Infinite number of local conservation laws for the self-dual SU(2) Yang-Mills system within 't Hooft's ansatz

We derive infinite sets of local continuity equations for the four-dimensional classical self-dual SU(2) Yang-Mills fields subjected to 't Hooft's ansatz. In striking analogy to the two-dimensional CP(n) non-linear sigma model where local conservation laws obtain either from complex Cauchy-Riemann analyticity or from a matrix Riccati equation, our local sets derive from quaternionic Fueter analyticity or a Riccati equation associated with the geometric prolongation structure implied by the Belavin-Zakharov linear spectral problem for the self-dual Yang-Mills system. Our analysis underlines the close connection between local and non-local conservation laws and suggests that infinite sets of local continuity equations should be present in the general self-(antiself-)dual gauge field case.     

A study of 't Hooft and Wilson loops

An investigation is undertaken for 't Hooft loop operators in four-dimensional gauge theories. For the first time, a perimeter law is shown to be their behavior in weak coupling Wilson lattice (and continuum) non-abelian SU(N) gauge theories for all N. However, it is also argued that this perimeter law is poor criterion for quark confinement. Rather, it is suggested that non-leading long-distance behavior is what is crucial and relevant in distinguishing non-abelian from abelian (and hence confining from non-confining) theories. A new object, “the 't Hooft line”, is introduced to measure this non-leading behavior and is computed in strong coupling on the lattice. There, one finds magnetic screening characterized by a magnetic screening mass, m_s. It is shown to all orders in strong coupling that m_s is the glueball mass, a result which is expected to persist in weak coupling and in the continuum. Two further consequences of this work are that pure non-abelian gauge theories cannot be in a Higgs phase and that in such models that absence of massless physical particles implies confinement.Finally, non-leading behavior in Wilson loops is examined. The present picture of confinement suggests the absence of van der Waals forces in Yang-Mills theories.     

Zero modes of the 't Hooft-Polyakov monopole

The zero energy eigenvalue problem for quantum fluctuations about the 't Hooft-Polyakov monopole solution is solved explicitly in the Prasad-Sommerfield limit, by exploiting the formal similarity with self-dual euclidean field configurations. The relevance of the results to the spin of the quantized monopole is examined.     

Supersymmetry and functional integration measures

We complete the proof of a recently proposed new characterization of scalar supersymmetric theories and extend this result to “non-scalar” models such as supersymmetric gauge theories. The new characterization does not make use of anticommuting variables since supersymmetry can now be directly understood as a property of certain purely bosonic functional integration measures where all fermionic variables have been “integrated out”.     

新型蓝色荧光材料5,5',6,6'-四苯基-2,2'-联吡嗪的制备和发光性质

以乙二胺和二苯乙二酮为原料合成了5,6-二苯基-2,3-二氢吡嗪(Dpdhpz),Dpdhpz在Ir Cl3·3H2O或三氟化硼乙醚等路易斯酸作用下发生自身氧化偶联得到了5,5',6,6'-四苯基-2,2'-联吡嗪(Dbppz)。在四氢呋喃(THF)溶液中,Dbppz的光致发光(PL)为深蓝色,最大发射峰位于400 nm,CIE坐标为(0.16,0.03)。Dbppz在THF溶液中最大量子效率为89%,在聚苯乙烯薄膜(Dbppz质量分数5%)中的量子效率为78%。将Dbppz制备成器件结构为ITO/HAT-CN(5 nm)/NPB(40 nm)/Dbppz(20 nm)/Tm Py PB(40 nm)/Li F(1 nm)/Al(100 nm)的非掺杂电致发光器件。实验发现,该非掺杂器件并没有产生预期的蓝色发光,而是意外地得到了一个白光器件。我们推测产生白光发射的原因与发光层和空穴传输层之间相互作用有关。由于空穴传输层NPB的芳胺结构具有电子给体性质,而Dbppz的吡嗪结构具有电子受体结构,发光层与空穴传输层的界面发生了电子给体和电子受体的相互作用,形成了激基复合物。在电致发光(EL)光谱中,除了Dbppz发光材料在415 nm的发射外,在550 nm还出现强的激基复合物的发射。激基复合物的产生使得EL发射出现了长波长光谱,同时减弱了发光层的"本征"发光。蓝色"本征"发光与激基复合物的黄色发光构成了一个CIE坐标值为(0.27,0.33)(亮度100 cd/m2)的白光器件。器件最大外量子效率、最大功率效率和最大电流效率分别为44%、0.74 lm/W和1.04 cd/A。     

On the resolvent of Milne's integral equation for a spherical,isotropically-scattering medium

Recently, determination of the resolvent kernel of Milne's integral equation for a spherical, isotropically-scattering medium with internal sources has been made by several authors (cf. Heaslet and Warming;⁽¹⁾Nagirner;⁽²⁾Wilson and Sen⁽³⁾). In this paper, it is shown how to compute the resolvent kernel of the above Milne's equation in terms of the modified Sobolev's Φ-function, which is reduced to the angular integration of the source function in the diffuse radiation field by a finite slab. In other words, once the X- and Y-functions of a slab with twice the optical radius of the sphere have been computed and a Cauchy system for the source function has been solved, the resolvent kernel under consideration can be determined by integration of the modified Sobolev Φ-function.