面发射分布反馈半导体激光器

本文详细阐述了面发射分布反馈半导体激光器(SE-DFB-LD)的基本工作原理、结构设计及其工作性能,针对国内外研究最新进展与发展现状进行了总结和评述,并在此基础上,对面发射半导体激光器的研究工作和发展趋势做出了进一步的讨论和展望。随着面发射分布反馈半导体激光器各性能指标的不断优化提升和后期加工、装调技术的逐渐成熟,其将不断满足科学研究及工业、军事等实际应用领域对半导体激光器的需求,具有很大的发展潜力。     

The effects of aircraft on climate and pollution. Part I: Numerical methods for treating the subgrid evolution of discrete size- and composition-resolved contrails from all commercial flights worldwide

This paper provides and evaluates mass conservative, positive-definite, unconditionally-stable, and non-iterative numerical techniques for simulating the evolution of discrete, size- and composition-resolved aerosol and contrail particles in individual aircraft exhaust plumes in a global or regional 3-D atmospheric model and coupling the subgrid exhaust plume information to the grid scale. Such treatment represents a new method of simulating the effects of aircraft on climate, contrails, and atmospheric composition. Microphysical processes solved within each plume include size-resolved coagulation among and between aerosol and contrail particles and their inclusions, aerosol-to-hydrometeor particle ice and liquid nucleation, deposition/sublimation, and condensation/evaporation. Each plume has its own emission and supersaturation, and the spreading and shearing of each plume’s cross-section are calculated as a function of time. Aerosol- and contrail-particle core compositions are tracked for each size and affect optical properties in each plume. When line contrails sublimate/evaporate, their size- and composition-resolved aerosol cores and water vapor are added to the grid scale where they affect large-scale clouds. Algorithm properties are analyzed, and the end-result model is evaluated against in situ and satellite data.     

医学物理学“课程思政”建设及课堂融合探究

课程思政融入教学是我国各类高校教学改革的必然趋势,从而达到培养高素质人才的目的.加快课程思政进校园,创新课程思政教学方法,教师的作用不可或缺.医学物理融入"思政元素"具有先天的融合优势.从医学物理教学现状出发,探索课程思政有效融入教学的方法和手段,总结经验和不足,力求将医学物理学课程与思政教育同向同行,把思想政治工作贯穿教育教学全过程.     

结构振动和声辐射的可控性和可观性指标

结构振动和声辐射的可控性和可观性指标对有源控制系统作动器/传感器的布置具有重要意义。对结构振动和声辐射的可控性和可观性指标进行了研究,提出了基于声压输出的振动模态可观性指标,在振动模态可控性和可观性指标的基础上,结合振动模态的声辐射效率,提出了结构声辐射的可控性和可观性指标和基于声压输出的可观性指标。以板结构为例,对结构振动和声辐射的可控性和可观性指标进行了计算分析和讨论,比较了基于声压输出和基于振动响应输出的振动模态可观性,重点研究了基于声压输出的振动模态可观性和结构振动及声辐射的可观性特点,最后对指标值在结构声有源控制中输入(输出)位置选择上的应用进行了讨论和比较,通过数值仿真对指标的有效性进行了验证。      

天然气一步法制乙烯工艺的多联产系统

本文对UCCPT公司的OCM(Oxidative Coupling of Methane,一步法制乙烯)工艺以及O2-CO2燃气蒸汽联合动力工艺进行了模拟计算与分析,提出了一个集乙烯生产与动力输出为一体的多联产工艺.在乙烯产率和净输出电功相同的情况下,相对于单独生产烯烃的OCM工艺和O2-CO2动力系统,新工艺的天然气与氧气消耗量的减少率分别为4.3%和3.2%;电、蒸汽和冷却水的消耗减少率分别为6.1%、100%和9.9%.     

氧化锌量子点和碳量子点及其复合物的制备与发光性能的研究

采用溶胶凝胶方法和水热法制备了水溶性荧光氧化锌量子点(Zn O-QDs)和碳量子点(C-QDs),其量子效率分别达到38%和61%。基于所合成的Zn O-QDs和C-QDs制备了氧化锌和碳量子点复合物(Zn O/CQDs),并分别对其发光特性进行了研究。透射电镜(TEM)图像表明,所合成的Zn O-QDs和碳量子点尺寸分布在3~6 nm之间,分散均匀。光致发光光谱表明,Zn O-QDs和碳量子点的发光峰中心分别位于540 nm和450 nm,两者发光峰的最佳激发波长为370 nm和350 nm。通过调整Zn O-QDs和C-QDs的体积比,所制备的Zn O/C-QDs能够实现荧光光谱的连续可调,并产生了白色荧光。     

陕北侏罗纪富镜煤和富惰煤分子结构的FTIR，XPS和13C NMR表征

侏罗纪优质煤炭资源为煤制油、制气等清洁高效利用提供了丰富的物质基础,其显微组分以富集惰质组为特征,而镜质组与惰质组大分子结构在很大程度上决定了煤的物理化学性质和工艺性能,进而决定了煤炭资源的综合利用效率及附加值。采集并制备了陕北侏罗纪煤田小保当煤矿和柠条塔煤矿的原煤(XR)、富镜质组煤(XV、NV)和富惰质组煤(XI、NI)样品,利用傅里叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)、固体13C核磁共振谱(13C NMR)等手段,结合煤质分析结果,定量表征了不同显微组分富集物分子结构的差异。研究结果表明：XI和NI煤中芳烃结构芳环取代程度低,主要以3个相邻、4~5个相邻的氢原子形式存在,苯环上氢原子较少被其他官能团取代,同时其结构中芳烃C═C骨架振动明显,脂肪结构中亚甲基伸缩振动强度较低,并且甲基含量略高于富镜煤,C═O基团相对含量略高,表明富惰煤有较多含氧桥键相连的芳香结构,其结构中脂族链、脂环基团脱落、断裂以及芳烃富集,支链相对较少且长度较短,芳碳率、芳香度、芳环缩合程度及成熟度较高。XV和NV煤中表面结构中碳的赋存形态“C—C,C—H”,“C—O”的相对含量高于富惰煤,反映其结构中应含较多的芳环取代的脂肪族侧链,XI和NI煤表面结构中氧的赋存形态以“C—O”为主,“C═O”和“COO—”明显高于富镜煤。XV和XI煤的芳碳率分别为57.91%和66.02%,脂甲基碳分别为10.02%和7.84%,质子化芳碳为非质子化芳碳的两倍,XV煤的羰基和羧基碳相对含量较高,两者桥碳和周碳之比分别为0.25和0.40,芳香核结构平均缩合环数分别为2.68和3.03,平均尺寸分别为0.448和0.676 nm,XI煤结构中芳香核以萘和蒽为主,支链化度L_γ分别为0.22和0.19,表明XV比XI存在较多脂肪侧链、饱和环结构,生烃(油)潜力大。     

地黄饮湿法提取与煎煮法提取效率的比较

以地黄饮中两味君药山茱萸肉及肉苁蓉的主要成分马钱苷、松果菊苷的提出量及出膏率为指标,对湿法粉碎提取法与煎煮法的提取效率进行了比较研究。结果显示,湿法粉碎提取法所得马钱苷、松果菊苷的量、出膏量较煎煮明显提高。湿法粉碎提取法提取效率高,方法简便,时间短,可用于地黄饮提取。     

13th annual meeting of the als users' association

The Interdisciplinary Consortium for Research and Educational Access in Science and Engineering (INCREASE) promotes competitive research and education in Historically Black Colleges and Universities (HBCUs) and other Minority-Serving Institutions (MSIs). Founded in 2007 and based at Hampton University in Virginia (USA), the consortium is increasing MSI faculty utilization of national user facilities and facilitating education and research training, especially for members of groups underrepresented in science and engineering research at national facilities, such as African-Americans, Hispanics, and women. INCREASE is a multi-campus and interdisciplinary consortium including more than 40 science and engineering faculty participants from over 30 MSIs and other strategic university partners to facilitate access to world-class facilities so that faculty members can conduct cutting-edge science.     

Orientation relationships of martensite variants determined by electron backscatter diffraction

Orientation relationships between the parent phase and 2H type martensite, and between different variants in a plate group of martensite in the CuAlNi shape memory alloy were determined by electron backscatter diffraction. The result reveals clearly that the basal planes of different correspondence variants of the 2H martensite originate from different 110P planes of the parent phase, and the [010]2H axis of each correspondence variant originates from one of the <001>P axes of the parent phase. Our result reveals also the typical relationships of four habit-variants A, B, C and D in a martensite plate group, and that the habit-variants A and C (and equivalenty B and D) are twin-related by an 1212H mirror plane, and the habit-variants A and D (and B and C) are twin-related by an 1012H mirror plane. Usually, variants A and C (and B and D) form spear morphology and variants A and D (and B and C) form fork morphology.     

不同比例有机无机肥配施土壤腐殖质组分的光谱学特征

以16年长期定位试验为基础,探讨不同比例有机无机肥配施对土壤腐殖质特征的影响。通过分离纯化腐殖质中的胡敏酸（HA）和富里酸（FA）组分,并利用元素分析、红外光谱和核磁共振研究分析了F1（70%化肥+30%有机肥）、F2（50%有机肥+50%化肥）和F3（100%有机肥）三种施肥方式下的HA和FA含量及结构变化。结果表明,F3对于提升HA和FA含量的效果优于F1和F2处理,说明有机肥的施用量越高,土壤腐殖质组分的含量就越高。元素分析表明,不同配比的有机无机肥对HA和FA各元素含量及原子比影响不同。F2和F3都提高了HA的缩合度,降低了氧化度和极性,其中F3的效果更加明显;有机肥的施用还能促进HA中含氮化合物的形成,并且在F2中的效果最好;有机肥的施用同样提高了FA的缩合度而降低了氧化度和极性并促进了含氮化合物的形成,尤其在F2处理中尤为明显。腐殖质红外光谱分析表明,与F1相比,F2和F3提高了HA中脂肪族化合物、碳水化合物物质的含量,FA的羧基基团、脂肪基团含量也增加,且在F3处理中表现最为显著;F2处理则降低了HA中脂肪烃物质的含量,FA中的碳水化合物则达到最高。13C核磁共振波谱分析显示,在三种处理中,有机肥的施用提高了HA和FA的脂化度而降低其芳化度,其中F2处理中HA官能团变化更加显著,FA在F3处理中则变化更加明显。综上所述,有机肥显著提高了土壤腐殖质组分含量,并且提高了HA和FA的脂化度降低其芳化度,但是不同用量有机肥下HA和FA的形成机制不同。     

Some problems of analysis and optimization of plates and shells

The classical optimization problems of plates and shells to satisfy a priori given geometry and dynamical characteristics are considered. Orthotropic plates and shells with variable thickness and low transverse stiffness are analyzed. First, some useful theorems and their proofs are given. Then the finite approximation of the problem related to optimization of free vibrations of shells with transverse deformation and rotary inertia is discussed. The varational iteration (MVI) and Bubnov-Galerkin (MB) methods are applied, and their convergence and suitability for application to plates and shells analysis are discussed and numerically evaluated.     

镧和铕与邻菲罗啉谷氨酸配合物的NMR和IR研究

合成了稀土镧和铕与谷氨酸，邻菲罗啉形成的二元及三元配合物，经元素分析确定该配合物的组成为Ｌｎ（ｐｈｅｎ）（Ｇｌｕ）３．７Ｈ２Ｏ（Ｌｎ＝Ｌａ，Ｅｕ）；Ｅｕ（Ｇｌｕ）３；１２Ｈ２Ｏ。用核磁共振和红外光谱研究与配体与稀土离子的配位方式，讨论了稀土离子的顺磁性及屏蔽效应对配合物的ＮＭＲ谱图的影响。     

Z箍缩和闪光照相用快脉冲功率源技术的发展

 Z箍缩和闪光照相在惯性约束聚变（ICF）、核辐射效应和高性能爆轰流体动力学等研究中具有重要应用,Z箍缩ICF和多脉冲多角度高能脉冲X射线闪光照相对脉冲功率源提出了巨大挑战,国际上正在积极发展和探索可实现直接驱动Z箍缩和闪光照相二极管的快脉冲功率源新技术。综述了国际上近年来快Marx发生器（FMG）和快直线型变压器（FLTD）等脉冲功率源方面的发展动态,初步分析了两种技术途径的优缺点和制约性因素,以及需要开展的关键技术,介绍了西北核技术研究所的相关研究进展,最后提出了几点看法和建议。     

NIR Spectroscopy and Imaging Techniques for Evaluation of Fish Quality—A Review

Abstract

Fish is a highly perishable product and it is particularly important to pay attention to its quality changes. Maintenance of the high quality of fish and fishery products necessitates development of means for precise and rapid quality evaluation. Near-infrared (NIR) spectroscopy and imaging techniques are proven technologies that can provide useful information for the estimation of quality attributes in fish and fishery products due to fast speed, noninvasiveness, ease of use, and minimal sample preparation. The aim of this review is to communicate perspectives and aspects relating to NIR spectroscopy and imaging techniques with regard to evaluation of chemical composition (fat, protein, and moisture), microbiological (freshness, spoilage, and nematodes), and sensory (flavor, texture, and color) attributes of fish and fishery products. Moreover, the usefulness of NIR spectroscopy and imaging techniques for fish authentication and classification are presented. Finally, some viewpoints on the current situation and suggestions for future research directions are proposed.     

轻质萃取剂的分散液液微萃取-石墨炉原子吸收光谱法测定生活用水中痕量Pb与Cd

以轻质溶剂辛醇为萃取剂,建立了分散液液微萃取-石墨炉原子吸收光谱分析法(LDS-DLLME-GFAAS),并应用于生活用水中痕量Pb及Cd的测定。在分散液液微萃取(DLLME)中,以二乙基二硫代氨基甲酸盐(DDTC)为螯合剂,用微量注射器将辛醇和甲醇的混合溶液快速注入到样品溶液中发生雾化分散现象,Pb2+和Cd2+与DDTC的络合物被萃取到辛醇微滴中。离心分离后,以GFAAS测定萃取至上层辛醇相中的分析物。实验考察了萃取剂种类和体积、分散剂种类和体积、pH、DDTC浓度、萃取时间等影响萃取效率的实验参数。在最优实验条件下,Pb和Cd的检出限分别为0.15和0.03 μg·L-1,富集倍数分别为87和48,具有良好的线性和精密度。该分析方法优势在于操作简便,快速,低成本,高富集倍数,萃取剂用量少,已成功应用于自来水、饮用水和南湖水中痕量Pb和Cd的检测。     

拉曼光谱在油气地质应用中的研究进展

拉曼光谱具有简单、快速、原位、微区、无损、高分辨率和高灵敏度等优点,可以分析物质的成分与分子结构信息,是开展地质研究的有力工具。通过回顾近年来拉曼光谱的研究进展,结合实际的油气地质研究工作及分析测试经验,对拉曼光谱在油气地质研究中的应用进行总结,并讨论现阶段应用过程中存在问题及未来的发展方向。拉曼光谱在油气地质中的应用主要分为三个方面：（1）矿物与流体包裹体分析,可以确定成岩-成藏流体类型及组成、成岩-成藏作用过程,包括岩矿鉴定、流体包裹体中流体体系分析、水-岩相互作用过程研究、地质样品同位素研究等;（2）不同类型有机质成熟度分析,可以用于恢复热史、油气成藏期次约束;（3）流体包裹体压力恢复,可以研究油气藏的形成与演化过程。主要方式为利用流体包裹体中气体的拉曼特征峰位移变化量、气体溶解度恢复流体包裹体内压及捕获压力。在实际油气地质研究中,多种因素制约拉曼光谱的定量/半定量应用,主要包括：地质样品复杂性与特殊性、样品处理方式、拉曼测试参数与测试环境、拉曼光谱数据处理与分析方式。拉曼光谱分析测试流程标准化、挑选和制备校准标样;拉曼光谱与冷热台、水热金刚石压腔（HDAC）、高压可视反应腔（HPOC）、扫描电镜（SEM）、电子探针（EPMA）等仪器联用,开展复杂体系原位、实时、不同温压条件下测试,是进一步将拉曼光谱应用到油气地质中的研究方向。     

钾硼胁迫对棉花功能叶物质成分影响的FTIR表征

钾和硼均是植物必需的营养元素,对植物的生长、发育与生理代谢等起着重要作用。棉花对钾和硼都有较高的需求量,而棉花缺钾或缺硼时有发生。以鄂抗8号品种的棉花作为研究材料,利用傅里叶变换探讨钾硼胁迫对棉花功能叶片物质成分的影响。红外光谱(FTIR)对钾硼胁迫下棉花叶片的物质成分进行研究,分析钾硼缺乏情况下叶片红外光谱的差异。结果表明：(1)缺钾处理时,1 546.86, 1 438.85, 1 153.39和1 024.17 cm-1这4个特征峰消失,且其他特征峰的相对吸光度值与正常处理相比均减小,表明缺钾时棉花功能叶片蛋白质、纤维素、可溶性糖和核糖的结构发生变化且含量降低。(2)缺硼条件下,叶片的特征峰的相对吸光度均有所升高,因而,缺硼则导致蛋白质及可溶性糖、纤维素等碳水化合物等的运输受阻而在叶片中积累。(3)钾硼同时缺乏,棉花功能叶片特征峰的位置和相对吸收强度与正常处理相比有很大差异,表现为棉花功能叶片蛋白质和可溶性糖等碳水化合物的含量升高,而核酸和多糖分子等含量下降。因此缺钾导致棉花功能叶片蛋白质、纤维素、可溶性糖和核糖结构变化的含量降低;缺硼时蛋白质及可溶性糖、纤维素等碳水化合物等在叶片中积累;缺钾缺硼时蛋白质和可溶性糖等碳水化合物含量升高,而核酸和多糖分子等含量下降。     

Numerical simulations of type-III solar radio bursts

The first numerical simulations are presented for type-III solar radio bursts in the inhomogeneous solar corona and interplanetary space, that include microscale quasilinear and nonlinear processes, intermediate-scale driven ambient density fluctuations, and large scale evolution of electron beams, Langmuir and ion sound waves, and fundamental and harmonic electromagnetic emission. Bidirectional coronal emission is asymmetric between the upward and downward directions, and harmonic emission dominates fundamental emission. In interplanetary space, fundamental and/or harmonic emission can be important. Langmuir and ion sound waves are bursty and the statistics of Langmuir wave energy agree well with the predictions of stochastic growth theory.     

Surface chemistry of nanodiamonds

The experimental data available in the literature and the results obtained by the author in research into the structure of nanodiamonds and the physicochemical and chemical properties of their surface are generalized. An account is given of the problems concerning the chemical state and modification of the nanodiamond surface in gaseous and liquid media and the infiuence of modification on the sorption and catalytic properties of nanodiamonds, their compactibility, and sintering. The similarity and difference in the behavior of nanodiamonds and diamond macrocrystals in oxidation processes are discussed. The activation energies of oxidation of nanodiamonds by different reagents are determined in the absence and presence of catalysts.