检索结果-南通市图书馆

负载BMP-2 壳聚糖水凝胶在大鼠完全脱位牙再植愈合中的研究

在线全文

学校读者我要写书评

暂无评论

皖南医学院学报 2024年第4期43卷 361-364页

作者：胡通张珏朱秀安苑迎娇皖南医学院口腔医学院安徽芜湖241002 皖南医学院第一附属医院弋矶山医院口腔科安徽芜湖241001

目的:研究负载骨形态发生蛋白(BMP-2)壳聚糖水凝胶在大鼠脱位牙再植愈合中的成骨作用。方法:24只SD大鼠随机分为4组。A组为空白对照组,牙槽窝仅注入生理盐水;B组为实验对照组1,牙槽窝注入壳聚糖水凝胶;C组为实验对照组2,牙槽窝注入BMP-... 详细信息

目的:研究负载骨形态发生蛋白(BMP-2)壳聚糖水凝胶在大鼠脱位牙再植愈合中的成骨作用。方法:24只SD大鼠随机分为4组。A组为空白对照组,牙槽窝仅注入生理盐水;B组为实验对照组1,牙槽窝注入壳聚糖水凝胶;C组为实验对照组2,牙槽窝注入BMP-2试剂;D组为实验组,牙槽窝注入负载BMP-2的壳聚糖水凝胶。全麻下完整拔出大鼠上颌右侧中切牙,刮除牙周膜,拔除牙髓,根尖孔打入vitapex,玻璃离子封闭根尖孔,4组分别注入设定的试剂然后再植入牙槽窝并固定。2个月后取带有上颌前牙的牙槽骨,脱钙后包埋、切片、HE染色,光镜下观察各组样本中牙周膜愈合、骨性愈合、炎症性吸收的分值,应用SPSS 24.0软件对数据进行统计处理。结果:D组的牙周膜愈合分值高于A、B、C组,差异均有统计学意义(P0.05)。结论:负载BMP-2壳聚糖水凝胶能有效促进大鼠脱位牙再植后牙周缺损的修复。

关键词：牙周膜干细胞骨形态发生蛋白-2 壳聚糖水凝胶

“美丽中国中脊带”西南段可持续发展路径研究

在线全文

学校读者我要写书评

暂无评论

成都理工大学学报（社会科学版） 2024年第3期32卷 34-49页

作者：王珏王涵成都理工大学商学院成都610059 成都理工大学数字胡焕庸线研究院成都610059

东西部发展失衡问题是长期以来制约中国社会经济发展的结构性与全局性问题。在国家生态文明建设与乡村振兴战略实施背景下,建设“美丽中国中脊带”作为缩小东西部发展不平衡的战略抓手具有重要的现实意义。“中脊带”西南段是我国西部... 详细信息

东西部发展失衡问题是长期以来制约中国社会经济发展的结构性与全局性问题。在国家生态文明建设与乡村振兴战略实施背景下,建设“美丽中国中脊带”作为缩小东西部发展不平衡的战略抓手具有重要的现实意义。“中脊带”西南段是我国西部大开发战略与“一带一路”倡议的重要发展区域,然而当地有限的自然与社会承载能力与政策所带来的经济红利之间的矛盾严重阻碍西南段的发展,因此亟需探索西南段的可持续发展路径。采用耦合协调度模型(CCDM)对2010—2019年“中脊带”西南段245个县的经济—社会—环境三系统协调发展情况、空间聚集特征进行了探讨。结果表明:“中脊带”西南段整体协调发展态势向好,然而区域发展不平衡现象十分突出。热点主要集中于以成渝城市群为核心的东北部,该地区三大子系统同步发展现象突出;冷点则主要分布在西南部少数民族聚居地区,区域内大多数县的经济与社会系统滞后于环境系统发展。此外,研究还发现不同的行政区划、生态本底、经济发展状况与协调发展水平的差异存在一定的联系。

关键词：胡焕庸线美丽中国中脊带耦合协调度西南地区发展策略

DEVELOPMENT OF EXPERIMENTAL METHODS FOR IMPACT TESTING BY COMBINING HOPKINSON PRESSURE BAR WITH OTHER TECHNIQUES

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2014年第4期27卷 331-344页

作者： Lili Wang Shisheng hu Liming Yang Zijian Sun jue Zhu huawei Lai Yuanyuan Ding Mechanics and Material Science Research Center Ningbo University Department of Modern Mechanics University of Science & Technology of China huafeng Faculty Ningbo Polytechnic Department of Municipal Engineering Zhejiang University of Water Resources and Electric Power

The split Hopkinson pressure bar（SHPB） technique and the wave propagation inverse analysis（WPIA） technique are both extensively used to experimentally investigate the impact behavior of materials, although neither of them alone provides a fully satisfactory analysis. In the present paper, attention is given to new experimental techniques by incorporating a damagemodified constitutive model into the SHPB technique and combining the Hopkinson pressure bar（HPB） technique with WPIA. First, to distinguish the response due to dynamic constitutive behavior and the response due to dynamic damage evolution, the SHPB method incorporating a damage-modified constitutive model is developed, including an explicit damage-modified Zhu–Wang–Tang model and an implicit damage-modified constitutive model. Second, when the SHPB results become invalid, a method of combining new Lagrange inverse analyses with the HPB technique is developed, including cases of the HPB arranged in front of a long specimen and behind the specimen. As examples of these new methods, typical results are given for nonlinear viscoelastic polymers and concretes considering damage evolution, a super-elastic Ti–Ni alloy with phase transformation and an aluminum foam with shock waves propagating within it.

关键词： Hopkinson pressure bar SHPB Lagrangian analysis high strain rate rate-dependent constitutive relation damage evolution

Competitive analysis of price online inventory problem with cost function

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2017年第4期32卷 493-502页

作者： HAN Shu-guang GUO Jiu-ling ZHANG Lu-ping hu jue-liang Department of Mathematics Zhejiang Sci-Tech University Hangzhou 310018 China

In this paper,a new price is given to the online decision maker at the beginning of each *** trader must decide how many items to purchase according to the current *** present three variants and an online algorithm based on cost *** competitive ratio of the online algorithm is given for each variant,which is a performance measure of an online *** importantly,we show that the online algorithm is optimal.

关键词： inventory problem price online cost function competitive analysis

First scanning Fabry–Perot interferometer developed in China

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2014年第5期59卷 563-570页

作者： Guoyuan hu Yong Ai Yange Zhang Hong Zhang jue Liu School of Electronic Information Wuhan University

A scanning Fabry–Perot interferometer(SFPI)was first developed and deployed at the Langfang near Space Environment Field Scientific Observation Station(39.38°N,116.65°E)of the National Space Science Center,*** instrument is designed to measure the mesospheric and thermospheric wind velocities using the atomic oxygen 557.7-nm and 630.0-nm *** from February 28 to March 3and February 28 to March 15 in 2011 were chosen for case study and mean value study,*** errors of the meridional and zonal winds are 6.5 and 7.5 m/s at 557.7-nm and at 630.0-nm,they are 7.1 and 6.6 m/s,*** the whole experiment,the instrument has performed in good condition and provided high-quality *** mean neutral wind data were consistent with that predicted by *** agreement has been found in between the SFPI and a neighbor Meridian Project Fabry–Perot interferometer(MP FPI),with a corresponding coefficient(r2)larger than 80%.In general,the scanning FPI meets the design goal,and it is a useful ground-based instrument for measuring mesospheric and thermospheric winds at middle latitudes and is able to provide high-quality data for future scientific studies.

关键词：中国科学院扫描法干涉仪地面仪器空间环境科学中心大气风速设计目标

Model Detection and Variable Selection for Varying Coefficient Models with Longitudinal Data

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2016年第3期32卷 331-350页

作者： san Ying FENG Yu Ping hu Liu Gen XUE School of Mathematics and Statistics Zhengzhou University College of Applied Sciences Beijing University of Technology

In this puper, we consider the problem of variabie selection and model detection in varying coefficient models with longitudinM data. We propose a combined penalization procedure to select the significant variables, detect the true structure of the model and estimate the unknown regression coefficients simultaneously. With appropriate selection of the tuning parameters, we show that the proposed procedure is consistent in both variable selection and the separation of varying and constant coefficients, and the penalized estimators have the oracle property. Finite sample performances of the proposed method are illustrated by some simulation studies and the real data analysis.

关键词： Combined penalization longitudinal data model detection variable selection oracle property varying coefficient model

Melting and floating processes of inorganic materials in molten steel:Visualization physical simulation and mathematical modelling

在线全文

学校读者我要写书评

暂无评论

China Foundry 2023年第2期20卷 89-98页

作者： Jin-hu Lai Sheng Yu Yang-jian Xu Dan-qing Jiang san-san Shuai Jiang Wang Zhong-ming Ren State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Shaoxing Institute of Technology Shanghai UniversityShaoxing 312000ZhejiangChina

It has been demonstrated that heat absorption method by using the inorganic material rod to cool the molten steel can significantly reduce the macrosegregation level of the large steel ***,owing to the opacity of the molten steel,the physical mechanism of the heat absorption method is not *** this work,a transparent hydraulic physical model with water and paraffin wax was built to simulate the melting and floating processes of inorganic materials in the molten steel.A mathematical simulation was also carried out to analyze the connection between the actual ingot and the physical *** show that it is feasible to simulate the molten steel and inorganic materials with water and paraffin *** the help of the physical model,the process of the melting of paraffin wax and its floating to the surface of water were clearly observed,during which the temperature of water at some characteristic positions in the mold was *** visualization findings demonstrate that the melting and floating processes of paraffin wax can help to bring the heat from the center of the mold to the top surface more quickly,which reduces the superheat and significantly accelerates the cooling rate of *** experimental results show that for the water with a certain superheat,the use of a larger mass of paraffin wax can accelerate the cooling of the water,but there is a risk of incomplete melting of the paraffin wax.A higher superheat of water will lead to a quicker melting rate for a given mass of paraffin wax,while a lower superheat leads to the incomplete melting of paraffin wax as well.

关键词： water and paraffin wax heat absorption method physical simulation superheat large steel ingot

Parallel machine covering with limited number of preemptions

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2014年第1期29卷 18-28页

作者： JIANG Yi-wei hu jue-liang WENG Ze-wei Zhu Yu-qing Department of Mathematics Zhejiang Sci-Tech University Department of Computer Science The University of Texas at Dallas

In this paper, we investigate the/-preemptive scheduling on parallel machines to maximize the minimum machine completion time, i.e., machine covering problem with limited number of preemptions. It is aimed to obtain the worst case ratio of the objective value of the optimal schedule with unlimited preemptions and that of the schedule allowed to be preempted at most i times. For the m identical machines case, we show the worst case ratio is 2m-i-1/m and we present a polynomial time algorithm which can guarantee the ratio for any 0 〈 i 〈2 m - 1. For the /-preemptive scheduling on two uniform machines case, we only need to consider the cases of i = 0 and i = 1. For both cases, we present two linear time algorithms and obtain the worst case ratios with respect to s, i.e., the ratio of the speeds of two machines.

关键词： 90B35 90C27 68Q25 i-preemptive scheduling machine covering approximation algorithm worst case ratio

附加质量法和FSI法用于弧形闸门动力特性分析的适用性

在线全文

学校读者我要写书评

暂无评论

中国港湾建设 2024年第1期44卷 1-6页

作者：胡友一王珏陆中伟郑赟河海大学机电工程学院江苏常州213022

为研究附加质量法和流固耦合界面(FSI)法用于弧形闸门动力特性分析的适用性,首先通过建立弧形闸门有限元模型,采用收敛性分析的方法研究了FSI法计算时流体长度的合理取值,保证了流体-弧形闸门系统自振频率的计算精度。其次,从弧形闸门... 详细信息

为研究附加质量法和流固耦合界面(FSI)法用于弧形闸门动力特性分析的适用性,首先通过建立弧形闸门有限元模型,采用收敛性分析的方法研究了FSI法计算时流体长度的合理取值,保证了流体-弧形闸门系统自振频率的计算精度。其次,从弧形闸门水头高度和刚度的角度出发,比较了采用附加质量法和FSI法对弧形闸门流固耦合效应的模拟结果,讨论了采用简化的附加质量法的适用性。最后,根据有限元计算的数值结果讨论了流固耦合效应对弧形闸门动力特性的影响。结果表明:(1)FSI法中流体长度取2倍水头高度可代替实际流体的无界性;(2)在水头较低且闸门刚度较大的情况下,采用附加质量法模拟流固耦合效应能在保证计算精度的基础上提高计算效率。随着水头增高,精度有所下降。此时,弧形闸门的自振频率明显降低,并且主要的变形由支臂转移到面板,有必要采用FSI法代替附加质量法来确保计算精度。

关键词：弧形闸门流固耦合附加质量法 FSI法自振频率