Modeling and Analysis of Harmonic Resonance in Microgrid and Research of Active Harmonic Resistance Method

Cheng Nie,Wanjun Lei,Huajia Wang,Kai Zhang,Yue Wang 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

In the microgrid, the capacitive element such as compensation capacitor may resonance with the line inductance in harmonic frequency, furthermore serious harmonic resonance may endanger the system. In this paper, resonance mode analysis (RMA) method is used to analysis the harmonic resonance in the microgrid. To suppress the amplified of harmonic current near resonance frequency, an improved current control method for active harmonic resistance (AHR) is proposed. Simulation and experimental results reveal that the proposed method can suppress the resonance in the microgrid effectively.

Shorter Distance Between the Nodule and Capsule has Greater Risk of Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma

Wang, Qiu-Cheng,Cheng, Wen,Wen, Xin,Li, Jie-Bing,Jing, Hui,Nie, Chun-Lei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Background: The purpose of this study was to assess the relationship between different sonographic features of papillary thyroid carcinoma (PTC) on high-frequency ultrasound and cervical lymph node metastasis (CLNM). Materials and Methods: We enrolled 548 patients who underwent initial surgery for PTC between May 2011 and December 2012 in our hospital at diagnosis. The sonographic features of 513 PTC nodules in 513 eligible patients, who had single PTC nodules in their thyroid glands, were retrospectively investigated. All patients with a suspect malignant nodule (d<0.5cm) among multiple nodules were initially diagnosed by fine-needle aspiration biopsy (FNAB) to ascertain if the suspect nodule was PTC. The final diagnosis of all the thyroid nodules and existence of CLNM were based on postoperative pathology. Patients were divided into two groups: a positive group with CLNM (224 nodules) and a negative group without CLNM (289 nodules). The following factors were investigated: gender, age, echogenicity, echotexture, size, shape, location, margin, contour, calcification morphology, distance between the nodule and pre- or post-border of the thyroid capsule, vascularity and the differences between the two groups. Results: Correlation analysis showed that shorter distances between the nodule and pre- or postborder of thyroid capsule resulted in greater risk of CLNM (Spearman correlation coefficient=-0.22, p<0.0001). The significant factors in multivariate analysis were age<45yrs, larger size (d>1cm), "wider than tall" shape, extrathyroid extension and mixed flow (internal and peripheral) (p<0.05, OR=0.406, 2.093, 0.461, 1.610, 1.322). Conclusions: Significant sonographic features of PTC nodules in preoperative high-frequency ultrasound are crucial for predicting CLNM.

Radon-induced demethylation of Cdk2 CpG island in the rat lung

Cheng Wu,Qiu Chen,Jian Tong,Xin Xie,Fengmei Cui,Yang Jiao,Dandan Qi,Jihua Nie,Tom K. Hei,Qisheng Jiang 한국유전학회 2014 Genes & Genomics Vol.36 No.6

Radon exposure has been linked to lung carcinogenesisin both human and animal studies. The identificationof sequential changes in DNA methylation duringtumour progression and the elucidation of their interplaywith genetic changes will broaden our molecular understandingof this disease. Rats were exposed to 120 or 400working level months (WLM) of radon, lung pathologicalchanges were examined by haematoxylin and eosin staining,lung single cell suspension cell cycles were detected byflow cytometry, lung cell cycle regulated gene (Cdkn2a,P53, Cdk4/2, Mdm4/2 and Rb1 genes) expression wasquantified by real-time PCR and methylation of CpG islandsin the promoters of cell cycle-regulated genes were detectedby bisulfite sequencing PCR. The alveolar walls of rat lungsafter exposured to radon exhibited papillae and the lungbronchial epithelial cells stained positively for proliferatingcell nuclear antigen. The bronchial epithelial cells displayedsome hyperplasia after challenged by 400 WLM of radon. Moreover, G1 arrest decreased; Rb1, Mdm2/4, and Cdk2/4expression decreased and Cdk2 was demethylated at thesecond and sixth CpG loci from base pairs 3092704 to3092953 of chromosome 7. Cdk2 demethylation may beapplicable as a biomarker of early lung damage that wasinduced by radon and other environmental carcinogens.

经管类本科专业公司运营实战实验室建设研究

聂希刚(Nie Xi-Gang),陈荣庚(Cheng Rong-Geng),李强(Li Qiang),高巍(Gao Wei) 동북아시아문화학회 2009 동북아시아문화학회 국제학술대회 발표자료집 Vol.2009 No.5월

AR model-based crosstalk cancellation method for operational transfer path analysis

Wei Cheng,Yan Zhu,Xuefeng Chen,Chao Song,Le Zhang,Lin Gao,Yilong Liu,Zelin Nie,Hongrui Cao,Yang Yang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3

To reduce the crosstalk effects between the signals at reference points in operational transfer path analysis (OTPA) and improve the reliability of solutions, a novel OTPA method based on auto-regressive (AR) model is proposed in this paper. The key to this method is to obtain the power spectrum by AR model for estimating the prior transmissibility function matrix. Firstly, in view of the lack of noise reduction process in conventional crosstalk cancellation method, singular value decomposition (SVD) is applied to reduce the noise of original signals. Secondly, Burg algorithm is used to calculate AR model parameters. Thirdly, auto-power spectrum and cross-power spectrum are obtained by AR model and the periodogram method respectively. Fourthly, the transmissibility function matrix is obtained by Landweber iterative method based on corrected signals at reference points. Finally, the proposed method can significantly reduce the crosstalk effects, resulting in more accurate evaluation of transfer path contributions. Generally, this study can provide accurate and reliable evidences for vibration & noise monitoring and reduction for mechanical systems, and thus benefit for the active control of vibration & noise.

Balance Between User Comfort and Energy Consumption of Two-timescale Optimization and Control in Majorization Order

Zelin Nie,Wei Cheng,Guanghui Zhou,Xuefeng Chen,Chao-Bo Yan,Feng Gao 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.6

Under the unique environment of high humidity and high salinity of nuclear power plants, the environment should be improved to ensure staff comfort and equipment safe operation. Meanwhile, because of energy shortage, it is of great significance for building to save energy and reduce consumption. This paper first introduces the concept of Majorization to ensure user comfort with control smoothness, improving the existing two-timescale heating, ventilation, and air conditioning (HVAC) optimization model. Then, considering energy consumption, this paper formulates a multi-objective programming (MOP) problem with the objective to seek a balance between user comfort and energy consumption. The MOP model is solved by constructing the trade-off curve, where a subobjective with Majorization is also a MOP problem nested, which can be solved more simply using the characteristic of two-timescale HVAC optimization. The numerical results demonstrate the Pareto optimal solutions and the better energy-saving effect compared with the existing two-timescale model.

A Fast-Transient Repetitive Control Strategy for Programmable Harmonic Current Source

Lei, Wanjun,Nie, Cheng,Chen, Mingfeng,Wang, Huajia,Wang, Yue The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

The repetitive control (RC) strategy is widely used in AC power systems because of its high performance in tracking period signal and suppressing steady-state error. However, the dynamic response of RC is determined by the fundamental period delay $T_0$ existing in the internal model. In the current study, a ($nk{\pm}i$)-order harmonic RC structure is proposed to improve dynamic performance. The proposed structure has less data memory and can improve the tracking speed by n/2 times. $T_0$ proves the effectiveness of the ($nk{\pm}i$)-order RC strategy. The simulation and experiments of ($6k{\pm}1$)-order and ($4k{\pm}1$)-order RC strategy used in the voltage source inverter is conducted in this study to control the harmonic current source, which shows the validity and advantages of the proposed structure.

Experimental Study on Sustained-release 5-Fluorouracil Implantation in Canine Peritoneum and Para-aortic Abdominalis

Wei, Guo,Nie, Ming-Ming,Shen, Xiao-Jun,Xue, Xu-Chao,Ma, Li-Ye,Du, Cheng-Hui,Wang, Shi-Liang,Bi, Jian-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Objective: To observe local and systemic toxicity after sustained-release 5-fluorouracil (5-Fu) implantation in canine peritoneum and para-aortic abdominalis and the changes of drug concentration in the local implanted tissue with time. Methods: 300 mg sustained-release 5-Fu was implanted into canine peritoneum and para-aorta abdominalis. Samples were taken 3, 5, 7 and 10 days after implantation for assessment of changes and systemic reactions. High performance liquid chromatography was applied to detect the drug concentrations of peritoneal tissue at different distances from the implanted site, lymphatic tissue of para-aortic abdominalis, peripheral blood and portal venous blood. Results: 10 days after implantation, the drug concentrations in the peritoneum, lymphatic tissue and portal vein remained relatively high within 5 cm of the implanted site. There appeared inflammatory reaction in the local implanted tissue, but no visible pathological changes such as cell degeneration and necrosis, and systemic reaction like anorexia, nausea, vomiting and fever. Conclusions: Sustained-release 5-Fu implantation in canine peritoneum and para-aortic abdominalis can maintain a relatively high tumour-inhibiting concentration for a longer time in the local implanted area and portal vein, and has mild local and systemic reactions. Besides, it is safe and effective to prevent or treat recurrence of gastrointestinal tumours and liver metastasis.

Evaluating and predicting net energy value of wheat and wheat bran for broiler chickens

Ning Ran,Cheng Zichen,Liu Xingbo,Ban Zhibin,Guo Yuming,Nie Wei 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.11

Objective: It is crucial to accurately determine the net energy (NE) values of feed ingredients because the NE system is expected to be applied to the formulation of broilers feed. The NE values of 5 wheat and 5 wheat brans were determined in 12-to 14-day old Arbor Acres (AA) broilers with substitution method and indirect calorimetry method. Methods: A total of 12 diets, including 2 reference diets (REF) and 10 test diets (5 wheat diets and 5 wheat bran diets) containing 30% of test ingredients, were randomly fed to 864 male AA birds with 6 replicates of 12 birds per treatment. These birds were used to determine metabolizable energy (ME) (8 birds per replicate) in the chicken house and NE (4 birds per replicate) in the chamber respectively at the same time. After a 4-d dietary and environment adaptation period, growth performance, energy values, energy balance and energy utilization were measured during the following 3 d. Multiple linear regression analyses were further performed to generate prediction equations for NE values based on the chemical components and ME values. The NE prediction equation were also validated on another wheat diet and another wheat bran diet with high correlation (r = 0.98, r = 0.75). Results: The NE values of 5 wheat and 5 wheat bran samples are 9.34, 10.02, 10.27, 11.33, and 10.49 MJ/kg, and 5.37, 5.17, 4.87, 5.06, and 4.88 MJ/kg DM, respectively. The equation with the best fit were NE = 1.968AME–0.411×ADF–14.227 (for wheat) and NE = –0.382×CF –0.362×CP–0.244×ADF+20.870 (for wheat bran). Conclusion: The mean NE values of wheat and wheat bran are 10.29 and 5.07 MJ/kg DM in AA broilers. The NE values of ingredients could be predicted by their chemical composition and energy value with good fitness. Objective: It is crucial to accurately determine the net energy (NE) values of feed ingredients because the NE system is expected to be applied to the formulation of broilers feed. The NE values of 5 wheat and 5 wheat brans were determined in 12-to 14-day old Arbor Acres (AA) broilers with substitution method and indirect calorimetry method.Methods: A total of 12 diets, including 2 reference diets (REF) and 10 test diets (5 wheat diets and 5 wheat bran diets) containing 30% of test ingredients, were randomly fed to 864 male AA birds with 6 replicates of 12 birds per treatment. These birds were used to determine metabolizable energy (ME) (8 birds per replicate) in the chicken house and NE (4 birds per replicate) in the chamber respectively at the same time. After a 4-d dietary and environment adaptation period, growth performance, energy values, energy balance and energy utilization were measured during the following 3 d. Multiple linear regression analyses were further performed to generate prediction equations for NE values based on the chemical components and ME values. The NE prediction equation were also validated on another wheat diet and another wheat bran diet with high correlation (r = 0.98, r = 0.75).Results: The NE values of 5 wheat and 5 wheat bran samples are 9.34, 10.02, 10.27, 11.33, and 10.49 MJ/kg, and 5.37, 5.17, 4.87, 5.06, and 4.88 MJ/kg DM, respectively. The equation with the best fit were NE = 1.968AME–0.411×ADF–14.227 (for wheat) and NE = –0.382×CF–0.362×CP–0.244×ADF+20.870 (for wheat bran).Conclusion: The mean NE values of wheat and wheat bran are 10.29 and 5.07 MJ/kg DM in AA broilers. The NE values of ingredients could be predicted by their chemical composition and energy value with good fitness.

Enhancing the Magnetic Plasmon Resonance of Three-Dimensional Optical Metamaterials via Strong Coupling for High-Sensitivity Sensing

Chen, Jing,Nie, Hai,Peng, Cheng,Qi, Shibin,Tang, Chaojun,Zhang, Ying,Wang, Lianhui,Park, Gun-Sik IEEE 2018 Journal of Lightwave Technology Vol.36 No.16

<P>We report an effective method to enhance and modify the magnetic plasmon (MP) resonance in three-dimensional (3D) optical metamaterials consisting of periodic arrays of silver vertical split-ring resonators (VSRRs) for high-sensitivity sensing. By positioning the 3D metamaterials above a thick silver film separated by a silica dielectric spacer layer, the strong coupling between the MP resonance in the VSRRs and the surface plasmons polaritons (SPPs) propagating on the silver film can be realized and gives rise to an ultra-narrowband hybrid MP mode with a huge enhancement of magnetic fields. For the coupling to happen, the magnetic field direction of the SPPs should be parallel to the magnetic moment induced in the VSRRs. More importantly, because the ultra-narrowband hybrid MP mode is extremely sensitive to the surrounding media, the sensitivity and the figure of merit (FOM) of the 3D metamaterials can reach as high as 700 nm/RIU and 170, respectively, suggesting that the proposed 3D metamaterials hold potential applications in label-free biomedical sensing.</P>