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Different combinations of normalizing and tempering were carried out to optimize the microstructure and enhance the high-temperature mechanical properties of HRB400FR fire-resistant steel bars. The results showed that with the increasing of the tempering temperature from 400 to 600°C, the steel bar’s hardness decreases linearly, mainly due to the formation of quasi-polygon ferrite and granular bainite. Besides, the reduced width and the dissolution of the lath bainite also undermine the performance of the tempered steel bars. The highest Vickers hardness of 380 HV is achieved when the steel is normalized at 950°C and then tempered at 400°C, mainly due to precipitation strengthening and bainite strengthening. The hardness of the test steel tempered at 600°C gives the lowest value, only 230 HV since the least amount of bainite is obtained. When the tempering temperature reaches 650°C, the hardness rises to 260 HV due to the formation of the lath bainite. The emergence of needle bainite generally reduces the matrix grain size, and the appearance of lath martensite refines the precipitated carbides.

A series of crosslinked poly(norbornene)-based composite anion exchange membranes, PHMNHD@CN-X, with different graphitized carbon nitride (g-C3N4) contents were prepared by synthesizing new norbornene-like monomers and using g-C3N4as filler. These membranes were utilized for CO2reduction reaction (CO2RR). The analysis indicates that PHMNHD@CN-1, a composite membrane containing 1% g-C3N4, has a hydroxide conductivity of 51.29 mS cm−1, which is significantly higher than the hydroxide conductivity of the commercial membrane called Sustainion Grade RT, which is 30.88 mS cm−1. Meanwhile, the anion exchange membrane with filler modification, PHMNHD@CN-1, demonstrated superior electrolytic performance in a homemade membrane electrode assembly (MEA) electrolyzer, achieving a current density of 83.89 mA cm−2at the cell voltage of 3 V. At current densities of 100 to 130 mA cm−2, PHMNHD@CN-1 displayed a higher CO Faraday efficiency (FECO%) of 92.41%. These results suggest that the modified anion exchange membrane has a promising potential for CO2RR.

By using 10 years of Challenging Minisatellite Payload satellite observations, we investigate the average conditions of the interplanetary magnetic field (IMF) prevailing during the westward counter equatorial electrojet (CEJ). Equally, we compared the average IMF conditions accompanying high‐latitude field‐aligned currents of the Region 1 (R1) and Region 2 (R2). It shows that both CEJ and high‐latitude field‐aligned currents events when R2 is greater than R1 tend to happen preferably during the northward turning of the IMF Bz and the substorm recovery phase. Sunlight has an important influence on the longitudinal distribution of the equatorial electrojet (EEJ), and the effect is opposite to the tidal electric field at Eregion. The anticorrelation between cos 0.5(SZA) (solar zenith angle effect) average values during CEJ events and EEJ intensity is most prominent around June solstice. By using combined measurements from Challenging Minisatellite Payload and DMSP satellites, it is found that before the occurrence and in the initial phase of a subauroral polarization stream the EEJ gets enhanced, and after about 30 min it reduces in intensity. The CEJ occurrence rate more than doubles during subauroral polarization stream periods compared to normal conditions. Both counter electrojet and R2 > R1 field‐aligned currents occur during the northward turning of the interplanetary magnetic fieldThe counter electrojet occurrence rate more than doubles during subauroral polarization stream periods than under normal conditionsThere is an anticorrelation between cos 0.5(SZA) (solar zenith angle) and eastward electrojet, most prominent around June solstice

Using the in situ measurements of ROCSAT‐1 satellite during 181 geomagnetic storms happened from July 1999 to June 2004, a superposed epoch analysis of the equatorial plasma depletions (EPDs) occurrence is conducted. At postsunset hours (1800–2200 LT), the EPDs occurrence is enhanced shortly at the storm onset, but afterward, a long‐last suppression dominates. The EPDs occurrence at Midnight (2200–0200 LT) generally shares a similar pattern to that at postsunset hours. The occurrence at predawn (0200–0400) gradual increases near storm onset and reach its maximum at 6–9 hr and decays until 18 hr. For a given longitude at postsunset/midnight, the EPDs occurrence tends to be suppressed or promoted when the EPDs do or do not prevail. The disturbed vertical plasma drift generally determines the inhibition/promotion of the EPDs occurrence at postsunset/predawn. However, for predawn EPDs occurrence, the plasma vertical drift cannot well explain the longitudinal variation. The continuous observations from consecutive orbits of ROCSAT‐1 are carefully compared and the result suggests that the geomagnetic storm‐induced additional predawn EPDs are preferred to be the longer‐lived developed EPDs rather than fresh EPDs. In addition, a possible mechanism concerning the background plasma density enhancement which might be related with the energetic electrons induced nighttime ionization is proposed. The EPDs occurrence during 181 geomagnetic storms is statistically investigated via a superposed epoch analysis, for different season and local timesPostsunset EPDs occurrence tends to be suppressed/enhanced at longitudes where the EPD normally prevails globally, except that at mid‐Asia during June SolsticeThe storm‐induced EPDs at predawn sector is more related to the fossil ones rather than fresh ones

ABSTRACTThe development of a successful vaccine, which should elicit a combination of humoral and cellular responses to control or prevent infections, is the first step in protecting against infectious diseases. A vaccine may protect against bacterial, fungal, parasitic, or viral infections in animal models, but to be effective in humans there are some issues that should be considered, such as the adjuvant, the route of vaccination, and the antigen-carrier system. While almost all licensed vaccines are injected such that inoculation is by far the most commonly used method, injection has several potential disadvantages, including pain, cross contamination, needlestick injury, under- or overdosing, and increased cost. It is also problematic for patients from rural areas of developing countries, who must travel to a hospital for vaccine administration. Noninvasive immunizations, including oral, intranasal, and transcutaneous administration of vaccines, can reduce or eliminate pain, reduce the cost of vaccinations, and increase their safety. Several preclinical and clinical studies as well as experience with licensed vaccines have demonstrated that noninvasive vaccine immunization activates cellular and humoral immunity, which protect against pathogen infections. Here we review the development of noninvasive immunization with vaccines based on live attenuated virus, recombinant adenovirus, inactivated virus, viral subunits, virus-like particles, DNA, RNA, and antigen expression in rice in preclinical and clinical studies. We predict that noninvasive vaccine administration will be more widely applied in the clinic in the near future.

AbstractObjectives:Telemedicine enables patients to communicate with physicians effectively, especially during the coronavirus disease (COVID-19) pandemic. However, few studies have explored the use of online health care platforms for a comprehensive range of specialties during the COVID-19 pandemic. This study aimed to investigate how telemedicine services were affected by the announcement of human-to-human transmission in China.Methods:Telemedicine data from haodf.com in China were collected. A difference-in-differences analysis compared the number of telemedicine use and the number of active online physicians for different specialties in 2020 with the numbers in 2019, before and after the announcement of human-to-human transmission.Results:Data from 2 473 734 telemedicine use during the same calendar time in 2020 and 2019 were collected. Telemedicine use in 2020 increased by 349.9% after the announcement of human-to-human transmission in China, and the number of active online physicians increased by 23.2%. The difference-in-differences analysis indicated that the announcement had statistically significant positive effects on the numbers of telemedicine use for almost all specialties, except cosmetic dermatology, pathology, occupational diseases, sports medicine, burn, medical imaging, and interventional medicine.Conclusion:Telemedicine services increased significantly after the announcement of human-to-human transmission of COVID-19. Online activities of most specialties increased, except where providers had to conduct in-person testing and provide bedside therapies.

This study examines the impact of coronavirus disease 2019 (COVID-19) test accuracy (i.e., sensitivity and specificity) on the progression of the pandemic under two scenarios of limited and unlimited test capacity. We extend the classic susceptible– exposed–infectious–recovered model to incorporate test accuracy and compare the progression of the pandemic under various sensitivities and specificities. We find that high-sensitivity tests effectively reduce the total number of infections only with sufficient testing capacity. Nevertheless, with limited test capacity and a relatively high cross-infection rate, the total number of infected cases may increase when sensitivity is above a certain threshold. Despite the potential for higher sensitivity tests to identify more infected individuals, more false positive cases occur, which wastes limited testing capacity, slowing down the detection of infected cases. Our findings reveal that improving test sensitivity alone does not always lead to effective pandemic control, indicating that policymakers should balance the trade-off between high sensitivity and high false positive rates when designing containment measures for infectious diseases, such as COVID-19, particularly when navigating limited test capacity.

It is generally believed that three-dimensional (3D) echocardiography can provide unique en face views of atrial septal defects (ASDs), whereas conventional two-dimensional (2D) transthoracic echocardiography (TTE) cannot. The purpose of this study was to develop a special 2D TTE–based en face view of ASDs.

The dynamic evolution of the double tongue of ionization (TOI) into a single TOI at 400 km altitude during the geomagnetic storm on September 7, 2015 was studied using the Defense Meteorological Satellite Program observations and Thermosphere Ionosphere Electrodynamic General Circulation model simulations. The double TOIs occurred in the presence of increased southward Bzand weak positive By, while the single TOI occurred in the presence of northward turning of Bzand duskward turning of By. In both double and single TOI events, the plasma at middle latitudes in the afternoon (prenoon) sector was greatly enhanced due to the local upward (upward) and zonal (meridional) E × B drift. The transition process is due to both the northward and duskward turning of interplanetary magnetic field (IMF). The northward turning of IMF Bzweakens the storm enhanced density (SED) and the TOI in both afternoon and morning sectors, while the increasing duskward IMF Bystrengthens the morning TOI. A tongue of ionization (TOI) is a persistent “tongue”‐like structure of electron density enhancement at high latitudes and usually elongates in the noon‐midnight direction, which is a hot topic in the field of magnetosphere‐ionosphere coupling. However, previous studies mainly focused on the formation and evolution of single TOI events. The dynamic evolution from double TOIs to single TOI events has never been reported, which is an important topic in understanding the dynamics of the magnetosphere‐ionosphere coupled system. Our work suggests that the temporal variations of interplanetary magnetic field Byand Bzcontrol the transition by regulating polar ionosphere convection. Obvious storm enhanced density (SEDs) occurred in the prenoon and afternoon sectors for both double and single tongue of ionization (TOI) eventsThe prenoon SED was caused by both upward and meridional E × B driftsThe increasing duskward interplanetary magnetic field (IMF) By and northward turning of IMF Bzaccounted for the transition from the double TOI to the single TOI Obvious storm enhanced density (SEDs) occurred in the prenoon and afternoon sectors for both double and single tongue of ionization (TOI) events The prenoon SED was caused by both upward and meridional E × B drifts The increasing duskward interplanetary magnetic field (IMF) By and northward turning of IMF Bzaccounted for the transition from the double TOI to the single TOI

In this study, equatorial electrojets (EEJs) simulated by the Thermosphere‐Ionosphere Electrodynamics General Circulation Model (TIE‐GCM) were compared with those observed by ground‐based magnetometers and the Challenging Minisatellite Payload (CHAMP) satellite. Simulations were performed with or without nonmigrating tidal forcing at the lower boundary and in the frame of the International Geomagnetic Reference Field (IGRF) or dipole field. The model forced by the nonmigrating tides could qualitatively reproduce the local time and longitudinal variation of an EEJ in the frame of the IGRF with accuracy. The tides were important in causing the later local time occurrence of the EEJ peak in the Peruvian sector, and they favored the occurrence of the morning counterelectrojet (CEJ) in the frame of the IGRF. The difference in the EEJ peak intensity between the Peruvian and Indian stations was enhanced due to the tidal effect. The net effect of the tides on the two‐station difference was almost doubled in the dipole field compared with that in the IGRF. The TIE‐GCM with a tidal input could reproduce a Wavenumber‐4 longitudinal structure of the noontime EEJ, but it underestimated the peak EEJ in the East Asia sector. The magnetically eastward electric field and the neutral zonal wind at noontime in the Eregion in the TIE‐GCM were both weak in the East Asia sector. This model‐data discrepancy was at least partly due to insufficient lower boundary forcing in this longitudinal sector. Nonmigrating tides can shift a peak equatorial electrojet to a later local time in a realistic geomagnetic field geometryNonmigrating tides are important for the occurrence of a morning counterelectrojet in a realistic geomagnetic field geometryThe difference in the EEJ peak intensities between Peruvian and Indian stations could be enhanced by the nonmigrating tidal forcing