Charge-transfer salt (dbtf),HGeW12O40. 4H2O(C84H57O44S24GeW12)was synthesized by electrocrystallization and characterized by IR and electronic spectra.Its magnetic and conducting properties and crystal structure were ...Charge-transfer salt (dbtf),HGeW12O40. 4H2O(C84H57O44S24GeW12)was synthesized by electrocrystallization and characterized by IR and electronic spectra.Its magnetic and conducting properties and crystal structure were determined. The titlesalt crystallized in triclinic system with P1 space group. Its cell parameters are reflexions展开更多
We investigated the interaction between DNA and hexammine cobalt III [Co（NH3）6]3＋ by a simple molecular combing method and dynamic light scattering. The average extension of A- DNA-YOYO-1 complex is found to be 20....We investigated the interaction between DNA and hexammine cobalt III [Co（NH3）6]3＋ by a simple molecular combing method and dynamic light scattering. The average extension of A- DNA-YOYO-1 complex is found to be 20.9μm, about 30% longer than the contour length of the DNA in TE buffer （10 mmol/L Tris, 1 mmol/L EDTA, pH=8.0）, due to bis-intercalation of YOYO-1. A multivalent cation, hexammine cobalt, is used for DNA condensation. We find that the length of DNA-[Co（NH3）6]3＋ complexes decrease from 20.9 μm to 5.9μm as the concentration of the [Co（NH3）6]3＋ vary from 0 to 3 μmol/L. This observation provides a direct visualization of single DNA condensation induced by hexammine cobalt. The results from the molecular combing studies are supported by dynamic light scattering investigation, where the average hydrodynamic radius of the DNA complex decreases from 203.8 nm to 39.26 nm under the same conditions. It shows that the molecular combing method is feasible for quantitative conformation characterization of single bio-macromolecules.展开更多
Crystal of H14C[A-β-SiW9Al3(H2O)2O36(μ3-O2/2)]2 ·8H2O belongs to monoclinic system, space group P2/m. with a= 1 7. 525(6), b=14.348(3). c= 21. 669(8) A , β=113. 12(8)°, V = 5011 (3) A3,Z = 2. Dc = 3. 254 ...Crystal of H14C[A-β-SiW9Al3(H2O)2O36(μ3-O2/2)]2 ·8H2O belongs to monoclinic system, space group P2/m. with a= 1 7. 525(6), b=14.348(3). c= 21. 669(8) A , β=113. 12(8)°, V = 5011 (3) A3,Z = 2. Dc = 3. 254 g. cm-3, A (MoKα) = 0. 70169 A , μ=223. 21 cm-1, F(000) = 4614, T = 298K. R=0. 066 for 3010 unique reflections [I≥5σ(I) ]. The crystal consists of water molecules, protons (or H3O+ ) and dimeric anions [A-β-SiW9Al3 (H2O)2O36(μ3-O2/2)D214.the half of which has a SiO1 tetrahedron in the center, a W3O13 group, two W2Al(H2O) O12 groups and a W2AlO13 group around the SiO4.展开更多
Electron paramagnetic resonance and electron-nuclear double resonance methods were used to study the polycyclic aromatic radical cations produced in a Friedel-Crafts alkylating sys- tem, with m-xylene, or p-xylene and...Electron paramagnetic resonance and electron-nuclear double resonance methods were used to study the polycyclic aromatic radical cations produced in a Friedel-Crafts alkylating sys- tem, with m-xylene, or p-xylene and alkyl chloride. The results indicate that the observed electron paramagnetic resonance spectra are due to polycyclic aromatic radicals formed from the parent hydrocarbons. It is suggested that benzyl halides produced in the Friedel-Crafts alkylation reactions undergo Scholl self-condensation to give polycyclic aromatic hydrocar- bons, which are converted into corresponding polycyclic aromatic radical cations in the presence of AlCl3. The identification of observed two radicals 2,6-dimethylanthracene and 1,4,5,8-tetramethylanthraeene were supported by density functional theory calculations using the B3LYP/6-31G（d,p）//B3LYP/6-31G（d） approach. The theoretical coupling constants support the experimental assignment of the observed radicals.展开更多
The present study aimed to determine the mechanism of cation-selective secretion by multicellular salt glands.Using a hydroponic culture system,the secretion and accumulation of Na+ and K+ in Tamarix ramosissima and T...The present study aimed to determine the mechanism of cation-selective secretion by multicellular salt glands.Using a hydroponic culture system,the secretion and accumulation of Na+ and K+ in Tamarix ramosissima and T.laxa under different salt stresses (NaCl,KCl and NaCl+KCl) were studied.Additionally,the effects of salt gland inhibitors (orthovanadate,Ba2+,ouabain,tetraethylammonium (TEA) and verapamil) on Na+ and K+ secretion and accumulation were examined.Treatment with NaCl (at 0-200 mmol L 1 levels) significantly increased Na+ secretion,whereas KCl treatment (at 0-200 mmol L 1 levels) significantly increased K+ secretion.The ratio of secretion to accumulation of Na+ was higher than that of K+.The changes in Na+ and K+ secretion differed after adding different ions into the single-salt solutions.Addition of NaCl to the KCl solution (at 100 mmol L 1 level,respectively) led to a significant decrease in K+ secretion rate,whereas addition of KCl to the NaCl solution (at 100 mmol L 1 level,respectively) had little impact on the Na+ secretion rate.These results indicated that Na+ secretion in Tamarix was highly selective.In addition,Na+ secretion was significantly inhibited by orthovanadate,ouabain,TEA and verapamil,and K+ secretion was significantly inhibited by ouabain,TEA and verapamil.The different impacts of orthovanadate on Na+ and K+ secretion might be the primary cause for the different Na+ and K+ secretion abilities of multicellular salt glands in Tamarix.展开更多
DNA persistence length is a key parameter for quantitative interpretation of the conformational properties of DNA and related to the bending rigidity of DNA.A series of experiments pointed out that,in the DNA condensa...DNA persistence length is a key parameter for quantitative interpretation of the conformational properties of DNA and related to the bending rigidity of DNA.A series of experiments pointed out that,in the DNA condensation process by multivalent cations,the condensed DNA takes elongated coil or compact globule states and the population of the compact globule states increases with an increase in ionic concentration.At the same time,single molecule experiments carried out in solution with multivalent cations(such as spermidine,spermine)indicated that DNA persistence length strongly depends on the ionic concentration.In order to revolve the effects of ionic concentration dependence of persistence length on DNA condensation,a model including the ionic concentration dependence of persistence length and strong correlation of multivalent cation on DNA is provided.The autocorrelation function of the tangent vectors is found as an effective way to detect the ionic concentration dependence of toroidal conformations.With an increase in ion concentration,the first periodic oscillation contained in the autocorrelation function shifts,the number of segment contained in the first periodic oscillation decreases gradually.According to the experiments,the average long-axis length is defined to estimate the ionic concentration dependence of condensation process further.The relation between long-axis length and ionic concentration matches the experimental results qualitatively.展开更多
Lithium-sulfur(Li-S) battery is a promising choice for the next generation of high-energy rechargeable batteries, but its application is impeded by the high dissolution of the polysulfides in commonly used organic ele...Lithium-sulfur(Li-S) battery is a promising choice for the next generation of high-energy rechargeable batteries, but its application is impeded by the high dissolution of the polysulfides in commonly used organic electrolyte. Room temperature ionic liquids(RTILs) have been considered as appealing candidates for the electrolytes in Li-S batteries. We investigated the effect of cations in RTILs on the electrochemical performance for Li-S batteries. Ex situ investigation of lithium anode for Li-S batteries indicates that during the discharge/charge process the RTIL with N-methyl-N-propylpyrrolidine cations(P13) can effectively suppress the dissolution of the polysulfides, whereas the RTIL with 1-methyl-3-propyl imidazolium cation(PMIM) barely alleviates the shuttling problem. With 0.5 mol L-1 LiTFSI/P13 TFSI as the electrolyte of Li-S battery, the ketjen black/ sulfur cathode material exhibits high capacity and remarkable cycling stability, which promise the application of the P13-based RTILs in Li-S batteries.展开更多
文摘Charge-transfer salt (dbtf),HGeW12O40. 4H2O(C84H57O44S24GeW12)was synthesized by electrocrystallization and characterized by IR and electronic spectra.Its magnetic and conducting properties and crystal structure were determined. The titlesalt crystallized in triclinic system with P1 space group. Its cell parameters are reflexions
文摘We investigated the interaction between DNA and hexammine cobalt III [Co（NH3）6]3＋ by a simple molecular combing method and dynamic light scattering. The average extension of A- DNA-YOYO-1 complex is found to be 20.9μm, about 30% longer than the contour length of the DNA in TE buffer （10 mmol/L Tris, 1 mmol/L EDTA, pH=8.0）, due to bis-intercalation of YOYO-1. A multivalent cation, hexammine cobalt, is used for DNA condensation. We find that the length of DNA-[Co（NH3）6]3＋ complexes decrease from 20.9 μm to 5.9μm as the concentration of the [Co（NH3）6]3＋ vary from 0 to 3 μmol/L. This observation provides a direct visualization of single DNA condensation induced by hexammine cobalt. The results from the molecular combing studies are supported by dynamic light scattering investigation, where the average hydrodynamic radius of the DNA complex decreases from 203.8 nm to 39.26 nm under the same conditions. It shows that the molecular combing method is feasible for quantitative conformation characterization of single bio-macromolecules.
文摘Crystal of H14C[A-β-SiW9Al3(H2O)2O36(μ3-O2/2)]2 ·8H2O belongs to monoclinic system, space group P2/m. with a= 1 7. 525(6), b=14.348(3). c= 21. 669(8) A , β=113. 12(8)°, V = 5011 (3) A3,Z = 2. Dc = 3. 254 g. cm-3, A (MoKα) = 0. 70169 A , μ=223. 21 cm-1, F(000) = 4614, T = 298K. R=0. 066 for 3010 unique reflections [I≥5σ(I) ]. The crystal consists of water molecules, protons (or H3O+ ) and dimeric anions [A-β-SiW9Al3 (H2O)2O36(μ3-O2/2)D214.the half of which has a SiO1 tetrahedron in the center, a W3O13 group, two W2Al(H2O) O12 groups and a W2AlO13 group around the SiO4.
文摘Electron paramagnetic resonance and electron-nuclear double resonance methods were used to study the polycyclic aromatic radical cations produced in a Friedel-Crafts alkylating sys- tem, with m-xylene, or p-xylene and alkyl chloride. The results indicate that the observed electron paramagnetic resonance spectra are due to polycyclic aromatic radicals formed from the parent hydrocarbons. It is suggested that benzyl halides produced in the Friedel-Crafts alkylation reactions undergo Scholl self-condensation to give polycyclic aromatic hydrocar- bons, which are converted into corresponding polycyclic aromatic radical cations in the presence of AlCl3. The identification of observed two radicals 2,6-dimethylanthracene and 1,4,5,8-tetramethylanthraeene were supported by density functional theory calculations using the B3LYP/6-31G（d,p）//B3LYP/6-31G（d） approach. The theoretical coupling constants support the experimental assignment of the observed radicals.
基金supported by the Special Fund for Public Welfare Industrial(Agriculture) Research of China(Grant No. 200903001)Chinese Academy of Sciences Innovation Base Project for Agriculture(Grant No. KSCX1-YW-09-10),the Chinese Academy of Sciences Agricultural Projects (Grant No. KSCX2-YW-N-41)
文摘The present study aimed to determine the mechanism of cation-selective secretion by multicellular salt glands.Using a hydroponic culture system,the secretion and accumulation of Na+ and K+ in Tamarix ramosissima and T.laxa under different salt stresses (NaCl,KCl and NaCl+KCl) were studied.Additionally,the effects of salt gland inhibitors (orthovanadate,Ba2+,ouabain,tetraethylammonium (TEA) and verapamil) on Na+ and K+ secretion and accumulation were examined.Treatment with NaCl (at 0-200 mmol L 1 levels) significantly increased Na+ secretion,whereas KCl treatment (at 0-200 mmol L 1 levels) significantly increased K+ secretion.The ratio of secretion to accumulation of Na+ was higher than that of K+.The changes in Na+ and K+ secretion differed after adding different ions into the single-salt solutions.Addition of NaCl to the KCl solution (at 100 mmol L 1 level,respectively) led to a significant decrease in K+ secretion rate,whereas addition of KCl to the NaCl solution (at 100 mmol L 1 level,respectively) had little impact on the Na+ secretion rate.These results indicated that Na+ secretion in Tamarix was highly selective.In addition,Na+ secretion was significantly inhibited by orthovanadate,ouabain,TEA and verapamil,and K+ secretion was significantly inhibited by ouabain,TEA and verapamil.The different impacts of orthovanadate on Na+ and K+ secretion might be the primary cause for the different Na+ and K+ secretion abilities of multicellular salt glands in Tamarix.
基金Supported by National Natural Science Foundation of China under Grant Nos.11047022,11204045,11464004 and 31360215The Research Foundation from Ministry of Education of China(212152)+4 种基金Guizhou Provincial Tracking Key Program of Social Development(SY20123089SZ20113069)The General Financial Grant from the China Postdoctoral Science Foundation(2014M562341)The Research Foundation for Young University Teachers from Guizhou University(201311)The West Light Foundation(2015)and College Innovation Talent Team of Guizhou Province,(2014)32
文摘DNA persistence length is a key parameter for quantitative interpretation of the conformational properties of DNA and related to the bending rigidity of DNA.A series of experiments pointed out that,in the DNA condensation process by multivalent cations,the condensed DNA takes elongated coil or compact globule states and the population of the compact globule states increases with an increase in ionic concentration.At the same time,single molecule experiments carried out in solution with multivalent cations(such as spermidine,spermine)indicated that DNA persistence length strongly depends on the ionic concentration.In order to revolve the effects of ionic concentration dependence of persistence length on DNA condensation,a model including the ionic concentration dependence of persistence length and strong correlation of multivalent cation on DNA is provided.The autocorrelation function of the tangent vectors is found as an effective way to detect the ionic concentration dependence of toroidal conformations.With an increase in ion concentration,the first periodic oscillation contained in the autocorrelation function shifts,the number of segment contained in the first periodic oscillation decreases gradually.According to the experiments,the average long-axis length is defined to estimate the ionic concentration dependence of condensation process further.The relation between long-axis length and ionic concentration matches the experimental results qualitatively.
基金supported by the"Strategic Priority Research Program"of the Chinese Academy of Sciences(XDA09010300)the National Natural Science Foundation of China(51225204,91127044,U1301244,21121063)+1 种基金the National Basic Research Program of China(2011CB935700,2012CB932900)the Chinese Academy of Sciences
文摘Lithium-sulfur(Li-S) battery is a promising choice for the next generation of high-energy rechargeable batteries, but its application is impeded by the high dissolution of the polysulfides in commonly used organic electrolyte. Room temperature ionic liquids(RTILs) have been considered as appealing candidates for the electrolytes in Li-S batteries. We investigated the effect of cations in RTILs on the electrochemical performance for Li-S batteries. Ex situ investigation of lithium anode for Li-S batteries indicates that during the discharge/charge process the RTIL with N-methyl-N-propylpyrrolidine cations(P13) can effectively suppress the dissolution of the polysulfides, whereas the RTIL with 1-methyl-3-propyl imidazolium cation(PMIM) barely alleviates the shuttling problem. With 0.5 mol L-1 LiTFSI/P13 TFSI as the electrolyte of Li-S battery, the ketjen black/ sulfur cathode material exhibits high capacity and remarkable cycling stability, which promise the application of the P13-based RTILs in Li-S batteries.
