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Predictive Ability of Hypertriglyceridemic Waist,Hypertriglyceridemic Waist-to-Height Ratio,and Waist-to-Hip Ratio for Cardiometabolic Risk Factors Clustering Screening among Chinese Children and Adolescents
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作者 XIAO Tian Li YUAN Shu Qian +6 位作者 GAO Jing Yu Julien SBaker YANG Yi De WANG Xi Jie ZHENG Chan Juan DONG Yan Hui ZOU Zhi Yong 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第3期233-241,共9页
Objective Hypertriglyceridemic waist(HW),hypertriglyceridemic waist-to-height ratio(HWHtR),and waist-to-hip ratio(WHR)have been shown to be indicators of cardiometabolic risk factors.However,it is not clear which indi... Objective Hypertriglyceridemic waist(HW),hypertriglyceridemic waist-to-height ratio(HWHtR),and waist-to-hip ratio(WHR)have been shown to be indicators of cardiometabolic risk factors.However,it is not clear which indicator is more suitable for children and adolescents.We aimed to investigate the relationship between HW,HWHtR,WHR,and cardiovascular risk factors clustering to determine the best screening tools for cardiometabolic risk in children and adolescents.Methods This was a national cross-sectional study.Anthropometric and biochemical variables were assessed in approximately 70,000 participants aged 6–18 years from seven provinces in China.Demographics,physical activity,dietary intake,and family history of chronic diseases were obtained through questionnaires.ANOVA,χ2 and logistic regression analysis was conducted.Results A significant sex difference was observed for HWHtR and WHR,but not for HW phenotype.The risk of cardiometabolic health risk factor clustering with HW phenotype or the HWHtR phenotype was significantly higher than that with the non-HW or non-HWHtR phenotypes among children and adolescents(HW:OR=12.22,95%CI:9.54-15.67;HWHtR:OR=9.70,95%CI:6.93-13.58).Compared with the HW and HWHtR phenotypes,the association between risk of cardiometabolic health risk factors(CHRF)clustering and high WHR was much weaker and not significant(WHR:OR=1.14,95%CI:0.97-1.34).Conclusion Compared with HWHtR and WHR,the HW phenotype is a more convenient indicator with higher applicability to screen children and adolescents for cardiovascular risk factors. 展开更多
关键词 Hypertriglyceridemic waist waist-to-hip ratio Children and adolescents China Hypertriglyceridemic waist-to-height ratio Cardiovascular risk factors
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An Experimental and Numerical Thermal Flow Analysis in a Solar Air Collector with Different Delta Wing Height Ratios
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作者 Ghobad Shafiei Sabet Ali Sari +3 位作者 Ahmad Fakhari Nasrin Afsarimanesh Dominic Organ Seyed Mehran Hoseini 《Frontiers in Heat and Mass Transfer》 EI 2024年第2期491-509,共19页
This study conducts both numerical and empirical assessments of thermal transfer and fluid flow characteristics in a Solar Air Collector(SAC)using a Delta Wing Vortex Generator(DWVG),and the effects of different heigh... This study conducts both numerical and empirical assessments of thermal transfer and fluid flow characteristics in a Solar Air Collector(SAC)using a Delta Wing Vortex Generator(DWVG),and the effects of different height ratios(Rh=0.6,0.8,1,1.2 and 1.4)in delta wing vortex generators,which were not considered in the earlier studies,are investigated.Energy and exergy analyses are performed to gain maximum efficiency.The Reynolds number based on the outlet velocity and hydraulic diameter falls between 4400 and 22000,corresponding to the volume flow rate of 5.21–26.07 m^(3)/h.It is observed that the delta wing vortex generators with a higher height ratio yield maximum heat transfer enhancement and overall enhancement ratio.The empirical and numerical findings demonstrate that the exergy and thermal efficiencies decline in a specific range.TheNusselt number,pressure drop,energy,and exergy efficiencies enhance with rising Reynolds number,although the friction coefficient diminishes.The maximum heat transfer enhancement is 57%.According to the evaluation of exergy efficiency,the greatest efficiency of 31.2%is obtained at Rh=1.4 and Reynolds number 22000. 展开更多
关键词 Vortex generators heat transfer augmentation numerical simulation solar air collector empirical height ratio
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Dynamics and Wheel's Slip Ratio of a Wheel-legged Robot in Wheeled Motion Considering the Change of Height 被引量:13
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作者 DING Xilun LI Kejia XU Kun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第5期1060-1067,共8页
The existing research on dynamics and slip ratio of wheeled mobile robot (WMR) are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the... The existing research on dynamics and slip ratio of wheeled mobile robot (WMR) are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS- Ⅱ. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS- Ⅱ in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified, Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height. 展开更多
关键词 wheel-legged robot DYNAMICS slip ratio change of height nonholonomic constraints
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Stress-strain-acoustic responses in failure process of coal rock with different height to diameter ratios under uniaxial compression 被引量:11
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作者 GUO Yu-xia ZHAO Yong-hui +3 位作者 WANG Sheng-wei FENG Guo-rui ZHANG Yu-jiang RAN Hong-yu 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第6期1724-1736,共13页
Residual coal pillars play an important role in mining the adjacent coal seam safely,managing the gobs and maintaining the stability of abandoned coal mines.The height to diameter ratio(H/D)affects the stability of re... Residual coal pillars play an important role in mining the adjacent coal seam safely,managing the gobs and maintaining the stability of abandoned coal mines.The height to diameter ratio(H/D)affects the stability of residual coal pillars.In this study,uniaxial compressive tests of coal specimens with five H/D(2.0,1.5,1.0,0.8 and 0.6)were performed,and the stress,strain and acoustic emission(AE)were monitored.Results show that the uniaxial compressive strength(UCS)and peak strain increase with H/D decreasing.An empirical equation is proposed to calculate the UCS based on the H/D.The AE activities during coal failure process can be separated into four periods.The span of quiet period and rapid decline period shorten with H/D decreasing.The smaller the H/D is,the more complicated the failure characteristics of coal will be.The failure form of coal with H/D of 2.0,1.5,and 1.0 is primarily shear failure,while splitting failure along the axial direction is the mainly mode when H/D is 0.8 or 0.6.The initiation,expansion,aggregation and connection of micro-cracks can be reflected by the real-time spatial evolution of AE event points. 展开更多
关键词 residual coal pillar height to diameter ratio uniaxial compression acoustic emission micro-crack evolution
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Effects of Different Sowing Times on Plant Height, Leaf Stem Ratio and DW/FW Ratio of Forage Sorghum in Autumn Idle Land 被引量:5
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作者 ZHOU Han-zhang LIU Huan +4 位作者 JIA Hai-yan ZHOU Xin-jian WEI Zhi-min LI Shun-guo LIU Hai-zhong 《Agricultural Science & Technology》 CAS 2018年第2期57-66,共10页
The aim was to explore the linear regression prediction models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. [Method] The relationships between sowing tim... The aim was to explore the linear regression prediction models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. [Method] The relationships between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were simulated and compared by employing field plot experiment and linear regression analysis. [Result] The sowing time had a great impact on plant height, leaf stem ratio and DW/FW ratio of forage sorghum in autumn idle land. With the delay of sowing time, the plant height and DW/FW ratio of forage sorghum decreased, while the leaf stem ratio increased. The regression models between sowing time and plant height, leaf stem ratio and DW/FW ratio of forage sorghum were established: plant height and sowing time, yheight = 234.725- 5.005X; leaf stem ratio and sowing time,ylcaf= 0.096 + 0,019x; DW/FW ratio and sowing time, ydry= 0.305-0.002X. From July 23rd to August 30th, the plant height of forage sorghum was reduced by 5.005 cm, the leaf stem ratio was increased by 0.019 and the DW/FW ratio was reduced by 0.002 in average when hhe sowing time was delayed by one day. [Conclusion] This study provides a theoretical support for the production of forage sorghum in autumn idle land. 展开更多
关键词 Autumn idle land Forage sorghum Sowing time Plant height Leaf stem ratio DW/FW ratio
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Research on the squeeze cast technology of the castings with large ratio of height to thickness 被引量:1
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作者 LI Chen-xi SAN Jing-chao +3 位作者 XU Na CAO Liang BAI Yan-hua LI Rong-de 《China Foundry》 SCIE CAS 2005年第4期264-267,共4页
The squeeze cast technology is only applicable, at present, to the castings with a ratio of height to thickness less than 3.5. Researching the squeeze cast technology for castings with a large ratio of height to thick... The squeeze cast technology is only applicable, at present, to the castings with a ratio of height to thickness less than 3.5. Researching the squeeze cast technology for castings with a large ratio of height to thickness will broaden the applicable range of the advanced casting technology. This paper describes a study of the temperature distribution during solidification for castings with a ratio of height to thickness of 7 by the methods of experiment and computer simulation. The shrinkage porosity distribution in the castings and the mechanical properties of the castings were also researched. The experimental and simulated results show that increasing squeeze force, or enhancing mold temperature, cannot reduce the shrinkage porosities in the castings. When castings solidify in a sequential manner and the squeeze force effectively acts on the surface of the liquid metal, the shrinkage porosities in the castings are eliminated and mechanical properties are clearly improved. 展开更多
关键词 SQUEEZE CAST CASTINGS with LARGE ratio of height to thickness sequence solidification SHRINKAGE porosity
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Rational cutting height for large cutting height fully mechanized top-coal caving 被引量:7
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作者 Huang Bingxiang Li Hongtao +2 位作者 Liu Changyou Xing Shijun Xue Weichao 《Mining Science and Technology》 EI CAS 2011年第3期457-462,共6页
Large cutting height fully mechanized top-coal caving is a new mining method that improves recovery ratio and single-pass production. It also allows safe and efficient mining. A rational cutting height is one key para... Large cutting height fully mechanized top-coal caving is a new mining method that improves recovery ratio and single-pass production. It also allows safe and efficient mining. A rational cutting height is one key parameter of this technique. Numerical simulation and a granular-media model experiment were used to analyze the effect of cutting height on the rock pressure of a fully mechanized top-coal caving work face. The recovery ratio was also studied. As the cutting height increases the top-coal thickness is reduced. Changing the ratio of cutting to drawing height intensifies the face pressure and the top-coal shattering. A maximum cutting height exists under a given set of conditions due to issues with surrounding rock-mass control. An increase in cutting height makes the top-coal cave better and the recovery ratio when drawing top-coal is then improved. A method of adjusting the face rock pressure is presented. Changing the cutting to drawing height ratio is the technique used to control face rock pressure. The recovery ratio when cutting coal exceeds that when caving top-coal so the face recovery ratio may be improved by over sizing the cutting height and increasing the top-coal drawing ratio. An optimum ratio of cutting to drawing height exists that maximizes the face recovery ratio. A rational cutting height is determined by comprehensively considering the surrounding rock-mass control and the recovery ratio. At the same time increasing the cutting height can improve single pass mining during fully mechanized top-coal caving. 展开更多
关键词 Large cutting height fully mechanizedmining with sublevel caving Cutting heightThe ratio of cutting height to drawing heightGround pressureRecovery ratio
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Change of the mode of failure by interface friction and width-to-height ratio of coal specimens 被引量:3
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作者 Gamal Rashed Syd S.Peng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第3期256-265,共10页
Bumps in coal mines have been recognized as a major hazard for many years. These sudden and violent failures around mine openings have compromised safety, ventilation and access to mine workings.Previous studies showe... Bumps in coal mines have been recognized as a major hazard for many years. These sudden and violent failures around mine openings have compromised safety, ventilation and access to mine workings.Previous studies showed that the violence of coal specimen failure depends on both the interface friction and width-to-height(W/H) ratio of coal specimen. The mode of failure for a uniaxially loaded coal specimen or a coal pillar is a combination of both shear failure along the interface and compressive failure in the coal. The shear failure along the interface triggered the compressive failure in coal. The compressive failure of a coal specimen or a coal pillar can be controlled by changing its W/H ratio. As the W/H ratio increases, the ultimate strength increases. Hence, with a proper combination of interface friction and the W/H ratio of pillar or coal specimen, the mode of failure will change from sudden violent failure which is brittle failure to non-violent failure which is ductile failure. The main objective of this paper is to determine at what W/H ratio and interface friction the mode of failure changes from violent to non-violent. In this research, coal specimens of W/H ratio ranging from 1 to 10 were uniaxially tested under two interface frictions of 0.1 and 0.25, and the results are presented and discussed. 展开更多
关键词 Bump Burst Coal strength Violent failure Width-to-height(W/H) ratio Interface friction Stressestrain curve
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Finite element analysis on the collapse of infill walls with holes and different length-to-height ratios
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作者 周晓方 叶燕华 +1 位作者 SUN Rui YIN Wan-qing 《Journal of Chongqing University》 CAS 2013年第4期155-162,共8页
Wenchuan earthquake damage survey displayed the major structures of buildings suffered only small damages,but it was common that infill walls suffered heavy damages or even collapse. To study the failure forms and col... Wenchuan earthquake damage survey displayed the major structures of buildings suffered only small damages,but it was common that infill walls suffered heavy damages or even collapse. To study the failure forms and collapse mechanism of infill walls in an earthquake,the influence of opening or length-to-height ratio on shake-resisting capability of filling walls was analyzed,and measures to improve the anti-collapse ability of infill walls were put forwaed. The numerical simulations on collapse process in earthquake were carried out by using ABAQUS software. We used 5 single story and single span models. It is revealed that the rigidity and compressive capacity of infill walls are reduced because of the infill walls with holes and the increases of length-to-height ratios. Adding constructional columns and horizontal beams can ensure structural integrity and improve the anti-collapse ability of the wall. 展开更多
关键词 finite element analysis COLLAPSE length-height ratio RIGIDITY
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Analysis of Ankle-Brachial Index, Waist-Hip Ratio, Ejection-Fraction, Obesity, Smoking, Alcohol Habits, Diabetes and Hypertension as Independent Predictors of Complexity and Severity of Coronary Artery Disease
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作者 Naveen Kumar Cheruku Adikesava Naidu Otikunta +1 位作者 Y. V. Subba Reddy Ravi Srinivas 《International Journal of Clinical Medicine》 2015年第11期838-844,共7页
Background: The present study was conducted to examine the association between various coronary risk factors and clinical parameters, with special emphasis on ankle-brachial index, in predicting the severity and compl... Background: The present study was conducted to examine the association between various coronary risk factors and clinical parameters, with special emphasis on ankle-brachial index, in predicting the severity and complexity of coronary artery disease. Methods: Patients diagnosed with coronary artery disease at our hospital between September-2012 and December-2014 were examined in this study. Selected patients were screened for cardiovascular risk factors including diabetes, hypertension, smoking, and alcohol habits as well as for clinical parameters including body-mass index, waist-hip ratio, ankle-brachial index, and ejection fraction. All patients underwent coronary angiography and were evaluated for severity of coronary artery disease (based on number of vessels involved) and complexity of coronary angiographic lesions (measured by computer-assisted Syntax score calculator). The collected data were analyzed to determine the role of cardiovascular risk factors and clinical parameters as predictors of complexity and severity of coronary artery disease. Results: A total of 211 patients (mean age: 54.64 ± 9.9 years;81% males) with coronary artery disease were analyzed. Findings revealed that diabetes mellitus (p < 0.001), hypertension (p < 0.001), smoking habits (p = 0.036), and low ankle-brachial index (p < 0.001) were independent predictors of complex coronary artery disease as measured by Syntax score. Significant associations were also evident between severity of coronary artery disease and diabetes mellitus (p < 0.001), hypertension (p < 0.001), and ankle-brachial index (p < 0.001). Conversely, other cardiovascular risk factors including body-mass index, alcohol habits, wait-hip ratio, and ejection fraction did not exhibit significant associations with severity and complexity of coronary artery. Conclusions: The early diagnosis of coronary artery can be predicated by evaluating diabetes, hypertension, and smoking habits in patients presenting with acute coronary syndrome. In addition, ankle-brachial index can be used as an effective non-invasive bed-side tool, as an alternative to Syntax score, in predicting the severity and complexity of coronary artery disease. 展开更多
关键词 Ankle-Brachial Index Cardiovascular Risk Factors Coronary Artery DISEASE Peripheral Arterial DISEASE Predictor Syntax Score waist-Hip ratio
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Performance of waist circumference relative to BMI in predicting risk of obesity and hypertension among affluent Indian adults 被引量:2
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作者 Shobha Rao Prajakta Parab-Waingankar 《Health》 2013年第8期16-22,共7页
In view of the fact that Asians have higher abdominal fat at lower levels of body mass index (BMI), measures of abdominal adiposity such as waist circumference (WC) and waist to hip ratio (WHR) were investigated as pr... In view of the fact that Asians have higher abdominal fat at lower levels of body mass index (BMI), measures of abdominal adiposity such as waist circumference (WC) and waist to hip ratio (WHR) were investigated as predictors of hypertension. Data on BMI, WC, WHR and blood pressure (BP) were recorded through a cross-sectional study on 419 urban adults (210 men and 209 women;aged 30-60 years) in Pune, India. Abdominal obesity was higher among women than men (35.9% vs. 32.4%). However, age adjusted mean systolic BP (124.3 ± 15.1 mmHg vs. 114.7 ± 17.2 mmHg), diastolic BP (82.9 ± 10.5 mmHg vs. 76.4 ± 10.7 mmHg) and prevalence of hypertension (34.3% vs. 21.5%) was significantly higher (p < 0.01) among men than among women. Although both WC and WHR increased with increase in BMI, correlation coefficient of BMI with WC was significantly (p < 0.01) higher than that with WHR in both sexes, suggesting that WC could be better for assessing adiposity. In men, odds ratio [OR (95% CI) = 2.19 (1.08-4.45)] for hypertension was significant (p < 0.05) only for those in highest tertile of WC while it was significant (p < 0.01) even in the middle tertile in case of women [8.24 (2.67-25.43) for higher and 5.71 (1.82-17.89) for middle tertile]. Optimal cutoff for identifying obesity and hypertension showed significant (p < 0.01) area under curve (AUC) and sensitivity for WC than WHR in both sexes. The risk cutoffs were lower compared to those proposed by the World Health Organization especially for men, but were comparable with reported Asian studies. Thus, it was evident that WC performed better than BMI and WHR for assessing the risk of hypertension and may be used as a simple, convenient and inexpensive screening tool in epidemiological studies. 展开更多
关键词 ABDOMINAL ADIPOSITY Asians Blood Pressure Body Mass Index waist CIRCUMFERENCE waist to HIP ratio
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INFLUENCE OF PHASE RATIO ON PACKING EFFICIENCY IN COLUMNS FOR MASS TRANSFER PROCESSES 被引量:1
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作者 Reinhard Billet Michael Schultes 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 1997年第2期25-34,共10页
The phase ratio has been found to affect the packing efficiency in packed columns.To ac-count for the effect,a model is set up to correlate the height of a mass transfer unit with the phaseratio with reasonable accura... The phase ratio has been found to affect the packing efficiency in packed columns.To ac-count for the effect,a model is set up to correlate the height of a mass transfer unit with the phaseratio with reasonable accuracy.Proposed also is a correlation that allows to predict the efficiency inquestion at any given liquid-gas ratio using the knowledge of other efficiency values at other liquid-gas ratios. 展开更多
关键词 phase ratio height of a TRANSFER unit PACKINGS
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Robust Solution for Boundary Layer Height Detections with Coherent Doppler Wind Lidar 被引量:1
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作者 Lu WANG Wei QIANG +3 位作者 Haiyun XIA Tianwen WEI Jinlong YUAN Pu JIANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第11期1920-1928,共9页
Although coherent Doppler wind lidar(CDWL)is promising in detecting boundary layer height(BLH),differences between BLH results are observed when different CDWL measurements are used as tracers.Here,a robust solution f... Although coherent Doppler wind lidar(CDWL)is promising in detecting boundary layer height(BLH),differences between BLH results are observed when different CDWL measurements are used as tracers.Here,a robust solution for BLH detections with CDWL is proposed and demonstrated:mixed layer height(MLH)is retrieved best from turbulent kinetic energy dissipation rate(TKEDR),while stable boundary layer height(SBLH)and residual layer height(RLH)can be retrieved from carrier-to-noise ratio(CNR).To study the cause of the BLH differences,an intercomparison experiment is designed with two identical CDWLs,where only one is equipped with a stability control subsystem.During the experiment,it is found that the CNR could be distorted by instrument instability because the coupling efficiency from free-space to the polarization-maintaining fiber of the telescope is sensitive to the surrounding environment.In the ML,a bias up to 2.13 km of the MLH from CNR is found,which is caused by the CNR deviation.In contrast,the MLH from TKEDR is robust as long as the accuracy of wind is guaranteed.In the SBL(RL),the CNR is found capable to retrieve SBLH and RLH simultaneously and robustly.This solution is tested during an observation period over one month.Statistical analysis shows that the root-mean-square errors(RMSE)in the MLH,SBLH,and RLH are 0.28 km,0.23 km,and 0.24 km,respectively. 展开更多
关键词 boundary layer height coherent Doppler wind lidar carrier-to-noise ratio turbulent kinetic energy dissipation rate
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A new strategy for ionospheric remote sensing using the 130.4/135.6 nm airglow intensity ratios 被引量:2
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作者 XiaoHan Yin JianQi Qin Larry J.Paxton 《Earth and Planetary Physics》 CAS CSCD 2023年第4期445-459,共15页
We demonstrate here that global-scale determination of a key ionospheric parameter,the peak height of the F_(2)region(h_(m)F_(2)),can be obtained by making a simple ratio measurement of the atomic oxygen 130.4 and 135... We demonstrate here that global-scale determination of a key ionospheric parameter,the peak height of the F_(2)region(h_(m)F_(2)),can be obtained by making a simple ratio measurement of the atomic oxygen 130.4 and 135.6 nm emissions in the far-ultraviolet nightglow with a nadir-viewing system such as a pair of photometers suitable for flight on a CubeSat.We further demonstrate that measurements from an altitude that is within the typical range of nighttime h_(m)F_(2)250−450 km can provide the ratios that are needed for retrieval of the h_(m)F_(2).Our study is conducted mostly through numerical simulations by using radiative transfer models of the two emissions coupled with empirical models of the atmosphere and ionosphere.Modeling results show that the relationship between the h_(m)F_(2)and the intensity ratio is sensitive to the altitude from which the emissions are observed,primarily because of the distinctly different degrees of resonant scattering of the two emissions in the atmosphere.A roughly quadratic relationship can be established for observations from an orbit of~400 km,which enables h_(m)F_(2)retrieval.Parametric analysis indicates that the relationship can be affected by the ambient atmospheric conditions through resonant scattering and O2 absorption.For typical nighttime conditions with h_(m)F_(2)250−450 km,retrieval of the h_(m)F_(2)from synthetic observations shows that the typical errors are only a few kilometers(up to~20 km),depending on the accuracy of the ambient conditions predicted by the empirical models.Our findings pave the way for use of the 130.4/135.6 nm intensity ratios for global-scale monitoring of the nighttime ionosphere at mid to low latitudes. 展开更多
关键词 nighttime ionosphere far-ultraviolet remote sensing 130.4/135.6 nm airglow intensity ratio peak height of the F_(2)region(h_(m)F_(2)) TIMED observation
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The Carpal Height Ratio for The Trinidadian Population: What is Normal?
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作者 Amanda Partap Ian James Persad Ryan Raghunanan 《Open Journal of Orthopedics》 2024年第11期453-460,共8页
Aim: To determine the normal carpal height ratio for the Trinidadian population. Design & method: A retrospective review of wrist radiographs performed during the period January 2022 to June 2022 at San Fernando G... Aim: To determine the normal carpal height ratio for the Trinidadian population. Design & method: A retrospective review of wrist radiographs performed during the period January 2022 to June 2022 at San Fernando General Hospital was conducted. A total of 200 radiographs were independently reviewed by two blinded assessors utilizing the PACS system. The carpal height ratio (CHR) and revised carpal height (RCH) ratio was calculated using two methods. A p-value Results: The radiographs reviewed consisted of 94 female and 106 male patients with an age range of 19 to 86 years. The mean CHR was 0.473 and the revised CHR 1.469. The ratio for carpal height as well as the revised CHR was observed to vary amongst the different age groups studied. The CHR and revised CHR for the population was observed to vary based on gender with gender significantly influencing the CHR value (p = 0.001). Conclusions: The CHR of the Trinidadian population as calculated by the data collected falls below the average CHR documented worldwide. However, the interpretation of this value is based on the baseline reference ratio for a population. Therefore, according to our average CHR for our population previous comparison of a CHR index to international figures would have led to erroneous interpretation of results. A decrease in CHR is indicative of carpal collapse. The comparison of CHR to the established normal CHR for the population is believed to allow for early detection of carpal collapse. 展开更多
关键词 Carpal Collapse Carpal height ratio Wrist Degenerative Disease Wrist Pathology Carpal Bone Disease
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Height Detection and Analysis of Water Flowing Fractured Zone of Coal Face
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作者 Ziyang Feng 《Computational Water, Energy, and Environmental Engineering》 2021年第4期131-139,共9页
Taking 91105 working face as the research object, the observation method of water flowing fracture<span style="font-family:Verdana;">d</span><span style="font-family:Verdana;"> zo... Taking 91105 working face as the research object, the observation method of water flowing fracture<span style="font-family:Verdana;">d</span><span style="font-family:Verdana;"> zone and the layout of mining holes were determined by analyzing the field geological structure</span><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">It was shown that the fractured zone height and the ratio given by the measured method were 52.33 and 12.46, respectively. By the numerical simulation method with the software of UDEC, the fractured zone height and the ratio were 42.5 and 10.12. By comparison of measured height data and UDEC numerical simulation, there were some differences between the measured height and the calculated results of UDEC numerical simulation method. The method of simulation can be used as the technical basis for the design of waterproof coal pillar in the future.</span> 展开更多
关键词 Water Flowing Fractured Zone height Detection Fracture Mining ratio Numerical Simulation
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老年高血压人群腰围身高比与新发脑梗死的关系
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作者 郭晓斌 刘苹 于文霞 《实用医学杂志》 CAS 北大核心 2024年第11期1592-1596,共5页
目的研究腰围身高比(WHtR)与老年人新发脑梗死的相关性。方法纳入开滦地区研究人群9096例老年高血压患者,以首次发生脑梗死为终点事件,采取前瞻性队列研究方法进行研究,依据观察对象WHtR值以0.05为间距等距分为四组,分别为G1组(WHtR<... 目的研究腰围身高比(WHtR)与老年人新发脑梗死的相关性。方法纳入开滦地区研究人群9096例老年高血压患者,以首次发生脑梗死为终点事件,采取前瞻性队列研究方法进行研究,依据观察对象WHtR值以0.05为间距等距分为四组,分别为G1组(WHtR<0.45)、G2组(0.45≤WHtR<0.50)、G3组(0.50≤WHtR<0.55)及G4组(WHtR≥0.55),用寿命表方法统计各人群的累积终点事件发生率,采用Cox比例风险分析方法,探讨WHtR在新发脑梗死中的作用。模型一为单一因子Cox比例风险分析模式,只考察WHtR对脑梗死发生风险的作用;在此基础上,模型二为校正性别、年龄、体重及血清超敏C反应蛋白、收缩压、血清甘油三酯、抽烟史、血清空腹血糖、饮酒情况、高密度脂蛋白胆固醇、舒张压、体育运动、低密度脂蛋白胆固醇、文化程度、服降压药史后观察WHtR对新发脑梗死的作用。结果随访时间为(9.3±2.7)年,期间共新发脑梗死848例。以G2组为对照,单因素Cox比例风险回归模型分析显示G1组、G3组和G4各组发生脑梗死的HR(95%CI)分别为1.00(0.67~1.50)、1.29(1.05~1.60)、1.36(1.12~1.66);多因素Cox比例风险回归模型分析显示G1组、G3组和G4各组发生脑梗死的HR(95%CI)分别为1.09(0.72~1.65)、1.24(0.99~1.54)、1.31(1.05~1.62)。结论老年高血压人群当0.45≤WHtR<0.50时脑卒中发病风险最低,WHtR≥0.55与新发脑梗死风险增加相关。 展开更多
关键词 腰围身高比 脑梗死 老年高血压 队列研究
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体重指数、腰臀比及胰岛素抵抗与绝经后子宫内膜息肉发病的相关性分析 被引量:1
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作者 张娟 周生碧 +1 位作者 彭丽霞 郑云迎 《中国性科学》 2024年第2期97-100,共4页
目的探究体重指数(BMI)、腰臀比(WHR)及胰岛素抵抗(IR)与绝经后子宫内膜息肉(EP)发病的相关性。方法选取2021年10月至2023年1月资阳市人民医院收治的180例怀疑为绝经后EP患者作为研究对象。根据病理检查结果将其分为EP组(n=90)和非EP组(... 目的探究体重指数(BMI)、腰臀比(WHR)及胰岛素抵抗(IR)与绝经后子宫内膜息肉(EP)发病的相关性。方法选取2021年10月至2023年1月资阳市人民医院收治的180例怀疑为绝经后EP患者作为研究对象。根据病理检查结果将其分为EP组(n=90)和非EP组(n=90)。比较两组的BMI、WHR、IR发生情况、性激素水平,分析BMI、WHR及IR与绝经后EP发病的关系。结果EP组的BMI、腰围、臀围、WHR均高于对照组(P<0.05);EP组空腹血糖(FBG)、空腹胰岛素(FIN)、稳态模型胰岛素抵抗指数(HOMA-IR)水平及IR发生率均高于非EP组(P<0.05);两组黄体生成素(LH)、卵泡刺激素(FSH)、雌二醇(E_(2))、孕酮(P)水平比较,差异无统计学意义(P>0.05);EP患者BMI、WHR与HOMA-IR均呈正相关(P<0.05);BMI、WHR、HOMA-IR是EP发生的独立危险因素。结论BMI、WHR、HOMA-IR与绝经后EP发生均具有相关性,临床需重视肥胖、胰岛素水平过高患者,定期进行妇科检查。 展开更多
关键词 体重指数 腰臀比 胰岛素抵抗 绝经 子宫内膜息肉
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Effects of geometric configuration on droplet generation in Y-junctions and anti-Y-junctions microchannels
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作者 Zhao-Miao Liu Li-Kun Liu Feng Shen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第5期741-749,共9页
Droplets generation in Y-junctions and anti-Yjunctions microchannels are experimentally studied using a high speed digital microscopic system and numerical simulation.Geometric configuration of a microchannel,such as ... Droplets generation in Y-junctions and anti-Yjunctions microchannels are experimentally studied using a high speed digital microscopic system and numerical simulation.Geometric configuration of a microchannel,such as Y-angle(90°,135°,-90° and-135°),channel depth and other factors have been taken into consideration.It is found that droplets generated in anti-Y-junctions have a smaller size and a shorter generation cycle compared with those in Yjunctions under the same experimental conditions.Through observing the internal velocity field,the vortex appearing in continuous phase in anti-Y-junctions is one of the key factors for the difference of droplet size and generation cycle.It is found that droplet size is bigger and generation cycle is longer when the absolute angle value of the intersection between the continuous and the dispersed phases(i.e.,the angle between the main channel and the continuous phase or the dispersed phase channel) increases.The droplet's size is influenced by the Y-angle,which varies with the channel depth in Y-junctions.The Y-angle has a positive effect on the droplet generation cycle,but a smaller height-width ratio will enhance the impact of a continuous and dispersed phase's intersection angle on the droplet generation cycle in Y-junctions microchannels. 展开更多
关键词 MICROFLUIDICS Y-junctions and anti-Yjunctions microchannels Y-angle height-width ratio in cross section
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Multi-objective Optimization of a Two-Stage Helical Gearbox to Improve Efficiency and Reduce Height
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作者 Tran Quoc Hung Truong Thi Thu Huong 《Journal of Environmental Science and Engineering(B)》 2023年第5期236-247,共12页
The goal of this research is to look at multi-target optimization of a two-stage helical gearbox in order to determine the best key design elements for reducing gearbox height and enhancing gearbox efficiency.To do th... The goal of this research is to look at multi-target optimization of a two-stage helical gearbox in order to determine the best key design elements for reducing gearbox height and enhancing gearbox efficiency.To do this,the method known as Taguchi and GRA(Grey Relation Analysis)were used in two stages to address the problem.The single-objective optimization problem was addressed first to close the gap between variable levels,and then the multi-objective optimization problem was solved to determine the best primary design variables.The first and second stage CWFWs(Coefficients of Wheel Face Width),ACS(Permissible Contact Stresses),and first stage gear ratio were also calculated.The study’s findings were utilized to identify the best values for five critical design aspects of a two-stage helical gearbox. 展开更多
关键词 Helical gearbox multi-objective optimization gear ratio gearbox height gearbox efficiency.
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