AlteraSRAM型现场可编程门阵列总剂量辐射效应

通过比较不同模块的输出波形、不同源程序的功耗电流以及输出端口的高、低电平随总剂量的变化关系,研究了AlteraSRAM型现场可编程门阵列（FPGA）器件在⁶⁰Coγ源辐照下的总剂量辐射效应。实验结果表明：器件的功能和功耗电流随总剂量的变化不同;不同模块随总剂量的变化关系相似,不同源程序的功耗电流随总剂量的变化趋势一致;总剂量辐照实验时功耗电流可作为判断器件失效的1个敏感参数。     

Poly(N-isopropylacrylamide) assisted microwave synthesis of magnesium aluminate spinel oxide for production of highly transparent films by hot compression

Magnesium aluminate spinel oxides have been prepared via poly(N-isopropylacrylamide) assisted microwave technique. The prepared MgAl₂O₄ powders showed a crystalline cubic structure with spinel phase after calcination at 600 °C only. The poly(N-isopropylacrylamide) amount showed a high effect on the crystallite size and the densification behavior of MgAl₂O₄. The increase of the amount of poly(N-isopropylacrylamide) reduced the sintering temperature of MgAl₂O₄ from 1400 °C to 1050 °C. The hot-pressed of MgAl₂O₄ powders in the presence of 3 wt% of poly(N-isopropylacrylamide) exhibited a full density at sintering temperature 1100 °C in 15 min only. The sintered films showed high transparency (81 ± 2%) in the wavelength range 500–1000 nm.     

塔里木盆地卡3区块二维地震采集技术研究

塔里木盆地卡3区块处于沙漠腹地，地表为复合型沙垄和沙山，深层地震地质条件较差，地震资料品质不高，波组连续性差，分辨率和信噪比低。为获取品质良好的地震资料，在该区进行了高密度二维地震资料采集技术研究，开展了表层结构调查、干扰波调查、激发和接收因素试验等工作，采取抽炮、抽道方式，得到了不同覆盖次数的剖面。用高密度采集技术获得的剖面，浅、中、深层反射波组齐全，奥陶系内幕反射资料信启、丰富，断层断点位置清楚，构造及低幅度隆起特征明显，反映了工区的地质结构特征。     

现场环境下设备区域电磁干扰检测与识别方法

现场环境下电磁环境复杂,设备区域电磁干扰的有效识别可为射电天文台站频谱分析提供重要依据.文章基于现场电磁干扰测量频谱,提出了一种电子设备区域干扰信号检测与识别方法.首先,针对对着设备区域和隔过设备区域两种测量状态多组频谱数据进行预处理,实现信噪分离,运用二值法检测信号边界,提取频谱中干扰信号.然后,依据一元回归算法和通道占用统计方法对多组测量频谱中干扰信号进行相关性分析,识别设备区域内电磁辐射频谱.所提方法对新疆天文台南山站内多个设备区域电磁辐射频谱检测结果与人工识别结果对比表明,本文方法94%以上的识别结果与人工识别结果相符,验证了现场环境下设备电子区域电磁干扰检测与识别方法的准确性和通用性.     

基于气相离子迁移谱的不同产地枣果挥发性有机物指纹图谱分析

采用顶空气相离子迁移谱（gas chromatography-ion mobility spectroscopy,GC-IMS）技术对新疆环塔里木盆地3个红枣主产区、河南新郑和山西临县31个不同产地枣果特征风味成分进行分析。通过构建枣果GC-IMS风味指纹图谱,对比明显,可以直观看出不同产地枣果挥发性有机物的差异。新疆各产地灰枣和骏枣与其原产地枣果挥发性风味物质差异明显。与骏枣相比,灰枣中对香气贡献最大的挥发性有机物主要有1-辛烯-3-醇（D）、2-甲基丙酸、3-辛酮（D）、丁酸、羟基丙酮等物质;而骏枣中对香气贡献最大的挥发性有机物主要有丙醛、2-丙酮、3-甲基丁醛、辛醛（M）、壬醛（M）等物质。     

基于分形理论的自动舵液压阀故障诊断方法研究

针对自动舵液压阀工作过程中存在的非线性问题,提出一种以阀芯位移信号分形特征为判据的故障诊断方法,并研究了分形特征参数——关联维数的计算方法和参数的选择。在建立液压阀数学模型的基础上,对液压阀正常和故障进行仿真,通过确定时间延迟、嵌入维数和无标度区,计算阀芯位移数据的关联维数。结果表明:不同状态的关联维数值具有明显的可分性,可以定量表征液压阀的工作状态,进而达到装备故障诊断的目的。     

基于三角基函数分解的高精度介损角测量方法

为精确测量介损角,克服数字化测量时存在的非同步采样、基波频率波动、谐波变化等因素影响,提出并建立基于三角基函数分解的介损角测量模型,将电力谐波各参数作为未知量,基于最小二乘原理对采样数据进行最速下降迭代求解,准确提取基波电压、电流相位,进而得出介损角,排除直流和谐波分量干扰。从理论上证明该算法的收敛性,针对基波频率波动、介损角真值改变、谐波含量变化、白噪声影响等影响进行仿真实验,结果表明该测量方法使用极少采样点与较低采样率,即可获得较高的测量准确度,测量速度快。设计的基于数据采集卡与虚拟仪器技术的高压电容型设备绝缘在线监测系统,验证了该方法的可行性与有效性。     

Synthesis of nanostructured gadolinium doped mixed ferrite: A novel catalyst for the mineralization of textile dyes

Herein, cobalt-nickel mixed ferrite (Co_0·5Ni_0·5Fe₂O₄, CNFO) and gadolinium doped cobalt-nickel mixed ferrite (Co_0·5Ni_0.5Gd_0.1Fe_1·9O₄, G-CNFO) materials have been synthesized at the nanoscale via the microemulsion technique. The physicochemical features of the CNFO and G-CNFO materials were examined by advanced structural (PXRD and FTIR), morphological (FESEM), elemental (EDX), and optical (UV/Vis and transient photocurrent) studies. Under visible light, the catalytic activity of CNFO and G-CNFO materials was compared using Congo red and Aniline blue dyes as model textile pollutants. The G-CNFO material showed better photocatalytic activity than CNFO material, as it eliminated almost 21% more dye than CNFO material under the same experimental conditions. In order to find the optimal parameter for the experiments, the variables affecting the catalytic properties of the G-CNFO material were investigated in considerable detail. These variables included pH, catalyst dosage, dye concentration, temperature, and irradiation time. Scavenging and transient photocurrent experiments were also carried out in order to determine the key reactive oxygen species and the formation of electron-hole pairs. The G-CNFO mineralized the Congo red dye almost three times faster than its counterpart and showed a negligible loss in its catalytic activity even after five successive catalytic cycles. The combined effects of the G-CNFO material's tuned band structure, high light harvesting abilities, reduced electron-hole recombination, and nanostructured morphology resulted in its enhanced photocatalytic activity.     

A review of cement-based materials as electroceramics

The dielectric behavior of unpoled cured cement-based materials enables these materials to serve as electroceramics. The behavior entails the DC polarization (apparent DC electrical resistivity increase), permittivity (AC polarization, capacitance measurement) and DC electret (permanent electric dipole, voltage measurement). The dielectric behavior is not derived from functional admixtures such as the perovskite ceramics. The polarization involves charge-carrier polarization, with the carriers being primarily the ions in the pore solution. Dipolar polarization associated with the polar water molecules plays a minor role. Silica fume, if present, decreases the permittivity, partly due to the pore refinement. A polymer admixture, if present, increases the permittivity, with significant polarization resulting from the cement-polymer interface. Carbon fiber, if present, affects the electronic and ionic conduction, with the fiber’s ozone treatment promoting the ionic conduction and enhancing the permittivity. As the water/cement ratio increases, the permittivity increases, but the DC polarization decreases. The DC polarization occurs faster and more significantly than the subsequent depolarization. This reflects the electret, which discharges upon short circuiting (as in capacitor discharge) and subsequently charges back upon open circuiting. The temperature increases the permittivity or the electret’s electric field, whereas tension decreases the same, enabling capacitance-based/voltage-based self-sensing of temperature and stress/strain.     

Core-shell structure strategy and oxygen vacancy engineering of 0.1LaMnO3@0.9(Ba0.5Sr0.5)TiO3 ceramics towards tuning electrical properties

In recent years, core-shell structures have attracted much attention for their potential in tuning the functional properties of materials and have become an effective method for preparing high-performance materials. In this work, core-shell structured 0.1LaMnO₃@0.9(Ba_0.5Sr_0.5)TiO₃ nanoparticles were fabricated by sol-gel method and dense ceramics were prepared at different sintering temperatures. The phase composition, morphology, chemical state and electrical properties were systematically investigated. Structural analysis confirmed the formation of 0.1LaMnO₃@0.9(Ba_0.5Sr_0.5)TiO₃ core-shell nanostructures. The results show that the prepared samples exhibit typical negative temperature coefficient characteristics in the range of 50–1000 °C, which is derived from the effect of carrier pairs and oxygen vacancies on the electrical properties. This study provides new insights from structure to material into guiding the development and design of advanced thermistor materials for temperature sensing applications.