Effect of Al on the Microstructure and Mechanical Properties of Mg–Sn–Ca–Mn Wrought Alloy

Yun Feng,Yuanyuan Yang,Zongqi Xiao,Xianglong Meng,Guorong Zhou,Jinfeng Leng,Xinying Teng 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

Mg–Sn–Ca–Mn–xAl (x = 0,1.5 wt%) alloys with ultra-fine recrystallized grains were prepared by conventional extrusion(400 °C, 0.5 mm/s). Effects of aluminum (Al) on mechanical properties and microstructure of the Mg–1Sn–1Ca–0.5Mn(wt%) alloy were systematically investigated. By the addition of 1.5 wt% Al, the yield strength of the as-extruded alloysignificantly increased from 183 to 237 MPa. The as-cast alloys show a dendritic structure consists of α-Mg, (Mg, Al)2Ca,and CaMgSn phases. The as-extruded Mg–1Sn–1Ca–0.5Mn–1.5Al alloys exhibit a bimodal grain structure composed ofdynamic recrystallized (DRXed) fine grains and coarse unDRXed grains. Compared with Al free alloy, a lot of nano-scaleplanar Al2Caand rectangle shape Al8Mn5precipitated in the as-extruded alloy with 1.5 wt% Al. Meanwhile, the addition ofAl significantly strengthened alloys’ fiber texture with < 10–10 >//ED.

겨울철 자연(통풍)냉각과 상부 쿨링시스템을 이용한 남부 지역의 벼 고품질 유지를 위한 저온저장기술 개발

녕효봉,사공문,함택모,조성찬 忠北大學校 農業科學硏究所 2012 農業科學硏究 Vol.28 No.2

The purpose of this study is to investigate the storage characteristics of rough rice in a low temperature storage and dry bin using cooling system. The results were compared with the storage method of ambient temperature bin. The rough rice storage characteristics were evaluated from February to August 2010, using a storage and dry bin of 500 ton capacity. The results were as followings: Storage and dry bin using cooling system maintained the rice temperature less than 15oC over the storage period. The rough rice stored in the ambient temperature bin showed higher moisture content and lower germination rate than the rough rice stored in the bin using cooling system. The creaked rate and acid value of brown rice in the cooling bin storage increased less than the ambient temperature bin storage. The result indicates that storage bin using winter cold air and cooling system showed better maintaining germination of rice, less change of physiological activities and cracked kernel, and better maintaining of rice quality, comparing the ambient temperature bin

NUMERICAL MODELING OF VERTICAL-2D UNSTEADY FLOW AND SUSPENDED MATERIAL DISTRIBUTION

ZHANG XIAO-FENG,FENG XIAO-XIANG,CUI ZHAN-FENG 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Effect of the Oxygen Flux Ratio on the Structural and the Optical Properties of Silver-oxide Films Deposited by Using the Direct-current Reactive Magnetron Sputtering Method

Xiao-Yong Gao,Hong-Liang Feng,Zeng-Yuan Zhang,Jiao-Min Ma,Meng-Ke Zhao,Chao Chen,Jin-Hua Gu,Shi-E Yang,Yong-Sheng Chen,Jing-Xiao Lu 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.2

Using values of the oxygen flux ratio (OFR = [O2]/[Ar]) ranging from 0 to 0.5, authors deposited a series of silver-oxide (Ag_xO) films on glass substrates by direct-current reactive magnetron sputtering (DC sputtering) at a substrate temperature of 150 ℃. The effect of the OFR on the film’s structural and optical properties was systematically investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The Ag_xO films deposited clearly show an evolution of the film’s phase structure from the biphased (Ag + Ag_2O) structure to the biphased (AgO + Ag_2O) structure and then to the single-phased (Ag_2O) structure as value of the OFR increases. Accordingly, the film’s surface morphology, related to the film’s crystalline structure, clearly changes from a loose and porous surface structure to a compact surface structure and then to a pyramid-like surface structure with increasing value of the OFR. The novel porous structure may be attributed to the interruption of the silver’s growth course by the AgO on the film’s surface. Notably, a single-phased Ag_2O film is deposited by DC-sputtering at OFR = 0.5 due to the dual effects of thermal decomposition of the AgO phase and a combination reaction of AgO and Ag to Ag_2O. The oscillations both in the film’s reflectivity and transmissivity spectra are strengthened with increasing OFR, indicating an evolution from the metallic behavior of the biphased (Ag + Ag_2O) film to the dielectric behavior of the biphased (Ag_2O + AgO) film and the single-phased Ag2O film. The fitted optical absorption edges of the Ag_2O and the Ag_xO films deposited at values of the OFR of 0.5 and 0.33 are approximately 2.43 eV and 2.34 eV, respectively. The absorption edges are closely related to the direct interband transitions.

Prevalence and Age, Gender and Geographical Area Distribution of Esophageal Squamous Cell Carcinomas in North China from 1985 to 2006

Feng, Xiao-Shan,Yang, Yan-Tong,Gao, She-Gan,Ru, Yi,Wang, Gong-Ping,Zhou, Bo,Wang, Yu-Feng,Zhang, Peng-Fei,Li, Pu-Yu,Liu, Yong-Xuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

Objective: To establish the prevalence and distribution profile of esophageal squamous cell carcinomas (ESCCs) over a 22-yr period in North China. Methods: Using endoscopy for primary diagnosis and histological analysis for the further confirmation, a total of 74,854 ESCC patients aged 20-89 between January 1985 and December 2006 were investigated to analyze the epidemiological profile including prevalence rates, distribution of age-of-onset, gender and geographical area of ESCC in Luoyang, the highest incidence area of North China. Results: A total of 4092 cases of ESCC were finally diagnosed among 74,854 patients who had their first endoscopies. The prevalence among males was higher than that among females (p<0.01), resulting in an overall male:female OR of 1.2 (95%CI, 1.2-1.3). The prevalence in rural areas was higher than in urban areas (p<0.01), resulting in an overall rural:urban OR of 2.6 (95%CI, 2.4-2.9). The rural:urban ORs and the 95% CI increased continuously from 2.6, 2.3-3.0 to 2.7, 2.2-3.3, respectively, for 4 consecutive periods during the 22-yr study period. Moreover, the median age of onset among females was higher than that among males (p<0.01). For both sexes and in both areas, the prevalence rates declined and the median age of onset rose for 4 consecutive periods in the 22-yrs time frame (p<0.01). Conculsions: These data reveal the epidemiological profile of ESCC in the area of North China, and suggest that urban areas and rural people account for a growing proportion of the ESCC patients although the prevalence of ESCC significantly declined and the median age-of-onset postponed over the 22-yrs period. Moreover, the prevalence status of ESCC in rural areas also underlines the need for public health initiatives aimed at reducing risk factors of this fatal disease.

A case study of teacher appraisal in Shanghai, China: in relation to teacher professional development

Xiao Feng Zhang,Ho Ming Ng 서울대학교 교육연구소 2011 Asia Pacific Education Review Vol.12 No.4

Literature has confirmed that teacher appraisal can and should facilitate the professional development of teachers. In the past, teacher appraisal in China has been conducted mainly for administrative purposes; nowadays, it is increasingly being viewed as a means of teacher professional development. However, the way in which teacher appraisal affects teacher professional development has not been fully recognized. This case study, of a junior secondary school in Shanghai, China, explores how teacher appraisal has been carried out and how teachers and administrators have perceived it in relation to teacher professional development. The research findings identify the mechanism by which the teacher appraisal system in question facilitates professional development. The system creates pressure and extrinsic incentives that 'push and pull' teachers to improve, and supports their growth through guidance and directions. In addition, environmental factors such as school culture contribute to the positive impacts that teacher appraisal has on professional development.

A new algorithm of abstracting numeric image outline

Xiao-Feng Shang,Xue-Heng Tao,Xin Zhao,Jin-Shi Lu 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

A new algorithm based on iterative-dynamic algorithm and edge detection algorithm has been formulated in this paper. In the experiment, the binary image was first introduced by iterative-dynamic threshold algorithm, which had a good performance in restraining noise. Gauss filter was then applied to the binary image in order to eliminate some false edge pixels; statistic and differential coefficient methods were used for calculating the grads-in-image of scope and direction. The object edge was hereby detected and abstracted by using double threshold. Compared with traditional edge abstraction algorithm, the algorithm is advanced in solving the main problem that traditional edge abstraction was in the face of. By reason of using iterative-dynamic algorithm in the first step, it has perfect quality in restraining variety of disturbing factor, like random noise, optic distortion, light intensity and so on. Due to the application of statistic and differential coefficient, the perfect outcome was realized. The results of experiments have indicated that the edge of complex image can be precisely abstracted and the drawbacks of traditional edge detection algorithm can be thoroughly overcome by means of this method.

Tunable Multiwavelength Fiber Ring Lasers Based on an Opto-VLSI Processor

Feng Xiao,Alameh, Kamal,Yong Tak Lee IEEE 2011 IEEE photonics technology letters Vol.23 No.3

<P>We propose and experimentally demonstrate the principle of a tunable multiwavelength fiber ring laser based on the use of an opto-very-large-scale-integration (Opto-VLSI) processor in conjunction with an erbium-doped fiber amplifier and a semiconductor optical amplifier. Multiple wavelength channels within the gain range of the optical amplifiers can independently be generated, tuned and/or switched on/off, through applying appropriate phase holograms onto the Opto-VLSI processor. A tunable five-wavelength fiber ring laser of output power of around +6 dBm per channel and a sidemode suppression ratio (SMSR) greater than 30 dB is demonstrated. The tunable multiwavelength fiber lasers have excellent stability at room temperature.</P>

Vibrational Resonance in a Bistable System with Multiplicative and Additive Noise

Feng Guo,Xiao-Feng Cheng 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.6

The vibrational resonance (VR) phenomenon in a bias bistable system driven by a high-frequency (HF) signal and a low-frequency (LF) signal, as well as by multiplicative and additive white noises, is investigated. On the assumption that the frequency of the HF signal is much higher than that of the LF signal, using frequency-average on the HF signal, the Fokker-Planck equation for the averaged probability density is obtained. Under the adiabatic approximation, the expression of the signal-to-noise ratio (SNR) with respect to the LF signal is obtained. The SNR shows a VR behavior as a function of the amplitude and the frequency of the HF signal. In addition, the SNR varies non-monotonically with the intensities of the multiplicative and the additive noises, i.e., traditional stochastic resonance occurs. The influences of the system bias and the frequency of the LF signal on the SNR are also discussed.

Cloning and Characterization of A Full-Length cDNA of Chitinase in Brassica campestris ssp. chinensis

Xiao Feng Chen,Jing Yi zhang,Xilin Hou 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-