谈高职英语专业学生英语演讲能力的培养

社会经济发展越来越要求高职英语专业学生拥有良好的英语演讲能力。培养高职英语专业学生的英语演讲能力,应充分利用课堂教学阵地和校园文化平台,从提高英语语言水平、强化演讲心理素质、增强创新思辨能力三个方面着手。     

2000—2015年中国铜废碎料贸易及效益风险分析

铜是具有重要战略意义的关键金属。中国长期以来进口“六类废杂铜”和“七类废杂铜”两种废碎料来冶炼再生铜。本文基于海关贸易和有色金属工业统计数据,利用物质流分析和生命周期评价方法研究了铜废碎料贸易的资源、环境和经济效益以及环境与健康风险。结果显示：①2000—2015年,中国累计进口铜废碎料实物量6680万t,其中含金属铜约2000万t,占同期国内再生铜累计产量的56%;②相比利用铜矿石生产精炼铜,利用进口铜废碎料生产再生铜在非生物性资源消耗、温室效应和人体毒性等方面减少了一系列环境影响,同时累计节约铜矿山投资成本约580亿美元。然而,进口的“七类废杂铜”在带来资源效益的同时也造成严重的区域性环境与健康风险：一是进口低品位铜废碎料中夹杂大量有机物,在拆解和熔炼过程中容易产生二恶英等有毒有害物质;二是部分工业园区和小企业在工艺、技术、空间布局和生产管理等方面的落后引发了局部地区较为严重的环境和健康危害。因此,建议辩证和全面地认识铜废碎料进口带来的效益和风险,在坚决禁止进口“以回收铜为主的废电机、电线、电缆和五金电器”这些“七类废杂铜”的同时,继续利用进口“六类废杂铜”作为重要的铜资源,以降低中国对原生铜矿石的依赖以及造成的采矿和原矿冶炼阶段的环境影响。     

微型化学实验测定化学反应速度常数

用微型化学实验和常规化学实验测定化学反应速率常数,在误差允许范围内比较微型化学实验的优越性.     

对单分子反应机理的探索

化学动力学的主要问题之一,是对单分子反应一级动力学作出解释.以Lindemann历程为基础,阐明单分子反应机理的动力学特征,并指出只有在整个反应是一级和三级混合在一起的降变过程,才是真正的Lindemann历程.     

NiCo_2O_4纳米结构阵列的水热合成与氧析出特性研究

钴酸镍纳米材料具有良好的电催化氧析出反应(Oxygen Evolution Reaction,OER)活性,是一种很有发展潜力的非贵金属电催化材料。文章以碳纤维纸为基底,采用水热合成的方法对纳米结构钴酸镍的生长进行了系统的研究,分别考察了生长温度、前驱体浓度和配比、生长时间对产物的形貌、尺寸、物相结构、OER电化学性能的影响,通过对比分析后发现在生长温度100℃、生长时间5h、镍钴比为2:1时所获得的多孔片状钴酸镍纳米结构具有最佳的OER特性。     

Evaluation of adverse drug reaction formatting in drug information mobile phone applications

Objective:To evaluate the differences in presentation (formatting) of adverse drug reaction (ADR) information within drug monographs in commonly used drug information (DI) mobile device applications.Methods:A cross-sectional analysis of ADR formatting of twenty commonly prescribed oral medications within seven DI mobile applications was performed. Databases were assessed for ADR information, including presence of placebo comparisons, severity of ADR, onset of ADR, formatting of ADRs in percentile (quantitative) format or qualitative format, whether references were used to cite information, and whether ADRs are grouped by organ system. Data was collected by two study investigators and discrepancies were resolved via consensus.Results:The seven DI mobile applications varied significantly on every analyzed ADR variable with the exception of ADR onset, which was absent in all databases. Significant differences were found for variables known to impact clinical judgment such as placebo comparisons and qualitative versus quantitative formatting. Placebo comparisons were most common among monographs in Lexicomp (30%) but were absent among monographs within other applications. Quantitative information was commonly used in most databases but was absent in Epocrates. Qualitative formatting was present in all Epocrates and Micromedex applications but absent in the majority of other applications. Substantial variations were also found in severity and grouping information.Conclusion:Substantial variation in ADR formatting exists among the most common DI mobile applications. These differences may translate into alternative interpretations of medical information and thus impact clinical judgment. Health care librarians and clinicians should consider ADR formatting when choosing between DI applications.     

Physiological responses in different intensities of resistance exercise – Critical load and the effects of aging process

Aim was to identify critical load (CL) in young and elderly apparently healthy male cohorts. To contrast the metabolic, cardiovascular and perceptual responses on CL according to age. We evaluated 12 young (23 ± 3 years) and 10 elderly (70 ± 2 years) apparently healthy active males, who underwent: (1) 1 repetition maximum (1RM) test on a 45° Leg Press; (2) on different days, three high-intensity resistance exercise constant load tests (60%, 75% and 90% 1RM) until fatigue (Tlim). Absolute values of both the CL asymptote and curvature constant (kg) were significantly lower in elderly subjects (P < 0.05). In contrast, elderly subjects demonstrated a significantly higher number of repetitions at CL when compared with young subjects (P < 0.05). As expected, oxygen uptake (VO₂) and heart rate (HR) during maximal aerobic exercise testing were significantly reduced in older subjects. However, percent-predicted aerobic capacity were higher in older subjects (P < 0.05). In addition, blood lactate ([La^?]) corrected to Tlim and rating of perceived exertion values were greater in younger subjects at all intensities (P < 0.05). These findings, despite reduced force production in older subjects, endurance-related parameters are well preserved according to age-adjusted percent-predicted values in apparently healthy males.     

In defence of white privilege: physical education teachers’ understandings of their work in culturally diverse schools

Research suggests that physical education (PE) in Western countries is not providing equitable experiences for non-white students. Responsibility for shortcomings has often been ascribed to white PE teachers. Scholars have claimed that teachers lack cultural competence and know little about how physical cultures or health are understood by the young people with whom they work. The objective of this investigation was to investigate this claim and generate an understanding of how white PE teachers in a culturally diverse high school make sense of their work with non-white students. Data with three Swedish teachers of varying experience were produced using semi-structured interviewing. A series of school visits provided a complementary line of data. Four themes emerged from the data. These related to: (1) differences between white and non-white values; (2) the knowledge and dispositions necessary for success in PE; (3) the broad purpose of PE, and; (4) the differences between boys’ and girls’ experiences of PE. Data were interpreted using a Critical Race Theory (CRT) perspective, with the notion of ‘whiteness’ providing a specific analytic concept. The general thesis developed in the second part of the paper is that problems result not from insensitivity or incompetence but from discourses of whiteness in which many teachers live and work. By building on critical research both in general education and physical education literature and by utilizing whiteness as an analytical concept, the investigation shows how three PE teachers draw extensively on the racial discourse of whiteness and how this disadvantages non-white students. The paper is concluded with a consideration of how racial disadvantage could be challenged or disrupted.     

Influence of upright versus time trial cycling position on determination of critical power and W′ in trained cyclists

Body position is known to alter power production and affect cycling performance. The aim of this study was to compare mechanical power output in two riding positions, and to calculate the effects on critical power (CP) and W′ estimates. Seven trained cyclists completed three peak power output efforts and three fixed-duration trial (3-, 5- and 12-min) riding with their hands on the brake lever hoods (BLH), or in a time trial position (TTP). A repeated-measures analysis of variance showed that mean power output during the 5-min trial was significantly different between BLH and TTP positions, resulting in a significantly lower estimate of CP, but not W′, for the TTP trial. In addition, TTP decreased the performance during each trial and increased the percentage difference between BLH and TTP with greater trial duration. There were no differences in pedal cadence or heart rate during the 3-min trial; however, TTP results for the 12-min trial showed a significant fall in pedal cadence and a significant rise in heart rate. The findings suggest that cycling position affects power output and influences consequent CP values. Therefore, cyclists and coaches should consider the cycling position used when calculating CP.     

基于正交设计葡萄废弃物基生物活化炭的制备及其吸附性能

以葡萄皮为原材料,用限氧热解法制备生物炭.通过设计3因素3水平的正交实验,选择出最佳的活化条件进行活化,得到活化生物炭用于吸附实验.考察反应物初始浓度、反应温度和接触时间对吸附的影响规律,并进行分析.由动力学拟合结果,可以得出葡萄皮基生物炭对甲基橙的吸附过程用准二级动力学方程较好拟合,说明生物炭对甲基橙的吸附不是单一的...