The chromophores responsible for light absorption in atmospheric brown carbon (BrC) are not well characterized, which hinders our understanding of BrC chemistry, the links with optical properties, and accurate model representations of BrC to global climate and atmospheric oxidative capacity. In this study, the light absorption properties and chromophore composition of three BrC fractions of different polarities were characterized for urban aerosol collected in Xi'an and Beijing in winter 2013-2014. These three BrC fractions show large differences in light absorption and chromophore composition, but the chromophores responsible for light absorption are similar in Xi'an and Beijing. Water-insoluble BrC (WI-BrC) fraction dominates the total BrC absorption at 365 nm in both Xi'an (51 +/- 5%) and Beijing (62 +/- 13%), followed by a humic-like fraction (HULIS-BrC) and high-polarity water-soluble BrC. The major chromophores identified in HULIS-BrC are nitrophenols and carbonyl oxygenated polycyclic aromatic hydrocarbons (OPAHs) with 2-3 aromatic rings (in total 18 species), accounting for 10% and 14% of the light absorption of HULIS-BrC at 365 nm in Xi'an and Beijing, respectively. In comparison, the major chromophores identified in WI-BrC are PAHs and OPAHs with 4-6 aromatic rings (in total 16 species), contributing 6% and 8% of the light absorption of WI-BrC at 365 nm in Xi'an and Beijing, respectively.
This paper presents the W-band noise performance of the 22nm FDSOI CMOS technology. In detail, the mm-wave thin-oxide MOSFETs is characterized comprehensively in term of device geometries using the tuner-based noise measurement approach. To aid the noise analysis and extraction, the following study adopts an accurate small-signal equivalent circuit model validated well with bias-dependence up to 110 GHz. The effects of back-gate bias to the overall noise performance are also addressed in this work. The test devices exhibit low noise figure in the full W-band 75-110 GHz. Besides, NF min of 2.8 dB and 3.6 dB is recorded at 94 GHz respectively for the n- and p-FETs with 18nm gate-length (N f = 32, W f = 1.0 µm). The result of this study indicates the comparable performance of the 22nm FDSOI technology to other candidates for W-band applications.
When we are interested in high-dimensional system and focus on classification performance, the $\ell_{1}$-penalized logistic regression is becoming important and popular. However, the Lasso estimates could be problematic when penalties of different coefficients are all the same and not related to the data. We proposed two types of weighted Lasso estimates depending on covariates by the McDiarmid inequality. Given sample size $n$ and dimension of covariates $p$, the finite sample behavior of our proposed methods with a diverging number of predictors is illustrated by non-asymptotic oracle inequalities such as $\ell_{1}$-estimation error and squared prediction error of the unknown parameters. We compare the performance of our methods with former weighted estimates on simulated data, then apply these methods to do real data analysis.
We evaluate a reform of the US tax system switching to consumption taxation instead of income taxation. We do so in an environment that allows for progressivity of consumption taxes through differential tax rates between basic and non-basic consumption goods. The consumption tax system that maximizes aggregate welfare involves a 4% subsidy on basic consumption goods and a 68% tax on non-basic goods. Such a tax scheme generates 10% higher output in the long run, with a small increase in inequality. Nonetheless, the bench- mark with progressive income taxes and mild consumption taxes provides higher welfare on aggregate in the steady state, and even more so if we consider the transition.
Background
Some bereaved parents experience a decreasing trajectory of grief, while others fail to adapt over the long term and persistently suffer from negative health consequences. This study investigates the mediating role of social integration in the relationship between losing an only child and parental health in a family-oriented society.
Method
A sample of 1828 bereaved parents and 4739 non-bereaved parents was drawn from a 10-city survey in China. Regression methods were used to examine the impact of child loss on parental health, and Sobel test was applied to examine the mediating role of social integration.
Results
Bereaved parents who lost their only child have worse self-rated health and more negative affect than the non-bereaved parents, which lasted for years after the death of the only child. The Sobel test shows that 24.8% of the total effects on self-rated health and 6.7% of the total effects on negative affect can be explained via decreased social integration. The gender of parents and child as well as fertility intentions are important sources of heterogeneity in the Chinese culture.
Limitation
The results based on cross-sectional data may only reveal correlation rather than causality. The data was retrieved from self-reported questionnaires and there is a lack of objective measures of parental health. Moreover, the detailed mechanisms behind how child loss resulted in less social integration should be further explored.
Conclusions
Significant disparities in health outcomes and social integration were found for bereaved parents relative to the non-bereaved parents. Future work is needed to assess the health of bereaved parents, identify the vulnerable and disadvantaged groups, and design inclusive intervention programs.
The heterogeneous hydrolysis of dinitrogen pentoxide (N2O5) plays an important role in regulating NOx. The N2O5 uptake coefficient, c(N2O5), was determined using an iterative box model that was constrained to observational data obtained in suburban Beijing from February to March 2016. The box model determined 2289 individual c(N2O5) values that varied from <0.001 to 0.02 with an average value of 0.0046 +/- 0.0039 (and a median value of 0.0032). We found the derived winter c(N2O5) values in Beijing were relatively low as compared to values reported in previous field studies conducted during winter in Hong Kong (average value of 0.014) and the eastern U.S. coast (median value of 0.0143). In our study, field evidence of the suppression of c(N2O5) values due to pNO3 content, organics and the enhancement by aerosol liquid water content (ALWC) is in line with previous laboratory study results. Low ALWC, high pNO3 content, and particle morphology (inorganic core with an organic shell) accounted for the low c (N2O5) values in the North China Plain (NCP) during wintertime. The field-derived c(N2O5) values are well reproduced by a revised parameterization method, which includes the aerosol size distribution, ALWC, nitrate and organic coating, suggesting the feasibility of comprehensive parameterization in the NCP during wintertime. (C) 2020 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.
The diversity of vascular plants in Inner Asia has been researched; the main environmental factors determining the distribution of species belonging to various life forms and having different distribution range sizes have been identified. The key factors determining species diversity in Inner Asia are past climate changes and precipitation parameters. By contrast, the temperature conditions of the current climate do not affect the species richness significantly. The following current climatic parameters are important for woody plants: precipitation seasonality, mean precipitation in winter and spring, and diurnal range of temperature. Quite the opposite, the species richness of herbaceous plants is determined by climate-change velocity from the mid-Holocene and Last Glacial Maximum, the spatial heterogeneity of precipitation, and mean summer temperatures. Over time, distribution ranges of rare plants in the studied region may be reduced due to the increasing aridization.
Bilateral cross-currency SWAP agreements (BSAs) were rejuvenated during the GFC by the Federal Reserve of the United States to provide liquidity to selected governments in dire financial straits. After the crisis, BSAs rapidly and widely spread around the globe and become a major component of the global financial safety net. Interestingly, it is not the United States but China which occupies the center of the global BSA network. China has signed BSAs with a diverse pool of states since 2009, and has far more partners than any other countries. While existing studies mainly focus on the motivations driving China and its partner states to enter BSAs, this paper is intended to evaluate foreign policy consequences of China’s BSAs. Asymmetric interdependence and asymmetric information, as two key features of the economic relationship between China and its partner states in BSAs, are expected to make other countries be more supportive to China’s position in global affairs, leading to a convergence of their foreign policy preferences. This is the classic “Hirschman effect”.
To empirically identify the “Hirschman effect”, we use measures of states’ foreign policy ideal points based on votes in the United States General Assembly. We apply a quantitative analysis to estimate the average effect and conduct a case study to trace and explain the development of the effect over time. In the large-N study, we draw data on 191 countries between 2009 and 2018 and specify a multilevel model with varying intercepts to control for unobserved heterogeneity in the dimension of time and space. Empirical evidence suggests that BSAs significantly drive the foreign policy preferences of China and other states to converge. Then we focus on Argentina as an in-depth case study. Different from conventional case studies, we conduct a “quantitative case study” and apply the Synthetic Control Method to estimate and quantify the causal effect of signing a BSA with China in 2009 on the distance between foreign policy ideal points of Argentina and China. The case study confirms the presence of the “Hirschman effect” suggested by theory and found in the regression analysis. It further reveals several suggestive but interesting points, including 1) activating SWAP lines may strengthen the effect, whereas the effect may be weakened by the provision of emergency liquidity assistance from the US or the IMF; 2) BSAs with China may impact on left-wing governments more strongly than right-wing governments; and 3) the Chinese government may strengthen the effect by changing the size of the committed SWAP line.
