一种二元溶液折射率的计算方法

在20℃下配制了一系列浓度的丙三醇—乙醇溶液,测定了各溶液的密度ρ与折射率n。用一种电磁感应原理导出的计算方法n=1+ρ(x1D1+x2D2)对这些丙三醇—乙醇溶液的折射率进行了计算,结果表明,此方法之折射率计算值与实测值符合很好。     

计算光谱配位滴定法同时测定钙和镁

建立了一种将光谱配位滴定分析法与化学计量学相结合同时测定混合金属离子的新方法。在这种方法中,滴定剂是由EDTA和两种指示剂组成的混合溶液。滴定过程中滴定剂的加入体积和滴定反应进程可由吸收光谱通过计算同时获得,并进一步得到滴定曲线。应用滴定曲线可建立相应的矩阵方程,从而可应用主成分回归法计算金属混合物中各组分的浓度。该方法只需要光谱信息就可得到分析结果,免去了对体积的计量,因此方法简便,准确。应用该方法以孔雀绿和Cu-PAN为指示剂对钙和镁的混合溶液进行了同时测定,结果满意。     

灿烂甲酚蓝褪色光度法快速测定强酸的pH值

利用灿烂甲酚蓝在强酸条件下(0＜pH＜1.0)吸光度随溶液中H 浓度的升高而有规律的下降,提出一种快速测定溶液酸度的分光光度法.该法具有很好的精密度,10次测定结果的相对标准偏差为0.54%.与国标法(碳酸钠滴定法)相比,相对误差在2%-5%之间,具有较好的准确性.该法简单快速,消耗试剂少,成功用于浓盐酸和浓硫酸浓度的测定.     

流动注射抑制化学发光法测定痕量强力霉素

基于在NaOH介质中 ,强力霉素对Luminol KMnO4 体系发光反应具有强烈的抑制作用 ,建立起流动注射抑制化学发光测定痕量强力霉素的新方法。强力霉素在 0 0 0 5～ 5 0 μg·mL- 1 浓度范围内 ,采用不同的KMnO4 溶液浓度 ,分段建立起抑制化学发光强度与其浓度间良好的线性关系 ,方法的检出限为 2 0×10 - 3μg·mL- 1 。该方法可用于药片中强力霉素含量的测定     

CH3I分子的光解离的自旋-轨道从头计算

采用从头计算二阶自旋-轨道多组态准简并微扰理论计算了碘代甲烷CH3I分子与基态2I03/2和激发态2I0#1/2原子解离极限相关联的势能曲线.计算了CH3I分子的吸收谱,分析了CH3I分子的光解离过程,并估计了激发态碘原子2I0#3/2的量子产额.计算结果表明.该方法可用以解释光解离实验结果.     

基于图像透光率的粉尘浓度测量算法研究

为了实时在线监测颗粒物料在装卸和运输过程中所产生粉尘的浓度,提高粉尘浓度测量结果的精确性与可靠性,提出了一种基于图像透光率特征值计算的粉尘浓度测量算法。通过搭建粉尘浓度视觉测量实验平台,采集粉尘图像,再提取粉尘图像的透光率特征,以暗通道理论为基础,结合图像饱和度与亮度信息对粉尘图像透光率值进行计算,并采用多项式拟合的方式建立了粉尘浓度与图像透光率之间的映射关系,实现了粉尘浓度的高效率、高精度测量。研究结果表明:该算法不仅能有效地测量出粉尘浓度,且平均相对误差仅为7.77%,精确度得到有效提高,测量范围更大。     

激光等离子体光谱法测定水溶液中钠

建立了一套激光等离子体光谱测量装置 ,测定溶液中不同浓度 Na的 5 89.0 nm谱线强度 ,得到浓度 -强度校准曲线。浓度 0 .1 %时的最大相对误差为 9.1 3%。对氯化钠生理盐水进行了测定 ,结果吻合得很好。     

基于超声相位差法的乙醇汽油浓度测量仪的研制

提出了超声相位差法测定乙醇汽油溶液浓度的新方法,根据该方法设计并制作了超声在线测定仪.利用该仪器建立了温度在290 K时乙醇体积浓度在3％ ～24％的乙醇汽油溶液浓度与相位差之间的关系式.实验结果表明,该超声测定仪能够实时和精确地测定乙醇汽油溶液中乙醇体积浓度,该仪器为精确测量车用乙醇汽油和其他二元溶液开辟了新途径.     

摩尔电导率与浓度关系模型的探讨

基于强电解质溶液摩尔电导率实验测定数据的研究 ,提出强电解质在浓度小于 0 .1 0 0 0 mol· L-1 时 ,计算在不同浓度下强电解质的摩尔电导率和极限摩尔电导率的经验方程Λm=Λ0m-α C βC分别对 89种强电解质和 HAc、NH3 · H2 O和 n- HOOCC3 H7弱电解质的极限摩尔电导率进行计算 ,改进后关系模型的计算结果与推荐值能很好的吻合 ,总体误差小于科尔劳乌施经验方程。在电导测定应用研究中 ,简化了实验数据过程 ,结果更准确、更可靠。     

模式滤光法测定蔗糖

在流速为0.76mL/min的条件下,利用模式滤光法在线测定了不同浓度的蔗糖溶液,其响应范围为0-60.0％(w/w),模式滤光强度与蔗糖溶液浓度呈线性关系,线性方程为I=3673-5249C,线性相关系数r=0.9992.考察了该传感器的重现性和精密度,并对蔗糖实际样品进行了加标回收率的测定,回收率在92.2％-105.1％之间.     

类金刚石薄膜红外光学常数的计算机拟合

报道了一种对类金刚石薄膜红外透射率曲线最小二乘法拟合的方法，确定类金刚石薄膜的红外光学常数－折射率、吸收系数以及薄膜厚度及表面粗糙度。介绍了相应的数学模型，并给出了对类金刚石薄膜样品的实验测及拟合结果。     

旋涂法制备WO3薄膜电致变色性能

"智能窗"大规模推广顺应可持续发展潮流,三氧化钨(WO_3)是生产"智能窗"的一种重要电致变色材料,但调控WO_3薄膜电致变色性能机制仍待进一步研究。采用旋涂法制备WO_3薄膜,重点研究了溶液浓度和旋涂次数对调控WO_3薄膜电致变色性能的影响。通过表面轮廓仪测量薄膜厚度,X射线衍射(XRD)测量薄膜结晶情况,原子力显微镜(AFM)和扫描电子显微镜(SEM)分析薄膜表面形貌,光谱仪测量薄膜初始态、着色态和褪色态的透射率。实验结果表明,随着溶液浓度增加(0. 2～1. 0 mol/L),薄膜厚度从9. 7 nm增加到33. 3 nm,透射率调制能力从0%提升到37. 0%;多次旋涂薄膜厚度线性增长,线性拟合优度(R~2)达0. 98,5次旋涂后透射率调制能力达51. 3%。改变溶液浓度和旋涂次数都是调控薄膜透射率调制能力的有效手段,精准调控薄膜透射率调制能力对设计不同应用场景的电致变色器件具有重大意义。     

仪器分辨率对氧气A带被动测距的影响分析

透过率的计算是红外目标被动测距技术的核心,其精度直接影响到被测距离的精度,而仪器分辨率又直接影响到光谱信号的精度。为了研究光谱仪器分辨率对带平均透过率的影响,选用氧气A带为研究对象,采用基线拟合方式计算被测目标的带平均透过率,利用随机Malkmus模型计算被测目标距离,从而获得仪器分辨率对被动测距的影响。为此,搭建了被动测距实验系统,通过对卤素灯光源在不同距离的光谱测量,验证仪器分辨率对带平均模式被动测距的影响。首先,介绍氧气A带透过率的计算方法,计算理论值;以卤素灯为光源,利用光谱仪分别测量相同距离不同分辨率的光谱曲线,计算实测大气透过率,分析光谱分辨率对单谱线的影响;然后,在分析比较透过率模型和实测透过率谱线的基础上,对透过率计算模型进行拟合、校正,验证光谱分辨率对带模型的影响。对于单条谱线,仪器的不同分辨率可测得的谱线区别较大,而对带平均谱线,相同波数点的光谱信号取平均,获得平均效应,使得被测谱线几乎没有变化;分辨率的模型选择需根据不同的应用场合、不同的精度要求选择合适的分辨率。实验结果表明：分辨率对单谱线的透过率影响较大,随着分辨率的降低,被捕获的光谱信息点取值越少,被测目标距离相关系数越小;分辨率对带平均透过率的计算影响较小,不同分辨率下测得的目标距离,几乎重合;而仪器分辨率越高则测量时间越长,当使用带平均透过率计算被测目标距离,在精度要求范围内,可以适当降低仪器分辨率,从而极大地提高测量速度,并达到测量实时性,同时降低系统搭建的成本。该结论可为透过率测量的应用提供依据。     

Z-scan analysis of high-order nonlinear refraction effect induced by using elliptic Gaussian beam

The irradiance of an elliptic Gaussian beam that is high enough to excite high-order nonlinear refraction effect is used to calculate the normalized on-axis transmittance function in the z-scan technique by introducing complex beam parameters which make the calculation simpler. The transmittance formula is applied to the first-, first two-, and first three-order nonlinearities. Numerical evaluation shows that the symmetry no longer holds when using an elliptic Gaussian beam instead of a circular Gaussian beam. A distortion is observed in the central part of the curve, which decreases as ellipticity increases. Moreover, the variation of the normalized peak-valley difference decreases as ellipticity decreases.     

A Fourier series solution for the transverse vibration response of a beam with a viscous boundary

This paper presents the generalized Fourier series solution for the transverse vibration of a beam subjected to a viscous boundary. The model of the system produces a non-self-adjoint eigenvalue-like problem which does not yield orthogonal eigenfunctions; therefore, such functions cannot be used to calculate the coefficients of expansion in the Fourier series. Furthermore, the eigenfunctions and eigenvalues are complex valued. Nevertheless, the eigenfunctions can be utilized if the space of the operator is extended and a suitable inner product is defined. The methodology presented in this paper utilizes Hilbert space methods and is applicable in general to other problems of this type. As an adjunct to the theoretical discussion, the results from numerical simulations are presented.     

Superhydrophobic and transparent ZnO thin films synthesized by spray pyrolysis technique

Superhydrophobic and transparent zinc oxide (ZnO) thin films were deposited by a simple and cost effective spray pyrolysis technique (SPT) onto the glass substrates at 723 K from an aqueous zinc acetate precursor solution. The solution concentration was varied from 0.1 to 0.4 M and its effect on structural, morphological, wetting and optical properties of ZnO thin films was studied. The synthesized films were found to be polycrystalline, with preferential growth along c-axis. A slight improvement in the crystallite size and texture coefficient is observed as the concentration of the solution is increased. SEM micrographs show the uniform distribution of spherical grains of about 60-80 nm grain size. The films were specular and highly transparent with average transmittance of about 85%. The spectrum shows sharp absorption band edge at 381 nm, corresponding to optical gap of 3.25 eV. The samples of texture coefficient less than 90% and roughness less than 75 nm are hydrophobic and above these values they become superhydrophobic in nature. The hydrophobicity coupled with high transmittance is of great importance in commercial application such as transparent self-cleaning surfaces, anti-fog, anti-snow, fluid microchips and microreactors.     

Study of the process e+e-→π+π-π0π0 at energies √s< 1 GeV

In an experiment with the Spherical Neutral Detector at VEPP-2M collider the cross section of the process e+e-→π+π-π0π0 was measured. At energies √s < 920 MeV this cross section was measured for the first time. The energy dependence of the cross section is well discribed by the vector dominance model with contributions from ρ, ρ' ρ", mesons. The decay probability ρ→π+π-π0π0was found to be Bρ = (1.60±0.74±0.18)×10-5. The upper limit for the decay ω→π+π-π0π0 was improved by two orders of magnitude compared to the previous measurements and is Bω < 2 × 10-4 at 90% confidence level.     

微波辅助碱解荧光分光光度法快速测定河豚毒素含量

建立了一种快速、简便、灵敏地测定河豚毒素的新方法。在水和异丙醇混合碱性溶液中对河豚毒素进行微波碱解,通过测定碱解产物的量来间接测定河豚毒素的含量。结果表明:C9碱的最大激发波长为380nm,最大发射波长为496 nm,其在0.1~10μmol.L-1的浓度范围内与荧光强度呈线性关系,相关系数r=0.999 1,检测限为0.05μmol.L-1,比文献报道降低近20倍。该方法快速、灵敏和准确,可用于河豚毒素的定量检测。     

Influence of aging time of the starting solution on the physical properties of fluorine doped zinc oxide films deposited by a simplified spray pyrolysis technique

Fluorine doped zinc oxide (FZO) films were fabricated from fresh and aged (4, 8, 12 and 16 days) starting solutions using a simplified and low cost spray pyrolysis technique. The X-ray diffraction study showed that the preferential orientation is along the (0 0 2) plane for all the films irrespective of the age of the solution. The crystallite size calculated using the Scherrer’s formula is comparatively smaller only for the film prepared from the starting solution having aging time 4 days which may be due to the efficient incorporation of fluorine atoms into the ZnO lattice. This phenomenon is confirmed by the minimum resistivity value (3.14 × 10⁻² Ω cm) obtained in this particular case. The visible transmittance and the optical band gap values are found to be in the range of 63–83% and 3.20–3.31 eV, respectively. The optical transmittance is found to decrease gradually as the aging time of the solution increases and the optical band gap is found to be slightly higher in the case of the film prepared from the fourth day solution. The scanning electron microscopy results depicted that the microstructure of ZnO:F films are largely influenced by the aging of the starting solution.     

Limitation of semi-empirical mo-calculations in deriving charge densities ρ(0) in iron-oxygen compounds

For fifteen iron-oxygen compounds we carry out semi-empirical MO cluster calculations. The derived electronic structure is used to calculate electron charge densities ρ(0) and electric field gradients V_pq at the iron nucleus. The ρ(0)-values correlate with experimental isomer shifts δ, however, extreme cases like the Fe(VI)-compound BaFeO₄ are beyond the scope of accuracy of our method. We discuss variations of our calculational method, with one of them leading to ρ(0)-values for all fifteen compounds (including BaFeO₄) which satisfy the relation Δδ = αΔρ(0). The isomer shift calibration constant is in the range -0.195 mms^?1a₀³ to -0.25 mms^?1a₀³. Calculated quadrupole splittings are comparable with experimental data.