A Novel CMOSDual-Modulus Prescaler Based on New Optimized Structure and Dynamic Circuit Technique

s:A divide- by- 12 8/ 12 9or6 4/ 6 5 dual- modulus prescaler based on new optimized structure and dynam ic circuit technique im plem ented in 0 .2 5 μm CMOS digital technology is described.New optimized structure reduces the propagation delay and has higher operating speed.Based on this structure,an im proved D- flip- flop(DFF) using dynam ic circuit technique is proposed.A prototype is fabricated and the measured results show that this prescaler works well in gigahertz frequency range and consumes only35 m W(including three power- hungry output buffers) when the input frequency is2 .5 GHz and the power supply voltage is2 .5 V.Due to its excellent perform ance,the prescaler could be applied to many RF system s.

双回路控制下拖拉机发动机管理系统的设计

随着拖拉机发动机控制系统的复杂性在不断增加,拖拉机发动机扭矩管理系统需要满足多种工况需求,配备多种传感器和执行器,同时具备高效能和燃油经济性。为此,设计了基于双回路速度跟踪控制的拖拉机发动机扭矩管理系统,通过两个回路实现对发动机扭矩的精确控制,其中一个回路用于速度跟踪,另一个回路用于调节发动机扭矩。通过精确的速度控制和扭矩管理,系统可以在不同工况下实现高效的能量利用和优化的运行性能。试验结果表明:系统能够有效地实现发动机扭矩的准确控制,提高了拖拉机的整体性能和燃油经济性。研究结果旨在改进拖拉机发动机控制系统的性能,提高其适应多种工况的能力,并实现更高的燃油经济性。

CMOS Dual-Band Low Noise Amplifer

A CMOS dual-band low noise amplifer (LNA) design is presented.The purpose of th is work is intended to substitute only one LNA for two individual LNA's in dual -band transceivers for applications such as wireless local area network complying with both IEEE 802.11a and 802.11b/g.Dua l-band simultaneous input power and noise matching and load shaping are discuss ed.The chip is implemented in 0.25μm CMOS mixed and RF process.The measured pe rformance is summarized and discussed.

Generalized Yule-walker and two-stage identification algorithms for dual-rate systems

In this paper, two approaches are developed for directly identifying single-rate models of dual-rate stochastic systems in which the input updating frequency is an integer multiple of the output sampling frequency. The first is the generalized Yule-Walker algorithm and the second is a two-stage algorithm based on the correlation technique. The basic idea is to directly identify the parameters of underlying single-rate models instead of the lifted models of dual-rate systems from the dual-rate input-output data, assuming that the measurement data are stationary and ergodic. An example is given.

Experiments and Simulation of Thermal Behaviors of the Dual-drive Servo Feed System

The machine tool equipped with the dual-drive servo feed system could realize high feed speed as well as sharp precision. Currently, there is no report about the thermal behaviors of the dual-drive machine, and the current research of the thermal characteristics of machines mainly focuses on steady simulation. To explore the influence of thermal characterizations on the precision of a jib boring machine assembled dual-drive feed system, the thermal equilibrium tests and the research on thermal-mechanical transient behaviors are carried out. A laser interferometer, infrared thermography and a temperature-displacement acquisition system are applied to measure the temperature distribution and thermal deformation at different feed speeds. Subsequently, the finite element method （FEM） is used to analyze the transient thermal behaviors of the boring machine. The complex boundary conditions, such as heat sources and convective heat transfer coefficient, are calculated. Finally, transient variances in temperatures and deformations are compared with the measured values, and the errors between the measurement and the simulation of the temperature and the thermal error are 2 ~C and 2.5 pm, respectively. The researching results demonstrate that the FEM model can predict the thermal error and temperature distribution very well under specified operating condition. Moreover, the uneven temperature gradient is due to the asynchronous dual-drive structure that results in thermal deformation. Additionally, the positioning accuracy decreases as the measured point became further away from the motor, and the thermal error and equilibrium period both increase with feed speeds. The research proposes a systematical method to measure and simulate the boring machine transient thermal behaviors.

Determinants of Detection of Stones and Calcifications in the Hepatobiliary System on Virtual Nonenhanced Dual-energy CT

Objective To retrospectively determine the features of stones and calcifications in hepatobiliary system on virtual nonenhanced (VNE) dual-energy computed tomography (CT), and to evaluate the possibility of VNE images in diagnosis for those lesions. Methods A total of 128 gall stones and calcifications of the liver found in 110 patients were examined with triple phase abdominal CT scan from July 2007 to December 2011, in which true nonenhanced (TNE) phase and arterial phase were performed with single-energy CT (120 kVp) and portal venous phase was performed with dual-energy CT (100 kVp and 140 kVp). VNE images were generated from the portal venous phase dual-energy CT data sets by using commercially VNC software. The mean CT values for the stone, liver, bile and paraspinal muscle, mean lesion density and size in area dimension, contrast-to-noise ratio (CNR) of lesion to the liver or bile, and image noise were assessed and compared between VNE and TNE images. The effective dose and size-specific dose estimate (SSDE) were also calculated. Results The mean CT values of the lesions measured on VNE images declined significantly compared with those measured on TNE images (164.51±102.13vs. 290.72±197.80 HU,P<0.001), so did the lesion-to-liver CNR (10.80±11.82vs.18.81±17.06,P<0.001) and the lesion-to-bile CNR (17.24±14.41 vs. 21.32±17.31,P<0.001). There was no significant difference in size of lesions area between VNE and TNE images (0.69±0.88vs.0.72±0.85 cm2,P=0.062). Compared to the 128 lesions found in TNE images, VNE images showed the same density in 30 (23.4%) lesions, lighter density in 88 (68.8%) lesions, while failed to show 10 (7.8%) lesions, and showed the same size in 61 (47.7%) lesions and smaller size in 57 (44.5%)&nbsp;lesions. The CT cutoff values of lesion and size were 229.21 HU and 0.15 cm2, respectively. The total effective dose for triple phase scan protocol with TNE images was 19.51±7.03 mSv, and the SSDE was 39.84±11.10 mGy. The effective dose for dual phase scan protocol with VNE images instead of TNE images was 13.29±4.89 mSv, and the SSDE was 27.83±9.99 mGy. Compared with TNE images, the effective dose and SSDE of VNE images were down by 32.05%±3.69 % and 30.63%±2.34 %, respectively. Conclusions Although the CT values and CNR of the lesions decreased in VNE images, the lesions of which attenuation greater than 229.21 HU and size larger than 0.15 cm2could be detected with good reliability and obvious dose reduction. There was good consistency in the size of stones and calcifications in hepatobiliary system between VNE images and TNE images, which ensured the possibility of the clinical application of VNE images.

Rubbing-Induced Vibration Response Analysis of Dual-Rotor-Casing System

Considering gyroscopic effects caused by rotational speed,torsional vibration as well as coupling effects among inner rotor,out rotor and casing,a dynamic model of the dual-rotor-casing system is established using finite element(FE)method.By comparing the natural characteristics obtained from MATLAB and ANSYS,the developed model is verified.Then rubbing-induced vibration responses in dual-rotor-casing system are analyzed.The effects of rotational speed and speed ratio on rubbing vibration responses of the system are discussed.Results show that different combined frequency components will appear in the spectrum except two unbalanced excitation frequencies and their multiple frequency components,and these frequencies can be used as the dual-rotor aero-engine rubbing failure diagnosis frequencies when rubbing occurs.Besides,the amplitude of torsional vibration is larger than that of lateral vibration under the same working condition,and speed ratio has a great impact on the periodicity of the system rubbing-induced motion trajectory.The amplitude of rubbing-induced responses under counter-rotation is less than that under co-rotation with the same parameters.

Preparation of Hemodialyzer Made from Polyethersulfone Membrane by Dual-bath Coagulation Method

The dual-bath coagulation method was used for the preparation of PES membrane in this experiment. The main intent of this stndy was to assess the efforts of gelation conditions on the structures and properties. The dense top layer as well as porous supporting layer can be made by duel-bath coagulation method simultaneous- ly. Different internal quench medium obtained different membrane with different structures. With the increase in time in the first coagulation bath, pure water flux decreased and the clearance rates of urea and creatinine both first increased then decreased and increased slightly in the end. With the temperature of the second coagtdation bath increasing, pure water flux increases and the clearance rates of urea and creatinine first increases then de- creases and increases a little at last. Higher DMSO concentration （wt/wt） in the second coagulation bath results in the increase of pure water flux and the decrease of urea ＆ creatinine clearance rates.

DUAL-68000机终端功能数据库及应用

在DUAL-68000机上直接接上任意类型的终端,会出现系统不支持的情况。终端的很多功能,如光标移动、插行、删行、辅助接口等功能都不能应用。本文就这个问题提供解决办法。一、TERMCAP数据库简介 TERMCAP给出了终端所具有的功能集。说明了有多少终端操作指令将被执行,以此完成对终端的描述。在DUAL-68000机系统中,为了使用方便,定义了80多种终端功能,但一般常用的只有20来种,如表1。

Robust lag synchronization between two different chaotic systems via dual-stage impulsive control

In this paper, an improved impulsive lag synchronization scheme for different chaotic systems with parametric uncertainties is proposed. Based on the new definition of synchronization with error bound and a novel impulsive control scheme （the so-called dual-stage impulsive control）, some new and less conservative sufficient conditions are established to guarantee that the error dynamics can converge to a predetermined level, which is more reasonable and rigorous than the existing results. In particular, some simpler and more convenient conditions are derived by taking the same impulsive distances and control gains. Finally, some numerical simulations for the Lorenz system and the Chen system are given to demonstrate the effectiveness and feasibility of the proposed method.

“双元制”下职业教育学分银行的现实困境、发展方向与改进路径

职业教育学分银行建设是强化职业教育类型属性、推动技能型社会建设、打造国家资历框架的综合性项目,也是推动职普融通、产教融合、科教融汇的系统性工程。在职业教育与学术教育“双元制”育人范式下,职业教育学分银行还存在框架制度不完善、功能结构不健全、管理运行有滞碍、评估评价尚待改进等制约性因素,外部应用还存在机制、跨界、管理的时度效等制度性障碍。当前,必须明确学分银行未来建设发展的方向,致力打造成为教育与技术协同互动的桥梁纽带、职业教育高质量发展的统筹抓手、职业教育系统化改革的重要内容。因此,要以“双元制”范式为指引,建立学分银行的组织框架,健全学分银行的功能属性,创新学分银行管理模式,规范学分银行评价体系,真正推动职业教育学分银行赋能、提质、增效。

Analysis on Nonlinear Dynamic Properties of Dual-Rotor System

In order to clarify the effects of support structure on a dual-rotor machine,a dynamic model is established which takes into consideration the contact force of ball bearing and the cubic stiffness of elastic support. Bearing clearance,Hertz contact between the ball and race and the varying compliance effect are included in the model of ball bearing. The system response is obtained through numerical integration method,and the vibration due to the periodic change of bearing stiffness is investigated. The motions of periodic,quasiperiodic and even chaotic are found when bearing clearance is used as control parameter to simulate the response of rotor system. The results reveal two typical routes to chaos: quasi-periodic bifurcation and intermittent bifurcation. Large cubic stiffness of elastic support may cause jump and hysteresis phenomena in resonance curve when rotors run at the critical-speed region. The modeling results acquired by numerical simulation will contribute to understanding and controlling of the nonlinear behaviors of the dual-rotor system.

“双导师制”管理在麻醉专业学位研究生与住培并轨教育中的应用

目的:在麻醉学专业学位研究生与住培并轨教育中引入“双导师制”协同管理模式,探究该模式在提升教育质量与学生职业能力方面的有效性。方法:本研究选取中国医科大学附属盛京医院麻醉专业的60名硕士研究生为对象,通过随机数字表法分为对照组(n=30)与试验组(n=30)。对照组采用传统单导师教学模式,而试验组则实施创新的“双导师制”模式。试验组研究生除了接受学位导师的科研指导外,还配备经验丰富的住培导师,专注于临床实践能力的培养。本研究通过研究生自评问卷与专业考核成绩对教育效果进行评估。结果:相较于对照组,试验组在自评问卷和专业考核成绩上表现更佳(P<0.05)。结论:“双导师制”管理模式的引入显著提高了麻醉专业学位研究生的教育质量,有效增强了学生的专业能力和实践技能。

基于“双元制”的智能网联汽车专业课程体系模块化探索

为使智能网联汽车专业建设符合党的“二十大”对职业教育提出的“职普融合、产教融合、科教融汇”的发展要求,分析专业教育存在问题,提出以“双元制”为基础探索以模块化课程体系实现产教融合的路径;并在推进产业学院的视角下对构建智能网联汽车技术专业方向模块化课程体系进行了实践探索。

Neutronics Optimization of LiPb-He Dual-Cooled Fuel Breeding Blanket for the Fusion-Driven sub-critical System

The concept of the liquid Li17Pb83 and Helium gas dual-cooled Fuel Breeding Blanket (FBB) for the Fusion-Driven sub-critical System (FDS) is presented and analyzed. Taking self-sustaining tritium (TBR >1.05) and annual output of 100 kg or more fissile 239Pu (FBR > 0.238) as objective parameters, and based on the three-dimensional Monte Carlo neutron-photon transport code MCNP/4A, a neutronics-optimizated calculation of different cases was carried out and the concept is proved feasible. In addition, the total breeding ratio ( BR = TBR + FBR ) is listed corresponding to different cases.

Implementation and Evaluation of Dual-Purpose Normal and Disaster Situations System Based on Delay and Disruption Tolerant Bluetooth MANETs

Dual-purpose systems for both normal and disaster situations are necessary for providing continuous services from normal situations to disaster situations. We have been developing the dual-purposed systems based on the assurance network design principle. The assurance network design principle makes the dual-purpose systems work stably in both normal and disaster situations. This paper proposes a connectivity-dependent data propagation scheme, in which each terminal transfers data adaptively by wireless multi-hop data transfer or store-and-forward data transfer depending on whether the terminal has connections to its neighboring terminals. To verify the resilience against disconnection among neighboring terminals, we show field experimental results on data propagation time. Also we propose the dual-purpose system, in which there are two types of graphical user interface (GUI) for both situations. Whenever each terminal receives a special packet in disaster situations, the GUI automatically switches from one type for normal situations to another type for disaster situations. We have unified these two types of GUI so that users can understand how to use them even when GUI is automatically switched. To validate feasibility of the dual-purpose normal and disaster situations system, we show experimental results on dissemination of assessment information and automatical switching of GUIs.

Numerical Techniques Used in Modeling Codes for Dual-Reflector Antenna Design and Analysis

An user-oriented computer software consisting of three modeling codes, named DRAD, DRAA and FDPAT, is introduced. It can be used to design three types of Cassegrain system: classical, with shaped subreflector and with dual shaped reflectors, and to analyse radiation patterns for the antennas. Several mathematical models and numerical techniques are presented.

基于可信计算的保护控制设备主动防护技术研究与实现

变电站保护控制设备在边界安全防护体系下得以安全稳定运行,但随着信息化、网络化技术不断应用,变电站网络安全要求也在发生变化,过度依赖边界防护的保护控制设备缺乏本体主动防护能力的问题逐渐突显。文章比较分析了不同主动防护技术后,选择了基于可信计算的主动防护技术进行研究,结合保护控制设备的高实时、高可靠等特点,给出了适合保护控制设备的可信计算双体系架构和具体硬软件实现方案。最后,保护监控设备主动防护效果通过了第三方检测机构的验证,且防护功能的增加并未对设备的功能和性能产生明显的影响,该方案具备工程化应用和推广价值。

A Prototype Regional GSI-based EnKF-Variational Hybrid Data Assimilation System for the Rapid Refresh Forecasting System：Dual-Resolution Implementation and Testing Results

A dual-resolution（DR） version of a regional ensemble Kalman filter（EnKF）-3D ensemble variational（3DEnVar） coupled hybrid data assimilation system is implemented as a prototype for the operational Rapid Refresh forecasting system. The DR 3DEnVar system combines a high-resolution（HR） deterministic background forecast with lower-resolution（LR） EnKF ensemble perturbations used for flow-dependent background error covariance to produce a HR analysis. The computational cost is substantially reduced by running the ensemble forecasts and EnKF analyses at LR. The DR 3DEnVar system is tested with 3-h cycles over a 9-day period using a 40/13-km grid spacing combination. The HR forecasts from the DR hybrid analyses are compared with forecasts launched from HR Gridpoint Statistical Interpolation（GSI） 3D variational（3DVar）analyses, and single LR hybrid analyses interpolated to the HR grid. With the DR 3DEnVar system, a 90% weight for the ensemble covariance yields the lowest forecast errors and the DR hybrid system clearly outperforms the HR GSI 3DVar.Humidity and wind forecasts are also better than those launched from interpolated LR hybrid analyses, but the temperature forecasts are slightly worse. The humidity forecasts are improved most. For precipitation forecasts, the DR 3DEnVar always outperforms HR GSI 3DVar. It also outperforms the LR 3DEnVar, except for the initial forecast period and lower thresholds.

职业资格证书制度服务技能型社会建设:历史脉络、内在逻辑与实践理路

技能型社会建设是产业结构转型背景下提高社会整体技能质量水平的战略举措。社会的技能供给与需求两端的匹配关系决定着技能型社会建设的整体效果。职业资格证书制度在协调技能供需关系的过程中扮演着重要角色。梳理职业资格证书制度的发展历史,发现职业资格证书制度主要经历了技能供需高度匹配、偏向失配、走向适配三大阶段,分别对应的是工人技术等级考核制度、“双证书”制度、1+X证书制度三大形态。职业资格证书制度通过提升职教毕业生的就业质量、评价技能拥有者的技能水平、保障职教毕业生的职业生涯、为技能利益相关者带来好处等逻辑路径服务技能型社会建设。应从适当设计职业资格证书制度的建设思路、使职业资格证书制度与技能型社会建设融于一体两方面着手,深入推进职业资格证书制度对技能型社会建设的服务实践。