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Failure mechanism and infrared radiation characteristic of hard siltstone induced by stratification effect

Journal of Mountain Science 2024年第3期21卷 1058-1074页

作者： cheng Yun song Zhanping XU Zhiwei YANG Tengtian tian Xiaoxu School of Civil Engineering Yancheng Institute of TechnologyYancheng 224051China School of Civil Engineering Xi'an University of Architecture and TechnologyXi'an 710055China Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering Xi'an 710055China China Railway Construction Bridge Engineering Bureau Group Co. Ltd.Tianjin 300300China

The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass.

关键词： Hard siltstone Failure mechanism Stratification effect Infrared radiation characteristic Temporal-damage mechanism Dissimilation

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Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： Yan Liu Qiu Tang Xin-cheng tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in manufacturing.For improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single Y-groove.Firstly,it summarizes the intersection forms and introduces a dual-pipe intersection model.Based on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is defined.Secondly,a novel mathematical model for plasma radius and taper compensation is established.Then,the compensation model and groove model are integrated by establishing movable frames.Thirdly,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is proposed.Through the established models and moving frames,the planned path description of cutting robot is provided in this novel scheme.The accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

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Evaluating quality of motion for unsupervised video object segmentation

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Optoelectronics Letters 2024年第6期20卷 379-384页

作者： cheng Guanjun song Huihui Jiangsu Key Laboratory of Big Data Analysis Technology Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment TechnologyNanjing University of Information Science&TechnologyNanjing 210044China12

Current mainstream unsupervised video object segmentation(UVOS) approaches typically incorporate optical flow as motion information to locate the primary objects in coherent video frames. However, they fuse appearance and motion information without evaluating the quality of the optical flow. When poor-quality optical flow is used for the interaction with the appearance information, it introduces significant noise and leads to a decline in overall performance. To alleviate this issue, we first employ a quality evaluation module(QEM) to evaluate the optical flow. Then, we select high-quality optical flow as motion cues to fuse with the appearance information, which can prevent poor-quality optical flow from diverting the network's attention. Moreover, we design an appearance-guided fusion module(AGFM) to better integrate appearance and motion information. Extensive experiments on several widely utilized datasets, including DAVIS-16, FBMS-59, and You Tube-Objects, demonstrate that the proposed method outperforms existing methods.

关键词： Evaluating quality of motion for unsupervised video object segmentation

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Prognostic factors associated with gastrointestinal dysfunction after gastrointestinal tumor surgery:A meta-analysis

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1420-1429页

作者： Jia song Cong Zhou tian Zhang Department of Operating Room The Fourth Affiliated Hospital of Nanjing Medical UniversityNanjing 210031Jiangsu ProvinceChina Department of Gastrointestinal Surgery Tongji Hospital of Huazhong University of Science and TechnologyWuhan 430073Hubei ProvinceChina Department of Disinfection Supply Center The Fourth Affiliated Hospital of Nanjing Medical UniversityNanjing 210031Jiangsu ProvinceChina

BACKGROUND Explore the risk factors of gastrointestinal dysfunction after gastrointestinal tumor surgery and to provide evidence for the prevention and intervention of gastrointestinal dysfunction in patients with gastrointestinal tumor surgery.AIM To investigate the potential risk factors for gastrointestinal dysfunction following gastrointestinal tumor surgery and to present information supporting the prevention and management of gastrointestinal dysfunction in surgery patients.METHODS Systematically searched the relevant literature from PubMed,Web of Science,Cochrane Library,Embase,CNKI,China Biomedical Database,Wanfang Database,and Weipu Chinese Journal Database self-established until October 1,2022.Review Manager 5.3 software was used for meta-analysis after two researchers independently screened literature,extracted data,and evaluated the risk of bias in the included studies.RESULTS A total of 23 pieces of literature were included,the quality of which was medium or above,and the total sample size was 43878.The results of meta-analysis showed that the patients were male(OR=1.58,95%CI:1.25-2.01,P=0.002)and≥60 years old(OR=2.60,95%CI:1.76-2.87,P<0.001),physical index≥25.3 kg/m2(OR=1.6,95%CI:1.00-1.12,P=0.040),smoking history(OR=1.89,95%CI:1.31-2.73,P<0.001),chronic obstructive pulmonary disease(OR=1.49,95%CI:1.22-1.83,P<0.001),enterostomy(OR=1.47,95%CI:1.26-1.70,P<0.001),history of abdominal surgery(OR=2.90,95%CI:1.67-5.03,P<0.001),surgical site(OR=1.2,95%CI:1.40-2.62,P<0.001),operation method(OR=1.68,95%CI:1.08-2.62,P=0.020),operation duration(OR=2.65,95%CI:1.92-3.67,P<0.001),abdominal adhesion grade(OR=2.52,95%CI:1.90-3.56,P<0.001),postoperative opioid history(OR=5.35,95%CI:3.29-8.71,P<0.001),tumor TNM staging(OR=2.58,95%CI:1.84-3.62,P<0.001),postoperative blood transfusion(OR=2.92,95%CI:0.88-9.73,P=0.010)is a risk factor for postoperative gastrointestinal dysfunction in patients with gastrointestinal tumors.CONCLUSION There are many factors affecting gastrointestinal dysfunction in gastrointestinal patients

关键词： Gastrointestinal tumor surgery Postoperative gastrointestinal dysfunction Intestinal paralysis Risk factors Metaanalysis

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Open-Shell Oligomers and Polymers: Theory, Characterization Methods, Molecular Design, and Applications

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Chinese Journal of Polymer Science 2024年第4期42卷 417-436页

作者： Xue-Qing Wang cheng song Ting Lei Key Laboratory of Polymer Chemistry and Physics(Ministry of Education) School of Materials Science and EngineeringPeking UniversityBeijing100871China

Open-shell oligomers and polymers have exhibited intriguing electronic and magnetic properties, making them highly desirable for a wide range of applications, including ambipolar organic field-effect transistors (OFETs), photodetectors, organic thermoelectrics, and spintronics. Although open-shell ground states have been observed in certain small molecules and doped organic semiconductors, the exploration of open-shell ground-state conjugated polymers is still limited, and the strategies for designing these polymers remain obscure. This review aims to briefly introduce the theory and characterization methods of open-shell conjugated polymers, along with an overview of recent progress and applications. The objective is to stimulate further advancements and investigations in this promising area by shedding light on the potential of open-shell conjugated polymers and the challenges that lie ahead.

关键词： Conjugated polymers Open-shell molecules High-spin ground state Donor-acceptor(D-A)polymers Optoelectronic and magnetic properties

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Small-diameter acellular porcine corneal stroma for peripheral corneal ulceration treatment

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 831-837页

作者： tian Liang Xia Wang Jie Wu Yan cheng Department of Ophthalmology Xi’an No.1 HospitalXi’an 710002Shaanxi ProvinceChina

AIM:To evaluate the clinical efficacy of small-diameter acellular porcine corneal stroma(SAPS)for the treatment of peripheral corneal ulceration(PCU).METHODS:This retrospective clinical study included 18 patients(18 eyes)with PCU between April 2018 and December 2020.All patients had PCU and underwent lamellar keratoplasty with SAPS.Observation indicators included preoperative and postoperative best-corrected visual acuity(BCVA)and transparency of SAPS.The infection control rate in the surgical eye-lesion area was also calculated.RESULTS:Eighteen patients underwent lamellar keratoplasty with SAPS to treat PCU.None of the patients experienced rejection after 6mo(18/18)and 12mo(16/16)of follow-up.The BCVA(0.47±0.30)at the 6mo followup after operation was significantly improved compared with the baseline(0.99±0.80),and the difference was statistically significant(Z=-3.415,P<0.05).The BCVA at the 12mo follow-up after operation was not statistically significant compared to the 6mo(Z=0,P=1).With time,the SAPS graft gradually became transparent.At the 6mo(18/18)and 12mo(16/16)follow-up,none of the patients had recurrent corneal infection.CONCLUSION:SAPS is clinically effective in the treatment of PCU,improving the patient’s BCVA and reducing the incidence of rejection after keratoplasty.

关键词： acellular porcine corneal stroma lamellar keratoplasty infectious corneal ulcer

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Diversity and ecological assembly process of aerobic anoxygenic phototrophic bacteria in a low irradiation area,Three Gorges Reservoir

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Journal of Environmental Sciences 2024年第9期143卷 116-125页

作者： Lixin Huo Anran Ma Hong Liu Xingzu Wang cheng song Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714China Chongqing School University of Chinese Academy of SciencesCollege of Resources and EnvironmentChongqing 400714China Key Laboratory of Reservoir Aquatic Environment Chinese Academy of SciencesChongqing 400714China University of Chinese Academy of Sciences Beijing 100049China

Aerobic anoxygenic phototrophic bacteria(AAPB)are significant bacterial groups in aquatic ecosystems,known for their rapid growth and photoheterotrophic characteristics.However,the distribution and ecological assembly process of AAPB in low irradiation freshwater basins remain unclear,warranting further investigation.In this study,we present the diversity,abundance,spatial variations,ecological process,and community interaction of AAPB in sediment of Three Gorges Reservoir(TGR)under low irradiation.Our findings demonstrate the dominant genera of AAPB community that exist in the TGR area also are appeared in different waters,with some regional preference.Moreover,the concentration of pufM gene,an indicator for AAPB,maintains a consistently high numerical level ranging from(2.21±0.44)×10^(4)to(9.98±0.30)×10^(7)gene copies/g.Although solar irradiation is suggested as the major factor affecting AAPB,it remains unclear whether and how AAPB differ between regions due to varying solar irradiation levels.Our results show spatial differences between total bacteria and AAPB communities,with significant differences observed only in AAPB.Geographical and environmental factor contributed less than 10%to the spatial difference of community,with sediment type and environmental factors being the key factors influencing microbial community structure.The stochastic process plays a dominant role in the aggregation and replacement of AAPB communities,among which the most contribution is dispersal limitation.For AAPB network,Yoonia and Gemmobacter are the hubs for modules.Those results valuable insights into the AAPB communities in TGR with low irradiation.

关键词： Three Gorges Reservoir(TGR) Aerobic anoxygenic phototrophic bacteria(AAPB) Bacterial community Null model Community assembly

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Boosting Fischer-Tropsch Synthesis via Tuning of N Dopants in TiO_(2)@CN-Supported Ru Catalysts

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Transactions of tianjin University 2024年第1期30卷 90-102页

作者： Xincheng Li Yunhao Liu Dejian Zhao Shuaishuai Lyu Jingwei Ye Xiaoshen Li Peipei Wu Ye tian Yingtian Zhang Tong Ding song song Qingpeng cheng Xingang Li State Key Laboratory of Chemical Engineering Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Haihe Laboratory of Sustainable Chemical TransformationsTianjin Key Laboratory of Applied Catalysis Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China Zhejiang Institute of tianjin University Shaoxing 312300China Sinopec Research Institute of Petroleum Processing Co. LTDBeijing 100083China Physical Sciences and Engineering Division Advanced Membranes and Porous Materials(AMPM)CenterKing Abdullah University of Science and Technology(KAUST)23955-6900 ThuwalSaudi Arabia

Nitrogen(N)-doped carbon materials as metal catalyst supports have attracted signifi cant attention,but the eff ect of N dopants on catalytic performance remains unclear,especially for complex reaction processes such as Fischer-Tropsch synthesis(FTS).Herein,we engineered ruthenium(Ru)FTS catalysts supported on N-doped carbon overlayers on TiO_(2)nanoparticles.By regulating the carbonization temperatures,we successfully controlled the types and contents of N dopants to identify their impacts on metal-support interactions(MSI).Our fi ndings revealed that N dopants establish a favorable surface environment for electron transfer from the support to the Ru species.Moreover,pyridinic N demonstrates the highest electron-donating ability,followed by pyrrolic N and graphitic N.In addition to realizing excellent catalytic stability,strengthening the interaction between Ru sites and N dopants increases the Ru^(0)/Ru^(δ+)ratios to enlarge the active site numbers and surface electron density of Ru species to enhance the strength of adsorbed CO.Consequently,it improves the catalyst’s overall performance,encompassing intrinsic and apparent activities,as well as its ability for carbon chain growth.Accordingly,the as-synthesized Ru/TiO_(2)@CN-700 catalyst with abundant pyridine N dopants exhibits a superhigh C_(5+)time yield of 219.4 mol CO/(mol Ru·h)and C_(5+)selectivity of 85.5%.

关键词： Fischer-Tropsch synthesis N-doped carbon materials Ruthenium catalyst Pyridinic N Metal-N interaction

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Functional Optical Fiber Sensors Detecting Imperceptible Physical/Chemical Changes for Smart Batteries

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Nano-Micro Letters 2024年第8期16卷 268-308页

作者： Yiding Li Li Wang Youzhi song Wenwei Wang cheng Lin Xiangming He Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084People’s Republic of China National Engineering Research Center of Electric Vehicles Beijing Institute of Technology(BIT)Beijing 100081People’s Republic of China Shenzhen Automotive Research Institute of BIT(Shenzhen Research Institute of National Engineering Research Center of Electric Vehicles) Shenzhen 518118People’s Republic of China

The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal state.The battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing parts.This paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety evolution.The paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”monitoring.Through the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed models.These advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system consistency.Furthermore,with the help of smart batteries in the future,the importance of consistency can be weakened or even eliminated.The application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.

关键词： Smart battery Advanced embedded optical fiber sensor Battery internal physical/chemical state Quality-reliability-life characteristic

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Observation of stabilized negative capacitance effect in hafnium-based ferroic films

Materials Futures

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Materials Futures 2024年第1期3卷 1-9页

作者： Leilei Qiao Ruiting Zhao cheng song Yongjian Zhou Qian Wang tian-Ling Ren Feng Pan Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Institute of Microelectronics&Beijing National Research Center for Information Science and Technology(BNRist) Tsinghua UniversityBeijing 100084People’s Republic of China

A negative capacitance(NC)effect has been proposed as a critical pathway to overcome the‘Boltzmann tyranny’of electrons,achieve the steep slope operation of transistors and reduce the power dissipation of current semiconductor devices.In particular,the ferroic property in hafnium-based films with fluorite structure provides an opportunity for the application of the NC effect in electronic devices.However,to date,only a transient NC effect has been confirmed in hafnium-based ferroic materials,which is usually accompanied by hysteresis and is detrimental to low-power transistor operations.The stabilized NC effect enables hysteresis-free and low-power transistors but is difficult to observe and demonstrate in hafnium-based films.This difficulty is closely related to the polycrystalline and multi-phase structure of hafnium-based films fabricated by atomic layer deposition or chemical solution deposition.Here,we prepare epitaxial ferroelectric Hf_(0.5)Zr_(0.5)O_(2) and antiferroelectric ZrO_(2) films with single-phase structure and observe the capacitance enhancement effect of Hf_(0.5)Zr_(0.5)O_(2)/Al_(2)O_(3) and ZrO_(2)/Al_(2)O_(3) capacitors compared to that of the isolated Al_(2)O_(3) capacitor,verifying the stabilized NC effect.The capacitance of Hf_(0.5)Zr_(0.5)O_(2) and ZrO_(2) is evaluated as−17.41 and−27.64 pF,respectively.The observation of the stabilized NC effect in hafnium-based films sheds light on NC studies and paves the way for low-power transistors.

关键词： negative capacitance effect fluorite structure hafnium-based ferroelectrics antiferroelectric

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