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The surface pollen and relative pollen production of the desert vegetation of the Alashan Plateau, western Inner Mongolia

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Chinese Science Bulletin 2003年第14期48卷 1488-1493页

作者： U.Herzschuh H.Kuerschner mayuzhen InstituteofPlantSystematicsandGeobotany FreeUniversityofBer-lin.Germanw DepartmentofGeography LanzhouUniversityLanzhou730000China

This preliminary investigation focuses on the comparison of the recent pollen precipitation and its related vegetation of eight different plant communities in the Alashan Region, the most western part of the Inner Mongolia Autonomous Region. Most zonal and azonal communities can be well identified by their pollen spectra. Relative pollen production factors of various plant taxa have been calculated and the following sequences from over- to under represented taxa have been found for zonal vegetation: Chenopodiaceae, Artemisia, Ephedra, Nitraria, Reaumuria, Calligonum, Zygophyllum; and for azonal vegetation: Peganum, Populus, Tamarix, Lycium.

关键词：内蒙古西部沙漠植被花粉植物分布植物群落地带性植被

Holocene abrupt climate shifts recorded in Gun Nuur lake core,northern Mongolia

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Chinese Science Bulletin 2004年第5期49卷 520-526页

作者： WANGWeiguo FENGZhaodong LEEXinqing ZHANGHucai mayuzhen ANChenbang GUOLanlan NationalLaboratoryofWesternEnvironmentSystems MOELanzhouUniversityLanzhou730000China

A continuous 7.44 m lake core was successfully drilled at Gun Nuur Lake, northern Mongolia, and analyses on environment magnetic parameters, organic matter content and organic δ^13C were conducted in an attempt to retrieve the Holocene chronosequence of climatic changes based on 6 AMS ^14C dates. We found that the Holocene climate in northern Mongolia has been alternating between cold (or cool)/wet conditions and warm/arid conditions, and also punctuated with a series of abrupt climate shifts. The abrupt climate shifts occurred around 1750, 2800, 4000, 5200, 7200, and 9200 aBP (^14C age), being chronologically correlative to those abrupt climatic events recorded in the high-latitude North Atlantic Ocean. The correlation indicates that the climatic changes in northern Mongolia were linked with those in the North Atlantic Ocean probably via the North Atlantic Oscillation-affected westerly winds. The strength and position of westerly winds might have modulated the Siberian-Mongolian high pressure system (winter monsoon), directly influencing the climate in China.

关键词：全新世气候变化蒙古北部地区 GunNuur湖磁性参数

Pollen-recorded climate changes between 13.0 and 7.0 ^(14)C ka BP in southern Ningxia,China

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Chinese Science Bulletin 2007年第8期52卷 1080-1088页

作者： SUN AiZhi mayuzhen FENG ZhaoDong LI Fei WU HuiNing MOE Key Laboratory of Western China's Environmental Systems & College of Earth & Environment Sciences Lanzhou University Lanzhou 73000 China College of Resources and Technology Beijing Normal University Beijing 100875 China Department of Geology Baylor University Waco TX 76798 USA

A pollen record from Haiyuan section in the southern part of Ningxia revealed a detailed history of vegetation variation and associated climate changes during the period from^13.0 to^7.0 14 C ka BP.A steppe landscape under a moderately dry(and probably cool)condition(~12.7-~12.1 14 C ka BP)was replaced by a coniferous forest dominating the landscape under a generally wet climate from^12.1 to ~11.01 4C ka *** generally wet period,corresponding to the European B?lling/All?rod period,can be divided into three stages:a cool and wet stage between^12.1 and^11.4 14 C ka BP,a mild and rela- tively dry stage between^11.4 and^11.2 14 C ka BP,and a mild and wet stage between^11.2 and^11.0 14 C ka *** coniferous forest-dominated landscape was then deteriorated into steppe landscape (~11.0-~10.6 14 C ka BP)and further into a desert steppe landscape from^10.6 to^9.8 14 C ka BP,being correspondent to the European Younger Dryas *** a brief episode of a cool and wet climate (~9.8-~9.6 14 C ka BP),a relatively mild and dry condition prevailed during the early Holocene(~9.6- ~7.6 14 C ka BP)and then a warm and humid climate started the mid-Holocene(~7.6-~7.2 14 C ka BP).

关键词：中国宁夏南部花粉记录气候变化植被历史

Late Glacial and Holocene vegetation history and paleoclimate of the Tengger Desert,northwestern China

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Chinese Science Bulletin 2003年第14期48卷 1457-1463页

作者： mayuzhen ZHANGHucai H.-J.Pachui B.Wtinnemann LIJijun FENGZhaodong NationalLaboratoryofWesternChina'sEnvironmentalSystems CollegeofEarth&EnvironmentSciencesLanzhouUniversityLan-zhou730000China Geolab. InstituteofGeographicalSciencesFreeUniversityofBerlinMalteserStr.74-10012249Berlin.Germany DepartmentofEarthandEnvironmentalStudies MontclairstateUni-versityNJ07043USA

Sediments spanning the last 30000 yr BP wereobtained from two sections in the southern part of the Teng-ger Desert, northwestern China (3810′46″N, 10245′53″E). The pollen assemblage suggested a Picea forest domination under a wetter and cooler environment from 27580 to 23510 yr BP. During the following period from 23510 to 21880 yr BP a Cyperaceae meadow occurred under a wet and coldclimate. Wetter and cooler conditions returned and a Piceaforest re-occupied this region between 21880 and 20910 yrBP. From 20910 to 15590 yr BP a steppe under a dryenvironment dominated the region. The first temperatureincrease started at ca.15590 yr BP. The pollen assemblagecovering the period between 15590 and 10890 yr BP can be divided into six minor zones, suggesting that the vegetation compositions changed rapidly under unstable *** 10710 and 10370 yr BP the climate became cold and dry again. The climatic conditions became warmer and more humid between 10260 and 9140 yr BP. From 8450 to 7950 yr BP a steppe landscape under a dry climate occupied this region. Between 7950 and 7290 yr BP climate seemed more humid. The following period from 7290 to 5670 yr BP wasgenerally warm. The period between 5670 and 3510 yr BPwas characterized by dramatic climatic *** cold intervals appeared around 7760 and 7380,6490—6290, 5670—5010, 4470—3510 yr BP. Twopronounced dry events occurred in 6290—5670 and 5010—4470 yr BP with a marked wet spell from 3510 to 3000 yr BP.

关键词：中国西北地区腾葛尔沙漠古气候全新世晚冰期古植被孢粉学

超声多普勒对藏族孕晚期胎儿脐带血流动力学的影响

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西藏医药 2024年第2期45卷 24-25页

作者：李丹尼玛玉珍西藏自治区人民医院超声科西藏拉萨850000

目的探讨超声多普勒对藏族孕晚期胎儿脐带血流动力学的影响。方法选取2022年1月~2023年12月在我院行产前检查及生产的孕产妇69例。以孕周将28~31+6周设为A组、32~35+6周设为B组、36~40周设为C组,用彩色多普勒超声系统自动测量功能,采集... 详细信息

目的探讨超声多普勒对藏族孕晚期胎儿脐带血流动力学的影响。方法选取2022年1月~2023年12月在我院行产前检查及生产的孕产妇69例。以孕周将28~31+6周设为A组、32~35+6周设为B组、36~40周设为C组,用彩色多普勒超声系统自动测量功能,采集胎儿脐动脉的搏动指数(PI)、阻力指数(RI)、脐动脉收缩期/舒张期流速比值(S/D)参数,记录并进行统计学处理。结果PI:A组1.17±0.13、B组1.04±0.14、C组0.96±0.15;RI:0.67±0.06、0.63±0.05和0.60±0.06;RI:3.10±0.52、2.87±0.51和2.53±0.40;PI、RI及S/D在不同孕周之间均有统计学差异,随着孕周增长呈下降趋势。结论高原地区(>3000米)正常妊娠胎儿脐带胎盘循环阻力随着孕周增加逐渐减低,孕晚期胎儿脐动脉PI、RI及S/D平均值较平原地区高。

关键词：超声多普勒胎儿脐动脉高原地区孕晚期

藏南羊卓雍错沉积物元素地球化学记录的过去2000年环境变化

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地理学报 2019年第7期74卷 1345-1362页

作者：郭超蒙红卫马玉贞李丹丹胡彩莉刘杰瑞雒聪文王凯北京师范大学地理科学学部地表过程与资源生态国家重点实验室北京100875 湖北文理学院资源环境与旅游学院襄阳441053 云南师范大学旅游与地理科学学院昆明650500

以青藏高原南部的羊卓雍错(简称羊湖)沉积岩芯为研究对象,以较可靠的年代数据(210Pb和AMS14C交叉定年)为框架,基于高分辨率的元素地球化学记录,通过数理统计分析方法提取环境信息,结合粒度和磁化率,重建该地区过去2000年来的环境变化。... 详细信息

以青藏高原南部的羊卓雍错(简称羊湖)沉积岩芯为研究对象,以较可靠的年代数据(210Pb和AMS14C交叉定年)为框架,基于高分辨率的元素地球化学记录,通过数理统计分析方法提取环境信息,结合粒度和磁化率,重建该地区过去2000年来的环境变化。结果显示,该区黑暗时代冷期(DCAP)和小冰期(LIA)气候较为寒冷,降水量较高;而中世纪暖期(MWP)和现代暖期(CWP)气候较为温暖,降水量较低,气候具有冷湿—暖干的特征。其中,重建的温度显示,中世纪暖期的温暖程度似乎持平甚至超过20世纪暖期;小冰期期间可能存在一次百年尺度的温暖事件,而17世纪和18世纪可能是过去2000中最寒冷的一段时期。分析发现,过去2000年以来青藏高原南部存在着冷湿—暖干的气候模式;过去2000年青藏高原南部地区温度的变化可能主要受到太阳辐射的影响,而小冰期期间西风环流的南移和增强可能是导致区域降水增加的重要因素。另外,该时期羊湖的湖泊水位的变化受温度和降水共同控制:当温度降低,降水增加时,湖泊水位上升,反之亦然。

关键词：元素地球化学青藏高原南部过去2000年中世纪暖期小冰期环境变化

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围栏封育对西藏甲玛湿地植物多样性影响分析

黑龙江畜牧兽医 2017年第5期 147-149,154页

作者：白玛玉珍任德智王瑞红潘刚周尧治西藏大学农牧学院西藏林芝860000

为了解甲玛湿地植物群落对围栏封育的响应,试验采用随机抽样法对甲玛湿地围栏内外植被生长状况进行调查。结果表明:围栏内有13科26属33种植物,围栏外有13科27属33种植物,物种组成及优势种差异很大,且围栏内以禾本科麦薲草(Elymus tangut... 详细信息

为了解甲玛湿地植物群落对围栏封育的响应,试验采用随机抽样法对甲玛湿地围栏内外植被生长状况进行调查。结果表明:围栏内有13科26属33种植物,围栏外有13科27属33种植物,物种组成及优势种差异很大,且围栏内以禾本科麦薲草(Elymus tangutorum)及菊科小球花蒿(Artemisia moorcroftiana)为优势种,围栏外以莎草科芒尖苔草(Carex doniana Spreng)及粗壮嵩(Kobresia robusta)为优势种。围栏内的生物量、高度、盖度、丰富度与优势度高于围栏外,而多样性指数与均匀度低于围栏外;且围栏内外植物群落的相似度较高,达0.708;各指数间相关性分析表明,均匀度是影响群落的多样性的重要因子,说明围栏封育对甲玛湿地植物影响较大。

关键词：西藏甲玛湿地围栏封育多样性优势种

高原地区股骨骨折患者下肢深静脉血栓超声诊断及高危因素分析

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西藏医药 2023年第2期44卷 19-22页

作者：李丹次旦旺久尼玛玉珍西藏自治区人民医院超声科西藏拉萨850000

目的探讨高原地区超声对股骨骨折患者的下肢深静脉血栓(DVT)诊断、分布情况及高危因素分析。方法回顾性分析2021年1月~2022年7月在西藏自治区人民医院诊断为股骨骨折,并且行骨科手术治疗的97例患者临床及双下肢静脉超声资料。超声提示... 详细信息

目的探讨高原地区超声对股骨骨折患者的下肢深静脉血栓(DVT)诊断、分布情况及高危因素分析。方法回顾性分析2021年1月~2022年7月在西藏自治区人民医院诊断为股骨骨折,并且行骨科手术治疗的97例患者临床及双下肢静脉超声资料。超声提示下肢深静脉血栓为A组(n=33),超声未提示下肢深静脉血栓为B组(n=64)。分析股骨骨折患者并发DVT的独立危险因素及A组下肢深静脉血栓分布情况。结果两组患者年龄、性别、吸烟史、糖尿病史、高血压史、骨折部位、术中失血量、凝血酶原时间、国际标准化比率、纤维蛋白原、D-二聚体、纤维蛋白降解产物在统计学上无明显差异(P>0.05),卧床时间、术前术后血小板差值在统计学上有明显差异(P<0.05)。Logistic回归分析发现下肢静脉曲张史、卧床时间、术前术后血小板差值是股骨骨折患者并发DVT的独立危险因素(P<0.05)。本研究中股骨骨折并发下肢深静脉血栓患者占比34.02%,主要分布在小腿肌间静脉、胫后静脉、股静脉。结论高原地区股骨骨折患者并发下肢深静脉血栓患者较内地多,DVT的发生与下肢静脉曲张、卧床时间、术前术后血小板差值密切相关,超声对下肢深静脉血栓灵敏度高、优势多,更适合高原下肢深静脉血栓患者。

关键词：血管超声股骨骨折深静脉血栓高原地区