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1.
高能族事例中的能量集中现象   总被引:2,自引:0,他引:2  
给出了甘巴拉山乳胶室观测的族事例中横向的能量分布,与MONTECARLO模拟计算作了比较.指出超高能族事例中存在着能量集中的特征.  相似文献   

2.
在不同能量下, 利用核束缚能对虚光子四动量的平方项进行修正, 分别计算了Sn核碰撞中核束缚能对反应截面中湮灭项和康普顿散射项及K因子的影响。 结果表明, 核束缚能在小x区域对反应截面中湮灭项和康普顿散射项及K因子的影响明显, 并且能量越低这种影响越显著, 随着x2增大影响逐渐消失。 We made a revision of square of virtual photon four momentum by means of using nuclear bin ding energy formula in different energy, and we also made an accurate calculation for the effect of nuclear binding energy on K factor and Compton term and annihilate term in the Drell Yan process of the Sn Sn collision. The outcome indicates that the effect of nuclear binding energy on the annihilate term and the Compton term is marked in little x region and the effect will become more obvious with decrease of the energy and come to disappear with increase of the x.  相似文献   

3.
光束截面的能量守恒及能量衍射发散度   总被引:1,自引:0,他引:1  
曹清  郭弘 《光学学报》1996,16(4):89-393
证明了任何一个在真空中稳态传输的单色标量光束,在忽略了瞬逝波的条件下,其光束截面能量的径向分量E及轴向定量E都与轴坐标无关,它们都为不变量,文中还进一步给出了光束能量衍射分散度的X,Y分量的表达式。  相似文献   

4.
Understanding design principles of biomolecular recognition is a key question of molecular biology. Yet the enormous complexity and diversity of biological molecules hamper the efforts to gain a predictive ability for the free energy of protein-protein, protein-DNA, and protein-RNA binding. Here, using a variant of the Derrida model, we predict that for a large class of biomolecular interactions, it is possible to accurately estimate the relative free energy of binding based on the fluctuation properties of their energy spectra, even if a finite number of the energy levels is known. We show that the free energy of the system possessing a wider binding energy spectrum is almost surely lower compared with the system possessing a narrower energy spectrum. Our predictions imply that low-affinity binding scores, usually wasted in protein-protein and protein-DNA docking algorithms, can be efficiently utilized to compute the free energy. Using the results of Rosetta docking simulations of protein-protein interactions from Andre et al. (Proc. Natl. Acad. Sci. USA 105:16148, 2008), we demonstrate the power of our predictions.  相似文献   

5.
于洵  王慧  聂亮  刘宝元 《光子学报》2009,38(5):1052-1057
针对锥形腔高能激光计后向散射能量损失补偿问题,系统分析了均匀分布激光入射强漫反射面情况下的锥形吸收腔的后向散射问题,进而针对不同高能量激光的输出光斑形状,建立了锥形吸收腔开口处光功率密度分布和后向散射总功率的数学模型,在此基础上对测量结果进行了补偿和修正,有效改善了高能量激光能量测量准确度.  相似文献   

6.
李强  卫增泉  马受武 《中国物理 C》1995,19(12):1078-1083
根据我们建立的径迹结构Monte Carlo计算模型,计算了低能电子在液态水中径迹范围内DNA分子片段模型和染色质丝片段模型区域内的能量沉积频率分布,结果与OREC和CPA程序结果进行了比较,这些计算结果为解释低能重离子注入生物体造成深部生物效应而提出的一种物理机制──软X射线机制提供了理论依据.  相似文献   

7.
高能激光能量计校准方法研究   总被引:1,自引:3,他引:1  
刘国荣  吴洪才 《光子学报》2007,36(6):982-985
给出了一种绝对式高能激光能量计光电校准方法.该方法以大功率灯作为校准光源,通过测量灯两端的电压以及电流获得电能值,去掉灯所消耗的热能,得到灯所发出的光能.所设计平板能量计将大功率灯密封在高能激光能量计内,光能全部被能量计吸收.根据能量计输出值以及光能值便可实现能量计光电校准.结果表明,能量计光电校准不确定度约为1.5%.  相似文献   

8.
崔元顺 《光子学报》2008,37(8):1684-1687
针对介观电子谐振腔模型,在由电荷算符本征态构成的新Fock空间中,假设系统具有变换的对称性,通过求解Hamilton算符的本征值方程,给出系统的量子能谱关系.在电荷算符的Fock态下计算能量的量子涨落,分析和研究电子谐振腔的量子能谱性质.结果表明:类似于电荷的量子性,能谱明显地呈现出离散性,其大小决定于谐振腔的电参量、形状因子及栅极所加偏压等因素;而能量的量子涨落却仅与电荷量子、Planck常数以及系统自感有关.  相似文献   

9.
Dark Energy     
  相似文献   

10.
非电离能损(NIEL)引起的位移损伤效应是空间装置失效的原因之一. 运用改进的Monte Carlo程序SHIELD, 建立了质子的NIEL计算手段, 模拟计算了能量范围在10—400MeV的中能质子在硅和砷化镓中的NIEL的大小和分布.  相似文献   

11.
为了研究带电粒子与活体细胞的相互作用,利用能量为2,2.5,3 MeV的质子外束,在室温环境下对厚约50 nm的氮化硅支持膜上的毕赤酵母菌进行辐照,并用金硅面垒探测器测量其透射能谱,通过对能量沉积特性的分析,表明质子外束穿过毕赤酵母菌后能损随入射能的增大而减小,但能量歧离随入射能的增大而增大。To study the interaction of charged particles with biological living cells,we delivered 2,2.5 and 3 MeV protons outside vacuum as external beam at room temperature to irradiate yeast Pichia cells which are supported by 50 nm thick silicon nitride film and the transmission energy spectrum were measured by an Au-Si surface barrier detector to analyze energy deposition properties.The results demonstrate that the energy loss decreases with the incident protons energy increase,but the energy straggling increases with incident protons energy increase.  相似文献   

12.
为了研究 MeV能量离子在生物样品中的能量损失与能量离散, 分别使用1.0, 1.8和2.8 MeV质子和4.5 MeV氦离子分别辐照不同质量厚度的洋葱内表皮膜。 当质子穿过该生物样品后, 可以利用透射能谱测量透射离子的能量损失和能量离散。 实验结果显示, 在以上的生物样品中, MeV能量离子的能量损失值和TRIM程序模拟的结果相吻合, 但是透射离子的能量离散值却与TRIM程序模拟结果有很大的不同。 结合生物样品的结构不均匀的特性, 对Bohr能量离散理论进行了修正, 并发现修正后的Bohr能量离散理论计算结果与实验值符合得很好。  相似文献   

13.
It is shown in this note that the modified form of the Lippincott-Schroeder potential function [1, 2] which has been extensively used by us in theoretical studies of the vibrational spectra of liquid water [3, 4] gives a reasonably good value of the bond energy.  相似文献   

14.
Proton energies and strengths of (p, γ), (p, p1), (p, p2) and (p, 1γ) resonances of the 27Al + p reaction were determined for Ep < 2.5 MeV. The γ-decay of 78 resonances and 46 bound levels was established and four new bound levels were found at Ex = 9793.8±2.0, 10513.5±1.0, 10884.1±2.0 and 11778.8±1.5 keV. The level at Ex = 11.43 MeV was found to be a doublet. Lifetimes of 25 bound levels were measured by means of the Doppler-shift attenuation technique. Angular distributions were measured at 15 resonances.  相似文献   

15.
采用一种仔细考虑了作用截面、表面弥散和形变效应的核碰撞几何,同时考虑到在每一次碰撞中领头质子损失能量,得到了高能p-Al碰撞的横能分布,计算结果与200GeV/cp-Al、Cu及U碰撞的实验数据符合.In this paper, the nuclear collision geometry which was considered carefully in the interaction cross sections, surface effects and nuclear deformations is adopted. The energy loss of leading proton in each collision is considered. The transverse energy distributions in high energy p A collisions are obtained. The calculated results are in agreement with the experiment data of 200 GeV/ c p Al, Cu and U collisions.  相似文献   

16.
Many-body perturbation theory is used for relativistic calculations of energy levels and of fine-structure intervals for 20 lower states of francium. The zeroth-order approximation is obtained by the relativistic Hartree-Fock method. The second-order correlation corrections are calculated. The accuracy for the s, p and f energy levels is not worse than 0.5%.  相似文献   

17.
Fifty-one levels in Tm168 have been observed up to an excitation energy of 1514 keV utilizing 12-MeV deuterons and the reaction Tm169(d, t)Tm168. The Q value of the lowest observed state was determined to be −1776 ± 15 keV. The spectrum below 700 keV has been interpreted in terms of the coupling of the [411↓] Nilsson proton orbital with the neutron orbitals prominent in the low-energy (d, t) spectrum of Er167. This interpretation has resulted in the determination of relative energies due to the residual neutron-proton interaction for six different configurations. The observed singlet-triplet splitting energies for the [633↑], [521↓], and [512↑] neutron orbitals coupled to the [411↓] proton orbital were measured to be −157, +191, and −234 keV, respectively. Theoretical calculations of these energies made for a zero range spin-dependent central potential gave values of −87, +154, and −255 keV, respectively. The good agreement indicates that the spin-spin interaction can account for most of the singlet-triplet splitting energy.  相似文献   

18.
For close range(almost 8-15km) propagation,bottom-bounce energy(BBE) usually suffers from a great transmission loss due to a large grazing angle interacting with the ocean bottom,and the surface duct energy leakage(SDEL) might be able to make a significant contribution to shadow zone insonification.This study aims at making a comparison between SDEL and BBE in a shadow zone with a source depth of 50 m for close range propagation.Analysis of experimental data shows that for lower frequencies the SDEL can be comparable with the BBE up to a range of 12 km.Numerical simulations suggest that the transmission loss(TL) of 90 dB is a proper value to quantify the role of the SDEL in shadow zone insonification.When TL of the SDEL is about 90 dB,it is believed to be comparable with the BBE.Studies on the effect of mix layer depth(MLD) on the SDEL indicate that larger MLD and lower frequencies can help to create favorable conditions for SDEL and that there exists- an optimal MLD for SDEL at certain frequency.Statistics of MLD distribution in the South China Sea(SCS) show that winter is favorable for SDEL and the situation reverses in summer.Eddies are known to occur frequently in the SCS and the study on the effect of eddies on the SDEL suggests that the presence of an eddy will influence the SDEL significantly by modifying the MLD.  相似文献   

19.
刘国荣  吴洪才 《光子学报》2007,36(7):1335-1337
对绝对量热式高能激光能量计测温电阻丝的温度特性进行了研究.以锥形吸收腔高能激光能量计为实验模型,分别对处于自由状态下以及缠绕于能量计吸收腔表面后的测温电阻丝的温度电阻特性进行了实验分析.结果表明,两种状态下测温电阻丝的电阻随温度变化规律并不相同.用最小二乘法对测温电阻丝的电阻与温度实验数据进行数据处理并建立补偿模型,从而对缠绕于吸收腔表面后的测温电阻丝的电阻温度关系标定,经修正后能量计的测温电阻和Pt100电阻的偏差小于0.01 Ω,温度偏差小于0.02 ℃,从而提高了能量计测温准确度.  相似文献   

20.
假定强子-核作用中的产生粒子相对于反应体质心系各向同性衰变,给出了强子-核作用中横能快度分布,计算结果能够解释最新的HELIOS合作组的实验结果.  相似文献   

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