Role of short-wavelength filtering lenses in delaying myopia progression and amelioration of asthenopia in juveniles

AIM： To evaluate the positive effects of blue-violet light filtering lenses in delaying myopia and relieving asthenopia in juveniles. METHODS： Sixty ametropia juveniles （aged range, 11-15y） were randomized into two groups： the test group （30 children, 60 eyes）, wearing blue-violet light filtering lenses; and the control group （30 children, 60 eyes）, wearing ordinary aspherical lenses. Baseline refractive power of the affected eyes and axial length of the two groups was recorded. After 1-year, the patients underwent contrast sensitivity （glare and non-glare under bright and dark conditions）, accommodation-related testing, asthenopia questionnaire assessment, and adverse reaction questionnaire assessment. RESULTS： After ly of wearing the filtering lenses, changes in refractive power and axial length were not significantly different between the two groups （P〉0.05）. Under bright conditions, the contrast sensitivities at low and medium- frequency grating （vision angles of 6.3, 4.0, and 2.5） with glare in the test group were significantly higher than in the control group （P〈0.05）, while the contrast sensitivity at low-frequency grating （vision angles of 6.3 and 4.0） in the absence of glare in the test group was higher than in the control group （P〈0.05）. Under glare and non-glare dark conditions, the contrast sensitivities of various frequencies in the test group did not show significant differences compared with those in the control group （P〉0.05）. In the test group, the amplitude of accommodation, accommodative lag, and accommodative sensitivity of patients wearing glasses for 6 and 12mo were significantly elevated （P〈0.05）, while the asthenopia gratings were significantly decreased （P〈0.05）. Nevertheless, in the control group,the amplitude of accommodation, accommodative lag, and accommodative sensitivity after 12mo were not significantly altered compared with baseline （P〉0.05）, and the asthenopia grating was not significantly decreased （P〉0.05）. In addition, after wearing glasses for 6 to 12mo, the asthenopia grating of patients in the test group decreased significantly compared with the control group （P〈0.05）. At 12mo, the constituent ratio of adverse reactions did not show significant difference between the two groups （P〉0.05）. CONCLUSION： A l-year follow-up reveal that compare with ordinary glasses, short-wavelength filtering lenses （blue/ violet-light filters） increase the low- and medium-frequency contrast sensitivity under bright conditions and improved accommodation. They effectively relieved asthenopia without severe adverse reactions, suggesting potential for clinical application. However, no significant advantages in terms of refractive power or axial length progression were found compared with ordinary aspheric lenses.

Back Illuminated N/P/P⁺Bifacial Silicon Solar Cell under Modulated Short-Wavelength: Determination of Base Optimum Thickness

A bifacial silicon solar cell under monochromatic illumination in frequency modulation by the rear side is being studied for the optimization of base thickness. The density of photogenerated carriers in the base is obtained by resolution of the continuity equation, with the help of boundary conditions at the junction surface (n+/p) and the rear face (p/p+) of the base. For a short wavelength corresponding to a high absorption coefficient, the AC photocurrent density is calculated and represented according to the excess minority carrier’s recombination velocity at the junction, for different modulation frequency values. The expression of the AC recombination velocity of excess minority carriers at the rear surface of the base of the solar cell is then deduced, depending on both, the absorption coefficient of the silicon material and the thickness of the base. Compared to the intrinsic AC recombination velocity, the optimal thickness is extracted and modeled in a mathematical relationship, as a decreasing function of the modulated frequency of back illumination. Thus under these operating conditions, a maximum short-circuit photocurrent is obtained and a low-cost bifacial solar cell can be achieved by reducing material (Si) to elaborate the base thickness.

Analysis on the fault characteristics of three-phase short-circuit for half-wavelength AC transmission lines

Half-wavelength AC transmission(HWACT) is an ultra-long distance AC transmission technology, whose electrical distance is close to half-wavelength at the system power frequency. It is very important for the construction and operation of HWACT to analyze its fault features and corresponding protection technology. In this paper, the steady-state voltage and current characteristics of the bus bar and fault point and the steady-state overvoltage distribution along the line will be analyzed when a three-phase symmetrical short-circuit fault occurs on an HWACT line. On this basis, the threephase fault characteristics for longer transmission lines are also studied.

A New Method for Measurements of the Poloidal Rotation Velocities and Wavelength Calibration of X-ray Imaging Crystal Spectrometer in Magnetic Fusion Devices

A new simple method is presented for the wavelength calibration and measurement of poloidal rotation velocities with X-ray imaging crystal spectrometer（XICS）in magnetic fusion devices.In this method,the toroidal rotation of plasma is applied for high precise alignment and wavelength calibration of the poloidal XICS.The measurement threshold of poloidal rotation velocity can be lowered to 1-3 km/s with this method.

Performance of dual-band short-or mid-wavelength infrared photodetectors based on InGaAsSb bulk materials and InAs/GaSb superlattices

In this paper,we demonstrate bias-selectable dual-band short-or mid-wavelength infrared photodetectors based on In0.24Ga0.76As0.21Sb0.79 bulk materials and InAs/GaSb type-II superlattices with cutoff wavelengths of 2.2μm and 3.6μm,respectively.At 200 K,the short-wave channel exhibits a peak quantum efficiency of 42%and a dark current density of5.93×10^-5）/cm^2at 500 mV,thereby providing a detectivity of 1.55×10^11cm·Hz^1/2/W.The mid-wave channel exhibits a peak quantum efficiency of 31%and a dark current density of 1.22×10^-3A/cm^2at-300 mV,thereby resulting in a detectivity of 2.71×10^10cm·Hz^1/2/W.Moreover,we discuss the band alignment and spectral cross-talk of the dual-band n-i-p-p-i-n structure.

短波紫外线辐照坛紫菜壳孢子制备色彩突变体的新途径

壳孢子萌发时期是坛紫菜(Pyropia haitanensis)减数分裂发生的时期,壳孢子萌发形成的最初4个细胞呈线性排列,形成减数分裂四分体,且发生遗传重组的四分体细胞可以决定叶状体的发育模式和性状分离。因此,诱变产生色彩突变的嵌合叶状体相比诱变叶状体产生的点状色块,将更易于获得突变细胞。本研究为获得坛紫菜人工色彩嵌合突变体,使用不同剂量(50、100、200、300、400、500和600J/m^(2))的短波紫外线(UV-C,λ=254nm)辐照坛紫菜壳孢子,培养数天后,在壳孢子苗中出现了色彩突变的嵌合叶状体。结果显示,低剂量(50 J/m^(2))的辐射促进壳孢子萌发,而辐照剂量高于100 J/m^(2)则会抑制壳孢子萌发和分裂。辐照剂量在50~400J/m^(2)范围内,色彩突变体出现的频率随辐照剂量的增加而增加,辐照剂量分别为300和400J/m^(2)时,突变率分别达到15.22%和17.18%。其中,出现色彩突变的嵌合叶状体以2色块嵌合体和3色块嵌合体居多,4色块嵌合体最少,但辐照剂量增加至400 J/m^(2)以上时,随着辐照剂量的增加,色彩突变体出现的频率反而下降,表明最适宜的诱变剂量为300或400 J/m^(2)。同时,短波紫外线辐照也使色彩突变嵌合体的长宽比下降,采用生物酶解法从色彩嵌合体中分离出了单色的体细胞萌发体。本研究为坛紫菜人工色彩突变体的制备和诱变育种提供了新途径。

基于3m波长地铁钢轨焊缝接头不平顺的轮轨响应分析

相对于1 m弦测值的焊缝接头动力学评估与管理,基于3 m波长范围的焊缝接头不平顺轮轨响应分析对其服役状态评估与管理具有重要意义。首先,基于车辆-轨道垂向耦合动力学理论建立车辆-轨道垂向耦合模型;然后,借助基于一弦N点弦测法研制的钢轨短波不平顺测量小车,对地铁线路焊缝接头不平顺进行精确测量,并根据传统弦测理论得到1 m弦测值;接着,将实测3 m波长焊缝接头不平顺和1 m弦测值作为车辆-轨道垂向耦合模型的不平顺激励输入,对比3 m波长焊缝接头不平顺和1 m弦测值激扰下的轮轨响应;最后,研究了车速和焊缝位置对轮轨动力响应的影响。结果表明:相比1 m弦测值激扰下的轮轨动力响应结果,3 m波长焊缝接头不平顺激扰下的轮轨力幅值变化不明显,轮重减载率幅值增大11.52%,钢轨加速度幅值增大54.05%,轮对振动加速度幅值增大37.67%;车速提高会导致轮轨力和轮重减载率幅值增大;焊缝中心与轨枕间的距离增加,轮轨力幅值先增加后减小,当焊缝中心距离轨枕0.1 m时,轮轨力幅值最大。

融合轨面短波不平顺的全波段高低不平顺谱表征及影响分析

轨道不平顺谱是表征轨道不平顺幅频特性的有效工具。目前,高速铁路轨道不平顺谱的研究主要聚焦在波长2 m及以上成分,甚少涉及轨面短波不平顺谱。基于大量无砟轨道高速铁路实测数据,研究轨面短波不平顺谱的表达函数及其与中长波轨道不平顺谱衔接的适应性。结果表明:两段幂函数能够很好地表征轨面短波不平顺谱。采用对数坐标系下的5阶多项式拟合全波段高低不平顺谱,实现中长波和短波成分在波长1~2 m范围内的平缓过渡。实测数据表明高速行车条件下,短波高低不平顺对轮轨垂向力及轴箱、构架和车体垂向加速度等指标均存在显著影响,全波段高低不平顺谱的建立对轮轨振动仿真分析、车辆和轨道结构设计以及轨道状态评估具有重要意义。

短波不平顺引起轮轨激振的中高频垂向力研究

为研究普通列车轨道不平顺对轮轨激振力的影响,采用LS-DYNA软件建立三维有限元轮轨耦合力学模型。该模型把车轮简化为质量点,轨道简化为梁,利用RAIL_TRAIN和RAIL_TRACK模块实现轮轨的耦合。利用该模型,分析不同车速、不同波长和幅值所表征的轨道不平顺引起的列车轮轨垂向力及其变化特点,并研究影响垂向力的敏感因素。结果表明:车速越低,不平顺波的幅值对轮轨垂向力的影响越大;相同的车速和不平顺波长,不平顺波的幅值越大,垂向力也越大,且垂向力和不平顺波的幅值近似呈线性关系;不同车速下,轨道不平顺的敏感波长不同,但其车速与敏感波长之比的频率均约为300 Hz,接近轨道的291.949 Hz(45阶模态频率)。

更快速度下周期性短波不平顺引起的轮轨高频振动特性及控制限值

随着列车运行速度的不断加快,轮轨高频振动引起的车辆、轨道部件伤损问题更加突出,尤以周期性的短波不平顺最为常见。为了掌握轮轨高频振动自下而上的传递衰减规律以及制定合理的钢轨打磨策略,有必要针对车辆系统在高频激励条件下的耦合振动特性开展深入的理论研究。本文通过对大量实测数据的拟合,得到了更宽频段范围内的轨道高低不平顺谱拟合公式,并通过反演得到了0.002~100 m波长范围内的高低不平顺样本;在此基础上建立了高速动车组-轨道刚柔耦合动力学模型,其中对轮对、钢轨均考虑了弹性体振动模态,仿真分析了周期性短波不平顺引起的轮轨高频振动特性。结果表明,车辆各部件的振动频率分布范围为30~1390 Hz,且自下至上呈逐层衰减趋势。通过提取周期性短波不平顺幅值变化对轮轨相互作用的影响规律,进一步提出了适应400 km/h高速铁路的典型波长周期性短波不平顺的量化控制限值要求。

Chemical Effect Analyses of 3d Elements by Study of X-Ray Fluorescence Spectra

Spectra of KX-rays emitted from pure 3 dtransition metals and their oxide and sulfate compounds were measured using a single crystal wavelength dispersive X-ray spectroscopy(WDXRF).The measurements were performed using a ZSX-100 esequential spectrometer equipped with an RhX-ray tube operated.An accurate analytical representation of each line was obtained by a fit to a Lorentz function.The spectra were analyzed in order to examine the KX-ray peak parameters such as asymmetry index,peak energy and relative intensity ratios.The energy shifts and relative intensities weredetermined tobetter understand the chemical effect.

New Insight into Electronic Neutrino Creation under X-Ray Absorption by Water Tetrahedron Intercalated with Hydronium Ion （H3O^＋）

In contrast to so-called Auger process resulting in electron ejection from oxygen atom of water molecule under X-ray absorption, the coupling of the opposite charges in liquid water leads to polaronic exciton formation. As a result, polaronic exciton stabilized by the structure of water tetrahedron can serve as the reaction center for deuterium creation under X-ray absorption. In this case, X-ray emission spectra of H：O and D20 give a clue for the deciphering of the events followed by X-ray photon absorption. It appears to be that spin-orbit interaction under proton sharing and the interaction between LO （longitudinal optical） phonon and bipolaron in the excited state are responsible for the energy levels determining neutrino energy. The energy gap between the levels with pATe andplle spin configurations of proton and electron is found to be 325.51 cm^-1 in the case of the spin-orbit interaction in polaronic exciton, while 1,556.054 cm^-1 under LO phonon interaction with the proton of the bipolaron producing the change of the nucleus spin direction to the opposite.

冬枣黑斑病的光学特性检测方法建立

本研究旨在探究冬枣果实黑斑病过程中光学特性的变化,并筛选出病害检测的特征波长。采用单积分球检测系统结合反向倍加(IAD)算法测定冬枣果实在黑斑病过程中短-中波近红外区域(900~1650 nm)内光学吸收和散射特性,通过光学特性与品质指标间的相关性分析获得特征波长,最后通过近红外光谱对特征波长的有效性进行了验证。研究结果表明,随着黑斑病的发展,冬枣果实的失重率和a^(*)呈现明显的上升趋势,L^(*)、可溶性固形物及叶绿素含量则随贮藏时间下降。冬枣果实的吸收系数(μa)和约化散射系数(μs')均表现出明显的下降趋势。μa和μs'分别在1400~1650和900~1360 nm与病害程度(病斑面积)和部分品质指标(失重率、L^(*)、a^(*)、可溶性固形物和叶绿素)呈现高度相关。与全波长和基于算法获得的特征波长模型相比,基于光学特性优选的10个特征变量建立的冬枣黑斑病判别模型效果最佳,建模集和预测集总体正确率分别达到92.53%和92.35%,证明了短-中波近红外光学信号识别不同病害程度冬枣果实的潜力及基于光学特性优选的特征波长的有效性。

绢云母短波红外光谱特征及其在矿产勘查中的应用

蚀变矿物短波红外(SWIR)光谱特征日趋广泛地应用于矿产勘查研究中。绢云母作为热液矿床中最为发育的蚀变矿物之一,通过SWIR光谱技术提取其谱学特征,进而建立与矿床基础地质信息之间的相关性具有重要意义。然而,前人对于绢云母短波红外光谱特征的研究主要集中于单个矿床,缺少不同矿床间的对比。基于此,文章梳理了混合矿物光谱曲线中对单一矿物相对含量的提取方式,系统总结了温度、流体化学成分、流体pH值、寄主岩石、矿物结构、矿物粒度及共(伴)生矿物等因素对绢云母谱学特征空间变化规律的影响,最后,从契尔马克替换效应角度出发,分析对比了5种不同成因类型矿床中近矿端绢云母波长变化。虽然将绢云母短波红外光谱特征有效地应用于矿产勘查仍存在诸多问题,但作者相信,应用绢云母短波红外光谱特征进行矿产勘查依然具有良好的前景。

短波红外偏振成像技术的研究进展

与传统成像系统相比,偏振成像系统通过探测目标物在不同状态下的明显偏振差异,提高对目标物的探测和识别能力,因而被广泛应用于复杂环境或有伪装物的目标探测。特别是短波红外谱范围的信息探测可以提供人眼所不能看见的分辨率和细节,是目前军事和民用领域的重点研究方向之一。这篇综述归纳总结了传统偏振成像系统的结构分类及其特点,探讨了新型微纳偏振成像系统的研究进展,并针对目前短波红外偏振成像技术存在的主要问题提供了可行性分析和建议。

龙门山造山带北段黄泥坪金矿床蚀变矿化特征与SWIR勘查应用研究

黄泥坪金矿床位于扬子地块西北缘,是龙门山造山带北段新发现的一个重要的中型金矿床,研究程度较低,蚀变矿化分布特征和矿床成因仍不清楚,需要新的勘查方法和思路开展下一步找矿工作。基于详细的矿床地质和短波红外光谱(SWIR)研究,发现黄泥坪金矿床的围岩蚀变主要有黄铁矿化、毒砂化、白云母化、硅化和碳酸盐化,白云母通常呈细小鳞片状分布于毒砂和黄铁矿的周围,金主要以不可见金的形式存在于毒砂和黄铁矿中。汉树沟、山关石、柳树坪和石罐子4个矿段应属同一成矿系统,其中汉树沟和山关石矿段的蚀变矿化期次可分为早期变质成矿期和晚期热液脉成矿期,变质成矿期包括石英多金属硫化物阶段和浸染状毒砂-黄铁矿阶段,热液脉成矿期包括石英-方解石粗脉阶段和毒砂-黄铁矿-方解石细脉阶段。变质成矿期发生了第一次金矿化,热液脉成矿期发生了第二次金矿化。SWIR勘查应用研究发现,矿体上盘千枚岩和下盘变质砂岩中发育较多Al–OH吸收峰位值较大的变质成因多硅白云母,而矿化部位则主要发育Al–OH吸收峰位值较小的热液白云母,Pos2200≤2202.5nm可作为热液白云母族矿物与变质成岩白云母族矿物或者二者混合相(指变质成岩白云母族矿物占主导,含有部分热液白云母族矿物)的大致界线。同时Pos2200≤2202.5 nm,且IC值为1.0~1.5可作为黄泥坪矿床新的勘查指标。本研究可以为认识龙门山北段浅变质沉积岩容矿的金矿床成矿规律和找矿勘查提供新的科学依据。

中心性浆液性脉络膜视网膜病变中扁平不规则色素上皮脱离的短波长和近红外眼底自发荧光图像特征

目的:观察中心性浆液性脉络膜视网膜病变(CSCR)眼中扁平不规则色素上皮脱离(FIPED)的短波长眼底自发荧光(SW-FAF)和近红外眼底自发荧光(NIR-FAF)图像特征。方法:选取2020年3月至2021年3月温州医科大学附属眼视光医院眼底内科确诊伴有FIPED的慢性或复发性CSCR 38例38眼。使用Spectralis HRA+OCT仪行SW-FAF、NIR-FAF等多模影像检查,分析FIPED的两种FAF图像特征。结果:38例慢性或复发性CSCR眼中有20眼存在血管化FIPED,18眼存在非血管化FIPED。血管化FIPED在SW-FAF上表现为点状弱自发荧光(AF,13例,占65%),混合状弱AF(4例,占20%),点状强弱混合AF(3例,占15%);非血管化FIPED在SW-FAF上表现为点状强弱混合AF(10例,占55.6%),点状弱AF(7例,占38.9%),混合状弱AF(1例,占5.6%)。血管化FIPED在NIR-FAF上表现为融合状伴点状弱AF(16例,占80%),斑片状强弱混合AF(4例,占20%);非血管化FIPED在NIR-FAF上表现为斑片状强弱混合AF(15例,占83.3%),斑片状弱AF(3例,占16.7%)。结论:慢性或复发性CSCR患者的血管化和非血管化FIPED具有特征性SW-FAF和NIR-FAF改变,能够指导治疗和随访。

短波近红外光谱法分析酒中乙醇含量

使用短波近红外光谱和多变量校正技术快速准确地测定酒中乙醇含量.研究了纯水、乙醇以及乙醇和水混合体系的光谱特征.用多元线性回归(MLR)和主成分回归(PCR)分析了二阶导数差谱数据.该法分析酒样具有方便、快速的优点.

短波红外InGaAs/InP光伏探测器系列的研制

采用气态源分子束外延方法及应用有源区同质结构及较薄的组分渐变InxGa1-xAs缓冲层,研制了波长扩展的InGaAs/InP光伏探测器系列,其室温下的截止波长分别约为1.9μm,2.2μm.和2.5μm.对此探测器系列在较宽温度范围内的性能进行了细致表征,结果表明在室温下其R0A乘积分别为765,10.3和12.7Ωcm2,比室温降低100K时其暗电流和R0A可改善约3个量级.瞬态特性测量表明此探测器系列适合高速工作,实测响应速度已达数十ps量级.

InGaAs近红外线列焦面阵的研制进展

研制出光谱响应为0.9～1.7μm的256×1、512×1元InGaAs线列焦平面组件,和光谱响应延展至2.4μm的256×1元InGaAs线列焦平面组件。焦平面组件包括光敏芯片、读出电路、热电制冷器以及管壳封装。光敏芯片在InP/InGaAs/InP(p-i-n)双异质结外延材料上采用台面结构实现,并与128×1或512×1元CTIA结构的读出电路耦合。焦平面器件置于双列直插金属管壳中,采用平行缝焊的方式进行封装。介绍了高均匀性长线列InGaAs焦平面组件的关键技术和主要性能结果,为更长线列焦平面组件的研制提供了坚实的基础。