减轻脱髓鞘性视神经炎造成的损伤，改善小鼠眼部损伤

Effect of plasticity on dynamic impact in a journal-bearing system: A planar case

Plasticity is inevitable during contact with a high load, and thus should be considered when simulating high-load contact. Plasticity during non-conformal contact has been well studied. However, no contact law that considers plasticity during conformal contact has been developed, even though such &quot;plastic conformal contact&quot; commonly occurs in journal-bearing systems under high loads. Herein, we constructed a plastic Winkle model of plastic conformal contact, and integrated it into a contact solver to simulate the impact dynamics of a single journal-bearing system. The plastic contact law was first verified by finite-element simulations, which were in good agreement with the plastic indentation observed during loading and unloading. To study the plasticity during conformal impact, we integrated the contact law into a dynamic-contact model of the single journal-bearing system. The results indicate that the energy dissipation due to plasticity was much greater than that from damping and friction. Ignoring plasticity may result in an unrealistic travel distance of the journal during impact. The developed model was used to construct a velocity map to determine whether or not that plasticity should be considered. (c) 2020 Elsevier Ltd. All rights reserved.</p

一种秸秆木炭制备的土壤扩蓄增容剂及其生产方法

本发明公开了一种秸秆木炭制备的土壤扩蓄增容剂，制得的该土壤扩蓄增容剂由以下原料及其重量百分比组成：秸秆木炭：10％、粘土：25％～30％、磷酸二氢钾：10％～20％、磷酸二铵：15％～20％、油菜渣：10％～15％、尿素： 1％～3％，高脂膜：1％～2％、作物混合秸秆：10％～18％。其制备方法先将秸秆木炭去杂，分级，经粉碎后研磨至1mm以下，过20目筛，与粘土混合，将辅料磷酸二氢钾，磷酸二铵，油菜渣，作物混合秸秆风干，分别粉碎并研磨至1mm以下，过20目筛，然后混合，搅拌均匀，经制粒、包装即得。每公顷施用750kg-1500kg。棉花等作物可增产10％以上，提高水分利用效率10％以上，在干旱半干旱地区，能充分利用天然降雨，保水保肥提高土壤肥力，有利于生态保护

湘江长潭株段河床沉积物重金属污染Pb同位素地球化学分析

湘江长沙-湘潭-株洲(简称"长潭株")段是湘江流域重金属污染最严重的河段。以往研究得到沉积物严重受Cd、Cu、Pb、Zn、Mn等多种重金属的污染。但河流沉积物是一个复杂的环境单元,其物质组成既是流域岩石风化的产物,又是人为作用的反映。且湘江流域基岩(如花岗岩等)、土壤等环境介质本身就存在Cd、Cu、Pb、Zn、As等重金属元素高背景值。加上城市工业活动等人为排放,使得沉积物重金属的来源复杂化。因此,认识沉积物重金属

一种建筑垃圾制备的土壤扩蓄增容剂及其生产方法

本发明公开了一种建筑垃圾制备的土壤扩蓄增容剂及其生产方法，土壤扩蓄增容剂由以下原料及重量百分比组成：建筑垃圾粉末：35％～45％、磷酸二氢钾：10％～20％、磷酸二铵：15％～20％、油菜渣：10％～15％、尿素：1％～ 3％，高脂膜：1％～2％、作物混合秸秆粉末：10％～18％。其制法是将建筑垃圾剔除金属、木屑、塑料杂物，分级，保留废弃砖块砂浆和泥土，经粉碎后研磨至1mm以下，过20目筛，将辅料磷酸二氢钾，磷酸二铵，油菜渣，作物混合秸秆粉末风干，分别粉碎并研磨至1mm以下，过20目筛，然后混合，搅拌，经制粒、包装即得。每公顷施用750kg-1500kg。对棉花作物可增产 12％以上，提高水分利用率10％以上，在干旱半干旱地区，能充分利用天然降雨，保水保肥提高土壤肥力，有利于生态保护

植物模式标本的考证与数字化:以中国国家植物标本馆为例

模式标本是最重要的植物标本,是确定植物学名的依据,是植物分类学家从事植物系统分类研究必不可少的科学材料,也是开展专科专属研究、编写国家或地方植物志、进行植物区系调查研究、开发利用和保护植物资源的重要基本资料。但模式标本的人为和自然毁损难以避免,模式标本及其标签信息的数字化使得模式标本的形态、地理分布、采集等主要信息得到最大限度的永久保存,可以极大地方便模式标本信息的共享,可以为科学研究人员或相关人员提供植物形态、地理分布、历史变迁等多方面的信息。本文以中国科学院植物研究所国家植物标本馆维管束植物模式标本数字化建设为例,详细介绍了规范化整理模式标本的方法、模式标本数字化的操作流程,并通过大量实例介绍了模式标本考订的过程、常见问题的处理方法等,以期为其他单位开展模式标本数字化建设提供经验

中国脑血管病临床管理指南（第2版）（节选）——第5章 脑出血临床管理 Chinese Stroke Association Guidelines for Clinical Management of Cerebrovascular Diseases (Second Edition) (Excerpt) ——Chapter Five Clinical Management of Intracerebral Hemorrhage

自发性脑出血是卒中的一种严重亚型，在中国卒中患者中占23.4%，以急性发病、病情迅速变化以及高致死和致残率为显著特点。鉴于管理脑出血所面临的紧迫和复杂挑战，本指南旨在为其临床处理提供系统性和全面性的推荐意见。本章节覆盖了从脑出血院前评估、医疗干预到二级预防和康复的各个关键环节。在具体推荐方面，本指南根据不同的证据等级，为早期诊断、影像学评估、急性期干预、内科和重症监护、外科干预以及二级预防策略提供了指导，旨在全面提升自发性脑出血诊疗的科学性和系统管理质量。 Abstract: Spontaneous intracerebral hemorrhage represents a severe subtype of stroke, accounting for approximately 23.4% of stroke cases in China. It is characterized by its rapid onset, swift disease progression, and high rates of mortality and disability. Given the urgency and complexity in managing intracerebral hemorrhage, this guideline aims to provide systematic and comprehensive recommendations for its clinical management. This chapter covers all key aspects ranging from pre-hospital evaluation and medical intervention to secondary prevention and rehabilitation. With respect to specific recommendations, this guideline offers exhaustive guidance based on varying levels of evidence for early diagnosis, imaging assessments, acute-phase interventions, medical and ICU management, surgical interventions, and secondary prevention strategies, with the ultimate aim of enhancing the scientific rigor and systematic quality of spontaneous intracerebral hemorrhage management

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors