In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occ...In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occurrences. The multifaceted nature of these influences makes the surveillance of mass movements a highly intricate task, requiring an understanding of numerous interdependent variables. Recent years have seen an emergence in scholarly research aimed at integrating geophysical and geotechnical methodologies. The conjoint examination of geophysical and geotechnical data offers an enhanced perspective into subsurface structures. Within this work, a methodology is proposed for the synchronous analysis of electrical resistivity geophysical data and geotechnical data, specifically those extracted from the Light Dynamic Penetrometer (DPL) and Standard Penetration Test (SPT). This study involved a linear fitting process to correlate resistivity with N10/SPT N-values from DPL/SPT soundings, culminating in a 2D profile of N10/SPT N-values predicated on electrical profiles. The findings of this research furnish invaluable insights into slope stability by allowing for a two-dimensional representation of penetration resistance properties. Through the synthesis of geophysical and geotechnical data, this project aims to augment the comprehension of subsurface conditions, with potential implications for refining landslide risk evaluations. This endeavor offers insight into the formulation of more effective and precise slope management protocols and disaster prevention strategies.展开更多
Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase b...Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase both in the use and application of the in situ tests: cone penetration test(CPT) and dynamic probing(DP). Several empirical SPT-CPT and dynamic probing light(DPL)-CPT correlations for sandy soils have been discussed in the literature. New SPT-CPT and DPL-CPT correlations for the sandy soils of the city of Vitoria, in the southeast of Brazil, are suggested in this paper. Statistical analyses to evaluate the quality of the data used are performed, and the suggested correlations are validated with several previous published datasets. The paper also provides some insights into SPT-CPT correlations and soil characteristics(i.e. the mean particle size and the fines fraction of the soil).展开更多
Vortex beams with fractional topological charge(FTC) have many special characteristics and novel applications.However, one of the obstacles for their application is the difficulty of precisely determining the FTC of f...Vortex beams with fractional topological charge(FTC) have many special characteristics and novel applications.However, one of the obstacles for their application is the difficulty of precisely determining the FTC of fractional vortex beams. We find that when a vortex beam with an FTC illuminates a dynamic angular double slit(ADS), the far-field interference patterns that include the information of the FTC of the beam at the angular bisector direction of the ADS vary periodically. Based on this property, a simple dynamic ADS device and data fitting method can be used to precisely measure the FTC of a vortex light beam with an error of less than 5%.展开更多
Photodynamics of peripheral antenna complexes,light-harvesting complex (LH2) of Rhodobacter (Rb) Sphaeroides 601,was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results ...Photodynamics of peripheral antenna complexes,light-harvesting complex (LH2) of Rhodobacter (Rb) Sphaeroides 601,was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results reveal dramatic dynamical evolutions within B800 and B850 absorption bands of antenna complexes LH2. At excitation wavelength around 835 nm,a sharp photobleaching signal was observed which was assigned to the contribution of the two-exciton state,which was further confirmed by the power dependence measurement. Rate equations with eight-level scheme were used to calculate the population evolution in LH2 and the transient dynamics under femtosecond pulse excitation. The research results prove that not only the transition from ground state to one-exciton state but also that from one-exciton state to two-exciton state contribute to the photodynamics of B850.展开更多
Ultrafast spectroscopy of semiconductor saturable absorber mirror （SESAM） is measured using a femtosec- ond pump-probe experiment. This allows dynamic responses of SESAM in the cavity to be concluded by ultrafast sp...Ultrafast spectroscopy of semiconductor saturable absorber mirror （SESAM） is measured using a femtosec- ond pump-probe experiment. This allows dynamic responses of SESAM in the cavity to be concluded by ultrafast spectroscopy. Change in reflection is measured as a function of pump-probe delay for different pump excitation fluences. Change of nonlinear reflection of SESAM is measured as a function of incident light energy density. When the excitation fluence increases, nonlinear change in ultrafast spectroscopy of SESAM becomes increasingly significant. When SESAM is pumped by an ultrahigh excitation fluence, the energy density of which is approximately 1400 μJ/cm2, two-photon absorption can be observed visibly in its ultrafast spectroscopy.展开更多
文摘In Brazil and various regions globally, the initiation of landslides is frequently associated with rainfall;yet the spatial arrangement of geological structures and stratification considerably influences landslide occurrences. The multifaceted nature of these influences makes the surveillance of mass movements a highly intricate task, requiring an understanding of numerous interdependent variables. Recent years have seen an emergence in scholarly research aimed at integrating geophysical and geotechnical methodologies. The conjoint examination of geophysical and geotechnical data offers an enhanced perspective into subsurface structures. Within this work, a methodology is proposed for the synchronous analysis of electrical resistivity geophysical data and geotechnical data, specifically those extracted from the Light Dynamic Penetrometer (DPL) and Standard Penetration Test (SPT). This study involved a linear fitting process to correlate resistivity with N10/SPT N-values from DPL/SPT soundings, culminating in a 2D profile of N10/SPT N-values predicated on electrical profiles. The findings of this research furnish invaluable insights into slope stability by allowing for a two-dimensional representation of penetration resistance properties. Through the synthesis of geophysical and geotechnical data, this project aims to augment the comprehension of subsurface conditions, with potential implications for refining landslide risk evaluations. This endeavor offers insight into the formulation of more effective and precise slope management protocols and disaster prevention strategies.
基金the sponsorship from the Brazilian government agencies CNPqFAPES
文摘Field tests in geotechnical engineering are fundamental for identification of the underground conditions.The standard penetration test(SPT) is the most commonly used geotechnical approach. There has been an increase both in the use and application of the in situ tests: cone penetration test(CPT) and dynamic probing(DP). Several empirical SPT-CPT and dynamic probing light(DPL)-CPT correlations for sandy soils have been discussed in the literature. New SPT-CPT and DPL-CPT correlations for the sandy soils of the city of Vitoria, in the southeast of Brazil, are suggested in this paper. Statistical analyses to evaluate the quality of the data used are performed, and the suggested correlations are validated with several previous published datasets. The paper also provides some insights into SPT-CPT correlations and soil characteristics(i.e. the mean particle size and the fines fraction of the soil).
基金Fundamental Research Funds for the Central UniversitiesNational Natural Science Foundation of China(NSFC)(11374008,11374238,11374239,11534008)
文摘Vortex beams with fractional topological charge(FTC) have many special characteristics and novel applications.However, one of the obstacles for their application is the difficulty of precisely determining the FTC of fractional vortex beams. We find that when a vortex beam with an FTC illuminates a dynamic angular double slit(ADS), the far-field interference patterns that include the information of the FTC of the beam at the angular bisector direction of the ADS vary periodically. Based on this property, a simple dynamic ADS device and data fitting method can be used to precisely measure the FTC of a vortex light beam with an error of less than 5%.
基金the National Natural Science Foundation of China (Grant No.10674031)
文摘Photodynamics of peripheral antenna complexes,light-harvesting complex (LH2) of Rhodobacter (Rb) Sphaeroides 601,was studied using femtosecond pump-probe technique at different laser wavelengths. The obtained results reveal dramatic dynamical evolutions within B800 and B850 absorption bands of antenna complexes LH2. At excitation wavelength around 835 nm,a sharp photobleaching signal was observed which was assigned to the contribution of the two-exciton state,which was further confirmed by the power dependence measurement. Rate equations with eight-level scheme were used to calculate the population evolution in LH2 and the transient dynamics under femtosecond pulse excitation. The research results prove that not only the transition from ground state to one-exciton state but also that from one-exciton state to two-exciton state contribute to the photodynamics of B850.
基金supported by the Ministry of Science,Research,and the Arts of Baden-Wrttemberg State of Germany and the Chinese Scholarship Council
文摘Ultrafast spectroscopy of semiconductor saturable absorber mirror （SESAM） is measured using a femtosec- ond pump-probe experiment. This allows dynamic responses of SESAM in the cavity to be concluded by ultrafast spectroscopy. Change in reflection is measured as a function of pump-probe delay for different pump excitation fluences. Change of nonlinear reflection of SESAM is measured as a function of incident light energy density. When the excitation fluence increases, nonlinear change in ultrafast spectroscopy of SESAM becomes increasingly significant. When SESAM is pumped by an ultrahigh excitation fluence, the energy density of which is approximately 1400 μJ/cm2, two-photon absorption can be observed visibly in its ultrafast spectroscopy.
