A Geologic Time Scale (GTS2004) is presented that integrates currently available stratigraphic and geochronologic information. Key features of the new scale are outlined, how it was constructed, and how it can be furt...A Geologic Time Scale (GTS2004) is presented that integrates currently available stratigraphic and geochronologic information. Key features of the new scale are outlined, how it was constructed, and how it can be further improved. The accompanying International Stratigraphic Chart, issued under auspices of the International Commission on Stratigraphy (ICS), shows the current chronostratigraphic scale and ages with estimates of uncertainty for all stage boundaries. Special reference is made to the Precambrian part of the time scale, which is coming of age in terms of detail, and to the Neogene portion, which has attained an ultra-high-precision absolute-age calibration.展开更多
Thermal safety of modular charge which is fed into and retained in the chamber after gun fires consecutively is first investigated with cook-off method,A two-dimensional cook-off model of modular charge in gun chamber...Thermal safety of modular charge which is fed into and retained in the chamber after gun fires consecutively is first investigated with cook-off method,A two-dimensional cook-off model of modular charge in gun chamber is established and the cook-off process of modular charge in gun chamber is numerically simulated.Then the effects of module number and firing condition on charge thermal safety are evaluated by researching the cook-off response characteristics of modules.The results show that under conditions of different module numbers the cook-off responses all occur on the module closest to the boundary of missile,and the single-base propellants located at the inner surface of cartridge ignite first.When the number of loaded module changes from 1 to 6,the cook-off response temperatures vary little,only in a small range of 478.1 K-482.4 K.The cook-off response times decrease logarithmically in the range of 211.25-166.7 s with the increasing length of residual air gap in gun chamber.The simulation results are well matched with the experimental data.Furthermore,different firing conditions have greatinfluence on the cook-off response time,minor influence on the initial response position and little in-fluence on the response temperature.Under the three conditions of consecutive 32 launches with 5 rounds/min,43 launches with 1 round/min,and 41 launches with different firing frequencies,the cook off response temperatures are 479.2 K,481.1 K and 479.9 K respectively and the response times are 709.25,211.2 s and 214.4 s respectively.The response position is near the middle area of the inner cartridge surface in the former condition and near the right area in the latter two conditions.展开更多
The study has shown that the shear component of the vertical integrated kinetic energy(Ks)over the box(40oE-100oE,0-20oN)can be used to measure the intensity of the South Asian summer monsoon(SASM).Based on its value ...The study has shown that the shear component of the vertical integrated kinetic energy(Ks)over the box(40oE-100oE,0-20oN)can be used to measure the intensity of the South Asian summer monsoon(SASM).Based on its value averaged between June and August,the SASM can be divided into strong and weak monsoon episodes.Between1958 and 2018,there existed 16(16)strong(weak)monsoon episodes.Based on the calendar year,the relationship between the SASM and ENSO episodes can be grouped into six patterns:weak monsoon-El Ni?o(WM-EN),normal monsoon-El Ni?o(NM-EN),weak monsoon-non ENSO(WM-NE),strong monsoon-La Ni?a(SM-LN),normal monsoon-La Ni?a(NM-LN)and strong monsoon-non ENSO(SM-NE).Previous studies suggest that the WM-EN and SM-LN patterns reflect the correlated relationship between the SASM and El Ni?o/Southern Oscillation(ENSO)events.Therefore,we name these two strongly coupled categories WM-EN and SM-LN as the resonance effect.Two important circulations,i.e.,Walker circulation(WC)and zonal Asian monsoon circulation(MC),in the vertical plane are found to be not always correlated.The MC is controlled by thermal gradients between the Asian landmass and the tropical Indian Ocean,while the WC associated with ENSO events is primarily the east-west thermal gradient between the tropical South Pacific and the tropical Indian Ocean.Furthermore,the gradient directions caused by different surface thermal conditions are different.The main factor for the resonance effect is the phenomenon that the symbols of SSTA in the tropical Indian Ocean and the equatorial eastern Pacific are the same,but are opposite to that of the SSTA near the maritime continent.展开更多
1绘制场景,让“事件”发生COA:aoe事建组的名称来源于建筑大师Bernard Tschumi的名言“there is no architecture without event”。您怎么理解建筑设计中的“事件”一词?建筑设计又该如何与“事件”相结合?温群:aoe的意思是architectur...1绘制场景,让“事件”发生COA:aoe事建组的名称来源于建筑大师Bernard Tschumi的名言“there is no architecture without event”。您怎么理解建筑设计中的“事件”一词?建筑设计又该如何与“事件”相结合?温群:aoe的意思是architecture of events,中文用了谐音叫“事建组”。在我看来建筑设计的最终目的是为了使用者也就是为人提供一个空间场所以满足其特定的需求,比如住宅是满足居住的需求,学校是满足教学的需求等。脱离了人的空间场所是没有意义的,只有当人与空间场所产生互动时设计才变得有意义,这样的一种互动就会激发事件的产生。展开更多
People will move around more easily as China's anti-COvID measures improve,and all economic and social activities will hasten their recovery pace in the new year.
Shanghai has experienced the greatest land subsidence in China in the past sixty years and produced undesirable environmental impact. However, horizontal ground deformation has not been understood yet. Therefore groun...Shanghai has experienced the greatest land subsidence in China in the past sixty years and produced undesirable environmental impact. However, horizontal ground deformation has not been understood yet. Therefore ground deformation monitoring together with the analysis of its driving forces are critical for geo-hazards early-warning, city planning and sustainable urbanization in Shanghai. In this paper, two-dimensional ground deformation monitoring was performed in Shanghai with SBAS and MSBAS InSAR methods. Twenty-nine Multi-Look Fine 6 （MF6） Radarsat-2 SLC data acquired during 2011-2013 were used to derive vertical ground deformation. Meanwhile, six descending Multi-Look Fine 6 （MF6） and four ascending Multi-Look Fine 2 （MF2） spanning April to August, 2008, were used to derive vertical and horizontal ground deformation during the observation period. The results indicate that vertical and horizontal deformations in 2008 were not homogeneously distributed in different districts ranging from 0-2 cm/year. Vertical deformation rate during 2011-2013 were decreased to less than 1 cm/year in most district of Shanghai area. Activities from groundwater exploitation and rapid urbanization are responsible for most of the ground deformation in Shanghai. Thus, future ground deformation in vertical and horizontal directions should be warranted.展开更多
We consider nested or multiscale models to study the effect of the temporal evolution of the disease within the host in the population dynamics of the disease,for one and two infectious agents.We assumed a coupling be...We consider nested or multiscale models to study the effect of the temporal evolution of the disease within the host in the population dynamics of the disease,for one and two infectious agents.We assumed a coupling between the within-host infection rate and the between-host transmission rate.The age of infection within each individual in a population affects the probability of transmission of the disease to a susceptible host and this will affect the temporal evolution of the disease in the host population.To analyze the infection within the host,we consider bacterial-like and viral-like infections.In the model for two infectious agents,we found that,when strain 2 has a basic reproduction number R02 greater than the basic reproduction number R01 of strain 1,strain 2 replaces strain 1 in the population.However,if R02>R01 but the values are closer,the replacement does not occur immediately and both strains can coexist for a long time.We applied the model to a scenario in which patients infected with the hepatitis C virus(HCV)are cleared of HCV when super-infected with the hepatitis A virus(HAV).We compared the time for the replacement of HCV by HAV in the population considering instantaneous and noninstantaneous replacement within the individuals.The model developed can be generalized for more than two infectious agents.展开更多
文摘A Geologic Time Scale (GTS2004) is presented that integrates currently available stratigraphic and geochronologic information. Key features of the new scale are outlined, how it was constructed, and how it can be further improved. The accompanying International Stratigraphic Chart, issued under auspices of the International Commission on Stratigraphy (ICS), shows the current chronostratigraphic scale and ages with estimates of uncertainty for all stage boundaries. Special reference is made to the Precambrian part of the time scale, which is coming of age in terms of detail, and to the Neogene portion, which has attained an ultra-high-precision absolute-age calibration.
文摘Thermal safety of modular charge which is fed into and retained in the chamber after gun fires consecutively is first investigated with cook-off method,A two-dimensional cook-off model of modular charge in gun chamber is established and the cook-off process of modular charge in gun chamber is numerically simulated.Then the effects of module number and firing condition on charge thermal safety are evaluated by researching the cook-off response characteristics of modules.The results show that under conditions of different module numbers the cook-off responses all occur on the module closest to the boundary of missile,and the single-base propellants located at the inner surface of cartridge ignite first.When the number of loaded module changes from 1 to 6,the cook-off response temperatures vary little,only in a small range of 478.1 K-482.4 K.The cook-off response times decrease logarithmically in the range of 211.25-166.7 s with the increasing length of residual air gap in gun chamber.The simulation results are well matched with the experimental data.Furthermore,different firing conditions have greatinfluence on the cook-off response time,minor influence on the initial response position and little in-fluence on the response temperature.Under the three conditions of consecutive 32 launches with 5 rounds/min,43 launches with 1 round/min,and 41 launches with different firing frequencies,the cook off response temperatures are 479.2 K,481.1 K and 479.9 K respectively and the response times are 709.25,211.2 s and 214.4 s respectively.The response position is near the middle area of the inner cartridge surface in the former condition and near the right area in the latter two conditions.
基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20060503)Fund of Southern Marine Science and Engineering Guangdong Laboratory(ZJW-2019-08)+2 种基金National Key R&D Program of China(2017YFC1501802,2018YFA0605604)Project of Enhancing School with Innovation of Guangdong Ocean University(230419053)Projects(Platforms)for Construction of Topranking Disciplines of Guangdong Ocean University(231419022)
文摘The study has shown that the shear component of the vertical integrated kinetic energy(Ks)over the box(40oE-100oE,0-20oN)can be used to measure the intensity of the South Asian summer monsoon(SASM).Based on its value averaged between June and August,the SASM can be divided into strong and weak monsoon episodes.Between1958 and 2018,there existed 16(16)strong(weak)monsoon episodes.Based on the calendar year,the relationship between the SASM and ENSO episodes can be grouped into six patterns:weak monsoon-El Ni?o(WM-EN),normal monsoon-El Ni?o(NM-EN),weak monsoon-non ENSO(WM-NE),strong monsoon-La Ni?a(SM-LN),normal monsoon-La Ni?a(NM-LN)and strong monsoon-non ENSO(SM-NE).Previous studies suggest that the WM-EN and SM-LN patterns reflect the correlated relationship between the SASM and El Ni?o/Southern Oscillation(ENSO)events.Therefore,we name these two strongly coupled categories WM-EN and SM-LN as the resonance effect.Two important circulations,i.e.,Walker circulation(WC)and zonal Asian monsoon circulation(MC),in the vertical plane are found to be not always correlated.The MC is controlled by thermal gradients between the Asian landmass and the tropical Indian Ocean,while the WC associated with ENSO events is primarily the east-west thermal gradient between the tropical South Pacific and the tropical Indian Ocean.Furthermore,the gradient directions caused by different surface thermal conditions are different.The main factor for the resonance effect is the phenomenon that the symbols of SSTA in the tropical Indian Ocean and the equatorial eastern Pacific are the same,but are opposite to that of the SSTA near the maritime continent.
文摘1绘制场景,让“事件”发生COA:aoe事建组的名称来源于建筑大师Bernard Tschumi的名言“there is no architecture without event”。您怎么理解建筑设计中的“事件”一词?建筑设计又该如何与“事件”相结合?温群:aoe的意思是architecture of events,中文用了谐音叫“事建组”。在我看来建筑设计的最终目的是为了使用者也就是为人提供一个空间场所以满足其特定的需求,比如住宅是满足居住的需求,学校是满足教学的需求等。脱离了人的空间场所是没有意义的,只有当人与空间场所产生互动时设计才变得有意义,这样的一种互动就会激发事件的产生。
文摘People will move around more easily as China's anti-COvID measures improve,and all economic and social activities will hasten their recovery pace in the new year.
基金supported by the China Science National Foundation (No. 41372353)
文摘Shanghai has experienced the greatest land subsidence in China in the past sixty years and produced undesirable environmental impact. However, horizontal ground deformation has not been understood yet. Therefore ground deformation monitoring together with the analysis of its driving forces are critical for geo-hazards early-warning, city planning and sustainable urbanization in Shanghai. In this paper, two-dimensional ground deformation monitoring was performed in Shanghai with SBAS and MSBAS InSAR methods. Twenty-nine Multi-Look Fine 6 （MF6） Radarsat-2 SLC data acquired during 2011-2013 were used to derive vertical ground deformation. Meanwhile, six descending Multi-Look Fine 6 （MF6） and four ascending Multi-Look Fine 2 （MF2） spanning April to August, 2008, were used to derive vertical and horizontal ground deformation during the observation period. The results indicate that vertical and horizontal deformations in 2008 were not homogeneously distributed in different districts ranging from 0-2 cm/year. Vertical deformation rate during 2011-2013 were decreased to less than 1 cm/year in most district of Shanghai area. Activities from groundwater exploitation and rapid urbanization are responsible for most of the ground deformation in Shanghai. Thus, future ground deformation in vertical and horizontal directions should be warranted.
基金The authors thank CAPES,LIM-01 HCFMUSP and FAPESP for partial financial supportFA thanks CNPq for financial support through a post doctoral fellowship(grant number 501799/2013-3).
文摘We consider nested or multiscale models to study the effect of the temporal evolution of the disease within the host in the population dynamics of the disease,for one and two infectious agents.We assumed a coupling between the within-host infection rate and the between-host transmission rate.The age of infection within each individual in a population affects the probability of transmission of the disease to a susceptible host and this will affect the temporal evolution of the disease in the host population.To analyze the infection within the host,we consider bacterial-like and viral-like infections.In the model for two infectious agents,we found that,when strain 2 has a basic reproduction number R02 greater than the basic reproduction number R01 of strain 1,strain 2 replaces strain 1 in the population.However,if R02>R01 but the values are closer,the replacement does not occur immediately and both strains can coexist for a long time.We applied the model to a scenario in which patients infected with the hepatitis C virus(HCV)are cleared of HCV when super-infected with the hepatitis A virus(HAV).We compared the time for the replacement of HCV by HAV in the population considering instantaneous and noninstantaneous replacement within the individuals.The model developed can be generalized for more than two infectious agents.
