Spatial pattern of Abies and Picea surface pollen distribution along the elevation gradient in the Qinghai–Tibetan Plateau and Xinjiang, China     

HOUYUAN LU  NAIQIN WU  XIANGDONG YANG  CAIMING SHEN  LIPING ZHU  LUO WANG  QUAN LI  DEKE XU  GUOBANG TONG  XIANGJUN SUN 《Boreas: An International Journal of Quaternary Research》2008,37(2):254-262

In this study we examine the relationships between Abies and Picea abundance in surface pollen and sub-alpine coniferous forest (SCF) distribution, elevation and climate in the Qinghai–Tibetan Plateau using a large modern pollen data set consisting of 857 samples. Results indicate that Abies and Picea pollen are abundant in the southern and eastern Qinghai–Tibetan Plateau, where SCF dominates the landscape. Pollen percentages of both Abies and Picea show a unimodal pattern with changes in elevation and climate, and their optima occur at elevations from 2500 to 4000 m a.s.l., mean annual temperature from −1 to 10 °C and mean annual precipitation from 450 to 850 mm. The optimal elevation of Abies and Picea pollen distribution decreases with latitude from c . 4000 m in the south (21–32°N) to c . 2500 m in the north (43–49°N). The spatial pattern of Abies and Picea pollen abundance is highly correlated with the modern distribution of these taxa, which is largely controlled by elevation and climate. These relationships could provide a practical reference for interpretation of fossil pollen data in terms of climate and elevation in the Qinghai–Tibetan Plateau.  相似文献   

基于Atmega16的多点温湿度测控系统设计     

权伟  蔡淮  于小娟 《成都信息工程学院学报》2007,22(4):503-508

介绍了基于Atmega16单片机为检测和控制核心,并同多个数字温度传感器DS18B20及模拟湿度传感器HS1101构成温度与湿度的测控系统.给出了系统的总体设计方案、硬件设计及软件框图.所设计的粮情测控系统具有优良的性价比,通过系统软硬件的联合调试说明,该系统可以满足对温湿度及烟雾进行实时监控的需要,具有稳定性好、精度高等特点,有一定的应用价值.  相似文献   

Geochronology and Geochemistry of Ore-related Granitoids in the Giant Gariatong Rb Deposit, Tibet and Implications for Rb Metallogeny in China     

LIN Bin  TANG Juxing  TANG Pan  SUN Yan  QI Jing  M. SANTOSH  XIE Jinling  DENG Shilin  LI Faqiao  XIE Fuwei  ZHOU Aorigele 《《地质学报》英文版》2024,98(1):83-103

Rubidium (Rb) deposits mostly occur in the South China and Central Asia orogenic belts and are often closely associated with highly differentiated granites. This study investigates a newly-discovered giant Rb deposit at Gariatong in the Central Lhasa terrane in Tibet. Detailed field studies and logging data revealed that the Rb mineralization mainly occurs in monzogranite and is related to greisenization. LA-ICP-MS U-Pb dating of zircon yielded ages of 19.1 ± 0.2 Ma and 19.0 ± 0.2 Ma for greisenized monzogranite and fresh monzogranite, respectively. The monzogranites are characterized as strongly peraluminous, with high contents of SiO2, Al2O3, K2O and Na2O as well as a high differentiation index. They are enriched in light rare earth and large ion lithophile elements with signi?cant negative Eu anomalies and depleted high field-strength elements. Petrological and geochemical features of these ore-related monzogranites suggest that they are highly fractionated S-type granites, derived from remelting of crustal materials in a post-collisional setting. The geochemistry of zircon and apatite points to a low oxygen fugacity of the ore-related monzogranite during the magma’s evolution. The discovery of the Gariatong Rb deposit suggests that the Central Lhasa terrane may be an important region for rare metal mineralization.  相似文献   

疫情防控期“数字地形测量学”线上教学实践     

曹先革  杨金玲  王霞迎 《测绘工程》2021,30(3):72-76

疫情之下,在线教学为“停课不停教、停课不停学”提供了理想的教学方案。基于超星泛雅网络教学平台,以“数字地形测量学”在线课程建设为例,探索在线课程的建设方法与途径,构建“能学、辅教”的立体化教学资源,进行“超星泛雅+学习通+腾讯课堂+课程QQ群”混合教学模式的探索和实践,为在线课程建设与应用提供借鉴。  相似文献   

甘肃东部一次暴雪过程的诊断分析和数值模拟   总被引：3，自引：0，他引：3  

冀兰芝  全志伟  宋琳琳  孔祥伟  张静 《干旱气象》2014,(5):845-850

应用NCEP1°×1°的6 h再分析资料和常规气象观测资料以及RUC模式高分辨资料,对2013年2月17日甘肃河东暴雪天气从天气实况、环流特征、水汽条件、动力条件及西北区域RUC模式输出的模拟结论进行了诊断分析。结果表明：高空冷槽、700 hPa低涡、地面冷锋是这次暴雪的主要影响系统;降雪前期,低层正涡度增强,低层辐合、高层辐散是暴雪发生的动力机制;降雪前期,由于低涡辐合作用,700 hPa高度以下,湿度猛增,为降雪提供了充沛的水汽条件;降雪中心和政上空有θse密集强能量锋区;西北区域RUC模式模拟的24 h内降水量范围、落区、量级与实况一致,模拟的地面风速偏大。  相似文献   

����GPS�����۲�̨������������������     

陈超贤  陈光  王青平  王紫燕  杨锦玲  许振栋 《大地测量与地球动力学》2014,34(4):17-20

????TEQC????????GPS????????????????????????????????????м????????????????M_P1??M_P2??CSR?????????????????IGS??????????????????飬?ó???1????????????????????????з??????仯,???????????仯?????,??????????????????????????????????????Χ?????????????Χ?????????￡?2?????????????????????????????????????????????????????????????и???????????????3??“????”?????30????????90%????IGS????????????????????????????Χ??????????????  相似文献   

利用时空信息的单波段地表温度遥感反演     

陈峰  赵小锋  全元  柳林 《遥感学报》2014,18(3):657-672

地表温度被认为是影响生态系统的关键因子之一,它与许多地表过程有关。目前,热红外卫星遥感技术是获取有关区域和全球尺度地表温度信息的一个有效、可行的手段。针对不同卫星上搭载的热红外传感器,许多学者开展了大量的研究,其中针对单波段热红外的特点(如Landsat TM/ETM+,CBERS和HJ-1B)提出了单通道(或单窗)算法。该类算法需要准确的地表比辐射率和大气参数(如大气水分含量)。这些参数在现实中又很难轻易获得,从而在一定程度上限制了现有算法的应用。针对HJ-1B高回访频率的特点,本文提出了利用多时相影像的时空信息来直接反演地表温度的Multi-Temporal and Spatial Information-Based Single Channel(MTSC),以解决现有算法对地表比辐射率和大气参数的过度依赖性。实例分析结果显示,基于MTSC法由HJ-1B反演得到的地表温度结果与MODIS地表(陆表和海表)温度产品具有很好的空间一致性;HJ-1B的陆表温度结果总体上被高估了约1 K,而海表温度结果总体上被高估了0.5 K;同时,MTSC法得到的HJ-1B地表温度结果具有更好的细节和空间完整性。最后,通过分析和讨论指出了一些可能的完善途径,如相似像元的确定、修改优化求解中的目标函数、参数的自适应初始化等,以便提高MTSC法的反演精度和实用性。  相似文献   

矿井断层构造复杂程度的GIS与熵值耦合评价研究     

李飞  杨滨滨  张金陵  段李宏 《中国煤炭地质》2014,(8):60-63

基于GIS与熵值耦合理论的矿井断层构造复杂程度的综合评价方法,建立了断层构造的非线性特征值、断层规模指数、煤层底板倾角指数、断层断距指数等与矿井构造复杂程度相关的评价指标体系。并以河南某矿为例,对矿井断层构造复杂程度进行多因素评价综合分区。结果显示:该矿井构造以中等和简单为主;在构造简单-中等区,构造对煤层开采基本无影响,而在构造复杂区,断层可导致水文地质条件变得较为复杂,影响煤层安全开采。  相似文献   

Pretreatment Techniques for Arsenic Speciation Analysis in Biosamples     

GUO Jinling  YU Xiaoping  GUO Yafei  DENG Tianlong 《《地质学报》英文版》2014,88(Z1):323-325

正Introduction Coupled techniques such as HPLC–HG–AAS,HPLC–ICP–MS,HPLC–HG–AFS are widely used for arsenic speciation analysis in biosamples,during which pretreatment method usually plays a significant role.This  相似文献   

天津市残疾人社会空间分异     

邱宁  韩欣宇  周卫  权海源 《地域研究与开发》2022,41(2):174-180

  相似文献