改性双氰胺-甲醛树脂对再生水的脱色效果

为了降低再生水的色度,通过正交试验的方法,以双氰胺-甲醛树脂为主体,分别以硫酸1+1(由1份浓硫酸与1份纯水制成)和氯化铵为改性剂制备改性双氰胺-甲醛脱色剂,并筛选最优脱色剂。结果表明,经氯化铵改性的双氰胺-甲醛脱色剂对再生水的脱色效果更好,且在双氰胺∶甲醛∶氯化铵∶水为1∶2. 3∶1∶4. 4(物质的量之比)、温度为70℃、反应时间为3 h条件下制备的脱色剂的脱色效果最好。采用该脱色剂进行中试,脱色效果良好,在进水染料浓度为20mg/L的条件下,沉淀池出水浓度在8 mg/L以下,脱色率超过60%。     

乙酰丙酮分光光度法测定人造板材甲醛含量的研究

建立了分光光度法测定室内装修板材中甲醛含量的测定方法。以水为提取剂,提取板材中的甲醛,活性炭脱色,研究了蒸馏时间、磷酸用量、水浴温度等对甲醛提取效果的影响。对实际样品进行连续5次测定,方法精密度为0.77%～6.5%,回收率为91.6﹪～98.7﹪,方法线性范围为0.50～80ug/25mL。经标准物质验证,结果与标准值相符。是对国家标准方法的补充,适合于不同甲醛含量范围的人造板材样品分析。     

还原石墨烯对白腐菌降解脱色染料活性艳红X-3B的影响

白腐菌被证实可以用于分解污水中毒性大、难降解的染料.研究表明纳米材料可能干扰白腐菌生长和活性,因此探究纳米材料对白腐菌降解染料的影响迫在眉睫.评估了白腐菌降解染料活性艳红X-3B过程中不同浓度还原石墨烯对白腐菌生长和染液褪色的影响,并探讨了石墨烯对染料的吸附的贡献.结果显示,在染料降解过程中,石墨烯使得白腐菌水肿,随着石墨烯浓度的增加,白腐菌湿重增加、干重减少,但石墨烯对培养体系p H值影响不大.白腐菌能彻底降解染料,但耗时较长,加入石墨烯能加快褪色效率.石墨烯本身是良好的吸附剂,使白腐菌附近的局部染料浓度提高,因此促进了染料快速脱色.     

新装修办公室内空气污染的消除试验

以一个新装修的办公室为研究对象,对室内的污染状况进行了检测。从控制污染源和消除室内空气污染两方面进行了净化试验。试验结果表明,在有紫外线灯照射时,用臭氧水对空间和人造板表面进行喷雾,同时保持室内高臭氧浓度的方法对降低人造板的甲醛散发量有明显效果;利用夜间产生高浓度臭氧、白天产生低浓度臭氧结合活性炭吸附的方法能有效消除室内空气中的甲醛和氨气。     

室内空气中甲醛的污染与治理

采用4160型便携式甲醛分析仪，对新建住宅室内甲醛浓度进行检测，比较甲醛消除剂使用前后家具内甲醛的浓度变化。结果表明，各个房间中，甲醛浓度由低到高的排列顺序依次为客厅〈餐厅〈主卧〈次卧〈书房，在门窗关闭条件下室内甲醛浓度超标率13．5％。以人造板为主材的家具内甲醛浓度高达0．43-1．63mg／m^3，使用甲醛消除剂后30min抽屉及橱柜内甲醛去除率达59．7％及73．1％。甲醛污染宜采用综合防治措施进行治理。     

水质检验中锰的测定方法探讨

过硫酸铵分光光度法和甲醛肟分光光度法是基层水厂常用检测锰的方法。本文针对不同的锰测定方法展开研究,分析了浊度对不同方法的干扰情况。结果发现在水质条件相同时,浊度对两种方法有不一致的干扰情况,得到过硫酸铵分光光度法可排除浊度干扰,并提出测定锰的优选方法。     

新催化褪色光度法高灵敏测定食品中痕量I~-的研究

本文研究了在0.1mol·dm-3的柠檬酸介质中,I-催化碘酸根氧化灿烂绿褪色的适宜条件与影响因素,通过正交试验筛选出优化的催化氧化组合,建立了催化动力学褪色光度法测定痕量I-的新方法.该法用于环境样品、生物材料、食品等实际样品中的I-测定,多数常见离子无干扰,方法简便,选择性好,结果可靠.     

强化木地板藏三大漏洞

长期以来,曾经把厂商、消费者、行业管理层几方都弄到尴尬境地的强化木材板转数、甲醛含量、褪色等问题,将由于对旧标准的修改、补充而得到解决.由于受非典疫情的干扰,原定的新标准出台时间可能推迟,但是新标准在年内出台已成定局.强化木地板已经有了国家标准,为什么还会带给消费者、厂商、管理层麻烦?从国家人造板检测中心主任吕斌和宏耐木地板总经理李卫对旧标准漏洞的分析中,可以看出个中缘由.     

分光光度法测定纺织品中甲醛的不确定度评价

根据GB/T 2912.1-2009标准,采用乙酰丙酮分光光度法测定纺织品中游离和水解的甲醛。本文通过对不确定度分量的5个主要来源进行分析,对测量结果的不确定度进行了评价。标准物质和最小二乘法拟合标准曲线时所产生的不确定度对总的不确定度贡献较大。     

天然沸石对食物油脱色工艺的研究

利用天然沸石对压滤大豆油进行了脱色研究。通过沸石的使用量、粒度、脱色时间、脱色温度等条件考察,确定天然沸石用量为8%,脱色温度100℃;脱色时间60 min效果最佳。     

浅析高速公路工程招投标中的最低评标价法

结合目前高速公路施工项目招投标活动的实际情况,阐述了最低评标价法的概念,归纳了其优点及存在问题,对完善最低评标价法提出几点策略,以期促进招标投标市场更加规范有序。     

Place-Making in Megaprojects in Melbourne

This article analyses state-led place-making practices in Melbourne. The two levels of government that influence planning in Melbourne make much of the city as ‘culturally vibrant’ and ‘creative’, and have incorporated creative city-inspired place-making principles into many layers of the planning system. An examination of the development of two mixed-use megaprojects in central Melbourne reveals however that ideals of culturally engaging public places, and indeed of creative landscapes for middle-class consumption, wither in the face of more basic imperatives for economic development. In these case studies the ‘creative city’, no matter how the idea is interpreted, has little traction either as a set of inclusive place-making principles or as a gentrification strategy. The article concludes that the creative city-inspired place-making objectives in the planning system at both state and local levels are ambiguous in their overall intents and completely unsupported by statutory controls. Such place-making objectives as are realised are the compromised results of the interplay of uncoordinated decisions, delivered at the pleasure of the developer.     

Pathogens in septage in Vietnam

Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 ova l^− 1, and were detected in all septage sludge samples with an average of 16,000 ova l^− 1. Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.     

新时期广东城市化的新特点

新时期广东城市化出现以下特点:知识源导向、城市由单体向群体化发展、产业集群推动、政府主导自上而下的集约化发展、城镇化向城市化转变、由重“数量”发展向重“质量”发展的转变。     

在市场中实践在实践中学习在学习中进步--工程公司市场化进程的回顾与展望

近两年来，工程公司在提高市场竞争意识、推动市场化进程中做了大量工作，其中坚持走出去的方针是我们自我加压、推行加快市场化步伐的一个重要战略步骤。     

新形势下高校强化基建财务管理的探讨

在市场条件下高校基建财务人员在加强日常财务管理的同时,必须树立起高度的工作责任心,抓好事前监督、事中监督、事后监督三个环节,全面理解、贯彻执行《高等学校财务制度》,管好用好各项基本建设资金,提高基建财务管理水平,更好地完成高校各项基建任务,以有限的投资,最快的建设速度,获得最大的投资效益。     

Experiences in radon-safe building in Finland

A study was made of radon-safe buildings in 300 Finnish low-rise residential buildings using data obtained from a questionnaire study. The study also aims at finding the main defects in design and implementation and how the guidance given on radon-safe buildings in slab-on-grade houses has been followed. According to the guidelines, the prevention of the flow of radon-bearing air from the soil into the house is recommended to be carried out through installation of aluminised bitumen felt and use of elastic sealants. Second, as a precaution perforated piping should be installed in the subsoil of the floor slab. The median indoor radon concentration in the houses was 155 Bq/m3. This is 32% lower than the median of the estimated reference values. The action level of 200 Bq/m3 was still exceeded in 40% of the houses. In most houses with slab-on-grade the prevention was based only on the installation of a sub-slab depressurisation system. Sealing was performed in a low number of houses. In 80% of houses with a sub-slab piping connected to an operating fan, radon concentration was below the action level of 200 Bq/m3. In houses with piping but no fan, the corresponding fraction was only 45%. Sub-slab piping without a fan had no remarkable effect on radon concentration. In houses with crawl-space and edge-thickened slabs, radon concentrations were low. The choice of foundation system thus significantly affects the indoor radon concentration. The importance of complete and careful sealing work should be stressed in advice and guides concerning radon prevention.     

浅谈我国工程项目建设成本控制存在的问题

结合目前我国施工企业工程项目成本管理现状,对工程项目成本管理过程中存在的问题进行了较详细的分析,并提出了一些解决问题的办法,以做好项目成本控制工作,进而增强企业经济实力。     

2008年日本火灾情况

<正>1火灾总数在2008年(1～12月),日本发生的火灾总数为52 394起,与2007年相比减少了2 188起(4.0%)。这相当于平均1天大约发生143起火灾,每10min发生一起火灾。火灾类别(见表1)。     

Variation in property taxation in Tulsa

Conclusions It may be reasonably concluded from this study that the range of variation in these ratios of assessed to actual value are of a reasonable size for the great majority of cases. The frequency distribution of these sample ratios was not normal, however, as was assumed a process of this type would produce. On the other hand, the failure of the regression analysis to identify any significant variables which would explain these variations would tend to re-enforce the assumption that the fluctuations were indeed of a random nature.To sum it up in one paragraph, aside from a few extreme cases, the assessing process appears to give estimates which are more consistent than would be expected under the assumption that any errors would be of a random nature, but the regression analysis was unable to isolate any particular socioeconomic characteristics which would explain the variation which was present.Financial support for this research project was furnished by the University of Tulsa.