This paper analyses the changing rule of indoor ozone concentration and its influencing factors.A formula of indoor-outdoor concentration ratio(I/O ratio) was deduced based on the indoor ozone mass-balance equation.Th...This paper analyses the changing rule of indoor ozone concentration and its influencing factors.A formula of indoor-outdoor concentration ratio(I/O ratio) was deduced based on the indoor ozone mass-balance equation.The ozone I/O ratio in different kinds of buildings was studied.Results show that I/O ratio is much related to air-exchange rate,which is well compatible with the theoretical calculation results.展开更多
The air bag deformation data were obtained by high-speed dynamic videos experiments. Based on gas–liquid flow VOF model, dynamic mesh technique and deformation data, numerical simulations for different structure mode...The air bag deformation data were obtained by high-speed dynamic videos experiments. Based on gas–liquid flow VOF model, dynamic mesh technique and deformation data, numerical simulations for different structure models were achieved, and the law of water motion and influencing factors were analyzed.The results show that the flow in the length direction of the jig is smooth, and second pulsation appears in the separation time and forms the secondary separation. The installation position of screen and the number of air bags have a great influence on the uniformity of flow and velocity. The screen height cannot be too low to avoid forming the unstable flow. At the same time, the screen height cannot be too high, otherwise water velocity will be too small and was unable to provide enough power. At the height of 1.4m,velocity unevenness is minimum and the best uniform flow can be obtained. Compared with double air bags, there are the following features of single air bag: water flow is not smooth, the time achieving the maximum velocity is too long, maximum velocity is smaller, and overall effect is worse than double air bags.展开更多
This paper is based on a literature review of foreign research regarding the relationship between： SSI （surgical-site infection） and operating room cleaning ventilation, the change of cleanroom technical factors of...This paper is based on a literature review of foreign research regarding the relationship between： SSI （surgical-site infection） and operating room cleaning ventilation, the change of cleanroom technical factors of ventilation, and air conditioning in operating rooms. The differences between foreign codes and Chinese codes on cleaning and the air conditioning index of operating rooms are discussed. The historic background of the founding of the current Chinese clean operating room codes was analyzed. The author appealed to insiders for awareness and concentration on international medical research results involved in cleaning and air conditioning techniques of operating rooms. The current domestic codes should be modified based on the real situation of China. Therefore, the development of medical facilities can be fulfilled.展开更多
Environmental characteristics are often the factors that determine the distribution of species in nature. However, species response vis-A-vis these factors differs. For a better understanding of the phenomenon, we hav...Environmental characteristics are often the factors that determine the distribution of species in nature. However, species response vis-A-vis these factors differs. For a better understanding of the phenomenon, we have conducted this study which consists of following the spatio-temporal evolution of two species of Oribatida （Scheloribates sp. and Galumna sp.）. The sites which have been the subject of this study, are situated in different bioclimatic zones presenting a very different climatic, edaphic, nutritional, and altitudinal characteristics. The variability of ecological factors showed that the behavior of two species differs. Indeed, Scheloribates sp. is present in all sites except in Biskra whereas Galumna sp. is present only in sites belonging to humid and sub humid bioclimatic zones. Moreover, Scheloribates sp. appears more tolerant of environmental changes while Galumna sp. is more stringent and its presence is marked only in the sites where ecological conditions are better. Thus, it can be noted that the spatial and temporal distribution of oribatid is not only conditioned solely by environmental factors but also by intrinsic factors specific to each species. The specific behavior of Galumna sp. and the tolerance of Scheloribates sp. are interesting and can be the subject of bioindicator species that can inform us about the changes that effect whether natural or anthropogenic environment.展开更多
China's Loess Plateau is located at the edge of the Asian summer monsoon in a transition zone of climate and ecology. In the Loess Plateau, climate and environments change along with space, which has an obvious im...China's Loess Plateau is located at the edge of the Asian summer monsoon in a transition zone of climate and ecology. In the Loess Plateau, climate and environments change along with space, which has an obvious impact on the spatial distribution of surface energy fluxes. Because of scarce land-surface observation sites and short observation time in this area, previous studies have failed to fully understand the land-surface energy balance characteristics over the entire the Loess Plateau and their effect mechanisms. In this paper, we first test the simulation ability of the Community Land Model(CLM) model by comparing its simulated data with observed data. Based on the simulation data for the Loess Plateau over the past thirty years, we then analyze the spatial distribution of surface energy fluxes and compare the pattern differences between the area averages for the driest year and wettest year. Furthermore, we analyze the relationship between the spatial distribution of the components of the surface energy balance with longitude, latitude, altitude, precipitation and temperature. The main results are as follows: the spatial distribution of surface energy fluxes are significantly different, with the surface net radiation and sensible heat flux increasing from south to north and latent heat flux and soil heat flux decreasing from southeast to northwest. The sensible heat flux at the driest point is nearly twice as high as that at the wettest point, whereas the latent heat flux and soil heat flux at the driest point are half as much as that at the wettest point. The impact of variations of annual precipitation on the components of the surface energy balance is also obvious, and the maximum magnitude of the changes to the sensible heat flux and latent heat flux is nearly 30%. To a certain extent, geographical factors(including longitude, latitude, and altitude) and climate factors(including temperature and precipitation) affect the surface energy fluxes. However, the surface net radiation is more closely related to latitude and altitude, sensible heat flux is more closely related to the monsoon rainfall and latitude, and latent heat flux and soil heat flux are more closely related to the monsoon rainfall.展开更多
Cosmic rays(CR)play an important role in space weather-related studies.Their temporal variability,both of a quasi-periodic character as well as an irregular one,has been studied from ground-based direct measurements,a...Cosmic rays(CR)play an important role in space weather-related studies.Their temporal variability,both of a quasi-periodic character as well as an irregular one,has been studied from ground-based direct measurements,as well as from cosmogenic nuclides,over a long time.We attempt to describe the current knowledge of selected quasi-periodicities in CR flux in the energy range above the atmospheric threshold,from direct measurements.The power spectrum density(PSD)of the CR time series as measured by neutron monitors(NMs)and by muon detectors has a rather complicated character.Along with the shape(slope)of the PSD,knowledge of the contribution of quasi-periodic variations(q-per)to the CR signal is of importance for the modulation,as well as for checking the links of CR to space weather,and/or to space climate effects.The rotation of the Earth and solar rotation cause two types of mechanisms behind the certain q-per observed in secondary CR on the Earth’s surface.Solar activity and solar magnetic field cyclicities contribute to the q-per signals in CR if studied over a longer time.The complexity of the spatial structure of the interplanetary magnetic field(IMF)and its evolution within the heliosphere,in addition to the changes in the geomagnetic field,cause variability in contributions of the q-per in CR.Wavelet spectra are useful tools for checking the fine structure of q-per and their temporal behaviour.Over a long time NMs and muon telescopes provide information about q-per in CR.展开更多
文摘This paper analyses the changing rule of indoor ozone concentration and its influencing factors.A formula of indoor-outdoor concentration ratio(I/O ratio) was deduced based on the indoor ozone mass-balance equation.The ozone I/O ratio in different kinds of buildings was studied.Results show that I/O ratio is much related to air-exchange rate,which is well compatible with the theoretical calculation results.
基金provided by the Project of National Scientific and Technical Supporting Programs Funded of China(No.2012BAB13B03)
文摘The air bag deformation data were obtained by high-speed dynamic videos experiments. Based on gas–liquid flow VOF model, dynamic mesh technique and deformation data, numerical simulations for different structure models were achieved, and the law of water motion and influencing factors were analyzed.The results show that the flow in the length direction of the jig is smooth, and second pulsation appears in the separation time and forms the secondary separation. The installation position of screen and the number of air bags have a great influence on the uniformity of flow and velocity. The screen height cannot be too low to avoid forming the unstable flow. At the same time, the screen height cannot be too high, otherwise water velocity will be too small and was unable to provide enough power. At the height of 1.4m,velocity unevenness is minimum and the best uniform flow can be obtained. Compared with double air bags, there are the following features of single air bag: water flow is not smooth, the time achieving the maximum velocity is too long, maximum velocity is smaller, and overall effect is worse than double air bags.
文摘This paper is based on a literature review of foreign research regarding the relationship between： SSI （surgical-site infection） and operating room cleaning ventilation, the change of cleanroom technical factors of ventilation, and air conditioning in operating rooms. The differences between foreign codes and Chinese codes on cleaning and the air conditioning index of operating rooms are discussed. The historic background of the founding of the current Chinese clean operating room codes was analyzed. The author appealed to insiders for awareness and concentration on international medical research results involved in cleaning and air conditioning techniques of operating rooms. The current domestic codes should be modified based on the real situation of China. Therefore, the development of medical facilities can be fulfilled.
文摘Environmental characteristics are often the factors that determine the distribution of species in nature. However, species response vis-A-vis these factors differs. For a better understanding of the phenomenon, we have conducted this study which consists of following the spatio-temporal evolution of two species of Oribatida （Scheloribates sp. and Galumna sp.）. The sites which have been the subject of this study, are situated in different bioclimatic zones presenting a very different climatic, edaphic, nutritional, and altitudinal characteristics. The variability of ecological factors showed that the behavior of two species differs. Indeed, Scheloribates sp. is present in all sites except in Biskra whereas Galumna sp. is present only in sites belonging to humid and sub humid bioclimatic zones. Moreover, Scheloribates sp. appears more tolerant of environmental changes while Galumna sp. is more stringent and its presence is marked only in the sites where ecological conditions are better. Thus, it can be noted that the spatial and temporal distribution of oribatid is not only conditioned solely by environmental factors but also by intrinsic factors specific to each species. The specific behavior of Galumna sp. and the tolerance of Scheloribates sp. are interesting and can be the subject of bioindicator species that can inform us about the changes that effect whether natural or anthropogenic environment.
基金supported by the State Key Program of National Natural Science of China (Grant No. 40830957)the National Key Basic Research Program (Grant Nos. 2013CB430200, 2013CB430206)
文摘China's Loess Plateau is located at the edge of the Asian summer monsoon in a transition zone of climate and ecology. In the Loess Plateau, climate and environments change along with space, which has an obvious impact on the spatial distribution of surface energy fluxes. Because of scarce land-surface observation sites and short observation time in this area, previous studies have failed to fully understand the land-surface energy balance characteristics over the entire the Loess Plateau and their effect mechanisms. In this paper, we first test the simulation ability of the Community Land Model(CLM) model by comparing its simulated data with observed data. Based on the simulation data for the Loess Plateau over the past thirty years, we then analyze the spatial distribution of surface energy fluxes and compare the pattern differences between the area averages for the driest year and wettest year. Furthermore, we analyze the relationship between the spatial distribution of the components of the surface energy balance with longitude, latitude, altitude, precipitation and temperature. The main results are as follows: the spatial distribution of surface energy fluxes are significantly different, with the surface net radiation and sensible heat flux increasing from south to north and latent heat flux and soil heat flux decreasing from southeast to northwest. The sensible heat flux at the driest point is nearly twice as high as that at the wettest point, whereas the latent heat flux and soil heat flux at the driest point are half as much as that at the wettest point. The impact of variations of annual precipitation on the components of the surface energy balance is also obvious, and the maximum magnitude of the changes to the sensible heat flux and latent heat flux is nearly 30%. To a certain extent, geographical factors(including longitude, latitude, and altitude) and climate factors(including temperature and precipitation) affect the surface energy fluxes. However, the surface net radiation is more closely related to latitude and altitude, sensible heat flux is more closely related to the monsoon rainfall and latitude, and latent heat flux and soil heat flux are more closely related to the monsoon rainfall.
基金Project VEGA 2/0040/13 for supportKuwait for supporting project HS-13-01
文摘Cosmic rays(CR)play an important role in space weather-related studies.Their temporal variability,both of a quasi-periodic character as well as an irregular one,has been studied from ground-based direct measurements,as well as from cosmogenic nuclides,over a long time.We attempt to describe the current knowledge of selected quasi-periodicities in CR flux in the energy range above the atmospheric threshold,from direct measurements.The power spectrum density(PSD)of the CR time series as measured by neutron monitors(NMs)and by muon detectors has a rather complicated character.Along with the shape(slope)of the PSD,knowledge of the contribution of quasi-periodic variations(q-per)to the CR signal is of importance for the modulation,as well as for checking the links of CR to space weather,and/or to space climate effects.The rotation of the Earth and solar rotation cause two types of mechanisms behind the certain q-per observed in secondary CR on the Earth’s surface.Solar activity and solar magnetic field cyclicities contribute to the q-per signals in CR if studied over a longer time.The complexity of the spatial structure of the interplanetary magnetic field(IMF)and its evolution within the heliosphere,in addition to the changes in the geomagnetic field,cause variability in contributions of the q-per in CR.Wavelet spectra are useful tools for checking the fine structure of q-per and their temporal behaviour.Over a long time NMs and muon telescopes provide information about q-per in CR.
