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41.
热等离子体裂解天然气制备C2烃 总被引:1,自引:0,他引:1
采用氮气热等离子体来裂解天然气制备乙炔乙烯,着重研究了天然气转化率和乙炔、乙烯收率随氮气流量和天然气流量的变化.结果表明,天然气流量与氮气流量之比为11时,可得到较好的结果.当等离子体功率为15kW、天然气流量为3Nm3*h-1、氮气流量为3Nm3*h-1时得到最好的结果.这时天然气转化率为57%,乙炔、乙烯的收率分别为34%和9%;乙炔在反应气中的体积浓度为7.5%,与部分氧化法相似;扣除不参加反应的氮气,乙炔在气相产品中的体积浓度为13.2%,与热力学平衡计算结果基本符合. 相似文献
42.
The following results are proved in this paper. Let G be a 2k-edge-connected eulerian graph. (i) For every set {e1, e2, ?, e2k+1} ? E(G) there is an eulerian trail T of the form e1, e2, ?, e2k+1, ?. (ii) For every set E* = {e1, e2, ?, ek} ? E(G) there is an eulerian trail T = e1, ?, e2, ?, ek, ? in which the elements of E* are traversed in accordance with a prescribed orientation. © 1995 John Wiley & Sons, Inc. 相似文献
43.
Zhengqian Luo Guoyong Sun Zhiping Cai Miaoling Si Qibo Li 《Optics Communications》2007,277(1):118-124
In this paper, continuous wave Yb3+-doped double-clad fiber lasers (DCFLs) with linear-cavity are investigated theoretically and numerically using the rate equations. Under the steady state conditions, the simplified analytic solutions of Yb3+-doped DCFLs under considering the scattering loss are deduced in the strongly pump condition. Compared with the known analytic solutions in published literatures, our analytic solutions are more accurate, especially, at higher reflectivity of output mirror. In addition, a fast and stable algorithm based on the Newton-Raphson method is proposed to simulate numerically Yb3+-doped DCFLs. The results by simplified analytic solutions are in good agreement with those by the numerical simulation. Moreover, we have performed the optimization of an Yb3+-doped DCFL using the simplified analytic solutions and the numerical simulations, respectively. 相似文献
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Ping-xing Chen Jian-ming Cai Zheng-wei Zhou Guang-can Guo 《量子光学学报》2006,12(B08):72-73
The second law of thermodynamics is one of the most fundamental and for-reaching laws of physics. It teaches us that when a closed system undergoes a thermodynamic process the entropy of the system never decreases; it increases, or at least remains constant. If the entropy increases the thermodynamic process is irreversible, otherwise it is reversible. Only ideal thermal process is reversible. In classical world a great number of facts have proved the second law is true. But in quantum world since the quantum coherence and correlations exist we are not sure the second law is still true, at least in principle. This is because that: 1. on the microscopic level the irreversibility is conflict with the reversibility of all fundamental physical laws ; 2. there are not enough evidences to show it is true in quantum world. 相似文献
46.
The melting curve of MgSiO分子动力学 MgSiO3钙钛矿 熔化温度 高压 melting temperature, molecular dynamics, high pressure Project supported by the National Natural Science Foundation of China (Grant Nos 10274055 and 10376021),the Natural Science Foundation of Gansu Province, China (Grant No 3ZS051-A25-027) and the Scientific Research Foundation of Education Bureau of Gansu Province, China (Grant No 0410-01). 2005-01-12 5/8/2005 12:00:00 AM The melting curve of MgSiO3 perovskite is simulated using molecular dynamics simulations method at high pressure. It is shown that the simulated equation of state of MgSiO3 perovskite is very successful in reproducing accurately the experimental data. The pressure dependence of the simulated melting temperature of MgSiO3 perovskite reproduces the stability of the orthorhombic perovskite phase up to high pressure of 130GPa at ambient temperature, consistent with the theoretical data of the other calculations. It is shown that its transformation to the cubic phase and melting at high pressure and high temperature are in agreement with recent experiments. 相似文献
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The contrast of interference pattern formed by two circularly polarized waves and by a linearly polarized wave and a circularly polarized one is discussed. The results are compared with that by two linear beams. It shows that the use of circular light in holographic fabrication of three-dimensional periodic microstructures may remove the necessity of beam ratio and polarization optimization needed in the interference of three linear noncoplanar beams and improve the uniform contrast of resultant pattern simultaneously. 相似文献
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50.
采用一种新的种子层材料:(Ni081Fe019)1-xCrx,通过改变种子层中Cr原子的含量,使得在其上生长的NiFeFeMn双层膜的织构和晶粒尺寸产生极大的差异,系统研究了NiFeFeMn双层膜中FeMn晶粒尺寸和织构对交换偏置的影响.实验结果表明,在FeMn的γ相(111)织构较好的前提下,交换偏置场的大小与织构的差异没有关系;FeMn的晶粒尺寸对交换偏置场有很大影响,较小的反铁磁层晶粒对交换偏置场有利,过大的反铁磁层晶粒不利于交换偏置场.将(Ni081Fe019)05Cr05与传统的种子层材料Ta进
关键词:
交换偏置
晶粒尺寸
织构
种子层 相似文献