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Unified method for typical gear failure modeling and stiffness calculation based on the matrix equation

《机械工程前沿（英文）》 2024年 第19卷 第3期 doi: 10.1007/s11465-024-0794-2

摘要： The failure types in gear systems vary, with typical ones mainly including pitting, cracking, wear, and broken teeth. Different modeling and stiffness calculation methods have been developed for various gear failure types. A unified method for typical gear failure modeling and stiffness calculation is introduced in this study by considering the deviations in the time-varying meshing stiffness (TVMS) of faulty gears resulting from the use of different methods. Specifically, a gear tooth is discretized into a large number of microelements expressed with a matrix, and unified models of typical gear failures are built by adjusting the values of the matrix microelements. The values and positions of the microelements in the tooth failure model matrix have the same physical meaning as the parameter variables in the potential energy method (PEM), so the matrix-based failure model can be perfectly matched with PEM. Afterward, a unified method for TVMS is established. Modeling of healthy and faulty gears with pitting, wear, crack, and broken tooth is performed with the matrix equation, and the corresponding TVMS values are calculated by incorporating the matrix models with PEM. On the basis of the results, the mechanism of typical fault types that affect TVMS is analyzed, and the conclusions are verified through the finite element method. The developed unified method is a promising technique for studying the dynamic response characteristics of gear systems with different failure types because of its superiority in eliminating stiffness deviations.

关键词： gears     matrix equation     failure modeling     TVMS calculation     unified method    

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An artificial neural network based deep collocation method for the solution of transient linear and nonlinear partial differential equations

《结构与土木工程前沿（英文）》 2024年 第18卷 第8期   页码 1296-1310 doi: 10.1007/s11709-024-1011-4

摘要： A combined deep machine learning (DML) and collocation based approach to solve the partial differential equations using artificial neural networks is proposed. The developed method is applied to solve problems governed by the Sine–Gordon equation (SGE), the scalar wave equation and elasto-dynamics. Two methods are studied: one is a space-time formulation and the other is a semi-discrete method based on an implicit Runge–Kutta (RK) time integration. The methodology is implemented using the Tensorflow framework and it is tested on several numerical examples. Based on the results, the relative normalized error was observed to be less than 5% in all cases.

关键词： collocation method     artificial neural networks     deep machine learning     Sine–Gordon equation     transient wave equation     dynamic scalar and elasto-dynamic equation     Runge–Kutta method    

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Decellularized extracellular matrix mediates tissue construction and regeneration

《医学前沿（英文）》 2022年 第16卷 第1期   页码 56-82 doi: 10.1007/s11684-021-0900-3

摘要： Contributing to organ formation and tissue regeneration, extracellular matrix (ECM) constituents provide tissue with three-dimensional (3D) structural integrity and cellular-function regulation. Containing the crucial traits of the cellular microenvironment, ECM substitutes mediate cell–matrix interactions to prompt stem-cell proliferation and differentiation for 3D organoid construction in vitro or tissue regeneration in vivo. However, these ECMs are often applied generically and have yet to be extensively developed for specific cell types in 3D cultures. Cultured cells also produce rich ECM, particularly stromal cells. Cellular ECM improves 3D culture development in vitro and tissue remodeling during wound healing after implantation into the host as well. Gaining better insight into ECM derived from either tissue or cells that regulate 3D tissue reconstruction or organ regeneration helps us to select, produce, and implant the most suitable ECM and thus promote 3D organoid culture and tissue remodeling for in vivo regeneration. Overall, the decellularization methodologies and tissue/cell-derived ECM as scaffolds or cellular-growth supplements used in cell propagation and differentiation for 3D tissue culture in vitro are discussed. Moreover, current preclinical applications by which ECM components modulate the wound-healing process are reviewed.

关键词： decellularized extracellular matrix     3D culture     organoids     tissue repair    

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Perspective of mixed matrix membranes for carbon capture

Shinji Kanehashi, Colin A. Scholes

《化学科学与工程前沿（英文）》 2020年 第14卷 第3期   页码 460-469 doi: 10.1007/s11705-019-1881-5

摘要： Polymeric membrane-based gas separation has found wide applications in industry, such as carbon capture, hydrogen recovery, natural gas sweetening, as well as oxygen enrichment. Commercial gas separation membranes are required to have high gas permeability and selectivity, while being cost-effective to process. Mixed matrix membranes (MMMs) have a composite structure that consists of polymers and fillers, therefore featuring the advantages of both materials. Much effort has been made to improve the gas separation performance of MMMs as well as general membrane properties, such as mechanical strength and thermal stability. This perspective describes potential use of MMMs for carbon capture applications, explores their limitations in fabrication and methods to overcome them, and addresses their performance under industry gas conditions.

关键词： membranes     polymeric     mixed matrix     impurities    

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Comparison of the performance of traditional advection-dispersion equation and mobile-immobile model

Haizhu HU,Xiaomin MAO

《农业科学与工程前沿（英文）》 2016年 第3卷 第3期   页码 241-248 doi: 10.15302/J-FASE-2016108

摘要： The traditional advection-dispersion equation (ADE) and the mobile-immobile model (MIM) are widely used to describe solute transport in heterogeneous porous media. However, the fitness of the two models is case-dependent. In this paper, the transport of conservative, adsorbing and degradable solutes through a 1 m heterogeneous soil column under steady flow condition was simulated by ADE and MIM, and sensitivity analysis was conducted. Results show that MIM tends to prolong the breakthrough process and decrease peak concentration for all three solutes, and tailing and skewness are more pronounced with increasing dispersivity. Breakthrough curves of the adsorbing solute simulated by MIM are less sensitive to the retardation factor compared with the results simulated by ADE. The breakthrough curves of degradable solute obtained by MIM and ADE nearly overlap with a high degradation rate coefficient, indicating that MIM and ADE perform similarly for simulating degradable solute transport when biochemical degradation prevails over the mass exchange between mobile and immobile zones. The results suggest that the physical significance of dispersivity should be carefully considered when MIM is applied to simulate the degradable solute transport and/or ADE is applied to simulate the adsorbing solute transport in highly dispersive soils.

关键词： solute transport     advection dispersion equation (ADE)     mobile-immobile model (MIM)     conservative solute     adsorbing solute     degradable solute     PHREEQC-2    

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Optimal design of extractive dividing-wall column using an efficient equation-oriented approach

Yingjie Ma, Nan Zhang, Jie Li, Cuiwen Cao

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 72-89 doi: 10.1007/s11705-020-1977-y

摘要： The extractive dividing-wall column (EDWC) is one of the most efficient technologies for separation of azeotropic or close boiling-point mixtures, but its design is fairly challenging. In this paper we extend the hybrid feasible path optimisation algorithm (Ma Y, McLaughlan M, Zhang N, Li J. Computers & Chemical Engineering, 2020, 143: 107058) for such optimal design. The tolerances-relaxation integration method is refined to allow for long enough integration time that can ensure the solution of the pseudo-transient continuation simulation close to the steady state before the required tolerance is used. To ensure the gradient and Jacobian information available for optimisation, we allow a relaxed tolerance for the simulation in the sensitivity analysis mode when the simulation diverges under small tolerance. In addition, valid lower bounds on purity of the recycled entrainer and the vapour flow rate in column sections are imposed to improve computational efficiency. The computational results demonstrate that the extended hybrid algorithm can achieve better design of the EDWC compared to those in literature. The energy consumption can be reduced by more than 20% compared with existing literature report. In addition, the optimal design of the heat pump assisted EDWC is achieved using the improved hybrid algorithm for the first time.

关键词： design     extractive dividing-wall column     equation-oriented optimisation     pseudo-transient continuation model     hybrid algorithm    

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Glycosylation of dentin matrix protein 1 is critical for fracture healing via promoting chondrogenesis

Hui Xue, Dike Tao, Yuteng Weng, Qiqi Fan, Shuang Zhou, Ruilin Zhang, Han Zhang, Rui Yue, Xiaogang Wang, Zuolin Wang, Yao Sun

《医学前沿（英文）》 2019年 第13卷 第5期   页码 575-589 doi: 10.1007/s11684-019-0693-9

摘要： Fractures are frequently occurring diseases that endanger human health. Crucial to fracture healing is cartilage formation, which provides a bone-regeneration environment. Cartilage consists of both chondrocytes and extracellular matrix (ECM). The ECM of cartilage includes collagens and various types of proteoglycans (PGs), which play important roles in maintaining primary stability in fracture healing. The PG form of dentin matrix protein 1 (DMP1-PG) is involved in maintaining the health of articular cartilage and bone. Our previous data have shown that DMP1-PG is richly expressed in the cartilaginous calluses of fracture sites. However, the possible significant role of DMP1-PG in chondrogenesis and fracture healing is unknown. To further detect the potential role of DMP1-PG in fracture repair, we established a mouse fracture model by using a glycosylation site mutant DMP1 mouse (S89G-DMP1 mouse). Upon inspection, fewer cartilaginous calluses and down-regulated expression levels of chondrogenesis genes were observed in the fracture sites of S89G-DMP1 mice. Given the deficiency of DMP1-PG, the impaired IL-6/JAK/STAT signaling pathway was observed to affect the chondrogenesis of fracture healing. Overall, these results suggest that DMP1-PG is an indispensable proteoglycan in chondrogenesis during fracture healing.

关键词： fracture     extracellular matrix     dentin matrix protein 1     proteoglycan     cartilage    

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Role of salivary matrix metalloproteinase-8 (MMP-8) in chronic periodontitis diagnosis

null

《医学前沿（英文）》 2015年 第9卷 第1期   页码 72-76 doi: 10.1007/s11684-014-0347-x

摘要：

Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases (MMPs) secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tissue, leading to chronic periodontitis. This study aimed to correlate salivary levels of MMP-8 and periodontal parameters of chronic periodontitis to establish MMP-8 as a noninvasive marker for the early diagnosis of chronic periodontitis. The study involved 40 subjects visiting the periodontic OPD of Dr. Ziauddin Ahmad Dental College and Hospital, located in Aligarh, U.P., India, from 2011 to 2012. The subjects were divided into two groups: group I consisted of 20 periodontally healthy subjects (controls) while group II consisted of 20 patients with chronic periodontitis. Chronic periodontitis was assessed on the basis of several periodontal parameters, including pocket probing depth (PPD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI). Around 3 ml of unstimulated and whole expectorated saliva was collected for MMP-8 estimation by ELISA using Quantikine human total MMP-8 immunoassay kits. Data were analyzed using STATISTICA (Windows version 6) software. Salivary MMP-8 levels of groups I and II were 190.91±143.89 ng/ml and 348.26±202.1 ng/ml, respectively. The MMP-8 levels and periodontal status (PPD, CAL, GI, and PI) of groups I and II showed positive and significant correlations (for PPD, r = 0.63, P<0.001; for CAL, r = 0.54, P<0.001; for GI, r = 0.49, P<0.001; and for PI, r = 0.63, P<0.001). The results of this study demonstrate elevated concentrations of MMP-8 in individuals with chronic periodontitis.

关键词： matrix metalloproteinase-8     chronic periodontitis     pocket probing depth     clinical attachment level     gingival index     plaque index    

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Strengthening of reinforced concrete beams using fiber-reinforced cementitious matrix systems fabricated

《结构与土木工程前沿（英文）》 2023年 第17卷 第7期   页码 1100-1116 doi: 10.1007/s11709-023-0967-9

摘要： The performance of a new fiber-reinforced cementitious matrix (FRCM) system developed using custom-designed mortar and fabrics is investigated in this study. The behavior of this system is evaluated in terms of both the flexural and shear strengthening of reinforced concrete beams. Eight beams are designed to assess the effectiveness of the FRCM system in terms of flexural strengthening, and four specimens are designed to investigate their shear behavior. The parameters investigated for flexural strengthening are the number of layers, span/depth ratio, and the strengthening method. Unlike previous studies, custom fabrics with similar axial stiffness are used in all strengthening methods in this study. In the shear-strengthened specimens, the effects of the span/depth ratio and strengthening system type (fiber-reinforced polymer (FRP) or FRCM) are investigated. The proposed FRCM system exhibits desirable flexural and shear strengthening for enhancing the load capacity, provides sufficient bonding with the substrate, and prevents premature failure modes. Considering the similar axial stiffness of fabrics used in both FRCM and FRP systems and the higher load capacity of specimens strengthened by the former, cement-based mortar performs better than epoxy.

关键词： fiber-reinforced cementitious matrix     flexural strengthening     shear strengthening     carbon fiber-reinforced polymer     shear span    

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A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method

Wu REN, Yunxin WU, Zhaowei ZHANG

《机械工程前沿（英文）》 2013年 第8卷 第4期   页码 360-366 doi: 10.1007/s11465-013-0280-8

摘要：

Mobile concrete pump boom is typical multi-body large-scale motion manipulator. Due to posture constantly change in working process, kinematic rule and dynamic characteristic are difficult to solve. A dynamics model of a mobile concrete pump boom is established based on discrete time transfer matrix method (DTTMM). The boom system is divided into sub-structure A and sub-structure B. Sub-structure A is composed by the 1st boom and hydraulic actuator as well as the support. And sub-structure B is consists of the other three booms and corresponding hydraulic actuators. In the model, the booms and links are regarded as rigid elements and the hydraulic cylinders are equivalent to spring-damper. The booms are driven by the controllable hydraulic actuators. The overall dynamic equation and transfer matrix of the model can be assembled by sub-structures A and B. To get a precise result, step size and integration parameters are studied then. Next the tip displacement is calculated and compared with the result of ADAMS software. The displacement and rotation angle curves of the proposed method fit well with the ADAMS model. Besides it is convenient in modeling and saves time. So it is suitable for mobile concrete pump boom real-time monitoring and dynamic analysis. All of these provide reference to boom optimize and engineering application of such mechanisms.

关键词： multi-body     mobile concrete pump boom     discrete time transfer matrix method (DTTMM)     kinematic     dynamic     tip displacement    

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深水钻井隔水导管挠曲方程和固有频率的计算及其研究

姜伟

《中国工程科学》 2011年 第13卷 第5期   页码 66-73

摘要：

从深水钻井应用的隔水导管的使用实际情况出发，应用弹塑性力学中的位移复分原理的Ritz法，考虑了隔水导管所受到的轴向张力T和隔水导管受力产生的倾角α以及由于自重q所产生的自重横向分力qsin α和轴向分力qcos α，建立了较为合理的挠曲方程，并且由此得到隔水导管的固有振动频率的简易计算求解方法。由于该挠曲方程结合了钻具的实际情况，其挠曲方程的约束条件采用的是一端铰支、一端自由的形式，因此其研究更接近实际情况，研究旨在为深水钻井隔水导管的合理使用设计和选择，提供一种更快捷实用的方法，对深水钻井作业有一定的指导意义。

关键词： 深水钻井     隔水导管     挠曲方程     固有频率     形状函数    

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Parametric analysis and design equation of ultimate capacity for unstiffened overlapped CHS K-joints

CHEN Yu, ZHAO Xianzhong, CHEN Yiyi

《结构与土木工程前沿（英文）》 2008年 第2卷 第2期   页码 107-115 doi: 10.1007/s11709-008-0014-x

摘要： A finite element model simulating an experiment on unstiffened, overlapped circular hollow structure (CHS) K-joints was generated and validated by comparing the ultimate capacities, deformation processes and failure modes of the experimental results. Using this model, the stress distribution, propagation of plasticity and the failure modes of overlapped joints with through-brace-in-compression and welded hidden seams were analyzed. The effect of geometric parameters, with or without hidden welds, and the loading hierarchy reversal of braces on the ultimate capacity of the joints were also studied. The results of finite element parametric analysis indicate that the brace-to-chord thickness ratio has relatively large effects on the failure mechanism and ultimate capacity of overlapped joints. It was also found that the absence of hidden welds has less significance on the ultimate capacity of through-brace-in-compression joints than through-brace-in tension joints. Finally, based on the design equation of gap joints, a formula predicting the ultimate capacity of overlapped CHS K-joints was derived by applying multivariate regression analysis. Results from the proposed design equation are consistent with experimental results.

关键词： regression analysis     consistent     unstiffened     plasticity     overlapped    

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A novel cataplasma matrix of traditional Chinese medicine

Jing TIAN, Xiaolei ZHANG, Xueqin ZHOU,

《化学科学与工程前沿（英文）》 2010年 第4卷 第1期   页码 91-95 doi: 10.1007/s11705-009-0304-4

摘要： The aim of this paper was to develop a cataplasma matrix that can be applicable to both watersoluble and liposoluble drugs. The gellan gum and konjaku were employed as the scaffold materials of the matrix. With polyacrylic acid sodium and oligosaccharides as tacktifier, the formula of the cataplasma matrix was optimized in the orthogonal method as: gellan gum 0.4 g, xanthan€gum 0.03 g, konjac glue 0.1 g, glycerin 4 g, Gluco-Adhesive T (GAT) 6 g, Gluco-Adhesive E (GAE) 6 g, polyacrylic acid sodium 0.22 g, and sorbitol 3 g. The 180° peel strength, the tensile strength and the elongation at break was 3.043 N, 0.275 MPa and 91.05%, respectively. Furthermore, the drug-compatibilities of the matrix were investigated with baicalin, berberine and curcumin, which were used as the models of hydrophilic, poor-water-soluble and hydrophobic ingredients. The drug contents could reach 4.12% , 2.42% and 3.75%, while the release rate were measured as, 361.79, 55.85 and 104.41 μg·cm·hfor baicalin, berberine and curcumin, respectively. These results indicated that the obtained matrix had good drug-compatibility and drug-release properties for different ingredients.

关键词： drug-release     applicable     berberine     curcumin     different    

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一种损伤演化方程的建立和几种层裂准则的推导

曹结东,李永池

《中国工程科学》 2006年 第8卷 第1期   页码 40-45

摘要：

通过唯象分析和细观统计相结合的方法建立了一种韧性材料的损伤演化方程，从物理上对方程中的参数进行了合理的解释，并以此为依据推导了材料的便于工程应用的几种层裂准则，根据准则总结了一些有意义的层裂规律；通过层裂实验和数值模拟相结合的方法来确定材料参数，计算结果与实验结果较好的一致性验证了所建的损伤演化方程和推导的层裂准则是合理的，决定材料参数的方法是有效的。

关键词： 损伤演化方程     层裂准则     数值模拟    

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numerical framework for underground structures in layered ground under inclined P-SV waves using stiffness matrix

《结构与土木工程前沿（英文）》 2023年 第17卷 第1期   页码 10-24 doi: 10.1007/s11709-022-0904-3

摘要： A numerical framework was proposed for the seismic analysis of underground structures in layered ground under inclined P-SV waves. The free-field responses are first obtained using the stiffness matrix method based on plane-wave assumptions. Then, the domain reduction method was employed to reproduce the wavefield in the numerical model of the soil–structure system. The proposed numerical framework was verified by providing comparisons with analytical solutions for cases involving free-field responses of homogeneous ground, layered ground, and pressure-dependent heterogeneous ground, as well as for an example of a soil–structure interaction simulation. Compared with the viscous and viscous-spring boundary methods adopted in previous studies, the proposed framework exhibits the advantage of incorporating oblique incident waves in a nonlinear heterogeneous ground. Numerical results show that SV-waves are more destructive to underground structures than P-waves, and the responses of underground structures are significantly affected by the incident angles.

关键词： underground structures     seismic response     stiffness matrix method     domain reduction method     P-SV waves    

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标题 作者 时间 类型 操作

Unified method for typical gear failure modeling and stiffness calculation based on the matrix equation

期刊论文

An artificial neural network based deep collocation method for the solution of transient linear and nonlinear partial differential equations

期刊论文

Decellularized extracellular matrix mediates tissue construction and regeneration

期刊论文

Perspective of mixed matrix membranes for carbon capture

Shinji Kanehashi, Colin A. Scholes

期刊论文

Comparison of the performance of traditional advection-dispersion equation and mobile-immobile model

Haizhu HU,Xiaomin MAO

期刊论文

Optimal design of extractive dividing-wall column using an efficient equation-oriented approach

Yingjie Ma, Nan Zhang, Jie Li, Cuiwen Cao

期刊论文

Glycosylation of dentin matrix protein 1 is critical for fracture healing via promoting chondrogenesis

Hui Xue, Dike Tao, Yuteng Weng, Qiqi Fan, Shuang Zhou, Ruilin Zhang, Han Zhang, Rui Yue, Xiaogang Wang, Zuolin Wang, Yao Sun

期刊论文

Role of salivary matrix metalloproteinase-8 (MMP-8) in chronic periodontitis diagnosis

null

期刊论文

Strengthening of reinforced concrete beams using fiber-reinforced cementitious matrix systems fabricated

期刊论文

A dynamic model of mobile concrete pump boom based on discrete time transfer matrix method

Wu REN, Yunxin WU, Zhaowei ZHANG

期刊论文

深水钻井隔水导管挠曲方程和固有频率的计算及其研究

姜伟

期刊论文

Parametric analysis and design equation of ultimate capacity for unstiffened overlapped CHS K-joints

CHEN Yu, ZHAO Xianzhong, CHEN Yiyi

期刊论文

A novel cataplasma matrix of traditional Chinese medicine

Jing TIAN, Xiaolei ZHANG, Xueqin ZHOU,

期刊论文

一种损伤演化方程的建立和几种层裂准则的推导

曹结东,李永池

期刊论文

numerical framework for underground structures in layered ground under inclined P-SV waves using stiffness matrix

期刊论文