上海市环境空气臭氧浓度时空分布特征的调查

上海市机动车保有量逐渐增加,为监测机动车尾气造成的氧化型光化学烟雾的污染,采用被动扩散管的监测方法在上海市大面积布设点位,经连续１４个月的监测,得出上海市环境空气中臭氧（Ｏ３）浓度的时分布特征。     

内旋流流化床埋管传热研究

垃圾焚烧系统中,内旋流流化床存在不同布风速度的移动区、流动区和换热区,处于换热区的埋管的对流换热系数受附近流动区气流参数的影响,其变化趋势及数值大小与普通鼓泡型流化床之间有明显不同:最大的对流换热系数明显高于鼓泡床;换热区尚未流化时,对流换热系数己经大幅提高;整条换热曲线的变化比较平缓,易于流化床浓相床内换热。      

A new shock tube configuration for studying dust-lifting during the initiation of a coal dust explosion

The traditional defence against propagating coal dust explosions is the application of dry stone dust. This proven and effective safety measure is strictly regulated based on extensive international experience. While new products, such as foamed stone dust, offer significant practical benefits, no benchmark tests currently exist to certify their dust lifting performance in comparison to dry stone dust. This paper reviews the coal dust explosion mechanism, and argues that benchmark testing should focus on dust lifting during the initial development of the explosion, prior to arrival of the flame. In a practical context, this requires the generation of shock waves with Mach numbers ranging from 1.05 to 1.4, and test times of the order of 10's to 100's of milliseconds. These proposed test times are significantly longer than previous laboratory studies, however, for certification purposes, it is argued that the dust lifting behaviour should be examined over the full timescales of an actual explosion scenario. These conditions can be accurately targeted using a shock tube at length scales of approximately 50 m. It is further proposed that useful test time can be maximised if an appropriately sized orifice plate is fitted to the tube exit, an arrangement which also offers practical advantages for testing. The paper demonstrates this operating capability with proof-of-concept experiments using The University of Queensland's X3 impulse facility.     

沉积物中六氯苯对摇蚊幼虫的慢性毒性效应

以淡水底栖动物花翅羽摇蚊(Chironomus kiiensis)幼虫为受试生物,研究了沉积物中六氯苯(HCB)对其28 d的慢性毒性效应,观察摇蚊幼虫的存活情况和活动行为,以死亡率、羽化率和羽化时间为受试终点,计算28 d试验后沉积物中HCB对摇蚊的半数致死浓度(lethal concentration 50,LC50)以及50%羽化时间(50%emergence time,EmT50)。结果表明,HCB对摇蚊28 d的LC50为59.8 mg·kg-1,对摇蚊羽化率的半数效应浓度(half maximal effective concentration,EC50)为59.8 mg·kg-1。与大多数污染物不同,HCB有促进摇蚊幼虫筑巢行为和羽化的作用,随着HCB染毒浓度升高,摇蚊幼虫筑巢行为加强,EmT50缩短。暴露于高浓度HCB(21.6 mg·kg-1)时,摇蚊的EmT50与对照相比明显缩短,尤其对雄性摇蚊影响更大。但与对照相比,HCB对羽化摇蚊的性别比没有很大影响。     

高炉喷吹煤评价及配比优化

为了提高某钢厂高炉喷吹煤粉的燃尽率,并实现混煤喷吹的配比最优化,采用热重分析和沉降炉试验研究方法,对单种煤的物化和燃烧性能进行了评价,在此基础上对不同配比的配合煤进行燃烧性能评价。研究结果表明,根据着火点最低和燃尽率最高的选取原则,配合煤的最佳优化配方为:52%混合无烟煤+40%烟煤+8%焦粉,燃烧效果良好。     

Simulation analysis on structure safety of coal mine mobile refuge chamber under explosion load

In order to check structural strength of coal mine mobiles refuge chamber, and do security evaluation of the mobile refuge chamber, a refuge chamber model was established, then a finite element method was instituted for it to ensure the refuge chamber would not be severely damaged when gas or coal dust explosion suddenly happened. A triangle shock wave with 1.2 MPa over-pressure, 300 ms lasting time was settled. Explicit nonlinear dynamic analysis program was used to simulate response of the refuge chamber. The maximum stress was 244 MPa, located in central part of sides and tail end of the last capsule. The maximum displacement was 29.32 mm, located in central part of sides and tail end of the last capsule. The calculation indicated that the refuge chamber was not obviously damaged. It could reliable work to meet safety requirements. Compared with the reported experimental results, the simulation method was verified. Based on analysis, suggestions were put forward for further improving.     

五管发酵测定粪大肠菌群的研究

通过实验摸索出粪大肠菌群的一种五管发酵法。该方法检测下限为9个/L,适用于地表水和废水中粪大肠菌群的测定。     

Prediction of dust cloud minimum ignition energy for organic dusts from modified hartmann tube data

The modified Hartmann tube apparatus is recognized to give realistic or safe indications of dust explosion violence. Evidence is presented that results from this apparatus can also be used to indicate minimum ignition energy. Published data show a correlation between minimum ignition energy and minimum explosible concentration, which is refined by also taking into account explosive violence. An empirical model has been derived, relating minimum ignition energy to minimum explosible concentration and explosive violence. The model allows estimation of probabilities of minimum ignition energy falling below specified values, such as those recognized as of practical importance by the relevant British Standard. A limited test of the model suggests that it can be applied to modified Hartmann tube data. It is anticipated that the model will be valuable as a screening tool, especially in the early stages of development of a project.     

旋转窑焊接筒体的失效分析与预防

从卧式旋转窑焊接筒体工作状态中的主要技术参数，分析和判断该系统内环缝接头产生疲劳失效的原因和部位。通过分析、计算、校核和建造失效树等方法，求出焊接筒体的失效模式，包括最小割集、失效概率和结构重要度等，从而提出预防失效的主要途径，为变厚度焊接筒体的设计为造、使用和维修提供了可借鉴的依据。     

Detonation characteristics of ammonium nitrate and activated carbon mixtures

To better understand the detonation characteristics of ammonium nitrate (AN) and activated carbon (AC) mixtures, steel tube tests were carried out for AN/AC mixtures of various compositions and different forms of AN (powdered, prilled, phase stabilized and granular), and the detonation velocity was measured. The powdered AN/AC mixtures gave higher detonation velocities than the other AN forms. For all the AN/AC mixtures, the experimentally observed detonation velocities at each loading density were far below the theoretically predicted values calculated by the CHEETAH code based on thermohydrodynamics, exhibiting so-called non-ideal detonation. The lowest detonation velocity of powdered AN/AC mixtures was obtained as D=1.25 km/s for an AC content of 0.1 wt%. This was considered to be close to the critical condition for stable detonation.