常见红色宝石的色度学对比分析

根据色度学原理,利用USB2000+光纤光谱仪,量化常见红色宝石的色度学参数,通过比较分析可知,常见红色宝石在色度学方面呈现较明显的区别:具有近似色调角的红色宝石样品的明度L的值按照从大到小的顺序排列,分别为碧玺、尖晶石、石榴石、红宝石;具有近似色调角的红色宝石样品的色度a*和彩度C*的值按照从大到小的顺序排列,分别为碧玺、红宝石、尖晶石、石榴石,而色度b*的值按照从大到小的顺序排列,分别为石榴石、尖晶石、红宝石、碧玺.因此,利用光纤光谱仪、适当的照明方式及参数采集方法,应用色度学原理,可以对常见红色宝石在色度学方面进行初步对比分析.     

黄色翡翠的颜色测量及分析

根据色度学原理,利用美国Ocean Optics公司的USB2000＋光纤光谱仪对黄色翡翠进行测量与分析,量化黄色翡翠颜色的参数指标,包括其CIE 1931色度坐标、主波长、彩度、明度和CIE1931色品图等。依据主波长及色调角,可区分黄色翡翠颜色的主色调。实验结果表明,利用光纤光谱仪、适当的照明方式及光谱采集方法,应用色度学原理,可以客观、定量地描述黄色翡翠的颜色,可作为评价黄色翡翠颜色的适用技术。     

均匀色空间下红宝石颜色定量分级

采用国际照明委员会推荐的CIE1976均匀色空间,以CIELCH为表色系,采用X-rite i5测色仪量化红宝石的颜色指数.通过实验得到红宝石样品的颜色参数:色调角ho、饱和度C*、明度L.在标准光源下,将红宝石色调分为红色,粉红和紫红三个系列;饱和度分为灰、浅、中、浓、鲜艳五个级别;亮度分为暗、较暗、中等、较亮和亮五个级别.并综合颜色三要素,将红宝石颜色分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅶ、Ⅷ八个级别.     

仪器测色中几个易混淆的概念

结合高分子材料相关的测试标准以及测色仪在高分子材料测试中的应用,阐述并解析了仪器测色中几个易混淆的概念,包括颜色体系和仪器方面的以下6个概念:2°标准观察者和10°标准观察者、表色体系Lab和L*a*b*、色调角hab和色调差△H*ab、色彩色差计和分光测色计、几何结构以及镜面光泽包含和镜面光泽排除。掌握好这些概念的区别和联系,将有助于测量颜色时进行测试参数的选择,并加深对颜色测量技术的理解。     

基于图片的传统青瓷分类色度学研究

使用拍摄及出版条件尽可能相同的图片代替实物标本对青瓷进行了色度信息采集,利用可见光分光反射光谱主波长及在CIE1976 L*a*b*颜色空间中的色度值L*、a*、b*、C*、h°等进行对比研究,得到了区分青瓷釉色的客观测量依据。结果表明:基于图片的传统青瓷分类方法是可行的,从而解决了实物分散测量难度大且难以寻找平面测量的难题。测试数据表明12种青瓷的色调角算数平均值■有明显的差异,不同名称的传统青瓷有不同的h°值范围,因此色调角h°可作为区分青瓷釉色的主要特征参数。对比传统青瓷釉式,随着Fe_2_O__3含量的增加,12种青瓷釉色越深,其名称排列与其■由小到大排列基本吻合,这进一步验证了用色调角h°区分青瓷的可行性。而色度值L*、C*变化不大无法直接区分釉色;△a*、△b*值在区分同一坐标轴上的色差时较为清晰,但两者同时使用时,区分多种颜色没有明显规律;样品的反射光谱曲线主波长范围重叠率过高,较难区分青瓷类别。     

EDTA荧光探针测定微量铅

pH=4.00,c=0.3M的EDTA溶液在激发波长λex=267.5 nm,发射波长λem=380.8 nm时,有较强的荧光发射峰,随着Pb2＋的定量加入,其荧光猝灭与Pb2＋加入量成线形关系,相关系数r=0.9983,检测限为c=0.1 μg·L-1,测量范围为c=0～120 μg·L-1.从而可以利用EDTA荧光探针来测量未知样中Pb2＋的浓度.     

CIE1976 L*a*b*均匀色空间下照度对锰铝榴石颜色的评价

通过照度实验,基于CIE1976L*a*b*均匀色空间研究照度对锰铝榴石颜色评价的影响.照度增加,锰铝榴石黄色的明度L*显著增加,且自身明度较低的锰铝榴石黄色明度更易受照度变化的影响.△a*平均为17.30,△b*平均为36.83,明显大于△a*的均值,表明照度对锰铝榴石黄色调的影响更大;当照度较低时,彩度C*与照度呈正相关,当照度超过227.73 lx后,C*将不再增大或与照度呈负相关;色调角h0随照度增加而增大,平均色调角增量△h0=11.59,增幅较明度和彩度小.同时验证Stevens效应、Hunt效应、Helmholtz-Kohlrausch效应、Bezold-Brücke色相偏移理论在锰铝榴石颜色观察上的体现.此外,当明度差值DL* ＞15时,DL*与色差DE2000呈正相关且相关性最大,说明明度对色差具有最大贡献.得出结论,照度影响锰铝榴石的明度、彩度、色相,间接影响色差,其中对明度影响最直观,故在质量评价时应严格控制照度标准.     

三维荧光法测定人尿中1-羟基芘、β-萘酚和9-羟基菲

应用三维荧光法建立了直接测定人尿中的1-羟基芘、β-萘酚、9-羟基菲的新方法。通过β-环糊精增敏,三维荧光扫描选择测量波长。结果表明,在波长对λex/λem=275/385 nm时测定1-羟基芘,其线性范围和检出限分别为0.007～8.00μmol/L和2.30 nmol/L;在波长对为λex/λem=325/350 nm时测定β-萘酚,其线性范围和检出限分别为0.049～50.0μmol/L和12.5 nmol/L;在波长对为λex/λem=260/475 nm时测定9-羟基菲,其线性范围和检出限分别为0.023～40.0μmol/L和7.90 nmol/L。该方法已成功用于人尿中痕量1-羟基芘、β-萘酚、9-羟基菲的测定,与高效液相色谱法比较,结果满意,同时对β-环糊精增敏机制进行了初步探讨。     

三波长分光光度法测定苦丁茶中的黄酮

采用超声波萃取法提取苦丁茶中黄酮类化合物,以芦丁作为标准品,采用三波长分光光度法测定黄酮的含量。实验表明,回归方程为:△A=0.00314+18.03571c,相关系数r=0.9999,检测波长为λ1=365 nm,λ2=415 nm,λ3=450 nm,RSD 0.2%,实验的重现性好,方法简便可靠,效率高。     

燃烧法合成SrAl2O4:Eu2+,Dy3+发光材料及其性能研究

采用燃烧法在较低温度下快速合成了SrAlO:Eu2 ,Dy3 长余辉发光粉体,并利用XRD、荧光分光光度24计等测试手段,研究了合成粉体的物相结构以及工艺因素对材料发光性能的影响。结果表明,发光粉体的主晶相为SrAlO,属单斜晶系,晶胞参数为a=0.8442nm,b=0.8827nm,c=0.5162nm,β=97°;激发光谱主峰波长为24398nm、349nm、324nm,发射光谱主峰波长为516nm。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.