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Transportation characteristics of δ^(13)C in the plants-soil-bedrock-cave system in Chongqing karst area

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Science China Earth Sciences 2012年第4期55卷 685-694页

作者： li TingYong li HongChun Xiang XiaoJing Kuo Tz-Shing li junyun Zhou Fuli Chen Hongli Peng lingli School of Geographical Sciences Southwest UniversityChongqing 400715China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy SciencesXi'an 710075China Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment Chongqing University and Southwest UniversityMinistry of EducationChongqing 400715China Department of Geosciences Taiwan UniversityTaipei 10617Taiwan Department of Earth Sciences Cheng-Kung UniversityTainan 70101Taiwan

Here we use an analytical method to determine δ^13C in local plants and organic matter in the soils above Furong cave, Chong- qing, China. We also monitored d13C in dissolved inorganic carbon （DIC） of drip water, δ^13C of active deposits under the drip waters, and the concentration of air CO2 （PCO2）. Based on these, we preliminarily studied the transportation characteristics of stable carbon isotope （^13C） in cave system of the subtropical karst area. The average δ^13C value of 27 local plant samples, which belong to 16 families, was -32% and the weighted δ^13C for surface dry biomass was -33%0. We found that for 54 soil samples collected from 5 soil profiles, δ^13C of soil organic matters was -22%o, which could be attributed to the different trans- portation rates of stable carbon isotopes during the decomposition of plants and organic matters in soils. The relatively lighter 12C tended to transfer into gaseous CO2, which made the relatively heavier ^13C concentrated in the soils. On the basis of moni- toring of DIC- δ^13C in drip waters from July 2009 to June 2010, we found that values in winter months were heavier and values in summer months were lighter in general, the reason of which was that in summer months, both the temperature and the hu- midity were comparatively higher, resulted in more CO2 with lighter δ^13C generated from organic matters decomposition and plants respiration. The average DIC- δ^13C value was -11%o, about 11%o heavier than the δ^13C of organic matters in soils, which proved that part of DIC in cave drip water was sourced from dissolution of inorganic carbonate （host rock, with heavier δ^13C. As for the δ^13C of active deposits at five drip water sites in Furong cave, they had almost the same variation with relatively light values. In other words, these active speleothems were deposited at equilibrium conditions for isotopic fractionation. These results suggest that the carbon isotopic information of speleothems could be used to track

关键词： karst area δ^13 plant soil organic matter DIC-δ^13 in drip water active speleothems

Human activity and climate change triggered the expansion of rocky desertification in the karst areas of Southwestern China

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Science China Earth Sciences 2021年第10期64卷 1761-1773页

作者： Chaojun CHEN Daoxian YUAN Hai CHENG Tsailuen YU Chuanchou SHEN RLawrence EDWARDS Yao WU Siya XIAO Jian ZHANG Tao WANG Ran HUANG Ziqi liU Tingyong li junyun li Chongqing Key Laboratory of Karst Environment School of Geographical SciencesSouthwest UniversityChongqing 400715China Key Laboratory of Karst Dynamics MNRGuangxiInstitute of Karst GeologyChinese Academy of Geological SciencesGuilin 541004China Yunnan Key Laboratory of Plateau Geographical Processes&Environmental Changes Faculty of GeographyYunnan Normal UniversityKunming 650500China Institute of Global Environmental Change Xi’an Jiaotong UniversityXi’an 710049China High-precision Mass Spectrometry and Environment Change Laboratory(HISPEC) Department of GeosciencesTaiwan UniversityTaipei 10617China Research Center for Future Earth Taiwan UniversityTaipei 10617China Global Change Research Center Taiwan UniversityTaipei 10617China Department of Earth Sciences University of MinnesotaMinneapolisMN 55455USA Environnements et Paléoenvironnements Océaniques et Continentaux(EPOC) UMR CNRS 5805Universitéde BordeauxPessac 33600France School of Karst Science Guizhou Normal UniversityGuiyang 550001China

It is conducive to the sustainable development of human beings in karst regions to research the mechanism of karst rocky desertification(KRD)*** the large-scale KRD in southwestern China is caused by climate change or human activities is still *** this study,the evolution of the KRD in southwestern China over the past 2000 years was reconstructed through the high-precisionδ^(13)C record of stalagmites from Shijiangjun(SJJ)Cave,Guizhou Province,***δ^(13)C of the stalagmites from SJJ Cave exhibited heavy values from the Medieval Warm Period(MWP)to the little Ice Age(liA).Furthermore,theδ^(13)C records of other stalagmites and tufa from southwestern China also showed the same significant heavy *** the stalagmiteδ^(13)C could record the change of ecological environment,it indicated that the consistent change of the stalagmitesδ^(13)C may record the process of KRD expansion in the karst regions of southwestern *** the MWP,the stronger Asian summer monsoon and the northward movement of the rain belt led to a dry period in southwestern China and a wet period in northern *** contrast,it was wet in southwestern China and dry in northern China during the *** addition,after the Jing-Kang event(JK event,AD1127)occurred at the end of the Northern Song dynasty,the political and economic center of China migrated to southern China for the first time,which changed the population distribution pattern of larger population in the north and smaller population in the ***,the expansion of KRD in southwestern China was exacerbated in the MWP due to the change of climate in southwestern China,the migration of a large number of people,wars,the large-scale reclamation of arable land,and the cultivation of large areas of crops.

关键词： Karst rocky desertification Jing-Kang event Stalagmiteδ13C record Medieval Warm Period little Ice Age

宫颈癌腔内联合组织间插植近距离放疗施源器模板的应用

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中华放射肿瘤学杂志 2024年第2期33卷 137-144页

作者：欧阳翼黄晓丹陈佛平伍海莹叶伟军陈锴李珺芸刘红英麦苗青顾慧宽林焕新曹新平中山大学肿瘤防治中心放疗科、华南肿瘤学国家重点实验室、广东省恶性肿瘤临床医学研究中心广州510060

目的设计适用于局部晚期宫颈癌的腔内联合组织间插植近距离放疗(IC-ISBT)施源器模板,并评估其应用价值。方法收集2019年3月至2020年9月中山大学肿瘤防治中心收治的100例ⅡB-ⅣA期(国际妇产科协会2018分期)宫颈癌患者的外照射前后磁共振... 详细信息

目的设计适用于局部晚期宫颈癌的腔内联合组织间插植近距离放疗(IC-ISBT)施源器模板,并评估其应用价值。方法收集2019年3月至2020年9月中山大学肿瘤防治中心收治的100例ⅡB-ⅣA期(国际妇产科协会2018分期)宫颈癌患者的外照射前后磁共振影像资料,对宫颈原发病灶范围进行回顾性阅片分析对比。基于外照射后肿物残留情况,勾画近距离放疗高危临床靶区(HR-CTV),设计腔内联合组织间插植近距离放疗(IC-ISBT)的施源器模板,并进一步评估施源器模板插植组(37例)与徒手插植组(63例)治疗宫颈癌的剂量和疗效差异。分类变量采用卡方检验或Fisher精确检验,连续变量采用t检验或U检验。结果100例宫颈癌患者外照射后残留肿物边缘按顺时针3、6、9、12点方向与宫颈管中心的距离中位数为16.5、14.0、17.0、13.0 mm。将对应的HR-CTV叠加重建三维图,设计制作蘑菇头圆柱体式IC-ISBT施源器模板:头部长径为35 mm,短径为20 mm,中心适配宫腔管,内圈C1-C12为表盘式排列,两侧拓展B1-B5及A1-A4针道。在剂量方面,模板插植组与徒手插植组的HR-CTV D90%[(635.12±22.65)∶(635.80±25.84)cGy]、膀胱D_(2cm^(3))[(473.79±44.78)∶(463.55±66.43)cGy],直肠D_(2cm^(3))[(396.99±73.54)∶(408.00±73.94)cGy]及乙状结肠D_(2cm^(3))[(293.07±152.72)∶(311.31±135.77)cGy]无明显差异(P>0.05),但前者的HR-CTV D98%较高[(544.78±32.07)∶(536.78±32.04)cGy,P=0.007],直肠D1 cm3及D0.1 cm3较低[(438.62±69.65)∶(453.97±67.89)cGy,P=0.016;(519.46±70.67)∶(543.82±81.24)cGy,P=0.001]。两组的宫颈原发灶完全缓解率(86%∶83%,P>0.05)无差异。结论该IC-ISBT施源器模板设计合理,与徒手插植疗效相当,靶区剂量覆盖符合临床需求,可更好地保护危及器官。其使用操作简便,可重复性强,有望作为常规模板推广应用。

关键词：宫颈肿瘤,局部晚期近距离放射疗法腔内联合组织间插植施源器模板徒手插植剂量分析

ATM 网中固定速率业务的信元时延偏差研究

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清华大学学报（自然科学版） 1998年第3期38卷 41-44页

作者：李俊蕴曾烈光清华大学电子工程系

信元时延偏差（ＣＤＶ）是ＡＴＭ网内引起信元丢失的主要原因之一。文中系统地分析了固定速率业务（ＣＢＲ）的ＣＤＶ的相关特性，包括信元时延特性、复用后信元流的分布特性及ＣＤＶ的影响与监控。采用固定速率业务与独立同分布的背景... 详细信息

信元时延偏差（ＣＤＶ）是ＡＴＭ网内引起信元丢失的主要原因之一。文中系统地分析了固定速率业务（ＣＢＲ）的ＣＤＶ的相关特性，包括信元时延特性、复用后信元流的分布特性及ＣＤＶ的影响与监控。采用固定速率业务与独立同分布的背景业务相叠加的ＦＩＦＯ离散排队系统，求出了稳态时ＣＢＲ信元时延、复用后信元流分布的母函数和信元流分布的极限情况，然后以求得的信元流分布为输入，求出了有ＣＤＶ的ＣＢＲ信元流通过漏桶监控机制时的违例信元概率，并以随机业务的泊松分布为例给出了数值计算结果。

关键词：异步转移模式固定速率业务信元时延偏差 ATM网

利用石笋δ^(13)C重建岩溶石漠化研究进展

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中国岩溶 2022年第4期41卷 660-674页

作者：徐玉珍李廷勇李俊云杨琰岩溶环境重庆市重点实验室西南大学地理科学学院重庆400715 云南省高原地理过程与环境变化重点实验室云南师范大学地理学部云南昆明650500

岩溶石漠化的形成演化机制是被关注的科学问题,对脆弱的岩溶区生态环境恢复具有重要的现实意义。洞穴石笋δ^(13)C受到多种因素影响,能敏感响应地表生态环境以及岩溶水文条件的变化。因此,利用石笋δ^(13)C研究岩溶地区生态环境演变历... 详细信息

岩溶石漠化的形成演化机制是被关注的科学问题,对脆弱的岩溶区生态环境恢复具有重要的现实意义。洞穴石笋δ^(13)C受到多种因素影响,能敏感响应地表生态环境以及岩溶水文条件的变化。因此,利用石笋δ^(13)C研究岩溶地区生态环境演变历史成为一个重要方向。本文从地表环境和洞穴沉积两个方面梳理了影响石笋δ^(13)C的主要因素。结合现代洞穴监测及模型模拟研究,分析整理了影响洞穴滴水和沉积物中δ^(13)C的主要因素和机理。在多重因素的影响下,石笋δ^(13)C的环境意义具有多解性,文章从时间尺度、空间分布、沉积环境三方面归纳了石笋δ^(13)C的指示意义。为了准确解释石笋δ^(13)C环境意义,提出了综合分析、现代监测以及模型模拟的解决方案。通过对岩溶石漠化概念、成因、发展过程、以及环境效应的讨论,分析了地表石漠化与石笋δ^(13)C记录的密切联系。总结了已经发表的利用石笋δ^(13)C重建区域石漠化的研究成果,讨论了目前研究中面临的主要问题:(1)如何正确解译石笋δ^(13)C的指示意义?这是石笋δ^(13)C能够用于重建区域石漠化历史的前提;(2)在空间上,石笋δ^(13)C记录反映上覆地表的面积是有限的,需考虑石笋能否代表目标研究区域的环境变迁;(3)石漠化可在年—十年际时间尺度上快速发展,而石笋测年存在一定的年龄误差,石笋δ^(13)C是否能够敏感记录地表的石漠化过程?为了准确重建区域岩溶环境以及石漠化演变历史,提出以下主要建议:(1)为了避免石笋δ^(13)C重建古环境的不确定性,可加强石笋δ^(13)C与δ^(18)O、微量元素、矿物结构等指标的综合对比分析,与现代监测以及模型模拟的解决方案综合集成,能更加准确重建研究区岩溶水文变化过程,判定石漠化的演化历史;(2)通过区域和同一洞穴的多根石笋记录对比,减少单一石笋记录的区域代表性问题;(3)高精度年代控制的高分辨率多指标石笋记录,有助于捕捉快速发生的石漠化过程。

关键词：岩溶石漠化洞穴石笋石笋δ^(13)C 古环境重建

Copper iodine cluster nanoparticles for tumor-targeted X-ray-induced photodynamic therapy

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Science China Materials 2024年第10期67卷 3358-3367页

作者： Wei Xie junyun Chen Yuxin Zhang Biyuan Zheng Xingshu li Jian-Dong Huang Fujian Provincial Key Laboratory of Cancer Metastasis Chemoprevention and Chemotherapy College of ChemistryFuzhou UniversityFuzhou 350108China

The weakness of visible and near-infrared light penetration depth limits the application of photodynamic therapy(PDT)in deep-seated *** on the high penetrability of X-rays,X-ray-induced PDT(X-PDT)is a promising new method for treating deep-seated ***,it requires the development of suitable X-ray-induced sensitizers that could employ X-ray energy to produce reactive oxygen species(ROS)*** this study,a novel X-rayinduced sensitizer(NanoSRF)was developed through a microemulsion method,in which copper iodine cluster compound Cu_(2)I_(2)(tpp)2(2,5-dm-pz)(CIP)and rose bengal(RB)worked as scintillator and photosensitizer,*** was synthesized by a simple mechanical grinding method,and subsequently folic acid(FA)-modified albumin was introduced to enable its alliance with *** exhibited excellent dispersion stability and generated a large amount of ROS under X-ray *** results of in vitro studies demonstrated its high selectivity for FA receptor-positive cancer *** systemic administration,NanoSRF accumulated in H22 tumors of xenograft-bearing mice,and Xray irradiation(5.46 Gy)induced a significant inhibition rate of 96.7%in tumor *** study pioneers the use of copper iodide cluster as a scintillator in X-PDT,presenting new possibilities for designing scintillators with exceptional X-ray absorption and efficient X-PDT capabilities.

关键词： X-ray-induced photodynamic therapy copper iodine cluster nanoparticle tumor target

High-resolution climate variability of southwest China during 57―70 ka reflected in a stalagmite δ^(18)O record from Xinya Cave

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Science China Earth Sciences 2007年第8期50卷 1202-1208页

作者： li TingYong1, YUAN DaoXian1,2, li HongChun1,3 ,YANG Yan2, WANG Jianli1, WANG XinYa1, li junyun1, QIN JiaMing2, ZHANG Meiliang2 & liN YuShi2 1 College of Geographical Science, Southwest University, Chongqing 400715, China 2 Karst Dynamics Laboratory, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, China 3 Department of Earth Sciences, Cheng-Kung University, Tainan 70101, Taiwan, China College of Geographical Science Southwest University Chongqing China Karst Dynamics Laboratory Institute of Karst Geology Chinese Academy of Geological Sciences Guilin China Department of Earth Sciences Cheng-Kung University Tainan Taiwan China

A 26-cm-long stalagmite (XY2) from Xinya Cave in northeastern Chongqing of China has been ICP-MS 230Th/U dated, showing a depositional hiatus at 2.3 cm depth from the top. The growth of the 2.3―26 cm interval determined by four dates was between 57 ka and 70 ka, with a linear growth rate of 0.023 mm/a. We have analyzed 190 samples for δ 18O and δ 13C, mostly in the 2.3―26 cm part. The δ 18O and δ 13C values between 57 ka and 70 ka reveal decadal-to-centennial climatic variability during the glacial in-terval of Marine Isotope Stage 4 (MIS4), exhibiting much higher resolution than that of the published Hulu and Dongge records during this interval. Speleothem δ 18O in eastern China, including our study area can be used as a proxy of summer monsoon strength, with lighter values pointing to stronger summer monsoon and higher precipitation, and vice versa. Two decreases in the δ 18O signature of XY2 record around 59.5 and 64.5 Ka are argued to correspond to the Dansgaard-Oeschger (D-O) events 17 and 18 respectively. The Heinrich event 6 (H6) can be identified in the record as a heavy δ 18O peak around 60 ka, indicating significant weakening of the monsoon in Chongqing during the cold period. The XY2 δ 18O record shows very rapid change toward to the interstadial condition of the D-O event, but more gradual change toward to the cold stadial condition. This phenomenon found in the Greenland ice core records is rarely observed so clearly in previously published speleothem records. According to SPECMAP δ 18O record, the glacial maximum of MIS 4 was around 64.5 ka with the boundary of MIS 3/4 around 60 ka. Unlike the marine record, the speleothem record of XY2, China, exhibits much high fre-quency variations without an apparent glacial maximum during MIS 4. However, the timing of MIS 3/4 boundary seems to be around 60 ka when the H6 terminated, in agreement with the marine chronology. The growth period of sample XY2 during glacial times probably reflects a local karstic routi

关键词： stalagmite U-series dating oxygen isotope records MIS4 D-O cycles H6 event Chongqing China

基于物联网技术的城市景观照明智能控制系统及其应用——以上海虹口北外滩景观照明提升项目为例

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照明工程学报 2020年第5期31卷 131-136页

作者：周娜李军云杨贇上海现代建筑装饰环境设计研究院有限公司上海200041 众盒智能科技(上海)有限公司上海201800

随着城市夜景照明规模的扩大,效果呈现的多样化,传统的照明控制方式已不再适用。物联网技术为城市景观照明智能控制系统的搭建提供了强大的技术支撑。本文以上海虹口区北外滩景观照明提升项目为例,从物联网架构的“云、管、边、端”等... 详细信息

随着城市夜景照明规模的扩大,效果呈现的多样化,传统的照明控制方式已不再适用。物联网技术为城市景观照明智能控制系统的搭建提供了强大的技术支撑。本文以上海虹口区北外滩景观照明提升项目为例,从物联网架构的“云、管、边、端”等方面探讨了如何利用大量存量灯光进行控制系统的整合优化,实现既有灯光项目的联动效果,又满足智能化控制和精细化管理的要求。这将对城市景观照明建设和高效管控起到一定的借鉴作用。

关键词：物联网城市景观照明智能照明控制系统北外滩景观照明提升

基于石笋记录的晚全新世太平洋东西两岸季风区气候事件对比研究

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第四纪研究 2019年第3期39卷 742-754页

作者：黄冉陈朝军李廷勇吴尧肖思雅张键王涛李俊云西南大学地理科学学院岩溶环境重庆市重点实验室重庆400715 自然资源部岩溶生态环境-重庆南川野外研究基地重庆408435

研究晚全新世季风气候演变有助于进一步认识与预测未来季风区气候变化。太平洋东西两岸是全球季风集中分布的地区,已经有大量的古气候记录发表,但是缺乏对各个季风区气候突变事件以及整体变化趋势的对比研究。针对这一问题,选取亚洲季... 详细信息

研究晚全新世季风气候演变有助于进一步认识与预测未来季风区气候变化。太平洋东西两岸是全球季风集中分布的地区,已经有大量的古气候记录发表,但是缺乏对各个季风区气候突变事件以及整体变化趋势的对比研究。针对这一问题,选取亚洲季风区、印澳季风区、北美季风区、南美季风区11个洞穴石笋δ18O和1个湖泊Ti含量,对比研究各个记录在3.5~0.5 ka B.P.期间指示的夏季风变化特征。通过对比发现四大季风区的石笋δ18O在晚全新世整体上呈现偏正趋势,指示夏季风减弱;2次重要的气候突变事件1.5 ka B.P.和2.7 ka B.P.弱夏季风事件在各个季风区内均有表现;同时也记录了一系列十年际-百年际尺度的弱夏季风事件,表明太平洋东西两岸和南北半球的夏季风都有减弱的趋势,这与先前研究认为的南北半球呈现"see-saw"模式表现出不一样的特征。晚全新世以来ENSO(El Nino-Southern Oscillation)活动的增强对太平洋东西两岸南北半球夏季风减弱具有重要影响。在El Nino事件发生时,Walker环流减弱,而且它的上升支向东移动远离西太平洋暖池,西太平洋副热带高压增强并向西移动,导致亚洲夏季风减弱。Walker环流的东移也会使得印度尼西亚-太平洋暖池(Indo-Pacific Warm Pool,简称IPWP)海温下降,热带季节内震荡减弱致使印澳夏季风减弱;此外,El Nino事件发生时,赤道东太平洋海水温度上升导致东西太平洋海水温度梯度减弱,在此状态下南美季风区低空急流(Low Level Jet,简称LLJ)减弱,导致南美夏季风减弱;同时,北美洲加勒比海低空急流增强,使得该季风区下沉气流增强,导致北美夏季风减弱。我们的研究表明,在晚全新世ENSO活动增强的状态下,太平洋东西两岸南北半球夏季风变化可能都呈现减弱趋势。

关键词：石笋δ^18O 太平洋东西两岸季风区晚全新世 ENSO