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61.
62.
对少烟HTPB/AP/RDX/A1推进剂能量性能进行了理论计算,通过BSFφ165和φ315试验发动机试验,考察了试验发动机类型,工作压力对经冲效率的影响,而且与高铅含量HTPB/AP/RDX/A1推进剂的比冲效率进行了比较,结果表明,铅含量对推进剂的比冲效率有显著的影响,低铝配方的比冲效率比高铝配方的比冲效率相对要高些;对于推进剂组分确定的配方,合适选择发动机的工作压力,可以不同程度地提高比冲效率,对于同一类型推进剂配方,通过计算理论比冲,结合比冲效率水平,可以对实际比冲进行有效的预估。 相似文献
63.
间歇窑窑墙温度场图形仿真研究 总被引:2,自引:0,他引:2
本文利用有限差分法求解间歇窑窑墙中的温度分布,并用C语言设计了窑墙温度场图形仿真软件。输入窑墙厚度和材料的物性参数等,系统可进行窑墙温度场分布的实时仿真及窑炉结构与操作的优化 相似文献
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This work investigates the performance of a spray dryer for tomato powder preparation by spray drying of tomato pulp. Samples of tomato pulp with a 14% constant total solids concentration were used, and a pilot scale spray dryer (Buchi, B-191) with cocurrent operation and a two-fluid nozzle atomizer was employed for the spray drying process. Twenty-four different experiments were conducted keeping constant the feed rate, the feed temperature, and the atomizer pressure, and varying the compressed air flow rate, the flow rate of drying rate, and the air inlet temperature. In each experiment the air outlet temperature was recorded. Data for the residue remaining in the chamber and cyclone walls was gathered and two types of efficiencies were calculated as an indication of the spray dryer performance. Analysis of experimental data yielded correlations between residue accumulation and the variable operating conditions. The same operating parameters had a great influence on the air outlet temperature whereas temperature deviations were observed comparing measured air outlet temperatures with corresponding outlet adiabatic saturation temperatures. 相似文献
67.
电脉冲清洗机就是基于"液电效应"设计的新型清洗机,是众多清洗方式中的一种,它采用"液电效应"机理,把电能转化为液动力作用于管道内的垢体,使垢体在冲击波的作用下,与管道脱离,达到清垢目的.在垢比较密实,管道较长或弯曲的情况下,采用电脉冲清洗机除垢效果较好. 相似文献
68.
This study is an experimental investigation of heat and moisture transfer within a packed bed of polycrystalline, porous potash pellets. Experiments were first performed to determine the moisture uptake characteristics on individual pellets subject to a step-change in relative humidity. Then a bed of pellets was subjected to flows of humid air on the upper boundary and a cold impermeable surface on the lower boundary resulting in a temperature gradient across the bed. Temperature and moisture content were measured within the bed. It was found that moisture uptake is less for potash pellets and they are less likely to cake than granular and standard potash when subjected to the same ambient air conditions. This is due to the porous nature of the pellet and its nearly uniform size and spherical shape. 相似文献
69.
Sheng-Mao Yang S. S. Malhi Jian-Rong Song You-Cai Xiong Wei-Yun Yue Li Li Lu Jian-Guo Wang Tian-Wen Guo 《Nutrient Cycling in Agroecosystems》2006,76(1):81-94
Application of chemical fertilizers and farmyard manure affects crop productivity and improves nutrient cycling within soil–plant systems, but the magnitude varies with soil-climatic conditions. A long-term (1982–2004) field experiment was conducted to investigate the effects of nitrogen (N), phosphorus (P), and potassium (K) fertilizers and farmyard swine manure (M) on seed and straw yield, protein concentration, and N uptake in the seed and straw of 19-year winter wheat (Triticum aestivum L.) and four-year oilseed (three-year canola, Brassica napus L. in 1987, 2000 and 2003; one-year flax, Linum usitatisimum L. in 1991), accumulation of nitrate-N (NO3-N) in the soil profile (0–210 cm), and N balance sheet on a Huangmian soil (calcaric cambisols, FAO) near Tianshui, Gansu, China. The two main plot treatments were without and with farmyard swine manure (M); sub-plot treatments were control (Ck), N, NP, and NPK.␣The average seed yield decreased in the order MNPK ≥ MNP > MN ≥ NPK ≥ NP > M > N > Ck. The average effect of manure and fertilizers on seed yield was in the order M > N > P > K. The seed yield increase was 20.5% for M, 17.8% for N, 14.2% for P, and 2.9 % for K treatment. Seed yield response to fertilizers was much greater for N and P than for K, and it was much greater for no manure than for manure treatment. The response of straw yield to fertilization treatments was usually similar to that of seed yield. The N fertilizer and manure significantly increased protein concentration and N uptake plant. From the standpoint of increasing crop yield and seed quality, MNPK was the best fertilization strategy. Annual applications of N fertilizer and manure for 23 successive years had a marked effect on NO3-N accumulation in the 0–210 cm soil profile. Accumulation of NO3-N in the deeper soil layers with application of N fertilizer and manure is regarded as a potential danger, because of pollution of the soil environment and of groundwater. Application of N fertilizer in combination with P and/or K fertilizers reduced residual soil NO3-N significantly compared with N fertilizer alone in both no manure and manure plots. The findings suggest that integrated and balanced application of N, P, and K fertilizers and␣manure at proper rates is important for protecting soil and groundwater from potential NO3-N pollution and for maintaining high crop productivity in the rainfed region of Northwestern China. 相似文献
70.
应用三维模拟技术,强化油气成藏体系动态演化过程,采用正反演结合的思路,探讨叠合盆地油气成藏体系的研究思路和方法。研究过程分五步:通过成藏要素研究构建地质模型;通过正演烃源岩生烃过程与时空演化,分阶段计算生烃量;通过输导体系研究来调整油气最终的分布;应用油气组分追踪技术分析不同烃源岩层贡献比例;根据三维模拟结果动态分析资源空间分布及变化过程。 相似文献