Search

This study presents an improved double closed-loop current (fundamental and harmonics current) control method for inductive-capacitive-inductive (LCL) type shunt active power filter (SAPF), which is designed to enhance the robustness of the SAPF system to adapt weak grid application condition. Due to the variation of weak grid impedance, fundamental current control loop based on grid current feedback control method may become unstable, a robust parameters design method in discrete z-domain according to amplitude-frequency and phase-frequency characteristics is proposed to fit the grid impedance variation. The harmonics current of non-linear load exists in a wide frequency range, normal resonant controller will cause the system unstable due to the negative −180° cross of phase at high-frequency range, a digital phase-lead resonant controller (PL-RC) is proposed to extend the bandwidth of the harmonics current control, then the quantities of the PL-RCs used to suppress harmonics can be increased considerably compared with normal resonant controller. Experimental results are presented to verify the effectiveness of the robust parameters design method and the proposed PL-RC.

Senecavirus A (SVA), also known as Seneca Valley virus (SVV), is an emerging infectious pathogen which have been detected in swine herds from the Brazil, USA, Colombia, Thailand, Canada and some provinces in China, suggesting an increasing geographic distribution of this novel virus. Here, we isolated and characterized a SVV, designated SVA CH-GX-01-2018, thought to be responsible for typical vesicular lesions on the snouts and hooves of finishing pigs from a swine herds in Guangxi province, China, in August 2018. Phylogenetic analysis and sequence alignment indicated that this SVA CH-GX-01-2018 strain was closely related to the strains isolated in 2017 in Guangdong province, a neighboring province of Guangxi, South China, with 98.6% identity at the genome nucleotide level. Our findings characterized a novel SVV infection in pigs from South China and emphasize the importance of surveillance, reinforcing biosecurity measures and developing vaccines to prevent the spread of this viral pathogen.

Background Porcine respiratory and reproductive syndrome virus (PRRSV) is one of the most economically significant pathogens in the Chinese swine industry. ORF5 and nsp2 are highly variable regions of the PRRSV genome. Therefore, nsp2 and GP5 are often selected for investigation of variations and phylogenetic analyses for their genetic diversities. Knowledge of the molecular evolution of PRRSV field strains may contribute to the control of PRRS in China. Results The results of multiple sequence alignments of GP5 showed that there is 84.5–100% aa identity among the 56 strains in this study. These strains shared 84.5–99.0% aa identity with the prototypical type 2 PRRSV VR-2332 and 56.6–59.2% with strain LV, prototypical type 1 PRRSV. Phylogenetic analysis showed there is considerable diversity among PRRSV ORF5 and the existence of two lineages (5 and 8). Most of the strains were classified into lineage 8 with multiple sub-lineages (3, 4 and 6). Moreover, PRRSV strains with 5 novel patterns of deletions or insertions in the nsp2 region were found. Conclusions Phylogenetic analysis based on ORF5 sequences indicated the diversity of PRRSV in southern parts of China and the strains with 30 aa deletion in nsp2 are dominant in the porcine population. Also, new PRRSV strains with different patterns of deletions or insertions in nsp2 are emerging. The data presented here constitute a useful basis for further epidemiological studies regarding the heterogeneity of PRRSV strains in China and provide a basis for the prevention of PRRS in southern parts of China. Electronic supplementary material The online version of this article (10.1186/s12917-019-1906-9) contains supplementary material, which is available to authorized users.

Table S1. Comparison of the GP5 sequences of the different PRRSV strains examined in this study. (DOCX 14â kb)

Phylogenetic tree based on PCV2 ORF2 sequences. Phylogenetic tree based on a comparison of 129 PCV2 ORF2 sequences, including the 95 sequences from this study and 34 PCV2 sequences originating from China and other countries. The tree was constructed using the Maximum Likelihood algorithm. The 34 reference strains which are representatives of all PCV2 genotypes are marked with a black circle. (PPTX 203 kb)

Table S2. The positions and sizes of aa insertions and deletions in nsp2 of PRRSV strains compared to VR2332. (DOCX 26â kb)

“中国价值观” 是相对于 “美国价值观” , “亚洲价值观” , “华盛顿共识” 等 而言的, 是中国社会价值体系长期发展演变的结果, 是当代中国价值复杂性的观念表 现和理论提升。在历史与时代, 中国与世界的多维背景中分析中国当前复杂价值状况 的历史生成, 演进逻辑, 多元构架, 深层原因与内在依据,透视西方几百年现代化进 程中的历时性矛盾在当代中国的共时性并存, 我们主张以复杂性的思维与方法来看待 当前中国的复杂价值现实和价值观念, 在多重线索汇聚和多元变化整合的动态过程中 积极守护 “中国利益” , 合理履行 “中国责任” , 自觉探寻 “中国道路” , 清醒回应 “中国期盼” , 自觉化解 “中国难题” , 恰当彰显 “中国信心” , 更好地发挥出哲学 社会科学在解读与引领社会发展的积极功能。 关键词: 中国价值观 多元价值 核心价值 复杂性思维 “Chinese values” is a concept defined in relation to “American values,” “Asian values” and the “Washington Consensus.” It is a product of the long-term development and evol ut ion of Chi nese soci et y’s val ue syst em and const it ute s the c onc ept ua l representation and theoretical enhancement of the complexity of current Chinese values. We analyze the historical formation, evolutionary logic, pluralistic framework, underlying reasons, and inner grounds of present day China’s complex values in a multi- dimensional context that involves history and the present as well as China and the world, looking at the synchronous coexiste...

Globalization was just emerging but did not really take shape during Karl Marx’s time. In fact, both Karl Marx and Engels predicted the trend of globalization but did not really live in such a time. Therefore, globalization is still a new issue and a new research area for Marxist philosophy today. Based on the distinctions between some important concepts such as globalization and modernization, this paper probes the problems concerning the development of modernity theory, social morphology and civilization theory, and the Marxist theory of values raised in the process of globalization. The paper also explores some theoretical issues concerning the socialist modernization with Chinese characteristics in the Marxist philosophy, and contemplates possible research areas, angles and methods of Marxist philosophical research in the global era.

This report provides a brief account of the major reforms to higher education in China since 1949 and background reforms since 1978, focusing on recent trends and perspectives.

(2002). Contemporary Development of Marxist Philosophy in China. Educational Philosophy and Theory: Vol. 34, No. 2, pp. 145-154.

This chapter analyzes the People’s Republic of China’s ecological problems and policies. It is organized into four parts. The first deals with ideas and concerns to protect the environment in pre-1949 China. In the second, China’s modernization programs of technological advancement and their impact on the environment are discussed. The third part discusses the government’s strategies and policies to counter environmental degradation. The fourth part analyzes the linkage between China’s environmental problems and those of the rest of the world and makes suggestions as to what more could be done.