4-乙烯基吡啶-镍(钴)及丙烯酰胺-镍(钴)的制备、结构、聚合及聚合物的催化性能

制备了4-乙烯基吡啶-镍(钴)和丙烯酰胺-镍(钴)络合物并研究了它们的结构。在自由基引发剂的作用下,4-乙烯基吡啶-镍可进行溶液聚合,也可与苯乙烯共聚合,测定了单体的竞聚率。所得的聚(4-乙烯基吡啶-镍)及聚(4-乙烯基吡啶-钴)以NaBH_4还原后可作为一些有机化合物的加氢催化剂。由IR及XPS分析说明在丙烯酰胺-镍络合物中,与镍离子发生了络合作用的是羧基上的氧原子。     

Influences of finite gain bandwidth on pulse propagation in parabolic fiber amplifiers with distributed gain profiles

The evolutions of the pulses propagating in decreasing and increasing gain distributed fiber amplifiers with finite gain bandwidths are investigated by simulations with the nonlinear Schr¨odinger equation. The results show that the parabolic pulse propagations in both the decreasing and the increasing gain amplifiers are restricted by the finite gain bandwidth. For a given input pulse, by choosing a small initial gain coefficient and gain variation rate, the whole gain for the pulse amplification limited by the gain bandwidth may be higher, which is helpful for the enhancement of the output linearly chirped pulse energy. Compared to the decreasing gain distributed fiber amplifier, the increasing gain distributed amplifier may be more conducive to suppress the pulse spectral broadening and increase the critical amplifier length for achieving a larger output linearly chirped pulse energy.     

Influences of finite gain bandwidth on pulse propagating in parabolic fiber amplifiers with distributed gain profiles

The evolutions of the pulses propagating in decreasing and increasing gain distributed fiber amplifiers with finite gain bandwidths are investigated by simulating with the nonlinear Schrödinger equation. The results show that the parabolic pulse propagations in both the decreasing and the increasing gain amplifiers are restricted by the finite gain bandwidth. For a given input pulse, by choosing small initial gain coefficient and gain variation rate, the whole gain for the pulse amplification limited by the gain bandwidth may be higher, which is helpful to the enhancement of the output linearly chirped pulse energy. Compared to the decreasing gain distributed fiber amplifier, the increasing gain distributed amplifier may be more conducive to suppress the pulse spectral broadening and increase the critical amplifier length for achieving a larger output linearly chirped pulse energy.     

312 MHz,compact all-normal-dispersion Yb:fiber ring laser with an integrated WDM-ISO

A compact and stable all-normal-dispersion mode-locked ring fiber laser with the repetition rate of 312 MHz is obtained with a wavelength-division multiplexing isolator. The compressed pulse is nearly transform-limited and the pulse width is 118 fs. It exhibits an optical efficiency of 50% and the maximum output power is about 205 m W with a 410 m W pump.     

Supercontinuum generated in all-normal dispersion photonic crystal fibers with picosecond pump pulses

The supercontinuum (SC) generation in all-normal dispersion (ANDi) photonic-crystal fiber (PCF) pumped by high power picosecond pulses are investigated in this paper. Our results show that an octave SC may be achieved by pumping the ANDi PCF with picosecond pump pulses. However, the PCF length required may have to be lengthened to several tens of centimeters, which is much longer than that with femtosecond pump pulses. The relatively long PCF gives rise to much higher Raman gain and stronger Raman frequency shift compared to those with femtosecond pump pulses, which in turn not only cause a distorted temporal waveform and an un-flattened spectrum, but also severely degrade the coherence of the generated SC.     

耦合广义非线性薛定谔方程的相互作用表象龙格库塔算法及其误差分析

本文通过表象变换, 将耦合广义非线性薛定谔方程 (C-GNLSE) 变换成相互作用表象中的向量方程, 再利用向量形式的4阶龙格-库塔迭代格式, 建立了一种在频域内求解C-GNLSE的同步更新迭代算法. 通过将该向量形式的相互作用表象中的4阶龙格-库塔 (V-JH-RK4IP) 算法应用于高双折射光子晶体光纤中超连续谱产生的数值模拟, 验证了算法的有效性, 通过与现有其他典型算法的比较, 表明以V-JH-RK4IP算法求解C-GNLSE具有最高的计算精度和计算效率. 关键词： 耦合广义非线性薛定谔方程(C-GNLSE) 相互作用表象 4阶龙格-库塔算法 超连续谱产生     

基于中点模型的北京地铁暗挖车站建设期环境影响评价

以地铁暗挖车站建设期为研究对象,以生命周期评价为基本方法,基于中点模型中的环境影响科学中心方法,选取全球变暖(GWP)、酸化(AP)、水体富营养化(EP)、非生物资源消耗(ADP)、人体毒性(HTP)、光化学烟雾(POCP)六个中点环境破坏类型,根据地铁暗挖车站的特点,确定地铁车站建设期的目的与范围,建立地铁暗挖车站建设期环境影响评估模型.通过对实际工程的环境影响实例分析发现,二次衬砌在车站主体结构建设期的环境影响中占50%以上;地铁暗挖车站建设期内,各环境影响因素从大到小依次为GWP、AP、POCP、EP、ADP和HTP.研究成果为地铁车站建设期的节能减排工作提供了有力的数据支持.     

考虑消纳效益的多能源枢纽荷源协调优化方法

为进一步挖掘能源互联网多能源互补的潜力,提高能源系统的运行收益,降低运行成本,提出了一种考虑消纳效益的多能源枢纽荷源协调优化方法。考虑多能源系统的约束条件,依据最小化住宅能量枢纽运行总成本构建住宅能量枢纽模型,以最大化工业能量枢纽运行总收益为目标构建工业能量的枢纽模型。根据上述两层模型的约束条件得到荷源协调优化运行中存在的问题,采用多目标加权寻优算法,设计多目标混合整数线性规划模型,实现荷源协调优化。仿真实验结果表明:所设计的考虑消纳效益的多能源枢纽荷源协调优化方法可促进可再生能源的消纳,降低多能源枢纽的运行成本,有效减少开销,提高能源系统的运行收益,为多能源枢纽的经济运行及荷源协调优化提供了新的技术途径。     

4—乙烯基吡啶—镍（钴）及丙烯酰胺—镍（钴）的制备、结构、聚合及聚合物

制备了4－乙烯基吡啶－镍（钴）和丙烯酰胺－镍（钴）络合物并研究了它们的结构。在自由基引发剂的作用下，4－乙烯基吡啶－镍可进行溶液聚合，也可与苯乙烯共聚合，测定了单体的竞聚率。所得的聚（4－乙烯基吡啶－镍）及聚（4－乙烯基吡啶－钴）以NαBH4还原后可作为一些有机化合物的加氢催化剂。由IR及XPS分析说明在丙烯酰胺－镍 合物中，与镍离子发生了络合作用的是碳基上的氧原子。