固相萃取-高效液相色谱法测定水中甲萘威

采用固相萃取，高效液相色谱法对水中甲萘威进行检测，通过实验研究，该法对水中甲萘威的最低检测限为0．001mg/L，相对标准偏差（RSD，n=5）≤2．5％，加标回收率为98．0％～98．5％，固相萃取效果优于液液萃取。该方法适合于地表水及饮用水中甲萘威的检测。     

固相萃取-气质联用法同时测定海水中六六六、滴滴涕、狄氏剂

建立了固相萃取-气质谱联用法（SPE—GC／MS）同时测定海水中六六六、滴滴涕、狄氏剂的方法。该方法采用OasisHLB固相萃取小柱萃取富集水样,以二氯甲烷洗脱,加入菲-d10作为内标,利用GC／MS进行定性定量分析。该方法的线性响应良好,干扰小,检出限为0．16～1．0ng／L（按采样2L海水计）,添加回收率为86．6％～122％,相对标准偏差为1．2％～5．1％。该方法可以同时满足海水中六六六、滴滴涕、狄氏剂的测定。采用该方法从广西近岸海域八个监测点采集海水样品进行SPE—GC／MS法检测,结果均未检出有机氯农药。     

固相萃取/高效液相色谱法测定水中6种氨基甲酸酯农药

采用C-18小柱萃取、高效液相色谱法测定水样中的6种氨基甲酸酯农药，检出限为0．005-0．0005mg／L。测定相对标准偏差小于6．8％，加标回收率在70％-90％之前。     

固相萃取-离子色谱法测定乳与乳制品中可致癌物硝酸盐的研究

研究了采用固相萃取-离子色谱法测定乳与乳制品中可致癌物硝酸盐.将制备好的样品加入适量乙酸沉淀蛋白,离心,取上清液以4mL/min的流速通过DIONEX OnGuard Ⅱ RP固相萃取柱去除脂肪等疏水性化合物后,直接进样测定.用30mM的KOH溶液等度淋洗,流速为1.0mL/min,采用AS11-HC型阴离子色谱柱进行分析.在此检测条件下,硝酸盐有很好的线性（r=0.9999）,回收率为85.5%～108%.实验结果表明,该方法简便、快速,且检测结果准确.     

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％。     

微波辅助萃取-气相色谱／质谱-选择离子监测法同时测定皮革制品中21种邻苯二甲酸酯类化合物

建立了气相色谱／质谱-选择离子监测方法,对皮革制品中21种邻苯二甲酸酯类化合物进行了同时测定。该方法以乙腈为萃取溶剂,对皮革制品进行微波辅助萃取,萃取物经中性氧化铝固相萃取柱净化处理后进行气相色谱／质谱-选择离子监测法测定。该方法快速简便,定性定量准确,检出限低,DIDP和DINP的检出限分别为2．0、1．0mg／kg,其余各组分的检出限均低于0．4mg／kg。该方法的精密度试验的RSD均小于9％,加标平均回收率为88．75～97．86％。采用该方法对47个市售皮革制品进行测定,结果在2个样品中检出多种邻苯二甲酸酯类化合物。     

饮用水和地下水中环氧氯丙烷的快速测定——气相色谱／质谱法

建立了液-液萃取-气相色谱／质谱法测定饮用水和地下水中环氧氮丙烷的方法。用二氮甲烷萃取水样中环氧氯丙烷浓缩定容后,经色谱分离质谱采用选择离子（SIM）模式进行检测。水样中环氧氮丙烷得最低检测限可达到0．08μg／L。浓度在0．02μg／mL-0．52μg／mL时标准曲线的线性相关系数产0．9991。在三个添加水平的回收率测定（n=5）,其回收率在78％～86．76％之间。相对标准偏差为6．4％-12．2％。     

气相色谱法-氮磷检测器检测污水处理厂进出水中有机磷农药残留

采用固相萃取全自动工作仪和Triazine前处理柱对污水处理厂的进、出水样进行前处理,用气相色谱法一氮磷检测器检测污水中测乐果、甲基对硫磷、马拉硫磷和对硫磷4种有机磷农药残留。研究了在不同铷珠电流值条件下氮磷检测器对4种有机磷农药的响应值。本法对乐果、甲基对硫磷和马拉硫磷的检出限为0．03ng／μL,对硫磷为0．005ng／μL,线性范围均为3-500ng／mL,加标回收率为79％～115％。试验结果证明,可以采用较大直径的毛细管柱进行污水中有机磷农药的测定。     

高效液相色谱法测定猪肝组织中土霉素、四环素、金霉素残留量

建立了高效液相色谱法测定猪肝组织中四环素族抗生素留量的方法。通过对样品前处理方法进行优化,用固相萃取-高效液相色谱法同时测定了猪肝组织中土霉素、四环素、金霉素3种四环素族抗生素的残留量。该法对土霉素、四环素、金霉素的检出限分别为13、15、40μg／kg,相对标准偏差为3．02％～5．93％,平均回收率为83％～90％。     

高效液相色谱外标法测定杀菌防腐剂BIT

建立了高效液相色谱法测定杀菌防腐剂BIT（1,2-苯并异噻唑啉-3-酮）含量的方法。采用Kromasil C18色谱柱（250×4．6mm）,流动相为甲醇-含0．5mol／L磷酸二氢钾的水溶液（体积比为1：1）;流速为0．6mL／min;紫外检测波长为225nm;外标法定量。样品的平均加标回收率为99．5％-100．10％,相对标准偏差（RSD）为0．20％—0．86％,检出限为0．01mg／kg（S／N=-3）。     

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.