基于积分响应模型的气溶胶静电分级器设计与粒径分布测量

为改善气溶胶静电分级器分级测量性能,建立了其传递函数和积分响应理论模型.通过对关键参数理论模拟,设置了静电分级器样气流速、鞘气和样气流速比例等关键参数,并且通过试验对理论模型进行了验证,评价了该静电分级器分级测量性能.模拟结果表明,提高气流流速可以改善静电分级器的分级性能,而鞘气和样气流速比例过大会降低其传输效率,过小则会影响分辨率,流速比例可以设定为5~25.试验结果表明,积分响应理论计算的粒子数浓度与该静电分级器试验测量结果呈线性相关（R2=0.98）.研究显示,该静电分级器测量粒径与预测粒径的误差在5.0%以内,线性相关（R2=0.99）,且测量多个单分散和多分散粒径浓度谱型与商业化SMPS（scanning mobility particle sizer,扫描电迁移颗粒物粒径谱仪）基本一致,该传递函数和积分响应模型显著提高了静电分级器分级测量性能.      

Performance and recent improvement in microbial fuel cells for simultaneous carbon and nitrogen removal: A review

Microbial fuel cells (MFCs) have become a promising technology for wastewater treatment accompanying electricity generation. Carbon and nitrogen removal can be achieved by utilizing the electron transfer between the anode and cathode in an MFC. However, large-scale power production and high removal efficiency must be achieved at a low cost to make MFCs practical and economically competitive in the future. This article reviews the principles, feasibility and bottlenecks of MFCs for simultaneous carbon and nitrogen removal, the recent advances and prospective strategies for performance improvement, as well as the involved microbes and electron transfer mechanisms.     

The role of body size in early mating behavior in a simultaneous hermaphrodite, <Emphasis Type="Italic">Chelidonura sandrana</Emphasis>

Intraspecific variation in mating behavior is widespread among simultaneous hermaphrodites but its underlying sources remain largely unexplored. In the sea slug Chelidonura sandrana, most matings are reciprocal. However, despite non-conditional sperm exchange and potential polygamy-mediated benefits, 30% of matings end after unilateral insemination. To resolve this apparent inconsistency, we here investigated the effect of body size on the frequency of reciprocal matings by testing the following two hypotheses. First, sex-allocation theory predicts that the likelihood of reciprocity depends on the size difference between mating partners. Second, if both sex functions temporally differ in reaching maturity, reciprocal matings should be more frequent with increasing absolute body size of the smaller partner. The likelihood of reciprocity increased with body size of the smaller partner. Moreover, smaller individuals acted more often as males among unilateral matings. These findings suggest that the ability to donate sperm develops prior to female functionality in C. sandrana.     

生物脱氮新技术研究进展

本文对短程硝化反硝化、同时硝化反硝化及厌氧氨氧化等生物脱氮新技术的研究和开发进展进行了简单的综述和讨论 ,并指出了这些新技术的特点和研究开发应用的前景。     

哈希在线分析仪在石化废水COD测定中的应用

介绍了美国哈希公司COD在线分析仪的工作原理、仪器结构与测量步骤,以及在中石化金陵分公司污染源在线监测系统中的应用.分析了仪器常见故障产生的原因与排除方法,提出应注重仪器的日常运行检查,采取相应的质量控制措施,确保自动监测数据的有效性.     

连续流动分析仪测定环境水样中的硝酸盐氮

应用连续流动分析仪对环境水榈的NO3^--N进行了分析，简述了试剂浓度的确定原则和编写运行程度的方法。通过对标准样品的多次测定，测定值均在其保证值范围内，相对标准差为0．7％，准确度高，精密度好。方法检测限可达0.003mg/L NO3^--N，环境水样回标回收率在94％－102％之间，样品分析速率可达50个/h。     

Method validation for control determination of mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry

A method for the determination of total mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) has been validated following international foodstuff protocols in order to fulfill the Brazilian National Residue Control Plan. The experimental parameters have been previously studied and optimized according to specific legislation on validation and inorganic contaminants in foodstuff. Linearity, sensitivity, specificity, detection and quantification limits, precision (repeatability and within-laboratory reproducibility), robustness as well as accuracy of the method have been evaluated. Linearity of response was satisfactory for the two range concentrations available on the TDA AAS equipment, between approximately 25.0 and 200.0 μg kg^?1 (square regression) and 250.0 and 2000.0 μg kg^?1 (linear regression) of mercury. The residues for both ranges were homoscedastic and independent, with normal distribution. Correlation coefficients obtained for these ranges were higher than 0.995. Limits of quantification (LOQ) and of detection of the method (LDM), based on signal standard deviation (SD) for a low-in-mercury sample, were 3.0 and 1.0 μg kg^?1, respectively. Repeatability of the method was better than 4%. Within-laboratory reproducibility achieved a relative SD better than 6%. Robustness of the current method was evaluated and pointed sample mass as a significant factor. Accuracy (assessed as the analyte recovery) was calculated on basis of the repeatability, and ranged from 89% to 99%. The obtained results showed the suitability of the present method for direct mercury measurement in fresh fish and shrimp samples and the importance of monitoring the analysis conditions for food control purposes. Additionally, the competence of this method was recognized by accreditation under the standard ISO/IEC 17025.     

MA-2000型测汞仪直接测定环境水体中的汞

介绍了MA-2000型测汞仪测定环境水体中的汞,以氯化亚锡为还原剂,0．001％半胱氨酸为汞固定剂,在一定浓度范围内被测汞蒸汽在波长253．7nm紫外光下的吸收值与汞蒸汽浓度成正比。方法检出限0．006ng,精密度和准确度均满足水质监测实验室质量控制的要求。     

免耕与常规耕作下黑土腐殖酸含量与结构的差异

以东北农业科学院长期耕作定位实验为研究对象,结合元素分析和红外光谱来研究免耕与翻耕两种耕作方式对黑土腐殖酸含量与胡敏酸结构的影响。结果表明：免耕处理的腐殖酸含量高于常规耕作处理18.28%,两种耕作处理间HA/FA值差异很小;免耕处理的碳、氮和氢元素含量分别高于翻耕处理5.48%、36.49%和27.65%,N/C和H/C值也高于翻耕处理,而翻耕处理的O/C值高于免耕处理;不同耕作处理的红外光谱吸收带表现相似趋势,其中2920、2580、1620、1420和1220σ·cm-1处吸光度免耕信号高于翻耕,而1026、721σ·cm-1处吸光度相反。免耕增加了腐殖酸、胡敏酸及富里酸含量;免耕增加了黑土胡敏酸的芳香度、脂肪化程度和聚合程度,而翻耕作增加了黑土胡敏酸的氧化程度,这说明经过长达26年的免耕处理使黑土腐殖质结构趋于稳定,而翻耕处理使黑土腐殖质结构趋于简单。     

Application of spatial and non-spatial data analysis in determination of the factors that impact municipal solid waste generation rates in Turkey

In studies focusing on the factors that impact solid waste generation habits and rates, the potential spatial dependency in solid waste generation data is not considered in relating the waste generation rates to its determinants. In this study, spatial dependency is taken into account in determination of the significant socio-economic and climatic factors that may be of importance for the municipal solid waste (MSW) generation rates in different provinces of Turkey. Simultaneous spatial autoregression (SAR) and geographically weighted regression (GWR) models are used for the spatial data analyses. Similar to ordinary least squares regression (OLSR), regression coefficients are global in SAR model. In other words, the effect of a given independent variable on a dependent variable is valid for the whole country. Unlike OLSR or SAR, GWR reveals the local impact of a given factor (or independent variable) on the waste generation rates of different provinces. Results show that provinces within closer neighborhoods have similar MSW generation rates. On the other hand, this spatial autocorrelation is not very high for the exploratory variables considered in the study. OLSR and SAR models have similar regression coefficients. GWR is useful to indicate the local determinants of MSW generation rates. GWR model can be utilized to plan waste management activities at local scale including waste minimization, collection, treatment, and disposal. At global scale, the MSW generation rates in Turkey are significantly related to unemployment rate and asphalt-paved roads ratio. Yet, significances of these variables may diminish at local scale for some provinces. At local scale, different factors may be important in affecting MSW generation rates.