COVID-19 has spread rapidly and internationally, which has elicited public panic and psychological problems. Public protective behaviors and perception play crucial roles in controlling the spread of ...illness and psychological status.
We conducted a cross-sectional online survey in the hardest-hit Hubei province and other areas in China affected by the COVID-19 outbreak. Questions about their basic information, the perception of the COVID-19 outbreak, recent preventive or avoidance behaviors, and self-reported mental health scales including the Patient Health Questionnaire and Self-Rating Anxiety Scale were included. Binary logistic regressions were used to investigate the association between personal variables/perceptions and psychological distress.
A total of 6261 people were included in the analysis, with 3613 (57.7%) in Hubei province (1743 in Wuhan). The majority of people have adopted preventive and avoidance behaviors. People from Hubei, with contact history, and people who were infected or whose family members were infected had a much higher prevalence of depression and anxiety. Providing truthful and sufficient information, informing the public about the severity of the disease, and perceptions that the outbreak can be controlled by protective behaviors were associated with lower prevalence of depression and anxiety.
Assessing the public response, perception, and psychological burden during the outbreak may help improve public health recommendations and deliver timely psychological intervention. Further research may focus on the psychological status of a specialized group to identify methods of delivery of better support based on public response and psychological demand.
To solve the problems such as the dissolution and the poor conductivity of organic small molecule electrode materials, we construct π‐d conjugated coordination polymer Ni‐DHBQ with multiple ...redox‐active centers as lithium storage materials. It exhibits an ultra‐high capacity of 9‐electron transfers, while the π‐d conjugation and the laminar structure inside the crystal ensure fast electron transport and lithium ion diffusion, resulting in excellent rate performance (505.6 mAh g−1 at 1 A g−1 after 300 cycles). The interaction of Ni‐DHBQ with the binder CMC synergistically inhibits its dissolution and anchors the Ni atoms, thus exhibiting excellent cycling stability (650.7 mAh g−1 at 0.1 A g−1 after 100 cycles). This work provides insight into the mechanism of lithium storage in π‐d conjugated coordination polymers and the synergistic effect of CMC, which will contribute to the molecular design and commercial application of organic electrode materials.
The π‐d conjugated coordination polymer Ni‐DHBQ exhibits an ultra‐high lithium storage capacity of 9‐electron transfer and excellent rate performance due to its multiple redox active centers, π‐d conjugation and laminar structure. Meanwhile, the binder CMC, like an octopus, has an appropriate interaction with both the ligand and Ni2+ of Ni‐DHBQ, thus reducing the solubility of Ni‐DHBQ and enhancing its cycle life.
Electromagnetic (EM) absorbers are widely used in military and civilian applications. In this paper, we proposed a low-profile broadband low-frequency absorber based on the microwave network and ...evolution algorithm (EA). The proposed absorber is made of multi-layer magnetic material with an ultra-thin thickness (3.5 mm) and works in a wide band from 1.1 GHz to 5.5 GHz under the criteria of reflection loss (RL) less than -10dB. Experiments are in a good agreement with designs, proving correctness of the design method, and the superior performance of the absorber. The proposed absorber has broad prospects in many practical applications, such as RCS reduction and EM compatibility.
Most P2‐type layered oxides exhibit a large volume change when they are charged into high voltage, and it further leads to bad structural stability. In fact, high voltage is not the reason which ...causes the irreversible phase transition. There are two internal factors which affect structural evolution: the amount and distribution of Na ions retained in the lattice. Hereon, a series of layered oxides Na2/3MnxNix−1/3Co4/3−2xO2 (1/3≤x≤2/3) were synthesized. It is observed that different components have different structural evolutions during the charge/discharge processes, and further researches find that the distribution of Na ions in layers is the main factor. By controlling the distribution of Na ions, the phase transition process can be well controlled. As the referential component, P2‐Na2/3Mn1/2Ni1/6Co1/3O2 cathode with uniform distribution of Na ions is cycled at the voltage window of 1.5–4.5 V, which exhibits a volume change as low as 1.9 %. Such a low strain is beneficial for cycling stability. The current work provides a new and effective route to regulate the structural evolution of the promising P2‐type layered cathode for sodium ion batteries.
The number and distribution of Na ions retained in lattice are two internal factors which affect structural evolution. Na ions can support the lattice structure like pillars, by regulating the distribution of Na ions, the process of phase transition can be controlled. As a result, the cathode can offer as high capacity as possible without obvious phase transition.
As independent system operators (ISOs) or regional transmission organizations (RTOs) grow in size, the Security Constrained Unit Commitment (SCUC) currently in use encounters significant ...difficulties, including issues related to modeling precision and computational complexity. To overcome these challenges, we have developed a feasibility detection-based induced objective function method to solve SCUC, which is an integer programming heuristics based on induced functions and variable fixing. Experimental results demonstrate that the proposed method outperforms CPLEX on large-scale datasets.
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