Montmorillonites (MMT) was modified with nonionic surfactant Trion X-100 (OP-10) and anionic surfactants sodium stearate (SSTA) and sodium dodecyl benzene sulfonate (SDBS) respectively. In this study, the effects of a...Montmorillonites (MMT) was modified with nonionic surfactant Trion X-100 (OP-10) and anionic surfactants sodium stearate (SSTA) and sodium dodecyl benzene sulfonate (SDBS) respectively. In this study, the effects of anionic surfactant types and MMT types on modification montmorillonite were investigated. XRD analysis results showed that SSTA/OP-10/MMT and SDBS/OP-10/MMT were successfully obtained. The basal spacing of SSTA/OP-10/MMT reached 5.07nm and the SSTA intercalation reaction was relatively stable. Different types of MMT (Xinjiang natural sodium montmorillonite(MMT-1), Jianping sodium montmorillonite (MMT-2) and artificial sodium montmorillonite(MMT-3)) were modified with SSTA/OP-10. XRD test results showed that MMT-1, MMT-2 and MMT-3 can be modified by SSTA/OP-10. Anion-nonionic organic montmorillonite (SSTA/OP-10/MMT-1, SSTA/OP-10/MMT-2 and SSTA/OP-10/MMT-3 were successfully obtained respectively. The higher expansion capacity was found to be beneficial to organic modification.展开更多
Microwave induced catalytic oxidation has been an important mean for treating high-concentration organic pollutants. Microwave catalyst is the key factor of the pollutants removal efficiency. Manganese oxides are exce...Microwave induced catalytic oxidation has been an important mean for treating high-concentration organic pollutants. Microwave catalyst is the key factor of the pollutants removal efficiency. Manganese oxides are excellent microwave absorbing materials which may play a potential role in treating organic pollutants by microwave induction. Manganese oxides are mainly constituted by [MnO6] octohedra connected to form framework or layered structures, and are usually classified into pyrolusite-ramsdellite family with (1×n) tunnel structure, hollandite-romanechite family with (2×n) tunnel structure, todorokite family with (3×n) tunnel structure and birnessite family with (1×∞) layered structure respectively. However, previous studies focused on the catalytic degradation efficiency or process conditions, lack of discussion on the related mechanism and few studies involved in the structural details of the catalysts.展开更多
China produces the largest amount of graphite raw materials in the world and the largest amount of graphite tailings at the same time. At present, graphite tailings in China are up to 200 million tones, which not only...China produces the largest amount of graphite raw materials in the world and the largest amount of graphite tailings at the same time. At present, graphite tailings in China are up to 200 million tones, which not only occupy large area of land, cause environmental pollutions, the collapes of the tailings dam also threaten the life of local residents.展开更多
Bentonites consisting mainly of montmorillonite are widely utilized in various applications. However, natural bentonites contain many kinds of impurities such as quartz, cristobalite, feldspar, zeolite, calcite etc., ...Bentonites consisting mainly of montmorillonite are widely utilized in various applications. However, natural bentonites contain many kinds of impurities such as quartz, cristobalite, feldspar, zeolite, calcite etc., which can decrease the performance of bentonite. Furthermore, quartz and cristobalite are carcinogenic. Therefore purification of bentonite is critical to its applications. Among the impurities in bentonite, cristobalite is the most difficult one to get rid of because of its tiny particle size and aggregation state.展开更多
目的探讨耳鸣伴听觉过敏患者的临床、听力及心理声学特征以及对患者的影响。方法对2015年3月至2017年3月在广州医科大学附属第二医院耳鼻咽喉科门诊就诊的42例耳鸣合并听觉过敏患者进行纯音测听、耳鸣心理声学特征、响度不适阈(LDL)检测...目的探讨耳鸣伴听觉过敏患者的临床、听力及心理声学特征以及对患者的影响。方法对2015年3月至2017年3月在广州医科大学附属第二医院耳鼻咽喉科门诊就诊的42例耳鸣合并听觉过敏患者进行纯音测听、耳鸣心理声学特征、响度不适阈(LDL)检测,并对耳鸣及听觉过敏严重程度进行评估。结果 42例中,24例以耳鸣为第一主诉(A组),18例以听觉过敏为第一主诉(B组)。耳鸣主调以纯音为主,频率以高频为主,响度多数≤5 d B SL。患者听觉过敏表现为对正常环境声过分关注或刻意回避,伴烦躁、心悸、惊慌、恐惧,戴耳塞、不敢出门。分别检测0.125~8 k Hz频率的LDL,两组在同一频率的LDL差异无统计学意义(P>0.05)。结论不能以响度不适阈判断听觉过敏的严重程度;临床上耳鸣与听觉过敏常相伴随,要重视其对患者工作、生活、睡眠与情绪的影响,应制定和使用适合中国国情的评估量表。展开更多
We studied four tourmalines with different Fe contents from Xinjiang,Sichuan,and Yunnan provinces of China using Mossbauer spectroscopy and single crystal X-ray diffraction.The valence and location of Fe in the four t...We studied four tourmalines with different Fe contents from Xinjiang,Sichuan,and Yunnan provinces of China using Mossbauer spectroscopy and single crystal X-ray diffraction.The valence and location of Fe in the four tourmalines and two heat-treated tourmalines have been investigated.The experimental results showed that Fe in the four tourmalines at room temperature had two valence states and two locations,i.e.Fe2+(Y),Fe2+(Z),Fe3+(Y).After being heated at 850℃ for 48 and 72 h,Fe elements in tourmaline were nearly completely oxidized and mainly occupied Y sites,and a small amount of Fe3+ shifted to Z sites.Simultaneously,the amount of mixed valence state Fe 2.5+ progressively increased with heating time,and electron delocalization occurred between the adjacent sites [Fe2+-Fe3+].展开更多
文摘Montmorillonites (MMT) was modified with nonionic surfactant Trion X-100 (OP-10) and anionic surfactants sodium stearate (SSTA) and sodium dodecyl benzene sulfonate (SDBS) respectively. In this study, the effects of anionic surfactant types and MMT types on modification montmorillonite were investigated. XRD analysis results showed that SSTA/OP-10/MMT and SDBS/OP-10/MMT were successfully obtained. The basal spacing of SSTA/OP-10/MMT reached 5.07nm and the SSTA intercalation reaction was relatively stable. Different types of MMT (Xinjiang natural sodium montmorillonite(MMT-1), Jianping sodium montmorillonite (MMT-2) and artificial sodium montmorillonite(MMT-3)) were modified with SSTA/OP-10. XRD test results showed that MMT-1, MMT-2 and MMT-3 can be modified by SSTA/OP-10. Anion-nonionic organic montmorillonite (SSTA/OP-10/MMT-1, SSTA/OP-10/MMT-2 and SSTA/OP-10/MMT-3 were successfully obtained respectively. The higher expansion capacity was found to be beneficial to organic modification.
文摘Microwave induced catalytic oxidation has been an important mean for treating high-concentration organic pollutants. Microwave catalyst is the key factor of the pollutants removal efficiency. Manganese oxides are excellent microwave absorbing materials which may play a potential role in treating organic pollutants by microwave induction. Manganese oxides are mainly constituted by [MnO6] octohedra connected to form framework or layered structures, and are usually classified into pyrolusite-ramsdellite family with (1×n) tunnel structure, hollandite-romanechite family with (2×n) tunnel structure, todorokite family with (3×n) tunnel structure and birnessite family with (1×∞) layered structure respectively. However, previous studies focused on the catalytic degradation efficiency or process conditions, lack of discussion on the related mechanism and few studies involved in the structural details of the catalysts.
文摘China produces the largest amount of graphite raw materials in the world and the largest amount of graphite tailings at the same time. At present, graphite tailings in China are up to 200 million tones, which not only occupy large area of land, cause environmental pollutions, the collapes of the tailings dam also threaten the life of local residents.
文摘Bentonites consisting mainly of montmorillonite are widely utilized in various applications. However, natural bentonites contain many kinds of impurities such as quartz, cristobalite, feldspar, zeolite, calcite etc., which can decrease the performance of bentonite. Furthermore, quartz and cristobalite are carcinogenic. Therefore purification of bentonite is critical to its applications. Among the impurities in bentonite, cristobalite is the most difficult one to get rid of because of its tiny particle size and aggregation state.
文摘目的探讨耳鸣伴听觉过敏患者的临床、听力及心理声学特征以及对患者的影响。方法对2015年3月至2017年3月在广州医科大学附属第二医院耳鼻咽喉科门诊就诊的42例耳鸣合并听觉过敏患者进行纯音测听、耳鸣心理声学特征、响度不适阈(LDL)检测,并对耳鸣及听觉过敏严重程度进行评估。结果 42例中,24例以耳鸣为第一主诉(A组),18例以听觉过敏为第一主诉(B组)。耳鸣主调以纯音为主,频率以高频为主,响度多数≤5 d B SL。患者听觉过敏表现为对正常环境声过分关注或刻意回避,伴烦躁、心悸、惊慌、恐惧,戴耳塞、不敢出门。分别检测0.125~8 k Hz频率的LDL,两组在同一频率的LDL差异无统计学意义(P>0.05)。结论不能以响度不适阈判断听觉过敏的严重程度;临床上耳鸣与听觉过敏常相伴随,要重视其对患者工作、生活、睡眠与情绪的影响,应制定和使用适合中国国情的评估量表。
基金supported by National Natural Science Foundation of China(Grant No. 40672031)
文摘We studied four tourmalines with different Fe contents from Xinjiang,Sichuan,and Yunnan provinces of China using Mossbauer spectroscopy and single crystal X-ray diffraction.The valence and location of Fe in the four tourmalines and two heat-treated tourmalines have been investigated.The experimental results showed that Fe in the four tourmalines at room temperature had two valence states and two locations,i.e.Fe2+(Y),Fe2+(Z),Fe3+(Y).After being heated at 850℃ for 48 and 72 h,Fe elements in tourmaline were nearly completely oxidized and mainly occupied Y sites,and a small amount of Fe3+ shifted to Z sites.Simultaneously,the amount of mixed valence state Fe 2.5+ progressively increased with heating time,and electron delocalization occurred between the adjacent sites [Fe2+-Fe3+].