期刊文献+
共找到9,270篇文章
< 1 2 250 >
每页显示 20 50 100
Correlation between the rock mass properties and maximum horizontal stress:A case study of overcoring stress measurements
1
作者 Peng Li Meifeng Cai +2 位作者 Shengjun Miao Yuan Li Yu Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期39-48,共10页
Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stre... Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude.To investigate the correlation between the rock mass properties and maximum horizontal stress,the three-dimensional(3D)stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted,a newly defined characteristic parameter C_(ERP)was proposed as an indicator for evaluating the structural properties of rock masses,and a fuzzy relation matrix was established using the information distribution method.The results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with depth.There is no remarkable correlation between the elastic modulus,Poisson's ratio and depth,and the distribution of data points is scattered and messy.Moreover,there is no obvious relationship between the rock quality designation(RQD)and depth.The maximum horizontal stress σ_(H) is a function of rock properties,showing a certain linear relationship with the C_(ERP)at the same depth.In addition,the overall change trend of σ_(H) determined by the established fuzzy identification method is to increase with the increase of C_(ERP).The fuzzy identification method also demonstrates a relatively detailed local relationship betweenσ_H and C_(ERP),and the predicted curve rises in a fluctuating way,which is in accord well with the measured stress data. 展开更多
关键词 overcoring stress measurements elastic modulus Poisson's ratio rock quality designation maximum horizontal stress fuzzy identification
在线阅读 下载PDF
Accurate Measurements and Error Analysis of Bi_(2)Te_(3)-Based Low-Temperature Thermoelectrics
2
作者 Jie Zhang Yixuan Ge +9 位作者 Minhua Huang Xiaohan Qin Chao Xin Linhan Wang Wenfeng Du Tianbo Lu Huaizhou Zhao Wenjie Liang Yongjun Cao Guodong Li 《Chinese Physics Letters》 2025年第5期100-116,共17页
The accurate characterization of thermoelectric properties at low temperatures is crucial for the development of high-performance thermoelectric cooling devices. While measurement errors of thermoelectric properties a... The accurate characterization of thermoelectric properties at low temperatures is crucial for the development of high-performance thermoelectric cooling devices. While measurement errors of thermoelectric properties at temperatures above room temperature have been extensively discussed, there is a lack of standard measurement protocols and error analyses for low-temperature transport properties. In this study, we present a measurement system capable of characterizing all three key thermoelectric parameters, i.e., Seebeck coefficient, electrical conductivity, and thermal conductivity, for a single sample across a temperature range of 10 K to 300 K. We investigated six representative commercial Bi_(2)Te_(3)-based samples(three N-type and three P-type). Using an error propagation model, we systematically analyzed the measurement uncertainties of the three intrinsic parameters and the resulting thermoelectric figure of merit. Our findings reveal that measurement uncertainties for both N-type and P-type Bi_(2)Te_(3)-based materials can be effectively maintained below 5% in the temperature range of 40 K to 300 K. However, the uncertainties increase to over 10% at lower temperatures, primarily due to the relatively smaller values of electrical resistivity and Seebeck coefficients in this regime. This work establishes foundational data for Bi_(2)Te_(3)-based thermoelectric materials and provides a framework for broader investigations of advanced low-temperature thermoelectrics. 展开更多
关键词 measurement system thermoelectric parameters low temperature measurements thermoelectric properties thermoelectric cooling devices error analyses standard measurement protocols characterization thermoelectric properties
原文传递
Spatiotemporal variations of sea ice kinematics in the Transpolar Drift of the Arctic Ocean in 2019/2020 derived from buoy measurements during MOSAiC
3
作者 LIU Minghao LEI Ruibo +1 位作者 LI Na CHENG Xuhua 《Advances in Polar Science》 2025年第2期137-151,共15页
Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate... Using nine ice-tethered buoys deployed across the marginal ice zone(MIZ)and pack ice zone(PIZ)north of the Laptev Sea during the expedition of the Multidisciplinary drifting Observatory for the Study of Arctic Climate(MOSAiC)in 2019-2020,we characterized the spatiotemporal variations in sea ice kinematics and deformation between October 2019 and July 2020 in the Transpolar Drift(TPD).From October to November,the buoys were in the upstream area of the TPD;spatial variations of deformation rates were significantly correlated with initial ice thickness(R=−0.84,P<0.05).From December 2019 to March 2020,the buoys were in the high Arctic and the ice cover was consolidated;heterogeneity in ice kinematics as measured across the buoys reduced by 65%.From April to May 2020,the buoys were in the downstream TPD;amplified spatial variations in ice kinematics were observed.This is because two buoys had drifted over the shallow waters north of Svalbard earlier;trajectory-stretching exponents derived from the data from these two buoys indicate deformation rates(10.6 d^(−1))that were about twice those in the deep basin(4.2 d^(−1)).By June 2020,a less consolidated ice pack and enhanced tidal forcing in the Fram Strait MIZ resulted in ice deformation with a semi-diurnal power spectral density of>0.25 d^(−1),which is about 1.5 times that in PIZ.Therefore,in both the upstream and downstream regions of the TPD,the transition between the MIZ and the PIZ contributes to the spatial and seasonal variations of sea ice motion and deformation.The results from this study can be used to support the characterization of the momentum balance and influencing factors during the ice advection along the TPD,which is a crucial corridor for Arctic sea ice outflow to the north Atlantic Ocean. 展开更多
关键词 sea ice motion sea ice deformation Arctic Ocean buoy measurements MOSAIC
在线阅读 下载PDF
Enhanced GPS Measurements Simulation for Space-oriented Navigation System Design 被引量:3
4
作者 王立端 翟传润 +1 位作者 靳文瑞 战兴群 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2010年第4期438-446,共9页
At the stage of preliminary scheme and algorithm design for spaceborne navigation systems, a precise and high-fidelity software global positioning system (GPS) simulator is a necessary and feasible testing facility ... At the stage of preliminary scheme and algorithm design for spaceborne navigation systems, a precise and high-fidelity software global positioning system (GPS) simulator is a necessary and feasible testing facility in laboratory environments, with consideration of the tradeoffs where possible. This article presents a software GPS measurements simulator on the L1 C/A code and carrier signal for space-oriented navigation system design. The simulator, coded in MATLAB language, generates both C/A code pseudorange and carrier phase measurements. Mathematical models in the Earth centered inertial (ECI) frame are formulated to simulate the GPS constellation and to generate GPS measurements. A series of efficient measures are investigated and utilized to rationalize the enhanced simulator, in terms of ephemeris data selection, space ionospheric model and range rate calculation, etc. Such an enhanced simulator has been facilitating our current work for designing a space integrated GPS/inertial navigation system (INS) navigation system. Consequently, it will promote our future research on space-oriented navigation system. 展开更多
关键词 global positioning system pseudorange carrier phase measurements simulator space applications navigation systems
原文传递
Effects of noise on fluidized bed characteristics measurements by electrical capacitance tomography
5
作者 Kai Huang Chunlei Pei +4 位作者 Shuanghe Meng Wuqiang Yang Hua Li Mao Ye Jinlong Gong 《Chinese Journal of Chemical Engineering》 2025年第3期219-233,共15页
Noise is inevitable in electrical capacitance tomography(ECT)measurements.This paper describes the influence of noise on ECT performance for measuring gas-solids fluidized bed characteristics.The noise distribution is... Noise is inevitable in electrical capacitance tomography(ECT)measurements.This paper describes the influence of noise on ECT performance for measuring gas-solids fluidized bed characteristics.The noise distribution is approximated by the Gaussian distribution and added to experimental capacitance data with various intensities.The equivalent signal strength(Ф)that equals the signal-to-noise ratio of packed beds is used to evaluate noise levels.Results show that the Pearson correlation coefficient,which indicates the similarity of solids fraction distributions over pixels,increases with Ф,and reconstructed images are more deteriorated at lower Ф.Nevertheless,relative errors for average solids fraction and bubble size in each frame are less sensitive to noise,attributed to noise compromise caused by the process of pixel values.These findings provide useful guidance for assessing the accuracy of ECT measurements of multiphase flows. 展开更多
关键词 Noise Electrical capacitance tomography Fluidized bed Signal-to-noise ratio MEASUREMENT
在线阅读 下载PDF
Effects of advancing tunnel on a loaded pile:Numerical analysis and field measurements
6
作者 Cheemin Khoo Hisham Mohamad +3 位作者 Aizat Akmal A.Mohamad Beddelee Phromphat Thansirichaisree Muhammad Farid Ghazali Muhammad Yusoff Mohd Nasir 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第10期6145-6158,共14页
A full-scale research study was conducted during the bored tunnelling of the Klang Valley Mass Rapid Transit-Putrajaya Line beneath an existing building structure in Kuala Lumpur,Malaysia.The primary objective was to ... A full-scale research study was conducted during the bored tunnelling of the Klang Valley Mass Rapid Transit-Putrajaya Line beneath an existing building structure in Kuala Lumpur,Malaysia.The primary objective was to investigate the tunnel-soil-pile interaction at various stages of tunnel excavation.This study combined field measurements and three-dimensional(3D)numerical analysis to understand the transient effects of TBM tunnelling on a loaded pile.An experimental pile was instrumented with vibrating wire strain gauges,an inclinometer,and distributed fibre optic sensors using Brillouin optical time domain analysis.The pile was pre-loaded and continuously monitored in real-time throughout the tunnel construction process.The 3D finite element modelling was used to simulate the pile’s transient responses based on actual tunnel boring machine(TBM)driving data.The study revealed that the zone of influence due to tunnelling effects extended from y¼2D to y¼4D,with the peak effect observed at y¼1D to 1.5D,where D represents the tunnel diameter.The analysis of axial load patterns highlighted transient responses,including tensile loads below the tunnel invert,which propagated upward and subsided due to negative skin friction.The maximum downdrag load observed reached 56%e71%of the pile’s working load.Additionally,pile movement patterns indicated outward deflections as the TBM approached and a return toward the tunnel post-passage,aligning with the predicted behaviour in a negative face loss scenario.This validated numerical framework provides a solid foundation for further parametric studies and enhances the understanding of tunnel-soil-pile interactions. 展开更多
关键词 Field measurement Numerical analysis Tunnel-soil-pile interaction Transient effects Pile responses
在线阅读 下载PDF
Density measurements of aviation kerosene RP-3 over temperature range from 323 K to 783 K under supercritical pressures from 6 MPa to 8 MPa
7
作者 Yanchen FU Weitong LIU +3 位作者 Shenzhou SHI Ruoyu WANG Yinlong LIU Guoqiang XU 《Chinese Journal of Aeronautics》 2025年第7期115-124,共10页
Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The... Aviation kerosene RP-3 is extensively used in China.This paper details the measurement of the density of Chinese aviation kerosene RP-3 employing the flow method under high-pressure and high-temperature conditions.The methodology utilizes circular tubes with two different diameters.The density of aviation kerosene RP-3 was experimentally measured for the first time within a pressure range from 6 MPa to 8 MPa and a temperature range from 323 K to 783 K,with a maximum relative uncertainty of 0.35%.The experimental setup used n-decane for calibration,achieving an average calibration error of 0.91%.The data indicate that the density of RP-3 ranges from 764 kg/m^(3)to 247 kg/m^(3)under the tested conditions.The results show that the density of kerosene RP-3 decreases with an increase in temperature at a constant pressure,and at a given temperature,a higher pressure results in a higher density.Polynomial fitting was applied to the data,resulting in the average absolute deviation of 1.09%,0.80%,and 0.76%at different pressures of 6,7,and 8 MPa,respectively. 展开更多
关键词 Aviation kerosene Density measurement High temperature Supercritical pressure Thermal properties
原文传递
Learning models for predicting pavement friction based on non-contact texture measurements: Comparative assessment
8
作者 Xiuquan Lin You Zhan +3 位作者 Zilong Nie Joshua Qiang Li Xinyu Zhu Allen A.Zhang 《Journal of Road Engineering》 2025年第2期202-212,共11页
Ensuring highway safety relies heavily on pavement friction resistance.To enable network-level pavement skid resistance monitoring and management,this study proposes a non-contact three-dimensional laser surface testi... Ensuring highway safety relies heavily on pavement friction resistance.To enable network-level pavement skid resistance monitoring and management,this study proposes a non-contact three-dimensional laser surface testing method to obtain detailed aggregate surface data.The existing contact-based skid resistance measurement methods suffer from poor reproducibility and repeatability,hindering their application for network-level management.In this research,traditional multiple linear regression and four machine learning methods,support vector machine(SVM),random forest(RF),gradient boosting decision tree(GBDT),and convolutional neural network(CNN),are utilized to evaluate and predict pavement frictional performance.To assess the proposed methods,data from 45 pavement sites in Oklahoma,including 6 major preventive maintenance(PM)treatments and 7 typical types of aggregates,are collected.Parallel data acquisition is conducted at highway speeds using a grip tester and a high-speed texture profiler to measure pavement skid resistance and surface macro-texture,respectively.Aggregate properties are captured in 3D using a portable ultra-high-resolution 3D laser imaging scanner,leading to the calculation of four types of 3D aggregate parameters characterizing the micro-texture of aggregate surfaces.The relationship between pavement surface friction and texture is explored using machine learning models.The results reveal that the random forest and gradient boosting decision tree models exhibit the highest accuracy,SVM and CNN perform moderately,while the traditional linear regression method fares the worst.By assessing the importance of the 38 parameter variables,the most critical 21 variables were selected for model development.Test results demonstrate that the GBDT model exhibits the best predictive performance,with an explanatory capability of 87.4%for road friction performance.The findings demonstrate the feasibility of replacing contact-based pavement friction evaluation with non-contact texture measurements,offering promising prospects for a network-level pavement skid resistance monitoring and management system. 展开更多
关键词 PAVEMENT Skid resistance Non-contact texture measurement Machine learning
在线阅读 下载PDF
Evaluating tree branch angle measurements of European beech using terrestrial laser scanning
9
作者 Xi Peng Kim Calders +1 位作者 Louise Terryn Hans Verbeeck 《Forest Ecosystems》 2025年第2期220-230,共11页
Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements u... Branch angles are an important plant morphological trait affecting light interception within forest canopies.However,studies on branch angles have been limited due to the time-consuming nature of manual measurements using a protractor.Terrestrial laser scanning(TLS),however,provides new opportunities to measure branch angles more efficiently.Despite this potential,studies validating branch angle measurements from TLS have been limited.Here,our aim is to evaluate both manual and automatic branch angle measurements of European beech from TLS data using traditional field-measurements with a protractor as a reference.We evaluated the accuracy of branch angle measurements based on four automated algorithms(aRchiQSM,TreeQSM,Laplacian,SemanticLaplacian)from TLS data.Additionally,we assessed different ways of manual branch angle measurements in the field.Our study was based on a dataset comprising 124 branch angles measured from six European beech in a European deciduous forest.Our results show that manual branch angle measurements from TLS data are in high agreement with the reference(root-mean-squared error,RMSE:[3.57°-4.18°],concordance correlation coefficient,CCC:[0.950.97])across different branch length positions.Automated algorithms also are in high agreement with the reference although RMSE is approximately twice as large compared to manual branch angle measurements from TLS(RMSE:[9.29°-10.55°],CCC:[0.830.86])with manual leaf points removal.When applying the automatic wood-leaf separation algorithm,the performance of the four methods declined significantly,with only approximately 20 branch angles successfully identified.Moreover,it is important to note that there is no influence of the measurement position(branch surface versus center)for branch angle measurements.However,for curved branches,the selection of branch measurement length significantly impacts the branch angle measurement.This study provides a comprehensive understanding of branch angle measurements in forests.We show that automated measurement methods based on TLS data of branch angles are a valuable tool to quantify branch angles at larger scales. 展开更多
关键词 Branch angle Measurement methods Quantitative structure models LAPLACIAN Semantic-laplacian Terrestrial laser scanning
在线阅读 下载PDF
Super-resolving refractive index measurements with even coherent-state sources and parity detection
10
作者 Qiang Wang Xiaohao Yang +1 位作者 Fu Song Lili Hao 《Chinese Physics B》 2025年第12期260-267,共8页
High-precision refractive index measurement has become a research hotspot in recent years.However,traditional refractive index measurement often adopts intensity detection,whose performance is restricted by the classi... High-precision refractive index measurement has become a research hotspot in recent years.However,traditional refractive index measurement often adopts intensity detection,whose performance is restricted by the classical detection limit and is thus hard to improve further.In order to break through this limitation,we propose a quantum-enhanced refractive index sensing scheme utilizing even-coherent-state sources in combination with parity detection.In this paper,we analyze the detection performance of the proposed system.Due to the inevitable photon loss in practical applications,the effects of photon loss on resolution and sensitivity are also investigated.Numerical results show that the resolution of the proposed strategy breaks through the Rayleigh limit and achieves super-resolving refractive index measurement.Relative to existing coherent-state schemes,our strategy leads to a twofold resolution improvement.Furthermore,the physical origins of the super-resolution are analyzed. 展开更多
关键词 refractive index measurement even coherent state parity photon counting DETECTION SUPER-RESOLUTION
原文传递
Rigid and stable nitroxide spin label for high-resolution distance measurements on proteins by DEER experiments
11
作者 Ya-Ting Chen Xing Zhang +4 位作者 Jia-Liang Chen Bin-Bin Pan Daniella Goldfarb Yin Yang Xun-Cheng Su 《Magnetic Resonance Letters》 2025年第3期81-88,共8页
The distance distributions between two site-specifically anchored spin labels in a protein,measured by pulsed electron-electron double resonance(PELDOR or DEER),provide rich sources of structural and conformational re... The distance distributions between two site-specifically anchored spin labels in a protein,measured by pulsed electron-electron double resonance(PELDOR or DEER),provide rich sources of structural and conformational restraints on the proteins or their complexes.The rigid connection of the nitroxide spin label to the protein improves the accuracy and precision of distance measurement.We report a new spin labelling approach by formation of thioester bond between nitroxide(NO)spin label,NOAI(NO spin labels activated by acetylimidazole),and a protein thiol,and this spin labeling method has demonstrated high performance in DEER distance measurement on proteins.The results showed that NOAI has shorter connection to the protein ligation site than 2,2,5,5-tetramethyl-pyrroline-1-oxyl methanethiosulfonate(MTSL)and 3-maleimido-proxyl(M-Prox)in the respective protein conjugate and produces narrower distance distributions for the tested proteins including ubiquitin(Ub),immunoglobulin-binding b1 domain of streptococcal protein G(GB1),and second mitochondria-derived activator of caspases(Smac).The NOAI protein conjugate connected by a thioester bond is resistant to reducing reagent and offers highfidelity DEER distance measurements in cell lysates. 展开更多
关键词 DEER NO spin label Distance measurement EPR Spin labeling of protein
在线阅读 下载PDF
Digital twin-based structural health monitoring and measurements of dynamic characteristics in balanced cantilever bridge
12
作者 Tidarut Jirawattanasomkul Le Hang +4 位作者 Supasit Srivaranun Suched Likitlersuang Pitcha Jongvivatsakul Wanchai Yodsudjai Punchet Thammarak 《Resilient Cities and Structures》 2025年第3期48-66,共19页
This study developed a digital twin(DT)and structural health monitoring(SHM)system for a balanced cantilever bridge,utilizing advanced measurement techniques to enhance accuracy.Vibration and dynamic strain measuremen... This study developed a digital twin(DT)and structural health monitoring(SHM)system for a balanced cantilever bridge,utilizing advanced measurement techniques to enhance accuracy.Vibration and dynamic strain measurements were obtained using accelerometers and piezo-resistive strain gauges,capturing low-magnitude dynamic strains during operational vibrations.3D-LiDAR scanning and Ultrasonic Pulse Velocity(UPV)tests captured the bridge's as-is geometry and modulus of elasticity.The resulting detailed 3D point cloud model revealed the structure's true state and highlighted discrepancies between the as-designed and as-built conditions.Dynamic properties,including modal frequencies and shapes,were extracted from the strain and acceleration measurements,providing critical insights into the bridge's structural behavior.The neutral axis depth,indicating stress distribution and potential damage,was accurately determined.Good agreement between vibration measurement data and the as-is model results validated the reliability of the digital twin model.Dynamic strain patterns and neutral axis parameters showed strong correlation with model predictions,serving as sensitive indicators of local damage.The baseline digital twin model and measurement results establish a foundation for future bridge inspections and investigations.This study demonstrates the effectiveness of combining digital twin technology with field measurements for real-time monitoring and predictive maintenance,ensuring the sustainability and safety of the bridge infrastructure,thereby enhancing its overall resilience to operational and environmental stressors. 展开更多
关键词 Digital twin Structural health monitoring Balanced cantilever bridge 3D-LiDAR Dynamic strain measurement
在线阅读 下载PDF
Precision storage lifetime measurements of highly charged heavy ions in the CSRe storage ring using a Schottky resonator
13
作者 Qian Wang Xin-Liang Yan +13 位作者 Guang-Yu Zhu Shahab Sanjari Li-Jun Mao He Zhao Yuri ALitvinov Rui-Jiu Chen Meng Wang Yu-Hu Zhang You-Jin Yuan Jun-Xia Wu Hong-Yang Jiao Yue Yu Zu-Yi Chen Yin-Fang Luo 《Nuclear Science and Techniques》 2025年第1期150-160,共11页
Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of S... Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of Schottky noise detectors,the number of stored ions in the ring is determined by the peak area in the measured revolution frequency spectrum.Because of their intrinsic amplitude-frequency characteristic(AFC),Schottky detector systems exhibit varying sensitivities at different frequencies.Using low-energy electron-cooled stored ions,a new method is developed to calibrate the AFC curve of the Schottky detector system of the Experimental Cooler Storage Ring(CSRe)storage ring located in Lanzhou,China.Using the amplitude-calibrated frequency spectrum,a notable refinement was observed in the precision of both the peak position and peak area.As a result,the storage lifetimes of the electron-cooled fully ionized^(56)Fe^(26+)ions were determined with high precision at beam energies of 13.7 and 116.4 MeV/u,despite of frequency drifts during the experiment.When electron cooling was turned off,the effective vacuum condition experienced by the 116.4 MeV/u^(56)Fe^(26+)ions was determined using amplitude-calibrated spectra,revealing a value of 2×10^(−10)mbar,which is consistent with vacuum gauge readings along the CSRe ring.The method reported herein will be adapted for the next-generation storage ring of the HIAF facility under construction in Huizhou,China.It can also be adapted to other storage ring facilities worldwide to improve precision and enhance lifetime measurements using many ions in the ring. 展开更多
关键词 Lifetime measurement Schottky mass spectrometry Sensitivity response Highly charged heavy ion RESONATOR UH vacuum Nondestructive diagnostics
在线阅读 下载PDF
Micro-Gal level gravity measurements with cold atom interferometry 被引量:9
14
作者 周敏康 段小春 +3 位作者 陈乐乐 罗覃 徐耀耀 胡忠坤 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第5期32-43,共12页
Developments of the micro-Gal level gravimeter based on atom interferometry are reviewed, and the recent progress and results of our group are also presented. Atom interferometric gravimeters have shown high resolutio... Developments of the micro-Gal level gravimeter based on atom interferometry are reviewed, and the recent progress and results of our group are also presented. Atom interferometric gravimeters have shown high resolution and accuracy for gravity measurements. This kind of quantum sensor has excited world-wide interest for both practical applications and fundamental research. 展开更多
关键词 gravity measurements atom interferometer laser cooling and trapping precision measurements
原文传递
Liver stiffness measurements in patients with metabolic dysfunction-associated steatotic liver disease:Updates on the method effectiveness and perspectives
15
作者 Olga Sukocheva Tsai-Wing Ow +2 位作者 Damian Harding Marc Le Mire Edmund Tse 《World Journal of Hepatology》 2025年第7期30-44,共15页
Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most widespread chronic liver disease signified by serious life-threatening conditions.The prevalence of MASLD increases along the growing prevalen... Metabolic dysfunction-associated steatotic liver disease(MASLD)is the most widespread chronic liver disease signified by serious life-threatening conditions.The prevalence of MASLD increases along the growing prevalence in obesity and metabolic syndrome.To minimize costs and complications,non-invasive diagnostic tools,including transient elastography(TE),were introduced for assessment of MASLD.TE measures liver stiffness(LS),a clinical marker for the diagnosis of liver fibrosis and cirrhosis.LS measurements are based on ultrasound wave imaging and quantification.Vibration-controlled TE,including FibroScan®,is commonly used TE methods which can accurately identify the degree of liver fibrosis and cirrhosis progression.TE was reported to predict the progression towards hepatocellular carcinoma,portal hypertension,and varices.However,the accuracy of LS diagnostics alone in patients with MASLD remains controversial.TE measurements have several limitations,including inadequate precision due to focal liver lesions,cholestasis,inflammation,and other pathological and anatomical factors which can lead to the stiffness variability.Overestimations of TE readings were reported in obese patients with body mass index(BMI)over 30 kg/m2,and older patients with ascites,diabetes,or hypertension.Not all MASLD patients have high BMI.The prevalence of obesity among MASLD patients varies worldwide,indicating the urgent need for comprehensive diagnostic tools.In patients with MASLD,improved diagnostic accuracy has been demonstrated by combining LS measurements with other blood test-based scores and simple clinical parameters(agile scores based on age,sex,platelet count,aminotransferases,and diabetes).This study reviews the limitations of TE-based diagnostics and discusses the combined scoring algorithm.In conclusion,the sequence of LS measurements along assessment of other important clinical markers is an effective,low-cost,reliable tool to identify and monitor fibrosis progression in MASLD. 展开更多
关键词 Non-alcoholic fatty liver disease Liver fibrosis Metabolic syndrome Metabolic dysfunction-associated steatotic liver disease Liver stiffness measurement Transient elastography
暂未订购
New laser spectroscopy measurements challenge modern nuclear theories
16
作者 Yang Sun 《Nuclear Science and Techniques》 2025年第12期1-3,共3页
When discussing atomic nuclei,deformation is one of the most common topics.However,when we connect the concept of shape with high-precision experimental measurements,sometimes the explanation may not be as simple as w... When discussing atomic nuclei,deformation is one of the most common topics.However,when we connect the concept of shape with high-precision experimental measurements,sometimes the explanation may not be as simple as we think.A recent measurement of nuclear charge radii(Phys.Rev.Lett.134,182501(2025))challenges current nuclear ab initio models. 展开更多
关键词 nuclear ab initio models nuclear charge radii measurement nuclear charge radii physrevlett challenges atomic nuclei laser spectroscopy atomic nucleideformation deformation
在线阅读 下载PDF
Detecting high-dimensional multipartite entanglement via some classes of measurements 被引量:1
17
作者 刘璐 高亭 闫凤利 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第2期249-254,共6页
Mutually unbiased bases, mutually unbiased measurements and general symmetric informationally complete measure- ments are three related concepts in quantum information theory. We investigate multipartite systems using... Mutually unbiased bases, mutually unbiased measurements and general symmetric informationally complete measure- ments are three related concepts in quantum information theory. We investigate multipartite systems using these notions and present some criteria detecting entanglement of arbitrary high dimensional multi-qudit systems and multipartite sys- tems of subsystems with different dimensions. It is proved that these criteria can detect the k-nonseparability (k is even) of multipartite qudit systems and arbitrary high dimensional multipartite systems of m subsystems with different dimensions. We show that they are more efficient and wider of application range than the previous ones. They provide experimental implementation in detecting entanglement without full quantum state tomography. 展开更多
关键词 detection of entanglement multipartite quantum states mutually unbiased bases mutually unbi-ased measurements general symmetric informationally complete measurements
原文传递
Anthropometric Breast Measurements: Analysis of the Average Breast in the Mexican Female Population 被引量:1
18
作者 David Flores-Soto Jose C. Martinez-López +7 位作者 Fernando Barbosa-Villarreal Fernando I. Recio-Espana Jaime A. García-Espinoza Alfredo Chama-Naranjo Ana P. Campollo-Lopez D. Deluna-Gallardo Alejandro Costa-Dulche Cuahutemoc Márquez-Espriella 《Journal of Biosciences and Medicines》 2022年第3期124-135,共12页
Introduction: The elements and perception of beauty vary between populations around the world. To obtain better results, surgical techniques should be planned based on anthropometric characteristics of the race, locat... Introduction: The elements and perception of beauty vary between populations around the world. To obtain better results, surgical techniques should be planned based on anthropometric characteristics of the race, location, and body mass index (BMI). Objectives: To determine which are the standard measurements and anatomical proportions of the breast in a healthy Mexican women population. Materials and Methods: Female Mexican volunteers between 20 and 60 years of age, without any history of breast illness or breast surgery were studied. Demographic information and standard breast anthropometric measurements were collected manually by one of the authors. For the statistical analysis a Student-T test was performed, and the Pearson correlation coefficient was obtained using the latest version of SPSS software. Results: 78 volunteers were included in the analysis. Mean height, weight and BMI were 1.6 m, 68.9 Kg, and 26.6 Kg/m2 respectively. The mean anthropometric values found were: Supra Sternal notch to nipple distance (SSN:N) 22 cm, Breast volume (BV) 372.6 cm3, Upper breast pole length (UBPL) 11 cm, Lower Breast Pole length (LBPL) 7.7 cm, Midline to Nipple distance (ML:N) 10.2 cm, Transverse diameter of the Nipple areola complex (NAC-T) 4.1 cm, Height of the Nipple Areola Complex (NAC-H) 4.1 cm, Base of the breast (BB) 13.4 cm, Upper Pole to Lower Pole Ratio (UPP:LPP) 58.9:41.1. A statistically significant difference between Right and left breast was not found. The UPP/ LPP ratio in our population is far different from what is considered internationally aesthetic (45:55). A positive correlation was found between weight/ BMI and SSN:N, BV, BB, ML:N and LBPL. Also between age and SSN:N, LBPL, BV and BB. Conclusion: This study sets the Anthropometric grounds in Mexican population for an objective individual patient analysis and comparison with the female population of this and other nations. 展开更多
关键词 Average Breast Anthropometric measurements Mexico Breast Anthropometric measurements Mexico
暂未订购
Average coherence with respect to complementary measurements
19
作者 Bin Chen Shao-Ming Fei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2021年第1期35-39,共5页
We investigate the average coherence with respect to a complete set of complementary measurements.By using a Wigner-Yanase skew information-based coherence measure introduced in Luo and Sun(2017 Phys.Rev.A 96,022130),... We investigate the average coherence with respect to a complete set of complementary measurements.By using a Wigner-Yanase skew information-based coherence measure introduced in Luo and Sun(2017 Phys.Rev.A 96,022130),we evaluate the average coherence of a state with respect to any complete set of mutually unbiased measurements and general symmetric informationally complete measurements,respectively.We also establish analytically the relations among these average coherences. 展开更多
关键词 average coherence mutually unbiased measurements general symmetric informationally complete measurements
原文传递
Emulation of Realistic Multi-Path Propagation Channels inside an Anechoic Chamber for Antenna Diversity Measurements
20
作者 Alaa Choumane Ahmad El Sayed Ahmad Khaled Khoder 《Wireless Engineering and Technology》 2020年第1期1-12,共12页
As antennas are inherently included recommended in Over-The-Air (OTA) testing, it is important to also consider realistic channel models for the multiple-input multiple-output (MIMO) device performance evaluation. Thi... As antennas are inherently included recommended in Over-The-Air (OTA) testing, it is important to also consider realistic channel models for the multiple-input multiple-output (MIMO) device performance evaluation. This paper aims to emulate realistic multi-Path propagation channels in terms of angles of arrivals (AoA) and cross-polarization ratio (XPR) with Rayleigh fading, inside an anechoic chamber, for antenna diversity measurements. In this purpose, a practical multi-probe anechoic chamber measurement system (MPAC) with 24 probe antennas (SATIMO SG24) has been used. However, the actual configuration of this system is not able to reproduce realistic channels. Therefore, a new method based on the control of the SG24 probes has been developed. At first time, this method has been validated numerically through the comparison of simulated and analytical AoA probability density distributions. At the second time, the performance of an antenna diversity system inside the SG24 has been performed in terms of the correlation coefficient and diversity gain (DG) using an antenna reference system. Simulated and measurements results have shown a good agreement. 展开更多
关键词 Channel Emulation Multi-Path OTA measurements Antenna Diversity measurements MIMO Correlation Coefficient Diversity Gain
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部