资源类型

期刊论文 273

年份

2023 26

2022 23

2021 24

2020 15

2019 13

2018 18

2017 10

2016 11

2015 9

2014 5

2013 12

2012 15

2011 14

2010 15

2009 11

2008 15

2007 14

2006 5

2005 4

2004 1

展开 ︾

关键词

催化剂 2

反应模型 2

热力学 2

状态监测 2

&alpha 1

Al-Cr203体系 1

COVID-19 1

DNA计算 1

PCR核酸检测 1

Pd局域环境 1

RELAP5 1

sn-2棕榈酸甘油酯 1

一维（1D） 1

三峡船闸；输水方式；水流条件；通过能力 1

三相界面 1

不利荷载 1

两个反应区 1

中子测量 1

中美对比 1

展开 ︾

检索范围：

排序： 展示方式：

Ethanol production from sweet sorghum residual

BAN Jingyang, YU Jianliang, ZHANG Xu, TAN Tianwei

《化学科学与工程前沿（英文）》 2008年 第2卷 第4期   页码 452-455 doi: 10.1007/s11705-008-0072-6

摘要： In this work, the ethanol production from sweet sorghum residue was studied. Sweet sorghum residue was hydrolyzed with phosphoric acid under mild conditions. The liquid hydrolysate was fermented by , and the hydrolysis residue was fermented by the simultaneous saccharification and fermentation (SSF) using with cellulase (60 FPU/g dry materials). Orthogonal experiments were carried out to investigate the effects of main reaction condition factors, such as temperature, acid concentration, time and dry-matter content, on the reducing sugar yield. The results show that the optimal reaction conditions should be 120°C, 80 g/L, 80 min and 10%, respectively. Under these conditions, 0.3024 g reducing sugar/g dry material was obtained. The liquid hydrolysate was then fermented by with the highest ethanol concentration of 14.5 g/L. At a water-insoluble solid concentration of 5%, 5.4 g/L ethanol was obtained after 12 h of SSF. The total ethanol yield was 0.147 g/g dry material, which would be beneficial for the application of ethanol production from sweet sorghum residue.

关键词： application     material     optimal reaction     reaction condition     temperature    

HTML PDF 收藏

A review of condition-based maintenance: Its prognostic and operational aspects

Yanrong LI, Shizhe PENG, Yanting LI, Wei JIANG

《工程管理前沿（英文）》 2020年 第7卷 第3期   页码 323-334 doi: 10.1007/s42524-020-0121-5

摘要： Condition-based maintenance (CBM) detects early signs of failure and dictates when maintenance should be performed based on the actual condition of a system. In this paper, we first review some of the recent research on CBM under various physical structures and signal data. Then, we summarize several kinds of prognostic models that use monitoring information to estimate the reliability of complex systems or products. Monitoring information also facilitates operational decisions in production planning, spare parts management, reliability improvement, and prognostics and health management. Finally, we suggest some research opportunities for the reliability and operations management communities to fill the research gap between these two fields.

关键词： condition-based maintenance     prognostics     operational decision-making     reliability    

HTML PDF 收藏

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 171-175 doi: 10.1007/s11465-009-0091-0

摘要： Trend prediction technology is the key technology to achieve condition-based maintenance of mechanical equipment. Large-sized water injection units are key equipment in oilfields. The traditional preventive maintenance is not economical and cannot completely avoid vicious accidents. To ensure the normal operation of units and save maintenance costs, trend prediction technology is studied to achieve condition-based maintenance for water injection units. The main methods of the technology are given, the trend prediction method based on neural network is put forward, and the expert system based on the knowledge is developed. The industrial site verification shows that the proposed trend prediction technology can reflect the operating condition trend change of the water injection units and provide technical means to achieve condition-based predictive maintenance.

关键词： water injection units     condition-based maintenance     trend prediction    

HTML PDF 收藏

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

《机械工程前沿（英文）》 doi: 10.1007/s11465-021-0661-3

摘要： Tool failures in machining processes often cause severe damages of workpieces and lead to large quantities of loss, making tool condition monitoring an important, urgent issue. However, problems such as practicability still remain in actual machining. Here, a real-time tool condition monitoring method integrated in an in situ fiber optic temperature measuring apparatus is proposed. A thermal simulation is conducted to investigate how the fluctuating cutting heats affect the measuring temperatures, and an intermittent cutting experiment is carried out, verifying that the apparatus can capture the rapid but slight temperature undulations. Fourier transform is carried out. The spectrum features are then selected and input into the artificial neural network for classification, and a caution is given if the tool is worn. A learning rate adaption algorithm is introduced, greatly reducing the dependence on initial parameters, making training convenient and flexible. The accuracy stays 90% and higher in variable argument processes. Furthermore, an application program with a graphical user interface is constructed to present real-time results, confirming the practicality.

关键词： tool condition monitoring     cutting temperature     neural network     learning rate adaption    

HTML PDF 收藏

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Amin Mohammad Mehdi,Bina Bijan,Majd Amir Masoud Samani,Pourzamani Hamidreza

《环境科学与工程前沿（英文）》 2014年 第8卷 第3期   页码 345-356 doi: 10.1007/s11783-013-0574-4

摘要： Benzene removal from aqueous solutions was evaluated using Fe O nano magnetic particles (NM) in continuous condition. A 4 factorial design including initial benzene concentration, NM dose, contact time and pH was investigated in 16 experiments (Taguchi OA design). The results indicated that all factors were significant and the optimum condition was: pH 8, NM dose of 2000 mg·L , benzene concentrations of 100 mg·L and contact time of 14 min. The maximum benzene uptake and distribution ratio in the optimum situation were 49.4 mg·g and 38.4 L·g , respectively. The nano particles were shown to capture 98.7% of the benzene in optimum batch condition and 94.5% in continuous condition. The isotherm data proved that the Brunauer-Emmett-Teller model fit more closely and produced an isotherm constant (b) less than one, indicating favorable adsorption. Regeneration studies verified that the benzene adsorbed by the NM could be easily desorbed by temperature, and thereby, NM can be employed repeatedly in water and wastewater management.

关键词： benzene     experimental design     Fe3O4     continues condition     thermal recycling    

HTML PDF 收藏

In-situ condition monitoring of reinforced concrete structures

Sanjeev Kumar VERMA,Sudhir Singh BHADAURIA,Saleem AKHTAR

《结构与土木工程前沿（英文）》 2016年 第10卷 第4期   页码 420-437 doi: 10.1007/s11709-016-0336-z

摘要： Performance of concrete structures is significantly influenced and governed by its durability and resistance to environmental or exposure conditions, apart from its physical strength. It can be monitored, evaluated and predicted through modeling of physical deterioration mechanisms, performance characteristics and parameters and condition monitoring of in situ concrete structures. One such study has been conducted using Non-destructive testing equipment in the city of Bhopal and around located in India. Some selected parameters influencing durability of reinforced concrete (RC) structures such as concrete cover, carbonation depth, chloride concentration, half cell potential and compressive strength have been measured, for establishing correlation among various parameters and age of structures. Effects of concrete cover and compressive strength over the variation of chloride content with time are also investigated.

关键词： concrete     carbonation     chloride     corrosion     monitoring     models    

HTML PDF 收藏

Distributed flexible reconfigurable condition monitoring and diagnosis technology

HU You-min, YANG Shu-zi, DU Run-sheng

《机械工程前沿（英文）》 2006年 第1卷 第3期   页码 276-281 doi: 10.1007/s11465-006-0025-z

摘要： As manufacturing becomes increasingly decentralized, flexible and reconfigurable, more research needs to be done on monitoring and diagnosis technology that accommodate these new trends. The distributed condition monitoring and diagnosis technology based on the flexible and reconfigurable concept is studied here. A condition monitoring diagnosis model based on the distributed flexible and reconfigurable idea is proposed in this paper. The component makeup and functions of this model are discussed in detail. The model can fulfill in most instances the manufacturing system requirements for changing the configuration of the monitoring diagnosis system according to different manufacturing system configurations. This model also realizes the flexibility and reconfigurability of the monitoring diagnosis system in some degree. The model has already spawned a successful prototype for monitoring a chemical plant in accomplishing monitoring and control of the production process and equipment. Finally, some future research work is pointed out.

关键词： chemical     diagnosis system     configuration     monitoring     equipment    

HTML PDF 收藏

Comprehensive health condition assessment on partial sewers in a southern Chinese city based on fuzzy

Lili GAN, Jiane ZUO, Yajiao WANG, Thong Soon LOW, Kaijun WANG

《环境科学与工程前沿（英文）》 2014年 第8卷 第1期   页码 144-150 doi: 10.1007/s11783-013-0554-8

摘要： A self-developed sewer health assessment system using the fuzzy comprehensive evaluation and analytical hierarchy process was applied to give a comprehensive health condition evaluation on part of the local sewers in a southern Chinese city based on the sewer video data collected by a sewer inspection closed circuit television (CCTV) robot. Aside from the overall condition evaluation, the structure, function, and stability status of the sewer were also analyzed using the method. A comprehensive index was proposed to give the overall health condition of pipes with different defects, and , , and were used to quantify the defects affecting the tightness, stability, and function of the pipe, respectively. Results show that 48% of the inspected pipes were in good condition (0< <0.25), and about 33% of the sewer pipes analyzed were categorized to be at severe or urgent condition levels ( >0.5), although most of the pipes were installed only within five years. Frequent sedimentation affects the function of the sewer, and deformation and joint damage affect the structure of the sewer.

关键词： sewer     health condition assessment     analytical hierarchy process     fuzzy comprehensive evaluation     fuzzy mathematic method    

HTML PDF 收藏

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1700-1712 doi: 10.1007/s11705-022-2207-6

摘要： The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of naphtha. Herein, for a better catalyst design and operation parameters optimization, the reaction pathways and equilibrium yields for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins were analyzed thermodynamically. The results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways, respectively. However, the formation of light paraffin severely limits the maximum selectivity toward light olefins. The dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light olefins. The results are thus useful as a direction for future catalyst improvements, facilitating superior reaction pathways to enhance light olefins. In addition, the equilibrium yield of light olefins increased with increasing the chain length, and the introduction of cyclo-paraffin inhibits the formation of light olefins. High temperatures and low pressures favor the formation of ethylene, and moderate temperatures and low pressures favor the formation of propylene. n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90% and 55.77%, respectively. This work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C5–8 n/iso/cyclo-paraffins from a thermodynamic point of view.

关键词： naphtha     catalytic pyrolysis     reaction pathway     equilibrium yield    

HTML PDF 收藏

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

《机械工程前沿（英文）》 2006年 第1卷 第1期   页码 90-95 doi: 10.1007/s11465-005-0006-7

摘要：

To exactly describe the contact state and contact area of tooth surface of toroidal involute (TI) worm gearing, the authors introduced boundary condition into contact line analysis.With helix angle chosen as parameter, the criterion for the existence of meshing boundary line on the surface of TI worm gearing is derived. Results show that there can be four situations for meshing boundary line on the tooth surface of gear, namely, inexistence of meshing boundary line, a unique line, two lines, and two coincident lines. If the helix angle is equal to or slightly smaller than the bigger angle, which makes two meshing boundary lines superpose, a preferable meshing performance is obtained. Computer simulation proves the validity of the above conclusion.

关键词： preferable     inexistence     Results     validity     boundary condition    

HTML PDF 收藏

Frontier of continuous structural health monitoring system for short & medium span bridges and condition

Ayaho MIYAMOTO, Risto KIVILUOMA, Akito YABE

《结构与土木工程前沿（英文）》 2019年 第13卷 第3期   页码 569-604 doi: 10.1007/s11709-018-0498-y

摘要： It is becoming an important social problem to make maintenance and rehabilitation of existing short and medium span(10-20 m) bridges because there are a huge amount of short and medium span bridges in service in the world. The kernel of such bridge management is to develop a method of safety(condition) assessment on items which include remaining life and load carrying capacity. Bridge health monitoring using information technology and sensors is capable of providing more accurate knowledge of bridge performance than traditional strategies. The aim of this paper is to introduce a state-of-the-art on not only a rational bridge health monitoring system incorporating with the information and communication technologies for lifetime management of existing short and medium span bridges but also a continuous data collecting system designed for bridge health monitoring of mainly short and medium span bridges. In this paper, although there are some useful monitoring methods for short and medium span bridges based on the qualitative or quantitative information, mainly two advanced structural health monitoring systems are described to review and analyse the potential of utilizing the long term health monitoring in safety assessment and management issues for short and medium span bridge. The first is a special designed mobile loading device(vehicle) for short and medium span road bridges to assess the structural safety(performance) and derive optimal strategies for maintenance using reliability based method. The second is a long term health monitoring method by using the public buses as part of a public transit system (called bus monitoring system) to be applied mainly to short and medium span bridges, along with safety indices, namely, “characteristic deflection” which is relatively free from the influence of dynamic disturbances due to such factors as the roughness of the road surface, and a structural anomaly parameter.

关键词： condition assessment     short & medium span bridge     structural health monitoring(SHM)     long-term data collection     system     maintenance     bridge performance     information technology     loading vehicle(public bus)     in-situ loading    

HTML PDF 收藏

Condition monitoring of a wind turbine generator using a standalone wind turbine emulator

Himani,Ratna DAHIYA

《能源前沿（英文）》 2016年 第10卷 第3期   页码 286-297 doi: 10.1007/s11708-016-0419-5

摘要： The intend of this paper is to give a description of the realization of a low-cost wind turbine emulator(WTE) with open source technology from graze required for the condition monitoring to diagnose rotor and stator faults in a wind turbine generator (WTG). The WTE comprises of a 2.5 kW DC motor coupled with a 1 kW squirrel-cage induction machine. This paper provides a detailed overview of the hardware and software used along with the WTE control strategies such as MPPT and pitch control. The emulator reproduces dynamic characteristics both under step variations and arbitrary variation in the wind speed of a typical wind turbine (WT) of a wind energy conversion system (WECS). The usefulness of the setup has been benchmarked with previously verified WT test rigs made at the University of Manchester and Durham University in UK. Considering the fact that the rotor blades and electric subassemblies direct drive WTs are most susceptible to damage in practice, generator winding faults and rotor unbalance have been introduced and investigated using the terminal voltage and generated current. This wind turbine emulator (WTE) can be reconfigured or analyzed for condition monitoring without the need for real WTs.

关键词： condition monitoring (CM)     wind turbine emulator (WTE)     wind turbine generator (WTG)     maximum power point tracking (MPPT)     tip speed ratio (TSR)     rotor faults     stator faults    

HTML PDF 收藏

Special issue: Wind turbine dynamic modeling, condition monitoring and diagnosis

Zheng YOU, Jinji GAO, Fulei CHU, Tielin SHI

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 279-280 doi: 10.1007/s11465-017-0476-4

HTML PDF 收藏

民航视情维修决策优化模型发展

张海军,左洪福,梁剑,戎翔

《中国工程科学》 2005年 第7卷 第11期   页码 17-20

摘要：

目前视情维修是民航业采用的主要维修方式，可以使维修的有效性、经济性大幅度提高。维修决策优化模型对民航维修成本的降低和利润的提升具有显著的指导作用；归纳了视情维修的时间延迟模型、冲击模型、比例危险模型、马尔可夫决策模型等优化模型的建模方法；分析了该类模型在应用中存在的不足，并展望了其发展前景。

关键词： 视情维修     优化模型     决策     成本    

HTML PDF 收藏

Study and practice on condition-based maintenance of induced fans in coal-fired power plants

CHEN Gang, LI Bing, CHEN Fei, HUANG Shuhong

《能源前沿（英文）》 2008年 第2卷 第2期   页码 211-215 doi: 10.1007/s11708-008-0028-z

摘要： Reducing the enormous maintenance cost is essential to enhance the competitiveness for power plants. An overall design scheme for condition-based maintenance of induced fans is proposed for large thermal power plants. The interface of the above framework is simple and convenient; the optimum maintenance strategy is given by condition monitoring and risk evaluating. The decision-supported system was used in Guangdong Shajiao C Power Plant. The results show that it is a feasible maintenance optimization scheme for power plants.
HTML PDF 收藏

标题 作者 时间 类型 操作

Ethanol production from sweet sorghum residual

BAN Jingyang, YU Jianliang, ZHANG Xu, TAN Tianwei

期刊论文

A review of condition-based maintenance: Its prognostic and operational aspects

Yanrong LI, Shizhe PENG, Yanting LI, Wei JIANG

期刊论文

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

期刊论文

Real-time tool condition monitoring method based on temperature measurement and artificial neural network

期刊论文

Benzene removal by nano magnetic particles under continuous condition from aqueous solutions

Amin Mohammad Mehdi,Bina Bijan,Majd Amir Masoud Samani,Pourzamani Hamidreza

期刊论文

In-situ condition monitoring of reinforced concrete structures

Sanjeev Kumar VERMA,Sudhir Singh BHADAURIA,Saleem AKHTAR

期刊论文

Distributed flexible reconfigurable condition monitoring and diagnosis technology

HU You-min, YANG Shu-zi, DU Run-sheng

期刊论文

Comprehensive health condition assessment on partial sewers in a southern Chinese city based on fuzzy

Lili GAN, Jiane ZUO, Yajiao WANG, Thong Soon LOW, Kaijun WANG

期刊论文

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

期刊论文

Effects of Boundary Condition and Helix Angle on Meshing Performance of TI Worm Gearing

SUN Yue-hai, DUAN Lu-qian, WANG Shu-ren, ZHANG Ce

期刊论文

Frontier of continuous structural health monitoring system for short & medium span bridges and condition

Ayaho MIYAMOTO, Risto KIVILUOMA, Akito YABE

期刊论文

Condition monitoring of a wind turbine generator using a standalone wind turbine emulator

Himani,Ratna DAHIYA

期刊论文

Special issue: Wind turbine dynamic modeling, condition monitoring and diagnosis

Zheng YOU, Jinji GAO, Fulei CHU, Tielin SHI

期刊论文

民航视情维修决策优化模型发展

张海军,左洪福,梁剑,戎翔

期刊论文

Study and practice on condition-based maintenance of induced fans in coal-fired power plants

CHEN Gang, LI Bing, CHEN Fei, HUANG Shuhong

期刊论文