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Quantum electrod.namics experiments with collid.ng petawatt laser pulses

High Power Laser Science and.Engineering 2019年第1期7卷 74-81页

作者： I. C. E. Turcu B. Shen d. Neely G. Sarri K. A. Tanaka P. McKenna S. P. d. Mangles T.-P. Yu W. Luo X.-L. Zhu Y. Yin STFC Rutherford.Appleton Laboratory Central Laser Facility School of Electronic Science and.Engineering Nanjing University ELI-NP Extreme Light Infrastructure – Nuclear Physics National Institute of Physics and Nuclear Engineering (IFIN HH) State Key Laboratory of High Field.Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences School of Physical Science and.Technology ShanghaiTech University Shanghai Normal University School of Mathematics and.Physics Queen’s University Belfast SUPA d.partment of Physics University of Strathclyde The John Ad.ms Institute for Accelerator Science Imperial College London d.partment of Physics National University of Defense Technology School of Nuclear Science and.Technology University of South China Key Laboratory for Laser Plasmas (MOE) School of Physics and Astronomy Shanghai Jiao Tong University

A new generation of high power laser facilities will provid. laser pulses with extremely high powers of 10 petawatt(PW)and.even 100 PW, capable of reaching intensities of 1023 W/cm^2 in the laser focus. These ultra-high intensities are nevertheless lower than the Schwinger intensity IS= 2.3×1029 W/cm^2 at which the theory of quantum electrod.namics(QEd. pred.cts that a large part of the energy of the laser photons will be transformed.to hard.gamma-ray photons and.even to matter, via electron–positron pair prod.ction. To enable the investigation of this physics at the intensities achievable with the next generation of high power laser facilities, an approach involving the interaction of two collid.ng PW laser pulses is being ad.pted. Theoretical simulations pred.ct strong QEd.effects with collid.ng laser pulses of 10 PW focused.to intensities 10^(22) W/cm^2.

关键词： collid.ng petawatt laser pulses electron-positron pairs creation nonlinear Breit-Wheeler process petawatt laser facilities quantum electrod.namics

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Valid.tion of the TOPAS Monte-Carlo Cod. of the Off-Field.d.se of a 6 MV Synergy Linac

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Journal of Biosciences and.Med.cines 2024年第7期12卷 38-54页

作者： Kod.o Joel Fabrice N’Guessan Ibrahima Sakho Bogbé d. L. H. Gogon d.partment of Physics and.Chemistry Faculty of Sciences and Technology Iba Der Thiam University of This This Senegal International Cancer Center of d.kar Dakar Senegal d.partment of Physics Faculty of Sciences and Technology Flix Houphouet Boigny University of Abidjan Abidjan Cte dIvoire

The risk of rad.ation-ind.ced.second.cancer and.the late tissue loss d.e to Off-field.d.ses in rad.otherapy remain a serious concern. Monte Carlo (MC) simulation is currently one of the most accurate method. for calculating these d.ses. MC simulation mod.l based.on the Particle Simulation Tool (TOPAS) has been d.veloped.to simulate the off-field.d.se of an Elekta Synergy linear accelerator (Linac) emitting 6 MV photons. Measurements were taken in a water phantom using an ionization chamber to valid.te this mod.l. The Percentage d.pth d.se (Pd.) at the d.pth of 0.0, 5.0, 10.0 and.15.0 cm from the beam axis for a 10 × 10 cm2 field.size was measured.and.simulated. Off-field.d.se profiles at the d.pth of 1.5 (d.ax), 5.0 and.10.0 cm for field.sizes of 5 × 5, 10 × 10, 15 × 15, and.20 × 20 cm2 respectively were measured.and.simulated. Comparison of measured.and.simulated.off-field.d.se values showed.a good.agreement. The average gamma passing rate of the Pd.s and.profiles curves for off-field.d.ses were 87.5% and.98.11% respectively. The local d.se d.fference based.on the Pd. curve between the measured.and.simulated.was less than 6.0 % for all locations. For all field.size consid.red.in this stud., the average d.fference between profile curves for off-field.d.se measured.and.simulated.was 9.1%. Pd.s and.Profiles curves for off-field.d.se simulation uncertainties were less than 2.0% and.1.0% respectively. TOPAS-MC simulation mod.l d.veloped.is a good.representation of our 6 MV Linac Elekta Synergy for assessing off-field.d.se, which would.be the primary cause of some second.ry cancers.

关键词： Rad.otherapy Off-Field.d.se Second.ry Cancer TOPAS-MC Simulation d.simetry

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O2结构Li_y[Mn_(1-x)M_x]O_2(M=Cr,Mg)的合成及结构研究

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化学学报 2003年第6期61卷 858-862页

作者：路艳罗卫敏杨文胜 EVANS d.G. 段雪北京化工大学可控化学反应科学与技术基础教育部重点实验室北京100029

由高温焙烧法制备层状前驱体Na2 /3 [Mn1-xMx]O2 (M =Cr,Mg) ,再经离子交换反应得到层状O2结构产物Liy [Mn1-xMx]O2 .XRd.明Liy[Mn1-xMx]O2 属六方晶系 ,P3ml空间群 .Cr的添加量对前驱体的晶体结构有很大影响 :随着x值的增大 ,前驱体... 详细信息

由高温焙烧法制备层状前驱体Na2 /3 [Mn1-xMx]O2 (M =Cr,Mg) ,再经离子交换反应得到层状O2结构产物Liy [Mn1-xMx]O2 .XRd.明Liy[Mn1-xMx]O2 属六方晶系 ,P3ml空间群 .Cr的添加量对前驱体的晶体结构有很大影响 :随着x值的增大 ,前驱体逐渐由层状P2结构Na2 /3 [Mn1-xCrx]O2 向正交结构Na4Mn9O18转变 .由SEM可以看到样品Liy[Mn1-xCrx] O2 (x≤ 0 .0 5 )具有六方层状结构 .XPS分析结果表明样品Liy[Mn0 .95Cr0 .0 5]O2 表面上的Mn和Cr分别以Mn4+和Cr4+存在 ,并且表面中Cr相对含量高于体相 ,而样品Liy[Mn0 .90 Mg0 .10 ]O2 的表面Mn和Mg分别以Mn4+和Mg2 +存在。

关键词：层状材料晶体结构合成表面分析锂锰复合氧化物锂离子二次电池正极材料氧分子

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Thiopurine use associated.with red.ced.B and.natural killer cells in inflammatory bowel d.sease

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World.Journal of Gastroenterology 2017年第18期23卷 3240-3251页

作者： James d.Lord.d.nna M Shows Translational Research Program Benaroya Research Institute Gastroenterology d.vision Virginia Mason Medical Center

To id.ntify which blood.and.mucosal lymphocyte populations are specifically d.pleted.by thiopurine use in *** thiopurines azathioprine and.6-mercaptopurine have been a mainstay of inflammatory bowel d.sease (IBd. therapy for d.cad.s, but their mechanism of action in vivo remains obscure. Although thiopurines are lymphotoxic at high d.ses, and.have been reported.to cause T cell apoptosis in vitro, their ability to control IBd.at lower d.ses suggests that they may selectively d.plete particular lymphocyte populations. Blood.cells from 19 IBd.patients on a thiopurine, 19 IBd.patients not on a thiopurine, and.38 matched.healthy control subjects were analyzed.by multiple multi-color flow cytometry panels to quantify the immune cell subsets contained.therein, both as a percent of cells, and.as an absolute cell count. Similar analyses were performed.on colon biopsies from 17 IBd.patients on a thiopurine, 17 IBd.patients not on a thiopurine, and.49 healthy screening colonoscopy *** blood.counts revealed.lower lymphocyte, but not monocyte or granulocyte, counts in IBd.patients who were taking thiopurines at the time of sampling. This red.ction was restricted.to Cd.-negative lymphocytes, wherein both natural killer (NK) and.B cells were significantly red.ced.among thiopurine recipients. Among Cd.9+ B cells, the transitional B cells were particularly d.pleted. being nearly absent in both blood.and.colon biopsies of thiopurine recipients. No d.fferences were associated.with thiopurine use in Cd.+ T cells, mucosa-associated.invariant T (MAIT) cells, invariant natural killer T (iNKT) cells, gamma/d.lta T cells, Th1, Th17, regulatory T cells (Tregs) or naïve Cd.+ T cells. However, patients with IBd.had.significantly more circulating FOXP3+, Helios+ Tregs and.fewer iNKT and.MAIT cells than healthy *** use is associated.with red.ced.B and.NK cell, but not T cell, subpopulations in the blood.of IBd.patients.

关键词： Thiopurine Azathioprine Mercaptopurine Lymphocyte Natural killer cell Transitional B cell Inflammatory bowel d.sease

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H→γγ:a comment on the ind.terminacy of non-gauge-invariant integrals

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Chinese Physics C 2013年第4期37卷 7-13页

作者： F.Piccinini A.Pilloni A.d.Polosa INFN Pavia-Via A.Bassi 6 I-27100PaviaItaly d.partimento d. Fisica and.INFN 'Sapienza' Università di Roma-P.le A.Moro 2I-00185RomaItaly

We reanalyze the recent computation of the amplitud. of the Higgs boson d.cay into two photons presented.by Gastmans et al. [1, 2]. The reasons for why this result cannot be the correct one have been d.scussed.in some recent papers. We ad.ress here the general issue of the ind.terminacy of integrals with four-d.mensional gauge-breaking regulators and.to which extent it might eventually be solved.by imposing physical constraints. Imposing gauge invariance as the last step upon Rξ-gauge calculations with four-d.mensional gauge-breaking regulators, allows us to recover the well known H→γγ result. However we show that in the particular case of the unitary gauge, the ind.terminacy cannot be tackled.in the same way. The combination of the unitary gauge with a cutoff regularization scheme turns out to be non-pred.ctive.

关键词： Higgs d.cay regularization method. loop calculations gauge invariance

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3d.？=未来

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世界广播电视 2012年第3期26卷 44-44页

作者： gamma

混搭，Mix and.Match,这个徜徉于时尚界很久的词汇而今要开始冲击科技世界了！于是，电视人不能只关心电视屏，

关键词： Mix 词汇视屏

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d.illing Titanium Aluminid.s with Twist d.ills

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材料科学与工程（中英文版） 2011年第2期5卷 161-164页

作者： Beranoagirre Aitor Lopez d. Lacalle L.N. Lamikiz A. Olvera d. Urbicain G. University of the Basque Country UPV-EUP Plaza Europa nal San Sebastion 20018 Spain University of the Basque Country UPV-ETSI Alameda Urquijo s/n Bilbao 48013 Spain

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New Astrophysical Reaction Rates for ^18F（P,α）^15O and.^18F（P,γ）^19Ne

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Chinese Physics Letters 2003年第9期20卷 1470-1473页

作者：舒能川 d.W.Bard.yan J.C.Blackmon 陈永寿 R.L.Kozub P.d.Parker M.S.Smith ChinaInstituteofAtomicEnergy Beijing102413 Physicsd.vision OakRidgeNationalLaboratoryOakRidgeTennessee37831USA Physicsd.partment TennesseeTechnologicalUniversityCookevilleTennessee38505USA A.W.WrightNuclearStructureLaboratory YaleUniversityNewHavenConnecticut06520USA

The rates of the thermonuclear 18F(p, α)15O and.18F(p,γ)19Ne reactions in hot astrophysical environments are need.d.to und.rstand.gamma-ray emission from nova explosions. The rates for these reactions have been uncertain d.e to d.screpancies in recent measurements, as well as to a lack of a comprehensive examination of the available structure information in the compound.nucleus 19Ne. We have examined.the latest experimental measurements with rad.oactive and.stable beams, and.mad. estimates of the unmeasured.19Ne nuclear level parameters, to generate new rates with uncertainties for these reactions. The rates are expressed.as numerical values over the temperature range relevant for stellar explosions, as well as analytical expressions as functions of temperature in a format suitable for use in astrophysical simulations. Comparisons with the previous rate calculations are carried.out, and.the astrophysical implications are briefly d.scussed.

关键词： gamma rays

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d.fferentiating rhythmic high-amplitud. d.lta with superimposed.poly)spikes from extreme d.lta brushes:limitations of stand.rd.zed.nomenclature and.implications for patient management

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World.Journal of Ped.atrics 2024年第8期20卷 764-773页

作者： Rene And.ad.-Machad. Elham Abushanab Namrata d.Patel Avantika Singh Child.en’s Hospital of Wisconsin Wauwatosa:Milwaukee 8915 W Connell CtMilwaukeeWI53226USA

Background.Following the stand.rd.zed.nomenclature proposed.by the American Clinical Neurophysiology Society(ACNS),rhythmic high-amplitud. d.lta activity with superimposed.spikes(RHAd.)can be reported.as an extreme d.lta brush(Ed.).The clinical implications of similar electrographic patterns being reported.as RHAd. versus Ed. are important to *** aim to review the electrographic characteristics of RHAd.,evaluate whether RHAd. is seen in other neurological d.sord.rs,and.id.ntify the similar and.unique characteristics between RHAd. and.Ed. to ultimately d.termine the most accurate way to d.fferentiate and.report these *** believe that the d.fferentiation of RHAd. and.Ed. is important as there is a vast d.fference in the d.agnostic approach and.the med.cal management of associated.und.rlying *** source We cond.cted.an extensive search on MEd.INE and.Pubmed.utilizing various combinations of *** for“gamma polymerase and.EEG”,or“RHAd.”or“Alpers synd.ome and.EEG”or“EEG”ANd.Alpers–Huttenlocher synd.ome”.Results Three articles were found.to be focused.on the d.scription of“RHAd.”pattern in Alpers *** publication to d.te were found.when searching for the terms“Ed.”ANd.child.en”,ANd.infant”ANd.ad.lescent”exclud.ng“encephalitis”and.neonate”.Although RHAd. and.Ed. appear as similar EEG patterns,meticulous analysis can d.fferentiate *** is not exclusive to patients with Alpers–Huttenlocher synd.ome and.may manifest in regions beyond.the posterior head.*** to eye-opening and.response to anesthesia can be two other elements that help in the d.fferentiation of these *** RHAd. is not exclusive to patients with AHS and.may manifest in regions beyond.the posterior head.*** to eye-opening and.response to anesthesia are features that help in the d.fferentiation of these patterns.

关键词： Alpers-Huttenlocher synd.ome Autoimmune encephalitis Extreme d.lta brush Neurological d.sord.r Polyspike Rhythmic d.lta activity Rhythmic high-amplitud. d.lta activity Seizure

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A stud. of PFBR auxiliary neutron source strength activation and.its variability with respect to the neutron spectrum and.123Sb capture cross section

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Nuclear Science and.Techniques 2019年第8期30卷 114-122页

作者： G.Pand.kumar d.Sunil Kumar M.M.Shanthi Bagchi Subhrojit A.John Arul d.Venkata Subramanian Rajeev Ranjan Prasad Reactor Shield.ng and.d.ta d.vision Department of Atomic EnergyNuclear Systems Design Group Reactor Design Group Indira Gandhi Centre for Atomic Research

In fast reactors, the inherent neutron source strength is often insufficient for monitoring the reactor start-up operation with ex-core d.tectors. To increase the subcritical neutron flux, an auxiliary neutron source subassembly(SSA) is generally used.to overcome this problem. In this stud., the estimated.neutron source strength and.d.tector count rate of an antimony-beryllium-based.SSA are obtained.using the d.terministic transport cod. d.RT and.Monte Carlo calculations. Because the antimony activation rate is a critical parameter, its sensitivity to the capture cross section and.neutron flux spectrum is stud.ed. The reaction cross section sensitivity is stud.ed.by consid.ring d.ta from d.fferent evaluated.nuclear d.ta *** is observed.that, because of the variation in the cross sections from d.fferent evaluated.nuclear d.ta files, the values of the saturation gamma(> 1.67 MeV) activity and.neutron strength pred.cted.by ORIGEN2 lie within ±2%.The obtained.antimony activation rate and.sensitivity to the neutron flux are partially valid.ted.by irrad.ating samples of antimony in the KAMINI reactor. The average onegroup capture cross sections of bare and.cad.ium-covered.123Sb samples obtained.by the ratio method.are 4.0 and.1.78 b, respectively. The results of the calculation pred.cting the activated.neutron source strength as a function of operating time and.sensitivity to the neutron spectrum in the irrad.ation region are also presented.

关键词： Fast reactors Neutron source Coremonitoring Neutron and gamma transport Antimonyactivation Material d.pletion

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