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Preventing formation of intermetallic compounds in ultrasonic-assisted Sn soldering of Mg/Al alloys through pre-plating a Ni coating layer on the Mg substrate

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Journal of Magnesium and Alloys 2024年第2期12卷 726-741页

作者： Yingzong Liu Yuanxing Li Hui Chen Zongtao Zhu Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031PR China

Magnesium and aluminum alloys are widely used in various industries because of their excellent properties,and their reliable connection may increase application of *** compounds(IMCs)affect the joint performance of Mg/*** this study,AZ31 Mg alloy with/without a nickel(Ni)coating layer and 6061 Al alloy were joined by ultrasonic-assisted soldering with Sn-3.0Ag-0.5Cu(SAC)*** effects of the Ni coating layer on the microstructure and mechanical properties of Mg/Al joints were systematically *** Ni coating layer had a significant effect on formation of the Mg_(2)Sn IMC and the mechanical properties of Mg/Al *** blocky Mg_(2)Sn IMC formed in the Mg/SAC/Al joints without a Ni coating *** content of the Mg_(2)Sn IMC increased with increasing soldering temperature,but the joint strength *** joint without a Ni coating layer fractured at the blocky Mg_(2)Sn IMC in the solder,and the maximum shear strength was 32.2 *** pre-plating Ni on the Mg substrate,formation of the blocky Mg_(2)Sn IMC was inhibited in the soldering temperature range 240–280℃and the joint strength ***,when the soldering temperature increased to 310℃,the blocky Mg_(2)Sn IMC precipitated again in the *** electron microscopy showed that some nano-sized Mg_(2)Sn IMC and the(Cu,Ni)_(6)Sn_(5)phase formed in the Mg(Ni)/SAC/Al joint soldered at 280℃,indicating that the Ni coating layer could no longer prevent diffusion of Mg into the solder when the soldering temperature was higher than 280℃.The maximum shear strength of the Mg(Ni)/SAC/Al joint was 58.2 MPa for a soldering temperature of 280℃,which was 80.7%higher than that of the Mg/SAC/Al joint,and the joint was broken at the Mg(Ni)/SAC ***-plating Ni is a feasible way to inhibit formation of IMCs when joining dissimilar metals.

关键词： Ultrasonic-assisted soldering Mg_(2)Sn Ni coating layer Shear strength

High catalytic performance of neodymium modified Co_(3)O_(4) for toluene oxidation

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Journal of Rare Earths 2024年第1期42卷 94-101,I0004页

作者： Yanqiong Hu Luyue Zhang Jianbei Zhang Yongjun Liu School of Architecture and Environment Sichuan UniversityChengdu610065China National Engineering Research Center for Flue Gas Desulfurization Chengdu610065China

Co-based catalysts are the most promising catalysts in catalytic oxidation of volatile organic compounds(VOCs).Precious metal doping is adopted to improve the catalytic activity of toluene on Co_(3)O_(4) catalysts,but greatly increases its cost along with *** is found that doping a small amount of rare earth(Ce,Pr,Sm and Nd)can dramatically promote the catalytic activity of Co_(3)O_(4).Especially,the Nd-doped Co_(3)O_(4) catalyst exhibits excellent catalytic activity with a toluene removal rate of 90% at 162.1℃,which is even better than that of Pt-doped Co_(3)O_(4).Compared with other rare earth metal doping,the Nd doping leads to a higher ratio of Co^(3+)/Co^(2+) and has more oxygen *** in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments show that the lattice oxygen of Nd-Co sample can be utilized at a quite low temperature,while that of pure Co_(3)O_(4) cannot engage in oxidation reaction when the temperature is below 200℃,which visually demonstrates the main reason for the improved catalytic performance of Nd-Co catalyst.

关键词： Rare earth metals Nd Co_(3)O_(4) Toluene catalytic oxidation Oxygen vacancy Lattice oxygen

Aerodynamic Super-Repellent Surfaces

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Research 2024年第2期2023卷 115-122页

作者： Fanfei Yu Jinlong Yang Ran Tao Yao Tan Jinpei Wang Dehui Wang Longquan Chen Zuankai Wang Xu Deng Institute of Fundamental and Frontier sciences University of Electronic Science and Technology of ChinaChengdu 610054P.R.China Department of Mechanical Engineering City University of Hong KongKowloonHong Kong Special Administrative Region 999077P.R.China School of Physics.University of Electronic science and technology of China Chengdu 610054P.R.China Department of Mechanical Engineering Hong Kong Polytechnic UniversityKowloonHong Kong Special Administrative Region 999077P.R.China Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhen 518110P.R.China

Repelling liquid drops from engineering surfaces has attracted great attention in a variety of *** achieve efficient liquid shedding,delicate surface textures are often introduced to sustain air pockets at the liquid-solid ***,those surfaces are prone to suffer from mechanical failure,which may bring reliability issues and thus limits their ***,inspired by the aerodynamic Leidenfrost effect,we present that impacting drops are directionally repelled from smooth surfaces supplied with an exogenous air *** theoretical analysis reveals that the synchronized nonwetting and oblique bouncing behavior is attributed to the aerodynamic force arising from the air *** versatility and practicability of our approach allow for drop repellency without the aid of any surface wettability treatment and also avoid the consideration of mechanical stability issues,which thereby provides a promising candidate for the applications that necessitate liquid shedding,e.g.,resolve the problem of tiny raindrop adhesion on the automobile side window during driving.

关键词： thereby driving attributed

Significantly Enhanced Energy Storage Performances of PEI-based Composites Utilizing Surface Functionalized ZrO_(2) Nanoparticles for High-Temperature Application

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Chinese Journal of Polymer science 2024年第3期42卷 322-332,I0006页

作者： Qing-Qing Liu Qiu-Hao Lin Xiao-Dong Qi Nan Zhang Ting Huang Jing-Hui Yang Yong Wang School of Chemistry Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of Advanced Technologies of Materials Ministry of Education of ChinaSouthwest Jiaotong UniversityChengdu 610031China

Polymer dielectrics with a high energy density and an available energy storage capacity have been playing an important role in advanced electronics and power systems. Nevertheless, the use of polymer dielectrics in harsh environments is limited by their low energy density at high temperatures. Herein, zirconium dioxide(ZrO_(2)) nanoparticles were decorated with amino group utilizing 4,4-methylenebis(phenyl isocyanate)(AMEO) and successfully incorporated into polyetherimide(PEI) matrix. The dielectric properties, breakdown strength, and energy storage performances of PEI/ZrO_(2)-AMEO nanocomposites were investigated from 25 ℃ to 150 ℃. It is found that the combination of moderate bandgap ZrO_(2) with modest dielectric constant and polar groups at interface with deep trap can offer an available strategy to simultaneously increase the dielectric constant and breakdown strength of polymer dielectrics. As a result, the composites containing ZrO_(2)-AMEO exhibit excellent energy storage performance at elevated temperatures. Specially, the PEI-based composites with 3 vol% ZrO_(2)-AMEO display a maximum discharged energy density(U_(d)) of 3.1 J/cm^(3) at 150 ℃, presenting 90% higher than that of neat PEI. This study may help to better develop the polymer-based dielectric composite applied at elevated temperatures.

关键词： Polyetherimide High temperature dielectric ZrO_(2) Interface

High-throughput screening of single-atom catalysts confined in monolayer black phosphorus for efficient nitrogen reduction reaction

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Nano Research 2024年第4期17卷 2360-2367页

作者： Xiao-Yan Li Manyi Duan Pengfei Ou Department of Electrical and Computer Engineering University of TorontoTorontoOntario M5S 1A4Canada School of Physics and Electronic Engineering Sichuan Normal UniversityChengdu 610101China Department of Chemistry Northwestern UniversityEvanstonIL 60208USA

The discovery of metal-nitrogen centers as the active sites for electrolysis has aroused significant interest in utilizing single-atom catalysts for nitrogen reduction reaction(NRR).Properly designed nanostructured catalysts that strongly interact with nitrogen molecules(N_(2))can promote adsorption and activation,thereby resulting in efficient catalysts with high stability,activity,and *** this study,using density functional theory calculations,we selected monolayer black phosphorus(BP)as the substrate and screened a series of single-atom transition metals confined in tri-coordinated and tetra-coordinated active centers(without and with N dopants)to electro-catalyze *** a result,we have identified two promising candidates(Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4)),which exhibit not only low overpotentials of 0.56 and 0.49 V but also high thermodynamic and electrochemical stability,as well as good selectivity towards NRR over the competing hydrogen evolution *** also demonstrate the ability of Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4) to activate and hydrogenate N_(2) by donating electrons and regulating charge *** study not only predicts new BP-based promising catalysts but also provides guidance for the rational design of high-performance NRR electrocatalysts under ambient conditions.

关键词： N_(2) electroreduction reaction single-atom catalysts black phosphorus density functional theory high-throughput calculations

Cluster analysis reveals a homogeneous subgroup of PCOS women with metabolic disturbance associated with adverse reproductive outcomes

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Chinese Medical Journal 2024年第5期137卷 604-612页

作者： Hanxiao Chen Rujun Zeng Xun Zeng Lang Qin The Reproductive Medical Center Department of Obstetrics and GynecologyWest China Second University HospitalSichuan UniversityChengduSichuan 610041China Key Laboratory of Birth Defects and Related of Women and Children of Ministry of Education West China Second University HospitalSichuan UniversityChengduSichuan 610041China

Background:Polycystic ovarian syndrome(PCOS)is a heterogeneous and complex reproductive endocrinological disease that could lead to *** were many attempts to classify PCOS but it remains unclear whether there is a specific subgroup of PCOS that is associated with the best or worst reproductive outcomes of assisted reproductive techniques(ART).Methods:Infertile PCOS patients who underwent their first cycle of in vitro fertilization(IVF)in West China Second University Hospital,sichuan University from January 2019 to December 2021 were *** clinical and laboratory information of each individual were *** cluster analysis was *** ovarian stimulation parameters and reproductive outcomes were collected and compared between the different clusters of ***:Our analysis clustered women with PCOS into"reproductive","metabolic",and"balanced"clusters based on nine *** group was characterized by high levels of testosterone(T),sex hormone-binding globulin(SHBG),follicular stimulation hormone(FSH),luteinizing hormone(LH),and anti-Müllerian hormone(AMH).Metabolic group was characterized by high levels of body mass index(BMI),fasting insulin,and fasting *** group was characterized by low levels of the aforementioned reproductive and metabolic parameters,except for *** with PCOS patients in reproductive and balanced clusters,those in metabolic cluster had lower rates of good quality day 3 embryo and blastocyst ***,PCOS patients in the reproductive cluster had greater fresh embryo transfer(ET)cancelation rate and clinical pregnancy rate after fresh ET than metabolic cluster(odds ratio[OR]=3.37,95%confidence interval[CI]:1.77-6.44,and OR=6.19,95%CI:1.58-24.24,respectively).And compared with PCOS of metabolic cluster,PCOS of balanced cluster also had higher chance for fresh ET cancelation(OR=2.83,95%CI:1.26-6.35).Conclusion:Our study suggested that PCOS patients in met

关键词： Polycystic ovarian syndrome Assisted reproductive techniques Clustering analysis Metabolic disturbance Clinical pregnancy

Increased risk of subsequent primary lung cancer among female hormone-related cancer patients: A meta-analysis based on over four million cases

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中华医学杂志(英文版) 2024年第15期137卷 1790-1801页

作者： Wang Yan Song Wenpeng Wang Haoyu Zhu Guonian Li Yangqian Wang Zhoufeng Li Weimin Che Guowei Department of Thoracic Surgery West China Hospital Sichuan University Chengdu Sichuan China Lung Cancer Center West China Hospital Sichuan University Chengdu Sichuan China Department of Respiratory and Critical Care Medicine West China Hospital Sichuan University Chengdu Sichuan China Institute of Respiratory Health West China Hospital Sichuan University Chengdu Sichuan China Institute of Respiratory Health Frontiers Science Center for Disease-related Molecular Networks West China Hospital Sichuan University Chengdu Sichuan China

Background: The incidence rate of lung cancer in women has significantly increased over the past decade, and previous evidence has indicated a significant relationship between the elevated levels of sex hormones and the risk of lung cancer. Therefore, we hypothesized that female hormone-related cancer (FHRC) patients, including breast, endometrial, cervical, and ovarian cancer patients, may experience a higher risk of developing subsequent lung cancer. This meta-analysis aimed to identify the risk of lung cancer among FHRC patients compared to the general ***: The PubMed, Web of science, EMBASE, Cochrane Library, and CNKI databases were searched up to May 11, 2022. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were used to identify the risk of subsequent lung cancer after FHRC. Subgroup analyses based on the follow-up time and tumor type were also ***: A total of 58 retrospective cohort studies involving 4,360,723 FHRC participants were included. The pooled results demonstrated that FHRC patients had a significantly increased risk of developing subsequent primary lung cancer (SIR = 1.61, 95% CI: 1.48-1.76,P <0.001). Subgroup analysis revealed an obvious trend of increasing lung cancer risk over time (SIRs for <5 years, ≥5 years, ≥10 years, ≥20 years, and ≥30 years after FHRC: 1.32, 1.59, 1.57, 1.68, and 1.95, respectively). In addition, subgroup analysis stratified by tumor type indicated an increased risk of developing subsequent lung cancer after breast (SIR = 1.25,P <0.001), endometrial (SIR = 1.40,P = 0.019), cervical (SIR = 2.56,P <0.001), and ovarian cancer (SIR = 1.50,P = 0.010).Conclusion: FHRC patients are more likely to develop lung cancer than the general population. Furthermore, the increased risk of subsequent primary lung cancer is more obvious with a longer survival time and is observed in all types of hormone-related ***: International Platform of Registered Systematic Review and

关键词： Female hormone-related cancer Risk Subsequent primary lung cancer Meta-analysis

Regulating metal-acid double site balance on mesoporous SiO2-Al2O3 composite oxide for supercritical n-decane cracking

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Petroleum science 2024年第4期21卷 2881-2891页

作者： Liu-Ling Chen Jun Zhang Chun-Guang Li Li-Qun Fei Bo Wang Chen-Qi Zhang Yi Jiao Jian-Li Wang Institute of New Energy and Low-Carbon technology Sichuan University Engineering Research Center of Combustion and Cooling for Aerospace Power Ministry of Education School of Chemical Engineering Sichuan University State Key Laboratory of Industrial Vent Gas Reuse Southwest Institute of Chemical Co. Ltd science and technology on Scramjet Laboratory Beijing Power Machinery Research Institute

The balance between metal and acid sites directly affects the preparation of high-performance cracking catalysts with high heat sink and low ***,how to control acid-metal sites balance and its relationship with cracking performance are reported *** this work,a series of Pt/Al2O3-SiO2dual sites catalysts with different metal to acid active sites ratio(CM/CSA) were constructed by ethanolassisted impregnation method and the impact on n-decane cracking under supercritical conditions was systematically and deeply *** results showed that the conversion and carbon deposition increased gradually with varied CM/CSAand reached the balance at CM/CSAof *** proper ratio CM/CSA（0.13） can balance the deep dehydrogenation coking over metal active sites and high heat sink of cracking over acid active sites,the chemical heat sink reaches amazing 1.75 MJ/kg and carbon deposition is only22.03 mg/cm2at 750℃.Meanwhile,the few metal sites at low CM/CSAand the few strong acid sites at high CM/CSAare the main factors limiting the cracking *** CM/CSAlimit the activation of C-H bond and deep dehydrogenation of coking precursor,resulting in relative low cracking activity and carbon deposition,while high CM/CSAlimit the activation of C-C bond and increase the deep *** this contribution,design and construction of metal-acid dual sites can not only provide the technical solution for the preparation of high heat sink and low coking cracking catalyst,but also deepen the understanding of the cracking path of hydrocarbon fuel.

关键词： Metal-acid dual sites balance Catalytic cracking Hydrocarbon fuels Chemical heat sink Carbon deposition

Wafer-level substrate-free YIG single crystal film for a broadband tunable terahertz isolator

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Photonics Research 2024年第3期12卷 505-513页

作者： XILAI ZHANG DAN ZHAO DING ZHANG QIANG XUE FEI FAN YULONG LIAO QINGHUI YANG QIYE WEN School of Electronic science and Engineering State Key Laboratory of Electronic Thin Film and Integrated DevicesUniversity of Electronic Science and Technology of ChinaChengdu 610054China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network technology Institute of Modern OpticsNankai UniversityTianjin 300350China Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhen 518110China

Yttrium iron garnet(YIG)is a promising material for various terahertz applications due to its special optical *** present,a high-quality YIG wafer is the desire of terahertz communities and it is still challenging to prepare substrate-free YIG single crystal *** this work,we prepared wafer-level substrate-free La:YIG single crystal films,for the first time,to our *** optical and magneto-optical properties of La:YIG films were characterized by terahertz time domain spectroscopy(THz-TDS).Results show that the as-prepared La:YIG film has an insertion loss of less than 3 dB and a low absorption coefficient of less than10 cm-1below 1.6 *** from the thickness of the substrate-free YIG films and low insertion loss,their terahertz properties could be further manipulated by simply using a wafer-stacking *** four La:YIG films were stacked,there was an insertion loss of less than 10 dB in the range of 0.1-1.2 *** Faraday rotation angle of the four-layer-stacked La:YIG films reached 19°,and the isolation could reach17 *** further increasing the stacking number to eight pieces,a remarkable Faraday rotation angle of45°was achieved with an isolation of 23 dB,which is important for practical application in the THz *** material may provide a milestone opportunity to make various non-reciprocal devices,such as isolators and phase shifters.

关键词： YIG film insertion