TiO2 Nanotubes/Nanoparticles Composite Film with Higher Light Harvesting and Electron Transfer for Dye-Sensitized Solar Cells

Chengcheng Liu,Zhifeng Liu,Lei E,Yabin Li,Jianhua Han,Yun Wang,Zhichao Liu,Jing Ya,Xuhuang Chen 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.5

TiO2 nanotubes with an inner diameter of 4-6 nm were synthesized by hydrothermal treatment method. TiO2nanotubes/nanoparticles composite films were fabricated as a dye-sensitized solar cells work electrode using TiO2 nanotubes and TiO2 nanoparticles as precursor. The structure of composite films has a remarkable influence on the final performance of the cell due to high surface area, fast electron transfer, enhanced light-scattering and light-harvesting, simultaneously. I-V characteristic measurement indicates an enhanced efficiency by 27%as compared to TiO2 nanotubes film.

Multiphysical Design and Optimization of High-Speed Permanent Magnet Synchronous Motor with Sinusoidal Segmented Permanent Magnet Structure

Liu Chengcheng,Zhang Hongming,Wang Shaoheng,Wang Youhua,Lei Gang,Zhu Jianguo 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

High speed permanent magnet synchronous motor (HSPMSM) is an important driving motor for electric vehicles. Compared with the electric motor operated under normal speed, it is critical to reduce the torque ripple, vibration, and noise of the HSPMSM. Furthermore, The air-gap fux density total harmonic distortion and electromotive force total harmonic distortion determine by torque performance and vibration noise. This article uses analytical methods to analyze the infuence of permanent magnet sinusoidal segmentation (PMS) on the electromagnetic performance of surface-mounted HSPMSM. The fnite element method is used to calculate the infuence of diferent permanent magnet segmentation numbers, diferent adjacent permanent magnet decreasing thickness, and diferent center PM width on the electromagnetic performance of permanent magnet sinusoidal segmented surface-mounted high-speed permanent magnet synchronous motor (M2). Comparing the efectiveness of PMS in surface-mounted HSPMSM and interior HSPMSM. Furthermore, the rotor dynamics analysis and vibration noise analysis on M2 are performed, and the infuence of PMS on the stress and vibration noise of both motors’ rotors is summarized. This article proposes a parameter preprocessing grouping multiphysical multi-objective high-dimensional multilevel optimization method. Taking M2 as an example, a global optimization design was carried out for the high-dimensional structural parameters brought by PMS, which improved the electromagnetic performance of M2 and reduced the vibration noise and rotor stress.

Development of a Crash Risk Index to Identify Real Time Crash Risks on Freeways

Chengcheng Xu,Pan Liu,Wei Wang,Xuan Jiang 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.7

The primary objective of this study is to develop a quantitative indicator that can be directly used to identify hazardous traffic states on freeway mainlines. Using data obtained from a 22-mile freeway segment on the I-880N freeway in San Francisco Bay Area in the United States, Fisher discriminant analysis was conducted to derive a linear combination of traffic flow parameters which can be used to distinguish traffic states which may lead to crashes from normal traffic conditions which were potentially safe. A new variable termed “crash risk index” was defined based on the discriminant function. A crash risk index which is smaller than 0 represents a hazardous traffic condition potentially leading to a crash. Accordingly, a crash risk index which is greater than 0 represents normal traffic conditions which, theoretically, will not lead to crash occurrences. The research team tested the prediction performance of using the crash risk index to identify hazardous traffic conditions on freeway mainlines. An overall prediction accuracy of about 65.7% was achieved. Conditional logistic regression analysis was then conducted to evaluate the impacts of crash risk indexes on the likelihood of crash occurrences. It was found that the likelihood of freeway crashes increased with the decreases in crash risk index. One unit decrease in crash risk index increased the risk of crash occurrence by 180.3%. The research team also looked extensively at the impacts of crash risk indexes at different time slices. It was found that the impacts of crash risk index decrease with time and the crash risk index at the time slice most immediately before crashes had the greatest impact on crash occurrences.

Utilizing Structural Equation Modeling and Segmentation Analysis in Real-time Crash Risk Assessment on Freeways

Chengcheng Xu,Dawei Li,Zhibin Li,Wei Wang,Pan Liu 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.7

The study aimed to utilize Structural Equation Modeling (SEM) and K-means clustering for predicting real-time crash risks onfreeways. The SEM was used to transform a number of correlated traffic variables into four independent latent traffic factors, and toestablish the interrelationships among the traffic variables and crash risks. The segmentation analysis based on K-means clusteringwas then conducted to investigate the main traffic factors affecting crash risks in various traffic regimes. It was found that: (a) Themeasurement equations in SEM can effectively account for the correlations among traffic variables by transforming numerouscorrelated traffic variables into several latent traffic variables; (b) The SEM can both capture the direct and indirect effects of trafficflow variables on crash risks. This promotes a better understanding how traffic conditions affect crash risks; (c) The SEM producesmore accurate estimates of crash risks than existing modeling technique. It can increase the crash prediction accuracy by an averageof 7.6% compared with the commonly used logistic regression; and (d) Segmentation analysis results suggested that the trafficfactors contributing to crash risks are various across different traffic regimes. The proactive crash prevention strategies for differenttraffic regimes were discussed based on the findings in the segmentation analysis

Constraining top partner and naturalness at the LHC and TLEP

Han, Chengcheng,Kobakhidze, Archil,Liu, Ning,Wu, Lei,Yang, Bingfang Elsevier 2015 Nuclear Physics, Section B Vol.890 No.-

<P><B>Abstract</B></P> <P>We investigate indirect constraints on the top partner within the minimal fermionic top partner model. By performing a global fit of the latest Higgs data, <SUB> B s </SUB> → <SUP> μ + </SUP> <SUP> μ − </SUP> measurements and the electroweak precision observables we find that the top partner with the mass up to 830 GeV is excluded at 2<I>σ</I> level. Our bound on the top partner mass is much stronger than the bounds obtained from the direct searches at the LHC. Under the current constraints the fine-tuning measure is less than 9% and the branching ratio of T → t Z is bounded between 14% and 25%. We also find that precise measurements of Higgs couplings at 240 GeV TLEP will constrain the top partner mass in multi-TeV region.</P>

Clinicopathological Analysis and Treatment of Adult Patients with Inflammatory Myofibroblastic Tumor: A 15-Year Single- Center Study

Xin Liu,Chengcheng Gong,Jieyun Zhang,Wanjing Feng,Yanjing Guo,Youzhou Sang,Chunmeng Wang,Yong Chen,Jian Wang,Lin Yu,Xiaowei Zhang,Zhiguo Luo 대한암학회 2023 Cancer Research and Treatment Vol.55 No.3

Purpose Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal malignancy that occurs primarily in children and adolescents. The clinical and pathological features of IMT in adult patients are not well understood.Materials and Methods We retrospectively searched for records of adult patients with IMT at Fudan University Shanghai Cancer Center from 2006 to 2021. Clinicopathological data, treatments, and outcomes were collected and analyzed.Results Thirty adult patients with IMT, mostly women (60.0%), were included. The median age of the patients was 38 (21-77). The most common primary site was abdominopelvic region (53.3%), followed by lungs (20.0%). Seven patients had an abdominal epithelioid inflammatory myofibroblast sarcoma (EIMS). The positivity rate of anaplastic lymphoma kinase (ALK) was 81.5% (22/27). Sixteen patients with advanced ALK-positive disease received crizotinib, with an objective response rate (ORR) of 81.3% and a disease control rate of 87.5%. The median progression-free survival was 20.8 months. EIMS was associated with more aggressive behavior; however, the prognosis was similar to that of non-EIMS patients after treatment with an ALK inhibitor. At a median follow-up time of 30 months (95% confidence interval [CI], 13.6 to 46.4), the 5-year overall survival was 77% (95% CI, 66 to 88) in all patients.Conclusion Adult IMTs appeared more aggressive, with a higher incidence of recurrence and metastases, and patients with EIMS had more aggressive cases. Treatment with ALK inhibitors resulted in a high ORR and a durable response, which suggested that ALK inhibitors could be used as a first-line treatment option in adult patients with ALK-positive advanced IMT.

Aloe-Emodin-Mediated Photodynamic Therapy Attenuates Sepsis-Associated Toxins in Selected Gram-Positive Bacteria In Vitro

( Woodvine Otieno ),( Chengcheng Liu ),( Yanhong Ji ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.9

Sepsis is an acute inflammatory response that leads to life-threatening complications if not quickly and adequately treated. Cytolysin, hemolysin, and pneumolysin are toxins produced by grampositive bacteria and are responsible for resistance to antimicrobial drugs, cause virulence and lead to sepsis. This work assessed the effects of aloe-emodin (AE) and photodynamic therapy (PDT) on sepsis-associated gram-positive bacterial toxins. Standard and antibiotic-resistant Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pneumonia bacterial strains were cultured in the dark with varying AE concentrations and later irradiated with 72 J/cm-2 light. Colony and biofilm formation was determined. CCK-8, Griess reagent reaction, and ELISA assays were done on bacteriainfected RAW264.7 cells to determine the cell viability, NO, and IL-1β and IL-6 pro-inflammatory cytokines responses, respectively. Hemolysis and western blot assays were done to determine the effect of treatment on hemolysis activity and sepsis-associated toxins expressions. AE-mediated PDT reduced bacterial survival in a dose-dependent manner with 32 μg/ml of AE almost eliminating their survival. Cell proliferation, NO, IL-1β, and IL-6 cytokines production were also significantly downregulated. Further, the hemolytic activities and expressions of cytolysin, hemolysin, and pneumolysin were significantly reduced following AE-mediated PDT. In conclusion, combined use of AE and light (435 ± 10 nm) inactivates MRSA, S. aureus (ATCC 29213), S. pneumoniae (ATCC 49619), MDR-S. pneumoniae, E. faecalis (ATCC 29212), and VRE (ATCC 51299) in an AE-dose dependent manner. AE and light are also effective in reducing biofilm formations, suppressing proinflammatory cytokines, hemolytic activities, and inhibiting the expressions of toxins that cause sepsis.

Computational investigation of three-faced blade errors on contact behaviors for face-hobbed hypoid gears

Chaosheng Song,Chengcheng Liang,Caichao Zhu,Kunming Liu,Siyuan Liu,Qianhong Huang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7

An accurate mathematical model of face-hobbed hypoid gear tooth surface based on the three-faced blade is established. The correctness of the mathematical model was verified by comparing the contact pattern results from KIMOS software and finite element tooth contact analysis. Then, the effects of tool errors on mesh characteristics of face-hobbed hypoid gear were investigated by loaded tooth contact analysis. Results show that the influences of pressure angle error and regrind angle error on contact pattern are obvious. The location of contact pattern moves from the root on the heel side to the top on the toe side of the tooth surface when the error value increases. The peak-to-peak value of transmission error gradually increases with those two types of errors. The influences of spheric radius error, rake angle error and cutting side relief angle error on contact behaviors are similar and not obvious for facehobbed hypoid gears.

Analysis and Design Optimization of Axial–Radial Flux Hybrid Excitation Permanent Magnet Eddy Current Coupling

Zhang Hongming,Liu Chengcheng,Zhang Shiwei,Wang Youhua,Lei Gang,Zhu Jianguo 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.6

This paper proposes an axial–radial flux hybrid excitation permanent magnet eddy current coupling (HE-PMEC), where the ferrite magnet is employed for producing the radial flux and the DC excitation current is adopted for producing the axial flux. Moreover, a shielding layer is developed to regulate the radial magnetic field. Its magnetic field distribution, electromagnetic performance, and temperature distribution are calculated based on the 3D finite element method (FEM). By adjusting the applied DC excitation current density and the insertion depth of the shielding layer, the variable current starting process, the variable current braking process, and the speed regulation characteristic of the proposed HE-PMEC are obtained. It can be seen that the starting process, braking process, and speed regulation ability of the HE-PMEC have been enhanced greatly. Furthermore, the copper ring shape of the HE-PMEC is optimized by using the proposed improved multilevel optimization method. It can be seen that the performance of the HE-PMEC can be improved by using the new optimized copper ring shape. Lastly, compared with the conventional PMECs, the proposed HE-PMEC has shown its superior electromagnetic performance.

Preparation of Well-Dispersed Nanosilver in MIL-101(Cr) Using Double-Solvent Radiation Method for Catalysis

SHUQUAN CHANG,Chengcheng Liu,Heliang Fu,Zheng Li,Xian Wu,Jundong Feng,Haiqian Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12

In this study, a double-solvent radiation method is proposed to prepare silver nanoparticles in the pores of metal-organic framework MIL-101(Cr). The results reveal that well-dispersed silver nanoparticles with a diameter of about 2 nm were successfully fabricated in the cages of monodisperse octahedral MIL-101(Cr) with a particle size of about 400 nm. The structure of MIL-101(Cr) was not destroyed during the chemical treatment and irradiation. The resulting Ag/MIL-101 exhibits excellent catalytic performance for the reduction of 4-nitrophenol. This method can be extended to prepare other single or bimetallic components inside porous materials.