The Optimization Algorithm for the Pathfinder Sea Surface Temperature in the East China Seas

Song, Dehai,Bao, Xianwen,Wang, Xiao Hua,Wu, Wen 한국해양학회 2009 Ocean science journal Vol.44 No.1

Based on the analysis of the quality level in a Pathfinder 4km daily nighttime Sea Surface Temperature product (PFSST) in the East China Seas (ECS) from 1985 to 2004, the proportion of high-quality data was lower than that in the global level. Additionally, the PFSST maps showed clearly the void and anomaly data impacted by atmospheric contamination. In order to solve the above problem, an optimal algorithm was established through introducing the structure function, setting up the daily first-guess sea surface temperature (SST) field and taking PFSST product of the highest quality as reference points. Comparisons were done between this optimally interpolated SST and the selected original PFSST and the simultaneous in situ measurements. It illustrated it was possible to exactly estimate the SST values in the ECS during the recent two decades. The mean bias error and the root mean square error between data sets optimally evaluated and in situ observed were lower than those between the previous global estimations and in situ measurnments.

The Optimization Algorithm for the Pathfinder Sea Surface Temperature in the East China Seas

Dehai Song,Xianwen Bao,Xiao Hua Wang,Wen Wu 한국해양과학기술원 2009 Ocean science journal Vol.44 No.1

Based on the analysis of the quality level in a Pathfinder 4km daily nighttime Sea Surface Temperature product (PFSST) in the East China Seas (ECS) from 1985 to 2004, the proportion of high-quality data was lower than that in the global level. Additionally, the PFSST maps showed clearly the void and anomaly data impacted by atmospheric contamination. In order to solve the above problem, an optimal algorithm was established through introducing the structure function, setting up the daily first-guess sea surface temperature (SST) field and taking PFSST product of the highest quality as reference points. Comparisons were done between this optimally interpolated SST and the selected original PFSST and the simultaneous in situ measurements. It illustrated it was possible to exactly estimate the SST values in the ECS during the recent two decades. The mean bias error and the root mean square error between data sets optimally evaluated and in situ observed were lower than those between the previous global estimations and in situ measurnments. Based on the analysis of the quality level in a Pathfinder 4km daily nighttime Sea Surface Temperature product (PFSST) in the East China Seas (ECS) from 1985 to 2004, the proportion of high-quality data was lower than that in the global level. Additionally, the PFSST maps showed clearly the void and anomaly data impacted by atmospheric contamination. In order to solve the above problem, an optimal algorithm was established through introducing the structure function, setting up the daily first-guess sea surface temperature (SST) field and taking PFSST product of the highest quality as reference points. Comparisons were done between this optimally interpolated SST and the selected original PFSST and the simultaneous in situ measurements. It illustrated it was possible to exactly estimate the SST values in the ECS during the recent two decades. The mean bias error and the root mean square error between data sets optimally evaluated and in situ observed were lower than those between the previous global estimations and in situ measurnments.

A strain hardening model for the stress-path-dependent shear behavior of rockfills

Xu, Ming,Song, Erxiang,Jin, Dehai Techno-Press 2017 Geomechanics & engineering Vol.13 No.5

Laboratory investigation reveals that rockfills exhibit significant stress-path-dependent behavior during shearing, therefore realistic prediction of deformation of rockfill structures requires suitable constitutive models to properly reproduce such behavior. This paper evaluates the capability of a strain hardening model proposed by the authors, by comparing simulation results with large-scale triaxial stress-path test results. Despite of its simplicity, the model can simulate essential aspects of the shear behavior of rockfills, including the non-linear stress-strain relationship, the stress-dependence of the stiffness, the non-linear strength behavior, and the shearing contraction and dilatancy. More importantly, the model is shown to predict the markedly different stress-strain and volumetric behavior along various loading paths with fair accuracy. All parameters required for the model can be derived entirely from the results of conventional large triaxial tests with constant confining pressures.

Alternating Copolymer of Sulfonated Poly(ether ether ketone-benzimidazole)s (SPEEK-BI) Bearing Acid and Base Moieties

Wang, Jianli,Song, Yilin,Zhang, Cheng,Ye, Zhibin,Liu, Hui,Lee, Myong-Hoon,Wang, Dehai,Ji, Jianbing WILEY-VCH Verlag 2008 Macromolecular Chemistry and Physics Vol.209 No.14

<P>A novel alternating copolymer of sulfonated poly(ether ether ketone-benzimidazole)s (SPEEK-BI) was synthesized by polycondensation of aromatic bisphenol containing benzimidazole and a mixture of sulfonated and non-sulfonated difluorobenzophenones. By varying the amount of two difluorobenzophenones, the ratio of sulfonic acid unit to imidazole base was controlled straightforwardly. The polymer structure was characterized by <SUP>1</SUP>H NMR and IR spectroscopy. Two different methods of ion exchange capacity measurement supported a strong inter- and intra-molecular interaction between acid and base units, which resulted in an improved mechanical strength as well as avoiding phase separation. Tough membranes with good mechanical stability in hot water (80 °C) and alcohol were obtained by solution casting, which is potential for applications in polymer electrolyte membrane fuel cells and membranes for separation of liquids or gases.</P><P> <img src='wiley_img/10221352-2008-209-14-MACP200700610-gra001.gif' alt='wiley_img/10221352-2008-209-14-MACP200700610-gra001'> </P>

Expediting the Formation of Cellulose Nanopaper by Heterocoagulation of Oppositely Charged Cellulose Nanofibers

Meng Kang,Chenglong Li,Dehai Yu,Guodong Li,Zhaoping Song,Huili Wang,Wenxia Liu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.7

Cellulose nanopaper has attracted tremendous attention as an alternative to fossil-based flexible substrates. However, the fabrication of nanopaper from cellulose nanofibers (CNFs) is a time-consuming process. Herein, positivelycharged CNFs (PCNFs) were employed to heterocoagulate negatively charged CNFs (NCNFs) at various PCNF-to-NCNFratios in order to decrease the formation time of nanopaper. At a PCNF-to-NCNF ratio of 1:1, the formation time was reducedfrom 98 min to 20 min. Although heterocoagulation increases the roughness of cellulose nanopaper, nanopapers made from amixture of NCNFs and PCNFs still possess a nanosized network structure and therefore show similar transparency tonanopapers made of pure NCNFs. Compared to the nanopaper made from pure NCNFs, the nanopaper made from themixture of NCNFs and PCNFs showed reduced tensile strength but improved resistance to deformation. This study providesa practical method for the production of cellulose nanopaper.

Fabrication of Transparent Cellulose Fiber Paper by Sequential Treatment of Cationic Cellulose Nanofibers and Polyvinylpyrrolidone

Furong Xin,Huili Wang,Feixiang Guan,Guodong Li,Zhaoping Song,Dehai Yu,Wenxia Liu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

Paper-based material is receiving more and more attention as an alternative of plastics in flexible electronics. However, conventional paper made of cellulose fibers is opaque owing to its micron-sized void space among fibers. Herein,cellulose fiber paper was changed into transparent paper by sequentially coating cationic cellulose nanofibers (CNFs) andpolyvinylpyrrolidone (PVP). The morphology, transparency, thermal and mechanical properties were analyzed. The resultsshow that the coating of CNFs reduces the micron-sized void space in the cellulose fiber paper, favoring the furtherimprovement on the transparency of paper by coating PVP. By optimizing the coating amount of CNFs and PVP, atransparent paper with a transmittance of 88.5 % at 550 nm is obtained. The as-prepared transparent paper also showsimproved thermal stability, slightly increased tensile strength and significantly enhanced deformation resistance. It was apotential candidate of flexible electronic substrates.