7,222 research outputs found
The Construction of Touristic Modernity in Xizhou
Tim Oakes’ (1998) concept of touristic modernity accurately describes how the Chinese national discourse surrounding tourism, as both a tool for economic growth and nation-building, has shaped what the local reality has become for many towns and villages in the peripheral regions of China, especially those with large populations of ethnic minorities. Specifically in the Dali Bai Autonomous Region, foreign tourism followed by nostalgia-fueled domestic tourism has transformed Dali into a commercialized tourist destination, which has begun to spill out to other towns around the lake such as Xizhou. Touristic modernity is not, however, a singular homogenous force that culturally and physically transforms a given location overnight; instead, the construction of touristic modernity is a process that involves multiple contributing actors. In Xizhou, where the construction of touristic modernity is in its beginning stages, three main actors who are contributing to this process can be identified: domestic tourists, the Linden Centre, and local people
Light-heavy ion measurements in CR-39 located on the Earth side of LDEF
The azimuthal angle distribution and the charge and energy spectra of selected light-heavy (5 less than or equal to Z less than or equal to 8) stopping particles were measured in a single layer of CR-39 plastic nuclear track detector (PNTD) from the stack of the A0015 experiment located on the Earth-end of the LDEF satellite. The directional incidence of the trapped protons is studied by comparing the azimuthal angle distribution of selected recoils, obtained in the LDEF detectors, to that obtained through calibrations of PNTD's with exposures performed with 200 MeV proton beams from different directions
Expected contribution of the Geopotential Research Mission (GRM) to studies of liquid core fluid dynamics
Finding satisfactory models of the fluid motions at the top of the core is important for delineating what kind of dynamo is in operation, for estimating the heat flux into the base of the mantle, and for forecasting the magnetic field forward in time. Each of these aspects will be discussed
Investigation of geomagnetic field forecasting and fluid dynamics of the core
It was established that the total absolute magnetic flux crossing the core- mantle boundary has been a constant of the core motion for the last 50 years. This provides a scalar constraint that could be added to the geometric modelling procedure. The GSFC 8 8/80 model is being evaluated. The absolute magnetic flux linking the CMB to that model was plotted as a function of time during the span covered by the data, and increasing truncation level. The inclusion of the standard error of each Gauss coefficient derived from the statistics of fit in the GSFC 9/80 model is useful. The magnitude and sense (upwelling or downe welling) of vertical fluid motion adjacent to the core-mantle boundary was calculated using the model. Standard errors were found to be sufficiently small at all but one or two of the 40 or more critical points of B sub r. They do not nearly overlap the value gamma u/gamma r = 0. It is concluded that the core is upwelling and downwelling at an observationally detectable level
Investigation of geomagnetic field forecasting and fluid dynamics of the core
The magnetic determination of the depth of the core-mantle boundary using MAGSAT data is discussed. Refinements to the approach of using the pole-strength of Earth to evaluate the radius of the Earth's core-mantle boundary are reported. The downward extrapolation through the electrically conducting mantle was reviewed. Estimates of an upper bound for the time required for Earth's liquid core to overturn completely are presented. High order analytic approximations to the unsigned magnetic flux crossing the Earth's surface are also presented
Data use investigation for the magnetic field satellite (MAGSAT) mission: Geomagnetic field forecasting and fluid dynamics of the core
MAGSAT data were used to construct a variety of spherical harmonic models of the main geomagnetic field emanating from Earth's liquid core at poch 1980. These models were used to: (1) accurately determine the radius of Earth's core by a magnetic method, (2) calculate estimates, of the long-term ange of variation of geomagnetic Gauss coefficients; (3) establish a preferred truncation level for current spherical harmonic models of the main geomagnetic field from the core; (4) evaluate a method for taking account of electrical conduction in the mantle when the magnetic field is downward continued to the core-mantle boundary; and (5) establish that upwelling and downwelling of fluid motion at the top of the core is probably detectable, observationally. A fluid dynamics forecast model was not produced because of insufficient data
Investigation of geomagnetic field forecasting and fluid dynamics of the core
Progress in the development, testing, and evaluation of kinematic geomagnetic forecast models and their utility in magnetic prediction of the core-mantle boundary of the Earth and in determination of the core radius is reported. The GFSC 9/80 model, which uses MAGSAT data, was determined to be of high quality
Experiment K-6-24, K-6-25, K-6-26. Radiation dosimetry and spectrometry
Radiation experiments flown by the University of San Francisco on the Cosmos 1887 spacecraft were designed to measure the depth dependence of both total dose and heavy particle flux, dose and dose equivalent, down to very thin shielding. Three experiments were flown and were located both inside and outside the Cosmos 1887 spacecraft. Tissue absorbed dose rates of 264 to 0.028 rad d(-1) under shielding of 0.013 to 3.4 g/sq cm of (7)LiF were found outside the spacecraft and 0.025 rad d(-1) inside. Heavy particle fluxes of 3.43 to 1.03 x 10 to the minus 3rd power cm -2 sub s -1 sub sr -1 under shielding of 0.195 to 1.33 g/sq cm plastic were found outside the spacecraft and 4.25 times 10 to the minus 4th power cm -2 sub s -1 sub sr -1 inside (LET infinity H2O greater than or equal to 4 keV/micron m). The corresponding heavy particle dose equivalent rates outside the spacecraft were 30.8 to 19.8 mrem d(-1) and 11.4 mrem d(-1) inside. The large dose and particle fluxes found at small shielding thicknesses emphasize the importance of these and future measurements at low shielding, for predicting radiation effects on space materials and experiments where shielding is minimal and on astronauts during EVA. The Cosmos 1887 mission contained a variety of international radiobiological investigations to which the measurements apply. The high inclination orbit (62 degrees) of this mission provided a radiation environment which is seldom available to U.S. investigators. The radiation measurements will be compared with those of other research groups and also with those performed on the Shuttle, and will be used to refine computer models employed to calculate radiation exposures on other spacecraft, including the Space Station
Fast sampling control of a class of differential linear repetitive processes
Repetitive processes are a distinct class of 2D linear systems of practical and theoretical interest. Most of the available control theory for them is for the case of linear dynamics and focuses on systems theoretic properties such as stability and controllability/observability. This paper uses an extension of standard, or 1D, feedback control schemes to control a physically relevant sub-class of these processes
Stability Tests for a Class of 2D Continuous-Discrete Linear Systems with Dynamic Boundary Conditions
Repetitive processes are a distinct class of 2D systems of both practical and theoretical interest. Their essential characteristic is repeated sweeps, termed passes, through a set of dynamics defined over a finite duration with explicit interaction between the outputs, or pass profiles, produced as the system evolves. Experience has shown that these processes cannot be studied/controlled by direct application of existing theory (in all but a few very restrictive special cases). This fact, and the growing list of applications areas, has prompted an on-going research programme into the development of a 'mature' systems theory for these processes for onward translation into reliable generally applicable controller design algorithms. This paper develops stability tests for a sub-class of so-called differential linear repetitive processes in the presence of a general set of initial conditions, where it is known that the structure of these conditions is critical to their stability properties
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