Permanent magnet temperature estimation of high power density permanent magnet synchronous machines by considering magnetic saturation

Jian Gao,Chengxu Li,Wenjuan Zhang,Shoudao Huang 전력전자학회 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.12

This paper develops a method for permanent magnet (PM) temperature estimation in high power density permanent magnet synchronous machines (PMSMs) by considering magnetic saturation. Most of the previous methods in the literature are based on unsaturation. In this paper, the temperature estimation method of PMs is improved by adding a saturation coefficient. Once a machine is assembled, the inner and outer PM surfaces cannot be seen. Thus, it is impossible to realize visualization measurement of the permanent magnet temperature distribution. In this case, temperature sensors attached to the PM cam be used. However, the cost and robustness need to be considered. Therefore, in this paper, by solving a magnetic–thermal coupling finite element model, the temperature field distribution of a high power density PMSM is obtained. Then, an experimental platform is built to verify the model. Finally, the model is used to verify the reliability of the modified estimation method.

Visibility of CT Early Ischemic Change Is Significantly Associated with Time from Stroke Onset to Baseline Scan beyond the First 3 Hours of Stroke Onset

Jian Gao,Mark W. Parsons,Hiroyuki Kawano,Christopher R. Levi,Tiffany-Jane Evans,Longting Lin,Andrew Bivard 대한뇌졸중학회 2017 Journal of stroke Vol.19 No.3

Background and Purpose Non-contrast brain computed tomography (NCCT) remains the most common imaging modality employed to select patients for thrombolytic therapy in acute ischemic stroke. The current study used the Alberta Stroke Program Early CT Score (ASPECTS) to identify early ischemic changes on brain NCCT imaging with the aim to investigate whether a relationship exists between time from symptoms onset to NCCT with the presence of early ischaemic change quantified by ASPECTS. Methods We studied 1,329 ischemic stroke patients who had NCCT within 8 hours of stroke onset. Patients were assessed to see if they had any ASPECTS lesion and if the rate of patients with a lesion increased with time using logistic regression. Results 30% patients had an ASPECTS <10 within the first 3 hours from symptom onset. Within the first 3 hours, the odds for a CT change (ASPECTS <10) per minute of time was 1.00 with 95% confidence interval (CI) (0.99 to 1.00) (P=0.266). After 3 hours, there was a significant increase in odds of ASPECTS <10 with increasing time. The odds of being ASPECTS positive increased 1% (odds ratio=1.01) per 1 minute of time with 95% CI (1.00 to 1.01) (P=0.002). Conclusions We have identified that prior to first 3 hours of stroke there was no effect of time on odds of CT ischemic change; after the first 3 hours of stroke the odds increased with increasing time to CT scan. The occurrence of early ischemic change may be a marker of time from stroke onset rather than severity.

A putative pathogen-resistant regulatory pathway between MicroRNAs and candidate target genes in maize

Jian Gao,Mao Luo,Chun Zhang,Hua Peng,Haijian Lin,Yaou shen,Maojun Zhao,Guangtang Pan,Zhiming Zhang 한국식물학회 2015 Journal of Plant Biology Vol.58 No.4

MicroRNAs (miRNAs) are a family of small non-coding RNAs that, in most cases, negatively regulate gene expression at the post-transcriptional level. Plant miRNAs have been implicated in developmental processes and adaptation to environmental stress including biotic and abiotic stresses. Here, we report a comprehensive analysis of miRNAs and associated target genes under banded leaf and sheath blight (BLSB) stress caused by R. solani in maize. Eight differentially expressed miRNAs were randomly selected from deep sequencing results and validated by qRT-PCR together with their putative target genes, most of which are transcription factors as well as metabolic genes involved in auxin signaling. The results revealed that majorities of the analyzed miRNAs show an inverse correlation with their corresponding predicted target genes. In addition, a putative regulatory network of miRNAs-mRNAs responsive to R. solani was constructed. This study provides insight into the regulatory functions of miRNAs, thereby expanding our knowledge of the molecular mechanisms of pathogen resistance.

SKEW CYCLIC CODES OVER Fp + vFp

Jian Gao 한국전산응용수학회 2013 Journal of applied mathematics & informatics Vol.31 No.3

In this paper, we study a special class of linear codes, calledskew cyclic codes, over the ring R = Fp + vFp, where p is a prime numberand v2 = v. We investigate the structural properties of skew polynomialring R[x,θ] and the set R[x,θ]=(xn -1). Our results show that these codesare equivalent to either cyclic codes or quasi-cyclic codes. Based on thisfact, we give the enumeration of distinct skew cyclic codes over R.

Causing Troubles Elsewhere: The Shining Path and Its International Networks, 1980-1993

Jian Gao 한국라틴아메리카학회 2021 라틴아메리카연구 Vol.34 No.1

As a Maoist organization, the Shining Path inflicted terror and violence in Peru throughout the 1980s and early 1990s. Facing strong domestic resistance and vehement international condemnation, this militant group was never able to establish a communist regime in Peru as its leader Abimael Guzmán had envisioned. With little domestic support and amid frequent international denouncements, the Shining Path looked beyond the Peruvian borders for trouble and capitalized on its transnational connections to enhance its survival. Its global networks spanned the Americas, Europe, and even reached to North African countries like Libya, which lacked connections to Peru or communist countries. While the Shining Path was unable to create a massive communist regime as it wished, it did, however, generate fear and violence within Peru and beyond. From this perspective, the organization altered its strategic political goal to the process goal of effecting chaos and fear among the global communities. Ironically, the supposed allies of Shining Path, according to the Maoist ideology, actually turned against the communist organization-peasants from rural Peru resented the disruption of their lives caused by Shining Path, while China, the cradle of Maoism, along with the Soviet Union and Cuba, condemned the guerrillas as terrorists. By examining the expansive transnational sources generated by the Foreign Broadcast Information Service of the Central Intelligence Agency (CIA) and the official newspaper of the Chinese government, Renmin Ribao, this paper contributes to the recent and growing historiography that has analyzed diverse political movements in Latin America beyond their immediate geographical origins.

Research on the Performance-Based Parameter of Horizontal Visor of Certain Wall Relative to the Sun Zenith Angle

Jian Gao,Jian Tang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.4

The horizontal shading is one part of the buildings, outside shading systems. Relative sun elevation angle to the wall Φ , and relative sun azimuthal angle to the wall γ are introduced. The optimum width for the southern shading of local buildings can be calculated according to the law of solar altitude change over time. In this research, relative sun elevation angle to the wall Φ is key for design parameters determination of horizontal shading component. The present study optimized the design of the horizontal shading on the basis of the traditional design. The new design of the visor could still shade the exceeding sunlight in summer, but at the same time allow enough sunshine in winter. This design is environmental-friendly, energy and material-saving.

Inhibition of Indoleamine 2,3-Dioxygenase Enhances the Therapeutic Efficacy of Immunogenic Chemotherapeutics in Breast Cancer

Jian Gao,Fusheng Deng,Weidong Jia 한국유방암학회 2019 Journal of breast cancer Vol.22 No.2

Purpose: Breast cancer has become a major public health threat in the current society. Anthracycline doxorubicin (DOX) is a widely used drug in breast cancer chemotherapy. We aimed to investigate the immunogenic death of breast tumor cells caused by DOX, and detect the effects of combination of DOX and a small molecule inhibitor in tumor engrafted mouse model. Methods: We used 4T1 breast cancer cells to examine the anthracycline DOX-mediated immunogenic death of breast tumor cells by assessing the calreticulin exposure and adenosine triphosphate and high mobility group box 1 release. Using 4T1 tumor cell-engrafted mouse model, we also detected the expression of indoleamine 2,3-dioxygenase (IDO) in tumor tissues after DOX treatment and further explored whether the specific small molecule IDO1 inhibitor NLG919 combined with DOX, can exhibit better therapeutic effects on breast cancer. Results: DOX induced immunogenic cell death of murine breast cancer cells 4T1 as well as the upregulation of IDO1. We also found that treatment with NLG919 enhanced kynurenine inhibition in a dose-dependent manner. IDO1 inhibition reversed CD8+ T cell suppression mediated by IDO-expressing 4T1 murine breast cancer cells. Compared to the single agent or control, combination of DOX and NLG919 significantly inhibited the tumor growth, indicating that the 2 drugs exhibit synergistic effect. The combination therapy also increased the expression of transforming growth factor-β, while lowering the expressions of interleukin-12p70 and interferon-γ. Conclusion: Compared to single agent therapy, combination of NLG919 with DOX demonstrated better therapeutic effects in 4T1 murine breast tumor model. IDO inhibition by NLG919 enhanced the therapeutic efficacy of DOX in breast cancer, achieving synergistic effect.

The effect of A-site element on CO2 resistance of O2-selective La-based perovskite hollow fibers

Jian Gao,Yutai Lun,Yadi Hu,Zijian You,Xiaoyao Tan,Shaobin Wang,Jaka Sunarso,Shaomin Liu 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

Oxygen-selective mixed ionic-electronic conducting (MIEC) ceramic membrane technology enables clean coal combustion and membrane reactor for green chemical synthesis. To be practical in these applications that involve CO2 presence, the membrane materials should have simultaneously high CO2 resistance and oxygen permeation fluxes. This work probed these properties for the perovskite oxide family of La0.6X0.4FeO3-d (X = Mg, Ca, Sr, or Ba), i.e., La0.6Mg0.4FeO3-d (LMF), La0.6Ca0.4FeO3-d (LCF), La0.6Sr0.4FeO3-d (LSF), and La0.6Ba0.4FeO3-d (LBF) in the hollow fiber membrane geometry that is highly suitable for industrial application. LCF hollow fiber displayed the best balance in CO2 resistance and oxygen permeation fluxes.

Synthesis and Characterization of WC-Co Nanosized Composite Powders With in situ Carbon and Gas Carbon Sources

Qiumin Yang,Jiangao Yang,Hailin Yang,Wei Su,Jianming Ruan 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.4

This study presented nanosized WC-Co composite powders synthesized using a one-step reduction-carbonization process with a combination of CH4/H2 as a gas carbon source and soluble starch as an in situ carbon source. The results of carbon analysis and X-ray diffraction revealed that WC-Co nanocomposite powders with a pure WC and Co phase could be obtained at 1100 °C after 0.5 h. A higher gas flow ratio of CH4/H2 during the reduction-carbonization process led to a higher total carbon content of the sample. A field emission scanning electron microscope confirmed that the particles in the WC-6 wt% Co composite powders had the lowest average size of 43 nm with equiaxed shapes. A sintering neck was observed in the WC-3 wt% Co composite powders whereas faceted particles were found in the WC-12 wt% Co composite powders. Moreover, this method has advantages of simple processing, rapid synthesis and good applicability in potential industry application.

Influence of Drawing and Annealing on the Crystallization, Viscoelasticity, and Mechanical Properties for Middle-molecular-weight Polyethylene Fishing Monofilaments

Wenwen Yu,Lumin Wang,Jiangao Shi 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

The influence of drawing and annealing on the crystallization, viscoelasticity and mechanical properties for middle-molecular-weight polyethylene (MMWPE) fishing monofilaments was investigated. It was found that the drawing procedure had a positive effect on the crystallization of the MMWPE fishing monofilaments. Meanwhile, the glass transition temperature of the MMWPE monofilaments shifted to higher temperature, and the α-relaxation associated with crystalline phases became higher and broader with the increase in the drawing ratio. Moreover, the breaking strength of MMWPE fishing monofilaments can be effectively improved by increasing the drawing ratio. Meanwhile, the knot strength increased first and then decreased. However, the increase in annealing temperature improved the knot strength. With increasing annealing temperature, the orientation factor decreased and induced the γ-relaxation peak at high magnitude. This indicated that the amorphous structure could become disordered during annealing treatment. In addition, the annealing temperature can clearly influence the working temperature dependence of the stress-strain behavior. When the working temperature rose from 20 oC to 30 oC, the MMWPE monofilaments after annealing at 120 oC exhibited low modulus loss due to their high α- transition temperature. Thus, an important method for improving the mechanical properties by controlling the drawing and annealing conditions was established.