氘-氘聚变反应高能γ射线产额的实验研究

本文对低能D(d,γ)~4 He聚变反应进行了实验研究。由于D(d,γ)~4 He聚变反应γ射线的产额低、能量高、本底大,实验采用大NaI-塑料闪烁体反康谱仪,以提高探测效率并降低宇宙线的影响;采用脉冲束飞行时间方法区分中子和γ射线,以减小中子和宇宙线本底的影响。实验测量了300keV d束轰击厚D靶和薄D靶两种情况下的γ数据。在计算反应产生23.8 MeV的高能γ峰面积时,采用了拟合法扣除本底。实验测得,对厚靶,D(d,γ)4 He反应截面为2.47×10^(-37) m^2;对薄靶,D(d,γ)4 He反应截面为4.36×10^(-37) m^2。

UHMW-PE塑料板在电磁振动给料机上的应用

一、给料机工作简况 我公司焦炉备煤系统有150m3的配煤槽5个,下部为双曲线漏斗,并用鹤壁通用机械厂制造的5台电磁振动给料机与之配套。 电振机型号GZ5P,生产能力50t/h～70t/h,给料粒度【100mm,双振幅15mm,电压220V,工作电流12.7A,功率0.65kW,配套操作箱XKZ-20G2,振动频率50Hz,振动角20°,调谐指数0.9,功率因数cosφ=0.3。 给料机下料的稳定性及对湿煤的适应性,直接影响着电振机的生产率及配合煤的质量,也直接影响着焦炭的质量。

Co-pyrolysis characteristics of typical components of waste plastics in a falling film pyrolysis reactor

Waste plastics mainly come from MSW and usually exist in the form of mixed plastics. During the co-pyrolysis process of mixed plastics, various plastic components have different physicochemical properties and reaction mechanisms. Considering the high viscosity and low thermal conductivity of molten plastics, a falling film pyrolysis reactor was selected to explore the rapid co-pyrolysis process of typical plastic components(PP, PE and PS).The oil and gas yields and the compositions of pyrolysis products of the three components under different ratios at pyrolysis temperatures were analyzed to explore the co-pyrolysis characteristics of PP, PE, and PS. The study is of great significance to the recycling of waste plastics.

Conversion of Municipal Waste Plastic into Liquid Hydrocarbon Fuel Using a Stainless Steel Reactor

Plastic wastes from milk containers, soft drink bottles, plastic wraps, plastic flatware, etc. have been successfully converted into fuel. Two approaches for the conversion of waste post consumer plastic into fuel have been investigated： （1） muffle furnace to reactor liquefaction system; （2） direct liquefaction system. Majority of used plastics are derived from ethylene, propylene, butadiene and benzene. Waste plastics are plastics that are used by the people in their daily life. It is collected from outside and city municipalities. Some of them are coded and rests are non-coded. A developed process discussed in this paper works with most of the waste plastic, both coded and non-coded. The plastics are heated up at 120-380 ℃ temperature to melt. The gaseous vapor is then condensed into liquid fuel.

Molten waste plastic pyrolysis in a vertical falling film reactor and the influence of temperature on the pyrolysis products

Molten plastics are characterised with high viscosity and low thermal conductivity. Applying falling film pyrolysis reactor to deal with waste plastics can not only improve heat transfer efficiency, but also solve the flow problem. In this work, the pyrolysis process of molten polypropylene （PP） in a vertical falling film reactor is experimentally studied, and the influence of heating temperature on pyrolysis products is discussed. It has been found that with the temperature increases from 550 ℃ to 625 ℃, the yield of pyrolysis oil decreases from 74.4 wt% （ 4- 2.2 wt/%） to 53.5 wt% （± 1.3 wt%）. The major compositions of the pyrolysis oil are C9, C12 and C18, and β-scission reactions are predominant. The content of the light fraction C6-C12 of pyrolysis oil is 69.7 wt%. Compared with other pyrolysis reactors, the yield ofoil from vertical falling film pyrolysis reactor is slightly higher than that from tubular reactor, equal to that from rotary kiln reactor, and slightly lower than that in medium fluidised-bed reactor.

BAP Spray and Plastic Container Responses on Asparagus officmalis L. Crown Growth

The aims of this work were to study the effect of two different plastic containers on asparagus growth and the effect of early applied 6-benzilaminepurine （BAP） on crown growth during the first two years after seed germination. Although there was not found a root restriction effect with the use of plastic containers, there were significant differences between plants grown in plastic seedbed or single pots which suggesting an unusual and unexpected asparagus autotoxicity. The results showed that crown fresh weight, total dry weight, relative growth ratio （RGRroot）, root：shoot ratio and photosynthetic shoot number increased in BAP-sprayed plants over the controls without treatment as a result of a change in photosynthate partitioning towards the root system. The BAP snravs seem to be a ~reater effect under conditions with favor autotoxicitv such as the seedbed than in single pot crown-grown.

Catalytic Cracking of Polyolefins in the Molten Phase——Basic Study for the Process Development of Waste Plastics Liquefaction

The cracking of polyolefins, especially polyethylene in the molten state was effectively catalyzed by the powdery spent FCC （Fluid Catalytic Cracking） catalyst which was dispersed in it. The activation energy of the catalytic cracking of polyethylene was about 74 kJ/mol. The cracked product was naphtha and middle distillate as the major product and gaseous hydrocarbon （C1-C4） as the minor product while little heavy oil was produced. The chemical compositions of the product were： aromatic hydrocarbons, isoparaffins and branched olefins, whereas that of the non-catalyzed products were： n-olefins and n-paraffins with minor amount of dienes with increasing the process time. Additionally, the product pattern shifted from naphtha rich product to kerosene and gas-oil rich product. However, any catalytic product showed low fluid point （〈 -10 ℃）, while that of the non-catalyzed product was as high as 40 ℃. Catalyst could process, more than 100 times by weight of polyethylene with fairly small amount （- 30 wt%） of coke deposition. Spent catalyst gave higher hydrocarbons while fresh catalyst gave gaseous product as the major product. Other polyolefins such as polypropylene and polystyrene were tested on same catalyst to show that their reactivity is higher than that of polyethylene and gave the aliphatic products, alkyl benzenes and C6-C9 iso-paraffins as the major product. Product pattern of the cracked product suggested that the reaction proceeded via the primary reactions making paraffins and olefins which were followed by the isomerization, secondary cracking, aromatization and hydrogen transfer which based on the carbenium ion mechanism.

Line field analysis and complex variable method for solving elastic-plastic fields around an anti-plane elliptic hole

A new approach is proposed to solve the elastic-plastic fields near the major-axis line of an elliptical hole. The complex variable method is used to determine the elastic fields near the major-axis line of the elliptical hole. Then, by using the line field analysis method, the exact and new solutions of the stresses, strains in the plastic zone, the size of the plastic region and the unit normal vector of the elastic-plastic boundary near the major-axis line of the elliptical hole are obtained for an anti-plane elliptical hole in a perfectly elastic-plastic solid. The usual small scale yielding assumptions are not adopted in the analysis. The present method is simple, easy and efficient. The influences of applied mechanical loading on the size of plastic zone are discussed.