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111.
本文从降低供应风险的角度,对2020年前我国原油进口结构的优化路径进行了定量分析。并且为应对伊朗原油出口的减少提出了数量化的政策建议。研究结论显示,由于我国对世界原油的需求将会持续旺盛,在未来几年内,我国需要大量增加从俄罗斯、科威特、阿联酋、卡塔尔、墨西哥及阿尔及利亚等传统产油国的进口,同时减少对沙特阿拉伯、安哥拉、苏丹和伊朗的原油依赖。从未来原油进口的地区分布上看,中东地区依然是我国原油进口的主要来源地,同时也是供应风险最大的地区。为应对伊朗石油禁运,我国应该增加从加拿大、墨西哥、尼日利亚和卡塔尔等国的原油进口来弥补供应缺口,并满足国内快速增长的原油消费需求。  相似文献   
112.
We present a 91 MHz surface acoustic wave resonator with integrated microfluidics that includes a flow focus, an expansion region, and a binning region in order to manipulate particle trajectories. We demonstrate the ability to change the position of the acoustic nodes by varying the electronic phase of one of the transducers relative to the other in a pseudo-static manner. The measurements were performed at room temperature with 3 μm diameter latex beads dispersed in a water-based solution. We demonstrate the dependence of nodal position on pseudo-static phase and show simultaneous control of 9 bead streams with spatial control of −0.058 μm/deg ± 0.001 μm/deg. As a consequence of changing the position of bead streams perpendicular to their flow direction, we also show that the integrated acoustic-microfluidic device can be used to change the trajectory of a bead stream towards a selected bin with an angular control of 0.008 deg/deg ± 0.000(2) deg/deg.  相似文献   
113.
Concept maps are proposed as an alternative tool for evaluation in higher education and examples of concept maps, drawn by college students performing evaluation tasks, are presented in the areas of physics and literature.  相似文献   
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The research undertaken for this article aims to analyse the correspondence between perceived employability and the actual national employment rate among Italian students and graduates undertaking different courses in a large Italian university. Data were collected through a cross-sectional survey of 2087 students in 19 faculties, and compared with the national indicators of employment rate for each faculty. Using faculty as unit of analysis, the results indicated a significant correlation between participants’ perceived employability and national employment rate. This trend was similar for both genders. However, the results showed a difference between bachelor’s and master’s degrees: the correlation between perceived and actual employability was not significant among bachelor’s participants while it remained significant among master’s participants. The results suggest that graduates are only partially aware of their possibility to enter the labour market and this, in turn, highlights that universities have only partially met the goal to increase awareness about the chances of finding a job among students and graduates.  相似文献   
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This study investigated relationships between career adaptability and personality and pathological traits using the network analysis approach. We administered CAAS, BFI-2-S, and IDCP-2 to 630 working adults. We observed positive associations between personality and career adaptability and negative associations between pathological traits and career adaptability. This paper contributes to the understanding of the associations between career adaptability and Big Five personality traits and pathological traits. We found stronger associations between career adaptability and personality traits as compared to pathological traits. Our findings suggest that Neuroticism and Conscientiousness contribute more to adaptation to professional development tasks than do pathological traits.

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118.
Evolution is considered an essential topic that brings to school a broader perspective of natural phenomena and of the nature of science. Most if not all research has shown that the result of the teaching of evolutionary theories is not positive in different parts of the world. Some have attributed the poor understanding shown by students to teaching style or to students' cognitive abilities. This article reports results of interviews and tests carried out with students after they had been taught the topic of evolution. By adopting a sociocultural perspective, before terming students' views “misconceptions,” attention was given to several different ways Charles Darwin's theories have been re-interpreted by well-known scholars and offered to the public. I have analyzed the approaches taken by Emanuel Radl (1873-1942), John C. Greene, Robert Maxwell Young, and Ernst Mayr to assess the diverse ways Darwinism has been conceived. Attention was also given to the presentation of this controversial knowledge to the public in two major popular books written by respected scientists, Huxley and Kettlewell's Darwin and His World (1975) and Richard Dawkins' more recent The Blind Watchmaker (1989). These analyses revealed remarkable differences between what was written in Downe (Kent) a hundred years ago and what was heard at Sao Paulo (Brazil) nowadays. Students show very poor understanding of evolutionary theories. Their conceptions reveal evolution has been primarily related to the human species. Its meaning is understood as similar to progress, growth, multiplication, and improvement. Biological and cultural evolution are not clearly distinguished. Competition is misunderstood as pure violence, sometimes inevitable, and adaptation is considered an individual process that occurs during the organism's life span. Educational change may not depend just on teaching style and students' cognitive abilities. Modification of factual knowledge and epistemological gaps may be the result of a process of social reconceptualization of knowledge offered to students.  相似文献   
119.
John Walsh's research on electric fish, carried out between 1772 and 1775, proved fundamental for demonstrating that electricity might be involved in animal physiology, and, moreover, in favouring a period of great progress in both the physiology and physics of electrical phenomena. However, Walsh is hardly known to modern neuroscientists and is largely neglected by science historians also. One of the reasons for this neglect is that he never published his 'crucial experiment', that is the production of a spark from a discharge of the electric eel.  相似文献   
120.
Currently, libraries and other information services are facing new professional challenges in relation to digitization policies and orphan works after the publication of European Directive 2012/28/EU on certain permitted uses of orphan works and Spanish Royal Decree 224/2016. This paper aims to analyse how Spanish library and information centres specialising in theatre and performing arts meet users' textual and non-textual information needs, by respecting copyright issues and being involved in a dynamic and digital environment. For this purpose, an online questionnaire, which was used as a methodological tool, was sent to library directors in February 2018. At the same time, some research questions based on orphan works and digitisation approaches are discussed in the paper, specifically in reference to graphic and audiovisual materials.  相似文献   
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