PDM 1kW全固态中波广播发射机的安装与维护

由于科学的不断发展,技术不断进步,全固态PDM发射机,采用了新型的固态放大器件,因而取代了能耗高、效率低的大功率电子管。本文论述PDM 1kW全固态中波广播发射机的安装与维护。     

全固态电视发射机的维护

现阶段全固态发射机已普及，本文从全固态发射机与电子管发射机维护区别及全固态发射机自身特点入手，改善机器运行的内外部环境，结合本台实际提出使用与维护中应该注意的几个问题。     

浅谈全固态中波发射机的检修与维护

全固态中波广播发射机已经替代了电子管发射机。本为简要介绍了全固态中波广播发射机的检修和维护方法,提出了一些常见故障的检修部位,对从事广播电视的技术人员具有参考价值和借鉴意义。     

西新工程与7361工程

全固态中波广播发射机开始进入中波台技术人员的视野。由于固态机的高效率高质量的魅力强烈地震撼着我们,使我们深深地感到,固态机取代电子管机是中波广播发射机的发展方向。本文对西新工程与7361工程进行了论述.     

浅谈全固态电视发射机的常见故障检修与维护

随着电子技术的飞速发展,全固态电视发射机已经完全取化电子管的发射机,并向智能化、数字化方向发展.文中对全固态电视发射机的基本原理,在实际运行中出现故障时的分析判断和处理、日常维护的科学方法.     

全固态DM中波发射机的防雷保护

全固态PDM中波广播发射机由于全部采用了晶体管器件,整机效率比传统的电子管乙类屏调发射机提高了25%～30%,但由于晶体管器件对瞬态过电流、过电压的承受能力不及电子管,因此,全固态PDM中波广播发射机的抗雷击性能比较弱,对全固态PDM中波广播发射机天线及天调网络应采用多重防雷保护措施。     

浅谈电视发射机的维护

近年来,新型全固态电视发射机正逐步淘汰以前的电子管发射机,成为各地广播电视部门电视信号发送的主力军.如何维护好尚有较大利用价值的速调管发射机,尽量延长其使用寿命,是一个十分重要的技术课题.     

固态中波发射机的使用与维护

本文介绍了中波广播的概念以及全固态发射机的基本原理,在此基础上,简要阐述了全固态发射机的发展历程及其主要优点。结合工作经验,提出一些固态中波发射机使用中需要注意的问题以及维护经验,为相关专业的专业人士提供学术和技术上的借鉴。最后对中波广播发射提出一些展望。     

发射机电子管维护体会点滴

我台电视发射台共有六部发射机，除第二频道是全固态发射机外，其余五部使用的是大功率电子管做为末级放大的主要部件的发射机，由于电子管的价格昂贵（特别是分米波电子管），因而造成维护费用的增加。所以，研究影响电子管使用寿命的各种因素，是我们在工作中的重要任务之一，下面就工作实践谈谈发射机电子管的维护体会，提高电子管的使用效率。一、电子管寿命的终结通常是指以下几种情况：1、阴级衰老、放射电子能力下降，由此会使发射机输出功率下降，至使各项指标达不到规定的要求，必然影响电视节目的播出质量，这种情况通常我们称它…     

全固态中波发射机的常规维修探讨

全固态中波发射机较比电子管发射机有着明显优势,其不仅可以节省维修费用,而且维修量少、安全可靠,但是使用该种发射机时也有其一定的特殊性,也有其严格的规范和管理制度。本文主要介绍了全固态中波发射机的维修内容,注意事项以及如何处理维修过程中的问题等。     

压电陶瓷变压器及其应用现状

对压电陶瓷变压器的理论研究及应用现状作了较为全面的探讨和评述,并分析了存在的问题和今后发展方向.压电陶瓷变压器是一种新型固态电子器件,它具有结构及工艺制作简单、体积小、重量轻、无电磁噪声、无电磁式绕组、不可燃烧、完整性好以及大规模生产成本可以大幅度降低等优点.目前压电陶瓷变压器已在液晶显示器中的冷阴极管、霓虹灯管、激光管和X光管、高压静电喷涂、高压静电植绒和雷达显示管等方面得到广泛应用.     

彩色显像管的地磁屏蔽(Ⅰ)

为提高彩色显像管质量,减小地磁场影响,针对目前彩色显像管生产中需借助高斯房模拟销售区域地磁场对彩色显像管预调的局限性,研究了1种经济有效的屏蔽地磁场影响的新装置.采用先进的彩色显像管性能测试仪,在相同条件下与现行屏蔽方式就屏蔽效果进行了测试与对比,结果表明该装置可抑制地磁场对彩色显像管的干扰,提高彩色显像管地磁场裕度;可省略彩色显像管生产中模拟和调整地磁场的工序,具有降低生产成本、增进效益的实用价值.     

Spintronic materials and devices based on antiferromagnetic metals

In this paper, we review our recent experimental developments on antiferromagnet (AFM) spintronics mainly comprising Mn-based noncollinear AFM metals. IrMn-based tunnel junctions and Hall devices have been investigated to explore the manipulation of AFM moments by magnetic fields, ferromagnetic materials and electric fields. Room-temperature tunneling anisotropic magnetoresistance based on IrMn as well as FeMn has been successfully achieved, and electrical control of the AFM exchange spring is realized by adopting ionic liquid. In addition, promising spin-orbit effects in AFM as well as spin transfer via AFM spin waves reported by different groups have also been reviewed, indicating that the AFM can serve as an efficient spin current source. To explore the crucial role of AFM acting as efficient generators, transmitters, and detectors of spin currents is an emerging topic in the field of magnetism today. AFM metals are now ready to join the rapidly developing fields of basic and applied spintronics, enriching this area of solid-state physics and microelectronics.     

First visualization of glutamate and GABA in neurones by immunocytochemistry

Immunocytochemical methods for peptides and serotonin have greatly advanced the study of neurones in which these substances are likely to be transmitters. Such direct techniques have not so far been available for the amino acid transmitter candidates. We report here the selective immunocytochemical visualization of the putative transmitters glutamate (Glu) and gamma-aminobutyrate (GABA) by the use of antibodies raised against the amino acids coupled to bovine serum albumin (BSA) with glutaraldehyde (GA). The tissue localizations of Glu-like and GABA-like immunoreactivities (Glu-LI and GABA-LI) matched those of specific uptake sites for Glu and GABA, and, in the case of GABA-LI, also that of the specific marker enzyme glutamic acid decarboxylase (GAD). Thus, GABA-LI was located in what are believed to be GABAergic inhibitory neurones, whereas Glu-LI was concentrated in excitatory, possibly glutamatergic neurones. Preliminary electron microscopic observations suggest that the transmitter amino acids are significantly concentrated in synaptic vesicles.     

Decoherence-protected quantum gates for a hybrid solid-state spin register

Protecting the dynamics of coupled quantum systems from decoherence by the environment is a key challenge for solid-state quantum information processing. An idle quantum bit (qubit) can be efficiently insulated from the outside world by dynamical decoupling, as has recently been demonstrated for individual solid-state qubits. However, protecting qubit coherence during a multi-qubit gate is a non-trivial problem: in general, the decoupling disrupts the interqubit dynamics and hence conflicts with gate operation. This problem is particularly salient for hybrid systems, in which different types of qubit evolve and decohere at very different rates. Here we present the integration of dynamical decoupling into quantum gates for a standard hybrid system, the electron-nuclear spin register. Our design harnesses the internal resonance in the coupled-spin system to resolve the conflict between gate operation and decoupling. We experimentally demonstrate these gates using a two-qubit register in diamond operating at room temperature. Quantum tomography reveals that the qubits involved in the gate operation are protected as accurately as idle qubits. We also perform Grover's quantum search algorithm, and achieve fidelities of more than 90% even though the algorithm run-time exceeds the electron spin dephasing time by two orders of magnitude. Our results directly allow decoherence-protected interface gates between different types of solid-state qubit. Ultimately, quantum gates with integrated decoupling may reach the accuracy threshold for fault-tolerant quantum information processing with solid-state devices.     

快电子扫描高清晰度硅靶摄象管的理论研究

文中提出一种新型的高清晰度电视摄象管的方案。特点是采用“反向击穿硅光电二极管”做靶面,并用快电子扫描。它不仅具有快电子扫描分辨率高的优点,还具有慢电子扫描的优点,因而是高清晰度电视摄象管的较理想的工作模式。文中讨论了该方案的有关理论问题。     

CuO纳米晶的一步超声室温固相合成及表征

在室温条件和超声波作用下,通过固相化学反应一步合成了CuO纳米晶,用粉末X射线衍射（XRD）及电子衍射法（ED）分析了固相产物的物相,用透射电镜（TEM）观测粒子的大小、形貌、粒径及粒径分布．结果表明,产物为颗粒大小均匀、晶粒形貌为近似球形粒状,平均粒径约为20nm的纳米晶,产率为93．1％．改变反应物、反应物配比、掺入惰性物质、加入微量溶剂或表面活性剂、研磨不同的时间等固相反应条件对合成CuO纳米晶的晶粒形貌、粒度和粒径分布有一定影响．     

密封式中子管中电子电流形成过程

分析中子管中电子电流的形成过程．对于Philip型中子管,D 离子轰击靶产生的二次电子直射进入加速区,形成的电子电流仅是总电子电流的一部分．为完整地解释电子电流的形成,必须考虑到二次电子在加速电极内壁上的散射和新产生的二次电子进入加速区形成电子流的因素．     

低温固相法制备Cu2O纳米晶

本论文基于绿色化学的思想，运用低温固相反应实验技术成功地实现了氧化亚铜纳米晶的制备。用X—射线粉末衍射(XRD)和透射电镜(TEM)对所得产物进行了表征，并对氧化亚铜棒状结构的形成机理做了初步探讨。     

Morphology and microstructure characterization of 95W-3.5Ni-1.5Fe powder prepared by mechanical alloying

Morphology and microstructure characterization of 95W-3.5Ni-1.5Fe powder prepared by mechanical alloying@Islam S.Humail$State Key Laboratory for Advanced Metals and Materials,Materials Science and Engineering School, University of Science and Technology B…