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Journal of Systems Science & Complexity 2021年第2期34卷 552-571页

作者： wang Fang wang jian-mei wang Kun ZONG Qun HUA Changchun School of Science Yanshan UniversityQinhuangdao 066004China School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China School of Electrical and Engineering Yanshan UniversityQinhuangdao 066004China

A disturbance observer(DOB)based-backstepping sliding mode control scheme is discussed for a class of semi-strict nonlinear system with unknown parameters and mismatched uncertainty.Firstly,adaptive technique and DOB are respectively applied to tackle the unknown parameters and mismatched uncertainty,where the DOB can effectively alleviate the chattering problem of sliding mode control(SMC).Then,exponential sliding mode surface is proposed to improve the convergence rate of the sliding mode state.The‘explosion of complexity’problem inherent in conventional backstepping control is overcome by designing the novel first-order filter.The stability of the closed-loop system is analyzed in the framework of Lyapunov stability theory,in which the tracking error converges to an arbitrarily small neighborhood around zero(ASNZ).At last,two examples are given to illustrate the effectiveness of the proposed control strategy.

关键词： Adaptive law DOB filter semi-strict nonlinear system SMC

Fatigue Damage Mechanism of Oil Film Bearing Sleeve

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Journal of Iron and Steel Research(International) 2007年第1期14卷 60-63,68页

作者： HUANG Qing-xue wang jian-mei MA Li-feng ZHAO Chun-jiang School of Mechanical and Electrical Engineering Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China School of Mechanical Design and Automation Taiyuan University of Technology Taiyuan 030024 Shanxi China

With the rapid development of the steel industry, to keep pace with the current trend of high speed, continuous, and large-scale production that focuses on automation and high levels of efficiency, many state-owned steel companies are being equipped with oil film bearings. Through long-term on-spot inspection and research on the fatigue failure of oil film bearing, three segments of annulated fatigue breakage were found axially along the inner surface of the bearing sleeve. In order to elucidate the reason for the three-segment annulated damage under rolling load, numerical boundary element method was adopted to analyze the contact behaviors between the sleeve and rollneck. Failure mechanism was discussed in detail, the distributions of contact stress were analyzed, and the service lives of the sleeve for different positions on the inner surface were quantitatively described, which provided an effective means to decrease wear and adhesive damage of the sleeve and to increase the load capacity of oil film bearing and its service life as well.

关键词： oil film bearing fatigue failure analysis contact problem bearing life

Mechanical Properties of New Type Negative Offset Structure During Shearing Process of Heavy Steel Plate

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Journal of Iron and Steel Research(International) 2007年第5期14卷 31-35页

作者： MA Li-feng HUANG Qing-xue wang jian-mei YANG jian-wei LI Ying LI Jin-bao School of Material Science and Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi China School of Mechanical Engineering Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China Computer Institute Defense Chemical Command Engineering College of PLA Beijing 100000 China

According to the revised Cailikefu＇s rolling shear force formula, motion path equation of spatial seven-bar path was built, and a mechanical model, with the new structural feature of negative offset, was thus successfully established for 2 800 mm heavy shear of some iron and steel company. Shear and bar forces of steel plate, before and after the adoption of negative offset structure, were analyzed, as well as horizontal force component of mechanism that influences pure rolling shear and back-wall push force that keeps blade clearance. It was found that the back-wall push force keeps large even at the time that the maximum rolling shear was obtained; meanwhile, back-wall push force is the most approximate to side forces when 60--100 mm of offset was adopted. Both theoretical results and onsite shear quality show that the negative offset plays an important role in ensuring the stability of pure rolling shear and keeping blade clearance constant.

关键词： rolling shear mechanical model mechanical property blade clearance negative offset shear quality

Simulation of Strip Rolling Using Elastoplastic Contact BEM With Friction

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Journal of Iron and Steel Research(International) 2008年第1期15卷 34-38页

作者： LI Yu-gui HUANG Qing-xue SHEN Guang-xian XIAO Hong PANG Si-qin wang jian-mei College of Material and Science Engineering Taiyuan University of Science and Technology Taiyuan 030024 Shanxi China College of Machinery Engineering Yanshan University Qinhuangdao 066004 Hebei China College of Machinery and Vehicle Engineering Beiiing Institute of Technology Beijing 100081 China

With rollers as elastic bodies and workpieces as elastoplastic bodies,the rolling problem can be viewed as a friction elastic-plastic contact problem.With fewer assumptions in the simulation of strip-rolling process,a boundary element method（BEM）for two-dimensional elastoplastic finite strain and finite deformation analysis of contact problems with friction was presented.All the equations for contact problems,which include multi-nonlinearities,were obtained.Incremental and iterative procedures were used to find contact pressure and friction stress.Moreover,initial strain rate algorithm and work-hardening material behavior can be assumed in the plastic analysis.Several examples were presented,and the results of contact pressure and friction stress were in excellent agreement with those of analysis.

关键词： boundary element method contact problem elastoplastic finite deformation rolling

A case study of changing motivation in foreign language learning

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Sino-US English Teaching 2010年第6期7卷 13-17,41页

作者： wang jian-mei School of Foreign Languages Chongqing University of Technology Chongqing 400050 China

Effects of Nitrogen Application Level on Rice Nutrient Uptake and Ammonia Volatilization

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Rice science 2013年第2期20卷 139-147页

作者： YU Qiao-gang YE Jing YANG Shao-na FU jian-rong MA Jun-wei SUN Wan-chun jianG Li-na wang Qiang wang jian-mei Institute of Environment Resource and Soil Fertilizer Zhejiang Academy of Agriculture Science

The effects of different nitrogen application levels on nutrient uptake and ammonia volatilization were studied with the rice cultivar Zheyou 12 as a material.The accumulative amounts of nitrogen,phosphorus and potassium in rice plants across all growth stages showed a trend to increase with increasing nitrogen application levels from 0 to 270 kg/hm 2,but decreased at nitrogen application levels exceeding 270 kg/hm 2.Moreover,the accumulative uptake of nitrogen,phosphorus and potassium by the rice plants was increased by application of organic manure in combination with 150 kg/hm 2 nitrogen.The nitrogen uptake was high during the jointing to heading stages.Correlation analysis showed that rice yield was positively correlated with the accumulative uptake of nitrogen,phosphorus and potassium by the rice plants.The highest correlation coefficient observed was between the amount of nitrogen uptake and rice yield.The rate and accumulative amounts of ammonia volatilization increased with increasing nitrogen fertilizer application level.Compared with other stages,the rate and accumulative amount of ammonia volatilization were higher after base fertilizer application.The ammonia volatilization rates in response to the nitrogen application levels of 270 kg/hm 2 and 330 kg/hm 2 were much higher than those in the other treatments.The loss of nitrogen through ammonia volatilization accounted for 23.9% of the total applied nitrogen at the nitrogen application level of 330 kg/hm 2.

关键词： rice nitrogen nutrient uptake ammonia volatilization

miR-34a-5p靶向调控MMP-9对类风湿关节炎大鼠氧化应激及滑膜细胞分化的作用机制

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中国老年学杂志 2024年第6期44卷 1494-1498页

作者：王建梅强树华高虹刘丹丹霍晶临汾市中心医院风湿免疫科山西临汾041000

目的探究微小RNA34a5p(miR-34a-5p)靶向调控基质金属蛋白酶(MMP)-9对类风湿关节炎(RA)大鼠氧化应激及滑膜细胞分化的作用机制。方法选取60只SPF级SD雄性大鼠,随机分为正常(A)组,模型(B)组,miR-NC(C)组,miR-34a-5p mimic(D)组,MMP-9抑制... 详细信息

目的探究微小RNA34a5p(miR-34a-5p)靶向调控基质金属蛋白酶(MMP)-9对类风湿关节炎(RA)大鼠氧化应激及滑膜细胞分化的作用机制。方法选取60只SPF级SD雄性大鼠,随机分为正常(A)组,模型(B)组,miR-NC(C)组,miR-34a-5p mimic(D)组,MMP-9抑制剂(E)组,miR-34a-5p mimic+MMP-9抑制剂(F)组,每组10只,对B、C、D、E、F组采用弗氏完全佐剂法进行RA建模,A组不建立该模型,建模成功后,对C组给予尾静脉注射0.5 ml 1×10^(5)/ml的miR-NC,对D组给予尾静脉注射0.5 ml 1×10^(5)/ml的miR-34a-5p mimic,对E组给予尾静脉注射30 mg/kg的盐酸多西环素,对F组给予miR-34a-5p mimic联合盐酸多西环素,A、B组同期给予尾静脉注射同体积生理盐水,苏木素-伊红(HE)染色检测大鼠滑膜组织病理形态,实时荧光定量聚合酶链反应(Real-time PCR)法检测大鼠滑膜组织中miR-34a-5p、MMP-9 mRNA相对表达,黄嘌呤氧化酶法和硫代巴比妥酸法检测血清中氧化应激相关指标,免疫荧光法检测大鼠滑膜组织中滑膜细胞分化相关指标。结果A组滑膜组织细胞结构正常且排列整齐,未见关节腔渗出、水肿、充血及炎性细胞浸润现象,B、C组出现弥漫性滑膜细胞和纤维组织增生,并可见大量血管翳形成及大量炎性细胞浸润现象,D、E、F组可见滑膜细胞轻度增生及少量炎性细胞浸润和新生毛细血管形成,水肿、充血情况明显改善;与A组比较,B、C组滑膜组织中miR-34a-5p mRNA表达、血清中超氧化物歧化酶(SOD)含量显著降低,MMP-9 mRNA表达、血清中丙二醛(MDA)含量、降钙素受体(CTR)蛋白表达明显升高(P0.05),与C组相比,D、E、F组miR-34a-5 mRNA表达、SOD含量显著升高,MMP-9 mRNA表达、MDA含量、CTR蛋白表达显著降低(P0.05),而F组较E组变化显著(P<0.05);miR-34a-5p与MMP-9呈负相关(r=-0.952,P<0.001)。结论促进miR-34a-5p可对RA起到治疗作用,其可有效抑制氧化应激,并抑制滑膜细胞向破骨细胞分化,其机制可能与靶向调控MMP-9有关。

关键词： miR-34a-5p 类风湿关节炎基质金属蛋白酶(MMP)-9 氧化应激滑膜细胞分化

Metadherin promotes stem cell phenotypes and correlated with immune infiltration in hepatocellular carcinoma

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World Journal of Gastroenterology 2024年第8期30卷 901-918页

作者： Yi-Ying wang mei-mei Shen jian Gao Department of Gastroenterology The Second Affiliated Hospital of Chongqing Medical UniversityChongqing 400010China Department of Gastroenterology and Hepatology The Second Affiliated Hospital of Chongqing Medical UniversityChongqing 400010China

BACKGROUND Metadherin(MTDH)is a key oncogene in most cancer types,including hepato-cellular carcinoma(HCC).Notably,MTDH does not affect the stemness pheno-type or immune infiltration of HCC.AIM To explore the role of MTDH on stemness and immune infiltration in HCC.METHODS MTDH expression in HCC tissues was detected using TCGA and GEO databases.Immunohistochemistry was used to analyze the tissue samples.MTDH was stably knocked down or overexpressed by lentiviral transfection in the two HCC cell lines.The invasion and migration abilities of HCC cells were evaluated using Matrigel invasion and wound healing assays.Next,we obtained liver cancer stem cells from the spheroids by culturing them in a serum-free medium.Gene expression was determined by western blotting and quantitative reverse transcri-ption PCR.Flow cytometry,immunofluorescence,and tumor sphere formation assays were used to characterize stem-like cells.The effects of MTDH inhibition on tumor growth were evaluated in vivo.The correlation of MTDH with immune cells,immunomodulators,and chemokines was analyzed using ssGSEA and TISIDB databases.RESULTS HCC tissues expressed higher levels of MTDH than normal liver tissues.High MTDH expression was associated with a poor prognosis.HCC cells overex-pressing MTDH exhibited stronger invasion and migration abilities,exhibited a stem cell-like phenotype,and formed spheres;however,MTDH inhibition attenuated these effects.MTDH inhibition suppressed HCC progression and CD133 expression in vivo.MTDH was positively correlated with immature dendritic,T helper 2 cells,central memory CD8^(+)T,memory B,activated dendritic,natural killer(NK)T,NK,activated CD4^(+)T,and central memory CD4^(+)T cells.MTDH was negatively correlated with activated CD8^(+)T cells,eosinophils,activated B cells,monocytes,macrophages,and mast cells.A positive correlation was observed between the MTDH level and CXCL2 expression,whereas a negative correlation was observed between the MTDH level and CX3CL1 and CXCL12 expression.CONCLUSION High levels of M

关键词： Metadherin Hepatocellular carcinoma Cancer stem cells Immune infiltration

遗产活化视角下长城国家文化公园(秦皇岛段)景观营建策略研究

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河北地质大学学报 2024年第2期47卷 117-121页

作者：王建梅胡晓宾于宝李兴王娜解雨河北科技师范学院园艺科技学院河北秦皇岛066004 矿冶科技集团有限公司北京100160

从长城国家文化公园(秦皇岛段)建设目标出发,对秦皇岛市长城资源现状、分布及特点进行调研,分析秦皇岛市长城资源现有情况及其开发不足之处,指出在遗产活化视角下,秦皇岛市长城国家文化公园建设应以遗产活化为视角,集合遗产保护、景观... 详细信息

从长城国家文化公园(秦皇岛段)建设目标出发,对秦皇岛市长城资源现状、分布及特点进行调研,分析秦皇岛市长城资源现有情况及其开发不足之处,指出在遗产活化视角下,秦皇岛市长城国家文化公园建设应以遗产活化为视角,集合遗产保护、景观展示与活化、居民娱乐与旅游开发为一体的综合性工程。并提出在区域化背景下,长城国家文化公园建设要以资源为主,坚持遗产保护与合理规划并行,充分发挥地方特色,打造“保护、发展、传承、共生”为一体的景观体系构,为长城国家文化公园规划实施提供实践参考。

关键词：遗产保护秦皇岛国家文化公园长城景观营建

Cage-confinement synthesis of MoC nanoclusers as efficient sulfiphilic and lithiophilic regulator for superior Li–S batteries

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Rare Metals 2024年第2期43卷 624-634页

作者： Xing-Yuan Zhang mei-Na Lei Shan Tian jian-Gan wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene(NPU)Xi’an710072China

High-energy-density Li-S batteries are subjected to serious sulfur deactivation and short cycle lifetime caused by undesirable polysulfide shuttle effect and frantic lithium dendrite formation.In this work,a controllable cage-confinement strategy to fabricate molybdenum carbide(MoC)nanoclusters as a high-efficient sulfiphilic and lithiophilic regulator to mitigate the formidable issues of Li-S batteries is demonstrated.The sub-2 nm MoC nanoclusters not only guarantee robust chemisorption and fast electrocatalytic conversion of polysulfides to enhance the sulfur electrochemistry,but also homogenize Li^(+) flux to suppress the lithium dendrite growth.As a consequence,the MoC-modified separator endows the batteries with boosted reaction kinetics,promoted sulfur utilization,and improved cycling stability.A reversible capacity of 701 mAh·g^(−1) at a high rate of 5.0C and a small decay rate of 0.076%per cycle at 1.0C over 600 cycles are achieved.This study offers a rational route for design and synthesis of bifunctional nanoclusers with both sulfiphilicity and lithiophilicity for high-performance Li-S batteries.

关键词： Li-S batteries Nanocluster Electrocatalyst Polysulfide shuttle Li dendrites