Co(Ⅱ)and Ni(Ⅱ)are two common toxic heavy metals,and may simultaneously exist in contaminated water,soil,and sediment systems in Earth’s surface environment.Under this circumstance,competitive adsorption between the...Co(Ⅱ)and Ni(Ⅱ)are two common toxic heavy metals,and may simultaneously exist in contaminated water,soil,and sediment systems in Earth’s surface environment.Under this circumstance,competitive adsorption between the two metals may influence their migration,toxicity,and bioavailability.In this research,the competitive sorption of Co(Ⅱ)and Ni(Ⅱ)on γ-Al_2O_3was studied using both macroscopic sorption experiments and extended X-ray absorption fine structure(EXAFS)spectroscopy.Results suggest that Ni(Ⅱ)reduced the amount of Co(Ⅱ)sorption in a binary-solute system at pH 6.0.This is because both Co(Ⅱ)and Ni(Ⅱ)form inner-sphere surface complexes during sorption on γ-Al_2O_3and compete for the surface reactive sites.However,Co(Ⅱ)exhibited a negligible influence on sorption amount of Ni(Ⅱ)under the same conditions,which suggests Ni(Ⅱ)has a stronger affinity to alumina surface.At pH 7.5,Co(Ⅱ)and Ni(Ⅱ)sorption density were much higher than that at pH 6.0,but there no mutual competitive effect was observed.EXAFS analysis further revealed that formation of layered double-hydrated precipitates was the dominant sorption mechanism for both Co(Ⅱ)and Ni(Ⅱ)at pH 7.5.Because this type of sorption does not rely on surface reactive sites,there was no competition between Co(Ⅱ)and Ni(Ⅱ).This finding sheds light on risk assessment and remediation of Ni/Co pollution.展开更多
The regions of the selective oxidation of the the production of 4-vinylpyridine, 4-vinylpyridine coherent-synchronized mechanism is suggested for 4-ethylpyridine and piperidine. The HO^＊2 radical plays 4-ethylpyridin...The regions of the selective oxidation of the the production of 4-vinylpyridine, 4-vinylpyridine coherent-synchronized mechanism is suggested for 4-ethylpyridine and piperidine. The HO^＊2 radical plays 4-ethylpyridine and piperidine have been found, and the optimal conditions for N-monoxide and pyridine have been determined. The most probable hydrogen peroxide decomposition and the free-radical chain oxidation of the key role in this mechanism.展开更多
Accurate estimation of evapotranspiration(ET),especially at the regional scale,is an extensively investigated topic in the field of water science. The ability to obtain a continuous time series of highly precise ET va...Accurate estimation of evapotranspiration(ET),especially at the regional scale,is an extensively investigated topic in the field of water science. The ability to obtain a continuous time series of highly precise ET values is necessary for improving our knowledge of fundamental hydrological processes and for addressing various problems regarding the use of water. This objective can be achieved by means of ET data assimilation based on hydrological modeling. In this paper,a comprehensive review of ET data assimilation based on hydrological modeling is provided. The difficulties and bottlenecks of using ET,being a non-state variable,to construct data assimilation relationships are elaborated upon,with a discussion and analysis of the feasibility of assimilating ET into various hydrological models. Based on this,a new easy-to-operate ET assimilation scheme that includes a water circulation physical mechanism is proposed. The scheme was developed with an improved data assimilation system that uses a distributed time-variant gain model(DTVGM),and the ET-soil humidity nonlinear time response relationship of this model. Moreover,the ET mechanism in the DTVGM was improved to perfect the ET data assimilation system. The new scheme may provide the best spatial and temporal characteristics for hydrological states,and may be referenced for accurate estimation of regional evapotranspiration.展开更多
To study the effect of different deformation mechanisms on the chemical structure of anthracite coals and further understand the correlation between changed chemical structures and coal and gas outburst, ten groups of...To study the effect of different deformation mechanisms on the chemical structure of anthracite coals and further understand the correlation between changed chemical structures and coal and gas outburst, ten groups of sub-high-temperature and sub-high-pressure deformation experiments were performed. All samples maintained primary structure, which were collected from the Qudi Mine in the southern Qinshui Basin of China. The samples were analyzed by ultimate analysis, Vitrinite Reflection(VR), Fourier Transform Infrared spectroscopy(FTIR), and Raman spectroscopy both before and after deformation experiments for contrasting. The results showed that the VR values of all samples after experiments were significantly higher than before experiments, which suggested that the metamorphism degree of anthracite coals was increased by deformation. The results also indicated that both temperature and strain rate had significant effects on the chemical structure of anthracite coals. At a high strain rate of 4×10?5 s?1, the deformation of the samples was mainly brittle in which the mechanical energy was transformed mainly into frictional energy. In this situation, all samples developed several distinct fractured surfaces and the change of chemical structures was not obvious. On the contrary, with the decrease of the strain rates, the ductile deformation was dominated and the mechanical energy was mainly transformed into strain energy, resulting in the accumulation of deformation energy confessed by increasing quantity of dislocation and creep in the coal's interior nucleus. The absorption in the aromatic ring groups increased; otherwise the absorption in the aliphatic structures and ether oxygen groups decreased rapidly. During these experiments, CO was collected from two experimental samples. The number of aromatic rings and the structure defects within the two generated gas samples increased and the degree of molecular structure orders decreased.展开更多
The curative effects of Chinese herbal compounds result from the coordination of numerous natural compounds.We aimed to review the mechanism of action of Traditional Chinese Medicine(TCM)compounds(TCMC),explore the ra...The curative effects of Chinese herbal compounds result from the coordination of numerous natural compounds.We aimed to review the mechanism of action of Traditional Chinese Medicine(TCM)compounds(TCMC),explore the rationality of formulation theory and synergistic effects in TCM compounds,and analyze the effectiveness of drug compatibility of TCMC in molecular biology.This literature review covers the mechanisms of the anti-tumor effects of compounds,and their synergistic antitumor mechanisms.We aim to provide reference for the effective development and use of natural resources and the organic combination of TCM and modern medicine using molecular biology.展开更多
基金co-funded by the National Natural Science Foundation of China(No.41473084)the Project of China Geological Survey(No.12120114092001)the 1000 Youth Talent program
文摘Co(Ⅱ)and Ni(Ⅱ)are two common toxic heavy metals,and may simultaneously exist in contaminated water,soil,and sediment systems in Earth’s surface environment.Under this circumstance,competitive adsorption between the two metals may influence their migration,toxicity,and bioavailability.In this research,the competitive sorption of Co(Ⅱ)and Ni(Ⅱ)on γ-Al_2O_3was studied using both macroscopic sorption experiments and extended X-ray absorption fine structure(EXAFS)spectroscopy.Results suggest that Ni(Ⅱ)reduced the amount of Co(Ⅱ)sorption in a binary-solute system at pH 6.0.This is because both Co(Ⅱ)and Ni(Ⅱ)form inner-sphere surface complexes during sorption on γ-Al_2O_3and compete for the surface reactive sites.However,Co(Ⅱ)exhibited a negligible influence on sorption amount of Ni(Ⅱ)under the same conditions,which suggests Ni(Ⅱ)has a stronger affinity to alumina surface.At pH 7.5,Co(Ⅱ)and Ni(Ⅱ)sorption density were much higher than that at pH 6.0,but there no mutual competitive effect was observed.EXAFS analysis further revealed that formation of layered double-hydrated precipitates was the dominant sorption mechanism for both Co(Ⅱ)and Ni(Ⅱ)at pH 7.5.Because this type of sorption does not rely on surface reactive sites,there was no competition between Co(Ⅱ)and Ni(Ⅱ).This finding sheds light on risk assessment and remediation of Ni/Co pollution.
文摘The regions of the selective oxidation of the the production of 4-vinylpyridine, 4-vinylpyridine coherent-synchronized mechanism is suggested for 4-ethylpyridine and piperidine. The HO^＊2 radical plays 4-ethylpyridine and piperidine have been found, and the optimal conditions for N-monoxide and pyridine have been determined. The most probable hydrogen peroxide decomposition and the free-radical chain oxidation of the key role in this mechanism.
基金National Key Basic Research Program of China(973 Program),No.2015CB452701National Natural Science Foundation of China,No.41271003+1 种基金No.41371043No.41401042
文摘Accurate estimation of evapotranspiration(ET),especially at the regional scale,is an extensively investigated topic in the field of water science. The ability to obtain a continuous time series of highly precise ET values is necessary for improving our knowledge of fundamental hydrological processes and for addressing various problems regarding the use of water. This objective can be achieved by means of ET data assimilation based on hydrological modeling. In this paper,a comprehensive review of ET data assimilation based on hydrological modeling is provided. The difficulties and bottlenecks of using ET,being a non-state variable,to construct data assimilation relationships are elaborated upon,with a discussion and analysis of the feasibility of assimilating ET into various hydrological models. Based on this,a new easy-to-operate ET assimilation scheme that includes a water circulation physical mechanism is proposed. The scheme was developed with an improved data assimilation system that uses a distributed time-variant gain model(DTVGM),and the ET-soil humidity nonlinear time response relationship of this model. Moreover,the ET mechanism in the DTVGM was improved to perfect the ET data assimilation system. The new scheme may provide the best spatial and temporal characteristics for hydrological states,and may be referenced for accurate estimation of regional evapotranspiration.
基金supported by National Natural Science Foundation of China(Grant No.41030422)Strategic Leading Special Science and Technology from Academy of Chinese Academy of Sciences(Grant No.XDA05030100)
文摘To study the effect of different deformation mechanisms on the chemical structure of anthracite coals and further understand the correlation between changed chemical structures and coal and gas outburst, ten groups of sub-high-temperature and sub-high-pressure deformation experiments were performed. All samples maintained primary structure, which were collected from the Qudi Mine in the southern Qinshui Basin of China. The samples were analyzed by ultimate analysis, Vitrinite Reflection(VR), Fourier Transform Infrared spectroscopy(FTIR), and Raman spectroscopy both before and after deformation experiments for contrasting. The results showed that the VR values of all samples after experiments were significantly higher than before experiments, which suggested that the metamorphism degree of anthracite coals was increased by deformation. The results also indicated that both temperature and strain rate had significant effects on the chemical structure of anthracite coals. At a high strain rate of 4×10?5 s?1, the deformation of the samples was mainly brittle in which the mechanical energy was transformed mainly into frictional energy. In this situation, all samples developed several distinct fractured surfaces and the change of chemical structures was not obvious. On the contrary, with the decrease of the strain rates, the ductile deformation was dominated and the mechanical energy was mainly transformed into strain energy, resulting in the accumulation of deformation energy confessed by increasing quantity of dislocation and creep in the coal's interior nucleus. The absorption in the aromatic ring groups increased; otherwise the absorption in the aliphatic structures and ether oxygen groups decreased rapidly. During these experiments, CO was collected from two experimental samples. The number of aromatic rings and the structure defects within the two generated gas samples increased and the degree of molecular structure orders decreased.
基金Supported by National Science&Technology Pillar Program in the 11th Five Year Plan of China(No.2006BAI11B0801)
文摘The curative effects of Chinese herbal compounds result from the coordination of numerous natural compounds.We aimed to review the mechanism of action of Traditional Chinese Medicine(TCM)compounds(TCMC),explore the rationality of formulation theory and synergistic effects in TCM compounds,and analyze the effectiveness of drug compatibility of TCMC in molecular biology.This literature review covers the mechanisms of the anti-tumor effects of compounds,and their synergistic antitumor mechanisms.We aim to provide reference for the effective development and use of natural resources and the organic combination of TCM and modern medicine using molecular biology.
