A cosmic ray muons tomography system with triangular bar plastic scintillator detectors and improved 3d image reconstruction algorithm: A simulation study

Zhao Yanwei,Luo Xujia,Qin Kemian,Liu Guorui,Chen Daiyuan,Augusto R.S.,Zhang Weixiong,Luo Xiaogang,Liu Chunxian,Liu Juntao,Liu Zhiyi 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.2

Purpose: Muons are characterized by a strong penetrating ability and can travel through thousands of meters of rock, making them ideal to image large volumes and substances typically impenetrable to, for example, electrons and photons. The feasibility of 3D image reconstruction and material identification based on a cosmic ray muons tomography (MT) system with triangular bar plastic scintillator detectors has been verified in this paper. Our prototype shows potential application value and the authors wish to apply this prototype system to 3D imaging. In addition, an MT experiment with the same detector system is also in progress. Methods: A simulation based on GEANT4 was developed to study cosmic ray muons' physical processes and motion trails. The yield and transportation of optical photons scintillated in each triangular bar of the detector system were reproduced. An image reconstruction algorithm and correction method based on muon scattering, which differs from the conventional PoCA algorithm, has been developed based on simulation data and verified by experimental data. Results: According to the simulation result, the detector system’s position resolution is below 1 ~ mm in simulation and 2 mm in the experiment. A relatively legible 3D image of lead bricks in size of 20 cm 5 cm 10 cm used our inversion algorithm can be presented below 1 104 effective events, which takes 16 h of acquisition time experimentally. Conclusion: The proposed method is a potential candidate to monitor the cosmic ray MT accurately. Monte Carlo simulations have been performed to discuss the application of the detector and the simulation results have indicated that the detector can be used in cosmic ray MT. The cosmic ray MT experiment is currently underway. Furthermore, the proposal also has the potential to scan the earth, buildings, and other structures of interest including for instance computerized imaging in an archaeological framework.

Research Framework for Risk Management on Civil Engineering Projects Invested by Chinese Government

Yanwei Wang,Xingzhi Liu 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Due to the characteristic of social public welfare and huge scale, civil engineering projects invested by government are the majority part of investment in fixed assets in China. However, as the current investment management mechanism joined together with Investment, Construction, Management and Operation, there are a large number of projects issues just like a low executive effectiveness, a wastej of recourses, unrealizable objectives. One main reason which causes the issues above is that there is no effective risk management mechanism for civil engineering projects. As there are so many stakeholders and so complex principal-agent relationships, it is not enough to rely on project management by project manager. Research from the view of governance can build a risk management frame work for civil engineering projects so that project risks can be deduced and then utilize on the investment by government can be improved.

Home-Work Separation and the Impacts of Housing Reform and Urban Sprawl : Evidence from Household Survey Data in Beijing, China

LIU Zhilin,CHAI Yanwei,ZHANG Yan 대한지리학회 2008 대한지리학회 컨퍼런스 자료집 Vol.2 No.-

Application of Membrane Filtration Method to Isolate Uninuclei Conidium in Aspergillus oryzae Transformation System Based on the pyrG Marker

Yanwei Ji,Yang Xu,Yanping Li,Zhui Tu,Zhibing Huang,Xue Liu,Da Lei 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.1

The purpose of this study was to develop a membrane filtration method to isolate uninuclei conidium of Aspergillus oryzae, then the method was adopted to develop a transformation system of A. oryzae. A. oryzae 3.951 contained 1–4 nuclei in each conidium. The percentages of uninucleate and binucleate conidia were approximately 16.15 and 74.22%, respectively. Conidia suspension was filtrated with a 5-μm membrane to overcome the bottleneck caused by multinucleate conidia and to remove excess multinucleate conidia before UV mutagenesis. Uninucleate conidia of 5-fluoroorotic acid (5-FOA)-resistant strains were enriched by filtration with a 3-μm membrane. The pyrG mutant strain AS11 was obtained and GFP-pyrG was successfully transformed into AS11.

One-Step Hydrothermal Synthesis of CoNi2S4 for Hybrid Supercapacitor Electrodes

Peng Liu,Yanwei Sui,Fuxiang Wei,Jiqiu Qi,Qingkun Meng,Yaojian Ren,Yezeng He 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

In this study, a simple one-step hydrothermal method was developed to prepare a novel hierarchical CoNi2S4 nanostructure similar to rambutan fruit. The surface microstructural study clearly visualized that the rambutan-like CoNi2S4 consists of nanorods grown directly on the surface of spherical core structures. The close attachment of the nanorods to the spheres increased the active areas of the electrode, which facilitates efficient charge transport from the nanorods to the spherical core structure. CoNi2S4 with a rambutan-like hierarchical structure showed an excellent specific capacitance of 944 F g -1 at 1 A g -1, considerable rate capacitance (75.6% retention at 10 Ag -1) and excellent cycling life (91.1% retention after 5000 circulations) in the three-electrode system. Besides, the assembled hybrid supercapacitor based on CoNi2S4 and reduced graphene oxide exhibited a high specific energy density of 23.58 Wh kg -1 at the power density of 800 W kg -1.

Controllable Zn0.76Co0.24S Nanoflower Arrays Grown on Carbon Fiber Papers for High-Performance Supercapacitors

Man Zhang,Yanwei Sui,Xiaofang Yuan,Jiqiu Qi,Fuxiang Wei,Qingkun Meng,Yezeng He,Yaojian Ren,Zhi Sun,Jinlong Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

A nanoflower structure of Zn0.76Co0.24S directly grown on carbon fiber papers (CFP) was successfully designed by a mild two-step hydrothermal method. Benefiting from their fascinating structural features, Zn0.76Co0.24S/CFP electrode exhibits a maximum specific capacitance of 300 F g -1 at current density of 1 A g -1 and 84% capacitance retention after 5,000 cycles at current density of 5 Ag -1. Subsequently, Zn0.76Co0.24S/CFP//AC all-solid-state asymmetric supercapacitor (ASC) device is assembled and able to illuminate the red LEDs. ASC devices deliver a maximum energy density of 9.59 Wh kg -1 at a power density of 750 W kg -1. Therefore, this impressive result demonstrates that the nanoflower Zn0.76Co0.24S have promising applications in the development of high-performance supercapacitors.

TRAJECTORY PLANNING ALGORITHM USING GAUSS PSEUDOSPECTRAL METHOD BASED ON VEHICLE-INFRASTRUCTURE COOPERATIVE SYSTEM

Yingxuan Zhu,Kegang Zhao,Haolin Li,Yanwei Liu,Quancheng Guo,Zhengtao Liang 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.4

Vehicle-infrastructure cooperative systems can potentially enhance both traffic safety and efficiency by conducting coordinated control through the interactive strategy between the vehicles and the infrastructure. In this study, the interactive strategy of a vehicle infrastructure cooperative system is designed. Lane change maneuver is a conventional behavior in driving. Thus, this paper proposes a trajectory planning algorithm based on a Gauss pseudo-spectral method that is applied to the intelligent vehicle-infrastructure cooperative system in the lane change scenario. A road side unit calculates the planning trajectory using collected vehicle information and sensor data and then sends the trajectory planning advice to the designated vehicle. The Gauss pseudo-spectral method is used to obtain the planning trajectory, which effectively helps solve the discontinuous optimization problems in partial conditions. It transforms the optimal control problem of dynamic systems into a nonlinear programming problem using the orthogonal collocation method to discretize the objective function and various constraints of the optimization problem. Furthermore, the ssuential quadratic programming method is used to solve the problem numerically. The effectiveness of the proposed method and interactive strategy are demonstrated through simulations and experimental results.

Anthocyanins in Tree Peony (Paeonia suffruticosa) and Their Relationship with Flower Color

Yanzhao Zhang,Yan Zhang,Xujia Duan,Xin Liu,Shuiqing Yuan,Jianming Han,Yanwei Cheng 한국원예학회 2020 원예과학기술지 Vol.38 No.6

Flower color is an important trait of tree peony (Paeonia suffruticosa), an economically important species. The accurate classification of flower color and understanding of the mechanism involved in creating variations in flower color provide the basis of tree peony breeding and genetic research. This study used the International Commission of Illumination Color System, known as CIELAB or CIE L<SUP>*</SUP>a<SUP>*</SUP>b<SUP>*</SUP>, to measure the flower color of 150 cultivars of the Zhongyuan cultivar group of tree peony. Hierarchical cluster analysis and visual observations were used to divide this cultivar group into five major color lines: white, pink, red, purple, and fuchsia. The brightness (L<SUP>*</SUP>) of the flower color gradually decreased with an increase in anthocyanin content. The redness (a<SUP>*</SUP>) of the flower color was significantly negatively correlated with total anthocyanin (TA) content in the fuchsia line but was positively correlated with TA in the remaining four color lines. Six types of anthocyanins, including Cy3G, Cy3G5G, Pn3G, Pn3G5G, Pg3G, and Pg3G5G, were mainly found in the Zhongyuan cultivar group by liquid chromatography except in the white line. Stepwise regression analysis showed that Pg3G5G had a significant positive correlation with redness of flower color. Cy3G5G and Pn3G5G had a significant positive correlation with redness in pink, red, and purple color lines. However, Pn3G was negatively correlated with redness in the fuchsia line. This study lays the foundation for further development of new breeds and flower colors in tree peony and for genetic research related to flower color.

ZnO nanowire array ultraviolet photodetectors with self-powered properties

Zhiming Bai,Xiaoqin Yan,Xiang Chen,Hanshuo Liu,Yanwei Shen,Yue Zhang 한국물리학회 2013 Current Applied Physics Vol.13 No.1

A ZnO nanowire (NW) array ultraviolet photodetector (PD) with Pt Schottky contacts has been fabricated on a glass substrate. Under UV light illumination, this PD showed a high photo-to-dark current ratio of 892 at 30 V bias. Interestingly, it was also found that this PD had a high sensitivity of 475 without external bias. This phenomenon could be explained by the asymmetric Schottky barrier height (SBH) at the two ends causing different separation efficiency of photogenerated electronehole pairs, which resulted in the formation of photocurrent. It is anticipated to have potential applications in self-powered UV detection field.

Effect of supplemental blue light intensity on the growth and quality of Chinese kale

Yamin Li,Yinjian Zheng,Houcheng Liu,Yiting Zhang,Yanwei Hao,Shiwei Song,Bingfu Lei 한국원예학회 2019 Horticulture, Environment, and Biotechnology Vol.60 No.1

The infl uence of blue light on the growth and quality of vegetables is controversial, since both positive and negative eff ectshave been observed on diff erent varieties of vegetables and most research has been conducted with a combination of lightspectrums. In this work, we investigated the eff ects of supplemental blue light intensity on growth, nutritional quality, andhealth-promoting compounds of Chinese kale ( Brassica alboglabra Bailey) using only blue (460 nm) light-emitting diodes10 days before harvest in a greenhouse under ambient light conditions. Four blue-light treatments were conducted (0, 50,100, and 150 μmol m −2 s −1 , named T0, T50, T100, and T150, respectively) with 12 h (6:00–18:00) of light treatment perday. The growth of Chinese kale plants was improved by supplemental blue light. The fresh and dry weights of Chinesekale plants were signifi cantly higher under T50 and T100 than those in the other treatments. The content of chlorophyll band total chlorophyll increased signifi cantly under T50, and the content of carotenoids increased signifi cantly under T150. The contents of soluble sugars and free amino acids were signifi cantly increased under the blue light treatments. The nitratecontent decreased with increasing blue light intensity, while the anthocyanin content increased. The contents of vitamin Cin T50 and total phenolic compounds in T150 were signifi cantly higher than in T0. The fl avonoid contents were signifi canthigher in T50 and T150, and signifi cantly lower in T100. Our results show that blue light can infl uence the growth and qualityof Chinese kale and 50 μmol m −2 s −1 of supplemental blue light might be the most feasible light intensity for Chinesekale production.