天然方解石中~(55)Mn~(2+)离子的各向异性顺磁共振谱

我们研究了天然方解石中~(55)Mn~(2+)离子在微波频率约为9400兆赫频段的顺磁共振谱的精细结构和超精细结构。并对θ=0°及90°之下由实验确定的谱线位置与计算值作了对比,求出了~(55)Mn~(2+)在方解石中的自旋哈密顿参数。结果证明g因子和谱的超精细结构参数有微弱的各向异性。所得到的参数分别为: g_‖=2.0025±0.00012,g_⊥=2.0023±0.00012, D′=(37.97±0.065)×10~(-4)(cm~(-1)), d′=(5.00±0.06)×10~(-7)(cm~(-1)), A=94.0±0.26(Gs),B=93.4±0.26(Gs)。     

噪声作用下不连续不可逆映象中的吸引子湮灭

研究了噪声对一个既不连续又不可逆分段线性映象中共存吸引子动力学行为的影响。在控制参数范围内,系统存在共存的周期5和周期6吸引子。结果发现:弱噪声作用不会影响共存态的行为,在临界噪声强度下,共存态中的一个周期吸引子湮灭,系统由共存态转变成单稳的周期态,且在此临界噪声强度下,吸引子湮灭取决于系统的控制参数D;进一步提高噪声强度,前述周期态进入混沌态。可以用吸引子湮灭或失稳时临界噪声强度描述吸引子的鲁棒性,此鲁棒性在由噪声强度D和控制参数μ组成的参数空间中具有4个不同的动力学区间。     

乙酰胆碱对大鼠离体输精管平滑肌细胞膜电位的作用

采用细胞内微电极技术对大鼠离体输精管平滑肌细胞进行记录,观察其静息电位、膜阻抗等被动膜电性质及ACh对平滑肌细胞膜电位的作用,在此基础上运用微电泳技术对所记录细胞进行标记,从而分析不同走行方向的平滑肌细胞的电生理学特性。实验测得输精管平滑肌细胞静息电位为-48.56±0.46mV(n=1141),膜输入阻抗为1638.70±205.20MΩ(n=45)。实验用ACh(0.3～100μmol L)灌流平滑肌细胞,可引起膜发生浓度依赖性超极化。10μmol LACh引起超极化幅值为13.67±0.98mV(n=116),膜电导平均增加2.31%(n=10)。标本经1μmol L硫酸阿托品(n=10)和100nmol L2' deoxyadenosine5' monophosphate(n=11)预处理后,ACh引起的超极化幅值明显减小。经荧光染料(0.1%propidiumiodide)标记鉴别后,统计分析外纵走行细胞的静息电位为-53.56±3.88mV(n=37),膜输入阻抗为2245.60±372.50MΩ(n=13);内环走行细胞的静息电位为-51.62±4.27mV(n=17),膜输入阻抗为2101.50±513.50MΩ(n=10);并且2种走形方向的平滑肌细胞对ACh的反应形式亦无显著性差异。实验表明:输精管平滑肌细胞的电生理特性以及对ACh的反应与其走形方向无关。     

斑嘴鸭卵的人工孵化研究

研究了人工饲养条件下斑嘴鸭卵的形态学特征、人工孵化及出雏行为等问题,结果表明:鲜卵重平均为6 1.35± 1.89g,长径 5 6.84± 1.30mm,短径 43.5 5± 0.97mm,孵化期为 2 8.0 4± 0.94天;孵化失重率(Y)与孵化天数(X)之间的关系为Y =1.0 10 6 - 0.0 0 72X     

圆映象与Henon映象

分别介绍了圆映象和Henon映象的主要性质和结论.在描述周期与准周期运动时,圆映象是很重要的一种简单映象;Henon映象是一种重要的二维映象,具有一些一维映象所没有的性质.这两种映象对进一步讨论、理解混沌运动有很大的帮助作用.     

基于ADuC812的半导体激光器智能温控及驱动电源设计

设计一种基于ADuC812微控制器的半导体激光器驱动及温控系统,以ADuC812微转换器为控制核心,用单片机的D/A输出和数字PID运算输出分别进行恒流和恒温控制。实验表明:该系统能提供(0-2.5)A长期恒定的电流,纹波系数小于0.1%;温控精度优于±0.02℃。     

猪颌下腺活性肽对大鼠应激性溃疡形成的影响

实验选用体重200—250g S.D.系健康大鼠27只.雌雄不拘。浸水应激6小时后致大鼠产生应激性胃溃疡,并观察猪颌下腺活性肽在其中的作用。结果如下:对照组动物胃溃疡面积密度为17.9±1.43%(平均值±标准误.下同);应激前30分钟腹腔注射颌下腺活性肽0.1mg 组溃疡面积密度为19.1±2.62%;0.2mg 组溃疡面积密度为10.7±1.78%,较对照组减少40.2%(P<0.01);0.5mg 组溃疡面积密度为5.3±0.96%。分别较对照组和0.2mg 组减少70.4%(P<0.001)和50.5%(P<0.01)。统计表明,大鼠胃溃疡面积密度与活性肽注射剂量呈明显的负相关(r=-0.9302,P<0.05)。本工作提示,猪颌下腺活性肽具有阻止或减轻大鼠应激性溃疡形成的作用。     

石龙子rADVR突触结构的定量分析

用实物及计算机投影系统对石龙子前背侧室嵴嘴外侧区突触的电镜图像进行放大处理和统计分析,测量结果:突触前膜平均厚度为70.3×10-10m,后膜平均厚度为117.7×10-10m,突触间隙平均宽度为147×10-10m,突触界面曲率为:平均值±标准差=(1.123±0.389)×10-10m,突触活性带长度为:平均值±标准差=(3 514.93±982.75)×10-10m,空心小泡直径为:平均值±标准差=(477.3±38.45)×10-10m(n=58),实心小泡直径为:平均值±标准差=(892±55.83)×10-10m(n=28).     

圆映象中的混沌运动

本文通过数值实验的方法,研究了Sine圆映象θ_n+1=θ_n+Ω-(n/2π)Sinθ_n的临界性质,测度性质及相图结构,给出了一系列的标度律及k>>1时的相图。     

稀释XY自旋体系的计算机模拟

对自旋体系的平面XY模型进行了模拟计算 ,研究了引入单轴各向异性能项和随机各向异性能项对体系各项性能的影响 ,并得出了磁滞损耗Area与单轴各向异性常数A、随机各向异性常数D和随机各向异性所占比例X的指数标度关系为 :Area～AαDβXγ,且α =0 5 0± 0 0 185 5 ,β≈ 0 ,γ =- 0 2 0± 0 0 0 6 74。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

<正>~~     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to