Structural effects of multiple-bonds on aggregating tendencies of long-chain esters

The kinetics of the hydrolysis of p-nitrophenyl esters of three types of single-chain carboxylic acids, namely, saturated, olefinic and acetylenic, was investigated in two aquiorgano binary solvent systems, DMSO-H₂O and dioxane (DX)-H₂O. The ester probes used are: octanoic (C8), dodecanoic (C12) , stearic (C18) , oleic (C18-ol) , elaidic (C18-el ) and stearolic (C18-st). The order of measured CAgC values is: C18-ol>C18-el>C18>C18-st, whereas the order of decreasing magnitude of the observed hydrolytic rate constants of the monomeric species (k_m) is: C18>C18-el>C18-ol> C18-st. These rather unanticipated results are discussed.     

Theoretical analysis of thermal effects in fiber laser from the moment when pump is turned on to steady-state

A theoretical analysis of the pump-induced temperature change and associated thermal phase shift occurring in a fiber laser is presented. The temperature rise and thermal phase shift from the moment when pump is turned on to steady-state in fiber lasers, such as Yb-doped fiber laser, are numerical calculated.With the same parameters, the numerical solution is in good agreement with the finite-element (ANSYS software) simulation.     

KrF准分子激光激发掺锗光纤折射率扰动的非线性过程

本文采用了一种简单的功率监测法,观察了KrF准分子激光对掺锗光纤折射率影响的非线性过程。观察到子纤芯折射率扰动过程中非稳定现象、饱和现象和折射率扰动的非线性。     

The Existence of Periodic Orbits for Higher Dimensional Autonomous Systemswith Small Perturbations

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Combined-modality treatment of adductor spasmodic dysphonia with botulinum toxin and voice therapy

A combined-modality treatment program consisting of botulinum toxin injection (Botox) and voice therapy was used to treat 17 subjects diagnosed with adductor spasmodic dysphonia (ADD SD). Ten subjects with ADD SD served as the control and were given Botox only. Voice therapy after Botox injection was directed toward reducing the hyperfunctional vocal behaviors, primarily glottal overpressure at voice onset and anterior-posterior squeezing. The results indicated that subjects who underwent combined-modality treatment maintained significantly higher mean airflow rates for significantly longer periods. Moreover, there was a carryover effect in these patients when they received Botox only. Adductor spasmodic dysphonia is treated most effectively when intrinsic laryngeal muscle spasms are reduced or eliminated by Botox injection and extrinsic hyperfunctional vocal behaviors are treated with voice therapy     

Synthesis and biomimetic rearrangement of a chiral diterpene dioxide

As pan of a biomimetic approach towards me marine triterpene teurilene (2), the synthesis of the chiral diepoxide 3 is described. Aiming at the synthesis of the squalene tetraepoxide 1, double Sharpless epoxidation led to the intermediate bisglycidic alcohol 7 being subject to a stereochemical analysis.     

Ga1-xInxAs/InAsyP1-y/InP异质结的MOCVD生长及表征

Ga1-xInxAs(x>0.53)材料是未来长距离低损耗光纤通信的理想光源材料和探测器材料之一.我们采用水平常压MOCVD系统,在InP衬底上成功地生长了Ga1-xInxAs(x>0.53)/InAsyP1-y/Inp异质结材料.其中InAs1-yPy为组份阶梯变化的多层结构.由样品的(400)面X光衍射结果测定了各层组份.由二次离子质谱(SIMS)得到了样品剖面组份变化结果,证明InAs1-yPy层组份为阶梯状变化的.通过对光致发光结果和X光衍射结果比较,可以看到,InAsyP1-y层通过位错和弹性畸变二种方式来释放或积累Ga1-xInxAs与InP间的失配应力,从而减少了Ga1-xInxAs中的失配位错.有效地改善了Ga1-xInxAs的质量.已获得了x高达0.94表面光亮的Ga1-xInxAs/InAs1-yPy/InP异质结材料.     

单扫描示波极谱测定痕量银

本文首次提出了运用单扫描极谱直接测定银的方法。在含N-烯丙基-N′-对苯磺酸钠硫脲及四乙烯五胺的硼砂缓冲液中,银离子在-0.66V(相对饱和甘汞电极)有一灵敏还原波。运用经典极谱或单扫描极谱,此波均可用于微量银的定量测定。“银波”的单扫描示波极谱波可在5×10~(-7)～3×10~(-5)mol/L范围内检测银。方法已用于废定影液中银含量的分析,结果满意。