溶胶-凝胶法制备纳米荧光粉Y4Al2O9:Eu3+的初步研究     

袁曦明  许永胜  于江波  田熙科 《地球科学》2002,27(4):409-412

用溶胶-凝胶法(sol-gel)制备了纳米荧光粉Y4Al2O9: Eu3+,用X射线粉晶衍射对其进行了物相鉴定,表明在900℃已经得到纯相的Y4Al2O9产物,并用透射电镜对其进行形貌和衍射分析,分析结果证明得到的产物为纳米粉末态晶体,产物Y4Al2O9:Eu3+粒径均匀,大致在20～50nm之间,平均粒径为30nm.并用荧光光度计对其荧光光谱进行了研究,光谱表明Eu3+在Y4Al2O9晶格中占据两种不同的位置.用λ =254nm的紫外光激发Y4Al2O9:Eu3+时,产生两条发光谱带,即由于5 D 0→7 F 1的跃迁产生在峰值λ =590nm处的橙色发光带,和5 D 0→7 F 2跃迁在峰值λ =610nm处的红色发光带.  相似文献   

油田污水中Fe2+,S2-,DO及pH值对无机交联体系HPAM-Cr3+CDG成胶性能影响的研究   总被引：1，自引：2，他引：1  

陈艳玲  范畴  杨问华  谭中良  费琪 《地质科技情报》2002,21(2):83-86

在对河南油田下二门矿区油田污水进行全面分析的基础上，研究了污水中Fe^2 ，S^2-，溶解氧（DO）及污水的pH值对无机交联体系聚丙烯酰胺（HPAM）－Cr^3 胶成分散凝胶（CDG）成胶性能的影响。研究结果表明，对于HPAM－Cr^3 体系，污水中Fe^2 ，DO对其成胶性能没有影响；S^2-和污水的pH值对其成胶性能有影响。pH值增大，凝胶强度增强；S^2-浓度增加，则凝胶强度减弱。  相似文献   

青岛近海魁蚶群体等位基因酶遗传变异研究   总被引：7，自引：1，他引：7  

喻子牛  刘必谦 《海洋湖沼通报》1997,(3):33-39

采用淀粉凝胶电泳技术研究了青岛近海魁蚶自然群体的等位基因酶遗传变异。在十种等位基因酶中共检测到了二十二个基因座位，多态位点比例为45．5％，位点有效等位基因数分布从1．000～2．469（平均值1．415），位点杂合度观察值分布为0．000～0．595（平均杂合度0．105±0．023），在六个基因座位上存在相当明显的杂合子缺失现象。文中讨论了杂合子缺失的原因。  相似文献   

CHIMEHERB人工皮在创面愈合过程的病理组织学观察和生物化学分析     

王静凤  楼宝城 《中国海洋大学学报(自然科学版)》1989,(Z3)

作者在研究CHIMEHERB人工皮肤覆盖创面时发现;人工皮肤与创面之间先是一种液面连接,随着创面渗出的减少,出现一种凝胶状的纤维结合蛋白(FN),使人工皮肤牢固地敷贴创面.在愈合过程的不同时期,进行了组织学切片观察和创面物质的生物化学分析.证实:人工皮肤下的纤维结合蛋白与创面上的多种酶聚集,净化了内环境,为上皮细胞生长提供了营养,对烧伤创面起到了良好的保护和促进愈合作用.  相似文献   

C₁₈键合硅胶柱在线富集/FIA-FAAS系统测定海水中痕量重金属   总被引：2，自引：0，他引：2  

庄峙厦  洪华生 《海洋与湖沼》1992,23(3):264-269

基于8-羟基喹啉金属螯合物在C_(18)键合硅胶上的吸附原理,在海水样品中加入少量8-羟基喹啉溶液,建立在线C_(18)键合硅胶柱富集,甲醇洗脱,洗脱液直接进入火焰的流动注射-火焰原子吸收光谱系统(FIA-FAAS)测定海水中痕量Cu,Ni,Cd和Zn的方法。富集倍数达80,进样频率为每小时30次。对Cu Ni,Cd和Zn测定的特征浓度分别为0.30,0.26,0.12和0.07μg/L;检出限(2σ)分别为0.07,0.05,0.02和0.01μg/L;相对标准偏差分别为2.7,2.1,2.8和2.5％;回收率分别为102,98,96和102％。本法快速简便,污染少,灵敏度高。  相似文献   

Use of ultrasonic treatment for extraction of humic acid with inorganic reagents from soil     

A.U. Ramunni  F. Palmieri 《Organic Geochemistry》1985,8(4):241-246

The use of ultrasonic vibrations (1 hr) on the extraction of humic acids (HA) from a brown soil has been compared with the extraction by mechanical stirring (24 hr) with two extractants: 0.5 N and 0.1 M Na₄P₂O₇, followed by extraction with 0.5 N NaOH. In the pyrophosphate extraction, ultrasonic and mechanical treatments produced the same yield of HA. Further extraction with NaOH and mechanical stirring gave higher yields.The elemental composition of HA changed remarkably with both ultrasonic and mechanical systems. The HA extracted with ultrasonic treatment showed a higher ash content and a lower content of COOH and phenolic OH groups. These HA's showed higher optical density at 260 and 450 nm when pyrophosphate-extracted, and lower optical density when NaOH-extracted. Moreover the ultrasonic-treated HA in both extractants showed a lower E₄₀₀/E₆₀₀ ratio.Infrared examination confirmed the difference in chemical characteristics of extracted HA. The HA distribution in the different classes of nominal molecular weights by Sephadex gel filtration was influenced by both ultrasonic and mechanical systems, specially for molecular weights between 5000 and 150,000. It has been noted that the differences due to both systems are less marked than those caused by ssing different extractants.  相似文献   

Development of Easy and Reproducible Immobilization Techniques Using TiO2 for Photocatalytic Degradation of Aquatic Pollutants     

Tusnelda E. Doll  Fritz H. Frimmel 《洁净——土壤、空气、水》2004,32(3):201-213

Two main routes of methods for the preparation of photocatalytic active titanium dioxide films on glass substrates were investigated: (1) the use of titanium dioxide powder and (2) the in situ generation of the catalyst via hydrolysis of titanium tetraisopropoxide (TTIP) or TiCl₄. The activities of the catalyst films were evaluated by measuring the degradation of dichloroacetic acid (DCA), clofibric acid, and terbuthylazine used as model organic compounds. The concentration decrease of DCA and the concentration increase of chloride ions as the decomposition product allowed to distinguish between photocatalytic degradation of DCA and adsorption onto the TiO₂ films. Furthermore, TiO₂ films of the commercially available materials P25 (Degussa) and Hombikat UV100 (Sachtleben Chemie) were used to investigate whether there was a difference in the degradation pathways of terbuthylazine as a model compound. For the experiments mini flow‐through reactors were constructed. The investigated immobilization techniques were easy to handle without need of any expensive equipment. All TiO₂ coatings showed good photocatalytic activities and mechanical stabilities with efficient long‐term stabilities. The best immobilization reproducibility was achieved by the spray coating technique and by the in situ method with the dipping sol‐gel process starting by TTIP. During the continuous use of the TiO₂ films no TiO₂ particles were found in the irradiated solutions.  相似文献   

Properties and Anti-Ultraviolet Activity of Gallic Acid-Chitosan-Gelatin Mixed Gel     

WANG Wenjie  XUE Changhu  MAO Xiangzhao 《中国海洋大学学报(英文版)》2022,21(1):204-212

Hydrogel has high water content and structural similarity with natural extracellular matrix.So it has been widely studied and applied in the field of biomedicine.In order to further develop multifunctional hydrogels,we prepared mixed gels with antiultraviolet properties.This study found that the addition of polysaccharides and polyphenols was beneficial to the rheological,me-chanical properties,and biological activity of the protein.Chitosan(CS)could significantly improve the viscoelasticity,hardness,gel strength,thermal stability and crystallinity of gelatin.Interestingly,the addition of gallic acid(GA)could not only provide significant cross-linking effect,improve gel properties and microstructure,but also improve the UV resistance of the mixed gel.  相似文献   

贵州省旦坪铝土矿钻探施工工艺          下载免费PDF全文

邓鹏  黄明勇  方青  陈涛 《探矿工程》2021,48(3):78-85

贵州正安旦坪铝土矿项目地层岩石破碎,岩溶发育,钻探施工中遇掉块卡钻、套管难以起拔以及溶洞发育等难题。通过优化钻孔结构、合理选择钻进参数,采用跟管钻进配合绳索取心工艺,有效解决了溶洞堆积层的护壁难题,大大提高了溶塌堆积层成孔率。采用聚合物凝胶护壁堵漏减少了破碎地层掉块卡钻事故的发生。反丝套管的使用,减轻了坍塌地层丢套管的风险,提高了钻进效率,节约了钻探成本。采用长套管穿越溶洞,降低了报废工作量,提高了工作进度。物探瞬变电磁法的应用查明了岩溶的空间分布情况,降低了钻遇大溶洞的风险。通过一系列技术措施的实施,如期完成了目标任务。本文对该矿区的施工经验进行了总结,以期为同类钻探施工起到借鉴作用。  相似文献   

多孔介质中酚醛树脂冻胶动态成胶规律   总被引：1，自引：1，他引：0  

史胜龙  王业飞  于海洋  吕鹏 《东北石油大学学报》2012,(1):41-46,63,4

为认识酚醛树脂冻胶在多孔介质中动态成胶行为,通过测定黏度和注入压力随成胶时间的变化,研究酚醛树脂冻胶在安瓿瓶和多孔介质中的静态成胶及多孔介质中动态成胶过程;考察聚合物和交联剂质量分数对成胶时间和冻胶强度的影响.结果表明:静态条件下,酚醛树脂冻胶在多孔介质中的初始和最终成胶时间分别为安瓿瓶内成胶的1～1.5倍和1.5～2倍;多孔介质中,动态初始和最终成胶时间分别为静态条件下的2倍和2～3倍;随聚合物和交联剂质量分数增大,成胶时间缩短,冻胶强度增大,但在成胶过程中冻胶向深部运移的能力降低.后续水驱结果表明:动态成胶过程中,冻胶封堵位置主要集中在岩心入口端,封堵率达99.8%以上;只有当酚醛树脂冻胶可以在多孔介质中产生明显的运移时,冻胶体系才具有深部调剖的能力;当多孔介质的渗透率为8μm2左右,HPAM质量分数小于0.2%,酚醛树脂预聚体质量分数小于0.6%时,冻胶可以进行深部调剖.多孔介质中静态成胶形成的为整体冻胶,而动态成胶形成的为分散的冻胶颗粒.  相似文献