Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surfac...Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surface pretreatment experiments with citric acid,tartaric acid,and tannic acid(TA)on magnesite and dolomite as well as flotation experiments on pretreated samples were performed in this study.Experimental results demonstrated that when citric acid and tartaric acid are used for surface pretreatment,the separation effect of magnesite and dolomite is poor.However,when TA is used,the separation effect of magnesite and dolomite improves.SEM and BET analysis indicated that surface pretreatment with TA changes the surface morphology of the two minerals,resulting in additional concave pores on the dolomite surface,and a significant increase in pore size and specific surface area.The adsorption quantity test and contact angle measurement demonstrated that after surface pretreatment with TA,the magnesite adsorption capacity on sodium oleate(NaOL)slightly decreases and the dolomite adsorption capacity on NaOL considerably decreases.XPS detection concluded that the surface pretreatment of TA on the magnesite surface mainly relies on physical adsorption with weak adsorption ability and poor ability to act on Mg sites.The TA surface pretreatment action on the dolomite surface is mainly through chemical adsorption,and it is strongly and selectively adsorbed on the Ca site of dolomite through O.Actual ore rough selection experiments reveal that TA pretreatment successfully removes dolomite from magnesite,resulting in a high-quality magnesite concentrate characterized by a MgO grade of 45.49%and a CaO grade of 0.75%.展开更多
The influence of refining flux composition,refining time,refining temperature,and addition amount on the microstructure and mechanical properties of Mg-9Li-3Al-1Zn alloy was investigated with orthogonal experimental d...The influence of refining flux composition,refining time,refining temperature,and addition amount on the microstructure and mechanical properties of Mg-9Li-3Al-1Zn alloy was investigated with orthogonal experimental design.The flux purification process for Mg-Li alloys was optimized and the most effective ternary flux composition was identified.Results indicate that flux purification significantly mitigates Li loss during smelting by forming a protective surface layer that reduces Li oxidation and evaporation.The optimal flux composition is LiCl:LiF:CaF_(2)in a 3:1:2 mass ratio,with a flux addition of 3%,refining temperature of 720°C,and holding time of 10 min.The elongation of alloy improves to 16.2% after refinement,while the enhancement in strength remains marginal.展开更多
By adding zeolite aggregate with good adsorption properties,different mix ratios of added zeolite pervious concrete(ZPC)were designed to compare the water purification effect of ordinary pervious concrete and water pu...By adding zeolite aggregate with good adsorption properties,different mix ratios of added zeolite pervious concrete(ZPC)were designed to compare the water purification effect of ordinary pervious concrete and water purification tests that were conducted.The pore characteristics of the pervious concrete were identified using three-dimensional reconstruction software and the relationship between pore structure and water purification performance was quantified by gray entropy correlation analysis.The results showed that the purification efficiency of zeolite-doped pervious concrete was 17.6%-22.3%higher than that of ordinary pervious concrete.The characteristic parameters of the pore structure of permeable concrete,i.e.planar porosity and tortuosity,were determined using three-dimensional reconstruction software.The correlation between the degree of tortuosity and the removal rate reached more than 0.90,indicating that the internal pore structure of pervious concrete has a good correlation with the water purification performance.展开更多
[Objective] The effect of baffled surface flow wetlands on water purification was studied in order to provide a reference for the ecological restoration of polluted river.[Method] Contents of some indexes like DO,TN,T...[Objective] The effect of baffled surface flow wetlands on water purification was studied in order to provide a reference for the ecological restoration of polluted river.[Method] Contents of some indexes like DO,TN,TP,NH＋4-N,CODCr,SS,SD,etc.were determined in the band baffled surface flow wetlands with total area of 7 400 m2 at JiaLu riverside.[Result] Baffled surface flow wetlands could improve the effluent quality significantly,could enhance transparency and dissolved oxygen content and also could decrease SS content.The removal rate of TN was kept at more than 73% in summer and decreased to 23% in early winter;The removal rate of TP was little influenced by temperature,and it was kept at more than 77% in summer and still kept at more than 69% in autumn and winter;The removal rate of NH＋4-N was kept at more than 83% in summer and decreased slightly in autumn and winter,but still kept at more than 75%;The removal rate of CODCr ranged from 14% to 50%.[Conclusion] Baffled surface flow wetlands could effectively improve the purification effect of surface flow wetlands,which is a feasible way for ecological restoration.展开更多
[Objective]The activities of urease and phosphatase in integrated vertical flow constructed wetland and purification effect of black and malodorous river were studied.[Method]Honeycomb stone and soft filler were used ...[Objective]The activities of urease and phosphatase in integrated vertical flow constructed wetland and purification effect of black and malodorous river were studied.[Method]Honeycomb stone and soft filler were used as matrix,the biological grid integrated vertical flow constructed wetland system was built to strengthen treatment for black and malodorous river,and the activities of urease and phosphatase of two fillers in different functional areas of constructed wetland were tested to study the film formation property of two fillers in different functional areas.[Result]Both urease and phosphatase activities on biofilm of soft filler were significantly higher than on biofilm of honeycomb stone filler;indicating that choosing soft filler was more advantageous to the growth of biofilm;and urease activity had significant correlation with total nitrogen removal rate,while phosphatase activity had no significant correlation with total phosphorus removal rate.[Conclusion]This study provided evidences for utilizing the activities of urease and phosphatase to evaluate the purification effect of black and malodorous river and choose appropriate filler.展开更多
[Objective] To study the purification effect of plant community on wetland water environment in Hongze Lake, and to provide references to the ecological restoration of this area. [Methed] The typical lakeside zone of ...[Objective] To study the purification effect of plant community on wetland water environment in Hongze Lake, and to provide references to the ecological restoration of this area. [Methed] The typical lakeside zone of Hongze Lake Wetland National Nature Reserve was taken as the study area. Through the field survey based on environmental characteristics of aquatic areas and non-aquatic areas, combined with laboratory test, the content changes of nutrients （N and P）, COD （chemical oxygen demand） and SD （transparency） levels in the water body of lake wetland were measured; the purification effect of the lake wetland ecosystem in the growth process of aquatic vegetation was quantitatively analyzed, and possible influ- encing factors were discussed. [Result] Aquatic vegetation could remove the TN, TP, COD, Chla in wetland water environment and had obvious effects on the changes of SD content. Competition between aquatic plants can inhibit the growth of algae and relieve the eutrophication of water body. [Conclusion] This study provided theoretical basis for ecological restoration and enhancement of self-purification capability in the lakeside zone of Hongze Lake.展开更多
Mg-Gd-Y-Zr alloys were purified by filtering purification with and without vacuum. The type, morphology, size distribution and volume fraction of inclusion were analyzed with OM and SEM. The effect of inclusion in Mg-...Mg-Gd-Y-Zr alloys were purified by filtering purification with and without vacuum. The type, morphology, size distribution and volume fraction of inclusion were analyzed with OM and SEM. The effect of inclusion in Mg-Gd-Y-Zr alloys on anticorrosion ability was investigated with salt spray test and electrochemical test. The results show that the inclusions in the alloy can be removed effectively by filtering purification. The average size of inclusions in the alloys is decreased from 12.7 μm to 2.0 μm and the volume fraction of inclusions is reduced from 0.30% to 0.04%. With the decrease of the size of inclusions in the alloys, the corrosion rate of the alloys decreases dramatically from 38.8 g/（m 2 ·d） to 2.4 g/（m 2 ·d） in the salt spray test. The corrosion potential increases while the corrosion current decreases and the polarization resistance increases in the electrochemical tests, which indicates that the anticorrosion ability is improved.展开更多
To improve the poor stability of casting process of Al alloy with high Mg content, which leads to poor final product quality, the melting purification process and the influences of the refiner on the microstructure an...To improve the poor stability of casting process of Al alloy with high Mg content, which leads to poor final product quality, the melting purification process and the influences of the refiner on the microstructure and defect of 5083 alloy were studied. The results show that the optimized process for the rotary impeller degassing of 5083 alloy is as follows： a rotary speed of 250-400 r/min; a gas flow of 1.2-2.0 L/s, a refining time of 10-15 min. This optimized process can reduce the gas content in the solid alloy to 2× 10^-3 mL/g or lower. Due to the addition of grain refiner, the cast microstructure of 5083 alloy is refined. The Al-5Ti-IB wire shows the best refining effect among all the refiners. The refining effect is improved with the increase of grain refiner addition amount. And the refinement effects become stable when Ti content reaches 0.1% or higher. The surface crinkling defect of the billet can be easily found in the alloy refined with Al-5Ti-IB wire compared with the alloys refined with other refiners.展开更多
As the main external pollution source of lake,nitrogen and phosphorus from agricultural non-point source make a great contribution to the lake eutrophication pollution.Wetland lakefront zone which plays a key role in ...As the main external pollution source of lake,nitrogen and phosphorus from agricultural non-point source make a great contribution to the lake eutrophication pollution.Wetland lakefront zone which plays a key role in externally agricultural non-point source pollution is considered as the biggest barrier for controlling external pollution.In this research,the Jian lake plateau Zizania latifolia wetland lakefront zone was selected for agricultural non-point source pollutions control with the systematic field research,and the lakefront zone was approved to have an effective purification effect on nitrogen and phosphorus from Jinlong River; the theoretical mechanism of lakefront zone removing nutrient was also investigated.Z.latifolia wetland lakefront zone could remove nitrogen and phosphorus from Jinlong River and the removal ratio can reach 55.8-62.52% and 59.47-69.81% respectively.So,we can indicate that the Jian Lake plateau Z.latifolia wetland lakefront zone had a good effect on controlling agricultural non-point source pollution and protecting the environment.展开更多
Due to the formation of disinfection by-products and high concentrations of Al residue in drinking water purification, humic substances are a major component of organic matter in natural waters and have therefore rece...Due to the formation of disinfection by-products and high concentrations of Al residue in drinking water purification, humic substances are a major component of organic matter in natural waters and have therefore received a great deal of attention in recent years. We investigated the effects of advanced oxidation pretreatment methods usually applied for removing dissolved organic matters on residual Al control. Results showed that the presence of humic acid increased residual Al concentration notably. With 15 mg/L of humic acid in raw water, the concentrations of soluble aluminum and total aluminum in the treated water were close to the quantity of Al addition. After increasing coagulant dosage from 12 to 120 mg/L, the total-Al in the treated water was controlled to below 0.2 mg/L. Purification systems with ozonation, chlorination, or potassium permanganate oxidation pretreatment units had little effects on residual Al control; while UV radiation decreased Al concentration notably. Combined with ozonation, the effects of UV radiation were enhanced. Optimal dosages were 0.5 mg O 3 /mg C and 3 hr for raw water with 15 mg/L of humic acid. Under UV light radiation, the combined forces or bonds that existed among humic acid molecules were destroyed; adsorption sites increased positively with radiation time, which promoted adsorption of humic acid onto polymeric aluminum and Al（OH） 3 （s）. This work provides a new solution for humic acid coagulation and residual Al control for raw water with humic acid purification.展开更多
Hydrogen purification must be done to meet the different purposes of hydrogen utilization.In the present work,it is confirmed that the catalyst Ni/CeO2 has the highest activity for total methanation(Total MET) of CO a...Hydrogen purification must be done to meet the different purposes of hydrogen utilization.In the present work,it is confirmed that the catalyst Ni/CeO2 has the highest activity for total methanation(Total MET) of CO and CO2,and is thus most suitable for hydrogen purification for ammonia synthesis.While,the catalyst Ni/ZrO2 appears the best one for selective methanation of CO(CO-SMET) in the H2-rich gas to produce clean fuel for proton exchange membrane fuel cell(PEMFC).In spite of this,the catalyst Ni/ZrO2 without adding chlorine ions as promoter is not yet capable of removing the CO in the reformate gas to below 10 ppm in a wide reaction temperature range by the way of CO-SMET.Adding chlorine ions as promoter is indeed not favorable for practical application due to its gradual loss in the catalytic reaction as proved in our previous work.Therefore,a step to decrease CO2 concentration(called as de-CO2 step) is suggested to be set prior to the CO-SMET step in this work.It is proved that such combination of de-CO2 step and CO-SMET step is efficient to achieve a deep removal of CO to below 10 ppm with a high selectivity more than 50% in a wide reaction temperature range of 220-280℃over the catalyst Ni/ZrO2 without adding chlorine ions as promoter.The combined process has potential for practical application,at least in the large-scale power plant of PEMFC.展开更多
AIM To extract and purify the transforming growth factor β (TGF β), and to demonstrate its biological activity in vivo and induction of apoptosis of hepatocytes in vitro.METHODS TGF β was isolated from fresh bovine...AIM To extract and purify the transforming growth factor β (TGF β), and to demonstrate its biological activity in vivo and induction of apoptosis of hepatocytes in vitro.METHODS TGF β was isolated from fresh bovine platelets by acid/ethanol extraction method and purified with ion exchange and gel chromatography. The extracted TGF β was injected subcutaneously to mice, and its biological activity in vivo was observed 72 hfs post-injection by HE staining. The morphological changes were observed by HE staining and the occurrence of apoptosis was detected by TUNEL method after the human normal hepatic cell line QZG was treated with 8 μg@L 1 TGFβ for 12 hrs in vitro.RESULTS The molecular mass 25 ku TGF β protein was successfully extracted. It was able to induce localized granulation tissue formation in vivo. TGF β-treated hepatocytes showed obvious apoptotic morphological changes, including the pyknosis and dense-stained nuclei and cytoplasm, the fragmentary, annular or crescent nuclei, and the "bubbling" cytoplasm. Moreover, its apoptotic rate was significantly higher than that of the control group (P＜0.05).CONCLUSION Biological active TGF β protein is extracted and purified successfully from bovine platelets, and it is able to induce the apoptosis of hepatocytes.展开更多
Recombinant ancylostoma caninum anticoagulant peptide-5 （rAcAP5） has been reported to inhibit thrombin-activatable fibrinolysis inhibitor （TAFIa） activity and have thrombolytic effect. The present study was to scr...Recombinant ancylostoma caninum anticoagulant peptide-5 （rAcAP5） has been reported to inhibit thrombin-activatable fibrinolysis inhibitor （TAFIa） activity and have thrombolytic effect. The present study was to screen a strain expressing high-yield of rAcAP5 and to assess its thrombolytic effect on embolic middle cerebral artery occlusion （MCAO） model in rats. Codons encoding for AcAP5 were optimized. Six expression plasmids and eleven E. coli strains with different characteristics were used, a total of 66 recombinant expression strains were generated and the one with the highest yield was selected to express rAcAP5, which was purified through anion- and cation-exchange chromatography. The purity of rAcAP5 and its molecular weight were determined by HPLC and mass spectrometry, respectively. The thrombolytic effect of rAcAP5 was evaluated on embolic MCAO model in rats; regional cerebral blood flow （rCBF） was monitored with a Laser-Doppler flowmetry to test the occlusion and recanalization of MCA. The highest yield recombinant strain was C2566H/pTYB 1-rAcAP5. AcAP5 （28 mg） with 90% of purity was obtained from 1 L of cell culture. In rat embolic MCAO model, vehicle （normal saline） treatment did not change the rCBF, while treatment with rAcAP5 （50-200 μg/kg, i.v.） increased the rCBF in a dose-dependent manner. In conclusion, we prepared and characterized the rAcAP5 peptide and revealed its thrombolytic effect in embolic MCAO model and our results suggested that this peptide had the potential to be used as a thrombolytic agent.展开更多
Phycoerythrin, as the main light-harvesting antenna in Porphyridium purpureum, exists at the outermost end of the phycobilisome. It has advantages of good fluorescence intensity, anti-oxidation, scavenging free radica...Phycoerythrin, as the main light-harvesting antenna in Porphyridium purpureum, exists at the outermost end of the phycobilisome. It has advantages of good fluorescence intensity, anti-oxidation, scavenging free radicals, and high chroma, so it has been widely used in food, cosmetics, pharmaceuticals, and other industries. In this study, the effects of different extraction(ultrasonic breaking method, bead grinding method, liquid nitrogen grinding method, and freezing-thawing method) and purification methods(salting out method, ultrafiltration method, and combination of salting out and ultrafiltration method) on the acquisition of phycoerythrin from P. purpureum were studied, and the characteristics of phycoerythrin in the P. purpureum were identified. The results showed that the freezing-thawing method could extract phycoerythrin from the powder of P. purpureum to the utmost extent, and the concentration of the extracted phycoerythrin was up to 0.036 g/L. The salting out method could most effectively purify phycoerythrin, and the purity index was 2.216. The identification of phycoerythrin by ultraviolet absorption spectroscopy and fluorescence spectroscopy indicated that the phycoerythrin had the maximum absorption peak at 545 nm, and the maximum Stokes shift was up to 79 nm. Due to its high fluorescence characteristics, it can be used as a fluorescent marker in the fields of molecular biology and clinical medicine, and can also be used as a good photosensitizer in tumor therapy.展开更多
Mg-Gd-Y-Zr alloy was purified by the method of filtering purification. The type, morphology, size distribution and volume fraction of inclusions in the alloy were analyzed using optical microscope and scanning electro...Mg-Gd-Y-Zr alloy was purified by the method of filtering purification. The type, morphology, size distribution and volume fraction of inclusions in the alloy were analyzed using optical microscope and scanning electron microscope, and the effects of the inclusions on the mechanical and corrosion properties of the alloy were investigated. The results indicate that the filtering purification method is effective to remove inclusions in the alloy. By the filtering purification method, the average size of inclusions in the alloy reduces from 12.7 μm to 4.3 μm and the average volume fraction of inclusions in the alloy reduces from 0.26% to 0.06%. The ultimate tensile strength, yield strength and elongation of the alloy are improved from 200 MPa, 156 MPa and 3.4% to 232 MPa, 167 MPa and 7.0%, respectively. The corrosion rate of the alloy decreases dramatically from 38.8g/（mLd） to 2.5 g/（mZ.d） in the salt spray test.展开更多
The effects of trace element Fe on the corrosion behavior of AZ80 magnesium alloy were investigated by salt spray test and electrochemical measurements.The results show that the corrosion rate decreases with decreasin...The effects of trace element Fe on the corrosion behavior of AZ80 magnesium alloy were investigated by salt spray test and electrochemical measurements.The results show that the corrosion rate decreases with decreasing the trace element Fe content in an approximately linear relation even though the amount of trace element Fe reduces to 0.000 2%(mass fraction).The electrochemical measurements show that the corrosion potential(φcorr)of the alloy with lower trace element Fe content shifts to less negative value.It is suggested that the control trace element by purification is an effective way to enhance the corrosion resistance of AZ80 magnesium alloy.展开更多
The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate im...The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.展开更多
A water-soluble polysaccharide,designated BFP-3,was isolated from Bangia fuscopurpurea by hot water extraction,anion-exchange,and size-exclusion chromatography and tested to determine its antitumor activity.The struct...A water-soluble polysaccharide,designated BFP-3,was isolated from Bangia fuscopurpurea by hot water extraction,anion-exchange,and size-exclusion chromatography and tested to determine its antitumor activity.The structural characteristics of BFP-3 were investigated by chemical and spectroscopic methods,including partial acid hydrolysis,methylation analysis,one-and two-dimensional nuclear magnetic resonance,and gas chromatography-mass spectrometry.The results showed that BFP-3 was mainly comprised of rhamnose,arabinose,mannose,glucose,and galactose.Moreover,the weight-average molecular weight of BFP-3 was estimated to be approximately 333 kDa.The backbone of BFP-3 was primarily composed of repeating 5-α-l-Araf-1→(4-α-d-Glcp-1)_(4)→4,6-β-d-Manp-1 units,and the side chains consisted of repeatingβ-d-Galp-1→(4-β-d-Galp-1)_(4)→4,6-β-d-Galp-1→3,4-α-l-Rhap,β-l-Arap-1→(3-β-d-Galp-1)_(3),andβ-l-Arap-1 units.Counting Kit-8 assays revealed that BFP-3 significantly inhibited the proliferation of A2780,COC1,SKOV3,HO-8910,and OVCAR3 ovarian cancer cells in vitro,indicating that BFP-3 could have potential applications in the treatment of ovarian cancer.展开更多
A synthetic biological pond composed of aquatic plants, a microorganism and aquatic animals was applied in the purification of the wastewater discharged from a Tnonyx sinensis breeding greenhouse, and the removal effe...A synthetic biological pond composed of aquatic plants, a microorganism and aquatic animals was applied in the purification of the wastewater discharged from a Tnonyx sinensis breeding greenhouse, and the removal effects of TN, NH4＋ -N, TP and COD in the wastewater were analyzed. The results show that after the breeding wastewater was purified by the synthetic biological pond for about five months, TN, NH~ -N, TP and COD concentration in the breeding wastewater were reduced by 78%, 92%, 81% and 60% respectively, while DO content in the breeding wastewater increased by about four times, and there was no obvious change in water pH; previous yellow or brown and turbid sewage became yel- lowish and slightly turbid, and it had no smell. It is obviously seen that the purification effect of T. sinensis breeding wastewater by the synthetic biological pond composed of aquatic plants, a microorganism and aquatic animals is obvious, and the synthetic biological pond has good promotion and application prospects.展开更多
The effects of several fluxes on purification,microstructures and properties of A00 aluminum have been studied.The experimental results and analyses indicate that many cracks and large porosities exist in the surface ...The effects of several fluxes on purification,microstructures and properties of A00 aluminum have been studied.The experimental results and analyses indicate that many cracks and large porosities exist in the surface film above the melt purified by C2Cl6 and that the film is floc and mostly composed of Al 2 O 3 and pure aluminum,which carries many carbon particles and AlCl 3 not fully volatilized.And then over 50%(mass fraction) of the all-melting residue is pure aluminum,which is one of the major reasons for high melting loss.Moreover,because of a mass of gas bubbles and a state of seethe,there are many inclusions which size is under 10 μ m in the microstructure of A00 aluminum purified with C2Cl6 or fluxes containing C2Cl6.With this purifying method,the aluminum crystal grains are extended along the radius that was observed firstly and the average crystal size of A00 aluminum are about 100-150 μ m.In addition,small size inclusions have little affected on tensile strength and micro inclusions under 10 μ m have little affected on elongation.展开更多
基金Project(BGRIMM-KJSKL-2024-07) supported by the Open Foundation of State Key Laboratory of Mineral Processing,ChinaProjects(52374259,52174239) supported by the National Natural Science Foundation of China。
文摘Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surface pretreatment experiments with citric acid,tartaric acid,and tannic acid(TA)on magnesite and dolomite as well as flotation experiments on pretreated samples were performed in this study.Experimental results demonstrated that when citric acid and tartaric acid are used for surface pretreatment,the separation effect of magnesite and dolomite is poor.However,when TA is used,the separation effect of magnesite and dolomite improves.SEM and BET analysis indicated that surface pretreatment with TA changes the surface morphology of the two minerals,resulting in additional concave pores on the dolomite surface,and a significant increase in pore size and specific surface area.The adsorption quantity test and contact angle measurement demonstrated that after surface pretreatment with TA,the magnesite adsorption capacity on sodium oleate(NaOL)slightly decreases and the dolomite adsorption capacity on NaOL considerably decreases.XPS detection concluded that the surface pretreatment of TA on the magnesite surface mainly relies on physical adsorption with weak adsorption ability and poor ability to act on Mg sites.The TA surface pretreatment action on the dolomite surface is mainly through chemical adsorption,and it is strongly and selectively adsorbed on the Ca site of dolomite through O.Actual ore rough selection experiments reveal that TA pretreatment successfully removes dolomite from magnesite,resulting in a high-quality magnesite concentrate characterized by a MgO grade of 45.49%and a CaO grade of 0.75%.
基金financially supported by the National Defense Basic Research Program,China(No.JCKY2023204A005)Foundation Strengthening Plan Technical Field Fund,China(No.2021-JJ-0112)+1 种基金Major Scientific and Technological Innovation Project of Luoyang,China(No.2201029A)the National Natural Science Foundation of China(No.U2037601).
文摘The influence of refining flux composition,refining time,refining temperature,and addition amount on the microstructure and mechanical properties of Mg-9Li-3Al-1Zn alloy was investigated with orthogonal experimental design.The flux purification process for Mg-Li alloys was optimized and the most effective ternary flux composition was identified.Results indicate that flux purification significantly mitigates Li loss during smelting by forming a protective surface layer that reduces Li oxidation and evaporation.The optimal flux composition is LiCl:LiF:CaF_(2)in a 3:1:2 mass ratio,with a flux addition of 3%,refining temperature of 720°C,and holding time of 10 min.The elongation of alloy improves to 16.2% after refinement,while the enhancement in strength remains marginal.
基金Hunan Provincial Department of Water Resources:Research on Formula Optimization and Performance Evaluation System of Ecological Concrete for River Water Quality Purification Based on the Dual Carbon Goal(Project No.:XSKJ2024064-44)。
文摘By adding zeolite aggregate with good adsorption properties,different mix ratios of added zeolite pervious concrete(ZPC)were designed to compare the water purification effect of ordinary pervious concrete and water purification tests that were conducted.The pore characteristics of the pervious concrete were identified using three-dimensional reconstruction software and the relationship between pore structure and water purification performance was quantified by gray entropy correlation analysis.The results showed that the purification efficiency of zeolite-doped pervious concrete was 17.6%-22.3%higher than that of ordinary pervious concrete.The characteristic parameters of the pore structure of permeable concrete,i.e.planar porosity and tortuosity,were determined using three-dimensional reconstruction software.The correlation between the degree of tortuosity and the removal rate reached more than 0.90,indicating that the internal pore structure of pervious concrete has a good correlation with the water purification performance.
基金Supported by Deep Purification Technology Project of Mixed Mode Wetland for Sewage Plant Waster Water in Dryland(2006AA6Z325)~~
文摘[Objective] The effect of baffled surface flow wetlands on water purification was studied in order to provide a reference for the ecological restoration of polluted river.[Method] Contents of some indexes like DO,TN,TP,NH＋4-N,CODCr,SS,SD,etc.were determined in the band baffled surface flow wetlands with total area of 7 400 m2 at JiaLu riverside.[Result] Baffled surface flow wetlands could improve the effluent quality significantly,could enhance transparency and dissolved oxygen content and also could decrease SS content.The removal rate of TN was kept at more than 73% in summer and decreased to 23% in early winter;The removal rate of TP was little influenced by temperature,and it was kept at more than 77% in summer and still kept at more than 69% in autumn and winter;The removal rate of NH＋4-N was kept at more than 83% in summer and decreased slightly in autumn and winter,but still kept at more than 75%;The removal rate of CODCr ranged from 14% to 50%.[Conclusion] Baffled surface flow wetlands could effectively improve the purification effect of surface flow wetlands,which is a feasible way for ecological restoration.
基金Supported by National Major Science and Technology Projects(2009ZX07317-006)National Major Science and Technology Projects(2009ZX07317-009)~~
文摘[Objective]The activities of urease and phosphatase in integrated vertical flow constructed wetland and purification effect of black and malodorous river were studied.[Method]Honeycomb stone and soft filler were used as matrix,the biological grid integrated vertical flow constructed wetland system was built to strengthen treatment for black and malodorous river,and the activities of urease and phosphatase of two fillers in different functional areas of constructed wetland were tested to study the film formation property of two fillers in different functional areas.[Result]Both urease and phosphatase activities on biofilm of soft filler were significantly higher than on biofilm of honeycomb stone filler;indicating that choosing soft filler was more advantageous to the growth of biofilm;and urease activity had significant correlation with total nitrogen removal rate,while phosphatase activity had no significant correlation with total phosphorus removal rate.[Conclusion]This study provided evidences for utilizing the activities of urease and phosphatase to evaluate the purification effect of black and malodorous river and choose appropriate filler.
基金Supported by the Social Development Project of Jiangsu Provincial Science and Technology Department(BK2010023)江苏省科技厅社会发展项目(BK2010023)资助
文摘[Objective] To study the purification effect of plant community on wetland water environment in Hongze Lake, and to provide references to the ecological restoration of this area. [Methed] The typical lakeside zone of Hongze Lake Wetland National Nature Reserve was taken as the study area. Through the field survey based on environmental characteristics of aquatic areas and non-aquatic areas, combined with laboratory test, the content changes of nutrients （N and P）, COD （chemical oxygen demand） and SD （transparency） levels in the water body of lake wetland were measured; the purification effect of the lake wetland ecosystem in the growth process of aquatic vegetation was quantitatively analyzed, and possible influ- encing factors were discussed. [Result] Aquatic vegetation could remove the TN, TP, COD, Chla in wetland water environment and had obvious effects on the changes of SD content. Competition between aquatic plants can inhibit the growth of algae and relieve the eutrophication of water body. [Conclusion] This study provided theoretical basis for ecological restoration and enhancement of self-purification capability in the lakeside zone of Hongze Lake.
基金Project(2007CB613700)supported by the National Basic Research Program of China
文摘Mg-Gd-Y-Zr alloys were purified by filtering purification with and without vacuum. The type, morphology, size distribution and volume fraction of inclusion were analyzed with OM and SEM. The effect of inclusion in Mg-Gd-Y-Zr alloys on anticorrosion ability was investigated with salt spray test and electrochemical test. The results show that the inclusions in the alloy can be removed effectively by filtering purification. The average size of inclusions in the alloys is decreased from 12.7 μm to 2.0 μm and the volume fraction of inclusions is reduced from 0.30% to 0.04%. With the decrease of the size of inclusions in the alloys, the corrosion rate of the alloys decreases dramatically from 38.8 g/（m 2 ·d） to 2.4 g/（m 2 ·d） in the salt spray test. The corrosion potential increases while the corrosion current decreases and the polarization resistance increases in the electrochemical tests, which indicates that the anticorrosion ability is improved.
基金Project(12511075)supported by the Foundation of Heilongjiang Education Committee,China
文摘To improve the poor stability of casting process of Al alloy with high Mg content, which leads to poor final product quality, the melting purification process and the influences of the refiner on the microstructure and defect of 5083 alloy were studied. The results show that the optimized process for the rotary impeller degassing of 5083 alloy is as follows： a rotary speed of 250-400 r/min; a gas flow of 1.2-2.0 L/s, a refining time of 10-15 min. This optimized process can reduce the gas content in the solid alloy to 2× 10^-3 mL/g or lower. Due to the addition of grain refiner, the cast microstructure of 5083 alloy is refined. The Al-5Ti-IB wire shows the best refining effect among all the refiners. The refining effect is improved with the increase of grain refiner addition amount. And the refinement effects become stable when Ti content reaches 0.1% or higher. The surface crinkling defect of the billet can be easily found in the alloy refined with Al-5Ti-IB wire compared with the alloys refined with other refiners.
基金Supported by National Key Basic Research Development Plan(973) Early Special Item(2008CB41720)Yunnan Application Basic Research Apparent Project (2009ZC083M)+1 种基金Yunnan Technological Plan Project (2008CA006)Apparent Fund Project of South West Forestry University (200804M)~~
文摘As the main external pollution source of lake,nitrogen and phosphorus from agricultural non-point source make a great contribution to the lake eutrophication pollution.Wetland lakefront zone which plays a key role in externally agricultural non-point source pollution is considered as the biggest barrier for controlling external pollution.In this research,the Jian lake plateau Zizania latifolia wetland lakefront zone was selected for agricultural non-point source pollutions control with the systematic field research,and the lakefront zone was approved to have an effective purification effect on nitrogen and phosphorus from Jinlong River; the theoretical mechanism of lakefront zone removing nutrient was also investigated.Z.latifolia wetland lakefront zone could remove nitrogen and phosphorus from Jinlong River and the removal ratio can reach 55.8-62.52% and 59.47-69.81% respectively.So,we can indicate that the Jian Lake plateau Z.latifolia wetland lakefront zone had a good effect on controlling agricultural non-point source pollution and protecting the environment.
基金supported by the National Natural Science Foundation of China (No. 21007050)the Changjiang Scholars and Innovative Research Team in University (PC-SIRT) (No. IRT0853)the Natural Science Foundation of Shaanxi (No. 2009JQ7001)
文摘Due to the formation of disinfection by-products and high concentrations of Al residue in drinking water purification, humic substances are a major component of organic matter in natural waters and have therefore received a great deal of attention in recent years. We investigated the effects of advanced oxidation pretreatment methods usually applied for removing dissolved organic matters on residual Al control. Results showed that the presence of humic acid increased residual Al concentration notably. With 15 mg/L of humic acid in raw water, the concentrations of soluble aluminum and total aluminum in the treated water were close to the quantity of Al addition. After increasing coagulant dosage from 12 to 120 mg/L, the total-Al in the treated water was controlled to below 0.2 mg/L. Purification systems with ozonation, chlorination, or potassium permanganate oxidation pretreatment units had little effects on residual Al control; while UV radiation decreased Al concentration notably. Combined with ozonation, the effects of UV radiation were enhanced. Optimal dosages were 0.5 mg O 3 /mg C and 3 hr for raw water with 15 mg/L of humic acid. Under UV light radiation, the combined forces or bonds that existed among humic acid molecules were destroyed; adsorption sites increased positively with radiation time, which promoted adsorption of humic acid onto polymeric aluminum and Al（OH） 3 （s）. This work provides a new solution for humic acid coagulation and residual Al control for raw water with humic acid purification.
基金Project supported by the National Natural Science Foundation of China(21643008)
文摘Hydrogen purification must be done to meet the different purposes of hydrogen utilization.In the present work,it is confirmed that the catalyst Ni/CeO2 has the highest activity for total methanation(Total MET) of CO and CO2,and is thus most suitable for hydrogen purification for ammonia synthesis.While,the catalyst Ni/ZrO2 appears the best one for selective methanation of CO(CO-SMET) in the H2-rich gas to produce clean fuel for proton exchange membrane fuel cell(PEMFC).In spite of this,the catalyst Ni/ZrO2 without adding chlorine ions as promoter is not yet capable of removing the CO in the reformate gas to below 10 ppm in a wide reaction temperature range by the way of CO-SMET.Adding chlorine ions as promoter is indeed not favorable for practical application due to its gradual loss in the catalytic reaction as proved in our previous work.Therefore,a step to decrease CO2 concentration(called as de-CO2 step) is suggested to be set prior to the CO-SMET step in this work.It is proved that such combination of de-CO2 step and CO-SMET step is efficient to achieve a deep removal of CO to below 10 ppm with a high selectivity more than 50% in a wide reaction temperature range of 220-280℃over the catalyst Ni/ZrO2 without adding chlorine ions as promoter.The combined process has potential for practical application,at least in the large-scale power plant of PEMFC.
文摘AIM To extract and purify the transforming growth factor β (TGF β), and to demonstrate its biological activity in vivo and induction of apoptosis of hepatocytes in vitro.METHODS TGF β was isolated from fresh bovine platelets by acid/ethanol extraction method and purified with ion exchange and gel chromatography. The extracted TGF β was injected subcutaneously to mice, and its biological activity in vivo was observed 72 hfs post-injection by HE staining. The morphological changes were observed by HE staining and the occurrence of apoptosis was detected by TUNEL method after the human normal hepatic cell line QZG was treated with 8 μg@L 1 TGFβ for 12 hrs in vitro.RESULTS The molecular mass 25 ku TGF β protein was successfully extracted. It was able to induce localized granulation tissue formation in vivo. TGF β-treated hepatocytes showed obvious apoptotic morphological changes, including the pyknosis and dense-stained nuclei and cytoplasm, the fragmentary, annular or crescent nuclei, and the "bubbling" cytoplasm. Moreover, its apoptotic rate was significantly higher than that of the control group (P＜0.05).CONCLUSION Biological active TGF β protein is extracted and purified successfully from bovine platelets, and it is able to induce the apoptosis of hepatocytes.
基金National Technology Graveness Special Purpose Fund(Grant No.2009ZX09301-010)
文摘Recombinant ancylostoma caninum anticoagulant peptide-5 （rAcAP5） has been reported to inhibit thrombin-activatable fibrinolysis inhibitor （TAFIa） activity and have thrombolytic effect. The present study was to screen a strain expressing high-yield of rAcAP5 and to assess its thrombolytic effect on embolic middle cerebral artery occlusion （MCAO） model in rats. Codons encoding for AcAP5 were optimized. Six expression plasmids and eleven E. coli strains with different characteristics were used, a total of 66 recombinant expression strains were generated and the one with the highest yield was selected to express rAcAP5, which was purified through anion- and cation-exchange chromatography. The purity of rAcAP5 and its molecular weight were determined by HPLC and mass spectrometry, respectively. The thrombolytic effect of rAcAP5 was evaluated on embolic MCAO model in rats; regional cerebral blood flow （rCBF） was monitored with a Laser-Doppler flowmetry to test the occlusion and recanalization of MCA. The highest yield recombinant strain was C2566H/pTYB 1-rAcAP5. AcAP5 （28 mg） with 90% of purity was obtained from 1 L of cell culture. In rat embolic MCAO model, vehicle （normal saline） treatment did not change the rCBF, while treatment with rAcAP5 （50-200 μg/kg, i.v.） increased the rCBF in a dose-dependent manner. In conclusion, we prepared and characterized the rAcAP5 peptide and revealed its thrombolytic effect in embolic MCAO model and our results suggested that this peptide had the potential to be used as a thrombolytic agent.
基金Supported by Science and Technology Planning Project of Higher Education of Shandong Province(J16LE05)
文摘Phycoerythrin, as the main light-harvesting antenna in Porphyridium purpureum, exists at the outermost end of the phycobilisome. It has advantages of good fluorescence intensity, anti-oxidation, scavenging free radicals, and high chroma, so it has been widely used in food, cosmetics, pharmaceuticals, and other industries. In this study, the effects of different extraction(ultrasonic breaking method, bead grinding method, liquid nitrogen grinding method, and freezing-thawing method) and purification methods(salting out method, ultrafiltration method, and combination of salting out and ultrafiltration method) on the acquisition of phycoerythrin from P. purpureum were studied, and the characteristics of phycoerythrin in the P. purpureum were identified. The results showed that the freezing-thawing method could extract phycoerythrin from the powder of P. purpureum to the utmost extent, and the concentration of the extracted phycoerythrin was up to 0.036 g/L. The salting out method could most effectively purify phycoerythrin, and the purity index was 2.216. The identification of phycoerythrin by ultraviolet absorption spectroscopy and fluorescence spectroscopy indicated that the phycoerythrin had the maximum absorption peak at 545 nm, and the maximum Stokes shift was up to 79 nm. Due to its high fluorescence characteristics, it can be used as a fluorescent marker in the fields of molecular biology and clinical medicine, and can also be used as a good photosensitizer in tumor therapy.
基金Project(2007CB613705)supported by the National Basic Research Program of China
文摘Mg-Gd-Y-Zr alloy was purified by the method of filtering purification. The type, morphology, size distribution and volume fraction of inclusions in the alloy were analyzed using optical microscope and scanning electron microscope, and the effects of the inclusions on the mechanical and corrosion properties of the alloy were investigated. The results indicate that the filtering purification method is effective to remove inclusions in the alloy. By the filtering purification method, the average size of inclusions in the alloy reduces from 12.7 μm to 4.3 μm and the average volume fraction of inclusions in the alloy reduces from 0.26% to 0.06%. The ultimate tensile strength, yield strength and elongation of the alloy are improved from 200 MPa, 156 MPa and 3.4% to 232 MPa, 167 MPa and 7.0%, respectively. The corrosion rate of the alloy decreases dramatically from 38.8g/（mLd） to 2.5 g/（mZ.d） in the salt spray test.
基金Project(2007CB613705)supported by the National Basic Research Program of China
文摘The effects of trace element Fe on the corrosion behavior of AZ80 magnesium alloy were investigated by salt spray test and electrochemical measurements.The results show that the corrosion rate decreases with decreasing the trace element Fe content in an approximately linear relation even though the amount of trace element Fe reduces to 0.000 2%(mass fraction).The electrochemical measurements show that the corrosion potential(φcorr)of the alloy with lower trace element Fe content shifts to less negative value.It is suggested that the control trace element by purification is an effective way to enhance the corrosion resistance of AZ80 magnesium alloy.
基金financially supported by the Special Project on the Integration of Industry, Education and Research of Guangdong Province, China (No. 20013A090100013)by the High Technology Research and Development Program of Xinjiang Uygur Autonomous Region of China (No. 201407300993)
文摘The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.
基金the Science and Technology Project of Xiamen Medical College(K2016-36).
文摘A water-soluble polysaccharide,designated BFP-3,was isolated from Bangia fuscopurpurea by hot water extraction,anion-exchange,and size-exclusion chromatography and tested to determine its antitumor activity.The structural characteristics of BFP-3 were investigated by chemical and spectroscopic methods,including partial acid hydrolysis,methylation analysis,one-and two-dimensional nuclear magnetic resonance,and gas chromatography-mass spectrometry.The results showed that BFP-3 was mainly comprised of rhamnose,arabinose,mannose,glucose,and galactose.Moreover,the weight-average molecular weight of BFP-3 was estimated to be approximately 333 kDa.The backbone of BFP-3 was primarily composed of repeating 5-α-l-Araf-1→(4-α-d-Glcp-1)_(4)→4,6-β-d-Manp-1 units,and the side chains consisted of repeatingβ-d-Galp-1→(4-β-d-Galp-1)_(4)→4,6-β-d-Galp-1→3,4-α-l-Rhap,β-l-Arap-1→(3-β-d-Galp-1)_(3),andβ-l-Arap-1 units.Counting Kit-8 assays revealed that BFP-3 significantly inhibited the proliferation of A2780,COC1,SKOV3,HO-8910,and OVCAR3 ovarian cancer cells in vitro,indicating that BFP-3 could have potential applications in the treatment of ovarian cancer.
基金Supported by the Project of Public Welfare Application Research from Huzhou Science and Technology Bureau(2013C102070)
文摘A synthetic biological pond composed of aquatic plants, a microorganism and aquatic animals was applied in the purification of the wastewater discharged from a Tnonyx sinensis breeding greenhouse, and the removal effects of TN, NH4＋ -N, TP and COD in the wastewater were analyzed. The results show that after the breeding wastewater was purified by the synthetic biological pond for about five months, TN, NH~ -N, TP and COD concentration in the breeding wastewater were reduced by 78%, 92%, 81% and 60% respectively, while DO content in the breeding wastewater increased by about four times, and there was no obvious change in water pH; previous yellow or brown and turbid sewage became yel- lowish and slightly turbid, and it had no smell. It is obviously seen that the purification effect of T. sinensis breeding wastewater by the synthetic biological pond composed of aquatic plants, a microorganism and aquatic animals is obvious, and the synthetic biological pond has good promotion and application prospects.
基金the Natural Science Foundation of Education Department of Jiangsu Province (No.05KJB430102)the Natural Science Foundation of Nantong University(Nos.11ZY007 and 11C001)
文摘The effects of several fluxes on purification,microstructures and properties of A00 aluminum have been studied.The experimental results and analyses indicate that many cracks and large porosities exist in the surface film above the melt purified by C2Cl6 and that the film is floc and mostly composed of Al 2 O 3 and pure aluminum,which carries many carbon particles and AlCl 3 not fully volatilized.And then over 50%(mass fraction) of the all-melting residue is pure aluminum,which is one of the major reasons for high melting loss.Moreover,because of a mass of gas bubbles and a state of seethe,there are many inclusions which size is under 10 μ m in the microstructure of A00 aluminum purified with C2Cl6 or fluxes containing C2Cl6.With this purifying method,the aluminum crystal grains are extended along the radius that was observed firstly and the average crystal size of A00 aluminum are about 100-150 μ m.In addition,small size inclusions have little affected on tensile strength and micro inclusions under 10 μ m have little affected on elongation.
