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中子活化分析法作为标准物质元素定值权威方法的研究 总被引:5,自引:1,他引:4
中子活化分析全面参量化方法与传统的相对比较法相结合,初步满足了国际标准化组织对标准物质元素定值权威方法的定义。首次担子同中子活化分析法可作为RM一批元素定值的权威方法。对典型的地质、岩石圈环境有证标准物质CRM的分析结果表明:Al,As,Ce,Co,Cr,Cs,Eu,Fe,Hf,La,Lu,Mn,Na,rB,sB,sC,Ta,Tb,Th,Yb等20种元素的的实验测定值与推荐值与误差范围符合得很好, 相似文献
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用计算机模式识别法和PIXE法研究人发中元素在食管癌诊断中的作用 总被引:3,自引:0,他引:3
用PIXE方法对华北地区的414例食管癌、食管上皮重度增生病人和正常人的头发样品中的12种元素进行了测定。经过t检验发现,癌症病人与正常人比较,10种元素(Si,S,Ca,Cr,Mn,Fe,Ni,Cu,Pb,Sr)有显著差异;食管上皮重度增生病人和正常人比较,9种元素(Si,P,S,Ca,Cr,Mn,Fe,Ni,Zn)有显著差异,说明头发中微量元素的变化先于人体内食管的癌变。用计算机模式识别法对上 相似文献
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《核标准计量与质量》2005,(1):8-10
认真领会胡锦涛总书记对军工质量工作的重要批示:“要采取坚决措施,果断处置,不留隐患,同时,要举一反三,严格质量管理,确保产品质量。”认真贯彻执行国防科工委2004年质量工作会议的有关精神,结合集团公司2005年的工作重点,加强工作力度,抓质量管理体系建设,抓质量监督,抓可靠性工作,加强对重点工程和军品、核产品的监控,提高各级人员的质量意识,确保核工程建设质量和产品实物质量稳定提高。 相似文献
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《核标准计量与质量》1998,(1)
国营二六二厂是中国核工业总公司所属大型仪器仪表企业。工厂对提高产品质量,搞好质量管理工作的重要意义觉悟较早。企业对建立健全质量体系,提高全员质量意识,发挥质量优势占领市场的工作,行动较早,措施得力,效果显著。早在“六五”期间,工厂就积极推行了“以科研求发展,以质量求生存,以提高经济效益和社会效益为目的,创名牌,创第一流水平”的办厂方针。进入“九五”发展新时期,为了适应两个根本性转变,在激烈的市场竞争中求得不断发展和进一步壮大,工厂确立了“坚持改革,强化管理,创品牌,争一流,建成三大主体,为把工厂… 相似文献
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大亚湾核电站人因事件分析与预防对策 总被引:14,自引:2,他引:12
大亚湾核电站商运三年来,在运行,维护过程中发生的人因事件,总计368起,占事件总数的39%。人因事件主要发生在维修,试验,设备隔离和系统在线过程中,而以大修期间最为突出,文中分析了人因事件的根本原因,误操作,规程缺陷,未遵守规程,培训不足,通讯联络不够,工作组织不力等,提出了预防对策和处理原则,并列举了出相应人因事件的典型实例,最后指出,在预防人因事件过程中,最重要的环节是协调管理,选取最关键岗位 相似文献
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采用^3H标记抗原,抗体、蛋白激酶、受体、甾体激素等的液闪分析低能β方法,是近年来应用的超微量级(pg,10^-12)分析新技术,本文报道了应用这一技术作^3H标记TdR,cAMP-PDE,cAMP,cGMP,T,P,E2,E3,E0,F,DHT,DHA,Aldo,17-OHP等的测定与应用,及其临床意义。 相似文献
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以病理切片为依据,手术冷冻建立起10条狗股骨头缺血性坏死的早期模型,在术前和术后1,3,5,7,12,19,33天分别作^99mTc-MDP股骨头动态显像,测定股骨头血流灌注指数(FPI),以对股骨头缺血坏性死的早期血流变化进行探讨,结果显示,股骨头缺血性坏死的早期病理可分别作为骨髓组织水肿,髓腔内出血,脂肪溶解液化,肉芽组织及新骨形成等四期。骨动态显像后的FPI显示,手术侧股骨头血流灌注下降,术 相似文献
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In this paper,the toroidal field B of a tokamak produced by separate coils has been calculated from the basic electrodynamic theory.As an example,the toroidal magnetic field B(R) in TEXT-U tokamak is plotted.and the curve is fitted well to the analysis formula B(R)=B0R0/R with a precision of several percents. 相似文献
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循环对称非线性瞬态温度场的变分解法 总被引:1,自引:0,他引:1
工程中有大量的具有循环对称特点的温度场的求解问题。本文对具有循环对称条件的非线性瞬态温度场问题给出由泛函表达的方程及用有限元法计算的实例。本方法使具有循环对称特点的温度场的计算可在一个循环周期内进行,从而大量减少输入数据的准备工作,减少内存占用和计算时间。 相似文献
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为研究高温、高压介质对反应堆冷却剂泵的影响,应用商业计算软件ANSYS Workbench对其进行多场耦合数值模拟计算,得到核主泵内部流场、温度场及应力场分布。计算结果表明:类球形压水室不利于流体流动,内部流动十分复杂并存在明显回流。叶轮前盖板温度明显高于后盖板,前盖板平均温度达到530 K,而后盖板只有500 K。应力集中大都发生在前后盖板与叶片交接处,叶轮的等效应力最小值位于叶轮的后盖板轮毂侧,而最大值出现在叶轮出口与前后盖板交接位置;由于叶轮出口处叶片间的约束较小,而此处产生的热应力及离心力所产生的拉应力较大,使得叶轮出口后盖板处产生最大变形,为0.24 mm。 相似文献
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《Journal of Nuclear Science and Technology》2013,50(8):715-718
A planar hybrid undulator was constructed for the JAERI PEL. In order to evaluate the performance of the undulator, magnetic field of the undulator was mapped by a detailed field measurement system. The field map obtained experimentally was compared with the map calculated by computer. The undulator field was found to be sinusoidal in the longitudinal direction and almost flat In the transverse direction. The performance of the undulator was found out to be sufficient to lase the JAERI FEL, because the irregularity of the field pattern of the undulator is sufficiently small. 相似文献
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利用Z箍缩等离子体辐射源产生X射线可开展脉冲X射线辐照材料动力学响应及热力学效应研究,而试验面处的辐射功率密度是热力学效应研究中最关心的参数。本文针对Z箍缩产生的软X射线辐射功率密度场分布,以理论分析和数值模拟为手段,将Z箍缩软X射线辐射源分别等效为线光源和朗伯辐射光源,获得了2种等效情况下X射线辐射功率密度场的分布。分析表明,在线光源等效情况下,远场分布为球面分布,符合距离平方反比关系,而近场则近似圆柱面分布,符合距离反比关系;在朗伯辐射光源等效情况下,远场分布为球面余弦调制分布,而近场分布近似圆柱面分布。等效模型分析结果均表明:对于长度为2 cm的Z箍缩软X射线辐射体,当试验样品放置位置距离Z箍缩光源大于5 cm后,试验面处的辐射功率密度即可视为远场情况,符合距离平方反比关系。 相似文献
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R. D. Milroy H. Y. Guo A. L. Hoffman L. C. Steinhauer 《Journal of Fusion Energy》2007,26(1-2):123-126
A major concern for Rotating Magnetic Field (RMF) current drive of an FRC is that a transverse magnetic field tends to open
the field lines, thus compromising confinement. In recent FRC current drive experiments it was found that thermal confinement
is much improved when an antisymmetric RMF is applied, rather than the usual symmetric RMF. A field line tracking analysis
showed that with a combination of partial penetration and antisymmetric RMF, the field lines remain closed for larger ratios
of B
ω/B
e than was previously thought. In this paper the analysis is extended to more fully understand the boundaries of when and where
the field lines are expected to remain closed when antisymmetric RMF current drive is applied to an FRC. 相似文献
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组织等效正比计数器结构优化设计 总被引:1,自引:1,他引:0
为优化设计密闭式组织等效正比计数器(TEPC)结构,首先采用Maxwell软件对两种待选结构探测器的电场分布进行了模拟,初步确定出探测器主体为圆柱体加场管的结构。为了考察TEPC的电场分布的均匀性,研制了流气式TEPC,并设计实验对其电场分布进行了测试。基于流气式TEPC的结构参数,研制了TEPC装置,并对其探测器的电子学噪声水平进行了测试。实验结果表明,TEPC的电场分布均匀性、噪声水平等电子学性能基本满足辐射测量要求。 相似文献
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The toroidal field (TF) magnet system of EAST (HT-7U), which consists of 16 superconducting coils enclosed in steel cases, has been manufactured to generate the magnetic field of 3.5 T at the plasma center to maintain plasma in a tokamak configuration with a current up to 1 MA. The TF coils have an approximately D-shape geometry of 2.6 m wide and 4.0 m high, and operate at a maximum field of 5.8 T. The conductor used in the TF coil is NbTi/Cu cable-in conduit (CIC) conductor, and its operating current is 14.3 kA.In March 2006, the first cooling down of the EAST device has been carried out successfully. The total of TF magnet system has been cooled down from room temperature to 4.5 K, and the TF system has been energized up to 8.2 kA with 5 A/s ramp rate. In September 2006, full performances of the TF magnet system have been reached, and the device of EAST has delivered its first plasma. In addition, the TF magnet system has been routinely operated with a current maintained constant on a whole day basis, for a preliminary program of more than 500 shots.In this paper, the main parts of the design, developmental tests, and the fabrication and assembly of TF coils are described in detail. 相似文献
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Shaoshuai GUO 《等离子体科学和技术》2020,22(12):125301
In this paper, a novel solution mitigating the radio blackout problem is proposed, which improves existing traveling magnetic field (TMF)-based methods. The most significant advance lies in replacing the external injection with self-induced current, which does not require electrodes. The improved analytical model is derived to evaluate the electron density reduction taking into consideration the self-induced current for various TMF velocities. The plasma reduction performance is analyzed for several conditions including the total absence of injected current. The results show that the velocity may be used to trade off the injected current and, when sufficiently large, eliminates the need for an injected current while mitigating radio blackout. The effectiveness of this solution to the blackout problem is demonstrated in commonly used aerospace communication bands. With a field strength of less than 0.15 T, increasing the velocity from 40 m s−1 to 3100 m s−1 is all that is required to obviate the need for an injected current. Moreover, typical reduction ratios for electronic density tolerance (2, 1.9, 1.75 and 3 times for the L-, S-, C- and X-bands, respectively, at an altitude of 40 km) remain unchanged. Increasing the velocity of the TMF is much easier than injecting current via a metal electrode into a high-temperature flow field. The TMF method appears practical in regard to possible future applications. 相似文献
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XuXiao-Ming 《核技术(英文版)》1997,8(3):139-143
In order to study regular behaviors in high-energy nucleon-nucleon collisions,a representation of the vector potential Ai^a is defined with respect to the (a,i)-dependence in the SU(2) Yang-Mills classical mechanics,Equations of the classical infraed field as well as effective potentials are derved for the elastic or inelastic collision of two plane waves in a three-mode model and the decay of an excited spherically-symmetric field. 相似文献