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多端柔性直流系统在分布式能源和直流负荷接入、网络柔性互联、电能质量等方面具有显著优势，成为未来电网的重要发展趋势。为了保证多端柔性直流系统安全稳定可靠运行，需要能够在数毫秒内开断故障电流的直流断路器。本文面向张北±500 kV柔性直流电网示范工程的应用需求，开展了500 kV直流断路器原理研究与样机研制。首先，提出500 kV耦合负压换流型混合式直流断路器系统方案，给出其拓扑结构、工作原理和控制逻辑；进而，设计基于电磁斥力操动机构和电磁缓冲机构的快速机械开关、基于二极管和复合被动保护支路的交叉桥式电力电子开关和基于耦合负压电路的换流装置等；最后，研制500 kV耦合负压换流型混合式直流断路器工程样机进行实验验证。研究结果表明，研制的100 kV混合式直流断路器能够在3 ms开断25 kA短路电流，具有低损耗、低成本、高可靠性等特点，相关成果已经过实验验证。

Copyright of Guangdong Agricultural Sciences is the property of South China Agricultural University, Guangdong Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guangdong Agricultural Sciences is the property of South China Agricultural University, Guangdong Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guangdong Agricultural Sciences is the property of South China Agricultural University, Guangdong Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Synthetic Crystals is the property of Journal of Synthetic Crystals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guangdong Agricultural Sciences is the property of South China Agricultural University, Guangdong Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates the impact of pruning on tree growth and the timber type structure of a 17-year-old middle-aged Chinese fir plantation, with a focus on cultivating knot-free Chinese fir logs. We established pruning and non-pruning treatments and observed their effects after 20 years. The results indicate that pruning significantly increased the annual growth of diameter at breast height(DBH) during the first two years(P<0.05). However, it did not have a significant impact on annual tree height growth or stand volume. Over time, the effect of pruning on the growth of the Chinese fir plantation gradually diminished, with no significant impact on DBH, tree height, or stand volume after 20 years. Additionally, pruning did not significantly affect the total biomass of the plantation after two decades but did increase the proportion of trunk biomass allocation(P<0.05) while decreasing the proportion of leaf biomass allocation(P<0.05). Furthermore, pruning significantly enhanced the yield of large-diameter timber after 20 years(P<0.05), which proved beneficial for cultivating knot-free logs from the Chinese fir plantation. [ABSTRACT FROM AUTHOR]

Copyright of Science Technology & Engineering is the property of Chinese Society of Technology Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective]To identify the sudden death causes of Mauremys mutica in a breeding farm in Shenzhen, Guangdong Province.[Method]A dominant strain named GZWO1 was isolated from the liver, spleen and other focal tissues of the infected Mauremys mutica by the scribing plate separation method. The morphological characteristics, physiological and biochemical characteristics of the isolated strain were identified, and the general primers were used: 16SrDNA sequence was amplified by 27F and 1492R, and the classification status of the pathogen was analyzed by using DNAMAN and MEGA-6.0 software. The pathogenicity of the pathogen was verified by animal regression infection test, and effective treatment and prevention methods were screened by drug sensitivity test.[Result]Strain GZW01 was a rod-like gram-negative bacterium. Its enzyme activity, gluconate test, mannitol, mannose, sucrose, arabinose, inositol, Tanose, MR, VP, arginine decarboxylase and other physiological and biochemical tests were positive, which could produce glucose gas. It had 99% homology with Aeromonas veronii on NCBI. The regression infection test showed that strain GZW01 was highly pathogenic to Tenebrio flavus. The results of drug sensitivity showed that the isolated strain was resistant to penicillin G, benzoxicillin sodium, ampicillin, tetracycline, vancomycin, clindamycin, and a total of six drugs. It was moderately sensitive to clarithromycin; and highly sensitive to 28 antibiotics such as gentamicin, erythromycin, ofloxacin and amtrannan.[Conclusion]Aeromonas veronii was the pathogenic bacterium that caused sudden death of the Mauremys mutica in a breeding farm in Shenzhen City. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Preventive Veterinary Medicine / Zhongguo Yufang Shouyi Xuebao is the property of Chinese Journal of Preventive Veterinary Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Feed Research is the property of Editorial Board of Feed Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To investigate the expression of kinesin family member 23 (KIF23) in colorectal cancer, as well as its biological function and possible mechanism in colorectal cancer cells. Methods The cancer tissues and adjacent normal tissues from 20 colorectal cancer patients diagnosed and treated in Guangxi Medical University Cancer Hospital, from May 2021 to December 2021 were collected. The expression of KIF23 in colorectal cancer tissues was detected by RT⁃qPCR, its relationship with clinicopathological characteristics was analyzed, and the expression differences were verified by using an online database (TGGA，CCLE). KIF23 in human colorectal cancer RKO cells was silenced by using the siRNA transfection technology, cell proliferation and migration ability were detected by the CCK⁃8 assay, EDU proliferation assay, and Transwell migration assay. The expression levels of MDM2, p53, and p21 were detected by Western blot. Results The expression of KIF23 in colorectal cancer tissues was higher than that in adjacent normal tissues (P<0.0001), and the online database validation results showed the same trend (P<0.0001). Univariable analysis showed that expression level of KIF23 was correlated with tumor metastasis, CEA and CA199 levels (all P<0.05). The results of the vitro experiments showed that, compared with the siNC group, the proliferation and migration ability was significantly decreased in the siKIF23 group (all P<0.01), the protein expression levels of KIF23 and MDM2 were decreased (all P<0.01), and the protein expression levels of p53 and p21 were increased (all P<0.01). Conclusions KIF23 is highly expressed in colorectal cancer tissues, and may regulate malignant behaviors such as proliferation and migration of colorectal cancer cells through the MDM2⁃p53/p21 signaling pathway. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Wildlife / Yesheng Dongwu Xuebao is the property of Chinese Journal of Wildlife Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Water Conservancy Science & Techonlogy & Economy is the property of Water Conservancy Science & Technology & Economy Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Forest Engineering is the property of Forest Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Preventive Veterinary Medicine / Zhongguo Yufang Shouyi Xuebao is the property of Chinese Journal of Preventive Veterinary Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of New Architecture is the property of New Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Architectural Journal / Jian Zhu Xue Bao is the property of Architectural Journal Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Practical Oncology Journal is the property of Journal of Practical Oncology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Preventive Veterinary Medicine / Zhongguo Yufang Shouyi Xuebao is the property of Chinese Journal of Preventive Veterinary Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Southwest China Journal of Agricultural Sciences is the property of Editorial Department of Southwest China Journal of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Ritual, Theatre & Folklore / Mínsú Qǔyì is the property of Shih Ho-Cheng Folk Culture Foundation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper attempts to discuss the relationship between multimarket contact, market entry and firm performance as a starting point to provide suggestions for firms how to adopt rational and effective competitive strategy in the dynamic competitive environment. The proposed hypotheses were verified by regression analysis and robustness test. The results show that: firstly, multimarket contact has an inverted U-shape influence on market entry; secondly, market entry has a shadowing effect on the relationship between multimarket contact and firm performance. That is, the positive direct effect of multimarket contact on firm performance is greater than the negative indirect effect multimarket contact on firm performance through market entry; and then the political background of CEO has a negative moderating influence on the relationship between multimarket contact and market entry. Therefore, based on the above analysis results, this paper argues that the firm takes the initiative to increase the degree of multimarket contact with competitors can be regarded as an important non-market strategy. [ABSTRACT FROM AUTHOR]