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991.
Steady-state nonlinear differential equations govering the stem curve of a wind-loaded pine are derived and solved numerically. Comparison is made between the results computed and the data from photographs of a pine stem during strong wind. The pine breaking is solved at the end. 相似文献
992.
993.
Thermal characteristics and rheological behaviour of eight crude oils covered a wide range of fluid composition and properties
were studied by differential scanning calorimeter (DSC) and viscometry. Wax appearance temperatures (WAT) of crude oils were
determined by DSC and viscometry. Good agreement is obtained between the results. The dynamic viscosity in the Newtonian temperature
range of the crude oils (above 30°C) generally obeyed a simple first-order Arrhenius type of temperature dependence. Activation
energies of flow in the non-Newtonian range are not uniquely defined.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
994.
995.
五像限法太阳自动跟踪仪 总被引:2,自引:0,他引:2
介绍由两心圆组成的等面积五像限光测量装置工作原理,即当光线与光电池垂直时其投影光斑经过一透镜后正好安全覆盖五片光电池,当光线与光电池成一夹角时,其投影光斑必然发生偏移,将光主在光电池上的偏移转移成光电流差值的变化,实现装置自动跟踪太阳。 相似文献
996.
We present a new method for estimating the frontier of a sample. The estimator is based on a local polynomial regression on the power-transformed data. We assume that the exponent of the transformation goes to infinity while the bandwidth goes to zero. We give conditions on these two parameters for obtaining almost complete convergence. The asymptotic conditional bias and variance of the estimator are provided and its good performance is illustrated for some finite sample situations. 相似文献
997.
We report the inverse Meyer–Neldel (MN) rule in the thermally activated crystallization of a hybrid composite of phenol formaldehyde using two experimental approaches. In the first experiment, the annealing time dependence of the pre-exponential factor K 0 and the activation energy of crystallization E c were studied. In the second experiment, the annealing temperature dependence of the same parameters was investigated. We observed the inverse Meyer–Neldel rule between the pre-exponential factor K 0 and the activation energy of crystallization E c in both cases. 相似文献
998.
Oscillation theorems for a second-order impulsive neutral differential equation are established, which extend the main results developed by Li et alLi et al, Oscillation of second order self-coajugate differential equation with impuls[es. J Comput Appl Math 197(2006): 78-88] to the considered equation. Two examples are also inserted to illustrate our main results. 相似文献
999.
1000.
Doria Affane 《Applicable analysis》2013,92(12):1677-1690
This article studies some Bolza-type problems governed by second-order differential inclusions with two boundary conditions, where the controls are Young measures. 相似文献