标签归档:成志能

Visiting Henan University

On April 27-28, Yishan, Zhineng, Chunling and Zhang Gan visited professors Wan Shiqiang(万师 强)and Fu Shenglei(傅声雷)of Henan University(河南大学) in Kaifeng (开封), for a discussion about the radiocarbon study on Chinese forest soils. The two top ecologists gave pertinent suggestions and cordial advice. Besides, we occasionally had tea in a tea & flower house beautifully and lovely decorated. It was a  fruitful and memorable trip.

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The gate of Henan University.

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The buddies.

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Yishan explained her results and next-step plan to the professors. Prof Wang Shiqiang (left) is a top scientist in global change ecology (全球变化生态学). Professor Fu Shenglei (right) is a top scientist in soil biogeochemistry (土壤生物地球化学).

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The tea and flower house.

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Relaxed.

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The concert hall of the University.

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School of Environment and Planning.

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School of Life Sciences.

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The Kaifeng Iron Tower(开封铁塔)standing on the University campus was built from 1049 AC in Song dynasty.

viva 2015

Kaijun, Xiaoping and Zhineng did their viva (20150523-24)

On May 23rd, Kaijun did her MSc viva and Xiaoping and Zhineng did their PhD viva. On May 24th, the group was able to gather to celebrate their success. It was a nice evening/night with lots of cheers and singnings.

ga_2015_kai_viva1Released with their gowns. Many congratulations! (20150529)

ga_2015_kai_viva2Xiaoping will continue with her post-doctoral research in the institute. (20150529)

ga_2015_kai_viva3Mengke became of a PDRF. (20150529)

ga_2015_kai_viva4Zheng Qian is going to work in South China Agricultural University (SCAU). (20150529)

ga_2015_kai_viva5Kaijun is always lovely and cute.

ga_2015_kai_viva6I wrote a classic Chinese poem for all beautiful ladies studying in the group, in scientific publication style, with lots of references of cause … 🙂

ga_2015_kai_viva7Brothers and sisters.

ga_2015_kai_viva8With the assessment panel. Shown here are Dr Chen Duohong (陈多宏高级工程师, left 1), Professors Yu Zhiqiang (于志强,left 2),Bi Xinhui (毕新慧, left 3), Wang Xinming(王新明, right 4), Chen Yingjun (陈颖军, 烟台所,right 3), Feng Jialiang (冯家良, 上海大学,right 2), Li Yongtao(李永涛,华南农业大学, right 1).

ga_2015_kai_viva9With the teacher.

ga_2015_kai_viva10Kaijun made great progress in improving her MSc thesis and presentation. Her work and presentation was highly praised by Prof Wang Xinming who was the assessment pannel chair.

ga_2015_kai_viva11Show with more confidence. And know something from the experience?

ga_2015_kai_viva12Xiaoping did impressive work on the PM2.5 source apportionment and air deposition of PAHs in the Bohai Sea.

ga_2015_kai_viva13Zhineng finally escaped from his enduring PhD stage, hopefully knowing what one has devoted in will, out of question, reward in the future.

ga_2015_kai_viva14After dinner.

ga_2015_kai_viva15The second phase of the celebration. The boys were busy drinking.

ga_2015_kai_viva16Two singers.

ga_2015_kai_viva17Girls with happiness.

ga_2015_kai_viva18It was a milky night (1:15am, May 25th).

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。