增强的UV-B辐射对陆地生态系统的影响

本文根据最近的文献,回顾了ＵＶ－ Ｂ 辐射对陆地生态系统的影响。ＵＶ－ Ｂ 辐射影响植物物候、形态和次生代谢,从而改变生态系统的物种结构、竞争性平衡、食物链、植物病原体、物质循环、真菌移殖与叶片分解。植物物候、形态和次生代谢的变化是ＵＶ－ Ｂ 辐射调控影响生态系统的重要途径,具有重要的生态学意义。虽然我们已经适当了解了ＵＶ－ Ｂ 辐射对植物作用的机理,但由于温室内植物个体水平的短期响应与野外条件下生态系统的长期响应具有明显的差异,到目前为止还不能预测ＵＶ－ Ｂ辐射影响生态系统的精确后果,有时甚至连变化方向也不能预测。因此,必须强调生态系统对ＵＶ－ Ｂ 辐射长期响应的野外研究的重要性。     

ZCMR法从废物中制取活性炭及在含铬废水处理中应用

采用微波照射－ 氯化锌（ZCMR） 法从废物中制取锯末活性炭及烤胶废料活性炭,用所得的两种活性炭处理含铬废水,结果表明,ZCMR法制取的废物活性炭对电镀废水中铬的吸附容量是市售一级粉末活性炭的1.72 ～1.8 倍, 过滤速度是市售活性炭的1.6 ～1.7 倍, 极限吸附量达21.5 ～22.5mg/g．     

Behavioral diversification in a young species flock of pupfish (<Emphasis Type="Italic">Cyprionodon</Emphasis> spp.): shoaling and aggressive behavior

Increasing empirical and theoretical evidence supports the idea that sympatric speciation is operating, for example, in species flocks comprising several closely related fish species within one lake. Divergent natural selection (promoting spatial and food niche partitioning) and sexual selection (assortative mating) have been identified as key selection factors in intralacustric adaptive radiations. However, the evolution of social behaviors accompanying such adaptive radiations is less well understood. Using a phylogenetically young species flock of pupfish (Cyprinodon spp.) as a model, we examined differences among six sympatric species and compared their shoaling, aggressive, and territorial behaviors with that of a sister species (C. artifrons). Despite an estimated age of the species flock of less than 8,000 years, pronounced behavioral differentiation was found. C. simus, the smallest species in the flock, shoaled more than the other species and was less aggressive and less territorial than C. beltrani. F₁-hybrids between C. simus males and C. beltrani females showed an intermediate expression of shoaling and aggressive behavior. Niche partitioning among the members of this species flock appears to be accompanied by rapid divergent evolution of social behaviors. We discuss the potential role of phenotypic plasticity and within-species variation of social behaviors for such rapid behavioral diversifications in sympatric speciation processes.     

紫外辐射对灯盏花附生、内生细菌数量的影响及机理

采用大田研究方法,模拟5.0kJ·m~(-2)紫外辐射(UV-B,280～315nm)增强对灯盏花Erigeronbreviscapus附生、内生细菌数量、优势种群以及类黄酮、游离氨基酸、可溶性蛋白、淀粉和可溶性糖含量的影响.UV-B辐射极显著减少灯盏花苗期叶和花期根与叶附生细菌数量(p<0.01),显著减少灯盏花果熟期根与叶附生细菌数量(p<0.05).极显著减少灯盏花苗期根与叶和花期叶与茎及果熟期茎内生细菌的数量,果熟期根内生细菌数量显著增加.灯盏花附生细菌优势种群为芽孢杆菌Bacillus和欧文氏菌Erwinia,内生细菌优势种群为芽孢杆菌;UV-B辐射可导致灯盏花附生和内生细菌优势种群数目减少.UV-B辐射还会使灯盏花生理指标发生变化,直接导致灯盏花附生细菌数量的减少,可溶性糖、游离氨基酸和可溶性蛋白含量与附生细菌数量呈显著正相关(p<0.05).UV-B辐射增加灯盏花各部位类黄酮含量,间接影响灯盏花内生细菌数量,根类黄酮含量与内生细菌数量呈极显著正相关(p<0.01).     

矿山开采沉陷可视化系统设计开发及岩移参数求取

依据矿山开采沉陷相关理论,以概率积分法数学模型为基础、运用基于实测数据求参原理与方法,结合相关软件设计开发了矿山开采沉陷可视化系统。为研究矿区地表移动变形分布及岩移参数求取提供了技术支持。结合系统应用实例,利用地表观测数据拟合求参,对该矿其他工作面及类似地质条件矿区开采沉陷预计提供借鉴作用。     

障碍物对天然气喷射火影响的数值模拟研究

为研究障碍物控制天然气喷射火对周围设施危害的有效性,基于流体力学基本原理与湍流模型,采用FDS模拟软件,分别研究高度为10 m的障碍物宽度和障碍物与泄漏孔间距对喷射火的影响。研究得出:障碍物对喷射火阻挡效果明显,减缓了火焰在速度方向的传播;障碍物越宽,控制火焰向前传播的效果越好,障碍物后方受火焰高温和热辐射危害越小,但随着宽度的增加,后方温度和热辐射下降率减小,障碍物宽3 m时,对火焰控制效果最好;随着障碍物与泄漏孔间距增加,障碍物后方热辐射先增加后减小,间距为5 m时,障碍物对火焰的控制效果最好,此时喷射火下游受保护的区域最宽。研究结果可为储气罐发生泄漏火灾事故处置及应急设施设计提供参考。     

Trace elements in fish and oysters from Sepetiba Bay (Rio de Janeiro – Brazil) determined by total reflection X-ray fluorescence using synchrotron radiation

Trace elements were determined in fish and oysters from Sepetiba Bay, Brazil, by total reflection Xray fluorescence using synchrotron radiation (SRTXRF). Cr, Mn, Fe, Ni, Cu, Zn and Se were determined in fish muscles and organs and in oyster soft tissue. SRTXRF was shown to be a good tool for the analysis of trace elements from biological tissue samples. Overall, the levels of the analysed metals were higher in oysters than in the fish samples. Metals were not uniformly distributed throughout the body of the analysed fish. The detected concentrations of Cr, Zn and Se were very high in some samples, surpassing the maximum limits established by Brazilian legislation.     

Effects of cucl2 on UV‐mutagenesis and on DNA damage in a restriction fragment of E. Coli gpt∗

CuCl₂ does not cause Trp⁺ reversion in E. coli WP2. However, when the bacteria are exposed to CuCl₂ and UV‐irradiated, a greater than 3‐fold enhancement of mutagenesis (compared to UV alone) is seen at 30 μMCuCl₂, and significant enhancement is seen even at 3 μM. The mechanism for this comutagenic effect was studied using a restriction fragment of the E. coli gpt gene. Whereas UV or CuCl₂ alone caused few strand breaks, UV + CuCl₂ induced breaks at every site. This reaction was blocked by KI, a free radical scavenger. While UV alone induced alkali‐labile sites, UV+ CuCl₂ induced many more such sites and altered the sequence specificity. We suggest that at least some of the comutagenic effect might be due to hydroxyl radical formed via a Fenton reaction.     

水体冻结过程中卤乙酸前体物在水-冰体系中的分配研究

通过室内模拟试验,研究了水体冻结过程中,水体中溶解性有机物(DOM)和卤乙酸前体物在水-冰体系中的分配规律.按照DOM在XAD树脂上的吸附特性将其分为5个部分:疏水性有机酸(HPO-A),疏水性中性有机物(HPO-N),过渡亲水性有机酸(TPI-A),过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).结果表明:在水体冻结过程中,5种DOM组分在水相中的DOC浓度均随冷冻时间的增长而增加,呈现冷冻浓缩效应.与溶解性有机碳(DOC)所表征的整体有机物相比,5种DOM组分中的卤乙酸(HAAs)前体物更倾向于停留在水相中浓缩.在5种DOM组分中,HPI是主要的HAAs前体物.5种DOM组分在未冻结水中的UV-254与HAAFP均表现出一定相关性,其中HPO-A, TPI-A和HPI的UV-254与HAAFP达到极显著水平.然而在融冰水中,这5种DOM组分的UV-254与HAAFP的相关性均不显著.     

上海市小学生交通行为观测与特征分析

为了有针对性地开展小学生交通安全教育,采用行为观测方法研究了上海市小学生的交通行为特征。采用视频观测小学生过街,对行为特征进行编码,利用数理统计分析方法研究行为特征规律。研究发现整体上小学生安全过街行为表现很差,在路边正确位置等待和正确左右观看两方面表现尤为欠缺。研究特别对小学生过街行人组合(一人、结伴、家长陪同)、路口过街方式(一次过街2、次过街)和性别对其交通行为的影响进行了分析,发现过街行人组合显著影响等待位置、是否闯红灯、是否正确左右观看,路口过街方式显著影响等待位置、是否闯红灯、是否正确左右观看、有无不良交通行为,小学生的性别对过街时的交通行为无显著影响。因此对小学生进行交通安全教育是十分必要的,需要针对小学生交通行为特征开展有针对性的安全教育。