基于吐温-姜黄素复合物的荧光探针检测脂肪酶活性

本实验以姜黄素作为信号探针,吐温作为脂肪酶的底物和包裹姜黄素的载体,建立了一种检测脂肪酶活性的荧光法.实验发现,采用0.3 mmol/L吐温40,25 μmol/L姜黄素,并且脂肪酶水解吐温40的时间为35 min时,姜黄素的荧光强度变化值与脂肪酶浓度在0.002 ～0.05 mg/mL和0.05～0.25 mg/mL范围内呈现线性关系,检出限为0.6 mg/L (S/N=3).此探针在高通量检测脂肪酶活性以及与脂肪酶相关疾病检测领域中有较好的应用前景.     

大口径平行光管光学设计和容差分析

大口径平行光管是光学系统检验的关键装置。大口径平行光管光学系统采用球面共轴系统结构，主镜为妒l500球面反射镜，次镜为无光焦度校正板组件，通过优化设计这种系统能够较好地消除系统像差。在设计视场内平行光管系统对532，6328，1319nm三个波长的波像差均小于M40(2=0．6328μm)，不同视场对应的Strehl-ratio分别为0．9993，0．9963和0．9846。如图1所示。     

超声脉冲回波谱分析全自动化测量系统的研制

本文报道了一种全自动化超声脉冲回波谱分析测量系统。该系统具有对超声回波信号进行快速选择性采样、存贮、数字分析与处理及微机程序软件控制三维机械扫描等功能,可对生物组织样品的超声衰减系数谱、背向散射系数谱及回波谱自相关进行测量与分析。对一系列哺乳动物软组织样品所做的实验研究表明,该测量系统给出了令人满意的研究结果。     

脉冲CO2激光器峰值功率的增益饱和现象

 从理论和实验的角度分析了在腔损耗调制状态下,当调制速度与CO₂激光转动能级间的弛豫速度相当时,激光器输出脉冲峰值功率与增益系数间存在的非线性特性：峰值功率随增益系数的增加,存在饱和现象。这种特性是CO² B-类激光器的特点,实验和理论模拟结果一致。     

溴过氧化物酶催化环己烯环氧化反应

研究了分离自珊瑚藻(Corallina officinalis)的溴过氧化物酶在水-有机两相体系中催化环己烯环氧化的反应.考察了氧化剂种类与添加方式、pH、反应温度、酶浓度及KBr浓度等条件对环氧化反应的影响.最佳反应条件为:反应温度55℃,在含有50mmol/LKBr和32U/ml溴过氧化物酶的pH6.0的Tris-HCl缓冲液中,每隔10min补加50μl的2.29mol/LH2O2.在此反应条件下,环氧环己烷的收率达到41.5%,选择性为82.2%.     

损耗调制CO2激光脉冲的噪声特性

由于自发辐射噪声的涨落,CO2激光器的脉冲峰值强度与时间延迟密切相关。理论和实验研究发现,对于典型的B类CO2激光器．在损耗调制情况下,当脉冲峰值出现在最低腔损耗to之前时,初始自发辐射噪声越大,相对于阈值点的第一个渡跃时间tFP越小,对应的峰值强度越小;当脉冲峰值出现在最低腔损耗to之后时,初始自发辐射噪声越大,相对于阈值点的第一个渡跃时间tFP越小,对应的峰值强度则越大。     

低介电常数非晶氟碳薄膜光谱表征

以C4F8和CH4为原料气,通过等离子体增强化学气相淀积的方法制备了非晶氟碳薄膜,在实验条件下所得薄膜的介电常数为2.3。薄膜的傅里叶变换红外光谱表明该薄膜中除了含有CFn(n=1-3）基团外,还含有少量的C=O,C=C等不饱和双键,没有迹象表明C-H和O-H的存在。X射线光电子能谱进一步证明了薄膜中的碳元素有六种不同的化学状态分别为CF3（8%）、CF2（19%）,CF（26.7%)、C↓-—CF。（42.5%),C↓-—C(3.3%)和C=O（0.5%),表明薄膜中大约54%的碳原子与氟成键,大约43%的碳原子不是与氟成键,而是与碳氟基团CFn中的碳原子成键,毗连的两个碳原子上均没有氟参与成键的几率很小。     

铈、铽共掺杂的硼磷酸镧磷光体的制备研究

1 引言 三基色荧光灯中绿色发光材料对灯的光效和光通维持率起主要作用,因此探索合成高效绿色发光材料具有重要的意义.虽然其制备方法有共沉淀法、溶胶-凝胶法、微波热效应法,但适合大批量生产的仍是高温固相反应法.磷酸盐体系绿粉因其合成温度适中、发光亮度高、色坐标X值较大而倍受研究者亲睐,但发光的热稳定性较差.传统的方法是以磷酸氢二铵和稀土氧化物为原料在高温下反应,这样会有氧化磷蒸发,导致磷酸根与稀土元素的比例无法控制.本文采用自制的高纯度磷酸硼(熔点高于1600℃)不仅可以克服上述缺点,还可以使反应在弱还原气氛或惰性气氛中进行[1,2].     

Liquid-phase and solid-phase microwave irradiations for reduction of graphite oxide

In this paper, two microwave irradiation methods：（i） liquid-phase microwave irradiation（MWI） reduction of graphite oxide suspension dissolved in de-ionized water and N, N-dimethylformamide, respectively, and（ii） solid-phase MWI reduction of graphite oxide powder have been successfully carried out to reduce graphite oxide. The reduced graphene oxide products are thoroughly characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectral analysis, Raman spectroscopy, UV-Vis absorption spectral analysis,and four-point probe conductivity measurements. The results show that both methods can efficiently remove the oxygencontaining functional groups attached to the graphite layers, though the solid-phase MWI reduction method can obtain far more efficiently a higher quality-reduced graphene oxide with fewer defects. The I（D）/I（G） ratio of the solid-phase MWI sample is as low as 0.46, which is only half of that of the liquid-phase MWI samples. The electrical conductivity of the reduced graphene oxide by the solid method reaches 747.9 S/m, which is about 25 times higher than that made by the liquid-phase method.     

Atomic crystals resistive switching memory

Facing the growing data storage and computing demands, a high accessing speed memory with low power and non volatile character is urgently needed. Resistive access random memory with 4F~2 cell size, switching in sub-nanosecond cycling endurances of over 10~(12) cycles, and information retention exceeding 10 years, is considered as promising nex generation non-volatile memory. However, the energy per bit is still too high to compete against static random acces memory and dynamic random access memory. The sneak leakage path and metal film sheet resistance issues hinder th further scaling down. The variation of resistance between different devices and even various cycles in the same device hold resistive access random memory back from commercialization. The emerging of atomic crystals, possessing fin interface without dangling bonds in low dimension, can provide atomic level solutions for the obsessional issues. Moreove the unique properties of atomic crystals also enable new type resistive switching memories, which provide a brand-new direction for the resistive access random memory.