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Superconvergence Study of the Direct Discontinuous Galerkin Method and Its Variations for Diffusion Equations

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Communications on Applied Mathematics and Computation 2022年第1期4卷 180-204页

作者： Yuqing Miao Jue Yan xinghui zhong School of Mathematical Sciences Zhejiang UniversityHangzhou 310027China Department of Mathematics Iowa State UniversityAmesIA 50011USA

In this paper,we apply the Fourier analysis technique to investigate superconvergence properties of the direct disontinuous Galerkin(DDG)method(Liu and Yan in SIAM J Numer Anal 47(1):475-698,2009),the DDG method with the interface correction(DDGIC)(Liu and Yan in Commun Comput Phys 8(3):541-564,2010),the symmetric DDG method(Vidden and Yan in Comput Math 31(6):638-662,2013),and the nonsymmetric DDG method(Yan in J Sci Comput 54(2):663-683,2013).We also include the study of the interior penalty DG(IPDG)method,due to its close relation to DDG *** estimates are carried out for both P2 and P3 polynomial *** investigating the quantitative errors at the Lobatto points,we show that the DDGIC and symmetric DDG methods are superior,in the sense of obtaining(k+2)th superconvergence orders for both P2 and P3 *** order of(k+2)is also observed for the IPDG method with P3 polynomial *** errors are sensitive to the choice of the numerical flux coefficient for even degree P2 approximations,but are not for odd degree P3 *** experiments are carried out at the same time and the numerical errors match well with the analytically estimated errors.

关键词： Direct discontinuous Galerkin methods Superconvergence Fourier analysis Diffusion equation

High Order Finite Difference WENO Methods with Unequal-Sized Sub-Stencils for the Degasperis-Procesi Type Equations

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Communications in Computational Physics 2022年第3期31卷 913-946页

作者： Jianfang Lin Yan Xu Huiwen Xue xinghui zhong School of Mathematical Sciences Zhejiang UniversityHangzhouZhejiang 310058P.R.China School of Mathematical Sciences University of Science and Technology of ChinaHefeiAnhui 230026P.R.China

In this paper,we develop twofinite difference weighted essentially non-oscillatory(WENO)schemes with unequal-sized sub-stencils for solving the Degasperis-Procesi(DP)andµ-Degasperis-Procesi(µDP)equations,which contain nonlinear high order derivatives,and possibly peakon solutions or shock *** introducing auxiliary variable(s),we rewrite the DP equation as a hyperbolic-elliptic system,and theµDP equation as afirst order *** we choose a linearfinite difference scheme with suitable order of accuracy for the auxiliary variable(s),and twofinite difference WENO schemes with unequal-sized sub-stencils for the primal *** WENO scheme uses one large stencil and several smaller stencils,and the other WENO scheme is based on the multi-resolution framework which uses a se-ries of unequal-sized hierarchical central *** with the classical WENO scheme which uses several small stencils of the same size to make up a big stencil,both WENO schemes with unequal-sized sub-stencils are simple in the choice of the stencil and enjoy the freedom of arbitrary positive linear *** advantage is that thefinal reconstructed polynomial on the target cell is a polynomial of the same de-gree as the polynomial over the big stencil,while the classicalfinite difference WENO reconstruction can only be obtained for specific points inside the target ***-merical tests are provided to demonstrate the high order accuracy and non-oscillatory properties of the proposed schemes.

关键词： High order accuracy weighted essentially non-oscillatory schemes Degasperis-Procesi equation µ-Degasperis-Procesi equation finite difference method multi-resolution

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卷烟工艺空调节能运行策略及效益分析

现代工业经济和信息化 2024年第4期14卷 196-199页

作者：曹贤新何雪辉钟兴辉刘龙涛曹勖睿江西中烟工业有限责任公司赣州卷烟厂江西赣州341000

分析了卷烟厂工艺空调现阶段所使用的整体控制方法,提出了节能运行策略和控制优化措施,实现了工艺空调平稳控制的同时降低系统耗能。通过效果测算得出,所述策略满足对工艺空调的控制要求,可降低空调系统能耗,为其他企业工艺空调节能策... 详细信息

分析了卷烟厂工艺空调现阶段所使用的整体控制方法,提出了节能运行策略和控制优化措施,实现了工艺空调平稳控制的同时降低系统耗能。通过效果测算得出,所述策略满足对工艺空调的控制要求,可降低空调系统能耗,为其他企业工艺空调节能策略提供参考。

关键词：卷烟加工工艺空调节能策略

N/S co-doped carbon nanosheet bundles as high-capacity anode for potassium-ion battery

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Nano Research 2022年第3期15卷 2040-2046页

作者： Jinhui Cao Jiang zhong Hanjiao Xu Shengyang Li Hongli Deng Tao Wang Ling Fan xinghui Wang Lei Wang Jian Zhu Bingan Lu Xidong Duan Hunan Key Laboratory of Two-Dimensional Materials State Key Laboratory for Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China School of Physics and Electronics Hunan UniversityChangsha 410082China College of Physics and Information Engineering Institute of Micro-Nano Devices and Solar CellsFuzhou UniversityFuzhou 350108China

Potassium-ion batteries(PIBs)are of academic and economic significance,but still limited by the lack of highly active electrode materials for de-/intercalation of large-radius K ***,an interconnected nitrogen/sulfur co-doped carbon nanosheep bundle(N/S-CSB)was proposed as the potassium ions storage *** rich co-doping of nitrogen/sulfur of N/S-CNB with three-dimensional hierarchical bundled array structure yields distensible interlayer spaces to buffer the volume expansion during K+insertion/extraction,offers more electrochemical active sites to obtain a high specific capacity,and provides efficient channels for fast ion/electron ***,the N/S-CSB anode achieved high reversible specific capacity of 365 mAh/g obtained at 50 mA/g after 200 cycles with a coulombic efficiency(CE)close to 100%,high rate performance and long cycle ***,the in-situ Raman spectra indicated outstanding reaction kinetics of as-prepared N/S-CSB anode.

关键词： potassium-ion battery anode carbon nanosheet bundles N/S co-doping high capacity long cycle

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不同建筑分层空调系统风口布置的优化研究

暖通空调 2018年第4期48卷 100-107页

作者：程远达杨晋明张兴惠杜震宇太原理工大学

通过实验数据验证数学模型后,模拟研究了分层空调系统应用于不同类型建筑空间时风口布置对环境热舒适性和系统节能潜力的影响。结果表明:当分层空调系统应用于小型建筑空间时,需要注意回风口的诱导作用对室内气流组织的影响,避免形成"... 详细信息

通过实验数据验证数学模型后,模拟研究了分层空调系统应用于不同类型建筑空间时风口布置对环境热舒适性和系统节能潜力的影响。结果表明:当分层空调系统应用于小型建筑空间时,需要注意回风口的诱导作用对室内气流组织的影响,避免形成"冷量短路"现象而引起热舒适问题;当分层空调系统应用于水平跨度较大的高大建筑空间时,应尽可能将送风口围绕人体活动区域均匀布置,以提高建筑下部空间气流组织的均匀性和环境热舒适性;将回风口布置在人体活动区域温度较低的位置,能够有效减小分层空调系统的制冷机组负荷;同时,增强室内空气沿外围护结构的贴附热羽流流动,也有利于提高系统的节能潜力。

关键词：分层空调建筑空间风口布置热舒适冷负荷节能

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精细化控制预混柜片烟出柜流量的研究与应用

新技术新工艺 2020年第4期 50-53页

作者：刘赐德刘忠胤陈健李元发钟兴辉江西中烟工业有限责任公司赣州卷烟厂江西赣州341000

针对某卷烟厂制丝车间预混到片烟加料工艺中,由于预混柜出柜流量与加料工序流量存在着不匹配,造成出柜底带、传送带、除杂设备等多次启停,影响设备性能,加大设备损耗的问题。从预混柜、传送带的容量出发,结合各个品牌烟叶叶组不同配方,... 详细信息

针对某卷烟厂制丝车间预混到片烟加料工艺中,由于预混柜出柜流量与加料工序流量存在着不匹配,造成出柜底带、传送带、除杂设备等多次启停,影响设备性能,加大设备损耗的问题。从预混柜、传送带的容量出发,结合各个品牌烟叶叶组不同配方,在保证正常加工前提下,建立了预混柜出柜流量与片烟加料需求流量相匹配模型。通过理论值进行过料测试,统计相关数据,并对出料底带频率进行优化,降低了设备的启停次数,完善了片烟的加工工艺。

关键词：出柜流量片烟加料预混柜除杂设备流量匹配优化模型

A laser synthesis of vanadium oxide bonded graphene for high-rate supercapacitors

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Journal of Energy Chemistry 2020年第10期29卷 174-178页

作者： Jun Tang Linfei Zhang Xiongwei zhong xinghui Wang Feng Pan Baomin Xu School of Advanced Materials Peking University Shenzhen Graduate SchoolPeking UniversityShenzhen 518055GuangdongChina Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhen 518055GuangdongChina Institute of Micro/Nano Devices and Solar Cells School of Physics and Information EngineeringFuzhou UniversityFuzhou 350108FujianChina

Graphene is a type of promising electrode material for high-energy and high-power density supercapacitors,but its electrochemical performance is greatly limited by the restacking *** this work,we reported a facile approach to synthesis graphene with chemically bonded vanadium oxide(VOx)nanoparticles and demonstrated that chemically-bonded VOxnanoparticles can effectively prevent the graphene sheets from restacking and hence improve the electrochemical *** capacitance of VOxbonded graphene increases to 272 F/g compared to 183 F/g of pristine graphene in 1 M H3PO4 aqueous electrolyte at 2 A/*** VOx-bonded graphene also showed improved rate capability in both H3PO4 and ionic liquid *** capacitance retention increases to 54.5%from 28.5%at 100 A/g(compare to2 A/g)in H3PO4 and increases to 65.1%from 46.3%at 2 A/g(compare to 0.2 A/g)in neat ionic liquid.A high energy density of 84.4 Wh/kg is obtained within the voltage window of 4 V in ionic *** at a high-power density of 1000 W/kg,the VOx-bonded graphene shows a high energy density of 47.3 Wh/kg.

关键词： Supercapacitors Restacking Vanadium oxides Laser reduced graphene

Comparing the Diagnostic Criteria for Gestational Diabetes Mellitus of World Health Organization 2013 with 1999 in Chinese Population

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Chinese Medical Journal 2015年第1期128卷 125-127页

作者： Weiwei Zhu Huixia Yang Yumei Wei Zilian Wang Xuelan Li Hairong Wu Nan Li Meihua Zhang xinghui Liu Hua Zhang Yunhui Wang Jianmin Niu Yujie Gan Liruo zhong Yunfeng Wang Anil Kapur Department of Obstetrics and Gynecology Peking University First Hospital Beijing 100034 China Department of Obstetrics and Gynecology First Affiliated Hospital of Sun Yat-sen University Guangzhou Guangdong 510080 China Department of Obstetrics and Gynecology First Affiliated Hospital of Medical ColLege of Xi'an Jiaotong University Xi'an Shaanxi 710061 China Department of Obstetrics and Gynecology Aviation General Hospital Beijing 100025 China Department of Obstetrics and Gynecology Tongzhou Maternal and Child Health Hospital of Beijing Beijing 101101 China Department of Obstetrics and Gynecology Maternal and Child Health Hospital of Taiyuan Taiyuan Shanxi 030012 China Department of Obstetrics and Gynecology West China Second University Hospital Chengdu Sichuan 610041 China Department of Obstetrics and Gynecology First Affiliated Hospital of Chongqing Medical University Chongqing 400042 China Department of Obstetrics and Gynecology Sun Yat-sen Memorial Hospital of Sun Yat-sen University Guangzhou Guangdong 510120 China Department of Obstetrics and Gynecology Guangdong Women and Children Hospital Guangzhou Guangdong 510623 China Department of Obstetrics and Gynecology Boai Hospital of Zhongshan Zhongshan Guangdong 528403 China Department of Obstetrics and Gynecology Shenzhen People's Hospital Shenzhen Guangdong 518020 China Department of Obstetrics and Gynecology Miyunxian Hospital Beijing 101500 China World Diabetes Foundation Gentofte Denmark

INTRODUCTION Gestational diabetes mellitus （GDM） was earlier defined as ＂hyperglycemia first recognized during pregnancy＂ and has more recently been described by American Diabetes Association （ADA）（2012） as diabetes diagnosed during pregnancy that is not clearly overt diabetes. The hyperglycemia and adverse pregnancy outcomes study （HAPO） demonstrated that the risk of adverse maternal,fetal,and neonatal outcomes continuously increase as a function of maternal glycemia at 24-28 weeks,even within ranges previously considered normal for pregnancy.

关键词： Criteria Gestational Diabetes Mellitus Oral Glucose Tolerance Test

远程干预对居家脊髓损伤患者压力性损伤预防效果的系统评价

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中华护理杂志 2022年第13期57卷 1627-1633页

作者：陈桂莲王颖敏王彤钟丽容何杏辉贾萌萌李琨中山大学孙逸仙纪念医院康复科广州市510030 中山大学护理学院

目的系统评价远程干预在居家脊髓损伤患者压力性损伤预防中的应用效果,为临床干预提供循证依据。方法计算机检索中国生物医学文献数据库、中国知网、万方数据库、维普数据库、Cochrane Library、PubMed、Embase、Web of Science、Scopus... 详细信息

目的系统评价远程干预在居家脊髓损伤患者压力性损伤预防中的应用效果,为临床干预提供循证依据。方法计算机检索中国生物医学文献数据库、中国知网、万方数据库、维普数据库、Cochrane Library、PubMed、Embase、Web of Science、Scopus、ProQuest和BMJ Best Practice从建库到2021年8月收录的相关文献。由2名研究人员进行质量评价后,采用RevMan 5.3软件进行Meta分析。结果共纳入14篇文献,包括9项随机对照试验和5项类实验研究,共1582例患者。Meta分析结果显示,远程干预能降低居家脊髓损伤患者压力性损伤的发生率[RR=0.29,95%CI(0.20,0.43),P<0.001],提高患者的生活质量[SMD=0.94,95%CI(0.19,1.68),P=0.010]和满意度[SMD=0.86,95%CI(0.58,1.13),P<0.001];不良事件发生率比较,差异无统计学意义[RR=0.50,95%CI(0.20,1.27),P=0.140]。结论远程干预在居家脊髓损伤患者压力性损伤预防中是安全、可行的,能降低其压力性损伤的发生率,提高患者的生活质量和满意度。受纳入研究质量和数量的限制,上述结论尚需更多高质量的研究验证。

关键词：脊髓损伤压力性损伤远程干预系统评价循证护理学