http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Resistance Reduction Scheme for Tower Grounding with Conductive Cement
Lun Li,Tian Xu,Pei Feng,Liu Xin,Jia Lulu,Deng Chenxing,Wang Xing,Lan Fen,Cheng Hongbo 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3
The construction conditions of transmission lines are becoming more and more diffi cult. It is necessary to fi nd new ways to reduce the grounding resistance of poles and towers at high soil resistivity and small construction area. Conductive cement samples with graphite, stainless steel fi bers, and their mixtures as conductive phases materials were prepared, the resistivity, fl exural strength and compressive strength were tested, compared and analyzed. The graphite and stainless steel fi ber conductive cement with better comprehensive performance was selected out for tower grounding. The application schemes of conductive cement for tower grounding were designed and compared, the partial wrapping scheme was selected and its application methods under diff erent soil resistivity was analyzed. The analysis results can provide theoretical basis and guidance for the application of conductive cement in transmission tower grounding, the feasibility of scheme is proved by the fi eld application.
Sheng-jie Xu,Lun Wu,Qi Zhi Liu,Jun Liu,He Wang,Jie-wen Wang,Ting Zhang 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2
The feeding preference of pear psylla (Cacopsylla chinensis) varies among pear cultivars. To clarify whether leaf structural factors are related to C. chinensis resistance, eleven pear cultivars of three pear species and their hybrids in China were studied. The population size of C. chinensis in plots of different cultivars was investigated, and leaf paraffin sections of each pear cultivar were observed. Correlation analysis results showed that the thickness of palisade tissue (PT) and the thickness ratio (TR) of PT to leaf (L) were the main factors influencing resistance to C. chinensis. The leaves of cultivar Wujiuxiang and those species from France and the USA exhibited the thickest PT and the highest TR; these three cultivars demonstrated much higher resistance to C. chinensis than did the other cultivars. The cultivar Gold Nijisseiki, with a large C. chinensis population size, showed low PT and TR. The findings of this study may provide valuable information to pear growers, experts and scientists regarding plant protection, cultivation and breeding when selecting suitable varieties to culture from the perspective of pest control.
Recent progresses in marine microbial-derived antiviral natural products
Yun‑Fei Teng,Li Xu,Mei‑Yan Wei,Chang‑Yun Wang,Yu‑Cheng Gu,Chang‑Lun Shao 대한약학회 2020 Archives of Pharmacal Research Vol.43 No.12
Viruses have always been a class of pathogenicmicroorganisms that threaten the health and safety of humanlife worldwide. However, for a long time, the treatment ofviral infections has been slow to develop, and only a fewantiviral drugs have been using clinically. Compared withthese from terrestrial environments, marine-derived microorganismscan produce active substances with more novelstructures and unique functions. From 2015 to 2019, 89antiviral compounds of 8 structural classes have been isolatedfrom marine microorganisms, of which 35 exhibit anti-H1N1 activity. This review surveys systematically marinemicrobial-derived natural products with antiviral activityand illustrates the impact of these compounds on antiviraldrug discovery research.
Kang Cai,Xiao Li,Lun-hai Zhi,Xu-liang Han 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.3
The time-varying mean (TVM) component of non-stationary wind speeds is commonly extracted utilizing empirical mode decomposition (EMD) in practice, whereas the accuracy of the extracted TVM is difficult to be quantified. To deal with this problem, this paper proposes an approach to identify and extract the optimal TVM from several TVM results obtained by the EMD. It is suggested that the optimal TVM of a 10-min time history of wind speeds should meet both the following conditions: (1) the probability density function (PDF) of fluctuating wind component agrees well with the modified Gaussian function (MGF). At this stage, a coefficient p is newly defined as an evaluation index to quantify the correlation between PDF and MGF. The smaller the p is, the better the derived TVM is; (2) the number of local maxima of obtained optimal TVM within a 10-min time interval is less than 6. The proposed approach is validated by a numerical example, and it is also adopted to extract the optimal TVM from the field measurement records of wind speeds collected during a sandstorm event.
AC MOKE Measurements of Yttrium Iron Garnet Thin Films
Ming Yau Chern,Wei Lun Xu,Kung Yang 한국자기학회 2018 Journal of Magnetics Vol.23 No.3
The traditional magneto-optical Kerr effect (MOKE) measurements involve measuring the intensity of a light reflected off the samples subjected to a DC magnetic field. By superimposing an AC field to the sweeping DC field, and measuring the AC component of the light intensity, we achieved a high signal-to-noise ratio and a better resolution in determining the Curie temperatures of magnetic samples. For a demonstration, we have determined the Curie temperature of a 350 nm thick YIG (yttrium iron garnet, Y₃Fe5O12) thin film to be 511.0 +/− 0.5 K using this method.
Foamy oil properties and horizontal well inflow performance relationship under solution gas drive
Congge He,Zifei Fan,Anzhu Xu,Lun Zhao 한국자원공학회 2019 Geosystem engineering Vol.22 No.3
In this study, we modified the foamy oil fluid property model by defining the coalescence rate constant to account for the fraction of entrained gas in the oil phase. The modified model was verified by matching the calculated results with experimental data. Then, the horizontal well inflow performance of foamy heavy oil reservoirs was calculated by incorporating the modified fluid properties into the horizontal well flow rate equation at pseudo-steady state. In addition, the horizontal well inflow performance of foamy oil under solution gas drive and the corresponding conventional oil was compared. The results show that the foamy oil fluid properties calculated by the modified fluid property model are consistent with the experimental results, thus verifying the correctness of the model. Comparing the horizontal well inflow performance of foamy oil and conventional oil, it shows that when the average reservoir pressure is between bubble point pressure and pseudo-bubble point pressure, the flow rate of foamy oil is higher than that of the conventional oil. When the average reservoir pressure drops below the pseudo-bubble point pressure, the flow rate of foamy oil is close to that of the conventional oil. Foamy efficiency, defined as the ratio of the difference between the flow rate of foamy oil and conventional oil to the conventional oil flow rate, has the biggest value, about 15%, close to the pseudo-bubble point.
Dryland agricultural environment and sustainable productivity
Gou-Xia Li,Bing-Cheng Xu,Li-Na Yin,Shi-Wen Wang,Sui-Qi Zhang,Lun Shan,곽상수,Qingbo Ke,Xi-Ping Deng 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.2
Global climate change is expected to cause progressively increased frequency and severity of drought events, which further seriously limit plant growth and crop yields. Increasing water use effi ciency (WUE) and yield per unit rainfall are one of the most important challenges in dry land agriculture. Here, we reviewed the comprehensive technical strategies including conserving water to combine both increased agricultural productivity and resource conservation; enquiring into how crop plants respond to drought through morphological, physiological, and molecular modifi cations that occur in all plant organs; breeding for drought tolerance where there is a delineated stress environment and genotype × environment interactions are stable; eff ective conservation of rainfall and high effi ciency of use. In addition, we discussed the preponderance of biological water-saving measures, which embraces improvements in WUE and drought tolerance, by genetic improvement and physiological regulation. Sustainable agriculture would be benefi ted from modern engineering such as biological engineering, conservation tillage, and breeding technologies.