In China, efforts are being made to monitor geoelectric fields through a large network of stations deployed and managed by the China Earthquake Administration. The diurnal variations in the geoelectric field waveforms...In China, efforts are being made to monitor geoelectric fields through a large network of stations deployed and managed by the China Earthquake Administration. The diurnal variations in the geoelectric field waveforms were similar in the quiet magnetic periods when K〈5 （generally, K〈3 indicates a quiet time）. The arrival time points of the maxima in the geoelectric field waveforms exhibited differences in local time related to geographic longitude. The amplitude of diurnal variation was several to 16.6 mV/km and decreased with increasing latitude. Further, the amplitude of diurnal variation, which was related to seasonal changes, was larger in summer and autumn than in spring and winter. The periods of diurnal changes during quiet days were 24, 12, 8, 6, 4 hours and several minutes over large areas. Finally, the observed diurnal variations in geoelectric field prior to the Alxa Zuoqi Ms5.8 earthquake on 15 April 2015 were studied, and pronounced changes in the spectral values of the geoelectric fields were found to be associated with the Alxa Zuoqi earthquake in Inner Mongolia.展开更多
We retrospectively analyzed the temporal and spatial variations of four different physical parameters characterizing the state of the atmosphere and ionosphere several days before the M9 Tohoku, Japan earthquake of Ma...We retrospectively analyzed the temporal and spatial variations of four different physical parameters characterizing the state of the atmosphere and ionosphere several days before the M9 Tohoku, Japan earthquake of March 11, 2011. The data include outgoing long wave radiation （OLR）, GPS/TEC, lower Earth orbit ionospheric tomography and critical frequency foF2. Our first results show that on March 7th a rapid increase of emitted infrared radiation was observed from the satellite data and an anomaly developed near the epicenter. The GPS/TEC data indicate an increase and variation in electron density reaching a maximum value on March 8. Starting from this day in the lower ionosphere also there was confirmed an abnormal TEC variation over the epicenter. From March 3 to 11 a large increase in electron concentration was recorded at all four Japanese ground-based ionosondes, which returned to normal after the main earthquake. The joint preliminary analysis of atmospheric and ionospheric parameters during the M9 Tohoku, Japan earthquake has revealed the presence of related variations of these parameters implying their connection with the earthquake process. This study may lead to a better understanding of the response of the atmosphere/ionosphere to the great Tohoku earthquake.展开更多
Light Detection and Ranging(LiDAR) systems can be used to estimate both vertical and horizontal forest structure.Woody components,the leaves of trees and the understory can be described with high precision,using geo-r...Light Detection and Ranging(LiDAR) systems can be used to estimate both vertical and horizontal forest structure.Woody components,the leaves of trees and the understory can be described with high precision,using geo-registered 3D-points.Based on this concept,the Effective Plant Area Indices(PAIe) for areas of Korean Pine(Pinus koraiensis),Japanese Larch(Larix leptolepis) and Oak(Quercus spp.) were estimated by calculating the ratio of intercepted and incident LIDAR laser rays for the canopies of the three forest types.Initially,the canopy gap fraction(GLiDAR) was generated by extracting the LiDAR data reflected from the canopy surface,or inner canopy area,using k-means statistics.The LiDAR-derived PAIe was then estimated by using GLIDAR with the Beer-Lambert law.A comparison of the LiDAR-derived and field-derived PAIe revealed the coefficients of determination for Korean Pine,Japanese Larch and Oak to be 0.82,0.64 and 0.59,respectively.These differences between field-based and LIDAR-based PAIe for the different forest types were attributed to the amount of leaves and branches in the forest stands.The absence of leaves,in the case of both Larch and Oak,meant that the LiDAR pulses were only reflected from branches.The probability that the LiDAR pulses are reflected from bare branches is low as compared to the reflection from branches with a high leaf density.This is because the size of the branch is smaller than the resolution across and along the 1 meter LIDAR laser track.Therefore,a better predictive accuracy would be expected for the model if the study would be repeated in late spring when the shoots and leaves of the deciduous trees begin to appear.展开更多
Entanglement has been recognized as being crucial when implementing various quantum information tasks.Nevertheless, quantifying entanglement for an unknown quantum state requires nonphysical operations or post-process...Entanglement has been recognized as being crucial when implementing various quantum information tasks.Nevertheless, quantifying entanglement for an unknown quantum state requires nonphysical operations or post-processing measurement data. For example, evaluation methods via quantum state tomography require vast amounts of measurement data and likely estimation.展开更多
The application of a gate voltage to control the superconducting current flowing through a nanoscale superconducting constriction,named as gate-controlled supercurrent(GCS),has raised great interest for fundamental an...The application of a gate voltage to control the superconducting current flowing through a nanoscale superconducting constriction,named as gate-controlled supercurrent(GCS),has raised great interest for fundamental and technological reasons.To gain a deeper understanding of this effect and develop superconducting technologies based on it,the material and physical parameters crucial for the GCS effect must be identified.Top-down fabrication protocols should also be optimized to increase device scalability,although studies suggest that top-down fabricated devices are more resilient to show a GCS.Here,we investigate gated superconducting nanobridges made with a top-down fabrication process from thin films of the noncentrosymmetric superconductor niobium rhenium with varying ratios of the constituents(NbRe).Unlike other devices previously reported and made with a top-down approach,our NbRe devices systematically exhibit a GCS effect when they were fabricated from NbRe thin films with small grain size and etched in specific conditions.These observations pave the way for the realization of top-down-made GCS devices with high scalability.Our results also imply that physical parameters like structural disorder and surface physical properties of the nanobridges,which can be in turn modified by the fabrication process,are crucial for a GCS observation,providing therefore also important insights into the physics underlying the GCS effect.展开更多
利用2003年到2010年的美国宇航局(National Aeronautics and Space Administration,NASA)的AIRS(Atmosphere InfraRed Sounder)官方反演的对流层中层(500 hPa)左右一段气柱内的CO2体积混合比产品分析中国地区对流层的CO2体积分数分布时...利用2003年到2010年的美国宇航局(National Aeronautics and Space Administration,NASA)的AIRS(Atmosphere InfraRed Sounder)官方反演的对流层中层(500 hPa)左右一段气柱内的CO2体积混合比产品分析中国地区对流层的CO2体积分数分布时空变化特征。所用数据是对AIRS L3产品2°×2.5°网格数据进行处理分析得到。经过对这8年的观测数据(2003年1月—2010年12月)的数据分析研究发现:中国地区平均CO2的体积分数在空间分布上极不平衡,总体高值集中于北部。CO2对流层中层的高值区集中在35°—45°N,形成东北平原、内蒙古中西部地区、塔克拉玛干沙漠和塔里木盆地4个高值中心,而云南地区和西藏南部上空的CO2值偏低。与中国地区8年平均CO2体积分数变化特征大体一致,每月(8年平均值)分布趋势也呈北部地区和东部地区高而南方体积分数值相对低的特征。CO2月平均体积分数的最高值一般出现在每年的4月或者5月,而每年的最低值则出现在每年的1月。对流层中层CO2体积分数呈现明显季节变化,总体上来说,从2003年到2010年这8年中,平均春、夏两季对流层中CO2含量较高,而秋、冬季CO2低于春夏两季。展开更多
Background:The biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain(LBP).Despite substantial research,it is still unclear whether consiste...Background:The biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain(LBP).Despite substantial research,it is still unclear whether consistent and generalizable changes in walking or running gait occur in association with LBP.The purpose of this systematic review was to identify whether there are differences in biomechanics during walking and running gait in individuals with acute and persistent LBP compared with back-healthy controls.Methods:A search was conducted in PubMed,CINAHL,SPORTDiscus,and PsycINFO in June 2019 and was repeated in December 2020.Studies were included if they reported biomechanical characteristics of individuals with and without LBP during steady-state or perturbed walking and running.Biomechanical data included spatiotemporal,kinematic,kinetic,and electromyography variables.The reporting quality and potential for bias of each study was assessed.Data were pooled where possible to compare the standardized mean differences(SMD)between back pain and back-healthy control groups.Results:Ninety-seven studies were included and reviewed.Two studies investigated acute pain and the rest investigated persistent pain.Nine studies investigated running gait.Of the studies,20%had high reporting quality/low risk of bias.In comparison with back-healthy controls,individuals with persistent LBP walked slower(SMD=-0.59,95%confidence interval(95%CI):-0.77 to-0.42)and with shorter stride length(SMD=-0.38,95%CI:-0.60 to-0.16).There were no differences in the amplitude of motion in the thoracic or lumbar spine,pelvis,or hips in individuals with LBP.During walking,coordination of motion between the thorax and the lumbar spine/pelvis was significantly more in-phase in the persistent LBP groups(SMD=-0.60,95%CI:-0.90 to-0.30),and individuals with persistent LBP exhibited greater amplitude of activation in the paraspinal muscles(SMD=0.52,95%CI:0.23-0.80).There were no consistent differences in running biomechanics between groups.Conclusion:The展开更多
How does the quantum-to-classical transition of measurement occur?This question is vital for both foundations and applications of quantum mechanics.Here,we develop a new measurement-based framework for characterizing ...How does the quantum-to-classical transition of measurement occur?This question is vital for both foundations and applications of quantum mechanics.Here,we develop a new measurement-based framework for characterizing the classical and quantum free electron-photon interactions and then experimentally test it.We first analyze the transition from projective to weak measurement in generic light-matter interactions and show that any classical electron-laserbeam interaction can be represented as an outcome of weak measurement.In particular,the appearance of classical point-particle acceleration is an example of an amplified weak value resulting from weak measurement.A universal factor,exp(-Γ^(2)=2),quantifies the measurement regimes and their transition from quantum to classical,whereΓcorresponds to the ratio between the electron wavepacket size and the optical wavelength.This measurement-based formulation is experimentally verified in both limits of photon-induced near-field electron microscopy and the classical acceleration regime using a DLA.Our results shed new light on the transition from quantum to classical electrodynamics,enabling us to employ the essence of the wave-particle duality of both light and electrons in quantum measurement for exploring and applying many quantum and classical light-matter interactions.展开更多
In the current era of changes unseen in a century,humanity is caught up in a deteriorating security environment on a global scale.By proposing the Global Security Initiative(GSI),China has offered its wisdom and a sol...In the current era of changes unseen in a century,humanity is caught up in a deteriorating security environment on a global scale.By proposing the Global Security Initiative(GSI),China has offered its wisdom and a solution toward building a community of shared security for humanity.After a brief review of the historical evolution of the global security mechanism,the present study analyzes the main ideas and contemporary values making up the GSI.Meanwhile,based on the approaches proposed in and the spirit of the GSI Concept Paper,the authors uncover the dialectical relationship between the GSI,the Global Development Initiative,and the Global Civilization Initiative,which are all included in the Law on Foreign Relations of the People’s Republic of China adopted on June 28,2023.Furthermore,the authors recommend three practical paths toward implementing the GSI:a path toward shortterm goals,a path toward medium-term goals,and a path toward longterm goals.The success of the GSI needs the concerted efforts of all countries.China is not only an active advocate of the GSI but has also been striving to enhance its capability in safeguarding global security,implement the GSI vigorously,and spearhead a new type of global governance.展开更多
Objective Taste impairment is prevalent among post-laryngectomy head and neck cancer survivors. Previous studies report resolution of taste changes after treatment. This study aimed to determine the taste function of ...Objective Taste impairment is prevalent among post-laryngectomy head and neck cancer survivors. Previous studies report resolution of taste changes after treatment. This study aimed to determine the taste function of post-laryngectomy head and neck cancer survivors and examine associations with dietary intake and malnutrition status. Materials and Methods Six participants (5 males and 1 female) were tested in their ability to identify solutions of the five basic tastes of bitter (caffeine), salty (sodium chloride), sour (citric acid), sweet (sucrose), and umami (monosodium glutamate) at three different concentrations in triplicate. Participants completed a 24-hour dietary recall to determine dietary intake, and were screened for positive markers of malnutrition. Results Participants had a mean time of 17?10.8 years since treatment. At the lowest concentration, 33.3% of participants identified bitter, 16.7% salty, 16.7% sour, 0% sweet, and 0% umami. No participants presented positive features of malnutrition, though 83.3% of participants’reported energy intake below recommendations. Positive correlations were found between energy intake and correct identification scores for sour at medium (P=0.003) and low (P=0.01) concentrations and for umami at low concentration (P=0.03). Conclusions As evidenced by a lack of malnutrition features and maintenance of weight status, adaptation in taste function appears to occur in post-laryngectomy head and neck cancer survivors. Interventions for taste impairment through stimulation of salivation by sour or umami taste may prevent alterations in dietary intake and maximize quality of life in this population. Further research is required to understand post-treatment taste impairment and recovery.展开更多
It is not generally known that the inequality that Bell derived using three random variables must be identically satisfied by any three corresponding data sets of ±1’s that are writable on paper. This surprising...It is not generally known that the inequality that Bell derived using three random variables must be identically satisfied by any three corresponding data sets of ±1’s that are writable on paper. This surprising fact is not immediately obvious from Bell’s inequality derivation based on causal random variables, but follows immediately if the same mathematical operations are applied to finite data sets. For laboratory data, the inequality is identically satisfied as a fact of pure algebra, and its satisfaction is independent of whether the processes generating the data are local, non-local, deterministic, random, or nonsensical. It follows that if predicted correlations violate the inequality, they represent no three cross-correlated data sets that can exist, or can be generated from valid probability models. Reported data that violate the inequality consist of probabilistically independent data-pairs and are thus inconsistent with inequality derivation. In the case of random variables as Bell assumed, the correlations in the inequality may be expressed in terms of the probabilities that give rise to them. A new inequality is then produced: The Wigner inequality, that must be satisfied by quantum mechanical probabilities in the case of Bell experiments. If that were not the case, predicted quantum probabilities and correlations would be inconsistent with basic algebra.展开更多
It is estimated that 80% of the world population depends on traditional medicine for primary healthcare need. Trianthema portulacastrum Linn.（family： Aizoaceae） is a small perennial weed found in the Americas, Afri...It is estimated that 80% of the world population depends on traditional medicine for primary healthcare need. Trianthema portulacastrum Linn.（family： Aizoaceae） is a small perennial weed found in the Americas, Africa, India, and other regions of the world. This plant is used extensively in Indian traditional medicines and is also consumed as a vegetable throughout Asia for its perceived health benefits. Phytochemical analysis of T. portulacastrum reveals the presence of alkaloids, fl avonoids, terpenoids, saponins, and phenolic compounds. Emerging studies demonstrate that crude extracts as well as bioactive phytoconstituents of T. portulacastrum exhibit potent antioxidant, anti-infective, analgesic, and anti-infl ammatory activities. A growing number of in vitro and in vivo studies demonstrate various biological and pharmacological activities, including prevention and amelioration of hepatotoxicity, nephrotoxicity, hyperglycemia, hyperlipidemia, infectious diseases and cancer. This review aims to present and analyze available literature to understand the full potential of T. portulacastrum in health promotion and disease prevention. Current limitations and future directions of research on this medicinal and dietary plant are also critically discussed.展开更多
Mural cells(MCs)wrap around the endothelium,and participate in the development and homeostasis of vasculature.MCs have been reported as heterogeneous population morphologically and functionally.However,the transcripti...Mural cells(MCs)wrap around the endothelium,and participate in the development and homeostasis of vasculature.MCs have been reported as heterogeneous population morphologically and functionally.However,the transcriptional heterogeneity of MCs was rarely studied.In this study,we illustrated the transcriptional heterogeneity of MCs with different perspectives by using publicly available single-cell dataset GSE109774.Specifically,MCs are transcriptionally different from other cell types,and ligand-receptor interactions of different cells with MCs vary.Re-clustering of MCs identified five distinct subclusters.The heterogeneity of MCs in tissues was reflected by MC coverage,various distribution of MC subclusters,and ligand-receptor interactions of MCs and parenchymal cells.The transcriptomic diversity of MCs revealed in this article will help facilitate further research into MCs.展开更多
Ever since the development of quantum mechanics in the first part of the 20th century, a new world view has emerged. Today, the physicalist objective assumption that objects exist independently of acts of observation ...Ever since the development of quantum mechanics in the first part of the 20th century, a new world view has emerged. Today, the physicalist objective assumption that objects exist independently of acts of observation has been challenged. The repercussions of this radical challenge to our common-sense perception of the world are far-reaching, although not yet generally realized. Here we argue that there is a complementary view to the way science which is being practiced, and that consciousness itself is primary and qualia form the foundation of experience. We outline the arguments of why the new science of qualia will tie objects that are being perceived to the subjective experience, through the units of subjective experience called qualia. If there is a reality that exists outside of perceptions in consciousness, it is indeed inconceivable. The reason is that once one subtracts everything that one can sense, imagine, feel, or think about, there＇s nothing left. Since qualia are subjective, they challenge the dominant world view of science as practiced today, which is reductionist, objective, and mathematical. Our view is a natural continuation of the quantum world view. We outline what the steps will have to be in order to fully develop the science of qualia.展开更多
An experiment is proposed in which the overall path taken by a photon is indicated by the timing of a twin herald photon, while a particular segment of that path is determined by interference. The needed coincident pa...An experiment is proposed in which the overall path taken by a photon is indicated by the timing of a twin herald photon, while a particular segment of that path is determined by interference. The needed coincident pairs of photons are generated by type I spontaneous-parametric-down-conversion (SPDC) and diffraction-selected by a grating at the frequency of a two-photon state. This is to be divided into two one-photon states of high coherence length. Upon experimental confirmation that their count coincidences have been maintained, the two single photons are to be used as a timing herald and source for an unequal path interferometer. A photon’s path through the interferometer via a short arm is indicated by count synchronization with the herald. The exit output port used and resulting final detection location are determined by the phase in the long arm. If output port usage can be controlled by the phase in the photon-free arm, the path of the photon as particle will have been controlled by interference with an accompanying photon-empty wave.展开更多
In eliminating the fair sampling assumption, the Greenberger, Horne, Zeilinger (GHZ) theorem is believed to confirm Bell’s historic conclusion that local hidden variables are inconsistent with the results of quantum ...In eliminating the fair sampling assumption, the Greenberger, Horne, Zeilinger (GHZ) theorem is believed to confirm Bell’s historic conclusion that local hidden variables are inconsistent with the results of quantum mechanics. The GHZ theorem depends on predicting the results of sets of measurements of which only one may be performed. In the present paper, the noncommutative aspects of these unperformed measurements are critically examined. Classical examples and the logic of the GHZ construction are analyzed to demonstrate that combined counterfactual results of noncommuting operations are in general logically inconsistent with performed measurement sequences whose results depend on noncommutation. The Bell theorem is also revisited in the light of this result. It is concluded that negative conclusions regarding local hidden variables do not follow from the GHZ and Bell theorems as historically reasoned.展开更多
In constructing his theorem, Bell assumed that correlation functions among non-commuting variables are the same as those among commuting variables. However, in quantum mechanics, multiple data values exist simultaneou...In constructing his theorem, Bell assumed that correlation functions among non-commuting variables are the same as those among commuting variables. However, in quantum mechanics, multiple data values exist simultaneously for commuting operations while for non-commuting operations data are conditional on prior outcomes, or may be predicted as alternative outcomes of the non-commuting operations. Given these qualitative differences, there is no reason why correlation functions among non-commuting variables should be the same as those among commuting variables, as assumed by Bell. When data for commuting and noncommuting operations are predicted from quantum mechanics, their correlations are different, and they now satisfy the Bell inequality.展开更多
Based on the Bell theorem, it has been believed that a theoretical computation of the Bell correlation requires explicit use of an entangled state. Such a physical superposition of light waves occurs in the down-conve...Based on the Bell theorem, it has been believed that a theoretical computation of the Bell correlation requires explicit use of an entangled state. Such a physical superposition of light waves occurs in the down-converter sources used in Bell experiments. However, this physical superposition is eliminated by wave propagation to spatially separated detectors. Bell correlations must therefore result from local waves, and the source boundary conditions of their previously entangled state. In the present model, Bell correlations are computed from disentangled separated waves, boundary conditions of nonlinear optics, and properties of single-photon and vacuum states specified by quantum electrodynamics. Transient interference is assumed between photon-excited waves and photon-empty waves based on the possibility of such interference found to be necessary by the designers of Bell-experiment sources. The present model employs local random variables without specifying underlying causality.展开更多
基金supported by the National Natural Science Foundation of China (No. 41374080)
文摘In China, efforts are being made to monitor geoelectric fields through a large network of stations deployed and managed by the China Earthquake Administration. The diurnal variations in the geoelectric field waveforms were similar in the quiet magnetic periods when K〈5 （generally, K〈3 indicates a quiet time）. The arrival time points of the maxima in the geoelectric field waveforms exhibited differences in local time related to geographic longitude. The amplitude of diurnal variation was several to 16.6 mV/km and decreased with increasing latitude. Further, the amplitude of diurnal variation, which was related to seasonal changes, was larger in summer and autumn than in spring and winter. The periods of diurnal changes during quiet days were 24, 12, 8, 6, 4 hours and several minutes over large areas. Finally, the observed diurnal variations in geoelectric field prior to the Alxa Zuoqi Ms5.8 earthquake on 15 April 2015 were studied, and pronounced changes in the spectral values of the geoelectric fields were found to be associated with the Alxa Zuoqi earthquake in Inner Mongolia.
基金NASA Goddard Space Flight Center,Chapman University and European Framework program #7 project PREEARTHQUAKE for their kind support
文摘We retrospectively analyzed the temporal and spatial variations of four different physical parameters characterizing the state of the atmosphere and ionosphere several days before the M9 Tohoku, Japan earthquake of March 11, 2011. The data include outgoing long wave radiation （OLR）, GPS/TEC, lower Earth orbit ionospheric tomography and critical frequency foF2. Our first results show that on March 7th a rapid increase of emitted infrared radiation was observed from the satellite data and an anomaly developed near the epicenter. The GPS/TEC data indicate an increase and variation in electron density reaching a maximum value on March 8. Starting from this day in the lower ionosphere also there was confirmed an abnormal TEC variation over the epicenter. From March 3 to 11 a large increase in electron concentration was recorded at all four Japanese ground-based ionosondes, which returned to normal after the main earthquake. The joint preliminary analysis of atmospheric and ionospheric parameters during the M9 Tohoku, Japan earthquake has revealed the presence of related variations of these parameters implying their connection with the earthquake process. This study may lead to a better understanding of the response of the atmosphere/ionosphere to the great Tohoku earthquake.
基金supported by a grant from the High Tech Urban Development Program funded by Ministry of Land,Transportation and Maritime Affairs of Korean government (Grant No. 07High Tech A01)a research grant from the Korea Science and Engineering Foundation (KOSEF) (Grant No. A307-K001)
文摘Light Detection and Ranging(LiDAR) systems can be used to estimate both vertical and horizontal forest structure.Woody components,the leaves of trees and the understory can be described with high precision,using geo-registered 3D-points.Based on this concept,the Effective Plant Area Indices(PAIe) for areas of Korean Pine(Pinus koraiensis),Japanese Larch(Larix leptolepis) and Oak(Quercus spp.) were estimated by calculating the ratio of intercepted and incident LIDAR laser rays for the canopies of the three forest types.Initially,the canopy gap fraction(GLiDAR) was generated by extracting the LiDAR data reflected from the canopy surface,or inner canopy area,using k-means statistics.The LiDAR-derived PAIe was then estimated by using GLIDAR with the Beer-Lambert law.A comparison of the LiDAR-derived and field-derived PAIe revealed the coefficients of determination for Korean Pine,Japanese Larch and Oak to be 0.82,0.64 and 0.59,respectively.These differences between field-based and LIDAR-based PAIe for the different forest types were attributed to the amount of leaves and branches in the forest stands.The absence of leaves,in the case of both Larch and Oak,meant that the LiDAR pulses were only reflected from branches.The probability that the LiDAR pulses are reflected from bare branches is low as compared to the reflection from branches with a high leaf density.This is because the size of the branch is smaller than the resolution across and along the 1 meter LIDAR laser track.Therefore,a better predictive accuracy would be expected for the model if the study would be repeated in late spring when the shoots and leaves of the deciduous trees begin to appear.
基金National Natural Science Foundation of China (11821404, 12004358, 61725504, U19A2075)Postdoctoral Innovative Talents Support Program(BX20230349)+6 种基金Innovation Program for Quantum Science and Technology (2021ZD0301400, 2021ZD0301200)Anhui Initiative in Quantum Information Technologies(AHY060300)JSPS KAKENHI (17K05082, 18KK0079,19H05156)JSPS PRESTO (JPMJPR20M4)Fundamental Research Funds for the Central Universities(WK2030000085, 202041012, 841912027)Natural Science Foundation of Shandong Province (ZR2021ZD19)Young Talents Project at Ocean University of China(861901013107)。
文摘Entanglement has been recognized as being crucial when implementing various quantum information tasks.Nevertheless, quantifying entanglement for an unknown quantum state requires nonphysical operations or post-processing measurement data. For example, evaluation methods via quantum state tomography require vast amounts of measurement data and likely estimation.
基金the European Union’s Horizon 2020 Research and Innovation Program under Grant Agreement No.964398(SuperGate)the US ONR(Nos.N00014-21-1-2879,N00014-20-1-2442,and N00014-23-1-2866).
文摘The application of a gate voltage to control the superconducting current flowing through a nanoscale superconducting constriction,named as gate-controlled supercurrent(GCS),has raised great interest for fundamental and technological reasons.To gain a deeper understanding of this effect and develop superconducting technologies based on it,the material and physical parameters crucial for the GCS effect must be identified.Top-down fabrication protocols should also be optimized to increase device scalability,although studies suggest that top-down fabricated devices are more resilient to show a GCS.Here,we investigate gated superconducting nanobridges made with a top-down fabrication process from thin films of the noncentrosymmetric superconductor niobium rhenium with varying ratios of the constituents(NbRe).Unlike other devices previously reported and made with a top-down approach,our NbRe devices systematically exhibit a GCS effect when they were fabricated from NbRe thin films with small grain size and etched in specific conditions.These observations pave the way for the realization of top-down-made GCS devices with high scalability.Our results also imply that physical parameters like structural disorder and surface physical properties of the nanobridges,which can be in turn modified by the fabrication process,are crucial for a GCS observation,providing therefore also important insights into the physics underlying the GCS effect.
文摘利用2003年到2010年的美国宇航局(National Aeronautics and Space Administration,NASA)的AIRS(Atmosphere InfraRed Sounder)官方反演的对流层中层(500 hPa)左右一段气柱内的CO2体积混合比产品分析中国地区对流层的CO2体积分数分布时空变化特征。所用数据是对AIRS L3产品2°×2.5°网格数据进行处理分析得到。经过对这8年的观测数据(2003年1月—2010年12月)的数据分析研究发现:中国地区平均CO2的体积分数在空间分布上极不平衡,总体高值集中于北部。CO2对流层中层的高值区集中在35°—45°N,形成东北平原、内蒙古中西部地区、塔克拉玛干沙漠和塔里木盆地4个高值中心,而云南地区和西藏南部上空的CO2值偏低。与中国地区8年平均CO2体积分数变化特征大体一致,每月(8年平均值)分布趋势也呈北部地区和东部地区高而南方体积分数值相对低的特征。CO2月平均体积分数的最高值一般出现在每年的4月或者5月,而每年的最低值则出现在每年的1月。对流层中层CO2体积分数呈现明显季节变化,总体上来说,从2003年到2010年这8年中,平均春、夏两季对流层中CO2含量较高,而秋、冬季CO2低于春夏两季。
文摘Background:The biomechanics of the trunk and lower limbs during walking and running gait are frequently assessed in individuals with low back pain(LBP).Despite substantial research,it is still unclear whether consistent and generalizable changes in walking or running gait occur in association with LBP.The purpose of this systematic review was to identify whether there are differences in biomechanics during walking and running gait in individuals with acute and persistent LBP compared with back-healthy controls.Methods:A search was conducted in PubMed,CINAHL,SPORTDiscus,and PsycINFO in June 2019 and was repeated in December 2020.Studies were included if they reported biomechanical characteristics of individuals with and without LBP during steady-state or perturbed walking and running.Biomechanical data included spatiotemporal,kinematic,kinetic,and electromyography variables.The reporting quality and potential for bias of each study was assessed.Data were pooled where possible to compare the standardized mean differences(SMD)between back pain and back-healthy control groups.Results:Ninety-seven studies were included and reviewed.Two studies investigated acute pain and the rest investigated persistent pain.Nine studies investigated running gait.Of the studies,20%had high reporting quality/low risk of bias.In comparison with back-healthy controls,individuals with persistent LBP walked slower(SMD=-0.59,95%confidence interval(95%CI):-0.77 to-0.42)and with shorter stride length(SMD=-0.38,95%CI:-0.60 to-0.16).There were no differences in the amplitude of motion in the thoracic or lumbar spine,pelvis,or hips in individuals with LBP.During walking,coordination of motion between the thorax and the lumbar spine/pelvis was significantly more in-phase in the persistent LBP groups(SMD=-0.60,95%CI:-0.90 to-0.30),and individuals with persistent LBP exhibited greater amplitude of activation in the paraspinal muscles(SMD=0.52,95%CI:0.23-0.80).There were no consistent differences in running biomechanics between groups.Conclusion:The
基金We thank Eilon Poem for helpful discussions,and we also thank Zhaopin Chen and Qingqing Cheng for their help in improving the figures.The work was supported in part by the Israel Innovation Authority Grants No.70002 and 73795,FQXi Grant No.224321Pazy Foundation,Israeli Ministry of Science and Technology,Canada Research Chair and Ontario’s Early Researcher Award,DIP(German-Israeli Project Cooperation),ISF(Israel Science Foundation)Grant No.00010001000,I-CORE-Israel Center of Research Excellence program of the ISFby the Crown Photonics Center,Gordon,and Betty Moore Foundation grant 4744(ACHIP),and ERC Advanced Grant 884217(AccelOnChip).
文摘How does the quantum-to-classical transition of measurement occur?This question is vital for both foundations and applications of quantum mechanics.Here,we develop a new measurement-based framework for characterizing the classical and quantum free electron-photon interactions and then experimentally test it.We first analyze the transition from projective to weak measurement in generic light-matter interactions and show that any classical electron-laserbeam interaction can be represented as an outcome of weak measurement.In particular,the appearance of classical point-particle acceleration is an example of an amplified weak value resulting from weak measurement.A universal factor,exp(-Γ^(2)=2),quantifies the measurement regimes and their transition from quantum to classical,whereΓcorresponds to the ratio between the electron wavepacket size and the optical wavelength.This measurement-based formulation is experimentally verified in both limits of photon-induced near-field electron microscopy and the classical acceleration regime using a DLA.Our results shed new light on the transition from quantum to classical electrodynamics,enabling us to employ the essence of the wave-particle duality of both light and electrons in quantum measurement for exploring and applying many quantum and classical light-matter interactions.
文摘In the current era of changes unseen in a century,humanity is caught up in a deteriorating security environment on a global scale.By proposing the Global Security Initiative(GSI),China has offered its wisdom and a solution toward building a community of shared security for humanity.After a brief review of the historical evolution of the global security mechanism,the present study analyzes the main ideas and contemporary values making up the GSI.Meanwhile,based on the approaches proposed in and the spirit of the GSI Concept Paper,the authors uncover the dialectical relationship between the GSI,the Global Development Initiative,and the Global Civilization Initiative,which are all included in the Law on Foreign Relations of the People’s Republic of China adopted on June 28,2023.Furthermore,the authors recommend three practical paths toward implementing the GSI:a path toward shortterm goals,a path toward medium-term goals,and a path toward longterm goals.The success of the GSI needs the concerted efforts of all countries.China is not only an active advocate of the GSI but has also been striving to enhance its capability in safeguarding global security,implement the GSI vigorously,and spearhead a new type of global governance.
文摘Objective Taste impairment is prevalent among post-laryngectomy head and neck cancer survivors. Previous studies report resolution of taste changes after treatment. This study aimed to determine the taste function of post-laryngectomy head and neck cancer survivors and examine associations with dietary intake and malnutrition status. Materials and Methods Six participants (5 males and 1 female) were tested in their ability to identify solutions of the five basic tastes of bitter (caffeine), salty (sodium chloride), sour (citric acid), sweet (sucrose), and umami (monosodium glutamate) at three different concentrations in triplicate. Participants completed a 24-hour dietary recall to determine dietary intake, and were screened for positive markers of malnutrition. Results Participants had a mean time of 17?10.8 years since treatment. At the lowest concentration, 33.3% of participants identified bitter, 16.7% salty, 16.7% sour, 0% sweet, and 0% umami. No participants presented positive features of malnutrition, though 83.3% of participants’reported energy intake below recommendations. Positive correlations were found between energy intake and correct identification scores for sour at medium (P=0.003) and low (P=0.01) concentrations and for umami at low concentration (P=0.03). Conclusions As evidenced by a lack of malnutrition features and maintenance of weight status, adaptation in taste function appears to occur in post-laryngectomy head and neck cancer survivors. Interventions for taste impairment through stimulation of salivation by sour or umami taste may prevent alterations in dietary intake and maximize quality of life in this population. Further research is required to understand post-treatment taste impairment and recovery.
文摘It is not generally known that the inequality that Bell derived using three random variables must be identically satisfied by any three corresponding data sets of ±1’s that are writable on paper. This surprising fact is not immediately obvious from Bell’s inequality derivation based on causal random variables, but follows immediately if the same mathematical operations are applied to finite data sets. For laboratory data, the inequality is identically satisfied as a fact of pure algebra, and its satisfaction is independent of whether the processes generating the data are local, non-local, deterministic, random, or nonsensical. It follows that if predicted correlations violate the inequality, they represent no three cross-correlated data sets that can exist, or can be generated from valid probability models. Reported data that violate the inequality consist of probabilistically independent data-pairs and are thus inconsistent with inequality derivation. In the case of random variables as Bell assumed, the correlations in the inequality may be expressed in terms of the probabilities that give rise to them. A new inequality is then produced: The Wigner inequality, that must be satisfied by quantum mechanical probabilities in the case of Bell experiments. If that were not the case, predicted quantum probabilities and correlations would be inconsistent with basic algebra.
文摘It is estimated that 80% of the world population depends on traditional medicine for primary healthcare need. Trianthema portulacastrum Linn.（family： Aizoaceae） is a small perennial weed found in the Americas, Africa, India, and other regions of the world. This plant is used extensively in Indian traditional medicines and is also consumed as a vegetable throughout Asia for its perceived health benefits. Phytochemical analysis of T. portulacastrum reveals the presence of alkaloids, fl avonoids, terpenoids, saponins, and phenolic compounds. Emerging studies demonstrate that crude extracts as well as bioactive phytoconstituents of T. portulacastrum exhibit potent antioxidant, anti-infective, analgesic, and anti-infl ammatory activities. A growing number of in vitro and in vivo studies demonstrate various biological and pharmacological activities, including prevention and amelioration of hepatotoxicity, nephrotoxicity, hyperglycemia, hyperlipidemia, infectious diseases and cancer. This review aims to present and analyze available literature to understand the full potential of T. portulacastrum in health promotion and disease prevention. Current limitations and future directions of research on this medicinal and dietary plant are also critically discussed.
基金supported in part by the National Key Research and Development Program of China(2019YFA0802700,2017YFA0103700)the National Natural Science Foundation of China(91739301,91339205,81130005)。
文摘Mural cells(MCs)wrap around the endothelium,and participate in the development and homeostasis of vasculature.MCs have been reported as heterogeneous population morphologically and functionally.However,the transcriptional heterogeneity of MCs was rarely studied.In this study,we illustrated the transcriptional heterogeneity of MCs with different perspectives by using publicly available single-cell dataset GSE109774.Specifically,MCs are transcriptionally different from other cell types,and ligand-receptor interactions of different cells with MCs vary.Re-clustering of MCs identified five distinct subclusters.The heterogeneity of MCs in tissues was reflected by MC coverage,various distribution of MC subclusters,and ligand-receptor interactions of MCs and parenchymal cells.The transcriptomic diversity of MCs revealed in this article will help facilitate further research into MCs.
文摘Ever since the development of quantum mechanics in the first part of the 20th century, a new world view has emerged. Today, the physicalist objective assumption that objects exist independently of acts of observation has been challenged. The repercussions of this radical challenge to our common-sense perception of the world are far-reaching, although not yet generally realized. Here we argue that there is a complementary view to the way science which is being practiced, and that consciousness itself is primary and qualia form the foundation of experience. We outline the arguments of why the new science of qualia will tie objects that are being perceived to the subjective experience, through the units of subjective experience called qualia. If there is a reality that exists outside of perceptions in consciousness, it is indeed inconceivable. The reason is that once one subtracts everything that one can sense, imagine, feel, or think about, there＇s nothing left. Since qualia are subjective, they challenge the dominant world view of science as practiced today, which is reductionist, objective, and mathematical. Our view is a natural continuation of the quantum world view. We outline what the steps will have to be in order to fully develop the science of qualia.
文摘An experiment is proposed in which the overall path taken by a photon is indicated by the timing of a twin herald photon, while a particular segment of that path is determined by interference. The needed coincident pairs of photons are generated by type I spontaneous-parametric-down-conversion (SPDC) and diffraction-selected by a grating at the frequency of a two-photon state. This is to be divided into two one-photon states of high coherence length. Upon experimental confirmation that their count coincidences have been maintained, the two single photons are to be used as a timing herald and source for an unequal path interferometer. A photon’s path through the interferometer via a short arm is indicated by count synchronization with the herald. The exit output port used and resulting final detection location are determined by the phase in the long arm. If output port usage can be controlled by the phase in the photon-free arm, the path of the photon as particle will have been controlled by interference with an accompanying photon-empty wave.
文摘In eliminating the fair sampling assumption, the Greenberger, Horne, Zeilinger (GHZ) theorem is believed to confirm Bell’s historic conclusion that local hidden variables are inconsistent with the results of quantum mechanics. The GHZ theorem depends on predicting the results of sets of measurements of which only one may be performed. In the present paper, the noncommutative aspects of these unperformed measurements are critically examined. Classical examples and the logic of the GHZ construction are analyzed to demonstrate that combined counterfactual results of noncommuting operations are in general logically inconsistent with performed measurement sequences whose results depend on noncommutation. The Bell theorem is also revisited in the light of this result. It is concluded that negative conclusions regarding local hidden variables do not follow from the GHZ and Bell theorems as historically reasoned.
文摘In constructing his theorem, Bell assumed that correlation functions among non-commuting variables are the same as those among commuting variables. However, in quantum mechanics, multiple data values exist simultaneously for commuting operations while for non-commuting operations data are conditional on prior outcomes, or may be predicted as alternative outcomes of the non-commuting operations. Given these qualitative differences, there is no reason why correlation functions among non-commuting variables should be the same as those among commuting variables, as assumed by Bell. When data for commuting and noncommuting operations are predicted from quantum mechanics, their correlations are different, and they now satisfy the Bell inequality.
文摘Based on the Bell theorem, it has been believed that a theoretical computation of the Bell correlation requires explicit use of an entangled state. Such a physical superposition of light waves occurs in the down-converter sources used in Bell experiments. However, this physical superposition is eliminated by wave propagation to spatially separated detectors. Bell correlations must therefore result from local waves, and the source boundary conditions of their previously entangled state. In the present model, Bell correlations are computed from disentangled separated waves, boundary conditions of nonlinear optics, and properties of single-photon and vacuum states specified by quantum electrodynamics. Transient interference is assumed between photon-excited waves and photon-empty waves based on the possibility of such interference found to be necessary by the designers of Bell-experiment sources. The present model employs local random variables without specifying underlying causality.
