检索结果-南通市图书馆

Exploration on the stability conditions in bubble columns by noncooperative game theory

Chinese Journal of Chemical Engineering 2022年第10期50卷 75-84页

作者： jiachen liu Xiaoping Guan Ning Yang State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

The energy-minimization multiscale(EMMS)model,originally proposed for gas-solid fluidization,features a stability condition to close the simplified conservation *** was put forward to physically reflect the compromise of two dominant mechanisms,i.e.,the particle-dominated with minimal potential energy of particles,and the gas-dominated with the least resistance for gas to penetrate through the particle *** stability condition was then formulated as the minimization of the ratio of these two physical ***,the EMMS approach was later extended to the gas-liquid flow in bubble columns,termed dual-bubble-size *** considers the compromise of two dominant mechanisms,i.e.,the liquid-dominated regime with small bubbles,and the gas-dominated regime with large *** stability condition was then formulated as the minimization of the sum of these two physical ***,the two stability conditions were expressed in different manner,though gas-solid and gas-liquid systems bear some *** addition,both the conditions transform the original multiobjective variational problem into a single-objective *** mathematical formulation of stability condition remains therefore an open *** study utilizes noncooperative game theory and noninferior solutions to directly solve the multi-objective variational problem,aiming to explo re the different pathways of compromise of dominant *** results show that only keeping the single dominant mechanism cannot capture the jump change of gas holdup,which is associated with flow regime *** of dominant mechanisms,noninferior solutions and noncooperative game theory can predict the flow regime ***,the game between the two mechanisms makes the two-bubble structure degenerate and reduce to the single-bubble *** game of the three mechanisms restores the two-bubble *** exploration on the formulation of stability conditions may

关键词： Bubble column Flow regimes Mesoscale Noncooperative gametheory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cell sedimentation during 3D bioprinting:amini review

引用

Bio-Design and Manufacturing 2022年第3期5卷 617-626页

作者： Heqi Xu jiachen liu Zhengyi Zhang Changxue Xu Department of Industrial Manufacturingand Systems EngineeringTexas Tech UniversityLubbockTX 79409USA School of Naval Architecture and Ocean Engineering Huazhong University of Science and TechnologyWuhan 430074China

Introduction In the past decade,three-dimensional(3D)bioprinting,which precisely deposits bioink composed of the biological materials and the living cells into delicate structures with the living cells encapsulated,has made numerous important advances in tissue engineering and regenerative medicine[1,2].Depending on the printing mechanism,3D bioprinting technologies are generally categorized into four types:inkjet-based bioprinting,microextrusion-based bioprinting,laser-assisted bioprinting,and stereolithography-based bioprinting[3].

关键词： printing sedimentation precisely

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Status of Rare Earths for Agriculture in China

引用

Journal of Rare Earths 2004年第z1期22卷 313-316页

作者： Wang jiachen Yang Jun liu Xiangsheng Beijing General Research Instiutes for Nonferrous Metals Beijing 100088 China National Rare Earth Center for Agriculture of China Beijing 100088 China Grirem Advanced Materials Co.Ltd. Beijing100088 China

Rare Earths (RE) for agriculture is a very typical application and has already brought good economic benefit to Chinese agriculture and *** this paper, the origin, development, status and the future of RE for agriculture in China were ***, through the researches of RE in the fields of physiological activity, physiological and biochemical mechanism, sanitation toxicology and environment security in 1980's, RE has been extended more widely in agriculture, such as crops, vegetables, forest, wood grass and stock breeding, such as cattle, fish and ***, with using of new techniques that were developed in the "State Ninth Five-Year Plan", the utilization area of RE was expanded to broad agricultural space, such as sunlight converting plastic film, RE fertilizer, RE drought resistant and RE water saving materials and new RE top dressing ***, with the development of the nanometer materials, the techniques and process of nanometer RE materials were *** these kinds of materials, the new seed cover matters, new seed mixed matter and new nanometer fertilizer will appear in the near future, and will produce many updated techniques and improve a new round RE application in agriculture.

关键词： agriculture typical application origin development status

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Composite thermal protection coating on woven silica fiber fabrics

引用

Science China(Technological Sciences) 2014年第6期57卷 1121-1126页

作者： liu MengXia XUE Tao ZHAO YingNa liu Shan liu jiachen Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin University Analysis and Measurement Center Tianjin University Hebei Provincial Key Laboratory of Inorganic Nonmetallic Materials College of Materials Science and Engineering Hebei United University

A composite coating with inner and outer layers was prepared for the thermal protection of woven silica fiber *** a sol mixture of a silica sol and AlF3/SiO2 particles mixed in the stoichiometric molar ratio for mullite,hollow silica spheres and short mullite fibers were added to the inner layer and outer layer,*** phase composition and thermal evolution of the coating,along with the interfacial microstructure between the coating and the matrix,were characterized by means of X-ray diffraction,differential scanning calorimetry/thermogravimetry,scanning electron microscopy,and tensile strength *** whiskers grew between 950°C and 1200°C and helped prevent thermal cracking during the drying and densification *** hollow silica spheres might play dual roles,weakening the adhesion between the coating and the fibers by reducing their direct contact,but strengthening the joining between the coating and substrate by embedding themselves among the fabrics.

关键词： silica fiber fabrics AlF3/SiO2 composite coating mullite whiskers

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

General trends in surface stability and oxygen adsorption behavior of transition metal diborides(TMB_2)

引用

Journal of Materials Science & Technology 2019年第4期35卷 584-590页

作者： Wei Sun Fuzhi Dai Huimin Xiang jiachen liu Yanchun Zhou Aerospace Research Institute of Materials & Processing Technology School of Materials Science and Engineering Tianjin University

The potential applications of transition metal diborides(TMB_2) in extreme environments are particularly attractive but still blocked by some intrinsic properties such as poor resistances to thermal shock and oxidation. Since surface plays a key role during grain growth and oxygen adsorption, an insight into the surface properties of TMB_2 is essential for understanding the materials performance and accelerating the development of ultra-high temperature ceramics. By employing two-region modeling method, the stability and oxygen adsorption behavior of TMB_2 surfaces were investigated by first-principles calculations based on density functional theory. The effects of valance electron concentration on the surface stability and oxygen adsorption were studied and the general trends were summarized. After analyzing the anisotropy in surface stability and oxygen adsorption, the observed grain morphology of TMB_2 were well explained, and it was also predicted that YB_2, HfB_2 and TaB_2 may have better initial oxidation resistance than ZrB_2.

关键词： Transition metal diborides First-principles calculation Surface energy Grain morphology Oxidation resistance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High strength and high porosity YB2C2 ceramics prepared by a new high temperature reaction/partial sintering process

引用

Journal of Materials Science & Technology 2019年第12期35卷 2883-2891页

作者： Heng Chen Huimin Xiang Fuzhi Dai jiachen liu Yanchun Zhou Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing100076China

Porous ultrahigh temperature ceramics(UHTCs) are potential candidates as reusable thermal protection materials of transpiration cooling system in scramjet engine. However, low strength and low porosity are the main limitations of porous UHTCs. To overcome these problems, herein, a new and simple in-situ reaction/partial sintering process has been developed for preparing high strength and high porosity porous YB2C2. In this process, a simple gas-releasing in-situ reaction has been designed, and the formation and escape of gases can block the shrinkage during sintering process, which is favorable to increase the porosity of porous YB2C2. In order to demonstrate the advantages of the new method, porous YB2C2 ceramics have been fabricated from Y2O3, BN and graphite powders for the first time. The as-prepared porous YB2C2 ceramics possess high porosity of 57.17%–75.26% and high compressive strength of 9.32–34.78 *** porosity, sintered density, radical shrinkage and compressive strength of porous YB2C2 ceramics can be controlled simply by changing the green density. Due to utilization of graphite as the carbon source, the porous YB2C2 ceramics show anisotropy in microstructure and mechanical behavior. These features render the porous YB2C2 ceramics promising as a thermal-insulating light-weight component for transpiration cooling system.

关键词： Ultrahigh temperature ceramics(UHTCs) YB2C2 Porous ceramics Microstructure Strength

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Lateral abutment pressure distribution and evolution in wide pillars under the first mining effect

引用

International Journal of Mining Science and Technology 2023年第3期33卷 309-322页

作者： Zhen Zhang Zhen Li Gang Xu Xiaojin Gao Qianjin liu Zhengjie Li jiachen liu Coal Mining and Designing Branch China Coal Research InstituteBeijing 100013China CCTEG Coal Mining Research Institute Beijing 100013China Coal Mining&Designing Department Tiandi Science&Technology Co.Ltd.Beijing 100013China School of Civil Engineering Henan Polytechnic UniversityJiaozuo 454003China Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization Jiaozuo 454003China

The wide pillars are generally popular due to the high productivity and efficiency in Northwest *** distribution of lateral abutment pressure in coal pillars is important for mining *** reveal the effect of the first mining on the lateral abutment pressure distribution and evolution in wide pillars,an in-situ experiment,theoretical analysis and numerical simulation were ***,the field monitoring of lateral abutment pressure was conducted from the perspective of time and space in the Chahasu Coal Mine,Huangling No.2 Coal Mine and Lingdong Coal Mine during the first *** on the field monitoring stress,a theoretical model was proposed to reveal the lateral abutment pressure *** methodology was demonstrated through a case *** at the distribution mechanism,a numerical experiment was conducted through the finite-discrete element method(FDEM).Last,field observations of borehole fractures were performed to further study the damage *** addition,two types of lateral abutment pressure evolution with mining advance were *** on the stress monitoring layout were proposed as *** results could provide foundations for strata control and disaster prevention in wide pillars in underground coal mines.

关键词： Wide pillar Lateral abutment pressure Pillar stress First mining effect Field monitoring

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Laser wavelength effects on(Ti,Al,Si)N in near-field laser nanostructuring by micron optical fiber enhanced irradiation

引用

Science China(Technological Sciences) 2013年第12期56卷 3012-3016页

作者： liu DaMeng liu jiachen WANG Hui SU Kang SHAO TianMin State Key Laboratory of Tribology Tsinghua University

The effects of laser wavelengths(1064,532,355 and 266 nm)on nano-processing of fabricating a groove structure on(Ti,Al,Si)N alloy film using the micro-fiber near-field enhanced irradiation are *** is observed that variations of laser wavelength can effectively change the widths of the groove structures,which are featured as one-dimension bowl-like *** minimum of the groove width can be achieved at 293 nm with a 532 nm laser *** order to fabricate the groove in nanoscale,enough energy is delivered onto(Ti,Al,Si)N surface by a single laser *** results are also discussed to understand the experimental results.

关键词： micro-fiber field enhancement nano-optics nanostructuring

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Low thermal conductivity and high porosity ZrC and HfC ceramics prepared by in-situ reduction reaction/partial sintering method for ultrahigh temperature applications

引用

Journal of Materials Science & Technology 2019年第12期35卷 2778-2784页

作者： Heng Chen Huimin Xiang Fu-Zhi Dai jiachen liu Yanchun Zhou Key Laboratory ofAdvanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin300072China scence and Technology on Advanced Funcrional Composite Laboratory Aerospace Research lstute of Materials&Poessings TechnologyBejing100076China

Porous ultra-high temperature ceramics(UHTCs) are potential candidates as high-temperature thermal insulation materials. However, high thermal conductivity is the main obstacle to the application of porous UHTCs. In order to address this problem, herein, a new method combining in-situ reaction and partial sintering has been developed for preparing porous Zr C and Hf C with low conductivity. In this process, porous Zr C and Hf C are directly obtained from ZrO2/C and HfO2/C green bodies without adding any pore-forming agents. The release of reaction gas can not only increase the porosity but also block the shrinkage. The asprepared porous Zr C and Hf C exhibit homogeneous porous microstructure with grain sizes in the range of 300–600 nm and 200–500 nm, high porosity of 68.74% and 77.82%, low room temperature thermal conductivity of 1.12 and 1.01 W·m-1 K-1, and compressive strength of 8.28 and 5.51 MPa, *** features render porous Zr C and Hf C promising as light-weight thermal insulation materials for ultrahigh temperature applications. Furthermore, the feasibility of this method has been demonstrated and porous Nb C, Ta C as well as Ti C have been prepared by this method.

关键词： Ultrahigh temperature ceramics(UHTCs) Transition metal carbides Porous ceramics ZrC and HfC Thermal conductivity Mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mechanical Properties and Damage Tolerance of Bulk Yb_3Al_5O_(12) Ceramic

引用

Journal of Materials Science & Technology 2015年第4期31卷 369-374页

作者： Xiaofei Wang Huimin Xiang Xin Sun jiachen liu Feng Hou Yanchun Zhou Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing Technology Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin University

Yb3Al5O12has potential applications as thermal barrier coatings（TBCs） because it shows low thermal conductivity and close thermal expansion coefficient to nickel-based *** a prospective TBC material,besides superior thermal properties,the mechanical properties are also *** this paper,we present the mechanical properties of Yb3Al5O12including elastic moduli,hardness,strength,and fracture *** Young’s modulus of Yb3Al5O12is 282 *** shear-modulus-to-bulkmodulus ratio of Yb3Al5O12is 0.63,which indicates relatively low shear deformation *** addition,Yb3Al5O12exhibits high strength and fracture toughness but low hardness compared to yttria stabilized zirconia（YSZ）,the most successful TBC *** observation reveals that the fracture surface of Yb3Al5O12displays 'layered structure feature',which is caused by crack *** based on Hertzian contact test demonstrates that Yb3Al5O12is a damage-tolerant *** deflection and bridging can arouse shear faults,dissipate the local damage energy,and restrict the crack propagation within the material,which play an important role in enhancing the damage *** superior mechanical properties and good damage tolerance ensure Yb3Al5O12a promising candidate for TBC applications.

关键词： Yb3Al5O12 Mechanical properties Damage Strength

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：