Bright and dark small amplitude nonlinear localized modes in a quantum one-dimensional Klein--Gordon chain

By means of the Glauber＇s coherent state method combined with multiple-scale method, this paper investigates the localized modes in a quantum one-dimensional Klein-Gordon chain and finds that the equation of motion of annihilation operator is reduced to the nonlinear Schroedinger equation. Interestingly, the model can support both bright and dark small amplitude travelling and non-travelling nonlinear localized modes in different parameter spaces.     

Measurement of interaction force between RGD-peptide and Hela cell surface by optical tweezers

Since RGD peptides (R: arginine; G: glycine; D: aspartic acid) are found to promote cell adhesion, they are modified at numerous materials surface for medical applications such as drug delivery and regenerative medicine. Peptide-cell surface interactions play a key role in the above applications. In this letter, we study the adhesion force between the RGD-coated bead and Hela cell surface by optical tweezes. The adhesion is dominated by the binding of α5β1 and RGD-peptide with higher adhesion probability and stronger adhesion strength compared with the adhesion of bare bead and cell surface. The binding force for a single α5β1 -GRGDSP pair is determined to be 16.8 pN at a loading rate of 1.5 nN/s. The unstressed off-rate is 1.65 × 10-2s-1 and the distance of transition state for the rigid binding model is 3.0 nm.     

应用正交多项式设计法研究煤的粘附规律

丛茜等．应用正交多项式设计法研究煤的粘附规律．本文对影响煤与工作部件表面法向粘附力的二个主要因素：煤的含水量及所受正压力,进行了正交多项式回归设计,建立了显著的回归方程,并揭示了煤的粘附规律     

Application of subband adaptive filtering techniques to ultrasonic detection in multilayers

The ultrasonic testing for the defects of complete disbond in multi-layered structure with lower acoustic impedance beneath a high acoustic impedance overburden is one of the difficult problems in ultrasonic nondestructive testing field.A model of a multi-layered steel-rubber composite plate is depicted.Because the acoustic impedance of the steel differs far from that of the couplant water and the rubber,the energy of the signal refleccted from the deonded rubber layers is very weak.More over,the flaw echoes are masked by the strong echoes reverberated in the steel plate.It‘s nearly impossible to identify the debonding echoes directly.The subband adaptive filtering method is discussed in the paper,where the subband decomposition is performed by mutual wavelet packets decomposition on the criterion of maximizing the cross-correlation between the signals.The simulations on both synthetic and real signals are presented.The echoes from the delaminated flaw at the depth of 5mm in the rubber from the calculated signal,and echoes from the flaw at the depth of 3mm from the real signal are extracted successfully.     

MICROMECHANICS OF ROUGH SURFACE ADHESION： A HOMOGENIZED PROJECTION METHOD

A quasistatic homogenized projection is made to characterize the effective cohesive zone behavior for rough-surface adhesion. In the context of the homogenized projection, the traction versus separation relation for the homogenized cohesive zone （HCZ） of a rough interface can be highly oscillatory due to instabilities during microscopic adhesion and decohesion processes. The instabilities are found to occur not only individually but also collectively among the adhesive micro-asperity contacts, leading to extensive energy dissipation. Based on the behaviors of the HCZ relations, a framework for describing instability-induced energy dissipation in rough-surface adhesion is proposed to elucidate the effect of roughness on apparent interface adhesion. Two non- dimensional parameters, α related to roughness morphology and n related to flaw distribution, are identified to be most crucial for controlling the energy dissipation. For an interface with a shallow roughness and a strong intrinsic adhesive strength, the interface adhesion can be stronger if we make it rougher （reducing α） or lower its flaw density （increasing n）. The HCZ projection method can be potentially extended and employed to bridge the apparent adhesion from intrinsic adhesion properties for engineering surfaces with multi-scale shallow roughness.     

基于第一性原理的WC-Co(0001)/cBN(111)界面结合性能研究

基于第一性原理方法,建立WC-Co/cBN_4B、WC-Co/cBN_4N、WC-Co/cBN_{1B-near OA}、WC-Co/cBN_{1N-near OA}、WC-Co/cBN_{1N-near OB}和WC-Co/cBN_{1B-near OB}六种界面模型,计算其界面粘附功、断裂韧性。结果表明:WC-Co/cBN_4B界面具有最大粘附功值9.705 J·m^-2,界面最稳定,粘附功大于WC(0001)_w界面的断裂韧性7.824 J·m^-2,裂纹倾向于出现在基体中; WC-Co/cBN_4N界面有最小粘附功4.470 J·m^-2,界面最不稳定,粘附功小于WC(0001)_w界面的断裂韧性,裂纹倾向于出现在界面处。在此基础上,为从电荷转移、成键方式和价电子分布的深层次角度解释界面稳定性,进行了差分电荷密度、态密度和Mulliken...     

高粘附可拉伸高分子材料与高动态稳定人体电生理监测

高动态稳定人体电生理监测在智能可穿戴健康监测、心血管疾病临床诊断、神经系统疾病治疗以及智能人机交互等领域具有广阔的应用前景.作为人与外部环境的信号交互桥梁,皮肤电极可贴合于皮肤表面,以无创的方式监测和采集各种电生理信号,成为高动态稳定电生理监测的理想平台.从材料角度出发,皮肤电极的高动态稳定性决定于基底材料的高粘附性和可拉伸性.因此,如何通过高分子结构的合理设计制备高粘附可拉伸高分子材料,构筑高度共形粘附于人体皮肤表面的电极,从而实现高动态稳定人体电生理监测,是柔性智能健康监测领域的重要研究方向.本文总结了本课题组近年来在高粘附可拉伸高分子材料制备及其在高动态稳定人体电生理监测应用方面的研究进展,并讨论了高粘附可拉伸高分子材料在下一代柔性智能健康监测领域面临的机遇和挑战.     

致病菌与糖的特异性识别及其分析应用研究

致病菌往往通过凝集素-糖特异性识别来实现对宿主细胞的粘附,进而感染宿主组织,引起病变。因此,研究致病菌与糖的特异性识别有利于进一步了解感染性疾病的致病机制,为致病菌的特异性检测和感染性疾病的治疗提供新的策略。该文总结了致病菌-糖特异性识别的相关机制机理;介绍了目前主要的研究方法和技术,特别评述了荧光光谱、表面等离子体共振、电化学阻抗谱及石英晶体微天平等技术在该研究中的应用现状,并对这4种技术与微流控芯片平台的结合进行了探讨;针对致病菌检测特异性差、耐药性严重等难题,重点综述了致病菌-糖的特异性识别在细菌分离、富集、检测、鉴别、生物膜抑制及抗菌糖类药物筛选方面的应用。最后对致病菌-糖特异性识别基础和应用研究进行了展望。     

受限空间内油水界面动态特性及粘附行为的荧光原位观测

水污染作为润滑油污染的常见形式,对润滑油本身以及机械系统都有巨大的危害。为了模拟实际非均匀多相系统中的界面行为,本文搭建了高精度点接触实验台来研究传统的不溶相替换问题。将目前静态平行受限空间内油水界面行为的研究推广到动态点接触楔形受限空间内,探究了游离水滴穿过点接触狭缝间毛细油池过程中的界面特性。重点关注固壁润湿性以及固壁的分离运动对整个侵入过程中液滴动态行为的影响。实验发现了铺展系数是决定油水界面融合和分离特性的关键因素,揭示了固壁润湿性和球盘间的相对分离运动会影响游离水滴穿过毛细油池之后的粘附行为。表面张力和液体与壁面之间的粘附功能够解释观测的实验现象。     

罗伊氏乳杆菌NCU801对病原菌的粘附抑制性能

采用选择性平板计数法,考察罗伊氏乳杆菌NCU801活菌悬液、死菌悬液以及发酵上清液对大肠杆菌CMCC44496和金黄色葡萄球菌26003粘附Caco-2细胞的影响。结果表明:在竞争试验、排斥试验和置换试验中,罗伊氏乳杆菌NCU801活菌悬液和死菌悬液均能抑制大肠杆菌和金黄色葡萄球菌的粘附;活菌悬液比死菌悬液抑制效果更显著,其中最显著的是活菌悬液对大肠杆菌排斥抑制粘附,粘附抑制率达到(86.8±4.5)%;而发酵上清液在竞争实验中最显著,其次是置换试验,而在排斥实验中对病原菌无影响,说明发酵上清液中的细菌素能够杀死未粘附和已粘附的病原菌。更多还原