The detection efficiency study of NaI(Tl) scintillation detector with the different numbers of SiPMs

Wang Bao,Zhang Xiongjie,Wang Qingshan,Wang Dongyang,Li Dong,Xiahou Mingdong,Zhou Pengfei,Ye Hao,Hu Bin,Zhang Lijiao 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.7

SiPMs are generally coupled into whole columns in gamma energy spectrum measurement, but the relationship between the distribution of whole SiPM columns and the energy resolution of the measured energy spectra is rarely reported. In this work, ∅ 3 3 inch NaI scintillator is placed on an 8 8 SiPM array, and the energy resolution of the 137Cs peak at 662 keV corresponding to the g-ray is selected as a reference. Each SiPM is switched to explore the influence of the number of SiPM arrays, distribution position, and reflective layer on the energy resolution of SiPMs. Results show that without coupling, the energy resolution is greatly improved when the number of SiPMs ranges from 4 to 32. However, after 32 slices (the area covered by SiPMs relative to the scintillator reaches 25.9%), the improvement in energy resolution and total pulse count is not obvious. In addition, the position of SiPMs relative to the scintillator does not exert much impact on the energy resolution. Results also indicate that by adding a reflective film (ESR), the energy resolution of the tested group increases by 10.38% on average. This work can provide a reference for the design and application of miniaturized SiPM gamma spectrometers

Distortional buckling of cold-formed lipped channel columns subjected to axial compression

Wang-Bao Zhou,Lizhong Jiang 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.23 No.3

Cold-formed lipped channel columns (CFLCCs) have been widely used in light gauge steel constructions. The distortional buckling is one of the important buckling modes for CFLCCs and the distortional buckling critical load depends significantly on the rotational restrain stiffness generated by the web to the lipped flange. First, a simplified explicit expression for the rotational restraint stiffness of the lipped flange has been derived. Using the expression, the characteristics of the rotational restraint stiffness of the lipped flange have been investigated. The results show that there is a linear coupling relationship between the applied forces and the rotational restraint stiffness of the lipped flange. Based on the explicit expression of the rotational restraint stiffness of the lipped flange, a simplified analytical formula has been derived which can determine the elastic distortional buckling critical stress of the CFLCCs subjected to axial compression. The simplified analytical formula developed in this study has been shown to be accurate through the comparisons with results from the distortional buckling analyses using the ANSYS finite element software. The developed analytical formula is easy to apply, and can be used directly in practical design and incorporated into future design codes and guidelines.

Multi-channel analyzer based on a novel pulse fi tting analysis method

Qingshan Wang,Xiongjie Zhang,Xiangting Meng,Bao Wang,Dongyang Wang,Pengfei Zhou,Renbo Wang,Bin Tang 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6

A novel pulse fitting analysis (PFA) method is presented for the acquisition of nuclear spectra. Thecharging process of the feedback capacitor in the resistive feedback charge-sensitive preamplifier isequivalent to the impulsive pulse, and its impulse response function (IRF) can be obtained by non-linearfitting of the falling edge of the nuclear pulse. The integral of the IRF excluding the baseline representsthe energy deposition of the particles in the detector. In addition, since the non-linear fitting process inPFA method is difficult to achieve in the conventional architecture of spectroscopy system, a new multichannel analyzer (MCA) based on Zynq SoC is proposed, which transmits all the data of nuclear pulsesfrom the programmable logic (PL) to the processing system (PS) by high-speed AXI-Stream in order toimplement PFA method with precision. The linearity of new MCA has been tested. The spectrum of 137Cswas obtained using LaBr3(Ce) scintillator detector, and was compared with commercial MCA by ORTEC. The results of tests indicate that the MCA based on PFA method has the same performance as thecommercial MCA based on pulse height analysis (PHA) method and excellent linearity for g-rays withdifferent energies, which infers that PFA method is an effective and promising method for the acquisitionof spectra. Furthermore, it provides a new solution for nuclear pulse processing algorithms involvingregression and iterative processes

Multi-energy coordinated regulation strategy based on the decomposition of large-scale new energy fluctuations

BAO Guangqing,ZHOU Jiawu,MA Ming,WANG Ningbo 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The high volatility and weak support of wind, photovoltaic power generation and other new energy sources have a negative impact on the stability of the power system. Therefore, the power spectrum density of the power curve compensating the combined output of wind power and photovoltaic power was analyzed by discrete Fourier transform (DFT)based on the study of the random fluctuation characteristics of wind power and photovoltaic output, and the multi-energy frequency division compensation control mode of thermal power, hydropower and energy storage was proposed to deal with the fluctuation of high proportion of new energy grid-connection.Firstly, the wave compensation is decomposed into low frequency, medium frequency and high frequency components by two wavelet packet decomposition.Then the annual operating cost is minimized to optimize the capacity of different compensation units according to the output characteristics of differ-ent energy units on the basis of introducing the penalty coefficient of fluctuation. By analyzing the data of wind farm group and photovoltaic power station in a western region, the correctness and feasibility of the proposed scheduling optimization method are verified.

Construction of a Protein-Protein Interaction Network for Chronic Myelocytic Leukemia and Pathway Prediction of Molecular Complexes

Zhou, Chao,Teng, Wen-Jing,Yang, Jing,Hu, Zhen-Bo,Wang, Cong-Cong,Qin, Bao-Ning,Lv, Qing-Liang,Liu, Ze-Wang,Sun, Chang-Gang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: Chronic myelocytic leukemia is a disease that threatens both adults and children. Great progress has been achieved in treatment but protein-protein interaction networks underlining chronic myelocytic leukemia are less known. Objective: To develop a protein-protein interaction network for chronic myelocytic leukemia based on gene expression and to predict biological pathways underlying molecular complexes in the network. Materials and Methods: Genes involved in chronic myelocytic leukemia were selected from OMIM database. Literature mining was performed by Agilent Literature Search plugin and a protein-protein interaction network of chronic myelocytic leukemia was established by Cytoscape. The molecular complexes in the network were detected by Clusterviz plugin and pathway enrichment of molecular complexes were performed by DAVID online. Results and Discussion: There are seventy-nine chronic myelocytic leukemia genes in the Mendelian Inheritance In Man Database. The protein-protein interaction network of chronic myelocytic leukemia contained 638 nodes, 1830 edges and perhaps 5 molecular complexes. Among them, complex 1 is involved in pathways that are related to cytokine secretion, cytokine-receptor binding, cytokine receptor signaling, while complex 3 is related to biological behavior of tumors which can provide the bioinformatic foundation for further understanding the mechanisms of chronic myelocytic leukemia.

The impacts of LPCVD wrap-around on the performance of n-type tunnel oxide passivated contact c-Si solar cell

Zhou Ying,Tao Ke,Liu Aimin,Rui Jia,Bao Jianhui,Sun Yufeng,Yang Sanchuan,Wang Qinqin,Zhang Qiang,Yang Songbo,Cao Yujia,Qu Hui 한국물리학회 2020 Current Applied Physics Vol.20 No.7

In this paper, Tunnel Oxide Passivated Contact (TOPCon) silicon solar cells with the industrial area (244.32 cm2) are fabricated on N-type silicon substrates. Both the ultra-thin tunnel oxide layer and phosphorus doped polycrystalline silicon (polysilicon) thin film are prepared by the LPCVD system. The wrap-around of polysilicon is observed on the surface of borosilicate glass (BSG). The polysilicon wrap-around can form a leakage current path, thus degrades the shunt resistance of solar cells, and leads to the degradation of solar cell efficiency. Different methods are adopted to treat the polysilicon wrap-around and improve shunt resistance of solar cells. The experimental results indicate that a chemical etching method can effectively solve the problem of polysilicon wrap-around and improve the performance of solar cells. Finally, a conversion efficiency of 22.81% has been achieved by our bifacial TOPCon solar cells, with Voc of 702.6 mV, Jsc of 39.78 mA/cm2 and FF of 81.62%.

Identification of Second Order System with Inductive Storage Element Using Signal Compression Method and Applying SMCSPO

Zhou Yudong,Gao Xueguan,Wang Jie,Bao Yulong,Min Cheol Lee 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

In this paper, we propose a new method based on signal compression method (SCM) to identify the system that contains dynamic parameters including the capacitive storage, energy dissipator, inductive storage terms. A typical DC motor system is set up and utilized to describe this method. Based on this method, sliding mode control with sliding perturbation observer (SMCSPO) is applied to design controllers. A simulation is performed to express the significance of thorough estimation of the system for the performance of the controller, and this research also experimentally demonstrates that the controller designed based on the dynamics estimated by the method of this paper can have great output tracking performance in a real physical system.

Excellent microwave absorption of FeCo/ZnO composites with defects in ZnO for regulating the impedance matching

Bao, Xiukun,Wang, Xiaolei,Zhou, Xinao,Shi, Guimei,Xu, Ge,Yu, Jin,Guan, Yinyan,Zhang, Yajing,Li, Da,Choi, Chuijin Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.769 No.-

<P><B>Abstract</B></P> <P>FeCo/ZnO composites have been successfully prepared through liquid-phase reduction process for the formation of FeCo polyhedrons and sequentially thermal decomposition of colloidal mixture of FeCo and Zn(Ac)<SUB>2</SUB>·2H<SUB>2</SUB>O under nitrogen atmospheres. ZnO nanoparticles are homogeneously deposited on the surface of FeCo polyhedrons and the level of oxygen-vacancy defects in ZnO can be elevated with the increase of ZnO content. By comparison with FeCo polyhedrons, FeCo/ZnO composites exhibit excellent microwave absorption. The optimal RL value can reach −34.8 dB at 14.8 GHz and effective bandwidth (RL < −10 dB) is 5.1 GHz in the frequency range of 12.4–17.5 GHz with a matching thickness of 1.5 mm. The integrated bandwidth with RL < −10 dB can reach 14.1 GHz covering 3.4–17.5 GHz. Theory analysis demonstrates the interfacial polarization, dipole polarization and high conductivity due to oxygen-vacancy defects in FeCo/ZnO composites contribute to enhancement of dielectric loss capacity, which is more favorable for impedance matching.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The preferable impedance matching of FeCo/ZnO composites can be achieved by regulating the ZnO content. </LI> <LI> The optimal reflection loss (RL) can reach −34.8 dB with a matching thickness of 1.5 mm. </LI> <LI> The effective bandwidth with RL < −10 dB achieve 14.1 GHz covering 3.4–17.5 GHz with integrated thickness of 1.5–5 mm. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Combined Pharmacophore-Based Virtual Screening, Docking Study and Molecular Dynamics (MD) Simulation Approach to Identify Inhibitors with Novel Scaffolds for Myeloid cell leukemia (Mcl-1)

Bao, Guang-Kai,Zhou, Lu,Wang, Tai-Jin,He, Lu-Fen,Liu, Tao Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.7

Chemical feature based quantitative pharmacophore models were generated using the HypoGen module implemented in DS2.5. The best hypothesis, Hypo1, which was characterized by the highest correlation coefficient (0.96), the highest cost difference (61.60) and the lowest RMSD (0.74), consisted of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic and one ring aromatic. The reliability of Hypo1 was validated on the basis of cost analysis, test set, Fischer's randomization method and GH test method. The validated Hypo1 was used as a 3D search query to identify novel inhibitors. The screened molecules were further refined by employing ADMET, docking studies and visual inspection. Three compounds with novel scaffolds were selected as the most promising candidates for the designing of Mcl-1 antagonists. Finally, a 10 ns molecular dynamics simulation was carried out on the complex of receptor and the retrieved ligand to demonstrate that the binding mode was stable during the MD simulation.

Silibinin Inhibits Proliferation, Induces Apoptosis and Causes Cell Cycle Arrest in Human Gastric Cancer MGC803 Cells Via STAT3 Pathway Inhibition

Wang, Yi-Xin,Cai, Hong,Jiang, Gang,Zhou, Tian-Bao,Wu, Hai Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Background: To investigate the effect of silibinin on proliferation and apoptosis in human gastric cancer cell line MGC803 and its possible mechanisms. Materials and Methods: Human gastric cancer cell line MGC803 cells were treated with various concentration of silibinin. Cellular viability was assessed by CCK-8 assay andapoptosis and cell cycle distribution by flow cytometry. Protein expression and mRNA of STAT3, and cell cycle and apoptosis regulated genes were detected by Western blotting and real-time polymerase chain reaction, respectively. Results: Silibinin inhibits growth of MGC803 cells in a dose- and time-dependent manner. Silibinin effectively induces apoptosis of MGC803 cells and arrests MGC803 cells in the G2/M phase of the cell cycle, while decreasing the protein expression of p-STAT3, and of STAT3 downstream target genes including Mcl-1, Bcl-xL, survivin at both protein and mRNA levels. In addition, silibinin caused an increase in caspase 3 and caspase 9 protein as well as mRNA levels. Silibinin caused G2/M phage arrest accompanied by a decrease in CDK1 and Cyclin B1 at protein and mRNA levels.. Conclusions: These results suggest that silibinin inhibits the proliferation of MGC803 cells, and it induces apoptosis and causes cell cycle arrest by down-regulating CDK1, cyclinB1, survivin, Bcl-xl, Mcl-1 and activating caspase 3 and caspase 9, potentially via the STAT3 pathway.