A new process for utilization of hazardous lead-bearing wastes and iron-rich wastes by reducing-matting smelting has been developed.The slag(SG) and the iron-rich matte(IRM) are the main by-products from reducing-...A new process for utilization of hazardous lead-bearing wastes and iron-rich wastes by reducing-matting smelting has been developed.The slag(SG) and the iron-rich matte(IRM) are the main by-products from reducing-matting smelting of lead-bearing wastes and iron-rich wastes.The environmental risk of heavy metals(Cd,Zn,Pb and As) in the main by-products versus the charging material for reducing-matting smelting(CM) has been systematically assessed using leaching toxicity test,the three-stage sequential extraction procedure of European Community Bureau of Reference(BCR) and Hakanson Potential Ecological Risk Index Method(PERI).The results demonstrate that the ecological risk level of heavy metals for SG and IRM is significantly reduced after the reducing-matting smelting process compared with that for CM.展开更多
The effects of moderately thermophilic bacteria on the extraction of metals from zinc smelting slag and electrochemical characteristics of zinc smelting slag carbon paste electrode in bioleaching process were studied....The effects of moderately thermophilic bacteria on the extraction of metals from zinc smelting slag and electrochemical characteristics of zinc smelting slag carbon paste electrode in bioleaching process were studied. The results show that the extraction rates of Fe, Cu and Zn from the slag reach 86.7%, 90.3% and 66.7% after adsorbed bacteria sterilize, while those with adsorbed bacteria are 91.9%, 96.0% and 84.5% in conditions of pulp density 2%, pH 1.0, temperature 65 °C and stirring rate 120 r/min, respectively. Some stretching peaks of functional groups from bacterial secretes on the bioleached residue surface, such as 1007 cm-1 and 1193 cm-1, turn up through FI-IR analysis and indirectly reveal the presence of the adsorbed bacteria on the slag particles surface. Besides, the corrosion of zinc smelting slag is enhanced by bacteria according to the characteristics of cyclic voltametry and Tafel curves in bioleaching system.展开更多
The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,ind...The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.展开更多
In order to reasonably utilize the abundant resources of high-phosphorus iron ore and ilmenite in China, the technology of top-blown smelting reduction with oxygen enrichment was used to smelt the mixed ore of high-ph...In order to reasonably utilize the abundant resources of high-phosphorus iron ore and ilmenite in China, the technology of top-blown smelting reduction with oxygen enrichment was used to smelt the mixed ore of high-phosphorus iron and ilmenite. The effect, which is related to basicity, reduction temperature, carbon-oxygen ratio and time of ventilated oxygen to iron recovery, dephosphorization rate, content of iron, phosphorus, sulfur and titanium in pig iron, was investigated in the experiment. The results show that an ideal outcome can be gained in condition of 6:4 ration on Mengqiao concentrate and Huimin iron ore, temperature of 1 500℃, basicity of 1.3, 1.0 on molar ration of carbon to oxygen, time of 10 min on blowing-oxygen. The outcome is that there is no foamy slag in generation, a good separation of slag and iron, iron recovery with 91.41%, content of phosphorus with 0.27% and tilanium content less than 0.001%, The atmosphere of strong oxidizing in the upper of reduction container and high potential of oxygen in the composition of slag in this technique bring phosphorus, titanium and silicon into slag, which ensures less content of impurity in pig iron.展开更多
Exchange bias effect is observed in the phase separated La0.33Pr0.34Ca0.33MnO3 thin films. High exchange bias field of about 1 kOe is achieved at 4 K. The exchange bias effect in La0.33Pr0.34Ca0.33MnO3 thin films migh...Exchange bias effect is observed in the phase separated La0.33Pr0.34Ca0.33MnO3 thin films. High exchange bias field of about 1 kOe is achieved at 4 K. The exchange bias effect in La0.33Pr0.34Ca0.33MnO3 thin films might originate from the intrinsic phase separation of the La0.33Pr0.34Ca0.33MnO3 or surface effect. The dependence of exchange bias effect on temperature, cooling field, and thickness is also investigated. This work would open an avenue to the application in the magnetic memory devices based on the phase separated manganites.展开更多
The composition and size distribution of cutting waste were characterized. The Si-rich powders were obtained from the cutting waste using a physical sedimentation process, and then further purified by removing impurit...The composition and size distribution of cutting waste were characterized. The Si-rich powders were obtained from the cutting waste using a physical sedimentation process, and then further purified by removing impurity using acid leaching. The effects of process parameters such as acid leaching time, temperature and the ratio of solid to liquid on the purification efficiency were investigated, and the parameters were optimized. Afterwards, the high-purity Si ingot was obtained by melting the Si-rich powders in vacuum furnace. Finally, the high purity Si with 99.96%Si, 1.1×10^-6 boron (B), and 4.0×10^-6 phosphorus (P) were obtained. The results indicate that it is feasible to extract high-purity Si, and further produce SoG-Si from the cutting slurry waste.展开更多
Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years ...Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Cuizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn (508 mg kg^-1), Pb (95.6 mg kg^-1), and Cd (5.98 mg kg^-1) with low ratios of Zn/Cd (59.1-115) and Pb/Cd (12.4-23.4). Composite pollution indices (CPIs) of surface soils (2.52-15.2) were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals (SDM) in soils within 1.5 km of the smelter (averaging 1.25) was six times higher than that of the reference soils (0.209). A smaller soil microbial biomass was found more frequently in metal accumulated soils (85.1-438 μg C g^-1) than in reference soils (497 μg C g^-1), and a negative correlation (P 〈 0.01) of soil microbial biomass carbon to organic carbon ratio (Cmic/Corg) with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM (R = -0.773, P 〈 0.01). Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and were detrimental to soil quality mainly in respect of microbial biomass .展开更多
The heat recovery steam generator(HRSG)of copper smelting generates a large number of arsenic−coppercontaining particles,and the in-situ separation of arsenic and copper is of importance for cutting off environmental ...The heat recovery steam generator(HRSG)of copper smelting generates a large number of arsenic−coppercontaining particles,and the in-situ separation of arsenic and copper is of importance for cutting off environmental risk and realizing resource recovery.The formation of arsenic−copper-containing particles was simulated,the method of in-situ decomposition of arsenic−copper-containing particles by pyrite was proposed,and the decomposition mechanism was confirmed.It was found that particles with high arsenic content were formed in the simulated HRSG,and copper arsenate was liable for the high arsenic content.Pyrite promoted the sulfation of copper,leading to the in-situ decomposition of copper arsenate.In this process,gaseous arsenic was released,and thus the separation of arsenic and copper was realized.展开更多
The influence of different concentrations of copper solvent extractant ZJ 988 on the growth and activity of acidophilic microorganisms was studied and the microbial community structures were compared by 16S rRNA gene ...The influence of different concentrations of copper solvent extractant ZJ 988 on the growth and activity of acidophilic microorganisms was studied and the microbial community structures were compared by 16S rRNA gene clone library analysis.The total bacteria numbers are reduced when 0.5%(volume fraction) extractant is added.The proportions of Acidithiobacillus ferrooxidans and Acidiphilium organovorum are increased,whereas the proportion of Leptospirillum ferriphilum is reduced.When the concentration of extractant is elevated to 1%,growth of all bacteria is inhibited.Clone library results reveal that the dominant bacteria in the culture solution with/without the extractant are At.ferrooxidans,A.organovorum and L.ferriphilum.The sensitivity order of the three bacteria to the extractant from the most to the least is found to be L.ferriphilum>At.ferrooxidans>A.organovorum.展开更多
The concentrates with different maceral contents were obtained from Kailuan coking coals with different coal ranks(Ro;ranvarying from 0.88%to 1.73%)by float–sink separation in lab.Then these concentrates were charact...The concentrates with different maceral contents were obtained from Kailuan coking coals with different coal ranks(Ro;ranvarying from 0.88%to 1.73%)by float–sink separation in lab.Then these concentrates were characterized by proximate analysis,ultimate analysis,petrography analysis and coking index determination.The results show that the vitrinite is characterized as nature of lower carbon content,higher hydrogen content,higher volatile matter and stronger caking property compared to inertinite.The relationships between variation rate of volatile matter and maximum volatile matter and coal ranks are identified,and a linear model is developed for fast determination of the maceral contents.Compared to inertinite-rich concentrate,the blending ratio of vitrinite-rich concentrate is increased by 13%,which is considered to be a potential technique based on maceral separation for expanding the coking coal resources.展开更多
Vibration training is more and more extensively applied to the field of strength training. It, as a beneficial supplement to the traditional strength, is able to improve specific strength or the strength of weak posit...Vibration training is more and more extensively applied to the field of strength training. It, as a beneficial supplement to the traditional strength, is able to improve specific strength or the strength of weak positions, for the purpose of achieving the muscle strength development in an all-round way. In this paper, the anatomy, physiology, and biomechanics foundations for vibration training to increase muscle strength are mainly analyzed, and then the principle of vibration training to increase muscle strength is further expounded, and also the increase of muscle strength is discussed from the aspects such as vibration frequency, vibration amplitude, vibration posture, vibration intermittent time, and vibration mode, so as to clarify the domestic and foreign progress of the study on vibration training.展开更多
Switch grass was developed as a pioneer energy crop in USA with great industrial prospect. It contains about 60% sugars and 18% lignin. The purpose of this research is to find pretreatment process to fractionate cellu...Switch grass was developed as a pioneer energy crop in USA with great industrial prospect. It contains about 60% sugars and 18% lignin. The purpose of this research is to find pretreatment process to fractionate cellulose, hemicellulose and lignin from switch grass to obtain much more useful chemicals and enhance the residue solid to be hydrolyzed by enzymes. The six different pretreatment methods were studied, such as hot water pretreatment (HWP) alone, dilute acid pretreatment (DAP), ammonia pretreatment (AP), lime pretreatment (LP), organosolv water / ehanol pretreatment (OWEP), and organosolv water / acetone pretreatment (OWAP). It was the best method combining DAP with OWEP because the hemicellulose sugars were recovered in the first residual liquid while a varied amount of cellulose was retained in the residual solid and the lignin fraction was obtained by simply adjusting the pH from the second liquid. The result shows the optimal two-stage process consisted of the first stage DAP at 428 K for 7 min with 0.8% sulfuric acid, resulting in 79.82% glucose recovery yield and 98.74% xylose removal and the second stage OWEP at 468K for 20 min in 45% (v / v) ethanol with 0.4% NaOH, resulting in 62% total glucose yield 99% xylose and 80% lignin removal. After enzymatic hydrolysis, the glucose yield was up to 92.6%, compared with 16% yield from untreated switch grass. Scanning electron microscopy (SEM) highlighted the differences in switch grass structure from the various pretreatment methods during biomass fractionation.展开更多
Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) suppo...Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) supported gold catalysts coated with a thin N-doped porous carbon(NPC)layer were developed via a polydopamine-coating-carbonization strategy and utilized for pathway-specific conversion of HMF into 5-methylfurfural(5-MF)with the use of renewable formic acid(FA)as the deoxygenation reagent.The as-fabricated Au/TiO_(2)@NPC exhibited excellent catalytic performance with a high yield of 5-MF(>95%).The catalytic behavior of Au@NPC-based catalysts was shown to be correlated with the suitable combination of highly dispersed Au nanoparticles and favorable interfacial interactions in the Au@NPC core-shell hetero-nanoarchitectures,thereby facilitating the preferential esterification of HMF with FA and suppressing unproductive FA dehydrogenation,which promoted the selective formylation/decarboxylation of hydroxy-methyl group in HMF in a pathway-specific manner.The present NPC/metal interfacial engineering strategy may provide a potential guide for the rational design of advanced catalysts for a wide variety of heterogeneous catalysis processes in terms of the conversion of biomass source.展开更多
Bio-fuel can be used to help transition from a petroleum-based society to a bio-based society. Ever since the China Development and Reform Commission suspended the approval of crop processing programs, second-generati...Bio-fuel can be used to help transition from a petroleum-based society to a bio-based society. Ever since the China Development and Reform Commission suspended the approval of crop processing programs, second-generation bio-ethanol research and industrialization processes have attracted significant attention. In 2020, bio-ethanol production is predicted to reach 10 million tons. Currently, there are a few domestic enterprises that have established different scaled pilot or demonstration bases for cellulosic ethanol, which reduce the cost of ethanol by continuously improving pretreatment and hydrolysis techniques. In the next three years, these enterprises will realize large-scale commercial production. Given the practical problems in cellulosic ethanol plant construction and operation(e.g., marketing price variation and difficulties in feedstock collection), this paper began with the concept of a "whole-crop refinery" and presented a solution to the integration of industry and agriculture as well as multi-crop refining. This paper then took the whole-crop refining system of corn as an example and presented an analysis of the logistics, energy flow, and economical efficiency of the system. The results demonstrated that the integrated system could properly reduce the required fixed investments in production equipment,shared utilities, and wastewater treatment facilities, as well as reduction of energy consumption. Although the proposed system has several problems, it brings the long-term goal of large-scale commercial application closer than ever.展开更多
Balance is an essential component of movement and is critical in the ability to participate in physical activity. Developing an exergaming curriculum for schools has the potential to improve balance or postural stabil...Balance is an essential component of movement and is critical in the ability to participate in physical activity. Developing an exergaming curriculum for schools has the potential to improve balance or postural stability in children. In this study, a purposely-built exergaming center in an elementary school was used to test fourth grade students with a specially designed exergaming curriculum oriented toward improving postural stability. The program was implemented over a 6-week period, 34 min per day, 4-5 days per week. Two control groups were used: (1) a physical education (PE) class geared toward agility, balance, and coordination (ABC) improvement, and (2) a typical PE curriculum class. Exergaming students improved their postural stability significantly over a 6-week period compared to those in the typical PE class. Improvements in postural stability were also evident in the ABC class. Postural stability in the girls was better than the boys in all pre- and post-intervention tests. This study demonstrates that exergaming is a practical resource in the PE class to improve postural stability.展开更多
A database-based strategy of candidate generation was proposed for molecular design of new de-phenol extractants following the idea of finding new applications of existing commercial compounds. The strategy has the ad...A database-based strategy of candidate generation was proposed for molecular design of new de-phenol extractants following the idea of finding new applications of existing commercial compounds. The strategy has the advantage that the environmental, safety and health risks of candidate compounds are known and controllable. In this work, the Existing Commercial Compounds(ECC) database and special combined search strategy were developed as the base for the proposed CAMD method following such idea, and molecules for phenol extraction used in coking wastewater treatment were selected from the ECC database. The candidate solvents cover the following categories: ketones, esters, ethers, alcohols, anhydrides and benzene compounds, which are consistent with the de-phenol extractants commonly used in the industry or experiment. The compounds with higher partition coefficient and selectivity than widely used methyl isobutyl ketone(MIBK) are mainly ketones. 26 obtained molecules show higher partition coefficient and selectivity than MIBK, which are suggested to be further investigated by experiment. Furthermore, analysis of these potential molecules may present the effective functional groups as the initial group set to generate new molecular structures of de-phenol extractants. The results show that the proposed method enables us to efficiently generate chemicals with benefits of less time, less economical cost, and known environmental impact as well.展开更多
基金Project(2012BAC12B02)supported by the National Key Technology R&D Program of ChinaProject(2014FJ1011)supported by the Key Projects of Science and Technology of Hunan Province,ChinaProject(2011AA061001)supported by the National High-tech Research and Development Program of China
文摘A new process for utilization of hazardous lead-bearing wastes and iron-rich wastes by reducing-matting smelting has been developed.The slag(SG) and the iron-rich matte(IRM) are the main by-products from reducing-matting smelting of lead-bearing wastes and iron-rich wastes.The environmental risk of heavy metals(Cd,Zn,Pb and As) in the main by-products versus the charging material for reducing-matting smelting(CM) has been systematically assessed using leaching toxicity test,the three-stage sequential extraction procedure of European Community Bureau of Reference(BCR) and Hakanson Potential Ecological Risk Index Method(PERI).The results demonstrate that the ecological risk level of heavy metals for SG and IRM is significantly reduced after the reducing-matting smelting process compared with that for CM.
基金Project (41271330) supported by the National Natural Science Foundation of China
文摘The effects of moderately thermophilic bacteria on the extraction of metals from zinc smelting slag and electrochemical characteristics of zinc smelting slag carbon paste electrode in bioleaching process were studied. The results show that the extraction rates of Fe, Cu and Zn from the slag reach 86.7%, 90.3% and 66.7% after adsorbed bacteria sterilize, while those with adsorbed bacteria are 91.9%, 96.0% and 84.5% in conditions of pulp density 2%, pH 1.0, temperature 65 °C and stirring rate 120 r/min, respectively. Some stretching peaks of functional groups from bacterial secretes on the bioleached residue surface, such as 1007 cm-1 and 1193 cm-1, turn up through FI-IR analysis and indirectly reveal the presence of the adsorbed bacteria on the slag particles surface. Besides, the corrosion of zinc smelting slag is enhanced by bacteria according to the characteristics of cyclic voltametry and Tafel curves in bioleaching system.
基金financial supports from the National Key R&D Program of China(No.2019YFC1907400)the National Natural Science Foundation of China(Nos.51904351,51620105013)。
文摘The metabolism of copper and arsenic in a copper pyrometallurgy process was studied through substance flow analysis method.The mass balance accounts and substance flow charts of copper and arsenic were established,indicators including direct recovery,waste recycle ratio,and resource efficiency were used to evaluate the metabolism efficiency of the system.The results showed that,the resource efficiency of copper was 97.58%,the direct recovery of copper in smelting,converting,and refining processes was 91.96%,97.13%and 99.47%,respectively.Meanwhile,for producing 1 t of copper,10 kg of arsenic was carried into the system,with the generation of 1.07 kg of arsenic in flotation tailing,8.50 kg of arsenic in arsenic waste residue,and 0.05 kg of arsenic in waste water.The distribution and transformation behaviors of arsenic in the smelting,converting,and refining processes were also analyzed,and some recommendations for improving copper resource efficiency and pollution control were proposed based on substance flow analysis.
基金Project(51064015) supported by the National Natural Science Foundation of ChinaProject(ZD2010001) supported by the Key Project of Yunnan Province Education of China
文摘In order to reasonably utilize the abundant resources of high-phosphorus iron ore and ilmenite in China, the technology of top-blown smelting reduction with oxygen enrichment was used to smelt the mixed ore of high-phosphorus iron and ilmenite. The effect, which is related to basicity, reduction temperature, carbon-oxygen ratio and time of ventilated oxygen to iron recovery, dephosphorization rate, content of iron, phosphorus, sulfur and titanium in pig iron, was investigated in the experiment. The results show that an ideal outcome can be gained in condition of 6:4 ration on Mengqiao concentrate and Huimin iron ore, temperature of 1 500℃, basicity of 1.3, 1.0 on molar ration of carbon to oxygen, time of 10 min on blowing-oxygen. The outcome is that there is no foamy slag in generation, a good separation of slag and iron, iron recovery with 91.41%, content of phosphorus with 0.27% and tilanium content less than 0.001%, The atmosphere of strong oxidizing in the upper of reduction container and high potential of oxygen in the composition of slag in this technique bring phosphorus, titanium and silicon into slag, which ensures less content of impurity in pig iron.
基金V. ACKNOWLEDGEMENTS This work was supported by the National Natural Science Foundation of China (No.11374279 and No.11034006), the National Basic Research Program of China (No.2014CB921102), the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB01020000), the Specialized Research Fund for the Doctoral Program of Higher Education (No.20113402110046), and the Fundamental Research Funds for the Central Universities (No.WK2340000035).
文摘Exchange bias effect is observed in the phase separated La0.33Pr0.34Ca0.33MnO3 thin films. High exchange bias field of about 1 kOe is achieved at 4 K. The exchange bias effect in La0.33Pr0.34Ca0.33MnO3 thin films might originate from the intrinsic phase separation of the La0.33Pr0.34Ca0.33MnO3 or surface effect. The dependence of exchange bias effect on temperature, cooling field, and thickness is also investigated. This work would open an avenue to the application in the magnetic memory devices based on the phase separated manganites.
基金Project (51074043) supported by the National Natural Science Foundation of ChinaProject (2011BAE03B01) supported by the National Technology Support Program of ChinaProject (N120409004) supported by the Fundamental Research Funds for Central Universities,China
文摘The composition and size distribution of cutting waste were characterized. The Si-rich powders were obtained from the cutting waste using a physical sedimentation process, and then further purified by removing impurity using acid leaching. The effects of process parameters such as acid leaching time, temperature and the ratio of solid to liquid on the purification efficiency were investigated, and the parameters were optimized. Afterwards, the high-purity Si ingot was obtained by melting the Si-rich powders in vacuum furnace. Finally, the high purity Si with 99.96%Si, 1.1×10^-6 boron (B), and 4.0×10^-6 phosphorus (P) were obtained. The results indicate that it is feasible to extract high-purity Si, and further produce SoG-Si from the cutting slurry waste.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KZCX2-105)the "Light in Western China" Program of the Chinese Academy of Sciences and Guizhou Province, and the National Natural Science Foundation of China (No.40473049)
文摘Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Cuizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn (508 mg kg^-1), Pb (95.6 mg kg^-1), and Cd (5.98 mg kg^-1) with low ratios of Zn/Cd (59.1-115) and Pb/Cd (12.4-23.4). Composite pollution indices (CPIs) of surface soils (2.52-15.2) were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals (SDM) in soils within 1.5 km of the smelter (averaging 1.25) was six times higher than that of the reference soils (0.209). A smaller soil microbial biomass was found more frequently in metal accumulated soils (85.1-438 μg C g^-1) than in reference soils (497 μg C g^-1), and a negative correlation (P 〈 0.01) of soil microbial biomass carbon to organic carbon ratio (Cmic/Corg) with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM (R = -0.773, P 〈 0.01). Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and were detrimental to soil quality mainly in respect of microbial biomass .
基金financially supported by the National Science Fund for Excellent Young Scholars of China(No.52022111)the National Key Research and Development Program of China(Nos.2017YFC0210401,2018YFC1900306)+1 种基金the Distinguished Young Scholars of China(No.51825403)the National Natural Science Foundation of China(Nos.51634010,51974379).
文摘The heat recovery steam generator(HRSG)of copper smelting generates a large number of arsenic−coppercontaining particles,and the in-situ separation of arsenic and copper is of importance for cutting off environmental risk and realizing resource recovery.The formation of arsenic−copper-containing particles was simulated,the method of in-situ decomposition of arsenic−copper-containing particles by pyrite was proposed,and the decomposition mechanism was confirmed.It was found that particles with high arsenic content were formed in the simulated HRSG,and copper arsenate was liable for the high arsenic content.Pyrite promoted the sulfation of copper,leading to the in-situ decomposition of copper arsenate.In this process,gaseous arsenic was released,and thus the separation of arsenic and copper was realized.
基金Project(50904011) supported by the National Natural Science Foundation of China
文摘The influence of different concentrations of copper solvent extractant ZJ 988 on the growth and activity of acidophilic microorganisms was studied and the microbial community structures were compared by 16S rRNA gene clone library analysis.The total bacteria numbers are reduced when 0.5%(volume fraction) extractant is added.The proportions of Acidithiobacillus ferrooxidans and Acidiphilium organovorum are increased,whereas the proportion of Leptospirillum ferriphilum is reduced.When the concentration of extractant is elevated to 1%,growth of all bacteria is inhibited.Clone library results reveal that the dominant bacteria in the culture solution with/without the extractant are At.ferrooxidans,A.organovorum and L.ferriphilum.The sensitivity order of the three bacteria to the extractant from the most to the least is found to be L.ferriphilum>At.ferrooxidans>A.organovorum.
基金financially supported by the Fundamental Research Funds for the Central Universities of China (No.2010YH11)
文摘The concentrates with different maceral contents were obtained from Kailuan coking coals with different coal ranks(Ro;ranvarying from 0.88%to 1.73%)by float–sink separation in lab.Then these concentrates were characterized by proximate analysis,ultimate analysis,petrography analysis and coking index determination.The results show that the vitrinite is characterized as nature of lower carbon content,higher hydrogen content,higher volatile matter and stronger caking property compared to inertinite.The relationships between variation rate of volatile matter and maximum volatile matter and coal ranks are identified,and a linear model is developed for fast determination of the maceral contents.Compared to inertinite-rich concentrate,the blending ratio of vitrinite-rich concentrate is increased by 13%,which is considered to be a potential technique based on maceral separation for expanding the coking coal resources.
文摘Vibration training is more and more extensively applied to the field of strength training. It, as a beneficial supplement to the traditional strength, is able to improve specific strength or the strength of weak positions, for the purpose of achieving the muscle strength development in an all-round way. In this paper, the anatomy, physiology, and biomechanics foundations for vibration training to increase muscle strength are mainly analyzed, and then the principle of vibration training to increase muscle strength is further expounded, and also the increase of muscle strength is discussed from the aspects such as vibration frequency, vibration amplitude, vibration posture, vibration intermittent time, and vibration mode, so as to clarify the domestic and foreign progress of the study on vibration training.
基金Acknowledgments This research was supported by Hubei Provincal Department of Education (No. CXY2009B2008), Angel Yeast Co.Ltd (SDH200800230), the Science Foundation of Yichang City (No. A2007103-1), the Alan G. MacDiarmid Institute of Renewable Energy, Yichang, China and the USDA Western Regional Research Center (WRRC). The authors thank WRRC Center Director James N. Seiber, Artur, Klamczynski and Charles Lee for the thoughtful discussions and technical insights, and Miss Tina William for the SEM imagines.
文摘Switch grass was developed as a pioneer energy crop in USA with great industrial prospect. It contains about 60% sugars and 18% lignin. The purpose of this research is to find pretreatment process to fractionate cellulose, hemicellulose and lignin from switch grass to obtain much more useful chemicals and enhance the residue solid to be hydrolyzed by enzymes. The six different pretreatment methods were studied, such as hot water pretreatment (HWP) alone, dilute acid pretreatment (DAP), ammonia pretreatment (AP), lime pretreatment (LP), organosolv water / ehanol pretreatment (OWEP), and organosolv water / acetone pretreatment (OWAP). It was the best method combining DAP with OWEP because the hemicellulose sugars were recovered in the first residual liquid while a varied amount of cellulose was retained in the residual solid and the lignin fraction was obtained by simply adjusting the pH from the second liquid. The result shows the optimal two-stage process consisted of the first stage DAP at 428 K for 7 min with 0.8% sulfuric acid, resulting in 79.82% glucose recovery yield and 98.74% xylose removal and the second stage OWEP at 468K for 20 min in 45% (v / v) ethanol with 0.4% NaOH, resulting in 62% total glucose yield 99% xylose and 80% lignin removal. After enzymatic hydrolysis, the glucose yield was up to 92.6%, compared with 16% yield from untreated switch grass. Scanning electron microscopy (SEM) highlighted the differences in switch grass structure from the various pretreatment methods during biomass fractionation.
文摘Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) supported gold catalysts coated with a thin N-doped porous carbon(NPC)layer were developed via a polydopamine-coating-carbonization strategy and utilized for pathway-specific conversion of HMF into 5-methylfurfural(5-MF)with the use of renewable formic acid(FA)as the deoxygenation reagent.The as-fabricated Au/TiO_(2)@NPC exhibited excellent catalytic performance with a high yield of 5-MF(>95%).The catalytic behavior of Au@NPC-based catalysts was shown to be correlated with the suitable combination of highly dispersed Au nanoparticles and favorable interfacial interactions in the Au@NPC core-shell hetero-nanoarchitectures,thereby facilitating the preferential esterification of HMF with FA and suppressing unproductive FA dehydrogenation,which promoted the selective formylation/decarboxylation of hydroxy-methyl group in HMF in a pathway-specific manner.The present NPC/metal interfacial engineering strategy may provide a potential guide for the rational design of advanced catalysts for a wide variety of heterogeneous catalysis processes in terms of the conversion of biomass source.
基金Supported by the State Key Development Program for Basic Research of China(2006BAC02A17)
文摘Bio-fuel can be used to help transition from a petroleum-based society to a bio-based society. Ever since the China Development and Reform Commission suspended the approval of crop processing programs, second-generation bio-ethanol research and industrialization processes have attracted significant attention. In 2020, bio-ethanol production is predicted to reach 10 million tons. Currently, there are a few domestic enterprises that have established different scaled pilot or demonstration bases for cellulosic ethanol, which reduce the cost of ethanol by continuously improving pretreatment and hydrolysis techniques. In the next three years, these enterprises will realize large-scale commercial production. Given the practical problems in cellulosic ethanol plant construction and operation(e.g., marketing price variation and difficulties in feedstock collection), this paper began with the concept of a "whole-crop refinery" and presented a solution to the integration of industry and agriculture as well as multi-crop refining. This paper then took the whole-crop refining system of corn as an example and presented an analysis of the logistics, energy flow, and economical efficiency of the system. The results demonstrated that the integrated system could properly reduce the required fixed investments in production equipment,shared utilities, and wastewater treatment facilities, as well as reduction of energy consumption. Although the proposed system has several problems, it brings the long-term goal of large-scale commercial application closer than ever.
文摘Balance is an essential component of movement and is critical in the ability to participate in physical activity. Developing an exergaming curriculum for schools has the potential to improve balance or postural stability in children. In this study, a purposely-built exergaming center in an elementary school was used to test fourth grade students with a specially designed exergaming curriculum oriented toward improving postural stability. The program was implemented over a 6-week period, 34 min per day, 4-5 days per week. Two control groups were used: (1) a physical education (PE) class geared toward agility, balance, and coordination (ABC) improvement, and (2) a typical PE curriculum class. Exergaming students improved their postural stability significantly over a 6-week period compared to those in the typical PE class. Improvements in postural stability were also evident in the ABC class. Postural stability in the girls was better than the boys in all pre- and post-intervention tests. This study demonstrates that exergaming is a practical resource in the PE class to improve postural stability.
基金Supported by the National Natural Science Foundation of China(Grant No.2156112001)National Basic Science Data Sharing Service Project(DKA2017-12-02-05)
文摘A database-based strategy of candidate generation was proposed for molecular design of new de-phenol extractants following the idea of finding new applications of existing commercial compounds. The strategy has the advantage that the environmental, safety and health risks of candidate compounds are known and controllable. In this work, the Existing Commercial Compounds(ECC) database and special combined search strategy were developed as the base for the proposed CAMD method following such idea, and molecules for phenol extraction used in coking wastewater treatment were selected from the ECC database. The candidate solvents cover the following categories: ketones, esters, ethers, alcohols, anhydrides and benzene compounds, which are consistent with the de-phenol extractants commonly used in the industry or experiment. The compounds with higher partition coefficient and selectivity than widely used methyl isobutyl ketone(MIBK) are mainly ketones. 26 obtained molecules show higher partition coefficient and selectivity than MIBK, which are suggested to be further investigated by experiment. Furthermore, analysis of these potential molecules may present the effective functional groups as the initial group set to generate new molecular structures of de-phenol extractants. The results show that the proposed method enables us to efficiently generate chemicals with benefits of less time, less economical cost, and known environmental impact as well.