Different amounts of absolute ethanol(0-50 mL)are used as process control agents(PCA)to prepare FeCoNiAlCr0.9 high entropy alloy(HEA)powders via 90 h ball milling.The results show that the increased amount of PCA play...Different amounts of absolute ethanol(0-50 mL)are used as process control agents(PCA)to prepare FeCoNiAlCr0.9 high entropy alloy(HEA)powders via 90 h ball milling.The results show that the increased amount of PCA plays an active role in the crystallinity of powders,and regulate the thickness and size distribution of flake particles.As the volume of PCA increases,the real and imaginary parts(ε′andε″)of complex permittivity get increased by the enhancement of the interface polarization and surface polarization,while the increase in the real and imaginary parts(μ′andμ″)of complex permeability arises from the increased anisotropic energy.The addition of PCA not only promotes the reflection loss but also extends the effective bandwidth(up to 4.28 GHz).Here,the performance adjustment of HEA electromagnetic absorber is realized by forthrightly changing the process parameters of ball milling.展开更多
The influence of process control agents （PCAs） on the mechanical properties of Ni3AI intermetallic compounds by mechanical alloying was investigated in order to develop oxide deposition reinforced intermetallics. Th...The influence of process control agents （PCAs） on the mechanical properties of Ni3AI intermetallic compounds by mechanical alloying was investigated in order to develop oxide deposition reinforced intermetallics. The PCAs in mechanical alloying were pure ligroin, 75 vol.% ligroin ＋ 25 vol.% alcohol, 50 vol.% ligroin ＋ 50 vol.% alcohol, 25 vol.% ligroin ＋ 75 vol.% alcohol, and pure alcohol. The normal composition is Ni-22.9at.%Al-0.5at.%B, the ball-to-powder weight ratio is 10：1, and the milling time is 30 min. Then, the powders were sintered by spark plasma sintering under 40 MPa for 5 min at 1000℃. The results show that a higher bending strength and a higher hardness were obtained when the PCAs were 75% ligroin ＋ 25% alcohol in mechanical alloying. The bending strength is about 2700 MPa and the hardness （HV） is more than 6 GPa.展开更多
The evolutions of microstructure of Fe0.85Ni0.15 products, which were prepared by mechanical alloying (MA) with and without process control agent (PCA), were studied using X-ray diffraction and scanning electron micro...The evolutions of microstructure of Fe0.85Ni0.15 products, which were prepared by mechanical alloying (MA) with and without process control agent (PCA), were studied using X-ray diffraction and scanning electron microscopy respectively. After MA without PCA (dry method) for 30h, Fe0.85Ni0.15 nanocrystalline alloy powders with bcc-Fe(Ni) phase were obtained; however, powders milled with PCA (wet method) from 20 to 90 h, were unalloyed Fe-Ni mixtures with balanced morphology. It seems that dry method works efficiently in nanocrystalline alloying while wet method postpones MA but functionally fines the morphology of materials. Finally, the results were discussed considering the MA kinetics.展开更多
SCADA (Supervisory Control and Data Acquisition) is concerned with gathering process information from industrial control processes found in utilities such as power grids, water networks, transportation, manufacturing,...SCADA (Supervisory Control and Data Acquisition) is concerned with gathering process information from industrial control processes found in utilities such as power grids, water networks, transportation, manufacturing, etc., to provide the human operators with the required real-time access to industrial processes to be monitored and controlled either locally (on-site)or remotely (i.e., through Internet). Conventional solutions such as custom SCADA packages, custom communication protocols, and centralized architectures are no longer appropriate for engineering this type of systems because of their highly distribution and their uncertain continuously changing working environments. Multi-agent systems (MAS) appeared as a new architectural style for engineering complex and highly dynamic applications such as SCADA systems. In this paper, we propose an approach for simply developing flexible and interoperable SCADA systems based on the integration of MAS and OPC process protocol. The proposed SCADA system has the following advantages: 1) simple (easier to be implemented);2) flexible (able to adapt to its environment dynamic changes);and 3) interoperable (relative to the underlying control systems, which belongs to diverse of vendors). The applicability of the proposed approach is demonstrated by a real case study example carried out in a paper mill.展开更多
研究声音增强技术在矿物洗选加工药剂输送控制中的应用,提出一种基于声音增强的矿物洗选加工药剂输送控制方法,通过调控声场特性改善药剂流动态响应性能。利用宽频声学传感器阵列采集管道声学信号,采用小波包分解与归一化最小均方(Norma...研究声音增强技术在矿物洗选加工药剂输送控制中的应用,提出一种基于声音增强的矿物洗选加工药剂输送控制方法,通过调控声场特性改善药剂流动态响应性能。利用宽频声学传感器阵列采集管道声学信号,采用小波包分解与归一化最小均方(Normalized Least Mean Squares,NLMS)算法降噪,实现20~2 000 Hz有效频段的特征提取,结合声场-流场耦合模型设计分层递阶控制系统。实验表明,该技术在矿物洗选加工药剂输送控制中的性能优越,验证了其在复杂工况下的工程适用性。展开更多
基金the National Natural Science Foundation of China(Nos.51577021 and U1704253)the National Key R&D Program of China(No.2017YFB0703103)the Fundamental Research Funds for the Central Universities(No.DUT20GF111)。
文摘Different amounts of absolute ethanol(0-50 mL)are used as process control agents(PCA)to prepare FeCoNiAlCr0.9 high entropy alloy(HEA)powders via 90 h ball milling.The results show that the increased amount of PCA plays an active role in the crystallinity of powders,and regulate the thickness and size distribution of flake particles.As the volume of PCA increases,the real and imaginary parts(ε′andε″)of complex permittivity get increased by the enhancement of the interface polarization and surface polarization,while the increase in the real and imaginary parts(μ′andμ″)of complex permeability arises from the increased anisotropic energy.The addition of PCA not only promotes the reflection loss but also extends the effective bandwidth(up to 4.28 GHz).Here,the performance adjustment of HEA electromagnetic absorber is realized by forthrightly changing the process parameters of ball milling.
文摘The influence of process control agents （PCAs） on the mechanical properties of Ni3AI intermetallic compounds by mechanical alloying was investigated in order to develop oxide deposition reinforced intermetallics. The PCAs in mechanical alloying were pure ligroin, 75 vol.% ligroin ＋ 25 vol.% alcohol, 50 vol.% ligroin ＋ 50 vol.% alcohol, 25 vol.% ligroin ＋ 75 vol.% alcohol, and pure alcohol. The normal composition is Ni-22.9at.%Al-0.5at.%B, the ball-to-powder weight ratio is 10：1, and the milling time is 30 min. Then, the powders were sintered by spark plasma sintering under 40 MPa for 5 min at 1000℃. The results show that a higher bending strength and a higher hardness were obtained when the PCAs were 75% ligroin ＋ 25% alcohol in mechanical alloying. The bending strength is about 2700 MPa and the hardness （HV） is more than 6 GPa.
文摘The evolutions of microstructure of Fe0.85Ni0.15 products, which were prepared by mechanical alloying (MA) with and without process control agent (PCA), were studied using X-ray diffraction and scanning electron microscopy respectively. After MA without PCA (dry method) for 30h, Fe0.85Ni0.15 nanocrystalline alloy powders with bcc-Fe(Ni) phase were obtained; however, powders milled with PCA (wet method) from 20 to 90 h, were unalloyed Fe-Ni mixtures with balanced morphology. It seems that dry method works efficiently in nanocrystalline alloying while wet method postpones MA but functionally fines the morphology of materials. Finally, the results were discussed considering the MA kinetics.
文摘SCADA (Supervisory Control and Data Acquisition) is concerned with gathering process information from industrial control processes found in utilities such as power grids, water networks, transportation, manufacturing, etc., to provide the human operators with the required real-time access to industrial processes to be monitored and controlled either locally (on-site)or remotely (i.e., through Internet). Conventional solutions such as custom SCADA packages, custom communication protocols, and centralized architectures are no longer appropriate for engineering this type of systems because of their highly distribution and their uncertain continuously changing working environments. Multi-agent systems (MAS) appeared as a new architectural style for engineering complex and highly dynamic applications such as SCADA systems. In this paper, we propose an approach for simply developing flexible and interoperable SCADA systems based on the integration of MAS and OPC process protocol. The proposed SCADA system has the following advantages: 1) simple (easier to be implemented);2) flexible (able to adapt to its environment dynamic changes);and 3) interoperable (relative to the underlying control systems, which belongs to diverse of vendors). The applicability of the proposed approach is demonstrated by a real case study example carried out in a paper mill.
文摘研究声音增强技术在矿物洗选加工药剂输送控制中的应用,提出一种基于声音增强的矿物洗选加工药剂输送控制方法,通过调控声场特性改善药剂流动态响应性能。利用宽频声学传感器阵列采集管道声学信号,采用小波包分解与归一化最小均方(Normalized Least Mean Squares,NLMS)算法降噪,实现20~2 000 Hz有效频段的特征提取,结合声场-流场耦合模型设计分层递阶控制系统。实验表明,该技术在矿物洗选加工药剂输送控制中的性能优越,验证了其在复杂工况下的工程适用性。
文摘研究了90W 7Ni 3Fe混合粉末在行星式高能球磨机中的机械合金化(MA)工艺。在一定条件下球磨后,采用XRD分析了粉末相变化、晶块尺寸和晶格畸变,采用SEM对粉末形貌进行了分析。研究了球磨时间、球磨机转速、球料比、球装填系数、不同的表面活性剂等因素对粉末性能的影响。确定了机械合金化制备W Ni Fe纳米复合粉末的最优化工艺:球磨转速为200r/min,球装填系数为6%～12%,球料比为10∶1,液体介质比为V液体∶V(球+料)=1.4～2.0。不同种类的过程控制剂对MA粉末分散和粉末的成形性有很大的影响,采用8#过程控制剂能在有效分散MA粉末的同时具有好的成形性。
