http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Effects of some factors on the thermal-dissipation characteristics of high-power LED packages
Ji, Peng Fei,Moon, Cheol-Hee The Korean Infomation Display Society 2012 Journal of information display Vol.13 No.1
Decreasing the thermal resistance is the critical issue for high-brightness light-emitting diodes. In this paper, the effects of some design factors, such as chip size (24 and 35 mil), substrate material (AlN and high-temperature co-fired ceramic), and die-attach material (Ag epoxy and PbSn solder), on the thermal-dissipation characteristics were investigated. Using the thermal transient method, the temperature sensitivity parameter, $R_{th}$ (thermal resistance), and junction temperature were estimated. The 35-mil chip showed better thermal dissipation, leading to lower thermal resistance and lower junction temperature, owing to its smaller heat source density compared with that of the 24-mil chip. By adopting an AlN substrate and a PbSn solder, which have higher thermal conductivity, the thermal resistance of the 24-mil chip can be decreased and can be made the same as that of the 35-mil chip.
Ji-Peng Dong,Jing-Guang Sun,Yong Guo,Shen-Min Song 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4
In order to meet the needs of high-precision guidance for missile-guided maneuvering targets in the presence of towed bait interference, this paper proposes a new guidance strategy based on heading angle method and parallel approaching method. Its main idea: a suitable angle is determined by heading angle method which of the missile trajectory is above that of the towing bait. Meanwhile, the accurate interception of missiles to targets is guaranteed by parallel approaching method. Firstly, system models of missile and target with towed decoy are established. Then, considering unknown bounded system disturbances, a controller is given based on sliding mode, back-stepping method. Furthermore, to solve the input saturation problem, an anti-saturation controller is given using adaptive and back-stepping sliding mode methods. Finally, strict proofs of the two controllers are given using Lyapunov stability theory, and simulations are carried out to verify the effectiveness of the two controllers.
Effects of some factors on the thermal-dissipation characteristics of high-power LED packages
Peng Fei Ji,문철희 한국정보디스플레이학회 2012 Journal of information display Vol.13 No.1
Decreasing the thermal resistance is the critical issue for high-brightness light-emitting diodes. In this paper, the effects of some design factors, such as chip size (24 and 35 mil), substrate material (AlN and high-temperature co-fired ceramic), and dieattach material (Ag epoxy and PbSn solder), on the thermal-dissipation characteristics were investigated. Using the thermal transient method, the temperature sensitivity parameter, Rth (thermal resistance), and junction temperature were estimated. The 35-mil chip showed better thermal dissipation, leading to lower thermal resistance and lower junction temperature, owing to its smaller heat source density compared with that of the 24-mil chip. By adopting an AlN substrate and a PbSn solder,which have higher thermal conductivity, the thermal resistance of the 24-mil chip can be decreased and can be made the same as that of the 35-mil chip.
De novo malignancy after liver transplantation
Peng Ji Gao,Jie Gao,Zhao Li,Zhi Ping Hu,Ji Ye Zhu 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.88 No.4
Purpose: The aim of this study is to evaluate the incidence of de novo malignancy after liver transplantation (LT) and compare with those among the general Chinese population. Methods: A total of 466 patients who had a minimum follow-up time of 6 months were enrolled in the study. All data of medical records and follow up were retrospectively reviewed. Results: The incidence rate of de novo malignancy was 3.0% (14 in 466 patients). The median elapsed time from transplant to the diagnosis of de novo malignancy was 42 months (range, 6 to 106 months). The cumulative risk for development of de novo malignancy was 1.6%, 2.7%, and 8.2% at 3, 5 and 10 years after LT, respectively. The patients were all male. The types of de novo tumors included digestive system tumor (8 in 14), lung cancer (2 in 14), urologic neoplasm (2 in 14), and hematologic malignant tumor (2 in 14). Over a mean follow-up of 24 months after diagnosis of de novo malignancy, 7 patients (50.0%) died; the overall 5-year patient survival rate was 54.5%. The relative risk of malignancy following LT was 9.5 folds higher than the general Chinese population. Conclusion: The relative risk of malignancy following LT was much higher than the general Chinese population. Digestive system tumor is the most common type of de novo malignancy after LT in China.
Microstructure of Antarctic Krill (Euphausia suberba) Cuticle
Yuanhuai Peng,Wei Ji,Hongwu Ji 한국해양과학기술원 2022 Ocean science journal Vol.57 No.2
In this study, the microstructure of Antarctic krill cuticle was deeply investigated using scanning electron microscope (SEM). The krill cuticles were treated with clean water, dilute hydrochloric acid solution and dilute sodium hydroxide solution to remove the adhesive substances, inorganic salts and protein, respectively. The organic substances were removed by sintering the cuticle in a muffle furnace to obtain the inorganic salts. The resulting cuticle of Antarctic krill was then observed under SEM and it was found that the cuticle has a hierarchical structure in which the α-crystal chitin fibers, with chitin spheres, extended from the pore canals, thus shaping layers; multiple stacked layers formed the three-dimensional structure; the inorganic salts were sparsely distributed in the cuticle; protein was wrapped around the surfaces of the chitin fiber bundles and the crystals of inorganic salts. These structural investigations revealed the interrelation among the main components of Antarctic krill cuticle. This study and following studies will be helpful in understanding the relationship between the forms of fluorine in Antarctic krill cuticle and its structural changes during postmortem storage.
A20 ameliorates disc degeneration by suppressing mTOR/BNIP3 axis-mediated mitophagy
Peng Xin,Zhang Cong,Gao Jia-Wei,Wang Feng,Bao Jun-Ping,Zhou Zhi-Min,Sun Rui,Ji Hang-Yu,VLF Cabral,Wu Xiao-Tao 한국유전학회 2023 Genes & Genomics Vol.45 No.5
Background The pathological mechanism of intervertebral disc degeneration (IDD) is an unanswered question that we are committed to exploring. A20 is an anti-inflammatory protein of nucleus pulposus (NP) cells and plays a protective role in intervertebral disc degeneration. Objective This study aims to investigate the molecular mechanism by which A20 attenuates disc degeneration. Methods The proteins of interest were measured by immunoblotting, immunofluorescence, ELISA assay, and immunohistochemical technique to conduct related experiments. Immunofluorescence assays and mitochondrial membrane potential (JC-1) were used to assess mitophagy and mitochondrial fitness, respectively. Results Here, we demonstrated that A20 promoted mitophagy, attenuated pyroptosis, and inhibited the degradation of the extracellular matrix, consequently significantly ameliorating disc degeneration. Mechanistically, A20 reduces pyroptosis and further suppresses cellular mTOR activity. On the one hand, A20-induced mTOR inhibition triggers BNIP3-mediated mitophagy to ensure mitochondrial fitness under LPS stimulation, as a result of mitigating mitochondrial dysfunction induced by LPS. On the other hand, A20-induced mTOR inhibition reduces the loss of mitochondrial membrane potential and the generation of Mitochondrial ROS. Conclusion The study revealed that A20 promotes BNIP3-mediated mitophagy by suppressing mTOR pathway activation against LPS-induced pyroptosis.