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Missing microbes in infants and children in the COVID-19 pandemic:a study of 1,126 participants in Beijing,China

Science China(Life Sciences) 2024年第8期67卷 1739-1750页

作者： Jiejing Wang Yuejuan Li Yu Mu Kefei Huang Danyi Li Canhui Lan Yutao Cui Jun Wang CAS Key lab for pathogenic Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Beijing Dr.CUIYUTAO Clinic Beijing 100028China R-Institute Co.Ltd. Beijing 100011China

The COVID-19 pandemic has caused many fatalities worldwide and continues to affect the health of the recovered patients in the form of *** this study,we compared the gut microbiome of uninfected infants and children before the pandemic began(BEFORE cohort,n=906)to that of after the pandemic(AFTER cohort,n=220)to examine the potential impact of social distancing and life habit changes on infant/children gut *** on 16S rRNA sequencing,we found a significant change in microbiome composition after the pandemic,with Bacteroides enterotype increasing to 35.45%from 30.46%before the *** quantification indicated that the bacterial loads of seven keystone taxa decreased by 91.69%–19.58%.Quantitative microbiome profiling,used to enhance the resolution in detecting microbiome differences,revealed a greater explained variance of pandemic on microbiome compared to gender,as well as a significant decrease in bacterial loads in 15 of the 20 major *** random forest age-predictor indicated the gut microbiomes were less mature in the after-pandemic cohort than in the before-pandemic cohort in the children group(3–12 years old)and had features of a significantly younger age(average of 1.86 years).Lastly,body weight and height were significantly lower in the after-pandemic cohort than in the before-pandemic cohort in infants(<1 year of age),which was associated with a decrease in bacterial loads in the fecal microbiome.

关键词： gut microbiome COVID-19 pandemic quantitative microbiome profiling children health

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Electrical tree degradation of MgO/epoxy resin composites at different voltage frequencies

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HIGH VOLTAGE 2024年第3期9卷 581-590页

作者： Zhang, Yunxiao Lin, Wenxin Zhou, Yuanxiang Xing, Weiwei Cheng, Jiayu Teng, Chenyuan Fuzhou Univ Coll Elect Engn & Automat Fujian Key Lab New Energy Generat & Power Convers Fuzhou Peoples R China Tsinghua Univ Dept Elect Engn State Key Lab Control & Simulat Power Syst & Gener Beijing Peoples R China

Electrical tree degradation is one of the main causes of insulation failure in high-frequency transformers. Electrical tree degradation is studied on pure epoxy resin (EP) and MgO/EP composites at frequencies ranging from 50 Hz to 130 kHz. The results show that the tree initiation voltage of EP decreases, while the growth rate and the expansion coefficient increase with frequency. Moreover, the bubble phenomenon at high frequencies in EP composites is discussed. Combined with trap distribution characteristics within the material, the intrinsic mechanism of epoxy composites to inhibit the growth of the electrical tree at different frequencies is discussed. It can be concluded that more deep traps and blocking effect are introduced by doping nano-MgO into EP bulks, which can improve the electrical tree resistance performance of EP composites in a wide frequency range.

关键词： EPOXY-RESIN PARTIAL DISCHARGE CABLE INSULATION SILICONE-RUBBER GROWTH WAVE TEMPERATURE DEPENDENCE EVOLUTION

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Effects of Rattling Behavior of K and Cd Atoms along Different Directions in Anisotropic KCdAs on Lattice Thermal Transport and Thermoelectric Properties

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 388-398页

作者： Wang, Yue Zhao, Yinchang Ni, Jun Dai, Zhenhong Yantai Univ Dept Phys Yantai 264005 Peoples R China Tsinghua Univ Dept Phys State Key Lab Low Dimens Quantum Phys Beijing 100084 Peoples R China Frontier Sci Ctr Quantum Informat Beijing 100084 Peoples R China

We employ advanced first principles methodology, merging self-consistent phonon theory and the Boltzmann transport equation, to comprehensively explore the thermal transport and thermoelectric properties of KCdAs. Notably, the study accounts for the impact of quartic anharmonicity on phonon group velocities in the pursuit of lattice thermal conductivity and investigates 3ph and 4ph scattering processes on phonon lifetimes. Through various methodologies, including examining atomic vibrational modes and analyzing 3ph and 4ph scattering processes, the article unveils microphysical mechanisms contributing to the low kappa(L) within KCdAs. Key features include significant anisotropy in Cd atoms, pronounced anharmonicity in K atoms, and relative vibrations in non-equivalent As atomic layers. Cd atoms, situated between As layers, exhibit rattling modes and strong lattice anharmonicity, contributing to the observed low kappa(L). Remarkably flat bands near the valence band maximum translate into high PF, aligning with ultralow kappa(L) for exceptional thermoelectric performance. Under optimal temperature and carrier concentration doping, outstanding ZT values are achieved: 4.25 (a(b)-axis, p-type, 3 x 10(19) cm(-3), 500 K), 0.90 (c-axis, p-type, 5 x 10(20) cm(-3), 700 K), 1.61 (a(b)-axis, n-type, 2 x 10(18) cm(-3), 700 K), and 3.06 (c-axis, n-type, 9 x 10(17) cm(-3), 700 K).

关键词： anharmonic lattice dynamics electron transport characteristics first principles calculation lattice thermal transport octahedron thermoelectric properties TOTAL-ENERGY CALCULATIONS FIGURE CONDUCTIVITY MERIT CRYSTALS LIMIT HEAT PBSE PBTE

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Enhancing photovoltaic energy forecasting: a progressive approach using wavelet packet decomposition

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CLEAN ENERGY 2024年第3期8卷 95-108页

作者： Ferkous, Khaled Guermoui, Mawloud Bellaour, Abderahmane Boulmaiz, Tayeb Bailek, Nadjem Univ Ghardaia LMTESE Lab Mat Technol Energy Syst & Environm Ghardaia 47000 Algeria Renewable Energy Appl Res Unit URAER Ghardaia 47000 Algeria Ahmed Draia Adrar Univ Fac Sci & Technol Dept Math & Comp Sci Lab Math Modeling & Applicat Adrar 01000 Algeria

Accurate photovoltaic (PV) energy forecasting plays a crucial role in the efficient operation of PV power stations. This study presents a novel hybrid machine-learning (ML) model that combines Gaussian process regression with wavelet packet decomposition to forecast PV power half an hour ahead. The proposed technique was applied to the PV energy database of a station located in Algeria and its performance was compared to that of traditional forecasting models. Performance evaluations demonstrate the superiority of the proposed approach over conventional ML methods, including Gaussian process regression, extreme learning machines, artificial neural networks and support vector machines, across all seasons. The proposed model exhibits lower normalized root mean square error (nRMSE) (2.116%) and root mean square error (RMSE) (208.233 kW) values, along with a higher coefficient of determination (R2) of 99.881%. Furthermore, the exceptional performance of the model is maintained even when tested with various prediction horizons. However, as the forecast horizon extends from 1.5 to 5.5 hours, the prediction accuracy decreases, evident by the increase in the RMSE (710.839 kW) and nRMSE (7.276%), and a decrease in R2 (98.462%). Comparative analysis with recent studies reveals that our approach consistently delivers competitive or superior results. This study provides empirical evidence supporting the effectiveness of the proposed hybrid ML model, suggesting its potential as a reliable tool for enhancing PV power forecasting accuracy, thereby contributing to more efficient grid management. This study proposes a new method for forecasting solar power generation 30 minutes ahead. It combines Gaussian process regression with wavelet packet decomposition to capture complex patterns in historical data. This approach outperforms other forecasting models across different seasons and forecast horizons. Graphical Abstract

关键词： short photovoltaic power forecasting wavelet packet decomposition sub-series reconstruction machine learning in energy forecasting sustainable power stations renewable energy DATA-DRIVEN MACHINE

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Nanodiamond-Assisted High Performance Lithium and Sodium Ions Co-Storage

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 94-105页

作者： Sun, Xiaochen Gao, Xuan Su, Chang Cheng, Wei Gao, Nan Zhang, Xin Gong, Mengmeng Dong, Haobo Dai, Yuhang He, Guanjie Li, Hongdong Jilin Univ Coll Phys State Key Lab Superhard Mat Changchun 130012 Peoples R China UCL Dept Chem Christopher Ingold Lab 20 Gordon St London WC1H 0AJ England Univ Oxford Nuffield Coll New Rd Oxford OX1 1NF England

While lithium resources are scarce for high energy-dense lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), serving as an alternative, inherently suffer from low capacity and the high-cost use of non-graphite anodes. Combining Li- and Na-ions within a single battery system is expected to mitigate the shortcomings of both systems while leveraging their respective advantages. In this study, we developed and assembled a nanodiamonds (NDs)-assisted co-Li/Na-ion battery (ND-LSIB). This innovative battery system comprised a commercial graphite anode, an ND-modified polypropylene (DPP) separator, a hybrid lithium/sodium-based electrolyte, and a cathode. It is theoretically and experimentally demonstrated that the ND/Li co-insertion can serve as an ion-drill opening graphite layers and reconstructing graphite anodes into few-layered graphene with expanding interlayer space, achieving highly efficient Li/Na storage and the theoretical maximum of LiC6 for Li storage in graphite. In addition, ND is helpful for creating a LiF-/NaF-rich hybrid solid electrolyte interface with improved ionic mobility, mechanical strength, and reversibility. Consequently, ND-LSIBs have higher specific capacities similar to 1.4 times the theoretical value of LIBs and show long-term cycling stability. This study proposes and realizes the concept of Li/Na co-storage in one ion battery with compatible high-performance, cost-effectiveness, and industrial prospects.

关键词： BATTERIES GRAPHITE HYBRID ANODE COMPOSITE

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Green hydrogen production from photovoltaic power station as a road map to climate change mitigation

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CLEAN ENERGY 2024年第2期8卷 156-167页

作者： Kamil, Kehinde Ridwan Samuel, Bassey Okon Khan, Umar Edge Hill Univ Dept Comp Sci & Engn Ormskirk England ENEL Green Power Rome Italy Steelagon Engn Ltd Mat Res Lab Sabon Gari Kaduna State Nigeria

The increasing recognition of hydrogen as a critical element in the global net-zero transition and its clear role in decarbonizing challenging sectors coincide with the growing urgency to address climate change. Africa's favourable renewable-energy capacity, ranging from 28% to 36% for solar, has been reported by the global solar irradiance index. However, the majority of hydrogen production today relies on fossil fuels (96%), with only a small fraction (4%) being produced through water electrolysis. Even though there have been many studies on climate change mitigation with a focus on Africa, a green hydrogen production from a photovoltaic power station approach has not been reported. Also, literature with a focus on Nigeria is lacking. This study focuses on the African green hydrogen production industry, utilizing Nigeria as a case study to explore the feasibility of generating clean hydrogen vectors from a percentage of photovoltaic power output in various regions of the country through stand-alone solar grid electrification projects. Analyses of the usage and effectiveness of the produced hydrogen fuel in each region are carried out, with the highest region having an annual output of 12 247 278 kg of green hydrogen and 8 573 094 kg of ammonia and the lowest region having an output of 511 245 kg of green hydrogen and 357 871 kg of ammonia, and the expected production from the proposed usage of 50% of the power generation output of the installed 1.6-MWp and 80-kWp solar power minigrids in the regions is calculated. The analyses were repeated for the other considered regions in the country. The results showcased the enormous advantages of the electrolytic production of hydrogen and how the greener economy project can play a major role in mitigating climate change effects and overreliance on fossil fuels as the driver of the economy in many African countries. Nigeria is used as a case study for the African green hydrogen production industry to explore the feasibility

关键词： renewable energy photovoltaic climate change green hydrogen vector fossil fossil fuels decarbonization electrolysis AMMONIA WATER CELL

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Enhanced heavy and extra heavy oil recovery: Current status and new trends

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PETROLEUM 2024年第3期10卷 399-410页

作者： Gomaa, Sayed Salem, Khalaf G. El-hoshoudy, A. N. Al Azhar Univ Fac Engn Min & Petr Engn Dept Cairo Egypt South Valley Egyptian Petr Holding Co GANOPE Dept Reservoir Engn Cairo Egypt Egyptian Petr Res Inst PVT Lab Prod Dept Cairo 11727 Egypt Egyptian Petr Res Inst EPRI PVT Serv Ctr Cairo 11727 Egypt

Due to the increased demand for energy resources these days, especially due to the Russian-Ukrainian war, the focus of the major countries is turning strongly towards improving oil production, especially heavy and extra heavy oil, which represents 40% of the world oil reserve. Steam-based and thermal (EOR) procedures are promising techniques for recovering heavy oil reservoirs, but they suffer from a sequence of problems and complications that arise after long-term application. These complications comprise steam breakthrough, steam overlap, and steam/rock interactions. This research presents the currently applied techniques to maximize the productivity of heavy oil, such as steam injection, cyclic steam stimulation, in-situ combustion, and steam-assisted gravity drainage. Thermal technologies face numerous obstacles, as they are energy and water-intensive processes that are not environmentally friendly. The research also presents future trends in energy-saving and environmentally friendly techniques that enhance heavy oil recovery through vapor extraction (VAPEX) steam-solvent hybrid techniques, electromagnetic energy, sonication, and nanotechnology. The findings of this review reported that all the presented techniques focus on how to reduce the oil viscosity and in-situ upgrade the crude oil properties. In turn, these enhance both the productivity rate and oil recovery and minimize the production cost. This article can be considered a comprehensive review of thermal recovery methods in heavy and extra-heavy oil, in addition to screening criteria used for each method. (c) 2023 Southwest Petroleum University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http:// ***/licenses/by-nc-nd/4.0/).

关键词： Enhanced oil recovery Heavy crude oil Steam flood Hybrid techniques Nanotechnology IN-SITU-COMBUSTION ASSISTED GRAVITY-DRAINAGE CYCLIC-STEAM-STIMULATION ROCK WETTABILITY VAPOR EXTRACTION INJECTION PERFORMANCE BITUMEN SAGD EOR

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A non-antibiotic organic coating on ZA6-1 surface releasing different concentrations of sodium dodecyl sulphate/levulinic acid for orthopaedic application

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BIOSURFACE AND BIOTRIBOLOGY 2024年第2期10卷 42-51页

作者： Zou, Feng Zhao, Deren Liu, Yangkai Lu, Qiqi Liu, Hulin Chen, Zilin Fang, Yaxing Tan, Xiaodong Xiang, Yunjie Feng, Xue Zhang, Yongping Rao, Xi Southwest Univ Sch Mat & Energy Chongqing Peoples R China Southwest Univ Chongqing Key Lab Soft Matter Mat Chem & Funct Mfg Chongqing Peoples R China Chongqing Med Univ Univ Town Hosp Dept Clin Lab Chongqing Peoples R China

Bone implantation surgery is often accompanied by bacterial infection, resulting in infectious bone non-union, pathological fracture and other serious consequences, which will aggravate the pain of patients. A non-antibiotic coating consisting of sodium dodecyl sulphate (SDS) and levulinic acid (LA) with different concentrations was prepared by the authors on the zinc-aluminium alloy (ZA6-1) using a wet chemistry treatment for orthopaedic application. The influence of SDS/LA concentrations on the surface morphology, composition and performance of the developed coating was investigated. The results showed that as-prepared coating on a zinc alloy surface could improve the substrate's corrosion resistance and increase the degradation rate from 0.82 to 19.70 mu m/year upon raising the SDS/LA concentration. Furthermore, higher hydrophilicity (100%) and morphology, as well as good cell adhesion and differentiation (ALP >95% for 7 days) were observed on coated zinc alloys. The increased SDS/LA concentration slightly weakens the biocompatibility and enhances the antibacterial performance of coated zinc alloys due to the synergistic effect of SDS/LA. Overall, the coating comprising 6 wt.% SDS and 9 wt.% LA showed excellent antibacterial action with a high level of biocompatibility, confirming its potential application for orthopaedic implants.

关键词： antibacterial biocompatibility biomaterials material property IN-VITRO ALLOY ANTIBACTERIAL ZINC BEHAVIOR CELLS BIODEGRADATION SANITIZER NANOTUBES MECHANISM

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Technological parameters of thin-film pulsed laser scribing for perovskite photovoltaics

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CLEAN ENERGY 2024年第3期8卷 127-135页

作者： Ishteev, Rustam Gostishchev, Pavel Tiukhova, Mariia Sorokin, Anton Ishteev, Arthur Kondratenko, Vladimir RTU MIREA Inst Adv Technol & Ind Programming Dept Nanoelect Lab Precis Machining Mat Moscow Russia Res & Pract Clin Ctr Diagnost & Telemed Technol Moscow Hlth Care Dept Moscow Russia Natl Univ Sci & Technol MISIS Lab Adv Solar Energy LASE 4 Leninsky St Moscow Russia Russian Acad Sci RAS Semenov Fed Res Ctr Chem Phys 4 Kosygina Str Moscow Russia

Over the past decade, the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%. The significant efficiency growth and the relative simplification of the technology for obtaining thin-film solar cells due to liquid printing methods determine the high potential for the low-cost perovskite solar cells manufacturing. However, efficient use of cell geometry is comparable to the size of standard crystalline-Si wafers (156:156 mm and more). Therefore, modular geometry similar to amorphous-Si solar cell approaches is used to scale perovskite solar cells. Serial electrical connection of thin-film cells requires precise processing of the conductive layers that form the device p-i-n structure. The subject of research is the development of a full pulsed laser scribing cycle for inverted perovskite solar cells. In this work, we propose a study of a laser-patterning technology In2O3:SnO2 (ITO) conductive layer and a photoactive perovskite layer Cs0,2(CH(NH2)2)0,8PbI3. Process regimes of transparent conducting electrodes based on ITO and halide perovskite layer Cs0,2(CH(NH2)2)0,8PbI3 laser patterning were obtained. The optimal parameters for the multipass mode processing of ITO and perovskite layer were determined. The cell was electrically isolated at a scribe line width of 30 mu m. A full pulsed-laser scribing cycle for inverted perovskite solar cells is developed and applied to laser-patterning of an indium-tin oxide (ITO) conductive layer and a photoactive perovskite layer. The optimal parameters for the multipass mode processing of ITO and perovskite layers are determined. Graphical Abstract

关键词： patterning perovskite solar cell perovskite solar cell photovoltaics scribing SOLAR MODULES CELLS

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Ultrasensitive Indium Phosphide Nanomembrane Wearable Gas Sensors

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 209-217页

作者： Wei, Shiyu Haggren, Tuomas Li, Zhe Tan, Hark Hoe Jagadish, Chennupati Tricoli, Antonio Fu, Lan Australian Natl Univ Res Sch Phys Ctr Excellence Transformat Meta Opt Syst Australian Res CouncilDept Elect Mat Engn Canberra ACT 2600 Australia Australian Natl Univ Coll Sci Res Sch Chem Nanotechnol Res Lab Canberra ACT 2600 Australia Univ Sydney Fac Engn Nanotechnol Res Lab Camperdown NSW 2006 Australia

Air quality is deteriorating due to continuing urbanization and industrialization. In particular, nitrogen dioxide (NO2) is a biologically and environmentally hazardous byproduct from fuel combustion that is ubiquitous in urban life. To address this issue, we report a high-performance flexible indium phosphide nanomembrane NO2 sensor for real-time air quality monitoring. An ultralow limit of detection of similar to 200 ppt and a fast response have been achieved with this device by optimizing the film thickness and doping concentration during indium phosphide epitaxy. By varying the film thickness, a dynamic range of values for NO2 detection from parts per trillion (ppt) to parts per million (ppm) level have also been demonstrated under low bias voltage and at room temperature without additional light activation. Flexibility measurements show an adequately stable response after repeated bending. On-site testing of the sensor in a residential kitchen shows that NO2 concentration from the gas stove emission could exceed the NO2 Time Weighted Average limit, i.e., 200 ppb, highlighting the significance of real-time monitoring. Critically, the indium phosphide nanomembrane sensor element cost is estimated at <0.1 US$ due to the miniatured size, nanoscale thickness, and ease of fabrication. With these superior performance characteristics, low cost, and real-world applicability, our indium phosphide nanomembrane sensors offer a promising solution for a variety of air quality monitoring applications.

关键词： air quality monitoring flexible III-V semiconductors nanofilm ultrathin REUSE

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