丰中子奇异核~(17)B的实验研究

在兰州重离子加速器国家实验室(HIRFL)放射性次级束流线(RIBLL)上,用束流透射法测量了丰中子奇异核17B与C靶反应的总截面.假定17B具有15B(核芯)+2n结构,采用Gauss+HO形式的密度分布和零力程Glauber模型进行计算的结果可以很好地拟合实验数据,并得出17B的密度分布有一个很大的弥散,表明17B是双中子晕核.

中能区丰中子核~(11)Li的反应总截面的测量(英文)

利用HIRFL提供的50MeV/u的~(13)C束流轰击Be靶,通过RIBLL选择出放射性核素~(11)Li.实验采用透射法测量了25—45MeV/u的~(11)Li在~(28)Si靶上的反应总截面.采用双参数Gauss密度分布形式,利用Glauber模型很好地拟合了高能和中能区的~(11)Li实验数据,并从密度分布中提取了核的物质均方根半径.

丰中子奇异核17B的实验研究

在兰州重离子加速器国家实验室(HIRFL)放射性次级束流线(RIBLL)上，用束流透射法测量了丰中子奇异核17B与C靶反应的总截面.假定17B具有15B(核芯)＋2n结构，采用Gauss＋HO形式的密度分布和零力程Glauber模型进行计算的结果可以很好地拟合实验数据，并得出17B的密度分布有一个很大的弥散，表明17B是双中子晕核.

Measurement of total reaction cross section for neutron-rich nucleus Li-11 on Si-28 target at medium energy

The neutron-rich nucleus Li-11 is separated by the radioactive ion beam line RIBLL at HIRFL from the breakup of 50MeV/u C-13 on Be target. The total reaction cross sections for Li-11 at energies range from 25 to 45MeV/u on Si target have been measured by using the transmission method. The experimental data at high and low energies can be fitted well by Glauber model using two Gauss density distribution. The matter radius of Li-11 was also deduced.

17B的实验研究

核反应总截面是描述原子核反应基本特征的一个重要的物理量，从中可以得到有关核反应、核结构和核内核子分布的信息。利用透射法测量核的反应总截面对于模型没有依赖性，因而得到的结果更加可靠。在兰州放射性束流线（RIBLL）上利用透射法测量了17B与C、Pb靶的反应，得到了17B与C、Pb的反应总截面和去除双中子截面，同时首次尝试用CLOVER探测器测量与碎片符合的γ能谱。利用半经验的Shen公式可以很好地拟合稳定核的反应总截面的实验结果，但是并不能很好地描述17B的实验结果，说明17B具有奇异结构。采用描述不稳定核的多种密度分布形式代入零力程的Glauber模型计算17B与C的反应总截面，并与实验结果进行了比较。发现采用Skyrme－Hatree－Fock（SHF）、双Gauss、Gauss＋HO计算的密度分布形式都能够很好地拟合整个能区内的实验结果。通过各种密度分布形式提取了17B的核子密度分布，发现17B的中子密度分布有很大的弥散，并证实了17B是由核芯15B加两个价中子组成的晕结构。将Skyrme－Hatree－Fock（SHF）、双Gauss、Gauss＋HO密度分布形式，输入Glauber模型与实验结果比较，提取了17B的物质均方根半径，不同密度分布提取的均方根半径值在实验误差范围内一致，也进一步验证了17B的晕结构。采用Woods－Saxon势来描述17B核外的价中子在核芯中形成的势场，通过解薛定鄂方程来求解价中子处于特定轨道的波函数。假设17B核外的价中子处于纯的s分波和d分波都不能很好地和实验结果符合。所以认为核外的价中子应该是混合组态，通过拟合实验结果求解出s分波谱学因子的值，证明核外的价中子处在2s1/2轨道的几率更大

12N、12B、11C 在Si靶上反应总截面研究

核反应总截面是描述原子核反应基本特征的一个重要的物理量，从中可以得到有关核反应、核结构和核内核子分布的信息。在由放射性束所产生的奇异核结构与各种反应机制的研究中，反应总截面更是具有特殊的重要性。具有奇异核结构的核的一个典型物理现象就是其反应总截面要比稳定核大得多，I.Tanihata等人最早就是通过对放射性束流的相互作用截面的测量发现了具有奇异结构的核－中子晕核。由于反应截面的测量对探测器的要求不高，而且数据分析过程相对较为简单，因此反应截面的测量已经成为放射性束物理研究的一个非常重要的实验手段。目前，奇异核研究的重点在丰中子一侧，理论预言的很多中子晕核如8He、11Li、11、14Be、15、17、19C、等已经从实验上得到证实，而理论预言的质子晕核目前只有8B得到实验证实，其他的核实验数据较少或相互矛盾，无法作出准确的结论。12N就是其中之一，理论学家认为其具有质子晕结构；而实验数据主要集中在的反应截面测量上，实验数据较少又相互矛盾或不肯定，不能得出确切结论。因此，进一步开展研究是十分必要和有意义的。考虑到以上因素，充分利用兰州放射性束流线现有的实验条件，我们采用束流透射法测量了中能区多个能量点12N、11C、12B与Si靶的反应总截面和12N去质子截面。同时用CLOVER探测器测量与碎片符合的γ能谱。利用透射法测量核的反应总截面对于模型没有依赖性，因而得到的结果更加可靠。利用Shen公式和采用各种密度分布形式的零力程Glauber模型计算了12N、11C、12B的激发函数并与实验结果比较，提取了12N、11C、12B的密度分布与核半径，对12N去质子截面作了简单分析。使用Shen公式拟合实验数据时发现，Shen公式在整个能区范围内基本上可以很好的拟合12B、11C的反应数据，但Shen计算得到的12N的反应总截面与实验测量值有明显的差异，计算结果偏小。在使用Glauber模型拟合实验数据之前，分别使用有限力程和零力程Glauber模型拟合了12C＋12C的实验数据。在计算时，两种Glauber模型输入的密度分布采用Gauss密度分布形式。结果显示，使用零力程Glauber模型可以更好的拟合实验数据。分别使用高斯密度分布、HO密度分布、双参数费米密度分布、SHF模型计算得到的密度分布、基于少体模型的Gauss＋尾巴密度分布形式代入零力程Glauber模型拟合实验数据。对于12B、11C、12C，这些密度分布形式代入零力程Glauber模型计算得到的激发函数曲线在整个能区范围内都可以很好的拟合实验数据。但是对于12N，只有基于少体模型的Gauss＋尾巴密度分布形式代入零力程Glauber模型计算得到的激发函数曲线可以拟合实验结果。其他的密度分布形式计算得到的激发函数曲线明显低于实验数据。提取的12B、11C、12N均方根半径显示，12N的核半径明显大于其镜像核12B及其周围的核素。对12B、11C、12N的分析结果表明：12N的密度分布形式和稳定核有明显的不同，最后一个质子的密度分布具有很大的弥散，其可能具有奇异结构。对12N去质子截面的简单分析也表明了这一点

HIRFL剥离器后切束线物理设计

HIRFL is a tandem cyclotron complex for heavy ion. On the beam line between SFC and SSC, there is a stripper. Behind it, the distribution of charge states of beam is a Gauss distribution. The equilibrium charge state Q_0 is selected by 1BO2(a 50° dipole behind the stripper) and delivered to SSC. One of two new small beam line (named SLAS) after 1B02 will be builded in or der to split and deliver the unused ions of charge states (Q_0 ± n) to aspecific experimental area. Q_0 ± n ions are septumed and separated from initial(Q_0) ion beam by two septum magnets SM1, SM2. The charge state selected by SM1 will be Q_0 ± 1(6 ≤ Q_0 < 17), Q_0 ± 2(17 ≤ Q_0 < 33) and Q_0 ± 3 (Q_0 ≥ 33) forming a beam in one of the two possine new beam line with the stripping energy of (0.2 to 9.83 Mev/A), an emittance of 10π mm.mrad in the two transverse planes and an intensity ranging from 10~(11) pps for z ≤ 10 to some 10~5 pps for the heaviest element. Behind SM2, a few transport elements (three dipoles and seven qudrupoles) tra nsport Q_0 ± n beam to target positions T1, T2 (see fig. 1) and generate small beam spots (φ ≤ 4mm, φ ≤ 6mm). The optics design of the beam line has been done based on SLAC-75 (a first and second - order matrix theory). beam optics calculation has been worked out with the TRANSPORT program. The design is a very economical thinking, because without building a new accelerator we can obtain a lower energy heavy ion beam to provide for a lot of atomic and solid state physical experiments

重离子耗散反应激发函数振荡结构的实验研究

直到八十年代中期，人名才发现耗散反应激发函数中存在振荡结构这种新现象。通过对激发函数振荡结构能量自关联函数的研究是获得复合核能级宽度的一个重要手段，Brick推广了Ericson的复合核统计理论，并成功地用于分析耗散反应激发函数振荡结构的研究，提取相应的能量相关宽度Г。本文报道了19F+51V耗散反应激发函数振荡结构的实验研究结果，用能级部分重叠模型对角动量相干引起的截面涨落、能量自关联函数进行了计算分析。实验中采用ΔE-E粒子鉴别方法和飞行时间TOF测量技术队102.25Mev~109.5Mev19F+51V反应类弹产物同时进行电荷和质量鉴别。首次在各个元素、同量异位素（质量数A为常数）和同位素的耗散反应激发函数中观察到振荡结构，并进一步证实了反应产物的各个出射道之间存在着相关。检验了用小角度弹性散射计数做相对归一对激发函数振荡结构研究可能造成的影响。分别采用能量自关联函数方法和谱密度方法提取了各个激发函数的能量相关宽度Г，其值大小为~350kev，并与出射道的电荷数Z、质量数A和中质比N/Z有很大的依赖关系，表明出射产物与入射弹核的差别越打所需的反应时间久越长。首次得到了Г随N/Z值变化的趋势，Г随N/Z的分布为Gauss型，通过分析分布的宽度得到其大小随相互作用时间的增长而线性增大的结果，并进一步提取了电荷扩散系数，证实了反应系统已达到电荷平衡。Г的数值随出射角的增大有减小的趋势。双核系统的转动造成了Г随出射角的变化关系，实验提取的双核系统平均角速度发生了较强的阻尼。用能级部分重叠模型在适当的精度内对激发函数和能力自关联函数进行了模拟。计算分析说明入射道的动能大多数转化为双核系统的转动能，只有较少部分转化为双核系统的内禀激发能，双核系统被激发到能级密度不太大的区域，能级之间的部分重叠引起截面的振荡行为。入射道角动量的相互干涉、双核系统能级的部分重叠和出射道的相互关联使得耗散反应的激发函数表现出其特有的规律性。

Boundary Characterization Experiment Series Overview

Ocean acoustic propagation and reverberation in continental shelf regions is often controlled by the seabed and sea surface boundaries. A series of three multi-national and multi-disciplinary experiments was conducted between 2000-2002 to identify and measure key ocean boundary characteristics. The frequency range of interest was nominally 500-5000 Hz with the main focus on the seabed, which is generally considered as the boundary of greatest importance and least understood. Two of the experiments were conducted in the Mediterranean in the Strait of Sicily and one experiment in the North Atlantic with sites on the outer New Jersey Shelf (STRATAFORM area) and on the Scotian Shelf. Measurements included seabed reflection, seabed, surface, and biologic scattering, propagation, reverberation, and ambient noise along with supporting oceanographic, geologic, and geophysical data. This paper is primarily intended to provide an overview of the experiments and the strategies that linked the various measurements together, with detailed experiment results contained in various papers in this volume and other sources

Mechanical and thermal induced chain conformational transformations in syndiotactic polypropylene (sPP)

Stretching a stacked sPP lamellar morphology at room temperature leads to a mechanical induced transformation from the (t(2)g(2))(2) (helical) into the (tttt) (zigzag) chain conformation of the polymer. The so prepared samples exhibit after annealing above 80 degreesC a thermal induced retransformation into the cell I and cell III crystal structure of the helical chain conformation. The mechanical induced chain conformational transformation as well as the thermal induced retransformation was studied by means of transmission electron microscopy and electron diffraction. (C) 2001 Kluwer Academic Publishers.

可变误差多面体法同时测定镧及其它轻稀土合量

电子计算机应用于分光光度法为同时分析相互干扰的多组分体系开辟了一个新的研究领域。文献报道的线性规划、因素轮换优选、因子分析、正交分解及可变误差多面体法已显示了计算分光光度法的优越性。在所报道的工作中,测定某单组分的吸光常数时,大都没有其它组分共存,依据α=A/bc来计算其吸光常数。但结果产生较大的误差。本文以化学性质极其相似的La、Ce、Pr、Nd、Sm为分析对象,采用五个已知组成的标样,通过全选主元的Gauss消去法求得单组分的吸光常数。据此再用可变误差多面体法求解样品中各组分的浓度。实践证明,此法不仅减小了实验误差和手工计算时间,而且考虑了组分间的相互作用,所以获得比较准确的结果。可变误差多面体法也是解决这类问题更为合适的方法。

基于测角的自主移动机器人定位算法

给出了自主移动机器人定位的两种算法：解析算法和数值算法。解析法公式较以往的简洁。数值算法结合解析法和高斯－牛顿算法，不仅能避免因初值选取不合理而导致求解过程发散的问题，而且能提高运算精度和速度，通过对两种算法的计算机仿真，表明了解析算法具有运算速度快，而数值算法精度高的特点。其结果已用于自主移动机器人的研制中。

基于弹性参数分析的碳酸盐岩储层预测方法研究

Prediction of Carbonate Reservoir Based on the Elastic Parameter Analysis Zhang Guangzhi (Solid Geophysics) Directed by Professor Liu Hong Abstract With the exploration and development of Puguang Oilfield, oil-gas exploration of carbonate rock in China has shown good prospects. Research on earthquake prediction methods for carbonate reservoir becomes the key of oil and gas exploration. Starting with analysis of geological characteristics of carbonate rock, prestack AVO inversion method, prestack elastic impedance inversion and parameter calculation method and seismic attribute extraction and optimization method were studied based on the analysis of rock physics in this work. First, variation characteristic and law of carbonate rock reservoir parameters were studied based on experimental data of rock physics, log data, analysis assay data, mud logging data and seismic data, so as to lay a foundation for the further reservoir identification and description. Then, the structure, type and propagation law of seismic wave field were analyzed through seismic forward modeling of the reservoir, and contact between information from log and geology data with elastic parameters, such as compressional wave and shear wave velocity and density were established, so as to provide a standard for reservoir identification and hydrocarbon detection using seismic reflection characteristics of the research area. Starting with the general concept of inverse problem, through analysis of Zoeppritz equation, three kinds of pre-stack inversion methods were derived and analyzed in detail, the AVO 3-parameter inversion based on Bayesian theory, the prestack AVO waveform inversion method and the simultaneous inversion method, based on the statistical hypothesis of inversion parameters and observation data and the Gauss distribution assumption of noise. The three methods were validated by model data and real data. Then, the elastic wave impedance inversion method of carbonate reservoir was investigated and the method of elastic parameter extraction from elastic impedance data was put forward. Based on the analysis of conventional methods of seismic attribute extraction and optimization, the time-frequency attributes and the wavelet attributes with time and amplitude feature were presented, and the prestack seismic attribute calculation method which can characterize the reservoir rock and fluid characteristic was presented. And the optimization of seismic attribute using the nonlinear KPCA method was also put forward. A series of seismic prediction technologies for carbonate reservoir were presented based on analysis of rock physics and seismic forward simulation technology. Practical application of these technologies was implemented in A oil field of Southern China and good effect has been achieved. Key words: carbonate rock; reservoir prediction; rock physics, prestack seismic inversion; seismic attribute

甘肃临夏盆地龙担剖面晚新生代磁性地层与古环境

Linxia Basin, situated in the northeast belt of the Tibetan Plateau, is a late Cenozoic depression basin bounded by the Tibetan Plateau and the Chinese Loess Plateau. The Cenozoic deposition, spanning over 30Ma, in which very abundant mammal fossils were discovered, is very suitable for study of uplift processes and geo-morphological evolution of the Tibetan Plateau. The Longdan section (35°31′31.6″N，103°29′0.6″E) is famous for the middle Miocene Platybelodon fauna and the late Miocene Hipparion fauna for a long time and is also one of the earliest known places for wooly rhino, which lies on the east slope of Longdan, a small village of township Nalesi in the south of the Dongxiang Autonomous County, Linxia Hui Nationallity Autonomous Prefecture. The Longdan mammal fauna was discovered at the base of the Early Pleistocene loess deposits at Dongxiang, where the lithology is different from the typical Wucheng Loess on the Chinese Loess Plateau. The rich fossils contain many new species and the major two layers of fossils are in the loess beds. Geologically the fossiliferous area is located in the central part of the Linxia Cenozoic sedimentary basin. Tectonically the Linxia Basin is an intermountain fault basin, bordered by the Leijishan major fault in the south and the north Qinling and Qilianshan major faults in the north. The section is 51.6m thick above the gravel layer, including the 1.6m Late Pleistocene Malan Loess on the top and the other loess-paleosol sequences in the middle of the section. The base of the section is the Jishi Formation, consisting of gravel layer of 13 ~ 17m thick. In this study, 972 bulk samples were collected with an interval of 5cm and other 401 orientied samples were taken with a magnetic compass. In the laboratory, the paleomagnetism, medium grain size, susceptibility, color, micromorphology, anisotropy of magnetic susceptibility were analyzed. From the stratigraphic analysis, the Longdan section from the top 0.3m to the bottom 51.6m, containing 5 normal polarities (N1-N5) and 5 reversal polarities (R1-R5). The paleomagnetic results show N3 is the Olduvai subchron in the middle of the Matuyama chron, and then the chronology of the Longdan mammal fauna is constructed along the section. The Matuyama-Gauss boundary is 45m and N5 enters Gauss chron. The Olduvai subchron with the age of 1.77 ~ 1.95Ma is found just in the upper fossiliferous level of Longdan mammal fauna. Taking the deposit rate of the section into account, the geological age of the upper fossiliferous level of Longdan mammal fauna is estimated to be about 1.9Ma. The lower fossiliferous level is just below the Reunion subchron and its age is estimated to be 2.25Ma. In addition, anisotropy of magnetic susceptibility of the loess-paleosol and other climatic indexes were used for discussing the late Cenozoic paleoenvironmental changes at Longdan, from which the Longdan area should have been an area of predominantly steppe the same as the Longdan mammal fauna.

三维油藏数值模拟正反演算法研究

The dynamic prediction of complex reservoir development is one of the important research contents of dynamic analysis of oil and gas development. With the increase development of time, the permeabilities and porosities of reservoirs and the permeability of block reservoir at its boundaries are dynamically changing. How to track the dynamic change of permeability and porosity and make certain the permeability of block reservoir at its boundary is an important practical problem. To study developing dynamic prediction of complex reservoir, the key problem of research of dynamic prediction of complex reservoir development is realizing inversion of permeability and porosity. To realize the inversion, first of all, the fast forward and inverse method of 3-dimension reservoir simulation must be studied. Although the inversion has been widely applied to exploration and logging, it has not been applied to3-dimension reservoir simulation. Therefore, the study of fast forward and inverse method of 3-dimension reservoir simulation is a cutting-edge problem, takes on important realistic signification and application value. In this dissertation, 2-dimension and 3-dimension fluid equations in porous media are discretized by finite difference, obtaining finite difference equations to meet the inner boundary conditions by Peaceman's equations, giving successive over relaxation iteration of 3-dimension fluid equations in porous media and the dimensional analysis. Several equation-solving methods are compared in common use, analyzing its convergence and convergence rate. The alternating direction implicit procedure of 2-dimension has been turned into successive over relaxation iteration of alternating direction implicit procedure of 3-dimension fluid equations in porous media, which possesses the virtues of fast computing speed, needing small memory of computer, good adaptability for heterogeneous media and fast convergence rate. The geological model of channel-sandy reservoir has been generated with the help of stochastic simulation technique, whose cross sections of channel-sandy reservoir are parabolic shapes. This method makes the hard data commendably meet, very suit for geological modeling of containing complex boundary surface reservoir. To verify reliability of the method, theoretical solution and numerical solution are compared by simplifying model of 3-dimension fluid equations in porous media, whose results show that the only difference of the two pressure curves is that the numerical solution is lower than theoretical at the wellbore in the same space. It proves that using finite difference to solve fluid equations in porous media is reliable. As numerical examples of 3-dimension heterogeneous reservoir of the single-well and multi-well, the pressure distributions have been computed respectively, which show the pressure distributions there are clearly difference as difference of the permeabilities is greater than one order of magnitude, otherwise there are no clearly difference. As application, the pressure distribution of the channel-sandy reservoir have been computed, which indicates that the space distribution of pressure strongly relies on the direction of permeability, and is sensitive for space distributions of permeability. In this dissertation, the Peaceman's equations have been modified into solving vertical well problem and horizontal well problem simultaneously. In porous media, a 3D layer reservoir in which contain vertical wells and horizontal wells has been calculated with iteration. For channel-sandy reservoir in which there are also vertical wells and horizontal wells, a 3D transient heterogeneous fluid equation has been discretized. As an example, the space distribution of pressure has been calculated with iteration. The results of examples are accord with the fact, which shows the modification of Peaceman's equation is correct. The problem has been solved in the space where there are vertical and horizontal wells. In the dissertation, the nonuniform grid permeability integration equation upscaling method, the nonuniform grid 2D flow rate upscaling method and the nonuniform grid 3D flow rate upscaling method have been studied respectively. In those methods, they enhance computing speed greatly, but the computing speed of 3D flow rate upscaling method is faster than that of 2D flow rate upscaling method, and the precision of 3D flow rate upscaling method is better than that of 2D flow rate upscaling method. The results also show that the solutions of upscaling method are very approximating to that of fine grid blocks. In this paper, 4 methods of fast adaptive nonuniform grid upscaling method of 3D fluid equations in porous media have been put forward, and applied to calculate 3D heterogeneous reservoir and channel-sandy reservoir, whose computing results show that the solutions of nonuniform adaptive upscaling method of 3D heterogeneous fluid equations in porous media are very approximating to that of fine grid blocks in the regions the permeability or porosity being abnormity and very approximating to that of coarsen grid blocks in the other region, however, the computing speed of adaptive upscaling method is 100 times faster than that of fine grid block method. The formula of sensitivity coefficients are derived from initial boundary value problems of fluid equations in porous media by Green's reciprocity principle. The sensitivity coefficients of wellbore pressure to permeability parameters are given by Peaceman's equation and calculated by means of numerical calculation method of 3D transient anisotropic fluid equation in porous media and verified by direct method. The computing results are in excellent agreement with those obtained by the direct method, which shows feasibility of the method. In the dissertation, the calculating examples are also given for 3D reservoir, channel-sandy reservoir and 3D multi-well reservoir, whose numerical results indicate: around the well hole, the value of the sensitivity coefficients of permeability is very large, the value of the sensitivity coefficients of porosity is very large too, but the sensitivity coefficients of porosity is much less than the sensitivity coefficients of permeability, so that the effect of the sensitivity coefficients of permeability for inversion of reservoir parameters is much greater than that of the sensitivity coefficients of porosity. Because computing the sensitivity coefficients needs to call twice the program of reservoir simulation in one iteration, realizing inversion of reservoir parameters must be sustained by the fast forward method. Using the sensitivity coefficients of permeability and porosity, conditioned on observed valley erosion thickness in wells (hard data), the inversion of the permeabilities and porosities in the homogeneous reservoir, homogeneous reservoir only along the certain direction and block reservoir are implemented by Gauss-Newton method or conjugate gradient method respectively. The results of our examples are very approximating to the real data of permeability and porosity, but the convergence rate of conjugate gradient method is much faster than that of Gauss-Newton method.