This study evaluated the effects of dietary fat levels on the growth, nutrient digestibility, nitrogen balance and pelt characteristics of the blue fox(Alopex lagopus). Age-matched blue foxes(12 weeks old) with simila...This study evaluated the effects of dietary fat levels on the growth, nutrient digestibility, nitrogen balance and pelt characteristics of the blue fox(Alopex lagopus). Age-matched blue foxes(12 weeks old) with similar body weights were randomly divided into six dietary groups over 98 days, during the growing-furring period. Blue foxes in the six groups were fed with experimental diets containing 10%(groupⅠ), 12%(groupⅡ), 14%(group Ⅲ), 16%(group Ⅳ), 18%(groupⅤ) and 20%(group Ⅵ) fat during the growing period(from 13 weeks to 18 weeks of age);foxes were fed with diets containing 12%(groupⅠ), 14%(groupⅡ), 16%(group Ⅲ), 18%(group Ⅳ), 20%(groupⅤ) and 22%(group Ⅵ) fat during the furring period(from 18 weeks to 26 weeks of age). The results indicated that 16%-18% dietary fat, during the growing period significantly improved nutrient utilization, and as a main energy source, significantly reduced the feed/gain ratio. A dietary fat level of 18%, during the furring period not only improved the growth and development and decreased the feed/gain ratio, but also increased nutrient digestibility and fur quality. These data, combined with data from a conic regression model, showed that dietary fat levels between 16.29% and 18.40%, during the growing period and between 17.72% and 18.72%, during the furring period enhanced the growth performance and fur quality of blue foxes.展开更多
To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subseq...To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.展开更多
Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduce...Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduced to less than 0.5 mL, reaction time also largely reduced.展开更多
To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce ...To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce the mass of the sample and the acid. The satisfactory precision is achieved at 2 mg sampling mass.展开更多
This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tes...This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tested. p H, NH3-N, Neutral Detergent Fiber(NDF), Acid Detergent Fiber(ADF), Dry Matter Digestibility(DMD) and the Total Volatile Fatty Acid(TVFA) were measured at 6, 24, 48 h of in vitro mixed incubation the fluids. Microbial populations were determined at 24 h and Microbial Proteins(MCP) were determined at 24 and 48 h. The gas production after 48 h in vitro incubation presented linear growth(p<0.05) and the highest content was the level of 0.5% SPs(dry matter basis). NH3-N concentration reached the highest concentration with 0.75%(dry matter basis) at 48 h. p H linearly increased(linear, p<0.05) from 6 to 48 h. The digestion of DMD increased with increasing doses of SPs at 24 h. NDF and ADF linearly(p<0.01) decreased by adding SPs. The concentration of TVFA linearly increased(p<0.05) at 6, 24 and 48 h, and reached the highest concentration at the level of 0.75%(dry matter basis). SPs decreased(p<0.05) the molar proportion of acetate and propionate, respectively at 24 and 48 h. Acetat to Propionate ratio(A/P; linear, p<0.05) increased at 48 h, and reached the greatest value at the level of 0.75%(dry matter basis) at 48 h. The populations of rumen Ruminococcus flavefaciens(R. flavefaciens), Ruminococcusalbus(R. albus), Fibrobacter succinogenes(F. succinogenes), Butyrivibrio fibrisolvens(B. fibrisolvens), Streptococcus bovis(S.bovis), Ruminobacter amylophilus(R. amylophilus) and Succinimonas amylolytica(S. amylolytica) were analyzed based on the total rumen bacterial 16 S ribosomal deoxyribonucleic acid(r DNA). The relative abundance of R. flavefaciens and R. albus increased at 24 h, but the relative abundance of F. succinogenes decreased at this time. The incubation of SPs had no effect on the abundance of S. bovis and R. amylophilus. The relative abundance of B. fibrisolvens and S. amylolytica reached the greatest value(p<0.05) at middle doses of SPs inclusion at 24 h. The value of MCPs linearly increased(p<0.05) at 24 and 48 h. These results showed that SPs could improve in vitro fermentation and nutrient digestion of feed substrates, and had the ability to modulate the ruminal fermentation pattern by regulating the composition of functional rumen microbes. Hence, SPs might be a potential feed additive applied in the diets of ruminants.展开更多
Eight-month-old Wulong geese were fed with the diet with different proportions of Leymus chiesensis at the same energy and protein level. The activities of plasma Alkaline Phosphatase （AKP）, Acid Phosphatase （ACP）...Eight-month-old Wulong geese were fed with the diet with different proportions of Leymus chiesensis at the same energy and protein level. The activities of plasma Alkaline Phosphatase （AKP）, Acid Phosphatase （ACP）, Choline Esterace （CHE）, Lactic Dehydrogenase （LDH）, Glutamicoxalacetic Transaminase （GOT） and Glutamatepyruvate Transaminase （GPT） were determined and then their correlations with fiber digestibility and the apparent digestibility of Ca, R Met and Cys were analyzed. The results showed that the activity of AKP took on a significant downtrend as the increasing of Leymus chinensis proportion （P〈0.05）. There was a negative correlation between the AKP activity and the digestibility of crude fiber （CF）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） （P〈0.05）. However, there was a significant positive correlation between the AKP activity and the apparent digestibility of Ca, Met and Cys （P〈0.05）. Moreover, the activities of the other five enzymes had no significant correlation with the digestibility of CF, NDF, ADF, and the apparent digestibility of Ca, Met and Cys （P〉0.05）.展开更多
作为抗战胜利后中国共产党支持创办的外文刊物,1946年12月31日至1950年2月1日在香港出版的英文双周刊China Digest(《中国文摘》),不仅发表了大量政治宣传文章,也对中国现代文学尤其是解放区文学进行了集中译介与传播。该刊1949年1月11...作为抗战胜利后中国共产党支持创办的外文刊物,1946年12月31日至1950年2月1日在香港出版的英文双周刊China Digest(《中国文摘》),不仅发表了大量政治宣传文章,也对中国现代文学尤其是解放区文学进行了集中译介与传播。该刊1949年1月11日第5卷第6期刊载了一篇署名"Mao Tun"的英文评论The Characteristics of Modern Chinese Novel(《中国现代小说特征》),为《茅盾全集》所失收。该文体现了作为文学译介者的茅盾积极传播中国现代文学的多样化文化实践活动。展开更多
Inductively coupled plasma mass spectrometry(ICP-MS) was used to determine the concentration of Pb in atmospheric particulate samples,and the enrichment factor was calculated.The causes of the results were also discus...Inductively coupled plasma mass spectrometry(ICP-MS) was used to determine the concentration of Pb in atmospheric particulate samples,and the enrichment factor was calculated.The causes of the results were also discussed.展开更多
In order to enhance the efficiency of aerobic digestion, the excess sludge was irradiated by low intensity ultrasound at a frequency of 28 kHz and acoustic intensity of 0.53 W/cm^2. The results show that the sludge st...In order to enhance the efficiency of aerobic digestion, the excess sludge was irradiated by low intensity ultrasound at a frequency of 28 kHz and acoustic intensity of 0.53 W/cm^2. The results show that the sludge stabilization without ultrasonic treatment can be achieved after 17 d of digestion, whereas the digestion time of ultrasonic groups can be cut by 3-7 d. During the same digestion elapsing, in ultrasonic groups the total volatile suspended solid removal rate is higher than that in the control group. The kinetics of aerobic digestion of excess sludge with ultrasound can also be described with first-order reaction.展开更多
Anaerobic co-digestion of food waste（FW） and rice straw（RS） in continuously stirred tank reactor（CSTR） at high organic loading rate（OLR） was investigated. Co-digestion studies of FW and RS with six different m...Anaerobic co-digestion of food waste（FW） and rice straw（RS） in continuously stirred tank reactor（CSTR） at high organic loading rate（OLR） was investigated. Co-digestion studies of FW and RS with six different mixing ratios were conducted at an initial volatile solid（VS） concentration of more than 3 g VS · L-1. The biogas production, methane contents, degradation efficiency of VS, chemical oxygen demand（COD） and volatile fatty acids（VFAs） were determined to evaluate the stability and performance of the system. The results showed that the co-digestion process had higher system stability and higher volumetric biogas production than mono-digestions. Increase in FW content in the feedstock could increase the methane yield and shorten retention time. The efficiency of co-digestion systems mainly relied on the mixing ratios of FW and RS to some extent. The highest methane yield was 60.55 m L· g V· S-1 · d-1 at a mass ratio（FW/RS） of 3 ： 1, which was 178% and 70% higher than that of mono-digestions of FW and RS, respectively. Consequently, the anaerobic co-digestion of FW and RS could have superior stability and better performance than monodigestions in higher organic loading system.展开更多
Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated...Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated.Elevating temperature,increasing caustic soda concentration,reducing alumina concentration or raising molar ratioαk improved equilibrium concentration of lithium ion in sodium aluminate solution.Agitation speed had a minimal effect on lithium ion concentration.Over 0.65 g/L lithium ion equilibrium concentration was observed in digestion process,whereas 35 mg/L lithium ion concentration remained in solution after precipitation time of 9 h.Moreover,equilibrium concentration decreased sharply from digestion of boehmite or diaspore to seed precipitation,about 95%lithium was precipitated into red mud(bauxite residue)and aluminum hydroxide.This study provides a valuable perspective in removal or extraction of lithium from sodium aluminate solution in alumina refineries.展开更多
The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with...The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and FIE The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material （NIST SRM 1633a）. The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode （maximum mass resolution R=9 000）. The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.展开更多
Hydration grossular and hematite monominerals were synthesized. The effects of dissolved organic compounds(including sodium formate, sodium acetate, sodium oxalate, sodium salicylate or disodium phthalate) on the sett...Hydration grossular and hematite monominerals were synthesized. The effects of dissolved organic compounds(including sodium formate, sodium acetate, sodium oxalate, sodium salicylate or disodium phthalate) on the settling performance of hydration grossular or hematite slurries were studied. The settling of the slurries was also investigated with the addition of sodium polyacrylate(PAAS) or hydroxamated polyacrylamide flocculant(HCPAM). The adsorption mechanism of organic compounds on monominerals surfaces was studied by FT-IR and XPS, respectively. A deterioration in settling is observed in order of disodium phthalate>sodium salicylate>sodium oxalate>sodium formate(or sodium acetate). Moreover, PAAS can efficiently eliminate the negative effects of organic compounds on the settling performance of the hydration grossular slurry. HCPAM can efficiently eliminate the negative effects of sodium formate, sodium acetate and sodium oxalate on the settling performance of the hematite slurry, but it only partially improves the settling performance of hematite slurry containing sodium salicylate or disodium phthalate. FT-IR and XPS results show that organic compounds are physically adsorbed on hydration grossular surface, and chemisorptions of organic compounds occur on hematite surface with a bidentate chelating complex.展开更多
The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methan...The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methane and HzS productions during anaerobic digestion of macroalgae, batch experiments ofMacrocystis pyrifera were carried out. Four groups named C0, C1, C2 and C3 added with 0, 1.5, 3.0 and 4.5 g/g substrate of ceramsite, respectively, were studied and compared. The highest cumulative methane yield of 286.3 mL/g substrate is obtained in C2, which is 40.11% higher than that of CO. The cumulative HzS yields of C1, C2 and C3 are 32.67%, 44.66% and 53.21% lower than that of CO, respectively. Results indicate that ceramsite addition permits higher methane yields, shorter lag-phase time and lower HzS yields during anaerobic digestion of Macrocystispyrifera.展开更多
The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate...The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.展开更多
The operation variables,including feed rate of ore slurry,caustic solution and live steams in the double-stream alumina digestion process,determine the product quality,process costs and the environment pollution.Previ...The operation variables,including feed rate of ore slurry,caustic solution and live steams in the double-stream alumina digestion process,determine the product quality,process costs and the environment pollution.Previously,they were set by the technical workers according to the offline analysis results and an empirical formula,which leads to unstable process indices and high consumption frequently.So,a multi-objective optimization model is built to maintain the balance between resource consumptions and process indices by taking technical indices and energy efficiency as objectives,where the key technical indices are predicted based on the digestion kinetics of diaspore.A multi-objective state transition algorithm(MOSTA)is improved to solve the problem,in which a self-adaptive strategy is applied to dynamically adjust the operator factors of the MOSTA and dynamic infeasible threshold is used to handle constraints to enhance searching efficiency and ability of the algorithm.Then a rule based strategy is designed to make the final decision from the Pareto frontiers.The method is integrated into an optimal control system for the industrial digestion process and tested in the actual production.Results show that the proposed method can achieve the technical target while reducing the energy consumption.展开更多
The profile of hydrolysates during the anaerobic digestion of kitchen wastes was investigated. The experimental results show that the hysteresis of hydrolytic rate is mainly controlled by the diffusion effect. The hyd...The profile of hydrolysates during the anaerobic digestion of kitchen wastes was investigated. The experimental results show that the hysteresis of hydrolytic rate is mainly controlled by the diffusion effect. The hydrolytic mechanism of kitchen wastes is elaborated by taking the diffusion effect into consideration. A segment model of the hydrolysis for kitchen waste is formulated including the coefficient of diffusion resistance in the model. The coefficients of diffusion resistance for different particle sizes are 1.42,2.12 and 2.78 respectively based on the experimental data,in which the coefficients of diffusion resistance conform an exponential function. So,the partitioning kinetic model could be integrated as a unified experience model. The model is verified with experimental data,which shows that the model could predict the concentration of organic substances during the anaerobic digestion of kitchen wastes.展开更多
基金Supported by the Harbin Applied Technology Research and Development Project(2016RAXXJ015)
文摘This study evaluated the effects of dietary fat levels on the growth, nutrient digestibility, nitrogen balance and pelt characteristics of the blue fox(Alopex lagopus). Age-matched blue foxes(12 weeks old) with similar body weights were randomly divided into six dietary groups over 98 days, during the growing-furring period. Blue foxes in the six groups were fed with experimental diets containing 10%(groupⅠ), 12%(groupⅡ), 14%(group Ⅲ), 16%(group Ⅳ), 18%(groupⅤ) and 20%(group Ⅵ) fat during the growing period(from 13 weeks to 18 weeks of age);foxes were fed with diets containing 12%(groupⅠ), 14%(groupⅡ), 16%(group Ⅲ), 18%(group Ⅳ), 20%(groupⅤ) and 22%(group Ⅵ) fat during the furring period(from 18 weeks to 26 weeks of age). The results indicated that 16%-18% dietary fat, during the growing period significantly improved nutrient utilization, and as a main energy source, significantly reduced the feed/gain ratio. A dietary fat level of 18%, during the furring period not only improved the growth and development and decreased the feed/gain ratio, but also increased nutrient digestibility and fur quality. These data, combined with data from a conic regression model, showed that dietary fat levels between 16.29% and 18.40%, during the growing period and between 17.72% and 18.72%, during the furring period enhanced the growth performance and fur quality of blue foxes.
文摘To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.
文摘Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduced to less than 0.5 mL, reaction time also largely reduced.
文摘To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce the mass of the sample and the acid. The satisfactory precision is achieved at 2 mg sampling mass.
基金the China Agricultural Research System for providing facility and funds for experiment
文摘This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tested. p H, NH3-N, Neutral Detergent Fiber(NDF), Acid Detergent Fiber(ADF), Dry Matter Digestibility(DMD) and the Total Volatile Fatty Acid(TVFA) were measured at 6, 24, 48 h of in vitro mixed incubation the fluids. Microbial populations were determined at 24 h and Microbial Proteins(MCP) were determined at 24 and 48 h. The gas production after 48 h in vitro incubation presented linear growth(p<0.05) and the highest content was the level of 0.5% SPs(dry matter basis). NH3-N concentration reached the highest concentration with 0.75%(dry matter basis) at 48 h. p H linearly increased(linear, p<0.05) from 6 to 48 h. The digestion of DMD increased with increasing doses of SPs at 24 h. NDF and ADF linearly(p<0.01) decreased by adding SPs. The concentration of TVFA linearly increased(p<0.05) at 6, 24 and 48 h, and reached the highest concentration at the level of 0.75%(dry matter basis). SPs decreased(p<0.05) the molar proportion of acetate and propionate, respectively at 24 and 48 h. Acetat to Propionate ratio(A/P; linear, p<0.05) increased at 48 h, and reached the greatest value at the level of 0.75%(dry matter basis) at 48 h. The populations of rumen Ruminococcus flavefaciens(R. flavefaciens), Ruminococcusalbus(R. albus), Fibrobacter succinogenes(F. succinogenes), Butyrivibrio fibrisolvens(B. fibrisolvens), Streptococcus bovis(S.bovis), Ruminobacter amylophilus(R. amylophilus) and Succinimonas amylolytica(S. amylolytica) were analyzed based on the total rumen bacterial 16 S ribosomal deoxyribonucleic acid(r DNA). The relative abundance of R. flavefaciens and R. albus increased at 24 h, but the relative abundance of F. succinogenes decreased at this time. The incubation of SPs had no effect on the abundance of S. bovis and R. amylophilus. The relative abundance of B. fibrisolvens and S. amylolytica reached the greatest value(p<0.05) at middle doses of SPs inclusion at 24 h. The value of MCPs linearly increased(p<0.05) at 24 and 48 h. These results showed that SPs could improve in vitro fermentation and nutrient digestion of feed substrates, and had the ability to modulate the ruminal fermentation pattern by regulating the composition of functional rumen microbes. Hence, SPs might be a potential feed additive applied in the diets of ruminants.
文摘Eight-month-old Wulong geese were fed with the diet with different proportions of Leymus chiesensis at the same energy and protein level. The activities of plasma Alkaline Phosphatase （AKP）, Acid Phosphatase （ACP）, Choline Esterace （CHE）, Lactic Dehydrogenase （LDH）, Glutamicoxalacetic Transaminase （GOT） and Glutamatepyruvate Transaminase （GPT） were determined and then their correlations with fiber digestibility and the apparent digestibility of Ca, R Met and Cys were analyzed. The results showed that the activity of AKP took on a significant downtrend as the increasing of Leymus chinensis proportion （P〈0.05）. There was a negative correlation between the AKP activity and the digestibility of crude fiber （CF）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） （P〈0.05）. However, there was a significant positive correlation between the AKP activity and the apparent digestibility of Ca, Met and Cys （P〈0.05）. Moreover, the activities of the other five enzymes had no significant correlation with the digestibility of CF, NDF, ADF, and the apparent digestibility of Ca, Met and Cys （P〉0.05）.
文摘作为抗战胜利后中国共产党支持创办的外文刊物,1946年12月31日至1950年2月1日在香港出版的英文双周刊China Digest(《中国文摘》),不仅发表了大量政治宣传文章,也对中国现代文学尤其是解放区文学进行了集中译介与传播。该刊1949年1月11日第5卷第6期刊载了一篇署名"Mao Tun"的英文评论The Characteristics of Modern Chinese Novel(《中国现代小说特征》),为《茅盾全集》所失收。该文体现了作为文学译介者的茅盾积极传播中国现代文学的多样化文化实践活动。
文摘Inductively coupled plasma mass spectrometry(ICP-MS) was used to determine the concentration of Pb in atmospheric particulate samples,and the enrichment factor was calculated.The causes of the results were also discussed.
文摘In order to enhance the efficiency of aerobic digestion, the excess sludge was irradiated by low intensity ultrasound at a frequency of 28 kHz and acoustic intensity of 0.53 W/cm^2. The results show that the sludge stabilization without ultrasonic treatment can be achieved after 17 d of digestion, whereas the digestion time of ultrasonic groups can be cut by 3-7 d. During the same digestion elapsing, in ultrasonic groups the total volatile suspended solid removal rate is higher than that in the control group. The kinetics of aerobic digestion of excess sludge with ultrasound can also be described with first-order reaction.
基金Supported by the Natural Science Foundation of Heilongjiang Province(QC2014C031)Returned Overseas Foundation of Heilongjiang Province(LC2013C07)+2 种基金Outstanding Academic Leaders Foundation of Harbin City(2013RFXYJ015)Young Reserve Talent Foundation of Harbin City(2014RFQYJ141)Outstanding Young Foundation of Heilongjiang Academy of Agricultural Sciences(2013JCQN003)
文摘Anaerobic co-digestion of food waste（FW） and rice straw（RS） in continuously stirred tank reactor（CSTR） at high organic loading rate（OLR） was investigated. Co-digestion studies of FW and RS with six different mixing ratios were conducted at an initial volatile solid（VS） concentration of more than 3 g VS · L-1. The biogas production, methane contents, degradation efficiency of VS, chemical oxygen demand（COD） and volatile fatty acids（VFAs） were determined to evaluate the stability and performance of the system. The results showed that the co-digestion process had higher system stability and higher volumetric biogas production than mono-digestions. Increase in FW content in the feedstock could increase the methane yield and shorten retention time. The efficiency of co-digestion systems mainly relied on the mixing ratios of FW and RS to some extent. The highest methane yield was 60.55 m L· g V· S-1 · d-1 at a mass ratio（FW/RS） of 3 ： 1, which was 178% and 70% higher than that of mono-digestions of FW and RS, respectively. Consequently, the anaerobic co-digestion of FW and RS could have superior stability and better performance than monodigestions in higher organic loading system.
基金Project(2015BAB04B01)supported by the National Key Technology R&D Program of ChinaProject(FA2017029)supported by Science and Technology Program of Chongzuo,ChinaProject(CSUZC201811)supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘Excess lithium in alumina is significantly bad for aluminum reduction.In this study,the concentration variation of lithium ion in sodium aluminate solution with addition of synthetic lithium aluminate was investigated.Elevating temperature,increasing caustic soda concentration,reducing alumina concentration or raising molar ratioαk improved equilibrium concentration of lithium ion in sodium aluminate solution.Agitation speed had a minimal effect on lithium ion concentration.Over 0.65 g/L lithium ion equilibrium concentration was observed in digestion process,whereas 35 mg/L lithium ion concentration remained in solution after precipitation time of 9 h.Moreover,equilibrium concentration decreased sharply from digestion of boehmite or diaspore to seed precipitation,about 95%lithium was precipitated into red mud(bauxite residue)and aluminum hydroxide.This study provides a valuable perspective in removal or extraction of lithium from sodium aluminate solution in alumina refineries.
基金Project (04JJ40016) supported by the Natural Science Foundation of Hunan Province, China
文摘The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and FIE The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material （NIST SRM 1633a）. The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode （maximum mass resolution R=9 000）. The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.
基金Project(51174231)supported by the National Natural Science Foundation of China
文摘Hydration grossular and hematite monominerals were synthesized. The effects of dissolved organic compounds(including sodium formate, sodium acetate, sodium oxalate, sodium salicylate or disodium phthalate) on the settling performance of hydration grossular or hematite slurries were studied. The settling of the slurries was also investigated with the addition of sodium polyacrylate(PAAS) or hydroxamated polyacrylamide flocculant(HCPAM). The adsorption mechanism of organic compounds on monominerals surfaces was studied by FT-IR and XPS, respectively. A deterioration in settling is observed in order of disodium phthalate>sodium salicylate>sodium oxalate>sodium formate(or sodium acetate). Moreover, PAAS can efficiently eliminate the negative effects of organic compounds on the settling performance of the hydration grossular slurry. HCPAM can efficiently eliminate the negative effects of sodium formate, sodium acetate and sodium oxalate on the settling performance of the hematite slurry, but it only partially improves the settling performance of hematite slurry containing sodium salicylate or disodium phthalate. FT-IR and XPS results show that organic compounds are physically adsorbed on hydration grossular surface, and chemisorptions of organic compounds occur on hematite surface with a bidentate chelating complex.
基金Project(2014BAC31B01)supported by the National Science&Technology Support during the 12th Five-Year Plan Period,ChinaProjects(2015GSF117016,2015GSF115037)supported by the Key Research&Development Project of Shandong Province,China
文摘The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methane and HzS productions during anaerobic digestion of macroalgae, batch experiments ofMacrocystis pyrifera were carried out. Four groups named C0, C1, C2 and C3 added with 0, 1.5, 3.0 and 4.5 g/g substrate of ceramsite, respectively, were studied and compared. The highest cumulative methane yield of 286.3 mL/g substrate is obtained in C2, which is 40.11% higher than that of CO. The cumulative HzS yields of C1, C2 and C3 are 32.67%, 44.66% and 53.21% lower than that of CO, respectively. Results indicate that ceramsite addition permits higher methane yields, shorter lag-phase time and lower HzS yields during anaerobic digestion of Macrocystispyrifera.
基金Projects(U1202274,51004033,51204040,50974035)supported by the National Natural Science Foundation of ChinaProjects(2010AA03A405,2012AA062303)supported by the National High Technology Research and Development Program(863 Prograam)of ChinaProject(N100302005)supported by the Fundamental Research Funds for the Central Universities,China
文摘The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment.
基金Project(62073342)supported by the National Natural Science Foundation of ChinaProject(2014 AA 041803)supported by the Hi-tech Research and Development Program of China。
文摘The operation variables,including feed rate of ore slurry,caustic solution and live steams in the double-stream alumina digestion process,determine the product quality,process costs and the environment pollution.Previously,they were set by the technical workers according to the offline analysis results and an empirical formula,which leads to unstable process indices and high consumption frequently.So,a multi-objective optimization model is built to maintain the balance between resource consumptions and process indices by taking technical indices and energy efficiency as objectives,where the key technical indices are predicted based on the digestion kinetics of diaspore.A multi-objective state transition algorithm(MOSTA)is improved to solve the problem,in which a self-adaptive strategy is applied to dynamically adjust the operator factors of the MOSTA and dynamic infeasible threshold is used to handle constraints to enhance searching efficiency and ability of the algorithm.Then a rule based strategy is designed to make the final decision from the Pareto frontiers.The method is integrated into an optimal control system for the industrial digestion process and tested in the actual production.Results show that the proposed method can achieve the technical target while reducing the energy consumption.
文摘The profile of hydrolysates during the anaerobic digestion of kitchen wastes was investigated. The experimental results show that the hysteresis of hydrolytic rate is mainly controlled by the diffusion effect. The hydrolytic mechanism of kitchen wastes is elaborated by taking the diffusion effect into consideration. A segment model of the hydrolysis for kitchen waste is formulated including the coefficient of diffusion resistance in the model. The coefficients of diffusion resistance for different particle sizes are 1.42,2.12 and 2.78 respectively based on the experimental data,in which the coefficients of diffusion resistance conform an exponential function. So,the partitioning kinetic model could be integrated as a unified experience model. The model is verified with experimental data,which shows that the model could predict the concentration of organic substances during the anaerobic digestion of kitchen wastes.
