Raspberry-Like Nanocomposite Microsphere via Double In situ Miniemulsion Polymerization Using Interfacial Redox Initiator System

Beibei Yang,Jianan Zhang,Jizhi Lin,Bo Wu,Qing Liu,Wenlong Yang,Mingyuan Wu,Qingyun Wu,Jianjun Yang 한국고분자학회 2013 Macromolecular Research Vol.21 No.2

Query and Analysis of Data on Electric Consumption Based on Hadoop

Jianjun Zhou,Yi Wu 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.2

Traditional data management is usually based on relational databases, which are capable of managing small amounts of data. But relational databases have some difficulty in inquiry, management, and analysis of large amounts of data and magnanimity data. The method of effective management of magnanimity data is a problem deserving of study. In this paper, traditional relational databases are moved to Hadoop, in order to implement query and analysis on Hadoop. This paper changes the amount of data record and number of nodes in clusters, and records the query time in different conditions. Advantages and disadvantages of query on Hadoop can be analyzed by comparing the statistics with the query time on relational database Oracle. The factors affecting the time of query on Hadoop can be found by analysis. Furthermore, the result is also a reference material of future research and data managements on cloud platforms.

Influence of tip clearance on pressure fluctuations in an axial flow pump

Jianjun Feng,Xingqi Luo,Pengcheng Guo,Guangkuan Wu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

Rotor-stator interaction in axial pumps can produce pressure fluctuations and further vibrations even damage to the pump system in some extreme case. In this paper, the influence of tip clearance on pressure fluctuations in an axial flow water pump has been investigated by numerical method. Three-dimensional unsteady flow in the axial flow water pump has been simulated with different tip clearances between the impeller blade tip and the casing wall. In addition to monitoring pressure fluctuations at some typical points, a new method based on pressure statistics was proposed to determine pressure fluctuations at all grid nodes inside the whole pump. The comparison shows that the existence of impeller tip clearance magnifies the pressure fluctuations in the impeller region, from the hub to shroud. However, the effect on pressure fluctuation in the diffuser region is not evident. Furthermore, the tip clearance vortex has also been examined under different tip clearances.

Design of Electric Energy Acquisition System on Hadoop

Yi Wu,Jianjun Zhou 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.5

The big data set in Energy Acquisition System needs to acquire massive electric energy data and dynamic information online, and finishes processing in scheduled time. This requires a higher demand on massive data storage and data processing. In order to achieve these massive electric energy data efficiently, this article based on the data gathering system and storage structure of Hadoop technique, and tested electric energy mensuration log data set of a city as an example, the result shows that the bigger of the sets group, the better effect would be achieved, which effectively avoid the latency problem of big data set information processing respond.

Research Progress of Stream Data Query in Network Space

Yi Wu,Jianjun Zhou 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.5

In recent years, there has been widespread concern about the problems of stream data query both academic and industrial communities. The problems obtained some results. At the same time, big data stream brings great benefits for information society. Information query about stream data form has also brought crucial challenges. However, it is seldom about the research of big data stream query in network space. This paper analyzes the characteristics of stream data query in massive data, discusses the challenges and research issues of data stream for big data query. Finally the works for the data stream query are surveyed.

Fabrication of TiO₂ Microrod with Desired Shapes from Rod-like Titanium Glycolate

Han, Jianjun,Zhang, Hua,Li, Yuanzhi,Zhao, Xiujian,Chen, Hong,Wu, Zhongkui,Kim, Sun-Jae,Park, Kyeong Soon Chemical Society of Japan 2007 Chemistry letters Vol.36 No.11

<P>Rod-like titanium glycolate was prepared by poly-condensation of TiCl<SUB>4</SUB>, ethylene glycol, and water. Focusing electronic beam on one side of a titanium glycolate microrod led to bending of the micro-rod at the irradiation part. Calcination of the polymer results in formation of rod-like titania. By controlling irradiation time and changing focus position of electronic beam, we realized controllable processing of titania microrod with desired shapes, which may be find application in nano or microdevices.</P>

Study on the Embedded SPC System Bused on LAN

Yin, Jianjun,Yu, Zhonghua,Wu, Zhaotong The Korean Society for Quality Management 2003 The Asian Journal on Quality Vol.4 No.1

Statistical Process Control (SPC) is recognized as one of the most important tool of quality control (QC), and is one research focus in order to implement SPC quickly and effectively using computer technology and network environments. This paper proposes the principle and topology of embedded SPC based on the Internet/lntranet, emphatically discusses the embedded data sampling block, embedded network interface and SPC strategy. An example of application is given.

A numerical method for estimating the elastic modulus of recycled concrete

Xinzhu Zhou,Jianjun Zheng,Ting Chen,Jian Zhang,Chuanyang Wang,Jiefeng Wu 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.3

This paper aims at presenting a numerical method for estimating the elastic modulus of recycled concrete with crushed aggregates. In the method, polygonal aggregates following a given sieve curve are generated, and placed into a square simulation element with the aid of the periodic boundary condition and the overlap criterion of two polygonal aggregates. The mesostructure of recycled concrete is reconstructed by embedding an old interfacial transition zone (ITZ) layer inside each recycled aggregate and by coating all the aggregates with a new ITZ layer. The square simulation element is discretized into a regular grid and a representative point is selected from each sub-element. The iterative method is combined with the fast Fourier transform to evaluate the elastic modulus of recycled concrete. After the validity of the numerical method is verified with experimental results, a sensitivity analysis is conducted to evaluate the effects of key factors on the elastic modulus of recycled concrete. Numerical results show that the elastic modulus of recycled concrete increases with the increase of the total aggregate content and the elastic moduli of old and new ITZ but decreases with increasing the replacement ratio of recycled aggregate and the thicknesses of old and new ITZ. It is also shown that, for a replacement ratio of recycled aggregate smaller than 0.3, the elastic modulus of recycled concrete is reduced by no more than 10%.

Properties and Morphology of Interpenetrating Polymer Networks Based on Poly(urethane-imide) and Epoxy Resin

Jiangxuan Song,Gang Wu,Jianjun Shi,Yun Ding,Guangxin Chen,Qifang Li 한국고분자학회 2010 Macromolecular Research Vol.18 No.10

Incorporating elastic polyurethane in epoxy resin (EP) can enhance the physico-chemical properties but deteriorate the thermal stability. Poly(urethane-imide) (PUI) with a high reactive function group (-NCO), which combines the advantages of polyurethane and polyimide, was synthesized to simultaneously improve the toughness and thermal stability of epoxy resin. EP/PUI composites were prepared based on epoxy resin and poly(urethaneimide)with 4,4-diaminodiphenylmethane as the curing agent using a simultaneous polymerization method. FTIR analysis confirmed the formation of EP-g-PUI interpenetrating polymer networks via a reaction between -NCO of poly(urethane-imide) and -OH of epoxy resin. The thermal stability and mechanical properties were examined by thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and stress-tensile method, respectively. Corresponding to the pure epoxy resin, which has three stage thermal decomposition, the resulting PUI/EP composite exhibits only one stage and has a much higher initial decomposition temperature (323.8 oC) than that (189.8 oC)of the epoxy resin. Moreover, the EP/PUI composite has a higher glass transition temperature, tensile strength and breaking elongation when 30 phr PUI was added. With increasing PUI content to 70 phr, the breaking elongation was 213 times higher than that of the neat epoxy resin. The morphology of these composites was also investigated further by scanning electronic microscopy (SEM) and transmission electron microscopy (TEM). The results showed that a grafted interpenetrating polymer network was formed.

Influence of pump start-up mode on the stability of mixed-flow pumps

Zhenbo Tang,Guojun Zhu,Jianjun Feng,Yajun Wu,Kai Liu,Qiang Lu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.6

To analyse the influence of the start-up mode on the stability of the mixed-flow pump, start-up experiments are performed. And the external characteristic parameters, pressure fluctuation and shaft vibration data are collected by a multi-channel synchronous signal acquisition system during start-up. These data are analyzed by the time-frequency analysis method and wavelet partial coherence analysis method. Results reveal a positive correlation between the impeller angular acceleration and the time change rate of external characteristic parameters. During the start-up process, the variation law of the external characteristic parameters similar with the law of impeller rotating speed rise. The amplitude of the shaft vibration has a positive correlation with the start-up acceleration of the impeller. The influence of guide vane pressure fluctuations on the shaft vibrations is greater within 0~2 s after the start of the mixedflow pump. With the strart-up time extension, the partial coherence between the shaft vibration and the pressure fluctuations in guide vane is enhanced in low frequency band, which increases the risk of flow-induced vibration of the pump shaft.