关于721型分光光度计波长误差的调整

我们在检定721型分光光度计时,常常遇到波长误差超差的情况,下面就此做一些探讨。1一般性波长误差的调整所谓一般性波长误差即在360nm~800nm范围内,高、中、低波长同时是正误差或负误差。经过光源及光斑调整的仪器,应进一步使用干涉滤光片进行校正。即将处于360~500nm、500~600nm、600~700nm、700~800nm波长区间的干涉滤光片,分别垂直置于样品室内的适当位置,并使入射光通过滤光片的有效孔径范围内,自短波长向长波长逐点测出滤光片的波长———透射比示值,求出相应的峰值波长iλ,iλ应与仪器单色器波长度盘示值相符或误差不超过JJG178-96…     

基于分数傅里叶域信号处理的迈克尔逊干涉法测量波长北大核心CSCD

建立了迈克尔逊干涉法测量波长所得条纹图的数学模型,揭示了其线性调频信号(chirp信号)特性,提出了基于分数傅里叶变换信号处理方法对迈克尔逊干涉条纹进行处理,实现了激光波长测量。实验结果表明:该测量方法具有可行性,对于波长范围为400~635 nm的激光,波长测量的平均相对误差约为0.39%。在干涉条纹图被高斯白噪声污损情况下,波长测量的平均相对误差仍然小于1%。     

多波段吸收PC滤光镜片的制备与性能研究

使用染料-高聚物混(dye-polymer)的方法将光吸收染料UV360、VIS532、NIR1064作为功能添加剂分散在聚碳酸酯(PC)中,采用注射成型的方法制备了一种防紫外、防眩光、防980和1 064nm激光波长的多波段吸收PC滤光镜片。研究了光吸收染料在聚碳酸酯中的吸收特性,确定了光吸收染料的添加量,最终制备的PC镜片在250~400nm紫外波段的透过率为0.06%,在400~700nm可见光波段的透过率为14.43%,在980和1 064nm激光波长处的透过率为0.006%和0.003%(吸光度4)。镜片材料的冲击强度为60.4kJ/m2,弯曲强度为120 MPa,力学性能优良。在经过高温、低温和光照环境实验后,镜片的光学性能未发生明显变化,具有良好的应用性能。     

基于Sagnac环形滤波器的多波长掺铥光纤激光器

为了实现2μm波段多波长激光输出,提出并设计了一种基于Sagnac环形滤波结构的多波长掺铥光纤激光器.激光器由波长793 nm的泵浦源、波分复用器、光纤耦合器、保偏光纤、掺铥光纤以及偏振控制器构成,其中Sagnac环形滤波器以及光纤环形镜作为激光器的反射端.实验中,激光器工作阈值为77.5 m W,通过调节偏振控制器,实现了稳定的单波长激光输出.波长为1 852.8 nm的单波长激光输出时,在50 min监测时间内波长最大漂移为0.1 nm,功率最大漂移为0.252 d B,激光3 d B线宽和信噪比分别为0.3 nm和35.7 d B.通过调节偏振控制器,在1 850~1 900 nm光谱范围内实现了1~4波长的激光输出.     

光谱辐射亮度国际比对与结果分析

基于高温黑体辐射源BB3500M,中国计量科学研究院(NIM)自主研制了第四代光谱辐射亮度国家基准装置,波长范围覆盖220~2550nm,以稳定的钨带灯作为传递标准,改善了测量不确定度。黑体辐射源的温度测量溯源至Pt-C和Re-C固定点黑体,在3021 K采用WC-C固定点黑体进行验证,NIM和全俄光学物理计量院(VNIIOFI)之间的测量偏差小于70 mK。采用新基准装置,NIM参加了光谱辐射亮度国际APMP-PR.S6比对。NIM研制了两套入射光学系统,成像倍率分别为0.58和1.00,立体角为0.006sr和0.008sr,采用两套系统复现光谱辐射亮度量值的差异小于±0.40%。APMP-PR.S6比对结果表明:在紫外、可见和近红外波长范围,NIM与参考值的平均相对偏差分别为0.59%、0.44%和0.34%。全部波长范围的平均相对偏差0.46%。在250nm、400nm、800nm、2500nm波长,光谱辐射亮度的测量标准不确定度分别为0.95%、0.50%、0.41%和0.80%。从而验证了第四代光谱辐射亮度国家基准装置的准确性和可靠性。     

HPLC法测定保健食品中维生素K1

本实验建立了保健食品中维生素K1的测定方法。采用Kromasil C18柱,以纯甲醇为流动相,流速1.0mLomin-1,检测波长为248nm。回收率在96~101%之间,RSD(n=6)为2.24%。实验结果表明该方法快速、简便、准确可靠。     

分光光度法测定水中微量的铁离子

在酸性介质中,二价铁离子与邻二氮菲反应生成橙色络合物,最大吸收波长为510nm,铁离子含量在30~150mg·L-1范围内呈良好线性关系,回收率在95%以上,可适用于水中微量铁离子的测定。     

双波长比值法测定苯二酚异构体的含量

利用双波长比值光谱法测定苯二酚异构体的含量。依据邻、间、对苯二酚三组分的比值光谱特征,以对苯二酚为参比组分,选择224nm、277nm作为测定邻苯二酚的波长;以邻苯二酚作为参比组分,选择231nm、284nm作为测定间苯二酚的波长;以间苯二酚作为参比组分,选择220nm、231nm作为测定对苯二酚的波长,测定邻、间、对苯二酚混合样品中三组分含量。邻苯二酚在0.5mg/L～80mg/L,间苯二酚在0.3mg/L～120mg/L,对苯二酚0.4mg/L～80mg/L浓度范围内线性关系良好,平均回收率分别为99.2%,102.8%和101.7%。该方法具有测定波长少、光谱"分离"能力强、计算简单、易于推广等特点。     

废弃玉米苞叶制备碳化硅纳米颗粒

以废弃的玉米苞叶和正硅酸乙酯(TEOS)为原料,硝酸钴为催化剂,在氩气保护气氛下通过碳热还原反应制备出均匀分布的碳化硅纳米颗粒。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和荧光光谱仪(PL)对所得碳化硅进行表征。结果表明:制得的均匀分布的β-SiC纳米颗粒尺寸介于15~60nm。激发波长为290nm时,样品具有最强的发射峰。当激发波长从290nm增加到330nm时,发射峰位置固定在466nm;当激发波长从330nm增加到390nm时,发射峰位置出现了明显的蓝移。     

荧光法测定医用维生素B_2片剂中维生素B_2的含量

研究了荧光分光光度计测定医用维生素B2片剂中维生素B2的含量。其荧光的激发波长为Ex;457 nm,发射波长为Em:528 nm。回收率为96.8%-100.0%,变易系数为2.03%。     

A windowless VUV excilamp

An open windowless excilamp capable of operating on argon (λ ～ 126 nm), krypton (～146 nm), and xenon (～172 nm) dimers is described. The lamp has a total radiating surface area of 23 × 23 = 529 cm². At a total power of ～0.8 W radiated through this area, the average output power density at λ ～ 126 nm is ～1.6 mW/cm² at a distance of 2 cm from the emitting surface. A pulsed discharge between insulator-coated anode and thin wire cathode ensures a high efficiency of the proposed radiation source operating in the vacuum ultraviolet spectral range.     

荧光法同时测定环境水中的As(Ⅲ)和As(V)

研究了一种快速、灵敏的同时测定水中的As(Ⅲ)和As(V)的荧光新方法。在pH=6.5~7.5的缓冲介质中,利用2’,7’-二氯荧光素(DCF)作为荧光试剂,激发波长λex=510nm,发射波长λem=528nm下,As(Ⅲ)和DCF竞争碘,引起荧光强度的增强,从而测定痕量As(Ⅲ)。同时利用L一半胱氨酸还原剂将水中的As(V)还原成As(Ⅲ),从而测定As(Ⅲ)和As(v)的总量,差减间接测定As(V)。As(Ⅲ)浓度在4~180ng/mL范围内,相对荧光强度差值与As(Ⅲ)浓度呈线性关系,线性方程△F=7.82C+0.76,相关系数为o.9991,本法快速、简便、灵敏度高,已用于检测自来水和池塘水中痕量的As(Ⅲ)和As(V),回收率在96%~105%,结果令人满意。     

KrCl and XeCl exciplex glow discharge lamps with an output power of ∼1.5 kW

A high-power multisection cylindrical exciplex lamp pumped by a glow discharge is created. The energy, temporal, and spectral characteristics of the emission from KrCl* (λ～-222 nm) and XeCl* (λ～308 nm) molecules are studied. The average output UV radiation power is 1.6 kW (for 222 nm) and 1.1 kW (for 308 nm) at a power pumping efficiency of up to 14%.     

掺杂SnO2透明导电薄膜电学及光学性能研究

通过实验测量 ｓｏｌ－ｇｅｌ工艺制备的 Ｓｂ掺杂 ＳｎＯ２薄膜载流子浓度、迁移率、电阻率、膜厚,紫外－可见光区透射率、反射率等性质,详细研究了Ｓｂ掺杂ＳｎＯ_２薄膜电学与光学性能．实验发现,薄膜具有良好的透光性和较高导电性,膜内载流子浓度高达１０^２０ｃｍ^－３,电阻率～１０^－２Ω·ｃｍ,透光率高达 ９０％,ＳｎＯ_２膜禁带宽度 Ｅ_ｇ≈３７～３．８０ｅＶ．     

Chloroform Aided Extraction Spectrophotometric Determination of Rhenium Using Thiocyanate Complexing Agent

A new technique is developed for quantitative determination of rhenium in aqueous media containing molybdenum, iron and copper ions. The method seems easier and more accurate than the traditional ones. It consists of the formation of rhenium thiocyanate complex, which is extracted with chloroform at the presence of hydrochloric acid. This complex is a highly visible light absorbent that can easily be detected with the aid of a spectrophotometer. The maximum absorbance (λmax) observed for this complex was in the visible range of 430-435 nm. The experimental results showed that in a concentration range from 0.5-8 mg/L, the absorbance behavior of the rhenium thiocyanate complex is followed to the Beer-Lambert law.     

光学元件聚氨酯抛光特性研究

本文研究了应用于平面光学元件的快速抛光技术,从材料去除率、元件面形和表面粗糙度出发,对快速抛光技术应用于平面大口径元件的加工效果进行了探讨。研究了在快速抛光技术中压力和主轴转速对材料去除率的影响,验证了Preston公式在快速抛光中的适用性,快速抛光技术的去除效率可达10μm/h;其次,研究了聚氨酯抛光元件面形的精度,对于330mm×330mm元件可达～1.0λ（λ=632.8nm）;最后,对快速抛光系统中抛光粉颗粒大小及形态随使用时间的变化进行了观测,并测量了使用300目和500目抛光粉时快速抛光元件表面粗糙度以及其随抛光粉使用时间的变化。     

基于纳米碳点的肿瘤血管抑制剂DX1002特异性定量方法构建

针对肿瘤血管抑制剂DX1002的含量测定,构建一种基于新型纳米碳点材料(CDs)的特异性荧光定量方法。以柠檬酸和尿素为原料,热解法制得碳点(CACCDs),经TEM、IR、UV/Vis、Flu等方法对其进行结构表征。内滤光效应下碳点荧光可被DX1002特异性定量猝灭,CACCDs浓度为250μg/mL时,于λex/λem=400/530处测定猝灭前后的荧光差值(ΔF)。结果表明,DX1002浓度在2.5~75μg/mL范围内与ΔF具良好线性关系(r²=0.9988),检出限为1.16μg/mL,平均加标回收率为101.7%(RSD=2.08%),常见细胞阳离子、微量金属离子、糖类、氨基酸等潜在共存物质及有关物质对测定无干扰,DX1002含量测定的结果(101.3%±1.33%)与HPLC法测定结果(99.4%±1.19%)基本吻合(P>0.05),但较HPLC分析时间快约75倍。该方法快速、灵敏、特异性强,可为建立DX1002高通量特异性体内分析方法提供体外定量的依据。     

Adsorption of avermectin on porous hollow silica nanoparticles by supercritical technology

Porous hollow silica nanoparticles with O.D. of approximately 100 nm and a wall thickness of approximately 10 nm were prepared by using inorganic CaCO3 templates. The produced PHSN were employed as a novel carrier to study the adsorption of avermectin in supercritical carbon dioxide by applying different adsorption pressure, adsorption temperature, adsorption time and volume of cosolvent. The results indicated that while increasing adsorption pressure and time always showed a positive effect on the avermectin adsorption until adsorption saturation is reached, both the adsorption temperature and volume of cosolvent require an optimal value for achieving the maximum adsorption. It was found that the optimal adsorption could be obtained at an adsorption pressure of 15 MPa and an adsorption temperature of 313 K for 90 minutes with 5 ml cosolvent. In addition, the desorption behavior of avermectin from the avermectin-loaded PHSN samples showed a sustained style: approximately 60% of avermectin was released in the first 20 minutes, while the other 40% followed a typical sustained desorption pattern and was dissolved out slowly for a time period of 3000 minutes, which is different from the quick and complete desorption from solid SiO2 carriers.     

Novel robust cellulose-based foam with pH and light dual-response for oil recovery

We fabricated pH and light dual-responsive adsorption materials which could induce the transition of surface wettability between hydrophobicity and hydrophilicity by using ATRP. The structure and morphology of adsorption materials were confirmed by ATR-FTIR, XPS, TGA and SEM. It showed that the modified cellulose (CE)-based foam was hydrophobic, which can adsorb a range of oils and organic solvents in water under pH = 7.0 or visible light irradiation (λ > 500 nm). Meanwhile, the wettability of robust CE-based foam can convert hydrophobicity into hydrophilicity and underwater oleophobicity under pH = 3.0 or UV irradiation (λ = 365 nm), giving rise to release oils and organic solvents. Most important of all, the adsorption and desorption processes of the modified CE-based foam could be switched by external stimuli. Furthermore, the modified CE-based foam was not damaged and still retained original performance after reversible cycle repeated for many times with variation of surface wettability. In short, it indicates that CE-based foam materials with switchable surface wettability are new responsive absorbent materials and have owned potential application in the treatment of oil recovery.     

Synthesis and Characterization of Nanocapsules of α-Fe(NiCoAl) Solid-solution

α-Fe(NiCoAl) solid-solution nanocapsules were prepared with pure powders of Fe, Ni, Co and Al by the plasma arc-discharging using a copper crucible. The shapes of the nanocapsules are in polyhedrons with the core/shell structure. The body centered cubic (BCC) phase is formed in the core. The size of the nanocapsules is in the range of 10～120 nm and the thickness of the shell is 4～11 nm. Saturation magnetization Js=150 Am2/kg and coercivity iHC=24.3 kA/m are achieved for the nanocapsules.