异丁醛氧化制异丁酸的工艺研究

采用自制催化剂,对异丁醛液相氧化制异丁酸的工艺进行考察。结果表明,在反应温度20～50℃、氧醛摩尔比1．2：1、催化剂用量占异丁醛总质量的0．01％～0．05％、反应时间3～4h条件下,异丁醛转化率大于99．5％,异丁酸选择性在90％以上,分离精制后异丁酸产品纯度高于99．3％。     

时移地震中面元重置的方法及实现

在时移地震中，由于地震资料采集的时间不同，使用的观测系统、采集参数很难完全一样，为了对两次采集的三维数据进行分析比较,要将它们的面元校正到同样的位置和大小，即进行面元重置。首先对常用的相关抽道法做了介绍，并针对其不足提出了面元重置的一种新方法——动态求差插值法。这种方法能够适应面元重置时不规则道内插的需要，实现复杂地质情况下的面元重置。当地层倾角横向变化比较平缓时，可以使用相关抽道法，当地层倾角横向变化较大时，可使用动态求差插值法以获得好的处理效果。理论数据和实际资料的处理表明了方法的可行性和准确性。     

综合固井技术在胜利油田探井中的应用

随着胜利油田勘探开发的不断深入,原有的地层压力层系已破坏;另一方面由于勘探开发的需要,井越来越深。高压探井、长封固段探井及高难度探井不断增加,地下情况越来越复杂,影响探井固井质量的因素越来越多,但对探井固井质量的要求却日趋严格。针对胜利油田探井作业的实际情况,从井径扩大率、油气上窜速度、探井比例、封固段长度和扶正器数量等方面分析了影响探井固井质量的主要因素,兼顾固井工艺及水泥浆技术研究出一套适应胜利油田实际情况的固井工艺,并在实践中得到了应用。     

胡尖山油田三叠系延长组长21储层特征及控制因素

通过扫描电镜、铸体薄片、岩心和测井等相关资料分析,对鄂尔多斯盆地胡尖山油田三叠系延长组长2,砂岩储层特征进行研究。研究表明,储层砂岩主要为细一中粒长石砂岩和岩屑长石砂岩,分选较好,磨圆度以次棱状为主,填隙物以高岭石为主。储层物性较差,孔隙类型主要为粒间孔和长石溶孔,并发育少量的晶间孔及岩屑溶孔,属于低一中孔、低一特低渗...     

火炮身管内膛表层温度及其梯度规律研究

火炮射击过程中高温火药燃气可使身管内膛表面材料强度降低、发生相变甚至形成熔融态,加速身管内膛表面形成烧蚀、冲刷、磨损及开裂等损伤,研究身管内膛表面温度及梯度对揭示身管损伤机理具有重要意义。以大口径155 mm火炮身管对象,建立身管热-结构耦合动力学模型,仿真研究阳线棱边倒角、表面镀铬等对身管内膛表层温度的影响规律,结合实弹射击试验后身管内膛表面热影响层检测对仿真结果进行对比。研究结果表明：身管内膛表层温度沿径向快速衰减,形成极大的温度梯度,表面温度达到1 500 ℃、190 μm处温度超过727 ℃;阳线棱边存在明显的热累积,温度比阳线表面高出300 ℃以上,阳线棱边倒角后温度约降低100 ℃;内膛镀铬后可使基体温度降低约400 ℃。     

基于HHT的声频传感器车辆分类识别

针对传统语音信号识别过程中出现的识别率较低或者是计算时间复杂度高的问题,提出了基于希尔伯特黄变换(HHT)的快速声频传感器车辆识别方法.该方法将HHT算法和语音信号特征提取中常用的梅尔倒谱系数(MFCC)相结合,形成一种新的特征提取方法.实验中,将这种方法分别与K-近邻算法(K-NN)、支持向量机算法(SVM)和稀疏表示分类算法(SRC)配合进行语音信号识别,结果表明,该特征提取方法与K-NN分类算法配合,在识别率和算法运行效率方面具有明显的优势.     

Optical and electrical properties of porous silicon layer formed on the textured surface by electrochemical etching

Porous silicon (PS) layers were formed on textured crystalline silicon by electrochemical etching in HF-based electrolyte. Optical and electrical properties of the TMAH textured surfaces with PS formation are studied. Moreover, the influences of the initial structures and the anodizing time on the optical and electrical properties of the surfaces after PS formation are investigated. The results show that the TMAH textured surfaces with PS formation present a dramatic decrease of reflectance. The longer is the anodizing time, the lower is the reflectance. Moreover, an initial surface with bigger pyramids achieved lower reflectance in short wavelength range. A minimum reflectance of 3.86 % at 460 nm is achieved for a short anodizing time of 2 min. Furthermore, the reflectance spectrum of the sample, which was etched in 3 vol.% TMAH for 25 min and then anodized for 20 min, is extremely flat and lies between 3.67% and 6.15% in the wavelength range from 400 to 1040 nm. In addition, for a short anodizing time, a slight increase in the effective carrier lifetime is observed. Our results indicate that PS layers formed on a TMAH textured surface for a short anodization treatment can be used as both broadband antireflection coatings and passivation layers for the application in solar cells.     

Continuous Melt‐Drawing of Highly Aligned Flexible and Stretchable Semiconducting Microfibers for Organic Electronics

A scalable and green approach to manufacture semiconducting microfibers from polymer melts has been demonstrated. The polymer chains are highly aligned along the microfiber's long axis direction and exhibit highly anisotropic optical properties. In addition, the polymer microfibers show good flexibility and stretchability with a yield point around 10% under a reversible stress and can be stretched up to 180% without breaking. These features are desired for future flexible, stretchable, and conformable electronics. The origin of this stretchability is studied with diketopyrrolopyrrole derivatives using different conjugation break spacers and side chains. In addition, stretchable conducting microfibers can be obtained by doping with FeCl₃, which are further evaluated as organic conductors and source/drain electrodes in organic field‐effect transistors.     

单向收费对网络的影响分析

本文详尽地阐述了单向收费对移动网络关键要素的影响并进行了深入的分析,同时也分析了对财务和资本市场的影响,最后给出了建议的资费调整方案.     

EGPRS背景下的新型无线组网方案

随着国内大部分地区EGPRS功能的开启,移动用户的数据业务速率获得飞跃。本文首先分析了影~NEGPRS性能表现的无线资源瓶颈,接着引入了一种新型的无线组网方案作为改进,并通过南京地区的实际运用论述了该方案的可行性及可推广性。