浅析两种高加速度冲击装置

高加速度和窄小脉宽一直是冲击试验设备制造者研究的主题。本文通过对生产实践中解决这一难题的两种装置使用方法和实践效果的对比分析,向广大的设备生产者和使用者介绍了两种装置的优缺点,供大家参考。     

基于退化量分布与退化轨迹的两种加速退化数据贮存寿命评估方法对比

首先陈述了加速退化数据的两种评估方法,对比两种评估方法的主要过程和适用范围.结合同一个试验数据,用两种方法分别进行处理,对比分析两种方法的评估结果.     

两山论、两条底线与自然资源治理

自然资源的科学管理与永续利用,不仅关系到多个产业部门的发展,还是习近平生态文明思想的重点关注问题。生态文明建设背景下的自然资源治理,应满足并促进多元主体参与下的不同利益诉求与协同发展。经济发展新形势下资源约束愈发显著,产业供给端的自然资源治理问题是可持续发展的关键要素。本研究结合两山论,通过对自然资源治理与人类活动发展间的内在关系进行分析,指出坚守两条底线的贵州实践是两山论持续深化生态文明建设的理论演进与验证。进而结合利益相关方的需求满足,梳理三者间联系与特性,以其核心理念为主线,围绕"生态系统服务、生态系统保护、区域经济发展"的目标功能实现,构建一种多元主体下的自然资源治理体系,并分析其约束条件与运行模式,以区域实践探析其目标功能实现与重要理论延展。最后提出应在产业发展与多方参与层面上统一思想认识,有利于新型治理途径的构建与探索。     

A/O生化池和BAF生物滤池的组合应用

较为全面地介绍了A/O生化池和BAF生物滤池两级生化合并的应用原理和效果,对两级生化的进出水水质进行了分析,并对系统运行中存在的问题进行了阐述。     

两种消解方法对测定沉积物中重金属含量的比较研究

实验采用王水提取和四酸消解两种不同的消解方法,对沉积物实际样品进行前处理,用火焰原子吸收法测定其中铜（Cu）、锌（Zn）、铬（Cr）、铅（Pb）、镍（Ni）的含量。对数据进行比较分析,发现Cu,Zn元素通过两种消解方法测得结果相近,Cr,Pb,Ni元素则有明显差异。对数据结果进行皮尔逊相关性分析,结果显示,除了Cu与Ni,Cr的相关性略差,其余元素均存在显著相关性。     

外场可靠性试验技术方法研究

介绍了外场可靠性试验的特点,概括总结了进行外场装备可靠性评价时应注意的几个方面。针对外场任务和系统级可靠性试验都属于可修复系统,重点分析了设备级以上可靠性数据处理方法,提出建立R.M.S数据库时应考虑的两个因素,即与寿命有关的可靠性增长分析以及DT和OT数据的合并,指出今后应建立适合外场数据特点的实用模型和方法,从而获得更准确的可靠性数据。     

ICP-MS法测定含油固体废物金属元素及两种消解方法比较

比较电热板消解和微波消解两种消解方法对测定含油固体废物金属元素的影响,并通过电感耦合等离子体质谱(ICP-MS)法测定其中10种金属元素的含量。通过F检验验证两种消解方法的差异,结果表明:电热板消解和微波消解两种消解方法对测定数据准确性无显著影响,但微波消解具有精密度好、耗酸量少、不易引入污染、消解彻底、用时较短等优势。进一步对微波消解体系和ICP-MS分析条件进行优化后发现,采用HNO_3-H_2O_2-HF混合酸体系微波消解含油固体废物样品后以~(103 )Rh作为内标元素,能够有效校正含油固体废物样品基体干扰。元素检出限为0.06～1.8mg/L,相对标准偏差在2.99%～9.63%的范围内,加标回收率在89.4%～113%之间。该方法耗酸量少,灵敏度高,快速准确,能够应用于含油固体废物中金属元素的测定。     

渤海海峡跨海通道对两大半岛城市群经济联系影响分析

跨海通道作为一种新型快捷的交通方式,其建设对端点地区的交通运输和经济发展都将产生深远的影响.以渤海海峡跨海通道南北端点两大半岛城市群——山东半岛城市群和辽中南城市群为研究区域,采用断裂点和城市引力模型方法计算分析渤海海峡跨海通道对两大半岛城市群城市间经济联系的影响.研究表明,在渤海海峡跨海通道的影响下,两大半岛城市群城市间经济联系强度显著增强.     

关于不确定度评定中两个问题的讨论

通过对环境监测仪器分析不确定度评定中,标准不确定度和相对标准不确定度的单位来源以及关于相对标准不确定度两种计算方法的讨论,得出标准不确定度是有量纲的、相对标准不确定度是无量纲的;最大允许误差较易获得,用这种方法计算不确定度有很好的可靠性。相对标准偏差计算不确定度则结果更好。     

不锈钢在两种腐蚀试验方法的结果比较

通过标准GM 9540P和GMW 14872两种方法的试验,评价了不锈钢SUH409L、B409和409DG的耐蚀性,两种方法的结果表明三种不锈钢的耐蚀性能由强至弱依次为SUH409L〉B409〉409DG。     

两利相权与两弊相权

“认识到,许多美丽的、种类繁多的野生动物和植物,是地球自然系统中无可代替的一部分,为了我们这一代和今后世世代代,必须加以保护;意识到,从美学、科学、文化、娱乐和经济观点看,野生动植物的价值都在日益增长;认识到,各国人民和国家是而且应该是本国野生动植物的最好保护者;并且认识到,为了保护某些野生动物和植物物种不致由于国际贸易而遭到过度开发利用,国际合作是必要的;确信,为此目的迫切需要采取适当措施……”     

试论环境政治学的两大分支及其关系

环境政治学是培养环境人才的必要课程之一。通过探讨环境政治学的概念和研究对象,论述环境政治包括国内环境政治和国际环境政治这两个分支四个方面的联系。     

不同载体对淀粉酶固定化的比较研究

采用海藻酸钠微胶囊法和壳聚糖交联法对淀粉酶进行固定化,比较两种淀粉酶固定化方法的优劣。结果表明,两种固定化酶的活力回收分别为33．2％、26．6％,比活力分别为27．1U／mg蛋白、24．2U／mg蛋白,最适pH分别为5．0、8．0。海藻酸钠微胶囊法热稳定性、pH稳定性、操作稳定性、贮存稳定性明显高于壳聚糖交联法,因此海藻酸钠微胶囊法较佳,具有一定应用价值。     

Two paradigms of professional development in environmental education

Summary In environmental education in this information age, it is particularly important to adopt the approach of enquiring critically into the environmental, educational and social values informing environmental, educational and social actions when and where required, rather than to simply adopt the approach of emphasising the acquisition and retention of information of an alleged universal type — information drawn from the stockpile of objective knowledge collected by others. This paper argues that to achieve this aim, environmental education in an information age requires aparadigm shift in the areas of professional development — a shift from a paradigm of information technology to a paradigm of information critique. A perspective on the form of this paradigm shift in the particular field of professional development in environmental education is the subject of this paper.Dr Ian Robottom is Senior Lecturer in the Curriculum Studies Centre of the School of Education, at Deakin University, Australia. His main interests lie in teacher education, educational enquiry, and environmental education. He conducts an off-campus environmental education course (B.Ed level) for practising teachers studying at a distance, is a member of the Council of the Australian Association for Environmental Education., and Editor of theAustralian Journal of Environmental Education.     

The Comparative Accuracy of Two Hydrologic Models in Simulating Warm‐Season Runoff for Two Small,Hillslope Catchments

This article assesses the performance of two hydrologic models in simulating warm‐season runoff for two upland, low‐yield micro‐catchments near Coshocton, Ohio. The two models, namely the Storm Water Management Model (SWMM) and the Gridded Surface‐Subsurface Hydrologic Analysis (GSSHA), were implemented with contrasting levels of complexity, with the former representing the catchments as lumped spatial units and computing evaporation only from standing water, and the latter incorporating fine‐scale variation in topography and soil properties and computing evapotranspiration from soil based on weather data. Our investigation began with uncalibrated model runs for 1990‐2003 except for 1994 using a priori parameter values. Then a set of calibration experiments were performed wherein the sensitivity of model performance to the length of calibration records was examined. Our results pointed to large errors associated with simulations from both models: even the calibrated models were unable to reproduce the seasonal and between‐catchment contrasts in runoff response. Using a priori parameter values, SWMM attained better results than GSSHA. However, with simple calibration, GSSHA outperformed SWMM in several respects. It was also found that extending the record of calibration rendered relatively minor changes to model performance. The practical and scientific implications of the findings are discussed.     

两起突发辐射环境事件的模拟监测

近两年来四川省成都、绵阳两市相继发生两起辐射环境事件,为澄清事实,消除公众疑虑,四川省辐射环境管理监测中心站对两事件分别开展模拟监测。着重介绍两事件的模拟监测情况,并对事件的影响进行评估。最终消除了公众的疑虑,维护了社会稳定。     

有关生物的两则趣例分析

趣例一:可怜鸟兽父母心我们常说:"可怜天下父母心."无疑那是专指人类的.但同是天下的芸芸众生,包括各种鸟兽,有无父母之心呢?回答当然是肯定的,没有父母,哪来后代呢?     

Taking Consumers Seriously: Two Concepts of Consumer Sovereignty

Governments, producers, and international free tradeorganizations like the World Trade Organization (WTO) areincreasingly confronted with consumers who not only buy (or don'tbuy) goods, but also demand that those goods are producedconforming to certain ethical (often diverse) standards. Not onlysafety and health belong to these ethical ideals, but animalwelfare, environmental concerns, labor circumstances, and fairtrade. However, this phantom haunts the dusty world of social andpolitical philosophy as well. The new concept ``consumersovereignty' bypasses the conceptual dichotomy of consumer andcitizen.According to the narrow liberal response to this newconstellation, with respect to food one should conceptualizeconsumer sovereignty as the right of the individual consumer toget information on food products and to make his or her ownchoice on the market of food products. In this conception, thereis a very strong emphasis on rules and principles with respect tothe autonomy of individuals.I argue that these narrow liberal concepts are not sufficient forappropriate public policy-making in democratic societies, andthat they only enable us to identify problems; they do not helpnon-experts (and experts, if it comes to that, as well) inweighing the different ethical claims. Besides, not onlyprinciples play a role in the outcome, but all kinds of ideals aswell, like roles, values, and norms. My principal argument isthat analysis or justification of norms or principles is notsufficient to get a synthesis or construction of ethicalsolutions: we need some value orientation to guide us inbalancing the different ethical claims by solving an ethicalproblem. Moreover, this balancing is something that requiressocial space and social time, i.e., public debates. With theconcept of public debates a whole new dimension enters ethicalanalysis, because the attention of ethicists shifts toformulating criteria of successful and rational public debates.However, in the broad liberal view these concepts aresupplemented with values, preferences, practices of care, andinvolvement. I argue firstly for a broadened perspective on foodas an integral part of life styles and not only as something thatpresents risks. That is the reason that food gets such intensiveattention from the public, which is summarized in the concept ofconsumer concerns. Secondly, I defend the argument that not only(rational) public debates, but intensive commitments of bothproducers and consumers in every link of the chain in so calledcare practices or consumer councils can enhance confidence in thefood production system and the way we extract our daily intakefrom nature.