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Effects of process parameters on mechanical properties of abrasive-assisted electroformed nickel

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Chinese Journal of Aeronautics 2016年第4期29卷 1096-1102页

作者： ren jianhua Zhu Zengwei Zhu Di College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

A cathode mandrel with translational and rotational motion, which was supposed to obtain uniform friction effect on surface, was employed in abrasive-assisted electroforming for revolving parts with complex profile. The effects of current density, translational speed and rotational speed on the deposit properties were studied by orthogonal test. The tensile strength, elongation and micro hardness value were measured to find out how the factors affected the properties. The optimized results show that changes of current density affect the tensile strength of nickel layer most, while translational speed has the most remarkable influences on both elongation and micro hardness. The low rotational speed affects the properties least. In this experiment, a smooth nickel layer with tensile strength 581 MPa, elongation 17% and micro hardness 248HV is obtained by the orthogonal test. (C) 2016 Chinese Society of Aeronautics and Astronautics. Production and hosting by Elsevier Ltd.

关键词： Abrasive Cathode compound motion Electroforming Mechanical properties Nickel

Quantitative Analysis of Relationships Between Crack Characteristics and Properties of Soda-saline Soils in Songnen Plain, China

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Chinese Geographical Science 2015年第5期25卷 591-601页

作者： ren jianhua LI Xiaojie ZHAO Kai Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences Changchun Jingyuetan Remote Sensing Experiment Station Chinese Academy of Sciences

The Songnen Plain has a typical soda-saline soil, which often shrinks and cracks under natural conditions during water evaporation. This study aims to analyze the relationships between the crack characteristics and the soil properties of soda-saline soils quantitatively, and attempts to establish prediction models for the main soil properties of soda-saline soils based on the results. In order to achieve these objectives, a desiccation cracking test was conducted using 17 soil specimens with different salinity levels under controlled laboratory conditions. Correlation analysis was then performed between the crack characteristics and the soil properties. The results indicate that the crack characteristics can well represent the surface appearances of cracked soils, they also can well distinguish the salinity levels of soda-saline soils while the clay contents and mineralogical compositions of soils are stable. Among the crack characteristics, crack length has the best relationships with the salinity levels of soda-saline soils. Specifically, the crack length has high correlation(R2 > 0.87) with the electrical conductivity(EC), Na+, CO32– and the salinity, it also has reasonable relationship(R2 > 0.68) with HCO3–, this indicates crack length can be well used for the prediction of these properties of soda-saline soils.

关键词： soil salinization soda-saline soil desiccation cracking salinity texture features

Abrasive-assisted Nickel Electroforming Process with Moving Cathode

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 294-300页

作者： jianhua ren Zengwei ZHU Chunqiu XIA Ningsong QU Di ZHU College of Mechanical and Electrical Engineering NanjingUniversity of Aeronautics and AstronauticsNanjing 210016China

In traditional electroforming process for revolving parts with complex profiles, the drawbacks on surface of deposits, such as pinholes and nodules, will lead to varying physical and mechanical properties on different parts of electroformed components. To solve the problem, compositely moving cathode is employed in abrasive-assisted electroforming of revolving parts with complicated profiles. The cathode translates and rotates simultaneously to achieve uniform friction effect on deposits without drawbacks. The influences of current density and transla- tion speed on the microstructure and properties of the electroformed nickel layers are investigated. It is found that abrasive-assisted electroforming with compound cathode motion can effectively remove the pinholes and nodules, positively affect the crystal nucleation, and refine the grains of layer. The increase of current density will lead to coarse microstructure and lower micro hardness, from 325 HV down to 189 HV. While, faster translational linear speed produces better surface quality and higher micro hardness, from 236 HV up to 283 HV. The weld-ability of the electroformed layers are also studied through the metallurgical analysis of welded joints between nickel layer and 304 stainless steel. The electrodeposited nickel layer shows fine performance in welding. The novel compound motion of cathode promotes the mechanical properties and refines the microstructure of deposited layer.

关键词： Nickel electroforming · Abrasive · Compound motion · Weldability

Damage Diagnosis of Bleacher Based on an Enhanced Convolutional Neural Network with Training Interference

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Structural Durability & Health Monitoring 2024年第3期18卷 321-339页

作者： Chaozhi Cai Xiaoyu Guo Yingfang Xue jianhua ren School of Mechanical and Equipment Engineering Hebei University of EngineeringHandan056038China

Bleachers play a crucial role in practical engineering applications, and any damage incurred during their operationposes a significant threat to the safety of both life and property. Consequently, it becomes imperative to conductdamage diagnosis and health monitoring of bleachers. The intricate structure of bleachers, the varied types ofpotential damage, and the presence of similar vibration data in adjacent locations make it challenging to achievesatisfactory diagnosis accuracy through traditional time-frequency analysis methods. Furthermore, field environmentalnoise can adversely impact the accuracy of bleacher damage diagnosis. To enhance the accuracy and antinoisecapabilities of bleacher damage diagnosis, this paper proposes improvements to the existing ConvolutionalNeural Network with Training Interference (TICNN). The result is an advanced Convolutional Neural Networkmodel with superior accuracy and robust anti-noise capabilities, referred to as Enhanced TICNN (ETICNN).ETICNN autonomously extracts optimal damage-sensitive features from the original vibration data. To validatethe superiority of the proposed ETICNN, experiments are conducted using the bleacher model from Qatar Universityas the subject. Comparative studies under identical experimental conditions involve TICNN, Deep ConvolutionalNeural Networks with wide first-layer kernels (WDCNN), and One-Dimensional ConvolutionalNeural Network (1DCNN). The experimental findings demonstrate that the ETICNN model achieves the highestaccuracy, approximately 99%, and exhibits robust classification abilities in both Phases I and II of the damagediagnosis experiments. Simultaneously, the ETICNN model demonstrates strong anti-noise capabilities, outperformingTICNN by 3% to 4% and surpassing other models in performance.

关键词： Bleacher vibration signal damage diagnosis convolutional neural network anti-noise ability

A novel method for calculating broadband electrical performance of high-speed aircraft radome under thermo-mechanical-electrical coupling

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Chinese Journal of Aeronautics 2024年第9期37卷 463-474页

作者： Jianmin JI jianhua ren Xunya JIANG Wei WANG Huilong YU Kai YIN Bo CHEN Beijing Institute of Remote Sensing Equipment Beijing 100854China Shanghai Dong Jun Information and Technology Co.Ltd Shanghai 200050China

The electrical performance of radomes on high-speed aircraft can be influenced by the thermal and mechanical loads produced during high-speed flight,which can affect the detection dis-tance and accuracy of the guidance *** paper presents a new method that uses the Finite Difference Time Domain(FDTD)method to calculate the electrical performance of radomes under Thermo-Mechanical-Electrical(TME)*** method can accurately characterize the effects of material dielectric temperature drift and structural deformation on the electrical performance of the radome under flight conditions,enabling high-precision full-wave calculations of the broadband electrical performance of the *** method initiates by utilizing a Finite Element Grid Model(FE-GM)of the radome to sequentially acquire the radome's response temperature field and structural deformation field through thermal and mechanical ***,spatial mapping techniques are developed to accurately incorporate the dielectric temperature drift and structural deformation of the radome into its Yee grid Electromagnetic(EM)simulation model.A verification case was designed to test the proposed method,and the results confirmed its high computational ***,the effectiveness and necessity of the method were further demonstrated by analyzing the electrical performance of a fused silica ceramic radome used on a high-speed aircraft.

关键词： High-speed aircraft Radomes Thermo-Mechanical-Electrical(TME)coupling Finite Difference Time Domain(FDTD)method Spatial mapping

A Novel Graph Structure Learning Based Semi-Supervised Framework for Anomaly Identification in Fluctuating IoT Environment

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 3001-3016页

作者： Weijian Song Xi Li Peng Chen Juan Chen jianhua ren Yunni Xia School of Computer and Software Engineering Xihua UniversityChengdu610039China West China Second University Hospital Sichuan UniversityChengdu610065China School of Computer Science Chongqing UniversityChongqing400044China

With the rapid development of Internet of Things(IoT)technology,IoT systems have been widely applied in health-care,transportation,home,and other ***,with the continuous expansion of the scale and increasing complexity of IoT systems,the stability and security issues of IoT systems have become increasingly ***,it is crucial to detect anomalies in the collected IoT time series from various ***,deep learning models have been leveraged for IoT anomaly ***,owing to the challenges associated with data labeling,most IoT anomaly detection methods resort to unsupervised learning ***,the absence of accurate abnormal information in unsupervised learning methods limits their *** address these problems,we propose AS-GCN-MTM,an adaptive structural Graph Convolutional Networks(GCN)-based framework using a mean-teacher mechanism(AS-GCN-MTM)for anomaly *** performs better than unsupervised methods using only a small amount of labeled *** Teachers is an effective semi-supervised learning method that utilizes unlabeled data for training to improve the generalization ability and performance of the ***,the dependencies between data are often unknown in time series *** solve this problem,we designed a graph structure adaptive learning layer based on neural networks,which can automatically learn the graph structure from time series *** not only better captures the relationships between nodes but also enhances the model’s performance by augmenting key *** have demonstrated that our method improves the baseline model with the highest F1 value by 10.4%,36.1%,and 5.6%,respectively,on three real datasets with a 10%data labeling rate.

关键词： IoT multivariate time series anomaly detection graph learning semi-supervised mean teachers

Hyaluronic acid-curcumin conjugate suppresses the fibrotic functions of myofibroblasts from contractive joint by the PTGER2 demethylation

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Regenerative Biomaterials 2019年第5期6卷 269-277页

作者： Dongjie Yu Ze Zhuang jianhua ren Xuefeng Hu Zhe Wang Jieyu Zhang Yuansen Luo Kun Wang Ronghan He Yunbing Wang Department of Orthopedic Surgery The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510000China National Engineering Research Center for Biomaterials Sichuan UniversityChengdu 610000China

Joint contracture is a fibrotic complication induced by joint immobilization and trauma,which is characterized as excessive myofibroblast proliferation in joint *** treatments of joint contracture are unsatisfied and patients are suffered from joint *** previous study has shown that curcumin can inhibit myofibroblast proliferation in vitro,but the major challenge is the low aqueous solubility and biological activity of *** this study,hyaluronic acid-curcumin(HA-Cur)conjugate was synthesized to suppress myofibroblasts in joint *** were isolated from the joint capsules of joint contracture patients and induced to active myofibroblasts by transforming growth factor-b(TGF-b).The anti-fibrotic function and mechanisms of HA-Cur were investigated by immunohistochemistry,reverse transcription-quantitative polymerase chain reaction(PCR),methylation-specific PCR,western blot,transwell migration assay and proliferation *** showed that 30 lM HA-Cur significantly attenuated the fibrotic functions of myofibroblast in joint contracture in vitro by regulating the methylation of prostaglandin E receptor 2(PTGER2)and inhibiting TGF-b *** may provide a mechanism for the treatment of joint contracture,and provide a molecular target PTGER2 for therapy during the pathogenesis of joint contracture.

关键词： curcumin PTGER2 methylation joint contracture

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环形腔掺铒光纤激光器的理论研究

中国激光 2009年第3期36卷 653-657页

作者：肖鸿飞任建华沈阳大学物理系辽宁沈阳110044 北京邮电大学安立光电检测研究中心北京100876

从基本激光理论出发,建立了掺铒光纤激光器的传播方程。掺铒光纤在1550 nm波长处具有很高的增益,正对应低损耗通信窗口,具有潜在的应用价值。抽运光模强度分布与纤芯铒离子分布的重叠积分因子是对激光器非常重要的参数,将对光纤的模式... 详细信息

从基本激光理论出发,建立了掺铒光纤激光器的传播方程。掺铒光纤在1550 nm波长处具有很高的增益,正对应低损耗通信窗口,具有潜在的应用价值。抽运光模强度分布与纤芯铒离子分布的重叠积分因子是对激光器非常重要的参数,将对光纤的模式进行分析,根据各个模式的模场来判断该模式是否与纤芯铒离子分布有重叠,研究了与介质吸收截面有关的重叠积分的影响因素;对放大自发辐射(ASE)噪声特性进行理论分析,给出增益、阈值功率和斜率效率等的解析形式,建立输出特性计算模型。针对这种环形腔掺铒光纤激光器,编写专门的计算程序,在输出特性等方面进行理论计算仿真,对该结构布局所带来的影响进行详细分析讨论。

关键词：光纤激光器环形腔掺铒光纤阈值功率

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入世后煤炭外经贸企业的应对措施

中国煤炭 2001年第8期27卷 39-40,64页

作者：任建华神华国际贸易有限公司北京市东城区100011

分析了我国煤炭外经贸企业的现状和面临的形势 ,认为煤炭外经贸企业要应对WTO ,应抓住机遇 ,积极开拓对外工程承包市场 ,加快结构调整 ,扩大煤炭与煤机产品出口。

关键词：工程承包出口 WTO 煤机产品煤炭外经贸企业经济结构调整煤炭行业