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Optimization of the mechanical performance and damage failure characteristics of laminated composites based on fiber orientation

《结构与土木工程前沿(英文)》   页码 1357-1369 doi: 10.1007/s11709-023-0996-4

摘要: In this study, the effect of fiber angle on the tensile load-bearing performance and damage failure characteristics of glass composite laminates was investigated experimentally, analytically, and numerically. The glass fabric in the laminate was perfectly aligned along the load direction (i.e., at 0°), offset at angles of 30° and 45°, or mixed in different directions (i.e., 0°/30° or 0°/45°). The composite laminates were fabricated using vacuum-assisted resin molding. The influence of fiber orientation angle on the mechanical properties and stiffness degradation of the laminates was studied via cyclic tensile strength tests. Furthermore, simulations have been conducted using finite element analysis and analytical approaches to evaluate the influence of fiber orientation on the mechanical performance of glass laminates. Experimental testing revealed that, although the composite laminates laid along the 0° direction exhibited the highest stiffness and strength, their structural performance deteriorated rapidly. We also determined that increasing the fiber offset angle (i.e., 30°) could optimize the mechanical properties and damage failure characteristics of glass laminates. The results of the numerical and analytical approaches demonstrated their ability to capture the mechanical behavior and damage failure modes of composite laminates with different fiber orientations, which may be used to prevent the catastrophic failures that occur in composite laminates.

关键词: fiber orientation     composite laminates     stiffness degradation     analytical approaches     finite element analysis    

CORRECTION to: Energy-saving operation approaches for urban rail transit systems

Ziyou GAO, Lixing YANG

《工程管理前沿(英文)》   页码 698-698 doi: 10.1007/s42524-019-0047-y

Traditional Chinese medicine: potential approaches from modern dynamical complexity theories

null

《医学前沿(英文)》 2016年 第10卷 第1期   页码 28-32 doi: 10.1007/s11684-016-0434-2

摘要:

Despite the widespread use of traditional Chinese medicine (TCM) in clinical settings, proving its effectiveness via scientific trials is still a challenge. TCM views the human body as a complex dynamical system, and focuses on the balance of the human body, both internally and with its external environment. Such fundamental concepts require investigations using system-level quantification approaches, which are beyond conventional reductionism. Only methods that quantify dynamical complexity can bring new insights into the evaluation of TCM. In a previous article, we briefly introduced the potential value of Multiscale Entropy (MSE) analysis in TCM. This article aims to explain the existing challenges in TCM quantification, to introduce the consistency of dynamical complexity theories and TCM theories, and to inspire future system-level research on health and disease.

关键词: traditional Chinese medicine     quantification     dynamical complexity     system level     balance     modern sciences    

Stem cell gene therapy: the risks of insertional mutagenesis and approaches to minimize genotoxicity

Chuanfeng Wu, Cynthia E. Dunbar

《医学前沿(英文)》 2011年 第5卷 第4期   页码 356-371 doi: 10.1007/s11684-011-0159-1

摘要: Virus-based vectors are widely used in hematopoietic stem cell (HSC) gene therapy, and have the ability to integrate permanently into genomic DNA, thus driving long-term expression of corrective genes in all hematopoietic lineages. To date, HSC gene therapy has been successfully employed in the clinic for improving clinical outcomes in small numbers of patients with X-linked severe combined immunodeficiency (SCID-X1), adenosine deaminase deficiency (ADA-SCID), adrenoleukodystrophy (ALD), thalassemia, chronic granulomatous disease (CGD), and Wiskott-Aldrich syndrome (WAS). However, adverse events were observed during some of these HSC gene therapy clinical trials, linked to insertional activation of proto-oncogenes by integrated proviral vectors leading to clonal expansion and eventual development of leukemia. Numerous studies have been performed to understand the molecular basis of vector-mediated genotoxicity, with the aim of developing safer vectors and lower-risk gene therapy protocols. This review will summarize current information on the mechanisms of insertional mutagenesis in hematopoietic stem and progenitor cells due to integrating gene transfer vectors, discuss the available assays for predicting genotoxicity and mapping vector integration sites, and introduce newly-developed approaches for minimizing genotoxicity as a way to further move HSC gene therapy forward into broader clinical application.

关键词: gene therapy     hematopoietic stem cells     insertional mutagenesis     genotoxicity     induced pluripotent stem cell    

Lightweight design of an electric bus body structure with analytical target cascading

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0718-y

摘要: Lightweight designs of new-energy vehicles can reduce energy consumption, thereby improving driving mileage. In this study, a lightweight design of a newly developed multi-material electric bus body structure is examined in combination with analytical target cascading (ATC). By proposing an ATC-based two-level optimization strategy, the original lightweight design problem is decomposed into the system level and three subsystem levels. The system-level optimization model is related to mass minimization with all the structural modal frequency constraints, while each subsystem-level optimization model is related to the sub-structural performance objective with sub-structure mass constraints. To enhance the interaction between two-level systems, each subsystem-level objective is reformulated as a penalty-based function coordinated with the system-level objective. To guarantee the accuracy of the model-based analysis, a finite element model is validated through experimental modal test. A sequential quadratic programming algorithm is used to address the defined optimization problem for effective convergence. Compared with the initial design, the total mass is reduced by 49 kg, and the torsional stiffness is increased by 17.5%. In addition, the obtained design is also validated through strength analysis.

关键词: electric vehicle     body in white (BIW)     lightweight     analytical target cascading (ATC)    

DESIGNING DIVERSIFIED CROPPING SYSTEMS IN CHINA: THEORY, APPROACHES AND IMPLEMENTATION

《农业科学与工程前沿(英文)》 2021年 第8卷 第3期   页码 362-372 doi: 10.15302/J-FASE -2021392

摘要:

Intensive agriculture in China over recent decades has successfully realized food security but at the expense of negative environmental impacts. Achieving green transformation of agriculture in China requires fundamental restructuring of cropping systems. This paper presents a theoretical framework of theory, approaches and implementation of crop diversification schemes in China. Initially, crop diversification schemes require identifying multiple objectives by simultaneously considering natural resources, limiting factors/constraints, and social and economic demands of different stakeholders. Then, it is necessary to optimize existing and/or design novel cropping systems based upon farming practices and ecological principles, and to strengthen targeted ecosystem services to achieve the identified objectives. Next, the resulting diversified cropping systems need to be evaluated and examined by employing experimental and modeling approaches. Finally, a strategic plan, as presented in this paper, is needed for implementing an optimized crop diversification in China based upon regional characteristics with the concurrent objectives of safe, nutritious food production and environmental protection. The North China Plain is used as an example to illustrate the strategic plan to optimize and design diversified cropping systems. The implementation of crop diversification in China will set an example for other countries undergoing agricultural transition, and contribute to global sustainable development.

 

关键词: Agriculture Green Development , crop diversification , cropping system modeling , ecosystem services , sustainable agriculture    

Detection and monitoring prostate specific antigen using nanotechnology approaches to biosensing

Grant Perry, Fernando Cortezon-Tamarit, Sofia I. Pascu

《化学科学与工程前沿(英文)》 2020年 第14卷 第1期   页码 4-18 doi: 10.1007/s11705-019-1846-8

摘要: Prostate cancer has a high incidence in men and remains the second cause of mortality due to cancer. As the development of the disease is greatly correlated to age, the identification of novel detection methods reliable, efficient, and cost effective is a matter of significant importance in the ageing population of western societies. The detection of the prostate specific antigen (PSA) in blood samples has been the preferred method for the detection and monitoring of prostate cancer over the past decades. Despite the indications against its use in massive population screening, PSA still remains the best studied biomarker for prostate cancer and the detection of its different forms and incorporation in multiplexed designs with other biomarkers still remains a highly valuable indicator in the theranostics of prostate cancer. The latest developments in the use of nanomaterials towards the construction of PSA biosensors are reviewed hereby. The incorporation of gold nanoparticles, silica nanoparticles and graphene nanostructures to biosensing devices has represented a big leap forward in terms of sensitivity, stability and miniaturization. Both electrochemical and optical detection methods will be reviewed herein for the detection of PSA.

关键词: biosensing     immunosensor     PSA     prostate cancer     fluorescence    

Adiponectin: mechanisms and new therapeutic approaches for restoring diabetic heart sensitivity to ischemic

null

《医学前沿(英文)》 2013年 第7卷 第3期   页码 301-305 doi: 10.1007/s11684-013-0283-1

摘要:

Systemic inflammatory response following myocardial ischemia-reperfusion injury (IRI) to a specific organ may cause injuries. Ischemic post-conditioning (IPostC) has emerged as a promising method for myocardial protection against IRI both in experimental and in clinical settings. Enhancement of endogenous nitric oxide (NO) is one of the major mechanisms by which IPostC confers cardioprotection. However, the sensitivity of the diabetic heart to IPostC is impaired and the underlying mechanism is unknown. Adiponectin (APN) is an adipocyte-derived plasma protein with anti-diabetic and anti-inflammatory properties. Plasma levels of APN are decreased in obese subjects and in patients with type 2 diabetes. APN supplementation has been shown to increase NO production and attenuate myocardial IRI in normal (non-diabetic) animals. However, the effect of APN on myocardial injury in diabetic subjects, especially its potential in restoring the sensitivity of the diabetic heart to IPostC has not been investigated. In the current paper, we discussed the possible reasons why the myocardium of diabetic subjects loses sensitivity to IPostC and also highlighted the potential effectiveness and mechanism of APN in restoring IPostC cardioprotection in diabetes. This review proposes to conduct studies that may facilitate the development of novel and optimal therapies to enhance cardioprotection in patients with severe diseases such as diabetes.

关键词: adiponectin     ischemic post-conditioning     ischemia reperfusion injury     diabetes    

OPPORTUNITIES AND APPROACHES FOR MANIPULATING SOIL-PLANT MICROBIOMES FOR EFFECTIVE CROP NITROGEN USE

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 333-343 doi: 10.15302/J-FASE-2022450

摘要:

● Matching nitrification inhibitors with soil properties and nitrifiers is vital to achieve a higher NUE.

关键词: nitrogen     microbiome     NUE     rhizosphere     phyllosphere     soil food web    

Improved analytical model for residual stress prediction in orthogonal cutting

null

《机械工程前沿(英文)》 2014年 第9卷 第3期   页码 249-256 doi: 10.1007/s11465-014-0310-1

摘要:

The analytical model of residual stress in orthogonal cutting proposed by Jiann is an important tool for residual stress prediction in orthogonal cutting. In application of the model, a problem of low precision of the surface residual stress prediction is found. By theoretical analysis, several shortages of Jiann’s model are picked out, including: inappropriate boundary conditions, unreasonable calculation method of thermal stress, ignorance of stress constraint and cyclic loading algorithm. These shortages may directly lead to the low precision of the surface residual stress prediction. To eliminate these shortages and make the prediction more accurate, an improved model is proposed. In this model, a new contact boundary condition between tool and workpiece is used to make it in accord with the real cutting process; an improved calculation method of thermal stress is adopted; a stress constraint is added according to the volume-constancy of plastic deformation; and the accumulative effect of the stresses during cyclic loading is considered. At last, an experiment for measuring residual stress in cutting AISI 1045 steel is conducted. Also, Jiann’s model and the improved model are simulated under the same conditions with cutting experiment. The comparisons show that the surface residual stresses predicted by the improved model is closer to the experimental results than the results predicted by Jiann’s model.

关键词: residual stress     analytical model     orthogonal cutting     cutting force     cutting temperature    

Uncertainty propagation in dynamics of composite plates: A semi-analytical non-sampling-based approach

Mahdi FAKOOR, Hadi PARVIZ

《结构与土木工程前沿(英文)》 2020年 第14卷 第6期   页码 1359-1371 doi: 10.1007/s11709-020-0658-8

摘要: In this study, the influences of spatially varying stochastic properties on free vibration analysis of composite plates were investigated via development of a new approach named the deterministic-stochastic Galerkin-based semi-analytical method. The material properties including tensile modulus, shear modulus, and density of the plate were assumed to be spatially varying and uncertain. Gaussian fields with first-order Markov kernels were utilized to define the aforementioned material properties. The stochastic fields were decomposed via application of the Karhunen-Loeve theorem. A first-order shear deformation theory was assumed, following which the displacement field was defined using admissible trigonometric modes to derive the potential and kinetic energies. The stochastic equations of motion of the plate were obtained using the variational principle. The deterministic-stochastic Galerkin-based method was utilized to find the probability space of natural frequencies, and the corresponding mode shapes of the plate were determined using a polynomial chaos approach. The proposed method significantly reduced the size of the mathematical models of the structure, which is very useful for enhancing the computational efficiency of stochastic simulations. The methodology was verified using a stochastic finite element method and the available results in literature. The sensitivity of natural frequencies and corresponding mode shapes due to the uncertainty of material properties was investigated, and the results indicated that the higher-order modes are more sensitive to uncertainty propagation in spatially varying properties.

关键词: composite plate     spatially varying stochastic properties     Galerkin method     polynomial chaos approach     semi-analytical approach    

Critical flow-storm approach to total maximum daily load (TMDL) development: an analytical conceptual

Zhang Harry, Yu Shaw

《环境科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 267-273 doi: 10.1007/s11783-008-0058-0

摘要: One of the key challenges in the total maximum daily load (TMDL) development process is how to define the critical condition for a receiving waterbody. The main concern in using a continuous simulation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scarcity of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continuous and event-based approaches in defining critical condition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the critical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having certain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.

关键词: representative hydrologic     occurrence     simulation approach     scarcity     alternative    

Contribution of national bioassessment approaches for assessing ecological water security: an AUSRIVAS

Susan J. NICHOLS, Fiona J. DYER

《环境科学与工程前沿(英文)》 2013年 第7卷 第5期   页码 669-687 doi: 10.1007/s11783-013-0556-6

摘要: River managers in Australia are managing in the face of extremes to provide security of water supply for people, production and the environment. Balancing the water requirements of people, environments and economies requires that water security is viewed holistically, not just in terms of the water available for human consumption. Common definitions of water security focus on the needs of both humans and ecosystems for purposes such as drinking, agriculture and industrial use, and to maintain ecological values. Information about achieving water security for the environment or ecological purposes can be a challenge to interpret because the watering requirements of key ecological processes or assets are not well understood, and the links between ecological and human values are often not obvious to water users. Yet the concepts surrounding river health are inherently linked to holistic concepts of water security. The measurement of aquatic biota provides a valuable tool for managers to understand progress toward achieving ecological water security objectives. This paper provides a comprehensive review of the reference condition approach to river health assessment, using the development of the Australian River Assessment System (AUSRIVAS) as a case study. We make the link between the biological assessment of river health and assessment of ecological water security, and suggest that such an approach provides a way of reporting that is relevant to the contribution made by ecosystems to water security. The reference condition approach, which is the condition representative of minimally disturbed sites organized by selected physical, chemical, and biological characteristics, is most important for assessing ecological water security objectives.

关键词: ecological water security     biological assessment     river health    

Energy-saving operation approaches for urban rail transit systems

Ziyou GAO, Lixing YANG

《工程管理前沿(英文)》 2019年 第6卷 第2期   页码 139-151 doi: 10.1007/s42524-019-0030-7

摘要: With the accelerated urbanization in China, passenger demand has dramatically increased in large cities, and traffic congestion has become serious in recent years. Developing public urban rail transit systems is an indispensable approach to overcome these problems. However, the high energy consumption of daily operations is an emerging issue due to increased rail transit networks and passenger demands. Thus, reducing the energy consumption and operational cost by using advanced optimization methodologies is an urgent task for operation managers. This work systematically introduces energy-saving approaches for urban rail transit systems in three aspects, namely, train speed profile optimization, utilization of regenerative energy, and integrated optimization of train timetable and speed profile. Future research directions in this field are also proposed to meet increasing passenger demands and network-based urban rail transit systems.

关键词: urban rail transit     energy saving     speed profile optimization     regenerative energy     train timetable    

Novel synthetic approaches and TWC catalytic performance of flower-like Pt/CeO

Zongcheng ZHAN,Xiaojun LIU,Dongzhu MA,Liyun SONG,Jinzhou LI,Hong HE,Hongxing DAI

《环境科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 483-495 doi: 10.1007/s11783-013-0595-z

摘要: A novel Ultrasonic Assisted Membrane Reduction (UAMR)-hydrothermal method was used to prepare flower-like Pt/CeO catalysts. The texture, physical/chemical properties, and reducibility of the flower-like Pt/CeO catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), N adsorption, and hydrogen temperature programmed reduction (H -TPR) techniques. The catalytic performance of the catalysts for treating automobile emission was studied relative to samples prepared by the conventional wetness impregnation method. The Pt/CeO catalysts fabricated by this novel method showed high specific surface area and metal dispersion, excellent three-way catalytic activity, and good thermal stability. The strong interaction between the Pt nanoparticles and CeO improved the thermal stability. The Ce ions were incorporated into the surfactant chains and the Pt nanoparticles were stabilized through an exchange reaction of the surface hydroxyl groups. The SEM results demonstrated that the Pt/CeO catalysts had a typical three-dimensional (3D) hierarchical porous structure, which was favorable for surface reaction and enhanced the exposure degree of the Pt nanoparticles. In brief, the flower-like Pt/CeO catalysts prepared by UAMR-hydrothermal method exhibited a higher Pt metal dispersion, smaller particle size, better three-way catalytic activity, and improved thermal stability versus conventional materials.

关键词: three-way catalyst     flower-like     Ultrasonic Assisted Membrane Reduction (UAMR)     Pt nanoparticles    

标题 作者 时间 类型 操作

Optimization of the mechanical performance and damage failure characteristics of laminated composites based on fiber orientation

期刊论文

CORRECTION to: Energy-saving operation approaches for urban rail transit systems

Ziyou GAO, Lixing YANG

期刊论文

Traditional Chinese medicine: potential approaches from modern dynamical complexity theories

null

期刊论文

Stem cell gene therapy: the risks of insertional mutagenesis and approaches to minimize genotoxicity

Chuanfeng Wu, Cynthia E. Dunbar

期刊论文

Lightweight design of an electric bus body structure with analytical target cascading

期刊论文

DESIGNING DIVERSIFIED CROPPING SYSTEMS IN CHINA: THEORY, APPROACHES AND IMPLEMENTATION

期刊论文

Detection and monitoring prostate specific antigen using nanotechnology approaches to biosensing

Grant Perry, Fernando Cortezon-Tamarit, Sofia I. Pascu

期刊论文

Adiponectin: mechanisms and new therapeutic approaches for restoring diabetic heart sensitivity to ischemic

null

期刊论文

OPPORTUNITIES AND APPROACHES FOR MANIPULATING SOIL-PLANT MICROBIOMES FOR EFFECTIVE CROP NITROGEN USE

期刊论文

Improved analytical model for residual stress prediction in orthogonal cutting

null

期刊论文

Uncertainty propagation in dynamics of composite plates: A semi-analytical non-sampling-based approach

Mahdi FAKOOR, Hadi PARVIZ

期刊论文

Critical flow-storm approach to total maximum daily load (TMDL) development: an analytical conceptual

Zhang Harry, Yu Shaw

期刊论文

Contribution of national bioassessment approaches for assessing ecological water security: an AUSRIVAS

Susan J. NICHOLS, Fiona J. DYER

期刊论文

Energy-saving operation approaches for urban rail transit systems

Ziyou GAO, Lixing YANG

期刊论文

Novel synthetic approaches and TWC catalytic performance of flower-like Pt/CeO

Zongcheng ZHAN,Xiaojun LIU,Dongzhu MA,Liyun SONG,Jinzhou LI,Hong HE,Hongxing DAI

期刊论文