化学镀镍磷合金在纺纱钢丝圈上的应用研究

对表面经不同方法抛光处理后的纺纱钢丝圈进行了酸性镀液化学镀镍磷合金试验。镀液主要由NiSO4·6H2O,NaH3PO2·H2O和适量络合剂、稳定剂等组成,施镀温度85℃,施镀时间1h。与国产主流产品电镀镍钢丝圈相比,除施镀工艺具有更好的环保性外,上车试用结果表明,经精抛处理后、镀态下具有细致的非晶态结构、光滑表面和一定镀层厚度的高磷镀层钢丝圈能与钢领之间更快速地建立起稳定的运行过程,缩短走熟期;成纱质量高,毛羽短而少;耐磨寿命从5~7天延长至20天以上。     

Ni-P-SiC复合镀工艺及镀层性能研究

采用化学镀方法制备了Ni-P-SiC复合镀层，研究了镀液中第2相粒子浓度对Ni-P-SiC复合镀层镀速及显微硬度的影响，对比了纯NiP镀层和复合镀层膜基系统的结合力。结果表明，在SiC浓度为8g／L时，得到最大的镀速和硬度值，并且此时的膜基系统结合力要优于纯NiP镀层的膜基结合力。     

高碳钢表面Ni-P/纳米Ti(C,N)化学复合镀研究

研究了高碳钢表面Ni-P/纳米Ti(C,N)化学复合镀工艺以及热处理对复合镀层性能的影响。结果表明:施镀工艺中各因素对镀速影响的显著性顺序是pH值>镍磷比>施镀温度>纳米Ti(C,N)加入量;较好的施镀工艺为硫酸镍为25g/L、次亚磷酸钠为29.9g/L、乳酸为34g/L、乙酸钠为4g/L、PbCl2为0.001g/L、Ti(C,N)为6g/L、pH值为4、施镀温度为80℃;复合镀层较佳的热处理工艺为400℃保温45min,空冷。在最佳工艺下,得到的Ni-P/纳米Ti(C,N)复合镀层的硬度为975.2HV,是高碳钢基体硬度的3.8倍,且镀层与基体的结合力强。     

Al2O3增强镍-磷-钨复合镀层的制备及性能

为了提高镍-磷-钨合金镀层性能,制备了Al2O3增强的镍-磷-钨复合镀层;探讨了镀液中Al2O3颗粒尺寸、搅拌方式、电流密度、镀液中Al2O3、Na2WO4的含量和pH值等对镀速、镀层中Al2O3的质量分数及镀层外观质量的影响;确定了复合电沉积最佳工艺条件;并对镀层的硬度、耐磨性能、抗高温氧化性能、耐腐蚀性能、表面形貌、相结构和化学成分等进行了测试.结果表明:在超声波振荡搅拌下,加入纳米Al2O3,控制电流密度为2A·cm-2,镀液中Al2O3和Na2WO4的含量分别为50g·L-1和6g·L-1,pH值为5.0时,镀速和镀层中的Al2O3质量分数最大,镀层质量最佳;加入微米和纳米Al2O3镀层的综合性能均高于未加入Al2O3的镀层.     

钾盐光亮镀锌工艺

钾盐光亮镀锌工艺是目前工业上较为理想的电镀新工艺。现根据生产实践经验和有关资料，将该工艺的主要技术特性、镀锌镀液的配制、镀液成分和操作条件的影响、镀液的维护以及镀液中有害成分的去除等内容介绍如下。一、钾盐光亮镀锌工艺的主要技术特性1．阴极电流效率不低于98％。2．镀液的沉积速度镀层厚度可达32μm／h，最厚能达35μm/h。3．分散能力20℃赫尔槽试总电流1A，赫尔槽两点测定分散能力是，亚号光亮剂为24％，2号光亮剂为28．4％。4．深镀能力采用φ10mm通孔钢管，外部绝缘并正对阳级，在30℃倾斜放置的条件下，当电镀时间为20…     

Ni-La2O3纳米复合镀层制备工艺研究

将La2O3纳米颗粒添加到氨基磺酸镍镀液中采用电沉积方法制备Ni-La2O3纳米复合镀层，研究了多种因素对复合镀层中La2O3含量的影响，分析了复合镀层的表面形貌和显微硬度。结果表明：试验条件下最佳工艺为电流密度2A／dm^2、镀液温度50℃、搅拌速度800r／min、镀液中La2O3含量30g／L；与纯镍镀层相比，复合镀层表面平整光滑、组织致密均匀；其显微硬度也高于纯镍镀层，并随着复合镀层中La2O3含量的增加而升高。     

电压对电刷镀纯钴镀层组织和性能的影响

采用电刷镀方法在GH4169表面制备了纯钴镀层。镀液组成和工艺参数为:CoSO4·7H2O 430 g/L,H3BO330 g/L,NaCl 5 g/L,pH=4.0,温度为25℃,电压为10～28 V。研究了电压对纯钴镀层的表面形貌、相结构、显微硬度和耐磨性的影响。结果表明:随着电压的增大,镀层表面平整度不断提高,组织结构也有所改善,硬度和耐磨性也不断上升。但是当电压大于22 V时,平整度不断下降,晶粒变大,硬度和耐磨性不断下降。     

碳纳米管/镍复合镀层硬度研究

在瓦特镀镍溶液中加入碳纳米管,研究球磨处理、搅拌分散形式、分散剂对碳纳米管在镀液中均匀稳定分散的影响,采用恒电流电沉积工艺制备了碳纳米管／镍复合镀层。结果表明：碳纳米管球磨后加入到镀液中,并通过超声分散,可以得到稳定的复合电镀液;碳纳米管与镍能很好地共沉积。当阴极电流密度为2．5A／dm^2、镀液温度为45℃、碳纳米管加入量为0．8～1．2g／L时镀层显微硬度达到最大值。     

镀液中La_2O_3含量对Ni-W-La_2O_3复合镀层组织和性能的影响

本文对在镀液中添加不同含量La2O3微粒对Ni-W-La2O3复合镀层组织和性能的影响进行研究。结果表明,镀液中La2O3微粒含量为4 g/L时,Ni-W-La2O3复合镀层组织均匀致密、表面平整,硬度高,耐高温和耐腐蚀性能好。     

ABS塑料低温化学镀Ni—P合金新工艺

对传统ABS塑料化学镀镍工艺进行了改进。化学粗化时,成功地以含有一定量添加剂的强碱性高锰酸钾型工艺代替工业上普遍使用的高铬酸型工艺;其次,在40－50℃下,采用双络合剂的化学镀铜浴在ABS表面预镀铜;最后,使用含有添加剂和组合络合剂的碱性化学镍浴进行化学镀镍。结果表明：在35－40℃、pH=9.5、装载量为1．0dm^2/L时施镀,镀速为9．8μm/h,镀层光亮,无裂纹,镀液稳定,耐蚀性良好。     

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.     

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。     

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....     

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.     

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.