Search

Your search keyword '"Chen, Yizhao"' showing total 414 results
Start Over Author "Chen, Yizhao"
414 results on '"Chen, Yizhao"'

102. Isocyanoacetate-Aldehyde Polymerization: A Facile Tool toward Functional Oxazoline-Containing Polymers

Author

Cheng, Tianyu, Chen, Yizhao, Ding, Jie, Qin, Anjun, Tang, Benzhong, Cheng, Tianyu, Chen, Yizhao, Ding, Jie, Qin, Anjun, and Tang, Benzhong

Abstract

As an important nitrogen source, isocyanides have been involved in numerous organic reactions. As a result, many complicated compounds have been successfully synthesized through isocyanide chemistry. However, compared with its popular research in organic reactions, the application of isocyanides in polymerization is less investigated. In this work, a new polymerization based on isocyanide monomers is established. By simply mixing diisocyanoacetates and dialdehydes in the presence of a catalytic system of CuCl/PPh3/organobase in dichloromethane at room temperature readily produces soluble and thermally stable oxazoline-containing polymers with moderate weight-averaged molecular weights (Mw up to 11 200) in excellent yields (up to 97%) after 6 h. Furthermore, introducing the tetraphenylethene moiety into the main chains endows the resultant polymers with aggregation-induced emission, which can function as fluorescent probes for Fe3+ ion detection with high sensitivity and selectivity. This work not only enriches the family of isocyanide-based polymerizations but also provides an efficient tool for the preparation of functional heterocycle-containing polymers. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Published
2020

116. Community Integrated Earth System Model (CIESM): Description and Evaluation

Author

Lin, Yanluan, primary, Huang, Xiaomeng, additional, Liang, Yishuang, additional, Qin, Yi, additional, Xu, Shiming, additional, Huang, Wenyu, additional, Xu, Fanghua, additional, Liu, Li, additional, Wang, Yong, additional, Peng, Yiran, additional, Wang, Lanning, additional, Xue, Wei, additional, Fu, Haohuan, additional, Zhang, Guang Jun, additional, Wang, Bin, additional, Li, Ruizhe, additional, Zhang, Cheng, additional, Lu, Hui, additional, Yang, Kun, additional, Luo, Yong, additional, Bai, Yuqi, additional, Song, Zhenya, additional, Wang, Minqi, additional, Zhao, Wenjie, additional, Zhang, Feng, additional, Xu, Jingheng, additional, Zhao, Xi, additional, Lu, Chunsong, additional, Chen, Yizhao, additional, Luo, Yiqi, additional, Hu, Yong, additional, Tang, Qiang, additional, Chen, Dexun, additional, Yang, Guangwen, additional, and Gong, Peng, additional

Published
2020
Full Text
View/download PDF

125. Mass fraction assignment of Bisphenol-A high purity material

Author

Steven Westwood, Gustavo Martos, Ralf Josephs, Tiphaine Choteau, Robert Wielgosz, Stephen Davies, Michael Moawad, Greg Tarrant, Benjamin Chan, Mahiuddin Alamgir, Eliane de Rego, Wagner Wollinger, Bruno Garrido, Jane Fernandes, Rodrigo de Sena, Rodrigo Oliveira, Jeremy Melanson, Jennifer Bates, Phuong Mai Le, Juris Meija, Can Quan, Ting Huang, Wei Zhang, Ruian Ma, Shaofeng Zhang, Yuan Hao, Yaiuan He, Shanjun Song, Haifeng Wang, Fuhai Su, Tianji Zhang, Hongmei Li, Wai-hing Lam, Wai-fun Wong, Wai-hong Fung, Rosemarie Philipp, Ute Dorgerloh, Klas Meyer, Christian Piechotta, Juliane Riedel, Tanja Westphalen, P Giannikopoulou, Ch Alexopoulos, E Kakoulides, Yuko Kitamaki, Taichi Yamazaki, Yoshitaka Shimizu, Miho Kuroe, Masahiko Numata, Alejanro Pérez-Castorena, Miryan Balderas-Escamilla, Judith Garcia-Escalante, Anatoliy Krylov, Alena Mikheeva, Mikhail Beliakov, Marina Palagina, Irina Tkachenko, Sergey Spirin, Vadim Smirnov, Teo Tang Lin, Cheow Pui Sze, Wang Juan, Wong Lingkai, Lu Ting, Liu Qinde, Chen Yizhao, Sim Lay Peng, Maria Fernandes-Whaley, Des Prevoo-Franzsen, Laura Quinn, Nontete Nhlapo, Dennis Mkhize, Dominique Marajh, Sabelo Chamane, Seonghee Ahn, Kiwhan Choi, Sunyoung Lee, Jeesoo Han, Song-Yee Baek, Byungjoo Kim, Sornkrit Marbumrung, Pornnipa Jongmesuk, Kittiya Shearman, Cheerapa Boonyakong, Mine Bilsel, Simay Gündüz, Ilker Ün, Hasibe Yilmaz, Gökhan Bilsel, Taner Gökçen, Cailean Clarkson, John Warren, and Eli Achtar

Subjects
Bisphenol A, chemistry.chemical_compound, Chromatography, Chemistry, General Engineering, Mass fraction
Abstract

Main text The CCQM-K148.a comparison was coordinated by the BIPM on behalf of the CCQM Organic Analysis Working Group for NMIs and DIs which provide measurement services in organic analysis under the CIPM MRA. It was undertaken as a "Track A" comparison within the OAWG strategic plan. CCQM-K148.a demonstrates capabilities for assigning the mass fraction content of a solid organic compound having moderate molecular complexity, where the compound has a molar mass in the range (75 - 500) g/mol and is non-polar (pKow < −2), when present as the primary organic component in a neat organic solid and where the mass fraction content of the primary component in the material is in excess of 950 mg/g. Participants were required to report the mass fraction of Bisphenol A present in one supplied unit of the comparison material. Participants using a mass balance method for the assignment were also required to report their assignments of the impurity components present in the material. Methods used by the seventeen participating NMIs or DIs were predominantly based on either stand-alone mass balance (summation of impurities) or qNMR approaches, or the combination of data obtained using both methods. The results obtained using thermal methods based on freezing-point depression methods were also reported by a limited number of participants. There was excellent agreement between assignments obtained using all three approaches to assign the BPA content. The assignment of the values for the mass fraction content of BPA consistent with the KCRV was achieved by most of the comparison participants with an associated relative standard uncertainty in the assigned value in the range (0.1 - 0.5)%. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Published
2021

126. Physical strength improvement of Eucalyptus alkaline hydrogen peroxide mechanical pulp by low-temperature plasma treatment

Author

Yuan Zhao, Chongxing Huang, Cuicui Li, Dongjie Xue, Mingxiu Zhu, and Chen Yizhao

Subjects
Environmental Engineering, Argon, Materials science, Pulp (paper), chemistry.chemical_element, Bioengineering, 02 engineering and technology, engineering.material, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Nitrogen, Oxygen, 0104 chemical sciences, chemistry.chemical_compound, chemistry, Chemical engineering, Ultimate tensile strength, engineering, Gas chromatography, Vacuum level, Composite material, 0210 nano-technology, Hydrogen peroxide, Waste Management and Disposal
Abstract

Low-temperature plasma treatment technology is an efficient and environmentally friendly surface treatment technology that has been extensively studied for the surface chemical modification to pulp fibers. In this study, Eucalyptus alkaline peroxide mechanical pulp (APMP) fibers were modified using a low-temperature plasma generator. The tensile index of the fibers after low-temperature plasma treatment under different conditions was measured and analyzed to evaluate the relationship between the plasma treatment conditions and the physical strength improvement of APMP. It was revealed that factors such as gas source (oxygen, argon, and nitrogen gases), discharge power, vacuum level, and modification time affected the physical strength properties of APMP. In addition, the change in carboxyl group content in the pulp fibers after low-temperature plasma treatment was measured using the Headspace Gas Chromatography (HS-GC) method. The carboxyl content in the fiber increased remarkedly after low-temperature plasma treatment, which was beneficial for improving the physical strength properties of paper made from the APMP.

Published
2017

128. Alkyne–Azide Click Polymerization Catalyzed by Magnetically Recyclable Fe3O4/SiO2/Cu2O Nanoparticles

Author

Chen, Yizhao, Cheng, Tianyu, Qin, Anjun, Tang, Benzhong, Chen, Yizhao, Cheng, Tianyu, Qin, Anjun, and Tang, Benzhong

Abstract

The Cu(I)-catalyzed click polymerization fully meets the trend of developing powerful and economic tools for facile synthesis of functional polymers. However, the use of Cu(I) catalyst generally results in polymers with high copper residuals, which complicate the polymer purification and limit their applications. Moreover, these catalysts can only be used one time. Inspired by the report that Fe3O4-based nanoparticles can be used as magnetically recyclable catalysts, these magnetic nanoparticles are used to produce Fe3O4/SiO2/Cu2O catalysts. These magnetic nanoparticles can efficiently catalyze the azide–alkyne click polymerization under mild reaction conditions, producing 1,4-regioregular polytriazoles with high molecular weights in excellent yields. The copper residuals in the polymer products are much lower than those catalyzed by the conventional Cu(I) catalysts. Moreover, the Fe3O4/SiO2/Cu2O can be recycled and reused for at least 12 times. Introducing aggregation-induced emission (AIE)-active tetraphenylethylene unit into the polymer main-chains endows the resultant polymer with AIE feature, too. Thus, this work not only simplifies the polymer purification procedures, but also provides a general strategy to reduce the copper residues in the polymers. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Published
2019

129. Surface Characterization of Plasma-treated Eucalyptus Alkaline Peroxide Mechanical Pulp using Electronic Spectroscopy Chemical Analysis and Atomic Force Microscopy

Author

Ying Liu, Chongxing Huang, Li Zhijia, Cuicui Li, Yuan Zhao, and Chen Yizhao

Subjects
Environmental Engineering, Pulp (paper), chemistry.chemical_element, Bioengineering, Plasma, engineering.material, Carbohydrate, Electron spectroscopy, Oxygen, Eucalyptus, Hydrophobe, chemistry.chemical_compound, chemistry, engineering, Lignin, Waste Management and Disposal, Nuclear chemistry
Abstract

Eucalyptus alkaline peroxide mechanical pulp (APMP) fibers were modified by a low-temperature plasma (LTP) treatment within an air and oxygen mixture. An atomic force microscope (AFM) and electronic spectroscopy chemical analysis (ESCA) were used to analyze the morphological and chemical information of eucalyptus APMP fibers. According to the AFM results, LTP treatment etched the fibers’ surface, allowing for the removal of hydrophobic substances from the surface. According to the ESCA, the oxygen to carbon ratio of the APMP fiber surface increased from 50.08% to 55.47%, and the C1 peak area decreased from 8.89% to 8.45% after a LTP treatment. All of these results indicate that a LTP treatment can modify the APMP fibers and reduce the contents of lignin and extractives, thus exposing more carbohydrate.

Published
2018

133. Explicit Representation of Grazing Activity in a Diagnostic Terrestrial Model: A Data‐Process Combined Scheme

Author

Chen, Yizhao, primary, Ju, Weimin, additional, Mu, Shaojie, additional, Fei, Xinran, additional, Cheng, Yuan, additional, Propastin, Pavel, additional, Zhou, Wei, additional, Liao, Cuijuan, additional, Chen, Luxiao, additional, Tang, Rongjun, additional, Qi, Jiaguo, additional, Li, Jianlong, additional, and Ruan, Honghua, additional

Published
2019
Full Text
View/download PDF

134. Contemporary Environmental Changes over the Dry Land Belt of Northern Eurasia and Their Consequences

Author

Groisman, Pavel, primary, Bulygina, Olga, additional, Henebry, Geoffrey, additional, Shiklomanov, Alexander, additional, Speranskaya, Nina, additional, Chen, Yizhao, additional, Chebakova, Nadezhda, additional, Parfenova, Elena, additional, Tilinina, Natalia, additional, Zolina, Olga, additional, Dufour, Ambroise, additional, Chen, Jiquan, additional, John, Ranjeet, additional, Fan, Peilei, additional, Mátyás, Csaba, additional, Yesserkepova, Irina, additional, and Kaipov, Ildan, additional

Published
2019
Full Text
View/download PDF

135. High polarity analytes in biological matrix: determination of urea and uric acid in human serum (CCQM-K109)

Author

Liu, Qinde, primary, Liu, Hong, additional, Chen, Yizhao, additional, Yong, Sharon, additional, Teo, Hui Ling, additional, Wong, Lingkai, additional, Teo, Tang Lin, additional, Vamathevan, Veronica, additional, Rego, Eliane C P do, additional, Wollinger, Wagner, additional, Fernandes, Jane L N, additional, Monteiro, Tania M, additional, Garrido, Bruno C, additional, Violante, Fernando M, additional, Shi, Lian Hua, additional, He, Hai Hong, additional, Quan, Can, additional, Xu, Bei, additional, Li, Hong Mei, additional, Dai, Xin Hua, additional, He, Ya Juan, additional, Lo, Man-fung, additional, Yip, Yiu-chung, additional, Cabillic, Julie, additional, Delatour, Vincent, additional, Ohlendorf, Rüdiger, additional, Henrion, Andre, additional, Kawaguchi, Migaku, additional, Kang, Dukjin, additional, Lee, Hwashim, additional, Osuna, Mariana Arce, additional, Serrano, Victor, additional, Arzate, Claudia Marcela Salazar, additional, Krylov, Anatoliy, additional, Lopushanskaya, E, additional, Nammoonnoy, Jintana, additional, Gören, Ahmet Ceyhan, additional, Gündüz, Simay, additional, Yilmaz, Hasibe, additional, Mussell, Christopher, additional, Warren, John, additional, Pritchett, Jeanita S, additional, Lippa, Katrice, additional, Nelson, Michael A, additional, Toman, Blaza, additional, Sniegoski, Lorna T, additional, and Duewer, David, additional

Published
2019
Full Text
View/download PDF

138. Comparison of CRMs and value-assigned quality controls: urea and uric Acid in human serum or plasma (CCQM-K142)

Author

Teo, Tang Lin, primary, Liu, Qinde, additional, Cheow, Pui Sze, additional, Duewer, David, additional, Lippa, Katrice, additional, Toman, Blaza, additional, Osuna, Mariana Arce, additional, Serrano, Victor, additional, Arzate, Claudia Marcela Salazar, additional, Wong, Lingkai, additional, Chen, Yizhao, additional, Yong, Sharon, additional, Teo, Hui Ling, additional, Liu, Hong, additional, Tong, Benny, additional, Kang, Dukjin, additional, Lee, Hwashim, additional, Dai, Xin Hua, additional, Quan, Can, additional, Shi, Lian Hua, additional, Li, Hong Mei, additional, and Pritchett, Jeanita S, additional

Published
2019
Full Text
View/download PDF

142. Dryland belt of Northern Eurasia: contemporary environmental changes and their consequences

Author

Groisman, Pavel, primary, Bulygina, Olga, additional, Henebry, Geoffrey, additional, Speranskaya, Nina, additional, Shiklomanov, Alexander, additional, Chen, Yizhao, additional, Tchebakova, Nadezhda, additional, Parfenova, Elena, additional, Tilinina, Natalia, additional, Zolina, Olga, additional, Dufour, Ambroise, additional, Chen, Jiquan, additional, John, Ranjeet, additional, Fan, Peilei, additional, Mátyás, Csaba, additional, Yesserkepova, Irina, additional, and Kaipov, Ildan, additional

Published
2018
Full Text
View/download PDF

143. Measurement of urine albumin by liquid chromatography-isotope dilution tandem mass spectrometry and its application to value assignment of external quality assessment samples and certification of reference materials.

Author

Chen, Yizhao, Liu, Hong, Loh, Tze Ping, Liu, Qinde, Teo, Tang Lin, Lee, Tong Kooi, and Sethi, Sunil Kumar

Subjects
*REFERENCE sources, *ALBUMINS, *URINE, *SERUM albumin, *DILUTION
Abstract

Urine albumin is measured in clinical laboratories by immunoturbidimetry. However, large biases are observed among the different routine methods. To standardize the measurement of urine albumin, a reference measurement procedure (RMP) and urine albumin certified reference materials (CRMs) are needed. A candidate RMP for urine albumin based on liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) using human serum albumin as calibration standard was developed. Isotope-labeled human albumin was used as internal standard. Urine samples were digested using trypsin and eight resulting "signature" peptides of albumin were quantified by LC-IDMS/MS. The candidate RMP was employed in value assignment of external quality assessment (EQA) samples and certification of urine albumin reference materials. The commutability of the developed CRMs was assessed against patient samples. The candidate RMP (recovery 101.5–103.2% and CV 1.2–3.3% at about 7–40 mg/L) met optimal performance goal. The lower limit of quantification was 0.03 mg/L as determined by signal-to-noise method. The EQA results from clinical laboratories using different immunoturbidimetric methods were generally comparable with assigned target values determined by the candidate RMP, with albumin concentrations ranging from 5 to 226 mg/L. Urine albumin reference materials (two levels) certified using the candidate RMP showed good commutability in a preliminary study. With optimal method precision and trueness, as well as comparability with routine methods, the developed RMP may be used for value assignment of EQA samples or certification of reference materials, which are important pillars in urine albumin method standardization. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

144. Direct response of tree growth to soil water and its implications for terrestrial carbon cycle modelling.

Author

Eckes‐Shephard, Annemarie H., Tiavlovsky, Egor, Chen, Yizhao, Fonti, Patrick, and Friend, Andrew D.

Subjects
CARBON cycle, EUROPEAN larch, TREE-rings, CONIFERS, GREEN'S functions, TEMPERATE forests, TREE growth
Abstract

Wood growth constitutes the main process for long‐term atmospheric carbon sequestration in vegetation. However, our understanding of the process of wood growth and its response to environmental drivers is limited. Current dynamic global vegetation models (DGVMs) are mainly photosynthesis‐driven and thus do not explicitly include a direct environmental effect on tree growth. However, physiological evidence suggests that, to realistically model vegetation carbon allocation under increased climatic stressors, it is crucial to treat growth responses independently from photosynthesis. A plausible growth response function suitable for global simulations in DGVMs has been lacking. Here, we present the first soil water‐growth response function and parameter range for deciduous and evergreen conifers. The response curve was calibrated against European larch and Norway spruce in a dry temperate forest in the Swiss Alps. We present a new data‐driven approach based on a combination of tree ring width (TRW) records, growing season length and simulated subdaily soil hydrology to parameterize ring width increment simulations. We found that a simple linear response function, with an intercept at zero moisture stress, used in growth simulations reproduced 62.3% and 59.4% of observed TRW variability for larch and spruce respectively and, importantly, the response function slope was much steeper than literature values for soil moisture effects on photosynthesis and stomatal conductance. Specifically, we found stem growth stops at soil moisture potentials of −0.47 MPa for larch and −0.66 MPa for spruce, whereas photosynthesis in trees continues down to −1.2 MPa or lower, depending on species and measurement method. These results are strong evidence that the response functions of source and sink processes are indeed very different in trees, and need to be considered separately to correctly assess vegetation responses to environmental change. The results provide a parameterization for the explicit representation of growth responses to soil water in vegetation models. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results