龙井茶生长环境的地球化学研究

地球化学环境同地理景观、气候条件等是决定名优特产分布及其品质的主要因素。本文应用了勘查地球化学方法和技术,研究着称于世的西湖龙井茶的分布及其质量与下伏岩石以及土壤地球化学特征间的关系。结果表明,土壤类型、性质及其元素全量和有效量直接影响到龙井茶的质量,而土壤地球化学特征又与成土母岩具一定的关系,因此,基于岩石土壤的地球化学调查可以科学地进行土地利用规划,指导茶园合理施肥,科学管理。     

A new record of Sebastes koreanus from China based on morphological characters and DNA barcoding

A new record of Sebastes koreanus(Kim and Lee,1994) was documented based on morphological characters and DNA barcoding. Fifty-six S ebastes specimens were collected from the coastal waters of northern China. Samples were identified as S. koreanus based on morphological characters. The coloration and morphometric measurements were consistent with those described from specimens collected in South Korea. In this study,specimens had the following morphological characteristics:light brown body with dark stripes and tiny dark spots,4–5 wide indistinct vertical patterns on the side,2 radial stripes behind and below the eyes,1 large dark blotch on the opercle. Additionally,the following meristic characters were recorded:dorsal fin XIV-13,pectoral fin 16,anal fin III-6–7,pelvic fin I-5,lateral line scales 29–30,and vertebrae 26. The fragment of cytochrome oxidase subunit I(C OI) gene of mitochondrial DNA was sequenced for phylogenetic analysis. The mean genetic distance within the species was 0.3%. Net genetic distances between S. koreanus and other S ebastes species ranged from 3.1% to 7.6%,which was greater than the threshold for species delimitation. The phylogenetic analysis strongly supports the validity of S. koreanus in China at the genetic level. The origion,evolution,patterns of speciation and unique features in genome divergence among primate lineages of this species still need future directions of research.     

A Robust Algorithm for Constructing Pit-Free Canopy Height Model

Due to the penetration ability of airborne light detection and ranging (lidar) into tree crowns, data pits commonly appear in lidar-derived canopy height models (CHMs). They have a seriously negative effect on the quality of tree detection and subsequent biophysical measurements. To construct a pit-free CHM, an algorithm based on robust locally weighted regression and robust z-score was presented to remove data pits. The significant advantage of the new algorithm is parameter-free, which makes it efficient and robust for practical applications. A numerical test and a real-world example were respectively employed to assess the performance of our method for CHM construction, and its results were compared with those of three classical methods including natural neighbor interpolation of the highest point method, mean and median filters. The numerical test demonstrates that our algorithm is more accurate than the other methods for generating pit-free CHMs under the presence of data pits. The real-world example shows that compared with the classical methods, our method has a better ability of data pit removal. Moreover, our method performs better than the other methods for deriving plot-level maximum tree height from CHMs. In a word, the new method shows high potential for pit-free CHM construction.     

高精度曲面模型解算改进的Gauss-Seidel法

为了降低HASM的时间复杂度,采用一种改进Gauss-Seidel(GS)算法(MGS)解算HASM方程组。首先,从理论上分析了MGS算法收敛速度快于GS算法,然后以高斯合成曲面作为研究对象,用四组模拟试验表明,相同的网格数、达到相同的计算精度,MGS算法计算时间小于GS算法,且两种算法时间差与模拟区域网格数呈二次线性相关;固定网格数,使用相同的内迭代或者外迭代次数,MGS算法精度高于GS算法,但增加内迭代或者外迭代次数,GS算法同样收敛;MGS算法计算时间与网格数呈线性相关。MGS算法能够有效解决HASM模拟大区域的计算时间瓶颈,提高HASM运算速度。以甘肃省董志塬某测区SRTM3作为研究对象,基于MGS的HASM用于模拟DEM表明,HASM精度要高于传统的插值方法。     

HASM-AD algorithm based on the sequential least squares

The HASM(high accuracy surface modeling) technique is based on the fundamental theory of surfaces,which has been proved to improve the interpolation accuracy in surface fitting.However,the integral iterative solution in previous studies resulted in high temporal complexity in computation and huge memory usage so that it became difficult to put the technique into application,especially for large-scale datasets.In the study,an innovative model(HASM-AD) is developed according to the sequential least squares on...     

日本绒螯蟹线粒体DNA序列研究I.12S rRNA

参考果蝇与蚤状     

大头鳕和半滑舌鳎RAPD分析条件的优化

大头鳕和半滑舌鳎是我国重要的两种经济鱼类,本论文以大头鳕和半滑舌鳎基因组DNA为模板,对RAPD分析中的DNA模板浓度进行了优化,确定最适浓度。并分别筛选出20条和18条扩增结果稳定性好、多态性强的随机引物用于大头鳕以及半滑舌鳎的RAPD遗传变异分析。     

华鳈人工繁殖和早期发育的研究

1992年5月～7月分别对9组华鳈亲鱼进行的催产试验结果进行分析,并对其早期发育进行了较为详细的观察。华鳈受精卵在水温为22～33℃的条件下胚胎发育时间为54～74h,水温34℃左右时仍能正常发育;孵出时眼黑色,胸鳍基已形成,有发达的居氏管;孵出后第二天鳔即充气,第三天可以摄食并能自由在水层生活。     

Spatio-temporal distribution of vascular plant species abundance on Qinghai-Tibet Plateau

Journal of Geographical Sciences - For quantitatively explaining the correlations between the vascular plant species abundance (VPSA) and habitat factors, a spatial simulation method has been...     

Scenarios of land cover in Eurasia under climate change

The method for surface modelling of land cover scenarios(SMLCS) has been improved to simulate the scenarios of land cover in Eurasia. On the basis of the observation monthly climatic data observed from 2127 weather stations in Eurasia during 1981–2010, the climatic scenarios data of RCP26, RCP45 and RCP85 scenarios released by CMIP5, and the land cover current data of Eurasia in 2010, the land cover scenarios of Eurasia were respectively simulated. The results show that most land cover types would generally have similar changing trends in the future, but with some difference in different periods under the three scenarios of RCP26, RCP45 and RCP85. Deciduous needleleaf forest, mixed forest, shrub land, wetlands and snow and ice would generally decrease in Eurasia during 2010–2100. Snow and ice would have the fastest decreasing rate that would decrease by 37.42% on average. Shrub land would have the slowest decreasing rate that would decrease by 5.65% on average. Water bodies would have the fastest increasing rate that would increase by 28.78% on average. Barren or sparsely vegetated land would have the slowest increasing rate that would increase by 0.76%. Moreover, the simulated results show that climate change would directly impact on land cover change in Eurasia.