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1.
随着器件特征尺寸的减小,利用独立电流源进行单粒子瞬态(SingleEventTransient,SET)注入的方法与实际脉冲存在很大误差,器件/电路混合模拟能与实际较好符合,但在大规模组合逻辑的软错误率分析中使用器件/电路混合模拟非常耗时,急需电路级快速的SET注入方法。针对0.18μmCMOS反相器构建了基于二维查找表的SET耦合注入方法,并与器件/电路混合模拟的结果进行比较。结果发现:基于二维查找表的SET耦合注入方法与器件/电路混合模拟方法的结果比较符合,而仿真速度比器件/电路混合模拟快3个数量级。  相似文献   

2.
系统地阐述回旋加速器D电路的理论基础与实验方法,建议测定D电路各电容、及D电路与高频机配接的方法,并比较理论计算与实验数据。  相似文献   

3.
一种QAC实现方法与电路设计   总被引:2,自引:2,他引:0  
介绍了一种新的QAC的方法和电路,该电路主要由电流转换电路、恒流源电路、积分电路、模拟开关电路等组成,其突出特点是转换速度快、电路简单、输入信号范围大(≤600pC),适合构成多路QDC或多路QAC,在大型探测器阵列前端电子学系统中有着广泛的应用前景。  相似文献   

4.
Chua电路混沌系统的同步分析   总被引:1,自引:0,他引:1  
Chua电路是混沌系统中倍受人关注,具有广阔应用前景的混沌电路,如何同步混沌系统是应用的前提条件,用三种方法分析了Chua电路混沌系统的同步问题,为在电路上实现Chua电路混沌系统的同步提供了理论基础和技术指导。  相似文献   

5.
在发展髙性能多路小型化前端电路方面,阐述了一种用于测试时间的系统电路的设计与实现。其突出特点是转换速度快,电路结构简单,输入信号范围大、精度高、功耗低,电路采用改进的TAC方法,用于处理快速的时间信号,利用高速DMOS开关,并优化控制逻辑时序,极大提高了测试精度。  相似文献   

6.
该方法用于一种便携式辐射测量仪,仪器内部使用两个高低量程卤素计数管,测量过程中高低量程自动转换是其关键技术.常规方法采用阳极转换,需要高压继电器或其他高压开关器件,该方法采用阴极转换电路,电路由三极管、低压常闭干簧管继电器、阴极信号采集电路组成,该方法相比常规方法具有低压切换、切换可靠性高、低功耗的优点.  相似文献   

7.
文章对几种常见的核电子学滤波电路进行了数字模拟分析。利用拉普拉斯方法,得到了CR、R-C以及极零相消电路的输出函数,并通过Matlab模拟了负指数输入信号时的不同输出信号。在此基础上,模拟了低通S-K滤波成形电路的输出信号。结果表明,模拟得到输出信号与实际电路的输出信号具有相同的波形特性,该方法可以应用于核电子学滤波电路的分析。  相似文献   

8.
本文介绍了在没有高频电桥的情况下,测定D电路各参数及D电路的反射电阻的方法。  相似文献   

9.
为了提高核测量装置的保障性和维修性,本文以反应堆功率测量放大电路为对象,通过基于量子粒子群优化算法的多核相关向量机模型对电路的典型故障进行预测。从功率测量放大电路的脉冲响应信号中,用小波包分解方法提取特征信息,将计算所得到的特征与电路正常状态特征之间的欧氏距离作为电路故障程度指标,选用多核相关向量机建立电路故障预测模型,并分析了相关向量机模型核函数种类、参数优化算法对于模型预测效果的影响,研究结果表明采用量子粒子群算法优化的多核相关向量机模型对于电路未来运行状态的预测精度较优,能够准确预测电路故障程度的变化规律。   相似文献   

10.
计数率表中“贮能”阻容电路的统计特性   总被引:1,自引:0,他引:1  
本文计算了具有双时间常数的计数率表电路,在不同使用情况下的统计涨落偏差及读数建立时间和由于统计涨落而触发讯号电路发生假讯号的可能性。计算结果表明,这种电路在以上各项性能上均略优于单时间常数的电路。文中给出了设计这种电路所需的公式和图表,并提出与分析了在一定条件下缩短读数建立时间的一种使用方法。  相似文献   

11.
The pH-sensitive polyacrylic acid (PAA) hydrogels were synthesized by gamma-ray irradiation at an ambient temperature. The influences of dose, monomer concentration, cross-linking agent content, pH, and ionic strength on the swelling ratio (SR) of the PAA hydrogels were investigated in detail. The results show that the SR of the hydrogel decreases with an increase in the dose, monomer concentration, and cross-linking agent content. In alkaline solution, the SR of the hydrogels is much higher than that in acid solution. Also, the ionic strength can influence the SR of the hydrogels. The more the concentration, the lower the SR.  相似文献   

12.
铀的高效富集和分离对于核能可持续发展具有重要意义。吸附法作为一类重要的分离方法,吸附材料在其中扮演着关键角色。本文综述了近年来基于仿生多巴胺化学制备铀吸附材料的研究进展。第一部分首先介绍多巴胺化学的基本原理,着重讨论多巴胺的自聚合机理、聚集体结构及其聚合过程的控制因素;第二部分列举利用多巴胺化学表面改性制备不同类型的复合吸附材料,包括碳基纳米材料、多孔硅基材料、无机黏土矿物、金属或共价有机框架化合物、纳米高分子纤维等,探讨针对不同材料体系的多巴胺改性方法,以及对吸附材料组成、结构的影响;第三部分集中介绍多巴胺改性材料对铀的吸附性能研究,按照材料功能基团的差异,分为本征多巴胺涂层、多巴胺-无机复合涂层、多巴胺-高分子复合涂层三个方面,阐述各类材料对铀的吸附行为和机理。本文最后总结了多巴胺化学在吸附材料制备方面尚存在的挑战,并展望了本领域的发展前景。  相似文献   

13.
核安保以防范核材料非法窃取使用和核恐怖袭击为主要任务,是国家安全的重要组成部分。近年来,随着技术的发展进步、制造成本的持续下降、应用模式的不断增加,无人机的消费迅速走强。这导致无人机可获得性不断提高,无人机侵入敏感设施的事件时有发生。无人机对核设施等关键基础设施安全的影响,给核材料、核设施的安保带来了挑战,引发了业界的...  相似文献   

14.
Nuclear analyses provide essential input to the conceptual design, optimisation, engineering and safety case of fusion technology in current experiments, ITER, next-step devices and power plant studies. Calculations are intricate and computer-intensive, typically requiring detailed geometry models, sophisticated acceleration algorithms, high-performance parallel computations, and coupling of large and complex transport and activation codes and databases. This paper reports progress on some key areas in the development of tools and methods to meet the specific needs of fusion nuclear analyses. In particular, advances in the production and modernisation of reference models, in the preparation and quality assurance of acceleration algorithms and coupling schemes, and in the evaluation and adaptation of alternative transport codes are presented. Emphasis is given to ITER-relevant activities, which are the main driver of advances in the field. Discussion is made of the importance of efforts in these and other areas, considering some of the more pressing needs and requirements. In some cases, they call for a more efficient and coordinated use of the scarce resources available.  相似文献   

15.
The abnormal accumulation of Pu(IV) in the first co-decontamination process has been studied under a hypothetical flowsheet using computer simulation programs, i.e., MIXSET-X, EXTRA-M, ESSCAR, and SAFE, to understand the program characteristics and the effects of the major independent parameters incorporated in the codes. The characteristic quantitieson the Pu(IV) accumulation, e.g., the peak concentrations of Pu(IV) in the first HA extractor and the corresponding values of the independent variables, have been demonstrated to be good indicators for comparing quantitatively among the numerical predictions made using different codes. The effects of the basic models adopted for the numerical codes and the effects of the equilibrium distribution ratio have been demonstrated and discussed. Moreover, the strong effects of the flowsheet parameters, i.e., the flow rates and the solute concentrations of the external feeds, as well as the extractor length have also been examined.  相似文献   

16.
This paper summarizes the presentations and discussion at the Energy Options for the Future meeting held at the Naval Research Laboratory in March of 2004. The presentations covered the present status and future potential for coal, oil, natural gas, nuclear, wind, solar, geothermal, and biomass energy sources and the effect of measures for energy conservation. The longevity of current major energy sources, means for resolving or mitigating environmental issues, and the role to be played by yet to be deployed sources, like fusion, were major topics of presentation and discussion.Summary of the Meeting held at the U.S. Naval Research Laboratory, March 11–12, 2004  相似文献   

17.
《Fusion Engineering and Design》2014,89(9-10):2246-2250
EDFA, as part of the Power Plant Physics and Technology programme, has been working on the pre-conceptual design of a Demonstration Power Plant (DEMO). As part of this programme, a review of the remote maintenance strategy considered maintenance solutions compatible with expected environmental conditions, whilst showing potential for meeting the plant availability targets. A key finding was that, for practical purposes, the expected radiation levels prohibit the use of complex remote handling operations to replace the first wall. In 2012/2013, these remote maintenance activities were further extended, providing an insight into the requirements, constraints and challenges. In particular, the assessment of blanket and divertor maintenance, in light of the expected radiation conditions and availability, has elaborated the need for a very different approach from that of ITER. This activity has produced some very informative virtual reality simulations of the blanket segments and pipe removal that are exceptionally valuable in communicating the complexity and scale of the required operations. Through these simulations, estimates of the maintenance task durations have been possible demonstrating that a full replacement of the blankets within 6 months could be achieved. The design of the first wall, including the need to use sacrificial limiters must still be investigated. In support of the maintenance operations, a first indication of the requirements of an Active Maintenance Facility (AMF) has been elaborated.  相似文献   

18.
Adsorption of iodine on graphite is of great interest for operation and safety of high temperature nuclear reactors. Graphite can adsorb significant amounts of iodine and retain it for a long period of time. Significant amount of work on this subject has been done in the past. Various types of adsorption apparatus have been designed and data were collected. The types of graphite used in past studies are not available anymore, and as a consequence the data are not applicable for the new type of commercial nuclear grade graphites. However, the past experimental systems, data, and their analysis are useful to design a better experimental system, collect more accurate data, and, provide better understanding of the adsorption process and data. In addition the existing data can be used to generate a framework to understand the types of adsorption processes taking place. In this work, we have conducted an exhaustive literature review and further analyzed the data. Four adsorption isotherms; the Langmuir, the Freundlich, and the two isotherms proposed in the International Atomic Energy Agency (IAEA) Tecdoc-978 were used to correlate the available equilibrium adsorption data. For most of the data, the simple Langmuir and the Freundlich isotherms provided a reasonable fit of the data. The Polyani's potential theory was also used to check the consistency of the data and as indicated by the theory, most of the data set provided a single characteristic curve. The isosteric heats of adsorption calculated using the literature data suggested that iodine-adsorption on graphite could be a chemisorption process.  相似文献   

19.
在热释光剂量测量中,参考光源强度是影响测量结果的重要因素之一。对参考光源强度的调整往往通过调整测量仪器的高压来实现,但调高高压参数会导致测量仪器暗电流增加,进而导致测量值偏差增大。频繁的调整高压参数,也可能会使仪器的稳定性变差。针对参考光源强度变化导致的测量偏差,提出利用测量时的参考光源强度值与校准测量时参考光源强度值的变化求出相应的修正系数,进行测量结果修正。该方法经标准值样片测量检验,其测量值更准确、误差更小,与标准辐照值的偏差小于5%,表明该方法可行,可在实际工作中应用。  相似文献   

20.
人发中微量元素与某些呼吸系统疾病关系的研究   总被引:1,自引:0,他引:1  
侯小琳  吴兰兰 《核技术》1995,18(2):121-128
用仪器中子活化法测定了正常人和慢性支气管炎,肺气肿,肺心病患者头发中Ca,Mg,Fe,Se,Cu,Zn等19种元素的含量。测得患者发中Ca,Mg含量低于正常人,Fe,As,Co等含量高于正常人;慢性支气管炎急发期患者发中Ca,Mg含量低于缓解期患者,Fe含量高于缓解期患者,均有显著性差异(P<0.05-0.01)。人发Ca与Mg呈高度正相关(P<0.001)。还测定了用于治疗慢性支气管炎的中药“咳  相似文献   

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