“人类世”:为你我寻一个新坐标

说起“地质年代”,我们首先联想到的可能是“寒武纪生命大爆发”、“侏罗纪恐龙”.也可能你知道现在我们人类处于1万年前开始的“全新世”,但由于地质年代主要以化石记录来区分,动辄以百万年为单位,所以对于大多数人而言,不同的“纪”或“世”仅仅区分着静态的过去.     

一种连接器振动故障分析

目的 分析得出轴向弹性触碰式连接器内导体失效的主要原因。方法 以某机载电子模块的连接器在功能振动试验后出现的故障为研究对象,对其进行目测检查、随机振动仿真分析和受力分析,定位故障原因,随后结合应力应变关系公式、高斯区间法和Miner累积损伤定律,推导内导体的疲劳寿命计算公式。结果计算得到内导体自身的振动响应应力仅为0.26 MPa,不足以产生疲劳破坏,但在振动激励下,连接器随模块的振动位移较大,超出了连接器的间隙容差范围,致使受压的内导体端面出现较大的往复动摩擦力,而摩擦力引起内导体根部的应力（250.13 MPa）超过了材料的疲劳极限,内导体有疲劳断裂的风险。进一步计算出内导体的振动疲劳寿命为0.67 h,小于功能振动试验时间,证实是振动位移引起的摩擦导致了内导体的疲劳断裂。结论 轴向弹性触碰式连接器必须要重视摩擦力的危害,提高模块的安装刚度,可以有效地提高连接器的可靠性。     

Hydrogen for a sustainable global economy

The topic of this special issue of the Journal of Cleaner Production is “Sustainable Hydrogen from Biomass.” It is of interest to practitioners in the energy sector, governmental policy makers, researchers, educators, as well as to the general public. The purpose of this special issue is to increase public awareness and to stimulate exchange of information among actors expected to play important roles in making hydrogen available for the sustainable energy system of the future.Hydrogen as a biofuel, that is, hydrogen produced from biomass in a sustainable way is recognised as an important component of the fuel market for the future low or non-carbon based energy systems. In this special issue, the main focus is on hydrogen produced from vegetable biomass by fermentation. The development of a two-stage bioprocess for the cost-effective and environmentally friendly production of pure hydrogen from multiple biomass feedstocks is elucidated by a collection of papers presenting preliminary results of Integrated Research Project HYVOLUTION supported by the 6th Framework Programme of the European Union. The attention is turned to:- the over-all concept and characteristics of the two-stage hydrogen fermentation process,- key technological issues of fermentative hydrogen production,- the availability of vegetable feedstocks including agricultural byproducts that suitable for fermentative processing,- prospects of societal integration and sustainability of the fermentative hydrogen production technology.Other papers included in this special issue are devoted to:- simultaneous production of hydrogen and methane by fermentation of lactose-containing feedstocks derived from byproducts of milk processing,- hydrogen gas generation from organic material by electrohydrogenesis, that is, a bioelectrochemical process performed in reactors known as a microbial electrolysis cells,- the ideas for Europe-wide effort on education of hydrogen users and training of skilled staff needed for facilitating the transition to the future hydrogen economy.     

Development of a unique topology for a hard-turning micro-scale machine tool

A micro-scale machine tool (mMT) topology is developed for turning hardened steel bearing components. The topology utilizes the principle of leverage to increase accuracy and stiffness and incorporates decoupling to reduce unwanted motion of the tool. Performance specifications required that the static stiffness is at least 10 N/μm and dynamic stiffness is at least 30 N/μm in all directions. The kinematics for the topology are developed to enable control over the position and orientation of the tool tip. The effect of the topology on rake angle is determined and the topology is adjusted so as to minimize the rake angle variation during the cut. Cutting tests are performed to determine cutting parameters for achieving a low surface roughness and to estimate the accuracy of the machine. Tests show that the hard-turning mMT can achieve surface roughness below 25 nm Ra, diametrical accuracy of 1 μm and peak-to-valley roundness deviation (RONt) below 0.35 μm.     

某石化企业粉体料仓爆燃事故原因分析

本文以某企业HDPE料仓的一次爆燃事故为案例,通过分析事故的成因,提供了调查料仓事故的思路及整改方案的确定方法.     

Mate replacement entails a fitness cost for a socially monogamous seabird

Studies of the selective advantages of divorce in socially monogamous bird species have unravelled extensive variation among different lineages with diverse ecologies. We quantified the reproductive correlates of mate retention, mate loss and divorce in a highly philopatric, colonially breeding biparental seabird, the Australasian gannet Morus serrator. Estimates of annual divorce rates varied between 40–43% for M. serrator and were high in comparison with both the closely related Morus bassanus and the range of divorce rates reported across monogamous avian breeding systems. Mate retention across seasons was related to consistently higher reproductive success compared with mate replacement, while divorce per se contributed significantly to lower reproductive output only in one of two breeding seasons. Prior reproductive success was not predictive of mate replacement overall or divorce in particular. These patterns are in accordance with the musical chairs hypothesis of adaptive divorce theory, which operates in systems characterised by asynchronous territorial establishment.     

Operational change as a profitable cleaner production tool for a brewery

The development and implementation of new procedures and operational changes in the production processes constitutes a powerful tool for the practical application of Cleaner Production in industries. In this work an operational change (new procedure) was developed for the elaboration of a type of beer which uses sugar as malt adjunct. The change consists in processing separately the three main components of the beer wort: malt extract, sugar and water, and use them properly in a different sequence than that used up to date in the traditional process. The new procedure was successfully assayed on industrial scale in Tínima brewery, located in Camagüey, Cuba, obtaining a good quality beer, technological and economical advantages with benefits for the environment, registering significant savings in energy (49%), sugar (4%), water (7%) and caustic soda (3%) consumption; and diminishing the surplus hot water (74%), waste generation (11%) and greenhouse gases emission (21%). Beer production capacity is increased also almost three times. With the application of the new technology to the Cuban beer type of 8 °P, it was achieved a total saving of US$ 481.83/1000 hL of beer produced.     

创造美好环境回报社会大众——中国光大国际有限公司工程总监张洪波专访录

作为一家专业环保投资企业,中国光大国际有限公司在短短一段时间内,在国内环保产业市场的一系列运作令业界刮目相看.本刊记者近期电话连线该公司工程总监张洪波.     

生物燃料发展前景乐观

2009年6月29日,丹麦外交部宣布在12月举行的“联合国气候变化大会”期间,各国政要将乘坐环保燃料交通工具穿梭于哥本哈根市内,其中一半车辆将使用基于秸杆的第二代生物乙醇驱动。据介绍,这次气候变化大会期间,丹麦准备了122辆基于生物能源、清洁柴油、混合动力和氢动力的环保车辆,其中60辆基于生物能源。生物燃料合作伙伴计划将负责为会议期间各国外长乘用的大部分车辆提供第二代生物乙醇……     

水热干化污泥处理技术的新空间

污泥是污水处理的产物.污水中约一半的污染物转移到了污泥当中,如果不进行妥善处理,将造成严重的二次污染.     

传统给水处理厂氯消毒模型的开发与应用

以建立给水处理过程的风险分析方法为目标,提出了适用于传统给水处理工艺的氯消毒概率机理模型.模型既考虑氯消毒过程中有机物、余氯、氨氮、溴离子之间化学反应,又考虑水厂混凝、沉淀和过滤工艺过程中的物理和生物作用.典型水厂的现场监测数据表明,该模型能够较好地模拟水厂中高锰酸盐指数、氨氮以及4种三卤甲烷的浓度概率分布.Monte Carlo模拟的结果表明,与我国城市供水水质标准相比,该水厂高锰酸盐指数和单种三卤甲烷的超标概率极低,但总三卤甲烷的超标概率略高,约为2.3%.     

Analysis of a laser process for permanently degrading a photo-activated adhesive joint

A pulsed, laser process has been developed to reduce the permanent strength of photo-activated adhesive joints prior to work-piece de-bonding. The objective of this investigation was to gain insight into the relationships between carbon black content of the adhesive, laser delivery mode, heat transfer, and adhesive degradation. To do so, a variety of experiments were performed to characterize process sensitivity, radiation absorption within the adhesive joint, and thermal decomposition of the adhesive. In addition, heat transfer analysis was conducted to predict adhesive temperatures during the process.The results of this investigation indicate that the strength diminishment of an adhesive joint occurs after it has absorbed a train of high power pulses in rapid succession. The vast majority of strength diminishment occurs over a very narrow time window and is highly correlated to the rapid emission of gray smoke/vapor from the adhesive joint. For this to occur, the adhesive must contain carbon black. It is also highly correlated to a rapid increase in temperatures throughout the adhesive matrix. Laser pulse parameters that do not lead to this rapid increase, will not initiate adhesive degradation.The inclusion of carbon black into the adhesive promotes heat absorption and increased temperatures in the adhesive joint. These temperatures are large enough to enable adhesive decomposition. But the time span over which this happens is too small for significant damage to occur. It is currently hypothesized that high temperatures local to the carbon black particles may be the source of adhesive degradation.     

When a year takes 18 months: evidence for a strong circannual clock in a shorebird

During the last three of 20 years kept as a pet, a red knot (Calidris canutus) went through two complete 'circannual' cycles of body mass and plumage. With a record cycle length of 18 months, this individual shorebird provides evidence for an exceptionally strong circannual clock system. The absence of synchronisation to outdoor but visible periodic cues suggests that the constant, socially-induced, day-night environment was of overriding importance. So far, only for songbirds is there firm experimental evidence that annual cycles are orchestrated by an endogenous circannual clock system. In constant environments the circannual cycles of these passerines tend to have periods that are shorter, rather than longer, than a year.     

污水处理厂沉淀池改进方案

根据某污水处理场沉淀池的COD和SS去除率较低的情况，文中着重探讨了问题的产生原因，并针对平流式沉淀池及斜管式沉淀池提出了相应的改进方案，实践证明改进后提高了COD和SS去除率30％，并明显降低了二级生物处理阶段的有机物负荷，节省了大量的暴气量通过改进达到了降低处理场其它环节的负荷和降低污水处理成本的目的。     

Action thresholds for processing cabbage,a short-term solution to a long-term problem

Action thresholds for management of lepidopteran pests in processing cabbage were developed and refined over a 4-year period. Since research data on the relationship of pest population density to economic loss was not available initially and treatment guidelines were required for a pest management demonstration program, the thresholds were initially based on the experience of an advisory committee including members from industry, extension and research faculty. These thresholds were revised annually, based on the comments of farmers using them, observations of the advisory committee and studies conducted for that purpose. Studies demonstrated considerable interaction between pest population density and other factors affecting yield. Future progress will require the development of a comprehensive economic threshold model, but in the interim the action thresholds provide most of the benefits expected from such a model.     

From a literature review to a conceptual framework for sustainable supply chain management

Academic and corporate interest in sustainable supply chain management has risen considerably in recent years. This can be seen by the number of papers published and in particular by journal special issues. To establish the field further, the purpose of this paper is twofold. First, it offers a literature review on sustainable supply chain management taking 191 papers published from 1994 to 2007 into account. Second, it offers a conceptual framework to summarize the research in this field comprising three parts. As starting point related triggers are identified. This allows putting forward two distinct strategies: (1) supplier management for risks and performance, and (2) supply chain management for sustainable products. It is evident that research is still dominated by green/environmental issues. Social aspects and also the integration of the three dimensions of sustainability are still rare.Both practitioners in companies and academics might find the review useful, as it outlines major lines of research in the field. Further, it discusses specific features of sustainable supply chains as well as limitations of existing research; this should stimulate further research.