沥青水浆不同结构分散剂的成浆性能研究

对脱油沥青水浆中不同结构分散剂的成浆性能和分散剂用量进行了研究,并探讨了分散剂添加方法对沥青水浆的影响,提出了结构相似相容的沥青水浆的分散剂研制和选型方法以及分散剂最可几摩尔用量的概念。实验结果表明硬沥青水浆最佳分散剂应是自身改性的磺酸盐,符合沥青水浆HLB值要求。分散剂最可几用量的确定,有助于根据工业具体要求确定最佳用量,即流动性、稳定性都满足工业要求的分散剂最经济用量。所用分散剂溶于水,多段添加的湿式粉碎成浆可制取高浓度、低粘度、稳定性好的硬沥青水浆。     

基于区域分解的双调和方程的混合元近似解的分裂外推

本文主要讨论了基于区域分解的双调和方程的混合元近似解的分裂外推。并得到解的多变量展开。     

渣油及超临界戊烷精密分离馏分碳化的研究

采用超临界流体精密分离（ＳＣＦＥ）的方法将辽河减压渣油切割成多个窄馏分,在４３０℃、常压条件下对各馏分进行不同时间（２～１７ｈ）的热处理,测定了反应残余物的Ｈ／Ｃ元素比并在正交偏光下对反应残余物的光学显微结构进行观察。对渣油及其超临界戊烷精密分离馏分的热反应性能及反应残余物性质与原料性质的关系进行了讨论。研究结果表明：渣油组成的变化对其在碳化过程中的中间相形成、发展有十分重要的影响,采用ＳＣＦＥ可以将渣油切割为具有不同族组成的窄馏分,窄馏分的碳化试验表明,对组成适宜的窄馏分,在反应中可以形成各向异性发达的中间相,ＳＣＦＥ是一种改善重质烃类混合物碳化性能的有效技术。     

基于矢量线阵的目标低频线谱提取方法

主动声呐系统常采用线性调频信号探测水下目标。利用分数阶傅里叶变换处理线性调频回波时,可在低信噪比和强混响背景下获得目标参数的有效估计。主动声呐系统常通过增大发射信号的时间带宽积来提升系统的距离分辨力和速度分辨力,但却带来了计算复杂度的显著增加,尤其是奈奎斯特采样下基于分数阶傅里叶变换的回波处理方法,导致数据处理时间难以满足功耗和体积受限的无人水下航行器平台的实时性要求。针对此问题,该文提出分数阶傅里叶变换的带通采样实现方法,通过对线性调频信号时频特性直线在分数阶域的投影进行修正,使利用分数阶傅里叶变换方法处理带通采样的回波数据时,可获得正确的目标参数估计。计算机仿真数据和无人水下航行器湖试数据处理结果验证了分数阶傅里叶变换的带通采样实现方法的正确性,数据处理时间能够满足无人水下航行器平台处理的实时性要求。     

功能化石墨烯/活性炭复合电极及不对称电容器脱盐

以3-氨丙基三乙氧基硅烷(AMPTS)修饰氧化石墨(GO)还原合成氨基功能化石墨烯(GP-NH₂). 傅里叶变换红外(FTIR)光谱和X射线能谱(EDX)分析证明了氨基基团的成功接枝. 以GP-NH₂为添加剂, 制备胺化石墨烯/活性炭(GP-NH₂/AC)复合电极, 并以GP-NH₂/AC 为正极, AC电极为对电极, 组装不对称电容器(AC||GPNH₂/AC)用于电容脱盐. 实验表明, AC||GP-NH₂/AC 单循环脱盐量为7.63 mg·g^-1, 电流效率达77.6%. 利用磺酸重氮盐接枝石墨烯制备磺化石墨烯(GP-SO₃H)及磺化石墨烯/活性炭(GP-SO₃H/AC)复合电极. 并以GPSO₃H/AC为负极, GP-NH₂/AC 为正极, 组装不对称电容器(GP-SO₃H /AC||GP-NH₂/AC)用于电容脱盐, 其平均脱盐速率可达0.99 mg·g^-1·min^-1, 比纯AC电极提高了接近5倍. 充放电速率提高了30%; 而且由于正、负极表面固有电荷的存在, 大大降低了反离子效应, 电流效率由40% (纯AC||AC对称电容器)提高到92.8%. 表明电极内功能化导电石墨烯的存在既提高了导电性, 又兼具离子选择性的作用, 从而明显改善电极的脱盐性能.     

脱沥青油的催化裂化性质研究

在反应温度510 ℃，剂油比Cat/Oil=5（催化剂为5 g）,空速LHSV=15 h－1的实验条件下于重油微反装置中对几种脱沥青油的催化裂化性能进行了研究,并与掺兑减压渣油的VGO(减压馏分油)的裂化性能进行了对比。研究发现，减压渣油和掺兑催化油浆的减压渣油的丙烷脱沥青油具有较好的产物分布和选择性；而催化油浆的脱沥青油的裂化性能较差。     

高精度直流传感器DCCT标准测试系统

在北京正负电子对撞机二期改造工程(BEPCⅡ), 磁铁电源系统大量使用了电流型直流传感器(DCCT)作为电源的反馈和回采器件. 为了能够对DCCT的性能进行检测和校准, 设计研制了高精度直流传感器DCCT标准测试系统. 该测试系统主要由PC工控机、7.5数字万用表、超高精度直流传感器和高精度直流稳流电源构建而成. 论文中主要介绍了测试系统的功能和系统软、硬件结构, 并给出了测试系统在实际DCCT检测中的测量数据.     

Mechanism of micro-waviness induced KH₂PO₄ crystal laser damage and the corresponding vibration source

The low laser induced damage threshold of the KH2PO4 crystal seriously restricts the output power of inertial confinement fusion.The micro-waviness on the KH2PO4 surface processed by single point diamond turning has a significant influence on the damage threshold.In this paper,the influence of micro-waviness on the damage threshold of the KH2PO4 crystal and the chief sources introducing the micro-waviness are analysed based on the combination of the Fourier modal theory and the power spectrum density method.Research results indicate that among the sub-wavinesses with different characteristic spatial frequencies there exists the most dangerous frequency which greatly reduces the damage threshold,although it may not occupy the largest proportion in the original surface.The experimental damage threshold is basically consistent with the theoretical calculation.For the processing parameters used,the leading frequency of micro-waviness which causes the damage threshold to decrease is between 350-1 μm-1 and 30-1 μm-1,especially between 90-1 μm-1 and 200-1 μm-1.Based on the classification study of the time frequencies of microwaviness,we find that the axial vibration of the spindle is the chief source introducing the micro-waviness,nearly all the leading frequencies are related to the practical spindle frequency(about 6.68 Hz,400 r/min) and a special middle frequency(between 1.029 Hz and 1.143 Hz).     

Study on incident laser modulation using surface micro-defects on KH₂PO₄ crystal

KH2PO4 crystal is a crucial optical component of inertial confinement fusion.Modulation of an incident laser by surface micro-defects will induce the growth of surface damage,which largely restricts the enhancement of the laser induced damage threshold.The modulation of an incident laser by using different kinds of surface defects are simulated by employing the three-dimensional finite-difference time-domain method.The results indicate that after the modulation of surface defects,the light intensity distribution inside the crystal is badly distorted,with the light intensity enhanced symmetrically.The relations between modulation properties and defect geometries(e.g.,width,morphology,and depth of defects) are quite different for different defects.The modulation action is most obvious when the width of surface defects reaches 1.064 μm.For defects with smooth morphology,such as spherical pits,the degree of modulation is the smallest and the light intensity distribution seems relatively uniform.The degree of modulation increases rapidly with the increase of the depth of surface defects and becomes stable when the depth reaches a critical value.The critical depth is 1.064 μm for cuboid pits and radial cracks,while for ellipsoidal pits the value depends on both the width and the length of the defects.     

4-羟基-2-吡啶酮类化合物的合成研究进展

4-羟基-2-吡啶酮是天然生物碱结构母核,同时也是一类重要的医药中间体,该类衍生物具有抗真菌、抗菌和抗肿瘤等多种生物活性.因此,其合成得到了广泛的研究和关注.综述了近年来4-羟基-2-吡啶酮类化合物的合成方法及其研究进展.