胶束电动毛细管色谱法分析玫瑰纯露中的苯乙醇

玫瑰纯露是玫瑰提取精油后的重要副产物,是玫瑰精油的饱和水溶液,不仅含有植物水溶活性成分,同时也保留了精油的芳香成分,含有矿物养分,具有抗衰老、清除自由基,抗过敏、抗菌、消炎、防紫外线损伤等功效,是继玫瑰精油之后护肤领域重要的优势产品之一,但目前尚无关于其质量控制的标准,市售产品质量参差不齐。为此,该研究发展了一种胶束电动毛细管色谱法用于快速检测玫瑰纯露中的指标成分苯乙醇。在实验过程中分析物的定性通过标准物质加标及紫外吸收可见光谱图比对确认。实验对缓冲溶液中硼砂浓度、十二烷基硫酸钠（SDS）浓度、分离电压、进样条件、检测条件等影响检测的关键因素进行了考察。在优化条件（分离缓冲溶液10 mmol/L Na₂ B₂ O₇ +15 mmol/L SDS,分离电压+20 kV,检测波长208 nm,进样5 kPa,5 s）下,玫瑰纯露样品在7 min内可以完成检测。本方法对苯乙醇检测的线性范围为0.50~1000 mg/L,线性相关系数（r ² ）为0.9990,检出限（LOD,S/N =3）为0.091 mg/L,定量限（LOQ,S/N =10）为0.35 mg/L,实际样品加标回收率为98.1%~102.7%（加标水平10、100、500 g/L）,相对标准偏差（RSD）≤2.8%。结果表明,该方法为玫瑰纯露及其制品的质量控制提供了一种简便、快速、灵敏、稳定的分析方法。     

Bending of uniformly loaded rectangular plates with two adjacent edges clamped, one edge simply supported and the other edge free

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Low-Threshold Mid-Infrared Optical Parametric Oscillator Using Periodically Poled LiNbO33

We report the generation of tunable mid-infrared optical pulses using all-solid-state pumped optical parametri coscillator in a periodically poled lithium niobate. Several ways were used to lower the threshold, resulting in a mean threshold as low as 6.5mW and an achievement of wavelength conversion in the 2.77-4.04μm spectral range. Continuous tuning range from 2.97 to 3.25μm was achieved. The maximum idler output power of 466mW at the wavelength of 3.41μm was obtained, which represents an optical-to-optical conversion efficiency of 19% from incident pump power to the idler output.     

孔壁含有沸石次级结构单元的MCM-48的合成及催化研究

以双表面活性剂（双极性头表面活性剂和三乙醇胺）为模板，以含有沸石次级结构单元的溶胶为前驱体，在碱性条件下合成了新型介孔分子筛MCM 48。研究了沸石前驱体和三乙醇胺对产物MCM 48形成的影响，XRD和TEM表征结果表明，样品具有较高的结晶度和规则的孔径；FTIR和N2吸附表征结果表明，产物MCM 48的孔壁中含有沸石的次级结构单元，从而使得样品具有更大的比表面积。产物的重芳烃轻质化反应催化活性表明，实验样品对重芳烃的转化率比常规的MCM 48高，转化率约高出11%，进一步证明了实验样品的孔壁中含有沸石的结构单元。     

一种测定橡胶杨氏模量的方法

大学物理测量金属杨氏模量实验通常采用拉伸法和梁弯曲法, 但是该种方法在进行实验的过程中存在 设备难以调节, 读数存在误差, 实验的成本较高等缺点. 而且该设备对测量非金属的杨氏模量无法操作. 为了使该实 验问题具体化, 实验仪器简单化, 实验现象明显可靠, 本文介绍了一种测量非金属杨氏模量的简易实验装置     

Mid—Infrared Optical Parametric Oscillator Based on All—Solid—State—Pumped Periodically Poled LiNbO

We report the tunable mid-infrared generation with a periodically poled LinbO3(PPLN).Using an all-solid-state pumped Nd:YVO4 laser as the pump source and a PPLN nonlinear crystal with grating periods of 28.2-30.8μm,we have achieved wavelength conversion in the 2.90-4.05μm spectral range by period tuning.The use of confocal cavity design has brought a compact,all-solid-state configuration with an average output powers of idler up to -200mW.The maximum power of 277mW was obtained at the wavelength of 3.35um.     

Mid-infrared generation based on a periodically poled LiNbO3 optical parametric oscillator

We report a nanosecond Nd:YVO_4-pumped optical parametric oscillator (OPO) based on periodically poled LiNbO_3 (PPLN). Tuning is achieved in this experiment by varying the temperature and period of the PPLN. The design of double-pass singly resonant oscillator (DSRO) and confocal cavity enables the OPO threshold to be lowered considerably, resulting in a simple, compact, all-solid-state configuration with the mid-infrared idler powers of up to 466mW at 3.41μm.     

环己烷氧化微孔催化剂的研究进展

环己烷氧化是化工生产中的重要反应之一,其氧化产物为重要的化工生产中间体,因此开发高效的环己烷氧化多相催化剂体系具有重要的理论意义和应用前景。本文综述了国内外环己烷选择氧化微孔催化剂的研究进展,分别对Y沸石、ZSM-5沸石及MOFs三大类微孔催化剂体系的组成及催化性能进行了介绍,最后展望了环己烷多相催化体系的发展趋势。     

用等厚干涉测液体的折射率

在等厚干涉的实验中,加入了用劈尖干涉对比法测液体折射率的内容,在不改变劈尖膜的条件下,同时测得空气膜和液体膜的干涉条纹宽度,从而可方便地求出液体的折射率,也使得等厚干涉的实验内容更加丰富和充实．     

环氧/氟碳复合涂层的制备及其耐磨、防腐性能

为提高氟碳树脂涂层在金属基体上的疏水性和耐磨、防腐性能,采用简单共混方法制备了环氧树脂(EP)改性氟碳树脂(FEVE)复合涂层EP/FEVE.采用傅里叶变换红外光谱(FT-IR)确定复合涂层的组成和结构,并基于干摩擦和模拟海水(3.5％NaCl溶液)摩擦测试与电化学阻抗谱(EIS)测试研究了复合涂层的耐磨、防腐性能及机...