黄河水中沉积物与锌、镉液-固界面的作用

研究了黄河水中沉积物与重金属污染物Zn^2 、Cd^ 的离子交换吸附作用。结果表明,Zn^2 、Cd^2 在黄河水中主要以M（OH）^ 的形式与沉积物进行－价阳离子交换反应;在天然黄河水pH范围内,Zn^2 、Cd^2 的离子交换率都大于70％;随温度升高,Zn^2 、Cd^2 与沉积物的交换率增加,E-pH曲线向pH值减小的方向位移。     

Optimum Design for Emergency Stop Button on Robot Teach Pendants

This study deals with designing robot teach pendants for industrial robots. The emergency stop button on robot teach pendants is the primary safety device for industrial robots. Recommendations for the design of the emergency stop button were proposed based on experimental evaluations. Human performance was measured by the reaction time necessary to press the button on a pendant. The variation factors were randomly combined by seven button locations and three different button sizes. The results indicated that the shortest reaction time was obtained for the 38-mm button located on the left and left-down of the seven button positions on the pendant.     

Reprint of: ‘Heimat’ as a boundary object? Exploring the potentialities of a boundary object to instigate productive science-stakeholder interaction in North Frisia (Germany)

The North Frisian Wadden Sea represents one of the best researched natural regions in the world. Since the end of the 1980s, scientific research has been carried out to scientifically study, analyse and assess this intertidal coastal zone under the conceptual umbrella of ecosystem research. The outcome of this assessment materialised in the establishment of the Nationalpark Schleswig-Holsteinisches Wattenmeer. Its implementation caused considerable conflicts between coastal inhabitants, national park authorities and government officials. Arguments in these disputes revolved around the validity and relevance of scientific knowledge generated to assess and legitimately protect the tidelands and areas of the Waddensea. In summary, the whole implementation process was locally perceived as a politically endorsed top-down enforcement strategy only allowing scientific knowledge for decision-making purposes while local concerns and ‘knowledges’ were not included. To learn from these developments and past mistakes, we compare concepts of co-management, boundary work and boundary objects (BO) to theoretically and methodologically explore their potentials to generate shared meanings and instigate communication in the context of future managing purposes. Against this theoretical background, we propose the empirical show-case example of the German concept of ‘Heimat’ as a BO to assess its applicability to study place-based meanings and to illustrate it as a practice-oriented point of entry to initiate productive science-stakeholder interaction (SSI) in managing the North Frisian Wadden Sea.     

The Application of Multiple Evaluating Methods on the Comprehensive Evaluation of Urban-rural Interaction and Conjunctional Development of China

Abstract

Urban-rural interaction and conjunctional development is the effective way of harmonizing urban-rural relationship and promoting urban-rural development. However, there are differences in the level of urban-rural interaction and conjunctional development of China. How to measure and reflect the difference properly is a decision-making foundation for optimizing urban-rural development of different regions. The paper employs multiple methods to evaluate and order the urban-rural interaction and conjunctional development of 31 provinces (municipalities) in China. Kendall's W consistency coefficient is employed to give a consistent test for the evaluation result series, and the results of multiple methods are aggregated as the final evaluation value. The results reflect the level of regional urban-rural interaction and conjunctional development in China.     

Introduction: The dark and light sides of organizational citizenship behavior

This is an introduction to a point/counterpoint exchange in Journal of Organizational Behavior on the negative versus positive sides of organizational citizenship behavior (OCB). Such behaviors go beyond the core tasks that individuals do on the job and are generally considered positive contributions that support organizations. Bolino, Klotz, Turnley, and Harvey cover the dark (negative) side of OCB, arguing that it can be performed for self‐serving motives and that it can have detrimental effects. They discuss the costs of performing OCB to the individuals who perform it, and potential negative consequences for organizations. Conversely, Spitzmuller and Van Dyne cover the light (positive) side, focusing on OCB as forms of either proactive or reactive helping behavior. Proactive helping is motivated by internal needs with the individual seeking out opportunities to engage in OCB. Reactive helping is an altruistic response to a perceived need by a colleague or the organization itself. Taken together, these two papers provide a comprehensive overview of the complex effects of OCB on actors who perform it and targets who receive it. Copyright © 2012 John Wiley & Sons, Ltd.     

3D simulation of hydrogen ignition in a rapid compression machine

Low-temperature (at T < 900–950 K) ignition delays of hydrogen–air mixtures are mainly measured in rapid compression machines (RCM). This communication is aimed at numerical simulation of ignition delays of hydrogen–air mixtures in the RCM by means of a coupled three-dimensional (3D) Unsteady Reynolds-Averaged Navier–Stokes (URANS) – Particle Method (PM) simulation of RCM operation capable of catching turbulence–chemistry interaction. The study indicates that the time history of piston motion in an RCM affects the final state of a test mixture at the end of compression stroke and therefore influences the phenomena relevant to test mixture ignition. More specifically, the calculations show that different laws of piston motion at a fixed average piston velocity (i.e., fixed piston displacement and fixed compression time) and fixed compression ratio result in different evolution of mean pressure, temperature and velocity fields in the RCM test section leading to different ignition behavior. The reasons for the arising differences lie in the fact that the local instantaneous piston velocity determines the roll-up vortex structure, strength and turbulence dissipation in it, heat transfer in test-section walls, and mass leakage through piston rings.     

生物炭吸附雨水径流难生物降解有机氮效能及机制

有机氮（ON）在雨水径流氮素污染中起关键作用,但多数研究只关注可生物降解有机氮的生物转化去除,忽略了占比较高的难生物降解有机氮.以生物炭作为吸附剂,探究其对雨水径流典型难生物降解有机氮（吲哚）的吸附效能及机制.结果表明,原始生物炭对吲哚有较高的单位吸附量（45 mg·g^-1）,生物炭投加浓度为0.4 g·L^-1时其表面平均吸附位点利用度最高.H₂O₂和NaOH改性生物炭对吲哚的吸附量是原始生物炭的1.3倍和1.6倍,吸附机制包括疏水相互作用、氢键和π-π电子供体-受体（π-π EDA）作用,以疏水相互作用为主,其中H₂O₂改性通过增加生物炭表面含氧官能团来加强氢键和π-π EDA作用,而NaOH改性生物炭通过大幅提高生物炭比表面积来加强疏水相互作用,故NaOH改性吸附效果更优.综上,生物炭对难生物降解有机氮具有较强去除作用,通过NaOH改性还能大幅提高效率,故在雨水径流氮素污染较高的地区把NaOH改性生物炭作为生物滞留池中的填料有着极大的应用潜力.     

基于“双循环”系统的钢桥梁施工项目安全问题分析

为提升钢桥梁施工项目安全管理水平,本文采用人员访谈、问卷调研及逻辑分析的方法,对钢桥梁施工项目关键问题进行界定,并建立施工项目关键问题的双循环系统;在此基础上,从施工项目内循环、外循环方面对项目主体系统提出组合干预策略。研究表明:施工项目主体系统主要受内外双循环系统的要素作用,其中内循环分别为生产系统、技术系统、配置系统、安监系统,具有相互作用机制,外循环系统通过系统管理合作面、服务监督面、沟通协调面3个工作面作用,相互之间具有17个作用要素。     

Indirect interactions between invasive and native plants via pollinators

In generalised pollination systems, the presence of alien plant species may change the foraging behaviour of pollinators on native plant species, which could result in reduced reproductive success of native plant species. We tested this idea of indirect interactions on a small spatial and temporal scale in a field study in Mauritius, where the invasive strawberry guava, Psidium cattleianum, provides additional floral resources for insect pollinators. We predicted that the presence of flowering guava would indirectly and negatively affect the reproductive success of the endemic plant Bertiera zaluzania, which has similar flowers, by diverting shared pollinators. We removed P. cattleianum flowers within a 5-m radius from around half the B. zaluzania target plants (treatment) and left P. cattleianum flowers intact around the other half (control). By far, the most abundant and shared pollinator was the introduced honey bee, Apis mellifera, but its visitation rates to treatment and control plants were similar. Likewise, fruit and seed set and fruit size and weight of B. zaluzania were not influenced by the presence of P. cattleianum flowers. Although other studies have shown small-scale effects of alien plant species on neighbouring natives, we found no evidence for such negative indirect interactions in our system. The dominance of introduced, established A. mellifera indicates their replacement of native insect flower visitors and their function as pollinators of native plant species. However, the pollination effectiveness of A. mellifera in comparison to native pollinators is unknown. Christine B. Müller, deceased 7 March 2008.     

荒漠化对全球气候变化的响应

荒漠化对气候的影响是通过干扰干旱地区的地 -空能量交换平衡机制而产生效力的。旱地对全球温室气体的贡献率估计在 5 %～ 10 % ,其中旱地退化的贡献率小于 5 %。温室气体的积累将导致 2 1世纪全球升温 1～5℃。利用NOAA -AVHRR卫星影像监测到 ,Sahara半干旱区边缘的植被变化与年降雨变率有关。 1980～ 1990的十年间 ,Sahara地区 2 0 0mm年降雨量的南界有较大的波动。