The effects of styrene-butadiene-styrene(SBS)pre-swelling/extraction process and the incorporation of C9 petroleum resin on the anti-aging performance of modified asphalt were systematically evaluated by characterizin...The effects of styrene-butadiene-styrene(SBS)pre-swelling/extraction process and the incorporation of C9 petroleum resin on the anti-aging performance of modified asphalt were systematically evaluated by characterizing the physical indexes,chemical compositions and rheological parameters.The experimental results show that the SBS pre-swelling/extraction process and the incorporation of C9 petroleum resin improve the dispersion performance of SBS in asphalt as well as the strength of SBS polymer network structures,and the synergistic effects decrease the volatilization degree of asphalt lightweight components and the degradation rate of SBS during the aging process.The anti-aging performance of SBS modified asphalt(SBSMA)was significantly enhanced by SBS pre-swelling/extraction process compounded with the incorporation of C9 petroleum resin,and the anti-aging effect was gradually enhanced with the increase of C9 petroleum resin content.展开更多
Disruption of host physiological processes,leading to symptom expression,is a common hallmark during plant virus infections.The concept of“symptoms as strategy”is rapidly reshaping our understanding of plant virolog...Disruption of host physiological processes,leading to symptom expression,is a common hallmark during plant virus infections.The concept of“symptoms as strategy”is rapidly reshaping our understanding of plant virology.An emerging theme is that symptom expressions—such as stunting,curling,and yellowing,which devastate yield—may themselves be evolved viral adaptation strategies rather than collateral damage.展开更多
针对液晶显示器(LCD)面板的“Chip/FPC on Glass”(C/FOG)工艺生产制造过程中存在的计量延迟大、生产异常无法提前预测的问题,本文提出一种基于神经网络的C/FOG工艺生产制造虚拟计量方法。该方法利用生产机台上的传感器采集生产过程中...针对液晶显示器(LCD)面板的“Chip/FPC on Glass”(C/FOG)工艺生产制造过程中存在的计量延迟大、生产异常无法提前预测的问题,本文提出一种基于神经网络的C/FOG工艺生产制造虚拟计量方法。该方法利用生产机台上的传感器采集生产过程中的过程状态数据,构建基于多尺度一维卷积及通道注意力模型(MS1DC-CA)的虚拟计量模型。通过多个尺度的卷积核提取不同尺度范围内的状态数据特征。在对含有缺失值的原始数据预处理中,提出了基于粒子群算法改进的K近邻填补方法(PSO-KNN Imputation)进行缺失值填充,保留特征的同时,减少因填充值引入的干扰。最后在实际生产采集的数据上进行实验对比分析,实际不良率主要集中在0.1%~0.5%,该虚拟计量模型的拟合均方误差为0.397 7‱,低于其他现有拟合模型,在平均绝对误差、对称平均绝对百分比误差和拟合优度3种评价指标下也均优于其他现有的拟合模型,具有良好的预测性能。展开更多
To study the application of TMS320C80 in image processing, an image processing system was designed based on this device, and the task of real time image processing was well accomplished on the hardware platform. TMS3...To study the application of TMS320C80 in image processing, an image processing system was designed based on this device, and the task of real time image processing was well accomplished on the hardware platform. TMS320C80 architecture's high degree of on chip integration and software flexibility will make it widely used in image processing that requires high processing speeds.展开更多
The precipitation process of aged Cu-Ni-Be alloy was investigated by X-ray diffraction （XRD）, trans- mission electron microscopy （TEM）, and high-resolution transmission electron microscopy （HRTEM）. The tensile s...The precipitation process of aged Cu-Ni-Be alloy was investigated by X-ray diffraction （XRD）, trans- mission electron microscopy （TEM）, and high-resolution transmission electron microscopy （HRTEM）. The tensile strength, yield strength, and electronic conductivity of this alloy after aging were also studied. The precipitation sequence of the C17510 alloy aged at 525 ℃ is supersat-urated solid solution→G.P zones→ γ″-γ′→ γ. This transformation can be achieved by the accumulation of Be-atom layers. The G.P zones are composed of disk-shaped monolayers of Be atoms, which are formed on （001） matrix planes. The intermediate γ″ precipitate is nucleated in the G.P zones. The γ″ and γ′ precipitates have the same orientation relationship with matrix, e.g., （110）p｜｜（100）M,[001]p｜｜[001]M. The tensile strength of specimen shows a maximum during the aging process and then continuously decreases if the specimen is over aged. The strengthening effect of γ′ phase precipitated in aging at 525 ℃ for 4 h is calculated to be 436 MPa according to the Orowan strengthening, which is quite consistent with the experimental data.展开更多
PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing ...PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction( XRD),energy dispersive analysis( EDX),transmission electron microscopy( TEM),cyclic voltammetry( CV),chronoamperommetry( CA) and polarization curves in alkaline and acidic electrolytes( single cell experiments). The XRD patterns showPtpeaks are attributed to the face-centered cubic( fcc) structure,and a shift of Pt( fcc) peaks indicates that Ru or In is incorporated into Ptlattice. TEMmicrographs showmetal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. Methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature,by CV and CA. PtRu/C( 50 ∶ 50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80 ℃ showPtRuIn/C( 50 ∶ 25 ∶ 25)with superior performance for methanol oxidation,when compared to Pt/C,PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C( 50 ∶ 25 ∶ 25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Ptalloy.展开更多
C4 components are useful in industry and should be separated as individuals. A new process was proposed to separate them by extractive distillation, with the advantages of low equipment investment, energy consumption...C4 components are useful in industry and should be separated as individuals. A new process was proposed to separate them by extractive distillation, with the advantages of low equipment investment, energy consumption and liquid load in the columns. One principle to improve the extractive distillation process was put forward. Moreover, the analysis of operation state of the new process was done. There were eight operation states found for the whole process, but only one operation state was desirable. This work provides a way to effectively separate C4 mixtures and helps the reasonable utilization of C4 resource.展开更多
E-supply chain is the trend of the supply chain ma na gement. However, building E-supply chain depends on business process improvemen t and re-engineering, which becomes one of the important aspects in supply chai n m...E-supply chain is the trend of the supply chain ma na gement. However, building E-supply chain depends on business process improvemen t and re-engineering, which becomes one of the important aspects in supply chai n management. However, the supply chain process re-engineering and improvement is constrained because of lack of integrating operation framework and standards based on information management. We find that the idea of CALS origins from DoD of USA can solve the problems very well. CALS is the abbreviation of "continues acquisition and life- cycle support". It is an information strategy adopted by many developed counties. The final objective of the CALS is that government a nd industry can generate, exchange, manage and use all the digital information t hroughout the lifecycle of a product in virtue of adopting the international and national standards, improving existing business process and introducing advance d technology. The Integrated Digital Environment (IDE) created by CALS provides a brand new operation mode for consumer, contractor and supplier in supply chain . Besides, a series mutual standard is involved in CALS system. These standards and the standardization technology would be applied widely in the supply chain. This study mainly focuses on supply chain process in CALS environment, and puts forward a framework model of supply chain process. Then the study analyzes the c haracteristics of the model, which includes the application of standards and inf ormation technology, and finally discusses on methods to achieve the supply chai n process in CALS environment.展开更多
In order to explore the effect of carbon and nitrogen(C/N)ratio on the performance of anoxic/aerobic-moving bed bio-film reactor(A/O-MBBR)process for treating mariculture wastewater,a laboratory-scale A/O-MBBR was con...In order to explore the effect of carbon and nitrogen(C/N)ratio on the performance of anoxic/aerobic-moving bed bio-film reactor(A/O-MBBR)process for treating mariculture wastewater,a laboratory-scale A/O-MBBR was conducted.The results showed that the reduction of C/N ratio was conducive to improving the removal efficiency of chemical oxygen demand(COD)and ammonia nitrogen(NH_(4)^(+)-N),while inhibiting that of nitrite nitrogen(NO_(2)^(−)-N)and nitrate nitrogen(NO_(3)^(−)-N).The extracellular polymeric substances(EPS)in anoxic zone were significantly higher in concentration than that in aerobic zone although they both declined with decrease of C/N ratio.The result provides solid support for better controlling the pollution of mariculture wastewater.展开更多
The cloud radio access network(C-RAN) and the fog computing have been recently proposed to tackle the dramatically increasing traffic demands and to provide better quality of service(QoS) to user equipment(UE).Conside...The cloud radio access network(C-RAN) and the fog computing have been recently proposed to tackle the dramatically increasing traffic demands and to provide better quality of service(QoS) to user equipment(UE).Considering the better computation capability of the cloud RAN(10 times larger than that of the fog RAN) and the lower transmission delay of the fog computing,we propose a joint resource allocation and coordinated computation offloading algorithm for the fog RAN(F-RAN),which takes the advantage of C-RAN and fog computing.Specifically,the F-RAN splits a computation task into the fog computing part and the cloud computing part.Based on the constraints of maximum transmission delay tolerance,fronthaul and backhaul capacity limits,we minimize the energy cost and obtain optimal computational resource allocation for multiple UE,transmission power allocation of each UE and the event splitting factor.Numerical results have been proposed with the comparison of existing methods.展开更多
Surface metal matrix composite is produced on the as cast Magnesium Rare Earth alloy-RZ 5 by single pass friction stir processing using various micro/nano sized reinforcement particles namely Boron Carbide(B_(4)C),Mul...Surface metal matrix composite is produced on the as cast Magnesium Rare Earth alloy-RZ 5 by single pass friction stir processing using various micro/nano sized reinforcement particles namely Boron Carbide(B_(4)C),Multi Walled Carbon Nano Tubes(MWCNTs),and a mixture of ZrO_(2)+Al_(2)O_(3)particles.Fine grained metal matrix composites having the grain size ranging 0.8μm to 1.87μm are achieved.Grain boundary pinning by the reinforcement particles has resulted in the transformation of coarse grained(∼81μm)base material into fine grained(<1μm)metal matrix composite.Finer grain structure and the presence of reinforcements at the stir zone have resulted in increased and improved mechanical properties of the developed composites.Microhardness ranging between 125 HV and 403 HV is achieved.Uni-axial Tensile Testing of the developed composites exhibited improvement in tensile strength.Metal matrix composites developed using various reinforcements exhibited an increase in strength ranges between 250 MPa and 320 MPa.展开更多
The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(...The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor.展开更多
By means of hydration heat, XRD and SEM, effect of phosphorus and fluorine （P205 and F-） in phosphorous slag on hydration process of tricalcium silicate （C3S） and tricalcium aluminate （C3A） was explored. The res...By means of hydration heat, XRD and SEM, effect of phosphorus and fluorine （P205 and F-） in phosphorous slag on hydration process of tricalcium silicate （C3S） and tricalcium aluminate （C3A） was explored. The results indicated that the early hydration exothermic rate of C3S and C3A was obviously lowered by P205 and F- in phosphorous slag, the second peak occurring time of C3A was delayed by 0.9 h, the exothermal output of C3S was reduced by 25.04% and the time of accelerating stage was postponed by 0.86 h. The early hydration degree of C3S and C3A was also decreased. Due to the influence of P205 and F, more pores and thinner crystals can be observed in the microstructure of hardened paste and the chance of cracks was reduced.展开更多
Pitch and TiB2/C green composite cathode material were respectively analyzed with simultaneous DSC-TGA, and effects of three baking processes of TiB2/C composite cathode material, i.e. K25, K5 and M5, on properties of...Pitch and TiB2/C green composite cathode material were respectively analyzed with simultaneous DSC-TGA, and effects of three baking processes of TiB2/C composite cathode material, i.e. K25, K5 and M5, on properties of TiB2/C composite cathode material were investigated. The results show that thermogravimetrie behavior of pitch and TiB2/C green composite cathode is similar, and appears the largest mass loss rate in the temperature range from 200 to 600 ℃. The bulk density variation of sample K5 before and after baking is the largest （11.9%）, that of sample K25 is the second, and that of sample M5 is the smallest （6.7%）. The crushing strength of sample M5 is the biggest （51.2 MPa）, that of sample K2.5 is the next, and that of sample K5 is the smallest （32.8 MPa）. But, the orders of the electrical resistivity and electrolysis expansion of samples are just opposite with the order of crushing strength. The heating rate has a great impact on the microstructure of sample. The faster the heating rate is, the bigger the pore size and porosity of sample are. Compared with the heating rate between 200 and 600℃ of samples K25 and K5, that of sample M5 is slower and suitable for baking process of TiB2/C composite cathode material.展开更多
Arid and semiarid ecosystems, or dryland, are important to global biogeochemical cycles. Dryland＇s community structure and vegetation dynamics as well as biogeochemical cycles are sensitive to changes in climate and ...Arid and semiarid ecosystems, or dryland, are important to global biogeochemical cycles. Dryland＇s community structure and vegetation dynamics as well as biogeochemical cycles are sensitive to changes in climate and atmospheric composition. Vegetation dynamic models has been applied in global change studies, but the com- plex interactions among the carbon （C）, water, and nitrogen （N） cycles have not been adequately addressed in the current models. In this study, a process-based vegetation dynamic model was developed to study the responses of dryland ecosystems to environmental changes, emphasizing on the interactions among the C, water, and N proc- esses. To address the interactions between the C and water processes, it not only considers the effects of annual precipitation on vegetation distribution and soil moisture on organic matter （SOM） decomposition, but also explicitly models root competition for water and the water compensation processes. To address the interactions between C and N processes, it models the soil inorganic mater processes, such as N mineralization/immobilization, denitrifica- tion/nitrification, and N leaching, as well as the root competition for soil N. The model was parameterized for major plant functional types and evaluated against field observations.展开更多
A successful mechanical property data-driven prediction model is the core of the optimal design of hot rolling process for hot-rolled strips. However, the original industrial data, usually unbalanced, are inevitably m...A successful mechanical property data-driven prediction model is the core of the optimal design of hot rolling process for hot-rolled strips. However, the original industrial data, usually unbalanced, are inevitably mixed with fluctuant and abnormal values. Models established on the basis of the data without data processing can cause misleading results, which cannot be used for the optimal design of hot rolling process. Thus, a method of industrial data processing of C-Mn steel was proposed based on the data analysis. The Bayesian neural network was employed to establish the reliable mechanical property prediction models for the optimal design of hot rolling process. By using the multi-objective optimization algorithm and considering the individual requirements of costumers and the constraints of the equipment, the optimal design of hot rolling process was successfully applied to the rolling process design for Q345B steel with 0.017% Nb and 0.046% Ti content removed. The optimal process design results were in good agreement with the industrial trials results, which verify the effectiveness of the optimal design of hot rolling process.展开更多
To meet the performance requirements of hot forging die heat resistant layer, the Ni60-SiC coating, Ni60-Cr3C2 coating, and Ni60-WC coating were prepared using W6Mo5Cr4V2 as substrate material with 30%SiC, 10%Cr3C2, 3...To meet the performance requirements of hot forging die heat resistant layer, the Ni60-SiC coating, Ni60-Cr3C2 coating, and Ni60-WC coating were prepared using W6Mo5Cr4V2 as substrate material with 30%SiC, 10%Cr3C2, 30%WC powder by means of plasma spraying and plasma spray re-melting and plasma spray welding, respectively. Microstructure of each carbide coating was analyzed, micro-hardness was tested, and mainly thermal parameters of coating were detected. The experimental results show that using plasma spray welding, the performance of 70%Ni60/30%SiC powder is the best, and its micro-hardness can achieved 1100HV, showing good thermal-physical property.展开更多
High strength-to-weight ratio of non-ferrous alloys, such as aluminium, magnesium and titanium alloys, are considered to be possible replacement of widely accepted steels in transportation and automobile sectors. Amon...High strength-to-weight ratio of non-ferrous alloys, such as aluminium, magnesium and titanium alloys, are considered to be possible replacement of widely accepted steels in transportation and automobile sectors. Among these alloys, magnesium is self explosive and titanium is costlier, and aluminium is most likely to replace steels. Application of aluminium or its alloys is also thought of as an appropriate replacement in defence field, especially to enhance the easiness in mobility of combat vehicles while maintaining the same standard as that of conventional armour grade steels. Hence most of the investigations have been confined to aluminium or its alloys as base material and open an era of developing the newer composite materials to address the major limitation, i.e. tribological properties. The surface composites can be fabricated by incorporating the ceramic carbides like silicon carbide, carbides of transition metals and oxides of aluminium using surface modification techniques, such as high energy laser melt treatment, high energy electron beam irradiation and thermal spray process which are based on fusion route. These techniques yield the fusion related problems, such as interfacial reaction, pin holes, shrinkage cavities or voids and other casting related defects, and pave the way to need of an efficient technique which must be based on solid state. Recently developed friction stir processing technique was used in the present investigation for surface modification of AA7075 aluminum alloy, which is an alternative to steels. In the present investigation, 160 μm sized boron carbide powder was procured and was reduced to 60 μm and 30 μm using high energy ball mill. Subsequently these powders were used to fabricate the surface composites using friction stir processing.Ballistic performance testing as per the military standard(JIS.0108.01) was carried out. In the present work, an analytical method of predicting the ballistic behavior of surface composites was developed. This method was based on energy balance, i.e., the initial energy of impact is same as that of energy absorbed by multi layers. An attempt also has been made to validate the analytical results with the experimental findings. Variation between the analytical and experimental results may be accounted due to the assumptions considering such as isotropic behavior of target and shearing area of contact as cylindrical instead of conical interface As the analytical model yields the ballistic performance in the closer proximity of experimentally obtained, it can be considered to be an approximation to evaluate the ballistic performance of targets.展开更多
In this paper, with the aid of large deviation formulas established in strong topology of functional space generated by HSlder norm, we discuss the functional sample path properties of subsequence＇s C-R increments fo...In this paper, with the aid of large deviation formulas established in strong topology of functional space generated by HSlder norm, we discuss the functional sample path properties of subsequence＇s C-R increments for a Wiener process in HSlder norm. The obtained results, generalize the corresponding results of Chen and the classic Strassen＇s law of iterated logarithm for a Wiener process.展开更多
基金Fnded by the National Key Research and Development Program of China(No.2023YFC3807202)the Key Research and Development Plan in Hubei Province of China(Nos.2022BCA082 and 2024BAB108)the Annual Research Project of China Railway Construction Corporation(No.2023-B03)。
文摘The effects of styrene-butadiene-styrene(SBS)pre-swelling/extraction process and the incorporation of C9 petroleum resin on the anti-aging performance of modified asphalt were systematically evaluated by characterizing the physical indexes,chemical compositions and rheological parameters.The experimental results show that the SBS pre-swelling/extraction process and the incorporation of C9 petroleum resin improve the dispersion performance of SBS in asphalt as well as the strength of SBS polymer network structures,and the synergistic effects decrease the volatilization degree of asphalt lightweight components and the degradation rate of SBS during the aging process.The anti-aging performance of SBS modified asphalt(SBSMA)was significantly enhanced by SBS pre-swelling/extraction process compounded with the incorporation of C9 petroleum resin,and the anti-aging effect was gradually enhanced with the increase of C9 petroleum resin content.
基金supported by the National Natural Science Foundation of China(32272482)the Innovation Research 2035 Pilot Plan of Southwest University(SWU-XDZD22002).
文摘Disruption of host physiological processes,leading to symptom expression,is a common hallmark during plant virus infections.The concept of“symptoms as strategy”is rapidly reshaping our understanding of plant virology.An emerging theme is that symptom expressions—such as stunting,curling,and yellowing,which devastate yield—may themselves be evolved viral adaptation strategies rather than collateral damage.
文摘针对液晶显示器(LCD)面板的“Chip/FPC on Glass”(C/FOG)工艺生产制造过程中存在的计量延迟大、生产异常无法提前预测的问题,本文提出一种基于神经网络的C/FOG工艺生产制造虚拟计量方法。该方法利用生产机台上的传感器采集生产过程中的过程状态数据,构建基于多尺度一维卷积及通道注意力模型(MS1DC-CA)的虚拟计量模型。通过多个尺度的卷积核提取不同尺度范围内的状态数据特征。在对含有缺失值的原始数据预处理中,提出了基于粒子群算法改进的K近邻填补方法(PSO-KNN Imputation)进行缺失值填充,保留特征的同时,减少因填充值引入的干扰。最后在实际生产采集的数据上进行实验对比分析,实际不良率主要集中在0.1%~0.5%,该虚拟计量模型的拟合均方误差为0.397 7‱,低于其他现有拟合模型,在平均绝对误差、对称平均绝对百分比误差和拟合优度3种评价指标下也均优于其他现有的拟合模型,具有良好的预测性能。
文摘To study the application of TMS320C80 in image processing, an image processing system was designed based on this device, and the task of real time image processing was well accomplished on the hardware platform. TMS320C80 architecture's high degree of on chip integration and software flexibility will make it widely used in image processing that requires high processing speeds.
基金financially supported by the Project of Science and Technology of Beijing(No.10231103)
文摘The precipitation process of aged Cu-Ni-Be alloy was investigated by X-ray diffraction （XRD）, trans- mission electron microscopy （TEM）, and high-resolution transmission electron microscopy （HRTEM）. The tensile strength, yield strength, and electronic conductivity of this alloy after aging were also studied. The precipitation sequence of the C17510 alloy aged at 525 ℃ is supersat-urated solid solution→G.P zones→ γ″-γ′→ γ. This transformation can be achieved by the accumulation of Be-atom layers. The G.P zones are composed of disk-shaped monolayers of Be atoms, which are formed on （001） matrix planes. The intermediate γ″ precipitate is nucleated in the G.P zones. The γ″ and γ′ precipitates have the same orientation relationship with matrix, e.g., （110）p｜｜（100）M,[001]p｜｜[001]M. The tensile strength of specimen shows a maximum during the aging process and then continuously decreases if the specimen is over aged. The strengthening effect of γ′ phase precipitated in aging at 525 ℃ for 4 h is calculated to be 436 MPa according to the Orowan strengthening, which is quite consistent with the experimental data.
文摘PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction( XRD),energy dispersive analysis( EDX),transmission electron microscopy( TEM),cyclic voltammetry( CV),chronoamperommetry( CA) and polarization curves in alkaline and acidic electrolytes( single cell experiments). The XRD patterns showPtpeaks are attributed to the face-centered cubic( fcc) structure,and a shift of Pt( fcc) peaks indicates that Ru or In is incorporated into Ptlattice. TEMmicrographs showmetal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. Methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature,by CV and CA. PtRu/C( 50 ∶ 50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80 ℃ showPtRuIn/C( 50 ∶ 25 ∶ 25)with superior performance for methanol oxidation,when compared to Pt/C,PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C( 50 ∶ 25 ∶ 25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Ptalloy.
文摘C4 components are useful in industry and should be separated as individuals. A new process was proposed to separate them by extractive distillation, with the advantages of low equipment investment, energy consumption and liquid load in the columns. One principle to improve the extractive distillation process was put forward. Moreover, the analysis of operation state of the new process was done. There were eight operation states found for the whole process, but only one operation state was desirable. This work provides a way to effectively separate C4 mixtures and helps the reasonable utilization of C4 resource.
文摘E-supply chain is the trend of the supply chain ma na gement. However, building E-supply chain depends on business process improvemen t and re-engineering, which becomes one of the important aspects in supply chai n management. However, the supply chain process re-engineering and improvement is constrained because of lack of integrating operation framework and standards based on information management. We find that the idea of CALS origins from DoD of USA can solve the problems very well. CALS is the abbreviation of "continues acquisition and life- cycle support". It is an information strategy adopted by many developed counties. The final objective of the CALS is that government a nd industry can generate, exchange, manage and use all the digital information t hroughout the lifecycle of a product in virtue of adopting the international and national standards, improving existing business process and introducing advance d technology. The Integrated Digital Environment (IDE) created by CALS provides a brand new operation mode for consumer, contractor and supplier in supply chain . Besides, a series mutual standard is involved in CALS system. These standards and the standardization technology would be applied widely in the supply chain. This study mainly focuses on supply chain process in CALS environment, and puts forward a framework model of supply chain process. Then the study analyzes the c haracteristics of the model, which includes the application of standards and inf ormation technology, and finally discusses on methods to achieve the supply chai n process in CALS environment.
基金This work was supported by the National Key Research and Development Program of China(No.2018 YFC1407601)the Start-up Foundation for Introducing Talent of NUIST and Guangxi Innovation Driven Development Project(major science and technology project).
文摘In order to explore the effect of carbon and nitrogen(C/N)ratio on the performance of anoxic/aerobic-moving bed bio-film reactor(A/O-MBBR)process for treating mariculture wastewater,a laboratory-scale A/O-MBBR was conducted.The results showed that the reduction of C/N ratio was conducive to improving the removal efficiency of chemical oxygen demand(COD)and ammonia nitrogen(NH_(4)^(+)-N),while inhibiting that of nitrite nitrogen(NO_(2)^(−)-N)and nitrate nitrogen(NO_(3)^(−)-N).The extracellular polymeric substances(EPS)in anoxic zone were significantly higher in concentration than that in aerobic zone although they both declined with decrease of C/N ratio.The result provides solid support for better controlling the pollution of mariculture wastewater.
基金supported in part by National Natural Science Foundation of China(No. 61372070)Natural Science Basic Research Plan in Shaanxi Province of China(No. 2015JM6324)+3 种基金Ningbo Natural Science Foundation(2015A610117)Hong Kong, Macao and Taiwan Science & Technology Cooperation Program of China(No. 2015DFT10160)EU FP7 Project MONICA (No.PIRSES-GA-2011-295222)the 111 Project(No.B08038)
文摘The cloud radio access network(C-RAN) and the fog computing have been recently proposed to tackle the dramatically increasing traffic demands and to provide better quality of service(QoS) to user equipment(UE).Considering the better computation capability of the cloud RAN(10 times larger than that of the fog RAN) and the lower transmission delay of the fog computing,we propose a joint resource allocation and coordinated computation offloading algorithm for the fog RAN(F-RAN),which takes the advantage of C-RAN and fog computing.Specifically,the F-RAN splits a computation task into the fog computing part and the cloud computing part.Based on the constraints of maximum transmission delay tolerance,fronthaul and backhaul capacity limits,we minimize the energy cost and obtain optimal computational resource allocation for multiple UE,transmission power allocation of each UE and the event splitting factor.Numerical results have been proposed with the comparison of existing methods.
文摘Surface metal matrix composite is produced on the as cast Magnesium Rare Earth alloy-RZ 5 by single pass friction stir processing using various micro/nano sized reinforcement particles namely Boron Carbide(B_(4)C),Multi Walled Carbon Nano Tubes(MWCNTs),and a mixture of ZrO_(2)+Al_(2)O_(3)particles.Fine grained metal matrix composites having the grain size ranging 0.8μm to 1.87μm are achieved.Grain boundary pinning by the reinforcement particles has resulted in the transformation of coarse grained(∼81μm)base material into fine grained(<1μm)metal matrix composite.Finer grain structure and the presence of reinforcements at the stir zone have resulted in increased and improved mechanical properties of the developed composites.Microhardness ranging between 125 HV and 403 HV is achieved.Uni-axial Tensile Testing of the developed composites exhibited improvement in tensile strength.Metal matrix composites developed using various reinforcements exhibited an increase in strength ranges between 250 MPa and 320 MPa.
基金supported by the Science Development Funding Program of Dongying of China(Grant No.DJ2021006)Science Development Funding Program of Dongying of China(Grant No.DJ2021008).
文摘The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor.
基金Funded by the National Natural Science Foundation of China (No.50802067)
文摘By means of hydration heat, XRD and SEM, effect of phosphorus and fluorine （P205 and F-） in phosphorous slag on hydration process of tricalcium silicate （C3S） and tricalcium aluminate （C3A） was explored. The results indicated that the early hydration exothermic rate of C3S and C3A was obviously lowered by P205 and F- in phosphorous slag, the second peak occurring time of C3A was delayed by 0.9 h, the exothermal output of C3S was reduced by 25.04% and the time of accelerating stage was postponed by 0.86 h. The early hydration degree of C3S and C3A was also decreased. Due to the influence of P205 and F, more pores and thinner crystals can be observed in the microstructure of hardened paste and the chance of cracks was reduced.
基金Project (2005CB623703) supported by the Major State Basic Research and Development Program of ChinaProject (2008AA030502) supported by the National High-Tech Research and Development Program of China
文摘Pitch and TiB2/C green composite cathode material were respectively analyzed with simultaneous DSC-TGA, and effects of three baking processes of TiB2/C composite cathode material, i.e. K25, K5 and M5, on properties of TiB2/C composite cathode material were investigated. The results show that thermogravimetrie behavior of pitch and TiB2/C green composite cathode is similar, and appears the largest mass loss rate in the temperature range from 200 to 600 ℃. The bulk density variation of sample K5 before and after baking is the largest （11.9%）, that of sample K25 is the second, and that of sample M5 is the smallest （6.7%）. The crushing strength of sample M5 is the biggest （51.2 MPa）, that of sample K2.5 is the next, and that of sample K5 is the smallest （32.8 MPa）. But, the orders of the electrical resistivity and electrolysis expansion of samples are just opposite with the order of crushing strength. The heating rate has a great impact on the microstructure of sample. The faster the heating rate is, the bigger the pore size and porosity of sample are. Compared with the heating rate between 200 and 600℃ of samples K25 and K5, that of sample M5 is slower and suitable for baking process of TiB2/C composite cathode material.
基金supported by the International Science & Technology Cooperation Program of China (2010DFA92720-10)the "Hundred Talents Program" of the Chinese Academy of Sciences (Y174131001)supported by the National Basic Research Program of China (2009CB825105)
文摘Arid and semiarid ecosystems, or dryland, are important to global biogeochemical cycles. Dryland＇s community structure and vegetation dynamics as well as biogeochemical cycles are sensitive to changes in climate and atmospheric composition. Vegetation dynamic models has been applied in global change studies, but the com- plex interactions among the carbon （C）, water, and nitrogen （N） cycles have not been adequately addressed in the current models. In this study, a process-based vegetation dynamic model was developed to study the responses of dryland ecosystems to environmental changes, emphasizing on the interactions among the C, water, and N proc- esses. To address the interactions between the C and water processes, it not only considers the effects of annual precipitation on vegetation distribution and soil moisture on organic matter （SOM） decomposition, but also explicitly models root competition for water and the water compensation processes. To address the interactions between C and N processes, it models the soil inorganic mater processes, such as N mineralization/immobilization, denitrifica- tion/nitrification, and N leaching, as well as the root competition for soil N. The model was parameterized for major plant functional types and evaluated against field observations.
文摘A successful mechanical property data-driven prediction model is the core of the optimal design of hot rolling process for hot-rolled strips. However, the original industrial data, usually unbalanced, are inevitably mixed with fluctuant and abnormal values. Models established on the basis of the data without data processing can cause misleading results, which cannot be used for the optimal design of hot rolling process. Thus, a method of industrial data processing of C-Mn steel was proposed based on the data analysis. The Bayesian neural network was employed to establish the reliable mechanical property prediction models for the optimal design of hot rolling process. By using the multi-objective optimization algorithm and considering the individual requirements of costumers and the constraints of the equipment, the optimal design of hot rolling process was successfully applied to the rolling process design for Q345B steel with 0.017% Nb and 0.046% Ti content removed. The optimal process design results were in good agreement with the industrial trials results, which verify the effectiveness of the optimal design of hot rolling process.
文摘To meet the performance requirements of hot forging die heat resistant layer, the Ni60-SiC coating, Ni60-Cr3C2 coating, and Ni60-WC coating were prepared using W6Mo5Cr4V2 as substrate material with 30%SiC, 10%Cr3C2, 30%WC powder by means of plasma spraying and plasma spray re-melting and plasma spray welding, respectively. Microstructure of each carbide coating was analyzed, micro-hardness was tested, and mainly thermal parameters of coating were detected. The experimental results show that using plasma spray welding, the performance of 70%Ni60/30%SiC powder is the best, and its micro-hardness can achieved 1100HV, showing good thermal-physical property.
基金Financial assistance from Armament research board,New Delhi,India
文摘High strength-to-weight ratio of non-ferrous alloys, such as aluminium, magnesium and titanium alloys, are considered to be possible replacement of widely accepted steels in transportation and automobile sectors. Among these alloys, magnesium is self explosive and titanium is costlier, and aluminium is most likely to replace steels. Application of aluminium or its alloys is also thought of as an appropriate replacement in defence field, especially to enhance the easiness in mobility of combat vehicles while maintaining the same standard as that of conventional armour grade steels. Hence most of the investigations have been confined to aluminium or its alloys as base material and open an era of developing the newer composite materials to address the major limitation, i.e. tribological properties. The surface composites can be fabricated by incorporating the ceramic carbides like silicon carbide, carbides of transition metals and oxides of aluminium using surface modification techniques, such as high energy laser melt treatment, high energy electron beam irradiation and thermal spray process which are based on fusion route. These techniques yield the fusion related problems, such as interfacial reaction, pin holes, shrinkage cavities or voids and other casting related defects, and pave the way to need of an efficient technique which must be based on solid state. Recently developed friction stir processing technique was used in the present investigation for surface modification of AA7075 aluminum alloy, which is an alternative to steels. In the present investigation, 160 μm sized boron carbide powder was procured and was reduced to 60 μm and 30 μm using high energy ball mill. Subsequently these powders were used to fabricate the surface composites using friction stir processing.Ballistic performance testing as per the military standard(JIS.0108.01) was carried out. In the present work, an analytical method of predicting the ballistic behavior of surface composites was developed. This method was based on energy balance, i.e., the initial energy of impact is same as that of energy absorbed by multi layers. An attempt also has been made to validate the analytical results with the experimental findings. Variation between the analytical and experimental results may be accounted due to the assumptions considering such as isotropic behavior of target and shearing area of contact as cylindrical instead of conical interface As the analytical model yields the ballistic performance in the closer proximity of experimentally obtained, it can be considered to be an approximation to evaluate the ballistic performance of targets.
基金Supported by the Natural Science Foundation of Hubei Province of China(2011CDB229)
文摘In this paper, with the aid of large deviation formulas established in strong topology of functional space generated by HSlder norm, we discuss the functional sample path properties of subsequence＇s C-R increments for a Wiener process in HSlder norm. The obtained results, generalize the corresponding results of Chen and the classic Strassen＇s law of iterated logarithm for a Wiener process.
