Neutral Emission Research Articles

Sphagnum mosses, the impact of disturbances and anthropogenic management actions on their ecological role in CO2 fluxes generated in peatland ecosystems.

Mosses of the genus Sphagnum are the dominant vegetation in most pristine peatlands in temperate and high-latitude regions. They play a crucial role in carbon sequestration, being responsible for ca. 50% of carbon accumulation through their active participation in peat formation. They have a significant influence on the dynamics of CO2 emissions due to an efficient maximum potential photosynthetic rate, lower respiration rates, and the production of a recalcitrant litter whose decomposition is gradual. However, various anthropogenic disturbances and land use management actions that favor its reestablishment have the potential to modify the dynamics of these CO2 emissions. Therefore, the objective of this review is to discuss the role of Sphagnum in CO2 emissions generated in peatland ecosystems, and to understand the impacts of anthropogenic practices favorable and detrimental to Sphagnum on these emissions. Based on our review, increased Sphagnum cover reduces CO2 emissions and fosters C sequestration, but drainage transforms peatlands dominated by Sphagnum into a persistent source of CO2 due to lower gross primary productivity of the moss and increased respiration rates. Sites with moss removal used as donor material for peatland restoration emit twice as much CO2 as adjacent undisturbed natural sites, and those with commercial Sphagnum extraction generate almost neutral CO2 emissions, yet both can recover their sink status in the short term. The reintroduction of fragments and natural recolonization of Sphagnum in transitional peatlands, can reduce emissions, recover, or increase the CO2 sink function in the short and medium term. Furthermore, Sphagnum paludiculture is seen as a sustainable alternative for the use of transitional peatlands, allowing moss production strips to become CO2 sink, however, it is necessary to quantify the emissions of all the components of the field of production (ditches, causeway), and the biomass harvested from the moss to establish a final closing balance of C.

Evidence for Charging and Discharging of MoS2 and WS2 on Mica by Intercalating Molecularly Thin Liquid Layers

Transition metal dichalcogenides (TMDCs) are often mechanically exfoliated on mica and examined under ambient conditions. It is known that above a certain relative humidity, a molecularly thin layer of water intercalates between the mica and the TMDC. Herein, the effect of molecularly thin liquid layers on the optical spectra of MoS2 and WS2 exfoliated on dry mica and exposed to the vapors of water, ethanol, and tetrahydrofuran (THF) is investigated. Photoluminescence and differential reflectance (ΔR/R) spectra on the TMDCs on dry mica show dominant trion emission due to n‐doping. Intercalation of water removes charge doping and results in purely neutral exciton emission, while an ethanol layer, which can be reversibly exchanged with water, does not completely suppress charge. Similarly, THF intercalates between TMDC and mica, as shown by atomic force microscopy, but it does not suppress the charging of mica. In MoS2 bi‐ and trilayers, an intercalated water layer leads to a near doubling of the intensity of the indirect band transition. The described charging/discharging of TMDCs by molecular thin liquid layers can provide important clues to better control the optical properties of TMDCs under environmental conditions.

Group contribution method for predicting viscosity of alkyl esters and biodiesel

People will need to use energy from sustainable sources more frequently to achieve neutral carbon emissions in the energy context transition in the close future. Biofuels are an interesting alternative to replace petroleum derived oils. Biodiesel is a mixture of alkyl esters got through vegetable oils or animal fats transesterification. The physical and chemical properties knowledge of biodiesel is essential to define its quality and well performance in automotive engines. Viscosity is one of the most important properties of biodiesel because it plays a significant role in the combustion and transport processes. This study compiled viscosity data from literature for a total of 45 alkyl esters, encompassing 931 experimental data points, as well as 24 biodiesel samples and 32 biodiesel binary mixtures, accounting for 566 experimental data points. These compiled viscosities were then utilized to assess the effectiveness of a group contribution approach, yielding a viscosity prediction with an average absolute deviation (AAD) of 4.37 % and a correlation coefficient (R) of 0.9942. Furthermore, the Grunberg-Nissan mixing rule was employed to estimate the viscosity of biodiesel, resulting in an AAD and R of 5.89 % and 0.9859, respectively.Finally, the method proposed here is easy to implement and useful for many applications.

(Invited) Electroluminescence from Single-Walled Carbon Nanotubes with Quantum Defects

Individual single-walled carbon nanotubes with covalent sidewall defects have emerged as a new class of photon sources whose photoluminescence spectra can be tailored by the carbon nanotube chirality and the attached functional group/molecule. Here we present electroluminescence spectroscopy data from single-tube devices based on (7,5) carbon nanotubes, functionalized with dichlorobenzene molecules, and wired to graphene electrodes. We observe electrically generated, defect-induced emissions that are controllable by electrostatic gating and strongly red-shifted compared to emissions from pristine nanotubes. The defect-induced emissions are assigned to excitonic and trionic recombination processes by correlating electroluminescence excitation maps with electrical transport and photoluminescence data. At cryogenic conditions additional, gate-dependent emission lines appear which are assigned to phonon-assisted hot-exciton electroluminescence from quasi-levels. Similar results were obtained with functionalized (6,5) nanotubes. We also compare functionalized (7,5) electroluminescence data with photoluminescence of pristine and functionalized (7,5) nanotubes redox-doped using gold(III) chloride solution. This work shows that electroluminescence excitation is selective toward neutral defect-state configurations with the lowest transition energy, which in combination with gate-control over neutral versus charged defect-state emission leads to high spectral purity.Reference: Min-Ken Li et al., ACS Nano 2022 (doi: 10.1021/acsnano.2c03083) Figure 1

Application of a hyperspectral camera for in situ plasma-material interaction studies at the linear plasma device PSI-2.

A hyperspectral camera (HSC-type Specim IQ) has been applied at the linear plasma device PSI-2 under steady-state conditions. The camera has the capacity of hyperspectral imaging (HSI) with the dimension of a data array 512 × 512 × 204 (x, y, λ) covering the spectral span from 400 to 1000nm with moderate average spectral resolution (FWHM ∼7nm). After radiometric calibration and background/continuum emission subtraction, two main applications of the camera, (i) plasma diagnostics in helium (He) plasmas and (ii) plasma-material interaction studies with tungsten (W) targets in neon (Ne) plasmas, have been carried out. The measurements were complemented by a movable Langmuir double probe system (LP) measuring electron temperature (Te) and electron density (ne) in radial direction r and a fiber-coupled cross-dispersion spectrometer with high spectral resolution (Spectrelle) recording neutral He, W, and Ne emission lines over the full plasma column. (i) Two-dimensional (2D) imaging of Te and ne radial profiles in axial direction z of the He plasma column were for the first time obtained by the regression analysis of Te and ne (from LP) and six He I line ratios (from HSC). The spatially resolved plasma parameters covered in these studies range between Te ∼ 0.8-13.4eV and ne ∼ 0.2 × 1018-3.9 × 1018m-3 and permit a reconstruction of the plasma conditions in PSI-2 in 2D without LP perturbation. (ii) W sputtering was studied in situ in Ne plasmas exposing W target samples (negatively biased at 100V) under perpendicular Ne plasma impact. Simultaneously, the 2D distributions of W (W I line at 429.5nm) in front of the target and the 2D Ne plasma distribution (Ne I line at 703.2nm) were recorded with complete spectral separation as confirmed by the Spectrelle spectrometer. This permits the simultaneous measurement of the neutral W penetration and its angular distribution induced in the sputtering process and of the impinging plasma distribution. The HSI technique offers, despite a few technical drawbacks, such as the moderate spectral resolution and poor time resolution, a new possibility to distinguish multiple emission lines from plasma and impurities and complements the portfolio of existing Optical Emission Spectroscopy techniques, providing a good compromise regarding spectral, spatial, and temporal resolution.

Optical emission features of laterally colliding laser-produced plasmas at different ambient pressures

Optical emission characteristics of seed plasma and stagnation region of laterally colliding laser produced aluminium plasmas are investigated under various background gas pressures of air and argon ambient. The intensity of ionic and neutral emissions from seed plasma region increases with the increase of ambient pressure. Neutral emission from the stagnation region increases whereas the intensity of ionic emission decreases with the increase of ambient pressure. Decrease of collision rate between the seed plasmas results in the decrease of ionic emission from the interaction region. For higher inter seed plume separation, maximum spectral emission from stagnation region is observed at an intermediate pressure range of 10−2 mbar. Emission intensity and the life time of both ionic and neutral emission are greater in heavier Ar ambient. In the case of seed plasmas, the electron density decreases whereas the electron temperature increases with the increase of ambient gas pressure and is greater in Ar ambient. The variations of plasma parameters are quite less in stagnation region.

Early Hard X-Rays from the Nearby Core-collapse Supernova SN 2023ixf

We present NuSTAR observations of the nearby SN 2023ixf in M101 (d = 6.9 Mpc) that provide the earliest hard X-ray detection of a nonrelativistic stellar explosion to date at δ t ≈ 4 days and δ t ≈ 11 days. The spectra are well described by a hot thermal bremsstrahlung continuum with T > 25 keV shining through a thick neutral medium with a neutral hydrogen column that decreases with time (initial N Hint = 2.6 × 1023 cm−2). A prominent neutral Fe Kα emission line is clearly detected, similar to other strongly interacting supernovae (SNe) such as SN 2010jl. The rapidly decreasing intrinsic absorption with time suggests the presence of a dense but confined circumstellar medium (CSM). The absorbed broadband X-ray luminosity (0.3–79 keV) is L X ≈ 2.5 × 1040 erg s−1 during both epochs, with the increase in overall X-ray flux related to the decrease in the absorbing column. Interpreting these observations in the context of thermal bremsstrahlung radiation originating from the interaction of the SN shock with a dense medium we infer large particle densities in excess of n CSM ≈ 4 × 108 cm−3 at r < 1015 cm, corresponding to an enhanced progenitor mass-loss rate of M ⊙ yr−1 for an assumed wind velocity of v w = 50 km s−1.

Warm to neutral white light emissions from Dy3+–Eu3+ co-doped glass ceramics containing NaBSiO4 crystalline phase for W-LEDs applications

This paper reports on the structural, optical and luminescence studies of Dy3+–Eu3+ co-doped glass ceramics that are obtained via thermal treatment method. The initial confirmation on glass ceramics with the formation of NaBSiO4 crystalline phase was made through XRD study. The FTIR study showed the vibrations of network formers (B2O3, SiO2) and other functional groups. The quantity of non-bridging oxygens (NBOs) are increased in the glass ceramics with increase in annealing temperature. The absorption spectra (UV–visible-NIR) showed the possible transitions of Dy3+ and Eu3+ ions in the glass ceramics. A red-shift in the absorption band-edge and reduction in the optical band gap values were obtained for glass ceramics owing to their heating temperatures. Photoluminescence studies showed the excitations of Dy3+ and Eu3+ ions under 575 nm and 613 nm emission wavelengths. The obtained NaBSiO4 crystalline phase in the glass ceramics has enhanced the luminescence intensity, and lifetimes of Dy3+ and Eu3+ ions compared to unheated precursor glass when excited under 350 nm and 393 nm. Color chromaticity diagram and correlated color temperature (CCT) values showed a shift in the color of light from warm white of precursor glass to neutral white of glass ceramics. The overall results justify the possibility of considering the Dy3+-Eu3+ co-doped glass ceramics as efficient materials for solid-state lighting applications like W-LEDs.

Solar-wind electron precipitation on weakly magnetized bodies: The planet Mercury

Rocky objects in the Solar System (such as planets, asteroids, moons, and comets) undergo a complex interaction with the flow of magnetized, supersonic plasma emitted from the Sun called solar wind. We address the interaction of such a flow with the planet Mercury, considered here as the archetype of a weakly magnetized, airless, telluric body immersed in the solar wind. Due to the lack of dense atmosphere, a considerable fraction of solar-wind particles precipitate on Mercury. The interaction processes between precipitating electrons and other nonionized parts of the system remain poorly understood. Shading light on such processes is the goal of this work. Using a 3D fully kinetic self-consistent plasma model, we show for the first time that solar-wind electron precipitation drives (i) efficient ionization of multiple neutral exosphere species and (ii) emission of X-rays from the surface of the planet. We conclude that, compared to photoionization, electron-impact ionization should not be considered a secondary process for the H, He, O, and Mn exosphere. Moreover, we provide the first, independent evidence of X-ray aurora-like emission on Mercury using a numerical approach.

Ionization of sputtered material in high power impulse magnetron sputtering plasmas—comparison of titanium, chromium and aluminum

The ionization of sputtered species in high power impulse magnetron sputtering of titanium, chromium, and aluminum targets is analyzed using Abel-inverted spectroscopic imaging to locate the position of ionization. From the spatial emission of neutrals, it is deduced that most of the sputtered titanium particles become ionized within 0.5 mm distance from the target, whereas sputtered aluminum or chromium can travel much further through the discharge before ionization occurs. Probe measurements reveal the reason for this difference to be the unusually high electron temperature of around 4.5 eV for titanium compared to 2.6 eV and 1.5 eV for aluminum and chromium as the target material, respectively. These probe measurements are then compared to a global model derived from the ionization region model. Excellent agreement between model and measurements can be reached, but only if the transport physics for the confinement of the species is adjusted. Using the model, the difference between the three discharges can be traced back to be mostly caused by the sputter yield. Thus, we propose that ionization in discharges with low-yield materials should generally be expected to occur closer to the target surface, leading the ions to be affected more strongly by the electric field across the magnetic trap region, resulting in a more severe deposition rate loss compared to high-yield materials.

Determination of the Time and Coordinates Required for Measuring the Milky Way’s Rotation Curve Using BURT in 2023

Baghdad University Radio Telescope (BURT) is a 3 meter radio telescope that was installed in the main campus of the University of Baghdad in Jadiriyah. Radio telescopes, in general, offer a wide range of applications in radio astronomy, which are usually used to detect the neutral hydrogen emission line at a wavelength of 21 cm. One of the key applications of BURT is to observe the Milky Way galaxy and to determine its rotation curve. However, performing such observations requires accurate determination of the appropriate observing time as well as the coordinates. This paper focuses on how the observing time and coordinates are calculated correctly and accurately. The horizontal coordinate that corresponds to the galactic coordinates (b=0° and 0° ≤ l ≤ 90°) in every single day of 2023 at 10 am have been calculated using a c++ code that has been written for the purpose of this work. The results showed that the appropriate time for observing the Milky Way using BURT in 2023 is during January, February, March, November and December of 2023. The medians of altitude during those months are 50.9798°, 62.7919°, 50.6198°, 9.6562° and 30.5041°, respectively. During those months, the altitude is found, in general, larger than zero which means that the galactic position is above the horizon.

Constraints on the IBEX Ribbon’s Origin from Its Evolution over a Solar Cycle

In 2009, the Interstellar Boundary Explorer (IBEX) discovered a narrow “ribbon” of energetic neutral atom emissions across the sky with properties correlated with the solar wind latitudinal structure and the interstellar magnetic field draped around the heliosphere. It is widely believed that the ribbon is formed from the escape of heliospheric ENAs into the local interstellar medium and their eventual return as secondary ENAs. However, there is no consensus on the rate of pitch angle scattering of these PUIs before they become secondary ENAs. We test two opposing limits of scattering rates (“weak” versus “strong”) by solving a time-dependent model of the ribbon that evolves with the solar cycle, and we compare them to IBEX observations over 2009–2019. First, we find that both models qualitatively reproduce the evolution of IBEX fluxes for most of the data set, with a few exceptions, although the strong (or “spatial retention”) scattering model greatly underestimates the observed fluxes. Regardless, time dependence of fluxes cannot distinguish these models. Second, the ribbon’s geometric properties, i.e., its center and radius, are significantly different between the models. The spatial retention model reproduces the observed ribbon centers as a function of energy and time slightly better than the weak scattering model, and the spatial retention model reproduces the observed ribbon radius over energy and time almost perfectly, whereas the weak scattering model compares poorly. Our analysis favors the spatial retention mechanism as the source of the IBEX ribbon, but it requires modification to increase the flux of ENAs observed at 1 au.

The Diffuse Ionized Gas Halo of the Large Magellanic Cloud

The Large Magellanic Cloud (LMC) has an extensive Hα emission halo that traces an extended, warm ionized component of its interstellar medium. Using the Wisconsin Hα Mapper telescope, we present the first kinematic Hα survey of an extensive region around the LMC, from (ℓ, b) = (264.°5, − 45.°5) to (295.°5, − 19.°5), covering +150 ≤ v LSR ≤ + 390 km s−1. We find that ionized hydrogen exists throughout the galaxy and extends several degrees beyond detected neutral hydrogen emission as traced by 21 cm in current surveys. Using the column density structure of the neutral gas and stellar line-of-sight depths as a guide, we estimate the upper limit mass of the ionized component of the LMC to be roughly M ionized ≈ (0.6–1.8) × 109 M ☉, which is comparable to the total neutral atomic gas mass in the same region (M neutral ≈ 0.76–0.85 × 109 M ☉). Considering only the atomic phases, we find M ionized/M ionized+neutral, to be 46%–68% throughout the LMC and its extended halo. Additionally, we find an ionized gas cloud that extends off of the LMC at (ℓ, b) ≈ (285°, − 28°) into a region previously identified as the Leading Arm complex. This gas is moving at a similar line-of-sight velocity as the LMC and has M ionized/M ionized+neutral = 13%–51%. This study, combined with previous studies of the SMC and extended structures of the Magellanic Clouds, continues to suggest that warm, ionized gas is as massive and dynamically important as the neutral gas in the Magellanic System.

Comparing the kinetics of ionized and neutral atoms from single and multi-element laser-produced plasmas

Kinetics of ion and neutral atom emission features were compared for nanosecond laser-produced plasmas generated from several metal targets (i.e., Al, Ti, Zr, Nb, Ta) and an alloy containing all of these as principal alloying elements. Plasmas were produced by focusing 6 ns, 1064 nm pulses from an Nd:YAG laser on the targets of interest in a vacuum. A Faraday cup was used for collecting ion temporal features while spatially and temporally resolved emission spectroscopy was used for measuring the optical time of flight of various neutral atomic transitions. Our results highlight that most probable ion and atom velocities decay with increasing atomic mass. Trends for ions from the alloy target represent a weighted average where all ions contribute. For both ions and atoms, velocities decrease with increasing heat of vaporization and melting temperature, consistent with the thermal mechanisms that contribute to nanosecond laser ablation. Kinetic energies for neutral atoms from pure metal targets have some variability with atomic mass, whereas kinetic energies for atoms from the alloy target are more similar. These more similar kinetic energies observed for neutral atoms in the multi-element plasma may be attributed to collisions between species from all elements in the Knudsen layer.

Constraints on Europa’s Water Group Torus from HST/COS Observations

In situ plasma measurements as well as remote mapping of energetic neutral atoms around Jupiter provide indirect evidence that an enhancement of neutral gas is present near the orbit of the moon Europa. Simulations suggest that such a neutral gas torus can be sustained by escape from Europa’s atmosphere and consists primarily of molecular hydrogen, but the neutral gas torus has not yet been measured directly through emissions or in situ. Here we present observations by the Cosmic Origins Spectrograph (COS) of the Hubble Space Telescope (HST) from 2020 to 2021, which scanned the equatorial plane between 8 and 10 planetary radii west of Jupiter. No neutral gas emissions are detected. We derive upper limits on the emissions and compare these to modeled emissions from electron impact and resonant scattering using a Europa torus Monte Carlo model for the neutral gases. The comparison supports the previous findings that the torus is dilute and primarily consists of molecular hydrogen. A detection of sulfur ion emissions radially inward of the Europa orbit is consistent with emissions from the extended Io torus and with sulfur ion fractional abundances as previously detected.

A Search for OH 18 cm Emission from Intermediate-velocity Gas at High Galactic Latitudes

We present search results of 22 high-latitude (∣b∣ > 25°) sightlines for OH 18 cm emission using the 305 m radio telescope at the Arecibo Observatory. These sightlines appear in neutral hydrogen emission at intermediate velocities −90 ≤ V LSR ≤ −20 km s−1 and are predicted to have a sufficient molecular composition so as to be detectable in molecular emission. Such objects, known as intermediate-velocity molecular clouds (IVMCs), have historically been detected through 12CO emission. Recent studies indicate that IVMCs may be widespread in the galaxy and have important implications for models of the interstellar medium and star formation. However, we report nondetections of OH emission toward the 22 sightlines and provide stringent upper limits on the OH column density. Using available H i and A v data in combination with existing state-of-the-art PDR models, we estimate H2 column densities and find that they are more than an order of magnitude lower than the predicted values. We also find that the hydrogen volume density of these clouds is ≲25 cm−3. In addition, we discuss the known IVMCs with previous 12CO detections in the context of the PDR models. Our analysis of these clouds indicates that the structure of molecular material in IVMCs is morphologically clumpy. These results motivate the need for future sensitive, on-the-fly searches (rather than targeted searches) for CO emission from IVMCs with resolutions on the order of ∼1′. High angular resolution (∼1′) H i and A v data will also be helpful to better constrain the structure and composition of IVMCs.

Individually addressable and spectrally programmable artificial atoms in silicon photonics

A central goal for quantum technologies is to develop platforms for precise and scalable control of individually addressable artificial atoms with efficient optical interfaces. Color centers in silicon, such as the recently-isolated carbon-related G-center, exhibit emission directly into the telecommunications O-band and can leverage the maturity of silicon-on-insulator photonics. We demonstrate the generation, individual addressing, and spectral trimming of G-center artificial atoms in a silicon-on-insulator photonic integrated circuit platform. Focusing on the neutral charge state emission at 1278 nm, we observe waveguide-coupled single photon emission with narrow inhomogeneous distribution with standard deviation of 1.1 nm, excited state lifetime of 8.3 ± 0.7 ns, and no degradation after over a month of operation. In addition, we introduce a technique for optical trimming of spectral transitions up to 300 pm (55 GHz) and local deactivation of single artificial atoms. This non-volatile spectral programming enables alignment of quantum emitters into 25 GHz telecommunication grid channels. Our demonstration opens the path to quantum information processing based on implantable artificial atoms in very large scale integrated photonics.

How can the health sector support Canada's net-zero ambition?

How can the health sector support Canada's net-zero ambition? As the Honourable Steven Guilbeault has clarified, if Canada is to achieve net-zero emissions by 2050, we will need “all-hands-on-deck.” Fiona A. Miller, Professor &amp; Director at the Centre for Sustainable Health Systems, University of Toronto in Canada, explores Canada's net-zero ambition, looking in particular at the role of the health sector in decarbonisation. However, achieving Canada's net-zero ambition of neutral greenhouse gas emissions by 2050 is a complex and challenging goal that requires a whole-of-society approach. The initiative calls for all companies operating in Canada to voluntarily commit to developing and implementing a plan to achieve Canada's net-zero ambition, supported by clear technical standards and public reporting requirements. So far, the 2030 emissions reduction plan aims at “clean air and good jobs, a healthy environment and a strong economy.” The problem lies in the significant gap in the Federal Government's plans: the health sector's direct contribution to the net-zero transition. Healthcare is a highly resource-intensive and polluting industry, estimated at 5.2% of global emissions and increasing. Moreover, Canada's health sector is estimated to be the second most carbon-intensive in the world after that of the U.S. There is clearly work to do, Professor Miller evaluates.

Persistent room-temperature valley polarization in graphite-filtered WS2 monolayer

Transition metal dichalcogenide (TMD) monolayers (1L) in the 2H-phase are two-dimensional semiconductors with two valleys in their band structure that can be selectively populated using circularly polarized light. The choice of the substrate for monolayer TMDs is an essential factor for the optoelectronic properties and for achieving a high degree of valley polarization at room temperature (RT). In this work, we investigate the RT valley polarization of monolayer WS2 on different substrates. A degree of polarization of photoluminescence (PL) in excess of 27% is found from neutral excitons in 1L-WS2 on graphite at RT, under resonant excitation. Using chemical doping through photochlorination we modulate the polarization of the neutral exciton emission from 27% to 38% for 1L-WS2/graphite. We show that the valley polarization strongly depends on the interplay between doping and the choice of the supporting layer of TMDs. Time-resolved PL measurements, corroborated by a rate equation model accounting for the bright exciton population in the presence of a dark exciton reservoir support our findings. These results suggest a pathway towards engineering valley polarization and exciton lifetimes in TMDs, by controlling the carrier density and/or the dielectric environment at ambient conditions.

Evaluation methods, progress and prospect of carbon budget system under dual carbon background

In September 2020, China declared to it to achieve carbon peaks by 2030 and carbon neutralization by 2060. Based on the literature review, this paper analyzes the current status of the carbon revenue and expenditure system. It expouds on the methods and progress of the carbon revenue and expenditure system. On this basis, some suggestions are put forward from four aspects: primary data, accounting methods, and technical means. The current research progress and existing problems were reviewed, and suggestions for future research ideas were put forward, in order to provide a methodology reference for accurate estimation of carbon sinks in terrestrial ecosystems in China, and provide scientific support for the development of carbon neutral emission reduction policies in China.