SPE-UPLC-MS/MS法测定牛奶中β-内酰胺类药物残留

本试验应用固相萃取技术(SPE),结合超高效液相色谱-串联质谱联用仪(UPLC-MS/MS),建立了快速测定生鲜乳中!-内酰胺类药物残留的方法。样品经乙腈提取,Oaiss PRiME HLB固相萃取小柱净化后,以0.1%甲酸乙腈溶液和0.1%水溶液为流动相,Waters C_(18)色谱柱进行分离;多反应监测(MRM)模式,外标法进行定量。方法回收率在70.1%~95.5%之间;相对标准偏差(n=3)范围为1.0%~9.1%;线性范围为0.002~0.100mg/L;检出限为0.1~0.6μg/kg;定量限为0.3~1.8μg/kg。表明该方法专属性强、灵敏度高,适用于生鲜乳中β-内酰胺类药物残留的测定。     

超高效液相色谱-串联质谱法测定豆芽中7种药物残留

建立了甲醇超声提取,分散固相萃取净化技术（QuEChERS）净化,超高效液相色谱-串联三重四极杆质谱（UPLC-MS/MS）检测豆芽中7种药物（咪鲜胺、头孢氨苄、诺氟沙星、6-苄氨基嘌呤、赤霉酸、2,4-二氯苯氧乙酸和4-氯苯氧乙酸）残留的方法。样品用含0.1%甲酸的甲醇溶液超声提取,QuEChERS（PSA+C18）净化,在UPLC-MS/MS的电喷雾正、负离子分段扫描和多反应监测（MRM）模式下检测,以保留时间和特征离子对定性,外标法定量。结果表明,7种待测物在0.4~100 μg/L范围内线性关系良好;方法定量限（S/N=10）为2.0~5.0 μg/kg;添加水平为2.0~50 μg/kg时,平均回收率在80.7%~115%之间;相对标准偏差（RSD,n=6）为2.6%~13.5%。本方法具有前处理简单、结果准确、回收率高等特点,可以应用于豆芽中7种药物残留的日常监测。     

分散型固相萃取-气相色谱串联质谱法测定食品中8种芳氧苯氧丙酸酯类除草剂的残留量

建立了大豆、绿茶、大米、胡萝卜、菠菜、豌豆、大蒜、草莓、蜂蜜、猪肉、鱼肉、鸡蛋等12种食品中8种芳氧苯氧丙酸酯类除草剂残留量的分散型固相萃取-气相色谱串联质谱(DSPE-GC-MS/MS)分析方法。样品由含1%冰醋酸的正己烷的饱和乙腈溶液提取,分散型固相萃取法净化,采用气相色谱-串联质谱分时段反应离子监测技术进行测定,外标法定量。所有农药在10~1 000μg.L-1范围内线性良好;方法定量限(LOQ)均低于10μg.kg-1;在10、20、40μg.kg-1三个添加水平下,大豆等12种代表性基质中所有农药的平均回收率均处于70%~120%之间,RSD≤13%;该方法选择性较好,不仅能够用于多种食品基质的残留检测,而且还能较好地解决本底成分相当复杂的大蒜基质极易出现的干扰问题。     

超高效液相色谱-质谱/质谱法测定草莓中丁氟螨酯残留量

建立了超高效液相色谱-质谱/质谱法(UPLC-MS/MS)检测草莓中丁氟螨酯残留分析方法。样品采用乙腈提取,使用QuEChERS方法净化,UPLC-MS/MS测定,外标法定量。结果表明,在2～100μg/L浓度范围内,线性R2=0.9999,回收率在82%～102%,相对标准偏差10%,方法的检出限为1μg/kg,符合检测方法确认的技术要求,可以用于草莓中丁氟螨酯的检测。     

基质分散固相萃取-UPLC-MS/MS测定烟草中马来酰肼残留量

建立了烟草中马来酰肼残留检测的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。烟叶样品经盐酸溶液回流萃取,氘代同位素内标定量,PSA净化和UPLC-MS/MS分析测定,分析时间仅需8 min。结果表明,马来酰肼的工作曲线在50 ng/mL~5000 ng/mL之间线性关系良好(R 2>0.99),各种烟叶基质中马来酰肼的检出限(LOD,以S/N=3计)范围为0.624~987 ng/mL;在2.5,15和100 ng/g加标水平下,加标回收率在105.9%~111.8%之间,RSD范围为3.3%~9.1%。本方法具有快速,简便,准确性好的特点,适用于烟草中马来酰肼残留量的检测。     

微波辅助提取-固相萃取净化-气相色谱三重四极杆质谱联用测定水产品中17种多氯联苯（PCBs）

为了给食品中持久性有机污染物残留的定性与定量检测提供技术支持,建立了一种微波辅助提取-固相萃取净化-气相色谱三重四极杆质谱联用测定水产品中17种多氯联苯（PCBs）的检测方法。样品用V（正己烷）∶V（丙酮）=1∶1的混合溶剂于微波提取,经佛罗里硅土固相萃取柱净化,以氦气为载气,HP5-MS色谱柱分离,MS/MS多反应监测扫描模式（MRM）检测。方法线性相关系数r＞0.999,仪器定量限为1.0~3.0 μg/kg。在5.0、10.0、20.0 μg/kg 3种浓度添加水平,其平均回收率为83.1%~100.8%,相对标准偏差(RSD)为4.36%~9.38%。该方法已成功应用于复杂基质样品中17种PCBs的检测。     

GPC-LC-MS/MS法测定大米中8种农药残留

建立了凝胶渗透色谱(GPC)-液相色谱串联质谱(LC-MS/MS)法测定大米中8种农药残留的分析方法。样品用乙腈超声提取,提取液经过凝胶渗透色谱除去大分子杂质后,供LC-MS/MS分析;添加浓度为0.2μg时,回收率为71.3%~111.1%,相对标准偏差为3.64%~12.76%,方法具有自动化程度高、净化效果好、精密度好,分析快速等优点,适用于大米中多农药残留的日常检测工作。     

气相色谱-离子阱-多级质谱法检测鱼体组织中19种有机氯农药

建立了鱼体组织中19种有机氯农药残留分析的气相色谱-离子阱-多级质谱(GC-IT-MS/MS)方法。试样用V(正己烷)∶V(丙酮)=1∶1溶液提取,凝胶渗透色谱和固相萃取联合净化,浓缩、定容后,上机分析。结果表明,采用EI电离模式,选择不同的监测特征离子,GC-IT-MS/MS法能灵敏测定加标试样中全部目标化合物。添加浓度为5.0μg.kg-1和10μg.kg-1时的加标回收率在76.2%～106%之间,相对标准偏差在4.8%～11%范围内;检测限(S/N=3)和定量限(S/N=10)分别为0.03～1.42μg.kg-1和0.1～4.27μg.kg-1。     

UPLC-MS/MS同时测定水产品中4种丁香酚类麻醉剂残留量

建立了固相萃取-超高效液相色谱-串联质谱（UPLC-MS/MS）分析法同时测定水产品中4种丁香酚类麻醉剂残留量。样品经正己烷提取,HLB固相小柱萃取净化,多反应监测（MRM）正、负离子模式同时测定,以外标法定量。结果表明,丁香酚、异丁香酚的定量限均为2.5 μg/kg,甲基丁香酚和甲基异丁香酚的定量限均为1.0 μg/kg。在1～200 μg/L浓度范围内,峰面积与浓度的线性关系良好（R²>0.996）,方法的加标回收率在77.6%～111.4%之间,相对标准偏差为2.7%～9.1%。该方法操作简单,可在一定程度上实现丁香酚类麻醉剂多残留的快速检测。     

Oasis HLB净化和超高效液相色谱-电喷雾串联质谱检测冻虾中阿维菌素类药物残留

建立采用超高效液相色谱-电喷雾电离串联四极杆质谱（UPLC-MS/MS）同时检测冻虾中阿维菌素、伊维菌素、多拉菌素、爱普利诺菌素残留的方法。试样经乙腈提取、浓缩,经HLB固相萃取小柱净化,超高效液相色谱-电喷雾串联质谱法测定。对流动相、监测离子、校正曲线等进行优化和探讨。实验结果表明,4种分析物在5-100ng/mL范围内线性关系良好,相关系数均大于0.999。4种分析物在2μg/kg,10μg/kg,20μg/kg加标水平的平均回收率为75.1%-92.5%,相对标准偏差为6.78%-9.89%。四种阿维菌素类药物的检出限均可达到0.5μg/kg。     

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...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

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.     

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....