Hydrothermal Synthesis of Hierarchical Hollow Li(Ni0.8Co0.15Al0.05)O2 Microspheres for Lithium Ion Batteries

Liu Wenlong,Jiang Weiwei,Yan Chenran,Feng Wei,Wang Dongxia,Zhao Liming,Feng Tingting,Gong Feng 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.11

Li(Ni0.8Co0.15Al0.05)O2 (NCA) cathode material for lithium ion batteries is synthesized by calcining Ni–Co–Al hydroxide or carbonate hydroxide hydrate precursor, which is obtained by hydrothermal method, and the NCA cathode material is hierarchical hollow microspheres with the diameter in the range of 3–5 µm and composed of nanoflakes and/or nanowires. The effect of hydrothermal reaction time on the morphologies and the crystalline quality of the NCA cathode material is investigated on the basis of scanning electron microscopy, X-ray diffraction, and tunneling electron microscopy. The NCA cathode material shows smooth and monotonous charge/discharge characteristics, delivers a reversible capacity as 144.4 mAh/g and retains 90.4% after 50 cycles at a current density of 0.1 C between 2.5 and 4.3 V.

그린마케팅활동과 브랜드 글로벌성 및 환경행동의 관계구조 탐색과 제언

유문용(Wenlong Liu),장형유(Hyeongyu Jang) 동국대학교 경영연구원 2020 경영과 사례연구 Vol.42 No.2

본 연구에서는 그린마케팅활동을 체계화 하고 이 같은 활동이 소비자의 지각 된 브랜드 글로벌성과 어떠한 관계를 가지는지를 탐색한다. 그린마케팅활동 정도를 여러 국가로 나누어 사례분석하고, 이 활동이 여러 마케팅활동에 어떠한 영향을 미치는지를 탐색하였다. 특히, 그린마케팅활동이 지각된 브랜드 글로벌성으로 이어지는 과정에서 환경인식이나 환경행동이 주요한 조절역할을 한다는 사실을 문헌연구를 통해서 도출한 후, 실무적 활용가능성을 높임과 동시에 연구의 차별성을 확보하였다. This study is to organize the green marketing activities of companies and to explore how these activities have a relationship with the perceived brand globality of consumers. The degree of green marketing activities was divided into Europe, the United States, Japan, China, and Korea, and a case analysis was conducted and theoretically examined how these activities influenced various marketing activities. In particular, in the process of green marketing activities leading to perceived brand globality, environmental awareness or environmental action plays a major regulatory role. Practical practical applicability has been improved through literature research, while at the same time securing research discrimination. If the existing marketing mix is converted into a green activity and the consumer s perceived brand globality is strengthened based on environmental awareness, it can greatly contribute to strengthening brand trust and brand loyalty.

A Fractal-Interpolation Model for Diagnosing Spalling Risk in Concrete at Elevated Temperatures

Caiwei Liu,Chaofeng Liu,Wenlong Xu,Xiaobo Zhang,Yue Lan 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.12

Spalling risk analysis and assessment of fire-loaded concrete structures is an essential part of research on fire-resistant behavior of concrete structures. In this work, the authors developed a stochastic interpolation-based fractal model capable of quickly assessing spalling risk in concrete at high temperatures based on mainly factors affecting explosive spalling. The preliminary grading standard of the factors elected in the study was established based on the data from literature. Test samples were then generated by the stochastic interpolation method according to uniform distribution. A spalling risk diagnosis model was built based on fractal dimension weights. In addition, 10 specimens were assessed with the presented model. The evaluation results obtained by the model in this study were in good agreement with those obtained by the fuzzy pattern recognition approach and coincided well with the actual fire test results. The applicability and reliability of the proposed model were verified and can provide theoretical support for identification of the spalling risk of concrete at elevated temperatures.

Surfactant-free synthesis of CuBr NPs decorated by Pt for glucose and nitrite sensors

Xinmei Liu,Xue Zhou,Chunyang Yang,Wenlong Yang,Gang Liu,Yuhang Li,Guangyu Zhang,Xu Zhao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

The high cost and narrow detection range of electrocatalyst are the two major challenges for the electrochemicalbiosensors. This work provided a surfactant-free synthesis of CuBr@Pt nanoparticles (CuBr@PtNPs) with controllable Pt loading rates. The introduction of chloroplatinic acid (H2PtCl6) and an elevatedsynthesis temperature resulted in a high surface area for CuBr@Pt NPs. The abundant active sites enabledthe CuBr@Pt NPs a superior performance as applied in glucose and nitrite detection. Moreover, an optimalPt loading would be conducive to optimize sensor performances of CuBr@Pt NPs. In the glucose detection,the sensor by CuBr@Pt-15% could reach the detection concentration up to 68.0 mM, which was 1.9 timeshigher than that by pure CuBr. And the corresponding sensitivity by CuBr@Pt-15% was calculated to be382.73 lA/mMcm2. In the detection of sodium nitrite, CuBr@Pt-15% also revealed a superior behaviorthan previous work. And the detection concentration (by the linear sweep voltammetry) was form 0 to80.0 mM. This work demonstrated the superior biosensor performance of CuBr@Pt-15%, which offereda promising material for sensor with wider detection range and rationalized cost.

Fire Damage Identification in RC Beams based on Support Vector Machines considering Vibration Test

Chaofeng Liu,Caiwei Liu,Chengxin Liu,Xuhong Huang,Jijun Miao,Wenlong Xu 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.10

In order to obtain the degree of damage in reinforced concrete (RC) beams exposed to fire, using the equivalent fire exposure time as the damage index, a new method of damage identification based on the support vector machine technology was proposed. Firstly, the feasibility analysis was conducted based on finite element models of simply supported beams. Thereafter, four RC simply supported beams were designed for fire test and vibration test, which were used to amend the finite element model and the SVM-based identification method. Fire tests were carried out on 4 beams for 60, 90, 120, and 150 min, respectively. During and after the fire tests, structural modal information were recorded. The first two order modal information, as SVM input paraments, was used to predict the equivalent fire exposure time based on SVM. The predicted results were very close to the actual fire exposure time. The residual bearing capacities of the beams after fire were calculated according to the predicted fire exposure time, which were close to experimental results. It indicated that the equivalent fire exposure time as the output parameter for damage identification was reliable. Finally, on the basis of damage identification method for simply supported beams, a new three-step positioning method was established for identifing the degree of damage in continuous beams. The method was applied to a thress-span continuous beam. The numercial situlation results revealed that the three-step positioning method was accurate.

Anti‑misalignment capability optimization for laminated magnetic couplers in wireless charging systems using balanced particle swarm optimization method

Hao Liu,Zhenjie Li,Yuhong Tian,Yiqi Liu,Wenlong Song 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.2

To desensitize wireless charging systems (WCSs) to misalignment and to achieve a stable output voltage without using additional control methods, a laminated magnetic coupler (LMC) optimized by the balanced particle swarm optimization (BPSO) method is proposed to improve the performance of WCSs. First, the output characteristics of the LCC-S compensated WCS are analyzed to illustrate the working principle of the LMC. Next, the misalignment characteristics of the LMC, which employs the magnetic integration technique and coil self-decoupling method, are analyzed. Then, the operating principle of the BPSO method is analyzed and used to optimize the LMC in terms of the mutual inductance and anti-misalignment range. Finally, experimental results indicate that the optimized LMC achieves high-efficiency constant voltage charging within a reasonable horizontal misalignment range. When compared to commonly used methods (such as the exhaustive method) for optimizing magnetic couplers, the BPSO method avoids complex algorithms and a heavy computation burden.

Probabilistic Risk Assessment of RCC Dam Considering Grey-Stochastic-Fuzzy Uncertainty

Wenlong Chen,Xiaoling Wang,Minghui Liu,Yushan Zhu,Shaohui Deng 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

Greyness, randomness and fuzziness are three inseparable uncertainty factors influencing the safety of a roller compacted concrete dam (RCC dam), which can be regarded as a system reliability problem associated with multiple failure modes. Aiming at the current probabilistic risk analysis of RCC dams, most of the studies limited to single failure mode and single uncertainty. A probabilistic risk assessment method for dam under Grey-Stochastic-Fuzzy (GSF) uncertainty is proposed to consider the randomness and greyness of parameters and the fuzziness of the failure criteria. First, the fault tree model of an RCC dam is established based on Fault Tree Analysis (FTA). Then, bootstrap repeated sampling is embedded into grey system theory to quantify the grey properties of stochastic variables. The Latin Hypercube Sampling (LHS) function is improved to compensate for the inability of describing the fuzzy failure criteria. Finally, considering the correlated multiple failure modes, the proposed method is applied to analyze the parameter sensitivity and failure probability of the LDL dam in China. The results show that the proposed method is a high-efficiency, fastconvergence and more scientific method with reasonable outputs compared to common uncertainty probability analysis methods. The proposed method also provides an effective basis for the structural design and safety analysis of a concrete dam.

Municipal Solid Waste Treatment and Mitigation of Greenhouse Gas in China

( Wenlong Xu ),( Jinghao Liu ) 한국폐기물자원순환학회 2010 APLAS Vol.2010 No.0

A Decentralized Optimal Load Current Sharing Method for Power Line Loss Minimization in MT-HVDC Systems

Liu, Yiqi,Song, Wenlong,Li, Ningning,Bai, Linquan,Ji, Yanchao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

This paper discusses the elimination of DC voltage deviation and the enhancement of load current sharing accuracy in multi-terminal high voltage direct current (MT-HVDC) systems. In order to minimize the power line losses in different parallel network topologies and to insure the stable operation of systems, a decentralized control method based on a modified droop control is presented in this paper. Averaging the DC output voltage and averaging the output current of two neighboring converters are employed to reduce the congestion of the communication network in a control system, and the decentralized control method is implemented. By minimizing the power loss of the cable, the optimal load current sharing proportion is derived in order to achieve rational current sharing among different converters. The validity of the proposed method using a low bandwidth communication (LBC) network for different topologies is verified. The influence of the parameters of the power cable on the control system stability is analyzed in detail. Finally, transient response simulations and experiments are performed to demonstrate the feasibility of the proposed control strategy for a MT-HVDC system.

Betulinic Acid Induces Bax/Bak-Independent Cytochrome c Release in Human Nasopharyngeal Carcinoma Cells

Yang Liu,Wenlong Luo 한국분자세포생물학회 2012 Molecules and cells Vol.33 No.5

Betulinic acid (BetA) is an effective and potential anti-cancer chemical derived from plants. BetA can kill a broad range of tumor cell lines, but has no effect on untransformed cells. The chemical also kills melanoma, leukemia, lung, colon, breast, prostate and ovarian cancer cells via induction of apoptosis, which depends on caspase activation. However, no reports are yet available about the effects of BetA on nasopharyngeal carcinoma (NPC), a widely spread malignancy in the world, especially in East Asia. In this study, we first showed that BetA can effectively kill CNE2 cells, a cell line derived from NPC. BetA-induced CNE2 apoptosis was characterized by typical apoptosis hallmarks: caspase activation, DNA fragmentation, and cytochrome c release. Overexpression of Bcl-2 and Bcl-xL could partially prevent apoptosis caused by BetA. Moreover, Bax was not activated during the induction of apoptosis. Bax/Bak knockdown and wild-type CNE2 cells showed the same kinetics of cytochrome c release. We then showed that BetA may impair mitochondrial permeability transition pores (mPTPs), which may partially contribute to cytochrome c release. These observations suggest that BetA may serve as a potent and effective anti-cancer agent in NPC treatment. Further exploration of the mechanism of action of BetA could yield novel break-throughs in anti-cancer drug discovery.