标签归档:张干

Home party with Professor Zou’s group

Home party with Professor Zou’s group

On September 24, we (Gan Zhang, Xinming Wang and Haoyu Jiang) attended a gathering party of Professor Zou Shichun’s group of Sun-Yat-Sat University. The party took place in an old factory site and presented as a “轰趴“ (home party) style. Three previous students came with their lovely children!

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ICELS in Thailand

Group members attended The 1st ICELS in Bangkok, Thailand

Nov 2-5th,2015
Professor Zhang Gan, Drs Zhong Guangcai & Jabir H. Syed, and Ms Jiang Haoyu attended The first International Conference on Environment, Livelihood and services: Environment for Life(The 1st ICELS) at Bangkok International Convention Center at the Centara Grand Hotel at Central World in Bangkok ,Thailand on November 2-5th,2015.They all gave oral presentations on Environmental Assemblage session. The conference was organized by the Chaipattana Foundation and Kasetsart University.
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Receiving appreciation certificate from Her Royal Highness Princess Maha Chakri Sirindhorn of Thailand.  (诗琳通公主).
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 Professor Zhang Gan was invited to give a Keynote Speech in the closing ceremony titled “Application of radiocarbon analysis and molecular tracers in the source apportionment of carbonaceous aerosols in China”.
t3An attractive girl with her attractive presentation.
t4Jabir talked about e-waste in Pakistan, which attracted many people. Here he is having a dialogue with the session chair.
t6 Two men of narcissism.
t7With the addition of beauty, the photo attraction increased a lot.
t8Handsome boy and beauty.
t9Fancy food in the fancy country for the coffee break.
t10Traditional Thai dance to mimic buddha angel.
t11Elegant Thai girls was dancing northern traditional dance.
t12All the dancers curtsied to the audience.
t14Pizzas upon arrival.
t13Professor Surat (center) is a collaborator of our group on biomass burning in Indo-China peninsula. He is also the dean of Environment Faculty of Kasesart University. This picture was taken in Lam Pak Bia firld station.
t15Gulf Of Siam.
t16Gan Zhang wrote a classic Chinese poem (Ci)on our Thailand (Siam)link. http://blog.sina.com.cn/s/blog_6f655bb70102vq7c.html)

碳十四 (Radiocarbon)

环境14C技术与应用

主要研究人员:张干,朱三元,成志能,钟广财,李军,刘俊文,张向云,姜懿珊,莫扬之,苏涛,孙悦,徐步青

地球上的放射性碳同位素(14C)主要有两个来源,一是宇宙射线下由14N同位素在大气中生成(图1),二是以1960-1970年代为高峰的人类核试验产生的14C在大气中的衰变遗存。二者相互叠加,构成现时大气14C的背景丰度(“现代碳”,Contemporary carbon)。由于核爆高峰期渐行渐远,大气“现代碳”的14C丰度正处于持续衰减中(图2)。

14C具有5730年的半衰期,衰变产物为14N(图1)。因此,源于石油、煤等化石燃料(经上亿年衰变)燃烧的C将不具有放射性(“死碳”);而源于生物质排放及燃烧的碳,将具有与同期大气相近的“现代碳”14C同位素丰度(图2)。故而,利用14C技术,可有效判识“死碳”和“现代碳”对有机质的相对贡献比例,提供其来源信息。

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图1 天然14C的生成和环境命运 (Libby, 1949, Science。Libby因14C工作获Nobel奖)

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图2 不同地表植被(当年生、10年生)、微生物和土壤有机质(SOM)14C丰度的时间变化(Trumbore, 2009, Annu. Rev. Earth Planet. Sci.)

依托有机地球化学国家重点实验室的14C专用加速器质谱(AMS),研究组致力于建立较为完善的AMS-14C分析前处理方法和装置,并将其应用于大气气溶胶、沉积碳埋藏、土壤碳动态等研究领域。目前已建立的技术系统如:

(1)基于热化学原理的两阶段加热气溶胶OC/EC分离-捕集系统(图3,Zhang Yanlin et al., NIMB, 2010; Liu Di et al., 2013, ES&T),经石墨化制靶,以固体源AMS测定14C丰度;

(2)基于OC/EC商用分析仪(Sunrise TOT)的微量样品OC/EC分离制备系统(图4,参考Zhang Yanlin et al., 2012, ACP),用于对气溶胶中的有机质进行分离,并作为CO2收集,以气体源AMS测定14C丰度;

(3)基于催化加氢技术(hydropyrolysis)的有机碳、黑碳(OC-BC)分离方法和装置(图5)。

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图3 基于热化学的两阶段气溶胶OC、EC分离制备系统。Zhang YL, 2010, NIMB; Liu D, 2013, ES&T.

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图4 基于商用OC/EC (TOT)分析仪改装的微量样本OC、EC分离制备与AMS气体源14C测定技术。参考Zhang YL 2012, ACP.

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图5 催化加氢装置。

在此研究方向,我们与瑞士Bern大学Sonka Szidat研究组、瑞典斯德尔摩大学Orjan Gustufsson研究组具合作关系和人员交流。

从2015年开始,受国家基金重点、面上项目和广州市有关项目的支持,相关的方法和技术正/将分别用于以下研究:(1)中南半岛生物质燃烧污染排放;(2)珠江三角洲/广州市灰霾的物质示踪和源解析;(3)河口/海岸带沉积碳埋藏与碳循环过程;(4)森林土壤碳动态。

目前,张向云正完善催化化加氢分离OC/BC的方法;姜懿珊正应用PLFA的单体14C信息,探讨森林土壤碳动态;莫扬之在探索以14C示踪气溶胶中棕碳(BrC)吸光组分的来源;苏涛探讨以14C对气溶胶PMF源解析结果进行制约;徐步青开始研发大气中多元酸(草酸等)的单体化合物分离与14C测定方法;孙悦正建立基于苯多酸(BPCA)的黑炭(BC)和水溶黑炭(DBC)的14C测定技术。