Seasonal Changes in Soluble Carbohydrates, Starch, and Energy Content in Mediterranean Seagrasses

Abstract. In all scagrass species investigated, rhizomes were the main storage organs for soluble carbohydrate reserves, and the highest levels were found in Cymodocea nodosa (U cria ) A scherson . Sucrose was the primary soluble carbohydrate identified in Posidonia oceanica (L.) D elile , and Zostera noltii H ornem . This disaccharide was dominant in Cymodocea nodosa roots, as well as in its rhizome in winter. Myo-inositol was the main cyclitol in Zostera noltii. In Cymodocea nodosa leaves 1-chiro-inositol was the main sugar component; it was also present to a lesser extent in the roots and rhizomes. The amounts of glucose and fructose were correlated with growth to a certain extent in all species. Higher amounts of starch were stored in the rhizomes of Posidonia oceanica and Zostera noltii. The energy content of Mediterranean scagrasses was significantly higher than in tropical species. No distinct seasonal trend in energy content could be observed.     

Soluble organic compounds in fog and cloud droplets: what have we learned over the past few years?

We have recently set up a new procedure for characterising the water soluble organic compounds (WSOC) in fog water, for which information is still rather limited. Fog samples collected during the 1998–1999 fall–winter season in the Po Valley (Italy) were analysed following this procedure, which allows a quantitative determination of three main classes of organic compounds (neutral species, mono- and di-carboxylic acids, polycarboxylic acids), together accounting for ca. 85% of the total WSOC. This procedure also provides information on the main chemical characteristics of these three classes of compounds (functional groups, aliphatic vs. aromatic character, etc.). The enhanced chemical knowledge on fog/cloud chemical composition opens new scenarios as far as chemical and microphysical processes in clouds and fogs are concerned.     

硼酸盐化学(XXXV): MgO·3B2O3-18%MgSO4-H2O过饱和溶液0℃结晶动力学研究

首次研究了MgO·3B2 O3 1 8%MgSO4 H2 O过饱和溶液 0℃结晶动力学过程 ,得到三方硼镁石和章氏硼镁石两种固相及其结晶动力学方程。从多聚硼氧配阴离子多粒子共存的角度提出结晶反应机制 ,分析了制约硼酸镁盐析出的因素及不同电解质 (MgCl2 和MgSO4)对硼酸镁盐结晶过程的影响。     

中国侏罗系煤成油若干问题

在阐述了煤成油的概念，总结和评述了煤生油显微组分，生油门限，生油范围和生油高峰等问题后，本文通过吐哈等盆地侏罗系煤生油显微组分组成特征，可溶有机质演化，成熟度和有机质丰度，油源及原油成熟度对比；含煤岩系中煤层和泥岩的厚度及总量和煤及泥岩最高沥青和总烃转化率的对比； 其族组成和煤成原油的族组成特征的对比，提出了中国侏罗系煤成油盆地中泥岩比煤层对煤成油田形成有大的贡献看法。     

Vicissitude of Sogo Nur and environmental-climatic change during last 1500 years

Lakes in arid zone are sensitive to climatic changes. The lacustrine sediment sequence in Sogo Nur has well and truly recorded climatic events such as the Sui-Tang Dynasty Warm Period, the Song-Liao Dynasty Cold Period, the Medieval Warm Period, the Little Ice Age and the 20th Century Warm Period. Commonly, the climate in warm Periods was relatively humid,accordingly the lake area extended and water level rose, and vice versa. Apart from climatic change, human activity is also an important factor of influencing lake vicissitude, and they played the dominant role alternatively during different periods; the factor of climatic change predominated in historical period, while since the beginning of the 20th century the utilization of water resources by human has became decisive.     

药用滑石粉酸中可溶物测定方法考察

考察药用滑石粉酸中可溶物测定方法的重复性、耐用性 ,分析主要影响因素。比较酸溶物提取液滤过介质对测定结果差异的影响 ;采用重量法随机测定酸溶物含量和室间差异。两种滤过介质处理对测定结果没有显著差异 ;室间测定结果没有显著差异 ;30批样品平行测定结果的 RSD值范围为 0 %～ 18.2 %。酸中可溶物测定法存在重复性和耐用性不佳的问题 ,应相应调整酸中可溶物含量限度     

Water soluble components of PM10 Chongqing, China

The concentrations of water soluble ions (Na⁺, NH₄ ⁺, K⁺, Mg²⁺, Ca²⁺, NO₃ ^-, Cl^-, and SO ₄ ^2- ) in PM₁₀ samples collected on cellulose filters by a medium-volume cascade impactor were determined, which were obtained from three kinds of areas in Chongqing: industrial area (Jiulongpo district), commercial and residential area (Jiangbei district) and background area (Jinyun Mountain in the Beibei district). The results showed that except for the background site, the annual average values of PM₁₀ are 23% – 61% higher than the national air quality standard (GradeII) (0.1 mg/m³), even that the value of the control site is still 20% higher than American standard (0.05 mg/m³). This implied that serious pollution of fine particles occurred in Chongqing. Nine kinds of soluble ions in water of PM₁₀ were analyzed by ion chromatography (IC) and the annual average concentrations follow the order of [SO ₄ ^2- ] > [NO³ _-] > [Cl^-] > [F^-], and [Ca²⁺] > [NH₄ ⁺] > [K⁺] > [Na⁺] > [Mg²⁺]. Their values were different in these areas: the industrial area > the commercial and living area > the control area. As for NH_{4 +}, K⁺, Ca²⁺, NO₃ ^- and SO ₄ ^2- , their seasonal average concentrations show a similar variation trend: the values in spring and fall were higher than those in summer and winter. The seasonal average concentrations of [Cl^-], [F^-], [Na⁺] and [Mg²⁺] are much lower than those of other ions. However, the concentrations of [Na⁺] changed more greatly in different seasons than those of the other three ions. Correlation coefficients showed that the three areas have been polluted by coal smoke and dust to different extents, while some local resources of pollution should be taken into consideration as well.     

南水北调中线突发水污染事件的快速预测

依据南水北调中线干渠资料,开展了正常输水情况下串联明渠内可溶污染物浓度分布规律数值模拟研究。采用数值模拟、数学归纳和统计分析方法,提出表征污染物输移扩散特征的峰值输移距离、污染带长度和峰值浓度的快速预测公式;通过示范工程验证了快速预测公式的可行性。结果表明:①串联明渠内,峰值输移距离随渠道流速减小而减小,并且污染带长度增加值随明渠内流速减小而减小,但是峰值浓度随明渠流速减小而增加;②快速预测公式计算结果与现场试验实测结果的误差均不到15%,证明了快速预测公式的合理性和可行性。这些研究结果为南水北调中线工程突发可溶性水污染事件应急预警方案的制定提供了科学依据。     

海洋沉积物可溶铁测定条件的探讨

海洋沉积物可溶铁Fe~(3+)/Fe~(2+)比值,已被海洋地质工作者作为海洋油气化探的一项间接指标应用于东海油气化探中。这种铁的含量受提取酸的种类、浓度、样品微沸时间、放置时间等条件的影响。必须采用统一的可溶铁测定方法,只有在同一标准条件下测定的海洋沉积物可溶铁结果才有对比意义。     

合浦珠母贝贝壳珍珠层EDTA可溶性基质蛋白对无定形碳酸钙稳定性的影响

通过红外光谱、扫描电镜、能谱等方法探讨了合浦珠母贝贝壳珍珠层EDTA可溶性基质蛋白(ESM)对无定形碳酸钙(ACC)晶型转化的影响。试验结果显示,合浦珠母贝贝壳珍珠层ESM在镁离子存在的条件下能够显著抑制ACC的转化,并减少最终诱导形成的方解石中的镁离子含量。同时,珍珠层ESM具有调节方解石晶体晶貌的作用。