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Tumour response following preoperative chemotherapy is affected by body mass index in patients with colorectal liver metastases
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作者 Hua-Chuan Song Hang-Cheng Zhou +10 位作者 Ping Gu Bing Bao Quan Sun Tian-Ming Mei Wei Cui Kang Yao Huan-Zhang Yao Shen-Yu Zhang Yong-Shuai Wang Rui-Peng Song Ji-Zhou Wang 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第2期331-342,共12页
BACKGROUND Colorectal cancer is the third most prevalent malignancy globally and ranks second in cancer-related mortality,with the liver being the primary organ of metastasis.Preoperative chemotherapy is widely recomm... BACKGROUND Colorectal cancer is the third most prevalent malignancy globally and ranks second in cancer-related mortality,with the liver being the primary organ of metastasis.Preoperative chemotherapy is widely recommended for initially or potentially resectable colorectal liver metastases(CRLMs).Tumour pathological response serves as the most important and intuitive indicator for assessing the efficacy of chemotherapy.However,the postoperative pathological results reveal that a considerable number of patients exhibit a poor response to preoperative chemotherapy.Body mass index(BMI)is one of the factors affecting the tumori-genesis and progression of colorectal cancer as well as prognosis after various antitumour therapies.Several studies have indicated that overweight and obese patients with metastatic colorectal cancer experience worse prognoses than those with normal weight,particularly when receiving first-line chemotherapy regimens in combination with bevacizumab.AIM To explore the predictive value of BMI regarding the pathologic response following preoperative chemotherapy for CRLMs.METHODS A retrospective analysis was performed in 126 consecutive patients with CRLM who underwent hepatectomy following preoperative chemotherapy at four different hospitals from October 2019 to July 2023.Univariate and multivariate logistic regression models were applied to analyse potential predictors of tumour pathological response.The Kaplan-Meier method with log rank test was used to compare progression-free survival(PFS)between patients with high and low BMI.BMI<24.0 kg/m^(2) was defined as low BMI,and tumour regression grade 1-2 was defined as complete tumour response.RESULTS Low BMI was observed in 74(58.7%)patients and complete tumour response was found in 27(21.4%)patients.The rate of complete tumour response was significantly higher in patients with low BMI(29.7%vs 9.6%,P=0.007).Multivariate analysis revealed that low BMI[odds ratio(OR)=4.56,95%confidence interval(CI):1.42-14.63,P=0.011],targeted therapy with bevacizumab(OR=3.02,95%CI:1.10-8.33,P=0.033),preoperative carcinoembryonic antigen level<10 ng/mL(OR=3.84,95%CI:1.19-12.44,P=0.025)and severe sinusoidal dilatation(OR=0.17,95%CI:0.03-0.90,P=0.037)were independent predictive factors for complete tumour response.The low BMI group exhibited a significantly longer median PFS than the high BMI group(10.7 mo vs 4.7 mo,P=0.011).CONCLUSION In CRLM patients receiving preoperative chemotherapy,a low BMI may be associated with better tumour response and longer PFS. 展开更多
关键词 Colorectal liver metastases body mass index Tumour regression grade Preoperative chemotherapy HEPATECTOMY
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Wingsuit Flying
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作者 颜丹(译) 《中学生英语》 2024年第22期21-21,共1页
Wingsuit Flying,alsocalled wingsuiting,is a variation of skydiving.In this sport,a person will fly in the air using a special jumpsuit called a wingsuit.This wingsuit comprises of two arm wings and a single leg wing w... Wingsuit Flying,alsocalled wingsuiting,is a variation of skydiving.In this sport,a person will fly in the air using a special jumpsuit called a wingsuit.This wingsuit comprises of two arm wings and a single leg wing which has inflatable nylon cells.The modern wingsuits were developed in the 1990's.They are sometimes referred to as birdman suits or flying squirrel suits. 展开更多
关键词 wings NYLON wing
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Wings-FDY一步法生产ITY的工艺研究
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作者 周龙 余锡攀 +2 位作者 李振宇 孙建杰 杜杨洋 《聚酯工业》 CAS 2024年第3期26-28,共3页
通过设备改造及工艺优化,成功实现了ITY在Wings-FDY设备上一步法生产。研究结果表明:风压设定为30 Pa,调整纺丝/卷绕上油比例为6:4,预热辊温度51℃,定型辊温度124℃,拉伸倍数3.2,卷绕速度3550 m/min时,ITY 148dtex/108f纺况稳定,物理指... 通过设备改造及工艺优化,成功实现了ITY在Wings-FDY设备上一步法生产。研究结果表明:风压设定为30 Pa,调整纺丝/卷绕上油比例为6:4,预热辊温度51℃,定型辊温度124℃,拉伸倍数3.2,卷绕速度3550 m/min时,ITY 148dtex/108f纺况稳定,物理指标均匀,满足客户定制化的产品需求。 展开更多
关键词 ITY wings-FDY 设备改造
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WingsFDY设备生产22dtex/24f细旦涤纶的工艺探讨
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作者 翟佳羽 袁礼栋 +2 位作者 李婧楠 苏宏新 赵毛毛 《合成纤维》 CAS 2024年第8期18-22,共5页
对22dtex/24f细旦涤纶全拉伸丝(FDY)生产中的熔体输送工艺、纺丝工艺、冷却工艺和牵伸定形等工艺进行了详细的分析与探讨。生产实践表明,该产品生产中采用的巴马格8辊WingsFDY设备具有高效节能、流程短的优势,能够有效降低FDY的生产成本... 对22dtex/24f细旦涤纶全拉伸丝(FDY)生产中的熔体输送工艺、纺丝工艺、冷却工艺和牵伸定形等工艺进行了详细的分析与探讨。生产实践表明,该产品生产中采用的巴马格8辊WingsFDY设备具有高效节能、流程短的优势,能够有效降低FDY的生产成本,对设备应用及新品种的开发具有一定的实践指导意义。 展开更多
关键词 细旦涤纶DTY 巴马格wingsFDY设备 工艺
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Critical Analysis of Children’s Drawings as a Diagnostic Tool for Body Schema and Body Image Disorder in Cerebral Palsy
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作者 Renée Lampe Ines Lützow +2 位作者 Tobias Blumenstein Varvara Turova Ana Alves-Pinto 《Neuroscience & Medicine》 2016年第4期133-148,共16页
Cerebral palsy is a multiple disability manifested by motor deficits and impairments of cognition, language, and body perception. To assess if body schema and body image distortion in children and youth with cerebral ... Cerebral palsy is a multiple disability manifested by motor deficits and impairments of cognition, language, and body perception. To assess if body schema and body image distortion in children and youth with cerebral palsy can be represented through draw-a-person-test, outcome measure of conscious and subconscious body awareness, visual perception and cognition in two age-matched groups, one with cerebral palsy and other with developmental disability, were collected. The outcome was compared within the two groups and with reference data (healthy population) and correlated with the outcome of draw-a-person test. Decreased scores in the draw-a-person test in subjects with cerebral palsy compared both to subjects with developmental disorders and to healthy population had strongly correlated with decreased scores in visual perception. This suggests that draw-a-person test may provide a preliminary guidance for the assessment of visual perception. No statistically significant effect of cognitive abilities on performance in the draw-a-person test was found. The influence of both conscious and subconscious body awareness on the scores in the draw-a-person test was not significant, which confirms that this test alone is not fully reliable to detect the body schema and body image disorder in cerebral palsy. 展开更多
关键词 Cerebral Palsy Draw-a-Person-Test body Perception body Representation Disorder
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Chyle leak following root of mesentery dissection in pancreaticoduodenectomy with inferior infracolic superior mesenteric artery first approach
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作者 Prabir Maharjan Sujan Regmee +5 位作者 Spandan D Adhikari Rabin Pahari Roshan Ghimire Dhiresh K Maharjan Suman K Shrestha Prabin B Thapa 《World Journal of Clinical Cases》 SCIE 2025年第8期8-14,共7页
BACKGROUND The root of mesentery dissection is one of the critical maneuvers,especially in borderline resectable pancreatic head cancer.Intra-abdominal chyle leak(CL)including chylous ascites may ensue in up to 10%of ... BACKGROUND The root of mesentery dissection is one of the critical maneuvers,especially in borderline resectable pancreatic head cancer.Intra-abdominal chyle leak(CL)including chylous ascites may ensue in up to 10%of patients after pancreatic resections.Globally recognized superior mesenteric artery(SMA)first approaches are invariably performed.The mesenteric dissection through the inferior infracolic approach has been discussed in this study emphasizing its post-operative impact on CL which is the cornerstone of this study.AIM To assess incidence,risk factors,clinical impact of CL following root of mesentery dissection,and the different treatment modalities.METHODS This is a retrospective study incorporating the patients who underwent dissection of the root of mesentery with inferior infracolic SMA first approach pancreat-oduodenectomy for the ventral body and uncinate mass of pancreas in the Department of Gastrointestinal and General Surgery of Kathmandu Medical College and Teaching Hospital from January 1,2021 to February 28,2024.Intraop-erative findings and postoperative outcomes were analyzed.RESULTS In three years,ten patients underwent root of mesentery dissection with inferior infracolic SMA first approach pancreatoduodenectomy.The mean age was 67.6 years with a male-to-female ratio of 4:5.CL was seen in four patients.With virtue of CL,Clavien-Dindo grade Ⅱ or higher morbidity was observed in four patients.Two patients had a hospital stay of more than 20 days with the former having a delayed gastric emptying and the latter with long-term total parenteral nutrition requirement.The mean operative time was 330 minutes.Curative resection was achieved in 100%of the patients.The mean duration of the intensive care unit and hospital stay were 2.55±1.45 days and 15.7±5.32 days,respectively.CONCLUSION Root of mesentery dissection with lymphadenectomy and vascular resection correlated with occurrence of CL.After complete curative resection,these were managed with total parenteral nutrition without adversely impacting outcome. 展开更多
关键词 Chyle leak Chylous ascites Clavien-Dindo Pancreatoduodenectomy Root of mesentery dissection Superior mesenteric artery first approach Total parenteral nutrition Uncinate mass Vascular resection Ventral body mass
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模糊WINGS视角下的ANP加权矩阵新构造方法 被引量:7
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作者 孙永河 李春好 +1 位作者 谢晖 段万春 《计算机工程与应用》 CSCD 2014年第12期26-32,37,共8页
构造因素集加权矩阵是ANP系统未加权超矩阵到加权超矩阵转化的一个关键技术。然而从已有的三种构造方法看,两两比较法比较机理混乱,而等权矩阵假设构造法通常是无效的,并且基于DEMATEL(决策试行与评价实验室)的构造方法不仅存在忽视因... 构造因素集加权矩阵是ANP系统未加权超矩阵到加权超矩阵转化的一个关键技术。然而从已有的三种构造方法看,两两比较法比较机理混乱,而等权矩阵假设构造法通常是无效的,并且基于DEMATEL(决策试行与评价实验室)的构造方法不仅存在忽视因素集自身强度的内在不足,而且也难以反映专家在对因素集之间影响关系判断时存在的"不精确性"。为克服上述缺陷,提出一种模糊WINGS(加权影响情景下的非线性测度体系)视角下的ANP因素集加权矩阵新构造方法。该方法一方面给出改进后的模糊DELPHI决策程序,充分考虑了专家判断过程中的"不精确性"。另一方面,系统提出模糊WINGS的方法思路,在系统因素集影响关系判别时充分考虑了因素集的自我影响强度,使因素集直接影响矩阵的构造更为合理。实例对比验证结果表明,该方法是科学合理的,有着较强的实践应用可操作性。 展开更多
关键词 模糊加权影响情景下的非线性测度体系(wings) 网络分析法 超矩阵 加权矩阵
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A Structured Mesh Euler and Interactive Boundary Layer Method for Wing/Body Configurations
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作者 李杰 周洲 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第1期19-27,共9页
To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a "semi-inverse" manner. ... To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a "semi-inverse" manner. For the turbulent boundary-layer, an integral method using Green's lag equation is coupled with the outer inviscid flow. A blowing velocity approach is used to simulate the displacement effects of the boundary layer. To predict the aerodynamic drag, it is developed a numerical technique called far-field method that is based on the momentum theorem, in which the total drag is divided into three component drags, i.e. viscous, induced and wave-formed. Consequently, it can provide more physical insight into the drag sources than the often-used surface integral technique. The drag decomposition can be achieved with help of the second law of thermodynamics, which implies that entropy increases and total pressure decreases only across shock wave along a streamline of an inviscid non-isentropic flow. This method has been applied to the DLR-F4 wing/body configuration showing results in good agreement with the wind tunnel data. 展开更多
关键词 viscous/inviscid interaction far-field drag prediction transonic flow wing/body configuration
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Relevance of zero lift drag coefficient and lift coefficient to Mach number for large aspect ratio winged rigid body
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作者 董素荣 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第3期270-274,共5页
Synthetic analysis is conducted to the wind tunnel experiment results of zero lift drag coefficient and lift coefficient for large aspect ratio winged rigid body.By means of wind tunnel experiment data,the dynamics mo... Synthetic analysis is conducted to the wind tunnel experiment results of zero lift drag coefficient and lift coefficient for large aspect ratio winged rigid body.By means of wind tunnel experiment data,the dynamics model of the zero lift drag coefficient and lift coefficient for the large aspect ratio winged rigid body is amended.The research indicates that the change trends of zero lift drag coefficient and lift coefficient to Mach number are similar.The calculation result and wind tunnel experiment data all verify the validity of the amended dynamics model by which to estimate the zero lift drag coefficient and lift coefficient for the large aspect ratio winged rigid body,and thus providing some technical reference to aerodynamics character analysis of the same types of winged rigid body. 展开更多
关键词 winged rigid body zero lift drag coefficient lift coefficient wind tunnel experiment dynamic characteristics
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交互式数字叙事:加拿大Writing New Body Worlds阅读治疗新探索
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作者 牟晓青 于志涛 《图书馆论坛》 CSSCI 北大核心 2024年第4期222-230,F0003,共10页
文章基于相关研究文献与语料,对加拿大WNB阅读治疗实践进行梳理与归纳。WNB首次使用交互式数字叙事技术,构建面向公众的阅读治疗平台,以其交互式特征,融合了阅读和治疗引导两个过程,提供可访问的非临床方式,可面向大规模人群实现预防性... 文章基于相关研究文献与语料,对加拿大WNB阅读治疗实践进行梳理与归纳。WNB首次使用交互式数字叙事技术,构建面向公众的阅读治疗平台,以其交互式特征,融合了阅读和治疗引导两个过程,提供可访问的非临床方式,可面向大规模人群实现预防性健康干预。基于数据与计算的精准化阅读治疗是数字人文视角下的新变革,更具推广应用价值;以在线阅读平台建设为依托,推进实施平台化的阅读和治疗应成为未来发展方向之一;基于阅读形态与体验因技术赋能而改变的现状,图书馆应发挥引领作用,积极收集、创建或协助创建数字故事,推进阅读推广、服务与治疗的融合性发展,成为社区建设促进者、历史欣赏者和社区参与倡导者,也使阅读借助交互式数字叙事这一新载体,更好地发挥变革的力量,促进健康与幸福。 展开更多
关键词 交互式数字叙事 阅读治疗 Writing New body Worlds 加拿大
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A computational study of the wing-wing and wing-body interactions of a model insect 被引量:17
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作者 Xin Yu Mao Sun 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第4期421-431,共11页
The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grid... The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of the body are less than 2%. The reason for this is as following. During each down- or up-stroke, a wing produces a vortex ring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex rings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions. 展开更多
关键词 INSECT AERODYNAMICS wing/winginteraction wing/body interaction
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The effects of corrugation and wing planform on the aerodynamic force production of sweeping model insect wings 被引量:13
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作者 Guoyu Luo Mao Sun 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2005年第6期531-541,共11页
The effects of corrugation and wing planform (shape and aspect ratio) on the aerodynamic force production of model insect wings in sweeping (rotating after an initial start) motion at Reynolds number 200 and 3500 ... The effects of corrugation and wing planform (shape and aspect ratio) on the aerodynamic force production of model insect wings in sweeping (rotating after an initial start) motion at Reynolds number 200 and 3500 at angle of attack 40℃ are investigated, using the method of computational fluid dynamics. A representative wing corrugation is considered. Wing-shape and aspect ratio (AR) of ten representative insect wings are considered; they are the wings of fruit fly, cranefly, dronefly, hoverfly, ladybird, bumblebee, honeybee, lacewing (forewing), hawkmoth and dragon- fly (forewing), respectively (AR of these wings varies greatly, from 2.84 to 5.45). The following facts are shown. (1) The corrugated and flat-plate wings produce approximately the same aerodynamic forces. This is because for a sweeping wing at large angle of attack, the length scale of the corrugation is much smaller than the size of the separated flow region or the size of the leading edge vortex (LEV). (2) The variation in wing shape can have considerable effects on the aerodynamic force; but it has only minor effects on the force coefficients when the velocity at r2 (the radius of the second :moment of wing area) is used as the reference velocity; i.e. the force coefficients are almost unaffected by the variation in wing shape. (3) The effects of AR are remarkably small: whenAR increases from 2.8 to 5.5, the force coefficients vary only slightly; flowfield results show that when AR is relatively large, the part of the LEV on the outer part of the wings sheds during the sweeping motion. As AR is increased, on one hand, the force coefficients will be increased due to the reduction of 3-dimensional flow effects; on the other hand, they will be decreased due to the shedding of part of the LEV; these two effects approximately cancel each other, resulting in only minor change of the force coefficients. 展开更多
关键词 insect flight - Sweeping wing Unsteady aerodynamics wing corrugation Planform
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Aeroelastic Analysis and Optimization of High-aspect-ratio Composite Forward-swept Wings 被引量:9
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作者 万志强 颜虹 +1 位作者 刘德广 杨超 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2005年第4期317-325,共9页
In order to analyze the effects of forward-swept angle and skin ply-orientation on the static and dynamic aeroelastic characteristics, the aeroelastic modeling and calculation for high-aspect-ratio composite wings wit... In order to analyze the effects of forward-swept angle and skin ply-orientation on the static and dynamic aeroelastic characteristics, the aeroelastic modeling and calculation for high-aspect-ratio composite wings with different forward-swept angles and skin ply-orientation are performed. This paper presents the results of a design study aiming to optimize wings with typical forward-swept angles and skin ply-orientation in an aeroelastic way by using the genetic/sensitivity-based hybrid algorithm. Under the conditions of satiated multiple constraints including strength, displacements, divergence speeds and flutter speeds, the studies are carried out in a bid to minimize the structural weight of a wing with the lay-up thicknesses of wing components as design variabies. In addition, the effects of the power of spanwise variation function of lay-up thicknesses of skins and iugs on the optimized weights are also analyzed. 展开更多
关键词 aeroeiasticity structural optimization high-aspect-ratio wing forward-swept wing COMPOSITE
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Aerodynamic Effects of Corrugation in Flapping Insect Wings in Forward Flight 被引量:11
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作者 Xueguang Meng Mao Sun 《Journal of Bionic Engineering》 SCIE EI CSCD 2011年第2期140-150,共11页
We have examined the aerodynamic effects of corrugation in model wings that closely mimic the wing movements of a forward flight bumblebee using the method of computational fluid dynamics. Various corrugated wing mode... We have examined the aerodynamic effects of corrugation in model wings that closely mimic the wing movements of a forward flight bumblebee using the method of computational fluid dynamics. Various corrugated wing models were tested (care was taken to ensure that the corrugation introduced zero camber). Advance ratio ranging from 0 to 0.57 was considered. The results shown that at all flight speeds considered, the time courses of aerodynamic force of the corrugated wing are very close to those of the flat-plate wing. The cornlgation decreases aerodynamic force slightly. The changes in the mean location of center of pressure in the spanwise and chordwise directions resulting from the corrugation are no more than 3% of the wing chord length. The possible reason for the small aerodynamic effects of wing corrugation is that the wing operates at a large angle of attack and the flow is separated: the large angle of incidence dominates the corrugation in determining the flow around the wing, and for separated flow, the flow is much less sensitive to wing shape variation. 展开更多
关键词 INSECT FLAPPING forward flight wing corrugation AERODYNAMICS
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Computational aerodynamics of low Reynolds number plunging,pitching and flexible wings for MAV applications 被引量:15
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作者 W.Shyy Y.Lian +7 位作者 J.Tang H.Liu P.Trizila B.Stanford L.Bernal C.Cesnik P.Friedmann P.Ifju 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2008年第4期351-373,共23页
Micro air vehicles (MAV's) have the potential to revolutionize our sensing and information gathering capabilities in environmental monitoring and homeland security areas. Due to the MAV's' small size, flight regi... Micro air vehicles (MAV's) have the potential to revolutionize our sensing and information gathering capabilities in environmental monitoring and homeland security areas. Due to the MAV's' small size, flight regime, and modes of operation, significant scientific advancement will be needed to create this revolutionary capability. Aerodynamics, structural dynamics, and flight dynamics of natural flyers intersects with some of the richest problems in MAV's, inclu- ding massively unsteady three-dimensional separation, transition in boundary layers and shear layers, vortical flows and bluff body flows, unsteady flight environment, aeroelasticity, and nonlinear and adaptive control are just a few examples. A challenge is that the scaling of both fluid dynamics and structural dynamics between smaller natural flyer and practical flying hardware/lab experiment (larger dimension) is fundamentally difficult. In this paper, we offer an overview of the challenges and issues, along with sample results illustrating some of the efforts made from a computational modeling angle. 展开更多
关键词 Micro air vehicles AERODYNAMICS Flexible wings Low Reynolds number
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The role of climate factors in geographic variation in body mass and wing length in a passerine bird 被引量:7
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作者 Yanfeng Sun Mo Li +3 位作者 Gang Song Fumin Lei Dongming Li Yuefeng Wu 《Chinese Birds》 CSCD 2017年第1期3-11,共9页
Background: Geographic variation in body size is assumed to reflect adaptation to local environmental conditions. Although Bergmann's rule is usually sufficient to explain such variation in homeotherms, some excep... Background: Geographic variation in body size is assumed to reflect adaptation to local environmental conditions. Although Bergmann's rule is usually sufficient to explain such variation in homeotherms, some exceptions have been documented. The relationship between altitude, latitude and body size, has been well documented for some vertebrate taxa during the past decades. However, relatively little information is available on the effects of climate variables on body size in birds.Methods: We collected the data of 267 adult Eurasian Tree Sparrow(Passer montanus) specimens sampled at 48 localities in China's mainland, and further investigated the relationships between two response variables, body mass and wing length, as well as a suit of explanatory variables, i.e. altitude, latitude, mean annual temperature(MAT), annual precipitation(PRC), annual sunshine hours(SUN), average annual wind speed(WS), air pressure(AP) and relative humidity(RH).Results: Our study showed that(1) although the sexes did not differ significantly in body mass, males had longer wings than females;(2) body mass and wing length were positively correlated with altitude but not with latitude;(3) body mass and wing length were negatively correlated with AP and RH, but not significantly correlated with WS. Body mass was positively correlated with SUN and inversely correlated with MAT. Wing length was not correlated with MAT in either sex, but was positively correlated with SUN and negatively correlated with PRC in male sparrows;(4) variation in body mass could be best explained by AP and SUN, whereas variation in wing length could be explained by RH and AP in both sexes. In addition, variation in male sparrows can be explained by SUN, WS and PRC but not in females.Conclusions: Two different proxies of body size, body mass and wing length, correlated with same geographic factors and different climate factors. These differences may reflect selection for heat conservation in the case of body mass, and for efficient flight in the case of wing length. 展开更多
关键词 body mass wing length ALTITUDE LATITUDE Climate factor Eurasian Tree Sparrow
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Wing/body kinematics measurement and force and moment analyses of the takeoff flight of fruitflies 被引量:7
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作者 Mao-Wei Chen Mao Sun 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第4期495-506,共12页
In the paper, we present a detailed analysis of the takeoff mechanics of fruitflies which perform voluntary takeoff flights. Wing and body kinematics of the insects during takeoff were measured using Based on the meas... In the paper, we present a detailed analysis of the takeoff mechanics of fruitflies which perform voluntary takeoff flights. Wing and body kinematics of the insects during takeoff were measured using Based on the measured data, high-speed video techniques. inertia force acting on the insect was computed and aerodynamic force and moment of the wings were calculated by the method of computational fluid dynamics. Subtracting the aerodynamic force and the weight from the inertia force gave the leg force. The following has been shown. In its voluntary takeoff, a fruitfly jumps during the first wingbeat and becomes airborne at the end of the first wingbeat. When it is in the air, the fly has a relatively large "initial" pitch-up rotational velocity (more than 5 000~/s) resulting from the jumping, but in about 5 wingbeats, the pitch-up rotation is stopped and the fly goes into a quasi-hovering flight. The fly mainly uses the force of jumping legs to lift itself into the air (the force from the flapping wings during the jumping is only about 5%-10% of the leg force). The main role played by the flapping wings in the takeoff is to produce a pitch-down moment to nullify the large "initial" pitch-up rotational velocity (otherwise, the fly would have kept pitching-up and quickly fallen down). 展开更多
关键词 Fruitfly· Takeoff flight ·body and wing kine-matics Aerodynamic and leg forces
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Structural Modeling and Aeroelastic Analysis of High-Aspect-Ratio Composite Wings 被引量:7
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作者 赵永辉 胡海岩 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2005年第1期25-30,共6页
A unified structural model for high-aspect-ratio composite wing with arbitrary cross-section is developed. Two types of lay-ups of the composite wing, namely, circumferentially uniform stiffness (CUS) configuration ... A unified structural model for high-aspect-ratio composite wing with arbitrary cross-section is developed. Two types of lay-ups of the composite wing, namely, circumferentially uniform stiffness (CUS) configuration and circumferentially asymmetric stiffness (CAS) configuration, are investigated. The present structural modeling method is validated through ANSYS FEM software for the case of a composite box beam. Then, the case of a single-cell composite wing with NACA0012 airfoil shape is considered. To investigate the aeroelastic problem of high-aspect-ratio composite wings, the linear ONERA aerodynamic model is used to model the unsteady aerodynamic loads under the case of small angle of attack. Finally, flutter speeds of the high-aspect-ratio wing with various composite ply angles are determined by using U-g method. 展开更多
关键词 structural modeling aeroelastic analysis high-aspect-ratio composite wing
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A simulation-based study on longitudinal gust response of flexible flapping wings 被引量:5
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作者 Toshiyuki Nakata Ryusuke Noda +1 位作者 Shinobu Kumagai Hao Liu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2018年第6期1048-1060,共13页
Winged animals such as insects are capable of flying and surviving in an unsteady and unpredictable aerial environment.They generate and control aerodynamic forces by flapping their flexible wings.While the dynamic sh... Winged animals such as insects are capable of flying and surviving in an unsteady and unpredictable aerial environment.They generate and control aerodynamic forces by flapping their flexible wings.While the dynamic shape changes of their flapping wings are known to enhance the efficiency of their flight,they can also affect the stability of a flapping wing flyer under unpredictable disturbances by responding to the sudden changes of aerodynamic forces on the wing.In order to test the hypothesis,the gust response of flexible flapping wings is investigated numerically with a specific focus on the passive maintenance of aerodynamic forces by the wing flexibility.The computational model is based on a dynamic flight simulator that can incorporate the realistic morphology,the kinematics,the structural dynamics,the aerodynamics and the fluid-structure interactions of a hovering hawkmoth.The longitudinal gusts are imposed against the tethered model of a hovering hawkmoth with flexible flapping wings.It is found that the aerodynamic forces on the flapping wings are affected by the gust,because of the increase or decrease in relative wingtip velocity or kinematic angle of attack.The passive shape change of flexible wings can,however,reduce the changes in the magnitude and direction of aerodynamic forces by the gusts from various directions,except for the downward gust.Such adaptive response of the flexible structure to stabilise the attitude can be classified into the mechanical feedback,which works passively with minimal delay,and is of great importance to the design of bio-inspired flapping wings for micro-air vehicles. 展开更多
关键词 INSECT FLIGHT FLAPPING wing FLEXIBLE wing GUST response Fluid-structure interaction Mechanical feedback
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Wings Plus设备纺22 dtex/24 f细旦聚酯FDY工艺探讨
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作者 徐兴国 陈向玲 +3 位作者 李国平 崔利 吉鹏 王华平 《合成纤维》 CAS 2020年第7期9-12,共4页
在熔体直纺装置上,采用Wings FDY Plus工艺,对22 dtex/24 f细旦聚酯全拉伸丝(FDY)的生产工艺进行了研究。通过对熔体输送温度、纺丝组件、喷丝板孔径、缓冷区、吹风冷却条件、上油条件、卷绕拉伸工艺等进行优化与控制,生产出性能优异的... 在熔体直纺装置上,采用Wings FDY Plus工艺,对22 dtex/24 f细旦聚酯全拉伸丝(FDY)的生产工艺进行了研究。通过对熔体输送温度、纺丝组件、喷丝板孔径、缓冷区、吹风冷却条件、上油条件、卷绕拉伸工艺等进行优化与控制,生产出性能优异的细旦FDY,纤维断裂强度≥4.68 cN/dtex、断裂强度CV值≤0.95%、条干不匀率≤0.63%,纤维染色效果好,无深浅丝、无条纹。 展开更多
关键词 聚酯FDY 细旦 wings PDF Plus工艺
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