Accuracy analysis of spatial multi-loop mechanism effected by paired bearings support joint clearance

Fei Lin,Chuanzhi Chen,Jinbao Chen,Meng Chen 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.3

The primary objective of this work is to present a three-dimensional (3D) clearance model of the paired bearings support joint (PBS-joint) and address the influence of PBSjoint clearance on the accuracy of the spatial multi-loop mechanism. Through the synthetic use of the vector and homogeneous coordinate transformation methods, the 3D clearance model of the PBS-joint is obtained on the basis of the static balance condition. When clearance is equated as a spatial virtual link, the error space solution models of serial mechanism and single-loop mechanism are developed respectively according to the Denavit-Hartenberg method and the geometric closure condition. The error space standardization solution model of the multi-loop mechanism is then presented through improving the low-layer loop sequence description method of the topological structure relations. Finally, the application in the basic loop mechanism is demonstrated to discuss the procedures adopted in this work and the influence of the PBS-joint clearance. Results show that the PBS-joint clearance may cause the error on the point with a 3D deviation transmission path to deviate the normal distribution. Moreover, the plane-joint clearance model may not yield an accurate analysis of the spatial mechanism.

Dimensional Synthesis of Antenna-Deployable Support Structure

Fei Lin,Chuanzhi Chen,Jinbao Chen,Meng Chen 한국항공우주학회 2020 International Journal of Aeronautical and Space Sc Vol.21 No.2

To improve the deployment stability and drive efficiency, the dimensional synthesis of antenna deployable support structure is addressed. First, to evaluate the deployment stability, the transmission ratio stability index (TRSI) is designed based on Jacobian matrix. Second, the motion/force transmissibility is used to analyse the drive efficiency. A sub-closed-loop analysis method (SAM) is proposed to analyse the local motion/force transmissibility of the parallel mechanism whose sub-closed-loop contains actuator (PMSCA). An improved global transmission index (IGTI) is proposed to analyse the global motion/force transmissibility for the mechanism without good transmission workspace (GTW). Finally, based on TRSI and IGTI, the dimensional parameter optimization model of the deployable support structure is established and a configuration with better comprehensive performance is obtained. Results show that the designed indexes in this paper can be useful for indicating the stability of transmission ratio and the global motion/force transmissibility of the structure.

In Situ Growth of MOF-Derived NaCoPO4@Carbon for Asymmetric Supercapacitive and Water Oxidation Electrocatalytic Performance

Peng Guo,Zhaojie Wang,Hongyu Chen,Shaohui Ge,Chen Chen,Haowei Wang,Jinbao Zhang,Minglei Hua,Shuxian Wei,Xiaoqing Lu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01

The increasing energy crisis promotes the study on novel electrode materials with high performance for supercapacitive storage and energy conversion. Transition metal phosphates have been reported as a potential candidate due to the unique coordination and corresponding electronic structure. Herein, we adopted a facile method for preparing NaCoPO4@C derived from a metal organic framework (MOF) as a bifunctional electrode. ZIF-67 was synthesized before a refluxing process with Na2HPO4 to form a precursor, which is transformed into the final product via calcination in different atmospheres. Specifically, the resultant NaCoPO4@C exhibits a high specific capacitance of 1178.7 F g -1 at a current density of 1 A g -1 for a supercapacitor. An asymmetric supercapacitor (ASC) assembled with active carbon displays a high capacitance of 163.7 F g -1 at 1 A g -1. In addition, as an oxygen evolution reaction (OER) catalyst, the NaCoPO4@C electrode requires only 299 mV to drive a current density of 10 mA cm -2. These results suggest that the rational design of MOF-derived NaCoPO4@C provides a variety of practical applications in electrochemical energy conversion and storage.

Identification and functional prediction of long non-coding RNAs related to oxidative stress in the jejunum of piglets

Li Jinbao,Zhang Jianmin,Jin Xinlin,Li Shiyin,Du Yingbin,Zeng Yongqing,Wang Jin,Chen Wei 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.2

Objective: Oxidative stress (OS) is a pathological process arising from the excessive production of free radicals in the body. It has the potential to alter animal gene expression and cause damage to the jejunum. However, there have been few reports of changes in the expression of long noncoding RNAs (lncRNAs) in the jejunum in piglets under OS. The purpose of this research was to examine how lncRNAs in piglet jejunum change under OS. Methods: The abdominal cavities of piglets were injected with diquat (DQ) to produce OS. Raw reads were downloaded from the SRA database. RNA-seq was utilized to study the expression of lncRNAs in piglets under OS. Additionally, six randomly selected lncRNAs were verified using quantitative real-time polymerase chain reaction (qRT‒PCR) to examine the mechanism of oxidative damage. Results: A total of 79 lncRNAs were differentially expressed (DE) in the treatment group compared to the negative control group. The target genes of DE lncRNAs were enriched in gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathways. Chemical carcinogenesis-reactive oxygen species, the Foxo signaling pathway, colorectal cancer, and the AMPK signaling pathway were all linked to OS. Conclusion: Our results demonstrated that DQ-induced OS causes differential expression of lncRNAs, laying the groundwork for future research into the processes involved in the jejunum’s response to OS.

A Robust Optimization Method Utilizing the Variance Decomposition Method for Electromagnetic Devices

Shujuan Wang,Qiuyang Li,Jinbao Chen 한국자기학회 2014 Journal of Magnetics Vol.19 No.4

Uncertainties in loads, materials and manufacturing quality must be considered during electromagnetic devices design. This paper presents an effective methodology for robust optimization design based on the variance decomposition in order to keep higher accuracy of the robustness prediction. Sobol’ theory is employed to estimate the response variance under some specific tolerance in design variables. Then, an optimal design is obtained by adding a criterion of response variance upon typical optimization problems as a constraint of the optimization. The main contribution of this paper is that the proposed method applies the variance decomposition to obtain a more accurate variance of the response, as well save the computational cost. The performance and robustness of the proposed algorithms are investigated through a numerical experiment with both an analytic function and the TEAM 22 problem.

Effect of 3.7 at% F doping on the atomic structure and reducibility of CeO2(111) surface: A first principles calculation

Jia Huiling,Hu Jinbao,Chen Hao,Wu Jinxiu,Tan Xin,Sun Shiyang 한국물리학회 2022 Current Applied Physics Vol.43 No.-

Density functional theory calculations was conducted to clarify effect of fluorination on the reducibility of CeO2 polishing powder. The atomic structure and O vacancy formation energy of F-doped CeO2(111) surface were systematically calculated, and electronic structure was also analyzed to understand the calculation results. It showed that the CeO1.963(111) surface needs absorb 7.853 eV to be reduced further, so it is difficult to generate the second O vacancy (V2). After fluorination, the first O vacancy (V1) in CeO1.926F0.037(111) surface caused adjacent atoms to move significantly, and O vacancy formation energy decreased to 2.913 eV, which promoted the formation of V2. Moreover, electronic structure calculation also showed that the interaction between O2p and Ce4f5d orbits was enhanced in reduced CeO1.963(111) surface, which hindered the formation of V2. The F2p orbit in CeO1.926F0.037(111) surface moved towards the low energy level, V1 made the reduced surface stable and promoted the formation of V2.

Catalytic performances and leaching behavior of typical natural iron minerals as electro-Fenton catalysts for mineralization of imidacloprid

Wenwei Yu,Faying Lai,Jinbao He,Kaiyun He,Rong Wang,Danping Li,Quanyuan Chen 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

Catalytic performances and leaching behavior of 9 natural iron minerals as heterogeneous electro-Fentoncatalysts for the treatment of imidacloprid wastewater were studied. The results showed that magnesioferriteexhibited the best catalytic ability among these minerals with UV absorbance at 270 nm (UV270)removal of 83.59% and COD removal of 49.11% within 4 h using graphite cathode and Ti/(RuO2)0.88-(IrO2)0.12 anode at initial pH 3 with a catalyst dose of 5 g/L, a current density of 40 mA/cm2 and an electrodespacing of 2 cm. The instantaneous current efficiency (ICE) at 4 h and energy consumption (EC)reached 2.30% and 2.20 kWh/gCOD respectively. It was found that the components contained in naturaliron minerals, such as Al, alkali metal (K) and alkaline earth metals (Mg, Ca, Ba), would dissolve into theelectrolyte solution, raising the final pH to 6.5–8.5 and ultimately reducing the reaction efficiency. Exceptmagnetite and magnesioferrite, other minerals, such as ilmenite and V-Ti magnetite, were likely to causesecondary pollution. The subsequent adjustment to alkaline state for chemical precipitation of leachedMn was needed. Pyrite showed relatively high leachability in hazardous elements (especially Pb), whichshould be carefully evaluated before its actual application in electro-Fenton process.

Image recognition technology in rotating machinery fault diagnosis based on artificial immune

Zhu Dachang,Feng Yanping,Chen Qiang,Cai Jinbao 국제구조공학회 2010 Smart Structures and Systems, An International Jou Vol.6 No.4

By using image recognition technology, this paper presents a new fault diagnosis method for rotating machinery with artificial immune algorithm. This method focuses on the vibration state parameter image. The main contribution of this paper is as follows: firstly, 3-D spectrum is created with raw vibrating signals. Secondly, feature information in the state parameter image of rotating machinery is extracted by using Wavelet Packet transformation. Finally, artificial immune algorithm is adopted to diagnose rotating machinery fault. On the modeling of 600MW turbine experimental bench, rotor normal rate, fault of unbalance, misalignment and bearing pedestal looseness are being examined. It demonstrated from the diagnosis example of rotating machinery that the proposed method can improve the accuracy rate and diagnosis system robust quality effectively.

Design and Implementation of Vibration Isolation System for Mobile Doppler Wind LIDAR

Xiaoquan Song,Chao Chen,Bingyi Liu,Jinbao Xia,Samo Stanič 한국광학회 2013 Current Optics and Photonics Vol.17 No.1

The operation of a Doppler wind LIDAR in a mobile environment is very sensitive to shocks and vibrations, which can cause critical failures such as misalignment of the optical path and damage to optical components. To be able to stabilize the LIDAR and to perform wind field measurements in motion, a shock absorption and vibration isolation system was designed and implemented. The performance of the vehicle-mounted Doppler wind LIDAR was tested in motion, first in a circular test route with a diameter of about 30 m and later in regular expressway traffic. The vibration isolation efficiency of the system was found to be higher than 82% in the main vibration area and shock dynamic deflection was smaller than maximal deflection of the isolator. The stability of the laser locking frequency in the same mobile environment before and after the vibration isolation system installation was also found to be greatly improved. The reliability of the vibration isolation system was confirmed by good results of the analysis of the LIDAR data, in particular the plane position indicator of the line of sight velocity and the wind profile.

The deubiquitinating enzyme STAMBP is a newly discovered driver of triple-negative breast cancer progression that maintains RAI14 protein stability

Yang Qianqian,Yan Ding,Zou Chaoying,Xue Qian,Lin Shuhui,Huang Qingtian,Li Xiaofen,Tang Daolin,Chen Xin,Liu Jinbao 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Triple-negative breast cancer (TNBC) is a heterogeneous malignancy in women. It is associated with poor prognosis, aggressive malignant behavior, and limited treatment options. In the ubiquitin‒proteasome system (UPS), deubiquitinases (DUBs) are potential therapeutic targets for various tumors. In this study, by performing unbiased siRNA screening, we identified STAMBP, a JAMM metalloprotease in the DUB family, as a driver of human TNBC tumor growth. Functionally, the knockdown of STAMBP inhibited the proliferation, migration, and invasion of multiple TNBC cell lines. Immunoprecipitation–mass spectrometry combined with functional and morphological analysis verified the interaction between STAMBP and the actin-binding protein RAI14. Mechanistically, STAMBP stabilized the RAI14 protein by suppressing the K48-linked ubiquitination of RAI14 and thus prevented its proteasomal degradation. Therefore, knocking down STAMBP resulted in the reduction in RAI14 protein levels and suppression of tumor growth in vitro and in vivo. Importantly, high levels of STAMBP were correlated with poor prognosis in TNBC patients. In summary, we reveal a previously unrecognized DUB pathway that promotes TNBC progression and provides a rationale for potential therapeutic interventions for the treatment of TNBC.