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11.
12.
Synthesis and properties of polystyrene/graphite nanocomposites 总被引:3,自引:0,他引:3
In this paper, graphite/polystyrene nanocomposite is synthesized by in situ polymerization of styrene in a tetrahydrofuran (THF) solution system of potassium (K)-THF-graphite intercalation compound (GIC). K-THF-GIC has proved to initiate polymerization of styrene by the anionic mechanism. Due to the interfacial interaction between the graphite nanolayers and the polymer, the composites exhibit higher glass transition temperature and higher thermal stability when compared to polystyrene. The percolation threshold in the conductivity of the composites is lesser than 8.2 wt% and the dielectric constant can reach as high as 136. 相似文献
13.
通过对集成基础结构中应用服务器的功能需求分析,采用面向对象方法、矩阵理论和Petri网技术研究了应用服务器系统的实现策略,并依据智能工程理论给出了应用服务器的系统结构。 相似文献
14.
贮存稳定的聚氨酯干式复合胶粘剂的研究 总被引:4,自引:0,他引:4
研制了一种具有高固含量、低粘度的干式复合用双组分聚氨酯胶粘剂,考察了聚酯多元醇,扩链剂丙三醇/乙二醇(摩尔比)、NCO/OH(摩尔比),双组分胶配比以及缓凝剂等因素对该胶粘剂性能的影响,并用红外光谱对胶的固化过程进行了表征。结果表明,该胶粘剂具有较高的粘接强度,优良的低温流动性和贮存稳定性。 相似文献
15.
A numerical methodology coupling Navier-Stokes equations and structural modal equations for predicting 3-D transonic wing flutter is developed in this paper. A dual-time step implicit unfactored Gauss-Seidel iteration with the Roe scheme is employed for the flow solver. A modal approach is used for the structural response. The flow and structural solvers are fully coupled via successive iterations within each physical time step. The mesh-deformation strategy is described. The accuracy of the modal approach is validated with ANSYS. The results indicate that the first five modes are sufficient to accurately model the wing-structure response for the studied case of this paper. The computed flutter boundary of AGARD wing 445.6 at free stream Mach numbers ranging from 0.499 to 1.141 agrees well with the experiment. 相似文献
16.
本文用ASAP2000吸附仪测定了吸附性能优异的沥青基高比表面积新型活性碳(PHAC)的BET比表面积、用BJH和DRS法分析了其孔隙结构参数,用XPS测定了PHAC的表面元素组成及含氧官能团,对PHAC的表面形态结构进行了SEM和TEM观察。研究表明:PHAC具有高度发达且均匀的微孔结构,其表面含有一定量的C-O-C、C-OH、C=O、O=C-O等多种类型的含氧官能团。 相似文献
17.
Wu Li Yann-Hang Lee Wei-Tek Tsai Jingjing Xu Young-Sung Son Jun-Hee Park Kyung-Duk Moon 《Service Oriented Computing and Applications》2012,6(1):65-79
A smart home usually has a variety of devices or home appliance, instead of designing software for a specific home, this paper
proposes a service-oriented framework with a set of ontology systems to support service and device publishing, discovery of
devices and their services, composition of control software using existing control services that wrap devices, deployment,
and execution of the composed service in an computing environment, monitoring the execution, and recovery from device failure.
The ontology systems specify semantic information about devices, services, and workflows used in various smart home, and users
can compose and recompose services for their specific needs. New devices, workflows, and services can be added into ontology.
Most of the steps in this process can be automated including code generation. For example, service composition will be carried
out in three steps: abstract workflow design, function construction, and device discovery, and different codes can be generated
for different computing platforms such as Java and Open Services Gateway initiative environments. In this way, a variety of
smart home can be constructed rapidly using the framework by discovery and composition using existing services and workflows.
This paper illustrates this framework using a media control example to illustrate the ontology, discovery, composition, deployment,
execution, monitoring, and recovery. 相似文献
18.
陈菁菁 《电脑编程技巧与维护》2012,(6):29-30,34
随着社会信息化的发展,信息素养日益成为信息社会公民素养不可或缺的组成部分,对课堂管理提出了更高的要求。信息技术课程具有独特的学科特点以及特有的教学环境,给课堂的管理带来了困难和不便。从建立课堂常规、固定上机位置、设置门禁门槛等方面,探索了信息技术课堂有效管理的方法。 相似文献
19.
运用线性滑动平均、Mann-Kendall非参数趋势检验、Sen′s坡度、小波分析及多元线性回归方法,选取济南市24个降水站点45年(1972—2016年)逐日降水资料,分析了济南市在年和季节尺度上的降水特征以及降水量的决定性影响因素。结果表明:年降水量以8.23mm/(10a)的速率增加,且呈现出丰枯交替的变化周期,最大主周期为10a;降水量主要集中在夏季,占全年降水量的64.5%,冬季降水占比最小,占全年降水量的3.4%,春、夏和冬季降水具有不显著增加趋势,秋季的降水量具有不显著下降趋势;降水量的年际、春夏季变化主要受降水强度变化的影响;秋冬季变化则主要受降水频率变化的影响。 相似文献
20.
Guang Sun Jingjing Lin Chen Yang Xiangyang Yin Ziyu Li Peng Guo Junqi Sun Xiaoping Fan Bin Pan 《计算机系统科学与工程》2021,36(3):509-520
Forecasting stock prices using deep learning models suffers from problems such as low accuracy, slow convergence, and complex network structures. This study developed an echo state network (ESN) model to mitigate such problems. We compared our ESN with a long short-term memory (LSTM) network by forecasting the stock data of Kweichow Moutai, a leading enterprise in China’s liquor industry. By analyzing data for 120, 240, and 300 days, we generated forecast data for the next 40, 80, and 100 days, respectively, using both ESN and LSTM. In terms of accuracy, ESN had the unique advantage of capturing nonlinear data. Mean absolute error (MAE) was used to present the accuracy results. The MAEs of the data forecast by ESN were 0.024, 0.024, and 0.025, which were, respectively, 0.065, 0.007, and 0.009 less than those of LSTM. In terms of convergence, ESN has a reservoir state-space structure, which makes it perform faster than other models. Root-mean-square error (RMSE) was used to present the convergence time. In our experiment, the RMSEs of ESN were 0.22, 0.27, and 0.26, which were, respectively, 0.08, 0.01, and 0.12 less than those of LSTM. In terms of network structure, ESN consists only of input, reservoir, and output spaces, making it a much simpler model than the others. The proposed ESN was found to be an effective model that, compared to others, converges faster, forecasts more accurately, and builds time-series analyses more easily. 相似文献