Neutral Point Voltage-Balanced Control Method Based on Discontinuous Pulse Width Modulation for a NPC 3-level Inverter

Shaoliang An,Lu Lai,Xiangdong Sun,Yanru Zhong,Biying Ren,Qi Zhang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

A neutral point voltage-balancing control algorithm is proposed for a neutral-point-clamped (NPC) three-level photovoltaic (PV) grid-connected inverter. The mathematical model of the neutral point current was deduced. The influence on the neutral point voltage for discontinuous pulse width modulation(DPWM) methods was analyzed. Comparison of the error between feedback neutral point voltages and the hysteresis width was used to choose a DPWM method to control the neutral point voltage. Simulation and experimental results verify the correctness and validity of the proposed neutral point voltage-balancing control algorithm.

Mithun (Bos frontalis): the neglected cattle species and their significance to ethnic communities in the Eastern Himalaya - A review

Dorji, Tashi,Wangdi, Jigme,Shaoliang, Yi,Chettri, Nakul,Wangchuk, Kesang Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.11

Objective: This review consolidates the available information on the socio-economic and ecological significance of Mithun in the lives of ethnic communities in the Eastern Himalaya. Methods: Standard guidelines were followed for the review and data collection was carried out at three stages; literature search, literature screening, and literature review and analysis. Results: Records indicate a long association of Mithun with the ethnic groups. Mithun serves as a symbol of pride and local currency for barter trade in the ethnic society. Its utilities range from being used as a bride price to settling legal disputes. Several cultural festivals and local ceremonies are celebrated around this bovine. Due to its semi-wild nature, this animal also has an ecological role to conserve broad leaf sub-tropical forests. However, it remains neglected and has not received policy attention, leading to a stagnated growth. The institutions for Mithun research and development are also weak. Furthermore, the species is under threat from new diseases and habitat alteration triggered by climate change. Conclusion: Founded on the current state of knowledge, there is a need for institutional development, strengthening institutional linkages, and promoting regional cooperation among Mithun rearing countries for further research and development of this unique cattle.

An optimization on the stacking line of low-pressure axial-flow fan using the surrogate-assistant optimization method

Chuang Kong,Meng Wang,Tao Jin,Shaoliang Liu 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.11

The shape of the blade stacking line greatly influences the low-pressure axialflow fan’s operational efficiency, but there is still no fast and effective way to determine the stacking line’s optimal shape. This paper presents an automatic optimization design procedure for the blade stacking line in the low-pressure axial-flow fan based on the FINE/Design3D™ platform. The procedure combines computational fluid dynamics (CFD), surrogate model method, and genetic algorithm (GA) to execute a secondary optimization on a composite skewed-swept rotor-only axial fan blade. The results show that the static efficiency and the static pressure rise of the optimized fan respectively increase by 3.76 % and 5.82 % without stall margin decrease. The blade shape variation in skew and sweep direction reduces the tip leakage flow loss, improves the blade loading distribution, and contributes to the efficiency increment. This research provides a useful reference for the blade stacking line’s automatic optimization for the axial-flow fan.

The blade shape optimization of a lowpressure axial fan using the surrogatebased multi-objective optimization method

Chuang Kong,Meng Wang,Tao Jin,Shaoliang Liu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.1

As a core component of a fan, the blade has a decisive impact on the aerodynamic performance of a low-pressure axial flow fan. Due to the limitations of the classical fan design theory on considering the complex 3D internal flow, the spanwise distribution of blade stacking line and section profiles are usually hard to reach the best state. This paper builds a surrogate-assistant multi-objective optimization flow combined with CFD method to explore the optimum blade shape under two typical working conditions. A total of 16 parameters were selected for demonstrating the blade stacking line and section profiles, according to Morris one-ata-time sensitivity analysis. The objective and constraint functions were the fan’s total-to-static efficiency and static pressure rise, respectively. During the optimization, the surrogate models of all response functions were built using kriging models, on which the multi-objective genetic algorithm takes the exploration. The optimization results indicate that the maximum improvement of the efficiency is 1.26 % for low mass flow working condition and 5.47 % for high mass flow working condition. The optimized models tend to make the low-pressure zone distributed along the blade leading edge in the meridian view and to reduce the tip leakage vortex intensity. This paper provides a good practical demonstration of multi-objective fine optimization on the blade shape of a low-pressure axial flow fan.

Hypoxia-hindered methylation of PTGIS in endometrial stromal cells accelerates endometriosis progression by inducing CD16− NK-cell differentiation

Haiyan Peng,Lichun Weng,Shating Lei,Shuhui Hou,Shaoliang Yang,Mingqing Li,Dong Zhao 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Prostacyclin (PGI2) plays key roles in shaping the immune microenvironment and modulating vasodilation, whereas its contribution to endometriosis (EMs) remains largely unclear. Our study suggested that prostacyclin synthase (PTGIS)-dependent PGI2 signaling was significantly activated in EMs, which was involved in the hypoxic microenvironment of ectopic lesions and deficient methylation status of the PTGIS promoter. Notably, in vitro assays, hypoxia promoted PTGIS expression through DNA methyltransferase 1 (DNMT1)-mediated DNA methylation deficiency in endometrial stromal cells (ESCs); PTGIS overexpression enhanced the adhesive ability of ESCs and led to elevated PGI2 production, and PGI2 triggered CD16− (encoded by FCGR3, Fc fragment of IgG receptor IIIa) natural killer (NK)-cell differentiation through PGI2 receptor (IP, PTGIR) in an ESC/NK-cell coculture system. Our rodent model experiment suggested that treatment with the PGI2 analog iloprost and adoptive transfer of fcgr3 knockout (fcgr3−/−) NK cells aggravated EMs progression and that genetic ablation of ptgis (ptgis−/−) in ectopic lesions and treatment with the PTGIR antagonist RO1138452 partially rescued this outcome. Thus, our findings identified the contribution of PGI2 to EMs progression via enhancement of the adhesive ability of ESCs and inhibition of the activity of NK cells. We hypothesized that PGI2 is a target for EMs intervention and provide a rationale for studying pharmacological PTGIR inhibition and PTGIS genetic depletion therapies as therapeutic strategies for EMs.

Cdyl2-60aa encoded by CircCDYL2 accelerates cardiomyocyte death by blocking APAF1 ubiquitination in rats

Deng Yunfei,Zeng Xiaochen,Lv Yifei,Qian Zhiyuan,Guo Peijie,Liu Yi,Chen Shaoliang 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

The loss of cardiomyocytes (CMs) after myocardial infarction (MI) is widely acknowledged to initiate the development of heart failure (HF). Herein, we found that circCDYL2 (583 nt) derived from chromodomain Y-like 2 (Cdyl2) is significantly upregulated in vitro (oxygen-glucose deprivation (OGD)-treated CMs) and in vivo (failing heart post-MI) and can be translated into a polypeptide termed Cdyl2-60aa (~7 kDa) in the presence of internal ribosomal entry sites (IRES). Downregulation of circCDYL2 significantly decreased the loss of OGD-treated CMs or the infarcted area of the heart post-MI. Additionally, elevated circCDYL2 significantly accelerated CM apoptosis via Cdyl2-60aa. We then discovered that Cdyl2-60aa could stabilize protein apoptotic protease activating factor-1 (APAF1) and promote CM apoptosis; heat shock protein 70 (HSP70) mediated APAF1 degradation in CMs by ubiquitinating APAF1, which Cdyl2-60aa could competitively block. In conclusion, our work substantiated the claim that circCDYL2 could promote CM apoptosis via Cdyl2-60aa, which enhanced APAF1 stability by blocking its ubiquitination by HSP70, suggesting that it is a therapeutic target for HF post-MI in rats.

Convenient and Robust Route to Photoswitchable Hierarchical Liquid Crystal Polymer Stripes via Flow-Enabled Self-Assembly

Li, Xiao,Li, Bo,He, Ming,Wang, Wei,Wang, Tianjie,Wang, Aurelia,Yu, Jiwoo,Wang, Zhonglin,Hong, Suck Won,Byun, Myunghwan,Lin, Shaoliang,Yu, Haifeng,Lin, Zhiqun American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.5

<P>Hierarchically arranged stripes of photoswitchable liquid crystal polymers (LCPs) containing azobenzene moieties were conveniently crafted via a flow-enabled self-assembly (FESA). Interestingly, by subjecting a drop of LCP solution to dry in a restricted geometry comprising two nearly parallel plates with a stationary upper plate and a movable lower plate that programmably traveled in a 'stop -and-move' manner during the FESA process, photoswitchable LCP stripes were yielded, displaying two modes of deposition, namely, periodic primary stripes of large dimensions and regularly spaced secondary stripes of small dimensions situated between adjacent, primary stripes (i.e., forming hierarchical LCP stripes). Notably, these hierarchical azobenzene moieties-containing stripes demonstrated sequential photoinduced reversible phase transition (i.e., photoswitching) due to the thickness difference between primary and secondary stripes. A UV light-induced expansion effect. was observed on the LCP stripes. Clearly, such rapid creation of hierarchical stripes by FESA represents a robust means of organizing polymers, nanoparticles, colloids, DNA, etc. into complex yet ordered patterns over a large area in a simple and controllable manner for potential use in surface relief grating, photoactuators, photoswitchable devices, antifake labels, etc.</P>