Comparison of paleoclimatic characteristics between monsoon and westerly areas, China

For past decades there have been many studies on the climate features during the last interglacial and glacial periods. A comparison between the loess record of western China with that of monsoon areas shows some regional differences. ( i) Generally, the climate of the Yili region since the late Pleistocene was dry, with fluctuations. Late Pleistocene climate change in the study area can be divided into 5 stages, corresponding to 5 marine isotopic stages (MIS 1-MISS), (ii) Evidence from grain size composition, magnetic susceptibility, carbonate content, pollen assemblage and geochemistry shows that the climate during the last glacial period was instable. During MIS4 the westerly winds were strong and the humidity was relatively high. Compared with the early stage, MIS2 was dry. In MIS3, westerly winds were relatively weak; pedogenesis prevailed, forming paleo-sols. (iii) In contrast to the Loess Plateau the deposition rate of dust at the early stage was higher than at the late stage of the last galical in the Yili region. The strongest wind event occurred at about 24 kaBP instead of 18 kaBP. (iv) Variations in the grain size indicate that the westerly winds decreased since the deglaciation, but dust accumulation continued until the late Holocene. High carbonate contents, low ratio of Rb/Sr and lack of soil development imply that the climate was dry during the early and middle Holocene. Since the late Holocene the climate became relatively wet and the soil was developed.     

Loess-soil sequences in southern Anhui Province： Magnetostratigraphy and paleoclimatic significance

Two parallel loess-soil sequences from Xuancheng and Fanchang in southern Anhui Provinces are dated using geomagnetic and luminescence methods.The Brunhes/Matuyama(B/M) reversal boundary is recognized within the lower part of the so-calles Vermiculated Red Soil (VRS) in the Xuancheng section while the entire Fanchang sequence is of Brunhes age.This indicated that the most recent VRS in southern China,a stratigraphic marker and an indication of extremely warm-humid conditions,was formed during the middle Pleistocene,chronologically correlative with the S4 and S5 soil units in northern China.Microscopic and sedimentologic in vestigations reveal that eolian deposition started in this region at about 0.85 MaBp,roughly synchronous with the well-known Mid-Pleistocene climate change of global significance.The strengthening of both summer and winter monsoon circulations and the consequent river hydrological changes at that time would have provided favorable conditions for sustained eolian deposition in the middle-lower reaches of the Yangtze River since 0.85 MaBP.     

广西崇左市白头叶猴保护区土壤研究

在现代的南亚热带高温多雨的气候作用下,赤红壤继续处于高度淋溶状态而发育成盐基高度不饱和,酸性较强,有机质量较低,土壤肥力较差;而处于岩溶山地的坡麓和谷地中的红粘土,因受山上的富含钙镁的岩溶水淀积复钙和淋溶脱钙的反复作用发育形成红色石灰土或复钙红粘土.这在广西崇左市白头叶猴保护区区的濑湍片、板利片和岜盆片的峰林谷地中和河...     

黄土工程力学性质的变化及控制因素

研究了黄土工程力学性质的变化及控制因素，由黄土与红色古土壤工程力学实验资料表明，黄土的承载力、压强度与抗剪强度小于红色古土壤，这是它们经受了不同成壤作用的结果，通过分析实验得出粘化作用强，土壤力学强度大，粘化作用弱，土壤力学经度小，黄土地层工程力学性质在垂向上具有明显波动变化规律，这种变化是黄土与红色古土壤发育时冷干与温湿气候的交替变化造成的。     

基于VRS技术的GPS接收系统设计与实现

介绍了虚拟参考站系统的组成、工作原理及优势，并研究开发了一套基于VRS技术的GPS接收系统．该系统由单片机、AC12 GPS模块、GSM模块、键盘模块、液晶显示模块和U盘存储模块等组成，可接收以GSM方式发送的GPS差分信息，并对差分后的位置数据进行存储和显示．试验表明：设计研发的系统工作稳定，采用VRS差分后定位精度达到1．25m（95％），能满足精细农作管理的基本要求，适用于农田信息采集、面积测量等多种作业．     

岩溶气爆塌陷的数学模型探讨

通过对已有岩溶气爆塌陷实例的分析 ,提出了气爆塌陷的三个发育阶段 ,分别为正压形成阶段、土层破坏阶段、气压快速释放及塌陷阶段。根据岩溶空腔的发育特征 ,用波马气体方程式对水位恢复时气爆效应中所产生的附加力进行了描述 ,并提出了气爆塌陷的发育条件 ,还对正压气爆中土层的最大安全厚度进行了讨论。     

江西东北部低山区的土类组合

<正>江西省东北部低山区的森林土壤,按我国现行土壤分类系统应归入红壤和黄壤;但是,实际上坡地中部以上的黄棕色土壤与上述红壤或黄壤的概念不符。以赣东北与南京近郊低山区几个土壤剖面的数据作出极小生成树图,可见赣东北低山坡地下部的红色土壤与中部以上的黄棕色土壤,是属于截然不同的两类。后者在性质上与南京低山坡地下部的、具有埋藏红层的土壤剖面接近,但二者成因不同。南京近郊低山坡地的土壤组合,自上而下为薄层土(性质近似于山东棕壤)和黄棕壤(老红土上发育的);而赣东北低山坡地的土壤组合,自上而下为黄棕壤(近代发育的黄棕色土壤)和红壤(古风化壳上发育的)。     

The worm-shaped veins in the red earth of South China--Pedological evidence for root traces of past forest

Field observation of the macromorphology and analyses of micromorphology and geochemistry were conducted to the worm-shaped veins (WSVs) in the red earth of South China.The WSVs exhibit outward features of root traces and contain the traces of stele that can be used as the definite evidence of root traces.Surrounding the worm-shaped veins there are some micro-features pressed by past root growth.Geochemical analyses indicate that the white part in the WSV was depleted in Fe content.These lines of evidence suggest the WSVs in the red earth of South China are the root traces of past forest.     

The worm-shaped veins in the red earth of South China——Pedological evidence for root traces of past forest

Field observation of the macromorphology and analyses of micromorphology and geochemistry were conducted to the worm-shaped veins (WSVs) in the red earth of South China. The WSVs exhibit outward features of root traces and contain the traces of stele that can be used as the definite evidence of root traces. Surrounding the worm-shaped veins there are some micro-features pressed by past root growth. Geochemical analyses indicate that the white part in the WSV was depleted in Fe content. These lines of evidence suggest the WSVs in the red earth of South China are the root traces of past forest.     

大厂凹陷MIS3阶段以来沉积物地球化学特征分析

深海氧同位素3-1阶段是指深海沉积物有孔虫氧同位素记录的第四纪末次冰期至冰后期的一个时期,期间气候表现为间冰阶、极端寒冷、多次千年尺度气候事件至最后转暖多个变化特征,相关气候变化沉积响应及影响因素等科学问题一直以来备受关注。然而,该时期相关千年尺度气候事件的记录及讨论在华北平原地区仍有争议,为探讨华北平原西北地区在该阶段的气候特征,本研究在大厂凹陷区天然剖面进行高密度碳14断代样品测试,并开展常量和微量元素地球化学含量分析,获得地球化学数据变化趋势特征,结果表明,该剖面年代从32.5ka至8.2 ka,处于深海氧同位素3阶段末期至深海氧同位素1阶段早期。在该时段,主量元素氧化物TFe2O3、Al2O3、SiO2、MgO、CaO、Na2O与K2O与微量元素Sr、V、Ni、Co、Ga、Cu、Ba、Cr和Zn均呈现一致的变化趋势;在MIS2末次冰盛期和MIS1早期中的B?lling-Aller?d暖期和新仙女木冷期,K/Na、Al/Na、化学蚀变指数 、化学风化指数 和古温度等指标与东亚季风区气候呈现一致的变化,同时与全球尺度的事件具有同步性,因此认为晚更新世晚期华北平原的气候变化可归因于全球气候系统下东亚季风区的演化。     

High-resolution climate evolution derived from the sediment records of Erlongwan Maar Lake since 14 ka BP

Varve counts with AMS 14 C,137 Cs and 210 Pb dating of sediments(0-900 cm) from Erlongwan Maar Lake,NE China were used to establish a high-resolution chronology series for the late Quaternary.Dry density,total organic carbon(TOC) content,total nitrogen(TN) content,TOC/TN ratios and stable organic carbon isotope(13 C org) ratios were continuously analyzed on this sediment profile.On the basis of lithological characters,sporo-pollen assemblages and geochemical analyses,we identified 6 climate stages within the last 14 ka BP.The time before the Holocene(14-11.4 ka BP) represents a higher-order oscillation climatic transitional period(I).The entire Holocene climate development(from 11.4 ka BP to present) exhibited an increasing temperature trend,although there were cold and warm alternations(II-VI).The periods included were:II(11.4-9.05 ka BP) warm-wet stage,III(9.05-7.4 ka BP) cold and warm fluctuation stage,IV(7.4-4.2 ka BP) smoothly warming climate stage,V(4.2-1.67 ka BP) climate optimum stage,and VI(from 1.67 ka BP to present) cool and drier stage.Each climate stage began with a warming event and ended with an abrupt cooling event.This climate change cycle had unequal time spaces that were progressively shorter over time.Several abrupt climate shifts occurred at about 9.4-9.05,8.5-8.2,7.8-7.4,4.6-4.2,3.7-3.25,2-1.67 and 0.3-0.03 ka BP.Thus,it can be seen that the climate has been warming since 1920 AD,which indicates a new climate stage.     

黄土物理性质变化规律研究

研究了黄土孔隙度和湿陷性在垂向上变化的规律和原因 .结果表明 ,孔隙度高和湿陷强的层位是风化成壤弱的黄土层 ,孔隙度低和湿陷弱的层位是红色古土壤或风化成壤强的黄土层 .第四纪冷干与温湿气候的交替和由此产生的成壤过程的变化是造成黄土地层孔隙度和湿陷性波动变化的根本原因 .黄土湿陷性是在干旱与半干旱地区弱的成壤过程中产生的 ,是草原地带灰黄色土壤具有的特征 .     

彩叶桂叶片发育过程中叶色表型与色素成分变化

【目的】探究彩叶桂叶片发育过程中叶色表型与色素成分的关系。【方法】以彩叶桂品种‘虔南桂妃’(Osmanthus fragrans‘Qiannan Guifei’)5个发育时期(S1—S5)的叶片为研究对象,选用英国皇家园艺学会比色卡和色差仪测量其叶色表型,同时采用可见光分光光度法对5个时期的叶片进行叶绿素和类胡萝卜素的测定,利用超高效液相色谱-串联三重四级杆-飞行时间质谱(UPLC-Triple-TOF/MS)联用技术定性定量分析叶片中类黄酮成分与含量,进一步分析了叶色与各色素成分之间的相关性。【结果】随着叶片不断发育,彩叶桂叶片颜色变化大致分为两个阶段：第1个阶段由红转黄(S1—S3),第2个阶段由黄转绿(S3—S5)。叶片颜色参数明度L^*值和蓝度b^*值先增加后下降,而红a^*值和彩度C^*值则呈下降趋势。在叶片中共鉴定出了8种类黄酮,包括1种花青素(Cy3R)、3种黄酮(Ap7G、Ap7R和vicenin-2)以及4种黄酮醇(Km3R、Km7G、Km3G7R、Qu3R)。定量分析发现：叶绿素和类胡萝...     

灵璧石形成的地质环境及其主要地质特征研究

在野外实地调查的基础上,通过一定的岩样、水样分析,从纹理、色彩、音韵、质地和形体等要素方面分析了灵璧石的主要特征;通过对灵璧石的分布层位、地形特征、盖层条件、气象水文条件、地下水条件等的综合分析研究,认为灵璧石是在特定的地质环境条件下形成的,且具有区别于其它观赏石的独特地质特征,主要表现在微细粒结构、主要矿物成份为方解石、硬度中等、纹理变化多样、颜色以黑、红、白为主等方面,具有很好的观赏和科学研究价值.     

气候变化和人类活动对汀江径流变化的贡献

基于汀江流域控制站溪口站19652012年日均径流量实测数据及长汀、上杭、永定气象站逐日降水、逐日气温资料，采用年段均值比较、5a滑动、趋势线分析和累积距平等方法，对流域近50年来的径流量序列进行分析，揭示径流量变化的趋势，判别径流量变化存在的2个突变年份，划分径流量变化的3个阶段. 应用改进后累积量斜率变化率比较法（SCRCQ）定量估算了近50年来气候变化和人类活动对汀江径流量变化的贡献率. 结果表明:（1）径流量总体呈现下降上升下降的波动，判别突变年份为1972、2001年，划分径流变化3个阶段为19651972年(A阶段)、19732001年(B阶段)、20022012年（C阶段）；（2）与A阶段相比，B、C阶段气候变化对径流量变化的贡献率分别为65.1%、50.5%，而人类活动对径流量变化的贡献率为34.9%、49.5%，可见人类活动对径流量变化贡献日趋突出.     

中国泥石流形成,发展,分布与自然环境演变间的关系

根据泥石流发育条件的形成规律与自然环境演变规律之间的关系分析,泥石流物质来源主要积累于物理风化盛行的冰期或冰缘气候环境阶段,水动力条件主要出现在融冰雪水或降水骤增时间——即间冰期或间冰缘期(阶)气候环境阶段.庐山、北京西山和燕山都反映出这种规律性,以马兰期黄土层为标志,晚更新世晚期至少有2期泥石流堆积,全新世有4期泥石沉堆积.从而划分出泥石流发育的活跃期和停滞期,目前中国泥石流仍处活跃期,即相当于间冰期阶段.按中国泥石流发育条件形成与自然环境演变规律间的关系,中国泥石流发育系统有3种结构模式,即西部高山型,北方冰缘型,南方霜冻型.再按气候差异,绘出了中国泥石沉分区图.     

翟永明诗歌中的“黑一白”辩证法

翟永明是后朦胧诗和女性诗歌的代表诗人。她的诗歌总的来说,可以分为两个时期,即“黑色时期”和“白色时期”。她黑色时期的诗歌大量地运用黑色意象群,并大量地抒写梦幻,从女性的视角来观察女人的命运;她白色时期的诗歌则大量地运用白色意象群,从一个完全不同的视角来看待一切。总之,翟永明前后期的诗歌,由于采用了独特的视角、个人化的思考以及独特的表现手法,因此她的诗歌获得了一种美学上的独特力量。     

我国南方岩溶山区环境特点及对道路工程水土保持的影响分析

从道路工程建设水土保持角度对我国南方岩溶山区环境特点进行系统分析,认为该岩溶山区的特殊地形和地表结构,以及山地型亚热带气候的基本特征,有别于其他区域,是影响道路工程水土保持的重要因素和方面,该环境对工程土石方平衡、工程占地、工程措施布设等产生特殊影响,增加了该区域道路工程水土保持的难度和工程量。     

高温灭菌酸性红壤可能诱发其对烟草幼苗的锰毒害

以存在烟草连作障碍的两种土壤(红壤和水稻土)为材料,研究高温灭菌对幼苗期烟草鲜干质量、农艺性状和土壤理化性状的影响.结果显示:(1)酸性红壤土高温灭菌后,烟草植株干质量、株高、茎粗和叶面积,均显著低于不灭菌处理;然而,碱性水稻土高温灭菌后,上述参数值则恰恰相反.(2)高温灭菌,显著降低了红壤土Eh值,可能是导致土壤二价锰质量分数超过了烟株锰毒害临界值的因素之一,但高温灭菌对水稻土pH值和Eh值影响均无统计学意义.据此,在进行土壤生物学障碍机理研究时,应该考虑高温灭菌诱发酸性红壤锰毒,抑制烟株生长,从而影响对试验结果的客观评价.     

不同花色品种蝴蝶兰花色素苷含量分析及相关基因表达研究

分析红色、黄色、粉紫色和白色蝴蝶兰品种不同开放度的花和叶花色素苷生物合成途径7个结构基因PAL、4CL、CHS、DFR、F3H、F3'5H和ANS基因和3个调节基因的表达.结果显示:10个基因的表达因不同花色、不同发育阶段而异.这10个基因在叶中的表达量相对花较低.黄金甲中PAL、4CL、CHS、F3H、F3'5H基因的表达量均较高,PAL、4CL、CHS和F3'5H在开花期达到峰值,粉色花空港红鹰花DFR、CHS、F3H、F3'5H表达量较高.白色花空港枫叶和黄色花富乐夕阳花中CHS、DFR、F3H、F3'5H和ANS表达量较低.CHS在6个品种花的不同阶段皆有表达.F3H基因在6个品种中表达量较低,与花色素合成不存在直接相关.调节基因b HLH 6个品种各发育阶段的表达量均较高,MYB表达量较低,这些结果表明,蝴蝶兰花色素苷积累是CHS、F3'5H、DFR和ANS等关键结构基因共同表达的结果,编码转录因子b HLH基因的表达可能在花色形成中作用较大.