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Numerical study on influence of protrusion heights on Reynolds stress and viscous stress variations in turbulent vortical structures

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Chinese Journal of Aeronautics 2024年第9期37卷 59-71页

作者： Zhiping LI long he Jingsai ZHOU Yueren ZUO Yao YIN Peng ZHANG Bo MENG Research Institute of Aero-Engine Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBejing 100191China Institute of Acoustics Chinese Academy of SciencesBeijing 100190China College of Aeronautical Engineering Civil Aviation University of ChinaTianjin 300300China AECC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China

Analysing the infuence mechanism of the riblet protrusion height on turbulent drag components is more beneficial in organising the vortical structure over the riblet ***,the Large Eddy Simulation(LES)is used to investigate the vortex structure over the rib-let surface with different protrusion ***,the variations of Reynolds stress and viscous shear stress in a turbulent channel are *** a result,the drag reduction rate increases from 3.4%when the riblets are completely submerged in the turbulent boundary layer to 7.9%when the protrusion height is *** analysis shows that the protrusion height affects the streamwise vortices and the normal diffusivity of spanwise and normal vortices,thus driving the variation of Reynolds *** with the smooth surface,the vorticity strength and the number of streamwise vortices are weakened near the wall but increase in the logarithmic layer with increased protrusion ***,the normal diffusivity of spanwise vorticity decreases with the increase of protrusion height,and the normal diffusivity of normal vorticity is the smallest when the protrusion height is ***,the protrusion height affects the velocity gradient of the riblet tip and riblet valley,thus driving the variation of viscous shear *** the increase of protrusion height,the velocity gradient of the riblet tip increases dramatically but decreases in the riblet valley.

关键词： Riblet Dragreduction Protrusion height Vortical structure Vortexdiffusivity Reynolds stress Viscous stress

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Beyond 1,4-addition of in-situ generated(aza-)quinone methides and indole imine methides

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Chinese Chemical Letters 2024年第7期35卷 35-53页

作者： Yan-Li Li Zhi-Ming Li Kai-Kai Wang Xiao-long he Medical College Xinxiang UniversityXinxiang 453000China School of Pharmacy Xinxiang UniversityXinxiang 453000China School of Food and Bioengineering Xihua UniversityChengdu 610039China

The conjugate addition of in-situ generated(aza-)quinone methides(QMs)and indole imine methides(IIMs)emerged as a powerful protocol to access densely functionalized benzenes and *** alcohols,aminobenzhydryl alcohols,and varied indolylmethanols served as most effective precursors for the in-situ generation of such reactive species under acid *** relevant propargylic alcohol has proven to be an elegant precursor to generate the propargylic-QMs and-IIMs via the acid promoted dehydration process,thus enabling diverse challenging remote activation to proceed conjugate1,6-and 1,***,the heteroarene has proven to be workable to transfer the LUMO of the p-QMs and 2-IIMs,thus inducing the remote nucleophilic dearomative *** conjugate additions of(aza-)p-QMs and varied IIMs has made significant contribution in the field of remote activation chemistry in past *** review summarizes the latest advances of the remote conjugate additions of the in-situ generated QMs and IIMs.

关键词： Conjugate addition QMs IIMs LUMO Remote activation Dearomative addition

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Novel P-doping-tuned Pd nanoflowers/S,N-GQDs photo-electrocatalyst for high-efficient ethylene glycol oxidation

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Chinese Chemical Letters 2024年第6期35卷 541-545页

作者： Xiaoxiao Huang Zhi-long he Yangpeng Chen Lei Li Zhenyu Yang Chunyang Zhai Mingshan Zhu School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China College of Biological Chemical Sciences and EngineeringJiaxing UniversityJiaxing 314001China Guangdong Key Lab oratory of Environmental Pollution and health School of EnvironmentJinan UniversityGuangzhou 510632China

Traditional photo-electcatalyst structures of small noble metal nanoparticles assembling into large-scale photoactive semiconductors still suffer from agglomeration of noble metal nanoparticles,insufficient charge transfer,undesirable photoresponse ability that restricted the photo-electrocatalytic *** this end,a novel design strategy is proposed in this work,namely integrating small-scale photoactive materials(doped graphene quantum dots,S,N-GQDs)with large-sized noble metal(Pd P)nanoflowers to form novel photo-electrocatalysts for high-efficient alcohol oxidation *** expected,superior electrocatalytic performance of Pd P/S,N-GQDs for ethylene glycol oxidation is acquired,thanks to the nanoflower structure with larger specific surface area and abundant active ***,nonmetal P are demonstrated,especially optimizing the adsorption strength,enhancing the interfacial contact,reducing metal agglomeration,ensuring uniform and efficient doping of S,N-GQDs,and ultimately significantly boost the catalytic activity of photo-electrocatalysts.

关键词： Non-metallic P–doping Sulfur nitrogen co-doped graphene quantum dots Pd nanoflowers Photo-electrocatalytic Ethylene glycol oxidation

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Insight into structural degradation of NCMs under extreme fast charging process

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Rare Metals 2024年第1期43卷 41-50页

作者： Yu Tang Xing-Yu Wang Jin-Can Ren Bo-Wen Chen Zhi-Yong Huang Wei Wang Ya-Lan Huang Bing-Hao Zhang Si Lan Zhang-long he Qi Liu Hao he Department of Physics City University of Hong KongHong Kong 999077China Shenzhen Research Institute City University of Hong KongShenzhen 518057China College of Materials Science and Engineering Changsha University of Science&TechnologyChangsha 410114China

Lithium-ion batteries(LIBs)with extreme fast charging(XFC)capability are considered an effective way to alleviate range anxiety for electric vehicle(EV)*** to the high ionic and electronic conductivity of LiNi_(x)Co_(y)Mn_zO_(2)(x+y+z=1,NCM)cathodes,the inevitable Li plating of graphite in NCM|graphite cell is usually identified as a key bottleneck for XFC ***,the capacity decay mechanism of cathode materials under XFC has not been fully *** this work,three typical NCM cathode materials with different Ni fractions were chosen and their electrochemical performances under XFC associated with structural evolution were investigated.A faster capacity decay of NCMs under XFC conditions is observed,especially for Ni-rich ***-situ X-ray diffraction(XRD)reveals that the multiple caxis parameters appear at the high-voltage regions in Nirich NCMs,which is probably triggered by the larger obstruction of Li(de)***,NCMs with moderate Ni fraction also present a similar trend under XFC *** phenomenon is more detrimental to the structural and morphological stability,resulting in a faster capacity decay than that under low current *** work provides new insight into the degradation mechanism of NCMs under XFC conditions,which can promote the development of NCM cathode materials with XFC capability.

关键词： Lithium-ion batteries Ni fraction Extreme fast charging Structural evolution

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Surface engineering on MnO_(2)nanorods by La single atoms to accelerate oxygen reduction kinetics

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Rare Metals 2024年第9期43卷 4302-4311页

作者： Zhang-long he Liu-Qi Wang Min Jiang Jia-Nan Xie Shan Liu Jin-Can Ren Rui Sun Wen-Bin Lv Wei-Bin Guo Yu-Ling Liu Bing Li Qi Liu Hao he School of Materials Science and Engineering Changsha University of Science and TechnologyChangsha 410000China School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Physics City University of Hong KongHong Kong 999077China

Surface engineering,which modulates the electronic structure and adsorption/desorption properties of electrocatalysts,is one of the key strategies for improving the catalytic ***,we demonstrate a facile solid-phase reaction for surface engineering of MnO_(2)to boost the oxygen reduction *** reaction with surface hydroxy groups,La single atoms with loading amount up to 2.7 wt%are anchored onto a-MnO_(2)*** surface engineering,the oxygen reduction reaction(ORR)kinetics is significantly improved with the half-wave potential from 0.70 to 0.84 V,the number of transferred electrons from 2.5 to 3.9 and the limiting current density from 4.8 to 6.0 mA·cm^(-2).In addition,the catalyst delivers superior discharge performance in both alkaline and neutral metal–air *** functional theory(DFT)calculations reveal that atomic La modulates the surface electronic configuration of MnO_(2),reduces its d-band center and thus lowers the OOH*and O*reaction energy *** work provides a new route for rational design of highly active electrocatalyst and holds great potential for application in various catalytic reactions.

关键词： Surface engineering Single atoms Electron injection Oxygen reduction reaction Metal-air batteries

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Enhanced detection of freeze‒thaw induced landslides in Zhidoi county(Tibetan Plateau,China)with Google Earth Engine and image fusion

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Advances in Climate Change Research 2024年第3期15卷 476-489页

作者： Jia-Hui YANG Yan-Chen GAO Lang JIA Wen-Juan WANG Qing-Bai WU Francis ZVOMUYA Miles DYCK Hai-long he College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Department of Soil Science University of Manitob1Winnipeg MB R3T 2N2Canada Department of Renewable Resources University of Albert1Edmonton AB T6G 2H1Canad

Freeze‒thaw induced landslides(FTILs)in grasslands on the Tibetan Plateau are a geological disaster leading to soil *** landslides reduce biodiversity and intensify landscape fragmentation,which in turn are strengthen by the persistent climate change and increased anthropogenic ***,conventional techniques for mapping FTILs on a regional scale are impractical due to their labor-intensive,costly,and time-consuming *** study focuses on improving FTILs detection by implementing image fusion-based Google Earth Engine(GEE)and a random forest *** of multiple data sources,including texture features,index features,spectral features,slope,and vertical‒vertical polarization data,allow automatic detection of the spatial distribution characteristics of FTILs in Zhidoi county,which is located within the Qinghai‒Tibet Engineering Corridor(QTEC).We employed statistical techniques to elucidate the mechanisms influencing FTILs *** enhanced method identifies two schemes that achieve high accuracy using a smaller training sample(scheme A:94.1%;scheme D:94.5%)compared to other methods(scheme B:50.0%;scheme C:95.8%).This methodology is effective in generating accurate results using only~10%of the training sample size necessitated by other *** spatial distribution patterns of FTILs generated for 2021 are similar to those obtained using various other training sample sources,with a primary concentration observed along the central region traversed by the *** results highlight the slope as the most crucial feature in the fusion images,accounting for 93%of FTILs occurring on gentle slopes ranging from 0°to 14°.This study provides a theoretical framework and technological reference for the identification,monitoring,prevention and control of FTILs in *** developments hold the potential to benefit the management of grassland ecosystem,reduce economic losses,and promote grassland sustainability.

关键词： Permafrost degradation Random forest Thaw slump Spatial distribution Tibetan Plateau

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Efficacy of Daoyin combined with lower limb robot as a comprehensive rehabilitation intervention for stroke patients: a randomized controlled trial

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Journal of Traditional Chinese Medicine 2024年第3期44卷 530-536页

作者： TIAN Haolin YANG Yuanbin ZHANG Hu ZHAO Wenjing ZHOU Jing TIAN Jingfeng he long LI Xuechao SheN Qinxuan SHUAI Mei Department of First Rehabilitation Wangjing Hospital of China Academy of Chinese Medical SciencesBeijing100102 Department of Rehabilitation Shunyi HospitalBeijing Traditional Chinese Medicine HospitalBeijing101300China School of Biological Science and Medical Engineering Beihang UniversityBeijing100191China

OBJECTIVE: To assess the effectiveness of a comprehensive rehabilitation approach combining Traditional Chinese Medicine Daoyin with lower limb robotics during the recovery phase of stroke ***: Stroke patients meeting the specified criteria were randomly assigned to one of four groups using a random number table: Control group, Daoyin group, lower limb robot group(LLR group), and Daoyin and lower limb robot group(DLLR group). Each group received distinct treatments based on conventional rehabilitation *** treatment duration spanned two weeks with two days of rest per week. Pre-and post-intervention assessments included various scales: Fugl-Meyer Assessment(FMA),Berg balance scale(BBS), Barthel index(BI), Fatigue Scale-14(FS-14), Pittsburgh sleep quality index(PSQI),Hamilton Anxiety Scale(HAMA), and Hamilton Depression Scale(HAMD).RESULTS: Statistically significant differences were observed in the lower limb function measured by FAM between the Control group(15 ± 5) and the DLLR group(18 ± 5)(P = 0.049). In the Barthel index, a statistically significant difference was noted between the Control group(54 ± 18) and the DLLR group(64 ± 11)(P = 0.041).Additionally, significant differences were found in the Berg balance scale between the Control group(21 ± 10)and the DLLR group(27 ± 8)(P = 0.024), as well as between the Control group(21 ± 10) and the LLR group(26 ± 10)(P = 0.048).CONCLUSION: The findings of this study suggest that the combined use of Daoyin and robotics not only enhances motor function in stroke patients but also has a positive impact on fatigue, sleep quality, and mood. This approach may offer a more effective rehabilitation strategy for stroke patients.

关键词： stroke rehabilitation Daoyin lower limb robot randomized controlled trial

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A nanoagent for concurrent therapy of breast cancer bone metastasis and cancer-induced bone pain through SLC7A11 interruption and photodynamic therapy

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Chinese Chemical Letters 2024年第2期35卷 295-299页

作者： Qi Fu Zhongming Lian Mengya Niu Yaru Huang Yanqiu Ai long he Dandan Zhang Cuixia Zheng Jian-Jun Yang Lei Wang Dandan Tian Department of Anesthesiology Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450001China School of Pharmaceutical Sciences Zhengzhou UniversityZhengzhou 450001China Translational Medical Center of Huaihe Hospital Henan UniversityKaifeng 475004China Key Laboratory of Advanced Drug Preparation Technologies Ministry of EducationSchool of Pharmaceutical SciencesZhengzhou UniversityZhengzhou 450001China

Bone metastasis,a life-threatening complication of advanced breast cancer,is often accompanied by debilitating pain(cancer-induced bone pain,CIBP)that severely impairs life quality and *** concurrent treatment of bone metastases and CIBP remains a clinical challenge because the therapeutic options are *** this study,we construct a near-infrared light-activated nano-therapeutic system to meet this *** detail,sorafenib(SRF)and photosensitizer(chlorin e6,Ce6)are encapsulated into mesoporous hydroxyapatite nanoparticles(HANPs),which are further functionalized with hyaluronic acid(HA)to obtain HA-SRF/Ce6@HANPs *** designed nanoplatform destroys tumor cells in vitro and in vivo via the synergism of SRF(interrupting the exchange of cystine/glutamate by inhibiting SLC7A11)and photodynamic therapy(PDT,inducing reactive oxygen species generation).The decrease in tumor burden and reduction of extracellular glutamate significantly attenuate CIBP in mice model with developing bone ***,the combination of HA-SRF/Ce6@HANPs and PDT inhibit osteoclasts activation,promote osteoblast differentiation and accelerate bone ***,the nanoagent with good biocompatibility may provide an effective therapy method for the concurrent treatment of breast cancer bone metastasis and CIBP.

关键词： Breast cancer bone metastasis Cancer-induced bone pain Cystine/glutamate antiporter Sorafenib Photodynamic therapy

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U-Pb dating of monazite in the Bainiuchang silver polymetallic deposit,Yunnan Province,and its limitation on Mesozoic mineralization

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China Geology 2024年第3期7卷 592-595页

作者： Bo-de Lu Wen-chang Li Xue-long Liu Guang-zhi Meng Qi-he long Hong Zhang Jun-shan Dao Fang-lan Li Jie-hu Zhou Mao-huang Fan Xue Mi Nan Shi Zhen-liang Cao College of Land Resources and Engineering Kunming University of Science and TechnologyKunming 650093China Geological Team 306 of Yunnan Non-ferrous Metals Geological Bureau Kunming 650217China Mengzi Mining and Metallurgy Co. Ltd.Mengzi 661199China

*** The Gejiu-Bozhushan-Laojunshan tin-tungsten polymetallic metallogenic belt is located in southeastern *** is bounded by the Mile-Shizong Fault and the Yangzi Plate to the north and west,respectively,while the Honghe Fault represents its southwestern *** is adjacent to the Ailaoshan Fault,and extends to Guangxi and Vietnam to the southeast(Fig.1a;Liu JP et al.,2021).

关键词： silver dating southeast

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Efficient and selective removal of Pb(Ⅱ) from landfill leachate using L-serine-modified polyethylene/polypropylene nonwoven fabric synthesized via radiation grafting technique

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Nuclear Science and Techniques 2024年第4期35卷 144-155页

作者： Xin-Xin Feng Cheng Li Xuan-Zhi Mao Wan-Ning Ren Yang Gao Yu-long he Zhe Xing Rong Li Guo-Zhong Wu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine *** effect of the absorbed dose was investigated in the range of 5–50 ***-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron *** adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of *** results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm *** saturated adsorption capacity was 198.1 mg/***-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and ***,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use *** coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.

关键词： Landfill leachate Radiation grafting Polyethylene/polypropylene nonwoven fabric Pb(Ⅱ)removal

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