The Preparation and Characterization of Ultrafine Fatty Acid Ester/Poly(meta-phenylene isophthalamide) Phase Change Fibers Designed for Thermo-regulating Protective Clothing

Weiwang Chen,Shunjiang Ni,Wenguo Weng,Ming Fu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

Poly(meta-phenylene isophthalamide, PMIA)-based phase change fibers (PCFs) with fatty acid ester (i.e. HPCMEs) as the functional ingredient were successfully fabricated by emulsion electrospinning. Subsequent characterizations by FE-SEM, TEM, DSC and TGA were performed to investigate their morphology, structure, thermal storage and decomposition behavior, respectively. Experimental results reveal that the fabricated PCFs are randomly arranged and show a good cylindrical structure with fiber diameters ranging from tens to hundreds of nanometers. Most of the HPCMEs are well encapsulated by PMIA sheaths and appear as isolated segments or elongated channels inside the fiber. Given their proper phase change span (30-40 oC), considerable enthalpies, good shape stability and greatly enhanced thermal resistance, the prepared HPCMEs/PMIA PCFs are expected to have wide prospects in thermo-regulating protective clothing and other fields related to thermal energy storage.

A New Boiler-turbine-heating Coordinated Control Strategy to Improve the Operating Flexibility of CHP Units

Wei Wang,Guangming Zhang,Yuguang Niu,Zhenyu Chen,Peiran Xie,Zhe Chen 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.5

The operating flexibility of the power units is getting increasing attention from power systems especially those with large-scale fluctuating renewable energies. However, the combined heat and power (CHP) units are getting a bottleneck because their electricity productions are restricted by heat productions. This study aims to develop an electric-heat coordinated control strategy to make the CHP units more flexible. First of all, the dynamic model for a 300 MW CHP unit is set up, and its linear state-space description is obtained. A control strategy based on linear quadratic regulator (LQR) is then developed to satisfy different heat-power demands in various operating conditions. The control weights Q and R are optimized by particle swarm optimization. Moreover, the improved coordinated control strategy based on precise energy balance is put forward to increase the CHP power ramp rate considering electricity priority strategy and recovery control of the heat source. Finally, the simulation results show that the improved strategy is suitable for various CHP operating scenarios, and the case for electricity priority and heat recovery control significantly improves the unit power rate on the premise of stable heat supply. This work provides a reliable and flexible control mode for CHP units, which can support the power system stability and renewable energy integration.

Carbon disulfide induces mitochondria-mediated apoptosis in Sertoli-germ cells coculture

Wei Wang,Zhen Zhang,Yinsheng Guo,Yu Dong,Xiaoyu Huang1,Yijun Zhou,Guoyuan Chen 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.2

Carbon disulfide (CS2), a common organic solvent, induces a variety of adverse effects in the male reproductive system. In this study, we investigated the cytotoxicity, ultrastructural changes, and potential apoptotic induction mechanisms of CS2 in mixed cultures of Sertoli and germ cells. Sertoli and germ cells were cocultured and treated with CS2 for 24 h. Growth rates were noted, and apoptotic cells were identified by Hoechst 33258 staining. Ultrastructure changes were observed via transmission electron microscopy (TEM). Mitochondrial membrane potential and expressions of apoptosis-related factors (cytochrome c, Bax, Bcl- 2, caspase-3 and caspase-9) were examined by JC-1 staining, western blot, and real-time PCR. The results showed that CS2 treatment was associated with reduced growth rates of Sertoli-germ cells. Ultrastructure changes in Sertoli-germ cells treated with CS2 were typical of apoptosis. In addition, CS2 treatment depolarized mitochondrial membrane potential, upregulated Bax levels and downregulated Bcl-2 levels, released cytochrome c from the mitochondrial intermembrane space to the cytosol, and triggered mitochondria-mediated apoptosis. Subsequently, caspase-9 and caspase-3 were activated, resulting in Sertoli-germ cells apoptosis. The above data suggest that CS2 has adverse effect on the viability of Sertoli-germ cells and induces apoptosis through mitochondrial pathway.

Spatially and temporally restricted expression of PtrMYB021 regulates secondary cell wall formation in Arabidopsis

Wei Wang,Eryang Li,Ilga Porth,Jin-Gui Chen,Shawn D. Mansfield,Carl J. Douglas,Shucai Wang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.1

Among the R2R3 MYB transcription factors that involve in the regulation of secondary cell wall formation in Arabidopsis, MYB46 alone is sufficient to induce the entire secondary cell wall biosynthesis program. PtrMYB021, the poplar homolog of MYB46, has been reported to regulate secondary cell wall formation when expressed in Arabidopsis. We report here that spatially and temporally restricted expression of PtrMYB021 is critical for its function in regulating secondary cell wall formation. By using quantitative RT-PCR, we found that PtrMYB021 was expressed primarily in xylem tissues. When expressed in Arabidopsis under the control of PtrCesA8, but not the 35S promoter, PtrMYB021 increased secondary cell wall thickness, which is likely caused by increased lignification as well as changes in cell wall carbohydrate composition. In consistent with this, elevated expression of lignin and cellulose biosynthetic genes were observed in the transgenic plants. When expressed in Arabidopsis protoplasts as fusion proteins to the Gal4 DNA binding domain, PtrMYB021 activated the reporter gene Gal4-GUS. In summary, our results suggest that PtrMYB021 is a transcriptional activator, and spatially and temporally restricted expression of PtrMYB021 in Arabidopsis regulates secondary cell wall formation by activating a subset of secondary cell wall biosynthesis genes.

Ripplocations, kink bands and delamination cracks in carbon cathode materials

Wei Wang,Weijie Chen,Haitao Liu,Hongtao Zhang 한국탄소학회 2019 Carbon Letters Vol.29 No.4

A new deformation micromechanism operating in the carbon cathode for aluminum electrolysis termed a ripplocation has been proposed in this paper. The creep deformation of semi-graphitic cathode was measured using a modified Rapoport equipment at 965 °C with cryolite ratio = 4.0. The characteristic of the defect was obtained by analyzing TEM photograph of the carbon cathode with different testing times. The results indicated that basal dislocations, bulk ripplocations, kink bands and delamination cracks appeared in succession in the first two stages of the creep deformation. Ripplocations in the carbon cathode make a layer of carbon atoms to glide relative to each other without damaging the in-plane bonds. Ripplocations could also attract each other and result in kink boundaries. The creep strain of the carbon cathode could be accommodated by kink band and delamination cracks during aluminum electrolysis. A more comprehensive understanding of their micromechanics behaviors is very important and could deeply influence our current knowledge of the deformation mechanism of the carbon cathode for aluminum electrolysis.

AlN with Strong Blue Emission Synthesized Through a Solventless Route

Wei Wang,Peng Zhang,Xiaobai Wang,Xiang Lei,Xiaodong Chen,Hong Ding,Hua Yang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.2

Aluminum nitride (AlN) with strong blue emission at 450 nm has been synthesized from hexahydrate aluminum chloride and urea above 850℃ via a solventless route. Several aluminum and nitrogen sources are selected and well investigated to determine the effect of AlN synthesis. Moreover, the structure, component, morphology, photoluminescence properties and possible synthesis mechanism are also discussed carefully.

Influence of DSSs on Urban Air Quality in China during 2005-2010 and Analysis of a Severe DSS Event

Wei Wang,Liang Li,Benfeng Pan,Shuang Chen,Ruibin Wang,Jianjun Li,Haohao Zheng 한국기상학회 2013 Asia-Pacific Journal of Atmospheric Sciences Vol.49 No.1

In each year, Dust and Sandstorms (DSSs) triggered by cold air masses enhance particle concentration over large areas in China during spring and winter. In this paper, daily Air Pollution Index (API) of 113 major cities in China during dust events was analyzed to present the influence of DSSs on urban air quality. From 2005 to 2010, a total of 93 dust events were identified, on average there are approximately 16 dust events in a year. The number of total polluted days caused by DSSs in 113 major cities ranged from 147 to 546 each year, with maximum in 2010 and minimum in 2007. The number of total heavily polluted days caused by DSSs in major cities ranged from 14 to 78 each year, with maximum in 2010 and minimum in 2005. DSSs affected major cities most severely during March to May. Furthermore, a typical DSS observed from 26 to 31May 2008 was described in terms of meteorological features and PM10 concentration as well as API levels of 113 major cities. This event lead to high PM10 concentration and low visibility over major cities, with maximum daily PM10 concentration of 1511 μg m−3 in Chifeng on 28 May, which was directly caused by strong wind in front of surface high pressure system passing through sand source areas in Mongolia and North China. The most severe pollution occurred on 29 May, with 38 cities polluted and 7 cities heavily polluted.

Construction of China s Earthquake Emergency Response Capability Evaluation Index System

Wei Wang,Hong Chen,Lisiwen Ma,Minhao Qu 위기관리 이론과 실천 2020 Journal of Safety and Crisis Management Vol.10 No.3

Based on a review of the relevant literature and by tracking research on earthquake emergency response events in China and internationally, this paper constructs an index system for the evaluation of China’s earthquake emergency response capability. From the government, community, rescue force and public response perspectives, the system includes four first-level evaluation indicators, 14 second-level evaluation indicators, and 48 third-level evaluation indicators. Based on two questionnaires, the analytic hierarchy process (AHP) is used to calculate the weight of each indicator. This paper proposes a set of scientifically rigorous and objective indicators for evaluating China s earthquake emergency response capability. This is of great practical significance for improving the ability of earthquake emergency response, reducing casualties and property losses, forcing the construction of earthquake emergency preparedness, improving the ability of earthquake prevention and disaster reduction, and improving the construction of emergency management system.

Poly(N-vinylpyrrolidone)이 그래프트된 Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) 공중합체의 합성 및 결정화 거동

Wei Wang,Yu Zhang,Yan Mo Chen 한국고분자학회 2007 폴리머 Vol.31 No.5

Research on the Construction of the Emergency Search and Rescue Team for Earthquake Hazards in China

Wei Wang,Hong Chen,Ai Hui Xu 위기관리 이론과 실천 2018 Journal of Safety and Crisis Management Vol.8 No.1

Research was conducted using statistical data on the organization of emergency search and rescue team for earthquake hazards (ESRTEH) system in China. Field research was performed with regard to provincial-level ESRTEHs, and two provincial ESRTEH external classifications were investigated. Issues in the organization were identified, the concerns of which are as follows. (1) Rescue forces are not deployed according to the magnitude of risk or the rescue requirements of an area’s earth-quake hazards. (2) A series of standards to regulate team construction is lacking, as is a system to evaluate team capabilities. (3) Non-professional rescuers lack the necessary professional skills. (4) The current professional earthquake rescue training system is imperfect. (5) The overall management hierarchy of NGO rescue teams is lacking. The following measures for improvement are proposed. (1) Accelerate the preparation of relevant standards and norms for the organization of ESRTEH system. (2) Emphasize external classification of ESRTEHs, intensify the management of the rescue teams, and establish and improve the mechanisms for long-term assessments and comparisons. (3) Integrate NGO rescue teams into ESRTEH system.