Long-term stream invertebrate community alterations induced by the insecticide thiacloprid: effect concentrations and recovery dynamics

In pesticide risk assessment, effect concentrations and dynamics of long-term community-level effects caused by pulse exposures remain to be investigated. This is because long-term experiments are exceptionally rare, and most of the previously investigated communities had low proportions of sensitive long-living species. The aim of the present study was to investigate the effect of a single pulse contamination with the insecticide thiacloprid on invertebrates. We employed mesocosms designed to realistically mimic communities in small streams within the agricultural landscape. Specifically, the objectives were to (i) compare the community Lowest-Observed-Effect Concentration (LOEC) with organism-level median lethal concentrations (LC50), and (ii) to assess recovery dynamics with special focus on short- and long-living taxa. The contamination resulted in long-term alteration of the overall invertebrate community structure (7 months, until the end of the experiment). Long-term community LOEC was 3.2 microg/L (Redundancy Analysis), slightly below the acute LC50s known for sensitive invertebrates relevant to the mesocosm community. However, one species (stonefly Nemoura cinerea) was affected at the lowest tested concentration, 70 times below the lowest known LC50. Concerning time to recovery from the effect, we found that the duration depends on the life-cycle characteristics of species, but not on the toxicant concentration: short-living (mulivoltine) species recovered after 10 weeks following contamination, whereas long-living (uni- and semivoltine) species did not recover until the end of the experiment (7 months). The present example shows that concentrations of pesticides at which majority of the species is affected can be predicted by acute organism-level toxicity tests with sensitive species. However, tests with longer observation periods, as well as consideration of environmental factors and inter-taxon variability in sensitivity are required to predict effects on all species comprising a community. Realistic prediction of community recovery dynamics requires consideration of the species' life-cycle traits.     

先进制造与可持续城市发展

“工业4.0” [17,、18、 28]、“工业互联网”[15、16]和“中国制造”[3]是3个经济上高度相关的话题,它们都关乎当前国际价值网络的未来。实现“先进制造”的3个途径是针对即将到来的“第四次工业革命”而提出的,“第四次工业革命”的基础就是所有工业和服务的生产逐步数字化的过程[4]。这些长期规划和战略的制定基于现有的技术,即信息物理系统、物流网、分布式软件服务和云计算等。它们高度依赖于数字基础设施的水平和运作完好的物流系统,也对其所在的城市和地区产生影响。因此,对城市发展和先进制造之间的联系目前仍少有研究是个令人吃惊的现象,因为全球生产和物流会在相应制造战略的实施过程中引起重大变化。在工业领域内,与城市相关、可持续的经济活动将调整自身以适应新的地方、区域和全球ICT型的价值链和物流链。 　　由于全球范围内关于先进制造和城市发展之间的关系还没有充足的科学研究或实践经验,文章以探索的方式论述了一个学术和实践的新领域。首先,本文尝试建立一个假设,而不提出基于数据或案例的分析证据。我们在包含（1）高质量增长、（2）绿色城市经济和（3）可持续城市发展这3个概念的语境下讨论先进制造,这3个概念曾由德国国际发展公司（GIZ）做出过定义和释义[10、11]。绿色城市经济和大都市地区的可持续发展与增长方法的质量密切相关,在城市语境下,它们将涉及更广的范围并改变增长的质量。 　　高质量经济增长被视为高生产力、体面的就业的前提,后者进而对根除贫困和促进公平的社会经济发展起到了非常关键的作用[10]。GIZ从以下几方面定义了高质量增长。 　　精明增长：通过鼓励知识和创新型的经济发展提高生产力和竞争力。 　　可持续增长：使一代人的经济发展不会对后代造成负担的环境可持续性,以及向绿色经济的转型。 　　包容性/共享性增长：社会的所有部门都高产地参与到经济进程中。 　　弹性增长：减少经济波动,减缓经济发展受经济危机的危害或影响。 　　整合增长：改善商品和服务跨国流通的框架条件。 　　增长治理：建立强力机制和透明、参与式决策过程。 　　这几方面构成了颇有价值的框架,本文也将以之为分析的指南。在精明增长方面,很显然,对先进制造概念的理解有助于理解精明生产环境系统的概念。 　　绿色城市经济这个概念帮助城市利益相关者在城市语境中理解国际上和国内关于绿色经济的争论。这个概念基于这样的假设：在世界绝大部分已经是城市的未来,城市应该成为绿色经济转型的先锋。GIZ所定义的绿色城市经济的关键因素包括[2]： 　　包容的经济增长：“未来的发展战略必须不再只专注于量化的目标。相反,必须要有能造福所有人口组成部分的质的增长。尤其在城市中,贫富差距日益扩大,还有越来越多的人群不能充分参与社会和经济活动”[2]。 　　环境兼容性：“经济增长脱离资源消耗和温室气体排放是非常关键的一点。这是可以通过鼓励创新和环境无害的技术来实现的。由于其人口密度高,城市往往可以提供建立高效基础设施网络的机遇” [2]。 　　减少贫困：“包容、生态无害的增长必然要走向减少贫困和为人们在生活中提供机会。这需要产生更多的收入机会,尤其要为低收入人群和城市非正式产业提供收入机会,改善贫民和非正式住区居民获得基本市政服务的情况” [2]。 　　大都市地区的可持续发展是应对城市群和大都市地区需求,并努力提升其治理结构的的途径。GIZ认为有4个多部门的优先点是相关的[2]： 　　大都市地区作为创新产业地区：“大都市为地方、国家和全球商业的商品和信息的交流提供了场所。他们吸引知识型公司,并推进和落实可促进可持续经济活动的新想法。但是,为了实现这一点,必须要建立适当的框架” [2]。 　　大都市地区作为包容的劳动力市场和住宅中心：“大都市地区以其经济增长可创造广泛的服务类工作岗位,贫困人群也可从中受益[2]。” 　　大都市地区作为“密集纽带”网络：大都市地区把大量的人口、生产和消费集中在一个区域,它要消耗巨量的能源和自然资源。但是由于大都市地区存在着紧密交织的地理连接和部门连接,还是有很好的机会以提高其物质和能量循环的效率的” [2]。 　　大都市地区作为治理体系：“城市群需要新的治理结构以组织和控制它们所面临的多部门的挑战……”[2] 　　上述的3个途径：高质量增长、绿色城市经济和可持续城市发展,有不少相互重合和联系之处。高质量增长关注总体上的经济发展,而绿色城市经济和大都市地区可持续发展的概念把增长质量转化到城市发展的语境中。因此,我们取增长质量这个方法来作为分析的基础。     

Enzyme Toolbox: Novel Enantiocomplementary Imine Reductases

Reducing reactions are among the most useful transformations for the generation of chiral compounds in the fine‐chemical industry. Because of their exquisite selectivities, enzymatic approaches have emerged as the method of choice for the reduction of C?O and activated C?C bonds. However, stereoselective enzymatic reduction of C?N bonds is still in its infancy—it was only recently described after the discovery of enzymes capable of imine reduction. In our work, we increased the spectrum of imine‐reducing enzymes by database analysis. By combining the currently available knowledge about the function of imine reductases with the experimentally uncharacterized diversity stored in protein sequence databases, three novel imine reductases with complementary enantiopreference were identified along with amino acids important for catalysis. Furthermore, their reducing capability was demonstrated by the reduction of the pharmaceutically relevant prochiral imine 2‐methylpyrroline. These novel enzymes exhibited comparable to higher catalytic efficiencies than previously described enzymes, and their biosynthetic potential is highlighted by the full conversion of 2‐methylpyrroline in whole cells with excellent selectivities.     

Laboratory test reactor for the investigation of liquid reducing agents in the selective catalytic reduction of NOx

A test reactor was designed and built for investigating liquid reducing agents in the selective catalytic reduction (SCR) process in the laboratory. The design of the experimental setup is described in detail and its performance was evaluated. Using a glass nebulizer, liquid reducing agents were sprayed directly onto a catalyst positioned in a heated glass reactor with a length of 250 mm and an internal diameter of 20.4 mm or 40 mm. Model exhaust gases were mixed from individual gas components and were heated up to 450?°C in a heat exchanger before entering the reactor. The off-gas was analyzed using two complimentary techniques, a multi-component online FTIR gas analysis and a liquid quench gas absorption setup, to detect higher molecular compounds and aerosols. Due to the versatility of construction, processes not related to SCR, but involving three-phase reactions with gases, liquids and a catalyst, can also be investigated.     

Resonance enhanced dynamic light scattering

We present a novel light scattering setup that enables probing of dynamics near solid surfaces. An evanescent wave generated by a surface plasmon resonance in a metal layer is the incident light field in the dynamic light scattering experiment. The combination of surface plasmon resonance spectroscopy and dynamic light scattering leads to a spatiotemporal resolution extending a few hundred nanometers from the surface and from microseconds to seconds. The comparison with evanescent wave dynamic light scattering identifies the advantages of the presented technique, e.g., surface monitoring, use of metal surfaces, and biorelevant systems. For both evanescent wave geometries, we define the scattering wave vector necessary for the analysis of the experimental relaxation functions.     

堆肥过程中产生的尾气

堆肥过程中产生大量的臭气,考察这些臭气的组成、含量对处理城市生活垃圾堆肥有重大意义。实验采用气相色谱质谱联用仪（GCMS）对收集的堆肥尾气进行检测,测得21种气体,其中含量较大的气体为NH3和H2S等。     

High-resolution microstructural investigations of interfaces between light metal alloy substrates and cold gas-sprayed coatings

Interfaces between light metal alloys, aluminum AA7022, and magnesium AZ91, and optimized cold gassprayed zinc-based coatings are characterized. The analyses include scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM). Investigations by SEM show a seam with intensive mixing of the substrate and coating material, which is indicated by different values of gray due to element contrast. In energy-dispersive spectroscopy analyses, increased zinc concentrations compared with the substrate material are detected in <1 μm thick vortexes inside the seam. The TEM investigations prove that these areas consist of a homogeneous solid solution and submicron-sized or nanosized intermetallic phases with different concentrations of aluminum, zinc, and magnesium. Because diffusion processes cannot result in the observed microstructure. local melting followed by precipitation of intermetallic phases is concluded as the consequence of the intensive mechanical interaction at the substrate-coating interface during particle impact during the cold gas spraying of zinc on magnesium or aluminum substrates. The original version of this paper was published in the CD ROM Thermal Spray Commects: Explore Its Surfacing Potential, International Thermal Spray Conference, sponsored by DVS, ASM International, and HW International Institute of Welding, Basel, Switzerland, May 2–4, 2005, DVS-Verlag GmbH, Düsseldorf, Germany.     

Development and trends in HVOF spraying technology

Three actual trends in development of HVOF spraying technology are described and discussed. The trends concern application fields as well as gun and feedstock characteristics. At the example of demountable draw bars it is shown that HVOF sprayed cermet coatings are capable to protect light weight material components subject to dynamical load against wear without detraction of fatigue strength. Personnel and production time savings can be exploited. High deposition efficiency at considerable powder feed rate, high density and negligible oxygen content in corrosion protective iron or nickel based coatings is achieved for spraying with newly developed HVOF guns operating at increased combustion chamber pressures. Also spraying of highly reactive materials like titanium under atmospheric conditions becomes feasible. A major obstacle for industrial use of respective coatings is the lack of adapted characterisation methods that permit to ascertain corrosion protective function. Ultrafine powder feedstock is used in order to reduce overall costs of wear protective cermet coatings due to the possibility to finish coatings by comparatively cheap belt grinding. However, it is shown that the replacement of coatings produced with conventional powder size fractions requires careful consideration of the particular tribological system. While cermet coatings produced with ultrafine powders outperform conventional coatings for sliding wear conditions, their capability to withstand dry abrasive wear stress is poor. The benefits concerning coating production costs may be outweighed by significantly decreased component life time.     

Stability of foams containing proteins, fat particles and nonionic surfactants

The foamability of aqueous suspensions of proteins and fat particles containing different nonionic surfactants relevant to ice cream mix, through which air is continuously bubbled in a foam column, is investigated in terms of the growth of the foam until steady state is reached. Less water-soluble but more oil-soluble Spans 20, 80 and 85 (monolaurate, monooleate and trioleate of Sorbitan) reduced significantly the steady-state foam height and hence the foamability by enhancement of bubble coalescence. In contrast, highly water-soluble Tweens 20 and 80 increased only slightly the steady-state height of the foams as compared to that obtained using surfactant-free suspension. However, moderately water- and oil-soluble Tween 85 (polyoxyethylene sorbitan trioleate) decreased the foamability more significantly than the Spans. The bubbles are found to be small and coalesce relatively fast at the bulk air interface. The bridging of the fat particles by the three oleates could weaken the protein and fat network thereby reducing the elasticity of the air-aqueous phase interface. This is corroborated by the lowest interfacial elasticity measured using a biconical disc oscillatory rheometer. The stability of the foams formed is also determined by measuring the decrease in foam height and increase in mean bubble diameter with time after stopping the air flow. The results are found to verify a published theoretical model, which enabled to determine the parameters controlling foam stability. The Spans reduced the foam stability as the bubbles coalesced rapidly with bulk air. In contrast, the Tweens increased the foam stability as the bubbles coalesced very slowly. The increase of foam stability by Tween 85 under quiescent conditions is consistent with the measured high interfacial shear viscosity.     

Influence of the oxidation state of phosphorus on the decomposition and fire behaviour of flame-retarded epoxy resin composites

A systematic and comparative evaluation of the pyrolysis of halogen-free flame-retarded epoxy resins containing phosphine oxide, phosphinate, phosphonate, and phosphate (phosphorus contents around 2.6 wt.%) and the fire behaviour of their carbon fibre composites is presented. Decomposition pathways are proposed based on the thermal analysis (TG), TG coupled with evolved gas analysis (TG-FTIR), kinetics and analysis of the residue with FTIR and XPS. All organophosphorus-modified hardeners containing phenoxy groups lead to a reduced decomposition temperature and mass loss step for the main decomposition of the cured epoxy resin. With increasing oxidation state of the phosphorus the thermally stable residue increases, whereas the release of phosphorus-containing volatiles decreases. The flammability of the composites was investigated with LOI and UL 94 and the fire behaviour for forced-flaming conditions with cone calorimeter tests performed using different irradiations. The flame retardancy mechanisms are discussed. With increasing oxidation state of the phosphorus additional charring is observed, whereas the flame inhibition, which plays the more important role for the performance of the composites, decreases. The processing and the mechanical performance (delamination resistance, flexural properties and interlaminar bonding strength) of the fibre-reinforced composites containing phosphorus were maintained at a high level and, in some cases, even improved. The potential for optimising flame retardancy while maintaining mechanical properties is highlighted in this study.