385 research outputs found
Blockchain application in circular marine plastic debris management
No full textThe threat to the environment and humanity caused by marine plastic debris has aroused global attention. This research aims to explore the feasibility of applying blockchain technology (BCT) in marine plastic debris management. A case study on three pioneer recycling organizations is conducted based on secondary data. The study found that BCT can be applied to solve some of the existing challenges of marine plastic debris management. A digital token system and identity recognition mechanism based on BCT can increase the public awareness for marine plastic debris governance. The derived digital wallets and distributed ledgers can effectively replace paper documents and cash transactions in the traditional recycling chain, and minimize global impact on local economies, thus improve efficiency and safety. Also, the traceability and high transparency of blockchain and the application of smart contracts can effectively build a global recycling network. In addition, the application of BCT can greatly improve the transparency of recycling value chains, and make them more accepting of supervision from society and consumers. This research is one of the first studies on BCT in marine plastic debris management and explores worldwide pioneering companies. In practice, this study can help companies analyse the defects in their own waste disposal models and help practitioners make decisions to adopt BCT. In academia, as one of the early exploratory studies on the application of BCT to the treatment of marine plastic debris, this study provides further empirical reference on BCT based business models and recycling chains, and can guide future research in this field
The game model of blue carbon collaboration along MSR — from the regret theory perspective
No full textOcean pollution and global warming are two pressing environmental problems exacerbated by human economic behavior. Building a blue carbon cooperation platform along the Maritime Silk Road (MSR) to promote sustainable development of countries along the route is of practical value to solving these two problems. Based on the analysis and review of the latest research on blue carbon, cooperative game and MSR, Weber’s law and regret theory are introduced to establish an economic model of blue carbon international cooperation, which proves the economic feasibility of blue carbon cooperation along MSR. The influence of psychological factors on the decision making of blue carbon international cooperation is also discussed. In addition, the measures to promote international cooperation are also discussed according to the current situation of marine blue carbon resources.</p
Critical behavior and long-range ferromagnetic order in perovskite manganite Nd
No full textThe critical behavior of perovskite manganite Nd0.55Sr0.45MnO3 has been investigated based on the static magnetization measurement around the paramagnetic-ferromagnetic transition temperature 273 K. A large critical exponent and a small one have been obtained by calculating the magnetic-field dependence of the magnetic-entropy change and the Widom scaling relation. These critical exponents not only obey the scaling hypothesis, but also corroborate the results obtained from the Kouvel-Fisher method. In comparison with the values given by standard models, these obtained exponents are very close to those expected from the mean-field model ( and ) and its magnetic-coupling type belongs to nearly long-range interaction. We suggest that the A-site spin disorder and localized magnetic phase competition are the main reasons for the actual critical exponents to show a slight deviation from the theoretical model
The study of the correlation between pollutants and their interactions on the incidence of tuberculosis in Changping District based on distribution models
No full textAbstract Background Air pollution as a potential risk factor, mediator or moderator of TB incidence. Most of the studies focused on the provincial and urban areas, while Changping District, as a high incidence area and county of tuberculosis in Beijing, its relationship with pollutants is not clear, so this study aims to investigate the associations of air pollutants and their interactions on the number of new TB cases in Changping District, Beijing, China. Methods Data from Beijing Changping Institute for Tuberculosis Prevention and Treatment on monthly new TB cases from 2014 to 2022. Distributed lag nonlinear models are used to examine the associations of each 10 µg/m3 increase in PM10 and NO2 concentrations, along with extreme exposure episodes, with TB incidence. Results The cumulative relative risk (RR) of increasing pollutant concentrations is positively correlated with lag months for PM10, but the opposite result is observed for NO2. In terms of long and short-term relationships, increased PM10 concentration and extremely low NO2 concentration are associated with long-term hazardous for most subgroups, while extremely high PM10 and NO2 concentrations are associated with short-term hazardous. Conclusion Increased concentrations of PM10 and NO2 having long-term or short-term effects on populations. Therefore, strengthening air quality monitoring and control is of great significance for the prevention of tuberculosis in Beijing
Clinical and Mycobacterium tuberculosis strain characteristics of tuberculosis patients with diabetes mellitus in Changping District, Beijing, China
No full textAbstract Background Diabetes mellitus (DM) is a major risk factor for tuberculosis (TB), However, limited research exists on their clinical and strain characteristics. This study aims to investigate the correlation between these factors in TB-DM patients in Changping District. Methods Whole genome sequencing (WGS) and drug susceptibility tests (DST) were performed on culture-positive strains. Spearman correlation analysis was used to examine risk factors and the correlation between lineage, cavities, and hemoptysis in the TB-DM population. The specificity, sensitivity, and confidence intervals for predicting phenotypic drug resistance based on genotypic resistance were calculated. Results Among the 3924 TB patients, 292 had DM, showing a doubling in the proportion of TB patients with DM over seven years. Among the 144 etiologically positive TB-DM cases treated at the Changping Institute for Tuberculosis Prevention and Treatment, 75% (108/144) of the patients exhibited tuberculosis lesions that formed cavities and 12.5% (18/144) with hemoptysis. A statistically significant difference in cavity formation across different age groups was observed (r = -0.198, P < 0.05). Out of the 144 etiologically positive patients, WGS successfully revived 73 MTB strains, with Lineage 2 being predominant. No statistical difference was found between lineages and the presence of cavities or hemoptysis. The DST results showed the highest resistance rates to isoniazid and streptomycin, both at 8.2% (6/73), with approximately one-quarter of the strains resistant to at least one anti-TB drug, and about half (47.1%, 8/17) resistant to first-line drugs. The study demonstrated good specificity but suboptimal sensitivity in predicting phenotypic drug resistance based on genotypic resistance. Conclusions The rising incidence of diabetes in tuberculosis patients within Changping District has intensified the spread of TB, with these patients demonstrating severe illness and high drug resistance. This study aims to develop targeted prevention and management strategies, offering crucial guidance for treating co-infections of TB and DM and controlling disease spread
Study on the instability mechanism and control technology of narrow coal pillar in double-roadway layout of Changping mine
No full textAbstract To address the issue of roadway support failure in narrow coal pillars under dual-lane layout, this study takes the 4309 working face of Changping Coal Mine as the engineering background and employs theoretical calculations, numerical simulations, and on-site monitoring to investigate the instability mechanisms of narrow coal pillars under dual-lane conditions and to optimize technical solutions. The results indicate that the internal stress distribution within the coal pillar is influenced by the advanced support stress, and as the working face advances, the gradually increasing advanced support pressure causes the vertical stress peak within the coal pillar to shift away from the goaf area. Computational analysis reveals that the vertical stress in the top region of a 6 m narrow coal pillar is 38% higher than that in the bottom region, with an average stress of 16 MPa in the coal pillar. The asymmetric high-level stress concentration within the coal pillar significantly affects its stability. A UDEC (Universal Distinct Element Code) model was established to compare four simulation schemes with cut-off angles of 0°, 5°, 10°, and 15°. Based on the analysis of damage parameters and fracture distribution in the narrow coal pillar roadway, it was concluded that the stability is best when the cut-off angle is 10°. The dense drilling cut-off unloading technology was applied to the 4309 working face of the Changping Mine based on the aforementioned research. On-site monitoring results show that the relative deformation of the roof and bottom plates and the two sides of the test section were controlled within 267 mm and 198 mm, respectively, effectively resolving the deformation and instability issues of the narrow coal pillars
Influence of oxygen vacancy deep trap levels on the EPIR effect in La0.5Ca0.5MnO3 ceramics
No full textLa0.5Ca0.5MnO3 (LCMO) ceramic samples were synthesized by solid state reaction under different atmospheres. The transport properties were investigated under the 2-wire mode. Remarkable Electrical Pulse Induced Resistance switching (EPIR) was observed at room temperature for the samples prepared in air. However, the EP1R-effect decreases with increasing temperatures and almost disappears when temperature is more than 450 K. One finds a stronger nonlinearity of the I-V characteristic and an even larger EPIR-effect for the samples sintered in argon. Based on the analysis of the I-V characteristics and the comparison with a standard PN junction, we submit that oxygen vacancies which exist near the surface of LCMO as deep level traps, is one of the key elements for these remarkable EPER effects. (C)2015 Published by Elsevier Ltd and Techna Group S.r.l
Statistical characteristics of the crop canopy reflectance data at different spatial scales before and after data analysis and correction with the new method in Shunyi District and Changping District of Beijing, China.
No full text<p>Statistical characteristics of the crop canopy reflectance data at different spatial scales before and after data analysis and correction with the new method in Shunyi District and Changping District of Beijing, China.</p
Histograms and Gaussian distribution characteristics of the crop canopy reflectance data at different spatial scales before and after data analysis and correction with the new method in Shunyi District and Changping District of Beijing, China.
No full text<p>Histograms and Gaussian distribution characteristics of the crop canopy reflectance data at different spatial scales before and after data analysis and correction with the new method in Shunyi District and Changping District of Beijing, China.</p
Molecular characterization of Cronobacter sakazakii in patients with diarrhea in a hospital in Changping District， Beijing， 2019
No full textObjectiveTo understand the current status of Cronobacter sakazakii (Cronobacter spp.) infection and its molecular epidemiological characteristics among patients with diarrhea, so as to provide evidence for the prevention and control of diarrhea disease caused by infection with Cronobacter spp. in Changping District, Beijing.Methods760 stool samples were collected from the diarrhea patients in a sentinel hospital in 2019, for the detection of Cronobacter spp., Salmonella, diarrheogenic Escherichia coli (DEC), and Vibrio Parahaemolyticus. Meanwhile, drug sensitivity experiment and pulsed-field gel electrophoresis (PFGE) typing analysis were conducted on the Cronobacter spp. strains isolated.ResultsA total of 20 Cronobacter spp. strains (2.63%) were isolated, with a lower detection rate than that of Salmonella and Vibrio Parahaemolyticus (χ2=9.052, P=0.011). However, there were no statistically significant differences between the detection rates in Cronobacter spp. and DEC (χ2=1.076, P=0.300). Seasonal characterization analysis showed that Cronobacter spp. could be detected in spring (1.00%), summer (4.17%), autumn (3.00%) and winter (1.67%), and the differences were statistically significant (χ2=662.700, P<0.001). The PFGE analysis showed that 20 PFGE banding patterns were found in 20 Cronobacter spp. strains, with a similarity coefficient ranging from 56.30% to 90.09% and a diverse PFGE banding pattern. The drug sensitivity experiment results showed that 18 (90.00%) strains were resistant to cefazolin, and 2 (10.00%) strains were intermediate. While, as for cefoxitin, 2 (10.00%) strains were resistant to it, and 5 (25.00%) strains were intermediate. All the 20 strains were 100.00% sensitive to the other 11 antibiotics.ConclusionIn the study, Cronobacter spp. is detected in all seasons through the year, with a high resistance rate to cefazolin, no multi-drug resistant bacteria appeared, and diverse PFGE banding patterns
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