通过分析（p,n）电荷交换反应的微分散射截面数据，得到了核子光学势实部的同位旋矢量项。（p,n）反应的微分散射截面的大小正比于核子光学势实部的同位旋矢量项v1的平方，利用平面波玻恩近似可以直接提取v1的值。再根据HVH理论，利用v1的值能够得到对称能Esym(ρ0)和它的密度依赖斜率L(ρ0)的值。得到的结果Esym(ρ0)=28.5 MeV, L(ρ0)=76.0 MeV与分析原子核质量和其他核实验数据得到的结果符合较好。

The isovector term of the real part of the nucleon optical potential is obtained by analysing differential cross section data of (p,n) charge exchange reaction. The magnitude of the differential cross section of (p,n) experiment is proportional to the square of the isovector term of the real part of the nucleon optical potential v1, so the extraction of the value of v1 is straightforward by using the plane wave Born approximation. Based on the Hugenholtz-Van Hove theorem, the nuclear symmetry energy Esym(ρ0) and its density slope L(ρ0) are estimated by using the extracted value of v1. The calculated results Esym(ρ0)=(28.5±2.0) MeV, L(ρ0)=(67.0±5.0) MeV agree reasonably with those extracted by analysing nuclear masses and other experimental data.

利用同位旋相关的量子分子动力学模型模拟了 4He + 208 Pb的碰撞反应，发现中子质子产额比与 208 Pb的中子皮之间存在很好的线性关联，中子质子产额比可以作为中子皮厚度测量的一个探针。选取量子分子动力学模型中核物质状态方程的两套不同势参数进行模拟，通过对比发现，中子皮的厚度测量探针中子质子产额比对核物质状态方程中选择软势和硬势非常敏感，相同反应条件下，软势比硬势计算所得的中子质子产额比要低。无论选择何种状态方程参数，中子质子产额比与中子皮之间都存在线性关联。

The reaction system of 4He + 208Pb has been simulated by Isospin-dependent Quantum Molecu-lar Dynamics (IQMD) mode and it was found that the neutron-to-proton yield ratio (Rnp) has a good linearrelationship with the neutron skin thickness of 208Pb. Therefore Rnp could be taken as a probe of neutron skin thickness of 208Pb. Using two sets of parameters for the nuclear equation of state (EOS) in IQMD model, it shows that Rnp is sensitive to nuclear equation of state. The calculation results of Rnp with the soft EOS is lower than the hard EOS. No matter which kind of EOS parameter has been chosen, however, Rnp holds a good linear correlation with the neutron skin thickness.

利用标度阶乘矩方法对290 A MeV $^{12}$C-AgBr, 400 A MeV $^{12}$C-AgBr, 400 A MeV $^{20}$Ne-AgBr及500 A MeV $^{56}$Fe-AgBr 作用靶核反冲质子在二维正常相空间及累积变量空间发射过程中的多重数涨落分别进行了分析。实验结果表明：在正常相空间，对于秩数q较小时标度阶乘矩（$ln

$）随相空间的分割数的增加而增加，而对于秩数较大时标度阶乘矩（$ln

$）随相空间的分割数的增加表现出先增加后趋于饱和或减小的趋势；在累积变量空间，标度阶乘矩（$ln

$）随相空间的分割数的增加而减小，这表明对于我们所研究的核作用体系靶核反冲质子发射过程中不存在非统计涨落。

Multiplicity fluctuation of the target recoil protons emitted in $290$\,A MeV $^{12}$C-AgBr, $400$\,A MeV $^{12}$C-AgBr, $400$\,A MeV $^{20}$Ne-AgBr and $500$\,A MeV $^{56}$Fe-AgBr interactions are studied using the scaled factorial moment (SFM) method in two-dimensional normal phase space and cumulative variable space, respectively. It is found that in normal phase space the SFM ($\ln

$) increases linearly with the increase of the divided number of phase space ($\ln{M}$) for lower q-values and increases linearly and then becomes saturation or decrease with the increase of $\ln{M}$ for higher q-values, and in cumulative variable space $\ln

$ decreases linearly with the increase of $\ln{M}$, which indicates that no evidence of non-statistical multiplicity fluctuation is observed in our data sets.

重离子碰撞产生的高温高密度物质假设按照统一流体力学模型的规律做时空演化，并最终经由一固有时为Tau_FO的类时超曲面冻析为带电粒子。统一流体力学模型是一种将Landau与Hwa-Bjorken两著名流体力学模型结合在一起的模型，是一种少有的可精确求解的理论之一。本文的研究表明：BNL-RHIC低能量区重离子碰撞中带电粒子的赝快度分布可由统一流体力学模型很好地描述。 这与高能区的情况不同，在那里，除了流体外，还需考虑带头粒子的贡献。

The hot and dense matter created in heavy ion collisions is supposed to have spatiotemporal evolution according to unified hydro model, and finally freeze out into the charged particles via a space-like hypersurface with a proper time Tau_FO . The unified hydro model is a model which integrates Landau and Hwa-Bjorken two famous hydro models together. It is one of few hydro models which can solved exactly. Shown from the investigations in this paper, the pseudorapidity distribution of charged particles in heavy ion collisions at low BNL-RHIC energy region can be well described by unified hydro model. This is different from that at high nergy region, where, apart from fluid, the contribution from leading particles should be taken into account.

在色玻璃凝聚胶子饱和框架下，研究了相对论重离子碰撞中的双轻子和光子产生。在胶子饱和区域，在微扰近似(kT-因子化近似) 下低转移动量双轻子和光子的主要产生机制是胶子-胶子相互作用。在RHIC 和LHC 能量区域的相对论重离子碰撞中，饱和动量的值远远大于量子色动力学禁闭标度ΛQCD，这使得αs≪1。此时，当转移动量小于饱和动量Qs 时质子和原子核的胶子密度值就会很高，双轻子和光子的不变产生横截面会由于饱效应而得到增强。数值结果给出在RHIC 和LHC 能量区域的pp, pA 和AA碰撞中，来源于色玻璃凝聚的低转移动量双轻子和光子产生贡献是显著的。

We investigate inclusive dileptons and photons production in relativistic heavy ion collisions based on the idea of gluon saturation in the color glass condensate (CGC) framework. In the gluon saturation region, the dominant mechanism for low-pT dileptons and photons production in the perturbative approach (the kT-factorization approach) is gluon-gluon interaction. At Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies, the value of saturation momentum becomes larger than the Quantum Chromodynamics (QCD) confinement scale ΛQCD for relativistic heavy ion collisions, which implies that αs≪1. In this state, the gluon density for proton and nucleus with transverse momentum less than the saturation momentum Qs will reach a high value, and the invariant cross-section for dileptons and direct photons is further enhanced by saturation effects. The numerical results indicate that the production of low-pT dileptons and photons from the color glass condensate becomes prominent in pp, pA, and AA collisions at RHIC and LHC  Energies.

对于低能强流离子束来说，空间电荷效应的存在将导致束流发散、发射度增加等一系列问题，从而降低束流品质。幸运的是，当束流由离子源引出通过低能传输线时会与其中的剩余气体发生电离反应，产生二次电子与二次离子；二次电子在束流自身产生的电场作用下，在束流中积累并中和部分空间电荷，达到抑制空间电荷效应的效果。为了测量空间电荷中和程度，中国科学院近代物理研究所研制了一台三栅网式能量分析仪用以测量电离过程中产生的二次离子能量来间接计算空间电荷中和度。实验结果表明，对于40 keV, 18.5 mA的质子束，真空度为1.510*3 Pa 时得到最佳补偿度；真空度一定的情况下，空间电荷补偿度随束流流强增加而变大。

For high-intensity low-energy ion beams, space charge effect is a main cause of beam divergence  and emittance growth. Fortunately, residual gas molecules in the drift space tend to be ionized and neutralize the beam space charge spontaneously. The level of Space Charge Neutralization (SCN)
is measured through the detection of created secondary ion energy distribution in the beam region. A so-called non-interceptive Three-grid Energy Analyzer (TEA) has been designed and manufactured at Institute of Modern Physics, Chinese Academy of Sciences (IMP). This paper will present the details
of the TEA detector and the application to diagnose proton beam SCN level in the Low Energy Beam Transport (LEBT) line. As a preliminary result, for an 18.5 mA proton beam a best compensating point appears at the vacuum pressure of 1.510*3 Pa. And the neutralization level is advanced with the
growth of beam current in a constant vacuum pressure.

SFC（扇聚焦回旋加速器）是兰州重离子加速器HIRFL重要组成部分，其束流引出效率直接关系到整个加速器的运行效率。原SFC引出静电偏转板运动控制系统由于其设备陈旧，控制方式及控制精度都已不能满足调束的需求，加之位置检测功能的缺失，给调束带来极大不方便。基于此状态，本项目在有限的检修时间内，分两期实现了偏转板的位置检测和运动控制功能。在设计过程中，使用实际位置拟合测量数据的方法，提高了位置检测的精度，特别是用了特定的软件补偿算法消除机械传动回程差，大大提高了电机控制精度，目前整体控制精度在0.2mm左右。用户界面能够显示每个电机的相对位置、模拟动画、限位开关状态指示等信息。界面简洁直观，操作方便。系统自2014年夏季运行以来，稳定可靠，提高了供束效率，减少了故障时间，得到调束人员一致好评。

SFC (Sector Focusing Cyclotron) is an important part of the Heavy Ion Research Facility in Lanzhou.The beam extraction efficiency of SFC is directly related to the efficiency of the whole accelerator. Because of the old equipment and control mode, as well as the low control accuracy of the SFC electrostatic deflection plate motor control, the motion control system was not able to meet the demand of beam tuning staff. In addition, there were no position detection function for this deflection plate; the beam tuning staff cannot get the current position of the deflection plate when they move these motors. Based on this situation, we designed and realized SFC motor control and position detection system in the summer maintain period in 2014 and 2015. In the design, we used the actual position to fit the measured voltage signal to improve the accuracy of position detection. Meanwhile, a specific compensation algorithm was designed to eliminate the mechanical transmission return difference, which greatly improved the motor control accuracy. At present, the overall control accuracy is about 0.2 mm. The user interface has numbers to shows the relative position of each motor and related animation, indicator led to show the status of each limit switches, easy operate buttons to control the motor moving. The system has been running stably and reliably since 2014. It has improved the efficiency of the beam tuning and reduced the fault time, so it is well praised by the beam tuning staff.

紫外脉冲荧光法是一种通过液体激光来直接测定微量铀的方法。在采用紫外脉冲荧光法分析面包酵母吸附放射性核素铀后溶液剩余铀浓度之前，研究了荧光增强剂、pH 值、以及温度对微量铀浓度工作曲线的影响。结果表明：当pH > 3时，400 μL 荧光增强剂可以充分缓冲溶液，不同pH 值下测得的荧光计数基本保持恒定，即待测溶液pH值不会影响铀浓度的测量；随着温度的升高，荧光计数近似线性下降，并在室温23.6℃时得到了铀质量浓度范围为0:120 μg/L 的工作曲线。在此基础上研究了酵母菌对放射性核素铀的吸附作用，为使吸附剂达到最高效利用，对溶液pH 值、吸附速率进行了批次实验，并通过紫外脉冲荧光分析法进行测量, 发现达到吸附平衡所需的最短时间为180 min，吸附的最佳溶液pH 值为5.8 左右。

The method of pulse ultraviolet fluorescence was employed to analyze the concentration of radioactive nuclide uranium after adsorbed by baker’s yeast. Influences of fluorescent enhance reagent, pH value, and temperature on measurement of the concentration of trace uranium were investigated. The results showed that 400 μL fluorescent enhance reagent was greatly enough to buffer the solution when pH > 3 and the counts of fluorescence kept constant with the variation of pH, which indicates that the pH of solutions doesn’t affect the determination of uranium concentration, moreover, the counts of fluorescence declined linearly as the increase of the temperature. In addition, the working curve of the determination of uranium concentration within 0.1 20 μg/L was obtained when the temperature was 23.6 ℃. On this basis, the adsorption of uranium by baker’s yeast was studied. For the adsorption of radioactive nuclides of uranium by baker’s yeast to achieve the best use, the batch experiments were carried out on the rate of adsorption and pH of solutions. The method of pulse ultraviolet fluorescence was used to measure and found that the minimum time required to reach adsorption equilibrium was 180 min and the optimum pH value of solutions was about 5.8.

靶单元组件对中子有散射和吸收作用，与入射粒子也会发生反应，因此高压倍加器中子场在空间的分布除了由反应本身的角分布决定外，还受到靶单元组件的影响。实验利用飞行时间法测量了高压倍加器T(d,n)4He 中子源产生的实际中子场，测量角度为0°~95°，共8 个角度，采用伴随 粒子法对入射束流进行归一。借助蒙特卡罗方法模拟实验过程和靶单元组件等对中子场分布的影响，将实验结果同模拟计算得到的结果进行了比较与分析，为高压倍加器相关实验布局的合理布置和靶单元组件的优化提供了一定的依据。

The spatial distribution of neutron field for the High Voltage Multiple Accelerator (HVMA) is not only determined by the angular distribution of the reaction itself, but also affected by scattering and absorption of the target unit. Meanwhile, undesired nuclear reactions of the incoming ions with the target and self-target build-up may contribute to this neutron background, which disturbs the primary neutron field. The spatial distribution of actual neutron field generated by T(d, n)4He on HVMA was measured using the flight-time method. The neutron emission energy spectra were measured at 8 different angles from 0° to 95°. The results were monitored by the accompanying-particle method. TARGET and MCNP (Monte Carlo simulation process) programs were used to simulate the experiment. The results of simulated calculation were compared with the experimental data. The analyzed results will give some qualitative and quantitative conclusions for target unit optimizing and provide some foundational works for physical measurement in HVMA.

为了提高PGNAA系统中D-T中子管的中子慢化效率，获得更高的热中子产额，借助蒙特卡罗模拟，确定了以铅为中子反射层、5个聚乙烯层和铅层相互交替作为中子慢化层、碳化硼含量为3%的含硼聚乙烯作为中子吸收层以及铅作为γ屏蔽层的中子慢化装置模型。针对中子产额为3×107 n/s 的D-T中子管，该慢化装置输出面低于5 eV中子通量可达5.28×106 n/s，占总中子通量的30.8%，有效提高了中子慢化效率。经过验证模拟结果能够满足实验要求。

To improve the moderating efficiency of D-T Neutron Generator in PGNAA system, and get higher thermal neutron yield, the Monte Carlo code MCNP was used to optimize the moderation setup. The lead was selected as neutron reflector and gamma absorber, 5 polyethylene layers and 4 lead layers constituted the neutron moderator and 3% boron-doping polyethylene was selected as neutron absorber. For the yield of 3107 n/s D-T Neutron Generator, this moderation setup can provide a yield of lower than 5 eV of 5.28106 n/s, accounting for 30.8% of total neutron yield, dramatically improves the moderating efficiency. It is proved that the simulation results can satisfy the requirement of PGNAA system by preliminary experimental verification.

作为一种载能粒子，高能电子束具有能量利用率高、贯穿深度大、方便实用等优点，可以用来杀灭细菌和抑制病原体生长，因而被广泛应用于食品保质储藏和医疗卫生等方面。但是，对于高能电子如何与生物及其生物分子发生作用，以及作用的过程、方式、效果和机理等方面，人们还缺乏深入、细致的了解。本研究利用高能电子束辐照模式蛋白酶辣根过氧化物酶(HRP：horseradish peroxidase)，研究了电子束对它的损伤作用和机理。研究发现，电子束损伤HRP 的方式主要通过羟基自由基破坏蛋白质肽链，同时，辐照产生的活性氧物质也会作用于HRP 分子活性中心引起其辅基血红素的损伤。这与我们以前研究的等离子体放电辐照HRP其损伤主要通过H2O2 作用于变性蛋白血红素引起酶失活有所不同。进一步，通过利用活性氧和自由基清除剂的方法，具体分析和阐明了电子束辐射条件下同活性氧和自由基在损伤HRP 过程中所起的破坏作用。

As one kind of charged energetic particles, high-energy electron-beam (e-beam) can kill bacteria effectively; and because of its advantages of low-cost and high-efficiency, e-beam has been widely applied in food sterilization and storage industry as well as biomedical areas. However, currently we still lack the in-depth understanding of the mechanism of the interactions between high-energy particles and biological systems. To this end, we thus initiated the study of e-beam induced damage of horseradish peroxidase (HRP: horseradish peroxidase). Our results revealed that the e-beam induced damage of HRP was mainly through the hydroxyl radical attack on the polypeptide chains, and at the same time, the heme active site of HRP was also injured by the reactive oxygen species (ROS) produced by the electron-beam. This hydroxyl radical damage mechanism is different from the hydrogen peroxide damage mechanism that plays the dominant role in non-thermal plasma treatment as we reported previously. Moreover, by using the ROS and free radical scavengers, we analyzed and identified the major factors that contributed to the HRP damages.

斑马鱼胚胎最初为研究发育生物学与分子遗传学的重要模式动物，20 世纪90 年代关于斑马鱼胚胎研究的文章每年不足100 篇，到本世纪初期已上升到每年1 000 余篇，目前这个数字正呈指数增长，斑马鱼胚胎的研究范围与应用价值正也随之逐步提升。该文综述了斑马鱼胚胎在电离辐射研究领域中的应用，包括电离辐射诱导斑马鱼的毒性作用、电离辐射引起的DNA损伤及其信号转导机制，以及利用斑马鱼对辐射防护剂与增敏剂进行评价。在此基础上还特别介绍了中国科学院近代物理研究所利用斑马鱼胚胎在放射生物学研究上取得的进展，其中包括一种具有物理激发、化学刺激作用的线粒体内活性氧(ROS) 诱导剂，在非条件刺激下利用斑马鱼检测该物质的毒性，发现6 10 μL/mL 的该物质无胚胎发育毒性，然而，在一定波长的光刺激下可造成DNA双链断裂，在理论上是一种潜在的辐射增敏剂。

Zebrafish embryo is a classic animal model to study developmental and molecular biology. The relatedworks using zebrafish embryo arise from less than 100 papers per year in 90 s to more than 1 000 papers per year at the beginning of 21st century. The research scope and application value of zebrafish embryo in biology studies are gradually extending, along with the exponential increase of related papers. Here, the applications of zebrafish embryo in the field of radiation biology are reviewed, including radiation-induced toxicity, signal transduction in response to radiation-induced DNA damage, and the assessment of radio-protection and radiosensitizers, respectively. The progress in radiation biology employing zebrafish embryo in Institute of Modern Physics has also been reported, includinga novel mitochondrial reactive oxygen species inducer, which can be triggered by exogenous physical signal and exert chemical stimulation. This inducer shows no obvious embryo toxicity to zebrafish under 10 μL/mL. It can induce DNA double strand breaks if activated by certain wavelength of lights. Itisa potential radiosensitizerin theory.

为了研究降雨对空气中短寿命氡子体的清洗机制，设计了分别模拟大气降雨的水汽凝结过程和雨粒下降过程的两个实验装置，并进行了多次实验，实验水样采用低本底 能谱仪进行测量。实验结果表明：凝结水的短寿命放射性计数与本底相近，说明水汽凝结不能俘获短寿命氡子体。某一次自来水冲刷空气后获得了高出本底30.9% 的初始 计数，其半衰期为35.7 min，纯净水冲刷空气后获得了高出本底19.6%的初始计数，这些计数主要是由氡子体214Pb 和214Bi 引起的。可见，无论是自来水还是纯净水，它们冲刷空气后都能俘获短寿命氡子体，且半衰期和放射性核素种类均与雨水相似。这一实验结果充分说明：大气降雨的短寿命放射性不是在水汽凝结阶段而是在降落阶段对空气的冲刷获得的，是在降落过程中俘获了空气中的短寿命氡子体214Pb 和214Bi 而引起的。本次实验结果为降雨对空气中短寿命氡子体的冲刷清洗机制提供了最有力的证据。

To investigate the underpinning mechanism of rainfall-scavenging of the atmospheric short-lived radon daughters, two experiments simulating water vapor condensing procedure and raindrop falling procedure were conducted. The radioactivity of the tested water was measured by low-background   γ spectrometry. The obtained results showed that the γ-ray counts of condensed water was on the same level as the background,which proved that water vapor condensation cannot trap short-lived radon daughters. In contrast, the initial γ-ray count of washout water (35.7 min half-life) was increased by 30.9% after washing the atmosphere with tap water. Similarly, the initial  -ray count of washout water was increased by 19.6% after washing the atmosphere with puri ed water. These counts originated mainly from radon daughters 214Pb and 214Bi. Obviously, both tap water and puri ed water can trap short-lived radon daughters when washing the atmosphere. Furthermore, the half-life and the kinds of radioactive nuclides in the washout water are similar to that in the rainfall water.These experimental results are able to ascertain that short-lived radon daughters in precipitation come mainly from scavenging (washout) and not from water vapor condensation within the cloud. It is in the process of falling that raindrops trapped short-lived radon daughters 214Pb and 214Bi. The obtained results as demonstrated here provide a powerful evidence for understanding the washout mechanism of short-lived radon daughters from the
atmosphere by rainfall.