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Spatial construction of ultrasmall Pt-decorated 3D spinel oxidemodified N-doped graphene nanoarchitectures as high-efficiency methanol oxidation electrocatalysts

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Rare Metals 2024年第1期43卷 186-197页

作者： Qi Zhang Min-Min yan Wen-Fa Du Chen-Yu Yin Jian Zhang Lu yang Yun-qing Kang Hai-yan He Hua-Jie Huang College of Mechanics and Materials Hohai UniversityNanjing 210098China New Energy Technology Engineering Lab of Jiangsu Province College of ScienceNanjing University of Posts&Telecommunications(NUPT)Nanjing 210023China International Center for Materials Nanoarchitectonics(WPIMANA) National Institute for Materials ScienceTsukuba 305-0044IbarakiJapan

Direct methanol fuel cell technology recently becomes the focus of both academic and engineering circles,which stimulates the exploitation and utilization of advanced electrode catalysts with high activity and long ***,we demonstrate a robust bottom-up approach to the spatial construction of three-dimensional(3D) spinel manganese-cobalt oxide-modified N-doped graphene nanoarchitectures decorated with ultrasmall Pt nanoparticles(Pt/MnCo_(2)O_(4)-NG) via a controllable selfassembly *** incorporation of MnCo_(2)O_(4)nanocrystals provides abundant hydroxyl sources to promote the oxidative removal of CO-like byproducts on Pt sites,while the existence of 3D porous N-doped graphene networks facilitates the transportation of both ions and electrons in the hybrid system,thus giving rise to remarkable synergetic coupling effects during the methanol oxidation ***,the optimized Pt/MnCo_(2)O_(4)-NG nano architecture expres ses exceptional electrocatalytic properties with a large electrochemically active surface area of 99.5 m^(2)·g^(-1),a high mass activity of1508.3 mA·mg^(-1),strong toxicity resistance and reliable long-term durability,which have obvious competitive advantages over those of conventional Pt/carbon black,Pt/carbon nano tube,Pt/graphene,and Pt/N-doped graphene catalysts with the same Pt usage.

关键词： Platinum MnCo_(2)O_(4) 3D graphene Electrocatalysts Methanol oxidation

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Electronic control seed-metering system for precision seeding maize based on fuzzy PID

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 217-226页

作者： Xiaoshun Zhao Hongpeng Zhao Zehe Wang Jincai Li Huali Yu qing yan State Key Laboratory of North China Crop Improvement and Regulation Hebei Agricultural UniversityBaoding 071001HebeiChina College of Mechanical and Electrical Engineering Hebei Agricultural UniversityBaoding 071001HebeiChina

Aiming at the problem of poor uniformity of maize sowing caused by ground wheel slip,an electronic control seed-metering system(ECSMS)for maize single seed precision sowing was designed and a mathematical model for motor control of the ECSMS was *** PID parameters were set by Z-N method and fuzzy *** fuzzy PID control design and Simulink simulation were completed by MATLAB,which reduced response time of the system by 0.23 s and improved the control *** on the JPS-12 test bench show that the qualification index(QI)of maize seed-metering device with the ECSMS increases by 4.47%,the multiples index(MI)decreases by 1.96%,the miss index(MIX)decreases by 2.81%,and the coefficient of variation(CV)of qualified seed spacing decreases by 5.06%,and the sowing uniformity has been greatly *** results of the soil-tank test bench show that the system has good sowing uniformity and *** the QI is 96.74%,the MI is 2.15%,the MIX is 1.10%,and the CV of qualified seed spacing is 16.24%.Under different setting seed spacing and different sowing operation speed,the change range of seeding quality index was within 10%.The results of field sowing test show that the QI was 84.21%,the MI was 2.63%,the MIX was 7.89%,and the CV of qualified seed spacing was 22.15%,which meet the requirements of JB/T 10293-2013‘Specification for single seed planters(precision planters)’and the agronomic requirements for maize precision *** system runs stably and reliably in practical operation and has good operation performance.

关键词： maize seed-metering system electronic control precision sowing parameters tuning fuzzy PID control simulink simulation

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Study on the local time asymmetry of the Earth's ring currents based on multiple low-Earth-orbit satellite magnetic observations

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Science China Technological Sciences 2024年第11期67卷 3354-3364页

作者： OU JiaMing JIANG Yi yan qing State Key Laboratory of Lunar and Planetary Sciences Macau University of Science and Technology Zhuhai MUST Science and Technology Research Institute Macau University of Science and Technology Macau Institute of Space Technology and Application

The azimuthal morphology of Earth's ring currents has consistently shown asymmetry during extreme space weather events at low latitudes, particularly during geomagnetic storms. A dawn-dusk pattern has been detected during the storm main phase through near-Earth and in-situ magnetic measurements. This asymmetry is believed to arise from asymmetric solar windmagnetosphere coupling and is linked to the closure of the ring current. Recent evidence has confirmed the existence of asymmetric ring currents during quiet times and the storm recovery phase. This phenomenon may be closely related to the evolution of ring currents, including plasma injection and decay processes. In this study, the local time asymmetry of the ring current is estimated using data from low-Earth-orbit Swarm and Macao Science Satellite-1(MSS-1) missions. Spherical harmonics models are developed to quantify the magnetic field of ring currents through external Gauss coefficients during both quiet periods and the storm recovery phase. Several features of dawn-dusk asymmetry are observed in various cases in different months.(1) The maximum difference in magnetic value across local time ranges from 3 to 10 nT, showing relative invariance compared with various Sym-H levels.(2) Stronger magnetic signals are detected at the premidnight sector during quiet times and at the afternoon sector during the storm recovery phase.(3) Magnetic perturbations remain at a lower level during the postmidnight and morning sectors. Although the pattern of local time asymmetry differs between quiet times and the recovery phase,dawn-dusk asymmetry remains the most pronounced feature, affecting the trapping and loss of charged particles in the inner magnetosphere. Combining Swarm and MSS-1 magnetic observations can enable convenient monitoring of the detailed azimuthal local time effects of the ring current at various disturbance levels in the future.

关键词： Earth’s ring currents local time asymmetry, SHA model Macao Science Satellite-1

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Comprehensive evaluations of heat transfer performance with conjugate heat dissipation effect in high-speed rotating free-disk modeling of aero-engines

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Fundamental Research 2024年第3期4卷 611-623页

作者： Aqiang Lin Gaowen Liu Ran Chang yan Chen qing Feng School of Power and Energy Northwestern Polytechnical UniversityXi'an 710129China Shaanxi Key Laboratory of Thermal Science in Aero-engine System Northwestern Polytechnical UniversityXi'an 710072China Research&Development Institute of Northwester

Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in *** study aims to investigate the complex heat transfer mechanisms of a rotating turbine disk under high-speed conditions.A high-speed rotating free-disk model with Dorfman empirical solutions is developed to evaluate the heat transfer performance considering various ***,the influence of compressibility,variable properties,and heat dissipation is determined using theoretical and numerical *** particular,a novel combined solution method is proposed to simplify the complex heat transfer *** results indicate that the heat transfer performance of a free disk is primarily influenced by the rotating Mach number,rotating Reynolds number,Rossby number,and wall temperature *** heat transfer temperature and Nusselt number of the free disk are strongly correlated with the rotating Mach number and rotating Reynolds *** reveals that heat dissipation is a critical factor affecting the accurate evaluation of the heat transfer performance of the turbine ***,the combined solution method can serve as a reference for future investigations of flow and heat transfer in high-speed rotating turbine disk cavity systems in aero-engines.

关键词： Aero-engine Rotating turbine disk Dimensional analysis Compressibility Heat dissipation Dorfman empirical solution

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Silurian integrative stratigraphy,biotas,and paleogeographical evolution of the qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth Sciences 2024年第4期67卷 1005-1035页

作者： Zhongyang CHEN qing CHEN Guangxu WANG Xiang FANG Peng TANG Guanzhou yan Wenwei YUAN Bing HUANG Xiaole ZHANG Kui yan Yuandong ZHANG Yi WANG State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China

The Silurian palaeontology and stratigraphy of the qinghai-Tibetan Plateau have been studied for more than100 *** the launch of the Second Tibetan Plateau Scientific Expedition and Research,it is necessary to update the summaries of the Silurian stratigraphy and fossil assemblages of the qinghai-Tibetan Plateau and their correlation with its surrounding *** this study,we have selected 33 sections from the qinghai-Tibetan Plateau and its surroundings areas,summarised the available data in terms of stratigraphic regionalisation,lithostratigraphy,chronostratigraphy,and biostratigraphy,and divided the study area into four stratigraphic provinces:the Xizang-Western Yunnan-Western Sichuan Province,the KunlunQilian Province,the South China Province,and the Tarim *** general,the Silurian strata in the qinghai-Tibetan Plateau is more complete than those in other areas of *** studies of the vertebrate faunas,sporomorph assemblages,and brachiopod faunas of the study area indicate a closer geographical relationship between the South China,Tarim,and Indochina palaeoplates,than previously *** with the surrounding areas where Silurian strata have been extensively studied,the study of Silurian strata in the main part of the qinghai-Tibetan Plateau is still in the preliminary *** the future,it is necessary to conduct research on the age,distribution,and resource potential of basal Silurian black shales to provide new directions for shale gas exploration and development in *** shallow marine strata of the middle to upper Silurian require further *** that the Silurian System in the qinghai-Tibetan Plateau is more complete,it has the potential to supplement and improve the study of the carbon isotope stratigraphy of the Silurian in China.

关键词： qinghai-Tibetan Plateau Silurian Stratigraphic regionalisation Lithostratigraphy Biostratigraphy Palaeogeographical evolution

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Solitons and Their Biperiodic Pulsation in Ultrafast Fiber Lasers Based on CB/GO

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Chinese Physics Letters 2024年第8期41卷 28-32页

作者： Zhen-Tao Ju Zhi-Zeng Si Xin yan Chao-qing Dai College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityLin’an 311300China

The carbon black(CB)is introduced to manufacture CB/graphene oxide(GO)composite material to mitigate limitations of GO as a saturable absorber with the excellent performance in ultrafast fiber *** a central wavelength of 1555.5 nm,the stable mode-locked pulse with width of 656 fs,repetition rate of 20.16 MHz,and high signal-to-noise ratio of 82.07 dB is experimentally ***,experimental observations for pulsation phenomena of vector biperiodic solitons combining period-1 and period-17,period-2 and period-32,period-3 and period-36 are verified via simulations.

关键词： fiber periodic absorber

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Improvement of impact properties of Al-Si-Mg alloy via solution treatment and joint modification with Sr and La

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Rare Metals 2024年第7期43卷 3301-3313页

作者： Xiong-Ling Zheng Shao-Xiang Li Jia-Le Ma qing-yan Xu Hai-Dong Zhao Zhi-Qiang Han Key Laboratory for Advanced Materials Processing Technology Ministry of EducationSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China National Engineering Research Center of Near-Net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

An effort to obtain superior impact properties for Al-7Si-0.35 Mg alloy is presented,where modification with 0.02 wt% Sr and 0.1 wt% La as well as solution treatment was jointly *** samples were solution treated at 535℃ for 15 min to 12 *** microstructure,fracture mechanism,and their correlation with the impact properties of the alloy were studied in detail mainly through optical microscopy(OM),scanning electron microscopy(SEM) and oscillography impact *** results show that the addition of Sr and La refined the eutectic Si particles significantly from~ 2.05 μm(modified with Sr alone) to~ 0.75 μm in as-cast microstructure,leading to a very homogeneous distribution of spheroidized Si particles in the alloy solution treated at 535℃ for 8 *** alloy exhibits excellent impact toughness up to 75 J·cm^(-2),which is much higher than the maximum impact toughness of the alloys modified by Sr alone(~ 46 J·cm^(-2)).The major reason for this remarkable increase in the impact property is the dramatic increase in crack initiation *** dispersoid-free zones(DFZs)near the eutectic regions mainly consist of the ductile Al-matrix,which exhibits excellent *** ductile Al-matrix of the DFZs hinders the crack propagation,resulting in a significant increase in crack propagation energy.

关键词： Aluminum alloys Modification Solution treatment Microstructure Impact properties Fracture mechanism

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Single thiolate replacement of metal nanoclusters

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Science China Chemistry 2024年第2期67卷 523-528页

作者： Ambreen Ambreen Yue Zhou Wanmiao Gu qing You Liang Fang Guoqing Bian Nan yan Nan Xia Zhikun Wu Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyInstitute of Solid State PhysicsHefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesHefei230031China University of Science and Technology of China Hefei230601China Institute of Physical Science and Information Technology Anhui UniversityHefei230601China

Surface thiolates play important roles in evincing the structures and properties of thiolated metal nanoclusters—one type of recently emerging inorganic-organic hybrids,and thus the thiolate substitution,especially single thiolate substitution,is highly desirable for subtly tailoring the structures and properties of metal ***,such a single-thiolate substituting is challenging,and its influence on the metal-metal and metal-sulfur bonds remains mysterious due to the absence of the singlethiolate-substituted ***,we developed a combined method,concurrently synthesized the single-thiolate-substituted nanocluster and its parent nanocluster,and successfully resolved their structures by single crystal X-ray crystallography,which reveals that the single thiolate substitute has an obvious influence on the metal-metal and metal-sulfur bond lengths although it has no effect on the absorption ***,the metal-metal and metal-sulfur bonds show various thermal extensibility and even the negative thermal expansion phenomena of the Au–S bond were observed in the single-thiolate-substituted *** bond length-related stability was also ***,this study highlights a novel synthesis method and offers novel structural insights and an in-depth structure-property correlation of thiolated metal nanoclusters.

关键词： metal nanoclusters single thiolate replacement thermal expansion stability intercluster interaction

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Potassium and calcium channels in different nerve cells act as therapeutic targets in neurological disorders

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Neural Regeneration Research 2025年第5期20卷 1258-1276页

作者： qing Qiu Mengting yang Danfeng gong Haiying Liang Tingting Chen Department of Pharmacology School of PharmacyNantong UniversityNantongJiangsu ProvinceChina Jiangsu Province Key Laboratory of Inflammation and Molecular Drug Target NantongJiangsu ProvinceChina Department of Pharmacy Longyan First Affiliated Hospital of Fujian Medical UniversityLongyanFujian ProvinceChina

The central nervous system, information integration center of the body, is mainly composed of neurons and glial cells. The neuron is one of the most basic and important structural and functional units of the central nervous system, with sensory stimulation and excitation conduction functions. Astrocytes and microglia belong to the glial cell family, which is the main source of cytokines and represents the main defense system of the central nervous system. Nerve cells undergo neurotransmission or gliotransmission, which regulates neuronal activity via the ion channels, receptors, or transporters expressed on nerve cell membranes. Ion channels, composed of large transmembrane proteins, play crucial roles in maintaining nerve cell homeostasis. These channels are also important for control of the membrane potential and in the secretion of neurotransmitters. A variety of cellular functions and life activities, including functional regulation of the central nervous system, the generation and conduction of nerve excitation, the occurrence of receptor potential, heart pulsation, smooth muscle peristalsis, skeletal muscle contraction, and hormone secretion, are closely related to ion channels associated with passive transmembrane transport. Two types of ion channels in the central nervous system, potassium channels and calcium channels, are closely related to various neurological disorders, including Alzheimer's disease, Parkinson's disease, and epilepsy. Accordingly, various drugs that can affect these ion channels have been explored deeply to provide new directions for the treatment of these neurological disorders. In this review, we focus on the functions of potassium and calcium ion channels in different nerve cells and their involvement in neurological disorders such as Parkinson's disease, Alzheimer's disease, depression, epilepsy, autism, and rare disorders. We also describe several clinical drugs that target potassium or calcium channels in nerve cells and could be u

关键词： astrocytes calcium channels central nervous system extracellular ion concentration microglia neurological disorders neurons potassium channels

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Circ_0004592:An auxiliary diagnostic biomarker for gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2757-2768页

作者： Shan Kong yan-Hua Xu Ming Zheng Shao-qing Ju Heng-Chuan Shi Department of Laboratory Medicine Jiangsu Province Official HospitalNanjing 210000Jiangsu ProvinceChina Department of Laboratory Medicine Northern Jiangsu People’s HospitalYangzhou 225000Jiangsu ProvinceChina Department of Laboratory Medicine The Affiliated Hospital of Nantong UniversityNantong 226001Jiangsu ProvinceChina

BACKGROUND Gastric cancer(GC)has a high mortality rate,and robust diagnostic biomarkers are currently ***,the clinical relevance of circular RNAs(circRNAs)as GC biomarkers remains largely *** To evaluate the potential of novel circRNA circ_0004592 in the early screening and prognosis of *** High-throughput sequencing of circRNAs was performed to screen for potential target ***_0004592 expression was examined in GC tissues,cells,and *** samples were collected from healthy subjects’patients,as well as from patients with benign lesions,precancerous lesions,and GC,whereafter the diagnostic accuracy of circ_0004592 was *** correlation between circ_0004592 levels in plasma and clinicopathological data of patients with GC was further *** Circ_0004592 was upregulated in both the tissue and plasma of patients with ***,circ_0004592 expression was higher in patients with precancerous lesions than in healthy controls while being highest in patients with *** the same patient,the postoperative plasma level of circ_0004592 was lower than that in the preoperative ***,circ_0004592 level was significantly correlated with tumor differentiation,tumor depth,and lymph node *** area under the curve(AUC)of plasma circ_0004592 exhibited high sensitivity and specificity for differentiating patients with GC from healthy *** based on circ_0004592,carcinoembryonic antigen,and cancer antigen 199 achieved a superior AUC and was highly *** Plasma circ_0004592 may represent a potential non-invasive auxiliary diagnostic biomarker for patients with GC.

关键词： Biomarker Circular RNA Diagnosis Gastric cancer Plasma

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