检索结果-南通市图书馆

Simulation of Daily Diffuse Solar Radiation Based on Three Machine Learning Models

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2020年第4期123卷 49-73页

作者： Jianhua Dong Lifeng Wu xiaogang liu Cheng Fan Menghui Leng Qiliang Yang Faculty of Agriculture and Food Kunming University of Science and TechnologyKunming650500China School of Hydraulic and Ecological Engineering Nanchang Institute of TechnologyNanchang330099China Jiangxi Key Laboratory of Hydrology-Water Resources and Water Environment Nanchang Institute of TechnologyNanchang330099China.

Solar radiation is an important parameter in the fields of computer modeling,engineering technology and energy *** paper evaluated the ability of three machine learning models,i.e.,Extreme Gradient Boosting(XGBoost),Support Vector Machine(SVM)and Multivariate Adaptive Regression Splines(MARS),to estimate the daily diffuse solar radiation(Rd).The regular meteorological data of 1966-2015 at five stations in China were taken as the input parameters(including mean average temperature(Ta),theoretical sunshine duration(N),actual sunshine duration(n),daily average air relative humidity(RH),and extra-terrestrial solar radiation(Ra)).And their estimation accuracies were subjected to comparative *** three models were first trained using meteorological data from 1966 to ***,the 2001-2015 data was used to test the trained machine learning *** results show that the XGBoost had better accuracy than the other two models in coefficient of determination(R2),root mean square error(RMSE),mean bias error(MBE)and normalized root mean square error(NRMSE).The MARS performed better in the training phase than the testing phase,but became less accurate in the testing phase,with the R2 value falling by 2.7-16.9%on *** contrast,the R2 values of SVM and XGBoost increased by 2.9-12.2%and 1.9-14.3%,*** trailing slightly behind the SVM at the Beijing station,the XGBoost showed good performance at the rest of the stations in the two *** the training phase,the accuracy growth is small but *** addition,the XGBoost had a slightly lower RMSE than the SVM,a signal of its edge in ***,the three machine learning models can estimate the daily Rd based on local inputs and the XGBoost stands out for its excellent performance and stability.

关键词： Diffuse solar radiation extreme gradient boosting multivariate adaptive regression splines statistical indices support vector machine

Effects of deficit irrigation on soil microorganisms and growth of Arabica coffee(Coffea arabica L.)under different shading cultivation modes

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6期14卷 99-108页

作者： xiaogang liu Rongmei Li Zhihui Han Qiliang Yang Zeyin Jiang Faculty of Modern Agricultural Engineering Kunming University of Science and TechnologyKunming 650500China

In the present research,the rational coupling mode of irrigation and shading cultivation for rapid growth and water saving of young Arabica coffee shrubs was investigated from 2016 to *** full irrigation(FI,1.2Ep)as the control,the effects of three deficit irrigation(DI)(DI1,DI2 and DI3,with 1.0Ep,0.8Ep and 0.6Ep)on soil water content,temperature,microorganism population density,photosynthetic characteristics,canopy structure and dry mass of Arabica coffee under three shading cultivation modes(S0,monoculture coffee;S1,mild shading cultivation,intercropping with one line of Arabica coffee and one line of castor(Ricinus communis L.);S2,severe shading cultivation,intercropping with one line of Arabica coffee and two lines of castor)were investigated using plot *** to FI,DI1 not obviously changed the population density of soil bacteria and actinomycetes,but increased net photosynthetic rate(Pn),crown area and dry mass of Arabica coffee by 7.0%,9.53%and 10.46%,*** addition,DI1 also decreased total radiation under canopy(TRUC)by 5.51%.DI2 and DI3 reduced the population density of soil bacteria,fungi and actinomycetes ranging 8.94%-47.06%.Compared to S0,S1 increased the population density of soil fungi,bacteria and actinomycetes by 13.99%,30.77%and 9.72%,respectively.S1 also increased Pn,transpiration rate(Tr),leaf apparent radiation use efficiency(ARUE),leaf area index(LAI)and dry mass by 9.29%,5.39%,60.98%,10.31%and 30.02%,***1S1 obtained the highest Pn and dry mass and higher LAI and the lowest ***1S1 increased Pn,ARUE and dry mass by 18.98%,72.37%and 62.90%respectively but decreased TRUC by 21.77%when compared to ***,DI1S1 was found to be the rational mode of irrigation and shading cultivation for young Arabica coffee.

关键词： Arabica coffee shading cultivation Ricinus communis L. irrigation quantity soil microorganism canopy structure light-water regulation

Influences of alternate partial root-zone irrigation and urea rate on water-and nitrogen-use efficiencies in tomato

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 2017年第6期10卷 94-102页

作者： liu xiaogang Li Fusheng Zhang Fucang Cai Huanjie Yang Qiliang Faculty of Modern Agricultural Engineering Kunming University of Science and TechnologyKunming 650500China College of Agriculture Guangxi UniversityNanning 530005China Key Laboratory for Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education Northwest A&F UniversityYanglingShaanxi 712100China

Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use *** investigate the advantage of alternate partial root-zone irrigation(AI)on water-and nitrogen(N)-use efficiencies of tomato modified by water and N management,taking conventional irrigation(CI)as the control,the effects of AI on root morphology and activity,fruit yield and water and N use efficiency were studied using pot *** were four combinations of irrigation levels and growing stages of tomato for AI,***_(1)(high water(W_(H))from blooming to harvest stage(BHS)),AI_(2)(W_(H)from blooming to fruit setting stage(BFS)and low water(W_(L))at the harvest stage(HS)),AI_(3)(W_(L)at BFS and W_(H)at HS)and AI_(4)(W_(L)at BHS)at three urea rates,*** urea rate(NL),middle urea rate(N_(M))and high urea rate(N_(H))in the form of *** quotas for W_(H)and W_(L)in AI at BFS or HS were 80%and 60%of that in CI,*** to CI,AI decreased water consumption by 16.0%-33.1%and increased water use efficiency of yield(WUE_(y))and dry mass(WUE_(d))by 6.7%-11.9%and 10.2%-15.9%,***_(1)did not decline yield,total N uptake(TNU)and N use efficiency(NUE)*** to NL,N_(M)enhanced tomato yield,TNU,WUE_(y)and WUE_(d)by 28.5%,35.3%,22.6%and 16.3%,*** to CINL,AI_(1)N_(M)reduced water consumption by 12.5%,but increased tomato yield,TNU,WUE_(y)and WUE_(d)by 35.5%,58.4%,54.4%and 53.7%,***,AI_(1)can improve water use efficiency and total N uptake of tomato simultaneously at medium urea rate.

关键词： alternate partial root-zone irrigation nitrogen level nitrogen uptake tomato water use efficiency yield

Recent advances in morphology control of platinum catalysts toward oxygen reduction reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2024年第3期18卷 330-355页

作者： Shun CHEN Yanru liu xiaogang FU Wanglei WANG State Key Laboratory of Solidification Processing Atomic Control and Catalysis Engineering LaboratorySchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Oral and Maxillofacial Reconstruction and Regeneration National Clinical Research Center for Oral DiseasesShaanxi Key Laboratory of StomatologyDepartment of Dental MaterialsSchool of StomatologyThe Fourth Military Medical UniversityXi’an 710032China

Exploring advanced platinum (Pt)-based electrocatalysts is vital for the widespread implementation of proton exchange membrane fuel cells (PEMFCs). Morphology control represents an effective strategy to optimize the behavior of Pt catalysts. In this work, an attempt is made to comprehensively review the effect of morphology control on the catalytic behavior of catalysts in the oxygen reduction reaction (ORR). First, the fundamental physicochemical changes behind morphology control, including exposing more active sites, generating appropriate lattice strains, and forming different crystalline surfaces, are highlighted. Then, recently developed strategies for tuning the morphologies of electrocatalysts, including core-shell structures, hollow structures, nanocages, nanowires, and nanosheets, are comprehensively summarized. Finally, an outlook on the future development of morphology control of Pt catalysts is presented, including rational design strategies, advanced in situ characterization techniques, novel artificial intelligence, and mechanical learning. This work is intended to provide valuable insights into designing the morphology and technological innovation of efficient redox electrocatalysts in fuel cells.

关键词： morphology platinum catalysts electrocatalysis ORR PEMFC

茶饮团体心理辅导改善大学生心理健康状况效果

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国学校卫生 2024年第6期45卷 826-830页

作者：邓旭阳林启修朱斯妤刘晓刚徐柳青贺婧王志琳东南大学心理健康教育中心江苏南京211189 南京工业大学心理健康教育指导中心淮安市教育局办公室东南大学人文学院南京医科大学医学人文研究院

目的探讨茶饮团体心理辅导对大学生抑郁、社交回避及苦恼、应对方式、自尊的干预效果,为促进学生心理健康发展提供参考依据。方法 2021年3—6月,采用方便抽样方法从南京市某高校通过海报方式招募46名大学生进行干预研究,干预组、对照组... 详细信息

目的探讨茶饮团体心理辅导对大学生抑郁、社交回避及苦恼、应对方式、自尊的干预效果,为促进学生心理健康发展提供参考依据。方法 2021年3—6月,采用方便抽样方法从南京市某高校通过海报方式招募46名大学生进行干预研究,干预组、对照组各23名学生,辅导时间为每周2.5 h,共6周。干预组运用茶类知识讲解、观察学习、具身体验、情绪表达、人际互助与情感支持、文化礼俗与生活融入等整合式“茶饮冲泡体验”的团体辅导方式进行两期辅导;对照组在干预结束后进行一次茶饮团体心理辅导。采用Wilcoxon差异性检验和Mann-Whitney U检验分别进行组内和组间的比较,采用χ^(2)检验进行抑郁检出率的比较。结果干预前干预组和对照组在积极应对、消极应对、自尊、社交回避及苦恼得分差异均无统计学意义(Z值分别为-1.20,-0.33,-0.35,1.31,P值均>0.05)。干预后干预组和对照组在积极应对方式、自尊和社交回避及苦恼3个方面(27.70±5.60,22.05±4.30;30.52±3.63,28.27±4.06;7.43±7.38,13.64±6.79)差异均有统计学意义(Z值分别为-3.31,-2.10,3.22,P值均0.05)。1年后的追踪结果显示,干预组和对照组在社交回避及苦恼得分(6.57±6.21,14.16±9.22)、抑郁检出率(21.7%,52.2%)差异均有统计学意义(Z/χ^(2)值分别为2.70,4.57,P值均<0.05)。结论茶饮团体心理辅导能改善大学生人际交往与情绪状态,自尊水平和应对方式。可通过茶饮团体心理辅导改善大学生心理健康状况。

关键词：团体处理精神卫生干预性研究茶学生

玉米雄性不育突变体ms20s2的表型鉴定与基因定位

在线全文

学校读者我要写书评

暂无评论

植物遗传资源学报 2024年第2期25卷 171-183页

作者：周玉强曹枭雄王婧刘伊凡王红武李坤刘小刚黄长玲李树强刘小龙张亚男于飞荣马庆胡小娇安徽农业大学生命科学院/作物抗逆育种与减灾国家地方联合工程实验室合肥230036 中国农业科学院作物科学研究所/作物分子育种国家工程研究中心北京100081 新疆华夏农业有限公司乌鲁木齐830000

玉米突变体male-sterile 20s2(ms20s2)是在玉米自交系KWS49中发现的一个无花粉型雄性不育突变体。与野生型相比,ms20s2突变体花药细小且颜色偏浅,花药内未观察到花粉。扫描电镜观察表明,与野生型相比,9叶期突变体ms20s2的花药中未观察... 详细信息

玉米突变体male-sterile 20s2(ms20s2)是在玉米自交系KWS49中发现的一个无花粉型雄性不育突变体。与野生型相比,ms20s2突变体花药细小且颜色偏浅,花药内未观察到花粉。扫描电镜观察表明,与野生型相比,9叶期突变体ms20s2的花药中未观察到正在减数分裂的花粉母细胞;抽雄后突变体花药壁外部角质层形成异常,内部未观察到乌式体结构。观察不同发育阶段花药的石蜡切片发现,在S6-S7时期,与野生型相比,ms20s2突变体花药部分中间层和绒毡层细胞发生异常分裂,导致花药壁萎缩,花粉母细胞无法正常进行减数分裂,最终造成花粉母细胞死亡,产生雄性不育表型。遗传分析表明,突变体ms20s2的雄性不育表型受单个隐性核基因控制。利用玉米10K SNP芯片对F2定位群体进行基因型分析,初步将该突变位点定位在玉米2号染色体长臂上6.21 Mb区段内。进一步精细定位将该区间缩小到了590 kb,区间包含一个已知的蛋白编码基因MS32(Zm00001eb106620)。对MS32基因进行测序分析,在突变体MS32基因4号外显子上发现了一段3166 bp的大片段插入,可能影响了MS32蛋白功能,造成ms20s2的花药发育异常和雄性不育的表型。等位测验结果表明,突变体ms20s2是雄性不育基因MS32的新等位突变体。组织表达分析发现该基因在玉米花药中特异表达,且仅在花药发育的S6和S7时期表达量较高,进一步验证了该基因在玉米花药绒毡层和中间层细胞发育过程中的重要作用。

关键词：玉米突变体ms20s2 雄性不育基因定位表型分析

同方期刊数据库博看期刊

Construction and regulation of imidazo[1,5-a]pyridines with AIE characteristics via iodine mediated Csp^(2)-H or Csp-H amination

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第10期32卷 3083-3086页

作者： Jun Zhang Mengyao She Lang liu Mengdi liu Zhaohui Wang Hua liu Wei Sun xiaogang liu Ping liu Shengyong Zhang Jianli Li Ministry of Education Key Laboratory of Synthetic and Natural Functional Molecule Chemistry College of Chemistry&Materials ScienceNorthwest UniversityXi’an 710127China Lab of Tissue Engineering Provincial Key Laboratory of Biotechnology of ShaanxiMinistry of Education Key Laboratory of Resource Biology and Modern BiotechnologyThe College of Life SciencesFaculty of Life and Health ScienceNorthwest UniversityXi’an 710127China Fluorescence Research Group Singapore University of Technology and DesignSingapore 487372Singapore

The widespread applications of aggregation-induced emission luminogens(AIEgens)inspire the creation of AIEgens with novel structures and *** this work,we focused on the direct and efficient synthesis of a new type of AIEgens,imidazo[1,5-a]pyridicne derivatives,via iodine mediated cascade oxidative Csp^(2)–H or Csp–H amination route from phenylacetylene or styrenes under mild *** resulted compounds showed excellent AIE characteristics with tunable maximum emissions,attractive bioimaging performance,and potential anti-inflammatory activity,which exert broad application prospects in material,biology,medicine,and other relevant areas.

关键词： Aggregation-induced emission(AIE) Imidazo[1,5-a]pyridicnes Iodine Bioimaging Anti-inflammatory

Outcomes of patients awaiting lung transplantation after the implementation of donation after brain death at a single Chinese center

在线全文

学校读者我要写书评

暂无评论

Frontiers of Medicine 2022年第5期16卷 760-765页

作者： Yuling Yang Xinnan Xu Ming liu Yanfeng Zhao Yongmei Yu xiaogang liu Chang Chen Gening Jiang Wenxin He Department of Thoracic Surgery Shanghai Pulmonary HospitalSchool of MedicineTongji UniversityShanghai 200092China Department of Cardiothoracic Surgery Zhangzhou Affiliated Hospital of Fujian Medical UniversityZhangzhou 363000China

oluntary contribution has become the only source of donor lungs in China since *** elaborate the outcomes of patients awaiting lung transplantation(LTx)after the implementation of donation after brain death,we performed a retrospective study that encompassed 205 patients with end-stage lung disease who registered for LTx at Shanghai Pulmonary Hospital from January 1,2015 to January 1,2021.A total of 180 patients were enrolled in the *** median waiting time was 1.25 *** lung disease(ILD)(103/180,57.2%)and chronic obstructive pulmonary disease(COPD)(56/180,31.1%)were the most common diseases in our study *** mean pulmonary artery pressure(mPAP)of patients in the died-waiting group was higher than that of the survivors(53.29+21.71 mmHg vs.42.11+18.58 mmHg,P-0.002).The mortality of patients with ILD(34/103,33.00%)was nearly twice that of patients with COPD(10/56,17.86%)while awaiting LTx(P-0.041).In the died-waiting group,patients with ILD had a shorter median waiting time than patients with COPD after being listed(0.865 months vs.4.720 months,P-0.030).ILD as primary disease and mPAP>35 mmHg were two significant independent risk factors for waitlist mortality,with hazard ratios(HR)of 3.483(95%CI 1.311-9.111;P-0.011)and 3.500(95%CI 1.435-8.536;P=0.006).Hence,LTx is more urgently needed in patients with ILD and pulmonary hypertension.

关键词： lung transplantation donation after brain death waitlist

Strong π-π stacking interactions led to the mis-assignment of dimer emissions to the monomers of 1-acetylpyrene

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2019年第3期30卷 601-604页

作者： Shuangshuang Long Weijie Chi Lu Miao Qinglong Qiao xiaogang liu Zhaochao Xu CAS Key Laboratory of Separation Science for Analytical Chemistry Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Fluorescence Research Group Singapore University of Technology and Design

Understanding relationships between molecular structures and fluorescent properties is critical to enable rational deployment of fluorophores. 1-Acetyl pyrene is an important pyrene-derivative, used extensively as an environment-sensitive probe. In the past, the fluorescence of 1-acetylpyrene was considered to be polarity-sensitive with a large positive solvatochromism, and its monomer emissions were believed in the range of 410-470 nm. In this paper, our experimental and theoretical studies showed that the monomer fluorescence of 1-acetylpyrene is centered at ～390 nm,which is similar to that of pyrene dyes and not polarity-sensitive. Previously observed "monomer emission" has been re-assigned to that of dimers, which represent the dominant existence form of 1-acetylpyrene in the solution phase,as a result of strong intermolecular π-π stacking interactions.

关键词： 1-Acetylpyrene Pyrene Aggregation Monomer Excimer