The effect of the borax content and magnesia to phosphate ratio(M/P) on the hydration properties of the magnesium potassium phosphate cement(MKPC) with large volume of fly ash was investigated, and a five-hydratio...The effect of the borax content and magnesia to phosphate ratio(M/P) on the hydration properties of the magnesium potassium phosphate cement(MKPC) with large volume of fly ash was investigated, and a five-hydration-stage for MKPCs was proposed. The results show that MKPC sets rapidly with less than 8% of borax, which is unfavorable to the application of MKPC on construction. Adding more than 8%(including 8%) of borax results in a secondary hydration peak for MKPC, in which the process of hydration can be divided into five stages, namely, pre-induction period, induction period, acceleration period, deceleration period and stable period. M/P ratios could not change the multi-step reactive stages but higher M/P ratios could accelerate the hydration. Borax tends to impact the formation of Mg-containing hydrated products.展开更多
For analyzing the effects of forest litter and slope aspect on soil properties eight soil samples were collected at a depth of 0–10 cm near(i.e.,beneath the crown)and away from(i.e.,not influenced by crown)five Persi...For analyzing the effects of forest litter and slope aspect on soil properties eight soil samples were collected at a depth of 0–10 cm near(i.e.,beneath the crown)and away from(i.e.,not influenced by crown)five Persian turpentine trees each on a north and a south slope at the same elevation in a Zagros forest,Iran.The litter beneath tree crowns and slope exposure were found to have significant interactive effects on C,N,P,K,and electrical conductivity of the soils,however,Ca,Mg and the soil pH were not significantly influenced by these factors.The soil beneath the crowns was enriched in cations compared to more distal positions.Generally,Persian turpentine trees have positive impacts on soil properties in the forest.Degrading or killing these trees by sap extraction,extreme grazing,cutting,fire and expansion of agriculture will lead to significant losses in soil fertility and increases in soil erosion.展开更多
Some characterizations of preregular operators between two Banach lattices are presented. Then several sufficient conditions for preregular operators being regular are given, and some related results are also obtained.
We focus on two new 21) materials, i.e., monolayer and bilayer silicon phosphides (Sil P1). Based on the elastic- scattering Green's function, the electronic-transport properties of two-dimensional monolayer and b...We focus on two new 21) materials, i.e., monolayer and bilayer silicon phosphides (Sil P1). Based on the elastic- scattering Green's function, the electronic-transport properties of two-dimensional monolayer and bilayer Au- Si1P1-Au molecular junctions are studied. It is found that their bandgaps are narrow (0.16eV for a monolayer molecular junction and 0.26 e V for a bilayer molecular junction). Moreover, the calculated current-voltage char- acteristics indicate that the monolayer molecular junction provides constant output current (20 hA) over a wide voltage range, and the bilayer molecular junction provides higher current (42 hA).展开更多
Let P be an arbitrary property of rings and homomorphically closed. For an arbitrary ring A we construct quasi P radical QP(A) with transfinite induction, and give another characterization of quasi ...Let P be an arbitrary property of rings and homomorphically closed. For an arbitrary ring A we construct quasi P radical QP(A) with transfinite induction, and give another characterization of quasi P radical: QP(A)=∩{I α|I α is an ideal of A, and A/I α contains no non zero P ideal }.展开更多
The notion of a p-convergent operator on a Banach space was originally introduced in 1993 by Castillo and SAnehez in the paper entitled "Dunford-Pettis-like properties of continuous vector function spaces". In the p...The notion of a p-convergent operator on a Banach space was originally introduced in 1993 by Castillo and SAnehez in the paper entitled "Dunford-Pettis-like properties of continuous vector function spaces". In the present paper we consider the p-convergent operators on Banach lattices, prove some domination properties of the same and consider their applications (together with the notion of a weak p-convergent operator, which we introduce in the present paper) to a study of the Schur property of order p. Also, the notion of a disjoint p-convergent operator on Banach lattices is introduced, studied and its applications to a study of the positive Schur property of order p are considered.展开更多
A new ferritic creep resistant steel has been developed by eliminating Nb and adding 1.5 mass % Re to a ferritic steel grade T/P23 with the aim of enhancing its mechanical properties at high temperature.Cast ingots of...A new ferritic creep resistant steel has been developed by eliminating Nb and adding 1.5 mass % Re to a ferritic steel grade T/P23 with the aim of enhancing its mechanical properties at high temperature.Cast ingots of both steels, new grade and ASTM T/P 23, were hot rolled at 900℃ and then submitted to a thermal treatment consisting of solubilization at 1050℃ and tempering at 700℃. Tempered bainitic microstructures obtained contain second phases reinforcing carbide particles, mainly M_6C and M_(23)C_6 at the boundaries of both, prior austenite grains and bainitic ferrite laths, as well as MC within the grains. Mechanical properties at temperatures ranging from 540 to 600℃ were studied by strain-ratechange tests in compression at strain rates between 10^(-7) and 10^(-4)s^(-1). These tests showed high stress exponents(n ≥ 20) and activation energies(Q ≈ 400 k J/mol) for both alloys, which were associated with a dislocation movement mechanism with a strong interaction between dislocations and precipitates. On the other hand, a creep exponent of 5 was derived for the stress dependence of minimum creep rate from conventional-type creep tests at 600℃. Although this stress exponent is usually related to a dislocation climb controlled creep mechanism, remarkable microstructural degradation observed with increasing creep time makes difficult to elucidate the true deformation mechanism controlling creep.展开更多
基金Funded by the National Natural Science Foundation of China(No.51472168)Natural Scientific Foundation of Liaoning Province(No.201602646)Open Fund from Liaoning Key Laboratory of Advanced Processing Technology for Metal Materials,Shenyang Ligong University,the Postdoctoral Research Foundation of Shenyang Ligong University
文摘The effect of the borax content and magnesia to phosphate ratio(M/P) on the hydration properties of the magnesium potassium phosphate cement(MKPC) with large volume of fly ash was investigated, and a five-hydration-stage for MKPCs was proposed. The results show that MKPC sets rapidly with less than 8% of borax, which is unfavorable to the application of MKPC on construction. Adding more than 8%(including 8%) of borax results in a secondary hydration peak for MKPC, in which the process of hydration can be divided into five stages, namely, pre-induction period, induction period, acceleration period, deceleration period and stable period. M/P ratios could not change the multi-step reactive stages but higher M/P ratios could accelerate the hydration. Borax tends to impact the formation of Mg-containing hydrated products.
基金supported by research grants of the University of Kurdistan,Iran。
文摘For analyzing the effects of forest litter and slope aspect on soil properties eight soil samples were collected at a depth of 0–10 cm near(i.e.,beneath the crown)and away from(i.e.,not influenced by crown)five Persian turpentine trees each on a north and a south slope at the same elevation in a Zagros forest,Iran.The litter beneath tree crowns and slope exposure were found to have significant interactive effects on C,N,P,K,and electrical conductivity of the soils,however,Ca,Mg and the soil pH were not significantly influenced by these factors.The soil beneath the crowns was enriched in cations compared to more distal positions.Generally,Persian turpentine trees have positive impacts on soil properties in the forest.Degrading or killing these trees by sap extraction,extreme grazing,cutting,fire and expansion of agriculture will lead to significant losses in soil fertility and increases in soil erosion.
文摘Some characterizations of preregular operators between two Banach lattices are presented. Then several sufficient conditions for preregular operators being regular are given, and some related results are also obtained.
基金Supported by the National Natural Science Foundation of China under Grant No 11374033
文摘We focus on two new 21) materials, i.e., monolayer and bilayer silicon phosphides (Sil P1). Based on the elastic- scattering Green's function, the electronic-transport properties of two-dimensional monolayer and bilayer Au- Si1P1-Au molecular junctions are studied. It is found that their bandgaps are narrow (0.16eV for a monolayer molecular junction and 0.26 e V for a bilayer molecular junction). Moreover, the calculated current-voltage char- acteristics indicate that the monolayer molecular junction provides constant output current (20 hA) over a wide voltage range, and the bilayer molecular junction provides higher current (42 hA).
文摘Let P be an arbitrary property of rings and homomorphically closed. For an arbitrary ring A we construct quasi P radical QP(A) with transfinite induction, and give another characterization of quasi P radical: QP(A)=∩{I α|I α is an ideal of A, and A/I α contains no non zero P ideal }.
基金Supported by the National Research Foundation of South Africa(Grant Nos.85619 and 101265)
文摘The notion of a p-convergent operator on a Banach space was originally introduced in 1993 by Castillo and SAnehez in the paper entitled "Dunford-Pettis-like properties of continuous vector function spaces". In the present paper we consider the p-convergent operators on Banach lattices, prove some domination properties of the same and consider their applications (together with the notion of a weak p-convergent operator, which we introduce in the present paper) to a study of the Schur property of order p. Also, the notion of a disjoint p-convergent operator on Banach lattices is introduced, studied and its applications to a study of the positive Schur property of order p are considered.
基金supported by the Spanish Ministry of Economy and Competitiveness(MINECO)under Grant MAT2012-39124,MAT2015-68919,and MAT2016-80875
文摘A new ferritic creep resistant steel has been developed by eliminating Nb and adding 1.5 mass % Re to a ferritic steel grade T/P23 with the aim of enhancing its mechanical properties at high temperature.Cast ingots of both steels, new grade and ASTM T/P 23, were hot rolled at 900℃ and then submitted to a thermal treatment consisting of solubilization at 1050℃ and tempering at 700℃. Tempered bainitic microstructures obtained contain second phases reinforcing carbide particles, mainly M_6C and M_(23)C_6 at the boundaries of both, prior austenite grains and bainitic ferrite laths, as well as MC within the grains. Mechanical properties at temperatures ranging from 540 to 600℃ were studied by strain-ratechange tests in compression at strain rates between 10^(-7) and 10^(-4)s^(-1). These tests showed high stress exponents(n ≥ 20) and activation energies(Q ≈ 400 k J/mol) for both alloys, which were associated with a dislocation movement mechanism with a strong interaction between dislocations and precipitates. On the other hand, a creep exponent of 5 was derived for the stress dependence of minimum creep rate from conventional-type creep tests at 600℃. Although this stress exponent is usually related to a dislocation climb controlled creep mechanism, remarkable microstructural degradation observed with increasing creep time makes difficult to elucidate the true deformation mechanism controlling creep.