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Development of a novel two-stage proportional valve with a pilot digital flow distribution

Frontiers of Mechanical Engineering 2021年第2期16卷 420-434页

作者： Qiang GAO Yuchuan ZHU changwen wu Yulei JIANG National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Pilot two-stage proportional valves are widely used in high-power hydraulic systems. For the purpose of improving the dynamic performance, reliability, and digitization of the traditional proportional valve, a novel two-stage proportional valve with a pilot digital flow distribution is proposed from the viewpoint of the dual nozzle-flapper valve’s working principle. In particular, the dual nozzle-flapper is decoupled by two high-speed on/off valves (HSVs). First, the working principle and mathematical model of the proposed valve are determined. Then, the influences of the control parameters (duty cycle and switching frequency) and structural parameters (fixed orifice’s diameter and main valve’s spring) on the main valve’s motion are analyzed on the basis of theory, simulation, and experiment. In addition, in optimizing the value of the fixed orifice’s diameter, a new design criterion that considers the maximum pressure sensitivity, flow controllability, and flow linearization is proposed to improve the balance between the effective displacement and the displacement fluctuation of the main valve. The new scheme is verified by simulations and experiments. Experimental results of the closed-loop displacement tracking have demonstrated that the delay time of the main valve is always within 3.5 ms under different working conditions, and the tracking error can be significantly reduced using the higher switching frequency. The amplitude–frequency experiments indicate that a −3 dB-frequency of the proposed valve can reach 9.5 Hz in the case of ±50% full scale and 15 Hz in the case of 0%–50% full scale. The values can be further improved by increasing the flow rate of the pilot HSV.

关键词： two-stage proportional valve digital flow distribution high-speed on off valve position tracking characteristic dynamic performance

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Expression Profile of Immune-Associated Genes in the Kidney of Cultured Large Yellow Croaker Larimichthys crocea in the East China Sea Area

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Journal of Ocean University of China 2016年第4期15卷 731-739页

作者： ZHAO Shujiang ZHAO Qian CHEN Yinghua LV Baoqiang wu Xiongfei LIU Huihui ZHU Aiyi wu changwen School of Marine Science and Technology Zhejiang Ocean University Zhoushan 316022 P. R. China Research Center for Translational Medicine East Hospital Tongji University Shanghai 200120 P. R. China Wenzhou Marine Environmental Monitoring Center Station Wenzhou 325013 P. R. China Ningbo Academy of Oceanology and Fisheries Ningbo 315012 P. R. China

To explore the effect of environment conditions on immune activity of fish, eight immune-associated genes responsible for innate immunity were selected from the Gen Bank, i.e. Pgrn-a, Ifit2, P-hepcidin, Lect2, β2m, Irf1, Il25 and Hsp96, and the m RNA expressions of them in the kidney of cultured large yellow croaker Larimichthys crocea in different sea areas in the East China Sea were examined with q PCR techniques. In the contrasts of immune-associated gene expression between areas and populations, significant differences were found, expression levels of these immune-associated genes were lower in the clear water area than in the poor water quantity area, and lower in May than in October. MY was more sensitive to environmental factors than DQ, which was coincident with the water quality in the culturing areas. Differential analyses of the expression levels of these immune-associated genes showed that significant up-regulation could be triggered by poor environmental factors. The expression patterns indicated that the expression levels of these genes were sensitive to ecological changes, thereby the immune-associated genes, especially Pgrn-a, Ifit2, β2m, Il25 and Hsp96, might serve as immediate and sensitive indicators of population immunologic vigor and ecosystem health. But the expression of immunity-associated genes at the level of gene transcription is highly influenced by multiple factors, and the exact causes or influencing factors of the up-regulation or down-regulation of these genes still need further thorough investigation.

关键词： immunity Kidney innate Immune Associated yellow cultured exact triggered populations

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Evaluation approaches of fish swimming performance

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Agricultural Sciences 2014年第2期5卷 106-113页

作者： Fukun Gui Ping Wang changwen wu Zhejiang Key Lab of Marine Aquaculture Facili-ties and Engineering Technology Zhejiang Ocean University Zhoushan China

Swimming speeds are the most important index for the evaluation of the fish swimming performance. The terminologies and classifications of the fish swimming performance were summarized in this paper. Taking into consideration of the widely used evaluation approaches of the fish swimming performance by different researchers, a recommended classification methodology of the fish swimming performance was proposed by the authors. And a new concept of the swimming speed, the Maximum Domed Swimming Speed (DSS), was introduced into this new classification framework together with a discussion on its calculation method and the practical significance. According to the classification system, the fish swimming speeds are classified into five categories: Optimum Swimming Speed, Maximum Sustained Swimming Speed, Critical Swimming Speed, Maximum Domed Swimming Speed, and Burst Swimming Speed. Other concepts of swimming speeds are generally merged into the above five categories, respectively. Furthermore, possible relevancies among the Maximum Sustained Swimming Speed (MSS), the Critical Swimming Speed (CSS), and the Maximum Domed Swimming Speed (DSS) were discussed. It was concluded that these three swimming speeds, in a sense, can be regarded as the equivalent indices for the evaluation of fish swimming performance.

关键词： Swimming performance Optimum Swimming Speed Maximum Sustained Swimming Speed Critical Swimming Speed Maximum Domed Swimming Speed Burst Swimming Speed

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A preliminary analysis of fishery resource exhaustion in the context of biodiversity decline

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Science China Earth Sciences 2016年第11期59卷 223-235页

作者： ZHAO ShuJiang Lü BaoQiang LI RuWei ZHU AiYi wu changwen School of Marine Science and Technology Zhejiang Ocean University Zhoushan 316022 China Marine Environmental Monitoring Central Station of Wenzhou State Oceanic Administration People's Republic of China Wenzhou 325013 China

Marine biodiversity in almost all oceans is being threatened at the genetic, species, and ecosystem levels. The marine ecosystem is being degraded and the extinction rate of marine organisms has accelerated. In this paper, the potential causes of fishery resource exhaustion in the East China Sea are analyzed, including the change in the stoichiometric composition of seawater with regard to the concentrations of N and P, toxic effects of marine pollution, marine habitat destruction, increased seawater temperatures caused by climate warming, ocean acidification, pressure from overfishing, and the spread of marine pathogenic bacteria. It is believed that the factors mentioned above have significant impact on the exhaustion of fishery resources in the East China Sea. However, considering the cumulative, synergistic, and superimposed effects as well as the amplification effects resulting from their interactions, the actual risk of ecological extinction of marine organisms might be even more severe than that previously estimated. Hence, ecosystem management and research focused on a single risk factor or influencing factor is not enough to prevent marine ecosystem degradation and fishery resource exhaustion. A comprehensive, systematic, effective, and ecosystem-based management policy is imperative for healthy and sustainable fishery development in the East China Sea.

关键词： Fishery resources Exhaustion Extinction Influencing factor Cumulative effect Superimposed effect Amplifi-cation effect

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Molecular cloning and transcriptional analysis of a NPY receptor-like in common Chinese cuttlefish Sepiella japonica

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Journal of Oceanology and Limnology 2018年第3期36卷 892-904页

作者： YANG Jingwen XU Yuchao XU Ke PING Hongling SHI Huilai LU Zhenming wu changwen WANG Tianming National Engineering Research Center for Facilitated Marine Aquaculture Marine Science CollegeZhejiang Ocean UniversityZhoushan 316022China Marine Fisheries Research Institute of Zhejiang Province Zhoushan 316022China

Neuropeptide Y(NPY) has a pivotal role in the regulation of many physiological processes. In this study, the gene encoding a NPY receptor-like from the common Chinese cuttlefish Sepiella japonica( SjNPYR-like) was identified and characterized. The full-length SjNPYR-like cDNA was cloned containing a 492-bp of 5′ untranslated region(UTR), 1 182 bp open reading frame(ORF) encoding a protein of 393 amino acid residues, and 228 bp of 3′ UTR. The putative protein was predicted to have a molecular weight of 45.54 kDa and an isoelectric point(pI) of 8.13. By informatic analyses, SjNPYR-like was identified as belonging to the class A G protein coupled receptor(GPCR) family(the rhodopsin-type). The amino acid sequence contained 12 potential phosphorylation sites and five predicted N-linked glycosylation sites. Multiple sequence alignment and 3D structure modeling were conducted to clarify SjNPYR bioinformatics characteristics. Phylogenetic analysis identifies it as an NPYR with identity of 33% to Lymnaea stagnalis NPFR. Transmembrane properties of SjNPYR-like were demonstrated in vitro using HEK293 cells and the p EGFP-N1 plasmid. Relative quantifi cation of SjNPYR-like mRNA level confi rmed a high level expression and broad distribution of SjNPYR-like in various tissues of female S. japonica. In addition, the transcriptional profile of SjNPYR-like in the brain, liver, and ovary during gonadal development was analyzed. The results provide basic understanding on the molecular characteristics of SjNPYR-like and its potentially physical functions.

关键词： Sepiella japonica NPY receptor-like growth reproduction gene expression

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MATHEMATICAL　MODEL　OF　OVERLAND　FLOW　AND　MECHANISM　OF　SOIL　CONSERVATION　FOR　FORESTED　STEEP　HILLSLOPE

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International Journal of Sediment Research 1995年第1期 56-64页

作者： wu changwen2 WANG Lixian3

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ（１）ＡｎａｌｙｔｉｃａｌＳｏｌｕｔｉｏｎｔ... 详细信息

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ（１）ＡｎａｌｙｔｉｃａｌＳｏｌｕｔｉｏｎｔｏｔｈｅＯｖｅｒｌａｎｄＦｌｏｗｏ...

关键词： Steep hillslope Overland flow Saint Venant Equation

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Isolation via enrichment and characterization of ten polymorphic microsatellite loci in the cuttlefish, Sepiella maindroni de Rochebruns

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Acta Oceanologica Sinica 2010年第6期29卷 121-124页

作者： wu changwen CHI Changfeng HE Guangyuan LU Zhenming XU Meiying Key Laboratory of Molecular Biophysics Ministry of Education China-UK HUST-RRes Genetic Engineering and Genomics Joint Laboratory Huazhong University of Science and Technology Wuhan 430074 China Marine Science School Zhejiang Ocean University Zhoushan 316004 China Zhejiang Dahaiyang Science and Technology CO. Ltd. Zhoushan 316004 China

Ten novel polymorphic microsatellite loci were developed using an enrichment and colony hybridization protocol and characterized for the cuttlefish,Sepiella *** was explored by using 30 individuals from the coastal waters of Zhanjiang,Guangdong province,China,in December *** number of alleles ranged from 5 to *** ranges of observed and expected heterozygosity were from 0.578 9 to 1.000 0 and 0.682 8 to 0.925 7,respectively,and the average polymorphic information content （P IC） was 0.778 *** microsatellite loci will certainly facilitate the detection of the genetic variation and population structure of ***.

关键词： SepieUa maindroni microsatellite DNA cuttlefish genetic variation

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中国、韩国1980～2006年能值足迹与能值承载力

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环境科学学报 2009年第10期29卷 2231-2240页

作者：赵晟吴常文浙江海洋学院海洋科学学院舟山316000

根据基于能值分析理论改进的生态足迹计算模型——能值足迹和能值承载力模型,在空间尺度上从地区一级上升到国家尺度,探讨能值足迹和能值承载力在国家层面上若干年时间序列的变化趋势,并以中国和韩国为例,对两国在1980～2006年(韩国1980... 详细信息

根据基于能值分析理论改进的生态足迹计算模型——能值足迹和能值承载力模型,在空间尺度上从地区一级上升到国家尺度,探讨能值足迹和能值承载力在国家层面上若干年时间序列的变化趋势,并以中国和韩国为例,对两国在1980～2006年(韩国1980～2004年)期间的能值足迹和能值承载力进行了计算与分析,探讨中国和韩国的可持续发展状况.结果表明,中国人均能值承载力由1980年的2.7362hm2下降到2006年的2.0547hm2,同时,人均能值足迹却由1980年的1.7715hm2上升到2006年的5.7903hm2.中国自1987年以来出现能值足迹赤字,且赤字数额逐年增加,到2006年已达到-3.7356hm2.韩国人均能值承载力由1980年度3.1871hm2下降到2004年度2.5271hm2,人均能值足迹由1980的1.1339hm2上升到2004年的4.2419hm2,韩国自1992年出现能值足迹赤字,之后虽有小幅波动,但总体趋势与中国类似,赤字数额逐年上升,到2004年已达-1.7147hm2.目前,中国已不能满足基本可持续性的要求,而韩国能够满足这一要求.

关键词：生态足迹能值足迹能值承载力模型中国韩国

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同光时期清政府对兵制改革的探索

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中国国家博物馆馆刊 2015年第3期 122-133页

作者：吴昌稳广东省博物馆广州510623

同光时期,清政府治下内忧与外患渐轻,政局趋稳,秩序渐定,政府开始对太平天国运动以来制兵和勇营并存的兵制进行调整,以堵塞兵外加兵、饷外加饷的漏卮。勇营本以补制兵之不足,由于在战争中表现远超绿营,由偏锋演变成主力,因此战后如何区... 详细信息

同光时期,清政府治下内忧与外患渐轻,政局趋稳,秩序渐定,政府开始对太平天国运动以来制兵和勇营并存的兵制进行调整,以堵塞兵外加兵、饷外加饷的漏卮。勇营本以补制兵之不足,由于在战争中表现远超绿营,由偏锋演变成主力,因此战后如何区处二者关系着实考验统治阶层的政治智慧。清朝中央政府和在战争中崛起的督抚将领,在兵勇去留和继续使用何种兵制这些关键问题上产生了诸多分歧,或出于公心,或出于私意,其中所呈现出的见解与思想十分耐人寻味。探讨此间朝野上下在兵制方面的改革思路与实际做法,可以了解晚清军事思想发展的一般过程,感受军队膨胀与军饷供应之间的矛盾,更能洞见晚清兵制改革的取径及其局限。

关键词：同光时期兵制改革军饷

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国家一级博物馆学术研究现状与能力建设研究——基于中国知网学术论文的检索结果

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中国博物馆 2019年第1期 67-72页

作者：吴昌稳广东省博物馆

博物馆的发展离不开学术研究工作的支撑。通过探讨2015-2017年3年间的国家一级博物馆的学术论文发表情况,围绕各馆论文刊发情况进行多角度的分析和对比,可以综合评估当前我国博物馆界的学术研究的能力,揭示示我国博物馆界学术研究的整... 详细信息

博物馆的发展离不开学术研究工作的支撑。通过探讨2015-2017年3年间的国家一级博物馆的学术论文发表情况,围绕各馆论文刊发情况进行多角度的分析和对比,可以综合评估当前我国博物馆界的学术研究的能力,揭示示我国博物馆界学术研究的整体情况,以发现问题、探索对策。

关键词：博物馆学术研究国家一级博物馆现状能力建设

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