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ICRU 95号报告:外照射实用量及其对剂量学的影响

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辐射防护 2023年第1期43卷 11-16页

作者： Hans Menzel Thomas Otto Heidelberg Germany and ICRU cern 1211 Geneva 23Switzerland and ICRU

国际放射防护委员会(ICRP)提出了“防护量”这一概念。最常用的防护量,即有效剂量E,用于设定照射限值,并在实用辐射防护中使用,以实现最优化原则。然而,有效剂量不是一个可测量的量,基于此国际辐射单位与测量委员会(ICRU)为外照射的剂... 详细信息

国际放射防护委员会(ICRP)提出了“防护量”这一概念。最常用的防护量,即有效剂量E,用于设定照射限值,并在实用辐射防护中使用,以实现最优化原则。然而,有效剂量不是一个可测量的量,基于此国际辐射单位与测量委员会(ICRU)为外照射的剂量测定提出了一个可测量的量,即实用量,用于估计有效剂量。目前使用的实用量定义于20世纪80年代,当时核工业是职业辐射防护的主要关注点。当前,在其他辐射领域,特别是高能辐射,实用量的不足之处变得很明显:可能高估或低估有效剂量。因此,ICRU和ICRP在全面研究的基础上,为外照射的剂量测定提出了新的实用量,以克服上述缺点。实用量的新定义与防护量(包括有效剂量)的定义更具相关性,特别是使用了相同的仿真体模。当前提出的实用量通过缩小防护量与实用量之间的定义差异简化了辐射防护量体系,并从整体上改进了对有效剂量的估计。本文讨论了提出的新实用量对实际剂量测定的影响。

关键词：剂量学实用量防护量有效剂量

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Model and Information Abstracion for Description—Driver Systems

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International Conference on Computing in High Energy and Nuclear Physics 2001年第1期 540-543页

作者： FloridaEstrella ZsoltKovacs 等 CentreforcomplexCooperativeSystems UWEFrenchayBristolBS161QYUK EPdivision CERNGenevaSwitzerland

A Crucial factor in the creation of adaptable systems dealing with changing requirements is the suitability of the underlying technology in allowing the evolution of the system.A reflective system utilizes an open architecture where implicit system aspects are reified to become explicit first-class(meta-data)*** implicit system aspects are often fundamental structures which are inaccessible and immutable,and theri reification as meta-data objects can serve as the basis for changes and extensions to the system, making it *** address the evolvability issue,this paper proposes a reflective architecture based on two orthogonal abstractions-model abstraction and information *** this architecture the modeling abstractions allow for the separation of the description meta-data from the system aspects they represent so that they can be managed and versioned independently,asynchronously and explicitly.

关键词：信息处理驱动系统四层模型结构

Querying Large Physics Data Sets Over an Information Grid

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International Conference on Computing in High Energy and Nuclear Physics 2001年第1期 663-667页

作者： NigelBaker ZsoltKovacs 等 CentreforComplexCooperativeSystems UWEFrenchayBristolBS161QYUK EPDivision CERNGenevaSwitzerland

Optimising use of the Web(WWW) for LHC data analysis is a complex problem and illustrates the challenges arising from the integration of and computation across massive ampunts of information distributed *** the right piece of information can,at times,be extremely time-consuming,if not impossible,SO-called Grids have been proposed to facilitate LHC computing and many groups have embarked on studies of data replication,data migration and netwroking *** aspects such as the role of moddleware' for Grids are emerging as requiring *** paper positions the need for appropriate middleware that enables users to resolve physics queries across massive data *** identifies the role of meta-data for query resolution and the importance of Information Grids for high-energy physics analysis rather than just computational or Data Grids,This paper identifies software that is being implemented at cern to enable the querying of very large collaborating HEP data-sets,initially being employed for the construction of CMS detectors.

关键词：高能物理物理数据库信息网络

200MHZ SUPERCONDUCTING NB-CU CAVITIES FOR MUON ACCELERATION

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200MHZ SUPERCONDUCTING NB-CU CAVITIES FOR MUON ACCELERATION

New Materials for Vacuum Chambers in High Energy Physics

CCAST“射频超导及其应用”研讨会

作者： R.L.Geng P.Barnes D.Hartill H.Padamsee J.Sears S.Calatroni E.Chiaveri R.Losito H.Preis LEPP Cornell UniversityIthacaNY 14853USA LEPP Cornell UniversityIthacaNY 14853USA LEPP Cornell UniversityIthacaNY 14853USA LEPP Cornell UniversityIthacaNY 14853USA LEPP Cornell UniversityIthacaNY 14853USA cern GenevaSwitzerland cern GenevaSwitzerland cern GenevaSwitzerland cern GenevaSwitzerland

＜正＞As a first step toward a muon collider, a neutrino factory is being actively studied. The neutrino factory calls for nearly 500 meters of 200 MHz SRF cavities to provide 7.5 GeV. The desired gradient is in the range of 15 -17 MV/m at a Q0 of 6 ×109. Nb-Cu is the technology of choice driven mainly by the cost concern. A Cornell/cern collaboration was established to address the unique challenges imposed by the large size of these cavities. A 200 MHz single cell elliptical Nb-Cu cavity has been fabricated and tested at 4.2 K and at 2.5 K in a vertical dewar fitted in a radiation shielded pit, 5 m deep and 2.5 m in diameter. The low field Q0 reached 1.5 ×1010 at 4.2 K. Two multipacting barriers show up at Eacc = 3 MV/m and 1 MV/m. Both barriers can be processed through. Helium processing is effective in reducing field emission and improving accelerating gradients by a factor of as much as 2. Eacc reached 11 MV/m, or 75% of the desired gradient, at a Qo of 6 ×108. The major challenge is the Q-drop of the cavity, which shows a much stronger field dependence rate than expected. This is to be addressed by further film studies, including bias sputtering.

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World Journal of Mechanics 2014年第3期4卷 71-78页

作者： Cédric Garion Vacuum Surfaces and Coatings Group Technology Department CERN CH-1211 Geneva 23 Meyrin Switzerland

Vacuum chambers must fulfil ultra-high vacuum requirements while withstanding thermo-mechanical loads. This is particularly true in high energy particle accelerator where interactions of particles with matter may induce thermal load, material activation, background… The choice of the material of the vacuum chamber is crucial for the final application. Metals such as stainless steel, copper and aluminium are usually used. Even with outstanding mechanical and physical properties, beryllium is used for very specific applications because of its cost and *** such as alumina are usually used for fast magnet vacuum chambers. With the next generation of high energy physics accelerator generation such as CLIC and TLEP, the problematic of high cyclic thermal load induced by synchrotron radiation is raised. This paper aims at defining some figures of merit of different materials with respect to several load scenarios and presents briefly their vacuum compatibility.

关键词： Vacuum Chamber Figure of Merit Transparency Radiation Length Carbon Beryllium

Roles of abscisic acid and gibberellins in maintaining primary and secondary dormancy of Korean pine seeds

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Journal of Forestry Research 2020年第6期31卷 2423-2434页

作者： Yuan Song Jiaojun Zhu Qiaoling Yan Qingyuan Forest cern Chinese Academy of SciencesShenyang 110016People’s Republic of China CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyShenyang 110016People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Primary dormancy of seeds of Korean pine(Pinus koraiensis *** Zucc.)after dispersal in the autumn and the induction of secondary dormancy the fi rst summer following seed dispersal limit the regeneration of mixed broadleaved Korean pine forests in Northeast *** study was to determine how changes in the levels of abscisic acid(ABA)and gibberellic acid(GA)maintain primary and secondary dormancy of Korean pine seeds under germination *** transferred seeds with one of fi ve primary dormancy states or three secondary dormancy states to germination conditions and measured changes in the levels of ABA,GA 1+3(GA 1 and GA 3)and GA 4+7(GA 4 and GA 7)in the seed coat,megagametophyte and embryo during *** coat ABA levels in primary dormant seeds(PDS)and ABA levels in various parts of secondary dormant seeds(SDS)gradually declined during incubation but were still higher than in seeds for which dormancy was progressively *** 4+7 and GA 1+3 levels in embryos greatly decreased 35%and 24%,respectively,during incubation of SDS,and thus,the ratio of ABA to GA 4+7 in embryos and megagametophytes signifi cantly *** ratio of ABA to GA 1+3 in various parts of SDS increased slightly during *** contrast,in seeds for which secondary dormancy was already released,GA 4+7 and GA 1+3 levels in the embryo,GA 4+7/ABA ratio in the embryo and seed coat,and the GA 1+3/ABA in the embryo and megagametophyte signifi cantly increased during *** was no trend in the changes in the levels of ABA,GA 4+7 or GA 1+3 in embryos and megagametophytes of PDS or the levels of GA 4+7 or GA 1+3 in megagametophytes of SDS during *** results suggest that high ABA levels in the seed coat maintain primary dormancy of Korean pine *** of secondary dormancy involves a reduction of GA 4+7,GA 1+3,GA 4+7/ABA,and GA 1+3/ABA and the retention of high ABA levels.

关键词： Abscisic acid Gibberellic acid 4 and acid 7 Gibberellic acid 1 and acid 3 Korean pine Primary dormancy Secondary dormancy

Probing new physics in dimension-8 neutral gauge couplings at e^+e^-colliders

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Science China(Physics,Mechanics & Astronomy) 2021年第2期64卷 2-26页

作者： John Ellis Hong-Jian He Rui-Qing Xiao Department of Physics Kings College LondonStrandLondonWC2R 2LSUK Theoretical Physics Department CERNCH-1211Geneva 23Switzerland NICPB Rävala 10Tallinn10143Estonia Tsung-Dao Lee Institute&School of Physics and Astronomy Shanghai Key Laboratory for Particle Physics and CosmologyShanghai Jiao Tong UniversityShanghai200240China Institute of Modern Physics and Department of Physics Tsinghua UniversityBeijing100084China center for High Energy Physics Peking UniversityBeijing100871China

Neutral triple gauge couplings(nTGCs)are absent in the standard model effective theory up to dimension-6 operators,but could arise from dimension-8 effective *** this work,we study the pure gauge operators of dimension-8 that contribute to nTGCs and are independent of the dimension-8 operator involving the Higgs *** show that the pure gauge operators generate both ZγZ^*and Zγγ^*vertices with rapid energy dependence∝E^5,which can be probed sensitively via the reaction e^+e^-→Zγ.We demonstrate that measuring the nTGCs via the reaction e^+e^-→Zγfollowed by Z→qq decays can probe the new physics scales of dimension-8 pure gauge operators up to the range(1-5)TeV at the CEPC,FCC-ee and ILC colliders with s~(1/2)=(0.25-1)TeV,and up to the range(10-16)TeV at CLIC with s~(1/2)=(3-5)TeV,assuming in each case an integrated luminosity of 5 ab~(-1).We compare these sensitivities with the corresponding probes of the dimension-8 nTGC operators involving Higgs doublets and the dimension-8 fermionic contact operators that contribute to the e^+e^-Zγvertex.

关键词： neutral triple gauge couplings new physics beyond the standard model effective field theory e^+e^-colliders

Leaf nitrogen and phosphorus resorption of woody species in response to climatic conditions and soil nutrients： a meta-analysis

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Journal of Forestry Research 2018年第4期29卷 904-912页

作者： Tao Yan Jiaojun Zhu Kai Yang CAS Key Laboratory of Forest Ecology and Management Institute of Applied Ecology Shenyang 110016 People' s Republic of China Qingyuan Forest cern Chinese Academy of Sciences Shenyang 110016 People's Republic of China University of Chinese Academy of Sciences Beijing 100049 People's Republic of China

Nutrient resorption before abscission is an important nutrient conservation mechanism regulated by climatic conditions and soil nutrients. However, our current understanding of leaf nutrient resorption is primarily derived from site-specific studies or from the use of greenleaf nutrient concentrations to represent those in soils. It remains unknown how nutrient resorption responds to natural soil-nutrient concentrations at a global scale. The effects of plant functional groups, climatic conditions, and soil nutrients and their interactions on leaf nutrient resorption are also unknown. In this study, we established a global database derived from 85 published papers, including 547 reports of nitrogen and phosphorus resorption efficiency （NRE and PRE）, climatic factors （LAT, latitude; MAT, mean annual temperature; MAP, mean annual precipitation） and soil-nutrient data （STN, soil total nitrogen; STP, soil total phosphorus） across 111 research sites. The results demonstrated that mean NRE and PRE were 48.4 and 53.3%, respectively. NRE of trees was lower than those of shrubs. NRE and PRE of coniferous species were both higher than those of broad-leaved species. Evergreen species had higher PRE than did deciduous species. NRE was negatively related to STN, but PRE and STP were not related. Both NRE and PRE decreased with increasing MAT and MAP but increased with increasing LAT. Plant functional groups, climate and soil nutrients jointly explained 22 and 32% of the variations in NRE and PRE, respectively. It is important to note that climate （especially MAT） explained 12 and 29% of the variations in NRE and PRE, respectively, implying that continuing global warming will exert an increasingly profound influence on plant nutrient cycles.

关键词： Global Climate change Nutrient resorptionefficiency Tree Shrub

Probing the scale of new physics in the ZZγ coupling at e^+e^- colliders

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Chinese Physics C 2020年第6期44卷 55-86页

作者： John Ellis Shao-Feng Ge Hong-Jian He Rui-Qing Xiao Department of Physics Kings College LondonStrandLondon WC2R 2LSUKTheoretical Physics DepartmentCERNCH-1211 Geneva 23SwitzerlandNICPBRävala 1010143 TallinnEstonia Tsung-Dao Lee Institute&School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Institute of Modern Physics Tsinghua UniversityBeijing 100084China center for High Energy Physics Peking UniversityBeijing 100871China

The Z Zγtriple neutral gauge couplings are absent in the Standard Model(SM)at the tree *** receive no contributions from dimension-6 effective operators,but can arise from effective operators of *** study the scale of new physics associated with such dimension-8 operators that can be probed by measuring the reaction e^+e^-→Zγ followed by Z→■■,vv decays,at future e^+e^- colliders including the CEPC,FCC-ee,ILC and *** demonstrate how angular distributions of the final-state mono-photon and leptons can play a key rôle in suppressing SM *** further demonstrate that using electron/positron beam polarizations can significantly improve the signal *** find that the dimension-8 new physics scale can be probed up to the multiTeV region at such lepton colliders.

关键词： neutral triple gauge coupling beyond Standard Model e^+e^-colliders