전환기 중국의 부패와 반부패문제 연구

하증과 ( Zeng Ke He ) 서강대학교 동아연구소 2003 東亞 硏究 Vol.- No.44

Influence of overhead transmission line on grounding impedance measurement of substation

Zeng, Rong,He, Jinliang,Lee, Jaebok,Chang, S.,Tu, Youping,Gao, Yanqing,Zou, Jun,Guan, Zhicheng IEEE 2005 IEEE transactions on power delivery Vol.20 No.2

How to precisely measure the grounding impedance of large-scale substations is a fundamental guarantee for the safe operation of power systems. If the ground wires were connected to the grounding grid, these ground wires would shunt a part of the injected measuring current and allow the measured grounding impedance to be smaller than the actual impedance of the grounding system. Based on an actual 500-kV grounding system, this paper discusses how to analyze the influence of the overhead ground wire on the measured grounding impedance and how to obtain the real grounding impedance of the grounding system. A numerical analysis model considering the grounding system, the transmission lines, towers, and their grounding devices, based on the multilayer soil model analyzed from field test data of apparent soil resistivity, was constructed to analyze the influence of ground wires and tower grounding resistances on grounding impedance, and the general effects of different parameters, such as tower impedance, grounding impedance, and circuits of transmission lines, were analyzed. The real grounding impedance of the substation with connected overhead ground wires was validated, and some useful results have been obtained, based on the field-measured values and numerical analysis.

Research on the Oxidation-Protective Coatings for Carbon/Carbon Composites

He-Jun Li,Qian-Gang Fu,Jian-Feng Huang,Xie-Rong Zeng,Ke-Zhi Li 한국탄소학회 2005 Carbon Letters Vol.6 No.2

Anti-oxidation coatings are the key technique for carbon/carbon (C/C) composites used as the thermal structural materials. The microstructure and oxidation behavior of several kinds of high-performance ceramic coatings for C/C composites prepared in Northwestern Polytechnical University were introduced in this paper. It showed that the ceramic coatings such as SiC, Si-MoSi2, SiC-MoSi2, Al2O3-mullite-SiC and SiC/yttrium silicate/glass coatings possessed excellent oxidation resistance at high temperatures, and some of these coatings were characterized with excellent thermal shock resistance. The SiC-MoSi2 coating system has the best oxidation protective property, which can effectively protect C/C composites from oxidation up to 1973 K. In addition, the protection and failure reasons of some coatings at high temperature were also provided.

Numeral analysis model for shielding failure of transmission line under lightning stroke

He, Jinliang,Tu, Youping,Zeng, Rong,Lee, J.B.,Chang, S.H.,Guan, Zhicheng IEEE 2005 IEEE transactions on power delivery Vol.20 No.2

The shielding failure is the occurrence of a lightning stroke that bypasses the overhead ground wires and terminates on the phase conductors. The correct design to improve the shielding effect of transmission line to lightning is one of the key problems of transmission line design. A numerical analysis model for shielding failure of transmission line based on electromagnetic field theory is proposed in this paper. The electrical field of the system including lightning leader, transmission line and ground is solved, the range of lightning current striking the phase conductor is obtained, and the shielding failure probability of transmission line is calculated. The lightning leader model and the critical breakdown electrical field intensity of long gap are discussed. The analyzed results by numerical analysis model are compared with those by the electrogeometric model.

Effective length of counterpoise wire under lightning current

He, Jinliang,Gao, Yanqing,Zeng, Rong,Zou, Jun,Liang, Xidong,Zhang, Bo,Lee, Jaebok,Chang, S. IEEE 2005 IEEE transactions on power delivery Vol.20 No.2

In a high soil resistivity area, counterpoise wires are applied to decrease the grounding resistance of tower grounding devices. If the conductor of counterpoise wire is very long, although the power frequency grounding resistance of the tower grounding device is decreased, the lightning protection performance of the transmission line is still not good. The influences of the length of grounding electrodes on the lightning transient characteristic were analyzed. The dynamic and nonlinear effect of soil ionization around the grounding electrode was considered in the analysis model of transient characteristics for the grounding electrodes under lightning impulse. The counterpoise wire has an effective length when lightning passes through it. When the length of a grounding electrode exceeds the effective length, the grounding conductor will not be utilized effectively. The simulating experiments were performed to analyze influences of the length of the counterpoise wire on the impulse characteristics. The formulae to calculate the impulse effective lengths of counterpoise wires were proposed. The model proposed in the paper has been validated by comparing the numerical results with experimental tests.

The Effect of Herb-Partition Moxibustion on Toll-like Receptor 4 in Rabbit Aorta during Atherosclerosis

Zeng-Hui Yue,Xin-Qun He,Xiao-Rong Chang,Jian-Ling Yuan,Bao-Sheng Yu,Mi Liu,Ling Fu,Liang Zhang,Li-Chao Shang 사단법인약침학회 2012 Journal of Acupuncture & Meridian Studies Vol.5 No.2

Objective: To explore the mechanism of Toll-like receptor (TLR4) inhibition in the delay of formation of atherosclerosis by herb-partition moxibustion. Method: Seventy-five rabbits were randomly assigned to one of five groups: blank, atherosclerosis (AS) model, direct moxibustion, herb-partition moxibustion, and drug treatment. With the exception of the blank group, all rabbits were given a high-fat diet in addition to immunologic injury to create the AS model. The experiments were carried out for 16 weeks, at which time the aorta was removed from each rabbit. Immunohistochemical methods were used to detect the gray level of the aortic TLR4 to observe the immunologic competence of its antigens. Fluorescent quantitative polymerase chain reaction was used to detect the expression of TLR4 messenger RNA (mRNA) in the aorta. Results: The gray-scale value of TLR4 and the TLR4 mRNA expression significantly decreased (p < 0.05) in the direct moxibustion, herb-partition moxibustion, and drug treatment groups. Furthermore, the effects of the herb-partition moxibustion and drug treatment were superior to those of the direct moxibustion. Conclusion: Herb-partition moxibustion inhibits aortic TLR4 activity and mRNA expression,showing that herb-partition moxibustion delays the formation of atherosclerosis through the inhibition of TLR4 expression.

Complement Receptor 1 Expression in Peripheral Blood Mononuclear Cells and the Association with Clinicopathological Features And Prognosis of Nasopharyngeal Carcinoma

He, Jian-Rong,Xi, Jing,Ren, Ze-Fang,Qin, Han,Zhang, Ying,Zeng, Yi-Xin,Mo, Hao-Yuan,Jia, Wei-Hua Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Purpose: Complement receptor 1 (CR1) is induced by Epstein-Barr virus (EBV) and may be a potential biomarker of nasopharyngeal carcinoma (NPC). We conducted the present study to evaluate the association of CR1 expression with clinicopathological features and prognosis of NPC. Methods: We enrolled 145 NPC patients and 110 controls. Expression levels of CR1 in peripheral blood mononuclear cells (PBMCs) were detected using quantitative real-time PCR and associations with clinicopathological features and prognosis were examined. Results: CR1 levels in the NPC group [3.54 (3.34, 3.79)] were slightly higher than those in the controls [3.33 (3.20, 3.47)] (P<0.001). Increased CR1 expression was associated with histology classification (type III vs. type II, P=0.002), advanced clinical stage (P=0.003), high T stage (P=0.017), and poor overall survival (HR, 4.89; 95% CI, 1.23-19.42; P=0.024). However, there were no statistically significant differences in CR1 expression among N or M stages. Conclusion: These findings indicate that CR1 expression in PBMCs may be a new biomarker for prognosis of NPC and a potential therapeutic target.

Clinicopathological Features and Prognosis of Gastroenteropancreatic Neuroendocrine Tumors: Analysis from a Single-institution

Zeng, Yu-Jie,Liu, Lu,Wu, Heng,Lai, Wei,Cao, Jie-Zhi,Xu, He-Yang,Wang, Jie,Chu, Zhong-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Background: The gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine neoplasm. We summarized data in our centre to investigate the clinicopathological features, diagnostic methods, therapeutic approaches and prognosis for this neoplasm to increase knowledge of this disease in Asian populations. Method: A total of 122 patients treated at Sun Yet-san Memorial Hospital of Sun Yat-sen University between January 2000 and December 2011 were analyzed retrospectively. Results: Pancreas was the most common site of involvement (65/122, 53.3%); this disease has no special symptoms; positive rates of chromogranin A (CgA) and synaptophysin (Syn) were 81.1% and 87.7%, respectively. The positive rate of Syn had statistical difference among the three grades, but not CgA. Some 68 patients had G1 tumors, 32 G2 tumors and 22 G3 tumors, and Chi-square test showed that higher grading was correlated with worse prognosis (${\chi}^2=32.825$, P=0.0001). A total of 32 patients presented with distant metastasis, and 8 cases emerged during following up. Cox proportional hazards regression modeling showed that the tumor grade (P=0.01), lymphatic metastasis (P=0.025) and distant metastasis (P=0.031) were predictors of unfavorable prognosis. The overall 5-year survival rate was 39.6%, the 5-year survival rate of G1 was 55.7%, and the G2 and G3 were 34.2% and 0%, respectively. Conclusions: The incidence of gastroenteropancreatic neuroendocrine tumors has risen over the last 12 years. All grades of these diseases metastasize readily, and further research regarding the treatment of patients after radical surgery is needed to prolong disease-free survival.

Waste glass powder and its effect on the fresh and mechanical properties of concrete: A state of the art review

He, Zhi-hai,Yang, Ying,Zeng, Hao,Chang, Jing-yu,Shi, Jin-yan,Liu, Bao-ju Techno-Press 2020 Advances in concrete construction Vol.10 No.5

Waste glass is a global solid waste with huge reserves. The discarded waste glass has caused a series of problems such as resource waste and environmental pollution, so it is urgent to recycle waste glass with high replacement level. Glass powder (GP), as a supplementary cementitious material (SCM), used in cement-based materials has already become one of the important ways to recycle waste glass mainly attributed to its pozzolanic reaction and filling effect, especially to the suppressed ASR expansion. This paper demonstrates an overview of the properties of GP and its effect on the fresh and mechanical properties of cement-based materials. The study found that the influence of GP on the performance of cement-based materials mainly depends on its content, particle size, color and type, curing conditions, and other SCMs. Finally, based on the problems involved in the investigation of concrete containing GP, some corresponding suggestions and efforts are given to further guide the utilization of GP in cement-based materials.

Biomass of Bacterioplankton and Protists and Their Ecological Importance in the Bering Sea

He, Jianfeng,Chen, Bo,Kang, Sung-Ho,Zeng, Yinxin,Cai, Minghong Korea Institute of Ocean ScienceTechnology 2004 Ocean and Polar Research Vol.26 No.2

The abundance, biomass and distribution of phytoplankton, bacterioplankton and heterotrophic protists in the Bering Sea were investigated from July to August 1999. Chlorophyll a concentrations in the surface waters ranged from 0.16 to $3.79{\mu}g\;l^{-1}$ Nano-phytoplankton were found to constitute from 63 to 98% of the total phytoplankton biomass, and were clearly the dominant primary producers. The biomass of bacterioplankton in the surface layers varied from 1.46 to $20.2{\mu}g\;C\;l^{-1}$ and accounted for 30% of the total phytoplankton biomass. The biomass of bacterioplankton integrated over a depth of 0 to 100m averaged 65.4% of the total phytoplankton biomass. The surface biomass of heterotrophic protists ranged from 1.2 to $27.4{\mu}g\;C\;l^{-1}$, and was within the same order of magnitude as that of bacterioplankton. Of the total biomass of heterotrophic protists in the upper 100m of the water column, 65% was attributed to protists in the nano-size class. The results of this study suggest that bacteria and nano-protists are important components of the planktonic community in the Bering Sea during the summer season. The abundance of bacterioplankton and planktonic protists decreased from the western to northeastern and eastern regions of the Bering Sea. The abundance of these organisms also decreased with depth. The available evidence suggests that variation in the abundance and distribution of these organisms may be affected by water currents and vertical temperature variation in the Bering Sea.