高盐废水盐度对中度嗜盐菌生长动力学的影响

高盐废水盐度变化是影响微生物生长的重要因素之一。研究以中度嗜盐菌Halomonassp．STSY．3为例,测定其在不同盐度下生长对数期末OD600,并以葡萄糖为限制性基质,利用Monod方程,对菌株进行生长动力学拟合。结果表明,Halomonassp．STSY-3的最适生长盐度为7％（以NaCl计）,此盐度下其OD600 为2．56,而0%和34％盐度下OD600分别为0．47和0．06;Halomonassp．STSY-3的生长动力学模型与实验数据能较好地拟合,在最适生长盐度下动力学模型参数μmax 为2．257h-1,Ks为0．0082g／L。比较不同盐度下STSY-3生长动力学参数,得出中度嗜盐菌STSY-3的生长存在3个明显分区：最适盐度区（盐度2％～9％）、嗜盐过渡区（盐度9％～20％和0．68％～1．76％）及生长抑制区（盐度≤2％或≥20％）。其中嗜盐过渡区0．68％～1．76％由于范围较小,实际意义小,忽略不计。     

Rapid determination of polar pesticides and plant growth regulators in fruits and vegetables by liquid chromatography/tandem mass spectrometry

ABSTRACT

A simple high-throughput liquid chromatography/tandem mass spectrometry (LC-MS/MS) multiresidue analysis method was developed for the simultaneous determination of polar pesticides, plant growth regulators and other polar compounds. These included amitrole, chlormequat, mepiquat, cyromazine, ETU, PTU, perchlorate, and daminozide using a mixed-mode column. A 10 g test portion was shaken with acidified methanol for 10 min. After centrifugation, the sample extract was injected and analyzed within 11 min by LC-MS-MS. This column eliminated the need for derivatization or the use of ion paring reagent. Two MS-MS transitions were monitored in the method for each target compound to achieve true positive identification. Eight isotopically-labeled internal standards corresponding to each analyte were used to correct for matrix suppression effect and/or instrument signal drift. The average recovery for all analytes at 20, 40, and 250 ng/g (n = 6) ranged from 73–136%, with a relative standard deviation of ≤ 20%.     

青萍生长特征及其对受污染河水的修复效果

以浮萍优势品种青萍（Lemna minor）为研究对象,开展受污染河水修复。分析了青萍在不同营养盐浓度条件下的生长特征,探讨了青萍对受污染河水的修复效果。在表面积为0.0095 m2的限制空间条件下,青萍在1、2和5 mg总氮（TN）/L营养液中的生长特征都能较好地服从Logistic生长模型,受制约的临界鲜重（FW）分别为1.20、1.36和1.36 g;青萍对受污染河水中氮磷污染物具有较好的去除效果,氨氮（NH＋4-N）的平均去除率、平均去除量和平均去除速率分别为56.87%、1.22 mg/d和0.0466 mg/（g FW·h）,正磷酸盐（PO3-4-P）的平均去除率、平均去除量和平均去除速率分别为66.95%、0.25 mg/d和0.0088 mg/（g FW·h）。根据相关性分析,进水NH＋4-N和PO3-4-P浓度与其对应去除量之间极显著相关;青萍FW与NH＋4-N去除速率之间显著负相关,但与PO3-4-P去除速率之间不存在显著相关性;NH＋4-N进水浓度与去除速率相关性不显著,但PO3-4-P进水浓度与去除速率显著正相关。     

Future Nutrient Load Scenarios for the Baltic Sea Due to Climate and Lifestyle Changes

Dynamic model simulations of the future climate and projections of future lifestyles within the Baltic Sea Drainage Basin (BSDB) were considered in this study to estimate potential trends in future nutrient loads to the Baltic Sea. Total nitrogen and total phosphorus loads were estimated using a simple proxy based only on human population (to account for nutrient sources) and stream discharges (to account for nutrient transport). This population-discharge proxy provided a good estimate for nutrient loads across the seven sub-basins of the BSDB considered. All climate scenarios considered here produced increased nutrient loads to the Baltic Sea over the next 100 years. There was variation between the climate scenarios such that sub-basin and regional differences were seen in future nutrient runoff depending on the climate model and scenario considered. Regardless, the results of this study indicate that changes in lifestyle brought about through shifts in consumption and population potentially overshadow the climate effects on future nutrient runoff for the entire BSDB. Regionally, however, lifestyle changes appear relatively more important in the southern regions of the BSDB while climatic changes appear more important in the northern regions with regards to future increases in nutrient loads. From a whole-ecosystem management perspective of the BSDB, this implies that implementation of improved and targeted management practices can still bring about improved conditions in the Baltic Sea in the face of a warmer and wetter future climate.     

西安采暖期PM2.5及其水溶性无机离子的时段分布特征

为了探讨西安市采暖期大气颗粒物PM2.5及其水溶性无机成分的污染水平,于2010年1月4日—2月1日按一天8个时段(每个时段3 h)连续采集PM2.5样品四周,每周更换一次滤膜。结果显示,西安市采暖期PM2.5的质量浓度时段差异较大,呈现明显的双峰分布特征:21:00—24:00时段(147.516μg/m3)和09:00—12:00时段(141.678μg/m3)。4种被测水溶性无机组分总浓度为39.801μg/m3,占PM2.5总浓度的30.5%。SO24-和NO3-是最主要组分,占到4种无机组分的86.2%。各离子间相关分析显示,Cl-只与NO3-有较强的相关性,表明机动车尾气对Cl-有较大的贡献。SO24-和NO3-时段分布规律较为相似,与PM2.5浓度的时段分布特征相反:在PM2.5污染最轻的15:00—18:00时段,SO24-和NO3-的相对含量达到一天中的最高浓度时段,而在PM2.5双峰时段,它们的含量有所降低。     

The ecological traces of growth: economic growth,liberalization, increased consumption—and sustainable urban development?

Using the development of the building stock and physical infrastructure as an example, this article highlights the difficulties in combining continuous economic growth in wealthy countries with the requirements of environmentally sustainable development. There are clear limits as to how far we can get by means of ‘eco-efficiency’, and the effect of a transition to less environmentally harmful types of consumption is not sufficient if the consumption volume keeps on increasing. This is particularly evident for societal processes such as the construction of buildings and the development of physical infrastructure. Increased consumption is both a result of and a precondition for economic growth. The development of the building stock and physical infrastructure in cities is a case showing that economic growth—at any rate, in the longer term—can hardly be consistent with the preservation of species, ecosystems and food-production resources. The growth in the building stock also makes it increasingly difficult to limit energy use and reduce carbon–dioxide emissions. Copyright © 2001 John Wiley & Sons, Ltd.     

中国区域污染与经济增长实证:基于面板数据联立方程

考虑区域污染与区域经济增长的双向作用机制,构建联立方程模型,利用我国1998-2008年30个地区的面板数据,实证研究了6类区域污染物指标与区域经济增长的内在关系,对环境库兹涅茨曲线假说进行验证,探讨区域污染的主要影响因素。研究结果表明:①仅工业粉尘、工业SO2与GDP存在倒U型曲线关系,符合环境库兹涅茨曲线假说;工业废水、工业固废与GDP存在正的线性关系,工业废水中污染物化学需氧量、工业烟尘与GDP存在负的线性关系,不支持环境库兹涅茨曲线假说。指出并非经济发展到一定水平,区域污染问题就会得到全面解决。②人口规模对区域污染排放影响不显著;科技水平和能源利用率的提高能有效降低区域污染排放;政府环保管制未能有效控制区域污染排放;加大贸易开放程度对污染排放影响有正有负;产业结构不合理会加剧区域污染排放。③工业烟尘、工业SO2污染对区域经济增长有反作用。现阶段,我国区域污染对区域经济增长的反馈机制较弱,给我们敲醒了环保警钟。指出转变经济增长方式,走经济增长与环境保护协调发展的路子是我国今后的必然选择。     

外场可靠性试验技术方法研究

介绍了外场可靠性试验的特点,概括总结了进行外场装备可靠性评价时应注意的几个方面。针对外场任务和系统级可靠性试验都属于可修复系统,重点分析了设备级以上可靠性数据处理方法,提出建立R.M.S数据库时应考虑的两个因素,即与寿命有关的可靠性增长分析以及DT和OT数据的合并,指出今后应建立适合外场数据特点的实用模型和方法,从而获得更准确的可靠性数据。     

公共项目对经济增长的供给效应研究

近年来,政府在公共投资管理领域扮演的角色和发挥的功能正在发生变化,由过于追求项目的净收益到更加关注公共物品或服务所能产生的正的外部性的大小.所以,对公共项目特别是大型公共项目评价的方法、指标、标准开始转向加强从宏观视角的考察.公共项目投资对经济增长的促进作用表现为需求效应和供给效应两个方面.从我国目前的实际情况乃至未来若干年的情况来看,无论是道路交通等市政基础设施还是公共卫生、文教体育等社会基础设施都在不同程度上成为经济社会发展的"瓶颈",即处于长期的供不应求的状况,使其投资的供给效应对长期经济增长的提离推动作用是更为主要和显著.公共项目的供给效应是项目完成后,在长期的使用过程中逐次转移积累获得的经济效益,量化计算的理论基础是投入占用产出技术.该技术反映了国民经济这个开放的巨系统各部门产业之间的复杂联系,能够正确反映项目对长期经济增长带来的贡献,一般用感应度系数表示,数值越大表明对国民经济其他部门的推动能力越强.文章最后给出感应度系数计算模型和投资对GDP影响的计算模型.     

四川城市对称性空间结构研究

城市空间分布规律的研究一直是城市规划者和地理学家研究的热点。早期关于城市空间分布的理论有克里斯泰勒的中心地理论、廖什网络结构理论等,现在研究较热的是基于人类空间行为自组织演化的分形理论。我国著名地学家叶大年先生于2001年提出我国城市分布对称的思想,并将其系统整理为关于城市分布对称的学术思想。成渝经济区的崛起,为四川省城市空间结构的优化带来了重要的契机。依据叶大年先生的城市分布对称理论,认为四川主要城市在地质构造等自然地理要素的影响下对称分布明显,且盆西平原城市在天然水系特征和陆路交通干线共同影响下呈格子状分布。针对当前四川省主要城市空间结构发育的不成熟,对成渝经济区影响下的四川城市空间分布形态重新进行空间构建,首次提出关于四川城市空间结构的“钻石模型”。分析表明,此模型能够较好地解释当前川内城市的空间分布及演化趋势;同时也在一定程度上说明城市分布对称的思想具有一定的理论价值和实践价值,值得学者引起重视