This paper presents a highly power efficient amplifier. By stacking inverters and splitting the capacitor feedback network, the proposed amplifier achieves 6-time current reuse, thereby significantly boosting gm and lowering noise but without increasing power. A novel biasing scheme is devised to ensure robust operation under 1V supply. A prototype in 180nm CMOS has 5.5uV rms noise within 10kHz BW while consuming only 0.25uW, leading to a noise efficiency factor (NEF) of 1.07, which is the best among reported amplifiers.
Structures of the two-dimensional atomic nuclei on ZnO (0001)-Zn and (0001)-O polar surfaces were studied by first principles density functional theory. The polarity-dependent nucleation dynamics was investigated by simulating two-dimensional (2D) nuclei consisting of 1-8 ZnO monomers on both polar surfaces. According to total energy calculations, average binding energy per ZnO monomer of the surface nuclei was analyzed to investigate if the nucleation and growth will proceed reasonably in physics. We found nucleation on (0001)-Zn surface was easier than that on (0001)-O surface. By using atomistic thermodynamics analysis, we calculated the Gibbs free energy of formation of these nuclei and made a comparison between the two polar surfaces. On (0001)-Zn surface, the critical Gibbs free energy of formation is much lower than that on (0001)-O surface under the same supersaturation, which leads to a much larger ZnO growth rate and rougher morphology, in accordance with experimental results. In addition, energetic analysis of nucleation at real thermodynamic conditions was achieved by introducing the temperature-and pressure-dependent chemical potentials of ZnO precursors. (C) 2017 Elsevier B.V. All rights reserved.
Introduction: The prevalence of multimorbidity is increasing in developed countries, while corresponding research in Chinese population is limited.Methods: A population-based cohort in Yinzhou located in an eastern coastal area of China (961,008 adults >=18 years in 2009; latest mortality follow-up: Nov 2015; 22,637 deaths; 6.53 million person-years at risk) was assembled by linking epidemiological surveys, electronic records for chronic disease management, health administrative and medical records databases. Multimorbidity was defined as the presence of two or more following disorders: hypertension, diabetes, cardiovascular disease or cancer. History of selected diseases was extracted from the electronic records for chronic disease management. Follow-up on fatal events is achieved through records linkage to the regional system of death surveillance.Results: Overall age- and sex-standardized prevalence of one, two or >=3 disorders were 16.16% (16.09% - 16.23%), 4.11% (4.07% - 4.15%) and0.36% (0.35% - 0.38%) respectively, whereas 41.73%, 14.41% and 1.67% were observed in people aged 60 years and older. The all-cause mortality rate adjusted to the age of 60 was 4.77 per 1000 person-years. Comparing to people without any selected diseases, the age- and sexadjusted HRs for all-cause mortality were 1.17 (1.14, 1.21) in those with one disorder, 1.78 (1.72, 1.86) in those with two morbidities, and 2.97 (2.76, 3.19) in those with >=3 morbidities. The HRs in those with multimorbidites were higher in younger people and were heterogeneous among different combinations of multimorbidites. Population-attributable fractions (PAF) for all-cause mortality due to one, two or >=3 disorders were 2.63%, 3.04% and 0.67% respectively (1.28%, 7.69% and 2.34% in people aged 60 years and older).Conclusions: The CHERRY study can serve as a valuable big data resource for scientific research in China. Multimorbidity is becoming acommon condition in Chinese population, especially in older population, and is associated with high mortality. A complementary strategy is required for population health interventions.Author Disclosures: H. Lin: None. D. Zhang: None. P. Shen: None. Z. Xu: None. Y. Si: None. X. Tang: None. P. Gao: None.
This review presents an overview of the analytical techniques for detecting the phase state of secondary organic aerosol (SOA), the effects of phase state on mass transport, and the types of SOA being studied. The previous studies showed that SOA could be solid, semi-solid, or liquid. The bulk diffusion coefficients for solid and semi-solid can be much smaller than those for liquid SOA, and therefore lead to limited mass transfer of species and different formation and transformation of SOA compared to liquid systems. However, only several types of SOA precursors have been studied, such as alpha-pinene, isoprene, and toluene. The phase state of SOA in urban areas as well as the effects of coexisting inorganic species on their phase state is largely unknown. Our analysis shows that the phase state perhaps play an important role in the rapid increase of secondary particle mass concentration during heavily hazed events. Therefore, it is important to study the phase state of SOA and the absorption and transfer of the key active gases at the surface and in the bulk of aerosols in the polluted environments, which will help us to further understand the mechanisms of the formation and evolution of secondary particles in China.总结了国内外对二次有机气溶胶(SOA)相态的研究进展,结果显示不同条件下SOA可能是固态、不定形态、液态.固态和不定形态SOA的体相扩散系数远低 于液态SOA,从而阻碍SOA的物质传输和化学转化等物理化学过程.目前,SOA相态的研究主要集中在有限体系,例如alpha-蒎烯、异戊二烯、甲苯等 挥发性有机物为前体物产生的SOA,缺乏实际大气SOA的相态信息.此外,对无机盐影响SOA相态的认识也十分有限.本文提出重污染形成过程中,相态可能 是二次颗粒物快速增长、转化的重要影响因素之一.因此,结合外场观测、实验室研究以及多层动力学模型研究重污染形成过程中SOA的相态及其对关键反应活性 气体的吸附、传输等影响机制,有助于深入理解我国复合大气污染条件下二次颗粒物的生成转化机制.
Age of complementary foods introduction is associated with childhood anemia, but the ideal age for the introduction of complementary foods to infants is a continuing topic of debate. We examined the longitudinal association between complementary foods introduction age and risk of anemia in 18,446 children from the Jiaxing Birth Cohort, who had detailed complementary feeding records at 3 and 6 months of age and had hemoglobin concentrations measured at 4-6 years. Early introduction of complementary foods at 3-6 months of age was significantly associated with a higher risk of anemia (odds ratio = 1.14; 95% confidence interval: 1.01-1.28) and a lower hemoglobin concentration of -0.84 g/L (95% confidence interval: -1.33 to -0.35) in children aged 4-6 years, compared with those fed complementary foods starting at 6 months of age. When it comes to the specific type of complementary foods, early introduction of all plant-based foods was associated with increased anemia risks and lower hemoglobin concentrations, while early introduction of most animal-based foods was not. These findings may be informative regarding the appropriate time to introduce complementary foods in infants.
Aggressive emission control measures were taken by the Chinese government after the promulgation of the 'Air Pollution Prevention and Control Action Plan' in 2013. Here we evaluated the air quality and health benefits associated with this stringent policy during 2013-2015 by using surface PM2.5 concentrations estimated from a three-stage data fusion model and cause-specific integrated exposure-response functions. The population-weighted annual mean PM2.5 concentrations decreased by 21.5% over China during 2013-2015, reducing from 60.5 in 2013 to 47.5 mu g m(-3) in 2015. Subsequently, the national PM2.5-attributable mortality decreased from 1.22 million ( 95% CI: 1.05, 1.37) in 2013 to 1.10 million ( 95% CI: 0.95, 1.25) in 2015, which is a 9.1% reduction. The limited health benefits compared to air quality improvements are mainly due to the supralinear responses of mortality to PM2.5 over the high concentration end of the concentration-response functions. Our study affirms the effectiveness of China's recent air quality policy; however, due to the nonlinear responses of mortality to PM2.5 variations, current policies should remain in place and more stringent measures should be implemented to protect public health.