ICP-MS同时测定玛咖中16种稀土元素的研究

建立一种快速消解并同时测定玛咖中稀土元素的方法。采用微波消解样品,选择In作内标,电感耦合等离子体质谱法(ICP-MS)测定玛咖中稀土元素。对于所测的元素,校准曲线的相关系数>0.9990,回收率范围91.0%~111.0%,相对标准偏差0.4%~3.7%。该方法简便、快速、准确,灵敏度高,可用于玛咖中稀土元素的测定。     

茶叶中锗、硒的电感耦合等离子体质谱法分析

采用微波消解,电感耦合等离子体质谱(ICP-MS)法测定茶叶中锗、硒元素。对样品前处理方法进行了研究,从消解体系、酸用量、消解程序等方面对微波消解条件进行了优化。在优化实验条件下, 方法的检出限为1.7~28.2 ng•L-1, 相对标准偏差为3.1%~10.0%, 加标回收率为80.8%～95.9%。该方法具有操作简便,快速,灵敏度高,准确度好和同时测定两种元素等优点。     

应用ICP-MS测定国际比对果汁样品中铅、镉和锡的含量

建立了微波消解、电感耦合等离子体质谱法（ICP-MS）同时测定国际比对果汁样品中铅、镉和锡的方法。应用微波消解进行样品前处理,采用在线内标校正基体干扰,采用干扰方程抑制质谱干扰,使用工作曲线计算出样品中铅、镉和锡元素的含量。测定结果表明,铅、镉和锡元素的检出限分别为0.021、0.016和0.052μg/L,相对标准偏差（RSD〈5%）,加标回收率介于90%～105%,用该方法测定FAPAS国际比对果汁样品,反馈的统计结果显示铅、镉和锡元素的Z值分别为-0.4、0.1和-0.2,结果均为满意。该方法快速、简单、精确,适于果汁中铅、镉和锡的测定。     

ICP-MS同时测定醋酸酯淀粉中4种元素

建立了微波消解-电感耦合等离子体质谱仪(ICP-MS)同时测定醋酸酯淀粉中4种微量元素含量的方法,用国家标准方法石墨炉原子吸收光谱法(AAS)对方法准确性进行了验证。通过比较3种前处理方法、两种仪器测定醋酸酯淀粉中4种元素的含量,最后选用耗时短、回收率高、操作稳定的能同时测定4种元素的微波消解法对醋酸酯淀粉样品进行消解,利用ICP-MS法测定铬、镍、镉、铅4种元素含量。该方法线性范围广,线性相关系数r﹥0.9997,回收率92.0%~100.3%,RSD﹤3.8%。具有操作快速、准确、可靠等优点,在醋酸酯淀粉实际分析应用中,取得了令人满意的结果。检测结果表明,醋酸酯淀粉中所测元素均小于0.2mg/kg,符合国家标准的限量要求。     

ICP-MS法测定1β-甲基碳靑霉烯双环母核原料药残留

建立了电感耦合等离子体质谱法(ICP-MS)测定原料药1定原甲基碳靑霉烯双环母核中催化剂铑残留的方法。采用硝酸微波消解处理样品,通过配制铑系列标准溶液,验证标准曲线方程和相关系数,确定该方法的相关系数均为0.999以上。利用该检测方法,铑回收率较好,3个加标浓度水平下回收率在90.88%～100.40%之间。方法检出限可达到1.70μg/kg,精密度实验RSD在4%以内。提出的ICP-MS测试法快速、灵敏、准确,适用于1试法甲基碳靑霉烯双环母核原料药中催化剂铑残留的测定。     

湿法消化ICP-MS法与微波消解ICP-MS法测定圆白菜标准物质中铅、镉、砷的比较

建立了电感耦合等离子体质谱法（ICP-MS）测定圆白菜标准物质中铅、镉、砷含量的分析方法。采用湿法消化和微波消解两种前处理方法,消解样品后对其进行了ICP-MS分析,在线内标溶液校正仪器的信号漂移,通过比较两种前处理方法对元素铅、镉、砷的测定结果分析显示,两种前处理方式测定值均在参考值范围内,无显著性差异,且相对标准偏差在0.41%～4.0%之间,测定结果准确可靠。湿法消化和微波消解两种前处理方式均可做为ICP-MS的前处理方法。     

冷凝回流三酸体系消解—ICP-MS法测定高纯石墨中的痕量杂质元素

建立冷凝回流混合酸消解,ICP-MS法测定高纯石墨中35种痕量元素的方法。采用1 mL HNO₃,1 mLHClO₄和3 mL H₂SO₄于220 ℃消解0.2 g 样品,以Sc、Rh、Cs、Re作内标,ICP-MS法测定各元素的方法检出限为0.000 6~0.1 μg•L^-1,加标回收率达82%~110%,相对标准偏差（RSD,n=10）为0.58%～5.8%。该方法适用于高纯石墨中痕量杂质含量的测定。     

微波消解ICP-MS法测定某肺癌高发区居民饮食中28种元素

采用真空冷冻干燥和硝酸 过氧化氢体系微波消解处理饮食样品，ICP-MS法测定样品中28种元素的含量。在优化仪器工作参数后，以铑(Rh)和铼(Re)双内标对基体影响和信号漂移进行校正，并采用4种国家标准物质验证该方法的准确度和精密度。结果表明，28种元素检出限为0.01~0.40 μg/L，加标回收率为82%~114%，国家标准物质测定值与标准值或参考值一致，精密度(RSD)为0.4%~16.9%。用该方法测定60份肺癌高发区居民饮食样品中28种元素含量，结果可为研究微量元素与肺癌的关系和指导合理膳食提供参考。     

洋葱中重金属分布的ICP-MS分析

采用电感耦合等离子体质谱法测定洋葱中重金属的分布,用硝酸-过氧化氢作消解液, 微波消解法处理样品,ICP-MS 法测定洋葱皮和肉中砷、铅、汞3种重金属元素的含量。测定结果的相对标准偏差RSD< 5.1%, 加标回收率为91.1%～104.9%, 检出限为0.007 2～0.087 ng•g^-1。该方法具有操作简便,快速,灵敏度高,准确度好和多种元素同时测定等优点。     

电感耦合等离子体质谱法测定中药材中铜、砷、镉、铅、汞的含量

目的:建立电感耦合等离子体质谱法(ICP-MS),测定中药材中5种重金属铜、砷、镉、汞、铅的含量。方法:微波消解法处理样品,以锗(Ge)、铟(In)、铋(Bi)为混合内标,采用ICP-MS测定上述元素。结果:各元素标准曲线的线性良好,相关系数均大于0.9980,检出限为0.00055mg/kg^0.013 mg/kg,回收率在97.6%~106.2%之间,RSD<10%。结论:实验结果表明,该方法简便、快速、准确,适合中药材样品中铜、砷、镉、汞、铅的检测。     

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...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

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。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.