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A kinetic study and factor analysis of solar thermochemical membrane reactors for syngas production

Science China Technological Sciences 2025年第1期 207-221页

作者： Jiaxin xing Chao xu Xiangyu SUN Xin XIA Fei JIN Qiongqiong JIANG Jiale GAO Key Laboratory of Power Station Energy Transfer Conversion and System of MOE School of Energy Power and Mechanical EngineeringNorth China Electric Power University Department of Chemistry University College London School of Chemistry and Chemical Engineering Ningxia Key Laboratory of Solar Chemical Conversion TechnologyState Ethnic Affairs CommissionNorth Minzu University

Solar thermochemical conversion technologies are promising for effectively utilizing solar energy by capturing the full spectrum of solar radiation. To overcome the challenges of low energy conversion efficiency and intermittency faced by solar thermochemical conversion, these technologies can be effectively integrated with membrane reactor technology. Although the performance of solar thermochemical membrane reactors has been experimentally tested, the chemical reactions and oxygen transport mechanisms during the energy conversion process remain poorly understood. This study introduces a resistance network model to elucidate the interactions between interfacial reactions and bulk diffusion during simultaneous oxidationreduction reactions on both sides of the membrane. We analyzed the oxygen flux of the membrane reactor under various operating conditions using this model to identify the reaction/transport-limiting side of the overall process. The most effective solar membrane reactor configuration utilizes natural gas and CO2, facilitating clean conversion of fossil fuels with significant advantages in fuel production and energy efficiency. Introducing CH4lowers the overall reaction temperature, maintains low oxygen partial pressure on the sweep side, and produces a synthesis gas with a 2:1 H2/CO molar ratio. Finally, a sensitivity analysis was used to explore the relationship between overall fuel production performance and operational parameters,highlighting the critical role of this research in enhancing the reaction and transport performance of membrane reactors and advancing the development of solar-driven thermochemical fuel production technologies.

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Shear-thinning behavior of the CaO–SiO2–CaF2–Si3N4 system mold flux and its practical application

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International Journal of Minerals,Metallurgy and Materials 2017年第10期24卷 1096-1103页

作者： ying xu Zhi-peng Yuan Li-guang Zhu yi-hua Han xing-juan Wang Hebei Provincial Key Laboratory of Inorganic Nonmetallic Materials College of Materials Science and Engineering North China University of Science and Technology Tangshan 063009 China Key Laboratory for Advanced Metallurgy Technology Hebei Provincial High-Quality Steel Continuous Casting Engineering Technology Research Center College of Metallurgy & Energy North China University of Science and Technology Tangshan 063009 China

Satisfying the mold-flux performance requirements for high-speed continuous casting necessitates the development of a new non-Newtonian-fluid mold flux with shear-thinning behavior, i.e., a mold flux whose viscosity is relatively high under lower shear rates and relatively low under higher shear rates. In this work, a mold flux that exhibits shear-thinning behavior was developed by adding different amounts of Si_3N_4 to the CaO–SiO_2–CaF_2 mold flux. The shear-thinning behavior was investigated using a rotational viscometer. In addition, the microstructure of the newly prepared slags was studied by high-temperature Raman spectroscopy and X-ray photoelectron spectroscopy. The results showed that the mechanism of shear-thinning was attributable to a temporary viscosity loss caused by the one-way shear stress, whereas the corresponding magnitude of shear-thinning was closely related to the degree of polymerization(DP). Finally, the non-Newtonian fluid mold flux was used for laboratory casting tests, which revealed that the mold flux could reduce slag entrapment and positively affect the continuous casting optimization.

关键词： mold flux viscosity shear-thinning behavior non-Newtonian fluid degree of polymerization

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Evaluation of spectral domain optical coherence tomography parameters in discriminating preperimetric glaucoma from high myopia

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International Journal of Ophthalmology(English edition) 2019年第1期12卷 58-65页

作者： Xiao-Yu xu Hui Xiao Jing-yi Luo xing Liu State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen University

AIM: To evaluate the diagnostic ability of macular ganglion cell-inner plexiform layer(GCIPL) thickness o b t a i n e d b y s p e c t r a l-d o m a i n o p t i c a l c o h e r e n c e tomography(SD-OCT) in discriminating non-highly myopic eyes with preperimetric glaucoma(PPG) from highly myopic healthy eyes. METHODS: A total of 254 eyes, including 76 normal controls(NC), 116 eyes with high myopia(HM) and 62 non-highly myopic eyes with PPG were enrolled. The diagnostic ability of OCT parameters was accessed by the areas under the receiver operating characteristic(AUROC) curve in two distinguishing groups: PPG eyes with nonglaucomatous eyes including NC and HM(Group 1), and PPG eyes with HM eyes(Group 2). Differences in diagnostic performance between GCIPL and RNFL parameters were evaluated. RESULTS: The minimum(AUROC curve of 0.782), inferotemporal(0.758) and inferior(0.705) GCIPL thickness were the top three GCIPL parameters in discriminating PPG from non-glaucomatous eyes, all of which had statistically significant lower diagnostic ability than average RNFL thickness(0.847). In discriminating PPG from HM, the best GCIPL parameter was minimum(0.689), statistically significant lower in diagnostic ability than average RNFL thickness(0.789) and three other RNFL thickness parameters of temporal and inferotemporal clock-hour sectors. CONCLUSION: The minimum GCIPL thickness is the best GCIPL parameter to detect non-highly myopic PPG from highly myopic eyes, whose diagnostic ability is inferiorto that of average RNFL thickness and RNFL thickness of several temporal and inferotemporal clock-hour sectors. The average RNFL thickness is recommended for discriminating PPG from highly myopic healthy eyes in current clinical practice in a Chinese population.

关键词： ganglion cell-inner plexiform layer diagnostic ability preperimetric glaucoma high myopia.

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Routing protocol based on social characteristics for opportunistic networks

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The Journal of China Universities of Posts and Telecommunications 2014年第1期21卷 67-73,103页

作者： CHENG Gang SONG Mei ZHANG Yong xing yi-hai BAO xu-yan School of Electronic Engineering Beijing University of Posts and Telecommunications Potevio Institute of Technology company Limited

Opportunistic networks are derived from delay tolerant networks, where mobile nodes have no end-to-end connections. Nodes are represented by people, which means that opportunistic networks can be regarded as social networks. Human mobility plays an important role in affecting the performance of forwarding protocols in social networks, furthermore, the trajectory of people＇s movements are driven by social characteristics. However, current routing protocols rely on simple mobility models, and rarely consider social characteristics. Considering two heterogeneous network models, an social opportunistic networks routing（SONR） was proposed which brings an adapted discrete Markov chain into nodes＇ mobility model and calculates the transition probability between successive status. Comparison was made between Spray, Wait and Epidemic protocol. Simulation show that SONR can improve performance on delivery ratio, delivery latency and network overhead, meanwhile. SONR approaches the performance of Epidemic routing.

关键词： opportunistic networks delay tolerant networks social characteristics Markov chain transition probability

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In vitro induction and differentiation of umbilical cord mesenchymal stem cells into neuron-like cells by alltrans retinoic acid

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International Journal of Ophthalmology(English edition) 2015年第2期8卷 250-256页

作者： Wei Jin Yao-Peng xu An-Huai Yang yi-Qiao xing Eye Center Renmin Hospital of Wuhan University Department of Urology Wuhan General Hospital of Guangzhou Military Command

AIM: To determine the optimal concentration for inducing the differentiation of human umbilical cord-derived mesenchymal stem cells(h UC-MSCs) into neuron-like cells, although it is understood that all-trans retinoic acid(ATRA) regulates cell proliferation in the nervous system by modulating the balance between mitosis and ***: The abilities of ATRA to promote apoptosis as well as neural differentiation were assessed in cultured h UC-MSCs by morphological observation, MTT assay, annexin V-FITC/PI flow cytometry and ***: The data showed that low concentrations of ATRA(0.5 μmol, 0.25 μmol) had no effect on the number of cells. However, treatment with 1.0 μmol or 2.0 μmol ATRA induced a 24.16% and 52.67% reduction in cell number, respectively, compared with vehicle-treated cultures. Further, 4.0 μmol ATRA had a potent effect on cell number, with almost no adherent cells recovered after 24 h. We further showed that 0.5 μmol ATRA caused these cells to express characteristic markers of neuronal progenitor ***: Taken together, we conclude that ATRA has a dose-dependent influence on the neural differentiation and apoptosis of h UC-MSCs. These findings have implications on the use of ATRA-differentiated h UC-MSCs for the study of neural degeneration diseases.

关键词： human umbilical cord mesenchymal stem cells differentiation apoptosis neuron-like cells

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International Journal of Ophthalmology(English edition) 2018年第11期11卷 1842-1847页

作者： Hui Xiao Xiao-Yu xu yi-Min Zhong xing Liu State Key Laboratory of Ophthalmology Zhongshan Ophthalmic Center Sun Yat-sun University

AIM： To investigate the variation in the central lamina cribrosa thickness（cLCT）, and the central anterior lamina cribrosa surface depth（cALCSD）, as well as the central prelaminar tissue thickness（cPLTT） related to age in healthy Chinese ***： A total of 96 eyes from 96 Chinese healthy subjects were recruited. According to age, the 96 cases were divided into three groups： the young group（YG, 18-39 y）, middle-age group（MG, 40-59 y） and older-age group（OG, 60 y and above）. Lamina cribrosa images were obtained from all participants using radial linear protocol by enhanced depth imaging spectral-domain optical coherence tomography. The cLCT, cALCSD and cPLTT were calculated from the average value of the lamina cribrosa thickness, anterior lamina cribrosa surface depth and prelaminar tissue thickness in the optic nerve head（ONH） centre point and paracentral points（150 μm from the centre point in the horizontal and vertical directions）. RESULTS： For the total subjects, the mean cLCT, c ALCSD and cPLTT were 235.18±41.27, 358.02±93.80 and 182.02±92.11 μm, respectively. No statistically significant differences in cLCT, cALCSD or cPLTT were found between gender and different eyes（P=0.27-0.92）. The cLCT of the OG was the thickest among the three groups, while the c PLTT of the YG was the thickest among the three groups（P〈0.05）. Age was positively correlated with cLCT（r=0.42, P〈0.001）, and negatively correlated with cPLTT（r=-0.24, P=0.02）. No significant correlation was found between the age and cALCSD（r=-0.06, P=0.55）. And no correlation has been found between axial length and cLCT, cALCSD and c PLTT（P=0.11-0.81）.CONCLUSION： The impact of age on the cLCT and the cPLLTT should be taken into account when analysing glaucoma and other diseases related to lamina cribrosa.

关键词： lamina cribrosa thickness normal subjects optical coherence tomography age

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Mosaic evolution in birds:brain *** apparatus

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Science Bulletin 2018年第13期63卷 812-813页

作者： xing xu Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of Sciences Center for Excellence in Life and Paleoenvironment Chinese Academy of Sciences

Tracing the evolutionary sequence of major characteristics among various groups of organisms,and deciphering the interaction between the pattern of development and function of major biological structures are among the primary tasks in evolutionary *** this regard,recent significant advances have been made in bird evolution,but controversial issues and an incomplete understanding of avian evolution still remain[1,2].In the May 3,

关键词：进化生物学马赛克鸟仪器大脑生物结构有机体不完全

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Feather evolution: looking up close and through deep time

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Science Bulletin 2019年第9期64卷 563-564页

作者： xing xu Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology & PaleoanthropologyChinese Academy of Sciences Center for Excellence in Life and Paleoenvironment Chinese Academy of Sciences

The last two decades have witnessed significant advances in our understanding of the evolution of major avian characteristics(1–6)In particular, the spectacular discoveries of fossilized feathered dinosaurs from China and elsewhere have provided key insights into feather evolution (1,2)These fossils indicate that many non-avialan dinosaurs were feathered animals just like living birds.

关键词： looking up close and through deep time

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N-苄基苦参醇桂皮酸酯的合成

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安徽化工 2011年第4期37卷 47-48,51页

作者：杨琦胡钟伊兴旭何黎琴李全安安徽中医学院药学院安徽省现代中药重点实验室安徽合肥230031 解放军532医院药剂科安徽黄山245000

目的:合成N-苄基苦参醇桂皮酸酯并优化其合成工艺。方法:以苦参碱为原料,通过碱水解开环,氯苄苄基化得到N-苄基苦参酸苄酯,再经四氢铝锂还原得到N-苄基苦参醇,最后在EDAC脱水剂作用下与桂皮酸缩合,得到目标物N-苄基苦参醇桂皮酸酯。结论... 详细信息

目的:合成N-苄基苦参醇桂皮酸酯并优化其合成工艺。方法:以苦参碱为原料,通过碱水解开环,氯苄苄基化得到N-苄基苦参酸苄酯,再经四氢铝锂还原得到N-苄基苦参醇,最后在EDAC脱水剂作用下与桂皮酸缩合,得到目标物N-苄基苦参醇桂皮酸酯。结论:设计合成的N-苄基苦参醇桂皮酸酯收率达60.2%,产物的化学结构经TLC、IR、MS、1H-NMR等确证。

关键词：苦参碱桂皮酸合成

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New Construction of Complex Manifold via Conifold Transition

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1347-1368页

作者： Jin xing xu School of Mathematical Sciences Peking University

For a generic anti-canonical hypersurface in each smooth toric Fano 4-fold with rank 2 Picard group, we prove there exist three isolated rational curves in it. Moreover, for all these 4-folds except one, the contractions of generic anti-canonical hypersurfaces along the three rational curves can be deformed to smooth threefolds which is diffeomorphic to connected sums of S3 ~ S~. In this manner, we obtain complex structures with trivial canonical bundles on some connected sums of S^3 × S^3. This construction is an analogue of that made by Friedman [On threefolds with trivial canonical bundle. In： Complex Geometry and Lie Theory, volume 53 of Proc. Sympos. Pure Math., Amer. Math. Soc., Providence, RI, 1991, 103-134], Lu and Tian [Complex structures on connected sums of S^3× S^3. In： Manifolds and Geometry, Pisa, 1993, 284 293] who used only quintics in P^4.

关键词： Calabi Yau threefolds conifold transitions complex structures on connected sums of S^3× S^3

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