碳纳米管对2-硝基苯酚和2,4-二氯苯酚的吸附特性研究

研究多壁碳纳米管对水中2-硝基苯酚和2,4-二氯苯酚的吸附规律.测定不同温度下两物质的吸附等温线,研究吸附的热力学特性和吸附机理.结果表明,碳纳米管对2-硝基苯酚和2,4-二氯苯酚具有良好的吸附效果,饱和吸附量分别达到24.54 mg/g和30.53mg/g.用Freundlich等温方程拟合碳纳米管对两种化合物的吸附,其线性相关系数均大于0.95;用Clapeyron-Clausius方程拟合吸附过程,两种物质的线性相关系数都达0.99.293～353 K时,碳纳米管对2-硝基苯酚吸附的△H、△G、△S分别为-7.74～-7.05 kJ·mol-1、-6.14～-4.80 kJ·mol-1、-8.33～-3.00 J·mol-1·K-1;对2.4-二氯苯酚吸附的△H、△G、△S分别为-24.75～-17.78 kJ·mol-1、-6.79～-6.22kJ·mol-1、-61.29～-32.75 J·mol-1·K-1.由于对酚分子π-π共轭作用的强弱不同.碳纳米管对2,4-二氯苯酚的吸附能力大于2-硝基苯酚.本文得到的碳纳米管吸附规律,为研究碳纳米管吸附含苯环类物质提供了参考.     

聚氯乙烯电缆料老化前后的火灾危险性研究

利用微型燃烧量热计（MCC）、热重分析（TGA）、实时红外光谱（RTFTIR）以及热重-红外联用技术（TG-FT-IR）研究了PVC电缆料老化前后火灾危险性的变化。MCC结果表明,老化后的PVC的最大热释放速率增加了56.3%,总热释放量从10.6kJ/g增加到16.8kJ/g,点燃温度也由302℃提前到282℃。TG-FTIR和RTFTIR的分析结果显示,PVC的主要降解产物有水、碳氢化合物、二氧化碳和一氧化碳。PVC达到最大降解速率的温度约为240℃,与MCC、TG的结果相符合。PVC的裂解气体中包含CO2和CO,还有剧毒气体HCl。这些实验数据说明PVC材料在使用过程中火灾危险性加大,为老城区电气线路和设备的改造提供了理论依据和实验基础。     

重构煤炭主体专业教育的公益性

从煤炭主体专业教育具有的公益性属性分析入手,指出煤炭主体专业的办学经费日紧和煤炭主体专业边缘化与去煤化,公益性日渐式微。建议从国家、高校、企业、个人家庭等各个层次全方位重构煤炭主体专业教育的公益性,加强国家利益至上,强化政府主渠道作用,在政策与教育投入要向其倾斜,优先发展与保障煤炭主体专业的教育,制定相关法规确保煤炭专业生源与人才培养质量,并在该领域就业。国家、企业、高校与个人家庭利益相关者都应在制度上强化各自应有的责任,从而形成一个多层次全方位良性互动发展的培养与吸纳人才的机制,确保煤炭主体专业教育的公益性,促进煤炭主体专业健康发展,满足安全生产的人才需求的供给,从而为煤炭安全生产提供重要保障。     

Bird species migration ratio in East Asia, Australia, and surrounding islands

Bird migration and its relationship with the contemporary environment have attracted long-term discussion. We calculated the avian migration ratio (the proportion of breeding species that migrate) in the areas from 70°E to 180°E and examined its relationship with the annual ranges of ambient temperature, primary productivity (estimated by the Enhanced Vegetation Index), and precipitation, along with island isolation and elevational range. The avian migration ratio increased with increasing latitude in general but varied greatly between the two hemispheres. Additionally, it showed minimal differences between continents and islands. Our analyses revealed that the seasonality of ambient temperature, which represents the energy expenditure of birds, is the dominant factor in determining bird species migration. Seasonality in primary productivity and other environmental factors play an indirect or limited role in bird species migration. The lower avian migration ratio in the Southern Hemisphere can be attributed to its paleogeographical isolation, stable paleoclimate, and warm contemporary environment. Under current trends of global warming, our findings should lead to further studies of the impact of warming on bird migration.     

沉水植物黑藻腐解过程中营养盐释放过程

为探究沉水植物衰亡过程中营养盐的释放规律,采用黑藻(Hydrilla verticillata Royle)作为研究用沉水植物,在实验室内模拟了黑藻在初春温度下腐解过程中的主要营养盐碳、氮、磷的释放过程.结果表明:黑藻在试验初期迅速腐解,该过程中向水体释放大量碳(81.31%)、氮(81.62%)、磷(85.94%).但随着时间的推移,黑藻向水体释放的磷大部分沉积进入底泥,而氮有部分沉积进入底泥,同时有部分以气体形式移出水体.黑藻腐烂分解产生的厌氧条件以及高TOC供给促进水体反硝化作用加快氮素移出水体.但是较大生物残留量会引起水体缺氧,植物残体分解加剧,导致水质严重恶化,因此需要适时收割水生植物来控制水体残留生物量.     

FT-ICR mass spectrometry for molecular characterization of water-insoluble organic compounds in winter atmospheric fine particulate matters

Water-insoluble organic compounds（WIOCs） are an important fraction of atmospheric fine particulate matters(PM_2.5), which could affect the climate system and threaten human health potentially. In this study, molecular characterization of WIOCs in PM_2.5 were investigated by 15 T Fourier transform ion cyclotron resonance mass spectrometry（FT-ICR MS） with atmospheric pressure photoionization（APPI） source in positive ion mode. A total of 2573 and1875 molecular formulas were iden...     

辽河流域河流栖息地评价指标与评价方法研究

建立了由底质、栖息地复杂性、速度-深度结合特性、堤岸稳定性、河道变化、河水水量状况、植被多样性、水质状况、人类活动强度和河岸土地利用类型所构成的河流栖息地评价指标体系,确定了各指标的等级划分以及栖息地综合指数的计算方法.结合2005年辽河流域河流生态调查结果,对流域内所调查的28个河段的栖息地质量状况进行了具体评价,并进一步分析了河道栖息地综合指数与河流理化因子、底栖生物以及小流域土地利用状况的相关关系.结果表明:①辽河流域28个河段的栖息地质量状况差异显著,其中10个河段达到了较好等级以上,6个仅为中等水平,12个河段为较差等级以下;②栖息地质量与理化因子、底栖生物指标具有显著相关性,表明栖息地质量是影响水质与生物状况的重要因素;③小流域的人类未利用土地比例与栖息地质量显著相关,表明小流域土地利用程度对栖息地环境质量影响较大,是恢复与保护河流栖息地质量的重要条件.     

环渤海海岸大气微塑料污染时空分布特征与表面形貌

微塑料污染已成为国内外的热点环境问题.目前,针对大气环境中微塑料污染的研究仅在少数地区开展.为比较环渤海沿海城市大气微塑料污染的长周期分布特征,本研究以烟台、天津和大连3个城市为例,于2018年6月—2019年5月进行大气沉降样品的采集,经体视显微镜、扫描电子显微镜和显微傅里叶红外光谱仪观察,分析了大气微塑料的类型、颜色、粒径、成分、微观形貌及主要成分等特征,并计算了微塑料的大气沉降通量.结果表明,在3个采样点大气沉降样品中共同存在纤维、薄膜、碎片和颗粒4种类型的微塑料,其中绝大部分为纤维类（>90%）.大气沉降微塑料的颜色主要包括透明、蓝色、红色、黑色等;粒径大多<1 mm.大气沉降样品中的微塑料主要成分为赛璐玢（>50%）和聚对苯二甲酸乙二醇酯（>30%）,且微塑料表面存在明显风化特征.烟台、天津和大连地区单位面积微塑料年沉降量分别为2.7×10⁴、8.9×10⁴和7.2×10⁴粒·m^-2.研究结果可为环渤海海岸城市大气微塑料污染与防控研究提供科学依据.     

OH自由基降解二英OCDD的反应机理及动力学研究

采用量子化学计算研究了OH自由基降解八氯代二苯并对-二英（OCDD）的微观反应机理,计算分析了微观反应进程,结果表明该反应存在两条途径：①α-氯取代：1,4,6,9位置氯取代,该路径反应活化能较高,反应难以进行,并以中间产物积聚,无法使OCDD的毒性消失;②β-氯取代：2,3,7,8位置氯取代,该路径的反应能相对较低,且能使OCDD的毒性消失,是有效降解OCDD的主要途径.结合过渡态理论,计算获得动力学参数：反应活化能为8.32 kJ·mol^-1（B3LYP/6-311G++（d,g）//B3LYP/6-31G（d））,阿仑尼乌斯表达式为k=1.29×10¹⁴exp（-1049.6/T）（cm³·mole^-1·s^-1）.这与文献实验结果取得了很好的吻合,说明本文对OH自由基降解OCDD的反应机理及动力学研究是合理且可靠的.本文的计算结果可为催化氧化降解二英的进一步研究提供理论参考.     

Integrated assessment of river health based on water quality, aquatic life and physical habitat

The health conditions of Liao River were assessed using 25 sampling sites in April 2005, with water quality index, biotic index and physical habitat quality index. Based on the method of cluster analysis (CA) for water quality indices, it revealed that heavily polluted sites of Liao River are located at estuary and mainstream. The aquatic species surveyed were attached algae and benthic invertebrates. The result showed that the diversity and biomass of attached algae and benthic index of biotic integrity (B-IBI) were degrading as the chemical and physical quality of water bodies deteriorating. Physiochemical parameters, BOD5, CODCr, TN, TP, NH3-N, DO, petroleum hydrocarbon and conductivity, were statistically analyzed with principal component analysis and correlation analysis. The statistical results were incorporated into the integrated assessing water quality index, combining fecal coliform count, attached algae diversity, B-IBI and physical habitat quality score. A comprehensive integrated assessing system of river ecological health was established. Based on the systimetic assesment, the assessed sites are categorized into 9 “healthy” and “sub-healthy” sites and 8 “sub-sick” and “sick” sites.