建立基于J2EE的气象预警系统

根据气象服务的需求，建立基于J2EE的气象预警系统体系结构，较好地满足可靠性、扩展性、可用性业务需要。文中讨论了J2EE在组件开发、数据库访问、负载平衡与多线程等多项关键技术在建立分布、动态、实际问题的应用。     

Kinetic modeling of Fe‐BEA as NH3‐SCR catalyst—effect of phosphorous

The focus of this work is to investigate whether a previously developed microkinetic deactivation model for hydrothermally treated Fe‐BEA as NH₃‐SCR catalyst can be applied to describe chemical deactivation of Fe‐BEA due to phosphorous exposure. The model describes the experiments well for Fe‐BEA before and after phosphorous exposure by decreasing the site density, representing deactivation of sites due to formation of metaphosphates blocking the active iron sites, while the kinetic parameters are kept constant. Furthermore, the results show that the activity for low‐temperature selective catalytic reduction (SCR) is very sensitive to loss of active monomeric iron species due to phosphorous poisoning compared to high‐temperature SCR. Finally, the ammonia inhibition simulations show that exposure to phosphorous may affect the internal transport of ammonia between ammonia storage sites buffering the active iron sites, which results in a lower SCR performance during transient conditions. © 2014 American Institute of Chemical Engineers AIChE J, 61: 215–223, 2015     

关于BEA域技术处理的探讨

BEASystems,Inc.是全球领先的计算机应用基础件公司,提供企业软件基础架构。其所开发的行业领先的应用服务器WLS提供了一种全新的方法来构建、集成、保护和管理服务器端的java应用。本文讨论了WLS域中的基本组成要素并对这些组成要素的运用进行了分析。     

关于BEA域技术处理的探讨

BEA Systems，Inc．是全球领先的计算机应用基础件公司，提供企业软件基础架构。其所开发的行业领先的应用服务器WLS提供了一种全新的方法采构建、集成、保护和管理服务器端的java应用。本文讨论了WLS域中的基本组成要素并对这些组成要素的运用进行了分析。     

Remarkable effect of the preparation method on the state of vanadium in BEA zeolite: Lattice and extra-lattice V species

The state of vanadium in two BEA zeolites is investigated by XRD, FTIR, DR UV–vis and EPR. One of the samples, VAlBEA (1.3 wt.% of V), is prepared by conventional ion exchange and the other, VSiBEA (2.0 wt.% of V), by a two-step postsynthesis method involving dealuminated BEA zeolite. No structural changes are observed after incorporation of vanadium into AlBEA zeolite by ion-exchange method. In contrast, the impregnation of SiBEA with V(IV) (VOSO₄) precursor leads to an increase of unit cell parameters of the BEA, to the consumption of silanol groups in vacant T-sites and incorporation of V in the framework of BEA zeolite as well dispersed tetrahedral V(V) species. NO and CO used as IR probe molecules, DR UV–vis and EPR allow to establish the oxidation state of vanadium in as prepared, oxidized, activated and reduced VAlBEA and VSiBEA zeolites. The IR spectra of oxidized, activated and reduced VAlBEA samples are very similar. It suggests that V introduced by ion exchange in extra-lattice position is stabilized on all samples in similar oxidation state. CO adsorption evidence the presence of vanadium in IV oxidation state via IR bands at about 2200 and 2180 cm⁻¹ assigned to V(IV)–CO monocarbonyl and V(IV)–(CO)₂ dicarbonyl species. In contrast, the oxidation state of V in VSiBEA changes strongly in function of calcinations in oxygen, outgassing at high temperature (773 K) and reducing with hydrogen at high temperature (873 K). This shows that lattice tetrahedral V species change easily oxidation state and this property allows them to be good candidate as active site of selective redox reactions.     

An information-integrated framework to support e-Manufacturing

The information integration of geometric design, finite/boundary element analysis (FEA/BEA), and numerical control (NC) machining is an important issue in e-Manufacturing and product development in geographically distributed sites. In this paper, a unified information-integrated framework based on XML (the eXtensible Markup Language) was created to support e-Manufacturing and integrate geometric design, FEA/BEA, and NC machining via the Internet. The structures of DTDs (Document Type Definitions) and XML files of geometric design, FEA/BEA, and NC machining were developed. Key technologies of supporting the XML-based integration and information communication, such as SAX (the Simple API (Application Programming Interface) for XML), DOM (the Document Object Model), SOAP (Simple Object Access Protocol), etc., are discussed. XML-based information integration via the Internet will shorten the development cycle, save costs in product development, and, finally, improve the competitive capability of e-Manufacturing in the global competition of product development.     

Occurrence and levels of mycotoxins and their metabolites in human breast milk associated to dietary habits and other factors: A systematic literature review, 1984–2015

BackgroundMany studies around the world reported the occurrence of many mycotoxins and their metabolites in human breast milk. However the contamination by aflatoxin M1 and ochratoxin A were the most investigated by several countries.Scope and approachTo scrutinize all papers reporting quantitative data on the prevalence and the levels of mycotoxins and their metabolites in breast milk, also the circumstances of exposure.A systematic literature search in Pubmed, Science direct and Google scholar databases were performed to identify relevant studies, published in English from 1984 through May 2015.Key findings and conclusion63 studies met the inclusion criteria and assessed the occurrence of 29 mycotoxins & their metabolites in breast milk, regarding 7194 subjects of 31 countries. The maternal dietary habits, the socio demographic status of the mother, the seasonal variations and the sensitivity of the analytical method were the factors related to the high concentrations of AFM1 and OTA in breast milk.Studies where contamination exceeds maximum limits and exhibit real risk of public health were highlighted.     

Sequential Template Decomposition to Adjust the Performance of Imperfect Zeolite BEA Membranes

Zeolite membranes offer superior thermal, chemical, and mechanical stability compared to polymeric membranes. However, it is still a challenge to prepare completely defect‐free membranes without any intercrystalline voids, which is necessary for gas separation processes. In this study zeolite beta (*BEA) membranes on stainless‐steel supports were prepared by applying the multiple in situ crystallization technique. The membranes were used as a model system to systematically study the decomposition of the organic structure directing agent tetraethylammoniumhydroxide (TEA‐OH). It was evaluated if the organic decomposition products of TEA‐OH can be used for enhancing the membranes selectivity. Post‐treatment experiments have been carried out to adjust surface properties and pore size dimensions in the zeolitic membrane layer. The results show that membranes calcined at lower temperatures exhibit a higher gas selectivity.     

Study of the selective catalytic reduction of NOx on an efficient Fe/HBEA zeolite catalyst for heavy duty diesel engines

The present paper addresses the removal of NO_x from the exhaust of heavy duty vehicles using the SCR technique. The studies were conducted with a highly active H-BEA zeolite exhibiting a molar Si/Al ratio of 12.5 and a Fe load of 1.0 wt.% (1Fe/HBEA). The pronounced efficiency of 1Fe/HBEA is reflected by the apparent turnover frequency being superior to traditional V₂O₅/WO₃/TiO₂. The nature of the Fe sites was investigated with high resolution transmission electron microscopy (HRTEM), ⁵⁷Fe Mössbauer spectroscopy and powder X-ray diffraction (PXRD). In connection with previous examinations it is deduced that the iron sites represent octahedrally coordinated high spin Fe³⁺ cations. Furthermore, highly dispersed species, which are the most active sites, are supposed to be paramagnetic, while oligomeric and particulate structures indicate superparamagnetic behaviour.The practical evaluation of the 1Fe/HBEA catalyst was systematically carried out including laboratory studies of granulated powder and honeycomb samples as well as engine bench tests. For the latter studies a coated honeycomb prototype was employed showing very similar efficiency as referred to a commercial V₂O₅/WO₃/TiO₂ pattern.Furthermore, 1Fe/HBEA exhibits pronounced hydrothermal stability after aging at 550 °C which represents an elevated exhaust temperature of heavy duty vehicles. The aging caused no change in fast SCR, i.e. when a c(NO₂)/c(NO_x) ratio of 0.5 was used, and only minor decline in standard SCR. The slight aging effect is mainly referred to little decrease in BET surface area and NH₃ uptake, respectively. PXRD indicated maintenance of the BEA structure, whereas ²⁷Al nuclear magnetic resonance spectroscopy showed removal of some Al from the zeolite framework. Contrary, UV–vis spectroscopy evidenced no effect of hydrothermal aging on the composition of the Fe sites. Finally, the catalyst also maintained its efficiency after SO₂ aging at 300 °C. Diffuse reflectance infrared Fourier transform spectroscopic studies showed adsorption of molecular SO₂ on the zeolite substrate releasing already at about 400 °C.