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Functional Morphology and Bending Characteristics of the Honeybee Forewing

Journal of Bionic Engineering 2017年第1期14卷 111-118页

作者： yun Ma Huilan ren Jianguo Ning Pengfei Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

The present work aimed to reveal the functional morphology and bending characteristics of the worker honeybee （Apis mellifera） forewing. Honeybee wings including the forewing and hindwing, which are mainly composed of veins and membranes, are a kind of typical hierarchical biomaterials. We investigated the cross-sections of membranes, veins and wing hairs through Scanning Electron Microscopy （SEM）. Based on the microscopic observation, it was found that the vein is a thick-walled cylinder, and the membrane possesses multilayered structure and so does the wing hair which shows the thread surface. At the vein-membrane conjunctive position, membranes and veins are assembled seamlessly and veins are packed smoothly and tightly by membranes into a whole, allowing honeybees to perform excellent flapping flight. In such a case, we also conducted the cantilevered bending experiment of honeybee forewing to explore their bending characteristics using a MTS Tytron 250 micro force tester. Experiment results indicate that the anti-bending capacity of the forewing along the spanwise direction is higher than that along the chordwise direction which is partly caused by the wing corrugation along the wing span detected by the micro-Computed Tomography （micro-CT）, and ventral load bearing ability is better than dorsal one along the spanwise and chordwise direction of the wing which is due to the stress-stiffening of membranes. It could be concluded that the structural configuration of the wing is closely relevant to wing biomechanical behaviors. All results above would provide a significant support for the design of bioinspired wings for Flapping Micro Aerial Vehicles （FMAV）.

关键词： honeybee forewing functional morphology hierarchical structure bending stiffness

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The optimal information rate for graph access structures of nine participants

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Frontiers of Computer Science 2015年第5期9卷 778-787页

作者： yun SONG Zhihui LI Yongming LI ren XIN College of Mathematics and Information Science Shaanxi Normal University Xi'an 710062 China College of Computer Science Shaanxi Normal University Xi'an 710062 China School of Civil Engineering Xi'an University of Architecture and Technology Xi'an 710055 China

The information rate is an important metric of the performance of a secret-sharing scheme. In this paper we consider 272 non-isomorphic connected graph access structures with nine vertices and eight or nine edges, and either determine or bound the optimal information rate in each case. We obtain exact values for the optimal information rate for 231 cases and present a method that is able to derive information-theoretical upper bounds on the optimal information rate. Moreover, we apply some of the constructions to determine lower bounds on the information rate. Regarding information rate, we conclude with a full listing of the known optimal information rate （or bounds on the optimal information rate） for all 272 graphs access structures of nine participants.

关键词： optimal information rate perfect secret-sharingscheme entropy method graph access structure splittingconstruction L-decomposition weighted decomposition

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PhI(OAc)2-promoted umpolung acetoxylation of enamides for the synthesis of α-acetoxy ketones

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Science China Chemistry 2017年第6期60卷 761-768页

作者： Ming Chen Wei Zhang Zhi-Hui ren Wen-yun Gao Yao-Yu wang Zheng-Hui Guan Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education Department of Chemistry & Materials Science Northwest University Xi'an 710127 China College of Life Sciences/National Engineering Research Center for Miniaturized Detection Systems Northwest University Xi 'an 710069 China

Umpolung is a fundamental concept in organic chemistry, which provides an alternative strategy for the synthesis of target compounds which were not easily accessible by conventional methods. Herein, a mild and efficient PhI(OAc)_2-promoted umpolung acetoxylation reactions of enamides was developed for the synthesis of α-acetoxy ketones. The reaction tolerates a wide range of functional groups and affords α-acetoxy ketones in good to excellent yields. PhI(OAc)_2 serves as a source of acetoxy in the reaction.

关键词： umpolung enamides acetoxylation hypervalent iodine reagents α-acetoxy ketones

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The effect of impeller slot jet on centrifugal pump performance

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Journal of Hydrodynamics 2019年第4期31卷 733-739页

作者： ren-hui Zhang Li-chen yun Jing Li School of Energy and Power Engineering Lanzhou University of Technology Lanzhou 730050China China Key Laboratory of Fluid Machinery and Systems Lanzhou University of Technology Lanzhou 730050 China

To improve the cavitation performance of the centrifugal pump, a new kind of centrifugal pump impeller with slot is proposed. The slot is on the impeller shroud near the suction side of the blade leading edge. So, the fluid with high energy in the impeller front side chamber is drained to the lowest pressure area. The jet flow would compensate the blade inlet flow with a certain energy. With numerical simulations, the pump's inner flows for 5 different slot sizes and their hydraulic performances are compared with those of the prototype pump. The slot jet would result in the increase of the impeller flow rate and the volute area ratio, leading to the head decrease within the whole flow rate range. The slot jet can suppress the reverse flow remarkably at a low flow rate, and the pump efficiency is improved. The slot jet improves the pump cavitation performance effectively, especially at a low flow rate. To some extent, the smaller the slot size is, the better the pump cavitation performance is. The cavitation performance of the slot impeller with a size of 2 mmx 1.75 mm is much better than that of the prototype impeller. Compared with the prototype impeller, the lowest pressure near the slot impeller blade inlet and even the pressure in all forepart regions are improved significantly. The slot impeller is shown to be effective in suppressing the cavitation, and the available net positive suction head is improved.

关键词： Centrifugal pump slot impeller slot jet cavitation performance circulation flow

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RESEARCH OF INNER FLOW IN A DOUBLE BLADES PUMP BASED ON OPENFOAM

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Journal of Hydrodynamics 2012年第2期24卷 226-234页

作者： LIU Hou-lin ren yun wang Kai WU Deng-hao RU Wei-min TAN Ming-gao Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhengjiang 212013China

The inner flow analysis of centrifugal pumps has gradually become an important issue for the hydraulic design and performance ***,CFD simulation toolbox of pump inner flow mainly contains commercial tools and open source *** are some defects for commercial CFD software for the numerical simulation of 3-D turbulent internal flow in pump,especially in capturing the flow characteristics under the off-design operating ***,it is difficult for researchers to do further investigation because of the undeclared ***,an open source software like Open Field Operation and Manipulation （OpenFOAM） is increasingly popular with researchers from all over the *** this paper,a new computational study was implemented based on the original solver and was used to directly simulate the steady-state inner flow in a double blades pump,with the specific speed is *** order to disclose the characteristics deeply,three research schemes were *** ratios （） of the flow rate are 0.8,1.0 and 1.2,*** simulation results were verified with the Particle Imaging Velocimetry （PIV） experimental results,and the numerical calculation results agree well with the experimental ***,the phenomena of flow separation under the off-design operating conditions are well captured by *** results indicate that OpenFOAM possesses obvious strong predominance in computing the internal flow field of *** analysis results can also be used as the basis for the further research and the improvement of centrifugal pump.

关键词： numerical simulation double blades pump internal flow Particle Imaging Velocimetry (PIV)

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Effects of magnetic fields on Fe–Si composite electrodeposition

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International Journal of Minerals,Metallurgy and Materials 2014年第12期21卷 1175-1186页

作者： Qiong Long yun-bo Zhong Huai wang Tian-xiang Zheng Jun-feng Zhou Zhong-ming ren Shanghai Key Laboratory of Modern Metallurgy and Material Processing Shanghai University

Coatings containing Fe-Si particles were electrodeposited on 3.0wt% Si steel sheets under magnetic fields. The effects of magnetic flux density （MFD）, electrode arrangement and current density on the surface morphology, the silicon content in the coatings and the cathode current efficiency were investigated. When a magnetic field was applied parallel to the current and when the MFD was less than 0.5 T, numerous needle-like structures appeared on the coating surface. With increasing MFD, the needle-like structures weakened and were transformed into dome-shaped structures. Meanwhile, compared to results obtained in the absence of a magnetic field, the silicon content in the coatings significantly increased as the MFD was increased for all of the samples obtained using a vertical electrode system. However, in the case of an aclinic electrode system, the silicon content decreased. Furthermore, the cathode current efficiency was considerably diminished when a magnetic field was applied. A possible mechanism for these phenomena was discussed.

关键词： composite coatings electrodeposition silicon steel magnetic field surface morphology silicon content magnetohydrodynamics

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NUMERICAL SIMULATION OF UNSTEADY FLOW FOR VISCO- ELASTIC FLUID IN AN ECCENTRIC ANNULUS WITH INNER ROD RECIPROCATION

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Journal of Hydrodynamics 2008年第2期20卷 261-266页

作者： HE Feng-yun YANG Shu-ren Department of Petroleum Engineering Daqing Petroleum Institute Daqing 163318 China

The equation governing the unsteady flow of viscoelastic fluids in an eccentric annulus was derived by using the common conversion Maxwell fluid constitutive equation and then discretized by the control volume method. The velocity distribution of flow field was computed by using the ADI method. The influences of the pressure gradient, eccentricity, stroke length, and stroke frequency on the velocity and flow capacity in the flow field was analyzed. The foundation for further research of the eccentric wear problem of the pumping rod in polymer-flood well was laid.

关键词： polymer-flood well viscoelastic fluid eccentric annulus unsteady flow eccentric wear

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Study on HOBEM Based on Analytical Panel Integrals Related to Translating-Pulsating Source for Hydrodynamic Responses of Vessels Sailing in Waves

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China Ocean Engineering 2022年第3期36卷 348-362页

作者： YANG yun-tao ZHU ren-chuan LI Yu-long School of Naval Architecture and Civil Engineering Jiangsu University of Science and TechnologyZhangjiagang 215600China State Key Laboratory of Ocean Engineering Collaborative Innovation Center for Advanced Ship and Deep-Sea ExplorationSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Technology Centre for Offshore and Marine Singapore(TCOMS)Singapore

A higher-order boundary element method(HOBEM)incorporated with analytical panel integrals related to translat-ing-pulsating source Green’s function is proposed for the hydrodynamic response prediction of ships advancing in *** this method,the 9-node bi-quadratic curvilinear elements employed to discretize the mixed-source/dipole boundary integral equation are mapped into the parametric plane through a coordinate *** in order to ease the numerical instability problem,a novel analytical quadrature is derived to calculate the influence coefficients by changing the integral order and using integration by *** singularity caused by infinite discontinuity is analyzed and eliminated by adopting some mathematical *** the calculations of panel integrals of Green’s function and its x-derivative,the analytical integral method is proved to be always accurate even for field points approaching the free surface,where numerical quadrature is impossible to give reasonable *** on this,a higher-order seakeeping program is developed and applied in the motion response prediction of two different types of ships(i.e.,a wall-sided ship Wigley III and a non-wall-sided ship S175).By comparing the computed results with the corresponding experimental data and numerical solutions of the translating-pulsating and higher-order Green’s function methods based on traditional Gauss quadrature,it is found that the HOBEM based on analytical quadrature is of better accuracy and *** the non-wall-sided ship,only the present method can produce reasonable pre-diction of motion responses,while obvious oscillatory phenomenon is observed in the results of the other two numerical methods based on Gauss quadrature.

关键词： HOBEM translating-pulsating Green’s function analytical quadrature seakeeping forward speed

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Down regulation of UCP2 expression in retinal pigment epithelium cells under oxidative stress: an in vitro study

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International Journal of Ophthalmology(English edition) 2019年第7期12卷 1089-1094页

作者： Ying Liu Yuan ren Xia wang Xu Liu yun Xu Yuan He Department of Ophthalmology the Second Affiliated Hospital of Xi’an Medical UniversityOcular Immunology and Inflammation InstituteShaanxi Provincial Clinical Research Center for Ophthalmology

AIM: To evaluate the expression of uncoupling protein 2(UCP2) in a retinal pigment epithelium cell line(ARPE-19), under oxidative stress(OS).METHODS: ARPE-19 cells were divided into groups treated with various concentrations of hydrogen peroxide(H2 O2;0, 150, 300, 500, 700, and 900 μmol/L) for 24 h, to induce oxidative damage and cell viability was assessed by MTT assay. UCP2 mRNA expression in cells treated with H2 O2 was investigated by reverse transcription-polymerase chain reaction(RT-PCR). UCP2 protein expression was assessed by Western blotting and ROS levels analyzed by flow cytometry(FCM). Further, UCP2-siRNA treated cultures were exposed to H2 O2(0, 75, 150, and 300 μmol/L) for 2 h and cell viability determined by MTT ***: Cells treated with higher concentrations of H2 O2 appeared shrunken;their adhesion to adjacent cells was disrupted, and the number of dead cells increased. The results of cell viability assays demonstrated that the numbers of cells were decreased in a dose-dependent manner following treatment with H2 O2. Compared with untreated controls, cell viability was significantly reduced after treatment with >300 μmol/L H2 O2(P<0.05). Cell metabolic activity was decreased with increased concentrations of H2 O2 as detected by MTT assay. Levels of OS were further decreased in cells treated with UCP2-siRNA compared with those treated with H2 O2 alone(P<0.05). The results of RT-PCR and Western blotting demonstrated that UCP2 expression was reduced in H2 O2-treated groups compared with controls(P<0.05). FCM analysis showed that cell reactive oxygen species(ROS) levels were increased in H2 O2-treated groups and further upregulated by UCP2-si RNA treatment(P<0.05).CONCLUSION: Expression levels of UCP2 are decreased in ARPE-19 cells treated with H2 O2. ROS levels are further increased in cells treated with UCP2-siRNA relative to those treated with H2 O2 alone. UCP2 may have a protective role in ARPE-19 cells during oxidative injury.

关键词： uncoupling protein 2 retinal pigment epithelium cells oxidative stress

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白脉软膏与巴氯芬治疗脑卒中患者肌痉挛的疗效比较

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中国基层医药 2016年第20期23卷 3076-3079页

作者：李亮陶林花施明任芸尹汉逵王月丽孙燕林斯捷嘉兴市第二医院康复医学中心浙江省嘉兴314000

目的：比较白脉软膏与巴氯芬改善脑卒中患者肌痉挛的疗效。方法将84例伴有肢体痉挛的脑卒中患者按数字表法随机分为白脉软膏组和巴氯芬组，每组42例，白脉软膏组予痉挛肢体外用白脉软膏，巴氯芬组予口服巴氯芬片30～75 mg／d，两组连续... 详细信息

目的：比较白脉软膏与巴氯芬改善脑卒中患者肌痉挛的疗效。方法将84例伴有肢体痉挛的脑卒中患者按数字表法随机分为白脉软膏组和巴氯芬组，每组42例，白脉软膏组予痉挛肢体外用白脉软膏，巴氯芬组予口服巴氯芬片30～75 mg／d，两组连续用药2周、4周、8周后比较两组患者治疗前后的疗效。结果两组治疗前后的痉挛水平、疼痛水平及日常生活能力差异均有统计学意义，且白脉软膏组治疗后痉挛水平低于巴氯芬组[白脉软膏组在治疗4周、8周后 Ashworth 评分分别为（1．59±0．46）分、（0．89±0．56）分，巴氯芬组在治疗4周、8周后 Ashworth 评分分别为（1．75±0．64）分、（1．45±0．48）分，白脉软膏组 Ashworth 评分明显低于巴氯芬组，差异均有统计学意义（t ＝2．916、3．367，均 P ＜0．05）]，白脉软膏组治疗后疼痛水平低于巴氯芬组[白脉软膏组在治疗2周、4周、8周后 VAS 评分分别为（2．72±0．54）分、（2．02±0．24）分、（1．24±0．12）分，巴氯芬组在治疗2周、4周、8周后 VAS 评分分别为（3．56±0．44）分、（3．15±0．48）分、（2．58±0．26）分，白脉软膏组 VAS 评分明显低于巴氯芬组，差异均有统计学意义（t ＝2．975、3．359、5．416，均P ＜0．05）]，日常生活能力高于巴氯芬组[白脉软膏组在治疗8周后 MBI 评分为（64．46±10．78）分，巴氯芬组在治疗8周后 MBI 评分为（50．74±9．18）分，白脉软膏组 MBI 评分明显高于巴氯芬组，差异有统计学意义（t ＝3．562，P ＜0．05）]。结论白脉软膏在脑卒中患者中的抗痉挛效果优于巴氯芬。

关键词：白脉软膏巴氯芬脑卒中痉挛

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