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排序方式: 共有948条查询结果,搜索用时 15 毫秒
1.
利用室温下压电调制反射光(PzR)谱技术系统测量了N掺杂浓度为0.0%—3%的分子束外延生长GaNxAs1-x薄膜,并对图谱中所观察的光学跃迁进行了指认.在GaN0.005As0.995和GaN0.01As0.99薄膜的PzR谱中观察到此前只在椭圆偏振谱中才看到的N掺杂相关能态E11N.当N掺杂浓度达到 关键词: 压电调制反射光谱(PzR) xAs1-x薄膜')" href="#">GaNxAs1-x薄膜 分子束外延(MBE)  相似文献   
2.
Objective assessment of gastrointestinal mucosal color is extremely important in the endoscopic diagnosis of digestive tract disease. In this paper, we propose a method to clarify the spectral characteristics of gastric and colon cancer. A large number of spectral reflectance data of mucous membrane are measured by the endoscopic spectroscopy system (ESS) in the National Cancer Center Hospital East, Kashiwa, Japan and the Department of Internal Medicine, Self-Defense Force Center Hospital, Tokyo, Japan. We assume that early cancer appears primarily in the spectral data of short wavelength, because it is usually present in a superficial cell where short wavelength light is scattered more strongly than long wavelength light. To identify the features in the short wavelength components, the spectral reflectance was divided by the reflectance of a long wavelength. We investigated the possibility of distinguishing early cancer from normal spectral data through statistical analysis, employing the projection axis as the mean difference between them. Early cancer and normal spectral data were projected on the projection axis, and the Student’s T-test was applied to evaluate the mean of the distribution between these data.  相似文献   
3.
A new scheme of optical film sensor is presented. The sensor is based on p-polarized reflectance, consisting of a sensing coated substrate, is easily optimized for maximum sensitivity in different applications. The resolutions of refractive index nf, extinction coefficient kf and thickness hf of the sensitive films are predicted to be 10−7, 10−5 and 10−3 nm, respectively. Experimentally, we selected the sol–gel derived SnO2 films as gas-sensitive films and conducted preliminary gas-sensing test. The results indicate that novel optical film sensor scheme has higher sensitivity, and the detection sensitivity is available to 10−1 ppm on the condition of optimum optical parameters and incident angle.  相似文献   
4.
The well-known equations for the optical functions of reflectance, transmittance and phase changes on reflection and transmission for a solid material have been rearranged into the form of simple geometric figures in the u, v (n, k) plane. The curves for Fp show a singularity on the n-axis.  相似文献   
5.
ATR-FTIR光谱技术在聚合物膜研究中的应用   总被引:7,自引:0,他引:7  
江艳  沈怡  武培怡 《化学进展》2007,19(1):173-185
红外光谱是聚合物研究中常用的一种表征手段,而衰减全反射红外光谱(ATR-FTIR)更是由于在研究聚合物薄膜方面具有显著的优势而被广泛使用。逐层组装(layer-by-layer Assembly)技术是一种常用的组装聚合物超薄膜的方法,ATR-FTIR光谱技术的引入可以在获取膜组装过程中相应信息的同时有效地避免表征过程中对样品的损害。另一方面,ATR-FTIR方法与二维相关光谱技术(two-dimensional correlation spectroscopy, 2D correlation spectroscopy)相结合也是研究小分子(主要是水分子)在聚合物薄膜中的渗透行为的有效手段。本文对ATR-FTIR的基本原理和显著特点作了介绍,并以实例阐述该方法在逐层组装技术和水分子在薄膜内渗透行为研究两方面的应用。  相似文献   
6.
张平  王乐夫 《分析化学》2002,30(12):1469-1472
利用原位分析方法对催化剂表面吸附态进行动态表征,对了解催化反应机理具有重要的意义。漫反射红外光谱是一种理想的原位方法,应用该方法在298-773K范围原位考察了以丙烯为还原剂,NO在Ag-ZSM-5催化剂上的吸附态及选择性催化还原过程。认为NO的选择性催化还原符合直接作用机理,还原的关键是形成有机-氮氧化物(R-NO2或R-ONO)中间体。O2的作用是使C3H6充分活化,并是有效产生有机-氮氧化物不可缺少的条件。  相似文献   
7.
近红外漫反射光谱法对固态样品的无损分析   总被引:1,自引:0,他引:1  
任玉林  邴春亭 《分析化学》1996,24(11):1291-1294
本文应用目标因子分析研究了固态样品的近红外漫反射光谱,用目标因子分析成功地确定了固态样品的物种数、物种种类和各物种的含量。  相似文献   
8.
将芯片式流通池顺序注射可更新表面反射光谱法用于酶反应检测。HRP催化H2O2氧化BPR底物的反应用于对H2O2的检测。此反应体系与葡萄糖氧化酶联用,用于对血清中葡萄糖的检测。  相似文献   
9.
8-Hydroxy-5-azoquinoline phenyl methacrylate-formaldehyde (8H5AQPMA-F) macromonomer was prepared from methacryloyl chloride with condensation products of 8-hydroxy-5-azoquinoline phenol-formaldehyde, and polymerized in DMF at 70 °C using benzoyl peroxide as free radical initiator. Poly(8H5AQPMA-F) was characterized by infrared and nuclear magnetic resonance spectroscopic techniques. Polychelates were obtained when the DMF solution of the resin containing few drops of ammonia was treated with the aqueous solution of Cu(II)/Ni(II). Elemental analysis of the polychelates indicates that the metal to ligand ratio was about 1:2. The IR spectra of polychelates suggest that the metals were coordinated through the oxygen of the phenolic-OH group and nitrogen of the quinoline ligand. The DRS and magnetic moment data indicate a square planar for Cu(II) complex whereas octahedral for Ni(II) complex. The TGA data revealed the thermal stability of the resin and the polychelates. X-ray diffraction study revealed the incorporation of the metal ions significantly enhanced the degree of crystallinity. The sorption properties of the chelate-forming resin towards various divalent metal ions [Cu(II) and Ni(II)] were studied as a function of pH and electrolyte.  相似文献   
10.
To screen for organic pigments, like fringelites or porphyrins, in sediments and fossil specimen, a simple diffuse reflectance UV-vis spectroscopic determination was developed. In contrast to common inorganic pigments, like Fe2O3, these pigments exhibit well-structured characteristic absorption peaks which allow their recognition. This method was then used to identify fringelite H in a non-crinoidSolenopora species from the Jurassic. Reflectance FTIR spectroscopy proved not to be useful for this purpose.  相似文献   
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