Modeling and dynamic analysis of artillery barrel-cradle structure with clearance

Jie Liu,Changda Wang,Bingbing Hu,Bing Li 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.4

Clearance is unavoidable in artillery barrel-cradle mechanism due to the need for relative motion, and has been considered as a key factor to affect the artillery firing accuracy. Therefore, in this paper, the dynamic behaviors of artillery barrel-cradle structure are studied. The barrel-cradle structure is simplified as a variable cross-section barrel structure with two clearances, and nonlinear spring-damping model is used to describe the clearance contact force. And then, based on solving the dynamic response of such model, the clearance effects on muzzle vibration, contact force and dynamic characteristics (frequency response function and “hardening” effect) are also analyzed in detail. Furthermore, this paper also presents an improved identification algorithm which is combining the probability density derivative method and nonlinear detection to identify the clearance value. These studies can provide better understanding of clearance effects and contribute significantly to improving firing accuracy by adjusting the clearance.

A hybrid method for dynamic stiffness identification of bearing joint of high speed spindles

Yongsheng Zhao,Bingbing Zhang,Guoping An,Zhifeng Liu,Ligang Cai 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.57 No.1

Bearing joint dynamic parameter identification is crucial in modeling the high speed spindles for machining centers used to predict the stability and natural frequencies of high speed spindles. In this paper, a hybrid method is proposed to identify the dynamic stiffness of bearing joint for the high speed spindles. The hybrid method refers to the analytical approach and experimental method. The support stiffness of spindle shaft can be obtained by adopting receptance coupling substructure analysis method, which consists of series connected bearing and joint stiffness. The bearing stiffness is calculated based on the Hertz contact theory. According to the proposed series stiffness equation, the stiffness of bearing joint can be separated from the composite stiffness. Then, one can obtain the bearing joint stiffness fitting formulas and its variation law under different preload. An experimental set-up with variable preload spindle is developed and the experiment is provided for the validation of presented bearing joint stiffness identification method. The results show that the bearing joint significantly cuts down the support stiffness of the spindles, which can seriously affects the dynamic characteristic of the high speed spindles.

Pancreatic regulation of glucose homeostasis

Pia V Röder,Bingbing Wu,Yixian Liu,Weiping Han 생화학분자생물학회 2016 Experimental and molecular medicine Vol.48 No.-

In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed.

Ethanol Production by Repeated Batch and Continuous Fermentations by Saccharomyces cerevisiae Immobilized in a Fibrous Bed Bioreactor

( Yong Chen ),( Qingguo Liu ),( Tao Zhou ),( Bingbing Li ),( Shiwei Yao ),( An Li ),( Jing Lan Wu ),( Han Jie Ying ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.4

In this work, a fibrous bed bioreactor with high specific surface area and good adsorption efficacy for S. cerevisiae cells was used as the immobilization matrix in the production of ethanol. In batch fermentation, an optimal ethanol concentration of 91.36 g/l and productivity of 4.57 g l-1 h-1 were obtained at an initial sugar concentration of 200 g/l. The ethanol productivity achieved by the immobilized cells was 41.93% higher than that obtained from free cells. Ethanol production in a 22-cycle repeated batch fermentation demonstrated the enhanced stability of the immobilized yeast cells. Under continuous fermentation in packed-bed reactors, a maximum ethanol concentration of 108.14 g/l and a productivity of 14.71 g l-1 h-1 were attained at 35oC, and a dilution rate of 0.136 h-1 with 250 g/l glucose.

High-Performance Solution-Processed Non-Fullerene Organic Solar Cells Based on Selenophene-Containing Perylene Bisimide Acceptor

Meng, Dong,Sun, Dan,Zhong, Chengmei,Liu, Tao,Fan, Bingbing,Huo, Lijun,Li, Yan,Jiang, Wei,Choi, Hyosung,Kim, Taehyo,Kim, Jin Young,Sun, Yanming,Wang, Zhaohui,Heeger, Alan J. American Chemical Society 2016 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.138 No.1

<P>Non-fullerene acceptors have recently attracted tremendous interest because of their potential as alternatives to fullerene derivatives in bulk heterojunction organic solar cells. However, the power conversion efficiencies (PCEs) have lagged far behind those of the polymer/fullerene system, mainly because of the low fill factor (FF) and photocurrent. Here we report a novel perylene bisimide (PBI) acceptor, SdiPBI-Se, in which selenium atoms were introduced into the perylene core. With a well-established wide-band-gap polymer (PDBT-T1) as the donor, a high efficiency of 8.4% with an unprecedented high FF of 70.2% is achieved for solution-processed non-fullerene organic solar cells. Efficient photon absorption, high and balanced charge carrier mobility, and ultrafast charge generation processes in PDBT-T1:SdiPBI-Se films account for the high photovoltaic performance. Our results suggest that non-fullerene acceptors have enormous potential to rival or even surpass the performance of their fullerene counterparts.</P>

Production of Butanol from Glucose and Xylose with Immobilized Cells of Clostridium acetobutylicum

Yong Chen,Tao Zhou,Dong Liu,An Li,Songbo Xu,Qingguo Liu,Bingbing Li,Han-Jie Ying 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

Pretreated cotton towels were used as carriers to immobilize Clostridium acetobutylicum CGMCC 5234cells for butanol or ABE production from glucose and xylose. Results showed that cell immobilization was a promising method to increase butanol concentration, yield and productivity regardless of the sugar sources compared with cell suspension. In this study, a high butanol concentration of 10.02 g/L with a yield of 0.20 g/g was obtained from 60 g/L xylose with 9.9 g/L residual xylose using immobilized cells compared with 8.48 g/L butanol and a yield of 0.141 g/g with 20.2 g/L residual xylose from 60 g/L xylose using suspended cells. In mixed-sugar fermentation (30 g/L glucose plus 30 g/L xylose), the immobilized cultures produced 11.1 g/L butanol with a yield of 0.190 g/g, which were 28.3% higher than with suspended cells (8.65 g/L) during which 30 g/L glucose was utilized completely using both immobilized and suspended cells while 3.46 and 13.1 g/L xylose maintained untilized for immobilized and suspended cells, respectively. Based on the results, we speculated that immobilized cells showed enhanced tolerance to butanol toxicity and the cultures preferred glucose to xylose during ABE fermentation. Moreover, the cultures showed obvious difference when grown between high initial concentrations of glucose and those of xylose. Repeated-batch fermentations from glucose with immobilized cells showed better long-term stability than from xylose. At last, the morphologies of free and immobilized cells adsorbed on pretreated cotton towels during the growth cycle were examined by SEM.

Draft Genome Assembly and Annotation for Cutaneotrichosporon dermatis NICC30027, an Oleaginous Yeast Capable of Simultaneous Glucose and Xylose Assimilation

Wang Laiyou,Guo Shuxian,Zeng Bo,Wang Shanshan,Chen Yan,Cheng Shuang,Liu Bingbing,Wang Chunyan,Wang Yu,Meng Qingshan 한국균학회 2022 Mycobiology Vol.50 No.1

The identification of oleaginous yeast species capable of simultaneously utilizing xylose and glucose as substrates to generate value-added biological products is an area of key eco- nomic interest. We have previously demonstrated that the Cutaneotrichosporon dermatis NICC30027 yeast strain is capable of simultaneously assimilating both xylose and glucose, resulting in considerable lipid accumulation. However, as no high-quality genome sequenc- ing data or associated annotations for this strain are available at present, it remains chal- lenging to study the metabolic mechanisms underlying this phenotype. Herein, we report a 39,305,439 bp draft genome assembly for C. dermatis NICC30027 comprised of 37 scaffolds, with 60.15% GC content. Within this genome, we identified 524 tRNAs, 142 sRNAs, 53 miRNAs, 28 snRNAs, and eight rRNA clusters. Moreover, repeat sequences totaling 1,032,129 bp in length were identified (2.63% of the genome), as were 14,238 unigenes that were 1,789.35 bp in length on average (64.82% of the genome). The NCBI non-redundant protein sequences (NR) database was employed to successfully annotate 11,795 of these unigenes, while 3,621 and 11,902 were annotated with the Swiss-Prot and TrEMBL databases, respectively. Unigenes were additionally subjected to pathway enrichment analyses using the Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Cluster of Orthologous Groups of proteins (COG), Clusters of orthologous groups for eukaryotic com- plete genomes (KOG), and Non-supervised Orthologous Groups (eggNOG) databases. Together, these results provide a foundation for future studies aimed at clarifying the mech- anistic basis for the ability of C. dermatis NICC30027 to simultaneously utilize glucose and xylose to synthesize lipids.

Mixed Reinforcement Learning for Efficient Policy Optimization in Stochastic Environments

Yao Mu,Baiyu Peng,Ziqing Gu,Shengbo Eben Li,Chang Liu,Bingbing Nie,Jianfeng Zheng,Bo Zhang 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

Reinforcement learning has the potential to control stochastic nonlinear systems in optimal manners successfully. We propose a mixed reinforcement learning (mixed RL) algorithm by simultaneously using dual representations of environmental dynamics to search the optimal policy. The dual representation includes an empirical dynamic model and a set of state-action data. The former can embed the designer’s knowledge and reduce the difficulty of learning, and the latter can be used to compensate the model inaccuracy since it reflects the real system dynamics accurately. Such a design has the capability of improving both learning accuracy and training speed. In the mixed RL framework, the additive uncertainty of stochastic model is compensated by using explored state-action data via iterative Bayesian estimator (IBE). The optimal policy is then computed in an iterative way by alternating between policy evaluation (PEV) and policy improvement (PIM). The effectiveness of mixed RL is demonstrated by a typical optimal control problem of stochastic non-affine nonlinear systems (i.e., double lane change task with an automated vehicle).

Pharmacokinetic difference of berberine between normal and chronic visceral hypersensitivity irritable bowel syndrome rats and its mechanism

Zipeng Gong,Ying Chen,Ruijie Zhang,Qing Yang,Yajie Wang,Yan Guo,Bingbing Zhou,Xiaogang Weng,Xuchen Liu,Yujie Li,Xiaoxin Zhu,Yu Dong 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.10

Berberine is one of active alkaloids from Rhizomacoptidis in traditional Chinese medicine. The pharmacokineticsof berberine in rat plasma were compared betweennormal and chronic visceral hypersensitivity irritable bowelsyndrome rats (CVH-IBS) established by mechanical colonirritation using angioplasty balloons for 2 weeks after oraladministration of berberine hydrochloride (25 mg/kg) withthe equivalent dose of 22 mg/kg for berberine according tobody weight. Immunohistochemical analysis of c-fos andmyosin light chain kinase (MLCK) and immunofluorescenceanalysis of MLCK in rat colon were conducted. Quantificationof berberine in rat plasma was achieved by using a sensitiveand rapidUPLC-MS/MSmethod. Plasma samples werecollected at 15 different points in time and the pharmacokineticparameters were analyzed by WinNonlin software. Thegreat different pharmacokinetic behavior of berberine wasobserved between normal and CVH-IBS model rats. Compared with normal group, T1/2 and AUC(0–t) of berberinein the model group were significantly increased, respectively(573.21 ± 127.53 vs 948.22 ± 388.57 min; 8,657.19 ±1,562.54 vs 11,415.12 ± 1,670.72 min.ng/ml). Cl/F of berberinein the model group significantly decreased, respectively(13.89 ± 1.69 vs 9.19 ± 2.91 L/h/kg). Additionally,the expressions of c-fos and MLCK in model group werehigher than those in normal group. The pharmacokinetic behaviorof berberine was significantly altered in CVH-IBSpathological conditions, which indicated the dosage modificationof berberine hydrochloride in CVH-IBS were necessary. Especially, improved exposure to berberine in ratplasma inCVH-IBSmodel rats was attributed to increased theexpression of MLCK.

Automated Door Opening Scheme for Non-holonomic Mobile Manipulator

Albertus Hendrawan Adiwahono,Chua Yuanwei,Tee Keng Peng,Liu Bingbing 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

This paper describes a scheme on automated door opening for a non-holonomic mobile manipulator. The perception is done with a fast 2D door plane scan and followed by a 3D door handle recognition. A driving planner is used to drive robot to the intended spot in front of the door with minimum off center error. Then, a simple yet effective downstroke motion of the arm is used to turn the handle. Finally, experiments is used to validate and evaluate the proposed scheme.