Effect of intermittent aeration on the treatment performance in a submerged membrane bioreactor

In order to improve removal for nitrogen in a pilot-scale submerged membrane bioreactor (SMBR), intermittent aeration was conducted, and the effect on the treatment performance under four kinds of operation condition (run 1, continuous aeration; run 2, 60/60 min aeration on/off time; run 3, 60/90 min aeration on/off time; run 4, 60/75 min aeration on/off time) was evaluated. The results showed that depending on the specific on/off of the aeration time ratio, removal efficiency of nitrogen could be improved significantly, and the removal rates of total nitrogen (TN) under different operation conditions were 28.0%, 59.5%, 66.8% and 70.7%, respectively. There were no obvious differences for removal rates for COD_Cr and ammonia among different operation conditions. In general, intermittent aeration could be used as a feasible way to improve treatment performance for nitrogen in the SMBR.     

The impact of warrants introduction: Sign effect or magnitude effect?

The data of warrants underlying stocks was selected for the sample period from August, 2005 to December, 2009. These data the authors collected did not include the announcement date of reform of non-tradable underlying shares, and was available from Shanghai and Shenzhen stock exchanges. The event study method is employed to test the magnitude effect based on the Wild bootstrap, which is performed on the abnormal return, the cumulative abnormal return, and the standardized cumulative abnormal return. Empirical results show no evidence of magnitude effect but sign effect after warrants introduction. The authors argue that this phenomenon is caused by the migration of radical agents from stock market to warrant market.     

Viability criteria for differential inclusions

A method of verifying the viability criterion at a given point for a region with nonsmooth boundary, which is expressed by a quasidifferentiabl function, under a differential inclusion which is a convex hull of finitely many functions, is proposed. By this method, determining the viability is transformed into solving a number of systems of linear inequalities, or equivalently solving a number of linear programming problems. For the other differential inclusion, called the generalized convex process, it is shown that viability condition holds for a polytope if and only if it holds at all of its vertices. This result is an extension of corresponding one for a linear control system.     

State transfer control of quantum systems on the Bloch sphere

The state transfer under control fields is analyzed based on the Bloch sphere representation of a single qubit. In order to achieve the target from an arbitrary initial state to a target state, the conditions that parameters should satisfy are deduced separately in two different requirements: One is in the case of the rotation angle around the x-axis being fixed and another is in the situation with a given evolution time. Several typical states trajectories are demonstrated by numerical simulations on the Bloch sphere. The relations between parameters and the trajectories are analyzed.     

A Systems Theoretical Approach to Interoperability of Information

A rapid process of hybridisation of man and technology, organisation and technology and society and technology is currently sweeping the world. This process requires a way of (scientific) thinking that takes hybrid systems as the starting point. Such an approach makes it increasingly important for hybrid systems to be interlinked, enabling them to exchange and share information through these links. This linking of (hybrid) systems to enable them to exchange and share information can also be denoted as the realisation of interoperability between (hybrid) systems. Five principles from Luhmann’s systems theory can help us understand interoperability. Interoperability enables (hybrid) systems to join random coalitions and networks. The network centric warfare concept is currently the basis for international efforts aimed at the development and application of interoperability that would enable armed forces to act effectively and efficiently. This paper demonstrates what we can learn from Luhmann’s system’s theory.     

某砖混结构阳台挑梁加固方法及案例分析

针对某多层砖混结构阳台挑梁混凝土强度偏低,通过几种加固方案的比较采用增加钢拉杆和粘贴碳纤维布的方法进行加固处理,加固后进行荷载试验,试验表明构件满足承载力使用要求,投入使用多年,使用状况良好,表明所采用的加固方案有效,可供类似工程加固设计参考.     

程控交换机的日常维护与管理

文章通过铁通公司使用的程控交换机出现的常见故障,提出了如何维护和管理等一系列措施,以期帮助程控人员解决一些疑难问题。     

Vegetation effects on mean daily maximum and minimum surface air temperatures over China

Changes in the daily maximum (Tmax) and minimum (Tmin) surface air temperatures and the associated temperature extremes have severe consequences on human society and the natural environment. In this study, we assess vegetation effects on mean Tmax and Tmin over China by computing a vegetation feedback parameter using the satellite-sensed Normalized Difference Vegetation Index (NDVI) and observed temperatures for the period 1982–2002. In all seasons, vegetation exerts a much stronger forcing on Tmax than on Tmin, and thus has a substantial effect on the diurnal temperature range (DTR) over China. Significant positive feedbacks on Tmax and the DTR occupy many areas of China with the feedback parameters exceeding 1°C (0.1 NDVI)–1, while significant negative effects only appear over the summertime climatic and ecological transition zone of northern China and some other isolated areas. Also, the vegetation feedbacks are found to vary with season. In areas where significant feedbacks occur, vegetation contributes to typically 10%–30% of the total variances in Tmax, Tmin, and the DTR. These findings suggest that vegetation memory offers the potential for improving monthly-to-seasonal forecasting of Tmax and Tmin, and the associated temperature extremes over China. Meanwhile, the limitations and uncertainties of the study should be recognized.     

Removable ears of 1-extendable graphs

<正> Carvalho,Lucchesi and Murty proved that any 1-extendable graph G different from K_2and C_(2n)has at least Δ(G)edge-disjoint removable ears,and any brick G distinct from K_4 and■hasat least Δ(G)-2 removable edges,where Δ(G)denotes the maximum degree of G.In this paper,weimprove the lower bounds for numbers of removable ears and removable edges of 1-extendable graphs.It is proved that any 1-extendable graph G different from K_2 and C_(2n)has at least χ′(G)edge-disjointremovable ears,and any brick G distinct from K_4 and■has at least χ′(G)-2 removable edges,whereχ′(G)denotes the edge-chromatic number of G.     

Exploring an Explicit Use of the Concept of Sustainability in Transport Planning

The aim of this paper is to explore an explicit use of the concept of sustainability within transport planning. This paper analyses the concept of sustainability based on a practical approach for a sustainable development of Nordhavn, an area of Copenhagen, exemplifying a complex planning problem. An exploration of the application of the concept of sustainability is carried out using elements of Soft Systems Methodology (SSM). This approach indicates a need to separate the use of sustainability considerations regarding the transport planning ‘process’ from the transport planning ‘results’. The two approaches are related to the planning levels presented by Ulrich (Syst Prac 1(4):415–428, 1988). It was chosen to focus on the understanding of a sustainable transport planning process. This focus is addressed by four stakeholder groups interviewed based on the ‘ought to’ mode of Critical Systems Heuristics (CSH). Finally an outline of some of the factors of a sustainable transport planning process is proposed.