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101.
以壳聚糖和CuCl2·2H2O为原料,分别采用直接负载法和吸附法成功制备了壳聚糖/纳米铜复合微球,运用傅里叶变换红外光谱(FT-IR)、X-射线衍射(XDR)和扫描电镜(SEM)对催化剂结构进行了表征。以刚果红(CR)染料为目标污染物,评价了催化剂的制备方法、制备条件及氢转移催化反应条件对其催化性能的影响。结果表明,由直接负载法(CS/CuNPs)和吸附法(CS/CuNPs-X)制备的壳聚糖/纳米铜复合微球在CR染料浓度为100 mg/L,催化剂投加量为0.05 g,供氢体浓度为0.05 mol/L的氢转移催化反应条件下,催化反应进行180和60 min时CR脱色率可分别达95.8%和96.8%。CS/CuNPs-X比CS/CuNPs表现了更高的对CR氢转移催化反应的催化速率。两种催化剂催化还原CR染料的反应均符合准一级动力学模型。在连续循环使用10次后,CS/CuNPs和CS/CuNPs-X对CR的脱色率分别为93.9%和89.4%,表明催化剂具有良好的重复使用性能。 相似文献
102.
本研究分别在平潭青峰、坛南湾和闽江口琅岐岛采集18个老红砂样品、19个海滩砂样品以及40个河滩砂样品,并对这些样品进行粒度和稀土元素(REE)测量。结果发现老红砂与闽江口琅岐岛河口砂的稀土元素含量特征十分接近;分别对老红砂与闽江河口砂REE数据以及坛南湾海滩砂与闽江口砂(REE)进行了判别函数分析,老红砂的∑REE平均值为84.25μg/g,琅岐岛河口砂的∑REE平均值为89.81μg/g,相似性明显;坛南湾海滩砂的∑REE平均值为16.41μg/g,与闽江河口砂含量差别较大。研究表明:青峰老红砂沉积物主要来源于闽江口河口砂,末次间冰期暖湿气候下闽江输砂量增大,河口外沿岸流增强,大量河砂进入海坛海峡,在强劲的季风搬运下,沉积于平潭岛北部,形成以青峰为代表的平潭岛北部老红砂;而坛南湾海滩砂代表海洋波浪搬运的泥沙,不是老红砂的物源。 相似文献
103.
Phylogenetic analysis of epibacterial communities on the surfaces of four red macroalgae 总被引:1,自引:0,他引:1
Macroalgal surfaces are prone to being attached by bacteria. Epibacterial community structures on marine macroalgae are host-specific but temporally and spatially variable. In this study, we investigated the structure of epibacterial communities on the surfaces of four red macroalgae, Gracilaria lemaneiformis, Gloiopeltis furcata, Mazzaella sp. and Porphyra yezoensis, by analyzing the sequences of 16 S r RNA gene libraries. Healthy individuals of all macroalgae species were collected in winter from a farm at Dalian, China. The results showed that the epibacterial communities were mainly dominated by α-Proteobacteria, γ-Proteobacteria and Bacteroidetes. Deinococcus-Thermus, Spirochaetes and ε-Proteobacteria were also found. The majority of cloned sequences shared the greatest similarity to those of culturable organisms. A large portion of sequences from the α-Proteobacteria homed in Roseobacter clade, i.e., genera Ahrensia, Roseovarius, Litoreibacter, Octadecabacter, Thaiassobacter and Sulfitobacter, while members of Bacteroidetes mainly belonged to family Flavobacteriaceae. The cloned sequences could be separated into 66 OTUs at 0.01 distance value, and rare common OTUs were found among libraries. At genus level, Pseudoalteromonas dominated Gr. lemaneiformis and Gl. furcata libraries, accounting for 72.2% and 47.3%, respectively. Sulfitobacter dominated P. yezoensis library, accounting for 35.4%. A previously undefined cluster within Deinococcus-Thermus dominated Mazzaella sp. library, accounting for 24.6% of the all. These results indicated that a broad range of bacteria inhabited the surfaces of these macroalgae. 相似文献
104.
Phylogenomic analysis of transcriptomic sequences of mitochondria and chloroplasts for marine red algae (Rhodophyta) in China 总被引:1,自引:1,他引:0
JIA Shangang WANG Xumin QIAN Hao LI Tianyong SUN Jing WANG Liang YU Jun LI Xingang YIN Jinlong LIU Tao WU Shuangxiu 《海洋学报(英文版)》2014,33(2):86-93
The chloroplast and mitochondrion of red algae (Phylum Rhodophyta) may have originated from different endosymbiosis. In this study, we carried out phylogenomic analysis to distinguish their evolutionary lin-eages by using red algal RNA-seq datasets of the 1 000 Plants (1KP) Project and publicly available complete genomes of mitochondria and chloroplasts of Rhodophyta. We have found that red algae were divided into three clades of orders, Florideophyceae, Bangiophyceae and Cyanidiophyceae. Taxonomy resolution for Class Florideophyceae showed that Order Gigartinales was close to Order Halymeniales, while Order Graci-lariales was in a clade of Order Ceramials. We confirmed Prionitis divaricata (Family Halymeniaceae) was closely related to the clade of Order Gracilariales, rather than to genus Grateloupia of Order Halymeniales as reported before. Furthermore, we found both mitochondrial and chloroplastic genes in Rhodophyta under negative selection (Ka/Ks〈1), suggesting that red algae, as one primitive group of eukaryotic algae, might share joint evolutionary history with these two organelles for a long time, although we identified some dif-ferences in their phylogenetic trees. Our analysis provided the basic phylogenetic relationships of red algae, and demonstrated their potential ability to study endosymbiotic events. 相似文献
105.
B. Gudveig Baarli Mrio Cacho Carlos M. da Silva Markes E. Johnson Eduardo J. Mayoral Ana Santos 《Geological Journal》2014,49(1):90-106
Carbonate factories on insular oceanic islands in active volcanic settings are poorly explored. This case study illuminates marginal limestone deposits on a steep volcanic flank and their recurring interruption by deposits linked to volcaniclastic processes. Historically known as Ilhéu da Cal (Lime Island), Ilhéu de Baixo was separated from Porto Santo, in the Madeira Archipelago, during the course of the Quaternary. Here, extensive mines were tunnelled in the Miocene carbonate strata for the production of slaked lime. Approximately 10 000 m3 of calcarenite (−1 to 1ø) was removed by hand labour from the Blandy Brothers mine at the south end of the islet. Investigations of two stratigraphic sections at opposite ends of the mine reveal that the quarried material represents an incipient carbonate ramp developed from east to west and embanked against the flank of a volcanic island. A petrographic analysis of limestones from the mine shows that coralline red algae from crushed rhodoliths account for 51% of all identifiable bioclasts. This material was transported shoreward and deposited on the ramp between normal wave base and storm wave base at moderate depths. The mine's roof rocks are formed by Surtseyan deposits from a subsequent volcanic eruption. Volcaniclastic density flows also are a prevalent factor interrupting renewed carbonate deposition. These flows arrived downslope from the north and gradually steepened the debris apron westwards. Slope instability is further shown by a coral rudstone density flow that followed from growth of a coral reef dominated by Pocillopora madreporacea (Lamarck), partial reef collapse, and transport from a more easterly direction into a fore‐reef setting. The uppermost facies represents a soft bottom at moderate depths in a quiet, but shore‐proximal setting. Application of this study to a broader understanding of the relationship between carbonate and volcaniclastic deposition on oceanic islands emphasizes the susceptibility of carbonates to dilution and complete removal by density flows of various kinds, in contrast to the potential for preservation beneath less‐disruptive Surtseyan deposits. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
106.
红层“哑地层”划分对比方法——以东营凹陷南坡始新统为例 总被引:1,自引:0,他引:1
针对红层划分对比所面临的难题,在充分吸收前人研究成果的基础上,将现有的多种分层方法相互整合,彼此约束和印证,形成了一套科学、便捷的技术方法,即"接触关系明顶底、岩电特征找界面、多元融合定方案、地震约束建格架"的综合地层划分对比技术。该方法针对红层的特殊性,根据岩电特征对干旱气候的响应变化,充分利用了测、录井资料纵向上的连续性优势(避免了取样分析的局限),以及地震资料横向上的优势,有效地解决了红层纵向划分、横向对比的难题,在济阳坳陷东营凹陷南坡始新统沙河街组、孔店组的应用取得了良好效果。该方法可为其它地区同类复杂地层划分对比提供技术支持。 相似文献
107.
泰宁丹霞红层由铁钙质混合胶结的较松散固结红色砂砾岩构成,岩石胶结物中CaCO3含量较高,抗压强度极低、孔隙度和含水性均较高。当岩石遇水湿润或浸泡时,或者生物风化过程中受到各种动植物分泌的有机酸作用,岩石胶结物中CaCO3易溶解流失,促使丹霞红层进一步软弱松散。冬季水结冰之后体积会膨胀,所以岩层表面产生片状裂隙。通过裂隙的毛细管效应,孔隙-裂隙水由岩石内部向结冰的表面扩散,在表面张力作用下水呈表面积最小的球状。春季化冻时岩石沿球形片状裂隙自由剥落的片状风化,圆球形洞穴开始形成,随着四季交替,年复一年,间歇性结冰和融化过程,使得洞穴逐渐扩大,形成泰宁丹霞各种形态的洞穴奇观。 相似文献
108.
红色历史的集体记忆嵌入动态的地方建构和空间生产过程,成为地方性重构的有力素材。文章以云南省宾川县新庄红军村为例,通过参与式观察和访谈文本分析等质性方法,从地方性景观与话语的再建构,以及地方性情境创设的空间实践,探讨新庄村的地方性建构机制。研究发现:具体的地方要素在地方-记忆的互动关系中起中介承启作用。地方要素既促进红色旅游情境下记忆的唤起、存储与再创造,又对集体记忆重新建构的地方特质、意义与场所精神进行地方性元素表达。旅游情境创设与地方性展演使集体记忆不断得到投影、表达与重构,推动差异化的地方叙述与体验。 相似文献
109.
最佳小波包基的矿区植被及红边位置提取 总被引:1,自引:0,他引:1
小波包变换能同时对植被光谱信息的低频和高频分量进行分解,并能克服小波变换时间分辨率高而频率分辨率低的缺陷从而具有能够探测植被细微变化的优势。实验利用Hyperion高光谱影像对云南省普朗铜矿区植被像元的光谱进行最佳小波包基参量获取与植被信息识别,并在此基础上提出一种提取重金属污染下植被红边位置的最佳小波包基系数应用模型。研究结果表明基于最佳小波包基参量的植被信息识别及基于最佳小波包基系数的重金属污染探测具有可行性与一定优越性。 相似文献
110.
Scrippsiella trochoidea (Stein) Loeblich III was grown in a nitrogen-or phosphorus-limited batch culture system in laboratory. Growth rates and cellular
Chl-a were measured as functions of nitrate and phosphate concentrations. Growth rates were hyperbolic with both nitrate and
phosphate concentration and fit the Monod equation. The minimum cell quota of nitrogen and phosphorus and then the optimum
N∶P ratio ofS. trochoidea were estimated in this study. Measurement of phosphate concentration in Jiaozhou Bay suggest that phosphorus is the limiting
factor ofS. trochoidea growth.
Contribution No. 3679 from the Institute of Oceanology, Chinese Academy of Sciences.
Project 39790110 supported by NSFC, the study aslo supported by the National Climbing Project B (PDBG-7-2) and partly supported
by an MF grant from Hong Kong University of Science and Technology. 相似文献