Assuming that the Quantum Chromodynamics(QCD)system reaches a state of thermal equilibrium,based on the universality of critical behavior,by mapping the variables of the three-dimensional Ising model onto the QCD phase plane,we investigate the density distributions of fifth-,seventh-,and ninth-order generalized susceptibilities of the net baryon number on the phase plane,as well as their dependence on the net-baryon chemical potential along the chemical freeze-out line.When only the leading-order critical contribution from the Ising model is considered,approaching the critical point from the low net-baryon chemical potential region,the generalized susceptibilities all exhibit a structure characterized by a negative dip fol-lowed by a positive peak.Upon incorporating the next-leading-order critical contribution,the presence of the negative dip be-comes dependent on the distance to the phase boundary and the scaling parameters corresponding to the critical region.However,the positive peak structure remains consistently present and unaffected by these factors.In comparison to the negat-ive dip,the positive peak structure can be considered a more robust feature indicative of the critical point.
Nuclear mass plays an important role on nuclear structure and nuclear astrophysics.For the exotic nuclei far away from the stability valley,at least three orders of the magnitude for the half lives of emitters might be arisen by hundreds of keV difference of the separation energy given by the nuclear mass.At present,149Lu is the proton emitter with shortest lives dis-covered in experiments.The separation energies of the neighbor undetected nuclei will influence the nucleosynthesis path.To this end,we apply Artificial Neural Network(ANN)model and Bayesian Neural Network(BNN)model to constrain the pro-ton separation energy,and the practice indicates that the two approaches have the overfitting and precision problems respect-ively.In order to improve the precision and mitigate the overfitting problem,based on BNN model,and take the uncertainties of the labels and the ensemble uncertainty of the models into account simultaneously,we develop the BNN-Beihang(BH)model.The uncertainties of 148Lu and 160-161Re predicted by the model decreased to less than 100 keV for the first time.These results will effectively improve the precision of the theoretical predictions to the Lu and Re chain proton emitters' lives.
The deep inelastic collision(DIC)process in the 18O+238 U system at an incident energy of 8.5 MeV/u has been in-vestigated by combining the improved quantum molecular dynamics(ImQMD)model with the GEMINI++statistical decay model.Analysis of the total kinetic energy versus the mass distribution of the reaction products confirms that projectile-like fragments are produced predominantly via the DIC mechanism.In this study,key dynamical observables—including differen-tial cross sections,emission angles,and projectile-target contact times—have been extracted for selected projectile-like iso-topes such as carbon(C),oxygen(O),and fluorine(F).The simulations reveal that the differential cross sections of neutron-rich projectile-like fragments peak sharply in the forward angular region,reaching a maximum near 0°.Furthermore,a system-atic trend is observed:as the neutron-to-proton(N/Z)ratio of the projectile-like products increases,the projectile-target con-tact time becomes longer,while the average emission angle shifts toward smaller values.This behavior originates from the prolonged rotational motion(exceeding 200 fm/c,spanning approximately 90°)of the neck-shaped dinuclear system formed during the collision,which facilitates extensive nucleon exchange.Notably,several multi-nucleon transfer channels—specific-ally,the transfer of 1p+2n,1p+3n,and 1p+4n from the 238U target to the 18O projectile—are characterized by positive Q-val-ues(4.212,3.492,and 5.805 MeV,respectively).These exothermic processes significantly enhance the production probabilit-ies,leading to increased differential cross sections for the 21-23F isotopes.The simulation results agree satisfactorily with available experimental data,validating the reliability of the combined ImQMD+GEMINI++approach for describing such heavy-ion collision dynamics.Our findings elucidate the underlying microscopic dynamics of DIC and provide useful theoret-ical insights for future low-energy nuclear physics experiments,particularly those employing next-generation zero-degree spectrometers designed for the efficient production of secondary beams of exotic nuclei.
Based on neutron thermal scattering theory,a neutron thermal scattering cross-section calculation module(ThermalXS)was developed independently in the advanced evaluated nuclear cross section processing program AXSP.Differ-ent types of neutron thermal scattering cross-sections were calculated using the thermal scattering law files of nuclides such as U,H,and Zr.To verify the reliability of the ThermalXS module for thermal neutron calculations,its results were compared with those obtained from the THERMR module of NJOY2016 program.Compared with the THERMR module,the ThermalXS module employs an adaptive incident energy grid technology,which ensures higher accuracy of thermal scatter-ing cross-sections for metal hydrides.Additionally,it is capable of processing thermal scattering law data incorporating one-phonon corrections.In this study,the variations of the thermal scattering cross-sections of graphite across the ENDF/B-Ⅶ.1,ENDF/B-Ⅷ.0,and ENDF/B-Ⅷ.1 evaluated nuclear data libraries were systematically analyzed and validated against ex-perimental values.The results show that the thermal scattering cross section of graphite in ENDF/B-Ⅷ.1,modified using the one-phonon model,shows better agreement with experimental data compared to the graphite crystal model.The primary reas-on is the elimination of the incoherent approximation in the cross-section calculation.The calculated thermal scattering cross section of reactor graphite in ENDF/B-Ⅷ.1 exhibits a trend of increasing with porosity,yet it remains significantly lower than the experimental data for graphite with porosity.
The feasibility study of 18-month fuel management of 157 core was carried out by using the gadolinium rod optim-ization technique.The Equilibrium Cycle fuel management of gadolinium rod optimization scheme was designed,and the main calculation results of the base scheme and gadolinium rod optimization scheme were given.The results show that the gadolinium rod optimization scheme can meet the design criteria of 18-month refueling cycle operation by rationalizing the ar-rangement of fuel assemblies and burnable poison.In the same cycle length,the average discharge burnup of the core with gadolinium rod optimized fuel management design is higher,the fuel usage cost is less,and the economy is better.
The AMPT(A Multi-Phase Transport)model is employed to investigate the elliptic flow(v2)of charged hadrons produced in d-Au collisions at a collision energy of 200 GeV.The influence of non-flow sources,including jet fragments and resonance decays,on v2 in this small collision system is systematically examined.A non-flow contribution subtraction meth-od is adopted,in which the charged hadron yield in central d-Au collisions(centrality 0～5％)is subtracted from that in peri-pheral d-Au collisions(centrality 60％～100％or 80％～100％)or in pp collisions at the same collision energy,in order to sup-press non-flow effects.The dependence of the extracted v2 on different subtraction schemes is analyzed.It is found that theor-etical calculations with non-flow contributions removed provide an improved description of existing experimental data,while the results obtained from different subtraction schemes show good consistency.The study demonstrates that the choice of peri-pheral d-Au collisions or pp collisions as the subtraction reference has only a minor influence on the final theoretical predic-tions.These results provide a theoretical basis for the removal of non-flow contributions in small collision systems and offer useful guidance for related experimental analyses.
In this paper we evaluate typical values of magnetic energy and electromagnetic angular momentum of atomic nuclei with very simple scenarios,for the first time.We point out possible situations in which magnetic en-ergy and angular momentum might play essential roles in nuclear physics.
近二十年来，中子星表面由 12 C+ 12 C熔合反应触发的超级X-射线暴天文观测结果，无法用现有的基于外推得到的 12 C+ 12 C熔合反应率解释，因此对极低库仑势垒能量下 12 C+ 12 C熔合反应截面进行测量成为了核天体物理研究的一个热点。然而，超级暴典型的 12 C+ 12 C熔合反应伽莫夫窗口为1.5±0.3 MeV，远低于熔合反应库仑势垒。这使得用直接测量方法对该能区内极低的熔合反应截面进行研究成为一个巨大的挑战。特洛伊木马方法实验（THM）是目前唯一能给出伽莫夫窗口内各出射道激发函数的带电粒子测量实验，然而其结果目前仍存在很大争议。本工作回顾了 12 C+ 12 C熔合反应直接测量实验的研究现状，并对THM的数据分析结果提出了新的解读。结合全同玻色子体系理论对THM提取的复合核 24 Mg激发态进行讨论，首次给出 12 C+ 12 C熔合反应入射道无量纲约化宽度推荐平均值θ 2 =0.031，与反对称分子动力学模型（AMD）在相应能区的理论预言相一致。
The heavy quarks present in the quark-gluon plasma(QGP)can act as a probe of relativistic heavy ion collisions as they retain the memory of their interaction history.In a previous study,a stochastic Schrödinger equa-tion(SSE)has been applied to describe the evolution of heavy quarks,where an external field with random phases is used to simulate the thermal medium.In this work,we study the connection between the SSE and the Boltzmann transport equation(BE)approach in the Keldysh Green's function formalism.By comparing the Green's function of the heavy quark from the SSE and the Keldysh Green's functions leading to the Boltzmann equation,we demon-strate that the SSE is consistent with the Boltzmann equation in the weak coupling limit.We subsequently confirm their consistency through numerical calculations.
The validity of the isobaric multiplet mass equation(IMME)is of foundamental importance due to the ba-sic concept of isospin.Recently,a serious breakdown was found in the A=54,T=3 isospin septet,the largest isospin system where the validity of IMME have been tested up to now.Inspired by this work,I revist the mass of some isobaric analogue states with the help of recent results from advanced mass measurement experiment.It is found that the IMME holds well in A=50 and 46 isospin septet and the coefficients of IMME also follow the sys-tematic trends.Mass excess value for 50Ni and 46Fe,is predicted to be-3932(20)keV and 898(67)keV,respectively.
离子束放射治疗(放疗)越来越广泛地被运用于肿瘤治疗。目前使用传统X射线计算机断层扫描(CT)来制定离子放疗治疗计划时存在相对阻止本领(RSP)具有较大误差的问题，理想的方式是直接使用高能离子束对患者成像，生成离子放疗治疗计划设计时所需的医学图像，避免RSP转换从而减小RSP的误差。本研究使用蒙特卡罗程序Geant4/Gate搭建了离子CT模拟平台，设计了理想与现实两种离子CT成像系统探测器，利用最大似然法和ASD-POCS算法实现了图像重建，研究了理想与现实两种设置、多种能量以及不同离子种类对模体内硫、磷、碳和钙四种材料插件重建RSP误差的影响。结果表明，330 MeV质子在理想与现实设置两种情况下的RSP相对误差都小于1.547%，理想设置下的RSP相对误差远小于现实设置，现实设置下各材料的RSP重建误差接近理想设置下的3倍；质子的RSP相对误差随着能量的增加而减小，在230 MeV时的RSP相对误差最大，在硫、磷、碳、钙四种材料中分别为2.855%、2.468%、1.653%、2.553%。在330 MeV时的RSP相对误差达到最小，在硫、磷、碳、钙四种材料中分别为0.181%、0.351%、0.250%、0.245%；在能量330 MeV/u下，碳离子在硫、磷、碳、钙四种材料中的RSP相对误差分别为0.060%、0.281%、0.150%、0.082%，误差均在0.281%以内，RSP相对误差小于330 MeV的质子。因此，与质子CT相比，碳离子CT应能为离子放疗治疗计划设计提供更为精确的RSP数据。
未知放射源搜寻定位是核安检、核应急领域的重要研究课题。为提高寻源效率、适应多源环境探测,提出了一种融合到达角(AOA)的粒子滤波寻源方法。首先,构建了自主定位与AOA感知相结合的硬件平台,在搜寻过程中给探测器引入了位置和角度信息;其次,在粒子滤波基础上考虑AOA信息,动态收缩放射源搜寻区域,进而提高搜寻效率;最后,在自主寻源路径规划中采用AOA引导的机器人姿态调整,增强机器人寻源的灵活度。实验证明此方法可正确有效工作,放射源校验测试证明该方法也适用于多源搜寻。
我国载人航天和核技术应用正处于快速发展阶段,辐射与核安全仍将长期成为国家重大需求,持续开发新的辐射防护分子靶标和相关药物具有重要价值。先前的研究已发现电离辐射暴露后小鼠血液中的胰岛素样生长因子结合蛋白3(IGFBP-3)的水平显著上升,但是,IGFBP-3蛋白的功能及其血液水平的变化对小鼠辐射损伤的影响仍不清楚。本研究在小鼠肝脏巨噬细胞(Kupffer细胞,MKC)中建立了Igfbp3基因过表达和敲低细胞模型,利用CCK-8、EdU掺入、克隆形成和微球吞噬实验对碳离子照射后不同细胞模型的增殖活力、DNA复制活性和吞噬能力进行检测;在小鼠模型中,通过在照射前2h尾静脉注射重组IGFBP-3蛋白提前升高血液IGFBP-3蛋白水平,检测致死剂量(5 Gy)碳离子全身照射后小鼠的生存曲线。结果显示,过表达IGFBP-3蛋白显著提高了MKC细胞在辐射暴露后的DNA复制活性、细胞活力、克隆形成率和对微球的吞噬能力,相反地,敲低IGFBP-3蛋白表达则降低了以上检测指标。碳离子辐射暴露前尾静脉注射IGFBP-3蛋白可以显著延缓急性放射损伤小鼠的死亡时间。以上结果从细胞和动物水平表明了IGFBP-3蛋白具有减轻辐射损伤的作用和作为辐射防护药靶的巨大潜力。通过增强小鼠体内Kupffer细胞的辐射抗性和吞噬能力来降低辐射暴露后的感染风险可能是IGFBP-3蛋白发挥辐射防护作用的机制之一。
利用反应显微成像谱仪,采用二重符合方法,实验测量了0.64 keV/u N + 与He单电子俘获产生的反冲离子He + 三维动量,获得了电子俘获到炮弹离子不同量子态的态选择截面和角分布。实验结果表明:基态的炮弹离子N + （1s 2 2s 2 2p 2 ～3P）俘获He靶的一个1s电子主要布居到2p壳层,也可以看到布居到更高壳层的贡献;亚稳态的炮弹离子N + （1s 2 2s2p 3 ～5S）俘获He靶的一个1s电子主要布居到2s壳层,几乎看不到布居到更高壳层的贡献。利用NHe + 准分子离子的势能曲线定性地解释了实验结果,但分子库仑过垒模型的反应窗预测与实验存在较大差别。在亚稳态炮弹离子N + （1s 2 2s2p 3 ～5S）俘获靶电子到2s轨道的过程中,角微分截面出现了明显的振荡结构,这很可能来自Demkov型跃迁。
随着国内半导体企业技术的发展,部分国产元器件性能指标已经与进口元器件相当,能够满足核辐射监测仪器仪表的性能需求。基于1.5英寸LaBr 3 闪烁体设计了一套全国产化的γ能谱仪,包括闪烁体、光电倍增管和电子元器件均选用国产厂家产品。经测试,能谱仪在常温下的分辨率可以达到2.8%@662 keV。工作温度范围可达-40℃至50℃,且全温度范围内的能量分辨率均优于3.0%, 137 Cs全能峰道址随温度变化率约为-0.67/℃,且线性度良好。高压调整率为0.02 V,满足0.2 V/℃的稳谱高压调整率要求。谱仪的能量非线性好于99.99%。实验数据显示,现阶段国产LaBr 3 闪烁体、光电倍增管及电子元器件能够满足γ能谱仪的设计需求。
气体探测器中工作气体的平均电离能、法诺因子及漂移速度等参数对于探测器的前期模拟及设计乃至径迹重建有着重要影响。SeF 6 作为国内无中微子双贝塔衰变实验中的目标工作气体，相关参数未知需要探究。为研究该气体相关参数设计了一套测量方案，并采用Ar+10%CH 4 （P10）工作气体对该实验方案的测量精度和可靠性进行检验。实验中通过屏栅电离室测量α源得出P10平均电离能为27.46±0.05 eV；当能量分辨率达到0.91%时，刻度电子学后扣除噪声得到法诺因子为0.181±0.001。同时采用266 nm激光和时间投影室完成漂移速度的测量，其结果与Garifield++模拟结果吻合。实验结果表明，该测量方案可行，测量结果可靠性高。为后续开展SeF 6 性质的研究工作做好了准备。
The second 0+excited state at 7.65 MeV in 12C,known as the Hoyle state,is located near the 3-α break-up threshold and possesses a typical BEC-analog structure.This observation has triggered the intensive theoretical studies of the condensation configuration in nuclear systems,typically represented by the THSR wave function.In the mean time,the experimental investigation of the Hoyle-like states in heavier nuclei has been advanced quite slowly,due mostly to the difficulties in detecting multi-fragments in coincidence and the clarification of the reaction-decay mechanisms.We give here a review of the theoretical and experimental progresses in this field by taking into account the latest experimental outcomes for the 4-α resonance in 16O and α+2n+2n resonance in 8He.Some per-spectives are also given towards the possible BEC-like states in neutron-rich systems,which would be of particular importance in exploring the properties of the heavier neutron-rich nuclei and also the neutron stars.
为提高空间堆中子学模拟的可靠性,基于国际临界安全手册中关于空间堆的临界基准实验（HMF005基准实验）,采用蒙特卡罗程序对HMF005基准实验中堆芯排布进行建模,结合不同评价核数据库,计算6种堆芯排布下的K eff 计算值与实验值的偏差,并对计算值与实验值的比值的平均值、标准偏差、χ 2 和均方根误差等进行深入分析。研究发现,ENDF/B-Ⅶ.1、CENDL-3.2、ENDF/B-Ⅷ.0和JEFF-3.3四种评价核数据库计算堆芯K eff 结果与实验值偏差处于3倍不确定度之内,其中ENDF/B-Ⅶ.1计算结果最接近实验值,CENDL-3.2与实验偏差稍大。CENDL-3.2库计算结果与实验值偏差稍大主要是由于评价库中的钼和铍核素导致,钼的同位素中 92 Mo的影响最大。同时还进行敏感性分析, 92 Mo和 9 Be的总反应敏感性系数主要跟弹性散射敏感性系数相关,CENDL-3.2和ENDF/B-Ⅶ.1中的 9 Be辐射俘获敏感性系数差异较大,两者的偏差可达34.9%。
聚变三乘积（Fusiontriple product）是可自持核聚变反应的重要判据,它利用聚变堆中核燃料的原子核数密度n、等离子体能量约束时间τ E 、燃料温度T这三个物理量来判断聚变反应堆是否能满足实现自持核聚变的能量平衡条件。本研究探讨了以 6 Li-D作为核燃料的聚变反应系统,并考虑了相对论效应对轫致辐射的影响以及能量回收效率对能量增益因子Q的影响,计算了忽略回旋辐射条件下 6 Li-D聚变反应系统产生Q=1的能量增益时的聚变三乘积(n i Tτ E =4.9×10 23 m -3 ·keV·s)。结果表明, 6 Li-D可以作为核聚变燃料实现正的能量增益,但其实现自持核聚变的点火条件相对于D-T核聚变的点火条件来说更为困难。
低能高电荷态离子与H原子电荷交换X射线的实验和理论研究为天体环境中非平衡态等离子体的诊断和建模提供了重要原子数据。本工作利用半经典多通道Landau-Zener（MCLZ）方法计算了全裸和类氢的C、N、O离子与H原子电荷交换截面并与已报道实验结果进行了比较。我们发现，对于C 5+ +H碰撞体系，理论计算的总截面和实验测量相差较大。同时，也对比了太阳风离子速度（或能量）区间MCLZ方法和全量子分子轨道紧耦合（QMOCC）方法计算的态选择截面。发现，对于俘获到n=3壳层，MCLZ方法计算的态选择截面随碰撞能量升高而增加；对于俘获到n=4壳层，MCLZ方法计算的态选择截面随碰撞能量升高而减小；在低能端比QMOCC方法计算的截面小两个量级之多。最后，采用天文领域发展的Kronos程序包，通过Janev推荐的截面数据[Atomic Data and Nuclear Data Tables, 1999, 55（2）:201]计算了1 keV·u -1 O 8+ +H电荷交换X射线谱、线强比及硬度比，并与MCLZ计算结果比较。我们认为，MCLZ计算方法结合l分布模型具有较大的不确定性，会影响天体环境建模的准确性。亟需发展更加准确的全量子理论。
