废线路板火法熔炼过程控制及炉体设备的研究与实践

我国是世界最大的电器电子产品生产国和消费国,印刷电路板是现代电子工业的基础。随着电子产品更新换代速度越来越快,废电路板的产生量也随之增加。结合废线路板的资源属性,对废线路板火法熔炼过程控制进行了初步探讨,对顶吹熔炼炉耐火材料的优化进行了系统的研究,并进行了生产实践验证,为废线路板等铜基固废的资源再生提供了新的产业化路径。     

Scalable fabrication of novel SiC nanowire nonwoven fabric

Flexible papers constructed by one-dimensional nanowires have attracted much attention due to their various applications. Herein, a novel nonwoven fabric with paper-like qualities composed of zinc blende SiC (β-SiC) nanowires was fabricated by a scalable rolling process. The SiC nanowires were synthesized by the carbothermal reduction reaction of the carbon fiber and carbonaceous silica xerogel. The crystal phase, morphology and microscopic structure of the as-prepared SiC nanowires were characterized by field emission scanning electron microscope, X-ray diffraction and high-resolution transmission electron microscopy. The nanowire vapor–solid growth mechanism and preparation process for SiC nanowire nonwoven fabric were also discussed. The freestanding SiC nanowire nonwoven fabric exhibited high flexibility, high mechanical strength, excellent refractory performance and thermal stability. With high flexibility, high mechanical strength, superior nonflammability and thermal stability, the flexible paper-like 3C-SiC nanowire nonwoven fabric materials would be expected to have some potential applications, such as ceramic matrix composites, metal matrix composites, energy storage, catalyst supports, radiation-proof fabric, filtration and separation.     

Semantic word shifts in a scientific domain

Understanding semantic word shifts in scientific domains is essential for facilitating interdisciplinary communication. Using a data set of published papers in the field of information retrieval (IR), this paper studies the semantic shifts of words in IR based on mining per-word topic distribution over time. We propose that semantic word shifts not only occur over time, but also over topics. The shifts are examined from two perspectives, the topic-level and the context-level. According to the over-time word-topic distribution, stable words and unstable words are recognized. The diverging and converging trends in the unstable type reveal characteristics of the topic evolution process. The context-level shifts are further detected by similarities between word vectors. Our work associates semantic word shifts with the evolving of topics, which facilitates a better understanding of semantic word shifts from both topics and contexts.     

An isogeometric independent coefficients (IGA-IC) reduced order method for accurate and efficient transient nonlinear heat conduction analysis

This article develops an isogeometric independent coefficients (IGA-IC) reduced order method for transient nonlinear heat conduction analysis. Herein, we first exactly represent the geometric model via isogeometric analysis (IGA), and therein provide an accurate solution for the semi-discretized equations. Next, our proposed GSSSS-1 time-stepping framework is employed to solve the transient nonlinear temperature in space and time domains. We advance our independent coefficients (IC) reduced order method to efficiently solve IGA-based transient nonlinear heat conduction problems. We extend the IC method to significantly reduce the original full IGA-discretized formulations and calculate the reduced equilibrium formulations in each Newton–Raphson iteration. Thereby, hugely improving the efficiency and guaranteeing the accuracy simultaneously. Illustrative numerical examples validate this proposed IGA-IC method is reliable, accurate, and efficient; especially, the larger the scale of the problem, the more advantages the proposed IGA-IC will inherit.     

A Multi-Radio Multi-Channel Assignment Algorithm Based on Topology Control and Link Interference Weight for a Power Distribution Wireless Mesh Network

Wireless Personal Communications - In this paper, a multi-radio multi-channel (MRMC) assignment algorithm based on topology control and link interference weight for power distribution wireless mesh...     

Privacy-Preserving and Energy-Efficient Continuous Data Aggregation Algorithm in Wireless Sensor Networks

Wireless Personal Communications - Privacy-preserving continuous data aggregation in wireless sensor networks has broad application prospects, such as environmental monitoring, health care, etc....     

Biodegradable Spheres Protect Traumatically Injured Spinal Cord by Alleviating the Glutamate‐Induced Excitotoxicity

New treatment strategies for spinal cord injury with good therapeutic efficacy are actively pursued. Here, acetalated dextran (AcDX), a biodegradable polymer obtained by modifying vicinal diols of dextran, is demonstrated to protect the traumatically injured spinal cord. To facilitate its administration, AcDX is formulated into microspheres (≈7.2 µm in diameter) by the droplet microfluidic technique. Intrathecally injected AcDX microspheres effectively reduce the traumatic lesion volume and inflammatory response in the injured spinal cord, protect the spinal cord neurons from apoptosis, and ultimately, recover the locomotor function of injured rats. The neuroprotective feature of AcDX microspheres is achieved by sequestering glutamate and calcium ions in cerebrospinal fluid. The scavenging of glutamate and calcium ion reduces the influx of calcium ions into neurons and inhibits the formation of reactive oxygen species. Consequently, AcDX microspheres attenuate the expression of proapoptotic proteins, Calpain, and Bax, and enhance the expression of antiapoptotic protein Bcl‐2. Overall, AcDX microspheres protect traumatically injured spinal cord by alleviating the glutamate‐induced excitotoxicity. This study opens an exciting perspective toward the application of neuroprotective AcDX for the treatment of severe neurological diseases.     

Modeling the customer satisfaction function: a two-country comparison

This paper provides a framework that integrates and reinterprets prior research on satisfaction modeling (function) and proposes the existence of non-linear and curvilinear/higher-order relationships to model online banking customers. It provides a framework that examines two closely related but distinct countries—Malaysia, a developing country, and Singapore, a developed country—and identifies whether modeling online banking customers through satisfaction is unique to each context or is generic. Using a systematic and step-by-step hierarchical moderated regression approach, this study tries to understand the relationship among repurchase intention, satisfaction, and trust, moderated by bank size. Malaysia portrays a linear relationship, while Singapore depicts non-linear and curvilinear/high-order relationships. The findings suggest that modeling online banking customers through satisfaction depends on a country’s economic development. By contrast, prior studies on modeling customers through satisfaction were conducted independently and did not employ proper and systematic steps to capture the satisfaction function.     

Image authentication and tamper localization based on relative difference between DCT coefficient and its estimated value

Digital images are increasingly transmitted over non-secure channels such as Internet, therefore image authentication techniques have recently gained great attention due to their importance for a large number of multimedia applications. To protect the authenticity of images, several approaches have been proposed. These approaches include conventional cryptography, semi-fragile watermarking and digital signatures. In this paper, we propose two techniques of the same type based on what we call characteristic data digest. Both techniques can blindly detect and localize malicious tampering, while maintaining reasonable tolerance to conventional content-preserving manipulations. The characteristic data is derived from the relative difference between each pair of selected DCT coefficient, AC for one technique and DC for another technique, in a central block and its counterpart estimated by the center block and its adjacent blocks. In order to maintain the relative difference relationship when the image undergoes legitimate processing, we make a pre-compensation for the coefficients. Experimental results show that our techniques are significantly superior to semi-fragile techniques under the condition of the same image fidelity, especially in tolerance range of legitimate processing, and/or the ability to detect and localize the tampered area. Due to the simplicity of the algorithms, our techniques can be used in video frame authentication, and even other digital media. In addition, this kind of proposed techniques can be extended to use other characteristic data, such as high-level moment, statistical data of images, and so on.

     

A dynamic SVR–ARMA model with improved fruit fly algorithm for the nonlinear fiber stretching process

Natural Computing - The fiber stretching process plays the key role in the process of fiber production and its effects is measured by the stretching ratio. The stretching ratio is determined by the...