谐和与有界噪声联合参激作用下的Visco-Elastic系统

研究了带visco＿elastic项的非线性系统,在谐和与有界噪声联合参激作用下的响应和稳定性问题· 用多尺度法分离了系统的快变项,并求出了系统的最大Liapunov指数和稳态概率密度函数,根据最大Liapunov指数可得系统解稳定的充分必要条件· 讨论了系统的visco＿elastic项对系统阻尼项和刚度项的贡献。

交互式数字叙事:加拿大Writing New Body Worlds阅读治疗新探索

文章基于相关研究文献与语料,对加拿大WNB阅读治疗实践进行梳理与归纳。WNB首次使用交互式数字叙事技术,构建面向公众的阅读治疗平台,以其交互式特征,融合了阅读和治疗引导两个过程,提供可访问的非临床方式,可面向大规模人群实现预防性健康干预。基于数据与计算的精准化阅读治疗是数字人文视角下的新变革,更具推广应用价值;以在线阅读平台建设为依托,推进实施平台化的阅读和治疗应成为未来发展方向之一;基于阅读形态与体验因技术赋能而改变的现状,图书馆应发挥引领作用,积极收集、创建或协助创建数字故事,推进阅读推广、服务与治疗的融合性发展,成为社区建设促进者、历史欣赏者和社区参与倡导者,也使阅读借助交互式数字叙事这一新载体,更好地发挥变革的力量,促进健康与幸福。

One-dimensional consolidation of visco-elastic aquitard due to withdrawal of deep-groundwater

One-dimensional consolidation of visco-elastic aquitard due to withdrawal of deep-groundwater was studied.Merchant model was used to simulate visco-elastic characteristic of aquitard.General solutions of the governing equation were obtained by applying Laplace transform with respect to time,and then the pore-pressure,strain and deformation of the aquitard could be calculated by Laplace inversion.A case was analyzed to validate the correctness of the present method.Finally,some consolidation properties of the problem were analyzed.Comparison of the average degree of consolidation defined by pore pressure with that defined by settlement shows that they are different and the maximum difference is 22.8%.The influences of parameters of Merchant model and the rate of the water level on the consolidation are great.The smaller the viscosity coefficient is,the later the rate of consolidation decreases.The rate of consolidation is decreased with the decrease of the rate of the water level fall.Therefore,the lagged effect of land subsidence should be considered in the actual project.

Visco-elastic Properties of VES Diverting Acid for Carbonate Reservoirs

Storage modulus and loss modulus is the main performance index of visco-elastic properties.In this paper the storage modulus and loss modulus of a new diverting acid and their influencing factors were systematically investigated.Besides,the constitutive equations of the diverting acid at different temperatures were elicited from shearing experiments,which show that the visco-elastic surfactant(VES)acid system is a non-Newtonian power law fluid at low temperature and a Newtonian fluid at high temperature.The storage modulus and loss modulus at different temperatures,pH,and VES content in the acid are critical for the design of acid stimulation for oil well,especially when the VES acid is used in this field only on trial and the basic data are in urgent needed for the design and construction of the acidification stimulation.

Heat and Mass Transfer in MHD Visco-Elastic Fluid Flow through a Porous Medium over a Stretching Sheet with Chemical Reaction

This paper presents the study of convective heat and mass transfer characteristics of an incompressible MHD visco-elastic fluid flow immersed in a porous medium over a stretching sheet with chemical reaction and thermal stratification effects. The resultant governing boundary layer equations are highly non-linear and coupled form of partial differential equations, and they have been solved by using fourth order Runge-Kutta integration scheme with Newton Raphson shooting method. Numerical computations are carried out for the non-dimensional physical parameters. Here a numerical has been carried out to study the effect of different physical parameters such as visco-elasticity, permeability of the porous medium, magnetic field, Grashof number, Schmidt number, heat source parameter and chemical reaction parameter on the flow, heat and mass transfer characteristics.

3D body解剖软件联合PACS系统在骨科临床实践教学中的应用

目的探讨3D body解剖软件结合医学影像存档与通信系统(PACS)在骨科临床实践教学中的应用效果。方法选择2023年1月至2023年12月在浙江大学医学院附属邵逸夫医院骨科轮转的60名实习生,按照随机数字表法分成实验组和对照组,每组30名。对照组采用传统线上结合线下的混合式教学方法,实验组采用3D body解剖软件联合PACS系统带教模式。在实习期结束时,对两组实习生进行闭卷理论考试与临床实践操作考核,并采用问卷调查方式评估实习生对课程的满意度。结果实验组实习生的理论考试与临床实践操作成绩均高于对照组,差异均有统计学意义(t分别=6.59、4.22,P均<0.05)。实验组实习生在学习兴趣、教学难度、专业能力以及医患沟通能力提升方面的满意度均高于对照组,差异均有统计学意义(χ^(2)分别=9.93、3.77、6.94、8.52,P均<0.05)。结论3D body解剖软件联合PACS系统带教模式运用到骨科实习生的临床教学中,能帮助实习生提高学习兴趣以及医患沟通能力,加强对骨科知识的掌握,降低知识的理解难度,对于提升临床医学教学质量具有重要意义。

Vibration of Visco-Elastic Parallelogram Plate with Parabolic Thickness Variation

The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and that the thickness varies parabolically in one direction i.e. along length of the plate. Rayleigh-Ritz technique has been used to determine the frequency equation. A two terms deflection function has been used as a solution. For visco-elastic, the basic elastic and viscous elements are combined. We have taken Kelvin model for visco-elasticity that is the combination of the elastic and viscous elements in parallel. Here the elastic element means the spring and the viscous element means the dashpot. The assumption of small deflection and linear visco-elastic properties of “Kelvin” type are taken. We have calculated time period and deflection at various points for different values of skew angles, aspect ratio and taper constant, for the first two modes of vibration. Results are supported by tables. Alloy “Duralumin” is considered for all the material constants used in numerical

Effect of Non-Homogeneity on Thermally Induced Vibration of Orthotropic Visco-Elastic Rectangular Plate of Linearly Varying Thickness

The analysis presented here is to study the effect of non-homogeneity on thermally induced vibration of orthotropic visco-elastic rectangular plate of linearly varying thickness. Thermal vibrational behavior of non-homogeneous rectangular plates of variable thickness having clamped boundary conditions on all the four edges is studied. For non–homogeneity of the plate material, density is assumed to vary linearly in one direction. Using the method of separation of variables, the governing differential equation is solved. An approximate but quite convenient frequency equation is derived by using Rayleigh-Ritz technique with a two-term deflection function. Time period and deflection at different points for the first two modes of vibration are calculated for various values of temperature gradients, non- homogeneity constant, taper constant and aspect ratio. Comparison studies have been carried out with non-homogeneous visco-elastic rectangular plate to establish the accuracy and versatility.

ONE-DIMENSIONAL CONSOLIDATION OF LAYERED AND VISCO-ELASTIC SOILS UNDER ARBITRARY LOADING

Based on the layered visco-elastic soil model, according to the Terzaghi's one dimensional consolidation theory, by the method of Laplace transform and matrix transfer technique, the problems about the consolidation of layered and saturated visco-elastic soils under arbitrary loading were solved. Through deductions, the general solution, in the terms of layer thickness, the modulus and the coefficients of permeability and Laplacian transform's parameters was obtained. The strain and deformation of the layered and saturated visco-elastic soils under arbitrary loading can be calculated by Laplace inversion. According to the results of several numerical examples, the consolidation of visco-elastic soils logs behind that of elastic soils. The development of effective stress and the displacement is vibrant process under cyclic loading. Finally, an engineering case is studied and the results prove that the methods are very effective.

Russell body gastritis with Dutcher bodies evaluated using magnification endoscopy

Russell body gastritis(RBG) is an unusual type of chronic gastritis characterized by marked infiltration of Mott cells,which are plasma cells filled with spherical eosinophilic bodies referred to as Russell bodies.It was initially thought that Helicobacter pylori(H.pylori) infection was a major cause of RBG and that the infiltrating Mott cells were polyphenotypic;however,a number of cases of RBG without H.pylori infection or with monoclonal Mott cells have been reported.Thus,diagnostic difficulty exists in distinguishing RBG with monoclonal Mott cells from malignant lymphoma.Here,we report an unusual case of an 86-year-old-Japanese man with H.pylori-positive RBG.During the examination of melena,endoscopic evaluation confirmed a 13-mm whitish,flat lesion in the gastric antrum.Magnification endoscopy with narrowband imaging suggested that the lesion was most likely a poorly differentiated adenocarcinoma.Biopsy findings were consistent with chronic gastritis with many Mott cells with intranuclear inclusions referred to as Dutcher bodies.Endoscopic submucosal dissection confirmed the diagnosis of RBG with kappa-restricted monoclonal Mott cells.Malignant lymphoma was unlikely given the paucity of cytological atypia and Ki-67 immunoreactivity of monoclonal Mott cells.This is the first reported case of RBG with endoscopic diagnosis of malignant tumor and the presence of Dutcher bodies.

The Relevance of Michel Serres’s Idea of Bodily Hominescence for a Convergence of Posthumanism and Transhumanism: A Trans/Posthuman Body

Faced with the challenge of arguments about the relation of post-,and trans-humanism,putting forth questions on their“antagonism”,or“convergence”,I propose to(re-)evaluate/highlight the relevance of the thinking of Michel Serres for posthuman debates.It specifically seems to me that Serresian idea of bodily hominescence can be read as a suggestion of“convergence”of post-and trans-humanism.Starting from the assumption that the body is a crucial node of both of them in that its consideration by one and the other marks a major front of their divergence(tool body according to transhumanism,dimensional body according to posthumanism),I seem to grasp,within the Serresian theme of the hominescent body as totipotent/virtual,the idea of bodily virtuality as a point of their convergence.Following Serres’s argument that,due to its virtuality/potentiality(intended as the totality of the possibilities),the body,though always involved in(technological)hybridization processes,is difficult to be artificially reproduced and to be reduced to information,I assume virtuality as an“operational concept”capable of“producing”convergence of post-and trans-humanism.Such a concept allows me,in fact,to read the body(re-)invested,by technology as an infiltrative agent,of a dimensional role as hybridizer(and in this sense normalized).Through virtuality,therefore,I think to be able to understand the body as a meeting ground between trans-and post-component,in the sense that technological“intervention”no longer constitutes an enhancement of the body,but a hybridizing event not implying dis-incarnation but rather normalization of body’s dimensional value;precisely such,due eminently to hybridization with otherness within a process of technological infiltration.The body normalized by such a technology is therefore a trans-posthuman body,in the sense of being contaminated by technological processes keeping it in its dimensionality.In order to better illustrate this idea,I propose to examine Serresian metaphor of the body as a trunk without branches with cultural cut twigs,which seems to me to effectively express the theme of the body as a ground/condition of hybridization,i.e.,as an anthropo-techno-poietic dimension.I aim so at showing the relevance of Serres’s thought to conceive,in a convergent perspective,a body,not to be strengthened,but to be normalized in its dimensionality,namely,a trans/posthuman body in a trans/posthumanist context.

An analytic solution describing the visco-elastic deformation of coal pillars in room and pillar mine

Coal pillar deformation is typically nonlinear and time-dependent. The accurate prediction of this defor- mation has a vital importance for the successful implementation of mining techniques. These methods have proven very important as a way to excavate coal resources from under buildings, railways, or water bodies. Elastic and visco-elastic theory are employed with a Maxwell model to formulate an analytic solution for displacement of coal pillars in room and pillar mine. These results show that the visco-elastic solution adequately predicts the coal pillar deformation over time. We conclude that the visco-elastic solution can predict the coal pillar and roadway displacement from the measured geological parameters of the conditions in situ. Furthermore, this method would be useful for mine design, coal pillar support optimization, ground subsidence prediction, and coal pillar stability analysis.

Rheological Behaviour for Polymer Melts and Concentrated Solutions Part Ⅰ:A New Multiple Reptation Model to Predict the Nonlinear Visco-elasticity with Nagai Chain Constraints in Entangled Polymer Melts

An approach of stochastically statistical mechanics and a unified molecular theory of nonlinear viscoelasticity with constraints of Nagai chain entanglement for polymer melts have been proposed. A multimode model structure for a single polymer chain with n tail segments and N reversible entanglement sites on the test polymer chain is developed. Based on the above model structure and the mechanism of molecular flow by the dynamical reorganization of entanglement sites, the probability distribution function of the end-to-end vectr for a single polymer chain at entangled state and the viscoelastic free energy of deformation for polymer melts are calculated by using the method of the stochastically statistical mechanics. The four types of stress-strain relation and the memory function are derived from this thery. The above theoretical relations are verified by the experimentaf data for various polymer melts. These relations are found to be in good agreement with the experimental results

基于3D Body软件的混合模式在放射肿瘤学教学中的应用

目的分析基于3D Body软件的线上线下混合式模式应用于放射肿瘤学教学中的效果。方法选取两个阶段参与放射肿瘤学教学的实习生,其中2022年1月—12月的32名实习生(对照组)采用传统带教模式;2023年1月—12月的32名实习生(观察组)采用基于3D Body软件的线上线下混合式教学模式,评估两组放射肿瘤学教学效果。结果观察组理论考核、实践操作考核、平时成绩均高于对照组,差异有统计学意义(P<0.05);观察组专业技术(包括靶区勾画、制定计划、计划评估,计划验证)能力评分均高于对照组,差异有统计学意义(P<0.05);观察组评判性思维能力高于对照组,差异有统计学意义(P<0.05);观察组实习生的自我能力评价分值高于对照组,差异有统计学意义(P<0.05);观察组实习生对教学模式满意度评价分值高于对照组,差异有统计学意义(P<0.05)。结论放射肿瘤学教学实践中,相比传统带教模式,基于3D Body软件的线上线下混合式教学模式具有明显改善教学效果、提高实习生专业技术能力与评价满意度的作用。

Rayleigh-type wave propagation in incompressible visco-elastic media under initial stress

Propagation of Rayleigh-type surface waves in an incompressible visco-elastic material over incompressible visco-elastic semi-infinite media under the effect of initial stresses is discussed. The dispersion equation is determined to study the effect of differ- ent types of parameters such as inhomogeneity, initial stress, wave number, phase velocity, damping factor, visco-elasticity, and incompressibility on the Rayleigh-type wave prop- agation. It is found that the affecting parameters have a significant effect on the wave propagation. Cardano＇s and Ferrari＇s methods are deployed to estimate the roots of dif- ferential equations associated with layer and semi-infinite media. The MATHEMATICA software is applied to explicate the effect of these parameters graphically.

Visco-elastic fluid flow past an infinite vertical porous plate in the presence of first-order chemical reaction

An analysis has been developed to study the unsteady free convection flow of an incompressible visco-elastic fluid on a continuously moving vertical porous plate in the presence of a first-order chemical reaction. The governing equations are solved numerically using an implicit finite difference technique. The obtained numerical solutions are compared with the analytical solutions. The velocity profiles are presented. A parametric analysis is performed to illustrate the influences of the visco-elastic parameter, the dimensionless chemical reaction parameter, and the plate moving velocity on the steady state velocity profiles, the time dependent friction coefficient, the Nusselt number, and the Sherwood number.

Experimental study on visco-elastic constitutive relationship and its parameters for geogrids

Geogrids are used as reinforcement materials widely in geotechnical and civil engineering fields. In this paper, a series of comparative tests on creep behavior of specific geoOgrids are conducted in the laboratory under different combinations of loading levels and environmental temperature. Based on the test results,comparative analyses are made to study long-term behaviors of isochronous load-strain curves, creep curves and relaxation curves for the specified geogrids. Furthermore, a constitutive model based on theory of visco-elasticity and tests results is proposed for geogrids and a rational procedure is presented in detail for determining the relevant parameters of the proposed model. Finally, the effect of tests temperature on model parameter values is investigated.

Soft,body conformable electronics for thermoregulation enabled by kirigami

The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.

HEMORRHEOLOGY, VISCO-ELASTICITY AND THIXOTROPY IN CEREBRAL THROMBOSIS

In this study, we used blood rheometer type HT-I to determine blood viscosity, plasma viscosity, hematocrit, blood red cell visco-elasticity and thixotropy in 70 cases with cerebral thrombosis, compared with normal control group in order to study the relationship between their alteration and cerebral thrombosis blood and plasma viscosity were higher in the patients than in normal control. Hysteresis loop analysis showed that the red blood cell’s visco-elasticity, thixotropy and deformity decrease.

Thermal Effect on Free Vibration of Non-Homogeneous Orthotropic Visco-Elastic Rectangular Plate of Parabolically Varying Thickness

A simple model presented here is to study the thermal effect on vibration of non-homogeneous orthotropic visco-elastic rectangular plate of parabolically varying thickness having clamped boundary conditions on all the four edges. For non-homogeneity of the plate material, density is assumed to vary linearly in one direction. Using the separation of variables method, the governing differential equation has been solved for vibration of non-homogeneous orthotropic viscoelastic rectangular plate. An approximate frequency equation is derived by using Rayleigh-Ritz technique with a two-term deflection function. Results are calculated for time period and deflection at different points, for the first two modes of vibration, for various values of temperature gradients, non-homogeneity constant, taper constant and aspect ratio and shown by graphs.