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Forced boiling of nonazeotropic immiscible mixture in a supercapillary microchannel array for ultra-high heat flux removal with chip junction temperature below 85℃

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Science China(Technological Sciences) 2024年第5期67卷 1364-1380页

作者： SUN Bo BAO YuChen TIAN Tong li ji School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Laboratory of Advanced Thermal Management Technologies School of Engineering ScienceUniversity of Chinese Academy of SciencesBeijing100049China

In this study,a structure-optimized two-phase microchannel heat sink with sintered submicron nucleation sites was developed and *** copper-based microchannels had a rectangular cross-section with an equivalent hydraulic diameter of 222μ*** subcooled flow boiling characteristics were comprehensively compared between pure HFE-7100 and a non-azeotropic,immiscible binary mixture of HFE-7100 and water,considering heating areas of 1 and 5 cm^(2).The total heating power input to the test section were 100–1500 and 250–3000 W for a 1 and 5 cm^(2)heat source,respectively,with a flow rate ranging from 50 to150 L/*** to pure HFE-7100,the non-azeotropic immiscible binary mixture of HFE-7100/water in the sintered porous microchannels exhibited a much higher overall heat transfer coefficient and lower power *** maintain the junction temperature of a high power electronic chip below 85℃,the proposed supercapillary microchannel heat sink could effectively dissipate the heat flux of 1275 W/cm^(2)over 1 cm^(2)heat source and 500 W/cm^(2)over 5 cm^(2)heat *** addition,the volume ratio of the binary mixture strongly influence the two-phase flow heat transfer *** optimal volume ratio exist in terms of the thermal resistance–pumping power minimization(HFE-7100:water=2:8 is recommended in this study).The findings of this investigation on the flow boiling properties of non-azeotropic immiscible mixtures help fill a gap in the related field.

关键词： microchannel sintered powder coating submicron nucleation cavities nonazeotropic immiscible ultra-high heat flux

Reactive oxygen species promote endurance exercise-induced adaptations in skeletal muscles

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Journal of Sport and Health Science 2024年第6期13卷 780-792页

作者： Scott K.Powers Zsolt Radak li li ji Malcolm Jackson Department of Applied Physiology University of FloridaGainesvilleFL 32608USA Research Institute of Sport Science Hungarian University of Sport ScienceBudapest 1123Hungary Department of Kinesiology University of MinnesotaSt.PaulMN 55455USA Department of Musculoskeletal and Ageing Science Institute of Life Course and Medical SciencesUniversity of LiverpoolLiverpool L78TXUK

The discovery that contracting skeletal muscle generates reactive oxygen species(ROS)was first reported over 40 years *** prevailing view in the 1980s was that exercise-induced ROS production promotes oxidation of proteins and lipids resulting in muscle ***,a paradigm shift occurred in the 1990s as growing research revealed that ROS are signaling molecules,capable of activating transcriptional activators/coactivators and promoting exercise-induced muscle *** evidence supports the notion that reduction-oxidation(redox)signaling pathways play an important role in the muscle remodeling that occurs in response to endurance exercise *** review examines the specific role that redox signaling plays in this endurance exercise-induced skeletal muscle *** begin with a discussion of the primary sites of ROS production in contracting muscle fibers followed by a summary of the antioxidant enzymes involved in the regulation of ROS levels in the *** then discuss which redox-sensitive signaling pathways promote endurance exercise-induced muscle adaptation and debate the strength of the evidence supporting the notion that redox signaling plays an essential role in muscle adaptation to endurance exercise *** hopes of stimulating future research,we highlight several important unanswered questions in this field.

关键词： Antioxidants Mitochondrial biogenesis Radicals Redox signaling

Microstructure and Internal Friction Behavior of Laser 3D Printed Fe-Based Amorphous Composites

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 196-204页

作者： Shuilong Huang Qingjun Chen li ji Kan Wang Guosheng Huang School of Material Science and Engineering Nanchang Hangkong UniversityNanchang330063China State Key Laboratory for Marine Corrosion and Protection Luoyang Ship Material Research Institute(LSMRI)Qingdao266237China

Laser 3D printing,also known as laser additive manufacturing(LAM),is favored for its ability to form bulk metallic glass(BMG)and its composite materials(BMGcs)with freeform *** this work,two different kinds of Fe_(41)Co_(7)Cr_(15)Mo_(14)C_(15)B_(6)Y_(2)amorphous coatings(A and B)were prepared by using LAM technology under air-and water-cooled conditions,respectively;meanwhile,to reduce the cracks generated due to the residual thermal stresses,coating C obtained by air-sweep annealing of B with a low energy-density *** morphology and amorphous content and microstructure of the coatings were investigated,the results show many cracks in coating B deposited under water-cooled conditions,and its microstructure shows an amorphous-crystal-nanocrystalline mixed *** was suppressed in coating C,obtained by air-sweep annealing based on coating B,but the amorphous content was reduced from 32.6 to 13.4%.And the hardness and corrosion resistance of the coating will increase with the increase in the amorphous ***,the internal friction behavior of a BMGcs was prepared on the basis of the process of sample C is compared with that of as-cast amorphous *** results show that the low temperature internal friction behavior of BMGcs is affected by the defects produced during printing,and the high temperature internal friction behavior is affected by the precipitated hard phase.

关键词： Laser 3D printing Amorphous coating Microstructure Corrosion resistance Internal friction behavior

Combined UAMP and MF Message Passing Algorithm for Multi-Target Wideband DOA Estimation with Dirichlet Process Prior

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Tsinghua Science and Technology 2024年第4期29卷 1069-1081页

作者： Shanwen Guan Xinhua Lu ji li Rushi Lan Xiaonan Luo Guangxi Key Laboratory of Image and Graphic Intelligent Processing Guilin University of Electronic TechnologyGuilin 541004China Guilin Huigu Institute of AI Industrial Technology Guilin 541004China School of Information Engineering Nanyang Institute of TechnologyNanyang 473000China

When estimating the direction of arrival (DOA) of wideband signals from multiple sources, the performance of sparse Bayesian methods is influenced by the frequency bands occupied by signals in different directions. This is particularly true when multiple signal frequency bands overlap. Message passing algorithms (MPA) with Dirichlet process (DP) prior can be employed in a sparse Bayesian learning (SBL) framework with high precision. However, existing methods suffer from either high complexity or low precision. To address this, we propose a low-complexity DOA estimation algorithm based on a factor graph. This approach introduces two strong constraints via a stretching transformation of the factor graph. The first constraint separates the observation from the DP prior, enabling the application of the unitary approximate message passing (UAMP) algorithm for simplified inference and mitigation of divergence issues. The second constraint compensates for the deviation in estimation angle caused by the grid mismatch problem. Compared to state-of-the-art algorithms, our proposed method offers higher estimation accuracy and lower complexity.

关键词： wideband direction of arrival(DOA)estimation sparse Bayesian learning(SBL) unitary approximate message passing(UAMP)algorithm Dirichlet process(DP)

Clinical study on the relationship between liver cirrhosis,ascites,and hyponatremia

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 751-758页

作者： Xuan-ji li Hui-Hui Meng Department of Gastroenterology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina Department of Hepatology Hubei Provincial Hospital of Traditional Chinese MedicineWuhan 430065Hubei ProvinceChina

BACKGROUND Cirrhosis is a common liver disease,and ascites is one of the common clinical ***,the clinical manifestations of ascites combined with hyponatremia as a high-risk condition and its relationship to patient prognosis have not been fully *** To explore the clinical manifestations,prognostic factors,and relationships of ascites with hyponatremia in patients with cirrhosis to provide better diagnostic and treatment *** In this study,we retrospectively analyzed the clinical data of 150 patients diagnosed with cirrhosis and ascites between 2017 and *** were divided into two groups:ascites combined with hyponatremia group and ascites *** compared the general characteristics,degree of hyponatremia,complications,treatment,and prognosis between the two *** In the study results,patients in the ascites combined with hyponatremia group showed an older average age(58.2±8.9 years),64.4%were male,and had a significantly longer hospitalization time(12.7±5.3 d).Hyponatremia was more severe in this group,with a mean serum sodium concentration of 128.5±4.3 mmol/L,which was significantly different from the ascites group of 137.6±2.1 mmol/*** with ascites and hyponatremia were more likely to develop hepatic encephalopathy(56.2%vs 39.0%),renal impairment(45.2%vs 28.6%)and infection(37.0%vs 23.4%).Regarding treatment,this group more frequently used diuretics(80.8%vs 62.3%)and salt supplements(60.3%vs 38.9%).Multiple logistic regression analysis identified older age[Odds ratio(OR)=1.06,P=0.025]and male gender(OR=1.72,P=0.020)as risk factors for hyponatremia combined with ***,patients with ascites and hyponatremia present a clear high-risk status,accompanied by severe complications and poor *** In patients with cirrhosis,ascites with hyponatremia is a high-risk condition that is often associated with severe complications.

关键词： liver cirrhosis Ascites Hyponatremia Risk Complications

Research progress on rolling superlubricity in solid lubricants

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Science China(Technological Sciences) 2024年第7期67卷 1980-1990页

作者： li PanPan li HongXuan ZHU DongXiang ZHU YongQi KANG FuYan WANG Wan ZHANG YaXin liU XiaoHong ji li ZHOU HuiDi CHEN jianMin State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Chemical Engineering Northwest Minzu UniversityLanzhou 730030China

Superlubricity is an ideal lubrication state where friction nearly vanishes between contact interfaces. It has become one of the most important research topics and approaches owing to its significance in reducing energy consumption and preventing device failures. As an efficient and universal lubricating principle capable of achieving superlubricity, rolling lubrication has attracted widespread attention in recent years. In this review, the theoretical concept of rolling lubrication and the experimental research progress of spherical/scroll structures are summarized. The review focuses on the possibility of achieving rolling lubrication using spherical/scroll structures(such as spherical fullerenes, carbon nanotubes, and formed and constructed spherical/scroll structures). The challenges in achieving rolling lubrication are summarized, and the possibility of molecular rolling lubrication,as well as its potential applications in superlubrication, are discussed.

关键词： spherical/scroll structure rolling lubrication superlubricity fullerene

Combining cisplatin and a STING agonist into one molecule for metalloimmunotherapy of cancer

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National Science Review 2024年第1期11卷 107-119页

作者： Shuren Zhang Dongfan Song Wenhao Yu ji li Xiaoyu Wang Yachao li Zihan Zhao Qi Xue jing Zhao jie P.li Zijian Guo State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringChemistry and Biomedicine Innovation Center (ChemBIC) Nanjing University Department of Urology Afflliated Drum Tower HospitalMedical SchoolNanjing University Nanchuang (jiangsu)Institute of Chemistry and Health

Mounting evidence suggests that strategies combining DNA-damaging agents and stimulator of interferon genes(STING) agonists are promising cancer therapeutic regimens because they can amplify STING activation and remodel the immunosuppressive tumor microenvironment. However, a single molecular entity comprising both agents has not yet been developed. Herein, we designed two PtIV-MSA-2 conjugates(Ⅰand Ⅱ) containing the DNA-damaging chemotherapeutic drug cisplatin and the innate immuneactivating STING agonist MSA-2; these conjugates showed great potential as multispecific small-molecule drugs against pancreatic cancer. Mechanistic studies revealed that conjugate Ⅰ upregulated the expression of transcripts associated with innate immunity and metabolism in cancer cells, significantly differing from cisplatin and MSA-2. An analysis of the tumor microenvironment demonstrated that conjugate I could enhance the infiltration of natural killer(NK) cells into tumors and promote the activation of T cells, NK cells and dendritic cells in tumor tissues. These findings indicated that conjugate I, which was created by incorporating a Pt chemotherapeutic drug and STING agonist into one molecule, is a promising and potent anticancer drug candidate, opening new avenues for small-molecule-based cancer metalloimmunotherapy.

关键词： platinum drug STING agonist single-molecule multitarget metalloimmunology

Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background

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Earth and Planetary Physics 2024年第1期8卷 119-132页

作者： Yingjie Zhang TianRan Sun JenniferACarter WenHao liu Steve Sembay ShuiNai Zhang li ji Chi Wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China College of Earth and Planetary Sciences The University of Chinese Academy of SciencesBeijing 100190China School of Physics and Astronomy The University of LeicesterLeicesterUK Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China

Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft ***,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray *** better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed *** two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral *** method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS *** method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind *** show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet *** the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted *** difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX *** addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the

关键词： solar wind charge exchange(SWCX) ROSAT All-Sky Survey(RASS) soft X-ray X-ray imaging magnetosphere

Lactonization of dyes promoted by a coordination cage facilitates cavity-induced chromism as ion mobile detector

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Science China Chemistry 2024年第5期67卷 1554-1560页

作者： liangliang Zhang Yu liang Zhifeng Xiao Yuxuan Meng jinyi Huang Xi lin ji li Hong-Cai Zhou Yu Fang Strait Institute of Flexible Electronics(SIFE Future Technologies)Fujian Normal University and Strait Laboratory of Flexible Electronics(SLoFE)Fuzhou 350017China State Key Laboratory of Chemo/Bio-Sensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Department of Chemistry Texas A&M UniversityCollege StationTexas 77842-3012USA State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Frontiers Science Center for Flexible Electronics(FSCFE) MIIT Key Laboratory of Flexible Electronics(KLoFE)Northwestern Polytechnical UniversityXi’an 710072China

Dye molecules often change colors(so-called “chromism”) according to the environment variation. However, they are rarely induced by a catalytic amount of cavity. Through encapsulation in the cavity of a porous coordination cage(PCC-2), Rhodamine B(1) is transformed from red quinonoid form(1q) into colorless lactone form(1l) in aprotic polar solutions. The μ4-OH groups in the cavity of PCC-2 are shown to stabilize the uncommon zwitterion intermediate(1z), followed by converting to 1l, thus accelerating the equilibrium. The chromism is catalyzed by 0.25 mol% of PCC-2, and the reaction rate is improved by 80,400times. 1@PCC-2 can be further fabricated to a sol-gel that exhibits ion recognition properties. The resulting encapsulation and stabilization of an unconventional intermediate by a catalytic amount of the coordination cage provides fundamental insights into molecular isomerization and has potential use in chemical sensing.

关键词： porous coordination cage Zwitterion intermediate cavity Rhodamine B chromism