Microstructure and Mechanical Properties of Cold Drawn Ti–Nb–Ta–Zr–O Wires for Orthodontic Applications

Wei‑dong Zhang,Junye Ren,Bin Liu,Yong Liu,Zhenggang Wu,Jingwen Qiu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.7

Ti–36Nb–2Ta–3Zr–0.35O (TNTZO) alloy is an excellent candidate for biomedical applications. In this study, a new methodcombining cold-swaging and cold-drawing was used to fabricate the TNTZO alloy wires with 0.3 mm diameter for orthodonticapplications. The microstructure and mechanical properties of cold-drawn and annealed TNTZO wires (referred toas TNTZO0.3and TNTZO0.3(HT), respectively) were investigated. The results show that the microstructure of cold drawnTNTZO0.3consists of main-sized elongated grains with 70 nm width. After annealing at 700 °C for 5 min, the microstructureof TNTZO0.3(HT) wires becomes equiaxial with a grain size of ~ 5 μm. The cold drawn TNTZO0.3wires exhibit improvedmechanical properties, higher tensile strength (about 1000 MPa) and similar elastic modulus (69 GPa), compared to annealedTNTZO0.3(HT) wires. Besides, TNTZO0.3has higher creep resistance and lower stress exponent (around 2), compared to Tiwires and TC4 wires with the same diameter. These results prove that TNTZO0.3wires have most of the ideal characteristicsof orthodontic wires.

Identification of candidate odorant‐degrading enzyme genes in the antennal transcriptome of Aphidius gifuensis

Kang Zhi‐Wei,Liu Fang‐Hua,Xu Yong‐Yu,Cheng Jia‐Hui,Lin Xiao‐Li,Jing Xiang‐Feng,Tian Hong‐Gang,Liu Tong‐Xian 한국곤충학회 2021 Entomological Research Vol.51 No.1

Odorant‐degrading enzymes (ODEs) have been found in insect antennae and play a critical role in signal chemical degradation once the message is conveyed. Significant progress has been made in characterizing ODEs in a variety of pests but very little is known in their natural enemies. We have carried out an antennae‐ and sex‐specific transcriptome of Aphidius gifuensis, a natural enemy of aphid, to identify the candidate ODEs. Based on the antennae‐ and sex‐specific transcriptome, a total of 100 putative ODEs were identified including one aldehyde oxidase (AOX), four alcohol dehydrogenases (ADs), eight UDP‐glucuronosyltransferases (UGTs), 45 cytochrome P450 (P450s), nine glutathione S‐transferases (GSTs) and 40 carboxylesterases (CCEs or CXEs). Additionally, we used RT‐qPCR to determine the expression profiles of these genes in tissues of both sexes. Based on the phylogenic analysis and tissue‐expression patterns, AgifEstE4, AgifCXE3, AgifCCE4, AgifCCE7, and AgifCCE18 were suggested as key ODEs in A. gifuensis. In addition, the female or male specifically enriched genes, such as AgifCCE17, AgifEstB1, AgifCYP18a1, AgifUGT2C2, were also considered to involve in the chemosensory processing in A. gifuensis. This study not only identified the candidate ODEs in A. gifuensis but also provided source for further exploration of the molecular mechanisms of chemical signal transductions in A. gifuensis, as well as other hymenopteran species.

W(110) 표면에 CO의 흡착

이경희,유위량,한현석,부진효,이순보,곽현태 성균관대학교 기초과학연구소 1998 論文集 Vol.49 No.-

The interaction of CO with W(110) surface was investigated through LEED, TDS, and photoelectron spectroscopy using synchrotron radiation under UHV condition. After CO saturation at RT, two desorption states, called α and β , were observed at about 400 and 1150 K in thermal desorption spectra, respectively. The kinetics of 3-CO followed the first order kinetics, indicating the existence of molecular CO on W(110) surface. This is contrary to the previous results. The O 1s BE(binding energy) of CO adsorbed on W(110) surface at room temperature was 529.9 eV. On the other hand, the O 1s BE of β-CO after heating to 900 K was different from that of oxygen adsorbed W(110) surface, suggesting a different adsorption state. According to the UP valence band spectra, we observed two peaks at near -10.7 eV (4σ) and -7.0 eV (5σ+1π), indicating the molecular adsorption of CO at room temperature. Furthermore we could see the 4σ peak at the various photon energy and elevated temperatures. Comparing the energy separation, Δ(4σ-1π) , between 4σ and 1π UP peaks of chemisorbed CO, we found that an increased separation reflects an decreased C-O bond strength. Therefore on the basis of TDS and photoelectron spectroscopy, we could suggest that β state of CO on W(110) may not be dissociated and has an adsorption geometry of lying-down mode.

Review of the Macrophya formosana group (Hymenoptera: Tenthredinidae) with descriptions of two new species

Meng-Meng LIU,Ze-Jian LI,Mei-Cai WEI 한국곤충학회 2019 Entomological Research Vol.49 No.5

The Macrophya formosana group is reviewed and six species are recognized from Europe and East Asia, among them two new species, M. brevispuralis Li, Liu & Wei sp. nov. and M. pseudoformosana Li, Liu &Wei sp. nov. from China, and four known species, M. crassula (Klug 1817), M. dolichogaster Wei & Ma, 1997, M. formosana Rohwer 1916 and M. liukiuana Takeuchi 1926. A key to all known species of the Macrophya formosana group is provided.

Overexpression of Capsular Polysaccharide Biosynthesis Protein in Lactobacillus plantarum P1 to Enhance Capsular Polysaccharide Production for Di-n-butyl Phthalate Adsorption

( Wei-bing Liu ),( Zhi-wei Lin ),( Ying Zhou ),( Bang-ce Ye ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.11

Exopolysaccharides (EPSs) such as capsular polysaccharide (CPS) are important bioactive carbohydrate compounds and are often used as bioenrichment agents and bioabsorbers to remove environmental pollutants like di-n-butyl phthalate (DBP). Among the EPS-producing bacteria, lactic acid bacteria (LAB) have gained the most attention. As generally recognized as safe (GRAS) microorganisms, LAB can produce EPSs having many different structures and no health risks. However, EPS production by LAB does not meet the needs of large-scale application on an industrial scale. Here, the capA gene (encoding CPS biosynthesis protein) was overexpressed in Lactobacillus plantarum P1 to improve the production of EPSs and further enhance the DBP adsorption capability. Compared with P1, the CPS production in capA overexpressed strain was increased by 11.3 mg/l, and the EPS thickness was increased from 0.0786 ± 0.0224 μm in P1 to 0.1160 ± 0.0480 μm in P1-capA. These increases caused the DBP adsorption ratio of P1-capA to be doubled. Overall, the findings in this study provide a safe method for the adsorption and removal of DBP.

Application of Adaptive Control on Carbon Fiber Diagonal Loom

Wei Liu,Shuo Wang,Fengdong Shi,Guowei Xu,Yi Cheng 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.3

In order to improve the control effect of the tension fluctuation, a single neuron adaptive control strategy based on quadratic performance index is proposed in this paper. The structure and the working principle of carbon fiber diagonal loom are studied which can be used for dynamic analysis and controller design. With the idea of optimal control, the parameters of the controller are adjusted by minimizing the sum of the square of the output error and the control increment. The simulation results based on TrueTime show that the strategy adopted in this paper compared with the traditional control strategy have the advantages of faster response time and smaller overshoot in networked control system.

Structural evaluation of an existing steel natatorium by FEM and dynamic measurement

Liu, Wei,Gao, Wei-Cheng,Sun, Yi,Yu, Yan-Lei Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.31 No.5

Based on numerical and experimental methods, a systematic structural evaluation of a steel natatorium in service was carried out in detail in this paper. Planning of inspection tasks was proposed firstly according to some national codes in China in order to obtain the economic and reliable results. The field visual inspections and static computation were conducted in turn under in-service environmental conditions. Further a three-dimensional finite element model was developed according to its factual geometry properties obtained from the field inspection. An analytical modal analysis was performed to provide the analytical modal properties. The field vibration tests on the natatorium were conducted and then two different system identification methods were used to obtain the dynamic characteristics of the natatorium. A good correlation was achieved in results obtained from the two system identification methods and the finite element method (FEM). The numerical and experimental results demonstrated that the main structure of the natatorium in its present status is safe and it still satisfies the demand of the national codes in China. But the roof system such as purlines and skeletons must be removed and rebuilt completely. Moreover the system identification results showed that field vibration test is sufficient to identify the reliable dynamic properties of the natatorium. The constructive suggestion on structural evaluation of the natatorium is that periodic assessment work must be maintained to ensure the natatorium's safety in the future.

Analysis of Shortage of China's Large-Scale Scientific Research Instruments Sharing

Liu, Wei,Yu, Suisheng 한중경제문화학회 2015 한중경제문화연구 Vol.5 No.-

Resource of large-scale scientific research instruments is an integral part of all kinds of scientific and technological resources, and plays a vital role in scientific and technological development. Even now, while increasing investment in science and technology, the inherent features of scarcity of scientific and technological resources and the efficiency of resource allocation are becoming more apparent. Limited technology resources to achieve effective and rational allocation has become an important issue facing the current technology investment. In this paper, we will explore China's large-scale scientific research instruments resources present in over-provisioning, shared inefficiencies and other issues, analyze the problems with the relevant theories, and offer some solutions.

Magnetic Nanoparticles with Core/shell Structures

Wei Zhong,Nujiang Tang,Wei Liu,Changqing Jin,Youwei Du 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

AN EMPIRICAL STUDY OF THE IMPACT OF DEBT SERVICE RATIO VOLATILITY ON DEBT SERVICE CAPACITY

Wei ping Liu People&Global Business Association 1997 Global Business and Finance Review Vol.2 No.2

Financial theoreticians have two diametrically opposed opinions on whether high volatility of indicators of a sovereign's debt service capacity (DSC) will affect its DSC or not. This paper summarizes these opinions into several hypotheses and examines them empirically. Data of debt service ratio and DSC of 105 countries between 1985-1992 were collected and volatility of each country's debt service ratios are computed. Stepwise logistics regression analyses and multivariate Chi-square tests a re conducted to test the relationship between the volatility of a country's DSC indicators and its DSC. Evidence has been found that generally DSC indicators' volatility is not a significant factor affecting a sovereign's DSC. This is probably because the major concern of a sovereign is the reputation of the nation so that the country can maintain a stable source of future international loans. When a borrowing country encounters financial shocks, it often adopts austerity policy and will default its loan only as a last resort. However, among medium-income countries, DSC indicators' volatility does affect a sovereign's DSC. This is probably because the governments in those countries are politically weak and cannot cutback imports to lower the nation's consumption level and make voters unhappy.