检索结果-南通市图书馆

IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 418-429页

作者： Yanzheng zhu Nuo Xu Fen Wu xinkai Chen Donghua Zhou IEEE College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China College of Mechanical Engineering and Automation Huaqiao UniversityXiamen 361021China Department of Mechanical and Aerospace Engineering North Carolina State UniversityRaleigh NC 27695 USA Department of Electronic and Information Systems Shibaura Institute of TechnologySaitama 337-8570Japan

In this paper, the issues of stochastic stability analysis and fault estimation are investigated for a class of continuoustime Markov jump piecewise-affine(PWA) systems against actuator and sensor faults. Firstly, a novel mode-dependent PWA iterative learning observer with current feedback is designed to estimate the system states and faults, simultaneously, which contains both the previous iteration information and the current feedback mechanism. The auxiliary feedback channel optimizes the response speed of the observer, therefore the estimation error would converge to zero rapidly. Then, sufficient conditions for stochastic stability with guaranteed performance are demonstrated for the estimation error system, and the equivalence relations between the system information and the estimated information can be established via iterative accumulating representation.Finally, two illustrative examples containing a class of tunnel diode circuit systems are presented to fully demonstrate the effectiveness and superiority of the proposed iterative learning observer with current feedback.

关键词： Current feedback fault estimation iterative learning observer Markov jump piecewise-affine system

Effects of tillage on soil nitrogen and its components from rice-wheat fields in subtropical regions of China

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2022年第3期15卷 146-152页

作者： Siyuan Cui xinkai zhu Guangqiao Cao Key Laboratory of Modern Agricultural Equipment Ministry of AgricultureNanjing Institute of Agricultural MechanizationMinistry of Agriculture and Rural AffairsNanjing 210014China Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou UniversityYangzhou 225009JiangsuChina

It is of great significance to explore the effects of different tillage practices on total nitrogen and its components in rice-wheat rotation farmland.The experiment was carried out in Jiangyan County,Jiangsu Province of China,and a total of four treatments were set up:minimum tillage(MT),rotary tillage(RT),conventional tillage(CT),and conventional tillage without straw retention(CT0).The total nitrogen(TN),light fraction nitrogen(LFN),heavy fraction nitrogen(HFN),particulate nitrogen(PN),and mineral-associated nitrogen(MN)in 0-20 cm soil were determined.The results show that MT increased TN concentration by2.26%-27.57%compared with the other treatments in 0-5 cm soil,but it lost this advantage in 5-10 cm and 10-20 cm soil.MT altered the concentration of LFN by 6.03%-95.86%,of HFN by 1.68%-20.75%,of PN by 12.58%-96.83%,and of MN by−1.73%-9.83%as compared to RT,CT,and CT0 in 0-5 cm soil,respectively.With the deepened of soil depth,the concentration of TN,LFN,HFN,PN,and MN decreased quickly in MT,which was lower than that in RT and CT at 10-20 cm soil depth.Straw return increased the concentration of TN and its components in 0-20 cm soil.The concentration of TN was extremely significantly positively correlated with that of LFN,HFN,PN,and MN(p<0.01).The variation of TN was significantly positively correlated with that of LFN,HFN,PN,and MN(p<0.01),and LFN showed the highest sensitivity to tillage practice.In general,minimum tillage combined with straw retention increased the concentration of soil TN and its components in topsoil.LFN was the best indicator to indicate the change in soil total nitrogen affected by tillage practice.

关键词： rice-wheat rotation soil active nitrogen components light fraction nitrogen heavy fraction nitrogen particulate nitrogen mineral-associated nitrogen

Evaluation of ecosystem service of straw return to soil in a wheat field of China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2021年第1期14卷 192-198页

作者： Siyuan Cui Guangqiao Cao xinkai zhu Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops Yangzhou UniversityYangzhou 225009JiangsuChina Key Laboratory of Modern Agricultural Equipment Ministry of AgricultureNanjing Institute of Agricultural MechanizationMinistry of Agriculture and Rural AffairsNanjing 210014China Joint International Research Laboratory of Agriculture and Agri-Product Safety the Ministry of Education of ChinaYangzhou UniversityYangzhou 225009JiangsuChina

Crop straw is an important natural resource in China because it is rich in nutrients.When returned to fields after harvests,the straw can improve soil quality and the next crop’s yield.Evaluating the economic values of the main ecological services of a farmland ecosystem while implementing the straw return technique can be a more systematic and comprehensive approach to better understand the contribution of straw return to the development of ecological agriculture.Based on the data of a field experiment established in 2010 with varying numbers of years of straw return,four ecological services,i.e.,agricultural product and industrial raw materials,atmospheric regulation and purification,soil nutrient accumulation,and water conservation,were selected to estimate a net ecosystem service value(ESV)of a wheat field’s ecosystem services.Agro-ecosystem service appraisal theories were applied to estimate the economic value of each service.Results showed that straw returning improved the total ESV in the wheat system.Compared to the no straw return treatment,1 year,3 years,5 years or 7 years of straw returning altered the economic value of the agricultural product and industrial raw materials(EVAIM)by-5.93%to 7.84%and improved atmospheric regulation(EVAR)by 13.66%-30.80%,soil nutrient accumulation(EVSNA)by 59.87%-233.31%and water conservation(EVWC)by 2.60%-13.26%.The total ESV of wheat plots with 1-7 years of straw returning was 3.67%-27.41%higher than that with no straw return,and the total ESV increased with the increase in years of straw return.The proportion of EVAIM out of the total ESV in this wheat field system was highest(accounted for 47.09%-55.64%),followed by EVAR and EVWC.The value of EVSNA was the lowest.However,the proportion of EVSNA was higher than that of water conservation after the fifth year of straw return.In general,the adoption of continuous straw returning in a wheat field ecosystem is ecologically valuable.The results can inform the development and implementation of ecological compensation policie

关键词： ecosystem service value rice-wheat rotation straw returning farmland ecosystem economic value ecological service function

Analytical Analysis and Performance Characterization of Brushless Doubly Fed Induction Machines Based on General Air-gap Field Modulation Theory

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electrical Engineering 2021年第3期7卷 4-19页

作者： Peng Han Ming Cheng xinkai zhu Zhe Chen Ansys Inc.San JoseCA 95134USA School of Electrical Engineering Southeast UniversityNanjing 210096China Department of Electrical Engineering North China Electric Power UniversityBaoding 071003China Department of Energy Technology Aalborg UniversityAalborg 9220Denmark

Air-gap magnetic field modulation has been widely observed in electric machines.In this study,we present an analytical analysis and performance characterization of brushless doubly fed induction machines(BDFIMs)fed by two independent converters from the perspective of air-gap field modulation.The spiral-loop winding is studied in detail as an example to show the generalized workflow that can also be used to analyze other short-circuited rotor winding types,such as nested-loop and multiphase double-layer windings.Magnetic field conversion factors are introduced to characterize the modulation behavior of special rotor windings and facilitate their comparison in terms of cross-coupling capability,average torque,and harmonic content of the air-gap flux density waveforms.The stator magnetomotive force(MMF),rotor MMF,and resultant air-gap MMF are considered,based on which the closed-form inductance formulas are derived,and the torque equation is obtained along with the optimal current angle for maximum torque operation by using the virtual work principle.The design equations are then developed for the initial sizing and geometry scaling of the BDFIMs.Transient finite element analysis and experimental measurements are performed to validate the analysis.

关键词： AC machines air gap magnetic field spatial harmonic frequency domain modulation rotor windings

Estimation of biomass in wheat using random forest regression algorithm and remote sensing data

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Crop Journal 2016年第3期4卷 212-219页

作者： Li'ai Wang Xudong Zhou xinkai zhu Zhaodi Dong Wenshan Guo Key Laboratory of Crop Genetics and Physiology of Jiangsu Province Yangzhou University Information Engineering College of Yangzhou University

Wheat biomass can be estimated using appropriate spectral vegetation indices.However,the accuracy of estimation should be further improved for on-farm crop management.Previous studies focused on developing vegetation indices,however limited research exists on modeling algorithms.The emerging Random Forest(RF) machine-learning algorithm is regarded as one of the most precise prediction methods for regression modeling.The objectives of this study were to(1) investigate the applicability of the RF regression algorithm for remotely estimating wheat biomass,(2) test the performance of the RF regression model,and(3) compare the performance of the RF algorithm with support vector regression(SVR) and artificial neural network(ANN) machine-learning algorithms for wheat biomass estimation.Single HJ-CCD images of wheat from test sites in Jiangsu province were obtained during the jointing,booting,and anthesis stages of growth.Fifteen vegetation indices were calculated based on these images.In-situ wheat above-ground dry biomass was measured during the HJ-CCD data acquisition.The results showed that the RF model produced more accurate estimates of wheat biomass than the SVR and ANN models at each stage,and its robustness is as good as SVR but better than ANN.The RF algorithm provides a useful exploratory and predictive tool for estimating wheat biomass on a large scale in Southern China.

关键词： Above-ground dry biomass Triticum aestivum Vegetation indices Wheat

基于端部绕组模块的定子励磁无刷电机冷却方法

在线全文

学校读者我要写书评

暂无评论

东南大学学报（自然科学版） 2024年第1期54卷 240-250页

作者：花为张志恒朱新凯王玉彬李祥林东南大学电气工程学院南京210096 华北电力大学(保定)电力工程系保定071003 中国石油大学(华东)新能源学院青岛266580 青岛大学电气工程学院青岛266071

为了提升定子励磁无刷电机的冷却能力,提出了一种基于端部绕组模块的定子励磁无刷电机冷却方法.在电机端部绕组和定子铁芯叠片端部的间隙中插入端部绕组冷却(EWC)模块,以减小定子绕组热点区域和冷却介质之间的间隙,从而提高端部绕组的... 详细信息

为了提升定子励磁无刷电机的冷却能力,提出了一种基于端部绕组模块的定子励磁无刷电机冷却方法.在电机端部绕组和定子铁芯叠片端部的间隙中插入端部绕组冷却(EWC)模块,以减小定子绕组热点区域和冷却介质之间的间隙,从而提高端部绕组的冷却能力.对非重叠式集中绕组长度计算模型进行改进,评估采用EWC模块前后电机定子电枢绕组长度的变化,分析EWC模块的电导率对电机定子损耗的影响.采用计算流体动力学(CFD)模型,对比EWC模块在不同铜耗和励磁源损耗密度下的冷却性能.结果表明,采用EWC模块可以使端部绕组的稳态温升降低约50%,热态时的绕组电阻降低7.51%,从而改善了定子的冷却条件.

关键词：定子励磁无刷电机端部绕组冷却设计热态电阻

Systematic annotation of conservation states provides insights into regulatory regions in rice

在线全文

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2022年第12期49卷 1127-1137页

作者： xinkai Zhou Tao zhu Wen Fang Ranran Yu Zhaohui He Dijun Chen State Key Laboratory of Pharmaceutical Biotechnology Schoolof Life SciencesNanjing UniversityNanjingJiangsu 210023China

Plant genomes contain a large fraction of noncoding sequences.The discovery and annotation of conserved noncoding sequences(CNSs)in plants is an ongoing challenge.Here we report the application of comparative genomics to systematically identify CNSs in 50 well-annotated Gramineae genomes using rice(Oryza sativa)as the reference.We conduct multiple-way whole-genome alignments to the rice genome.The rice genome is annotated as 20 conservation states(CSs)at single-nucleotide resolution using a multivariate hidden Markov model(Cons HMM)based on the multiple-genome alignments.Different states show distinct enrichments for various genomic features,and the conservation scores of CSs are highly correlated with the level of associated chromatin accessibility.We find that at least 33.5%of the rice genome is highly under selection,with more than 70%of the sequence lying outside of coding regions.A catalog of 855,366 regulatory CNSs is generated,and they significantly overlapped with putative active regulatory elements such as promoters,enhancers,and transcription factor binding sites.Collectively,our study provides a resource for elucidating functional noncoding regions of the rice genome and an evolutionary aspect of regulatory sequences in higher plants.

关键词： Rice Comparative genomics Conserved noncoding sequences(CNSs) Conservation states(CSs)

缓释肥类型及其运筹方式对弱筋小麦产量及品质的影响

在线全文

学校读者我要写书评

暂无评论

麦类作物学报 2024年第6期44卷 758-769页

作者：李丽贾文欣徐昊李春燕丁锦峰朱敏郭文善朱新开江苏省作物遗传生理重点实验室/扬州大学小麦研究中心江苏扬州225009 江苏省粮食作物现代产业技术协同创新中心江苏扬州225009 教育部农业与农产品安全国际合作联合实验室江苏扬州225009

为探究缓释肥类型及施用模式对小麦产量和品质的调控作用及机制,以弱筋小麦扬麦33为供试材料,选取3种类型(8种品牌)的缓释肥[包膜型缓释肥(S1~S5)、合成型微溶性缓释肥(S6)、化学抑制剂型缓释肥(S7、S8)]作为供试氮源,设置缓释肥一次性... 详细信息

为探究缓释肥类型及施用模式对小麦产量和品质的调控作用及机制,以弱筋小麦扬麦33为供试材料,选取3种类型(8种品牌)的缓释肥[包膜型缓释肥(S1~S5)、合成型微溶性缓释肥(S6)、化学抑制剂型缓释肥(S7、S8)]作为供试氮源,设置缓释肥一次性基施(M1)和基施60%+返青期追施40%(M2)两种施肥模式,常规尿素施肥(基肥∶壮蘖肥∶拔节肥∶孕穗肥为5∶1∶2∶2)为对照(CK),分析了相同施氮水平下缓释肥类型及其运筹方式对小麦产量、氮素积累转运、氮效率、品质和效益的影响。结果表明,与CK相比,同一品牌缓释肥在不同施肥模式下小麦产量、开花期和成熟期氮素积累、籽粒氮素积累、花前氮素转运量及转运效率、花后氮素积累及其对籽粒的贡献率和氮利用效率均表现为M2>CK>M1。其中,M2模式下小麦显著增产的缓释肥依次为S6>S1>S2>S3>S8。M1模式下各处理小麦籽粒品质指标均符合弱筋小麦国家标准;M2模式下除S2、S6外,其余缓释肥的小麦籽粒品质指标均符合弱筋品质要求。除M2S5外,其余处理产值及净效益均表现为M2>CK>M1。综合认为,本试验条件下,S1(硫包膜型)、S3(树脂包膜型)、S8(抑制型)缓释肥基施60%+返青期追施40%可实现弱筋小麦产量、品质、氮效率和经济效益的协同提升。

关键词：弱筋小麦缓释肥产量氮素积累转运品质经济效益

Bacteroides-derived isovaleric acid enhances mucosal immunity by facilitating intestinal IgA response in broilers

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2023年第3期14卷 1252-1273页

作者： xinkai Wang Yifan Hu Xiaoyan zhu Liyuan Cai Muhammad Zahid Farooq Xianghua Yan State Key Laboratory of Agricultural Microbiology Hubei Hongshan LaboratoryFrontiers Science Center for Animal Breeding and Sustainable ProductionCollege of Animal Sciences and TechnologyHuazhong Agricultural UniversityWuhan 430070HubeiChina Department of Animal Sciences University of Veterinary and Animal Sciences(Jhang Campus)Lahore 54000Pakistan

Background:The interaction between nutrition and immunity plays a vital role in nutrient digestion,absorption,and metabolism during poultry production.Recent studies showed that the gut microbiota contributes to the development of intestinal mucosal immunity.However,the mechanisms by which gut microbes regulate this process remain unclear.Methods:We compared the intestinal mucosal immunity and gut microbiota of Arbor Acre broilers AA(lower mucosal immunity)and Chinese native Wuliang Mountain Black-bone chickens(WLMB)(higher mucosal immunity)using 16S rDNA sequencing,transcriptomic analysis,and immunoglobulin A(IgA)antibody repertoire sequencing.We then combined 16S rDNA sequencing with transcriptomics to identify the key microbes and found that they were positively correlated with IgA production.Next,we transplanted candidate microbes into 1-day-old broiler to explore their role in intestinal mucosal immunity.Finally,we verified the function of candidate microbial metabolites in regulating the immune function of macrophages and the intestinal-epithelial cells(IECs)using in vitro experiments.Results:WLMB performs stronger mucosal immunity than AA,including higher IgA levels,more diverse IgA antibody repertoire,and higher bacterial affinity.Bacteroides was identified as the key microbes related to the intestinal IgA response.Bacteroides transplantation could increase IgA concentration in the duodenal contents by enhancing the expression of IgA,polymeric immunoglobin receptor(PIgR),B cell-activating factor of the TNF family(BAFF),and activation-induced cytidine deaminase(AID)in the duodenum.Additionally,Bacteroides-derived isovaleric acid promoted M2 macrophage polarization of macrophage via mTOR/PPAR-γ/STAT3 signaling pathways and regulated the immunologic function of IECs to produce cytokines,including interleukin(IL)-10,IL-4,BAFF,and transforming growth factor-beta(TGF-β),thus promoting IgA production in B cells by facilitating AID expression.Conclusion:Our study revealed that Bacteroides modulate the intestinal

关键词： Bacteroides Chicken IgA Intestinal health Isovaleric acid Macrophage

碎石含量对三峡库区坡耕地土壤氮磷流失特征的影响

在线全文

学校读者我要写书评

暂无评论

农业工程学报 2024年第3期40卷 127-137页

作者：赵冰琴胡鑫凯高儒章施伟豪张兴凤朱万庆夏振尧许文年三峡库区地质灾害教育部重点实验室(三峡大学) 宜昌443002 水泥基生态修复技术湖北省工程研究中心(三峡大学) 宜昌443002

坡耕地是三峡库区水土流失的主要来源,导致土壤养分的损失,严重影响库区生态环境建设与社会经济可持续发展。库区坡耕地土壤浅薄化和砾质化特征明显,但目前对含碎石坡耕地土壤侵蚀和养分流失特征的研究尚不多见。该研究通过设置3个降雨... 详细信息

坡耕地是三峡库区水土流失的主要来源,导致土壤养分的损失,严重影响库区生态环境建设与社会经济可持续发展。库区坡耕地土壤浅薄化和砾质化特征明显,但目前对含碎石坡耕地土壤侵蚀和养分流失特征的研究尚不多见。该研究通过设置3个降雨梯度(60、90、120 mm/h)和4种碎石含量(0、10%、20%、30%),开展人工模拟降雨试验,分析各试验条件下含碎石土壤产流产沙和氮磷流失特征。结果表明:1)碎石主要通过改变土壤结构以增大产流产沙量来促进氮磷流失,而对相应流失速率与流失浓度的变化规律影响较小,不同碎石含量下泥沙产量的变异系数更高,且泥沙中不同碎石含量下的氮磷流失量显著性差异更强(P<0.05);2)泥沙中累计磷流失量略微大于氮流失量,有效磷几乎不随泥沙流失,有效氮约占全氮流失量的15%;径流中氮素流失量几乎为磷素的10倍且以有效氮为主,占总氮流失量的75%,有效磷占总磷流失量的25%;3)不同碎石含量下有效氮流失规律大致相同,径流中硝态氮约占有效氮流失量的70%,而泥沙中则以铵态氮为主,约占65%;4)不同碎石含量下土壤中氮磷元素均以随侵蚀产沙流失为主,累计产沙量与氮磷元素随侵蚀产沙流失量均在20%碎石含量下达到极大值,10%碎石含量下流失量相对较小,因此泥沙库区坡耕地氮磷流失防治应以减少侵蚀产沙为主,注意大雨暴雨多发季节的水质监测与施肥控制。同时可对土中碎石进行清除使其保持在不高于10%水平。研究结果可为三峡库区含碎石坡耕地水土流失防治和氮磷流失治理提供科学参考。

关键词：土壤侵蚀碎石含量雨强产流产沙氮磷流失回归分析