Fabrication of a Thermoregulating Cotton Fabric with Enhanced Flame Retardancy via Layer-by-layer Assembly

Yunbo Chen,Xiangyu Zhu,Luying Chen,Bijia Wang,ZhiPing Mao,Xueling Feng,Xiaofeng Sui,Hong Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.9

The lack of thermoregulating functionality and high flammability for cotton fabrics greatly restricts theirapplication in high-performance fields. Herein, we report a versatile layer-by-layer (LBL) assembly strategy for introducing amultilayered film consisting of phase change microcapsules and ammonium polyphosphate to cotton fabric, endowing cottonwith thermoregulation and flame retardant properties. The coated fabrics were characterized based on scanning electronmicroscopy (SEM), water-vapor transmission rate (WVT), thermogravimetry (TG), differential scanning calorimetry (DSC),limiting oxygen index (LOI) and infrared thermal imaging. A fabric deposited with 20 bilayers (MCPM/APP-20) shows anappropriate WVT (50.57 g/m2·h) and improved flame retardancy with an LOI of 24.5 % and residual carbon of 34.53 %. Italso shows a melting enthalpy of 30.09 J/g, which results in a temperature difference of 6.4 °C compared with pristine cotton. The functional properties endowed by the LBL assembly are found to be reasonably durable, with the melting enthalpy andresidual carbon of MPCM/APP-20 reduced to 17.69 J/g and 19.64 %, respectively, after 30 laundering cycles. This studyprovides a convenient way to develop multifunctional cotton fabrics that can be good candidates for high-performancetextiles.

Observation of multi-channel non-local transport in J-TEXT plasmas

Shi, Yuejiang,Chen, Zhongyong,Yang, Zhoujun,Shi, Peng,Zhao, Kaijun,Diamond, Patrick H.,Kwon, JaeMin,Yan, Wei,Zhou, Hao,Pan, Xiaoming,Cheng, Zhifeng,Chen, Zhiping,Yang, SeongMoo,Zhang, Chi,Li, Da,Dong, IOP 2018 Nuclear fusion. Fusion nucléaire. &n.Illiga Vol.58 No.4

<P>In cold pulse experiments in J-TEXT, not only are rapid electron temperature increases in the core observed, but also steep rises in the inner density are found. Moreover, some evidence of acceleration of the core toroidal rotation is also observed during the non-local transport process of electron temperature. These new findings of cold pulse experiments in J-TEXT suggest that turbulence spreading is a possible mechanism for the non-local transport dynamics.</P>

Segmentation of the Synthetic Aperture Radar Image Using the Watershed Transformation and Region Merging Technique

Chuanxian Jiang,Zhiping Li,Xiaohui Chen,Zejun Zhang,Yeqing Yi 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.9

This paper presents an efficient algorithm that segments the synthetic aperture radar (SAR) image into several homogeneous regions by combining edge- and region-based information. A multi-direction ratio edge detector is used to capture the locally directional variation information of a SAR image and construct the ratio edge strength map (RESM) of the SAR image. Watershed transformation is performed on the thresholded RESM to obtain an over-segmentation result. An efficient hierarchical region merging procedure based on the region adjacency graph representation of the image regions is proposed. A novel dissimilarity measurement between the two adjacent regions is derived from the multiplicative noise speckle model of the multi-look SAR image. Experimental results and the performance evaluation show that the proposed method outperforms two widely used SAR image segmentation approaches.

Buckling of simply supported thin plate with variable thickness under bi-axial compression using perturbation technique

Haigui Fan,Zhiping Chen,Zewu Wang,Peiqi Liu 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.70 No.5

An analytical research on buckling of simply supported thin plate with variable thickness under bi-axial compression is presented in this paper. Combining the perturbation technique, Fourier series expansion and Galerkin methods, the linear governing differential equation of the plate with arbitrary thickness variation under bi-axial compression is solved and the analytical expression of the critical buckling load is obtained. Based on that, numerical analysis is carried out for the plates with different thickness variation forms and aspect ratios under different bi-axial compressions. Four different thickness variation forms including linear, parabolic, stepped and trigonometric have been considered in this paper. The calculated critical buckling loads and buckling modes are presented and compared with the published results in the tables and figures. It shows that the analytical expressions derived by the theoretical method in this paper can be effectively used for buckling analysis of simply supported thin plates with arbitrary thickness variation, especially for the stepped thickness that used in engineering widely.

NINJ1 triggers extravillous trophoblast cell dysfunction through blocking the STAT3 signaling pathway

Zhang Xueluo,Chen Yanhua,Wang Xianping,Zhang Zhiping,Wang Jun,Shen Yan,Hu Yuanjing,Wu Xueqing 한국유전학회 2022 Genes & Genomics Vol.44 No.11

Background: Trophoblasts are the most important parts of the placenta in early pregnancy. Trophoblast cell dysfunction can induce embryo implantation insufficiency, thereby resulting in multiple diseases, including recurrent spontaneous abortion (RSA). A previous study indicates higher nerve injury-induced protein 1 (NINJ1) RNA levels in the villi tissues of RSA patients. Objective: This study aimed to investigate the effect of NINJ1 on trophoblast behaviors and pregnancy loss. Methods: Fresh villi tissues were obtained from with RSA patients and patients with artificial selective abortion for personal reasons, and NINJ1 expression in these tissues was detected. Extravillous trophoblast cell line HTR-8/SVneo was transfected with small-interfering RNA targeting NINJ1 or NINJ1 overexpression vector to perform loss-/gain-of-function experiments. Spontaneous abortion (SA) was induced by mating CBA/J females with DBA/2 males and the pregnant females were intraperitoneally injected with adenovirus vector carrying NINJ1 short hairpin RNA. Results: NINJ1 mRNA and protein levels were higher in the villi tissues of RSA patients than those of artificial selective abortion patients. NINJ1 knockdown promoted trophoblast cell proliferation, migration and invasion but inhibited cell apoptosis. Moreover, conditioned medium from NINJ1-depleted trophoblasts promoted the angiogenesis of human umbilical vein endothelial cells. NINJ1 knockdown also promoted activation of the signal transducer and activator of transcription 3 (STAT3) signaling pathway in trophoblasts, and STAT3 inhibitor reversed NINJ1 knockdown-induced effects on trophoblast behaviors. Furthermore, pregnancy loss was attenuated by NINJ1 inhibition. Conclusion: NINJ1 contributes to the development of SA and triggers trophoblast cell dysfunction through inhibiting the STAT3 pathway.

RESEARCH ON 3D AERATION INFRASTRUCTURE SHAPE OF HIGH-HEAD, LARGE- DISCHARGE SPILLWAY TUNNEL

ZHANG DONG,LIU ZHIPING,GAO JIANBIAO,FENG YONGXIANG,CHEN WENXUE 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Preparation of epoxypropyl functionalized graphene oxide and its anticorrosion properties complexed with epoxy resin

Xiaofeng Yang,Yuepeng Zhang,Zhiping Chen,Yinshuai Yang,Hongxia Jing,Zhenhao Sun,Huijie Wang 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12

Functionalized graphene oxide (GO)/epoxy resin (EP) composite coating has attracted attention due to its advantages of epoxy resin in acid resistance, anticorrosion and having the characteristics of GO such as good chemical stability and strong electrolyte barrier properties. In this study, epoxypropyl functionalized graphene oxide (EFGO) was synthesized with a new strategy by grafting epichlorohydrin (ECH) onto the surface of GO. EFGO was then crosslinked with EP by diethylenetriamine (DETA) to fabricate EFGO/EP anticorrosive coating. The structure and property of EFGO and EFGO/EP were characterized and evaluated by various methods such as FTIR, Raman, XPS, SEM, and EIS. The results showed that the graft amount of epoxypropyl on GO surface could be effectively increased by using KI-KF catalysis system. The increase of the graft amount further improved the compatibility between EFGO and EP. EFGO/EP had a network structure with EFGO as the “central node”. The “central node” locked the movement of EP chain segment, as improving the thermal stability of EFGO/EP. The EFGO/EP coating fabricated by the EFGO, which grafted larger epoxypropyl, had good anticorrosion performance and adhesion with steel plates, showing a good barrier effect on electrolyte migration. The coating resistance reached up 4.88×108 cm2.

Strain Rate Effects on the Mechanical Properties of an AlCoCrFeNi High-Entropy Alloy

Chuan Ting Wang,Yong He,Zhiping Guo,Xiaohui Huang,Ying Chen,Houan Zhang,Yuan He 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

The efect of strain rate on the compressive properties of an AlCoCrFeNi high-entropy alloy (HEA) was investigated. Microstructure of the AlCoCrFeNi HEA was observed using scanning transmission microscopy (SEM) and transmission electronmicroscopy. The results showed formation of a homogeneous two-phase structure. Quasi-static compression was testedunder initial engineering strain rates between 10–4 and 10–2 s−1. Engineering compression stress of exceeding 2500 MPaand ductility of around 12% was achieved. Dynamic mechanical behavior at room temperature was characterized by a splitHopkinson pressure bar under strain rates between 1350 and 4000 s−1. The AlCoCrFeNi HEA exhibited high strain ratesensitivity, especially under dynamic compression. The fuctuation of yield strength and the variation of strain rate hardening with strain rate was investigated. The various parameters of a constitutive equation for deformation of the AlCoCrFeNiHEA were obtained from the experimental data. The constitutive equations can be applied to predict the strength of alloyunder various stain rates.

Chemical–Mechanical Polishing of Cemented Carbide Insert Surface for Extended Tool Life in Turning of GH4169 Nickel-Based Superalloy

Zihua Hu,Changjiang Qin,Xiaogao Chen,Aimin Tang,Tao Fang,Zhiping Yang,Sheng Luo,Meijiao Mao 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.8

To extend the tool life of conventional uncoated grinding cemented carbide inserts (CUG inserts) in turning GH4169 nickelbased superalloy, chemical–mechanical polishing (CMP) is applied to appropriately treat the rake face of the CUG insert to address the defects including grinding burn, crack, and thermal deformation. The material removal rate (MRR) and the rake face roughness Ra of YG10 chemical–mechanical polished cemented carbide inserts (CMP inserts) corresponding to the six types of abrasives particles are investigated by applying the single factor method, and the diamond powder is the most suitable to polish YG10 inserts. Thus, CMP parameters are optimized using Taguchi method coupled with both the grey relation analysis and fuzzy inference. Furthermore, the comparison experiments of the cutting performance of the CUG insert and the CMP insert in turning GH4169 are carried out, under the same cutting condition, compared with the CUG insert, the average tool life of the CMP insert is increased by 35.92%. This study demonstrates that the CMP technique is an effective potential method to improve the surface integrity, the cutting performance and the tool life of conventional uncoated grinding cemented carbide inserts & tools in the machining of difficult-to-cut materials.

Nicotinamide Mononucleotide Adenylyl Transferase 2 Inhibition Aggravates Neurological Damage after Traumatic Brain Injury in a Rat Model

Xiaoyu Gu,Haibo Ni,XuGang Kan,Chen Chen,Zhiping Zhou,Zheng Ding,Di Li,Bofei Liu 대한신경외과학회 2023 Journal of Korean neurosurgical society Vol.66 No.4

Objective : Nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2) is a crucial factor for the survival of neuron. The role of NMNAT2 in damage following traumatic brain injury (TBI) remains unknown. This study was designed to investigate the role of NMNAT2 in TBI-induced neuronal degeneration and neurological deficits in rats. Methods : The TBI model was established in Sprague-Dawley rats by a weight-dropping method. Real-time polymerase chain reaction, western blot, immunofluorescence, Fluoro-Jade C staining, and neurological score analyses were carried out. Results : NMNAT2 mRNA and protein levels were increased in the injured-side cortex at 6 hours and peaked 12 hours after TBI. Knocking down NMNAT2 with an injection of small interfering RNA in lateral ventricle significantly exacerbated neuronal degeneration and neurological deficits after TBI, which were accompanied by increased expression of BCL-2-associated X protein (Bax). Conclusion : NMNAT2 expression is increased and NMNAT2 exhibits neuroprotective activity in the early stages after TBI, and Bax signaling pathway may be involved in the process. Thus, NMNAT2 is likely to be an important target to prevent secondary damage following TBI.