Effects of Al- Si addition on hot modulus of rup- ture ~ HMOR） . thermal shock resistance ~ TSR~ . phase composition and mierostructure of low-carbon MgO - C materials were investigated. The results show that： Al an...Effects of Al- Si addition on hot modulus of rup- ture ~ HMOR） . thermal shock resistance ~ TSR~ . phase composition and mierostructure of low-carbon MgO - C materials were investigated. The results show that： Al and Si addition to low-carbon MgO - C materials leads to dramatic increase in MOR at elevated temperatures; it increases from 4 MPa to 11 -21 MPa at 1 200 ℃ and from 2 MPa to 21 -29 MPa at 1 400 ℃. Al and Si addition to low-carbon MgO - C materials also improves TSR： residual strength ratio after thermal shock when △T = 1 200 ℃ is increased,from 44% to 73% - 77%. Al reacts with C and N2 to form, Al4C3 and AlN, Si reacts with C to form SiC. Ultimately. in-situ formed non- oxides increase appreciably with temperature rising and are well interlaced in periclase skeleton structure at 1 300 -1 400 ℃. which is beneficial to thermomechanical properties.展开更多
Four Zr–Cu–Fe–Al-based bulk metallic glasses（BMGs） with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties...Four Zr–Cu–Fe–Al-based bulk metallic glasses（BMGs） with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties, and corrosion resistance properties of the prepared BMGs were investigated. These BMGs exhibit moderate glass forming abilities along with superior fracture and yield strengths compared to previously reported Zr–Cu–Fe–Al BMGs. Specifically, the addition of Nb into this quaternary system remarkably increases the plastic strain to 27.5%, which is related to the high Poisson＇s ratio and low Young＇s and shear moduli. The Nb-bearing BMGs also exhibit a lower corrosion current density by about one order of magnitude and a wider passive region than 316 L steel in phosphate buffer solution（PBS, pH 7.4）. The combination of the optimized composition with high deformation ability, low Young＇s modulus, and excellent corrosion resistance properties indicates that this kind of BMG is promising for biomedical applications.展开更多
Overcasting is a new kind of dissimilar joining technique used to produce the aluminum（solid）/magnesium（liquid） bonding bi-metallic material in this study. For the Al/Mg（A390/AM60） bi-metallic samples, the inter...Overcasting is a new kind of dissimilar joining technique used to produce the aluminum（solid）/magnesium（liquid） bonding bi-metallic material in this study. For the Al/Mg（A390/AM60） bi-metallic samples, the interface microstructures are the research points, which directly influence the mechanical properties. It is, therefore, of vital importance to find a method to improve the interface microstructures. This research focused on the effect of the calcium（Ca） addition in the liquid Mg alloys and the heat treatment on the A390/AM60 interface microstructures of the bi-metallic samples. The testing results showed that, with Ca addition in AM60, owing to two possible reasons, the interface microstructure and the shear strength of the A390/AM60 bi-metallic samples could be improved. The heat treatment could further improve the interface microstructure and the mechanical properties by dissolving β-Mg_（17）Al_（12） into α-Mg and destroying the Mg_2Si layer structure.展开更多
An investigation was conducted to examine the impact of additive mixing with wheat straw(WS)for pellet making.This study manufactured seven types of pellets with different additive combina-tions to evaluate pellet qua...An investigation was conducted to examine the impact of additive mixing with wheat straw(WS)for pellet making.This study manufactured seven types of pellets with different additive combina-tions to evaluate pellet quality characteristics and their relationships.A laboratory-type hammer mill and a pellet mill were used for feedstock preparation and pellet production.Experimental investigations showed that the lignin content increased from 7.0%to 13.1%,which was a primary need for pelletization.Also,the heating value rose from 17.02 to 20.36 MJ/kg.However,the ash content also increased from 7.09%to 16.2%.Results showed that dimension(length and diame-ter),durability,and tensile strength increased significantly with additives while the fines content decreased.The fines content had an inverse relationship with durability and strength.Wheat straw(60%),together with 10%sawdust(SD),10%corn starch(CS),10%bentonite clay(BC),and 10%biochar(BiC),was optimal with good pellet performance(T7).In addition,both the T5 pellets(70%WS,10%SD,10%BiC,and 10%BC)and the T6 pellets(70%WS,10%SD,10%BiC,and 10%CS)provide suitable quality according to EN plus 2015 standard requirements.The ash content of produced pellet was higher than the recommended value,which suggests that further research onto the alternative additive use for ash reduction is needed.展开更多
The limitations in electronics in arithmetic, algebraic & logic processing are well known. Very high speed performance (above GHz) are not expected at all in conventional electronic mechanism. To achieve high spee...The limitations in electronics in arithmetic, algebraic & logic processing are well known. Very high speed performance (above GHz) are not expected at all in conventional electronic mechanism. To achieve high speed performance we may think on the introduction of optics instead of electronics for information, processing and computing. Non-linear optical material is a successful candidate in this regard to play a major role in the optically controlled switching systems and therefore in all-optical parallel computation these materials can show a very good potential aspect. In this paper, we have proposed a new method of an optical half adder as well as full adder circuit for binary addition using non-linear and linear optical materials.展开更多
文摘Effects of Al- Si addition on hot modulus of rup- ture ~ HMOR） . thermal shock resistance ~ TSR~ . phase composition and mierostructure of low-carbon MgO - C materials were investigated. The results show that： Al and Si addition to low-carbon MgO - C materials leads to dramatic increase in MOR at elevated temperatures; it increases from 4 MPa to 11 -21 MPa at 1 200 ℃ and from 2 MPa to 21 -29 MPa at 1 400 ℃. Al and Si addition to low-carbon MgO - C materials also improves TSR： residual strength ratio after thermal shock when △T = 1 200 ℃ is increased,from 44% to 73% - 77%. Al reacts with C and N2 to form, Al4C3 and AlN, Si reacts with C to form SiC. Ultimately. in-situ formed non- oxides increase appreciably with temperature rising and are well interlaced in periclase skeleton structure at 1 300 -1 400 ℃. which is beneficial to thermomechanical properties.
基金financially supported by the National Natural Science Foundation of China (No. 51271018)the Proprietary Program of the State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing (Nos.2011Z-01 and 2012Z-01)
文摘Four Zr–Cu–Fe–Al-based bulk metallic glasses（BMGs） with Zr contents greater than 65at% and minor additions of Nb were designed and prepared. The glass forming abilities, thermal stabilities, mechanical properties, and corrosion resistance properties of the prepared BMGs were investigated. These BMGs exhibit moderate glass forming abilities along with superior fracture and yield strengths compared to previously reported Zr–Cu–Fe–Al BMGs. Specifically, the addition of Nb into this quaternary system remarkably increases the plastic strain to 27.5%, which is related to the high Poisson＇s ratio and low Young＇s and shear moduli. The Nb-bearing BMGs also exhibit a lower corrosion current density by about one order of magnitude and a wider passive region than 316 L steel in phosphate buffer solution（PBS, pH 7.4）. The combination of the optimized composition with high deformation ability, low Young＇s modulus, and excellent corrosion resistance properties indicates that this kind of BMG is promising for biomedical applications.
基金Funded by the National Natural Science Foundation of China(No.51571080)
文摘Overcasting is a new kind of dissimilar joining technique used to produce the aluminum（solid）/magnesium（liquid） bonding bi-metallic material in this study. For the Al/Mg（A390/AM60） bi-metallic samples, the interface microstructures are the research points, which directly influence the mechanical properties. It is, therefore, of vital importance to find a method to improve the interface microstructures. This research focused on the effect of the calcium（Ca） addition in the liquid Mg alloys and the heat treatment on the A390/AM60 interface microstructures of the bi-metallic samples. The testing results showed that, with Ca addition in AM60, owing to two possible reasons, the interface microstructure and the shear strength of the A390/AM60 bi-metallic samples could be improved. The heat treatment could further improve the interface microstructure and the mechanical properties by dissolving β-Mg_（17）Al_（12） into α-Mg and destroying the Mg_2Si layer structure.
文摘An investigation was conducted to examine the impact of additive mixing with wheat straw(WS)for pellet making.This study manufactured seven types of pellets with different additive combina-tions to evaluate pellet quality characteristics and their relationships.A laboratory-type hammer mill and a pellet mill were used for feedstock preparation and pellet production.Experimental investigations showed that the lignin content increased from 7.0%to 13.1%,which was a primary need for pelletization.Also,the heating value rose from 17.02 to 20.36 MJ/kg.However,the ash content also increased from 7.09%to 16.2%.Results showed that dimension(length and diame-ter),durability,and tensile strength increased significantly with additives while the fines content decreased.The fines content had an inverse relationship with durability and strength.Wheat straw(60%),together with 10%sawdust(SD),10%corn starch(CS),10%bentonite clay(BC),and 10%biochar(BiC),was optimal with good pellet performance(T7).In addition,both the T5 pellets(70%WS,10%SD,10%BiC,and 10%BC)and the T6 pellets(70%WS,10%SD,10%BiC,and 10%CS)provide suitable quality according to EN plus 2015 standard requirements.The ash content of produced pellet was higher than the recommended value,which suggests that further research onto the alternative additive use for ash reduction is needed.
文摘The limitations in electronics in arithmetic, algebraic & logic processing are well known. Very high speed performance (above GHz) are not expected at all in conventional electronic mechanism. To achieve high speed performance we may think on the introduction of optics instead of electronics for information, processing and computing. Non-linear optical material is a successful candidate in this regard to play a major role in the optically controlled switching systems and therefore in all-optical parallel computation these materials can show a very good potential aspect. In this paper, we have proposed a new method of an optical half adder as well as full adder circuit for binary addition using non-linear and linear optical materials.
