中中新世中亚构造抬升驱动气候干旱化：以塔里木盆地东南缘江尕勒萨伊剖面为例

中亚前陆盆地地层中氧同位素和孢粉,以及黄土高原和北太平洋粉尘记录均表明,中中新世(16~12 Ma)中亚地区气候干旱化显著增强。然而,对其驱动机制的认识不一,包括全球降温、中亚地区的构造抬升、高海拔的"原西藏高原"的存在、副特提斯洋的退缩以及上述几者联合作用的结果。不过,全球降温(约14 Ma)、"原西藏高原"的抬升(≥40 Ma)、以及副特提斯洋退缩的时间(34 Ma)与中中新世中亚气候干旱化增强的时间(16~12 Ma)不一致。因此,它们可能是导致中中新世中亚干旱化增强的重要边界条件,或者是有利的辅助条件,但没起直接的主导作用。对塔里木盆地东南缘江尕勒萨伊剖面的前期研究结果表明,阿尔金山快速抬升始于16 Ma。在获得了磁性地层年龄的基础上,前人的碳氧同位素数据指示了16 Ma江尕勒萨依地区气候干旱化逐渐增强。鉴于同时发生,笔者把16 Ma气候干旱化增强归因于此时阿尔金山的快速抬升。从更广范围看,中中新世中亚发生了广泛的的地壳缩短变形和造山运动。对中国黄土高原的红粘土以及北太平洋粉尘沉积的多指标分析(磁化率、粒径、粉尘通量以及物源等)表明,中中新世中亚构造抬升及其引起的雨影效应是中亚气候干旱化增强的主因。     

Arsenic Distribution Pattern in Different Sources of Drinking Water and their Geological Background in Guanzhong Basin,Shaanxi, China

To study arsenic(As) content and distribution patterns as well as the genesis of different kinds of water, especially the different sources of drinking water in Guanzhong Basin, Shaanxi province, China, 139 water samples were collected at 62 sampling points from wells of different depths, from hot springs, and rivers. The As content of these samples was measured by the intermittent flowhydride generation atomic fluorescence spectrometry method(HG-AFS). The As concentrations in the drinking water in Guanzhong Basin vary greatly(0.00–68.08 μg/L), and the As concentration of groundwater in southern Guanzhong Basin is different from that in the northern Guanzhong Basin. Even within the same location in southern Guanzhong Basin, the As concentrations at different depths vary greatly. As concentration of groundwater from the shallow wells(50 m deep, 0.56–3.87 μg/L) is much lower than from deep wells(110–360 m deep, 19.34–62.91 μg/L), whereas As concentration in water of any depth in northern Guanzhong Basin is 10 μg/L. Southern Guanzhong Basin is a newly discovered high-As groundwater area in China. The high-As groundwater is mainly distributed in areas between the Qinling Mountains and Weihe River; it has only been found at depths ranging from 110 to 360 m in confined aquifers, which store water in the Lishi and Wucheng Loess(Lower and Middle Pleistocene) in the southern Guanzhong Basin. As concentration of hot spring water is 6.47–11.94 μg/L; that of geothermal water between 1000 and 1500 m deep is 43.68–68.08 μg/L. The high-As well water at depths from 110 to 360 m in southern Guanzhong Basin has a very low fluorine(F) value, which is generally 0.10 mg/L. Otherwise, the hot springs of Lintong and Tangyu and the geothermal water in southern Guanzhong Basin have very high F values(8.07–14.96 mg/L). The results indicate that highAs groundwater in depths from 110 to 360 m is unlikely to have a direct relationship with the geothermal water in the same area. As concentration of all reservoirs and rivers(both contaminated and uncontaminated) in the Guanzhong Basin is 10 μg/L. This shows that pollution in the surface water is not the source of the high-As in the southern Guanzhong Basin. The partition boundaries of the high- and low-As groundwater area corresponds to the partition boundaries of the tectonic units in the Guanzhong Basin. This probably indicates that the high-As groundwater areas can be correlated to their geological underpinning and structural framework. In southern Guanzhong Basin, the main sources of drinking water for villages and small towns today are wells between 110–360 m deep. All of their As contents exceed the limit of the Chinese National Standard and the International Standard(10 μg/L) and so local residents should use other sources of clean water that are 50 m deep, instead of deep groundwater(110 to 360 m) for their drinking water supply.     

星球绅士化理论前沿及其对中国城乡治理的启示

绅士化已经成为全球城乡发展研究的前沿问题。探究绅士化的理论及其对中国城乡治理的启示,对贯彻落实新型城镇化和乡村振兴的国家战略具有重要意义。通过理论分析和案例比较可见,星球绅士化突破了传统绅士化研究的本体论、认识论和方法论,全球北方与全球南方的差异凸显了中国绅士化研究的价值。结合中国独特的城乡关系、央地关系及其多尺度交互作用,可进行星球绅士化的理论创新。未来中国城乡治理应重视治理模式转型、区域战略转型和城乡关系转型,全球经验、区域差异、城乡融合是治理现代化转型的关键点。对绅士化现象须采取批判性的价值论立场,关注城乡中低收入者权利,为维护空间正义和实现共同富裕做出积极贡献。中国绅士化研究需要加强与国际的对话与对接,并提供本土化经验。     

“双碳”目标下长江中游城市群生态福利绩效演变及驱动机制研究

生态福利绩效是探析自然生态与人类福利关系、衡量生态文明建设的重要工具。论文运用Super-SBM模型测度2005—2020年长江中游城市群市域尺度生态福利绩效,在识别其时空演变特征的基础上,运用面板Tobit模型探讨驱动生态福利绩效演变的因子,最后在“碳达峰、碳中和”目标下揭示其演变的驱动机制。研究发现： ① 2005—2020年长江中游城市群生态福利绩效呈现出“缓慢衰退→波动→快速发展”的演变特征;② 长江中游城市群生态福利绩效总体上呈“核心—外围”态势,武汉城市圈、环长株潭城市群、环鄱阳湖城市群交界处“中部塌陷”特征明显;③ 长江中游城市群生态福利绩效时空演变是在技术进步、环境规制、产业结构、人口集聚、发展共享、对外开放等多因子循环累积和共同推动下形成的,存在内源转化与外源驱动双重作用路径,并且与碳排放强度密切相关。在“双碳”目标下揭示生态福利绩效时空演变及驱动机制,有助于厘清自然生态与人类福利的转化机理以及生态福利绩效与碳排放的作用关系,可为城市群高质量发展和生态文明建设提供参考。     

利用LS_AR模型对极移参数的中长期预报

为了满足深空探测器自主导航定位对极移参数中长期预报的需求,阐述了基于LS_AR模型的极移参数中长期预报和精度评定的原理,提出了4种改进方案对LS_AR模型的构建进行优化,并利用IERS提供的1990～1996年的极移参数的时间序列检验4种优化方案,得到了最优的预报模型,在400 d跨度上,其预报结果的平均绝对误差比未优化的模型小3 mas左右。     

The challenge of dating early pleistocene fossil teeth by the combined uranium series–electron spin resonance method: the Venta Micena palaeontological site (Orce,Spain)

The palaeontological site of Venta Micena (Orce, Andalusia, Spain) lies in the eastern sector of the Guadix–Baza basin, one of the best documented areas in Europe for Plio‐Pleistocene biostratigraphy. The combination of biochronological and palaeomagnetic results, combined with the radiometric data obtained for Atapuerca Sima del Elefante, indicated that the Venta Micena stratum was formed between the Jaramillo and Olduvai palaeomagnetic events, most likely between 1.22 and 1.77 Ma. Five fossil teeth from two outcrops (sites A and B) were selected to assess the potential of combined uranium series–electron spin resonance (US‐ESR) dating of Early Pleistocene sites. Although the US‐ESR results of the first outcrop showed a large scatter between the three teeth, the mean age of 1.37 ± 0.24 Ma can be considered a reasonable age estimate for Venta Micena. The mean ESR age of 0.62 ± 0.03 Ma obtained for site B seems to be a severe underestimation when compared with the independent age control. This underestimation is attributed to a relative recent U‐mobilization event that led to some U‐leaching. The results show that any ESR age calculations of old samples are extremely sensitive to variations in the measured ²³⁰Th/²³⁴U ratios in dental tissues. Although the results demonstrate that ESR can in principle be applied to Early Pleistocene sites, they also reveal the complexity of dating such old teeth. It is necessary to continue research in several directions, such as study of the behaviour of ESR signals in old teeth and understanding recent U‐mobilization processes, to improve the reliability of the combined US‐ESR dating method applied to Early Pleistocene times, a period for which the number of available numerical dating techniques is very limited. Copyright © 2011 John Wiley & Sons, Ltd.     

Variation and pattern in the responses of mammal faunas to Late Pleistocene climatic change in southeastern South Australia

We examined mammal occurrence and variability through the Late Pleistocene vertebrate fossil deposit of Grant Hall in Victoria Fossil Cave, Naracoorte, South Australia. To determine long‐term patterns of change, we compared the composition and relative abundance trends of the assemblage with a nearby Middle Pleistocene deposit in Cathedral Cave. Total species richness did not change through the Grant Hall sequence, dated from 93 ± 8 to 70 ± 5 ka. However, species relative abundances varied between ecologically divergent species, and in some cases between species that demonstrate similar environmental preferences. For some species this variation is comparable to that recorded in Cathedral Cave. Of those showing similar trends between the two deposits, the forest inhabitant, Pseudomys fumeus, recorded an 8.6% decline through Grant Hall, coincident with a 9.7% increase in the dry heath/mallee dweller Pseudomys apodemoides. These patterns indicate that climatic transition from relatively warm, moist to cooler, drier conditions impacted some species in similar ways through climatic cycles of the past. However, the majority of the fauna demonstrated complex responses that are individual and variable through time. Statistical tests of species trends from the Grant Hall assemblage caution that large fossil samples are required to validate patterns observed. Copyright © 2012 John Wiley & Sons, Ltd.     

Improved age constraint for pre‐ and post‐Anglian temperate‐stage deposits in north Norfolk,UK, from analysis of serine decomposition in Bithynia opercula

The ‘new glacial stratigraphy’ (NGS) of Britain postulates that deposits hitherto assigned to the Anglian glaciation in Marine Isotope Stage (MIS) 12 represent MIS 16, 12, 10 and 6. This controversial idea can be tested at Sidestrand in north Norfolk, where fossiliferous temperate‐stage deposits underlie the oldest and overlie the youngest of the glacial deposits. Previous work has considered biostratigraphy and amino acid dating of these temperate‐stage deposits, but did not achieve tight age constraint using the amino acid evidence alone. The total hydrolysable amino acid fraction in intra‐crystalline protein from Bithynia tentaculata opercula has previously been analysed for concentrations of serine and alanine. Statistical screening of these data gives alanine/serine ratios of 4.572 ± 0.114 for the Sidestrand Hall Member (beneath the glacial deposits) and 3.564 ± 0.091 for the Sidestrand Cliff Formation (overlying the glacial deposits). These ratios imply ages of MIS 13a and 11c, respectively, indicating the latest Cromerian and early Hoxnian interglacials and invalidating the NGS. Copyright © 2009 John Wiley & Sons, Ltd.     

Paleomagnetic Excursions Recorded in the Yanchi Playa in Middle Hexi Corridor, NW China Since the Last Interglacial

Paleomagnetic determinations on lithologieal profiles of two paralleled long drillin gcores covering the past 130 kyr B.P., GT40 and GT60,from the Yanchi Playa in the arid Northwestern China indicate that a series of pronounced paleomagnetic excursions have been documented. By correlating our results with published regional and worldwide reports 4 excursion events out of 10 apparent reversal signals (labeled from GT-1 to GT-10) were identified as excursion events coeval with the Mono Lake Event (28.4 kyr-25.8 kyr), Laschamp Event (43.3 kyr-40.5kyr), Gaotai Event (82.8 kyr-72.4 kyr) and the Blake Event (127.4 kyr-113.3 kyr), respectively. GT-9 correlates with the above-mentioned Gaotai Event,GT-7 and GT-6 correspond to two stages of the Laschamp Event and GT-5 to the Mono Lake Event. It is noteworthy that the so-called Gaotai Event has not been reported as a pronounced paleomagnetic excursion in the Northwestern China. Every magnetic excursion event corresponds to paleointensity minima, anteceding those established abrupt paleoclimatic change events, such as the Younger Drays and the Heinrich Events (H1-H6). Here, we tentatively propose that these geomagnetic excursions/reversals can be viewed as precursors to climate abruptness. During the transitional stages when the earth‘s magnetic field shifted between a temporal normal and a negative period, the earth‘s magnetic paleointensity fell correspondingly to a pair of minima. Although more precise chronology and more convincing rock magnetic parameter determinations are essentially required for further interpretation of their intricate coupling mechanism, these results may have revealed, to some extent, that the earth‘s incessantly changing magnetic field exerts an strong influence on the onset of saw-tooth shaped abrupt climate oscillations through certain feedback chains in arid Central Asia or even North Hemispheric high latitude regions.     

AN ANALYSIS OF THE POLICY－MAKING IN REGULATING THE INDUSTRIAL STRUCTURE AND DISTRIBUTION IN TRADITIONAL INDUSTRIAL BASE IN MIDDLE LIAONING PROVINCE

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