Flotation tests, contact angle measurements, infrared spectrum analyses, X-ray analyses and computer simulation were carried out in order to study the activation mechanism of lime-depressed pyrite with oxalic acid. Th...Flotation tests, contact angle measurements, infrared spectrum analyses, X-ray analyses and computer simulation were carried out in order to study the activation mechanism of lime-depressed pyrite with oxalic acid. The results show that the oxalic acid effectively eliminated the hydrophilic calcium film from the surface of pyrite. Therefore, the efficiency of pyrite flotation was also activated. The results indicate that after reacting with hydrophobic insoluble remainders on the surface of pyrite, oxalic acid can pro- duce hydrophilic compounds, such as CaC03, Ca（OH）2 and Fe（OH）3. As a consequence, a flesh pyrite layer was exposed and its flotation activated.展开更多
Objective To study the association between the epidermal growth factor(EGF) gene and intelligence in patients with major depression.Methods Intelligence measurement using Wechsler Adult Intelligence Scale(WAIS) was pe...Objective To study the association between the epidermal growth factor(EGF) gene and intelligence in patients with major depression.Methods Intelligence measurement using Wechsler Adult Intelligence Scale(WAIS) was perfor-med on 120 unrelated patients with major depression and 46 control subjects.Blood was collected from all subjects for extraction of genomic DNA.Four single nucleotide polymorphisms(SNPs) in the EGF gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).Results Mean scores of both score lang and score task,two subtests in WAIS,differed significantly between major depression patients and controls(P<0.0001).Quantitative trait analysis showed that the genetype of rs2250724 was closely associated with score lang and score task in major depression patients.The associations were still significant after 10 000 permutations.Conclusions Although preliminary,our results provide evidence for association between the EGF gene and intelligence in patients with major depression.Genetic variation in the EGF gene may increase the susceptibility of major depression.展开更多
Four modified starches with selected charge characteristics including cationic starch(CAS),carboxymethyl starch(CMS),amphoteric starch(AMS) and soluble starch(SS) were investigated as depressants for diaspore in rever...Four modified starches with selected charge characteristics including cationic starch(CAS),carboxymethyl starch(CMS),amphoteric starch(AMS) and soluble starch(SS) were investigated as depressants for diaspore in reverse flotation test using cationic collector(dodecylamine).Adsorption examination,Zeta potential measurement and Fourier transform infrared(FTIR) spectroscopy were used to clarify the role of the surface charge characteristics of starches in determining the adsorption behavior and depression performance as well as the mineral-starch interaction.Results show that the positively charged starches(CAS and AMS) display higher adsorption amounts and also better depression performance compared with the non-ionic(SS) and anionic starch(CMS),benefiting from the favorable electrostatic attraction with diaspore and also electrostatic repulsion with collector.FTIR spectroscopy proves the presence of hydrogen bonds and chemical complexation between mineral and starches in an integrated manner.展开更多
基金the financial support from the Key Projects in the National Science & Technology Pillar Program for the Eleventh Five-Year Plan (No. 2006BAB02A06)
文摘Flotation tests, contact angle measurements, infrared spectrum analyses, X-ray analyses and computer simulation were carried out in order to study the activation mechanism of lime-depressed pyrite with oxalic acid. The results show that the oxalic acid effectively eliminated the hydrophilic calcium film from the surface of pyrite. Therefore, the efficiency of pyrite flotation was also activated. The results indicate that after reacting with hydrophobic insoluble remainders on the surface of pyrite, oxalic acid can pro- duce hydrophilic compounds, such as CaC03, Ca（OH）2 and Fe（OH）3. As a consequence, a flesh pyrite layer was exposed and its flotation activated.
基金Supported by National High Technology Research and Development Program of China (863 Program) (2006AA02A407)National Basic Research Program of China (973 Program) (2010CB529603)Beijing Natural Science Foundation (7102109)
文摘Objective To study the association between the epidermal growth factor(EGF) gene and intelligence in patients with major depression.Methods Intelligence measurement using Wechsler Adult Intelligence Scale(WAIS) was perfor-med on 120 unrelated patients with major depression and 46 control subjects.Blood was collected from all subjects for extraction of genomic DNA.Four single nucleotide polymorphisms(SNPs) in the EGF gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).Results Mean scores of both score lang and score task,two subtests in WAIS,differed significantly between major depression patients and controls(P<0.0001).Quantitative trait analysis showed that the genetype of rs2250724 was closely associated with score lang and score task in major depression patients.The associations were still significant after 10 000 permutations.Conclusions Although preliminary,our results provide evidence for association between the EGF gene and intelligence in patients with major depression.Genetic variation in the EGF gene may increase the susceptibility of major depression.
基金Projects(50804055,50974134) supported by the National Natural Science Foundation of ChinaProject(09JJ3100) supported by Hunan Provincial Natural Science Foundation,China
文摘Four modified starches with selected charge characteristics including cationic starch(CAS),carboxymethyl starch(CMS),amphoteric starch(AMS) and soluble starch(SS) were investigated as depressants for diaspore in reverse flotation test using cationic collector(dodecylamine).Adsorption examination,Zeta potential measurement and Fourier transform infrared(FTIR) spectroscopy were used to clarify the role of the surface charge characteristics of starches in determining the adsorption behavior and depression performance as well as the mineral-starch interaction.Results show that the positively charged starches(CAS and AMS) display higher adsorption amounts and also better depression performance compared with the non-ionic(SS) and anionic starch(CMS),benefiting from the favorable electrostatic attraction with diaspore and also electrostatic repulsion with collector.FTIR spectroscopy proves the presence of hydrogen bonds and chemical complexation between mineral and starches in an integrated manner.
