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Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

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China Foundry 2024年第3期21卷 248-256页

作者： Gui-quan Wang Zhuo Xu Zhong-li Liu xiang Chen Yan-xiang Li School of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake discs.In this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical properties.Compacted graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of ferrite.The peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction tests.The morphology of thermal cracks and 3D profiles of the worn surfaces were also discussed.It is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue resistance.Oxidization of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal cracks.Despite the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

关键词： compacted graphite iron brake disc thermomechanical properties thermal fatigue wear

Miniaturized power detection module operating in millimeter wave band

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Journal of Electronic Science and Technology 2024年第2期22卷 69-76页

作者： xiang Zhou Zhi-yong Zhong School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

The miniaturized broadband detection module can be embedded into the microwave application system such as the front end of the transmitter to detect the power or other parameters in real time.It is highly prospective in military and scientific research.In this paper,a broadband power detection module operating at 26.5 GHz-40.0 GHz is designed by using low-barrier Schottky diode as the detector and a comparator for threshold output.This module can dynamically detect the power range between-10 dBm and 10 dBm with the detection accuracy of 0.1 dB.Further,the temperature compensation circuit is also applied to improve the measurement error.As a result,the resulted error low to±1 dB in the temperature range of -55℃ to +85℃ is achieved.The designed module is encapsulated by a Kovar alloy with a small volume of 9 mm×6 mm×3 mm.This endows the designed module the advantages of small size,easy integration,and low cost,and even it is applicable to high-reliability environments such as satellites.

关键词： Diode Miniaturization Power detection Temperature compensation

The interaction effect of grip strength and lung function (especially FVC) on cardiovascular diseases: a prospective cohort study in Jiangsu Province, China

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Journal of Geriatric Cardiology 2022年第9期19卷 651-659页

作者： Jia-Li LIU Jia-Qi WANG Dan WANG Yu QIN yong-Qing ZHANG quan-yong xiang School of Public Health Southeast UniversityNanjingJiangsu ProvinceChina Department of Chronic Non-com-municable Disease Control Jiangsu Province Center for Disease Control and PreventionNanjingJiangsu ProvinceChina

OBJECTIVE Lung function and grip strength(GS)are associated with cardiovascular disease(CVD),but whether these risk factors interact to affect CVD is unknown.This study aimed to explore the interactions between lung function and GS with major CVD(defined as fatal/non-fatal myocardial infarction,stroke,and heart failure)incidence.METHODS We conducted a prospective cohort study on the Chinese population in Jiangsu Province.Cox proportional haz-ards models were used to explore the associations between GS,lung function,and major CVD incidence.RESULTS A total of 5967 participants were included in our study;among them,182 participants developed major CVD.Parti-cipants with low forced vital capacity(FVC)had a higher risk of major CVD(hazard ratio(HR)=1.45;95%confidence interval(CI):1.05-2.01;P<0.05)compared with normal FVC.The risk of major CVD incidence(HR=0.54;95%CI:0.35-0.83;P<0.01)was significantly lower in participants with high GS than in individuals with low GS.The interaction between FVC and GS for major CVD incidence(P=0.006)was statistically significant.Compared with normal FVC participants with high GS,low FVC parti-cipants with low GS had the highest risk of major CVD incidence(HR=2.50;95%CI:1.43-4.36;P<0.01).CONCLUSION Among people with low FVC,the risk of major CVD is lower with high GS.Participants with low FVC and low GS have the highest risk of major CVD.Therefore,more attention should be paid to the incidence of major CVD in individu-als with low FVC,especially those who have lower GS.

关键词： function strength interaction

Subnatural-linewidth fluorescent single photons

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Photonics Research 2024年第4期12卷 625-637页

作者： HE-BIN ZHANG GAO-xiang LI yong-CHUN LIU State Key Laboratory of Low-Dimensional quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Department of Physics Huazhong Normal UniversityWuhan 430079China Frontier Science Center for quantum Information Beijing 100084China

Subnatural-linewidth single photons are of vital importance in quantum optics and quantum information science.According to previous research, it appears difficult to utilize resonance fluorescence to generate single photons with subnatural linewidth. Here we propose a universally applicable approach to generate fluorescent single photons with subnatural linewidth, which can be implemented based on Λ-shape and similar energy structures.Further, the general condition to obtain fluorescent single photons with subnatural linewidth is revealed.The single-photon linewidth can be easily manipulated over a broad range by external fields, which can be several orders of magnitude smaller than the natural linewidth. Our study can be easily implemented in various physical platforms with current experimental techniques and will significantly facilitate the research on the quantum nature of resonance fluorescence and the technologies in quantum information science.

关键词： quantum utilize optics

Iron–doped bismuth oxybromides as visible-light-responsive Fenton catalysts for the degradation of atrazine in aqueous phases

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Journal of Environmental Sciences 2024年第3期137卷 321-332页

作者： yong-Li Cai Yu-Hang Xu Ji-Zun xiang Zhi-Qiang Zhang Qiu-xiang He Ya-Feng Li Jian Lü Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation College of Resources and EnvironmentFujian Agriculture and Forestry UniversityFuzhou 350002China State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou UniversityFuzhou 350116China

Pesticides and its degradation products,being well–known residues in soil,have recently been detected in many water bodies as pollutants of emerging concerns,and thus there is a contemporary demand to develop viable and cost–effective techniques for the removal of related organic pollutants in aqueous phases.Herein,a visible-light-responsive Fenton system was constructed with iron–doped bismuth oxybromides(Fe–BiOBr)as the catalysts.Taking the advantage of sustainable Fe(Ⅲ)/Fe(Ⅱ)conversion and optimized H_(2)O_(2)utilization,the optimal Fe–BiOBr–2 catalyst showed an excellent atrazine removal efficiency of 97.61%in 120 min,which is superior than the traditional homogeneous Fenton and the majority of heterogeneous processes documented in the literature.In this photo–Fenton system,hydroxyl(·OH)and superoxide(·O_(2)^(-))radicals were dominant active species contributed to the oxidative degradation of atrazine.Due to the production of various active radicals,five degradation pathways were proposed based on the identification of intermediates and degradation products.Overall,this work not only demonstrates a fundamental insight into creating highly efficient and atom economic photo-Fenton systems,but also provides a complementary strategy for the treatment of organic pollutants in water.

关键词： Bismuth oxybromide Photo–Fenton Atrazine Catalytic degradation

Preparation and performance evaluation of the slickwater using novel polymeric drag reducing agent with high temperature and shear resistance ability

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Petroleum Science 2024年第2期21卷 1113-1121页

作者： Ming-Wei Zhao Zhen-Feng Ma Cai-Li Dai WeiWu yong-quan Sun Xu-Guang Song Yun-Long Cheng xiang-Yu Wang National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580ShandongChina Shandong Key Laboratory of Oilfield Chemistry China University of Petroleum(East China)Qingdao266580ShandongChina Sinopec Shengli Oilfield Dongying257001ShandongChina Department of Chemical and Materials Engineering University of AlbertaEdmontonAB T6G 1H9Canada East China Petroleum Bureau of Sinopec Nanjing210011JiangsuChina

Slickwater fracturing fluids are widely used in the development of unconventional oil and gas resources due to the advantages of low cost,low formation damage and high drag reduction performance.However,their performance is severely affected at high temperatures.Drag reducing agent is the key to determine the drag reducing performance of slickwater.In this work,in order to further improve the temperature resistance of slickwater,a temperature-resistant polymeric drag reducing agent(PDRA)was synthesized and used as the basis for preparing the temperature-resistant slickwater.The slickwater system was prepared with the compositions of 0.2 wt%PDRA,0.05 wt%drainage aid nonylphenol polyoxyethylene ether phosphate(NPEP)and 0.5 wt%anti-expansion agent polyepichlorohydrindimethylamine(PDM).The drag reduction ability,rheology properties,temperature and shear resistance ability,and core damage property of slickwater were systematically studied and evaluated.In contrast to on-site drag reducing agent(DRA)and HPAM,the temperature-resistant slickwater demonstrates enhanced drag reduction efficacy at 90℃,exhibiting superior temperature and shear resistance ability.Notably,the drag reduction retention rate for the slickwater achieved an impressive 90.52%after a 30-min shearing period.Additionally,the core damage is only 5.53%.We expect that this study can broaden the application of slickwater in high-temperature reservoirs and provide a theoretical basis for field applications.

关键词： Unconventional resources Polymeric drag reducing agent Slickwater High drag reduction rate Temperature resistance

Engineering the Interface Between Au Nanoparticles and CoO-Ov to Enhance the Catalytic Performance of 5-Hydroxymethylfurfural(HMF)to 2,5-Dimethylfuran(DMF)

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Chemical Research in Chinese Universities 2024年第1期40卷 47-54页

作者： xiang Shuang GUO yong LIU Xiaohui WANG Yanqin Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterResearch Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237P.R.China

The interface between Au and support has attracted extensive interest because of its unique catalytic ability for hydrogen activation in catalytic hydrogenation/hydrogenolysis reactions.Herein,we create the Au-CoO-OV interface in the 1.0%Au/Co3O4-Rod-250 catalyst,which could dissociate H2 via the heterolytic way to yield rich hydride species and achieve excellent catalytic performance in the hydrogenolysis of biomass-derived 5-hydroxymethylfurfural(HMF)to 2,5-dimethylfuran(DMF).The XRD and HRTEM analyses show that Au nanoparticles are uniformly dispersed on CoO-OV surface and in situ DRIFTS spectra show the enhancement of heterolytic dissociation of hydrogen(signals of Au-D and O-D vibration)compared with bare CoO(Co3O4-Rod-250).This work provides insights for fabricating highly active Au-support catalysts for catalytic hydrogenation/hydrogenolysis reactions.

关键词： Au-CoO-OV interface Hydride species Heterolytic dissociation 5-Hydroxymethylfurfural(HMF) 2 5-Dimethylfuran(DMF)

Airgap-harmonic-oriented Partitioned Design Method of PMV Motor with Improved Torque Performances

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 43-50页

作者： Zhaopeng Wu Li quan Zixuan xiang Deyang Fan Tengguang Wang Xiaoyong Zhu the School of Electrical and Information Engineering Jiangsu UniversityZhenjiang 212013China IEEE

Here,we introduce a partitioned design method that is oriented toward airgap harmonic for permanent magnet vernier(PMV)motors.The method proposes the utilization of airgap flux harmonics as an effective bridge between the torque design region and the torque performances.To illustrate the efficacy of this method,a partitioned design PMV motor is presented and compared with the initial design.Firstly,the torque design region of the rotor is artfully divided into the torque enhancement region and ripple reduction region.Meanwhile,the main harmonics that generate output torque are chosen and enhanced,optimization.Moreover,the harmonics that generate torque ripple are selected and reduced based on torque harmonics optimization.Finally,the functions of the partitioned PMV motor torque are assessed based on the finite element method.By the purposeful design of these two regions,the output torque is strengthened while torque ripple is inhibited effectively,verifying the effectiveness and reasonability of the proposed design method.

关键词： Permanent magnet vernier(PMV)motor Airgap flux harmonic Partitioned design Low torque ripple

Clinical features and prognostic factors of duodenal neuroendocrine tumours:A comparative study of ampullary and nonampullary regions

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 907-918页

作者： Sa Fang Yu-Peng Shi Lu Wang Shuang Han yong-quan Shi Department of Gastroenterology Honghui HospitalXi’an Jiaotong UniversityXi'an 710054Shanxi ProvinceChina Department of Gastroenterology The Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710032Shaanxi ProvinceChina Department of Gastroenterology Xijing Hospital Affiliated to Air Force Medical UniversityXi'an 710032Shaanxi ProvinceChina

BACKGROUND Duodenal neuroendocrine tumours(DNETs)are rare neoplasms.However,the incidence of DNETs has been increasing in recent years,especially as an incidental finding during endoscopic studies.Regrettably,there is no consensus regarding the ideal treatment of DNETs.Even there are few studies on the clinical features and survival analysis of DNETs.AIM To analyze the clinical characteristics and prognostic factors of patients with duodenal neuroendocrine tumours.METHODS The clinical data of DNETs diagnosed in the First Affiliated Hospital of Air Force Military Medical University from June 2011 to July 2022 were collected.Neuroen-docrine tumours located in the ampulla area of the duodenum were divided into the ampullary region group;neuroendocrine tumours in any part of the duo-denum outside the ampullary area were divided into the nonampullary region group.Using a retrospective study,the clinical characteristics of the two groups and risk factors affecting the survival of DNET patients were analysed.RESULTS Twenty-nine DNET patients were screened.The male to female ratio was 1:1.9,and females comprised the majority.The ampullary region group accounted for 24.1%(7/29),while the nonampullary region group accounted for 75.9%(22/29).When diagnosed,the clinical symptoms of the ampullary region group were mainly abdominal pain(85.7%),while those of the nonampullary region groups were mainly abdominal distension(59.1%).There were differences in the composition of staging of tumours between the two groups(Fisher's exact probability method,P=0.001),with nonampullary stage II tumours(68.2%)being the main stage(P<0.05).After the diagnosis of DNETs,the survival rate of the ampullary region group was 14.3%(1/7),which was lower than that of 72.7%(16/22)in the nonampullary region group(Fisher's exact probability method,P=0.011).The survival time of the ampullary region group was shorter than that of the nonampullary region group(P<0.000).The median survival time of the ampullary region group was 10.0 months and that of the no

关键词： Duodenum Neuroendocrine Tumour Ampullary Nonampullary Clinical features Prognostic