100KW DC Arc Plasma of CVD System for Low Cost Large Area Diamond Film Deposition

Lu, F.X.,Zhong, G.F.,Fu, Y.L.,Wang, J.J.,Tang, W.Z.,Li, G.H.,Lo, T.L.,Zhang, Y.G.,Zang, J.M.,Pan, C.H.,Tang, C.X.,Lu, Y.P. The Korean Ceramic Society 1996 The Korean journal of ceramics Vol.2 No.4

In the present paper, a new type of DC arc plasma torch is disclosed. The principles of the new magnetic and fluid dynamic controlled large orifice long discharge tunnel plasma torch is discussed. Two series of DC Plasma Jet diamond film deposition equipment have been developed. The 20kW Jet equipped with a $\Phi$70 mm orifice torch is capable of deposition diamond films at a growth rate as high as 40$\mu\textrm{m}$/h over a substrate area of $\Phi$65 mm. The 100kW high power Jet which is newly developed based on the experience of the low power model is equipped with a $\Phi$120 mm orifice torch, and is capable of depositing diamond films over a substrate area of $\Phi$110 mm at growth rate as high as 40 $\mu\textrm{m}$/h, and can be operated at gas recycling mode, which allows 95% of the gases be recycled. It is demonstrated that the new type DC plasma torch can be easily scaled up to even higher power Jet. It is estimated that even by the 100kW Jet, the cost for tool grade diamond films can be as low as less than $4/carat.

Coronary Computed Tomography Angiography-Derived Fractional Flow Reserve in Patients with Anomalous Origin of the Right Coronary Artery from the Left Coronary Sinus

Chun Xiang Tang,Meng Jie Lu,Joseph Uwe Schoepf,Christian Tesche,Maximilian Bauer,John Nance,Parkwood Griffith,Guang Ming Lu,Long Jiang Zhang 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.2

Objective: To examine the fractional flow reserve derived from computed tomographic angiography (CT-FFR) in patients with anomalous origin of the right coronary artery from the left coronary sinus (R-ACAOS) with an interarterial course, assess the relationship of CT-FFR with the anatomical features of interarterial R-ACAOS on coronary computed tomographic angiography (CCTA), and determine its clinical relevance. Materials and Methods: Ninety-four patients with interarterial R-ACAOS undergoing CCTA were retrospectively included. Anatomic features (proximal vessel morphology [oval or slit-like], take-off angle, take-off level [below or above the pulmonary valve], take-off type, intramural course, % proximal narrowing area, length of narrowing, minimum luminal area [MLA] at systole and diastole, and vessel compression index) on CCTA associated with CT-FFR ≤ 0.80 were analyzed. Receiver operating characteristic analysis was performed to describe the diagnostic performance of CT-FFR ≤ 0.80 in detecting interarterial R-ACAOS. Results: Significant differences were found in proximal vessel morphology, take-off level, intramural course, % proximal narrowing area, and MLA at diastole (all p < 0.05) between the normal and abnormal CT-FFR groups. Take-off level, intramural course, and slit-like ostium (all p < 0.05) predicted hemodynamic abnormality (CT-FFR ≤ 0.80) with accuracies of 0.69, 0.71, and 0.81, respectively. Patients with CT-FFR ≤ 0.80 had a higher prevalence of typical angina (29.4% vs. 7.8%, p = 0.025) and atypical angina (29.4% vs. 6.5%, p = 0.016). Conclusion: Take-off level, intramural course, and slit-like ostium were the main predictors of abnormal CT-FFR values. Importantly, patients with abnormal CT-FFR values showed a higher prevalence of typical angina and atypical angina, indicating that CT-FFR is a potential tool to gauge the clinical relevance in patients with interarterial R-ACAOS.

Purification and Characterization of an Antioxidant Protein from Fertilized Eggs

Yang, Shaohua,Tang, Zhengjiang,Tang, ShanShan,Zhang, Tingfang,Tang, Fei,Wu, Yu,Wang, Ying,Wang, Lu Lu,Liu, Guoqing Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.6

Free radicals may attack cells or tissue, leading to chronic diseases, and antioxidant consumption is potentially useful for removing free radicals. Egg proteins may be used as potential sources of antioxidant considering their ability of scavenging free radicals to apply for food or cosmetics industry. In this study, we obtained a natural antioxidant protein from fertilized eggs, which was a dietary supplement in some Asian countries. Meanwhile, antioxidant activities of these proteins were evaluated using different oxidation systems. With increasing incubation time, the antioxidant activity of these proteins increased during 15 d of incubation. The samples on day 15 were performed for isolation of antioxidant protein. The protein, named P4-1 (MW, 45 kDa), was isolated and purified by consecutive chromatographic methods. P4-1 contained 17 amino acids, which was determined by liquid chromatography-mass spectrometry and Amino Acid Analyzer. Moreover, the amino acid sequence was highly similar to that of ovalbumin. Differential scanning calorimetry showed that the denaturation temperature of P4-1 was $57.16^{\circ}C$. Furthermore, P4-1 suggested high oxygen radical-absorbance activity in ${\cdot}OH$ assays, and its antioxidant activity was stable at $30-50^{\circ}C$ in acidic and neutral pH. Thus, these results revealed that P4-1 may be a potential resource as a natural antioxidant.

Cyclic response of self-centering SRC walls with frame beams as boundary

Lu Sui,Hanheng Wu,Penghui Tang,Tao Gong,Yifan Wang 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.1

In recent years, earthquake resilient structures have become a research focus in the field of seismic engineering. In order to improve the resilience of steel frame - concrete wall panel structures, an innovative self-centering SRC wall panels with replaceable energy dissipaters is presented in the paper. For this purpose, the tested subassembly involving the self-centering SRC walls with frame beams as boundary was presented. The wall panels used in steel moment frames can provide the lateral resistance for structures. Test models of the wall panels with partial framed beams as boundary were suggested. The full-scale specimens were tested under cyclic lateral loads. The configuration of energy dissipaters and initial force of PT steel bars were varied to study their impacts on lateral behavior of the walls. Furthermore, the numerical models based on ABAQUS were developed. The parameter studies, including diameter of PT tendons, beam profile, beam span and wall width, were then conducted. The PT tendons can provide self-centering ability and the dampers are used to dissipate energy. The failure of the wall panels is mainly concentrated on energy dissipaters. This case makes it possible to repair the walls easily.

Preliminary study on the effect of using unmanned aerial vehicles (UAVs) to control Spodoptera frugiperda

Lu Hui,Li Fen,Zhu Xiaoming,Tang Jihong,Lyu Baoqian,Wu Shaoying 한국곤충학회 2021 Entomological Research Vol.51 No.9

Spraying insecticides by unmanned aerial vehicle (UAV) is an effective method to prevent and control Spodoptera frugiperda. This study investigated the influences of different UAV types, spray adjuvants, spray times, maize growth periods, and insecticides on S. frugiperda in three cities, Hainan Province, China. The results showed that at least two times are needed to spray insecticides using UAVs when controlling the S. frugiperda. Both UAVs had a substantially higher control effect and lower cost than artificial spray methods. Oil spray adjuvant Refei was more suitable for both UAVs than Tiancheng to control pests. Chlorantraniliprole had the best control effect of up to 90%. The control effects at the seedling stage and small bell stage of S. frugiperda were 94.3% and 91.3%, respectively. Spraying at 7:00 am and 7:00 pm by UAVof T20 had good control effect on S. frugiperda in three cities.

A NEW CORE – SHELL HYBRID NANOSTRUCTURES OF GOLD NANOROD FOR ENHANCING FLUORESCENCE AND APPLICATION IN DUAL-COLOR IMAGING

LU ZHANG,Peihui Yang,YAN-JIE GUO,JIAN-JUN LUO,GUI-MIN SUN,ZHI-HONG LIANG,YAN-JUAN TANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.3

A novel core – shell hybrid nanostructure was constructed by employing gold nanorod (AuNR)combined with rhodamine B (RB) as a core and silica as a shell. The poly(sodium 4-styr-enesulfonate) (PSS), a negatively charged polyelectrolyte, played the role of linker to electro-statically trap RB on AuNRs. Due to the °uorescence spectral overlap between RB and AuNRs at560 nm, the red °uorescence and enhanced green °uorescence of the hybrid nanostructures wereobserved obviously, which is capable for dual-color labeling. To reduce toxic side e®ects ofAuNRs, silica was coated on AuNRs as a shell to fabricate the novel core – shell hybrid nano-structure function as a dual-color labeling for cancer-cell imaging. The fabricated compositestructures were characterized by transmission electron microscopy (TEM), absorption spectrum,°uorescence spectrum, zeta potential measurements and laser scanning confocal microscope(LSCM). The experiment results con¯rmed that the obtained hybrid nanostructures providedexcellent photostability, biocompatibility and active surface for further biological functionali-zation. The novel composite structures may have great potential application in cell multicolorlabeling and imaging instead of traditional °uorescent dyes.

A proposed model of the pressure field in a downburst

Tang, Z.,Lu, L.Y. Techno-Press 2013 Wind and Structures, An International Journal (WAS Vol.17 No.2

Pressure field and velocity profiles in a thunderstorm downburst are significantly different from that of an atmospheric boundary layer wind. A model of the pressure field in a downburst is presented in accordance with the experimental and numerical results. Large eddy simulation method is employed to investigate transient pressure field on impingement ground of a downburst. In addition, velocity profiles of the downburst are studied, and good agreement is achieved between the present results and the data obtained from empirical models.

A Privacy-preserving and Energy-efficient Offloading Algorithm based on Lyapunov Optimization

Lu Chen,Hongbo Tang,Yu Zhao,Wei You,Kai Wang 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.8

In Mobile Edge Computing (MEC), attackers can speculate and mine sensitive user information by eavesdropping wireless channel status and offloading usage pattern, leading to user privacy leakage. To solve this problem, this paper proposes a Privacy-preserving and Energy-efficient Offloading Algorithm (PEOA) based on Lyapunov optimization. In this method, a continuous Markov process offloading model with a buffer queue strategy is built first. Then the amount of privacy of offloading usage pattern in wireless channel is defined. Finally, by introducing the Lyapunov optimization, the problem of minimum average energy consumption in continuous state transition process with privacy constraints in the infinite time domain is transformed into the minimum value problem of each timeslot, which reduces the complexity of algorithms and helps obtain the optimal solution while maintaining low energy consumption. The experimental results show that, compared with other methods, PEOA can maintain the amount of privacy accumulation in the system near zero, while sustaining low average energy consumption costs. This makes it difficult for attackers to infer sensitive user information through offloading usage patterns, thus effectively protecting user privacy and safety.

Synthesis of sulfonated catalyst from bituminous coal to catalyze esterification for biodiesel production with promoted mechanism analysis

Tang Xincheng,Niu Shengli,Zhao Shuang,Zhang Xiangyu,Li Ximing,Yu Hewei,Lu Chunmei,Han Kuihua 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.77 No.-

The carbon-based heterogeneous acid catalyst is synthesized from bituminous coal through the partialcarbonization and sulfonation method and applied to catalyze the esterification of oleic acid withmethanol for biodiesel production. Various characterization methods are used to explain catalyticfeatures and molecular simulation is conducted to analyze the promoted mechanism of acid catalyst inesterification. Carbon catalyst, prepared by partially carbonized at 350 C and sulfonated at 105 C,catalyzes esterification with biodiesel yield of 98.70%. Transition state analysis implies that acid catalystreduces the activation energy through providing proton to promote esterification.

Quantum spin Hall state in monolayer 1T'-WTe₂

Tang, Shujie,Zhang, Chaofan,Wong, Dillon,Pedramrazi, Zahra,Tsai, Hsin-Zon,Jia, Chunjing,Moritz, Brian,Claassen, Martin,Ryu, Hyejin,Kahn, Salman,Jiang, Juan,Yan, Hao,Hashimoto, Makoto,Lu, Donghui,Moore NATURE PUBLISHING GROUP 2017 NATURE PHYSICS Vol.13 No.7

<P>A quantum spin Hall (QSH) insulator is a novel two-dimensional quantum state of matter that features quantized Hall conductance in the absence of a magnetic field, resulting from topologically protected dissipationless edge states that bridge the energy gap opened by band inversion and strong spin-orbit coupling(1,2). By investigating the electronic structure of epitaxially grown monolayer 1T'-WTe2 using angle-resolved photoemission (ARPES) and first-principles calculations, we observe clear signatures of topological band inversion and bandgap opening, which are the hallmarks of a QSH state. Scanning tunnelling microscopy measurements further confirm the correct crystal structure and the existence of a bulk bandgap, and provide evidence for a modified electronic structure near the edge that is consistent with the expectations for a QSH insulator. Our results establish monolayer 1T'-WTe2 as a new class of QSH insulator with large bandgap in a robust two-dimensional materials family of transition metal dichalcogenides (TMDCs).</P>