High Temperature Precipitation Research Articles

Checklist of Ferns in Mt. Mariveles, Bataan, Philippines

A checklist of fern species in Mt Mariveles, Bataan was provided in two trails of the said mountain, Tarak ridge and Pantingan peak from 400 masl to 1000 masl with information in their growth forms, endemicity and conservation status. The collected specimens were identified and evaluated based on their conservation status. There were 28 taxa, 20 genera in 14 families of ferns observed at Mt. Mariveles Bataan. Among the 14 families, Aspleniaceae has the most numbered of species consisting of 5 taxa. There are 20 taxa of ferns, 14 genera in 10 families that are found in Tarak of Mt Mariveles while 11 taxa and 9 genera in 10 families were recorded in Pantingan of Mt Mariveles. More ferns were observed in Papaya River in Tarak and in 800 to 1000 masl in Pantingan. Mid-elevation forests had the highest maximum fern richness. It results from the combination of high humidity, precipitation, and moderate temperatures. The growth form of collected ferns are mostly epiphytic. Based on their conservation status there are two species that are Least Concern (LC) these are Pteridium aquilinum and Dicranopteris linearis while Angiopteris evecta of Marattiaceae was considered as Other threatened species (OT).

The effect of climate change on spatio-temporal activity in burrowing frogs of the Smilisca group

Measuring the potential effects of future climate changes on the spatio-temporal variance of optimal conditions for seasonal species is a key conservation issue. This study assesses the impact of climate change on the spatial and temporal patterns of optimal conditions for activity in two burrowing frogs, Smilisca fodiens and S. dentata. Ecological Niche Modeling was used to implement niche seasonality models, with calibration performed during the peak activity (July). These models were then transferred to current and future conditions for the remainder of the year, predicting future scenarios up to 2070 with an intermediate trajectory greenhouse gas concentration of 4.5 W/m2. Climate change transferability was assessed for four potential scenarios: 1) high precipitation and low temperature, 2) high precipitation and high temperature, 3) low precipitation and low temperature, and 4) low precipitation and high temperature. We examined the impact across future projected areas and analyzed geographic change trends based on latitude, longitude, and elevation. For both species, the best scenario would involve increased precipitation in the future. However, the worst-case would be a combination of reduced precipitation and higher temperatures. Due to large area loss, northern populations of S. fodiens may be highly vulnerable. Concerning S. dentata, the outlook is worrisome, with all known populations experiencing losses in most months. Area gains may not help either species since they tend to occur at elevations above their known ranges. Using a seasonal approach in spatio-temporal analysis enhances comprehension of the behavioral adaptations of seasonal species and their vulnerability to current and future climatic variations.

A secondary high-temperature precursor of the θ′-phase in Al-Cu-(Sc) alloys

The Al-Cu alloy is a historical model alloy system in the physical metallurgy of engineering aluminum alloys. Nevertheless, a few fundamental phenomena of phase transformation occurring in this simple alloy are still not adequately understood. Among all, for instance, the formation mechanisms of its key hardening θ′-phase remain mysterious. There is strong evidence that θ′-precipitates can form from a different high-temperature precipitation pathway, while their formation mechanism via the conventional pathway well-known since 1938 remains to be clarified. Using state-of-the-art electron microscopy, here we report a secondary high-temperature precipitation pathway of θ′-precipitates. It is demonstrated that led by a secondary high-temperature precursor, named θ′S-HTP, very fine θ′-precipitates can form in the undeformed bulk Al-Cu alloys at elevated temperatures (≥ 250 °C). Interestingly is that with Sc-microalloying the surviving rate of meta-stable θ′S-HTP precipitates increases drastically and the formed θ′-precipitates become much finer, significantly enhancing the alloys’ strength and thermal stability. It is also revealed that a θ′S-HTP precipitate can genetically evolve into a θ′-precipitate without having to change its morphology and orientation. Our study provides new insights into understanding the industry bulk alloys’ microstructures and properties.

Projection of extreme climate change in the Asian arid region and the Tibetan Plateau in the early and middle 21st century based on NEX-GDDP-CMIP6

In the context of global warming, it is anticipated that both the intensity and the frequency of future global extreme high precipitation (EHP) and extreme high temperature (EHT) events will increase. To evaluate the future extreme climate changes in the Asian arid region and Tibetan Plateau, this study applied the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) to assess the changes in EHP (Rx5d and R95pTOT) and EHT (TX90p and TXx) under different emission scenarios in the 21st century. Findings suggest that both the frequency and the intensity of the extreme indices will increase, exhibiting accelerated growth under higher emission scenarios, particularly under the SSP5-8.5 emission scenario. It is suggested that the growth of EHT and EHP in the early subperiod of the 21st century (2026–2045) will be relatively moderate, with small differences between different emission scenarios. However, by the middle subperiod of the 21st century (2041–2060), the differences between different emission scenarios will become larger than the 2035s and the growth will become more intense. In western central Asia, TX90p, TXx, Rx5d, and R95pTOT increase by 9.7%–14.2% (13.3%–24.7%), 1.3°C–1.7°C (1.6°C–2.7°C), 6.5%–8.9% (8.2%–8.8%), and 18.1%–27.0% (25.6%–30.0%) by the early (middle) subperiod; in eastern central Asia, TX90p, TXx, Rx5d, and R95pTOT increase 8.1%–12.0% (11.3%–21.1%), 1.4°C–1.8°C (1.9°C–2.9°C), 7.4%–9.7% (10.4%–13.8%), and 20.2%–29.3% (32.0%–40.8%) by the early (middle) subperiod; and over the Tibetan Plateau, TX90p, TXx, Rx5d, and R95pTOT increase 12.5%–17.4% (17.0%–31.0%), 1.2°C–1.5°C (1.6°C–2.5°C), 7.2%–10.0% (9.9%–15.0%), and 26.6%–33.1% (36.1%–55.3%) by the early (middle) subperiod.摘要近年来, 随着全球变暖, 大部分地区极端气候事件的风险都有所增加. 作为中国一带一路建设核心区域的亚洲干旱区和青藏高原区域面临着严峻的极端气候风险. 本文利用NEX-GDDP-CMIP6数据预估了未来21世纪早期 (2026–2045) 和中期 (2041–2060) 不同排放情景下亚洲干旱区和青藏高原相较气候参考期 (1995–2014) 极端高温指数和极端降水指数的变化. 预估结果显示, 在不同排放情景下极端高温指数和极端降水指数都有所上升, 且在SSP5-8.5情景下增长最多, 其中NEX-GDDP-CMIP6不同模式对极端高温指数的模拟一致性高于极端降水指数. 21世纪中期相比早期极端高温指数和极端降水指数的增长更加严重.

Predicted range expansion of Prostephanus truncatus (Coleoptera: Bostrichidae) under projected climate change scenarios.

The larger grain borer (Prostephanus truncatus [Horn] [Coleoptera: Bostrichidae]) is a wood-boring insect native to Central America and adapted to stored maize and cassava. It was accidentally introduced to Tanzania and became a pest across central Africa. Unlike many grain pests, P. truncatus populations can establish and move within forests. Consequently, novel infestations can occur without human influence. The objectives of our study were to (i) develop an updated current suitability projection for P. truncatus, (ii) assess its potential future distribution under different climate change scenarios, and (iii) identify climate variables that best inform the model. We used WALLACE and MaxEnt to predict potential global distribution by incorporating bioclimatic variables and occurrence records. Future models were projected for 2050 and 2070 with Representative Concentration Pathways (RCPs) 2.6 (low change) and 8.5 (high change). Distribution was most limited by high precipitation and cold temperatures. Globally, highly suitable areas (> 75%) primarily occurred along coastal and equatorial regions with novel areas in northern South America, India, southeastern Asia, Indonesia, and the Philippines, totaling 7% under current conditions. Highly suitable areas at RCPs 2.6 and 8.5 are estimated to increase to 12% and 15%, respectively, by 2050 and increase to 19% in 2070 under RCP 8.5. Centroids of highly suitable areas show distribution centers moving more inshore and away from the equator. Notably, the result is a range expansion, not a shift. Results can be used to decrease biosecurity risks through more spatially explicit and timely surveillance programs for targeting the exclusion of this pest.

Traces of Local Adaptive Acclimatization Response in the Tracheid Anatomical Traits between Dry and Wet Mesic Norway Spruce (Picea abies) Forests in Moravia, Czech Republic?

Norway spruce (Picea abies) forests in temperate zones are already reacting to short-term extreme summer heatwaves, threatening the vitality of trees and forest productivity, and can even lead to local and regional dieback events. Examining quantitative wood anatomy can provide helpful information in terms of understanding the physiology mechanisms and related responses of conifer trees to local environmental interactions in relation to tracheid adaptive capacity. This study analysed the tracheid functional anatomical traits (FATs) plasticity of six young Norway spruce trees growing in two mesic research plots with high annual precipitation (~43%) and air temperature differences during 2010–2017. The research plots are located in the sub-mountainous (Rájec Němčice) and mountainous (Bílý Kříž) belts of the Moravia region, Czech Republic. Vapour pressure deficit and cell wall reinforcement index (CWRI) were shown to be the most representative environmental parameters as proxies of dry conditions. Tracheid FATs indicated latewood phenological plasticity sensitivity, with more pronounced variability in the warmer and drier plots. Latewood tracheids of Norway spruce trees grown in the RAJ formed significantly thicker cell walls than BK during the studied period. The observed differences between the two research plots indicate additional support for tracheid cells’ hydraulic safety against cavitation and potential traces of adaptive acclimatization response.

Using ecological niche modelling to prioritise areas for conservation of the critically endangered Buffy-Headed marmoset (Callithrix flaviceps).

Endemic to the Atlantic Forest in Southeastern Brazil, the critically endangered Buffy-Headed marmoset (Callithrix flaviceps) is lacking the required attention for effective conservation. We modelled its ecological niche with the main objectives of (1) defining suitable habitat and (2) prioritising areas for conservation and/or restoration. The current geographical range of Callithrix flaviceps in the Atlantic Forest of Southeast Brazil. We used Ensemble Species Distribution Modelling to define current habitat suitability considering four climate and two landscape variables. To identify areas to prioritise for conservation and/or restoration, we predicted future habitat suitability considering the intermediate (RCP4.5) and extreme (RCP8.5) climate change scenarios for the years 2050 and 2070. Among the variables included to predict current species distribution, tree canopy cover, precipitation seasonality and temperature seasonality were the most important whereas digital elevation model and precipitation during the wettest month were the least important. Callithrix flaviceps was most likely to occur in areas with tree canopy cover >80%, high precipitation seasonality and temperature seasonality between 21 and 23°C. From the future suitability prediction maps, the Caparaó National Park stands out as a likely key area for the preservation of the species. Furthermore, high climatic suitability but low landscape suitability suggests that habitat restoration in 'Serra das Torres' (South of the current distribution area) might be a useful strategy. However, creating ecological corridors on the west side of Caparaó would be necessary to improve connectivity. More surveys within and beyond the current geographical range are required to define more precisely the distribution of the species. Our results support the notion that seasonality is important for Callithrix flaviceps and that as a montane species, it prefers colder environments and higher altitudes. Within both climate change scenarios, Caparaó National Park was predicted to be highly suitable, with a high probability of presence.

No-tillage enhances soil water storage, grain yield and water use efficiency in dryland wheat (Triticum aestivum) and maize (Zea mays) cropping systems: a global meta-analysis.

Climate change significantly affects crop production and is a threat to global food security. Conventional tillage (CT) is the primary tillage practice in rain-fed areas to conserve soil moisture. Despite previous research on the effect of tillage methods on different cropping systems, a comparison of tillage methods on soil water storage, crop yield and crop water use in wheat (Triticum aestivum ) and maize (Zea mays ) under different soil textures, precipitation and temperature patterns is needed. We reviewed 119 published articles and used meta-analysis to assess the effects of three conservation tillage practices (NT, no-tillage; RT, reduced tillage; ST, subsoil tillage), on precipitation storage efficiency (PSE), soil water storage at crop planting (SWSp), grain yield, evapotranspiration (ET) and water use efficiency (WUE) under varying precipitation and temperature patterns and soil textures in dryland wheat and maize, with CT as the control treatment. Conservation tillage methods increased PSE, SWSp, grain yield, ET and WUE in both winter wheat-fallow and spring maize cropping systems. More precipitation water was conserved in fine-textured soils than in medium-textured and coarse-textured soils, which improved ET. Conservation tillage increased soil water conservation and yield under high mean annual precipitation (MAP) and moderate mean annual temperature (MAT) conditions in winter wheat. However, soil water conservation and yield were greater under MAP <400mm and moderate MAT. We conclude that conservation tillage could be promising for increasing precipitation storage, soil water conservation and crop yield in regions with medium to low MAPs and medium to high MATs.

Diagenetic evolution and effects on reservoir development of the Dengying and Longwangmiao formations, Central Sichuan Basin, Southwestern China

The deeply buried Lower Cambrian Longwangmiao Formation and Upper Ediacaran Dengying Formation from the Sichuan Basin, China, have a total natural gas reserve up to 3 × 1012 m3. The complex diagenetic evolution and their impacts on the present-day reservoir quality have not been systematically elucidated, hampering the current exploration. Crucially, the integration and comparation diagenetic study on these two formations, which may be able to shed new lights on reservoir formation mechanism, are yet to be systemically evaluated. By compiling geochemistry data, including carbonate U-Pb ages and petrophysics data, coupled with new petrology, trace elements, and strontium isotope data, of various types of diagenetic carbonates, this study aims to decipher the potential links between diagenesis and reservoir development of both formations. Intriguingly, similar diagenetic sequence, which contains five distinctive dolomite phases, is established in both formations. The matrix dolomite (D1) and early dolomite cement (D2) were likely formed by reflux dolomitization, as inferred by their nearly syn-depositional U-Pb ages and elevated δ18O caused by seawater evaporation. The subsequent moderate burial dolomite cement (D3) was most plausibly the product of burial compaction as indicated by its lighter δ18O and slightly younger U-Pb ages compared with D1 and D2. Whereas deep burial dolomite cements (D4 and D5) yield markedly depleted δ18O, elevated 87Sr/86Sr, along with much younger U-Pb ages and higher precipitation temperatures, suggesting that they were likely linked to hydrothermal fluids. Despite the wide occurrence of meteoric and organic acids leaching and thermochemical sulfate reduction, they may have only played a subsidiary role on these reservoirs development. Instead, superior reservoir quality is tightly linked to tectonics as inferred by higher reservoir quality closely related to the well-developed fractures and faults filled with abundant hydrothermal minerals. Notably, good reservoirs in both formations are mainly attributed to high permeability caused by tectonics. Hence, this new contribution emphasizes the crucial role of tectonics on spatially explicit reservoir prediction of deep to ultra-deep (up to > 8000 m) carbonates in the Sichuan Basin, as well as other sedimentary basin analogues in China.

Evolutionary mechanism of the precipitation behavior and organization of iron-containing intermetallic phase during solidification of recycled high-Fe Al-Zn-Mg-Cu melts

The remelting of aluminum scraps can result in the accumulation of impurities, with iron being the most prevalent among them. The presence of such impurities can cause downgrading and hindered utilization of the material. Despite this, the evolution mechanism of the Iron-containing Intermetallic Phase (IIP) in recycled high-Fe and low-Si aluminum melt has received limited attention and requires further investigation. This study investigates the evolution mechanism underlying the precipitation behavior and organization of the IIP during the solidification process of recycled high-Fe Al-Zn-Mg-Cu melts, utilizing a combination of simulation and experiment. Our findings indicate that the precipitation behavior of the high-temperature precipitation phase (HPP) in the melt is influenced by the Mn and Si, which subsequently determines the organization of the IIP. Specifically, the predominant forms of IIP in the recycled high-Fe Al-Zn-Mg-Cu alloys are lamellar and hollow rod-like phases with anisotropic, as well as skeletal phases with isotropic organization. Moreover, the synergistic addition of Mn and Si can increase the precipitation temperature (PT) and precipitation temperature interval (PTI) of the Al15(Fe,Mn)4Si2 phase in the melt, leading to the transformation of the IIP into a skeletal organization that can be easily removed and has less impact on the material properties. These findings provide insights into alloy design strategies aimed at minimizing the impact of iron accumulation on the cycle life of aluminum scraps and the performance of recycled aluminum.

High-temperature precipitation behavior of W-containing 444-type ferritic stainless steel in a simulated cyclic annealing process

An important aspect of energy conservation and emission reduction in automotive industry is to improve the combustion efficiency of gasoline. The full combustion of gasoline will inevitably cause an increase in exhaust temperature. The coarsening and dissolution behavior of precipitates in steel will lead to a decrease in its high-temperature mechanical properties when the engine is used for a long time in such an alternating heating and cooling environment. In order to obtain ferritic stainless steel with good high-temperature resistance, this paper is based on 444 ferritic stainless steel and attempts to partially replace Mo element with W element to obtain Laves phase containing W, Mo, and Nb with more stable high-temperature performance. A simulated cyclic high-temperature annealing process up to 1050 °C was designed to investigate the precipitation behavior in this modified ferritic stainless steel. The results show that using W to replace Mo in 444 ferritic stainless steel can refine the grains of ferritic stainless steel. It can not only provide better solid solution strengthening at elevated temperature, but also stabilize the Laves phase and provide precipitation strengthening. The reason is that the W elements can change the composition of the Laves phase in ferritic stainless steels and precipitate Fe2(Nb, W) with high thermal stability to provide stable precipitation strengthening during long-term alternating annealing. The W-rich Laves phase is prone to precipitation at grain boundaries, effectively pinning grain boundaries and preventing microcracks from propagating along grain boundaries during service, thereby improving the service life of the steel.

The extent of windfarm infrastructures on recognised European blanket bogs

Peatland environments are the Earth’s largest terrestrial carbon store and have the potential to act as carbon sinks. However, the development of windfarms on peatlands is affecting their morphology, hydrology, ground-level climate conditions, carbon functions and vegetation, and long-term consequences still need to be assessed. Blanket bogs are a rare type of ombrotrophic peatland that are typical of oceanic areas with high precipitation and low temperatures. Their distribution has been mapped across Europe, where they are mainly located on hill summits where wind energy potential is higher, making them attractive sites for windfarm developments. The promotion of renewable energy is currently a priority given the environmental and economic drive to increase low-carbon energy production. Establishing windfarms on peatland in pursuit of greener energy, therefore, risks compromising and undermining the green-energy transition. Despite this, the extent of windfarm infrastructures on blanket bogs have not yet been reported at the European scale. This research reports the extent of windfarm infrastructures on recognised blanket bogs, with a geographical focus on Europe, where blanket bogs have been mapped systematically. Under the EU Habitats Directive (92/43/EEC), there are 36 European regions NUTS level 2 with recognised blanket bogs. Of these, 12 have windfarm developments, including 644 wind turbines, 253.4 km of vehicular access tracks and an affected area of 207.6 ha, mainly in Ireland and Scotland where the extent of blanket bogs is also higher. However, despite Spain having under 0.2% of Europe’s recognised blanket bogs area, this was the most affected country. In Scotland, a comparison of the recognised blanket bogs under the Habitats Directive (92/43/EEC) with blanket bogs recorded in national inventories indicates that the extent of windfarm developments was higher, with 1,063 wind turbines and 634.5 km of vehicular access tracks. Our results highlight the extent of windfarm developments on blanket bog habitat, both in areas where peatlands are broadly distributed across the landscape, and also in areas where this recognised habitat is particularly rare. There is a pressing need to assess the long-term impacts of windfarms on peatlands to ensure that efforts to meet energy targets result only in carbon sequestration, and do not jeopardise ecosystem services. Blanket bogs represent a particularly vulnerable habitat, the study of which should be prioritised updating national and international inventories to protect and restore this habitat.

Derivation of phase field model for the second nearest interatomic potential of D022 structure and sedimentation process in N0.75AlxV0.25−x alloy

This paper obtains a new phase field method that can simultaneously calculate the interaction potential between the first and second neighbor atoms of the D022 structure Ni3V phase in the Ni0.75AlxV0.25−x alloy, and analyzes the interaction potential between the two neighbor atoms of the D022 structure with the change trend of temperature and concentration. The feasibility of using the phase field method to invert the interaction potential between two neighboring atoms of the D022 structure in the Ni0.75AlxV0.25−x alloy laws and the precipitation of D022 and the types of interfaces formed by D022 and L12 during the aging process to be used in the microscopic phase field equation is studied. The results show that with the increase/decrease of the temperature or the concentration of solute atoms, the first neighbor interaction potential between the first neighbor atoms of the D022 structure increases/decreases and the neighbor interaction potential between the second neighbor atoms of the D022 structure decreases/increases; Ni0.75AlxV0.25−x alloys form two ordered phase interfaces between L12 and D022 phases during high temperature precipitation; at the same temperature and the concentration, the calculated interatomic potential is similar to the interatomic potential obtained by other methods. The calculated interatomic potential is substituted into the phase field model, and the simulated alloy precipitation results are consistent with the experimental results.

Seasonal differences in nitrogen deposition affect nitrogen content in mosses: Implications for biomonitoring

Nitrogen (N) pollution is a global threat to biodiversity. Moss biomonitoring is used to assess the levels of nitrogen pollution due to the high correlation between the nitrogen content in moss tissues (%N) and atmospheric N deposition. However, this relationship is controversial as %N can be affected by seasonal changes in climate and N depositions. This study aimed to investigate the effects of seasonal climate and N deposition patterns on %N in moss (Calohypnum plumiforme). Ten study sites in Japan were classified as “summer” and “winter” N deposition areas based on the season which received the highest N deposition (summer and winter, respectively). The %N showed a stronger positive correlation with N concentration than N amount in the wet deposition in both areas. These correlations exhibited seasonal differences and were not significant during the growing season with high precipitation and warm temperatures, or during the snowy season. Regression analyses revealed that winter and autumn N concentrations were the most important factors for determining the %N in the summer and winter N deposition areas, respectively. This may be due to: (1) the large contributions from high N concentrations in the initial rain on N uptake by mosses, (2) limitations in N uptake by mosses per rainfall event, (3) dilution of %N during growing seasons, and (4) low retention efficiency for snow N in mosses. The influence of the first and second factors on %N was noticeable in the summer group with large differences in seasonal precipitation, whereas the influence of the fourth factor was strongly reflected in the winter group with frequent snowfall. Based on these results, the %N can be determined not by the total N amount but by the N concentration in the wet deposition during the non-growing and snow-free seasons.

Causes of variation in the concentration and distribution of H2S in carbonate reservoirs of the Feixianguan Formation, Lower Triassic in the eastern Sichuan Basin

Hydrogen sulfide (H2S) has been encountered in many oil and gas fields worldwide, causing potentially various health and safety issues; thus, it is crucial to assess its concentration before drilling. Natural gas from the Feixianguan carbonates in the Jiannan gas field is predominantly composed of methane with various H2S concentrations varying from very minor to 3.71%. However, the H2S concentrations display obvious difference, ranging from 0.18% to 0.81% in the southern zone and 0.21–3.71% in the northern zone, with high concentrations (>1%) occurring selectively in dolomitized reservoirs in the northern zone. Based on petrographic and geochemical data and reactive transport numerical modeling, the H2S origin and sulfate sources were analyzed for understanding factors controlling the H2S concentration and distribution.In the northern zone containing high H2S concentrations, there is a common mineral assemblage of pyrobitumens, burial calcite cements, pyrite, and hemispherical elemental sulfur in dolomite reservoirs. Burial calcite cements, often coated by pyrobitumens, have higher precipitation temperatures (>106 °C), and lighter δ13C ratios than host dolostones, suggesting the incorporation of organic carbon into the precipitation of these high-temperature burial calcites supplied by thermochemical sulfate reduction (TSR). Numerical modeling indicates the SO42− concentrations of pore waters would increase significantly in dolomitized domains during seawater-involved dolomitization, consisting with the fact of the higher SO42− concentrations of pore waters in the northern zone. The dolomitizing fluids delivered sulfates into reservoirs which were inevitably reduced by hydrocarbons, once the reaction temperature was reached. Comparatively, in the southern zone where carbonates were not subjected to intensive dolomitization and the SO42− concentrations of pore waters were low, the H2S originated only from the thermal decomposition of oil and organic matter (<1%). This study implies that hydrocarbon exploration in dolomitized reservoirs should be given greater caution because of the more favorable conditions for H2S generation.

Highly efficient Fe separation induced by Fe-containing particle agglomeration in Al-7Si-0.3Mg alloy melt

In this paper, the melt turbulence process was introduced to result in Fe-containing particle agglomeration and achieve highly efficient Fe separation in Al-Si alloy melt. Microstructure analysis, 3D-morphology extraction, X-ray microscopy (μCT) analysis were conducted to discuss the phenomenon and mechanism of Fe-containing particle agglomeration. The experimental results indicate that the Fe-containing particle is suitable for separation due to the high precipitation temperature and particulate morphology. Then, the intervention of rotor stirring greatly promotes collision, adhesion and agglomeration of Fe-containing particles during sedimentation separation. The Fe-containing particle agglomeration showed a maximum diameter of 1650 μm and a 67.67% reduction of Fe were obtained after rotor stirring. When the sedimentation separation is intervened by rotor stirring and argon blowing, the agglomeration effect of Fe-containing particles further promotes. The Fe-containing particle agglomeration shows the maximum size of 1800 μm and a high Fe separation efficiency of 74.46% were obtained. The simultaneously exerting of rotor stirring and argon blowing promotes the formation of agglomeration attached by small Fe-containing particles, which also contributes to higher Fe separation efficiency. These results provided a new sight to achieve high Fe separation efficiency in Al-Si alloy melt by industrially viable methods.

Effects of the Main Ecological Restoration Projects on Grassland Carbon Sequestration in Ningxia on the Loess Plateau

The temperate steppe experienced degradation and desertification as a result of long-term heavy grazing and excessive reclamation. Some major ecological projects, such as the Grain for Green Program (GGP) and Grazing Exclosure (GE), have been implemented to promote ecological restoration in grassland ecosystems. With the goal of carbon neutrality, the effects of the GGP and GE on grassland carbon sequestration need to be further explored. Based on soil data from the second soil survey in the 1980s, a field survey in 2021, and the land-use/land-cover datasets of 2000–2018, we characterized the changes in soil C stock following grazing exclosure, analyzed the effect of GGP on land-use changes and soil C accumulation, and then estimated the overall grassland carbon sequestration in Ningxia on the Loess Plateau of China. From 2000 to 2018, GE increased the grassland SOCD from 49.60 Mg ha−1 to 90.71 Mg ha−1, and the C stock increased by 65.55 T g. Under the influence of the GGP, 347.62 km2 of cultivated land was converted into grasslands, increasing the grassland soil carbon sequestration by 1.31 T g. Subsequently, the grassland organic carbon storage increased by 66.86 T g, which accounted for approximately 4.26% of the grassland organic carbon storage in the Loess Plateau of China. In the southern Loess hilly area, which experienced high precipitation and low temperatures, grasslands increased by 95.55 km2; the average organic carbon density increased 46.95 Mg ha−1 due to a rate of increase of 2.61 Mg ha−1 yr−1; and the corresponding values for those in the middle arid zone were 36.25 Mg ha−1 and 2.01 Mg ha−1 yr−1, with grasslands decreasing by 147.41 km2. The follow-up policies of the GGP and GE should be implemented and improved according to local conditions to improve the carbon sink and ecological services in grassland ecosystems.

High-Temperature Precipitation of Impurities in Metals

High-Temperature Precipitation of Impurities in Metals

High-temperature filtration demonstration applying Fe-Al intermetallic membrane for a 410 t/h scale coal-fired power plants

High-temperature filtration in coal units is a promising approach for the clean and efficient utilization of coal power. In this paper, a high-temperature precipitator was applied in a 5000 Nm3/h pilot scale platform and especially a full scale 410 t/h pulverized coal boiler, where the precipitator was installed in front of the denitrification unit. The 410 t/h pulverized coal boiler was tested before and after the installation of high-temperature precipitator. The results showed that the particulate matter concentrations at the outlet of the high-temperature precipitator are both less than 8 mg/m3 at nominal 70% and 90% loads. Meanwhile, the outlet concentration increases with the boiler load. The pressure drop for a high-temperature precipitator applying Fe-Al intermetallic membrane is only 500 ± 50 Pa under 90% loads, which is much less than that of conventional fabric filter. Furthermore, gaseous ammonia injection and ammonia escape in the SCR reactor are both decreased under the same denitrification efficiency compared with the typical flue gas pollution post-treatment technologies. The air preheater blockage is potentially the biggest issue for coal-fired power plant and has attracted extensive attention. As expected, the application of the high-temperature precipitator greatly alleviated the negative effects of high fly ash concentrations and reduced the pressure drop for the air preheater during the test. The pressure drops benefit brought by the high-temperature precipitator for the module including high-temperature precipitator, SCR unit, air preheater approaches 1500 ± 50 Pa. Taking a 1000 MWe coal-fired unit and a typical bituminous coal for example, a 1000 MWe coal-fired unit applying the high-temperature precipitator is expected to achieve 30% relevant energy consumption benefit. Furthermore, a total of 4.48 million tons CO2 emission reduction per year could be achievable if 70% of the Chinese national thermal power market employed them by 2060.

Photosynthetic trends in India derived from remote sensing measurements during 2000–2019: vegetation dynamics and key climate drivers

Significant changes in the photosynthesis of terrestrial vegetation are observed in recent decades due to climate variability, land use and land cover changes, frequent disasters and anthropogenic forcing, but this situation in the Indian context remains largely unexplored. Here, therefore, we estimate the long–term changes in photosynthesis and its key climate drivers in India. The gross photosynthetic activity peaks (FPAR mean = 0.57) in post–monsoon (September, October and November) due to high soil moisture (87.26 kg/m2), good precipitation (5.2 mm/day) and optimum temperature (21.46 °C) conditions, whereas it is smallest (FPAR mean = 0.4) in summer (March, April and May) due to very high temperature (27.37 °C) and lower soil moisture (55.45 kg/m2). The trend in FPAR over 2000–2019 reveals enhanced photosynthetic activity in India. In the northwest, both soil moisture and temperature have a positive influence on greening (i.e. moisture induced greening). Conversely, the unfavourable soil moisture and temperature conditions dominate in the peninsular region to trigger browning there (i.e. warming induced moisture stress). Our analyses suggest that the photosynthetic trend is primarily controlled by trend in the soil moisture (44.31%) and air temperature (32.54%). The warming induced moisture stress can be a serious threat in the future to drive browning in more areas. Extreme events such as droughts, landslides and fires are expected to increase in the hilly regions such as the northeast due to browning. Furthermore, as food production and forest resources influence the economy of a country like India, management and conservation of greenery are inevitable for a sustainable ecosystem.