Silica fume, fly ash and nano-fiber mineral materials (NR powder) are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing syste...Silica fume, fly ash and nano-fiber mineral materials (NR powder) are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing systems, namely, spherical grading system and nano-fiber reinforced system were designed. Properties and interfacial microstructure of the two systems were studied according to secondary interface theory. It was shown that nano-fiber mineral materials can improve the grain grading of the admixture, increase the density of the system, improve the microstructure of the interface and the hardened paste, and enhance the uniformity of cement-based materials mixed with composite micro-grains and greatly increase their wearable rigidity and flexure strength. In this paper, two kinds of interface models, including spherical grain model and nano-fiber reinforced interface model of the cement-based materials mixed with composite micro-grains, were brought forward.展开更多
To further increase millet yield, the ideal plant in millet has become the goal of high yield breeding for millet. Taking crossbreeding or dynamic breeding technique as dominant and technologies such as modern selecti...To further increase millet yield, the ideal plant in millet has become the goal of high yield breeding for millet. Taking crossbreeding or dynamic breeding technique as dominant and technologies such as modern selection or system selection as subsidiary, progenies with ideal plant are selected by using new germplasms such as Lilvgu and Lizigu with the significant difference in plant type to other cultivars as parents. The ge- netic characteristics of new germplasms in breeding are also emphatically analyzed to summarize the breeding experience of ideal plant, which has been proved that the combination of ideal plant and heterosis utilization is one of the important ways to raise millet yield breakthrough.展开更多
With the persistent efforts of the emerging concepts as well as new types of decoration materials, modem interior design concepts usher in a new round of innovation. Facing the impact of the new innovative ideas, the ...With the persistent efforts of the emerging concepts as well as new types of decoration materials, modem interior design concepts usher in a new round of innovation. Facing the impact of the new innovative ideas, the Chinese traditional culture and art urgently need a way to combine efficient with the modern design concept.展开更多
We present a 3-D finite element (FE) approach to find the optimal distribution of seismic reinforcement force to secure high arch dam-abutment structures against certain earthquake actions. Nonlinear FE time history a...We present a 3-D finite element (FE) approach to find the optimal distribution of seismic reinforcement force to secure high arch dam-abutment structures against certain earthquake actions. Nonlinear FE time history analysis is performed on the structure to find the seismic responses, using the associated elastic-perfectly plastic material description. The concept of plastic complementary energy is introduced to structural dynamics to quantify the structure's resistance against the seismic action throughout the time history and to indicate the critical moments when extreme extents of dynamic failure occur. Meanwhile the distributions of the unbalanced force at these critical moments reveal the dominant patterns of the dynamic failure. By the principle of minimum plastic complementary energy, the unbalanced force is just the counterforce of optimal reinforcement force to secure the self-unsupportable structure against the earthquake, which makes the seismic design more targeted and effective. Seismic design analysis is performed on Maji high arch dam-abutment structure. The results could to a large extent guide the seismic design, showing that several structural surfaces lying at the upper abutment are the most seismically vulnerable. This application indicates good applicability of this approach to large-scale projects.展开更多
A two-phase elasto-plastic material is investigated. It is shown that, if the interface is modeled as the limit of a vanishing layer of a third material, then the resulting two-phase material will exhibit a smaller in...A two-phase elasto-plastic material is investigated. It is shown that, if the interface is modeled as the limit of a vanishing layer of a third material, then the resulting two-phase material will exhibit a smaller interracial dissipation than that of a pure two- phase model.展开更多
文摘Silica fume, fly ash and nano-fiber mineral materials (NR powder) are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing systems, namely, spherical grading system and nano-fiber reinforced system were designed. Properties and interfacial microstructure of the two systems were studied according to secondary interface theory. It was shown that nano-fiber mineral materials can improve the grain grading of the admixture, increase the density of the system, improve the microstructure of the interface and the hardened paste, and enhance the uniformity of cement-based materials mixed with composite micro-grains and greatly increase their wearable rigidity and flexure strength. In this paper, two kinds of interface models, including spherical grain model and nano-fiber reinforced interface model of the cement-based materials mixed with composite micro-grains, were brought forward.
基金Supported by the "Eleventh Five-Year "National Science and Tech-nology Supporting Plan(2006BAD02B02-01-02)National Modern Millet Industry System Fund~~
文摘To further increase millet yield, the ideal plant in millet has become the goal of high yield breeding for millet. Taking crossbreeding or dynamic breeding technique as dominant and technologies such as modern selection or system selection as subsidiary, progenies with ideal plant are selected by using new germplasms such as Lilvgu and Lizigu with the significant difference in plant type to other cultivars as parents. The ge- netic characteristics of new germplasms in breeding are also emphatically analyzed to summarize the breeding experience of ideal plant, which has been proved that the combination of ideal plant and heterosis utilization is one of the important ways to raise millet yield breakthrough.
文摘With the persistent efforts of the emerging concepts as well as new types of decoration materials, modem interior design concepts usher in a new round of innovation. Facing the impact of the new innovative ideas, the Chinese traditional culture and art urgently need a way to combine efficient with the modern design concept.
基金supported by China National Key Research Program (Grant No. 90715041)China National Funds for Distinguished Young Scientists (Grant No. 50925931)
文摘We present a 3-D finite element (FE) approach to find the optimal distribution of seismic reinforcement force to secure high arch dam-abutment structures against certain earthquake actions. Nonlinear FE time history analysis is performed on the structure to find the seismic responses, using the associated elastic-perfectly plastic material description. The concept of plastic complementary energy is introduced to structural dynamics to quantify the structure's resistance against the seismic action throughout the time history and to indicate the critical moments when extreme extents of dynamic failure occur. Meanwhile the distributions of the unbalanced force at these critical moments reveal the dominant patterns of the dynamic failure. By the principle of minimum plastic complementary energy, the unbalanced force is just the counterforce of optimal reinforcement force to secure the self-unsupportable structure against the earthquake, which makes the seismic design more targeted and effective. Seismic design analysis is performed on Maji high arch dam-abutment structure. The results could to a large extent guide the seismic design, showing that several structural surfaces lying at the upper abutment are the most seismically vulnerable. This application indicates good applicability of this approach to large-scale projects.
文摘A two-phase elasto-plastic material is investigated. It is shown that, if the interface is modeled as the limit of a vanishing layer of a third material, then the resulting two-phase material will exhibit a smaller interracial dissipation than that of a pure two- phase model.
