Novel P/N/Si/S-containing Mononickel Complex as a Metal-based Intumescent Flame Retardant for Cotton Fabrics

Meng-Yuan Hu,Kuan-Kuan Xiong,Jian-Rong Li,Xing-Bin Jing,Pei-Hua Zhao 한국섬유공학회 2019 Fibers and polymers Vol.20 No.9

A new P/N/Si/S-containing mononickel complex NiS, which can be regarded as a rare type of the metal-basedintumescent flame retardant, has been prepared through the condensation reaction of precursor NiCl with 1, 2-ethanedithiolin the presence of triethylamine as acid-binding agent. Its molecular structure is well characterized by elemental analysis,infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies. The target flame retardant NiS has been successfullyapplied to cotton fabrics through a pad-dry-cure method. Thermal degradation properties of neat and treated cotton fabricswith 10.7 wt% NiS are studied by thermogravimetric analysis (TGA). Flammability behaviors of neat and treated cotton with10.7 wt% NiS are evaluated using vertical burning test, limiting oxygen index (LOI) and microscale combustion calorimeter(MCC). Meanwhile, to further investigate the flame retardancy of NiS for cotton fabrics, the char layers of neat and treatedsamples after combustion are analyzed by SEM image and Raman spectroscopy. As a result, the improved thermal andflammability performance for cotton fabrics by introduction of NiS might be due to the metal-assisted catalytic charringeffect of NiS on the formation of the compact char layer and the release of the flammable gas.

Design of a DSP-Based Real-Time Control Device for Railway Vehicle Simulation

Yuan Yuan,Wenjun Meng,Jisheng Hu 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.10

A real-time control device for railway vehicle simulation is designed in this study according to the experimental requirements of a railway vehicle electric traction and electric braking system. The device uses the high-speed processing characteristic of DSP and runs on the basis of both DSP and the corresponding experimental platform. The simulation experiment for a different power grade traction system is achieved through control of the device. Full static and dynamic simulation of the operating condition of the train electric traction and braking system is attained in the case of no commissioning.

Cloning of α-Farnesene Synthase cDNA and its Expression in Relation to α-Farnesene Synthesis in ‘White Pearman’ Apple

Meng Li,Yuan-Hu Zhang,Na Sui 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

DENSE GAS IN MOLECULAR CORES ASSOCIATED WITH<i>PLANCK</i>GALACTIC COLD CLUMPS

Yuan (袁敬华,), Jinghua,Wu, Yuefang,Liu, Tie,Zhang, Tianwei,Li, Jin Zeng,Liu, Hong-Li,Meng, Fanyi,Chen, Ping,Hu, Runjie,Wang, Ke American Astronomical Society 2016 The Astrophysical journal Vol.820 No.1

<P>We present the first survey of dense gas toward Planck Galactic Cold Clumps (PGCCs). Observations in the J = 1-0 transitions of HCO+ and HCN toward 621 molecular cores associated with PGCCs were performed using the Purple Mountain Observatory's 13.7 m telescope. Among them, 250 sources were detected, including 230 cores detected in HCO+. and 158 in HCN. Spectra of the J = 1-0 transitions from (CO)-C-12, (CO)-C-13, and (CO)-O-18 at the centers of the 250 cores were extracted from previous mapping observations to construct a multi-line data set. The significantly low detection rate of asymmetric double-peaked profiles, together with the good consistency among central velocities of CO, HCO+, and HCN spectra, suggests that the CO-selected Planck cores are more quiescent than classical star-forming regions. The small difference between line widths of (CO)-O-18. and HCN indicates that the inner regions of CO-selected Planck cores are no more turbulent than the exterior. The velocity-integrated intensities and abundances of HCO+ are positively correlated with those of HCN, suggesting that these two species are well coupled and chemically connected. The detected abundances of both HCO+ and HCN are significantly lower than values in other low- to high-mass star-forming regions. The low abundances may be due to beam dilution. On the basis of an inspection of the parameters given in the PGCC catalog, we suggest that there may be about 1000 PGCC objects that have a sufficient reservoir of dense gas to form stars.</P>

Measurement of TOF of fast neutrons with ²³⁸U target

Li, Meng,Guan, Yuanfan,Lu, Chengui,Zhang, Junwei,Yuan, Xiaohua,Duan, Limin,Yang, Herun,Hu, Rongjiang,He, Zhiyong,Wei, Xianglun,Ma, Peng,Gan, Zaiguo,Yang, Chunli,Zhang, Hongbin,Chen, Liang,Qiu, Tianli Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6

We developed a Dual-PPACs detector for fast neutron measurements that consists of two sets of PPAC: conventional PPAC and fission PPAC. A²³⁸U(U₃O₈) coating is placed in the fission PPAC's anode, which is used as the neutrons conversion layer. An experiment was performed to measure neutron time-of-flight (TOF) in which ²⁵²Cf spontaneous fission source was used. An excellent time resolution of 164ps has been observed at 6 mbar in isobutene gas. With the excellent time resolution of Dual-PPACs detector, exact neutron energy can be extracted from the timing measurement. The experimental detection efficiency was 1.9 × 10^-7, consistent with the efficiency of 2.5 × 10^-7 given by a Geant4 simulation. Ultimately, the results show that the Dual-PPACs detector is a suitable candidate for measuring fast neutrons in the future CiADS system.

Portable Laser Doppler Flowmeter for Microcirculation Detection

Chang-Lin Hu,Meng-Lin Li,Zhan-Sheng Lin,Yen-Yu Chen,Yuan-Hsiang Lin 대한의용생체공학회 2013 Biomedical Engineering Letters (BMEL) Vol.3 No.2

Purpose The microcirculatory system of the human body is closely related to its physiological conditions. The laser Doppler flowmeter can detect symptoms through variations in the microcirculation; however, the present commercial Doppler flowmeter is very expensive, heavy, and inconvenient to carry. Therefore, an inexpensive, small, and portable laser Doppler flowmeter is proposed. Methods In this study, we designed a laser Doppler flowmeter transmitting receiving module based on the fundamental principles of laser Doppler, using a common computer for flow calculation. A self-designed correction system was used to validate the portable laser Doppler flowmeter. Results The coefficient of correlation between the mean frequency offset <ω> of the flowmeter and the actual mimicked blood flow rate reached a high value of R = 0.99, and the variations in microcirculation flow could be accurately measured. Conclusions The results proved that the low-cost portable laser Doppler flowmeter can be used extensively in early symptom detection for disease prevention and control.

Behavioral Responses of Pregnant Women to the Early Stage of COVID-19 Pandemic in the Network Era in China: Online Questionnaire Study

Wen-sheng Hu,Sha Lu,Meng-yan Xu,Min-cong Zhou,Zhen-ming Yuan,Yue-yue Deng 한국간호과학회 2021 Asian Nursing Research Vol.15 No.3

Purpose: The aim of this study was to examine the behavioral responses of pregnant women during the early stage of Coronavirus Disease 2019 (COVID-19) outbreak. Methods: We recruited 1,099 women to complete an online questionnaire survey from February 10 to February 25, 2020. The subjects were divided into two groups (the pregnant women group and the control group). Results: Concerns about infection: most of the participants watched the COVID-19 news at least once a day. Protective behaviors: the utilization rate of pregnant women (often using various measures) was higher than that of nonpregnant women. Exercise: 30.6% of the pregnant women continued to exercise at home, whereas in the control group, this percentage was 8.4%. Spouse relationship: 38.8% of the subjects’ relationship improved, whereas only 2.3% thought the relationship was getting worse. Conclusion: Pregnant women had some unique behavioral responses different from that of nonpregnant women. It is important to understand the behavioral responses of pregnant women in this network era.

Frequency Characteristics of the Synchronous-Frame Based D-Q Methods for Active Power Filters

WANG Xiaoyu,LIU Jinjun,HU Jinku,MENG Yuji,YUAN Chang 전력전자학회 2008 JOURNAL OF POWER ELECTRONICS Vol.8 No.1

The d-q harmonic detecting algorithms are dominant methods to generate current references for active power filters (APF). They are often implemented in the synchronous frame and time domain. This paper researches the frequency characteristics of d-q synchronous transformations, which are closely related to the analysis and design issues of control system. Intuitively, the synchronous transformation is explained with amplitude modulation (AM) in this paper. Then, the synchronous filter is proven to be a time-invariant and linear system, and its transfer function matrix is derived in the stationary frames. These frequency-domain models imply that the synchronous transformation has an equivalent effect of frequency transformation. It is because of this feature, the d-q method achieves band-pass characteristics with the low pass filters in the synchronous frame at run time. To simplify these analytical models, an instantaneous positive-negative sequence frame is proposed as expansion of traditional symmetrical components theory. Furthermore, the synchronous filter is compared with the traditional bind-pass filters based on these frequency-domain analytical models. The d-q harmonic detection methods are also improved to eliminate the inherent coupling effect of synchronous transformation. Typical examples are given to verify previous analysis and comparison. Simulation and experimental results are also provided for verification.

Frequency-Domain Transformation Approaches to Develop the d-q Synchronous-Frame Models of Three-Phase Symmetrical Networks and Applications in Modeling of PWM Power Converters

Xiaoyu Wang,Jinjun Liu,Yuji Meng,Jinku Hu,Chang Yuan 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

Although state-space averaging small-signal modeling techniques are successfully established in DC-DC converters and three-phase sinusoidal PWM converters, these approaches are limited only to low-order systems, and the modeling process is very complex. This paper proposes two equivalent approaches in frequency domain to develop the d-q synchronous-frame models from stationary-frame models for arbitrary three-phase symmetrical circuits. The first modeling approach is illustrated with frequency transformation, by which the target synchronous-frame models could be easily obtained by frequency transformation of the prototype stationary-frame models. The second modeling approach is based on the reactive elements substitutions. These two approaches can be proven to be equivalent, and the first approach is suitable for input-output models, while the second approach is preferable for state-space models. As illustrative examples, these approaches are applied to develop the synchronous-frame models of large three-phase systems with PWM converters. They are proven valid with the comparison with current published models.

Frequency Characteristics of the d-q Synchronous-Frame Current Reference Generation Methods for Active Power Filter

Xiaoyu Wang,Jinjun Liu,Jinku Hu,Yuji Meng,Chang Yuan 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

The d-q harmonics detection algorithms are dominant methods to generate current reference for active power filter (APF). They are often processed in synchronous frame and time domain. This paper researches the frequency characteristics of d-q synchronous transformation which are quite related to the design of close loop regulator and analysis of the performance. Intuitively, the synchronous transformation is explained with amplitude modulation (AM) in this paper. Then the synchronous filter is proven as time-invariant linear transformation and modeled with transfer functions in stationary frame and frequency domain. The frequency-domain analytical models imply that the synchronous transformation has an equivalent effect of frequency transformation, with which the synchronous filter achieves a band pass filter from the low pass filter in synchronous frame. To simplify the analytical model, an instantaneous positive/negative sequence frame is proposed as an expansion of symmetrical components theory. Based on these frequency analytical models, the synchronous filter is compared with the traditional filters in stationary frame. Further more, the d-q harmonics detection methods are improved to get rid of the inherent coupling of synchronous transformation. Typical examples are given to verify previous analysis and comparison. Simulation and experimental results are also given.