An efficient synthesis of carbon nanofibers by pyrolysis of as-prepared polypyrrole nanowires was reported. Under the subsequent KOH activation, a significant morphology variation was detected and the obtained sample ...An efficient synthesis of carbon nanofibers by pyrolysis of as-prepared polypyrrole nanowires was reported. Under the subsequent KOH activation, a significant morphology variation was detected and the obtained sample took on a ribbon-like structure. The morphology and structure of the carbon nanofibers and carbon nanoribbons were characterized. When the as-prepared one-dimensional carbon nanostructures were used as anode materials in lithium ion batteries, both of them exhibited superior cyclical stability and good rate properties. After 50 cycles, the reversible capacity of carbon nanofibers electrode maintained 530 mA·h/g. Concerning carbon nanoribbons, the reversible capacity is always larger than 850 mA·h/g and the reversible capacity retention after 23 cycles is 86%.展开更多
The Doppler-limited absorption spectrum of 16O2^＋ cation was observed in the region of 11385-12100 cm^-1 by optical heterodyne velocity modulation absorption spectroscopy （OH-VMS）. The transitions were assigned to ...The Doppler-limited absorption spectrum of 16O2^＋ cation was observed in the region of 11385-12100 cm^-1 by optical heterodyne velocity modulation absorption spectroscopy （OH-VMS）. The transitions were assigned to the （2, 19）, （3, 20）, and （5, 21） bands in the second negative system （A^2∏u-X^2∏g）. All the available lines measured using OH-VMS were global fitted in a nonlinear least-squares fitting procedure, and precise molecular constants （Bv, Av, Dv, pv, qv, γv） were obtained for the involved levels.展开更多
The effects of simulated nitrogen(N)deposition on soil exchangeable cations were studied in three forest types of subtropical China.Four N treatments with three replications were designed for the monsoon evergreen bro...The effects of simulated nitrogen(N)deposition on soil exchangeable cations were studied in three forest types of subtropical China.Four N treatments with three replications were designed for the monsoon evergreen broadleaf forest (mature forest):control(0 kg N ha-1 year-1),low N(50 kg N ha-1 year-1),medium N(100 kg N ha-1 year-1)and high N(150 kg N ha-1 year-1),and only three treatments(i.e.,control,low N,medium N)were established for the pine and mixed forests.Nitrogen had been applied continuously for 26 months before the measurement.The mature forest responded more rapidly and intensively to N additions than the pine and mixed forests,and exhibited some significant negative symptoms,e.g.,soil acidification,Al mobilization and leaching of base cations from soil.The pine and mixed forests responded slowly to N additions and exhibited no significant response of soil cations.Response of soil exchangeable cations to N deposition varied in the forests of subtropical China,depending on soil N status and land-use history.展开更多
A new reactive and extractive distillation process with ionic liquids as entrainer and catalyst （RED-IL）was proposed to produce methanol and n-butyl acetate by transesterification reaction of methyl acetate with n-b...A new reactive and extractive distillation process with ionic liquids as entrainer and catalyst （RED-IL）was proposed to produce methanol and n-butyl acetate by transesterification reaction of methyl acetate with n-butanol. The RED-IL process was simulated via a rigorous model, and high purity products of methanol and n-butyl acetate can be obtained in such a process. The effects of reflux ratio, feed mode, holdup, feed location, entrainer ratio and catalyst concentration on RED-IL process were investigated. The conversion of methyl acetate and purities of products increase with the holdup in column, entrainer ratio and catalyst content. An optimal reflux ratio exists in RED-IL process. Comparing to the mixed-feed mode, the segregated-feed mode is more effective, in which the optimal feed locations of reactants exist.展开更多
To investigate the interactions of oppositely charged sites on the surfaces of variable-charge soil particles with cations and anions, and to evaluate the mean Gibbs free binding and adsorption energies of various cat...To investigate the interactions of oppositely charged sites on the surfaces of variable-charge soil particles with cations and anions, and to evaluate the mean Gibbs free binding and adsorption energies of various cations on particles of red soil and latosol, clay fractions smaller than 2 μm were separated from samples of the two variable-charge soils. Ferric oxides were removed from part of the clay fractions, which were then saturated with various chlorides （NaC1, KCl, CaCl2, CdCl2 or LaCl3）. Electrical conductivities （EC） of dilute suspensions of the original and of the iron oxides-free clay fractions in deionized water were measured with the SHP-2 short high-voltage pulse apparatus, which enables measurement of the Wien effect at field strengths （E） from 14 to 250 kV cm^-1. The Wien effect （EC-E） curves revealed EC increases of red soil suspensions between 14 and 200 kV cm^-1, of 8.3, 8.4, 12.1, 5.9, and 1.2 μS cm^-1 for NaCl, KCl, CaCl2, CdCl2, and LaCl3, respectively, reflecting the differing interactions with the various cations and chloride. The EC increments with the iron-free red soil suspensions were higher, being 29.7, 17.2, and 15.3 μS cm^-1 for NaCl, CaCl2, and CdCl2, respectively. In the natural latosol suspensions the EC increments were practically zero, whereas in the iron-free fractions there were significant EC increments of 10.3, 5.7, 5.0, and 1.6μS cm^-1 for NaCl, CaCl2, CdCl2, and LaCl3, respectively.展开更多
The remaining phosphorus (Prem), P concentration that remains in solution after shaking soil with 0.01 mol L-1 CaCl2 containing 60μg mL-1 P, is a very useful index for studies related to the chemistry of variable cha...The remaining phosphorus (Prem), P concentration that remains in solution after shaking soil with 0.01 mol L-1 CaCl2 containing 60μg mL-1 P, is a very useful index for studies related to the chemistry of variable charge soils. Although the Prem determination is a simple procedure, the possibility of estimating accurate values of this index from easily and/or routinely determined soil properties can be very useful for practical purposes. The present research evaluated the Prem estimation through multiple regression analysis in which routinely determined soil chemical data, soil clay content and soil pH measured in 1 mol L-1 NaF (pHNaF) figured as Prem predictor variables. The Prem can be estimated with acceptable accuracy using the above-mentioned approach, and pHNaF not only substitutes for clay content as a predictor variable but also confers more accuracy to the Prem estimates.展开更多
Ten seed borne fungi （Alternaria sp., Aspergillus sp., Aureobasidium sp., Cladosporium sp., Dreschslera sp., Penicillium sp., Rhizoctonia sp., Stemphylium sp., Mueor sp. and Rhizopus sp.） were isolated and identifie...Ten seed borne fungi （Alternaria sp., Aspergillus sp., Aureobasidium sp., Cladosporium sp., Dreschslera sp., Penicillium sp., Rhizoctonia sp., Stemphylium sp., Mueor sp. and Rhizopus sp.） were isolated and identified from two wheat varieties, the highest frequency of seed borne fungi was observed on wheat cultivar site Moll4 Alternaria sp.. Their mean and standard deviation was （5.5 ~ 1.69） while the lowest frequency fungal isolated was Dreschslera sp. and Rhizopus sp.. Their mean and standard deviation was （0.1 ~ 0.64）. The aflatoxin-producing isolates appeared as gray or black colonies in the UV photographs, whereas nonproducing isolates appeared as white colonies, the plate five colony four （P5CO4） showed the positive results which means the presence of aflatoxin as compaired to the control which showed the ngative results. Ammonium Hydroxide Vapor-Induced Color Change method used which the dish was inverted and 1 or 2 drops of concentrated ammonium hydroxide solution are placed on the inside of the lid. The undersides of aflatoxin-producing colonies quickly turn plum-red after the bottom of the Petri dish has been inverted over the lid containing the ammonium hydroxide aspositive result in （P5CO4） and （P7CO4） observed. Essentially no color change occurs on the undersides of colonies that are not producing aflatoxinsthis indicate to the negative results （control）. The main objective of this study is to isolation, identification and rapid detection of aflatoxin from wheat seed borne fungi.展开更多
In this paper, a procedure is proposed for measuring Wigner characteristic function for motion of a single trapped ion. In the scheme, the trapped ion is driven by two laser beams with different frequencies tuned to t...In this paper, a procedure is proposed for measuring Wigner characteristic function for motion of a single trapped ion. In the scheme, the trapped ion is driven by two laser beams with different frequencies tuned to the first lower and upper vibrational sidebands, respectively. Unlike other previous scheme, our scheme does not require the displacement of the external state before the ion-laser interaction and thus our scheme night be more simple and feasible. The scheme can also be used to prepare the motional Schroedinger cat states and entangled coherent states.展开更多
Many lakes in Southeastern Wisconsin(the metropolitan-Milwaukee area) are gradually becoming increasingly "salty".While these waterbodies would not be considered presently to be saline lakes,there has been a...Many lakes in Southeastern Wisconsin(the metropolitan-Milwaukee area) are gradually becoming increasingly "salty".While these waterbodies would not be considered presently to be saline lakes,there has been a rapid increase in the chloride concentrations in most of these lakes over the last 30 years,with the lakes increasing from a mean chloride concentration of about 19 mg/L to over 100 mg/L in some cases.While ecological impacts can be expected when chloride values exceed 250 mg/L,the rate of increase presents a basis for concern,especially since the underlying geology of the region is based on limestone/dolomite which is deficient in chlorides.Thus,the origin of the chlorides is anthropogenic:human and industrial wastewaters(treatment of which has effected improvements in trophic status but has not affected other water-borne contaminants) and winter de-icing practices based upon large quantities of sodium chloride are major contributors to the increasing concentrations of chloride in the region's waterways.Without taking remedial measures,the rate of salinization is expected to continue to increase,resulting,ultimately,in the alteration of the freshwater systems in the region.展开更多
The critical properties of the bond-diluted mixed spin-1/2 and spin-1 transverse Ising system with singleion anisotropy are investigated by means of the effective field theory with correlations. Particular emphasis is...The critical properties of the bond-diluted mixed spin-1/2 and spin-1 transverse Ising system with singleion anisotropy are investigated by means of the effective field theory with correlations. Particular emphasis is given to the square lattice for which phase diagrams are obtained. If transverse field varies in the certain ranges we find that the tricritical point is obtained for the value of the bond concentration in a restricted region. We also observe that the reentrant phase transition may occur in the present system if single-ion anisotropy parameter is not large and if transverse field is small. On the other hand, for certain values of the system parameters, new induced magnetic ordering can be obtained. We find a number of interesting phenomena that are not predicted by previous literatures. The influence of the transverse field on the behaviours of the reentrant phase transition and induced magnetic ordering is discussed. A detailed description of the phase transition is presented.展开更多
基金Projects (51204209,51274240) supported by the National Natural Science Foundation of China
文摘An efficient synthesis of carbon nanofibers by pyrolysis of as-prepared polypyrrole nanowires was reported. Under the subsequent KOH activation, a significant morphology variation was detected and the obtained sample took on a ribbon-like structure. The morphology and structure of the carbon nanofibers and carbon nanoribbons were characterized. When the as-prepared one-dimensional carbon nanostructures were used as anode materials in lithium ion batteries, both of them exhibited superior cyclical stability and good rate properties. After 50 cycles, the reversible capacity of carbon nanofibers electrode maintained 530 mA·h/g. Concerning carbon nanoribbons, the reversible capacity is always larger than 850 mA·h/g and the reversible capacity retention after 23 cycles is 86%.
基金ACKNOWLEDGMENTS This work was supported Science Foundation of China by the National Natural （No.11004062）.
文摘The Doppler-limited absorption spectrum of 16O2^＋ cation was observed in the region of 11385-12100 cm^-1 by optical heterodyne velocity modulation absorption spectroscopy （OH-VMS）. The transitions were assigned to the （2, 19）, （3, 20）, and （5, 21） bands in the second negative system （A^2∏u-X^2∏g）. All the available lines measured using OH-VMS were global fitted in a nonlinear least-squares fitting procedure, and precise molecular constants （Bv, Av, Dv, pv, qv, γv） were obtained for the involved levels.
基金Project supported by the National Natural Science Foundation of China(No.30670392)the Knowledge Innovation Program of the Chinese Academy of Sciences(Nos.KZCX2-YW-432 and KSCX2-SW-133)
文摘The effects of simulated nitrogen(N)deposition on soil exchangeable cations were studied in three forest types of subtropical China.Four N treatments with three replications were designed for the monsoon evergreen broadleaf forest (mature forest):control(0 kg N ha-1 year-1),low N(50 kg N ha-1 year-1),medium N(100 kg N ha-1 year-1)and high N(150 kg N ha-1 year-1),and only three treatments(i.e.,control,low N,medium N)were established for the pine and mixed forests.Nitrogen had been applied continuously for 26 months before the measurement.The mature forest responded more rapidly and intensively to N additions than the pine and mixed forests,and exhibited some significant negative symptoms,e.g.,soil acidification,Al mobilization and leaching of base cations from soil.The pine and mixed forests responded slowly to N additions and exhibited no significant response of soil cations.Response of soil exchangeable cations to N deposition varied in the forests of subtropical China,depending on soil N status and land-use history.
基金Supported by the Innovation Fund of Tianjin University
文摘A new reactive and extractive distillation process with ionic liquids as entrainer and catalyst （RED-IL）was proposed to produce methanol and n-butyl acetate by transesterification reaction of methyl acetate with n-butanol. The RED-IL process was simulated via a rigorous model, and high purity products of methanol and n-butyl acetate can be obtained in such a process. The effects of reflux ratio, feed mode, holdup, feed location, entrainer ratio and catalyst concentration on RED-IL process were investigated. The conversion of methyl acetate and purities of products increase with the holdup in column, entrainer ratio and catalyst content. An optimal reflux ratio exists in RED-IL process. Comparing to the mixed-feed mode, the segregated-feed mode is more effective, in which the optimal feed locations of reactants exist.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No.ISSASIP 0718)the National Natural Science Foundation of China (Nos.40401030 and 40871114)
文摘To investigate the interactions of oppositely charged sites on the surfaces of variable-charge soil particles with cations and anions, and to evaluate the mean Gibbs free binding and adsorption energies of various cations on particles of red soil and latosol, clay fractions smaller than 2 μm were separated from samples of the two variable-charge soils. Ferric oxides were removed from part of the clay fractions, which were then saturated with various chlorides （NaC1, KCl, CaCl2, CdCl2 or LaCl3）. Electrical conductivities （EC） of dilute suspensions of the original and of the iron oxides-free clay fractions in deionized water were measured with the SHP-2 short high-voltage pulse apparatus, which enables measurement of the Wien effect at field strengths （E） from 14 to 250 kV cm^-1. The Wien effect （EC-E） curves revealed EC increases of red soil suspensions between 14 and 200 kV cm^-1, of 8.3, 8.4, 12.1, 5.9, and 1.2 μS cm^-1 for NaCl, KCl, CaCl2, CdCl2, and LaCl3, respectively, reflecting the differing interactions with the various cations and chloride. The EC increments with the iron-free red soil suspensions were higher, being 29.7, 17.2, and 15.3 μS cm^-1 for NaCl, CaCl2, and CdCl2, respectively. In the natural latosol suspensions the EC increments were practically zero, whereas in the iron-free fractions there were significant EC increments of 10.3, 5.7, 5.0, and 1.6μS cm^-1 for NaCl, CaCl2, CdCl2, and LaCl3, respectively.
基金Project supported by the State of Sao Paulo Research Foundation-FAPESP, Brazil (No. 98/01502-8).
文摘The remaining phosphorus (Prem), P concentration that remains in solution after shaking soil with 0.01 mol L-1 CaCl2 containing 60μg mL-1 P, is a very useful index for studies related to the chemistry of variable charge soils. Although the Prem determination is a simple procedure, the possibility of estimating accurate values of this index from easily and/or routinely determined soil properties can be very useful for practical purposes. The present research evaluated the Prem estimation through multiple regression analysis in which routinely determined soil chemical data, soil clay content and soil pH measured in 1 mol L-1 NaF (pHNaF) figured as Prem predictor variables. The Prem can be estimated with acceptable accuracy using the above-mentioned approach, and pHNaF not only substitutes for clay content as a predictor variable but also confers more accuracy to the Prem estimates.
文摘Ten seed borne fungi （Alternaria sp., Aspergillus sp., Aureobasidium sp., Cladosporium sp., Dreschslera sp., Penicillium sp., Rhizoctonia sp., Stemphylium sp., Mueor sp. and Rhizopus sp.） were isolated and identified from two wheat varieties, the highest frequency of seed borne fungi was observed on wheat cultivar site Moll4 Alternaria sp.. Their mean and standard deviation was （5.5 ~ 1.69） while the lowest frequency fungal isolated was Dreschslera sp. and Rhizopus sp.. Their mean and standard deviation was （0.1 ~ 0.64）. The aflatoxin-producing isolates appeared as gray or black colonies in the UV photographs, whereas nonproducing isolates appeared as white colonies, the plate five colony four （P5CO4） showed the positive results which means the presence of aflatoxin as compaired to the control which showed the ngative results. Ammonium Hydroxide Vapor-Induced Color Change method used which the dish was inverted and 1 or 2 drops of concentrated ammonium hydroxide solution are placed on the inside of the lid. The undersides of aflatoxin-producing colonies quickly turn plum-red after the bottom of the Petri dish has been inverted over the lid containing the ammonium hydroxide aspositive result in （P5CO4） and （P7CO4） observed. Essentially no color change occurs on the undersides of colonies that are not producing aflatoxinsthis indicate to the negative results （control）. The main objective of this study is to isolation, identification and rapid detection of aflatoxin from wheat seed borne fungi.
基金The project supported by National Fundamental Research Program of China under Grant No. 2005CB724508 and National Natural Science Foundation of China under Grant Nos. 60478029, 90503010, and 10575040 .We would like to thank enlightening discussions professor Wu Ying for many
文摘In this paper, a procedure is proposed for measuring Wigner characteristic function for motion of a single trapped ion. In the scheme, the trapped ion is driven by two laser beams with different frequencies tuned to the first lower and upper vibrational sidebands, respectively. Unlike other previous scheme, our scheme does not require the displacement of the external state before the ion-laser interaction and thus our scheme night be more simple and feasible. The scheme can also be used to prepare the motional Schroedinger cat states and entangled coherent states.
基金financial support of the organizing committee of the International Conference on Salt Lake Research which facilitated their attendance at the 12 th conference,held during July 2014 in Langfang near Beijing,China
文摘Many lakes in Southeastern Wisconsin(the metropolitan-Milwaukee area) are gradually becoming increasingly "salty".While these waterbodies would not be considered presently to be saline lakes,there has been a rapid increase in the chloride concentrations in most of these lakes over the last 30 years,with the lakes increasing from a mean chloride concentration of about 19 mg/L to over 100 mg/L in some cases.While ecological impacts can be expected when chloride values exceed 250 mg/L,the rate of increase presents a basis for concern,especially since the underlying geology of the region is based on limestone/dolomite which is deficient in chlorides.Thus,the origin of the chlorides is anthropogenic:human and industrial wastewaters(treatment of which has effected improvements in trophic status but has not affected other water-borne contaminants) and winter de-icing practices based upon large quantities of sodium chloride are major contributors to the increasing concentrations of chloride in the region's waterways.Without taking remedial measures,the rate of salinization is expected to continue to increase,resulting,ultimately,in the alteration of the freshwater systems in the region.
文摘The critical properties of the bond-diluted mixed spin-1/2 and spin-1 transverse Ising system with singleion anisotropy are investigated by means of the effective field theory with correlations. Particular emphasis is given to the square lattice for which phase diagrams are obtained. If transverse field varies in the certain ranges we find that the tricritical point is obtained for the value of the bond concentration in a restricted region. We also observe that the reentrant phase transition may occur in the present system if single-ion anisotropy parameter is not large and if transverse field is small. On the other hand, for certain values of the system parameters, new induced magnetic ordering can be obtained. We find a number of interesting phenomena that are not predicted by previous literatures. The influence of the transverse field on the behaviours of the reentrant phase transition and induced magnetic ordering is discussed. A detailed description of the phase transition is presented.
