Hilbert expansion of the Boltzmann equation in the incompressible Euler level in a channel

The study of hydrodynamic limit of the Boltzmann equation with physical boundary is a challenging problem due to appearance of the viscous and Knudsen boundary layers. In this paper, the hydrodynamic limit from the Boltzmann equation with specular reflection boundary condition to the incompressible Euler in a channel is investigated. Based on the multiscaled Hilbert expansion, the equations with boundary conditions and compatibility conditions for interior solutions, viscous and Knudsen boundary layers are derived under different scaling, respectively. Then some uniform estimates for the interior solutions, viscous and Knudsen boundary layers are established. With the help of $L^2-L^\infty$ framework and the uniform estimates obtained above, the solutions to the Boltzmann equation are constructed by the truncated Hilbert expansion with multiscales, and hence the hydrodynamic limit in the incompressible Euler level is justified.Comment: 66 pages, comments are wellcom

Financial Literacy, Portfolio Choice, and Financial Well-Being

This study examined potential effects of financial literacy on household portfolio choice and investment return, an indicator of financial wellbeing. Using data from the 2014 Chinese Survey of Consumer Finance, financial literacy was measured and further categorized into basic financial literacy and advanced financial literacy. This study tested the hypothesis that financial literacy affects household choice between stock and mutual fund. The results indicated that households with higher financial literacy, especially those with higher level of advanced financial literacy tended to delegate at least part of their portfolio to experts and invest in mutual fund. However, households who were overconfident about their financial literacy tended to invest by themselves and were more likely to hold only stocks in their portfolios. The findings also indicated that households with higher financial literacy had a better chance of receiving a positive investment return, suggesting that higher financial literacy may result in a better financial outcome

Research on the Standardization of Drug Test Data

In order to solve the problems that test data of the drug control institution is not standardized and low quality, the data exchange and information sharing are realized, the data value is mined and the information level is improved. Method: combined with the business of control institution and information practice, refer to the practice of relevant standard development; carry out the research on standard development work from the content, principle and process. Result and conclusion: this research completes development of the local standard of Guangdong drug test data, which can provide reference for the development of similar standards in future

Feasibility of GNSS-R Altimetry Using CyGNSS 8-Satellite Constellation Mission Data

Ponencia expuesta en Scientific Assembly of the International Association of Geodesy (2021) celebrado en Beijing del 28 de junio al 2 de juli

Cefquinome Controlled Size Submicron Particles Precipitation by SEDS Process Using Annular Gap Nozzle

An annular gap nozzle was applied in solution enhanced dispersion by supercritical fluids (SEDS) process to prepare cefquinome controlled size submicron particles so as to enhance their efficacy. Analysis results of orthogonal experiments indicated that the concentration of solution was the primary factor to affect particle sizes in SEDS process, and feeding speed of solution, precipitation pressure, and precipitation temperature ranked second to fourth. Meanwhile, the optimal operating conditions were that solution concentration was 100 mg/mL, feeding speed was 9 mL/min, precipitation pressure was 10 MPa, and precipitation temperature was 316 K. The confirmatory experiment showed that D50 of processed cefquinome particles in optimal operating conditions was 0.73 μm. Moreover, univariate effect analysis showed that the cefquinome particle size increased with the increase of concentration of the solution or precipitation pressure but decreased with the increase of solution feeding speed. When precipitation temperature increased, the cefquinome particle size showed highest point. Moreover, characterization of processed cefquinome particles was analyzed by SEM, FT-IR, and XRD. Analysis results indicated that the surface appearance of processed cefquinome particles was flakes. The chemical structure of processed cefquinome particles was not changed, and the crystallinity of processed cefquinome particles was a little lower than that of raw cefquinome particles

INCREASE IN CANDIDA PARAPSILOSIS CANDIDEMIA IN CANCER PATIENTS

Background: This study aimed to identify the risk factors of candidemia and asses possible clinically significant differences between Candida parapsilosis and other candida species among cancer patients. Methods: A retrospective study was conducted in a Chinese tertiary cancer center over a 6-year period. A total of 323 cancer patients were enrolled and analyzed from 2012 to 2018. Data about demographic characteristics, underlying diseases, and risk factors of candidemia were collected. Univariate and multivariate logistic regression models were used to identify the risk factors associated with the development of candidemia. Results: Among the isolates, the species most frequently isolated was C. parapsilosis (37.15%, 120/323), and C. albicans only accounted for 34.37%. Based on statistical analysis, when candidemia patients who had C. parapsilosis were compared with other Candida spp., the following factors were found to be significantly associated with C. parapsilosis fungemia: parenteral nutrition (p < 0.001), neutropenia (p < 0.001), receipt of chemotherapy (p = 0.002), and previous antifungal use (p < 0.001). Parenteral nutrition was a factor that independently predicted C. parapsilosis candidemia (OR, 0.183; 95% CI, 0.098–0.340; p < 0.001). Conclusions: In short, C. parapsilosis as the leading non-albicans Candida spp. isolates in candidemia is posing a major threat for cancer patients. The study highlights the urgent need to evaluate the possibility of development of C. parapsilosis candidemia in cancer patients exposed to these risk factors effective and prevention strategies against this causative agent transmitted through nosocomial route should be implemented

Preparation of Cefquinome Nanoparticles by Using the Supercritical Antisolvent Process

The supercritical antisolvent process was used successfully to prepare nanoparticles of cefquinome. These particles were observed by scanning electron microscope (SEM) and their average diameter was measured by laser particle size analyzer. In the experiments, dimethyl sulfoxide (DMSO) was selected as solvent to dissolve cefquinome sulfate. It was confirmed by orthogonal experiments that the concentration of solution was the primary factor in this process followed by feeding speed of solution, precipitation pressure, and precipitation temperature. Moreover, the optimal conditions of preparing nanoparticles of cefquinome by supercritical antisolvent process were that solution concentration was 100 mg/mL, solution flow speed was 1.5 mL/min, operating pressure was 13 Mpa, and operating temperature was 33°C. Confirmatory experiment was conducted under this condition. It was found that the appearance of particles was flakes and the average diameter of particles was 0.71 microns. Finally, influence law of individual factor on particle size was investigated by univariate analysis

CYGNSS Ocean Altimetry: A Status Report

Comunicación expuesta online en el CYGNSS Science Team Summer Meeting celebrado del 27 al 29 de julio de 202

Investigation on Geometry Computation of Spaceborne GNSS-R Altimetry over Topography: Modeling and Validation

The spaceborne Global Navigation Satellite Systems Reflectometry (GNSS-R) offers versatile Earth surface observation. While the accuracy of the computed geometry, required for the implementation of the technique, degrades when Earth’s surface topography is complicated, previous studies ignored the effects of the local terrain surrounding the ideal specular point at a suppositional Earth reference surface. The surface slope and its aspect have been confirmed that it can lead to geolocation-related errors in the traditional radar altimetry, which will be even more intensified in tilt observations. In this study, the effect of large-scale slope on the spaceborne GNSS-R technique is investigated. We propose a new geometry computation strategy based on the property of ellipsoid to carry out forward and inverse calculations of path geometries. Moreover, it can be extended to calculate unusual reflected paths over versatile Earth’s topography by taking the surface slope and aspects into account. A simulation considering the slope effects demonstrates potential errors as large as meters to tens kilometers in geolocation and height estimations in the grazing observation condition over slopes. For validation, a single track over the Greenland surface received by the TechDemoSat 1 (TDS-1) satellite with a slope range from 0% to 1% was processed and analyzed. The results show that using the TanDEM-X 90 m Digital Elevation Model (DEM) as a reference, a slope of 0.6% at an elevation angle of 54 degrees can result in a geolocation inaccuracy of 10 km and a height error of 50 m. The proposed method in this study greatly reduces the standard deviation of geolocations of specular points from 4758 m to 367 m, and height retrievals from 28 m to 5.8 m. Applications associated with topography slopes, e.g., cryosphere could benefit from this method