土壤/沉积物中重金属元素分析的前处理技术研究进展

概述了近年来土壤/沉积物样品中重金属元素分析的前处理技术,包括电热板法、微波消解法、高压密闭消解法和碱熔法等,对各种前处理方法的优缺点进行了比较,并对土壤/沉积物样品中重金属元素的前处理技术研究方向进行了展望。     

模式正交性对哈特曼-夏克传感器波前测量等的影响

分析了哈特曼-夏克波前传感器采用模式法重构波前相位算法的数学模型，仿真实验了重构模式之间不正交对重构精度的影响，指出模式之问的不正交不影响算法的实现。在哈特曼一夏克传感器应用模式法进行波前测量和波前校正的过程中，模式之间的正交性并不是算法实现的必要条件，正交化处理算法对波前重构、波前校正精度的提高没有影响。     

在取样法、样品处理和数据评价训练班开幕式的贺辞及有关情况

在取样法、样品处理和数据评价训练班开幕式的贺辞及有关情况梁树权（中国科学院化学研究所，北京市中关村，１０００８０）１前言为多元素和放射性核素分析用的取样法、样品处理和数据评价训练班（Ｔｒａｉｎｉｎｇｃｏｕｒｓｅｆｏｒｓａｍｐｌｉｎｇ，ｓａｍｐｌｅｐｒ...     

ICP-AES法快速测定球团铁矿中的总铁、二氧化硅、氧化钙、氧化镁及三氧化二铝

应用ICP-AES法快速测定球团铁矿中的总铁、二氧化硅、氧化钙、氧化镁及三氧化二铝的含量。对测试仪器条件及元素谱线等相关参数进行实验和优化，对3种样品前处理方法所能达到的测试目标进行实验对比，对基体干扰及方法的准确度和精密度进行研究，并用标准物质验证。     

电感耦合等离子体原子发射光谱法测定防污漆中的铜和锡

本文用电感耦合等离子体原子发射光谱法同时测定防污漆中的铜和锡。对样品的前处理方法进行了探讨，并研究了仪器工作参数、酸度、共存金属元素锌对被测元素的影响，确定了最佳分析条件。     

ICP-AES法测定血红素中铁的含量

本文介绍了应用ICP－AES法测定血红素中铁的含量。对样品的前处理方法进行了探讨，结果表明干灰化法简便、准确。方法的回收率为98.5%－105.0％，相对标准偏差0.997%，结果令人满意。     

光学元件波前梯度的数值计算方法

 惯性约束聚变系统中光学元件的波前梯度均方根是一个关键参数，对其数值计算涉及到的空域处理、频域滤波及梯度算法等关键技术进行了理论分析。分别采用最简单差分算法、中心差分算法、最小二乘拟合算法、“五点法”对实测波前数据进行了梯度均方根值计算。结果表明波前数据的空域处理采用Quad-flip技术较为合适；频域滤波器的选用上应着重考虑滤波的有效性。对于原始波前，4种算法计算梯度均方根值的差别小于0.01 λ/cm(λ=632.8 nm)；而对于截止频率为0.0303 线/mm的低通滤波后波前，其差别小于0.001 λ/cm，该差别对计算结果的影响可以忽略。     

增量维纳滤波法在波前探测解卷积中的应用

一个常规的自适应光学系统通常包含三个重要环节：波前探测、波前校正和波前重构。因此对系统的技术要求非常高,造成系统复杂,成本昂贵。基于哈特曼-夏克波前探测的图像解卷积处理就是“事后”处理的一种,它省去了波前校正环节,使常规的自适应光学系统得到简化,降低了系统成本。其基本原理为对瞬时波面进行短时间曝光探测,同时记录相应的短时间曝光图像,来进行解卷积处理。将增量维纳滤波法应用于基于哈特曼-夏克波前探测的解卷积中,并对室内模拟点源情况下的三组畸变光斑图像数据进行了解卷积恢复处理。结果表明,将增量维纳滤波法应用于基于波前探测的解卷积是完全可行的,在室内模拟点源情况下,恢复的图像可以达到衍射极限分辨力。与维纳滤波相比,它扩展了噪声抑制因子的选取范围,在噪声抑制因子选取不正确的情况下,仍能得到比维纳滤波更好的结果。     

CGNS API和FVM在非结构混合网格计算中的应用

用CGNS API（CFD General Notation System Application Programming Interface）作为非结构混合网格求解器的前处理和后处理，用FVM（Finite Volume Method）作为偏微分方程求解方法．在前处理过程中，用hash表法对内部网格面和边界网格面进行编号，并计算出相应的几何信息，以满足FVM求解器的需要．从FVM求解器计算出来的各种场信息可以写入原来的CGNS文件，该文件可以被许多专业商业后处理软件（如Tecplot，Fluent，CFX等）读取和进行可视化；对于求解器，用基于网格中心的FVM及SIMPLEC（Semi Implicit Methodfor Pressure Linked Equation Consistent）方法求解压力速度耦合．最后给出两个说明算例．     

含氰放射性电镀废液处理技术

冶金工业产生的含氰电镀废液处理方法主要分为以下两类：高浓含氰废液采用酸化法进行口收处理，低浓含氰废液普遍采用氯化氧化法进行处理。文中所处理的对象为高浓度含氰放射性电镀废液，若采用上述方法中的酸化法进行回收，不但成本高、处理设备复杂，而且回收的氰化物含有放射性核素，给后续的储存、使用带来不便；若用氯化法进行氧化处理，不但会增加大量的二次废物，而且给后续处理废水中的核素带来不便。若采用不增加其他杂质的H2O2氧化法，不但需要消耗大量的H2O2，而且增加了二次废物。为了合理、有效的处理此废液，提出TiO2光催化氧化-H2O2氧化-离子交换联合法处理此特种废液。     

Reactive surface treatment for calcium carbonate filler in polypropylene

Calcium carbonate has been modified with three surface modifying systems based upon stearic acid, acrylic acid and a reactive coating comprising acrylic acid with dicumyl peroxide through dry blending. Polypropylene homopolymer was compounded with the coated and uncoated fillers (0 to 65 wt%) through twin screw extrusion. Infrared and extraction investigations showed that the acrylic acid coatings reacted extensively with the filler surface to produce both tightly bound and loosely bound calcium acrylate. Direct evidence for transfer grafting between the calcium acrylate and the polypropylene in the reactive coating was obtained through selective dissolution of the matrix phase and filler with hot xylene and dilute hydrochloric acid, respectively. For coatings without peroxide, complete dissolution of the compound into the inorganic and organic phases was possible, whilst for those with peroxide, an insoluble fraction was obtained. Infrared analysis showed that this was a grafted structure comprising calcium carbonate and polymer. For the filler coating containing acrylic acid with peroxide it was found that the amount of bound polymer at the filler surface was higher for compounds with larger filler loadings indicating a commensurate increase in the extent of the reaction at the filler surface for compounds with higher filler loadings.     

核糖核酸与甲基紫作用机理及含量测定的研究

研究了在pH 6.0的伯瑞坦-罗比森弱酸性缓冲溶液中,小分子甲基紫与生物大分子核糖核酸之间发生强烈静电缔合相互作用,引起分子光谱红移,吸收值变小。甲基紫在最大吸收波长558 nm处的吸收峰强度显著下降,下降程度与核糖核酸的含量呈线性关系,应用光谱法研究了反应体系酸度、甲基紫用量、反应时间对反应速度的影响,确定了试验最佳条件,提出并建立了测定痕量核糖核酸含量的新方法。线性范围为1.0～8.0 μg·mL-1, 检测限为0.52 μg·mL-1,相关系数r为0.999 9,该法简便,快速,具有较高的选择性和灵敏度,对合成样品中核糖核酸的测定令人满意;初步探讨了反应机理,认为,甲基紫分子与凝聚在RNA分子链上的反离子之间发生静电缔合作用,然后,以协同方式与RNA分子发生键合,使甲基紫三苯环平面结构受到破坏,π-电子叠合程度降低,吸收值降低,最大吸收波长红移。     

基于循环平稳信号相干统计量的脉冲星周期估计新方法

讨论了脉冲星的周期估计在脉冲星搜索中的重要性.将脉冲星观测信号建模为二阶循环平稳模型,仿真验证了其合理性.在此基础上,提出了一种基于双谱相干统计量的周期估计新方法,并给出了稳健有效的周期搜索策略以消除其对数据量的敏感性.分别对单脉冲脉冲星(PSR J0437-4715)的实测信号和双脉冲脉冲星(PSR B1821-24)的仿真信号进行了周期估计,实验表明,相比较于常用的傅里叶频谱法,该时域方法直观、有效,在低信噪比情况下仍具有很好的性能,且适用于非连续观测数据.尽管方法运算量较大,但仍然可为微弱脉冲星的周 关键词： 脉冲星 脉冲星搜索 周期估计 循环平稳信号     

流动注射化学发光法测定山奈酚

采用流动注射技术,研究了高锰酸钾-山奈酚-过氧化氢体系的化学发光行为,对影响化学发光强度的因素进行了试验,建立了流动注射化学发光法测定山奈酚的新方法.方法检出限为1×10-10g·mL-1,线性范围为1.0×10-7-1.0×10-4g·mL-1.对1.0×10-6g·mL-1的山奈酚平行测定11次,其RSD为2.1%...     

基于小波变换的木材近红外光谱模型优化及质量追溯

智能化精准获取木材基本信息是木材质量追溯系统信息采集的核心,同时也是木材后期分流、加工、精细化利用的重要依据。旨在探讨基于小波变换的木材近红外光谱(NIRS)去噪及模型优化,研究近红外技术用于木材质量追溯的基础理论与方法,构建基于近红外的木材质量追溯体系。以山杨木材气干密度为例,采用小波变换进行光谱去噪及模型优化,应用偏最小二乘法(PLS)构建了基于近红外光谱技术的山杨木材气干密度定标模型。在此基础上,集成二维码技术,在Matlab环境下,将近红外定标模型预测结果(以木材密度为例)及其他木材相关信息(树种名称、产地、采集单位、数据获取方式等)生成快速响应矩阵码(QR Code),以实现木材信息的有效、快速追溯。同时研究分析了不同纠错等级、字符数、像素下QR码的可读性及有效性。结果显示： (1)当db5小波基分解层为5时,经启发式硬阈值去噪后得到的信噪比(SNR)最大,均方根误差(RMSE)最小,基于小波变换的近红外光谱去噪效果最好,将校正模型决定系数由0.774 8提高到了0.850 1;(2)字符数一定时(本追溯信息的字符数为217),当像素大于100 px×100 px时,QR码的可读性均大于90%;当纠错等级为7%、像素大小为200 px×200 px时,随着字符数由100增加至600,解码率和可读性均为100%。研究表明,基于小波去噪及近红外光谱技术,可以实现木材密度的准确预测,并能有效集成QR码技术,以QR码作为传递木材信息的有效载体,为木材材性信息的无损获取及有效追溯提供了理论依据与技术支撑。     

AAS法测定出口氟石粉中锰的研究

基于出口矿产品氟石粉需要测定锰而建立该方法。该方法是将氟石样品经过氢氟酸去除硅,高氯酸冒烟,冷却后再用盐酸、硼酸加热溶解等处理过程, 标准溶液中需加入与样品相匹配的钙基体进行测定。锰的线性范围为0.09～2.5 μg· mL-1, 测量下限为0.001%。用不同含量水平的实际样品所测定的结果与用ISO高碘酸钠光度法测定的结果一致。该方法的特点是准确可靠、简便可行、易于推广。     

激光熔融拉锥型微型光纤耦合器设计

采用聚焦红外激光光束进行熔融加热,针对激光熔融拉锥型光纤耦合器设计了一种熔融区域长度为200 μm的微型光纤耦合器.使用光束传输法对拉锥长度和耦合区域的宽度进行了模拟并与实验结果比较,在1320 μm的拉锥长度和14 μm的耦合宽度处找到了最优化且低损耗的耦合器尺寸配置.     

A calibration-free model for laser-induced breakdown spectroscopy using non-gated detectors

Calibration-free (CF) laser-induced breakdown spectroscopy (LIBS) is normally only applicable for gated detectors due to its dependence on the assumption of a steady-state plasma. However, most currently available LIBS systems are equipped with non-gated detectors such as charge-coupled device (CCD), which degrades the accuracy of CF method. In this paper, the reason for the less satisfactory quantification performance of CF for LIBS with non-gated detectors was clarified and a time-integration calibration-free (TICF) model was proposed for applications with non-gated detectors. It was based on an assumed temporal profile of plasma properties, including temperature and electron density, obtained from another pre-experiment. The line intensity at different time during the signal collection time window was estimated with self-absorption correction according to the temporal profile of the plasma properties. The proposed model was validated on titanium alloys and compared with traditional CF. The accuracy of elemental concentration measurement was improved significantly: the average relative error of aluminum and vanadium decreased from 6.07% and 22.34% to 2.01% and 1.92%, respectively. The quantification results showed that TICF method was able to extend the applicability of CF to LIBS with non-gated detectors.     

Neutron detection with LiCaAlF6 scintillator doped with 3d-transition metal ions

Capability of thermal neutron detection was examined for LiCaAlF₆ (LiCAF) scintillators doped with 3d-transition metal ions. Their radioluminescence spectra were measured with an 241-Am source to simulate ⁶Li(n, α)³H reaction. The sufficiently intense radioluminescence was observed for the Mn, Co and Cu dopants, while only a weak one was observed for Ti, V, Fe and Ni. A Mn doped LiCAF crystal, which showed the highest radioluminescence intensity, was coupled with a Si avalanche photodiode for the examination of its neutron response. It was confirmed that the average current of the photodiode clearly increased under excitation with 13.5 meV neutron flux.     

Determination of calcium and magnesium in the Solanaceae plant by near infrared spectroscopy combined with interval combination optimization algorithm

Determination of the content of inorganic nutrients was done as part of a project to improve crop yield by use of fertilizers. Near-infrared spectroscopy coupled with interval combination optimization was used to determine the inorganic nutrients of calcium and magnesium in the Solanaceae plant. Interval combination optimization was employed to choose effective intervals with the merit of assigning smaller weights to less significant variables. Compared with full spectrum partial least squares regression, interval combination optimization improved the predictive accuracy and precision for both calcium and magnesium. The result was a high predictive ability for calcium, with a root mean squared error prediction of 0.159%, and for magnesium, with a root mean squared error prediction of 0.064%. In this study, the superiority of interval combination optimization over full spectrum partial least squares was shown in the aspects of effective variables and accurate results. Near-infrared spectroscopy combined with interval combination optimization was efficient for the determination of inorganic nutrients, calcium and magnesium, in the Solanaceae plant.