数控喷涂机伺服进给系统的设计与研究

介绍一种适合高速轻载的直线进给系统的结构形式。通过对数控喷涂机横向进给系统的设计研究，并对同步带直接驱动单元的结构形式和特点的分析，得出一种适于高速轻载的直线进给系统的驱动方式。     

X65钢焊接接头在模拟浅表海水和深海环境中的腐蚀行为对比

在实验室模拟条件下,采用失重法及电化学等方法并结合腐蚀形貌显微观察,研究了X65钢焊接接头在浅表海水和深海(1000 m)环境中的短期腐蚀行为及其机理。结果表明,X65钢焊接接头在浅表海水环境下的腐蚀速率大于深海环境下的腐蚀速率,浅表海水环境以点蚀为主,深海环境只在熔合线附近腐蚀相对较快,焊缝区腐蚀不明显;在模拟浅表海水和深海环境下,热影响区(HAZ)的腐蚀电位均低于焊缝和母材区,导致焊缝区域存在电偶效应,加速了HAZ的腐蚀,形成较厚的腐蚀产物膜。     

The Effect of CeO2 Antireflection Layer on the Optical Properties of Thermochromic VO2 Film for Smart Window System

CeO₂-VO₂ bilayer structure was fabricated to investigate the effect of depositing CeO₂ film on the optical properties of VO₂ film for smart window application. CeO₂ was employed as an antireflection (AR) layer material of VO₂ film because of its advantages which include high transparency in the visible-near infrared range and high refractive index. All the films were deposited on soda-lime glass substrate by pulsed laser deposition method. Optical calculations were carried out using transfer-matrix method for the purpose of designing CeO₂-VO₂ bilayer structure with enhanced integrated luminous transmittance (T _lum) and switching efficiency (ΔT _sol). The optical constants of VO₂ and CeO₂ films needed for the optical calculation were measured by spectroscopic ellipsometer. The curve of T _lum the shape of which depends on the thickness of CeO₂ layer, was calculated in each VO₂ sample, which showed two maxima. The samples were divided into two groups; one for the highest enhancement of T _lum and the other for balanced enhancement between T _lum and ΔT _sol. The sample with the structure of ~60 nm CeO₂ AR layer on 39-nm thick VO₂ film showed large increase of T _lum (~27%) with ΔT _sol of ~5%, which is the largest increase in T _lum reported so far. Two samples in the other group showed the balanced enhancement in T _lum (~57, ~50%) and ΔT _sol (~9, ~10.5%). The effect of CeO₂ AR layer on the optical properties of VO₂ film was confirmed with the optical calculation and the experimental results. CeO₂-VO₂ bilayer structure showed notable improvement of optical properties compared to the single VO₂ film, indicating that CeO₂ layer can be effectively used as the antireflection layer while working as a protective layer that can prevent the oxidation of VO₂ layer as well.     

Integrated constitutive model for flow behavior of pure Titanium considering interstitial solute concentration

The aim of this work is to develop a constitutive model that can predict the flow behavior of pure Ti with different interstitial concentrations and grain sizes. To build a database required for identifying material constants, three different grades of Ti were subjected to tensile tests at temperatures of 223, 300, 473, 673 or 773 K and at a fixed strain rate of 10^?3 s^?1. In the modeling procedure, the mechanical threshold stress model was further modified to capture both the hardening effects attributed to the changes in equivalent oxygen concentration (O _eq ) and the softening effect caused by deformation heating at high strain rates. The developed model can reasonably predict the flow behavior of pure Ti having different O _eq (0.14–0.32 wt%), and grain size (14.5–90 μm) over a temperature range of 135 to 673 K, and a strain rate range of 2×10^?4 to 1400 s^?1.     

Differential Domain Distribution of gnomAD- and Disease-Linked Connexin Missense Variants

Twenty-one human genes encode connexins, a family of homologous proteins making gap junction (GJ) channels, which mediate direct intercellular communication to synchronize tissue/organ activities. Genetic variants in more than half of the connexin genes are associated with dozens of different Mendelian inherited diseases. With rapid advances in DNA sequencing technology, more variants are being identified not only in families and individuals with diseases but also in people in the general population without any apparent linkage to Mendelian inherited diseases. Nevertheless, it remains challenging to classify the pathogenicity of a newly identified connexin variant. Here, we analyzed the disease- and Genome Aggregation Database (gnomAD, as a proxy of the general population)-linked variants in the coding region of the four disease-linked α connexin genes. We found that the most abundant and position-sensitive missense variants showed distinct domain distribution preference between disease- and gnomAD-linked variants. Plotting missense variants on topological and structural models revealed that disease-linked missense variants are highly enriched on the structurally stable/resolved domains, especially the pore-lining domains, while the gnomAD-linked missense variants are highly enriched in the structurally unstable/unresolved domains, especially the carboxyl terminus. In addition, disease-linked variants tend to be on highly conserved residues and those positions show evolutionary co-variation, while the gnomAD-linked missense variants are likely on less conserved residue positions and on positions without co-variation. Collectively, the revealed distribution patterns of disease- and gnomAD-linked missense variants further our understanding of the GJ structure–biological function relationship, which is valuable for classifying the pathogenicity of newly identified connexin variants.     

Agent-based flight planning system for enhancing the competitiveness of the air cargo industry

In this paper, we propose a multi-agent-based framework to facilitate process automation for the air cargo industry. The focus is on enhancing two labor-intensive flight planning processes, namely cargo consolidation and equalization. By employing a software agent-based flight planning module, which is linked with an RFID-based warehouse management system, air cargo items received at a freight forwarder’s warehouse can be processed more efficiently and flight plans can be generated automatically. In particular, we employ agents equipped with simulated annealing optimization engines to handle the time-consuming tasks of optimization. By doing so, the latest flight plans can be generated more efficiently. The system has been evaluated experimentally by both simulated and real-life data. The results are encouraging. For example, operation steps that normally require over 30 minutes to complete can now be carried out in as quickly as two minutes, and produce a better solution.     

Pricing and promotion strategies of an online shop based on customer segmentation and multiple objective decision making

The advent of the Internet and web technologies has enabled the prosperity of virtual stores, which greatly reduce customers’ search costs and retailers’ overhead. However, the furious competition between online shops makes it difficult for them to generate profits. This study attempts to establish pricing and promotion strategies for online shops to enhance their profitability. The pricing decision is based on the concept of customer relationship management, where a greater margin of price concession is given to customers who are more valuable to the shop. The process of our approach is: clustering customers into different classes based on their RFM data, computing and presenting the list prices of products to customers according to their classes, allowing customers to bargain over the price and offering conceded prices which are computed based on customer classes and a multi-objective decision making model, and finally providing promotion options to customers to reinforce their purchase inclination. The proposed approach is implemented at an online shop of a computer peripherals retailer. Transaction data before and after the implementation are collected and compared to assess the performance of the proposed approach.     

Consequences of the photodynamic treatment of resting and activated peripheral T lymphocytes

Silencing of the cryptic mating-type loci HMR and HML requires the recognition of DNA sequence elements called silencers by the Sir1p, one of four proteins dedicated to the assembly of silenced chromatin in Saccharomyces cerevisiae. The Sir1p is thought to recognize silencers indirectly through interactions with proteins that bind the silencer DNA directly, such as the origin recognition complex (ORC). Eight recessive alleles of SIR1 were discovered that encode mutant Sir1 proteins specifically defective in their ability to recognize the HMR-E silencer. The eight missense mutations all map within a 17-amino-acid segment of Sir1p, and this segment was also required for Sir1p's interaction with Orc1p. The mutant Sir1 proteins could function in silencing if tethered to a silencer directly through a heterologous DNA-binding domain. Thus the amino acids identified are required for Sir1 protein's recognition of the HMR-E silencer and interaction with Orc1p, but not for its ability to function in silencing per se. The approach used to find these mutations may be applicable to defining interaction surfaces on proteins involved in other processes that require the assembly of macromolecular complexes.