马氏珠母贝选育子一代生长特性研究

通过选择培育获得马氏珠母贝Pinctada martensii大亚湾养殖群体选育子一代(DDS),以大亚湾养殖群体为对照(DDC),在相同条件下进行养殖,对其生长性状进行了约1年的跟踪测量,运用t检验对2个组别主要性状进行了比较。分析表明,经过一代的选育,DDS在壳长、高、宽和总重上均大于DDC,存活率提高9.18%,除壳长在2个时期(2003年12月,2004年2月)差异不显著外(p>0.05),DDC/DDS2个组别其他性状在7个生长时期均具有显著差异(p<0.05)。该研究为进一步通过选择育种培育马氏珠母贝优良品种奠定了基础。     

NaCl型油田水中I^-的离子选择电极法测定

采用了NaCl溶液为离子强度调节剂(TISAB),离子选择电极法测定NaCl型油田水中I-离子的含量,并对该方法进行了测定条件实验的研究。标准曲线在7.94×10-6～1.00 mol/L范围内呈良好的线形关系,相关系数R2=0.999 5,平均回收率为98.9%,RSD(n=6)=1.0%,实验结果表明,该方法测定NaCl型油田水中的I-简便、快速、准确。     

In-situ studies of microzooplankton grazing pressure on phytoplankton in Jiaozhou Bay, China

Preliminary studies on microzooplankton grazing were conducted with dilution method in Jiaozhou Bay from summer 1998 to spring 1999. Four experiments were carried out at St. 5 located at the center of Jiaozhou Bay. Chlorophyll a concentrations were consistently dominated by netphytoplankton (net-, >20μm), except during the autumn 1998 cruise, when they were dominated by nanophytoplankton(nano-, 2–20μm). The contribution of picophytoplankton (pico-, <2μm) to total chlorophyll a concentrations (<200μm) varied considerably between cruises. Instantaneous growth coefficients(u) of phytoplankton varied from 0.098 to 1.947d⁻¹, with mean value of 0.902d⁻¹. Instantaneous coefficients(g) of microzooplankton grazing on phytoplankton ranged from 0.066 to 0.567d⁻¹, mean value of 0.265d⁻¹, which was equivalent to daily lose of 21.9% of the initial standing stock and 58.1% of the daily potential production. Project No KZCX3-SW-214 supported by Chinese Academy of Sciences.     

锡林郭勒草原生态恢复工程效果的评价

针对锡林郭勒草原的严重退化, 近年来启动了草原生态恢复工程, 但工程实施的效果由于范围广、时间短而很难予评价。利用锡林郭勒草原地区1999~2004 年的SPOT-VGT 10 天最大值合成NDVI 时间序列数据, 在求得各年NDVI 年最大值(NDVImax) 的基础上, 通过搜寻各像元邻域内NDVImax 的最大值以及与之相应的气候因子, 建立起了像元尺度上的气候-植被生长基准响应模型, 并以此为依据运用相对残差趋势法识别出了处于恢复阶段的草原区域。 最后, 将遥感监测结果与羊单位统计资料进行对比分析, 结果发现, 在县级行政区域尺度上的平均恢复趋势与基于羊单位和NPP 构建的放牧压力趋势具有较好的反比例关系, 初步证明了该方法在时间序列较短情况下的有效性。     

古尔班通古特沙漠生物结皮小尺度分异的环境特征

古尔班通古特沙漠广泛存在的生物结皮,对地貌部位有极强的选择性分布,其实质是生物对环境条件综合适应的一种生态表现。2002年3~11月在个体沙丘表面初步开展了生物结皮类型小尺度环境分异规律研究。结果表明:苔藓结皮、地衣结皮和藻类结皮依次分布于垄间、沙垄两坡中部和坡上部,从垄间往垄顶,生物结皮盖度逐渐减小,厚度变薄,抗压性减弱。苔藓结皮分布区的物质组成以细沙和极细沙为主,春季表层土壤水分在5%以上,短命植物广泛发育,基质稳定;坡中部的地衣结皮分布区以细沙为主,春季表层土壤水分在4%左右,短命植物亦有广泛分布,地表受风沙活动影响较小;沙垄上部和顶部的藻类结皮分布区,是沙垄表面活动性最强和土壤水分最差的区域,物质组成以中沙为主,高等植物中白梭梭为优势种,可见藻结皮是三类结皮中最能适应恶劣环境的生物结皮类型。     

自然水体采集的生物膜上铁、锰氧化物的萃取分离

采用选择性萃取分离技术对自然水体采集的生物膜上铁、锰氧化物进行萃取分离研究,考察该技术的适用性。参考人工培养生物膜的萃取方法,分别用NH₂OH·HCl和Na₂S₂O₄为萃取剂选择性萃取生物膜上的锰氧化物和铁、锰氧化物。实验中分别依次只改变萃取剂浓度、萃取液酸度或萃取时间,保持其它两个因素不变,分别考察这三个因素对萃取效果的影响,从中选出对铁、锰氧化物萃取率高而对有机质影响小的条件为最佳条件。用选定的最佳条件对不同时间和地点采集的生物膜进行萃取,发现对目的组分的萃取率可达70.8%~94.6%,而对非目的组分的影响很小（3.3%~11.0%）,满足萃取分离的要求。这说明选择性萃取技术可以广泛应用于自然水体采集的生物膜上铁、锰氧化物的萃取分离。     

敦煌某地铁矿中磁性铁的化学物相分析

本文选用HAC—H_2O_2和HCl—NaHCO_3作为选择性溶剂,对敦煌某地铁矿中磁性铁的化学物相分析进行了研究,将磁性铁物相从传统1项细化为3项,测定了磁性铁相态中磁黄铁矿、假象赤铁矿、磁铁中铁的含量。使用国家标准物质GBW07272对方法进行了评价,分析结果与标准值或参考值吻合良好(RE为0.28%~4.75%,RSD为0.13%~5.59%)。方法简单、准确。     

盐酸及乙酸介质中的碳酸盐岩溶蚀表面特征及机理——以南堡凹陷为例

为了研究酸性条件下碳酸盐岩的溶蚀表面特征及机理,以南堡凹陷及周边凸起区10个典型碳酸盐岩样品为研究对象,进行乙酸和盐酸溶液的溶解实验,并通过扫描电镜观察样品的溶蚀特征。结果显示,岩石结构和矿物成分的选择性溶蚀,是碳酸盐岩溶蚀过程中的主要作用形式;方解石和白云石均存在特有的溶蚀现象,即"溶蚀晶锥"方解石和"蜂窝状"白云石,为晶体选择性溶蚀的产物;表生条件下,灰岩中少量白云石的加入能够增加方解石的溶解度,白云石的含量上限为13%,超过该界限,随白云石含量的增加,溶蚀作用减弱。     

Effect of Cu toxicity at different salinity on selective group of juvenile pompano Trachinotus ovatus

Effects of copper toxicity and salinity shock on selective group of juvenile pompano Trachinotus ovatus were investigated.The fish were exposed to different Cu2+ concentrations of 0(blank),0.02(C1),0.05(C2),0.10(C3),and 0.15 mg·L–1(C4)at a salinity of 10‰ or 40‰ for 96 h,with the salinity of 29‰ as the control.The results showed that the effects of the acute salinity stimulation to survival rates of pompano between control(29‰)and lower or higher salinity for 96 h were not significant(p0.05).However,the survival rates in each treatment were decreased with the increase of Cu2+ concentration.The dominant factor influencing body moisture of the fish was salinity,and there was no sign that body moisture was correlated with exposure to Cu2+.The gill lamellas in high level of Cu2+ concentration(C4 treatments)were abnormal under the salinity of 40‰ and extremely curly under the salinity of 10‰.Hemorrhage in gill was observed in the two C4 treatments.Under transmission electron microscope,pillar cells in gill lamellas appeared deformed and ruptured in some areas of the epithelia in the higher concentration of Cu2+,resulting in the death of the fish due to the destruction of gill tissue,elevation of the arithmetic mean distance from water to blood,the decrease of oxygen diffusion capacity,and other physiological functions.These findings indicate that the pompano might suffer much more pressure when encountered with Cu2+ pollution and low salinity.