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IMPROVED COHESIVE ZONE MODEL AND ITS APPLICATION IN INTERFACE CONTACT ANALYSIS

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 295-302页

作者： Y. Wang j. Chen H.B. Li National Die ＆ Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030China

An improved interface cohesive zone model is developed for the simulation of interface contact, under mixed-mode loading. A new debonding initiation criterion and propagation of debonding law, taking into account the pressure stress influence on contact shear strength, is proposed. The model is implemented in a finite-element program using subroutine VUINTER of ABAQUS Explicit. An edge-notch four-point bending process and laminated vibration damping steel sheet punch forming test are simulated with the improved model in ABAQUS Explicit. The numerical predictions agree satisfactorily with the corresponding experimental results.

关键词： Cohesive zone model Mixed mode Damage criterion Contact stress

The gluon mass generation mechanism： A concise primer

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Frontiers of physics 2016年第2期11卷 131-148页

作者： A. C. Aguilar D. Binosi j. Papavassilioua University of Campinas (UNICAMP) "Gleb Wataghin" Institute of Physics 13083-859 Campinas SP Brazil European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT^＊) and Fondazione Bruno Kessler Villa Tambosi Strada delle Tabarelle 286 1-38123 Villazzano (TN) Italy Department of Theoretical Physics and IFIC University of Valencia and CSIC E-46100 Valencia Spain

We present a pedagogical overview of the nonperturbative mechanism that endows gluons with a dynamical mass. This analysis is performed based on pure Yang-Mills theories in the Landau gauge, within the theoretical framework that emerges from the combination of the pinch technique with the background field method. In particular, we concentrate on the Schwinger-Dyson equation satisfied by the gluon propagator and examine the necessary conditions for obtaining finite solutions within the infrared region. The role of seagull diagrams receives particular attention, as do the identities that enforce the cancellation of all potential quadratic divergences. We stress the necessity of introducing nonperturbative massless poles in the fully dressed vertices of the theory in order to trigger the Schwinger mechanism, and explain in detail the instrumental role of these poles in maintaining the Becchi-Rouet-Stora-Tyutin symmetry at every step of the mass-generating procedure. The dynamical equation governing the evolution of the gluon mass is derived, and its solutions are determined numerically following implementation of a set of simplifying assumptions. The obtained mass function is positive definite, and exhibits a power law running that is consistent with general arguments based on the operator product expansion in the ultraviolet region. A possible connection between confinement and the presence of an inflection point in the gluon propagator is briefly discussed.

关键词： nonperturbative physics Schwinger-Dyson equations dynamical mass generation

Influence of the velocity barrier on the massive Dirac electron transport in a monolayer MoS2 quantum structure

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Frontiers of physics 2020年第3期15卷 113-121页

作者： X.-j.Hao R.-Y.Yuan j.-j.j.n Y.Guo Center for Theoretical Physics Department of PhysicsCapital Normal UniversityBeijing100048China Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics Tsinghua UniversityBeijing100084China Collaborative Innovation Center of Quantum Matter BeijingChina

Using the transfer matrix method,spin-and valley-dependent electron transport properties modulated by the velocity barrier were studied in the normal/ferromagnetic/normal monolayer MoS2 quantum *** on Snell’s law in optics,we define the velocity barrier asξ=v2/v1 by changing the Fermi velocity of the intermediate ferromagnetic region to obtain a deflection condition during the electron transport process in the *** results show that both the magnitude and the direction of spin-and valley-dependent electron polarization can be regulated by the velocity barrier.−100%polarization of spin-and valley-dependent electron can be achieved forξ>1,while 100%polarization can be obtained forξ<***,it is determined that perfect spin and valley transport always occur at a large incident *** addition,the spin-and valley-dependent electron transport considerably depends on the length kFL and the gate voltage U(x)of the intermediate ferromagnetic *** findings provide an effective method for designing novel spin and valley electronic devices.

关键词： velocity barrier monolayer MoS2 spin valley polarization

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冰冻对纤维角质化的影响

北京林业大学学报 2007年第1期29卷 128-130页

作者：宋先亮 Kwei-Nam law Claude Daneault 殷宁北京林业大学材料科学与技术学院加拿大魁北克大学三河分校制浆造纸中心

为了解冰冻对纤维的影响,该文研究了冰冻处理后纤维形态、保水值及性能的变化.研究结果表明,硫酸盐浆、酸性亚硫酸盐浆、氢氧化钠浆经冰冻处理后,浆料的保水值都明显下降,商品硫酸盐浆的游离度大幅度升高,抄造成的纸张紧度降低,光散射... 详细信息

为了解冰冻对纤维的影响,该文研究了冰冻处理后纤维形态、保水值及性能的变化.研究结果表明,硫酸盐浆、酸性亚硫酸盐浆、氢氧化钠浆经冰冻处理后,浆料的保水值都明显下降,商品硫酸盐浆的游离度大幅度升高,抄造成的纸张紧度降低,光散射系数升高,抗张指数、耐破指数、耐折度明显下降;纤维的长度基本没有变化,弯曲指数和扭结指数有所增加,表明纤维发生了角质化;并提出了冰冻引起纤维角质化的机理.

关键词：冰冻角质化保水值机理

Bridging gap between agro-industrial waste, biodiversity and mycelium-based biocomposites: Understanding their properties by multiscale methodology

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j.urnal of Bioresources and Bioproducts 2024年第4期9卷 495-507页

作者： Isabel Enriquez-Medina isaac Rodas-Ortiz Isabella Bedoya-Garcia AnaMaria Velasquez-Godoy Carlos Alvarez-Vasco Andres Ceballos Bermudez Department of Biological Sciences Bioprocesses and BiotechnologyUniversidad ICESICali 760031Colombia Centro BioInc Universidad ICESI.Cali 760031Colombia

A multiscale methodology approach was employed integrating microscopic analysis of the biomasses present in the biocomposite (lignocellulosic and fungal) to understand their macro- scopic response in terms of physical and mechanical properties. Colombian native strain Gano- derma gibbosum , used for the first time in the production of biocomposites was cultivated on peach palm fruit peel flour and sugar cane bagasse wet dust, individually and as a mixture. During the solid-state fermentation were monitoring the change that occurred in substrate composition such as glucan, arabinoxylan, and lignin through biomass compositional analysis using structural car- bohydrates and lignin. Moreover, fungal biomass formation was monitored via scanning electron microscopy. The resulting biocomposites underwent characterization through flexural and water absorption tests. Our findings indicated that G. gibbosum primarily degraded the polysaccharides in each of the evaluated media. However, lignin degradation to 15.06 g/g was only observed in the mixture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1 ꞉1, accompanied by a reduction in glucan and arabinoxylan weights to 26.1 and 7.72 g/g, respectively. This polymer degradation, combined with a protein-rich source in the mix- ture biocomposite of peach palm fruit peel fluor and sugarcane bagasse wet dust in a ratio of 1 ꞉1, facilitated the production of a fungal skin (biological matrix) with a high hyphal density of 65%, contributing to Young’s modulus of 3.83 MPa, elongation without failure, and low wa- ter absorption rate in this biocomposite (55%). The lignocellulosic biomass in the culture media acted as a filler for mechanical interlocking with the matrix and provided attachment points for water absorption. Thus, our study establishes a connection between the microscopic scale and the macroscopic behavior of this biocomposite, assessing structural carbohydrates and lignin analy- sis du

关键词： Mycelium-based composites Multiscale approach Ganoderma gibbosum Biomass analysis Lignocellulosic biomass Mechanical properties

Photolysis of hexamethylenediaminetetra(methylenephosphonic acid)(HDTMP)using manganese and hydrogen peroxide

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Emerging Contaminants 2020年第1期6卷 10-19页

作者： Ramona Kuhn isaac Mbir Bryant Robert j.nsch Stephan Liebsch Marion Martienssen Brandenburg University of Technology Cottbus-Senftenberg Institute of Environmental Technology and Process EngineeringChair of Biotechnology of Water Treatment03046CottbusGermany University of Cape Coast Department of Environmental ScienceCape CoastGhana Zschimmer&Schwarz Mohsdorf GmbH&Co KG Chemnitztalstr.109217BurgstoadtGermany

Aminophosphonates such as hexamethylenediaminetreta(methylene phosphonic acid)(HDTMP)are categorised as persistent *** are commonly used as scale inhibitors in cooling water systems and desalination *** utilisation,they are often discharged into aquatic environment without *** oxidation processes(AOP)are promising pre-treatments for industrial wastewater *** investigated the photodegradation of HDTMP with or without addition of manganese(Mn2t)and/or *** to results of our former photodegradation studies,we found that HDTMP also undergoes conversion with or without additives during the ultra violet(UV)*** reaction rate was most affected by the addition of H2O2,*** HDTMP degradation was accelerated by a factor 3.85 compared with UV treatment without *** addition of Mn2t accelerated the degradation of HDTMP only by a factor 1.53 compared with the UV treatment without *** combined addition of Mn2t and H2O2 accelerated the HDTMP degradation by a factor ***,the initial cleavage is not initiated as expected at the CeN bond but at the CeP bond of the methyl carbon and the phosphorus of the methylenephosphonic acid group of *** initial cleavage was independent whether the UV treatment was performed with or without ***,we conclude that the degradation mechanism is similar independent of the four tested treatment *** identified amino(methylenephosphonic acid)AMPA,dimethylamino(methylenephosphonic acid)DAMP and iminodi(methylenephosphonic acid)IDMP as the maj.r breakdown products by performing LC/MS *** maj.r mineralisation products were ortho-phosphate,ammonium and carbon *** mass balances of unknown breakdown products allowed us to speculate about the molecular size of the unknown organic breakdown products.

关键词： HDTMP Hydrogen peroxide Manganese LC/MS Phosphonates Photolysis

Metabolic syndrome: a risk factor for high intraocular pressure in the Israeli population

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International j.urnal of Ophthalmology(English edition) 2015年第2期8卷 403-406页

作者： Tamara Wygnanski-j.ffe Itzhak Bieran Dorit Tekes-Manova Yair Morad isaac Ashkenazi Eedy Mezer Goldshlager Eye Institute Sackler School of Medicine Tel Aviv University Sheba Medical Center Department of Alberto Moscona Ophthalmology Rambam Health Care Campus Faculty of Ruth and Bruce Rappaport Medicine Technion-Israel Institute of Technology Medical Corps Headquarters Israel Defense Forces

AIM: To evaluate the association among elevated intraocular pressure(IOP), the metabolic syndrome(Met S), body mass index(BMI), and some of their components in the Israeli ***: We retrospectively reviewed the charts of12 747 soldiers of the Israeli Defense Forces, aged 35 y or older, who underwent a routine periodical medical examination between 1991 and 2004. None of the subj.cts received medical treatment for either glaucoma or ocular hypertension. High IOP(>21 mm Hg) was correlated with age, sex, arterial blood pressure, total blood cholesterol levels, triglyceride levels, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, smoking, BMI and Met ***: A statistically significant difference was found between the IOP of subj.cts with a low risk and higher risk for the development of Met S(P j.cts between high BMI and elevated IOP(r =0.11677, P j.cts with increased IOP levels. We suggest that both should be taken into consideration in the assessment of glaucoma suspects.

关键词： glaucoma body mass index Metabollic syndrome

TNF<i>α</i>and IL1<i>β</i>Stimulate Differential Gene Expression in Endometrial Stromal Cells

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Advances in Biological Chemistry 2015年第2期5卷 126-141页

作者： Abha j. Chalpe Chad D. law j.nnifer N. Dumdie Keith A. Hansen Kathleen M. Eyster Division of Basic Biomedical Sciences Sanford School of Medicine The University of South Dakota Vermillion SD USA Department of Obstetrics and Gynecology Sanford School of Medicine The University of South Dakota Sioux Falls SD USA

The purpose of this study was to test the hypothesis that specific macrophage-secreted cytokines cause gene expression changes in endometrial stromal cells that reproduce the effects of macro-phages in the development of endometriosis. Telomerase-immortalized human endometrial stromal cells (T-HESC) were treated with tumor necrosis factor α (TNFα, 5 ng/ml) and interleukin 1β (IL1β, 1 ng/ml). Differential expression of 249 genes was identified by DNA microarray. Ontologies such as peptidases, cell adhesion, cell death/cell cycle, growth factors, cytoskeletal organization, defense/immune system, signal transduction, and transcriptional regulation which are related to the development of endometriosis were represented by these genes. The up-regulation of interleukin 8 (IL8), interleukin 6 (IL6), IL1β and matrix metallopro-teinase 3 (MMP3) in response to TNFα ± ILIβ in T-HESC cells was confirmed by real time RT-PCR. TNFα ± ILIβ did not affect the migration or invasion of T-HESC cells. This study reinforces our previous investigations on communication between cells of the immune system and endometrial stromal cells and their potential role in the development of endometriosis.

关键词： Cytokines Endometriosis Endometrium Endometrial Stromal Cells Microarray Gene Expression

Preliminary nitrite, nitrate and colour analysis of Malaysian edible bird’s nest

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Information Processing in Agriculture 2015年第1期2卷 1-5页

作者： Meei Chien Quek Nyuk Ling Chin Yus Aniza Yusof Sheau Wei Tan Chung Lim law Department of Process and Food Engineering Faculty of EngineeringUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Laboratory of Vaccines and Immunotherapeutics Institute of BioscienceUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Department of Chemical Engineering Faculty of EngineeringUniversity of NottinghamMalaysia CampusJalan Broga43500 SemenyihSelangorMalaysia

The high nitrite content in edible bird’s nests is a maj.r concern to the local swiftlet *** lowers the price of the edible bird’s nests and it brings severe health hazards to consumers and *** research investigated the nitrite and nitrate contents of eight types of local edible bird’s nests by using ion chromatography system and evaluating its colour using the CIE system in L^*a^*b^**** nitrite content obtained ranged from 5.7 lg/g for the house nests to 843.8 lg/g for the cave *** nitrate content for the house and cave nests was 98.2 lg/g and 36,999.4 lg/g,*** cave nests with darker and redder colour had higher nitrite and nitrate contents than the brighter and more yellow house *** likely suggests that the nitrite and nitrate contents have correlations with edible bird’s nests *** studies suggested that the nitrite content had high correlations with colour parameters,L^*a^*b^*of edible bird’s nests at significant level of P<*** findings suggest that edible bird’s nests’colour may be a useful indicator for measuring nitrite and nitrate contaminations.

关键词： Nitrite Nitrate Colour Ion chromatography Edible bird’s nest