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51.
52.
Leila Hojabri Xiaohua Kong Suresh S. Narine 《Journal of polymer science. Part A, Polymer chemistry》2010,48(15):3302-3310
A novel long chain linear unsaturated terminal diisocyanate, 1,16‐diisocyanatohexadec‐8‐ene (HDEDI) was synthesized from oleic acid via Curtius rearrangement. Its chemical structure was identified by FTIR, 1H NMR, 13C NMR, and HRMS. This diisocyanate was used as a starting material for the preparation of entirely bio‐based polyurethanes (PUs) by reacting it with canola diol and canola polyol, respectively. The physical properties and crystalline structure of the PUs prepared from this diisocyanate were compared to their counterparts prepared from similar fatty acid‐derived diisocyanate, 1,7‐heptamethylene diisocyanate (HPMDI). The HDEDI based PUs demonstrated various different properties compared to those of HPMDI based PUs. For example, HDEDI based PUs exhibited a triclinic crystal form; whereas HPMDI based PUs exhibited a hexagonal crystal lattice. In addition, canola polyol‐HDEDI PU demonstrated a higher tensile strength at break than that of canola polyol‐HPMDI, attributed to the higher degree of hydrogen bonding associated with the former sample. Nevertheless, lower Young's modulus and higher elongation in canola polyol‐HDEDI PU were obtained because of the flexibility of the long chain introduced by the HDEDI diisocyanate. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3302–3310, 2010 相似文献
53.
Summary We investigate by a statistical analysis possible correlations among the observational parameters of the γ-ray bursts: the
rise time, the decay time and spectral hardness. We discuss the physical constraints implied by the results.
To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee. 相似文献
54.
多源单汇网络资源调度路径优化探讨 总被引:1,自引:0,他引:1
在考虑队列长度的前提下 ,论文在分析多源单汇资源传输问题的基础上 ,以两源单汇网络为例 ,在资源到达终点所需时间最短约束下 ,研究、计算了最短传输时间的上下界 ,并提出了相应的算法 .论文的研究内容为进一步研究多源多汇问题建立了基础 ,提供了思路 . 相似文献
55.
A new procedure called ‘source generation’ is applied to the pfaffianized KP equation. As a result, the pfaffianized-KP equation with self-consistent sources (ESCS) is obtained. This coupled system cannot only be reduced to the pfaffianized KP equation, but also reduced to the KP equation with self-consistent sources (KPESCS). So the pfaffianized-KP ESCS can be viewed as a pfaffian version of the KPESCS, which indicates the commutativity of the ‘source generation’ procedure and pfaffianization. 相似文献
56.
Yu. G. Mateyshina U. Lafont N. F. Uvarov E. M. Kelder 《Russian Journal of Electrochemistry》2009,45(5):602-605
The study deals with the synthesis and comparison of physicochemical properties of LiFe0.5Mn1.5O4 based cathode materials synthesized by the standard ceramic and the auto-ignition method. 相似文献
57.
Mala Nath 《应用有机金属化学》2008,22(10):598-612
A comprehensive review on toxicity of organotin compounds including sources of their intake and mode of action, and cardiovascular activity of organotin compounds is presented. Further research to develop novel useful organotin compounds having hypertensive activity needs to be carried out. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
58.
Arezou Rezazadeh Josep Font-Segura Alfonso Martinez Albert Guilln i Fbregas 《Entropy (Basel, Switzerland)》2021,23(5)
This paper studies a generalized version of multi-class cost-constrained random-coding ensemble with multiple auxiliary costs for the transmission of N correlated sources over an N-user multiple-access channel. For each user, the set of messages is partitioned into classes and codebooks are generated according to a distribution depending on the class index of the source message and under the constraint that the codewords satisfy a set of cost functions. Proper choices of the cost functions recover different coding schemes including message-dependent and message-independent versions of independent and identically distributed, independent conditionally distributed, constant-composition and conditional constant composition ensembles. The transmissibility region of the scheme is related to the Cover-El Gamal-Salehi region. A related family of correlated-source Gallager source exponent functions is also studied. The achievable exponents are compared for correlated and independent sources, both numerically and analytically. 相似文献
59.
获得覆盖较宽温度和压力范围内的等离子体热力学和输运性质是开展等离子体传热和流动过程数值模拟的必要条件.本文通过联立Saha方程、道尔顿分压定律以及电荷准中性条件求解等离子体组分;采用理想气体动力学理论计算等离子体热力学性质;基于Chapman-Enskog方法求解等离子体输运性质.利用上述方法计算了压力为0.1, 1.0和10.0 atm (1 atm=101325 Pa),电子温度在300—30000 K范围内,非局域热力学平衡(电子温度不等于重粒子温度)条件下氩-氮等离子体的热力学和输运性质.结果表明压力和非平衡度会影响等离子体中各化学反应过程,从而对氩-氮等离子体的热力学及输运性质有较大的影响.在局域热力学平衡条件下,计算获得的氩-氮等离子体输运性质和文献报道的数据符合良好. 相似文献
60.
讨论了菲涅耳双棱镜实验中虚光源的位置,计算了两虚光源间的距离,并进行了实验测量,理论分析与实验相一致. 相似文献