改性纳米TiO2分离富集-ICP—AES法测定环境样品中痕量铬、铜、镍和铅

提出了改性纳米TiO2分离富集电感耦合等离子体原子发射光谱（ICP—AES）法测定环境样品中痕量Cr3＋、Cu2＋、Ni2＋和Pb2＋的新方法。系统地研究了溶液pH值、吸附剂用量、洗脱条件、流速、静态吸附容量和干扰离子等因素对分析物分离富集的影响。结果表明,在pH4．0,Cr3＋、Cu2＋、Ni2＋和Pb2＋可被改性纳米TiO2定量富集,吸附的金属离子可用2．0mL2．5mol·L^-1 HCl溶液完全洗脱。在优化的实验条件下,吸附剂对Cr3＋、Cu2＋、Ni2＋和Pb2＋的吸附容量分别为18．1,17．6,23．2和26．8mg·g-1。本法对Cr3＋、Cu2＋、Ni2＋和Pb2＋的检出限（30）分别为：0．25,0．43,0．62,0．39ng·mL-1,相对标准偏差（RSD）分别为2．3％,3．1％,2．5％,3．8％（n=11）。方法用于环境样品中痕量Cr3＋、Cu2＋、Ni2＋和Pb2＋的测定,结果令人满意。     

FAAS法对人体血样中铅、锌和铁的测定与研究

本文使用了火争原子吸收光谱法测定人体血样中铅、锌、铁的方法。确立了最佳样品处理方法和仪器的工作条件。在拟定的实验条件下，测定铅的特征浓度为0．010ug/ml/1%吸收；测定锌的特征浓度为0．002ug/ml 1/%吸收；测定铁的特征浓度为0．014ug/ml／1％吸收。回收率分别为铅99．2％－101．5％，锌92．5％－98．6％，铁98．8％－103．4％。     

蒸气发生-原子荧光光谱法测定绿色食品生产基地中的砷、锑和汞

研究了VG—AFS法测定土壤样品中微量As、Sb和Hg在两种不同方式王水消解方法时对分析结果的影响，以及优化了各种分析条件，拟定了分析方法。本法经国家一级土壤标样测定验证，结果与标准值吻合。测得砷、锑和汞的方法检出限分别为0．028ug/g、0．028ug／g和0．009ug/g；相对标准偏差(n=6)分别为1．9％、5．5％和5．0％。     

电感耦合等离子体质谱法测定电子电气产品中Cr、Cd、Hg、Pb和Br

利用ICP-MS测定电子电气产品中镉、铬、铅、汞和溴。用高压微波消解技术处理样品，在消除Hg和Br的高记忆效应后，2，5％的硝酸介质下，上述元素的检测限（Cr，Cd，Hg，Pb）和Br分别为0．08 μg/L、6．0μg／L。样品的分析精密度（RSD％）小于5％和12％（Br）；标准加入回收率在80—134％之间。     

离子色谱-电感耦合等离子体质谱联用法测定海水中碘的形态

本文建立了离子色谱与电感耦合等离子体质谱联用对海水中碘的两种形态——碘酸根和碘离子进行同时检测的方法,以大比例稀释和大体积进样方式消除基体干扰。实验表明,以IonPac AS14分析柱,50mmol／L（NH4）4CO3（氨水调至pH10．0）为淋洗液,1mL／min流速,1mL的进样量,海水样品稀释200倍,IO3^-和I^-的方法检测限分别为2．60ug／L和4．60ug／L。回收率为101．9％和105．1％,相对标准偏差（n=7）为1．8％和2．6％。     

蔬菜鲜样中重金属镉的含量分析

本文选定五种新鲜蔬菜，选择湿式消解法消解后用石墨炉原子吸收分光光度法测定其中镉的含量。所检测的五种蔬菜中镉的含量均未超无公害蔬菜规定的限量指标。同时对两种蔬菜进行加标回收实验，加标回收率分别为88．3％和115％，测定最低检出限为0．2ug/Kg。     

ICP-AES测定酵母中有害重金属方法的研究

本文建立了高压罐消化-ICP-AES测定酵母中As、Cd、Pb、Cu、Hg的分析方法。As、Cd、Pb、Cu和Hg五种元素方法的相对标准偏差RSD分别为:5.55％、3.83％、4.04％、2.0％和 6.25％,回收率在 95～105％之间,检出限分别为:0.227μg As/g;0.0174μg Cd/g;0.103μg Pb/g;0.098μg Cu/g;0.015μg Hg/g。     

离子色谱-柱后衍生-紫外/可见分光光度法同时测定重水中六种微量过渡金属离子

建立了离子色谱－柱后衍生－紫外／可见光分光光度法同时测定重水中微量（μg·L－1）过渡金属离子Pb2+、Cu2+、Cd2+、Co2+、Zn2+和Ni2+的方法。探讨了淋洗剂流速、显色剂浓度、pH及流速对测定的影响。比较了重水和轻水的工作曲线。对照测试了自配标样和国家标准样品，结果完全相符。对上述六种离子检出限分别为3．7，2．0，13，2．2，2．9，6．0μg·L－1。相对标准偏差（RSD）分别为4．01％、3．03％、3．92％、2．57％、5．76％、1．9％。实测重水样品取得满意结果。     

复合添加VC／Cr3C2对超细硬质合金机械性能的影响

采用定总量变比例复合添加的方式，系统研究TVC和Cr3C2晶粒长大抑制剂总含量为0．8％条件下，VC和Cr3C2不同添加比例对WC-10％Co超细硬质合金力学性能及组织结构的影响。结果表明：VC$1Cr3C2的加入能够有效细化WC-10％Co合金晶粒，抑制C0池聚集，同时阻碍位错运动，强化粘结相，促进各种强化机制的充分发挥，进而改善合金的综合力学性能。在本试验条件下，WC-10％Co-0．2％VC-0．6％Cr3C2合金的综合力学性能最佳，其维氏硬度达1760，抗弯强度达4250MPa，断裂韧性达9．3MN3/2。     

卷烟中铅和镉的测定及评价

目的：选择某种品牌卷烟6种产品,分别进行测定卷烟中铅和镉的含量。方法：这两种重金属污染物采用石墨炉原子吸收法测定。结果：这6种卷烟中铅的质量浓度分别为4.2591ug/g、3.4663ug/g、4.0298ug/g、4.5284ug/g、4.0750ug/g、2.9540ug/g;镉的质量浓度分别为0.0867ug/g、0.0667ug/g、0.0741ug/g、0.0821ug/g、0.0763ug/g、0.0716ug/g。结论：卷烟中的铅和镉的质量浓度都未超过这两种重金属引起机体损伤的阈值浓度,但长期吸烟接触会对机体产生确定性的损伤效应。     

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.