In a context of cryosphere degradation caused by climate warming,rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes.In order to improve the knowledge of this ...In a context of cryosphere degradation caused by climate warming,rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes.In order to improve the knowledge of this critical relationship,it is necessary to increase measurement capability of rock temperature and its variability in different lithological and slope/aspect conditions,and also to increase local scale studies,increasing the quality and the comparability of the data.This paper shows an example of metrological characterization of sensors used for rock temperature measurement in mountain regions,by means of the measurement uncertainty.Under such approach,data and results from temperature measurements carried out in the Bessanese high-elevation experimental site(Western European Alps)are illustrated.The procedures for the calibration and field characterization of sensors allow to measure temperature in different locations,depths and lithotypes,within 0.10°C of overall uncertainty.This work has highlighted that metrological traceability is fundamental to asses data quality and establish comparability among different measurements;that there are strong differences between air temperature and near-surface rock temperature;and that there are significant differences of rock temperature acquired in different aspect conditions.Finally,solar radiation,slope/aspect conditions and lithotype,seem to be the main driving factors of rock temperature.展开更多
In-situ calibrations of weather stations are usually performed by positioning standard instruments close to the station under calibration and comparing the obtained results. This procedure could be useful to evaluate ...In-situ calibrations of weather stations are usually performed by positioning standard instruments close to the station under calibration and comparing the obtained results. This procedure could be useful to evaluate the proper functioning of the monitoring equipments, but do not allowed the determination of a calibration curve that allow the corrections of the acquired parameters. Thus, the development of a dedicated facility for in-situ calibration of weather stations, enabling simultaneous generation of a wide range of temperatures and pressures could offer important improvements in this framework, particularly if this facility is applied to high mountains monitoring stations where the weather stations calibrations could be very difficult. This paper will present the calibration chamber developed in the framework of the EMRP-METEOMET (Metrology for Meteorology) Project, which aims is to bring metrological traceability to high altitude meteorological instruments and through this experience will provide a general overview on the importance of the application of this methodology at different levels.展开更多
Artificial Intelligence(AI)in materials science is driving significant advancements in the discovery of advanced materials for energy applications.The recent GNoME protocol identifies over 380,000 novel stable crystal...Artificial Intelligence(AI)in materials science is driving significant advancements in the discovery of advanced materials for energy applications.The recent GNoME protocol identifies over 380,000 novel stable crystals.From this,we identify over 38,500 materials with potential as energy materials forming the core of the Energy-GNoME database.Our unique combination of Machine Learning(ML)and Deep Learning(DL)tools mitigates cross-domain data bias using feature spaces,thus identifying potential candidates for thermoelectric materials,novel battery cathodes,and novel perovskites.First,classifiers with both structural and compositional features detect domains of applicability,where we expect enhanced reliability of regressors.Here,regressors are trained to predict key materials properties,like thermoelectric figure of merit(zT),band gap(E_(g)),and cathode voltage(△V_(c)).This method significantly narrows the pool of potential candidates,serving as an efficient guide for experimental and computational chemistry investigations and accelerating the discovery of materials suited for electricity generation,energy storage and conversion.展开更多
Recently,several proof of principle experiments have demonstrated the advantages of quantum technologies over classical schemes.The present challenge is to surpass the limits of proof of principle demonstrations to ap...Recently,several proof of principle experiments have demonstrated the advantages of quantum technologies over classical schemes.The present challenge is to surpass the limits of proof of principle demonstrations to approach real applications.This letter presents such an achievement in the field of quantum enhanced imaging.In particular,we describe the realization of a sub-shot-noise wide field microscope based on spatially multi-mode non-classical photon number correlations in twin beams.The microscope produces realtime images of 8000 pixels at full resolution,for a 500μm2 field of view,with noise reduced to 80%of the shot noise level(for each pixel),which is suitable for absorption imaging of complex structures.By fast post-elaboration,specifically applying a quantum enhanced median filter,the noise can be further reduced(to o30%of the shot noise level)by setting a trade-off with the resolution,thus achieving the best sensitivity per incident photon reported in absorption microscopy.展开更多
Unambiguous identification of the measurement methodologies is fundamental to reduce the uncertainty and support traceability of particle shape and size at the nanoscale. In this work, the critical aspects in atomic f...Unambiguous identification of the measurement methodologies is fundamental to reduce the uncertainty and support traceability of particle shape and size at the nanoscale. In this work, the critical aspects in atomic force microscopy measurements, that is, drawbacks on sample preparation, instrumental parameters, image pre-processing, size reconstruction, and tip enlargement, are discussed in reference to quantitative dimensional measurements on different kinds of nanoparticles (inorganic and biological) with different shapes (spherical, cylindrical, complex geometry). Once the cross-section profile is extracted, top-height measurements on isolated nanoparticles of any shape can be achieved with sub-nanometer accuracy. Lateral resolution is affected by the pixel size and shape of the probe, causing dilation in the atomic force microscopy image. For the reconstruction of critical sizes of inorganic non-spherical nanoparticles, a geometric approach that considers the nominal shape because of the synthesis conditions is presented and discussed.展开更多
Quantum entanglement and squeezing have significantly improved phase estimation and imaging in interferometric settings beyond the classical limits.However,for a wide class of non-interferometric phase imaging/retriev...Quantum entanglement and squeezing have significantly improved phase estimation and imaging in interferometric settings beyond the classical limits.However,for a wide class of non-interferometric phase imaging/retrieval methods vastly used in the classical domain,e.g.,ptychography and diffractive imaging,a demonstration of quantum advantage is still missing.Here,we fill this gap by exploiting entanglement to enhance imaging of a pure phase object in a non-interferometric setting,only measuring the phase effect on the free-propagating field.This method,based on the so-called"transport of intensity equation",is quantitative since it provides the absolute value of the phase without prior knowledge of the object and operates in wide-field mode,so it does not need time-consuming raster scanning.Moreover,it does not require spatial and temporal coherence of the incident light.Besides a general improvement of the image quality at a fixed number of photons irradiated through the object,resulting in better discrimination of small details,we demonstrate a clear reduction of the uncertainty in the quantitative phase estimation.Although we provide an experimental demonstration of a specific scheme in the visible spectrum,this research also paves the way for applications at different wavelengths,e.g.,X-ray imaging,where reducing the photon dose is of utmost importance.展开更多
Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100?In 1988 Aharonov,Albert and Vaidman argued that upon pre-and postselection of particular spin states,weakening the coup...Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100?In 1988 Aharonov,Albert and Vaidman argued that upon pre-and postselection of particular spin states,weakening the coupling of a standard measurement procedure ensures this paradoxical result1.This theoretical prediction,called weak value,was realised in numerous experiments2-9,but its meaning remains very controversialsince its"anomalous"nature,i.e.z the possibility to exceed the eigenvalue spectrum,as well as its"quantumness"are debated20-22.We address these questions by presenting the first experiment measuring anomalous weak values with just a single click,without the need for statistical averaging.The measurement uncertainty is significantly smaller than the gap between the measured weak value and the nearest eigenvalue.Beyond clarifying the meaning of weak values,demonstrating their non-statistical,single-particle nature,this result represents a breakthrough in understanding the foundations of quantum measurement,showing unprecedented measurement capability for further applications of weak values to quantum photonics.展开更多
Single-photon avalanche diodes(SPADs)are the most widespread commercial solution for single-photon counting in quantum key distribution applications.However,the secondary photon emission that arises from the avalanche...Single-photon avalanche diodes(SPADs)are the most widespread commercial solution for single-photon counting in quantum key distribution applications.However,the secondary photon emission that arises from the avalanche of charge carriers that occurs during the detection of a photon may be exploited by an eavesdropper to gain information without inducing errors in the transmission key.In this paper,we characterize such backflash light in gated InGaAs/InP SPADs and discuss its spectral and temporal characterization for different detector models and different operating parameters.We qualitatively bound the maximum information leakage due to backflash light and propose solutions for preventing such leakage.展开更多
基金carried out in the framework of the Ri ST2 Project,cofinanced by Fondazione Cassa di Risparmio di Torino。
文摘In a context of cryosphere degradation caused by climate warming,rock temperature is one of the main driving factors of rockfalls that occur on high-elevation mountain slopes.In order to improve the knowledge of this critical relationship,it is necessary to increase measurement capability of rock temperature and its variability in different lithological and slope/aspect conditions,and also to increase local scale studies,increasing the quality and the comparability of the data.This paper shows an example of metrological characterization of sensors used for rock temperature measurement in mountain regions,by means of the measurement uncertainty.Under such approach,data and results from temperature measurements carried out in the Bessanese high-elevation experimental site(Western European Alps)are illustrated.The procedures for the calibration and field characterization of sensors allow to measure temperature in different locations,depths and lithotypes,within 0.10°C of overall uncertainty.This work has highlighted that metrological traceability is fundamental to asses data quality and establish comparability among different measurements;that there are strong differences between air temperature and near-surface rock temperature;and that there are significant differences of rock temperature acquired in different aspect conditions.Finally,solar radiation,slope/aspect conditions and lithotype,seem to be the main driving factors of rock temperature.
文摘In-situ calibrations of weather stations are usually performed by positioning standard instruments close to the station under calibration and comparing the obtained results. This procedure could be useful to evaluate the proper functioning of the monitoring equipments, but do not allowed the determination of a calibration curve that allow the corrections of the acquired parameters. Thus, the development of a dedicated facility for in-situ calibration of weather stations, enabling simultaneous generation of a wide range of temperatures and pressures could offer important improvements in this framework, particularly if this facility is applied to high mountains monitoring stations where the weather stations calibrations could be very difficult. This paper will present the calibration chamber developed in the framework of the EMRP-METEOMET (Metrology for Meteorology) Project, which aims is to bring metrological traceability to high altitude meteorological instruments and through this experience will provide a general overview on the importance of the application of this methodology at different levels.
文摘Artificial Intelligence(AI)in materials science is driving significant advancements in the discovery of advanced materials for energy applications.The recent GNoME protocol identifies over 380,000 novel stable crystals.From this,we identify over 38,500 materials with potential as energy materials forming the core of the Energy-GNoME database.Our unique combination of Machine Learning(ML)and Deep Learning(DL)tools mitigates cross-domain data bias using feature spaces,thus identifying potential candidates for thermoelectric materials,novel battery cathodes,and novel perovskites.First,classifiers with both structural and compositional features detect domains of applicability,where we expect enhanced reliability of regressors.Here,regressors are trained to predict key materials properties,like thermoelectric figure of merit(zT),band gap(E_(g)),and cathode voltage(△V_(c)).This method significantly narrows the pool of potential candidates,serving as an efficient guide for experimental and computational chemistry investigations and accelerating the discovery of materials suited for electricity generation,energy storage and conversion.
文摘Recently,several proof of principle experiments have demonstrated the advantages of quantum technologies over classical schemes.The present challenge is to surpass the limits of proof of principle demonstrations to approach real applications.This letter presents such an achievement in the field of quantum enhanced imaging.In particular,we describe the realization of a sub-shot-noise wide field microscope based on spatially multi-mode non-classical photon number correlations in twin beams.The microscope produces realtime images of 8000 pixels at full resolution,for a 500μm2 field of view,with noise reduced to 80%of the shot noise level(for each pixel),which is suitable for absorption imaging of complex structures.By fast post-elaboration,specifically applying a quantum enhanced median filter,the noise can be further reduced(to o30%of the shot noise level)by setting a trade-off with the resolution,thus achieving the best sensitivity per incident photon reported in absorption microscopy.
文摘Unambiguous identification of the measurement methodologies is fundamental to reduce the uncertainty and support traceability of particle shape and size at the nanoscale. In this work, the critical aspects in atomic force microscopy measurements, that is, drawbacks on sample preparation, instrumental parameters, image pre-processing, size reconstruction, and tip enlargement, are discussed in reference to quantitative dimensional measurements on different kinds of nanoparticles (inorganic and biological) with different shapes (spherical, cylindrical, complex geometry). Once the cross-section profile is extracted, top-height measurements on isolated nanoparticles of any shape can be achieved with sub-nanometer accuracy. Lateral resolution is affected by the pixel size and shape of the probe, causing dilation in the atomic force microscopy image. For the reconstruction of critical sizes of inorganic non-spherical nanoparticles, a geometric approach that considers the nominal shape because of the synthesis conditions is presented and discussed.
文摘Quantum entanglement and squeezing have significantly improved phase estimation and imaging in interferometric settings beyond the classical limits.However,for a wide class of non-interferometric phase imaging/retrieval methods vastly used in the classical domain,e.g.,ptychography and diffractive imaging,a demonstration of quantum advantage is still missing.Here,we fill this gap by exploiting entanglement to enhance imaging of a pure phase object in a non-interferometric setting,only measuring the phase effect on the free-propagating field.This method,based on the so-called"transport of intensity equation",is quantitative since it provides the absolute value of the phase without prior knowledge of the object and operates in wide-field mode,so it does not need time-consuming raster scanning.Moreover,it does not require spatial and temporal coherence of the incident light.Besides a general improvement of the image quality at a fixed number of photons irradiated through the object,resulting in better discrimination of small details,we demonstrate a clear reduction of the uncertainty in the quantitative phase estimation.Although we provide an experimental demonstration of a specific scheme in the visible spectrum,this research also paves the way for applications at different wavelengths,e.g.,X-ray imaging,where reducing the photon dose is of utmost importance.
基金We acknowledge the European Union's Horizon 2020 and the EMPIR Participating States in the context of the projects 17FUN01"BeCOMe"and 17FUN06"SIQUST",the European Union's Horizon 2020 FET-OPEN project grant no.828946"PATHOS"the National Science Foundation--U.S.-lsrael Binational Science Foundation Grant No.735/18.+1 种基金EC was supported by Grant No.FQXi-RFPthe Quantum Science and Technology Program of the Israeli Council of Higher Educatio n,and the Pazy Foundation.
文摘Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100?In 1988 Aharonov,Albert and Vaidman argued that upon pre-and postselection of particular spin states,weakening the coupling of a standard measurement procedure ensures this paradoxical result1.This theoretical prediction,called weak value,was realised in numerous experiments2-9,but its meaning remains very controversialsince its"anomalous"nature,i.e.z the possibility to exceed the eigenvalue spectrum,as well as its"quantumness"are debated20-22.We address these questions by presenting the first experiment measuring anomalous weak values with just a single click,without the need for statistical averaging.The measurement uncertainty is significantly smaller than the gap between the measured weak value and the nearest eigenvalue.Beyond clarifying the meaning of weak values,demonstrating their non-statistical,single-particle nature,this result represents a breakthrough in understanding the foundations of quantum measurement,showing unprecedented measurement capability for further applications of weak values to quantum photonics.
基金funding from the European Union’s Horizon 2020the EMPIR and EMRP Participating States in the contexts of the projects EXL02 SIQUTE and 14IND05 MIQC2,respectivelysupport from FIRB Project No.D11J11000450001 funded by MIUR and from the NATO SPS Project 984397.
文摘Single-photon avalanche diodes(SPADs)are the most widespread commercial solution for single-photon counting in quantum key distribution applications.However,the secondary photon emission that arises from the avalanche of charge carriers that occurs during the detection of a photon may be exploited by an eavesdropper to gain information without inducing errors in the transmission key.In this paper,we characterize such backflash light in gated InGaAs/InP SPADs and discuss its spectral and temporal characterization for different detector models and different operating parameters.We qualitatively bound the maximum information leakage due to backflash light and propose solutions for preventing such leakage.
