绿色农业视角下青海特色农业发展路径及对策

绿色农业是二十一世纪农业发展的理想模式。青海独特的地域环境和资源条件形成了丰富的特色农业资源,也为发展绿色农业奠定了基础。文章通过对青海特色农业绿色化发展条件的分析,指出了特色农业的发展目标,并提出了实施路径及相关对策。     

塔西佗历史书写中的“年代记”及其政治功能北大核心CSSCI

塔西佗以传统“年代记”体裁写作自奥古斯都到图密善统治时期的历史。他的历史探讨最深刻的人性与政治的关系,以此论证元首政体的好坏与统治者品性之间的联系。塔西佗的政治生涯大部分在图密善时代度过,在图拉真统治时期开始写作历史。图密善的暴政使他对历史写作持谨慎小心的态度,而暴政带来的影响使他希望通过历史写作给贵族阶层提供政治教诲,培育政治上的审慎美德,以便服务于国家。历史写作上的谨慎和提供教诲的愿望,使他放弃了当时流行的皇帝传记体裁而选择传统“年代记”体裁。尽管“年代记”与皇帝传记一样,都把皇帝作为叙述中心,但塔西佗研究的重点是皇帝的统治技巧、计谋和贵族阶层对此的回应,这种叙述体裁的选择因而也是其写作意图的组成部分。     

Thermochemical and bacterial sulfate reduction in the Cambrian and Lower Ordovician carbonates in the Tazhong Area,Tarim Basin,NW China: evidence from fluid inclusions,C, S,and Sr isotopic data

Petrographic features, C, O, S, and Sr isotopes were determined, and fluid inclusions (FI) were analyzed on various stages of vug‐ and fracture‐fillings from the Cambrian and Lower Ordovician reservoirs in the Tazhong area, Tarim basin, NW China. The aim was to assess the origin of pyrite and anhydrite and the processes affecting sulfur during diagenesis of the carbonates. Pyrite from seven wells has δ³⁴S values from ?22‰ to +31‰. The pyrites with low δ³⁴S values from ?21.8‰ to ?12.3‰ were found close to fracture‐filling calcites with vapor‐liquid double‐phase aqueous fluid inclusions homogenization temperatures (FI‐Th) from 55.7 to 73.2°C, salinities from 1.4wt% to 6.59wt% NaCl equiv and δ¹³C values from ?2.3‰ to ?14.2‰, indicating an origin from bacterial sulfate reduction by organic matter. Other sulfides with heavier δ³⁴S values may have formed by thermochemical sulfate reduction (TSR) during two episodes. The earlier TSR in the Middle and Lower Cambrian resulted in pyrites and H₂S having δ³⁴S values from 30 to 33‰, close to those of bedded anhydrite and oilfield water (approximately 34‰). The later TSR is represented by calcites with δ¹³C values as light as ?17.7‰ and FI‐Th of about 120–145°C, and pyrite and H₂S with δ³⁴S values close to those of the Upper Cambrian burial‐diagenetic anhydrite (between +14.8‰ and +22.6‰). The values of the anhydrite are significantly lighter than contemporary seawater sulfates. This together with ⁸⁷Sr/⁸⁶Sr values of anhydrite and TSR calcites from 0.7091 to 0.7125 suggests a source from the underlying Ediacaran seawater sulfate and detrital Sr contribution.     

A new species of Loricera Latreille from Eocene Baltic amber (Coleoptera: Carabidae: Loricerinae)

Cai, C., Liu Y. & Huang, D., February 2017. A new species of Loricera Latreille from Eocene Baltic amber (Coleoptera: Carabidae: Loricerinae). Alcheringa xx, xxx-xxx. ISSN 0311-5518.

Loricerinae is a small, distinctive subfamily of ground beetles, comprising only one genus Loricera Latreille. Only one fossil species is known to date. Here, we describe a new species, Loricera groehni sp. nov., belonging to Loricera based on a well-preserved adult in Eocene Baltic amber. Loricera groehni is tentatively attributed to the obsoleta group of the subgenus Loricera s.str. based on the relatively long antennomere 3 and punctate elytral interval 7. The discovery of a new species morphologically close to the extant Loricera species from western China and northern India suggests that the obsoleta group was more widespread in the Eocene than it is at present. The distribution pattern of Chinese Loricera is probably relictual. The fossil species, possessing conspicuous stiff setae on the basal antennomeres, was probably a specialized predator of springtails.

Chenyang Cai [cycai@nigpas.ac.cn], Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China; Ye Liu [liuye198282@126.com], Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, PR China; Diying Huang [dyhuang@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China.     

Spatial and temporal variety of prehistoric human settlement and its influencing factors in the upper Yellow River valley,Qinghai Province,China

We report an investigation of forty-two prehistoric sites in the upper Yellow River valley located in Guide, Jianzha, Hualong, Xunha and Minhe, Qinghai Province, China, including forty-four new radiocarbon dates from twenty-four sites, review published archaeological surveys and radiocarbon dates, analyze landform features and discuss the reasons for spatial and temporal variety of regional prehistoric human settlement. Our results suggest that people occupied the upper Yellow River valley during the early Holocene, but a continuous archaeological record begins only after about 5500 Cal yr BP. Thereafter, the intensity of prehistoric human settlement in the area is varied. Neolithic human settlement spread northwestward to high altitude areas of the upper Yellow River valley during early-mid Majiayao and Qijia periods, but moved southeastward to lower locations in the area during late Majiayao period. During the Bronze period, two coeval archaeological cultures, the Kayue and Xindian, occupied the upper Yellow River Region. Kayue archaeological sites are numerous and widely distributed in the high areas of the upper Yellow River, while Xindian sites are restricted to the lowest basin of the region. Variation in site density and location are likely the result of changing paleoclimate and technology.     

Transition Urbanism and the Contested Politics of Ethical Place Making

Abstract: This paper explores the contested construction of more relational urban imaginaries within a movement that is simultaneously committed to enhanced systems of care for distant places/others, and intensified regimes of (re)localisation. Transition Culture initiatives explore ‘how to prepare for a carbon constrained, energy lean world’ and stem from a concern for a post peak‐oil global future. While the radical political openness of Transition Culture is in keeping with the vision of a more diverse polity imagined by advocates of relational space (for instance Amin, 2004), we argue that this openness is predicated upon an apolitical pragmatism that masks latent tensions between an environmentally benign localism and an ethics of care at‐a‐distance. If a transitional ethics of space occupies the uncertain ground between a relational and territorial geographical imagination, the Transition Culture movement provides a rich context within which to explore the ethical conundrums that stem from different tactics of place‐making.