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1.
措施项目在报价时,施工企业应根据招标文件要求和施工现场情况,并结合自身技术特点编制施工方案,确定措施费用。本文阐述了措施项目报价的定义及利弊。提出了在实际工程中措施项目清单报价的策略,最后探讨了清单计价形势下的措施项目报价的风险分析及应对措施。  相似文献   

2.
本文分别从混凝土原材料质量控制措施、混凝土的科学配制措施、工地试验室监督控制措施、提高混凝土和易性、混凝土的浇筑振捣措施、预防混凝土缺陷的发生措施、施工质量的保证措施等方面进行了混凝土施工质量控制措施和保证措施的论述。  相似文献   

3.
伴随着科技水准的持续提升,在先进的生产加工措施中高速切削措施在模具生产过程中得到了普及。本文主要介绍现代利用高速切削措施的现实情况,简单的讲述了高速切削措施的运用以及将来发展方向。  相似文献   

4.
朱斌 《中国科技博览》2011,(31):136-137
本文对窃电方式作了较为全面的分析,提出了目前反窃电工作遇到的问题。就如何开展反窃电工作,从技术措施和管理措施两个方面提出了措施。  相似文献   

5.
本文从近年"一带一路"战略背景下我国受国外技术性贸易措施影响的分析入手,系统总结了加强技术性贸易措施工作的重要性与必要性。对内蒙古技术性贸易措施工作现状进行研究,并梳理出当前内蒙古应对国外技术性贸易措施存在的问题,归纳提出了加强内蒙古技术性贸易措施工作的途径。  相似文献   

6.
在收集整理河南省水资源开发利用现状和节水农业发展等资料的基础上,综合考虑工程措施、农艺措施和管理措施等的影响,分析了河南省不同水平年可能达到的节水潜力,并就河南省实施半旱地农业的可行性进行了分析,提出了河南省不同分区发展半旱地农业的具体技术措施。  相似文献   

7.
随着经济全球化和贸易自由化进程的加快,技术性贸易措施形成的贸易壁垒已经取代传统的关税等壁垒成为国际贸易活动中最难以逾越的障碍,其中安全环保、节能减排、保源降耗是技术性贸易措施中的主要着力点,制冷产品则作为建筑用能大户属于技术性贸易措施的关注热点;中国作为制冷产品的出口大国,其制冷产品的出口与技术性贸易措施密切相关。我国制冷产品领域对技术性贸易措施的应对还属于起步阶段;因此本文对我国出口制冷产品技术性贸易措施及应对进行介绍。首先介绍了技术性贸易措施相关定义及其协定的主要内容,然后以通报评议实例对国外技术性贸易措施进行了说明和分析,最后给出了我国在制冷产品领域技术性贸易措施应对的建议。  相似文献   

8.
本文针对电气设计中的节能措施进行了分析与讨论。文章首先介绍了电气设计中采用节能措施目的与意义,然后在几个方面概述了电气设备节能的具体措施和方法,最后总结了采用措施带来的实际效益。  相似文献   

9.
针对矿井发现初起火灾的应急措施,火灾事故时的安全撤退和避灾待救措施,烟雾巷道里的避灾自救措施,不同火灾地点的避灾自救措施,进行了详细论述。  相似文献   

10.
杨明 《硅谷》2014,(22):133-133
根据大庆采油五厂第一油矿杏南二转油站情况,提出了提高火筒式加热炉热效率的方法和措施,并根据加热炉具体措施项目的数据,论述了节能措施的可行性和必要性,分析了火筒加热炉能耗高的原因。针对这些原因提出了降低能耗的多项措施,经现场实际运行表明:措施取得了良好的效果。  相似文献   

11.
A systematic approach for synthesising gyrator-C active transformers using MOS transistors is presented. The topology of gyrator-C active inductors and their characteristics are briefly reviewed first. This is followed by the development of ideal gyrator-C active transformers, where only the capacitor loads of the transconductors synthesising active transformers are considered. The self and mutual inductances of both the primary and secondary windings of active transformers are investigated in detailed. Non-ideal gyrator-C active transformers are developed with the consideration of both the resistance and capacitance loads of transconductors. The intrinsic relation between the self and mutual inductances is derived. The configuration of gyrator-C active transformers with multiple primary and secondary windings is also developed. The proposed active transformers offer large and tunable self and mutual inductances with virtually no silicon area requirement. Several practical implementations of the proposed active transformers have been realised in TSMC-0.18 mum 1.8 V CMOS technology and analysed using SpectreRF with BSIM3v3 device models. Simulation results on voltage transfer characteristics, self and mutual inductances, quality factors, stability, the effect of process variations, and noise are presented. The application of the proposed active transformers is exemplified using a 1.6 GHz active transformer quadrature oscillator.  相似文献   

12.
大型电力变压器振动和噪声控制方法研究   总被引:6,自引:2,他引:4  
本文在简要分析变压器振动和噪声产生的机理、传播途径和各种影响因素的基础上,论述了通过改变变压器油箱的动力特性来控制大型电力变压器振动和噪声的措施。  相似文献   

13.
A simple idea of using transformers as impedance adapters between TES and conventional JFET amplifiers, allowing to built an electronic readout system that does not degenerate the signal, will be presented. The theoretical modelling and systematic experimental results of such devices, indicate that there is a frequency range were the amplifier noise is negligible with respect to the TES noise.  相似文献   

14.
In connection with the Ebis ion source program at Saturne, diagnostics for low intensity and low energy ion beams have been developed. For intensities above 100 nA, beam profiles are provided by detectors made of printed alumina plates. Small current transformers located in the vacuum chamber allow the simultaneous observation of the total beam and of the time of flight spectrum. The residual noise of these transformers corresponds to 1 μA of beam.  相似文献   

15.
Summary The asymmetry coefficient for all types of transformers depends on the core permeability, which in turn depends on the ratio ofl av/s or Dav/s. In order to reduce core permeability, it is necessary to select toroidal cores with a small diameter and a large cross section, and provide laminas of O-shaped and shell-type cores with a shape to make these cores short and large in cross section.Under actual operating conditions, transformers with toroidal cores provide a higher immunity from noise. For the same designs, sizes, and relative parameter dispersions, the transformers with toroidal and O-shaped cores have a ratio of max equal to 1.6. In shell-type transformers it is imperative to take into account the polarity of their windings on which the transformer's noise stability depends to a great extent.  相似文献   

16.
In the power industry, current must be measured for metering and protection purposes. For such measurements, the use of magnetooptic current transformers offers many advantages. Conventional sensors, however, need two magnetooptic transformers to realize the required high dynamic range. Using a combination of analog and digital signal processing algorithms, the inherent low noise of the photonic input signals is maintained. The system design is based on a rigorous investigation and optimization of the error sources in the signal processing chain. The validity of this approach was confirmed by a demonstrator which achieved a dynamic range from 0.05 to 100 times the rated current and whose rms error was less than 0.5 %.  相似文献   

17.
We successfully used ferromagnetic core (Cryoperm 10) superconducting transformers to enhance the transfer of external magnetic flux to a symmetric two-holes rf biased quantum interference device (SQUID). The flux transfer ratio has been enhanced up to a factor of ten in comparison with air core superconducting transformers. It has been observed that the presence of ferromagnetic cores in the holes of the SQUID does not introduce additional noise, while it introduces a reduction in the Q of the 19 MHz tank circuit.The experimental results are discussed in the framework of a detailed analysis of the behaviour of the complete SQUID plus tank circuit plus ferromagnetic core superconducting transformer circuit.  相似文献   

18.
Reducing the size of power supplies raises the problem of new components that could be better candidates for integration. In this field, electromagnetic transformers may be replaced with significant benefit by piezoelectric transformers (PT). In a PT, the input electrical energy is transferred to the output by an acoustical means, using the direct and converse effects of piezoelectric materials. Its main advantages over an electromagnetic transformer are no magnetic noise generation, small size, high power density, and high efficiency. This paper deals with an innovative technique that produces a significant improvement of the power capability of piezoelectric transformers. This technique is based on a particular output voltage processing of the PT. Its effect is a vibration level reduction of the PT structure while keeping the output power practically constant. Vibration level is a critical parameter that determines the maximum power capability of a given PT. Thus, the new processing reduces significantly the losses of the PT. Both theoretical predictions and experimental results show that the increase of the power capability may reach 200%.  相似文献   

19.
变电站噪声会对周边环境产生影响,针对如何降低其影响,开发了“变电站环境噪声仿真分析及优化控制系统”软件,然后通过对噪声源、建筑物、敏感点、树木以及其它障碍物的整体仿真分析计算,优化新建变电站的规划设计方案和运行变电站的噪声治理方案。该方法能够提高噪声控制效果,降低工程造价,避免噪声控制设计过程中的随意性和盲目性,具有一定的推广应用价值。  相似文献   

20.
Ferroresonant, ballast, and current-limiting transformers are similar in geometxy. Optimization of weight, losses, or cost can result in different choices for the shape (core or shell) and proportions of the lamination. In the ferroresonant transformer, the problem of saturation losses, noise and stray flux can be alleviated by altering the geometry to produce a magnetic circuit with nonuniform flux density.  相似文献   

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