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Review of the damage mechanism in wind turbine gearbox bearings under rolling contact fatigue

Yun-Shuai SU, Shu-Rong YU, Shu-Xin LI, Yan-Ni HE

《机械工程前沿（英文）》 2019年 第14卷 第4期   页码 434-441 doi: 10.1007/s11465-018-0474-1

摘要： Wind turbine gearbox bearings fail with the service life is much shorter than the designed life. Gearbox bearings are subjected to rolling contact fatigue (RCF) and they are observed to fail due to axial cracking, surface flaking, and the formation of white etching areas (WEAs). The current study reviewed these three typical failure modes. The underlying dominant mechanisms were discussed with emphasis on the formation mechanism of WEAs. Although numerous studies have been carried out, the formation of WEAs remains unclear. The prevailing mechanism of the rubbing of crack faces that generates WEAs was questioned by the authors. WEAs were compared with adiabatic shear bands (ASBs) generated in the high strain rate deformation in terms of microstructural compositions, grain refinement, and formation mechanism. Results indicate that a number of similarities exist between them. However, substantial evidence is required to verify whether or not WEAs and ASBs are the same matters.

关键词： rolling contact fatigue (RCF)     white etching area (WEA)     white etching crack (WEC)     adiabatic shear band (ASB)    

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Self-etching adhesives: possible new pulp capping agents to vital pulp therapy

null

《医学前沿（英文）》 2011年 第5卷 第1期   页码 77-79 doi: 10.1007/s11684-010-0104-8

摘要：

Pulp capping is one of the solving for keeping vital pulp in the case of dentin caries, reversible pulpitis or traumatic pulp exposure. The presence of bacteria on the cavity walls or in the pulp was the major factor that leads to the failure of pulp capping. Traditional pulp capping agent, calcium hydroxide, may not prevent microleakage. Self-etching system is a newly developed adhesive system, which could provide less microleakage and would not break down or dissolve, preventing the oral fluids and bacteria from the pulp along the cavity wall. This may reduce such clinical problems as postoperative sensitivity, secondary caries and marginal discoloration. Researches showed that some kinds of self-etching adhesives induced the mild to moderate inflammatory pulp response, with negative bacterial staining. Inclusion of antibacterial components into self-etching system, such as 12- methacryloyloxydodecylpyridinium bromide (MDPB) may inhibit bacteria and provide better clinical effects. It is speculated that using the self-etching adhesive system containing the antibacterial agent, such as MDPB, to the dental pulp directly or indirectly, may inhibit bacteria after the placement of restoration as well as residual bacteria in the cavity.

关键词： dental pulp     pulp capping     self-etching adhesives     antibacterial components    

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Low-k integration: Gas screening for cryogenic etching and plasma damage mitigation

Romain Chanson, Remi Dussart, Thomas Tillocher, P. Lefaucheux, Christian Dussarrat, Jean François de Marneffe

《化学科学与工程前沿（英文）》 2019年 第13卷 第3期   页码 511-516 doi: 10.1007/s11705-019-1820-5

摘要： The integration of porous organo-silicate low- materials has met a lot of technical challenges. One of the main issues is plasma-induced damage, occurring for all plasma steps involved during interconnects processing. In the present paper, we focus on porous SiOCH low- damage mitigation using cryogenic temperature so as to enable micro-capillary condensation. The aim is to protect the porous low- from plasma-induced damage and keep the -value of the material unchanged, in order to limit the RC delay of interconnexion levels while shrinking the microchip dimension. The cryogenic temperature is used to condense a gas inside the porous low- material. Then, the etching process is performed at the temperature of condensation in order to keep the condensate trapped inside the material during the etching. In the first part of this work, the condensation properties of several gases are screened, leading to a down selection of five gases. Then, their stability into the porous structure is evaluated at different temperature. Four of them are used for plasma damage mitigation comparison. Damage mitigation is effective and shows negligible damage for one of the gases at –50°C.

关键词： low-k     nanotechnology     micro-electronics     cryo-etching     plasma processing    

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Loss of monocarboxylate transporter 1 aggravates white matter injury after experimental subarachnoid

《医学前沿（英文）》 2021年 第15卷 第6期   页码 887-902 doi: 10.1007/s11684-021-0879-9

摘要： Monocarboxylic acid transporter 1 (MCT1) maintains axonal function by transferring lactic acid from oligodendrocytes to axons. Subarachnoid hemorrhage (SAH) induces white matter injury, but the involvement of MCT1 is unclear. In this study, the SAH model of adult male Sprague-Dawley rats was used to explore the role of MCT1 in white matter injury after SAH. At 48 h after SAH, oligodendrocyte MCT1 was significantly reduced, and the exogenous overexpression of MCT1 significantly improved white matter integrity and long-term cognitive function. Motor training after SAH significantly increased the number of ITPR2+SOX10+ oligodendrocytes and upregulated the level of MCT1, which was positively correlated with the behavioral ability of rats. In addition, miR-29b and miR-124 levels were significantly increased in SAH rats compared with non-SAH rats. Further intervention experiments showed that miR-29b and miR-124 could negatively regulate the level of MCT1. This study confirmed that the loss of MCT1 may be one of the mechanisms of white matter damage after SAH and may be caused by the negative regulation of miR-29b and miR-124. MCT1 may be involved in the neurological improvement of rehabilitation training after SAH.

关键词： microRNAs     monocarboxylate transporter 1     motor training     subarachnoid hemorrhage     white matter injury    

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Production of a polyclonal antibody to the VP26 nucleocapsid protein of white spot syndrome virus (wssv

Suchera LOYPRASERT-THANANIMIT, Akrapon SALEEDANG, Proespichaya KANATHARANA, Panote THAVARUNGKUL, Wilaiwan CHOTIGEAT

《化学科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 216-223 doi: 10.1007/s11705-012-1289-y

摘要： White spot syndrome virus (WSSV) is a major cause of high mortality in cultured shrimp all over the world. VP26 is one of the structural proteins of WSSV that is assumed to assist in recognizing its host and assists the viral nucleocapsid to move toward the nucleus of the host cell. The objective of this work was to produce a polyclonal antibody against VP26 and use it as a biosensor. The recombinant VP26 protein (rVP26) was produced in (BL21), purified and used for immunizing rabbits to obtain a polyclonal antibody. Western blot analysis confirmed that the antiserum had a specific immunoreactivity to the VP26 of WSSV. This VP26 antiserum was immobilized onto a gold electrode for use as the sensing surface to detect WSSV under a flow injection system. The impedance change in the presence of VP26 was monitored in real time. The sensitivity of the biosensor was in the linear range of 160–160000 copies of WSSV, indicating that it is good and sensitive for analysis of WSSV. The specificity of the biosensor was supported by the observation that no impedance change was detected even at high concentrations when using Yellow Head Virus (YHV). This biosensor may be applied to monitor the amount of WSSV in water during shrimp cultivation.

关键词： recombinant protein     polyclonal antibody     label-free biosensor     impedance     white spot syndrome virus (WSSV)    

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A chemical etching route to controllable fabrication of TiO

Weixin ZHANG, Jie XING, Zeheng YANG, Mei KONG, Hongxu YAO

《化学科学与工程前沿（英文）》 2013年 第7卷 第2期   页码 192-201 doi: 10.1007/s11705-013-1319-4

摘要： The TiO hollow nanospheres with diameters of about 230 nm were prepared by a simple and controllable route based on hydrolysis of Ti(OBu) on the surfaces of the Cu O solid nanospheres followed by inward etching of the Cu O nanospheres. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The further post-heat treatment led to the high crystallization of the TiO hollow nanospheres. The photocatalytic performances of these samples were evaluated for the photodegradation of rhodamine B (RhB) under UV-light irradiation. The as-prepared TiO hollow nanospheres showed higher photocatalytic activity than the CuO and the CuO/TiO hollow nanospheres. Effects of temperature and time for post-heat treatment of TiO as well as initial RhB concentrations on the RhB photodegradation have also been studied. The results show that the TiO hollow nanospheres have the good reusability as photocatalysts and are promising in waste water treatment.

关键词： TiO2     hollow nanospheres     rhodamine B     photocatalytic activity    

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A microarray study of altered gene expression during melanoblasts migration in normal pigmented White

Yulin LI,Deping HAN,Junying LI,Dawn KOLTES,Xuemei DENG

《农业科学与工程前沿（英文）》 2014年 第1卷 第4期   页码 299-306 doi: 10.15302/J-FASE-2014040

摘要： Melanoblasts originating from neural crest cells can migrate through the mesenchyme of the developed embryo and give rise to melanocytes. Unlike the melanocytes that are confined to the integument in other vertebrates, melanocytes in Silky Fowl can reach the ventral regions of the embryos owing to differences in gene expression in the process of melanoblasts migration. In this study, we used microarray profiling to identify differences in gene expression between White Leghorn and Silky Fowl. Differential expression of 2517 microarray probes ( <0.01, Fold Change>2) was observed in Silky Fowl compared to White Leghorn. After filtration by cluster analysis, functional annotation and pathway analysis, eight differentially expressed genes were identified to be closely related to the development of melanocytes. Moreover, differences in expression of immune genes were also detected between Silky Fowl and White Leghorn. The differentially expressed genes associated with melanocyte development were verified by q-PCR, and results were highly consistent with the microarray data. The genes with significantly altered expression involved in melanoblast migration and development suggested that different microenvironments resulted in the abnormal melanoblast migration in Silky Fowl, although there were no big differences in melanoblast development between these two breeds. The candidate genes discovered in this study are beneficial to understand the molecular mechanism of hyperpigmentation in Silky Fowl.

关键词： Silky Fowl     White Leghorn     melanoblast migration     gene expression    

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Dynamic crack propagation in plates weakened by inclined cracks: an investigation based on peridynamics

A. SHAFIEI

《结构与土木工程前沿（英文）》 2018年 第12卷 第4期   页码 527-535 doi: 10.1007/s11709-018-0450-1

摘要： Peridynamics is a theory in solid mechanics that uses integral equations instead of partial differential equations as governing equations. It can be applied to fracture problems in contrast to the approach of fracture mechanics. In this paper by using peridynamics, the crack path for inclined crack under dynamic loading were investigated. The peridynamics solution for this problem represents the main features of dynamic crack propagation such as crack bifurcation. The problem is solved for various angles and different stress values. In addition, the influence of geometry on inclined crack growth is studied. The results are compared with molecular dynamic solutions that seem to show reasonable agreement in branching position and time.

关键词： peridynamics     inclined crack     dynamic fracture     crack branching    

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control of structural responses using an optimal passive tuned mass damper under stationary Gaussian white

Min-Ho CHEY, Jae-Ung KIM

《结构与土木工程前沿（英文）》 2012年 第6卷 第3期   页码 267-280 doi: 10.1007/s11709-012-0170-x

摘要： In this study, the structural control strategy utilizing a passive tuned mass damper (TMD) system as a seismic damping device is outlined, highlighting the parametric optimization approach for displacement and acceleration control. The theory of stationary random processes and complex frequency response functions are explained and adopted. For the vibration control of an undamped structure, the optimal parameters of a TMD, such as the optimal tuning frequency and optimal damping ratio, to stationary Gaussian white noise acceleration are investigated by using a parametric optimization procedure. For damped structures, a numerical searching technique is used to obtain the optimal parameters of the TMD, and then the explicit formulae for these optimal parameters are derived through a sequence of curve-fitting schemes. Using these specified optimal parameters, several different controlled responses are examined, and then the displacement and acceleration based control effectiveness indices of the TMD are examined from the view point of RMS values. From the viewpoint of the RMS values of displacement and acceleration, the optimal TMDs adopted in this study shows clear performance improvements for the simplified model examined, and this means that the effective optimization of the TMD has a good potential as a customized target response-based structural strategy.

关键词： tuned mass damper     parametric optimization     passive control     white noise     earthquake excitation    

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结合选择性和数字湿法腐蚀的InAlAs/InGaAs InP基HEMTs两步栅槽腐蚀工艺 Article

Ying-hui ZHONG, Shu-xiang SUN, Wen-bin WONG, Hai-li WANG, Xiao-ming LIU, Zhi-yong DUAN, Peng DING, Zhi JIN

《信息与电子工程前沿（英文）》 2017年 第18卷 第8期   页码 1180-1185 doi: 10.1631/FITEE.1601121

摘要： 本文针对InAlAs/InGaAs InP基高电子迁移率晶体管（HEMTs）提出了一种结合高选择性湿法腐蚀和非选择性数字湿法腐蚀的两步栅槽腐蚀工艺。通过采用丁二酸和双氧水（H2O2）混合溶液，InGaAs与InAlAs材料的腐蚀选择比可以超过100。该选择性湿法腐蚀工艺在InAlAs/InGaAs InP基HEMTs栅槽工艺中得到了很好的验证，栅槽腐蚀会自动终止在InAlAs势垒层。本文通过分离氧化/去氧化过程开发了非选择性数字湿法腐蚀工艺，每个周期能除去1.2 nm InAlAs材料。最终，两步栅槽腐蚀工艺被成功用于器件制备中，数字湿法腐蚀重复两个周期去掉约3 nm InAlAs势垒层材料。通过该方法制备的InP基HEMTs器件比只依靠选择性湿法腐蚀栅槽工艺制备出的器件具有更短的栅沟间距，表现出更好的有效跨导和射频特性。

关键词： 高电子迁移率晶体管（High electron mobility transistors     HEMTs）；栅槽；数字湿法腐蚀；选择性湿法腐蚀    

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Peridynamics versus XFEM: a comparative study for quasi-static crack problems

Jinhai ZHAO, Hesheng TANG, Songtao XUE

《结构与土木工程前沿（英文）》 2018年 第12卷 第4期   页码 548-557 doi: 10.1007/s11709-017-0434-6

摘要： Peridynamics (PD) is a nonlocal continuum theory based on integro-differential equations without spatial derivatives. The fracture criterion is implicitly incorporated in the PD theory and fracture is a natural outcome of the simulation. However, capturing of complex mixed-mode crack patterns has been proven to be difficult with PD. On the other hand, the extended finite element method (XFEM) is one of the most popular methods for fracture which allows crack propagation with minimal remeshing. It requires a fracture criterion which is independent of the underlying discretization though a certain refinement is needed in order to obtain suitable results. This article presents a comparative study between XFEM and PD. Therefore, two examples are studied. The first example is crack propagation in a double notched specimen under uniaxial tension with different crack spacings in loading direction. The second example is the specimens with two center cracks. The results show that PD as well as XFEM are well suited to capture this type of behaviour.

关键词： XFEM     peridynamic     bilateral crack     parallel double cracks     nonlocal theory    

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Correlation between tension softening relation and crack extension resistance in concrete

Xiufang ZHANG , Shilang XU ,

《结构与土木工程前沿（英文）》 2009年 第3卷 第3期   页码 323-329 doi: 10.1007/s11709-009-0041-2

摘要： Changes of the material fracture energy consumption with crack propagation can be described by a crack extension resistance curve, one of the fundamental fracture criteria in crack mechanics. Recently, experimental observation of the fracture behavior in concrete was used to develop a new fracture criterion, the crack extension resistance curve, to analyze crack propagation during the entire concrete fracture process. The variation of the crack extension resistance is mainly associated with the energy consumption in the fracture process zone ahead of the stress-free crack tip. The crack extension resistance is then a function of the softening curve, which is a basic mechanical property in the fracture process zone. The relationship between the softening curve and the crack extension resistance curve is then analyzed based on results of three-point bending beams tests. The results indicate that the characteristic points of the crack extension resistance curve is closely related to the characteristic point on used tension softening curve.

关键词： concrete     fracture process zone     crack extension GR resistance     tension softening curve    

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Fracture resistance on aggregate bridging crack in concrete

ZHANG Xiufang, XU Shilang

《结构与土木工程前沿（英文）》 2007年 第1卷 第1期   页码 63-70 doi: 10.1007/s11709-007-0006-2

摘要： Fracture toughening exhibited in quasi-brittle materials such as concrete is often mainly related to the action of aggregate bridging, which leads to the presence of a fracture process zone ahead of stress-free cracks in such materials. In this investigation, the fracture resistance induced by aggregate bridging, denoted by GI-bridging, is the primary focus. In order to quantitatively determine it, a general analytical formula is firstly developed, based on the definition of fracture energy by Hillerborg. After this, we further present the calculated procedures of determining this fracture resistance from the recorded load vs. crack opening displacement curve. Then, both numerical simulations and fracture experiments are performed on concrete three-point bending beams. Utilizing the obtained load against crack opening displacement curve, the value of G at any crack extension as well as the change of G with the crack extension is examined. It is found that G will firstly increase with the development of crack and then stay constant once the initial crack tip opening displacement reaches the characteristic crack opening displacement w0. The effects of material strength and specimen depth on this fracture resistance are also investigated. The results reveal that the values of G of different specimens at any crack propagation are strongly associated with the values of fracture energy of specimens. If the values of fracture energy between different specimens are comparable, the differences between G are ignored. Instead, if values of fracture energy are different, the G will be different. This shows that for specimens with different strengths, G will change greatly whereas for specimens that are different in depth, whether GI-bridging exhibits size effect depends on whether the fracture energy of specimens considered in the calculation of G is assumed to be a size-dependent material parameter.
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Stability and dynamics of rotor system with 45° slant crack on shaft

Yanli LIN, Xiaohui SI, Fulei CHU

《机械工程前沿（英文）》 2011年 第6卷 第2期   页码 203-213 doi: 10.1007/s11465-011-0131-4

摘要：

Crack on a shaft is one of the common damages in a rotor system. In this paper, transverse vibrations are calculated to compare the influences of transverse crack and slant crack on the rotor system. Results show that the vibration amplitude of the rotor system with a 45° slant crack on the shaft is larger than that with a transverse crack when the two types of crack have the same depth and the rotor system runs in the same condition. Stability and dynamic characteristics of the rotor system with a 45° slant crack on the shaft under torsional excitation are analyzed by considering opening and closing of the crack. It is shown that the instability of the transverse vibration of the rotor system increases with increasing difference between the bending stiffness in two main directions, and the vibration is stable when the two bending stiffness are identical. The spectrum analysis of the steady-state response reveals that the gravity and the eccentricity produce different frequency components, and when the two bending stiffness are identical, the multiple frequency components of the torsional excitation disappear. Further investigation shows that the vibration amplitudes in combined frequencies increase rapidly in transversal, torsional, and axial vibration with increasing slant crack depth. The results are helpful for the understanding the dynamic behavior of a rotor system with a slant crack on a shaft and can be used for the detection of the slant crack on a shaft.

关键词： rotor dynamics     slant crack     stability     torsional excitation     open and close    

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reduces IgE binding ability of allergenic egg white proteins

Sen LI, Marina OFFENGENDEN, Michael G. GÄNZLE, Jianping WU

《农业科学与工程前沿（英文）》 2018年 第5卷 第3期   页码 373-381 doi: 10.15302/J-FASE-2018210

摘要：

Egg white proteins are one of the major allergens. The objective of this study was to investigate the effect of Aspergillus oryzae cultivation on IgE binding ability of egg white proteins. Effect of A. oryzae on egg white proteins was determined using ninhydrin method, SDS-PAGE, ELISA, fluorescence FITC labeling, MALDI-TOF-MS and LC-MS/MS analysis. Adding mycelium of A. oryzae ATCC 1011 and 16868 substantially reduced the IgE binding ability of acidified egg white after 24 h incubation. The binding capacity of egg white proteins to IgE in plasma from four egg allergy patients was almost completely lost after incubation with mycelium of ATCC 16868. Results from SDS-PAGE, free amino acid analysis, MALDI-TOF-MS and LC-MS/MS indicated that there was no substantial protein degradation during incubation. Therefore, the reduction of IgE binding ability of egg white proteins during A. oryzae treatment was probably due to a loss of ~1700 Da mass including a fragment of the ovomucoid N terminus.

关键词： Aspergillus oryzae     egg allergy     egg white proteins     IgE-binding ability     ovomucoid    

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标题 作者 时间 类型 操作

Review of the damage mechanism in wind turbine gearbox bearings under rolling contact fatigue

Yun-Shuai SU, Shu-Rong YU, Shu-Xin LI, Yan-Ni HE

期刊论文

Self-etching adhesives: possible new pulp capping agents to vital pulp therapy

null

期刊论文

Low-k integration: Gas screening for cryogenic etching and plasma damage mitigation

Romain Chanson, Remi Dussart, Thomas Tillocher, P. Lefaucheux, Christian Dussarrat, Jean François de Marneffe

期刊论文

Loss of monocarboxylate transporter 1 aggravates white matter injury after experimental subarachnoid

期刊论文

Production of a polyclonal antibody to the VP26 nucleocapsid protein of white spot syndrome virus (wssv

Suchera LOYPRASERT-THANANIMIT, Akrapon SALEEDANG, Proespichaya KANATHARANA, Panote THAVARUNGKUL, Wilaiwan CHOTIGEAT

期刊论文

A chemical etching route to controllable fabrication of TiO

Weixin ZHANG, Jie XING, Zeheng YANG, Mei KONG, Hongxu YAO

期刊论文

A microarray study of altered gene expression during melanoblasts migration in normal pigmented White

Yulin LI,Deping HAN,Junying LI,Dawn KOLTES,Xuemei DENG

期刊论文

Dynamic crack propagation in plates weakened by inclined cracks: an investigation based on peridynamics

A. SHAFIEI

期刊论文

control of structural responses using an optimal passive tuned mass damper under stationary Gaussian white

Min-Ho CHEY, Jae-Ung KIM

期刊论文

结合选择性和数字湿法腐蚀的InAlAs/InGaAs InP基HEMTs两步栅槽腐蚀工艺

Ying-hui ZHONG, Shu-xiang SUN, Wen-bin WONG, Hai-li WANG, Xiao-ming LIU, Zhi-yong DUAN, Peng DING, Zhi JIN

期刊论文

Peridynamics versus XFEM: a comparative study for quasi-static crack problems

Jinhai ZHAO, Hesheng TANG, Songtao XUE

期刊论文

Correlation between tension softening relation and crack extension resistance in concrete

Xiufang ZHANG , Shilang XU ,

期刊论文

Fracture resistance on aggregate bridging crack in concrete

ZHANG Xiufang, XU Shilang

期刊论文

Stability and dynamics of rotor system with 45° slant crack on shaft

Yanli LIN, Xiaohui SI, Fulei CHU

期刊论文

reduces IgE binding ability of allergenic egg white proteins

Sen LI, Marina OFFENGENDEN, Michael G. GÄNZLE, Jianping WU

期刊论文