The addition of complexing agents to the electrolyte has been shown to be an effective method to enhance the discharge performance of magnesium-air batteries.In this work,four complexing agents:citric acid(CIT),salicy...The addition of complexing agents to the electrolyte has been shown to be an effective method to enhance the discharge performance of magnesium-air batteries.In this work,four complexing agents:citric acid(CIT),salicylic acid(SAL),2,6-dihydroxybenzoic acid(2,6-DHB),and 5-sulfoisophthalic acid(5-sulfoSAL)were selected as potential candidates.Through electrochemical tests,full-cell discharge experiments,and physicochemical characterization,the impact of these complexing agents on the discharge performance of magnesium-air batteries using AZ31 alloy as the anode material was investigated.The results demonstrated that the four complexing agents increased the discharge voltage of the batteries.Notably,SAL could significantly improve the anodic efficiency and the discharge specific capacity,achieving an anodic efficiency of 60.3%and a specific capacity of 1358.3 mA·h/g at a discharge current density of 10 mA/cm^(2).展开更多
Light conversion agents Eul-xLx（TTA）3Phen (L denotes (La3+, Gd3+, Y3+)) complexes were prepared, and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluoresc...Light conversion agents Eul-xLx（TTA）3Phen (L denotes (La3+, Gd3+, Y3+)) complexes were prepared, and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluorescent spectra. The results show that FTIR spectra of Eul-xLx（TTA）3Phen complex system are identical with that of EuTTA3Phen, which indicates that the complexes (Eul-xLx（TTA）3Phen) are similar in structure to （Eu （TTA）3Phen.） For the above doping elements, co-fluorescence enhancement has the following order: Gd3+>Y3+>La3+, and the optimum mole fractions of doping elements are 0.4, 0.2 and 0.5 respectively for Gd3+, Y3+, La3+. Among all the complexes, Eu0.6Gd0.4（TTA）3Phen complex has the strongest fluorescent intensity. Applying Eu0.6Gd0.4（TTA）3Phen complex to plastic and printing inks, bright red fluorescence plastic and printing inks are obtained when the content of europium reaches 0.1%（mass fraction）.展开更多
Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agent...Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agents on EN deposition rate and the stability of solution pH values were examined, either with an acetic pH buffer agent or absent of them. It is indicated that the pH buffeting effect of them is dominative when the EN solution is lack of the pH buffer. Under this situation, the EN deposition rate increases with the concentration of complexing agents increasing. The EN deposition rate decreases with fin＇ther adding the complexing agent when the solution already has enough pH buffer capability. Electrochemical impedance spectroscopy obtained during EN deposition illustrates that, in this case, the enhanced reaction resistance is the main reason for a lower deposition rate. However, the influence of polarization caused by mass transfer is not negligible at high complex ratio for sodium citrate and malic acid EN solutions.展开更多
Three novel rare earth complexes, [Ln2（DCA）2（phen）2]（NO3）2·6H2O （Ln（III）=Sm（III）（1）, Er（III）（2）, Yb（III）（3）; DCA2–=de-methylcantharate, 7-oxabicyclo[2.2.1] heptane-2,3-dicarboxylate, C8H8O52...Three novel rare earth complexes, [Ln2（DCA）2（phen）2]（NO3）2·6H2O （Ln（III）=Sm（III）（1）, Er（III）（2）, Yb（III）（3）; DCA2–=de-methylcantharate, 7-oxabicyclo[2.2.1] heptane-2,3-dicarboxylate, C8H8O52–; phen=1,10-phenanthroline, C12H8N2） were synthesized. The structures were characterized by elemental analysis, molar conductance, IR and TGA. The results suggested that the structural features of the complexes were： in each DCA2–, one carboxylate group, as bidentate bridging group, connected two rare earth ions; the other carboxylate group, as bidentate chelate group took part in the coordination with rare earth ion. And cyclic ether oxygen of DCA2– and nitrogen atoms of phen took part in the coordination. The probable coordination number was seven. The interaction of the complexes with DNA was studied by UV-spectra, fluorescence spectra and viscosity measurements. Following increasing the concentration of DNA, the UV absorption bands nearby 265 nm of the three complexes appeared hypochromism and red-shift phenomena. And the values of binding constants Kb were 1.89×105 L/mol （1）, 3.54×104 L/mol （2） and 3.83×104 L/mol （3）. The complexes could quench the fluorescence of EB-DNA system, and the values of equilibrium constants Ksq were 1.72（1）, 0.56（2） and 1.09（3）. The relative viscosity of DNA steadily decreased with increasing the concentration of complexes. So, we could infer that the complexes may partially insert into DNA. The study of agarose gel electrophoresis showed that the complexes could cleave plasmid DNA, and the process of the reaction was through unclassical redox mechanism.展开更多
Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS（NH2）2, S2O2-3 and SCN- ...Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS（NH2）2, S2O2-3 and SCN- systems, alkaline thiourea is the optimal nontoxic lixiviating agent substituting cyanide from the viewpoint of thermodynamics. The electrochemical study indicates that the anodic dissolution current densities of gold are 2.616, （1.805,） 1.267, 1.088, 0.556, and 0.145 mA·cm-2 respectively in the solutions of cyanide, alkaline thiourea containing Na2SiO3, SCN-, acidic thiourea, alkaline thiourea and thiosulfate at the potential of 0.500 V. Comparing various lixiviating agents, the alkaline thiourea solution containing Na2SiO3 is of prominent selectivity in leaching gold, in the potential range from 0.500 to 0.600 V, which is most efficient for leaching gold selectively instead of cyanide. The effect on leaching gold is similar to that in the cyanide system.展开更多
A cobalt（11） complex containing mixed-ligands of 1,10-phenathroline（phen） and glycollic acid（GA）.｜Co（GA）_2（phen）｜ was synthesized and its structure was characterized by X-ray diffraction.The interaction of...A cobalt（11） complex containing mixed-ligands of 1,10-phenathroline（phen） and glycollic acid（GA）.｜Co（GA）_2（phen）｜ was synthesized and its structure was characterized by X-ray diffraction.The interaction of the complex with DNA was investigated by electronic absorption spectra and electrochemical methods.Electronic absorption spectrum experiments showed that after interaction with DNA.the characteristic absorption peaks of ｜Co（GA）_2（phen）｜ underwent hypochromic effect as well as redshift. Also,the binding strength of 3.8×10~4L/mol was estimated by titration method.Electrochemical assays revealed that the redox peak currents of the complex decreased obviously accompanied by a positive shift of the formal potential after association with DNA.All these results revealed that the synthesized cobalt complex bound with DNA via an intercalation mode.展开更多
The distribution of binding agents(i.e.,soil organic carbon(SOC)and glomalin-related soil protein(GRSP))in soil aggregates was influenced by many factors,such as plant characteristics and soil properties.However,how t...The distribution of binding agents(i.e.,soil organic carbon(SOC)and glomalin-related soil protein(GRSP))in soil aggregates was influenced by many factors,such as plant characteristics and soil properties.However,how these factors affect binding agents and soil aggregate stability along a climatic gradient remained unclear.We selected the Robinia pseudoacacia L.forests from semi-arid to semi-humid of the Loess Plateau,China to analyze the plant biomass,soil physical-chemical properties,SOC and GRSP distribution in different sized soil aggregates.We found that from semi-arid to semi-humid forests:(1)the proportion of macro-aggregates(>0.250 mm)significantly increased(P<0.05),whereas those of micro-aggregates(0.250–0.053 mm)and fine materials(<0.053 mm)decreased and soil aggregate stability was increased;(2)the contents of SOC and GRSP in macro-aggregates and micro-aggregates significantly increased,and those in fine materials decreased;(3)the contribution of SOC to soil aggregate stability was greater than those of total GRSP and easily extractable GRSP;(4)soil properties had greater influence on binding agents than plant biomass;and(5)soil aggregate stability was enhanced by increasing the contents of SOC and GRSP in macro-aggregates and soil property was the important part during this process.Climate change from semi-arid to semi-humid forests is important factor for soil structure formation because of its positive effect on soil aggregates.展开更多
At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to co...At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La（Ⅲ）,Pr（Ⅲ）, and Nd（Ⅲ） from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid（HLac） and auxiliary agents citric acid（H3 Cit）, acetic acid（HAc）, and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.展开更多
Urban forest soil is often disturbed by rapid urbanization. Organic mulching is effective for improving soil quality and aggregate stability. This study evaluated how soil binding agents changed aggregate stability th...Urban forest soil is often disturbed by rapid urbanization. Organic mulching is effective for improving soil quality and aggregate stability. This study evaluated how soil binding agents changed aggregate stability through organic mulching in urban forest soils. Three treatments were applied in Jiufeng National Forest Park, Beijing: (1) no organic mulch (control);(2) wood chips alone (5 cm thickness);and, (3) wood chips + wood compost (This mulch was divided into two layers, the upper layer of wood chips (2.5 cm), the lower layer wood compost (2.5 cm)). Soil samples were collected from the surface 10- cm soil layer and fraction into four aggregates. Glomalin-related soil protein and soil organic carbon were measured in bulk soil and the four aggregates. The results show that wood chips + wood compost increased the proportion of large and small macroaggregates, mean weight diameter and geometric mean diameter. The total and easily extractable glomalin-related soil protein were higher in the wood chips + wood compost. However, soil organic carbon was lower in the wood chips alone application compared to the controls and wood chips + wood compost. Easily extractable / total glomalin-related soil protein and glomalin-related soil protein / soil organic carbon ratios of wood chips alone and wood chips + wood compost had increased trend compared to the controls but did not reach significant levels (p > 0.05). Mean weight diameter and geometric mean diameter correlated positively with total and easily extractable glomalin-related soil protein but were not positively correlated with soil organic carbon, the ratios of easily extractable and total glomalin-related soil protein, and the ratios of glomalin-related soil protein and soil organic carbon. Redundancy analysis revealed that total glomalin-related soil protein was the most important driver for soil aggregate stability, especially the total glomalin-related soil protein of small macroaggregates. The results suggest that wood chips + wood compost enhanced soil aggregate stability through the increase of glomalin-related soil protein. Wood chips alone cannot enhance soil aggregate stability in urban forests in the short term.展开更多
The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. ...The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.展开更多
Two ligands 2,2＇-[2,3-naphthylenebis（oxy）]-bis（N-benzyl（acetamide））（L1） and 2,2＇-[2,3-naphthylenebis （oxy）]-bis（N,N-diphenyl （acetamide））（L2） and their europium（Ill） picrate complexes were synthesi...Two ligands 2,2＇-[2,3-naphthylenebis（oxy）]-bis（N-benzyl（acetamide））（L1） and 2,2＇-[2,3-naphthylenebis （oxy）]-bis（N,N-diphenyl （acetamide））（L2） and their europium（Ill） picrate complexes were synthesized. The complexes were characterized by elemental analysis, inf,- red （IR）, thermogravimetry and differential thermal analysis （TG-DTA） and molar conductivity. Fluorescent experiments showed that the resonance level of the Eu（III） matched better to the triplet state energy level of the ligand L2 than that of the ligand L1 and the fluorescence in- tensities of the complexes were reduced with the raising coordination ability of solvent. In addition, the interactions between the complexes and DNA were studied by means of spectrometry and cyclic voltammetry. The results suggested that the complexes could bind to DNA through intercalation and the complex 1 binded to DNA more strongly than the complex 2.展开更多
Tabular PE PbTiO 3, spherical PY PbTiO 3, and acicular PX PbTiO 3 powders were hydrothermally synthesized from triethanolamine(TEA) complexed precursor; clubbed PE PbTiO 3 powders were obtained from diethanol...Tabular PE PbTiO 3, spherical PY PbTiO 3, and acicular PX PbTiO 3 powders were hydrothermally synthesized from triethanolamine(TEA) complexed precursor; clubbed PE PbTiO 3 powders were obtained from diethanolamine(DEA) complexed precursor. The effects of pH of the hydrolyzation as well as complexing agents including TEA, DEA, and MEA(monoethanolamine) on the structure and the morphology of PbTiO 3 powders are discussed. The optimal conditions for hydrothermal syntheses of acicular and clubbed PbTiO 3 powders have been established. The products were characterized by means of XRD, TEM and other techniques.展开更多
Gadolinium diethylenetriamine-pentaacetic bisdopamide （Gd-DTPA-2DA） was synthesized by the incorporation of dopamine to diethylenetriaminepentaacetic acid （DTPA） and further reaction with gadolinium chloride. In v...Gadolinium diethylenetriamine-pentaacetic bisdopamide （Gd-DTPA-2DA） was synthesized by the incorporation of dopamine to diethylenetriaminepentaacetic acid （DTPA） and further reaction with gadolinium chloride. In vitro and in vivo properties were also evaluated. Gadolinium complex Gd-DTPA-2DA possessed higher relaxation effectiveness and less cytotoxicity to HeLa cells than that of Gd-DTPA. Moreover, Gd-DTPA-2DA greatly enhanced the contrast of MR images of the brains, provided prolonged intravascular duration, and pro- duced highly contrasted visualization of the brain.展开更多
After gas drainage, the outburst seam is dry and, consequently, during subsequent mechanized mining, unwanted dust production is extensive. Because the hard dustfall typically has a small particle size it contains a h...After gas drainage, the outburst seam is dry and, consequently, during subsequent mechanized mining, unwanted dust production is extensive. Because the hard dustfall typically has a small particle size it contains a high percentage of respirable dust. Considering these factors, this paper improved the efficiency of dustfall by reducing the surface tension of the liquid used as a wetting agent, then configuring five kinds of wetting agents by adopting various doses and types of surfactants, neutral inorganic salts and chemical additives, etc. After purchasing DA-85 and SRJ-1 wetting agent, the surface tension and critical micelle concentration of seven kinds of wetting agents were measured using the capillary rise method. Wetting agent A was confirmed to have the best comprehensive effect. The experiments were optimized by measuring and comparatively analyzing contact angles of pure water, SRJ-1 wetting agent and wetting agent A on the surface of different coal samples using a contact angle measurement instrument （HARKE- SPCA）. By comparative analysis, dust-proof effects of seam, dynamic pressure water infusion and high- pressure spray in the tunneling face at the Daning coal mine using pure water, wetting agent SRJ-1 and A, it was determined that after using wetting agent A, the average dust concentration in the place of the mining machine driver, 10 m and 110 m away from the tunneling front is approximately 300 rag/ m^3, 240 mg/m^3 and 100 mg/m^3, respectively, This practice increased the dust-proof efficiency dramati- cally and achieved a good comprehensive dust-proof effect.展开更多
Three fluorescent BINOL-Si complexes(FS1,FS2 and FS3)were rationally designed and synthesized to detect diethyl chlorophosphate(DCP),a mimic of lethal nerve agents.These three fluorescent probes showed green,yellow an...Three fluorescent BINOL-Si complexes(FS1,FS2 and FS3)were rationally designed and synthesized to detect diethyl chlorophosphate(DCP),a mimic of lethal nerve agents.These three fluorescent probes showed green,yellow and orange fluorescence,respectively.Moreover,the series of fluorescent probes has the characteristics of fast response time(4 s),low detection limit(0.0097 mmol/L),high sensitivity and naked eye detection.More important,a fiber optic sensor capable of detecting DCP vapor in real time was also prepared for the first time,the lowest detection limits(down to 4.4 ppb)were all lower than that of the IDLH(immediately dangerous to life or health)concentration of Sarin(7.0 ppb).展开更多
A copper-bispyridylpyrrolide complex [Cu(PDPH)Cl](PDPH = 2,5-bis(2′-pyridyl)pyrrole) was synthesized and characterized. The complex crystallizes in the orthorhombic system with space group Pccn, a = 0.9016(3) nm, b =...A copper-bispyridylpyrrolide complex [Cu(PDPH)Cl](PDPH = 2,5-bis(2′-pyridyl)pyrrole) was synthesized and characterized. The complex crystallizes in the orthorhombic system with space group Pccn, a = 0.9016(3) nm, b = 1.0931(4) nm, c =2.5319(8) nm, and V = 2.4951(15) nm3. The copper center is situated in a square planar geometry. The interaction of the copper(II)complex with calf thymus DNA(CT-DNA) was investigated by electronic absorption, circular dichroism(CD) and fluorescence spectra. It is proposed that the complex binds to CT-DNA through groove binding mode. Nuclease activity of the complex was also studied by gel electrophoresis method. The complex can efficiently cleave supercoiled p BR322 DNA in the presence of ascorbate(H2A) via oxidative pathway. The preliminary mechanism of DNA cleavage by the complex with different inhibiting reagents indicates that the hydroxyl radicals were involved as the active species in the DNA cleavage process.展开更多
A new cobalt(Ⅱ) complex with tridentate ligand 2, 6-bis (benzimidazol- 2-yl)pyridine has been synthesized by microwave irradiation method and characterized by elemental analysis, electrochemical and spectral methods....A new cobalt(Ⅱ) complex with tridentate ligand 2, 6-bis (benzimidazol- 2-yl)pyridine has been synthesized by microwave irradiation method and characterized by elemental analysis, electrochemical and spectral methods. The binding of the complex with calf thymus DNA has also been investigated by absorption and fluorescence spectra.展开更多
Two silver（I）-sulfonate complexes,[Ag（NO3）（4,4＇-bipy）][Ag（HL）（4,4＇-bipy）]·2H2O（1） and[Ag（H2O）（4,4＇-bipy）][AgL（4,4＇-bipy）]·2H2O（2）,have been synthesized by in situ reaction（H2L = 2-fo...Two silver（I）-sulfonate complexes,[Ag（NO3）（4,4＇-bipy）][Ag（HL）（4,4＇-bipy）]·2H2O（1） and[Ag（H2O）（4,4＇-bipy）][AgL（4,4＇-bipy）]·2H2O（2）,have been synthesized by in situ reaction（H2L = 2-formylbenzenesulfonic acid,4,4-bipy = 4,4-bipyridine）.1 displays two parallel 1D chains expending to a 3D supramolecule by n—n interactions and O-H…O hydrogen bonds,in which the[Ag（NO3）]or[Ag（HL）]units are joined by bridging 4,4＇-bipy molecules,respectively.The interactions between the complexes and DNA were studied by means of fluorescence spectra and surface-enhanced Raman scattering（SERS） spectra.The special configuration and intercalation effects between 1 and DNA are stronger than that between 2 and DNA.展开更多
A complex [Cd2Na2（BOABA）2（H2O）8]·H2O（1） was synthesized by using 2,4-bisoxyacetate-benzoic acid（H3BOABA） and Cd（OH）2. It was characterized by elemental analysis, IR spectra, and single-crystal X-ray dif...A complex [Cd2Na2（BOABA）2（H2O）8]·H2O（1） was synthesized by using 2,4-bisoxyacetate-benzoic acid（H3BOABA） and Cd（OH）2. It was characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complex 1 shows a two-dimensional 3-connected rigid plane. The interactions between the ligand and its complex with DNA were studied by Et Br fluorescence probe. Photoluminescent studies indicate that the complex may be excellent candidates for potential photoactive materials.展开更多
The adsorption of rare earths,lanthanum,cerium,neodymium,and yttri um by di(2-ethylhexyl) phosphoric acid(D2EHPA) resin in the presence of a compl exing agent,EDTA,was investigated. Flow injection was selected as the ...The adsorption of rare earths,lanthanum,cerium,neodymium,and yttri um by di(2-ethylhexyl) phosphoric acid(D2EHPA) resin in the presence of a compl exing agent,EDTA,was investigated. Flow injection was selected as the injectin g method. Various parameters,sample pH,sample loading time,sample flow rate,EDTA concentration,EDTA flow rate,eluent concentration,and eluent flow rate,were studied and optimized. Under the optimum conditions,the method allowed the determination of rare earths with detection limits of 1.09 μg/L(lanthanum),3 .31 μg/L(cerium),2.05 μg/L(neodymium),and 1.25 μg/L(yttrium) . High repea tabilities were obtained for all the four rare earths(RSD【5%) . The proposed met hod was applied to the determination of the rare earths in water samples with a recovery range of 95.8%-103.3%.展开更多
基金supported by the National Natural Science Foundation of China(No.52001015)the Urban Carbon Neutral Science Innovation Foundation of Beijing University of Technology,China(No.053000514124601)the Science and Technology Program of Beijing Municipal Education Commission,China(No.KM201810005007).
文摘The addition of complexing agents to the electrolyte has been shown to be an effective method to enhance the discharge performance of magnesium-air batteries.In this work,four complexing agents:citric acid(CIT),salicylic acid(SAL),2,6-dihydroxybenzoic acid(2,6-DHB),and 5-sulfoisophthalic acid(5-sulfoSAL)were selected as potential candidates.Through electrochemical tests,full-cell discharge experiments,and physicochemical characterization,the impact of these complexing agents on the discharge performance of magnesium-air batteries using AZ31 alloy as the anode material was investigated.The results demonstrated that the four complexing agents increased the discharge voltage of the batteries.Notably,SAL could significantly improve the anodic efficiency and the discharge specific capacity,achieving an anodic efficiency of 60.3%and a specific capacity of 1358.3 mA·h/g at a discharge current density of 10 mA/cm^(2).
文摘Light conversion agents Eul-xLx（TTA）3Phen (L denotes (La3+, Gd3+, Y3+)) complexes were prepared, and the influence of doping ions on fluorescence properties was investigated by elementary analysis, FTIR and fluorescent spectra. The results show that FTIR spectra of Eul-xLx（TTA）3Phen complex system are identical with that of EuTTA3Phen, which indicates that the complexes (Eul-xLx（TTA）3Phen) are similar in structure to （Eu （TTA）3Phen.） For the above doping elements, co-fluorescence enhancement has the following order: Gd3+>Y3+>La3+, and the optimum mole fractions of doping elements are 0.4, 0.2 and 0.5 respectively for Gd3+, Y3+, La3+. Among all the complexes, Eu0.6Gd0.4（TTA）3Phen complex has the strongest fluorescent intensity. Applying Eu0.6Gd0.4（TTA）3Phen complex to plastic and printing inks, bright red fluorescence plastic and printing inks are obtained when the content of europium reaches 0.1%（mass fraction）.
文摘Our previous study reported the influences of different complexing agents on electroless nickel （EN） by examining the properties of the deposits. In the present work, the effects of four common-used complexing agents on EN deposition rate and the stability of solution pH values were examined, either with an acetic pH buffer agent or absent of them. It is indicated that the pH buffeting effect of them is dominative when the EN solution is lack of the pH buffer. Under this situation, the EN deposition rate increases with the concentration of complexing agents increasing. The EN deposition rate decreases with fin＇ther adding the complexing agent when the solution already has enough pH buffer capability. Electrochemical impedance spectroscopy obtained during EN deposition illustrates that, in this case, the enhanced reaction resistance is the main reason for a lower deposition rate. However, the influence of polarization caused by mass transfer is not negligible at high complex ratio for sodium citrate and malic acid EN solutions.
基金supported by the Natural Science Foundation of Zhejiang Province (Y407301)
文摘Three novel rare earth complexes, [Ln2（DCA）2（phen）2]（NO3）2·6H2O （Ln（III）=Sm（III）（1）, Er（III）（2）, Yb（III）（3）; DCA2–=de-methylcantharate, 7-oxabicyclo[2.2.1] heptane-2,3-dicarboxylate, C8H8O52–; phen=1,10-phenanthroline, C12H8N2） were synthesized. The structures were characterized by elemental analysis, molar conductance, IR and TGA. The results suggested that the structural features of the complexes were： in each DCA2–, one carboxylate group, as bidentate bridging group, connected two rare earth ions; the other carboxylate group, as bidentate chelate group took part in the coordination with rare earth ion. And cyclic ether oxygen of DCA2– and nitrogen atoms of phen took part in the coordination. The probable coordination number was seven. The interaction of the complexes with DNA was studied by UV-spectra, fluorescence spectra and viscosity measurements. Following increasing the concentration of DNA, the UV absorption bands nearby 265 nm of the three complexes appeared hypochromism and red-shift phenomena. And the values of binding constants Kb were 1.89×105 L/mol （1）, 3.54×104 L/mol （2） and 3.83×104 L/mol （3）. The complexes could quench the fluorescence of EB-DNA system, and the values of equilibrium constants Ksq were 1.72（1）, 0.56（2） and 1.09（3）. The relative viscosity of DNA steadily decreased with increasing the concentration of complexes. So, we could infer that the complexes may partially insert into DNA. The study of agarose gel electrophoresis showed that the complexes could cleave plasmid DNA, and the process of the reaction was through unclassical redox mechanism.
文摘Thermodynamic properties and electrochemical behaviors of gold and its associated elements, such as silver, copper, nickel and iron, in various complex agent solutions were studied. Within CS（NH2）2, S2O2-3 and SCN- systems, alkaline thiourea is the optimal nontoxic lixiviating agent substituting cyanide from the viewpoint of thermodynamics. The electrochemical study indicates that the anodic dissolution current densities of gold are 2.616, （1.805,） 1.267, 1.088, 0.556, and 0.145 mA·cm-2 respectively in the solutions of cyanide, alkaline thiourea containing Na2SiO3, SCN-, acidic thiourea, alkaline thiourea and thiosulfate at the potential of 0.500 V. Comparing various lixiviating agents, the alkaline thiourea solution containing Na2SiO3 is of prominent selectivity in leaching gold, in the potential range from 0.500 to 0.600 V, which is most efficient for leaching gold selectively instead of cyanide. The effect on leaching gold is similar to that in the cyanide system.
基金supported by the National Natural Science Foundation of China(No.20805041)Training Programme Foundation for Excellent Youth Researching Talents of Fujian's Universities(No.JA10201)+1 种基金Key Provincial University Project of Fujian(No.2008F5064)Research Foundation of Fujian Education Department (No.JA09170)
文摘A cobalt（11） complex containing mixed-ligands of 1,10-phenathroline（phen） and glycollic acid（GA）.｜Co（GA）_2（phen）｜ was synthesized and its structure was characterized by X-ray diffraction.The interaction of the complex with DNA was investigated by electronic absorption spectra and electrochemical methods.Electronic absorption spectrum experiments showed that after interaction with DNA.the characteristic absorption peaks of ｜Co（GA）_2（phen）｜ underwent hypochromic effect as well as redshift. Also,the binding strength of 3.8×10~4L/mol was estimated by titration method.Electrochemical assays revealed that the redox peak currents of the complex decreased obviously accompanied by a positive shift of the formal potential after association with DNA.All these results revealed that the synthesized cobalt complex bound with DNA via an intercalation mode.
基金the National Key Research and Development Program of China(2017YFC0504601)the National Natural Science Foundation of China(41671513).
文摘The distribution of binding agents(i.e.,soil organic carbon(SOC)and glomalin-related soil protein(GRSP))in soil aggregates was influenced by many factors,such as plant characteristics and soil properties.However,how these factors affect binding agents and soil aggregate stability along a climatic gradient remained unclear.We selected the Robinia pseudoacacia L.forests from semi-arid to semi-humid of the Loess Plateau,China to analyze the plant biomass,soil physical-chemical properties,SOC and GRSP distribution in different sized soil aggregates.We found that from semi-arid to semi-humid forests:(1)the proportion of macro-aggregates(>0.250 mm)significantly increased(P<0.05),whereas those of micro-aggregates(0.250–0.053 mm)and fine materials(<0.053 mm)decreased and soil aggregate stability was increased;(2)the contents of SOC and GRSP in macro-aggregates and micro-aggregates significantly increased,and those in fine materials decreased;(3)the contribution of SOC to soil aggregate stability was greater than those of total GRSP and easily extractable GRSP;(4)soil properties had greater influence on binding agents than plant biomass;and(5)soil aggregate stability was enhanced by increasing the contents of SOC and GRSP in macro-aggregates and soil property was the important part during this process.Climate change from semi-arid to semi-humid forests is important factor for soil structure formation because of its positive effect on soil aggregates.
基金Project supported by Anguran Lead and Zinc Company(55/G/93)
文摘At present, the use of rare earth elements（REEs） has become an inevitable necessity in many modern industries. In general, liquid extraction is the best commercial method for extracting REEs due to its ability to control high volumes of liquids with electrical load. With the aim of improving a separation technology that would be superior to the existing extraction systems, the extraction behaviors of La（Ⅲ）,Pr（Ⅲ）, and Nd（Ⅲ） from an HCI medium with Cyanex 272 in the presence of the complexing agent lactic acid（HLac） and auxiliary agents citric acid（H3 Cit）, acetic acid（HAc）, and Titriplex Ⅲ have been reported.The effect of pH and lactic acid concentration has been examined. The use of lactic acid as a complexing agent leading to a high extraction of REEs with Cyanex 272 at pH = 5 was compared with systems without lactic acid. The results show that the use of acetic acid along with lactic acid leads to an increase in the extraction percentage of LREEs. While use of citric acid and Titriplex Ⅲ reduces the extraction percentage of LREEs. Finally, the presence of Titriplex Ⅲ together with lactic acid could lead to an increase in the separation factor of Pr and Nd.
基金This project was supported fi nancially by the Natural Science Foundation of Beijing Municipality(Grant number 6202021).
文摘Urban forest soil is often disturbed by rapid urbanization. Organic mulching is effective for improving soil quality and aggregate stability. This study evaluated how soil binding agents changed aggregate stability through organic mulching in urban forest soils. Three treatments were applied in Jiufeng National Forest Park, Beijing: (1) no organic mulch (control);(2) wood chips alone (5 cm thickness);and, (3) wood chips + wood compost (This mulch was divided into two layers, the upper layer of wood chips (2.5 cm), the lower layer wood compost (2.5 cm)). Soil samples were collected from the surface 10- cm soil layer and fraction into four aggregates. Glomalin-related soil protein and soil organic carbon were measured in bulk soil and the four aggregates. The results show that wood chips + wood compost increased the proportion of large and small macroaggregates, mean weight diameter and geometric mean diameter. The total and easily extractable glomalin-related soil protein were higher in the wood chips + wood compost. However, soil organic carbon was lower in the wood chips alone application compared to the controls and wood chips + wood compost. Easily extractable / total glomalin-related soil protein and glomalin-related soil protein / soil organic carbon ratios of wood chips alone and wood chips + wood compost had increased trend compared to the controls but did not reach significant levels (p > 0.05). Mean weight diameter and geometric mean diameter correlated positively with total and easily extractable glomalin-related soil protein but were not positively correlated with soil organic carbon, the ratios of easily extractable and total glomalin-related soil protein, and the ratios of glomalin-related soil protein and soil organic carbon. Redundancy analysis revealed that total glomalin-related soil protein was the most important driver for soil aggregate stability, especially the total glomalin-related soil protein of small macroaggregates. The results suggest that wood chips + wood compost enhanced soil aggregate stability through the increase of glomalin-related soil protein. Wood chips alone cannot enhance soil aggregate stability in urban forests in the short term.
文摘The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.
基金Project supported by National Natural Science Foundation of China (20962016)the Key Research Foundation of Education Ministry of China (208159)
文摘Two ligands 2,2＇-[2,3-naphthylenebis（oxy）]-bis（N-benzyl（acetamide））（L1） and 2,2＇-[2,3-naphthylenebis （oxy）]-bis（N,N-diphenyl （acetamide））（L2） and their europium（Ill） picrate complexes were synthesized. The complexes were characterized by elemental analysis, inf,- red （IR）, thermogravimetry and differential thermal analysis （TG-DTA） and molar conductivity. Fluorescent experiments showed that the resonance level of the Eu（III） matched better to the triplet state energy level of the ligand L2 than that of the ligand L1 and the fluorescence in- tensities of the complexes were reduced with the raising coordination ability of solvent. In addition, the interactions between the complexes and DNA were studied by means of spectrometry and cyclic voltammetry. The results suggested that the complexes could bind to DNA through intercalation and the complex 1 binded to DNA more strongly than the complex 2.
文摘Tabular PE PbTiO 3, spherical PY PbTiO 3, and acicular PX PbTiO 3 powders were hydrothermally synthesized from triethanolamine(TEA) complexed precursor; clubbed PE PbTiO 3 powders were obtained from diethanolamine(DEA) complexed precursor. The effects of pH of the hydrolyzation as well as complexing agents including TEA, DEA, and MEA(monoethanolamine) on the structure and the morphology of PbTiO 3 powders are discussed. The optimal conditions for hydrothermal syntheses of acicular and clubbed PbTiO 3 powders have been established. The products were characterized by means of XRD, TEM and other techniques.
基金Project supported by National Natural Science Foundation of China (51173140)Key Natural Science Foundation of Hubei Province (2009CDA052)Wuhan Scientific and Technological Research and Development Program, Hubei Province (201060623274)
文摘Gadolinium diethylenetriamine-pentaacetic bisdopamide （Gd-DTPA-2DA） was synthesized by the incorporation of dopamine to diethylenetriaminepentaacetic acid （DTPA） and further reaction with gadolinium chloride. In vitro and in vivo properties were also evaluated. Gadolinium complex Gd-DTPA-2DA possessed higher relaxation effectiveness and less cytotoxicity to HeLa cells than that of Gd-DTPA. Moreover, Gd-DTPA-2DA greatly enhanced the contrast of MR images of the brains, provided prolonged intravascular duration, and pro- duced highly contrasted visualization of the brain.
基金partly supported by the National Natural Science Foundation of China (No.51404263)the National Natural Science Foundation of Jiangsu Province (No.BK20130203)+3 种基金the Coal Mine Joint Funds of the National Natural Science Foundation of China (No.51134023)the State Key Laboratory Cultivation Base for Gas Geology and Gas Control (No.WS2013A05)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the independent study for State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology (No.SKLCRSM09X04)
文摘After gas drainage, the outburst seam is dry and, consequently, during subsequent mechanized mining, unwanted dust production is extensive. Because the hard dustfall typically has a small particle size it contains a high percentage of respirable dust. Considering these factors, this paper improved the efficiency of dustfall by reducing the surface tension of the liquid used as a wetting agent, then configuring five kinds of wetting agents by adopting various doses and types of surfactants, neutral inorganic salts and chemical additives, etc. After purchasing DA-85 and SRJ-1 wetting agent, the surface tension and critical micelle concentration of seven kinds of wetting agents were measured using the capillary rise method. Wetting agent A was confirmed to have the best comprehensive effect. The experiments were optimized by measuring and comparatively analyzing contact angles of pure water, SRJ-1 wetting agent and wetting agent A on the surface of different coal samples using a contact angle measurement instrument （HARKE- SPCA）. By comparative analysis, dust-proof effects of seam, dynamic pressure water infusion and high- pressure spray in the tunneling face at the Daning coal mine using pure water, wetting agent SRJ-1 and A, it was determined that after using wetting agent A, the average dust concentration in the place of the mining machine driver, 10 m and 110 m away from the tunneling front is approximately 300 rag/ m^3, 240 mg/m^3 and 100 mg/m^3, respectively, This practice increased the dust-proof efficiency dramati- cally and achieved a good comprehensive dust-proof effect.
基金the National Natural Science Foundation of China(Nos.21572091 and 21772078)the Fundamental Research Funds for the Central Universities(Nos.2682019CX70 and 2682019CX71)。
文摘Three fluorescent BINOL-Si complexes(FS1,FS2 and FS3)were rationally designed and synthesized to detect diethyl chlorophosphate(DCP),a mimic of lethal nerve agents.These three fluorescent probes showed green,yellow and orange fluorescence,respectively.Moreover,the series of fluorescent probes has the characteristics of fast response time(4 s),low detection limit(0.0097 mmol/L),high sensitivity and naked eye detection.More important,a fiber optic sensor capable of detecting DCP vapor in real time was also prepared for the first time,the lowest detection limits(down to 4.4 ppb)were all lower than that of the IDLH(immediately dangerous to life or health)concentration of Sarin(7.0 ppb).
基金Project(21001118)supported by National Natural Science Foundation of ChinaProject(12JJ3016)supported by Natural Science Foundation of Hunan Province,China
文摘A copper-bispyridylpyrrolide complex [Cu(PDPH)Cl](PDPH = 2,5-bis(2′-pyridyl)pyrrole) was synthesized and characterized. The complex crystallizes in the orthorhombic system with space group Pccn, a = 0.9016(3) nm, b = 1.0931(4) nm, c =2.5319(8) nm, and V = 2.4951(15) nm3. The copper center is situated in a square planar geometry. The interaction of the copper(II)complex with calf thymus DNA(CT-DNA) was investigated by electronic absorption, circular dichroism(CD) and fluorescence spectra. It is proposed that the complex binds to CT-DNA through groove binding mode. Nuclease activity of the complex was also studied by gel electrophoresis method. The complex can efficiently cleave supercoiled p BR322 DNA in the presence of ascorbate(H2A) via oxidative pathway. The preliminary mechanism of DNA cleavage by the complex with different inhibiting reagents indicates that the hydroxyl radicals were involved as the active species in the DNA cleavage process.
文摘A new cobalt(Ⅱ) complex with tridentate ligand 2, 6-bis (benzimidazol- 2-yl)pyridine has been synthesized by microwave irradiation method and characterized by elemental analysis, electrochemical and spectral methods. The binding of the complex with calf thymus DNA has also been investigated by absorption and fluorescence spectra.
基金supported by the National Natural Science Foundation of China(No.21173197)
文摘Two silver（I）-sulfonate complexes,[Ag（NO3）（4,4＇-bipy）][Ag（HL）（4,4＇-bipy）]·2H2O（1） and[Ag（H2O）（4,4＇-bipy）][AgL（4,4＇-bipy）]·2H2O（2）,have been synthesized by in situ reaction（H2L = 2-formylbenzenesulfonic acid,4,4-bipy = 4,4-bipyridine）.1 displays two parallel 1D chains expending to a 3D supramolecule by n—n interactions and O-H…O hydrogen bonds,in which the[Ag（NO3）]or[Ag（HL）]units are joined by bridging 4,4＇-bipy molecules,respectively.The interactions between the complexes and DNA were studied by means of fluorescence spectra and surface-enhanced Raman scattering（SERS） spectra.The special configuration and intercalation effects between 1 and DNA are stronger than that between 2 and DNA.
基金supported by the Natural Science Project of Zhejiang Province(LY12B01003)
文摘A complex [Cd2Na2（BOABA）2（H2O）8]·H2O（1） was synthesized by using 2,4-bisoxyacetate-benzoic acid（H3BOABA） and Cd（OH）2. It was characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complex 1 shows a two-dimensional 3-connected rigid plane. The interactions between the ligand and its complex with DNA were studied by Et Br fluorescence probe. Photoluminescent studies indicate that the complex may be excellent candidates for potential photoactive materials.
基金Project supported by State Key Laboratory of Rare Earth Resource Utilization,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences
文摘The adsorption of rare earths,lanthanum,cerium,neodymium,and yttri um by di(2-ethylhexyl) phosphoric acid(D2EHPA) resin in the presence of a compl exing agent,EDTA,was investigated. Flow injection was selected as the injectin g method. Various parameters,sample pH,sample loading time,sample flow rate,EDTA concentration,EDTA flow rate,eluent concentration,and eluent flow rate,were studied and optimized. Under the optimum conditions,the method allowed the determination of rare earths with detection limits of 1.09 μg/L(lanthanum),3 .31 μg/L(cerium),2.05 μg/L(neodymium),and 1.25 μg/L(yttrium) . High repea tabilities were obtained for all the four rare earths(RSD【5%) . The proposed met hod was applied to the determination of the rare earths in water samples with a recovery range of 95.8%-103.3%.
