The assemblage and abundance distribution of jellyfish in northern Beibu Gulf

根据“908“专项北部湾2006—2007年四个季节的调查数据,分析了北部湾北部(20°n以北海域)水母类的种类组成、数量分布、优势种和群集结构特征及其环境影响因子。该区共记录水母类4类125种,分别为水螅水母类99种、管水母类17种、钵水母类4种和栉水母5种;以沿岸暖水种为主,占本区水母总种数的61.6%,其次是大洋暖水种,占37.6%,沿岸暖温种仅占0.8%。种数季节变化呈单峰型,夏季83种,冬季56种,秋季和春季各49种,四季均以水螅水母类为主。周年丰度变化呈单峰型,夏季(943.0个/M3)>春季(572.4个/M3)>冬季(548.2个/M3)>秋季(427.6个/M3)。拟细浅室水母、双生水母、球型侧腕水母、四叶小舌水母、半口壮丽水母、两手筐水母、异摇篮水母、双小水母、单囊美螅水母、疣真囊水母、半球美螅水母、六幅和平水母、八囊摇篮水母、刺胞真囊水母、黑球真唇水母、端粗范式水母和细颈和平水母共17种全年出现,为四季种;其中,前7种为四季优势种,优势度(y)分别为0.25、0.19、0.09、0.08、0.05、0.03和0.03,各季节的优势种演替模式不尽相同。依据水母种类和数量分布情况,北部湾北部水母类可划分2个群集:栖息在受沿岸流影响的20 M以浅的低盐群集,代表种有拟细浅室水母和双生水母等;栖息在受外海水影响的20 M以深的高盐群集,代表种有四叶小舌水母、半口壮丽水母和两手筐水母等。海流与水团的消长是影响水母类群集结构和水平分布格局的重要影响因素。The assemblage structure and abundance distribution of jellyfish were studied based on the samples of Beibu Gulf during 4 seasons in 2006—2007.The environmental factors that probably affected the number of species,abundance and assemblage structure were analyzed.The study showed that a total of 125 jellyfish species were identified,which belongs to4 assembleges,they were Hydromedusae,Siphonophora,Scyphomedusae and Ctenophore.Hydromedusae was the dominant assemblege,accounted for 79.2% of the total species.The species number of jellyfish varied seasonally,there was 83 in summer,which was the highest among 4 seasons,followed by winter,autumn and spring,the species number were 56,49 and 49.The 20 meters deep of water could be considered as the boundary according to the horizontal distribution of jellyfish species,the species number of the above was more than the under.There were three ecological groups of the jellyfish,the neritic warm-water group such as Lensia subtiloides,Diphyes chamissonis and Pleurobrachia globosa was the dominant group,accounted for 61.6% of total species, followed by the high-temperature oceanic group, occupied 37.6%, Liriope tetraphylla,Aglaura hemistoma and Solmundella bitentaculata were belonged to this group,and there was only one neritic low-temperature specie identified,that was Ocyropsis crystallina.The abundance of jellyfish varied seasonally,was highestin summer,followed by spring,winter and autumn.The abundance in the northwest of the studied area was higher,and the northern of Weizhou Island was lower,basiclly less than 10.0 ind / m3.There were 17 seasonal species which appeared the whole year,7 of them were dominant species,Lensia subtiloides,Diphyes chamissonis,Pleurobrachia globosa and Liriope tetraphylla were the most important.Lensia subtiloides got the largest abundance in summer,made contributions to 40.4%of the sum.Diphyes chamissonis' abundance was large in spring and winter,occounted for 36.3% and 32.6% of the sum in each season.The abundance of Liriope tetraphylla in autumn occupied 36.7% of the sum,was far more than the other three seasons.Pleurobrachia globosa' abundance in 4 seasons changed not much compared to the 3 mentioned species,was largest in summer,occupied 12.2% of the sum.The assemblage of jellyfish in northern Beibu Gulf was analyzed based on the effect of 10 factors,they were deeper( D,m),surface temperature( Ts,℃),middle temperature( Tm,℃),bottom temperature( Tb,℃),surface salinity( Ss),middle salinity( Sm),bottom salinity( Sb),surface chlorophll a( Chas,mg / m3),middle chlorophll a( Cham,mg/m3) and bottom chlorophll a( Chab,mg/m3).Though the results showed details difference in 4 seasons,it could be divided into two groups,the low-salinity group( lower than 20 m) and highsalinity group( deeper than 20 m) formed northern Beibu Gulf jellyfish assemblage structure.The low-salinity group was mainly affected by the coastal current from Guangxi to Vietnam,this group had two types depended on temperature,they were the neritic low-temperature type and the neritic warm-water type.The high-salinity group was mainly affected by the seawater.The environmental factors varied during four seasons.Currents and water masses were the main factors on jellyfish assemblage and abundance distribution.我国近海海洋综合调查与评价专项(908-01-ST09); 海洋公益项目“东南沿海半封闭海湾生态系统对人类活动干扰的响应评价、生态重构技术及示范”(201005012); 国家自然科学基金(41006078

Ecosystem structure and function in northern Beibu Gulf: zooplankton spatial niche and its differentiation

根据2006—2007年北部湾北部海域4个航次调查资料,采用k-优势度曲线法对浮游动物种(类)群进行排序分析,运用lEVInS公式和PIAnkA指数分析了主要优势种(类)群的生态位宽度值和生态位重叠程度,并通过除趋势典范对应分析(dCCA)研究生态位分化状况。结果表明,该海区浮游动物优势种(类)群按生态位宽度值可划分为广生态位、中生态位和窄生态位三大类型。其中,广生态位的种(类)群如肥胖软箭虫、亚强次真哲水蚤、长尾类幼体等具有较强的生态适应性,生活范围较广;窄生态位的种(类)群,对环境的适应性较差,对海流和水团等环境因素的变化具有指示意义。生态位宽度能够反映种(类)群丰度季节变化,但不能反映具体丰度大小。北部湾北部全年主要优势种(类)群的生态位宽度值介于0.08—0.77之间,并且各优势种(类)群的生态位宽度差异较大,种对间生态位重叠值介于0.02—0.89之间,平均生态位重叠指数为0.45,种(类)群之间利用资源环境的互补性较强,这与海域内生境多样化并且各优势种对环境适应能力的差异存在一定联系。dCCA分析表明,影响浮游动物分布的主要因子是水深、温度和盐度,其次是叶绿素A和溶解氧。The concept of ecological niche had remained as one of the core ideas in ecological research for almost a century,which was closely linked with interspecific competition,resource utilization had played an important role in the study of community composition and function,of the relationships among species,biodiversity,community succession and population evolution.Based on four seasonal investigations( Spring 2007,Summer 2006,Autumn 2007 and Winter 2006) in northern Beibu Gulf from 2006 to 2007,the niche breadth,niche overlap,spatial differentiation and environment effects on the abundance and spatial distribution of zooplankton were studied with qualitative and quantitative methods.The cumulative top 80% of zooplankton dominant populations were selected by the K-dominant curve method,then the niche breadths and their overlaps of zooplankton were measured using the formulas proposed by Levins Niche Breadth index and the Pianka Niche Overlap index,and the spatial niche differentiation was studied by using Detrended Canonical Correspondence Analysis( DCCA) method.The results showed that the zooplankton dominant species in northern Beibu Gulf were classified in to three groups,i e.,wide niche breadth groups( Bi= 0.60—0.77),middle niche breadth groups( Bi= 0.30—0.60),narrow niche breadth groups( Bi= 0.08—0.30) based on the niche breadth value.The niche breadths of zooplankton such as Sagitta enflata,Subeucalanus subcrassus and Macrura larvae were wider,which was related with their own characteristics and the capability of adapting environment,while the species whose niche breadths were narrower such as Doliolum denticulatum and Dolioletta gegenbauri will be considered as an indicative significance for ocean currents and water masses.Niche breadth could reflect the zooplankton abundance with the seasonal dynamic changes,and also could objectively reflect the species in the habitat in which the distributions of degree but it could not reflect the Accurate zooplankton abundance.The niche breadth values of dominance zooplankton species ranged between 0.08 and 0.77 in the whole year and The niche breadth difference among the dominant populations was great; The niche overlap values of dominance zooplankton species ranged between 0.02 and 0.89 in the whole year and the average niche overlap index was 0.45,there was strong complementarity in terms of the utility of resource among zooplankton populations,which had certain relationship with northern Beibu Gulf habitat diversification and the strong complementarity in terms of the utility of resource among zooplankton populations.The Detrended Canonical Correspondence Analysis result showed that depth,temperature and salinity had more important influence on the species spatial distribution than Chlorophyll a and dissolved oxygen.海湾公益项目(201005012); 我国近海海洋综合调查与评价专项(908-01-ST09

An ecological study on zooplankton in the northern Beibu Gulf V: the effects of microzooplankton grazing on phytoplankton in summer

2011年8月份于北部湾北部海域5个观测站位获得的分层水样,分析了表层叶绿素A含量和表层微型浮游动物丰度以及类群组成;同时于现场采用稀释培养法研究了该海域浮游植物生长率(μ)和微型浮游动物的摄食率(g)。分析和测定结果表明:调查海区的微型浮游动物丰度400—1167个/l,类群组成以无壳纤毛虫为主;浮游植物的生长率为-1.50—1.13 d-1,微型浮游动物摄食率为0.33—1.08 d-1;推算微型浮游动物对浮游植物现存量以及初级生产力的摄食压力分别为28.1%—66.0%和-7.4%—438.4%。相对于中国其他海区,8月份北部湾北部海域微型浮游动物摄食速率处于中等水平。调查期间,广西沿海高生产力海区,浮游植物生长率大于微型浮游动物动物的摄食率,浮游植物生物量处于积累期;涠洲岛以南海域,浮游植物生产力较低,微型浮游动物摄食作用是控制浮游植物生长的重要因素。In August 2011,we quantified the impact of microzooplankton grazing on phytoplankton production in the surface waters of the northern Beibu Gulf,Vietnam.Shipboard dilution incubation experiments were carried out at five stations to calculate phytoplankton specific growth rates and the specific rates of grazing losses to microzooplankton.Dilution experiments using chlorophyll a( Chl a) as a tracer were used to estimate daily rates in two size fractions; image-analyzed microscopy provided quantitative estimates of microzooplankton standing stock( including ciliate and vertebrate larvae).PFW( particle-free water) was used to dilute seawater to five target dilutions of 0%,20%,40%,60%,and 80%.Microzooplankton grazing and phytoplankton growth rates were estimated by the linear regression of AGR( apparent growth rate) versus dilution factor.We estimated the grazing impact of microzooplankton on phytoplankton by calculating the percentage of phytoplankton standing stock and potential primary production ingested.Average total chlorophyll a concentration was( 0.67 ± 0.58) μg / L.Small-celled phytoplankton dominated this particular community.A notable characteristic of the phytoplankton community structure was that nano- and picoplankton made up a significant portion.Aloricate ciliates dominated the microzooplankton samples,in particular Strombidium,which accounted for 27.2% of total aloricate ciliate abundance.In addition,loricate ciliates and copepod nauplii were recorded.Microzooplankton densityvaried from 400 to 1167 ind / L.The horizontal distribution of microzooplankton was greater in nearshore than in offshore waters.Abundance did not differ significantly with chlorophyll a concentration in this study; however,there was a positive correlation between microzooplankton abundance and temperature.The phytoplankton growth rate( < 200 μm) ranged between-1.50 and 1.13 d-1,with the highest values being associated with nearshore waters.Meanwhile phytoplankton mortality due to microzooplankton grazing( 0.33—1.08 d-1) was highest at the same nearshore sites; however,growth rates were low at these sites.Consequently,microzooplankton consumed 28.1%—66.0% of chlorophyll a standing stocks and-8.1%—438.4% of the primary production per day.However,the grazing rate of microzooplankton on nanoplankton( 2— 20 μm) varied from 1.87 to 0.52 d-1,with an average of( 0.94±0.57) d-1.Given that the rates of grazing on phytoplankton of <200 μm were lower than those on nanoplankton,we conclude that microzooplankton prefer to graze on nanoplankton.There was a positive correlation between phytoplankton growth rate and grazing rate; in addition,significant differences between grazing rate and chlorophyll a were found.This suggests that microzooplankton grazing activity is the main factor regulating the community structure and restraining the growth of phytoplankton.During the investigation period, microzooplankton grazing effectively controlled the growth of phytoplankton,consuming 176.2% of primary production on average.When grazing rates are far greater than phytoplankton growth rates,energy is transferred from lower to higher trophic levels more effectively.In the surface waters of the northern Beibu Gulf,microzooplankton largely control the growth of phytoplankton by grazing offshore rather than in nearshore waters where primary production is high.The growth and grazing rates combined promote planktonic ecosystem stability in this area.These results indicate that grazing by microzooplankton is a key process controlling the growth of phytoplankton in this area.海湾公益项目(201005012

福建绞股蓝皂苷的优化提取及其抗肝癌活性

绞股蓝素有"南方人参"美誉,含有与人参皂苷相同骨架达玛烷型结构的三萜皂苷。通过不同体积分数乙醇溶液优化提取绞股蓝皂苷,测定其抗癌活性,为后续活性化合物的分离奠定基础。利用HPLC分析绞股蓝的皂苷成分并确定提取绞股蓝皂苷的乙醇体积分数,正交实验优化提取方法,进而MTT法测定提取的绞股蓝皂苷抗肝癌活性。HPLC分析确定用体积分数75%乙醇溶液提取绞股蓝总皂苷(GYP),体积分数45%乙醇提取极性绞股蓝皂苷(GYP1),体积分数90%乙醇提取弱极性绞股蓝皂苷(GYP2);正交实验结果表明在70℃水浴中以30质量的体积分数45%乙醇加热提取12 h为最佳条件提取GYP1,在60℃水浴中以30质量的体积分数90%乙醇加热提取6 h为最佳条件提取GYP2;利用MTT法测定GYP、GYP1和GYP2对肝癌细胞的抑制作用,GYP和GYP2对肝癌细胞SMCC7721具有抗癌活性,半抑制率IC50值分别为(165.83±14.12)μg/mL和(113.97±9.26)μg/mL,GYP1没有抗癌活性,表明绞股蓝抗癌药效成分主要是由弱极性绞股蓝皂苷发挥功效

Preparation of potassium diformate by methyl formate and potassium hydroxide

联系人：李清彪. 第一作者：詹国武（1986—），男，学士.[中文文摘]本研究采用甲酸甲酯、氢氧化钾、甲酸为原料，一步反应制备二甲酸钾。系统地考察了影响产品收率的主要因素，优化了工艺条件，结果表明，当n(MF)/n(KOH)=1.20，n(HCOOH)/n(KOH)=1.44，反应时间为30min，反应温度为55℃时，二甲酸钾产品收率可达 98.8%。产品经红外光谱分析及成分测定，符合质量标准。[英文文摘]In this study, methyl formate, potassium hydroxide and formic acid were used as raw materials for one-step synthesis of potassium diformate. The main factors affecting the quality and yield of product were investigated. The optimal conditions for reaction were: molar ratio of MF to KOH 1.20:1, molar ratio of HCOOH to KOH 1.44:1, reaction time 30 min and reaction temperature 55℃. The product met the quality standard of potassium diformate after infrared spectrum analysis and composition determination.厦门大学创新性实验计划资助项

The relationship between nutrients and phytoplankton community structure in northern Beibu Gulf

根据2011年4月和8月北部湾北部(北部湾20°n以北的海域)的调查数据,北部湾北部春夏两季共鉴定出浮游植物312种,隶属于4门78属,硅藻是主要优势类群。春季优势种为细弱海链藻(THAlASSIOSIrA SubTIlIS)、丹麦细柱藻(lEPTOCylIndruS dAnICuS)、奇异棍形藻(bACIllArIA PArAdOXA)和尖刺拟菱形藻(PSEudOnITzSCHIA PungEnS);夏季优势种仅为海链藻(THAlASSIOSIrA SP.)。浮游植物群落在春季可划分为2个子群落(SPr1和SPr2),在夏季可划分为3个子群落(SuM1、SuM2和SuM3)。该海域n/P比值一直处于高的水平,绝大部分的水域表现为磷限制,这可能是硅藻大量生长所造成的。春季SPr2群落优势种的柔弱角毛藻(CHAETOCErOS dEbIlIS)与除铵盐之外的营养盐具显著相关关系,奇异棍形藻与环境因子无相关关系。夏季SuM3群落优势种的奇异棍形藻与磷酸盐具显著相关关系。分析表明,琼州海峡过道水为北部湾北部输送了磷酸盐,而硅酸盐则主要由陆地径流输入。Phytoplankton community and nutrient concentration in the northern Beibu Gulf in April and August 2011 were investigated.In this research, 312 phytoplankton taxa were identified, which belonged to four phyla and 78 genera, with Bacillariophyta being the main group.The dominant species were Thalassiosira subtilis, Leptocylindrus danicus, Bacillaria paradoxa, and Pseudonitzschia pungens in spring, and Thalassiosira sp.in summer.Phytoplankton community in northern Beibu Gulf could be divided into two natural groups in spring(spr1 & spr2) and three in summer(sum1, sum2 & sum3).N/P ratio was in a relatively high level in the study area, and most of the waters were phosphorus limitated which resulted from diatom blossom.Chaetoceros debilis was the dominant species of group spr1 and had significant correlation with nutrient in spring, except for ammonium.Bacillaria paradoxa was the dominant species of group sum3 and had significant correlation with phosphate in summer, but, it was uncorrelated with any environmental factors as the dominant species of group spr2 in spring.Phosphate was transported to northern Beibu Gulf through the Qiongzhou Strait corridor water, and silicate was input by land runoff.海洋公益性行业科研专项项目(201005012

In-Situ FTIR Spectroscopic Studies of Electro Oxidation of Ethanol in Alkaline Media at a nm-Pt/GC Electrode

运用电化学循环伏安和原位FTIR反射光谱研究了碱性介质中乙醇在nm Pt/GC电极上的氧化。结果表明 ,主要产物是CH3 COO-,仅存在少量乙醛 ,未检测到CO谱峰。与酸性介质中乙醇氧化的双途径机理不同 ,碱性介质中乙醇的氧化未经过解离吸附的中间步骤。The electro oxidation of ethanol on a nm Pt/GC electrode in alkaline solutions was investigated by using cyclic Voltammetry and in situ FTIR spectroscopy.The results demonstrated that the main product of ethanol oxidation was CH 3COO -,only small quantity of CH 3CHO was determined simultaneously.In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media,the oxidation of ethanol in alkaline media was revealed via the intermediate process of dissociative adsorption.国家自然科学基金项目!(2 98330 60 );; 国家教育部科学技术重点研究项目!(991 77)资

In-situ FTIR spectroscopic studies of electro oxidation of ethanol in alkaline media at a nm-Pt/GC electrode

The electro-oxidation of ethanol on a nm-Pt/GC electrode in alkaline solutions was investigated by using cyclic Voltammetry and in-situ FTIR spectroscopy. The results demonstrated that the main product of ethanol oxidation was CH3 COO-, only small quantity of CH3 CHO was determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media was revealed via the intermediate process of dissociative adsorption

Responses of seedling emergence and growth of four key speceis to sand burial and watering regime in Mu Us sandy land

飞播是毛乌素沙地植被恢复与重建的重要手段。但此项技术仍存在一些问题，如飞播后成苗率较低等。柠条(Caragana korshinskii)、羊柴(Hedysarum laeve)、籽蒿(Artimisia sphaerocephala)与油蒿(Artimisia ordosica)是毛乌素沙地广泛分布的物种，也是飞播的主要物种。本文以飞播植被恢复技术为突破口，研究沙埋和土壤水分对种子萌发，幼苗出土和生长的影响，探讨幼苗出土和生长对沙生环境的适应对策。对采用合适的物种进行生态工程建设，提高生态工程的稳定性及可持续性具有重要意义。同时，本项研究有助于加深半干旱区植物对沙生环境适应机理的认识。 以上述4种植物为研究对象，设定7个沙埋深度和9个水分梯度，研究种子萌发和幼苗出土对沙埋和单次供水的响应。设定7个沙埋深度，选择3个沙丘部位，研究沙丘不同部位对植物种子萌发的影响。设定6个沙埋深度、4个水分梯度，研究两种蒿属植物幼苗生长对不同沙埋和供水的响应。得出如下主要结论： (1) 对于种子质量相对较大的柠条和羊柴而言，在一次性10-20 mm供水量条件下，幼苗主要在0.5-2 cm埋藏深度之间出土，但在埋藏深度为5 cm时这两个物种仍有少部分幼苗能够出土；对于种子质量相对较轻的油蒿和籽蒿而言，在一次性10-20 mm供水量时，幼苗主要在0.5 cm埋藏深度出土，油蒿和籽蒿幼苗在埋藏深度为1.5和2 cm时不能出苗。沙埋深度为0.5 cm时，4个物种出苗率较高、出苗时间较短、出苗速率较快。 (2) 实验期内(30天)在一次性供水量分别为5、7.5和7.5mm时，柠条、羊柴和油蒿出土幼苗全部死亡；在一次性供水量高于15-20 mm时，出土幼苗死亡率低于50%；籽蒿在供水量高于10 mm时出土幼苗死亡率低于50%；随供水量的增加4个物种出土幼苗的死亡率降低。 (3) 结合毛乌素沙地降雨特点与本文实验结果，0.5 cm的沙埋及7.5 mm以上的单次降雨量是上述4种植物自然条件下出苗较高的重要条件。 (4) 在沙丘顶部，2-7 cm沙埋深度之内各个物种不同沙埋深度的种子萌发率差异不显著。沙丘背风坡中部和底部，4个物种在沙埋深度为1 cm时的种子萌发率均显著高于5、7 cm时的萌发率。当沙埋深度为1-5 cm时，柠条和羊柴种子在坡面不同位置的萌发率均高于20%，且显著高于7 cm沙埋深度时的萌发率。在背风坡底部时，柠条、羊柴、油蒿和籽蒿的种子萌发率达到最大值，分别为45.2±3.27%、48.4±5.21%、20.8±4.63%和22.4±4.83%。4个物种的种子萌发率从沙丘顶部到背风坡中部到底部呈递增趋势，表明背风坡中部和底部的环境条件要比顶部更适合种子萌 发。 (5) 部分沙埋促进幼苗生长。2种蒿属植物幼苗在沙埋深度为0.25、0.5 H时比在0、0.75 H时具有更高的生物量、叶面积、相对生长速率（RGR）和净同化速率（NAR）。在75 mm/月供水量时，油蒿幼苗具有较高的生物量和叶面积，但当供水量达到100 mm/月时其幼苗生长受到抑制。油蒿幼苗在遭遇较深（0.5、0.75 H）沙埋时的根冠比要显著高于未沙埋幼苗的根冠比；籽蒿幼苗根冠比在不同沙埋条件下没有显著变化。籽蒿幼苗在50 mm供水量时具有较高的RGR。油蒿幼苗在75 mm供水量时具有较高的RGR和NAR