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Random gradient-free method for online distributed optimization with strongly pseudoconvex cost functions

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Control Theory and Technology 2024年第1期22卷 14-24页

作者： Xiaoxi yan Cheng Li Kaihong Lu hang Xu School of Electrical and Information Engineering Jiangsu UniversityZhenjiang212013JiangsuChina College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao266590ShandongChina

This paper focuses on the online distributed optimization problem based on multi-agent systems. In this problem, each agent can only access its own cost function and a convex set, and can only exchange local state information with its current neighbors through a time-varying digraph. In addition, the agents do not have access to the information about the current cost functions until decisions are made. Different from most existing works on online distributed optimization, here we consider the case where the cost functions are strongly pseudoconvex and real gradients of the cost functions are not available. To handle this problem, a random gradient-free online distributed algorithm involving the multi-point gradient estimator is proposed. Of particular interest is that under the proposed algorithm, each agent only uses the estimation information of gradients instead of the real gradient information to make decisions. The dynamic regret is employed to measure the proposed algorithm. We prove that if the cumulative deviation of the minimizer sequence grows within a certain rate, then the expectation of dynamic regret increases sublinearly. Finally, a simulation example is given to corroborate the validity of our results.

关键词： Multi-agent system Online distributed optimization Pseudoconvex optimization Random gradient-free method

Fluoro-functionalized plant biomass adsorbent:Preparation and application in extraction of trace perfluorinated compounds from environmental water samples

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Journal of Environmental Sciences 2024年第3期137卷 703-715页

作者： Xi Tan yan Shi Chun-Feng Ma Quan Chi Yu-hang yang Wen-Xiang Zhang Hua-Ming Xiao Xian Wang Key Laboratory of Analytical Chemistry of the State Ethnic Affairs Commission School of Chemistry and Materials ScienceSouth-Central Minzu UniversityWuhan 430074China School of Pharmaceutical Sciences South-Central Minzu UniversityWuhan 430074China Key Laboratory of Oilseeds Processing of Ministry of Agriculture Hubei Key Laboratory of Lipid Chemistry and NutritionOil Crops Research Institute of the Chinese Academy of Agricultural SciencesWuhan 430062China

Perfuorinated compounds(PFCs)are toxic and widely present in the environment,and therefore effective adsorbents are required to remove PFCs from environmental water.In the present study,a new type of fuorinated biomass materials was synthesized via an ingenious fuorosilanization reaction.These adsorbents were applied for the adsorption of 13typical PFCs,including perfuorocarboxylic acids(PFCAs)and perfuorosulfonic acids(PFSAs).By comparing their adsorption performance,Fluorinated cedar slag(FCS)was discovered to have the best absorption efficiency and enabled highly efficient enrichment of PFCs.The adsorption recovery of FCS with the investigated PFCs is greater than 90%under the optimal adsorption condition.Ascribed to the high affinity of F-F sorbent-sorbate interaction,FCS had good adsorption capacities of PFCs from aqueous solution,with the maximum adsorption capacity of 15.80 mg/g for PFOS and 10.71 mg/g for PFOA,respectively.Moreover,the adsorption time could be achieved in a short time(8 min).Using the FCS absorbent,an innovative FCS-solid phase extraction assisted with high performance liquid chromatography-electrospray-tandem mass spectrometry(FCS-SPE-HPLC-ESI-MS/MS)method was first developed to sensitively detect PFCs in the environmental water samples.The intra-day and inter-day recovery rates of the 13 compounds ranged from 90.7%-104.3%,with the RSD of 2.1%-4.7%(intra-day)and 2.5%-8.5%(inter-day),respectively.This research demonstrates the potential of the newly fuoro-functionalized plant biomass to adsorb PFCs from environmental water,with the advantages of high adsorption efficiencies,high antiinterference,easy operation and low economic cost.

关键词： Fluoro-functionalized biomass Perfuorinated compounds(PFCs) Adsorption efficiency Mass spectrometry(MS) Fluorinated cedar slag(FCS)

Laboratory and numerical modelling of irrigation infiltration and nitrogen leaching in homogeneous soils

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Pedosphere 2024年第1期34卷 146-158页

作者： Lei WU Ruizhi LI yan WANG Zongjun GUO Jiaheng LI hang yanG Xiaoyi MA Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling 712100China Blackland Research and Extension Center Texas A&M AgriLife ResearchTexas A&M UniversityTemple TX 76502USA State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China

Nitrogen (N) plays a key role in crop growth and production;however,data are lacking especially regarding the interaction of biochar,grass cover,and irrigation on N leaching in saturated soil profiles.Eighteen soil columns with 20-cm diameter and 60-cm height were designed to characterize the effects of different grass cover and biochar combinations,i.e.,bare soil+0%biochar (control,CK),perennial ryegrass+0%biochar (C1),Festuca arundinacea+0%biochar (C2),perennial ryegrass+1%biochar (C3),perennial ryegrass+2%biochar (C4),perennial ryegrass+3%biochar (C5),F.arundinacea+1%biochar (C6),F.arundinacea+2% biochar (C7),and F.arundinacea+3%biochar (C8),on periodic irrigation infiltration and N leaching in homogeneous loess soils from July to December 2020.Leachates in CK were 10.2%–35.3%higher than those in C1 and C2.Both perennial ryegrass and F.arundinacea decreased the volumes of leachates and delayed the leaching process in the 1%,2%,and 3%biochar treatments,and the vertical leaching rate decreased with biochar addition.The N leaching losses were concentrated in the first few leaching tests,and both total N (TN) and nitrate (NO_(3)^(-))-N concentrations in CK and C1–C8 decreased with increasing leaching test times.Biochar addition (1%,2%,and 3%) could further reduce the leaching risk of NO_(3)^(-)-N and the NO_(3)^(-)-N loss decreased with biochar addition.However,compared to 1%biochar,2% biochar promoted the leaching of TN under both grass cover types.The N leaching losses in CK,C1,C2,C3,C4,C6,and C7 were primarily in the form of NO_(3)^(-)-N.Among these treatments,CK,C1,and C2had the highest cumulative leaching fractions NO_(3)^(-)-N (>90%),followed by those in C3,C4,C6,and C7 (>80%).The cumulative leaching fraction of NO_(3)^(-)-N decreased with increasing leaching test times and biochar addition,and 3%biochar addition (i.e.,C5 and C8) reduced it to approximately 50%.The one-dimensional advective-dispersive-reactive transport equation can be used as an effective numerical approach to simulate and predict NO_(3)^(-

关键词： leaching loss nitrate nitrogen biochar grass cover analytical modelling

Metagenomic analysis revealing the metabolic role of microbial communities in the free amino acid biosynthesis of Monascus rice vinegar during fermentation

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Food Science and Human Wellness 2024年第4期13卷 2317-2326页

作者： hang Gao Jian Zhang Li Liu Lijun Fu yan Zhao Germán Mazza Xin Zhang Beijing Academy of Food Sciences 100068 BeijingChina Institute for Research and Development in Process Engineering Biotechnology and Alternative Energies(PROBIENCONICET-UNCo)8300 NeuquénArgentina

Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains unclear.Through metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar fermentation.Taxonomic profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism pathways.The metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was illuminated.The results revealed that 5 functional genera were closely involved in FAA biosynthesis.This study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.

关键词： Monascus rice vinegar Metagenomic analysis Free amino acid synthesis Metabolic pathway Microbial distribution

Influence of Nd^(3+) concentration on mid-infrared emission in PbF_(2) crystal co-doped with Ho^(3+) and Nd^(3+) ions

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Journal of Rare Earths 2024年第3期42卷 479-487,I0002页

作者： yan Chen Juncheng Tan Peixiong Zhang Weibi Zheng Lin Li Lianhan Zhang Zhen Li Yin hang Zhenqiang Chen Department of Optoelectronic Engineering Jinan UniversityGuangzhou510632China Guangdong Provincial Engineering Research Centerof Crystal and Laser Technology.Guangzhou 510632China Research Center of Laser Crystal Key Laboratory of High Power Laser MaterialsShanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai201800China

A promising series of Ho_(y)Nd_(x)Pb_((1-x-y))F_2(x = 0, 0.01, 0.02, 0.03, 0.04;y = 0.02) crystals was grown by the Bridgman method. The influence of the Nd^(3+)ions concentration on mid-infrared(~2.0, ~2.9 and ~3.9 μm)fluorescence emissions of Ho^(3+)ions in the PbF_(2) crystal excited by 808 nm laser diode was investigated in this work. The energy transfer mechanism between Nd^(3+)ions and Ho~(3+)ions under different concentrations of the Nd^(3+)ions was systematically analyzed. The results show that the Nd^(3+)ions have good sensitization and deactivation effect on the Ho^(3+)ions to stimulate the mid-infrared fluorescence emissions. The experimental analysis proves that the sensitization efficiency of the Nd^(3+)ions is relatively stable at around 93.45% with varying Nd^(3+)-doping concentrations. Concentration dependence studies indicate that the concentration of the Nd^(3+)ions has significant influence on mid-infrared emissions.When the doping concentration of the Nd^(3+)ions is up to 2.0 at%, the intensity of ~2.0, ~2.9 and ~3.9 μm emissions all reach the maximum. The output characteristics of a 3.9 μm laser are simulated, and it is found that with the increase of the Nd^(3+)-doping concentration, the peak power, pulse width, and peak energy all meet the trend of first increasing and then decreasing, and Ho_(0.02)Nd_(0.02)Pb_(0.96)F_(2) crystal displays the best performance. All the results show that the Nd^(3+)/Ho^(3+)co-doped PbF_(2) crystals might act as a useful optical medium for mid-infrared laser applications.

关键词： Crystal growth Mid-infrared PbF_(2) Rare earth ions

Tunable VO_(2) cavity enables multispectral manipulation from visible to microwave frequencies

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Light(Science & Applications) 2024年第3期13卷 510-518页

作者： hang Wei Jinxin Gu Tao Zhao Zhiyuan yan He-Xiu Xu Shuliang Dou Cheng-Wei Qiu Yao Li Center for Composite Materials and Structure Harbin Institute of TechnologyHarbin 150001China National University of Singapore Department of Electrical&Computer EngineeringSingapore 117583Singapore School of Chemical Engineering and Technology Harbin Institute of TechnologyHarbin 150001China Suzhou Laboratory Suzhou 215123China

Optical materials capable of dynamically manipulating electromagnetic waves are an emerging field in memories,optical modulators,and thermal management.Recently,their multispectral design preliminarily attracts much attention,aiming to enhance their efficiency and integration of functionalities.However,the multispectral manipulation based on these materials is challenging due to their ubiquitous wavelength dependence restricting their capacity to narrow wavelengths.In this article,we cascade multiple tunable optical cavities with selective-transparent layers,enabling a universal approach to overcoming wavelength dependence and establishing a multispectral platform with highly integrated functions.Based on it,we demonstrate the multispectral(ranging from 400 nm to 3 cm),fast response speed(0.9 s),and reversible manipulation based on a typical phase change material,vanadium dioxide.Our platform involves tandem VO_(2)-based Fabry–Pérot(F-P)cavities enabling the customization of optical responses at target bands independently.It can achieve broadband color-changing capacity in the visible region(a shift of~60 nm in resonant wavelength)and is capable of freely switching between three typical optical models(transmittance,reflectance,and absorptance)in the infrared to microwave regions with drastic amplitude tunability exceeding 0.7.This work represents a state-of-art advance in multispectral optics and material science,providing a critical approach for expanding the multispectral manipulation ability of optical systems.

关键词： spectral microwave visible

General anesthetic agents induce neurotoxicity through oligodendrocytes in the developing brain

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Zoological Research 2024年第3期45卷 691-703页

作者： Wen-Xin hang yan-Chang yang Yu-Han Hu Fu-Quan Fang Lang Wang Xing-Hua Qian Patrick M.McQuillan Hui Xiong Jian-hang Leng Zhi-Yong Hu Department of Anesthesiology First Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang 310003China Department of Cell Biology Yale UniversityNew HavenCT 06520USA Department of Neurology of the First Affiliated Hospital Interdisciplinary Institute of Neuroscience and TechnologySchool of Brain Science and Brain MedicineZhejiang University School of MedicineHangzhouZhejiang 310027China Department of Anesthesiology Jiaxing Maternity and Childcare Health HospitalJiaxingZhejiang 314009China Department of Anesthesiology Penn State Hershey Medical CentrePenn State College of MedicineHersheyPA 17033USA Department of Central Laboratory Affiliated Hangzhou First People’s HospitalWestlake University School of MedicineHangzhouZhejiang 310006China

General anesthetic agents can impact brain function through interactions with neurons and their effects on glial cells.Oligodendrocytes perform essential roles in the central nervous system,including myelin sheath formation,axonal metabolism,and neuroplasticity regulation.They are particularly vulnerable to the effects of general anesthetic agents resulting in impaired proliferation,differentiation,and apoptosis.Neurologists are increasingly interested in the effects of general anesthetic agents on oligodendrocytes.These agents not only act on the surface receptors of oligodendrocytes to elicit neuroinflammation through modulation of signaling pathways,but also disrupt metabolic processes and alter the expression of genes involved in oligodendrocyte development and function.In this review,we summarize the effects of general anesthetic agents on oligodendrocytes.We anticipate that future research will continue to explore these effects and develop strategies to decrease the incidence of adverse reactions associated with the use of general anesthetic agents.

关键词： Oligodendrocytes General anesthetic agents Neurotoxicity Central nervous system Perioperative neurocognitive disorders

Characteristics and source apportionment of ambient volatile organic compounds and ozone generation sensitivity in urban Jiaozuo,China

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Journal of Environmental Sciences 2024年第4期138卷 607-625页

作者： Pengzhao Li Chun Chen Dan Liu Jie Lian Wei Li Chuanyi Fan Liangyu yan Yue Gao Miao Wang hang Liu Xiaole Pan Jing Mao State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Henan Key Laboratory of Environmental Monitoring Technology Henan Ecological Environment Monitoring and Safety CenterZhengzhou 450046China Jiaozuo Ecological Environment Monitoring Center of Henan Province Jiaozuo 454003China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

In recent years,many cities have taken measures to reduce volatile organic compounds(VOCs),an important precursor of ozone(O_(3)),to alleviate O_(3) pollution in China.116 VOC species were measured by online and offline methods in the urban area of Jiaozuo from May to October in 2021 to analyze the compositional characteristics.VOC sources were analyzed by a positive matrix factorization(PMF)model,and the sensitivity of ozone generation was determined by ozone isopleth plotting research(OZIPR)simulation.The results showed that the average volume concentration of total VOCs was 30.54 ppbv and showed a bimodal feature due to the rush-hour traffic in the morning and at nightfall.The most dominant VOC groups were oxygenated VOCs(OVOCs,29.3%)and alkanes(26.7%),and the most abundant VOC species were acetone and acetylene.However,based on the maximum incremental reactivity(MIR)method,the major VOC groups in terms of ozone formation potential(OFP)contribution were OVOCs(68.09μg/m^(3),31.5%),aromatics(62.90μg/m^(3),29.1%)and alkene/alkynes(54.90μg/m^(3),25.4%).This indicates that the control of OVOCs,aromatics and alkene/alkynes should take priority.Five sources of VOCs were quantified by PMF,including fixed sources of fossil fuel combustion(27.8%),industrial processes(25.9%),vehicle exhaust(19.7%),natural and secondary formation(13.9%)and solvent usage(12.7%).The empirical kinetic modeling approach(EKMA)curve obtained by OZIPR on O_(3) exceedance days indicated that the O_(3) sensitivity varied in different months.The results provide theoretical support for O_(3) pollution prevention and control in Jiaozuo.

关键词： Volatile organic compounds(VOCs) Online and offline measurement Ozone formation potential(OFP) Positive matrix factorization(PMF) Ozone isopleth plotting research(OZIPR) Jiaozuo

General anesthetic agents induce neurotoxicity through astrocytes

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Neural Regeneration Research 2024年第6期19卷 1299-1307页

作者： yanchang yang Tiantian Liu Jun Li Dandan yan Yuhan Hu Pin Wu Fuquan Fang Patrick M.McQuillan Wenxin hang Jianhang Leng Zhiyong Hu Department of Anesthesiology The First Affiliated Hospital Zhejiang University School of Medicine Department of Anesthesiology Ningbo Women and Children's Hospital 3. Department of Anesthesiology Shulan (Hangzhou) Hospital Affiliated to Zhejiang Shuren University Shulan International Medical College 4. Cell Biology Department Yale University 5. Department of Anesthesiology Penn State Hershey Medical Centre Penn State College of Medicine 6. Department of Central Laboratory Affiliated Hangzhou First People's Hospital Zhejiang University School of Medicine

Neuroscientists have recognized the importance of astrocytes in regulating neurological function and their influence on the release of glial transmitters. Few studies, however, have focused on the effects of general anesthetic agents on neuroglia or astrocytes. Astrocytes can also be an important target of general anesthetic agents as they exert not only sedative, analgesic, and amnesic effects but also mediate general anesthetic-induced neurotoxicity and postoperative cognitive dysfunction. Here, we analyzed recent advances in understanding the mechanism of general anesthetic agents on astrocytes, and found that exposure to general anesthetic agents will destroy the morphology and proliferation of astrocytes, in addition to acting on the receptors on their surface, which not only affect Ca2+signaling, inhibit the release of brain-derived neurotrophic factor and lactate from astrocytes, but are even involved in the regulation of the pro-and anti-inflammatory processes of astrocytes. These would obviously affect the communication between astrocytes as well as between astrocytes and neighboring neurons, other neuroglia, and vascular cells. In this review, we summarize how general anesthetic agents act on neurons via astrocytes, and explore potential mechanisms of action of general anesthetic agents on the nervous system. We hope that this review will provide a new direction for mitigating the neurotoxicity of general anesthetic agents.

关键词： astrocytes brain-derived neurotrophic factor general anesthetic agents N-methyl-D-aspartate receptor neuron neurotoxicity perioperative neurocognition Toll-like receptor γ-aminobutyric acid receptor