猫眼效应及猫眼宝石

具有猫眼效应的宝石是市场上常见的宝石品种,在检测过程中经常会有顾客拿出宝石来问：“这是不是猫眼？”,而大多宝石方面的书刊杂志对猫眼宝石的介绍也较为分散、零星,为使广大同仁和消费者对猫眼效应及猫眼宝石有全面的了解,有效地区别各种不同的猫眼宝石,提高对猫...     

猫眼宝石及其加工

作者在文中总结了多年加工猫眼宝石的经验，提出了加工猫眼宝石应注意的事项，文中还提出了评价猫眼宝石的建议。     

新发现的、罕见的猫眼宝石和星光宝石

描述了几个罕见的星光宝石和猫眼宝石. 产自巴西的淡蓝色托帕石显示出的猫眼效应是由扁平的管状孔洞引起的. 产自巴西的四射星光海蓝宝石有一个方向的星光是由平行c轴的管状孔洞引起, 另一组星光是由沿与c轴垂直方向排列的两相包裹体造成的. 一块产自巴西的碧玺-石英显示晕彩猫眼效应. 产自斯里兰卡的一块灰色正长月光石呈现出独特的猫眼效应和星光效应组合. 对造成这两种光学现象的缘由还不清楚. 来自俄罗斯的日光石具有清晰的猫眼效应, 是由钠长石-奥长石-正长石交互生长产生的条纹长石引起的. 四射星光的碧玺(双色锂电气石)有一个方向的星光是由管状孔洞引起, 另一方向的星光是由与c轴垂直的"发雏晶"引起的. 哈萨克斯坦菱锰矿具有的猫眼效应是由其类似于玛瑙的结构所致. 菱锰矿的四射星光效应是由两个方向的完全解理引起的.     

闪耀的星光水晶与水晶(石英)猫眼

<正>星光水晶和水晶(石英)猫眼,是具有特殊内含物、产生特殊光学效应、使人有特别感受的水晶。它们是水晶、硅质宝石中的珍品,在市场中倍受收藏者的青睐,也受到了珠宝爱好者和消费者的分外关注。     

玻璃质仿猫眼宝石的制作原理和工艺

天然矿石中具有高质量，明亮清晰闪光线条或星光状光学效果的宝石极为罕见。这类宝石的加工需作精确的定向切割再研磨成一定形状，在适合的光学条件下，才能呈现增强的星状或猫眼状光学效果。     

闪光猫眼宝石和美丽的孔雀石

在五光十色，千姿百态的大自然中，有些宝玉石矿物具有某种光学性质或矿物的内部潜伏有包裹体，乃可能会产生特异的光学效应。闪光猫眼宝石就是其中之一。     

用漫反射红外光谱鉴定具猫眼效应的宝石

漫反射红外光谱测试技术已在宝石学中得到了广泛应用。指纹频率对特定的分子是特征的,对分子结构的微小变化具有较大的灵敏性,可用于整个分子的表征。通过测试实践,总结了利用漫反射红外光谱测试技术快速鉴定具猫眼效应、外观相似宝石的鉴定特征,其分布在1 500~400 cm-1间的指纹峰差异可作为快捷、准确的鉴定特征。     

对宝石光学效果的研究及评价

宝石的光学效果主要包括颜色、亮度、火彩、闪烁等,除了宝石本身的性质,观察的位置、光线的明暗、背景的图案等也会对宝石的光学效果产生影响.在评价宝石颜色过程中,可使用比色石或者GemSet、GemDialogue以及Munsell色卡与宝石比色,对其质量做出半定量评价;可使用Color i5测色仪、X-riteI5分光光度仪、Color Eye7000A测色仪、USB2000光纤光谱仪测量宝石的明度、色相、饱和度、彩度、色纯度、色度坐标、主波长等颜色参数,通过比较各个参数之间的关系对其颜色质量进行评价,还可以利用色差公式展开进一步的讨论.为最大限度展现宝石的美,宝石学家发明了一系列不同类型的切割方式,传统的圆明亮型切割的切割比例可以达到较好的光学表现效果,但是根据不同的需求,可对宝石的比例做出轻微调整.对宝石光学效果的研究方法主要有两种,一种是通过光线追踪,另一种是通过摄影技术,对宝石的图像特征进行研究.测量宝石光学效果的仪器主要有Fire Scope、ASET instrument、Brilliance Scope、Diamond Integrator、钻石光学效果观察仪等.     

四川蛇纹石猫眼的矿物组成及显微形貌研究

采用傅里叶变换红外吸收光谱(FT IR)、X射线粉晶衍射(XRD)和扫描电子显微镜(SEM)分析方法对四川蛇纹石猫眼进行了研究。结果表明:四川蛇纹石猫眼主要组成矿物为纤蛇纹石,具有纤蛇纹石d202、006=0.2446nm(I/I0=29)和d202、006=0.2441nm(I/I0=27)X射线粉晶衍射的特征谱线。在960~1100cm-1间的红外谱图分裂成三个明显的谱带,570cm-1附近的红外谱带以肩状出现,3600~3690cm-1间的高频区出现两个谱带。蛇纹石纤维形态分为两类:一类是纤维韧性好,外表光滑干净,未见明显的溶蚀现象;另一类纤维平直,韧性差,外表粘有一些杂质,见有较明显的溶蚀现象。在垂直纤维方向上,蛇纹石纤维表现出内核为圆柱状、外壳为多角形的“内园外方”的结构模式。     

基于眼动追踪技术和数量化理论的包装设计要素分析

为设计出符合消费者感性需求的包装,采用眼动追踪技术和数量化Ⅰ类理论,研究通过眼动指标提取影响消费者情感的关键设计要素;通过语义差异法得到消费者的感性意象评价;应用数量化Ⅰ类理论研究感性意象和设计要素之间的关系并建立数学模型,辅助进行包装设计。以茶叶包装设计为案例分析,表明该方法是准确可应用的。     

强力霉素滴眼液对兔蒸发过强型干眼疗效的评价

目的研究强力霉素滴眼液对兔蒸发过强型干眼的治疗效果,并初步探讨其机理。方法新西兰大白兔16只,烧灼睑板腺开口制作干眼模型,术后第6周随机分为4组,分别不滴药及滴用1%甲基纤维素、0.1%强力霉素、1%甲基纤维素加0.1%强力霉素。用药前后定期检查角膜荧光素染色、虎红染色、结膜杯状细胞密度等。术后第1 1周取眼睑、结膜及角膜行病理检查。结果用药前各组兔角膜荧光素染色、虎红染色、结膜杯状细胞密度等指标无统计学差异(P<0.05)。用药后,甲基纤维素与强力霉素联合应用组荧光素染色及虎红染色比未用药组轻,结膜杯状细胞密度比未用药组高(P<0.05)。单用甲基纤维素或强力霉素组上述指标与未用药组比较无统计学差异(P>0.05)。病理检查未滴药组睑结膜及球结膜可见炎症细胞浸润,其它组未见明显的炎症细胞浸润。结论强力霉素滴眼液可以减轻干眼兔眼表的炎症反应,与甲基纤维素联合应用对兔蒸发过强型干眼有一定的治疗效果,提示强力霉素治疗干眼具有一定的应用前景。     

异形薄片零件的线切割加工工艺

针对异形薄片零件的线切割加工过程中的问题，从防止加工变形，加工路线制定等方面通过实例介绍了其加工工艺，提供了有关加工参数及操作注意事项。     

可视芯片技术及其在食品安全检测中的应用

相对于传统的生物芯片,可视芯片的结果观察无需特殊的设备仅用肉眼便可直接判定,该技术为快速准确地进行食品安全检测提供了一种崭新的技术平台。本文主要介绍了可视芯片的基本原理、种类及其研究进展,深入探讨了可视芯片技术在食品安全检测中的应用,包括对食源性致病微生物、转基因食品、真假植物油、食物中过敏原的检测,并对该技术在应用中存在的问题及未来的发展前景进行了阐述。      

饲喂鱼油对小鼠干眼症的治疗及缓解作用

研究饲喂鱼油对小鼠干眼症的治疗及缓解作用。采用苯扎氯氨诱导小鼠发生干眼症,并将其随机分为对照组(棕榈油替代鱼油)及鱼油饲喂组,饲喂14 d前后分别检测两组小鼠的泪液分泌量及泪膜破裂时间;14 d后处死小鼠,取眼周腺体,气相色谱法检测其DHA含量。结果表明:与饲喂前比较,鱼油饲喂组泪液分泌量增加、泪膜破裂时间明显延长(P0.05),对照组各指标变化不明显(P0.05);饲喂14 d后组间比较,鱼油饲喂组泪液分泌量增加、泪膜破裂时间明显延长(P0.05);饲喂14 d后,鱼油饲喂组眼周腺体中DHA含量极显著高于对照组(P0.01);高DHA膳食可减轻苯扎氯铵诱导的干眼症小鼠的干眼症状,可能与眼部腺体中DHA的供应有关。     

The effect of the duration of diabetes on dry eye and corneal nerves

PurposeTo investigate the relationship between the duration of type 2 diabetes mellitus (DM) and the ocular surface, and to address the question of why some people with lengthy DM duration are asymptomatic, whereas some people with shorter DM duration have pain or discomfort in their eyes.MethodsEighty-seven eyes of 87 subjects with different durations of DM and 49 eyes of 49 subjects without DM underwent Schirmer I test, tear film break-up time, sodium fluorescein staining and tear meniscus height (TMH) measurement, and completed the Standardized Patient Evaluation of Eye Dryness (SPEED) questionnaire. Corneal structure and function were assessed with in vivo confocal corneal microscopy and with a corneal sensitivity esthesiometer. Both corneal nerve fiber length and inferior whorl length (IWL) were assessed as indices for neural structure. Age and gender were matched between groups. HbA1c levels >7.8% and proliferative diabetic retinopathy were exclusion criteria.ResultsIn the DM group, compared with the non-DM group, the SPEED score was significantly higher (p = 0.013), and corneal sensitivity and IWL were lower (p < 0.001). Schirmer I test, corneal sensitivity and IWL differed significantly between the group with DM duration >10 years and the non-DM (control) group (p = 0.021, p < 0.001, p < 0.001, respectively). Schirmer I test and IWL were significantly lower in the group with DM >10 years than in the group with DM ≤10 years (p = 0.023, p < 0.001, respectively). Corneal sensitivity was positively correlated with IWL regardless of diabetes status.ConclusionsThe lower SPEED score and asymptomatic feeling in people with a longer DM duration may be explained by the decreased IWL and reduced sensitivity.     

Attitudes of eye health practitioners towards diagnostic tests and therapies for dry eye disease in Australasia

IntroductionThe diagnosis of dry eye is challenging for eye health practitioners (EHP) and recently, a variety of new diagnostic tests have emerged. This study assesses the attitudes of EHP to dry eye and testing and compares these with attitudes in 2003.MethodsAn electronic questionnaire was disseminated to EHP in Australasia between December 2020 to March 2021. Participants rated the likelihood that presenting symptoms/signs were associated with dry eye, the utility of diagnostic tests, the value of test characteristics, and their satisfaction with dry eye diagnostics. Qualitative responses were categorised into positive, negative, or neutral themes.Results144 responses were received, with 117 (81.3%) from Australia and 27 (18.7%) from New Zealand. Posterior blepharitis was significantly more likely to be associated with dry eye than other factors (p < 0.01). Clinical history, fluorescein staining and FBUT were judged significantly more useful in diagnosing dry eye compared to other tests (p < 0.01). Test validity was judged significantly more important in choosing a test than other qualities. Qualitative attitudes towards dry eye presentations and diagnostic tests were positive in 42.2% and 24.3%, negative in 32.4% and 41.9%, and neutral in 25.5% and 33.8% respectively.ConclusionsThe opinions of EHP regarding dry eye tests were variable, but most favour history and corneal staining for diagnosis. Patterns of responses were similar to that reported by Turner et al 16-years ago, however, there is a higher satisfaction with available tests and therapeutic options. There is a need to develop a consensus amongst real-world clinicians regarding an optimum diagnostic pathway for dry eye, particularly in relation to newer diagnostic tests.     

The effects of breaks on digital eye strain,dry eye and binocular vision: Testing the 20-20-20 rule

PurposeTo evaluate the benefits on the eyes of taking breaks based on the 20-20-20 rule.MethodsBespoke computer software using the laptop webcam to assess user breaks, eye gaze and blinking, and emitting personalized reminders of breaks based on the 20-20-20 rule, was downloaded onto the laptops of 29 symptomatic computer users. Digital eye strain (DES), binocular vision and dry eye were assessed before and after two weeks of using the reminders and one week after the discontinuation of the strategy. Binocular measurements included visual acuity, accommodative posture, stereopsis, fixation disparity, ocular alignment, accommodative facility, positive/negative vergences and near point of convergence. Symptoms were evaluated using the computer vision syndrome questionnaire, ocular surface disease index (OSDI), and symptom assessment in dry eye questionnaire (SANDE) versions one and two. Dry eye signs were assessed by measuring tear meniscus height, conjunctival redness, blink rate and incomplete blinking, lipid layer thickness, non-invasive keratograph break-up time, corneal and conjunctival staining and lid wiper epitheliopathy.ResultsA decrease in the duration of computer work and the duration of breaks, along with an increase in the number of breaks taken per day was observed as a result of the 20-20-20 rule reminders (p ≤ 0.015). No changes on any binocular parameter were observed after the management period (p ≥ 0.051), except for an increase in accommodative facility (p = 0.010). Dry eye symptoms and DES decreased with the rule reminders (p ≤ 0.045), although this improvement was not maintained one week after discontinuation (p > 0.05). No changes on any ocular surface and tear film parameter were observed with the rule reminders (p ≥ 0.089).ConclusionsThe 20-20-20 rule is an effective strategy for reducing DES and dry eye symptoms, although 2 weeks was not enough to considerably improve binocular vision or dry eye signs.