http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A Novel Three-Phase Four-Wire Grid-Connected Synchronverter that Mimics Synchronous Generators
Tan, Qian,Lv, Zhipeng,Xu, Bei,Jiang, Wenqian,Ai, Xin,Zhong, Qingchang The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
Voltage and frequency stability issues occur in existing centralized power system due to the high penetration of renewable energy sources, which decrease grid absorptive capacity of them. The grid-connected inverter that mimics synchronous generator characteristics with inertia characteristic is beneficial to electric power system stability. This paper proposed a novel three-phase four-wire grid-connected inverter with an independent neutral line module that mimics synchronous generators. A mathematical model of the synchronous generator and operation principles of the synchronverter are introduced. The main circuit and control parameters design procedures are also provided in detail. A 10 kW prototype is built and tested for further verification. The primary frequency modulation and primary voltage regulation characteristics of the synchronous generator are emulated and automatically adjusted by the proposed circuit, which helps to supports the grid.
A Novel Approach to Cloning and Expression of Human Thymidylate Synthase
Lv, Ying-Tao,Du, Pei-Juan,Wang, Qiao-Yan,Tan, Yuan,Sun, Zong-Bin,Su, Zhong-Liang,Kang, Cong-Min Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12
Thymidylate synthase (TS) catalyzes the transfer of a methyl group from methylenetetrahydrofolate to dUMP to form dTMP. It is a primary target in the chemotherapy of colorectal cancers and some other neoplasms. In order to obtain pure protein for analysis of structure and biological function, an expression vector TS-pET28b (+) was constructed by inserting wild-type human thymidylate synthase (hTS) cDNA into pET28b (+). Then an expression strain was selected after transformation of the recombined plasmid into Rosetta (DE3). Fusion protein with His-tag was efficiently expressed in the form of inclusion bodies after IPTG induction and the content was approximately 40.0% of total bacteria proteins after optimizing expression conditions. When inclusion bodies were washed, dissolved and purified by Ni-NTA under denatured conditions, the purity was up to 90%. On SDS-PAGE and West-blotting, the protein band was found to match well with the predicted relative molecular mass-36kDa. Bioactivity was 0.1 U/mg. The results indicated that high-level expression of wild-type hTS cDNA can be achieved in prokaryotes with our novel method, facilitating research into related chemotherapy.
Weichuan Tan,Shanlin Du,Yunfei He,Guoqiang Lv,Wenhui Ma,Aimin Xing,Jie Huang 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8
The structure of the gas distributor was optimized to enhance the reaction rate of direct synthesis of siliconemonomers in a fluidized bed. In this work, the opening rate range was selected by the critical pressure drop ratio, andthe influences of opening ratio and the holes quantities of distribution plate on the synthesis process were systematicallystudied by numerical simulation approaches. The fluidization velocity was simplified by Reylows’ and Archimedes’ criterionnumbers. To better predict the gas-solid fluidization characteristics in the bed, the drag model was modified by thecritical fluidization velocity. In addition, the distributor performance was investigated from the perspectives of solidphase volume fraction, pressure drop change, bubble behavior and power spectrum analysis, etc. The results show thatthe distribution plate pressure drop ratio is about 0.11679 at the opening rate of 0.53%, which meets the design criterionof reducing the dissipation while increasing the fluidized quality. A high frequency and a low amplitude arise at theopening rate of 0.53%, indicating the corresponding favorable efficiency of heat and mass transfer. The maximum fluctuationrange of the solid phase distribution with =0.53% is only 1.7%, indicating that the inhomogeneity of the solidphase fraction distribution is the lowest, and the fluidization stability is improved by about 30%. Consequently, =0.53%is proposed as the best distributor configuration and enhanced the monomer synthesis efficiency.
Sum-Rate Analysis for 3D MIMO with ZF Receivers in Ricean/Lognormal Fading Channels
( Fangqing Tan ),( Hui Gao ),( Xin Su ),( Tiejun Lv ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.7
In this paper, we investigate the performance evaluation of three dimensional (3D) multiple-input multiple-output (MIMO) systems with an adjustable base station (BS) antenna tilt angle and zero-forcing (ZF) receivers in Ricean/Lognormal fading channels. In particular, we take the lognormal shadow fading, 3D antenna gain with antenna tilt angle and path-loss into account. First, we derive a closed-form lower bound on the sum rate, then we obtain the optimal BS antenna tilt angle based on the derived lower bound, and finally we present linear approximations for the sum rate in high and low-SNR regimes, respectively. Based on our analytical results, we gain valuable insights into the impact of key system parameters, such as the BS antenna tilt angle, the Ricean K-factor and the radius of cell, on the sum rate performance of 3D MIMO with ZF receivers.
A Novel Three-Phase Four-Wire Grid-Connected Synchronverter that Mimics Synchronous Generators
Qian Tan,Zhipeng Lv,Bei Xu,Wenqian Jiang,Xin Ai,Qingchang Zhong 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
Voltage and frequency stability issues occur in existing centralized power system due to the high penetration of renewable energy sources, which decrease grid absorptive capacity of them. The grid-connected inverter that mimics synchronous generator characteristics with inertia characteristic is beneficial to electric power system stability. This paper proposed a novel three-phase four-wire grid-connected inverter with an independent neutral line module that mimics synchronous generators. A mathematical model of the synchronous generator and operation principles of the synchronverter are introduced. The main circuit and control parameters design procedures are also provided in detail. A 10 ㎾ prototype is built and tested for further verification. The primary frequency modulation and primary voltage regulation characteristics of the synchronous generator are emulated and automatically adjusted by the proposed circuit, which helps to supports the grid.
Yan Li,Tan Lv,Fang-Xian Zhao,Xiao-xue Lian,Yun-ling Zou,Qiong Wang 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.3
Loading noble metal and exploring suitable morphology to achieveexcellent gas-sensing performance is very crucial for the fabrication ofgas sensors. We have successfully synthesized Au-loaded ZnO (Au/ZnO) nanospindles (NSs) through a really facile procedure involving aprecipitation and subsequent microwave irradiation. The as-preparedproducts have been characterized by X-ray diffraction (XRD), scanningelectron microscope (SEM). The formation and gas-sensing mechanismof Au/ZnO NSs were discussed. The SEM micrographs revealed aninteresting morphological evolution of the Au/ZnO NSs with Auloadingcontent ranging from 0 at. % to 7 at. %. The nanostructures wereemployed for gas-sensing measurement toward various gases. Itindicated that the Au/ZnO NSs based sensor showed a highly enhancedresponse (226.81) to 400 ppm acetone gas at a relatively low workingtemperature (270°C), and exhibited a fast response (1 s) and recoveryspeed (10 s). The highly enhanced acetone gas sensitivity of Au/ZnONSs based sensor could be attributed to its enhanced polarity owing tothe peculiar morphology, Schottcky barriers, as well as catalytic effect ofAu NPs.
Meng-Meng Lv,Ming-Hui Tan,Li-Wen Lu,Rong-Hua Zhang,Zhi-Yong Guo,Cheng-Xiong Liu,Jin Yang,Kun Zou,Peter Proksch 한국생약학회 2018 Natural Product Sciences Vol.24 No.3
Two new polyketides, chinoketides A and B (1 - 2) with a known compound xylarphthalide A (3), were isolated from the solid medium of the endophytes from the leaves of the relic plant Distylium chinense with the "black-box" co-culture method, and the structures of two new compounds were elucidated by NMR, MS and CD spectra. And the absolute configurations of chinoketides A (1) and B (2) were determined as 2R,3R,8S and 5R,6S by calculating their ECD spectra to compare with the experimental CD spectra. Finally, the antimicrobial activities were evaluated to Erwinia carotovora sub sp. Carotovora (Jones) Bersey et al, and the results showed that compounds 1 - 3 displayed the antimicrobial activities with MIC value at 20.5, 30.4 and 10.2 mg/mL.
Zhang, Yuanyuan,Li, Jun,Lv, Mingyun,Tan, Dongjie,Zhu, Weiyu,Sun, Kangwen The Korean Society for Aeronautical and Space Scie 2016 International Journal of Aeronautical and Space Sc Vol.17 No.3
Solar energy is the ideal power choice for long-endurance stratospheric airships. The output performance of solar array on stratospheric airship is affected by several major factors: flying latitude, flight date, airship's attitude and the temperature of solar cell, but the research on the effect of these factors on output performance is rare. This paper establishes a new simplified analytical model with thermal effects to analyze the output performance of the solar array. This model consisting of the geometric model of stratospheric airship, solar radiation model and incident solar radiation model is developed using MATLAB computer program. Based on this model, the effects of the major factors on the output performance of the solar array are investigated expediently and easily. In the course of the research, the output power of solar array is calculated for five airship's latitudes of $0^{\circ}$, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$, four special dates and different attitudes of five pitch angles and four yaw angles. The effect of these factors on output performance is discussed in detail. The results are helpful for solving the energy problem of the long endurance airship and planning the airline.
Comparison of volatile components in fresh and dried Zanthoxylum bungeanum Maxim
Wenlin Zhang,Si Tan,Wanpeng Xi,Jianlei Yang,Qinhong Liao,Jianbin Lan,Yukui Lv,Jianmin Tang 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.4
Fresh and dried Zanthoxylum bungeanumMaxim volatiles of two main cultivars including Dahongpaoand Meihuajiao, were determined through GC–MS andcompared. In all the tested samples, linalool, D-limonene,eucalyptol, 3-nonanone, and b-myrcene were identified asthe five predominant components. The percentages of thesecomponents in fresh Dahongpao were 23.89%, 21.04%,7.46%, 5.63% and 5.87%, respectively. Similar percentages,27.28%, 17.62%, 6.39%, 1.66% and 7.8%, werefound in dried Dahongpao. In general, the contents oflinalool and b-myrcene in dried Dahongpao and Meihuajiaowere slightly higher than those in fresh samples,whereas the contents of D-limonene, eucalyptol, and3-nonanone were lower. Partial least squares discriminantanalysis results showed that the two cultivars could beclearly differentiated based on volatiles, whereas, the freshand dried Zanthoxylum bungeanum Maxim samples couldnot. This demonstrated that the drying process had nosignificant effect on the volatiles.