111 research outputs found
Research on the rapid inactivation of typical algae blooms by hydroxyl radical
以典型水华藻铜绿微囊藻、针杆藻和四尾栅藻为研究对象,利用大气压强电离放电高效生成的羟基自由基(·OH)对3种藻进行杀灭.采用荧光染色、流式细胞仪; 和光合活性等生物学方法,确定·OH杀灭的阈值浓度和时间,并观察细胞形态变化.结果表明,当混合藻中铜绿微囊藻、针杆藻和四尾栅藻的初始藻密度分别为1; 9.5*10~4、21.8*10~4和4.90*10~4cells/mL时,; ·OH杀灭的阈值浓度为1.07mg/L,致死时间为4.5s;形态观察结果表明,处理后各种藻的形态是完整的,无内溶质溢出.因此,采用·OH可实现高; 效快速杀灭水华藻,有效保障饮用水安全.Algae blooming in water sources breaks out increasingly and seriously; threatened the water supply safety. Bench scale tests were conducted to; study the effects of ·OH generated from strong ionization discharge and; high pressure water jet cavitation on cell density, cell integrity and; photosynthetic capacity of 3kinds of typical freshwater algae. Algae; species including Microcystis aeruginosa, Synedra sp., and Scenedesmus; quadricuauda were respectively prepared at concentrations of 19.5*10~4,; 21.8*10~4 and 4.90*10~4 cells/mL, and the cell integrity was assessed by; flow cytometry. Results suggested that the ·OH lethal threshold of the; algae was 1.07mg/L within the exposure time of 4.5s. The cell; morphological observation results showed that all the cells were; integral and no cytoplasm composition spilled. Hence, large-scale; production of ·OH is a novel method to inactive typical algae species; efficiently and to protect drinking water safety simultaneously.国家科技支撑计划资助项目; 国家重大科研仪器研制项
Treatment of algae bloom water using ·OH based on conventional drinking water process
我国水体的富营养化日益严重,水源地出现季节性藻类爆发现象,严重威胁饮用水安全。以厦门市莲坂水厂各工艺段出水为研究对象,采用大气压强电离放电产生羟; 基自由基(·OH),分别对水源水、混凝沉淀出水、砂滤出水进行处理,处理时间为4.5 s。当注入总氧化剂浓度为1.8 mg·; L~(-1)时,高藻浓度从25.3*10~4 cells · mL~(-1)降到800 cells ·; mL~(-1);对混凝沉淀出水注入总氧化剂0.6 mg· L~(-1)、砂滤出水注入0.2 mg·; L~(-1)时,藻细胞都未检出;·OH处理后CODMn、TOC及UV254均有明显降低,砂滤出水三卤甲烷小于8; mug·L~(-1);检测的各项指标均达到国家《生活饮用水卫生标准》(GB; 5479-2006)。因此,·OH可快速有效安全地杀灭高藻,为我国高藻水源地饮用水卫生安全保障提供技术支撑。Due to the increasing eutrophication in China, harmful algae blooms; often occur in water body periodically, which poses serious threats to; drinking water safety. Using a strong ionization discharge technology at; atmosphere pressure, ·OH was used to remove algae bloom. Other; conventional process such as coagulation, sedimentation and sand; filtration were applied respectively in the Lianban Water Plant in; Xiamen (China). The total reaction time required in the three water; processes was only 4.5 s. When the total reactive oxidant (TRO); concentration injected to algae bloom water was 1.8 mg·L~(-1), the algae; content was decreased by ·OH from 25.3*10~4 cells·mL~(-1) to 800; cells·mL~(-1). When the TRO that was injected into coagulation,; sedimentation and sand filtration water achieved 0.6 mg·L~(-1) and 0.2; mg·L~(-1), respectively, the algae contents were not detected (ND) in; treated effluents. At the same time, water quality in CODMn, TOC and; UV254 were decreased and the disinfection by-products(DBPs) such as,; trihalomethanes (THMs) concentration was lower than 8 mug·L~(-1) in; treated effluents. The treated effluent, resulting from this technology,; met the requirement of the National Drinking Water Standards (GB; 5479-2006). Therefore, ·OH was effective and safe to remove freshwater; algae without further treatment being required.国家科技支撑计划项目; 国家重大科研仪器研制项目; 科技部创新人才推进计划重点领域创新团
Electrochemical Nanofabrication Using Polyacrylamide Hydrogel as Soft Stamps
电化学刻蚀使用腐蚀性小的电解质溶液,且溶液可使用周期长,是一种环境友好的加工工艺.本文采用聚丙烯酰胺水凝胶(PAg)作为软印章,辅以优化工艺,将电化学湿印章技术(E-WETS)的加工精度从几十微米提高到了200纳米.将新配制的聚丙烯酰胺水凝胶浇注在具有纳米结构的软模板表面,固化后脱模并保存于0.2MOl·l-1kCl溶液中,在合适电位和压力下,对硅片表面金膜进行电化学湿法刻蚀,分别研究了聚丙烯酰胺水凝胶的聚合条件、电化学加工电位以及水凝胶表面压力对加工结果的影响.实验表明,在最优条件下可加工出直径为200纳米的特征点阵结构,且该方法具有较好的可靠性和稳定性。The fabrication resolution of electrochemical wet stamping was enhanced to several hundred nanometers from several ten micrometers by using polycarylamide gel(PAG) as soft stamps and through optimized processes.The PAG stamp was cured on a nanopatterned soft mold and soaked with 0.2 mol.L-1 KCl solution,then contacted with a silicon wafer with gold film and applied with electric field.And the gold nanopatterns were achieved by the selective anodic dissolving,the diameter of fabricated gold spot was around 200 nm.The parameters which affected the fabrication processes have been discussed in detail.supportedbyNationalScienceFoundationofChina(No.91123002); InnovationMethodFundofChina(No.2010IM040100); NationalInstrumentationProgram(No.2011YQ030124
马铃薯遗传转化系统的优化及禽流感病毒(H5N1)基因的导入
通过对以马铃薯 (Solanum tuberosum L .)块茎为受体的农杆菌转化系统进行优化 ,筛选出使三个品种 (鲁引 1号、克新 3号、优金 )的受体均可得到高频分化的培养基 :MS+2 .0 mg/L BA+3.0mg/L ZT+0 .5mg/L NAA+0 .5mg/L GA.对几种农杆菌转化条件的比较研究发现 ,菌体用 Ms+0 .5mg/L GA液体重悬并稀释 4倍 ,与受体于 2 8℃ ,10 0 r/min振荡侵染 2 0~ 30 min,共培养时在分化培养基上加 30 μ mol/L AS(乙酰丁香酮 ) ,16 h弱光照共培养 3d,可使马铃薯品种鲁引 1号的转化效率较常规方法提高 5~ 7倍 .将禽流感病毒 (H5N1)基因与 35S启动子及 nos终止子构建表达载体 p130 1H5N1,直接法转入农杆菌 EHA10 5,用此菌株转化马铃薯得到再生植株 .基因组总 DNA经 PCR和 Southern杂交证明目的基因已整合到马铃薯基因组
Electrochemical Nanofabrication Using Polyacrylamide Hydrogel as Soft Stamps
电化学刻蚀使用腐蚀性小的电解质溶液,且溶液可使用周期长,是一种环境友好的加工工艺. 本文采用聚丙烯酰胺水凝胶(PAG)作为软印章,辅以优化工艺,将电化学湿印章技术(E-WETS)的加工精度从几十微米提高到了200纳米. 将新配制的聚丙烯酰胺水凝胶浇注在具有纳米结构的软模板表面,固化后脱模并保存于0.2 mol·L-1 KCl溶液中,在合适电位和压力下,对硅片表面金膜进行电化学湿法刻蚀,分别研究了聚丙烯酰胺水凝胶的聚合条件、电化学加工电位以及水凝胶表面压力对加工结果的影响. 实验表明,在最优条件下可加工出直径为200纳米的特征点阵结构,且该方法具有较好的可靠性和稳定性.The fabrication resolution of electrochemical wet stamping (E-WETS) was enhanced to several hundred nanometers from several ten micrometers by using polycarylamide gel (PAG) as soft stamps and through optimized processes. The PAG stamp was cured on a nanopatterned soft mold and soaked with 0.2 mol·L-1 KCl solution, then contacted with a silicon wafer with gold film and applied with electric field. And the gold nanopatterns were achieved by the selective anodic dissolving, the diameter of fabricated gold spot was around 200 nm. The parameters which affected the fabrication processes have been discussed in detail.This work was supported by National Science Foundation of China (No. 91123002), Innovation Method Fund of China (No. 2010IM040100) and National Instrumentation Program (No. 2011YQ030124).作者联系地址:厦门大学 固体表面物理化学国家重点实验室,厦门大学化学化工学院,厦门,361005Author's Address: State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen, Fujian 361005, China?通讯作者E-mail:[email protected]
Electric-field-induced selective catalysis of single-molecule reaction
随着单分子电学检测技术的迅速发展,分子电子学的研究不再局限于分子电子学器件的构筑及其电学性质的测量,而且扩展到单分子尺度化学反应过程的探索。然而目前相关的研究仍然局限于理论计算方面,在单分子尺度上实时监测和调控化学反应的活性和选择性是化学领域的长期目标和挑战。针对这一挑战,洪文晶教授课题组与程俊教授课题组合作,自主研发了精密科学仪器,将单个有机分子定向连接在两个末端尺寸为原子级的电极之间,解决了化学反应中分子取向控制的问题.理论计算结果证实了定向电场可以有效地稳定化学反应的过渡态,从而降低反应能垒。该研究工作在化学化工学院洪文晶教授、程俊教授、能源材料化学协同创新中心(iChEM)刘俊扬副研究员的共同指导下完成,由硕士研究生黄晓艳、iChEM博士研究生唐淳、博士研究生李洁琼以及兰州大学的陈力川博士作为共同第一作者,化学化工学院师佳副教授、陈招斌高级工程师、夏海平教授和田中群教授,萨本栋微纳研究院杨扬副教授、环境与生态学院白敏冬教授以及兰州大学张浩力教授参与了研究工作的讨论并给予指导,博士后乐家波、博士研究生郑珏婷、张佩(已毕业)、李瑞豪、李晓慧也参与了研究工作。Oriented external electric fields (OEEFs) offer a unique chance to tune catalytic selectivity by orienting the alignment of the electric field along the axis of the activated bond for a specific chemical reaction; however, they remain a key experimental challenge. Here, we experimentally and theoretically investigated the OEEF-induced selective catalysis in a two-step cascade reaction of the Diels-Alder addition followed by an aromatization process. Characterized by the mechanically controllable break junction (MCBJ) technique in the nanogap and confirmed by nuclear magnetic resonance (NMR) in bottles, OEEFs are found to selectively catalyze the aromatization reaction by one order of magnitude owing to the alignment of the electric field on the reaction axis. Meanwhile, the Diels-Alder reaction remained unchanged since its reaction axis is orthogonal to the electric fields. This orientation-selective catalytic effect of OEEFs reveals that chemical reactions can be selectively manipulated through the elegant alignment between the electric fields and the reaction axis.This work was supported by the National Key R&D Program of China (2017YFA0204902), the National Natural Science Foundation of China (21722305, 21703188, 21673195, 21621091, 51733004, 51525303, and 91745103), the China Postdoctoral Science Foundation (2017M622060), and the Young Thousand Talents Project of China.
该工作得到国家自然科学基金委(21722305、21703188、21673195、51733004、51525303、91745103),国家重点研发计划课题(2017YFA0204902),中国博士后面上基金(2017M622060)的资助,以及固体表面物理化学国家重点实验室、醇醚酯化工清洁生产国家工程实验室、能源材料化学协同创新中心的支持
中国物理海洋学研究70年:发展历程、学术成就概览
本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军
Room Temperature Vulcanized Silicone Rubber Nanocomposite and Its Application to Prevent Pollution Flashover
论文针对目前国内外防污闪涂层技术在实际应用中遇到的急待解决的问题,以研制低成本、高性能的新型纳米复合材料为目标,主要内容与结果如下:
(1) 开发了室温硫化硅橡胶(RTV)制备的新工艺。
(2) 探索了原位有机-无机杂化补强RTV的新型复合方法。正硅酸乙酯原位水解生成的SiO2颗粒粒径分布在30~50nm,明显提高了RTV的力学性能。
(3) 设计并制备了高、低两种表面官能密度的纳米SiO2颗粒,研究了两种改性的纳米SiO2颗粒对RTV力学性能的影响并探索了补强的机理。
(4) 研究了高、低两种表面官能密度的纳米SiO2颗粒对RTV基胶PDMS流变行为的影响,分析了无机纳米颗粒表面结构对PDMS触变性能的作用机制。
(5) 制备了层状Mg-Al LDH及新型的Ca-Fe LDH、Ca-Fe-Ce LDH,并进行了复配改性设计。对比分析了Mg-Al LDH、Ca-Fe LDH、Ca-Fe-Ce LDH与Al(OH)3、Mg(OH)2对RTV热稳定性、阻燃性能的影响。
(6) 制备了新型针状紫外线吸收材料α-FeOOH并进行了表面改性研究。对比了α-FeOOH与纳米ZnO、纳米TiO2对RTV紫外线吸收性能的影响
(7) 研究了电力新型防污闪纳米复合RTV材料的200L中试制备工艺与过程放大,并对产品进行了检测
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