黄河第一湾齐哈玛河段砾质网状河1990年以来的演变特征（英文）

The anastomosing river that is present within the First Great Bend of the Yellow River is different from other sand-bedded rivers of this type because it contains gravel-bedded materials. It is therefore important to determine whether, or not, the specific characteristics of this anastomosing river are similar to those seen in sand-bedded forms, including the characteristics of erosion and deposition, and the stability of channel and interchannel wetlands. Four Landsat images from 1990, 2001, 2013, and 2016 alongside two Google Earth(GE) images from 2011 and 2013 were utilized in this study in tandem with field sampling and observations to select a 12 km main channel length section of the Qihama reach anastomosing river. This section was then used to determine variations in channel planform and sedimentary characteristics over a 26 year period. The results of this study show that this gravel-bedded anastomosing river has exhibited a high degree of stability overall, and that there has been no obvious channel and wetland bank erosion and deposition. Data also show that over the 26 years of this study, anastomosing belt area increased by 2.43%, while the ratio of land to water area remained almost equal. The number of wetlands has also increased along this river section at a rate as high as 62.16% because of the fragmentation of some small interchannel examples, while the talweg has alternately migrated to either the left or right over long periods of time at a relatively stable rate. Indeed, as a result of the migration of this line, there has been significant turnover in the number of islands within the main channel while bank shift has occurred at a rate of about 5 m/yr. The numerous anastomosing channels within this river section remained very stable over the course of this study, characterized by a mean annual migration rate of just 1 m/yr, while the sediments in bank columnar sections are mainly composed of fine sands or silts with a relatively high clay content. The sediment grain-size distribution curve for this river section contains multiple peaks, distinct from the muddy sediments within bank columnar sections from sand-bedded anastomosing rivers. The dense vegetation within riparian and interchannel wetlands alongside this river reach has also protected anastomosing channels from erosion and maintainedtheir stability, a key feature of this gravel-bedded system.     

4月龄大菱鲆苗种耐氨氮性状的遗传参数评估

本实验采用40个家系共计954尾大菱鲆(Scophthalmus maximus)为实验材料,应用一般动物模型评估4月龄大菱鲆的耐氨氮性状、体长、体重的遗传力和遗传相关。研究表明,4月龄大菱鲆耐氨氮性状遗传力为0.46±0.20,属于高遗传力,其估计值与0相比达到显著水平(P0.05),具备开展基于表型性状的耐氨氮选育潜力。体长遗传力为0.14±0.22,属于低遗传力;体重遗传力为0.29±0.30,属于中等遗传力;体长和体重遗传力估计值与0相比均未达到显著水平。4月龄大菱鲆耐氨氮性状、体长、体重的相关性分析表明,大菱鲆的耐氨氮性状与体长的遗传相关和表型相关分别为-0.06±0.59和-0.10±0.06;耐氨氮性状与体重的遗传相关和表型相关分别为-0.02±0.48和-0.06±0.06;耐氨氮性状与体长和体重两个性状的相关性非常低,且统计检验均不显著。研究结果表明,以耐氨氮性状为选育指标,不会对大菱鲆的体长和体重产生显著影响。该研究为大菱鲆耐氨氮品种选育提供一定的理论参考。     

“三权分置”——农村宅基地制度的重大创新(上)

正2018年中央一号文件提出,完善农民闲置宅基地和闲置农房政策,探索宅基地所有权、资格权、使用权"三权分置",落实宅基地集体所有权,保障宅基地农户资格权和农民房屋财产权,适度放活宅基地和农民房屋使用权。深刻理解"三权分置"的重大意义,正确诠释"三权分置"的法理基础,加快探索"三权分置"的实现形式,是深化农村宅基地制度改革     

乡村振兴呼唤文化复兴

正十九大报告提出实施乡村振兴战略,并明确了"产业兴旺、生态宜居、乡风文明、治理有效、生活富裕"的20字总要求。这表明,乡村振兴是经济、生态、文化、科技、社会的全面振兴。"文化兴国运兴,文化强民族强"。乡村文化是中华文化的源头和主干,乡村文化的复兴在乡村振兴中具有基础和战略意义,是乡村振兴的关键之举。     

Spar平台吸力式基础极限承载特性数值分析

以国外某深海Spar平台工程为背景,针对其所采用的细长型吸力式基础的抗拔承载特性进行三维有限元数值分析.分析中充分考虑土体强度、加载位置和加载角度对吸力式基础极限抗拔承载力的影响,本构模型中钢筒基础采用弹塑性模型.分析结果表明,吸力式基础的极限抗拨承载力随着土体强度的增大而增大,倾斜加载时在基础插入土体部分中点左右加载可取得最大的极限承载力,极限抗拔承载力还随着加载角度的增大而增大.吸力式基础存在倾斜加载时桶基础与桶内外土体的共同塑性屈服破坏和垂直加载时桶外土体的局部剪切破坏等两种不同的破坏模式.