炸药驱动强电流短路开关的研

由于电磁轨道炮和其它强电流装置中短路运行的需要,研制了一种条形炸药驱动的大电流闭合开关。利用爆炸成型技术使金属飞板负电极在炸药部件作用下,大面积地同时切断绝缘薄膜,嵌入另一电极模槽中构成牢固的接触。开关的绝缘强度大于30kV,电感(包括传输线)小于50nH,最大峰值电流达到400kA,闭合接触电阻小于0.1m,动作时间约为14us。对于开关的爆轰,撞击及变形过程进行了一维和二维数值模拟计算,并提出了一个描述爆炸开关行为的经验模型。利用这个模型进行电磁轨道炮整个系统的数值模拟,同实验结果符合较好。     

ANALYSIS OF FRICTION INDUCED VIBRATION UNDER THE ACTIVE DISTURBANCE REJECTION CONTROL FRAMEWORK 1)

自抗扰控制(active disturbance rejection control, ADRC)是一种具有两自由度控制结构的工程化方法, 由于其能够直观有效地处理多种扰动, 近些年来在许多机电系统上得到了成功应用. 当采用ADRC对带有摩擦力的机电系统进行调节时, 可能会产生极限环振动. 目前, 还没有ADRC框架下摩擦力振动精确分析的相关工作. 因此, 本文采用非线性动力学系统的分析工具对这一问题进行研究. 首先, 考虑两种典型摩擦力模型, 静态切换模型和动态LuGre 模型, 对一类二阶运动系统设计不同阶次的ADRC, 得到控制器的等效形式, 并揭示出与比例积分微分(proportional-integral-derivative, PID)控制之间的联系. 然后, 采用打靶法结合拟弧长延拓方法求解系统中的极限环, 并根据Floquet理论判断极限环的稳定性、可能出现的分岔以及分岔类型. 此外, 通过雅克比矩阵和近似数值方法对系统平衡点集的局部稳定性进行了分析. 最后, 通过数值计算研究了摩擦力模型和参数、ADRC阶次和参数对极限环和平衡点集的影响. 计算结果表明, 决定摩擦力Stribeck效应负斜率的参数$\beta$作用较大. 当$\beta>1$时, 两种摩擦力模型下的闭环系统呈现出相同的特性, 极限环会出现环面折叠分岔(cyclic fold bifurcation, CFB)且平衡点集是局部稳定的. 然而当$\beta<1$时, 两种闭环系统呈现出完全不同的特性. 此外, 不同阶次的ADRC在极限环的存在性和稳定性、平衡点集的稳定性上面的结论是相同的, 而低阶次的ADRC能够更好地解决摩擦力补偿和稳定鲁棒性之间的矛盾问题. 这些结论对实际现象的理解、ADRC阶次的选择以及参数整定提供了一定指导.     

Acid-induced conformational alteration of cis-preferential aromatic amides bearing N-methyl-N-(2-pyridyl) moiety

A series of cis-preferential aromatic N-methyl amides was designed and synthesized, and acid-induced conformational alteration of these compounds was investigated by means of NMR measurements in solution and X-ray crystal structure analysis. Compounds with a terminal N-methyl-N-(2-pyridyl) amide unit showed acid-induced conformational change from cis to trans, while those with a terminal N-methyl-2-pyridinecarboxamide unit showed a change of the carbonyl orientation from anti to syn with retention of cis conformation.     

Ratiometric fluorescent Zn chemosensor constructed by appending a pair of carboxamidoquinoline on 1,2-diaminocyclohexane scaffold

By appending a pair of carboxamidoquinoline pendants onto 1,2-diaminocyclohexane scaffold via N-alkylation, multifunctionalized ACAQ was designed and synthesized as a water soluble fluorescent ratiometric chemosensor for Zn²⁺. In 50% aqueous methanol buffer pH 7.4 solution, upon excitation at 316 nm, ACAQ (5 μM) displayed a selective ratiometric fluorescence changes with a shift from 410 to 490 nm in response to the interaction with Zn²⁺. After binding with 1 equiv of Zn²⁺, ACAQ exhibited a 12-fold enhancement in I₄₉₀/I₄₁₀ characterized by a clear isoemissive point at 440 nm. The metal sensor binding mode was established by Job’s plot and the combined fluorescence and ¹H NMR spectroscopic method. The selectivity of the probe toward biological relevant cations and transition metal ions was proven to be good. In addition, the interference caused by Cu²⁺ and Cd²⁺ in the quantitation of Zn²⁺ can be completely eliminated by the use of diethyldithiocarbamate as the screening agent. Exploitation of ACAQ as the sensing probe, ratiometric determination of Zn²⁺ with the limit of detection (LOD) at 28.3 nm can be realized. In addition, the unique responsive properties of the probe toward Fe³⁺ and Zn²⁺ were used to construct a fluorescent switch. The membrane permeability of ACAQ to living cells and bio-imaging of Zn²⁺ were demonstrated.     

Off-on-off luminescent switching of a dye containing imidazo[4,5-f][1,10]phenanthroline

A new acid-base fluorescent switch containing both imidazo[4,5-f][1,10]-phenanthroline and triphenylamine groups has been synthesized.Its fluorescence emissions and absorptions can be reversibiy changed through protonation/deprotonation of imidazole and amine moiety by controlling the intramolecular charge transfer(ICT) process,leading to off-on-off fluorescent molecular switching.     

Highly sensitive detection of S-nitrosylated proteins by capillary gel electrophoresis with laser induced fluorescence

S-nitrosylated proteins are biomarkers of oxidative damage in aging and Alzheimer's disease (AD). Here, we report a new method for detecting and quantifying nitrosylated proteins by capillary gel electrophoresis with laser induced fluorescence detection (CGE-LIF). Dylight 488 maleimide was used to specifically label thiol group (SH) after switching the S-nitrosothiol (S-NO) to SH in cysteine using the "fluorescence switch" assay. In vitro nitrosylation model-BSA subjected to S-nitrosoglutathione (GSNO) optimized the labeling reactions and characterized the response of the LIF detector. The method proves to be highly sensitive, detecting 1.3 picomolar (pM) concentration of nitrosothiols in nanograms of proteins, which is the lowest limit of detection of nitrosothiols reported to date. We further demonstrated the direct application of this method in monitoring protein nitrosylation damage in MQ mediated human colon adenocarcinoma cells. The nitrosothiol amounts in MQ treated and untreated cells are 14.8±0.2 and 10.4±0.5 pmol/mg of proteins, respectively. We also depicted nitrosylated protein electrophoretic profiles of brain cerebrum of 5-month-old AD transgenic (Tg) mice model. In Tg mice brain, 15.5±0.4 pmol of nitrosothiols/mg of proteins was quantified while wild type contained 11.7±0.3 pmol/mg proteins. The methodology is validated to quantify low levels of S-nitrosylated protein in complex protein mixtures from both physiological and pathological conditions.     

一种应用于CMOS图像传感器的电容阵列PGA研究

研究了一种应用于1 024×1 024CMOS图像传感器中的温度计码电容阵列型可编程增益放大器（PGA）。该PGA采用开关电容阵列结构,通过改变输入与反馈电容值,实现了0～18dB的增益;同时,该PGA具有结构简单、电容阵列面积小、带宽大和反馈系数大等特点,其增益带宽50MHz、总谐波失真（THD）小于50dB。该PGA的信号处理能力完全满足12MHz速率、69dB动态范围CMOS图像传感器内部集成ADC对模拟输入信号的要求。     

Synthesis of azo benzothiazole polymer and its application of 1 × 2 Y-branched and 2 × 2 Mach–Zehnder interferometer switch

The azo benzothiazole polyurethane–urea (ABPUU) was synthesized from chromophore molecule 4-[(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3-diamine NBDPD, polyether polyol (NJ-210) and isophorone diisocyanate (IPDI). The structure, thermal property, mechanical property and physical property were characterized and investigated. The refractive index (n) and thermo-optic coefficient (dn/dT) of ABPUU was determined at different temperature and wavelength (532 nm, 650 nm and 850 nm) using attenuated total reflection (ATR) technique. Using the CCD digital imaging devices, transmission loss of ABPUU was measured. A 1 × 2 Y-branched and 2 × 2 Mach–Zehnder interferometer (MZI) switch with two rib waveguides, dual driving electrodes and two critical 3-dB couplers polymeric thermo-optic switches based on thermo-optic effect of prepared ABPUU were designed and simulation. The power consumption of the Y-branched switch is less than 0.84 mW. The Y-branched and MZI switching rising and falling times obtained are 0.8 ms and 0.2 ms, respectively.     

量子信令交换机模型设计及性能分析

本文提出了量子信令交换机的模型, 该交换机由经典信息控制模块、交换控制模块和量子交换模块三部分组成. 经典控制模块负责将纠缠初态信息传送给纠缠测量及交换单元并更新路由信息. 交换控制模块实现通路选择, 为纠缠对的分发提供通路. 量子交换模块制备纠缠对, 进行Bell态的测量, 完成纠缠交换. 量子信令交换机可以实现多用户间的信令传输及局域网通信. 通过对交换机的性能分析与仿真, 结果表明该交换机结构简单、安全保密、便于扩展、时延小, 对于构建量子通信网有很好的支撑作用. 关键词： 量子通信 量子信令网 量子信令交换机 纠缠交换     

一种全光开关及任意比能量输出光分束器的设计

基于光子晶体非线性Kerr效应设计了一种结构简单的任意比能量输出光分束器, 通过控制抽运光的强度来控制端口能量输出比. 该结构还可以实现控制光传输的动态开关作用, 并且具有插入损耗低、无串扰、信号光的开/关两个状态下的透射率相差非常大的特点, 因此该光开关具有很高的开关比. 关键词： 全光开关 光分束器 非线性Kerr效应 光子晶体