钨舟铅镉元素分析仪与石墨炉原子吸收分光光度计测定血铅方法的比较

通过对钨舟铅镉元素分析仪与石墨炉原子吸收分光光度计测定血铅方法的比较,为检测机构选择检测方法提供参考依据。应用两种方法分别对血铅测定进行方法的精密度、检出限、定量下限试验,对76件人血样品进行测定,测定结果进行相关性分析。两种方法测定血铅均有较高的灵敏度、较好的准确性及精密度。两种方法的相对标准偏差（RSD）均小于7%;钨舟原子吸收光谱法的检出限（3×SD）为0.6μg/L,定量限（10×SD）为1.9μg/L;石墨炉原子吸收光谱法的检出限（3×SD）为0.5μg/L,定量限（10×SD）为1.6μg/L。对4种不同浓度水平的标准物质：美国NIST标准物质山羊血955C（955C2、955C3、955C4）和国家标准物质牛血铅（GBW09154）测定,测定值均在标准值范围内,两种方法对76件人血样品血铅检测的结果经t检验无显著性差异。两种测定血铅的方法均符合方法学要求,检验结果呈高度相关,均适用于血铅的测定。     

一种新型离子色谱安培检测器电解池的研制及Br-、I-、SCN-的检测

研制了一种新型离子色谱安培检测器电解池。电解池为三电极体系 ,由工作电极 (Ag电极 )、辅助电极 (Pt电极 )和参比电极 (Ag/AgCl电极 )组成。工作电极采用柱状电极 ,电极均用螺纹接头固定在电解池上。新型电极池具有工作电极表面积大 ,拆卸清洗方便等优点。应用装有新型电解池的离子色谱安培检测器测定了Br-、I-、SCN-,检测限分别为 16 μmol/L、8μmol/L和 2 0 μmol/L。     

"胃袋式"大体积进样装置性能的初步研究

主要研究了“胃袋式”大体积装置的进样量、响应值、重复性、线性和检测灵敏度等性能。研究得出该装置的进样量可以达到50μL，重复性和线性符合农药残留分析要求。使用此装置20μL进样分析西红柿、菠菜和大米中16种农药，与1μL不分流进样相比较，大部分农药的检测灵敏度可以提高2～15倍。     

一种基于钯-镍/硅纳米线的二量程果糖传感器

利用化学沉积法和恒电流沉积法制备了钯-镍/硅纳米线(Pd-Ni/SiNWs)。以钯-镍/硅纳米线作为工作电极,铂电极为对电极,银-氯化银电极为参比电极,从而构建了一种二量程的无酶电化学果糖传感器。以0.1 mol/L KOH为背景溶液,分别采用循环伏安法(CV)和计时电流法(CA)进行果糖的定量检测。循环伏安法得出果糖检测量程为5~50 mmol/L,灵敏度为0.061 6 mA/(cm~2·mmol/L);计时电流法检测果糖量程为0~7 mmol/L,灵敏度为31.185 2μA/(cm~2·mmol/L),检测限为7.6μmol/L。该种电化学无酶传感器可以实现果糖的快速准确检测。     

儿童全血中铅的石墨炉原子吸收法分析

儿童血铅含量的测定是监测铅对儿童危害的重要手段.铅能引起几乎所有器官系统的功能紊乱,尤其是血液和神经系统.血液中95%的铅在红细胞中,血铅的生物半衰期为2周.研究表明,血铅是当前最可行、最能灵敏反映铅对人体健康危害的指标.而儿童是铅危害的敏感人群,在同样环境条件下,儿童血铅含量往往是成人的1-1.5倍,但儿童的耐受性却远远低于成人.因此为了保护婴幼儿的健康发育和生长,对人群进行定期的血铅检测是极为重要的,也往往用于临床治疗铅中毒(排铅)的观测指标.本文对使用原子吸收仪石墨炉法测定血铅的各项参数及样品处理给予全面介绍.     

同位素稀释多接收电感耦合等离子体质谱法测定血铅

采用同位素稀释多接收电感耦合等离子体质谱（ID-MC-ICP-MS）法测定血铅。运用同位素稀释法测得整个实验的流程空白Pb的浓度平均值为5.6 ng。对SRM 955b level 1和SRM 955b level 3标准血样进行分析,测得血样浓度分别为40.2、207.8 μg•L^-1,测定值落在血样参考值范围之内,证明该方法有效、可靠。利用建立的血铅分析方法,参加了络合型血铅标准物质的定值,得到3种血铅标准样中铅的浓度分别为（102.7±5.5）、（181.7±4.0）、（304.1±3.9） μg•L^-1。     

便携式重金属仪测定水中砷的方法研究

以预镀金膜的玻碳电极为工作电极,采用阳极溶出伏安法实现了水中三价砷及总砷的测定。研制了镀金液、测砷电解液及还原剂,研究了镀金膜条件及富集电位、扫描结束电位、清洗电位等对重复性的影响,改进了参比电极。在最优实验条件下,三价砷在0.10V~0.12V之间产生灵敏的溶出峰,检测限为0.5μg/L,精密度达3%。     

纳米材料沉积的PF电极抗染性与超声清洗研究

电极的防护与抗污染技术是在线水质检测仪器与系统的关键技术之一。目前我国生产的污水在线检测仪由于电极污染及由此引起的稳定性、可靠性问题，已严重影响了我国自主知识产权的污水在线检测仪与系统的开发和竞争力，大量需要的污水在线检测仪还主要依赖进口。探寻和解决电极污染机理与抗污染问题是掌握自主知识产权的污水在线检测系统的关键。本项目在现有工作的基础上，利用已开发的远程水质检测系统及电极超声波清洗机等仪器设备进行研究与试验，通过电极纳米材料沉积和超声清洗方法以解决污水在线检测电极的污染问题。     

毛细管区带电泳安培检测器测定过氧化物

毛细管区带电泳与阴极安培检测器联用，可广泛用于有机和无机过氧化物的定量测定。采用金微电极于-600mv(VS.Ag/AgCl)进行柱端检测，由于电渗流有效消除了工作电极上氧，故检测池和样品无需脱气。进行约1nl，可检测低至10μmol/L的过氧化氢、过氧硫酸盐、过氧链烷酸以及亚油酸过氧化物。往电解质中加入β-环糊精可分离不饱和脂肪酸过氧化物的同分异构体。     

痕量钠离子流动注射离子选择电极分析仪的前期研究

开发了一种用于纯水中痕量Na^ 的流动注射离子选择性电极快速测定法。以高纯水作载流，实现了在线自动微量碱化、电极自动清洗和完全密封状态下的测定，彻底解决了常规法测量时样品被空气钠离子污染，不能进行准确测定的问题。测定范围为2．0～100μg/L，检出限为1．0μg/L，进样频率为50样／h，一次用样量仅为0．3mL，已成功地用于电厂炉水、蒸汽中痕量Na^ 的测定。碱化剂用量仅为常规工业钠表的1／50左右．在此基础上开发的新型在线钠表可大大降低耗碱量，提高经济指标．保护环境。     

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.