水杨酸对梨叶感染轮纹菌后脂肪酸、叶绿素荧光参数和叶绿体超微结构的影响

用0.3 mmol L-1水杨酸预先处理梨叶片,3 d后接种轮纹病菌(Physalospora Piricola Nose),接种3 d后开始测定各种指标,随后每隔3 d测定1次,共5次.结果表明,经SA处理的梨叶片,感染轮纹病菌后不饱和脂肪酸含量(UFA)、不饱和脂肪酸指数(IUFA)、叶绿素含量、原初光能转换效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)、光合电子传递量子效率(ΦPSⅡ)和光化学猝灭系数(qP)比未经SA处理的相应提高;非光化学猝灭系数(qN)比未经SA处理的相应下降.电镜观察表明,部分叶绿体膨大,变形;基粒片层弯曲、散开;淀粉粒数量减少;经SA处理后,症状减轻.图3表1参20     

克拉玛依市区大气尘污染研究

通过对克拉玛依市区大气尘污染的特性及变化规律所进行的全面分析和研究,结果表明：市区的尘污染有加重的趋势,降尘属中度污染,针对现状,提出了大力植树造林;加强对建筑施工和道路改造施工现场的管理;加强对低空排放的小型燃煤锅炉的监督管理;充分利用石油天然气资源;强化以环境管理为中心的环境政策体系等五项具体措施。     

煤对CO2，N2和CH4的吸附速率经验公式与异同性研究*

为了解决吸附速率拟合公式缺乏而解吸经验公式众多的问题,通过替换解吸参数、定性和对比分析各经验公式对煤吸附CO₂,N₂,CH₄吸附速率的适用性,选取4种不同煤质的煤样在0.5,1.0和2.0 MPa下进行定温吸附实验,分析压力和煤质对吸附速率的影响规律。研究结果表明:时间函数式对3种气体在不同压力和煤质下的吸附速率拟合效果最佳;压力和煤质对3种气体吸附速率的影响既存在共性又具有差异性,气体吸附速率与压力符合指数函数关系,与挥发分呈现出二次函数关系,并且压力升高会导致最低吸附速率趋向于较高变质程度煤样;CH₄和N₂的吸附速率随压力升高而升高,而CO₂的吸附速率因煤样而不同,且在同压下,不同气体的最高和最低吸附速率煤样的变质程度也不同。     

Analysis of metabolic changes in Trichoderma asperellum TJ01 at different fermentation time-points by LC-QQQ-MS

Trichoderma spp. are among the most widely recognized biocontrol fungi used to inhibit pathogens and promote plant growth. These functions are related to primary and secondary metabolites. This study investigated the different metabolites in Trichoderma asperellum TJ01 cultured for 24 and 72?h using liquid chromatography with triple-quadrupole mass spectrometry. Compared to the 24?h culture of T. asperellum TJ01, the 72?h culture with amino acid metabolism tended to decrease while sugar and lipid metabolisms tended to increase. Furthermore, the 72?h culture had a higher proportion of upregulated flavonoids, in combination with a higher proportion of downregulated alkaloids, and equal proportions of upregulated and downregulated polyphenols and hormones. This study also identified a few valuable medicinal substances such as trigonelline and 5-hydroxytryptophan in T. asperellum TJ01 fermentation cultures.     

Evaluation of photolysis and hydrolysis of pyraclostrobin in aqueous solutions and its degradation products in paddy water

This study evaluated the hydrolysis and photolysis kinetics of pyraclostrobin in an aqueous solution using ultra-high-performance liquid chromatography–photodiode array detection and identified the resulting metabolites of pyraclostrobin by hydrolysis and photolysis in paddy water using high-resolution mass spectrometry coupled with liquid chromatography. The effect of solution pH, metal ions and surfactants on the hydrolysis of pyraclostrobin was explored. The hydrolysis half-lives of pyraclostrobin were 23.1–115.5?days and were stable in buffer solution at pH 5.0. The degradation rate of pyraclostrobin in an aqueous solution under sunlight was slower than that under UV photolysis reaction. The half-lives of pyraclostrobin in a buffer solution at pH 5.0, 7.0, 9.0 and in paddy water were less than 12?h under the two light irradiation types. The metabolites of the two processes were identified and compared to further understand the mechanisms underlying hydrolysis and photolysis of pyraclostrobin in natural water. The extracted ions obtained from paddy water were automatically annotated by Compound Discoverer software with manual confirmation of their fragments. Two metabolites were detected and identified in the pyraclostrobin hydrolysis, whereas three metabolites were detected and identified in the photolysis in paddy water.     

Determination of the residue dynamics and dietary risk of thiamethoxam and its metabolite clothianidin in citrus and soil by LC-MS/MS

A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method was developed for the determination of thiamethoxam and its metabolite clothianidin in citrus (including the whole citrus, peel and pulp) and soil samples by liquid chromatography-tandem mass spectrometry. The sample was extracted with acetonitrile and purified with octadecylsilane. The detection limits of both compounds were 0.0001–0.0002?mg kg^–1, while the limit of quantification of thiamethoxam was 0.002?mg kg^–1 and the limit of quantitation of metabolites was 0.001?mg kg^–1. The recovery was 70.37%–109.76%, with inter-day relative standard deviations (RSD) (n?=?15) values ≤9.46% for the two compounds in the four matrices. The degradation curve of thiamethoxam in whole citrus and soil was plotted using the first-order kinetic model. The half-life of the whole citrus was 1.9–6.2?days, and the half-life of the soil was 3.9–4.2?days. The terminal residue of thiamethoxam (the sum of thiamethoxam and clothianidin, expressed as thiamethoxam) was found to be concentrated on the peel. The final residual amount of thiamethoxam in the edible portion (pulp) was less than 0.061?mg kg^–1. The risk quotient values were all below 1, indicating that thiamethoxam as a citrus insecticide does not pose a health risk to humans at the recommended dosage.     

层次分析-熵值定权法在城市水环境承载力评价中的应用

从广义水环境承载力定义出发,建立水环境承载力评价指标体系;采用层次分析－熵值定权法和向量模法对武汉市水环境承载力进行评价,该定权方法采用层次分析法确定权重,同时又引入熵值法对权重进行修正,在一定程度上减少了主观影响。该方法使评价指标的赋权达到主观与客观统一,对水环境承载力的量化更加准确与合理。该方法构造简单,便于实现计算机编程,所以应用较为简单、方便。以武汉市为例,综合考虑资源环境以及社会经济发展,建立了一套指标体系,利用向量模法对指标进行量化,结果表明武汉市2006~2010年水环境承载力逐年增大,由0129 3增长到02411,表明近些年武汉市水资源、环境与社会经济的发展协调性较好。从3个准则层中可以看出,资源与环境对武汉市水环境承载力的影响较大;社会子系统承载力评价值逐年上升,且上升趋势较快;随着经济的加速发展,经济子系统承载力评价值呈逐年下降态势     

近十年鄱阳湖区极端干旱事件频发现象成因初析

近10 a来鄱阳湖区极端干旱事件频发,引起国内外媒体舆论的广泛关注。针对这一情况,运用流域降水、地表蒸散和出湖径流等数据,从流域水量收支平衡的角度,较为系统地分析了导致鄱阳湖区极端干旱事件频发的原因。结果表明,近10 a来鄱阳湖水文干旱起始日期提前,枯水期拉长。虽然干旱持续时间的长短呈现2~3 a的波动,但在总体上呈现逐渐加长的趋势。从流域水分收支的角度来看,近10 a来以水分亏缺为主,流域降水亏缺是基本的致旱因素,流域蒸散量增加则起到一定的增强作用,而出湖径流所起的作用比较复杂,在多数情况下其致旱的影响程度弱于流域降水作用。长江顶托作用强弱变化可以调节流域的水分收支平衡,强化或者减轻湖泊的干旱程度。2003、2004、2007、2008和2009年发生的极端干旱事件主要由流域水分收入项的大幅度减少所造成的,而长江水情变化在多数情况下加剧了流域水分收支的不平衡。这些研究结果明晰了鄱阳湖流域气象干旱与湖泊水文干旱之间的关系以及长江水情变化所扮演的重要角色,为应对未来的干旱变化和制定合理的抗旱防旱对策与措施提供了科学的依据     

长三角地区城市居民出行交通碳排放特征与影响机理

随着能源问题及全球变化关注,城市居民出行交通碳排放研究已成为多学科关注焦点。选择南京、宁波和常州作为长三角典型城市,基于典型居住小区问卷调查获取第一手的城市居民出行基础数据,估算与分析城市居民出行碳排放特征及影响机理。结果表明：长三角2010年城市居民人均出行交通碳排放约1 1219 kg CO2/人,日常通勤和远距离出行碳排放量之比为75[DK]∶25;城市居民日常通勤交通碳排放的主要影响因子为交通方式、出行距离、家庭年收入、年龄和性别;远距离出行交通碳排放的主要影响因子为出行距离、交通方式和家庭年收入。建议采用差别化的行政干预和经济杠杆有效调控家庭小汽车保有量增长速度,鼓励小排量汽车和清洁能源汽车消费,兼顾汽车产业发展、家庭小汽车刚性需求与节能减排需求之间的博弈平衡;优化城市功能格局,大力发展公共交通网络;加强节能减排与低碳意识宣传,鼓励与引导公共交通出行     

一体化臭氧-曝气生物滤池处理酸性玫瑰红印染模拟废水

针对含酸性玫瑰红印染废水高色度、难生物降解的特点,分别采用了一体化和分离式臭氧-曝气生物滤池(O3-BAF)工艺处理。与分离式工艺相比,一体化工艺的特点是在一个反应器内部同时实现臭氧氧化和生化的协同作用,降低了处理设施的基建和运行费用。实验结果表明,一体化工艺处理效果明显优于分离式工艺,脱色率达92%,COD去除率达60%,处理效果良好。