资源类型

期刊论文 645

年份

2023 39

2022 48

2021 50

2020 58

2019 30

2018 34

2017 37

2016 35

2015 27

2014 25

2013 19

2012 32

2011 21

2010 30

2009 32

2008 37

2007 36

2006 8

2005 9

2004 6

展开 ︾

关键词

动力特性 4

临床特征 3

2035 2

中国 2

中国特色 2

乳液 2

内禀尺度 2

双层辉光离子渗金属 2

发展趋势 2

吸附 2

无氢渗碳 2

有限元 2

模型试验 2

海上风电场 2

混凝土 2

细水雾 2

&alpha 1

6G 1

Al@AP/PVDF纳米复合材料 1

展开 ︾

检索范围:

排序: 展示方式:

Surface modification techniques of membranes to improve their antifouling characteristics: recent advancements

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1837-1865 doi: 10.1007/s11705-023-2347-3

摘要: Surface modification techniques of membranes to improve their antifouling characteristics: recent advancements and developments

关键词: Surface modification techniques    

Performance and emission characteristics of a diesel engine operating on different water in diesel emulsionfuels: optimization using response surface methodology (RSM)

Seyed Saeed HOSEINI, Mohammad Amin SOBATI

《能源前沿(英文)》 2019年 第13卷 第4期   页码 636-657 doi: 10.1007/s11708-019-0646-7

摘要: The nitrogen oxide (NO ) release of diesel engines can be reduced using water in diesel emulsion fuel without any engine modification. In the present paper, different formulations of water in diesel emulsion fuels were prepared by ultrasonic irradiation. The water droplet size in the emulsion, polydisperisty index, and the stability of prepared fuel was examined, experimentally. Afterwards, the performance characteristics and exhaust emission of a single cylinder air-cooled diesel engine were investigated using different water in diesel emulsion fuels. The effect of water content (in the range of 5%–10% by volume), surfactant content (in the range of 0.5%–2% by volume), and hydrophilic-lipophilic balance (HLB) (in the range of 5–8) was examined using Box-Behnken design (BBD) as a subset of response surface methodology (RSM). Considering multi-objective optimization, the best formulation for the emulsion fuel was found to be 5% water, 2% surfactant, and HLB of 6.8. A comparison was made between the best emulsion fuel and the neat diesel fuel for engine performance and emission characteristics. A considerable decrease in the nitrogen oxide emission (–18.24%) was observed for the best emulsion fuel compared to neat diesel fuel.

关键词: water in diesel emulsion fuel     hydrophilic-lipophilic balance (HLB)     response surface methodology (RSM)     emulsion stability     engine performance     exhaust emission    

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0730-2

摘要: Ultrasonic vibration-assisted grinding (UVAG) is an advanced hybrid process for the precision machining of difficult-to-cut materials. The resonator is a critical part of the UVAG system. Its performance considerably influences the vibration amplitude and resonant frequency. In this work, a novel perforated ultrasonic vibration platform resonator was developed for UVAG. The holes were evenly arranged at the top and side surfaces of the vibration platform to improve the vibration characteristics. A modified apparent elasticity method (AEM) was proposed to reveal the influence of holes on the vibration mode. The performance of the vibration platform was evaluated by the vibration tests and UVAG experiments of particulate-reinforced titanium matrix composites. Results indicate that the reasonable distribution of holes helps improve the resonant frequency and vibration mode. The modified AEM, the finite element method, and the vibration tests show a high degree of consistency for developing the perforated ultrasonic vibration platform with a maximum frequency error of 3%. The employment of ultrasonic vibration reduces the grinding force by 36% at most, thereby decreasing the machined surface defects, such as voids, cracks, and burnout.

关键词: ultrasonic vibration-assisted grinding     perforated ultrasonic vibration platform     vibration characteristics     apparent elasticity method     grinding force     surface integrity    

Activity and characteristics of “Oxygen-enriched” highly reactive absorbent for simultaneous flue gas

Yi ZHAO,Tianxiang GUO,Zili ZANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 222-229 doi: 10.1007/s11783-014-0636-2

摘要: An “Oxygen-enriched” highly reactive absorbent was prepared by mixing fly ash, lime and a small quantity of KMnO for simultaneous desulfurization and denitrification. Removal of SO and NO simultaneously was carried out using this absorbent in a flue gas circulating fluidized bed (CFB). The highest simultaneous removal efficiency, 94.5% of SO and 64.2% of NO, was achieved under the optimal experiment conditions. Scanning Electron Microscope (SEM) and Accessory X-ray Energy Spectrometer (EDX) were used to observe the surface characteristics of fly ash, lime, “Oxygen-enriched” highly reactive absorbent and the spent absorbent. An ion chromatograph (IC) and chemical analysis methods were used to determine the contents of sulfate, sulfite, nitrate and nitrite in the spent absorbents, the results showed that sulfate and nitrite were the main products for desulfurization and denitrification respectively. The mechanism of removing SO and NO simultaneously was proposed based on the analysis results of SEM, EDX, IC and the chemical analysis methods.

关键词: “Oxygen-enriched” highly reactive absorbent     Surface characteristics     Flue gas circulating fluidized bed     Simultaneous desulfurization and denitrification    

Characteristics and application of road absorbing solar energy

Zhihua ZHOU, Shan HU, Xiaoyan ZHANG, Jian ZUO

《能源前沿(英文)》 2013年 第7卷 第4期   页码 525-534 doi: 10.1007/s11708-013-0278-2

摘要: If the heat of road surface can be stored in summer, the road surface temperature will be decreased to prevent permanent deformation of pavement. Besides, if the heat stored is released, it can supply heat for buildings or raise the road surface temperature for snow melting in winter. A road-solar energy system was built in this study, and the heat transfer mechanism and effect of the system were analyzed according to the monitored solar radiant heat, the solar energy absorbed by road and the heat stored by soil. The results showed that the road surface temperature was mainly affected by solar radiation, but the effect is hysteretic in nature. The temperature of the solar road surface was 3°C–6°C lower than that of the ordinary road surface. The temperature of the solar road along the vertical direction was 2°C–5°C lower than that of the ordinary road. The temperature difference increased as the distance to the heat transfer tubes decreased. The average solar collector efficiency of the system was 14.4%, and the average solar absorptivity of road surface was 36%.

关键词: solar energy     road-solar energy system     road surface temperature     solar absorptivity of road surface     solar collector efficiency of system    

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0672-8

摘要: Surface roughness and thermal action are of remarkable importance in the lubrication performance of mechanical components, especially in extreme conditions. However, available studies mainly focus on the full-film lubrication conditions without considering temperature rise and real 3D surface roughness due to the complexity of surface topography and temperature characteristics. Moreover, studies on the interfacial thermal behaviors of 3D rough surface lubricated contact in an extended range of working conditions remain limited. In this paper, a deterministic mixed thermal elastohydrodynamic lubrication model considering real 3D surface roughness and thermal effects is proposed. In this model, pressure and temperature are coupled with each other, the computation of elastic deformation is accelerated through the discrete convolution and fast Fourier transform method, the temperature field is calculated with the column sweeping technique, and the semi-system method is introduced to improve convergence and numerical stability under severe conditions. The model is validated by comparing its results with available published numerical and experimental results. The thermal behaviors of the contact interface are studied in a wide range of working conditions. The influences of surface roughness and thermal effect on lubrication performance are revealed. The results show that the proposed model can be used as a powerful analysis tool for lubrication performance and temperature prediction in various heavy-load, high-speed lubricated components over a wide range of lubrication conditions.

关键词: thermal elastohydrodynamic lubrication     surface roughness effect     thermal effect     temperature characteristics     severe conditions    

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded

Mohammadreza SHABGARD, Hamed KAKOLVAND, Mirsadegh SEYEDZAVVAR, Ramin Mohammadpour SHOTORBANI

《机械工程前沿(英文)》 2011年 第6卷 第4期   页码 419-428 doi: 10.1007/s11465-011-0246-7

摘要:

This paper presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of ultrasonic vibration of workpiece on the characteristics of Electrical Discharge Machining (EDM) process of FW4 Welding Metal in comparison with the conventional EDM process. The studied process characteristics included the material removal rate (MRR), tool wear ratio (TWR), and surface roughness (Ra and Rmax) of the workpiece after the EDM and ultrasonic assisted EDM (US-EDM) processes. The experiments performed under the designed full factorial procedure and the considered EDM input parameters included pulse on-time and pulse current. The experimental results show that in short pulse on-times, material removal rate in the US-EDM process is approximately quadruple than that of the EDM process. On the contrary, in the long pulse on-times, ultrasonic vibration of work??piece leads to the reduction in the MRR. On the other hand, in short pulse on-times, the TWR in the US-EDM process is lower than that of in the EDM process, and this condition reverses with increase in the pulse on-time. Furthermore, the surface roughness of the workpiece machined by EDM process is slightly lower than that of applied to the US-EDM process.

关键词: electrical discharge machining (EDM)     material removal rate (MRR)     tool wear ratio (TWR)     surface roughness    

Optimization of WEDM process of pure titanium with multiple performance characteristics using Taguchi

Rupesh CHALISGAONKAR, Jatinder KUMAR

《机械工程前沿(英文)》 2013年 第8卷 第2期   页码 201-214 doi: 10.1007/s11465-013-0256-8

摘要:

This paper describes the development of multi response optimization technique using utility method to predict and select the optimal setting of machining parameters in wire electro-discharge machining (WEDM) process. The experimental studies in WEDM process were conducted under varying experimental conditions of process parameters, such as pulse on time(Ton), pulse off time(Toff), peak current (IP), wire feed (WF), wire tension (WT) and servo voltage (SV) using pure titanium as work material. Experiments were planned using Taguchi’s L27 orthogonal array. Multi response optimization was performed for both cutting speed (CS) and surface roughness (SR) using utility concept to find out the optimal process parameter setting. The level of significance of the machining parameters for their effect on the CS and SR was determined by using analysis of variance (ANOVA). Finally, confirmation experiment was performed to validate the effectiveness of the proposed optimal condition.

关键词: wire electro-discharge machining (WEDM)     Taguchi method     analysis of variance (ANOVA)     utility concept     cutting speed (CS)     surface roughness (SR)    

Enhanced dewatering characteristics of waste activated sludge with Fenton pretreatment: effectiveness

Guangyin ZHEN, Xueqin LU, Baoying WANG, Youcai ZHAO, Xiaoli CHAI, Dongjie NIU, Tiantao ZHAO

《环境科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 267-276 doi: 10.1007/s11783-013-0530-3

摘要: In this work, the enhanced dewaterabing characteristics of waste activated sludge using Fenton pretreatment was investigated in terms of effectiveness and statistical optimization. Response surface method (RSM) and central composite design (CCD) were applied to evaluate and optimize the effectiveness of important operational parameters, i.e., H O concentrations, Fe concentrations and initial pH values. A significant quadratic polynomial model was obtained ( 0.9189) with capillary suction time (CST) reduction efficiency as the response. Numerical optimization based on desirability function was carried out. The optimum values for H O , Fe , and initial pH were found to be 178 mg·g VSS (volatile suspended solids), 211 mg·g VSS and 3.8, respectively, at which CST reduction efficiency of 98.25% could be achieved. This complied well with those predicted by the established polynomial model. The results indicate that Fenton pretreatment is an effective technique for advanced waste activated sludge dewatering. The enhancement of sludge dewaterability by Fenton’s reagent lies in the migration of sludge bound water due to the disintegration of sludge flocs and microbial cells lysis.

关键词: Fenton pretreatment     response surface methodology (RSM)     capillary suction time (CST)     dewaterabilty     molecular weight distribution    

Upgrading pyrolytic carbon-blacks (CBp) from end-of-life tires: Characteristics and modification methodologies

Jiaxue Yu, Junqing Xu, Zhenchen Li, Wenzhi He, Juwen Huang, Junshi Xu, Guangming Li

《环境科学与工程前沿(英文)》 2020年 第14卷 第2期 doi: 10.1007/s11783-019-1198-0

摘要: Modification methodologies of upgrading CBp from ELTs were reviewed. Surface microstructures and physiochemical properties of CBp were analyzed. Future perspectives of ELTs pyrolysis industries were suggested. Over 1 billion end-of-life tires (ELTs) are generating annually, and 4 billion ELTs are currently abandoned in landfills and stockpiles worldwide, according to the statistics, leading to the environmental and health risks. To circumvent these issues, pyrolysis, as an attractive thermochemical process, has been addressed to tackle the ELTs’ problem to reduce the risks as well as increase the material recycling. However, due to the lack of systematic characteristic analysis and modification methods, poor quality of CBp limits the improvement of ELTs pyrolysis in industry applications, which plays a crucial role in the economic feasibility of pyrolysis process. In this review, we have summarized the state-of-the-art characteristics and modification methodologies of the upgrading of CBp, to in-depth understand the surface microstructures and physiochemical properties of CBp for the foundation for modification afterwards. By virtue of the proper selection of modification methods and modifying agents, the new generation of multifunctional carbon materials with desired properties can be instead of the traditional materials of CB, promising broader and various application fields.

关键词: Pyrolysis carbon-blacks     CBp     Post-pyrolysis     Demineralization     Surface modification    

Recent progress in hydrodynamic characteristics research and application of annular centrifugal extractors

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 854-873 doi: 10.1007/s11705-022-2156-0

摘要: The annular centrifugal extractor (ACE) integrates mixing and separation. It has been widely used in many industrial fields because of its low residence time, compact structure, and high mass transfer efficiency. Most of the literature has focused on flow instabilities, flow visualization, and computational fluid dynamics simulations. More recently, research on hydrodynamic behavior and structural optimization has received widespread attention. With the development of ACE technology, applications have been broadened into several new areas. Hence, this paper reviews research progress regarding ACE in terms of hydrodynamic characteristics and the structural improvements. The latest applications covering hydrometallurgy, nuclear fuel reprocessing, bio-extraction, catalytic reaction, and wastewater treatment are presented. We also evaluate future work in droplet breakup and coalescence mechanisms, structural improvements specific to different process requirements, scaling-up methods, and stability and reliability after scaling-up.

关键词: annular centrifugal extractor     hydrodynamic characteristics     structure optimization     the latest application    

Clinical characteristics and outcomes of biopsy-proven diabetic nephropathy

null

《医学前沿(英文)》 2017年 第11卷 第3期   页码 386-392 doi: 10.1007/s11684-017-0574-z

摘要:

Kidney damage is common in patients with diabetes mellitus (DM). However, whether the type of kidney damage can be reliably diagnosed using clinical data alone remains unclear. Predictive factors for diabetic nephropathy (DN) outcomes are also poorly understood. In this study, the clinical manifestations of 111 cases of biopsy-proven DN were described, and the clinical and pathological parameters of patients with different DN outcomes were compared. Results showed that long DM duration (>10 years in 32.4% of patients), severe proteinuria (62.2%), and renal dysfunction (estimated glomerular filtration rate [eGFR]<60 mL/(min·1.73 m2)) (52.3%) did not accurately indicate whether the condition of these patients progressed to DN. Hematuria (48.6%) failed to specify either DN or nondiabetic renal disease. Diabetic retinopathy (78.4%) was a crucial complication in patients with DN. Kaplan–Meier analysis revealed that the renal survival of 53 patients who were diagnosed with DN and were followed up was not significantly associated with glomerular classification (P>0.05). Cox’s regression analysis demonstrated that renal survival time was significantly influenced by sex (b= 1.394, P= 0.038), hematuria (b= 0.036, P= 0.029), and eGFR (b= −0.039, P= 0.002) but was not significantly affected by age, 24 h urinary protein excretion, or glomerular classification (P>0.05). In conclusion, the clinical characteristics of DN vary, and renal biopsy is necessary to determine renal damage patterns. Sex, hematuria, and the eGFR may affect DN outcomes, whereas the glomerular classification may not.

关键词: diabetic nephropathy     clinical characteristics     renal biopsy     outcomes    

Obesity in China: its characteristics, diagnostic criteria, and implications

null

《医学前沿(英文)》 2015年 第9卷 第2期   页码 129-133 doi: 10.1007/s11684-015-0387-x

Cell surface protein engineering for high-performance whole-cell catalysts

Hajime Nakatani,Katsutoshi Hori

《化学科学与工程前沿(英文)》 2017年 第11卷 第1期   页码 46-57 doi: 10.1007/s11705-017-1609-3

摘要: Cell surface protein engineering facilitated by accumulation of information on genome and protein structure involves heterologous production and modification of cell surface proteins using genetic engineering, and is important for the development of high-performance whole-cell catalysts. In this field, cell surface display is a major technology by exposing target proteins, such as enzymes, on the cell surface using a carrier protein. The target proteins are fused to the carrier proteins that transport and tether them to the cell surface, as well as to a secretion signal. This paper reviews cell surface display systems for prokaryotic and eukaryotic cells from the perspective of carrier proteins, which determine the number of displayed molecules, and the localization, size, and direction ( or terminal anchoring) of the passengers. We also discuss advanced methods for displaying multiple enzymes and a new method for the immobilization of whole-cell catalysts using adhesive surface proteins.

关键词: cell surface engineering     surface display     whole-cell catalysts     bioprocess    

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

《工程管理前沿(英文)》 2016年 第3卷 第2期   页码 107-114 doi: 10.15302/J-FEM-2016025

摘要: Surface integrity is the major factor impacting on the operation quality, service life and reliability of the aeroengine components. The surface integrity of aeroengine component is damaged by the failures such as crack, deformation, oxidation, corrosion, erosion, and microstructural degeneration. It adopts advanced remanufacturing technologies to restore or improve the surface integrity and regenerate these high value parts. This paper firstly puts forward the concept, namely surface integrity remanufacturing for aeroengine components, and its connotation. The key remanufacturing technologies have been developed to repair the components with surface damages. Ultimately, some application examples of surface integrity remanufacturing technologies as well as their effects in aeroengine maintenance are introduced. The discarded components have been reused and their service lives have been extended and their reliability has been increased by implementing surface integrity remanufacturing. It has realized “The Repaired Components Outpacing the New Ones”, material saving, energy saving, and emission reduction.

关键词: aeroengine component     surface integrity     remanufacturing     surface integrity remanufacturing    

标题 作者 时间 类型 操作

Surface modification techniques of membranes to improve their antifouling characteristics: recent advancements

期刊论文

Performance and emission characteristics of a diesel engine operating on different water in diesel emulsionfuels: optimization using response surface methodology (RSM)

Seyed Saeed HOSEINI, Mohammad Amin SOBATI

期刊论文

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform

期刊论文

Activity and characteristics of “Oxygen-enriched” highly reactive absorbent for simultaneous flue gas

Yi ZHAO,Tianxiang GUO,Zili ZANG

期刊论文

Characteristics and application of road absorbing solar energy

Zhihua ZHOU, Shan HU, Xiaoyan ZHANG, Jian ZUO

期刊论文

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

期刊论文

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded

Mohammadreza SHABGARD, Hamed KAKOLVAND, Mirsadegh SEYEDZAVVAR, Ramin Mohammadpour SHOTORBANI

期刊论文

Optimization of WEDM process of pure titanium with multiple performance characteristics using Taguchi

Rupesh CHALISGAONKAR, Jatinder KUMAR

期刊论文

Enhanced dewatering characteristics of waste activated sludge with Fenton pretreatment: effectiveness

Guangyin ZHEN, Xueqin LU, Baoying WANG, Youcai ZHAO, Xiaoli CHAI, Dongjie NIU, Tiantao ZHAO

期刊论文

Upgrading pyrolytic carbon-blacks (CBp) from end-of-life tires: Characteristics and modification methodologies

Jiaxue Yu, Junqing Xu, Zhenchen Li, Wenzhi He, Juwen Huang, Junshi Xu, Guangming Li

期刊论文

Recent progress in hydrodynamic characteristics research and application of annular centrifugal extractors

期刊论文

Clinical characteristics and outcomes of biopsy-proven diabetic nephropathy

null

期刊论文

Obesity in China: its characteristics, diagnostic criteria, and implications

null

期刊论文

Cell surface protein engineering for high-performance whole-cell catalysts

Hajime Nakatani,Katsutoshi Hori

期刊论文

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

期刊论文