一类具有时变时滞的中立型系统的稳定性分析

本文研究一类具有状态时滞和输入时滞的时变时滞线性中立型系统.首先,通过选取合适的Lya-punov-Krasovskii泛函,应用LMI方法和Lyapunov-Krasovskii稳定性定理对时滞相关的系统进行稳定性分析,并设计了相应的控制器.改进了时不变时滞线性系统方面的一些结果.最后用实例验证所得到结果.     

一类时滞系统的稳定性分析及控制器设计

研究一类具有状态时滞和输入时滞的时变时滞线性系统.首先,通过选取合适的Lyapunov-Krasovskii泛函,应用LMI方法和Lyapunov-Krasovskill稳定性定理对时滞相关的系统进行稳定性分析,并设计了相应的控制器.改进了时变时滞线性系统方面的一些结果.最后用实例验证所得到结果.     

Generation of broadly tunable picosecond mid-infrared laser and sensitive detection of a mid-infrared signal by parametric frequency up-conversion in MgO:LiNbO3 optical parametric amplifiers

Picosecond optical parametric generation and amplification in the near-infrared region within 1.361-1.656 μm and the mid-infrared region within 2.976-4.875 μm is constructed on the basis of bulk MgO：LiNbO 3 crystals pumped at 1.064 μm.The maximum pulse energy reaches 1.3 mJ at 1.464 μm and 0.47 mJ at 3.894 μm,corresponding to a pumpto-idler photon conversion efficiency of 25%.By seeding the hard-to-measure mid-infrared radiation as the idler in the optical parametric amplification and measuring the amplified and frequency up-converted signal in the near-infrared or even visible region,one can measure very week mid-infrared radiation with ordinary detectors,which are insensitive to mid-infrared radiation,with a very high gain.A maximum gain factor of about 7 脳 10 7 is achieved at the mid-infrared wavelength of 3.374 μm and the corresponding energy detection limit is as low as about 390 aJ per pulse.     

Generation of broadly tunable picosecond mid-infrared laser and sensitive detection of a mid-infrared signal by parametric frequency up-conversion in MgO:LiNbO₃ optical parametric amplifiers

Picosecond optical parametric generation and amplification in the near-infrared region within 1.361-1.656 μm and the mid-infrared region within 2.976-4.875 μm is constructed on the basis of bulk MgO:LiNbO 3 crystals pumped at 1.064 μm.The maximum pulse energy reaches 1.3 mJ at 1.464 μm and 0.47 mJ at 3.894 μm,corresponding to a pumpto-idler photon conversion efficiency of 25%.By seeding the hard-to-measure mid-infrared radiation as the idler in the optical parametric amplification and measuring the amplified and frequency up-converted signal in the near-infrared or even visible region,one can measure very week mid-infrared radiation with ordinary detectors,which are insensitive to mid-infrared radiation,with a very high gain.A maximum gain factor of about 7 × 10 7 is achieved at the mid-infrared wavelength of 3.374 μm and the corresponding energy detection limit is as low as about 390 aJ per pulse.     

High quality beam shaping by square soft-edge diaphragm combined with liquid crystal spatial light modulator

<正>The square soft-edge diaphragm with round angle is designed by Matlab,and is sent to a liquid crystal spatial light modulator by the computer.In order to obtain precompensation for the following laser system, local diaphragm transmission can be adjusted by feedback signals of surface-channel charge-coupled device (SCCD).This method can reduce the diffraction effect and realize no modulation,high stability,high homogeneity,and large scale laser beam.Several parameters of soft-edge diaphragms which affect the laser beam quality are studied systematically,and the optimized values are obtained.The method can avoid the serious modulation of hard edges and provide soft-edge diaphragms of different shapes in a fast and convenient way for the large scale laser beam system.     

矿区生产经营系统动力学模型及仿真

章建立了矿区生态经营系统动力学模型，阐述了所研究和实验的各种策略，及在此基础上提出的多个方案，以供矿区领导根据实际条件做出较科学的规划。     

二次函数y=ax~2 bx c的有趣性质及其应用

二次函数ｙ＝ａｘ２＋ｂｘ＋ｃ的有趣性质及其应用四川省内江市市中区永安镇初级中学邱力争二次函数ｙ＝ａｘ２＋ｂｘ＋ｃ（ａ≠０）的图象和性质是我们比较熟悉的中学数学内容，根据二次函数的自变量和函数值间的关系我们将研究二次函数的有趣的一些性质，使得二次函数的...     

离子色谱法测定丁二酸合成电解液中马来酸和丁二酸

采用离子色谱法测定丁二酸合成电解液中原料马来酸和产物丁二酸的含量。试样经Ion Pac AG19保护柱及Ion Pac AS19分析柱分离,以25 mmol·L^-1氢氧化钾溶液为淋洗液,采用抑制电导器检测。马来酸和丁二酸的质量浓度在1.0～10 mg·L^-1范围内与峰面积与峰高均呈线性关系。方法可用于测定合成丁二酸生产过程的不同时段溶液（起始、结束和母液）中马来酸和丁二酸的含量,有助于实现丁二酸的连续式电解合成工艺路线。     

在十二烷基磺酸钠存在下4—（2—吡啶偶氮）—邻苯二酚分光光度法测定铁（Ⅲ）

1引言目前已有多种光度分析用于试样中的小量和痕量铁的测定，作者观察到在酸性介质中，十二烷基磺酸钠（NaLS）存在下可使4-（2-吡啶偶氮）-邻苯二酚[简称PAPC]与Fe（Ⅲ）的反应灵敏度提高，选择性增强，对比度高达123nm，从而建立了测定铁（Ⅲ）的新方法。2实验部分2．1主要仪器及试剂TU－1201型紫外分光光度计，722型分光光度计，铁标准溶液：10mg／L的标准溶液，PAPC（自制）：1．0×10-3mol／L，十二烷基磺酸钠（NaLS）：1％水溶液，HAc－NaAc缓冲溶液：pH＝4．0，其它试剂均为AR级。2．2实验方法吸取一定量的铁标准溶液于2…     

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.