Stability Analysis of Grid-Connected Inverters with an LCL Filter Considering Grid Impedance

Xiao-Qiang Li,Xiao-Jie Wu,Yi-Wen Geng,Qi Zhang 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.5

Under high grid impedance conditions, it is difficult to guarantee the stability of grid-connected inverters with an LCL filter designed based on ideal grid conditions. In this paper, the theoretical basis for output impedance calculation is introduced. Based on the small-signal model, the d-d channel closed-loop output impedance models adopting the converter-side current control method and the grid-side current control method are derived, respectively. Specifically, this paper shows how to simplify the stability analysis which is usually complemented based on the generalized Nyquist stability criterion (GNC). The stability of each current-controlled grid-connected system is analyzed via the proposed simplified method. Moreover, the influence of the LCL parameters on the stability margin of grid-connected inverter controlled with converter-side current is studied. It is shown that the stability of grid-connected systems is fully determined by the d-d channel output admittance of the grid-connected inverter and the inductive component of the grid impedance. Experimental results validate the proposed theoretical stability analysis.

Development of a New Duplex Real-Time Polymerase Chain Reaction Assay for Detection of Dicer in G. gallus

( Xiao Lin Ji ),( Qi Wang ),( Yu Long Gao ),( Yong Qiang Wang ),( Li Ting Qin ),( Xiao Le Qi ),( Hong Lei Gao ),( Xiao Mei Wang ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.5

Recently, there has been a growing body of evidence showing that cellular microRNAs (miRNAs) are involved in virus-host interactions. Numerous studies have focused on analyses of the expression profiles of cellular miRNAs, but the expression patterns of Dicer, which is responsible for the generation of miRNAs, have only rarely been explored in Gallus gallus. We developed a duplex realtime reverse transcriptase polymerase chain reaction (RTPCR) assay for the relative quantification of the mRNAs of Dicer and β-actin in G. gallus. To apply this method, the expression of Dicer in avian cells after infection with avian leukosis virus subgroup J (ALV-J) was detected using our established duplex real-time RT-PCR. The duplex realtime RT-PCR assay is sufficiently sensitive, specific, accurate, reproducible, and cost-effective for the detection of Dicer in G. gallus. Furthermore, this study, for the first time, demonstrated that ALV-J can induce differential expression of Dicer mRNA in the ALV-J-infected cells.

Reusable and Efficient Polystryrene-supported Acidic Ionic Liquid Catalyst for Mononitration of Aromatic Compounds

Li Xia Li,Qi Long Ling,Zu Liang Liu,Xiao Dong Xing,Xiao Qin Zhu,Xiao Meng 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

A series of polystyrene-supported 1-(propyl-3-sulfonate)-3-methyl-imidazolium hydrosulfate acidic ionic liquid (PS-[SO3H-PMIM][HSO4]) catalysts were prepared and tested for mononitration of simple aromatics compounds with nitric acid. It was found that the reactivity of the catalysts increased with increasing [SO3HPMIM][ HSO4] content. The para-selectivity was not only related to the [SO3H-PMIM][HSO4] content but also the substituent groups in aromatics. A reaction mechanism of nitration over this new catalyst was proposed. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.

Relationship Between the SER Treatment Period and Prognosis of Patients with Small Cell Lung Cancer

Xiao, Xiao-Guang,Wang, Shu-Jing,Hu, Li-Ya,Chu, Qian,Wei, Yao,Li, Yang,Mei, Qi,Chen, Yuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Purpose: To explore the relationship between SER (time between the start of any treatment and the end of radiation therapy) and the survival of patients with limited-stage small cell lung cancer. Materials and Methods: Between 2008 and 2013, 135 cases of limited-stage small cell lung cancer (LS-SCLC) treated with consecutively curative chemoradiotherapy were included in this retrospective analysis. In terms of SER, patients were divided into early radiotherapy group (SER<30 days, n=76) and late radiotherapy group ($SER{\geq}30$ days, n=59) with a cut-off of SER 30 days. Outcomes of the two groups were compared for overall survival. Results: For all analyzable patients, median follow-up time was 23.8 months and median overall survival time was 16.8 months. Although there was no significant differences in distant metastasis free survival between the two groups, patients in early radiotherapy group had a significantly better PFS (p=0.003) and OS (p=0.000). Conclusions: A short SER may be a good prognostic factor for LD-SCLC patients treated with concurrent chemoradiotherapy.

Reusable and Efficient Polystryrene-supported Acidic Ionic Liquid Catalyst for Mononitration of Aromatic Compounds

Li, Li Xia,Ling, Qi Long,Liu, Zu Liang,Xing, Xiao Dong,Zhu, Xiao Qin,Meng, Xiao Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.10

A series of polystyrene-supported 1-(propyl-3-sulfonate)-3-methyl-imidazolium hydrosulfate acidic ionic liquid (PS-$[SO_3H-PMIM][HSO_4]$) catalysts were prepared and tested for mononitration of simple aromatics compounds with nitric acid. It was found that the reactivity of the catalysts increased with increasing $[SO_3H-PMIM][HSO_4]$ content. The para-selectivity was not only related to the $[SO_3H-PMIM][HSO_4]$ content but also the substituent groups in aromatics. A reaction mechanism of nitration over this new catalyst was proposed. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.

VAULT PROTEIN-TEMPLATED ASSEMBLIES OF NANOPARTICLES

XIAO-YING QI,XIAO HUANG,HAI LI,YUSONG WANG,Yun Xia,MEENUBHARATHI NATARAJAN,JUN WEI,Subbu S. Venkatraman,HUA ZHANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.1

Recombinant vault nanoparticles are used as stable nanoscale platforms for controlled self-assembly of various kinds of nanoparticles into the predefined multidimensional architectures. High-yield and uniform discoidal assemblies templated by vaults are constructed from gold nanospheres and quantum dots, while dimeric assemblies are formed from relatively-large gold nanocubes. The vault-templated approach appears to be mainly mediated by the surface and dimensional properties of nanoparticles while less affected by the chemical composition of nanoparticles, making it a universal strategy for fabrication of nanoassemblies with designed properties for potential applications.

Stability Analysis of Grid-Connected Inverters with an LCL Filter Considering Grid Impedance

Li, Xiao-Qiang,Wu, Xiao-Jie,Geng, Yi-Wen,Zhang, Qi The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.5

Under high grid impedance conditions, it is difficult to guarantee the stability of grid-connected inverters with an LCL filter designed based on ideal grid conditions. In this paper, the theoretical basis for output impedance calculation is introduced. Based on the small-signal model, the d-d channel closed-loop output impedance models adopting the converter-side current control method and the grid-side current control method are derived, respectively. Specifically, this paper shows how to simplify the stability analysis which is usually complemented based on the generalized Nyquist stability criterion (GNC). The stability of each current-controlled grid-connected system is analyzed via the proposed simplified method. Moreover, the influence of the LCL parameters on the stability margin of grid-connected inverter controlled with converter-side current is studied. It is shown that the stability of grid-connected systems is fully determined by the d-d channel output admittance of the grid-connected inverter and the inductive component of the grid impedance. Experimental results validate the proposed theoretical stability analysis.

Value of contrast-enhanced ultrasonography in microwave ablation treatment of symptomatic focal uterine adenomyosis

Xiao-Long Li,Jia-Xin Li,Song-Yuan Yu,Pei-Li Fan,Yun-Jie Jin,Er-Jiao Xu,Sai-Nan Guan,Er-Ya Deng,Qiu-Yan Li,Zheng-Biao Ji,Jiu-Ling Qi,Hui-Xiong Xu,China Alliance of Multi-Center Clinical Study for Ultra 대한초음파의학회 2024 ULTRASONOGRAPHY Vol.43 No.1

Purpose: This study evaluated the value of contrast-enhanced ultrasonography (CEUS) in the ultrasound-guided microwave ablation (MWA) treatment of symptomatic focal uterine adenomyosis.Methods: This retrospective study was conducted between March 2020 and January 2023, enrolling 52 patients with symptomatic focal uterine adenomyosis who had undergone MWA. All patients were examined with CEUS before and after MWA. The non-perfused volume (NPV) was compared between CEUS and dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) following ablation. Therapeutic efficacy and safety were evaluated at 3-, 6-, and 12-month follow-ups. Additionally, this study explored the correlations between pre-treatment CEUS features and a volume reduction ratio indicating sufficient ablation, defined as 50% or more at the 3-month follow-up.Results: No significant differences in NPV were noted between CEUS and DCE-MRI immediately after MWA and during follow-up (all P>0.05). At the 3-month follow-up, the median VRRs for the uterus and adenomyosis were 33.2% and 63.9%, respectively. Sufficient ablation was achieved in 69.2% (36/52) of adenomyosis cases, while partial ablation was observed in the remaining 30.8% (16/52). The identification of non-enhancing areas on pre-treatment CEUS was associated with sufficient ablation (P=0.016). At the 12-month follow-up, significant decreases were observed in both the uterine and adenomyosis volumes (all P<0.001). Dysmenorrhea and menorrhagia were significantly alleviated at 12 months, and no major complications were encountered.Conclusion: CEUS can be used to evaluate the ablation zone of focal adenomyosis that has been treated with MWA, similarly to DCE-MRI. The identification of non-enhancing areas on pretreatment CEUS indicates satisfactory treatment outcomes. Purpose: This study evaluated the value of contrast-enhanced ultrasonography (CEUS) in the ultrasound-guided microwave ablation (MWA) treatment of symptomatic focal uterine adenomyosis. Methods: This retrospective study was conducted between March 2020 and January 2023, enrolling 52 patients with symptomatic focal uterine adenomyosis who had undergone MWA. All patients were examined with CEUS before and after MWA. The non-perfused volume (NPV) was compared between CEUS and dynamic contrast-enhanced magnetic resonance imaging (DCE- MRI) following ablation. Therapeutic efficacy and safety were evaluated at 3-, 6-, and 12-month follow-ups. Additionally, this study explored the correlations between pre-treatment CEUS features and a volume reduction ratio indicating sufficient ablation, defined as 50% or more at the 3-month follow-up. Results: No significant differences in NPV were noted between CEUS and DCE-MRI immediately after MWA and during follow-up (all P>0.05). At the 3-month follow-up, the median VRRs for the uterus and adenomyosis were 33.2% and 63.9%, respectively. Sufficient ablation was achieved in 69.2% (36/52) of adenomyosis cases, while partial ablation was observed in the remaining 30.8% (16/52). The identification of non-enhancing areas on pre-treatment CEUS was associated with sufficient ablation (P=0.016). At the 12-month follow-up, significant decreases were observed in both the uterine and adenomyosis volumes (all P<0.001). Dysmenorrhea and menorrhagia were significantly alleviated at 12 months, and no major complications were encountered. Conclusion: CEUS can be used to evaluate the ablation zone of focal adenomyosis that has been treated with MWA, similarly to DCE-MRI. The identification of non-enhancing areas on pre- treatment CEUS indicates satisfactory treatment outcomes.

Predictors for Better Blood-Flow Restoration of Long-Segmental Below-the-Knee Chronic Total Occlusions after Endovascular Therapy in Diabetic Patients

Xiao-Li Song,Yue-Qi Zhu,Hai-Tao Lu,Fang Liu,Li-Ming Wei,강형근,Jun-Gong Zhao 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.6

Objective: To prospectively investigate predictors for good restoration of blood flow of below-the-knee (BTK) chronic total occlusions (CTOs) after endovascular therapy in diabetes mellitus (DM) patients. Materials and Methods: A total of 120 long-segmental (≥ 5 cm) BTK, CTOs in 81 patients who underwent recanalization were included in this study. After angioplasty, blood-flow restoration was assessed using modified thrombolysis in myocardial ischemia grades and classified as good flow (grade 3) and poor flow (grade 1/2). One hundred and six CTOs with successful recanalization were divided into a good flow group (GFG; n = 68) and poor flow group (PFG; n = 38). Multivariate logistic regression analyses were undertaken to determine independent predictors of blood-flow restoration. Receiver operating characteristic curves were constructed to determine the best cutoff value. The prevalence of target-lesion restenosis during follow-up was compared between two groups. Results: Univariate analyses suggested that CTOs in GFG were characterized by lighter limb ischemia (p = 0.03), shorter course of ischemic symptoms (p < 0.01) and lesion length (p = 0.04), more frequent use of intraluminal angioplasty (p = 0.03), and higher runoff score (p < 0.01) than those in PFG. Multivariate regression analyses suggested that distal runoffs (p = 0.001; odds ratio [OR], 10.32; 95% confidence interval [CI]: 4.082–26.071) and lesion length (p < 0.001; OR, 1.26; 95% CI: 1.091–1.449) were independent predictors for good flow restoration. Kaplan-Meier analyses at 12 months showed a higher prevalence of non-restenosis in GFG (p < 0.01). Conclusion: Distal runoffs and lesion length are independent predictors for good flow restoration for long-segmental BTK, CTOs in DM patients who receive endovascular therapy.

RNA silencing-mediated resistance is related to biotic/abiotic stresses and cellular RdRp expression in transgenic tobacco plants

( Xiao Liang Wu ),( Wen Cui Hou ),( Mei Mei Wang ),( Xiao Ping Zhu ),( Fang Li ),( Jie Dao Zhang ),( Xin Zheng Li ),( Xing Qi Guo ) 생화학분자생물학회 2008 BMB Reports Vol.41 No.5