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Free radicals trigger the closure of open pores in lignin-derived hard carbons toward improved sodium-storage capacity

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Journal of Energy Chemistry 2024年第7期94卷 551-559页

作者： Wen-Jun Ji Zong-Lin Yi ming-Xin song Xiao-Qian Guo Yi-Lin Wang Yi-Xuan Mao Fang-Yuan Su Jing-Peng chen Xian-Xian Wei Li-Jing Xie cheng-Meng chen CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001ShanxiChina University of Chinese Academy of Sciences Beijing 100049China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Environment and Safety Taiyuan University of Science and TechnologyTaiyuan 030001ShanxiChina

The chemical activation of various precursors is effective for creating additional closed pores in hard carbons for sodium ***,the formation mechanism of closed pores under the influence of pore-forming agents is not well ***,an effective chemical activation followed by a high-temperature self-healing strategy is employed to generate interconnected closed pores in lignin-derived hard carbon(HCs).By systematic experimental design combined with electron paramagnetic res-onance spectroscopy,it can be found that the content of free radicals in the carbon matrix influences the closure of open pores at high *** high activation temperature(>700 C)leads to a low free radical concentration,making it difficult to achieve self-healing of open pores at high *** activation at 700°C,a balance between pore making and self-healing is achieved in the final hard carbon.A large number of free radicals triggers rapid growth and aggregation of carbon microcrys-tals,blocking pre-formed open micropores and creating additional interconnected closed pores in as-obtained hard *** a result,the optimized carbon anode(LK-700-1300)delivers a high reversible capacity of 330.8 mA h g^(-1) at 0.03 A g^(-1),which is an increase of 86 mA h g^(-1) compared to the pristine lignin-derived carbon anode(L-700-1300),and exhibits a good rate performance(202.1 mA h g^(-1) at 1 A g^(-1)).This work provides a universal and effective guidance for tuning closed pores of hard carbons from otherprecursors.

关键词： Hard carbon Chemical activation Free radical Self-healing Closed pores Sodium ion batteries

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Hot deformation behavior of a Sr-modified Al-Si-Mg alloy:Constitutive model and processing maps

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Transactions of Nonferrous Metals Society of China 2018年第4期28卷 592-603页

作者： Y.C.LIN Shun-cun LUO Xing-you JIANG Yi TANG ming-song chen School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China Light Alloy Research Institute Central South UniversityChangsha 410083China State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China

Isothermal compression experiments were conducted to study the hot deformation behaviors of a Sr-modified Al-Si-Mg alloy in the temperature range of 300-420°C and strain rate range of 0.01-10 s-1.A physically-based model was developed to accurately predict the flow ***,processing maps were established to optimize hot working *** is found that decreasing the strain rate or increasing the deformation temperature reduces the flow *** high activation energy is closely related to the pinning of dislocations from Si-containing ***,the deformed grains and the Si-containing dispersoids in the matrix are elongated perpendicular to the compression direction,and incomplete dynamic recrystallization(DRX)is discovered on the elongated boundaries in domain with peak *** flow instability is mainly attributed to the flow localization,brittle fracture of eutectic Si phase,and formation of adiabatic shear *** optimum hot working window is 380-420°C and 0.03-0.28 s-1.

关键词： Al-Si-Mg alloy constitutive model processing map microstructure

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Neutron irradiation influence on high-power thyristor device under fusion environment

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Nuclear Science and Techniques 2024年第4期35卷 65-81页

作者： Wei Tong Hua Li Meng Xu Zhi-Quan song Bo chen School of Electrical Engineering and Automation Hefei University of TechnologyHefei 230009China Institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China

Because of their economy and applicability,high-power thyristor devices are widely used in the power supply systems for large fusion *** high-dose neutrons produced by deuterium–tritium(D–T)fusion reactions are irradiated on a thyristor device for a long time,the electrical characteristics of the device change,which may eventually cause irreversible *** this study,with the thyristor switch of the commutation circuit in the quench protection system(QPS)of a fusion device as the study object,the relationship between the internal physical structure and external electrical parameters of the irradiated thyristor is ***,a series of targeted thyristor physical simulations and neutron irradiation experiments are conducted to verify the accuracy of the theoretical *** addition,the effect of irradiated thyristor electrical characteristic changes on the entire QPS is studied by accurate simulation,providing valuable guidelines for the maintenance and renovation of the QPS.

关键词： Fusion device Neutron irradiation effects Thyristor Quench protection

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Distribution and geochemical significance of alkylbenzenes for crude oil with different depositional environments and thermal maturities

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Petroleum Science 2024年第2期21卷 777-790页

作者： Bing-Kun Meng Dao-Fu song Yuan chen Sheng-Bao Shi School of Petroleum Engineering and Environmental Engineering Yan'an UniversityYan'an716000ShaanxiChina State Key Laboratory of Petroleum Resources and Prospecting College of GeosciencesChina University of PetroleumBeijing102249China

A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and songliao Basin using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GCTOFMS).By analyzing the distribution characteristics of C0-C5alkylbenzenes,it is found that the content of some alkylbenzenes varies greatly in crude *** on the distribution characteristics of 1,2,4,5-tetramethylbenzene(Te MB)and 1,2,3,4-Te MB,the ratio of 1,2,4,5-Te MB to 1,2,3,4-Te MB is proposed to indicate the organic matter origin and depositional environment of ancient *** samples originated mainly from lower hydrobiont,algae,bacteria and source rocks deposited under reducing/anoxic conditions have low 1,2,4,5-/1,2,3,4-Te MB values(less than 0.6),while oil samples originated mainly from terrestrial higher plants and source rocks deposited under oxic/sub-oxic conditions have higher 1,2,4,5-/1,2,3,4-Te MB values(greater than 1.0).The significant difference of 1,2,4,5-/1,2,3,4-Te MB values is controlled by 1,2,4,5-Te MB content.1,2,4,5-Te MB content in oils derived from source rocks deposited in oxidized sedimentary environment(greater than 1.0 mg/g whole oil)is higher than that in oils from source rocks deposited in reduced sedimentary environment(less than 1.0 mg/g whole oil).1,2,4,5-/1,2,3,4-Te MB ratio might not or slightly be affected by evaporative fractionation,biodegradation and thermal maturity.1,2,4,5-/1,2,3,4-Te MB ratio and 1,2,4,5-Te MB content can be used as supplementary parameter for the identification of sedimentary environment and organic matter *** should be noted that compared to the identification of organic matter sources,the 1,2,4,5-/1,2,3,4-Te MB parameter is more effective in identifying sedimentary environments.

关键词： 1 2 4 5-Tetramethylbenzene GC×GC-TOFMS Organic matter origin Depositional environment

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A Novel Graph Structure Learning Based Semi-Supervised Framework for Anomaly Identification in Fluctuating IoT Environment

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 3001-3016页

作者： Weijian song Xi Li Peng chen Juan chen Jianhua Ren Yunni Xia School of Computer and Software Engineering Xihua UniversityChengdu610039China West China Second University Hospital Sichuan UniversityChengdu610065China School of Computer Science Chongqing UniversityChongqing400044China

With the rapid development of Internet of Things(IoT)technology,IoT systems have been widely applied in health-care,transportation,home,and other ***,with the continuous expansion of the scale and increasing complexity of IoT systems,the stability and security issues of IoT systems have become increasingly ***,it is crucial to detect anomalies in the collected IoT time series from various ***,deep learning models have been leveraged for IoT anomaly ***,owing to the challenges associated with data labeling,most IoT anomaly detection methods resort to unsupervised learning ***,the absence of accurate abnormal information in unsupervised learning methods limits their *** address these problems,we propose AS-GCN-MTM,an adaptive structural Graph Convolutional Networks(GCN)-based framework using a mean-teacher mechanism(AS-GCN-MTM)for anomaly *** performs better than unsupervised methods using only a small amount of labeled *** Teachers is an effective semi-supervised learning method that utilizes unlabeled data for training to improve the generalization ability and performance of the ***,the dependencies between data are often unknown in time series *** solve this problem,we designed a graph structure adaptive learning layer based on neural networks,which can automatically learn the graph structure from time series *** not only better captures the relationships between nodes but also enhances the model’s performance by augmenting key *** have demonstrated that our method improves the baseline model with the highest F1 value by 10.4%,36.1%,and 5.6%,respectively,on three real datasets with a 10%data labeling rate.

关键词： IoT multivariate time series anomaly detection graph learning semi-supervised mean teachers

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Total suprarenal aortic occlusion with cardiac disease: a case series of three cases

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World Journal of Emergency Medicine 2024年第1期15卷 59-61页

作者： Yuanli Lei Jiaozhen chen Qin chen Jiana Yin Weijia Huang Wenxing song Shouquan chen Department of Emergency Medicine the First Affi liated Hospital of Wenzhou Medical UniversityWenzhou 325000China Department of Electrocardiogram Wenzhou People's HospitalWenzhou 325000China

Acute aortic occlusion(AAO)has been very rarely reported in the literature and is a potentially life-threatening emergency.[1-5]AAO mostly occurs in cardiac disease patients,[1-4,6,7]and leads to cardiac complications.[1,2,5,6]Suprarenal aortic occlusion(SAO)is a very rare type of AAO,and infrarenal aortic occlusion(IAO)accounts for 75.8%-97.8%.[1,3,5-7]SAO is different from IAO in some clinical manifestations,treatment strategies,and prognoses.[3,6-8]SAO with cardiac disease will make the condition more complex and could easily cause a delay in diagnosis and portend worse outcomes with amputation and mortality rates.[1,3,6]Early and fast diagnosis and positive revascularization treatment are necessary to prevent cases from becoming fatal.[1-3]Herein,we present a case series of SAO with cardiac disease.

关键词： cardiac occlusion diagnosis

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Experimental Study on the Effect of Increased Downstroke Duration for an FWAV with Morphing-coupled Wing Flapping Configuration

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Journal of Bionic Engineering 2024年第1期21卷 192-208页

作者： Ang chen Bifeng song ZhiheWang Kang Liu Dong Xue Xiaojun Yang School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China Harbin Institute of Technology Shenzhen 518055China

This paper is based on a previously developed bio-inspired Flapping Wing Aerial Vehicle(FWAV),RoboFalcon,which can fly with a morphing-coupled flapping *** this paper,a simple flapping stroke control system based on Hall effect sensors is designed and applied,which is capable of assigning different up-and down-stroke speeds for the RoboFalcon platform to achieve an adjustable downstroke *** aerodynamic and power characteristics of the morphing-coupled flapping pattern and the conventional flapping pattern with varying downstroke ratios are measured through a wind tunnel experiment,and the corresponding aerodynamic models are developed and analyzed by the nonlinear least squares *** relatively low power consumption of the slow-downstroke mode of this vehicle is verified through outdoor flight *** results of wind tunnel experiments and flight tests indicate that increased downstroke duration can improve aerodynamic and power performance for the RoboFalcon platform.

关键词： Flapping wing aerial vehicle(FWAV) Downstroke ratio Bio-inspired design Morphing-coupled flapping

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Efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates:A concise synthesis of difluoromethylene-containing 1,4-thiazine derivatives

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Chinese Chemical Letters 2024年第4期35卷 367-370页

作者： Zhiwei chen Heyun Sheng Xue Li Menghan chen Xin Li Qiuling song Institute of Next Generation Matter Transformation College of Materials Science&Engineering and College of Chemical Engineering at Huaqiao UniversityXiamen 361021China Fujian University Key Laboratory of Molecule Synthesis and Function Discovery College of ChemistryFuzhou UniversityFuzhou 350108China State Key Laboratory of Organometallic Chemistry and Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A practical method for the construction of difluoromethylene-containing 1,4-thiazine moieties using readily available diethyl bromodifluoromethanephosphonate(BrCF_(2)PO(OEt)_(2))as difluorocarbene precusor has been *** transformation features the efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates.A series of structurally novel and functionalized difluoromethylene-containing 1,4-thiazine derivatives were thus synthesized in good yields.

关键词： Difluoromethylene Pyridinium 1 4-zwitterionic thiolates 1 4-Thiazine derivatives

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Economic analysis of rooftop photovoltaics system under different shadowing conditions for 20 cities in China

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Building Simulation 2024年第2期17卷 235-252页

作者： Zhiyi Ren Yixing chen chengcheng song Mengyue Liu Anni XuQilin Zhang College of Civil Engineering Hunan UniversityChangsha410082China Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education Hunan UniversityChangsha410082China

Installing photovoltaic(PV)systems is an essential step for low-carbon *** economics of PV systems are strongly impacted by the electricity price and the shadowing effect from neighboring *** study evaluates the PV generation potential and economics of 20 cities in China under three shadowing ***,the building geometry models under three shadowing conditions for the 20 cities were constructed using ***,60 building models with PV systems and shadows from surrounding buildings were generated by City Buildings,Energy,and Sustainability(CityBES),an open platform,to simulate the PV power ***,the study presented one economic analysis model to evaluate the profitability by combining the market cost of rooftop PV systems and electricity prices in *** economic model included four indicators:payback period(static and dynamic),net present value(NPV),and internal rate of return(IRR).The results show that the reduction of PV power generation ranges from 8.29%to 16.01%under medium shadowing,and experiences a maximum decrease of up to 39.71%under high *** economic analysis shows that almost all the regions show reliable potential,obtaining an IRR higher than the reference value(5%).Nenjiang has the highest economic profit,with the highest NPV(86,181.15 RMB)and IRR(30.14%)under no shadowing among 20 *** also should be mentioned that the alignment between electricity price distribution and the solar power generation curve will directly impact the economic potential of PV systems.

关键词： rooftop photovoltaic system EnergyPlus economic analysis shadowing buildings electric price

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High-density lipoprotein regulates angiogenesis by affecting autophagy via miRNA-181a-5p

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Science China(Life Sciences) 2024年第2期67卷 286-300页

作者： Bi-Ang Kang Hua-ming Li Ya-Ting chen Meng-Jie Deng Yan Li Yue-ming Peng Jian-Jun Gao Zhi-Wei Mo Jia-Guo Zhou Zhi-Jun Ou Jing-song Ou Division of Cardiac Surgery Cardiovascular Diseases InstituteThe First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases Guangzhou 510080China NHC key Laboratory of Assisted Circulation(Sun Yat-sen University) Guangzhou 510080China Guangdong Provincial Engineering and Technology Center for Diagnosis and Treatment of Vascular Diseases Guangzhou 510080China Division of Vascular Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Department of Pharmacology Cardiac and Cerebral Vascular Research CenterZhongshan School of MedicineSun Yat-sen UniversityGuangzhou 510080China Division of Hypertension and Vascular Diseases Department of CardiologyCardiovascular Diseases InstituteThe First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Guangdong Provincial Key Laboratory of Brain Function and Disease Zhongshan School of MedicineSun Yat-sen UniversityGuangzhou 510080China

We previously demonstrated that normal high-density lipoprotein(nHDL)can promote angiogenesis,whereas HDL from patients with coronary artery disease(d HDL)is dysfunctional and impairs *** plays a critical role in angiogenesis,and HDL regulates ***,it is unclear whether n HDL and d HDL regulate angiogenesis by affecting *** cells(ECs)were treated with n HDL and d HDL with or without an autophagy ***,endothelial nitric oxide synthase(e NOS)expression,miRNA expression,nitric oxide(NO)production,superoxide anion(O2^(·-))generation,EC migration,and tube formation were evaluated.n HDL suppressed the expression of miR-181a-5p,which promotes autophagy and the expression of e NOS,resulting in NO production and the inhibition of O2^(·-)generation,and ultimately increasing in EC migration and tube formation.d HDL showed opposite effects compared to n HDL and ultimately inhibited EC migration and tube *** found that autophagy-related protein 5(ATG5)was a direct target of ***5 silencing or miR-181a-5p mimic inhibited n HDL-induced autophagy,e NOS expression,NO production,EC migration,tube formation,and enhanced O2^(·-)generation,whereas overexpression of ATG5 or miR-181a-5p inhibitor reversed the above effects of d ***5 expression and angiogenesis were decreased in the ischemic lower limbs of hypercholesterolemic low-density lipoprotein receptor null(LDLr^(-/-))mice when compared to C57BL/6 ***5 overexpression improved angiogenesis in ischemic hypercholesterolemic LDLr^(-/-)*** together,nHDL was able to stimulate autophagy by suppressing miR-181a-5p,subsequently increasing e NOS expression,which generated NO and promoted *** contrast,d HDL inhibited angiogenesis,at least partially,by increasing miR-181a-5p expression,which decreased autophagy and e NOS expression,resulting in a decrease in NO production and an increase in O2^(·-)*** findings reveal a nov

关键词： high-density lipoprotein angiogenesis autophagy ATG5 miRNA endothelial nitric oxide synthase

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