Preparation of electronic grade manganese sulfate from ferromanganese slag, including grinding, leaching and purification, was studied. The impurities, such as Fe3+, Al3+, Ca2+, Mg2+, heavy metal ions and Na+, K+, wer...Preparation of electronic grade manganese sulfate from ferromanganese slag, including grinding, leaching and purification, was studied. The impurities, such as Fe3+, Al3+, Ca2+, Mg2+, heavy metal ions and Na+, K+, were removed from leaching solution by neutralized-hydrolysis, fluorination precipitation, sulfuration precipitation and re-crystallization. Effects of pH of reaction, temperature and dosage of the different additives on removal rates of the metallic ions in leaching solution were investigated, and the suitable temperature, pH and the added amount of precipitating agent were obtained. The prepared manganese sulfate product, of which the mass fractions of Ca2+, Mg2+, Na+, K+ are all smaller than 0.005%, the mass fractions of Fe3+, Al3+ and heavy metal ions are smaller than 0.001%, and the mass fraction of Mn2+ is greater than 32%, can meet the demand of anode materials of lithium-ion batteries.展开更多
A mutant UW 3, which is unable to fix N 2 in the presence of Mo (Nif -) but undergo phenotypic reversal to Nif + under Mo deficiency, was able to grow in Mo- and NH 3-deficient medium containing Mn, and the growt...A mutant UW 3, which is unable to fix N 2 in the presence of Mo (Nif -) but undergo phenotypic reversal to Nif + under Mo deficiency, was able to grow in Mo- and NH 3-deficient medium containing Mn, and the growth was accelerated by Mn at low concentration. A partly purified nitrogenase component Ⅰ protein separated from UW 3 grown in the Mn-containing medium was shown to contain Fe and Mn atoms (ratio of Fe/Mo/Mn: 10.41/0.19/1.00) with C 2H 2- and H +-reducing activity which almost equal to half of that of MoFe protein purified from wild-type mutant of Azotobacter vinelandii Lipmann. This protein was obviously different from MoFe protein in both absorption spectrum and circular dichroism, and the molecular weight of subunits in Mn-containing protein was close to that of α subunit in MoFe protein. The preliminary results indicated that the protein containing Mn might be a nitrogenase component Ⅰ protein.展开更多
An experiment was conducted to examine the role of Mn in P fixation through comparing with Al and Fe. Hydroxides and oxides of Al, Fe and Mn were prepared in lab under opened and closed conditions to react with phosph...An experiment was conducted to examine the role of Mn in P fixation through comparing with Al and Fe. Hydroxides and oxides of Al, Fe and Mn were prepared in lab under opened and closed conditions to react with phosphate. The newly formed Mn hydroxide showed the strongest P-fixing abilityl even several times higher than Fe hydroxide, but became the lowest rapidly due to ageing when exposed to air. Mn oxide showed the lowest p-fixing ability. Therefore, a sound consideration on P fixation should be based on both quantities and p-fixing abilities of the compounds of Fe, Al and Mn. The importance of Mn on P availability should receive more attention especially under oxidation-reduction dynamic conditions.展开更多
Sol sol gel method and solid phase redox reaction were respectively applied in preparation of Nanosize MnO 2 powders. The experiments showed that only Mn 2O 3 could be obtained from ignition of Mn(Ⅱ) in the muffle fu...Sol sol gel method and solid phase redox reaction were respectively applied in preparation of Nanosize MnO 2 powders. The experiments showed that only Mn 2O 3 could be obtained from ignition of Mn(Ⅱ) in the muffle furnace in air, and Mn 2O 3 had to be disproportionated in acids to gain MnO 2. The analysis of XRD and TEM technique revealed that the diameters of nanosize MnO 2 obtained by sol gel method was 35～45 nm and the x in MnO x was 1 9; the particle size of MnO 2 produced from solid phase redox reaction was 10～20 nm and the x in MnO x equaled 1 94. The test results have proved that the discharge property of alkaline manganese battery could be improved by nanosize MnO 2.展开更多
Bioconversion of lignocellulosic wastes to higher value products through fungal fermentation has economic and ecological benefits. In this study, to develop an effective strategy for production of manganese peroxidase...Bioconversion of lignocellulosic wastes to higher value products through fungal fermentation has economic and ecological benefits. In this study, to develop an effective strategy for production of manganese peroxidase(Mn P)from cassava residue by Phanerochaete chrysosporium in solid state fermentation, the stimulators of Mn P production were screened and their concentrations were optimized by one-at-a-time experiment and Box–Behnken design. The maximum Mn P activity of 186.38 nkat·g-1dry mass of the sample was achieved after 6 days of fermentation with the supplement of 79.5 mmol·L-1·kg-1acetic acid, 3.21 ml·kg-1soybean oil, and 28.5 g·kg-1alkaline lignin, indicating that cassava residue is a promising substrate for Mn P production in solid state fermentation. Meanwhile, in vitro decolorization of indigo carmine by the crude Mn P was also carried out, attaining the ratio of 90.18% after 6 h of incubation. An oxidative mechanism of indigo carmine decolorization by Mn P was proposed based on the analysis of intermediate metabolites with ultra-high performance liquid chromatography and gas chromatography tandem mass spectrometry. Using the crude Mn P produced from cassava residue for indigo carmine decolorization gives an effective approach to treat dyeing effluents.展开更多
Flexible and micro-sized energy conversion/storage components are extremely demanding in portable and multifunctional electronic devices, especially those small,flexible, roll-up and even wearable ones. Here in this p...Flexible and micro-sized energy conversion/storage components are extremely demanding in portable and multifunctional electronic devices, especially those small,flexible, roll-up and even wearable ones. Here in this paper, a two-step electrochemical deposition method has been developed to coat Ni fibers with reduced graphene oxide and MnO2 subsequently, giving rise to Ni@reduced-graphene-oxide@MnO2 sheath-core flexible electrode with a high areal specific capacitance of 119.4 mF cm^-2 at a current density of 0.5 mA cm^-2 in 1 mol L^-1 Na2SO4 electrolyte. Using polyvinyl alcohol（PVA）-LiCl as a solid state electrolyte, two Ni@reduced-grapheneoxide@Mn02 flexible electrodes were assembled into a freestanding, lightweight, symmetrical fiber-shaped micro-supercapacitor device with a maximum areal capacitance of26.9 mF cm^-2. A high power density of 0.1 W cm^-3 could be obtained when the energy density was as high as0.27 mW h cm^-3. Moreover, the resulting micro-supercapacitor device also demonstrated good flexibility and high cyclic stability. The present work provides a simple, facile and low-cost method for the fabrication of flexible, lightweight and wearable energy conversion/storage micro-devices with a high-performance.展开更多
基金Project(2013ZX0754-001)supported by China National Critical Project for Science and Technology on Water Pollution Prevention and Control
文摘Preparation of electronic grade manganese sulfate from ferromanganese slag, including grinding, leaching and purification, was studied. The impurities, such as Fe3+, Al3+, Ca2+, Mg2+, heavy metal ions and Na+, K+, were removed from leaching solution by neutralized-hydrolysis, fluorination precipitation, sulfuration precipitation and re-crystallization. Effects of pH of reaction, temperature and dosage of the different additives on removal rates of the metallic ions in leaching solution were investigated, and the suitable temperature, pH and the added amount of precipitating agent were obtained. The prepared manganese sulfate product, of which the mass fractions of Ca2+, Mg2+, Na+, K+ are all smaller than 0.005%, the mass fractions of Fe3+, Al3+ and heavy metal ions are smaller than 0.001%, and the mass fraction of Mn2+ is greater than 32%, can meet the demand of anode materials of lithium-ion batteries.
文摘A mutant UW 3, which is unable to fix N 2 in the presence of Mo (Nif -) but undergo phenotypic reversal to Nif + under Mo deficiency, was able to grow in Mo- and NH 3-deficient medium containing Mn, and the growth was accelerated by Mn at low concentration. A partly purified nitrogenase component Ⅰ protein separated from UW 3 grown in the Mn-containing medium was shown to contain Fe and Mn atoms (ratio of Fe/Mo/Mn: 10.41/0.19/1.00) with C 2H 2- and H +-reducing activity which almost equal to half of that of MoFe protein purified from wild-type mutant of Azotobacter vinelandii Lipmann. This protein was obviously different from MoFe protein in both absorption spectrum and circular dichroism, and the molecular weight of subunits in Mn-containing protein was close to that of α subunit in MoFe protein. The preliminary results indicated that the protein containing Mn might be a nitrogenase component Ⅰ protein.
文摘An experiment was conducted to examine the role of Mn in P fixation through comparing with Al and Fe. Hydroxides and oxides of Al, Fe and Mn were prepared in lab under opened and closed conditions to react with phosphate. The newly formed Mn hydroxide showed the strongest P-fixing abilityl even several times higher than Fe hydroxide, but became the lowest rapidly due to ageing when exposed to air. Mn oxide showed the lowest p-fixing ability. Therefore, a sound consideration on P fixation should be based on both quantities and p-fixing abilities of the compounds of Fe, Al and Mn. The importance of Mn on P availability should receive more attention especially under oxidation-reduction dynamic conditions.
文摘Sol sol gel method and solid phase redox reaction were respectively applied in preparation of Nanosize MnO 2 powders. The experiments showed that only Mn 2O 3 could be obtained from ignition of Mn(Ⅱ) in the muffle furnace in air, and Mn 2O 3 had to be disproportionated in acids to gain MnO 2. The analysis of XRD and TEM technique revealed that the diameters of nanosize MnO 2 obtained by sol gel method was 35～45 nm and the x in MnO x was 1 9; the particle size of MnO 2 produced from solid phase redox reaction was 10～20 nm and the x in MnO x equaled 1 94. The test results have proved that the discharge property of alkaline manganese battery could be improved by nanosize MnO 2.
基金Supported by the Science&Technology Program of Jiangsu Province(BE2011623)the Scientific Research Project of Provincial Environmental Protection Bureau of Jiangsu Province(2012047)
文摘Bioconversion of lignocellulosic wastes to higher value products through fungal fermentation has economic and ecological benefits. In this study, to develop an effective strategy for production of manganese peroxidase(Mn P)from cassava residue by Phanerochaete chrysosporium in solid state fermentation, the stimulators of Mn P production were screened and their concentrations were optimized by one-at-a-time experiment and Box–Behnken design. The maximum Mn P activity of 186.38 nkat·g-1dry mass of the sample was achieved after 6 days of fermentation with the supplement of 79.5 mmol·L-1·kg-1acetic acid, 3.21 ml·kg-1soybean oil, and 28.5 g·kg-1alkaline lignin, indicating that cassava residue is a promising substrate for Mn P production in solid state fermentation. Meanwhile, in vitro decolorization of indigo carmine by the crude Mn P was also carried out, attaining the ratio of 90.18% after 6 h of incubation. An oxidative mechanism of indigo carmine decolorization by Mn P was proposed based on the analysis of intermediate metabolites with ultra-high performance liquid chromatography and gas chromatography tandem mass spectrometry. Using the crude Mn P produced from cassava residue for indigo carmine decolorization gives an effective approach to treat dyeing effluents.
基金supported by the Ministry of Education of China (IRT1148)the National Natural Science Foundation of China (51772157 and 21173116)+3 种基金Synergistic Innovation Center for Organic Electronics and Information Displays,Jiangsu Province "Six Talent Peak" (2015-JY-015)Jiangsu Provincial Natural Science Foundation (BK20141424)the Program of Nanjing University of Posts and Telecommunications (NY214088)the Open Research Fund of State Key Laboratory of Bioelectronics of Southeast University (12015010)
文摘Flexible and micro-sized energy conversion/storage components are extremely demanding in portable and multifunctional electronic devices, especially those small,flexible, roll-up and even wearable ones. Here in this paper, a two-step electrochemical deposition method has been developed to coat Ni fibers with reduced graphene oxide and MnO2 subsequently, giving rise to Ni@reduced-graphene-oxide@MnO2 sheath-core flexible electrode with a high areal specific capacitance of 119.4 mF cm^-2 at a current density of 0.5 mA cm^-2 in 1 mol L^-1 Na2SO4 electrolyte. Using polyvinyl alcohol（PVA）-LiCl as a solid state electrolyte, two Ni@reduced-grapheneoxide@Mn02 flexible electrodes were assembled into a freestanding, lightweight, symmetrical fiber-shaped micro-supercapacitor device with a maximum areal capacitance of26.9 mF cm^-2. A high power density of 0.1 W cm^-3 could be obtained when the energy density was as high as0.27 mW h cm^-3. Moreover, the resulting micro-supercapacitor device also demonstrated good flexibility and high cyclic stability. The present work provides a simple, facile and low-cost method for the fabrication of flexible, lightweight and wearable energy conversion/storage micro-devices with a high-performance.
