6,170 research outputs found
Interdimensional degeneracies for a quantum three-body system in D dimensions
A new approach is developed to derive the complete spectrum of exact interdimensional degeneracies for a quantum three-body system in D-dimensions. The new method gives a generalization of previous methods
Predicting Urban Medical Services Demand in China: An Improved Grey Markov Chain Model by Taylor Approximation
The sharp increase of the aging population has raised the pressure on the current limited medical resources in China. To better allocate resources, a more accurate prediction on medical service demand is very urgently needed. This study aims to improve the prediction on medical services demand in China. To achieve this aim, the study combines Taylor Approximation into the Grey Markov Chain model, and develops a new model named Taylor-Markov Chain GM (1,1) (T-MCGM (1,1)). The new model has been tested by adopting the historical data, which includes the medical service on treatment of diabetes, heart disease, and cerebrovascular disease from 1997 to 2015 in China. The model provides a predication on medical service demand of these three types of disease up to 2022. The results reveal an enormous growth of urban medical service demand in the future. The findings provide practical implications for the Health Administrative Department to allocate medical resources, and help hospitals to manage investments on medical facilities
An Energy Analysis of the Catalytic Combustion Burner
The gas boilers of conventional flame always produce varying degrees of combustion products NOx and CO, which pollute the environment and waste energy. As a new way of combustion, catalytic combustion breaks the flammable limits of conventional flame combustion, and realizes the combustion of ultra-natural gas/air mixture under the flammable limits. Its combustion efficiency is higher, which improves the ratio of energy utilization. Applying the catalytic combustion to gas boilers could solve the gas boilers' lower combustion efficiency, and achieve energy savings. On the basis of the catalytic combustion burner, the catalytic combustion burner was designed according to the catalytic combustion and water heaters. In this paper, we analyzed the heat loss and thermal efficiency of the catalytic combustion burner, and compared it to that of flame combustion boilers. The results showed that catalytic combustion burner ?'s heat loss is not so high as originally considered, and its pollutant emissions are lower
Quantum three-body system in D dimensions
The independent eigenstates of the total orbital angular momentum operators
for a three-body system in an arbitrary D-dimensional space are presented by
the method of group theory. The Schr\"{o}dinger equation is reduced to the
generalized radial equations satisfied by the generalized radial functions with
a given total orbital angular momentum denoted by a Young diagram
for the SO(D) group. Only three internal variables are
involved in the functions and equations. The number of both the functions and
the equations for the given angular momentum is finite and equal to
.Comment: 16 pages, no figure, RevTex, Accepted by J. Math. Phy
Spatial and seasonal variability of PM<sub>2.5</sub> acidity at two Chinese megacities: insights into the formation of secondary inorganic aerosols
Aerosol acidity is one of the most important parameters influencing atmospheric chemistry and physics. Based on continuous field observations from January 2005 to May 2006 and thermodynamic modeling, we investigated the spatial and seasonal variations in PM<sub>2.5</sub> acidity in two megacities in China, Beijing and Chongqing. Spatially, PM<sub>2.5</sub> was generally more acidic in Chongqing than in Beijing, but a reverse spatial pattern was found within the two cities, with more acidic PM<sub>2.5</sub> at the urban site in Beijing whereas the rural site in Chongqing. Ionic compositions of PM<sub>2.5</sub> revealed that it was the higher concentrations of NO<sub>3</sub><sup>−</sup> at the urban site in Beijing and the lower concentrations of Ca<sup>2+</sup> within the rural site in Chongqing that made their PM<sub>2.5</sub> more acidic. Temporally, PM<sub>2.5</sub> was more acidic in summer and fall than in winter, while in the spring of 2006, the acidity of PM<sub>2.5</sub> was higher in Beijing but lower in Chongqing than that in 2005. These were attributed to the more efficient formation of nitrate relative to sulfate as a result of the influence of Asian desert dust in 2006 in Beijing and the greater wet deposition of ammonium compared to sulfate and nitrate in 2005 in Chongqing. Furthermore, simultaneous increase of PM<sub>2.5</sub> acidity was observed from spring to early summer of 2005 in both cities. This synoptic-scale evolution of PM<sub>2.5</sub> acidity was accompanied by the changes in air masses origins, which were influenced by the movements of a subtropical high over the northwestern Pacific in early summer. Finally, the correlations between [NO<sub>3</sub><sup>−</sup>]/[SO<sub>4</sub><sup>2−</sup>] and [NH<sub>4</sub><sup>+</sup>]/[SO<sub>4</sub><sup>2−</sup>] suggests that under conditions of high aerosol acidity, heterogeneous reactions became one of the major pathways for the formation of nitrate at both cities. These findings provided new insights in our understanding of the spatial and temporal variations in aerosol acidity in Beijing and Chongqing, as well as those reported in other cities in China
Alfvenic Ion Temperature Gradient Activities in a Weak Magnetic Shear Plasma
We report the first experimental evidence of Alfvenic ion temperature
gradient (AITG) modes in HL-2A Ohmic plasmas. A group of oscillations with
kHz and is detected by various diagnostics in high-density
Ohmic regimes. They appear in the plasmas with peaked density profiles and weak
magnetic shear, which indicates that corresponding instabilities are excited by
pressure gradients. The time trace of the fluctuation spectrogram can be either
a frequency staircase, with different modes excited at different times or
multiple modes may simultaneously coexist. Theoretical analyses by the extended
generalized fishbone-like dispersion relation (GFLDR-E) reveal that mode
frequencies scale with ion diamagnetic drift frequency and , and they
lie in KBM-AITG-BAE frequency ranges. AITG modes are most unstable when the
magnetic shear is small in low pressure gradient regions. Numerical solutions
of the AITG/KBM equation also illuminate why AITG modes can be unstable for
weak shear and low pressure gradients. It is worth emphasizing that these
instabilities may be linked to the internal transport barrier (ITB) and H-mode
pedestal physics for weak magnetic shear.Comment: 9 pages, 7 figure
Plasma microRNA expression profiles in Chinese patients with rheumatoid arthritis
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