60 research outputs found
Socioeconomic inequalities in human papillomavirus knowledge and vaccine uptake: evidence from a cross-sectional study in China
ObjectiveProviding the human papillomavirus (HPV) vaccine is effective to eliminate the disparity in HPV-related cancers. It is unknown regarding inequality in the distribution of HPV vaccination in China since the vaccine was licensed and approved for use in 2016. This study aimed to examine socioeconomic inequalities in HPV-related knowledge and vaccination and identified factors associated with such inequalities.MethodsSelf-administered questionnaires measuring HPV-related knowledge and vaccine uptake were completed by 1,306 women through online survey platform. HPV knowledge was assessed using a 12-item question stem that covered the hazards of HPV infection, HPV vaccine dosage, benefits, and protection. Cluster analysis by combining monthly household income, educational level, and employment status was used to identify socioeconomic status (SES) class. The concentration index (CI) was employed as a measure of socioeconomic inequalities in HPV-related knowledge and vaccination. Linear regression and logistic regression were established to decompose the contributions of associated factors to the observed inequalities.ResultsThe CI for HPV-related knowledge and vaccine uptake was 0.0442 and 0.1485, respectively, indicating the higher knowledge and vaccination rate were concentrated in groups with high SES. Education and household income made the largest contribution to these inequalities. Age, residency and cervical cancer screening were also important contributors of observed inequalities.ConclusionSocioeconomic inequalities in HPV-related knowledge and vaccination uptake are evident in China. Interventions to diffuse HPV-related information for disadvantaged groups are helpful to reduce these inequalities. Providing low or no-cost HPV vaccination and ensuring accessibility of vaccines in rural areas are also considered to be beneficial
Unveiling the spatial-temporal variation of urban land use efficiency of Yangtze River Economic Belt in China under carbon emission constraints
Under the constraint of carbon emission, measuring and analyzing the spatial-temporal evolution characteristics of urban land use efficiency in the Yangtze River Economic Belt is the inherent requirement of its ecological protection and sustainable development. In this paper, we calculated the urban land use efficiency of 107 cities in the Yangtze River Economic Belt from 2006 to 2020 by using the SBM-Undesirable model with unexpected output, and analyzed its temporal evolution trend and spatial correlation relationship by using kernel density and spatial autocorrelation method. The results showed that: except in 2020, the urban land use efficiency was generally low due to the COVID-19 epidemic, and the urban land use efficiency in other years was mostly concentrated in the middle levels, and showed a trend of slow fluctuation and rise year by year. The difference of urban land use efficiency level between regions increased, and the dispersion degree in upstream, midstream and downstream increased with each passing year. Urban land use efficiency spatial imbalance was significant, and the urban land use efficiency level of large and medium-sized cities was generally lower than that of cities with low economic development level. The spatial correlation was weak, and the global spatial autocorrelation was basically insignificant, while the local spatial agglomeration areas were mainly distributed in the upstream and downstream regions, with a small distribution range and weak spatial interaction. The distribution areas of the standard deviation ellipse were gradually flattened, and the center of gravity as a whole shift significantly to the southwest. The research results are helpful to understand the development history and future trend of urban land use efficiency in various regions, and propose that cities should consider the impact of public crisis events in advance, reasonably control the scale of land expansion, and lead coordinated development and other reasonable suggestions when formulating land use policies
Teacher cognition in teaching intercultural communicative competence: A qualitative study on preservice Chinese language teachers in Hong Kong SAR, China
The purpose of this study is to examine preservice Chinese language teachers’ cognition in teaching intercultural communicative competence. In the study we collected data through in-depth interviews with seven preservice teachers in a Master of Education program (Teaching Chinese as a Second Language, TCSL) at a university in Hong Kong SAR, China. The findings indicated that the participants had a relatively positive attitude and inclination toward the development of students’ intercultural communicative competence, while their conceptualizations of culture tended to be static and ambiguous. In addition, the participants’ objectives in teaching intercultural communicative competence were found to be more attitude-than knowledge- or skill-oriented. The study offers valuable insights that preservice language teachers’ cognition plays a crucial role in their future professional development and calls for curricular innovations with intercultural aims in teacher education programs
Functional Genes and Transcripts Indicate the Existent and Active Microbial Mercury-Methylating Community in Mangrove Intertidal Sediments of an Urbanized Bay
Mercury (Hg) methylation in mangrove sediments can result in the accumulation of neurotoxic methylmercury (MeHg). Identification of Hg methyltransferase gene hgcA provides the means to directly characterize the microbial Hg-methylating consortia in environments. Hitherto, the microbial Hg-methylating community in mangrove sediments was scarcely investigated. An effort to assess the diversity and abundance of hgcA genes and transcripts and link them to Hg and MeHg contents was made in the mangrove intertidal sediments along the urbanized Shenzhen Bay, China. The hgcA genes and transcripts associated with Thermodesulfobacteria [mainly Geobacteraceae, Syntrophorhabdaceae, Desulfobacterales, and Desulfarculales (these four lineages were previously classified into the Deltaproteobacteria taxon)], as well as Euryarchaeota (mainly Methanomicrobia and Theionarchaea) dominated the hgcA-harboring communities, while Chloroflexota, Nitrospirota, Planctomycetota, and Lentisphaerota-like hgcA sequences accounted for a small proportion. The hgcA genes appeared in greater abundance and diversity than their transcript counterparts in each sampling site. Correlation analysis demonstrated that the MeHg content rather than Hg content significantly correlated with the structure of the existent/active hgcA-harboring community and the abundance of hgcA genes/transcripts. These findings provide better insights into the microbial Hg methylation drivers in mangrove sediments, which could be helpful for understanding the MeHg biotransformation therein
Exploring the Spatial Network Structure of Agricultural Water Use Efficiency in China: A Social Network Perspective
The exploration of the spatial network structure of agricultural water use efficiency (AWUE) and its influencing factors for promoting water saving and improving water use efficiency in regional agricultural production is of great importance. In this paper, the modified gravity model and social network analysis methods were used to study the spatial correlation characteristics and influencing factors of AWUE in China between the years 2008 and 2019. It was found that (1) the overall trend of AWUE in China has been fluctuating and declining, and there are obvious differences in AWUE in each region; (2) the spatial network structure of AWUE in China is complex and relatively stable, with close interprovincial connections and obvious spatial spillover effects; (3) Shanghai, Beijing, Jiangsu, and Zhejiang are at the center of the network; and (4) the differences between geographical adjacency, technological development level, farmers’ income, and natural resource endowment have significant effects on the development of the AWUE network. These results provide a theoretical basis for the government to improve AWUE and promote collaborative regional development
Exploring the Spatial Network Structure of Agricultural Water Use Efficiency in China: A Social Network Perspective
The exploration of the spatial network structure of agricultural water use efficiency (AWUE) and its influencing factors for promoting water saving and improving water use efficiency in regional agricultural production is of great importance. In this paper, the modified gravity model and social network analysis methods were used to study the spatial correlation characteristics and influencing factors of AWUE in China between the years 2008 and 2019. It was found that (1) the overall trend of AWUE in China has been fluctuating and declining, and there are obvious differences in AWUE in each region; (2) the spatial network structure of AWUE in China is complex and relatively stable, with close interprovincial connections and obvious spatial spillover effects; (3) Shanghai, Beijing, Jiangsu, and Zhejiang are at the center of the network; and (4) the differences between geographical adjacency, technological development level, farmers’ income, and natural resource endowment have significant effects on the development of the AWUE network. These results provide a theoretical basis for the government to improve AWUE and promote collaborative regional development
Block Shear Strength and Delamination of Cross-Laminated Timber Fabricated with Japanese Larch
Process parameters of cross-laminated timber (CLT) fabricated with Japanese larch were evaluated. The process parameters were designed by using an orthogonal test including pressure, glue consumption, and adhesive. Both delamination and block shear tests were conducted on CLT in accordance with GB/T 26899 (2011). The results showed that the optimum process parameters were A2B3C2 including pressure (1.2 MPa), glue consumption (200 g/m2), and amount of adhesive (one-component polyurethane). The weight loss and moisture absorption increased when the temperature increased, but the block shear strength decreased as the temperature was raised from 20 °C to 230 °C
Analysis and Revision of Torque Formula for Hydro-viscous Clutch
Hydro-viscous clutch is a speed-regulating device for heavy fans and water pumps. It has important engineering significance in the fields of soft-start for rotating machinery. More and more attention has been paid to its torque and control characteristics. This paper is focused on the torque formula for hydro-viscous clutch (HVC), assuming that multi-friction plates distribute ununiformly with different oil film thickness. A mathematical model of friction plates was constructed, then the distribution formula of the oil film thickness was obtained. A new expression was presented using a modified factor. Parameters such as pressure, viscous torque, and oil film thickness were obtained. The results show that each clearance of friction plates is not the same and the distribution of oil film thickness is influenced by pressing force, groove depth, angular ratio of groove/non-groove, and static friction force. To verify the proposed expression, relevant experiments were carried out on an HVC with multi-friction plates, and the experimental results indicate that the new expression is more accurate compared to the original one
The Development and Nonlinear Adaptive Robust Control of the Air Chamber Pressure Regulation System of a Slurry Pressure Balance Shield Tunneling Machine
The rapid and accurate control of air chamber pressure in slurry pressure balance (SPB) shield tunneling machines is crucial for establishing the balance between slurry pressure and soil and water pressure, ensuring the stability of the support face. A novel air chamber pressure control method based on nonlinear adaptive robust control (ARC) and using a pneumatic proportional three-way pressure-reducing valve is proposed in this paper. Firstly, an electric proportional control system for the air chamber pressure is developed. Secondly, a nonlinear state space model for the air chamber pressure regulation process is established. Utilizing experimental data from the SPB shield tunneling machine test bench, nonlinear adaptive identification is conducted through the nonlinear recursive least square algorithm. The results demonstrate the model’s effectiveness and accuracy. Then, a nonlinear ARC for air chamber pressure is designed based on the backstepping method, and its Lyapunov stability is proved. Finally, the feasibility and effectiveness of the controller designed in this paper is verified through simulation and experiments. The results demonstrate that the developed control system can compensate for the nonlinearity and disturbance in the air chamber pressure regulation process. It can achieve good transient and steady-state performance and has good robustness against uncertainty
Performance Analysis of Electro-Hydraulic Thrust System of TBM Based on Fuzzy PID Controller
The tunnel boring machine (TBM) is widely used in tunnel construction projects. The thrust system plays a crucial role to drive the machine ahead and support gripper shoes stably while tunneling. More and more attention has been paid to the pressure and velocity regulation efficiency as the TBM advances in complex rock conditions to ensure the stabilization of the tunneling process. A thrust hydraulic control system, assembled with a proportional pressure reducing valve, is established with system operating parameters. The mathematical model of the thrust electro-hydraulic system is revealed. To improve the control characteristics of the thrust system, a self-tuning fuzzy PID controller is introduced in the pressure and velocity regulation procedures. After that, tests on a Φ2.5 m scaled TBM test rig are carried out. The test results show that the thrust system adopting the fuzzy PID controller results in less oscillation and a smoother regulation process. It takes less time to reach the target goal of pressure regulation with less vibration during the pressure regenerating periods, and both systems of conventional PID controller and fuzzy PID controller are qualified in velocity regulation movements. The proposed control methods show better benefits in reduction of vibrations and shorter time of regulation to stable conditions, which extends the machine’s life and affects the acceleration of the tunneling process
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