The machine learning models of multiple linear regression(MLR),support vector regression(SVR),and extreme learning ma-chine(ELM)and the proposed ELM models of online sequential ELM(OS-ELM)and OS-ELM with forgetting me...
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The machine learning models of multiple linear regression(MLR),support vector regression(SVR),and extreme learning ma-chine(ELM)and the proposed ELM models of online sequential ELM(OS-ELM)and OS-ELM with forgetting mechanism(FOS-ELM)are applied in the prediction of the lime utilization ratio of dephosphorization in the basic oxygen furnace steelmaking *** ELM model exhibites the best performance compared with the models of MLR and ***-ELM and FOS-ELM are applied for sequential learning and model *** optimal number of samples in validity term of the FOS-ELM model is determined to be 1500,with the smallest population mean absolute relative error(MARE)value of 0.058226 for the *** variable importance analysis reveals lime weight,initial P content,and hot metal weight as the most important variables for the lime utilization *** lime utilization ratio increases with the decrease in lime weight and the increases in the initial P content and hot metal weight.A prediction system based on FOS-ELM is applied in actual industrial production for one *** hit ratios of the predicted lime utilization ratio in the error ranges of±1%,±3%,and±5%are 61.16%,90.63%,and 94.11%,*** coefficient of determination,MARE,and root mean square error are 0.8670,0.06823,and 1.4265,*** system exhibits desirable performance for applications in actual industrial pro-duction.
The mechanisms of oxide metallurgy include inducing the formation of intragranular acicular ferrite(IAF)using micron-sized inclusions and restricting the growth of prior austenite grains(PAGs)by nanosized particles du...
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The mechanisms of oxide metallurgy include inducing the formation of intragranular acicular ferrite(IAF)using micron-sized inclusions and restricting the growth of prior austenite grains(PAGs)by nanosized particles during *** chaotically oriented IAF and refined PAGs inhibit crack initiation and propagation in the steel,resulting in high impact *** work summarizes the com-bined effect of deoxidizers and alloying elements,with the aim to provide a new perspective for the research and practice related to im-proving the impact toughness of the heat affected zone(HAZ)during the high heat input *** complex deoxidation with other strong deoxidants,such as Mg,Ca,Zr,and rare earth metals(REMs),can improve the toughness of the heat-affected zone(HAZ)by re-fining PAGs or increasing IAF ***,it is difficult to identify the specific phase responsible for IAF nucleation because ef-fective inclusions formed by complex deoxidation are usually *** alloying elements,such as C,Si,Al,Nb,or Cr,con-tents can impair HAZ toughness.A high C content typically increases the number of coarse carbides and decreases the potency of IAF ***,Cr,or Al addition leads to the formation of undesirable *** reduces the high-temperature stability of the ***,V,and B can enhance HAZ ***-containing precipitates present good thermal *** or V(C,N)is ef-fective in promoting IAF nucleation due to its good coherent crystallographic relationship with *** formation of the B-depleted zone around the inclusion promotes IAF *** interactions between alloying elements are complex,and the effect of adding dif-ferent alloying elements remains to be *** the future,the interactions between various alloying elements and their effects on ox-ide metallurgy,as well as the calculation of the nucleation effects of effective inclusions using first principles calculations will become the focus of
With the large-scale service of lithium-ion batteries(LIBs),their failures have attracted significant *** the decay of active materials is the primary cause for LIB failures,the degradation of auxiliary materials,such...
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With the large-scale service of lithium-ion batteries(LIBs),their failures have attracted significant *** the decay of active materials is the primary cause for LIB failures,the degradation of auxiliary materials,such as current collector corrosion,should not be ***,it is necessary to conduct a comprehensive review in this *** this review,from the perspectives of electrochemistry and materials,we systematically summarize the corrosion behavior of aluminum cathode current collector and propose corresponding ***,the corrosion type is clarified based on the properties of passivation layers in different organic electrolyte ***,a thoroughgoing analysis is presented to examine the impact of various factors on aluminum corrosion,including lithium salts,organic solvents,water impurities,and operating ***,strategies for electrolyte and protection layer employed to suppress corrosion are discussed in *** and most importantly,we provide insights and recommendations to prevent corrosion of current collectors,facilitate the development of advanced current collectors and the implementation of next-generation high-voltage stable LIBs.
The electrocatalytic conversion of CO_(2)to produce fuels and chemicals holds great promise,not only to provide an alternative to fossil feedstocks,but also to use renewable electricity to convert and recycle the gree...
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The electrocatalytic conversion of CO_(2)to produce fuels and chemicals holds great promise,not only to provide an alternative to fossil feedstocks,but also to use renewable electricity to convert and recycle the greenhouse gas CO_(2)to mitigate climate ***,the selectivity and reaction rates for the conversion of CO_(2)into desirable carbon-based products,especially multicarbon products with high added value,are still insufficient for commercial applications,which is attributed to insufficiently favourable microenvironmental conditions in the vicinity of the *** construction of catalysts/electrodes with confined structures can effectively improve the reaction microenvironment in the vicinity of the electrodes and thus effectively direct the reaction towards the desired *** this review,we firstly introduce the effects of the microenvironment at the electrode-electrolyte interface including local pH,local intermediate concentration,and local cation concentration on CO_(2)reduction reaction(CO_(2)RR)as well as the mechanism of action,and then shed light on the microenvironmental modulation within the confined space,and finally and most importantly,introduce the design strategy of CO_(2)RR catalyst/electrode based on the confinement effect.
Solar-driven CO2conversion into value-added chemical provides an attractive strategy for sustainable ***,the enhanced CO2photoreduction performance with target product selectivity remains a major ***,we develop a nove...
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Solar-driven CO2conversion into value-added chemical provides an attractive strategy for sustainable ***,the enhanced CO2photoreduction performance with target product selectivity remains a major ***,we develop a novel strategy involving Cu2O nanoparticles in situ grown on the surface of ZIF-67-derived Co@C-N nanocages(CC) to create abundant active sites and appropriate heterointerfaces.A remarkable CO selectivity of 95.7% with a yield of 117.39 μmol g-1h-1and an apparent quantum efficiency as high as 1.88% at 420 nm was obtained over CC-60 catalyst in pure water,which was 87.6 times higher than that of pure *** calculations and experiments indicated that Co@C-N nanocages as charge mediator not only rapidly trap photogenerated electrons to promote charge separation efficiency,but also regulate the d-band center of Cu atoms to move to the Fermi energy level,thereby optimizing the reaction kinetics to facilitate the highly selective conversion of the key intermediate*CO desorption to CO.
Magnesium and aluminum alloys are widely used in various industries because of their excellent properties,and their reliable connection may increase application of *** compounds(IMCs)affect the joint performance of Mg...
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Magnesium and aluminum alloys are widely used in various industries because of their excellent properties,and their reliable connection may increase application of *** compounds(IMCs)affect the joint performance of Mg/*** this study,AZ31 Mg alloy with/without a nickel(Ni)coating layer and 6061 Al alloy were joined by ultrasonic-assisted soldering with Sn-3.0Ag-0.5Cu(SAC)*** effects of the Ni coating layer on the microstructure and mechanical properties of Mg/Al joints were systematically *** Ni coating layer had a significant effect on formation of the Mg_(2)Sn IMC and the mechanical properties of Mg/Al *** blocky Mg_(2)Sn IMC formed in the Mg/SAC/Al joints without a Ni coating *** content of the Mg_(2)Sn IMC increased with increasing soldering temperature,but the joint strength *** joint without a Ni coating layer fractured at the blocky Mg_(2)Sn IMC in the solder,and the maximum shear strength was 32.2 *** pre-plating Ni on the Mg substrate,formation of the blocky Mg_(2)Sn IMC was inhibited in the soldering temperature range 240–280℃and the joint strength ***,when the soldering temperature increased to 310℃,the blocky Mg_(2)Sn IMC precipitated again in the *** electron microscopy showed that some nano-sized Mg_(2)Sn IMC and the(Cu,Ni)_(6)Sn_(5)phase formed in the Mg(Ni)/SAC/Al joint soldered at 280℃,indicating that the Ni coating layer could no longer prevent diffusion of Mg into the solder when the soldering temperature was higher than 280℃.The maximum shear strength of the Mg(Ni)/SAC/Al joint was 58.2 MPa for a soldering temperature of 280℃,which was 80.7%higher than that of the Mg/SAC/Al joint,and the joint was broken at the Mg(Ni)/SAC ***-plating Ni is a feasible way to inhibit formation of IMCs when joining dissimilar metals.
Due to its excellent biocompatibility and biodegradability,Mg and its alloys are considered to be promising materials for manufacturing of vascular ***,the manufacture of high-precision and high-performance Mg alloys ...
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Due to its excellent biocompatibility and biodegradability,Mg and its alloys are considered to be promising materials for manufacturing of vascular ***,the manufacture of high-precision and high-performance Mg alloys minitubes is still a worldwide problem with a long manufacturing processing caused by the poor workability of Mg *** solve this problem,the cyclic extrusion compression(CEC)was used to pretreat the billet by improving the workability of Mg alloys,finally shortening the manufacturing *** CEC treatment,the size of grains and second phase particles of Mg alloys were dramatically refined to 3.2μm and 0.3μm,*** after three passes of cold drawing,the wall thickness of minitube was reduced from 0.200 mm to 0.135 mm and a length was more than 1000 *** error of wall thickness was measured to be less than 0.01 mm,implying a high dimensional *** yield strength(YS),ultimate tensile strength(UTS)and elongation of finished minitube were 220±10 MPa,290±10 MPa and 22.0±0.5%,*** addition,annealing can improve mechanical property and corrosion resistance of minitubes by improving the homogeneity of the microstructure and enhancing the density of basal texture.
The application of bulk nanocrystalline Nd-Fe-B permanent magnets manufactured by hot deformation methods was severely limited by production ***,this work proposed an efficient prepa-ration method combining hot rollin...
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The application of bulk nanocrystalline Nd-Fe-B permanent magnets manufactured by hot deformation methods was severely limited by production ***,this work proposed an efficient prepa-ration method combining hot rolling and *** the melt-spun Nd-Fe-B magnetic powders as original materials,dense,large-sized,and well-uniform precursors for deformation can be obtained through cold pressing and hot *** large-sized hot-rolled magnet can be cut into small pieces and subjected to hot *** deformed magnet exhibits obvious crystallographic anisotropy,and the optimal maximum energy product can reach 35.7 ***,the mechanism of defor-mation and texture formation has been systematically studied,according to the microstructure and tex-ture characterization of different height reduction *** results indicated that there was a typical heterogeneous structure in the hot-rolled and hot-deformed Nd-Fe-B *** precipitation,grain growth,and regular grain arrangement were the main reasons for deformation and texture forma-tion during the deformation *** strategy of replacing traditional hot-pressing with large-sized hot-rolling can produce massively deformed precursors at once,greatly improving production efficiency,which is crucial for promoting the application of bulk nanocrystalline anisotropic Nd-Fe-B permanent magnets.
Silicon monoxide(SiOx) has garnered considerable attention as an anode material owing to its high ***, its commercial viability is hampered by the low conductivity and inadequate cycling stability. In this study, a ...
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Silicon monoxide(SiOx) has garnered considerable attention as an anode material owing to its high ***, its commercial viability is hampered by the low conductivity and inadequate cycling stability. In this study, a micrometer-scale silicon oxide/carbon composite(1000-SiOx/NC) was developed based on the porous and high electrical conductivity of pyrolyzed polydopamine(PDA) and the high-temperature disproportionation of SiOx. Electrochemical impedance spectroscopy(EIS) and X-ray photoelectron spectroscopy(XPS)analyses confirmed that the pyrolysis of polydopamine(PDA) not only improves electrode conductivity but also contributes to the formation of a stable solid electrolyte interface(SEI). Additionally, SiOxundergoes disproportionation reactions during the pyrolysis of PDA, further the improves the cyclic stability of the ***, the 1000-SiOx/NC composite electrode exhibited an impressive specific capacity of 783.4 mAh·g-1after 500 cycles at 1 A g-1, maintaining 80.1 % of its initial capacity. Additionally, at a high rate of 3 C, its capacity reached 607.3 mAh·g-1The synthesis approach is both straightforward and economical, offering a fresh avenue for the widespread commercial deployment of SiOx.
*** High strength and large deformability are greatly desirable for advanced structural metallic *** strengthening methods in crystalline materials rely on controlling the generation,propagation,and intersection of di...
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*** High strength and large deformability are greatly desirable for advanced structural metallic *** strengthening methods in crystalline materials rely on controlling the generation,propagation,and intersection of dislocations by introducing various internal defects[1-4].
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