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Modifications in aroma characteristics of'Merlot'dry red wines aged in American,French and Slovakian oak barrels with different toasting degrees 被引量:1
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作者 Haocheng Lu Binhao Cheng +2 位作者 Yibin Lan Changqing Duan Fei He 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期381-391,共11页
Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermen... Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious. 展开更多
关键词 Wine Aroma Oak Barrel Oak species Toasting degrees Geographic origin Aging
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Method for Evaluating the Degrees of Land Use Sustainability of Mountainous County and its Application in Yunnan Province,China 被引量:10
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作者 YANG Zisheng LIU Yansui +2 位作者 TAO Wenxing XU Jingling ZHAO Qiaogui 《Journal of Mountain Science》 SCIE CSCD 2008年第2期98-112,共15页
The evaluation of sustainable land use is the key issue in the field of studying the sustainable land utilization. In general analysis, the sustainable land use is evaluated respectively from its ecological sustainabi... The evaluation of sustainable land use is the key issue in the field of studying the sustainable land utilization. In general analysis, the sustainable land use is evaluated respectively from its ecological sustainability, economic sustainability and social sustainability in China and other countries in recent years. Although this evaluation is an important work, it seems insufficient and hard to comprehensively reflect the whole degree of land use sustainability. Thus, to make up this deficiency, this paper brings forward the evaluation indexes, which make it possible to quantitatively reflect the whole degree of land use sustainability, namely, the concept of "degrees of overall land use sustainability" (Dos), and research and measurement development of the method of and calculation in Dos. Taking the evaluation of the degree of land use sustainability in county regions of Yunnan Province as the actual example for analysis, results are basically as follows: 1) The degree of land use sustainability (Dos) is the ration index to organically and systematically integrate the degree of ecological friendliness (DeF), the degree of economic viability (Dev) and the degree of social acceptability (Dsa), able to comprehensively reflect the whole sustainability degree of regional land use 2) Based on the value of Dos, the grading system and standard for the sustainability of land use may be established and totally divided into five grades, namely, the high-degree sustainability, middle-degree sustainability, low-degree sustainability, conditional sustainability and non-sustainability. Meanwhile, the standard for distinguishing sustainability grades has also been confirmed so as to determine the nature of sustainability degrees in different grades. This makes the possibility for the combination of nature determination with ration in research result and provides with the scientific guideline and decision-making gist for better implementation of sustainable land use strategy. 3) The practice in evaluation of sustainability degree in county regional land use in Yunnan shows that the value of the degree of land use sustainability (Dos) of whole Yunnan Province is only 58.39, belonging to the grade of low-degree sustainability. Two thirds of counties in the whole province represent the grade of "conditional sustainability" and "non-sustainability" in the sustainability of land use. Among these counties, 11.11 % shows "non- sustainability'. The lowest degree of land use sustainability appears especially in the middle plateau mountain region of Northeast Yunnan, where the value of Dos in most counties (districts) is below 40 %, belonging to the grade of "non-sustainability". The sustainability degree in the karst mountainous region in lower-middle plateau mountain region in Southeast Yunnan is generally low and the value of sustainability degree (Dos) in most of the counties (cities and districts) is below 55. The value of sustainability degree (Dos) in most of the counties (cities and districts) in the north, west, northwest and southwest parts of Yunnan is below 55. This article also analyzes the reasons of low degree of sustainability in land use in Yunnan and puts forward the countermeasures to increase the degree of sustainability in land use in the whole province. 展开更多
关键词 Land use degrees of overall sustainability evaluation method county level degrees of ecological friendliness degrees of economic viability degrees of social acceptability
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Triad-displaced ULAs configuration for non-circular sources with larger continuous virtual aperture and enhanced degrees of freedom
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作者 SHAIKH Abdul Hayee DANG Xiaoyu HUANG Daqing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期81-93,共13页
Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteris... Non-uniform linear array(NULA)configurations are well renowned due to their structural ability for providing increased degrees of freedom(DOF)and wider array aperture than uniform linear arrays(ULAs).These characteristics play a significant role in improving the direction-of-arrival(DOA)estimation accuracy.However,most of the existing NULA geometries are primarily applicable to circular sources(CSs),while they limitedly improve the DOF and continuous virtual aperture for noncircular sources(NCSs).Toward this purpose,we present a triaddisplaced ULAs(Tdis-ULAs)configuration for NCS.The TdisULAs structure generally consists of three ULAs,which are appropriately placed.The proposed antenna array approach fully exploits the non-circular characteristics of the sources.Given the same number of elements,the Tdis-ULAs design achieves more DOF and larger hole-free co-array aperture than its sparse array competitors.Advantageously,the number of uniform DOF,optimal distribution of elements among the ULAs,and precise element positions are uniquely determined by the closed-form expressions.Moreover,the proposed array also produces a filled resulting co-array.Numerical simulations are conducted to show the performance advantages of the proposed Tdis-ULAs configuration over its counterpart designs. 展开更多
关键词 direction-of-arrival(DOA)estimation sparse array non-circular source(NCS) sum co-array difference co-array degrees of freedom(DOF)
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Modelling rapid non-destructive test using light weight deflectometer on granular soils across different degrees of saturation
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作者 Javad Ghorbani Arooran Sounthararajah +1 位作者 Troyee Tanu Dutta Jayantha Kodikara 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2732-2748,共17页
This study introduces an advanced finite element model for the light weight deflectometer(LWD),which integrates contact mechanics with fully coupled models.By simulating LWD tests on granular soils at various saturati... This study introduces an advanced finite element model for the light weight deflectometer(LWD),which integrates contact mechanics with fully coupled models.By simulating LWD tests on granular soils at various saturation levels,the model accurately reflects the dependence of the LWD modulus on dry density,water content,and effective stress.This model addresses and overcomes the limitations of previous finite element models for this specific problem.Simultaneously,this research presents the first experimentally validated fully coupled contact impact model.Furthermore,the research provides a comparative assessment of elastoplastic and nonlinear elastic models and contrasts an enriched node-tosegment method(developed in this study)with the more precise mortar technique for contact mechanics.These comparisons reveal unique advantages and challenges for each method.Moreover,the study underscores the importance of careful application of the LWD modulus,emphasising the need for sophisticated tools to interpret soil behaviour accurately. 展开更多
关键词 Granular soils PLASTICITY Finite element analysis Contact mechanics MODULUS Degree of saturation
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Health effects of fruit juices and beverages with varying degrees of processing
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作者 Xinyue Zhang Xiaojun Liao +2 位作者 Yongtao Wang Lei Rao Liang Zhao 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期2456-2479,共24页
The degree of processing is rarely considered an independent factor in the health effects of fruit juices and beverages(FJBs)consumption.In fact,the consumption of ultra-processed foods has been shown to pose health r... The degree of processing is rarely considered an independent factor in the health effects of fruit juices and beverages(FJBs)consumption.In fact,the consumption of ultra-processed foods has been shown to pose health risks.In this study,we first integrated 4 systems used to classify the degree of food processing and then classified FJBs into three major categories,low(minimal),moderate and high.Second,we compared the differences in attitudes towards FJBs in dietary guidelines.Third,we integrated the results of existing epidemiological surveys,randomized controlled trials,and animal experiments to explore the health risks associated with consuming FJBs.Deepening the processing of FJBs has been found to lead to an increased risk of diseases.Dietary pattern,nutrients,addition agents and consumer preferences may be influential factors.Finally,we investigated whether there were any changes in the health benefits of 100%fruit juices produced by different processing methods.In conclusion,minimally/moderately processed 100%fruit juices provide more health benefits than highly processed fruit beverages.The results support the need to consider the extent of FJBs processing in future studies to adjust official nutritional recommendations for beverage consumption. 展开更多
关键词 Fruit juices and beverages Dietary guidelines Degree of processing Health effects MECHANISM
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Antoioxidant Activity of Carboxymethyl Chitosan with Different Substituted Degrees 被引量:15
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作者 姚倩 孙涛 +1 位作者 周冬香 毛芳 《Agricultural Science & Technology》 CAS 2008年第1期5-7,59,共4页
[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan (NOA, NOB and NOC)with various degrees of substitution (D... [Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan (NOA, NOB and NOC)with various degrees of substitution (DS)were obtained by etherizing chito-oligosacchaside. Their structure and substituted degree were characterized and their antioxldant activity to·OH was evaluated. [ Result] The IC50 s of NOA ,NOB and NOC were 0.15 ,0. 29 ,0. 23 mg/ml while their DSs of -NH2 position(DSN) were 0.51,0.29 and 0.38 and DSo were 0. 74 ,0. 84 ,0. 97respectively.[ Conclusion] With the increase of DSN ,antioxidant activity of N,O-carboxymethyl chitosan oligosaccharide to·OH was up. 展开更多
关键词 Chitosan oligosaccharide Carboxymethyl chitosan oligosaccharide Degree of substitution Antioxidant activity
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Experimental Study on Interaction Between Degrees of Freedom in a Wave Buoy 被引量:6
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作者 HUANG Shuting SHI Hongda +6 位作者 CAO Feifei TAN Junzhe CHENG Haixun LI Demin LIU Shangze GONG Haoxiang TAO Ji 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第6期1256-1264,共9页
Increasing degrees of freedom(DOFs)is a useful way to raise the power capture efficiency of oscillating wave energy converters.Thus,this study proposes a buoy with three DOFs,which are surge,heave,and pitch.The hydrod... Increasing degrees of freedom(DOFs)is a useful way to raise the power capture efficiency of oscillating wave energy converters.Thus,this study proposes a buoy with three DOFs,which are surge,heave,and pitch.The hydrodynamic performance and power capture efficiency of the buoy is physically modeled.Amplitudes of unidirectional and coupled motions are compared to analyze the interaction effect between freedoms under conditions with and without power take-off damping.The capture width ratio and corresponding growth rates are also calculated.Results show that the buoy makes a periodic sinusoidal(or approximate)movement in every DOF.Coupling effect can cause an increase in the amplitude in one DOF and a decrease in the amplitudes of the others.This phenomenon shows that the kinematic energy of the buoy redistributes to all DOFs compared with the unidirectional conditions.Adding DOFs can improve the power absorption of the buoy in most cases,but the number of DOFs is not the more the better. 展开更多
关键词 WAVE energy OSCILLATING BUOY multiple degrees of FREEDOM
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Modified Two-Degrees-of-Freedom Internal Model Control for Non-Square Systems with Multiple Time Delays 被引量:25
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作者 Jian-Chang Liu Nan Chen Xia Yu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第2期122-128,共7页
A modified two-degrees-of-freedom( M-TDOF) internal model control( IMC) method is proposed for non-square systems with multiple time delays and right-half-plane( RHP) zeros. In this method,pseudo-inverse is introduced... A modified two-degrees-of-freedom( M-TDOF) internal model control( IMC) method is proposed for non-square systems with multiple time delays and right-half-plane( RHP) zeros. In this method,pseudo-inverse is introduced to design the internal model controller,and a desired closed-loop transfer function is designed to eliminate the unrealizable factors of the derived controller. In addition,set-point tracking and load-disturbance rejection of each process are separately controlled by two controllers. The simulation results show that in addition to high decoupling performance and robustness,the proposed control method also effectively improves loaddisturbance rejection and simultaneously optimizes the input tracking performance and disturbance rejection performance by selecting the parameters of controllers. Furthermore,the higher tolerance of model mismatch is achieved in this paper. 展开更多
关键词 non-square system two degrees of freedom internal model control
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System Identification Modeling of Ship Manoeuvring Motion in 4 Degrees of Freedom Based on Support Vector Machines 被引量:7
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作者 王雪刚 邹早建 +1 位作者 余龙 蔡韡 《China Ocean Engineering》 SCIE EI CSCD 2015年第4期519-534,共16页
Based on support vector machines, three modeling methods, i.e., white-box modeling, grey-box modeling and black-box modeling of ship manoeuvring motion in 4 degrees of freedom are investigated. With the whole-ship mat... Based on support vector machines, three modeling methods, i.e., white-box modeling, grey-box modeling and black-box modeling of ship manoeuvring motion in 4 degrees of freedom are investigated. With the whole-ship mathematical model for ship manoeuvring motion, in which the hydrodynamic coefficients are obtained from roll planar motion mechanism test, some zigzag tests and turning circle manoeuvres are simulated. In the white-box modeling and grey-box modeling, the training data taken every 5 s from the simulated 20°/20° zigzag test are used, while in the black-box modeling, the training data taken every 5 s from the simulated 15°/15°, 20°/20° zigzag tests and 15°, 25° turning manoeuvres are used; and the trained support vector machines are used to predict the whole 20°/20° zigzag test. Comparisons between the simulated and predicted 20°/20° zigzag tests show good predictive ability of the proposed methods. Besides, all mathematical models obtained by the proposed modeling methods are used to predict the 10°/10° zigzag test and 35° turning circle manoeuvre, and the predicted results are compared with those of simulation tests to demonstrate the good generalization performance of the mathematical models. Finally, the proposed modeling methods are analyzed and compared with each other in aspects of application conditions, prediction accuracy and computation speed. The appropriate modeling method can be chosen according to the intended use of the mathematical models and the available data needed for system identification. 展开更多
关键词 ship manoeuvring 4 degrees of freedom system identification support vector machines
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Trimming the Degrees of Freedom via a K^(+) Flux Rectifier for Safe and Long‑Life Potassium‑Ion Batteries 被引量:3
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作者 Xianhui Yi Apparao MRao +1 位作者 Jiang Zhou Bingan Lu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第11期157-171,共15页
High degrees of freedom(DOF)for K^(+)movement in the electrolytes is desirable,because the resulting high ionic conductivity helps improve potassium-ion batteries,yet requiring support from highly free and flammable o... High degrees of freedom(DOF)for K^(+)movement in the electrolytes is desirable,because the resulting high ionic conductivity helps improve potassium-ion batteries,yet requiring support from highly free and flammable organic solvent molecules,seriously affecting battery safety.Here,we develop a K^(+)flux rectifier to trim K ion’s DOF to 1 and improve electrochemical properties.Although the ionic conductivity is compromised in the K^(+)flux rectifier,the overall electrochemical performance of PIBs was improved.An oxidation stability improvement from 4.0 to 5.9 V was realized,and the formation of dendrites and the dissolution of organic cathodes were inhibited.Consequently,the K||K cells continuously cycled over 3,700 h;K||Cu cells operated stably over 800 cycles with the Coulombic efficiency exceeding 99%;and K||graphite cells exhibited high-capacity retention over 74.7%after 1,500 cycles.Moreover,the 3,4,9,10-perylenetetracarboxylic diimide organic cathodes operated for more than 2,100 cycles and reached year-scale-cycling time.We fabricated a 2.18 Ah pouch cell with no significant capacity fading observed after 100 cycles. 展开更多
关键词 Electrolytes degrees of freedom SAFE Coulombic efficiency Potassium-ion batteries
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Type Synthesis of Two-Degrees-of-Freedom Rotational Parallel Mechanism with Two Continuous Rotational Axes 被引量:19
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作者 XU Yundou ZHANG Dongsheng +2 位作者 WANG Min YAO Jiantao ZHAO Yongsheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期694-702,共9页
The two-rotational-degrees-of-freedom(2R) parallel mechanism(PM) with two continuous rotational axes(CRAs) has a simple kinematic model.It is therefore easy to implement trajectory planning,parameter calibration... The two-rotational-degrees-of-freedom(2R) parallel mechanism(PM) with two continuous rotational axes(CRAs) has a simple kinematic model.It is therefore easy to implement trajectory planning,parameter calibration,and motion control,which allows for a variety of application prospects.However,no systematic analysis on structural constraints of the 2R-PM with two CRAs has been performed,and there are only a few types of 2R-PM with two CRAs.Thus,a theory regarding the type synthesis of the 2R-PM with two CRAs is systematically established.First,combining the theories of reciprocal screw and space geometry,the spatial arrangement relationships of the constraint forces applied to the moving platform by the branches are explored,which give the 2R-PM two CRAs.The different distributions of the constraint forces in each branch are also studied.On the basis of the obtained structural constraints of branches,and considering the geometric relationships of constraint forces in each branch,the appropriate kinematic chains are constructed.Through the reasonable configuration of branch kinematic chains corresponding to every structural constraint,a series of new 2R-PMs with two CRAs are finally obtained. 展开更多
关键词 type synthesis continuous rotational axes two rotational degrees of freedom parallel mechanism constraint force
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Design and Analysis of a Magnetic Bearings with Three Degrees of Freedom 被引量:1
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作者 Ye Yuan Yukun Sun Qianwen Xiang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第1期142-151,共10页
The current research of supporting and transmission system in flywheel energy storage system(FESS) focuses on the low consumption design. However, friction loss is a non-negligible factor in the high-speed but lightwe... The current research of supporting and transmission system in flywheel energy storage system(FESS) focuses on the low consumption design. However, friction loss is a non-negligible factor in the high-speed but lightweight FESS energy and momentum storage with mechanical-type supporting system. In order to realize the support system without mechanical loss and to maximize the e ciency of the flywheel battery, a permanent magnet biased magnetic bearings(PMBMB) is applied to the FESS with the advantages of low loss, high critical speed, flexible controllability and compact structure. In this frame, the relevant research of three degrees of freedom(3-DOF) PMBMB for a new type FESS is carried out around the working principle, structural composition, coupling characteristics analysis, mathematical model, and structural design. In order to verify the performance of the 3-DOF PMBMB, the radial force mathematical model and the coupling determination equations of radial two DOF are calculated according to an equivalent magnetic circuit, and radial–axial coupling is analyzed through finite element analysis. Moreover, a control system is presented to solve the control problems in practical applications. The rotor returns to the balanced position in 0.05 s and maintains stable suspension. The displacement fluctuation is approximately 40 μm in the y direction and 30 μm in the x direction. Test results indicate that the dynamic rotor of the proposed flywheel energy storage system with PMBMB has excellent characteristics, such as good start-of-suspension performance and stable suspension characteristics. The proposed research provides the instruction to design and control a low loss support system for FESS. 展开更多
关键词 FLYWHEEL energy storage system Magnetic bearings degrees of FREEDOM Coupling FINITE ELEMENT analysis
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Effect of modification degrees on the interfacial properties and EOR efficiency of amphiphilic Janus graphene oxide 被引量:1
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作者 Han Jia Xin Wei +7 位作者 Qiu-Xia Wang Yuan-Bo Wang Shi-Jie Wen Fang-Ning Fan Qiang Wang Zhe Wang De-Xin Liu Pan Huang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期1217-1224,共8页
Asymmetrically modified Janus graphene oxide(JGO)has attracted great attention due to its unique physical chemistry properties and wide applications.The modification degree of Janus nanosheets inevitably affects their... Asymmetrically modified Janus graphene oxide(JGO)has attracted great attention due to its unique physical chemistry properties and wide applications.The modification degree of Janus nanosheets inevitably affects their interfacial activity,which is essential for their performances in enhanced oil recovery(EOR).In this study,the interfacial properties of Janus graphene oxide(JGO)with various modification degrees at liquid-liquid and liquid-solid interfaces were systematically evaluated via the measurements of interfacial tension(IFT),dilatational modulus,contact angle,and EOR efficiency was further assessed by core flooding tests.It is found that JGO-5 with higher modification degree exhibits the greater ability to reduce IFT(15.16 mN/m)and dilatational modulus(26 mN/m).Furthermore,JGO can construct interfacial and climbing film with the assistance of hydrodynamic power to effectively detach the oil from the rock surface and greatly enhance oil recovery.Moderately modified JGO-2 can highly improve recovery of residual crude oil(11.53%),which is regarded as the promising EOR agent in practical application.The present study firstly focuses on the effects of modification degrees on the JGO interfacial properties and proposes diverse EOR mechanisms for JGO with different modification degrees. 展开更多
关键词 Graphene oxide Modification degrees Janus nanosheets Interfacial film EOR
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Behavior of Vortex-Induced Vibration of A Circular Cylinder Near A Deformable Wall with Two Degrees of Freedom in Steady Flow 被引量:1
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作者 杨兵 马建林 +1 位作者 崔金声 徐万海 《China Ocean Engineering》 SCIE EI 2011年第4期549-564,共16页
The behavior of vortex-induced vibration of a two-degree-of-freedom cylinder near a deformable wall in steady flow is investigated experimentally. The typical phenomenon of the two-degree-of-freedom cylinder's VIV is... The behavior of vortex-induced vibration of a two-degree-of-freedom cylinder near a deformable wall in steady flow is investigated experimentally. The typical phenomenon of the two-degree-of-freedom cylinder's VIV is discussed. The influences of initial gap between the cylinder and the wall on the dynamic responses of the cylinder are analyzed. The comparison is made about dynamic responses of the cylinder with one and two degrees of freedom. Experimental results show that the vibration of the cylinder near a deformable wall with a small value of initial gap-to-diameter ratios can generally be divided into two phases. The initial gap-to-diameter ratios have a noticeable influence on the occurrence of transverse vibration. The transverse maximum amplitude of the cylinder with two degrees of freedom is larger than that of the cylinder with one degree of freedom under the condition with the same values of other parameters. However, the vibration frequency of the cylinder for the two degrees of freedom case is smaller than that for the one degree of freedom case at the same value of Vr number 展开更多
关键词 vortex-induced vibration two degrees of freedom deformable wall circular cylinder steady flow
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Design and Analysis of a Novel Compliant Mechanism with RPR Degrees of Freedom 被引量:1
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作者 Shuang Zhang Jingfang Liu Huafeng Ding 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2022年第5期262-274,共13页
A novel compliant mechanism with RPR degrees of freedom(DOF)is proposed where R and P represent rotation and translation DOFs,respectively.The proposed compliant mechanism is obtained from dimension synthesizing a 2-R... A novel compliant mechanism with RPR degrees of freedom(DOF)is proposed where R and P represent rotation and translation DOFs,respectively.The proposed compliant mechanism is obtained from dimension synthesizing a 2-RPU-UPR rigid parallel mechanism with the method of optimization of motion/force transfer characteristic.R,P and U represent rotation,translation and universal pairs,respectively.Firstly,inverse kinematics and Jacobian matrix are analyzed for the dimensional synthesis.Then,output transmission indexes of branches in the parallel mechanism are given.Dimensional synthesis is completed based on the normalized design parameter.And optimization of flexure joints based on constrained energy is carried out.Afterwards,the novel compliant mechanism is obtained by direct replacing method.Mechanical model of the compliant mechanism including static stiffness and input stiffness is built based on the pseudo-rigid body modeling method and virtual work principle.Finally,FEA simulation by Ansys Workbench is carried out to verify DOF,effectiveness of the dimension synthesis,and compliant model.Optimization of motion/force transfer characteristic is first applied for the design of compliant mechanisms to suppress drift of rotation axis in the paper. 展开更多
关键词 Compliant mechanism RPR degrees of freedom Motion/force transfer characteristic Mechanical model OPTIMIZATION
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A quadrilateral membrane hybrid stress element with drilling degrees of freedom 被引量:1
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作者 An-Ping Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第5期1367-1373,共7页
A new kind of quadrilateral assumed stress hy- brid membrane element with drilling degrees of freedom and a traction-free inclined side has been developed based on an extended Hellinger-Reissner principle which is est... A new kind of quadrilateral assumed stress hy- brid membrane element with drilling degrees of freedom and a traction-free inclined side has been developed based on an extended Hellinger-Reissner principle which is established by expanding the essential terms of the assumed stress field as polynomials in the natural coordinates of the element. The homogeneous equilibrium equations are imposed in a variational sense through the internal displacements which are also expanded in the natural coordinates, while the tractionfree conditions along the inclined side are satisfied exactly. The use of such special element in the finite element solution is shown to be highly accurate when only a very coarse element mesh is used for plates with V-shaped rounded notches or inclined sides. 展开更多
关键词 Hybrid stress element Drilling degrees of free-dom Stress concentration Traction-free inclined side
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Design and Development of a Competitive Low-Cost Robot Arm with Four Degrees of Freedom 被引量:2
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作者 Ashraf Elfasakhany Eduardo Yanez +1 位作者 Karen Baylon Ricardo Salgado 《Modern Mechanical Engineering》 2011年第2期47-55,共9页
The main focus of this work was to design, develop and implementation of competitively robot arm with en- hanced control and stumpy cost. The robot arm was designed with four degrees of freedom and talented to accompl... The main focus of this work was to design, develop and implementation of competitively robot arm with en- hanced control and stumpy cost. The robot arm was designed with four degrees of freedom and talented to accomplish accurately simple tasks, such as light material handling, which will be integrated into a mobile platform that serves as an assistant for industrial workforce. The robot arm is equipped with several servo motors which do links between arms and perform arm movements. The servo motors include encoder so that no controller was implemented. To control the robot we used Labview, which performs inverse kinematic calculations and communicates the proper angles serially to a microcontroller that drives the servo motors with the capability of modifying position, speed and acceleration. Testing and validation of the robot arm was carried out and results shows that it work properly. 展开更多
关键词 ROBOT Arm LOW-COST Design Validation FOUR degrees of FREEDOM SERVO Motors Arduino ROBOT CONTROL Labview ROBOT CONTROL
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Asymptotic dynamics of the alternate degrees of freedom for a two-mode system:An analytically solvable model
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作者 M.Arsenijevi J.Jekni-Dugi M.Dugi 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期71-75,共5页
The composite systems can be non-uniquely decomposed into parts(subsystems).Not all decompositions(structures) of a composite system are equally physically relevant.In this paper we answer on theoretical ground wh... The composite systems can be non-uniquely decomposed into parts(subsystems).Not all decompositions(structures) of a composite system are equally physically relevant.In this paper we answer on theoretical ground why it may be so.We consider a pair of mutually un-coupled modes in the phase space representation that are subjected to the independent quantum amplitude damping channels.By investigating asymptotic dynamics of the degrees of freedom,we find that the environment is responsible for the structures non-equivalence.Only one structure is distinguished by both locality of the environmental influence on its subsystems and a classical-like description. 展开更多
关键词 amplitude dissipative channel two-mode state Kraus representation alternate degrees of freedom
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Precipitation Change and Agricultural Drought and Flood Degrees during Crop Growth Season in Binzhou City
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作者 Cai Yongwei Ren Jiancheng 《Meteorological and Environmental Research》 CAS 2014年第3期46-48,共3页
[Objective]The research aimed to analyze precipitation change and agricultural drought and flood degrees during crop growth season in Binzhou.[Method]Based on monthly rainfall and average temperature data at Binzhou m... [Objective]The research aimed to analyze precipitation change and agricultural drought and flood degrees during crop growth season in Binzhou.[Method]Based on monthly rainfall and average temperature data at Binzhou meteorological observatory during March-November of1981-2010,by using linear regression,climatic tendency rate and dry-wet coefficient,precipitation change and agricultural drought and flood degrees during crop growth season of the past 30 years in Binzhou were analyzed from natural precipitation tendency change and satisfaction degree of agricultural water demand during crop growth season.[Result]In the past 30 years,precipitation during growth season in Binzhou presented increasing tendency.Spring,summer and autumn precipitation all increased somewhat,especially summer precipitation.Monthly average rainfall distribution was very uneven,and rainfall in July and August was more.In the past 30 years,average dry-wet coefficient K value during crop growth season in Binzhou was 0.60,it overall belonged to moderate drought climate type,and occurrence frequency of drought was 97%.It belonged to serious drought climate type in spring and autumn and light drought climate type in summer.Dry-wet coefficient presented rising tendency,illustrating that climate was developing toward wet direction.Seen from mean over the years,except humid in July,it was over light drought in other months.[Conclusion]Climate was overall arid during crop growth season in Binzhou,but precipitation somewhat increased in the past 30 years.Therefore,we suggested that artificial rainfall work should be enhanced. 展开更多
关键词 Crop growth season PRECIPITATION Drought and flood degrees Binzhou China
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Comparison of detection results of hypoxic-ischemic encephalopathy at different degrees in infant patients between brain electrical activity mapping, transcranial Doppler sonography and computer tomography examinations
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作者 Dongruo He Xiaoying Xu +1 位作者 Yinghui Zhang Guochao Han 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第4期379-381,共3页
BACKGROUND: It has been proved that brain electrical activity mapping (BEAM) and transcranial Doppler (TCD) detection can reflect the function of brain cell and its diseased degree of infant patients with moderat... BACKGROUND: It has been proved that brain electrical activity mapping (BEAM) and transcranial Doppler (TCD) detection can reflect the function of brain cell and its diseased degree of infant patients with moderate to severe hypoxic-ischemic encephalopathy (HIE). OBJECTIVE: To observe the abnormal results of HIE at different degrees detected with BEAM and TCD in infant patients, and compare the detection results at the same time point between BEAM, TCD and computer tomography (CT) examinations. DESIGN : Contrast observation SETTING: Departments of Neuro-electrophysiology and Pediatrics, Second Affiliated Hospital of Qiqihar Medical College. PARTICIPANTS: Totally 416 infant patients with HIE who received treatment in the Department of Newborn Infants, Second Affiliated Hospital of Qiqihar Medical College during January 2001 and December 2005. The infant patients, 278 male and 138 female, were at embryonic 37 to 42 weeks and weighing 2.0 to 4.1 kg, and they were diagnosed with CT and met the diagnostic criteria of HIE of newborn infants compiled by Department of Neonatology, Pediatric Academy, Chinese Medical Association. According to diagnostic criteria, 130 patients were mild abnormal, 196 moderate abnormal and 90 severe abnormal. The relatives of all the infant patients were informed of the experiment. METHOOS: BEAM and TCD examinations were performed in the involved 416 infant patients with HIE at different degrees with DYD2000 16-channel BEAM instrument and EME-2000 ultrasonograph before preliminary diagnosis treatment (within 1 month after birth) and 1,3,6,12 and 24 months after birth, and detected results were compared between BEAM, TCD and CT examinations. MAIN OUTCOME MEASURES: Comparison of detection results of HIE at different time points in infant patients between BEAM. TCD and CT examinations. RESULTS: All the 416 infant patients with HIE participated in the result analysis. (1) Comparison of the detected results in infant patients with mild HIE at different time points after birth between BEAM, TCD and CT examinations: BEAM examination showed that the recovery was delayed, and the abnormal rate of BEAM examination was significantly higher than that of CT examination 1 and 3 months after birth [55.4%(72/130)vs. 17.0% (22/130 ),x^2=41.66 ;29.2% ( 38/130 ) vs. 6.2% ( 8/130 ), x^2=23.77, P 〈 0.01 ], exceptional patients had mild abnormality and reached the normal level in about 6 months. TCD examination showed that the disease condition significantly improved and infant patients with HIE basically recovered 1 or 2 months after birth, while CT examination showed that infant patients recovered 3 or 4 months after birth. (2) Comparison of detection results of infant patients with moderate HIE at different time points between BEAM, TCD and CT examinations: The abnormal rate of BEAM examination was significantly higher than that of CT examination 1,3,6 and 12 months after birth [90.8% (178/196),78.6% (154/196),x^2=4.32,P 〈 0.05;64.3% (126/196),43.9% (86/196) ,x^2=16.44 ;44.9% (88/196) ,22.4% (44/196),x^2=22.11 ;21.4% (42/196), 10.2% (20/196),x^2=9.27, P 〈 0.01]. BEAM examination showed that there was still one patient who did not completely recovered in the 24^th month due to the relatives of infant patients did not combine the treatment,. TCD examination showed that the abnormal rate was 23.1%(30/196)in the 1^st month after birth, and all the patients recovered to the normal in the 3^rd month after birth, while CT examination showed that mild abnormality still existed in the 24^th month after birth (1.0% ,2/196). (3) Comparison of detection results of infant patients with severe HIE at different time points between BEAM, TCD and CT examinations: The abnormal rate of BEAM examination was significantly higher than that of CT examination in the 1^st, 3^rd, 6^th and 12^th months after birth[86.7% (78/90),44.4% (40/90),x^2=35.53;62.2% (56/90),31.1% (28/90),x^2=17.51 ;37.8% (34/90),6.7% (6/90), x^2=27.14, P 〈 0.01]. BEAM examination showed that mild abnormality still existed in 4 infant patients in the 24^th month after birth. TCD examination showed that the abnormal rate was 11.1% (10/90) in the 3^rd month after birth, and all the infant patients recovered in the 6^th month after birth. CT examination showed that the abnormal rate was 6.7%(6/90) in the 12^th month after birth, and all of infant patients recovered to the normal in the 24^th month after birth.CONCLUSION : BEAM is the direct index to detect brain function of infant patients with HIE, and positive reaction is still very sensitive in the tracking detection of convalescent period. The positive rate of morphological reaction in CT examination is superior to that in TCD examination, and the positive rate is very high in the acute period of HIE in examination. 展开更多
关键词 HIE Comparison of detection results of hypoxic-ischemic encephalopathy at different degrees in infant patients between brain electrical activity mapping transcranial Doppler sonography and computer tomography examinations
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