玉龙铜（钼）矿带多霞松多岩体成因：锆石U-Pb年代学和岩石地球化学约束

玉龙铜(钼)矿带的成因机制和动力学背景一直存在争议。本文选择目前研究程度较低的多霞松多岩体, 对该岩体含矿斑岩开展岩相学、年代学、岩石地球化学及锆石Hf同位素分析。研究表明, 多霞松多岩体主要由二长花岗斑岩和碱长花岗斑岩组成, 其中, 二长花岗斑岩的主要造岩矿物为钾长石、斜长石和石英, 碱长花岗斑岩的主要造岩矿物为钾长石和石英。两种岩石属于高钾钙碱性-钾玄质侵入岩, 具有富碱高钾的特征; 亏损Nb、Ti等高场强元素, 富集Rb、Th、U等大离子亲石元素和Pb; 稀土元素含量较高(ΣREE=145.04×10^-6~290.91×10^-6), 富集轻稀土(LREE/HREE=6~37)。铕表现为从二长花岗斑岩的弱负异常(Eu/Eu^*=0.66~0.84)到碱长花岗斑岩的中等负异常(Eu/Eu^*=0.35~0.39)。锆石U-Pb定年显示, 二长花岗斑岩的成岩年龄为38.3±0.6 Ma, 碱长花岗斑岩的成岩年龄为37.8±1.0 Ma, 两者形成时代基本一致, 均属于喜马拉雅期, 表明在多霞松多地区始新世存在一期重要的岩浆热液Cu-Mo成矿事件。多霞松多含矿斑岩的锆石ε_Hf(t)范围在+1.3~+2.6之间。结合元素和同位素地球化学特征, 指示多霞松多含矿斑岩可能来源于亏损地幔分异的新生玄武质下地壳, 受控于印度板块与欧亚板块碰撞诱发的金沙江走滑断裂系统。

     

The simulation of LUCC based on Logistic-CA-Markov model in Qilian Mountain area,China

The Qilian mountain area was examined for using the Logistic-CA-Markov coupling model combined with GIS spatial analyst technology to research the transformation of LUCC, driving force system and simulate future tendency of variation. Results show that:(1) Woodland area decreased by 12.55%, while grassland, cultivated land, and settlement areas increased by 0.22%, 7.92%, and 0.03%, respectively, from 1986 to 2014. During the period of 1986 to 2000, forest degradation in the middle section of the mountain area decreased by 1,501.69 km~2. Vegetation cover area improved, with a net increase of grassland area of 38.12 km~2 from 2000 to 2014.(2) For constructing the system driving force, the best simulation scale was 210m×210m. Based on logistic regression analysis, the contribution(weight) of composite driving forces to land use and cover change was obtained, and the weight value was more objectively compared with AHP and MCE method.(3) In the natural scenarios, it is predicted that land use and cover distribution maps of Qilian mountain area in 2028 and 2042, and the Lee-Sallee index test was adopted. Over the next 27 years(2015–2042), farmland, woodland, grassland, settlement areas show an increasing trend, especially settlements with an obvious change of 0.56%. The area of bare land will decrease by 0.89%. Without environmental degradation, tremendous structural change of LUCC will not occur, and typical characteristic of the vertical zone of the mountain would remain. Farmland and settlement areas will increase, but only in the vicinity of Qilian and Sunan counties.     

Driving forces and their interactions of built-up land expansion based on the geographical detector – a case study of Beijing,China

Scientific interpretation of the driving forces of built-up land expansion is essential to urban planning and policy-making. In general, built-up land expansion results from the interactions of different factors, and thus, understanding the combined impacts of built-up land expansion is beneficial. However, previous studies have primarily been concerned with the separate effect of each driver, rather than the interactions between the drivers. Using the built-up land expansion in Beijing from 2000 to 2010 as a study case, this research aims to fill this gap. A spatial statistical method, named the geographical detector, was used to investigate the effects of physical and socioeconomic factors. The effects of policy factors were also explored using physical and socioeconomic factors as proxies. The results showed that the modifiable areal unit problem existed in the geographical detector, and 4000 m might be the optimal scale for the classification performed in this study. At this scale, the interactions between most factors enhanced each other, which indicated that the interactions had greater effects on the built-up land expansion than any single factor. In addition, two pairs of nonlinear enhancement, the greatest enhancement type, were found between the distance to rivers and two socioeconomic factors: the total investment in fixed assets and GDP. Moreover, it was found that the urban plans, environmental protection policies and major events had a great impact on built-up land expansion. The findings of this study verify that the geographical detector is applicable in analysing the driving forces of built-up land expansion. This study also offers a new perspective in researching the interactions between different drivers.     

辽宁省海洋经济系统协调发展研究

通过构建海洋经济系统协调发展评价指标体系,采用模糊数学中隶属度函数模型,分析了辽宁省海洋经济系统发展水平及其协调发展度.结果表明:1999-2010年期间,辽宁省海洋经济、社会综合发展水平逐年递增,而资源环境综合发展水平值波动较大;1999-2003年,辽宁省海洋经济系统协调性处于失调状态,2004年之后大体处于协调发展状态,且协调等级逐步提升.     

基于释光测年的福建晋江海岸沙丘粒度记录的风沙活动

采用OSL测年技术对福建晋江海岸沙丘剖面(SHA) 进行加密采样测年和粒度分析,初步确定了研究区近1000a 以来海岸沙丘发育的主要时段,以OSL测年值为基础,在统一时间标尺上综合对比东亚季风变化序列和福建沿海地区台风登陆记录,探讨了控制研究区海岸沙丘发育的主要因素.研究表明：(1) SHA沙丘表现为典型的海岸风成砂特征,海岸沙丘沉积后受风力侵蚀和后期化学风化作用的影响,粒径变粗,分选性变差,各粒级组分和粒度参数特征发生较大变化;(2) 近1000a 以来晋江海岸带海岸沙丘发育可划分为3 个时期,分别为AD1050~1300、AD1470~1600、AD1720~1950,尤其是小冰期(LIA),海岸风沙活动强烈,海岸沙丘发育盛行;(3) 近千年来区域降水量、海平面和台风强度变化与研究区海岸沙丘发育之间的关系尚不明确,而冬季风强度对海岸沙丘发育的影响明显,即海岸风沙活动期主要对应冬季风较强时期,但近50 年来海岸风沙活动较弱除了主要受冬季风减弱影响外,主要与人类经济活动所造成的地表覆被条件发生变化有关.     

The first extra-large helium-rich gas field identified in a tight sandstone of the Dongsheng Gas Field,Ordos Basin,China

Science China Earth Sciences - Helium gas is a scarce but important strategic resource, which is usually associated with natural gas. Presently, only one extra-large helium-rich gas field has been...     

气候变化对中国木本植物物候的可能影响

本文根据我国的３０年的物候资料和气候资料的统计分析，论证了气温是影响中国木本植物物候的主要因子，在此基础上建立了物候与年平均气温的线性统计模式，又利用此模式分析计算了未来全球年平均气温升高０．５－２．０℃和未来大气中ＣＯ２浓度倍增而增暖情况下，我国主要木本植物物候期的大致变幅。     

南极数值天气预报应用与研究进展

多个业务化的全球预报模式和有限区域预报模式应用于南极地区,已经成为南极天气预报和南极气候诊断研究的主要工具.现今南极地区的数值天气预报模式在模拟南极大气环流和天气系统方面性能不够理想,原因是多方面的:南极天气气候的特殊性(包括边界层的参数化、中尺度气旋等)、模式对南极复杂地形的描述不够充分、由于缺乏观测资料而使得模式的...     

Salinivibrio sp.YH4胞外丝氨酸蛋白酶EYHS耐盐性及生物信息学分析

摘要：目的 探讨菌株Salinivibrio sp.YH4分泌的丝氨酸蛋白酶EYHS的耐盐性及结构特征。方法 明胶底物酶谱法分析EYHS的耐盐性。应用生物信息学手段对EYHS及6种耐盐的S8家族丝氨酸蛋白酶结构特征进行分析。结果 EYHS在4 mol/L的NaCl溶液中仍具有活性,属于耐盐蛋白酶。EYHS及6种S8家族丝氨酸蛋白酶分子表面的loop区等无规则卷曲所占比例较高,α-螺旋与β-片层则主要位于酶分子内部。EYHS分子表面酸性氨基酸含量较高,且具有弱疏水内核。多序列比对发现蛋白酶的催化三联体两侧存在高度保守的基序和保守的极性氨基酸及芳香族氨基酸,并存在多个保守的Gly与Ala。同源模建和表面电荷分布显示,α螺旋和β片层围成了蛋白酶的催化腔,EYHS活性中心包含由Asp32、His65与Ser215组成的催化三联体,且催化位点区域表面静电势为负。结论 上述结构特征可能有助于耐盐丝氨酸蛋白酶EYHS在高盐环境下维持其稳定性和适度柔性,并有助于其催化功能的发挥,为深入研究耐盐丝氨酸蛋白酶的高盐环境适应性提供了一定的理论依据。     

青藏高原古人类的艺术创作——基于中更新世手脚印形态分析

在第二次青藏科考过程中,作者在西藏自治区拉萨市邱桑村的古泉华沉积上新发现了由5个手印和5个脚印组成 “岩面艺术” （parietal art）。对这一“岩面艺术”进行解剖学测量、3D 模型模拟、铀系测年和手脚印形态分析后,得到以下认识：① “岩面艺术”是在泉华没有成岩之前由古人类有意压上去的;② “岩面艺术”所在岩层的U/Th年代为226~169 ka B.P.,这其中包含一个手指印岩层的表面直接年龄（207~188 ka B.P.）;③ 这一发现是迄今为止发表的古人类在青藏高原上活动的最早记录之一,也为古人类适应高寒、低氧环境提供了新的证据;④ 此岩面艺术是目前世界上已知的最古老的艺术,上面的手印也是古人类留下的最早的手印;⑤ 这一原始的岩面艺术表明,创作它的古老人种可能具有一定的认知和空间感知能力,此岩面艺术的发现也将有可能改写人类艺术史,并且加深我们对已消失的古人类认知水平的认识。