资源类型

期刊论文 616

会议视频 9

年份

2023 53

2022 50

2021 47

2020 43

2019 50

2018 46

2017 29

2016 26

2015 38

2014 38

2013 34

2012 20

2011 22

2010 18

2009 25

2008 21

2007 23

2006 10

2005 5

2004 4

展开 ︾

关键词

冶金 3

颠覆性技术 3

吸附 2

增材制造 2

新材料 2

智能制造 2

材料 2

材料设计 2

热释放速率 2

碳中和 2

1)模型 1

2019全球工程前沿 1

2035 1

3D 打印 1

4D打印 1

Tetrasphaera 1

BNCT医院中子照射器 1

CO2 捕集 1

COVID-19 1

展开 ︾

检索范围:

排序: 展示方式:

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

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    

Coupling evaluation for material removal and thermal control on precision milling machine tools

《机械工程前沿(英文)》 2022年 第17卷 第1期   页码 12-12 doi: 10.1007/s11465-021-0668-9

摘要: Machine tools are one of the most representative machining systems in manufacturing. The energy consumption of machine tools has been a research hotspot and frontier for green low-carbon manufacturing. However, previous research merely regarded the material removal (MR) energy as useful energy consumption and ignored the useful energy consumed by thermal control (TC) for maintaining internal thermal stability and machining accuracy. In pursuit of energy-efficient, high-precision machining, more attention should be paid to the energy consumption of TC and the coupling relationship between MR and TC. Hence, the cutting energy efficiency model considering the coupling relationship is established based on the law of conservation of energy. An index of energy consumption ratio of TC is proposed to characterize its effect on total energy usage. Furthermore, the heat characteristics are analyzed, which can be adopted to represent machining accuracy. Experimental study indicates that TC is the main energy-consuming process of the precision milling machine tool, which overwhelms the energy consumption of MR. The forced cooling mode of TC results in a 7% reduction in cutting energy efficiency. Regression analysis shows that heat dissipation positively contributes 54.1% to machining accuracy, whereas heat generation negatively contributes 45.9%. This paper reveals the coupling effect of MR and TC on energy efficiency and machining accuracy. It can provide a foundation for energy-efficient, high-precision machining of machine tools.

关键词: machine tools     cutting energy efficiency     thermal stability     machining accuracy     coupling evaluation    

Removal of SO

Xiaolei LI, Chunying ZHU, Youguang MA

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 185-191 doi: 10.1007/s11705-013-1326-5

摘要: In this work, the removal of SO from gas mixture with air and SO by ammonium bicarbonate aqueous solution as absorbent was investigated experimentally in a bubble column reactor. The effects of the concentration of ammonium bicarbonate, the SO inlet concentration of gas phase and the gas flow rate on the removal rate of SO were studied. The results showed that the higher the SO inlet concentration and the gas flow rate, the shorter the lasting time of SO completely removed in gas outlet, and then the faster the decrease in the removal rate of SO . The lasting time of SO completely removed in gas outlet increased with increasing ammonium bicarbonate concentration. During the process of SO absorption, there was a critical pH of solution. When the solution pH was less than the critical pH, it would sharply fall, resulting in a rapid decrease of the SO removal rate. A theoretical model for predicting the SO removal rate has been developed by taking the chemical enhancement and the sulfite concentration in the liquid phase into account simultaneously.

关键词: SO2 removal     bubble column reactor     removal rate     ammonium bicarbonate     absorbent    

The removal of trimethoprim and sulfamethoxazole by a high infiltration rate artificial composite soil

Qinqin Liu,Miao Li,Fawang Zhang,Hechun Yu,Quan Zhang,Xiang Liu

《环境科学与工程前沿(英文)》 2017年 第11卷 第2期 doi: 10.1007/s11783-017-0920-z

摘要: Artificial composite soil treatment system with the high infiltration rate (1.394 m·d ) had a good removal efficiency of TMP (80%–90%) and SMX (60%–70%). The removal mechanism of TMP and SMX was mainly sorption and was related with hydrogeochemical process. Sulfamethoxzole (SMX) and trimethoprim (TMP), two combined-using sulfonamide antibiotics, have gained increasing attention in the surface water, groundwater and the drinking water because of the ecological risk. The removal of TMP and SMX by artificial composite soil treatment system (ACST) with different infiltration rates was systematically investigated using K , Na , Ca , Mg hydrogeochemical indexes. Batch experiments showed that the sorption onto the low-cost and commercially available clay ceramsites was effective for the removal of SMX and TMP from water. The column with more silty clay at high infiltration rate (1.394 m·d ) had removal rates of 80% to 90% for TMP and 60% to 70% for SMX. High SMX and TMP removal rates had a higher effluent concentration of K , Ca and Mg and had a lower effluent Na concentration. Removal was strongly related to sorption. The results showed that the removal of SMX and TMP was related to hydrogeochemical processes. In this study, ACST is determined to be applicable to the drinking water plants.

关键词: Trimethoprim     Sulfamethoxazole     Artificial composite soil treatment     Hydrogeochemical processes     Ion exchange    

Preparation and characterization of a novel microorganism embedding material for simultaneous nitrification

Ming Zeng, Ping Li, Nan Wu, Xiaofang Li, Chang Wang

《环境科学与工程前沿(英文)》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0961-3

摘要: A novel microorganism embedding material was prepared to enhance the biological nitrogen removal through simultaneous nitrification and denitrification. Polyvinyl alcohol (PVA), sodium alginate (SA) and cyclodextrin (CD) were used to compose gel bead with embedded activated sludge. The effects of temperature, CD addition and concentrations of PVA and SA on nitrogen removal were evaluated. Results show that the gel bead with CD addition at 30°C contributed to the highest nitrogen removal efficiency and nitrogen removal rate of 85.4% and 2.08 mg·(L·h)?1, respectively. Meanwhile, negligible NO3? and NO2? were observed, proving the occurrence of simultaneous nitrification and denitrification. The High-Throughput Sequencing confirms that the microbial community mainly contained Comamonadaceae in the proportion of 61.3%. Overall, CD increased gel bead’s porosity and resulted in the high specific endogenous respiration rate and high nitrogen removal efficiency, which is a favorable additional agent to the traditional embedding material.

关键词: Immobilization technology     Nitrogen removal     Cyclodextrin     Microbial community     Wastewater treatment    

Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy

Farouq TWAIQ,M.S. NASSER,Sagheer A. ONAIZI

《化学科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 488-497 doi: 10.1007/s11705-014-1459-1

摘要: The key aim of this study is to evaluate the adsorption of heavy oil from aqueous solutions with different oil contents over mesoporous silicate materials having different surfactant template contents. The mesoporous silicate materials have been synthesized from tetraethylorthosilicate as a silica precursor and cetyltrimethylammonium bromide as a template using the sol-gel technique. Four samples were prepared by (1) totally removing the template using the calcination process, (2) partially removing the template via ethanol extraction, (3) partially removing the template via water extraction, and (4) keeping the template as synthesized, respectively. These four samples have been characterized using X-ray diffraction, nitrogen adsorption, thermal gravimetric analysis and Fourier transformed infrared. The effect of the degree of template removal of these mesoporous materials for the oil removal has been investigated. The oil removal is inversely proportional to the surfactant content in the mesoporous material, being highest for the calcined sample but lowest for the as-synthesized sample. The kinetic of oil adsorption over the calcined material has been also studied and the data obtained fit well a second-order model.

关键词: heavy oil     mesoporous silicate material     kinetics     template removal     adsorption    

Effect of short-term atrazine addition on the performance of an anaerobic/anoxic/oxic process

Changyong WU, Xiaoling LI, Zhiqiang CHEN, Yongzhen PENG,

《环境科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 150-156 doi: 10.1007/s11783-010-0020-9

摘要: In this study, an anaerobic/anoxic/oxic (AO) wastewater treatment process was implemented to treat domestic wastewater with short-term atrazine addition. The results provided an evaluation on the effects of an accidental pollution on the operation of a wastewater treatment plant (WWTP) in relation to Chemical Oxygen Demand (COD) and biological nutrient removal. Domestic wastewater with atrazine addition in 3 continuous days was treated when steady biological nutrient removal was achieved in the AO process. The concentrations of atrazine were 15, 10, and 5mg·L on days 1, 2 and 3, respectively. The results showed that atrazine addition did not affect the removal of COD. The specific NH NO reduction rate decreased slightly due to the short-term atrazine addition. However, it did not affect the nitrogen removal due to the high nitrification and denitrification capacity of the system. Total nitrogen (TN) removal was steady, and more than 70% was removed during the period studied. The phosphorus removal rate was not affected by the short-term addition of atrazine under the applied experimental conditions. However, more poly-hydroxy-alkanoate (PHA) was generated and utilized during atrazine addition. The results of the oxygen uptake rate (OUR) showed that the respiration of nitrifiers decreased significantly, while the activity of carbon utilizers had no obvious change with the atrazine addition. Atrazine was not removed with the AO process, even via absorption by the activated sludge in the process of the short-term addition of atrazine.

关键词: biological nutrient removal     atrazine     anaerobic/anoxic/oxic (A2O) process     oxygen demand removal     oxygen uptake rate (OUR)    

Arsenic (V) removal from groundwater by GE-HL nanofiltration membrane: effects of arsenic concentration

Xiaowei WANG, Wenjun LIU, Weifang MA, Desheng LI,

《环境科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 428-433 doi: 10.1007/s11783-009-0146-9

摘要: A laboratory-scale investigation was performed to study arsenic (As (V)) removal by negatively charged GE-HL nanofiltration (NF) membrane in simulated drinking water. Effects of As (V) concentration (0–200μg·L), pH, and co-ions and counter-ions were investigated. The NF membrane presented good stability, and the rejection rates exceeded 90%. The rejection rates of As (V) decreased with the increase of As (V) concentration, while it increased with the increase of pH (reached 96% at pH 6.75). Moreover, a negative relationship was observed between the co-existing ions of Cl, Na, SO, and Ca and the removal of As (V), in which bivalent ions presented more significant effects than monovalent ions.

关键词: nanofiltration (NF)     rejection rate     co-existing ion     co-ion     counter-ion    

Modification of the activated sludge model for chemical dosage

Shuai MA,Siyu ZENG,Xin DONG,Jining CHEN,Gustaf OLSSON

《环境科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 694-701 doi: 10.1007/s11783-014-0732-3

摘要: Full-scale experiments have been carried out to adapt the activated sludge model ASM2d to include the influence of metal dosage (Fe and Al ) for phosphorus removal. Phosphorus removal rates, nitrification rates, as well as pH and sludge settling performance, were evaluated as functions of the metal dosages. Furthermore, models relating certain parameters to the dosage of chemicals have been derived. Corresponding parameters in the ASM2d and the secondary settler models, included in the Benchmark Simulation Model No 1 (BSM1), have been modified to take the metal influence into consideration. Based on the effluent limits and penalty policy of China, an equivalent evaluation method was derived for the total cost assessment. A large number of 300-day steady-state and 14-day open-loop dynamic simulations were performed to demonstrate the difference in behavior between the original and the modified BSM1. The results show that 1) both in low and high mole concentrations, Fe addition results in a higher phosphorus removal rate than Al ; 2) the sludge settling velocity will increase due to the metal addition; 3) the respiration rate of the activated sludge is decreased more by the dosage of Al than Fe ; 4) the inhibition of Al on the nitrification rate is stronger than that of Fe ; 5) the total operating cost will reach the minimum point for smaller dosages of Fe , but always increase with Al addition.

关键词: chemical precipitation     benchmark simulation model     phosphorus removal     respiratory rate     sludge settling     activated sludge model    

Fiber-reinforced composites in milling and grinding: machining bottlenecks and advanced strategies

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0680-8

摘要: Fiber-reinforced composites have become the preferred material in the fields of aviation and aerospace because of their high-strength performance in unit weight. The composite components are manufactured by near net-shape and only require finishing operations to achieve final dimensional and assembly tolerances. Milling and grinding arise as the preferred choices because of their precision processing. Nevertheless, given their laminated, anisotropic, and heterogeneous nature, these materials are considered difficult-to-machine. As undesirable results and challenging breakthroughs, the surface damage and integrity of these materials is a research hotspot with important engineering significance. This review summarizes an up-to-date progress of the damage formation mechanisms and suppression strategies in milling and grinding for the fiber-reinforced composites reported in the literature. First, the formation mechanisms of milling damage, including delamination, burr, and tear, are analyzed. Second, the grinding mechanisms, covering material removal mechanism, thermal mechanical behavior, surface integrity, and damage, are discussed. Third, suppression strategies are reviewed systematically from the aspects of advanced cutting tools and technologies, including ultrasonic vibration-assisted machining, cryogenic cooling, minimum quantity lubrication (MQL), and tool optimization design. Ultrasonic vibration shows the greatest advantage of restraining machining force, which can be reduced by approximately 60% compared with conventional machining. Cryogenic cooling is the most effective method to reduce temperature with a maximum reduction of approximately 60%. MQL shows its advantages in terms of reducing friction coefficient, force, temperature, and tool wear. Finally, research gaps and future exploration directions are prospected, giving researchers opportunity to deepen specific aspects and explore new area for achieving high precision surface machining of fiber-reinforced composites.

关键词: milling     grinding     fiber-reinforced composites     damage formation mechanism     delamination     material removal mechanism     surface integrity     minimum quantity lubrication    

Mercury removal from aqueous solution using petal-like MoS2

Ragini Pirarath, Palani Shivashanmugam, Asad Syed, Abdallah M. Elgorban, Sambandam Anandan, Muthupandian Ashokkumar

《环境科学与工程前沿(英文)》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1307-0

摘要: Abstract • Synthesized few-layered MoS2 nanosheets via surfactant-assisted hydrothermal method. • Synthesized MoS2 nanosheets show petal-like morphology. • Adsorbent showed 93% of mercury removal efficiency. • The adsorption of mercury is attributed to negative zeta potential (-21.8 mV). Recently, different nanomaterial-based adsorbents have received greater attention for the removal of environmental pollutants, specifically heavy metals from aqueous media. In this work, we synthesized few-layered MoS2 nanosheets via a surfactant-assisted hydrothermal method and utilized them as an efficient adsorbent for the removal of mercury from aqueous media. The synthesized MoS2 nanosheets showed petal-like morphology as confirmed by scanning electron microscope and high-resolution transmission electron microscopic analysis. The average thickness of the nanosheets is found to be about 57 nm. Possessing high stability and negative zeta potential makes this material suitable for efficient adsorption of mercury from aqueous media. The adsorption efficiency of the adsorbent was investigated as a function of pH, contact time and adsorbent dose. The kinetics of adsorption and reusability potential of the adsorbent were also performed. A pseudo-second-order kinetics for mercury adsorption was observed. As prepared MoS2 nanosheets showed 93% mercury removal efficiency, whereas regenerated adsorbent showed 91% and 79% removal efficiency in the respective 2nd and 3rd cycles. The adsorption capacity of the adsorbent was found to be 289 mg/g at room temperature.

关键词: Anionic surfactant     2D material     MoS2 nanosheets     Mercury removal     Adsorption capacity    

The combined effects of biomass and temperature on maximum specific ammonia oxidation rate in domestic

《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1411-9

摘要:

• Actual SAORs was determined using MLVSS and temperature.

关键词: Specific ammonia oxidation rate     Sequencing batch reactor     Biomass     Temperature coefficient     Model simulation    

Liquid metal material genome: Initiation of a new research track towards discovery of advanced energy

Lei WANG, Jing LIU

《能源前沿(英文)》 2013年 第7卷 第3期   页码 317-332 doi: 10.1007/s11708-013-0271-9

摘要: As the basis of modern industry, the roles materials play are becoming increasingly vital in this day and age. With many superior physical properties over conventional fluids, the low melting point liquid metal material, especially room-temperature liquid metal, is recently found to be uniquely useful in a wide variety of emerging areas from energy, electronics to medical sciences. However, with the coming enormous utilization of such materials, serious issues also arise which urgently need to be addressed. A biggest concern to impede the large scale application of room-temperature liquid metal technologies is that there is currently a strong shortage of the materials and species available to meet the tough requirements such as cost, melting point, electrical and thermal conductivity, etc. Inspired by the Material Genome Initiative as issued in 2011 by the United States of America, a more specific and focused project initiative was proposed in this paper—the liquid metal material genome aimed to discover advanced new functional alloys with low melting point so as to fulfill various increasing needs. The basic schemes and road map for this new research program, which is expected to have a worldwide significance, were outlined. The theoretical strategies and experimental methods in the research and development of liquid metal material genome were introduced. Particularly, the calculation of phase diagram (CALPHAD) approach as a highly effective way for material design was discussed. Further, the first-principles (FP) calculation was suggested to combine with the statistical thermodynamics to calculate the thermodynamic functions so as to enrich the CALPHAD database of liquid metals. When the experimental data are too scarce to perform a regular treatment, the combination of FP calculation, cluster variation method (CVM) or molecular dynamics (MD), and CALPHAD, referred to as the mixed FP-CVM-CALPHAD method can be a promising way to solve the problem. Except for the theoretical strategies, several parallel processing experimental methods were also analyzed, which can help improve the efficiency of finding new liquid metal materials and reducing the cost. The liquid metal material genome proposal as initiated in this paper will accelerate the process of finding and utilization of new functional materials.

关键词: liquid metal material genome     energy material     material discovery     advanced material     room-temperature liquid alloy     thermodynamics     phase diagram    

Robust topology optimization of multi-material lattice structures under material and load uncertainties

Yu-Chin CHAN, Kohei SHINTANI, Wei CHEN

《机械工程前沿(英文)》 2019年 第14卷 第2期   页码 141-152 doi: 10.1007/s11465-019-0531-4

摘要: Enabled by advancements in multi-material additive manufacturing, lightweight lattice structures consisting of networks of periodic unit cells have gained popularity due to their extraordinary performance and wide array of functions. This work proposes a density-based robust topology optimization method for meso- or macro-scale multi-material lattice structures under any combination of material and load uncertainties. The method utilizes a new generalized material interpolation scheme for an arbitrary number of materials, and employs univariate dimension reduction and Gauss-type quadrature to quantify and propagate uncertainty. By formulating the objective function as a weighted sum of the mean and standard deviation of compliance, the tradeoff between optimality and robustness can be studied and controlled. Examples of a cantilever beam lattice structure under various material and load uncertainty cases exhibit the efficiency and flexibility of the approach. The accuracy of univariate dimension reduction is validated by comparing the results to the Monte Carlo approach.

关键词: robust topology optimization     lattice structures     multi-material     material uncertainty     load uncertainty     univariate dimension reduction    

Use of float consumption rate in resource leveling of construction projects

Atilla DAMCI, Gul POLAT, Firat Dogu AKIN, Harun TURKOGLU

《工程管理前沿(英文)》 2022年 第9卷 第1期   页码 135-147 doi: 10.1007/s42524-020-0118-0

摘要: The management of resources has been claimed to be as important as scheduling methods. Inefficiency in managing resources may bring about severe delays and cost overruns caused by resource shortages in some cases and/or idle resources in others. Therefore, resources should be utilized efficiently to prevent project failures. Resource leveling is one of the approaches that are used for the management of resources. It aims to minimize fluctuations, peaks, and valleys in resource utilization without changing the completion time of a project and the number of resources required. Although the main principle behind traditional resource leveling is achieving an even flow of resources while the original project duration remains unchanged, the literature supports the need to develop an efficient model that discriminates among the activities that are selected for participation in resource leveling. For this purpose, this study has developed a model that considers the float consumption rates of activities in resource leveling. The float consumption rate is the percentage that is set to determine the maximum amount of float which will be consumed to shift the start time of the activity. The proposed model allows a scheduler to assign float consumption rates to each activity that can be used during the resource leveling procedure. When the required information is inputted, the proposed model automatically changes the required daily resources as it shifts the noncritical activities along their available total float times. The proposed model is expected to minimize the likelihood of severe delays and cost overruns. The model is demonstrated by constructing a network and its resource utilization histograms.

关键词: resource management     resource leveling     float consumption rate     scheduling    

标题 作者 时间 类型 操作

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

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

期刊论文

Coupling evaluation for material removal and thermal control on precision milling machine tools

期刊论文

Removal of SO

Xiaolei LI, Chunying ZHU, Youguang MA

期刊论文

The removal of trimethoprim and sulfamethoxazole by a high infiltration rate artificial composite soil

Qinqin Liu,Miao Li,Fawang Zhang,Hechun Yu,Quan Zhang,Xiang Liu

期刊论文

Preparation and characterization of a novel microorganism embedding material for simultaneous nitrification

Ming Zeng, Ping Li, Nan Wu, Xiaofang Li, Chang Wang

期刊论文

Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy

Farouq TWAIQ,M.S. NASSER,Sagheer A. ONAIZI

期刊论文

Effect of short-term atrazine addition on the performance of an anaerobic/anoxic/oxic process

Changyong WU, Xiaoling LI, Zhiqiang CHEN, Yongzhen PENG,

期刊论文

Arsenic (V) removal from groundwater by GE-HL nanofiltration membrane: effects of arsenic concentration

Xiaowei WANG, Wenjun LIU, Weifang MA, Desheng LI,

期刊论文

Modification of the activated sludge model for chemical dosage

Shuai MA,Siyu ZENG,Xin DONG,Jining CHEN,Gustaf OLSSON

期刊论文

Fiber-reinforced composites in milling and grinding: machining bottlenecks and advanced strategies

期刊论文

Mercury removal from aqueous solution using petal-like MoS2

Ragini Pirarath, Palani Shivashanmugam, Asad Syed, Abdallah M. Elgorban, Sambandam Anandan, Muthupandian Ashokkumar

期刊论文

The combined effects of biomass and temperature on maximum specific ammonia oxidation rate in domestic

期刊论文

Liquid metal material genome: Initiation of a new research track towards discovery of advanced energy

Lei WANG, Jing LIU

期刊论文

Robust topology optimization of multi-material lattice structures under material and load uncertainties

Yu-Chin CHAN, Kohei SHINTANI, Wei CHEN

期刊论文

Use of float consumption rate in resource leveling of construction projects

Atilla DAMCI, Gul POLAT, Firat Dogu AKIN, Harun TURKOGLU

期刊论文