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The purpose of this paper is to investigate the effects of chloride ion concentration and applied bias voltage on the electrochemical migration (ECM) behavior between Cu and Ag under an NaCl thin electrolyte layer (TEL).

A self-made experimental setup for the ECM behavior between Cu and Ag was designed. An HD video measurement microscopy was used to observe the typical dendrite/corrosion morphology and pH distribution. Short-circuit time (SCT), short-circuit current density and the influence of the galvanic effect between Cu and Ag on their ECM behavior were studied by electrochemical tests. The surface morphology and composition of dendrite were characterized by FESEM/EDS.

The SCT increased with increasing NaCl concentration but decreased with increasing applied bias voltage, and the SCT between Cu and Ag was less than that between Cu and Cu because their galvanic effect accelerated the dissolution and migration of Cu. When NaCl concentration was less than or equal to 6 mmol/L, cedar-like dendrite was formed, whereas no dendrite formed and only precipitation occurred at high chloride ion concentration (100 mmol/L). The composition of the dendrite between Cu and Ag was copper.

The significance of this study is to clarify the ECM failure mechanism of printed circuit board (PCB) with an immersion silver surface finish (PCB-ImAg).

This study provides a basic theoretical basis for the selection of protective measures and metal coatings for PCB.

The social implication of this study is to predict the service life of PCB.

The ECM behavior of dissimilar metals under a TEL was investigated, the influence of the galvanic effect between them on their ECM was discussed, and the SCT increased with increasing NaCl concentration.

The purpose of this study is to provide a theoretical basis for the study of the galvanic corrosion mechanism of copper coupled silver-coating under a thin electrolyte layer in electronic systems.

Electrochemical measurements and surface characterizations.

The results indicate that the potential difference between copper and silver electrodes first quickly increases, and then reaches a relatively stable and large value with the extension of the immersion time. With the significant increase in the cathode/anode area ratio in electronic systems, the area ratio effect obviously accelerates the corrosion of copper due to the remarkable promotion of the cathode process. For a large cathode/anode area ratio, the galvanic current density always maintains a large value and exhibits an increasing trend with the extension of the immersion time, which is attributed that the area ratio effect reduces the protection of corrosion products. For the same area of cathode and anode, the galvanic current density always maintains a small value with the extension of the immersion time due to a low galvanic effect and protective corrosion products.

This work provides some information for the establishment of reliably protective measures for electronic systems in service.

This work not only provides some information for the establishment of reliably protective measures for electronic systems in service, but also provides a theoretical basis for the selection of metal materials in microelectronic systems.

This work provides not only a theoretical basis for the study of the galvanic corrosion mechanism of Cu/Ag under a thin electrolyte layer, but also provides some information for the establishment of reliably protective measures for electronic systems in service.

This paper investigates the relationship between plot size and fertilizer use efficiency (FE) in Chinese large-scale farming and searches for the underlying mechanisms that explain this relationship.

Based on a household- and plot-level data set of large-scale production units (LSPUs) from Jiangsu and Jiangxi Provinces, the technical and fertilizer use efficiency of large-scale rice production is estimated by applying a translog stochastic frontier production function. The authors impose a monotonicity condition on the translog frontier using a three-step procedure to get theoretically consistent efficiency estimates. A beta regression model is then used to explore the association between plot size and LSPUs' efficiency in fertilizer application.

The average FE for the sampled plots is around 30%, which shows a large potential for LSPUs to reduce fertilizer use. A U-shaped relationship is observed between plot size and FE. The authors relate this non-linear pattern to the substitution of labour with capital-intensive technology and the efficiency differences in terms of farming performance between family and hired workers.

First, according to the authors’ knowledge, this paper is a first attempt to study the size–efficiency relationship focussing on fertilization practices of large-scale farming. The second contribution lies in the large-scale ranges of the plot-level data set. Third, efforts are made to reveal the mechanisms determining the plot size–FE relationship. Fourth, the authors provide guiding evidence for policymaking, as they show that the size of individual plots deserves equal attention in land consolidation decisions. Methodologically, this paper improves existing estimates of single-factor technical efficiency issued from a restricted production frontier model.

This paper aims to propose a hybrid force/position control algorithm based on the stiffness estimation of the unknown environment. A frequency-division control scheme is developed to improve the applicability and reliability of the robot in welding, polishing and assembly.

The stiffness estimation algorithm with time-varying forgetting factors is used to improve the speed and accuracy of the unknown environmental estimation. The sensor force control and robot position control are adopted in different frequencies to improve system stability and communication compatibility. In the low frequency of sensor force control, the Kalman state observer is used to estimate the robot’s joints information, whereas the polynomial interpolation is used to ensure the smoothness of the high frequency of robot position control.

Accurate force control, as well as the system stability, is attained by using this control algorithm.

The entire algorithm is applied to a six-degrees-of-freedom industrial robot, and experiments are performed to confirm its applicability.

The frequency-division control strategy guarantees the control stability and improves the smoothness of the robot movement.

The segmentation of printed circuit board (PCB) images is an important process in PCB inspection. The circuit traces, pads and vias in a PCB are dense and curved, and the PCB image obtained using different cameras or in different conditions may exhibit a large image gradient, which leads to inaccuracy and inefficiency in the PCB image segmentation. This paper aims to propose an improved local binary fitting level set method with prior graph cut, aiming to improve the accuracy and efficiency of the segmentation of PCB images obtained using different cameras or in different environments.

First, the paper constructs a 4-connected undirected graph using a given PCB image and classifies it based on the graph cut. Second, an adaptive initialization level set is implemented using the priori information obtained from the graph cut. Finally, the paper constructs a priori energy term using the prior information and introduces it into the energy function of the level set.

The approach results in an improved accuracy of segmentation in the context of a large gradient within the image. Experimental results demonstrate that the method can solve the deviation of artificially initialized level set from targets and improve the efficiency and accuracy of segmentation.

This study only considers level set method as the research object. Iteration of the level set method takes a long time for a given huge PCB picture, which makes it impossible to apply to scenes with high real-time requirements.

PCB image segmentation is an important process in the PCB inspection. Since template matching and morphology techniques are well-established, image segmentation quality has a significant impact on the accuracy of detection.

This paper studies the segmentation of PCB images, improves the efficiency and accuracy of segmentation and facilitates the subsequent applications, such as in the nondestructive testing of PCB.

Following a guanxi value – buyer‐seller relationship quality – marketing behaviour scheme, this paper aims to explore how traditional guanxi supports small vegetable farmers in modern markets in China.

Fieldwork was performed in Jiangsu Province, PR China. A stratified random sample of 167 vegetable farmers provided data for empirical testing with partial least squares analysis.

The findings suggested that the value of guanxi networks is an antecedent to buyer‐seller relationship quality and marketing behaviour in China. Guanxi networks improve the quality of buyer‐seller relationships in terms of interpersonal trust and satisfaction. Buyer‐seller relationships influence smallholders' transaction relationships, their participation in modern markets and choice for formal contracts. Guanxi networks not only support Chinese small‐scale vegetable farmers to get access to modern high‐value markets (e.g. supermarkets and international markets), but also encourage informal transactions in the vegetable business.

Guanxi networks play a critical role in the modern marketing environment in China. Marketing strategies based on personal relationships should be further enhanced in order to increase participation of smallholders in modern markets.

Quantitative evaluation of the effects of the Chinese cultural embedded concept of guanxi in the Chinese agrifood sector fills in an important research gap.

The purpose of this paper is to provide a structured demand chain design framework that can be linked with gateway and corridor management practices.

The model in this paper presents supply and demand thrusts that could leverage Canada's position in international food trade.

Since a direct correlation exists between the wealth of a nation and how it consumes food, the paper first presents five utilities and several factors that are perceived differently by customers once a nation becomes affluent. Then it presents supply and demand thrusts that could leverage Canada's position in international food trade. Finally, a demand chain design framework is suggested.

The framework is meant to be organically generic and not applied to one specific commodity or market, as all commodities and targeted markets necessitate an idiosyncratic approach. Although it is met to be applicable to topographies that offer logistical challenges such as Canada.

It has been recognized that agriculture and food companies have a long tradition of being commodity‐driven, with an emphasis on production technology, high volumes, and quality consistency. In the context of global hyper‐competitivity, the ability to understand customer needs and adapt to a wider variety of customer situations will become crucial.

Without being specific to a targeted market or commodity, a demand chain management framework for food products is presented which provides an integrative approach for demand chain design based on food marketing practices, and which requires continuous evaluation of perceived utilities by customers.