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1.
利用广义Rostoker公式把Klimontovich碰撞项和BBGKY碰撞项化成同一种形式,从而启示可以建立解相对论BBGKY方程链的方法,而且这种方法与Flimontovich方法有深刻的内在联系。  相似文献   

2.
第一代夸克-轻子是组成所有粒子的基元,第二、第三代由二正一反基元组成,夸克和轻子不混合时正好只能形成对称的3代正反基元组成联系于弱电相互作用量子───光子,W ̄±,Z ̄0和强相互作用的基态介子。这种结构是最简洁的和对称的,也是和某些已知模型一致的。夸克-轻子如果混合还可以组成其它粒子。根据s-c夸克的对称性,由u,d,c组成的重味强子可以分为SU(3)的8重态、10重态,并导出相应的简单的质量公式,由此可以预言若干强子的质量,如或3673MeV.同时,推广Ross模型能得到τ的结构模型,其质量公式和已知的α_s值及1992年BEPC测得的最新质量完全一致。  相似文献   

3.
相对论二体关联方程   总被引:1,自引:1,他引:0  
基于博格留鲍夫关于体系趋向平衡态或定态弛豫过程的准静态假设,讨论了相对论二体关联方程的两种解法。一种适用于似稳电磁相互作用,另一种适用于完全电磁相互作用。  相似文献   

4.
Codel定理是数理逻辑发展中的一个里程碑,但其最初表述并不完善,Rosser公式克服了Godel定理之不足,从而最终解决了形式数论系统的完备性,本文深入分析了Godel提出“ω无矛盾”的初衰和Rosser公式的构造思路,运用Rosser公式对偶对形式,并给出了与此相关的定理,通过这一研究将深化人们对数学系统相容悸 、完备性的认识。  相似文献   

5.
利用解析开拓和Plemelj公式,将上半平面的Poisson公式推广到适用于在上半平面无界的函数及在实轴上除了有限个点处有低于一阶的奇异性外为Holder连续的函数。  相似文献   

6.
减少飞机起飞质量和空载质量估算误差研究   总被引:2,自引:0,他引:2  
目的 研究减少飞机概念设计时空载质量和起飞质量估算误差。方法 通过对一些新型运输飞机的基型和衍生型数据进行统计分析研究,拟合出空载质量估算相对误差与航程之间的二阶多项式关系曲线,导出飞机起飞质量、空载质量和航程之间的关系式,改进了Roskam的空载质量估算公式,通过对利用Roskam估算公式和改进后Roskam估算公式的计算结果分析对比,得出了较为满意的结果。结果 空载质量和起飞质量的估算误差范围  相似文献   

7.
利用Parserval定理,本文给出了一种仅需通过矩阵运算就可直接确定矩阵Lyapunov方程解的公式。方法适用于稳定系统且无其它限制条件,算法简洁,附算例。  相似文献   

8.
蔷薇科10种野生植物籽油脂肪酸研究   总被引:2,自引:0,他引:2  
本研究测定了采自青地海境内蔷薇科Rosa,Prunus,Malus三个属的十种植物种子脂肪酸组成及含量,结果表明,所测植物种子油脂中,主要含有十八碳不饱和脂肪酸,其中,油酸在Prunus属的植物种子油脂含量最高,亚油酸在Malus和Rosa属的植物处子油脂中含量最高,此外,Rosa属还含有较多的亚麻酸,对国内其它地区同类植物种子油脂脂肪酸组成的测定数据进行统计分析,其结果与本研究结论相同。  相似文献   

9.
采用包括库仑长程相互作用的扩展的紧束缚模型,研究了一维强关联体系-顺式聚乙炔(cis-PA)中极化子和双极化子的稳定性。发现库仑相互作用较弱时,双极化子稳定;库仑相互作用较强时,极化子稳定。  相似文献   

10.
讨论简单热带海气耦合模式中的低频海洋扰动,研究结果表明,挟卷对海洋Rossby波的发展起抑制作用,而一流有利于海洋Rossby波的发展,挟卷和平流博得都有利于与海温距平相对应的扰动U的发展。  相似文献   

11.
在相对论磁化等离子体内,除库仑和感应电场力外,粒子间的感应磁场力相互作用将对广义玻耳兹曼方程中碰撞项有贡献.本文导出了这个碰撞项的解析表式.  相似文献   

12.
在相对论磁化等离子体内,粒子间辐射电场力对广义玻耳兹曼方程中碰撞项的贡献不能忽略。本文导出了这碰撞项的解析表式。  相似文献   

13.
Nanometre- and micrometre-sized charged particles at aqueous interfaces are typically stabilized by a repulsive Coulomb interaction. If one of the phases forming the interface is a nonpolar substance (such as air or oil) that cannot sustain a charge, the particles will exhibit long-ranged dipolar repulsion; if the interface area is confined, mutual repulsion between the particles can induce ordering and even crystallization. However, particle ordering has also been observed in the absence of area confinement, suggesting that like-charged particles at interfaces can also experience attractive interactions. Interface deformations are known to cause capillary forces that attract neighbouring particles to each other, but a satisfying explanation for the origin of such distortions remains outstanding. Here we present quantitative measurements of attractive interactions between colloidal particles at an oil-water interface and show that the attraction can be explained by capillary forces that arise from a distortion of the interface shape that is due to electrostatic stresses caused by the particles' dipolar field. This explanation, which is consistent with all reports on interfacial particle ordering so far, also suggests that the attractive interactions might be controllable: by tuning the polarity of one of the interfacial fluids, it should be possible to adjust the electrostatic stresses of the system and hence the interparticle attractions.  相似文献   

14.
To understand the physical processes that occur in nature we need to obtain a solid concept about the 'fundamental' forces acting between pairs of elementary particles. It is also necessary to describe the temporal and spatial evolution of many mutually interacting particles under the influence of these forces. This latter step, known as the few-body problem, remains an important unsolved problem in physics. Experiments involving atomic collisions represent a useful testing ground for studying the few-body problem. For the single ionization of a helium atom by charged particle impact, kinematically complete experiments have been performed since 1969 (ref. 7). The theoretical analysis of such experiments was thought to yield a complete picture of the basic features of the collision process, at least for large collision energies. These conclusions are, however, almost exclusively based on studies of restricted electron-emission geometries. Here, we report three-dimensional images of the complete electron emission pattern for the single ionization of helium by the impact of C6+ ions of energy 100 MeV per a.m.u. (a four-body system) and observe features that have not been predicted by any published theoretical model. We propose a higher-order ionization mechanism, involving the interaction between the projectile and the target nucleus, to explain these features.  相似文献   

15.
广义球对称带电蒸发黑洞周围时空中标量粒子的能量   总被引:1,自引:0,他引:1  
利用弯曲时空中标量粒子运动的Hamilton-Jacobin方程,研究广义球对称带电蒸发黑洞周围时空中标量粒子的能量.得到了粒子的能量不仅与粒子的质量有关,还与黑洞的时空结构及视界的变化率有关.给出了发生自发辐射的能量条件.  相似文献   

16.
用球函数加法公式的坐标变换法与电势叠加原理导出了双环静电问题的电势解;继而由带电体系的互能与虚功原理给出了带电双环的相互作用力表达式并作了特殊讨论.  相似文献   

17.
探讨橡胶混凝土之改善,借由橡胶表面改质技术的开发,并应用原子力显微镜直接量测橡胶以水泥水化物间之作用力,以作为橡胶表面改质的参考.文中除做简单之文宪回顾外,并以三种表面改质技术为例,说明橡胶混凝土改进方法之研究方法.  相似文献   

18.
以Mohr-Coulomb模型描述岩石,在LS-DYNA中用SPH(Smootheed Particle Hydrodynamics)法模拟三维刀齿切削破岩,探讨切削参数和岩石性质对切削力的影响.基于切削力随各切削参数和岩石性质的变化规律,建立切削力估算公式.用所得公式计算切削力,并与实验值进行比较.仿真结果表明:切削厚度、切削前角、切削宽度、岩石的内聚力和内摩擦角对切削力影响显著,切削速度在较低范围内变化时对切削力影响非常小.三维切削仿真能够较好地反映刀齿两侧岩石颗粒对切削的影响,比二维理论模型更接近实际.所得切削力估算公式能准确计算仿真中的平均切向力,且其计算值能与实验吻合较好.验证了基于SPH法的数值仿真用于研究刀齿切削破岩的可靠性.  相似文献   

19.
A modified complex coacervation-co-precipitation method was used to prepare bone morphogenetic protein (BMP)-loaded nanospheres. Three natural polymers were used as packing materials to obtain nanoscale delivery device for BMP, in the presence of phosphatidylcholine functioning as stabilizer. Positively charged polysaccharide, N,N-diethylaminoethyl dextran (DEAE-dextran) tended to form stable, uniform and smaller size particles carrying BMP. Negatively charged bovine serum albumin (BSA) induced precipitation of the produced BMP particles due to its weak interaction with BMP molecules, although it produced nanosized BMP spheres. While collagen, a weakly positively charged protein shaped larger particles due to the strong interaction among themselves. A mechanism of co-precipitation process was also deduced to depict the formation of stable nanospheres.  相似文献   

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