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Preparation and Characterization of Lung-targeting Cefquinome-loaded PLGA Microspheres

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Journal of Wuhan University of Technology(Materials Science) 2017年第2期32卷 494-499页

作者：张瑞丽 HAO Zhihui ding zhaopeng 吕志华 School of Medicine and Pharmacy Ocean University of China Qingdao 266003 China Agricultural Bio-pharmaceutical Laboratory Qingdao Agricultural University Qingdao 266109 China

We developed poly lactic-co-glycolic acid（PLGA） microspheres loaded with cefquinome and tested their effectiveness in a mouse model. The microspheres were prepared by optimizing several key parameters such as PLGA molecular weight, drug/polymer ratio, internal water volume and ethyl acetate. Drug loading efficiency, stability, in vitro release and tissue distribution in mouse were evaluated. The average particle size of the microspheres was 27.84 μm. The drug loading efficiency was 64.57%. The in vitro release of cefquinome from microspheres after 4 h was about 40% compared with over 90% for the drug alone. The concentration of cefquinome in lung reached 25 μg/g 0.25 h after injection, and kept at 10 μg/g 4 h after injection. However, the concentration of cefquinome was very low in other organs even 0.25 h after injection. In conclusion, Cefquinome-loaded PLGA microspheres are compatible as an effective lung-targeting drug delivery system and have a good sustained release efficacy.

关键词： PLGA microspheres cefquinome lung-targeting sustained release size mouse

Preparation of Lung Targeting Microspheres of Gelatin Ceftiofur Alkali

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Journal of Wuhan University of Technology(Materials Science) 2013年第2期28卷 400-405页

作者：郝智慧 ZHAO Yongda 曲宝涵 WU Haoting HAO Lihua ding zhaopeng YANG Fenfang Laboratory of Chemical and Biological College of Chemistry and Pharmacy Qingdao Agricultural University Qingdao Continent Pharmaceutical Co. Ltd. China Institute of Veterinary Drug Control

Gelatin ceftiofur alkali microsphere was prepared to observe its characteristics and evaluate preservation conditions. The glutaraldehyde was increased and the carboxylic methyl chitosan was added to improve the microsphere. The experimental results show microspheres have a better morphology surface and fairly regular structure with 4% glutaraldehyde. The average particle size is 15.84 gm and particle size distribution is narrow which shows a good uniformity. Microsphere size was affected by the stirrer speed, dosing ratio and curing degree. The greater drug loaded is, the better microspheres loading is; but with the increase of drug loading rate, the entrapment efficiency increases first and then decreases. The drug release rate of the microsphere is 24.90% in 0.5 h and 84.90% in 48 h, when CMC-GMs with 4% curing agent is 32.03% in 0.5 h and 88.44% in 48 h. So Gms embedding of ceftiofur alkali are better than CMC-GM. The stability tests show that strong light, high temperature, high humidity have a great influence on the microspheres.

关键词： gelatin ceftiofur alkali microsphere lung targeting microsphere morphology

Erlang(2)过程的风险分析与美式看跌期权

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应用概率统计 2006年第4期22卷 372-386页

作者：丁钊鹏北京联合大学商务学院北京100025

在经典的风险理论中涉及到的索赔风险是服从复合Poission过程的,与之不同,我们考虑Er- lang(2)风险过程．Erlang(2)分布往往见诸于控制理论中,这里它作为索赔发生间隔时间的分布被引入了．本文中,我们介绍一个与破产时刻、破产前时刻的... 详细信息

在经典的风险理论中涉及到的索赔风险是服从复合Poission过程的,与之不同,我们考虑Er- lang(2)风险过程．Erlang(2)分布往往见诸于控制理论中,这里它作为索赔发生间隔时间的分布被引入了．本文中,我们介绍一个与破产时刻、破产前时刻的盈余以及破产时刻赤字有关的辅助函数φ(·),函数中涉及的这三个变量对风险模型的研究都是最基本也是最重要的．Willmot and Lin (1999)曾在古典连续时间风险模型之中研讨过这一函数．受Gerber and Shiu(1997)及Willmot and Lin(2000)在古典模型下的研究过程的启发,本文的一个重要结果就是找到破产前时刻的盈余以及破产时刻赤字的联合分布密度函数．更得益于Gerber and Landry(1998)及Gerber and Shiu (1999)的思想,我们应用以上的结果去寻求基础资产服从一定风险资产价格过程的美式看跌期权最优交易策略．

关键词： Erlang(2)过程古典风险模型破产时刻美式看跌期权

小学科学课堂教学行为的研究与分析——以16节公开课为例

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课程．教材．教法 2014年第6期34卷 72-78页

作者：张军霞丁朝蓬人民教育出版社综合理科室北京100081 人民教育出版社科研部北京100081

对小学科学课堂教学中教师行为与学生行为进行分类,形成小学科学课堂教学行为分类系统。在这一行为分类系统中,将教师行为分成四大类16个具体行为,将学生行为分成三大类10个具体行为。根据开发的行为系统,利用行为分析软件,对16节选自... 详细信息

对小学科学课堂教学中教师行为与学生行为进行分类,形成小学科学课堂教学行为分类系统。在这一行为分类系统中,将教师行为分成四大类16个具体行为,将学生行为分成三大类10个具体行为。根据开发的行为系统,利用行为分析软件,对16节选自科学教育年会的公开课进行量化的行为分析。通过分析发现,在小学科学课堂上,教师能够给学生留出较多用于研究和讨论的时间;但是,教师需要在提问和反馈策略上多下工夫,需要给小组集体研讨汇报提供更多的机会,需要控制学生操作活动次数,提高操作活动的质量。

关键词：小学科学教师行为学生行为行为分类

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杠杆风险与供给侧改革去杠杆研究

河南社会科学 2018年第1期26卷 97-102页

作者：丁钊鹏刘立新对外经贸大学金融学院北京100029 北京联合大学北京100101

在金融市场中,投资者借用金融杠杆博取高收益,同时也承担了过量的风险。在市场跌宕之中风险头寸逐步放大,投资者被迫抛售资产或者加杠杆以应对流动性枯竭,从对冲性融资演变到投机性融资、再演变到庞氏融资。通过杠杆融资的资产负债表分... 详细信息

在金融市场中,投资者借用金融杠杆博取高收益,同时也承担了过量的风险。在市场跌宕之中风险头寸逐步放大,投资者被迫抛售资产或者加杠杆以应对流动性枯竭,从对冲性融资演变到投机性融资、再演变到庞氏融资。通过杠杆融资的资产负债表分析,论述了金融杠杆对投资者绩效的影响与三类融资间的演变过程;应用金融机构在险价值理论分析金融资产价格与金融杠杆的螺旋式正负反馈,从而论述了金融危机的传导机制;最后结合国内杠杆状况从供给侧角度提出了去杠杆的可行之策。

关键词：金融杠杆融资在险价值去杠杆

Natural vibration and critical velocity of translating Timoshenko beam with non-homogeneous boundaries

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1523-1538页

作者： Yanan LI Jieyu ding Hu ding Liqun CHEN Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai Frontier Science Center of MechanoinformaticsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China School of Mathematics and Statistics Qingdao UniversityQingdao 266071Shandong ProvinceChina

In most practical engineering applications,the translating belt wraps around two fixed *** boundary conditions of the dynamic model are typically specified as simply supported or fixed *** this paper,non-homogeneous boundaries are introduced by the support *** the translating belt as the mechanical prototype,the vibration characteristics of translating Timoshenko beam models with nonhomogeneous boundaries are investigated for the first *** governing equations of Timoshenko beam are deduced by employing the generalized Hamilton's *** effects of parameters such as the radius of wheel and the length of belt on vibration characteristics including the equilibrium deformations,critical velocities,natural frequencies,and modes,are numerically calculated and *** numerical results indicate that the beam experiences deformation characterized by varying curvatures near the *** radii of the wheels play a pivotal role in determining the change in trend of the relative difference between two beam *** the results unearths that the relative difference in equilibrium deformations between the two beam models is more pronounced with smaller-sized *** the two wheels are of equal size,the critical velocities of both beam models reach their respective *** addition,the relative difference in natural frequencies between the two beam models exhibits nonlinear variation and can easily exceed 50%.Furthermore,as the axial velocities increase,the impact of non-homogeneous boundaries on modal shape of translating beam becomes more *** dealing with non-homogeneous boundaries is challenging,beam models with non-homogeneous boundaries are more sensitive to parameters,and the differences between the two types of beams undergo some interesting variations under the influence of non-homogeneous boundaries.

关键词： translating beam Timoshenko beam non-homogeneous boundary natural frequency critical velocity

Whittle’s Index Based Sensor Scheduling for Multiprocess Systems Under DoS Attacks

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Journal of Systems Science & Complexity 2024年第1期37卷 329-350页

作者： CAI Zai ding Kemi Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China.

In this paper,the authors consider how to design defensive countermeasures against DoS attacks for remote state estimation of multiprocess *** each system,a sensor will measure its state and transmits the data packets through an unreliable channel which is vulnerable to be jammed by an *** limited communication bandwidth,only a subset of sensors are allowed for data transmission,and how to select the optimal one to maximize the accuracy of remote state estimation is the focus of the proposed *** authors first formulate this problem as a Markov decision process and investigate the existence of optimal ***,the authors demonstrate the piecewise monotonicity structure of optimal *** the difficulty of obtaining an optimal policy of large-scale problems,the authors develop a suboptimal heuristic policy based on the aforementioned policy structure and Whittle’s ***,a closed form of the indices is derived in order to reduce implementation complexity of proposed scheduling policy and numerical examples are provided to illustrate the proposed developed results.

关键词： DoS attacks Kalman filter remote state estimation Whittle’s index.

Deep structure of the Southeast Asian curved subduction system and its dynamic process

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Journal of Oceanology and Limnology 2024年第3期42卷 701-704页

作者： Weiwei ding Key Laboratory of Submarine Geoscience&Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China

The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical *** on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was *** is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate *** work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.

关键词： curved subduction system deep structure material recycling dynamic process Southeast Asia

A vertical track nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 931-946页

作者： Meng LI Hu ding Shanghai Key Laboratory of Mechanics in Energy Engineering School of Mechanics and Engineering ScienceShanghai Frontier Science Center of MechanoinformaticsShanghai UniversityShanghai 200444China

Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping *** this paper,the dynamic design of a vertical track nonlinear energy sink(VTNES)with zero linear stiffness in the vertical direction is proposed and realized for the first *** motion differential equations of the VTNES coupled with a linear oscillator(LO)are *** the strong nonlinearity considered of the VTNES,the steady-state response of the system is analyzed with the harmonic balance method(HBM),and the accuracy of the HBM is verified *** this basis,the VTNES prototype is manufactured,and its nonlinear stiffness is *** damping effect and dynamic characteristics of the VTNES are studied theoretically and *** results show that the VTNES has better damping effects when strong modulation responses(SMRs)***,even for small-amplitude vibration,the VTNES also has a good vibration suppression *** sum up,in order to suppress the vertical vibration,an NES is designed and developed,which can suppress the vertical vibration within certain ranges of the resonance frequency and the vibration intensity.

关键词： track nonlinear energy sink(TNES) vertical direction gravity nonlinear stiffness harmonic balance method(HBM) vibration control