基于Bitaper-LPFG-Bitaper结构的全光纤Mach-Zehnder干涉仪的温度传感特性

提出并制作出一种基于锥体光纤-长周期光纤光栅-锥体光纤结构的全光纤Mach-Zehnder(M-Z)干涉仪传感器,并对其温度传感特性进行了研究.实验结果表明,固定光纤锥体和长周期光纤光栅的结构,仅改变两个光纤锥体之间的距离,对应不同的M-Z干涉谐振峰呈现出不同的温度传感特性:随着两个光纤锥体之间的距离增加,位于短波长处的谐振峰,传感器的温度灵敏度减小,而位于长波长处的谐振峰,传感器的温度灵敏度增加.当传感器长度为16.5 cm时,在1 680 nm附近的温度灵敏度达到0.102 06 nm/℃.实验结果对于锥体光纤-长周期光纤光栅组合型温度传感器的优化设计具有重要参考价值.     

同时测定旱芹抗性淀粉和抗性低聚糖含量

建立了同时测定旱芹中抗性淀粉（Resistant Starch,RS）和抗性低聚糖（Resistant Oligosacch-arides,RO）含量的方法.通过模拟人体胃肠道的生理条件,除去样品中脂类物质、蛋白质和可溶性淀粉后,分别采用紫外分光光度法和酶-重量法测定RS和RO含量.RS含量在0.0160-0.1600mg/mL（r=0.9993）范围内呈良好的线性关系（n=6）,平均回收率为90.7％,RSD=2.0％ （n=9）;RO含量测定平均回收率为87.3％,RSD=2.9％ （n=9）.实验结果表明：该方法线性、精密度、重复性、稳定性和回收率试验均符合方法学验证要求.该方法操作简便,结果准确,重复性好,为全面测定旱芹膳食纤维（DF）中各组分的含量提供了依据,使旱芹DF含量标示更准确.     

紫外预电离放电引发的非链式脉冲DF激光器

采用紫外预电离的横向放电方式和稳定光学谐振腔,使用无毒无腐蚀性的六氟化硫(SF6)和氘气(D2)作为工作物质,研究了工作气体配比、总气压对放电引发非链式脉冲氟化氘(DF)激光器输出能量的影响。实验发现SF6与D2的最佳比例为10:1,最佳总气压为10.5 kPa。使用DF激光谱线分析仪对激光输出谱线进行了测量,得到了17条P支跃迁谱线,激光能量集中在3.876μm附近的几条谱线。利用烧蚀光斑的方法测得输出激光束水平方向、垂直方向的发散角均为1 mrad。在最佳工作条件下,充电电压为39 kV时,激光单脉冲输出能量达到最大值3.58 J,此时激光脉冲宽度为215 ns,峰值功率为16.65 MW,电光转换效率为2.08%。     

Ni掺杂ZnS的第一性原理计算

采用基于密度泛函理论(DFT)赝势平面波方法计算了ZnS体系Ni掺杂前后的能带结构、态密度和光吸收系数曲线。结果表明:纯ZnS的能带结构是直接带隙,态密度显示属离子性较强而共价键较弱的混合键半导体材料。掺Ni的ZnS禁带宽度随掺杂量增加逐渐减小,能带简并度增大,且向低能方向移动;在价带顶出现杂质能级,说明是p型掺杂。纯ZnS在3.9 eV以下无吸收,红外透过率较高。掺Ni后吸收边红移,且在低能端(绿光区)出现新的吸收峰。     

大学生在校成绩与高考成绩的统计分析

通过对合肥工业大学机械与汽车工程学院07级毕业生的高考成绩与本科期间在校成绩进行统计分析,研究发现高考成绩与在校的学期成绩有较大的相关性,且高考成绩对在校学期成绩的影响因专业的不同而不同.同时对部分代表性课程与高考成绩、已学课程成绩进行了统计建模,并就大学学习的特点及影响大学成绩的各个因素进行了讨论.     

关于伴随矩阵的Jordan形矩阵

给出从一个矩阵的Jordan形矩阵和最小多项式求解它的伴随矩阵的Jordan形矩阵和最小多项式的方法.     

Coherence preservation during light-surface plasmon polaritons-light transformation

We constructed a four-layer system composed of a prism,a silver film,an air layer and a lithium niobate crystal.Initially we used two coherent light beams to excite surface plasmons.The surface plasmons were then decoupled into light in the photorefractive crystal where a holographic grating was recorded.The two beams remained coherent through light to surface plasmons to light transformation.Studying the characteristics of the holographic grating we found out that the thickness of the grating was to the order of hundreds of microns.The thick holographic grating suggests that the holographic recording in the photorefractive materials was induced by the leaky waves rather than by surface plasmon polaritons directly.     

Experimental studies of linear phased-array transmitter acoustic logging in cased wells with scaled borehole models

Laboratory cased-hole acoustic logging simulations are developed with the linear phased-array transmitter in scaled cased well models for evaluating the feasibility of extracting formation acoustic parameters through casing.The full waveforms are measured with different cement bonding models.By analyzing the measured wavetrains and the time-slowness correlation graphs,it is showed that when the generation conditions of the refracted compressional wave and the refracted shear wave are reached successively by regulating the direction of acoustic beam radiated from the linear phased-array transmitter,steered angle of the main radiation lobe with both good bonding interfaces.The refracted compressional wave and the refracted shear wave can be stimulated obviously and the casing wave can be suppressed effectively,even when the casing and cement(or the cement and formation) is not bonded.Based on these observations, it is worthwhile to apply the linear phased-array transmitter to determine formation velocities,particularly in poorly bonded cased well.The works establish the experimental and theoretical foundation for new generation cased-hole acoustic logging tool development.     

New Lower Bounds for the Least Common Multiples of Arithmetic Progressions

Abstract For relatively prime positive integers u0 and r, and for 0 〈 k ≤ n, define uk ：= u0 ＋ kr. Let Ln ：= 1cm（u0,u1,... ,un） and let a,l≥2 be any integers. In this paper, the authors show that, for integers α≥ a, r ≥max（a,l - 1） and n ≥lατ, the following inequality holds Ln≥u0r^（l-1）α＋a-l（r＋1）^n.Particularly, letting l = 3 yields an improvement on the best previous lower bound on Ln obtained by Hong and Kominers in 2010.     

某厂房楼面在动荷载作用下的振动测试

根据现场实测结果,分析了受动荷载作用的钢筋混凝土多层框架结构厂房楼面产生较大竖向振幅的原因．结构加固后,为检测加固后的减振效果,对加固后结构再次进行了实地测试,通过对两次实测结果的对比分析,结果表明：经加固后楼面竖向振动幅度大大降低,达到其减振目的。