Cui J.,Shijiazhuang University
Chemical Engineering Transactions | Year: 2016
In this paper, the effect of the polynaphthaene sulphonate type water reducer (PSWR) and new type polycarboxylate water reducer (PAWR) on the internal pore structure, internal defects and forces of resistance to external environmental of concrete are fully compared and analyzed. The effect of PAWR on improving the durability of concrete was revealed. The test result showed that compared with PSWR, PAWR can improve the pore structure and pore size distribution of concrete grout, improve the density of concrete, reduce the adiabatic temperature rise of concrete, optimize the hydration heat curve of cement, reduce the shrinkage and deformation of concrete, improve concrete anti-cracking performance and volume stability, to reduce the internal defects of concrete; at the same time, but also to improve the ability of the concrete, including anti-carbonation, frost resistance, chloride ion erosion resistance and steel protection in different degree, as well as to enhance the resistance of concrete to the external environment, thereby greatly improving the durability of concrete. Copyright © 2016, AIDIC Servizi S.r.l.
Zhang Z.,Shijiazhuang University |
Qian J.,Chongqing University
Construction and Building Materials | Year: 2017
Compared with the added gypsum, protogenetic anhydrite is the anhydrite in clinker and cement admixture. And using protogenetic anhydrite as the setting retarder instead of added gypsum to make cement could be an effective way to make full use of clinker and wastes with high sulphur content. However, the high temperature sensitivity of solubility property of protogenetic anhydrite may result in unhydrated anhydrite exist in cement paste under high curing temperature at early age, and that may make a bad influence on the properties of cement. This work investigated the effects of protogenetic anhydrite on the long-term strength, volume stability and hydration products of cement paste under different curing temperature. It is shown that higher curing temperature caused the greater value of optimum content of protogenetic anhydrite in cement, and protogenetic anhydrite could not make the bigger volume expansion and worse strength of cement than gypsum when the high curing temperature being used. But curing temperature caused the dissolution of protogenetic anhydrite change and influenced the concentration of sulfate ion in the pore solution of hardened cement paste. The results of XRD patterns showed that the risk of delayed ettringite formation in hardened cement paste cured at high temperature had been increased. The results will be helpful to understand the role of protogenetic anhydrite in cement, and further promote the use of clinker and wastes with high sulfate. © 2017
Shen Y.-M.,Shijiazhuang University |
Fang X.-Q.,Shijiazhuang University
Meccanica | Year: 2017
Based on the electro-elastic surface/interface theory, the size-dependent effective elastic properties of piezoelectric ceramic embedded with radially polarized nano-fibers are addressed, and the surface/interface effect is considered. Electroelastic equations for radially polarized piezoelectric ceramic are established. The analytical solutions of elastic displacement and electric potentials are exactly derived by separating variables method. The effective elastic modulus in the dilute limit is obtained by satisfying the boundary conditions with consideration of surface/interface energy. Analyses show that the effective elastic properties can be enhanced (or reduced) by adjusting the material properties of surface/interface. © 2017 Springer Science+Business Media Dordrecht
Liu Y.,Shijiazhuang University
Agro Food Industry Hi-Tech | Year: 2017
Power transformers serve as a bridge in the structure of electric power systems, and its stability and reliability are important links to the security of electric power systems, so we should study fault diagnosis of power transformers. In this paper, fault diagnosis of power transformers is investigated based on rough set theory and dominancebased rough set approach. The results show that the features of faults in power transformers can be extracted by using classical rough set theory, and fault criteria can be obtained. In this paper, five fault criteria are verified by using concrete examples and analyzed, and the results show that the fault criteria extracted based upon rough set theory can meet practical requirements. Moreover, dominance-based rough set approach is also employed to study the ordered maintenance of power transformers, and to establish an algorithm flow chart for ordered maintenance.
Li G.,Shijiazhuang University
Agro Food Industry Hi-Tech | Year: 2017
With the rapid development of modern society and the intensification of economic globalization, small and medium-sized enterprises (SMEs) have gradually become the core strength in China's economic development; SMEs are now playing an indispensable role in the perfection of economic structure, the enhancement of scientific and technological level, and the boost to productivity. However, the deficiencies in Chinese financial market, the inherent limitations of SMEs, and the unsolved problem of financing difficulties are imposing negative restraints on the healthy development of Chinese SMEs. Therefore, the commercial bank created the supply-chain finance, a novel financial service specially designed for SMEs. Supplychain finance can properly resolve the problem caused by the nonequivalent information between enterprises and commercial banks. Besides, it can effectively manage the financial difficulty resulted from insufficient mortgage. In this paper, the credit ratings of SMEs are analyzed from the perspective of supply-chain finance.
Han X.,Shijiazhuang University |
Sun M.,Shijiazhuang University
Modern Tunnelling Technology | Year: 2017
The section of soft surrounding rock around the Yanmenguan tunnel, which exhibits a straight alignment, has large overburdens and tectonic stresses, which is extremely challenging for deformation control during tunnel construction. Considering the characteristics of the squeezing surrounding rock around the Yanmenguan tunnel, a study was conducted with respect to measures for excavation deformation control. The Finite Differential Method (FLAC3D) was used to determine the rational length of the reserved core soil of the arced pilot tunnel during threebench seven-step construction, and the length of the system anchor bolt was optimized based on the scope and shape of the plastic zone of the tunnel surrounding rock. Furthermore, a study on the mechanical effect of the double-layer support and the construction time of the inner support was carried out: it concludes that it is best for construction of the inner support to take place at the same time as that of the inverted arch of the outer support. Comprehensive deformation control techniques, which include a 3~4 m long core soil, advanced support, an optimized system anchor bolt, a feet-locked anchor bolt and double-layer support (H175+I22a), are proposed based on numerical simulation and engineering practice that consider the squeezing surrounding rock around the Yanmenguan tunnel. © 2017, Editorial Office of "Modern Tunnelling Technology". All right reserved.
Xu M.,Shijiazhuang University
3D Research | Year: 2017
Abstract: Recently, chaotic image cipher using DNA sequence operation has been studied extensively. However, corresponding cryptanalysis is lacking, which impedes its further development. This paper cryptanalyzes a newly proposed chaotic image cipher based on DNA sequence operation. In this paper, we firstly analyze the security defects of the proposal. Then by applying chosen-plaintext attack, we show that all the secret parameters can be revealed. The effectiveness of the proposed chosen-plaintext attack is supported both by rigorous theoretical analysis and experimental results. Graphical Abstract: [Figure not available: see fulltext.] © 2017, 3D Research Center, Kwangwoon University and Springer-Verlag Berlin Heidelberg.
An B.,Shijiazhuang University
Agro Food Industry Hi-Tech | Year: 2017
Currently, the micro-blog is developing rapidly with increasing love and applications of users. Practices have proved that micro-blog can effectively promote the dissemination of information, therefore, ensuring the continuous uses the micro-blog of users is particularly important for the micro-blog service provider, and this is also a research topic in the field of industry and academia. In the study, the status quo of the research was surveyed; related theories were analyzed; on the basis of the theory, the impact of micro-blog users' information behavior factor model was built; with specific data, the feasibility and the advanced nature of the model were proved.
Chen C.,Shijiazhuang University
C e Ca | Year: 2017
Due to higher living standards, children's bicycle has become a must-buy item for families with children. As a result, more and more concern has been thrown on the user-friendly design of children's bicycle. Based on ergonomics, this paper explores the design in consideration of the safety and stability of children's bicycle and the impact on the fatigue of the rider. The author establishes a fatigue prediction model with the saddle coordinate position as the variable by regression analysis, thus obtaining the overall frame model of children's bicycle. Then, the author conducts simulation with ANSYS, modifies the frame in accordance with the stress distribution acquired from the simulation, and eventually improves the safety and comfort of children's bicycle.
Zhishuang L.,Shijiazhuang University
International Journal of Multimedia and Ubiquitous Engineering | Year: 2016
At present, artificial intelligence has become an important part of people’s life. Meanwhile, people’s health consciousness and demands for modern leisure sports have improved. Based on the technology of artificial intelligence, this paper is to study the evaluation of leisure sports majors’ innovation ability which stays in relatively low level but with great potential. After researching and analyzing the status of leisure sports majors’ innovation ability at home and abroad, the author defined the standard of gray rates, set gray evaluation index, analyzed the gray evaluation model and concluded that students in HeBei Institute of Physical Education have good innovation abilities. This paper which laid a foundation for studies of relevant theories and practices is a pioneering work for innovation ability evaluation. © 2016 SERSC.