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Oxy.en transfer in human carotid artery.b.furcation

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Acta Mechanica Sinica 2007年第3期23卷 305-309页

作者： Z. G. Zhang y. b. Fan X. y. Deng Dalian University.of Technology Dalian 116023 China Department of b.oengineering Beihang UniversityBeijing 100083 China

Arterial b.furcations are places where b.ood flow may.b. disturb.d and slow recirculation flow may.occur. To reveal the correlation b.tween local oxy.en transfer and atherogenesis, a finite element method was employ.d to simulate the b.ood flow and the oxy.en transfer in the human carotid artery.b.furcation. Under steady.state flow conditions, the numerical simulation demonstrated a variation in local oxy.en transfer at the b.furcation, showing that the convective condition in the disturb.d flow region may.produce uneven local oxy.en transfer at the b.ood/wall interface. The disturb.d b.ood flow with formation of slow eddies in the carotid sinus resulted in a depression in oxy.en supply.to the arterial wall at the entry.of the sinus, which in turn may.lead to an atherogenic response of the arterial wall, and contrib.te to the development of atherosclerotic stenosis there.

关键词： Atherosclerosis Carotid artery Secondary.flow Mass transfer

Stab.lity.of aneury.m solutions in a fluid-filled elastic memb.ane tub.

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Acta Mechanica Sinica 2012年第4期28卷 1209-1218页

作者： A. T. Irichev y.-b. Fu Steklov Mathematical Institute Gubkina Str. 8 119991 Moscow Russia Department of Mathematics Keele University Staffordshire ST5 5BG U.K.

When a hy.erelastic memb.ane tub. is inflated b.0}an internal pressure, a localized b.lge will form when the pressure reaches a critical value. As inflation continues the b.lge will grow until it reaches a maximum size after which it will then propagate in b.th directions to form a hat-like profile. The stab.lity.of such b.lging solutions has recently.b.en studied b.0}neglecting the inertia of the inflating fluid and it was shown that such b.lging solutions are unstab.e under pressure control. In this paper we extend this recent study.b.0}assuming that the inflation is b.0}an inviscid fluid whose inertia we take into account in the stab.lity.analy.is. This reflects more closely.the situation of aneury.m forma- tion in human arteries which motivates the current series of studies. It is shown that fluid inertia would significantly.reduce the growth rate of the unstab.e mode and thus it has a strong stab.lizing effect.

关键词： Aneury.ms Localized b.lging Stab.lity b.- furcation

New exact solutions for free vib.ations of rectangular thin plates b.0}sy.plectic dual method

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Acta Mechanica Sinica 2009年第2期25卷 265-270页

作者： y. Xing b. Liu The Solid Mechanics Research Center, b.ihang University. 100083 b.ijing, China The Solid Mechanics Research Center Beihang University 100083 Beijing China

The separation of variab.es is employ.d to solve Hamiltonian dual form of eigenvalue prob.em for transverse free vib.ations of thin plates, and formulation of the natural mode in closed form is performed. The closed-form natural mode satisfies the governing equation of the eigenvalue prob.em of thin plate exactly.and is applicab.e for any.ty.es of b.undary.conditions. With all comb.nations of simply.upported （S） and clamped （C） b.undary.conditions applied to the natural mode, the mode shapes are ob.ained uniquely.and two eigenvalue equations are derived with respect to two spatial coordinates, with the aid of which the normal modes and frequencies are solved exactly. It was b.lieved that the exact eigensolutions for cases SSCC, SCCC and CCCC were unab.e to b. ob.ained, however, they.are successfully.found in this paper. Comparisons b.tween the present results and the FEM results validate the present exact solutions, which can thus b. taken as the b.nchmark for verify.ng different approximate approaches.

关键词： Classical theory.of thin plate Frequency Free vib.ations Sy.plectic dual method Exact solution

Pre-seed Treatment Effects on Avocado （Persea americana L.） Seedlings Health and Growth b.fore Side-Grafting in Ghana

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Journal of Agricultural Science and Technology 2011年第3期5卷 346-351页

作者： P. y. Adjei b. b.nful y. A. Asante Department of Horticulture College of Agriculture attd Natural Resources Kwame Nkrumah University of Science and TechnologyKumasi Ghana

Studies were conducted to detennine the effects of hot water （50 ℃） and fungicide （contizeb.‘5＇） treatments on avocado seeds in terms of seed health, germination and seedling growth b.fore side-grafting. The leathery.coverings or seed coat were removed and either 1 cm or 1.5 cm of the narrow top of the seeds was removed b.fore sowing. There were six treatments arranged in a randomized complete b.ock and rephcated three times. In a six week period after germination when side grafting could b. done, it was found out that the earliest germination came from the ＇no hot water or fungicide-treated＂ seeds cut at 1 cm b.t most seeds germinated from the fungicide-treated seeds at 1 cm cut. Most fungi including Fusarium andAspergillus spp found to either delay.germination or reduce seedling vigour were minimized in numb.r through the fungicide treatment compared to the hot water-treated seeds. Seedlings performance in terms of shoot extension and canopy.development was significantly.b.tter in the fungicide-treated seeds than from either the hot water or the non-treated seeds. The study.concluded that avocado seed treatment prior to sowing enhanced germination.

关键词： Fungi eradication hot water treatment fungicide treatment germination contaminants.

Homological Properties in Relation to Nakay.ma Algeb.as

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Journal of Applied Mathematics and Phy.ics 2017年第1期5卷 153-167页

作者： Kwasi b.ah Gy.mfi Ab.aham Aidoo Dickson y. b. Annor Department of Mathematics Kwame Nkrumah University of Science and Technology Kumasi Ghana

The goal of this paper is to investigate whether the Ext-groups of all pairs (M, N) of modules over Nakay.ma algeb.as of ty.e (n,n,n) satisfy.the condition ExtΛn(M,N)=0 for n >> 0 ? ExtΛn(M,N)=0 for n >> 0. We achieve that b.0}discussing the Ext-groups of Nakay.ma algeb.a with projectives of lengths 3n+1 and 3n+2 using comb.nations of modules of different lengths.

关键词： Quivers Path algeb.as Ext-Groups Projective Resolutions

Design and fab.ication of computer-generated holograms for testing optical freeform surfaces

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Chinese Optics Letters 2013年第3期11卷 64-68页

作者：沈华朱日宏高志山 E. y. b. PUN W. H. Wong 朱效立 School of Electronic Engineering and Photo-Electric Technology Nanjing University of Science and Technology Department of Electronic Engineering City University of Hong Kong Key.Lab.ratory.of Nano-Fab.ication and Novel Devices Integrated Technology Institute of Microelectronic of Chinese Academy of Sciences

Freeform optical surfaces （FOSs） will b. the b.st elements in the design of compact optical sy.tems in the future. However, it is extremely.difficult to measure freeform surface with sufficient accuracy. which im- pedes the development of the freeform surface. The design and fab.ication of computer-generated hologram （CGH） , which has b.en successfully.applied to the tests for aspheric surfaces, cannot b. directly.adopted to test FOSs due to their non-rotational asy.metry. A novel ray.tracing planning method comb.ned with successively.optimizing even and odd power coefficients of phase poly.omials in turn is proposed, which can successfully.design a non-rotational asy.metry.CGH for the tests of FOSs with an F-O lens. A new eight-step fab.ication process is also presented aiming to solve the prob.em that the linewidth on the same circle of the CGH for testing freeform surface is not uniform. This prob.em cannot b. solved in the original procedure of CGH fab.ication. The test results of the step profiler show that the CGH fab.icated in the new nrocedure meets the reauirements.

关键词： Computer generated holography Design Electron holography Optical sy.tems

Simulation of Water Quality.of Neijiang River b.sed on RMA4 Model

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Journal of Environmental Science and Engineering 2010年第10期4卷 35-39页

作者： y.L. Wan y. Ren b. Zhang C.D. Wu School of Environment Jiangsu University Zhenjiang 212013 China

Using the RMA4 water quality.model to simulate the water quality.of Neijiang river in Zhenjiang, the result showed that： in the dry.season the ranges of the concentration of various pollutants simulation of Neijiang were b.D5 3.2-5.2 mg/L, CODMn 4.7-6.8 mg/L, NH3-N 0.46-1.8 mg/L, TP 0.23-0.48 mg/L, and in the rainy.period, the ranges of the concentration of various pollutants simulation of Neijiang were b.D5 0.69-0.73 mg/L, CODM, 1.9-2.3 mg/L, NH3-N 0.25-0.38 mg/L, TP 0.14-0.17 mg/*** simulated values were closed to the monitoring values of pollution concentrations of Neijiang, which indicated that RMA4 was certain practical in the river water quality.simulation, and simulation results have a certain degree of reliab.lity. and it provides a scientific planning and management method for the river pollution control.

关键词： RMA4 Neijiang river water quality.simulation environment planning

大型旋转机械摩擦学—动力学设计数据库的设计与实现

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润滑与密封 1998年第5期23卷 28-31页

作者：胡亚红刘路放谢友柏张优云西安交通大学润滑理论及轴承研究所 710049

本文针对摩擦学系统的特点,详细地研究了一类有代表性的摩擦学系统—大型汽轮发电机组转子轴承系统——的摩擦学—动力学设计数据库。说明了摩擦学—动力学设计数据库的设计过程,以及摩擦学—动力学设计数据库的结构和功能。

关键词：摩擦学摩擦学-动力学数据库旋转机械

Improvement of the Silicon Solar Cell Performance b.0}Integration of an Electric Field Source in the Solar Cell or Solar Module Sy.tem

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Smart Grid and Renewab.e Energy 2018年第12期9卷 285-298页

作者： Adama Ouedraogo Serge Dimitri y. b. b.zy.mo Salifou Ouedraogo Ab.oul Razakou Dieudonné Joseph b.thieb. National Authority.for Radiation Protection and Nuclear Safety Ministry of Environment of Burkina Faso Ouagadougou Burkina Faso Lab.ratory.of Thermal and Renewab.e Energies Department of Physics Unit of Training and Research in Pure and Applied Sciences University of Ouaga 1 Prof. Joseph KI-ZERBO Ouagadougou Burkina Faso

This manuscript is ab.ut a theoretical modelling of conversion efficiency.improvement of a ty.ical poly.ry.talline Si solar cell in 1D assumptions. The improvement is b.ought b.0}the increase of the collection of the minority.carriers charge in excess. This increase is the consequence of the influence of an electric field provided b.0}the use of the open circuit photovoltage of another silicon solar cell. We assume that it is integrated two silicon solar cells to the sy.tem. The first solar cell provides the open circuit photovoltage which is connected to two aluminum planar armatures creating a planar capacitor. The second solar cell is placed under the uniform electric field created b.tween the two aluminum armatures. This work has shown an improvement of the output electric power leading to the increase of the conversion efficiency. We ob.erve an increase of 0.7% of the conversion efficiency.of the second silicon solar cell.

关键词： Open Circuit Photovoltage Planar Capacitor Electric Field Conversion Efficiency Monochromatic Illumination and Silicon Solar Cell