腐殖(植)酸与食品源头安全--腐殖(植)酸是构筑食品源头安全的最佳选择

腐殖（植）酸（Humic Acid，以下简称HA）是天然有机化合物。在农业应用上十分广泛，主要有土壤改良剂、肥料、农药、植物生长剂、兽药、饲料添加剂、水产养殖剂等产品。从狭义的角度说，食品生产源头指土、水、肥、药、种等主要生产环节的硬条件。HA与食品生产源头诸要素之问关系密切。HA与土壤：土壤是种植业依赖的生命基础；HA是土壤有机质中的重要组成部分，也是最活跃的部分。HA与水：水是生命之源；HA在水生体系中普遍存在，是转运大多数生命必需物质甚至毒性物质的一种非常好的工具。HA与肥料：肥料是植物的粮食；HA在改良肥料、增加肥效、提高肥料利用率、协调各种营养等方面具有非常重要的作用。HA与农药：农药是植物的保护伞；HA具有提高农药药效、降低农药毒性、保护农业环境的基本条件。HA与种苗：种苗不好，作物不保；HA是孵化种苗的“保育剂”。除土、水、肥、药、种外，HA因其具有生理活性特征，而与种植业相关的诸多因素均有良好的协同作用。在此基础上，由HA开发的农用产品，涉足改土、活水、制肥、制药、种苗处理及其他衍生制剂等6大类产品，足以构筑起立体农业的防护体系，也是构筑食品源头安全的最佳选择。     

A comprehensive approach to evaluating watershed models for predicting river flow regimes critical to downstream ecosystem services

Selection of strategies that help reduce riverine inputs requires numerical models that accurately quantify hydrologic processes. While numerous models exist, information on how to evaluate and select the most robust models is limited. Toward this end, we developed a comprehensive approach that helps evaluate watershed models in their ability to simulate flow regimes critical to downstream ecosystem services. We demonstrated the method using the Soil and Water Assessment Tool (SWAT), the Hydrological Simulation Program–FORTRAN (HSPF) model, and Distributed Large Basin Runoff Model (DLBRM) applied to the Maumee River Basin (USA). The approach helped in identifying that each model simulated flows within acceptable ranges. However, each was limited in its ability to simulate flows triggered by extreme weather events, owing to algorithms not being optimized for such events and mismatched physiographic watershed conditions. Ultimately, we found HSPF to best predict river flow, whereas SWAT offered the most flexibility for evaluating agricultural management practices.     

SMS与飞机维修单位安全管理机制建设

SMS的核心理念是运用安全管理模式建立自我监督、自我完善、自我激励的安全机制,这种特性决定了按照传统自上而下的推进方式不能完全发挥出SMS“自系统”的优势,达到系统控制风险的目的。     

税收电子数据分析在煤炭企业税源管理工作中的研究与实践

随着信息技术的不断发展,利用先进技术成果挖掘和提炼税收电子数据信息,深化数据分析,为税源管理特别是重点税源管理工作服务,已经成为了现代税收发展的潮流。它是信息管税、风险控制的重要组成部分,也是各级税务机关、专家和学者在税源管理方面面临的重要课题之一。以朔州市国家税务局煤炭企业税收管理信息系统建设为背景,研究税收数据分析在税源管理工作中作用和意义。     

SSI:一种IPv6/IPv4多址同源识别模型

IPv6/IPv4共存环境下多址同源识别是共存网络管理与拓扑发现的一个关键问题。现有研究主要集中于子网内部的双栈发现及单一IP协议栈中的别名解析,难以识别远程IPv6/IPv4共存网络中的多址同源。通过分析同源地址间的本质联系,提出一种IPv6/IPv4多址同源识别模型(SSI),该模型综合利用特殊地址格式匹配、TCP时钟指纹比对和上层协议短时致瘫等多种方式来提高同源地址的识别能力。实验结果表明,上述方法均可有效识别IPv6/IPv4多址同源;SSI模型具有较理想的识别率和正确率。     

化工企业实现清洁生产的策略评述

概述了世界银行推进中国清洁生产项目中１０家化工企业的清洁生产审计结果，总结分析了化工企业实行污染预防持续发展的策略，并对我国化学工业实现清洁生产提出了具体建议。     

基于移动机器人的主动嗅觉技术研究

使用移动机器人来定位气味源已经成为一个研究热点,机器人主动嗅觉是指使用机器人自主发现并跟踪烟羽,最终确定气味源所在位置的技术。本文对当前主动嗅觉技术进行概述,并根据生物嗅觉行为介绍一种气味源定位算法,这种算法不依赖某一点气味浓度值,仅依靠气味浓度变化率就可找到气味源。并在高斯模型下对烟羽分布模型进行仿真。     

网络机房服务器监控平台的构建

利用开源软件Nagios构建服务器性能监控平台,对高校机房服务器的网络。关键应用和硬件主要指标进行Web可视化监控,把故障信息通过电子邮件和手机短信实时通知系统管理员。重点介绍了监控平台实现的基本原理和安装配置,并结合本校实际给出案例。     

基于开放源代码的防火墙实验项目设计

当前计算机网络安全课程已经广泛地开设于计算机及信息安全等相关专业,而防火墙技术又是计算机网络安全课程的重要内容之一。用专用硬件防火墙作为实验设备具有价格昂贵、内部技术不透明的缺点,因此本文设计一系列基于Linux操作系统开放源代码的防火墙技术实验,这样不仅可以降低教学实验成本,也能让学生更清楚地了解各种防火墙技术及实现,增强学生的专业实践能力。     

Assessment of a redox alkaline/iron-chelate absorption process for the removal of dilute hydrogen sulfide in air emissions

The oxidative absorption of hydrogen sulfide (H₂S) into a solution of ferric chelate of trans-1,2- diaminocyclohexanetetraacetate (CDTA) was studied in a counter-current laboratory column randomly packed with 15 mm plastic Ralu rings. The present investigation takes concern about the Kraft pulping situation where dilute H₂S concentrations are omnipresent in large-volume gas effluents. A fractional two-level factorial approach was instigated to determine the significance of six operating variables, namely the solution's alkalinity (pH; 8.5-10.5), the liquid mass flow rate (L;1.73-source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si78.gif">), the solution's ionic strength (I_C;0.01-source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si80.gif">), the gas mass flow rate (G;0.19-source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si82.gif">), the inlet H₂S concentration (C_H2S,0;70-430 ppm) and the initial ferric CDTA concentration (C_Fe,0;100 -source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si86.gif">). Initially, a Plackett-Burman design matrix of seven duplicated experiments revealed that pH is the leading factor controlling the H₂S conversion rate while the ionic strength and ferric CDTA concentration effects remained negligible within the factorial domain. Surface response analysis based on 11 duplicated factorial experiments plus 10 central composite trials revealed that the H₂S conversion significantly increases with liquid flow rate but decreases with growing H₂S load up. Further examination about the influence of ferric CDTA on H₂S absorption rate was set up over a broader concentration range (C_Fe,0;0-source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si92.gif"> at pH of 9.5 and 10.5. It showed good potential at source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0009250905003799-si93.gif"> as H₂S conversion increased by a significant 25% for both pH values in comparison to pure alkaline solutions containing no ferric CDTA.