Deposition and evaluation of MoNx films deposited by magnetron sputtering

Yajun Ma,Shenghua Li,Yuansheng Jin,Guoshun Pan,Yucong Wang,Simon C. Tung 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10

Molybdenum Nitrided (MoNx) films were deposited by DC planar magnetron sputtering. Silicon wafers and real nitrided stainless steel piston rings are employed as substrates. 12 different combinations of nitrogen and argon partial pressure, from 1:7 to 7:1, were applied to deposit MoNx films. X-ray diffraction (XRD) was used to determine the phase structures of films. When nitrogen vs. argon partial pressure is 1:7, the film is mainly MO₂N phase. With increase of nitrogen partial pressure, MoN phase emerges, but MO₂N phase still exists. Composition analysis with atomic emission spectrometry (AES) also agreed with this. The films have very high nanohardness (max 2400Hv) and good adhesion to the substrates.

Ontology-Based Exchange of Product Data Semantics between CAD and CAE

Qinyi Ma,Yajun Wang,Yan Lv,Xin Jin,Maojun Zhou 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.12

The interoperation of various applications will need a representation that goes beyond the traditional geometry-based one, which is inadequate for capturing semantic information. This paper proposes an approach to annotate the CAD models based on ontology with the aim of making the design intent understood by computer and applied in engineering analysis, such as FEA. The paper presents the design domain ontology and FEA domain ontology, and applies feature technologies and the semantic Web to complete annotation. Semantic markup can embed the engineering semantic information such as product function, and design principle into the CAD geometry data through annotating, it makes the analyzers reuse design ideas quickly and conveniently to increase efficiency. The semantic file is proposed to support an exchange of product data semantics between CAD and CAE. The main idea of the approach is presented and key technologies are elaborated, including the creation of the FEA solution template, and the matching algorithm between semantic markup file and FEA template file. Finally, the feasibility and effectiveness of the approach is empirically validated by a case study.

Experimental and mechanism research on volatilization characteristics of HCl in desulfurization wastewater evaporation process using high temperature flue gas

Ma Shuangchen,Chai Jin,Wu Kai,Wan Zhongcheng,Xiang Yajun,Zhang Jingrui,Fan Zixuan 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.66 No.-

Due to the promulgation of “water pollution control action plan” in China, zero liquid discharge of desulfurization wastewater has become a new trend for water pollution control in power plants. The HCl volatilization in desulfurization wastewater evaporation process is the key problem that may influence the application of evaporation technology, so experiment was carried out in self-made experimental system. The effects of temperature, pH, Cl− concentration, total dissolved solids and main metal ions on HCl volatilization were explored. Results have shown that HCl volatilization increases respectively from 5.42% to 20.43% and 2.22% to 9.18% with the increasing temperature from 180 °C to 380 °C in two kinds of actual desulfurization wastewater evaporation process. When pH < 7, Cl− concentration is the main influencing factor on HCl volatilization; the higher Cl− concentration is, the higher HCl volatilization will be observed. While pH > 7, pH becomes the dominant factor, increasing pH will inhibit HCl volatilization; Mechanism of HCl volatilization was studied simultaneously by XRD and TGA. Gaseous HCl mainly comes from the combination of free H+ and Cl−, hydrolysis of Ca2+ and Mg2+ in liquid phase and hydrolysis of hydrate in high temperature solid phase; Ways to inhibit HCl volatilization in process were put forward according to the experimental results. The use of Ca(OH)2 to adjust the pH of desulfurization wastewater to 9.0–10.0 can inhibit HCl volatilization economically and efficiently. This study provides the key data for the application of flue gas evaporation technology under high temperature. The research results have important theoretical and practical values for the engineering practice of this technology.

Secure Transmission Scheme Based on the Artificial Noise in D2D-Enabled Full-Duplex Cellular Networks

( Chen Yajun ),( Yi Ming ),( Zhong Zhou ),( Ma Keming ),( Huang Kaizhi ),( Ji Xinsheng ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.10

In this paper, a secure transmission scheme based on the artificial noise is proposed for D2D communications underlaying the full-duplex cellular network, and a secure power allocation scheme to maximize the overall secrecy rate of both the cellular user and D2D transmitter node is presented. Firstly, the full-duplex base station transmits the artificial noise to guarantee the secure communications when it receives signals of cellular uplinks. Under this secure framework, it is found that improving the transmission power of the cellular user or the D2D transmitter node will degrade the secrecy rate of the other, although will improve itself secrecy rate obviously. Hence, a secure power allocation scheme to maximize the overall secrecy rate is presented subject to the security requirement of the cellular user. However, the original power optimization problem is non-convex. To efficiently solve it, we recast the original problem into a convex program problem by utilizing the proper relaxation and the successive convex approximation algorithm. Simulation results evaluate the effectiveness of the proposed scheme.

Developmental Effects of Dietary Nucleotides in Second-Generation Weaned Rats

Meihong Xu,Yi Ma,Linlin Xu,Yajun Xu,Yong Li 한국식품영양과학회 2013 Journal of medicinal food Vol.16 No.12

The aim of the present study was to evaluate dietary effects of dietary nucleotides (NTs) on developmental parameters in second-generation Sprague-Dawley rats. Experimental design was set up as six groups, including one control and five nucleotide administered groups, doses ranged from 0.01% to 1.28% nucleotides. First-generation (F0) rats were divided into two terms: (1) fed for 90-day study; (2) mated for offspring (F1). After weaning, each group of second-generation F1 rats was fed the control diet. Evaluating parameters were weight gain and food utilization ratios of rats, hematological and biochemical parameters, and organ pathology. The results showed that there was a greater weight gain and food utilization ratio in weaned rats (F0 and F1). Furthermore, weight gain and food utilization ratios were increased in the first 2 weeks of F1 male and the first week of F1 female rats. There were no significant changes in blood indicators of NT groups with the exception of decrease in aspartate aminotransferase and serum uric acid levels. Overall, it was demonstrated that NT supplements could promote the early growth and development at a 0.01% dose. Although NTs may have cumulative reproductive effects, they were safe even at a high-dose supplementation. Additionally, NT supplementation could promote restoration and optimize liver function.

Ultrashort Echo Time MRI (UTE-MRI) Quantifications of Cortical Bone Varied Significantly at Body Temperature Compared with Room Temperature

Jerban, Saeed,Szeverenyi, Nikolaus,Ma, Yajun,Guo, Tan,Namiranian, Behnam,To, Sarah,Jang, Hyungseok,Chang, Eric Y.,Du, Jiang Korean Society of Magnetic Resonance in Medicine 2019 Investigative Magnetic Resonance Imaging Vol.23 No.3

Purpose: To investigate the temperature-based differences of cortical bone ultrashort echo time MRI (UTE-MRI) biomarkers between body and room temperatures. Investigations of ex vivo UTE-MRI techniques were performed mostly at room temperature however, it is noted that the MRI properties of cortical bone may differ in vivo due to the higher temperature which exists as a condition in the live body. Materials and Methods: Cortical bone specimens from fourteen donors ($63{\pm}21$ years old, 6 females and 8 males) were scanned on a 3T clinical scanner at body and room temperatures to perform T1, $T2^*$, inversion recovery UTE (IR-UTE) $T2^*$ measurements, and two-pool magnetization transfer (MT) modeling. Results: Single-component $T2^*$, $IR-T2^*$, short and long component $T2^*s$ from bi-component analysis, and T1 showed significantly higher values while the noted macromolecular fraction (MMF) from MT modeling showed significantly lower values at body temperature, as compared with room temperature. However, it is noted that the short component fraction (Frac1) showed higher values at body temperature. Conclusion: This study highlights the need for careful consideration of the temperature effects on MRI measurements, before extending a conclusion from ex vivo studies on cortical bone specimens to clinical in vivo studies. It is noted that the increased relaxation times at higher temperature was most likely due to an increased molecular motion. The T1 increase for the studied human bone specimens was noted as being significantly higher than the previously reported values for bovine cortical bone. The prevailing discipline notes that the increased relaxation times of the bound water likely resulted in a lower signal loss during data acquisition, which led to the incidence of a higher Frac1 at body temperature.

Ultrashort Echo Time MRI (UTE-MRI) Quantifications of Cortical Bone Varied Significantly at Body Temperature Compared with Room Temperature

Saeed Jerban,,Nikolaus Szeverenyi,Yajun Ma,Tan Guo,Behnam Namiranian,Sarah To,장형석,Eric Y. Chang,Jiang Du 대한자기공명의과학회 2019 Investigative Magnetic Resonance Imaging Vol.23 No.3

Purpose: To investigate the temperature-based differences of cortical bone ultrashort echo time MRI (UTE-MRI) biomarkers between body and room temperatures. Investigations of ex vivo UTE-MRI techniques were performed mostly at room temperature however, it is noted that the MRI properties of cortical bone may differ in vivo due to the higher temperature which exists as a condition in the live body. Materials and Methods: Cortical bone specimens from fourteen donors (63 ± 21 years old, 6 females and 8 males) were scanned on a 3T clinical scanner at body and room temperatures to perform T1, T2*, inversion recovery UTE (IR-UTE) T2* measurements, and two-pool magnetization transfer (MT) modeling. Results: Single-component T2*, IR-T2*, short and long component T2*s from bicomponent analysis, and T1 showed significantly higher values while the noted macromolecular fraction (MMF) from MT modeling showed significantly lower values at body temperature, as compared with room temperature. However, it is noted that the short component fraction (Frac1) showed higher values at body temperature. Conclusion: This study highlights the need for careful consideration of the temperature effects on MRI measurements, before extending a conclusion from ex vivo studies on cortical bone specimens to clinical in vivo studies. It is noted that the increased relaxation times at higher temperature was most likely due to an increased molecular motion. The T1 increase for the studied human bone specimens was noted as being significantly higher than the previously reported values for bovine cortical bone. The prevailing discipline notes that the increased relaxation times of the bound water likely resulted in a lower signal loss during data acquisition, which led to the incidence of a higher Frac1 at body temperature.

Characterization and identification of OsFTL8 gene in rice

Zhang Siju,Jin Yajun,Hao Hongjiao,Liang Shanshan,Ma Xuan,Luan Weijiang 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.6

The rice genome contains 13 Flowering Locus T-Like (FT-Like) genes, among which, OsFTL2/Hd3a and OsFTL3/RFT1 are characterized as forigen-encoding genes, promoting rice fowering under short-day and long-day conditions, respectively. However, the functions of the other FT-Like members are still unknown in rice. In this study, we characterized and identifed a member of FT-Like family, OsFTL8 gene. The investigation of photoperiodic expression pattern showed that OsFTL8 transcription was mainly induced under short-day conditions. The qRT-PCR and GUS staining assays indicated that OsFTL8 was broadly expressed in various organs, including stems, leaves and panicles. OsFTL8 overexpression transgenic lines and its knockout mutants displayed no obvious change in their heading date, compared with the wild type. However, the pollen viability and seed setting rate were decreased in the overexpression transgenic lines. OsFTL8 localizes in both nucleus and cytoplasm. And we found that OsFTL8 does not interact with OsFD1 in vivo, suggesting that OsFTL8 may not be the component of forigen activation complex (FAC). In summary, our results indicate that OsFTL8 is associated with pollen viability and not involved in regulating rice fowering time, implying functional divergence of FT-Like members.