Air pollution and climate change are two important threats facing in our planet and are tightly linked to carbonaceous components in the atmosphere. A better understanding of the emission sources and environmental fate/sink of carbonaceous components is critical for improving our knowledge of the global carbon cycle and mitigating the negative environmental impacts of air pollution and climate change on human well-being. Radiocarbon (14C), which is decayed completely in fossil fuel (e.g. coal and petroleum), is an ideal tool for quantifying the carbon flow in various carbon reservoirs. This study reviews the current knowledge of 14C in organic carbon (OC), elemental carbon (EC), individual organic compounds, methane (CH4), carbon dioxide (CO2), annual plants, and tree rings. The impacts of fossil and non-fossil sources on the atmosphere can be quantified by measuring 14C. We also report on the influence of nuclear power plants and sea-air gas exchange on the abundance of 14C in the atmosphere. The increasing fossil fuel emissions indicated by the depletion of 14CO2 under IPCC RCP scenarios, support the urgent need to devise ambitious strategies of reducing carbonaceous components to achieve sustainable development on Earth. This review summarizes the challenges and perspectives of 14C studies of the atmosphere.

文章从知识结构、实践能力、创新教育等几方面考虑,突破传统的实验教学观念,探索"三位一体"实验教学体系的建设,对实验课程进行了全面整合与重建,提升了人才培养质量,使得培养对象更加适应新时代背景下的创新型人才需求.

利用STAPLEX大流量分级采样器于2014年8-12月采集拉萨市城区大气颗粒物84个样品,测定不同粒径上有机碳(OC)和元素碳(EC)的质量浓度,定性分析二次有机碳(SOC),基于碳质组分和14C值得到其来源.结果 表明,不同粒径的OC质量浓度呈双峰分布,较高峰出现在＜0.49 μm粒径段,次高峰出现在1.5-3.0 μm粒径段(8-9月)和3.0-7.2μm粒径段(11-12月);EC主要分布在＜0.49μm粒径段.OC/EC比值为4.15-33.80,表明拉萨大气颗粒物存在二次有机碳.研究表明,拉萨市碳质颗粒物的主要污染源是燃煤、机动车尾气、生物质燃烧和地面扬尘、生物质燃烧和地面扬尘是OC的主要来源,燃煤和机动车尾气则是EC的主要来源.

To understand the physical and chemical characteristics, particle size distribution and sources of size-separated aerosols in Lhasa, which is located on the Tibetan Plateau (TP), six sizes of aerosol samples were collected in Lhasa in 2014. Ca2+, NH4+, NO3-, SO42- and Cl- were the dominant ions. The ratio of cation equivalents (CE) to anion equivalents (AE) for each particle size segment indicated that the atmospheric aerosols in Lhasa were alkaline. SO42- and NO3- could be neutralized by Ca2+, but could not be neutralized by NH4+, according to the [NH4+]/[NO3- + SO42-] and [Ca2+]/[NO3- + SO42-] ratios. Mobile sources were dominant in PM0.95-1.5, PM1.5-3 and PM3-7.2, while stationary sources were dominant in the other three size fractions according to the [NO3-]/[SO42-] ratios. The particle size distribution of all water-soluble ions during monsoon and non-monsoon periods was characterized by a bimodal distribution due to the different sources and formation mechanisms, and it was revealed that different ions had different sources in different seasons and different particle size segments by combining particle size distribution with correlation analysis. Source analysis of aerosols in Lhasa was performed using the Principal component analysis (PCA) for the first time, which revealed that combustion sources, motor vehicle exhaust, photochemical reaction sources and various types of dust were the main sources of Lhasa aerosols. Furthermore, Lhasa's air quality was also affected by long-distance transmission, expressed as pollutants from South Asia and West Asia, which were transmitted to Lhasa according to backward trajectory analysis.

We present dual carbon isotope constrained (δ13C and Δ14C) source apportionment of organic carbon and elemental carbon in fine particulate matter (PM2.5) for five districts of Shanghai during the winter of 2013. The results show that spatial variations of the three source (biomass, liquid fossil fuel, and coal) apportionment of carbonaceous aerosol among different districts were evident. Overall, coal combustion, liquid fossil fuel combustion and biomass burning are the most important carbonaceous aerosols source in Pudong, Xuhui and Chongming, respectively. The results suggest that environmental protection policies should vary according to the functional areas of different sources in the same city.

In this paper, we intensively collected atmospheric particulate matter (PM) with different diameters (size ranges: <0.49, 0.49–0.95, 0.95–1.5, 1.5–3.0, 3.0–7.2, and >7.2 μm) in Lhasa during the monsoon and non-monsoon seasons. The results clearly showed that the concentrations of PM, organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) during the non-monsoon season were much higher than the concentrations during the monsoon season. During the monsoon season, a bimodal size distribution of the OC and WSOC, which were at <0.49 μm and >7.2 μm, respectively, and a unimodal size distribution at <0.49 μm for the EC were observed. However, during the non-monsoon season, there was a trimodal size distribution of the OC and WSOC (<0.49 μm, 1.5–3.0 μm, and >7.2 μm), and a unimodal size distribution of the EC (<0.49 μm). Possible sources of the carbonaceous components were revealed by combining the particle size distribution and the correlation analysis. OC, EC, and WSOC were likely from the photochemical transformation of biogenic and anthropogenic VOC, and the incomplete combustion of biomass burning and fossil fuels at <0.49 μm, whilst they were also likely to be from various types of dust and biogenic aerosols at >7.2 μm. OC and WSOC at 1.5–3.0 μm were likely to have been from the burning of yak dung and photochemical formation. The above results may draw attention in the public and scientific communities to the issues of air quality in the Tibetan Plateau.

A novel method has been improved for analyzing atmospheric pollutant metals (Be, Mn, Fe, Co, Ni, Cu, Zn, Se, Sr, Cd, and Pb) by laser ablation inductively coupled plasma mass spectrometry. In this method, solid standards are prepared by depositing droplets of aqueous standard solutions on the surface of a membrane filter, which is the same type as used for collecting atmospheric pollutant metals. Laser parameters were optimized, and ablation behaviors of the filter discs were studied. The mode of radial line scans across the filter disc was a representative ablation strategy and can avoid error from the inhomogeneous filter standards and marginal effect of the filter disc. Pt, as the internal standard, greatly improved the correlation coefficient of the calibration curve. The developed method provides low detection limits, from 0.01 ng m− 3 for Be and Co to 1.92 ng m− 3 for Fe. It was successfully applied for the determination of atmospheric pollutant metals collected in Lhasa, China. The analytical results showed good agreement with those obtained by conventional liquid analysis. In contrast to the conventional acid digestion procedure, the novel method not only greatly reduces sample preparation and shortens the analysis time but also provides a possible means for studying the spatial distribution of atmospheric filter samples.

To estimate the sources of carbonaceous particulate matter, 14C and biomass-burning marker (levoglucosan) were measured in the form of organic carbon (OC) and elemental carbon (EC) in PM2.5 that was collected in five different functional districts of Shanghai during winter 2013. Spatial variations of the contemporary proportion among different districts were evident. The results of levoglucosan in Xujiahui (XH) and Chongming (CM) agreed well with those of 14C. The results indicate that environmental protection policies should vary for functional districts within the same city to account for their different sources of emissions.

This paper proposes an outline for the reform of the professional training program in the nuclear field .It is pointed out that the primary task of the training program is to establish students ’ awareness of the importance of practice ,to increase their interests ,and to conduct teaching program which not only focuses on students’ interests ,but also is adjustable to their different levels of capabilities .This paper mainly introduces the specific measures in the reform of professional training program in the nuclear field .It is believed that the ultimate goal of improving the quality of professional training in the nuclear field can be reached by establishing a more complete ,more scientific ,and more pragmatic personnel training curriculum .

在福岛核事故发生之前，中国曾计划到2015年使核电装机容量扩大到4000万千瓦，到2020年达到8000万千瓦[1]。而目前中国正在服役的核反应堆为15个，总装机容量不到2000万千瓦，这是因为日本“福岛”核电事故后，各国核电发展计划都受到影响，德国甚至完全放弃了核电发展计划，中国开发核电建设的势头也一度降温。不过，2012年12月24日召开的国务院常务会议，讨论通过《能源发展“十二五”规划》，再次讨论并通过《核电安全规划(2011-2020年)》和《核电中长期发展规划(2011-2020年)》。会议对当前和今后一个时期的核电建设做出部署：(一)稳妥恢复正常建设。合理把握建设节奏，稳步有序推进。(二)科学布局项目。“十二五”时期只在沿海安排少数经过充分论证的核电项目厂址，不安排内陆核电项目。(三)提高准入门槛。按照全球最高安全要求新建核电项目。新建核电机组必须符合三代安全标准。这意味着我国核电及相关技术产业将继续快速发展，且对核电及相关的核专业人才的需求更大，专业技术要求更高[2]。可是，近20年的核工业发展的低谷时期，造成了核专业人才的流失，国家在核专业方面的人才储备很少。2004-2005年，国家国防科工局根据当时核电发展形势和核工业发展规划，对我国核专业人才的需求情况进行了问卷调查和预测，得到的结果是：到2020年，全国需要核工程专业本科以上的人才大约6600人，基础科学及核技术应用专业大约5000人。按这个预测结果，2015年前，全国每年需要培养核专业学生1200名左右，包括：核反应堆工程专业学生330人、核化工与核燃料工程专业学生350人、辐射防护与环境保护专业学生130人、核物理等基础学科专业学生90人、核地质与铀矿冶专业学生140人。而我国高校核专业人才培养的实际情况与这个要求相差很大。“十一五”到目前的“十二五”末期，清华大学、哈尔滨工程大学、四川大学、南华大学、成都理工大学等高校大量增加了核专业人才培养的数量，但还是不能满足中核集团、广核集团等单位对核专业人才的需求，特别是对质量方面的需求。这意味着核专业人才培养的高校必须面向需求、重视人才培养的质量，也就要求核专业技术人才培养的单位建立更完整、更科学和更实效的人才培养课程体系。

The accurate measurement of 220Rn is important for dosimetry evaluation of natural radiation exposure.The detection efficiencies of normal scintillation cell to different energy α particles decayed from 222Rn,220Rn and their daughters are different for the large volume of normal scintillation cell.It was proposed that the range of α particles with minimum energy decayed from 222Rn could be longer than the longest distance between any two points in the scintillation cell by reducing the air pressure of scintillation cell.Thus,the detection efficiencies of the low-pressure scintillation cell to α particles decayed from 222Rn,220Rn and their daughters are same.The detection efficiency of low-pressure scintillation cell to α particles can be obtained by standard radon chamber,and then the 220Rn concentration reference value can be determined by low-pressure scintillation cell.

科技的进步和网络的发展,使学习方式不断创新和多样化,网络课程作为一项重要的教学软件在当代学生的教育中日益普及,并不断丰满。本文以《电离辐射剂量与防护》课程为核心,在南华大学数字化教学中心实现了该课程的网络课程建设。在此过程中,发现了当代网络课程建设存在的主要问题,提出了加强和改进网络课程建设的对策。

Large amount of radon is emitted to the atmosphere in uranium mining,which have a certain degree of radioactive pollution to the environment. Through the establishment of the radon diffusion model,the article carried out reasonable theoretical estimates for calculating the degree and range of radon pollution caused by uranium mining,and discussed how to select the appropriate height of the exhaust vents and the key protection area within the corresponding neighborhood under different natural conditions. The results show that the radon pollution level is not high around the exhaust vents when the height of the exhaust vents is 20 meters higher than the surrounding environment. However,given the influences of economy,mining terrain,ventilation conditions and other factors,the analysis and design should be optimized for selecting location of exhaust vents and the corresponding key protection areas.

With the progress of social and economic development, social demand for talents is more and more high. However, class is the core of university education, which has many problems such as halfheartedness and absence of the students in class, vapidity for teaching and interaction between the students and teachers, poor teaching effect, and so on. Based on Rogers's creation view we analyze problems of nuclear course class in colleges, study the importance of the curriculum reform, and effective measures for teaching, how to improve the students' interest in learning, how to training comprehensive talent who can meet the social needs in the classroom.

To effectively reduce urban carbon emissions and verify the effectiveness of currently project for urban carbon emission reduction,quantitative estimation sources of urban atmospheric CO2 correctly is necessary.Since little fractionation of carbon isotope exists in the transportation from pollution sources to the receptor,the carbon isotope composition can be used for source apportionment.In the present study,a method was established to quantitatively estimate the source of urban atmospheric CO2 by the carbon isotope composition.Both diurnal and height variations of concentrations of CO2 derived from biomass,vehicle exhaust and coal burning were further determined for atmospheric CO2 in Jiading district of Shanghai.Biomass-derived CO2 accounts for the largest portion of atmospheric CO2.The concentrations of CO2 derived from the coal burning are larger in the night-time（00：00,04：00 and 20：00） than in the daytime（08：00,12：00 and 16：00）,and increase with the increase of height.Those derived from the vehicle exhaust decrease with the height increase.The diurnal and height variations of sources reflect the emission and transport characteristics of atmospheric CO2 in Jiading district of Shanghai.

The air quality and pollution characteristics inside tunnels have been receiving more and more attention.Mass concentrations of airborne fine particles with different sizes(cut-off diameter:0.03,0.06,0.108,0.17,0.26,0.40,0.65,1.0,1.6,and 2.5 μm) were compared between inside a tunnel and the ambient atmospheric environment.In addition,the mass concentrations of 12 trace elements(S,K,Ca,Ti,Mn,Fe,Zn,Pb,Al,Si,Cu,and V) in the fine particles were investigated.The results showed that both number and mass concentrations of fine particles with different sizes reached obvious peaks during rush hour inside the tunnel.Moreover,the number concentrations of particles with size range of 0.108 μm inside the tunnel were 15.2 times those in the ambient atmospheric environment.Mass concentrations of particles with size range of 2.5 μm reached 40.0 times those in the atmospheric environment.The trace elements Si,Ca,Fe,Al,Ti,Zn,Mn,Cu and V in the fine particles showed larger mass concentrations inside the tunnel,while S,Pb,Zn and K showed lower mass concentrations.Mass concentrations of the crustal elements such as Si,Ca,Fe,Al and Ti accounted for approximately 87% of the total elemental mass concentration of the fine particles inside the tunnel,indicating that soil dust is still the main source of fine particles in the tunnel.

Number concentrations of particulate matters with different diameters(mass medium diameter: 0.03,0.06,0.11,0.17,0.26,0.40,0.65,1.00,1.60,2.50,4.40,6.80 μm) were on-line monitored using an ELPI(electrical low pressure impactor) during 2009 Spring Festival in Jiading District,a suburb area in Shanghai.Several chemical components including 17 elements,10 ions,organic and elemental carbon in particulate matters with different diameters(0.49,0.49—0.95,0.95—1.50,1.50—3.00,3.00—7.20,7.20 μm) were further determined.These particulate matters were collected on both the Spring Festival and ordinary days on the same sampling site.Experimental results showed that the influence of Festival Spring on the number concentrations was mainly on the particulate matters with size range of 0.11— 1.60 μm.If the particulate matters are divided into fine(≤3.00 μm) and coarse(3.00 μm) ones by the diameter of 3.00 μm,it can be seen that the trace elements of Na,As and Pb in fine particulates were greatly affected by the Spring Festival and such effects appeared mainly in the particulate matter with size of 0.49 μm.The trace elements of Ni,Co in coarse particles with size of 7.20 μm were affected by the Spring Festival while Ca,V,Mn,Fe,Zn,Se didn′t show significant effect of the Spring Festival.F-,SO2-4,NH+4,K+,Mg2+ in both fine and coarse particulates were influenced by the Spring Festival.K+ and Mg2+ were influenced seriously in fine particles,and Cl-,NO-3,Na+,NO-2 and Ca2+ in coarse particles were influenced.The OC and EC were much higher in TSP during the Spring Festival than those on ordinary days,and the increases mainly occurred in the fine particles.

The concentration of airborne particles (0.03–4.4 µm) in clear and haze days in Shanghai was online investigated by ELPI (electrical low pressure impactor). The concentration of typical elements (K, Ca, Ti, Mn, Cr, Ni, Cu, S, Cl, Zn, As, Pb, Fe) was measured by synchrotron radiation X-ray fluorescence. In this work, Fe was used as the reference element to demonstrate the enrichment of other elements. Experimental results show that, the concentration of airborne particles appeared bi-modal in haze days while appeared single modal in clear days. Also, the particle number concentration showed more remarkable peaks in size segregated particles (0.07–0.3 µm) in haze days than in clear days. Ca, Ti, Cl, Mn, Cr, Zn, As, Pb exhibited single modal in clear days and exhibited bi-modal in haze days; K exhibited single modal in clear and haze days; Cu, S exhibited bimodal in clear and haze days; Ni exhibited bi-modal in clear days and exhibited tri-modal in haze days; Cu, S, Ni showed prominent differences in clear and haze days. For the reason that the enrichment factors of K, Ca, Ti, Mn, Cr were less than 10, they were mainly from natural sources. The enrichment factors of Cl, Pb, As, Ni, Cu, S, Zn were much larger than 10 in clear and haze days, and also the enrichment factors of Ni, Cu, S, Zn were obviously larger in haze days than in clear days.

Atmospheric visibility becomes an important indicator of regional atmospheric environment study,and the effects of atmospheric particles on visibility are significantly different because of their different sizes.The daily mass and number concentrations for atmospheric particles of different sizes were monitored from November 2008 to January 2009 in Jiading district of Shanghai.The visibility was also collected synchronously in the same region.Correlations of the mass concentration for atmospheric particles of different sizes with horizontal visibility and extinction coefficient of particles were analyzed.The results indicate that the effects of atmospheric particles with 0.40 μm and 0.65 μm medium diameters on horizontal visibility are significant,so is with 0.17 μm,0.26 μm,0.40 μm and 0.65 μm medium diameters on extinction coefficient.The distributions of correlation coefficients are consistent with size distributions of five components(SO2-4,NO-3,NH+4,OC and EC) of atmospheric particles,which suggests that five components may be the important influencing factors of extinction coefficient.

The concentration of airborne particles (0.03–4.4 µm) in clear and haze days in Shanghai was online investigated by ELPI (electrical low pressure impactor). The concentration of typical elements (K, Ca, Ti, Mn, Cr, Ni, Cu, S, Cl, Zn, As, Pb, Fe) was measured by synchrotron radiation X-ray fluorescence. In this work, Fe was used as the reference element to demonstrate the enrichment of other elements. Experimental results show that, the concentration of airborne particles appeared bi-modal in haze days while appeared single modal in clear days. Also, the particle number concentration showed more remarkable peaks in size segregated particles (0.07–0.3 µm) in haze days than in clear days. Ca, Ti, Cl, Mn, Cr, Zn, As, Pb exhibited single modal in clear days and exhibited bi-modal in haze days; K exhibited single modal in clear and haze days; Cu, S exhibited bimodal in clear and haze days; Ni exhibited bi-modal in clear days and exhibited tri-modal in haze days; Cu, S, Ni showed prominent differences in clear and haze days. For the reason that the enrichment factors of K, Ca, Ti, Mn, Cr were less than 10, they were mainly from natural sources. The enrichment factors of Cl, Pb, As, Ni, Cu, S, Zn were much larger than 10 in clear and haze days, and also the enrichment factors of Ni, Cu, S, Zn were obviously larger in haze days than in clear days.