Large Emission Research Articles

Fossil Fuel Subsidy Inventories vs. Net Carbon Prices

Price incentives for reducing fossil fuel related carbon emissions are an important component of effective and efficient climate policy. Current incentives stem from a mixture of energy taxes and carbon pricing (incentivizing less emissions) and diverse support measures for fossil fuels (incentivizing more emissions). We develop a net carbon price indicator that complements existing subsidy and carbon pricing indicators. It can be calculated on different aggregation levels and compared across countries. We calculate the different components and our aggregate indicator for the year 2018 and for eight countries including the worlds’ six largest emitters. Our analysis reveals large differences in net carbon prices across countries and across sectors within countries. We argue that the sectoral differences can inform about adequate national policy reforms while the aggregate national indicator can be useful for international negotiations about comparable national efforts.

Adaptive infrared radiation modulator using reversible metal electrodeposition with silicon carbide-based fabry-perot cavity

Conventional materials that statically modulate radiation in the infrared (IR) region of the electromagnetic spectrum underpin the performance of many entrenched technologies. The development of their adaptive variants, whereby the IR radiation properties dynamically change as a response to external stimuli, has emerged as an important unfulfilled scientific challenge. Here, by combining the silicon carbide (SiC)-based Fabry-Perot (FP) cavity effect with the traditional reversible metal electrodeposition device (RMED), where the FP cavity is used as a color filter to emit a particular wavelength and the RMED is used to reversibly modulate IR radiation, we develop an adaptive IR radiation modulator with large and uniform IR emissivity tunability (Δε ≥ 0.579) in the 3–14 µm region. A specific structural color which is a function of the SiC thickness can be simultaneously displayed when the modulator is in the low-emissivity mode. By varying the SiC thickness from 100 to 180 nm, a full gamut of colors spanning the entire visible spectrum can be achieved. Additionally, the modulator can exhibit fantastic patterns consisting of different structural colors with simple designs achieved. We believe that our findings may open opportunities for camouflage in multispectral detection and many technologies related to IR radiation management.

Reformer + Membrane separator plant for decarbonized hydrogen production from Biogas/Biomethane: An experimental study combined to energy efficiency and exergy analyses

Nowadays, the world energy production is still based on the exploitation of fossil fuels, mainly oil, coal, and natural gas, responsible for large greenhouse emissions in the environment. According to the measures proposed by the European Green Deal to meet the carbon neutrality by 2050, the decarbonisation of the global energy production processes represents a top priority. Hydrogen represents a carbon-free energy carrier, useful to drive the society toward a decarbonized-economy. The novelty of this work is represented by the experimental generation of clean hydrogen by a two stages plant constituted of a biogas/biomethane steam reformer and a Pd-Ag membrane separator, meanwhile applying on this simple case the methodology of the exergy analysis, identifying the main losses and suggesting improvements. Hence, it deals with the exergy analysis of the whole system with the process intensification operated by the membrane separator adopted instead of using several stages to separate/purify hydrogen − as conventionally done after the reforming stage (two water gas shift reactors, high and low temperature, followed by a pressure swing adsorption stage) − with the objective of recovering decarbonized hydrogen coming from the biogas/biomethane steam reformer, meeting the European targets indicated by the Clean Hydrogen Alliance. This approach allowed to understand the amount of irreversibilities present in such a system as well as how the thermal efficiency may be influenced by a number of parameters, constituting globally a baseline for the scaling up of this process technology from lab to bench/pilot scale. The best results of this work highlight that the utilization of biomethane in the feed stream to generate hydrogen resulted to be a better choice than biogas in terms of thermal efficiency (based on the lower heating value) of the whole system, equal to 73 % at 773 K, while the highest percentage of exergy destruction was concentrated in the condensation stage, with values varying between 76 % and 93 %, depending on the feed stream typology. The two stages system was able to meet the “decarbonized hydrogen production target 2027”, with a hydrogen recovery of 90 % and a purity of 99.9999 %. Last but not least, the overall exergy destroyed efficiency of the overall system in the two analyzed cases was 92 % (biomethane feed stream) and 88 % (biogas feed stream), respectively.

Computational screening of multi-resonance thermally activated delayed fluorescence (MR-TADF) molecules for lasing application

Multi-resonance thermally activated delayed fluorescence (MR-TADF) molecules charactering large emission oscillator strengths, effective reverse intersystem crossing (RISC), and narrow emission spectral width, have great potential as laser materials. We propose a molecular descriptor for quick screening MR-TADF molecules as laser candidate materials, A =ΔESTσeffnet,opt, namely, the product of singlet-triplet energy gap and the optical pumping net stimulated emission cross section. These quantities can be calculated by combining quantum chemistry package Gaussian and our own MOMAP program. Through extensive computations benchmarked with existing experiments, we suggest that A value should be larger than 0.311 ⨉ 10−17 cm2 eV for promising lasing molecules. We virtually designed 119 molecules with MR-TADF property, and based on our theoretical protocol by considering descriptor A, we are able to select 10 molecules as lasing molecules. We then further screen out 2 molecules through analyzing the spectral overlap, indicating that only eight molecules are prospective candidates for laser materials. Particularly, we find that ADBNA-Me-BPy molecule possesses large radiative decay rate and large reverse intersystem crossing rate, 1.90 × 106 s−1 and 1.01 × 108 s−1, respectively, implying a low lasing threshold, promising for electrically pumped lasing.

Consequences of increasing greenhouse gas emissions: case study on the impact of the food industry

The global carbon footprint has increased to frightening heights due to rising greenhouse gas emissions, mainly from the energy and industrial sectors, which include the food industry. This case study examines how the industry's carbon emissions have changed over time, highlighting the sector's major environmental impact and the pressing need to implement decarbonization plans. The particularity of the study lies in the analysis of the crucial role that emissions from the food industry play in global emissions. An overview of the global industrial carbon footprint was created through an analysis of carbon emissions data from multiple sources, with a particular focus on the food industry. Since the Industrial Revolution, carbon dioxide emissions have increased dramatically worldwide, reaching a record high of 36.3 billion tons in 2019. With around 23% of global emissions coming from industry, the energy sector is the largest emitter. The main cause of emissions is the use of fossil fuels in heavy industries such as steelmaking, cement, and chemicals; the two largest emitters are China and the United States. Achieving the goals outlined in the Paris Agreement and halting climate change requires reducing carbon emissions from the food industry. The adoption of low-carbon technologies, increased energy efficiency and a shift to cleaner energy sources are essential remedies. The industrial sector needs to decarbonize faster, and this can only be achieved through international cooperation and strong government regulations.

Advancing Regional–Scale Spatio–Temporal Dynamics of FFCO2 Emissions in Great Bay Area

Estimating city–scale emissions using gridded inventories lacks direct, precise measurements, resulting in significant uncertainty. A Kalman filter integrates diverse, uncertain information sources to deliver a reliable, accurate estimate of the true system state. By leveraging multiple gridded inventories and a Kalman filter fusion method, we developed an optimal city–scale (3 km) FFCO2 emission product that incorporates quantified uncertainties and connects global–regional–city scales. Our findings reveal the following: (1) Kalman fusion post–reconstruction reduces estimate uncertainties for 2000–2014 and 2015–2021 to ±9.77% and ±11.39%, respectively, outperforming other inventories and improving accuracy to 73% compared to ODIAC and EDGAR (57%, 65%). (2) Long–term trends in the Greater Bay Area (GBA) show an upward trajectory, with a 2.8% rise during the global financial crisis and a −0.19% decline during the COVID-19 pandemic. Spatial analysis uncovers a “core–subcore–periphery” emission pattern. (3) The core city GZ consistently contributes the largest emissions, followed by DG as the second–largest emitter, and HK as the seventh–highest emitter. Factors influencing the center–shift of the pattern include the urban form of cities, population migration, GDP contribution, but not electricity consumption. The reconstructed method and product offer a reliable solution for the lack of directly observed emissions, enhancing decision–making accuracy for policymakers.

California wildfire smoke contributes to a positive atmospheric temperature anomaly over the western United States

Abstract. Wildfires in the southwestern United States, particularly in northern California (nCA), have grown in size and severity in the past decade. As they have grown larger, they have been associated with large emissions of absorbing aerosols and heat into the troposphere. Utilizing satellite observations from MODIS, CERES, and AIRS as well as reanalysis from MERRA-2, the meteorology associated with fires during the wildfire season (June–October) was discerned over the nCA-NV (northern California and Nevada) region during the period 2003–2022. Wildfires in the region have a higher probability of occurring on days of positive temperature (T) anomalies and negative relative humidity (RH) anomalies, making it difficult to discern the radiative effects of aerosols that are concurrent with fires. To attempt to better isolate the effects of large fire emissions on meteorological variables, such as clouds and precipitation, variable anomalies on high fire emission days (90th percentile) were compared with low fire emission days (10th percentile) and were further stratified based on whether surface relative humidity (RHs) was anomalously high (75th percentile) or low (25th percentile) compared with typical fire season conditions. Comparing the simultaneously high fire emission and high RHs data with the simultaneously low fire emission and high RHs data, positive tropospheric T anomalies were found to be concurrent with positive AOD anomalies. Further investigation found that due to shortwave absorption, the aerosols heat the atmosphere at a rate of 0.041 ± 0.016 to 0.093 ± 0.019 K d−1, depending on whether RH conditions are anomalously positive or negative. The positive T anomalies were associated with significant negative 850–300 hPa RH anomalies during both 75th percentile RHs conditions. Furthermore, high fire emission days under high RHs conditions are associated with negative CF anomalies that are concurrent with the negative RH anomalies. This negative CF anomaly is associated with a significantly negative regional precipitation anomaly and a positive net top-of-atmosphere radiative flux anomaly (a warming effect) in certain areas. The T, RH, and CF anomalies under the simultaneously high fire emission and high RHs conditions compared with the simultaneously low fire emission and high RHs conditions have a significant spatial correlation with AOD anomalies. Additionally, the vertical profile of these variables under the same stratification is consistent with positive black carbon mass mixing ratio anomalies from MERRA-2. However, causality is difficult to discern, and further study is warranted to determine to what extent the aerosols are contributing to these anomalies.

Exploring the realization pathway of carbon peak and carbon neutrality in the provinces around the Yangtze river of China

As major strategic development areas in China, the provinces around the Yangtze River are facing the pressure of large aggregate CO2 emissions and high per capita CO2 emissions. The study on the pathway of reducing CO2 emissions and increasing carbon sequestration will help China better clarify the ways realize the goals of carbon peak and carbon neutrality as soon as possible. In this paper, the extended STIRPAT model and OLS regression were used to establish a prediction model to estimate the CO2 emissions during 2010–2060 under different scenarios. Meanwhile, the InVEST model was used to estimate the carbon sequestration, and the comparison with the CO2 emissions was analyzed. The results show that Qinghai and Yunnan have achieved the goal of carbon neutrality in 2010. Under the low-carbon and energy-saving scenario and the baseline scenario, all provinces within the study area are anticipated to attain their emissions peak by 2030 or earlier, and the CO2 emissions peak value of the whole study area is 3111 Mt and 3199 Mt, respectively. While under the high emissions scenario, only Chongqing and Qinghai will reach the emissions peak in 2030, and the whole study area will reach the emissions peak in 2040, with peak value of 3470 Mt. Under the three scenarios, the whole study area cannot achieve carbon neutrality before 2060. Only Sichuan and Hubei can achieve carbon neutrality in 2050 and 2060 under the low-carbon and energy-saving scenario. All provinces and municipalities in the lower reaches of the Yangtze River are facing huge pressure of emissions reduction. The research reveals that the goals of carbon peak and carbon neutrality should be achieved by developing clean energy, transforming industrial structure, increasing carbon sequestration and improving carbon emissions trading system.

Physical-chemical characterization of construction and demolition waste powder with thermomechanical activation for use as supplementary cementitious material

Cement production is responsible for large anthropogenic CO2 emissions into the atmosphere, partly through the decarbonization of limestone rock. Reducing the clinker/cement ratio is a viable alternative to reducing the environmental impact of construction. To achieve this, the continued exploration of additional cementitious materials is necessary. With adequate particle size and chemical composition, construction and demolition waste powder (CDWP) can be used as supplementary cementitious material (SCM). In this sense, the present work aims to evaluate the CDWP physical-chemical characteristics when subjected to thermomechanical treatment (calcination and milling), aiming for application as SCM. The powders (fraction smaller than 150 µm) were subjected to different calcination temperatures (600, 700, 800, and 900°C) without milling and milled for 5 hours. The physicochemical characterization was carried out using laser granulometry, X-ray diffraction (XRD), thermogravimetry (TG), X-ray fluorescence (XRF), BET, scanning electron microscopy (SEM), specific mass, pozzolanic activity index (PAI) and Portlandite consumption. The results indicate that thermomechanical activation made it possible to obtain a powder with physical-chemical characteristics of interest for application as SCM. The amount of Si2O, Fe2O3, and Al2O3 is greater than 70 %, making them suitable. Calcination from 700°C presents a loss of ignition of less than 6 %, meeting regulatory requirements for pozzolanic materials. Milled for 5 hours leads to a 75 % reduction in particle mean diameter. With the combination of thermal and mechanical treatments, a PAI of 97 % was obtained, and a decrease in the quantity of Portlandite of 12 %. Analysis of variance (ANOVA) indicated a significant influence of thermal and mechanical treatment on the compressive strength of mortars. Based on the data found, it can be stated that CDWP has the potential to be used as an SCM, decreasing CO2 emissions from the cement industry and contributing to the circular economy of the construction sector.

Electrofluorochromic Hydrogels by Oligothiophene-Based Color-Tunable Fluorescent Dye Doping.

Soft electronic materials hold great promise for advancing flexible functional devices. Among the various soft materials available, hydrogels are particularly attractive for soft electronic device development due to their inherent properties, including transparency, shape adaptability through swelling/deswelling, and self-healing capabilities. Transparent hydrogels contribute to the creation of advanced smart devices such as sensors, smart windows, and anticounterfeiting technologies. Poly(vinyl alcohol) hydrogels are used as a platform for creating electrofluorochromic (EFC) devices in combination with oligothiophene-conjugated benzothiazole derivatives (OCBs) as fluorescent emitters. OCBs demonstrated excited-state intramolecular proton transfer (ESIPT) behavior with a large Stokes shift and emission changes responsive to solvent polarity and pH stimuli. Even in the solid state, OCBs exhibited strong fluorescence emission across a wide range of colors from blue to red, making them exceptionally well-suited for EFC device development. Their quantum yields in the powder state were obtained between 2.3% and 19.9%. Through the incorporation of OCBs into a PVA hydrogel (OCB@PVA), we achieved the successful fabrication of flexible EFC devices, including electronic paper and smart panels. When electric potentials (-2.4 and +2.4 V) were applied in OCB@PVA, fluorescence color changes were observed by an electrochemically induced pH change owing to electrohydrolysis of water. These devices demonstrated the potential of OCB@PVA hydrogels in the realm of flexible electronics. They could be used to create innovative and versatile devices with stimuli-responsive fluorescence properties.

An Asymmetric NIR-II Organic Fluorophore with an Ultra-Large Stokes Shift for Imaging-Guided and Targeted Phototherapy.

NIR-II imaging-guided phototherapy is an attractive, yet challenging, tumor treatment strategy. By monitoring the accumulation of phototherapy reagents at the tumor site through imaging and determining the appropriate therapy window, the therapeutic effect could be significantly improved. Probes with NIR-II (1000-1700 nm) fluorescence emission and a large Stokes shift hold great promise for fluorescence imaging with deep penetration, minimized self-quenching, and high spatiotemporal resolution. However, due to the lack of a suitable molecular framework, the design of a simple small-molecule dye with a large Stokes shift and NIR-II fluorescence emission has rarely been reported. Herein, we prepare an asymmetric D-π-A type NIR-II fluorescence probe (TBy). The probe is incapsulated in an amphiphilic polymer and modified with a fibronectin targeting peptide CREKA, which could recognize the fibrin-fibronectin complex overexpressed in multiple malignant tumors. The nanoparticles thus constructed (TByC-NPs) have maximum fluorescence emission at 1037 nm with a large Stokes shift of 426 nm, which is the largest Stokes shift among organic NIR-II fluorescent dyes reported in the literature. The TByC-NPs exhibit a good NIR-II imaging performance, active tumor targeting, and good photothermal and photodynamic capabilities. In vitro and in vivo studies verify that the TByC nanoplatform shows outstanding biocompatibility for NIR-II imaging-guided phototherapy and provides an excellent antitumor effect.

Microstructured large-area photoconductive terahertz emitters driven at high average power.

Emitters based on photoconductive materials excited by ultrafast lasers are well-established and popular devices for THz generation. However, so far, these emitters - both photoconductive antennas and large area emitters - were mostly explored using driving lasers with moderate average powers (either fiber lasers with up to hundreds of milliwatts or Ti:Sapphire systems up to few watts). In this paper, we explore the use of high-power, MHz repetition rate Ytterbium (Yb) based oscillator for THz emission using a microstructured large-area photoconductive emitter, consist of semi-insulating GaAs with a 10 × 10 mm2 active area. As a driving source, we use a frequency-doubled home-built high average power ultrafast Yb-oscillator, delivering 22 W of average power, 115 fs pulses with 91 MHz repetition rate at a central wavelength of 516 nm. When applying 9 W of average power (after an optical chopper with a duty cycle of 50%) on the structure without optimized heatsinking, we obtain 65 µW THz average power, 4 THz bandwidth; furthermore, we safely apply up to 18 W of power on the structure without observing damage. We investigate the impact of excitation power, bias voltage, optical fluence, and their interplay on the emitter performance and explore in detail the sources of thermal load originating from electrical and optical power. Optical power is found to have a more critical impact on large area photoconductive emitter saturation than electrical power, thus optimized heatsinking will allow us to improve the conversion efficiency in the near future towards much higher emitter power. This work paves the way towards achieving hundreds of MHz or even GHz repetition rates, high-power THz sources based on photoconductive emitters, that are of great interest for example for future THz imaging applications.

Emerging MXene-based electrocatalysts for efficient nitrate reduction to ammonia: recent advance, challenges, and prospects

Ammonia (NH3) plays an irreplaceable role in traditional agriculture and emerging renewable energy. Its preparation in industry mainly relies on the energy-intensive Haber-Bosch process, which is associated with high energy consumption and large CO2 emissions. Recently, the nitrate reduction reaction (NO3-RR) driven by renewable energy has received extensive attention. This reaction can efficiently synthesize NH3 with water as a hydrogen source and NO3- as a nitrogen source under mild conditions, which is conducive to reducing energy consumption and promoting the carbon cycle. It is well known that the properties of electrocatalysts determine the performance of NO3-RR. As an emerging two-dimensional material, MXenes (transition metal carbides/nitrides/carbon nitrides) possess excellent electrical conductivity, large specific surface area and controllable surface functional groups, which shows great application potential in the field of NO3-RR. Herein, this review summarized the structure, properties and synthesis strategies of MXenes to elucidate the possibilities from foundation to application. Then, the latest research progress in applying MXene-based electrocatalysts to NO3-RR was summarized and the applicability of different NH3 detection methods was analyzed. Finally, the present challenges and future prospects of NO3-RR were presented. This review aimed to provide thoughtful insights into the rational design of MXene-based electrocatalysts for sustainable NH3 synthesis.

Atmospheric emissions of hexachlorobutadiene in fine particulate matter from industrial sources

Hexachlorobutadiene (HCBD) is a concerning chemical that is included in the United States Toxic Substances Control Act, and the Stockholm Convention. Knowledge of the sources of HCBD is insufficient and is pivotal for accurate inventory and implementing global action. In this study, unintentional HCBD release and source emission factors of 121 full-scale industrial plants from 12 industries are investigated. Secondary copper smelting, electric arc furnace steelmaking, and hazardous waste incineration show potential for large emission reductions, which are found of high HCBD emission concentrations of > 20 ng/g in fine particulate matter in this study. The highest HCBD emission concentration is observed for the secondary copper smelting industry (average: 1380 ng/g). Source emission factors of HCBD for the 12 industries range from 0.008 kg/t for coal fire power plants to 0.680 kg/t for secondary lead smelting, from which an estimation of approximately 8452.8 g HCBD emissions annually worldwide achieved. The carcinogenic risks caused by HCBD emissions from countries and regions with intensive 12 industrial sources are 1.0-80 times higher than that without these industries. These results will be useful for formulating effective strategies of HCBD control.

The potential of microalgae for carbon capture and sequestration

Microalgae have been highlighted as a contributor to CO2 sequestration due to their efficient photosynthetic system. However, calculations on their actual potential for CO2 sequestration are often lacking. Here, we calculated the potential of microalgae for the capture of CO2 by integrating it with a large emitter (gas-based energy plant) and a low emitter (dairy farms), and also discussed if such integrated systems can be considered as carbon sequesters given that the final use of the biomass often quickly releases the captured CO2. Moreover, the CO2 footprint of microalgal systems is highlighted as a critical point of attention for future developments. Such considerations are of utmost importance to avoid false promises that ultimately harm this sector, as large investments are made following untruthful claims that, when proven wrong, result in a loss of interest. Finally, key definitions are proposed to improve clarity and help in such discussions.

Near-infrared fluorescent probe with large Stokes shift and long emission wavelength for rapid diagnosis of lung cancer via aerosol inhalation delivery

Near-infrared fluorescent probe with large Stokes shift and long emission wavelength for rapid diagnosis of lung cancer via aerosol inhalation delivery

SOFIA/HAWC+ Far-infrared Polarimetric Large Area CMZ Exploration Survey. II. Detection of a Magnetized Dust Ring in the Galactic Center

We present the detection of a magnetized dust ring (M0.8–0.2) in the central molecular zone (CMZ) of the Galactic center. The results presented in this paper utilize the first data release of the Far-Infrared Polarimetric Large Area CMZ Emission (FIREPLACE) survey (i.e., Paper I of this series). The FIREPLACE survey is a 214 μm polarimetric survey of the Galactic center using the SOFIA/HAWC+ telescope. The M0.8–0.2 ring is a region of gas and dust that has a circular morphology with a central depression. The dust polarization in the M0.8–0.2 ring implies a curved magnetic field that traces the ring-like structure of the cloud. We posit an interpretation in which an expanding shell compresses and concentrates the ambient gas and magnetic field. We argue that this compression results in strengthening of the magnetic field, as we infer from the observations toward the interior of the ring.

Wavelength-tunable photoluminescence of CsPbBr3 microcrystal via in situ halogen doping

Lead halide perovskite semiconductors have received significant attention in recent years as promising candidates for optoelectronic applications. Their controllable bandgap in nanostructures (nanocrystals, nanowires) has been widely and successfully investigated. Intentionally manipulating the atomic behavior with dopants in their macroscopic structure with high quality and stability is still challenging. We studied the crystal structure and photoluminescence (PL) behavior of the anion (Cl) doped CsPbBr3 microcrystals. The doped microcrystal with a low doping concentration has shown a large wavelength-tunable PL emission from 535 nm to 457 nm. Two separate emission peaks (blue and green) are carefully studied in the excitation power dependent PL spectra. The doping and excitation endow the perovskite microcrystal adjustable PL emission band and peak intensities, which may serve as a new degree of manipulation freedom in the color-tunable display and functional optoelectronics.

Large greenhouse gases emissions from lakes in Inner Mongolia, China

Lakes are important component of the regional carbon cycle and a significant sources of greenhouse gases (GHGs) to the atmosphere. However, the regional variations in carbon dioxide (CO2) and methane (CH4) emissions, as well as the factors regulating these emissions are poorly constrained. To investigate the regional GHG emission from lakes and their potential influencing factors, we conducted field measurements in 13 lakes in Inner Mongolia from July to August 2020. We found that the studied lakes were predominantly sources of atmosphere CO2 and CH4. The CO2 partial pressure (pCO2) exhibited supersaturation in 80 % of samplings, but all samplings of CH4 partial pressure (pCH4) showed supersaturation. Moreover, the average pCH4 is 40 times greater than that in the atmosphere. The lakes emitted substantial amounts CO2 and CH4 with average values of 25.8 ± 4.9 mmol m−2 d−1 and 2.1 ± 0.3 mmol m−2 d−1, respectively. At the regional scale, the dynamics of pCO2 and pCH4 are regulated by combination of various environmental factors. CO2 emissions from studied lakes decreased with the catchment net primary productivity (NPP), normalized difference vegetation index (NDVI), and nighttime lights which is indicative of urbanization. Conversely, CH4 fluxes increased with NPP, NDVI, and nighttime lights. We conclude that terrestrial carbon-cycling related variables and human activities significantly affect CO2 and CH4 emissions from lakes by transporting different nutrients, but they show opposite trends. Our results also exhibited that the freshwater lakes are the main contributors of CH4, while saline lakes are the main contributors of CO2. We suggest that increased human activity leads to changes in terrestrial carbon-cycle related processes which affects lake carbon emissions by altering the amount of nutrients input to the lakes.

The origin of large emission line widths in massive galaxies at redshifts z ∼ 3–4

The origin of large emission line widths in massive galaxies at redshifts <i>z</i> ∼ 3–4