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Bending Failure Mode and Prediction Method of the Compressive Strain Capacity of A Submarine Pipeline with Dent Defects

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China Ocean Engineering 2024年第4期38卷 636-647页

作者： HOU Fu-heng JIA lu-sheng CHEN Yan-fei ZHANG Qi ZHONG Rong-feng WANG Chun-sha School of Mechanical and Transportation Engineering China University of PetroleumBeijingBeijing 102249China CNOOC Research Institute Ltd.Beijing 100028 China

A dent is a common type of defects for submarine *** submarine pipelines,high hydrostatic pressure and internal pressure are the main *** pipelines bend due to complex subsea conditions,the compression strain capacity may be *** into the local buckling failure and accurate prediction of the compressive strain capacity are important.A finite element model of a pipeline with a dent is *** buckling failure under a bending moment is investigated,and the compressive strain capacity is *** effects of different parameters on pipeline local buckling are *** results show that the dent depth,external pressure and internal pressure lead to different local buckling failure modes of the pipeline.A higher internal pressure indicates a larger compressive strain capacity,and the opposite is true for external *** the ratio of external pressure to collapse pressure of intact pipeline is greater than 0.1,the deeper the dent,the greater the compressive strain capacity of the *** as the ratio is less than 0.1,the opposite is *** the basis of these results,a regression equation for predicting the compressive strain capacity of a dented submarine pipeline is proposed,which can be referred to during the integrity assessment of a submarine pipeline.

关键词： submarine pipeline dent defect bending load local buckling compressive strain capacity

Carbene-catalyzed enantioselective seleno-Michael addition as access to antimicrobial active Se-containing heterocycles

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Science China Chemistry 2024年第7期67卷 2199-2205页

作者： Hongyan Long sha.Zhao Chunyan Jian Xiuli Wu Fengfei lu Minghong Liao Fengrui Che Xingxing Wu Yonggui Robin Chi State Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationGuizhou UniversityGuiyang 550025China School of Chemistry Chemical Engineeringand BiotechnologyNanyang Technological UniversitySingapore 637371Singapore

Organoseleniums exhibit a diverse set of biological activities that are pivotal for drug discovery and are widely explored in synthetic chemistry and material *** many transformations have been developed for non-enantioselective C–Se bond formations,the catalyst-controlled stereoselective preparation of chiral organoseleniums continues to be of considerable *** particular,there are limited studies on the enantioselective seleno-Michael addition reactions to access chiral selenium functional ***,we disclose a carbene-catalyzed highly enantioselective nucleophilic C–Se bond construction through formal[3+3]annulations between selenocarboxamides and bromoenals,affording seleno-thiazinone products with good yields and excellent *** choice of a weak inorganic base was pivotal to suppressing the unproductive racemization and decomposition of the selenium ***,the catalytically generated chiral selenium-containing heterocyclic products feature remarkable antimicrobial activities that could serve as promising lead scaffolds for further agrochemical development.

关键词： seleno-Michael addition organocatalysis N-heterocyclic carbene seleno-heterocycles antimicrobial activity

Spin-orbit torque effect in silicon-based sputtered Mn_(3)Sn film

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Chinese Physics B 2024年第10期33卷 394-399页

作者： sha.lu Dequan Meng Adnan Khan Ziao Wang Shiwei Chen Shiheng Liang School of Physics Hubei UniversityWuhan 430062China Key Laboratory for Intelligent Sensing System and Security of Ministry of Education Wuhan 430062China

Noncollinear antiferromagnet Mn_(3)Sn has shown remarkable efficiency in charge-spin conversion,a novel magnetic spin Hall effect,and a stable topological antiferromagnetic state,which has resulted in great interest from researchers in the field of spin-orbit *** research has primarily focused on the spin-orbit torque effect of epitaxially grown noncollinear antiferromagnet Mn_(3)Sn ***,this method is not suitable for large-scale industrial *** this study,amorphous Mn_(3)Sn films and Mn_(3)Sn/Py heterostructures were prepared using magnetron sputtering on silicon *** spin-torque ferromagnetic resonance measurement demonstrated that only the conventional spin-orbit torque effect generated by in-plane polarized spin currents existed in the Mn_(3)Sn/Py heterostructure,with a spin-orbit torque efficiency of ***,we prepared the perpendicular magnetized Mn_(3)Sn/CoTb heterostructure based on amorphous Mn_(3)Sn film,where the spin-orbit torque driven perpendicular magnetization switching was achieved with a lower critical switching current density(3.9×10^(7)A/cm^(2))compared to Ta/CoTb *** research reveals the spin-orbit torque effect of amorphous Mn_(3)Sn films and establishes a foundation for further advancement in the practical application of Mn_(3)Sn materials in spintronic devices.

关键词： spintronics noncollinear antiferromagnetism spin-orbit torque

Jamming Assisted Covert Wireless Communication in Multi-Channel Systems

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China Communications 2024年第9期21卷 211-224页

作者： Che Bohan sha.Nan Yang Weiwei lu Xingbo Gao Chang Army Engineering University of PLA Nanjing 210007China Beijing University of Posts and Telecommunications Beijing 100876China

This paper investigates the jammerassisted multi-channel covert wireless communication(CWC)by exploiting the randomness of sub-channel selection to confuse the *** particular,we propose two sub-channel selection transmission schemes,named random sub-channel selection(RSS)scheme and maximum sub-channel selection(MSS)scheme,to enhance communication *** each proposed scheme,we first derive closed-form expressions of the transmission outage probability(TOP),the average effective rate,and the minimum average detection error probability(DEP).Then,the average effective covert rate(ECR)is maximized by jointly optimizing the transmit power at the transmitter and the number of *** results show that there is an optimal value of the number of sub-channels that maximizes the average *** also find that to achieve the maximum average ECR,a larger number of subchannels are needed facing a stricter covertness constraint.

关键词： covert wireless communication jamming multi-channel system

Percutaneous ultrasound-guided coaxial core needle biopsy for the diagnosis of multiple splenic lesions: A case report

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 616-621页

作者： sha.Hong Pu Wu-Yong-Ga Bao Zhen-Peng Jiang Rui Yang Qiang lu Department of Medical Ultrasound West China Hospital of Sichuan UniversityChengdu 610041Sichuan ProvinceChina

BACKGROUND The overlap of imaging manifestations among distinct splenic lesions gives rise to a diagnostic ***,a definitive diagnosis primarily relies on his-tological *** ultrasound(US)-guided coaxial core needle biopsy(CNB)not only procures sufficient tissue to help clarify the diagnosis,but reduces the incidence of puncture-related *** SUMMARY A 41-year-old female,with a history of pulmonary tuberculosis,was admitted to our hospital with multiple indeterminate splenic ***-scale ultrasono-graphy demonstrated splenomegaly with numerous well-defined hypoechoic *** contrast-enhanced computed tomography(CT)showed an en-larged spleen with multiple irregular-sha.ed,peripherally enhancing,hypodense *** emission CT revealed numerous abnormal hyperglycemia *** imaging findings strongly indicated the possibility of infectious disease as the primary concern,with neoplastic lesions requiring *** obtain the precise pathological diagnosis,the US-guided coaxial CNB of the spleen was ca-rried *** patient did not express any discomfort during the *** Percutaneous US-guided coaxial CNB is an excellent and safe option for obtaining precise splenic tissue samples,as it significantly enhances sample yield for exact pathological analysis with minimum trauma to the spleen parenchyma and sur-rounding tissue.

关键词： Spleen Splenic disease Ultrasound Biopsy Ultrasound-guided coaxial core needle biopsy Case report

Synergistic PM_(2.5)and O_(3)control to address the emerging global PM_(2.5)-O_(3)compound pollution challenges

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Eco-Environment & Health 2024年第3期3卷 325-337页

作者： Chao He Jianhua Liu Yiqi Zhou Jingwei Zhou lu Zhang Yifei Wang lu Liu sha.Peng College of Resources and Environment Yangtze UniversityWuhan 430100China Hubei Key Laboratory of Petroleum Geochemistry and Environment Yangtze UniversityWuhan 430100China School of Geography and Ocean Science Nanjing UniversityNanjing 210023China Hydrology and Environmental Hydraulics Group Wageningen University and ResearchWageningen 6700 HBthe Netherlands State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China State Key Joint Laboratory for Environmental Simulation and Pollution Control School of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China State Key Laboratory of Pollution Control and Resource Reuse School of EnvironmentNanjing UniversityNanjing 210023China Collaborative Innovation Center for Emissions Trading System Co-constructed by the Province and Ministry Hubei University of EconomicsWuhan 430205China

In recent years,the issue of PM_(2.5)-O_(3)compound pollution has become a significant global environmental *** study examines the spatial and temporal patterns of global PM_(2.5)-O_(3)compound pollution and exposure risks,firstly at the global and urban scale,using spatial statistical regression,exposure risk assessment,and trend analyses based on the datasets of daily PM_(2.5)and surface O_(3)concentrations monitored in 120 cities around the world from 2019 to ***,on the basis of the common emission sources,spatial heterogeneity,interacting chemical mechanisms,and synergistic exposure risk levels between PM_(2.5)and O_(3)pollution,we proposed a synergistic PM_(2.5)-O_(3)control framework for the joint control of PM_(2.5)and *** results indicated that:(1)Nearly 50%of cities worldwide were affected by PM_(2.5)-O_(3)compound pollution,with China,South Korea,Japan,and India being the global hotspots for PM2.5-O3 compound pollution;(2)Cities with PM_(2.5)-O_(3)compound pollution have exposure risk levels dominated by ST t ST(Stabilization)and ST t HR(High Risk).Exposure risk levels of compound pollution in developing countries are significantly higher than those in developed countries,with unequal exposure characteristics;(3)The selected cities showed significant positive spatial correlations between PM_(2.5)and O_(3)concentrations,which were consistent with the spatial distribution of the precursors NOx and VOCs;(4)During the study period,52.5%of cities worldwide achieved synergistic reductions in annual average PM_(2.5)and O_(3)*** average PM_(2.5)concentration in these cities decreased by 13.97%,while the average O_(3)concentration decreased by 19.18%.This new solution offers the opportunity to construct intelligent and healthy cities in the upcoming low–carbon transition.

关键词： PM_(2.5)-O_(3)compound pollution Population exposure risk Spatial correlation Synergistic treatment potential

Mechanical behavior of sliding zone soil under compression considering periodic saturation-drying: example from a giant reservoir landslide

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Journal of Earth Science 2024年

作者： sha.lu Huiming Tang Liangqing Wang Xuexue Su Bing Lü Badong National Observation and Research Station of Geohazards， China University of Geosciences Faculty of Engineering， China University of Geosciences Wuhan， China

The reservoir landslide undergoes periodic saturation-drying cycles affected by reservoir fluctuation in hydropower project area， leading to the irreversible impact on the landslide materials. Sliding zone is the shearing part in formation of landslide and controls the further development of landslide. The mechanical behavior of sliding zone soil under compression is a crucial factor in the stability analysis in landslide. In this paper， the sliding zone soil from a giant landslide in the biggest hydropower project area， Three Gorges area， is taken as the research case. The particle-size distribution of the sliding zone soil from this landslide is studied and fractal dimension is adopted as representation. Periodic saturation-drying is introduced as the affecting factor on sliding zone soil properties. The triaxial compression test is conducted to reveal the mechanical behavior of the soil， including stress-strain behavior， elastic modulus， failure stress and strength parameters. These behavior of sliding zone soils with different fractal dimensions are studied under the effects of periodic saturation-drying cycles. The normalized stress-strain curves are displayed for further calculation. The data considering saturation-drying cycles are obtained and compared with the experimental results.

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Combined effect of cortical superficial siderosis and cerebral microbleed on short-term and long-term outcomes after intracerebral haemorrhage

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Stroke & Vascular Neurology 2024年第4期9卷 429-438,I0131-I0146页

作者： Yujia Jin Yu-hui Huang Yu-ping Chen Yao-dan Zhang Jiawen Li Kai-cheng Yang Xianghua Ye lu-hang Jin Jian Wu Chang-zheng Yuan Feng Gao lu-sha.Tong Neurology Department The Second Affiliated Hospital of Zhejiang UniversitySchool of MedicineHangzhouChina School of Public Health Zhejiang UniversityHangzhouChina Department of Neurology Tiantai People's Hospital of Zhejiang ProvinceTaizhouChina

Background and purpose Cortical superficial siderosis(cSS)and cerebral microbleed(CMB)have distinct effects on intracerebral haemorrhage(ICH).We aim to investigate the combined effect of cSS and CMB on outcomes after *** Based on a single-centre stroke registry database,patients with spontaneous ICH who had CT scan within 48 hours after ictus and MRI subsequently were *** patients were divided into four groups(cSS-CMB−,cSS-CMB+,cSS+CMB−,cSS+CMB+)according to cSS and CMB on susceptibility-weighted image of *** outcomes were haematoma volume on admission and unfavourable outcome defined as modified Rankin Scale scores≥3 at 3 *** outcomes were all-cause death,recurrence of stroke and ICH during follow-up(median follow-up 2.0 years,IQR 1.0-3.0 years).Results A total of 673 patients were identified from 1044 patients with spontaneous ICH.131(19.5%)had cSS and 468(69.5%)had *** with cSS+CMB+had the highest rate of poor outcome at 3 months,as well as all-cause death,recurrent stroke and ICH during *** cSS−patients,CMB was associated with smaller haematoma(β−0.13;95%CI−0.22 to−0.03;p=0.009),but it still increased risks of recurrent ICH(OR 4.6;95%CI 1.3 to 15.6;p=0.015)and stroke(OR 2.0;95%CI 1.0 to 4.0;p=0.049).These effects of CMB became unremarkable in the context of cSS+.Conclusions Patients with different combinations of cSS and CMB have distinct patterns of short-term and long-term *** CMB is related to restrained haematoma,it does not improve long-term outcomes.

关键词： superficial cerebral effect

Changes in visual performance after implantation of different intraocular lenses

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1273-1282页

作者： Bo-Wen Li Hao Huang Man-sha.Huang Shuang-Lin Guo lu Gao Yu-Ying Zeng lu Cheng Si-Yang Yao Jian-Qiang Lin Lin Liu Ye Yang Xiao-Ming lu Hao Cheng Department of Ophthalmology the First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou Medical UniversityGuangzhou 510000Guangdong ProvinceChina Eye Center of Xiangya Hospital Hunan Key Laboratory of OphthalmologyCentral South UniversityChangsha 410008Hunan ProvinceChina Department of Ophthalmology Zhuzhou Hospital Affiliated to Xiangya School of MedicineCentral South UniversityZhuzhou 412000Hunan ProvinceChina State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhou 510060Guangdong ProvinceChina Department of Ophthalmology Guangzhou Red Cross HospitalJinan UniversityGuangzhou 510000Guangdong ProvinceChina AIER Eye Hospital Jinan UniversityGuangzhou 510180Guangdong ProvinceChina

AIM:To evaluate the trending visual performance of different intraocular lenses(IOLs)over time after ***:Ninety-one patients received cataract surgery with implantations of monofocal(Mon)IOLs,segmental refractive(SegRef)IOLs,diffractive(Dif)IOLs,and extendeddepth-of-focus(EDoF)IOLs were *** aberrations and optical quality collected with iTrace and OQAS within postoperative 6mo were followed and ***:Most of the visual parameters improved over the postoperative *** postoperative visual acuity(POVA)of the Mon IOL,SegRef IOL,and EDoF IOL groups achieved relative stability in earlier states compared with the Dif IOL ***,the overall visual performance of the 3 IOLs continued to upturn in small extents within the postoperative *** optical quality initially improved in the EDoF IOL group,then in the Mon IOL,SegRef IOL,and Dif IOL *** and objective visual performance of the Mon IOL and EDoF IOL groups,as well as POVA and visual quality of the Dif IOL group,improved in the postoperative 1mo and *** the postoperative 6mo,gradual improvements were observed in the visual acuity and objective visual performance of the SegRef IOL group,as well as in the postoperative optical quality of the Dif IOL ***:The visual performance is different among eyes implanted with different *** findings of the current study provide a potential reference for ophthalmologists to choose suitable IOLs for cataract patients in a personalized solution.

关键词： intraocular lenses visual performance changing characteristics high-order wavefront aberration