Differential uptake of U,Mo and Cu,by roots,stalks and seeds of oats grown on uranium‐rich soils

The uptake of U, Mo and Cu by oats grown in high uranium containing soils was investigated. Roots of the plant were found to constitute an effective barrier to U uptake, while that of Mo was pH dependent. Cu concentrations in the plant were independent of those of the other two metals.     

Control of interior surface materials for speech privacy in high‐speed train cabins

The effect of interior materials with various absorption coefficients on speech privacy was investigated in a 1:10 scale model of one high‐speed train cabin geometry. The speech transmission index (STI) and privacy distance (r_P) were measured in the train cabin to quantify speech privacy. Measurement cases were selected for the ceiling, sidewall, and front and back walls and were classified as high‐, medium‐ and low‐absorption coefficient cases. Interior materials with high absorption coefficients yielded a low r_P, and the ceiling had the largest impact on both the STI and r_P among the interior elements. Combinations of the three cases were measured, and the maximum reduction in r_P by the absorptive surfaces was 2.4 m, which exceeds the space between two rows of chairs in the high‐speed train. Additionally, the contribution of the interior elements to speech privacy was analyzed using recorded impulse responses and a multiple regression model for r_P using the equivalent absorption area. The analysis confirmed that the ceiling was the most important interior element for improving speech privacy. These results can be used to find the relative decrease in r_P in the acoustic design of interior materials to improve speech privacy in train cabins.     

Direct Interband Light Absorption in Strongly Prolated Ellipsoidal Quantum Dots’ Ensemble

Within the framework of adiabatic approximation, the energy levels and direct interband light absorption in a strongly prolated ellipsoidal quantum dot are studied. Analytical expressions for the particle energy spectrum and absorption threshold frequencies in three regimes of quantization are obtained. Selection rules for quantum transitions are revealed. Absorption edge and absorption coefficient for three regimes of size quantization (SQ) are also considered. To facilitate the comparison of obtained results with the probable experimental data, size dispersion distribution of growing quantum dots by the small semiaxe in the regimes of strong and weak SQ by two experimentally realizing distribution functions have been taken into account. Distribution functions of Lifshits–Slezov and Gaussian have been considered.     

用分光光度方法测定建筑材料表面的太阳光-热参数

利用分光光度计对建筑材料表面,对紫外到近红外线范围(240～15000nm)内的正分光透射比、正分光反射比进行测定.另外,还利用积分球对紫外到红外线范围(240～2200nm)内的漫射比谱进行测定,同时将测定结果与正分光透射比、反射比进行比较,并计算出太阳吸收比及热放射比.     

Synthesis and Self-Organization of Fluorene-Conjugated Bisimidazolylporphyrin and Its Optical Properties

A conjugated-bisimidazolylporphyrin bridged by bis(ethynylfluorene) was synthesized and organized into linear polymer through self-coordination having mean molecular weights, M_w and M_n, of ~2.1 × 10⁵ Da and ~1.6 × 10⁵ Da, respectively. A large two-photon absorption cross section value of 3.4 × 10⁵ GM (per dimer unit) was observed. This value was comparable to that of the previously reported self-assembled linear polymer consisting of butadiyne-bridged imidazolylporphyrins. The two-photon absorption properties could be controlled by tuning the wavelength and absorption intensity of the one-photon absorption.     

多孔橡胶材料声传递损失性能分析：模型描述

研究带有无孔薄覆盖层的多孔橡胶板构件的声传递损失特性,考察了从低频、中频到高频范围内,不同结构参数和材料特性对多孔橡胶材料隔声性能的影响.这一部分建立了多孔橡胶板构件的有限元（FE）与统计能量（SEA）混合分析模型.在仿真模型中,多孔橡胶板边界条件为固支连接,在多孔橡胶板模型的一侧有散射声场作为激励,在另外一侧有半无限声场,用以计算和预测其声传递损失.数值结果与文献进行比较,结果显示该模型具有较好的可靠性.     

火焰原子吸收分光光度法测定银盲样不确定度分析

用火焰原子吸收分光光度法对银盲样(204204)进行测定,分析测定结果不确定度主要来源,计算合成标准不确定度和扩展不确定度,最后给出测试结果表述方式。     

A water-soluble D–π–A chromophore based on dipicolinic acid: Synthesis, pH-dependent spectral properties and two-photon fluorescence cell imaging

The presence of two carboxylic acid groups and two hydroxyl groups within the novel dye, (E)-4-(4-bis(2-hydroxyethyl)amino)styryl)pyridine-2,6-dicarboxylic acid, resulted in good water solubility. The compound's UV absorption and photoluminescence spectra were each highly pH sensitive in acidic solutions and two isobestic points were observed. The TPA cross-section coefficient and two-photon fluorescence cell imaging of the dye were investigated.     

原子吸收法测定代森锌和福美锌

文章建立了代森锌和福美锌含量的原子吸收测定方法。代森锌和福美锌在酸性热溶液中分解,通过非吸收线法确定不存在非特征衰减,在锌元素共振吸收波长213.9 nm下测定样品溶液中锌元素含量,用锌元素换算得到代森锌和福美锌含量。实验结果表明,该方法的测定代森锌标准偏差为0.0017,变异系数为1.49%,平均回收率为99.3%,...     

涂层中伴有化学反应的传质动力学模型及解析解

有害液体在均匀有界固体介质中的扩散通常是一个伴有化学反应的传质过程，本文采用拉普拉斯交换法对其动力学方程进行了新的求解，得出了吸收过程的解析解。通过定义标准函数err(x)及反函数aer(x)，推导出当降解速率常数k=0时扩散系数D的精确解，理论误差为O．以芥子气在醇酸漆涂层中的传递为例，验证得该方法与实验值的标准差为σ=1.95×10-10 cm2/S，其精度远远高于常规方法。在此基础上，求出了液体在涂层中的吸收量、扩散通量，得到了它们的时空分布规律，分析了降解速率常数k对它们的影响。丈章更为准确、系统地描述了有害液体在涂层中的吸收规律，所给出的扩散系数计算方法更加简洁、精确，对有害物质的洗消、危害评估及相应措施的制定提供了理论依据。