氧弹法测定固体生物质燃料中氯含量的研究

试验了用氧弹法测定固体生物质燃料中氯含量的新方法,确定了最佳灰化条件.该方法操作简便、快捷、成本低,分析精度及准确度满足相关行业要求,值得进一步研究、推广.     

Model Catalysts from Single Crystal to Nanocrystals/Nano-Composites

<正>Heterogeneous catalysis is a key technology for chemical and materials synthesis,fuel production,power generation and conversion,and environmental remediation.To cope with resources(energy)shortage and environmental pollution,chemical processes should be not only effi cient but also clean,and catalysts must be active and selective.The innovation of such catalysts requires a fundamental understanding of the structure-activity relation of catalysts that can guide the design of catalyst structures.     

磷钾肥对公酿一号葡萄品种影响的效应分析

用磷酸二铵和硫酸钾对公酿一号葡萄品种进行不同时期、不同比例施肥,然后采用滴定等方法对其进行分析测定,结果发现,生长期施磷钾肥能明显提高果实可溶性固形物含量,降低可滴定酸含量,从而提高固酸比,同时作物产量有所提高.     

锂电池电解质电导率理论计算

非晶态电解质的电导率通常是由试验所测得,方法很多,但要受试验条件限制,因此所得结果和实际数值要有些差别,从理论上进行计算得到的结果要更接近其真实值.本文引用能斯特-爱因斯坦(Nernst-Einstein)方程,计算了非晶态电解质Li6Si2O2S5(Li2S-SiS2-Li4SiO4)的理论电导率为10-3S/cm.     

Characterization of suspended solids and particle-bound heavy metals in a first flush of highway runoff

To investigate the dynamic characteristics of total suspended solids （TSS） and their particle-bound heavy metals in a first flush, the runoff sampling together with its flow rate measuring was conducted for three rainfall events at outfalls of highway in Shanghai from June to September 2007. Field samples were analyzed to determine the concentrations of TSS and particle-bound heavy metals, such as Zn, Pb, and Cu. Results show that the wash offbehavior of TSS under varying runoffrate condition can be explained by different antecedent dry weather period （ADWP）. Contribution of fine fraction （〈45 μm） to TSS was generally higher than that of coarse fraction （〉45 μm）. When the runoff flow increased obviously, a significant contribution of the coarse fraction was observed for a certain rainfall events with long antecedent dry weather condition. The changes of total metals concentration and particle-bound metal concentrations were strongly dependent on the TSS variation. TSS was generally well correlated with most particulate-bound heavy metals. Of the heavy metals, the concentration of Zn was found considerably high and that of Pb was significantly low at North Zhongshan 2 Road, in Shanghai, China, but they are still within the range reported in the literature. Fluctuation of heavy metal contents in the coarse fraction during a first flush period was more significant compared with that in the fine fraction. The results will assist in the development of effective control strategies to minimize heavy metals and solids in highway runoff.     

苏丹中部北杰济拉省含水层的水化学特征

对苏丹中部的北杰济拉(Gezira)省地下水的水化学特征进行了评价，评价方法包括地下水主要离子浓度的监测分析及矿化度、钠离子、重碳酸根离子和氯离子浓度等值线图的绘制．对每个含水层的的水化学特征及其地下水的管理问题进行了深入讨论，并对地下水的适用性进行了详细分析．在含水层上部存在的化学成分含量较高及碳酸钙的存在，是蒸发作用和渗入量增加的结果．     

Neural network and principal component regression in non-destructive soluble solids content assessment: a comparison

Visible and near infrared spectroscopy is a non-destructive, green, and rapid technology that can be utilized to estimate the components of interest without conditioning it, as compared with classical analytical methods. The objective of this paper is to compare the performance of artificial neural network (ANN) (a nonlinear model) and principal component regression (PCR) (a linear model) based on visible and shortwave near infrared (VIS-SWNIR) (400–1000 nm) spectra in the non-destructive soluble solids content measurement of an apple. First, we used multiplicative scattering correction to pre-process the spectral data. Second, PCR was applied to estimate the optimal number of input variables. Third, the input variables with an optimal amount were used as the inputs of both multiple linear regression and ANN models. The initial weights and the number of hidden neurons were adjusted to optimize the performance of ANN. Findings suggest that the predictive performance of ANN with two hidden neurons outperforms that of PCR.     

Application Fourier transform near infrared spectrometer in rapid estimation of soluble solids content of intact citrus fruits

INTRODUCTION Soluble solids content (SSC) is a major charac- teristic used for assessing citrus fruit quality. Near-infrared spectroscopy (NIRS) has been used as a rapid and nondestructive technique for determining the soluble solids content of fruit. Kawano et al.(1992) measured sugar content of peaches in the wavelength region of 680~1235 nm. Their experiments indicated good correlation between the NIR spectra and the sugar content (r=0.97, SEP=0.05 °Brix). Slaughter (1995) devel…     

Mathematical contributions of Archimedes: Some nuggets

Archimedes is generally regarded as the greatest mathematician of antiquity and alongside Isaac Newton and C F Gauss as the top three of all times. He was also an excellent theoreticiancum-engineer who identified mathematical prob lems in his work on mechanics, got hints on their solution through engineering techniques and then solved those mathematical problems, many a time discovering fundamental results in mathematics, for instance, the concepts oflimits andintegration. In his own words,“… which I first dis covered by means of mechanics and then exhibited by means of geometry”. In this article we briefly describe some of his main contributions to mathematics.     

Measurement of soluble solids content in watermelon by Vis/NIR diffuse transmittance technique

INTRODUCTION Determination of fruit and vegetable quality is very important for both producers and processors. Watermelon as a delicious fruit has been widely ac-cepted in the world and its internal quality is impor-tant for consumers and merchants. The current fa-vorite way for checking a watermelon is to sense sound or vibration by slapping or rapping it. It is time consuming, tedious, and subject to error. Several studies on assessing the quality of watermelon based on its acoustic o…