气幕隔尘法在电炉屋顶烟罩排烟系统中的应用分析

通常电炉加料和出钢时的烟气均通过屋顶烟罩捕集,但使用效果不够理想。为提高屋顶烟罩的捕集效率,节省大规模排烟量和风机能耗,提出更加经济的气幕隔尘法用于辅助电炉屋顶烟罩排烟。即在屋顶烟罩底部形成一个无形透明的屏障,以阻止电炉加料或出钢时的向上烟气不因车间横向气流的干扰而向屋顶烟罩外扩散。结合工程项目分析了气幕隔尘新技术的应用前景。     

Selling displaced people? A multi‐method study of the public communication strategies of international refugee organisations

The world has seen a major increase in forced displacement since 2011. As a growing number of states implement restrictive refugee policies, public communication has become essential for refugee organisations. This study analysed, therefore, three international refugee organisations’ discursive strategies towards the recent Syrian crisis, as well as their production and the social context. A critical discourse analysis of international press releases (N=122) and six semi‐structured interviews with press and regional officers revealed that the observed actors largely dehumanise displaced people and subordinate them to the ‘Western self’ and state interests; displaced people hardly ever acquire their own voice. The study found that the medium characteristics of press releases and the importance of media attention result in a depersonalising humanitarian discourse. In addition, there were indications of a post‐humanitarian discourse that reproduced the humanitarian sector's ‘marketisation’. Finally, the examined organisations use the political realist cross‐issue persuasion strategy, displaying displaced people as resettlement objects.     

Investigation on the degradation and opening behavior of knife blade burst disks

Burst disks are often used as the highest level of defense against over pressure. 36 knife blade burst disks were spent to test their steadfastness and reliability. Half of the burst disks were subjected to stress similar to normal use in a plant. They showed no sign of degradation compared to the unstressed disks. However many disks failed to burst at the specified pressure and none opened with the specified cross section. These parameters are essential for dimensioning pressure relief equipment.     

Strategic alignment with organizational priorities and work engagement: A multi‐wave analysis

This study advances the limited research on work alignment and work engagement by investigating how perceived alignment of job tasks and organizational strategic priorities (strategic alignment) influences work engagement. Measures of job control and work social support were also included to enable comparisons between strategic alignment and other well‐established job resources. A total of 1011 employees of an Australian state police service responded to three electronic, self‐report surveys. A reciprocal model was assessed over three waves of data, with varying time lags: 18 (Time 1 to Time 2), 12 (Time 2 to Time 3), and 30 months (Time 1 to Time 3). Longitudinal, reciprocal relationships were observed for work engagement and job control, strategic alignment, and colleague support. Work engagement also predicted supervisor support over time (reverse effect). This study demonstrated that, in addition to job resources, perceived alignment of job tasks and organizational priorities plays an important role in maintaining high levels of work engagement over time. Copyright © 2013 John Wiley & Sons, Ltd.     

Turbulent velocity profile in fully-developed open channel flows

The determination of velocity profile in turbulent narrow open channels is a difficult task due to the significant effects of the anisotropic turbulence that involve the Prandtl’s second type of secondary flow occurring in the cross section. With these currents the maximum velocity appears below the free surface that is called dip phenomenon. The well-known logarithmic law describes the velocity distribution in the inner region of the turbulent boundary layer but it is not adapted to define the velocity profile in the outer region of narrow channels. This paper relies on an analysis of the Navier–Stokes equations and yields a new formulation of the vertical velocity profile in the center region of steady, fully developed turbulent flows in open channels. This formulation is able to predict time averaged primary velocity in the outer region of the turbulent boundary layer for both narrow and wide open channels. The proposed law is based on the knowledge of the aspect ratio and involves a parameter C_Ar depending on the position of the maximum velocity (ξ_dip). ξ_dip may be derived, either from measurements or from an empirical equation given in this paper. A wide range of longitudinal velocity profile data for narrow open channels has been used for validating the model. The agreement between the measured and the computed velocities is rather good, despite the simplification used.     

地下复杂组合受限空间火灾分区现象与初期模式实验研究

主要介绍地下狭长与组合受限空间油料介质火灾分区现象、初期火灾主要模式模拟实验研究结果与讨论;地下组合受限空间火灾呈现出特殊的分区现象。一般可分为燃烧区、新鲜空气补充区、烟气流区、过渡区和火焰后面的“惰化区”五区。有上下两层的地下复杂组合受限空间可分为燃烧区、烟气流区、新鲜空气补充区和“惰化区”4区。地下受限空间(包括组合受限空间、容积式受限空间和狭长受限空间)密闭条件下火灾初期模式主要有：爆炸、爆炸减弱、爆炸增强、燃烧、爆燃向爆轰发展。地下复杂组合受限空间下部与下部狭长受限空间分别全开口条件下着火后火灾主要模式为爆炸、燃烧、爆炸后持续燃烧、爆炸后短时燃烧、爆炸后发展为出口外爆炸;爆炸又可分为爆炸强度逐步加强、爆炸由爆燃发展为爆轰、爆炸强度逐步减弱。     

壳聚糖吸附重金属离子的研究进展

综述了,我国近几年来壳聚糖处理含重金属离子废水的研究进展。壳聚糖及其改性产品的吸附性能主要体现在对各种金属离子的吸附上,为了有选择性地吸附某种或某些金属离子,人们通过修饰、交联、接枝等方法对壳聚糖进行了各种改性研究。     

DPIV图象的诊断方法研究

数字粒子图象测速技术已在国内外各个实验方向得到广泛的重视和应用,但应用的关键就在于它的诊断方法。本文介绍了ＤＰＩＶ图象诊断方法中最常用的互相关法。并发展了传统互相关算法,然后对互相关法进行平移和旋转的标定,以确定其可行性和可靠性。最后应用于重力作用下水射流的实验。     

When to be neighbourly: differential agonistic responses in the lizard Platysaurus broadleyi

Differential treatment of neighbours and strangers (the dear enemy phenomenon) can reduce the costly effects of territory defence. Individual recognition, and by extension the dear enemy phenomenon, was examined in the cordylid lizard Platysaurus broadleyi. I had no knowledge of familiarity between individuals and therefore classed intruders as neighbours or non-neighbours and tested for differences in agonistic response consistent with the dear enemy phenomenon. In the dear enemy phenomenon, levels of aggression are inversely related to degree of familiarity such that residents are more tolerant of immediate neighbours than distant territory holders. A manipulative field experiment in conjunction with field observations of known territory holders revealed that resident males allowed neighbours to approach more closely than non-neighbours before challenging them, residents were more aggressive towards non-neighbours than neighbours, contests between neighbours were significantly longer than between neighbours and non-neighbours and contests between residents and non-neighbours were likely to result in a win for the resident, while neighbours frequently drew contests. These results suggest a level of recognition consistent with the dear enemy phenomenon. I also manipulated front leg colour to test the hypothesis that it alone could serve as a cue for individual recognition. I found no support for this hypothesis and suggest that multiple cues operate in individual recognition. Received: 4 March 1999 / Received in revised form: 11 April 1999 / Accepted: 19 April 1999     

河西走廊1994－04－08浮尘暴·黄沙的气象特征和大气气溶胶测定

报道１９９４－０４－０７—１９９４－０４－０８河西走廊形成浮尘暴·黄沙天气过程、气象观测和大气总悬浮微粒（ＴＳＰ）测定结果,说明我国西北地区发生的浮尘暴·黄沙天气的气象及大气气溶胶特点。嘉峪关和酒泉一带是这次黄沙的中心;酒泉等地的ＴＳＰ浓度高达３８．００ｍｇ／ｍ３,室内ＴＳＰ浓度高达８．６３ｍｇ／ｍ３,自然降尘浓度达２９６．２２ｔ／（ｋｍ２·月）;黄沙云高约２０００—３０００ｍ;主要组成元素Ｓｔ、Ａｌ、Ｃａ、Ｆｅ、Ｍｇ、Ｍｎ和Ｔｉ等含量上升;黄沙沿嘉峪关、酒泉、金昌、兰州和北京渐次减少;１９９４－０４－１１的２：００在甘肃省大部分地区出现了哈布（Ｈａｂｏｏｂ）现象。建议今后对尘暴·黄沙的研究还应测定黄沙气溶胶浓度、粒度分布和不同粒度微粒的化学组成,测定雨土、降水、降尘和气温的变化。