Hemingway's works have sometimes been read as an essentially negative commentary on a modern world filled with sterility,failure and death.Yet such a nihilistic vision is repeatedly modified by Hemingway's aff...Hemingway's works have sometimes been read as an essentially negative commentary on a modern world filled with sterility,failure and death.Yet such a nihilistic vision is repeatedly modified by Hemingway's affirmative assertion of the possibility of living with style and courage.Nihility in Hemingway's works is primarily expressed in three forms:a) consciousness of death;b) consciousness of pains;c) consciousness of fantasies.It firstly comes from his life experiences,and then it is closely connected with his living environment and ages.Nihility makes notable impact on his creation.展开更多
Nihility material is a medium whose relative permittivity and permeability tend to zero simultaneously. In this work, comparing with the scattering properties of perfect nihility nanoparticles （made from nihility mat...Nihility material is a medium whose relative permittivity and permeability tend to zero simultaneously. In this work, comparing with the scattering properties of perfect nihility nanoparticles （made from nihility material）, we provide an optimization design of electromagnetic nihility nanoparticles, which is a coated hybrid nanosphere constituted by commutative c-negative （ENG） and μ-negative （MNG） media. Compared to a single ENG or MNG nanosphere, it is found that the total and back scattering spectra of coated hybrid nanospheres are much closer to those of perfect nihility nanospheres. Moreover, it is observed that the scattered electromagnetic field distribution of coated hybrid nanospheres is identical to that of perfect nihility nanospheres. These results indicate that the combination of commutative ENG and MNG media can constitute a composite structure which gives the closest approximation of electromagnetic scattering of perfect nihility nanospheres in a wide frequency range.展开更多
Currently domestic researches on urban imago space concentrate in a few cities that lie in the advanced region, such as Beijing, Guangzhou, Wuhan, etc., but in so far as those cities that lie in the northwest inland r...Currently domestic researches on urban imago space concentrate in a few cities that lie in the advanced region, such as Beijing, Guangzhou, Wuhan, etc., but in so far as those cities that lie in the northwest inland region, the research of this aspect is still few. In order to supplement a special example to the urban imago space theory and to validate former theory, this article studied the Lanzhou urban imago space. During the course of researching, authors adopted some investigating methods, such as visiting on the spot, photograph identification method and sketch map identification method etc. Using investigated data, this paper made an elementary research on urban imago space of Lanzhou, which is a typical valley city in the western China. The result of study indicated that the urban imago space of Lanzhou takes Xiguan Cross as its center (Lanzhou involves four districts of Chengguan, Qilihe, Anning and Xigu). In the process of recognition of urban imago space, the Huanghe (Yellow) River and mountains beside the city are the dominant factors and the main nodes of cognition. So the urban imago space of Lanzhou is quite different from that of plain cities. Interviewee did well in the spatial structure map, which was made up of mountainous land, river and main trunk roads,the group structure took profound impression on people.展开更多
Starting from optical nihility media (ONM),we design several intriguing devices with transformation optics method in two dimensions,such as a wave splitter,a concave lens,a field rotator,a concentrator,and an invisibi...Starting from optical nihility media (ONM),we design several intriguing devices with transformation optics method in two dimensions,such as a wave splitter,a concave lens,a field rotator,a concentrator,and an invisibility cloak.Though the extreme anisotropic property of ONM hinders the fabrication of these devices.We demonstrate that those devices could be effectively realized by simplified materials with Fabry-Pérot resonances (FPs) at discrete frequencies.Moreover,we propose a reduced version of simplified materials with FPs to construct a concentrator and a rotator,which is feasible in experimental fabrications.The simulations of total scattering cross-sections confirm their functionalities.展开更多
文摘Hemingway's works have sometimes been read as an essentially negative commentary on a modern world filled with sterility,failure and death.Yet such a nihilistic vision is repeatedly modified by Hemingway's affirmative assertion of the possibility of living with style and courage.Nihility in Hemingway's works is primarily expressed in three forms:a) consciousness of death;b) consciousness of pains;c) consciousness of fantasies.It firstly comes from his life experiences,and then it is closely connected with his living environment and ages.Nihility makes notable impact on his creation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11174222 and 91230203
文摘Nihility material is a medium whose relative permittivity and permeability tend to zero simultaneously. In this work, comparing with the scattering properties of perfect nihility nanoparticles （made from nihility material）, we provide an optimization design of electromagnetic nihility nanoparticles, which is a coated hybrid nanosphere constituted by commutative c-negative （ENG） and μ-negative （MNG） media. Compared to a single ENG or MNG nanosphere, it is found that the total and back scattering spectra of coated hybrid nanospheres are much closer to those of perfect nihility nanospheres. Moreover, it is observed that the scattered electromagnetic field distribution of coated hybrid nanospheres is identical to that of perfect nihility nanospheres. These results indicate that the combination of commutative ENG and MNG media can constitute a composite structure which gives the closest approximation of electromagnetic scattering of perfect nihility nanospheres in a wide frequency range.
基金Under the auspices of the National Natural Science Foundation of China (No. 40201016) and the National Social Science Foundation of China (No.02BJL033)
文摘Currently domestic researches on urban imago space concentrate in a few cities that lie in the advanced region, such as Beijing, Guangzhou, Wuhan, etc., but in so far as those cities that lie in the northwest inland region, the research of this aspect is still few. In order to supplement a special example to the urban imago space theory and to validate former theory, this article studied the Lanzhou urban imago space. During the course of researching, authors adopted some investigating methods, such as visiting on the spot, photograph identification method and sketch map identification method etc. Using investigated data, this paper made an elementary research on urban imago space of Lanzhou, which is a typical valley city in the western China. The result of study indicated that the urban imago space of Lanzhou takes Xiguan Cross as its center (Lanzhou involves four districts of Chengguan, Qilihe, Anning and Xigu). In the process of recognition of urban imago space, the Huanghe (Yellow) River and mountains beside the city are the dominant factors and the main nodes of cognition. So the urban imago space of Lanzhou is quite different from that of plain cities. Interviewee did well in the spatial structure map, which was made up of mountainous land, river and main trunk roads,the group structure took profound impression on people.
基金supported by the National Natural Science Foundation of China for Excellent Young Scientists (Grant No.61322504)the National Basic Research Program of China (Grant No.2013CB035901)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No.20720170015)the National Natural Science Foundation of China (Grants Nos.51779224, 51579221,51279180,61705200, and 11874311).
文摘Starting from optical nihility media (ONM),we design several intriguing devices with transformation optics method in two dimensions,such as a wave splitter,a concave lens,a field rotator,a concentrator,and an invisibility cloak.Though the extreme anisotropic property of ONM hinders the fabrication of these devices.We demonstrate that those devices could be effectively realized by simplified materials with Fabry-Pérot resonances (FPs) at discrete frequencies.Moreover,we propose a reduced version of simplified materials with FPs to construct a concentrator and a rotator,which is feasible in experimental fabrications.The simulations of total scattering cross-sections confirm their functionalities.
