Comparison of Vlasov-Uehling-Uhlenbeck model with 4 π Heavy Ion Data

Streamer chamber data for collisions of Ar + KCl and Ar + BaI2 at 1.2 GeV/nucleon are compared with microscopic model predictions based on the Vlasov-Uehling-Uhlenbeck equation, for various density-dependent nuclear equations of state. Multiplicity distributions and inclusive rapidity and transverse momentum spectra are in good agreement. Rapidity spectra show evidence of being useful in determining whether the model uses the correct cross sections for binary collisions in the nuclear medium, and whether momentum-dependent interactions are correctly incorporated. Sideward flow results do not favor the same nuclear stiffness parameter at all multiplicities

On the complexity of trial and error for constraint satisfaction problems

In 2013 Bei, Chen and Zhang introduced a trial and error model of computing, and applied to some constraint satisfaction problems. In this model the input is hidden by an oracle which, for a candidate assignment, reveals some information about a violated constraint if the assignment is not satisfying. In this paper we initiate a systematic study of constraint satisfaction problems in the trial and error model, by adopting a formal framework for CSPs, and defining several types of revealing oracles. Our main contribution is to develop a transfer theorem for each type of the revealing oracle. To any hidden CSP with a specific type of revealing Oracle, the transfer theorem associates another CSP in the normal setting, such that their complexities are polynomial-time equivalent. This in principle transfers the study of a large class of hidden CSPs to the study of normal CSPs. We apply the transfer theorems to get polynomial-time algorithms or hardness results for several families of concrete problems. (C) 2017 Elsevier Inc. All rights reserved

Comparisons of VUU (Vlasov-Uehling-Uhlenbeck) predictions with streamer chamber data

Experimental charged particle inclusive and exclusive parameters for several nuclear systems are compared with microscopic model predictions based on the Vlasov-Uehling-Uhlenbeck equation, for various density-dependent nuclear equations of state (EOS). Inclusive variables and multiplicity distributions are in good agreement, and are not sensitive to the EOS. Rapidity spectra show evidence of being useful in determining whether the model uses the correct sections for binary collisions in the nuclear medium, and whether momentum dependent interactions are correctly incorporated. Sideward flow parameters do not favor the same nuclear incompressibility at all multiplicities, and there are indications that the present model may provide only an upper limit on the true stiffness of the EOS. Findings relating to impact parameter averaging and the mass and energy dependence of transverse flow are also presented. 24 refs., 6 figs., 1 tab

4D-Printed Dynamic Materials in Biomedical Applications: Chemistry, Challenges, and Their Future Perspectives in the Clinical Sector

Most of the biomedical materials printed using 3D bioprinting are static and are unable to alter/transform with dynamic changes in the internal environment of the body. The emergence of four-dimensional (4D) printing addresses this problem. By preprogramming dynamic polymer materials and their nanocomposites, 4D printing is able to produce the desired shapes or transform functions under specific conditions or stimuli to better adapt to the surrounding environment. In this review, the current and potential applications of 4D-printed materials are introduced in different aspects of the biomedical field, e.g., tissue engineering, drug delivery, and sensors. In addition, the existing limitations and possible solutions are discussed. Finally, the current limitations of 4D-printed materials along with their future perspective are presented to provide a basis for future research