Continuous flow analysis of dissolved total phosphorus in seawater by UV-K2S2O8 online digestion method

Several methods for analysis of dissolved total phosphorus in seawater were reviewed. Discussions were focused on UV irradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus determination methods presently. The compounds used for the phosphorus recovery test were categorized into three groups according to their chemical structure. It was found that low power UV irradiation can decompose P-O-C or P-C bonds efficiently but may be inefficient for P-O-P bonds. Heating-bath in acid condition is useful for decomposing P-O-P bonds. Using the continuous flow analysis system (Auto-analyzer Ⅱ), UV digestion and heating-bath, series experiments were carried out based on the above analysis. Eleven model compounds were employed for the phosphorus recovery test and the factors influencing the decomposition efficiency of dissolved compounds containing phosphorus were clarified. Finally, the optimal design for determination of dissolved total phosphorus in seawater based on the routine continuous flow analysis system was presented. For the organic mono-phosphate, the recovery is more than 90% and a recovery of 33%～51% was obtained for inorganic or organic polyphosphates. Up to now, this is the highest decomposition efficiency for dissolved phosphorus based on the continuous flow analysis system.     

海珍品养殖水质微机自动监测系统

化学传感器用于海洋增养殖业水质环境监测领域，它与传统的物理传感器相比具有许多不便之处，如易漂移、难校准、受环境影响大等问题。因此在现场测量和实现长期连续监测方面受到了限制。文中主要介绍了海珍品养殖水质自动监测系统利用先进的电化学传感器技术（863－818－01－01课题研究成果）与计算机技术相结合，实现了海珍品养殖中必须监测的常规化学要素的现场定点长期连续监测，为水产养殖业提供实时的数据服务。     

Similar reproductive cycles and life-history traits in congeneric limid bivalves with different modes of nutrition

We have studied two congeneric limid bivalves, Acesta species novum and Acesta excavata (Bivalvia: Limidae), that live in similar physical conditions but use different food sources. Acesta sp. nov. live on the giant siboglinid tubeworm Lamellibrachia luymesi at cold seeps and feed on their eggs, a continuous food source that ultimately is derived from chemosynthesis, whereas A. excavata relies on planktonic food of photosynthetic origin, which varies seasonally. We hypothesized that these two species might show differences in the periodicity of reproduction; specifically, we predicted that A. sp. nov. would breed continuously and that A. excavata would demonstrate an annual reproductive cycle. Our hypothesis was refuted, as both species have a semi‐continuous reproductive cycle. Food quality, quantity or seasonality had no clear effect. Reproductive adults are functionally gonochoristic. Females broadcast buoyant eggs with an average size of 179 μm in A. sp. nov. and 160 μm in A. excavata. Both the size of the larval shell and the size of the spawned eggs are suggestive of pelagic lecithotrophic development. Both species also appear to be protandric hermaphrodites, changing from male to female at approximately 77 and 90 mm shell height, respectively, although not all individuals change sex. In the material investigated in this study there was a biased sex ratio favouring males.     

旋转层化二维海洋波动连续谱的波包特征分析

对旋转层化二维海洋波动中重力惯性波和涡旋波连续谱波包的结构以及演变特征作了计算和分析,并得到以下结论:这两类波动的结构与演变各不相同。连续谱波包的演变不但依赖基本场的分布,而且还依赖初始扰动的结构。根据初始场的不同,扰动可衰减,也可先增长、再衰减,有时增长还很大,但其最终是衰减的。连续谱波包的结构随时间变化,然而构成该波包的连续谱其结构则不随时间变化,这是两者的最大差异。连续谱波包的上述演变特性表明,在有限时段扰动的演变中连续谱是不能被忽略的,在海洋波动演变中连续谱和离散谱的作用均须予以考虑和重视。     

长江中下游地区2010/2011年秋冬春连旱成因再分析

基于长江中下游70个气象站点逐月降水和CRU逐月降水格点数据、NOAA逐月海温数据以及NCEP/NCAR逐月再分析数据,分析长江中下游地区2010/2011年秋冬春连旱的时空特征,进一步探讨此次连旱的可能成因。结果表明:(1)2010/2011年长江中下游区域性秋冬春连旱事件始于2010年10月,止于2011年6月,其中2011年春季(特别是4月)干旱程度最重,大部分地区为重旱和特旱;(2)此次连旱事件受拉尼娜事件影响,赤道西太平洋海温异常偏暖、冬春季印度洋和黑潮区海温异常偏冷,使得Walker环流上升支和局地Hadley环流显著增强、西太平洋副热带高压显著偏弱,长江中下游地区始终处于下沉气流控制下,且水汽输送减少;(3)自2010年秋季,乌拉尔山阻塞高压、贝加尔湖阻塞高压和鄂霍次克海阻塞高压轮番控制中高纬度地区,使得西伯利亚高压和阿留申低压持续增强,冬季风自秋季便开始影响中国东部地区,并一直持续到2011年春季,长江中下游地区受干冷的偏北气流控制,进一步阻碍了来自低纬的暖湿气流向本地输送,不利于降水的形成。     

海平面变化与城市安全——以上海市为例

从流域—河口—海洋连续水动力系统角度,分析长江河口吴淞潮位记录(1912～2000年)中的理论海平面变化、构造沉降、三峡大坝导致的河口河槽冲刷、城市地面沉降、河口深水航道整治与促淤围垦工程导致雍水的复合效应,预测2030年长江河口地区海平面上升10～16cm.海平面上升将导致近岸海域潮位上升、潮流流速增大,设计高潮位和设计波高抬升,海塘防潮和供水安全标准降低.为此,提出上海市应对相对海平面上升的近期、中期和远期应对行动指南.     

联合Topex/Poseidon与Envisat高度计数据监测我国大陆地表覆盖变化

首次联合Topex/Poseidon(T/P)与Envisat高度计数据,提取了2002年5月至2005年5月期间两高度计Ku波段的后向散射系数,采用连续张力曲线样条格网化方法,有效地解决了数据稀疏区容易出现极值以及对数据密集区进行格网化时不平滑的问题,得到了格网时间序列数据,分析了T/P与Envisat两高度计后向散射系数的统计差异,进而讨论了我国陆地覆盖的空间分布特征,定性地研究了内蒙古高原、华北平原、东北平原、青藏高原、云贵高原、黄土高原、长江中下游平原的后向散射系数的成因机制及其随时间的演化规律,研究结果可为因自然灾害和环境变化而导致地表覆盖变化的监测提供决策支持。     

自动电位滴定仪应用于地下水六项指标的连续滴定

地下水中六项指标(pH、总碱度、氯离子、钙离子、镁离子及硫酸根)的分析需要对每个指标单独进行取样检测,步骤繁琐且效率较低。同时总碱度、氯离子、钙离子、镁离子及硫酸根通常采用手动目视滴定,检测结果存在人为操作误差,精密度和准确度相对较差。本文建立了准确快速测定地下水中六项指标的分析方法,只需2次取样,采用自动电位滴定仪自动判定终点,加液器可精确控制标准溶液加入量至0. 1μL,并且通过调整检测顺序、溶液酸度和加入掩蔽剂的方法消除相互干扰。本方法的加标回收率为93. 5%～120. 0%,相对标准偏差(RSD,n=10)为0. 18%～11. 33%。电位滴定法得到的数据相比标准方法的平行性更好,尤其是当所测定水样较为浑浊或者有颜色时测定数据更稳定。     

Subdivision and fragmentation of land holdings and their implication in desertification in the Thar Desert, India

Analysis of data at the household level in Khabra Kalan village in the Thar desert of India revealed that the land holding size is halved every 20–30 years due to subdivision of land holdings. The subdivision is caused by the equal sharing among sons at the time of inheritance based on the succession laws, and attributed to the increase in the village population. The shrinking land holdings resulted in a shortfall of food on small farms; 12% in cereals and 42% in pulses, promoted continuous cultivation and the increase of monoculture, and deteriorated the land productivity through its effect on the soil fertility and land management.     

多维连续参数的随机试验蚁群算法优化反演分析

针对一般蚁群算法难以求解优化反演中的多维连续参数优化问题,借鉴进化思想,提出随机试验蚁群算法求解多维连续参数全局优化问题的方法。该方法主要运用随机试验求出每个参数的任一水平对目标函数的影响度,以此影响度为蚂蚁选择下一个参数水平的能见度,从而确定参数水平被选中的概率。同时考虑到当参数被划分的水平很多时目标函数收敛较慢的缺点,提出用方差分析法来确定参数的水平对目标函数的影响是否显著,将对目标函数影响不显著的参数水平其信息素设置为很小的值,从而加速目标函数的收敛。通过对一个岩土工程优化实例,表明了该算法的有效性。