Accurate Prediction Of Vibronic Levels And Branching Ratios For Laser-coolable Linear Polyatomic Molecules: The Construction Of The Quasidiabatic Hamiltonian

The vibronic structures of the low-lying electronic states in linear polyatomic molecules, which are utilized to construct closed optical cycling, play crucial roles in the laser-cooling processes. The construction of a multi-state K\"oeppel-Domcke-Cederbaum (KDC) quasidiabatic Hamiltonian with spin-orbit coupling, linear vibronic coupling, and Renner-Teller effects taken into account is reported aiming to obtain accurate vibronic levels and wave functions for laser-coolable triatomic molecules. The parameters for this KDC Hamiltonian were obtained from relativistic equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) calculations. Discrete variable representation (DVR) calculations were then carried out to obtain the vibronic levels and wave functions. The accuracy of the present parametrization for the KDC Hamiltonian is demonstrated with calculations for vibronic levels of the $X^2\Sigma$ and $A^2\Pi$ states of the SrOH molecule

MES-Attacks: Software-Controlled Covert Channels based on Mutual Exclusion and Synchronization

Multi-process concurrency is effective in improving program efficiency and maximizing CPU utilization. The correct execution of concurrency is ensured by the mutual exclusion and synchronization mechanism (MESM) that manages the shared hardware and software resources. We propose MES-Attacks, a new set of software-controlled covert channel attacks based on MESM to transmit confidential information. MES-Attacks offer several advantages: 1) the covert channels are constructed at software level and can be deployed on any hardware; 2) closed share of resource ensures the quality of the channels with low interference and makes them hard to be detected; and 3) it utilizes the system's software resources which are abound and hence difficult to isolate. We built covert channels using different MESMs on Windows and Linux, including Event, Timer, FileLockEX, Mutex, Semaphore and flock. Experimental results demonstrate that these covert channels can achieve transmission rate of 13.105 kb/s, 12.383 kb/s, and 6.552 kb/s, respectively in the scenarios of local, cross-sandbox and cross-VM, where the bit error rates are all under 1\%

Intensity-borrowing mechanisms pertinent to laser cooling of linear polyatomic molecules

A study of the intensity-borrowing mechanisms important to optical cycling transitions in laser-coolable polyatomic molecules arising from non-adiabatic coupling, contributions beyond the Franck-Condon approximation, and Fermi resonances is reported. It has been shown to be necessary to include non-adiabatic coupling to obtain computational accuracy that is sufficient to be useful for laser cooling of molecules. The predicted vibronic branching ratios using perturbation theory based on the non-adiabatic mechanisms have been demonstrated to agree well with those obtained from variational discrete variable representation calculations for representative molecules including CaOH, SrOH, and YbOH. The electron-correlation and basis-set effects on the calculated transition properties, including the vibronic coupling constants, the spin-orbit coupling matrix elements, and the transition dipole moments, and on the calculated branching ratios have been thoroughly studied. The vibronic branching ratios predicted using the present methodologies demonstrate that RaOH is a promising radioactive molecule candidate for laser cooling

Government regulation of emergency supplies under the epidemic crisis

This paper constructs a multi-oligopoly model of emergency supplies and analyses the market equilibrium results under normal conditions and epidemic conditions. The impacts of the degree of change in market demand, externalities, the material cost of emergency supplies and government regulation on the equilibrium results, especially on the prices of emergency supplies, are discussed. The results show that an increase in material cost will lead to low output and social welfare and a high price, under either normal conditions or epidemic conditions. Moreover, under epidemic conditions, the degree of change in market demand, externalities, material cost and the presence and mode of government regulation all have multiple and complex influences on the equilibrium results. Under epidemic conditions, both government output and price regulation can increase the supply of emergency supplies. In addition, when market demand changes drastically, consumer surplus and social welfare can be enhanced by the implementation of regulations. Particularly, price regulation is more effective when there is a high material cost

Nonlinear analysis of stress and strain for a clay core rock-fill dam with FEM

AbstractBased on the Duncan-Chang hyperbolic nonlinear elastic material model, this paper carried out the stress and strain numerical analysis of a clay core rock-fill dam, which is a certain building reservoir dam in Yunnan province. By loading on each layer step by step and with the static nonlinear finite element simulation of deposition, it obtained the results of the stress and deformation of the clay core rock-fill dam. The calculation showed that the great difference in deformation modulus causes non-smooth variations in deformation, stress and strain between the transition area and the rock-debris fill. From the analysis it can be seen that the present design of the dam is reasonable since no any abnormal stresses and deformations occurred in the dam. Moreover, this also indicated a feasible and provided a valuable evident for the optimization of cross-section zones in a project