{"title":"Review of Control Techniques for Interleaved Buck Converters: Control Strategies, Efficiency Optimization and Phase Shedding*","authors":"Xiuyun Zhang;Guidong Zhang;Samson S. Yu","doi":"10.23919/CJEE.2025.000108","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000108","url":null,"abstract":"High-performance microprocessors have rapidly evolved and become ubiquitous in modern society. However, their power supply has become a significant factor limiting their overall performance. A power delivery module, known as a voltage regulator module (VRM), is required to provide high voltage, low current, and a fast transient response to meet microprocessor demands. An interleaved parallel-buck converter is suitable for VRM applications. Selecting an appropriate control strategy for the interleaved converter can help achieve high precision and fast response, thereby optimizing performance. First, the operating principles of interleaved parallel converters are analyzed. The relationship between the number of phases and conversion efficiency is also examined. Subsequently, commonly employed control techniques for interleaved converters are reviewed, discussing their respective advantages and limitations, along with an analysis of their suitability for phase-shedding strategies. A phase-shedding technique for interleaved converters is then introduced. Finally, the shortcomings of current control approaches for interleaved buck converters are outlined, and potential future research directions are suggested. These insights aim to enhance control performance and advance practical engineering applications.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"40-58"},"PeriodicalIF":0.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10923626","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhenling Fu , Hangbiao Jin , Ruyue Guo , Weili Mao
{"title":"Human urinary occurrence of dithiocarbamate vulcanization accelerators and their exposure estimation","authors":"Zhenling Fu , Hangbiao Jin , Ruyue Guo , Weili Mao","doi":"10.1016/j.emcon.2025.100499","DOIUrl":"10.1016/j.emcon.2025.100499","url":null,"abstract":"<div><div>Dithiocarbamate vulcanization accelerators (DVAs) are widely used in rubber manufacturing, yet their potential human exposure and associated health risks remain poorly understood. Previous studies have identified DVAs in various environmental matrices, such as dust and sediments, but their occurrence in human biological samples has not been investigated. This study aims to fill this critical research gap by conducting the first comprehensive biomonitoring assessment of DVAs in human urine, providing direct evidence of human exposure. A total of 263 urine samples were collected from Chinese adults and analyzed for eight DVAs. Seven out of eight target compounds were detected, with detection frequencies ranging from 14 % to 94 %. Zinc diethyldithiocarbamate (ZDEC) was the predominant compound, with a mean concentration of 1.6 ng/mL (range: <LOD–12 ng/mL). Notably, males exhibited significantly higher urinary levels of ZDEC (1.7 ± 0.28 ng/mL vs. 1.3 ± 0.33 ng/mL; <em>p</em> = 0.021) and zinc dibutyldithiocarbamate (ZDBC; 0.78 ± 0.18 ng/mL vs. 0.50 ± 0.10 ng/mL; <em>p</em> = 0.017) compared to females, while urinary concentrations of ZDEC and zinc dibenzyldithiocarbamate (ZBEC) were inversely correlated with age. Daily exposure (DE) estimation revealed that ZDEC had the highest mean DE value at 48 ng/kg bw/day, followed by ZEPC (29 ng/kg bw/day) and ZDBC (21 ng/kg bw/day). These findings provide essential insights into human exposure patterns to DVAs, offering a scientific basis for future risk assessment and regulatory considerations. Given the widespread detection of these compounds and their potential toxicity, further research is warranted to elucidate their health implications and major exposure pathways.</div></div>","PeriodicalId":11539,"journal":{"name":"Emerging Contaminants","volume":"11 2","pages":"Article 100499"},"PeriodicalIF":5.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
环境科学Pub Date : 2025-03-08DOI: 10.13227/j.hjkx.202403219
Yun-Feng Li, Ji-Lin Tang, Yuan-Yuan Ji, Ya-Fei Wang, Hong Li, Rui Gao
{"title":"[Comparative Analysis of Ambient Ozone and Its Background Concentration in Beijing in Recent Years].","authors":"Yun-Feng Li, Ji-Lin Tang, Yuan-Yuan Ji, Ya-Fei Wang, Hong Li, Rui Gao","doi":"10.13227/j.hjkx.202403219","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403219","url":null,"abstract":"<p><p>To understand the trends of O<sub>3</sub> pollution changes and the contribution of regional background in Beijing in recent years, this study investigated the temporal variations of O<sub>3</sub> mixing ratios and the exceedance of O<sub>3</sub> pollution at different types of sites, such as urban, suburban, clean, regional, and transportation sites, based on the online monitoring data from 34 stations in Beijing from 2018 to 2022. The regional background estimation method proposed by the Texas Commission on Environmental Quality (TCEQ) was applied to calculate the contributions of regional background and local generation to O<sub>3</sub>. The results showed that the annual average value of O<sub>3</sub> mixing ratios in Beijing was the highest in 2019, the lowest in 2021, and rebounded in 2022, from 2018 to 2022. Except for transportation sites, O<sub>3</sub> mixing ratios in Beijing and all other types of sites exhibited decreasing trends. The highest monthly average value of O<sub>3</sub> occurred in June and the monthly average values of clean sites were often higher than those of other sites. The proportions of O<sub>3</sub> exceedance days and heavily polluted days varied over the last five years and days with high O<sub>3</sub> pollution more often occurred at the clean site. The O<sub>3</sub> exceedance days were mostly dominated by light pollution and the average O<sub>3</sub> mixing ratios on heavily polluted days in 2020-2022 were greater than those in 2019. To exclude the influence of NO on the \"titration\" effect of O<sub>3</sub>, the TCEQ method was estimated by using the total oxidant O<i><sub>x</sub></i> (O<i><sub>x</sub></i>=O<sub>3</sub>+NO<sub>2</sub>) instead of O<sub>3</sub>. The results showed that both the regional background and the local generation in Beijing showed decreasing trends and the contribution of the regional background was significantly higher than that of the local generation. However, the contribution of the regional background decreased in the summer due to the enhancement of the photochemical activities. In general, although the O<sub>3</sub> mixing ratios in Beijing had been decreasing from 2018 to 2022, no such trend was observed in the O<sub>3</sub> mixing ratios on heavily polluted days. To achieve the goal of basically eliminating heavily polluted days in the 14th Five-Year Plan and to effectively control O<sub>3</sub> pollution, it is recommended that Beijing should further optimize the joint prevention and control of atmosphere pollution in Beijing-Tianjin-Hebei and neighboring regions to reduce the contribution of regional background to O<sub>3</sub> pollution while strengthening the control of local O<sub>3</sub> precursor emissions.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1275-1284"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"[Analysis of PM<sub>2.5</sub> and O<sub>3</sub> Pollution Causes in Hangzhou Based on High-resolution Enhanced Observation During the Asian Games].","authors":"Ren-Chang Yan, Yong Lai, Tian Zhang, Jia-Jia Jin, Xu Lin, Yun-Yun Wang, Qi-Fan Shuai, Luo-Lan Fei, Jian-Dong Shen, Xu-Hong Ye, Shu-Hui Zhu","doi":"10.13227/j.hjkx.202402091","DOIUrl":"https://doi.org/10.13227/j.hjkx.202402091","url":null,"abstract":"<p><p>Based on the high-resolution enhanced observation data of PM<sub>2.5</sub> organic molecular tracers, aldehydes and ketone OVOC components, long-chain alkane IVOC components, and key species of atmospheric oxidation during September 1 to October 27, 2023, the causes of PM<sub>2.5</sub> and O<sub>3</sub> pollution in Hangzhou were analyzed. Seven pollution processes were selected with the average daily concentration of PM<sub>2.5</sub> exceeding 35 μg·m<sup>-3</sup> or the maximum 8-hour concentration of O<sub>3</sub> exceeding 160 μg·m<sup>-3</sup>. Then, these pollution processes were divided into four types: north-northeast transmission type (T1), east-southeast transmission type (T2), north-northwest transmission type (T3), and statically stable type (T4) by airflow trajectory. The research results indicated that the T2 pollution process exhibited strong PM<sub>2.5</sub> and O<sub>3</sub> composite pollution characteristics and the photochemical oxidation reaction of active VOC components, such as long-chain alkanes and terpenes in the atmospheric environment was the major pollution cause of this type. In the process of T1 and T3 pollution, the overall reactivity of VOCs was low, resulting in relatively weak O<sub>3</sub> generation. However, the causes of PM<sub>2.5</sub> in these two types of pollution processes were different. T1 pollution was affected by low temperature and high humidity meteorological conditions and the enhanced liquid-phase oxidation process led to a significant increase in nitrate concentration. T3 pollution was significantly affected by emissions from coal combustion, biomass combustion, and other sources, with a relatively high proportion of primary components in PM<sub>2.5</sub>. The T4 pollution process was significantly affected by local primary anthropogenic emissions, thus the control of local catering source and mobile source emissions must be strengthened.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1302-1313"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
环境科学Pub Date : 2025-03-08DOI: 10.13227/j.hjkx.202403158
Gang-Li Sun, Da-Wei Niu, Nan Zhang, Ya-Qin Ji, Li-Ping Wu, Xue-Yan Zhao, Wen Yang
{"title":"[Emission Characteristics of Polycyclic Aromatic Hydrocarbons and Their Derivatives from Exhaust PM<sub>2.5</sub> of China Ⅴ and China Ⅵ Diesel Trucks Based on On-road Measurements].","authors":"Gang-Li Sun, Da-Wei Niu, Nan Zhang, Ya-Qin Ji, Li-Ping Wu, Xue-Yan Zhao, Wen Yang","doi":"10.13227/j.hjkx.202403158","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403158","url":null,"abstract":"<p><p>Exhaust emissions from diesel vehicles are one among the major sources of PM<sub>2.5</sub> and polycyclic aromatic hydrocarbons (PAHs) emitted by diesel vehicles are of concern due to their notable impact on health. To better understand the toxicity of diesel vehicle emissions, we used an on-road sampling system to collect PM<sub>2.5</sub> samples from four light-duty diesel trucks (LDDTs) and two heavy-duty diesel trucks (HDDTs) under the China Ⅴ and China Ⅵ emission standard. Further, 16 polycyclic aromatic hydrocarbons (pPAHs), 18 nitro-polycyclic aromatic hydrocarbons (NPAHs), and five oxygenated polycyclic aromatic hydrocarbons (OPAHs) were analyzed by GC-MS, and mileage-based emission factors were calculated. The results showed that a decrease in emission factors (EFs) of PM<sub>2.5</sub>-bound pPAHs, NPAHs, and OPAHs was observed with improved emission standards. The EFs of pPAHs, NPAHs, and OPAHs from LDDTs of the China Ⅵ emission standard were (217.92±109.92), (5.21±2.51), and (10.74±5.99) μg·km<sup>-1</sup>, respectively, which were reduced by 63%, 55%, and 66% compared to those with China Ⅴ. Due to incomplete combustion, higher emission factors (EFs) were observed for HDDTs than for LDDTs with the same emission standard (China Ⅴ). The EFs of PM<sub>2.5</sub>-bound pPAHs, NPAHs, and OPAHs emitted from the diesel vehicles were higher with increasing mileages, which was related to increased engine wear. Phenanthrene and fluorenone were the most abundant pPAHs and OPAHs components, while 5-nitro acenaphthene and 2-nitro fluoranthrene + 3-nitro fluoranthrene were the major NPAHs components. The benzo (a) pyrene equivalent toxicity (BaPeq) of pPAHs, NPAHs, and OPAHs of China Ⅵ vehicles was significantly reduced compared to that of China Ⅴ vehicles, which might be related to improvements in exhaust technology. The emission results showed that the diesel vehicles of the three largest-amount models in Luohe City emitted 1 965 kg pPAHs, 33 kg NPAHs, and 105 kg OPAHs, respectively. The emissions of PAHs and their derivatives were mainly from the China V heavy-duty diesel vehicles, suggesting the need to strengthen the control of this model. The results of this study will be valuable for formulating more stringent regulations and emission control technologies for PAHs and their derivatives and for the protection of human health.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1350-1361"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
环境科学Pub Date : 2025-03-08DOI: 10.13227/j.hjkx.202403190
Zhao-Hui Qin, Rong-Fei Wang, Zhi-Guo Ding
{"title":"[Impact of Environmental Pressure from Urban Development on the Level of Carbon Emissions in Urban Areas].","authors":"Zhao-Hui Qin, Rong-Fei Wang, Zhi-Guo Ding","doi":"10.13227/j.hjkx.202403190","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403190","url":null,"abstract":"<p><p>Due to the increasing and rapid economic and population growth over the past years, urban areas have become the focus of carbon-emission-reduction policies. Meanwhile, they are also continuously subjected to environmental pressure from urban development. Therefore, this study used the STIRPAT model to develop an index to capture the environmental pressure from urban development based on a panel dataset of 284 prefecture cities from 2006 to 2022 in mainland China. Subsequently, a fixed effect model and a quantile regression model were used to test the impact of the environmental pressure from urban development on the level of urban carbon emissions. The results showed a notable relationship between the environmental pressure from urban development and the level of urban carbon emissions. More specifically, for every one-unit increase in the index, the urban carbon emission level increased by 1.4%. This result was found stable after a series of robustness tests. Furthermore, quantile regression showed that before the 50th percentile, the environmental pressure from urban development had a positive impact on the level of urban carbon emissions, whereas after the 50th percentile, it had a negative impact. Finally, heterogeneity analysis indicated that, compared to in large cities, the positive impact of the environmental pressure from urban development on urban carbon emission levels was more significant in small-sized, medium-sized, and megacities. Therefore, it is recommended to continuously optimize the context for business and trading and promote the industrial structure. Carbon emission reduction targets should be differentiated based on development levels of cities. While implementing carbon emission reduction measures in urban areas, population and other conditions should be taken into account.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1473-1481"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
环境科学Pub Date : 2025-03-08DOI: 10.13227/j.hjkx.202403189
Ji-Long Ma, Kun Ma, Tie-Na Xie, Hong Li, Xiang Yue, Li Ji, Lin-Pu Han, Yong-Jie Qi, Biao Jia
{"title":"[Prediction of Spatial Distribution of Cation Exchange in Agricultural Soils Based on Machine Learning].","authors":"Ji-Long Ma, Kun Ma, Tie-Na Xie, Hong Li, Xiang Yue, Li Ji, Lin-Pu Han, Yong-Jie Qi, Biao Jia","doi":"10.13227/j.hjkx.202403189","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403189","url":null,"abstract":"<p><p>Cation exchange capacity (CEC) reflects the ability of soil to sequester exchangeable cations and is an important indicator of the fertility and environmental quality of agricultural soils. The indoor titration method for determining soil cation exchange is expensive and cumbersome. To this end, 565 soil samples from the 0-20 cm plough layer were collected from farmland in Ningxia, and the parameters of soil pH, organic carbon, and mechanical composition were determined. A field-scale soil cation exchange (CEC) estimation model was constructed using multiple linear regression and machine learning methods to obtain soil CEC values rapidly and accurately. The results showed that: ① The mean CEC value of farmland soils in Ningxia was 9.39 cmol·kg<sup>-1</sup>, with a coefficient of variation of 40.74%. This indicated a high degree of variability, with the spatial distribution of the CEC values generally showing higher values in the periphery of the Yellow River Basin (Ningxia section) and the southern mountainous areas of Ningxia and lower values in the central arid zone and the east-central region. ② The soil parameters selected for modeling the total dataset were as follows: Soil organic carbon, clay content, pH, and sand content were the important factors influencing the CEC of farmland soil in Ningxia, with correlation coefficients of 0.55, 0.72, -0.41, and -0.44, respectively. ③ The results of multiple linear regression modeling showed that dividing the total dataset according to the urban area and constructing a multiple linear-type regression model within the urban area was more conducive to the prediction of the CEC of farmland soils. ④ Compared with the multiple linear regression method, the machine learning method was more effective in the prediction of the total dataset. Further, using the multiple linear regression model as a reference, the prediction accuracy (<i>R</i><sup>2</sup>) of the back propagation neural network, convolutional neural network, back propagation neural network optimized by the particle swarm algorithm, convolutional neural network optimized by the particle swarm algorithm, back propagation neural network optimized by the grey wolf algorithm, and convolutional neural network model optimized by the grey wolf algorithm were improved by 13.59%, 30.78%, 18.91%, 35.47%, 20.94%, and 38.91%, respectively. ⑤ The validation results showed that the validation set of the convolutional neural network model optimized by the grey wolf algorithm had an <i>R</i><sup>2</sup> of 0.91, an RMSE of 1.07 cmol·kg<sup>-1</sup>, and an NRMSE of 11.77%, and the model was close to the very stable level with the best overall performance. In conclusion, the convolutional neural network model optimized by the grey wolf algorithm has high prediction accuracy and strong extrapolation ability, which is a better model for predicting soil CEC at the farmland scale. This result provides a novel idea and solution for the prediction of soil CEC in","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1737-1750"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
环境科学Pub Date : 2025-03-08DOI: 10.13227/j.hjkx.202404048
Ni-Na Yang, Jian-E Zuo, Yan-Yan Zhang, Cong Men
{"title":"[Research Progress on Plastic Aging Processes and Their Environmental Hazards].","authors":"Ni-Na Yang, Jian-E Zuo, Yan-Yan Zhang, Cong Men","doi":"10.13227/j.hjkx.202404048","DOIUrl":"https://doi.org/10.13227/j.hjkx.202404048","url":null,"abstract":"<p><p>Plastic pollution has become a global environmental issue, posing notable threats to ecosystems and human health. Plastic aging is a continuous dynamic process, during which plastics of various sizes are produced and exist, such as large plastics, microplastics, and nanoplastics. Regardless of the size, plastics continuously fragment and release plastic additives and other soluble products. Moreover, due to the same molecular composition, the aging mechanisms and characteristics of micro and nanoplastics are similar to those of macroplastics. However, the smaller the particle size, the greater the potential harm. To enhance understanding of the environmental effects of plastics, this review focused on the entire dynamic process from the initial form of plastics to their degradation and summarized the aging mechanisms involved, changes in properties, and the products released during this process. These products include macroplastics, micro and nanoplastics, plastic additives, and other soluble substances. The paper also summarized relevant studies and main conclusions on plastic aging experiments, further exploring factors that influence the leaching of plastic additives and the release of micro and nanoplastic particles. Finally, it provided a summary of the environmental hazards that were caused by plastic aging products.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1850-1860"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"[Screening and Identification of Polyvinyl Chloride-degrading Bacteria and Its Degradation Characteristics].","authors":"Shuai-Bing Wang, Wei Li, Dan-Dan Wang, Chao Wang, Xiang-Hui Yan, Na Geng, Zhi-Guo Zhao, Zhi-Hong Xie","doi":"10.13227/j.hjkx.202402031","DOIUrl":"https://doi.org/10.13227/j.hjkx.202402031","url":null,"abstract":"<p><p>Polyvinyl chloride (PVC) has been shown to be degraded by some insect larvae; however, research is scarce on degrading bacteria. This study revealed that <i>Zophobas atratus</i> larvae were able to keep a higher survival rate only when taking in PVC and reached up to 72.33% within 30 d. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) showed that the peak values of the major functional groups of PVC in the frass changed significantly, and the thermal stability decreased, indicating that PVC biodegraded in the gut of <i>Z. atratus</i>. Based on these, three PVC-degrading bacteria were isolated from the gut contents of the larvae with PVC as the only carbon source in the culture medium for selection, which were identified to be <i>Enterococcus faecalis</i>, <i>Enterobacter hormaechei</i>, and <i>Bacillus subtilis</i>. The degradation test of PVC showed that C5-1 had the greatest degradation efficiency among the three strains, which resulted in the weight loss of (6.19 ± 0.14) mg, and the water contact angle (WCA) decreased by 9.4° within 50 d, effectively improving the hydrophilicity of PVC. In conclusion, the strain C5-1 isolated from the gut of <i>Z. atratus</i> larvae showed the high potential to be applied to the biodegradation of PVC plastics.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1861-1867"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
环境科学Pub Date : 2025-03-08DOI: 10.13227/j.hjkx.202312169
Ya-Bing Guan, Jun Wang, Li Tan, Sheng-Tian Yang, Wen-Wu Zhao, Ke Chen, Xi-Tong Zhang
{"title":"[Estimation of Vegetation Carbon Source/sink and Its Response to Land Use Change in the Loess Plateau,A Case Study of Yanhe River Basin].","authors":"Ya-Bing Guan, Jun Wang, Li Tan, Sheng-Tian Yang, Wen-Wu Zhao, Ke Chen, Xi-Tong Zhang","doi":"10.13227/j.hjkx.202312169","DOIUrl":"https://doi.org/10.13227/j.hjkx.202312169","url":null,"abstract":"<p><p>The transformation of ecosystem types caused by land use change plays an extremely important role in the regional carbon cycle. Studying the response of vegetation carbon source/sink systems to land use change is helpful to improve the understanding of the vegetation carbon sink effect in the process of land use change. However, few studies have focused on the response of vegetation carbon sources/sinks to land use change. The CASA model and soil microbial respiration model were combined to estimate the net ecosystem productivity (NEP) of vegetation in the Yanhe River Basin in the Chinese Loess Plateau from 2000 to 2020 based on remote sensing, meteorological, and land use data. The spatiotemporal pattern evolution characteristics of the carbon source/sink and land use were identified using a significance test, univariate linear regression analysis, and land use status transition matrix methods, and the response of the carbon source/sink to land use change was further analyzed. The results showed that from 2000 to 2020, the multi-year average NEP in the Yanhe River Basin showed a spatial distribution pattern of lower in the upstream and higher in the midstream and downstream. The Yanhe River Basin belonged to a weak carbon sink area as a whole, with this type of area accounting for 88.81% of the basin area. The annual NEP of the basin showed a significant increase trend in fluctuations, and the carbon sequestration capacity was gradually improving. The areas with significant and extremely significant increases in annual NEP accounted for 65.78% of the basin area, and the types of annual NEP restoration, basic stability, and degradation accounted for 79.70%, 10.15%, and 10.15% of the basin area, respectively. Over the past 20 years, the land use transformation of Yanhe River Basin mainly included five types, that is, cropland was converted into grassland, woodland, and construction land, and grassland was converted into cropland and woodland. The land use in the Yanhe River Basin was mainly shifting towards promoting the improvement of the carbon sink capacity, and the transformation of land type to woodland had a more significant effect on improving carbon sink capacity. During the five main land use transformation processes in the Yanhe River Basin, the area ratio of NEP recovery-recovery type for cropland shifting to woodland was the highest at 80.78%. The area ratios of NEP recovery-recovery type for grassland shifting to cropland and cropland shifting to grassland were relatively low, at 48.05% and 51.97%, respectively. The stability of NEP restoration when shifting cropland to woodland was the strongest, and the fluctuation of NEP restoration when shifting between cropland and grassland mutually was strong. When adjusting cropland and grassland mutually, attention should be paid to select suitable vegetation types and increase vegetation coverage reasonably to improve carbon sequestration and sink enhancement capabilities, so as to avo","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1657-1665"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}