检索结果-南通市图书馆

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

不确定环境下供应链库存管理综述

物流工程与管理 2024年第2期46卷 43-46,39页

作者：鲁梦楠汤齐天津工业大学经济与管理学院天津300387

库存管理是供应链管理的重要环节,受到诸多研究者的青睐,也取得了很多重要的研究成果。然而在现实中,很多研究理论无法落实到地,模型的理想化、不确定环境的复杂性都使得研究方案差强人意。文中提供一个新的视角,将问题按不确定因素的... 详细信息

库存管理是供应链管理的重要环节,受到诸多研究者的青睐,也取得了很多重要的研究成果。然而在现实中,很多研究理论无法落实到地,模型的理想化、不确定环境的复杂性都使得研究方案差强人意。文中提供一个新的视角,将问题按不确定因素的种类分类,对以往的文献进行回顾总结,并讨论了未来可能的研究方向。

关键词：不确定环境供应链库存管理

Theoretical Investigation of the Mechanism of Rh(III)-catalyzed Annulation of 2-Biphenylboronic Acid with Activated Alkene

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2023年第2期39卷 276-282页

作者： lu nan MIAO Chengxia LAN Xiaozheng College of Chemistry and Material Science Shandong Agricultural UniversityTaian271018P.R.China

The mechanism is investigated for Cp^(tBu)Rh(OH)_(2)-catalyzed annulation of 2-biphenylboronic acid with three activated alkenes using M06-2X *** reaction comprises transmetalation via two steps and following C-H activation producing reactive Rh-biphenyl complex with two Rh—Cσ*** the coordination/insertion of alkenes,respective fused or bridged cyclic products are yielded depending on different alkenes accompanied by the release of *** promotion of Cp^(tBu)Rh(OH)_(2) lies in the barrier decrease of transmetalation and C-H activation ready for coordination/insertion ensuring the smooth progress of common rate-limiting reductive *** stereoselective transfer and ring rotation are specific for benzoquinone and *** role of Rh(III)catalyst and release of Rh(I)is supported by Multiwfn analysis on frontier molecular orbital(FMO)of specific transiton states(TSs)and Mayer bond order(MBO)value of vital bonding,breaking.

关键词： Annulation Activated alkene Transmetalation Coordination/insertion M06-2X functional

Kinetics of non-catalyzed hydrolysis of tannin in high temperature liquid water

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

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第5期9卷 401-406页

作者： Li-li lu Xiu-yang lu nan MA Institute of Pharmaceutical Engineering Department of Chemical and Biochemical Engineering Zhejiang University Hangzhou 310027 China

High temperature liquid water(HTLW) has drawn increasing attention as an environmentally benign medium for organic chemical reactions,especially acid-/base-catalyzed reactions. Non-catalyzed hydrolyses of gallotannin and tara tannin in HTLW for the simultaneous preparation of gallic acid(GA) and pyrogallol(PY) are under investigation in our laboratory. In this study,the hydrolysis kinetics of gallotannin and tara tannin were determined. The reaction is indicated to be a typical consecutive first-order one in which GA has formed as a main intermediate and PY as the final product. Selective decomposition of tannin in HTLW was proved to be possible by adjusting reaction temperature and time. The present results provide an important basic data and reference for the green preparation of GA and PY.

关键词： High temperature liquid water Gallotannin Tara tannin Non-catalyzed hydrolysis Kinetics

^(96)Zr和^(96)Ru结构的协变密度泛函理论研究

在线全文

学校读者我要写书评

暂无评论

中国科学：物理学、力学、天文学 2024年第9期54卷 112-124页

作者：荣宇婷吴先业吕炳楠尧江明广西师范大学物理科学与技术学院桂林541004 广西核物理与核技术重点实验室桂林541004 江西师范大学物理与通信电子学院南昌330022 中国工程物理研究院研究生院北京100193 中山大学物理与天文学院珠海519082

近期,同量异位素^(96)Zr和^(96)Ru的重离子碰撞实验研究发现初态原子核的形变和中子皮厚度对碰撞末态的粒子流、多重数分布等观测量产生很大影响.协变密度泛函理论作为研究微观核结构的理论模型之一,能够使用同一组有效相互作用统一自... 详细信息

近期,同量异位素^(96)Zr和^(96)Ru的重离子碰撞实验研究发现初态原子核的形变和中子皮厚度对碰撞末态的粒子流、多重数分布等观测量产生很大影响.协变密度泛函理论作为研究微观核结构的理论模型之一,能够使用同一组有效相互作用统一自洽描述所有原子核的基态性质,如形变和中子皮厚度等.基于协变密度泛函理论拓展得到的超越平均场方法被成功用于研究原子核的低能集体激发谱学性质,是构建实验能谱与内禀形变之间微观联系的先进方法.目前^(96)Zr的谱学实验和核结构理论研究表明,它可能同时存在三轴和八极形变.因此,本文将首先介绍同时打破轴对称和空间反射对称的多维形状约束协变密度泛函理论及其超越平均场方法;其次给出平均场近似下^(96)Zr和^(96)Ru的基态形变和中子皮厚度;最后,讨论多维形变空间的超越平均场方法对^(96)Zr和^(96)Ru低激发态性质的描述.

关键词：原子核形状八极关联超越平均场方法同量异位素

Landscape Ecology:Coupling of Pattern,Process,and Scale

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2011年第4期21卷 385-391页

作者： FU Bojie LIANG Di lu nan State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Landscape ecology provides new theoretical frameworks and methodologies for understanding complex ecological phenomena at multiple *** of landscape ecology focus on understanding the dynamics of eco-logical patterns and processes,and highlight the integration of multiple *** this paper,we discussed the problems and challenges that landscape ecology is currently facing,emphasizing the limitations of current methods used to describe dynamic landscape patterns and *** suggested that the focus should be on the integration of ground-based observation,mobile monitoring,transect survey,and remote-sensing monitoring,as well as improved coupling of experimental and model *** addition,we outlined the research frontiers in landscape ecology,including scaling,integrated pattern and process modeling,and regional ***,a brief review of pat-tern-process-scale coupling studies in China was *** concluded by pointing out that pattern-process-scale interactions,correlations between natural,economic,and social processes,and the coupling of human and natural systems will be major research areas in landscape ecology in the future.

关键词： landscape ecology pattern and process scale integrated model regional synthesis research

An Error Equivalent Model of Revolute Joints with Clearances for Antenna Pointing Mechanisms

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2018年第2期31卷 97-105页

作者： Quan Liu Sheng-nan lu Xi-lun Ding School of Mechanical Engineering and Automation Beihang University

Joint clearances in antenna pointing mechanisms lead to uncertainty in function deviation. Current studies mainly focus on radial clearance of revolute joints, while axial clearance has rarely been taken into consideration. In fact, own?ing to errors from machining and assembly, thermal deformation and so forth, practically, axial clearance is inevitable in the joint. In this study, an error equivalent model(EEM) of revolute joints is proposed with considering both radial and axial clearances. Compared to the planar model of revolute joints only considering radial clearance, the journal motion inside the bearing is more abundant and matches the reality better in the EEM. The model is also extended for analyzing the error distribution of a spatial dual?axis("X–Y" type) antenna pointing mechanism of Spot?beam antennas which especially demand a high pointing accuracy. Three case studies are performed which illustrates the internal relation between radial clearance and axial clearance. It is found that when the axial clearance is big enough, the physical journal can freely realize both translational motion and rotational motion. While if the axial clearance is limited, the motion of the physical journal will be restricted. Analysis results indicate that the consideration of both radial and axial clearances in the revolute joint describes the journal motion inside the bearing more precise. To further validate the proposed model, a model of the EEM is designed and fabricated. Some suggestions on the design of revolute joints are also provided.

关键词： Error modeling Joint clearances Antenna pointing mechanism Radial clearance Axial clearance

Current prophylactic strategies against hepatitis B virus recurrence after liver transplantation

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第20期15卷 2489-2499页

作者： Li Jiang Li-Sheng Jiang nan-Sheng Cheng lu-nan Yan Department of Liver and Vascular Surgery Liver Transplantation Center West China Hospital of Sichuan University Chengdu 610041 Sichuan Province China Department ofBiliary Surgery West China Hospital of Sichuan University Chengdu 610041 Sichuan Province China

Prophylactic strategies against hepatitis B virus(HBV) recurrence after liver transplantation(LT) are essential for patients with HBV-related *** LT, lamivudine(LAM) was proposed to be down-graded from first-to second-line *** contrast, adefovir dipivoxil(ADV) has been approved not only as first-line therapy but also as rescue therapy for patients with LAM ***, combination of ADV and LAM may result in lower risk of ADV resistance than ADV *** new drugs such as entecavir, telbivudine and tenofovir, are probably candidates for the treatment of hepatitis-B-surface-antigen-positive patients awaiting *** LT, low-dose intramuscular hepatitis B immunoglobulin(HBIG), in combination with LAM, has been regarded as the most cost-effective regimen for the prevention of post-transplant HBV recurrence in recipients without pretransplant LAM resistance and rapidly accepted in many transplant *** the introduction of new antiviral drugs, new hepatitis B vaccine and its new adjuvants, post-transplant HBIG-free therapeutic regimens with new oral antiviral drug combinations or active HBV vaccination combined with adjuvants will be promising, particularly in those patients with low risk of HBV recurrence.

关键词： Hepatitis B virus Liver transplantation Recurrence Prophylaxis Hepatitis B immunoglobulin

The angular momentum and parity projected multidimensionally constrained relativistic Hartree-Bogoliubov model

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

Communications in Theoretical Physics 2022年第1期74卷 64-76页

作者： Kun Wang Bing-nan lu CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Graduate School of China Academy of Engineering Physics Beijing 100193China

Nuclear deformations are fundamentally important in nuclear *** recently developed a multidimensionally constrained relativistic Hartree-Bogoliubov(MDCRHB)model,in which all multipole deformations respecting the V_(4) symmetry can be considered *** this work we extend this model by incorporating the angular momentum projection and parity projection to restore the rotational and parity symmetries broken in the mean-field *** projected MDCRHB(p-MDCRHB)model enables us to connect certain nuclear spectra to exotic intrinsic shapes such as triangles or *** present the details of the method and an exemplary calculation for ^(12)*** develop a triangular moment constraint to generate the triangular configurations consisting of three α clusters arranged as an equilateral *** resulting ^(12)C spectra are consistent with that from a triangular rigid rotor for large separations between the α *** also calculate the B(E2)and B(E3)values for low-lying states and find good agreement with the experiments.

关键词： nuclear physics beyond mean field density functional nuclear clustering

在线全文

学校读者我要写书评

暂无评论

不平衡电压下光伏逆变器直接功率控制仿真

计算机仿真 2024年第4期41卷 92-96页

作者：刘国旗卢倩楠长安大学陕西西安710016

为了有效避免不平衡电压下光伏逆变器产生的波动,提出不平衡电压下光伏逆变器直接功率控制方法。分析光伏逆变器的特点,通过三相逆变器拓扑结构,设计直流侧与交流侧的滤波器参数,结合不平衡电压情况,构建逆变器并网模式下的数学模型,得... 详细信息

为了有效避免不平衡电压下光伏逆变器产生的波动,提出不平衡电压下光伏逆变器直接功率控制方法。分析光伏逆变器的特点,通过三相逆变器拓扑结构,设计直流侧与交流侧的滤波器参数,结合不平衡电压情况,构建逆变器并网模式下的数学模型,得出不平衡电压对光伏逆变器产生的影响。引入调节参数实时调整自然振荡频率,准确提取正负序分量以及相位信息。通过多目标协调控制方法组建多目标函数,运用粒子群算法对多目标函数寻优处理,输出最优协调系数,使光伏逆变器工作在最优状态,实现光伏逆变器直接功率控制。仿真结果表明,所提方法能够准确提取谐波分量,在功率控制中能够保持一定的稳定性。

关键词：不平衡电压下光伏逆变器直接功率控制调节参数粒子群算法