Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is e...Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is estimated that in the scenario of activation of the North Tehran fault, many structures in Tehran will collapse. Therefore, it is necessary to incorporate the near field rupture directivity effects of this fault into the seismic hazard assessment of important sites in Tehran. In this study, using calculations coded in MATLAB, Probabilistic Seismic Hazard Analysis (PSHA) is conducted for an important site in Tehran. Following that, deaggregation technique is performed on PSHA and the contribution of seis- mic scenarios to hazard is obtained in the range of distance and magnitude. After identifying the North Tehran fault as the most hazardous source affecting the site in 10000-year return period, rupture directivity effects of this fault is incorporated into the seismic hazard assessment using Somerville et al. (1997) model with broadband approach and Shahi and Baker (2011) model with narrowband approach. The results show that the narrowband approach caused a 27% increase in the peak of response spectrum in 10000-year return period compared with the conventional PSHA. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.展开更多
Objective:To investigate the inhibitory effect of curcumin on influenza virus HIN1 and H3N2 in vitro, Methods:The directly killing role of cureumin extract in vitro to influenza virus type A subtype H1N1 and H3N2 wa...Objective:To investigate the inhibitory effect of curcumin on influenza virus HIN1 and H3N2 in vitro, Methods:The directly killing role of cureumin extract in vitro to influenza virus type A subtype H1N1 and H3N2 was evaluated by the canine kidney cells (MDCK), Results:The largest non toxic concentration of curcumin extract was 12, 5g/L and the effective inhibitory concentration to H1N1 and H3N2 was 6, 25G/1 AND 1,56g/L respectively, Conclusion: Curcumin extract have directly killing effect on H1N1 and H3N2 infections.展开更多
The direct climatic effect of aerosols for the 1980-2000 period over East Asia was numerically investigated by a regional scale coupled climate-chemistry/ aerosol model, which includes major anthropogenic aerosols (s...The direct climatic effect of aerosols for the 1980-2000 period over East Asia was numerically investigated by a regional scale coupled climate-chemistry/ aerosol model, which includes major anthropogenic aerosols (sulfate, black carbon, and organic carbon) and natural aerosols (soil dust and sea salt). Anthropogenic emissions used in model simulation are from a global emission inventory prepared for the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5), whereas natural aerosols are calculated online in the model. The simulated 20-year average direct solar radiative effect due to aerosols at the surface was estimated to be in a range of-9- -33 W m-2 over most areas of China, with maxima over the Gobi desert of West China, and-12 W m-2 to -24 W m-2 over the Sichuan Basin, the middle and lower reaches of the Yellow River and the Yangtze River. Aerosols caused surface cooling in most areas of East Asia, with maxima of-0.8℃ to -1.6℃ over the deserts of West China, the Sichuan Basin, portions of central China, and the middle reaches of the Yangtze River. Aerosols induced a precipitation decrease over almost the entire East China, with maxima of-90 mm/year to -150 mm/year over the Sichuan Basin, the middle reaches of the Yangtze River and the lower reaches of the Yellow River. Interdecadal variation of the climate response to the aerosol direct radiative effect is evident, indicating larger decrease in surface air temperature and stronger per- turbation to precipitation in the 1990s than that in the 1980s, which could be due to the interdecadal variation of anthropogenic emissions.展开更多
Direct climate responses to dust shortwave and longwave radiative forcing (RF) are studied using the NCAR Community Atmosphere Model Version 3 (CAM3). The simulated RF at the top of the atmosphere (TOA) is-0.45 ...Direct climate responses to dust shortwave and longwave radiative forcing (RF) are studied using the NCAR Community Atmosphere Model Version 3 (CAM3). The simulated RF at the top of the atmosphere (TOA) is-0.45 W m-2 in the solar spectrum and +0.09 W m-2 in the thermal spectrum on a global average. The magnitude of surface RF is larger than the TOA forcing, with global mean shortwave forcing of-1.76 W m-2 and longwave forcing of +0.31 W m-2 . As a result, dust aerosol causes the absorption of 1.1 W m-2 in the atmosphere. The RF of dust aerosol is predicted to lead to a surface cooling of 0.5 K over the Sahara Desert and Arabian Peninsula. In the meantime, the upper troposphere is predicted to become warmer because of the absorption by dust. These changes in temperature lead to a more stable atmosphere, which results in increases in surface humidity. The upward sensible and latent heat fluxes at the surface are reduced, largely balancing the surface energy loss caused by the backscattering and absorption of dust aerosol. Precipitation is predicted to decrease moderately on a global scale.展开更多
The authors examine the equilibrium climatic response to the direct radiative effect (DRE) of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions.In resp...The authors examine the equilibrium climatic response to the direct radiative effect (DRE) of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions.In response to the drier and windier conditions,dust emissions increase by 26% in the Sahara Desert and by 18% on the global scale relative to present day.Sea salt emissions increase in high latitudes (>60°) but decrease in middle latitudes (30°-60°) of both hemispheres due to the poleward shift of westerlies,leading to a 3% decrease in global emissions.The burdens of dust and sea salt increase by 31% and 7% respectively,because reductions in rainfall over the tropical oceans increase the lifetime of particles in the warmer climate.The higher aerosol loading in the doubled-CO2 climate reinforces aerosol DRE by -0.2 W m-2,leading to an additional cooling of 0.1℃ at the surface compared with the climatic effects of aerosols in present day.The additional cooling from changes in natural aerosols compensates for up to 15% of the regional warming induced by doubled CO2.展开更多
The estimate of seismic site effects by experimental approaches is based on different assumptions aimed at simplifying the complex actual site conditions and related uncertainties.However,the reliability of the result...The estimate of seismic site effects by experimental approaches is based on different assumptions aimed at simplifying the complex actual site conditions and related uncertainties.However,the reliability of the results can increase if the experimental data is focused on quite strong seismic sequences and the on-site acquisition of a large number of signals is deemed strategic for the assessment of the expected phenomena.Based on these considerations,the ground motion at the Red Zone sector of Amatrice hill,violently struck by the 2016-2017 Central Italy seismic sequence,was analyzed via an observational approach.A large set of weak motions(moment magnitude Mw 2.5-3.9)was analyzed in this study by means of standard(SSR)and horizontal to vertical(HVSR)spectral ratio techniques.The results from the experimental analysis of the site effects by using weak motion and noise signals show a significant amplification at the top of Amatrice hill with a remarkable polarization of the motion and changes in spectral shapes according to the topographic setting of the relief.展开更多
Direct piezoelectricity of electro-active papers (EAPap) is analysed in this paper. The test setups for direct effect are designed and determined. Different ambient factors impacting the piezoelectricity of EAPap, s...Direct piezoelectricity of electro-active papers (EAPap) is analysed in this paper. The test setups for direct effect are designed and determined. Different ambient factors impacting the piezoelectricity of EAPap, such as temperature, humidity, and strain rate, are applied and analyzed. Strong piezoelectricity of EAPap is found on the basis of the test results and in comparison with polyvinylidene fluoride (PVDF) and lead zirconate titanate (PZT)-5H. The maximum piezoelectric constant is achieved to be 504 pC/N. The reason of strong piezoelectricity of EAPap is discussed in this paper. The potential of EAPap as a biomimetic actuator and sensor is also investigated.展开更多
The Regional Integrated Environmental Model System (RIEMS 2.0) coupled with a chemistry-aerosol model and the Princeton Ocean Model (POM) is employed to simulate regional oceanic impact on atmospheric circulation ...The Regional Integrated Environmental Model System (RIEMS 2.0) coupled with a chemistry-aerosol model and the Princeton Ocean Model (POM) is employed to simulate regional oceanic impact on atmospheric circulation and the direct radiative effect (DRE) of aerosol over East Asia. The aerosols considered in this study include both major anthropogenic aerosols (e.g., sulfate, black carbon, and organic carbon) and natural aerosols (e.g., soil dust and sea salt). The RIEMS 2.0 is driven by NCEP/NCAR reanalysis II, and the simulated period is from 1 January to 31 December 2006. The results show the following: (1) The simulated annual mean sea-level pressure by RIEMS 2.0 with POM is lower than without POM over the mainland and higher without POM over the ocean. (2) In summer, the subtropical high simulated by RIEMS 2.0 with POM is stronger and extends further westward, and the continental low is stronger than without POM in summer. (3) The aerosol optical depth (AOD) simulated by RIEMS 2.0 with POM is larger in the middle and lower reaches of the Yangtze River than without POM. (4) The direct radiative effect with POM is stronger than that without POM in the middle and lower reaches of the Yangtze River and parts of southern China. Therefore, the authors should take account of the impact of the regional ocean model on studying the direct climate effect &aerosols in long term simulation.展开更多
The resistivity of Hg<sub>0.89</sub>Mn<sub>0.11</sub>Te has been measured by the superconducting quantum interference device magnetometer in the temperature range from 5 to 200 K under the appl...The resistivity of Hg<sub>0.89</sub>Mn<sub>0.11</sub>Te has been measured by the superconducting quantum interference device magnetometer in the temperature range from 5 to 200 K under the applied magnetic field of 1, 2, 4 and 6.5 Tesla, respectively, compared with that of no-magnetic field. The results show that the resistivity increases with increase applied magnetic field at higher temperature from 80 to 200 K, but decreases at lower temperature from 5 to 25 K. There exists a transitive range from 25 to 80 K, where the variation of the resistivity shows different tendencies depending on the strength of magnetic field. Maximum difference of resistivity under 6.5 Tesla from that without magnetic field in the temperature range from 30 to 200 K is only about 5 Ω·cm, but it increases up to 3 orders of magnitude at 5 K. The analysis shows that the variation of resistivity of Hg<sub>0.89</sub>Mn<sub>0.11</sub>Te under the magnetic field is the algebraic sum of the transverse direction magnetoresistance effect and the sp-d exchange interaction effect. TDRME plays major role in the high temperature range. However, with the decrease of temperature, the effect of sp-d EI on the resistivity gradually exceeds that of the transverse direction magnetoresistance effect through the transitive range, and becomes the dominant effect in the temperature range from 5 to 25 K, which leads to the dramatic decrease of resistivity.展开更多
Current global climate models cannot resolve the complex topography over the Tibetan Plateau(TP)due to their coarse resolution.This study investigates the impacts of horizontal resolution on simulating aerosol and its...Current global climate models cannot resolve the complex topography over the Tibetan Plateau(TP)due to their coarse resolution.This study investigates the impacts of horizontal resolution on simulating aerosol and its direct radiative effect(DRE)over the TP by applying two horizontal resolutions of about 100 km and 25 km to the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere Land System(CAS FGOALS-f3)over a 10-year period.Compared to the AErosol RObotic NETwork observations,a high-resolution model(HRM)can better reproduce the spatial distribution and seasonal cycles of aerosol optical depth(AOD)compared to a low-resolution model(LRM).The HRM bias and RMSE of AOD decreased by 0.08 and 0.12,and the correlation coefficient increased by 0.22 compared to the LRM.An LRM is not sufficient to reproduce the aerosol variations associated with fine-scale topographic forcing,such as in the eastern marginal region of the TP.The difference between hydrophilic aerosols in an HRM and LRM is caused by the divergence of the simulated relative humidity(RH).More reasonable distributions and variations of RH are conducive to simulating hydrophilic aerosols.An increase of the 10-m wind speed in winter by an HRM leads to increased dust emissions.The simulated aerosol DREs at the top of the atmosphere(TOA)and at the surface by the HRM are–0.76 W m^(–2)and–8.72 W m^(–2)over the TP,respectively.Both resolution models can capture the key feature that dust TOA DRE transitions from positive in spring to negative in the other seasons.展开更多
The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor...The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor couplings of vector mesons ω and ρ on the nucleonic direct URCA processes. It is found that the inclusion of the tensor couplings of vector mesons w and p can slightly increase the maximum mass of neutron stars. In addition, the results indicate that the tensor couplings of vector mesons ω and ρ lead to obvious enhancement of the total neutrino emissivity for the nucleonic direct URCA processes, which must accelerate the cooling rate of the non- superfluid neutron star matter. However, when considering only the tensor coupling of vector meson ρ, the neutrino emissivity for the nucleonic direct URCA processes slightly declines at low densities and significantly increases at high densities. That is, the tensor coupling of vector meson ρ leads to the slow cooling rate of a low-mass neutron star and rapid cooling rate of a massive neutron star.展开更多
It was found for the first time that the compounds with only one functional group, such as pyridine, can show the promotion effect for the electrochemical reaction of cytochrome C at gold electrodes.
Studies of direction of photoisomerization of retinal,retinonitrile,a- retinonitrile and a trienenitrile analog in different solvents with varying wave- lengths of excitation and reaction temperature led to the conclu...Studies of direction of photoisomerization of retinal,retinonitrile,a- retinonitrile and a trienenitrile analog in different solvents with varying wave- lengths of excitation and reaction temperature led to the conclusion that the well known solvent dependent photochemistry of retinoids is due to selective excitation of the hydrogen bonded species.展开更多
The main function of basic rights is to defend against the state’s public power.the traditional theory of basic rights con-structs logic based on the dualistic framework of“state power and individual rights,”and de...The main function of basic rights is to defend against the state’s public power.the traditional theory of basic rights con-structs logic based on the dualistic framework of“state power and individual rights,”and deals with the dualistic horizontal relationship between“the state and individuals.”However,the increasing com-plexity of modern society has led to the emergence of different inter-ests and needs within society and the formation of new social powers,resulting in an unequal relationship between private subjects.In the digital era,this phenomenon has become particularly prominent,ev-idenced by the rise of data-based power and the frequent and serious intrusion of personal information by private subjects.In this context,the value of basic rights should radiate within society and function as a balancing force.taking the protection of personal information as an example,while innovating the idea of regulating society through basic rights,the state’s obligation to protect personal information should be further strengthened.Meanwhile,the direct effect of personal infor-mation rights,which are basic human rights,on the private subjects of data-based power should be established,so as to realize their function in balancing the interests of all parties in society.展开更多
Despite experiencing a decadal shift towards drought conditions at the end of the 2Oth century,semiarid grasslands in northeast Asia(NEA)exhibited an evident greening trend from 1982 to 2020.However,the mechanism behi...Despite experiencing a decadal shift towards drought conditions at the end of the 2Oth century,semiarid grasslands in northeast Asia(NEA)exhibited an evident greening trend from 1982 to 2020.However,the mechanism behind this phenomenon remains unclear.Hence,we analysed the interdecadal changes in vegetation response to drought on the basis of the standardised precipitation evapotranspiration index(SPEI)and Global Inventory Modelling and Mapping Studies LAI4g datasets,with an emphasis on the differences between direct and legacy effects(as measured by resilience),to explore the mechanism of persistent grassland greening.Results revealed that during the post-drought shift period(2000-2020),the sudden decrease in the water content of the intermediate soil layer triggered an intensified vegetation response to drought.Specifically,although direct effects and resilience were amplified,they exhibited asymmetric changes.Resilience was stronger than direct effects,and this difference increased with increasing drought(drought recovery)levels.These combined effects may account for persistent greening against intensified drying in the semiarid grasslands in NEA.Given the projected exacerbation of future droughts,this study holds notable importance for comprehending the long-term change dynamics of dryland ecosystems.展开更多
Ground motions with forward-directivity effect in the near-fault region are obviously different from ordinary far-field ground motions. Design spectral models for this kind of motions have been proposed by correlating...Ground motions with forward-directivity effect in the near-fault region are obviously different from ordinary far-field ground motions. Design spectral models for this kind of motions have been proposed by correlating simple pulses with parameters attenuation relationships in a previous study of the authors. To further test the applica- bility of the established design spectral model, we analyze ground motion pseudo-velocity response spectra (PVS), normalized pseudo-velocity spectra (NPVS) and bi-normalized pseudo-velocity spectra (BNPVS) of 53 typical near-fault forward-directivity ground motions. It is found that BNPVS not only has more salient features to reflect the difference between soil and rock sites, but also has less scattering to reveal the nature of forward-directivity motions. And then, BNPVS is used for prediction of design spectra accounting for the influence of site conditions, and the constructed design spectra are compared with those spectra established previously. It is concluded that site condition can heavily affect ground motions, buildings on rock can be even more dangerous than those on soil sites, in particular for ordinary buildings with short to middle vibration periods. Finally, pulse models are also suggested for structural analyses in the near-fault region.展开更多
The frequency content of earthquake ground motion is very important because it affects the dynamic response of structural systems. In the paper, we use five scalar parameters (the response spectral predominant period ...The frequency content of earthquake ground motion is very important because it affects the dynamic response of structural systems. In the paper, we use five scalar parameters (the response spectral predominant period Tp, smoothed spectral predominant period To, Fourier amplitude spectral mean period Tm, equivalent pulse period Tv, and the pseudo-velocity spectral predominant period Tpv) reflecting the characteristics of frequency content of strong ground motion to examine the near-fault three-component motions during the 1999 Chi-Chi earthquake. The result indicates that the frequency content of near-fault motions at the Hanging wall is less than that at the foot wall; Tp shows a smaller value than that of To and Tm and it emerges a reverse relation of three-component motions as compared with that of To and Tm; Tv and Tpv of the near-fault motions at the north end of the rupture display a similar trend to that generated by the rupture directivity effect of strike-slip faulting. We therefore conclude that these observations are useful in the formulation of near-fault design spectra for seismic codes and in zoning studies in seismic risk.展开更多
On the basis of previous study of the 1679 Sanhe-Pinggu(M8.0) earthquake,the biggest event in history ever recorded in Beijing and its adjacent area,we made a 3-D strong ground motion simulation utilizing the staggere...On the basis of previous study of the 1679 Sanhe-Pinggu(M8.0) earthquake,the biggest event in history ever recorded in Beijing and its adjacent area,we made a 3-D strong ground motion simulation utilizing the staggered-grid finite differences method to study the distributions of peak ground velocity with different earthquake source models in the Beijing region.In the paper,earthquake source models and a transmission medium velocity model are established and the corresponding parameters are given in accordance to the results from a related previous study.Then,using a three-dimensional finite difference computing program of near-fault strong ground motion developed by Graves,the peak ground velocity caused by a destructive earthquake in the Beijing area is simulated.In our computation model,the earthquake source is 3km in depth,and a total number of 21,679 observation points on the ground surface are figured out.The transmission medium velocity model is composed of four stratums which are the Quaternary deposit,the upper crust,the upper part of the middle crust and the lower part of the middle crust.With the minimum grid spacing of 0.15km,a total of 2.28×106 grids are generated.Using a time step of 0.02 seconds we calculated the peak ground velocity for a duration of 8 seconds.After the analysis of the simulation results,we observed some basic characteristics of near-fault strong ground motion such as the concentration effect of near-fault peak ground velocity,rupture directivity effect,hanging wall effect,and basin effect.The results from our simulation and analysis suggest that the source and transmitting medium parameters in our model are suitable and the finite difference method is applicable to estimate the distribution of strong ground motion in the study region.展开更多
The M_S8.0 Wenchuan earthquake in Sichuan caused heavy casualties and serious economic loss because of damage to engineering structures in high earthquake intensity regions. Earthquake intensity, especially in the nea...The M_S8.0 Wenchuan earthquake in Sichuan caused heavy casualties and serious economic loss because of damage to engineering structures in high earthquake intensity regions. Earthquake intensity, especially in the near source region, as a macroscopic description of distribution of strong ground motions certain correlations with the earthquake source process, such as rupture directivity and the hanging-wall effect of the near-fault ground motions of this earthquake. In this article some qualitative analyses are carried out. The conclusion of this study may be useful for emergence response and rescue after earthquakes, when the strong ground motion recordings and the intensity distribution are not available immediately.展开更多
The 5.12 Wenchuan Earthquake in 2008 induced hundreds of large-scale landslides. This paper systematically analyzes 112 large-scale landslides (surface area > 50000 m2), which were identified by interpretation of r...The 5.12 Wenchuan Earthquake in 2008 induced hundreds of large-scale landslides. This paper systematically analyzes 112 large-scale landslides (surface area > 50000 m2), which were identified by interpretation of remote sensing imagery and field investigations. The analysis suggests that the distribution of large-scale landslides is affected by the following four factors: (a) distance effect: 80% of studied large-scale landslides are located within a distance of 5 km from the seismic faults. The farther the distance to the faults, the lower the number of large-scale landslides; (b) locked segment effect: the large-scale landslides are mainly located in five concentration zones closely related with the crossing, staggering and transfer sections between one seismic fault section and the next one, as well as the end of the NE fault section. The zone with the highest concentration was the Hongbai-Chaping segment, where a great number of large-scale landslides including the two largest landslides were located. The second highest concentration of large-scale landslides was observed in the Nanba-Donghekou segment at the end of NE fault, where the Donghekou landslide and the Woqian landslide occurred; (c) Hanging wall effect: about 70% of the large-scale landslides occurred on the hanging wall of the seismic faults; and (d) direction effect: in valleys perpendicular to the seismic faults, the density of large-scale landslides on the slopes facing the seismic wave is obviously higher than that on the slopes dipping in the same direction as the direction of propagation of the seismic wave. Meanwhile, it is found that the sliding and moving directions of large-scale landslides are related to the staggering direction of the faults in each section. In Qingchuan County where the main fault activity was horizontal twisting and staggering, a considerable number of landslides showed the feature of sliding and moving in NE direction which coincides with the staggering direction of the seismic faults.展开更多
文摘Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is estimated that in the scenario of activation of the North Tehran fault, many structures in Tehran will collapse. Therefore, it is necessary to incorporate the near field rupture directivity effects of this fault into the seismic hazard assessment of important sites in Tehran. In this study, using calculations coded in MATLAB, Probabilistic Seismic Hazard Analysis (PSHA) is conducted for an important site in Tehran. Following that, deaggregation technique is performed on PSHA and the contribution of seis- mic scenarios to hazard is obtained in the range of distance and magnitude. After identifying the North Tehran fault as the most hazardous source affecting the site in 10000-year return period, rupture directivity effects of this fault is incorporated into the seismic hazard assessment using Somerville et al. (1997) model with broadband approach and Shahi and Baker (2011) model with narrowband approach. The results show that the narrowband approach caused a 27% increase in the peak of response spectrum in 10000-year return period compared with the conventional PSHA. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.
文摘Objective:To investigate the inhibitory effect of curcumin on influenza virus HIN1 and H3N2 in vitro, Methods:The directly killing role of cureumin extract in vitro to influenza virus type A subtype H1N1 and H3N2 was evaluated by the canine kidney cells (MDCK), Results:The largest non toxic concentration of curcumin extract was 12, 5g/L and the effective inhibitory concentration to H1N1 and H3N2 was 6, 25G/1 AND 1,56g/L respectively, Conclusion: Curcumin extract have directly killing effect on H1N1 and H3N2 infections.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KZCX2-YW-Q11-03)the"Strategic Priority Research Program"of the Chinese Academy of Sciences(Grant No. XDA05100502)+1 种基金the National Basic Research Program of China (Grant No.2010CB950804)100 Talents Program of the Chinese Academy of Sciences
文摘The direct climatic effect of aerosols for the 1980-2000 period over East Asia was numerically investigated by a regional scale coupled climate-chemistry/ aerosol model, which includes major anthropogenic aerosols (sulfate, black carbon, and organic carbon) and natural aerosols (soil dust and sea salt). Anthropogenic emissions used in model simulation are from a global emission inventory prepared for the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5), whereas natural aerosols are calculated online in the model. The simulated 20-year average direct solar radiative effect due to aerosols at the surface was estimated to be in a range of-9- -33 W m-2 over most areas of China, with maxima over the Gobi desert of West China, and-12 W m-2 to -24 W m-2 over the Sichuan Basin, the middle and lower reaches of the Yellow River and the Yangtze River. Aerosols caused surface cooling in most areas of East Asia, with maxima of-0.8℃ to -1.6℃ over the deserts of West China, the Sichuan Basin, portions of central China, and the middle reaches of the Yangtze River. Aerosols induced a precipitation decrease over almost the entire East China, with maxima of-90 mm/year to -150 mm/year over the Sichuan Basin, the middle reaches of the Yangtze River and the lower reaches of the Yellow River. Interdecadal variation of the climate response to the aerosol direct radiative effect is evident, indicating larger decrease in surface air temperature and stronger per- turbation to precipitation in the 1990s than that in the 1980s, which could be due to the interdecadal variation of anthropogenic emissions.
基金supported by the Key Project of Chinese Academy of Sciences under Grant KZCX2-YW-Q11-03supported by the National Basic Research Program of China ("973" program) under Grant2006CB403705+1 种基金the Key Project of Chinese Academy of Sciences under Grants KZCX2-YW-Q1-02, KZCX2-YW-205, and KZCX2-YW-219the National Natural Science Foundation of China under Grant No. 40631005
文摘Direct climate responses to dust shortwave and longwave radiative forcing (RF) are studied using the NCAR Community Atmosphere Model Version 3 (CAM3). The simulated RF at the top of the atmosphere (TOA) is-0.45 W m-2 in the solar spectrum and +0.09 W m-2 in the thermal spectrum on a global average. The magnitude of surface RF is larger than the TOA forcing, with global mean shortwave forcing of-1.76 W m-2 and longwave forcing of +0.31 W m-2 . As a result, dust aerosol causes the absorption of 1.1 W m-2 in the atmosphere. The RF of dust aerosol is predicted to lead to a surface cooling of 0.5 K over the Sahara Desert and Arabian Peninsula. In the meantime, the upper troposphere is predicted to become warmer because of the absorption by dust. These changes in temperature lead to a more stable atmosphere, which results in increases in surface humidity. The upward sensible and latent heat fluxes at the surface are reduced, largely balancing the surface energy loss caused by the backscattering and absorption of dust aerosol. Precipitation is predicted to decrease moderately on a global scale.
基金supported by the National Basic Research Program of China(973 program,Grant 2010CB951901)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant XDA05100503)
文摘The authors examine the equilibrium climatic response to the direct radiative effect (DRE) of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions.In response to the drier and windier conditions,dust emissions increase by 26% in the Sahara Desert and by 18% on the global scale relative to present day.Sea salt emissions increase in high latitudes (>60°) but decrease in middle latitudes (30°-60°) of both hemispheres due to the poleward shift of westerlies,leading to a 3% decrease in global emissions.The burdens of dust and sea salt increase by 31% and 7% respectively,because reductions in rainfall over the tropical oceans increase the lifetime of particles in the warmer climate.The higher aerosol loading in the doubled-CO2 climate reinforces aerosol DRE by -0.2 W m-2,leading to an additional cooling of 0.1℃ at the surface compared with the climatic effects of aerosols in present day.The additional cooling from changes in natural aerosols compensates for up to 15% of the regional warming induced by doubled CO2.
文摘The estimate of seismic site effects by experimental approaches is based on different assumptions aimed at simplifying the complex actual site conditions and related uncertainties.However,the reliability of the results can increase if the experimental data is focused on quite strong seismic sequences and the on-site acquisition of a large number of signals is deemed strategic for the assessment of the expected phenomena.Based on these considerations,the ground motion at the Red Zone sector of Amatrice hill,violently struck by the 2016-2017 Central Italy seismic sequence,was analyzed via an observational approach.A large set of weak motions(moment magnitude Mw 2.5-3.9)was analyzed in this study by means of standard(SSR)and horizontal to vertical(HVSR)spectral ratio techniques.The results from the experimental analysis of the site effects by using weak motion and noise signals show a significant amplification at the top of Amatrice hill with a remarkable polarization of the motion and changes in spectral shapes according to the topographic setting of the relief.
文摘Direct piezoelectricity of electro-active papers (EAPap) is analysed in this paper. The test setups for direct effect are designed and determined. Different ambient factors impacting the piezoelectricity of EAPap, such as temperature, humidity, and strain rate, are applied and analyzed. Strong piezoelectricity of EAPap is found on the basis of the test results and in comparison with polyvinylidene fluoride (PVDF) and lead zirconate titanate (PZT)-5H. The maximum piezoelectric constant is achieved to be 504 pC/N. The reason of strong piezoelectricity of EAPap is discussed in this paper. The potential of EAPap as a biomimetic actuator and sensor is also investigated.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KZCX2-YW-Q11-03)the National Basic Research Program of China(Grant Nos.2010CB950900 and 2009CB421100)+1 种基金the National Natural Science Foundation of China(Grant No. 91025003)the R&D Special Fund for Public Welfare Industry (Meteorology)(Grant No.GYHY200906020)
文摘The Regional Integrated Environmental Model System (RIEMS 2.0) coupled with a chemistry-aerosol model and the Princeton Ocean Model (POM) is employed to simulate regional oceanic impact on atmospheric circulation and the direct radiative effect (DRE) of aerosol over East Asia. The aerosols considered in this study include both major anthropogenic aerosols (e.g., sulfate, black carbon, and organic carbon) and natural aerosols (e.g., soil dust and sea salt). The RIEMS 2.0 is driven by NCEP/NCAR reanalysis II, and the simulated period is from 1 January to 31 December 2006. The results show the following: (1) The simulated annual mean sea-level pressure by RIEMS 2.0 with POM is lower than without POM over the mainland and higher without POM over the ocean. (2) In summer, the subtropical high simulated by RIEMS 2.0 with POM is stronger and extends further westward, and the continental low is stronger than without POM in summer. (3) The aerosol optical depth (AOD) simulated by RIEMS 2.0 with POM is larger in the middle and lower reaches of the Yangtze River than without POM. (4) The direct radiative effect with POM is stronger than that without POM in the middle and lower reaches of the Yangtze River and parts of southern China. Therefore, the authors should take account of the impact of the regional ocean model on studying the direct climate effect &aerosols in long term simulation.
基金Supported by the National Natural Science Foundation of China(No.50336040)
文摘The resistivity of Hg<sub>0.89</sub>Mn<sub>0.11</sub>Te has been measured by the superconducting quantum interference device magnetometer in the temperature range from 5 to 200 K under the applied magnetic field of 1, 2, 4 and 6.5 Tesla, respectively, compared with that of no-magnetic field. The results show that the resistivity increases with increase applied magnetic field at higher temperature from 80 to 200 K, but decreases at lower temperature from 5 to 25 K. There exists a transitive range from 25 to 80 K, where the variation of the resistivity shows different tendencies depending on the strength of magnetic field. Maximum difference of resistivity under 6.5 Tesla from that without magnetic field in the temperature range from 30 to 200 K is only about 5 Ω·cm, but it increases up to 3 orders of magnitude at 5 K. The analysis shows that the variation of resistivity of Hg<sub>0.89</sub>Mn<sub>0.11</sub>Te under the magnetic field is the algebraic sum of the transverse direction magnetoresistance effect and the sp-d exchange interaction effect. TDRME plays major role in the high temperature range. However, with the decrease of temperature, the effect of sp-d EI on the resistivity gradually exceeds that of the transverse direction magnetoresistance effect through the transitive range, and becomes the dominant effect in the temperature range from 5 to 25 K, which leads to the dramatic decrease of resistivity.
基金supported by the National Natural Science Funds of China(Grant Nos.41875133,91937302)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA2006010302)+2 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(STEP,Grant No.2019QZKK0206)the Youth Innovation Promotion Association CAS(2020078)the International Partnership Program of Chinese Academy of Sciences(Grant No.134111KYSB20200006).
文摘Current global climate models cannot resolve the complex topography over the Tibetan Plateau(TP)due to their coarse resolution.This study investigates the impacts of horizontal resolution on simulating aerosol and its direct radiative effect(DRE)over the TP by applying two horizontal resolutions of about 100 km and 25 km to the Chinese Academy of Sciences Flexible Global Ocean-Atmosphere Land System(CAS FGOALS-f3)over a 10-year period.Compared to the AErosol RObotic NETwork observations,a high-resolution model(HRM)can better reproduce the spatial distribution and seasonal cycles of aerosol optical depth(AOD)compared to a low-resolution model(LRM).The HRM bias and RMSE of AOD decreased by 0.08 and 0.12,and the correlation coefficient increased by 0.22 compared to the LRM.An LRM is not sufficient to reproduce the aerosol variations associated with fine-scale topographic forcing,such as in the eastern marginal region of the TP.The difference between hydrophilic aerosols in an HRM and LRM is caused by the divergence of the simulated relative humidity(RH).More reasonable distributions and variations of RH are conducive to simulating hydrophilic aerosols.An increase of the 10-m wind speed in winter by an HRM leads to increased dust emissions.The simulated aerosol DREs at the top of the atmosphere(TOA)and at the surface by the HRM are–0.76 W m^(–2)and–8.72 W m^(–2)over the TP,respectively.Both resolution models can capture the key feature that dust TOA DRE transitions from positive in spring to negative in the other seasons.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11447165,11373047 and 11265009the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2016056
文摘The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor couplings of vector mesons ω and ρ on the nucleonic direct URCA processes. It is found that the inclusion of the tensor couplings of vector mesons w and p can slightly increase the maximum mass of neutron stars. In addition, the results indicate that the tensor couplings of vector mesons ω and ρ lead to obvious enhancement of the total neutrino emissivity for the nucleonic direct URCA processes, which must accelerate the cooling rate of the non- superfluid neutron star matter. However, when considering only the tensor coupling of vector meson ρ, the neutrino emissivity for the nucleonic direct URCA processes slightly declines at low densities and significantly increases at high densities. That is, the tensor coupling of vector meson ρ leads to the slow cooling rate of a low-mass neutron star and rapid cooling rate of a massive neutron star.
基金The project is supported by National Natural Science Foundation of China
文摘It was found for the first time that the compounds with only one functional group, such as pyridine, can show the promotion effect for the electrochemical reaction of cytochrome C at gold electrodes.
文摘Studies of direction of photoisomerization of retinal,retinonitrile,a- retinonitrile and a trienenitrile analog in different solvents with varying wave- lengths of excitation and reaction temperature led to the conclusion that the well known solvent dependent photochemistry of retinoids is due to selective excitation of the hydrogen bonded species.
基金the national major project of social sciences“Research on Chinese Characteristics and System Construction of the Constitution Implementation Guarantee Mechanism”(Project Approval No.20ZDA030)the Ministry of Education Humanities and Social Science Key Base major project“New Development of Human Rights and Basic Rights in the Context of a New Era of Smart Society”(Project Approval No.19JJD820011)。
文摘The main function of basic rights is to defend against the state’s public power.the traditional theory of basic rights con-structs logic based on the dualistic framework of“state power and individual rights,”and deals with the dualistic horizontal relationship between“the state and individuals.”However,the increasing com-plexity of modern society has led to the emergence of different inter-ests and needs within society and the formation of new social powers,resulting in an unequal relationship between private subjects.In the digital era,this phenomenon has become particularly prominent,ev-idenced by the rise of data-based power and the frequent and serious intrusion of personal information by private subjects.In this context,the value of basic rights should radiate within society and function as a balancing force.taking the protection of personal information as an example,while innovating the idea of regulating society through basic rights,the state’s obligation to protect personal information should be further strengthened.Meanwhile,the direct effect of personal infor-mation rights,which are basic human rights,on the private subjects of data-based power should be established,so as to realize their function in balancing the interests of all parties in society.
基金supported by the National Natural Science Foundation of China (42021004).
文摘Despite experiencing a decadal shift towards drought conditions at the end of the 2Oth century,semiarid grasslands in northeast Asia(NEA)exhibited an evident greening trend from 1982 to 2020.However,the mechanism behind this phenomenon remains unclear.Hence,we analysed the interdecadal changes in vegetation response to drought on the basis of the standardised precipitation evapotranspiration index(SPEI)and Global Inventory Modelling and Mapping Studies LAI4g datasets,with an emphasis on the differences between direct and legacy effects(as measured by resilience),to explore the mechanism of persistent grassland greening.Results revealed that during the post-drought shift period(2000-2020),the sudden decrease in the water content of the intermediate soil layer triggered an intensified vegetation response to drought.Specifically,although direct effects and resilience were amplified,they exhibited asymmetric changes.Resilience was stronger than direct effects,and this difference increased with increasing drought(drought recovery)levels.These combined effects may account for persistent greening against intensified drying in the semiarid grasslands in NEA.Given the projected exacerbation of future droughts,this study holds notable importance for comprehending the long-term change dynamics of dryland ecosystems.
基金China Science Foundation of Postdoctoral Program (20060400826)China National Science Foundation of the International (Regional) Cooperative Research Program (50420120133).
文摘Ground motions with forward-directivity effect in the near-fault region are obviously different from ordinary far-field ground motions. Design spectral models for this kind of motions have been proposed by correlating simple pulses with parameters attenuation relationships in a previous study of the authors. To further test the applica- bility of the established design spectral model, we analyze ground motion pseudo-velocity response spectra (PVS), normalized pseudo-velocity spectra (NPVS) and bi-normalized pseudo-velocity spectra (BNPVS) of 53 typical near-fault forward-directivity ground motions. It is found that BNPVS not only has more salient features to reflect the difference between soil and rock sites, but also has less scattering to reveal the nature of forward-directivity motions. And then, BNPVS is used for prediction of design spectra accounting for the influence of site conditions, and the constructed design spectra are compared with those spectra established previously. It is concluded that site condition can heavily affect ground motions, buildings on rock can be even more dangerous than those on soil sites, in particular for ordinary buildings with short to middle vibration periods. Finally, pulse models are also suggested for structural analyses in the near-fault region.
基金Heilongjiang Natural Science Frundation Project (ZGJ03-03)the Researth Fund for the Doctoral Program of Higher Education of China (20030213042).
文摘The frequency content of earthquake ground motion is very important because it affects the dynamic response of structural systems. In the paper, we use five scalar parameters (the response spectral predominant period Tp, smoothed spectral predominant period To, Fourier amplitude spectral mean period Tm, equivalent pulse period Tv, and the pseudo-velocity spectral predominant period Tpv) reflecting the characteristics of frequency content of strong ground motion to examine the near-fault three-component motions during the 1999 Chi-Chi earthquake. The result indicates that the frequency content of near-fault motions at the Hanging wall is less than that at the foot wall; Tp shows a smaller value than that of To and Tm and it emerges a reverse relation of three-component motions as compared with that of To and Tm; Tv and Tpv of the near-fault motions at the north end of the rupture display a similar trend to that generated by the rupture directivity effect of strike-slip faulting. We therefore conclude that these observations are useful in the formulation of near-fault design spectra for seismic codes and in zoning studies in seismic risk.
基金This project was sponsored by the National Development and Reform Commission,PRC(20041138)
文摘On the basis of previous study of the 1679 Sanhe-Pinggu(M8.0) earthquake,the biggest event in history ever recorded in Beijing and its adjacent area,we made a 3-D strong ground motion simulation utilizing the staggered-grid finite differences method to study the distributions of peak ground velocity with different earthquake source models in the Beijing region.In the paper,earthquake source models and a transmission medium velocity model are established and the corresponding parameters are given in accordance to the results from a related previous study.Then,using a three-dimensional finite difference computing program of near-fault strong ground motion developed by Graves,the peak ground velocity caused by a destructive earthquake in the Beijing area is simulated.In our computation model,the earthquake source is 3km in depth,and a total number of 21,679 observation points on the ground surface are figured out.The transmission medium velocity model is composed of four stratums which are the Quaternary deposit,the upper crust,the upper part of the middle crust and the lower part of the middle crust.With the minimum grid spacing of 0.15km,a total of 2.28×106 grids are generated.Using a time step of 0.02 seconds we calculated the peak ground velocity for a duration of 8 seconds.After the analysis of the simulation results,we observed some basic characteristics of near-fault strong ground motion such as the concentration effect of near-fault peak ground velocity,rupture directivity effect,hanging wall effect,and basin effect.The results from our simulation and analysis suggest that the source and transmitting medium parameters in our model are suitable and the finite difference method is applicable to estimate the distribution of strong ground motion in the study region.
基金funded by basic research fund programs DQJB08B02 and DQJB06A01 of state-level public welfare scientific research institutions of Institute of Geophysics,CEA
文摘The M_S8.0 Wenchuan earthquake in Sichuan caused heavy casualties and serious economic loss because of damage to engineering structures in high earthquake intensity regions. Earthquake intensity, especially in the near source region, as a macroscopic description of distribution of strong ground motions certain correlations with the earthquake source process, such as rupture directivity and the hanging-wall effect of the near-fault ground motions of this earthquake. In this article some qualitative analyses are carried out. The conclusion of this study may be useful for emergence response and rescue after earthquakes, when the strong ground motion recordings and the intensity distribution are not available immediately.
基金sponsored by the project of the Chinese National Key Basic Research Program on "The failure mechanism and distribution rule of slopes under strong earthquakes" (Grant No. 2008CB425801)the Education Department Innovation Research Team Program (Grant No. IRT0812)
文摘The 5.12 Wenchuan Earthquake in 2008 induced hundreds of large-scale landslides. This paper systematically analyzes 112 large-scale landslides (surface area > 50000 m2), which were identified by interpretation of remote sensing imagery and field investigations. The analysis suggests that the distribution of large-scale landslides is affected by the following four factors: (a) distance effect: 80% of studied large-scale landslides are located within a distance of 5 km from the seismic faults. The farther the distance to the faults, the lower the number of large-scale landslides; (b) locked segment effect: the large-scale landslides are mainly located in five concentration zones closely related with the crossing, staggering and transfer sections between one seismic fault section and the next one, as well as the end of the NE fault section. The zone with the highest concentration was the Hongbai-Chaping segment, where a great number of large-scale landslides including the two largest landslides were located. The second highest concentration of large-scale landslides was observed in the Nanba-Donghekou segment at the end of NE fault, where the Donghekou landslide and the Woqian landslide occurred; (c) Hanging wall effect: about 70% of the large-scale landslides occurred on the hanging wall of the seismic faults; and (d) direction effect: in valleys perpendicular to the seismic faults, the density of large-scale landslides on the slopes facing the seismic wave is obviously higher than that on the slopes dipping in the same direction as the direction of propagation of the seismic wave. Meanwhile, it is found that the sliding and moving directions of large-scale landslides are related to the staggering direction of the faults in each section. In Qingchuan County where the main fault activity was horizontal twisting and staggering, a considerable number of landslides showed the feature of sliding and moving in NE direction which coincides with the staggering direction of the seismic faults.