The construction of beautiful and livable villages is one of the important tasks of ruralrevitalization in the new era, and the development of rural areas attaches more and more importanceto the improvement of human s...The construction of beautiful and livable villages is one of the important tasks of ruralrevitalization in the new era, and the development of rural areas attaches more and more importanceto the improvement of human settlement environment. By investigating the construction status andexisting problems of Zhaoba Village in Nanjing, it tries to take “beauty” and “livability” as the planningrequirements. The village positioning is planned accurately, and the functional layout is carried outreasonably. According to the characteristic industries, landscape features and infrastructure of ZhaobaVillage, humanized construction strategies are put forward, thus improving the quality of human settlementenvironment in Zhaoba Village.展开更多
Rooftop greening not only has ecological benefits such as energy savings, water conservation and air quality improvement but also has aesthetic and social benefits, especially for the rooftops of commercial complexes,...Rooftop greening not only has ecological benefits such as energy savings, water conservation and air quality improvement but also has aesthetic and social benefits, especially for the rooftops of commercial complexes, which should meet people’s demand for beauty while satisfying sustainable urban development. In this paper, 80 samples of ten commercial rooftops in five old urban areas of Chengdu, China, were selected as the research objects, and the beauty values of different roof types and different plant community types were quantified by the aesthetic evaluation method, and the factors influencing the beauty values were investigated. The results showed that the highest average SBE value was for plant ornamental roofs (0.635), followed by recreational roofs (0.080), and the lowest average SBE value was for sports and fitness (-0.555);Mixed needle-broad communities had the greatest average SBE value (0.330), followed by mixed bamboo-broad communities (0.094), while pure bamboo forests had the lowest average SBE value (-0.716). The rooftop plant community’s aesthetic value was highly significant and correlated positively with the type of roof, the community’s growth type, its vertical structure, and the number of plants in the community.展开更多
In January 2023,the author was invited to carry out a series of online lecture courses titled"Where to Find Beauty:Exploring the Beauty of Chinese Opera"for Malaysian Chinese.The four lectures were hosted by...In January 2023,the author was invited to carry out a series of online lecture courses titled"Where to Find Beauty:Exploring the Beauty of Chinese Opera"for Malaysian Chinese.The four lectures were hosted by China Cultural Center in Kuala Lumpur and the Network of International Cultural Entities,and organized by Beijing Liantong Wuzhou Culture&Tourism Co.,Ltd.and the Malaysian Belt and Road Committee.展开更多
Romance of the Three Kingdoms has once been greatly admired by a large number of people. And now, beauty makeup in China is also in the process of the Killers of the Three Kingdoms.Represented by Guangzhou, beauty mak...Romance of the Three Kingdoms has once been greatly admired by a large number of people. And now, beauty makeup in China is also in the process of the Killers of the Three Kingdoms.Represented by Guangzhou, beauty makeup in the Greater Bay Area has become the industrial cluster with the largest scale and the most complete category in China after decades of development, just like “Cao Wei”, the most powerful country in the Three Kingdoms.展开更多
The way in which international beauty giants are laying out the Chinese market seems to be quietly changing.I have recently observed that the pace of foreign beauty giants launching self-developed patented ingredients...The way in which international beauty giants are laying out the Chinese market seems to be quietly changing.I have recently observed that the pace of foreign beauty giants launching self-developed patented ingredients and technologies is accelerating.In particular,a number of relevant achievements have been focused on the November 2023 China International Import Expo.Among them,new patented ingredients/technologies launched in the past year accounted for six cases.They include Shiseido’s Neomyone,Unilever’s Glutathione meta-technology,Amore Pacific's Fonoin,Estee Lauder's Sertiin Age Reversal Technology,Kose’s IPS cell research technology,and Procter&Gamble’s OLAY’s“Collagen Visualization”technology,etc..展开更多
Longquan celadon is deeply meaningful in history and possesses multiple attributes including aesthetics,practicality,science,and cultural exchange,offering unique advantages in empowering traditional cultural dissemin...Longquan celadon is deeply meaningful in history and possesses multiple attributes including aesthetics,practicality,science,and cultural exchange,offering unique advantages in empowering traditional cultural dissemination and connecting modern beautiful lives.展开更多
For more than 60 years,Mr.Xu Yuanchong has been devoted to education.He has not only made remarkable achievements in translating from and into Chinese,English,French and other languages,but has also developed his own ...For more than 60 years,Mr.Xu Yuanchong has been devoted to education.He has not only made remarkable achievements in translating from and into Chinese,English,French and other languages,but has also developed his own unique concept of translation.Since 1950,he has always adhered to the“Three Beauties Theory”,believing that translation should not only rely on the original text,but also realize the“beauty of meaning”,“beauty of sound”,and“beauty of form”.Based on Xu Yuanchong’s“Three Beauties Theory”,this paper takes Zheng Zhenduo’s and Feng Tang’s Chinese translations of Stray Birds as an example to explore in depth the specifics of poetry translation theory.The study summarizes the similarities and differences between these two translations in embodying the“three beauties”,providing insights into the Chinese translation techniques of philosophical prose poems.This endeavor seeks to offer valuable insights for the comparative study of Stray Birds translations。展开更多
The solvent debinding of water soluble binder in powder injection moulding (MIM) was investigated systematically, including the effects of solvent types, temperature and the thickness of green parts on the solvent deb...The solvent debinding of water soluble binder in powder injection moulding (MIM) was investigated systematically, including the effects of solvent types, temperature and the thickness of green parts on the solvent debinding rate. After studying the debinding of a green part with a thickness of 4.26 mm, it was found that, the debinding rate of polyethylene glycol(PEG) in water and alcohol was high initially, and then decreased; however, it would increase with temperature increasing. At room temperature, the dissolution rate of PEG in water was higher than that in alcohol, but the latter would be much faster with temperature increasing because the debinding activation energy in alcohol was 51.44 kJ·mol -1 ·K -1 , much higher than 24.23 kJ·mol -1 ·K -1 in water. With a green part thickness larger than 4.26 mm, the debinding was controlled by diffusion; but with that smaller than 2.36 mm, the debinding was controlled by both dissolution and diffusion.展开更多
Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, ...Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.展开更多
Failure of rock mass that is subjected to compressive loads occurs from initiation, propagation, and linkage of new cracks from preexisting fissures. Our research investigates the cracking behaviour and coalescence pr...Failure of rock mass that is subjected to compressive loads occurs from initiation, propagation, and linkage of new cracks from preexisting fissures. Our research investigates the cracking behaviour and coalescence process in a brittle material with two non-parallel overlapping flaws using a high-speed camera. The coalescence tensile crack and tensile wing cracks were the first cracks to occur from the preexisting flaws. The initiation stresses of the primary cracks at the two tips of each flaw were simultaneous and decreased with reduced flaw inclination angle. The following types of coalescence cracks were identified between the flaws: primary tensile coalescence crack, tensile crack linkage, shear crack linkage, mixed tensile-shear crack, and indirect crack coalescence. Coalescence through tensile linkage occurred mostly at pre-peak stress. In contrast, coalescence through shear or mixed tensile-shear cracks occurred at higher stress.Overall, this study indicates that the geometry of preexisting flaws affect crack initiation and coalescence behaviour.展开更多
Coupling the quasi 3D numerical simulation of electromagnetic field and the experiments with some metals such as tin, aluminum, copper and steel, the electromagnetic characteristics of continuous casting with soft con...Coupling the quasi 3D numerical simulation of electromagnetic field and the experiments with some metals such as tin, aluminum, copper and steel, the electromagnetic characteristics of continuous casting with soft contacted mould, especially the influences of power frequency, the mould structure, and the inductor position, size and current on the electromagnetic force and pressure on the billet, were analyzed. The result shows that, in continuous casting with soft contacted mould, the electromagnetic pressure on the surface of billet increases with the rising of the power frequency as a logarithmically parabolic function and, with that of inductor current as a parabolic function. The design principle of the soft contacted mould is that 1) the mould structure should be ‘more segments and thin slits’; 2) the topside of inductor should be at the same location with the meniscus of molten metal; 3) the inductor should cover the initial solidifying shell of billet.展开更多
The finite element analysis and the optimum design of aluminum profile extrusion mould were investigated using the ANSYS software and its parameterized modeling method. The optimum dimensions of the mould were obtaine...The finite element analysis and the optimum design of aluminum profile extrusion mould were investigated using the ANSYS software and its parameterized modeling method. The optimum dimensions of the mould were obtained. It is found that the stress distribution is very uneven, and the stress convergence is rather severe in the bridge of the aluminum profile extrusion mould. The optimum height of the mould is 70.527 mm, and the optimum radius of dividing holes are 70.182 mm and 80.663 mm. Increasing the height of the mould in the range of 61.282 mm to 70.422 mm can prolong its longevity, but when the height is over 70.422 mm, its longevity reduces.展开更多
The paper presents the research results of using an innovative method to reclaim the waste moulding sands containing water glass. Two of the examined processes are connected with "dry" or "wet" act...The paper presents the research results of using an innovative method to reclaim the waste moulding sands containing water glass. Two of the examined processes are connected with "dry" or "wet" activation of inorganic binder in waste moulding sand mixtures physically hardened by microwave radiation. The sand mixtures consisting of high-silica sand and water-glass with average molar module 2.5, were subjected to the following cyclical process: mixing the components, compacting, microwave heating, cooling-down, thermally loading the mould to 800 °C, cooling-down to ambient temperature, and knocking-out. After being knocked-out, the waste moulding sands were subjected to either dry or wet activation of the binder. To activate thermally treated inorganic binder, each of the examined processes employed the surface phenomenon usually associated to mechanical reclamation. The study also covered possible use of some elements of wet reclamation to rehydrate waste binder. To evaluate the effectiveness of the two proposed methods of waste binder activation, selected strength and technological parameters were measured. After each subsequent processing cycle, the permeability, tensile strength and bending strength were determined. In addition, the surface of activated sand grains was examined with a scanning electron microscope. Analysis of the results indicates that it is possible to re-activate the used binder such as sodium silicate, and to stabilize the strength parameters in both activation processes. Permeability of the refreshed moulding sands strongly depends on the surface condition of high-silica grains. The wet activation process by wetting and buffering knocked-out moulding sands in closed humid environment makes it possible to reduce the content of refreshing additive in water-glass. The moulding sands cyclically prepared in both processes do not require the addition of fresh high-silica sand. The relatively high quality achieved in the refreshed moulding sands allows them to be reused for manufacture of next moulds. Thus, the two proposed methods for cyclically processing used moulding sands containing sodium silicate, subject to microwave hardening, are suitable for economic and ecological circulation moulding mixtures.展开更多
The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botryt...The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was more affected in vitro by low concentrations of the fungicides tested above 0.4 μg·ml-1 than the bioagent T. harzianum (Jn14). The later was almost insensitive to pyrimethanil. In the same direction, gray mould disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, compared to the control, while the application of T. harzianum (Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, compared to the control. In the integrated control approach, the combination of T. harzianum (Jn14) with higher concentrations of the tested fungicides (ED50) completely inhibited strawberry gray mould disease severity in pots and the greenhouse.展开更多
Digital patternless freeze-casting technology is a new approach for obtaining frozen sand moulds using digital milling technology. The change law of tensile strength and air permeability of frozen sand moulds (100-mes...Digital patternless freeze-casting technology is a new approach for obtaining frozen sand moulds using digital milling technology. The change law of tensile strength and air permeability of frozen sand moulds (100-mesh and 200-mesh silica sand, and zircon sand moulds) under different freezing temperatures and water contents was studied. Results show that with the decrease of freezing temperature and the increase of water contents, the tensile strength and air permeability of the sand moulds are gradually improved. Meanwhile, computed tomography technology was used to characterize the shape and size of the water film between the sand particles mixed with 4wt.% water. The results show that in silica sand moulds, the form of water film is lumpy, and 200-mesh silica sand moulds have more water films and higher proportion of small-sized water films than 100-mesh silica sand moulds, while in zircon sand moulds, the form of water film is membranous. At the same freezing temperature and water content, the tensile strength of zircon sand mould is the highest, and 100-mesh silica sand mould is the lowest. A comparative solidification experiment of A356 aluminum alloy was carried out in frozen sand mould and resin sand mould. The results show that the primary α-Al phase appears in the form of equiaxed and eutectic silicon phase is needle-like in freezing sand mould casting, but the primary α-Al phase grows in the form of dendrites, and the eutectic silicon phase is coarse needle-like in the resin sand mould casting. The difference of microstructure is caused by the different cooling rate. The cooling rate of A356 aluminum alloy in frozen sand mould is higher than that in resin sand mould.展开更多
This study proposes an innovative precast shear wall system, called an EVE precast hollow shear wall structure (EVE-PHSW). Precast panels in EVE-PHSW are simultaneously precast with vertical and horizontal holes. Nonc...This study proposes an innovative precast shear wall system, called an EVE precast hollow shear wall structure (EVE-PHSW). Precast panels in EVE-PHSW are simultaneously precast with vertical and horizontal holes. Noncontact lap splices of rebars are used in vertical joints connecting adjacent precast panels for automated prefabrication and easy in situ erection. The seismic behavior of EVE walls was examined through a series of tests on six wall specimens with aspect ratios of 1.0~1.3. Test results showed that EVE wall specimens with inside cast-in situ concrete achieved the desired “strong bending and weak shear” and failed in shear mode. Common main diagonal cracks and brittle shear failure in squat cast-in situ walls were prevented. Inside cast-in situ concrete could signifi cantly improve the shear strength and stiff ness of EVE walls. The details of boundary elements (cast-in situ or prefabricated) and vertical joints (contiguous or spaced) had little eff ect on the global behavior of EVE walls. Noncontact lap splices in vertical joints could enable EVE walls to exhibit stable load-carrying capacity through extensive deformations. Evaluation on design codes revealed that both JGJ 3-2010 and ACI 318-14 provide conservative estimation of shear strength of EVE walls, and EVE walls achieved shear strength reserves comparative to cast-in situ walls. The recommended eff ective stiff ness for cast-in situ walls in ASCE 41-17 appeared to be appropriate for EVE walls.展开更多
The study on the fluid flow, meniscus oscillation, slag entrapment in continuous casting mould was conducted mathematically and experimentally. The results show that the injection of argon into submerged nozzle enhanc...The study on the fluid flow, meniscus oscillation, slag entrapment in continuous casting mould was conducted mathematically and experimentally. The results show that the injection of argon into submerged nozzle enhances the meniscus oscillation, thus increases the probability of slag entrapment, and the critical argon blowing flow rate, which will give rise to slag entrapment, is around 10l/min. The trajectory of bubble is affected by the bubble diameter and the molten steel flow, and the bubble diameter is dominant. The bubble with diameter 1.4mm floats fastest with 0.47m/s terminal velocity.展开更多
The relative performance of coatings for furan resin sand moulds [P-toluol sulphonic acid(PTSA) as hardener] [FRS-PTSA moulds], was compared by analyzing the surface layer for degenerated graphite in Mg treated iron w...The relative performance of coatings for furan resin sand moulds [P-toluol sulphonic acid(PTSA) as hardener] [FRS-PTSA moulds], was compared by analyzing the surface layer for degenerated graphite in Mg treated iron with 0.020 wt.% to 0.054 wt.% Mgres. It was found that the iron nodularising potential(Mg, Ce, La content) and whether the mould coatings contained S, or were capable of desulphurizing were important factors. These moulds have S in the PTSA binder, which aggravates graphite degeneration in the surface layer, depending strongly on the Mgres with lower Mgres increasing the layer thickness. The application of a mould coating strongly influenced graphite deterioration in the surface layer of castings. It either promoted graphite degeneration to less compact morphologies when using S-bearing coatings, or conversely, limited the surface layer thickness using desulphurization type coatings. Independently of the S-source at the metal – mould interface, the presence of sulphur had an adverse effect on graphite quality at the surface of Mg-treated irons, but its negative effect could also reach the graphite phase within the casting section. If the coatings employed desulphurization materials, such as Mg O, or a mixture(Ca O + Mg O + Talc) or Mgbearing Fe Si, they protected the graphite shape, improving graphite nodularity, at the metal – mould interface, and so decreased the average layer thickness in FRS-PTSA moulds. Fe Si Mg was highly efficient in minimizing the casting skin by improving graphite nodularity. It is presumed that the Mg O or(Mg O + Ca O + Talc) based coatings acted to remove any S released by the mould media. The Mg-Fe Si coatings also reacted with S from the mould but additionally supplemented the Mg nodularising potential prior to solidification. This dual activity is achievable with coatings containing active magnesium derived from fine Mg-Fe Si materials.展开更多
In this paper, coupling the quasi-3D numerical simulation of electromagnetic field and the experiments of continuous casting with soft-contacted mould with some metals such as tin, aluminum, copper and steel, the elec...In this paper, coupling the quasi-3D numerical simulation of electromagnetic field and the experiments of continuous casting with soft-contacted mould with some metals such as tin, aluminum, copper and steel, the electromagnetic characteristics of continuous casting with soft-contacted mould is analyzed. It is shown that the electromagnetic pressure on the surface of billet is increasing with the rising of power frequency as a logarithmically parabolic function, with that of electric conductivity of billet as a power junction, and with that of the current in inductor as a parabolic junction.展开更多
文摘The construction of beautiful and livable villages is one of the important tasks of ruralrevitalization in the new era, and the development of rural areas attaches more and more importanceto the improvement of human settlement environment. By investigating the construction status andexisting problems of Zhaoba Village in Nanjing, it tries to take “beauty” and “livability” as the planningrequirements. The village positioning is planned accurately, and the functional layout is carried outreasonably. According to the characteristic industries, landscape features and infrastructure of ZhaobaVillage, humanized construction strategies are put forward, thus improving the quality of human settlementenvironment in Zhaoba Village.
文摘Rooftop greening not only has ecological benefits such as energy savings, water conservation and air quality improvement but also has aesthetic and social benefits, especially for the rooftops of commercial complexes, which should meet people’s demand for beauty while satisfying sustainable urban development. In this paper, 80 samples of ten commercial rooftops in five old urban areas of Chengdu, China, were selected as the research objects, and the beauty values of different roof types and different plant community types were quantified by the aesthetic evaluation method, and the factors influencing the beauty values were investigated. The results showed that the highest average SBE value was for plant ornamental roofs (0.635), followed by recreational roofs (0.080), and the lowest average SBE value was for sports and fitness (-0.555);Mixed needle-broad communities had the greatest average SBE value (0.330), followed by mixed bamboo-broad communities (0.094), while pure bamboo forests had the lowest average SBE value (-0.716). The rooftop plant community’s aesthetic value was highly significant and correlated positively with the type of roof, the community’s growth type, its vertical structure, and the number of plants in the community.
文摘In January 2023,the author was invited to carry out a series of online lecture courses titled"Where to Find Beauty:Exploring the Beauty of Chinese Opera"for Malaysian Chinese.The four lectures were hosted by China Cultural Center in Kuala Lumpur and the Network of International Cultural Entities,and organized by Beijing Liantong Wuzhou Culture&Tourism Co.,Ltd.and the Malaysian Belt and Road Committee.
文摘Romance of the Three Kingdoms has once been greatly admired by a large number of people. And now, beauty makeup in China is also in the process of the Killers of the Three Kingdoms.Represented by Guangzhou, beauty makeup in the Greater Bay Area has become the industrial cluster with the largest scale and the most complete category in China after decades of development, just like “Cao Wei”, the most powerful country in the Three Kingdoms.
文摘The way in which international beauty giants are laying out the Chinese market seems to be quietly changing.I have recently observed that the pace of foreign beauty giants launching self-developed patented ingredients and technologies is accelerating.In particular,a number of relevant achievements have been focused on the November 2023 China International Import Expo.Among them,new patented ingredients/technologies launched in the past year accounted for six cases.They include Shiseido’s Neomyone,Unilever’s Glutathione meta-technology,Amore Pacific's Fonoin,Estee Lauder's Sertiin Age Reversal Technology,Kose’s IPS cell research technology,and Procter&Gamble’s OLAY’s“Collagen Visualization”technology,etc..
文摘Longquan celadon is deeply meaningful in history and possesses multiple attributes including aesthetics,practicality,science,and cultural exchange,offering unique advantages in empowering traditional cultural dissemination and connecting modern beautiful lives.
文摘For more than 60 years,Mr.Xu Yuanchong has been devoted to education.He has not only made remarkable achievements in translating from and into Chinese,English,French and other languages,but has also developed his own unique concept of translation.Since 1950,he has always adhered to the“Three Beauties Theory”,believing that translation should not only rely on the original text,but also realize the“beauty of meaning”,“beauty of sound”,and“beauty of form”.Based on Xu Yuanchong’s“Three Beauties Theory”,this paper takes Zheng Zhenduo’s and Feng Tang’s Chinese translations of Stray Birds as an example to explore in depth the specifics of poetry translation theory.The study summarizes the similarities and differences between these two translations in embodying the“three beauties”,providing insights into the Chinese translation techniques of philosophical prose poems.This endeavor seeks to offer valuable insights for the comparative study of Stray Birds translations。
文摘The solvent debinding of water soluble binder in powder injection moulding (MIM) was investigated systematically, including the effects of solvent types, temperature and the thickness of green parts on the solvent debinding rate. After studying the debinding of a green part with a thickness of 4.26 mm, it was found that, the debinding rate of polyethylene glycol(PEG) in water and alcohol was high initially, and then decreased; however, it would increase with temperature increasing. At room temperature, the dissolution rate of PEG in water was higher than that in alcohol, but the latter would be much faster with temperature increasing because the debinding activation energy in alcohol was 51.44 kJ·mol -1 ·K -1 , much higher than 24.23 kJ·mol -1 ·K -1 in water. With a green part thickness larger than 4.26 mm, the debinding was controlled by diffusion; but with that smaller than 2.36 mm, the debinding was controlled by both dissolution and diffusion.
文摘Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.
基金supported by the National Natural Science Foundation of China (Grants 41572310, 41272351)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grants XDB10030301, XDB10030304)support provided by the CAS-TWAS Presidential Fellowship, University of Chinese Academy of Sciences, Beijing, China
文摘Failure of rock mass that is subjected to compressive loads occurs from initiation, propagation, and linkage of new cracks from preexisting fissures. Our research investigates the cracking behaviour and coalescence process in a brittle material with two non-parallel overlapping flaws using a high-speed camera. The coalescence tensile crack and tensile wing cracks were the first cracks to occur from the preexisting flaws. The initiation stresses of the primary cracks at the two tips of each flaw were simultaneous and decreased with reduced flaw inclination angle. The following types of coalescence cracks were identified between the flaws: primary tensile coalescence crack, tensile crack linkage, shear crack linkage, mixed tensile-shear crack, and indirect crack coalescence. Coalescence through tensile linkage occurred mostly at pre-peak stress. In contrast, coalescence through shear or mixed tensile-shear cracks occurred at higher stress.Overall, this study indicates that the geometry of preexisting flaws affect crack initiation and coalescence behaviour.
文摘Coupling the quasi 3D numerical simulation of electromagnetic field and the experiments with some metals such as tin, aluminum, copper and steel, the electromagnetic characteristics of continuous casting with soft contacted mould, especially the influences of power frequency, the mould structure, and the inductor position, size and current on the electromagnetic force and pressure on the billet, were analyzed. The result shows that, in continuous casting with soft contacted mould, the electromagnetic pressure on the surface of billet increases with the rising of the power frequency as a logarithmically parabolic function and, with that of inductor current as a parabolic function. The design principle of the soft contacted mould is that 1) the mould structure should be ‘more segments and thin slits’; 2) the topside of inductor should be at the same location with the meniscus of molten metal; 3) the inductor should cover the initial solidifying shell of billet.
文摘The finite element analysis and the optimum design of aluminum profile extrusion mould were investigated using the ANSYS software and its parameterized modeling method. The optimum dimensions of the mould were obtained. It is found that the stress distribution is very uneven, and the stress convergence is rather severe in the bridge of the aluminum profile extrusion mould. The optimum height of the mould is 70.527 mm, and the optimum radius of dividing holes are 70.182 mm and 80.663 mm. Increasing the height of the mould in the range of 61.282 mm to 70.422 mm can prolong its longevity, but when the height is over 70.422 mm, its longevity reduces.
基金co-financed by the European Union within the European Social Fund in the project"Mloda Kadra 2015+"
文摘The paper presents the research results of using an innovative method to reclaim the waste moulding sands containing water glass. Two of the examined processes are connected with "dry" or "wet" activation of inorganic binder in waste moulding sand mixtures physically hardened by microwave radiation. The sand mixtures consisting of high-silica sand and water-glass with average molar module 2.5, were subjected to the following cyclical process: mixing the components, compacting, microwave heating, cooling-down, thermally loading the mould to 800 °C, cooling-down to ambient temperature, and knocking-out. After being knocked-out, the waste moulding sands were subjected to either dry or wet activation of the binder. To activate thermally treated inorganic binder, each of the examined processes employed the surface phenomenon usually associated to mechanical reclamation. The study also covered possible use of some elements of wet reclamation to rehydrate waste binder. To evaluate the effectiveness of the two proposed methods of waste binder activation, selected strength and technological parameters were measured. After each subsequent processing cycle, the permeability, tensile strength and bending strength were determined. In addition, the surface of activated sand grains was examined with a scanning electron microscope. Analysis of the results indicates that it is possible to re-activate the used binder such as sodium silicate, and to stabilize the strength parameters in both activation processes. Permeability of the refreshed moulding sands strongly depends on the surface condition of high-silica grains. The wet activation process by wetting and buffering knocked-out moulding sands in closed humid environment makes it possible to reduce the content of refreshing additive in water-glass. The moulding sands cyclically prepared in both processes do not require the addition of fresh high-silica sand. The relatively high quality achieved in the refreshed moulding sands allows them to be reused for manufacture of next moulds. Thus, the two proposed methods for cyclically processing used moulding sands containing sodium silicate, subject to microwave hardening, are suitable for economic and ecological circulation moulding mixtures.
文摘The effects of biofungicide formula containing the biocontrol agent Trichoderma harzianum (Jn14) as wettable powder in combination with the fungicides pyrimethanil and a mixture of cyprodinil and flydioxonil on Botrytis cinerea of strawberry in vitro, in vivo and in greenhouse were studied. The pathogen B. cinerea was more affected in vitro by low concentrations of the fungicides tested above 0.4 μg·ml-1 than the bioagent T. harzianum (Jn14). The later was almost insensitive to pyrimethanil. In the same direction, gray mould disease severity on strawberry detached leaves and whole plants was reduced up to 89% by the tested fungicides, compared to the control, while the application of T. harzianum (Jn14) alone reduced disease severity up to 45% on strawberry detached leaves, compared to the control. In the integrated control approach, the combination of T. harzianum (Jn14) with higher concentrations of the tested fungicides (ED50) completely inhibited strawberry gray mould disease severity in pots and the greenhouse.
基金This work was financially supported by the National Science Found for Distinguished Young Scholars(No.51525503).
文摘Digital patternless freeze-casting technology is a new approach for obtaining frozen sand moulds using digital milling technology. The change law of tensile strength and air permeability of frozen sand moulds (100-mesh and 200-mesh silica sand, and zircon sand moulds) under different freezing temperatures and water contents was studied. Results show that with the decrease of freezing temperature and the increase of water contents, the tensile strength and air permeability of the sand moulds are gradually improved. Meanwhile, computed tomography technology was used to characterize the shape and size of the water film between the sand particles mixed with 4wt.% water. The results show that in silica sand moulds, the form of water film is lumpy, and 200-mesh silica sand moulds have more water films and higher proportion of small-sized water films than 100-mesh silica sand moulds, while in zircon sand moulds, the form of water film is membranous. At the same freezing temperature and water content, the tensile strength of zircon sand mould is the highest, and 100-mesh silica sand mould is the lowest. A comparative solidification experiment of A356 aluminum alloy was carried out in frozen sand mould and resin sand mould. The results show that the primary α-Al phase appears in the form of equiaxed and eutectic silicon phase is needle-like in freezing sand mould casting, but the primary α-Al phase grows in the form of dendrites, and the eutectic silicon phase is coarse needle-like in the resin sand mould casting. The difference of microstructure is caused by the different cooling rate. The cooling rate of A356 aluminum alloy in frozen sand mould is higher than that in resin sand mould.
基金Beijing Everest Green Building Technology Ltd. for the funding
文摘This study proposes an innovative precast shear wall system, called an EVE precast hollow shear wall structure (EVE-PHSW). Precast panels in EVE-PHSW are simultaneously precast with vertical and horizontal holes. Noncontact lap splices of rebars are used in vertical joints connecting adjacent precast panels for automated prefabrication and easy in situ erection. The seismic behavior of EVE walls was examined through a series of tests on six wall specimens with aspect ratios of 1.0~1.3. Test results showed that EVE wall specimens with inside cast-in situ concrete achieved the desired “strong bending and weak shear” and failed in shear mode. Common main diagonal cracks and brittle shear failure in squat cast-in situ walls were prevented. Inside cast-in situ concrete could signifi cantly improve the shear strength and stiff ness of EVE walls. The details of boundary elements (cast-in situ or prefabricated) and vertical joints (contiguous or spaced) had little eff ect on the global behavior of EVE walls. Noncontact lap splices in vertical joints could enable EVE walls to exhibit stable load-carrying capacity through extensive deformations. Evaluation on design codes revealed that both JGJ 3-2010 and ACI 318-14 provide conservative estimation of shear strength of EVE walls, and EVE walls achieved shear strength reserves comparative to cast-in situ walls. The recommended eff ective stiff ness for cast-in situ walls in ASCE 41-17 appeared to be appropriate for EVE walls.
文摘The study on the fluid flow, meniscus oscillation, slag entrapment in continuous casting mould was conducted mathematically and experimentally. The results show that the injection of argon into submerged nozzle enhances the meniscus oscillation, thus increases the probability of slag entrapment, and the critical argon blowing flow rate, which will give rise to slag entrapment, is around 10l/min. The trajectory of bubble is affected by the bubble diameter and the molten steel flow, and the bubble diameter is dominant. The bubble with diameter 1.4mm floats fastest with 0.47m/s terminal velocity.
基金funded by the Sectoral Operational Programme Human Resources Development 2007-2013 of the Romanian Ministry of Labour,Family and Social Protection through the Financial Agreement POSDRU/6/1.5/S/19
文摘The relative performance of coatings for furan resin sand moulds [P-toluol sulphonic acid(PTSA) as hardener] [FRS-PTSA moulds], was compared by analyzing the surface layer for degenerated graphite in Mg treated iron with 0.020 wt.% to 0.054 wt.% Mgres. It was found that the iron nodularising potential(Mg, Ce, La content) and whether the mould coatings contained S, or were capable of desulphurizing were important factors. These moulds have S in the PTSA binder, which aggravates graphite degeneration in the surface layer, depending strongly on the Mgres with lower Mgres increasing the layer thickness. The application of a mould coating strongly influenced graphite deterioration in the surface layer of castings. It either promoted graphite degeneration to less compact morphologies when using S-bearing coatings, or conversely, limited the surface layer thickness using desulphurization type coatings. Independently of the S-source at the metal – mould interface, the presence of sulphur had an adverse effect on graphite quality at the surface of Mg-treated irons, but its negative effect could also reach the graphite phase within the casting section. If the coatings employed desulphurization materials, such as Mg O, or a mixture(Ca O + Mg O + Talc) or Mgbearing Fe Si, they protected the graphite shape, improving graphite nodularity, at the metal – mould interface, and so decreased the average layer thickness in FRS-PTSA moulds. Fe Si Mg was highly efficient in minimizing the casting skin by improving graphite nodularity. It is presumed that the Mg O or(Mg O + Ca O + Talc) based coatings acted to remove any S released by the mould media. The Mg-Fe Si coatings also reacted with S from the mould but additionally supplemented the Mg nodularising potential prior to solidification. This dual activity is achievable with coatings containing active magnesium derived from fine Mg-Fe Si materials.
文摘In this paper, coupling the quasi-3D numerical simulation of electromagnetic field and the experiments of continuous casting with soft-contacted mould with some metals such as tin, aluminum, copper and steel, the electromagnetic characteristics of continuous casting with soft-contacted mould is analyzed. It is shown that the electromagnetic pressure on the surface of billet is increasing with the rising of power frequency as a logarithmically parabolic function, with that of electric conductivity of billet as a power junction, and with that of the current in inductor as a parabolic junction.
