Interaction of Turbulent Coherent Structures and Small Scale Structures

In lhis paper experimental research is carried out for the existence of larqe andsmall scale .structures in turbulent boundary layer and the interactions between these structures. Based on the experimental results ,a new cethod is suggested io (iescribethe coherent strucures in which the interactions between between the coherent and small-scale slructures are considered ,Using this method a new pattern recognition method is and rough wall conditions. The results show that the suggested method is reasonable .

Evolution of Small Scale Density Perturbations of Plasma and Charged Aerosol Particles in Polar Mesospheric Summer Echoes (PMSE) Layers

Time evolution of ionospheric D-region plasmas including the perturbations of electrons and charged aerosol particles is investigated under the conditions of polar mesosphere summer echoes （PMSE）. It is shown that the time scale of decay of the electron density is in the order of an hour under typical PMSE conditions, in the majority of cases, the electron density is anticorrelated to the ion density, except that the radius of aerosol particles is greater than 50 nm. Also, the evolutions under varied parameters, such as the amplitude and width of perturbation, the aerosol particle radius, and the altitude of the PMSE occurrence are investigated. The obtained results are useful for interpreting the experimental observations.

Failure mechanism and control technology of water-immersed roadway in high-stress and soft rock in a deep mine

Aiming at soft rock ground support issues under conditions of high stress and long-term water immersion, the ground failure mechanism is revealed by taking the deep-water sumps of Jiulong Mine as the engineering background and employing field investigation, tests of rock structure, mechanical properties and mineral composition. The main factors leading to the surrounding rock failure include the high and complex stress state of the water sumps, high-clay content and water-weakened rock, and the unreasonable support design. In this paper, the broken and fractured rock mass near roadway opening is considered as ground small-structure, and deep stable rock mass as ground large-structure. A support technology focusing on cutting off the water, strengthening the small structure of the rock and transferring the large structure of the rock is proposed. The proposed support technology of interconnecting the large and small structures, based on high-strength bolts, high-stiffness shotcrete layer plugging water,strengthening the small structure with deep-hole grouting and shallow-hole grouting, highpretensioned cables tensioned twice to make the large and small structures bearing the pressure evenly,channel-steel and high-pretensioned cables are used to control floor heave. The numerical simulation and field test show that this support system can control the rock deformation of the water sumps and provide technical support to similar roadway support designs.

A NEW STRUCTURE OF SMALL INTENSELY FLUORESCENT CELLS IN SUPERIOR MESENTERIC GANGLION OF HUMAN FETUS

Superior mesenteric ganglia of six fetuses (35-40 weeks old) were investigated by histochemical fluorescent method. In addition to solitary SIF cells and clusters of SIF cells reported previously, a new structure of SIF cells was found and named ''SIF-cell nodule''. The SIF-cell nodule was composed of a large number of SIF cells and was encapsulated by dense connective tissue. Some blood vessels and nerve fibers entered the nodule. Based on the morphology, we speculated that SIF-cell nodule might be an endocrine gland.

Simultaneous structure and luminescence property control of barium carbonate nanocrystals through small amount of lanthanide doping

Rare earth doping has been widely applied in many functional nanomaterials with desirable properties and functions,which would have a significant effect on the growth process of the materials.However,the controlling strategy is limited into high concentration of lanthanide doping,which produces concentration quenching of the lanthanide ion luminescence with an increase in the Ln^(3+)concentration,resulting in lowering the fluorescence quantum yield of lanthanide ion.Herein,for the first time,we demonstrate simultaneous control of the structures and luminescence properties of BaCO_3nanocrystals via a small amount of Tb^(3+)doping strategy.In fact,Tb^(3+)would partially occupy Ba^(2+)sites,resulting in the changes to the structures of the BaCO_3nanocrystals,which is primarily determined by charge modulation,including the contributions from the surfaces of crystal nuclei and building blocks.These structurally modified nanocrystals exhibit tunable luminescence properties,thus emerging as potential candidates for photonic devices such as light-emitting diodes and color displays.

D-A structural protean small molecule donor materials for solution-processed organic solar cells

Under the synergistic effect of molecular design and devices engineering, small molecular organic solar cells have presented an unstoppable tendency for rapid development with putting forward donor- acceptor （D-A） structures. Up to now, the highest power conversion efficiency of small molecules has exceeded 11%, comparable to that of polymers. In this review, we summarize the high performance small molecule donors in various classes of typical donor-acceptor （D-A） structures and discuss their relationships briefly.

PandaX limits on the light dark matter with a light mediator in the singlet extension of MSSM

Using the latest PandaX limits on the light dark matter(DM) with a light mediator, we check their implication on the parameter space of the general singlet extension of MSSM(without Z3 symmetry), which can have a sufficient DM self-interaction to solve the small-scale structure problem. We find that the PandaX limits can tightly constrain the parameter space, depending on the coupling λ between the singlet and doublet Higgs fields. For the singlet extension of MSSM with Z3 symmetry, the so-called NMSSM, we also demonstrate the PandaX constraints on its parameter space, which gives a light DM with the correct relic density but without sufficient self-interaction to solve the small-scale structure problem. We find that in NMSSM, the GeV dark matter with a sub-GeV mediator is tightly constrained.