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Materials-oriented integrated design and construction of structures in civil engineering—A review

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 24-44 doi: 10.1007/s11709-021-0794-9

摘要: Design is a goal-oriented planning activity for creating products, processes, and systems with desired functions through specifications. It is a decision-making exploration: the design outcome may vary greatly depending on the designer’s knowledge and philosophy. Integrated design is one type of design philosophy that takes an interdisciplinary and holistic approach. In civil engineering, structural design is such an activity for creating buildings and infrastructures. Recently, structural design in many countries has emphasized a performance-based philosophy that simultaneously considers a structure’s safety, durability, serviceability, and sustainability. Consequently, integrated design in civil engineering has become more popular, useful, and important. Material-oriented integrated design and construction of structures (MIDCS) combine materials engineering and structural engineering in the design stage: it fully utilizes the strengths of materials by selecting the most suitable structural forms and construction methodologies. This paper will explore real-world examples of MIDCS, including the realization of MIDCS in timber seismic-resistant structures, masonry arch structures, long-span steel bridges, prefabricated/on-site extruded light-weight steel structures, fiber-reinforced cementitious composites structures, and fiber-reinforced polymer bridge decks. Additionally, advanced material design methods such as bioinspired design and structure construction technology of additive manufacturing are briefly reviewed and discussed to demonstrate how MIDCS can combine materials and structures. A unified strength-durability design theory is also introduced, which is a human-centric, interdisciplinary, and holistic approach to the description and development of any civil infrastructure and includes all processes directly involved in the life cycle of the infrastructure. Finally, this paper lays out future research directions for further development in the field.

关键词: integrated design and construction     fiber-reinforced concrete     fiber-reinforced polymer     light-weight steel structures     digital fabrication     composites    

Mesoscale fabrication of a complex surface for integral impeller blades

Xibin WANG,Tianfeng ZHOU,Lijing XIE,Li JIAO,Zhibing LIU,Zhiqiang LIANG,Pei YAN

《机械工程前沿(英文)》 2017年 第12卷 第1期   页码 116-131 doi: 10.1007/s11465-017-0426-1

摘要:

Integral impeller is the most important component of a mini-engine. However, the machining of a mesoscale impeller with a complex integral surface is difficult because of its compact size and high accuracy requirement. A mesoscale component is usually manufactured by milling. However, a conventional milling tool cannot meet the machining requirements because of its size and stiffness. For the fabrication of a complex integral impeller, a micro-ball-end mill is designed in accordance with the non-instantaneous-pole envelope principle and manufactured by grinding based on the profile model of the helical groove and the mathematical model of the cutting edge curve. Subsequently, fractal theory is applied to characterize the surface quality of the integral impeller. The fractal theory-based characterization shows that the completed mesoscale integral impeller exhibits a favorable performance in terms of mechanical properties and morphological accuracy.

关键词: mesoscale fabrication     micro-milling tool     mesoscale milling     impeller blade    

A multi-probe micro-fabrication apparatus based on the friction-induced fabrication method

Zhijiang WU, Chenfei SONG, Jian GUO, Bingjun YU, Linmao QIAN

《机械工程前沿(英文)》 2013年 第8卷 第4期   页码 333-339 doi: 10.1007/s11465-013-0276-4

摘要:

A novel multi-probe micro-fabrication apparatus was developed based on the friction-induced fabrication method. The main parts of the apparatus include actuating device, loading system, and control system. With a motorized linear stage, the maximum fabrication area of 50 mm × 50 mm can be achieved, and the maximum sliding speed of probes can be as high as 10 mm/s. Through locating steel micro balls into indents array, the preparation of multi-probe array can be realized by a simple and low-cost way. The cantilever was designed as a structure of deformable parallelogram with two beams, by which the fabrication force can be precisely controlled. Combining the friction-induced scanning with selective etching in KOH solution, various micro-patterns were fabricated on Si(100) surface without any masks or exposure. As a low-cost and high efficiency fabrication device, the multi-probe micro-fabrication apparatus may encourage the development of friction-induced fabrication method and shed new light on the texture engineering.

关键词: friction-induced fabrication     silicon     surface texture     friction     multi-probe    

Platform governance in the era of AI and the digital economy

《工程管理前沿(英文)》 2023年 第10卷 第1期   页码 177-182 doi: 10.1007/s42524-022-0241-1

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Precision glass molding: Toward an optimal fabrication of optical lenses

Liangchi ZHANG,Weidong LIU

《机械工程前沿(英文)》 2017年 第12卷 第1期   页码 3-17 doi: 10.1007/s11465-017-0408-3

摘要:

It is costly and time consuming to use machining processes, such as grinding, polishing and lapping, to produce optical glass lenses with complex features. Precision glass molding (PGM) has thus been developed to realize an efficient manufacture of such optical components in a single step. However, PGM faces various technical challenges. For example, a PGM process must be carried out within the super-cooled region of optical glass above its glass transition temperature, in which the material has an unstable non-equilibrium structure. Within a narrow window of allowable temperature variation, the glass viscosity can change from 105 to 1012 Pa·s due to the kinetic fragility of the super-cooled liquid. This makes a PGM process sensitive to its molding temperature. In addition, because of the structural relaxation in this temperature window, the atomic structure that governs the material properties is strongly dependent on time and thermal history. Such complexity often leads to residual stresses and shape distortion in a lens molded, causing unexpected changes in density and refractive index. This review will discuss some of the central issues in PGM processes and provide a method based on a manufacturing chain consideration from mold material selection, property and deformation characterization of optical glass to process optimization. The realization of such optimization is a necessary step for the Industry 4.0 of PGM.

关键词: precision glass molding     optical lens     constitutive modeling     optimization     manufacturing chain     Industry 4.0    

Revisiting digital twins: Origins, fundamentals, and practices

《工程管理前沿(英文)》   页码 668-676 doi: 10.1007/s42524-022-0216-2

摘要: The digital twins (DT) has quickly become a hot topic since it was proposed. It appears in all kinds of commercial propaganda and is widely quoted by academic circles. However, the term DT has misstatements and is misused in business and academics. This study revisits DT and defines it to be a more advanced system/product/service modeling and simulation environment that combines most modern information communication technologies (ICTs) and engineering mechanism digitization and characterized by system/product/service life cycle management, physically geometric visualization, real-time sensing and measurement of system operating conditions, predictability of system performance/safety/lifespan, and complete engineering mechanisms-based simulations. The idea of DT originates from modeling and simulation practices of engineering informatization, including virtual manufacturing (VM), model predictive control, and building information modeling (BIM). On the basis of the two-element VM model, we propose a three-element model to represent DT. DT does not have its unique technical characteristics. The existing practices of DT are extensions of the engineering informatization embracing modern ICTs. These insights clarify the origin of DT and its technical essentials.

关键词: virtual manufacturing     digital twins     modeling and simulation     digitization     computational engineering    

Development trend of urban design in “digital age”: Pan-dimensionality and individual-ubiquity

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 569-575 doi: 10.1007/s11709-021-0735-7

摘要: The wave of “digital age” featuring digital information is coming. Digital technology is profoundly changing the societal development direction and evolution paths. It also has significant bearing on production modes, social interactions and lifestyles. With regard to urban design, a system of knowledge about the creation and adaptation of material space forms that integrate humanities, art, technology and materials, digital technology has provided it with a brand-new and revolutionary scientific impetus for its evolution. The result of this evolution is “digital urban design paradigm based on human-computer interaction”, i.e., the urban development is moving toward “pan-dimensionality” and “individual ubiquity”. The future of urban design will construct a new approach to urban research and engineering, which is more complex, capable of accommodating and compatible with multiple goals of “instrumental rationality” and “value rationality”. Such a new approach shall be led by the probabilistic theory of “gray scale thinking”, reflecting quaternary synergetic view of “scientific rationality, ecological rationality, cultural rationality and technical rationality” to realize the cognitive progress of “engineering for the benefit of mankind”.

关键词: digital age     urban design     multiple objectives     human-computer interaction     pan-dimensionality     individual-ubiquity    

Solid-state-reaction fabrication and properties of a high-doping Nd:YAG transparent laser ceramic

WU Yusong, LI Jiang, PAN Yubai, LIU Wenbin, AN Liqiong, WANG Shiwei, GUO Jingkun

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 248-252 doi: 10.1007/s11705-008-0048-6

摘要: High-quality neodymium-doped yttrium aluminum garnet (Nd:YAG) transparent ceramic (4.0 mole percent) was fabricated by a solid-state reaction method and vacuum sintering. The microstructure, optical transmittance, spectral properties and laser performance were investigated. The average grain size of the sample is about 10 ?m. The transmittance of a 2.8-mm thick sample reaches 79.5% at the laser wavelength of 1064 nm. The highest absorption peak is centered at 807 nm and the absorption coefficient is 13.9 cm. The absorption coefficient at the laser wavelength is 0.2 cm. The main emission peak is at 1064 nm and the fluorescence lifetime is 102 ?s. A laser diode (808 nm) whose maximum output is about 1000 mW was used as a pump source and an end-pumped laser experiment was performed. The 1064 nm-CW-laser output was obtained and the threshold is 733 mW. With 998 mW of maximum absorbed pump power, a laser output of 17 mW is obtained with a slope efficiency of 6.1%.

关键词: neodymium-doped yttrium     maximum absorbed     microstructure     fluorescence lifetime     threshold    

Micro-optical fabrication by ultraprecision diamond machining and precision molding

Hui LI, Likai LI, Neil J. NAPLES, Jeffrey W. ROBLEE, Allen Y. YI

《机械工程前沿(英文)》 2017年 第12卷 第2期   页码 181-192 doi: 10.1007/s11465-017-0444-z

摘要:

Ultraprecision diamond machining and high volume molding for affordable high precision high performance optical elements are becoming a viable process in optical industry for low cost high quality microoptical component manufacturing. In this process, first high precision microoptical molds are fabricated using ultraprecision single point diamond machining followed by high volume production methods such as compression or injection molding. In the last two decades, there have been steady improvements in ultraprecision machine design and performance, particularly with the introduction of both slow tool and fast tool servo. Today optical molds, including freeform surfaces and microlens arrays, are routinely diamond machined to final finish without post machining polishing. For consumers, compression molding or injection molding provide efficient and high quality optics at extremely low cost. In this paper, first ultraprecision machine design and machining processes such as slow tool and fast too servo are described then both compression molding and injection molding of polymer optics are discussed. To implement precision optical manufacturing by molding, numerical modeling can be included in the future as a critical part of the manufacturing process to ensure high product quality.

关键词: ultraprecision machining     slow tool servo     fast tool servo     compression molding     injection molding     microlens arrays     optical fabrication    

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    

Spontaneous polarization enhanced bismuth ferrate photoelectrode: fabrication and boosted photoelectrochemical

《能源前沿(英文)》 2021年 第15卷 第3期   页码 781-790 doi: 10.1007/s11708-021-0782-8

摘要: In this paper, the fabrication of a highly orientated Bi2Fe4O9 (BFO) photoelectrode in the presence of two-dimensional (2D) graphene oxide (GO) was reported. It was found that the GO can be used as a template for controlling the growth of BFO, and the nanoplate composites of BFO/reduced graphene oxide (RGO) with a high orientation can be fabricated. The thickness of the nanoplates became thinner as the ratio of GO increased. As a result, the ferroelectric spontaneous polarization unit arranges itself in the space in a periodic manner, leading to the formation of a polarization field along a special direction. Therefore, the created built-in electric field of the nanoplate composites of BFO/RGO is improved upon the increase of the amount of RGO. As expected, carrier separation is enhanced by the built-in electric field, therefore substantially enhancing the photoelectrochemical (PEC) activity of water splitting compared to pure BFO under the irradiation of visible-light.

关键词: bismuth ferrate     ferroelectric polarisation     photoelectrochemical (PEC) water splitting     graphene oxide (GO)     high orientation    

Embracing digital mindsets to ensure a sustainable future

《环境科学与工程前沿(英文)》 2023年 第18卷 第3期 doi: 10.1007/s11783-024-1799-0

关键词: Wildlife     Climate Change     Heavy metals     Noise     LAN     Light pollution    

Structure controlling and process scale-up in the fabrication of nanomaterials

Chunzhong LI,

《化学科学与工程前沿(英文)》 2010年 第4卷 第1期   页码 18-25 doi: 10.1007/s11705-009-0305-3

摘要: Nanotechnology is already having a significant commercial impact, and will very certainly have a much greater impact in the future. The research on process engineering and scale-up will be very important for the commercial production and application of nanomaterials, because the properties and structure of nanomaterials are not only determined by the nucleation and growth process, but also strongly affected by the engineering properties, such as the mixing, the heat and mass transfer, and also the distribution of temperature, concentration, etc. This paper will present some research work in our laboratory on the fabrication of nanomaterials. Based on the chemical engineering principle and methods, many kinds of novel nanomaterials can be synthesized and their structure can be easily controlled through adjusting the parameters of the fluid mixing, and the distribution of temperature, residence time and concentration, etc. By using the micro-mixing, heat and mass transfer and reaction control methods, the host-guest nanocomposites have been assembled and assumed as the novel electroanalytical sensing nanobiocomposite materials. Based on the principles of chemical engineering, the manufacturing technologies for magnetic powders, calcium carbonate, and titanium dioxide have been developed for commercial-scale production, and the largest production scale has reached 15 kt/year.

关键词: scale-up     significant commercial     electroanalytical     engineering     laboratory    

Fabrication of titanosilicate pillared MFI zeolites with tailored catalytic activity

Baoyu Liu, Qiaowen Mu, Jiajin Huang, Wei Tan, Jing Xiao

《化学科学与工程前沿(英文)》 2020年 第14卷 第5期   页码 772-782 doi: 10.1007/s11705-019-1859-3

摘要: Titanosilicate pillared MFI zeolite nanosheets were successfully synthesized by infiltrating the mixed tetraethyl orthosilicate (TEOS)/tetrabutyl orthotitanate (TBOT) solvent into the gallery space between adjacent MFI zeolite layers. The obtained zeolite catalysts were characterized using powder X-ray diffraction, N adsorption/desorption isotherms, scanning electron microscopy, transmission electron microscopy, ultraviolet–visible spectroscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy techniques. The H O oxidation of dibenzothiophene (DBT) was used to evaluate the catalytic performance of the obtained titanosilicate pillared MFI zeolites. The conversion of DBT and selectivity of dibenzothiophene sulfone (DBTS) were most affected by the textural properties of the zeolites. This was attributed to the DBT and DBTS molecules being larger than micropores of the MFI zeolites. The conversion of DBT and yield of DBTS could be systematically tailored by tuning the molar ratio of the TEOS/TBOT solvent. These results implied that a balance between the meso- and microporosity of zeolites and tetrahedrally coordinated Ti(IV) active sites of titanosilicate pillars can be achieved for the preparation of desired catalysts during the oxidation of bulk S compounds.

关键词: MFI zeolite     catalysis     nanosheets     fabrication    

Facile strategy for carbon foam fabrication with lignin as sole feedstock and its applications

《化学科学与工程前沿(英文)》 2023年 第17卷 第8期   页码 1051-1064 doi: 10.1007/s11705-022-2248-x

摘要: This research is a follow-up to our recent discovery of a facile strategy for directly converting lignin powder into carbon foam. In this work, we report that the thermal pretreatment parameters in air can remarkably influence the formation and properties of the derived carbon foam. Thermal pretreatment parameters (heating rate, temperature, and residence time) were systematically investigated and a conversion mechanism into carbon foam was proposed. During the thermal pretreatment, relatively low temperatures, low heating rates, and short residence time hindered the formation of smooth and well-connected structures in the carbon foam. The overall product yields were similar regardless of the thermal pretreatment conditions. The densities of the different carbon foams ranged 0.27–0.83 g∙cm−3. The carbon foams with the highest compressive strengths (> 10 MPa) were KLPC280-2-5, KLPC300-0-5, and KLPC300-2-2.5. KLPC280-2-5 exhibited a high iodine sorption value (182 mg∙g−1). KLPC300-2-5 exhibited a specific capacitance of 158 F∙g−1 at a current density of 0.05 A∙g−1. The maximum evaporation rates in the solar vapor generation experiments were 1.05 and 1.38 kg∙m−2∙h−1 under 100 and 150 mW∙cm−2 irradiation, respectively. The good performances are attributed to the robust, porous, and continuous structure.

关键词: lignin     carbon foam     thermal pretreatment     solar vapor generation    

标题 作者 时间 类型 操作

Materials-oriented integrated design and construction of structures in civil engineering—A review

期刊论文

Mesoscale fabrication of a complex surface for integral impeller blades

Xibin WANG,Tianfeng ZHOU,Lijing XIE,Li JIAO,Zhibing LIU,Zhiqiang LIANG,Pei YAN

期刊论文

A multi-probe micro-fabrication apparatus based on the friction-induced fabrication method

Zhijiang WU, Chenfei SONG, Jian GUO, Bingjun YU, Linmao QIAN

期刊论文

Platform governance in the era of AI and the digital economy

期刊论文

Precision glass molding: Toward an optimal fabrication of optical lenses

Liangchi ZHANG,Weidong LIU

期刊论文

Revisiting digital twins: Origins, fundamentals, and practices

期刊论文

Development trend of urban design in “digital age”: Pan-dimensionality and individual-ubiquity

期刊论文

Solid-state-reaction fabrication and properties of a high-doping Nd:YAG transparent laser ceramic

WU Yusong, LI Jiang, PAN Yubai, LIU Wenbin, AN Liqiong, WANG Shiwei, GUO Jingkun

期刊论文

Micro-optical fabrication by ultraprecision diamond machining and precision molding

Hui LI, Likai LI, Neil J. NAPLES, Jeffrey W. ROBLEE, Allen Y. YI

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

Spontaneous polarization enhanced bismuth ferrate photoelectrode: fabrication and boosted photoelectrochemical

期刊论文

Embracing digital mindsets to ensure a sustainable future

期刊论文

Structure controlling and process scale-up in the fabrication of nanomaterials

Chunzhong LI,

期刊论文

Fabrication of titanosilicate pillared MFI zeolites with tailored catalytic activity

Baoyu Liu, Qiaowen Mu, Jiajin Huang, Wei Tan, Jing Xiao

期刊论文

Facile strategy for carbon foam fabrication with lignin as sole feedstock and its applications

期刊论文