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121.
The transverse momentum spectra of different types of particles, , , p and , produced at mid-(pseudo)rapidity in different centrality lead–lead (Pb–Pb) collisions at 2.76 TeV; proton–lead (p–Pb) collisions at 5.02 TeV; xenon–xenon (Xe–Xe) collisions at 5.44 TeV; and proton–proton (p–p) collisions at 0.9, 2.76, 5.02, 7 and 13 TeV, were analyzed by the blast-wave model with fluctuations. With the experimental data measured by the ALICE and CMS Collaborations at the Large Hadron Collider (LHC), the kinetic freeze-out temperature, transverse flow velocity and proper time were extracted from fitting the transverse momentum spectra. In nucleus–nucleus (A–A) and proton–nucleus (p–A) collisions, the three parameters decrease with the decrease of event centrality from central to peripheral, indicating higher degrees of excitation, quicker expansion velocities and longer evolution times for central collisions. In p–p collisions, the kinetic freeze-out temperature is nearly invariant with the increase of energy, though the transverse flow velocity and proper time increase slightly, in the considered energy range. 相似文献
122.
《印度化学会志》2021,98(12):100235
India has abundance of biomass such as rice husk, bagasse, wheat straw, sawdust etc. which is used as a main or auxiliary fuel in the fluidized bed combustor, gasifier and pyrolizer. Design of such fluidized bed equipments require the knowledge of minimum fluidization velocity (Umf), complete fluidization velocity (Ucf) and transport disengagement height (TDH). The present work reports the fluidization characteristic, Umf, Ucf and TDH of the individual size groups of sawdust and mixture thereof. The results indicate that the Umf and Ucf have a tendency to increase with increase in particle diameter, however the TDH shows the reverse trend. The sawdust particle size of 925 and 1200 μm showed significant difference between their Umf and Ucf, an essential parameter for controlled fluidization. Based on the experimental work new correlations for the prediction of Umf, Ucf and TDH for sawdust sample are proposed. The proposed correlations of Umf, Ucf and TDH are in good agreement with experimental values and the deviations found within the range of nearly ±10% for all the samples. 相似文献
123.
The adhesive joints are suddenly disturbed by the impact loadings in industrial applications. The stress wave propagation and stress distribution in the single lap joint (SLJ) with aluminum alloy adherends and two types of epoxy adhesives under impact tensile loadings are analyzed with the finite element method (FEM) to simulate the drop weight test. The impact velocity is assumed below 2000 mm s−1 and the total impact history is 0.2 ms. The stress is observed throughout the middle plane in the overlap area. The stress wave propagation in the adhesive layer reveal obvious directivity and show the transformation from the elastic wave to the plastic wave. The equivalent Von‐Mises stress increases approximately linearly with the increase of impact energy. At different times, the equivalent Von‐Mises stress along the adhesive longitude present bimodal distribution, while the stress wave propagation characterizes the rising‐falling‐rising trend. The stress singularity area is around 3–5 mm from edges. The equivalent Von‐Mises stress of the transversal middle plane in the adhesive layer is sensitive to rupture with the symmetrical distribution. A damage sensitive area located 2.6 mm away from both edges. The upper interface of the adhesive layer may initiate failure under the low‐velocity impact. 相似文献
124.
Shivanand Chaurasia Usha Rao Ashutosh Mohan 《Journal of Raman spectroscopy : JRS》2021,52(6):1212-1221
Para-xylene is one of the highly used aromatic compounds in petroleum, chemical, agriculture, aviation, and polymer industries, and hence, it is necessary to study p-Xylene behavior under extreme conditions (high pressure and high temperature). Here, we report a detailed study on p-Xylene under nanosecond laser-driven dynamic compression (up to 4.5 GPa) and shock temperatures (up to 1,300 K). The experimental observations are compared with previous reported study using hydrostatic compression. A time-resolved Raman spectroscopy is also done for the estimation of shock velocity in the p-Xylene sample using the intensity ratio of the Raman modes from the shocked region to that of the whole sample region. The shock velocities for the laser energy on sample at 700 mJ (corresponding pressure 2.5 GPa) deduced by the Raman active modes at 810, 827, and 1204 cm−1 are 3.60 ± 0.46, 3.67 ± 0.17, and 3.78 ±0.09 km/s, respectively. One-dimensional (1-D) radiation hydrodynamic simulation is also performed for the validation of experimental results. The shock velocity from the simulation at the same laser energy is 3.51 km/s and is in good agreement with the experimental data. The Gruneisen parameters calculated for various Raman modes such as ν10 (644 cm−1), ν13 (810 cm−1), ν14 (827 cm−1), ν18 (1,204 cm−1), ν27 (2,863 cm−1), ν30 (3,011 cm−1), and ν31 (3,053 cm−1) are γi = 0.08959 ± 0.00687,0.1956 ± 0.03851,0.19888 ± 0.01417,0.05477 ± 0.02143,0.09342 ± 0.0335,0.00551 ± 0.02472,0.01942 ± 0.02244, respectively, and are volume independent. 相似文献
125.
研究了聚合物熔体在衣架型模头中的等温流动。采用幂律模型描述该熔体的流变行为,通过三维有限元方法对此流动进行模拟,从而得到其速度场的分布情况,并且着重讨论了衣架型模头的几何形状对速度场分布的影响,特别是对出口宽度方向速度均匀性的影响。 相似文献
126.
杨久志 《江苏大学学报(自然科学版)》1997,(1)
论述了用对偶矢量计算开环机构末杆自由度在机构自由度计算中的应用，并给出以这种方法计算各种不同类型闭环机构自由度的算例． 相似文献
127.
文章对西昆仑造山带早华力西变形期的古应力差值、应变速率进行了估算，并对估算的结果进行了分析。对透射电镜所拍摄的变形颗粒位错形态照片，采用位错密度、动态重结晶和亚晶粒粒径等方法进行古应力差值的估算，并估算了该期变形的应变速率。古应力差值σ１－σ３＝８０～１５０ＭＰａ，应变速率６×１０－１４～２×１０－１３ｓ－１，为中速应变。初步推算，该期变形作用大约持续了２．１６Ｍａ。 相似文献
128.
本文研究分析了煤岩层的物性参数分布规律和组合特征，阐述了井下物探多参数综合应用的方法原理。通过探测实例论述了井下物探采用多参数综合物探的必要性。指出多参数井下物探可以消除资料的多解性，提高资料解释的准确性。对井下物探工作具有一定的指导意义。 相似文献
129.
袁德荣 《湖北大学学报(自然科学版)》1997,19(1):48-52
研究了带有对称双阱势的氢键链中孤子与杂质的相互作用，排斥型杂质对孤子提供一个势垒，吸引型杂质对孤子提供一个势阱，并且吸引型杂质获取孤子的能量形成局域振荡模，被杂质散射的孤子存在一个临界速度，只有入射速度大于临界速度的孤子才能穿越排斥型杂质，或者不被吸收型杂质捕获。 相似文献
130.
徐宗起 《烟台大学学报(自然科学与工程版)》1997,10(1):70-75
在圆形断面的排水管道设计中，有时需要计算不满流条件下一定充满度时的流量及流速，针对有不同满注的流量，流速与对应的满流的流量，流速的比值，现推荐的解析表达式，便于从充满度直接计算流量比，流速比。 相似文献