Climate–growth relationship stability of <Emphasis Type="Italic">Picea crassifolia</Emphasis> on an elevation gradient,Qilian Mountain,Northwest China

Climate affects Picea crassifolia growth and climate change will lead to changes in the climate–growth relationship (i.e., the “divergence” phenomenon). However, standardization methods can also change the understanding of such a relationship. We tested the stability of this relationship by considering several variables: 1) two periods (1952–1980 and 1981–2009), 2) three elevations (2700, 3000, and 3300 m), and 3) chronologies detrended using cubic splines with two different flexibilities. With increasing elevation, the climatic factor limiting the radial growth of Picea crassifolia shifted from precipitation to temperature. At the elevation of 2700 m, the relationship between radial growth and mean temperature of the previous December changed so that the more flexible spline had a greater precipitation signal. At the elevation of 3000 m, positive correlation of radial growth with mean temperature and precipitation in September of the previous year became more significant. At the elevation of 3300 m, positive correlation between radial growth and precipitation of the current summer and the previous spring and autumn was no longer significant, whereas the positive correlation between radial growth and temperature of the current spring and summer strengthened. The detrending with the most flexible spline enhanced the precipitation signal at 2700 m, while that with the least flexible spline enhanced the temperature signal at 3300 m. All results indicated that the divergence phenomenon was affected by the climatic signals in the chronologies and that it was most dependent on the detrending method. This suggests it is necessary to select a suitable spline bootstrap for studies of growth divergence phenomena.     

基于转录组测序的方斑东风螺单核苷酸多态性位点挖掘及功能注释

【目次】了解方斑东风螺中响应LPS刺激的SNP位点及SNP所在基因SNP-Unigenes的功能。【方法】使用SOAPsnp软件分析不同时间条件下转录组数据中的SNP位点,使用GO、COG和KEGG数据库进行功能注释。【结果】转录组数据中共挖掘到673 782个SNP位点,分布在110 869条SNP-unigenes序列上。SNP类型分析表明,转换位点发生的频率远高于颠换位点,且6种单碱基变异类型中以A/G转换发生概率最大。有5866条SNP-unigenes富集到298个KEGG子集中,其中以"内吞作用"子集中富集的SNP-Unigenes最多,共富集182条。     

基于数值模型的地下水水位预警体系研究——以临汾盆地为例

地下水是中国许多城市主要的供水水源,对地下水的过量开采将导致地下水降落漏斗、地面沉降和地裂缝等环境地质问题.进行地下水水位预警体系的研究对于合理开发和有效利用地下水资源具有重要的现实意义,笔者以临汾盆地为例,根据当地的水文地质条件,利用数学模型建立了地下水水位预警体系,研究结果可为当地水资源的可持续利用提供科学依据.     

Nutrient effects of broodstocks on the larvae in Patinopecten yessoensis

Patinopecten yessoensis is a commercial valuable species. This study deals with the effect of nutrient effects of the broodstock(mainly ovaries) on the larvae. Concentrations of total carbohydrate, total protein and total lipid in the gonads of P. yessoensis from three Hatcheries(Hatchery 1, Hatchery 2, and Hatchery 3) were determined before and after spawning. The relationship between the nutrient concentration in ovaries before spawning(BC) and that of larvae(LC) was assessed as well as the change in nutrient levels in ovaries after spawning(DC). Results indicate that the BC of total carbohydrate(7.66%) and total lipid(14.48%) in ovaries were significantly higher than in testes(5.20%, 5.20% respectively), whereas the BC of total protein in the ovaries was lower(61.76%) than in the testes(81.67%). The different gonadal composition suggests the different nutrient demands between male and female broodstocks in breeding season. P atinopecten yessoensis gonads contained a higher proportion of lipids, in comparison to other bivalves, which might be a response to the low ambient water temperatures. Further analysis of fatty acids showed that the concentrations of n-3PUFA, EPA and DHA in larvae(LC) were positively correlated with BC and DC, indicating the significant nutrient influence of broodstocks on the larvae. As these fatty acids are important in metabolism, and have been demonstrated to be influential to the viability of the larvae, larval growth and the settlement, spat growth, and juvenile survival in many bivalves, they could possibly be used as indexes to evaluate, and predict condition of broodstocks and larvae.     

沉井下沉阻力离心模型试验研究

如何正确计算沉井的下沉阻力一直是沉井结构设计的难点,为了更加深入地研究沉井下沉阻力及其分布规律,通过离心机模型试验分别对4组不同埋深工况下的沉井进行了下沉模拟,对沉井侧壁土压力、刃脚斜面土压力、刃脚踏面土压力、沉井内外土面沉降进行了分析。研究结果表明：侧壁土压力随入土深度的增加呈先增大后减小的趋势,可采用分段函数形式对其大小及分布形式进行简化计算;刃脚斜面土压力呈三次多项式分布形式;随着刃脚入土深度的增加,刃脚斜面与踏面土阻力均显著增大,而单位投影宽度刃脚斜面与踏面土阻力比基本保持不变;沉井下沉会导致井外土面沉降,井内紧靠沉井内壁的土面沉降,离沉井内壁有一定距离的土面隆起。上述试验与分析成果可为理论研究与工程设计提供参考。     

Investigating variable stars in the open cluster NGC 1912 and its surrounding field

In this work,we studied the variable stars in the open cluster NGC 1912 based on the photometric observations and Gaia DR2 data.More than 3600 CCD frames in B,V,R filters were reduced,and we obtained the light curves that span about 63 hours.By analyzing these light curves,we detected 24 variable stars,including 16 periodic variable stars,seven eclipsing binaries and one star whose type is unclear.Among these 24 variable stars,11 are newly discovered,which are classified as sixγDoradus stars,oneδScuti star,three detached binaries and one contact binary.We also confirmed 13 previously known variable stars.Based on cluster members identified by Cantat-Gaudin et al.(2018),we inferred cluster memberships for these detected variable stars.Using Gaia DR2 data,we plotted a new color-magnitude diagram for NGC1912,and showed the nature of variable cluster members in kinematical properties and heliocentric distance.Among the 24 variable stars,seven variables are probable cluster members,which show homogeneity in kinematic characters and space position with the established cluster members.Four of the seven variable cluster members are the previously discovered stars,consisting of twoγDor stars and twoδSct stars.The remaining three variable cluster members,which are allγDor stars,are firstly detected in this work.The main physical parameters of these variable cluster members estimated from the color-magnitude diagram are log(age/yr)=8.75,[Fe/H]=-0.1,m-M=10.03 mag,and E(B-V)=0.307.     

围岩内部多点位移量测的新方法

地下工程围岩内部多点位移量测一直是一种投资大且较为复杂的量测项目。利用收敛计进行围岩内部多点位移量测的方法 ,具有简单方便、投资少、精度高等优点 ,是一种非常实用的量测方法     

X-ray diffraction investigation of native Si-Fe alloy minerals from Luobusha, Tibet

The origin of native Si-Fe alloy mineral is thought to be related with mantle and aerolite. The native Si-Fe alloy minerals from podiform chromites of the Luobusha ophiolite in the Yarlong Zangbo suture zone were examined by a new method for powder-like diffractograms of small single crystals, using an SMART APEX-CCD area-detector X-ray diffractometer. The powder diffraction pattern shows that the minerals are composed of FeSi, FeSi₂, β-FeSi₂ and native silicon. The association of these minerals suggests that the crystallization order of the mineral may be from early to late FeSi→FeSi₂→native silicon, accompanied by gradually increasing deoxidization. Translated from Acta Petrologica et Mineralogica, 2005, 24(5): 453–456 [译自: 岩石矿物学杂志]