褶皱臂尾轮虫(Branchionus plicatilis)响应四溴联苯醚(BDE-47)胁迫的能量代谢变化研究

多溴联苯醚(PBDEs)作为一种典型的持久性有机污染物,对海洋生物和生态系统的可持续性构成严重威胁。以2,2’,4,4’-四溴联苯醚(BDE-47)作为胁迫因子,以褶皱臂尾轮虫(Branchionus plicatilis)作为受试生物,基于代谢组学技术探讨褶皱臂尾轮虫应对BDE-47胁迫时的能量代谢变化。24 h胁迫实验的结果表明:褶皱臂尾轮虫的滤水率(F)和摄食率(G)显著降低,抑制了其对能源物质的获取;褶皱臂尾轮虫α-淀粉酶、脂肪酶、胰蛋白酶活性均受到抑制,降低了其对能源物质的消化效率;褶皱臂尾轮虫的总腺苷酸含量(TAP)随着BDE-47胁迫浓度的增加而不断下降,其能量状态发生了不利变化;褶皱臂尾轮虫的细胞能量分配(CEA)降低,是能量储备(Ea)减少和能量消耗(Ec)增加共同作用的结果。代谢组学分析表明褶皱臂尾轮虫的氨基酸代谢、脂质代谢和糖代谢产生了显著变化,发现了与氨基酸代谢、脂质代谢和糖代谢相关的26种差异代谢物和20条代谢通路,氨基酸、脂肪酸以及果糖水平显著下调,溶血磷脂酰胆碱(lysoPC)和磷酸乙醇胺(PE)显著上调。以上结果表明,BDE-47急性毒性胁迫影响了褶皱臂...     

中国民用燃煤CH4释放的初步研究—以贵州省为例

对中国贵州省不同类型的民用燃煤的ＣＨ４释放量进行了实际监测,得出了各自的ＣＨ４释放因子,并借此探讨了民用燃煤过程的ＣＨ４释放规律。根据民用燃煤情况,估算出１９９０年一年内中国和贵州省民用燃煤的ＣＨ４释放量分别为１．４３Ｔｇ和０．０６Ｔｇ。     

Identification and characterization of a DnaJ gene from red alga <Emphasis Type="Italic">Pyropia yezoensis</Emphasis> (Bangiales,Rhodophyta)

Members of the DnaJ family are proteins that play a pivotal role in various cellular processes, such as protein folding, protein transport and cellular responses to stress. In the present study, we identified and characterized the full-length DnaJ cDNA sequence from expressed sequence tags of Pyropia yezoensis (PyDnaJ) via rapid identification of cDNA ends. This cDNA encoded a protein of 429 amino acids, which shared high sequence similarity with other identified DnaJ proteins, such as a heat shock protein 40/DnaJ from Pyropia haitanensis. The relative mRNA expression level of PyDnaJ was investigated using real-time PCR to determine its specific expression during the algal life cycle and during desiccation. The relative mRNA expression level in sporophytes was higher than that in gametophytes and significantly increased during the whole desiccation process. These results indicate that PyDnaJ is an authentic member of the DnaJ family in plants and red algae and might play a pivotal role in mitigating damage to P. yezoensis during desiccation.     

Interspecific competition and allelopathic interaction between <Emphasis Type="Italic">Karenia mikimotoi</Emphasis> and <Emphasis Type="Italic">Dunaliella salina</Emphasis> in laboratory culture

Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on diff erent temperature (15°C, 20°C, and 25°C) and lighting (40, 80, and 160 μmol/(m²·s)) conditions. The growth of D. salina in bi-algae culture (1:1 size/density) was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-tocell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. mikimotoi were markedly influenced by both temperature (P =0.013) and irradiance (P =0.003), resulting in diff erent growth characteristics of D. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.     

陇东白垩系盆地地下水水化学特征及分布规律

陇东白垩系盆地地处甘肃省陇东黄土高原地区.盆地内蕴藏有丰富的地下水资源,然在特定的地理环境及地质构造背景条件下,地下水化学特征变化复杂.对陇东白垩系盆地保安群地下水的水化学特征进行分析研究,得出:盆地内划分的白垩系三层含水岩组水化学特征及分布规律各具特征,整个盆地内地下水水化学场存在一个大致以马莲河为中心、由周边向中部的水平分带,TDS从盆地东西两侧向中心由低渐高;而垂直分带规律则根据水动力特征,分为水交替强烈带、水交替缓慢带和水交替极缓慢带,各带的水化学特征也不相同.     

黄渚镇赵河泥石流沟特征及治理工程探析

黄渚镇位于地质灾害高频发地区——陇南山地的北部。泥石流灾害是威胁黄渚镇及厂坝安全的最主要因素。2010年8月12日,黄渚镇一带遭遇百年不遇的暴雨,形成暴洪泥石流灾害,给当地群众及厂坝铅锌矿作业区造成重大灾害与损失。本文对造成损失最严重的赵河泥石流沟特征进行分析,并提出了治理工程措施,以期为今后该地区相似灾害防治提供参考。     

纳米氧化铝改性粘土试验研究

将具有优异性能纳米Al2O3(简称NA)作为外掺剂应用于粘土改性研究,NA以0%、1%、2%、3%、4%和6%的掺量分别掺入到含水量为10%、16%、22%粘土试样中,共配制了18组试样,对试样进行室内无侧限抗压强度试验。结果表明,试样强度随NA掺量的增大而增大,随土样含水量的增大而减小,4%NA掺量的试样能显著提高粘土的强度和稳定性。分析表明,NA的胶结填充作用和孔隙的填充以及其本身的表面吸水作用对加固效果有重要影响。     

渤海湾潮间带表层沉积物重金属潜在风险评价

分析了渤海湾潮间带表层沉积物重金属(Cu,Pb,Zn,Cd和Cr)含量及分布特征,并采用潜在生态危害指数法对渤海湾潮间带表层沉积物进行评价.结果表明,此5种元素含量均未超出海洋沉积物质量标准一类标准.Cu、Pb、Cd、Cr分布特征基本相似,高值出现在站位4和站位11,Zn的分布特征不同,质量分数变化很大,存在明显的高值...     

电子商务网站成本及收入分析

在网站建设与运行过程中所发生的资金耗费即是网站成本。在这里，着重讨论电子商务网站成本的分类，各类成本的构成、特征，网络收入的来源，进而提出了判别能否持续经营电子商务网站的条件。     

日本福岛核事故对我国辐射环境影响的监测与分析

2011年3月11日,日本东北海域发生9.0级地震并引发海啸,受此影响日本福岛第一核电站发生核泄漏事故。3月26日,我国黑龙江监测站首次在空气样品中监测到来自日本福岛的放射性元素I 131,监测持续近一个月。基于我国31个省(区、市)的大气放射性浓度监测记录,综合利用Hybrid Single Particle Lagrangian Integrated Trajectory Model(HYSPLIT)模式的扩散轨迹模拟技术和大气环流形势,分析讨论了日本福岛核事故泄漏期间我国大气放射性环境水平。整个监测期间,我国I 131的浓度最大值位于吉林省8.01 mBq·m-3,发生在4月7日左右,与在此期间我国东部地区的持续东风紧密相关;此外,华北、东北和西北的整体I 131相对浓度较高。Cs 137和Cs 134的最大值均发生在新疆地区,浓度分别为1.55和1.42 mBq·m3;与此同时,其全国平均浓度呈双峰型变化,峰值分别发生在4月4日和9日左右,其结果反映了大气环流和排放速率变化的综合影响。我国西北和华北的监测浓度值较高。此外,还就Cs 137/I 131和Cs 134/Cs 137的比值与其他国家的监测结果进行了对比分析,结果表明,我国监测到的Cs 137/I 131比值在0.04～0.9之间,其值变化范围较大,且整体呈上升趋势,与此同时,整个监测期间Cs 134/Cs 137比值在1附近摆动。