Possible Way to Synthesize Superheavy Element Z=117

Within the framework of the dinuclear system model, the production of superheavy element Z=117 in possible projectile-target combinations is analyzed systematically. The calculated results show that the production cross sections are strongly dependent on the reaction systems. Optimal combinations, corresponding excitation energies and evaporation channels are proposed in this letter, such as the isotopes ^{248,249}Bk in ^{48}Ca induced reactions in 3n evaporation channels and the reactions ^{45}Sc+^{246,248}Cm in 3n and 4n channels, and the system ^{51}V+^{244}Pu in 3n channel.Comment: 10 pages, 4 figures, 1 tabl

Transition of the thermal boundary layer and plume over an isothermal section-triangular roof: An experimental study

The development of thermal boundary layers and plume near a section-triangular roof under different isothermal heating conditions is experimentally investigated using phase-shifting interferometry and thermocouple measurements. The spatially averaged temperature contours are visualized for the Rayleigh number varying from $10^3$ to $4 \times 10^6$. The measurements reveal a flow transition in the steady-state regime from conduction dominance to convection dominance, finally transitioning to a periodic flow regime with an increase in the Rayleigh number. The temperature series of the monitoring points reveal that the flow has a complex bifurcation route containing an inverse period bifurcation and an inverse quasi-periodic bifurcation. The oscillation of the flow depending on the Rayleigh number is also quantitatively and qualitatively described

Environments of Aeolian Deposition in South-Central Nebraska During the Last Glacial Maximum

The Peoria loess of south-central Nebraska, deposited approximately during the last Glacial Maximum, can be subdivided into three zones: an upper laminated loess and a lower massive loess, separated by a dark gley zone in which bison bones and spruce charcoal are found. The lower Peoria unit is characterized by high organic matter content, relatively high bulk density, and common root channels. The upper Peoria unit has rhythmic patterns of two orders: strongly gleyed and weakly gleyed zones alternating in couplets about 2-5 m thick, and coarse- and fine-grained laminae of second order, about 2-4 mm thick. The strongly gleyed zones are relatively low in magnetic susceptibility and contain lenses with abundant fossil plant debris. They may have formed in active zones on top of permafrost during relatively cold and probably moist intervals, with magnetic susceptibility secondarily lowered in the redox environment. Magnetic susceptibility also indicates the possible existence of first-order rhythmic patterns in the lower massive loess. Each of the ten susceptibility oscillations within Peoria loess has a mean duration of about 1000 years, assuming that the loess was deposited between approximately 20,000-22,000 and 10,000-10,500 yr BP. The second-order laminae, close to the expected mean annual accumulation rate of Peoria loess, may be due to seasonal variation in wind intensity or to secondary grain sorting of niveoeolian deposits

Environments of Aeolian Deposition in South-Central Nebraska During the Last Glacial Maximum

The Peoria loess of south-central Nebraska, deposited approximately during the last Glacial Maximum, can be subdivided into three zones: an upper laminated loess and a lower massive loess, separated by a dark gley zone in which bison bones and spruce charcoal are found. The lower Peoria unit is characterized by high organic matter content, relatively high bulk density, and common root channels. The upper Peoria unit has rhythmic patterns of two orders: strongly gleyed and weakly gleyed zones alternating in couplets about 2-5 m thick, and coarse- and fine-grained laminae of second order, about 2-4 mm thick. The strongly gleyed zones are relatively low in magnetic susceptibility and contain lenses with abundant fossil plant debris. They may have formed in active zones on top of permafrost during relatively cold and probably moist intervals, with magnetic susceptibility secondarily lowered in the redox environment. Magnetic susceptibility also indicates the possible existence of first-order rhythmic patterns in the lower massive loess. Each of the ten susceptibility oscillations within Peoria loess has a mean duration of about 1000 years, assuming that the loess was deposited between approximately 20,000-22,000 and 10,000-10,500 yr BP. The second-order laminae, close to the expected mean annual accumulation rate of Peoria loess, may be due to seasonal variation in wind intensity or to secondary grain sorting of niveoeolian deposits

Quantum size effects on the perpendicular upper critical field in ultra-thin lead films

We report the thickness-dependent (in terms of atomic layers) oscillation behavior of the perpendicular upper critical field $H_{c2\perp}$ in the ultra-thin lead films at the reduced temperature ($t=T/T_c$). Distinct oscillations of the normal-state resistivity as a function of film thickness have also been observed. Compared with the $T_c$ oscillation, the $H_{c2\perp}$ shows a considerable large oscillation amplitude and a $\pi$ phase shift. The oscillatory mean free path caused by quantum size effect plays a role in $H_{c2\perp}$ oscillation.Comment: 4 pages, 4 figure