麻痹性贝毒素的毒理效应及检测技术

近年来世界各地，特别是我国浙江、广东等沿海地区赤潮发生过度频繁，许多赤潮生物分泌的毒素不但使其他海洋生物中毒，更会对人类健康造成潜在的危害。因此对赤潮毒素的研究已成为海洋环境科学研究的重要内容。麻痹性贝毒素是其中重要的一类赤潮藻毒素。它们毒性大，作用强，在全球的分布越来越广泛，并且已经在世界范围内造成了严重的危害，引起了国内外科学家的高度重视。本文详细综述了近年来国外在麻痹性贝毒素检测技术方面最新的研究进展，重点介绍了麻痹性贝毒素的化学结构、前处理技术和分析检测新技术及其毒性作用机理。     

Green supplier development: analytical evaluation using rough set theory

Suppliers' development is a critical function within supply chain management. Green supplier development is also necessary for effective green supply chain management. Interestingly, there is a gap in the research on how an organization can effectively manage supplier development programs, and specifically green supplier development. The use of formal models to aid green supplier development management is virtually non-existent. This paper aims to fill this gap by introducing a formal model using rough set theory to investigate the relationships between organizational attributes, supplier development program involvement attributes, and performance outcomes. The performance outcomes focus on environmental and business dimensions. The rough set methodology utilizes an ‘incomplete’ information approach which is more realistic in some data poor environments. A multistage rough set methodology is detailed through an illustrative application. The methodology generates decision rules relating the various attributes to the performance outcomes. Included in the discussion are insights into how these rules for individual and aggregated performance (environmental, business, and joint performance) may be evaluated. Practical and research implications of this work are detailed in the paper.     

An analytical force model for orthogonal elliptical vibration cutting technique

The elliptical vibration cutting (EVC) technique has been found to be a promising technique for ultraprecision machining of various materials. In each overlapping EVC cycle, the thickness of cut (TOC) of work material, and the tool velocity get continuously varied. These two inherent phenomena, in fact, introduce transient characteristics into its cutting mechanics, which are considered to be different from the one applied for conventional cutting technique. Recently, a few theoretical models have been developed to understand the material removal mechanism with the EVC technique; however, in those studies, the transient phenomena were not considered. In the present research, an analytical force model for the orthogonal EVC process was developed in order to fully understand the EVC mechanism, and to more accurately predict the transient cutting force values. Three important factors: (i) transient TOC, (ii) transient shear angle, and (iii) transition characteristic of friction reversal were investigated and analyzed mainly based on geometric modeling and the Lee and Shaffer's slip-line solution. Mathematical evaluation shows that they may have significant influence on EVC process, and thus on its output performance. In order to validate the proposed force model, a series of low-frequency orthogonal EVC tests were conducted. The experimental transient cutting force values were compared with the predicted values calculated using the proposed model, and they are found to be in a good agreement with each other.     

固相萃取-高效液相色谱法测定海水中多环芳烃

针对环境中常见且对人体危害极大的USEPA优先控制污染物多环芳烃(PAHs)在海水中的监测方法进行研究.以国家标准分析方法和美国环保局分析方法为基础,采用固相萃取-高效液相色谱法来测定.探讨了各条件对测定的影响,经过固相萃取,七种PAHs在反相高效液相色谱中有很好的分离效果,满意的回收率,方法简便,具有良好的应用前景.     

海水中溶解氨基酸分析技术的研究进展

随着对海洋中有机氮生物地球化学循环过程认识的逐步深入,氨基酸作为海洋有机氮库中最易被生物利用的组分之一愈加受到重视。关于海洋中氨基酸含量组成和生物可利用性的相关研究对认识海洋中有机氮的迁移和转化具有重要意义。本文详细阐述了海洋领域分光法和荧光法等溶解氨基酸测定方法及离子色谱和液相色谱等色谱分离方法的发展历程,并对应用最普遍的柱前衍生-反相液相色谱-荧光检测法等技术进行了更为详细的评述,列举了质谱技术、单体同位素分析技术和毛细管电泳等最新发展的技术方法,最后对其在海洋学中的应用进行展望。     

海洋沉积物中生物硅的分析技术研究进展

分析评述了海洋沉积物中生物硅分析方法的特点、影响因素和应用范围,并对沉积物中生物硅的测定方法存在的技术难点进行了总结和建议。海洋沉积物中生物硅的测定方法主要有4种方法,即基于对生物硅固相结构的分析方法(X射线衍射法和红外光谱法)、硅质微化石计数法、元素标准比值计算法、湿法碱化学提取法(单点提取法和连续提取法)。此外还有一些应用较少的方法,如高温滴定法、傅立叶变换红外光谱方法等。     

赤潮浮游植物种类和数量分析的研究进展

简要介绍了浮游植物种类和数量分析的8种方法的研究进展、应用现状,比较了各种方法的特点。基于浮游植物的外观形态特征而进行分析的方法除了传统的显微镜方法外,与计算机技术相结合的图像法使分析速度得以提高。基于浮游植物的色素组成而进行分析的有吸光光度法、荧光分光光度法和高压液相色谱法,可分至门类,同时定量,其中光度法可以直接测量海水,高压液相色谱法需萃取色素。流式细胞仪法的特点是可同时测量每个细胞的多个参数,运用神经网络分析可鉴别种类,应用时主要受限于仪器的操作和价格;化学发光流动注射法目前仅限于特定赤潮浮游植物的检测;分子探针法基于浮游植物的DNA特征,处于实验室研究阶段。     

Quantitative analysis of airborne breathable particles: A comparison between different analytical techniques

Air samples, collected over 6 months, have been analysed by scanning electron microscopy (SEM) with the aim to characterize quantitatively the airborne particulate in an urban area. Total suspended particulate (TSP) and Pb concentrations (in μg m⁻³) were estimated by inserting into a simple model the particulate data obtained by SEM.Daily concentration trends were compared with trends measured by gravimetric (TSP) and atomic absorption spectroscopy (Pb) techniques. The correlation coefficients resulted to be 0.8 for TSP and 0.85 for Pb. These results indicate that SEM can be used to have a good evaluation on pollution by airborne breathable particles.     

海洋环境中光合色素分析方法研究与应用进展

根据国内外的文献,综述了海洋环境中光合色素分析方法的发展状况,指出了其分析方法在发展过程中创新的主要方面,并对光合色素分析在赤潮监测、藻类的化学分类及生物碳生物量和矿物质通量方面的应用进行了展望。     

Robust prediction of chatter stability in milling based on the analytical chatter stability

A major obstacle that limits the productivity in machining operations is the presence of machine tool chatter. Machining is a dynamic process and chatter behavior depends upon a number of different aspects including spindle speeds, material properties, tool geometry, and even the location of tool respect to the rest of machine. Many of the traditional models used to predict chatter stability lobes assume that parameters such as natural frequency, stiffness, and cutting coefficients remain constant. In reality, these parameters vary and they affect the chatter stability. The uncertainty in these parameters can be taken into consideration by employing the robust stability theory into a two degree of freedom milling model. Utilizing the Edge theorem and the Zero Exclusion condition, a robust chatter stability model, based on the analytical chatter stability milling model, is developed. This improves the reliability compared to the projected pseudo single degree of freedom model. The method is verified experimentally for milling operations while considering a changing natural frequency and cutting coefficient.     

污染土壤和底泥中可提取态有机卤化物的分析方法研究

选用甲苯／正已烷、丙酮／正已烷两种混合溶剂作为污染土壤和底泥中可提取态有机卤化物的提取剂，与乙酸乙脂作为提取剂进行三种溶剂超声法提取效率的比较，采用微库仑法进行测定方法改进的研究。实验结果表明，采用1：9的丙酮／正乙烷混合溶剂的提取效率较高，其平均回收率与乙酸乙脂法接近，而且回收率范围比乙酸乙脂法波动更小。以1：9的丙酮／正已烷混合溶剂作为提取剂的方法还表明：无机可溶性卤化物对EOX测定不产生干扰，分析方法的最低检出浓度范围为0．1－0．4mg(Cl)/kg，测定范围为0－250．00mg(Cl)/kg，添加标准样品的相对标准偏差为3．38％－5．09％。     

Development of analytical methods for polycyclic aromatic hydrocarbons （PAHs） in airborne particulates： A review

In the present work, the different sample collection, pretreatment and analytical methods for polycyclic aromatic hydrocarbons （PAHs） in airborne particulates is systematacially reviewed, and the applications of these pretreatment and analytical methods for PAHs are compared in detail. Some comments on the future expectation are also presented.     

Atmospheric residence times for soluble species: Differences in numerical and analytical model results

We have compared numerically calculated soluble species residence times with several analytic residence time models. The numerical results are dependent on whether randomly or periodically distributed precipitation events are assumed. A preferred time of occurrence for rain, such as morning or afternoon, influences the computed HNO₃ residence time for precipitation cycle times (wet plus dry period) of about a day, but exerts less influence as the cycle time increases. An analytic residence time model developed by Rodhe and Grandell (1972, Tellus24, 442–454) is found to agree well with residence times computed for randomly distributed precipitation events while a model developed by Giorgi and Chameides (1985, J. geophys. Res.90, 7872–7880 is more suitable for periodic rain. The present numerical calculations resolve an apparent ambiguity in HNO₃ residence times computed in earlier numerical studies.Using mean precipitation periods and rainfall amounts characteristic of the northeastern U.S. as a guide, we find that residence times computed under the assumption of randomly distributed wet and dry events agree better with observed aerosol lifetimes than do those computed assuming periodic rain.     

Study of multiresidue analytical method for organonitrogen and organophosphorus pesticides in soil and water

A gas chromatographic method without derivatization was developed for the residue analysis of 10 organonitrogen and 9 organophosphorus pesticides in soil and water. The samples were blended or shaken with acetone for extraction. The extracts were cleaned up by coagulation, then, re-extracted with three 50 ml portions of dichloromethane. The final residue was detected by gas chromatography equipped with NPD. All of the 19 pesticides were completely separated at a constant temperature. The method described above was applicable to the simultaneous determination of 10 organonitrogen and 9 organophosphorus pesticides .in soil and water with the satisfactory recovery (from 82.42% to 103.57%), coefficient of variance (from 0.17% to 12.57%) and limit of detection (from 0.0006 ppm to 0.058 ppm).     

A review on analytical methods for pharmaceutical and personal care products and their transformation products

Pharmaceutical and personal care products (PPCPs) and corresponding transformation products have caused widespread concern due to their persistent emissions and potential toxicity. They have wide octanol-water partition coefficients (K_ow) and different ionization constants (pK_a) resulting in a poor analysis accuracy and efficiency. A suitable analytical method is the first prerequisite for further research on their environmental behavior to prioritize the substances. This study reviewed a full-scale analytical protocol for environmental samples in the recent ten years: from sampling to instrumental methods. Passive sampling techniques were compared and recommended for long-term continuous and scientific observation. A quick and effective sample extraction and clean-up method are highly required. Chromatographic methods coupled to mass spectrometry for determining PPCPs with a wide range of logK_ow (?7.53 to 10.80) were summed up. High-resolution mass spectrometry was confirmed to be a promising strategy for screening unknown transformation products, which would provide a nanogram level of detection limits and more accurate mass resolution. Screening strategies and mass change principles were summarized in detail. The recovery rate was important in multiple contaminants analysis identification and factors affecting the recovery rate of PPCPs were also discussed in this review, including sample matrix, target compounds characteristics, extraction method and solid-phase adsorbent. This review provides useful information for the selection of appropriate analytical methods and future development directions.     

考虑非线性吸附时溶质在有限厚度粘土中的一维扩散解

在采用非线性分段式吸附等温模式的基础上,建立了溶质在粘土中的一维扩散模型,在考虑有限厚度边界及土中溶质背景浓度的条件下得到了相应的解.模型引入了移动边界以说明当溶质在粘土孔隙水中的浓度达到某一较高值后,阻滞因子将发生显著变化.算例分析表明,该模型和考虑经典非线性吸附等温线得到的结果相差不大,这进一步说明了该模型的合理性.考虑非线性吸附效应对溶质迁移有重要影响.在较高溶质浓度下采用线性吸附等温模式会得到偏不安全的结果.该解相对较简单,并可用于验证各种数值模型、拟合试验数据等.     

大气气溶胶中硝基多环芳烃分析方法的建立及应用

硝基多环芳烃类化合物是一类强致突变和致癌物.大气中的硝基多环芳烃主要由化石类燃料燃烧时直接释放,或由前体化合物多环芳烃经光化学反应生成,其浓度远低于多环芳烃.利用高效液相色谱法,分离并富集目标组分,结合气相色谱-质谱技术,建立大气气溶胶中硝基多环芳烃类化合物的检测方法,仪器检测限为1.17～2.94pg,硝基多环芳烃指...