2015年 第32卷 第4期
丰中子核91Y 的高自旋能级结构通过82Se(13C, p3n)91Y 反应被再次研究了。新建立的包含几条关键能级的能级纲图澄清了以前研究中的几点不确定的地方。这几条能级具有Z=38 和N=56 子闭壳打破的特征，这涉及到张量力和自旋-同位旋依赖的中心力。
High-spin level structure of the neutron-rich nucleus 91Y has been reinvestigated via the 82Se(13C, p3n)91Y reaction. A newly constructed level scheme including several key levels clarifies the uncertainties in the earlier studies. These levels are characterized by the breaking of the Z = 38 and N =56 subshell closures, which involves in tensor force and the spin-isospin dependent central force.
基于改进的包含同位旋相关项的Nilsson 势，使用投影壳模型，对镁同位素低激发谱所反映的四极关联特性进行了讨论。首先研究了单粒子能在反转岛附近的演化情况，集中比较了同位旋相关项的Nilsson 势及标准Nilsson 势的差异，指出同位旋相关项能够用来描述反转岛核素结构的原因。通过分析实验及计算得
Collective phenomenon in magnesium isotopes is an interesting topic. In order to optimize the description of magnesium isotopes located around the “island of inversion”, we use an isospin-dependent Nilsson potential to define the deformed basis for our projected shell model calculations. Single particle energies in nuclei around “island of inversion” are calculated and discussed, so as to clarify the effect of isospin-dependence.The low-lying spectra are further investigated, which reflect a clear behavior of quadrupole collectivity in the neutron-rich magnesium isotopes. Electric quadrupole transition properties are also studied. Configuration mixing mechanism of projected shell model has an important influence on these transition properties. From this
analysis, we also learn the signal of rotational behavior. Gyromagnetic factors of magnesium isotopes are also calculated. Different contributions from neutron configurations and proton configurations are given separately.
过渡区原子核的形变与准粒子占据的轨道密切相关。采用推转壳模型首次系统性地研究了奇A核99Pd、101Pd和103Pd原子核中h11/2轨道对核芯的形状驱动效应，基于Total-Routhian-Surface (TRS)方法的计算结果表明，当过渡区原子核99Pd、101Pd和103Pd中的准粒子开始占据h11/2入侵轨道时将会使原子核产生稳定的四极形变。另外，对A≈ 210 质量区近滴线核的高自旋态研究现状及今后进一步的工作也进行了概述。
The deformations of the nuclei in the transitional region are closely related to the orbitals occupied by the quasiparticles. The driving effects of the h11/2 intruder orbitals in 99Pd, 101Pd and 103Pd were studied in the framework of the cranked shell model. Based on the total-Routhian-surface (TRS) calculations, the h11/2 intruder orbitals might polarize the cores of 99Pd, 101Pd and 103Pd to a small, but rigid quadrupole deformation,and thus collective rotational motion would develop. The aspects for the research on the high spin states of near the drip-line nuclei in A≈ 210 region as well as our future research work are also briefly reviewed.
利用多源热模型分析了ATLAS实验组2.76 TeV 铅-铅碰撞中产生的、带电粒子在多个不同中心度事例中的方位角分布，并与n=2,4,6 和n=2 的傅里叶级数形式的方位角分布进行了比较。同时，利用由多源热模型得到的散射源在横动量空间的结构参数，计算了散射源在横动量空间的各向异性率和相对膨胀率，且与
We analyze the azimuthal distributions of charged particles produced in 2.76 TeV Pb-Pb collisionsfrom ATLAS experimental group in eight different centralities by using the multi-source thermal model. Themodeling results are compared with the results from Fourier series forms with n = 2,4,6 and n = 2. Meanwhile,the anisotropy ratios and the relative expansion rates of scattering source in transverse momentum space are calculated applying the transverse structural parameters of multi-source thermal model, and the modeling results are compared with the associated fourier coefficients. The anisotropy ratios and the relative expansion rates are less than the corresponding fourier coefficients in transverse momentum space in different center intervals. Elliptical anisotropy is main component in azimuthal distribution. Other anisotropies have different contributions in different centralities, and these contributions cannot be neglected.
近年来，高能物理界取得的最重要的成就之一是发现高能重离子碰撞产生的高温高密度物质极近理想流体。描述这种流体膨胀过程的最佳工具是相对论流体力学。本文在Hwa-Bjorken与Landau相对论流体力学统一描述理论的基础上，考虑到带头粒子的贡献，讨论了带电粒子的赝快度分布。由流体冻析产生的带电粒子的快度分布可由统一流体力学理论解析得到，带头粒子的快度分布假设具有高斯形式。与LHC-RHIC-PHOBOS合作组在能量分别为 =62.4 与130 GeV 的Au-Au碰撞中的实验测量相比较知：理论与实验结果符合得很好。
One of the most important achievements obtained in high energy physics in recent years is the discovery that the matter created in nucleus-nucleus collisions behaves like a nearly perfect fluid. The best tool for describing the expansions of this fluid is relativistic hydrodynamics. By taking into account the contributions of leading particles, this paper discusses the pseudorapidity distributions of charged particles on the basis of a theory of unified description of Hwa-Bjorken and Landau relativistic hydrodynamics. The rapidity distributions of charged particles frozen out from fluid can be obtained analytically from unified hydrodynamics. The rapidity distributions of leading particles are assumed having Gaussian form. Known from a comparison with experimental observations made by LHC-RHIC-PHOBOS Collaboration in Au-Au collisions at = 62.4 and 130 GeV, respectively, the theoretical results are in good accordance with experimental results.
利用3 个不同的初始手征角，给出了重子数为1 的体系的平均场方程的一次迭代后的解，以此研究哪一种手征角可以令平均场方程的解的自洽性更快地达到。对于不同的初始手征角，发现经过第一次迭代后，指数形式的手征角给出的结果比别的手征角更接近自洽解的形状。
We use three different initial chiral angle to give the solution of the mean-field equation of the system with baryon number B = 1 for the first iteration, to investigate which initial chiral angle will make the self-consistency reach faster. From the first iteration from different initial chiral angle, we found that the result from the inverse trigonometric form chiral angle is closer to the self-consistent one than the other two initial chiral angles.
作为直线加速器的前级聚焦加速部分，RFQ(射频四极场) 在束流动力学和运行稳定性上都应表现良好，需要保持电场平整和电磁强耦合。为实现这两个目标，提出并研究了窗耦合结构。针对工作频率为81.25 MHz 的1 m长模型腔，利用三维电磁仿真软件CST MWS微波工作室对传统的四翼型、四杆型高频结构进行了仿真，并重点研究了窗耦合型结构。对开窗的对称方式、开窗的个数和大小等进行了分析，发现合适的窗耦合结构能保持较为紧凑的横向尺寸同时能耗适中，同四翼型结构相比二极模频率也远离了运行频率。为验证模拟结果，建造了一个铝模型腔，并对模型腔进行了冷模测试，实测频率为81.41 MHz，相邻模频率差为10.74 MHz，与模拟结果接近。仿真模拟和模型腔测试的结果表明，窗耦合四翼型结构可作为较低频率RFQ的一种设计。
As a focusing and acceleration element in front part of the linear accelerator RFQ, should have ahigh performance in both beam dynamic and operation stability. It requires the electro-magnetic field of RFQ to keep uniform and strongly coupled. In this paper the window coupled structure is proposed and investigated to meet the requirements of RFQ design. Different structures have been compared and analyzed, including four-vane type and four-rod type, and the four-vane type with windows. It was concluded that window-coupled structure is more compact in the transverse dimension with modest power loss and the dipole frequency is far from the operation frequency compare to the normal four-vane structure. A one-meter long and frequency of 81.25 MHz model-cavity of alumimum was employed as a sample and simulated by using the microwave studio of CST. The low power RF test results show that the operating frequecy is 81.41 MHz and the nearest mode frequency separation is 10.74 MHz, which is in good agreement with the simulated values. It is concluded that the window-coupled structure is a candidate for low frequency RFQ.
现代智能优化算法粒子群算法\,(Particle Swarm Optimization)\,在加速器设计优化上的应用逐渐增多。交变相位聚焦直线加速器\,(Alternative Phase Focused Drift Tube Linac)\,具有节省空间和造价的优点。将交变相位聚焦直线加速器的初步设计方案作为种子，植入粒子群算法中；以加速器的传输效率和束流能量作为目标，得到该方案的Pareto最优解集；在粒子进化过程中，以前沿解集作为粒子的运动方向，以前沿解集的束流径迹作为粒子的参数来源。最终得到了满足能量增益的高传输效率、大接受度的优化方案。
The Particle Swarm Optimization(PSO), one of the modern intelligent optimization algorithms,is increasingly employed in the design and optimization of accelerators. Alternative Phase Focused Drift Tube Linac(APF DTL) has an advantage in cost-effecient fabrication and reduced construction space. The preliminary design of APF DTL is involved in the optimization as the anchor; by taking the acceleration efficiency and the beam energy as two fitness functions, the Pareto optimal set is obtained; the evolutionary direction is determined by the Pareto optimal set and the particles’ parameters in the optimization are derived from the simulations of the randomly selected Pareto optimal solutions. A final optimized design with extracted energy of 5.35 MeV/u
and acceleration efficiency greater than 83% is acquired.
以HIAF-CRing上典型离子238U34+为研究对象，对其纵向俘获和加速的动力学过程进行了研究。累积后的粒子能量为800 MeV/u, 经过绝热俘获和加速后，粒子被加速至1 130 MeV/u。研究结果表明，通过选择适当的俘获时间、绝热参数以及相空间面积因子等参数，应用优化后的高频俘获加速曲线，可以获得更高的俘获和加速效率。通过粒子纵向动力学追踪软件ESME 上进行模拟，得到了优化后的高频相位、高频电压曲线，使得俘获效率达到99.3%，加速效率近乎100%。同时确定出了CRing 高频腔加速U34+ 所需满足的特性参数，即电压需达到40 kV，频率范围是0:31s0:34 MHz。
To reduce the beam loss during the capture and acceleration processes of CRing in HIAF project, the longitudinal beam motion is investigated using the typical ion of 238U34+during the two processes mentioned above. The ions will be captured adiabatically firstly and then will be accelerated from 800 to 1130 MeV/u with a high efficiency using optimized RF voltage and RF phase program. After that the bunched beam will be debunched for the later beam compression. Simulation of these processes by tracking appropriate distributions with the longitudinal beam dynamics code ESME has been used to
find optimum parameters such as RF phase, RF voltage. The variation of the parameter during the RF cycle and the character parameters of the RF cavity are presented.
介绍了基于MSP430F169 混合数字信号处理器和EPM1270T144C5N 复杂可编程逻辑器件(CPLD) 而设计的综合报警平台系统。MSP430F169 混合信号处理器具有超低功耗、处理能力强、系统工作稳定等优点。EPM1270T144C5N 是一种具有144 只管脚的复杂可编程逻辑数字器件，可以实现同时对多个不同的设备报警信息采集与处理。该综合报警平台对HIRFL-CSR 上运行的各个分散的监测报警系统所产生的报警信息进行综合收集处理与报警，主要是先根据现有已上传到监测报警系统服务器中的原始数据进行条件判断，服务器根据判断结果发送相应的指令，MSP430 利用UART功能和网络协议转换器配合接收；然后MSP430
把接收到的指令数据解析后送到CPLD 数据端口，由CPLD 控制连接的报警器，实现报警功能；也可利用CPLD 多管脚的优势，控制其他的现场设备。MSP430F169 内部的12 位ADC和DAC 模块可实现对现场设备的模拟信号的给定和回读。系统客户端的软件采用Microsoft Visual C++ 6.0 设计。该综合报警平台具有结构简单、响应速度快、稳定性好等优点，可实现单板对多种不同设备的控制与监测。
A system of a comprehensive alarming platform based on MSP430F169 (a mixed signal microcontroller) and EPM1270T144C5N(a complex programmable logic device -CPLD) has been introduced in this paper. The system has the advantages of ultra-low power consumption, powerful processing ability and operating stably by using the MSP430F169. Meanwhile the EPM1270T144C5N is one of the complex programmable logic device which has 144 pins, and it was controlled by MSP430 to output or input the digital signals. The control system is charge for responding the alarming information from the scattered monitoring system which has running on the HIRFL-CSR. The duty of this system is to receive the commands which have been analyzed by server. The
12-bit ADC and DAC module in the MSP430F169 can also read back the voltage of device or set the voltage to the specific device. The system’s client software is designed in the Microsoft Visual C++ 6.0 environment. The system has the advantage of a simple structure, fast response, good stability, and is able to monitor different running systems and devices in real time on one board.
在中国原子能科学研究院HI-13 串列加速器上的非常规多探测器快中子飞行时间谱仪上，采用直接中子法测量了14.3 MeV 中子与169Tm作用的(n,2n) 反应截面。用蒙特卡罗方法模拟了次级中子的产生，以对实验数据进行中子注量率衰减、多次散射和有限几何修正，同时结合SUNF 方法得到的评价能谱，给出了(n,2n) 反应截面的实验测量结果。测量截面以中子弹性散射微分截面作为标准截面来归一，并用反冲质子望远镜测量n-p 反应的反冲质子，以监视中子注量率。用直接中子法测量得到的结果与评价数据进行了比较，讨论了采用这种方法测量(n,2n) 反应截面的可行性。
(n,2n) reaction cross section from 169Tm at 14.3 MeV was measured with the direct emittedneutron coincidence detecting method, using abnormal fast neutron TOF spectrometer on the HI-13 Tandem Accelerator at CIAE. Monte-Carlo method was used to simulate the generation of secondary neutron and correct the experimental data considering neutron flux attenuation, multiple scattering and finite geometry correction. Combining with evaluated spectra given by SUNF program, the experimental measurement results of the (n,2n) reaction cross sections were given. Cross sections of measurements were normalized by using neutron elastic scattering differential cross section as a standard section, and a recoil proton telescope was used to measure recoiling proton from the n-p reaction to monitor neutron flux rate. After comparing the experimental results with evaluated data, the feasibility of the direct emitted-neutron coincidence detecting method is discussed.
低能D(d,γ)4He辐射俘获反应截面的研究在聚变领域和天体物理等领域中起到非常重要的作用。由于受到标准γ源能量的制约，在研究D(d,γ)4He反应高能γ射线产额实验过程中不能用标准源进行效率刻度。采用实验测量与计算相结合的方法实现NaI探测器对23.8 MeV γ射线的效率刻度，先对6.13MeVγ射线效率进行实验刻度，然后用蒙卡程序MCNP－4C模拟计算出NaI探测器的效率曲线，再用实验数据与模拟结果进行对比校正，计算出NaI探测器在23.8MeV能量点对γ射线的探测效率。该方法对高能γ射线效率刻度给出了一种参考依据。
In the study of D(d,γ)4He radiative capture reactions research, which is very important for fusion and astrophysics, the efficiency calibration of the detector is necessary. Due to the restriction on energy of the standard gamma source, the efficiency calibration of high-energy gamma-rays can not be calibrated by a standard source. In this paper, the method combining the experimental measurements and calculations for the efficiency calibrations of high energy gamma rays is given in the experiment of 6.13MeV gamma rays efficiency calibration using NaI detector, the efficiency curve of which is calculated by MCNP-4C and corrected experimentally. In this case, the detection efficiency of 23.8MeV gamma ray is known. The method provides a reference to high energy gamma ray efficiency calibration.
In this paper an economical and feasible integration solution is introduced for large-scale CCD imaging system. Based on fiber transmission and USB technology, a front control point is designed which can control 4 CCD camera. The control software only has to do small modification for new change. With the design of front control point, a CCD integrated system is established with higher integration and more flexibility.
月表Th 元素分布特征对于分析月表岩石成因及化学特征等提供了重要依据。为了减小嫦娥二号伽玛谱(CE2-GRS) 噪声对获取Th 元素分布特征的影响，提出了一种基于噪声调整的奇异值分解(NASVD) 去噪算法。通过伽玛谱预处理、去噪、本底扣除及净峰面积求解等步骤，获得月表放射性元素Th计数率全月分布图。通过与国内外其他方法所获得的Th 元素计数率分布图对比有较高的一致性。与传统伽玛谱去噪算法比较，聚类NASVD算法能有效地去除统计涨落噪声影响，提取出嫦娥二号伽玛谱中的特征峰信息。
The distribution of thorium on the lunar surface provides the important evidence for lunar evolution history. It is difficult to obtain the distribution of thorium on the lunar surface from CE2-GRS because of noise in the spectrum. The method for smoothing the spectrum is proposed which is based on cluster NASVD. The counting rate map of thorium on the lunar surface is achieved from CE2-GRS. Counting rate map of thorium gamma-rays shows a surface thorium distribution that is in general agreement with other measurement from LP-GRS and SLENE GRS which have better accuracy. It is more effectively to reduce the noise and get the weak information of characteristic peak used the method of cluster NASVD than other traditional methods for smoothing gamma-ray spectrum.
准确测量并计算稀土尾矿砂的放射性活度浓度及其变化规律对制定相应的豁免标准和日后的处理处置具有重要的意义。根据选取的特征 射线，分析对比平衡与非平衡状态下铀系、钍系、锕系三个天然衰变系的总活度浓度，结合衰变链的一般动力学方程，计算总放射性活度与每个核素的放射性活度，并研究钍系各核素在平衡被不同程度破坏的情况下随时间的变化规律。结果显示，按照非平衡情况下计算得出的总α 和总β 放射性活度浓度比平衡情况下的更接近实际测量结果，此外，钍系核素在平衡被破坏后的放射性活度随时间变化情况与母体和228Ra 的初始放射性活度浓度有关，若228Ra 小于232Th，则总放射性活度在60 a再次平衡后达到最大值，为10 倍的母体活度；若228Ra 大于232Th，则总放射性活度在3.82 a 出现最大值，为4.57 倍母体活度与5.25 倍第一子体228Ra 的初始活度浓度之和。因此，可知稀土尾矿砂放射性活度已经遭到破坏，其总活度浓度应该采用非平衡情况下的几个特征核素的活度浓度共同计算得到，并且需计算分析其
It is of great significance to measure and calculate rare earth tailing radioactivity for the development of appropriate standards and exemption disposal. The total activity concentration of the three natural decay series (uranium series, thorium series, actinium series) was analyzed under the equilibrium and disequilibrium state according to the selected characteristic γ-rays. At the same time, we calculated the total activity concentration and the radioactivity for each radionuclide based on the general kinetic equations of decay chain and studied the trend of each radionuclide of thorium-series under different degrees of disequilibrium with time. The results demonstrated that the total radioactivity of and calculated in disequilibrium state was more closed to the actual measurement results compared to that in equilibrium state. In addition, the activity changes with time of thorium series in disequilibrium state are related to the initial activity concentration of the mother nuclide and 228Ra. If the activity concentration of 228Ra is less than that of 232Th, the total activity peak will be 10 times to maternal activity and appear after 60 a when the thorium series become balance again. If the activity concentration of 228Ra is greater than that of 232Th, the maximum total activity will appear in 3.82 a, and will be the sum of 4.57 times of the initial activity concentration of the mother nuclide and 5.25 times of the initial activity concentration of the first daughter 228Ra. Therefore, the rare earth tailings have been in disequilibrium state, and its total activity concentration should be determined based on the activity concentration of several feature radionuclides. In addition, the maximum value of the activity concentration is profitable to judge whether the activity concentration is fit with relevant regulations and standards.
7Li离子属于高LET辐射，是辐射生物学基础研究中常用的重离子射线之一，它是硼中子俘获治疗癌症中起关键作用的离子，在辐射诱变育种等领域也有较好的应用前景。实验在北京HI-13串列加速器R20支线生物用新终端上进行，对43 MeV 7Li离子束斑大小、均匀性和监测注量的准确性进行测量和评估，结果表明：均匀性好于90%的最大束斑面积为5.0cm×5.0cm；4.2×104 ～1.5×105 particles/cm2/s注量率范围内，两种不同探测器测得的注量率变化呈线性关系，闪烁体探测器监测的注量与CR39探测器测得的绝对注量的误差小于10%。这些束流特性能够满足辐射生物学实验要求，有利于进一步开展与硼中子俘获治疗癌症或辐射诱变育种中7Li离子的辐射生物学相关研究。
7Li ion with high linear energy transfer (LET) radiation has been used in radiobiological research, takes main effect in Boron Neutron Capture Therapy and is applied in radiation mutagenic breeding. This experiment was carried on the new terminal established for radiobiological application, located at the end of R20 branch beam line of HI-13 tandem accelerator. The beam qualities of 7Li ions of 43MeV generated by HI-13 tandem accelerator, including spot size and uniformity and particle fluence accuracy were measured using different detection methods. The results showed that beam uniformity was over 90% at 5cm×5cm area, the flux of S1 and M3 had a good linear relationship as particle flux ranged from 4.2×104 particles/cm2/s to 1.5×105 particles/cm2/s, and particle fluence accuracy was better than 90%. All the results showed that the beam qualities of 7Li ions finely met the basic requirements for radiation biological experiment. It provides important method to study biological effects for fundamental research and tumor therapy or radiation mutagenic breeding application associated with 7Li ions.
将替拉扎明(TPZ) 与聚乙二醇包被的金纳米粒子(PEG-GNP) 偶联，形成新型替拉扎明-金纳米粒子复合物(TPZ-PEG-GNP)。利用酶标仪获得TPZ-PEG-GNP 在200 800 nm范围内的紫外-可见光吸收光谱；采用电感耦合等离子体质谱(ICP-MS) 检测TPZ-PEG-GNP 在人肝癌HepG2 细胞中的摄取量；MTT法检测TPZ-PEG-GNP 对HepG2 细胞增殖活力的影响；香豆素-3-羧酸(3-CCA) 羟自由基探针检测X 射线和碳离子辐照下TPZ-PEG-GNP 在水中的羟自由基辐射增强效应；克隆形成法检测X 射线及碳离子辐照下TPZ-PEG-GNP 对HepG2 细胞的辐射增敏效应。实验结果表明：TPZ偶联到PEG-GNP 上形成的TPZPEG-GNP 对HepG2 细胞基本无毒；在有氧条件下，TPZ-PEG-GNP 在水中显著增加X射线和碳离子辐照下的羟自由基产额，对HepG2 细胞具有明显的辐射增敏效应；在X 射线及碳离子辐照下10% 存活水平时，TPZ-PEG-GNP 对HepG2 细胞的辐射增敏比分别为1.23 和1.47。
Tirapazamine (TPZ) was conjugated with polyethylene-glycol-coated gold nanoparticles (PEGGNP) to form new tirapazamine-gold nanoparticle compounds (TPZ-PEG-GNP). UV-vis absorption spectrum of TPZ-PEG-GNP at wavelengths from 200 to 800 nm was measured with a microplate reader. The kinetics
of TPZ-PEG-GNP uptake by human hepatoma HepG2 cells was determined using inductively coupled plasma mass spectrometry (ICP-MS). To evaluate the cellular toxicity of TPZ-PEG-GNP, the effect of TPZ-PEG-GNP on HepG2 cell viability was examined by means of the MTT method. Moreover, the radiation enhancement effect of hydroxide radical production in ultra-pure water with TPZ-PEG-GNP exposed to X-rays and carbon ions was investigated using coumarin-3-carboxylic acid (3-CCA) as the free radical probe. More importantly, the radiosensitizing effect of TPZ-PEG-GNP on HepG2 cells irradiated with X-rays and carbon ions was assessed with the clonogenic survival assay. Our experimental results indicate that TPZ-PEG-GNP had nearly no toxicity to HepG2 cells. The yield of hydroxide radicals in ultra-pure water in the presence of TPZ-PEG-GNP after exposure to X-rays and carbon ions increased obviously and an obvious radiosensitizing effect of TPZ-PEG-GNP on HepG2 cells was observed under aerobic conditions. The radiation enhancement ratio of TPZ-PEG-GNP on HepG2 cells exposed to X-rays and carbon ions was 1.23 and 1.47 at 10% survival level.
单粒子微剂量谱在放射治疗中是一个极其重要的参数，它可以用来评估辐射场的生物学效应。利用蒙特卡洛程序FLUKA模拟计算了由碳离子产生的混合辐射场能量沉积的微观模式。从已公开发表的文献中选取了实验测量300 MeV/u 碳离子的线能能谱，并与相同物理条件下模拟计算得到的线能能谱相比较，结果吻合得很好。此外，还计算了120~430 MeV/u 的碳离子的剂量平均线能能谱、频率平均线能和剂量平均线能。所得到的频率平均线能值为185~ 28.3 keV/m而剂量平均线能值则为272~ 64.1 keV/m。本文的结果对于制定碳离子放射治疗的治疗计划有着重要的意义.
Microdosimetric single event spectrum is a significant parameter in radiotherapy, which can be used to evaluate the radiation biological effect. In this paper, microscopic patterns of energy deposition are simulated with Monte Carlo code FLUKA at mixed radiation fields during carbon ions therapy. The results are compared with experimental measured results at 300 MeV/u carbon ion and good agreement has been found. Meanwhile, dose-weighted lineal energy spectra, frequency averaged lineal energy values and dose averaged lineal energy values of carbon ion with energy from 120 to 430 MeV/u were calculated,
too. The frequency averaged lineal energy values are from 185 to 28.3 keV/m while the dose averaged lineal energy values are from 272 to 64.1 keV/m. These studies are useful for treatment plan in carbon ion radiotherapy.
长链非编码RNA(lncRNA) 是长度超过200 nt、不具有蛋白编码功能的转录本，它们在真核生物中发挥基因调控等重要作用。迄今为止，还没有检索到有关参与电离辐射应答的lncRNA 研究报道。据推测，细胞暴露于电离辐射之后有些lncRNA 的转录水平将发生变化。因此，采用2 Gy 的X射线辐照HeLa 细胞，辐照后4 h 提取总RNA 进行全序列测序。最终发现1 028 种lncRNA 的转录水平发生了改变，其中包括381 种新lncRNA。从中随机挑选24 种lncRNA，用实时荧光定量PCR法验证了2 Gy 的X射线或80 keV/m碳离子束照射后的表达变化，发现其变化趋势和测序结果一致。此研究为电离辐射应答相关lncRNA 的功能研究奠定了基础。
Long non-coding RNAs (lncRNAs) are a class of non-coding transcripts longer than 200 nt and potentially play important roles in eukaryotic gene regulation. However, the quantity, characteristics and expression pattern of lncRNAs responding to ionizing radiation remain largely unknown. We speculate that some lncRNAs participate in the induction of radiobiological effects and ionizing radiation changes their expression levels. In the present study, total RNAs of HeLa cells were isolated 4 h after exposure to 2 Gy of X-rays, and sequenced by lncRNA-seq technology. We identified 647 kinds of known lncRNAs and 381 kinds of novel non-coding sequences responding to ionizing radiation. Subsequently, we verified the expression of 24 lncRNAs after exposure to 2 Gy
X-rays or 80 keV/m carbon ions by using qRT-PCR.
As the coupling component between accelerator and subcritical core, the spallation target is of crucial importance to the operation safety of the whole system. Hence, the spallation target is one of the most important parts in ADS corresponding researches. Due to lifetime limitation of material, the windowless target which has a stable free surface attracts more and more attention. The present paper deals with the experimental investigation on the free surface behavior in an approximately 1:1 size windowless target model using water as test fluid. We can get the flow and pressure conditions of windowless spallation target water simulation experiment from the platform. The free surface and eld visualization were obtained by particle imaging velocimetry. The results show that the position and flow pattern of the free surface depend on experimental pressure, flow velocity and geometry of the target.