辽河水体中溶解有机质的光谱初步研究

文章分析了辽河流域水体中溶解有机质的吸收光谱,荧光特性及其主要来源。对比紫外可见吸收和散射2种模型,结果表明DOM对紫外可见光既有吸收也有散射。运用平行因子分析法(parallel factor analysis,PARAFAC),对三维荧光激发-发射矩阵(EEM)进行分析,发现3种荧光团,包括1种类蛋白荧光团和2种类腐殖质荧光团。荧光指数(FIX)为1.60～2.10,初步认为此时段辽河流域DOM的来源为多重来源,生物源比重较大。大多数SUVA_(254)在1.22～2.82L/(mg·m)之间,同文献报导的来自于土壤或者高等植物的DOM相比,值相对较小,DOM的芳构化程度较低,进一步表明DOM来源以生物源为主。     

采用人工地震波对大跨度刚构桥的地震响应分析

为获得大跨度刚构桥在多维多点地震激励下的响应特征,基于功率谱模型合成了满足给定相关函数的多维多点人工地震波。采用有限元软件SAP2000分别在线性与非线性领域对某大跨度刚构桥进行计算分析,研究刚构桥在多维多点地震下的响应特点。结果表明,多点激励下刚构桥主梁的横向弯矩往往较一致激励下的大;考虑非线性特性后,刚构桥在三向地震作用下的响应并不等于单向地震响应的简单叠加,且刚构桥的墩顶比墩底部位更易形成塑性铰,建议在实际工程中重视刚构桥墩顶部位的延性设计。     

Adding complex trophic interactions to a size-spectral plankton model: Emergent diversity patterns and limits on predictability

A new model in the NPZ (nutrient-phytoplankton-zooplankton) style is presented, mechanistically simple but with 40 size classes each of phytoplankton (1-20 μm) and small zooplankton (2.1-460 μm), in order to resolve one level of trophic interactions in detail. General, empirical allometric relationships are used to parameterize both the optimal prey size and size selectivity for each grazer class, as is rarely done. This inclusion of complex predator-prey linkages and realistic prey preferences yields a system with an emergent pattern of phytoplankton diversity consistent with global ocean observations, i.e., a parabolic relationship between diversity (as measured by the Shannon evenness) and biomass. It also yields significant long-term time evolution, which places limits on the extent to which the community response to nutrient forcing can be predicted from forcing in a pragmatic sense. When a simple annual cycle in nutrient supply is repeated exactly for many years, transient fluctuations up to a factor of two in spring bloom magnitude persist for 10-20 years before a stable seasonal biomass cycle is achieved. When the amplitude of the nutrient-supply annual cycle is given a random interannual modulation, these long-lived transients add significant noise to a 100-year correlation between annual-mean nutrient supply and annual-mean biomass. This noise is 20% of total interannual variance in the model base case, and ranges from 0% to 40% depending on the grazer size selectivity. In general, unpredictability on the bloom timescale is damped when food-web complexity is increased by making grazers less selective, while unpredictability on the interannual scale shows the opposite pattern, increasing with increasing food-web complexity up to a high threshhold, past which community structure and biomass time evolution both suddenly simplify. These results suggests a new strategy for ensemble ecosystem forecasting and uncertainty estimation, analogous to methods common in circulation and climate modeling, in which internal variability (predator-prey interactions in the biological case; eddies and climate-system oscillations in the physical case) are resolved and quantified, rather than suppressed.     

分层型水源水库溶解性有机物性质及其膜污染特性

利用激发-发射矩阵(EEM)荧光光谱和紫外吸收光谱研究了深水型水源水库热分层期溶解性有机物(DOM)性质及其膜污染特性随水深的变化.结果表明,水体热分层导致DOM质量浓度和性质也表现出分层特征.变温层受光化学降解影响较大,DOM质量浓度较低,同时受藻类等浮游植物分泌的内源有机物影响,DOM芳香度较低,类富里酸有机物(C1组分)和类腐殖酸有机物(C2组分)荧光强度较低,但类色氨酸有机物(C3组分)荧光强度较高;斜温层DOM受径流输入影响较大,DOM质量浓度和芳香度较高,C1和C2组分荧光强度较高.膜污染方面,变温层DOM造成的总污染最大,但可逆性较好,斜温层和等温层DOM造成的总污染较低,但可逆性较差;对超滤过程中不同荧光组分迁移的分析表明,超滤膜对C3组分截留率较高,但反冲洗对被截留的C3组分去除效果较好,而被膜截留的C1和C2组分较难被反冲洗去除.     

轮叶黑藻对铅的吸附特征及生物吸附机理研究

研究了轮叶黑藻对重金属铅的吸附特征,同时对吸附机理进行探讨.动力学研究结果表明,轮叶黑藻对铅有较快的吸附能力,10min后铅的去除率达到74.54%;20min后,吸附达到平衡.整个吸附过程符合伪二级动力学方程(R2=0.9910).Sips和Langmuir模型相比Freundlich而言,有着较好的拟合效果,表明轮叶黑藻对重金属铅的吸附属于单层吸附,相邻铅离子间的相互干扰可以忽略不计.红外光谱分析表明:轮叶黑藻叶片富含多种活性基团,羟基、羰基和羧基、C–O及C–N为主要作用基团.吸附铅后,轮叶黑藻叶片内K、Na、Ca、Mg含量明显下降,表明铅离子因产生离子交换而被吸附,且铅离子更易与二价的Ca和Mg产生离子交换.     

DC反应器处理中药废水过程中出水的光谱分析

采用三维荧光(EEM)与傅立叶红外(FTIR)光谱技术,对不同运行条件下,新型双循环(DC)厌氧反应器处理中药废水的出水情况进行了分析,以期为厌氧反应器的有效监控提供新思路.结果表明,在HRT为24h时,COD去除率为94%左右,平均产气率达到0.37m3CH4/kgCOD,出水的EEM光谱中,Ex/Em=420/470nm处出现了明显的辅酶F420吸收峰;而HRT减少为12h后,虽然COD去除率仍达到90%左右,但出水EEM光谱中,辅酶F420的吸收峰有所降低,并出现了类富里酸的吸收峰,表明不宜再继续减少HRT.当温度由30oC降低为20oC时,温度的变化影响了厌氧污泥的性状,使得出水的FTIR光谱中3400cm-1处的吸收峰由原来的钝峰变为尖峰.而在进水中添加大黄酸后,造成了反应器内有机酸的累积,产甲烷菌活性受到严重影响,出水的EEM光谱中,腐殖酸与类富里酸的吸收峰显著增强.     

Online recognition of drainage type based on UV-vis spectra and derivative neural network algorithm

• UV-vis absorption analyzer was applied in drainage type online recognition. • The UV-vis spectrum of four drainage types were collected and evaluated. • A convolutional neural network with multiple derivative inputs was established. • Effects of different network structures and input contents were compared. Optimizing sewage collection is important for water pollution control and wastewater treatment plants quality and efficiency improvement. Currently, the urban drainage pipeline network is upgrading to improve its classification and collection ability. However, there is a lack of efficient online monitoring and identification technology. UV-visible absorption spectrum probe is considered as a potential monitoring method due to its small size, reagent-free and fast detection. Because the performance parameters of probe like optic resolution, dynamic interval and signal-to-noise ratio are weak and high turbidity of sewage raises the noise level, it is necessary to extract shape features from the turbidity disturbed drainage spectrum for classification purposes. In this study, drainage network samples were online collected and tested, and four types were labeled according to sample sites and environment situation. Derivative spectrum were adopted to amplify the shape features, while convolutional neural network algorithm was established to conduct nonlinear spectrum classification. Influence of input and network structure on classification accuracy was compared. Original spectrum, first-order derivative spectrum and a combination of both were set to be three different inputs. Artificial neural network with or without convolutional layer were set be two different network structures. The results revealed a convolutional neural network combined with inputs of first and zero-order derivatives was proposed to have the best classification effect on domestic sewage, mixed rainwater, rainwater and industrial sewage. The recognition rate of industrial wastewater was 100%, and the recognition rate of domestic sewage and rainwater mixing system were over 90%.     

基于抛物线内插的反应谱计算公式及其精度分析

基于反应谱的基本概念,对基于抛物线内插法的反应谱计算公式进行了严格的推导,并给出了详细的显式表达式,建立了当计算时间等步长离散时的基于抛物线内插法的反应谱计算连锁公式。通过对比简谐波输入时的反应谱计算结果,证明基于抛物线内插法的连锁公式的计算结果比广泛应用的反应谱计算方法"精确法"计算的结果更接近于解析解,有更高的计算精度。同时对多条实际记录的地震加速度时程进行了反应谱对比计算,结果表明该公式在计算反应谱时也是稳定的。作者同时发现,"精确法"计算的反应谱值与实际值相比一般是偏小的。     

浒苔反射光谱库系统设计与实现

浒苔光谱特征是遥感之本,可为浒苔灾害的遥感实时监测与预警研究提供重要基础数据。本文基于Delphi开发工具和Interbase数据库平台,采用"面向应用"的系统开发方法,运用dbExpress、DataSnap技术和TeeChart组件,设计并实现了浒苔反射光谱数据库系统,利用本系统可以实现对海量浒苔光谱数据及其属性信息的共享、信息查询、可视化分析和管理等功能。     

Cu~(2+)离子与蛋白质混合体系相互作用机制研究

应用荧光光谱法研究Cu2+离子与血清蛋白质混合组份体系的结合反应机制,测定了反应体系的结合常数K、结合位点数n,探讨了荧光猝灭机理。同时探索了Cu2+与蛋白质混合组份体系及单一组份体系相互作用的差异。结果表明:混合组份体系中,牛血清白蛋白(Bovine serum albumin,BSA)与牛乳铁蛋白(Bovine lactoferrin,BLF)分子间也存在着相互作用,从而影响混合组份体系中BSA/BLF与Cu2+的相互作用,Cu2+与蛋白质混合组份体系相互作用并非蛋白质单组份体系作用之和。分析实验数据,首次发现当BSA/BLF达到临界比值时,金属离子与混合蛋白质组份相互作用过程中出现了蛋白质分子的"契合"现象。文章利用生物酶反应机制中的酶活性部位柔性假说合理解释了Cu2+与血清蛋白质混合组份体系相互作用中的"量敏效应"。