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20篇 您的检索式:作者名="Dengfeng Sun"
    题名 作者 年代 出处 被引量
1Atlas Based Kinematic Optimum Design of the Stewart Parallel Manipulator显示文摘Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators(more than three design parameters), such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace(SUW), primary kinematic performance indices of the Stewart manipulator, involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.SHAO Zhufeng TANG Xiaoqiang WANG Liping SUN Dengfeng 2015Chinese Journal of Mechanical Engineering2015,28,1:6
2Coupled trace element and SIMS sulfur isotope geochemistry of sedimentary pyrite:Implications on pyrite growth of Caixiashan Pb-Zn deposit显示文摘Colloform pyrite with core-rim texture is commonly deposited in carbonate platforms associated with the sulfide ores such as the Caixiashan Pb-Zn deposit.However,the genesis of colloform pyrite in Pb-Zn deposits,its growth controls and their geological implication are insufficiently understood.Integration of in-situ trace element and SIMS sulfur isotopes has revealed geochemical variations among these pyrite layers.These colloform pyrite occur as residual phases of core-rim aggregates,the cores are made up of very fine-grained anhedral pyrite particles,with some rims being made up of fine-grained and poorlycrystallized pyrite,while the other rims were featured with euhedral cubic pyrite.which are cemented by fine-grained calcite and/or dolomite with minor quartz.Sulfur isotope analysis shows that some wellpreserved rims have negative δ^34 S values(-28.12‰to-0.49‰),whereas most of the cores and rims have positive δ^34 S values(>0 to+44.28‰;peak at+14.91‰).Integrating with the methane and sulfate were observed in previous fluid inclusion study,we suggest that the 34 S depleted rims were initially formed by bacteria sulfate reduction(BSR),whereas the positive δ^34 S values were resulted from the sulfate reduction driven by anaerobic methane oxidation(AOM).The well-developed authigenic pyrite and calcite may also support the reaction of AOM.Combined with petrographic observations,trace element composition of the colloform pyrite reveals the incorporation and precipitation behavior of those high abundance elements in the pyrite:Pb and Zn were present as mineral inclusion and likely precipitated before Fe,as supported by the time-resolved Pb-Zn signal spikes in most of the analyzed pyrite grains.Other metals,such as Hg,Co and Ni,may have migrated as chloride complexes and entered the pyrite lattice.Arsenic and Sb,generally influenced by complex-forming reactions rather than substitution ones,could also enter the pyrite lattice,or slightly predate the precipitation of colloform pyrite as mineral inclusions,which are controlled by their hydrolysis constant in the ore fluids.The colloform pyrite may have grown inward from the rims.The successive BSR reaction process would enrich H^32/2S in the overlying water column but reduce the metal content,the nucleation of these pyrite rims was featured by strongly negative sulfur isotopes.The following AOM process should be activated by deformation like the turbidity sediment of the mudstone as the sulfide deposition are associated with fault activities that caused the emission of methane migration upward and simultaneously replenishing the metal in the column.The higher AOM reaction rate and the higher metal supply(not only Fe.but with minor other metals such as Pb and Zn) caused by sediment movement enhanced the metal concentration within the pyrite lattice.Dengfeng Li Huayong Chen Xiaoming Sun Yu Fu Qiaofen Liu Xiaoping Xia Qing Yang 2019Geoscience Frontiers2019,10,6:4
3Hydrothermal synthesis of monodisperse α-Fe_2O_3 hexagonal platelets显示文摘Uniformly sized α-Fe2O3 hexagonal platelets were synthesized by a hydrothermal process using Fe(OH)3 suspension and large amount of NaOH.The reaction products were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),selected area electron diffraction(SAED),and a vibrating sample magnetometer(VSM).The results show that the hexagonal platelets are fine,monodisperse and consisting of single-crystals.The magnetic hysteresis(M-H) curve of the samples measured at room temperature indicates that the α-Fe2O3 micro-platelets exhibit ferromagnetic behaviors with relatively low coercivity.Dengfeng Peng Sadeh Beysen Qiang Li Yanfei Sun Linyu Yang 2010Particuology2010,8,4:4
4Red emission in Pr doped CaBi4Ti4 O15 ferroeleetric ceramics 显示文摘Peng Dengfeng Sun Haiqin Wang Xusheng 2011Materials Science and Engineering B2011,176,18:1
5Serum level of galectin-3 and its clinical significance in patients with chronic Keshan disease显示文摘Objective: Keshan disease (KD) is a fatal endemic dilated cardiomyopathy with unclear etiology and pathogenesis, and a high mortality in China. Pathologic studies confirmed that different degree of myocardial fibrosis existed in various types of KD. Myocardial fibrosis is an important contributor to the pathophysiology of left ventricular remodeling. Recently, galectin-3 (Gal-3) as a marker of cardiac fibrosis and heart failure was approved by the US FDA. The aim of this study was to evaluate the changes of serum level of Gal-3 in chronic KD (CKD) and their clinical implications. Methods: The levels of serum Gal-3 were measured by using enzyme-linked immunosorbent assay (ELISA) in 37 CKD patients and 32 healthy controls. Echocardiography was used to determine parameter of left ventricular ejection fraction (LVEF) and left ventricular end-diastolic dimension (LVEDD). Results: The serum concentration of Gal-3 ([95.81±18.99] ng/ml versus [48.16±11.09] ng/ml, t=6.906, P<0.001) and LVEDD ([60.46±7.63] mm versus (42.69±10.66) mm, t=3.61, P<0.01) were significantly higher, while LVEF ([42.69±10.66]% versus [62.16±6.38]%, t=4.679, P<0.01) were significantly lower in CKD patients compared with healthy controls. A negative correlation was found between elevated Gal-3 and lower LVEF (r=-0.882, P<0.001) and a positive correlation was found between elevated Gal-3 levels and enlarged LVEDD (r=0.834, P<0.001) or higher NYHA class (r=0.854, P<0.01) in CKD patients. Conclusion: Serum concentration of Gal-3 is strongly correlated with poorer left ventricular systolic function, enlarged LVEDD and higher New York Heart Association (NYHA) class, which may provide indirectly diagnostic information on myocardial fibrosis and heart function in CKD patients.SUN Yuxiao LIU Xin GAO Dengfeng DONG Xin ZHU Canzhan HAN Zhenhua YUAN Yiqiang ZHU Yanhe NIU Xiaolin 2013Journal of Medical Colleges of PLA(China)2013,28,3:1
6Inflammatory angiomyolipomas of the liver: a clinicopathologic and immunohistochemical analysis of 5 cases显示文摘Huaiyin Shi Dengfeng Cao Lixin Wei Lu Sun Aitao Guo 2010Annals of Diagnostic Pathology2010,,4:1
7Different n-6/n-3 polyunsaturated fatty acid ratios affect postprandial metabolism in normal and hypertriglyceridemic rats显示文摘Postprandial metabolism plays major roles in many pathological conditions.The n-6/n-3 polyunsaturated fatty acid(PUFA)ratio is closely related to various physiological disorders.This study aimed to investigate the effects of high fat meals with different n-6/n-3 PUFA ratios on postprandial metabolism in normal control(NC)and hypertriglyceridemia(HTG)rats.The postprandial response of triglyceride(TG)in HTG groups was higher than that in NC groups after different n-6/n-3 PUFA ratio meals.The HTG groups showed higher postprandial total cholesterol(TC)responses than NC groups after 1:1 and 20:1 ratio meals.The 5:1 n-6/n-3 PUFA ratio elicited lower postprandial responses of tumor necrosis factorα(TNF-α)than 1:1 and 10:1 ratios in HTG groups.The postprandial malondialdehyde(MDA)response was lower after a 5:1 n-6/n-3 PUFA ratio meal than 1:1 and 20:1 ratio meals in HTG groups.The 1:1 ratio resulted in a lower postprandial reactive oxygen species(ROS)level than 5:1 and 10:1 n-6/n-3 PUFA ratios in NC groups.The results showed that a low n-6/n-3 PUFA ratio improved postprandial dysmetabolism induced by a high fat meal in NC and HTG rats.A high n-6/n-3 PUFA ratio increased the difference in postprandial metabolism between NC and HTG rats.Ligang Yang Chao Yang Zhixiu Song Min Wan Hui Xia Xian Yang Dengfeng Xu Da Pan Hechun Liu Shaokang Wang Guiju Sun 2023Food Science and Human Wellness2023,12,4:1
8Blue excited photoluminescence of Pr doped CaBi 2 Ta 2 O 9 based ferroelectrics显示文摘Dengfeng Peng Haiqin Sun Xusheng Wang Juncheng Zhang Mianmian Tang Xi Yao 2011Journal of Alloys and Compounds2011,,1:1
9Primary choriocarcinoma of the liver: a clinicopathological study of five cases in males显示文摘Huaiyin Shi Dengfeng Cao Lixin Wei Lu Sun Aitao Guo 2010Virchows Archiv2010,,1:1
10Interface synergistic effects induced multi-mode luminescence显示文摘Mechanoluminescence(ML)has become the most promising material for broad applications in display and sensing devices,in which ZnS is the most commonly studied one due to its stable and highly repetitive ML performances.In this work,we have successfully prepared the biphase ZnS on a large scale through the facile in-air molten salt protection strategy.The obtained biphase has the best ML properties,which is mainly attributed to the synergistic effects of piezo-photonic,defect,and interface dislocations.DFT calculations have confirmed that the defects activate the local S and Zn sites and reduce the energy barrier for electron transfer.The much stronger X-ray induced luminescence than the commercial scintillator is also reached.The application of ZnS particles in both papers and inks delivers superior performance.Meanwhile,ZnS particles based screen printing ink is able to directly print on paper,plastic and other carriers to form clear marks.These proposed paper and ink hold great potentials in applications of information security and anti-counterfeiting based on the multi-mode luminescence properties.This work provides a new avenue to understand and realize the high-performance multi-mode luminescence,inspiring more future works to extend on other ML materials and boosting their practical applications.Ronghua Ma Chunfeng Wang Wei Yan Mingzi Sun Jianxiong Zhao Yuantian Zheng Xu Li Longbiao Huang Bing Chen Feng Wang Bolong Huang Dengfeng Peng 2022Nano Research2022,15,5:1
11Routing Flexible Traffic into Metroplex显示文摘Peng Wei Jit-Tat Chen Dominick Andri- sani Dengfeng Sun 2011AIAA Guidance Navigation and Con- trol Conference 08 - 11 August 2011 Portland2011,,:1
12Studies on rickettsia-like organism (RLO) disease of tropical marine pearl oyster-Epidemiological investigation of RLO disease in juvenile populations of maricultured Pinctada maxima显示文摘The death which occurred in juvenile population was a severe problem in the course ofPinctada maxima artificial culture. With the methods of field investigation, histological study andstatistic analyses, the epidemiological study was carried out on the disease and death in juvenile popula-tions of Pinctada maxima in the Xinying Pearl Oyster Mariculture Farm of Lingao County (for the A,B and C batches of cultured juveniles hanged in the sea) and the Xincun Pearl Oyster Mariculture Farmof Lingshui County (for the D batch of cultured juvenile hanged in the pond), Hainan Province fromNovember 1993 to April 1995. The results show that the deaths which occurred in juvenile populations of Pinctada maxima pre-sented an outbreak pattern. The peak of mortality rates, in general, occurred in 4-to 6-month old pearloyster juveniles, and the mortality rates gradully declined with the extention of pearl oyster age after cul-turing 8 months. The correlation between the mortality rates of juvenile populations and mean bodylengths of juvenile populations show that the mortality rate become higher under 4 cm of mean bodylengths of juvenile population and become obvious declined over 5 cm of mean body lengths. The peak ofmortality rate occurred in 1 ~3 cm of mean body lengths. The results of histological observation showedthat rickettsia-like organism inclusions were common, histological widespread infective agent among ev-ery batches (A, B, C and D) of cultured juvenile populations. The mean severity indices (SI) of rick-ettsia-like organism (RLO) infection were positively correlated with mortality rates of juvenile popula-tions. After or within every peaks of RLO infection were all accompanied with the peaks of mortalityrates of host populations and the mortality rates declined with decreased RLO infection. So the evidencesof histological observation and epidemiology in this study indicated that rickettsia-like organism (RLO)may be as an important pathogenic organism of disease and death of cultured Pinctada maxima. In addi-tion, a few ciliates were discovered only in part of batch A of cultured juvenile population. The mortalityrates in juvenile populations were not correlated with the weekly mean temperature and salinity of seawater.Xinzhong Wu , Dengfeng Li, Jinpei Pan, Jingbo Jiang College of Animal Sciences,Zhejiang University,Hangzhou 310029,China. Email: wuxz@zju.edu.cnSouth China Sea Institute of Oceanology, Chinese Academy of Sciences,Guangzhou 510301,ChinaSchool of Life Sciences,SUN YAT-SEN University,Guangzhou 510275,China 2003Acta Oceanologica Sinica2003,22,3:1
13Characteristic control of long period fiber grating (LPFG) fabricated by infrared femtosecond laser显示文摘长时期纤维栅栏(LPFG ) 与不同光谱特征与 1 kHz 被制作, 50 fs 激光脉搏。反响的拒绝乐队的对比能被轴的应力的合适的数量显著地在激光与更低的精力密度激光照耀写或 processing 以后期间沿着纤维增加。焦点的状况,激光照耀的脉搏精力和栅栏时期的数字的变化导致 LPFG 的回声拒绝乐队的产生从对加更大的 out-of-band 损失的多山峰单个山峰。out-of-band 损失被从处理的激光散布的 Mie 首先引起引用,并且它能被减少减少栅栏沥青的责任周期而不是在激光照耀的实际力量下面的 lowing。Xiaoyan SUN Peng HUANG Jiefeng ZHAO Li WEI Nan ZHANG Dengfeng KUANG Xiaonong ZHU 2012Frontiers of Optoelectronics2012,5,3:1
14Muscle-inspired soft robots based on bilateral dielectric elastomer actuators显示文摘Muscle groups perform their functions in the human body via bilateral muscle actuation,which brings bionic inspiration to artificial robot design.Building soft robotic systems with artificial muscles and multiple control dimensions could be an effective means to develop highly controllable soft robots.Here,we report a bilateral actuator with a bilateral deformation function similar to that of a muscle group that can be used for soft robots.To construct this bilateral actuator,a low-cost VHB 4910 dielectric elastomer was selected as the artificial muscle,and polymer films manufactured with specific shapes served as the actuator frame.By end-to-end connecting these bilateral actuators,a gear-shaped 3D soft robot with diverse motion capabilities could be developed,benefiting from adjustable actuation combinations.Lying on the ground with all feet on the ground,a crawling soft robot with dexterous movement along multiple directions was realized.Moreover,the directional steering was instantaneous and efficient.With two feet standing on the ground,it also acted as a rolling soft robot that can achieve bidirectional rolling motion and climbing motion on a 2°slope.Finally,inspired by the orbicularis oris muscle in the mouth,a mouthlike soft robot that could bite and grab objects 5.3 times of its body weight was demonstrated.The bidirectional function of a single actuator and the various combination modes among multiple actuators together allow the soft robots to exhibit diverse functionalities and flexibility,which provides a very valuable reference for the design of highly controllable soft robots.Yale Yang Dengfeng Li Yanhua Sun Mengge Wu Jingyou Su Ying Li Xinge Yu Lu Li Junsheng Yu 2023Microsystems & Nanoengineering2023,9,5:0
15BINARY SEQUENCE WITH PERFECT SPREADING STAIRCASE PROFILE OF LINEAR COMPLEXITY显示文摘This paper makes the following investigations.1. To solve the second open problem proposed by M.Morii and M.Kasahar[1];2. To prove the nonexistence of PSSP sequence with the smallest(or biggest) density;3. To find the PSSP sequence with (complementary) Hamming weight m for every positive integer m;4. To propose a generalization form of the known IYM sequence.YANG Yi-clan SUN Dengfeng (Department of Information Engineering, Beijing University of Posts & Telecommunications, Be iiing 100088 China) 1997Systems Science and Mathematical Sciences1997,10,1:0
16Coffee Flower Identification Using Binarization Algorithm Based on Convolutional Neural Network for Digital Images显示文摘Crop-type identification is one of the most significant applications of agricultural remote sensing,and it is important for yield estimation prediction and field management.At present,crop identification using datasets from unmanned aerial vehicle(UAV)and satellite platforms have achieved state-of-the-art performances.However,accurate monitoring of small plants,such as the coffee flower,cannot be achieved using datasets from these platforms.With the development of time-lapse image acquisition technology based on ground-based remote sensing,a large number of small-scale plantation datasets with high spatial-temporal resolution are being generated,which can provide great opportunities for small target monitoring of a specific region.The main contribution of this paper is to combine the binarization algorithm based on OTSU and the convolutional neural network(CNN)model to improve coffee flower identification accuracy using the time-lapse images(i.e.,digital images).A certain number of positive and negative samples are selected from the original digital images for the network model training.Then,the pretrained network model is initialized using the VGGNet and trained using the constructed training datasets.Based on the well-trained CNN model,the coffee flower is initially extracted,and its boundary information can be further optimized by using the extracted coffee flower result of the binarization algorithm.Based on the digital images with different depression angles and illumination conditions,the performance of the proposed method is investigated by comparison of the performances of support vector machine(SVM)and CNN model.Hence,the experimental results show that the proposed method has the ability to improve coffee flower classification accuracy.The results of the image with a 52.5°angle of depression under soft lighting conditions are the highest,and the corresponding Dice(F1)and intersection over union(IoU)have reached 0.80 and 0.67,respectively.Pengliang Wei Ting Jiang Huaiyue Peng Hongwei Jin Han Sun Dengfeng Chai Jingfeng Huang 2020Plant Phenomics2020,2,1:0
17Origami-inspired folding assembly of dielectric elastomers for programmable soft robots显示文摘Origami has become an optimal methodological choice for creating complex three-dimensional(3D)structures and soft robots.The simple and low-cost origami-inspired folding assembly provides a new method for developing 3D soft robots,which is ideal for future intelligent robotic systems.Here,we present a series of materials,structural designs,and fabrication methods for developing independent,electrically controlled origami 3D soft robots for walking and soft manipulators.The 3D soft robots are based on soft actuators,which are multilayer structures with a dielectric elastomer(DE)film as the deformation layer and a laser-cut PET film as the supporting flexible frame.The triangular and rectangular design of the soft actuators allows them to be easily assembled into crawling soft robots and pyramidal-and square-shaped 3D structures.The crawling robot exhibits very stable crawling behaviors and can carry loads while walking.Inspired by origami folding,the pyramidal and square-shaped 3D soft robots exhibit programmable out-of-plane deformations and easy switching between two-dimensional(2D)and 3D structures.The electrically controllable origami deformation allows the 3D soft robots to be used as soft manipulators for grasping and precisely locking 3D objects.This work proves that origami-inspired fold-based assembly of DE actuators is a good reference for the development of soft actuators and future intelligent multifunctional soft robots.Yanhua Sun Dengfeng Li Mengge Wu Yale Yang Jingyou Su Tszhung Wong Kangming Xu Ying Li Lu Li Xinge Yu Junsheng Yu 2022Microsystems & Nanoengineering2022,8,2:0
18Multidisciplinary team for the diagnosis and treatment of 2cases of primary intestinal yolk sac tumor显示文摘Extragonadal primary yolk sac tumor of the intestinal tract origin is exceedingly rare. Through a multiple disciplinary team, the diagnosis and treatment of primary intestinal yolk sac tumor were further defined. We report 2 such cases with detailed histologic and immunohistochemical analysis. The two patients were a 7-year-old girl and a 29-year-old woman. Both of them preoperatively had an elevated serum alpha fetoprotein(AFP) level(≥ 1,210 ng/mL). The tumors are located in the intestine and imaging examination indicated the rectum as the primary site. Grossly the mass was grey-white and crisp texture. Microscopic examination featured reticular, microcystic, macrocystic, papillary, solid, and some glandular patterns. Immunohistochemically,tumor cells of both cases were positive for SALL4, AFP, pan-cytokeratin(AE1/AE3), and glypican-3. Simultaneously, a stain for EMA, OCT4, CD30, HCG, vimentin and CK20 were negative in all 2 neoplasms. The features of morphology,immunohistochemistry, laboratory examinations and imaging studies consist of the diagnosis of primary yolk sac tumor of the intestine.Qiujuan Huang Changxu Liu Ruijun Tang Jie Li Wei Li Lei Zhu Yuhong Guo Lin Zhang Tongyuan Qu Lingyi Yang Lingmei Li Yalei Wang Baocun Sun Bin Meng Jie Yan Wengui Xu Huilai Zhang Dengfeng Cao Wenfeng Cao 2018Cancer Biology & Medicine2018,15,4:0
19Density Functional Theory Study of Marine Polybrominated Diphenyl Ethers in Anaerobic Degradation显示文摘Polybrominated diphenyl ethers(PBDEs)are a kind of serious pollutants in the ocean.Biodegradation is considered as an economical and safe way for PBDEs removal and reductive debromination dominates the initial pathway of anaerobic degradation.On the basis of experimental study,Octa-BDE 197,Hepta-BDE 183,Hexa-BDE 153,Penta-BDE 99 and Tetra-BDE 47 were selected as the initial degradation objects,and their debromination degradation were studied using density functional theory.The structures were optimized by Gaussian 09 program.Furthermore,the molecular orbitals and charge distribution were analyzed.All C-Br bond dissociation energies at different positions including ortho,meta and para bromine atoms were calculated and the sequence of debromination was obtained.There is a close relationship between molecular structure,charge,molecular orbital and C-Br bond.All PBDEs exhibited similar debromination pathways with preferential removal of meta and para bromines.XU Xiang MAN Miaomiao SUN Qinxing LIU Qingzhi WU Kechen YANG Dengfeng 2023Journal of Ocean University of China2023,22,5:0
20A prokaryotic mycoplasma-like organism infection in the scallop Argopecten irradians显示文摘Intracytoplasmic infection with a prokaryotic mycoplasma-like organism (MLO) were characterized in the scallop Argopecten irradians, and the first report of such infection in this scallop was represented. Ultrastructurally these microorganisms are usually pleomorphic and variable in morphology and size, and appear in several cell types such as small spherical body, rod-shaped bodies and longer filament-shaped body. They lack a cell wall. These observations revealed that these types of the prokaryote showed some characteristics of a mycoplasma-like organism (MLO). MLO reproduced in two ways: binary fission and budding. The results of isolation and purification showed that a large number of MLOs existed in the tissues of diseased scallops. The results of experimental infection revealed that the MLO is pathogenic to the scallop Argopecten irradians.ZHANG Weizhu WU Xinzhong SUN Jingfeng LI Dengfeng 2007Acta Oceanologica Sinica2007,26,2:0
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