四夸克态质量的一相对论夸克模型研究

考虑四夸克态是双夸克和双反夸克的束缚态, 在一相对论夸克模型下利用变分法计算了轻重四夸克态的质量. 采纳夸克-夸克及双夸克-双反夸克之间的相互作用为单胶子交换势与标量和矢量线性禁闭混合势的总和, 使用拟合基态介子质量得到的参数作为输入, 计算了0++的轻、重四夸克态的质量. 计算的结果支持X(3872), Y(3940)是含有粲夸克的0++重四夸克态;f0(600), κ(800), f0(980)和a0(980)是0++的轻四夸克态.     

四夸克态质量的—相对论夸克模型研究

考虑四夸克态是双夸克和双反夸克的束缚态，在—相对论夸克模型下利用变分法计算了轻重四夸克态的质量．采纳夸克-夸克及双夸克-双反夸克之间的相互作用为单胶子交换势与标量和矢量线性禁闭混合势的总和，使用拟合基态介子质量得到的参数作为输入，计算了0^＋＋的轻、重四夸克态的质量．计算的结果支持X（3872），Y（3940）是含有粲夸克的0^＋＋重四夸克态；fo（600），x（800），fo（980）和ao（980）是0^＋＋的轻四夸克态．     

四夸克系统的分子态结构研究

考虑分子态结构,利用非相对论夸克模型对S波udcc,udbb做了系统研究.借助于精确少体计算方法(多高斯展开算法),并考虑颜色1(×) 1,8(×)8之间的耦合,得到了同位旋和角动量为(I,JP)=(0,1+)的ud(c)(c),ud(b)(b)束缚态.     

多夸克系统中的湮灭相互作用与新强子态X(3872)研究

考虑多夸克系统内部正反夸克对湮灭为有效胶子,推导出了湮灭相互作用势;在不修改夸克模型参数的情况下,研究了ccuu系统的能谱,不仅合理地解释了新强子态X(3872),而且还发现了J~(PC)=2~(++)的D~(0*)D~(0*)弱束缚态,并为BES和LHCb等国际实验合作组探测该粒子提出了建议.     

含有qqqq(q)分量的八重态重子味波函数的构造

在色夸克团模型的基础上,利用张量表示的方法构造含有五夸克成分的八重态重子味波函数.     

关于X(3872)作为粲夸克偶素类四夸克态的色旋机制的进一步讨论

分析了四夸克态的不同耦合道的色旋组态及不同耦合道的色旋组态之间的变换,进而采用拟合介子和重子质量得到的参数,在夸克间的色旋耦合相互作用下计算了X(3872)作为粲夸克偶素类四夸克态(cqcq--)(q=u,d)的质量,并在色旋机制下对X(3872)作为双夸克一双反夸克态和分子态进行了讨论.

Abstract：

Color-spin configurations and transformations between color-spin configurations in different coupled channels are analyzed. The mass of X(3872) is estimated in the color-spin force with the parameters obtained by fitting the masses of mesons and baryons. The X(3872) is discussed as a diquark-diquark bound state and as a molecular state.     

夸克、轻子的广义旋量及形变振荡量子

定义广义旋量Z3=I3+C3+t3,避免了三代夸克、轻子间质量分裂大及超荷多值性困难.三代费米型夸克、轻子的I3F,C3F,t3F,YF间及它们的超对称伴子三代玻色型反夸克、反轻子的I'3B,C'3B,t'3B,Y'B间均满足超荷-旋量变换.用群论及粒子振动的亚夸克流代数分析推算,也能获得相符的结果.     

寒地水稻应用夸克生物富硒多元活菌叶面肥试验效果

为了研究夸克生物富硒多元活菌叶面肥产品对水稻试验效果,通过本试验得出以下结论:水稻喷施夸克生物富硒多元活菌叶面肥后,成熟期比常规施肥提前1d,实粒数比常规每穗多4粒,提高结实率4.1个百分点,进而增加水稻产量.每公顷增产343.5kg,增产率3.71％,公顷增加效益285元.     

夸克生物多元活菌叶面肥在玉米上应用效果

夸克生物多元活菌叶面肥是一种微生物菌剂,含有大量的有益菌,有效活菌数≥2亿/mL.为检验该产品在玉米上的应用效果,探讨其使用技术,特设该试验.结果表明:施用夸克生物多元活菌叶面肥的处理与常规施肥对照相比,公顷增加产量415.5kg,增产率4.1％,公顷增加效益327.30元.     

夸克、轻子的广义旋量及形变振荡量子

定义广义旋量Z3=I3＋C3＋t3,避免了三代夸克、轻子间质量分裂大及超荷多值性困难．三代费米型夸克、轻子的I3F,C3F,t3F,YF间及它们的超对称伴子三代玻色型反夸克、反轻子的I＇3B,C＇3B,t＇3B,Y＇B间均满足超荷-旋量变换．用群论及粒子振动的亚夸克流代数分析推算,也能获得相符的结果．     

The Fundamental Nuclear Interaction: Important developments of the past decade on mesons and the theory of nuclear forces are described

GOPEB based upon known mesons have been found which realistically describe a massive accumulation of the experimental nuclear data up to 400 Mev. The N-N potential according to these models consists primarily of weak residual central terms surviving the cancellation of large repulsive and attractive vector and scalar static components; relativistic interactions arising from the exchange of pseudoscalar, vector, and scalar mesons and dipole type terms arising from the rho meson. The major dynamic terms are direct analogs of magnetic interactions illustrated in Fig. 1. Allowance must be made for the effective dependence of the coupling constants upon spin and isospin states. The nucleons are distributed sources which give rise to nonsingular generalized Yukawa functions in N-N potentials.     

Nucleon stability: a geochemical test independent of decay mode

By analyzing published geochemical data on xenon isotopes measured in a 2.46 x 10(9)-year-old telluride ore, a lower limit of 1.6 x 10(25) years has been obtained for the mean lifetime of the nucleons in the tellurium-130 nucleus. This result is insensitive to the particular mode by which the nucleons decay and therefore provides a rigorous limit on possible baryon number nonconservation. The new limit is about two orders of magnitude better than the previous rigorous limit on nucleon stability.     

On Nucleon-Antinucleon Symmetry in Cosmology

It has been suggested that cosmological models should embody an initial nucleon-antinucleon symmetry and that the present ratio of nucleons to antinucleons is the result of a statistical fluctuation. Simple arguments are presented for evolutionary models which appear to rule out this possibility in the development of the universe.     

纺字考

纺是将丝加工为纱线,是织的基础。纺字从丝从方,丝是纺的意义范畴,方为声兼意符。方有合并之意,纺的并若干根丝为纱线之意即从此出。而先秦文献中纺有下垂、悬吊之意,这种用法实由纺纱引申而来。在纺车出现以前,以纺轮纺线,丝线通过拈杆悬吊纺轮,搓动纺轮旋转,将数根丝合并在一起加捻成一股,成为供织造用的纱线。对纺字意义的考释有利于正确理解原始的纺织工具及使用方法。     

Observation of the spin hall effect of light via weak measurements

We have detected a spin-dependent displacement perpendicular to the refractive index gradient for photons passing through an air-glass interface. The effect is the photonic version of the spin Hall effect in electronic systems, indicating the universality of the effect for particles of different nature. Treating the effect as a weak measurement of the spin projection of the photons, we used a preselection and postselection technique on the spin state to enhance the original displacement by nearly four orders of magnitude, attaining sensitivity to displacements of approximately 1 angstrom. The spin Hall effect can be used for manipulating photonic angular momentum states, and the measurement technique holds promise for precision metrology.     

Radiative-capture studies of the giant dipole resonance. Gamma-ray yields from capture of protons and alpha-particles give finer details than studies of gamma-ray absorption

The data on radiative capture through the giant resonance have led to a model in which the capture is pictured as proceeding through a single broad (and therefore short-lived) state that can be called the giant-resonance state. This state is the one formed directly upon capture of a proton, and hence most of the capture radiation is emitted quickly in the direct-interaction mode. Some of the energy that is contained in the giant-resonance state is shared with the more-complicated states of the compound nucleus (that is, with states having many excited nucleons). This sharing, in turn, gives rise to the fine structure that is observed within the giant-resonance envelope. The constant angular distributions that are observed throughout the giant-resonance region support the single-state picture of the giant resonance.     

Spin-torque switching with the giant spin Hall effect of tantalum

Spin currents can apply useful torques in spintronic devices. The spin Hall effect has been proposed as a source of spin current, but its modest strength has limited its usefulness. We report a giant spin Hall effect (SHE) in β-tantalum that generates spin currents intense enough to induce efficient spin-torque switching of ferromagnets at room temperature. We quantify this SHE by three independent methods and demonstrate spin-torque switching of both out-of-plane and in-plane magnetized layers. We furthermore implement a three-terminal device that uses current passing through a tantalum-ferromagnet bilayer to switch a nanomagnet, with a magnetic tunnel junction for read-out. This simple, reliable, and efficient design may eliminate the main obstacles to the development of magnetic memory and nonvolatile spin logic technologies.     

Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect

Radar and optical observations reveal that the continuous increase in the spin rate of near-Earth asteroid (54509) 2000 PH5 can be attributed to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, a torque due to sunlight. The change in spin rate is in reasonable agreement with theoretical predictions for the YORP acceleration of a body with the radar-determined size, shape, and spin state of 2000 PH5. The detection of asteroid spin-up supports the YORP effect as an explanation for the anomalous distribution of spin rates for asteroids under 10 kilometers in diameter and as a binary formation mechanism.     

Observation of the spin Hall effect in semiconductors

Electrically induced electron-spin polarization near the edges of a semiconductor channel was detected and imaged with the use of Kerr rotation microscopy. The polarization is out-of-plane and has opposite sign for the two edges, consistent with the predictions of the spin Hall effect. Measurements of unstrained gallium arsenide and strained indium gallium arsenide samples reveal that strain modifies spin accumulation at zero magnetic field. A weak dependence on crystal orientation for the strained samples suggests that the mechanism is the extrinsic spin Hall effect.     

Past orientation of the lunar spin axis

The orientation of the lunar spin axis is traced from the early history of the earth-moon system to the present day. Tides raised on the earth by the moon have caused an expansion of the lunar orbit. Tides raised on the moon by the earth have de-spun the moon to synchronous rotation and driven its spin axis to a Cassini state-that is, in a coprecessing configuration, coplanar with the lunar orbit normal and the normal to the Laplacian plane (which is at present coincident with the normal to the ecliptic). This combination of events has resulted in a complex history for the lunar spin axis. For much of the period during which its orbital semimajor axis expanded between 30 and 40 earth radii, the obliquity of the moon was of order 25 degrees to 50 degrees . In fact, for a brief period the obliquity periodically attained a value as high as 77 degrees ; that is, the spin axis of the moon was only 13 degrees from lying in its orbit plane.