应用氢化物-原子荧光法测定大蒜中硒

应用氢化物-原子荧光法测定大蒜中硒，选定了其最佳测定条件，对还原剂的浓度、酸的种类和浓度、干扰元素的消除等进行了研究。同时应用氢化物-原子荧光法和氢化物-原子吸收法进行了仪器比对实验。结果表明，氢化物-原子荧光法测定大蒜中硒，其方法检出限1．112μg／L，相对标准偏差(RSD)2．6％，具有经济实用、操作简便、快速、灵敏度和选择性好、准确等优点。     

基体匹配——火焰原子吸收法测定钴酸锂中杂质元素

本文采用标准系列钴酸锂基体匹配,用1＋1盐酸溶解,在1％的盐酸介质中,用火焰原子吸收法,测定了钴酸锂中钾、钠、钙、镁、铜、铅、锌、铁、锰、镍等微量杂质含量。通过试验,确定了溶剂和介质的用量;对释放剂SrCl,的加入量进行了实验,选择了最佳加入量;对溶剂和样品中的共存元素进行了干扰实验。各元素的检出限分别为：钾：0．005μg／mL,钠：0．004μg／mL,钙：0．009μg／mL,镁：0．005μg／mL,铜：0．005μg／mL,铅：0．019μg／mL,锌：0．009μg／mL,铁：0．0151μg／mL,锰：0．005μg／mL,镍：0．012μg／mL,样品加标回收率在98—104％之间,相对标准偏差（RSD）为：0．96-9％,方法简便、快捷,仪器低廉,易于普及,适于钴酸锂中的微量元素检测。     

原子捕集-火焰原子吸收光谱法测定中草药中痕量铬

研究了影响原子捕集－火焰原子吸收光谱法测定中草药中痕量铬的各种 实验条件。在最佳实验条件下，捕集3min，铬的特征浓度为5．24ng/mL，检出限为3．57ng/mL，分别比常规火焰原子吸收法提高了26倍和11倍。本方法用于中草药中铬的测定，相对标准偏差（RSD）为2．1％，回收率在87．4％－110．6％之间。     

水冷式不锈钢管原子捕集—火焰原子吸收分光光度法测定水中的铬

前言原子捕集技术是一种在火焰中浓集待测元素的分析技术。它自1976年提出以来,国内外陆续出现报导。本文作者使用国产WYX-401型原子吸收分光光度计,在其燃烧器上方加自制不锈钢管原子捕集器,测定水中铬。其灵敏度为7.1×10~(-5)μg·mol~(-1)/1％吸收,比常规火焰原子吸收法灵敏度提高478倍,检出极限4.0×10~(-4)μg·ml~(-1)比常规法降低100倍。变异系数8.7％,测样回收率90％。用高氯酸铵涂层不锈钢管原子捕集法,测定灵敏度又有所提高。     

原子吸收法测定槐花和香椿芽中微量元素含量

用灰化法处理样品，配制混合标准系列溶液，采用空气-乙炔火焰原子吸收法在同一试液中测定10种微量元素含量。建立了优化的仪器测试条件，方法的回收率均在97．3％～102．1％，RSD为1．1％～2．5％，测定方法简便、灵敏、准确，结果满意。     

火焰原子吸收光谱法测定环境样品中的锶

介绍了用乙炔-空气原子吸收光谱法测定水系沉积物中的痕量锶。实验中考察了共存离子铝、钙、铁、钾及高氯酸根对锶测定的影响，并以2000μg／mL镧为基体改进剂来消除这些共存离子的干扰；采用该方法分析了标准参比样品，结果令人满意。火焰原子吸收光谱法准确、可靠、灵敏度高，为测定环境样品中的锶提供了一种简便的方法。     

非线性拟合3-磁场可调塞曼石墨炉原子吸收法测定鱼肉中的镉

采用非线性拟合3-磁场可调塞曼横向加热石墨炉原子吸收法测定鱼肉中的镉，以NH4H2PO4作为化学改进剂，实验了3-磁场可调塞曼技术和非线性拟合技术对方法检出限、线性范围和准确度的影响，并优化了实验条件。实验结果表明，线性范围显著提高，为0-400μg／L；特征浓度为0．0474μg/L和0．1491μg/L；检出限为0．3μg／kg；回收率在92％～98％之间，RSD为2．0％。     

作业场所空气中五羰基铁的火焰原子吸收测定方法研究

[目的]建立作业场所空气中五羰基铁的火焰原子吸收测定方法。[方法]微孔滤膜采集作业场所空气样品，样品经湿法消化后，原子吸收法测定。[结果]空气中五羰基铁浓度（按铁计）在0．067mg／m^3～1．67mg／m^3，变异系数均小于10％；回归方程Y=0．09718x＋0．0002，r=0．9995；检出限0．020μg／mL；回收率大于等于90％。[结论]本方法适于作业场所空气中五羰基铁的测定。     

火焰原子吸收法测定绿化型芽苗菜中的痕量镉

采用微波消解，经巯基棉分离和富集后，以火焰原子吸收法测定，测定的最低检出限为0．004μg／g，回收率在95．0％～103％，RSD〈4．53％。     

流动注射在线微柱富集—火焰原子吸收法快速测定矿样中的金

本文建立了以饱和溴水、氯化钠、硝酸混合溶剂溶解试样,在线流动注射-纤维微柱分离富集-火焰原子吸收快速测定金的方法,试验了金在流动注射中分离富集的最佳条件,测定的灵敏度为0.08ng/mL/1%吸收,检出限为0.07ng/mL,测定的精密度为2.8%,分析速度为60个/h,方法适用于各种复杂样品中金的测定,结果满意。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.