杭州市典型共站移动通信基站周围电磁环境影响调查与研究

在4G基站快速增加的背景下,基站共站已成为较为普遍的架设方式.根据移动通信基站的发展趋势和工作原理,选取典型共站的移动通信基站,按照测量规范进行布点,了解基站周围电场强度的大小、楼顶架设基站的建筑物内部电场强度,以及周围建筑物室内的电场强度垂直方向的变化规律.分析结果表明,只要基站选址合理,天线面板角度与高度能尽量避开周围环境保护目标的方向,共站的基站运营时周围环境的电磁辐射水平可以满足相应的评价标准,不会对周围的环境造成明显的影响.     

铁/钴氮氟掺杂二氧化钛膜的制备研究

通过溶胶-凝胶法制备Fe,N,F-TiO2膜和Co,N,F-TiO2膜的光催化剂,以亚甲基蓝为模型污染物,探讨了制备两种膜的最佳煅烧温度、镀膜层数和铁/钴掺杂量。结果表明,当煅烧温度400℃,镀膜层数4层,Fe/Ti=0.05%,Co/Ti=0.02%时,得到的Fe,N,F-TiO2膜和Co,N,F-TiO2膜的可见光催化活性最高。其中Fe,N,F-TiO2膜的光催化活性要略优于Co,N,F-TiO2膜。     

掺杂过渡金属的TiO2/累托石复合材料的制备及其光催化性能研究

以累托石为载体,钛酸四丁酯和硝酸铜为原料,采用溶胶-凝胶法制备出了掺杂过渡金属铜的TiO2/累托石复合光催化材料,并对其进行了X射线衍射(XRD)和红外光谱(FT-IR)的表征.同时考察了复合材料在紫外光照下对对氯苯酚的光催化活性,研究了铜掺杂量和煅烧温度等因素对复合材料光催化活性的影响,探讨了过渡金属掺杂改性TiO2的机理及对氯苯酚的光催化降解机理.实验结果表明:在制备复合材料的过程中,累托石的层状结构遭到一定程度的破坏;复合材料中的TiO2主要是以大部分的锐钛矿型和小部分的金红石型的混合形态存在;负载累托石后复合材料的吸附性能明显增加,掺杂铜的TiO2/累托石复合材料的光催化活性要高于未掺杂铜的TiO2/累托石复合材料,并且当掺铜量为0.5%(质量分数),煅烧温度为500℃时,复合材料对对氯苯酚的光催化去除率达到最大;苯醌类物质可能是对氯苯酚光降解的中间产物.     

Biogenic C-doped titania templated by cyanobacteria for visible-light photocatalytic degradation of Rhodamine B

Cyanobacteria, which occurred in eutrophic water harvest solar light to carry out photosynthesis with high efficiency. In this work, cyanobacteria （Microcystis sp.） were used as biotemplate to synthesize titania structure. The synthesized titania sample had similar morphology to that of the original template in spite of the fragile unicellular structures and extremely high water content of cyanobacterial cells. Incorporation of biogenic C, as well as the morphology inherited from biotemplate improved visible- light absorbance of the titania structure. The sample exhibited higher visible-light photocatalytic activity than commercial titania photocatalyst Degussa P25 for Rhodamine B （RhB） degradation. Compared with those C-doped titania photocatalysts prepared by other methods, cyanobacteria templated titania photocatalyst offer some potential for competitive advantages. The reported strategy opened up a new use for the cyanobacteria. It could also be used for titania in applications such as treatment of polluted water, dye-sensitized solar cells, or other regions.     

Immigrant Pantoea agglomerans embedded within indigenous microbial aggregates：A novel spatial distribution of epiphytic bacteria

Immigrant bacteria located on leaf surfaces are important to the health of plants as well as to people who consume fresh fruits and vegetables. However, the spatial distribution and organization of these immigrant bacteria on leaf surfaces are still poorly understood. To examine the spatial organization of these strains, two bacterial strains on tobacco leaves： （1） an indigenous strain, Pseudomonas stutzeri Nov. Y2011 labeled with green fluorescent protein, and （2） an immigrant strain Pantoea agglomerans labeled with cyan fluorescent protein isolated from pear, were studied. Under moist conditions, P. agglomerans cells quickly disappeared from direct observation by laser- scanning confocal microscopy, although elution results indicated that large amounts of live cells were still present on the leaves. Following exposure to desiccation stress, particles of cyan fluorescent protein-labeled P. agglomerans were visible within cracked aggregates of P. stutzeri Nov. Y2011. Detailed observation of sectioned aggregates showed that colonies of immigrant P. agglomerans were embedded within aggregates of P. stutzeri Nov. Y2011. Furthermore, carbon-resource partitioning studies suggested that these two species could coexist without significant nutritional competition. This is the first observation of an immigrant bacterium embedding within aggregates of indigenous bacteria on leaves to evade harsh conditions in the phyllosphere.     

硼掺杂CeO2/TiO2光催化剂的制备及其活性研究

在三氯化钛和钛酸丁酯水解过程中引入硼酸、硝酸铈,制备了具有可见光活性的硼(B)掺杂CeO₂/TiO₂复合氧化物光催化剂,采用XRD、DRS、XPS等手段进行表征,以偶氮染料酸性红B为模型污染物评估了催化活性.结果表明,硝酸铈加入量影响催化剂的吸收带边,随用量增加,吸收带边红移至481nm(Ce/Ti=1.0,摩尔比),继续增加用量,吸收带边轻微蓝移.催化剂晶相组成与焙烧温度有关,500℃时焙烧样品主要由立方晶型CeO₂和锐钛矿TiO₂组成,焙烧温度高于700℃时,TiO₂转化为金红石型,CeO₂则无显著变化.随焙烧温度升高,催化剂吸收带边明显蓝移,综合考虑催化剂稳定性和太阳能利用,认为500℃焙烧较为合适.B1s XPS显示仅有少量B原子进入复合氧化物晶格取代了氧原子,主要以B₂O₃形式存在.酸性红B降解试验显示B掺杂CeO₂/TiO₂可以提高TiO₂的催化活性,紫外光辐射10min最高可使96.0%的酸性红B分解,且反应彻底,表现出较强的氧化能力,但Ce/Ti>0.5(摩尔比)时催化活性显著下降.     

可见光下掺氮TiO_2分子印迹聚合物的选择性光降解

采用表面分子印迹技术,以溶胶-凝胶法制备的掺氮TiO_2为基质、水杨酸为模板分子、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯和偶氮二异丁腈分别为交联剂和引发剂制备了掺氮TiO_2分子印迹聚合物。通过傅立叶红外光谱(FT-IR)、X射线衍射(XRD)、透射电镜(TEM)、紫外-可见光漫反射吸收光谱(UV-Vis DRS)和低温N2物理吸附-脱附等技术对制备样品进行了表征。结果表明,样品均为锐钛矿相,粒径10~20 nm且分布均匀;氮掺杂引起光吸收带边红移;表面分子印迹技术在掺氮TiO_2表面形成的有机聚合物层增大了粒径,但改变了回滞环形状及孔径分布,形成了大量孔径为2.2 nm的小孔并增大了比表面积;可见光下对水杨酸、甲基橙、苯甲酸的降解选择系数在1.1~1.7之间,具有良好的选择性。     

五水共治的意义思考

在新时期的大背景之下,环境发展不再是单纯地依靠摧毁生态环境来获取相关的经济效益,而是与自然和谐共处,走一条可持续发展的道路。浙江省委省政府以及相关的环保部门在这一思想的指导下,提出了"五水共治"的发展战略。这在浙江省的历史上尚属首次,也是我省政府对于新时期的可持续发展政策的深刻理解以及灵活变通的结果。因此,笔者将就"五水共治"的意义与读者作一些探讨,以飨读者。     

“五水共治”背景下的小城市污水工程规划与建设——以浙江省庆元县松源镇为例

2013年底,在浙江省委十三届四次全会上,"治污水、防洪水、排涝水、保供水、抓节水"——即"五水共治"被首次提出。2014年1月,浙江省第十二届人大二次会议上,省长李强的政府工作报告中,加强污水治理被列为为民办实事的十件之首。本文以"五水共治",重点在水污染治理和防洪排涝工程的建设和完善,即"治污为主,突出重点;水岸并举,系统治理"。     

分洪区数字地形模型建立及其应用

从实用的角度介绍了建立分洪区数字地形模型（ＤＴＭ）方程,并给出了在分洪区信息可视化、分洪区特征曲线生成、分洪区二维洪水演进等等方面的应用。