Suchergebnisse

Piezoelectric materials, especially Pb-based piezoelectric materials, are widely used in the key components of sensors, actuators, and transducers. Due to the rising concern of the toxicity of Pb, global legislation has been adopted to restrict the use of Pb. Given that the available Pb-free piezoelectric materials cannot replace the Pb-based ones for various reasons, we designed and fabricated a low-Pb piezoelectric solid-solution ceramic system, (1–x)Ba(Zr0.18Ti0.82)O3–x(Ba0.78Pb0.22)TiO3 (denoted as BZ0.18T–xBP0.22T herein). The crystal structure, ferroelectric, dielectric, and piezoelectric properties of the BZ0.18T–xBP0.22T system were systematically studied. With the increase in BP0.22T content, the structure of the samples changed from a rhombohedral phase to a tetragonal phase; the intermediate composition x = 0.5 was located at the morphotropic phase boundary of the system and corresponded to the state with the coexistence of the rhombohedral and tetragonal phases. Moreover, x = 0.5 exhibited the optimum comprehensive properties among all the samples, with a piezoelectric coefficient d33 of 240 pC/N, a maximum dielectric temperature Tm of 121.1°C, and a maximum polarization Pm of 15 μC/cm2. Our work verifies the validity of the route to design low-Pb high-piezoelectric materials and may stimulate the interests for exploring new low-Pb high-performance ferroelectric and piezoelectric materials.

International audience ; Source-separated policy is very important for household solid waste (HSW) management in global megacities. The low proportion of source-separated collection has led to a low comprehensive utilization rate of municipal solid waste (MSW) in China. In March 2017, the Chinese government required major cities to fully implement compulsory source-separated systems by 2020. To determine policy impacts and efficiency in improving HSW sorting, the government launched a mandatory MSW source-separated program in Nanjing in November 2016. A household survey was implemented in three types of 11 communities over a period of 10 weeks. The results showed that approximately 52% of the respondents supported the mandatory policy and that household size was the most important sociodemographic factor influencing the support of the source separation policy. Income, gender, age, and knowledge play significant roles in different groups of respondents. This mandatory policy effectively improved the source-separated rate of HSW by 49.7%. Source-separated facilities investment, publicity investment, and special supervision coverage in these communities had significant positive effects on source-separated HSW. Every 1 million CNY investment in source-separated facilities and publicity will increase the source-separated rate of HSW by 1.1%. A 1.0% increase of special supervision coverage in communities can increase the source-separated rate by 3.6%. The findings from this study may help improve source-separated management of HSW for other cities in the future.

International audience ; Source-separated policy is very important for household solid waste (HSW) management in global megacities. The low proportion of source-separated collection has led to a low comprehensive utilization rate of municipal solid waste (MSW) in China. In March 2017, the Chinese government required major cities to fully implement compulsory source-separated systems by 2020. To determine policy impacts and efficiency in improving HSW sorting, the government launched a mandatory MSW source-separated program in Nanjing in November 2016. A household survey was implemented in three types of 11 communities over a period of 10 weeks. The results showed that approximately 52% of the respondents supported the mandatory policy and that household size was the most important sociodemographic factor influencing the support of the source separation policy. Income, gender, age, and knowledge play significant roles in different groups of respondents. This mandatory policy effectively improved the source-separated rate of HSW by 49.7%. Source-separated facilities investment, publicity investment, and special supervision coverage in these communities had significant positive effects on source-separated HSW. Every 1 million CNY investment in source-separated facilities and publicity will increase the source-separated rate of HSW by 1.1%. A 1.0% increase of special supervision coverage in communities can increase the source-separated rate by 3.6%. The findings from this study may help improve source-separated management of HSW for other cities in the future.

Source-separated policy is very important for household solid waste (HSW) management in global megacities. The low proportion of source-separated collection has led to a low comprehensive utilization rate of municipal solid waste (MSW) in China. In March 2017, the Chinese government required major cities to fully implement compulsory source-separated systems by 2020. To determine policy impacts and efficiency in improving HSW sorting, the government launched a mandatory MSW source-separated program in Nanjing in November 2016. A household survey was implemented in three types of 11 communities over a period of 10 weeks. The results showed that approximately 52% of the respondents supported the mandatory policy and that household size was the most important sociodemographic factor influencing the support of the source separation policy. Income, gender, age, and knowledge play significant roles in different groups of respondents. This mandatory policy effectively improved the source-separated rate of HSW by 49.7%. Source-separated facilities investment, publicity investment, and special supervision coverage in these communities had significant positive effects on source-separated HSW. Every 1 million CNY investment in source-separated facilities and publicity will increase the source-separated rate of HSW by 1.1%. A 1.0% increase of special supervision coverage in communities can increase the source-separated rate by 3.6%. The findings from this study may help improve source-separated management of HSW for other cities in the future.

International audience ; Source-separated policy is very important for household solid waste (HSW) management in global megacities. The low proportion of source-separated collection has led to a low comprehensive utilization rate of municipal solid waste (MSW) in China. In March 2017, the Chinese government required major cities to fully implement compulsory source-separated systems by 2020. To determine policy impacts and efficiency in improving HSW sorting, the government launched a mandatory MSW source-separated program in Nanjing in November 2016. A household survey was implemented in three types of 11 communities over a period of 10 weeks. The results showed that approximately 52% of the respondents supported the mandatory policy and that household size was the most important sociodemographic factor influencing the support of the source separation policy. Income, gender, age, and knowledge play significant roles in different groups of respondents. This mandatory policy effectively improved the source-separated rate of HSW by 49.7%. Source-separated facilities investment, publicity investment, and special supervision coverage in these communities had significant positive effects on source-separated HSW. Every 1 million CNY investment in source-separated facilities and publicity will increase the source-separated rate of HSW by 1.1%. A 1.0% increase of special supervision coverage in communities can increase the source-separated rate by 3.6%. The findings from this study may help improve source-separated management of HSW for other cities in the future.

Abstract Background Many visitors, including military troops, who enter highland regions from low altitude areas may suffer from acute mountain sickness (AMS), which negatively impacts workable man-hours and increases healthcare costs. The aim of this study was to evaluate the population level risk factors and build a multivariate model, which might be applicable to reduce the effects of AMS on Chinese young men traveling to this region. Methods Chinese highland military medical records were used to obtain data of young men (n = 3727) who entered the Tibet plateau between the years of 2006-2009. The relationship between AMS and travel profile, demographic characteristics, and health behaviors were evaluated by logistic regression. Univariate logistic models estimated the crude odds ratio. The variables that showed significance in the univariate model were included in a multivariate model to derive adjusted odds ratios and build the final model. Data corresponding to odd and even years (2 subsets) were analyzed separately and used in a simple cross-validation. Results Univariate analysis indicated that travel profile, prophylactic use, ethnicity, and province of birth were all associated with AMS in both subsets. In multivariate analysis, young men who traveled from lower altitude (600-800 m vs . 1300-1500 m, adjusted odds ratio (AOR) = 1.32-1.44) to higher altitudes (4100-4300 m vs . 2900-3100 m, AOR = 3.94-4.12; 3600-3700 m vs . 2900-3100 m, AOR = 2.71-2.74) by air or rapid land transport for emergency mission deployment (emergency land deployment vs . normal land deployment, AOR = 2.08-2.11; normal air deployment vs . normal land deployment, AOR = 2.00-2.20; emergency air deployment vs . normal land deployment, AOR = 2.40-3.34) during the cold season (cold vs . warm, AOR = 1.25-1.28) are at great risk for developing AMS. Non-Tibetan male soldiers (Tibetan vs . Han, AOR = 0.03-0.08), born and raised in lower provinces (eastern vs . northwestern, AOR = 1.32-1.39), and deployed without prophylaxis (prophylactic drug vs . none, AOR = 0.75-0.76), also represented a population at significantly increased risk for AMS. The predicted model was built; the area under receiver operating characteristic curve was 0.703. Conclusion Before a group of young men first enter a high altitude area, it is important that a health service plan should be made referring to the group's travel profile and with respect to young men's ethnicity and province of birth. Low-cost Chinese traditional prophylactic drugs might have some effect on decreasing the risk of AMS, although this needs further verification.