《后魏孝文帝与高句丽王云诏》中所见魏、丽形势及双方关系

北魏孝文帝给高句丽王高云的诏书是一份非常重要的文献,诏书于太和十六年九、十月份发出,要求高句丽派遣王弟入朝,高句丽最终顺从了北魏的要求。诏书内容可以弥补多件文献阙载的历史事件,可以藉此了解孝文帝精心策划迁都洛阳过程中对内树立权威、对外极力笼络的手段,对研究高句丽国情、魏丽关系大有裨益。     

内蒙古人口与粮食问题研究

内蒙古地处中纬度内陆地区,生态环境脆弱,干旱和半干旱面积占自治区总面积的80%以上。长期以来,形成的观念是内蒙古地广人稀、资源丰富,尤其是"文革"期间,在牧民不吃亏心粮口号的驱使下,将大向积林草地辟为粮田,导致草场的退化和土地的沙化。本文分析内蒙古人口发展和粮食生产的历史和现状,揭示在PRED系统中,人口增长与粮食生产面临的主要问题,结合内蒙古"九五"计划和2010年远景目标的要求,提出控制人口数量,提高粮食单产水平,实行退耕还草还林、降低耕地总量,保持人均粮食产量的动态平衡。     

Experimental study of aqueous fluid infiltration into quartzite: implications for the kinetics of fluid redistribution and grain growth driven by interfacial energy reduction

To investigate the kinetics of interfacial energy‐driven fluid infiltration, experiments were carried out in a quartzite–water system at 621–925°C and 0.8 GPa. Infiltration couples were made by juxtaposing presynthesized dry quartzite cylinders and fluid reservoirs. The infiltration process was confirmed by the presence of pores at the quartzite grain edges. As predicted from theoretical considerations and previous experiments, wetting fluids such as pure water and NaCl aqueous solution infiltrated into quartzite, whereas nonwetting CO₂‐rich fluids did not. Newly precipitated quartz layers at the surfaces of the infiltrated sample proved that infiltration took place by a dissolution–precipitation mechanism. The enhancement of grain growth by fluid infiltration was observed over the entire range of experimental temperatures. The fluid fraction, gauged by the porosity of the run products, increases at the infiltration front and then decreases towards the fluid reservoir to form a high‐porosity zone with a maximum porosity of 2.3–2.9%. As infiltration proceeds, the high‐porosity zone advances like a travelling wave. This porosity wave is probably caused by a grain curvature gradient resulting from preferential grain growth in the infiltrated part of the quartzite, perhaps combined with other factors. The infiltration kinetics were modelled with a steady‐state diffusion model over the high‐porosity zone. The solubility difference between dissolving and precipitating grains was deduced to be 2 × 10^?2?3 × 10^?1 wt %. The experimentally obtained infiltration rate of aqueous fluid in the steady‐state diffusion regime (2 ± 0.5 × 10^?8 m sec^?1 at 823°C) is much faster than the estimated metamorphic fluid flux rates, so that interfacial energy‐driven fluid redistribution in quartz‐rich layers could significantly contribute to the fluid flux in high‐grade metamorphism, at least over a short distance. Cathodoluminescence observations of the run products revealed that the grain growth of quartzite in the presence of fluid proceeds extensively, which would promote the chemical equilibration between fluid and rock more effectively than would volume diffusion in quartz crystals.     

民国时期江汉平原的粮食市场

粮食贸易在民国时期江汉平原的农村经济中占有重要地位,粮商及粮商组织、粮食加工和运输、粮食价格、粮食集散和粮食存储等几个方面反映了民国时期江汉平原的粮食市场的基本情况。粮食贸易将大量的基层市场、少量中间市场和几个中心市场联系在一起,粮食价格的趋同性表明这个地区当时存在着完整的粮食贸易体系,但相关市场特征又表明这个市场是不完善的。     

The escape from famine in the Northern Netherlands: a reconsideration using the 1690s harvest failures and a broader Northwest European perspective

A long historiography has concluded that the Northern Netherlands was famine free by the seventeenth century. However, this view has been established on limited grain price data and an unclear chronology, lacking a broader comparative perspective, and relying heavily on the explanation that Amsterdam was the centre point of the international grain trade. Using newly compiled burials data for the Northern and Southern Netherlands and Northern France, and integrating these with rye prices, we confirm empirically that price spikes had reduced mortality effects in the Northern Netherlands compared to the Southern Netherlands and Northern France, though the escape was greater in the cities than the countryside. The only time in the period 1551–1699 that a strong and generalized association between price spikes and mortality occurred across wide areas of the Northern Netherlands was in the famine of 1556/7. However, the international grain trade cannot explain everything. Markets in the Northern Netherlands were no more effective at smoothing out food crises than in the Southern Netherlands or Northern France. We offer alternative explanations: the reduced role of famine-related diseases spread by warfare, and the interaction (especially in the cities) between wages and poor relief.     

Apatite grain boundary morphology and its response to low-temperature fluid infiltration in crystalline basement

Apatite grain boundaries on fractured rock surfaces have been examined in an amphibolite facies regional metamorphic granite gneiss from the central Swiss Alps. The morphology of apatite has been characterized using a scanning electron microscope and matched to surface textures in adjoining silicates. Apatites show a wide variety of different surface features ranging from planar crystal faces, to small-scale ridges and dimples, to extensive irregular pitting. Many of these features form in response to the periodic infiltration of fluids along open grain boundaries during the cooling history of the gneiss. Apatite shows evidence of both dissolution and re-precipitation that is controlled by the nature of the grain boundary, the structure of the adjoining silicate phase and the alteration of the host rock. Fracturing occurs in a range of retrograde conditions and is common both within the apatite and along grain boundaries. This coupled to the evidence of fluid interaction with mineral surfaces suggests that extensive permeable networks may be typical of cooling crystalline basement rocks. Grain boundary textures have the potential to reveal a unique record of fluid infiltration in the crust that would be very difficult to decipher using traditional petrographic methods.     

试论汉代的仓囷明器与储粮技术

作者从汉墓中出土的陶质仓困建筑明器,以及汉画像中所见的粮仓建筑资料中撷取若干,初步探讨了汉代地上粮仓建筑的形制以及当时的储粮技术等问题。     

明清时期潮州粮食供给地区及路线考

明清时期, 潮州地区由于商品经济的发展, 粮食日益不能自给, 不得不到本地区之外购买粮食。随着粮食需求的不断增大, 江西赣州, 广东雷州、琼州、高州, 福建厦门、台湾, 东南亚暹罗、越南等国先后成为潮州粮食的供给地。粮食供给地的变化, 引起贸易路线的变迁。潮州粮食贸易亦与潮州华侨出国有很大关系, 潮州的粮食贸易形成自己独特的原因和规律。     

基于人牙结石的淀粉粒证据探讨裴李岗遗址先民植物性食物来源

人牙结石淀粉粒分析是开展古代居民食物来源研究的有效途径之一。用此方法对河南新郑裴李岗遗址仅存的两具裴李岗文化人骨牙齿上的结石开展了淀粉粒分析,成功提取出38颗淀粉粒,其中可鉴定种属的淀粉粒主要来自于栎属、豆科和块茎类等非农作物,少量有可能来自于粟黍类作物。虽然分析样品较少,提取出的淀粉粒数量不多,但这一结果或许表明采集植物有可能构成了裴李岗遗址居民植物性食物的主体。结合贾湖、莪沟、石固和寨根等裴李岗文化遗址的植物考古学研究,裴李岗文化居民的食物结构具有广谱性特征。本研究为全面认识中原地区裴李岗文化居民食物构成和聚落生业经济,深入探讨中原地区早期农业形成过程等提供了新思路和新证据。