397 research outputs found
Reading Song-Ming Records on the Pre-colonial History of the Philippines
Chinese records of the Song-Ming period provide the context necessary for our understanding of the history of the pre-colonial Philippines. Rulers of chiefdoms in the region employed unique methods and formed far-reaching networks when trading with each other and with China. Trade was one of their ways to build domestic power structure and to establish their positions relative to one another in regional politics. They also organized missions to seek Chinese recognition of these power relations
RoomâTemperature Transport Properties of Graphene with Defects Derived from OxoâGraphene
In recent years, graphene oxide has been considered as a soluble precursor of graphene for electronic applications. However, the performance lags behind that of graphene due to lattice defects. Here, the relation between the density of defects in the range of 0.2â% and 1.5â% and the transport properties is quantitatively studied. Therefore, the related flakes of monolayers of graphene were prepared from oxoâfunctionalized graphene (oxoâG). The morphologic structure of oxoâG was imaged by atomic force microscopy (AFM) and scanning tunneling microscopy (STM). Fieldâeffect mobility values were determined to range between 0.3â
cm2âVâ1âsâ1 and 33.2â
cm2âVâ1âsâ1, which were inversely proportional to the density of defects. These results provide the first quantitative description of the density of defects and transport properties, which plays an important role for potential applications
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The Reconciliation of Reason and Faith in Gothic Period of Medieval Europe
Investigation of electrical properties of monolayer oxo-functionalized graphene-based two-dimensional materials
Chemically modified graphene, such as oxo-functionalized graphene (oxo-G), has received considerable interests for electronic, optoelectronic, biological and chemical sensing applications due to its tunable bandgap, diverse luminescence behaviors and the ability to modify carbon atoms covalently and non-covalently. In contrast to pristine graphene with carbon arranged in a two-dimensional hexagonal lattice, oxo-G consists of abundant sp3 hybridized carbon atoms due to covalent bonds of carbon with oxo-groups, mainly hydroxyl and epoxy groups. The existence of surface oxo-groups has profound impacts on improving its hydrophilicity, chemical reactivity, catalytic activity, and optical properties, while the effect is detrimental for the electrical conductivity. The defunctionalization of oxo-G by chemical reduction or thermal annealing leads to a certain type of graphene (G), termed as reduced oxo-G (r-oxo-G).
So far, the majority of studies on oxo-G based materials focused on optimizing preparation and reduction methods, understanding preparation protocols and reduction mechanism, and various applications. Deep knowledge about electrical properties and the chemical structure of the reduced oxo-G (r-oxo-G) based materials themselves is still lacking. In detail, no systematic study involves room-temperature transport perfromances of monolayer graphene derived from oxo-G. Currently reported mobility or resistance values were determined from multilayer thin films of the r-oxo-G related materials with unknown thickness and differential quality. It does not make sense for comparing these results obtained from non-standard transport measurements and test conditions. In addition, the structure evolution of the oxo-G remains ambiguous during the thermal annealing treatment.
The thesis presented here is dedicated to study the problems mentioned above by using oxo-G and r-oxo-G with various densities of defects as main research objects. Firstly, substrate effects on the room-temperature electrical transport of monolayer reduced oxo-G with defects of about 0.5% (0.5%G) were studied. The results demonstrated that the monolayer 0.5%G on a hexagonal boron nitride (h-BN) substrate exhibited lighter p-doping and smaller hysteresis than on a SiO2 substrate due to less trapped molecules induced by the h-BN buffer layer. Then, the relation between densities of defects in the range of 0.2% and 1.5% and transport properties was quantitatively investigated. The defects divided graphene domains into isolated small islands with a distance between nearest two defects lower than 3 nm. Therefore, the mobility values of charge carriers of graphene with densities of defects between 0.2% and 1.5%, changed from 0.3 cm2 Vâ1 sâ1 and 33.2 cm2 Vâ1 sâ1. Finally, the structural evolution and electrical performances of the monolayer oxo-G during the thermal decomposition process were studied. The defect structures including holes and bilayer C-C sp3-patches induced by thermal disproportion of the monolayer oxo-G were demonstrated. Scanning tunnelling spectroscopy revealed a semiconducting behavior of the nanometer-sized sp3 bilayer structures with a bandgap of ~ 0.4 eV. These fundamental studies can help to better understand oxo-functionalized graphene derivatives and promote more extensive applications
A Sartrean reading of American artists : Walker Percy, Edward Hopper, and Mike Nichols 1940-1970.
Jean-Paul Sartre\u27s existential philosophy concerns the free human individual, particularly his possibilities to continuously create his own identities. Human existence is never defined by objects, and he is only determined by his own actions. As long as he is alive. he possesses this freedom and never ceases to project himself into the future. The undefined nature of human existence is conceived as human beings on the move. A study of this sense as it is revealed in the art helps us feel and embrace the fundamental core of Sartre\u27s thought. In this dissertation, I examine selected works of American novelist Walker Percy, painter Edward Hopper, and director Mike Nichols with special attention to the depiction of the human being as a conscious being who is keeping a sense of wonder so as to stave off the everydayness, who is imagining a new world into the unknown so as to demonstrate his strong interiority, and who is searching for a true life so as to exhibit his authenticity. Binx in Percy\u27s The Moviegoer, women in solitude in Hopper\u27s oil paintings, and Ben in Nichols\u27 The Graduate are reflecting the sense of human beings on the move in graceful manner. My reading of artists\u27 presentations of human consciousness links the chapters. When the human being is conscious of his existence, he is able to transcend himself, and he lives in hope. My understanding of the concepts such as being-in-itself, being-for-itself, bad faith, and authenticity are primarily formed in Sartre\u27s Being and Nothingness and his Existentialism Is a Humanism
Constructing Word-Context-Coupled Space Aligned with Associative Knowledge Relations for Interpretable Language Modeling
As the foundation of current natural language processing methods, pre-trained
language model has achieved excellent performance. However, the black-box
structure of the deep neural network in pre-trained language models seriously
limits the interpretability of the language modeling process. After revisiting
the coupled requirement of deep neural representation and semantics logic of
language modeling, a Word-Context-Coupled Space (W2CSpace) is proposed by
introducing the alignment processing between uninterpretable neural
representation and interpretable statistical logic. Moreover, a clustering
process is also designed to connect the word- and context-level semantics.
Specifically, an associative knowledge network (AKN), considered interpretable
statistical logic, is introduced in the alignment process for word-level
semantics. Furthermore, the context-relative distance is employed as the
semantic feature for the downstream classifier, which is greatly different from
the current uninterpretable semantic representations of pre-trained models. Our
experiments for performance evaluation and interpretable analysis are executed
on several types of datasets, including SIGHAN, Weibo, and ChnSenti. Wherein a
novel evaluation strategy for the interpretability of machine learning models
is first proposed. According to the experimental results, our language model
can achieve better performance and highly credible interpretable ability
compared to related state-of-the-art methods.Comment: Accepted at ACL 2023, Finding
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