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"Huan Liu"
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Electronic differential control based on speed and optimum slip ratio estimation for all-electric vehicles with in-wheel motors
Vehicle 2-degree of freedom (DOF) kinematic and dynamic models are derived. The former, which uses fixed parameters, is often used for speed-based electronic differential control, but this method does not yield accurate results under varying running situations. In contrast, the latter, which depends on the tire adhesion limit to produce tire saturation force, is typically adopted for torque-based electronic differential control. However, this method also faces many difficulties in real-time implementation, and its theoretical maturity is not strong. To combine the advantages of speed-based electronic differential control and torque-based electronic differential control, this paper focuses on speed and optimum slip ratio as key factors. Additionally, to address the difficulties associated with nonlinear modeling by leveraging the simplicity of linear modeling in design and implementation, this study presents an electronic differential control based on speed and optimum slip ratio estimation for all-electric vehicles with in-wheel motors. It aims to maintain the maneuvering ability of the driver at the maximum adhesion limit. Even when the two driving wheels are subjected to uneven external disturbances from the road surface, they maintain a synchronous speed when driving on a straight line or a differential speed when turning. Simulation validation confirms that the proposed method enhances safety for in-wheel motor electric vehicles in urban scenarios involving adverse weather conditions (e.g., rain, snow, ice) and aggressive lane-changing maneuvers. Experimental validation confirms the static performance of the motor controller and the differential control capability of the two drive wheels. These findings lay a foundation for improving extreme-condition adaptability through three future directions: adaptive tire dynamics integration, hierarchical energy-stability control architectures, and real-time deployment validated via hardware-in-the-loop testing.
Journal Article
Official social media and its impact on public behavior during the first wave of COVID-19 in China
Background
During the COVID-19 pandemic, official social media became a critical channel for the public to obtain pandemic information. No matter the positive function or negative effect of information dissemination, it involves the public’s risk perception and behavior. This study was designed to contribute to the existing research on how official social media information quality (IQ) and risk perception (RP) affect preventive behavior (PB) and continued use behavior (CB) of official social media during the first wave of COVID-19.
Methods
The required data were extracted from a national online survey of the Chinese Mainland during March 24–30 2020, a random sample was asked to participate in the survey (n = 666). Data analysis was performed using regression analysis, structural equation modeling, mediating effect analysis, and one-way ANOVA analysis.
Results
The results show that IQ (10.010 ± 3.568) has direct and indirect positive impact on PB (9.475 ± 3.571), and has a low significant positive indirect impact on CB (3.739 ± 1.566). The IQ has a significant positive impact on RP (β = 0.548), which show that there is no “risk perception paradox” in COVID-19. Furth more, this study also provides new evidence indicating that RP mediates the relationship between IQ and PB. According to the region, gender, age and annual income, and there are significant differences in PB and CB.
Conclusion
The study findings have remarkable implications for improving the information quality and public behaviors. Too high or too low level of risk perception is not conducive to pandemic prevention and control. Official social media should indirectly affect information flow through the reasonable supply of pandemic information and constantly improve the quality of pandemic information to avoid public’s undue panic and excessive health concerns during this ongoing outbreak and subsequent national public emergency events.
Journal Article
Determining the effect of air quality on activities of daily living disability: using tracking survey data from 122 cities in China
Background
Current research on activities of daily living (ADLs) disability has mostly focused on the analysis of demographic characteristics, while research on the microcharacteristics of individuals and the macroenvironment is relatively limited, and these studies solely concern the impact of air quality on individual health.
Methods
This study innovatively investigated the impact of air quality on ADL disability by matching micro data of individuals from the China Health and Retirement Longitudinal Study with data of urban environmental quality from 122 cities. In this study, an ordered panel logit model was adopted for the benchmark test, and the two-stage ordered probit model with IV was used for endogenous treatment.
Results
This innovative study investigated the impact of air quality on ADL disability by matching individual micro data from the China Health and Retirement Longitudinal Study with urban environmental quality data for 122 cities. The results showed that air quality significantly increased the probability of ADL disability. The positive and marginal effect of air quality on moderate and mild disability was higher. Generally, the marginal effect of air quality on residents’ health was negative. In terms of group heterogeneity, the ADL disability of individuals aged over 60 years, those in the high Gross Domestic Product (GDP) group, females, and those in the nonpilot long-term care insurance group was more affected by air quality, and the interaction between air quality and serious illness showed that the deterioration of air quality exacerbated the ADL disability caused by serious illness; that is, the moderating effect was significant.
Conclusions
According to the equilibrium condition of the individual health production function, the ADL disability caused by a 1% improvement in air quality is equivalent to the ADL disability caused by an 89.9652% reduction in serious illness, indicating that the effect of improved air quality is difficult to replace by any other method. Therefore, good air quality can not only reduce ADL disability directly but also reduce serious illness indirectly, which is equivalent to the reduction of ADL disability. This is called the health impact.
Journal Article
Large thermoelectric power factor from crystal symmetry-protected non-bonding orbital in half-Heuslers
Modern society relies on high charge mobility for efficient energy production and fast information technologies. The power factor of a material—the combination of electrical conductivity and Seebeck coefficient—measures its ability to extract electrical power from temperature differences. Recent advancements in thermoelectric materials have achieved enhanced Seebeck coefficient by manipulating the electronic band structure. However, this approach generally applies at relatively low conductivities, preventing the realization of exceptionally high-power factors. In contrast, half-Heusler semiconductors have been shown to break through that barrier in a way that could not be explained. Here, we show that symmetry-protected orbital interactions can steer electron–acoustic phonon interactions towards high mobility. This high-mobility regime enables large power factors in half-Heuslers, well above the maximum measured values. We anticipate that our understanding will spark new routes to search for better thermoelectric materials, and to discover high electron mobility semiconductors for electronic and photonic applications.
The intrinsic origin of high-power factors observed in half-Heusler alloys remains elusive, limiting the design of new thermoelectric materials. In this work, the authors reveal it is due to weakened electron–acoustic phonon coupling, originating from crystal symmetry protection of non-bonding orbitals.
Journal Article
Formal and Informal Care: Complementary or Substitutes in Care for Elderly People? Empirical Evidence From China
To integrate the care resources of the elderly, while promoting the development of formal social care resources, some countries have gradually turned to the development of family informal care resources. In China, informal family care has a more important role, whereas social formal care resources are far from meeting the needs of older people. Thus, this strategy can only be effective if there is a clear complementary relationship between informal care and formal care. Empirical analysis is selected from the China Health and Nutrition Survey (CHNS) database, which conducted 10 follow-up surveys in 12 provinces and municipalities in China. A two-tier stochastic frontier (TSFA) model was used to analyze the relationship between three different kinds of formal care and informal family care. The formal complementary and substitute effects on informal care eventually led to higher actual informal care level. The net effect of formal care on informal care is positive, and the complementary effects of formal care are still dominant even in different regions. Increasing informal care does not crowd out or reduce formal care; thereby, facilitating the return of care to families can effectively reduce public service expenditures.
Journal Article
Socioeconomic status and ADL disability of the older adults: Cumulative health effects, social outcomes and impact mechanisms
Socioeconomic status (SES) is one of the important indicators affecting individual's social participation and resource allocation, and it also plays an important role in the health shock of individuals. Faced by the trend of aging society, more and more nations across the world began to pay attention to prevent the risk of health shock of old adults.
Based on the data of China Health and Retirement Longitudinal Study (CHARLS) in 2013, 2015 and 2018, this study uses path analysis and ologit model to empirically estimate the effects of SES and health shock on the activities of daily living (ADL) disability of old adults.
As a result, first, it was found that SES has significant impact on the disability of old adults. Specifically, economic conditions (income) plays dominant role. Economic status affects the risk of individual disability mainly through life security and health behavior. Secondly, SES significantly affecting health shock, with education and economic status showing remarkable impact, and there is an apparent group inequality. Furthermore, taking high education group as reference, the probability of good sight or hearing ability of the low education group was only 49.76% and 63.29% of the high education group, respectively, while the rates of no pain and severe illness were 155.50% and 54.69% of the high education group. At last, the estimation of path effect of SES on ADL disability indicates evident group inequality, with health shock plays critical mediating role.
SES is an important factor influencing residents' health shock, and health shocks like cerebral thrombosis and cerebral hemorrhage will indirectly lead to the risk of individual ADL disability. Furthermore, among the multi-dimensional indicators of SES, individual income and education are predominant factors affecting health shock and ADL disability, while occupation of pre-retirement have little impact.
Journal Article
Pathological study of the 2019 novel coronavirus disease (COVID-19) through postmortem core biopsies
Data on pathologic changes of the 2019 novel coronavirus disease (COVID-19) are scarce. To gain knowledge about the pathology that may contribute to disease progression and fatality, we performed postmortem needle core biopsies of lung, liver, and heart in four patients who died of COVID-19 pneumonia. The patients’ ages ranged from 59 to 81, including three males and one female. Each patient had at least one underlying disease, including immunocompromised status (chronic lymphocytic leukemia and renal transplantation) or other conditions (cirrhosis, hypertension, and diabetes). Time from disease onset to death ranged from 15 to 52 days. All patients had elevated white blood cell counts, with significant rise toward the end, and all had lymphocytopenia except for the patient with leukemia. Histologically, the main findings are in the lungs, including injury to the alveolar epithelial cells, hyaline membrane formation, and hyperplasia of type II pneumocytes, all components of diffuse alveolar damage. Consolidation by fibroblastic proliferation with extracellular matrix and fibrin forming clusters in airspaces is evident. In one patient, the consolidation consists of abundant intra-alveolar neutrophilic infiltration, consistent with superimposed bacterial bronchopneumonia. The liver exhibits mild lobular infiltration by small lymphocytes, and centrilobular sinusoidal dilation. Patchy necrosis is also seen. The heart shows only focal mild fibrosis and mild myocardial hypertrophy, changes likely related to the underlying conditions. In conclusion, the postmortem examinations show advanced diffuse alveolar damage, as well as superimposed bacterial pneumonia in some patients. Changes in the liver and heart are likely secondary or related to the underlying diseases.
Journal Article
Two B-box domain proteins, BBX28 and BBX29, regulate flowering time at low ambient temperature in Arabidopsis
Key messageThis paper demonstrates that BBX28 and BBX29 proteins in Arabidopsis promote flowering in association with the CO-FT regulatory module at low ambient temperature under LD conditions.Flowering plants integrate internal developmental signals with external environmental stimuli for precise flowering time control. The expression of BBX29 is up-regulated by low temperature treatment, but the biological function of BBX29 in low temperature response is unknown. In the current study, we examined the biological role of BBX29 and its close-related protein BBX28 in flowering time control under long-day conditions. Although neither BBX28 single mutant nor BBX29 single mutant has a flowering-associated phenotype, the bbx28 bbx29 double mutant plants have an obvious delayed flowering phenotype grown at low ambient temperature (16°C) compared to the wild-type (WT) plants. The expression of FT and TSF was lower in bbx28 bbx29 double mutant plants than in wild-type plants at 16°C. Both BBX28 and BBX29 interact with CONSTANS (CO), an important flowering integrator that directly binds to the FLOWERING LOCUS T (FT) promoter. In the effector-reporter assays, transcriptional activation activity of CO on the FT promoter was reduced in bbx28 bbx29 double mutant plants compared to that in WT plants. Taken together, our results reveal that BBX28 and BBX29 are promoters of flowering in Arabidopsis, especially at low ambient temperature.
Journal Article