Flame radiant image numeralization for pulverized coal combustion in BF raceway

1 Introduction 1 For pulverized coal injected into a blast furnace, the space from the outlet of the coal gun to the center of the raceway is the key district for the coal’s burning and also for works to probe hearth state. Remarkable achievements have been made in research on numerical simulation of combustion processes [1], but further advances are hindered owing to the limits of the means to examine three-dimension parameter distribution in the furnace. Temperature is the most basic parame…     

温度胁迫对蜡梅种子萌发的影响

在室内条件下,初步探究了温度对蜡梅种子萌发的影响.结果表明:(1)蜡梅种子千粒重为212.094±4.168 g.种壳限制蜡梅种子吸水进程,有种壳,浸种96 h,吸水率不足8%,去除种壳,10 h内,吸水率达80.2%.(2)四个温度处理下,萌发率(%)大小为:25℃(78.33)>15℃(77.5)>30℃(55)>4℃(0),4℃下,萌发率为0,15℃种子基本能正常萌发,但萌发活力指数下降,25℃下,种子萌发率,发芽势,活力指数最高,萌发速率最快,30℃下,萌发率显著下降.(3)根TTC还原活力(mg/g/h)比较:25℃(0.5348)>15℃(0.4361)>30℃(0.3318),温度对幼苗鲜、干重、含水量无显著影响,对胚根长度影响显著.可见,种壳限制蜡梅种子吸水,进而影响其萌发.低温限制蜡梅种子萌发,在一定范围内,降温对蜡梅萌发影响不大,高温则延迟萌发,且降低蜡梅种子萌发速度和质量,蜡梅萌发适合的温度在25℃左右.     

Studying creation of bulk elementary excitation by heaters in superfluid helium-II at low temperatures

In this paper, the obtained experimental results concerning creation of bulk elementary excitations (BEEs) in iso-topically pure liquid 4He at low temperatures ~60 mK are discussed. Positive rotons’ (R -rotons) creation by a pulsed heater was studied. Signals were recorded for the following quantum processes: quantum evaporation of 4He-atoms from the free liq- uid-helium surface by the BEEs of the liquid helium-II, and BEEs reflection from the free surface back into the bulk liquid. Typical signals are shown, and ratios of signal amplitudes are evaluated. For long heater pulses from 5 to 10 μs, appearance of the second atomic cloud consisting of evaporated 4He-atoms was observed in addition to the first atomic cloud. It is thought that the first atomic cloud of the evaporated helium atoms consists of very fast 4He-atoms with energies ~35 K evaporated by positive rotons with the special energies ~17 K (~2ER~2×8.6 K with ER representing the roton minimum energy) corresponding to the third non-dispersive Zakharenko wave. The second cloud of slower 4He-atoms was created by surface elementary excitations (SEEs or ripplons) possessing the special energies ~7.15 K representing the binding energy. It was assumed that such SEEs can be created by phonons incoming to the liquid surface with special energies ~6.2 K corresponding to the first non-dispersive Zakharenko wave, which can interact at the liquid surface with the same phonons already reflected from the surface for long heater pulses. Also, some pulsed-heater characteristics were studied in order to better understand the features of such heaters in low temperature experi- ments.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

直流电位法自动检测高温疲劳裂纹长度的研究及应用

利用Johnson的分析型关系式,研究了一种适用于自动检测高温疲劳裂纹长度的直流电位法,成功地应用于三种铝合金和两种钛合金的高温疲劳裂纹扩展试验。用直流电位法和光学视频法所检测的裂纹长度相当吻合,其检测精度在±3%之内。对研究材料的疲劳门槛值、宽板的裂纹扩展速率和小裂纹试验有其推广应用价值。     

JTFB—93防爆型可燃气体泄漏报警器

本文对金属氧化物半导体气敏传感器和CD212气敏传感器的性能作了分析和比较,并介绍了适用于瓦斯气、液化石油气等可燃气体的贮气仓库使用的JTFB—93防爆型可燃气体泄漏报警器的设计思想、电路结构、工作原理、主要技术指标、调试和使用方法。     

Corner strength enhancement of high strength cold-formed steel at normal room and elevated temperatures

In this study, the suitability of current design methods for the 0.2% proof yield strength of the comer regions for high strength cold-formed steel at normal room temperature was investigated. The current standard predictions are generally accurate for outer comer specimen but conservative for inner comer specimen. Based on the experimental results, an analytical model to predict the comer strength of high strength cold-formed steel at normal room temperature was also proposed. The comparison indicated that the proposed model predicted well the comer strength of high strength cold-formed steel not only at normal room temperature but also at elevated temperatures. It is shown that the predictions obtained from the proposed model agree well with the test results. Generally the comer strength enhancement of high strength cold-formed steel decreases when the temperature increases.     

Behaviour of cold-formed stainless steel beams at elevated temperatures

A study of the behaviour of constructional cold-formed stainless steel beams at elevated temperatures was conducted in this paper. An accurate finite element model （FEM） for stainless steel beams was developed using the finite element program ABAQUS. Stainless steel beams having different cross-sections were simulated in this study. The nonlinear FEM was verified against the experimental results. Generally, the developed FEM could accurately simulate the stainless steel beams. Based on the high temperature stainless steel material test results, a parametric study was carried out on stainless steel beams at elevated temperatures using the verified FEM. Both high strength stainless steel EN 1.4462 and normal strength stainless steel EN 1.4301 were considered. A total of 42 stainless steel beams were simulated in the parametric study. The effect of temperatures on the behaviour of stainless steel beams was investigated. In addition, a limiting temperature for stainless steel beams was also proposed.     

浙江省极端温度事件及其对区域气候增暖响应的分析

利用浙江省24个气象站1960至2008年逐日温度资料,建立能较好反映极端温度事件的四类指数序列,分析浙江省极端温度事件变化特征及其对区域气候增暖的响应。结果表明,浙江省极端温度事件有明显的区域性特征,近几十年来,各区域极端暖日和极端暖夜指数表现出一致的增长趋势,而极端冷日和极端冷夜指数则呈现减少趋势,相对而言极端暖日和极端冷夜指数变化趋势更为明显,且在90年代初为极端温度指数变化的一突变期。在考虑未来气候变暖的背景下,极端温度指数均有不同程度的响应。     

高温后高强高性能混凝土双轴压强度规律与破坏准则

利用大型静动真三轴试验机,进行了常温20℃以及200,300,400,500和600℃高温后高强高性能混凝土在7种应力σ2∶σ3=0∶-1,-0.20∶-1,-0.30∶-1,-0.40∶-1,-0.50∶-1,-0.75∶-1,-1.00∶-1双轴压试验.单双轴压试块尺寸为100 mm×100 mm×100 mm立方体.受压面的减摩垫层为3层塑料薄膜中间夹3层黄油.测得了双轴主压方向的静态强度,剖析了温度和应力比对单、双轴压强度发展趋势的影响规律以及试件破坏形态.试验结果表明:随温度的升高,高温后高强高性能混凝土的单轴压强度并不一定降低;双轴压强度相对于其单轴的提高倍数取决于应力比、不同温度等级后的高强高性能混凝土"脆硬性".提出了修正的带有温度和应力比参数高强高性能混凝土Kupfer-Gerstle破坏准则公式.