Semiconductor Terahertz Physics

A rich range of physical phenomena exhibit frequencies in the range of 0.1–10 THz. Within semiconductors, these include phononic, electronic, and mixed modes of oscillations. These fundamental phenomena then serve as the basis for specific devices to produce, manipulate, and detect terahertz radiation.     

The Oxford Handbook of Philosophy of Physics,edited by R. Batterman

There are three ways in which an expected symmetry may not hold exactly: first, if the basic laws do not respect the symmetry exactly; second, if the initial or boundary conditions do not obey the symmetry; and third, by a spontaneous breakdown, which can happen in two ways, here called SBS1 and SBS2, which will be defined and illustrated. Similar to them is the symmetry-breaking approximation, in which a symmetric system is approximated by an asymmetric formalism to make it easier to handle certain correlations.     

Exploring Quantum Physics through Hands-On Projects,by D. Prutchi and S.R. Prutchi

In the last decade there have been extensive advances in the use of sonar systems for the mapping of the sea floor. Different sediment types can now be delineated and displayed in analogue form for subsequent mapping and analysis.

Earlier restrictions on operating depth have been overcome, and acoustic sensors in the side-scan sonar mode can now be used from ships at normal hydrographic survey speeds over the whole Continental Shelf.

Research effort at the University of Bath has led to the development of systems which are now widely used for cable survey problems, and for studying the transport of sediment in coastal waters. The geophysical use of these new techniques is still only at an early stage. With the greatly increased interest now in marine problems and in undersea technology, one may look forward to considerable development in this field of applied physics.     

R值测量及相关物理

工作在北京正负电子对撞机(BEPC)上的北京谱仪(BES)对2—5GeV能区的R值进行了精确测量.这一成果对寻找新物理和新粒子Higgs在国际高能物理界带来巨大冲击.本文对R值测量及相关物理,如μ子反常磁矩α_μ,QED耦合常数α(M_z²),μ子偶素的基态超精细劈裂(HFS)以及确定强耦合常数α_s和重夸克质量等的最新进展和未来展望在实验和理论两方面均作了较详尽的介绍.