The existence of global attractors for a class nonlinear evolution equation

In this paper, using a new method (or framework), we establish the existence of global attractors for a class nonlinear evolution equation in , where the nonlinear term f satisfies a critical exponential growth condition.     

800 nm飞秒激光长周期光纤光栅的特性

利用800 nm飞秒激光脉冲作为光源,在标准通信单模光纤上直接刻写周期分别为100,200,300和400 m的长周期光纤光栅(LPFG),得到波长范围为1 280～1 680 nm的透射谱,分析研究了在不同刻写条件下LPFG透射谱的共振波长、透射深度和插入损耗等参数的变化。通过对比分析发现透射衰减与刻写长度、条数以及平台高度等有着一定的对应关系。优化实验参数制作出共振波长分别约为1 407,1 311,1 669,1 551 nm,透射深度分别约为24.0,22.3,27.8,23.4 dB,插入损耗分别约为2.5,1.7,3.2,2.0 dB的LPFG。     

线性耗散板方程解的衰减估计

研究了多维空间（n≥1）中线性板方程的初值问题.使用Fourier变换,得到基本解和相应的线性问题的解.对Fourier空间中线性问题的解作逐点估计,得到解算子的估计和性质,再结合能量方法,得到线性问题解的最优衰减估计.     

Structure and magnetic properties of LaFe11.5−xCoxSi1.5C0.2 compounds for magnetic refrigeration near room temperature

The influence of cobalt on the microstructural, magnetic and magnetocaloric properties of LaFe_11.5−xCo_xSi_1.5C_0.2 (x=0.50–0.85) compounds was investigated. The ingots were prepared by using a vacuum induction melting furnace. Before annealing, a large amount of 1:13 phase was distinctly observed. Nearly single 1:13 phase was obtained after annealing at 1353 K for only 3 days. The easy formation of 1:13 phase in the annealing process could be attributed to carbon doping. The Curie temperature (T_C) increases linearly with increasing the cobalt content. Although the maximum magnetic entropy changes of the compounds decrease rapidly when T_C rises from 275 to 298 K, and it decreases mildly when T_C continues to rise. Two composite refrigerants based on the compounds are proposed. Their entropy changes remains approximately constant over the temperature range from 266 to 292 K and 289 to 309 K.     

Taylor-Hadamard乘积的q-级和q-型

通过构造Taylor-Hadamard乘积,讨论了泰勒级数的增长性,获得了此Taylor-Hadamard乘积与原泰勒级数关于q-级和q-型的几个关系定理,并给出相应的例子说明了结果的正确性.     

在线裂解-气相色谱-质谱法研究灵香草浸膏的热裂解

为了研究灵香草浸膏的热裂解行为,采用在线有氧热裂解-冷阱捕集-气相色谱-质谱联用技术,模拟卷烟燃吸状态对灵香草浸膏进行了热裂解分析,并对灵香草浸膏热裂解前后的挥发性成分进行了比较分析。从灵香草浸膏的热裂解产物中共鉴定出64种成分,占总峰面积的88.27%,主要成分为高级脂肪酸及其酯类;灵香草浸膏热裂解后的挥发性成分数量多于裂解前（45个）,说明灵香草浸膏经热裂解生成了新的化合物。热裂解前后共有的化合物有20个,主要是高级脂肪酸及其酯类、新植二烯、5-（羟甲基）-2-呋喃甲醛、3-羟基-4,5-二甲基-2（5H）-呋喃酮等化合物。在线有氧裂解模式更接近烟用添加剂样品的真实裂解状态,操作简单、快捷,结果准确。     

泵浦波长对光子晶体光纤产生超连续谱的影响

采用钛宝石光参量放大器作为泵浦源,利用其输出波长可调谐性,研究了不同泵浦波长对光子晶体光纤中产生超连续谱的影响,结果表明光子晶体光纤中零色散点处的群时延和1.4 μm处的OH根离子的吸收对超连续谱的平坦度影响很大,并且泵浦波长离光纤的零色散点越远,产生的超连续谱平坦度越差,甚至在可见光区产生的各个频率峰还只是分离的,没有形成超连续谱.当泵浦波长为1.2 μm时,获得了带宽为300 nm~1350 nm的超连续谱,谱宽超过了两个倍频程.     

非线性映射具误差的迭代序列在Banach空间中的收敛问题

In this paper,the approximation problems of Ishikawa iteration with errors of fixedpoints for asymptotically nonexpansive mappings and asymptotically pseudocontractivemappings in arbitrary real Banach spaces are investigated. Some necessary condition andsufficient condition for the convergence of iterative sequences are given respectively. The resultsthus extend and improve some recent corresponding results.     

Banach空间中一类g-η-增生映象包含组的Ishikawa迭代算法

在Banach空间中引入和研究了一类含g-η-增生映象的变分包含,利用与g-η-增生映象相联系的预解算子技巧,证明了这类g-η-增生映象包含解的存在性和惟一性．对这类g-η-增生映象包含的逼近解我们也构造了一个新的Ishikawa迭代算法,并讨论了由此算法生成的迭代序列的收敛性．