吉林省短时强降水天气的中尺度特征及概念模型

利用2005-2012年吉林省逐时降水资料及相应的北半球高空、低空、地面观测资料,采用中尺度分析方法分析了吉林省短时强降水的中尺度特征,总结了冷涡影响类、高空槽类、副高后部类三类短时强降水天气的中尺度概念模型,为预报员今后预报此类天气提供参考和技术支持。     

WRF模式对福建沿海风电场风速预测的效果分析

在WRF模式中选取不同的边界层、近地面层以及陆面过程参数化方案,设计了4种不同物理过程参数化方案,组合模拟福建沿海某测风塔站2010年1月1—11日和7月1—11日的逐时风速,将数值模拟结果和同期测风塔观测数据进行对比,以寻求最佳参数化方案。经分析比较,采用MYJ边界层方案,Monin-Obukhov近地面层方案以及Noah陆面过程方案的方案2模拟效果最好。使用该方案对2010年1月和7月的风速进行模拟,按不同风速级别分别对数值模拟结果进行对比分析,结果表明:方案2对6~15m/s风速模拟的平均相对误差在20%左右,能够满足风电预测的精度需求;而对0~6m/s风速模拟的误差相对较大,这可能是由于模式地形分辨率不够精细以及风塔所处海陆交界处的特殊位置,使低风速容易受地面扰动以及海陆气流影响所致。     

Effects of an artificial oyster shell reef on macrobenthic communities in Rongcheng Bay,East China

An artificial oyster shell reef was deployed in Rongcheng Bay, East China. However, the effects of this reef on the surrounding macrobenthic communities were unknown. We compared sedimentary factors, macrobenthic biomass, abundance, and community composition and ecological indicators between the reef and non-reef areas over a one year period. The mean values for chlorophyll a （Chl a）, total organic matter （TOM）, total organic carbon （TOC）, and total nitrogen （TN） content in surface sediments in the reef area were slightly higher than those in the non-reef area. The Chl a levels differed significantly between the two areas, but the TOM, TOC, and TN were not significantly different. The abundance of crustaceans was significantly different between the two areas, but the abundance and biomass ofpolychaetes, echinoderms, mollusk did not differ significantly. The permutational multivariate analysis of variance （PERMANOVA） revealed that the macrobenthic community differed significantly through time and analysis of similarity multivariate analyses （ANOSIM） revealed that the macrobenthic community differed significantly in some months. The ecological indicators revealed that the environmental quality of the reef area was slightly better than that of the non-reef area. Overall, our results suggest that the artificial oyster shell reef may change the macrobenthic community and the quality of the environment. Despite the lack of an effect in the short term, long-term monitoring is still needed to evaluate the effects of artificial oyster shell reefs on macrobenthic communities.     

Combined effects of light intensity and NH^＋4-enrichment on growth,pigmentation, and photosynthetic performance of Ulva prolifera （Chlorophyta）

The aim of this study was to investigate the effects of light intensity and enhanced nitrogen supply on the growth and photosynthesis of the green-tide macroalga, Ulva prolifera. Thalli of U. prolifera were grown in natural or NH 4 +-enriched seawater under two different light intensities for 7 days, and then the growth rate, pigmentation, and photosynthetic performance of the thalli were evaluated. The results show that the relative growth rate(RGR) was markedly higher under the high light level than under the low light level. Enrichment with NH 4 + enhanced the RGR under high light intensity, but did not affect RGR under low light intensity. In low light conditions, NH 4 +-enrichment resulted in a marked decrease in the maximal photosynthetic rate( P m) and the maximum carbon fixation rate( V max), but it did not affect the half saturation constant for carbon( K 0.5) or the ratio of V max to K 0.5, which reflects the carbon acquisition efficiency. In high light conditions, P m, K 0.5, and the dark respiration rate( R d) increased under NH 4 + enrichment, but V max and the V max / K 0.5 ratio decreased. Regardless of the light intensity, NH 4 +-enrichment did not affect the apparent photosynthetic efficiency( α), which refl ects the ability of the alga to use light energy at low light levels. Under both low and high light intensities, the chlorophyll a(Chl a), chlorophyll b(Chl b), and carotenoids(Car) contents in thalli were higher in NH 4 +-enriched than in natural seawater, except that there was a decrease in the Chl b content of thalli in NH 4 +-enriched seawater under low light intensity. Therefore, NH 4 + enrichment improved the growth and photosynthetic performance of U. prolifera under high light intensity, but not under low light intensity. We discuss the possible mechanisms underlying these physiological responses.     

Effect of copper on the growth of shrimps Litopenaeus vannamei: water parameters and copper budget in a recirculating system

Shrimps( Litopenaeus vannamei) were intensively cultured in a recirculating aquaculture system for 98 days to investigate effects of 0.3 mg/L Cu on its performance, Cu budget, and Cu distribution. Shrimps in Cu-treated systems had greater mean final weight(11.10 vs 10.50 g), body length(107.23 vs 106.42 mm), survival rate(67.80% vs 66.40%), and yield(6.42 vs 5.99 kg/m 3), and lower feed conversion ratio(1.20 vs 1.29) than those in control systems but the differences were not significant. Vibrio numbers remained stable(10 4 –10 6 colony forming units/mL) in the rearing tanks of both control and treated systems. Total ammonium-N, nitrite-N, nitrate-N, pH, chemical oxygen demand, 5-day carbonaceous biochemical oxygen demand, and total suspended solids were similar in controls and treatments. Dissolved Cu concentration in the treated systems decreased from 0.284 to 0.089 mg/L while in the control systems it increased from 0.006 2 to 0.018 mg/L. The main sources of Cu in the treated systems were the artificially added component(75.7% of total input), shrimp feed(21.0%), water(2.06%), and shrimp biomass(1.22%). The major outputs of Cu occurred via the mechanical filter(41.7%), water renewal(15.6%), and draining of the sediment trap(15.1%). The foam fractionator removed only 0.69% of total Cu input. Harvested shrimp biomass accounted for 11.68% of Cu input. The Cu concentration of shrimps in the Cu-treated systems(30.70 mg/kg wet weight) was significantly higher than that in control systems(22.02 mg/kg). Both were below the maximum permissible concentration(50 mg/kg) for Cu in seafood for human consumption in China. Therefore, recirculating systems can be used for commercial on-growing of Litopenaeus vannamei without loss of shrimp quality, even in water polluted by 0.30 mg/L Cu. The mechanical filter is the main route for Cu removal.     

Analysis of fatty acid composition of sea cucumber Apostichopus japonicus using multivariate statistics

Fatty acids （FAs） provide energy and also can be used to trace trophic relationships among organisms. Sea cucumber Apostichopus japonicus goes into a state of aestivation during warm summer months. We examined fatty acid profiles in aestivated and non-aestivated A. japonicus using multivariate analyses （PERMANOVA, MDS, ANOSIM, and SIMPER）. The results indicate that the fatty acid profiles of aestivated and non-aestivated sea cucumbers differed significantly. The FAs that were produced by bacteria and brown kelp contributed the most to the differences in the fatty acid composition of aestivated and non- aestivated sea cucumbers. Aestivated sea cucumbers may synthesize FAs from heterotrophic bacteria during early aestivation, and long chain FAs such as eicosapentaenoic （EPA） and docosahexaenoic acid （DHA） that produced from intestinal degradation, are digested during deep aestivation. Specific changes in the fatty acid composition of A. japonicus during aestivation needs more detailed study in the future.     

条斑紫菜类囊体膜蛋白质组双向电泳研究方法

以蓝绿温和胶电泳为工具,首次在国内用于条斑紫菜(Porphyra yezoensis)类囊体膜色素蛋白质复合物的研究。结果显示:(1)利用非离子型去污剂十二烷基麦芽糖苷(DM)增溶条斑紫菜类囊体膜,DM/Chla(w/w)15︰1产生的效果较好,在BN-PAGE胶中可以分离到较多较清晰的条带。(2)选取蔗糖密度层50%条带制备得到的类囊体膜样品进行第一向BN-PAGE和第二向SDS-Urea-PAGE电泳实验。第一向电泳分离出4个蛋白复合物,对第二向电泳胶上的15个蛋白点切取做质谱鉴定,检测到PSⅡ47ku,PSⅡ44ku,cytochrome f,PSⅡD2,PSⅡD1等蛋白。本实验证实了温和胶电泳与SDS电泳结合对于条斑紫菜这种原始红藻的类囊体膜研究方面应用的可行性。     

荣成天鹅湖越冬大天鹅粪便的重金属水平

为对大天鹅(Cygnus cygnus)保护及湖区管理提供基础数据,作者于2011年11月~2012年3月研究了山东荣成天鹅湖越冬大天鹅食物来源及其粪便的重金属水平。结果表明:所选择的食物来源中,Zn、As和Cr在硬毛藻(Chaetomorpha linum)中含量最高,Cd在大叶藻(Zostera marina L.)叶片中含量最高,Pb在大叶藻根茎中含量最高,Cu在石莼(Ulva pertusa)中含量最高,Hg在小麦(Triticum aestivum)中含量最高;水生植物来源的粪便中Cd含量极显著高于陆地植物来源的粪便,陆地植物来源的粪便中Cr,Pb和Hg含量显著高于水生植物来源的粪便;摄食小麦苗可能造成大天鹅对Cd和Hg的积累。     

陕西地区垂直形变分析

利用中国陕西地区三期国家一等水准网的平差成果、两期二等水准网成果、两期陕西省高程控制网成果、两期全球导航卫星系统（global navigation satellite system, GNSS）大地控制网成果、陆态网络等工程连续运行基准站及流动站成果、地理国情监测成果,分析陕西地区最新垂直运动趋势。结果表明:GNSS垂直运动与水准垂直运动趋势整体一致;20世纪70年代至2018年,关中平原垂直运动呈下降趋势,关中平原周边山区及高原垂直运动呈上升趋势;陕北地区地壳垂直运动总体上呈现上升趋势,平均上升速度约为4 mm/a;关中平原总体呈下降趋势,下降最大速度为6 mm/a;陕南地区也呈上升趋势,平均上升速度约为3 mm/a;陕北、西安局部区域的不均匀地面沉降灾害严重。