激光干涉法测量硅高温环境下的线膨胀系数的实验研究

利用中国计量科学研究院自行设计的基于激光干涉法的材料线膨胀系数测量装置进行了材料线膨胀系数测量试验。该装置采用单频激光干涉，对称光路设计，其干涉仪分辨率小于1nm。实验过程中改进并完善了该装置，重新设计了加热炉，改进了实验方法，使该装置在800K以上的高温环境下能进行材料线膨胀系数的测量。在800K到1200K温度范围内，对单晶硅试样采用分段加热进行测量,并对样品变化过程及测量结果作了分析，得到了单晶硅线膨胀系数的曲线，实现了在1200K环境下采用激光干涉法材料线膨胀系数的纳米级测量。     

具有颜色恒常性的光谱反射率重建

给定物体三刺激值,重建物体反射率在跨媒体颜色复制领域有着重要应用.常见的重建反射率算法包括基向量法、维纳估计法、加权伪逆方法等,这些方法大多都是为了建立由低维度三刺激值或者RGB向高维度光谱反射率的映射关系,以重建的反射率与原始反射率的接近程度为评价指标,并且需要光谱反射率数据进行训练.但是很多工业领域在产品设计时都需...     

高温黑体性能评定和温度测量

中国计量科学研究院引进了高温黑体BB3500M作为新的光谱辐射照度基准光源。黑体BB3500M包括辐射腔体和温度反馈系统。辐射腔体由一系列高温热解石墨环组成,可以加热至3 500 K。在光谱辐照度测量中,高温黑体的性能参数和温度测量至关重要。对于黑体的性能参数,着重考察了黑体温度的稳定性和腔底温度的均匀性。在将高温黑体的光谱辐射照度传递给工作标准灯时,黑体的温度可能发生改变。实验观测了一小时内黑体的温度漂移情况。当高温黑体加热至3 016 K时,采用温度反馈系统的BB3500M稳定在0.3 K。实验光路中设置了限制光栏,用于屏蔽来自黑体腔壁的辐射。黑体腔底辐射环的温度均匀性优于0.2 K。在温度测量中,2 473 K以下的温度可以直接溯源到中国计量科学研究院热工处,对于更高温度的测量需要进行温度延伸。文中从普朗克公式出发,通过多波长亮度比较法进行了温度延伸。实验先在低温区进行延伸证实了方法的可能性,然后进行了高温区的温度延伸。     

The Iterative-DRESOR method to solve radiative transfer in a plane-parallel, anisotropic scattering medium with specular-diffuse boundaries

Using the intensity with high directional resolution obtained by the Basic-DRESOR method as an initial guess, which is substituted into the integrated radiative transfer equation (IRTE), an iterative algorithm is proposed, called the Iterative-DRESOR method. This method can reduce the error levels of the intensity from several percent using the Basic-DRESOR method to a level of less than 1.0×10⁻⁶ with acceptable computation costs. The method is also validated against the exact heat flux in literature in some cases. It further clarifies some uncertain results for the reflectance in a pure, linearly anisotropic scattering medium with specular-diffuse boundaries. The directional distributions of intensity are obviously influenced by the reflecting modes of the boundary, especially in the zone near the boundary. The reflecting mode of an emitting boundary has little effect on the transmittance or reflectance. The reflecting mode of a non-emitting boundary also has little effect on the transmittance, but it obviously influences the reflectance. The difference between the reflectance for specular and diffuse boundaries increases at first, and then decreases, as the optical thickness of the medium increases. The difference will decrease as the scattering albedo of the medium increases, and it is negligible when the medium is pure scattering. The effect of the scattering phase function of the medium on the difference can also not be ignored. The Iterative-DRESOR method is expected to strengthen the capability of the Monte Carlo method to produce accurate results and to validate the results of other methods to solve RTE.     

温莪术环状含氧倍半萜类化学成分的研究

采用超临界流体CO2萃取（SFE-CO2）技术提取温莪术Curcuma wenyujin Y．H．Chen et C．Ling挥发油,用多种色潜和波谱方法对油中主成分进行分离和结构鉴定。结果分离得到5个环状含氧倍半萜类化合物,分别鉴定为：蓬莪术环二烯（Ⅰ）（furanodiene）、莪术二酮（Ⅱ）（curdione）、莪术双环烯酮（Ⅲ）（curcumenone）、（4S,5S）大牻牛儿酮4,5环氧化物（Ⅳ）（（4S,5S）-gemlacrone-4,5-epoxide）、莪术烯（Ⅴ）（curzerene）;其中蓬莪术环二烯含量约占莪术油30％,莪术双环烯酮系首次从温莪术中得到。并对上述5个化合物进行了THP-1细胞分泌TNF旺炎症因子抑制作用的体外活性实验,实验结果表明：蓬莪术环二烯和莪术烯对THP-1细胞分泌TNFct炎症因子有明显的抑制作用。     

退火处理对ZnO薄膜晶体结构和导电性能的影响

利用直流反应磁控溅射法在硅衬底上沉积C轴择优取向的ZnO晶体薄膜,将该样品进行退火处理,并测量了样品的导电性能,结果显示退火处理可以引起薄膜的重结晶,从而改善薄膜的结晶状况,改变薄膜中的化学配比.退火后样品的薄膜电阻相对较小,增加了薄膜中施主的浓度,增强了薄膜的导电性.     

新型C~n[M(dmit)~2]类导电配位化合物的研究

首次将不饱和杂原子环状阳离子(N-甲基吡啶阳离子、N-甲基喹啉阳离子和N-甲基苯并噻唑阳离子)及三甲基苯基铵阳离子引入[M(dmit)~2]^n^-体系制备得到了6个新型的导电配位化合物C~n[M(dmit)~2](M=Ni,Pd,Pt,n=2,1)。对这些新化合物进行了组成和结构的测定,研究了它们的IR,UV,ESR和XPS,测定了变温磁化率和室温导电率。结果表明,外部阳离子的大小和形状会影响阴离子部分[M(dmit)~2]^n^-的荷电量以及电荷分布,从而导致配合物性能的改变,说明外部阳离子可以通过另外一种方式来影响配合物的电性能。     

叶绿素荧光成像技术的葡萄霜霉病早期检测

葡萄霜霉病对葡萄生产构成严重威胁,尽早防治是治理霜霉病的关键.为了对该病进行早期检测,以PCR检测获取的霜霉病相对生物量作为霜霉病侵染的依据,从暗适应—光适应—暗弛豫3个光合生理状态连续变化过程中,采集80个人工接种霜霉菌叶片和80个健康对照叶片连续6 d的叶绿素荧光图像.对比健康和接种叶片叶绿素荧光动力学曲线、参数图...     

PHOTO- AND ELECTRO-LUMINESCENCE FROM HYDROGENATED AMORPHOUS SILICON CARBIDE FILMS PREPARED BY USING ORGANIC CARBON SOURCE

Hydrogenated amorphous silicon carbide (a-SiC:H) films were grown by using an organic source, xylene (C₈H₁₀), instead of methane (CH₄) in a conventional plasma enhanced chemical vapor deposition system. The optical band gap of these samples was increased gradually by changing the gas ratio of C₈H₁₀ to SiH₄. The film with high optical band gap was soft and polymer-like and intense photoluminescence were obtained. Room temperature electro-luminescence was also achieved with peak energy at 2.05 eV (600 nm) for the a-SiC:H film with optical band gap of 3.2 eV.     

激光偏振方向和强度变化对分光光强的影响

在双光路补偿强度调制型光电检测系统中,采用分光镜后透射光强和反射光强会随着激光光源偏振方向和强度的变化而变化,这严重破坏了强度补偿机理。详细推导了激光光源偏振方向变化时分光比的变化公式,举例说明了分光比随偏振角的变化情况,并给出了反射光强和透射光强的变化规律。重点讨论了当激光光源偏振方向和强度同时变化时分光比的变化规律。提出了采用偏振光源或偏振片的两种解决办法。