陆相断陷湖盆中层序边界的形成机理及其识别特征研究

陆相断陷湖盆中层序边界是由于沉积物表面高出沉积基准面或盆地基准面、沉积物发生剥蚀或无沉积作用所形成的，其产生机理主要有边界断层停止活动、断块翘倾活动、湖盆整体抬升和湖平面下降。层序边界在地震特征上、测井曲线上、钻井剖面中的岩性、岩相特征、古生物组合、微量元素的变化上均有明显的特征。利用这些特征，在济阳坳陷下第三系中识别出9个三级层序。     

Dietary Linseed Oil Reduces Growth While Differentially Impacting LC-PUFA Synthesis and Accretion into Tissues in Eurasian Perch (Perca fluviatilis)

The aim of this study was to evaluate the impact of replacing dietary fish oil (FO) with linseed oil (LO) on growth, fatty acid composition and regulation of lipid metabolism in Eurasian perch (Perca fluviatilis) juveniles. Fish (17.5 g initial body weight) were fed isoproteic and isoenergetic diets containing 116 g/kg of lipid for 10 weeks. Fish fed the LO diet displayed lower growth rates and lower levels of DHA in the liver and muscle than fish fed the FO diet, while mortality was not affected by dietary treatment. However, DHA content recorded in the liver and muscle of fish fed the LO diet remained relatively high, despite a weight gain of 134 % and a reduced dietary level of long‐chain polyunsaturated fatty acids (LC‐PUFA), suggesting endogenous LC‐PUFA biosynthesis. This was supported by the higher amounts of pathway intermediates, including 18:4n‐3, 20:3n‐3, 20:4n‐3, 18:3n‐6 and 20:3n‐6, recorded in the liver of fish fed the LO diet in comparison with those fed the FO diet. However, fads2 and elovl5 gene expression and FADS2 enzyme activity were comparable between the two groups. Similarly, the expression of genes involved in eicosanoid synthesis was not modulated by dietary LO. Thus, the present study demonstrated that in fish fed LO for 10 weeks, growth was reduced but DHA levels in tissues were largely maintained compared to fish fed FO, suggesting a physiologically relevant rate of endogenous LC‐PUFA biosynthesis capacity.     

试论中国大陆经向和纬向石油富集“黄金带”特征

从目前勘探现状、盆地成因、产层的主要时代等因素分析,中国大陆含油盆地可划为从依兰-伊通-渤海湾-江汉盆地群构成的经向带,和从准噶尔-二连-松辽盆地群组成的纬向带,二者共拥有中国石油总产量的94%和总储量的99%.因而我们分别称为经向和纬向石油富集“黄金带”.本文从中国板块构造演化、成盆构造背景和成藏条件等因素,分析了经、纬向石油富集带的共性和个性,并与国内二类三种含油气大地构造单元对比,认为纬向油气富集带具有最有利的石油勘探前景,建议列为“九五”期间中国大陆石油勘探的重点地区,其中应特别加强准噶尔盆地,沙漠区的勘探力度,可望找到特大型油田。     

中国与欧亚经济联盟主要国家重要贸易农食产品重金属限量标准对比分析

本文介绍了欧亚经济联盟主要国家从中国进口的重要贸易农食产品类别、中国与欧亚经济联盟农食产品的重金属限量标准与法规情况,并且从食品分类方式、农食产品限量指标等方面将中国和EAEU重要贸易农食产品重金属限量进行对比分析,以期为监管部门和企业进行相关研究和促进中国-欧亚经济联盟的农食产品贸易提供参考。通过比较,中国和欧亚经济联盟在食品的分类方式上有各自的特点和不同,我国食品分类较为全面但食品种类相对比较笼统细分度仍然不够,EAEU食品大类虽然不多但具体食品种类规定得比较详细和具体;我国和EAEU在重金属限量标准方面有较大差异,我国对于重要贸易农食产品制定了更为严格的铅限量指标,可以比较铅限量的22种农食产品中有11种农食产品我国规定了更低的铅限量标准;EAEU制定了更为严格的镉限量指标,可以比较镉限量的17种农食产品中有10种产品EAEU规定了更低的镉限量;此外,EAEU规定了部分重要贸易农食产品的镉、砷和汞的限量,而我国GB 2762中未有相关规定;造成这些差异的原因主要与中国和EAEU各国环境中重金属含量差异较大,而且也与各自的饮食习惯、社会文化因素、人群暴露风险和农食产品管理方式不同有关。要推动中国与欧亚经济联盟主要国家重要贸易农食产品出口贸易,需要政府、企业等多方合作共同促进。     

利用实测资料评估被动微波遥感雪深算法

利用SSM/I微波亮温数据,结合地面站点实测资料,比较Chang算法和Che算法在前苏联、中国及蒙古境内6种不同积雪类型的反演精度,结果表明:被广泛应用于全球雪深反演的Chang算法低估了前苏联境内雪深7.6cm,相对误差为-24.3%,而分别高估中国及蒙古境内雪深9.2cm与11.4cm,相对误差分别为108.8%和180.9%,区域反演效果很差;针对中国境内积雪的Che算法严重低估前苏联境内雪深,整体低估21.3cm,相对误差为-68.6%,RMSE为31.4cm;在中国及蒙古境内反演效果有所改善。6个积雪类型中,植被较单一,地形较平坦的苔原型积雪和草原型积雪雪深的反演效果较好。随着纬度和积雪深度的增加被动微波雪深反演有由高估变为低估的趋势。Che算法反演的雪深大体以40°N为界,以北表现为低估,以南表现为高估,另一方面,整体上该算法在雪深低于6.7cm时表现为低高估,高于6.7cm表现为低估;因此,全球算法应用到局部地区需要进行修正,不同下垫面性质以和气候条件下形成的积雪的被动微波反演应区别对待。     

新亚欧大陆桥河西走廊段资源型城市转型研究

河西走廊作为新亚欧大陆桥的重要通道,是我国西北地区经济建设和区域开发的重点。通过对河西走廊资源型城市发展所面临的障碍进行分析,以生命周期理论为指导,提出了重组空间结构,促使城市与区域协调发展;加大节水力度,调整用水结构;围绕资源,改变单一产业;依据生命周期,适时转型等具体的思路与建议,并得出了资源型城市转型的一些结论与启示。     

论余光中诗歌的祖国情结

对余光中的主要诗歌作品从思想内容上作了清晰的梳理,认为贯穿于其全部作品中的情感红线是深沉、强烈的祖国情结,包括大陆情结、历史情结、古典情结。充分表达了身居台湾的一代中国人的爱国、思乡、怀旧的深厚情感以及华夏儿女无论何时何地那种对祖国历史与文化的认同与归属。     

The great triangular seismic region in eastern Asia: Thoughts on its dynamic context

A huge triangle-shaped tectonic region in eastern Asia plays host to numerous major earthquakes.The three boundaries of this region,which contains plateaus,mountains,and intermountain basins,are roughly the Himalayan arc,the Tianshan-Baikal.and longitude line ～ 105°E.Within this triangular region,tectonism is intense and major deformation occurs both between crustal blocks and within most of them.Outside of this region,rigid blocks move as a whole with relatively few major earthquakes and relatively weak Cenozoic deformation.On a large tectonic scale,the presence of this broad region of intraplate deformation results from dynamic interactions between the Indian,Philippine Sea-West Pacific,and Eurasian plates,as well as the influence of deep-level mantle flow.The Indian subcontinent,which continues to move northwards at ～40 mm/a since its collision with Eurasia,has plunged beneath Tibet,resulting in various movements and deformations along the Himalayan arc that diffuse over a long distance into the hinterland of Asia.The northward crustal escape of Asia from the Himalayan collisionalzone turns eastwards and southeastwards along 95°-100°E longitude and defines the eastern Himalayan syntaxis.At the western Himalayan syntaxis,the Pamirs continue to move into central Asia.leading to crustal deformation and earthquakes that are largely accommodated by old EW or NW trending faults in the bordering areas between China,Mongolia,and Russia,and are restricted by the stable landmass northwest of the Tianshan-Altai-Baikal region.The subduction of the Philippine and Pacific plates under the Eurasian continent has generated a very long and narrow seismic zone along trenches and island arcs in the marginal seas while imposing only slight horizontal compression on the Asian continent that does not impede the eastward motion of eastern Asia.In the third dimension,there may be southeastward deep mantle flow beneath most of Eurasia that reaches the marginal seas and may contribute to extension along the eastern margin of Eurasia.     

库区洲滩潜流带温度示踪流速计算方法

以澜沧江漫湾库区洲滩为研究对象,实时监测水库运行期间洲滩监测井水位和水温变化过程,依据水位和水温数据,分别用水动力学法和温度示踪法核算流速。结果表明:在计算库区水位波动引起的潜流交换上,Hatch相位法具有更高的准确性,监测时段内的潜流交换流速和交换量分别为-5.87×10~(-5)~12.92×10~(-5)m/s和2.66m~3。在计算库区与洲滩补给和排泄过程中的峰值流速时,Hatch相位法的计算结果均较水动力学法滞后。在空间上,洲滩深度越深,流速越小,不同深度流速曲线规律基本一致。     

“一带一路”战略构想中的空间框架探讨

“一带一路”战略的推进,需要深 刻领会空间基础,构建合理的空间框架, 支持区域合作。本文通过对“一带一路”战 略区域地理环境、人文历史、社会经济的 分析,以国际贸易导致所有人受益为逻辑基 础,探索支持交融发展空间框架,认为区域 空间基础是多样的地理单元和多元的社会 文化单元的有规律组合,不同单元之间存 在边界制约,区域合作通过建立广泛的地 理连接、畅通关键节点、加强各类基础设 施合作的方法,突破边界,连接单元,构建 区域空间网络的构架,主体是4条东西向线 和海上线,并与若干南北向的发展联结,形 成一个网络型空间。中国作为发起参与“一 带一路”战略的地理单元,要注重外向型 建设,稳固沿海港口建设,强化边疆地区建 设,形成三纵三横空间网络,参与“一带一 路”战略,促进区域可持续发展。