Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 321

年份

2023 22

2022 20

2021 25

2020 26

2019 24

2018 18

2017 26

2016 11

2015 11

2014 6

2013 17

2012 9

2011 17

2010 8

2009 10

2008 11

2007 14

2006 19

2005 5

2004 1

展开︾

关键词

实时监控 4

仿真 3

时间序列 3

CAN总线 2

天基信息 2

实时控制 2

实时服务 2

实时荧光定量PCR 2

2 Mb/s高速信令 1

2035年 1

2型糖尿病 1

4D打印 1

ARMA模型 1

ATP荧光检测 1

BRT专用道 1

CMA 1

Cu(Inx 1

DNA 1

GDMS 1

展开︾

检索范围：

排序：展示方式：

Long-lasting photoluminescence quantum yield of cesium lead halide perovskite-type quantum dots

Yonghyun Kim, Huiwen Liu, Yi Liu, Boa Jin, Hao Zhang, Wenjing Tian, Chan Im

《化学科学与工程前沿（英文）》 2021年第15卷第1期页码 187-197 doi: 10.1007/s11705-020-1931-z

摘要： Cesium lead halide perovskite (CsPbX , X= Cl, Br, I) quantum dots (QDs) and their partly Mn -substituted QDs (CsPb Mn X ) attract considerable attention owing to their unique photoluminescence (PL) efficiencies. The two types of QDs, having different PL decay dynamics, needed to be further investigated in a form of aggregates to understand their solid-state-induced exciton dynamics in conjunction with their behaviors upon degradation to achieve practical applications of those promising QDs. However, thus far, these QDs have not been sufficiently investigated to obtain deep insights related to the long-term stability of their PL properties as aggregated solid-states. Therefore, in this study, we comparatively examined CsPbX - and CsPb Mn X -type QDs stocked for>50 d under dark ambient conditions by using excitation wavelength-dependent PL quantum yield and time-resolved PL spectroscopy. These investigations were performed with powder samples in addition to solutions to determine the influence of the inter-QD interaction of the aged QD aggregates on their radiative decays. It turns out that the Mn -substituted QDs exhibited long-lasting PL quantum efficiencies, while the unsubstituted CsPbX -type QDs exhibited a drastic reduction of their PL efficiencies. And the obtained PL traces were clearly sensitive to the sample status. This is discussed with the possible interaction depending on the size and distance of the QD aggregates.

关键词： quantum dots cesium lead halide perovskite time-resolved photoluminescence PL quantum yield QD aggregates

HTML PDF 收藏

Engineering

Raquel Portela, Susana Perez-Ferreras, Ana Serrano-Lotina, Miguel A. Bañares

《化学科学与工程前沿（英文）》 2018年第12卷第3期页码 509-536 doi: 10.1007/s11705-018-1740-9

摘要：

The term operando was coined at the beginning of this century to gather the growing efforts devoted to establish structure-activity relationships by simultaneously characterizing a catalyst performance and the relevant surface chemistry during genuine catalytic operation. This approach is now widespread and consolidated; it has become an increasingly complex but efficient junction where spectroscopy, materials science, catalysis and engineering meet. While for some characterization techniques kinetically relevant reactor cells with good resolution are recently developing, the knowledge gained with magnetic resonance and X-ray and vibrational spectroscopy studies is already huge and the scope of operando methodology with these techniques is recently expanding from studies with small amounts of powdered solids to more industrially relevant catalytic systems. Engineering catalysis implies larger physical domains, and thus all sort of gradients. Space- and time- resolved multi-technique characterization of both the solid and fluid phases involved in heterogeneous catalytic reactions (including temperature data) is key to map processes from different perspectives, which allows taking into account existing heterogeneities at different scales and facing up- and down-scaling for applications ranging from microstructured reactors to industrial-like macroreactors (operating with shaped catalytic bodies and/or in integral regime). This work reviews how operando methodology is evolving toward engineered reaction systems.

关键词： operando structured catalysts space-resolved time-resolved spectroscopy

HTML PDF 收藏

Synthesis of Ag and Cd nanoparticles by nanosecond pulsed discharge in liquid nitrogen

Mahmoud Trad, Alexandre Nominé, Natalie Tarasenka, Jaafar Ghanbaja, Cédric Noël, Malek Tabbal, Thierry Belmonte

《化学科学与工程前沿（英文）》 2019年第13卷第2期页码 360-368 doi: 10.1007/s11705-019-1802-7

摘要： The synthesis of CdO, Ag O (5 nm) and Ag (~20‒30 nm) nano-objects is achieved simultaneously by nanosecond-pulsed discharges in liquid nitrogen between one cadmium electrode and one silver electrode. Oxidation occurs when liquid nitrogen is fully evaporated and nanoparticles are in contact with the air. No alloy is formed, whatever the conditions, even though both elements are present simultaneously, as showed by time-resolved optical emission spectroscopy. This lack of reactivity between elements is attributed to the high pressure within the discharge that keeps each metallic vapor around the electrode it comes from. Each element exhibits a specific behavior. Cubic Cd particles, formed at 4 kV, get elongated with filamentary tips when the applied voltage reaches 7 and 10 kV. Cd wires are formed by assembly in liquid nitrogen of Cd nanoparticles driven by dipole assembly, and not by dielectrophoresis. On the contrary, silver spherical particles get assembled into 2D dendritic structures. The anisotropic growth of these structures is assumed to be due to the existence of pressure gradients.

关键词： spark discharges submerged discharges time-resolved optical emission spectroscopy liquid nitrogen

HTML PDF 收藏

Genome-resolved metagenomic analysis reveals different functional potentials of multiple Brocadia species

《环境科学与工程前沿（英文）》 2023年第17卷第1期 doi: 10.1007/s11783-023-1602-7

摘要：

● Four Ca. Brocadia species were observed during the spontaneously enrichment.

关键词： Anammox Candidatus Brocadia Functional potential Cooccurring mechanisms Swine wastewater treatment facilities

HTML PDF 收藏

Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

Xinfeng WANG, Wenxing WANG, Likun XUE, Xiaomei GAO, Wei NIE, Yangchun YU, Yang ZHOU, Lingxiao YANG, Qingzhu ZHANG, Tao WANG

《环境科学与工程前沿（英文）》 2013年第7卷第6期页码 815-826 doi: 10.1007/s11783-013-0503-6

摘要： To understand the size-resolved aerosol ionic composition and the factors influencing secondary aerosol formation in the upper boundary layer in South Central China, size-segregated aerosol samples were collected using a micro-orifice uniform deposit impactor (MOUDI) in spring 2009 at the summit of Mount Heng (1269 m asl), followed by subsequent laboratory analyses of 13 inorganic and organic water-soluble ions. During non-dust-storm periods, the average PM concentration was 41.8 μg·m , contributing to 55% of the PM . Sulfates, nitrates, and ammonium, the dominant ions in the fine particles, amounted to 46.8% of the PM . Compared with Mount Tai in the North China Plain, the concentrations of both fine and coarse particles and the ions contained therein were substantially lower. When the air masses from Southeast Asia prevailed, intensive biomass burning there led to elevated concentrations of sulfates, nitrates, ammonium, potassium, and chloride in the fine particles at Mount Heng. The air masses originating from the north Gobi brought heavy dust storms that resulted in the remarkable production of sulfates, ammonium, methane sulfonic acid, and oxalates in the coarse particles. Generally, the sulfates were primarily produced in the form of (NH ) SO in the droplet mode via heterogeneous aqueous reactions. Only approximately one-third of the nitrates were distributed in the fine mode, and high humidity facilitated the secondary formation of fine nitrates. The heterogeneous formation of coarse nitrates and ammonium on dry alkaline dust surfaces was found to be less efficient than that on the coarse particles during non-dust-storm periods.

关键词： aerosol water-soluble ions size distributions secondary formation dust storm Mount Heng

HTML PDF 收藏

Plasma-electrochemical synthesis of europium doped cerium oxide nanoparticles

Liangliang Lin, Xintong Ma, Sirui Li, Marly Wouters, Volker Hessel

《化学科学与工程前沿（英文）》 2019年第13卷第3期页码 501-510 doi: 10.1007/s11705-019-1810-7

摘要： In the present study, a plasma-electrochemical method was demonstrated for the synthesis of europium doped ceria nanoparticles. Ce(NO ) ·6H O and Eu(NO ) ·5H O were used as the starting materials and being dissolved in the distilled water as the electrolyte solution. The plasma-liquid interaction process was investigated by an optical emission spectroscopy, and the obtained products were characterized by complementary analytical methods. Results showed that crystalline cubic CeO :Eu nanoparticles were successfully obtained, with a particle size in the range from 30 to 60 nm. The crystal structure didn’t change during the calcination at a temperature from 400°C to 1000°C, with the average crystallite size being estimated to be 52 nm at 1000°C. Eu ions were shown to be effectively and uniformly doped into the CeO lattices. As a result, the obtained nanophosphors emit apparent red color under the UV irradiation, which can be easily observed by naked eye. The photoluminescence spectrum further proves the downshift behavior of the obtained products, where characteristic D → F transitions of Eu ions had been detected. Due to the simple, flexible and environmental friendly process, this plasma-electrochemical method should have great potential for the synthesis of a series of nanophosphors, especially for bio-application purpose.

关键词： plasma-electrochemical method europium doped ceria rare earth nanoparticles photoluminescence

HTML PDF 收藏

Simplistic hydrothermal synthesis approach for fabricating photoluminescent carbon dots and its potential application as an efficient sensor probe for toxic lead(II) ion detection

《化学科学与工程前沿（英文）》 2023年第17卷第5期页码 536-547 doi: 10.1007/s11705-022-2239-y

摘要： The past decade has witnessed a variety of members of the carbon family along with exposure of carbon dots due to their magnificent properties in sensing, bioimaging, catalytic applications, biomedical fields, and so on. Herein, we report the simple hydrothermal method to fabricate photoluminescent doped carbon quantum dots for the detection of noxious lead(II) ions. Lead(II) ion is very venomous for both the environment and human health for which its detection is demanded area in the research field. The as-prepared carbon dots show excellent photostability, low toxicity and significant photoluminescence properties along with good water solubility. Along with these properties, carbon dots have a quantum yield of approximately 15%. In the practical field of application, these carbon dots have been used as sensing probes for the detection of lead(II) ions with a detection limit of 60 nmol·L^–1. The fluorescence intensity of carbon dots was remarkably quenched in the presence of the lead(II) ion selectively among all the tested metal ions. Furthermore, we have studied the Stern–Volmer relationship for lead(II) quenching along with the explanation of the probable quenching mechanism. Ability of the doped carbon dots in heavy metal ions sensing in an environmental sample was demonstrated.

关键词： carbon dots fluorescence heavy metal sensing practical application photoluminescence

HTML PDF 收藏

General expression for linear and nonlinear time series models

Ren HUANG, Feiyun XU, Ruwen CHEN

《机械工程前沿（英文）》 2009年第4卷第1期页码 15-24 doi: 10.1007/s11465-009-0015-z

摘要： The typical time series models such as ARMA, AR, and MA are founded on the normality and stationarity of a system and expressed by a linear difference equation; therefore, they are strictly limited to the linear system. However, some nonlinear factors are within the practical system; thus, it is difficult to fit the model for real systems with the above models. This paper proposes a general expression for linear and nonlinear auto-regressive time series models (GNAR). With the gradient optimization method and modified AIC information criteria integrated with the prediction error, the parameter estimation and order determination are achieved. The model simulation and experiments show that the GNAR model can accurately approximate to the dynamic characteristics of the most nonlinear models applied in academics and engineering. The modeling and prediction accuracy of the GNAR model is superior to the classical time series models. The proposed GNAR model is flexible and effective.

关键词： linear and nonlinear autoregressive model system identification time series analysis

HTML PDF 收藏

Run-time system based on LinSERCANS and Soft-PLC

Cunfeng KANG, Chong WANG, Chunmin MA, Xudong HUANG, Renyuan FEI

《机械工程前沿（英文）》 2009年第4卷第2期页码 120-124 doi: 10.1007/s11465-009-0019-8

摘要： Soft-PLC with open architecture is the direction of development in industrial automation. This paper discusses the method of communication between the interface functions of LinSERCANS under RTLinux and the external library of Soft-PLC under Windows. Based on the API HOOK theory, the communication between the interface functions of LinSERCANS and the external libraries of Soft-PLC is set up and it solves the calling functions of dynamic link libraries in different operation systems. It is able to combine LinSERCANS with the Soft-PLC, and a run-time system is developed based on the interface technology of the serial real-time communication system (SERCOS) and technology of soft-PLC. This run-time system has been used in all electronic injection molding machines and works very well.

关键词： Soft-PLC run-time system LinSERCANS dynamic link libraries

HTML PDF 收藏

Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

《工程管理前沿（英文）》 2017年第4卷第3期页码 368-374 doi: 10.15302/J-FEM-2017034

摘要： This study addresses the problem of two-stage scheduling on batch and single machines with limited waiting time constraint; thus, the makespan is minimized. A mixed-integer linear programming model is proposed for this problem. Three tight lower bounds and a heuristic algorithm are developed. The worst-case performance of the proposed algorithm is discussed. A hybrid differential evolution algorithm is also developed to improve the solution quantity. Numerical results show that the hybrid algorithm is capable of obtaining high-quality solutions and exhibits a competitive performance

关键词： batch machine flow shop makespan limited waiting time

HTML PDF 收藏

Analyzing construction safety through time series methods

Houchen CAO, Yang Miang GOH

《工程管理前沿（英文）》 2019年第6卷第2期页码 262-274 doi: 10.1007/s42524-019-0015-6

摘要： The construction industry produces a large amount of data on a daily basis. However, existing data sets have not been fully exploited in analyzing the safety factors of construction projects. Thus, this work describes how temporal analysis techniques can be applied to improve the safety management of construction data. Various time series (TS) methods were adopted for identifying the leading indicators or predictors of construction accidents. The data set used herein was obtained from a large construction company that is based in Singapore and contains safety inspection scores, accident cases, and project-related data collected from 2008 to 2015. Five projects with complete and sufficient data for temporal analysis were selected from the data set. The filtered data set contained 23 potential leading indicators (predictors or input variables) of accidents (output or dependent variable). TS analyses were used to identify suitable accident predictors for each of the five projects. Subsequently, the selected input variables were used to develop three different TS models for predicting accident occurrences, and the vector error correction model was found to be the best model. It had the lowest root mean squared error value for three of the five projects analyzed. This study provides insights into how construction companies can utilize TS data analysis to identify projects with high risk of accidents.

关键词： time series temporal construction safety leading indicators accident prevention forecasting

HTML PDF 收藏

Convergence to real-time decision making

James M. TIEN

《工程管理前沿（英文）》 2020年第7卷第2期页码 204-222 doi: 10.1007/s42524-019-0040-5

摘要： Real-time decision making reflects the convergence of several digital technologies, including those concerned with the promulgation of artificial intelligence and other advanced technologies that underpin real-time actions. More specifically, real-time decision making can be depicted in terms of three converging dimensions: Internet of Things, decision making, and real-time. The Internet of Things include tangible goods, intangible services, ServGoods, and connected ServGoods. Decision making includes model-based analytics (since before 1990), information-based Big Data (since 1990), and training-based artificial intelligence (since 2000), and it is bolstered by the evolving real-time technologies of sensing (i.e., capturing streaming data), processing (i.e., applying real-time analytics), reacting (i.e., making decisions in real-time), and learning (i.e., employing deep neural networks). Real-time includes mobile networks, autonomous vehicles, and artificial general intelligence. Central to decision making, especially real-time decision making, is the ServGood concept, which the author introduced in an earlier paper (2012). It is a physical product or good encased by a services layer that renders the good more adaptable and smarter for a specific purpose or use. Addition of another communication sensors layer could further enhance its smartness and adaptiveness. Such connected ServGoods constitute a solid foundation for the advanced products of tomorrow which can further display their growing intelligence through real-time decisions.

关键词： real-time decision making services goods ServGoods Big Data Internet of Things artificial intelligence wireless communications

HTML PDF 收藏

Damage identification in connections of moment frames using time domain responses and an optimization

《结构与土木工程前沿（英文）》 2021年第15卷第4期页码 851-866 doi: 10.1007/s11709-021-0739-3

摘要： Damage is defined as changes to the material and/or geometric properties of a structural system, comprising changes to the boundary conditions and system connectivity, adversely affecting the system’s performance. Inspecting the elements of structures, particularly critical components, is vital to evaluate the structural lifespan and safety. In this study, an optimization-based method for joint damage identification of moment frames using the time-domain responses is introduced. The beam-to-column connection in a metallic moment frame structure is modeled by a zero-length rotational spring at both ends of the beam element. For each connection, an end-fixity factor is specified, which changes between 0 and 1. Then, the problem of joint damage identification is converted to a standard optimization problem. An objective function is defined using the nodal point accelerations extracted from the damaged structure and an analytical model of the structure in which the nodal accelerations are obtained using the Newmark procedure. The optimization problem is solved by an improved differential evolution algorithm (IDEA) for identifying the location and severity of the damage. To assess the capability of the proposed method, two numerical examples via different damage scenarios are considered. Then, a comparison between the proposed method and the existing damage identification method is provided. The outcomes reveal the high efficiency of the proposed method for finding the severity and location of joint damage considering noise effects.

关键词： damage identification beam-to-column connection time-domain response optimization

HTML PDF 收藏

origins of schedule management: the concepts used in planning, allocating, visualizing and managing time

Lynda M. BOURNE, Patrick WEAVER

《工程管理前沿（英文）》 2018年第5卷第2期页码 150-166 doi: 10.15302/J-FEM-2018012

摘要： Getting the in the at the has always been a major organizational challenge. In ancient times this process seems to have been accomplished based on the scheme of arrangements being contained in the leader’s mind and instructions communicated verbally. Modern approaches to solving the twin challenges of first thinking through the ‘plan’ and then communicating the plan to the people who need to do ‘ ’ use sophisticated graphics, charts, diagrams, and computations. This paper traces the development of the concepts most project managers take for granted including bar charts and critical path schedules from their origins (which are far earlier than most people think) through to the modern day. The first section of the paper looks at the development of concepts that allow the visualization of time and other data. The second looks at the shift from static representations to dynamic modeling through the emergence of computers, dynamic calculations and integrated data from the 1950s to the present time.

关键词： time management scheduling CPM PERT Gantt Critical Path bar chart

HTML PDF 收藏

Sustainability of steel structures: towards an integrated approach to life-time engineering design

Raffaele LANDOLFO, Lucrezia CASCINI, Francesco PORTIOLI

《结构与土木工程前沿（英文）》 2011年第5卷第3期页码 304-314 doi: 10.1007/s01709-011-0123-9

摘要： Nowadays, the construction sector is more and more oriented toward the promotion of sustainability in all its activities. The goal to achieve is the optimization of performances, over the whole life-cycle, with respect to environmental, economic and social requirements. According to the latest advances, the concept of sustainability applied to constructions covers a number of branches such as life-cycle costing, ecology, durability and even structural design. Several procedures and design tools have been implemented in the framework of international research. Indeed the current trend in civil engineering research is moving towards life-time engineering, with the aim to implement integrated methodologies to consider as a whole all the sustainability requirements according to time-dependent multi-performance-based design approaches. Following a general introduction of the concept of sustainability applied to constructions, this paper presents an overview of life-time engineering methodologies according to the current state-of-the-art. In particular the methods currently received by International Standards are discussed. A special focus is devoted to the durability design of metal structures with respect to the degradation phenomena able to impair the structural capacity over time. Finally a proposal towards an integrated approach to life-time engineering design of steel structures and needs for further advances are presented.

关键词： sustainability life-time engineering performance based design durability metal structures

HTML PDF 收藏

标题作者时间类型操作

Long-lasting photoluminescence quantum yield of cesium lead halide perovskite-type quantum dots

Yonghyun Kim, Huiwen Liu, Yi Liu, Boa Jin, Hao Zhang, Wenjing Tian, Chan Im

期刊论文

Engineering

Raquel Portela, Susana Perez-Ferreras, Ana Serrano-Lotina, Miguel A. Bañares

期刊论文

Synthesis of Ag and Cd nanoparticles by nanosecond pulsed discharge in liquid nitrogen

Mahmoud Trad, Alexandre Nominé, Natalie Tarasenka, Jaafar Ghanbaja, Cédric Noël, Malek Tabbal, Thierry Belmonte

期刊论文

Genome-resolved metagenomic analysis reveals different functional potentials of multiple Brocadia species

期刊论文

Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

Xinfeng WANG, Wenxing WANG, Likun XUE, Xiaomei GAO, Wei NIE, Yangchun YU, Yang ZHOU, Lingxiao YANG, Qingzhu ZHANG, Tao WANG

期刊论文

Plasma-electrochemical synthesis of europium doped cerium oxide nanoparticles

Liangliang Lin, Xintong Ma, Sirui Li, Marly Wouters, Volker Hessel

期刊论文

Simplistic hydrothermal synthesis approach for fabricating photoluminescent carbon dots and its potential application as an efficient sensor probe for toxic lead(II) ion detection

期刊论文

General expression for linear and nonlinear time series models

Ren HUANG, Feiyun XU, Ruwen CHEN

期刊论文

Run-time system based on LinSERCANS and Soft-PLC

Cunfeng KANG, Chong WANG, Chunmin MA, Xudong HUANG, Renyuan FEI

期刊论文

Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

期刊论文

Analyzing construction safety through time series methods

Houchen CAO, Yang Miang GOH