厚板高强铝合金焊接发展现状及展望

结合高强铝合金焊接的特点、难点,介绍了几种目前国际上焊接高强厚板铝合金的新工艺,新方法--搅拌摩擦焊、双丝MIG焊、激光-电弧焊;与传统电弧焊相比,它们在厚板高强铝合金焊接方面更具优越性.     

选矿厂细磨磨矿介质的选择及研究

介绍、分析研究了选矿厂细磨中的磨矿介质选择的方法。从磨矿介质的尺寸、形状、材质 3个方面 ,进行了理论研究和实验验证 ,提出了一个可行的方案。     

激光焊接在欧洲造船业的应用

为了在竞争中获胜，欧洲造船业必须提高生产速度和效率，同时降低成本。因此，他们投入了巨大的人力和财力来研发激光焊接并将其应用到造船生产实践中，以达到维持和重建欧洲船厂在全球高附加值船舶市场的优势地位。     

A novel supercapacitor-fuel cell hybrid cell

A monolithic hybrid fuel cell (MHFC) with a novel configuration was proposed in an effort to improve the fuel cell performance during instantaneous power changes. A modified direct methanol fuel cell (DMFC) with a layer of hydrous ruthenium dioxide (RuO2·xH2O) sandwiched between the anode catalyst layer and membrane was used to demonstrate the principle of the MHFC. Experimental results indicate that the RuO2·xH2O layer is equivalent to a resistor-capacitor transmission line and functions similar to a capacitor in parallel with the anode electrode. The improvement in dynamic response of the MHFC was experimentally confirmed under step current change and square current pulse operating. The ionic conductivity of the RuO2·xH2O layer was also obtained.     

光纤通信技术在渠道长距供水信息系统中的设计与应用

长距离供水渠道地处偏远,点多线长,采用信息化技术手段进行远程集中控制成为必然,光纤通信技术作为远控的基础显得尤为重要。文章介绍了南干渠供水信息系统中建设光纤通信系统的必要性和重要性,以及光纤通信系统结构、系统链路和系统设备选型,以达到无人值班、少人值守、集中控制的设计目标。     

广东省水雨情遥测数据统一接收方案探讨

基于广东省水情遥测数据接收系统为分散接收的现状,在新的技术条件下,为加强水情报汛数据传输的及时性和可靠性,探讨全省水雨情数据统一接收方案,即在新的通信规约框架下,水雨情遥测站将数据一站双发至省水情中心和热备份中心(或水情分中心),建设全省水雨情遥测数据统一接收平台,实现水情报讯数据传输的及时性和可靠性。     

白龟山水库遥测系统北斗卫星信道建设

针对河南省白龟山水库水情自动测报系统的现状,提出以短信和北斗卫星2种信道同时作为系统主信道的升级改造方案,极大地增强系统的稳定可靠性和抵抗自然灾害能力,解决在连续阴雨天气、交流电停电、网络中断等极端条件下系统不能独立正常运行的问题。其在利用北斗通信信道方面作出的成功探索,对其它水情自动测报系统的建设有很好的借鉴意义。     

College students and risk-taking behaviour on Twitter versus Facebook

The propensity of college students to post content that they know may be unacceptable to future employers or other authority figures has been well established. Yet research on this topic has tended to focus exclusively on Facebook, which is problematic for two reasons. First, many young social media users are shifting away from Facebook and towards Twitter and other services. Second, college students have changed their use of social media over time and may now be more cautious about what they post on Facebook. To address this issue, a survey-based field study was conducted to compare student comfort levels with authority figures viewing their Facebook and Twitter accounts. Specifically, undergraduate business students attending a large university in the midwest of the USA were surveyed about their Facebook and Twitter accounts. Findings indicate that college students are markedly less comfortable with authority figures viewing their Twitter accounts. Paradoxically, a great majority of the study respondents were found to have public Twitter accounts, while only a very small minority have public Facebook accounts. This finding suggests that students perceive less risk on Twitter versus Facebook or that they are writing to different imagined audiences on the two platforms. Implications include the need for further inquiry and an awareness of educators and human resources professionals about students’ current social media practices.     

Adoption of travel information in user-generated content on social media: the moderating effect of social presence

Travel patterns have gradually changed from group travel to individual travel. An increasing number of people acquire travel information through various types of media. One of the alternative information sources is social media, which enables users to exchange information among members. However, one of the characteristics of social media is information sharing, not information search, which involves both giving (i.e. posting) and taking (i.e. selective reading, forwarding, replying, linking, and liking) information. Compared to the ‘giving’ side of information-sharing research, less effort has been spent on the ‘taking’ side of information research. Therefore, we investigate travel information adoption in social media as well as how individuals communicate with each other. We use the elaboration likelihood model, which measures the impact of central (e.g. argument quality) and peripheral (e.g. credibility) cues on traveller information-sharing behaviour corresponding with social presence on social media. The results of an empirical analysis of 527 respondents, who were experienced in travel information adoption via social media, were examined. Our findings revealed that argument quality had a positive effect on perceived usefulness and source credibility positively affected perceived usefulness and social relationships. Perceived usefulness had a significant positive effect on social relationships. Both perceived usefulness and social relationships affected travel information adoption. Lastly, the levels of argument quality and source credibility perceived by social media members were found to differ according to the level of social presence.     

Computation of optimum reliability acceptance sampling plans in presence of hybrid censoring

The decision regarding acceptance or rejection of a lot of products may be considered through variables acceptance sampling plans based on suitable quality characteristics. A variables sampling plan to determine the acceptability of a lot of products based on the lifetime of the products is called reliability acceptance sampling plan (RASP). This work considers the determination of optimum RASP under cost constraint in the framework of hybrid censoring. Weibull lifetime models are considered for illustrations; however, the proposed methodology can be easily extended to any location-scale family of distributions. The proposed method is based on asymptotic results of the estimators of parameters of lifetime distribution. Hence, a Monte Carlo simulation study is conducted in order to show that the sampling plans meet the specified risks for finite sample size.