25,881 research outputs found
Yang-Mills Connections on Nonorientable Surfaces
In "The Yang-Mills equations over Riemann surfaces", Atiyah and Bott studied
Yang-Mills functional over a Riemann surface from the point of view of Morse
theory. We generalize their study to all closed, compact, connected, possibly
nonorientable surfaces. We introduce the notion of "super central extension" of
the fundamental group of a surface. It is the central extension when the
surface is orientable. We establish a precise correspondence between Yang-Mills
connections and representations of super central extension. Knowing this exact
correspondence, we work mainly at the level of representation varieties which
are finite dimensional instead of the level of strata which are infinite
dimensional.Comment: 45 pages, 1 figur
High-sensitivity Fiber Bragg grating temperature sensor at high temperature
A method of making full use of the durable strain which fiber Bragg grating (FBG) can undertake is presented, which hugely improves the sensitivities of FBG temperature sensors at high temperature. When a sensor is manufactured at room temperature, its FBG should be given a pre-relaxing length according to the temperature it is asked to measure; once the temperature rise to the asked one, its FBG starts to be stretched and it starts to work with high sensitivity. The relationship between the pre-relaxing length and the working temperature is analyzed. In experiments, when the pre-relaxing lengths are 0.2mm、0.5mm、0.6mm, the working temperatures rise 25℃、50℃、61℃, respectively, and the sensitivities are almost the same (675pm/℃). The facts that the experimental results agree well with the theoretical analyses verify this method’s validity
The Impact of Deep Brain Stimulation on the Cognitive Ability of Patients with Parkinson Disease
Deep Brain Stimulation, especially STN-DBS, is one of the most prevalent treatments for the Parkinson’s Disease. Previous researches already showed its positive effects on the general conditions of the patients but lack evaluation of its influence on the cognitive ability of the patients. A comparison in the effect of DBS and surgical lesioning procedures can determine DBS’s influence on the quality of life and confirm whether it is the most optimal treatment. This proposal reviewed previous researches about the influence of STN-DBS and proposed a study on its influence of patients’ cognitive ability
Renewing Strategie Transformation in Asia - Pacific
From introduction: "The year 2005 began with a series of attempts for a strategie new modelling in East
Asia. The US President George Bush has been well into his second term and started
to shape up a new regional strategie environment. In the light of the incessant
Iraqi as well as the North Korean issue, at this moment the US obviously need to
make a more diplomatic effort rather than rely purely on the military superiority in
intemational affairs. This was clearly highlighted by the new Secretary of State,
Condoleezza Rice, at her eonfirmation hearing at the Senate on 18 January, 2005.
She indicated: “we must use American diplomacy to help create a balance of power
in the world that favors freedom. And the time for diplomacy is now.”"(...
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