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A novel relationship between elastic modulus and void ratio associated with principal stress for coral calcareous sand

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 1033-1048页

作者： Ran gao Jianhong ye State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Elastic moduli,e.***.shear modulus G and bulk modulus K,are important parameters of geotechnical materials,which are not only the indices for the evaluation of the deformation ability of soils but also the important basic parameters for the development of the constitutive models of geotechnical materials.In this study,a series of triaxial loading-unloading-reloading shear tests and isotropic loading-unloadingreloading tests are conducted to study several typical mechanical properties of coral calcareous sand(CCS),and the void ratio evolution during loading,unloading and reloading.The test results show that the stress-strain curves during multiple unloading processes are almost parallel,and their slopes are much greater than the deformation modulus at the initial stage of loading.The relationship between the confining pressure and the volumetric strain can be defined approximately by a hyperbolic equation under the condition of monotonic loading of confining pressure.Under the condition of confining pressure unloading,the evolution of void ratio is linear in the e-lnp0 plane,and these lines are a series of almost parallel lines if there are multiple processes of unloading.Based on the experimental results,it is found that the modified Hardin formulae for the elastic modulus estimation have a significant deviation from the tested values for CCS.Based on the experimental results,it is proposed that the elastic modulus of soils should be determined by the intersection line of two spatial surfaces in the G/K-e-p’/pa space(pa:atmosphere pressure).“ye formulation”is further proposed for the estimation of the elastic modulus of CCS.This new estimation formulation for soil elastic modulus would provide a new method to accurately describe the mechanical behavior of granular soils.

关键词： Coral calcareous sand(CCS) Elastic shear modulus Elastic bulk modulus Triaxial test Estimation formulation ye formulation

Understanding the educational inequalities in suicide attempts and their mediators:a Mendelian randomisation study

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General Psychiatry 2024年第1期37卷 133-142页

作者： Jiahao zhu Houpu Liu Rui gao Lilu Ding Jing Wang ye Yang Dan Zhou Yingjun Li Department of Epidemiology|and Health Statistics School of Public HealthHangzhou Medical CollegeHangzhouZhejiangChina Vanderbit Genetics Institute Vanderbilt University Medical CenterNashvilleTennesseeUSA School of Public Health and the Second Afliated Hospital Zhejiang University Schol of MedicineHangzhouZhejiangChina

Background Educational inequalities in suicide have become increasingly prominent over the past decade.Elucidating modifiable risk factors that serve as intermediaries in the impact of low educational attainment on suicide has the potential to reduce health disparities.Aims To examine the risk factors that mediate the relationship between educational attainment and suicide attempts and quantify their contributions to the mediation effect.Methods We conducted a two-sample Mendelian randomisation(MR)analysis to estimate the causal effect of educational attainment on suicide attempts,utilising genome-wide association study summary statistics from the Integrative Psychiatric Research(iPSYCH;6024 cases and 44240 controls)and FinnGen(8978 cases and 368299 controls).We systematically evaluated 42 putative mediators within the causal pathway connecting reduced educational attainment to suicide attempts and employed two-step and multivariable MR to quantify the proportion of the mediated effect.Results In the combined analysis of iPSYCH and FinnGen,each standard deviation(SD)decrease in genetically predicted educational attainment(equating to 3.4 years of education)was associated with a 105%higher risk of suicide attempts(odds ratio(OR):2.05;95%confidence interval(Cl):1.81 to 2.31).0f the 42 risk factors analysed,the two-step MR identified five factors that mediated the association between educational attainment and suicide attempts.The respective proportions of mediation were 47%(95%Cl:29%to 66%)for smoking behaviour,36%(95%Cl:0%to 84%)for chronic pain,49%(95%Cl:36%to 61%)for depression,35%(95%Cl:12%to 59%)for anxiety and 26%(95%Cl:18%to 34%)for insomnia.Multivariable MR implicated these five mediators collectively,accounting for 68%(95%Cl:40%to 96%)of the total effect.Conclusions This study identified smoking,chronic pain and mental disorders as primary intervention targets for attenuating suicide risk attributable to lower educational levels in the European population.

关键词： effect. random inequalities

Optimal Operation Strategy Analysis with Scenario Generation Method Based on Principal Component Analysis,Density Canopy,and K-medoids for Integrated Energy Systems

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 89-100页

作者： Bingtuan gao Yunyu zhu Yuanmei Li School of Electrical Engineering Southeast UniversityNanjingChina

The operation of integrated energy systems(IESs)is confronted with great challenges for increasing penetration rate of renewable energy and growing complexity of energy forms.Scenario generation is one of ordinary methods to alleviate the system uncertainties by extracting several typical scenarios to represent the original high-dimensional data.This paper proposes a novel representative scenario generation method based on the feature extraction of panel data.The original high-dimensional data are represented by an aggregated indicator matrix using principal component analysis to preserve temporal variation.Then,the aggregated indicator matrix is clustered by an algorithm combining density canopy and K-medoids.Together with the proposed scenario generation method,an optimal operation model of IES is established,where the objective is to minimize the annual operation costs considering carbon trading cost.Finally,case studies based on the data of Aachen,Germany in 2019 are performed.The results indicate that the adjusted rand index(ARI)and silhouette coefficient(SC)of the proposed method are 0.6153 and 0.6770,respectively,both higher than the traditional methods,namely K-medoids,K-means++,and density-based spatial clustering of applications with noise(DBSCAN),which means the proposed method has better accuracy.The error between optimal operation results of the IES obtained by the proposed method and all-year time series benchmark value is 0.1%,while the calculation time is reduced from 11029 s to 188 s,which verifies that the proposed method can be used to optimize operation strategy of IES with high efficiency without loss of accuracy.

关键词： Scenario generation principal component analysis(PCA) density canopy K-medoids integrated energy system

Efficient and bright broadband electroluminescence based on environmentfriendly metal halide nanoclusters

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Light(Science & Applications) 2024年第4期13卷 727-737页

作者： Dingshuo Zhang Meiyi zhu Yifan He Qingli Cao Yun gao Hongjin Li Guochao Lu Qiaopeng Cui Yongmiao Shen Haiping He Xingliang Dai Zhizhen ye School of Materials Science and Engineering State Key Laboratory of Silicon and Advanced Semiconductor MaterialsZhejiang University310027 HangzhouChina. Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials and Engineering Research Centre of Zhejiang Province Institute of WenzhouZhejiang University325006 WenzhouChina. Wenzhou XINXINTAIJING Tech.Co.Ltd. 325006 WenzhouChina. Department of Chemistry Zhejiang Sci-Tech University310018 HangzhouChina

Broadband electroluminescence based on environment-friendly emitters is promising for healthy lighting yet remains an unprecedented challenge to progress.The copper halide-based emitters are competitive candidates for broadband emission,but their high-performance electroluminescence shows inadequate broad emission bandwidth of less than 90 nm.Here,we demonstrate efficient ultra-broadband electroluminescence from a copper halide(CuI)nanocluster single emitter prepared by a one-step solution synthesis-deposition process,through dedicated design of ligands and subtle selection of solvents.The CuI nanocluster exhibits high rigidity in the excitation state as well as dual-emissive modes of phosphorescence and temperature-activated delayed fluorescence,enabling the uniform cluster-composed film to show excellent stability and high photoluminescent efficiency.In consequence,ultra-broadband light-emitting diodes(LEDs)present nearly identical performance in an inert or air atmosphere without encapsulation and outstanding high-temperature operation performance,reaching an emission full width at half maximum(FWHM)of~120 nm,a peak external quantum efficiency of 13%,a record maximum luminance of~50,000 cd m^(−2),and an operating half-lifetime of 137 h at 100 cd m^(−2).The results highlight the potential of copper halide nanoclusters for next-generation healthy lighting.

关键词： halide cluster rigidity

UAV-assisted cooperative offloading energy efficiency system for mobile edge computing

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Digital Communications and Networks 2024年第1期10卷 16-24页

作者： Xue-Yong Yu Wen-Jin Niu ye zhu Hong-Bo zhu Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing210003China Engineering Research Centerof Health Service System Based on Ubiquitous Wireless Nework Ministyof EducationNanjng Universityof Posts and Telecommunication Nanjing210003China

Reliable communication and intensive computing power cannot be provided effectively by temporary hot spots in disaster areas and complex terrain ground infrastructure.Mitigating this has greatly developed the application and integration of UAV and Mobile Edge Computing(MEC)to the Internet of Things(loT).However,problems such as multi-user and huge data flow in large areas,which contradict the reality that a single UAV is constrained by limited computing power,still exist.Due to allowing UAV collaboration to accomplish complex tasks,cooperative task offloading between multiple UAVs must meet the interdependence of tasks and realize parallel processing,which reduces the computing power consumption and endurance pressure of terminals.Considering the computing requirements of the user terminal,delay constraint of a computing task,energy constraint,and safe distance of UAV,we constructed a UAV-Assisted cooperative offloading energy efficiency system for mobile edge computing to minimize user terminal energy consumption.However,the resulting optimization problem is originally nonconvex and thus,difficult to solve optimally.To tackle this problem,we developed an energy efficiency optimization algorithm using Block Coordinate Descent(BCD)that decomposes the problem into three convex subproblems.Furthermore,we jointly optimized the number of local computing tasks,number of computing offloaded tasks,trajectories of UAV,and offloading matching relationship between multi-UAVs and multiuser terminals.Simulation results show that the proposed approach is suitable for different channel conditions and significantly saves the user terminal energy consumption compared with other benchmark schemes.

关键词： Computation offloading Internet of things(IoT) Mobile edge computing(MEC) Block coordinate descent(BCD)

Interfacial modification using the cross-linkable tannic acid for highly-efficient perovskite solar cells with excellent stability

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Journal of Energy Chemistry 2024年第4期91卷 236-244页

作者： Xing gao Lirong Rong Fei Wu yen-Hung Lin ye Zeng Junhong Tan Rongxing He Cheng Zhong Linna zhu Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energy School of Materials&EnergySouthwest UniversityChongqing 400715China Hubei Key Lab on Organic and Polymeric Optoelectronic Materials Department of ChemistryWuhan UniversityWuhan 430072HubeiChina Key Laboratory of Luminescence Analysis and Molecular Sensing Ministry of EducationSchool of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China Department of Electronic and Computer Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloon 999077Hong KongChina State Key Laboratory of Advanced Displays and Optoelectronics Technologies The Hong Kong University of Science and TechnologyClear Water BayKowloon 999077Hong KongChina

Although the performance of perovskite solar cells(PSCs)has been dramatically increased in recent years,stability is still the main obstacle preventing the PSCs from being commercial.PSC device instability can be caused by a variety of reasons,including ions diffusion,surface and grain boundary defects,etc.In this work,the cross-linkable tannic acid(TA)is introduced to modify perovskite film through post-treatment method.The numerous organic functional groups(–OH and C=O)in TA can interact with the uncoordinated Pb^(2+)and I^(-)ions in perovskite,thus passivating defects and inhibiting ions diffusion.In addition,the formed TA network can absorb a small amount of the residual moisture inside the device to protect the perovskite layer.Furthermore,TA modification regulates the energy level of perovskite,and reduces interfacial charge recombination.Ultimately,following TA treatment,the device efficiency is increased significantly from 21.31%to 23.11%,with a decreased hysteresis effect.Notably,the treated device shows excellent air,thermal,and operational stability.In light of this,the readily available,inexpensive TA has the potential to operate as a multipurpose interfacial modifier to increase device efficiency while also enhancing device stability.

关键词： Tannic acid Defect passivation lons diffusion Hydrophilic Stability Perovskite solar cells

Durable poly(binaphthyl-co-p-terphenyl piperidinium)-based anion exchange membranes with dual side chains

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Journal of Energy Chemistry 2024年第2期89卷 324-335,I0008页

作者： Weiting gao Xuelang gao Qiugen Zhang Aimei zhu Qinglin Liu Department of Chemical&Biochemical Engineering Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryThe College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 790-784South Korea

Building well-developed ion-conductive highways is highly desirable for anion exchange membranes(AEMs).Grafting side chain is a highly effective approach for constructing a well-defined phaseseparated morphological structure and forming unblocked ion pathways in AEMs for fast ion transport.Fluorination of side chains can further enhance phase separation due to the superhydrophobic nature of fluorine groups.However,their electronic effect on the alkaline stability of side chains and membranes is rarely reported.Here,fluorine-containing and fluorine-free side chains are introduced into the polyaromatic backbone in proper configuration to investigate the impact of the fluorine terminal group on the stability of the side chains and membrane properties.The poly(binaphthyl-co-p-terphenyl piperidinium)AEM(QBNp TP)has the highest molecular weight and most dimensional stability due to its favorable backbone arrangement among ortho-and meta-terphenyl based AEMs.Importantly,by introducing both a fluorinated piperidinium side chain and a hexane chain into the p-terphenyl-based backbone,the prepared AEM(QBNp TP-QFC)presents an enhanced conductivity(150.6 m S cm^(-1))and a constrained swelling at 80℃.The electronic effect of fluorinated side chains is contemplated by experiments and simulations.The results demonstrate that the presence of strong electro-withdrawing fluorine groups weakens the electronic cloud of adjacent C atoms,increasing OH^(-)attack on the C atom and improving the stability of piperidinium cations.Hence QBNp TP-QFC possesses a robust alkaline stability at 80℃(95.3%conductivity retention after testing in 2 M Na OH for 2160 h).An excellent peak power density of 1.44 W cm^(-2)and a remarkable durability at 80℃(4.5%voltage loss after 100 h)can be observed.

关键词： Anion exchange membranes Backbone structure Fluorinated side chain Alkaline stability

Efficacy and safety of transvaginal mesh repair in a cohort with a minimum of 10-year follow-up

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Science China(Life Sciences) 2024年第5期67卷 1061-1068页

作者： Zhibo Zhang Jianbin Guo Weijie Tian ye Zhang Yuelun Zhang Tianshu Sun Jiali Duan Xinmiao Bao Yuan Wang Yang ye Qianqian gao Honghui Shi Abraham Nick Morse Juan Chen Lan zhu Departmentof Obstetrics and Gynecology Peking Union MedicalCollege HospitalChinese Academyof Medical Sciences&Peking Union MedicalCollegeNational Clinical Research Center for Obstetricand Gynecologic DiseasesBeijing 100730China Department of Gynecology Guizhou Provincial People’s HospitalMedical College of Guizhou UniversityGuiyang 550002China Department of Obstetrics and Gynecology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000China Medical Research Center Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Medical Doctor Program Chinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Department of Pathology Peking Union Medical College HospitalBeijing 100730China Tufts University School of Medicine Boston MA 02111USA

Although transvaginal mesh(TVM)repair is no longer used in some countries,long-term outcomes after TVM surgery are of great importance globally.However,reports with follow-up>10 years are limited.Thus,this study aimed to report outcomes in a prospective cohort with at least 10 years of follow-up.Women with stageⅢ–Ⅳsymptomatic prolapse were approached consecutively from 2008 to 2013 at one tertiary hospital.The main outcome measure was symptomatic failure.Secondary outcomes included anatomic failure,recurrence,patient satisfaction,complications,and reoperation.The Kaplan-Meier curve was used to estimate the cumulative failure rate.Of the 121 patients enrolled in the study,103(85.1%)completed a median follow-up of 11 years.The estimated probability rates of symptomatic and anatomic failure were 17.6%and 8.8%in 11 years,respectively.The estimated incidence of symptomatic failure increased by 8.2%between 5 and 11 years;however,the corresponding rate for anatomic failure was 3.7%.The most common complication was vaginal mesh exposure,and its estimated probability increased from 19.3%to 28.4%from 5 to 11 years,respectively.Office trimming resolved 80.0%of vaginal exposures.These patients did not report decreased overall satisfaction.Patients with vaginal mesh exposure requiring>3 office procedures or mesh removal in the operating room(5.8%by 11 years)had lower satisfaction rates(P<0.01)and were defined as having severe mesh exposure.The rates of postoperative pain,reoperation,and Patient Global Impression of Improvement≥2 were 2.5%,3.3%,and 94.2%,respectively.The results of this study implied that TVM treatment gradually increased the symptomatic failure rate but provided durable anatomical support of the vaginal wall.Vaginal mesh exposure was common in women who were largely not sexually active;however,80%of the cases could be managed in the outpatient clinic,which did not affect patient satisfaction.

关键词： complication efficacy long-term follow-up pelvic organ prolapse safety transvaginal mesh

Tuning the surface electronic structure of noble metal aerogels to promote the electrocatalytic oxygen reduction

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Journal of Energy Chemistry 2024年第2期89卷 557-564,I0013页

作者： Hongxing Yuan Wei gao Xinhao Wan Jianqi ye Dan Wen State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072ShaanxiChina

The sluggish kinetics of the oxygen reduction reaction(ORR)is the bottleneck for various electrochemical energy conversion devices.Regulating the electronic structure of electrocatalysts by ligands has received particular attention in deriving valid ORR electrocatalysts.Here,the surface electronic structure of Ptbased noble metal aerogels(NMAs)was modulated by various organic ligands,among which the electron-withdrawing ligand of 4-methylphenylene effectively boosted the ORR electrocatalysis.Theoretical calculations suggested the smaller energy barrier for the transformation of O^(*) to OH^(*) and downshift the d-band center of Pt due to the interaction between 4-methylphenylene and the surface metals,thus enhancing the ORR intrinsic activity.Both Pt3Ni and Pt Pd aerogels with 4-methylphenylene decoration performed significant enhancement in ORR activity and durability in different media.Remarkably,the 4-methylphenylene modified Pt Pd aerogel exhibited the higher halfwave potential of 0.952 V and the mass activity of 10.2 times of commercial Pt/C.This work explained the effect of electronic structure on ORR electrocatalytic properties and would promote functionalized NMAs as efficient ORR electrocatalysts.

关键词： Noble metal aerogels Surface electronic structure ORR Electrocatalyst Organic ligands