云南稻核心种质苗期与孕穗期耐冷性特点及关系分析

以544份云南地方稻核心种质为材料,在昆明自然低温(苗期平均5.5～12.3℃,孕穗期平均17.8℃)冷害下,按籼粳、稻作区进行云南稻核心种质苗期耐冷性与孕穗期耐冷性的特点及关系研究.结果表明:(1)苗期耐冷性与孕穗期耐冷性密切相关,苗期耐冷性强的材料表现为孕穗期株高、剑叶长和宽、穗颈长、穗下节长、1～2节长、穗长较长、穗粒数较多,耐冷性较强.通过对苗期耐冷性的严格选择,可以间接获得孕穗期耐冷性较强的材料.(2)苗期和孕穗期耐冷性在籼粳间、稻作区间差异明显.籼粳间均表现为粳稻强于籼稻;稻作区间苗期耐冷性为滇中一季籼粳稻区和滇南单双季籼稻区最强,滇中一季籼粳稻区和滇西北高寒粳稻区孕穗期耐冷性较强,揭示了水稻苗期与穗期耐冷性的形成演化机制存在一致性和差异性.     

Characterization of Methylocystis strain JTA1 isolated from aged refuse and its tolerance to chloroform

To accelerate the efficiency of methane biodegradation in landfills,a Gram-negative,rod-shaped,non-motile,non-spore-forming bacterium,JTA1,which can utilize methane as well as acetate,was isolated from the Laogang MSW landfills,Shanghai,China.Strain JTA1 was a member of genus Methylocystis on the basis of 16S rRNA and pmoA gene sequence similarity.The maximum specific cell growth rates(μmax=0.042 hr-1,R2=0.995) was derived through Boltzmann simulation,and the apparent half-saturation constants(Km(app)=7.08mmol/L,R2=0.982) was calculated according to Michaelis-Menton hyperbolic model,indicating that Methylocystis strain JTA1 had higher-affinity potential for methane oxidation than other reported methanotrophs.By way of adding the strain JTA1 culture,the methane consumption of aged refuse reached 115mL,almost two times of control experiment.In addition,high tolerance of Methylocystis strain JTA1 to chloroform could facilitate the methane oxidation of aged refuse bio-covers.At the chloroform concentration of 50mg/L,the methane-oxidation rate of bio-cover reached 0.114mL/(day·g),much higher than the highest rate,0.0135mL/(day·g),of reported bio-covers.In conclusion,strain JTA1 opens up a new possibility for environmental biotechnology,such as soil or landfills bioremediation and wastewater decontamination.     

Mn/TiO2和Mn-Ce/TiO2低温脱硝催化剂的抗硫性研究

在低温选择性催化还原(SCR)反应条件下考察了烟气残余SO2对Mn/TiO2和Mn-Ce/TiO2催化剂选择性催化还原活性的影响,同时对SO2的影响机理进行了探讨.结果发现,Mn/TiO2催化剂在SO2反应气氛中失活很快,硫铵盐的沉积和活性组分的硫酸化是催化剂失活的重要原因;Ce的加入可以有效地抑制催化剂活性组分的硫酸化,同时还能降低硫酸盐在催化剂表面的稳定性,从而可以提高催化剂的抗硫性.     

同化和共代谢降解氯苯菌株的筛选与特性研究

基于污染场地,筛选了一株可降解氯苯（CB）的微生物,经鉴定该菌株属于粘质沙雷氏菌属（Serratia marcescans）,命名为Serratia marcescans TF-1.同化降解结果表明,该菌株能够在有氧的条件下以CB为唯一碳源和能源,菌体平均增长速率为0.0063~0.022g_cell/（mol_CB·h）,最大比生长速率（μ_max）为0.015~0.42h^-1,CB降解速率（V_CB）为1.35~4.47mol/（g_cell·h）,菌株对CB最高耐受浓度高于200mg/L.共代谢降解结果显示,TF-1可以琥珀酸钠和柠檬酸钠为底物共代谢降解CB;氯苯浓度（c_CB）<80mg/L时,μ_{max（柠檬酸钠）}（0.21~0.87h^-1）>μ_{max（琥珀酸钠）}（0.20~0.81h^-1）,V_{CB（柠檬酸钠）}（0.15~0.47mol/（g_cell·h））<V_{CB（琥珀酸钠）}（0.17~0.48mol/（g_cell·h））;c_CB>80mg/L时,μ_{max（柠檬酸钠）}（0.086~0.21h^-1）<μ_{max（琥珀酸钠）}（0.17~0.25h^-1）,V_{CB（柠檬酸钠）}（0.61~1.11mol/（g_cell·h））>V_{CB（琥珀酸钠）}（0.56~0.95mol/（g_cell·h））,表明共代谢降解过程中,CB浓度,底物种类是调控污染降解的重要因素.最后考察了温度、pH值和接种量对TF-1降解CB的影响,结果发现,该菌株适宜生长的温度范围为20~35℃,最适温度为30℃;适宜生长pH值为5~9,最适pH值为7;最适接种量为5%.与现有菌株比较发现TF-1的温度和pH值适用范围更广,降解能力更强,污染物耐受浓度更高,既能同化又能共代谢降解CB,在贫营养和富营养污染场地中应用潜力更大.本研究可为原位CB污染场地修复提供有效的生物资源.     

主观性在环境侵权案件证据和证明中的作用研究

法院在审理环境侵权案件时,往往依赖于专业鉴定、行政标准、专家意见等等客观依据来确定案件事实.但因为环境问题的复杂性,以及民事主体自身举证能力的限制,经常出现双方举证均不充分,法院无法基于现有事实和证据得出结论的情况.此时,法官应当发挥自身能动性,主动应用主观的、甚至是非科学性的因素和手段,包括容忍义务、经验法则、自由心证等等,这些因素无法被赋予客观的标准,它需要法官基于自身的理性以及经验,结合社会一般观念、习惯等因素进行判断.     

Environmental refuge from disease-driven amphibian extinction

Species that are tolerant of broad environmental gradients may be less vulnerable to epizootic outbreaks of disease. Chytridriomycosis, caused by the fungus Batrachochytrium dendrobatidis, has been linked to extirpations and extinctions of amphibian species in many regions. The pathogen thrives in cool, moist environments, and high amphibian mortality rates have commonly occurred during chytridiomycosis outbreaks in amphibian populations in high-elevation tropical rainforests. In Australia several high-elevation species, including the armored mist frog (Litoria lorica), which is designated as critically endangered by the International Union for the Conservation of Nature (IUCN), were believed to have gone extinct during chytridiomycosis outbreaks in the 1980s and early 1990s. Species with greater elevational ranges disappeared from higher elevations, but remained common in the lowlands. In June 2008, we surveyed a stream in a high-elevation dry sclerophyll forest and discovered a previously unknown population of L. lorica and a population of the waterfall frog (Litoria nannotis). We conducted 6 additional surveys in June 2008, September 2008, March 2009, and August 2009. Prevalences of B. dendrobatidis infection (number infected per total sampled) were consistently high in frogs (mean 82.5%, minimum 69%) of both species and in tadpoles (100%) during both winter (starting July) and summer (starting February). However, no individuals of either species showed clinical signs of disease, and they remained abundant (3.25 - 8.75 individuals of L. lorica and 6.5-12.5 individuals of L. nannotis found/person/100 m over 13 months). The high-elevation dry sclerophyll site had little canopy cover, low annual precipitation, and a more defined dry season than a nearby rainforest site, where L. nannotis was more negatively affected by chytridiomycosis. We hypothesize this lack of canopy cover allowed the rocks on which frogs perched to warm up, thereby slowing growth and reproduction of the pathogen on the hosts. In addition, we suggest surveys for apparently extinct or rare species should not be limited to core environments.     

Review: Biomechanics of Child Occupant Protection

This paper provides a review on the following issues: the differences in injury patterns between adults and children under similar loading conditions during an automotive crash event. Because of the recent awareness and the ensuing necessity, as an example, injuries including fatalities due to airbag deployment are discussed. Biomechanical differences explain the varying injury patterns and mechanisms of injury. The commonly adopted scaling techniques for predicting pediatric tolerances are described. A comparison of the biomechanical properties of the pediatric and adult structures is given. Some insight is provided with regard to the use of these data to develop validated mathematical models of pediatric structures. The paper concludes with recommendations for further research.     

Soil metal concentrations and productivity of Betula populifolia (gray birch) as measured by field spectrometry and incremental annual growth in an abandoned urban Brownfield in New Jersey

A forested brownfield within Liberty State Park, Jersey City, New Jersey, USA, has soils with arsenic, chromium, lead, zinc and vanadium at concentrations above those considered ambient for the area. Using both satellite imagery and field spectral measurements, this study examines plant productivity at the assemblage and individual specimen level. Longer term growth trends (basal area increase in tree cores) were also studied. Leaf chlorophyll content within the hardwood assemblage showed a threshold model for metal tolerance, decreasing significantly beyond a soil total metal load (TML) of 3.0. Biomass production (calculated with RG - Red/Green Ratio Index) in Betula populifolia (gray birch), the co-dominant tree species, had an inverse relationship with the Zn concentration in leaf tissue during the growing season. Growth of B. populifolia exhibited a significant relationship with TML. Assemblage level NDVI and individual tree NDVI also had significant decreases with increasing TML. Ecosystem function measured as plant production is impaired at a critical soil metal load.     

铬离子对SBR工艺活性污泥毒性作用研究

针对重金属铬离子对SBR工艺系统中活性污泥的毒性作用,通过检测不同初始污泥容积指数(SVI)下SBR工艺活性污泥在不同铬负荷下的COD值、挥发性污泥浓度以及受铬离子影响的污泥容积指数(SVI),研究重金属铬离子对活性污泥的毒性作用以及对SBR工艺系统处理污水的影响。研究表明,重金属铬离子会导致SBR工艺系统出水COD升高;将铬离子对活性污泥的毒性作用按照挥发性污泥(MLVSS)铬负荷可划分为耐受范围、非耐受范围、细胞失活范围以及细胞分解范围。耐受范围铬负荷低于约30 mg Cr3+/gMLVSS,此范围内铬离子对于活性污泥的毒性作用不大,不致于导致系统出水水质变差;非耐受范围铬负荷在约30~65 mg Cr3+/g MLVSS,在铬离子作用下系统出水COD值明显高于对照系统;细胞失活范围铬负荷在约70~100 mg Cr3+/gMLVSS范围内,SVI大幅下降,微生物部份死亡和失活,出水COD尽管有一些下降,但与进水COD相比差不了多少;细胞分解范围铬负荷在约100 mg Cr3+/gMLVSS以上,微生物大量死亡,部分死亡细胞分解,系统出水COD值因微生物的死亡分解而超出进水COD值,受铬离子影响的系统SVI值大幅度降低。