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Improvement of mechanical properties and investigation of strengthening mechanisms on the Ti_(3)AlC_(2) ceramic with nanosized WC addition

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Journal of Advanced Ceramics 2024年第6期13卷 861-876页

作者： Yi Zhong Ying Liu Qinkai jiang Na jin Zifeng Lin jinwen Ye School of Materials Science&Engineering Sichuan UniversityChengdu 610065China Yibin R&D Park Yibin Industrial Technology Research InstituteSichuan UniversityYibin 644005China

Ti_(3)AlC_(2) (TAC) has great potential for use as an ablation material in aerospace applications due to its great oxidation/ablation resistance, but its high-temperature strength and thermal shock resistance still have much room for simultaneous improvement under fast temperature variation conditions. Herein, we used Ti_(3)AlC_(2) and WC powders as raw materials and successfully fabricated textured (Ti,W)_(3)AlC_(2) ceramic with small amounts of TiC and Al_(2)O_(3), and room temperature mechanical properties such as flexural strength (1146±46.9 MPa), fracture toughness (11.78±0.44 MPa·m^(1/2)), and hardness (5.81±0.11 GPa) at 5 wt% WC addition were achieved. The high-temperature strength of the ceramic was significantly improved, and better thermal shock resistance from 298 to 1173 K was simultaneously acquired together with the regulation of the elastic modulus, thermal conductivity, and thermal expansion coefficient, providing (Ti,W)_(3)AlC_(2) with more possibilities for fast-temperature variation applications. Strengthening and toughening mechanisms were proposed. Scanning transmission electron microscopy high-angle annular dark-field imaging (STEM-HADDF) showed that W randomly replaced the Ti1 and Ti2 sites of Ti_(3)AlC_(2), providing a good reference for establishing crystal models, and further density functional theory (DFT) calculations based on these models indicated a higher fracture energy of (Ti,W)_(3)AlC_(2) along different crystal planes, providing superior resistance to transgranular fracture;a lower mismatch degree of (Ti,W)_(3)AlC_(2)/Al_(2)O_(3) resulted in stronger interface bonding, resulting in greater resistance to intergranular fracture as well as more balanced stress distributions at different interfaces.

关键词： mechanical properties solid solution MAX phase transmission electron microscopy(TEM) ceramic atomic structure

The source of Double ITCZ induced by the SST bias over the tropical western Pacific as reflected in CAS-ESM2 Model

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Science China Earth Sciences 2024年第5期67卷 1604-1615页

作者： jinning TONG Fei ZHENG jiangbo jin Ruowen YANG jiang ZHU Qingcun ZENG Department of Atmospheric Sciences Yunnan UniversityKunming 650091China International Center for Climate and Environment Science Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

“Double ITCZ”is a common precipitation bias over the tropical Pacific in current climate models and Earth system models,but the reasons for its formation are still worth exploring and *** this study,we adopted the second version of Chinese Academy of Sciences Earth System Model(CAS-ESM2),by comparing a set of sea surface temperature(SST)bias correction experiments over the tropical Pacific,to explore the possible mechanism of SST bias on inducing the“Double ITCZ”from the perspective of the climatic annual mean bias in the coupled *** revealed that the simulated climatic annual mean SST bias over the tropical Pacific can affect the bias of latent heat flux through the saturation specific humidity,and the bias of latent heat flux can further affect that of vertical velocity of humid air by the condensation release mechanism,and finally modulate the simulated bias in ***,through the inter-comparison between different experiments,it is found that the source of Double ITCZ might mainly come from the annual mean SST bias over the tropical western Pacific through the proposed air-sea coupled process of“SST-saturated specific humidity-latent heat flux-vertical velocity-precipitation”,indicating a possible way on reducing the couple biases in models over the tropical Pacific to improve the accuracy of CAS-ESM2 for climate simulation.

关键词： SST bias Double ITCZ Nudging SST CAS-ESM2

In situ Simulation of Thermal Reality

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Research 2024年第2期2023卷 685-690页

作者： Peng jin jinrong Liu Fubao Yang Fabio Marchesoni Jian-Hua jiang Jiping Huang Department of Physics State Key Laboratory of Surface Physicsand Key Laboratory of Micro and Nano Photonic Structures(MOE)Fudan UniversityShanghai 200438China Center for Phononics and Thermal Energy Science Shanghai Key Laboratory of Special Artificial Microstructure Materials and TechnologySchool of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Physics University of CamerinoCamerino 62032Italy Suzhou Institute for Advanced Research University of Science and Technology of ChinaSuzhou 215123China

Simulated reality encompasses virtual,augmented,and mixed realities梕ach characterized by different degrees of truthfulness in the visual perception:"all false","coexistence of true and false,"and"difficult distinction between true and false,"*** all these technologies,however,the temperature rendering of virtual objects is still an unsolved ***,the lack of thermal tactile functions substantially reduces the quality of the user's real-experience *** address this challenge,we propose theoretically and realize experimentally a technological platform for the in situ simulation of thermal *** this purpose,we design a thermal metadevice consisting of a reconfigurable array of radiating units,capable of generating the thermal image of any virtual object,and thus rendering it in situ together with its thermal *** is a substantial technological advance,which opens up new possibilities for simulated reality and its applications to human activities.

关键词： false rendering signature

Implementation of gastrointestinal function protection in severe acute pancreatitis

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Hepatobiliary & Pancreatic Diseases International 2024年第5期23卷 521-522页

作者： Fu-Zheng Tao Rong-Lin jiang Shui-Fang jin Intensive Care Unit Taizhou Integrated Traditional Chinese and Western Medicine HospitalTaizhou 310075China Intensive Care Unit the First Affiliated Hospital of Zhejiang Chinese Medical University(Zhejiang Provincial Hospital of Chinese Medicine)Hangzhou 310006China

Severe acute pancreatitis(SAP)is a serious systemic disease associated with strong local inflammatory reactions and serious systemic pathophysiological disorders caused by trypsin *** with SAP are prone to exhibit gastrointestinal ***,gastrointestinal dysfunction further aggravates the systemic inflammatory response and metabolic abnormalities,resulting in a more critical condition of *** dysfunction is considered to be the“trigger”of multiple organ dysfunction syndrome[1].Thus,it is important to maintain gastrointestinal homeostasis in the treatment of SAP.

关键词： gastrointestinal pancreatitis acute

Bio-inspired Design and Inverse Kinematics Solution of an Omnidirectional Humanoid Robotic Arm with Geometric and Load Capacity Constraints

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Journal of Bionic Engineering 2024年第2期21卷 778-802页

作者： Zhichao Zhu Zirong Luo Yiming Zhu Tao jiang Minghai Xia Shanjun Chen Boyu jin College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina

Inspired by the driving muscles of the human arm,a 4-Degree of Freedom(DOF)concentrated driving humanoid robotic arm is proposed based on a spatial double parallel four-bar *** four-bar mechanism design reduces the inertia of the elbow-driving unit and the torque by 76.65%and 57.81%,*** the human pose regulation strategy that the human arm picks up a heavy object by adjusting its posture naturally without complicated control,the robotic arm features an integrated position-level closed-form inverse solution method considering both geometric and load capacity *** method consists of a geometric constraint model incorporating the arm angle(φ)and the Global Configuration(GC)to avoid joint limits and singularities,and a load capacity model to constrain the feasible domain of the arm ***,trajectory tracking simulations and experiments are conducted to validate the feasibility of the proposed inverse solution *** simulated maximum output torque,maximum output power and total energy consumption of the robotic arm are reduced by up to 2.0%,13.3%,and 33.3%,*** experimental results demonstrate that the robotic arm can bear heavy loads in a human-like posture,effectively reducing the maximum output torque and energy consumption of the robotic arm by 1.83%and 5.03%,respectively,while avoiding joints beyond geometric and load capacity *** proposed design provides a high payload–weight ratio and an efficient pose control solution for robotic arms,which can potentially broaden the application spectrum of humanoid robots.

关键词： Humanoid robotic arm Bio-inspired design Inverse kinematics solution Load capacity constraint Geometric constraint

On-Chip Micro Temperature Controllers Based on Freestanding Thermoelectric Nano Films for Low-Power Electronics

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Nano-Micro Letters 2024年第7期16卷 98-108页

作者： Qun jin Tianxiao Guo Nicolas Perez Nianjun Yang Xin jiang Kornelius Nielsch Heiko Reith Institute for Metallic Materials Leibniz Institute for Solid State and Materials Research01069 DresdenGermany Institute of Materials Engineering University of Siegen57076 SiegenGermany Institute of Applied Physics Technical University of Dresden01069 DresdenGermany Institute of Materials Science Technical University of Dresden01069 DresdenGermany

Multidimensional integration and multifunctional com-ponent assembly have been greatly explored in recent years to extend Moore’s Law of modern ***,this inevitably exac-erbates the inhomogeneity of temperature distribution in microsystems,making precise temperature control for electronic components extremely ***,we report an on-chip micro temperature controller including a pair of thermoelectric legs with a total area of 50×50μm^(2),which are fabricated from dense and flat freestanding Bi2Te3-based ther-moelectric nano films deposited on a newly developed nano graphene oxide membrane *** tunable equivalent thermal resistance is controlled by electrical currents to achieve energy-efficient temperature control for low-power electronics.A large cooling temperature difference of 44.5 K at 380 K is achieved with a power consumption of only 445μW,resulting in an ultrahigh temperature control capability over 100 K mW^(-1).Moreover,an ultra-fast cooling rate exceeding 2000 K s^(-1) and excellent reliability of up to 1 million cycles are *** proposed on-chip temperature controller is expected to enable further miniaturization and multifunctional integration on a single chip for microelectronics.

关键词： Temperature control Low-power electronics On-chip micro temperature controller Freestanding thermoelectric nano films Temperature-sensitive components

Sodium Leak Channel in Glutamatergic Neurons of the Lateral Parabrachial Nucleus Helps to Maintain Respiratory Frequency Under Sevoflurane Anesthesia

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Neuroscience Bulletin 2024年第8期40卷 1127-1140页

作者： Lin Wu Donghang Zhang Yujie Wu jin Liu jingyao jiang Cheng Zhou Department of Anesthesiology West China HospitalSichuan UniversityChengdu 610041China Laboratory of Anesthesia and Critical Care Medicine National-Local Joint Engineering Research Centre of Translational Medicine of AnesthesiologyWest China HospitalSichuan UniversityChengdu 610041China

The lateral parabrachial nucleus(PBL)is implicated in the regulation of respiratory *** leak channel(NALCN)mutations disrupt the respiratory rhythm and influence anesthetic sensitivity in both rodents and ***,we investigated whether the NALCN in PBL glutamatergic neurons maintains respiratory function under general *** results showed that chemogenetic activation of PBL glutamatergic neurons increased the respiratory frequency(RF)in mice;whereas chemogenetic inhibition suppressed *** knockdown in PBL glutamatergic neurons but not GABAergic neurons significantly reduced RF under physiological conditions and caused more respiratory suppression under sevoflurane *** knockdown in PBL glutamatergic neurons did not further exacerbate the respiratory suppression induced by propofol or *** sevoflurane anesthesia,painful stimuli rapidly increased the RF,which was not affected by NALCN knockdown in PBL glutamatergic *** study suggested that the NALCN is a key ion channel in PBL glutamatergic neurons that maintains respiratory frequency under volatile anesthetic sevoflurane but not intravenous anesthetic propofol.

关键词： Glutamatergic neurons Lateral parabrachial nucleus NALCN Respiration General anesthesia

Thermal safety boundary of lithium-ion battery at different state of charge

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Journal of Energy Chemistry 2024年第4期91卷 59-72页

作者： hang Wu Siqi Chen Yan Hong Chengshan Xu Yuejiu Zheng Changyong jin Kaixin Chen Yafei He Xuning Feng Xuezhe Wei Haifeng Dai Clean Energy Automotive Engineering Center Tongji UniversityShanghai 201804China College of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China

Thermal runaway(TR)is a critical issue hindering the large-scale application of lithium-ion batteries(LIBs).Understanding the thermal safety behavior of LIBs at the cell and module level under different state of charges(SOCs)has significant implications for reinforcing the thermal safety design of the lithium-ion battery *** study first investigates the thermal safety boundary(TSB)correspondence at the cells and modules level under the guidance of a newly proposed concept,safe electric quantity boundary(SEQB).A reasonable thermal runaway propagation(TRP)judgment indicator,peak heat transfer power(PHTP),is proposed to predict whether TRP ***,a validated 3D model is used to quantitatively clarify the TSB at different SOCs from the perspective of PHTP,TR trigger temperature,SOC,and the full cycle ***,three different TRP transfer modes are *** interconversion relationship of three different TRP modes is investigated from the perspective of *** paper explores the TSB of LIBs under different SOCs at both cell and module levels for the first time,which has great significance in guiding the thermal safety design of battery systems.

关键词： Lithium-ion battery Battery safety Thermal runaway State of charge Numerical analysis

Fe/S oxidation-coupled arsenic speciation transformation mediated by AMD enrichment culture under different pH conditions

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Journal of Environmental Sciences 2024年第3期137卷 681-700页

作者： Yu-hang Zhou Wei-xi Huang Zhen-yuan Nie Hong-chang Liu Yue Liu Can Wang jin-lan Xia Wen-sheng Shu Key Lab of Biometallurgy of Ministry of Education of China School of Minerals Processing and BioengineeringCentral South UniversityChangsha 410083China School of Life Sciences South China Normal UniversityGuangzhou 510631China

Arsenic(As)speciation transformation in acid mine drainage(AMD)is comprehensively affected by biological and abiotic factors,such as microbially mediated Fe/S redox reactions and changes in environmental conditions(pH and oxidation-reduction potential).However,their combined impacts on arsenic speciation transformation remain poorly ***,we explored arsenic transformation and immobilization during pyrite dissolution mediated by AMD enrichment culture under different acidic pH *** results for incubation and mineralogical transformation of solid residues show that in the presence of AMD enrichment culture,pH 2.0,2.5,and 3.0 are more conducive to the formation of jarosites and ferric arsenate,which could immobilize high quantities of dissolved arsenic by adsorption and *** pH conditions significantly affect the initial adsorption of microbial cells to the minerals and the evolution of microbial community structure,further infuencing the biodissolution of pyrite and the release and oxidation process of Fe/*** results of Fe/S/As speciation transformation of the solid residues show that the transformation of Fe,S,and As in solution is mainly regulated by pH and potential values,which imposed significantly different effects on the formation of secondary minerals and thus arsenic oxidation and *** above results indicated that arsenic transformation is closely related to the Fe/S oxidation associated with pyrite bio-oxidation,and this correlation is critically regulated by the pH conditions of the system.

关键词： Acid mine drainage(AMD) pH conditions Fe/S/As speciation transformation Microbial community structure