Quartz is, in most cases, the major gangue mineral found in the manganese ore. Mn iron, dissolved from the surface of ore, will determine the interfacial properties of the particles and, thus, their flotation behavior...Quartz is, in most cases, the major gangue mineral found in the manganese ore. Mn iron, dissolved from the surface of ore, will determine the interfacial properties of the particles and, thus, their flotation behavior. In this work, the effect of Mn2+ on quartz flotation was investigated through flotation tests. It was found that quartz can be depressed with Mn2+ and floated with dodecylamine in the pH region 7-8. In order to prove the validity of the findings, UV spectrophotometry, FTIR and SEM-EDS were carried out. UV spectrophotometry tests results show that Mn2+ can competitive adsorb with RNH3+ in the surface of quartz at acidic and neutral pH values. The FTIR measurements and SEM-EDS analysis indicate that Mn2+ forms precipitation and adsorbs on the negatively charged quartz surface, it induces quartz recovery dropping in alkaline pH. Furthermore, in the case of sodium hexametaphosphate(SH), sodium silicate or citric acid, the effects of Mn2+ were also studied. This depression in the given Mn2+ did not disappear. Citric acid is an appropriate modifier to separate quartz depressed by Mn2+ from other ores at pH 7.展开更多
Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. A thermocouple is int...Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. A thermocouple is intrinsically a point temperature measurement method and noncontact 2D temperature distribution cannot be attained by thermocouples. Recently, as a measurement technique with high sensitivity and high response, laser diagnostics has been developed and applied to the actual engine combustions. With these engineering developments, transient phenomena such as start-ups and load changes in engines have been gradually elucidated in various conditions. In this study, the theoretical and experimental research has been conducted in order to develop the noncontact and fast response 2D temperature and concentration distribution measurement method. The method is based on a Computed Tomography （CT） method using absorption spectra of water vapor at 1388 nm. It has been demonstrated that the method has been successfully applied to engine exhausts to measure 2D temperature distributions.展开更多
In this paper, we propose and experimentally demonstrate a compact optical fiber sensor based on a Mach-Zehnder in- terferometer （MZI） cascaded with fiber Bragg grating （FBG） for simultaneous measurement of refrac...In this paper, we propose and experimentally demonstrate a compact optical fiber sensor based on a Mach-Zehnder in- terferometer （MZI） cascaded with fiber Bragg grating （FBG） for simultaneous measurement of refractive index （RI） and temperature. In order to get a proper spectrum, we discuss the effects of different structure parameters of MZI. Using the resonant wavelength of the FBG （DipFBG） and the interference dip of the MZI （Dipl）, the RI and tempera- ture of the surrounding medium can be determined. The sensor has good operation linearity. The experimental results show that the distinctive spectral sensitivities are 0.071 75 nm/℃and -91.766 67 nm/RIU （refraction index unit） for Dip1 and 0.009 09 nm/℃ for DipFBG.展开更多
基金Projects(21176026,21176242)supported by the National Natural Science Foundation of China
文摘Quartz is, in most cases, the major gangue mineral found in the manganese ore. Mn iron, dissolved from the surface of ore, will determine the interfacial properties of the particles and, thus, their flotation behavior. In this work, the effect of Mn2+ on quartz flotation was investigated through flotation tests. It was found that quartz can be depressed with Mn2+ and floated with dodecylamine in the pH region 7-8. In order to prove the validity of the findings, UV spectrophotometry, FTIR and SEM-EDS were carried out. UV spectrophotometry tests results show that Mn2+ can competitive adsorb with RNH3+ in the surface of quartz at acidic and neutral pH values. The FTIR measurements and SEM-EDS analysis indicate that Mn2+ forms precipitation and adsorbs on the negatively charged quartz surface, it induces quartz recovery dropping in alkaline pH. Furthermore, in the case of sodium hexametaphosphate(SH), sodium silicate or citric acid, the effects of Mn2+ were also studied. This depression in the given Mn2+ did not disappear. Citric acid is an appropriate modifier to separate quartz depressed by Mn2+ from other ores at pH 7.
文摘Exhaust gas temperature is an important factor in NOx, THC and PM emissions of engines. Especially 2D temperature and concentration distribution plays an important role for the engine efficiency. A thermocouple is intrinsically a point temperature measurement method and noncontact 2D temperature distribution cannot be attained by thermocouples. Recently, as a measurement technique with high sensitivity and high response, laser diagnostics has been developed and applied to the actual engine combustions. With these engineering developments, transient phenomena such as start-ups and load changes in engines have been gradually elucidated in various conditions. In this study, the theoretical and experimental research has been conducted in order to develop the noncontact and fast response 2D temperature and concentration distribution measurement method. The method is based on a Computed Tomography （CT） method using absorption spectra of water vapor at 1388 nm. It has been demonstrated that the method has been successfully applied to engine exhausts to measure 2D temperature distributions.
基金supported by the National High Technology Research and Development Program of China(No.2013AA014200)the National Natural Science Foundation of China(No.11444001)the Municipal Natural Science Foundation of Tianjin(No.14JCYBJC16500)
文摘In this paper, we propose and experimentally demonstrate a compact optical fiber sensor based on a Mach-Zehnder in- terferometer （MZI） cascaded with fiber Bragg grating （FBG） for simultaneous measurement of refractive index （RI） and temperature. In order to get a proper spectrum, we discuss the effects of different structure parameters of MZI. Using the resonant wavelength of the FBG （DipFBG） and the interference dip of the MZI （Dipl）, the RI and tempera- ture of the surrounding medium can be determined. The sensor has good operation linearity. The experimental results show that the distinctive spectral sensitivities are 0.071 75 nm/℃and -91.766 67 nm/RIU （refraction index unit） for Dip1 and 0.009 09 nm/℃ for DipFBG.
