A Japanese colony from 1895 to 1945, and then a retreat for the defeated Nationalist government beginning in 1949, Taiwan has been struggling to find its identity. Remnants of this identity crisis ...can be seen in political realm, with its extreme polarization on various social, political, and historical issues. This article explores the ongoing textbook controversy in Taiwan, situating it in evolving domestic and international contexts. It suggests that Taiwan society’s representation of its colonial and Cold War past is highly contested, which was influenced by democratization. It attempts to provide an overview of the course of the textbook controversy in Taiwan from a historical perspective, and to show the reactions from educators, students, and the general public. Through an analysis of the different ways that Taiwan’s history was interpreted and represented in its history textbooks, this article shows how these factors help construct Taiwan’s contested identity.
If future net-zero emissions energy systems rely heavily on solar and wind resources, spatial and temporal mismatches between resource availability and electricity demand may challenge system ...reliability. Using 39 years of hourly reanalysis data (1980-2018), we analyze the ability of solar and wind resources to meet electricity demand in 42 countries, varying the hypothetical scale and mix of renewable generation as well as energy storage capacity. Assuming perfect transmission and annual generation equal to annual demand, but no energy storage, we find the most reliable renewable electricity systems are wind-heavy and satisfy countries' electricity demand in 72-91% of hours (83-94% by adding 12 h of storage). Yet even in systems which meet >90% of demand, hundreds of hours of unmet demand may occur annually. Our analysis helps quantify the power, energy, and utilization rates of additional energy storage, demand management, or curtailment, as well as the benefits of regional aggregation.
The aerodynamic performance of wind turbines is essential to evaluate their electricity-generating capability. Compared with the wind turbines with traditional fixed structures, the aerodynamic ...performance of floating offshore wind turbines (FOWTs) is affected by the additional platform motion, especially for the pitch motion. In view of this, the computational fluid dynamics (CFD) method with the improved delayed detached eddy simulation (IDDES) is applied. Before the numerical simulation, the CFD model of the redesigned 1:50 scale rotor from NREL 5 MW wind turbine is verified with the available experimental data and numerical comparison. Then, the aerodynamics of the FOWT under the harmonic pitch motion with different periods and amplitudes is investigated. It is shown that the aerodynamic performance of the FOWT is sensitive to these parameters of the pitch motion. First, amplitudes of the rotor thrust and torque decrease with the increment of the pitch period. In particular, the wake interference phenomenon is the most evident when the pitch period is short and the pitch amplitude is high, which may compensate some energy to the rotor. In addition, amplitudes of the rotor thrust and torque increase with the increment of the pitch amplitude. Also, the stall phenomenon happens when the pitch amplitude is high, which may impact FOWTs’ aerodynamic performance adversely. Finally, the rotor power increases under the periodic pitch motion, especially by decreasing the period or increasing the amplitude. It is concluded that the pitch motion of the platform will change the aerodynamic performance of a wind turbine and should be taken into consideration during design procedure.
•IDDES model is employed to analyze the aerodynamics of a FOWT under pitch motion.•Effects of pitch periods are studied, and wake interference phenomenon is observed.•Effects of pitch amplitudes are investigated, and stall phenomenon is revealed.•The rotor power under periodic pitch motion is investigated.
The extensive application of plastic in human life brings about microplastic (MP) pollution in the environment. Identifying the potential sources of MPs is necessary to diminish its pollution. In ...this study, the occurrence, composition and distribution of MPs in the influents and effluents from 9 domestic wastewater treatment plants (WWTPs), 5 industrial WWTPs, wastewater of 10 industrial plants, 4 livestock farms and 4 fish ponds in China were investigated. Water samples were enzymatically treated followed by digestion with hydrogen peroxide and density separation. MPs were characterized using micro-Raman spectroscopy and were categorized by shape, size and color. Results showed that MP abundance in the influents and effluents of domestic WWTPs was 18–890 and 6–26 n·L−1, respectively, with the removal efficiency ranging from 35 to 98%. The effluents of industrial WWTPs contained 6–12 n·L−1 and the levels of MPs in the wastewater of industrial plants, livestock farms and fish ponds were in the range of 8–23, 8–40 and 13–27 n·L−1, respectively. No significant differences of MP abundance were demonstrated among effluents or wastewater of different sources, indicating they all constitute sources of MP pollution. Polyethylene (PE), polypropylene (PP) and polystyrene (PS) made up almost 83% of the total MPs. Fragment and film were the most abundant shapes and the majority of MPs were smaller than 500 μm. Polymer type and shape in different sources did not vary statistically, however, there were slight differences among different sources concerning size and color of MPs. This study could fill MP data gaps regarding different sources, guide future monitoring work and policy making.
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•A wide campaign has been performed to reveal MPs in different wastewater sources.•Levels of MPs in the influents of domestic WWTPs varied from 18 to 890 n·L−1.•Abundance of MPs in effluents or wastewater from different sources was 6–40 n·L−1.•Type and shape of MPs from different wastewater did not significantly vary.•Size and color of MPs slightly differed among wastewater from different sources.
We present a national-scale model analysis on the sources and processes of inorganic nitrogen deposition over China using the GEOS-Chem model at 1/2° × 1/3° horizontal resolution. Model results for ...2008–2012 are evaluated with an ensemble of surface measurements of wet deposition flux and gaseous ammonia (NH3) concentration, and satellite measurements of tropospheric NO2 columns. Annual total inorganic nitrogen deposition fluxes are simulated to be generally less than 10 kg N ha−1 a−1 in western China (less than 2 kg N ha−1 a−1 over Tibet), 15–50 kg N ha−1 a−1 in eastern China, and 16.4 kg N ha−1 a−1 averaged over China. Annual total deposition to China is 16.4 Tg N, with 10.2 Tg N (62%) from reduced nitrogen (NHx) and 6.2 Tg N from oxidized nitrogen (NOy). Domestic anthropogenic sources contribute 86% of the total deposition; foreign anthropogenic sources 7% and natural sources 7%. Annually 23% of domestically emitted NH3 and 36% for NOx are exported outside the terrestrial land of China. We find that atmospheric nitrogen deposition is about half of the nitrogen input from fertilizer application (29.6 Tg N a−1), and is much higher than that from natural biological fixation (7.3 Tg N a−1) over China. A comparison of nitrogen deposition with critical load estimates for eutrophication indicates that about 15% of the land over China experiences critical load exceedances, demonstrating the necessity of nitrogen emission controls to avoid potential negative ecological effects.
•Sources and processes controlling nitrogen deposition over China are quantified.•Reduced nitrogen (NH3) and dry deposition process are significant contributors.•15% of the China's land experiences critical load exceedances for eutrophication.
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•The ROS of venlafaxine and O-desmethylvenlafaxine were analyzed in liver tissue in the presence and absence of microplastic.•The enantiomeric bioaccumulation and metabolism of ...venlafaxine in the presence and absence of microplastic were studied.•R-venlafaxine and its metabolite R-O-desmethylvenlafaxine were biotransformed preferentially.•The distribution of venlafaxine and O-desmethylvenlafaxine in liver subcellular changed when co-exposure to microplastic.
In present study, we investigated the enantioselective behaviors of the chiral antidepressant venlafaxine and its metabolite O-desmethylvenlafaxine in loach Misgurnus anguillicaudatus (M. anguillicaudatus), as well as effects of microplastic on toxicity, distribution and metabolism through a 40-day co-exposure. The contents of SOD and MDA in loach liver elevated when the loach was exposed to venlafaxine and O-desmethylvenlafaxine. Moreover, co-exposure with microplastic might lead to more adverse effect against loach. The distribution of venlafaxine and O-desmethylvenlafaxine were both detected in loach tissues and liver subcellular. The concentrations of venlafaxine and O-desmethylvenlafaxine were lower in water in microplastic-present treatment. Whilst, more contaminants were accumulated in liver through the “vehicle” (microplastic). Enantioselective behavior of venlafaxine and O-desmethylvenlafaxine occurred with R-enantiomers being preferentially degraded. With microplastic present, the bioaccumulation factor (BAF) of venlafaxine and O-desmethylvenlafaxine in loach tissue amplified more than 10 times. In liver subcellular structure, microplastic may help to transport more compounds into subtle areas and postpone the contaminants metabolism in organisms. The present study for the first time gained an insight into the potential ecological effects and environmental behaviors of combined pollutions of chiral pharmaceuticals and microplastic, which could supply important information for environment risk assessment of concurrent organic pollutants and microplastic.
China is the largest contributor to global atmospheric mercury (Hg), and accurate emission inventories in China are needed to reduce large gaps existing in global Hg mass balance estimates and assess ...Hg effects on various ecosystems. The China Atmospheric Mercury Emission (CAME) model was developed in this study using probabilistic emission factors generated from abundant on-site measurements and literature data. Using this model, total anthropogenic Hg emissions were estimated to be continuously increasing from 356 t in 2000 to 538 t in 2010 with an average annual increase rate of 4.2%. Industrial coal combustion, coal-fired power plants, nonferrous metal smelting, and cement production were identified to be the dominant Hg emission sources in China. The ten largest contributing provinces accounted for nearly 60% of the total Hg emissions in 2010. Speciated Hg emission inventory was developed over China with a grid-resolution of 36 × 36 km, providing needed emission fields for Hg transport models. In this new inventory, the sectoral Hg speciation profiles were significantly improved based on the latest data from field measurements and more detailed technology categorization. The overall uncertainties of the newly developed inventory were estimated to be in the range of -20% to +23%.
The impacts of enhanced nitrogen (N) deposition on the global forest carbon (C) sink and other ecosystem services may depend on whether N is deposited in reduced (mainly as ammonium) or oxidized ...forms (mainly as nitrate) and the subsequent fate of each. However, the fates of the two key reactive N forms and their contributions to forest C sinks are unclear. Here, we analyze results from 13 ecosystem-scale paired
N-labelling experiments in temperate, subtropical, and tropical forests. Results show that total ecosystem N retention is similar for ammonium and nitrate, but plants take up more labelled nitrate (Formula: see text%) (Formula: see text) than ammonium (Formula: see text%) while soils retain more ammonium (Formula: see text%) than nitrate (Formula: see text%). We estimate that the N deposition-induced C sink in forests in the 2010s is Formula: see text Pg C yr
, higher than previous estimates because of a larger role for oxidized N and greater rates of global N deposition.
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