Investigation on high contact ratio harmonic two-dimensional tooth profile design based on mid-point meshing method

Jianzhong Huang,Jiu-Hua Xu,Ning Qian 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.2

Loading capacity and drive stability could be improved by a high contact ratio tooth profile, which is important to a harmonic drive. A novel mid-point meshing method is proposed to achieve the high contact ratio harmonic two-dimensional curve tooth profile. According to the kinematic relationship between points on the neutral layer coordinate of the flex-spline and corresponding points on the pitch circle coordinate of the circular spline, a new meshing point is generated by taking the middle point of the two meshing points. Then, mathematical proof and kinematic simulation analysis are conducted. The curve has characteristics of a high contact ratio and continuous meshing, and zero backlashes in theory. The main factors affecting the curve are also analyzed. Finally, a tooth profile is designed, and two-dimensional meshing performance is analyzed. Results show that the curve contact ratio is 65.54, and backlash values remain at 5×10 -3 μm.

A New Iterative LT Decoding Algorithm for Binary and Nonbinary Galois Fields

Mao, Yuexin,Huang, Jie,Wang, Bing,Huang, Jianzhong,Zhou, Wei,Zhou, Shengli The Korea Institute of Information and Commucation 2013 Journal of communications and networks Vol.15 No.4

Digital fountain codes are record-breaking codes for erasure channels. They have many potential applications in both wired and wireless communications. Most existing digital fountain codes operate over binary fields using an iterative belief-propagation (BP) decoding algorithm. In this paper, we propose a new iterative decoding algorithm for both binary and nonbinary fields. The basic form of our proposed algorithm considers both degree-1 and degree-2 check nodes (instead of only degree-1 check nodes as in the original BP decoding scheme), and has linear complexity. Extensive simulation demonstrates that it outperforms the original BP decoding scheme, especially for a small number of source packets. The enhanced form of the proposed algorithm combines the basic form of the algorithm and a guess-based algorithm to further improve the decoding performance. Simulation results demonstrate that it can provide better decoding performance than the guess-based algorithm with fewer guesses, and can achieve decoding performance close to that of the maximum likelihood decoder at a much lower decoding complexity. Last, we show that our nonbinary scheme has the potential to outperform the binary scheme when choosing suitable degree distributions, and furthermore it is insensitive to the size of the Galois field.

Impact resistance and damage assessment of steel beams with different web openings

Huayan Chen,Jianzhong Huang,Chaojiang Fu,Sixiang Wang,Fengxuan Wang,Caisong Luo,Bizhen Wang 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.2

To investigate the impact resistance of steel beams with diff erent web openings, falling-hammer impact trials and numerical models analyses were performed, focusing on the impact energy, inter-opening space, and opening diameter. The impact resistance of steel beams with diff erent web openings was analyzed, and damage-assessment curves for web-opening steel beams (WOSBs) under impact loads were established. The results showed that web-hexagonal-opening steel beams (WHOSBs) yielded greater damage-related deformation than web-circular-opening steel beams (WCOSBs) for the same impact energy. The average maximum mid-span displacement of the WCOSBs under the falling-hammer was 86.49% that of the WHOSBs, whereas the average energy absorption rate was 6.07% higher. The WCOSBs were more resistant to impacts than the WHOSBs. The impact velocity and mass were the key damage-assessment parameters, and velocity–mass damage-assessment curves and determination equations were established according to on the WOSBs’ maximum mid-span displacement under hinge-supported restraints at both ends. Thus, this study will serve as a reference for assessing the damages of WOSBs subjected to impacts.

Zein–sodium alginate based microcapsules for essence controlled releasing coating as leather finishes

Qunna Xu,Zhongxue Bai,Jianzhong Ma,Yuxi Yang,Mengchen Huang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.100 No.-

Currently the development and application of leather are strongly limited by the peculiar smells of theleather itself and the chemical residues in the leather. However, traditionalfinishing materials containingessences have a short release period, but also weaken the mechanical properties of the coating. Herein,wefirst report a route of crafting essence controlled releasing coatings as leatherfinishes comprisingzein–sodium alginate microcapsules loaded with Artemisia argyi essence (AAE@Z-SMs) and caseinmodified by caprolactam (Ca-Cpl), of which AAE@Z-SMs was prepared by anti-solvent precipitationtechnique before physically blended with Ca-Cpl to prepare composite coating. The results showed thatthe average particle size of AAE@Z-SMs was about 5.7 mm, and the accumulative release rate of essence inAAE@Z-SMs was 48.3% after continuous release for 120 h. Besides, the AAE@Z-SMs+Ca-Cplfilm istransparent and has goodflexibility, with pores and microspheres uniformly distributed inside. Moreover, the inhibition zones of the leather samplesfinished by AAE@Z-SMs+Ca-Cpl against Escherichiacoli (E. coli) (1st d) and Staphylococcus aureus (S. aureus) (2nd d) were 2.6 cm and 4.2 cm respectively,which hardly changed after continuing culture for 2 days. Moreover, expected sanitary, mechanical andantibacterial properties of the leatherfinished could be given by AAE@Z-SMs based composites. Thisstudy provides a feasible way to prepare composite coating materials with functionality based on naturalprotein, polysaccharide and plant essence.

A New Iterative LT Decoding Algorithm for Binary and Nonbinary Galois Fields

Yuexin Mao,Jie Huang,Bing Wang,Jianzhong Huang,Wei Zhou,Shengli Zhou 한국통신학회 2013 Journal of communications and networks Vol.15 No.4

Digital fountain codes are record-breaking codes for erasure channels. They have many potential applications in both wired and wireless communications. Most existing digital fountain codes operate over binary fields using an iterative belief-propagation (BP) decoding algorithm. In this paper, we propose a new iterative decoding algorithm for both binary and nonbinary fields. The basic form of our proposed algorithm considers both degree-1 and degree-2 check nodes (instead of only degree-1 check nodes as in the original BP decoding scheme), and has linear complexity. Extensive simulation demonstrates that it outperforms the original BP decoding scheme, especially for a small number of source packets. The enhanced form of the proposed algorithm combines the basic form of the algorithm and a guess-based algorithm to further improve the decoding performance. Simulation results demonstrate that it can provide better decoding performance than the guess-based algorithm with fewer guesses, and can achieve decoding performance close to that of the maximum likelihood decoder at a much lower decoding complexity. Last, we show that our nonbinary scheme has the potential to outperform the binary scheme when choosing suitable degree distributions, and furthermore it is insensitive to the size of the Galois field.

Heterologous Expression of a Gibberellin 2-Oxidase Gene from Arabidopsis thaliana Enhanced the Photosynthesis Capacity in Brassica napus L.

Bo Zhou,Dan Peng,Jianzhong Lin,Xingqun Huang,Wusheng Peng,Reqing He,Ming Guo,Dongying Tang,Xiaoying Zhao,Xuanming Liu 한국식물학회 2011 Journal of Plant Biology Vol.54 No.1

Gibberellins (GAs) are endogenous hormones that play an important role in regulating plant stature by increasing cell division and promoting seed germination. The GA2-oxidase gene from Arabidopsis thaliana (AtGA2ox8) was introduced into Brassica napus L. by Agrobacterium-mediated floral-dip transformation with the aim of decreasing the amount of bioactive GA and hence reduced the plant height. As anticipated, the transgenic plant exhibited dwarf phenotype. Importantly, compared with the wild type, the transgenic plants had delayed the seed germination, increased the chlorophyll content (28.7–36.3%) and photosynthesis capacity (14.3–18.7%) in a single leaf. At the same time, the photosynthesis capacity of the whole plants was significantly enhanced (35.7–48.6%) due to the extra leaves and branches.

Efficient Expression and Purification of Recombinant Alcohol Oxidase in Pichia pastoris

Yunping Liu,Jianfeng Pan,Peilian Wei,Jianzhong Zhu,Lei Huang,Jin Cai,Zhinan Xu 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.4

In order to improve the production of alcohol oxidase (AOX), a recombinant Pichia pastoris (P. pastoris)system was constructed by transformation of the plasmid pPIC9K-AOX into P. pastoris GS115. The effects of different expression conditions on alcohol oxidase activity in the culture supernatant were investigated in the shake flask scale. The results showed that the highest extracellular activity (562 U/L) of alcohol oxidase was obtained after 56h induction with 4% methanol at OD600 1.0 in the medium containing 50 g/L maltose, which is about 4.2 folds higher than previously reported. High-purity functional recombinant AOX (>90%) was purified from the culture with the Ni-NTA affinity column and Sephadex G-100 chromatographical methods, with a total recovery rate of 68.9%. Further studies showed that the purified rAOX had similar enzymatic characteristics as the native enzyme, except that the thermal stability and resistance to H2O2 inhibition of rAOX were significantly greater compared to the previous report. The purified rAOX was well tolerant to various water-miscible organic solvents. This efficient expression and purification process will be promising for large-scale production of rAOX as an important diagnostic enzyme for alcohol detection in many areas.

Herbal medicine and gut microbiota: exploring untapped therapeutic potential in neurodegenerative disease management

Yueyue Guan,Guohua Tang,Lei Li,Jianzhong Shu,Yuhua Zhao,Li Huang,Jun Tang 대한약학회 2024 Archives of Pharmacal Research Vol.47 No.2

The gut microbiota that exists in the human gastrointestinal tract is incredibly important for the maintenance of general healthas it contributes to multiple aspects of host physiology. Recent research has revealed a dynamic connection between the gutmicrobiota and the central nervous system, that can infl uence neurodegenerative diseases (NDs). Indeed, imbalances in thegut microbiota, or dysbiosis, play a vital role in the pathogenesis and progression of human diseases, particularly NDs. Herbalmedicine has been used for centuries to treat human diseases, including NDs. These compounds help to relieve symptomsand delay the progression of NDs by improving intestinal barrier function, reducing neuroinfl ammation, and modulatingneurotransmitter production. Notably, herbal medicine can mitigate the progression of NDs by regulating the gut microbiota. Therefore, an in-depth understanding of the potential mechanisms by which herbal medicine regulates the gut microbiotain the treatment of NDs can help explain the pathogenesis of NDs from a novel perspective and propose novel therapeuticstrategies for NDs. In this review, we investigate the potential neuroprotective eff ects of herbal medicine, focusing on itsability to regulate the gut microbiota and restore homeostasis. We also highlight the challenges and future research prioritiesof the integration of herbal medicine and modern medicine. As the global population ages, access to this information isbecoming increasingly important for developing eff ective treatments for these diseases.

Exploring the role and mechanisms of diallyl trisulfide and diallyl disulfide in chronic constriction-induced neuropathic pain in rats

( Gang Wang ),( Yan Yang ),( Chunfeng Wang ),( Jianzhong Huang ),( Xiao Wang ),( Ying Liu ),( Hao Wang ) 대한통증학회 2020 The Korean Journal of Pain Vol.33 No.3

Background: Garlic oil is a rich source of organosulfur compounds including diallyl disulfide and diallyl trisulfide. There have been studies showing the neuroprotective actions of these organosulfur compounds. However, the potential of these organosulfur compounds in neuropathic pain has not been explored. The present study was aimed at investigating the pain attenuating potential of diallyl disulfide and diallyl trisulfide in chronic constriction injury (CCI)-induced neuropathic pain in rats. The study also explored their pain-attenuating mechanisms through modulation of H₂S, brain-derived neurotrophin factor (BDNF) and nuclear factor erythroid 2-related factor 2 (Nrf2). Methods: The rats were subjected to CCI injury by ligating the sciatic nerve in four places. The development of neuropathic pain was measured by assessing mechanical hyperalgesia (Randall-Selittotest), mechanical allodynia (Von Frey test), and cold allodynia (acetone drop test) on 14th day after surgery. Results: Administration of diallyl disulfide (25 and 50 mg/kg) and diallyl trisulfide (20 and 40 mg/kg) for 14 days led to a significant reduction in pain in CCI-subjected rats. Moreover, treatment with these organosulfur compounds led to the restoration of H₂S, BDNF and Nrf2 levels in the sciatic nerve and dorsal root ganglia. Coadministration of ANA-12 (BDNF blocker) abolished pain attenuating actions as well as BDNF and the Nrf2 restorative actions of diallyl disulfide and diallyl trisulfide, without modulating H₂S levels. Conclusions: Diallyl disulfide and diallyl trisulfide have the potential to attenuate neuropathic pain in CCI-subjected rats possibly through activation of H₂S-BDNF-Nrf2 signaling pathway.