This paper presents a study on ＇hard＇ and ＇soft＇ interactions in ^-pp （pp） collisions using a phenomenological model of HIJING, the jet-cone reconstruction method is employed to select the ＇hard＇ and ＇soft＇ ...This paper presents a study on ＇hard＇ and ＇soft＇ interactions in ^-pp （pp） collisions using a phenomenological model of HIJING, the jet-cone reconstruction method is employed to select the ＇hard＇ and ＇soft＇ event sub-samples from minimum bias events. It is found that the HIJING model can reproduce the energy scaling behaviour of mean transverse momentum （〈PT〉） distributions of charged hadrons versus multiplicity （Nch） in ＇soft＇ events. From the PYTHIA simulation comparing with the HIJING model, the enhancement of the kaon and proton yields from ＇hard＇ interactions comparing with ＇soft＇ interactions is observed to be due to the mini-jets effect. These mechanisms responsible for the increase of charged hadron＇s （PT） are different in ＇soft＇ and ＇hard＇ interactions.展开更多
The characteristics of the mass transfer between powder particles and liquid steel in the Ruhrstahl Heraeus process injection （RH-IJ） refining were simulatively investigated by the use of a 1/4 scale water model of ...The characteristics of the mass transfer between powder particles and liquid steel in the Ruhrstahl Heraeus process injection （RH-IJ） refining were simulatively investigated by the use of a 1/4 scale water model of a 150 t Ruhrstahl Heraeus（RH） degasser. The influences of the lifting gas flow rate, the up-snorkel and down-snorkel inner diameters and the size of powder particles on the characteristics of the mass transfer were examined. The results show that under the condition that the inner diameters of both the up-snorkel and the down-snorkel are the same, the mass transfer coefficient in the liquid,k increases with the increase of the inner diameter of the up-snorkel,the particle size and the lifting gas flow rate （Q1）. However, the increase of Q~ should not result in a saturated circulation rate. Under the current working condition,k ranges from 3. 392 × 10 -5 m/s to 2. 661 × 10-4 m/s. On the other hand,with a given lifting gas flow rate and up-snorkel inner diameters ,the mass transfer weakens with the increase of the down-snorkel inner diameter. An inherently nonlinear relationship between the circulation rate （Q~） of molten steel in the RH degasser and k,which increases with the increase of Q1,was found. Under the condition of other parameters being the same,k increases with the increase of the powder particle size. In order to enhance the mass transfer,it is better not to use extremely fine powder.展开更多
Ⅰ. INTRODUCTION In the theory of stability for difference differential equation and functional differential equation, the null points distribution of the transcendental function det (aij+bije-λτ—δijλ)n×n is...Ⅰ. INTRODUCTION In the theory of stability for difference differential equation and functional differential equation, the null points distribution of the transcendental function det (aij+bije-λτ—δijλ)n×n is a basic problem to be studied so far as we know the transcendental criteria for null points distribution of the polynomial H(λ, e-λ) were given by L. S. Pontriagin. Qin Yuanxun et al. offered the equivalent algebraic criteria. All these are sufficient and necessary conditions. But when n≥2, it is rather difficult to check the conditions of these criteria.展开更多
采用CSR(Center for Space Research)公布的RL05版本的2002-07-2015-04近13年的GRACE卫星月重力数据,计算分析了南极冰盖质量变化趋势。通过比较300km的高斯平滑滤波、扇形滤波以及去条带扇形滤波算法对于去条带噪声的效果,确定去条带...采用CSR(Center for Space Research)公布的RL05版本的2002-07-2015-04近13年的GRACE卫星月重力数据,计算分析了南极冰盖质量变化趋势。通过比较300km的高斯平滑滤波、扇形滤波以及去条带扇形滤波算法对于去条带噪声的效果,确定去条带扇形滤波算法效果更好。分析对比了Geruo13、IJ05_R2、W12a这3种GIA模型对南极冰盖质量变化的影响,发现不同GIA模型计算的南极冰盖质量变化差异明显,尤其在坎普冰流、龙尼冰架和东南极等区域差别较大。本文分3个时间段反演计算了南极冰盖质量变化,结果显示,不同时间段质量变化存在很大差异,且南极冰盖质量变化呈现非常明显的地区不平衡性,主要体现在西南极、南极半岛、恩德比地、龙尼冰架和毛德皇后地等区域。展开更多
基金Project supported by National Natural Science Foundation of China （Grant Nos 10275060 and 10475071）.
文摘This paper presents a study on ＇hard＇ and ＇soft＇ interactions in ^-pp （pp） collisions using a phenomenological model of HIJING, the jet-cone reconstruction method is employed to select the ＇hard＇ and ＇soft＇ event sub-samples from minimum bias events. It is found that the HIJING model can reproduce the energy scaling behaviour of mean transverse momentum （〈PT〉） distributions of charged hadrons versus multiplicity （Nch） in ＇soft＇ events. From the PYTHIA simulation comparing with the HIJING model, the enhancement of the kaon and proton yields from ＇hard＇ interactions comparing with ＇soft＇ interactions is observed to be due to the mini-jets effect. These mechanisms responsible for the increase of charged hadron＇s （PT） are different in ＇soft＇ and ＇hard＇ interactions.
文摘The characteristics of the mass transfer between powder particles and liquid steel in the Ruhrstahl Heraeus process injection （RH-IJ） refining were simulatively investigated by the use of a 1/4 scale water model of a 150 t Ruhrstahl Heraeus（RH） degasser. The influences of the lifting gas flow rate, the up-snorkel and down-snorkel inner diameters and the size of powder particles on the characteristics of the mass transfer were examined. The results show that under the condition that the inner diameters of both the up-snorkel and the down-snorkel are the same, the mass transfer coefficient in the liquid,k increases with the increase of the inner diameter of the up-snorkel,the particle size and the lifting gas flow rate （Q1）. However, the increase of Q~ should not result in a saturated circulation rate. Under the current working condition,k ranges from 3. 392 × 10 -5 m/s to 2. 661 × 10-4 m/s. On the other hand,with a given lifting gas flow rate and up-snorkel inner diameters ,the mass transfer weakens with the increase of the down-snorkel inner diameter. An inherently nonlinear relationship between the circulation rate （Q~） of molten steel in the RH degasser and k,which increases with the increase of Q1,was found. Under the condition of other parameters being the same,k increases with the increase of the powder particle size. In order to enhance the mass transfer,it is better not to use extremely fine powder.
文摘Ⅰ. INTRODUCTION In the theory of stability for difference differential equation and functional differential equation, the null points distribution of the transcendental function det (aij+bije-λτ—δijλ)n×n is a basic problem to be studied so far as we know the transcendental criteria for null points distribution of the polynomial H(λ, e-λ) were given by L. S. Pontriagin. Qin Yuanxun et al. offered the equivalent algebraic criteria. All these are sufficient and necessary conditions. But when n≥2, it is rather difficult to check the conditions of these criteria.
文摘采用CSR(Center for Space Research)公布的RL05版本的2002-07-2015-04近13年的GRACE卫星月重力数据,计算分析了南极冰盖质量变化趋势。通过比较300km的高斯平滑滤波、扇形滤波以及去条带扇形滤波算法对于去条带噪声的效果,确定去条带扇形滤波算法效果更好。分析对比了Geruo13、IJ05_R2、W12a这3种GIA模型对南极冰盖质量变化的影响,发现不同GIA模型计算的南极冰盖质量变化差异明显,尤其在坎普冰流、龙尼冰架和东南极等区域差别较大。本文分3个时间段反演计算了南极冰盖质量变化,结果显示,不同时间段质量变化存在很大差异,且南极冰盖质量变化呈现非常明显的地区不平衡性,主要体现在西南极、南极半岛、恩德比地、龙尼冰架和毛德皇后地等区域。
