Assessment of density functional methods with correct asymptotic behavior

Long-range corrected (LC) hybrid functionals and asymptotically corrected (AC) model potentials are two distinct density functional methods with correct asymptotic behavior. They are known to be accurate for properties that are sensitive to the asymptote of the exchange-correlation potential, such as the highest occupied molecular orbital energies and Rydberg excitation energies of molecules. To provide a comprehensive comparison, we investigate the performance of the two schemes and others on a very wide range of applications, including the asymptote problems, self-interaction-error problems, energy-gap problems, charge-transfer problems, and many others. The LC hybrid scheme is shown to consistently outperform the AC model potential scheme. In addition, to be consistent with the molecules collected in the IP131 database [Y.-S. Lin, C.-W. Tsai, G.-D. Li, and J.-D. Chai, J. Chem. Phys., 2012, 136, 154109], we expand the EA115 and FG115 databases to include, respectively, the vertical electron affinities and fundamental gaps of the additional 16 molecules, and develop a new database AE113 (113 atomization energies), consisting of accurate reference values for the atomization energies of the 113 molecules in IP131. These databases will be useful for assessing the accuracy of density functional methods.Comment: accepted for publication in Phys. Chem. Chem. Phys., 46 pages, 4 figures, supplementary material include

Developing Sustainable Snow Sports Education Programs for Adolescent Participation

Following Beijing’s winning bid to host the 2022 Winter Olympic Games, winter sports have ushered in a great development opportunity for adolescents in China. Beijing initiated the Ice and Snow Sports on Campus Program in 2016, however, one of the challenges is that the lack of quality snow sports instructors and access to ski resorts is limiting sustainable programs. Greek Peak Ski Resort, located in upstate NY, has a successful history of running snow sport educational programs that Beijing may be able to learn from. The purpose of this study was to assess and compare the Ice and Snow Sports on Campus Program in Beijing with the snow sports programs at Greek Peak Ski Resort, having a goal to explore sustainable education programs for adolescents. Literature research, program reports, field observation, and interviews with program directors and experts were used in this study to assess and compare the programs in Beijing and Greek Peak Ski Resort. The findings indicated that with the Ice and Snow Sports on Campus Program initiated in 2016 by the Beijing Municipal Education Commission, about 2.1 million K-12 students’ participation counts in ice and snow sports have been recorded. In 2021, more than 200 K-12 schools with ice and snow sports specialties were certified in Beijing. A total of 60 model courses with the topic in winter sports and Olympics have been developed to improve ice and snow sports teaching. The strong and historical school skiing program at Greek Peak Ski Resort includes about 55-57 K-12 school programs and 5 college PE programs each year, with an estimated student participation count of 20,000 per year. The collaboration between Greek Peak Ski Resort and local schools/ colleges/universities offers sustainable educational programs, benefitting generations of students and all parties involved and efficiently sharing resources. The 2022 Beijing Winter Olympics provides a rare historical opportunity for multi-level and multi-dimensional cooperation between the sports and educational departments in Beijing. With supporting policies and guidance, the strategic goal of cultivating more young people to participate in winter sports is being achieved. Education programs provide opportunities for adolescents to learn winter sports skills and promote active healthy behavior. The collaboration between local schools, colleges/universities and Greek Peak Resort can be a good solution for Beijing to resolve the critical challenge of lack of quality instructors and easy access to winter sports facilities

Foreign Object Damage to Fan Rotor Blades of Aeroengine Part I: Experimental Study of Bird Impact

AbstractThe conditions of experiment for bird impact to blades have been improved. The experiment of bird impact to the fan rotor blades of an aeroengine is carried out. Through analyzing the transient state response of blades impacted by bird and the change of blade profile before and after the impact, the anti-bird impact performance of blades in the first fan rotor is verified. The basis of anti-foreign object damage design for the fan rotor blades of an aeroengine is provided

Foreign Object Damage to Fan Rotor Blades of Aeroengine Part II: Numerical Simulation of Bird Impact

AbstractBird impact is one of the most dangerous threats to flight safety. The consequences of bird impact can be severe and, therefore, the aircraft components have to be certified for a proven level of bird impact resistance before being put into service. The fan rotor blades of aeroengine are the components being easily impacted by birds. It is necessary to ensure that the fan rotor blades should have adequate resistance against the bird impact, to reduce the flying accidents caused by bird impacts. Using the contacting-impacting algorithm, the numerical simulation is carried out to simulate bird impact. A three-blade computational model is set up for the fan rotor blade having shrouds. The transient response curves of the points corresponding to measured points in experiments, displacements and equivalent stresses on the blades are obtained during the simulation. From the comparison of the transient response curves obtained from numerical simulation with that obtained from experiments, it can be found that the variations in measured points and the corresponding points of simulation are basically the same. The deforming process, the maximum displacements and the maximum equivalent stresses on blades are analyzed. The numerical simulation verifies and complements the experiment results

The Dark Side of Images: Effect of Customer Generated Images on Product Assessment

Customer Generated Image (CGI) on e-commerce platforms has been widely recognized as a marketing tool to persuade customers into purchases. Despite its persuasive power, the effect of CGI on post purchase satisfaction has seldom been examined. This study draws upon Elaboration Likelihood Model and proposes that the affective cues in CGI could distract consumer’s cognitive information processing and lead to unsatisfactory purchases with a larger probability. To empirically test our hypothesis, we employed a difference-in-differences model with propensity score weighting method and deep learning based face detection algorithm and found that CGI could cause subsequent review ratings 0.12 stars lower compared with those not exposed to CGI. Additional analysis indicated that this negative effect could be attenuated if the CGI contains human faces or the image review has a low rating. These findings have important implications for online platforms to better leverage user generated rich media content