3,009 research outputs found
Total Nuclear Reaction Cross Section Induced by Halo Nuclei and Stable Nuclei
We develop the method for the calculation of the total reaction cross
sections induced by the halo nuclei and stable nuclei. This approach is based
on the Glauber theory, which is valid for nuclear reactions at high energy. It
is extended for nuclear reactions at low energy and intermediate energy by
including both the quantum correction and Coulomb correction under the
assumption of the effective nuclear density distribution. The calculated
results of the total reaction cross section induced by stable nuclei agree well
with the 30 experimental data within 10 percent accuracy.The comparison between
the numerical results and the 20 experimental data for the total nuclear
reaction cross section induced by the neutron halo nuclei and the proton halo
nuclei indicates a satisfactory agreement after considering the halo structure
of these nuclei, which implies the quite different mean fields for the nuclear
reactions induced by halo nuclei and stable nuclei. The halo nucleon
distributions and the root mean square radii of these nuclei can be extracted
from above comparison based on the improved Glauber model, which indicate
clearly the halo structures of these nuclei. Especially, it is clear to see
that the medium correction of the nucleon-nucleon collision has little effect
on the total reaction cross sections induced by the halo nuclei due to the very
weak binding and the very extended density distribution.Comment: 15 pages,2 figures. Communucations in Theoretical Physics, (2003) in
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IP-Adapter: Text Compatible Image Prompt Adapter for Text-to-Image Diffusion Models
Recent years have witnessed the strong power of large text-to-image diffusion
models for the impressive generative capability to create high-fidelity images.
However, it is very tricky to generate desired images using only text prompt as
it often involves complex prompt engineering. An alternative to text prompt is
image prompt, as the saying goes: "an image is worth a thousand words".
Although existing methods of direct fine-tuning from pretrained models are
effective, they require large computing resources and are not compatible with
other base models, text prompt, and structural controls. In this paper, we
present IP-Adapter, an effective and lightweight adapter to achieve image
prompt capability for the pretrained text-to-image diffusion models. The key
design of our IP-Adapter is decoupled cross-attention mechanism that separates
cross-attention layers for text features and image features. Despite the
simplicity of our method, an IP-Adapter with only 22M parameters can achieve
comparable or even better performance to a fully fine-tuned image prompt model.
As we freeze the pretrained diffusion model, the proposed IP-Adapter can be
generalized not only to other custom models fine-tuned from the same base
model, but also to controllable generation using existing controllable tools.
With the benefit of the decoupled cross-attention strategy, the image prompt
can also work well with the text prompt to achieve multimodal image generation.
The project page is available at \url{https://ip-adapter.github.io}
An Experimental Study of the Water Transfer Through Confined Compacted GMZ Bentonite
International audienceGMZ bentonite has been considered as a possible material for engineered barrier in the Chinese program of nuclear waste disposal at great depth. In the present work, the hydraulic conductivity of this bentonite was determined by simultaneous profile method. A specific infiltration cell equipped with five resistive relative humidity probes was designed for this purpose. The water retention properties were studied under both confined and unconfined conditions; the results shows that at high suctions (> 4 MPa) the water retention capacity is independent of the confining condition, and by contrast, at low suctions (< 4MPa) the confined condition resulted in significant low water retention. Furthermore, the microstructure was investigated at Mercury Intrusion Porosimetry (MIP) and Environmental Scanning Electron Microscope (ESEM) in different states: on oven-dried powder, bentonite slurry, as-compacted and wetted samples. It has been observed that the soil powder is constituted of aggregates of various sizes; this aggregates are destroyed by fully saturation at a water content equal to the liquid limit; compaction at the initial water content of 11-12% and a dry density of 1.7 – 1.75 Mg/m3 led to a microstructure characterized by an dense assembly of relatively well preserved aggregates; saturation of the compacted sample under constant volume condition defined a non-homogeneous microstructure with the presence of well preserved aggregates. This non-homogeneous microstructure would be due to the non uniform distribution of the generated swelling pressure within the soil sample upon wetting. The hydraulic conductivity determined has been found decreasing firstly and then increasing with suction decrease from the initial value of about 80 MPa to zero; the decrease can be attributed to the large pore clogging due to soft gel creation by exfoliation process, as observed at ESEM
Entanglement oscillation and survival induced by non-Markovian decoherence dynamics of entangled squeezed-state
We study the exact decoherence dynamics of the entangled squeezed state of
two single-mode optical fields interacting with two independent and
uncorrelated environments. We analyze in detail the non-Markovian effects on
the entanglement evolution of the initially entangled squeezed state for
different environmental correlation time scales. We find that the environments
have dual actions on the system: backaction and dissipation. In mparticular,
when the environmental correlation time scale is comparable to the time scale
for significant change in the system, the backaction would counteract the
dissipative effect. Interestingly, this results in the survival of some
residual entanglement in the final steady state.Comment: 6 pages, 3 figure
4-(Anthracen-9-yl)-2-phenyl-6-(pyridin-2-yl)pyridine
In the title compound, C30H20N2, the anthracene ring system is approximately planar [maximum deviation = 0.035 (2) Å] and is nearly perpendicular to the central pyridine ring, making a dihedral angle of 75.73 (7)°. The terminal pyridine ring and the phenyl ring are oriented at dihedral angles of 8.11 (10) and 13.22 (10)°, respectively, to the central pyridine ring
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