http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Preparation of PEO ceramic coating on Ti alloy and its high temperature oxidation resistance
Yongjun Xu,Zhongping Yao,Fangzhou Jia,Yunlong Wang,Zhaohua Jiang,Haitao Bu 한국물리학회 2010 Current Applied Physics Vol.10 No.2
Ceramic coatings were prepared in Na2SiO3–Na2CO3–NaOH system by pulsed bi-polar plasma electrolytic oxidation on Ti–6Al–4V alloy. The phase composition, structure and the elemental distribution of the coatings were studied by XRD, SEM and energy dispersive spectroscopy, respectively. The thermal shock resistance of the coated samples at 850 ℃ was evaluated by the thermal shock tests. The high temperature oxidation resistance of the coating samples at 500 ℃ was investigated. The results showed that the coating was mainly composed of rutile- and anatase TiO2, Increasing the concentration of Na2SiO3, TiO2content decreased gradually while the thickness of the coating increased. There were a large amount of micro pores and sintered particles on the surface of the coatings. Increasing concentration of Na2SiO3, the sintered particles on the surface turned large, and the Si content increased while the Ti content decreased gradually. When the concentration of Na2SiO3 was 15 g/L, the thermal shock resistance of the coatings was better than that of the coatings that prepared under other Na2SiO3 concentrations. The coating samples prepared under the optimized technique process based on the thermal shock tests improved the high temperature oxidation resistance at 500 ℃ greatly, whether considering the isothermal oxidation or the cyclic oxidation.
A Novel Preserving Client Privacy and Designate Verifier Auditing Scheme for Cloud Storage
Jiang Xu,Wenliang Chen,Sai Ji,Yongjun Ren,Jin Wang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.1
Cloud storage is now an important development trend in information technology. To ensure the integrity of data storage in cloud storing, researchers have present some proof of storage schemes. In some cases, the ability to check data possession is delegated by data owners. Hence, the delegable provable data possession and proxy provable data possession are proposed. However the schemes are not secure since the proxy or designated verifier stores some delegation information in cloud storage servers. In this paper, we propose PC-DV POS scheme, which can preserve clients’ privacy and designate a verifier by the client signed the data blocks. In particular, we utilize group signatures and key exchange to construct homomorphic authenticators, so that only the designated verifier is able to check the integrity of shared data for users without retrieving the entire data, and cannot reveal the identities of signers on all blocks in shared data.
Analytical model for the basement wall horizontally supported by flexible floor diaphragms
Yongjun Lin,Xianzhao Zhang,Kaiqi Liu,Wenqiang Xu 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.79 No.5
Subterranean floors are treated as the rigid lateral support in the current practice for the basement wall design. The structural performance of the basement wall will be influenced by the floor openings, which are inevitable to satisfy building functional requirements. An analytical model for the basement wall being presented is able to analyze the effect of such opening quantitatively. The magnitude of the horizontal support stiffness is determined based on deformation analysis of the diaphragm opening area. Idealized models of the basement wall are continuous beams with various degrees of indeterminacy. The force method is used to deduce the functions for internal forces acting towards the basement wall. The proposed analytical model is verified with results derived by finite element analyses through consideration of various factors, including various numbers of stories, combinations of beam-slab sections, and percentages of floor opening dimensions. The maximum deviations on critical design sections for all prototype basement structures are less than 15.99%. Comparisons with conventional rigid support models are also performed, providing an estimation of the effect of the opening on the mechanical behavior of the basement wall.
Shi Lingling,Xu Yongjun,Li Kang,Yao Zhongping,Wu Songquan 한국물리학회 2010 Current Applied Physics Vol.10 No.3
In order to improve the corrosion resistance of ceramic coatings formed on Mg–5mass%Li substrate by micro-arc oxidation (MAO) method, two kinds of additives (Na2B4O7 and EDTA) were doped in Na2SiO3–Na3PO4 solution system. The surface and cross-section morphology feature, phase composition and elemental composition were examined by SEM, XRD and EDX, respectively. Corrosion resistance of ceramic coating was tested by electrochemical methods. It was revealed that all coatings were composed of MgO and Mg2SiO4, and had porous surface structure. Doping of additives had little effect on the elemental composition, while it influenced the morphological feature of the coating. The results of electrochemical tests showed that the coatings prepared in the solutions with additive had good corrosion resistance. The addition of EDTA to the solution made coatings thinner and more uniform which resulted in better general corrosion resistance. The addition of Na2B4O7 to the solution made coatings much thicker and compacter, which improved the pitting corrosion resistance.
An Integrated Artificial Neural Network-based Precipitation Revision Model
( Tao Li ),( Wenduo Xu ),( Li Na Wang ),( Ningpeng Li ),( Yongjun Ren ),( Jinyue Xia ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.5
Precipitation prediction during flood season has been a key task of climate prediction for a long time. This type of prediction is linked with the national economy and people's livelihood, and is also one of the difficult problems in climatology. At present, there are some precipitation forecast models for the flood season, but there are also some deviations from these models, which makes it difficult to forecast accurately. In this paper, based on the measured precipitation data from the flood season from 1993 to 2019 and the precipitation return data of CWRF, ANN cycle modeling and a weighted integration method is used to correct the CWRF used in today’s operational systems. The MAE and TCC of the precipitation forecast in the flood season are used to check the prediction performance of the proposed algorithm model. The results demonstrate a good correction effect for the proposed algorithm. In particular, the MAE error of the new algorithm is reduced by about 50%, while the time correlation TCC is improved by about 40%. Therefore, both the generalization of the correction results and the prediction performance are improved.
Simin Li,Yuanfang Luo,Chen Yongjun,Tiwen Xu,Bangchao Zhong,Zhixin Jia,Demin Jia 한국섬유공학회 2019 Fibers and polymers Vol.20 No.8
To simultaneously improve processing performances of rubber composites and avoid additive-blooming problem,the concept of “supported rubber additives” was introduced and reactive processing additive oleic acid (OA) was chemicallyimmobilized onto the surface of silica to obtain silica-supported processing additive (SiO2-s-OA). In this study, SiO2-s-OAwas uniformly dispersed into styrene-butadiene rubber (SBR) and gained improved interfacial interaction with rubber matrixdue to its good compatibility and the reaction during vulcanization. Consequently, SBR compounds with SiO2-s-OApossessed lower vulcanizing torque and viscosity under high shear frequency, showing improved processing performance. Moreover, the tensile modulus and strength of SBR/SiO2-s-OA could be enhanced by as much as 88.40 % and 11.44 %compared to SBR/SiO2, respectively, which is also higher than SBR/m-SiO2. Taken together, these results indicate that thismethod for the surface treatment of silica to prepare supported rubber additives may be extended for other nanofillers andrubber additives, which has better processing performance and improved mechanical property simultaneously.