A 4.8–6.8 GHz low phase noise LC VCO in 0.13‐µm CMOS technology

This letter presents a novel LC voltage controlled oscillator (VCO) supporting the high‐speed serial transmission standard of RapidIO in 0.13‐µm complementary metal‐oxide semiconductor technology. The low phase noise is achieved through several techniques including current source switching, parallel coupled negative transconductance cell, and varactor bias combination scheme. Measured results of proposed circuit show a low phase noise of ?120 dBc/Hz at 1 MHz offset from 6.25 GHz carrier and tuning range of 4.8 ~ 6.8 GHz (34.48%) while consuming 7.4 mW under the supply voltage of 1.2 V. Copyright © 2015 John Wiley & Sons, Ltd.     

薄砂体储层定量预测技术应用研究——以WZ工区为例

单层厚度小于1/4个波长的薄层砂体,其厚度已经小于传统意义上的地震垂向分辨率。但是研究认为,在调谐效应下,薄层砂体厚度与地震反射振幅是存在线性相关关系的。利用这一特征,对WZ工区内两种不同类型的薄层砂体——大套泥岩夹单层砂体和砂泥岩薄互层砂体分别开展定量储层预测研究,通过体雕刻技术直接定量预测单砂体的厚度,通过层段的纵波阻抗平均值预测薄互层砂体总体厚度,最终获得薄层砂体的平面展布特征和厚度变化趋势。     

船用导航雷达收发系统的设计

介绍了一种船用导航雷达收发系统的设计,阐述了船用导航雷达的工作原理与系统构成,论述了收发系统的设计方法和工作原理,给出了调谐控制、灵敏度时间控制、射频控制单元的电路设计。     

Heat and mass transfer characteristics in a spray chamber

This paper presents a one-dimensional mathematical model for heat and mass transfer of water droplets in a spray chamber. The model includes drop size distribution and velocity of the droplets generated by a nozzle of inlet diameter 3.2 mm. By using the conservation of mass and energy, the changes in water temperature, air temperature and humidity along the spray cone in the spray chamber can be calculated. This model is tested with two different water mass flows. The results look reasonable from practical point of view and they also show that higher water mass flow results in a higher air temperature drop and higher humidity.     

Effect of throat diameters of the ejector on the performance of the refrigeration cycle using a two-phase ejector as an expansion device

This paper is a part in a series that reports on the experimental study of the performance of the two-phase ejector expansion refrigeration cycle. In the present study, three two-phase ejectors are used as an expansion device in the refrigeration cycle. The effects of throat diameter of the motive nozzle, on the coefficient of performance, primary mass flow rate of the refrigerant, secondary mass flow rate of the refrigerant, recirculation ratio, average evaporator pressure, compressor pressure ratio, discharge temperature and cooling capacity, which have never before appeared in open literature, are presented. The effects of the heat sink and heat source temperatures on the system performance are also discussed.     

在线净油装置主要参数的设定

对有载分接开关在线净油装置的参数进行了设置和分析,并给出了该装置的使用注意事项.     

Pull-out strength of axially loaded steel rods bonded in glulam parallel to the grain

Bonded-in steel rods are very efficient in withstanding high forces applied to timber members. Investigations of bonded-in rods started in the late eighties of the last century and several design models were published since. By comparing these approaches on base of an extensive literature review a certain degree of discrepancy and partly even contradiction can be found. The paper describes a test program which aimed to study the influence of timber density and of geometric parameters on the pull-out strength of single axially loaded steel rods. Following the GSA^®-procedure, which is a well established glued-in rods joint in Switzerland, rods with metric thread were bonded in glulam made of Norway spruce lamellas using an epoxy-type adhesive. The tests showed that the influence of the timber density can be quantified by a power function of ρ with an exponent of 0.6. The parameters length of the glued zone ? and diameter of the hole d _H can be summarized in the slenderness ratio λ = ?/d _H, which itself is related to the mean shear strength in the anchoring zone by an exponent of approximately ?1/3. In order to prevent the specimens from premature splitting, distances between the axis of the rod and the edge of the specimen of 2.3 times the diameter of the rod have been used.     

用Excel进行选矿数学建模

利用Excel建立曲线拟合模型的方法，可以灵活地解决矿物加工工程中遇到数学建模和应用的问题。文章以分配曲线为例，详细介绍多曲线中拟合模型的过程。     

潜孔钻机回转动力头参数计算与特性分析

目前，潜孔钻机普遍采用冲击回转凿入系统，用以产生回转力矩，对岩石产生剪切作用而成颗粒分离。本文分析了潜孔钻机回转装置的构成，两种动力机的拖动特性曲线，减速箱的基本要求，为潜孔钻机有关参数的设计和选用提供理论依据。