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Investigation of mechanical failure performance of a large-diameter shield tunnel segmental ring

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第5期25卷 411-428页

作者： Binyong GAO Renpeng CHEN Huaina WU Chengcheng ZHANG meng fan Chao XIAO Research Center of Underground Space Advanced Technology Hunan UniversityChangsha 410082China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha 410082China Department of Civil Engineering Hunan UniversityChangsha 410082China China Construction No.5 Civil Engineering Co. Ltd.Changsha 410004China

The control criteria for structural deformation and the evaluation of operational safety performance for large-diameter shield tunnel segments are not yet clearly *** address this issue,a refined 3D finite element model was established to analyze the transverse deformation response of a large-diameter segmental *** analyzing the stress,deformation,and crack distribution of large-diameter segments under overload conditions,the transverse deformation of the segmental ring could be divided into four *** main reasons for the decrease in segmental ring stiffness were found to be the extensive development of cracks and the complete formation of four plastic *** deformation control value for the large-diameter shield tunnel segment is chosen as 8%o of the segment's outer diameter,representing the transverse deformation during the formation of the first semi-plastic hinge(i.e.,the first yield point)in the *** control value can serve as a reinforcement standard for preventing the failure of large-diameter shield tunnel *** flexural bearing capacity characteristic curve of segments was used to evaluate the structural strength of a large-diameter segmental *** was discovered that the maximum internal force combination of the segment did not exceed the segment ultimate bearing capacity curve(SUBC).However,the combination of internal force at 9°,85°,and 161°of the joints,and their symmetrical locations about the 0°-180°axis exceeded the joint ultimate bearing capacity curve(JUBC).The results indicate that the failure of the large-diameter segment lining was mainly due to insufficient joint strength,leading to an instability *** findings from this study can be used to develop more effective maintenance strategies for large-diameter shield tunnel segments to ensure their long-term performance.

关键词： Finite element model Transverse deformation response Upper overload Plastic hinges Flexural bearing capacity

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Recent advances in promising drugs for primary prevention of gastroesophageal variceal bleeding with cirrhotic portal hypertension

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 4-13页

作者： Ji-Yao Sheng Zi-fan meng Qiao Li Yong-Sheng Yang Department of Hepatobiliary and Pancreatic Surgery the Second Hospital of Jilin UniversityChangchun 130041China Jilin Engineering Laboratory for Translational Medicine of Hepatobiliary and Pancreatic Diseases the Second Hospital of Jilin UniversityChangchun 130041China

Background:Gastroesophageal variceal bleeding is one of the most severe complications of patients with *** primary prevention drugs,including non-selectiveβ-blockers,have effectively reduced the incidence of bleeding,their efficacy is limited due to side effects and related *** recent advances in precision medicine,precise drug treatment provides better treatment *** sources:Literature search was conducted in PubMed,MEDLINE and Web of Science for relevant articles published up to May *** on clinical trials was obtained from https://***/and http://***/.Results:The in-depth understanding of the pathogenesis and advances of portal hypertension has enabled the discovery of multiple molecular targets for promising *** to the site of action,these drugs could be classified into four classes:intrahepatic,extrahepatic,both intrahepatic and extrahepatic targets and *** these classes of drugs offer advantages over traditional treatments in prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal ***:This review classified and summarized the promising drugs,which prevent gastroesophageal variceal bleeding by targeting specific markers of pathogenesis of portal hypertension,demonstrating the significance of using the precision medicine strategy to discover and develop promising drugs for the primary prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal hypertension.

关键词： Cirrhotic portal hypertension Target drug Primary prevention Bleeding

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Improving photochemical indicators for attributing ozone sensitivities in source apportionment analysis

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Journal of Environmental Sciences 2024年第9期143卷 235-246页

作者： Xiaohui Du Wei Tang Zhongzhi Zhang Yang Yu Yang Li Ling Huang Greg Yarwood fan meng Atmospheric Environment Institute Chinese Research Academy of Environmental SciencesBeijing 100012China College of Water Sciences Beijing Normal UniversityBeijing 100857China Asia Center for Air Pollution Research United Nations Environment Programme Asia and the Pacific OfficeNishi-kuNiigata-shi 9502144Japan School of Environmental and Chemical Engineering Shanghai UniversityShanghai 200444China Ramboll NovatoCalifornia 94945USA

Comprehensive Air Quality Model with extensions(CAMx)-Decoupled Direct Method(DDM)simulations of first-order ozone(O_(3))sensitivity to nitrogen oxides(NO_(x))and volatile organic compounds(VOCs)emissions were performed and combined with modelled P_(H_(2)O_(2))/P_(HNO_(3))ratios to obtain a range of thresholds for determining O_(3)-sensitivity regimes for different areas of *** the new threshold ranges for photochemical indicators,the method for determining O_(3)formation in the Ozone Source Apportionment Technology(OSAT)module within CAMx was improved by a dynamically varied threshold of P_(H_(2)O_(2))/P_(HNO_(3))*** O_(3)concentration contributions in the newly added transition regime were apportioned to NO_(x)and VOCs emissions in proportion to the relationship between the P_(H_(2)O_(2))/P_(HNO_(3))ratio and first-order O_(3)*** source contributions of O_(3)concentrations from different emission sectors from June to September 2019 were compared using the original and improved *** results showed that the O_(3)concentration contributions changed significantly in the NO_(x)-limited regime,with a maximum decrease of 21.89%,while the contributions increased by up to 7.57%in the VOC-limited regime,and were within 15μg/m^(3)in the transition *** modified OSAT module enabled a more sophisticated attribution of O_(3)to precursor emissions and may have far-reaching implications for informing O_(3)pollution control policy.

关键词： O_(3) modeling O_(3)-sensitivity regimes Ozone source apportionment technology Photochemical indicators

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Microstructures and mechanical properties of a commercial Mg-Al-Zn-Mn alloy with various hot-extrusion processes

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Rare Metals 2024年第3期43卷 1329-1336页

作者： He Ma fan-Zhi meng Qiang Yang Ze-Feng Xie Yuan-Ding Huang Xin Qiu State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun130022China MagIC-Magnesium Innovation Center Helmholtz-Zentrum Geesthacht21502GeesthachtGermany Engineering Research Center of Optoelectronic Functional Materials Ministry of EducationChangchun University of Science and TechnologyChangchun130022China

Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg... 详细信息

关键词： alloys alloy corrosion

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Preoperative prediction of hepatocellular carcinoma microvascular invasion based on magnetic resonance imaging feature extraction artificial neural network

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2546-2554页

作者： Jing-Yi Xu Yu-fan Yang Zhong-Yue Huang Xin-Ye Qian fan-Hua meng Center of Hepatobiliary Pancreatic Disease Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Department of Surgical Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Department of Anesthesiology Huashan HospitalFudan UniversityShanghai 200040China

BACKGROUND Hepatocellular carcinoma(HCC)recurrence is highly correlated with increased *** invasion(MVI)is indicative of aggressive tumor biology in *** To construct an artificial neural network(ANN)capable of accurately predicting MVI presence in HCC using magnetic resonance *** This study included 255 patients with HCC with tumors<3 *** annotated the tumors on the T1-weighted plain MR ***,a three-layer ANN was constructed using image features as inputs to predict MVI status in patients with *** pathological examination is considered the gold standard for determining *** operating characteristic analysis was used to evaluate the effectiveness of the *** Using the bagging strategy to vote for 50 classifier classification results,a prediction model yielded an area under the curve(AUC)of ***,correlation analysis revealed that alpha-fetoprotein values and tumor volume were not significantly correlated with the occurrence of MVI,whereas tumor sphericity was significantly correlated with MVI(P<0.01).CONCLUSION Analysis of variable correlations regarding MVI in tumors with diameters<3 cm should prioritize tumor *** ANN model demonstrated strong predictive MVI for patients with HCC(AUC=0.79).

关键词： Hepatocellular carcinoma Microvascular invasion Artificial neural network Magnetic resonance imaging Tumor sphericity Area under the curve

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Spatiotemporal mapping of(ultra‐)mafic magmatic mine areas:Implications of economic and political realities in China

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Deep Underground Science and Engineering 2024年第1期3卷 91-102页

作者： Heling Li Liang Tang Tim T.Werner Zhengmeng Hou fan meng Jingjing Li College of Earth Sciences Chengdu University of TechnologyChengduChina Institute of Subsurface Energy Systems Clausthal University of TechnologyClausthal ZellerfeldGermany School of Geography Earth and Atmospheric SciencesFaculty of ScienceThe University of MelbourneMelbourneVictoriaAustralia

The spatiotemporal extension/expansion of mine areas is affected by multiple *** far,very little has been done to examine the interaction between mine areas and political or economic ***(ultra‐)mafic magmatic mines in China played a specific role in supporting national development and providing an ideal research subject for monitoring their *** this study,remote sensing and mining‐related GIS data were used to identify and analyze 1233(ultra‐)mafic magmatic mine area polygons in China,which covered approximately 322.96 km2 of land and included a V–Ti–Fe mine,a copper–nickel mine,a chromite mine,an asbestos mine,and a diamond *** was found that(1)the areal expansion of mines is significantly related to the mine types,perimeter,topography,and population density.(2)The mine area variation also reflects market and policy *** temporal expansion of the mine area from 2010 to 2020 followed an S‐shaped pattern(with the turning point occurring in 2014),closely related to iron overcapacity and tightened mining policies.(3)The complexity(D)of the mine area may reflect mine design and excavation *** be specific,lower D indicates early‐stage or artisanal/small‐scale mining,whereas higher D represents large‐scale *** study demonstrates that the detailed mapping of mine land can serve as an indicator to implement miningrelated market and policy ***(ultra‐)mafic mines area data set can be accessed at https://***/record/7636616#.Y-p0uXaZOa0.

关键词： complexity mine area mining and socioeconomic interaction spatiotemporal distribution (ultra‐)mafic magmatic mine

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Enhanced Crystallization of Poly(butylene adipate-co-terephthalate)by a Self-assembly Nucleating Agent

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Chinese Journal of Polymer Science 2024年第5期42卷 663-674,I0010页

作者： Cheng Zhou Kun Chen Zi-Heng Zhang meng-fan Jing Chun-Tai Liu Chang-Yu Shen Ya-Ming Wang State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentNational Engineering Research Center for Advanced Polymer Processing TechnologyZhengzhou UniversityZhengzhou450002China

Poly(butylene adipate-co-terephthalate)(PBAT)is a promising biodegradable flexible polymer but suffers from slow crystallization rate,making it less attractive for some applications like the injection-molded products in comparison with low-density polyethylene(LDPE).This work aimed to accelerate the crystallization of PBAT by adding a self-assembly nucleating agent octamethylenedicarboxylic dibenzoylhydrazide(OMBH).PBAT/OMBH composites with various OMBH contents(0 wt%,0.5 wt%,0.7 wt%,1 wt%,2 wt%,3 wt%and 5 wt%)were prepared through *** effect of OMBH on the crystallization behavior,morphologies and mechanical properties of PBAT was *** highest nucleation efficiency value of 59.6%was achieved for PBAT with 0.7 wt%OMBH,much higher than that of 22.7%for PBAT with 0.7 wt%*** force microscopy results showed that OMBH formed fine fibers and induced the formation of transcrystalline layers of *** transform infrared spectroscopy(FTIR)combined with two-dimensional correlation spectra suggested that the intermolecular dipole-dipole N—H…O=C interactions but not hydrogen bond between OMBH and PBAT promoted the crystallization of PBAT in the initial period of *** presence of OMBH did not change the crystal form of PBAT but had positive contribution in enhancing its crystallinity and mechanical *** work is essential for preparing PBAT with high crystallization rate,enhancing its potential applications in injection-molded products.

关键词： Poly(butylene adipate-co-terephthalate) Biodegradable Self-assembly nucleating agent Crystallization

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Continuous-flow enzymatic synthesis of chiral lactones in a three-dimensional microfluidic reactor

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Chinese Chemical Letters 2024年第3期35卷 299-303页

作者： Xuelei Deng meng fan Miao Wu Xiaoyan Zhang Ya Cheng Jianye Xia Yingping Zhuang Weiping Zhu Xuhong Qian Yunpeng Bai State Key Laboratory of Bioreactor Engineering Shanghai Collaborative Innovation Center for BiomanufacturingEast China University of Science and TechnologyShanghai 200237China The Extreme Optoelectromechanics Laboratory School of Physics and Materials ScienceEast China Normal UniversityShanghai 200241China Tianjin Institute of Industrial Biotechnology Chinese Academy of SciencesTianjin 300308China

A new continuous-flow process for the enzymatic synthesis of optically pureγ-lactones,which are used as flavors and fragrances in the food and cosmetic industries,was developed in a three-dimensional microfluidic *** microchannels(175 mm in length,0.9 mm in depth,and 1.72 mL in volume)were carved precisely inside a single borosilicate glass(90 mm×75 mm×12 mm)with ultrafast femtosecond laser *** flow field analysis and reaction simulation showed that the mixing of substrates and enzymes was enhanced,allowing the adjustment of residence time in a wide ***_(V4),a carbonyl reductase with excellent catalytic activity and enantioselectivity towardγ/δ-keto acids,was employed for the asymmetric synthesis of various chiral lactones.30 mmol/L(R)-γ-decalactone(3g)can be obtained in 26 s with a space-time yield(STY)up to 16,877 g L^(-1)d^(-1),which is 14.4 times higher than the highest STY of batch reaction reported *** continuous-flow process was applied to the synthesis of 6 chiral *** addition,the scaled-up synthesis of 3g was carried out in 6 cascade microreactors continuously for 6 h,demonstrating the feasibility and stability of the 3D continuous-flow process in enzymatic synthesis of optically pure compounds.

关键词： Continuous-flow Flow chemistry Microreactor Biocatalysis Carbonyl reductase Asymmetric reduction

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Mental health and insomnia problems in healthcare workers after the COVID-19 pandemic:A multicenter cross-sectional study

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World Journal of Psychiatry 2024年第5期14卷 704-714页

作者： Wei Ding Min-Zhong Wang Xian-Wei Zeng Zhen-Hua Liu Yao meng Hui-Ting Hu Yuan Zhang Yu-Guang Guan fan-Gang meng Jian-Guo Zhang Shu Wang Department of Public Health Liaocheng People’s HospitalLiaocheng 252000Shandong ProvinceChina Department of Neurology Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250021Shandong ProvinceChina Department of Neurosurgery Qilu Hospital of Shandong UniversityJinan 250012Shandong ProvinceChina Sleep Medicine Center Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinan 250021Shandong ProvinceChina Department of Neurology The First Affiliated Hospital of Shandong First Medical UniversityJinan 250014Shandong ProvinceChina Department of Neurology Heze Mudan People’s HospitalHeze 274000Shandong ProvinceChina Neonatal Center Beijing Children's HospitalCapital Medical UniversityNational Center for Children's HealthBeijing 100045China Department of Neurosurgery SanBo Brain HospitalCapital Medical UniversityBeijing 100093China Department of Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China

BACKGROUND Healthcare workers(HCWs)are at increased risk of contracting coronavirus disease 2019(COVID-19)as well as worsening mental health problems and *** problems can persist for a long period,even after the ***,less is known about this *** To analyze mental health,insomnia problems,and their influencing factors in HCWs after the COVID-19 *** This multicenter cross-sectional,hospital-based study was conducted from June 1,2023 to June 30,2023,which was a half-year after the end of the COVID-19 ***-stratified population-based cluster sampling was applied at the provincial level for Chinese *** such as anxiety,depression,and insomnia were evaluated by the Generalized Anxiety Disorder-7,Patient Health Questionnaire-9,and Insomnia Severity *** influencing the symptoms were identified by multivariable logistic *** A total of 2000 participants were invited,for a response rate of 70.6%.A total of 1412 HCWs[618(43.8%)doctors,583(41.3%)nurses and 211(14.9%)nonfrontline],254(18.0%),231(16.4%),and 289(20.5%)had symptoms of anxiety,depression,and insomnia,respectively;severe symptoms were found in 58(4.1%),49(3.5%),and 111(7.9%)of the ***,female sex,and hospitalization for COVID-19 were risk factors for anxiety,depression,and insomnia symptoms;moreover,death from family or friends was a risk factor for insomnia *** the COVID-19 outbreak,most[1086(76.9%)]of the participating HCWs received psychological interventions,while nearly all[994(70.4%)]of them had received public psychological *** 102(7.2%)of the HCWs received individual counseling from *** Although the mental health and sleep problems of HCWs were relieved after the COVID-19 pandemic,they still faced challenges and greater risks than did the general *** risk factors would help in providing targeted *** addition,although a major proportion of

关键词： COVID-19 Mental health Psychological symptoms Insomnia Sleep disorders Cross-sectional study Epidemiological study

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“威士忌酒叛乱”与美国早期的民众“法外行动”

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史学月刊 2024年第10期 80-95页

作者：孟凡复旦大学历史系上海200433

殖民地时期以来,印白种族之间的残酷冲突,殖民地政府对西部民众诉求的漠视,在宾夕法尼亚西部催生了一种武装自治的传统和诉诸暴力的偏好。不过,在爆发于1791年且持续4年之久的“威士忌酒叛乱”中,针对政府的民众暴力抗争在残酷性和破坏... 详细信息

殖民地时期以来,印白种族之间的残酷冲突,殖民地政府对西部民众诉求的漠视,在宾夕法尼亚西部催生了一种武装自治的传统和诉诸暴力的偏好。不过,在爆发于1791年且持续4年之久的“威士忌酒叛乱”中,针对政府的民众暴力抗争在残酷性和破坏力上始终保持在一个较低水平上。一方面,施暴者通过高度仪式化的暴力活动,避免了严重的身体伤害;另一方面,地方社区凭借相沿成习的政治惯例组织抗议运动,防止了内战的发生。“叛乱”爆发后,各界人士普遍批评民众采用暴力手段抵制联邦政策不合时宜,并将这一“叛乱”事件作为塑造美国“非暴力”特性的素材。抗税民众的暴力实践颇具代表性地呈现出美国早期民众“法外行动”的历史源流和基本特点,而美国社会和政府对这一事件的态度和处理方式则反映出暴力问题对美国早期国族构建的深远影响。

关键词：早期美国 “威士忌酒叛乱” 抗税骚乱 “法外行动” 大众政治文化

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