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Unlike Korean or Vietnamese adoptees who came to the U.S. during the postwar era, Chinese adoptees are mostly abandoned female infants under China’s one-child policy from 1980 through 2015. Little work has documented Chinese adoptees’ identity (trans)formation across time and space. This study examines how three Chinese adoptees from the U.S. who chose to go to Taiwan to teach English make sense of their Chinese heritages and their lives in and out of Asia. Drawing on the frameworks of positioning and chronotopic identities, this cross-sectional, multiple case study documents the participants’ identity (trans)formations through their narratives on their moves across the U.S., China, and Taiwan during different points of their lives. Our adoptee participants’ home and work experiences over time represent diverse pathways for their negotiations of various aspects of their identities – linguistic, cultural, Chinese, American, Asian American, and adoptee – in their life trajectories transnationally. Their diverse experiences complicate current understandings of adoptee identities within and across the adoptive home, the “homeland” of their birth places, and beyond.

Flumequine (FLU) and nadifloxacin (NAD), as emerging contaminants, have received extensive attention recently. In this study, a triazine-based microporous organic network (TMON) was synthetized and developed as an excellent adsorbent for FLU and NAD. The adsorption behavior and influence factors were investigated in both single and binary systems. Insight into the adsorption mechanisms were conducted through experiments, models, and computational studies, from macro and micro perspectives including functional groups, adsorption sites, adsorption energy and frontier molecular orbital. The results showed that the maximum adsorption capacities of TMON for FLU and NAD are 325.27 and 302.28 mg/g under 30 °C higher than records reported before. TMON exhibits the better adaptability and anti-interference ability for influence factors, leading to the preferable application effect in kinds of real water samples. TMON also shows the application potentials for the adsorption of other quinolone antibiotics and CO

The relationship between Pittsburgh Sleep Quality Index (PSQI) score and survival of dialysis patients has not been well studied. The aim of this study was to explore the association between PSQI score and all-cause mortality in dialysis patients. Fifty-one hemodialysis and 58 peritoneal dialysis patients were enrolled in this study. PSQI score > 5 and ≤ 5 indicated "poor sleepers" and "good sleepers", respectively. The primary outcome was all-cause mortality. Kaplan–Meier survival curve and Cox proportional hazards regression analysis were performed. The median PSQI score was 7.0 (4.0–10.0). Sixty-seven (61.5%) patients had poor sleep quality (SQ). Compared with good sleepers, poor sleepers had significantly lower levels of hemoglobin [74.0 (61.0, 85.0) vs. 78.0 (68.0, 97.0), P = 0.03] and serum bicarbonate (18.0 ± 4.5 vs. 20.0 ± 3.7, P = 0.022). The follow-up time was 69.1 ± 29.9 months. By multivariate Cox proportional hazards analysis, PSQI total score was the independent risk factor of all-cause mortality [hazard ratio (HR) 1.20, 95% confidence interval (CI) 1.05–1.36, P = 0.007]. Restricted cubic spline (RCS) analysis showed that 7 was the cutoff value at which the effect of PSQI score on mortality changed. Patients with a PSQI score > 7 had a 2.96-fold increased risk of all-cause mortality (HR 2.96, 95% CI 1.15–7.61, P = 0.025). PSQI score can be used as a predictor of all-cause mortality in dialysis patients, and those with PSQI > 7 were associated with increased odds of mortality.

The bionic-superhydrophobic surface is widely used in the field of wood protection. In this work, a novel room temperature vulcanized silicone rubber (RTVSR) superhydrophobic coating was fabricated onto the wood surface with the aid of SiO2 nanoparticles. The RTVSR/SiO2 superhydrophobic coating was composed of poly(methylhydrogens)siloxane (PMHS), vinyl-terminated polydimethylsiloxane (Vi-PDMS) and SiO2 nanoparticles, in which PMHS and Vi-PDMS reacted with each other to form a continuous phase and SiO2 nanoparticles increased the roughness of the coatings on wood surface. PMHS played the key role in assembly of rough surface and hence the fabrication of stable superhydrophobic surface. The formation mechanism of RTVSR/SiO2 superhydrophobic coating was discussed in detail. As a result, the modified wood had a water contact angle (WCA) of 164.4° and a sliding angle (SA) of 5°. Moreover, the super-hydrophobic coating on the surface of wood has excellent resistance to both high and low temperature, UV radiation, water impact and possesses self-cleaning property. The water absorption rate decreased obviously from 45.9 to 28.1% after depositing RTVSR/SiO2 superhydrophobic coating on wood. RTVSR/SiO2 superhydrophobic coating will find a great application in protection of hydroxyl-containing substrates, especially wood, in outdoor environment.

In this study, we investigated the emission characteristics of condensable particulate matter (CPM) and sulfur trioxide (SO3) simultaneously through ammonia-based/limestone-based wet flue gas desulfurization (WFGD) from four typical coal-fired power plants (CFPPs) by conducting field measurements. Stack emissions of filterable particulate matter (FPM) all meet the Chinese ultralow emission (ULE) standards, whereas CPM concentrations are prominent (even exceed 10 mg/Nm3 from two CFPPs). We find that NH4+ and Cl- increase markedly through the ammonia-based WFGD, and SO42- is generally the main ionic component, both in CPM and FPM. Notably, the occurrence of elemental Se in FPM and CPM is significantly affected by WFGD. Furthermore, the established chemical profiles in FPM and CPM show a distinct discrepancy. In CPM, the elemental S mainly exists as a sulfate, and the metallic elements of Na, K, Mg, and Ca mainly exist as ionic species. Our results may indicate that not all SO3 are included in CPM and they co-exist in stack plume. With the substantial reduction of sulfur dioxide (SO2), S distributed in SO3, CPM, and FPM becomes non-negligible. Finally, the emission factors of CPM and SO3 under typical ULE technical routes fall in the ranges of 74.33-167.83 and 48.76-86.30 g/(t of coal) accordingly.

Unexpected outbreak of the 2019 novel coronavirus (COVID-19) has profoundly altered the way of human life and production activity, which posed visible impacts on PM

The Hazardous air pollutants (HAPs) released from increasing municipal solid waste incineration (MSWI) plants have drawn great concerns in China. However, a full picture of their emission characteristics is still urgently needed, especially after the implementation of stricter emission limits on MSWI. In this study, a comprehensive historical emission inventory of HAPs emitted from MSWI plants in China during the period of 2006-2017 was dedicatedly established by integrating with detailed plant-level activity data and renewed localized emission factors. Overall, HAPs emissions initially increased with years, then peaked or slowed increase in the year 2014, but leveled off after 2016 due to the gradually and fully implementing of newly revised national emission standard (GB18485-2014) applied to mainland China and much stricter local standards for several provinces and cities. It was estimated that totally 50,716 tons (t) of NOx, 13,026 t of CO, 7988 t of SO

To avoid the spread of COVID-19, China implemented strict prevention and control measures, resulting in dramatic variations in air quality. Here, we applied a machine learning algorithm (random forest model) to eliminate meteorological effects and characterize the high-resolution variation characteristics of air quality induced by COVID-19 in Beijing, Wuhan, and Urumqi. Our RF model estimates showed that the highest decrease in deweathered PM

Rapid and accurate detection of pesticide and veterinary drug residues is a continuing challenge because of the complex matrix effects. Thus, appropriate sample pretreatment is a crucial step for the effective extraction of the analytes and removal of the interferences. Recently, the development of nanomaterial adsorbents has greatly promoted the innovation of food sample pretreatment approaches. Porous organic frameworks (POFs), including polymers of intrinsic microporosity, covalent organic frameworks, hyper crosslinked polymers, conjugated microporous polymers, and porous aromatic frameworks, have been widely utilized due to their tailorable skeletons and pores as well as fascinating features. This review summarizes the recent advances for POFs to be utilized in adsorption and sample preparation of pesticide and veterinary drug residues. In addition, future prospects and challenges are discussed, hoping to offer a reference for further study on POFs in sample pretreatment.

Volatile organic compounds (VOCs) are major precursors of ozone (O

To avoid the spread of COVID-19, China implemented strict prevention and control measures, resulting in dramatic variations in urban and regional air quality. With the complex effect from long-term emission mitigation and meteorology variation, an accurate evaluation of the net effect from lockdown on air quality changes has not been fully quantified. Here, we combined machine learning algorithm and Theil-Sen regression technique to eliminate meteorological and long-term trends effects on air pollutant concentrations and precisely detect concentrations changes those ascribed to lockdown measures in North China. Our results showed that, compared to the same period in 2015-2019, the adverse meteorology during the lockdown period (January 25th to March 15th) in early 2020 increased PM

Cement manufacturing is a major contributor to ambient particulate matter (PM) pollution in China, threatening urban and regional air quality improvement. Here, we tested the typical outlets (kiln tail, kiln head, and coal mill) in one shaft kiln and three rotary kilns to investigate the mass concentrations, size distributions, and chemical compositions of size-segregated PM. Results show that the concentrations of PM in most samples are lower than the strict local emission standards (10 mg/Nm3). We show that the characteristic chemical compositions in PM for most tested outlets are Ca and Ca2+, while for shaft kiln are K, S, K+, and SO42-, and organic carbon. Elemental carbon accounts for a relatively high proportion of PM emitted from coal mills. Meanwhile, unstable and abnormal operating conditions and variations on feed coal compositions will cause high levels of NH4+ and Cl- in PM from the kiln tail/head. Besides, the emission factors (EFs) of PM2.5, PM10, and PM after air pollution control devices for typical outlets of cement plants are calculated, which fall in ranges of 0.16-2.48, 1.49-18.46, and 3.32-35.35 g/(t of clinker), respectively. It suggests that mass emission characteristics, source profiles, and EFs of PM have changed notably as emission standards become more stringent. We believe the newly detailed size-segregated PM EFs and chemical profiles will help update and compile the refined emission inventory for current cement production in China.

The present study aimed to investigate the co-adsorption and application of water stabilized Fe

Vanadium is a strategically important metal in the world, although sustained exposure under high vanadium levels may lead to notable adverse impact on health. Here, we leverage a bottom-up approach to quantitatively evaluate vanadium emissions from both anthropogenic and natural sources during 1949-2017 in China for the first time. The results show that vanadium emissions increased by 86% from 1949 to 2005 to a historical peak value and then gradually decreased to 12.9 kt in 2017. With the effective implementation of air pollution control measures, vanadium emissions from anthropogenic sources decreased sharply after 2011. During 2011-2017, about half of vanadium emissions came from coal and oil combustion. In addition, industrial processes and natural sources also cannot be ignored, with the total contributions of more than 24%. The high levels of vanadium emissions were mainly distributed throughout the North China Plain and the eastern and coastal regions, especially in several urban agglomerations. Furthermore, the comprehensive evaluation by incorporating contrastive analysis, Monte Carlo approach, and GEOS-Chem simulation shows that vanadium emissions estimated in this study were reasonable and acceptable. The findings of our study provide not only a scientific foundation for investigating the health effects of vanadium but also useful information for formulating mitigation strategies.

This article examines language practice in international higher education (HE) in non-Anglophone countries, with a focus on language choice and negotiation in engineering and science lab me...

In order to probe the seasonal variation, formation mechanisms as well as geographical origins of fine particles and its chemical components in two cities (Zhengzhou, ZZ and Xinxiang, XX) in Central Plains Urban Agglomeration, daily PM2.5 aerosol samples were collected for four consecutive seasons during 2017–2018. The annual average concentrations of PM2.5 (particulate matter with an aerodynamic diameter smaller than 2.5 μm) were calculated at 70.5 ± 50.8 and 69.0 ± 46.3 μg m−3 at ZZ and XX, respectively. Daily ambient PM2.5 concentrations ranged from 18.2 to 303.0 μg m−3, among which >81% of the total sampling days exceeded the National Ambient Air Quality Standard of China (NAAQS, 35 μg m−3 as an annual average). Additionally, concentrations of PM2.5 and its major chemical components were seasonally dependent, usually with the highest mass concentration in winter. Compared with previous studies, higher NO3−/SO42− were observed in this study depicted that air pollution caused by motor vehicle exhaust cannot be ignored. OC concentration was higher at ZZ than XX during sampling campaign likely partially caused by larger number of motor vehicles, chemical pesticide and solvent used in ZZ. Both homogeneous and heterogeneous reactions played an important role in the formation of nitrate, while heterogeneous reactions dominated the formation of sulfate. We also found a faster increase in nitrate than in sulfate during the evolution of haze. The characteristics of long-range transportation of PM2.5 and its major chemical components and gaseous precursors were observed at both sites through back trajectories and WPSCF analysis, suggesting the complexity of air pollution and the multi-influence among cities.

In this work, a dual-emission ratiometric fluorescent probe of carbon dots-copper nanoclusters (CDs-Cu NCs) nanohybrids with bifunctional features was successfully assembled through mechanical mixing. The CDs were synthesized using ascorbic acid as a carbon source, and Cu NCs were prepared using d-penicillamine as the stabilizer and reducing agent. The as-prepared CDs-Cu NCs displayed two emission peaks (blue at 424 nm and red at 624 nm) when excited at 360 nm, and showed great stability. Interestingly, trace amount of Fe

Particulate matter (i.e., PM

Fine particulate matter (PM2.5) and its constituents pose great threatens to public health. The spatial-temporal characteristics of some key chemical constituents, such as sulfate, nitrate, and especially toxic trace elements in China has remained unclear, limiting further studies on evaluating the associated public health. Here, we conduct a two-yearlong (2012 and 2015) air quality simulation by coupling localized emission inventory for primary air pollutants and trace elements with a modified CMAQ model in a domain of China and five urban agglomerations. Associated health burdens of PM2.5 and various toxic trace elements are assessed applying exposure assessment models. The model successfully reproduces air pollution situations. Significant spatial-temporal variations of PM2.5 and chemical constituents are observed, with higher concentrations mainly occurred in North China Plain (NCP), Fenwei Plain (FWP) and Sichuan-Chongqing Basin (SCB). All chemical constituents in PM2.5 show higher concentrations in winter except for sulfate. From 2012 to 2015, the annual averaged PM2.5 concentration and its constituents decreased by 3% –20% nationally and regionally. Smaller reductions of nitrate make PM2.5 pollution become nitrate-dominated, especially in winter. Approximately 0.28 million deaths related to PM2.5 in China are avoided, while the population affected by the cancer risks of Cr (VI) and arsenic has slightly increased from 2012 to 2015. Our findings could provide critical insights on the mitigation of air pollution, as well as benefit for epidemiological studies on air pollutants related health effects.

The agricultural and forestry biomass direct-fired power generation represents an important technology to promote the low-carbon energy transition and agricultural waste reuse in China. In recent years, emissions of hazardous air pollutants (HAPs) caused by the rapid biomass industrialization have attracted increasing attention. To investigate the characteristics of HAPs emitted from biomass power plants in China, a multiple-year comprehensive emission inventory including NOx, SO2, PM, PM10, PM2.5, and trace elements (As, Cd, Cr, Cu, Hg, Pb, Zn) has been established for the period of 2006–2017. As a result of the emission standard (GB13223-2011), emissions of conventional HAPs have declined since 2014. The results show that national total emissions in 2017 were estimated at 29,516.0 t of NOx, 14,192.1 t of SO2, 4100.7 t of PM, 2353.9 t of PM10, 1630.6 t of PM2.5, 3057.2 kg of As, 1622.8 kg of Cd, 8285.8 kg of Cr, 54,443.4 kg of Cu, 132.9 kg of Hg, 66,325.8 kg of Pb, and 175,587.9 kg of Zn, respectively. The majority of HAPs emissions have been concentrated in eastern, northeastern, and central areas of mainland China. Shandong, Heilongjiang, and Anhui represent the top three provinces with the highest HAPs emissions from 2012 to 2017. Besides, the future emissions in 2025 and 2035 under the ultra-low emission policy are predicted with scenario analysis.

To explore high-resolution temporal variation characteristics of atmospheric metal elements concentration and more accurate pollution sources apportionment, online monitoring of metal elements in PM

Carbonaceous constituents have various adverse impacts on human health, visibility, and climate change. Although comprehensive studies on the characteristics of carbonaceous constituents have been conducted recently, systematic studies covering both the mass characteristics and light-absorption properties of carbonaceous constituents on a regional scale in China are quite limited. In this study, current seasonal measurements of organic carbon (OC) and elemental carbon (EC) in PM

To achieve ultralow-emission (ULE) standards, wet electrostatic precipitators (WESP) installed downstream from wet flue gas desulfurization (WFGD) have been widely used in Chinese coal-fired power plants (CFPPs). We conducted a comprehensive field test study at four 300 MW level ULE CFPPs, to explore the impact of wet clean processing (WFGD and WESP) on emission characteristics of three size fractions of particulate matter (PM: PM

Severe hazes occurred during 2016–2017 winter manifested winter haze was still a tough challenge in Beijing since the unprecedented haze in January 2013. Three haze episodes were identified from December 15, 2016 to January 15, 2017 in Beijing: the Red-Alert episode, the mixed haze-dust episode and the longest and heaviest Cross 2017 New Year's Haze episode. We analyzed the chemical components (water-soluble inorganic ions, carbonaceous components and trace elements) of multi-size airborne particles (PM1, PM2.5, PM10) samples, as well as the associated gaseous pollutants and meteorological parameters. Compared with the well-documented severe haze in January 2013, 2016–2017 winter haze was characterized by more stagnant synoptic conditions, sustained accumulation growth of PM enhanced by secondary reactions and regional contribution, as well as prominent fine particles mainly constituted by high concentrations of carbonaceous aerosol, secondary inorganic ions and anthropogenic elements. With strict pollution control measures since the enacting of Clean Air Action Plan in 2013, ambient concentrations of SO2, as well as SO42− and most anthropogenic elements in PM2.5 have decreased, whereas N O 3 − and N H 4 + concentration in PM2.5 increased by as high as 77.9% and 47.3% respectively compared with January 2013. The ratios of N O 3 − / S O 4 2 − in PM1, PM2.5, PM10 were higher than 1.0 no matter during normal period or haze period, totally different with the results in January 2013, which suggested the increased relative contribution from mobile sources and decreased contribution from coal combustion in Beijing. Nitrate and its precursors had become major concerns during winter haze in Beijing, although the rapid growth of sulfate still played an important role in the formation and evolution of extremely heavy haze events. Under ammonium-rich and high relative humidity conditions, N O 3 − was thought to mainly be produced by enhanced heterogeneous reactions. To prevent Beijing winter haze effectively, it's quite crucial to cut NOx, NH3, SO2 and VOCs emissions simultaneously and strengthen regional cooperation on air pollution control.

Colloidal quantum dots (QDs) have potential for several applications, e.g. as novel light sources; as photoluminescent probes; and for solar energy conversion devices, but their sensitivity towards their environmental surroundings, and the presence of surface defects may still degrade their emission properties. Herein, we present a post-synthetic treatment of CdTe QDs stabilized by mixed thiol ligands using chloride and bicarbonate ions to achieve near-complete surface passivation, resulting in a two-fold increase of the photoluminescence quantum yield (PL QY) and significant suppression of non-radiative recombination. Time-resolved PL measurements reveal fluorescence lifetime and PL QY trends did not both track identically; in the most favorable cases a suppression of non-radiative recombination and a slight increase in the radiative recombination rates after the salt treatment took place. The optimized conditions demonstrated here are proven to work for different sizes of CdTe QDs, and also show a dependence on the composition of the mixed ligand systems used.

Graphene quantum dots (GQDs) were synthesized via the oxygen-driven unzipping of graphene under ultra-high frequency ultrasonication, and then attached to the SiC nanoparticles by the hydrothermal method to form the SiC/GQDs nanocomposites. The SiC/GQDs exhibited superior photoactivity over the decomposition of perfluorooctane sulfonate (C8F17SO3H, PFOS), which was even harder to decompose than perfluorooctanoic acid (PFOA). This work presented the first instance of employing photoexcited semiconductor nanomaterials to realize the improvement from the activation of the –F2C–COOH bond in PFOA to the activation of –F2C–SO3H in PFOS. The decomposition rate constants (k) of 2-CF3-PFOS, 6-CF3-PFOS and linear-PFOS with SiC/GQDs were 0.127 h−1, 0.115 h−1, 0.098 h−1, and the corresponding half-lives were 5.5 h, 6.0 h, 7.1 h, respectively. The ratio of k (the branched isomers: the linear isomers) significantly reduced from the 967 times via vacuum ultraviolet (VUV) photolysis to the same order of magnitude in this work. The X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) were conducted to investigate the electronic properties of SiC/GQDs, revealing the centermost directional electron transfer process during the reaction. The photogenerated electron originated from the π-π∗ transition of the C C bond and the n-π∗ transition of the C O bond under UV excitation, transferred to SiC nanoparticles due to the heterojunction structure of SiC/GQDs, and then further transferred to the accumulated PFOS on the surface of SiC/GQDs for the electron-withdrawing property of sulfonate group, leading to the critical activation of sulfonate group. The decomposition mechanisms of PFOS involved the ionic headgroup cleavage, hydrolysis, hydrodefluorination, and the C–C bond scission.

In order to internationalize higher education, universities across Asia have engaged in aggressive recruitment of international students and increased provision of English-medium instruction (EMI). While many studies have examined Asian international students’ intercultural interactions during class discussions in Western/English-speaking countries, little is known about how the diverse students interact in EMI classes in the newly internationalized universities in Asia. This study analyzed interviews with 82 graduate students in a Taiwanese university to examine their classroom participation and identity construction in EMI. Findings indicate that Taiwanese and international students diverge in their frequency, manner, and content of speech in whole class discussions. Students explained the contrast in terms of cultural and linguistic identities while they also reported a dynamic two-way adjustment in their classroom behaviors over time. Previous studies emphasized the need for context-oriented a...

To investigate the up-to-date migration and emission characteristics of NH3/NH4+ in coal-fired power plants (CFPPs) after implementing ultralow emission retrofitting, typical air pollution control ...