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A new strategy for managing presacral venous hemorrhage：bipolar coagulation hemostasis

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Chinese Medical Journal 2010年第23期123卷 3486-3488页

作者： LI Yu-yan CHEN yong XU hui-cheng WANG Dan LIANG Zhi-qing Department of Obstetrics and Gynecology Southwest HospitalThird Military Medical University Chongqing 400038 China

Massive presacral venous hemorrhage is dangerous and difficult to manage. Traditional methods for controlling this condition include packing with laparotomy pads, the use of sterile thumbtacks,1 ligation of the internal iliac vessel,2 and selective arterial embolization.3 These methods are generally ineffective. Recently, several other methods for controlling presacral bleeding have been reported, such as occlusion of the wound with rectus muscle fragment welding,4 oppression with sterile normal saline bags,5 balloon tamponade,6 and the use of endoscopic staples.7 However, these measures fail to arrest the bleeding in some patients, resulting in massive hemorrhage and even death.

关键词： presacral venous plexus massive hemorrhage bipolar coagulation hemostasis

A Time-Domain Numerical Simulation for Free Motion Responses of Two Ships Advancing in Head Waves

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China Ocean Engineering 2024年第3期38卷 519-530页

作者： PAN Su-yong cheng yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The constant panel method within the framework of potential flow theory in the time domain is developed for solving the hydrodynamic interactions between two parallel ships with forward *** solving problems within a time domain framework,the free water surface needs to simultaneously satisfy both the kinematic and dynamic boundary conditions of the free water *** provides conditions for adding artificial damping *** the Runge−Kutta method to solve equations related to *** upwind differential scheme is used in the present method to deal with the convection terms on the free surface to prevent waves *** the comparison with the available experimental data and other numerical methods,the present method is proved to have good mesh convergence,and satisfactory results can be *** constant panel method is applied to calculate the hydrodynamic interaction responses of two parallel ships advancing in head *** simulations are conducted on the effects of forward speed,different longitudinal and lateral distances on the motion response of two modified Wigley ships in head *** further investigations are conducted on the effects of different ship types on the motion response.

关键词： ship motions time domain simulation forward speed different distances wave loads

Variable projection algorithms with sparse constraint for separable nonlinear models

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Control Theory and Technology 2024年第1期22卷 135-146页

作者： hui-Lang Xu Guang-yong Chen Si-Qing cheng Min Gan Jing Chen College of Computer and Data Science Fuzhou UniversityFuzhou350116FujianChina Fujian Key Laboratory of Network Computing and Intelligent Information Processing Fuzhou UniversityFuzhou350116FujianChina Key Laboratory of Intelligent Metro of Universities in Fujian Fuzhou UniversityFuzhou350116FujianChina Engineering Research Center of Big Data Intelligence Ministry of EducationFuzhou UniversityFuzhou350116FujianChina School of Science Jiangnan UniversityWuxi214122JiangsuChina

Separable nonlinear models are widely used in various fields such as time series analysis, system modeling, and machine learning, due to their flexible structures and ability to capture nonlinear behavior of data. However, identifying the parameters of these models is challenging, especially when sparse models with better interpretability are desired by practitioners. Previous theoretical and practical studies have shown that variable projection (VP) is an efficient method for identifying separable nonlinear models, but these are based on \(L_2\) penalty of model parameters, which cannot be directly extended to deal with sparse constraint. Based on the exploration of the structural characteristics of separable models, this paper proposes gradient-based and trust-region-based variable projection algorithms, which mainly solve two key problems: how to eliminate linear parameters under sparse constraint;and how to deal with the coupling relationship between linear and nonlinear parameters in the model. Finally, numerical experiments on synthetic data and real time series data are conducted to verify the effectiveness of the proposed algorithms.

关键词： Variable projection(VP) Non-smooth constraint Separable nonlinear models

Interfacial friction effects on sealing performances of elastomer packer

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Petroleum Science 2024年第3期21卷 2037-2047页

作者： Peng-cheng Wang Ming-hui Chen Jim Jenkinson yong-Xin Song Li Sun Department of Mechanical Engineering University of HoustonHoustonTX77024USA Guren Nanomaterials Suzhou215127JiangsuChina Department of Marine Engineering Dalian Maritime UniversityDalian116026LiaoningChina

Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic *** practice sealing performances of such plugs are normally evaluated through pressure tests,and in numerical simulation studies,maximum contact stress,average contact stress and contact length data are used to determine sealing quality between a packer and *** previous studies,the impact of friction forces on sealing performance is often *** work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing *** first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac *** we compared analytical calculation results with Finite Element Analysis simulation using a simplified tubular geometry and showed the significant influences on interfacial friction on elastomer packer stress distribution,deformation,and contact stress after *** the demonstration of validity of FEA method,we conducted systematic numerical simulation studies to show how the interfacial friction coefficients can affect the maximum contact stress,average contact stress,contact stress distribution,and maximum mises stress for an actual packer used in plug *** addition,we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial *** study underscores the critical role that friction forces play in Frac plug performance and provides a new dimension for optimizing packer design by controlling interfacial interactions at the packer contact surfaces.

关键词： Elastomer seal Friction Sealing performance Contact stress

Optimization of the co-closing law of guide vanes and blades for bulb turbines based on CFD

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Journal of Hydrodynamics 2024年第2期36卷 363-377页

作者： hui Liu Yun-fa Lin yong-guang cheng Song Xue Mao-jia Tang Jian Zhang Jia-yi Fan State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Dongfang Electric Machinery Co. Ltd.Deyang618000China

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations,and determining appropriate closing laws of guide vanes(GVs)and runner blades(RBs)for this process is of *** this study,we proposed a procedure to optimize the co-closing law of GVs and RBs by using computational fluid dynamics(CFD),combined with the design of experiment(DOE)method,approximation model,and genetic optimization *** sensitivity of closing law parameters on the histories of head,speed,and thrust was analyzed,and a two-stage GVs’closing law associating with a linear RBs’closing law was *** results show that GVs dominate the transient characteristics by controlling the change of *** GVs’first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure;slowing GVs’second-stage closing speed is conducive to controlling the maximum reverse axial *** directly affect the runner *** RBs’closing speed can further reduce the rotational speed and the maximum reverse axial *** safety margin of each control parameter,flow patterns,and pressure pulsations of a practical hydropower station were all improved after optimization,demonstrating the effectiveness of this method.

关键词： Bulb turbine load rejection transient process double regulation closing law optimization computational fluid dynamics(CFD)

Weak Merging Scenario of CLASH Cluster A209

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Research in Astronomy and Astrophysics 2024年第4期24卷 174-182页

作者： Wen-cheng Feng Heng Yu Hai-hui Zhao Xiao-Lan Hou Shu-Mei Jia cheng-Kui Li Yu-Lin cheng Paolo Tozzi Ming Sun yong Chen Department of Physics and Institute of Theoretical Physics Nanjing Normal UniversityNanjing 210023China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Department of Astronomy Beijing Normal UniversityBeijing 100875China Department of Astronomy Yunnan UniversityKunming 650091China INAF—Osservatorio Astrofisico di Arcetri Largo E.Fermi50122 FirenzeItaly Department of Astronomy University of VirginiaP.O.Box 400325CharlottesvilleVA 22904-4325USA

We study the structural and dynamical properties of A209 based on Chandra and XMM-Newton *** obtain detailed temperature,pressure,and entropy maps with the contour binning method,and find a hot region in the NW *** X-ray brightness residual map and corresponding temperature profiles reveal a possible shock front in the NW direction and a cold front feature in the SE *** with the galaxy luminosity density map we propose a weak merger scenario.A young sub-cluster passing from the SE to NW direction could explain the optical subpeak,the intracluster medium temperature map,the X-ray surface brightness excess,and the X-ray peak offset together.

关键词： X rays:galaxies:clusters galaxies:clusters:intracluster medium galaxies:clusters:Abell 209

Hydrophobic long-chain two-dimensional perovskite scintillators for underwater X-ray imaging

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Rare Metals 2024年第1期43卷 175-185页

作者： Jin-Xiao Zheng Zi-An Zhou Tiao Feng hui Li cheng-Hua Sun NüWang Yang Tian yong Zhao Shu-Yun Zhou Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Laboratory of Bioinspired Smart Interfacial Science and Technology of the Ministry of Education Beijing Key Laboratory of Bioinspired Energy Materials and DevicesSchool of ChemistryBeijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijing 100191China Department of Engineering Physics Tsinghua University and Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China e-mail:yangt@***

The underwater X-ray imaging technology development is significant to subaqueous target reconnaissance/detection/identification, subfluvial archaeology,submerged resource exploration, etc. As the core of X-ray imaging detection, the scintillator has been plagued by inherent moisture absorption and decomposition, and strict requirements for seamless packaging and ***, we designed a manganese-doped two-dimensional(2D) perovskite scintillator modified by hydrophobic longchain organic amine through the combination of component and doping engineering. The modified perovskites show high water repellency that can be used as an underwater X-ray scintillator. X-ray images of aquatic organisms or other objects with a high spatial resolution of10 lp·mm^(-1) at a big view field(32 mm × 32 mm) were obtained by scintillation screen. This hydrophobic perovskite scintillator based on molecular design is of great promise in underwater X-ray nondestructive testing technology development.

关键词： Two-dimensional perovskite Hydrophobic Scintillators Underwater X-ray imaging Underwater nondestructive testing technology

In vivo label-free measurement of blood flow velocity symmetry based on dual line scanning third-harmonic generation microscopy excited at the 1700 nm window

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Journal of Innovative Optical Health Sciences 2024年第1期17卷 61-68页

作者： hui cheng Jincheng Zhong Ping Qiu Ke Wang Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen 518060 P.R.China

Measurement of bloodflow velocity is key to understanding physiology and pathology in *** most measurements are performed at the middle of the blood vessel,little research has been done on characterizing the instantaneous bloodflow velocity *** is mainly due to the lack of measurement technology with high spatial and temporal ***,we tackle this problem with our recently developed dual-wavelength line-scan third-harmonic generation(THG)imaging *** acquisition of dual-wavelength THG line-scanning signals enables measurement of bloodflow velocities at two radially symmetric positions in both venules and arterioles in mouse brain in *** results clearly show that the instantaneous bloodflow velocity is not symmetric under general conditions.

关键词： 1700 nm-Window third-harmonic generation imaging blood flow velocity

Efficient piezo-assisted near-infrared-light-driven Cr（Ⅵ） reduction over Bi2S3 nanowires transformed from ultrathin Bi2WO6 nanosheets

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Rare Metals 2024年第9期43卷 4333-4343页

作者： Qiang Zhang Yuan-Hao cheng Wei Liu hui-Nan Che Yan-hui Ao Key Laboratory of Integrated Regulation and Resource Development On Shallow Lakes Ministry of Education College of Environment Hohai University

The utilization of piezo-photocatalytic technol ogy for environmental remediation under full spectrum solar light is promising but still ***,one dimensional Bi2S3nanowires,which can utilize both mechanical energy and near-infrared （NIR） light to remov hexavalent chromium (Cr （VI）) efficiently,were synthe sized by a restrained growth *** reaction rat constants of Cr （VI） reduction in piezo-photocatalyti process under NIR （800–2500 nm） reached 0.334 min-1which were 3.2 and 12.4 times as that of single piezo and photocatalytic *** formation of polarized electri fields and one-dimensional structure allow ultrafast sepa ration of charge carriers,thereby promoting the catalyti ***,due to the strong penetrability o NIR light,the piezo-photocatalysis performance in turbid solutions under NIR light (0.188 min-1) was even com parable to that under visible light (0.186 min-1).Thi study provides a new concept on the development of piezo photocatalytic technology for environmental remediation by utilization of NIR light and natural mechanical energy.

关键词： Bi2S3 nanowires Cr(VI) NIR light Piezo-photocatalysis