高效非损伤性扇贝DN A提取方法的建立及效果评价

本研究建立了一种高效、经济的非损伤性扇贝DNA提取方法,在不影响扇贝个体生存状态的前提下,采用擦拭法和室温裂解相结合的方式在20 min内即可获得个体基因组DNA。以虾夷扇贝(Patinopecten yessoensis)、栉孔扇贝(Chlamys farreri)和海湾扇贝(Argopecten irradians)为实验对象,研究了不同擦拭材料(棉签、滤纸)和不同擦拭部位(外套膜、鳃丝、内脏团)的核酸提取效果,评估了本方法在贝类基因分型领域应用的可行性。研究表明,用棉签、滤纸2种材料擦拭扇贝的鳃丝、内脏团或外套膜组织均能获得主带清晰完整的基因组DNA,且不影响扇贝的存活状态。在3种扇贝中采用棉签擦拭法的DNA得率均高于滤纸法,以这2种方式获得的DNA为模板进行SSR和SNP标记分析,能获得均一稳定的扩增条带,SSR标记分型结果准确可靠。本研究建立了简便、快速进行扇贝基因型分析的非损伤性DNA提取方法,为贝类全基因组选育和珍稀贝类资源的种质保护开发提供了新的技术手段。     

饱和颗粒正冻土一维刚性冰模型的数值模拟

基于刚性冰模型,应用有限差分法离散方程组,对于饱和颗粒土开放系统的冻结过程进行了一维数值模拟,给出了冻结缘内参数的分布.计算过程中修正了刚性冰模型中分凝冰产生条件,提出以冻结缘内冰压与载荷的关系作为分凝冰产生的判据,计算得到的冻胀量与实验室冻胀实验的测量数据较为吻合.将计算结果与现场实测资料进行了比较,温度场、含水量分布等结果在分布规律方面与现场实测资料相符.     

AFLP analysis revealed differences in genetic diversity of four natural populations of Manila clam(Ruditapes philippinarum) in China

1 IntroductionManila clam (Ruditapes philippinarum) is aworldwide distributed species. In China, it is foundfrom the northern to southern seashores (Wang etal., 1993; Zhuang, 2001). This species is eura-line with the salinity tolerance ranging from 20 to4…     

Spatiotemporal variations of suspended sediment transport in the upstream and midstream of the Yarlung Tsangpo River (the upper Brahmaputra), China

The Yarlung Tsangpo River, which flows from west to east across the southern part of the Tibetan Plateau, is the longest river on the plateau and an important center for human habitation in Tibet. Suspended sediment in the river can be used as an important proxy for evaluating regional soil erosion and ecological and environmental conditions. However, sediment transport in the river is rarely reported due to data scarcity. Results from this study based on a daily dataset of 3 years from four main stream gauging stations confirmed the existence of great spatiotemporal variability in suspended sediment transport in the Yarlung Tsangpo River, under interactions of monsoon climate and topographical variability. Temporally, sediment transport or deposition mainly occurred during the summer months from July to September, accounting for 79% to 93% of annual gross sediment load. This coincided with the rainy season from June to August that accounted for 51% to 80% of annual gross precipitation and the flood period from July to September that accounted for approximately 60% of annual gross discharge. The highest specific sediment yield of 177.6 t/km²/yr occurred in the upper midstream with the highest erosion intensity. The lower midstream was dominated by deposition, trapping approximately 40% of total sediment input from its upstream area. Sediment load transported to the midstream terminus was 10.43 Mt/yr with a basin average specific sediment yield of 54 t/km²/yr. Comparison with other plateau‐originated rivers like the upper Yellow River, the upper Yangtze River, the upper Indus River, and the Mekong River indicated that sediment contribution from the studied area was very low. The results provided fundamental information for future studies on soil and water conservation and for the river basin management. Copyright © 2017 John Wiley & Sons, Ltd.     

利用地震矩张量反演鲜水河断裂带现今运动学特征

本文探讨了利用地震矩反演断裂形变带运动学参数的基本理论和方法，将其初步应用于鲜水河断裂形变带变形分析和运动机制的研究。结果表明，鲜水河断裂带呈现出走向拉伸、倾向压缩的形变格局，由地震矩反演的断裂带剪切形变速率（１０．９ｍｍ／ａ）与用地质学估算方法（１７ｍｍ／ａ）和现今地壳形变测量（８ｍｍ／ａ）的结果相当。同时，反演出的应变主方向能解释鲜水河断裂现今活动分段性特征以及多种滑动方式共存的现状，从而证明该方法是目前研究区域运动学问题切实有效的手段之一。     

用土的分形结构确定土的水份特征曲线

运用筛析法和比重计法，分析了宁夏膨胀土的颗粒分布，发现粒径介于0．002～0．1mm的粒度分布是分形的，分维介于2．46～2．67；运用上孔隙分布的分维确定水份特征曲线，得到了很好的结果。此外，还探讨了粒度分形分布的机制。     

Full‐scale shaking table test of a base‐isolated medical facility subjected to vertical motions

Base isolation is a well known technology that has been proven to reduce structural response to horizontal ground accelerations. However, vertical response still remains a topic of concern for base‐isolated buildings, perhaps more so than in fixed‐base buildings as isolation is often used when high performance is required. To investigate the effects of vertical response on building contents and nonstructural components, a series of full‐scale shaking table tests were conducted at the E‐Defense facility in Japan. A four‐story base‐isolated reinforced concrete building was outfitted as a medical facility with a wide variety of contents, and the behavior of the contents was observed. The rubber base isolation system was found to significantly amplify vertical accelerations in some cases. However, the damage caused by the vertical ground motions was not detrimental when peak vertical floor accelerations remained below 2 g with three exceptions: (1) small items placed on shelves slid or toppled; (2) objects jumped when placed on nonrigid furniture, which tended to increase the response; and (3) equipment with vertical eccentricities rocked and jumped. In these tests, all equipment and nonstructural components remained functional after shaking. Copyright © 2013 John Wiley & Sons, Ltd.     

鲜水河断裂带现今断层运动短周期事件的发现与初步研究

根据鲜水河断裂带上连续动态地壳形变台阵数据，首次揭示了中国大陆板内断层现今运动的短周期现象，包括蠕变阶、蠕变坡和脉动等，其持续时间为数分钟至数十小时。发现其空间分布与断层分段（闭锁或活动段）有关；其时间分布与强地震孕育过程有关。蠕变过程符合Ｌｏｍｎｉｚ提出的对数蠕变函数，可能是断层面不均匀结构中的局部流变行为。断层短周期事件对揭示断层不均匀结构和微破裂过程动力学有重要意义，并可能发展为一种新的地震前兆     

大气臭氧与气溶胶垂直分布的高空气球探测

本文给出了1993年9月12日利用高空科学气球在河北省香河地区探测到的大气臭氧和气溶胶的垂直分布。结果发现:(1) 大气臭氧的数密度在整个对流层较低(～10[12]mol/cm3)，并从地面到对流层顶略有下降；对流层顶以上开始快速增加，极值层高度在～24 km，其值为4.78×10[12]mol/cm3；臭氧分压有类似的分布特征，极值146×10[-4]Pa，位于同一高度；(2) 在平流层低层，臭氧分压有一个次极值62×10[-4]Pa，位于15～16 km；(3) 0～30 km大气气溶胶数密度呈现出三个峰值:143，8和1.1 个/cm[3]，分别位于近地面、5 km和21 km；（4）气溶胶的数密度谱在对流层为双模态；在平流层，次峰消失。同时，我们还与其他观测结果作了比较分析。     

线翼截断方式对大气辐射计算的影响

在大气辐射传输计算方法中,有3种基本方法,即,逐线积分方法,k-分布方法和带模式方法。其中,逐线积分方法是最精确的计算大气透过率的方法,本文根据透过率计算方式的不同,将逐线积分方法分为追线积分法和追点积分法。由于逐线积分计算需要耗费大量的计算时间,在大气遥感和大气探测业务中使用时,必须减少计算成本,提高计算速度。本文在追线积分法的基础上,给出了简化的逐线积分的基本方法,在保证同样计算精度的同时,大大提高了计算速度。对在精确的和简化的逐线积分下,不同线翼截断方式(CUTOFF)对吸收系数、大气透过率和冷却率的影响进行了更详细的探讨。通过数值试验发现,对谱线线翼的截断方式是影响辐射计算精度和计算速度的重要因子。在不同压力下,用CUTOFF=2计算的吸收系数误差最大;对CUTOFF=1,在大多数取样点上误差都小于2%;对CUTOFF=3或4,对绝大多数取样点上计算的吸收系数误差都在5%以内,但所用的计算时间却明显减少。大气低层的透过率对不同的计算方法和不同的线翼截断方式不敏感;对大气高层,无论是对精确的还是简化的逐线积分方法,当CUTOFF=2时的透过率结果与其他线翼截断方式的结果差别较大。通过比较,本文给出线翼截断的优选方案。