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Soil aggregates play pivotal roles in soil organic carbon (SOC) preservation and climate change. Biochar has been widely applied in agricultural ecosystems to improve soil physicochemical properties. However, the underlying mechanisms of SOC sequestration by soil aggregation with biochar addition are not well understood at a large scale. Here, we conducted a meta-analysis of 2335 pairwise data from 45 studies to explore how soil aggregation sequestrated SOC after biochar addition in agricultural ecosystems of China. Biochar addition markedly enhanced the proportions of macro-aggregates and aggregate stability, and the production of organic binding agents positively facilitated the formation of macro-aggregates and aggregate stability. Soil aggregate-associated organic carbon (OC) indicated a significantly increasement by biochar addition, which was attributed to direct and indirect inputs of OC from biochar and organic residues, respectively. Biochar stimulated SOC sequestration dominantly contributed by macro-aggregates, and it could be interpreted by a greater improvement in proportions and OC protection of macro-aggregates. Furthermore, the SOC sequestration of soil aggregation with biochar addition was regulated by climate conditions (mean annual temperature and precipitation), biochar attributes (biochar C/N ratio and pH), experimental practices (biochar addition level and duration), and agronomic managements (land type, cropping intensity, fertilization condition, and crop type). Collectively, our synthetic analysis emphasized that biochar promoted the SOC sequestration by improving soil aggregation in agricultural ecosystems of China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The objective of this paper is to examine the representativeness of charcoal taxa at archeological sites in northern China. We carried out standardized laboratory compression tests on 168 samples representing 21 taxa charred at four different temperatures to characterize the mechanical properties of common taxa in temperate China. The results indicate that significant fragmentation differences occur between taxa. Ring-porous/semi-ring-porous taxa with a moderate density (>0.55 g/cm3) are overrepresented, while those with a very low to low density (<0.55 g/cm3) are moderately represented. Diffuse-porous taxa with slightly dense uniseriate rays, rare multiseriate rays and distinct helical thickenings are underrepresented, and those with slightly dense multiseriate rays are overrepresented, while those with rare to moderate multiseriate rays and helical thickening absence are moderately represented. Gymnosperm trees are generally well represented. Among the ubiquitous taxa at the archeological sites across northern China, Quercus and Ulmus may be overrepresented, and Pinus, Salix, Populus, and Acer may be underrepresented, while Betula may be moderately represented. [ABSTRACT FROM AUTHOR]

Vegetation concrete is one of the most widely used substrates for slope ecological protection in China. However, there are still some imperfections that are disadvantageous for plant growth, such as high density, low porosity, insufficient nutrient retention ability and so on. In this paper, the effect of wood activated carbon and mineral activated carbon on the physicochemical properties of vegetation concrete is studied. The experimental results show that the activated carbon proportion in vegetation concrete is positively related to the porosity, permeability coefficient, water holding capacity, and nutrient content and retention ability, while it is negatively related to the dry density, water retention ability, cohesive force and internal friction angle. However, it should be noticed that when the proportion exceeds 2%, the average height, aboveground biomass and underground biomass of Cynodon dactylon decrease with increasing proportion of activated carbon. The effect of wood activated carbon is generally more remarkable than that of mineral activated carbon. In addition, according to the research results, the effect of activated carbon on vegetation concrete can last for at least half a year, although it does slowly deteriorate with increasing time. By comprehensive consideration of the current industry standard, previous research results and economical reasoning, the recommended type of activated carbon is wood, with a corresponding suitable proportion ranging between 1 and 2%.

Background and objective Xuanwei and Fuyuan are rural counties, located in the late Permian coal poly area of eastern Yunnan and western Guizhou, where lung cancer mortality rates are among the highest in the China, with similarity for both men and women, younger age at diagnosis and death, and higher in rural areas than in urban areas. In this paper, long-term follow-up of lung cancer cases in local peasants was conducted to observe their survival prognosis and its influencing factors. Methods Data of patients diagnosed with lung cancer from January 2005 to June 2011, who had lived in Xuanwei and Fuyuan counties for many years, were collected from 20 hospitals at the local provincial, municipal and county levels. To estimate survival outcomes, individuals were followed up until the end of 2021. The 5-year, 10-year and 15-year survival rates were estimated using the Kaplan-Meier method. Survival differences were examined with Kaplan-Meier curves and Cox proportional hazards models. Results A total of 3,017 cases were effectively followed up (2,537 peasants and 480 non-peasants). The median age at diagnosis was 57 years, and the median follow-up time was 122 months. During the follow-up period, 2,493 cases (82.6%) died. The distribution of cases by clinical stage was as follows: stage I (3.7%), stage II (6.7%), stage III (15.8%), stage IV (21.1%) and unknown stage (52.7%). Treatment at the provincial, municipal and county-level hospitals accounted for 32.5%, 22.2% and 45.3%, respectively, and surgical treatment was performed in 23.3% of cases. The median survival time was 15.4 months (95%CI: 13.9-16.1), and the 5-year, 10-year and 15-year overall survival rates were 19.5% (95%CI: 18.0%-21.1%), 7.7% (95%CI: 6.5%-8.8%) and 2.0% (95%CI: 0.8%-3.9%), respectively. Peasants with lung cancer had a lower median age at diagnosis, higher proportion residing in remote rural areas, and higher use of bituminous coal as a household fuel. They also have a lower proportion of early-stage cases, treatment at provincial or municipal hospitals, and surgical treatment, leading to poorer survival outcomes (HR=1.57). Even when considering factors such as gender, age, residential location, clinical stage at diagnosis, histological type, hospital level of service, and surgical intervention, peasants still exhibit a survival disadvantage. Multivariable Cox model analysis comparing peasants and non-peasants reveals that surgical intervention, tumor-node-metastasis (TNM) stage, and hospital level of service are common factors influencing survival prognosis, while the use of bituminous coal as a household fuel, hospital level of service and adenocarcinoma (compared to squamous cell carcinoma) are independent prognostic factors for lung cancer survival among peasants. Conclusion The lower lung cancer survival rate among peasants is associated with their lower socioeconomic status, lower proportion of early-stage diagnoses, lower proportion of surgical interventions, and treatment at provincial-level hospitals. Furthermore, the impact of other factors such as high-risk exposure to bituminous coal pollution on survival prognosis requires further investigation. [ABSTRACT FROM AUTHOR]

Aim The aims of this paper are to reconstruct the vegetation and fire history over the past 2000 years in a well-preserved rain-forest area, to understand interactions between climate, fire, and vegetation, and to predict how rain forest responds to global warming and increased intensity of human activity. Location Xishuangbanna, south-west China, 21–22° N, 101–102° E. Methods Phytolith (plant opal silica bodies) morphotypes, assemblages, and indices were used to reconstruct palaeovegetation and palaeoclimate changes in detail. Micro-charcoal particles found in phytolith slides, together with burnt phytoliths and highly weathered bulliform cells, were employed to reconstruct a record of past fire occurrence. A survey of field sediments, lithology, and 14C dating were also employed. Results Phytoliths were divided into 11 groups and classified into 33 well-described morphotypes according to their shape under light microscopy and their presumed anatomical origins and ecological significance. The phytolith assemblages were divided into six significant zones that reveal a complete history of vegetation changes corresponding to climate variation and fire occurrence. Phytolith assemblages and indices show that the palaeoclimate in the study area is characterized by the alternation of warm–wet and cool–dry conditions. Phytolith and charcoal records reveal that 12 fire episodes occurred. Comparison of burnt phytoliths with an aridity index (Iph) shows that fire episodes have a strong relationship with drought events. Main conclusions Our results indicate that fire occurrence in the tropical rain forest of Xishuangbanna is predominantly under the control of natural climate variability (drought events). Nearly every fire episode is coupled with a climatic event and has triggered vegetation composition changes marked by a pronounced expansion of grasses. This indicates that drought interacts with fire to exert a strong influence on the ecological dynamics of the rain forest. However, the impact of human activity in recent centuries is also significant. Our results are important for understanding the interactions between climate, fire, and vegetation, and for predicting how rain forest responds to global warming and increased human activity. [ABSTRACT FROM AUTHOR]

Shallow burial, very close coal seam groups, and spontaneous combustion are typical characteristics of most coal seams in the Shendong mining area, China. With the continuous extension of the production level of various mines, some mining areas have gradually shown complex production conditions including multiple types of fire forms such as those in coal fields, small kilns, and multilayer mined-out and hidden high-temperature areas, resulting in fire control difficultly and posing threats to safety. With the aim of limiting the above problems, in this work, the liquid carbon dioxide fire prevention technology is focused on. Phase change and migration law of CO2 in the goaf are studied. Through the study on the influence of the use of liquid CO2 on the cooling law of high-temperature coal and on its spontaneous combustion characteristics and through thermal analysis experiments, it was observed that the porosity of loose coal has a significant impact on the cooling effect of carbon dioxide. Moreover, it was emphasized that the higher the CO2 concentration, the higher the rise in temperature of coal oxidation, and the increase of CO2 concentration was able to affect apparent activation of coal oxidation, leading to a theoretical basis to explain the effect of CO2 in inhibiting coal spontaneous combustion. The utilization of Fluent numerical modeling allowed us to simulate the diffusion radius of liquid CO2 injected into the goaf, to study the effective inerting radius of liquid CO2 on the left coal in the goaf. After comprehensive analysis of experiments and numerical simulations, appropriate equipment and process flow are selected and designed. Taking the Huojitujing well of Daliuta Coal Mine in Shendong mining area as the industrial test site, an intelligent pressure-holding transportation of liquid CO2 in the 1000 m transportation pipeline was developed. The surface liquid CO2 infusion capacity was 20 t/h, and the pressure-holding interval at the end of the transportation pipeline was determined to be 1.0–2.3 MPa. The maximum diffusion radius of the mined-out area is 300 m under the effect of positive air flow and self-expansion and diffusion of CO2 gas in the roadway. Under the influence of reverse wind flow and self-expansion and diffusion, the diffusion radius of the goaf is 150 m, and the maximum storage time of gaseous CO2 in the goaf is 27 h. Liquid CO2 was injected into the area with relevant presence of CO, an indicator of possible fires. Practice has proved that, after 65 hours and two perfusion processes, the CO concentration dropped from 790 ppm to 41 ppm, which indicates that liquid CO2 has a significant effect on fire prevention. [ABSTRACT FROM AUTHOR]

Iron and steel sector is the largest industrial energy consumer and emission source of greenhouse gas and air pollutants in China. Therefore, it is imperative to conduct a quantitative assessment for energy conservation potential and environmental benefits of China's iron and steel industry. Energy efficiency improvement, EAF promotion and charcoal substitution are efficient measures to achieve cleaner and sustainable development. In this paper, five scenarios are designed for comprehensively analyzing the multiple factors influencing the potential for energy conservation and emission reduction. Furthermore, emissions reduction benefits of air pollutants are combined with Conservation Supply Curves to accurately evaluate the cost of the technology. A comprehensive emission inventory of air pollutants is established. The results show that under the synergistic effects of charcoal substitution, EAF improvement and energy efficiency improvement, significant environmental benefits have been achieved. Energy intensity was reduced obviously from 16.59 GJ/t-steel in 2017 to 14.46 GJ/t-steel in 2030 in integrated scenario, while the emission intensity of GHG, SO 2 , NO x , PM 2.5 , PM 10 , CO and VOCs in 2030 is decreased by 21.53%, 14.59%, 17.07%, 0.16%, 0.22%, 16.5% and 20.67% compared with business-as-usual scenario. In addition, combining Conservation Supply Curves with emissions reduction benefits can significantly reduce the cost of the technology, which has a great significance to the popularization and application of technologies. Sensitivity analysis in terms of discount rate and energy price is conducted. This study could help policy makers to cast light on the status quo and prompt more effective policies for China's iron and steel industry. Image 1 • Energy conservation and emission reduction supply curve model was established. • Mitigation potential of three greenhouse gases and six air pollutants were studied. • The effect of charcoal substitution in the iron-making process was evaluated. • Five scenarios were set to assess the energy saving and mitigation potential. [ABSTRACT FROM AUTHOR]

The site of Shuidonggou Locality 2 offers important evidence for the Late Paleolithic sequence of north China. The site not only contains one of the earliest instances of ornamental freshwater shell and ostrich eggshell beads in the region, but also stone artifacts with features arguably resembling the Initial Upper Paleolithic (IUP) blade technology found farther north. The appearance of these innovative archaeological forms have been attributed to the arrival of hominin populations, possibly modern humans, into the region during Marine Isotope Stage 3. Yet, the chronology of the site remains debated due to ambiguities in the existing dates. In this study, we conduct a systematical radiocarbon analysis of charcoal and ostrich eggshell samples obtained throughout the site sequence. Both acid-base-acid and the more stringent acid-base-oxidation pretreatment methods were applied to the charcoal samples. The resulting ages follow an age-depth relationship that is consistent with the stratigraphic profile. In line with previous stratigraphic assessments, Bayesian age modeling suggests that site formation history can be split into two phases: an early phase 43–35 cal kBP associated with a lacustrine depositional environment, and a later phase 35–28 cal kBP associated with rapid terrestrial silt accumulation. The chronology of the archaeological layers containing IUP-like artifacts are placed at 43–39 cal kBP and 35–34 cal kBP respectively. This finding supports the interpretation that an IUP-like blade technology appeared in the SDG region by at least ~41 ka. [ABSTRACT FROM AUTHOR]

Background: Charcoal burning in a sealed room has recently emerged as the second most common suicide means in Hong Kong, causing approximately 200 deaths each year. As charcoal burning suicide victims have a unique sociodemographic profile (i.e., predominantly economically active men), they may commit suicide at specific times. However, little is known about the temporal patterns of charcoal burning suicides. Methods: Suicide data from 2001 to 2008 on victims of usual working age (20-59) were obtained from the registered death files of the Census and Statistics Department of Hong Kong. A total of 1649 cases of charcoal burning suicide were analyzed using a two-step procedure, which first examined the temporal asymmetries in the incidence of suicide, and second investigated whether these asymmetries were influenced by sex and/or economic activity status. Poisson regression analyses were employed to model the monthly and daily patterns of suicide by economic activity status and sex. Results: Our findings revealed pronounced monthly and daily temporal variations in the pattern of charcoal burning suicides in Hong Kong. Consistent with previous findings on overall suicide deaths, there was an overall spring peak in April, and Monday was the common high risk day for all groups. Although sex determined the pattern of variation in charcoal burning suicides, the magnitude of the variation was influenced by the economic activity status of the victims. Conclusion: The traditional classification of suicide methods as either violent or nonviolent tends to elide the temporal variations of specific methods. The interaction between sex and economic activity status observed in the present study indicates that sex should be taken into consideration when investigating the influence of economic activity status on temporal variations of suicide. This finding also suggests that suicide prevention efforts should be both time- and subgroup-specific. [ABSTRACT FROM AUTHOR]