The utilization of steel slag has been a worldwide issue for a long time. Attention is increasingly being paid to the technological innovation and development of steel slag. Aiming at the development of environmentall...The utilization of steel slag has been a worldwide issue for a long time. Attention is increasingly being paid to the technological innovation and development of steel slag. Aiming at the development of environmentally friendly steel slag concrete materials and their use in a recyclable economy ,Baosteel has recently been conducting research on and using many new building materials, including steel slag powder concrete, steel slag pervious concrete, steel slag counter weight concrete and so on. In this way, steel slag has been turned from a kind of solid waste into a value-added material. The technology of steel slag utilization has been enriched and developed,while a new model of using Baosteel steel slag in a recyclable economy has also been explored and practised.展开更多
Northeast of China and Jiangsu Province are major production areas of japonica rice in China.Rice from northeast of China is well-known for its good-eating and appearance quality,and that from Jiangsu Province is view...Northeast of China and Jiangsu Province are major production areas of japonica rice in China.Rice from northeast of China is well-known for its good-eating and appearance quality,and that from Jiangsu Province is viewed as inferior.However,little is known concerning the difference in physicochemical and sensory properties of rice between the major two production areas.Analysis of 16 commercial rice samples showed marked differences in physicochemical properties,including chalky grain rate,contents of amylose and protein and pasting properties between the two main areas.Northeastern rice contained more shortchain amylopectin as compared with Jiangsu rice.However,Jiangsu rice is comparable to northeastern rice in terms of sensory quality including overall acceptability and textural properties of springiness,stickiness and hardness as evaluated by trained panel.Our results indicated the limitation of conventional index of physicochemical properties,and suggested the necessity of identification of new factors controlling rice sensory property.In addition,the taste analyzer from Japan demonstrates limitation in distinguishing the differences between northeastern and Jiangsu rice,and therefore needs localization to fit China.展开更多
On the basis of measuring the magnetic parameters of sediment in Core YDZ1, combined with a grain size analysis and Carbon-14 dating, the magnetic properties of sediment and sedimentary environment in the Huanghe(Yel...On the basis of measuring the magnetic parameters of sediment in Core YDZ1, combined with a grain size analysis and Carbon-14 dating, the magnetic properties of sediment and sedimentary environment in the Huanghe(Yellow River) Delta area after the last glacial maximum have been studied. The results show that the ferrimagnetic minerals of a pseudo single domain and multi domain particles dominate the magnetic properties of sediment in Core YDZ1. The imperfect anti ferrimagnetic minerals have more contribution on sediment in a depth of 24.0–22.1 m, and more stable-single domain and pseudo single domain particles exist. The susceptibility of anhysteretic remanent magnetization and the ratio of the susceptibility of anhysteretic remanent magnetization to saturation isothermal remanent magnetization show a decrease trend below depth of 24 m, a marked increase trend in a depth of 24.0–13.5 m, and a rapid decrease at depth of 13.5 m, then a fluctuation trend upward. The above two magnetic parameters and the ratio of the susceptibility of anhysteretic remanent magnetization to the mass susceptibility can be regarded as the proxy indicators for the content of clay(〈4 μm)and the fine-grained size(〈32 μm). The sedimentary environment after the last glacial maximum in the Huanghe Delta area has experienced the fluvial facies, the tidal flat facies, the neritic facies, the pro delta facies, the delta front facies and the floodplain facies. Thickness of the Holocene transgression layer is 10.5 m and the depth of substrate is about 24 m according to the YDZ1 core. The sedimentary dynamic has a variation trend with strongweak-strong, which has been proved by the Flemming triangular schema.展开更多
In this paper,the influence of crystal-field on the Luminescence properties of Eu^(2+) in complex oxides are studied theoretically by using purely electrostatic model,the dependence of the 4f^65d levels on Eu-O bond d...In this paper,the influence of crystal-field on the Luminescence properties of Eu^(2+) in complex oxides are studied theoretically by using purely electrostatic model,the dependence of the 4f^65d levels on Eu-O bond distance is given.Quantum chemistry calculation shows that the splitting extent of 4f^65d energy band in cubic or in octahedral fields will be inversely proportional to R^5,where R is the distance of Eu^(2+) to oxygen ligand.The value of R affects slightly the location of the centre of 4f^65d energy band.According to the exper- imental spectrum data,we have discussed the influence of the host chemical composition,the replaced sites of Eu^(2+) and degree of covalency of Eu-O bond on luminescence properties of Eu^(2+).Some regularity of fluorescence spectrum was observed. In alkali-alkaline earth-phosphates,the splitting extent of 4f^65d band (△E) becomes smaller as the Eu-O bond distance (R) increases.In Na_(3-x)(PO_4)_(1-x)(SO_4)_x and Na_(2-x)CaSi_(1-x)P_xO_4 hosts,d-d emission peak of Eu^(2+) will shift to shorter wavelength with the increase of x's value. The crystal structure data show that Eu^(2+) in K_2Mg_2(SO_4)_3 is affected more strongly by crystal-field and covalancy than in KMgF_3,so K_2Mg_2(SO_4)_3:Eu^(2+) emits blue light (E_(em)~m=400nm) and KMgF_3:Eu^(2+) produces ultraviolet fluorescence.展开更多
Short-chain chlorinated paraffins(SCCPs) are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental beh...Short-chain chlorinated paraffins(SCCPs) are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental behaviors.A virtual molecule library of 42,720 C10-SCCP congeners covering the full structure spectrum was constructed.We explored the structural effects on the thermodynamic parameters and environmental degradability of C10-SCCPs through semi-empirical quantum chemical calculations.The thermodynamic properties were acquired using the AM1 method,and frontier molecular orbital analysis was carried out to obtain the EHOMO,ELUMO and ELUMO-EHOMO for degradability exploration at the same level.The influence of the chlorination degree(NCl on the relative stability and environmental degradation was elucidated.A novel structural descriptor,μ,was proposed to measure the dispersion of the chlorine atoms within a molecule.There were significant correlations between thermodynamic values and NCl,while the reported NCl-dependent pollution profile of C10-SCCPs in environmental samples was basically consistent with the predicted order of formation stability of C10-SCCP congeners.In addition,isomers with largeμ showed higher relative stability than those with small μ.This could be further verified by the relationship between μ and the reactivity of nucleophilic substitution and · OH attack respectively.The C10-SCCP congeners with less Cl substitution and lower dispersion degree are susceptible to environmental degradation via nucleophilic substitution and hydroxyl radical attack,while direct photolysis of C10-SCCP congeners cannot readily occur due to the large ELUMO-EHOMO values.The chlorination effect and the conclusions were further checked with appropriate density functional theory(DFT) calculations.展开更多
Physical, chemical and biochemical properties of silver nanoparticles (AgNPs) depend to a great extent on their size, shape, size distribution, and stabilizers located on their surface. This study focused on two typ...Physical, chemical and biochemical properties of silver nanoparticles (AgNPs) depend to a great extent on their size, shape, size distribution, and stabilizers located on their surface. This study focused on two typical stabilizers, namely citrates (cit), low molecular ions protecting nanoparticles by electrostatic repulsion, and polyvinylpyrrolidone (PVP), a hydrophilic, neutral, high molecular polymer protecting nanoparficles by steric stabilization. Natural bacterioplankton was collected from a eutrophic, downtown lake and exposed to five concentrations (0.1-5 mg/L) of AgNPs-PVP and AgNPs-cit. Responses were monitored after 1, 3, 5 and 7 days of exposure, by evaluating the survival rate of bacteria, their respiratory activity, and the general activity of extracellular esterases. A significantly better (greater) survival rate of bacterioplankton was observed in water with an addition of AgNPs-cit. The inhibition of extracellular esterases was observed only in samples containing AgNPs-PVP. The inhibitory effect increased proportionally to the concentration of AgNPs-PVP applied. Within the studied concentration range, there was no statistically significant inhibition of bacterioplankton respiratorv activity bv AgNPs-PVP and AgNPs-cit.展开更多
文摘The utilization of steel slag has been a worldwide issue for a long time. Attention is increasingly being paid to the technological innovation and development of steel slag. Aiming at the development of environmentally friendly steel slag concrete materials and their use in a recyclable economy ,Baosteel has recently been conducting research on and using many new building materials, including steel slag powder concrete, steel slag pervious concrete, steel slag counter weight concrete and so on. In this way, steel slag has been turned from a kind of solid waste into a value-added material. The technology of steel slag utilization has been enriched and developed,while a new model of using Baosteel steel slag in a recyclable economy has also been explored and practised.
基金supported by the Program for New Century Excellent Talents in University, China (NCET-10-0472)the National Natural Science Foundation of China (30971733 and 31171485)
文摘Northeast of China and Jiangsu Province are major production areas of japonica rice in China.Rice from northeast of China is well-known for its good-eating and appearance quality,and that from Jiangsu Province is viewed as inferior.However,little is known concerning the difference in physicochemical and sensory properties of rice between the major two production areas.Analysis of 16 commercial rice samples showed marked differences in physicochemical properties,including chalky grain rate,contents of amylose and protein and pasting properties between the two main areas.Northeastern rice contained more shortchain amylopectin as compared with Jiangsu rice.However,Jiangsu rice is comparable to northeastern rice in terms of sensory quality including overall acceptability and textural properties of springiness,stickiness and hardness as evaluated by trained panel.Our results indicated the limitation of conventional index of physicochemical properties,and suggested the necessity of identification of new factors controlling rice sensory property.In addition,the taste analyzer from Japan demonstrates limitation in distinguishing the differences between northeastern and Jiangsu rice,and therefore needs localization to fit China.
基金The National Natural Science Foundation of China under contract Nos 41306077 and 41501567the Major Program of University Natural Science Foundation of Jiangsu Province of China under contract No.14KJA170006the Natural Science Foundation of Shandong Province of China under contract No.ZR2013DQ025
文摘On the basis of measuring the magnetic parameters of sediment in Core YDZ1, combined with a grain size analysis and Carbon-14 dating, the magnetic properties of sediment and sedimentary environment in the Huanghe(Yellow River) Delta area after the last glacial maximum have been studied. The results show that the ferrimagnetic minerals of a pseudo single domain and multi domain particles dominate the magnetic properties of sediment in Core YDZ1. The imperfect anti ferrimagnetic minerals have more contribution on sediment in a depth of 24.0–22.1 m, and more stable-single domain and pseudo single domain particles exist. The susceptibility of anhysteretic remanent magnetization and the ratio of the susceptibility of anhysteretic remanent magnetization to saturation isothermal remanent magnetization show a decrease trend below depth of 24 m, a marked increase trend in a depth of 24.0–13.5 m, and a rapid decrease at depth of 13.5 m, then a fluctuation trend upward. The above two magnetic parameters and the ratio of the susceptibility of anhysteretic remanent magnetization to the mass susceptibility can be regarded as the proxy indicators for the content of clay(〈4 μm)and the fine-grained size(〈32 μm). The sedimentary environment after the last glacial maximum in the Huanghe Delta area has experienced the fluvial facies, the tidal flat facies, the neritic facies, the pro delta facies, the delta front facies and the floodplain facies. Thickness of the Holocene transgression layer is 10.5 m and the depth of substrate is about 24 m according to the YDZ1 core. The sedimentary dynamic has a variation trend with strongweak-strong, which has been proved by the Flemming triangular schema.
文摘In this paper,the influence of crystal-field on the Luminescence properties of Eu^(2+) in complex oxides are studied theoretically by using purely electrostatic model,the dependence of the 4f^65d levels on Eu-O bond distance is given.Quantum chemistry calculation shows that the splitting extent of 4f^65d energy band in cubic or in octahedral fields will be inversely proportional to R^5,where R is the distance of Eu^(2+) to oxygen ligand.The value of R affects slightly the location of the centre of 4f^65d energy band.According to the exper- imental spectrum data,we have discussed the influence of the host chemical composition,the replaced sites of Eu^(2+) and degree of covalency of Eu-O bond on luminescence properties of Eu^(2+).Some regularity of fluorescence spectrum was observed. In alkali-alkaline earth-phosphates,the splitting extent of 4f^65d band (△E) becomes smaller as the Eu-O bond distance (R) increases.In Na_(3-x)(PO_4)_(1-x)(SO_4)_x and Na_(2-x)CaSi_(1-x)P_xO_4 hosts,d-d emission peak of Eu^(2+) will shift to shorter wavelength with the increase of x's value. The crystal structure data show that Eu^(2+) in K_2Mg_2(SO_4)_3 is affected more strongly by crystal-field and covalancy than in KMgF_3,so K_2Mg_2(SO_4)_3:Eu^(2+) emits blue light (E_(em)~m=400nm) and KMgF_3:Eu^(2+) produces ultraviolet fluorescence.
基金jointly supported by the Chinese Academy of Sciences (Nos. KZCX2-YW-BR-25, XDB14030500 and YSW2013B01)the National High Technology Research and Development Program (863) of China (No. 2013AA065201)
文摘Short-chain chlorinated paraffins(SCCPs) are still controversial candidates for inclusion in the Stockholm Convention.The inherent mixture nature of SCCPs makes it rather difficult to explore their environmental behaviors.A virtual molecule library of 42,720 C10-SCCP congeners covering the full structure spectrum was constructed.We explored the structural effects on the thermodynamic parameters and environmental degradability of C10-SCCPs through semi-empirical quantum chemical calculations.The thermodynamic properties were acquired using the AM1 method,and frontier molecular orbital analysis was carried out to obtain the EHOMO,ELUMO and ELUMO-EHOMO for degradability exploration at the same level.The influence of the chlorination degree(NCl on the relative stability and environmental degradation was elucidated.A novel structural descriptor,μ,was proposed to measure the dispersion of the chlorine atoms within a molecule.There were significant correlations between thermodynamic values and NCl,while the reported NCl-dependent pollution profile of C10-SCCPs in environmental samples was basically consistent with the predicted order of formation stability of C10-SCCP congeners.In addition,isomers with largeμ showed higher relative stability than those with small μ.This could be further verified by the relationship between μ and the reactivity of nucleophilic substitution and · OH attack respectively.The C10-SCCP congeners with less Cl substitution and lower dispersion degree are susceptible to environmental degradation via nucleophilic substitution and hydroxyl radical attack,while direct photolysis of C10-SCCP congeners cannot readily occur due to the large ELUMO-EHOMO values.The chlorination effect and the conclusions were further checked with appropriate density functional theory(DFT) calculations.
文摘Physical, chemical and biochemical properties of silver nanoparticles (AgNPs) depend to a great extent on their size, shape, size distribution, and stabilizers located on their surface. This study focused on two typical stabilizers, namely citrates (cit), low molecular ions protecting nanoparticles by electrostatic repulsion, and polyvinylpyrrolidone (PVP), a hydrophilic, neutral, high molecular polymer protecting nanoparficles by steric stabilization. Natural bacterioplankton was collected from a eutrophic, downtown lake and exposed to five concentrations (0.1-5 mg/L) of AgNPs-PVP and AgNPs-cit. Responses were monitored after 1, 3, 5 and 7 days of exposure, by evaluating the survival rate of bacteria, their respiratory activity, and the general activity of extracellular esterases. A significantly better (greater) survival rate of bacterioplankton was observed in water with an addition of AgNPs-cit. The inhibition of extracellular esterases was observed only in samples containing AgNPs-PVP. The inhibitory effect increased proportionally to the concentration of AgNPs-PVP applied. Within the studied concentration range, there was no statistically significant inhibition of bacterioplankton respiratorv activity bv AgNPs-PVP and AgNPs-cit.