Nuclear Deformation Effect on the J/psi Suppression

The nuclear deformation effect on the J/psi suppression in U-U central collisions at 200 AGeV/c is investigated by the hadron and string cascade model, JPCIAE. We found that the J/psi suppression is nearly decreased by a factor of two when the major axes of both deformed nuclei are changed from along the beam direction to perpandicular to the beam direction.     

低剂量X射线照射对J774A.1细胞IL-12和 p38 MAPK表达的影响

通过检测低剂量辐射(LDR)对J774A.1细胞株中白细胞介素12(IL-12)及p38丝裂原活化蛋白激酶(p38 MAPK)的影响,以研究LDR辐射免疫效应的机制.分别采用流式细胞术和ELISA检测了p38 MAPK、IL-12 蛋白水平的变化.结果表明,75mGy X射线照射后,J774A.1细胞分泌IL-12量在照射后2、4、8h升高(p<0.05),随后即开始下降至恢复假照射水平;而p38 MAPK也于照射后2h出现升高,两者在发生时间上呈现一致性.结果显示LDR引起IL-12表达增加,而p38 MAPK传导通路可能在其中发挥作用,为低剂量辐射增强细胞免疫功能提供了实验依据.     

法国—体化压水堆C.A.P述评

本文简要介绍法国一体化压水堆 C.A.P.的结构、非能动安注系统和主要特点。C.A.P.布置紧凑,自然循环能力强,固有安全性好,建造周期短,造价低,已成功地用于法国第二代攻击型核潜艇,适用于小型核动力,有重要参考价值.     

Could the New Absorption Cross Section of J/psi Change the Aspect of Nuclear Absorption Mechanism

The enlarged new absorption cross section of J/psi by pion and rho mesons were put into the hadron and string cascade model, JPCIAE, and the J/psi suppression factors in p-A, O-U, S-U and Pb-Pb minimum bias collisions at 200 AGeV/c were calculated with nuclear absorption mechanism only. The results seem to indicate that, with new enlarged cross section it is still hard to change the aspect that nuclear absorption itself could not easily account for the J/psi anomalous suppression in Pb-Pb collisions.     

A Program for the Evaluation of the Difference Statistic(D)

Fromanaccountingviewpointinnuclearmaterialsafeguards,itisnecessaryfortheevaluationoftheMUFreportedbyfacility.ThequantityDisanestimateofthebiasinMUFofthefacility.TheDstatisticcanberegardedastheinspector'sestimateofthedifferencebetweentheoperator'sstatedM…     

A Data File Relative to Level Density (CENPL.NLD.LRD-2)

1 Average Neutron Resonance Parameters and Cumulative Number of Low Lying Levels The average level spacing D_0 of s-wave neutron at the neutron separation energy B_n and the cumulative number N_0 of low lying levels are the most basic data in the nuclear level density researches. The D_0, as well as the neutron strength function S_0, radiative capture width GW_0 etc. for s-wave neutron at B_n are major parameters describing the mean properties in the resonance region. It is necessary and important to estimate the reliable D_0 and N_0 values     

高温高压动水回路中A106Gr.B和A672Gr.B60耐冲蚀作用的研究

碳钢和低合金钢由于Cr含量较低,易发生流动加速腐蚀,对安全产生严重影响。现阶段最先进的第三代核电技术AP1000使用Cr含量较高的A672Gr.B60代替A106Gr.B作为供水管的材料来减小流动加速腐蚀(FAC)的影响。试验采用腐蚀失重、X射线光电子能谱(XPS)、扫描电镜(SEM)和X射线能量色散谱(EDS)等方法来分析流速、碱化剂以及物质组成对A672Gr.B60和A106Gr.B的影响。经336h的实验,结果显示A672Gr.B60较A106Gr.B具有更好的耐冲蚀性能,氧化膜更致密,不易脱落。使用乙醇胺(ETA)作为碱化剂相比于氨水能更好地降低FAC,也能使氧化膜更加致密。流速的变化会影响氧化物颗粒的分布、大小、形状,也会影响氧化膜的厚度。实验生成的氧化膜主要成分为Fe3O4。     

Study on the Manufacture Technology of the Zirconia Tubes Ⅲ.Research on the Slip Casting Process of the Zirconia Tubes

ThepropertiesofZrO2·Y2O3·Gd2O3slipwithintermediatediameter(therawmateri-alsunder1μmindiameterexceed60%)arestudiedinthepaper.Theslipcastingisper-formedusingplastermould.Itisfoundthatseveralfactors,includingthepHvalueofsus-pensionslip,theconcentrationofd…     

A Prototype of the Read-out Subsystem of the BESIII DAQ Based on PowerPC

1 Overview of the data acquisi-tion system for BES IIIAfter having run successfully for more than tenyears, the BEPC e+ e- collider will be upgradedfor higher luminosity, which will be increased to1033 cm-2 ·sec-1 [1]. Therefore, its detector BESII willbe upgraded to BESIII in order to take advantage ofthis increased luminosity, named BESIII.Trigger rate and event size define the performance re-quirements for the data acquisition (DAQ) system. Forpeak luminosity, we expect a L1 t…     

A Comparison of the Maximum Entropy Method of Analysis with the Exciton Model Plus the Master Equation

The maximum entropy method of analysis is successful in fitting experimental data.In order to reveal the underlying physics,this method is applied in comparison with the conventional approach,i.e the exciton model plus the master equation,to three cases.It is found that both approaches produce almost equally good fits to spectra,and yield almost the same average exciton numbers. This implies that there must be similar physical ideas behind the two approaches,and it should be safe to use the maximum entropy method of analysis to fit data or to estimate reaction cross sections.     

The definition of the roentgen in the “Recommendations of the International Commission on Radiological Units. 1953”

The contradictions found in the definitions of the roentgen as a unit of X- and γ-radiation are expounded and criticized. The definition accepted in the USSR of the roentgen as the unit of physical dose\((\frac{{OST}}{{VKS}}7623)\) differs from those in the International Recommendations and of the Congresses (Stockholm 1928 and Chicago 1937), where the roentgen is considered as the unit of dose, and not the physical dose. This has occasioned much confusion as to the physical content of the phenomena which the roentgen was intended to measure. An attempt was made in the 1953 Recommendations to resolve these difficulties, but this cannot be considered successful. The basic fault in the definition of the roentgen, which is that it “measures the amount of X- or γ-radiation” is retained. The definition given in the Recommendations of the amount of radiation as the time-integral of the intensity leads to the concept of the amount of radiation as being a flux density at a point, i.e., it adds a third variant to the dose concept, which further confuses the issue. The paper presents the requirements which the definitions of the basic units for measuring ionizing radiations — the roentgen and its equivalents — must satisfy.     

A Prototype of the Read-out Subsystem of the BESⅢ DAQ Based on PowerPC

This article describes the prototype of the read-out subsystem which will be subject to the BESⅢ data acquisition system. According to the purpose of the BESⅢ, the event rate will be about 4000 Hz and the data rate up to 50 Mbytes/sec after Level 1 trigger. The read-out subsystem consists of some read-out crates and a read-out computer whose function is to initialize the hardware, to collect the event data from the front-end electronics after Level 1 trigger, to transfer data fragments to the computer in online form through two levels of computer pre-processing and high-speed network transmission. In this model, the crate level read-out implementation is based on the commercial single board computer MVME5100 running the VxWorks operating system.The article outlines the structure of the crate level testing platform of hardware and software. It puts emphasis on the framework of the read-out test model, data process flow and test method at crate level. Especially, it enumerates the key technologies in the process of design and analyses the test results. In addition, results which summarize the performance of the single board computer from the data transferring aspects will be presented.     

J005A电磁波屏蔽织物对电磁脉冲辐照后小鼠血脑屏障的影响

医疗、科研和国防电子仪器设备以及计算机、手机、微波炉等电磁波在生活用具的广泛应用,已极大地造福于人类。然而,电磁波的应用也给人类带来了危害。电磁波虽不引起物质的电离,但其能引起分子或原子的振动并改变电子能级。已有研究表明,电磁辐射如电磁脉冲(Electromagnetic pulse,EMP)会引起小鼠和大鼠的脑神经递质代谢异常,使它们的学习能力和记忆能力下降,也会影响麻醉大鼠的脑电波。对大鼠的免疫系统、生殖系统与内分泌系统也有一定影响。     

A new measurement of the 429 keV 15N(p, αλ) 12C resonance. Applications of the very narrow width found to 15N and 1H depth location: II. Applications

The unexpectedly narrow width Γ_p = 120 eV or Γ_N¹⁵ = 1.8 keV of this resonance opens quite new possibilities for its use in ¹⁵N or ¹H depth location and for hydrogen adsorption studies using ¹⁵N beams. Resonance depth profiling of ¹⁵N is possible with much better near-surface depth resolution than thought until recently. In ¹H resonance depth profiling the indeep background originating from the surface contamination peak is also much smaller than previously assumed. These features are illustrated by ¹⁵N self-diffusion experiments in NbN films and by ¹⁵N adsorption experiments on copper single crystals in ultrahigh vacuum. The strong effect of Doppler broadening on the actual ultimate near-surface depth resolution of hydrogen depth profiling with ¹⁵N beams is discussed as well as the use of this resonance for the direct measurement, based on the Doppler effect, of the vibration speed distribution of hydrogen atoms adsorbed on clean surfaces.