河南上宫金矿地质特征及矿床成因

上宫金矿位于华北地台熊耳山隆起部位,大型断裂带龙脖—花山背斜的南翼。矿区出露地层主要为中元古界熊耳群许山组火山岩系,这套火山岩化学成分表现为富铁、多钾、低钙铝的特点。矿区内断裂发育,以北东向为主,近南北向和近东西向次之。文章通过对上宫金矿成矿地质特征的分析,结合前人的研究成果,归纳出上宫金矿床地层、构造、岩浆岩三位一体的控矿机制,提出了地层、构造—岩浆岩以及围岩蚀变3个典型的找矿标志。     

Integer programming methods for large-scale practical classroom assignment problems

In this paper we present an integer programming method for solving the Classroom Assignment Problem in University Course Timetabling. We introduce a novel formulation of the problem which generalises existing models and maintains tractability even for large instances. The model is validated through computational results based on our experiences at the University of Auckland, and on instances from the 2007 International Timetabling Competition. We also expand upon existing results into the computational difficulty of room assignment problems.     

Effect of preparation method on physicochemical properties and catalytic performances of LaCoO_3 perovskite for CO oxidation

Perovskite oxides LaCoO_3 prepared by templating, co-precipitation and sol-gel method with different complexants were systematically characterized and its catalytic performances for CO oxidation were investigated. The samples were characterized by X-ray diffraction, thermogravimetry analysis and differential scanning calorimetry, N_2 physisorption, transmission electron microscopy, temperature program reduction of hydrogen, temperature program desorption of oxygen and X-ray photoelectron spectroscopy measurement, results of which show that the properties of LaCoO_3, such as surface morphology, surface area, surface compositions, redox capability, oxygen vacancy, as well as the calcination temperature and formation mechanism, depend intimately on the preparation method. Catalytic tests indicate that the sample prepared by carbon templating method shows the best activity for CO oxidation, with full CO conversion obtained at 135 ℃. In particular, the catalyst can be activated and significant increase of activity can be obtained with the increase of reaction time. The cyclic and longterm stability of catalysts were discussed and compared.     

Thermoelectric properties of plasma sprayed of calcium cobaltite (Ca2Co2O5)

The thermoelectric properties of calcium cobaltite deposits produced by the plasma spray process are investigated from room-temperature to 873 K. Synthesis of Ca₃Co₂O₆ and Ca₂Co₂O₅ powders were prepared by the solid-state reaction from CaO and CoO_x starting powders. During their subsequent plasma spray Ca particles experience preferential evaporation within the plasma, resulting in a complex interplay among process conditions, stoichiometry, and resultant phases. The as-sprayed material predominantly contains amorphous and secondary phases. Upon annealing, the deposits show sensitivity to phase evolution and therefore thermoelectric properties. Through screening studies, optimal annealing conditions were identified which show a p-type Seebeck coefficient value of 180 μV K^?1, electrical conductivity of 1.09 × 10⁴ S m^?1, thermal conductivity of 1.16 W m^-1 K^-1 at 873 K. The resultant figure of merit value reached 0.266 for this combination of processing and thermal treatment and is in line with data reported from other techniques for this system.     

Development and validation of New Media Literacy Scale (NMLS) for university students

Along with the emergence of new media technologies, individuals are now expected not only to consume but also produce, share and criticize digital contents. Being new media literate, they also need to know socio-cultural and emotional aspects of new media beyond its technical characteristics. New media literacy (NML) involves a series of crucial skills needed for living and working in the mediated and participatory society of 21st century. Although there has been a growing interest in the conceptualization of NML, the literature lacks a measuring instrument to operationalize NML. This study attempts to fill this gap by developing and validating a NML scale (NMLS) for university students. The sample included 1226 students at a state university in Turkey. Both exploratory and confirmatory factor analyses as well as item analyses including internal consistency coefficients, item-total correlations, and item discrimination powers were conducted to determine construct validity and reliability. Consistent with the adopted theoretical framework, the 35-item NMLS comprised four factors: Functional Consumption, Critical Consumption, Functional Prosumption, and Critical Prosumption. Potential applications of NMLS for measuring students’ new media competencies were discussed within the pedagogical and research contexts.     

What makes you a digital native? Is it enough to be born after 1980?

The purpose of this study is to determine levels of technological proficiency among university students to see if they should be characterized as “digital natives.” For this purpose, rather than using types and frequency of technology use to characterize a digital native, the Digital Native Assessment Scale (DNAS) developed by Teo (2013) was employed. This scale has an established reliability and validity measure. It measures several factors (e.g., grew up with technology, comfortable with multi-tasking, reliant on graphics for communication, thrive on instant gratifications and rewards, etc.) relating to accepted characteristics of a digital native. The participants in the study were 560 university students, 278 of whom were from Turkey and 282 from Kyrgyzstan. The findings indicate that these university students actively used computers and the Internet. The statistical results show that digital natives can be characterized by including their academic year (Freshman, Sophomore, etc.), national culture, and experiences with technology (computers, tablet PCs, and the Internet). The results also indicate that there are no significant differences in the participants' perceptions of themselves as digital natives due to their gender or academic disciplines.     

“Facebocrastination”? Predictors of using Facebook for procrastination and its effects on students’ well-being

Procrastinating with popular online media such as Facebook has been suggested to impair users’ well-being, particularly among students. Building on recent procrastination, self-control, and communication literature, we conducted two studies (total N = 699) that examined the predictors of procrastination with Facebook as well as its effects on students’ academic and overall well-being. Results from both studies consistently indicate that low trait self-control, habitual Facebook checking, and high enjoyment of Facebook use predict almost 40 percent of the variance of using Facebook for procrastination. Moreover, results from Study 2 underline that using Facebook for the irrational delay of important tasks increases students’ academic stress levels and contributes to the negative well-being effects of Facebook use beyond the academic domain. The implications of investigating procrastination as a specific pattern of uncontrolled and dysfunctional media use are discussed with regard to research on the uses and effects of ubiquitous online media.     

Social networks’ unnoticed influence on body image in Spanish university students

The influence of advertising on social networks and its effect on young people’s self-image has been studied. This study first explored the frequency of published videos reposted on social networks using different Application Programming Interfaces as search engines. The study also implemented self-valuation surveys assessed by experts and distributed among mental health professionals who assessed the influence of these social networks. Finally, the survey was designed regarding social networks and body assessment and distributed among Córdoba university students (N = 328). The majority of health professionals concluded that there is an elevated influence of social networks on eating disorders, assessing advertising as a risk factor with a value of 4.60 out of 5. Young people’s perceptions of their body image indicate that women’s degree of satisfaction is highly correlated with the frequency of their connections to social networks, with the body image those women present and with the effect of advertising. Conversely, this high correlation and influence does not exist in men.     

大学院校中的核心文本——柏拉图的《斐德罗篇》与孔子的《论语》

本文包括四个主题：美国过去25年通识教育模式及其演变的主要研究结果;这些变动的原因;九个中亚大学学院在构建核心文本计划方面的合作;什么是核心文本.作者以柏拉图的《斐德罗篇》与孔子的《论语》两门经典的讲授为例,阐明核心文本是一种世界经典或具有重大文化意义的文本.它教导学生处处思考和感受人类关心的那些具有深刻意涵和基础性的事物,跨越众多的学科、文明和时代.其实施的基本环境是教师合作.