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The health risks of the current COVID-19 pandemic, together with the drastic mitigation measures taken in many affected nations, pose an obvious threat to public mental health. The social science literature has already established a clear link between mental health and sociodemographic as well as economic factors, and a growing number of studies investigate the role of biased risk perceptions. To assess this role in the context of COVID-19, this study first implements survey-based measures of over- and underconfidence in the health self-perceptions among Chinese adults during the pandemic. Then, it analyzes their relation to three mental health outcomes: life satisfaction, happiness, and depression (as measured by the CESâˆ'D). We show that the health overconfidence displayed by approximately 30% of the survey respondents is a clear risk factor for mental health problems; it is a statistically significant predictor of depression and low levels of happiness and life satisfaction. We also document that these effects are stronger in regions that experienced higher numbers of confirmed COVID-19 cases and deaths. Recent research has shown that health overconfidence can influence risky behaviors such as smoking and excessive alcohol consumption, which may be particularly detrimental during a pandemic. Our results also offer clear guidelines for the implementation of effective interventions to temper overconfidence, particularly in uncontrollable situations like the COVID-19 pandemic.

While quarantine has become a widely used control measure during the outbreak of the 2019 novel coronavirus disease (COVID-19), empirical research on whether and to what extent quarantine and attitudes towards COVID-19 influence psychological outcomes is scant. Using a cross-sectional online survey, this paper is the first to investigate the heterogeneous impact of quarantine experiences and attitudes towards COVID-19 on the whole distribution of psychological well-being in China. We find that credibility of real-time updates and confidence in the epidemic control are associated with a decline in depression but an increase in happiness. Such effects are stronger in the upper distribution of depression and the median of happiness. We also discern that individuals with severe depressive symptoms (or lower levels of happiness) are more susceptible to the severity of the pandemic. Moreover, home self-quarantine is associated a decrease in depression but an increase in happiness, by contrast, community-level quarantine discourages happiness, especially in the lower distribution of happiness.

Proton beam with energies less than 10 MeV, 1% energy spread, several to tens of pC charge can be stably produced and transported in Compact LAser Plasma Accelerator (CLAPA) at Peking University. The CLAPA beam line is an object-image point analysing system, which ensures the transmission efficiency and energy selection accuracy for proton beams with initial large divergence angle and energy spread. A spread-out Bragg peak (SOBP) is produced with high precision beam control, which is essential for cancer therapy. Other primary application experiments based on laser-accelerated proton beam have also been carried out, such as proton radiograph, stress testing for tungsten, irradiation of semi-conductor sensor to simulate the space irradiation environment and so on., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

Although the strong positive correlation between parental educational expectations (PEE) and child academic achievement is widely documented, little is known about PEE's effects on child psychological outcomes and the mechanisms through which it may work. Hence, in this paper, using nationally representative data from the 2013-2014 and 2014-2015 waves of the China Education Panel Survey, we investigate PEE's causal impact on adolescent subjective well-being (SWB) and the moderating role of the academic pressures that these adolescents perceive. Even though we find robust evidence for a positive causal relation between PEE and adolescent SWB, its moderation by adolescent-perceived academic pressure is negative. In addition, the facts that the benefits of PEE are greater for female adolescents and those from immigrant, one-child, and nonpoor families suggests that it may operate on adolescent SWB through increased family resources, improved family relationships, and higher adolescent aspirations linked to higher PEE.

An AgNP (silver nanoparticle)-deposited bio-based nanostructured carbon aerogel (denoted as p-BC/AgNP) with a three-dimensional (3D) porous network structure was fabricated by carbonizing AgNP bacterial cellulose (denoted as BC/AgNP). The unique 3D nano-network structure gave the hydrophobic p-BC/AgNP good mechanical properties and water reabsorption capacity. AgNPs uniformly dispersed onto the fibers, combining more firmly with fibers after the carbonization process, and no rapid release of Ag+ occurred in an in vitro release test. As an antibacterial material, p-BC/AgNP has an excellent antibacterial effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), for which the inhibition rate was over 99%. Moreover, p-BC/AgNP was good for cell attachment and normal proliferation, which was revealed by fluorescence microscopy, field-emission scanning electron microscopy and an MTT assay in Bel-7402 cells. Because of all the above, p-BC/AgNP might be a desirable antibacterial material that could be used as a new kind of wound dressing, implant, and drug release carrier, and in other biomedical fields.

Comparing with the conventional accelerator, the laser plasma accelerator can accelerate ions more effectively and greatly reduce the scale and cost. A laser accelerator− Compact Laser Plasma Accelerator (CLAPA) is being built at Institute of Heavy Ion physics of Peking University. According to the beam parameters from proof of principle experiments and theoretical simulations, we design the beam line for ions transport which is being built now and in the near future we will carry out experimental study with it. The beam line is mainly constituted by quadrupole and analyzing magnets . The quadrupole triplet lens collects protons generated from the target, while the analyzing magnet system will choose the protons with proper energy. The transport is simulated by program TRACK. The beam line is designed to deliver proton beam with the energy of 1~ 40MeV, energy spread of ±1% and 106-8 protons per pulse to satisfy the requirement of different experiments. The transmission efficiency is about 94% when the energy spread is ±1%., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

We study the enhanced laser ion acceleration using near critical density plasma lens attached to the front of a solid target. The laser quality is spontaneously improved by the plasma lens and energy density of hot electrons is greatly increased by the direct laser acceleration mechanism. Both factors will induce stronger sheath electric field at the rear surface of the target, which accelerates ions to a higher energy. Particle-in-cell simulations show that proton energy can be increased 2-3 times compared with single solid target. This result provides the opportunities for applications of laser plasma accelerator, such as cancer therapy. Further experiments will soon be carried out on 200 TW laser acceleration system at Peking University., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea

A brand new and solely accelerator based on the interaction physics of high intensity ultrafast laser and plasmas, named Compact LAser Plasma Accelerator (CLAPA), was recently built. The laser system can deliver 5J/25fs @ 800nm pulses with contrast of 10⁻¹⁰. Experiments on electron acceleration is scheduled with the regime of laser wakefield acceleration. The charge and the energy spread of the accelerated electron beams will be concerned mainly. The experiments is planned with gas targets with single and dual stages. For the single stage acceleration, we will try density ramp injection and a loose focusing for a monoenergetic electron beam with more charge for some applications. With the PIC simulations and new injection methods, it is expected to generate GeV/tens pC electron beam with an energy spread of, Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea