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。     

氢化物发生原子荧光光谱法测定水样中痕量锑(Ⅲ)和锑(Ⅴ)

文章提出用酒石酸作酸介质 ,氢化物发生原子荧光光谱法 ( HG- AFS)测定水样中痕量 Sb( Ⅲ )和 Sb( Ⅴ )的分析方法。试验了 Sb(Ⅴ )的最佳还原条件。Sb( Ⅲ )和总 Sb检出限分别为 0 .1 2μg/L和 0 .0 8μg/L,相对标准偏差 ( RSD,n=1 1 )分别为 5 .2 %和 6.4% ,加标回收率在 84.8%～ 1 0 1 .4%之间     

HPLC测定香砂枳术丸中白术内酯Ⅰ和Ⅲ的含量

目的 :建立同时测定香砂枳术丸中白术内酯Ⅰ和Ⅲ含量方法。方法 :采用DIONEX C18色谱柱(250mm×4.6mm,5μm),流动相:乙腈:甲醇:0.1%磷酸溶液(11:46:43),检测波长为222nm,柱温:35℃,流速为1.0mL·min-1。结果:白术内酯Ⅰ和Ⅲ分别在0.1².0μg·mL-1(γ=0.9997)和0.22.0μg·mL-1(γ=0.9997)和0.2⁴.0μg·mL-1(γ=0.9998)浓度范围内线性关系良好,平均加样回收率分别为98.7%,98.0%;RSD分别为0.68%、1.15%。结论 :本方法简便,准确,重复性好,可用于该制剂的质量控制。     

HPLC法同时测定阿司匹林咀嚼片中阿司匹林和水杨酸的含量

目的用高效液相色谱法同时测定阿司匹林咀嚼片中阿司匹林和水杨酸的含量.方法采用VP-ODS色谱柱;以甲醇-醋酸-水(45∶1∶54)为流动相;流速1ml/min,检测波长为275nm.结果阿司匹林线性范围0.54～10.85μg(γ=0.99996),平均回收率为98.3%,RSD为0.76%(n=5);水杨酸线性范围2.65～31.77μg/ml(γ=1.00000),平均回收率为100.2%,RSD为0.53%(n=5).结论此方法简便、快速、准确,值得推广应用.     

锰(Ⅱ)-1-(2-吡啶基偶氮)-2-萘酚-混合微乳液显色体系的研究与应用

文章研究了以阳离子型微乳液 CTMAB/ n- C4H9OH/ n- C7H16/ H2 O与非离子型表面活性剂乳化剂 - OP的混合微乳液为介质 ,Mn( )与 1 - ( 2 -吡啶偶氮 ) - 2 -萘酚( PAN)的显色反应 ,在 p H值 9.0～ 1 0 .0范围内 ,配合物的最大吸收波长为 5 64nm,回归方程 :A=0 .0 30 2 c- 0 .0 0 1 7( c/ μg· 2 5 ml-1) ,相关系数 r=0 .9999,表观摩尔吸光系数为 4.2 9× 1 0 4L·mol-1·cm-1,Mn( )浓度在 0 .39μg· 2 5 ml-1～ 2 0 μg· 2 5 ml-1范围内服从比尔定律 ,检出限 0 .39μg· 2 5 ml-1,相对标准偏差 ( RSD% )在 0 .0 1 4%～ 0 .91 %之间 ,加标回收率在92 .72 %～ 1 1 0 .75 %之间。本法用于铝合金中微量锰的测定 ,结果令人满意。     

溴化衍生-液液萃取-气相色谱法检测水中的丙烯酰胺

在pH=1～2条件下,水中的丙烯酰胺与新生溴发生加成反应,生成衍生产物2,3-二溴丙烯酰胺,经乙酸乙酯液液萃取后,通过气相色谱-一微电子捕获检测器检测.结果表明,2,3-二溴丙烯酰胺的线性范围为1～13μg/L,r=0.9936,检出限为1μg/L.单体丙烯酰胺在0.1、0.2、0.4、0.5、1μg/L水平下,回收率为61.6%～112%,RSD为5%～9.49%.     

液相色谱-原子荧光法测定化妆品中硫柳汞和苯基汞

建立了液相色谱(HPLC)-原子荧光(AFS)联用法测定化妆品中硫柳汞和苯基汞含量的方法。样品经超声提取后高速离心,经0.45μm滤膜过滤,HPLC-AFS测定,保留时间定性,外标法定量。该方法硫柳汞在2.5μg/L～50μg/L、苯基汞在62.5μg/L～1250μg/L呈良好的线性关系(R2≥0.998)。在0.075μg、0.15μg、0.225μg 3个添加浓度水平下硫柳汞的回收率为84.7%～101.7%,在1.875μg、3.750μg、5.625μg 3个添加浓度水平下硫柳汞的回收率为84.1%～103.9%,定性重复性为0.30%～0.33%,定量重复性为4.22%～4.96%,硫柳汞的检出限为0.060μg/L,苯基汞的检出限为0.23μg/L(S/N=3)。该方法成本低,分析速度快,精密度好,检出限低,适用于化妆品中硫柳汞和苯基汞的检测。     

超高效液相色谱-串联质谱测定土壤中磺胺类药物残留

建立了固相萃取-超高效液相色谱三重四级杆质谱联用法测定土壤中痕量的18种磺胺类残留的方法,土样提取液经过固相萃取富集净化后由液相色谱分离、三重四级杆质谱检测。该方法在10 min内完成对18种目标化合物的分析。磺胺类线性范围为1¹00μg/L,相关系数均大于0.995,6次空白加标重复测定的相对标准偏差(n=6)为1.8%100μg/L,相关系数均大于0.995,6次空白加标重复测定的相对标准偏差(n=6)为1.8%¹5.9%。l8种目标化合物的方法检出限在0.0515.9%。l8种目标化合物的方法检出限在0.05⁰.48μg/kg之间,实际样品的加标回收率为64.9%0.48μg/kg之间,实际样品的加标回收率为64.9%¹04%。该方法操作简便,重现性好,可用于土壤中磺胺类的检测。     

HPLC法同时测定复方利血平片中硫酸双肼屈嗪等5种成分

目的:建立同时测定复方利血平片中硫酸双肼屈嗪、氢氯噻嗪、维生素B1、维生素B6和泛酸钙5个成分的高效液相色谱法.方法:采用Inertsil oDS-SP (4.6mmx250mm,5μm)色谱柱,以缓冲液(0.11％己烷磺酸钠,0.02％庚烷磺酸钠混合溶液,每1000mL加0.2mL三乙胺,用5％磷酸溶液调节pH值至3.5)-乙腈-甲醇(70∶10∶20)为流动相,检测波长为210nm.结果:硫酸双肼屈嗪、氢氮噻嗪、维生素B1、维生素B6、泛酸钙的浓度分别在8.4～ 126.Sμg/mL(r=0.9997)、6.3～94.3 μ g/mL(r=0.9997)、2.0～29.5μg/mL(r=0.9997)、2.0～～ 29.Sμg/mL(r=0.9996)、2.2～29.8μg/mL(r=0.9996)范围内线性良好.平均回收率为96.5％～99.0％,RSD为0.6％～1.3％(n=15).结论:该方法可用于复方利血平片中硫酸双肼屈嗪、氢氮噻嗪、维生素B1、维生素B6、泛酸钙的测定.     

离子色谱法测定饮用水中痕量溴酸盐

本文建立了一种无需样品前处理,直接进样,电导检测饮用水中痕量溴酸盐的离子色谱新方法.分析柱为Dionex IonPac AS19阴离子交换拄,EG40在线产生KOH淋洗液,等浓度泵作梯度淋洗.该方法对溴酸盐的栓出限为0.3.μg/L,在1-100μg/L范围内具有良好的线性(r=0.9999).将该方法用于桐乡市自来水和市售桶装水样品中痕量溴酸盐的检测,实际样品的加标回收率在94.5%-108.4%之间,1μg/L溴酸盐连续进样10次相对标准偏差(RSD)为6.25%.     

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...     

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.     

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.     

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.     

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....     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.