频率可调的双路相位编码微波信号系统

提出一种在单输入情况下同时产生两路任意相位编码微波信号的方法,不仅可以保证编码信号180°的相移,还可实现编码信号的频率大范围调谐.建立由一个双平行马赫曾德调制器和一个保偏布拉格光栅组成的系统,激光输入双平行马赫曾德调制器调制后,通过保偏布拉格光栅与偏振分束器的共同作用产生两路偏振正交的±2阶边带.其中一对边带经过相位调制器调制后与另一对耦合,最后输出两个光电探测器拍频得到高频率、低噪声的相位编码微波信号.仿真结果表明,通过调节驱动信号的频率,可得到5～100 GHz的一系列四倍频相位编码微波信号.还原的相位信息与脉冲压缩比均和理论值吻合,证明了所提方法具有良好的脉冲压缩性能.     

基于DNA聚合酶I的新型电化学传感器及其胰腺癌K-ras基因点突变检测

本文构建DNA聚合酶I的新型DNA电化学传感器,将捕获探针通过Au-S键固定于Au基底表面,与互补靶序列杂交至点突变前一个碱基,通过DNA聚合酶Ⅰ将dUTP-biotin连接在目标DNA的检测位点,再与avidin-HRP反应,而后测定在TMB溶液中的电化学特性. 结果表明,DNA电化学传感电极的检测电流值与K-ras突变型基因浓度（1.0×10^-15 ~ 1.0×10^-10 mol·L^-1）对数呈良好的线性关系,且灵敏度高,特异性较佳.     

Self-compression of 1.8-μm pulses in gas-filled hollow-core fibers

We numerically study the self-compression of the optical pulses centered at 1.8-μm in a hollow-core fiber(HCF) filled with argon. It is found that the pulse can be self-compressed to 2 optical cycles when the input pulse energy is 0.2-m J and the gas pressure is 500-mbar(1 bar = 10~5 Pa). Inducing a proper positive chirp into the input pulse can lead to a shorter temporal duration after self-compression. These results will benefit the generation of energetic few-cycle mid-infrared pulses.     

激光相变烧蚀二维结构网格程序的数值计算

研究激光相变烧蚀二维结构网格程序,对液-气相变、固液汽三相物质进行整体模拟.激光相变烧蚀二维结构网格程序采用气化相变开始后在迎激光方向局部加密的重分方法,动量守恒方程采用Wilkins三角形回路积分法,能量守恒方程采用基于节点重构的扩散方程有限体积格式.     

高分子基础实验的优化与改革

为适应高分子材料与工程专业实验分层次教学改革的要求,结合我院高分子材料与工程专业的具体实际,在教学内容设计中融入科学、节约、环保的理念,对高分子基础实验体系、内容、组织与运行、教学方法与手段进行了整体优化和改革。使实验成本得到降低,污染物明显减少,实验教学效果得到显著提高,实现了高分子专业基础实验教学效益的最大化。     

TRANSESTERIFICATION IN POLYPHENYLSILSISQUIOXANE(PPSQ)/POLY ETHYLENE TEREPHTHALATE (PET) BLENDS

The chemical structure of copolymer formed in the transesterification of PPSQ/PET blendsduring melt-processing is deduced from the ~1H-NMR spectra. The transesterification extent ofthis blend is interpreted by the changes of crystalline melting peak in DSC thermograms of the in-soluble products containing unreacted PET and some block PPSQ segments. Effects of composi-tion of blend ladderlike regularity of PPSQ on the reaction extent have also been discussed.Inclusion of some block PPSQ segments in PET has no influence on the crystalline morphology ofPET.     

Theoretical and Experimental Studies on the Metal Complex of Diethylenetriamino-trioxo-molybdenum(VI) [MoO_3(NH_2C_2H_4NHC_2H_4NH_2)]

1 INTRODUCTION Molybdenum is a biologically important trace ele- ment that occurs in the redox-active sites of moly- bdoenzymes involving in nitrogen, sulfur or carbon metabolism. The structural chemistry of molybde- num complexes has aroused considerable interest in view of its higher oxidation states to form a number of compounds containing MoO groups, and informa- tion on these is very useful in understanding the behavior of MO groups generally[1~3]. Molybdenum oxide-based solids hav…     

低吸光度差示分光光度法测定油品中的铁

将一新的低吸光度差示分光光度法用于油品中铁的测定并与普通分光光度法测定结果的精密度和准确度进行了比较。结果表明，对于低吸光度样品的测定，该法较普通分光光度法准确。同时，该法克服了以前低吸光度差示分光光度法中差示吸光度与样品含量不成线性关系的不足。     

稻米代谢组学分析方法的建立及在产地溯源中的应用

采用气相色谱-串联四极杆飞行时间质谱(GC/Q-TOF MS)建立了稻米的代谢组学分析方法,并将其应用于产地溯源。利用D-最优设计对提取溶剂进行优化,通过偏最小二乘分析法考察了不同溶剂对代谢物提取效率的影响。考察了衍生试剂种类、衍生温度及时间对代谢物检测的影响,最终确定分析条件为:甲醇-水(1∶1)为提取溶剂,N-甲基-N-三甲基硅基三氟乙酰胺-三甲基氯硅烷(MSTFA-TMCS,99∶1)于60℃条件下衍生1 h。选取10种代谢物考察仪器精密度、方法重现性和衍生产物稳定性,相对标准偏差(RSD)均小于9%,证明了方法的可靠性。结合Mass Profiler Professional(MPP)软件,以主成分分析(PCA)法区分黑龙江省4个地区的29个绥粳4号稻米样本,分类效果显著。对显著变化(P0.05,倍率变化≥2)的差异性代谢物进行鉴定,确定了11种特征标记物。结果表明,利用GC/Q-TOF MS建立代谢组学分析方法,结合主成分分析鉴别稻米产地具有可行性,为大米市场的规范和资源开发利用提供了依据。     

Modeling of conducting bridge evolution in bipolar vanadium oxide-based resistive switching memory

We investigate the resistive switching characteristics of a Cu/VOx/W structure. The VOx film is deposited by radio- frequency magnetron sputtering on the Cu electrode as a dielectric layer. The prepared VOx sample structure shows reproducible bipolar resistive switching characteristics with ultra-low switching voltage and good cycling endurance. A modified physical model is proposed to elucidate the typical switching behavior of the vanadium oxide-based resistive switching memory with a sudden resistance transition, and the self-saturation of reset current as a function of compliance current is observed in the test, which is attributed to the conducting mechanism is discussed in detail. growth pattern of the conducting filaments. Additionally, the related