Do we understand trends in atmospheric sulfur species?

Anomalies appear to exist in our understanding of atmospheric sulfur compounds, specifically as evidenced in the time trends of the different chemical forms of these compounds. Trends determined at a number of locations by several different groups seem to indicate that, responding to emission reductions across North America, the concentration of SO2 in the atmosphere is declining more rapidly than that of aerosol SO4(2-). A number of possible reasons for this discrepancy are examined, but it is not possible to provide a definitive answer at this stage. The intent is to stimulate debate, because shortcomings in our understanding of the processes involved could have profound implications for the credibility of abatement strategies and policies for both acid deposition and fine particulate matter (PM).     

Evaluation of physico-chemical and structural properties of biochar produced from pyrolysis of urban biowaste

Journal of Material Cycles and Waste Management - Understanding proper utilization and evaluation of biowaste materials in any metropolitan city across the world is crucial with respect to...     

稀土湿法冶炼废水处理与资源化研究

对某稀土湿法冶炼工艺进行了以清洁生产为核心的技改方案研究,在清洁工艺设计的基础上,通过工艺原理分析和试验,说明其革新工艺的经济有效性;从酸浸废液中年回收硫酸亚铁３０００ｔ,从碱转废液中年回收硫酸钠３０００ｔ;从废水回收冰晶石,氟回收８６％;     

不同桩芯微型桩抗弯承载力试验研究∗

为研究不同桩芯微型桩在隧道洞口不良地质边坡中的治理效果,拟对钢筋-混凝土、工字钢-混凝土、钢管-钢筋-混凝土、钢管-工字钢-混凝土微型桩开展抗弯极限承载力试验。研究表明,工字钢-混凝土微型桩相比钢筋-混凝土微型桩极限抗弯承载力不仅大幅度提升,其抵抗位移变形的能力也有所增加。钢筋-混凝土微型桩和工字钢-混凝土微型桩桩径由140 mm变化到203 mm,韧性分别提高25%、50%,抗弯承载力分别提高89%、91%。钢管微型桩的韧度、极限抗弯承载力都明显强于裸露混凝土桩,即使变形已非常显著,仍能继续受力。钢管-钢筋-混凝土微型桩、钢管-工字钢-混凝土微型桩桩径由140 mm变化到203 mm,抗弯承载力分别提高近256%、265%。     

我国生态保护与建设支出账户框架构建研究

生态保护与建设是我国生态文明建设的重要任务,生态保护与建设支出账户核算是环境经济核算的重要内容,但我国目前尚未开展系统的生态保护与建设支出核算。本文首先梳理了生态保护与建设支出核算的国际经验,指出我国生态保护与建设支出账户核算面临统计口径不完善、统计体系尚未建立、统计主体和对象仍不完整、统计数据呈部门化和分散化等问题。在此基础上,本文从生态保护与建设支出主体、支出分类、支出资金来源等方面初步构建了支出账户核算体系,并以2013年为例进行了初步估算。结果表明,我国财政资金用于生态保护与建设的支出总量不足,仅占当年GDP的0.25%。为推动生态保护与建设支出账户核算工作,建议应从预算科目、统计口径、统计主体、统计对象等方面不断完善生态保护与建设统计体系,加快推进生态保护与建设支出账户的构建与核算,并争取尽快纳入国民经济核算体系,以推进生态文明体制改革与制度建设的进程,促进我国生态保护与经济社会的协调发展。     

草莓蚜虫防治用药对蜜蜂的急性毒性与风险评价

为明确草莓蚜虫防治用药对蜜蜂的影响,按照《化学农药环境安全评价试验准则》和《化学品测试方法》要求测定了20%啶虫脒SP、10%氟啶虫酰胺WG和22%氟啶虫胺腈SC对意大利蜜蜂(Apis mellifera L.)的急性毒性,并采用危害商值(HQ)法进行了风险评价。急性毒性结果显示:20%啶虫脒SP、10%氟啶虫酰胺WG和22%氟啶虫胺腈SC对蜜蜂的急性经口毒性试验结果(48 h-LD50值)分别为4.47μg a.i.·蜂~(-1)、11.2μg a.i.·蜂~(-1)和0.0601μg a.i.·蜂~(-1),对蜜蜂的急性接触毒性试验结果(48 hLD50值)分别为11.0μg a.i.·蜂~(-1)、13.9μg a.i.·蜂~(-1)和0.643μg a.i.·蜂~(-1)。按《化学农药环境安全评价试验准则》中毒性等级划分标准,20%啶虫脒SP、10%氟啶虫酰胺WG和22%氟啶虫胺腈SC对蜜蜂的毒性等级分别为中毒、低毒和高毒。风险评价结果表明,22%氟啶虫胺腈SC对蜜蜂存在中等风险(HQ值为1 622),20%啶虫脒SP和10%氟啶虫酰胺WG对蜜蜂的风险为低风险,其HQ值分别为40.3和6.70。因此,草莓生产中可优先选用10%氟啶虫酰胺WG来防治蚜虫,20%啶虫脒SP次之。而使用22%氟啶虫胺腈SC时,应注意采取措施降低其对蜜蜂的毒性风险,以免造成危害。     

Isotopic evidences for provenance of East Asian Dust

We have systematically collected samples in the possible source regions (the deserts and sandy lands of North China, northeastern past of the Tibetan Plateau, Chinese Loess Plateau and southern part of Mongolia) of the East Asian dust. Based on Nd–Sr isotopic ranges, the source regions can be divided into four isotopic regions: Region A1: the Gurbantunggut Desert in Junggar basin and Hunlun Buir sandy land in northeastern China; Region A2: the Hunshandake sandy land, Horqin sandy land and southern part of Mongolia; Region B: the Taklimakan Desert in Tarim basin, northeastern past of the Tibetan Plateau, Chinese Loess Plateau, Badain Jaran Desert and Tengger Desert in Alashan Plateau; Region C: the Hobq Desert and Mu Us Desert in the Ordos Plateau. Through comparison of Nd–Sr isotopes, it can be inferred that the sediments of the north-central Pacific and dust particles in the Greenland ice cores are mainly derived from Region B. Dusts of East Asian dust storm are derived mostly from Region B also, and less from Region A2. The materials of dust storm at Beijing area in April 2006, originated largely from the Hobq Desert and Mu Us Desert in the Ordos Plateau. The floating dust at Beijing area in April 2006, is the mixing of dust of distant deserts and local dust at Beijing area. Loess of the Chinese Loess Plateau may largely originate from Region B.