Cs Rb V series low temperature sulphuric acid catalyst was prepared for the first time by using carbonized mother liquor containing alkali metal salts. The results show that the conversion of SO 2 on catalyst prepared...Cs Rb V series low temperature sulphuric acid catalyst was prepared for the first time by using carbonized mother liquor containing alkali metal salts. The results show that the conversion of SO 2 on catalyst prepared directly with carbonized mother liquor could reach to 24.8% at 410?℃. If n (Na)/ n (V) was adjusted properly, the conversion of SO 2 could be increased to 35.6% at 410?℃. Refined carbonized mother liquor could make the catalytic activity even higher at low temperature, the conversion of SO 2 could be increased to 36.65% at 410?℃. The catalyst was examined with differential thermal analysis. It was found that both endothermic peaks and exothermic peaks of catalyst shifted forward obviously and the catalyst possessed higher activity at low temperature.展开更多
Glutamic acid and gamma-aminobutyric acid (GABA) influence iron content in the substantia nigra and globus pallidus, although the mechanisms of action remain unclear. The present study measured iron content and change...Glutamic acid and gamma-aminobutyric acid (GABA) influence iron content in the substantia nigra and globus pallidus, although the mechanisms of action remain unclear. The present study measured iron content and changes in divalent metal transporter 1 (DMT1) and hephaestin expression in the substantia nigra and caudate putamen, and explored the effects of GABA and glutamic acid on iron metabolism. Results demonstrated that iron content and DMT1 non iron response element [DMT1(-IRE)] expression were significantly greater but hephaestin expression was significantly lower in the caudate putamen of the monosodium glutamate group compared with the control group. No significant difference in iron content was detected between the GABA and control groups. DMT1(-IRE) expression was significantly reduced, but hephaestin expression was significantly increased in the GABA group compared with the control group. In addition, there was no significant difference in tyrosine hydroxylase expression between monosodium glutamate and GABA groups and the control group. These results suggested that glutamate affected iron metabolism in the caudate putamen by increasing DMT1(-IRE) and decreasing hephaestin expression. In addition, GABA decreased DMT1(-IRE) expression in the caudate putamen.展开更多
Autism spectrum disorder (ASD) is a range of complex neurodevelopment disorders, characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior. Its d...Autism spectrum disorder (ASD) is a range of complex neurodevelopment disorders, characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior. Its diagnosis is very difficult and consists of only clinical criteria. The aim of this study is to confirm autism disorder, among three children (2 girls and 1 boy), recruited in a social association of children in a precarious situation, located in Rabat, Morocco, and to evaluate some biological and neurobiological parameters among these children. The confirmation of autistic status is realized using Questionnaire (E2) and the evaluation of biological parameters (organic acids, urinary peptides, toxic metals and essential elements) is done in urine and hair of these children. Obtained children’s scores of E2 Questionnaire, is found in the favor of autism. Moreover, abnormal levels of urinary organic acids, urinary peptides, toxic and essential metals are observed.展开更多
In trace Li analysis with degenerate four-wave mixing(DFWM) method, acid anions and major metallic elements are dominant interferences in Li-containing samples. To better use DFWM technique to analyze trace Li in actu...In trace Li analysis with degenerate four-wave mixing(DFWM) method, acid anions and major metallic elements are dominant interferences in Li-containing samples. To better use DFWM technique to analyze trace Li in actual samples, we study their effects on Li DFWM signal intensity. It is found that K, Cs, and Ni can enhance the Li DFWM signal, SO2-4,PO3-4, Cl-, and Ca can cause significant suppression, and NO3-, Mg, Ba, Sr, and Na almost have no effects. Finally, we use H3BO3 to eliminate the depressive effects of chlorides on Li DFWM signal. The result is also of reference in other trace elements analysis with DFWM.展开更多
Solution equilibrium calculations were performed in this study to understand the impact of contaminant metal ions on the precipitation efficiency of selected rare earth elements(Ce^(3+),Nd^(3+),and Y^(3+))using oxalic...Solution equilibrium calculations were performed in this study to understand the impact of contaminant metal ions on the precipitation efficiency of selected rare earth elements(Ce^(3+),Nd^(3+),and Y^(3+))using oxalic acid as a precipitant.Trivalent metal ions,Al^(3+) and Fe^(3+),are found to considerably affect the precipitation efficiency of REEs.When Al^(3+) and Fe^(3+)concentrations are increased by 1×10^(−4) mol/L,in order to achieve an acceptable cerium recovery of 93%from solutions containing 1×10^(−4) mol/L Ce^(3+),oxalate dosage needs to increase by 1.2×10^(−4) and 1.68×10^(−4) mol/L,respectively.Such great impacts on the required oxalate dosage are also observed for Nd^(3+) and Y^(3+),which indicates that oxalic acid consumption and cost will be largely increased when the trivalent metal ions exist in REE-concentrated solutions.Effects of the divalent metal ions on the oxalate dosage are minimal.Furthermore,solution equilibrium calculation results show that the precipitation of Fe^(3+) and Ca^(2+)(e.g.,hematite and Ca(C_(2)O_(4))∙H_(2)O(s))likely occurs during the oxalate precipitation of REEs at relatively high pH(e.g.,pH 2.5),which will reduce rare earth oxalate product purity.In addition to the metal ions,anionic species,especially SO_(4)^(2-),are also found to negatively affect the precipitation recovery of REEs.For example,when 0.1 mol/L SO_(4)^(2-) occurs in a solution containing 1×10^(−4) mol/L Ce^(3+) and 4×10^(−4) mol/L oxalate,the pH needs to be elevated from 2.0 to 3.3 to achieve the acceptable recovery.Overall,findings from this study provide guidance for the obtainment of high-purity rare earth products from solutions containing a considerable amount of contaminant metal ions by means of oxalic acid precipitation.展开更多
Determination of thirty four trace metal elements in electronic high purity hydrochloric acid by ICP-MS (Standard Condition, Plasma Screen Condition) with membrane desolvation was described. Matrix effects were compen...Determination of thirty four trace metal elements in electronic high purity hydrochloric acid by ICP-MS (Standard Condition, Plasma Screen Condition) with membrane desolvation was described. Matrix effects were compensated by adding rhodium as the internal standard. Detection limits is 0.1 to 100 ng/L; the recovery of the method is 90%-110%. Long term RSD was less than 5%. The results from ICP and ICP-MS are correspondent. ICP-MS improves the accuracy and efficiency of analyses.展开更多
文摘Cs Rb V series low temperature sulphuric acid catalyst was prepared for the first time by using carbonized mother liquor containing alkali metal salts. The results show that the conversion of SO 2 on catalyst prepared directly with carbonized mother liquor could reach to 24.8% at 410?℃. If n (Na)/ n (V) was adjusted properly, the conversion of SO 2 could be increased to 35.6% at 410?℃. Refined carbonized mother liquor could make the catalytic activity even higher at low temperature, the conversion of SO 2 could be increased to 36.65% at 410?℃. The catalyst was examined with differential thermal analysis. It was found that both endothermic peaks and exothermic peaks of catalyst shifted forward obviously and the catalyst possessed higher activity at low temperature.
基金the National Natural Science Foundation of China, No. 30570957the Natural Science Foundation of Hebei Province, No. C2006000152, C2007000251
文摘Glutamic acid and gamma-aminobutyric acid (GABA) influence iron content in the substantia nigra and globus pallidus, although the mechanisms of action remain unclear. The present study measured iron content and changes in divalent metal transporter 1 (DMT1) and hephaestin expression in the substantia nigra and caudate putamen, and explored the effects of GABA and glutamic acid on iron metabolism. Results demonstrated that iron content and DMT1 non iron response element [DMT1(-IRE)] expression were significantly greater but hephaestin expression was significantly lower in the caudate putamen of the monosodium glutamate group compared with the control group. No significant difference in iron content was detected between the GABA and control groups. DMT1(-IRE) expression was significantly reduced, but hephaestin expression was significantly increased in the GABA group compared with the control group. In addition, there was no significant difference in tyrosine hydroxylase expression between monosodium glutamate and GABA groups and the control group. These results suggested that glutamate affected iron metabolism in the caudate putamen by increasing DMT1(-IRE) and decreasing hephaestin expression. In addition, GABA decreased DMT1(-IRE) expression in the caudate putamen.
文摘Autism spectrum disorder (ASD) is a range of complex neurodevelopment disorders, characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior. Its diagnosis is very difficult and consists of only clinical criteria. The aim of this study is to confirm autism disorder, among three children (2 girls and 1 boy), recruited in a social association of children in a precarious situation, located in Rabat, Morocco, and to evaluate some biological and neurobiological parameters among these children. The confirmation of autistic status is realized using Questionnaire (E2) and the evaluation of biological parameters (organic acids, urinary peptides, toxic metals and essential elements) is done in urine and hair of these children. Obtained children’s scores of E2 Questionnaire, is found in the favor of autism. Moreover, abnormal levels of urinary organic acids, urinary peptides, toxic and essential metals are observed.
基金supported by the National "973" Plan Preliminary Study Special of China(Nos.2012CB723407 and 2010CB434811)the Northwest University Science Foundation(No.13NW12)the Shaanxi Provincial Department of Education Project(No.12JK0599)
文摘In trace Li analysis with degenerate four-wave mixing(DFWM) method, acid anions and major metallic elements are dominant interferences in Li-containing samples. To better use DFWM technique to analyze trace Li in actual samples, we study their effects on Li DFWM signal intensity. It is found that K, Cs, and Ni can enhance the Li DFWM signal, SO2-4,PO3-4, Cl-, and Ca can cause significant suppression, and NO3-, Mg, Ba, Sr, and Na almost have no effects. Finally, we use H3BO3 to eliminate the depressive effects of chlorides on Li DFWM signal. The result is also of reference in other trace elements analysis with DFWM.
文摘Solution equilibrium calculations were performed in this study to understand the impact of contaminant metal ions on the precipitation efficiency of selected rare earth elements(Ce^(3+),Nd^(3+),and Y^(3+))using oxalic acid as a precipitant.Trivalent metal ions,Al^(3+) and Fe^(3+),are found to considerably affect the precipitation efficiency of REEs.When Al^(3+) and Fe^(3+)concentrations are increased by 1×10^(−4) mol/L,in order to achieve an acceptable cerium recovery of 93%from solutions containing 1×10^(−4) mol/L Ce^(3+),oxalate dosage needs to increase by 1.2×10^(−4) and 1.68×10^(−4) mol/L,respectively.Such great impacts on the required oxalate dosage are also observed for Nd^(3+) and Y^(3+),which indicates that oxalic acid consumption and cost will be largely increased when the trivalent metal ions exist in REE-concentrated solutions.Effects of the divalent metal ions on the oxalate dosage are minimal.Furthermore,solution equilibrium calculation results show that the precipitation of Fe^(3+) and Ca^(2+)(e.g.,hematite and Ca(C_(2)O_(4))∙H_(2)O(s))likely occurs during the oxalate precipitation of REEs at relatively high pH(e.g.,pH 2.5),which will reduce rare earth oxalate product purity.In addition to the metal ions,anionic species,especially SO_(4)^(2-),are also found to negatively affect the precipitation recovery of REEs.For example,when 0.1 mol/L SO_(4)^(2-) occurs in a solution containing 1×10^(−4) mol/L Ce^(3+) and 4×10^(−4) mol/L oxalate,the pH needs to be elevated from 2.0 to 3.3 to achieve the acceptable recovery.Overall,findings from this study provide guidance for the obtainment of high-purity rare earth products from solutions containing a considerable amount of contaminant metal ions by means of oxalic acid precipitation.
文摘Determination of thirty four trace metal elements in electronic high purity hydrochloric acid by ICP-MS (Standard Condition, Plasma Screen Condition) with membrane desolvation was described. Matrix effects were compensated by adding rhodium as the internal standard. Detection limits is 0.1 to 100 ng/L; the recovery of the method is 90%-110%. Long term RSD was less than 5%. The results from ICP and ICP-MS are correspondent. ICP-MS improves the accuracy and efficiency of analyses.
