化妆品用茶油光谱特性分析

用紫外分光光度法分析化妆品用茶油的光谱特性。通过与常用的油类基质橄榄油及乙二醇进行比较,发现茶油对紫外光有很好的吸收,特别在250～357nm这一区间,是一种理想的化妆品用油类基质。通过比较研究发现超临界CO2萃取法制取的茶油的紫外吸收情况明显好于浸出法和水代法所得茶油。另外还发现相同水代法提取的湖南双峰普通油茶的茶油比浙江红花油茶吸收紫外的效果要好。这说明不同萃取方法及不同品种间所得茶油的光谱特性也不尽相同。     

纳米TiO2薄膜的制备及其紫外光吸收性能的研究

采用sol-gel法制备TiO2薄膜。用XRD、AFM对其结构及表面形态进行了表征。用UV、SPS测试其光谱吸收、表面光伏特性。结果表明,在高软化温度ITO玻璃上得到比较好的锐钛矿型TiO2薄膜,且具有很强的紫外光吸收特性。随着烧结温度的升高,锐钛矿晶型更加趋于完整,使得紫外吸收曲线的带边蓝移。在紫外光照射下,所制得的薄膜有明显的光伏效应。较之粉体材料,吸收峰更趋向紫外区。为进一步研制新型紫外光传感器提供实验依据。     

氙灯紫外区光谱特征的研究

在不同的参数和工作条件下,测量了氙灯(150W)的紫外绝对光谱辐照度(200～380nm)。对其在此波段呈现的光谱特性进行了分析。得出计算氙灯光谱辐照度的经验公式。分析结果表明,氙灯具有成为高强度紫外光谱辐照度标准传递光源的良好光谱特性。     

XPS和AES研究PMTA-Ag~+配合物膜

本文研究了各种防银变色剂的防变色效果。结果表明,巯基苯基四氮唑(PMTA)在紫外光和H_2S中具有优良的防变色效果。紫外吸收光谱的测定表明,PMTA在190～240nm处有一很宽的紫外吸收带,它可以完全复盖AgNO_3在190-220nm处的吸收带。PMTA的优良紫外吸收性能可以有效地阻止紫外光对银变色的加速作用。     

气体放电光源在紫外光阴极研究中的应用

本文根据紫外光阴极的应用波段和研究方法,指出,在合理设计阴极结构的基础上,研究工作的重要环节在于如何选用有效的检测光源。文中详细介绍了各种检测光源的光谱特性,并就氢真空紫外辐射源的应用,讨论了研制真空紫外光阴极的有关测试技术。     

纳米TiO2薄膜的低温制备与光谱特性研究

以钛酸丁酯为原料,采用改进溶胶-凝胶法,通过浸渍-提拉工艺在低温条件下制备了锐钛矿纳米TiO2薄膜。利用X射线衍射、紫外-可见光吸收光谱、傅里叶变换红外光谱对所制备的TiO2薄膜的晶型结构和光谱特性进行了分析,并利用紫外光照降解亚甲基蓝溶液来评价所制备薄膜的光催化活性。结果表明:经过陈化和水浴处理后,钛酸丁酯完全水解,所得TiO2薄膜为锐钛矿结构,对紫外光表现出较强的吸收特性。低温水浴处理有利于提高薄膜的光催化活性。     

紫外辐照对聚丙烯／纳米TiO2／POE复合材料薄膜紫外光透过性能的影响

采用UV-Vis漫反射光谱法研究比较了表面改性前后金红石型纳米TiO2的紫外．可见光学特性，通过熔融共混法制备了金红石型纳米TiO2和受阻胺光稳定剂改性PP／POE材料，对其进行了15d的紫外辐照加速老化，对比测试了纯PP和改性PP复合材料薄膜辐照前后的紫外光透过性能，结果表明：纯PP和PP／POE薄膜经过1d的紫外光辐照后，其紫外光总透过率，分别增大了11．53％和22．09％，而添加了0．5％（质量分数）纳米TiO2的复合材料薄膜虽经过15d紫外光辐照，但是透过率，基本未发生变化。     

波动信号测量方法研究

一、概述中国计量科学研究院光学所研究建立了深紫外光谱透射比测量装置,其光谱范围覆盖(115~300)nm,可以与常用的紫外可见近红外光谱透射比测量装置的紫外光谱区域相衔接,并向真空紫外区域拓展。其测量结果的相对扩展不确定度为Urel=3.0%。相对于传统的可     

Al_2O_3感光薄膜的制备及其微细图形化研究

提出一种利用感光溶胶-凝胶法结合紫外光刻技术制备Al2O3微细图形的方法。以Al(O-SecBu)3为前驱物,β-二酮类配体H(C10H12O2)为化学修饰剂,合成了稳定的、具有良好感光性的含Al金属螯合物,进而制备出相应的感光薄膜。研究了薄膜的紫外和红外光谱特性及其在紫外光辐照条件下的变化过程,结果表明金属螯合物薄膜在251,321和368nm处各存在较强的紫外吸收峰。随着紫外光照时间的增加,吸收峰下降,Al2O3/H薄膜表现出明显的感光特性。结合紫外光刻技术,可制备出不同形状尺寸的Al2O3微细图形,其最小线宽可达437nm。     

瓷砖表面防晒类护肤品指印的紫外光谱特性研究

目的:运用紫外光谱成像技术检验瓷砖表面护肤品指印,利用指印的紫外光谱影像集及紫外光谱曲线图分析其对紫外线反射及吸收性质,为潜在指纹提取提供技术支持.方法:运用紫外光谱成像技术显现防晒类护肤品指印,分析实验结果,总结实验数据,获得最佳提取波段.结果:紫外光谱成像技术是瓷砖表面防晒类护肤品指印提取和检验的有效手段.结论:紫外光谱成像技术能够显现防晒类护肤品指印,但其显现效果受指印载体的材质、颜色、表面性质及护肤品的成分的影响.     

苯乙烯-丙烯腈共聚物对聚氯乙烯加工性能及抗紫外老化行为的影响

通过苯乙烯-丙烯腈共聚物(SAN)共混改性聚氯乙烯(PVC),制备了PVC/SAN共混材料。利用转矩流变、色差分析、表面形貌分析、元素分析等方法研究了PVC/SAN共混材料的加工性能和抗紫外老化性能。结果表明,SAN的加入可促进PVC的塑化,改善其加工性能;同时SAN具有较强的紫外光吸收能力,能抑制PVC脱氯化氢,显著降低紫外老化时PVC颜色变暗、变红和变黄的速率;此外SAN的引入使PVC/SAN共混材料表面平整、致密,可以有效阻止紫外光和氧气深入到材料内部造成严重的破坏,从而显著提高PVC的抗紫外老化性能。     

Levels of depleted uranium in Kosovo soils

The United Nations Environment Programme (UNEP) has performed a field survey at 11 sites located in Kosovo, where depleted uranium (DU) ammunitions were used by the North Atlantic Treaty Organization (NATO) during the last Balkans conflict (1999). Soil sampling was performed to assess the spread of DU ground contamination around and within the NATO target sites and the migration of DU along the soil profile. The 234U/238U and 235U/238U activity concentration ratios have been used as an indicator of natural against anthropogenic sources of uranium. The results show that levels of 238U activity concentrations in soils above 100 Bq x kg(-1) can be considered a 'tracer' of the presence of DU in soils. The results also indicate that detectable ground surface contamination by DU is limited to areas within a few metres from localised points of concentrated contamination caused by penetrator impacts. Vertical distribution of DU along the soil profile is measurable up to a depth of 10-20 cm. This latter aspect is of particular relevance for the potential risk of future contamination of groundwater.     

Clinical diagnostic indicators of renal and bone damage in rats intramuscularly injected with depleted uranium

The toxic effects and changes in biochemical markers related to kidney and bone in depleted uranium (DU)-injected rats were examined in order to clarify the relation between clinical biochemical markers and the degree of damage in these organs. Male Wistar rats received a single injection in the femoral muscles of 0.2, 1.0 or 2.0 mg kg(-1) of DU which was dissolved in nitric acid solution adjusted to pH 3.2, for comparison with the group injected with nitric acid solution, and the control group. Urine and faeces were collected periodically over a 24 h period. Thereafter, the rats were killed at 28 d after DU injection. The body weights of the DU-injected groups decreased dose-dependently for the first 3-7 d, and then began to increase. The DU concentrations in the urine and faeces decreased rapidly within 3-7 d after DU injection. Urinary N-acetyl-beta-D-glucosaminidase (NAG)/creatinine peaked at the third day after DU injection, with a high correlation to the injected DU doses. There were high correlations among the injected DU doses, DU concentrations in the kidney and urinary NAG/creatinine values that were obtained at 28 d, respectively. The blood urea nitrogen (BUN) and creatinine in the serum also showed a high correlation with the DU-injected doses. The results indicated that urinary NAG/creatinine, BUN and creatinine in serum were useful indicators to diagnose the renal damage by DU, as well as to estimate the DU intake and concentration in the kidney when the intake is >2 mg kg(-1) DU. The total bone mineral density of the proximal metaphysis of the tibia decreased in the 2 mg kg(-1) DU group. In addition, alterations of the trabecular bone structure by inhibiting bone formation and promoting bone resorption were observed by bone histomorphometery. The bone biochemical markers osteocalcin, tartrate-resistance acid phosphatase, pyridinoline and rat-parathyroid hormone increased in all the DU injected groups, indicating that these markers were useful as sensitive indicators for diagnosing bone damage, even if the DU dose injected is low.     

Removal of depleted uranium from contaminated soils

Contamination of soil and water with depleted uranium (DU) has increased public health concerns due to the chemical toxicity of DU at elevated dosages. For this reason, there is great interest in developing methods for DU removal from contaminated sources. Two DU laden soils, taken from U.S. Army sites, were characterized for particle size distribution, total uranium concentration and removable uranium. Soil A was found to be a well graded sand containing a total of 3210 mg/kg DU (3.99 x 10(4) Bq/kg, where a Becquerel (Bq) is a unit of radiation). About 83% of the DU in the fines fraction (particle diameter <0.075 mm, total DU 7732 mg/kg (9.61 x 10(4) Bq/kg)) was associated with the carbonate, iron and manganese oxide and organic matter fractions of the material. Soil B was classified as a sandy silt with total DU of 1560 mg/kg (1.94 x 10(4) Bq/kg). The DU content in the fines fraction was 5171 mg/kg (6.43 x 10(4) Bq/kg). Sequential extraction of the Soil B fines fraction indicated that 64% of the DU was present either as soluble U(VI) minerals or as insoluble U(IV). Citric acid, sodium bicarbonate and hydrogen peroxide were used in batch experiments to extract DU from the fines fraction of both soils. Citric acid and sodium bicarbonate were relatively successful for Soil A (50-60% DU removal), but not for Soil B (20-35% DU removal). Hydrogen peroxide was found to significantly increase DU extraction from both soils, attaining removals up to 60-80%.     

废陶瓷回用抗原子氧和紫外线磁性复合材料的研究

本文研究了废陶瓷回用抗原子氧和紫外线磁性复合材料。研究结果表明,原子氧和紫外辐射都会影响有机聚合物的性能。但是废旧陶瓷和铁氧体在化学上非常稳定,既不与原子氧发生反应,也能阻挡其与有机织物的接触,所以保证了基体的强度。     

纳米TiO2浆料改性氯醚树脂防蚀涂层的初步研究

氯醚树脂生产环保、防蚀性能好,但其耐候性不佳,有待改进.纳米TiO2抗紫外性能优异,但有关其改性防蚀涂料及性能的研究鲜见报道.为此,采用金红石型纳米TiO2对氯醚树脂防蚀涂料进行了改性处理,并用国家标准和人工加速老化试验考察了纳米TiO2的加入对氯醚树脂涂层的附着力、柔韧性、耐冲击、紫外老化等性能的影响,用电化学阻抗法考察了添加纳米TiO2对漆膜防蚀性能的影响.结果表明,添加纳米TiO2对氯醚树脂漆膜的附着力、柔韧性和耐冲击没有明显改善,但能提高漆膜耐紫外老化的性能,漆膜的光泽度也有所提高,纳米TiO2加入适量时还能提高漆膜的防蚀性能.因此,纳米材料在氯醚树脂防蚀涂料中的应用是可行的.     

纳米TiO2的性能、应用及制备方法

纳米TiO2具有独特的光催化性、优异的颜色效应以及紫外线屏蔽等功能，在光催化剂、化妆品、抗紫外线吸收剂、功能陶瓷、气敏传感器件等方面具有广阔的应用前景，国内外文献对纳米TiO2的性质、应用及其制备方法进行了大量的研究报道。本工作对有关纳米TiO2的性能、应用及制备方法研究进行了综述。     

Reflectance properties of pressed Algoflon F6: a replacement reflectance-standard material for Halon

The standard ultraviolet through short-wave infrared (200-2500-nm) diffuse-reflectance material, Halon PTFE, type G-80, is no longer available. Therefore an equivalent diffuse-reflectance standard material must be found. Algoflon F6 is shown here to be an appropriate replacement through the presentation of measurements of various spectral-reflectance properties of Halon and Algoflon F6. The measurements include spectral hemispherical reflectance, spectral bidirectional reflectance factor (BRF), sample BRF repeatability, and sample lifetime.     

一种新型旋翼／机身隔振装置及其性能分析

从降低旋翼动载荷向机身传递的基本目标出发,研究了新型旋翼／机身隔振装置的基本设计思想,给出了设计原则及方法,介绍了反共振装置、波纹板的设计及试验的关键。台架试验表明：该装置能同时实现对桨毂五个交变力素的隔离,其隔振效率及重要指标均达到设计要求     

Excretion of depleted uranium by Gulf War veterans

During the Persian Gulf War, in 1991, approximately 100 US military personnel had potential intakes of depleted uranium (DU), including shrapnel wounds. In 1993, the US government initiated a follow-up study of 33 Gulf War veterans who had been exposed to DU, many of whom contained embedded fragments of DU shrapnel in their bodies. The veterans underwent medical evaluation, whole-body counting, and urinalysis for uranium by kinetic phosphorescence analysis (KPA). Data are available from seven individuals who exceeded the detection limit for whole-body counting and also had elevated urinary uranium. Urinary excretion rates, in microg U g(-1) creatinine, were determined in 1997 and 1999. The body contents, in mg DU, were determined in 1997; it is assumed there were no significant decreases in total body content in the interim. For the 1997 data, the mean fractional excretion was (2.4 +/- 2.8) x 10(-5) g(-1) creatinine, and for the 1999 data, the mean was (1.1 +/- 0.6) x 10(-5) g(-1) creatinine. However, these means are not significantly different, nor is there any correlation of excretion rate with body content. Thus, human data available to date do not provide any basis for determining the effects of particle surface area, composition and solubility, and biological processes such as encapsulation, on the excretion rate.