火焰原子吸收光谱法快速测定黄瓜中的钙和锌

采用悬浮液法和非完全消化法分别对黄瓜样品进行处理,建立了悬浮液法和非完全消化法-火焰原子吸收光谱法快速测定黄瓜中钙和锌的分析方法,以La3+作为钙的释放剂来消除化学干扰。实验表明,在悬浮液中加入适量盐酸可显著提高被测元素的吸光度,试液的物理性质与空白溶液的一致,无背景吸收干扰。测定结果的相对标准偏差小于0.9%,测定结果与灰化法一致,相对误差小于±0.7%。说明,采用火焰原子吸收光谱法,以悬浮液法或非完全消化法取代灰化法来处理黄瓜样品是可行的。     

悬浮液进样-火焰原子吸收光谱法测定芦荟中钙、铁

用悬浮液技术处理芦荟样品,建立了悬浮液进样-火焰原子吸收光谱法快速测定芦荟中钙、铁的分析方法.分别以La3+和盐酸作为钙、铁的释放剂.对琼脂溶液用量、化学干扰、试液与空白溶液特性的一致性、背景吸收干扰及检出限进行了考察.测定结果的相对标准偏差小于3.2%,测定结果与灰化法一致,相对误差小于±0.9%,方法简便.     

非完全消化-火焰原子吸收光谱法测定银杏叶中钙铁锌

将非完全消化法应用于火焰原子吸收光谱法,成功地测定银杏叶中钙、铁、锌。以La3+作为钙的释放剂消除化学干扰。试验表明,试液的物理性质与其空白溶液的一致、无背景吸收干扰。对检出限及特征浓度进行考察。测定结果的相对标准偏差小于1.3%,测定结果与灰化法一致,相对误差小于±0.4%。可见,在火焰原子吸收光谱法中,以非完全消化法取代灰化法处理银杏叶样品是可行的。     

火焰原子吸收光谱法测定茄子中钙镁

本文建立悬浮液技术及非完全消化 -火焰原子吸收光谱法快速测定茄子中钙、镁的分析方法。试验表明 ,在悬浮液中加入适量盐酸可显著提高钙、镁的吸光度。对盐酸溶液用量、化学干扰、背景吸收干扰、试液与空白溶液物理性质的一致性进行考察。测定结果的RSD小于 1.1% ,测定结果与灰化法一致 ,相对误差小于± 1.0 %。     

悬浮液进样-原子吸收光谱法测定甘薯及马铃薯中的钙和镁

将甘薯和马铃薯样品洗净,在75～80℃下烘干,粉碎、过筛并准确称取一定量经过筛的样品在琼脂溶液中制成悬浮液,将此悬浮液技术应用于火焰原子吸收发射光谱法中,建立测定甘薯及马铃薯中钙、镁的快速分析方法。RSD小于3.2%,(要求RSD±5%。)。钙、镁的检测质量浓度分别为0.0432mg/mL、0.0251mg/mL。说明,悬浮技术可代替灰化法技术在原子吸收光谱法中测定甘薯及马铃薯中的钙和镁。此方法处理样品简单、数据准确。     

啤酒中金属的测定

本实验利用非完全消化-火焰原子吸收光谱法快速测定啤酒中的锌、钙、镁金属元素含量的分析方法,用标准曲线测定。对非完全消化法样品处理条件、干扰、试液的物理性质与其空白溶液的一致性、检出限及特征浓度进行考察。测定结果相对标准偏差小于2.0%,本方法的测定结果与灰化法一致,相对误差小于±2.9%。     

啤酒中金属的测定

本实验建立了利用非完全消化-火焰原子吸收光谱法快速测定了啤酒中的锌、钙、镁金属元素含量。用标准曲线测定。对非完全消化法样品处理条件、干扰、试液的物理性质与其空白溶液的一致性、检出限及特征浓度进行了考察。测定结果的相对标准偏差小于2.0%,本方法的测定结果与灰化法一致,相对误差小于±2.9%。     

非完全消化-火焰原子吸收光谱法测定指甲中的镁锌

建立了非完全消化-火焰原子吸收光谱法快速测定指甲中镁、锌的分析方法,在低温下用浓硝酸消解样品,可获得均匀、透明的样品溶液.以空白溶液为参比,用工作曲线法测定.对样品处理条件、化学干扰、硝酸的影响、试液与空白溶液粘度一致性、背景吸收干扰及检出限进行了考察.测定结果的相对标准偏差小于2.9%,测定结果为灰化法一致,相对误差小于±20%.方法简便、快速、准确.     

非完全消化-FAAS法测定小食品中的微量元素

以非完全消化法处理样品,用火焰原子吸收法成功地测定了小食品中的一些微量元素。用La3 作为钙的释放剂。对样品处理条件、化学干扰、背景吸收干扰、试液的物理性质与其空白溶液的一致性、检出限及特征浓度进行了考察。测定结果的相对标准偏差小于3.7%,本方法测定结果与灰化法一致,相对误差小于±3.3%。     

悬浮液进样—火焰原子吸收光谱法测量茶叶中的微量铜

将悬浮液进样技术应用于火焰原子吸收光谱法，成功地测定了茶叶中的微量铜。样品经烘干、粉碎、过筛，制备成琼脂悬浮液。用适量琼脂溶液稀释后直接喷入空气－乙炔火焰，以标准加入法定量。该法测定结果与灰化法一致，相对误差小于±３．０％。方法简单，快速，准确。     

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.     

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....     

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.     

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.