Dielectric Spectra of BaTiO₃-Based Ceramics Measured by Impedance Analyzer Using Micro Planar Electrodes

Li, Jianyong,Kakemoto, Hirofumi,Wada, Satoshi,Tsurumi, Takaaki Trans Tech Publications, Ltd. 2006 Key Engineering Materials Vol.301 No.-

<P>A new measuring method and analyzing procedure were proposed to determine the complex dielectric permittivity of materials with relatively high permittivity using an RF-impedance analyzer. Samples used for the measurement were (Ba0.6Sr0.4)TiO3 and Ba(Zr0.25Ti0.75)O3 ceramics. Micro planar electrodes were used for the measurement of complex admittance of these samples. Electromagnetic simulations were carried out for determining the relative dielectric permittivity and dielectric loss. The complex dielectric permittivity vs. frequency curves of Ba(Zr0.25Ti0.75)O3 showed a broad dielectric relaxation, while that of (Ba0.6Sr0.4)TiO3 was almost flat up to 3 GHz.</P>

Increased Progastrin-Releasing Peptide Expression is Associated with Progression in Gastric Cancer Patients

Li Li,Xiaodong Yin,Hai Meng,Juanyu Hu,Zhengqing Yu,Jianyong Xu 연세대학교의과대학 2020 Yonsei medical journal Vol.61 No.1

Purpose: The purpose of this study was to assess the diagnostic and prognostic value of serum progastrin-releasing peptide(ProGRP) in patients with gastric cancer (GC). Materials and Methods: A total of 150 patients with GC (89 males and 61 females) were recruited, including those with stage I(n=28), stage II (n=33), stage III (n=50), and stage IV (n=39) disease; 50 healthy controls and 66 patients with benign gastric diseaseswere also enrolled. Levels of serum ProGRP, carcinoembryonic antigen (CEA), and carbohydrate antigen 72-4 (CA72-4)were measured in all subjects. Results: Serum ProGRP levels were significantly higher in GC patients than in controls (p<0.001), and ProGRP was significantlycorrelated with tumor size, tumor node metastasis stage, differentiation, invasion depth, and lymph node metastasis (p< 0.005). ProGRP levels were significantly decreased after chemotherapy (p<0.001). Receiver operating characteristic curves revealed a sensitivityand specificity for serum ProGRP in GC of 85.9% and 81.2%, respectively. ProGRP levels were positively correlated withCA72-4 and CEA (r=0.792 and 0.688, p<0.05, respectively). Combined detection of ProGRP, CEA, and CA72-4 showed the best diagnosticpower for GC. Conclusion: ProGRP may be useful as a potential biomarker for GC diagnosis and therapy.

Dielectric relaxation in gigahertz region and phase transition of BaTiO3-based ceramics

Li, Jianyong,Kakemoto, Hirofumi,Wada, Satoshi,Tsurumi, Takaaki,Kawaji, Hitoshi American Institute of Physics 2006 JOURNAL OF APPLIED PHYSICS - Vol.100 No.2

A new terpene coumarin microbial transformed by Mucor polymorphosporus induces apoptosis of human gastric cancer cell line MGC-803

Guangzhi Li,Junchi Wang,Xiaojin Li,Jianguo Xu,Zhao Zhang,Jianyong Si 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.6

20-Z auraptene (1) is a synthesized monoterpenecoumarin with anticancer activity against human gastriccancer cells. In order to find new potential anticancer agent,Mucor polymorphosporus was used to transform cis-auraptene. Four new terpene coumarins with notable changesin the skeletal backbone, 20-Z auraptene A-D (2–5), wereobtained and evaluated for their antiproliferative effectsagainst human normal gastric epithelium cells and humangastric cancer cells. These new compounds showed selectivecytotoxic activity against MGC-803 cells with IC50values from 0.78 ± 0.13 to 10.78 ± 1.83 lM and thetherapeutic index could also be significantly improved(TI = 59.0) compared with that of 1 (TI = 5.5). Thestructures of these metabolites were elucidated throughextensive spectroscopic methods, and the possible biotransformationpathway of 1 by Mucor polymorphosporuswas also proposed. Furthermore, the mechanism of theantiproliferative effects against MGC-803 cells of the mostpotent compound, 20-Z auraptene A (2), was characterized. Annexin V/PI staining and abnormal expression of apoptosis-related protein suggested that compound 2 inducesapoptosis in gastric cancer MGC-803 cells. Therefore, it ispossible that compound 2 has the potential to be applied ingastric cancer therapy.

In uence of In dopant on PL Spectra of CdZnTe Crystals

Jianyong Teng,Wenbin Sang,Gang Li,Zhubin Shi,Jiahua Min,Dongni Hu,Yongbiao Qian 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.1

Photoluminescence (PL) spectra are used to characterize the high resistivity of an In-doped CdZnTe (CZT) crystal. The features of the PL spectra vary with changing In-dopant concentration, indicating that the In-dopant concentration has a great impact on the defect type and density and on the extent of compensation in the In-doped CZT crystal. With the addition of In donors, a new sharp neutral donor bound exciton [D0, X] peak at 1.65 eV, corresponding to In substituting defect (In+ Cd) and a new defect complex band centered at 1.505 eV, related to the singly negative complex (VCd-InCd)- are observed. Meanwhile, the intensity and position of the feature peaks in PL spectra vary with the change of the In dopant concentration, representing the changes of the defect type and density and the extent of compensation in the crystal. It conrms that the Cd vacancy or residual impurity acceptors are dominantly compensated by In donors. The measured conduction type and carrier densities are the results of compensation between Cd vacancies and In donors and Te antisites, which are related to the In-dopant concentration and the stoichiometry for the CZT crystal. Photoluminescence (PL) spectra are used to characterize the high resistivity of an In-doped CdZnTe (CZT) crystal. The features of the PL spectra vary with changing In-dopant concentration, indicating that the In-dopant concentration has a great impact on the defect type and density and on the extent of compensation in the In-doped CZT crystal. With the addition of In donors, a new sharp neutral donor bound exciton [D0, X] peak at 1.65 eV, corresponding to In substituting defect (In+ Cd) and a new defect complex band centered at 1.505 eV, related to the singly negative complex (VCd-InCd)- are observed. Meanwhile, the intensity and position of the feature peaks in PL spectra vary with the change of the In dopant concentration, representing the changes of the defect type and density and the extent of compensation in the crystal. It conrms that the Cd vacancy or residual impurity acceptors are dominantly compensated by In donors. The measured conduction type and carrier densities are the results of compensation between Cd vacancies and In donors and Te antisites, which are related to the In-dopant concentration and the stoichiometry for the CZT crystal.

A Feeder Impedance Identification Based Droop Control Method for Accurate Reactive Power Sharing in Islanded Microgrids

Jianyong Zhao,Jian Li,Heng Nian,Lei Yang,Bao Gai,Zaiping Pan,Yourui Xu 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Due to the unmatched feeder impedance, the conventional voltage and frequency droop control method is unable to accurately allocate the output reactive power of DG units in proportion to their power ratings. To solve this issue, this paper has proposed a feeder impedance identification based droop control method. Firstly, the relationship among the reactive power sharing, reactive power droop slope and feeder impedance in islanded microgrids is illustrated. An online feeder impedance identification method is subsequently adopted to modify the reactive power droop slope of DG unit. In this way, the effect of unmatched feeder impedance on reactive power sharing is eliminated without communication among DG units. Experimental results implemented on an islanded microgrid apparatus have validated the feasibility of the proposed droop control method.

DEVELOPMENT OF A COMPOUND POWER-SPLIT HYBRID POWER SYSTEM FOR COMMERCIAL VEHICLES

Qing Li,Zhendong Zhang,Jianyong Bai,Tong Zhang,Fuxiang Gai 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.1

A novel compound power-split hybrid power system based on two planetary gear sets for commercial vehicles is developed. The equivalent lever diagram is used to investigate the components speed and torque characteristics of the system, and then the system dynamic torque control and transmission efficiency are described in equations. Six types of operating modes which are divided into two pure electric modes and four hybrid modes are analyzed by the simplified combined lever diagrams, and their torque decoupling in form of formula is derived. The hybrid transmission (HT) external characteristic is analyzed simultaneously. A control strategy which implements the rule-based (RB) method for the system is depicted. To evaluate the performance of a hybrid vehicle equipped with this hybrid system, the vehicle control and physical models are developed. Then power performance and economic performance simulations are performed. Meanwhile, corresponding tests are carried out to validate simulations. Simulation and test results indicate that, the fuel consumption for C-WTVC of the vehicle equipped with the proposed hybrid system is about 11 L/100 km and it declines by 21 % compared with 14 L/100 km of the traditional vehicle.

Experimental Study on the Pipe-Soil Interface under the Influence of Pipe Jacking Stagnation Time

Tianliang Li,Wen Zhao,Run Liu,Jianyong Han,Cheng Cheng 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

In the process of long-distance and large-diameter pipe jacking, thixotropic mud is generally injected into the outer surface of the pipe wall to reduce the frictional resistance between the pipe and the soil. The process of pipe jacking may be stopped due to various reasons such as pipe rupture and equipment damage. When the pipe is restarted after being stopped for a period of time, the interface mechanical properties usually change substantially, resulting in a substantial increase in frictional resistance compared to before the stop. However, the mechanical properties and shear mechanism of the pipe-soil interface after jacking is restarted have not been sufficiently investigated. In this paper, a series of gravelly sand-concrete direct shear tests are carried out, in which lubricant is injected into the interface between gravelly sand and concrete, and the effect of construction stagnation time is considered. The mechanical properties of the interface when the concrete pipe is restarted after stagnation is studied by the direct shear tests. The results show that the friction coefficient of pipe-soil interface increases with the stagnation time, which is determined by the thixotropic mud state and the content of gravelly sand involved in shear. In a short period of stagnation, the friction coefficient is determined by the cohesion caused by thixotropic mud and the friction angle produced by the gravelly sand involved in the shearing action. With the increase of stagnation time, the friction angle gradually becomes the decisive factor for the increase of friction coefficient.

Stress-strain Behaviour and Shear Strength of Municipal Solid Waste (MSW)

Xiulei Li,Jianyong Shi 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.5

An understanding of the stress-strain behaviour of Municipal Solid Waste (MSW) is important in landfill design and stability analysis of landfill slopes. A series of triaxial compression tests were carried out on reconstituted MSW specimens. The effect of stress path on the drained stress-strain response and shear strength of MSW were investigated. For the compression stress paths of Δσ3 ≥0, a straight-lined increase section and an upward curvature are observed in the stress-strain curves of MSW; the upward curvature results from the fibrous constituents (primarily plastic and paper) reinforcing the waste matrix; the hardening points defined in stress-strain curves are used as failure criterion to calculate the strength parameters of MSW. For the compression stress paths of Δσ3 < 0, the stress-strain responses of MSW exhibit a rapidly increasing section towards a slowly increasing section without upward curvature; the development of fibrous reinforcement is not enough due to the reduction of confining stress σ3; the failure points defined in stress-strain curves are also used as failure criterion to calculate the strength parameters of MSW. A new method to estimate MSW strength parameters is proposed in this study. The differences of MSW friction angle are very small for different stress path tests. However, the cohesions obtained in compression stress path tests of Δσ3 < 0 are much smaller than that in conventional triaxial compression tests.

Grinding Motor Energy Saving Method based on Material Removal Model in Rail Grinding Processes

Shaodan Zhi,Jianyong Li,Allan M. Zarembski 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.2 No.1

Railway is an environmental friendly method which has been widely used in the land transportation driven by electric powers, without harmful emissions and unhoped traffic jams. And it is important to guarantee the running safety through the technology of rail grinding. However, the empirical processes have limitations on the expanded requirements of frequent and systematic rail grinding. Therefore, it is necessary to build up the rail grinding model to fill the gap between the operating parameters and desired on-the-ground results. In this paper, a three-dimensional distribution model has been built to get a uniform special-distribution for grains and extract one slice as the representative grinding surface, with decahedrons grains transformed from spheres. Then the cutting force model and then related power model have been achieved based on the formed grinding surface with information of grains geometry and their locations. Calculation results show that the consumed power or the consumed energy have a close relationship with grinding speeds and grinding forces, which are closely related to the grain geometry, involved grain numbers, location of grains and their cutting depth. And it comes to a conclusion that a judgment for energy-saved grinding strategy depends on the grinding aims.