地面驱动螺杆泵恒液面控制方法

恒液面控制有利于提高泵效,降低抽油杆柱和泵等设备的失效率。为此结合地面控制装置,研究了一种控制方法和软件。该软件根据控制装置实时测量的转速、扭矩等参数并结合地层开采能力、杆泵型号等参数,分析计算出液面高度和控制范围,并计算出转速改变量,由控制装置实行闭环控制。经大庆油田5口井试验表明,液面高度误差均在50 m内,实现了螺杆泵恒液面控制目的。     

热老化聚丙烯薄膜宏观力学性能及微观结构的研究

通过对热老化处理的聚内稀薄膜进行X射线衍射实验.对测得的实验数据采用X射线衍射线形分析理论处理,同时对热老化聚丙烯薄膜进行拉仲形变测量,得到材料的力学性质和微晶尺寸及内部点阵畸变的变化规律.从而将热老化聚丙烯材料宏观性质变化与微观结构联系起来,找出材料聚集态精细结构随老化时问而改变的微观规律.     

Effects of halothane anesthesia on the motility of the sphincter of Oddi and transsphincteric flow in Australian brush-tailed possums

We evaluated the effect of halothane anesthesia on the motility of the sphincter of Oddi and simultaneous transsphincteric flow in Australian Brush-tailed possums (Trichosurus vulpecula). Halothane levels in the range of 0.25 to 2% were administered and decreased transsphincteric flow in a dose-dependent manner. Sphincter of Oddi basal pressure was higher than normal, but not in a dose-dependent manner. Additionally, halothane anesthesia influenced the sphincter of Oddi motility by decreasing the motility index (mean amplitude multiplied by frequency of contractions). This decrease was dose dependent. These findings indicate that sphincter of Oddi basal pressure is a major component of sphincter of Oddi motility responsible for regulating transsphincteric flow in this species. For studies of the sphincter of Oddi motility in anesthetized Australian Brush-tailed possums, we recommend anesthetic induction with ketamine (50 mg/kg, i.m.) and the inspired halothane level should not exceed 0.75% during the study period, as the effects we have demonstrated were most evident at levels greater than 0.75%. If higher halothane levels are required to maintain satisfactory anesthesia, an alternative anesthetic agent should be considered.     

日本移动通信频率选择技术动向

本文介绍日本在移动通信中频率选择的技术动向以及开展移动通信频率资源的几项措施。     

由IR2155驱动的高功率因数电子镇流器

本文介绍了一种由ＩＲ２１５５驱动的电子镇流器功能特点和工作原理。     

数字分量电视图像的光纤传输实验

介绍了光纤传输数字电视的意义，电视信号分量数字化的标准和优点。利用自行研制的２７０Ｍｂ／ｓ光发射机和光接收机，建立了分量数字电视信号的光纤传输系统，直接传输了１００ｋｍ光纤，系统传输无误码，传输后图像质量不变。光接收机灵敏度达－２９．２４ｄＢｍ，动态范围为１３．５ｄＢ。无压缩电视图像的传输对于远程医疗和演播室间转输节目等有非常实际的意义。     

New multifunction filter using an inverting CCII and a voltagefollower

A new multifunction filter using minimum components is presented. This filter which possesses single input and four outputs can simultaneously generate second-order highpass, bandpass, and lowpass filtering functions at individual output terminals. The filter has the following merits; it uses only two grounded capacitors which makes it suitable for integrated circuit implementation, no matching condition is required, offering multifunction outputs and has low passive and active sensitivities. Experimental results agree very well with the theoretical result     

强度调制型光纤传感器信号补偿技术的现状与应用

简要地介绍了强度调制光纤传感器的特点,着重分析和比较目前国内外五种有代表性的强度调制型光纤传感器信号补偿方法及其应用状况.     

Na_2O－Al_2O_3－SiO_2系统霞石微晶玻璃机械强度的研究

霞石微晶玻璃是一种高强度的新型无机非金属材料．本文以Ｎａ２Ｏ－Ａｌ２Ｏ３－ＳｉＯ２系统为基础，引入晶核剂和复合澄清剂，经高温熔制和两步热处理制备的霞石微晶玻璃，具有较高的抗压和抗折强度．结果表明，霞石微晶玻璃的机械强度与霞石晶体及试样的结构有关，也与微晶化热处理的时间有关。     

用热分析法研究硝化棉的熔化过程

用ＭＤＳＣ，显微镜温台熔点测定仪和固体原位反应池／快速扫描傅立叶变换红外光谱联用装置考察了硝化棉的熔化过程。ＭＤＳＣ曲线表明吸热过程是可逆的，它系由ＮＣ和部分分解凝聚相产物的混合物的固液相变所引起。由ＮＣ的ＭＤＳＣ曲线得到的熔点，熔化含，熔化熵，分解含和分解反应热温熵分别为４７６．８４Ｋ，２０５．６Ｊ．ｇ＾－１，０．４３１２Ｊ．ｇ＾－１．Ｋ＾－１，－２４７５．０Ｊ．ｇ＾－１，－５．２４２Ｊ．ｇ＾－