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The antibiotic resistome: gene flow in environments, animals and human beings

null

《医学前沿(英文)》 2017年 第11卷 第2期   页码 161-168 doi: 10.1007/s11684-017-0531-x

摘要:

The antibiotic resistance is natural in bacteria and predates the human use of antibiotics. Numerous antibiotic resistance genes (ARGs) have been discovered to confer resistance to a wide range of antibiotics. The ARGs in natural environments are highly integrated and tightly regulated in specific bacterial metabolic networks. However, the antibiotic selection pressure conferred by the use of antibiotics in both human medicine and agriculture practice leads to a significant increase of antibiotic resistance and a steady accumulation of ARGs in bacteria. In this review, we summarized, with an emphasis on an ecological point of view, the important research progress regarding the collective ARGs (antibiotic resistome) in bacterial communities of natural environments, human and animals, i.e., in the one health settings. We propose that the resistance gene flow in nature is “from the natural environments” and “to the natural environments”; human and animals, as intermediate recipients and disseminators, contribute greatly to such a resistance gene “circulation.”

关键词: antibiotic resistance     resistome     microbiome     gene flow    

Influence of initial curing conditions and exposure environments on chloride migration in concrete using

Wen XUE, Weiliang JIN, Hiroshi YOKOTA,

《结构与土木工程前沿(英文)》 2010年 第4卷 第3期   页码 348-353 doi: 10.1007/s11709-010-0077-3

摘要: To investigate the influence of initial curing conditions and exposure environments on chloride ions’ migration in concrete, the specimens that were cured in different conditions and placed in several marine environments were studied. The amount of chloride ions passing through the specimen’s section was monitored in the accelerated chloride migration test. The effective chloride diffusion coefficients () were calculated from the steady-state on the basis of Nernst-Planck’s equation. The results indicated that the initial curing conditions and the wet-dry interval of external environments have coupling influence on effective diffusion coefficient of chloride ion significantly. reflected the density and pore connectivity of concrete. The co-effects of the initial curing condition and following exposure environment should be taken into account in durability design for concrete structure located in marine environment.

关键词: durability     effective diffusion coefficient     steady-state     migration test    

Creating technical heritage object replicas in a virtual environment

Olga EGOROVA,Dmitry SHCHERBININ

《机械工程前沿(英文)》 2016年 第11卷 第1期   页码 108-115 doi: 10.1007/s11465-016-0363-4

摘要:

The paper presents innovative informatics methods for creating virtual technical heritage replicas, which are of significant scientific and practical importance not only to researchers but to the public in general. By performing 3D modeling and animation of aircrafts, spaceships, architectural-engineering buildings, and other technical objects, the process of learning is achieved while promoting the preservation of the replicas for future generations. Modern approaches based on the wide usage of computer technologies attract a greater number of young people to explore the history of science and technology and renew their interest in the field of mechanical engineering.

关键词: 3D document     history of science and technology     technical knowledge     popularization     virtual environment     replica     mechanism and machine science (MMS)    

Macrozoobenthic assemblages in relation to environments of the Yangtze-isolated lakes

Baozhu PAN, Haijun WANG, Hongzhu WANG, Zhaoyin WANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 246-254 doi: 10.1007/s11783-011-0381-8

摘要: Eutrophication can shift lakes from a clear, macrophyte-dominated state to a turbid, algae-dominated state, and different habitat condition supports different fauna. Macrozoobenthos are good indicators of water environment, and studies on macrozoobenthic assemblage characteristics can help us to know which state a lake is in, thus provide the basis for its eutrophication control. In this study, a systematic investigation on macrozoobenthos was conducted in 17 Yangtze-isolated lakes to explore the macroecological laws of macrozoobenthic assemblages. Detrended correspondence analysis (DCA) revealed that variance of benthic assemblage structure occurred in two types of lakes. In macrophytic lakes, altogether 51?taxa of macrozoobenthos were identified. The average density and biomass of total macrozoobenthos were 2231?individuals·m and 1.69 g dry weight·m , respectively. Macrozoobenthic assemblage was characterized by dominance of scrapers (i.e. gastropods). In algal lakes, altogether 20 taxa of macrozoobenthos were identified. The average density and biomass of total macrozoobenthos were 2814 individuals·m and 1.38 g dry weight·m , respectively. Macrozoobenthic assemblage was characterized by dominance of collector-gatherers (i.e. oligochaetes). Wet biomass of submersed macrophytes ( ) and phytoplankton chlorophyll concentration ( ) were demonstrated as the key factor structuring macrozoobenthic assemblages in macrophytic and algal lakes, respectively.

关键词: macrozoobenthos     assemblage characteristics     environment analyses     macrophytic lake     algal lake    

Understanding building-occupant-microbiome interactions toward healthy built environments: A review

Shuai Li, Zhiyao Yang, Da Hu, Liu Cao, Qiang He

《环境科学与工程前沿(英文)》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1357-3

摘要: Abstract • The built environment, occupants, and microbiomes constitute an integrated ecosystem. • This review summarizes research progress which has focused primarily on microbiomes. • Critical research needs include studying impacts of occupant behaviors on microbiomes. Built environments, occupants, and microbiomes constitute a system of ecosystems with extensive interactions that impact one another. Understanding the interactions between these systems is essential to develop strategies for effective management of the built environment and its inhabitants to enhance public health and well-being. Numerous studies have been conducted to characterize the microbiomes of the built environment. This review summarizes current progress in understanding the interactions between attributes of built environments and occupant behaviors that shape the structure and dynamics of indoor microbial communities. In addition, this review also discusses the challenges and future research needs in the field of microbiomes of the built environment that necessitate research beyond the basic characterization of microbiomes in order to gain an understanding of the causal mechanisms between the built environment, occupants, and microbiomes, which will provide a knowledge base for the development of transformative intervention strategies toward healthy built environments. The pressing need to control the transmission of SARS-CoV-2 in indoor environments highlights the urgency and significance of understanding the complex interactions between the built environment, occupants, and microbiomes, which is the focus of this review.

关键词: Microbiome     Built Environment     Occupant     Health    

Isolating higher yielding and more stable rice genotypes in stress environments: fine-tuning a selection

《农业科学与工程前沿(英文)》 doi: 10.15302/J-FASE-2023521

摘要:

● Score index methods readily discriminate genotypes adapted to a target environment.

关键词: Aerobic rice     breeding selection     drought resilience     production capacity index     resilience capacity index     stress score index     upland    

Development of a hydrodynamic model and the corresponding virtual software for dual-loop circulating

Shanwei Hu, Xinhua Liu

《化学科学与工程前沿(英文)》 2021年 第15卷 第3期   页码 579-590 doi: 10.1007/s11705-020-1953-6

摘要: Dual-loop circulating fluidized bed (CFB) reactors have been widely applied in industry because of their good heat and mass transfer characteristics and continuous handling ability. However, the design of such reactors is notoriously difficult owing to the poor understanding of the underlying mechanisms, meaning it has been heavily based on empiricism and stepwise experiments. Modeling the gas-solid CFB system requires a quantitative description of the multiscale heterogeneity in the sub-reactors and the strong coupling between them. This article proposed a general method for modeling multi-loop CFB systems by utilizing the energy minimization multiscale (EMMS) principle. A full-loop modeling scheme was implemented by using the EMMS model and/or its extension models to compute the hydrodynamic parameters of the sub-reactors, to achieve the mass conservation and pressure balance in each circulation loop. Based on the modularization strategy, corresponding interactive simulation software was further developed to facilitate the flexible creation and fast modeling of a customized multi-loop CFB reactor. This research can be expected to provide quantitative references for the design and scale-up of gas-solid CFB reactors and lay a solid foundation for the realization of virtual process engineering.

关键词: multi-loop circulating fluidized bed     mathematical modeling     energy minimization multiscale     virtual fluidization     mesoscale structure    

A virtual reality system for arm and hand rehabilitation

Zhiqiang LUO, Chee Kian LIM, I-Ming CHEN, Song Huat YEO

《机械工程前沿(英文)》 2011年 第6卷 第1期   页码 23-32 doi: 10.1007/s11465-011-0202-6

摘要:

This paper presents a virtual reality (VR) system for upper limb rehabilitation. The system incorporates two motion track components, the Arm Suit and the Smart Glove which are composed of a range of the optical linear encoders (OLE) and the inertial measurement units (IMU), and two interactive practice applications designed for driving users to perform the required functional and non-functional motor recovery tasks. We describe the technique details about the two motion track components and the rational to design two practice applications. The experiment results show that, compared with the marker-based tracking system, the Arm Suit can accurately track the elbow and wrist positions. The repeatability of the Smart Glove on measuring the five fingers’ movement can be satisfied. Given the low cost, high accuracy and easy installation, the system thus promises to be a valuable complement to conventional therapeutic programs offered in rehabilitation clinics and at home.

关键词: motion tracking     rehabilitation     optical linear encoder (OLE)     virtual reality    

基于网格服务的协同虚拟环境

张谞,吴慧中,肖亮

《中国工程科学》 2007年 第9卷 第11期   页码 157-162

摘要:

由于计算资源、网络资源以及现有技术的限制,协同虚拟环境的扩展性问题至今没有得到很好的解 决。针对这一问题,讨论了大规模协同虚拟环境的通信模式,提出了一个基于开放网格服务结构OGSA的协 同虚拟环境体系结构,利用网格服务封装将系统功能实现与具体的物理资源相分离以达到系统可扩展的目 的。另外,还重点研究了影响协同虚拟环境扩展性的关键技术———虚拟世界管理服务以及相关的支撑服务。 最后基于Globus Toolkit开发了一个协同虚拟环境示例程序,验证所提出的框架和方法的可行性。

关键词: 协同虚拟环境     开放网格服务结构     虚拟世界管理     扩展性    

虚拟企业和谐机制研究

王硕,唐小我

《中国工程科学》 2004年 第6卷 第4期   页码 82-85

摘要:

文章运用和谐理论与方法,探讨虚拟企业运作与发展要素划分、现状和谐性分析,研究其和谐机制,据此可随时分析虚拟企业系统的和谐状态,以针对性改进其运行,最后给出案例研究。

关键词: 虚拟企业     和谐机制     协调     要素    

Research on constraint-based virtual assembly technologies

YANG Rundang, WU Dianliang, FAN Xiumin, YAN Juanqi

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 243-249 doi: 10.1007/s11465-007-0043-5

摘要: To realize a constraint-based virtual assembly operation, the unified representations of the assembly constraint, the equivalent relation between the constraint and the degree of freedom (DOF), and the movement DOF reduction in a virtual environment are proposed. Several algorithms about the constraint treatment are submitted. First, the automatic recognition algorithm based on the assembly relation is used to determine the position and orientation relation between two geometry elements of constraint whether they meet the given errors. Second, to satisfy the new constraint, according to the positing solving algorithm, the position and orientation of an active part are modified with minimal adjustment after the part has satisfied the affirmed constraints. Finally, the algorithm of movement navigation based on the generalized coordinate system is put forward, and the part movement is guided. These algorithms have been applied to the integrated virtual assembly environment (IVAE) system. Experiments have indicated that these algorithms have well supported constraint treatments in the IVAE and realized the closer combination of the virtual and the real assembly processes.

关键词: movement DOF     recognition algorithm     assembly     orientation     combination    

Digital design of a combine harvester using virtual prototyping

YAN Chuliang, LI Jie, ZHANG Shuming, YANG Fangfei

《机械工程前沿(英文)》 2007年 第2卷 第2期   页码 159-163 doi: 10.1007/s11465-007-0026-6

摘要: A parametric feature-based modeling was used to model the parts of a combine harvester. The digital virtual prototyping of the harvester was completed by virtual assembly. The finite element analysis of the vehicle frame was made and the result satisfied the requirements. The vibration sieve, which is a key part of the combine harvester, was simulated and optimized. The excellent parameters of the vibration were gained by optimization. The grain passed through the sieve easily after the optimization and reduced the loss rate and impurity rate in theory.

关键词: excellent     assembly     impurity     harvester     vibration    

大西线南水北调虚拟仿真方法论

李伯衡

《中国工程科学》 2003年 第5卷 第5期   页码 19-23

摘要:

南水北调工程已正式列入“十五”计划,近期南水北调工程主要是东线和中线开工建设。文章论述了大西线南水北调的必要性和研究路线;论述了采用数字地球虚拟仿真技术研究西南诸外流主河的调水可行性,包括调水量、地质基础、调水路线优化、环境效益的研究方法和研究路线。

关键词: 西线调水     虚拟     方法论    

Carbon emission impact on the operation of virtual power plant with combined heat and power system

Yu-hang XIA,Jun-yong LIU,Zheng-wen HUANG,Xu ZHANG

《信息与电子工程前沿(英文)》 2016年 第17卷 第5期   页码 479-488 doi: 10.1631/FITEE.1500467

摘要: A virtual power plant (VPP) can realize the aggregation of distributed generation in a certain region, and represent distributed generation to participate in the power market of the main grid. With the expansion of VPPs and ever-growing heat demand of consumers, managing the effect of fluctuations in the amount of available renewable resources on the operation of VPPs and maintaining an economical supply of electric power and heat energy to users have been important issues. This paper proposes the allocation of an electric boiler to realize wind power directly converted for supplying heat, which can not only overcome the limitation of heat output from a combined heat and power (CHP) unit, but also reduce carbon emissions from a VPP. After the electric boiler is considered in the VPP operation model of the combined heat and power system, a multi-objective model is built, which includes the costs of carbon emissions, total operation of the VPP and the electricity traded between the VPP and the main grid. The model is solved by the CPLEX package using the fuzzy membership function in Matlab, and a case study is presented. The power output of each unit in the case study is analyzed under four scenarios. The results show that after carbon emission is taken into account, the output of low carbon units is significantly increased, and the allocation of an electric boiler can facilitate the maximum absorption of renewable energy, which also reduces carbon emissions from the VPP.

关键词: Virtual power plant (VPP)     Carbon emissions     Electric boiler     Wind power     Combined heat and power (CHP)    

Design and modeling of continuum robot based on virtual-center of motion mechanism

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0739-6

摘要: Continuum robot has attracted extensive attention since its emergence. It has multi-degree of freedom and high compliance, which give it significant advantages when traveling and operating in narrow spaces. The flexural virtual-center of motion (VCM) mechanism can be machined integrally, and this way eliminates the assembly between joints. Thus, it is well suited for use as a continuum robot joint. Therefore, a design method for continuum robots based on the VCM mechanism is proposed in this study. First, a novel VCM mechanism is formed using a double leaf-type isosceles-trapezoidal flexural pivot (D-LITFP), which is composed of a series of superimposed LITFPs, to enlarge its stroke. Then, the pseudo-rigid body (PRB) model of the leaf is extended to the VCM mechanism, and the stiffness and stroke of the D-LITFP are modeled. Second, the VCM mechanism is combined to form a flexural joint suitable for the continuum robot. Finally, experiments and simulations are used to validate the accuracy and validity of the PRB model by analyzing the performance (stiffness and stroke) of the VCM mechanism. Furthermore, the motion performance of the designed continuum robot is evaluated. Results show that the maximum stroke of the VCM mechanism is approximately 14.2°, the axial compressive strength is approximately 1915 N/mm, and the repeatable positioning accuracies of the continuum robot is approximately ±1.47° (bending angle) and ±2.46° (bending direction).

关键词: VCM mechanism     continuum robot     flexural joint     pseudo-rigid body model     cable-driven    

标题 作者 时间 类型 操作

The antibiotic resistome: gene flow in environments, animals and human beings

null

期刊论文

Influence of initial curing conditions and exposure environments on chloride migration in concrete using

Wen XUE, Weiliang JIN, Hiroshi YOKOTA,

期刊论文

Creating technical heritage object replicas in a virtual environment

Olga EGOROVA,Dmitry SHCHERBININ

期刊论文

Macrozoobenthic assemblages in relation to environments of the Yangtze-isolated lakes

Baozhu PAN, Haijun WANG, Hongzhu WANG, Zhaoyin WANG

期刊论文

Understanding building-occupant-microbiome interactions toward healthy built environments: A review

Shuai Li, Zhiyao Yang, Da Hu, Liu Cao, Qiang He

期刊论文

Isolating higher yielding and more stable rice genotypes in stress environments: fine-tuning a selection

期刊论文

Development of a hydrodynamic model and the corresponding virtual software for dual-loop circulating

Shanwei Hu, Xinhua Liu

期刊论文

A virtual reality system for arm and hand rehabilitation

Zhiqiang LUO, Chee Kian LIM, I-Ming CHEN, Song Huat YEO

期刊论文

基于网格服务的协同虚拟环境

张谞,吴慧中,肖亮

期刊论文

虚拟企业和谐机制研究

王硕,唐小我

期刊论文

Research on constraint-based virtual assembly technologies

YANG Rundang, WU Dianliang, FAN Xiumin, YAN Juanqi

期刊论文

Digital design of a combine harvester using virtual prototyping

YAN Chuliang, LI Jie, ZHANG Shuming, YANG Fangfei

期刊论文

大西线南水北调虚拟仿真方法论

李伯衡

期刊论文

Carbon emission impact on the operation of virtual power plant with combined heat and power system

Yu-hang XIA,Jun-yong LIU,Zheng-wen HUANG,Xu ZHANG

期刊论文

Design and modeling of continuum robot based on virtual-center of motion mechanism

期刊论文