长江中游城市群能源效率评价研究

提高能源效率、促进低碳经济转型是当前长江中游城市群区域协同发展和新型城镇化建设的重点和难点。基于共同前沿(Meta-frontier)理论,利用数据包络分析方法构建非参数前沿,并将SO2排放量这一非期望产出纳入DEA模型中,比较分析了2005—2014年长江中游城市群全要素能源效率的区域差异,采用"技术缺口比率"衡量长江中游城市群三大区域之间能源利用的技术差距,并在此基础上研究了能源非效率的分解以及对真实的能源强度和潜在的能源强度进行了相关分析。研究结果表明:1当前长江中游城市群全要素能源效率整体水平偏低,但地区差异并不显著。2三大区域之间的能源技术差距不是很大。3技术缺口和管理等因素对不同区域能源非效率的作用不同。4真实的能源强度和潜在的能源强度都具有一定下降的趋势,而且两者之间的差距逐渐缩小。最后根据分析结果得出一些结论和启示,如制定区域节能战略时坚持"求同存异"的原则,加快技术进步,积极进行能源技术创新,不断提高管理水平等。同时,政府应加大对长江中游城市群的政策倾斜力度,这样才能充分挖掘长江中游城市群的节能减排潜力,这对提升中国区域能源效率的整体水平以及促进绿色经济转型具有重大意义。     

负载型氧化铁对高毒气体PH3的催化分解

采用沉积-沉淀法制备了碳纳米管(CNTs)和二氧化硅(SiO2)负载的纳米Fe2O3催化剂,将其应用于高毒气体PH3分解反应.通过XRD,TEM,XPS,BET等一系列检测手段,对制备样品的相结构、形貌、组分和比表面积进行了表征.研究结果表明,在PH3催化分解反应过程,极少量的产物P迁移至Fe2O3中,形成金属磷化物FeP作为反应的活性相.与Fe2 O3/SiO2相比,Fe2O3/CNTs显示了较高的催化性能.在440℃反应温度下,Fe2O3/CNTs对PH3分解率达到99.8％.CNTs作为催化剂载体的优秀性能可归因于CNTs良好的导电性能和活性组分在其上的高度分散.     

重庆城区不同粒径颗粒物元素组分研究及来源识别

为研究重庆市大气颗粒物的污染特征及其来源,于2010年3—10月在主城区分别采集PM_1.0、PM_2.5和PM₁₀3种粒径的颗粒物样品,利用XRF分析其中的26种元素浓度。结果表明,重庆市主城区S元素在各粒径中含量都较高,细粒子中K的含量较高,粗粒子中Si、Ca和Fe的浓度较大。富集因子分析表明,主城区Cd、S、Se等污染元素的富集系数较大,且粒径越小,富集现象越明显。利用因子分析得出土壤风沙、扬尘、燃煤的燃烧、机动车燃油产生的尾气排放、生物质燃烧排放是重庆市颗粒物污染的主要来源。     

Cs,Co and K uptake by lettuce plants in two distributions of soil contamination

¹³⁷Cs and ⁶⁰Co, two of the radionuclides more representative of discharges from nuclear facilities, are of interest for radiological protections because of their great mobility in biosphere and affinity with biological systems. The aim of the present work is the investigation of the possible influence of the vertical distribution of ¹³⁷Cs and ⁶⁰Co in soil upon their uptake by lettuce as function of plant's growth. An experiment ad hoc has been carried out in field conditions. The results show that (i) the transfer of ¹³⁷Cs and ⁶⁰Co from soil to lettuce is independent by their distribution in soil, (ii) the soil–plant transfer factors of ¹³⁷Cs and ⁶⁰Co show a similar trend vs. growth stage, (iii) the ⁴⁰K transfer factor trend is different from those of anthropogenic radionuclides, and (iv) ¹³⁷Cs and ⁶⁰Co specific activities are about 1 Bq/kg, in the mature vegetable with soil activity from 9 to 21 kBq/m².     

Interlaboratory comparisons in EMF survey measurements

This article presents methods and results of interlaboratory comparison in the electromagnetic field (EMF) survey measurements performed by Electromagnetic Environment Protection Laboratory. Based on the results, the author analyzed factors affecting the precision of EMF measurements, in particular—difficult to estimate—the “human factor”. In practice, the human factor has never been taken into account in the EMF measurements accuracy estimations budget, and the author estimate the importance of this factor that may include even up to half of the total uncertainty of measurements. Taking into account all factors depredating the accuracy of measurements, the uncertainty of the survey EMF measurements was estimated at the level of 2–4 dB.     

Nitrous oxide emissions from an intensively managed greenhouse vegetable cropping system in Northern China

Nitrous oxide (N₂O) emissions from a typical greenhouse vegetable system in Northern China were measured from February 2004 to January 2006 using a close chamber method. Four nitrogen management levels (NN, MN, CN, and SN) were used. N₂O emissions occurred intermittently in the growing season, strongly correlating with N fertilization and irrigation. No peak emissions were observed after fertilization in the late Autumn season due to low soil temperature. 57-94% of the seasonal N₂O emissions came from the initial growth stage, corresponding to the rewetting process in the soil. The annual N₂O emissions ranged from 2.6 to 8.8 kg N ha⁻¹ yr⁻¹, accounting for 0.27-0.30% of the annual nitrogen input. Compared with conventional N management, site-specific N management reduced N fertilization rate by 69% in 2004 and by 76% in 2005, and consequently reduced N₂O emissions by 51% in 2004 and 27% in 2005, respectively.     

昆山市22年来耕地流失研究

以昆山市1985～2006年共22a间的耕地面积变化及与之相关的总户籍人口、非农业人口、第一产业从业人口、地区生产总值、人均地区生产总值、第一产业生产总值、第二产业生产总值、粮食总产量和社会固定资产投资等9种社会经济指标为研究对象,采用变化率相关分析、主成分阶段分类等新方法对目前耕地流失研究中常用的相关分析、主成分分析等数学方法进行改进。研究结果表明:(1)新方法在耕地流失主要驱动因素分析和阶段划分方面具有独特的优势,同时能够通过回归方程的验证,所得结论可信度较高;(2)昆山市耕地流失的首要驱动因素为以人均地区生产总值为代表的社会经济水平的提高,同时人口增长和第二产业的发展加剧了耕地流失状况;(3)昆山市耕地流失按照所受压力对农业发展的影响可以分为3个阶段,分别为1985～1994年的未限制阶段、1995～1997年制约平衡阶段和1998～2006年限制阻碍阶段。     

木工机械引发事故原因与预防措施

介绍木制品加工过程中的危险、有害因素，分析木工机械引发事故的原因，提出一些预防事故发生的措施．     

自然环境因素对铝合金大气腐蚀的影响性研究

目的 研究铝合金大气腐蚀受自然环境因素的影响性，探索环境因素对铝合金腐蚀的影响规律。方法 采用多层感知器神经网络分析环境因素对7种铝合金平均腐蚀速率的影响。结果 确定了影响铝合金腐蚀损伤的重要因素为SO2沉积率、Cl^–沉积率、NOx沉积率；辅要因素为年降雨量、年雾露时数、相对湿度、年日照时数、温度、铝合金成分；次要因素为年累积降水时数、雨水pH值。结论 基于多层感知器神经网络分析有效展现了环境因素对平均腐蚀速率的影响性。     

Triclosan in Fresh Water Fish Gibelion Catla from the Kaveri River,India, and Its Consumption Risk Assessment

Triclosan is a common antimicrobial agent that is found in significant levels in the aquatic environment and may elicit effects on aquatic organisms through unexpected modes of action. In this study, triclosan was quantified in fish from the Kaveri River, India, by using the gas chromatography and mass spectrometry technique and it was found in the range of 0.73–50 ng/g wet weight (ww). The mean bioaccumulation factor based on water (BAF_w 820) and sediment (BAF_s 2.12) in the Kaveri River showed that triclosan is accumulative in fish, and reflects its feeding behavior. The bioaccumulation indicates triclosan's persistence or prevalence throughout the river stretch. Human risk assessment through dietary intake demonstrated that the triclosan exposure is five orders of magnitude lower than the acceptable daily intake (50 μg/kg bw) and US EPA reference dose (300 μg/kg bw/day). This investigation is the first to report the bioaccumulation of triclosan in freshwater fish from India. Further, the results indicate that this fish acts as a biomarker of exposure for triclosan and thus shall be used to report triclosan pollution in the future.