Necessary Experimental Conditions for Single-Shot Diffraction Imaging of DNA-Based Structures with X-ray Free-Electron Lasers

Sun, Zhibin,Fan, Jiadong,Li, Haoyuan,Liu, Huajie,Nam, Daewoong,Kim, Chan,Kim, Yoonhee,Han, Yubo,Zhang, Jianhua,Yao, Shengkun,Park, Jaehyun,Kim, Sunam,Tono, Kensuke,Yabashi, Makina,Ishikawa, Tetsuya,So American Chemical Society 2018 ACS NANO Vol.12 No.8

<P>It has been proposed that the radiation damage to biological particles and soft condensed matter can be overcome by ultrafast and ultraintense X-ray free-electron lasers (FELs) with short pulse durations. The successful demonstration of the “diffraction-before-destruction” concept has made single-shot diffraction imaging a promising tool to achieve high resolutions under the native states of samples. However, the resolution is still limited because of the low signal-to-noise ratio, especially for biological specimens such as cells, viruses, and macromolecular particles. Here, we present a demonstration single-shot diffraction imaging experiment of DNA-based structures at SPring-8 Angstrom Compact Free Electron Laser (SACLA), Japan. Through quantitative analysis of the reconstructed images, the scattering abilities of gold and DNA were demonstrated. Suggestions for extracting valid DNA signals from noisy diffraction patterns were also explained and outlined. To sketch out the necessary experimental conditions for the 3D imaging of DNA origami or DNA macromolecular particles, we carried out numerical simulations with practical detector noise and experimental geometry using the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory, USA. The simulated results demonstrate that it is possible to capture images of DNA-based structures at high resolutions with the technique development of current and next-generation X-ray FEL facilities.</P> [FIG OMISSION]</BR>

Analysis of the extrusion pressure of a cylindrical extruder for extruding highly viscous fluids

Zhibin Sun,Baojun Shen,Yu He,Jiecai Long,Xiaobin Zhan,Yujin Li,Xiwen Li 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.10

Extrusion pressure is crucial for the security and performance of a cylindrical extruder during the extrusion process. In this study, a validated CFD model was adopted to evaluate the relationship between the extrusion velocity, fluid viscosity, and the extrusion pressure of a cylindrical extruder while extruding highly viscous fluids. The simulated and experimental results of the extrusion pressure and velocity profiles show good agreement. This study reveals that extrusion pressure evolution can be divided into two stages during the extrusion process. At stage I, the distance between the ram and the bottom of the vessel (liquid height) is greater than the critical height and the extrusion pressure remains almost constant. At stage II, the distance is less than the critical height and the extrusion pressure increases exponentially. The results indicate that an increase in extrusion velocity and fluid viscosity leads to a linear increase in the extrusion pressure at stage I. Furthermore, by introducing a pressure number, Np, and a pressurerelated Reynolds number, Rep, a novel correlation of the extrusion pressure with the extrusion velocity, viscosity of highly viscous fluids and liquid height has been developed.

An exchange bias observed in Tb/Cr/FeCo trilayers with ultrathin Cr layer at low temperature

Sun Li,Li Xiaoyan,Zhang Yiwei,Song Hengbo,Zhang Wen,Kou Zhaoxia,Zhang Dong,Liu Xiaoying,Fei Hongyang,Pan Mengmei,Zhao Zhibin,Zhai Ya 한국물리학회 2022 Current Applied Physics Vol.44 No.-

Positive exchange bias field (He) is observed in Tb/Cr (tCr)/FeCo trilayers at 5 K without cooling field, and negative He for Tb/FeCo bilayer. The negative He of Tb/FeCo implies the FM coupling at the interface due to Co and Fe dominate in the magnetization of the ferrimagnetic interlayer alloy of FeCo and Tb. With the inserting of Cr layer, this situation is broken, and the positive He implies the antiferromagnetic interlayer coupling. A peak of He = 6.0 mT for trilayers with tCr = 1.5 nm is corresponding to the minimum value of coercivity as a function of tCr at 5 K, which is used to study the effect of the cooling field (Hfc) on He as a function of temperature. It is found that Hfc of 100 mT triggers He from positive to negative at T ≤ 15 K. The magnetoresistance results also confirm the coexistence of multiple MR mechanisms in these trilayers.

Review : Purification and Characterization of a Novel Extracellular Thermostable Alkaline Protease from Streptomyces sp. M30

( Yan Xin ),( Zhibin Sun ),( Qiongzhen Chen ),( Jue Wang ),( Yicheng Wang ),( Linfeng Luogong ),( Shuhuan Li ),( Weiliang Dong ),( Zhongli Cui ),( Yan Huang ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.11

A novel alkaline protease from Streptomyces sp. M30, SapHM, was purified by ammonium sulfate precipitation, hydrophobic interaction chromatography, and DEAE-Sepharose chromatography, with a yield of 15.5% and a specific activity of 29,070 U/mg. Tryptic fragments of the purified SapHM were obtained by electrospray ionization quadrupole timeof- flight mass spectrometry. Nucleotide sequence analysis revealed that the gene sapHM contained 1,179 bp, corresponding to 392 amino acids with conserved Asp156, His187, and Ser339 residues of alkaline protease. The first 24 amino acid residues were predicted to be a signal peptide, and the molecular mass of the mature peptide was 37.1 kDa based on amino acid sequences and mass spectrometry. Pure SapHM was optimally active at 80°C in 50 mM glycine-NaOH buffer (pH 9.0), and was broadly stable at 0-50°C and pH 4.0-9.0. The protease relative activity was increased in the presence of Ni2+, Mn2+, and Cu2+ to 112%, 113%, and 147% of control, respectively. Pure SapHM was also activated by dimethylformamide, dimethyl sulfoxide, Tween 80, and urea. The activity of the purified enzyme was completely inhibited by phenylmethylsulfonyl fluoride, indicating that it is a serine-type protease. The Km and Vmax values were estimated to be 35.7 mg/ml, and 5 × 104 U/mg for casein. Substrate specificity analysis showed that SapH was active on casein, bovine serum albumin, and bovine serum fibrin.

Influence of Device Parameters Spread on Current Distribution of Paralleled Silicon Carbide MOSFETs

Junji Ke,Zhibin Zhao,Peng Sun,Huazhen Huang,James Abuogo,Xiang Cui 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

This paper systematically investigates the influence of device parameters spread on the current distribution of paralleledsilicon carbide (SiC) MOSFETs. First, a variation coefficient is introduced and used as the evaluating norm for the parametersspread. Then a sample of 30 SiC MOSFET devices from the same batch of a well-known company is selected and tested underthe same conditions as those on datasheet. It is found that there is big difference among parameters spread. Furthermore,comprehensive theoretical and simulation analyses are carried out to study the sensitivity of the current imbalance to variationsof the device parameters. Based on the concept of the control variable method, the influence of each device parameter on thesteady-state and transient current distributions of paralleled SiC MOSFETs are verified separately by experiments. Finally, somescreening suggestions of devices or chips before parallel-connection are provided in terms of different applications and differentdriver configurations.

Research on the Load-slip Properties of Corrugated rib connectors' Push-out Test

Shuqin Li,Lichao Su,Zhibin Sun 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.4

The failure characteristic and load-slip performance of corrugated rib connectors under static load were investigated usingthe push-out test combined with Finite Element Analysis (FEA). The results obtained from experiment and FEA indicate thatthe shear bearing capacity of the corrugated rib connectors are closely relate with the key factors including cubic strength ofconcrete (fcu), the open area of the steel plate (Ac1), perforated rebar tensile yield strength (fy) and Cross-sectional area (Ay),horizontal projection area of corrugated rib (= dwhw). In elastic stage, the overall shear stiffness of the corrugated rib connectorare mainly affected by the shear stiffness of the concrete bars. And in elastic-plastic stage, the shear stiffness of the concretebars and perforated rebar pronouncedly influence the overall shear stiffness of the corrugated rib connector. Finally, a linearmodel and a power law model for the load-slip behavior at elastic stage and elastic-plastic stage are provided based on theregression statistical analysis, respectively.

Influence of Device Parameters Spread on Current Distribution of Paralleled Silicon Carbide MOSFETs

Ke, Junji,Zhao, Zhibin,Sun, Peng,Huang, Huazhen,Abuogo, James,Cui, Xiang The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

This paper systematically investigates the influence of device parameters spread on the current distribution of paralleled silicon carbide (SiC) MOSFETs. First, a variation coefficient is introduced and used as the evaluating norm for the parameters spread. Then a sample of 30 SiC MOSFET devices from the same batch of a well-known company is selected and tested under the same conditions as those on datasheet. It is found that there is big difference among parameters spread. Furthermore, comprehensive theoretical and simulation analyses are carried out to study the sensitivity of the current imbalance to variations of the device parameters. Based on the concept of the control variable method, the influence of each device parameter on the steady-state and transient current distributions of paralleled SiC MOSFETs are verified separately by experiments. Finally, some screening suggestions of devices or chips before parallel-connection are provided in terms of different applications and different driver configurations.

Dynamic performance of 6.5 kV SiC MOSFET body diodes and anti‑parallel Schottky barrier diodes

Yujie Du,Xinling Tang,Xiaoguang Wei,Shuai Sun,Fei Yang,Zhibin Zhao 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.6

For a silicon carbide (SiC) metal–oxide–semiconductor fi eld-eff ect transistor (MOSFET), both the body diode of the MOSFET and an anti-parallel diode can function as a freewheeling diode that carries reverse current. Selecting a suitable freewheeling method is particularly important to fully exploit the performance of high-voltage SiC MOSFET devices. In this study, based on the 6.5 kV SiC MOSFET and the Schottky barrier diode (SBD) developed by our research group, the dynamic characteristics of the MOSFET body diode, the SBD, and the parallel connection of the two are investigated. In addition, the influence of capacitive current on the dynamic characteristics is analyzed by establishing an equivalent circuit model. Test results show that when compared with the body diode, the SBD has an extremely low reverse recovery current, a lower capacitive current, and better reverse recovery temperature stability. Thus, the SBD is regarded as the most suitable freewheeling diode for the 6.5 kV SiC MOSFET. Finally, a package solution for the 6.5 kV SiC MOSFET and SBD is proposed.

Shaking Table Test of Water Supply Pipes Installed in a Full-Scale Masonry Structure

Houli Wu,Endong Guo,Dezhang Sun,Chenxi Mao,Haoyu Zhang,Zhibin Liu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

The seismic performance of indoor water supply pipes plays a significant role during earthquakes, and the failure of pipes causes severe economic losses and other disasters. This paper presents shaking table test research on water supply pipes installed in a full-scale masonry structure. Three different material pipes and three different material fillers were combined to evaluate the difference in seismic performance. In this study, normalized floor response spectra and pipe acceleration amplification factors obtained from experimental data were compared with code provisions. Spectrum analysis was used to evaluate the pipeline seismic response, and the results showed that the combination of pipes and fillers with similar material properties vibrated partially at multiple frequencies. In contrast, the combination of pipes and fillers with very different material properties only vibrated near the predominant structural period.

Comparisons of Safety Factors for Slope in Nonlinear Soils

Chaoqun Hou,Rongjian Zhang,Yongxin Li,Zhibin Sun,Biao Zhang 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.10

Slope stability assessment is one of the most important issues for geotechnical engineers. In the framework of a nonlinear failure criterion, four different types of safety factors are presented and their relationships are investigated for soil slope in this study. The variational method is incorporated into the kinematic approach of limit analysis to assess the stability of soil slope with known geometric boundary, and seismic effects are considered. The seismic loads are simplified as external forces acting on the slope. A rotational failure mechanism is used to describe the sliding mode of slopes. The differential equations for the sliding surface and corresponding stress distribution are derived using the variational method and then are employed to generate the sliding surface via the fourth-order Runge-Kutta approach. To avoid the computational complexity, the energy-work balance equation of the kinematic approach, instead of the static equilibrium equation, is used to judge whether the state of the slope is critical. The safety factor is designed as the minimum factor that brings the slope in the limit state. Computational schemes are proposed to calculate the values of safety factors. The validity of the proposed approach is demonstrated through comparison with previous works. Finally, parametric study is conducted to further reveal the relationships among the four types of safety factors.