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Fine mapping of two recessive genes TaFLA1 and TaSPL8 controlling flag leaf angle in bread wheat
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作者 Qiushi Wang Jiaxing Bai +11 位作者 Hongchun Xiong Yongdun Xie Chaojie Wang Jiayu Gu Linshu Zhao Huiyuan Li Jinfeng Zhang Shirong Zhao Yuping Ding Zhengwu Fang Huijun Guo Luxiang Liu 《The Crop Journal》 SCIE CSCD 2024年第4期1159-1167,共9页
Flag leaf angle is one of the key target traits in high yield wheat breeding.A smaller flag leaf angle reduces shading and enables plants to grow at a higher density,which increases yield.Here we identified a mutant,j... Flag leaf angle is one of the key target traits in high yield wheat breeding.A smaller flag leaf angle reduces shading and enables plants to grow at a higher density,which increases yield.Here we identified a mutant,je0407,with an 84.34%-89.35%smaller flag leaf angle compared with the wild type.The mutant also had an abnormal lamina joint and no ligule or auricle.Genetic analysis indicated that the ligule was controlled by two recessive genes,which were mapped to chromosomes 2AS and 2DL.The mutant allele on chromosome 2AS was named Tafla1b,and it was fine mapped to a 1 Mb physical interval.The mutant allele on chr.2DL was identified as Taspl8b,a novel allele of TaSPL8 with a missense mutation in the second exon,which was used to develop a cleaved amplified polymorphic sequence marker.F3 and F4 lines derived from crosses between Jing411 and je0407 were genotyped to investigate interactions between the Tafla1b and Taspl8b alleles.Plants with the Tafla1b/Taspl8a genotype had 58.41%-82.76%smaller flag leaf angles,6.4%-24.9%shorter spikes,and a greater spikelet density(0.382 more spikelets per cm)compared with the wild type.Plants with the Tafla1a/Taspl8b genotype had 52.62%-82.24%smaller flag leaf angles and no differences in plant height or spikelet density compared with the wild type.Tafla1b/Taspl8b plants produced erect leaves with an abnormal lamina joint.The two alleles had dosage effects on ligule formation and flag leaf angle,but no significant effect on thousand-grain weight.The mutant alleles provide novel resources for improvement of wheat plant architecture. 展开更多
关键词 WHEAT Ligule Flag leaf angle Fine mapping Tafla1 Taspl8
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Tilt Angle Optimality Criteria for Stand Alone PV Systems
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作者 Mohammad Abu-Naser 《Journal of Power and Energy Engineering》 2024年第3期1-18,共18页
The conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy avai... The conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy availability varies, this criterion may not be optimal. This study explores two alternative optimization criteria focused on maximizing baseload supply potential and minimizing required storage capacity to address seasonality in energy generation. The optimal tilt angles determined for these criteria differed significantly from the standard approach. This research highlights additional factors crucial for designing solar power systems beyond gross energy generation, essential for the global transition towards a fully renewable energy-based electric grid in the future. 展开更多
关键词 Electric Grid Fixed Solar Panels Optimal PV tilt angle Seasonal Solar Variability Renewable Energy Supply-Demand Balance
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Modified particle swarm optimization-based antenna tilt angle adjusting scheme for LTE coverage optimization 被引量:5
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作者 潘如君 蒋慧琳 +3 位作者 裴氏莺 李沛 潘志文 刘楠 《Journal of Southeast University(English Edition)》 EI CAS 2015年第4期443-449,共7页
In order to solve the challenging coverage problem that the long term evolution( LTE) networks are facing, a coverage optimization scheme by adjusting the antenna tilt angle( ATA) of evolved Node B( e NB) is pro... In order to solve the challenging coverage problem that the long term evolution( LTE) networks are facing, a coverage optimization scheme by adjusting the antenna tilt angle( ATA) of evolved Node B( e NB) is proposed based on the modified particle swarm optimization( MPSO) algorithm.The number of mobile stations( MSs) served by e NBs, which is obtained based on the reference signal received power(RSRP) measured from the MS, is used as the metric for coverage optimization, and the coverage problem is optimized by maximizing the number of served MSs. In the MPSO algorithm, a swarm of particles known as the set of ATAs is available; the fitness function is defined as the total number of the served MSs; and the evolution velocity corresponds to the ATAs adjustment scale for each iteration cycle. Simulation results showthat compared with the fixed ATA, the number of served MSs by e NBs is significantly increased by 7. 2%, the quality of the received signal is considerably improved by 20 d Bm, and, particularly, the system throughput is also effectively increased by 55 Mbit / s. 展开更多
关键词 long term evolution(LTE) networks antenna tilt angle coverage optimization modified particle swarm optimization algorithm
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Optimum Tilt Angle of Flow Guide in Steam Turbine Exhaust Hood Considering the Effect of Last Stage Flow Field 被引量:4
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作者 Lihua CAO Aqiang LIN +1 位作者 Yong LI Bin XIAO 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第4期866-875,共10页
Abstract Heat transfer and vacuum in condenser are influenced by the aerodynamic performance of steam tur- bine exhaust hood. The current research on exhaust hood is mainly focused on analyzing flow loss and optimal d... Abstract Heat transfer and vacuum in condenser are influenced by the aerodynamic performance of steam tur- bine exhaust hood. The current research on exhaust hood is mainly focused on analyzing flow loss and optimal design of its structure without consideration of the wet steam condensing flow and the exhaust hood coupled with the front and rear parts. To better understand the aerodynamic performance influenced by the tilt angle of flow guide inside a diffuser, taking a 600 MW steam turbine as an example, a numerical simulator CFX is adopted to solve compressible three-dimensional (3D) Reynolds time-aver- aged N-S equations and standard k-e turbulence model. And the exhaust hood flow field influenced by different tilt angles of flow guide is investigated with consideration of the wet steam condensing flow and the exhaust hood coupled with the last stage blades and the condenser throat. The result shows that the total pressure loss coefficient and the static pressure recovery coefficient of exhaust hood change regularly and monotonously with the gradual increase of tilt angle of flow guide. When the tilt angle of flow guide is within the range of 30~ to 40~, the static pressure recovery coefficient is in the range of 15.27% to 17.03% and the total pressure loss coefficient drops to approximately 51%, the aerodynamic performance of exhaust hood is significantly improved. And the effectiveenthalpy drop in steam turbine increases by 0.228% to 0.274%. It is feasible to obtain a reasonable title angle of flow guide by the method of coupling the last stage and the condenser throat to exhaust hood in combination of the wet steam model, which provides a practical guidance to flow guide transformation and optimal design in exhaust hood. 展开更多
关键词 Steam turbine Exhaust hood Last stageblades tilt angle of flow guide Aerodynamicperformance
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Effect of tool tilt angle on strength and microstructural characteristics of friction stir welded lap joints of AA2014-T6 aluminum alloy 被引量:3
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作者 C.RAJENDRAN K.SRINIVASAN +2 位作者 V.BALASUBRAMANIAN H.BALAJI P.SELVARAJ 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第9期1824-1835,共12页
Friction stir welding(FSW)has been extensively adopted to fabricate aluminium alloy joints by incorporating various welding parameters that include welding speed,rotational speed,diameters of shoulder and pin and tool... Friction stir welding(FSW)has been extensively adopted to fabricate aluminium alloy joints by incorporating various welding parameters that include welding speed,rotational speed,diameters of shoulder and pin and tool tilt angle.FSW parameters significantly affect the weld strength.Tool tilt angle is one of the significant process parameters among the weld parameters.The present study focused on the effect of tool tilt angle on strength of friction stir lap welding of AA2014-T6 aluminium alloy.The tool tilt angle was varied between 0°and 4°with an equal increment of 1°.Other process parameters were kept constant.Macrostructure and microstructure analysis,microhardness measurement,scanning electron micrograph,transmission electron micrograph and energy dispersive spectroscopy analysis were performed to evaluate the lap shear strength of friction stir lap welded joint.Results proved that,defect-free weld joint was obtained while using a tool tilt angle of 1°to 3°.However,sound joints were welded using a tool tilt angle of 2°,which had the maximum lap shear strength of 14.42 kN and microhardness of HV 132.The joints welded using tool tilt angles of 1°and 3°yielded inferior lap shear strength due to unbalanced material flow in the weld region during FSW. 展开更多
关键词 AA2014 aluminium alloy friction stir lap welding tool tilt angle lap shear strength microstructure
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Optimum Tilt Angles for Photovoltaic Panels during Winter Months in the Vaal Triangle, South Africa 被引量:3
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作者 Osamede Asowata James Swart Christo Pienaar 《Smart Grid and Renewable Energy》 2012年第2期119-125,共7页
Optimizing the output power of a photovoltaic panel improves the efficiency of a solar driven energy system. The maximum output power of a photovoltaic panel depends on atmospheric conditions, such as (direct solar ra... Optimizing the output power of a photovoltaic panel improves the efficiency of a solar driven energy system. The maximum output power of a photovoltaic panel depends on atmospheric conditions, such as (direct solar radiation, air pollution and cloud movements), load profile and the tilt and orientation angles. This paper describes an experimental analysis of maximizing output power of a photovoltaic panel, based on the use of existing equations of tilt angles derived from mathematical models and simulation packages. Power regulation is achieved by the use of a DC-DC converter, a fixed load resistance and a single photovoltaic panel. A data logger is used to make repeated measurements which ensure reliability of the results. The results of the paper were taken over a four month period from April through July. The photovoltaic panel was set to an orientation angle of 0? with tilt angles of 16?, 26? and 36?. Preliminary results indicate that tilt angles between 26? and 36? provide optimum photovoltaic output power for winter months in South Africa. 展开更多
关键词 Solar Energy OPTIMUM Orientation angle tilt angle Data Logger Photovoltaic (PV) Panel
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Influence of Tilted Angle on Effective Linear Energy Transfer in Single Event Effect Tests for Integrated Circuits at 130 nm Technology Node 被引量:2
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作者 张乐情 卢健 +5 位作者 胥佳灵 刘小年 戴丽华 徐依然 毕大炜 张正选 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第11期119-122,共4页
A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transf... A heavy-ion irradiation experiment is studied in digital storage cells with different design approaches in 130?nm CMOS bulk Si and silicon-on-insulator (SOI) technologies. The effectiveness of linear energy transfer (LET) with a tilted ion beam at the 130?nm technology node is obtained. Tests of tilted angles θ=0 ° , 30 ° and 60 ° with respect to the normal direction are performed under heavy-ion Kr with certain power whose LET is about 40?MeVcm 2 /mg at normal incidence. Error numbers in D flip-flop chains are used to determine their upset sensitivity at different incidence angles. It is indicated that the effective LETs for SOI and bulk Si are not exactly in inverse proportion to cosθ , furthermore the effective LET for SOI is more closely in inverse proportion to cosθ compared to bulk Si, which are also the well known behavior. It is interesting that, if we design the sample in the dual interlocked storage cell approach, the effective LET in bulk Si will look like inversely proportional to cosθ very well, which is also specifically explained. 展开更多
关键词 SOI Influence of tilted angle on Effective Linear Energy Transfer in Single Event Effect Tests for Integrated Circuits at 130 nm Tec
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Combination of Tilt-Angle and Euler Deconvolution Approaches to Determine Structural Features from Aeromagnetic Data Modeling over Akonolinga-Loum Area (Centre-East, Cameroon) 被引量:1
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作者 Justine Yandjimain Théophile Ndougsa-Mbarga +5 位作者 Arsène Meying Marcelin Bikoro Bi-Alou Paul Claude Ngoumou Stéphane Patrick Assembe Jean Daniel Ngoh Olivier Ulrich Igor Owono-Amougou 《International Journal of Geosciences》 2017年第7期925-947,共23页
Aeromagnetic data for center-east Cameroon between the latitudes 3.5° to 4.5°N and longitudes 12° to 12.5°E are used to further study the subsurface area of this part of the geological Province of ... Aeromagnetic data for center-east Cameroon between the latitudes 3.5° to 4.5°N and longitudes 12° to 12.5°E are used to further study the subsurface area of this part of the geological Province of Central Africa and the Congo Craton. The GIS and GEOSOFT v6.5 softwares are used to treat the data. This analysis enabled us to explore our study area from surface right to the base. The Tilt Angle method is used to delineate geological structures and to estimate the depth. The Euler’s deconvolution method is used to estimate the specific depth of structural contacts. We estimate the northern boundary of the Congo Craton and southern boundary of the Pan-African starting from 3°7'N of West to 3°75'N of East. Its depth is estimated around 2.6 km for deep and 0.1 km for shallow while the direction is WSW-ENE and the NW slope varies from 30° to 60°. We obtain that main and minor lineaments exist throughout, from the surface to the base of the area with their principal direction being SW-NE. We also obtain the vertical gradient contact and the quasihorizontal contact. This is proof of the subduction of the Pan-African belt under the Congo Craton due to the intense collision which caused the rejuvenation of the crust. The main consequence of this collision is the formation of pudding and fold structures, beginning from the superficial part right to the base and which caused the intrusion of schistose, chlorite-schist, quartzite in the micaschist and the intrusions of gneiss and garnetiferous schist in the migmatite. In our study, we highlight the presence of 37 major and 523 minor lineaments that localize the circulation of minerals. The probable slope of the lineaments in the northern part of the region varies from 30° to 60° in a SE direction while in the southern part, and it varies from 30° to 60° in a NW direction. 展开更多
关键词 tilt-angle EULER DECONVOLUTION LINEAMENTS Fault Gradient Akonolinga-Loum
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Combination of structure tensor and tilt angle in the edge detection of potential field data
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作者 LIN Song LI Lili SHI Jianan 《Global Geology》 2018年第4期252-259,共8页
Edge detection is a commonly requested task in the interpretation of potential field data. Different methods have different results for varied depths and shapes of geological bodies. In this paper,we propose using the... Edge detection is a commonly requested task in the interpretation of potential field data. Different methods have different results for varied depths and shapes of geological bodies. In this paper,we propose using the combination of structure tensor and tilt angle to detect the edges of the sources,which can display the edges of shallow and deep bodies simultaneously. Through tests on synthetic potential field data,it is obvious that the proposed edge detection methods can display the sources edges more clearly and precisely,compared with other commonly used methods. The application on real potential field data shows similar result,obtaining the edges of layers and faults clearly. In addition,another advantage of the new method is its insensitivity to noise. 展开更多
关键词 COMBINATION structure TENSOR tilt angle EDGE DETECTION potential field data
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Optimum Design of Tilt Angle and Horizontal Direction of Solar Collectors under Obstacle’s Shadow for Building Applications
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作者 Shaoning Wang Bo Hong 《Journal of Building Construction and Planning Research》 2015年第2期60-67,共8页
Solar collectors can provide clean, renewable, and domestic energy. The tilt angle and horizontal direction of solar collectors significantly affect its efficiency. There are many good methods to search the optimum ti... Solar collectors can provide clean, renewable, and domestic energy. The tilt angle and horizontal direction of solar collectors significantly affect its efficiency. There are many good methods to search the optimum tilt angle and horizontal direction to realize the maximum total radiation on the solar collector within a particular day or a specific period. However, it is hard to realize it when solar collectors are placed under obstacle’s shadows;especially when some obstacles, such as trees, have irregular shapes. This paper presents algorithms to achieve the best tilt angle and horizontal direction for solar collector’s performance under the free-form surfaces 3D obstacle’s shadow. The solution process is composed of 4 steps. First, it creates a 3D scene, in which a unique color is given to the solar collector. Second, it employs orthographic projection from the point of view to get an image of the scene. Third, the number of pixels is used to represent the efficiency of the solar collector by counting the pixels of the unique color. Fourth, the efficiency of solar collector in each direction in a period of time is calculated with many images to further select the best direction. 展开更多
关键词 SOLAR COLLECTOR tilt angle HORIZONTAL Direction SOLAR Radiation Optimum Design Orthographic PROJECTION
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The Disagreement between Anisotropic-Isotropic Diffuse Solar Radiation Models as a Function of Solar Declination: Computing the Optimum Tilt Angle of Solar Panels in the Area of Southern-Italy
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作者 Emanuele Calabrò 《Smart Grid and Renewable Energy》 2012年第4期253-259,共7页
In this paper a simulation to maximize the global solar radiation on a sloped collecting surface was applied to typical latitudes in the area of southern Italy, to calculate the optimum tilt angle of solar panels on b... In this paper a simulation to maximize the global solar radiation on a sloped collecting surface was applied to typical latitudes in the area of southern Italy, to calculate the optimum tilt angle of solar panels on building structures or large photovoltaic power plants located in that geographical area. Indeed, the area of southern Italy and in particular Sicily and Calabria are the top of European locations for acquiring solar energy. Some models of diffuse solar irradiance were taken into account to determine panels inclinations that maximized the impinging solar radiation by means of global horizontal solar radiation data provided from the Italian Institute of ENEA (Italy). An algorithm was used for the simulation providing a set of tilt angles for each latitude. The optimum tilt angle values obtained from the simulation resulted to be strictly related to the model of diffuse solar radiation that was used. Indeed, the disagreement between the values obtained using anisotropic models of diffuse solar radiation and those obtained from the isotropic model resulted to decrease significantly with increasing solar declination, showing that the isotropic model can be reliable only in summer months. 展开更多
关键词 Global SOLAR Radiation DIFFUSE SOLAR Irradiance ISOTROPIC Model Optimum tilt angle SOLAR Panel
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Study on Seasonal Adjustment of Solar PV Tilt Angle around the North of 45th Parallel
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作者 Erdene Adiyasuren Tsutomu Dei 《Journal of Energy and Power Engineering》 2019年第7期267-271,共5页
The tilt angle of the small scale existing solar power plants is 60 degree and it is 45 degree for the megawatts(MW)class solar power plant in Mongolia.However,the PV module which is installed with 45 degree accumulat... The tilt angle of the small scale existing solar power plants is 60 degree and it is 45 degree for the megawatts(MW)class solar power plant in Mongolia.However,the PV module which is installed with 45 degree accumulates lots of snow during the winter.Currently,all solar PV systems installed in Mongolia are fixed the direction and tilt angles.According to the previous research result,the tilt angle of those systems was not suitable for using especially in the winter.The PV module which is installed with 60 degree does not accumulates snow even during the autumn and spring.According to the National Aeronautics and Space Administration(NASA)solar radiation database,solar irradiance for equator facing is largest at 32-degree tilted angle during the summer,47-degree during the spring and autumn,at 62-degree during the winter.The results of this paper show,the tilt angle of the PV module should be adjusted at least twice a year.For instance,the tilt angle will be adjusted at the 32-degree from 15th March to 24th August,at the 62-degree from 25th August to 15th March.In this case,the annual total energy output will be increased up to 30%than present production. 展开更多
关键词 PV MODULE ARRAY tilt angle
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Design of a titl angle measurement system based on ADXL345 sensor 被引量:7
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作者 SU Yan-ping GONG Mao-fa AN Bin ZHANG Jian-yu ZHAO Xu-jie 《Journal of Measurement Science and Instrumentation》 CAS 2014年第2期19-22,共4页
The titl angle measurement system based on the ADXL345 of three-axis acceleration sensor is introduced, and the composition and working principle of the system are described. The MSP430F149 microcontroller of ultra-lo... The titl angle measurement system based on the ADXL345 of three-axis acceleration sensor is introduced, and the composition and working principle of the system are described. The MSP430F149 microcontroller of ultra-low power and high performance is adopted. Firstly, the voltage value which is proportional to the acceleration value is output by ADXL345 when the system is powered. Secondly, the voltage value is converted into the corresponding digital signal by AD converter of the sensor. Thirdly, the digital signal is transformed into the titl angle according to the arithmetic processing of the MSP430F149. Finally, the corresponding angle is displayed on the liquid crystal display (LCD) screen. Experimental results show that the design has high sensitivity and response speed compared with the conventional methods. It is suitable for practical engineering application because of simple structure, low cost and low power consumption. 展开更多
关键词 ADXL345 MSP430F149 tilt angle measurement liquid crystal display (LCD)
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Estimation of Solar Radiation on Horizontal and Tilted Surface over Bangladesh 被引量:2
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作者 Mohammad Ashraful Islam Md. Saiful Alam +1 位作者 Komol Kanta Sharker Sanjoy Kumar Nandi 《Computational Water, Energy, and Environmental Engineering》 2016年第2期54-69,共16页
To estimate the monthly averaged solar radiations (global, diffuse and direct solar radiation) on horizontal surface and tilted surface over 10 stations (districts) in Bangladesh, thirty years monthly averaged data of... To estimate the monthly averaged solar radiations (global, diffuse and direct solar radiation) on horizontal surface and tilted surface over 10 stations (districts) in Bangladesh, thirty years monthly averaged data of various meteorological parameters namely the monthly averaged value of maximum temperature, minimum temperature, humidity and sunshine hours were used in this study. Assessment of the solar resources for the solar based renewable energy technologies of Bangladesh may be based upon this kind of measured data analyzed study. This study tried to estimate the monthly averaged solar radiation by presenting data in table and graph and finally analyze through equations and descriptions. Correlation between the measurements of monthly averaged solar radiation and the meteorological parameters was given for the selected 10 stations in Bangladesh. In conclusion, we tried to make a comparison among solar radiation on horizontal surface, fixed 20.83<sup> ° </sup> (degree) optimal tilt angle and variable optimal tilt surface at Dhaka station. 展开更多
关键词 Solar Radiation Meteorological Parameters Inclination angle Conversion Factor Optimal tilt angle
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颈椎前路椎体次全切除减压融合钛笼倾斜角度与术后钛笼下沉的有限元分析 被引量:1
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作者 李智斐 杨尹 +3 位作者 陈华龙 梁钦秋 钟远鸣 张翼升 《中国组织工程研究》 CAS 北大核心 2024年第9期1313-1319,共7页
背景:颈椎前路椎体次全切除减压融合是治疗颈椎退行性疾病的常规手段,钛笼是椎体次全切后维持颈椎稳定的重要植入物,近几年临床发现,术后很多患者出现钛笼下沉等并发症,其原因存在很大争议。目的:探讨颈椎前路椎体次全切除减压融合钛笼... 背景:颈椎前路椎体次全切除减压融合是治疗颈椎退行性疾病的常规手段,钛笼是椎体次全切后维持颈椎稳定的重要植入物,近几年临床发现,术后很多患者出现钛笼下沉等并发症,其原因存在很大争议。目的:探讨颈椎前路椎体次全切除减压融合钛笼倾斜角度与术后钛笼下沉的内在生物力学关系。方法:通过正常人体颈椎CT图像建立C_(4)-C_(6)节段三维有限元模型,在三维模型中模拟颈椎前路C5椎体次全切除减压融合,并模拟置入不同倾斜角度的钛笼(-6°至-1°称之为负角度,即钛笼前缘短于钛笼后缘为负角度;1°-6°称之为正角度,即钛笼前缘长于钛笼后缘为正角度)。在C_(4)椎体上分别施加预载荷50,100和150 N的应力作用,记录钛笼与C_(4)下终板和C_(6)上终板各个接触点的应力值(钛网接触面的各7个应力接触点),并进行统计学分析。结果与结论:①钛笼倾斜角正角度组和负角度组分别在C_(4)椎体施加50,100和150 N应力下产生的数据经Mann-Whitn检验发现,差异均有显著性意义(P<0.05);钛笼倾斜角正角度组在50,100和150 N应力条件下,其离散系数均小于负角度组;②在C_(4)椎体施加50,100和150 N应力条件下,钛笼倾斜角正角度组内Wilcoxon符号秩检验发现当角度设为1°-5°时,差异无显著性意义(P>0.05);但当钛笼倾斜角设为6°时,差异有显著性意义(P<0.05);③在C_(4)椎体施加50,100和150 N应力条件下,钛笼倾斜角负角度组内Wilcoxon符号秩检验发现当倾斜角设为-1°至-6°时,差异无显著性意义(P>0.05);④提示矢状位上,钛笼倾斜角为正角度时比倾斜角为负角度时更加稳定,更加适合临床使用;钛笼倾斜角在1°-5°区间内表现相对稳定,当倾斜角为6°时则稳定性开始下降,容易出现术后钛笼下沉的并发症,临床上根据术中情况更适合选用倾斜角度在1°-5°的钛笼,以提高疗效。 展开更多
关键词 颈椎 颈椎前路椎体次全切除 钛笼倾斜角 有限元分析 生物力学
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不同前倾角度倾转旋翼噪声数值计算分析
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作者 袁明川 孙会迅 +2 位作者 李志彬 牛青峰 樊枫 《西北工业大学学报》 EI CAS CSCD 北大核心 2024年第2期205-213,共9页
基于自由尾迹结合FW-H(Ffowcs Williams-Hawkings)方程的方法建立了倾转旋翼气动噪声计算模型,并采用倾转旋翼模型噪声试验数据验证了计算分析方法的有效性。选取典型过渡路径,进行考虑配平的倾转双旋翼气动噪声特性计算,获得了旋翼桨... 基于自由尾迹结合FW-H(Ffowcs Williams-Hawkings)方程的方法建立了倾转旋翼气动噪声计算模型,并采用倾转旋翼模型噪声试验数据验证了计算分析方法的有效性。选取典型过渡路径,进行考虑配平的倾转双旋翼气动噪声特性计算,获得了旋翼桨叶剖面非定常气动载荷以及不同测点气动噪声等计算结果,分析了倾转旋翼在不同前倾角下噪声指向性和噪声声压级的变化。结果表明:由于双旋翼噪声在传播中的叠加和抵消,倾转双旋翼和孤立单旋翼的噪声指向特性存在较大的不同;倾转旋翼噪声随前倾角增加总体上呈现先增加后减小的变化趋势,在前倾角30°附近噪声最强;不同前倾角下噪声声压级和指向性的变化与旋翼桨尖马赫数、气动载荷和桨盘角度等多种因素相关。 展开更多
关键词 倾转旋翼 气动噪声 倾转角度 自由尾迹 FW-H方程
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智能倾角LED预警系统设计
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作者 姚铃丽 仲倩 +3 位作者 焦曹青 朱东驰 陈光良 张照锋 《电子器件》 CAS 2024年第4期897-902,共6页
提出了一种基于MCU与MEMS微机电惯性传感器技术的高精度倾角测量方法。系统以STM32F103微处理器为控制核心,采用三轴加速度和三轴角速度传感器作为倾角预警系统的主传感器,设计基于加速度和角速率陀螺的互补滤波器,提高倾角的测量精度,... 提出了一种基于MCU与MEMS微机电惯性传感器技术的高精度倾角测量方法。系统以STM32F103微处理器为控制核心,采用三轴加速度和三轴角速度传感器作为倾角预警系统的主传感器,设计基于加速度和角速率陀螺的互补滤波器,提高倾角的测量精度,并采用LED灯和蜂鸣器的报警实现大倾角的预警功能。实验表明,本系统倾角测量精度可达±0.1°,具有很好的工作稳定性和较高的性价比,可用于无人机、平衡车等应用场合。 展开更多
关键词 STM32处理器 倾角测量 预警系统 微机电
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基于耦合辐射模型的太阳能集热器倾角优化研究
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作者 王恩宇 王天生 +2 位作者 张学友 沈海笑 黄运兴 《可再生能源》 CAS CSCD 北大核心 2024年第7期894-900,共7页
为了使太阳能集热器获得更多的太阳辐射量,须对集热器倾角进行优化。文章在建立倾斜面太阳辐射计算模型的基础上,分别优化直接辐射、散射辐射的计算过程。以太阳能集热器运行期间倾斜面接收最大辐射量为求解目标,借助MATLAB对集热器倾... 为了使太阳能集热器获得更多的太阳辐射量,须对集热器倾角进行优化。文章在建立倾斜面太阳辐射计算模型的基础上,分别优化直接辐射、散射辐射的计算过程。以太阳能集热器运行期间倾斜面接收最大辐射量为求解目标,借助MATLAB对集热器倾角进行优化分析,得到月度最佳倾角和年度最佳倾角。其中天津地区的太阳能集热器年度最佳倾角为36.3°,比当地纬度略小;月度最佳倾角为10~64°,表现为夏季小冬季大的特点。相较于水平放置,在年度最佳倾角和月度最佳倾角下,太阳能集热器接收的年太阳辐射量可分别增加12.4%,17.3%;相较当地纬度作为倾角时,以月度最佳倾角值逐月调整接收的太阳辐射量可增加5.0%。分别以广州、拉萨、济南和长春为例,计算得到上述地区的年、月最佳倾角。对不同地区进行对比分析发现,直接辐射占比较高的地区逐月改变最佳倾角可获得更高的能量增益。 展开更多
关键词 太阳辐射模型 集热器 最佳倾角 设计优化
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排桩倾斜对双排桩支护结构性状影响分析
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作者 龚建伍 张森 谢亮 《建筑技术》 2024年第9期1044-1049,共6页
依托某双排桩基坑工程实践建立有限元模型,分析前、后排桩倾斜对基坑支护效果的影响,并与现场监测数据进行对比验证。研究结果表明:前排桩倾斜一定的角度,桩身弯矩和轴力增大,前排桩发挥斜撑作用,桩身水平位移及桩顶沉降减小,支护效果提... 依托某双排桩基坑工程实践建立有限元模型,分析前、后排桩倾斜对基坑支护效果的影响,并与现场监测数据进行对比验证。研究结果表明:前排桩倾斜一定的角度,桩身弯矩和轴力增大,前排桩发挥斜撑作用,桩身水平位移及桩顶沉降减小,支护效果提高;随着前排桩倾斜角度的增大,支护效果提升幅度减弱;后排桩倾斜可提高支护效果,不同倾斜角度下,桩身弯矩、轴力、水平位移和桩顶沉降变化幅度不同,但倾斜角度过大导致支护效果减弱;相同排桩倾斜角度下,前排桩倾斜对双排桩支护效果的提升显著优于后排桩倾斜,前排桩倾斜15°时支护效果最优。 展开更多
关键词 双排桩 倾斜角度 变形分析 有限元分析
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三杯风速传感器非水平风场测量性能 被引量:1
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作者 白赢策 刘昕 贺晓雷 《气象科技》 2024年第1期19-26,共8页
为解决三杯风速传感器在计量检定条件下与观测场景中环境差异所导致的测量数据误差,致力于研究空气流速计量标准在量值传递过程中的真实性、准确性和一致性,为新一代三杯风速传感器作为计量器具的新产品型式评价提供思路和参考指标,依... 为解决三杯风速传感器在计量检定条件下与观测场景中环境差异所导致的测量数据误差,致力于研究空气流速计量标准在量值传递过程中的真实性、准确性和一致性,为新一代三杯风速传感器作为计量器具的新产品型式评价提供思路和参考指标,依据杯式测风仪测量方法与自动气象站风速风向传感器检定规程,并在实验中加入了主体由角度编码器构成的自动化转盘系统,设计了三杯风速传感器在非水平风场内测量性能水平实验。通过调整三杯风速传感器在风洞试验段内的倾斜角度,模拟其在自然界非水平风场中的测量状态,同步采集风洞的标准指示风速、三杯风速传感器的实测风速以及其相应的倾斜角度,计算示值误差,利用方差分析、趋势分析、相关性分析和线性回归分析等统计方法,对不同倾斜角度下三杯风速传感器示值误差进行研究,得出了三杯风速传感器在风洞试验段内的示值误差与实测风速和倾斜角度之间的相关关系,提出了三杯风速传感器在非水平风场下的测量性能指标。研究了三杯风速传感器在非水平风场中实测风速与标准风速和倾斜角度的回归关系,提出了三杯风速传感器在计量环境下非水平风场中数据的量值传递修正算法。 展开更多
关键词 三杯风速传感器 非水平风场 倾斜角度 性能研究
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