As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde...As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde)at Mt.Qomolangma Base Camp(MQBC;86.85°E,28.14°N;5200 m),a location at an extremely high altitude.A total of ten sounding profiles were obtained between April 30 and May 06,2022,of which seven profiles were above35 km in altitude,with a maximum detection altitude up to 39.0 km.This study presents the temporal variation and vertical distributions of atmospheric temperature,humidity,and ozone during the MQBC campaign.The averaged ozone concentration was high(68.3 ppbv)at the surface and then increased smoothly until peaking(~110 ppbv)in the middle troposphere(approximately 10 km),and afterward,the ozone concentration increased rapidly from the upper troposphere to a maximum of~10 ppmv at~30 km.The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure,and transport from the southern flank of the Himalayas occurred during the campaign period.The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35km in altitude.The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder(MLS)onboard the Aura satellite and the Atmospheric Infrared Sounder(AIRS)onboard the Aqua satellite.展开更多
Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Gl...Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Global Positioning System(GPS)soundings in the eastern tropical Indian Ocean and South China Sea through a simultaneous balloon-borne inter-comparison of different radiosonde types.Our results indicate that the temperature and relative humidity(RH)measurements of GPS-TanKong(GPS-TK)radiosonde(used at most stations before 2012)have larger biases than those of ChangFeng-06-A(CF-06-A)radiosonde(widely used in current observation)when compared to reference data from Vaisala RS92-SGP radiosonde,with a warm bias of 5℃and dry bias of 10%during daytimes,and a cooling bias of-0.8℃and a moist bias of 6%during nighttime.These systematic biases are primarily attributed to the radiation effects and altitude deviation.An empirical correction algorithm was developed to retrieve the atmospheric temperature and RH profiles.The corrected profiles agree well with that of RS92-SGP,except for uncertainties of CF-06-A in the stratosphere.These correction algorithms were applied to the GPS-TK historical sounding records,reducing biases in the corrected temperature and RH profiles when compared to radio occultation data.The correction of GPS-TK historical records illustrated an improvement in capturing the marine atmospheric structure,with more accurate atmospheric boundary layer height,convective available potential energy,and convective inhibition in the tropical ocean.This study contributes significantly to improving the quality of GPS radiosonde soundings and promotes the sharing of observation in the eastern tropical Indian Ocean and South China Sea.展开更多
Introduction: Located in the central-western part of Côte d’Ivoire, the subsoil of the Gagnoa region is made up of sedimentary volcano formations and granitoids with developed fracturing. This complex Precambria...Introduction: Located in the central-western part of Côte d’Ivoire, the subsoil of the Gagnoa region is made up of sedimentary volcano formations and granitoids with developed fracturing. This complex Precambrian basement contains most of the region’s water resources. This is at the origin of the high failure rate during the various hydrogeological prospecting campaigns. Methodology: The database consists of resistivities from 42 holes and 51 trails drilled as part of the implementation of high-throughput drilling in the study area. The objective of this study is to deepen the knowledge of the fissured basement by interpreting profile curves and electrical soundings. It will be a question of classifying the different types of anomalies obtained on the profiles and their shapes. The orientation of the lineaments observed on the profiles was determined. Results: The interpretation of the geophysical data revealed various anomalies, the main ones being of the CC (Conductor Compartment) and CEDP (Contact between two bearings) types. These types of anomalies are mainly expressed in various forms: the “V”, “W” and “U” shapes. From these anomalies and the appearance of the electrical profiles, lineaments and their orientations were identified with N90-100, N130-140, N170-180 as major orientations. Conclusion: These results could contribute to a better understanding of the fractured environment of the Gagnoa region.展开更多
In this paper, the admittance function between seafloor undulations and vertical gravity gradient anomalies was derived. Based on this admittance function, the bathymetry model of 1 minute resolution was predicted fro...In this paper, the admittance function between seafloor undulations and vertical gravity gradient anomalies was derived. Based on this admittance function, the bathymetry model of 1 minute resolution was predicted from vertical gravity gradient anomalies and ship soundings in the experimental area from the northwest Pacific. The accuracy of the model is evaluated using ship soundings and existing models, including ETOPO1, GEBCO, DTU10 and V15.1 from SIO. The model＇s STD is 69. 481m, comparable with V15.1 which is generally believed to have the highest accuracy.展开更多
The Tartar aquifer unit, is located at the SSO of the city of Boujdour, at a distance of nearly 86 km, and crossed (in its western part) by the National Road N1 connecting the towns of Boujdour and Lagouira passing th...The Tartar aquifer unit, is located at the SSO of the city of Boujdour, at a distance of nearly 86 km, and crossed (in its western part) by the National Road N1 connecting the towns of Boujdour and Lagouira passing through the vicinity of the city of Dakhla (PK40). It is exploited by rural settlements for domestic use (especially the inhabitants of fishing villages) and livestock watering, only through wells named Khtout Hobia (IRE 126/124) and Hassi Tartar known as Khtout Trayh (IRE 104/124). These wells have been tracked by a piezometric groundwater table and from 2011 to the present day. The interpretation of the electrical soundings in AB ≤ 2000 m allowed to differentiate the presence of two families of electrical soundings A and B, to establish the resistivity maps in AB = 200, 300 and 400 ihm⋅m with qualitative aspects, to draw up the map of the isohypses of the roof of the intermediate Dt1 representing the impermeable floor of the aquifer and to highlight two types of discontinuities;electrical discontinuities corresponding to lateral facies changes (limit of erosion surfaces) separating the families A and B of electrical soundings and those corresponding to syn-sedimentary faults which structured the formations into horsts and grabens. The lithological sections of the existing water points and that of oil well 43-1 allowed the geological identification of the geoelectric layers highlighted by the electrical soundings diagrams. As a result, the sandstone and lumachelic formations constituting the aquifer are of Moghrebian-Pleistocene age represented by the resistant R (Family A), sometimes grouping, in its basal part, sandstone levels of the Miocene roof (Family B). These formations lie directly on the Miocene sandy marls represented by the intermediate Dt1. For the present work, we will focus only on the transverse geoelectric cross-section TA, with an SW-NE orientation, which characterizes all the longitudinal sections established following the correlation between the different electric sounding diagrams. It highlights the presence of the gravels G1 and G3 separated by the horst H1 where the resistant R is admitted as aquiferous at the level of the gravels G1 (Khtout Trayh well 104/124) and G3 (well 126/124) and sterile at the level of the horst H1.展开更多
Vertical Electrical Soundings (VES) provide fast and economical measurements used in geophysical exploration. VES were carried out in El Sauz-Encinillas (ESE) aquifer, in northern Mexico, to determine apparent resisti...Vertical Electrical Soundings (VES) provide fast and economical measurements used in geophysical exploration. VES were carried out in El Sauz-Encinillas (ESE) aquifer, in northern Mexico, to determine apparent resistivity and geoelectrical units’ thickness. Despite it being one of the three main aquifers feeding Chihuahua city, a lack of available geophysical data prevails in its northern portion. The main goal of this study was the determination of the geoelectrical units in the subsurface stratigraphy via electrical-resistivity soundings. The ESE’ aquifer is located within alluvial Quaternary sediments, with varying granulometry and reaching from a few meters to more than 600 meters of thickness at the center of the valley. Forty-five vertical electrical resistivity soundings (Schlumberger array, maximum AB/2 distance of 500 m) were performed throughout ESE aquifer’s northern portion. Field data were analyzed using software. Results illustrate a wide variability in resistivity values throughout the study area. Five geoelectrical units were identified: 1) a hardpan topsoil, with resistivity values ranging from 200 - 800 Ω-m;2) an alluvial material mixture (sand/silt) with resistivity values ranging from 25 to 100 Ω-m;3) playa lake-type material (clay/evaporites mixture) with resistivity values ranging from 0.2 to 15 Ω-m;4) a gravel/sand mixture with resistivity values from 100 to 300 Ω-m;and 5) a partly fractured rock or conglomeratic material with resistivity values ranging from 400 to 3500 Ω-m. The electrical resistivity data, therefore gives reasonably accurate results that can be used to understand the subsurface stratigraphy and basement configuration in groundwater exploration.展开更多
Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating ag...Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating against the'true'ABL height from aircraft sounding profiles, where ABL height is defined as the top of the layer with significant turbulence. Furthermore, the best performing method was used to estimate ABL height from the one-year GPS soundings obtained during SHEBA (October 1997-October 1998). It was found that the temperature gradient method produces a reliable estimate of ABL height. Additionally, the authors determined optimal threshold values of temperature gradient for stable boundary layer (SBL) and convective boundary layer (CBL) to be 6.5 K/100 m and 1.0 K/100 m, respectively. The maximum ABL height during the year was 1150 m occurred in May. Median values of Arctic ABL height in May, June, July, and August were 400 m, 430 m, 180 m, and 320 m, respectively. Arctic ABL heights are clearly higher in the spring than in the summer.展开更多
This study uses a recently proposed algorithm for consideration of soil sounding locations in the bearing capacity estimations of spatially variable soil for rectangular footings.The objective of the study is to asses...This study uses a recently proposed algorithm for consideration of soil sounding locations in the bearing capacity estimations of spatially variable soil for rectangular footings.The objective of the study is to assess the possibility of indicating general guidelines for optimal soil sounding locations in the case of two soundings and rectangular footings.The possibility of proposing such general guidelines would be extremely valuable from the engineering practice point of view.Moreover,it would be promising for future studies concerning more complex foundation arrangements.For this reason,numerous scenarios are analyzed for a variety of vertical and horizontal fluctuation scales and a variety of rectangular foundation lengths.For generality of the results,two correlation structures are considered,i.e.the Gaussian and the Markovian ones.The optimal sounding location results are discussed.The observations indicate that,for a specified vertical fluctuation scale,all optimal borehole locations in dimensionless coordinates form a curve.This phenomenon can be utilized in practical applications.The potential applications of the obtained results and the directions for future studies in this area are also discussed.展开更多
The nautical chart is one of the fundamental tools in navigation used by mariners to plan and safely execute voyages.Its compilation follows strict cartographic constraints with the most prominent being that of the sa...The nautical chart is one of the fundamental tools in navigation used by mariners to plan and safely execute voyages.Its compilation follows strict cartographic constraints with the most prominent being that of the safety.Thereby,the cartographer is called to make the selection of the bathymetric information for portrayal on charts in a way that,at any location,the expected water depth is not deeper than the source information.To validate the shoal-biased pattern of selection two standard tests are used,i.e.the triangle and edge tests.To date,some efforts have been made towards the automation of the triangle test,but the edge test has been largely ignored.In the context of research on a fully automated solution for the compilation of charts at different scales from the source information,this paper presents an algorithmic implementation of the two tests for the validation of selected soundings.Through a case study with real-world data,it presents the improved performance of the implementation near and within depth curves and coastlines and points out the importance of the edge test in the validation process.It also presents the,by definition,intrinsic limitation of the two tests as part of a fully automated solution and discusses the need for a new test that will complement or supersede the existing ones.展开更多
The mid-wave infrared band （3-5 #rn） has been widely used for atmospheric soundings. The sunglint impact on the atmospheric parameter retrieval using this band has been neglected because the reflected radiances in t...The mid-wave infrared band （3-5 #rn） has been widely used for atmospheric soundings. The sunglint impact on the atmospheric parameter retrieval using this band has been neglected because the reflected radiances in this band are significantly less than those in the visible band. In this study, an investigation of sunglint impact on the atmospheric soundings was conducted with Atmospheric InfraRed Sounder ob- servation data from 1 July to 7 July 2007 over the Atlantic Ocean. The impact of sunglint can lead to a brightness temperature increase of 1.0 K for the surface sensitive sounding channels near 4.58 #m. This contamination can indirectly cause a positive bias of 4 g kg-1 in the water vapor retrieval near the ocean surface, and it can be corrected by simply excluding those contaminated channels.展开更多
This study was aimed at mapping the subsurface extent of saline water intrusions into aquifers at the eastern part of Dahomey basin, Nigeria. The study adopted geoelectric sounding methods. 108 vertical electrical sou...This study was aimed at mapping the subsurface extent of saline water intrusions into aquifers at the eastern part of Dahomey basin, Nigeria. The study adopted geoelectric sounding methods. 108 vertical electrical soundings (VES) and 9 induced polarization soundings (IPS) data were acquired using Schlumberger array technique. Three aquifer units were delineated across the study area. The resistivity of the first, second and third aquifer layers varies from 0.2 to 1569 ohm-m, 0.5 to 904 ohm-m and 0.4 to 665 ohm-m respectively, while depth to the top of first, second and third aquifer varies respectively from 0.7 to 151.5 m, 1.4 to 305.5 m and 12.9 to 452.9 m. The depth to the first aquifer layer is shallow (less than 5 m) in the coastal area which makes this area to be highly vulnerable to anthropogenic pollution while their proximity to Atlantic Ocean makes them susceptible to saline water intrusion. In all the three aquifer units, the coastal area, Agbabu and other few locations in the mainland are characterized by low resistivity values (below 60 ohm-m) indicating possible presence of brackish or saline water. IP sounding results showed that all the low resistive layers in the mainland are characterized by clayey materials. The integration of VES and IPS results enabled the delineation of the saline water lateral extent across the study area. There is a strong direct correlation (r2 = 0.8564) between location distance from the saline water source and depth to saline water in the study area. This can therefore serve as a predictive model to determine depth to saline water at any location within the saline water zone in the study area.展开更多
From China to Russia,Tan-Lu fault system stretches for thousands of kilometers,towards NE 30°.The authors have collected more than ten magnetotelluric profile that China and Russia have carried out,in the studied...From China to Russia,Tan-Lu fault system stretches for thousands of kilometers,towards NE 30°.The authors have collected more than ten magnetotelluric profile that China and Russia have carried out,in the studied area of the Tan-Lu fault's northern section,and have analyzed electrical characteristics of the relevant profiles.Deriving the following conclusions:(1)Jiamusi-Bureya plots,etc.,demonstrate the high resistance of Kernel;(2)Fold belt attributed to the land showed high and low resistance stitching,associated with not only terrane accretion,but also upper mantle upwelling;below the sedimentary basin,the resistivity of the upper mantle is lower and closer to the surface comparing with the adjacent area(100-150);(3)In the system of Tan-Lu fracture,Yishu and Dunmi fracture,etc.are expressed as vertical low-resistivity zone;(4)There may exist subducted old-fashioned piece under Jiamusi and Bureya plots.展开更多
This research aims to address the pressing issue of failed and abandoned wells, causing water scarcity in Lapan Gwari Community, through an improved groundwater exploration approach integrating remote sensing and elec...This research aims to address the pressing issue of failed and abandoned wells, causing water scarcity in Lapan Gwari Community, through an improved groundwater exploration approach integrating remote sensing and electrical resistivity soundings. The study area, located within the Zungeru Sheet 163 SE, spans Latitudes 9°30'00"N to 9°32'00"N and Longitudes 6°28'00" to 6°30'00". The surface geologic, structural, and hydrogeological mapping provided essential insights into the hydrogeological framework. Leveraging SRTM DEM data, thematic maps were created for geomorphology, slope, land use, lineament density, and drainage density. These datasets were then integrated using ArcGIS to develop a preliminary groundwater potential zones map. Further investigations were conducted using Vertical Electrical Sounding (VES) and Electrical Resistivity Imaging (2D VES) surveys at targeted locations identified by the preliminary map. Results show that the study area predominantly consists of crystalline rocks of the Nigerian Basement Complex, primarily comprising schist and granite with minor occurrences of quartz vein intrusions. Surface joint directions indicated a dominant NE-SW trend. The VES data revealed three to four geoelectric layers, encompassing the topsoil (1 to 5 m depth, resistivity: 100 Ωm to 300 Ωm), the weathered layer (in the 3-layer system) or fractured layer (in the 4-layer system), and the fresh basement rock characterized by infinite resistivity. The shallow weathered layers (3 to 30 m thickness) are believed to hold aquiferous potential. Hydrogeological interpretation, facilitated by 2D resistivity models, delineated water horizons trapped within clayey sand and weathered/fractured formations. Notably, the aquifer resistivity range was found to be between 3 - 35 m and 100 - 300 Ωm, signifying a promising aquifer positioned at depths of 40 to 88 m. This aligns with corroborative static water level measurements. Given this, we recommend drilling depths of a minimum of 80 m to ensure the acquisition of sufficient and sustainable water supplies. The final groundwater potential zones map derived from this study is expected to serve as an invaluable guide for prospective groundwater developers and relevant authorities in formulating effective water resource management plans. By effectively tackling water scarcity challenges in Lapan Gwari Community, this integrated approach demonstrates its potential for application in similar regions facing comparable hydrogeological concerns.展开更多
The active sound absorption technique excels in mitigating low-frequency sound waves,yet it falls short when dealing with medium and high-frequency sound waves.To enhance the sound-absorbing effect of medium and high-...The active sound absorption technique excels in mitigating low-frequency sound waves,yet it falls short when dealing with medium and high-frequency sound waves.To enhance the sound-absorbing effect of medium and high-frequency sound waves,a novel semi-active sound absorption method has been introduced.This method modulates the surface impedance of a loudspeaker positioned behind the sound-absorbing material,thereby altering the sound absorption coefficient.The theoretical sound absorption coefficient is calculated using MATLAB and compared with the experimental one.Results show that the method can effectively modulates the absorption coefficient in response to varying incident sound wave frequencies,ensuring that it remains at its peak value.展开更多
Metal foams are a fascinating group of materials that possess distinct physicochEMIcal properties and interconnected strut features with high surface area-to-volume ratios, high specific strength and lightweight natur...Metal foams are a fascinating group of materials that possess distinct physicochEMIcal properties and interconnected strut features with high surface area-to-volume ratios, high specific strength and lightweight nature. These characteristics make them ideal for applications in vibration damping, heat insulation and weight reduction. In recent years, there has been increasing interest in the application of interfering energy conversion such as electromagnetic wave (EMW) and sound, where the metal foams could emerge as a solution. This paper will present a comprehensive review of the preparation methods as well as the interference energy converting mechanisms for metal foams. Typically, the progress and prospective aspects of metal foams for EMW absorption, electromagnetic interference (EMI) shielding and sound absorption have been emphasized. Through this review, we aspire to offer valuable insights for the development of multifunctional applications with metal foam materials.展开更多
To the editor:The superior semicircular canal dehiscence was first described by Minor et all in 1998 as a condition in which the superior semicircular canal lacks a bony covering and has gained constantly increasing i...To the editor:The superior semicircular canal dehiscence was first described by Minor et all in 1998 as a condition in which the superior semicircular canal lacks a bony covering and has gained constantly increasing interest since its discovery.2 The symptoms are varied but specific what is known as Minor syndrome or‘third mobile window’syndrome,'as patients may experience autophony with abnormally loud sounds like footsteps,chewing,breathing,eye movement,echoing voice,distortion of environmental sounds and pulsatile tinnitus.展开更多
一、单词拼写1.Light travels much faster than___(声音).2.It's______(容易的)for us to pay online with Alipay now,3.The teacher often____(测试)his students in math.4.At that time,things could be_____(困难的)for the w...一、单词拼写1.Light travels much faster than___(声音).2.It's______(容易的)for us to pay online with Alipay now,3.The teacher often____(测试)his students in math.4.At that time,things could be_____(困难的)for the workers.5.It's said that she's__(储备)nearly one ton of potatoes at home.6.In his spare time,Dr.Yuan loves playing the piano and listening to__(音乐),especially Mozart's.展开更多
The emerging millimeter-wave microphones have garnered considerable attention in recent years due to their potential for sound detection in various applications,particularly in situations where traditional microphones...The emerging millimeter-wave microphones have garnered considerable attention in recent years due to their potential for sound detection in various applications,particularly in situations where traditional microphones may be impractical.However,despite their promise,there is a notable lack of evidence demonstrating high-quality sound recovery of moving sources,which remains a significant challenge in thefield.This paper addresses this critical gap by proposing a novel method for displacement alignment that improves the detection and recovery of sound signals from moving sources.The proposed method works byfirst aligning the displacement of the sound source over time,which ensures that the signals are synchronized and avoids interference from movement of sources.Subsequently,precise surface vibrations are extracted from the aligned signals,providing data for sound recovery.Afinite impulse response(FIR)filter is applied to remove low-frequency motion,which often interferes with the clarity of the detected sound.Experimental results demonstrate the method’s effectiveness in recovering high-quality sound from moving sources,offering a promising solution for advancing the emerging millimeter-wave microphone technology in real-world applications.This work could pave the way for more accurate and reliable sound detection systems,particularly in dynamic environments.展开更多
The classification of respiratory sounds is crucial in diagnosing and monitoring respiratory diseases.However,auscultation is highly subjective,making it challenging to analyze respiratory sounds accurately.Although d...The classification of respiratory sounds is crucial in diagnosing and monitoring respiratory diseases.However,auscultation is highly subjective,making it challenging to analyze respiratory sounds accurately.Although deep learning has been increasingly applied to this task,most existing approaches have primarily relied on supervised learning.Since supervised learning requires large amounts of labeled data,recent studies have explored self-supervised and semi-supervised methods to overcome this limitation.However,these approaches have largely assumed a closedset setting,where the classes present in the unlabeled data are considered identical to those in the labeled data.In contrast,this study explores an open-set semi-supervised learning setting,where the unlabeled data may contain additional,unknown classes.To address this challenge,a distance-based prototype network is employed to classify respiratory sounds in an open-set setting.In the first stage,the prototype network is trained using labeled and unlabeled data to derive prototype representations of known classes.In the second stage,distances between unlabeled data and known class prototypes are computed,and samples exceeding an adaptive threshold are identified as unknown.A new prototype is then calculated for this unknown class.In the final stage,semi-supervised learning is employed to classify labeled and unlabeled data into known and unknown classes.Compared to conventional closed-set semisupervised learning approaches,the proposed method achieved an average classification accuracy improvement of 2%–5%.Additionally,in cases of data scarcity,utilizing unlabeled data further improved classification performance by 6%–8%.The findings of this study are expected to significantly enhance respiratory sound classification performance in practical clinical settings.展开更多
This article presents the optical evaluation of the vibrational behavior of a steel bar,by a non-conventional optoacoustic procedure,the LPD(laser photo deflection)method.On this occasion the bar is located horizontal...This article presents the optical evaluation of the vibrational behavior of a steel bar,by a non-conventional optoacoustic procedure,the LPD(laser photo deflection)method.On this occasion the bar is located horizontal and fixed at both ends.Through our procedure we experimentally find the first 9 Eigen frequencies(21 Hz,60 Hz,116 Hz...)and correlate them using the cantilever theory.展开更多
基金supported by the second Tibetan Plateau Scientific Expedition and Research Program(STEP,2019QZKK0606,2019QZKK0604)the National Natural Science Foundation of China(Grant No.41875183)。
文摘As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde)at Mt.Qomolangma Base Camp(MQBC;86.85°E,28.14°N;5200 m),a location at an extremely high altitude.A total of ten sounding profiles were obtained between April 30 and May 06,2022,of which seven profiles were above35 km in altitude,with a maximum detection altitude up to 39.0 km.This study presents the temporal variation and vertical distributions of atmospheric temperature,humidity,and ozone during the MQBC campaign.The averaged ozone concentration was high(68.3 ppbv)at the surface and then increased smoothly until peaking(~110 ppbv)in the middle troposphere(approximately 10 km),and afterward,the ozone concentration increased rapidly from the upper troposphere to a maximum of~10 ppmv at~30 km.The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure,and transport from the southern flank of the Himalayas occurred during the campaign period.The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35km in altitude.The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder(MLS)onboard the Aura satellite and the Atmospheric Infrared Sounder(AIRS)onboard the Aqua satellite.
基金The Second Tibetan Plateau Scientific Expedition and Research Program under contract No.2019QZKK0102-02the National Natural Science Foundation of China under contract Nos 42230402,92158204,42176026,42076201,41049903,41149908,41249906,41249907,and 41249910+2 种基金the Guangdong Basic and Applied Basic Research Foundation under contract No.2022A1515240069the Marine Economic Development Special Program of Guangdong Province(Six Major Marine Industries):Research and Demonstration of Critical Technologies for Comprehensive Prevention and Control of Natural Disaster in Offshore Wind Farms,China under contract No.29[2023]the Fund of Fujian Provincial Key Laboratory of Marine Physical and Geological Processes under contract No.KLMPG-22-02.
文摘Shipboard radiosonde soundings are important for detecting and quantifying the multiscale variability of atmosphere-ocean interactions associated with mass exchanges.This study evaluated the accuracies of shipboard Global Positioning System(GPS)soundings in the eastern tropical Indian Ocean and South China Sea through a simultaneous balloon-borne inter-comparison of different radiosonde types.Our results indicate that the temperature and relative humidity(RH)measurements of GPS-TanKong(GPS-TK)radiosonde(used at most stations before 2012)have larger biases than those of ChangFeng-06-A(CF-06-A)radiosonde(widely used in current observation)when compared to reference data from Vaisala RS92-SGP radiosonde,with a warm bias of 5℃and dry bias of 10%during daytimes,and a cooling bias of-0.8℃and a moist bias of 6%during nighttime.These systematic biases are primarily attributed to the radiation effects and altitude deviation.An empirical correction algorithm was developed to retrieve the atmospheric temperature and RH profiles.The corrected profiles agree well with that of RS92-SGP,except for uncertainties of CF-06-A in the stratosphere.These correction algorithms were applied to the GPS-TK historical sounding records,reducing biases in the corrected temperature and RH profiles when compared to radio occultation data.The correction of GPS-TK historical records illustrated an improvement in capturing the marine atmospheric structure,with more accurate atmospheric boundary layer height,convective available potential energy,and convective inhibition in the tropical ocean.This study contributes significantly to improving the quality of GPS radiosonde soundings and promotes the sharing of observation in the eastern tropical Indian Ocean and South China Sea.
文摘Introduction: Located in the central-western part of Côte d’Ivoire, the subsoil of the Gagnoa region is made up of sedimentary volcano formations and granitoids with developed fracturing. This complex Precambrian basement contains most of the region’s water resources. This is at the origin of the high failure rate during the various hydrogeological prospecting campaigns. Methodology: The database consists of resistivities from 42 holes and 51 trails drilled as part of the implementation of high-throughput drilling in the study area. The objective of this study is to deepen the knowledge of the fissured basement by interpreting profile curves and electrical soundings. It will be a question of classifying the different types of anomalies obtained on the profiles and their shapes. The orientation of the lineaments observed on the profiles was determined. Results: The interpretation of the geophysical data revealed various anomalies, the main ones being of the CC (Conductor Compartment) and CEDP (Contact between two bearings) types. These types of anomalies are mainly expressed in various forms: the “V”, “W” and “U” shapes. From these anomalies and the appearance of the electrical profiles, lineaments and their orientations were identified with N90-100, N130-140, N170-180 as major orientations. Conclusion: These results could contribute to a better understanding of the fractured environment of the Gagnoa region.
基金supported by the Director Foundation of Institute of Seismology,China Earthquake Administration(IS201326125)the National Natural Science Foundation of China(41204019,41304003)
文摘In this paper, the admittance function between seafloor undulations and vertical gravity gradient anomalies was derived. Based on this admittance function, the bathymetry model of 1 minute resolution was predicted from vertical gravity gradient anomalies and ship soundings in the experimental area from the northwest Pacific. The accuracy of the model is evaluated using ship soundings and existing models, including ETOPO1, GEBCO, DTU10 and V15.1 from SIO. The model＇s STD is 69. 481m, comparable with V15.1 which is generally believed to have the highest accuracy.
文摘The Tartar aquifer unit, is located at the SSO of the city of Boujdour, at a distance of nearly 86 km, and crossed (in its western part) by the National Road N1 connecting the towns of Boujdour and Lagouira passing through the vicinity of the city of Dakhla (PK40). It is exploited by rural settlements for domestic use (especially the inhabitants of fishing villages) and livestock watering, only through wells named Khtout Hobia (IRE 126/124) and Hassi Tartar known as Khtout Trayh (IRE 104/124). These wells have been tracked by a piezometric groundwater table and from 2011 to the present day. The interpretation of the electrical soundings in AB ≤ 2000 m allowed to differentiate the presence of two families of electrical soundings A and B, to establish the resistivity maps in AB = 200, 300 and 400 ihm⋅m with qualitative aspects, to draw up the map of the isohypses of the roof of the intermediate Dt1 representing the impermeable floor of the aquifer and to highlight two types of discontinuities;electrical discontinuities corresponding to lateral facies changes (limit of erosion surfaces) separating the families A and B of electrical soundings and those corresponding to syn-sedimentary faults which structured the formations into horsts and grabens. The lithological sections of the existing water points and that of oil well 43-1 allowed the geological identification of the geoelectric layers highlighted by the electrical soundings diagrams. As a result, the sandstone and lumachelic formations constituting the aquifer are of Moghrebian-Pleistocene age represented by the resistant R (Family A), sometimes grouping, in its basal part, sandstone levels of the Miocene roof (Family B). These formations lie directly on the Miocene sandy marls represented by the intermediate Dt1. For the present work, we will focus only on the transverse geoelectric cross-section TA, with an SW-NE orientation, which characterizes all the longitudinal sections established following the correlation between the different electric sounding diagrams. It highlights the presence of the gravels G1 and G3 separated by the horst H1 where the resistant R is admitted as aquiferous at the level of the gravels G1 (Khtout Trayh well 104/124) and G3 (well 126/124) and sterile at the level of the horst H1.
文摘Vertical Electrical Soundings (VES) provide fast and economical measurements used in geophysical exploration. VES were carried out in El Sauz-Encinillas (ESE) aquifer, in northern Mexico, to determine apparent resistivity and geoelectrical units’ thickness. Despite it being one of the three main aquifers feeding Chihuahua city, a lack of available geophysical data prevails in its northern portion. The main goal of this study was the determination of the geoelectrical units in the subsurface stratigraphy via electrical-resistivity soundings. The ESE’ aquifer is located within alluvial Quaternary sediments, with varying granulometry and reaching from a few meters to more than 600 meters of thickness at the center of the valley. Forty-five vertical electrical resistivity soundings (Schlumberger array, maximum AB/2 distance of 500 m) were performed throughout ESE aquifer’s northern portion. Field data were analyzed using software. Results illustrate a wide variability in resistivity values throughout the study area. Five geoelectrical units were identified: 1) a hardpan topsoil, with resistivity values ranging from 200 - 800 Ω-m;2) an alluvial material mixture (sand/silt) with resistivity values ranging from 25 to 100 Ω-m;3) playa lake-type material (clay/evaporites mixture) with resistivity values ranging from 0.2 to 15 Ω-m;4) a gravel/sand mixture with resistivity values from 100 to 300 Ω-m;and 5) a partly fractured rock or conglomeratic material with resistivity values ranging from 400 to 3500 Ω-m. The electrical resistivity data, therefore gives reasonably accurate results that can be used to understand the subsurface stratigraphy and basement configuration in groundwater exploration.
基金supported by the China Meteorological Administration under Grant GYHY201006024the Chinese Academy of Sciences Strategic Priority Research Program under Grant XDA05110104spon-sorship of National Science Foundation
文摘Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating against the'true'ABL height from aircraft sounding profiles, where ABL height is defined as the top of the layer with significant turbulence. Furthermore, the best performing method was used to estimate ABL height from the one-year GPS soundings obtained during SHEBA (October 1997-October 1998). It was found that the temperature gradient method produces a reliable estimate of ABL height. Additionally, the authors determined optimal threshold values of temperature gradient for stable boundary layer (SBL) and convective boundary layer (CBL) to be 6.5 K/100 m and 1.0 K/100 m, respectively. The maximum ABL height during the year was 1150 m occurred in May. Median values of Arctic ABL height in May, June, July, and August were 400 m, 430 m, 180 m, and 320 m, respectively. Arctic ABL heights are clearly higher in the spring than in the summer.
文摘This study uses a recently proposed algorithm for consideration of soil sounding locations in the bearing capacity estimations of spatially variable soil for rectangular footings.The objective of the study is to assess the possibility of indicating general guidelines for optimal soil sounding locations in the case of two soundings and rectangular footings.The possibility of proposing such general guidelines would be extremely valuable from the engineering practice point of view.Moreover,it would be promising for future studies concerning more complex foundation arrangements.For this reason,numerous scenarios are analyzed for a variety of vertical and horizontal fluctuation scales and a variety of rectangular foundation lengths.For generality of the results,two correlation structures are considered,i.e.the Gaussian and the Markovian ones.The optimal sounding location results are discussed.The observations indicate that,for a specified vertical fluctuation scale,all optimal borehole locations in dimensionless coordinates form a curve.This phenomenon can be utilized in practical applications.The potential applications of the obtained results and the directions for future studies in this area are also discussed.
基金This work is supported by the National Oceanic and Atmospheric Administration[grant number NA15NOS4000200].
文摘The nautical chart is one of the fundamental tools in navigation used by mariners to plan and safely execute voyages.Its compilation follows strict cartographic constraints with the most prominent being that of the safety.Thereby,the cartographer is called to make the selection of the bathymetric information for portrayal on charts in a way that,at any location,the expected water depth is not deeper than the source information.To validate the shoal-biased pattern of selection two standard tests are used,i.e.the triangle and edge tests.To date,some efforts have been made towards the automation of the triangle test,but the edge test has been largely ignored.In the context of research on a fully automated solution for the compilation of charts at different scales from the source information,this paper presents an algorithmic implementation of the two tests for the validation of selected soundings.Through a case study with real-world data,it presents the improved performance of the implementation near and within depth curves and coastlines and points out the importance of the edge test in the validation process.It also presents the,by definition,intrinsic limitation of the two tests as part of a fully automated solution and discusses the need for a new test that will complement or supersede the existing ones.
基金partly supported by the National Oceanic and Atmospheric Administration (NOAA) GOES-R algorithm working group(AWG) and GOES-R Risk Reduction programs (Grant No.NA06NES4400002)
文摘The mid-wave infrared band （3-5 #rn） has been widely used for atmospheric soundings. The sunglint impact on the atmospheric parameter retrieval using this band has been neglected because the reflected radiances in this band are significantly less than those in the visible band. In this study, an investigation of sunglint impact on the atmospheric soundings was conducted with Atmospheric InfraRed Sounder ob- servation data from 1 July to 7 July 2007 over the Atlantic Ocean. The impact of sunglint can lead to a brightness temperature increase of 1.0 K for the surface sensitive sounding channels near 4.58 #m. This contamination can indirectly cause a positive bias of 4 g kg-1 in the water vapor retrieval near the ocean surface, and it can be corrected by simply excluding those contaminated channels.
文摘This study was aimed at mapping the subsurface extent of saline water intrusions into aquifers at the eastern part of Dahomey basin, Nigeria. The study adopted geoelectric sounding methods. 108 vertical electrical soundings (VES) and 9 induced polarization soundings (IPS) data were acquired using Schlumberger array technique. Three aquifer units were delineated across the study area. The resistivity of the first, second and third aquifer layers varies from 0.2 to 1569 ohm-m, 0.5 to 904 ohm-m and 0.4 to 665 ohm-m respectively, while depth to the top of first, second and third aquifer varies respectively from 0.7 to 151.5 m, 1.4 to 305.5 m and 12.9 to 452.9 m. The depth to the first aquifer layer is shallow (less than 5 m) in the coastal area which makes this area to be highly vulnerable to anthropogenic pollution while their proximity to Atlantic Ocean makes them susceptible to saline water intrusion. In all the three aquifer units, the coastal area, Agbabu and other few locations in the mainland are characterized by low resistivity values (below 60 ohm-m) indicating possible presence of brackish or saline water. IP sounding results showed that all the low resistive layers in the mainland are characterized by clayey materials. The integration of VES and IPS results enabled the delineation of the saline water lateral extent across the study area. There is a strong direct correlation (r2 = 0.8564) between location distance from the saline water source and depth to saline water in the study area. This can therefore serve as a predictive model to determine depth to saline water at any location within the saline water zone in the study area.
基金the Project 12-05-91158 of the National Natural Science Foundation of China(NSFC)the Russian Academy of Sciences"Deep structure,evolution of the sedimentogenesis and tectonics of Northeastern China and southeastern Far East Russia"
文摘From China to Russia,Tan-Lu fault system stretches for thousands of kilometers,towards NE 30°.The authors have collected more than ten magnetotelluric profile that China and Russia have carried out,in the studied area of the Tan-Lu fault's northern section,and have analyzed electrical characteristics of the relevant profiles.Deriving the following conclusions:(1)Jiamusi-Bureya plots,etc.,demonstrate the high resistance of Kernel;(2)Fold belt attributed to the land showed high and low resistance stitching,associated with not only terrane accretion,but also upper mantle upwelling;below the sedimentary basin,the resistivity of the upper mantle is lower and closer to the surface comparing with the adjacent area(100-150);(3)In the system of Tan-Lu fracture,Yishu and Dunmi fracture,etc.are expressed as vertical low-resistivity zone;(4)There may exist subducted old-fashioned piece under Jiamusi and Bureya plots.
文摘This research aims to address the pressing issue of failed and abandoned wells, causing water scarcity in Lapan Gwari Community, through an improved groundwater exploration approach integrating remote sensing and electrical resistivity soundings. The study area, located within the Zungeru Sheet 163 SE, spans Latitudes 9°30'00"N to 9°32'00"N and Longitudes 6°28'00" to 6°30'00". The surface geologic, structural, and hydrogeological mapping provided essential insights into the hydrogeological framework. Leveraging SRTM DEM data, thematic maps were created for geomorphology, slope, land use, lineament density, and drainage density. These datasets were then integrated using ArcGIS to develop a preliminary groundwater potential zones map. Further investigations were conducted using Vertical Electrical Sounding (VES) and Electrical Resistivity Imaging (2D VES) surveys at targeted locations identified by the preliminary map. Results show that the study area predominantly consists of crystalline rocks of the Nigerian Basement Complex, primarily comprising schist and granite with minor occurrences of quartz vein intrusions. Surface joint directions indicated a dominant NE-SW trend. The VES data revealed three to four geoelectric layers, encompassing the topsoil (1 to 5 m depth, resistivity: 100 Ωm to 300 Ωm), the weathered layer (in the 3-layer system) or fractured layer (in the 4-layer system), and the fresh basement rock characterized by infinite resistivity. The shallow weathered layers (3 to 30 m thickness) are believed to hold aquiferous potential. Hydrogeological interpretation, facilitated by 2D resistivity models, delineated water horizons trapped within clayey sand and weathered/fractured formations. Notably, the aquifer resistivity range was found to be between 3 - 35 m and 100 - 300 Ωm, signifying a promising aquifer positioned at depths of 40 to 88 m. This aligns with corroborative static water level measurements. Given this, we recommend drilling depths of a minimum of 80 m to ensure the acquisition of sufficient and sustainable water supplies. The final groundwater potential zones map derived from this study is expected to serve as an invaluable guide for prospective groundwater developers and relevant authorities in formulating effective water resource management plans. By effectively tackling water scarcity challenges in Lapan Gwari Community, this integrated approach demonstrates its potential for application in similar regions facing comparable hydrogeological concerns.
基金National Natural Science Foundation of China(No.51705545)。
文摘The active sound absorption technique excels in mitigating low-frequency sound waves,yet it falls short when dealing with medium and high-frequency sound waves.To enhance the sound-absorbing effect of medium and high-frequency sound waves,a novel semi-active sound absorption method has been introduced.This method modulates the surface impedance of a loudspeaker positioned behind the sound-absorbing material,thereby altering the sound absorption coefficient.The theoretical sound absorption coefficient is calculated using MATLAB and compared with the experimental one.Results show that the method can effectively modulates the absorption coefficient in response to varying incident sound wave frequencies,ensuring that it remains at its peak value.
基金supported by the National Natural Science Foundation of China(No.52271180)the Leading Goose R&D Program of Zhejiang Province(2022C01110).
文摘Metal foams are a fascinating group of materials that possess distinct physicochEMIcal properties and interconnected strut features with high surface area-to-volume ratios, high specific strength and lightweight nature. These characteristics make them ideal for applications in vibration damping, heat insulation and weight reduction. In recent years, there has been increasing interest in the application of interfering energy conversion such as electromagnetic wave (EMW) and sound, where the metal foams could emerge as a solution. This paper will present a comprehensive review of the preparation methods as well as the interference energy converting mechanisms for metal foams. Typically, the progress and prospective aspects of metal foams for EMW absorption, electromagnetic interference (EMI) shielding and sound absorption have been emphasized. Through this review, we aspire to offer valuable insights for the development of multifunctional applications with metal foam materials.
文摘To the editor:The superior semicircular canal dehiscence was first described by Minor et all in 1998 as a condition in which the superior semicircular canal lacks a bony covering and has gained constantly increasing interest since its discovery.2 The symptoms are varied but specific what is known as Minor syndrome or‘third mobile window’syndrome,'as patients may experience autophony with abnormally loud sounds like footsteps,chewing,breathing,eye movement,echoing voice,distortion of environmental sounds and pulsatile tinnitus.
文摘一、单词拼写1.Light travels much faster than___(声音).2.It's______(容易的)for us to pay online with Alipay now,3.The teacher often____(测试)his students in math.4.At that time,things could be_____(困难的)for the workers.5.It's said that she's__(储备)nearly one ton of potatoes at home.6.In his spare time,Dr.Yuan loves playing the piano and listening to__(音乐),especially Mozart's.
基金supported by the National Natural Science Foundation of China under Grant No.51905341the Natural Science Foundation of Shanghai under Grant 22ZR1433900.
文摘The emerging millimeter-wave microphones have garnered considerable attention in recent years due to their potential for sound detection in various applications,particularly in situations where traditional microphones may be impractical.However,despite their promise,there is a notable lack of evidence demonstrating high-quality sound recovery of moving sources,which remains a significant challenge in thefield.This paper addresses this critical gap by proposing a novel method for displacement alignment that improves the detection and recovery of sound signals from moving sources.The proposed method works byfirst aligning the displacement of the sound source over time,which ensures that the signals are synchronized and avoids interference from movement of sources.Subsequently,precise surface vibrations are extracted from the aligned signals,providing data for sound recovery.Afinite impulse response(FIR)filter is applied to remove low-frequency motion,which often interferes with the clarity of the detected sound.Experimental results demonstrate the method’s effectiveness in recovering high-quality sound from moving sources,offering a promising solution for advancing the emerging millimeter-wave microphone technology in real-world applications.This work could pave the way for more accurate and reliable sound detection systems,particularly in dynamic environments.
基金supported by Innovative Human Resource Development for Local Intellectualization Programthrough the Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(IITP-2025-RS-2022-00156360).
文摘The classification of respiratory sounds is crucial in diagnosing and monitoring respiratory diseases.However,auscultation is highly subjective,making it challenging to analyze respiratory sounds accurately.Although deep learning has been increasingly applied to this task,most existing approaches have primarily relied on supervised learning.Since supervised learning requires large amounts of labeled data,recent studies have explored self-supervised and semi-supervised methods to overcome this limitation.However,these approaches have largely assumed a closedset setting,where the classes present in the unlabeled data are considered identical to those in the labeled data.In contrast,this study explores an open-set semi-supervised learning setting,where the unlabeled data may contain additional,unknown classes.To address this challenge,a distance-based prototype network is employed to classify respiratory sounds in an open-set setting.In the first stage,the prototype network is trained using labeled and unlabeled data to derive prototype representations of known classes.In the second stage,distances between unlabeled data and known class prototypes are computed,and samples exceeding an adaptive threshold are identified as unknown.A new prototype is then calculated for this unknown class.In the final stage,semi-supervised learning is employed to classify labeled and unlabeled data into known and unknown classes.Compared to conventional closed-set semisupervised learning approaches,the proposed method achieved an average classification accuracy improvement of 2%–5%.Additionally,in cases of data scarcity,utilizing unlabeled data further improved classification performance by 6%–8%.The findings of this study are expected to significantly enhance respiratory sound classification performance in practical clinical settings.
文摘This article presents the optical evaluation of the vibrational behavior of a steel bar,by a non-conventional optoacoustic procedure,the LPD(laser photo deflection)method.On this occasion the bar is located horizontal and fixed at both ends.Through our procedure we experimentally find the first 9 Eigen frequencies(21 Hz,60 Hz,116 Hz...)and correlate them using the cantilever theory.
