|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Displacement manifold method for type synthesis of lower-mobility parallel mechanisms显示文摘Type synthesis of lower-mobility parallel mechanisms is a hot and frontier topic in international academic and industrial field. Based on the Lie group theory, a displacement manifold synthesis method is proposed. For all the nine kinds of lower-mobility parallel mechanisms, the mechanism displacement manifold, limb displacement manifold and the geometrical conditions which guarantee that the intersection of the limb displacement manifold is the desired mechanism displacement manifold are enumerated. Various limb kinematic chains can be obtained using the product closure of displacement subgroup. Parallel mechanisms can be constructed with these limbs while obeying the geometrical conditions. Hence, all the nine kinds of lower-mobility parallel mechanisms can be synthesized using this method. Since displacement manifold deals with finite motion, the result mechanism of synthesis have full-cycle mobility. Novel architectures of lower-mobility parallel mechanisms can be obtained using this method. | LI Qinchuan HUANG Zhen Jacques Marie Hervé | 2004 | Science China(Technological Sciences)2004，47，6： | 28 |
| 2 | Singularity Analysis of a 3-RPS Parallel Manipulator Using Geometric Algebra显示文摘Singular configurations must be avoided in path planning and control of a parallel manipulator. However, most studies rarely focus on an overall singularity loci distribution of lower-mobility parallel mechanisms. Geometric algebra is employed in analysis of singularity of a 3-RPS parallel manipulator. Twist and wrench in screw theory are represented in geometric algebra. Linear dependency of twists and wrenches are described by outer product in geometric algebra. Reciprocity between twists and constraint wrenches are reflected by duality. To compute the positions of the three spherical joints of the 3-RPS parallel manipulator, Tilt-and-Torsion angles are used to describe the orientation of the moving platform. The outer product of twists and constraint wrenches is used as an index for closeness to singularity(ICS) of the 3-RPS parallel manipulator. An overall and thorough perspective of the singularity loci distribution of the 3-RPS parallel manipulator is disclosed, which is helpful to design, trajectory planning and control of this kind of parallel manipulator. | LI Qinchuan XIANG Ji'nan CHAI Xinxue WU Chuanyu | 2015 | Chinese Journal of Mechanical Engineering2015，28，6： | 12 |
| 3 | New Family of RPR-Equivalent Parallel Mechanisms:Design and Application显示文摘Parallel mechanisms(PMs)have been used as skeletons or end-effectors in various advanced manufacturing equipment.Compared with their serial counterparts,PMs offer high rigidity,good dynamic response,and large payload capability.Three-degrees-of-freedom(DOFs)parallel mechanisms with two rotational and one translational(2R1T)motion are particularly useful,such as | Qinchuan LI Lingmin XU Qiaohong CHEN Wei YE | 2017 | Chinese Journal of Mechanical Engineering2017，30，2： | 12 |
| 4 | PCA-based sea-ice image fusion of optical data by HIS transform and SAR data by wavelet transform显示文摘Sea ice as a disaster has recently attracted a great deal of attention in China. Its monitoring has become a routine task for the maritime sector. Remote sensing, which depends mainly on SAR and optical sensors, has become the primary means for sea-ice research. Optical images contain abundant sea-ice multi-spectral information, whereas SAR images contain rich sea-ice texture information. If the characteristic advantages of SAR and optical images could be combined for sea-ice study, the ability of sea-ice monitoring would be improved. In this study, in accordance with the characteristics of sea-ice SAR and optical images, the transformation and fusion methods for these images were chosen. Also, a fusion method of optical and SAR images was proposed in order to improve sea-ice identification. Texture information can play an important role in sea-ice classification. Haar wavelet transformation was found to be suitable for the sea-ice SAR images, and the texture information of the sea-ice SAR image from Advanced Synthetic Aperture Radar(ASAR) loaded on ENVISAT was documented. The results of our studies showed that, the optical images in the hue-intensity-saturation(HIS) space could reflect the spectral characteristics of the sea-ice types more efficiently than in the red-green-blue(RGB) space, and the optical image from the China-Brazil Earth Resources Satellite(CBERS-02B) was transferred from the RGB space to the HIS space. The principal component analysis(PCA) method could potentially contain the maximum information of the sea-ice images by fusing the HIS and texture images. The fusion image was obtained by a PCA method, which included the advantages of both the sea-ice SAR image and the optical image. To validate the fusion method, three methods were used to evaluate the fused image, i.e., objective, subjective, and comprehensive evaluations. It was concluded that the fusion method proposed could improve the ability of image interpretation and sea-ice identification. | LIU Meijie DAI Yongshou ZHANG Jie ZHANG Xi MENG Junmin XIE Qinchuan | 2015 | Acta Oceanologica Sinica2015，34，3： | 11 |
| 5 | ML integer frequency offset estimation for OFDM systems with null subcarriers:Estimation range and pilot design显示文摘In this paper the estimation range(ERG) of any null subcarriers(NSC) placement is further investigated and sufficient and necessary conditions of an NSC allocation that achieves a full ERG are defined.Then,a perfect distributed NSC allocation with the NSC distance larger than coherent bandwidth is devised to fully exploit frequency diversity of wireless channels and achieve a full ERG.Simulations confirmed that the propsoed FFT-based ML method of using this NSC placement has a smaller bandwidth overhead,achieves a fuller ERG and provides a better performance than the existing methods of using the consecutive NSC allocation at middle and high signal-to-noise ratios(SNRs). | SHU Feng BERBER Stevan WANG DongMing ZHANG QinChuan WANG Mao | 2010 | Science China(Information Sciences)2010，53，12： | 8 |
| 6 | Gua Sha attenuates thermal hyperalgesia and decreases proinflammatory cytokine expression in serum in rats with lumbar disc herniation induced by autologous nucleus pulposus显示文摘OBJECTIVE: To investigate the analgesic effect of Gua Sha and its underlying mechanism in rats with noncompressive lumbar disk herniation induced by autologous nucleus pulposus.METHODS: A rat model of noncompressive lumbar disk herniation was established and rats were randomly divided into model group, sham group, and Gua Sha group(24 in each group). Gua Sha was performed from the 5 th day after the surgery, once every other day, 3 times for a course of treatment,and totally 3 courses. The thermal withdrawal latency was evaluated using the intelligent hot plate one day before the surgery, and on days 4(the day before the treatment), 10(the end of the firstcourse), 16(the end of the second course) and 22(the end of the third course). On days 4, 10, 16 and22, six rats in each group were picked randomly and their blood samples were drawn to assess the expression of interleukin-1β(IL-1β), interleukin-6(IL-6) and tumor necrosis factor-alpha(TNF-α).RESULTS: Compared to rats in the sham group, the application of nucleus pulposus to right L5 dorsal root ganglion induced prolonged thermal hyperalgesia, and up-regulated the expression of IL-1β,IL-6 and TNF-α in serum(P < 0.01). The therapy of Gua Sha attenuated thermal hyperalgesia potently,inhibited the expression of IL-1β, IL-6 and TNF-α in a time-dependent manner(P < 0.01). There were no significant differences in the thermal withdrawal latency and the expression of inflammatory cytokines between the sham and Gua Sha groups at the end of the treatment(P > 0.01).CONCLUSION: The current study showed that Gua Sha might alleviate thermal hyperalgesia in rats with lumbar disc herniation induced by autologous nucleus pulposus via inhibiting the expression of proinflammatory cytokins. | Yang Min Zhang Hongyan Yue Rongzhao Shi Qinchuan Bian Yaoyao Xu Guihua | 2018 | Journal of Traditional Chinese Medicine2018，38，5： | 7 |
| 7 | Mobility,Constraint Singularity and Isotropy of the 3-R Translational Parallel Mechanism显示文摘The non-overconstrained 3-degrees of freedom(DOF) translational parallel mechanism(TPM) has received much attention due to its advantages in reduced cost of fabrication and assembly. Researches are being conducted in the area of type synthesis, kinematic analysis and dimensional synthesis. Mobility, constraint singularity and isotropy of a 3-R non-overconstrained TPM are studied, where P denote the prismatic pair, R the revolute pair and the overline indicates the same axis direction of the kinematic pair. The different arrangements of the three limbs affect the kinematic performance of this kind of TPM. First, the mobility analysis, actuation selection, and the constraint singularity of the general 3-R TPM are conducted based on screw theory. For a general 3-R TPM, the three prismatic pairs cannot be chosen as actuators and two kinds of constraint singularities are identified. In the first constraint singularity, the moving platform has four instantaneous DOFs. In the second constraint singularity, the moving platform has five instantaneous DOFs. Then, an orthogonal 3-R TPM is proposed, which can be actuated by three prismatic pairs and has no constraint singularities. Further, the forward and inverse kinematic analysis of the orthogonal TPM are presented. The input-output equations of the orthogonal TPM are totally decoupled. The full isotropy of the orthogonal TPM is proved by establishing the Jacobian matrix , which is an identity 3×3 diagonal matrix in the whole workspace. The orthogonal3-R TPM has great potential in application like fast pick-and-place manipulator, parallel machine and micro-motion manipulator. | CHEN Qiaohong LI Qinchuan WU Chuanyu LI Yi | 2009 | Chinese Journal of Mechanical Engineering2009，22，6： | 7 |
| 8 | Improving the quantification of waterfowl migration with remote sensing and bird tracking显示文摘Accurately quantifying waterfowl migration patterns is pertinent to monitor ecosystem health and control bird-borne infectious diseases. In this review, we summarize the current understanding of the environmental mechanisms that drive waterfowl migration and then investigate the effect of intra- and inter-annual change in food supply and temperature(e.g., climate change) on their migration patterns. Recent advances in remote sensing and animal tracking techniques make it possible to monitor these environmental factors over a wide range of scales and record bird movements in detail. The synergy of these techniques will facilitate substantial progress in our understanding of the environmental drivers of bird migration. We identify prospects for future studies to test existing hypotheses and develop models integrating up-todate knowledge, high-resolution remote sensing data and high-accuracy bird tracking data. This will allow us to predict when waterfowl will be where, in response to shortand long-term global environmental change. | Yali Si Qinchuan Xin Herbert H.T.Prins Willem F.de Boer Peng Gong | 2015 | Science Bulletin2015，60，23： | 6 |
| 9 | Type Synthesis of Lower Mobility Parallel Mechanisms: A Review显示文摘Type synthesis of mechanisms aims to systematically determine all possible structures for a specific mobility requirement. Numerous methods based on di erent theories were proposed for type synthesis of lower mobility parallel mechanisms in past decades. However, there does not exist a comprehensive review on these approaches. Therefore, the goal of this paper is to give such a review, classifying the approaches proposed in the literature into three groups, namely, motion-based methods, constraint-based methods, and other methods. The motion-based methods include the Lie group based method, the GF set method, the linear transformation method, the POC set method,and the finite screw method. The constraint-based methods involve the screw theory-based method, the virtual chain method, the method based on Grassmann line geometry and line graphs, and the motion constraint generator method. Other methods contain the enumeration approach based on the general CGK mobility formula and the graph theory method. Upon thoroughly analyzing the characteristics and/or limitations of each method, this review provides a well reference to help researchers find an e ective synthesis method for innovative design and further scientific investigations for mechanisms. | Wei Ye Qinchuan Li | 2019 | Chinese Journal of Mechanical Engineering2019，32，2： | 6 |
| 10 | Extraction of Astaxanthin from Euphausia pacific Using Subcritical 1,1,1,2-tetrafluoroethane显示文摘Euphausia pacific is an important source of natural astaxanthin.Studies were carried out to assess the extractability of astaxanthin from E.pacific using subcritical 1,1,1,2-tetrafluoroethane(R134a).To examine the effects of multiple process variables on the extraction yield,astaxanthin was extracted under various conditions of pressure(30-150 bar),temperature(303-343 K),time(10-50 min),flow rate(2-10 g min-1),moisture content(5.5%-63.61%),and particle size(0.25-0.109 mm).The results showed that the extraction yield increased with temperature,pressure,time and flow rate,but decreased with moisture content and particle size.A maximum yield of 87.74% was obtained under conditions of 100 bar,333 K,and 30 min with a flow rate of 6 g min-1 and a moisture content of 5.5%.The substantial astaxanthin yield obtained under low-pressure conditions demonstrates that subcritical R134a is a good alternative to CO 2 for extraction of astaxanthin from E.pacific. | HAN Yuqian MA Qinchuan WANG Lan XUE Changhu | 2012 | Journal of Ocean University of China2012，11，4： | 5 |
| 11 | Effects of PyC shell thickness on the microstructure,ablation resistance of SiCnws/PyC-C/C-ZrC-SiC composites显示文摘SiC nanowires/pyrocarbon(SiCnws/PyC)core-shell structure toughenedC/C-ZrC-SiC composites were fabricated by CLVD process,and the influences of PyC shell thickness on the microstructure and ablation resistance of the composites were researched.The results presented that SiCnws/PyC core-shell structure had a linear shape,and the composites became dense with the increasing PyC thickness.When the thickness of PyC shell increased from 0 to 2.4μm,the density and thermal conductivity of the composites was improved gradually,but the coefficient of thermal expansion(CTE)decreased firstly and then increased.After the ablation test for 90 s,the ablation rates of the composites decreased continuously as the PyC thickness increased from 0 to 1.4μm,but increased when the PyC thickness was up to 2.4μm.Especially when the PyC thickness was 1.4μm,the linear and mass ablation rates of the composites were 71.25%and 63.01%lower than those of the composites without PyC shell.The reasons behind the remarkable improvement of anti-ablation property were that the proper PyC thickness could alleviate the CTE mismatch to promote the formation of complete oxide coating,improve the thermal conductivity to reduce heat corrosion and enhance the capability to limit the mechanical erosion. | Qinchuan He Hejun Li Xuemin Yin Jinhua Lu | 2021 | Journal of Materials Science & Technology2021，，12： | 4 |
| 12 | FROM-GC: 30 m global cropland extent derived through multisource data integration显示文摘We report on a global cropland extent product at 30-m spatial resolution developed with two 30-m global land cover maps(i.e.FROM-GLC,Finer Resolution Observation and Monitoring,Global Land Cover;FROM-GLC=agg)and a 250-m cropland probability map.A common land cover validation sample database was used to determine optimal thresholds of cropland probability in different parts of the world to generate a cropland/noncropland mask according to the classification accuracies for cropland samples.A decision tree was then applied to combine two 250-m cropland masks:one existing mask from the literature and the other produced in this study,with the 30-m global land cover map FROM-GLC-agg.For the smallest difference with country-level cropland area in Food and Agriculture Organization Corporate Statistical(FAOSTAT)database,a final global cropland extent map was composited from the FROM-GLC,FROM-GLC-agg,and two masked crop=land layers.From this map FROM-GC(Global Cropland),we estimated the global cropland areas to be 1533.83 million hectares(Mha)in 2010,which is 6.95 Mha(0.45%)less than the area reported by the Food and Agriculture Organization(FAO)of the United Nations for the year 2010.A country-by=country comparison between the map and the FAOSTAT data showed a linear relationship(FROM-GC=1.05*FAOSTAT-1.2(Mha)with R^(2)=0.97).Africa,South America,Southeastern Asia,and Oceania are the regions with large discrepancies with the FAO survey. | Le Yu Jie Wang Nicholas Clinton Qinchuan Xin Liheng Zhong Yanlei Chen Peng Gong | 2013 | International Journal of Digital Earth2013，6，6： | 3 |
| 13 | Heterostructured CoFe@N-doped carbon porous polyhedron for efficient microwave absorption显示文摘The synthesis of wide bandwidth,thin thickness,and high performance microwave absorbing materials has become a hot topic of current research.Metal-organic frameworks with heterojunctions and porous structures are considered as suitable candidates to meet these characteristics.Herein,heterogeneous CoFe@N-doped porous carbon polyhedron composites were successfully synthesized via Fe^(2+)to replace Co in zeolite imidazole frame-67.The dielectric properties of composites were enhanced by the replacement of Fe^(2+),and the synergistic effect of dielectric loss and magnetic loss was realized.The petal-like lamellar structure increases the travel of electromagnetic(EM)waves,and the formation of porous structures improves impedance matching.Specifically,a reflection loss of−67.30 dB was obtained at a thickness of 2.88 mm,and an ultrabroad wide effective absorption bandwidth of 8.40 GHz was obtained,covering most of the X-band(8–12 GHz)and the whole Ku-band(12–18 GHz).The radar cross section(RCS)reduction value can reach 29.4 dB·m^(2),which means that the radar detector has a smaller probability of detecting targets.This work describes the unique advantages of metal ion replacement metal-organic frameworks derived materials in structural design,impedance matching,and performance adjustment,and provides a new reference for the field of electromagnetic wave absorption. | Dan Wu Yiqun Wang Shuanglin Deng Di Lan Zhongning Xiang Qinchuan He | 2023 | Nano Research2023，16，2： | 2 |
| 14 | Efficient microwave absorption achieved through in situ construction of core-shell Co Fe_(2)O_(4)@mesoporous carbon hollow spheres显示文摘Cobalt ferrite(CoFe_(2)O_(4)),with good chemical stability and magnetic loss,can be used to prepare composites with a unique structure and high absorption.In this study,CoFe_(2)O_(4)@mesoporous carbon hollow spheres(MCHS)with a core-shell structure were prepared by introducing CoFe_(2)O_(4)magnetic particles into hollow mesoporous carbon through a simple in situ method.Then,the microwave absorption performance of the CoFe_(2)O_(4)@MCHS composites was investigated.Magnetic and dielectric losses can be effectively coordinated by constructing the porous structure and adjusting the ratio of MCHS and CoFe_(2)O_(4).Results show that the impedance matching and absorption properties of the Co Fe_(2)O_(4)@MCHS composites can be altered by tweaking the mass ratio of MCHS and CoFe_(2)O_(4).The minimum reflection loss of the Co Fe_(2)O_(4)@MCHS composites reaches-29.7 dB at 5.8 GHz.In addition,the effective absorption bandwidth is 3.7 GHz,with the thickness being 2.5 mm.The boosted microwave absorption can be ascribed to the porous core-shell structure and introduction of magnetic particles.The coordination between the microporous morphology and the core-shell structure is conducive to improving the attenuation coefficient and achieving good impedance matching.The porous core-shell structure provides large solid-void and CoFe_(2)O_(4)-C interfaces to induce interfacial polarization and extend the electromagnetic waves’multiple scattering and reflection.Furthermore,natural resonance,exchange resonance,and eddy current loss work together for the magnetic loss.This method provides a practical solution to prepare core-shell structure microwave absorbents. | Lianggui Ren Yiqun Wang Xin Zhang Qinchuan He Guanglei Wu | 2023 | International Journal of Minerals,Metallurgy and Materials2023，30，3： | 2 |
| 15 | Lin28 promotes Her2 expression and Lin28/Her2 predicts poorer survival in gastric cancer显示文摘 | Qinchuan Wang Jichun Zhou Jufeng Guo Rongyue Teng Jianguo Shen Yasheng Huang Shuduo Xie Qun Wei Wenhe Zhao Wenjun Chen Xiaoming Yuan Yongxia Chen Linbo Wang | 2014 | Tumor Biology2014，，11： | 1 |
| 16 | Parasitic Motion Comparison of 3-PRS Paralle lmechanism with Dif- ferent Limb Arrangements 显示文摘 | LI Qinchuan CHEN Zhi CHEN Qiaohong | 2011 | Robotics and Computer-In- tegrated Manufacturing2011，27，： | 1 |
| 17 | Optimisation for subcritical fluid extraction of 17-methyltestosterone with 1,1,1,2-tetrafluoroethane for HPLC analysis显示文摘 | Yuqian Han Qinchuan Ma Jie Lu Yong Xue Changhu Xue | 2012 | Food Chemistry2012，，4： | 1 |
| 18 | General method for type synthesis of lower-mobility symmetrical parallel manipulators and several novel manipulators显示文摘 | HUANG Zhen LI Qinchuan | | 0，，02： | 1 |
| 19 | Type synthesis principle of minor-mobility parallel manipulators 显示文摘 | HUANG Zhen LI Qinchuan | 2002 | Science in China Series E2002，45，3： | 1 |
| 20 | Type synthesis of symmetrical lower-mobility parallel mechanisms using constraint-synthesis method显示文摘 | HUANG Zhen LI Qinchuan | 2003 | The International Journal of Robotics Research2003，22，1： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员