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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    

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    

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    

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    

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)    

Exploring self-organization and self-adaption for smart manufacturing complex networks

《工程管理前沿(英文)》 2023年 第10卷 第2期   页码 206-222 doi: 10.1007/s42524-022-0225-1

摘要: Trends toward the globalization of the manufacturing industry and the increasing demands for small-batch, short-cycle, and highly customized products result in complexities and fluctuations in both external and internal manufacturing environments, which poses great challenges to manufacturing enterprises. Fortunately, recent advances in the Industrial Internet of Things (IIoT) and the widespread use of embedded processors and sensors in factories enable collecting real-time manufacturing status data and building cyber–physical systems for smart, flexible, and resilient manufacturing systems. In this context, this paper investigates the mechanisms and methodology of self-organization and self-adaption to tackle exceptions and disturbances in discrete manufacturing processes. Specifically, a general model of smart manufacturing complex networks is constructed using scale-free networks to interconnect heterogeneous manufacturing resources represented by network vertices at multiple levels. Moreover, the capabilities of physical manufacturing resources are encapsulated into virtual manufacturing services using cloud technology, which can be added to or removed from the networks in a plug-and-play manner. Materials, information, and financial assets are passed through interactive links across the networks. Subsequently, analytical target cascading is used to formulate the processes of self-organizing optimal configuration and self-adaptive collaborative control for multilevel key manufacturing resources while particle swarm optimization is used to solve local problems on network vertices. Consequently, an industrial case based on a Chinese engine factory demonstrates the feasibility and efficiency of the proposed model and method in handling typical exceptions. The simulation results show that the proposed mechanism and method outperform the event-triggered rescheduling method, reducing manufacturing cost, manufacturing time, waiting time, and energy consumption, with reasonable computational time. This work potentially enables managers and practitioners to implement active perception, active response, self-organization, and self-adaption solutions in discrete manufacturing enterprises.

关键词: cyber–physical systems     Industrial Internet of Things     smart manufacturing complex networks     self-organization and self-adaption     analytical target cascading     collaborative optimization    

旋转体自身驱动的硅微机械陀螺

张福学,毛旭,张伟

《中国工程科学》 2006年 第8卷 第8期   页码 23-27

摘要:

报道了一种利用旋转体自身角速度作为驱动力,通过各向异性刻蚀硅片制作的硅微机械陀螺。介绍了该陀螺敏感结构(硅摆)的设计、制作与封装工艺,用仿真器测试了旋转体的角速率。模拟试验和性能测试表明,该陀螺结构原理正确,可用于敏感旋转体的偏航或俯仰角速度,以及旋转体自身的角速度。

关键词:     各向异性腐蚀     角速度     仿真器    

Emerging trends in self-healable nanomaterials for triboelectric nanogenerators: A comprehensive review

《能源前沿(英文)》   页码 727-750 doi: 10.1007/s11708-023-0896-2

摘要: A thorough analysis of triboelectric nanogenerators (TENGs) that make use of self-healable nanomaterials is presented in this review. These TENGs have shown promise as independent energy sources that do not require an external power source to function. TENGs are developing into a viable choice for powering numerous applications as low-power electronics technology advances. Despite having less power than conventional energy sources, TENGs do not directly compete with these. TENGs, on the other hand, provide unique opportunities for future self-powered systems and might encourage advancements in energy and sensor technologies. Examining the many approaches used to improve nanogenerators by employing materials with shape memory and self-healable characteristics is the main goal of this review. The findings of this comprehensive review provide valuable information on the advancements and possibilities of TENGs, which opens the way for further research and advancement in this field. The discussion of life cycle evaluations of TENGs provides details on how well they perform in terms of the environment and identifies potential improvement areas. Additionally, the cost-effectiveness, social acceptability, and regulatory implications of self-healing TENGs are examined, as well as their economic and societal ramifications.

关键词: triboelectric nanogenerator (TENG)     self-healable nanomaterials     self-powered devices     energy    

Modular structure of a self-reconfigurable robot

FEI Yanqiong, DONG Qinglei, ZHAO Xifang

《机械工程前沿(英文)》 2007年 第2卷 第1期   页码 116-119 doi: 10.1007/s11465-007-0020-z

摘要: This paper proposes a novel, hermaphroditic, and lattice self-reconfigurable modular robot. Each module is composed of a center body a cubic part and six sides that can rotate independently. There are two holes and two extensible pegs on each side. The rotary motion of each side and the extensible motion of the pegs are generated by a motor connected to a reducer, using a cone-shaped gear, belt, clutch, etc. The structure of the module is compact, and has space to extend further.

关键词: compact     self-reconfigurable modular     hermaphroditic     cone-shaped     clutch    

Signal separation technology for diphase opposition giant magnetostrictive self-sensing actuator

Xinhua WANG, Shuwen SUN, Jian ZHEN, Qianyi YA, Deguo WANG,

《机械工程前沿(英文)》 2010年 第5卷 第2期   页码 176-183 doi: 10.1007/s11465-010-0001-5

摘要: The structure and principle of a new type of a diphase opposition giant magnetostrictive self-sensing actuator is introduced. A bridge analysis model based on variable inductance is established. Dynamic balance separation technology for the giant magnetostrictive self-sensing actuator comes true by the least means square (LMS) self-adapting algorithm. The scheme design of one important part of the circuit with the real-time separation circuit of the dynamic balance signal based on a digital signal processor is obtained. The part of the signal separated circuit is designed, which includes logarithmic-antilog practical multiplication circuit, amplifying circuit, filter circuits, and amplifier circuit. Based on the embedded system simulation software—PROTUES, the simulation effect of the circuit that separates the sensing signal from the mixed signals is obvious, which indicates that the circuit can rapidly and stably work. Moreover, the structure is simple, reliable, and meets the practical requirement.

关键词: giant magnetostrictive material (GMM) self-sensing actuator     least means square (LMS) self-adapting algorithm     design of self-adaptive circuit    

Behaviour of self-centring shear walls——A state of the art review

《结构与土木工程前沿(英文)》 2023年 第17卷 第1期   页码 53-77 doi: 10.1007/s11709-022-0850-0

摘要: The application of unbonded post-tensioning (PT) in structural walls has led to the development of advanced self-centring (rocking) shear wall systems that has significant advantages, including accelerated construction due to the incorporation of prefabricated elements and segmental construction for different materials (e.g., concrete, masonry, and timber), reduced residual drifts, and little damage upon extreme seismic and wind loads. Concrete, masonry, and timber are often used for the construction of unbonded PT structural wall systems. Despite extensive research since the 1980s, there are no well-established design guidelines available on the shear wall configuration with the required energy dissipation system, joint’s locations and acceptance criteria for shear sliding, confinement, seismic performance factors, PT loss, PT force range and residual drifts of shear walls subjected to lateral loads. In this research a comprehensive state-of-the-art literature review was performed on self-centring shear wall system. An extensive study was carried out to collect a database of 100 concrete, masonry, and self-centring shear wall tests from the literature. The established database was then used to review shear walls’ configurations, material, and components to benchmark requirements applicable for design purposes. The behaviour of concrete, masonry and timber shear walls were compared and critically analysed. The general behaviour, force-displacement performance of the walls, ductility, and seismic response factors, were critically reviewed and analysed for different self-centring wall systems to understand the effect of different parameters including configurations of the walls, material used for construction of the wall (concrete, masonry, timber) and axial stress ratio. The outcome of this research can be used to better understand the behaviour of self-centring wall system in order to develop design guidelines for such walls.

关键词: self-centring shear walls     rocking walls     energy dissipation     seismic performance factors     PT loss     residual drift    

Recycled glass replacement as fine aggregate in self-compacting concrete

Yasser SHARIFI, Mahmoud HOUSHIAR, Behnam AGHEBATI

《结构与土木工程前沿(英文)》 2013年 第7卷 第4期   页码 419-428 doi: 10.1007/s11709-013-0224-8

摘要: With increasing environmental pressure to reduce solid waste and to recycle as much as possible, the concrete industry has adopted a number of methods to achieve this goal by replacement of waste glass with concrete composition materials. Due to differences in mixture design, placement and consolidation techniques, the strength and durability of Self Compacting Concrete (SCC) may be different than those of conventional concrete. Therefore, replacement of waste glass with fine aggregate in SCC should deeply be investigated compared to conventional concretes. The aim of the present study is to investigate the effect of glass replacement with fine aggregate on the SCC properties. In present study, fine aggregate has been replaced with waste glass in six different weight ratios ranging from 0% to 50%. Fresh results indicate that the flow-ability characteristics have been increased as the waste glass incorporated to paste volume. Nevertheless, compressive, flexural and splitting strengths of concrete containing waste glass have been shown to decrease when the content of waste glass is increased. The strength reduction of concrete in different glass replacement ratios is not remarkable, thus it can be produced SCC with waste glass as fine aggregate in a standard manner.

关键词: Self Compacting Concrete (SCC)     recycle glass     fine aggregate     fresh and hardened properties    

Effect of calcium lactate on compressive strength and self-healing of cracks in microbial concrete

Kunamineni VIJAY, Meena MURMU

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 515-525 doi: 10.1007/s11709-018-0494-2

摘要: This paper presents the effect on compressive strength and self-healing capability of bacterial concrete with the addition of calcium lactate. Compared to normal concrete, bacterial concrete possesses higher durability and engineering concrete properties. The production of calcium carbonate in bacterial concrete is limited to the calcium content in cement. Hence calcium lactate is externally added to be an additional source of calcium in the concrete. The influence of this addition on compressive strength, self-healing capability of cracks is highlighted in this study. The bacterium used in the study is and was added to both spore powder form and culture form to the concrete. spore powder of 2 million cfu/g concentration with 0.5% cement was mixed to concrete. Calcium lactates with concentrations of 0.5%, 1.0%, 1.5%, 2.0%, and 2.5% of cement, was added to the concrete mixes to test the effect on properties of concrete. In other samples, cultured with a concentration of 1×10 cells/mL was mixed with concrete, to study the effect of bacteria in the cultured form on the properties of concrete. Cubes of 100 mm×100 mm×100 mm were used for the study. These cubes were tested after a curing period of 7, 14 and 28 d. A maximum of 12% increase in compressive strength was observed with the addition of 0.5% of calcium lactate in concrete. Scanning electron microscope and energy dispersive X-ray spectroscopy examination showed the formation of ettringite in pores; calcium silicate hydrates and calcite which made the concrete denser. A statistical technique was applied to analyze the experimental data of the compressive strengths of cementations materials. Response surface methodology was adopted for optimizing the experimental data. The regression equation was yielded by the application of response surface methodology relating response variables to input parameters. This method aids in predicting the experimental results accurately with an acceptable range of error. Findings of this investigation indicated the influence of added calcium lactate in bio-concrete which is quite impressive for improving the compressive strength and self-healing properties of concrete.

关键词: calcium lactate     bacillus subtilis     compressive strength     self-healing of cracks    

Computational fluid dynamic analysis of flutter characteristics for self-anchored suspension bridges

ZHU Zhiwen, WANG Zhaoxiang, CHEN Zhengqing

《结构与土木工程前沿(英文)》 2008年 第2卷 第3期   页码 267-273 doi: 10.1007/s11709-008-0034-6

摘要: This paper outlines the essentials and procedures of computational fluid dynamics (CFD) simulation applicable to evaluating flutter derivatives of bridge decks. An arbitrary Lagrangian-Eulerian (ALE) description of the flow around the moving rigid box girder combined with the finite volume discretization and multi-grid algorithm is presented. The proposed methods are employed to identify flutter derivatives of the bridge deck of the Sanchaji Self-anchored Suspension Bridge. The results agree well with ones from wind tunnel tests. It demonstrates accuracy and efficiency of the present method.

关键词: discretization     computational     description     Self-anchored Suspension     simulation applicable    

Effects of solvents and temperature on spherulites of self-assembled phloroglucinol tristearate

Yawen Yao, Sabine Rosenfeldt, Kai Zhang

《化学科学与工程前沿(英文)》 2020年 第14卷 第3期   页码 389-396 doi: 10.1007/s11705-019-1911-3

摘要: Herein, phloroglucinol tristearate (PhgTS) was used to study the crystallization process due to its unique symmetric structure containing a benzene ring and three aliphatic chains. Spherulites of crystallized PhgTS from four solvents under diverse conditions were analyzed in detail and their formation process was studied. Maltese cross is shown by PhgTS spherulites obtained from aprotic solvents via polarized optical microscopy. In comparison, no Maltese cross can be observed from branch-like crystals formed from protic solvents. Independent on the microscaled morphology, lamellae were found to be the basic blocks constructing both PhgTS spherulites and branch-like crystals, which were formed predominantly by stacked PhgTS molecules. Although differential characters of the solvents did not affect the formation of lamellas, the solvents played a crucial role in the formation of self-assembled microscaled morphologies. In particular, the morphologies of spherulites were strongly affected by the concentration of PhgTS solutions, surrounding temperature and evaporation rate of solvents. Generally, a higher concentration of PhgTS led to more homogeneous spherulites, a lower evaporation rate resulted in more compact spherulites, and a higher surrounding temperature generated preferentially more ring-banded spherulites of PhgTS.

关键词: phloroglucinol     tristearate     aprotic and protic solvent     self-assembly     spherulites    

标题 作者 时间 类型 操作

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

A chemical etching route to controllable fabrication of TiO

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

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

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

Exploring self-organization and self-adaption for smart manufacturing complex networks

期刊论文

旋转体自身驱动的硅微机械陀螺

张福学,毛旭,张伟

期刊论文

Emerging trends in self-healable nanomaterials for triboelectric nanogenerators: A comprehensive review

期刊论文

Modular structure of a self-reconfigurable robot

FEI Yanqiong, DONG Qinglei, ZHAO Xifang

期刊论文

Signal separation technology for diphase opposition giant magnetostrictive self-sensing actuator

Xinhua WANG, Shuwen SUN, Jian ZHEN, Qianyi YA, Deguo WANG,

期刊论文

Behaviour of self-centring shear walls——A state of the art review

期刊论文

Recycled glass replacement as fine aggregate in self-compacting concrete

Yasser SHARIFI, Mahmoud HOUSHIAR, Behnam AGHEBATI

期刊论文

Effect of calcium lactate on compressive strength and self-healing of cracks in microbial concrete

Kunamineni VIJAY, Meena MURMU

期刊论文

Computational fluid dynamic analysis of flutter characteristics for self-anchored suspension bridges

ZHU Zhiwen, WANG Zhaoxiang, CHEN Zhengqing

期刊论文

Effects of solvents and temperature on spherulites of self-assembled phloroglucinol tristearate

Yawen Yao, Sabine Rosenfeldt, Kai Zhang

期刊论文