A preliminary study of chronology for a newly-discovered ancient city and five archaeological sites in Lop Nor,China

In the past century, it has long been debated in the archeological, historical, geographical, and many other related communities where the capital of the Luolan and Shanshan states was in the Lop Nor region. This paper presents three AMS radiocarbon ages from a newly-discovered ancient city at about 6.3 km to the northwest of the Xiaohe Graveyard, and fifteen new radiocarbon ages from the Loulan (LA), LE, Qieerqiduke, Milan, and Tuyin sites in Lop Nor. The new investigation shows that the age of newly-disco...     

Relationships between tree-ring width index and NDVI of grassland in Delingha

The responses of terrestrial ecosystem to and their impacts on global climate change are key issues in global change research. More studies on vegetationmonitoring and land cover change have been performed by using remote sensing data recently, which bene…     

A 16000-year pollen record of Qinghai Lake and its paleo-climate and paleoenvironment

The paleoclimate and paleoenvironment of Qinghai Lake indicated by a 16000-year pollen record are as follows. It was very cold and dry before 15200 years. During the Late Glacial, the climate varied from colder and semiarid to cool and semi-humid and fluctuated frequently but with little amplitude. Three cold events in the periods of 13400–13000, 11600–12000, and 11000–10400 aBP respectively correspond to the Oldest Dryas, Older Dryas and Younger Dryas events, whereas the two warm periods between them, 12000–13000 and 11600–11000 aBP, respectively correspond to Bölling and Alleröd periods. The temperature increased abruptly after the Younger Dryas event, and then the climate gradually turned to be warm and wet from warm and semiarid. In the Holocene, the largest amplitude of cold event that occurred at ca. 8200 aBP is quite prominent. The Holocene climatic optimum culminated at 6700 aBP. After 2100 aBP, the climate tended to be cold and dry, keeping on up to now. Palaeoclimatic evolution and events of Qinghai Lake based on pollen assemblage and concentrations can be well parallel with the global climatic events.     

陇县地区新街片麻岩套锆石年龄及其地质意义

目的寻找秦-祁结合部位早古生代岛弧型岩浆活动的证据,为秦岭和祁连造山带的对比研究提供依据。方法依据岩石主、微量地球化学特征判别新街片麻岩套的构造属性,并通过LA-ICP-MS对其中的锆石进行U-Pb测年。结果新街片麻岩套富集大离子亲石元素(LILE)和轻稀土元素(LREE),亏损高场强元素(HSFE)和重稀土元素(HREE),指示其形成与俯冲作用有关,在构造判别图解中落入岛弧火山岩范围;U-Pb锆石测年结果显示,花岗质片麻岩的形成年龄为447.7±5.4Ma。结论该年龄与北秦岭和北祁连造山带内部的岛弧火山岩活动的时限一致。     

伪牛顿信赖域算法及其收敛性

本文提出了一类新的求解无约束最优化问题的信赖域算法.新算法将Goldstein线搜索技术与信赖域方法相结合,并通过伪Newdon-δ族校正公式计算信赖域子问题中的Bk,使算法不仅不需重解子问题,而且每步迭代都满足弱拟牛顿方程,保证了目标函数的近似Hesse阵Bk的正定性.在适当的条件下,证明了此算法的全局收敛性和Q-二...     

桃山-诸广铀成矿带成岩成矿年代学研究进展

桃山-诸广铀成矿带是中国重要的花岗岩型铀成矿带,产铀花岗岩体主要有桃山复式岩体、诸广山复式岩体(南部)、贵东复式岩体(东部)。对铀成矿带内近年来与铀成矿关系密切的花岗岩、基性岩和铀矿化作用的年代学数据进行收集,总结带内成岩成矿年代学研究进展,进而分析存在的主要问题。统计结果表明,近年来高精度的年代学数据一定程度上提高了年代学的精度,促进了对花岗岩、基性岩与铀成矿关系的认识。但是,带内年代学数据主要存在以下问题:(1)花岗岩锆石U-Pb测年结果存在数据偏少、平均标准权重偏差(mean squared weighted deviation, MSWD)高、高铀数据未剔除等问题,且不能为复式岩体的时序的厘定提供依据;(2)基性岩脉多采用Ar-Ar法(易受后期蚀变或热时间影响)和高精度U-Pb法(基性岩浆往往难以结晶出大量锆石);(3)铀成矿年龄测试方法易受检测限、标准样品、高铀效应的影响。综上所述,尽管近年来高精度年代学深化了对铀成作用的认识,但是年代学的测试方法、数据处理等方面仍需要解决。     

A new cheirolepidiaceous conifer from the Early Jurassic of the Junggar Basin, northern Xinjiang and its paleoclimatic implications

Mesozoic sediments are extensively developed in the vast area of Xinjiang and Jurassic strata are well exposed in the Junggar Basin. The Haojiagou geological section near Urumqi in the south of the basin is a typical section for the Lower Jurassic Badaowan and Sangonghe formations. The cheirolepidiaceous conifer Brachyphyllum (Hirmeriella?) sp., which exhibits strongly xeromorphic characters, was discovered in the Sangonghe Formation and is associated with a high relative abundance (up to 75%) of dispersed Classopollis pollen. The occurrence of cheirolepidiaceous foliage and Classopollis pollen in the Sangonghe Formation indicates that a warm and dry climate prevailed in the Junggar Basin during the Early Jurassic (Early Toarcian), supporting the hypothesis for a warming event at that time.     

A new cheirolepidiaceous conifer from the Early Jurassic of the Junggar Basin, northern Xinjiang and its paleoclimatic implications

Mesozoic sediments are extensively developed in the vast area of Xinjiang and Jurassic strata are well exposed in the Junggar Basin. The Haojiagou geological section near Urumqi in the south of the basin is a typical section for the Lower Jurassic Badaowan and Sangonghe formations. The cheirolepidiaceous conifer Brachyphyllum (Hirmeriella?) sp., which exhibits strongly xeromorphic characters, was discovered in the Sangonghe Formation and is associated with a high relative abundance (up to 75%) of dispersed Classopollis pollen. The occurrence of cheirolepidiaceous foliage and Classopollis pollen in the Sangonghe Formation indicates that a warm and dry climate prevailed in the Junggar Basin during the Early Jurassic (Early Toarcian), supporting the hypothesis for a warming event at that time.     

A preliminary knowledge-driven prediction model of snail distribution in the Poyang Lake region

Present monitoring and prediction of schistosomiasis＇s intermediate parasite, snail, are based on remote sensing image＇s spectral signatures, and the calculation result is in fact an incomplete-constraints solution. TM image of the Poyang Lake region on October 31, 2005 was combined with GIS thematic data （DEM, boundary of the Poyang Lake, vegetation, soil and land use） to make a prediction on snail spatial distribution in the region by remote sensing, geo-informaUcs and knowledge-driven modeling according to mechanism of snail occurrence. Result shows that with change of overall fuzzy membership of snail occurrence from high to low, snail occurrence of the snail samples of validation group goes up to 81% within 10% high fuzzy membership range, denoting high efficiency of the model in predicting snail occurrence.     

A preliminary knowledge-driven prediction model of snail distribution in the Poyang Lake region

Present monitoring and prediction of schistosomiasis’s intermediate parasite, snail, are based on re-mote sensing image’s spectral signatures, and the calculation result is in fact an incom-plete-constraints solution. TM image of the Poyang Lake region on October 31, 2005 was combined with GIS thematic data (DEM, boundary of the Poyang Lake, vegetation, soil and land use) to make a prediction on snail spatial distribution in the region by remote sensing, geo-informatics and knowl-edge-driven modeling according to mechanism of snail occurrence. Result shows that with change of overall fuzzy membership of snail occurrence from high to low, snail occurrence of the snail samples of validation group goes up to 81% within 10% high fuzzy membership range, denoting high efficiency of the model in predicting snail occurrence.     

黄石地区野生藤本植物资源及其利用

黄石地区野生藤本植物有84种(含4变种),隶属于55属27科。概述了黄石野生藤本植物资源的分类和主要形态特征,并为其综合利用提出了初步建议。     

Rock magnetic studies on the hominoid-bearing sediments at Zhupeng, Yuanmou Basin, southwestern China and its paleoclimatic significance

It has been proposed that paleoclimatic changes and tectonic events strongly affect hominoid evolution. The Zhupeng section at Yuanmou Basin, southwestern China, with the hominoid-bearing fluvial-lacustrine sediments, is an ideal natural laboratory to test this hypothesis. This study provided an integrated magnetic study, including low-frequency susceptibility, the anisotropy of magnetic susceptibility, temperature-dependent susceptibility, hysteresis loops, isothermal remanent magnetization, and anhysteretic remanent magnetization, on samples from the Baozidongqing section at Zhupeng. Results show that the dominant mag- netic carrier is hematite, with minor amount of magnetite. Both the composition and concentration of magnetic miner- als strongly correlate with the lithostratigraphy. At least eight short-term events defined by higher concentrations of magnetite were identified. These short events reflect that the subtropical dry-hot climate is similar to today＇s climate. Basing on the lithostratigraphic and rock magnetic results, we suggest that Yuanmou Basin was in a steady deposition environment from about 11 to 7 Ma, which is characterized by alternating of long-term torrid-humid climate and short-term dry-hot climate. Our study provides invaluable environment information for understanding the climate shift and the relationship between paleoenvironment and hominoid evolution in southwestern China during late Miocene.     

Present-day crustal movement in China continent and its southeast coast region

Based on the observations of global positioning system (GPS) , a movement model for quantitatively describing the seven continent blocks in China, Tibet, Sichuan-Yunnan, Gansu-Qinghai, Xingjiang, the South China, the North China and Heilongjiang is established, and the derived velocity field (1994—1996) is consistent with the focal mechanism " P" stress axis field and the geological model on the whole. China continent moves toward east (including N\E, NE, E, EES and ES) . Furthermore, the intrablock deformation model for Fujian and its neighboring sea region is also established. The derived velocity field and strain rate field (1995—1997) show that along with the southeast coastal region, the whole China moves toward southeast. There are compression from sea to continent in the northwest direction and extension in the northeast direction. The direction of principal stress axis at present is NW (NWW) SE (SEE) . The collision of India plate with Eurasian plate plays a major role in the crustal movement of China continent, while the collision and pushing of Philippine plate play the direct and important role in the crustal movement and strong earthquake gestation in the southeast eoastal region of China continent.     

石春一号的育成及其性状分析

农学系作物育种教研组以青春5号为母本,赛洛期为父本,于1975年进行成对杂交,经过多代南繁北育,用系谱法选育而成的春小麦品种“石春一号”,是本院育成的第一个作物新品种,该品种春性,中性;幼苗直立,茎杆粗壮,株型紧凑,耐肥抗倒;分蘖力及成穗率中等。穗大粒多,千粒重稍低;综合抗凉能力较好,蚜虫危害较轻;有一定耐旱、耐瘠及抗干热风的能力;籽粒角质,容重高,蛋白质含量中上,赖氨酸含量较高,本品种属于产量高而稳定的类型,宜在气候较冷凉地区推广。育种实践表明,选择在当地表现优良的亲本进行杂交,是育成新品种的基础;南繁加代是加速春麦育种进程的有效措施;边测产,边选择,边加代,边扩繁是促进品系稳定一致,并及时获得较多原种的可行办法。     

新疆和田地区土地沙漠化原因及其对策分析

土地沙漠化是全世界共同面临的一个重大的环境与社会经济问题.新疆和田地区自然条件恶劣,生态环境脆弱,环境灾害多发,土地沙漠化不断加剧,沙进人退的形势日趋严峻,严重制约着当地经济和社会的可持续发展.文章从多个侧面阐述了该地区土地沙漠化的原因,并提出了相应的对策和建议.     

山东早期城市群及其与环境关系研究

目的为了深入研究山东早期城市群的形成和发展规律及其与环境的相互关系。方法在野外实地考察及查阅有关文献资料的基础上,运用定性描述与定量分析相结合的手法,结合现代城市地理学中的相关理论进行探讨。结果揭示了山东早期城市群分布、发展的一般规律及其与环境的关系。结论区域自然环境、人文环境,尤其是早期政治地缘结构演变是影响区域城市群发展的关键性因素;早期城市群的形成与发展改变着区域的环境特征。     

青海哈西亚图多金属矿床地质特征及成因探讨

为了加快青海省优势环境与战略矿产勘查进程,文中对哈西亚图多金属矿床成矿地质背景、矿床地质特征、控矿因素及成因进行了综合分析,研究结果表明:哈西亚图多金属矿床已发现矿体的成因类型为矽卡岩型,矿体从垂向上看,可分为4层均产于具垂直分带的矽卡岩带中,受矽卡岩类型影响矿石类型在垂向上也具有明显分带性,在华力西期花岗闪长岩与古元古界金水口岩群的碳酸盐岩的接触带附近为主要成矿部位,通过早期区域变质作用、矽卡岩化作用及晚期的热液成矿作用3个阶段,形成了以磁铁矿体为主,铜、铅、锌、金并存的多金属矿床。     

青海省农民对灌溉水管理的认知与评价调查——以都兰、贵德、大通三县为例

以青海省柴达木盆地都兰县、黄河干流贵德县、湟水流域大通回族土族自治县为研究区域,进行了农民对灌溉水管理认知和评价的问卷调查研究.结果表明：三县农民对水价高低的感知和评价与实际水价紧密相关,农民认可按灌溉面积计收水费的收费方式;农民认为灌区管理机构的主要职能是维护好渠道、指导农民科学用水、制定合理的分水计划,灌区管理机构在渠道维护、水费使用透明度、宣传国家水管理政策等方面需要改进;农民还认为村集体在水管理事务民主化与公开化、组织领导作用等方面存在不足.最后提出了青海省灌溉水管理改革的建议.