One hundred years of Weyl’s (unfinished) unified field theory

In 1918, H. Weyl proposed a unified theory of gravity and electromagnetism based on a generalization of Riemannian geometry. In spite of its elegance and beauty, a serious objection was raised by Einstein, who argued that Weyl’s theory was not suitable as a physical theory . According to Einstein, the theory led to the prediction of a “second clock effect”, which has not been observed by experiments as yet. We briefly revisit this point and argue that a preliminary discussion on the very notion of proper time is needed in order to consider Einstein’s critical point of view. We also point out that Weyl theory is basically incomplete in its original version and its completion may lead to a rich and interesting new approach to gravity.     

On the life-habits and developmental stages of Nidomyia cana Papp (Diptera,Borboropsidae)

Eggs, second and third instar larvae of the enigmatic species Nidomyia cana, which was discovered most recently from the nests of raptorial birds in southern Hungary, are described. Both egg and larvae show peculiarities among the so-called heleomyzoid flies. Larvae were found in wet vegetable material (mostly pieces of poplar bark) of a buzzard nest and their shape is of a saprophagous type. Females are macro-oviparous, with a maximum of 15 to 17 eggs laid in one batch. Adults live mostly on the surface the of the nest, they copulate there, and they find shelter in the nest itself. No direct contact with adults or nestlings within the nest was observed. It is suggested that overwintering occurs as pupae (pharate adults) underground, beneath the nest. However, if N. cana lives exclusively in the nests of raptors, adults would have difficulties in finding a new nest, and it is probable that they are transferred to new nests attached to the birds.     

影响外语习得的学习者因素

外语习得的研究应主要研究成功的学习者:考查学习者的学习动机、学习机会和学习能力三方面。动机是学习者从事外语学习的根据,是影响外语习得的最重要因素,多数外语学习者的动机是交际需求和对外语国家态度综合作用的结果。外部环境提供的学习机会中,正规教学并非必须,语言材料也应当适合学习者的自然习得机制。学习能力方面主要分析语言认知的一些特点,理清个性及年龄对外语习得的影响,并归纳成功学习者的一些策略。对学习者因素的分析,可为调整我们外语教学的方式方法提供新的思路。     

商业银行企业并购业务的绩效评价

商业银行传统的盈利和发展模式在近几年受到利率市场化、金融脱媒等外部环境的影响,为了拓展业务、实现商业银行的业务转型,并购业务等投行业务成为商业银行业绩增长的新领域。本文选取中国银行、中国农业银行、中国建设银行、中信银行、中国民生银行、兴业银行等8家商业银行以及中信证券、华泰联合证券、国泰君安证券等8家投行机构,对这16家机构2010年至2015年并购业务的技术效率、纯技术效率、规模效率等进行测算。结果表明,我国商业银行并购业务虽然近几年发展迅速,但仍存在一定的问题,规模较小,产出效率较低,未来仍有比较大的发展空间。     

论无声语言在演讲中的重要性及运用

无声语言是演讲中使用最多、最普遍,作用也最大的辅助性工具,它与语意、有声语言一道构成了演讲意义表达体系,并且有独立、直观的审美价值。本文就演讲中如何准确而得体地运用无声语言来表意表达了一些意见和建议。