白鹤滩层间错动带微结构特性及其化学改性初探

白鹤滩水电站层间错动带结构疏松、性状软弱、空间展布范围大、力学强度低,严重影响着地下厂房洞室的稳定性。为了揭示并改良层间错动带的力学特性,首先通过矿物成分分析试验、扫描电镜试验和压汞试验,从微观结构角度对层间错动带的矿物组成特征、颗粒排列规律、孔隙分布规律进行了详细的研究,阐明了层间错动带的微观结构特性及其对灌浆材料选择的影响,进而开展了层间错动带化学溶液浸泡对比试验。试验表明,硅酸钠溶液可以有效改善层间错动带的完整性,明显提高层间错动带的弹性波速、抗压强度、弹性模量和凝聚力。其研究结果对白鹤滩层间错动带的工程加固和改性设计具有一定的借鉴意义。     

Culture observation and molecular phylogenetic analysis on the blooming green alga Chaetomorpha valida (Cladophorales, Chlorophyta) from China

The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphological characters of C. valida. Results reveal that gametophytic filaments often produce lateral branches under laboratory culture conditions, suggesting an atypical heteromorphic life cycle of C. valida between unbranched sporophytes and branched gametophytes, which differs from typical isomorphic alternation of Chaetomorpha species. The shape of the basal attachment cell, an important taxonomic character within the genus, was found variable depending on environmental conditions. The 18S rDNA and 28S rDNA regions were used to explore the phylogenetic affinity of the taxa. Inferred trees from 18S rDNA sequences revealed a close relationship between C. valida and Chaetomorpha moniligera. These results would enrich information in general biology and morphological plasticity of C. valida and provided a basis for future identification of green tide forming algae.     

四川省人工影响天气业务系统功能

介绍了四川省人工影响天气业务技术系统的组成功能及应用情况。该系统集成度和自动化程度比较高、实时性和实用性强、业务化运行稳定;实现了多种尺度和不同种类信息的实时采集、快速传输和直观显示,具有业务管理、作业预警信息发布、作业决策指挥、作业效果评估结果及时发布等多种功能。该系统的运用,加强了人工影响天气业务的管理,大大的提升了人影业务工作的效率。      

三种海洋浮游微藻的分子鉴定及培养条件研究

采用分子生物学手段结合形态特征对海洋中生活着的浮游单细胞海藻进行准确无误的分类鉴定,正在成为一种普遍接受的方式。这样做的前提是首先需要从海水中分离得到纯藻株, 掌握它们的生活条件, 获得生物量, 并进而完成鉴定。作者对一株裸甲藻类似种和两株新分离的赤潮单细胞海藻进行了分离、培养和鉴定。核糖体18S RNA 基因(18S rDNA)和转录单元内间隔区(ITS)序列分析结果显示这三株藻分别为共生甲藻(Symbiodinium sp.)、锥状斯氏藻(Scrippsiella trochoidea)和赤潮异弯藻(Heterosigma akashiwo)。作者以广泛使用的光密度值A₆₈₀作为衡量藻体生物量变化的指标, 研究了这三种藻在不同培养条件下的生长。结果表明, 在批次培养中, 共生甲藻、锥状斯氏藻和赤潮异弯藻的生物量都在22℃达到最大, 分别为9.28×10⁵个/mL、7.9×10⁴个/mL 和4.75×10⁵个/mL; 强光和长时间光照促进生长, 但锥状斯氏藻在强光下更早进入衰退期; 三种藻都表现出较强耐受盐度变化的能力,在盐度为15～36 的培养液中生长良好; 营养实验表明, 使用882 μmol/L 的NO₃^- 和36.2 μmol/L 的PO₄^3-能够维持三种海藻的快速生长。     

7个海星动物线粒体基因组比较及基因变异位点分析

与单基因相比,线粒体基因组是一个完整的体系,具有信息量丰富等优点,在过去的十几年间被广泛地应用于后生动物关键类群的分子系统发育和群体遗传学的研究.本论文综合分析了海星纲7个物种(多棘海盘车、赭色豆海星、多棘槭海星、砂海星、长棘海星、棘冠海星和海燕)线粒体基因组全序列,全面揭示了海星纲线粒体基因组的基本特征.海星线粒体基因组均编码后生动物线粒体基因组标准的37个基因.7个海星线粒体基因组的基因排列完全一致;与海胆纲及海参纲楯手目线粒体基因组的基因排列相比,海星线粒体基因组的基因排列存在4.6 kb长片段的倒位.长棘海星属13个线粒体蛋白质编码基因的非同义替换率(Ka)与同义替换率(Ks)比值都低于1.000 0(为0.006 0～0.221 9),显示出较强的负(纯化)选择.对海星纲线粒体基因组的基因变异位点分析结果表明,nad5、nad4基因可作为备选的分子标记,应用于海星纲群体遗传学的研究中.同时,在长棘海星属线粒体基因组变异位点分析中,nad5、nad4基因仍然可作为备选的分子标记,用于分析长棘海星不同群体及物种之间的生物多样性,为合理利用其生物资源及其生物多样性的保护提供基础资料.     

Molecular identification and culture observation on <Emphasis Type="Italic">Acrochaete leptochaete</Emphasis> (Chaetophoraceae,Chlorophyta) from China

Acrochaete leptochaete (Huber) Nielsen (Chaetophoraceae, Chlorophyta) was isolated from the macroalgae Chaetomorpha collected from intertidal pools in Rongcheng, Shandong, China. 18S rDNA combined with ITS regions were used to ascertain the morphological identification of the isolated material. Based on the unialgal culture, asexual reproduction and growth characteristics of A. leptochaete were investigated over wide ranges of temperature and irradiance. Results revealed that asexual reproduction of A. leptochaete could be realized by biflagellate zoospores. The zoospores germinated directly to give self- replicating generations. Zoospore germination was bipolar. A temperature range from 13-21°C and a lower irradiance of 36 μmol/(m2·s) were most favorable for the growth of A. leptochaete. Thallus organization, an important taxonomic criterion for the genus Acrochaete, was affected markedly by temperature and irradiance. Our results extend the knowledge about the species’ general biology and its morphological plasticity. For classification and identification of a simple microphytic algae like A. leptochaete, which are traditionally placed in the class Chaetophoraceae, we propose that molecular tools associated with culture observations are applied.     

基于多参数指标的长江口滨岸多环芳烃来源辨析(英文)

Samples of suspended particulate matters(SPMs),surface sediment and road dust were collected from the Yangtze estuarine and nearby coastal areas,coastal rivers,and central Shanghai.The samples were analyzed for the presence of 16 polycyclic aromatic hydrocarbons(PAHs)in the USEPA priority-controlled list by GC-MS.The compound-specific stable carbon isotopes of the individual PAHs were also analyzed by GC-C-IRMS.The sources of PAHs in the SPMs and surface sediments in the Yangtze estuarine and nearby coastal...     

高分散性、粒度高正态分布氢氧化镁的制备研究进展

近年来Mg(OH)2的改性研究受到广泛重视;对水热处理技术和表面改性手段处理Mg(OH)2的研究现状进行概述,并讨论制备超细粉体改性Mg(OH)2的影响因素。     

A method for absorption compensation based on adaptive molecular decomposition

In this paper, we present a new method for seismic stratigraphic absorption compensation based on the adaptive molecular decomposition. Using this method, we can remove most of the effects resulting from wavelets truncation and interference which usually exist in the common time-frequency absorption compensation method. Based on the assumption that the amplitude spectrum of the source wavelet is smooth, we first construct a set of adaptive Gabor frames based on the time-variant properties of the seismic signal to transform the signal into the time-frequency domain and then extract the slowly varying component (the wavelet’s time-varying amplitude spectrum) in each window in the time-frequency domain. Then we invert the absorption compensation filter parameters with an objective function defined using the correlation coefficients in each window to get the corresponding compensation filters. Finally, we use these filters to compensate the time-frequency spectrum in each window and then transform the time-frequency spectrum to the time domain to obtain the absorption-compensated signal. By using adaptive molecular decomposition, this method can adapt to isolated and overlapped seismic signals from the complex layers in the inhomogeneous viscoelastic medium. The viability of the method is verified by synthetic and real data sets.