HPLC法测定饮用水中的甲醛残留

本实验在加酸加热的条件下,水样中的甲醛与氨比西林直接反应,用乙醚提取反应产物,用反相高效液相色谱分离荧光检测器检测。甲醛在0．1～2．0μg／ml的浓度范围内线性相关系数达0．999以上,检出限可达0．01μg／ml,相对标准偏差（RSD）为0．65％,加标回收率为95．7％～106．0％。     

高效液相色谱法测定对虾中五种磺胺类药物残留

采用反相高效液相色谱法，同时测定对虾中的五种磺胺类药物残留。用C18柱．紫外(或PDA)检测器，流动相为5mmol／L NaH2PO4溶液．乙腈溶液，磷酸调pH2．8，流速1．0mL／min，枉温35℃，于267nm波长处检测。最低检测限达到2μg／kg，相关系数在0．9997以上。五种药残加标回收率在100μg/kg，50μg/kg，10μg/kg三个水平上分别为81．90％，79．86％，71．80％，RSD＜10％亦符合痕量测定要求。     

高效液相色谱法测定水中微量甲醛的残留

本文利用测定甲醛和氨比西林的衍生产物,建立起一种测定饮用水中微量甲醛残留的高效液相色谱法。在加酸加热的条件卞,水样中的甲醛与氨比西林直接反应,反应产物用乙醚提取出来,并用反相高效液相色谱分离荧光检测器检测。甲醛在0.1-2.0μL/ml的浓度范围内线性相关系数达0．999以上,检出限可达0.01μg／ml,相对标准偏差（RSD）为0.69％,加标回收率为95.8％-108.0％。     

高效液相色谱-串联质谱联用(Finnigan TSQ Quantum)测定鳗鱼中孔雀石绿、隐性孔雀石绿残留量

利用高效液相色谱串联质谱（LC／MS／MS）方法快速．准确的同时测定鳗鱼中孔雀石绿．隐性孔雀石绿残留量。鳗鱼样品经乙腈．乙酸铵缓冲溶液提取，液相色谱分配到二氮甲烷层，MCX阳离子固相革取小柱净化，浓缩定容。以甲醇和甲酸缓冲溶液为流动相，经C18柱分离后，并用串联质谱在电喷雾（ESI＋）-选择反应监测离子（SRM）的模式下，氘代隐性孔雀石绿为内标，进行质谱定性和定量。该方法无需采用传统PbO2氧化柱，检测限（LOD）为0．2μg／Kg，定量下限为0．5μg／Kg，完全可以达到出口欧盟和日本残留限量要求。     

高效液相色谱-蒸发光散射法测定马鞭草中齐墩果酸与熊果酸的含量

建立了高效液相色谱一蒸发光散射检测法测定马鞭草药材中齐墩果酸和熊果酸含量的方法,色谱柱为PinnacleⅡ C18（250min×4．6mm,5m）,流动相为甲醇-0．2％冰醋酸（体积比82．5：17．5）;淋洗速度1mL／min;柱温35℃;蒸发光散射检测器检测,漂移管温度为85℃;气体流速为2．2L／min。齐墩果酸在0．317～1．585μg范围内（r=0．9997）,熊果酸在0．585～2．925g范围内（r=0．9999）线性关系良好。药材中齐墩果酸和熊果酸的回收率（n=6）分别为100．4％和97．6％,标准偏差分别为1．84％和2．34％。所建方法准确,重现性好,可作为马鞭草药材的质量控制方法。     

超高效液相色谱法测定天然β-胡萝卜素软胶囊中β-胡萝卜素

建立了超高效液相色谱测定天然β-胡萝卜素软胶囊中β-胡萝卜素的方法。样品用石油醚溶解提取,通过中性氧化铝柱,用丙酮＋石油醚（5＋95）洗脱、净化,用ACQUITYUPLCBEHC18（2．1×50mm,1．7um）色谱柱分离,以甲醇为流动相,流速为0．3mL／min,柱温为55℃,用二极管阵列检测器在450nm检测β-胡萝卜素,用外标法定量。结果表明,β-胡萝卜素在0．0—10．0μg／mL范围内有良好的线性关系,相关系数为0．9995,回收率在90％-95％之间。本方法简便快速,结果准确可靠。     

原子荧光光谱法快速检测化妆品中的砷和汞

介绍原子荧光光谱法用于化妆品中砷和汞的快速检测方法，用HN03一H202消化样品，选择了最佳测试条件，砷和汞的线性检测范围分别是0—200μg／L和0-20μg／L，方法检出限分别为0．0213μg／L和0，0032μg／L，样品加标回收率分别在96．4％-100．5％和93．5％-101．0％之间。本法灵敏度高、操作简便、结果准确。     

离子色谱法测定蔬菜、水果中的亚硝酸盐和硝酸盐

建立了用离子色谱法／电导检测器测定蔬菜和水果中亚硝酸盐和硝酸盐的方法。优化了分离条件，以3.5mg／L Na2CO3-1．0mg／L NaHCO3为淋洗液，10μg／mL Cl^-和0．50μg／mL NP2^-能得到良好的分离。相对标准偏差：NO2^-为1．5％，NO3^-为0．61％；回收率：NO2^-为97％～102％，NO3^-为96％～104％。     

高效液相色谱法测定茶叶中噻嗪酮的残留量

建立了用高效液相色谱法测定茶叶中噻嗪酮农药残留量的方法，样品用乙腈提取，弗罗里硅土柱净化，用乙腈-0.1％磷酸水溶液做流动相，紫外检测器245nm检测，外标法定量。添加浓度在0．05～2．0mg／kg时，平均回收率为84．5～95．4％，相对标准偏差〈7．60％，噻嗪酮的最小检出量为0．03mg／kg。该方法的灵敏度、准确度和精密度均符合农药残留测定的技术要求。     

高效液相色谱法测定朝鲜蓟中的天冬酰胺

采用阳离子交换柱分离，荧光检测器检测，pH梯度洗脱，邻苯二甲醛-2巯基乙醇拄后衍生，成功分离、检测了朝鲜鲜蓟中的天冬酰腰。若以天冬酰胺的峰高Y（μV）对进样质量X（μg）进行线性回归，则线性方程为Y=4566X＋1396．r=0．9998；平均回收率（n=3）为973％，方法稳定、灵敏、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.     

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....     

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.     

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.