Based on the analysis of rice planting and export development in Heilongjiang Province in 2013-2021,this paper comprehensively used three export competitiveness analysis methods,namely,trade competitiveness index,reve...Based on the analysis of rice planting and export development in Heilongjiang Province in 2013-2021,this paper comprehensively used three export competitiveness analysis methods,namely,trade competitiveness index,revealed comparative advantage(RCA)analysis and international market share analysis,to compare the four major rice exporters in the world and the three major rice export provinces and cities in China.Besides,it evaluated the rice export competitiveness of Heilongjiang Province from multiple perspectives.It analyzed the reasons for low competitiveness in terms of export product structure,export market structure,production and processing technology,and brand building.Finally,it is recommended to clarify the positioning of rice export quality and take more measures to ensure product quality;improve the level of industrialization of rice production and processing,and extend the rice industry chain;develop diversified rice export markets and improve export flexibility;adhere to the principle of"opening the door and going out",expand the international popularity of high-quality brands,so as to enhance the rice export competitiveness of Heilongjiang Province.展开更多
Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma.However,the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less s...Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma.However,the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less studied.Sesquiterpenoids were significantly accumulated in a previously reported glossy mutant of orange(MT)than the wild type(WT),especially valencene and caryophyllene.In addition,we identified several other pathways with variations at both the transcriptional and metabolic levels in MT.It’s interesting to found those upregulated metabolites in MT,such as eukaryotic lipids,kaempferol and proline also showed strong positive correlation with valencene along with fruit maturation while those down-regulated metabolites,such as phenylpropanoid coumarins and most of the modified flavonoids exhibited negative correlation.We then categorized these shifted pathways into the‘sesquitepenoid-identical shunt’and the sesquitepenoid-opposite shunt’and confirmed the classification result at transcriptional level.Our results provide important insights into the connections between various fruit quality-related properties.展开更多
The selective elimination of radioactive cesium from complicated wastewater is imperative in view of environment and human health.Montmorillonite has been accepted as one of the most promising adsorbents for cesium pu...The selective elimination of radioactive cesium from complicated wastewater is imperative in view of environment and human health.Montmorillonite has been accepted as one of the most promising adsorbents for cesium purification.However,its poor selectivity still remains a major challenge.Herein,a novel montmorillonite-sulfur composite was developed via a facile one-step solvent-free method and used for Cs^(+) removal.Owing to the fact that soft Lewis base S^(2-) ligand interacted more strongly with softer Lewis acid Cs^(+) than other cations,the capacity and selectivity towards Cs^(+) was significantly enhanced.In this case,a large capacity of 160.9 mg g^(-1) was achieved.The distribution coefficient value(~4000 mL g^(-1))was 3-times larger than that of pristine montmorillonite(~1500 mL g^(-1)).Moreover,this composite could be easily recycled and reused within five times recycling experiments.Therefore,this low-cost and facilely prepared composite are expected to be used for the selective removal of Cs^(+) from complicated wastewater containing various competing ions.展开更多
Objective： We previously found that hUTP14a binds P53 and promotes P53 degradation. However, if hUTP14a is a downstream gene of P53 remains to be determined. This study aimed to identify the promoter of h UTP14a and ...Objective： We previously found that hUTP14a binds P53 and promotes P53 degradation. However, if hUTP14a is a downstream gene of P53 remains to be determined. This study aimed to identify the promoter of h UTP14a and investigate if h UTP14a is regulated by P53. Methods： The hUTPI4a promoter region was cloned into pGL3-Basic-luciferase reporter plasmid to get pGL3-hUTP14a-luc. The reporter plasmid was transfected into 293T cells and luciferase activity was evaluated by the Dual-Luciferase Reporter Assay System. Putative transcription factors were identified through searching Matlnspector Professional and Algorismica i Genetica databases. Either pGL3-hUTPI4aluc or p21 promoter reporter plasmid was co-transfected with increasing dose of p53 plasmid, and luciferase activity was evaluated. A series of deletion constructs of pGL3-hUTP14a-luc were constructed and minimal promoter region of hUTP14a was determined. Differences of the lnciferase activities between different groups were assessed by statistical analysis. Results： The hUTP14a gene promoter reporter construct was correctly cloned and was demonstrated to possess promoter activity. The transcription of hUTP14a was not regulated by P53. The minimal promoter region of h UTP14a gene is located between -203 to -100 of the transcription initiation site. Conclusion： Unlike other P53-interacting proteins such as MDM2, Pirh2 and Cop I which promote P53 degradation and whose transcriptions are regulated by P53, does not hUTP14a transcription form a regulation feedback loop with P 53.展开更多
Radioisotope leaking from nuclear waste has become an intractable problem due to its gamma radiation and strong water solubility.In this work,a novel porous ZnFC-PA/PSF composite sphere was fabricated by immobilizatio...Radioisotope leaking from nuclear waste has become an intractable problem due to its gamma radiation and strong water solubility.In this work,a novel porous ZnFC-PA/PSF composite sphere was fabricated by immobilization of ferrocyanides modified zinc phytate into polysulfone(PSF)substrate for the treatment of Cs-contaminated water.The maximum adsorption capacity of ZnFC-PA/PSF was 305.38 mg/g,and the removal efficiency of Cs+was reached 94.27%within 2 hr.The ZnFC-PA/PSF presented favorable stability with negligible dissolution loss of Zn^(2+)and Fe^(2+)(<2%).The ZnFC-PA/PSF achieved high-selectivity towards Cs+(K_(d)=2.24×10^(4)mL/g)even in actual geothermal water.The adsorption mechanism was inferred to be the ion-exchange between Cs^(+)and K^(+).What’s more,ZnFC-PA/PSF worked well in the fixed-bed adsorption(E=91.92%),indicating the application potential for the hazardous Cs^(+)removal from wastewater.展开更多
What is already known about this topic?An association between prenatal heatwave exposure and the risk of preterm birth was found.However,the disparities in heatwave-related preterm birth across different climate types...What is already known about this topic?An association between prenatal heatwave exposure and the risk of preterm birth was found.However,the disparities in heatwave-related preterm birth across different climate types have not been examined.What is added by this report?This nationwide case-crossover study investigated the association between heatwave exposure and preterm birth across different Köppen-Geiger climate types.Among pregnant women residing in the arid-desertcold climate type,exposure to compound heatwaves was found to be associated with a significantly higher risk of preterm birth{adjusted odds ratios(AORs)ranged from 1.55[95%confidence interval(CI):1.21-1.97]to 2.11(95%CI:1.35-3.31)}.In contrast,among pregnant women residing in the tropical monsoonal climate type,exposure to daytime-only heatwaves was associated with an increased risk of preterm birth[AORs ranged from 1.25(95%CI:1.03-1.51)to 1.37(95%CI:1.05-1.77)].展开更多
Metastasis is a major cause of colorectal cancer(CRC)mortality,but its molecular mechanisms are still not fully understood.Here,we show that upregulated DDX39B correlates with liver metastases and aggressive phenotype...Metastasis is a major cause of colorectal cancer(CRC)mortality,but its molecular mechanisms are still not fully understood.Here,we show that upregulated DDX39B correlates with liver metastases and aggressive phenotypes in CRC.DDX39B is an independent prognostic factor associated with poor clinical outcome in CRC patients.We demonstrate that Sp1 potently activates DDX39B transcription by directly binding to the GC box of the DDX39B promoter in CRC cells.DDX39B overexpression augments the proliferation,migration,and invasion of CRC cells,while the opposite results are obtained in DDX39B-deficient CRC cells.Mechanistically,DDX39B interacts directly with and stabilizes PKM2 by competitively suppressing STUB1-mediated PKM2 ubiquitination and degradation.Importantly,DDX39B recruits importin a5 to accelerate the nuclear translocation of PKM2 independent of ERK1/2-mediated phosphorylation of PKM2,leading to the transactivation of oncogenes and glycolysis-related genes.Consequently,DDX39B enhances glucose uptake and lactate production to activate Warburg effect in CRC.We identify that Arg319 of DDX39B is required for PKM2 binding as well as PKM2 nuclear accumulation and for DDX39B to promote CRC growth and metastasis.In addition,blocking PKM2 nuclear translocation or treatment with glycolytic inhibitor 2-deoxy-D-glucose efficiently abolishes DDX39B-triggered malignant development in CRC.Taken together,ourfindings uncover akey role forDDX39B in modulating glycolytic reprogramming and aggressive progression,and implicate DDX39B as a potential therapeutic target in CRC.展开更多
An inclusion complex of podophyllotoxin （PPT） with 7-cyclodextrin （7-CD） was prepared. The behavior, char- acterization, and water solubility of the inclusion complex were carefully investigated via fluorescence s...An inclusion complex of podophyllotoxin （PPT） with 7-cyclodextrin （7-CD） was prepared. The behavior, char- acterization, and water solubility of the inclusion complex were carefully investigated via fluorescence spectroscopy, thermogravimetry, differential scanning calorimetry, X-ray diffraction analysis, and 1H and 2D nuclear magnetic resonance spectroscopy. Furthermore, antitumor activity to human cancer lines and toxicity in mice were studied. Results showed that the inclusion complex formed in a 1 ： 1 ratio with a considerable apparent stability constant Ks （4245.5 Lomol-l）. Water solubility was considerably improved. In addition, the anticancer activity of the inclusion complex was better than that of cis-platinum （DDP, positive control）. Most importantly, the toxicity of podophyl- lotoxin inclusion complex reduced and became more safety to mice which will be great valuable to research its ap- plications as a kind of antitumor drug to human in the further.展开更多
The solubilities and densities of the aqueous metastable ternary systems(NaCl-MgCl_(2)-H_(2)O)and(KCl-MgCl_(2)-H_(2)O)at 308.15 K were determined by the isothermal evaporation method.On the basis of the experimental r...The solubilities and densities of the aqueous metastable ternary systems(NaCl-MgCl_(2)-H_(2)O)and(KCl-MgCl_(2)-H_(2)O)at 308.15 K were determined by the isothermal evaporation method.On the basis of the experimental results,the phase diagrams for those systems were plotted.It was found that the former system belongs to the hydrate-I type with one invariant point of(NaCl+MgCl_(2)·6H_(2)O),two univariant curves,and two crystal-lization regions corresponding to halite(NaCl)and bischofite(MgCl_(2)·6H_(2)O);and the latter system belongs to the type of incongruent-double salts with two invariant points of(KCl+KCl·MgCl_(2)·6H_(2)O)and(MgCl_(2)·6H_(2)O+KCl·MgCl_(2)·6H_(2)O),three univariant curves,and three crystallization regions corresponding to potassium chlor-ide(KCl),carnallite(KCl·MgCl_(2)·6H_(2)O)and bischofite(MgCl_(2)·6H_(2).No solid solutions were found in both systems.展开更多
This research was conducted to investigate the biooxidation and copper dissolution from raw low-grade refractory copper sulphide ores located in the Xinjiang Autonomous Region of China using adapted Thiobacillus ferro...This research was conducted to investigate the biooxidation and copper dissolution from raw low-grade refractory copper sulphide ores located in the Xinjiang Autonomous Region of China using adapted Thiobacillus ferrooxidans bacteria.In order to accelerate the bioleach-ing rate,the adapted mixed bacteria and silver ion catalyst were tested in the leach columns at laboratory scale.The overall acid consumption was 4.3kg sulphuric acid per kg of dissolved copper and was linearly related to the percent copper dissolution.The calculated copper dissolution rates obey the Shrinking Core Model.The relative activation energy of the whole biooxidative leaching stages was calculated to be 48.58kJ/mol.展开更多
Zangnan Salt Lake on the south of the Tibet is a type of carbonate lake with high concentrations of lithium,boron,and potassium and obviously it differs from seawater in its chemical composition.An experimental simula...Zangnan Salt Lake on the south of the Tibet is a type of carbonate lake with high concentrations of lithium,boron,and potassium and obviously it differs from seawater in its chemical composition.An experimental simulation of the caloric evaporation of the lake’s brine was conducted byfirst freezing the brine and then performing isothermal evaporation at 288.15 K.The freezing path and the physicochemical properties of the brine were determined.The crystallization sequence was natron,hydrohalite,halite,sylvite,zabuyelite,trona,aphthitalite,thermonatrite,and borax.Rubidium and cesium salts did not crystallized out but concentrated in the mother solution.The physicochemical properties(density,refractive index,conductivity,and pH)of the liquid phase changed as the evaporation progressed.In the beginning of the evaporation processes,the concentration of potassium ions in the liquid phase gradually increased but later it decreased.A peak value of 55.21 g/L was obtained when the evaporation was 88%complete.When the mineral aphthitalite began to crystallize;the concentra-tions of B2O3,Li+,Rb+,and Cs+gradually increased as the evaporation progressed.When the evaporation was 98%complete,their concentrations in the mother liquor were 40.77 g/L,4.838 g/L,400.17 mg/L and 31.95 mg/L,respectively.This essential fundamental study can provide an important reference for the comprehensive utilization of brines in Zangnan Salt Lake.展开更多
基金Social Science Planning Project of Xi an City(JG140)Bidding Project of Buchang Xixian Economic Research Institute(SMZX202113).
文摘Based on the analysis of rice planting and export development in Heilongjiang Province in 2013-2021,this paper comprehensively used three export competitiveness analysis methods,namely,trade competitiveness index,revealed comparative advantage(RCA)analysis and international market share analysis,to compare the four major rice exporters in the world and the three major rice export provinces and cities in China.Besides,it evaluated the rice export competitiveness of Heilongjiang Province from multiple perspectives.It analyzed the reasons for low competitiveness in terms of export product structure,export market structure,production and processing technology,and brand building.Finally,it is recommended to clarify the positioning of rice export quality and take more measures to ensure product quality;improve the level of industrialization of rice production and processing,and extend the rice industry chain;develop diversified rice export markets and improve export flexibility;adhere to the principle of"opening the door and going out",expand the international popularity of high-quality brands,so as to enhance the rice export competitiveness of Heilongjiang Province.
基金financed by the National Natural Science Foundation of China (31772261)the Huazhong Agricultural University Scientific & Technological Self-Innovation Foundation (Program No.2017RC002) to Dr. Weiwei Wen
文摘Sesquiterpene valencene is dominant in flavedo tissues of sweet oranges and imparts a unique woody aroma.However,the interaction between the biosynthetic pathways of valencene and other nutritional compounds is less studied.Sesquiterpenoids were significantly accumulated in a previously reported glossy mutant of orange(MT)than the wild type(WT),especially valencene and caryophyllene.In addition,we identified several other pathways with variations at both the transcriptional and metabolic levels in MT.It’s interesting to found those upregulated metabolites in MT,such as eukaryotic lipids,kaempferol and proline also showed strong positive correlation with valencene along with fruit maturation while those down-regulated metabolites,such as phenylpropanoid coumarins and most of the modified flavonoids exhibited negative correlation.We then categorized these shifted pathways into the‘sesquitepenoid-identical shunt’and the sesquitepenoid-opposite shunt’and confirmed the classification result at transcriptional level.Our results provide important insights into the connections between various fruit quality-related properties.
基金partial financial supports from the National Natural Science Foundation of China(21901183 and 21773170)Innovation Project of Excellent Doctorial Dissertation of Tianjin University of Science and Technology(201909)+2 种基金National Undergraduate Innovation and Entrepreneurship Training Project(201910057101)the Major Special Project of Tibet Autonomous Region(XZ201801-GB01)the Yangtze Scholars and Innovative Research Team of the Chinese University(IRT_17R81)。
文摘The selective elimination of radioactive cesium from complicated wastewater is imperative in view of environment and human health.Montmorillonite has been accepted as one of the most promising adsorbents for cesium purification.However,its poor selectivity still remains a major challenge.Herein,a novel montmorillonite-sulfur composite was developed via a facile one-step solvent-free method and used for Cs^(+) removal.Owing to the fact that soft Lewis base S^(2-) ligand interacted more strongly with softer Lewis acid Cs^(+) than other cations,the capacity and selectivity towards Cs^(+) was significantly enhanced.In this case,a large capacity of 160.9 mg g^(-1) was achieved.The distribution coefficient value(~4000 mL g^(-1))was 3-times larger than that of pristine montmorillonite(~1500 mL g^(-1)).Moreover,this composite could be easily recycled and reused within five times recycling experiments.Therefore,this low-cost and facilely prepared composite are expected to be used for the selective removal of Cs^(+) from complicated wastewater containing various competing ions.
基金supported by grants from Beijing Municipal Natural Science Foundation (Grant No. 7122032)the National Natural Science Foundation of China (Grant No. 81071672)+1 种基金the National Basic Research Program of China (973 program) (Grant No. 2010CB529303)National High Technology Research and Development Program of China (863 Program, Grant No. 2008AA02Z131)
文摘Objective： We previously found that hUTP14a binds P53 and promotes P53 degradation. However, if hUTP14a is a downstream gene of P53 remains to be determined. This study aimed to identify the promoter of h UTP14a and investigate if h UTP14a is regulated by P53. Methods： The hUTPI4a promoter region was cloned into pGL3-Basic-luciferase reporter plasmid to get pGL3-hUTP14a-luc. The reporter plasmid was transfected into 293T cells and luciferase activity was evaluated by the Dual-Luciferase Reporter Assay System. Putative transcription factors were identified through searching Matlnspector Professional and Algorismica i Genetica databases. Either pGL3-hUTPI4aluc or p21 promoter reporter plasmid was co-transfected with increasing dose of p53 plasmid, and luciferase activity was evaluated. A series of deletion constructs of pGL3-hUTP14a-luc were constructed and minimal promoter region of hUTP14a was determined. Differences of the lnciferase activities between different groups were assessed by statistical analysis. Results： The hUTP14a gene promoter reporter construct was correctly cloned and was demonstrated to possess promoter activity. The transcription of hUTP14a was not regulated by P53. The minimal promoter region of h UTP14a gene is located between -203 to -100 of the transcription initiation site. Conclusion： Unlike other P53-interacting proteins such as MDM2, Pirh2 and Cop I which promote P53 degradation and whose transcriptions are regulated by P53, does not hUTP14a transcription form a regulation feedback loop with P 53.
基金supported by the National Natural Science Foundation of China(Nos.22203062,22078247,U1707602,U1507109)the Yangtze Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT17R81)。
文摘Radioisotope leaking from nuclear waste has become an intractable problem due to its gamma radiation and strong water solubility.In this work,a novel porous ZnFC-PA/PSF composite sphere was fabricated by immobilization of ferrocyanides modified zinc phytate into polysulfone(PSF)substrate for the treatment of Cs-contaminated water.The maximum adsorption capacity of ZnFC-PA/PSF was 305.38 mg/g,and the removal efficiency of Cs+was reached 94.27%within 2 hr.The ZnFC-PA/PSF presented favorable stability with negligible dissolution loss of Zn^(2+)and Fe^(2+)(<2%).The ZnFC-PA/PSF achieved high-selectivity towards Cs+(K_(d)=2.24×10^(4)mL/g)even in actual geothermal water.The adsorption mechanism was inferred to be the ion-exchange between Cs^(+)and K^(+).What’s more,ZnFC-PA/PSF worked well in the fixed-bed adsorption(E=91.92%),indicating the application potential for the hazardous Cs^(+)removal from wastewater.
基金Project on Mechanism-Based Precise and Integrated Strategies for Preventing and Managing Preterm Birth(2022YFC2704600,2022YFC2704605)funded by The National Key Research and Development Program of China.Public Health Issues Arising from Climate Change(grant 202046)+1 种基金funded by the Chinese Ministry of Ecology and Environment.Project on the Establishment of China-ASEAN Science and Technology Cooperation Center for Public Health(KY202101004)funded by The National Key Research and Development Program of China.
文摘What is already known about this topic?An association between prenatal heatwave exposure and the risk of preterm birth was found.However,the disparities in heatwave-related preterm birth across different climate types have not been examined.What is added by this report?This nationwide case-crossover study investigated the association between heatwave exposure and preterm birth across different Köppen-Geiger climate types.Among pregnant women residing in the arid-desertcold climate type,exposure to compound heatwaves was found to be associated with a significantly higher risk of preterm birth{adjusted odds ratios(AORs)ranged from 1.55[95%confidence interval(CI):1.21-1.97]to 2.11(95%CI:1.35-3.31)}.In contrast,among pregnant women residing in the tropical monsoonal climate type,exposure to daytime-only heatwaves was associated with an increased risk of preterm birth[AORs ranged from 1.25(95%CI:1.03-1.51)to 1.37(95%CI:1.05-1.77)].
基金This work was supported by the National Natural Science Foundation of China(81874071,81773756,82103525,and 82072933)1.3.5 project for disciplines of ecellence-Clinical Research Incubation Project,West China Hospital,Sichuan University(2020HXFH007)Post-Doctor Research Project,West China Hospital,Sichuan University(2020HXBH036).
文摘Metastasis is a major cause of colorectal cancer(CRC)mortality,but its molecular mechanisms are still not fully understood.Here,we show that upregulated DDX39B correlates with liver metastases and aggressive phenotypes in CRC.DDX39B is an independent prognostic factor associated with poor clinical outcome in CRC patients.We demonstrate that Sp1 potently activates DDX39B transcription by directly binding to the GC box of the DDX39B promoter in CRC cells.DDX39B overexpression augments the proliferation,migration,and invasion of CRC cells,while the opposite results are obtained in DDX39B-deficient CRC cells.Mechanistically,DDX39B interacts directly with and stabilizes PKM2 by competitively suppressing STUB1-mediated PKM2 ubiquitination and degradation.Importantly,DDX39B recruits importin a5 to accelerate the nuclear translocation of PKM2 independent of ERK1/2-mediated phosphorylation of PKM2,leading to the transactivation of oncogenes and glycolysis-related genes.Consequently,DDX39B enhances glucose uptake and lactate production to activate Warburg effect in CRC.We identify that Arg319 of DDX39B is required for PKM2 binding as well as PKM2 nuclear accumulation and for DDX39B to promote CRC growth and metastasis.In addition,blocking PKM2 nuclear translocation or treatment with glycolytic inhibitor 2-deoxy-D-glucose efficiently abolishes DDX39B-triggered malignant development in CRC.Taken together,ourfindings uncover akey role forDDX39B in modulating glycolytic reprogramming and aggressive progression,and implicate DDX39B as a potential therapeutic target in CRC.
基金supported by the National Natural Science Foundation of China(41761043,41201196,41261047)the Youth Teacher Scientific Capability Promoting Project of Northwest Normal University(NWNU-LKQN2020-06,NWNU-LKQN-17-7)the Key Research and Development Program of Gansu Province(20YF3FA042).
文摘An inclusion complex of podophyllotoxin （PPT） with 7-cyclodextrin （7-CD） was prepared. The behavior, char- acterization, and water solubility of the inclusion complex were carefully investigated via fluorescence spectroscopy, thermogravimetry, differential scanning calorimetry, X-ray diffraction analysis, and 1H and 2D nuclear magnetic resonance spectroscopy. Furthermore, antitumor activity to human cancer lines and toxicity in mice were studied. Results showed that the inclusion complex formed in a 1 ： 1 ratio with a considerable apparent stability constant Ks （4245.5 Lomol-l）. Water solubility was considerably improved. In addition, the anticancer activity of the inclusion complex was better than that of cis-platinum （DDP, positive control）. Most importantly, the toxicity of podophyl- lotoxin inclusion complex reduced and became more safety to mice which will be great valuable to research its ap- plications as a kind of antitumor drug to human in the further.
基金Financial support from the State Key Program of National Natural Science of China(No.20836009)the National Natural Science Foundation of China(Grant Nos.40573044,40773045)+1 种基金the“A Hundred Talents Program”of the Chinese Academy of Sciences(No.0560051057)the Specialized Research Fund for the Doctoral Program of Chinese Higher Education(No.20060616004)is greatly acknowledged.
文摘The solubilities and densities of the aqueous metastable ternary systems(NaCl-MgCl_(2)-H_(2)O)and(KCl-MgCl_(2)-H_(2)O)at 308.15 K were determined by the isothermal evaporation method.On the basis of the experimental results,the phase diagrams for those systems were plotted.It was found that the former system belongs to the hydrate-I type with one invariant point of(NaCl+MgCl_(2)·6H_(2)O),two univariant curves,and two crystal-lization regions corresponding to halite(NaCl)and bischofite(MgCl_(2)·6H_(2)O);and the latter system belongs to the type of incongruent-double salts with two invariant points of(KCl+KCl·MgCl_(2)·6H_(2)O)and(MgCl_(2)·6H_(2)O+KCl·MgCl_(2)·6H_(2)O),three univariant curves,and three crystallization regions corresponding to potassium chlor-ide(KCl),carnallite(KCl·MgCl_(2)·6H_(2)O)and bischofite(MgCl_(2)·6H_(2).No solid solutions were found in both systems.
基金Financial contributions from the National Natural Science Foundation of China(Grant Nos.20776019 and 40573044)the“A Hundred Talents Program”of the Chinese Academy of Sciences(No.0560051057)+1 种基金the Key Program of Department of Education of Sichuan Government(No.2004A146)the Applied Basic Research Program of Sichuan Government(Nos.05JY029-089-1,05JY029-089-2)are acknowl-edged.
文摘This research was conducted to investigate the biooxidation and copper dissolution from raw low-grade refractory copper sulphide ores located in the Xinjiang Autonomous Region of China using adapted Thiobacillus ferrooxidans bacteria.In order to accelerate the bioleach-ing rate,the adapted mixed bacteria and silver ion catalyst were tested in the leach columns at laboratory scale.The overall acid consumption was 4.3kg sulphuric acid per kg of dissolved copper and was linearly related to the percent copper dissolution.The calculated copper dissolution rates obey the Shrinking Core Model.The relative activation energy of the whole biooxidative leaching stages was calculated to be 48.58kJ/mol.
基金Financial support from the State Key Program of the National Natural Science Foundation of China(Grant No.20836009)the Key Laboratory of Saline Lake Resources and Environmental Ministry of Land and Resources,and the Tianjin Key Laboratory of Marine Resources and Chemistry(No.200909)is greatly appreciated.
文摘Zangnan Salt Lake on the south of the Tibet is a type of carbonate lake with high concentrations of lithium,boron,and potassium and obviously it differs from seawater in its chemical composition.An experimental simulation of the caloric evaporation of the lake’s brine was conducted byfirst freezing the brine and then performing isothermal evaporation at 288.15 K.The freezing path and the physicochemical properties of the brine were determined.The crystallization sequence was natron,hydrohalite,halite,sylvite,zabuyelite,trona,aphthitalite,thermonatrite,and borax.Rubidium and cesium salts did not crystallized out but concentrated in the mother solution.The physicochemical properties(density,refractive index,conductivity,and pH)of the liquid phase changed as the evaporation progressed.In the beginning of the evaporation processes,the concentration of potassium ions in the liquid phase gradually increased but later it decreased.A peak value of 55.21 g/L was obtained when the evaporation was 88%complete.When the mineral aphthitalite began to crystallize;the concentra-tions of B2O3,Li+,Rb+,and Cs+gradually increased as the evaporation progressed.When the evaporation was 98%complete,their concentrations in the mother liquor were 40.77 g/L,4.838 g/L,400.17 mg/L and 31.95 mg/L,respectively.This essential fundamental study can provide an important reference for the comprehensive utilization of brines in Zangnan Salt Lake.
