异戊二烯-甲基丙烯酸甲酯共聚物的裂解色谱分析

]本文用裂解色谱(PGC)、裂解-色谱质谱(PY-GC/MS)和裂解质谱(PY/MS)等方法对异戊二烯-甲基丙烯酸甲酯共聚物进行了裂解研究,分离鉴定了主要裂解产物,检测出了特征裂解产物——杂二聚体和杂三聚体,以及异戊二烯的三聚体。考察了某些主要裂解产物同无规共聚物的组分含量和裂解温度之间的变化关系。建立了用裂解色谱鉴别不同共聚物和均聚混合物以及分析无规共聚物组分含量的方法。定量方法的精确度为相对标准偏差小于2％。对用均聚混合物作标样的定量可能性进行了探讨。     

High-speed chaotic communication using an optical fibre ring as a key

A chaotic communication scheme with a fibre ring inserted in the optical feedback of the transmitter laser as an additional key is proposed under anticipating synchronization. The numerical results show that the key can enhance the communication security effectively. It is theoretically safe for the communication scheme to transmit messages with a frequency beyond the relaxation oscillation frequency.     

Flexible pulses from carbon nanotubes mode-locked fiber laser

We demonstrate a flexible erbium-doped pulsed fiber laser which achieves the wavelength and pulse width tuning by adjusting an intracavity filter. The intracavity filter is flexible to achieve any of the different wavelengths and bandwidths in the tuning range. The wavelength and width of pulse can be tuned in a range of ~ 20 nm and from ~0.8 ps to 87 ps,respectively. The flexible pulsed fiber laser can be accurately controlled, which is insensitive to environmental disturbance.     

新型三齿含膦配体的Ni(Ⅱ)配合物的合成和晶体结构

A new tridentate Ni(Ⅱ) complex {Ni(H₂O)₃[Ph₂(o-Ph-N-C₇H₇N)]PO}Cl₂ was synthesized by the reaction of a new ligand Ph₂(o-Ph-N-C₇H₇N)]PO with NiCl₂ in CH₃CH₂OH. The complex was characterized by X-ray single crystal diffraction. The crystal structure of the complex belongs to monoclinic space group P2₂/n, a=1.259 28(9) nm, b=1.201 24(8) nm, c=2.039 03(14) nm, V=3.016 8(4) nm^-3, Z=4, and R₂=0.047 1, wR₂=0.120 5. And a molecular CH₂Cl₂ is filled in the crystal structure. CCDC: 241832.     

高重复频率飞秒掺镱光纤放大器

 数值分析了掺镱单模光纤放大器的最佳增益光纤长度,并在实验上对掺镱单模光纤放大器和光栅对压缩器进行了研究。以最大平均输出功率为7 mW、重复频率为25.4 MHz、脉宽为56 ps的被动锁模环形腔掺镱光纤激光器作为种子脉冲,用250 mW的976 nm单模半导体激光器分别泵浦3种不同长度的掺镱单模光纤,对种子光进行放大,并用光栅对压缩器对放大后的脉冲在不同光栅距离上进行了压缩实验研究。当掺镱单模光纤长度为1.2 m时得到了较好的放大效果,种子脉冲被放大到140 mW,相应的增益为13 dB,放大后的单脉冲能量为5.5 nJ。在光栅距离为14.1 cm时获得了最短440 fs的脉冲,压缩后的功率为43 mW,相应的峰值功率为3.8 kW。     

超短脉冲掺Yb3+光纤放大器实验研究

通过采用不同类型和不同长度掺Yb3+光纤进行被动锁模光纤放大器的实验研究.获得了最大输出功率为140 mW,单脉冲能量为5.5 nJ的超短脉冲.实验分析表明:掺杂光纤绿色荧光的产生和自吸收是影响放大器光转换效率的主要原因.绿色荧光的产生为Yb3+离子间相互作用引起合作能量转移过程,这种能量转移过程将降低光纤放大器的量子效率.     

有机硅改性聚氨酯丙烯酸酯细乳液的制备及性能

将自制的聚氨酯大单体与含乙烯基有机硅单体、丙烯酸酯进行共聚反应,通过合适的工艺条件,制备了一系列性能稳定的细乳液。研究了聚合方法、有机硅含量对共聚细乳液及胶膜性能的影响。结果表明,种子细乳液法制得的聚合物结构明确,细乳液粒径均在150 nm左右,分布指数约为0.07,有机硅的引入使乳液胶膜耐水性及耐高温性得到了明显提高。     

分数阶衍射蜂窝晶格中带隙涡旋孤子的传输与控制

基于分数阶非线性薛定谔方程,研究分数阶衍射效应下蜂窝晶格中带隙涡旋光孤子的存在性与传输特性.首先采用平面波展开法得到蜂窝晶格能带结构,其次在带隙结构中分别采用改进的平方算子迭代法、分步傅里叶法和傅里叶配置法研究含有蜂窝晶格势的分数阶非线性薛定谔方程中带隙涡旋孤子的模式及其传输特性.研究结果发现带隙涡旋孤子的传输特性受Iévy指数和传播常数的影响.在稳定区间,带隙涡旋孤子可以稳定传输,而在非稳定区间,带隙涡旋孤子会随着传输距离的增加而逐渐汇聚,失去环状结构演变为基孤子.且Lévy指数越大,带隙涡旋孤子能够稳定传输的距离越长,功率越低.此外,相邻晶格同相位两个带隙涡旋孤子与旁瓣能量相叠加,反相位两带隙涡旋孤子与旁瓣能量相抵消,传输过程中逐渐失去环状结构,演化为类偶极子模式,且受方位角调制影响而周期性旋转.在非相邻晶格处两带隙涡旋孤子,由于旁瓣影响较小,带隙涡旋孤子在传输过程中能较好地保持环状结构.     

Experimental Investigation of Chaos Synchronization in DFB Diode Lasers with Unsymmetrical Scheme

We experimentally generate high dimension chaotic waveforms with smooth spectrum using a distributed feedback （DFB） semiconductor laser with unidirectional fibre ring long-cavity feedback, and implement the stable chaos synchronization when the chaotic light is injected into a solitary DFB laser diode. The synchronization quality is investigated by time-domain and frequency-domain analysis separately, The frequency-domain analysis indicates that the synchronization has higher quality in the high frequency band. The influences of the injection strength and the frequency detuning on the synchronization are measured. Our experimental results show that the robust synchronization can be maintained with the optical frequency detuning from -11GHz to 40 GHz.     

分光光度法测定磷矿石中五氧化二磷及二氧化硅的含量

试样经碱熔，酸化后，以磷－钼－钒黄分光光度法测定五气化二磷；在草酸存在下，以抗坏血酸为还原剂，硅钼蓝法测定二氧化硅。本方法操作简单、快速，具有较好的精密度和准确度。