Search

Clouds have been known as the key components of atmospheric processes in climate, weather, and environment related issues. Owing to its highly complicated processes relating to atmospheric dynamic, macro and microphysical characteristics reveal distinct regional and seasonal features, thus observations at various typical sites are very important to quantitatively understand cloud characteristics with their functions. In this paper, we introduce combined ground-based instruments, i.e., a Mie Lidar, a Ka-band Doppler radar, an IR and a visible all sky imagers, and an automatic weather station, to continuously observe the clouds over Beijing. Synthetic analyses are made to derive the cloud base height, vertical structure, horizontal distribution, radiative effect, etc. About 1 year observation data are used to obtain the statistics of cloud characteristics in this area. A simple introduction of the surface-based remote sensing system and some preliminary results are given. [ABSTRACT FROM AUTHOR]

In the last three years (1999 to 2001), the gallium triple-point cell has been successfully developed, and much corresponding research has been carried out at the National Institute of Metrology (NIM), Beijing, China. This paper presents the cell design, apparatus and procedure for realizing the gallium triple point, and presents studies on the different freezing methods. The reproducibility is 0.03 mK, and the expanded uncertainty of realization of the gallium triple point is evaluated to be 0.17 mK (p=0.99, k=2.9). Also, the reproducibility of the gallium triple point was compared with that of the triple point of water. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

The Earth's greenhouse gases absorb heat, a rise in greenhouse gas emissions have resulted in global warming, which is affecting the planet's climate in numerous ways. The aim of this research is to study the effect of greenhouse gases on the temperature of the two layers of the atmosphere (troposphere and mesosphere) with the presence of solar radiation effect by taking into account the climate change. The monthly data for GHGs, solar radiation and temperature are taken for the period (2000-2018) above the capital Beijing (latitude 40˚N; longitude 116˚E) in China. The results of data analysis show that, in the tropospheric layer the greenhouse gases have increased and also accompanied by an increase in temperature, an increase in temperature appears despite the decrease in solar rays, and this is strong evidence that greenhouse gases have a significant impact on temperatures, also the increase in greenhouse gases and decrease in solar radiation have a cooling effect on the mesosphere layer. [ABSTRACT FROM AUTHOR]

This paper introduced the group of Women in Physics of Chinese Physical Society, Beijing. An investigation of the female ratio in physics for 13 universities and 2 institutes of Chinese Academy of Sciences is presented. The results show that in China the ratio of women in physics is around 20%, and the higher the career position, the lower ratio becomes. [ABSTRACT FROM AUTHOR]

Based on the 110M ψ(3686) data sample which has been collected by BESIII at year 2009, many χcJ decay modes have been measured, such as χcJ → π0π0, χcJ → ηη, χcJ → VV, χcJ → γV, and so on. Results presented in this document are preliminary. [ABSTRACT FROM AUTHOR]

The new BES III detector at BEPCII collected 106 million ψ[acute_underaccent] and about 226 million J/ψ events in 2009. Results based on these samples are reported, including branching ratios for χXcJ → π0π0,ηη, 4π0, γyV and VV, where V is a ρ, ω, or [uppercase_phi_synonym] as well as first measurements of the branching ratios for ψ → γ0hc and hc → γηc and measurements of the mass and width of the hc. Results in hadron spectroscopy include the confirmation of the pp threshold enhancement in J/ψ→γpp and confirmation of the X(1835) in J/ψ→γη[acute_underaccent]π+π- [ABSTRACT FROM AUTHOR]

Partial wave analysis (PWA) is a core tool for determining resonance properties in hadron spectroscopy. The unbinned likelihood fits employed are however computationally very expensive especially in view of the very large data samples being collected at the Beijing Spectrometer (BES) III experiment and expected from future experiments such as Glue-X and PANDA. Using the power of massively parallel floating point calculations on graphics processing units (GPUs), we have managed to speed up PWA by more than two orders of magnitude compared to legacy implementations. The resulting software framework allows for the fast creation and running of PWA code. Modern hardware and software thus solve the PWA speed problems-many questions concerning fit methods and especially the reliability of fit results however remain open. [ABSTRACT FROM AUTHOR]

4B8 beamline at Beijing Synchrotron Radiation Facility (BSRF) is based on the previous 3B1B beamline with some modification. This beamline will focus on the advancement of vacuum ultraviolet circular dichroism (CD) spectroscopy for studying secondary structure of proteins. Along with beamline moving, some measurements are taken to overcome the exposed problems in 3B1B, such as optical contamination, high stray light level. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Discusses the promotion of women physicists' image in Beijing, China. Physics posters printed by Chinese Physical Society; Articles about the experiences of women physicists published in the periodical "Physics"; Outstanding women in science honored by the Chinese Academy of Sciences.