In the last two decades, China has become one of the areas that have the greatest potential in industrial production, thus it has ranked second only to USA in the flow of international capital. By the end of 1998, the...In the last two decades, China has become one of the areas that have the greatest potential in industrial production, thus it has ranked second only to USA in the flow of international capital. By the end of 1998, the real value of FDI (Foreign Direct Investment) in China has utilized has added up to $268.1 billion. The big flow of FDI has not only promoted the development of social economy, but also worsened the existing regional difference by choosing spatial location. Under this circumstance, China’s economy faces new restrictions and opportunities while adjusting its regional structure and industrial structure. So it is more and more important for us how to seize the opportunity, to seek the regularity of FDI in choosing location from the aspect of space, to set up relevant strategy to direct FDI at inland regions (areas deficient of capital), and to make appropriate policies, esp. the industrial and regional policies so as for FDI to exert positive influence and avoid negative influence on China and its regional economy and society. Based on the latest domestic and overseas materials and data of the FDI in China, combining with the investigation of the enterprises, this paper has systematically revealed the progress of development of the FDI in China and the developing conditions of the main enterprises directly invested by foreign capital since the reform and opening-up in China. The characters of FDI such as spatial concentration, transference as time goes on, change of the technical content and up-gradation of industrial structure and their forming mechanism have been studied. Then the basic conclusions have been made as follows. Firstly, FDI has been highly concentrated in space. But as time goes by, it has been transferring from coastal regions to inland ones, from big cities to their surrounding districts, and the degree of concentration is decreasing. Secondly, the technical content of the invested projects has gradually increased and the up-gradation of the industrial structure is obvious. Thirdly, the regional choice of the FDI in China is mainly affected by labor and other productive factors. The relative change of the cost of productive factors in different regions since the reform and opening-up is one of the main factors that have caused the spatial transference of the FDI in China. Fourthly, as people’s income increases and the accumulation of the capacity of the technique and labor advances, FDI whose aim is to get more market has increased and tended to transfer from coastal regions to inland ones. Fifthly, the changes of the industrial structure of the main areas and countries who have directly invested in China and the changes of inter-regional industries and regional policies in China are also the important factors that affect the industries directly invested by foreign capital and their spatial transference.展开更多
Objective: To discuss the expression of long noncoding RNA TUG1 (IneRNA-TUG1) in gastric carcinoma (GC) and its effects on the transferring and invading capacity of gastric carcinoma cells. Methods: Forty cases of car...Objective: To discuss the expression of long noncoding RNA TUG1 (IneRNA-TUG1) in gastric carcinoma (GC) and its effects on the transferring and invading capacity of gastric carcinoma cells. Methods: Forty cases of carcinoma tissue and para-carcinoma tissue were selected from GC patients who underwent surgical removal in Zhejiang Provincial Hospital of Chinese Traditional Medicine and Wenzhou Central Hospital from January, 2013 to December, 2014; the expressing level of IncRNA-TUG I in GC and para-C tissues was detected by applying the qRT-PCR technique. The correlation between IncRNA-TUG1 expression and patients' clinical data was classified and analyzed. SGC-7901 cells were transfected using IncRNA-TUG1 specific siRNA. Changes of the transferring and invading capacity of siRNA-transfected SGC-7901 cells were scratch-tested and transwell-detected. qRT-PCR was applied to detect the expression level of microRNA-144 after IncRNA-TUG1 was silenced. Changes of c-Met mRNA and protein expressions was detected by qRT-PCR and western -blot test. Results: The expression level of lneRNA-TUG1 in GC tissue was significant higher than that in para-C tissue (P<0.05) and the high expression level of IncRNA-TUG1 in GC tissue was significantly correlated with tumor lymph nodes metastasis and advance TNM phasing (/'<0.05). The transferring and invading capacity of SGC-7901 cells was highly inhibited after being transfected by IncRNA-TUG1 specific siRNA (P<0.05). The results of qRT-PCR and western -blot proved that the expression of microRNA-144 was significantly boosted and the expression level of c-Met mRNA and protein was inhibited after IncRNA-TUG1 was silenced (P<0.05). Conclusions: IncRNA-TUG1 shows an up -regulated expression in GC tissue and that bears a correlation with clinicopathological features of malignant tumor. IncRNATUGI can promote the transferring and invading capacity of GC by inhibiting the pathway of microRNA-144/c-Met.展开更多
Hg in acid soil could be activited by liming and become available to plant, if excessive or insufficient amount of lime was applied. The changes of Hg activity in acid soil with different rates of CaCO3 amendment Were...Hg in acid soil could be activited by liming and become available to plant, if excessive or insufficient amount of lime was applied. The changes of Hg activity in acid soil with different rates of CaCO3 amendment Were studied by a pot experiment. To predict the adequate amount of lime application, a simple method using the pH (EDTA) as an indicator was suggested. The suitable range of lime application was the amount of lime addition when the pH of soil-EDTA system was.raised to 4.0-4.3.展开更多
Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems,due to the lowest negative electrochemical potential and super high theoretical specific capacity.However,the growth of...Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems,due to the lowest negative electrochemical potential and super high theoretical specific capacity.However,the growth of lithium dendrite during the cycling process is still one of the most critical bottlenecks for its application.In this work,a slurry-like hybrid electrolyte is proposed towards the application for lithium metal anode,which is composed of a liquid electrolyte part and a nanometric silane-Al2O3 particle part.The hybrid electrolyte shows high ionic conductivity(3.89×10-3 S cm-1 at 25℃)and lithium-ion transference number(0.88).Especially,the resistance of hybrid electrolyte decreases compared to that of liquid electrolyte,while the viscosity of hybrid electrolyte increases.It is demonstrated that the hybrid electrolyte can effectively suppress the growth of lithium dendrite.Stable cycling of Li/Li cells at a current density up to 1 mA cm-2 is possible.The hybrid electrolyte helps to uniform the lithium ion flux inside the battery and partly comes from the formation of a rigid and highly conductive hybrid interfacial layer on the surface of lithium metal.This work not only provides a fresh way to stabilize lithium metal anode but also sheds light on further research for electrolyte optimization and design of lithium metal battery system.展开更多
The performance of rechargeable batteries and other electrochemical systems depends on the rate at which the working ion(often a cation)is transported from one electrode to the other.The cation transference number is ...The performance of rechargeable batteries and other electrochemical systems depends on the rate at which the working ion(often a cation)is transported from one electrode to the other.The cation transference number is an important transport parameter that affects this rate.The purpose of this perspective is to distinguish between approximate and rigorous methods used in the literature to measure the transference number.We emphasize the fact that this parameter is dependent on the reference frame used in the analysis;care must be taken when comparing values obtained from different sources to account for differences in reference frames.We present data obtained from a well-characterized electrolyte.We compare rigorously determined transference numbers in two reference frames with values obtained by an approximate method.We conclude with a qualitative discussion of the relationship between the transference number and salt concentration gradients that are obtained when current is drawn through a battery。展开更多
Hg vertical transference in soil water system was studied by analyzing Hg vertical distribution in soil column after adding Hg and one of the two leacheates, deionized water or acid rain, into soil column. The result...Hg vertical transference in soil water system was studied by analyzing Hg vertical distribution in soil column after adding Hg and one of the two leacheates, deionized water or acid rain, into soil column. The results indicated that Hg was hardly transferable in purple soil. About 86%～88% of the total soil Hg was distributed in the top layer (0～2 cm) and no Hg was detected in the leakage when the purple soil column was leached by deionized water and simulated acid rain. But Hg was more movable in yellow soil with only about 20%～22% of the total soil Hg distributed in the top layer (0～2 cm), and about 17%～25% washed out from the soil column by deionized water and simulated acid rain. Increment in soil bulk density could reduce Hg leaching, thus the more the Hg kept in soil, the less the Hg leached into underground water. Deionized water and acid rain almost played the same role in leaching Hg. Bentonite was most efficient in preventing Hg from vertical transferring in the soil column.展开更多
The stress transfer mechanism of steel fibre reinforced concrete is studied. The solutions for the stress and displacement were regarded as the superposition of ' the elementary solutions' and ' the improv...The stress transfer mechanism of steel fibre reinforced concrete is studied. The solutions for the stress and displacement were regarded as the superposition of ' the elementary solutions' and ' the improved solutions'. The elementary solutions were found by using two-dimensional elastic theory and the improved solutions were found by using the Love displacement function method. The calculated results indicate that the solutions possess good convergence. By comparing the three-dimensional solutions with the shear-lag solutions, evident difference may be found.展开更多
Some extraditional types—black rock series types of platinum group element (PGE), gold and silver mineralization occurrences were found in the Lower Cambrian in Guizhou and Hunan provinces of southwest China where PG...Some extraditional types—black rock series types of platinum group element (PGE), gold and silver mineralization occurrences were found in the Lower Cambrian in Guizhou and Hunan provinces of southwest China where PGE concentration reaches more than 800×10 -6. Sea floor hydrothermal fluid eruption was suggested to have been the main origin of the ore-forming materials. The whole process from the sedimentation to the redistribution of the ore-forming elements occurred on the conditions of intermediate to weak alkaline, weak reduction to weak oxidation. The temperature for the sedimentation and redistribution of the ore-forming elements was lower than 210 ℃. At such a low temperature, inert elements such as PGE, Au and Ag could quite easily be remobilized.展开更多
Studies show that 235UO2F2 was chiefly localized in kidneys, then in skeleton and liver. Its radioactivity in skeleton rose steadily while the concentration in kidneys and liver droped. 235UO2F2 was difficult to pass ...Studies show that 235UO2F2 was chiefly localized in kidneys, then in skeleton and liver. Its radioactivity in skeleton rose steadily while the concentration in kidneys and liver droped. 235UO2F2 was difficult to pass through the blood- testes barrier. With 1 to 6 h contact period, only 1.4-1.6 % 235UO2F2 was found in the intact skin, but 41-54 % in the abrasive skin. The dynamic retention of 235UO2F2 through intact or abrasive skins was also dominantly localized in kidneys, skeleton and liver. Accumulation of insoluble 235U3O8 in gastrointestinal tract was well described by a double- exponential- term expression. Values of retention were estimated for fast component T1= 0.34 d, and for relatively long term component T2= 4.05 d.展开更多
A general approach to transference principles for discrete and continuous sequence of operators (semi) groups is described. This allows one to recover the classical transference results of Calderon, Coifman and Weiss ...A general approach to transference principles for discrete and continuous sequence of operators (semi) groups is described. This allows one to recover the classical transference results of Calderon, Coifman and Weiss and of Berkson, Gilleppie and Muhly and the more recent one of the author. The method is applied to derive a new transference principle for (discrete and continuous) the sequence of operators semigroups that need not be grouped. As an application, functional calculus estimates for bounded sequence of operators with at most polynomially growing powers are derived, leading to a new proof of classical results by Peller from 1982. The method allows for a generalization of his results away from Hilbert spaces to -spaces and—involving the concept of γ-boundedness—to general spaces. Analogous results for strongly-continuous one-parameter (semi) groups are presented as well by Markus Haase [1]. Finally, an application is given to singular integrals for one-parameter semigroups.展开更多
As one of the Confucian classics, Shijing （i~） occupies a pivotal position in the development of Chinese culture. This paper makes a comparative study on the English translation of plant and animal images in Shijing...As one of the Confucian classics, Shijing （i~） occupies a pivotal position in the development of Chinese culture. This paper makes a comparative study on the English translation of plant and animal images in Shijing, trying to reveal the cultural connotations in them and to suggest some translation strategies for the correct transference of cultural implications in plant and animal images in the poems of this ancient book.展开更多
The dynamics of transportation, accumulation, diminishment and distribution of 95Nb in a simulated aquatic ecosystem was studied using the isotope-tracer technique, and a fitting equation was established by applicatio...The dynamics of transportation, accumulation, diminishment and distribution of 95Nb in a simulated aquatic ecosystem was studied using the isotope-tracer technique, and a fitting equation was established by application of a closed, five-compartment model. The results showed that when 95Nb was introduced into an aquatic system, it was transported and transformed via deposition in combination with other ions, and adsorption and absorption by aquatic organisms, resulting in redistribution and accumulation in different parts of the organisms. Following addition, the spe- cific activity of 95Nb in water decreased sharply within a short time, and then after reaching a certain value, it decreased more slowly. Sediment accumulated large amounts of 95Nb through the exchange of ions. Hyacinth (Eichhornia crassipes) also adsorbed a large amount of 95Nb in a short period of time. Snails (Bellamya purificata) and fish (Carassius auratus) were found to have a poor adsorption capacity of 95Nb. The amount of 95Nb found in the snail flesh was greater than that in the shell, and the 95Nb found in the fish was mainly distributed in the viscera. The amount of 95Nb in each individual component of the experimental system was affected over time.展开更多
Lithium metal batteries,with their light mass anode and high theoretical specific capacity of 3860 m Ah/g,have great potential for development in achieving high energy density.However,the generation of lithium dendrit...Lithium metal batteries,with their light mass anode and high theoretical specific capacity of 3860 m Ah/g,have great potential for development in achieving high energy density.However,the generation of lithium dendrites and the loss of dead lithium pose a serious threat to the safety and long-cycle stability of batteries.Herein,we utilize the Lewis acid-base interaction principle for lithium-ion migration regulation.Through loading solid-acids onto molecular sieves to immobilize Lewis base(PF_(6^(-))),we achieve accelerated dissociation of lithium salts and successfully increase the lithium ion transference number to 0.44.Lewis acid-base interaction helps lithium metal batteries achieve more uniform lithium deposition,with an average CE improved to 92.8%.The symmetrical cells can be plated/stripped stably for more than 800 h of cycling.Full cell with high surface-loaded LFP cathode(14 mg/cm^(2))exhibits impressively high capacity retention of 90.7%after 120 cycles at 0.5 C.展开更多
In the practical operations of the sodium ion(Na^(+))batteries(SIBs),the fast transport of Na+is desired for the rate performance,because the other ions in an electrolyte are electrochemically inert.In this study,we u...In the practical operations of the sodium ion(Na^(+))batteries(SIBs),the fast transport of Na+is desired for the rate performance,because the other ions in an electrolyte are electrochemically inert.In this study,we use molecular dynamics simulations to investigate the partial conductivity of Na^(+)(σNa^(+))in the salt-in-ionic liquid electrolytes(SILEs)composed of 1-ethyl-3-methylimidazolium(EMIM+)and bis(fluorosulfonyl)imide(FSI^(-))with various molar fraction of Na FSI.The simulations show that while the ionic conductivity of the SILE decreases monotonically with the increase of salt fraction of Na FSI,σNa^(+)peaks in the SILE with 0.5 molar fraction of Na FSI.Detailed analyses indicate that with the increase of salt fraction,the coordination structure of FSI^(-)around Na^(+)changed from bidentate manner to monodentate manner which weakens the binding of FSI-to Na^(+).The effects are two folds.On one hand,the increased monodentate coordinations cause a large aggregate that hinders the transport of Na+within the aggregate;on the other hand,the large aggregate captures most FSI-to form percolating ion network,and thus leaves a small portion of Na^(+)'s that are not in the large aggregate to be more“free”to transport in the SILE.展开更多
Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O soluti...Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O solution.The assembly and fluorescence behavior of PDI-COOH/Ca^(2+)were studied in detail by changing hydration state with different concentrations.Based on the differences in assembly morphology and stoichiometric ratios of PDICOOH/Ca^(2+),we proposed the fluorescence emission mechanism of PDI-COOH/Ca^(2+)in THF/H_(2)O and THF,respectively.This work reveals a novel strategy of aggregated state fluorescence enhancement and reminds us of the important role of water in molecular fluorescence emission and assembly.展开更多
Chemical titration method and lab-made chloride probes were jointly adopted to investigate the effects of water-to-cement (W/C) ratio and the impressed current density on chloride transport for cement-based materials ...Chemical titration method and lab-made chloride probes were jointly adopted to investigate the effects of water-to-cement (W/C) ratio and the impressed current density on chloride transport for cement-based materials during electrochemical chloride extraction (ECE) process.The dissolution of bound chlorides and the effect of current density on dissolution were analyzed.The variations of chloride concentration at different depths and the chloride transference process were monitored.Test results show that W/C ratios adopted have slight influence on chloride extraction,while chloride extraction efficiency is mainly determined by the impressed current density.During ECE process a portion of bound chloride ions dissolved and the amount of bound chlorides released is directly proportional to current density.展开更多
Growing market demand from portable electronics to electric automobiles boosts the development of lithium-ion batteries(LIBs)with high energy density and rate performance.However,strong solvation effect between lithiu...Growing market demand from portable electronics to electric automobiles boosts the development of lithium-ion batteries(LIBs)with high energy density and rate performance.However,strong solvation effect between lithium ions(Li^(+))and solvent molecules in common electrolytes limits the mobility of Li^(+)ions in electrolytes.Consequently,anions dominate the charge conduction in electrolytes,and in most cases,the value of Li^(+)transference number(T_(+))is between 0.2 and 0.4.A low T_(+)will aggravate concentration polarization in the process of charging and discharging,especially at high rate,which not only increases the overpotential but also intensifies side reactions,along with uneven deposition of lithium(Li)and the growth of lithium dendrites when lithium metal is used as anode.In this review,promising strategies to improve T_(+)in liquid electrolytes would be summarized.The migration of Li^(+)ions is affected directly by the types and concentration of lithium salts,solvents,and additives in bulk electrolytes.Besides,Li^(+)ions will pass through the separator and solid electrolyte interphase(SEI)when transferring between anodes and cathodes.With this in mind,we will classify and summarize threads of enhancing T_(+)from five aspects:lithium salts,solvents,additives,separators,and SEI based on different mechanisms,including covalently bonding,desolvation effect,Lewis acid-base interaction,electrostatic interaction,pore sieving,and supramolecular interaction.We believe this review will present a systematic understanding and summary on T_(+)and point out some feasible threads to enhance battery performance by enhancing T_(+).展开更多
基金the important project of National Natural Science Foundation of China (49831003)and the important project of the Ninth Five-Year
文摘In the last two decades, China has become one of the areas that have the greatest potential in industrial production, thus it has ranked second only to USA in the flow of international capital. By the end of 1998, the real value of FDI (Foreign Direct Investment) in China has utilized has added up to $268.1 billion. The big flow of FDI has not only promoted the development of social economy, but also worsened the existing regional difference by choosing spatial location. Under this circumstance, China’s economy faces new restrictions and opportunities while adjusting its regional structure and industrial structure. So it is more and more important for us how to seize the opportunity, to seek the regularity of FDI in choosing location from the aspect of space, to set up relevant strategy to direct FDI at inland regions (areas deficient of capital), and to make appropriate policies, esp. the industrial and regional policies so as for FDI to exert positive influence and avoid negative influence on China and its regional economy and society. Based on the latest domestic and overseas materials and data of the FDI in China, combining with the investigation of the enterprises, this paper has systematically revealed the progress of development of the FDI in China and the developing conditions of the main enterprises directly invested by foreign capital since the reform and opening-up in China. The characters of FDI such as spatial concentration, transference as time goes on, change of the technical content and up-gradation of industrial structure and their forming mechanism have been studied. Then the basic conclusions have been made as follows. Firstly, FDI has been highly concentrated in space. But as time goes by, it has been transferring from coastal regions to inland ones, from big cities to their surrounding districts, and the degree of concentration is decreasing. Secondly, the technical content of the invested projects has gradually increased and the up-gradation of the industrial structure is obvious. Thirdly, the regional choice of the FDI in China is mainly affected by labor and other productive factors. The relative change of the cost of productive factors in different regions since the reform and opening-up is one of the main factors that have caused the spatial transference of the FDI in China. Fourthly, as people’s income increases and the accumulation of the capacity of the technique and labor advances, FDI whose aim is to get more market has increased and tended to transfer from coastal regions to inland ones. Fifthly, the changes of the industrial structure of the main areas and countries who have directly invested in China and the changes of inter-regional industries and regional policies in China are also the important factors that affect the industries directly invested by foreign capital and their spatial transference.
基金supported by Traditional Chinese medicine scie nce and technology project of Zhejiang province(2015ZB108)
文摘Objective: To discuss the expression of long noncoding RNA TUG1 (IneRNA-TUG1) in gastric carcinoma (GC) and its effects on the transferring and invading capacity of gastric carcinoma cells. Methods: Forty cases of carcinoma tissue and para-carcinoma tissue were selected from GC patients who underwent surgical removal in Zhejiang Provincial Hospital of Chinese Traditional Medicine and Wenzhou Central Hospital from January, 2013 to December, 2014; the expressing level of IncRNA-TUG I in GC and para-C tissues was detected by applying the qRT-PCR technique. The correlation between IncRNA-TUG1 expression and patients' clinical data was classified and analyzed. SGC-7901 cells were transfected using IncRNA-TUG1 specific siRNA. Changes of the transferring and invading capacity of siRNA-transfected SGC-7901 cells were scratch-tested and transwell-detected. qRT-PCR was applied to detect the expression level of microRNA-144 after IncRNA-TUG1 was silenced. Changes of c-Met mRNA and protein expressions was detected by qRT-PCR and western -blot test. Results: The expression level of lneRNA-TUG1 in GC tissue was significant higher than that in para-C tissue (P<0.05) and the high expression level of IncRNA-TUG1 in GC tissue was significantly correlated with tumor lymph nodes metastasis and advance TNM phasing (/'<0.05). The transferring and invading capacity of SGC-7901 cells was highly inhibited after being transfected by IncRNA-TUG1 specific siRNA (P<0.05). The results of qRT-PCR and western -blot proved that the expression of microRNA-144 was significantly boosted and the expression level of c-Met mRNA and protein was inhibited after IncRNA-TUG1 was silenced (P<0.05). Conclusions: IncRNA-TUG1 shows an up -regulated expression in GC tissue and that bears a correlation with clinicopathological features of malignant tumor. IncRNATUGI can promote the transferring and invading capacity of GC by inhibiting the pathway of microRNA-144/c-Met.
文摘Hg in acid soil could be activited by liming and become available to plant, if excessive or insufficient amount of lime was applied. The changes of Hg activity in acid soil with different rates of CaCO3 amendment Were studied by a pot experiment. To predict the adequate amount of lime application, a simple method using the pH (EDTA) as an indicator was suggested. The suitable range of lime application was the amount of lime addition when the pH of soil-EDTA system was.raised to 4.0-4.3.
基金supported by the National Key R&D Program of China(Grant No.2016YFB0100100)supports from the National Natural Science Foundation of China(Grant No.51872305)。
文摘Lithium metal anode is regarded as the ultimate choice for next-generation energy storage systems,due to the lowest negative electrochemical potential and super high theoretical specific capacity.However,the growth of lithium dendrite during the cycling process is still one of the most critical bottlenecks for its application.In this work,a slurry-like hybrid electrolyte is proposed towards the application for lithium metal anode,which is composed of a liquid electrolyte part and a nanometric silane-Al2O3 particle part.The hybrid electrolyte shows high ionic conductivity(3.89×10-3 S cm-1 at 25℃)and lithium-ion transference number(0.88).Especially,the resistance of hybrid electrolyte decreases compared to that of liquid electrolyte,while the viscosity of hybrid electrolyte increases.It is demonstrated that the hybrid electrolyte can effectively suppress the growth of lithium dendrite.Stable cycling of Li/Li cells at a current density up to 1 mA cm-2 is possible.The hybrid electrolyte helps to uniform the lithium ion flux inside the battery and partly comes from the formation of a rigid and highly conductive hybrid interfacial layer on the surface of lithium metal.This work not only provides a fresh way to stabilize lithium metal anode but also sheds light on further research for electrolyte optimization and design of lithium metal battery system.
文摘The performance of rechargeable batteries and other electrochemical systems depends on the rate at which the working ion(often a cation)is transported from one electrode to the other.The cation transference number is an important transport parameter that affects this rate.The purpose of this perspective is to distinguish between approximate and rigorous methods used in the literature to measure the transference number.We emphasize the fact that this parameter is dependent on the reference frame used in the analysis;care must be taken when comparing values obtained from different sources to account for differences in reference frames.We present data obtained from a well-characterized electrolyte.We compare rigorously determined transference numbers in two reference frames with values obtained by an approximate method.We conclude with a qualitative discussion of the relationship between the transference number and salt concentration gradients that are obtained when current is drawn through a battery。
文摘Hg vertical transference in soil water system was studied by analyzing Hg vertical distribution in soil column after adding Hg and one of the two leacheates, deionized water or acid rain, into soil column. The results indicated that Hg was hardly transferable in purple soil. About 86%～88% of the total soil Hg was distributed in the top layer (0～2 cm) and no Hg was detected in the leakage when the purple soil column was leached by deionized water and simulated acid rain. But Hg was more movable in yellow soil with only about 20%～22% of the total soil Hg distributed in the top layer (0～2 cm), and about 17%～25% washed out from the soil column by deionized water and simulated acid rain. Increment in soil bulk density could reduce Hg leaching, thus the more the Hg kept in soil, the less the Hg leached into underground water. Deionized water and acid rain almost played the same role in leaching Hg. Bentonite was most efficient in preventing Hg from vertical transferring in the soil column.
文摘The stress transfer mechanism of steel fibre reinforced concrete is studied. The solutions for the stress and displacement were regarded as the superposition of ' the elementary solutions' and ' the improved solutions'. The elementary solutions were found by using two-dimensional elastic theory and the improved solutions were found by using the Love displacement function method. The calculated results indicate that the solutions possess good convergence. By comparing the three-dimensional solutions with the shear-lag solutions, evident difference may be found.
文摘Some extraditional types—black rock series types of platinum group element (PGE), gold and silver mineralization occurrences were found in the Lower Cambrian in Guizhou and Hunan provinces of southwest China where PGE concentration reaches more than 800×10 -6. Sea floor hydrothermal fluid eruption was suggested to have been the main origin of the ore-forming materials. The whole process from the sedimentation to the redistribution of the ore-forming elements occurred on the conditions of intermediate to weak alkaline, weak reduction to weak oxidation. The temperature for the sedimentation and redistribution of the ore-forming elements was lower than 210 ℃. At such a low temperature, inert elements such as PGE, Au and Ag could quite easily be remobilized.
基金The Project Supported by National Natural Science Foundation of China
文摘Studies show that 235UO2F2 was chiefly localized in kidneys, then in skeleton and liver. Its radioactivity in skeleton rose steadily while the concentration in kidneys and liver droped. 235UO2F2 was difficult to pass through the blood- testes barrier. With 1 to 6 h contact period, only 1.4-1.6 % 235UO2F2 was found in the intact skin, but 41-54 % in the abrasive skin. The dynamic retention of 235UO2F2 through intact or abrasive skins was also dominantly localized in kidneys, skeleton and liver. Accumulation of insoluble 235U3O8 in gastrointestinal tract was well described by a double- exponential- term expression. Values of retention were estimated for fast component T1= 0.34 d, and for relatively long term component T2= 4.05 d.
文摘A general approach to transference principles for discrete and continuous sequence of operators (semi) groups is described. This allows one to recover the classical transference results of Calderon, Coifman and Weiss and of Berkson, Gilleppie and Muhly and the more recent one of the author. The method is applied to derive a new transference principle for (discrete and continuous) the sequence of operators semigroups that need not be grouped. As an application, functional calculus estimates for bounded sequence of operators with at most polynomially growing powers are derived, leading to a new proof of classical results by Peller from 1982. The method allows for a generalization of his results away from Hilbert spaces to -spaces and—involving the concept of γ-boundedness—to general spaces. Analogous results for strongly-continuous one-parameter (semi) groups are presented as well by Markus Haase [1]. Finally, an application is given to singular integrals for one-parameter semigroups.
文摘As one of the Confucian classics, Shijing （i~） occupies a pivotal position in the development of Chinese culture. This paper makes a comparative study on the English translation of plant and animal images in Shijing, trying to reveal the cultural connotations in them and to suggest some translation strategies for the correct transference of cultural implications in plant and animal images in the poems of this ancient book.
文摘The dynamics of transportation, accumulation, diminishment and distribution of 95Nb in a simulated aquatic ecosystem was studied using the isotope-tracer technique, and a fitting equation was established by application of a closed, five-compartment model. The results showed that when 95Nb was introduced into an aquatic system, it was transported and transformed via deposition in combination with other ions, and adsorption and absorption by aquatic organisms, resulting in redistribution and accumulation in different parts of the organisms. Following addition, the spe- cific activity of 95Nb in water decreased sharply within a short time, and then after reaching a certain value, it decreased more slowly. Sediment accumulated large amounts of 95Nb through the exchange of ions. Hyacinth (Eichhornia crassipes) also adsorbed a large amount of 95Nb in a short period of time. Snails (Bellamya purificata) and fish (Carassius auratus) were found to have a poor adsorption capacity of 95Nb. The amount of 95Nb found in the snail flesh was greater than that in the shell, and the 95Nb found in the fish was mainly distributed in the viscera. The amount of 95Nb in each individual component of the experimental system was affected over time.
基金supported by the National Natural Science Foundation of China(No.22179007)。
文摘Lithium metal batteries,with their light mass anode and high theoretical specific capacity of 3860 m Ah/g,have great potential for development in achieving high energy density.However,the generation of lithium dendrites and the loss of dead lithium pose a serious threat to the safety and long-cycle stability of batteries.Herein,we utilize the Lewis acid-base interaction principle for lithium-ion migration regulation.Through loading solid-acids onto molecular sieves to immobilize Lewis base(PF_(6^(-))),we achieve accelerated dissociation of lithium salts and successfully increase the lithium ion transference number to 0.44.Lewis acid-base interaction helps lithium metal batteries achieve more uniform lithium deposition,with an average CE improved to 92.8%.The symmetrical cells can be plated/stripped stably for more than 800 h of cycling.Full cell with high surface-loaded LFP cathode(14 mg/cm^(2))exhibits impressively high capacity retention of 90.7%after 120 cycles at 0.5 C.
基金supported by National Natural Science Foundation of China(No.22273040)。
文摘In the practical operations of the sodium ion(Na^(+))batteries(SIBs),the fast transport of Na+is desired for the rate performance,because the other ions in an electrolyte are electrochemically inert.In this study,we use molecular dynamics simulations to investigate the partial conductivity of Na^(+)(σNa^(+))in the salt-in-ionic liquid electrolytes(SILEs)composed of 1-ethyl-3-methylimidazolium(EMIM+)and bis(fluorosulfonyl)imide(FSI^(-))with various molar fraction of Na FSI.The simulations show that while the ionic conductivity of the SILE decreases monotonically with the increase of salt fraction of Na FSI,σNa^(+)peaks in the SILE with 0.5 molar fraction of Na FSI.Detailed analyses indicate that with the increase of salt fraction,the coordination structure of FSI^(-)around Na^(+)changed from bidentate manner to monodentate manner which weakens the binding of FSI-to Na^(+).The effects are two folds.On one hand,the increased monodentate coordinations cause a large aggregate that hinders the transport of Na+within the aggregate;on the other hand,the large aggregate captures most FSI-to form percolating ion network,and thus leaves a small portion of Na^(+)'s that are not in the large aggregate to be more“free”to transport in the SILE.
文摘Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O solution.The assembly and fluorescence behavior of PDI-COOH/Ca^(2+)were studied in detail by changing hydration state with different concentrations.Based on the differences in assembly morphology and stoichiometric ratios of PDICOOH/Ca^(2+),we proposed the fluorescence emission mechanism of PDI-COOH/Ca^(2+)in THF/H_(2)O and THF,respectively.This work reveals a novel strategy of aggregated state fluorescence enhancement and reminds us of the important role of water in molecular fluorescence emission and assembly.
基金supported by the National Basic Research Program of China (973 Program) (Grant No.2009CB623105)Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20070247063)+1 种基金the Open Research Fund of State Key Laboratory of Costal and Offshore Engineering (Grant No.LP0707)the Scientific Research Foundation for Returned Overseas Chinese Scholars of Ministry of Education of China
文摘Chemical titration method and lab-made chloride probes were jointly adopted to investigate the effects of water-to-cement (W/C) ratio and the impressed current density on chloride transport for cement-based materials during electrochemical chloride extraction (ECE) process.The dissolution of bound chlorides and the effect of current density on dissolution were analyzed.The variations of chloride concentration at different depths and the chloride transference process were monitored.Test results show that W/C ratios adopted have slight influence on chloride extraction,while chloride extraction efficiency is mainly determined by the impressed current density.During ECE process a portion of bound chloride ions dissolved and the amount of bound chlorides released is directly proportional to current density.
基金support by the National Natural Science Foundation of China(Nos.22071133 and 21905040)the Tsinghua University-China Petrochemical Corporation Joint Institute for Green Chemical Engineering(No.421120)+1 种基金Tsinghua-Foshan Innovation Special Fund(TFISF,No.2020THFS0130)Tsinghua University Initiative Scientific Research Program.
文摘Growing market demand from portable electronics to electric automobiles boosts the development of lithium-ion batteries(LIBs)with high energy density and rate performance.However,strong solvation effect between lithium ions(Li^(+))and solvent molecules in common electrolytes limits the mobility of Li^(+)ions in electrolytes.Consequently,anions dominate the charge conduction in electrolytes,and in most cases,the value of Li^(+)transference number(T_(+))is between 0.2 and 0.4.A low T_(+)will aggravate concentration polarization in the process of charging and discharging,especially at high rate,which not only increases the overpotential but also intensifies side reactions,along with uneven deposition of lithium(Li)and the growth of lithium dendrites when lithium metal is used as anode.In this review,promising strategies to improve T_(+)in liquid electrolytes would be summarized.The migration of Li^(+)ions is affected directly by the types and concentration of lithium salts,solvents,and additives in bulk electrolytes.Besides,Li^(+)ions will pass through the separator and solid electrolyte interphase(SEI)when transferring between anodes and cathodes.With this in mind,we will classify and summarize threads of enhancing T_(+)from five aspects:lithium salts,solvents,additives,separators,and SEI based on different mechanisms,including covalently bonding,desolvation effect,Lewis acid-base interaction,electrostatic interaction,pore sieving,and supramolecular interaction.We believe this review will present a systematic understanding and summary on T_(+)and point out some feasible threads to enhance battery performance by enhancing T_(+).
