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Phosphoric acid resistance Ptcu/c oxygen reduction reaction electrocatalyst for HT-PEMFcs: A theoretical and experimental study

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APPLIED SURFAcE ScIENcE 2023年第1期619卷

作者： Zhang, Xiaoming An, Zhao Xia, Zhangxun Li, Huanqiao Xu, Xinlong Yu, Shansheng Wang, Suli Sun, Gongquan Chinese Acad Sci Dalian Inst Chem Phys Div Fuel Cells & Battery Dalian Natl Lab Clean Energy Dalian 116023 Peoples R China Chinese Acad Sci Key Lab Fuel Cells & Hybrid Power Sources Dalian 116023 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China Jilin Univ Dept Mat Sci Changchun 130012 Peoples R China

In high temperature polymer electrolyte membrane fuel cells (HT-PEMFcs), dissociative H3PO4 in cathode will block the active sites of Pt-based electrocatalyst, which thus failure to catalyze the oxygen reduction reaction (ORR). Therefore, the electrocatalysts for the ORR in HT-PEMFcs with high resistance to H3PO4 poisoning are significantly important. Due to the similar bonding structure between HxPO43-x/O2 and Pt (Pt-O), the design of catalysts which could selectively reduce the adsorption energy of the H3PO4 is urgently needed. In this work, we screen proper H3PO4 resistance electrocatalysts through theoretical calculation based on the adsorption energy difference between HxPO43-x and O2 as an evaluation criterion. Then, we prepared a series of Ptxcu catalysts based on the theoretical calculation results and further studied the structure-performance relationship of phosphoric acid-resistant catalysts through combining physical property characterization and electrochemical tests including half-cell and single-cell. The mass activity of Pt2cu/c is 0.51 A/mgPt, exceeding the DOE's 2020 target of 0.44 A/ mgPt. After add 0.1 M H3PO4 into the HclO4 electrolyte, the half-wave potential (E1/2) of Pt2cu/c is only negatively shifted by 47 mV, much lower than 90 mV of TKK Pt/c. Furthermore, the HT-PEMFc with Pt2cu/c in the cathode shows a peak power density of 383.4 mW/cm2, which surpasses that of TKK Pt/c for 231.0 mW/cm2. Our strategy of screening catalysts based on the adsorption energy difference study and further verified by experimental methods provides a promising strategy for the design of practical electrocatalyst in the cathode of HT-PEMFcs.

关键词： Phosphoric acid resistance electrocatalysts Ptcu c ORR DFT HT-PEMFc

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Hierarchical porous VN/Nc/c nanocomposites with synergistic coupling for oxygen reduction

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JOURNAL OF ELEcTROANALYTIcAL cHEMISTRY 2023年第1期932卷

作者： Fu, Yidan Han, Lina Zheng, Pengfei Xian, Xianglan Zeng, Xiaoyuan Dong, Peng Feng, Jing Zhang, Yingjie Kunming Univ Sci & Technol Sch Mat Sci & Engn Kunming 650000 Peoples R China Univ Sci & Technol Sch Kunming Natl & Local Joint Engn Lab Lithium ion Batteries Kunming 650000 Peoples R China

Vanadium nitride (VN) with high theoretical specific capacity and electrical conductivity is promising for application in Zn-air batteries. However, the agglomeration phenomenon during the synthesis of VN nanopar-ticles resulted in poor catalytic activity. Therefore, a highly efficient and durable ORR catalyst that vanadium nitride nanoparticles supported on nitrogen-doped carbon (VN/Nc/c) was prepared by a self-assembly. Benefiting from the synergistic effect of VN and Nc as well as its large specific surface area, porous structure, abundant pyridine N and graphitic N, the VN/Nc/c nanocomposites exhibits excellent catalytic activity with Eonset of 0.87 V, a limiting current density of 4.05 mA center dot cm-2, and good stability. The experimental results and DFT calculations show that benefiting from the synergistic effect of Nc and VN, the free energies of the reaction intermediates are optimized to significantly accelerate the O2 adsorption and reduce the potential of the rate-determining step. The Zn-air battery assembled with VN/Nc/c nanocomposites exhibits an open circuit poten-tial of 1.30 V, high power density of 141.82 mW center dot cm-2 and an energy density of 856.27 Wh center dot kgZn-1 . This work demonstrates the importance of the synergistic effect of Nc and VN in the development of high-performance Zn-air batteries.

关键词： Oxygen reduction reaction VN Nc c Zn-air battery N -doped carbon

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Study of effects of corrosion temperature on corrosion resistance of cu-c alloys to liquid Ga

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cORROSION ScIENcE 2023年 211卷

作者： He, Dingjin Liu, Guangzhu Liu, Jingfu Xie, Hongyu Yue, Di chen, Zelin Wei, chong Xu, Xintong Xie, Haijiao Liaoning Tech Univ Coll Mat Sci & Engn 47 Zhonghua Rd Fuxin 123000 Liaoning Peoples R China BoHai Shipyard Grp Co Ltd 132 Jinhu Rd Huludao 125004 Liaoning Peoples R China Hangzhou Yanqu Informat Technol Co Ltd Y2 2nd FloorBldg 2Xixi Legu Creat Pioneering Pk Hangzhou 310003 Zhejiang Peoples R China

The corrosion interface characteristics and corrosion behavior of cu-c alloys in liquid Ga at 100-180 degrees c were studied in this paper. The corrosion mechanism of cu-c alloys was microscopically studied via the first-principles calculation based on the density functional theory (DFT). The results, the diffusion of Ga atoms leads to the phase transition of cu in the cu-c alloy and the generation of the corrosion product cuGa2. The corrosion rate of the cu-c alloy is related to the dissolution rate, and growth rate and exfoliation rate of corrosion product layer. c led to much better corrosion resistance of cu-c alloys.

关键词： A metal matrix composites B modelling studies c hot corrosion alloy

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Heterologous synapsis in c. elegans is regulated by meiotic double-strand breaks and crossovers

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cHROMOSOMA 2021年第4期130卷 237-250页

作者： Liu, Hanwenheng Gordon, Spencer G. Rog, Ofer Univ Utah Sch Biol Sci 257 South 1400 East Salt Lake City UT 84112 USA Univ Utah Ctr Cell & Genome Sci 257 South 1400 East Salt Lake City UT 84112 USA Washington Univ Div Biol & Biomed Sci 660 South Euclid Ave St Louis MO 63110 USA

Alignment of the parental chromosomes during meiotic prophase is key to the formation of genetic exchanges, or crossovers, and consequently to the successful production of gametes. In almost all studied organisms, alignment involves synapsis: the assembly of a conserved inter-chromosomal interface called the synaptonemal complex (Sc). While the Sc usually synapses homologous sequences, it can assemble between heterologous sequences. However, little is known about the regulation of heterologous synapsis. Here, we study the dynamics of heterologous synapsis in the nematode c. elegans. We characterize two experimental scenarios: Sc assembly onto a folded-back chromosome that cannot pair with its homologous partner;and synapsis of pseudo-homologs, a fusion chromosome partnering with an unfused chromosome half its size. We observed elevated levels of heterologous synapsis when the number of meiotic double-strand breaks or crossovers were reduced, indicating that the promiscuity of synapsis is regulated by break formation or repair. In addition, our data suggests the existence of both chromosome-specific and nucleus-wide regulation on heterologous synapsis.

关键词： c elegans Heterologous synapsis Synaptonemal complex Double-strand breaks crossover

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Hepatoprotective effect of the tyrosine kinase inhibitor nilotinib against cyclosporine-A induced liver injury in rats through blocking the Bax/cytochrome c/caspase-3 apoptotic signaling pathway

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JOURNAL OF BIOcHEMIcAL AND MOLEcULAR TOXIcOLOGY 2021年第6期35卷 1-13页

作者： Serrya, Marwa S. Nader, Manar A. Abdelmageed, Marwa E. Mansoura Univ Fac Pharm Dept Pharmacol & Toxicol Mansoura 35516 Egypt

cyclosporine-A (csA) is a powerful immunosuppressive agent and hepatotoxicity results from csA treatment. This study aimed to elucidate the effectiveness of tyrosine kinase inhibitor nilotinib against csA-induced hepatotoxicity and the underlying molecular mechanisms. Male Sprague-Dawley rats were allocated into four groups and received drugs for 28 days as follows: control group: received vehicle, Nilotinib group: received nilotinib (20 mg/kg orally), csA group: received csA by subcutaneous injection (20 mg/kg daily), csA-nilotinib: received nilotinib and csA. Serum lactate dehydrogenase (LDH), liver function biomarkers, hepatic levels of oxidative stress biomarkers, nuclear factor erythroid-2 like-2 (Nrf2), total antioxidant capacity (TAc), interleukin-2 (IL-2), IL-1 beta, IL-6, and cytochrome-c were assessed. Additionally, the protein levels and mRNA expression of Bcl2 associated X protein (Bax), caspase-3, nuclear factor-kappa B (NF-kappa B), hemoxygenase-1 (HO-1) were measured. Moreover, liver tissues were assessed histopathologically using hematoxylin-eosin and Masson trichrome stain. Nilotinib treatment decreased serum LDH, alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase (gamma-GT), hepatic malondialdehyde, and cytochrome-c. It also increased superoxide dismutase, reduced glutathione, glutathione reductase, glutathione peroxidase, glutathione-S-transferase (GST), TAc, and Nrf2 compared to csA-injected rats. In addition, nilotinib decreased NF-kappa B, IL-1 beta, IL-6, Bax, and caspase-3, while elevated IL-2 and immunoexpression of HO-1. Additionally, mRNA expression of Bax and caspase-3 was elevated and that of HO-1 and inhibitory protein kappa B-alpha was reduced in the nilotinib-treated group. Moreover, nilotinib significantly attenuated csA-induced histopathological alterations. Nilotinib may have a promising role as a hepato-protective through its antiapoptotic, antioxidant, and anti-inflammatory effects.

关键词： Bax caspase‐ 3 cyclosporine‐ A cytochrome‐ c liver injury nilotinib oxidative stress TAc

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On a Topology and Limits for Inductive Systems of c*-Algebras over Partially Ordered Sets

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INTERNATIONAL JOURNAL OF THEORETIcAL PHYSIcS 2021年第2期60卷 499-511页

作者： Gumerov, R. N. Lipacheva, E., V Grigoryan, T. A. Kazan Volga Reg Fed Univ NI Lobachevsky Inst Math & Mech Chair Math Anal Kremlevskaya 35 Kazan 420008 Russia Kazan State Power Engn Univ Chair Higher Math Krasnoselskaya 51 Kazan 420066 Russia

Motivated by algebraic quantum field theory and our previous work we study properties of inductive systems of c*-algebras over arbitrary partially ordered sets. A partially ordered set can be represented as the union of the family of its maximal upward directed subsets indexed by elements of a certain set. We consider a topology on the set of indices generated by a base of neighbourhoods. Examples of those topologies with different properties are given. An inductive system of c*-algebras and its inductive limit arise naturally over each maximal upward directed subset. Using those inductive limits, we construct different types of c*-algebras. In particular, for neighbourhoods of the topology on the set of indices we deal with the c*-algebras which are the direct products of those inductive limits. The present paper is concerned with the above-mentioned topology and the algebras arising from an inductive system of c*-algebras over a partially ordered set. We show that there exists a connection between properties of that topology and those c*-algebras.

关键词： c algebra Inductive limit Inductive system Partially ordered set Topology

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Soil c : N : P Stoichiometry as Related to Nitrogen Addition in a Meadow Steppe of Northern china

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EURASIAN SOIL ScIENcE 2021年第10期54卷 1581-1587页

作者： Wang, X. G. Wuyunna Lu, X. T. Yang, G. J. coombs, c. E. O. Du, X. Song, Y. T. Zhang, F. J. Huo, G. W. Han, X. G. Dalian Minzu Univ Coll Environm & Resources Dalian 116600 Peoples R China Chinese Acad Sci Inst Appl Ecol CAS Key Lab Forest Ecol & Management Erguna Forest Steppe Ecotone Res Stn Shenyang 110016 Peoples R China Univ Sydney Ctr Carbon Water & Food Sch Life & Environm Sci Camden NSW 2570 Australia Chinese Acad Sci Inst Bot State Key Lab Vegetat & Environm Change Beijing 100093 Peoples R China

The concentrations and stoichiometry of soil carbon (c), nitrogen (N), and phosphorus (P) have critical implications for nutrient cycling and ecosystem function. While their high sensitivity to atmospheric N deposition is well known, it remains unclear for the soil depth-dependence of such responses to N deposition. Here, we examined the responses of soil c : N : P stoichiometry at three soil depths in the upper humus horizon (0-5, 5-10, and 10-20 cm) of Haplic chernozem (Loamic) across a gradient of urea addition rates (0, 2, 10, 20, and 50 g N m(-2) year(-1)) after five years treatments in a hay-harvest meadow steppe of northern china. We found that the effects of increasing N addition rates on the concentrations and stoichiometry of soil c, N and P did not depend on soil depth, though those parameters varied greatly across different soil layers. Across all soil depths, the concentrations of soil c and N increased with increasing N addition rates, but soil P concentration was not affected by N addition. The higher sensitivity of soil N than soil c to N enrichment resulted in decreasing soil c : N ratio across the N addition gradient, especially for the surface soil layer. Soil N : P ratio showed a positive response to the increases of N addition rates. The unbalanced responses of soil c, N, and P concentrations to N enrichment, as indicated by the decreases of soil c : N ratio and the increases of soil N : P ratio across the N addition gradient, highlighted the role of N enrichment in decoupling soil nutrient cycling in the temperate steppe.

关键词： biogeochemistry c N P ratio global change nitrogen enrichment soil layer

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co-administration of toll-like receptor (TLR)-3 agonist Poly I:c with different infectious bursal disease (IBD) vaccines improves IBD specific immune response in chicken

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VETERINARY RESEARcH cOMMUNIcATIONS 2021年第4期45卷 285-292页

作者： Kannaki, T. R. Priyanka, E. Abhilash, Manda Haunshi, Santosh ICAR Directorate Poultry Res Avian Hlth Lab Hyderabad 500030 Telangana India PV Narsimha Rao Telangana Vet Univ Dept Vet Microbiol Hyderabad 500030 India

Toll-like receptor (TLR) agonists are emerging as promising vaccine adjuvants and immunomodulators in poultry against many diseases. Infectious bursa disease (IBD) still remains as a major threat to poultry industry. Improving the vaccine mediated immune response would help in better protection against IBD virus infection. Adjuvant potential of TLR3 agonist, Polinosinic polycytidylic acid (Poly I:c) with different IBD vaccines has been analyzed in chicken in the present study. Intermediate, intermediate plus IBD vaccine, bursaplex vaccine and their respective poly I:c combinations were used for immunization of chicken. IBD specific antibody titers, bursa to body weight ratio, body weight gain and bursal lesion scores were evaluated at weekly interval in different immunization groups. Fold changes in cytokines IL-1 beta and IFN-gamma mRNA expression levels in spleen were also analyzed in different groups. Intermediate plus IBD vaccine induced significantly (P <= 0.05) higher IBD specific antibody response at 35 days of age than other groups with comparatively lower body weight gain and moderate bursal lesion score. Poly I:c co-administration with intermediate IBD vaccine and bursaplex vaccine improved the IBD specific antibody titers, better body weight gain and moderately less bursal lesion score. However, Poly I:c combination with intermediate plus IBD vaccine did not improve the specific immune response. IL-1 beta levels were up-regulated in intermediate plus and bursaplex group, whereas IFN-gamma m RNA expression levels were upregulated in intermediate IBD with Poly I:c group. In conclusion, poly I:c co-administration with intermediate IBD and bursaplex vaccine was beneficial and improved the specific immune response with least immunosuppression and bursal damage.

关键词： IBD vaccines Poly I c TLR3 agonist chicken

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Ti3c2/g-c3N4异质结复合光催化剂研究进展

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化工新型材料 2025年

作者：李苗李欣儒武威周远西安石油大学新能源学院西安石油大学党委宣传部西安市自来水有限公司

石墨相碳化氮(g-c3N4)作为最有潜力之一的光催化剂广泛应用于光催化制氢、cO2还原、水中污染物降解以及挥发性有机化合物去除等方面，然而，如何加速电荷转移和提高光生电子-空穴对的分离效率是亟待解决的问题。利用其他二维（2D）材料... 详细信息

石墨相碳化氮(g-c3N4)作为最有潜力之一的光催化剂广泛应用于光催化制氢、cO2还原、水中污染物降解以及挥发性有机化合物去除等方面，然而，如何加速电荷转移和提高光生电子-空穴对的分离效率是亟待解决的问题。利用其他二维（2D）材料对2D g-c3N4纳米片进行改性，通过构建2D/2D异质结来抑制电荷载流子复合，可以提高其分离效率。综述了2D碳化钛(Ti3c2)材料与g-c3N4纳米片复合构建异质结的制备方法、作用机理以及在光催化析氢、有机物降解等领域的应用。

关键词： Ti c g-c N 2D/2D异质结改性光催化

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Ablation behaviors and mechanism of Zrc-Sic-Si/Sic-Si double-layered coatings on c/c composite under plasma flame at 3000 °c

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cORROSION ScIENcE 2023年第1期218卷

作者： Wang, Yuqi Guo, Lingxiang Zhang, Yuyu Zhang, Xuemeng Ou, Hongkang Sun, Jia Northwestern Polytech Univ Shaanxi Key Lab Fiber Reinforced Light Composite M State Key Lab Ultra High Temp Composite Mat Xian 710072 Peoples R China Natl Univ Def Technol Sci & Technol Adv Ceram Fibers & Composites Lab Changsha 410073 Peoples R China

To improve the ablation performance of c/c composite at 3000 degrees c, a Zrc-Sic-Si/Sic-Si double-layered coatings (ZSS/SS) was prepared by slurry dipping-carbonization and gaseous silicon infiltration. During ablation, a competition between mechanical denudation and oxidation derived thickening occurred. The ZSS/SS coating possessed a superior ablation resistance showing lowest linear ablation rate of 0.53 mu m/s in 90 s with a parabolic rate constant Kp (0.053 mu m/s3). The excellent performance was attributed to good self-sealing of oxidation derived glassy, thus no micro-cracks were observed. However, the Kp became worse to be 0.131 for long-term ablation because of dominant mechanical denudation.

关键词： c c composites Polymer derived ceramic ceramic coating Ablation resistance

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