Two-dimensional numerical and eco-toxicological modeling of chemical spills

The effects of chemical spills on aquatic nontarget organisms were evaluated in this study. Based on a review of three types of current eco-toxicological models of chemicals, i.e., ACQUATOX model of the US-EPA, Hudson River Model of PCBs, and critical body residual (CBR) model and dynamic energy budget (DEBtox) model, this paper presents an uncoupled numerical ecotoxicological model. The transport and transformation of spilled chemicals were simulated by a chemical transport model (including flow and sediment transport), and the mortalities of an organism caused by the chemicals were simulated by the extended threshold damage model, separately. Due to extreme scarcity of data, this model was applied to two hypothetical cases of chemical spills happening upstream of a lake. Theoretical analysis and simulated results indicated that this model is capable of reasonably predicting the acute effects of chemical spills on aquatic ecosystems or organism killings.     

天然河流的二维等效扩散模型

通过对天然河流流带的拉伸或压缩处理，使之成为处处流速和水深均相等的理想河流，在此基础上建立了等效二维扩散模型。文中对建模方法和参数计算方法作了详细的介绍。     

Rapid FLASH NMR imaging

Nuclear magnetic resonance (NMR) spectroscopy and imaging provide new tools for non-invasive investigations of living systems. Recent developments in rapid NMR imaging now offer considerable improvements for both scientific applications and medical diagnosis. Using fast imaging sequences cross-sectional images may be recorded within seconds and, therefore, become free from motional artifacts due to breathing or peristalsis. New functional imaging experiments include dynamic studies of the application of paramagnetic contrast agents or ECG-synchronized recordings of cardiac NMR movies. Superior anatomical information is achieved by three-dimensional NMR imaging with measuring times of minutes rather than hours.     

Two-dimensional spectrophotometry and pseudo-color representation of chemical reaction patterns

The formation of spatio-temporal patterns in layers of chemical and biochemical media is observed and quantified by a two-dimensional spectrophotometer based on a computerized video equipment with high spatial, temporal, and intensity resolution. Images are shown, to some extent, in pseudo-colors. The use of pseudo-colors and three-dimensional perspective representations enhances the perception of the information contained in an image and the inherent order of the spatial structures.     

基于二维码技术的三华李种植溯源系统

根据农产品从生产到销售过程的发展现状及需求,设计出了基于二维码技术的三华李种植溯源系统。该系统采用PHP为主要开发语言,数据库则选用My SQL关系型数据库,搭建Apache为Web服务器;采用MVC设计模式,通过对MVC模式的理解和运用,能很好地将软件模块化,分离系统的数据控制和数据表示功能;以二维码技术为核心,对三华李的生长过程进行全面溯源,最后形成产品溯源二维码;基于响应式设计,可满足不同权限的用户群体的使用要求,实现对应的角色权限管理。     

基于二维水动力水质模拟下水环境容量的求解研究

由于受到适用条件有限、计算烦琐等方面的限制,目前许多水环境容量计算方法难以得到广泛应用,采用了影响系数法,在二维水动力水质模拟的基础上,以下边界上最大浓度点为控制点,计算区域的水环境容量,并对长江仪征工业用水区的水环境容量进行了计算,得出该河段环境容量为17 969.2t/a.该方法计算简单,且综合考虑了控制点的浓度,污染源位置,河流水文,水力学特性等多种因素,是一种非常有效且值得推广的计算方法,可为该区域水资源保护规划提供依据.     

激光拉曼光谱法测定生物燃气的气体组分

文章提出了一种基于激光拉曼光谱仪的生物燃气气体组分含量的快速分析方法,实现了生物燃气中C_1~C_3、H_2、O_2、N_2、CO、CO_2共11种气体成分的同时测定。通过实验测定、计算CH_4主峰处其他气体相对于CH_4的折算系数,解决了拉曼光谱中存在的重叠峰使CH4测量不准确的问题。同时通过实验和分析确定了合理的积分时间和气体压力。实验表明,所有组分都能被测量出来,并且测量的绝对误差小于1%,基本满足生物燃气组分含量的现场分析的精度和稳定性要求。     

二维高阶Boussinesq数值模型及其实验验证

基于近似到O(μ2)阶完全非线性的Boussinesq方程,在非交错网格下,建立了有限差分的波浪数学模型.针对该数学模型,利用混合四阶Adams-Bashforth-Moulton预报-校正格式对该方程进行了数值求解.计算了几组地形下的波浪传播变形,数值计算结果与实验结果吻合较好,验证了该波浪数值模型.同时给出了弱非线性方程数值模型的计算结果,讨论了非线性的影响.     

Two-dimensional numerical algorithm for water qualitymodeling in the topographically complicated river

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近红外光腔衰荡光谱系统设计及研究

目的搭建一套近红外光腔衰荡光谱测量系统,实现水汽吸收的探测。方法通过测量有无样品存在时的衰荡时间,实现腔内介质吸收的探测。通过测量空腔衰荡时间,计算腔镜反射率。通过测量不同浓度的水汽吸收,验证系统是否可用于分子吸收的测量。结果该装置的空腔衰荡时间约为3.75μs,对应的腔镜反射率为99.982%,有效吸收光程为1.1 km。测量了6627.7 cm~(-1)处水汽的吸收,结果与HITRAN数据库一致。结合文献报道结果和HITRAN数据库吸收谱线,模拟得到了NH_3、C_2H_2、HO_2自由基在6625～6626 cm~(-1)范围内的吸收系数。结论该装置实现了水汽吸收的探测,在该装置的激光器工作波长范围内,可应用于NH_3、C_2H_2、HO_2自由基的实时探测。     

长光程差分吸收光谱法

长光程差分吸收光谱法是一种实时、在线监测方法 ,可同时对多种气体进行连续监测。使用这种方法获得的数据经计算机处理后 ,可分析出大气中各种污染物的含量。介绍了这种方法的基本原理、仪器结构及它的应用。     

Two-dimensional correlation spectroscopic analysis on the interaction between humic acids and aluminum coagulant

In this study, two-dimensional correlation spectroscopy integrated with synchronous fluorescence and infrared absorption spectroscopy was employed to investigate the interaction between humic acids and aluminum coagulant at slightly acidic and neutral p H. Higher fluorescence quenching was produced for fulvic-like and humic-like fractions at p H 5. At p H 5, the humic-like fractions originating from the carboxylic acid, carboxyl and polysaccharide compounds were bound to aluminum first, followed by the fulvic-like fractions originating from the carboxyl and polysaccharide compounds. This finding also demonstrated that the activated functional groups of HA were involved in forming the Al-HA complex, which was accompanied by the removal of other groups by co-precipitation.Meanwhile, at p H 7, almost no fluorescence quenching occurred, and surface complexation was observed to occur, in which the activated functional groups were absorbed on the amorphous Al(OH)3. Two-dimensional FT-IR correlation spectroscopy indicated the sequence of HA structural change during coagulation with aluminum, with IR bands affected in the order of COOH COO-NH deformation of amide Ⅱ aliphatic hydroxyl C\OH at p H 5, and COO-aliphatic hydroxyl C\OH at p H 7. This study provides a promising pathway for analysis and insight into the priority of functional groups in the interaction between organic matters and metal coagulants.     

作用于斜坡结构物上海冰荷载的二维计算

海冰荷载是结冰海区海洋工程结构物设计的控制荷载，当结构物迎冰面具有倾斜表面时，海冰将发生弯曲破坏，从而大大降低海冰荷载值。本文针对一个单位宽度的简单斜坡结构物，分析冰板作用于斜坡结构时的破坏机理，提出基本假定，建立一个通用的二维计算模式，并对给定的工程结构物的海冰设计条件进行海冰荷载计算，给出了作用于斜坡结构上的冰荷载值。     

石墨炉原子吸收法测定土壤中的锡

研究了硝酸－高氯酸体系消解、石墨炉原子吸收法测定土壤中锡的方法。采用酒石酸－锆复合溶液作基体改进剂,锆涂层热解石墨管为原子化器。方法的检出限为3μg/L(样品消解溶液)。实际样品测定的相对标准偏差小于7.5%,加标回收率为90%～97%。      

三维荧光指纹技术用于城市湖泊的有机污染监测

有机物的荧光特性被广泛用来解析其在水体中的来源与分布。荧光光谱技术具有灵敏度高、选择性好、且不破坏样品结构的优点,非常适合用来研究有机物的化学和物理性质。运用三维荧光指纹技术对N市某城市湖泊的有机污染类型和污染程度进行了监测。实验结果表明,三维荧光指纹技术能有效揭示城市湖泊中有机物的动态变化。从七月份到十二月份,N市某城市湖泊的主要有机污染类型为内源污染;其中七月份到九月份还兼有外源污染,而十月份到十二月份基本没有外源污染。实验期间,此城市湖泊水体中C lass III（类蛋白）荧光峰的荧光强度在416.10~298.76之间,C lass I（类腐殖酸）荧光峰的荧光强度在128.90~123.19之间,此城市湖泊的内源污染远大于外源污染。     

拉曼光谱在水质分析中的应用进展

近年来,水污染事件频发并带来严重的社会后果,如何才能行之有效的检验水质的好坏,采取何种水质分析技术至关重要。传统水质分析方法存在步骤繁琐等弊端。拉曼光谱是一种研究物质结构快速有效的方法,目前广泛应用于多个领域,但在水质分析中的应用讨论依然为数不多。拉曼光谱能够在不破坏水样的前提下快速准确的检测水质,为日常水质监督检测及水污染事件发生后快速找到污染源提供积极有效的帮助。本文概述了拉曼光谱用于水质分析的原理及优势,详细评述了拉曼光谱在水质分析领域中的研究成果,并对拉曼光谱用于水质分析的未来进行展望。