单模光纤水听器声压灵敏度的研究

光纤水听器是-种新型的声信号探测器。声压灵敏度是它的重要技术指标。70年代末,Peter和Price等人提出了声光转换的理论模型,Price导出了单模光纤水听器的声压灵敏度公式。本文,根据弹性振动理论和光弹理论,对Price公式加以推广,导出了宽频带中适用的新的声压灵敏度公式,并指出Price公式只是新得出的公式在低频声信号下的表达式。     

脉冲平面波斜入射旋转对称体电磁散射的FDTD算法

提出一种应用时域有限差分算法求解脉冲平面波斜入射时旋转对称体散射问题的方法.对斜入射脉冲平面波在圆柱坐标系下进行分解、应用总场/散射场连接边界、PML吸收边界条件.通过与矩量法分析结果的比较,验证了该方法的有效性.     

Multiple coexisting attractors of the serial–parallel memristor-based chaotic system and its adaptive generalized synchronization

Nonlinear Dynamics - The nonlinear circuit with serial–parallel memristors shows special internal characteristics and external performance, which indicates that the serial–parallel...     

The mechanism of switching combination synchronization for three distinct nonautonomous systems under sinusoidal constraints

Nonlinear Dynamics - In this paper, the mechanism of switching combination synchronization the controlled Duffing oscillator with Van der Pol system and Pendulum system is studied. Based on the...     

Copper‐Catalyzed Aerobic Oxidative Ring Expansion of Isatins: A Facile Entry to Isoquinolino‐Fused Quinazolinones

A copper‐catalyzed aerobic oxidative ring expansion reaction of isatins with 1,2,3,4‐tetrahydroisoquinoline for the synthesis of tetracyclic quinazolinones has been developed. This reaction is performed smoothly under simple conditions to give the corresponding products in moderate to good yields with good functional group tolerance. The capacity of the resultant 5H‐isoquinolino[1,2‐b]quinazolin‐8(6H)‐one for a range of palladium‐catalyzed directing C—H activation has been further demonstrated, thus giving a broader access to diverse tetracyclic quinazolinones.     

Palladium-catalyzed oxidative sp2 C-H bond acylation with alcohols

An efficient method was developed for the direct acylation of arene sp(2) C-H bonds with alcohols using palladium chloride as a catalyst and peroxide as the oxidant. The alcohols were oxidized to their corresponding aldehydes in situ and efficiently coupled with 2-arylpyridines to give aryl ketones in chlorobenzene.     

负载钯纳米粒子聚电解质空心微球的制备及其还原对硝基苯酚的催化活性

用表面引发原子转移自由基聚合法(SI-ATRP)在二氧化硅纳米粒子表面接枝聚碘化甲基丙烯酸三甲基胺基乙酯(PMETAI),原位还原静电吸附的PdCl62-后刻蚀除去二氧化硅模板,成功制备了Pd纳米粒子复合聚电解质空心微球(air@PMETAI@Pd)。 用透射电子显微镜(TEM)、红外光谱仪(FTIR)、能谱仪(EDX)、热重分析仪(TGA)等技术手段对所制备的空心微球进行表征。 结果表明,Pd纳米粒子均匀负载在聚电解质微球上,其直径约为(1.5±0.2) nm。 将负载Pd纳米粒子的微球作为催化剂应用于硼氢化钠还原4-硝基苯酚反应,显示出很好的催化效果且具有较好的回收利用性。     

Synthesis and third-order nonlinear optical property of poly（urethane-imide）

The poly（urethane-imide） （PUI） which uses isophorone diisocyanate, dispersed red 19 （DR-19）, and py- romellitic dianhydride is synthesized. The PUI is characterized by Fourier transform infrared （FT-IR） spectroscopy, differential scanning calorimetry （DSC）, and thermogravimetric analysis （TGA）. The results of DSC and TGA indicate that the PUI exhibits high thermal stability up to its glass-transition temperature of 209 ℃ and 5° heat weight loss temperature of 296℃. The fluorescence spectra of PUI and DR-19 are measured, showing that the fluorescence effect of PUI is very similar to that of DR-19 except for the light decrease of fluorescence intensity, which indicates that the fluorescence effect of PUI is generated by the azobenzene groups in its macromolecular chains. The maximum molar absorption coefficient, absorp- tion wavelength, and chromophores density are measured and used to calculate the third-order nonlinear optical coefficient X（3） to be 3.96×10^-13 esu. The nonlinear refractive index coefficient and molecular hyperpolarizabilitv of PUI are also obtained. PUI is oroved to have an excellent ootical Performance.     

免疫相关EST-SSRs标记筛选及其在大菱鲆异源雌核发育子代遗传分析中的应用

本研究对大菱鲆EST数据库中12 434条序列进行微卫星搜索,共搜索出831条EST-SSR序列,其中l6条为明确标注免疫相关功能的基因序列.根据此l6条EST-SSR序列设计引物,经过PCR扩增检测和反应条件的优化,最终筛选出9对扩增效果理想的EST-SSR标记对大菱鲆减数分裂雌核发育二倍体子代进行遗传变异检测,结果表明:在Scoph-2-1、Scoph-7-1、Scoph-10-1微卫星位点上大菱鲆亲本和雌核发育二倍体子代均为纯合基因型,其余6个微卫星位点(Psetta-1-1、Psetta-1-2、Psetta-3-1、Psetta-3-2、Scoph-4-1、Scoph-6-1)在大菱鲆雌核发育二倍体仔鱼群体中的观测杂合度≥0.700,期望杂合度0.460,平均期望杂合度为0.503.大菱鲆减数分裂雌核发育二倍体还显示出较高的重组率,平均重组率为89%;综合上述结果推断,9个免疫相关EST-SSRs标记可有效地用于分析大菱鲆减数分裂雌核发育二倍体子代的遗传变异;6个位点的重组率计算结果能够为今后对大菱鲆的着丝粒进行精确定位提供依据.     

Realizing reliable logic and memory function with noise-assisted Schmitt trigger circuits

Schmitt trigger is a comparator circuit with hysteresis, implemented by applying positive feedback to a noninverting input. Recently, it has been verified that noise under certain condition can help nonlinear circuit to realize reliable logical stochastic resonance (LSR). In this letter, we demonstrate that, without any modifications, Schmitt trigger can operate flexibly both as logic operation and latch operation in an optimal noise range. In traditional Schmitt trigger, the hysteresis is designed for resisting noise. In the new design, the hysteresis tends to enhance the LSR effect in Schmitt trigger with the help of noise and helps the system to perform better at higher noise levels. Thus, our results extend the application scope and generality of the traditional Schmitt trigger.