In Situ Synthesis of Highly Dispersed Silver Nanoparticles on Multiwalled Carbon

Xianming Hou,Lixia Wang,Rentao Wu 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.8

Selective purification of multiwalled carbon nanotubes by dielectrophoresis within a large array

Xianming Liu,John L. Spencer,Alan B. Kaiser,W. Mike Arnold 한국물리학회 2006 Current Applied Physics Vol.6 No.3

A prototype device was made to scale up a method for the wet purication of multiwalled carbon nanotubes (MWCNTs). The deviceconsists of a uid-ow chamber, which facilitates the ow of MWCNT suspensions across a large array of interdigitated electrodes(IDEs). A radio-frequency voltage provides the electric eld for dielectrophoresis. Electric parameters of the array were monitored dur-ing the running of the process and were observed to reect the increase of conductance caused by accumulation of MWCNTs. SEM andRaman spectroscopy showed a decrease in the D-band to G-band ratio for the material accumulated on the array.

Sensorless control of printed permanent magnet synchronous motor

Xianming Deng,Maolin Li,Min Xu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.1

As a special disc motor, a printed permanent magnet synchronous motor (PMSM) uses a PCB printed board as the stator, which has the advantages of simple assembly, short axial distance, no stator slot, low eddy current loss, etc. Due to the stator-less core structure and the small number of winding turns, the inductance of the motor is very small. When vector control technology is used to drive the motor, the motor current pulse vibration is intense, there is a large number of integer multiples of the switching frequency high-frequency harmonics, there is also torque output pulse vibration, and it cannot be sampled to obtain the actual working state of the motor stator current, which affects the sliding mode sensorless control algorithm in terms of stator current estimation. Then it affects the motor speed and position estimation. In this paper, a solution involving high switching frequency control is proposed to obtain the characteristics of this kind of motor. In addition, the sensorless control of the motor based on the super-twisting sliding mode is realized. Simulation and experiments show the stability and effectiveness of the motor position free control system, and solve the problems related to severe motor stator current oscillation, motor output electromagnetic torque oscillation, and poor control performance of the sensorless algorithm caused by a small motor stator inductance.

Sensitivity analysis of rolling bearing fatigue life under cyclic loading

Xianming Wang,Qingling Meng,Tianxiao Zhang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

Rolling bearings are regularly subjected to cyclic loading, and the load changing sequence has a significant influence on bearing fatigue life. The study offers a cumulative fatigue damage theory based on the improved Lundberg-Palmgren method that takes into account the effect of load changing sequence on bearing fatigue life and then proposes a modified Miner bearing fatigue life model. Additionally, the state function for the bearing fatigue life analysis is developed based on the basic dynamic load rating and stress-strength interference model of the bearing. A moment-based sensitivity analysis method for bearing fatigue life is proposed for studying the influence of different variables on bearing fatigue life. Finally, a sensitivity analysis of the fatigue life of 6209 deep groove ball bearings was performed as an example. The calculation results demonstrate that the modified Miner life model is comprehensive and that the moment-based sensitivity analysis method is simple and accurate.

A Solution to Privacy Preservation in Publishing Human Trajectories

( Xianming Li ),( Guangzhong Sun ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.8

With rapid development of ubiquitous computing and location-based services (LBSs), human trajectory data and associated activities are increasingly easily recorded. Inappropriately publishing trajectory data may leak users’ privacy. Therefore, we study publishing trajectory data while preserving privacy, denoted privacy-preserving activity trajectories publishing (PPATP). We propose S-PPATP to solve this problem. S-PPATP comprises three steps: modeling, algorithm design and algorithm adjustment. During modeling, two user models describe users’ behaviors: one based on a Markov chain and the other based on the hidden Markov model. We assume a potential adversary who intends to infer users’ privacy, defined as a set of sensitive information. An adversary model is then proposed to define the adversary’s background knowledge and inference method. Additionally, privacy requirements and a data quality metric are defined for assessment. During algorithm design, we propose two publishing algorithms corresponding to the user models and prove that both algorithms satisfy the privacy requirement. Then, we perform a comparative analysis on utility, efficiency and speedup techniques. Finally, we evaluate our algorithms through experiments on several datasets. The experiment results verify that our proposed algorithms preserve users’ privay. We also test utility and discuss the privacy-utility tradeoff that real-world data publishers may face.

New De-excitation Method for Large Hydraulic Generator

Chen, Xianming,Wang, Wei,Lu, Hongshui,Liu, Guohua,Zhu, Xiaodong The Korean Institute of Electrical Engineers 2011 The Journal of International Council on Electrical Vol.1 No.2

The requirement for arc voltage during the opening of a field breaker for large hydraulic generator increases when de-excitation (DE) is performed with a varistor parallel connected to field wingding. In fact, E.M.F of the field winding is required to be higher than the varistor threshold voltage during opening of field breaker. In this paper, the principle of DE with capacitors is introduced. The high voltage produced during DE by the R,L,C series oscillation is used to force the varistor into operation which decreases the opening arc voltage requirement of the field breaker. A simulation is completed to confirm the proper operation of the new DE approach.

Seasons affect the phosphorylation of pork sarcoplasmic proteins related to meat quality

Zeng Xianming,Li Xiao,Li Chunbao 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.1

Objective: Sarcoplasmic proteins include proteins that play critical roles in biological processes of living organisms. How seasons influence biological processes and meat quality of postmortem muscles through the regulation of protein phosphorylation remain to be investigated. In this study, the phosphorylation of sarcoplasmic proteins in pork longissimus muscle was investigated in four seasons. Methods: Sarcoplasmic proteins were extracted from 40 pork carcasses (10 for each season) and analyzed through ProQ Diamond staining for phosphorylation labeling and Sypro Ruby staining for total protein labeling. The pH of muscle, contents of glycogen and ATP were measured at 45 min, 3 h, and 9 h postmortem and the water (P2b, P21, and P22) was measured at 3 h and 9 h. Results: A total of 21 bands were detected. Band 8 (heat shock cognate 71 kDa protein; heat shock 70 kDa protein 1B) had higher phosphorylation level in summer than that in other seasons at 45 min postmortem. The phosphorylation levels of 3 Bands were significantly different between fast and normal pH decline groups (p<0.05). The phosphorylation levels of 4 bands showed negative associations with immobilized water (P21) and positive association with free water (P22). Conclusion: The phosphorylation levels of sarcoplasmic proteins involved in energy metabolism and heat stress response at early postmortem time differed depending on the seasons. These proteins include heat shock protein 70, pyruvate kinase, phosphoglucomutase-1, glucose-6-phosphate isomerase, and carbonic anhydrase 3. High temperatures in summer might result in the phosphorylation of those proteins, leading to pH decline and low water holding capacity. Objective: Sarcoplasmic proteins include proteins that play critical roles in biological processes of living organisms. How seasons influence biological processes and meat quality of postmortem muscles through the regulation of protein phosphorylation remain to be investigated. In this study, the phosphorylation of sarcoplasmic proteins in pork longissimus muscle was investigated in four seasons.Methods: Sarcoplasmic proteins were extracted from 40 pork carcasses (10 for each season) and analyzed through ProQ Diamond staining for phosphorylation labeling and Sypro Ruby staining for total protein labeling. The pH of muscle, contents of glycogen and ATP were measured at 45 min, 3 h, and 9 h postmortem and the water (P2b, P21, and P22) was measured at 3 h and 9 h.Results: A total of 21 bands were detected. Band 8 (heat shock cognate 71 kDa protein; heat shock 70 kDa protein 1B) had higher phosphorylation level in summer than that in other seasons at 45 min postmortem. The phosphorylation levels of 3 Bands were significantly different between fast and normal pH decline groups (p<0.05). The phosphorylation levels of 4 bands showed negative associations with immobilized water (P21) and positive association with free water (P22).Conclusion: The phosphorylation levels of sarcoplasmic proteins involved in energy metabolism and heat stress response at early postmortem time differed depending on the seasons. These proteins include heat shock protein 70, pyruvate kinase, phosphoglucomutase-1, glucose-6-phosphate isomerase, and carbonic anhydrase 3. High temperatures in summer might result in the phosphorylation of those proteins, leading to pH decline and low water holding capacity.

In Situ Synthesis of Highly Dispersed Silver Nanoparticles on Multiwalled Carbon

Hou, Xianming,Wang, Lixia,Wu, Rentao Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.8

Profile-based Roughness Discrimination with Pen-type Texture Sensor

Ye, Xianming,Choi, Bynng-June,Kang, Sung-Chul,Choi, Hyouk-Ryeol 제어로봇시스템학회 2010 Transaction on control, automation and systems eng Vol. No.

Tactile discriminations of surface roughness using artificial sensors have been challenging. The modeling methods and parameters that have been using to describe the mechanical properties of rough surface are insufficient for haptic roughness. This paper proposes a method to characterize surface roughness based on the profiles of the surface. A compact handheld pen-type texture sensor with a right probe is developed for the measurement of surface profiles. Based on the contact force and the motion of the senor, profiles in the paths of scanning are estimated. The height variations of a profile are converted to a series of tactile stimuli to represent the contact stimulations in haptic explorations. The mean and the standard deviation of the amplitudes of stimuli are identified as haptic features that indicate the required tangential force to slide on the rough surface and how rough the surface is, respectively. Experiments show that the roughness on four kinds of sandpapers can he clearly distinguished by the proposed discrimination method.

Expanding the Diversity of Allosteric Bcr-Abl Inhibitors

Deng, Xianming,Okram, Barun,Ding, Qiang,Zhang, Jianming,Choi, Yongmun,Adriá,n, Francisco J.,Wojciechowski, Amy,Zhang, Guobao,Che, Jianwei,Bursulaya, Badry,Cowan-Jacob, Sandra W.,Rummel, Gabriele American Chemical Society 2010 Journal of medicinal chemistry Vol.53 No.19

<P/><P>Inhibition of Bcr-Abl kinase activity by imatinib for the treatment of chronic myeloid leukemia (CML) currently serves as the paradigm for targeting dominant oncogenes with small molecules. We recently reported the discovery of GNF-2 (<B>1</B>) and GNF-5 (<B>2</B>) as selective non-ATP competitive inhibitors of cellular Bcr-Abl kinase activity that target the myristate binding site. Here, we used cell-based structure−activity relationships to guide the optimization and diversification of ligands that are capable of binding to the myristate binding site and rationalize the findings based upon an Abl−compound <B>1</B> cocrystal. We elucidate the structure−activity relationships required to obtain potent antiproliferative activity against Bcr-Abl transformed cells and report the discovery of new compounds (<B>5g</B>,<B> 5h</B>,<B> 6a</B>,<B> 14d</B>, and <B>21j-I)</B> that display improved potency or pharmacological properties. This work demonstrates that a variety of structures can effectively target the Bcr-Abl myristate binding site and provides new leads for developing drugs that can target this binding site.</P>