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Symmetries and conservation laws associated with a hyperbolic mean curvature flow

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Applied Mathematics(A Journal of Chinese Universities) 2022年第4期37卷 583-597页

作者： gao ben YIN Qing-lian College of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

Under investigation in this paper is a hyperbolic mean curvature flow for convex evolving ***,in view of Lie group analysis,infinitesimal generators,symmetry groups and an optimal system of symmetries of the considered hyperbolic mean curvature flow are *** the same time,some group invariant solutions are computed through reduced *** particular,we construct explicit solutions by applying the power series ***,the convergence of the solutions of power series is ***,conservation laws of the hyperbolic mean curvature flow are established via Ibragimov's approach.

关键词： hyperbolic mean curvature flow symmetries power series solutions conservation laws

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新时代高职院校学生劳动素养评价机制研究

教育教学论坛 2024年第5期 185-188页

作者：高本才朱晓坤天津职业大学公共管理学院天津300410 天津职业大学党委学生工作部天津300410

当前在“五育”中劳动教育是最晚纳入党的教育方针的,而劳动教育又恰恰是能够促进德智体美有效发展的关键一环。对劳动教育评价机制的研究和实施是劳动教育脱虚入实的关键一招。首先梳理了劳动教育评价机制的相关研究背景、基本概念及... 详细信息

当前在“五育”中劳动教育是最晚纳入党的教育方针的,而劳动教育又恰恰是能够促进德智体美有效发展的关键一环。对劳动教育评价机制的研究和实施是劳动教育脱虚入实的关键一招。首先梳理了劳动教育评价机制的相关研究背景、基本概念及研究现状,其次从劳动教育的现实意义、高职学生劳动教育的独特性、劳动教育的载体和层次、构建以学生为中心的评价机制及评价机制构成要素介绍等方面阐述了劳动教育评价机制的构建过程。对劳动素养培养载体层次和劳动素养评价体系维度进行了较为深入的研究。

关键词：劳动教育劳动素养评价机制

Subsurface Damage in Scratch Testing of Potassium Dihydrogen Phosphate Crystal

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Chinese Journal of Mechanical Engineering 2009年第1期22卷 15-20页

作者： WANG ben WU Dongjiang gao Hang KANG Renke GUO Dongming Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of Technology Dalian 116024 China

Potassium dihydrogen phosphate （KDP） is an important electro-optic crystal, often used for frequency conversion and Pockels cells in large aperture laser systems. To investigate the influence of anisotropy to the depth of subsurface damage and the profiles of cracks in subsurface of KDP crystal, an experimental study was made to obtain the form of subsurface damage produced by scratches on KDP crystal in [100], [120] and [110] crystal directions on （001） crystal plane. The results indicated that there were great differences between depth and crack shape in different directions. For many slip planes in KDP, the plastic deformation and cracks generated under pressure in the subsurface were complex. Fluctuations of subsurface damage depth at transition point were attributed to the deformation of the surface which consumed more energy when the surface deformation changed from the mixed region of brittle and plastic to the complete brittle region along the scratch. Also, the process of subsurface damage from shallow to deep, from dislocation to big crack in KDP crystal with the increase of radial force and etch pit on different crystal plane were obtained. Because crystallographic orientation and processing orientation was different, etching pits on （100） crystal plane were quadrilateral while on （110） plane and （120） plane were trapezoidal and triangular, respectively.

关键词： potassium dihydrogen phosphate (KDP) crystal scratch subsurface damage

水性反射隔热型涂料的制备及性能影响因素探究

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中国涂料 2024年第2期39卷 32-37页

作者：高本正王娜齐舵于帅沈阳化工大学辽宁省特种功能材料合成与制备重点实验室沈阳110142 沈阳先进涂层材料产业技术研究院沈阳110300 辽宁顺风新材料科技有限公司沈阳110326

研究了反射隔热涂料中重要组分对其性能的影响规律。以纯丙乳胶作为成膜物,空心玻璃微珠和金红石型二氧化钛作为功能填料,在基本配方体系基础上,通过单一变量控制法研究了空心玻璃微珠、金红石型二氧化钛的尺寸及添加量等因素对反射隔... 详细信息

研究了反射隔热涂料中重要组分对其性能的影响规律。以纯丙乳胶作为成膜物,空心玻璃微珠和金红石型二氧化钛作为功能填料,在基本配方体系基础上,通过单一变量控制法研究了空心玻璃微珠、金红石型二氧化钛的尺寸及添加量等因素对反射隔热涂料透水及耐沾污性、太阳光反射性能和隔热性能的影响规律,并制备得到综合性能优异的水性反射隔热涂料。研究结果表明,反射隔热填料不仅影响涂层的太阳光反射和隔热性能,对于涂层的耐水和耐沾污性也有显著影响。

关键词：反射隔热涂料空心玻璃微珠金红石型二氧化钛太阳光反射比

Spin Thermoelectric Effects in a Three-Terminal Double-Dot Interferometer

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Communications in Theoretical Physics 2018年第11期69卷 625-632页

作者： Feng Liang ben-Ling gao Guang Song Yu Gu Department of Applied Physics Huaiyin Institute of Technology Department of Physics and Siyuan Laboratory Jinan University

We theoretically investigate the thermoelectric properties of a three-terminal double-dot interferometer with Rashba spin-orbit interaction. It is found that with some temperature distributions a thermal spin current can even be produced without the help of magnetic flux and by tuning the spin interference effect in the system, a pure spin or fully spin-polarized current can be driven by temperature differences. For the cases that two of the terminals are held at the same temperature, the charge (spin) thermopower and the charge (spin) figure of merit are defined and calculated in the linear response regime. With some choices of the system parameters the calculated spin and charge thermopowers are of the same order of magnitude and the charge figure of merit can exceed 1.

关键词： thermoelectric effects thermal spin current Rashba spin-orbit interaction,interferometer nonequilibrium Green's function method

Value of the controlling nutritional status score and psoas muscle thickness per height in predicting prognosis in liver transplantation

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World Journal of Clinical Cases 2021年第35期9卷 10871-10883页

作者： Xing Dai ben gao Xin-Xin Zhang Jiang Li Wen-Tao Jiang Department of Liver Transplant The First Central College of Tianjin Medical UniversityTianjin 300110China Department of Endocrinology Tianjin Medical University Chu Hsien-I Memorial HospitalTianjin 300134China Department of Liver Transplant Tianjin First Central HospitalTianjin 300110China

BACKGROUND Patients with end-stage liver disease usually have varying degrees of malnutrition,and severe malnutrition may affect the prognosis of patients after liver transplantation(LT).However,there is no recommended standard for the nutrition assessment of patients waiting for LT,and it is unknown whether malnutrition has an impact on the occurrence of postoperative *** The study aim was to investigate the value of the controlling nutritional status(CONUT)score and psoas muscle thickness per height(PMTH)in predicting prognosis in *** We retrospectively analyzed the clinical data of 313 patients who underwent classic orthotopic LT from January 2016 to December 2018 in Tianjin First Central Hospital affiliated with Tianjin Medical *** CONUT score is derived from the preoperative serum albumin and total cholesterol levels,and total lymphocyte *** were divided into low(≤4),medium(5–8),and high(9–12)CONUT score groups perioperative characteristics,Clavien-Dindo grade III/IV/V postoperative complications,graft loss and infection,and cumulative postoperative survival in the three groups were compared 3 mo after *** was calculated as the ratio of the transverse thickness of the psoas muscle in the umbilical plane to the height of the *** cutoff values of receiver operating characteristic curves were determined separately for men and *** values were 14.1 cm/m2 for women and 17.9 cm/m2 for *** patients were then divided into low and high PMTH groups by the cutoff *** comparison of data between the two groups was the same as *** Patients with medium and high CONUT scores had lower preoperative serum hemoglobin,more intraoperative red blood cell(RBC)transfusions,longer postoperative intensive care unit stay and hospital stays,higher 7 and 14 preoperative-day serum bilirubin levels,and a higher incidence of postoperative grade III/IV complications and infections than patients with low CONUT scor

关键词： Liver transplantation Controlling nutritional status score Psoas muscle thickness per height Nutrition assessment Complications Prognosis

A hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction

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Control Theory and Technology 2024年第3期22卷 394-405页

作者： Chuanxiang gao Xinyi Wang Xi Chen ben M.Chen Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongShatinNTChina

Unmanned aerial vehicles(UAVs)are emerging as a powerful tool for inspections and repair works in large-scale and unstructured 3D infrastructures,but current approaches take a long time to cover the entire *** using UAVs for inspections and repair works puts forward a requirement of improving time efficiency in large-scale and cluster *** paper presents a hierarchical multi-UAV cooperative framework for infrastructure inspection and reconstruction to balance the workload and reduce the overall task completion *** proposed framework consists of two stages,the exploration stage and the exploitation stage,resolving the task in a sequential *** the exploration stage,the density map is developed to update global and local information for dynamic load-balanced area partition based on reconstructability and relative positions of UAVs,and the Voronoi-based planner is used to enable the UAVs to reach their best *** obtaining the global map,viewpoints are generated and divided while taking into account the battery capacity of each ***,a shortest path planning method is used to minimize the total traveling cost of these viewpoints for obtaining a high-quality *** experiments are conducted in both a simulated and real environment to show the time efficiency,robustness,and effectiveness of the proposed ***,the whole system is implemented in real applications.

关键词： Multi-UAV Coverage path planning Infrastructure inspection and reconstruction

The mechanism of microwave rock breaking and its potential application to rock-breaking technology in drilling

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Petroleum Science 2022年第3期19卷 1110-1124页

作者： Ming-Zhong gao ben-gao Yang Jing Xie Si-Qi Ye Jun-Jun Liu Yi-Ting Liu Rui-Feng Tang Hai-Chun Hao Xuan Wang Xiang-Yue Wen Xue-Min Zhou Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization College of Civil and Transportation EngineeringShenzhen UniversityShenzhenGuangdong518060China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource&HydropowerSichuan UniversityChengduSichuan610065China

The exploration and development of oil and gas resources have shifted from shallow to deep and *** difficulty of rock breaking has also increased,introducing new challenges to traditional rock-breaking ***,there is an urgent need to develop new rock-breaking technologies to improve the development efficiency of deep oil and gas ***,this study focused on the new microwave rock-breaking technology and conducted experimental and numerical simulation research on typical deep,hard rock *** research results showed that granite in the microwave field exhibited high-temperature melting and fracture,and the highest temperature could reach 550°*** the irradiation of circulating microwaves,a minimum irradiation time threshold of 3 min was needed to cause irreversible damage to the *** numerical simulation results showed that the interaction of thermal stress and in situ stress would cause the inside of the rock stratum to separate into a disturbed deterioration area,disturbed unloading area and initial stress *** results are expected to provide the necessary technical guidance and theoretical support for the research and development of high-efficiency rock-breaking drilling for deep hard rock.

关键词： Microwave Well drilling High efficiency Granite

Exploration of weakening mechanism of uniaxial compressive strength of deep sandstone under microwave irradiation

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Journal of Central South University 2022年第2期29卷 611-623页

作者： YANG ben-gao gao Ming-zhong XIE Jing LIU Jun-jun WANG Fei WANG Ming-yao WANG Xuan WEN Xiang-yue YANG Zhao-ying State Key Laboratory of Hydraulics and Mountain River Engineering College ofWater Resource&HydropowerSichuan UniversityChengdu 610065China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green EnergyCollege of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

Traditional mechanical rock breaking method is labor-intensive and low-efficient,which restrictes the development of deep resources and deep *** a new rock-breakage technology,microwave irradiation is expected to overcome these *** study examines the failure characteristics,weakening law,and breakdown mechanism of deep sandstone(depth=1050 m)samples in a microwave *** macroscopic and microscopic properties were determined via mechanical tests,mesoscopic tests,and numerical *** application at 1000 W for 60 s reduced the uniaxial compressive strength of the sandstone by 50%.Thermal stress of the sandstone was enhanced by uneven expansion of minerals at the ***,the melting of some minerals in the high-temperature environment changed the pore structure,sharply reducing the macroscopic *** temperature remained high in the lower midsection of the sample,and the stress was concentrated at the bottom of the sample and along its *** results are expected to improve the efficiency of deep rock breaking,provide theoretical and technical support for similar rock-breakage projects,and accelerate advances in deep-Earth science.

关键词： microwave sandstone uniaxial compressive strength weakening mechanism