Search

为实现更强的能量耗散能力，混合式高压直流断路器的耗能支路需串并联大量金属氧化物压敏电阻（metal oxide varistor，MOV），耗能支路的可靠性将直接影响混合式高压直流断路器的可靠性。但是，现有的耗能支路故障检测方法并不能适应整个能量耗散阶段。为此，提出一种基于经验傅里叶分解的混合式高压直流断路器耗能支路故障检测方法，具体为：首先是信号预处理，对耗能支路每个子模块的分支电流进行归一化和一阶差分计算来获取分析电流；然后是故障特征提取，利用经验傅里叶分解（empirical Fourier decomposition，EFD）对分析电流进行分解，提取最高频时频分量作为故障特征分量；最后是检测判据，通过故障特征分量构造突变峰值量化指标，进而通过突变峰值实现耗能支路故障检测。大量实验表明，该检测方法可在能量耗散阶段末期实现可靠地故障检测，且具备一定的抗干扰能力。

中国“三北”地区可再生能源装机占比普遍超过30%，高比例新能源电力系统形态已经基本形成。传统新能源电站面对高比例新能源接入电网频率/电压的扰动，无法提供有效的主动调频/调压支撑能力，会导致电力系统惯性和阻尼降低，给电网的安全稳定运行提出重大挑战。中国国家电网公司于2016年在张北风光储电站启动建设首个用于大电网的虚拟同步机示范工程，探索虚拟同步机多种实现方式和技术路线的可行性与经济性，已经取得阶段性成果。文中针对风电、光伏单元式虚拟同步机的不同技术路线进行了对比分析，介绍了虚拟同步发电机示范工程的进展情况，阐述了单元式、电站式两种虚拟同步机实现方式的工程实施方案，对已改造设备的运行情况进行了初步分析，对已改造设备的控制效果进行了实测验证。最后，文章对区域电网中虚拟同步机的控制应用方式以及预期效果作了初步分析，对关键技术的发展作了展望。

Copyright of Journal of Xi'an Jiaotong University is the property of Editorial Office of Journal of Xi'an Jiaotong University 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 Traditional Chinese Drug Research & Clinical Pharmacology is the property of Traditional Chinese Drug Research & Clinical Pharmacology 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 Evaluation & Analysis of Drug-Use in Hospitals of China is the property of Evaluation & Analysis of Drug-Use in Hospitals of China Editorial Board 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 Power Generation Technology is the property of Power Generation Technology 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 Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department 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 Xi'an Jiaotong University is the property of Editorial Office of Journal of Xi'an Jiaotong University 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 Smart Agriculture is the property of Smart Agriculture 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 Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) 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 Traditional Chinese Drug Research & Clinical Pharmacology is the property of Traditional Chinese Drug Research & Clinical Pharmacology 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 Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society 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 Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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 Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) 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 Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications 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.)

In this paper, the spindle system of the new disc chipper for forestry residues such as branch wood, tending timber and thinning timber was studied, and the installation structure of the cutter head and spindle of the chipper was different from the current mainstream installation form, and it was necessary to verify whether the spindle system met the structural design requirements in the process of cutting logs. ADAMS software and ANSYS software were used to establish the rigid-flexible coupling model of the flexible spindle, the law of the periodic variation of cutting force was added to the model, and the axial and radial amplitudes of the spindle at the connection point between the spindle and the cutter head were simulated and extracted, and the maximum vibration amplitude of the cutter head in the radial direction was 175μm, which met the long-term operation standard of the rotating shaft stipulated in the Chinese national standard. This study provides a verification of the rationality of the new chipper spindle system, and provides a theoretical basis for the structural improvement of the chipper spindle system. [ABSTRACT FROM AUTHOR]

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical 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 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.)

Copyright of Journal of Functional Materials / Gongneng Cailiao is the property of Chongqing Functional Materials Periodical Press 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.)

Diabetic retinopathy (Diabetic Retinopathy, DR) is the symptom of diabetes affecting the retina during the onset of diabetes. Aiming at the problem of information loss of lesion areas such as microimages during model downsampling, this paper proposes a module of DenseNet fusion residual structure. This module first connects two consecutive Dense block, then sums the feature information using the residual structure, and processes the feature image information in parallel to prevent the loss of effective feature information. Finally, finally, the residual connects the two convolution blocks containing drop out to suppress the overfitting phenomenon. To solve the problem of the channel weighting of the feature graphs of lesion areas in previous convolution operations, the paper proposes a module of SeNet fusion residue structure. This module first connects SeNet, adds the feature information of global average pooling and global maximum pooling to improve the utilization of effective channel information, and then ensures the integrity of feature graph information through the residual mode of conv1x1. Based on the design of the above two modules, the paper proposes a DR classification method of DenseNet and SeNet fusion residue structures. The model achieves 89.8%precision and 97.0% specificity on the APTOS2019 dataset, 78.8% accuracy and 91.9% specificity on the Messidor-2dataset, which can effectively improve the classification ability of the degree of retinal lesions. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis 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 South China University of Technology (Natural Science Edition) is the property of South China University of Technology 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 Food & Machinery is the property of Food & Machinery 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.)

OBJECTIVE: To evaluate the clinical practice guidelines for antiplatelet therapy in patients with acute coronary syndrome (ACS) published domestically and internationally from 2010 to 2019 according to appraisal of guidelines for research and evaluation Ⅱ (AGREE Ⅱ) tool. METHODS: Guidelines and related literature for the treatment of antiplatelet drugs in patients with ACS published domestically and internationally from 2010 to 2019 were selected as the research object, and AGREE Ⅱ was used to perform systematic review, and the differences between recommended contents of the guidelines were analyzed. RESULTS: A total of 10 relevant guidelines were included, including 7 treatment guidelines and 3 expert recommendations and consensus. Mean scores for each domain of AGREE Ⅱ were (82. 5±8. 7)% for scope and purpose, (67. 5±15. 3)% for participants, (68. 7±18. 2)% for rigor of formulation, ( 89. 3 ± 4. 0)% for clarity of presentation, ( 68. 1 ± 13. 8)% for applicability, ( 54. 8 ± 12. 3)% for editorial independence, and (65. 7±12. 3)% for overall evaluation. The intra-group correlation coefficient and 95%CI was 0. 89 ( 0. 72-0. 92), indicating a high degree of consistency in researcher scores. All guidelines recommend aspirin + P2Y12 receptor antagonist combined with antiplatelet therapy after surgery. CONCLUSIONS: Clinical guidelines recommend aspirin + P2Y12 receptor antagonist combined with antiplatelet therapy for 12 months. Genetic testing is not necessary in patients with ACS. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society 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 Atomic & Molecular Physics (1000-0364) is the property of Journal of Atomic & Molecular Physics 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 Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan 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 Tobacco Science & Technology is the property of Tobacco Science & Technology 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 Computational Mechanics / Jisuan Lixue Xuebao is the property of Chinese Journal of Computational Mechanics Editorial Office, Dalian University of Technology 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 Evaluation & Analysis of Drug-Use in Hospitals of China is the property of Evaluation & Analysis of Drug-Use in Hospitals of China Editorial Board 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 Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board 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 Frontiers of Computer Science & Technology is the property of Beijing Journal of Computer Engineering & Applications Journal Co Ltd. 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.)

A strain HS5B5 producing indole-3-acetic acid was identified by morphological observation, physiological and biochemical tests and 16S rDNA sequence analysis. The medium composition and fermentation conditions of strain HS5B5 were optimized by single factor and orthogonal test. The results showed that the strain HS5B5 was Bacillus subtilis. The optimized medium composition and fermentation conditions were mannitol 5.0 g/L, beef extract 7.5 g/L, calcium chloride 2 mmol/L, inoculum 6%, pH value 7.3, temperature 28 ℃ and liquid content 30 mL, respectively. The content of indole-3-acetic acid in the fermentation broth of strain HS5B5 after optimization was (108.90±1.10) mg/L, which was 183.08% higher than that before optimization. The research results enrich the resources of microbial strains and provide technical support for large-scale production. [ABSTRACT FROM AUTHOR]

Copyright of Acta Sedimentologica Sinica is the property of Acta Sedimentologica Sinica 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 Special Oil & Gas Reservoirs is the property of Special Oil & Gas Reservoirs 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 Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING 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.)

With the launch of a unified national carbon market in China, its synergistic effects on promoting carbon emission reduction in the power industry with renewable energy subsidies are noteworthy. The traditional view is that the total amount of carbon emissions is fixed under the carbon trading policy and the renewable energy subsidy policy under the total amount control will no longer play an additional role in reducing emissions, and would even lead to excessive carbon market quotas, distorting carbon market prices. This paper establishes a general equilibrium analysis framework for national carbon trading and examines the parallel emission reduction effects of renewable energy subsidies in the power industry and the national carbon market and their policy synergy paths. The results show that: ① The national carbon market and renewable energy subsidy policy for the power industry would both bring about CO2 emission reduction in the whole industry. ② The carbon market that only covers the power industry would produce a ‘carbon leakage’ effect, which would lead to an increase in carbon emissions in non-power industries. On this basis, continuing the renewable energy subsidies may alleviate the ‘carbon leakage’ by means of the transfer of production factors among industries or lead to excessive carbon market quotas by ‘greening’ the power production structure. ③ Considering two sources of renewable energy subsidies: the one-time tax on residents (resident income tax) and the renewable energy electricity price surcharge (electricity consumption tax), the emission reduction effect of the former resource is better than that of the latter resource, and the latter may even cause ‘cross-border damage.’ ④ The renewable energy subsidies would lead to a decrease in the carbon market transaction price. The FIT is better than the FIP, and it is necessary to increase the total amount of constraints to effectively restrain the decline of carbon trade prices. As the carbon market expands and improves, renewable energy subsidies can be gradually reduced or even eliminated to avoid their impact on the carbon market price. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power is the property of Electric Power 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 Clinical Nursing in Practice is the property of Journal of Clinical Nursing in Practice (Editorial Board, Shanghai Jiao Tong University Press) 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.)

BACKGROUND: Although prefabricated flap is an ideal method to repair composite defects, the risk of flap necrosis is still an urgent problem to be solved. Therefore, promoting the revascularization of prefabricated flap can improve its survival rate and reduce complications. OBJECTIVE: To investigate the effect of expanded polytetrafluoroethylene membrane barrier material on vascular regeneration of prefabricated flap in rats. METHODS: Thirty SD rats were randomly divided into three groups with 10 rats in each group: control group, silica gel membrane group and expanded polytetrafluoroethylene group. In the silica gel membrane group and expanded polytetrafluoroethylene group, bilateral back arbitrary flaps (7.5 cm long and 1.5 cm wide) were prefabricated by the barrier delay method. Silica gel membrane and expanded polytetrafluoroethylene membrane were implanted under the flap. In the control group, the flap was prefabricated with non-barrier delay method, and the flap was directly sutured in situ without barrier under the flap. The vascular regeneration was observed after operation. At 14 days after operation, the flap tissue was stained with hematoxylin and eosin. Immunohistochemistry for vascular endothelial growth factor and CD34 was utilized to detect the activity of superoxide dismutase and the level of malondialdehyde. RESULTS AND CONCLUSION: (1) At 2 weeks after operation, the flap was cut again. In the silica gel membrane group, some rats had axial vascular regeneration and one rat had silicone curl. All rats in the expanded polytetrafluoroethylene group had obvious axial vessels. (2) The microvessel density of expanded polytetrafluoroethylene group was significantly higher than that of control group and silica gel membrane group (P < 0.05). The number of CD34 positive vessels in expanded polytetrafluoroethylene group was significantly higher than that in the control and silica gel membrane groups (P < 0.05). The integral absorbance of vascular endothelial growth factor protein in the expanded polytetrafluoroethylene group was significantly higher than that in the control and silica gel membrane groups (P < 0.05). (3) The activity of superoxide dismutase in the expanded polytetrafluoroethylene group was higher than that in the silica gel membrane group and control group (P < 0.05), and the level of malondialdehyde was lower than that in silica gel membrane group and control group (P < 0.05). (4) Using expanded polytetrafluoroethylene membrane as barrier delay material can promote the angiogenesis of prefabricated flap in rats, reduce oxidative stress, and improve the survival rate of the flap. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering 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.)