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Uterine Reperfusion Ischemia and Use of Elastic Tourniquet 预览
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作者 J. F. Nnang Essone F. Ovono Abessolo +7 位作者 A. Tsagoulela G. Edjo Nkhilli P. Assoumou J. A. Bang Ntamack E. Anyunzok U. Minkobame J. F. Meye E. Ngou Milama 《生物科学与医学(英文)》 2019年第2期98-119,共22页
Introduction: In humans, it has not been established that the use of elastic tourniquet (ET) during myomectomies, whose delivery times do not exceed 90 minutes, which is responsible for ischemia reperfusion (I/R) syst... Introduction: In humans, it has not been established that the use of elastic tourniquet (ET) during myomectomies, whose delivery times do not exceed 90 minutes, which is responsible for ischemia reperfusion (I/R) systemic. Objectives: To study the plasma variations of markers of I/R during myomectomies performed with ET, whose exposure time does not exceed 90 minutes. Population and methods: Plasma créatinin phosphokinase kinase (CPK) and gluthatione peroxydase (GPX) levels of patients with ET myoma (M + G +, n = 19), taken before, during and after exposure, were compared to those of women operated on myoma without tourniquet (M + G -, n = 15), carriers of unoperated myomas (M + G0, n = 20) and controls (M0G0, n = 18). The duration of exposure of the ET was determined, and perioperative variations of GPX, Ca2+, K+ and CPK between M + G + and others groups were analyzed (p Results: The average duration of exposure of the ET was 51.56 ± 14.12 [30 - 88] min. In M + G +, prior to insertion, CPK was 71.64, GPX 3.537, Ca2+ 3.000, K+ 3.934, and did not vary from those of M + G - (CPK = 59.354, GPX = 3.205, Ca2+ = 2.525, K+ = 3.788), M + G0 (CPK = 71.640, GPX = 2.759, Ca2+ = 3.004, K+ = 3.934) and M0G0 (CPK = 57.2, GPX = 2.306, Ca2+ = 2.879, K+ = 3.705). Conversely, during the posture (CPK = 95.665, GPX = 3.645, Ca2+ = 3.642, K+ = 4.757) and after the release of the ET (CPK = 135.443, GPX = 3.694, Ca2+ = 3.892, K+ = 5.322), these rates were higher among the M + G + compared to the M + G0 and M0G0, but did not differ from those of the M + G - during (CPK = 91.270, GPX = 3.413, Ca2+ = 3.068, K+ = 4.257) and after release (CPK = 137.776, GPX = 3.632, Ca2+ = 3.148, K+ = 5.075). Conclusion: The plasmatic concentration of ischemia (CPK, K+) and reperfusion (GPX, Ca2+) biomarkers does not differ between M + G + and M + G -, but is elevated relatively to controls (M0G0), but also to M + G0’s group. These results show that, for exposure times not exceeding 90 minutes, the elastic tourniquet is probably not the cause of the in 展开更多
关键词 ISCHEMIA REPERFUSION UTERUS ELASTIC TOURNIQUET
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Numerical solutions for cracks in an elastic half-plane 预览
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作者 N.R.F.Elfakhakhre N.M.A.Nik Long Z.K.Eshkuvatov 《力学学报:英文版》 SCIE EI CAS CSCD 2019年第1期212-227,I0006共17页
The behavior of the stress intensity factor at the tips of cracks subjected to uniaxial tension σχ^∞= p with traction-free boundary condition in half-plane elasticity is investigated. The problem is formulated into... The behavior of the stress intensity factor at the tips of cracks subjected to uniaxial tension σχ^∞= p with traction-free boundary condition in half-plane elasticity is investigated. The problem is formulated into singular integral equations with the distribution dislocation function as unknown. In the formulation, we make used of a modified complex potential. Based on the appropriate quadrature formulas together with a suitable choice of collocation points, the singular integral equations are reduced to a system of linear equations for the unknown coefficients. Numerical examples show that the values of the stress intensity factor are influenced by the distance from the cracks to the boundary of the half-plane and the configuration of the cracks. 展开更多
关键词 ELASTIC HALF-PLANE Multiple cracks SINGULAR integral equation Sine-shaped CRACK
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Determination of time-dependent strengths of salt pillars based on strain energy principle 预览
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作者 Prapasiri Junthong Supattra Khamrat +1 位作者 Suratwadee Sartkaew Kittitep Fuenkajorn 《矿业科学技术学报:英文版》 CSCD 2019年第2期273-279,共7页
The objective of this study is to determine the time-dependent strengths of salt mine pillars in the Maha Sarakham formation,northeast of Thailand.Strain rate-controlled triaxial compression tests have been performed ... The objective of this study is to determine the time-dependent strengths of salt mine pillars in the Maha Sarakham formation,northeast of Thailand.Strain rate-controlled triaxial compression tests have been performed on salt specimens under confining pressures from 0 MPa to 12 MPa.The strain rates are from 10^-7 s^-1 to 10^-4 s^-1.The axial stresses and lateral strains are monitored through the strain-softening region.The results indicate that the strengths and elastic moduli increase exponentially with the strain rates.The power creep law parameters are calibrated with the test results,and hence allows constructing series of strain-time curves for the salt pillars under different depths and extraction ratios.The strain energy density principle is applied to develop a strength criterion for the salt pillars.Combining this criterion with the series of the strain-time curves the time-dependent strengths of the salt pillars for different extraction ratios can be predicted. 展开更多
关键词 DILATION Failure Elastic MODULUS Strain rate Time-dependency
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Intra-trench variations in flexural bending of the subducting Pacific Plate along the Tonga-Kermadec Trench 预览
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作者 Fan Zhang Jian Lin Zhiyuan Zhou 《海洋学报:英文版》 SCIE CAS CSCD 2019年第11期81-90,共10页
We conducted a detailed analysis of along-trench variations in the flexural bending of the subducting Pacific Plate at the Tonga-Kermadec Trench.Inversions were conducted to obtain best-fitting solutions of trench-axi... We conducted a detailed analysis of along-trench variations in the flexural bending of the subducting Pacific Plate at the Tonga-Kermadec Trench.Inversions were conducted to obtain best-fitting solutions of trench-axis loadings and variations in the effective elastic plate thickness for the analyzed flexural bending profiles.Results of the analyses revealed significant along-trench variations in plate flexural bending:the trench relief(W0)of 1.9 to 5.1 km;trench-axis vertical loading(V0)of-0.5×10^12 to 2.2×10^12 N/m;axial bending moment(M0)of 0.1×10^17 to 2.2×10^17 N;effective elastic plate thickness seaward of the outer-rise region(Te^M)of 20 to 65 km,trench-ward of the outer-rise(Te^M)of 11 to 33 km,and the transition distance(Xr)of 20 to 95 km.The Horizon Deep,the second greatest trench depth in the world,has the greatest trench relief(W0 of 5.1km)and trench-axis loading(V0 of 2.2×10^12N/m);these values are only slightly smaller than that of the Challenger Deep(W0 of 5.7km and V0 of 2.9×10^12N/m)and similar to that of the Sirena Deep(W0 of 5.2 km and V0 of 2.0×10^12 N/m)of the Mariana Trench,suggesting that these deeps are linked to great flexural bending of the subducting plates.Analyses using three independent methods,i.e.,the/inversion,the flexural curvature/yield strength envelope analysis,and the elasto-plastic bending model with normal faults,all yielded similar average Te reduction of 28%-36% and average Te reduction area of 1195-1402 km^2 near the trench axis.The calculated brittle yield zone depth from the flexural curvature/yield strength envelope analysis is also consistent with the distribution of the observed normal faulting earthquakes.Comparisons of the Manila,Philippine,Tonga-Kermadec,Japan,and Mariana Trenches revealed that the average values Te^M of Te^M and both in general increase with the subducting plate age. 展开更多
关键词 Tonga-Kermadec Trench horizon deep axial vertical force axial bending moment effective elastic thickness flexural curvature analysis
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Elastic modulus prediction for hybrid polymer composites 预览
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作者 Denis Rodrigue 《材料工程研究(英文)》 2019年第2期64-68,共5页
To improve on the mechanical properties of polymers in general, the concept of hybrid composites was developed by using two or more different reinforcements in the same matrix, or by using two or more different sizes ... To improve on the mechanical properties of polymers in general, the concept of hybrid composites was developed by using two or more different reinforcements in the same matrix, or by using two or more different sizes of the same reinforcement (auto-hybrid composites). In this case, most of the literature results showed that the resulting elastic modulus can be well approximated by the simple rule of mixture (linear additive law) from the tensile modulus of each reinforcement used alone. But is some cases, a positive deviation from this linear approximation was reported up to a point where an optimum composition can give a modulus above the value of both reinforcements used separately. In this work, a simple model is presented to show that positive deviations are possible and the optimum reinforcement ratio is around 25/75 in terms of the lowest/highest reinforcing particle. The model is also compared with literature data where good qualitative agreements are obtained as a first approximation. 展开更多
关键词 hybrid POLYMER COMPOSITES ELASTIC MODULUS OPTIMUM COMPOSITION
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基于附加噪音协变量的Elastic Net高维统计分析 预览
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作者 丁毅涛 胡俊英 +1 位作者 李永新 李建辉 《统计与决策》 CSSCI 北大核心 2019年第15期74-78,共5页
文章研究协变量中具有附加噪音的Elastic Net模型的高维统计性质。通过对矩阵■进行分析,以及选择适当的■。得到了Elastic Net估计的界。当矩阵■满足下限制特征条件,并且■和■的偏差条件成立时,任意解■与未知参数■有统一误差界。
关键词 变量选择 Lasso ELASTIC NET 限制特征条件
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基于Elastic Stack的分布式数据采集与分析平台探索
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作者 林朝炽 《网络安全技术与应用》 2019年第2期38-38,61共2页
分布式架构、大数据技术应用是当下人民银行IT技术架构转型的两个重要方向。研究利用开源软件技术和工具,是推动人民银行IT技术架构转型,提高人民银行信息技术架构自主可控的重要手段。分布式架构技术在赋予应用系统高可用性、高可靠性... 分布式架构、大数据技术应用是当下人民银行IT技术架构转型的两个重要方向。研究利用开源软件技术和工具,是推动人民银行IT技术架构转型,提高人民银行信息技术架构自主可控的重要手段。分布式架构技术在赋予应用系统高可用性、高可靠性等诸多优势的同时,也带来系统运维监控高度复杂、应用故障和网络异常事件日志排查定位更加困难等诸多难题。温州市中支在杭州中支指导下试点运用Elastic Stack技术,实现人民银行业务网网络设备、应用系统日志数据和网络通信数据的采集、存储、检索与分析,服务器与应用程序性能指标数据的采集,应用层服务可用性和设备状态的在线监控,不仅对完善分布式架构应用运维手段进行了有益尝试,也为完善数据采集手段和大数据分析工具提供了有益借鉴。 展开更多
关键词 分布式 大数据 ELASTIC STACK 日志
Nonlinear Shell Models of Kirchhoff-Love Type:Existence Theorem and Comparison with Koiter’s Model
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作者 Cristinel MARDARE 《应用数学学报:英文版》 SCIE CSCD 2019年第1期3-27,共25页
We define two nonlinear shell models whereby the deformation of an elastic shell with small thickness minimizes ad hoc functionals over sets of admissible deformations of Kirchhoff-Love type. We establish that both mo... We define two nonlinear shell models whereby the deformation of an elastic shell with small thickness minimizes ad hoc functionals over sets of admissible deformations of Kirchhoff-Love type. We establish that both models are close in a specific sense to the well-known nonlinear shell model of W.T. Koiter and that one of them has a solution, by contrast with Koiter’s model for which such an existence theorem is yet to be proven. 展开更多
关键词 Nonlinearly ELASTIC SHELLS Kirchhoff-Love Koiter EXISTENCE Theory ASYMPTOTICS
Comparative Study on Various Methods of Pressure in Compression Stockings 预览
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作者 李杰聪 柯思成 谢红 《东华大学学报:英文版》 EI CAS 2019年第1期52-61,共10页
A series of self-designed and woven compression stockings were used in this pressure comparison experiment. In order to compare the differences of the garment pressure values exerted by the compression stockings with ... A series of self-designed and woven compression stockings were used in this pressure comparison experiment. In order to compare the differences of the garment pressure values exerted by the compression stockings with different structure parameters among three methods. The experiments were carried out with Flexi force sensors. The pressure value of nine pairs of compression stockings on five subjects and the model leg was collected, and the tensile force of the every section of these stockings was collected to calculate the pressure according to Laplace’s equation. The data analysis results show that the pressure values of the compression stockings obtained by comparing the three methods have great differences in various testing methods. There is a significant correlation between processing parameters and stitch density(SD). The pressure design of the compression stockings should be based on the actual wearing of the pressure. 展开更多
关键词 compression STOCKING PRESSURE study CYLINDER parametr(CP) ELASTIC MOTOR parrametor(EMP)
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Design and Development of a Wheel-less Snake Robot with Active Stiffness Control for Adaptive Pedal Wave Locomotion
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作者 Mohammadali Javaheri Koopaee Sander Bal +1 位作者 Christopher Pretty Xiaoqi Chen 《仿生工程学报:英文版》 SCIE EI CSCD 2019年第4期593-607,共15页
This paper presents the design and manufacture process of a wheel-less,modular snake robot with series elastic actuators to reliably measure motor torque signal and investigate the effectiveness of active stiffness co... This paper presents the design and manufacture process of a wheel-less,modular snake robot with series elastic actuators to reliably measure motor torque signal and investigate the effectiveness of active stiffness control for achieving adaptive snake-like locomotion.A polyurethane based elastic element to be attached between the motor and the links at each joint was designed and manufactured using water jet cutter,which makes the final design easier to develop and more cost-effective,compared to existing snake robots with torque measurement capabilities.The reliability of such torque measurement mechanism was examined using simulated dynamical model of pedal wave motion,which proves the efficacy of the design.A distributed control system was also designed,which with the help of an admittance controller,enables active control of the joint stiffness to achieve adaptive snake robot pedal wave locomotion to climb over obstacles,which unlike existing methods does not require prior information about the location of the obstacle.The effectiveness of the proposed controller in comparison to open-loop control strategy was verified by the number of experiments.The results show the capability of the robot to successfully climb over obstacles with the height of more than 55%of the diameter of the snake robot modules. 展开更多
关键词 modular SNAKE robot series elastic ACTUATOR ACTIVE stiffness control PEDAL WAVE locomotion ADAPTIVE locomotion
Structural, elastic, and electronic properties of topological semimetal WC-type MX family by first-principles calculation
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作者 Sami Ullah 王磊 +2 位作者 李江旭 李荣汉 陈星秋 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期78-86,共9页
Recently, the non-centrosymmetric WC-type materials(i.e., MoP, ZrTe, TaN, etc) have attracted extensive interest due to the discovery of their topological properties.By means of the first-principles calculations, here... Recently, the non-centrosymmetric WC-type materials(i.e., MoP, ZrTe, TaN, etc) have attracted extensive interest due to the discovery of their topological properties.By means of the first-principles calculations, here we have investigated the structural, thermodynamic, elastic, and electronic properties of the WC-type MX compounds(TiS, TiSe, TiTe, ZrS, ZrSe,ZrTe, HfS, HfSe, and HfTe).Among these nine compounds, five of them(TiS, ZrS, ZrSe0.9, ZrTe, and Hf0.92 Se) have been experimentally synthesized to crystallize in the WC-type structure and other four members have never been reported.Our calculations demonstrated that they are all structurally, thermodynamically, and dynamically stable, indicating that all of them should be possibly synthesized.We have also derived their elastic constants of single crystalline and their bulk and shear moduli in terms of the R.Hill approximations.Furthermore, in similarity to ZrTe, all these compounds have been theoretically derived to be topological semimetals.Whereas TiS is unique because of the coexistence of the Dirac nodal lines(DNLs) and sixfold degenerate nodal points(sixfold DNPs), the other eight members are revealed to exhibit coexisted Weyl nodes(WPs) and triply degenerate nodal points(TDNPs).Their electronic and topological properties have been further discussed. 展开更多
关键词 TOPOLOGICAL semimetals WC-type materials MX FAMILY ELASTIC properties
In-Plane Semi-Linear Cloaks with Arbitrary Shape
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作者 Dengke Guo Zheng Chang Gengkai Hu 《固体力学学报:英文版》 SCIE EI CSCD 2019年第3期277-286,共10页
Soft materials with semi-linear strain energy function can be used as smart transformation media to manipulate elastic waves via finite pre-deformation. However, the intrinsic cons train ts involved in such materials ... Soft materials with semi-linear strain energy function can be used as smart transformation media to manipulate elastic waves via finite pre-deformation. However, the intrinsic cons train ts involved in such materials limit the shapes of t ransformation devices to very sim - pie cases. In this work, combining theoretical and numerical analyses, we report an approach of achieving the in-plane elastodynamic cloak with arbitrary shape. We demonstrate that with the appropriate out-of^plane st retch applied on the semi-linear material, cloaking effec t can be achieved for both P- and SV-waves in the symmetrie plane of a 3D domain, and the performance of the cloak with arbitrary cross section can be guaranteed for relatively small in-plane rot at ion. In addition, we propose an empirical formula to predic t the deformation limit of the cloaks with semi-linear materials. This work may stimulate the experimental research on softmatter- based transformation devices. Potential applications can be anticipated in nondestructive testing, structure impact protection, biomedical imaging and soft robotics. 展开更多
关键词 Elastic WAVES CLOAK HYPERELASTICITY SEMI-LINEAR ARBITRARY shape
Applicability of 9 Be global optical potential to reactions of 7,10,11,12Be
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作者 徐永丽 韩银录 +3 位作者 梁海英 吴振东 郭海瑞 蔡崇海 《中国物理C:英文版》 SCIE CAS CSCD 2019年第9期55-61,共7页
Elastic scattering angular distributions and total reaction cross-sections of 7,10,11,12Be projectiles are predicted by the systematic 9Be global phenomenological optical model potential for target mass numbers rangin... Elastic scattering angular distributions and total reaction cross-sections of 7,10,11,12Be projectiles are predicted by the systematic 9Be global phenomenological optical model potential for target mass numbers ranging from 24 to 209.These predictions provide a detailed analysis by their comparison with the available experimental data.Furthermore,these elastic scattering observables are also predicted for some targets out of the mass number range.The results are in reasonable agreement with the existing experimental data,and they are presented in this study. 展开更多
关键词 global PHENOMENOLOGICAL optical model potential elastic scattering ANGULAR DISTRIBUTIONS total reaction cross SECTIONS
Relationship between the microstructure and properties of thermomechanically processed Fe-17Mn and Fe-17Mn-3Al steels 预览
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作者 Renuprava Dalai Siddhartha Das Karabi Das 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第1期64-75,共12页
Two austenitic Mn steels(Fe-17Mn and Fe-17Mn-3Al(wt%,so as the follows))were subjected to thermomechanical processing(TMP)consisting of forging followed by solutionization and hot rolling.The rolled samples were annea... Two austenitic Mn steels(Fe-17Mn and Fe-17Mn-3Al(wt%,so as the follows))were subjected to thermomechanical processing(TMP)consisting of forging followed by solutionization and hot rolling.The rolled samples were annealed at 650 and 800℃to relieve the internal stress and to induce recrystallization.The application of TMP and heat treatment to the Fe-17Mn/Fe-17Mn-3Al steels refined the austenite grain size from 169μm in the as-solutionized state to 9–13μm,resulting in a substantial increase in hardness from HV 213 to HV 410 for the Fe-17Mn steel and from HV 210 to HV 387 for the Fe-17Mn-3Al steel.The elastic modulus values,as evaluated by the nanoindentation technique,increased from(175±11)to(220±12)GPa and from(163±15)to(205±13)GPa for the Fe-17Mn and Fe-17Mn-3Al steels,respectively.The impact energy of the thermomechanically processed austenitic Mn steels was lower than that of the steels in their as-solutionized state.The addition of Al to the Fe-17Mn steel decreased the hardness and elastic modulus but increased the impact energy. 展开更多
关键词 AUSTENITIC manganese steel(AMS) THERMOMECHANICAL processing(TMP) microstructure property hardness elastic modulus
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基于河湖水网公园绿地的"大海绵"体系构建--以珠海市金湾试点区为例 预览
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作者 姚鹏飞 《城市道桥与防洪》 2019年第7期152-156,M0018共6页
公园绿地、河湖水网作为天然的海绵体,在海绵城市建设过程中具有重要作用。珠海市金湾试点区结合本地特征,在源头削减的基础上,统筹考虑区域河湖水网公园绿地,充分发挥河湖水网公园绿地自然积存、自然渗透、自然净化的作用,实现径流雨... 公园绿地、河湖水网作为天然的海绵体,在海绵城市建设过程中具有重要作用。珠海市金湾试点区结合本地特征,在源头削减的基础上,统筹考虑区域河湖水网公园绿地,充分发挥河湖水网公园绿地自然积存、自然渗透、自然净化的作用,实现径流雨水的有效控制和地表水质的明显改善,将周边片区有效的串联,使碎片式的海绵体连片化,并最终形成“大海绵区域”,发挥调蓄、净化效果,综合解决片区水量平衡。突出“大海绵”完善区域“弹性”构建,由此形成的“大小海绵”共存体系,是满足海绵城市建设“弹性”诉求的根本途径,为城市发展兼备形象与内涵提供重要支持。 展开更多
关键词 公园绿地 河湖水网 大海绵 弹性
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Normal Contact Model for Elastic and Plastic Mechanics of Rough Surfaces
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作者 Dong Wang Zhousuo Zhang +1 位作者 Fan Jin Xuanhua Fan 《固体力学学报:英文版》 SCIE EI CSCD 2019年第2期148-159,共12页
An elastic and plastic mechanical model is proposed to characterize the normal contact of rough surfaces. The contact process is considered as three separated contact regimes, i.e., the fully elastic, mixed elastic一p... An elastic and plastic mechanical model is proposed to characterize the normal contact of rough surfaces. The contact process is considered as three separated contact regimes, i.e., the fully elastic, mixed elastic一plastic and fully plastic ones. The Hertzian elastic contact solutions and the classical fully plastic contact model of Abbott and Fires tone are used to model the contact behaviors of fully elastically deformed asperities and fully plastically deformed ones, respectively. For the mixed elastic-plastic regime, an improved Hermit interpolation method is applied to enforce the continuity and smoothness at the critical contact interference, and to decrease the interpolation waving effect by transforming the physical quantities of contact load into logarithmic coordinates. The contac t model of rough surfaces is formula ted by using the Greenwood and Williamson^ statistics analysis. Comparisons with the CEB, ZMC and KE models are then performed to examine the effects of plasticity index and mean separation. Agreeing well with the ZMC model, our results show that the total contact load of rough surfaces decreases with the increase in mean separation, and the difference between the prediction results of elastic models and the plastic ones also decreases, indicating that the contact behaviors mainly dominated by plastically deformed asperities have been changed to be controlled by elastically deformed ones. Larger plasticity index represents more plastically deformed asperities, inducing normal contact behaviors mainly dominated by plastic solutions. 展开更多
关键词 ROUGH surfaces ELASTIC plastic ASPERITY contact LOGARITHM TRANSFORMATION STATISTICS analysis
Thoracic aorta thickness and histological changes with aging:an experimental rat model 预览
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作者 Giulio Cesar Gequelim Djanira Aparecida da Luz Veronez +2 位作者 Gustavo Lenci Marques Camila Harumi Tabushi Ronaldo da Rocha Loures Bueno 《老年心脏病学杂志:英文版》 SCIE CAS CSCD 2019年第7期580-584,共5页
The three main components of the media layer of the aorta are elastic fibers,collagen fibers and smooth muscle cells(SMC).[1]This layer’s elastic properties are major determinants of its biomechanics in health and di... The three main components of the media layer of the aorta are elastic fibers,collagen fibers and smooth muscle cells(SMC).[1]This layer’s elastic properties are major determinants of its biomechanics in health and disease states.[2,3]Age-related changes in such elastic properties are associated with altered hemodynamic parameters,such as systolic hypertension,[4,5]and end-organ damage,[6,7]and are thought to result from changes of its main components. 展开更多
关键词 AGING COLLAGEN ELASTIC fibers SMOOTH MUSCLE cells
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Quantum density functional theory studies of structural,elastic, and opto-electronic properties of ZMoO3 (Z=Ba and Sr) under pressure
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作者 Saad Tariq A A Mubarak +2 位作者 Saher Saad M Imran Jamil S M Sohail Gilani 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第6期302-312,共11页
In continuation of our recent report on molybdates [Appl. Phys. A 124, 44(2018)], the structural, electronic, elastic,and optical properties of ZMoO3(Z = Ba and Sr) molybdates are investigated under pressure(10 GPa–5... In continuation of our recent report on molybdates [Appl. Phys. A 124, 44(2018)], the structural, electronic, elastic,and optical properties of ZMoO3(Z = Ba and Sr) molybdates are investigated under pressure(10 GPa–50 GPa) comprehensively by deploying the density functional theory. Our investigations show that the studied compounds exhibit stable cubic phase with metallic attributes. The thermodynamic parameters such as enthalpy of formation, Debye, and melting temperatures of the compounds are observed to increase with pressure. While the Gr¨uninsen parameter and the coefficient of super-plastic deformation decrease as the pressure increases. Mechanical properties elucidate an increase in measured values of hardness, bulk, shear, and young’s moduli with pressure. Our results suggest that the studied compounds are useful in high pressure optoelectronic devices. The optical properties of BaMoO3(BMO) and SrMoO3(SMO) are computed for the radiation of up to 35 eV. The present compounds show beneficial optical applications in the anti-reflection coating,lenses, and the high avoiding solar heating applications in the variant applied pressure. 展开更多
关键词 optical PROPERTIES high pressure ELASTIC PROPERTIES electronic PROPERTIES
高铁动车组外风挡胶囊用聚氨酯弹性涂料的研制 预览
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作者 周如东 付敏 +8 位作者 朱晓丰 赵宝华 朱亚君 李文凯 陆文明 潘云飞 张睿 刘志远 郭亮亮 《涂层与防护》 2019年第7期1-5,共5页
采用高性能羟基聚酯树脂与自制的SF弹性固化剂作为主要成膜物,以聚四氟乙烯粉末为耐磨粉体,制备了高铁动车组外风挡胶囊用聚氨酯弹性涂料。重点探讨了不同羟基树脂、多异氰酸酯类固化剂、NCO/OH物质的量比以及耐磨粉体用量等对涂料性能... 采用高性能羟基聚酯树脂与自制的SF弹性固化剂作为主要成膜物,以聚四氟乙烯粉末为耐磨粉体,制备了高铁动车组外风挡胶囊用聚氨酯弹性涂料。重点探讨了不同羟基树脂、多异氰酸酯类固化剂、NCO/OH物质的量比以及耐磨粉体用量等对涂料性能的影响。研究结果表明,所研制的涂料具有优异的力学性能、耐磨性能以及环境可靠性,能够满足高铁动车组外风挡胶囊的防护要求。 展开更多
关键词 外风挡 弹性 耐磨 聚氨酯 涂料
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On the Weissenberg effect of turbulence 预览
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作者 Yu-Ning Huang Wei-Dong Su Cun-Biao Lee 《力学快报:英文版》 CAS CSCD 2019年第4期236-245,I0003共11页
Within the framework of the Navier–Stokes equations,the Weissenberg effect of turbulence is investigated.We begin with our investigation on the elastic effect of homogeneous turbulent shear flow.First,in the sense of... Within the framework of the Navier–Stokes equations,the Weissenberg effect of turbulence is investigated.We begin with our investigation on the elastic effect of homogeneous turbulent shear flow.First,in the sense of Truesdell(Physics of Fluids,1964)on the natural time of materials,we derive the natural time of turbulence,and use it together with the natural viscosity of turbulence derived in the article of Huang et al.(Journal of Turbulence,2003)to define the natural Weissenberg number of turbulence as a measure of the elastic effect of homogeneous turbulence.Second,we define a primary Weissenberg number of turbulence,which in laminar flow reduces to the Weissenberg number widely applied in rheology to characterize the elasticity of visco-elastic fluids.Our analysis based on the experimental results of Tavoularis and Karnik(Journal of Fluid Mechanics,1989)indicates that the larger is the Weissenberg number of turbulence,the more elastic becomes the turbulent flow concerned.Furthermore,we put forth a general Weissenberg number of turbulence,which includes the primary Weissenberg number of turbulence as a special case,to measure the overall elastic effects of turbulence.Besides,it is shown that the general Weissenberg number can also be used to characterize the elastic effects of non-Newtonian fluids in laminar flow. 展开更多
关键词 NORMAL stress DIFFERENCE Natural time of TURBULENCE Weissenberg NUMBER of TURBULENCE ELASTIC EFFECT Non-Newtonian fluid
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