何时才能让“带病”施工远离建筑工地

“带病”施工再次酿成惨剧。3月19日中午,西宁市商业巷一个建筑工地违规操作,施工过程中突然发生深基坑边坡大面积坍塌事故,8名正在作业的农民工全部遇难。     

浅议公路工程项目施工技术与安全

技术管理是项目在施工过程中的一项重要工作,如何进行技术管理,很多资料中都有叙述,但大都是从编制技术文件、拟定方案、方案报批或开专家评审会、技术交底、技术创新、技术总结等方面进行管理。而施工技术与施工安全有着必然的联系,由于施工技术管理不到位造成的事故时有发生。笔者将从施工技术与安全的角度介绍技术管理的内容。     

国外交通安全管理多措并举

交通安全管理是一个系统工程。为进一步降低交通事故率,世界各国都在探索建立一套可在大范围、全方位发挥作用的交通综合管理系统,提高各种道路的利用效率,增加交通安全性,最终达到人、车、路的和谐一体。已有的经验证明,一国的经济高速发展期,也往往是交通安全状况严重恶化的危险期。我国目前严峻的交通安全形势也印证了这一点。     

声音

“咱们都是家里的顶梁桩,上有老下有小,出个事昨办？一个班里的工友就是亲兄弟,在井下,我们不仅要自保,更要互保、联保,在安全生产上如果班长不严、不管、不问,那才是对大家不负责任。” 这是中国平煤神马能源化工集团七星公司开拓四队班长白国周在生产过程中经常对工友说的话。白国周不断探索班组安全管理的新方法,并坚持把这些管理方法运用到生产实践中去,创造了22年没有出现任何生产安全事故的奇迹。     

五策并举 防微杜渐——三明市安全生产的对策分析

安全生产工作是一切工作的重要保证,是一项系统工程.近年来,三明市各级各部门按照国家、省、市的一系列工作部署和要求,坚持"安全第一,预防为主,综合治理"的方针,切实解决安全生产工作中碰到的机构编制、人员、经费、设备和相关政策等重大问题,投入了大量的人力、物力和财力,全力加强安全生产工作,全市呈现出安全生产形势总体稳定、趋于好转的良好态势.但也存在着一些问题,为了不断改善我市安全生产状况,严密防范重特大安全事故的发生,促进全市安全生产形势持续保持稳定好转,笔者提出以下五点对策……     

二氧化碳变碳有望成真

英国《新科学》杂志日前载文介绍了德国化学家的最新发现,科研人员通过使用一种新型催化剂,以实现从二氧化碳中分离碳的目的,也就是模仿植物光合作用的过程,实现碳的循环利用.     

Transformations of particles, metal elements and natural organic matter in different water treatment processes

Characterizing natural organic matter （NOM）, particles and elements in different water treatment processes can give a useful information to optimize water treatment operations. In this article, transformations of particles, metal elements and NOM in a pilot-scale water treatment plant were investigated by laser light granularity system, particle counter, glass-fiber membrane filtration, inductively coupled plasma-optical emission spectroscopy, ultra filtration and resin absorbents fractionation. The results showed that particles, NOM and trihalomethane formation precursors were removed synergistically by sequential treatment of different processes. Preozonation markedly changed the polarity and molecular weight of NOM, and it could be conducive to the following coagulation process through destabilizing particles and colloids; mid-ozonation enhanced the subsequent granular activated carbon （GAC） filtration process by decreasing molecular weight of organic matters. Coagulation-flotation and GAC were more efficient in removing fixed suspended solids and larger particles; while sand-filtration was more efficient in removing volatile suspended solids and smaller particles. Flotation performed better than sedimentation in terms of particle and NOM removal. The type of coagulant could greatly affect the performance of coagulation-flotation. Pre-hydrolyzed composite coagulant （HPAC） was superior to FeCl3 concerning the removals of hydrophobic dissolved organic carbon and volatile suspended solids. The leakages of flocs from sand-filtration and microorganisms from GAC should be mitigated to ensure the reliability of the whole treatment system.     

Denitrification potential enhancement by addition of external carbon sources in a pre-denitrification process

The aim of this study is to investigate the denitrification potential enhancement by addition of external carbon sources and to estimate the denitrification potential for the predenitrification system using nitrate utilization rate （NUR） batch tests. It is shown that the denitrification potential can be substantially increased with the addition of three external carbon sources, i.e. methanol, ethanol, and acetate, and the denitrification rates of ethanol, acetate, and methanol reached up to 9.6, 12, and 3.2 mgN/（g VSS.h）, respectively, while that of starch wastewater was only 0.74 mgN/（g VSS,h）. By comparison, ethanol was found to be the best external carbon source. NUR batch tests with starch wastewater and waste ethanol were carried out. The denitfification potential increased from 5.6 to 16.5 mg NO3-N/L owing to waste ethanol addition. By means of NUR tests, the wastewater characteristics and kinetic parameters can be estimated, which are used to determine the denitrification potential of wastewater, to calculate the denitrification potential of the plant and to predict the nitrate effluent quality, as well as provide information for developing carbon dosage control strategy.     

亲身体验——环境教育的有效途径

教育学意义上的“体验”既是一种活动过程,也是一种活动结果。作为一种活动过程,指学生亲身经历某事,并获得相应的认识和情感;作为一种活动结果,指学生从其亲历中获得认识结果和情感体验。因此,学校和老师要创设学生亲身体验的环境和机会让学生在‘做中学”,在实践中体验。这种体验不单指用耳朵听,用手去做,更强调用脑想,用心去体会,要调动全部感官系统和思维机器,全身心地投入,从而达到行为和认知的统一。     

哈马碧滨水新城——可持续发展社区的典范

瑞典首都斯德哥尔摩曾经闯入申办2004年第二十五届奥运会的最后一轮筛选,遗憾的是未能胜过雅典而取得主办权。但这个城市却在申办过程中意外地打造了一个可持续发展的社区——哈马碧滨水新城。它成为人们津津乐道的一处靓丽风景。