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Pico-Kelvin thermometry and temperature stabilization using a resonant optical cavity

OPTICS EXPRESS 2017年第4期25卷 3578-3593页

作者： Tan, Si wang, suwen Saraf, Shailendhar Lipa, John A. Stanford Univ Dept Mech Engn 440 Escondido Mall Stanford CA 94305 USA Stanford Univ Hansen Expt Phys Lab 452 Lomita Mall Stanford CA 94305 USA Hainan Trop Ocean Univ Hainan 572022 Peoples R China SN&N Elect Inc Santa Clara 95050 CA USA Stanford Univ Dept Phys 382 Via Pueblo Mall Stanford CA 94305 USA

Ultra-high sensitivity temperature sensing and stable thermal control are crucial for many science experiments testing fundamental theories to high precision. Here we report the first pico-kevin scale thermometer operating at room temperature with an exceptionally low theoretical noise figure of similar to 70 pK/root Hz at 1 Hz and a high dynamic range of similar to 500 K. We have experimentally demonstrated a temperature sensitivity of < 3 : 8 nK /root Hz at 1 Hz near room temperature, which is an order of magnitude improvement over the state of the art. We have also demonstrated an ultra-high stability thermal control system using this thermometer, achieving 3 : 7 nK stability at 1 s and similar to 120 pK at 10(4) s, which is 10-100 times more stable than the state of the art. With some upgrades to this proof-of-principle device, we can expect it to be used for very high resolution tests of special relativity and in critical point phenomena.

关键词： Laser sources Phase modulation Power spectral density Reflection coefficient Temporal resolution Whispering gallery modes

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Two-dimensional closely packed amide polyphthalocyanine iron absorbed on Vulcan XC-72 as an efficient electrocatalyst for oxygen reduction reaction

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CATALYSIS TODAY 2020年 353卷 279-286页

作者： Sun, Chongyun Li, Zhongfang Yang, Jianwei wang, suwen Zhong, Xizhan wang, Likai Shandong Univ Technol Sch Chem & Chem Engn Zibo 255049 Peoples R China

It is crucial to design the inexpensive and highly efficient electrocatalysts for oxygen reduction reaction (ORR) for the future commercialization of fuel cell devices. Herein, a closely packed amide polyphthalocyanine iron (CPMPcFe) with two-dimensional planar structure supported by Vulcan XC-72 was firstly prepared, and then the precursor was sintered at 400 degrees C under an Ar flow to obtain the CPMPcFe/C (1:1) catalyst. The SEM and TEM images of the CPMPcFe/C catalysts confirmed that CPMPcFe was well distributed on the surface of Vulcan XC-72. X-ray photoelectron spectroscopy (XPS) further identified the active center of CPMPcFe/C (1:1, 400 degrees C) was FeN4 in the polyphthalocyanine ring. Electrochemically, CPMPcFe/C displays excellent oxygen reduction reaction electrocatalytical properties. Firstly, it showed a half-wave potential of 0.87 V, which was more positive than those of iron phthalocyanine/C (FePc/C, 0.71 V) and 6 wt% Pt/C (0.83 V). The oxygen reduction current loss of CPMPcFe/C after 5000-cycle cyclic voltammetry test was 0.05 mA cm(-2), while that of FePc/C was 0.35 mA cm(-2). Chronoamperometry tests showed that FePc/C exhibited a rapid decrease of the current density by about 28.2%, while there was only about 16.9% loss for the current density of CPMPcFe/C under the same operation.

关键词： Oxygen reduction reaction Electrocatalysts Polyphthalocyanine iron The durability

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Comment on "Mineralization age of the Xiangshan uranium ore field, South China redefined by hydrothermal apatite U-Pb geochronology" by wang et al., (Ore Geology Reviews, 2023, https://***/10.1016/j. oregeorev.2023.105586)

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ORE GEOLOGY REVIEWS 2025年 180卷

作者： Zhu, suwen Li, Guangrong wang, Yun Guo, Fusheng Qin, Ao East China Univ Technol Natl Key Lab Uranium Resources Explorat Min & Nucl Nanchang 330013 Peoples R China East China Univ Technol State Key Lab Nucl Resources & Environm Nanchang 330013 Peoples R China

Recently,wang et al., (2023) published their apatite U-Pb ages from Xiangshan uranium ore field, South China and concluded that uranium mineralization age is synchronously formed to the hosting rock. This conclusion presents a significant departure from traditional views and offers novel insights into the timing of uranium mineralization. This paper raises evidence based on our research results in Xiangshan area in the past decade. Firstly, field observations indicate that uraniferous veins cut the well crystallized volcanic complex, suggesting a later hydrothermal event. Additionally, the synchronicity of apatite formation with uranium enrichment is questioned, as type 2 apatite crystals show complex relationships with uranium minerals. Discrepancies in previous U-Pb dates on U-minerals and Ar-Ar dates are discussed as well, and the result suggests that the age of volcanic complex hosting uranium minerals is mainly concentrated between 130 and 145 Ma, and the time difference between mineralization and diagenesis varies greatly. The paper emphasizes the need to reconcile the differences between various dating methods to accurately determine the mineralization age.

关键词： Uranium mineralization Hydrothermal apatite Xiangshan uranium ore field Geochronology discrepancies

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Construction of proton channels and reinforcement of physicochemical properties of oPBI/FeSPP/GF high temperature PEM via building hydrogen bonding network

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2017年第21期42卷 14572-14582页

作者： Sun, Peng Li, Zhongfang Jin, Lei wang, suwen Yin, Xiaoyan Shandong Univ Technol Sch Chem Engn Zibo 255049 Peoples R China

Composite high temperature proton exchange membranes (HT-PEMs) comprising poly[4,4'(diphenyl ether)-5,5'-bibenzimidazole] (oPBI), ferric sulfophenyl phosphate (FeSPP) and glass fiber (GF) were prepared by the hot-pressing method. Doping FeSPP as a novel insoluble proton conductor not only provided good proton conductivity at high temperature but also enhanced their methanol blocking property, dimensional stability and oxidative resistance. Good dispersion, construction of proton channels and reinforcement of the physicochemical properties were achieved by building hydrogen bonding network among oPBI, FeSPP and GF. After incorporation of 3wt% GF into the oPBI/FeSPP(30wt%) composite membrane, the tensile strength was enhanced by 370% while the swelling ratio reduced to around 55%. The oxidative stability and methanol resistance were also enhanced while the proton conductivity was slightly affected. The membranes were thermally stable in the working temperature range for HT-PEM fuel cells. The proton conductivity of oPBI/FeSPP(30wt%) and oPBI/FeSPP(30wt%)/GF(3wt%) membranes reached 0.089 and 0.074 S cm(-1) at 180 degrees C and 100% relative humidity, respectively. At 180 degrees C, the proton conductivity of oPBI/FeSPP(30wt%) and oPBI/FeSPP(30wt%)/GF(3wt%) was 0.052 and 0.042 S cm(-1) at 50% RH, respectively. oPBI/FeSPP(30wt%)/GF(3wt%) exhibited good selectivity of 3.84 x 10(5) S s cm(-3) indicating good potential for applications in direct methanol fuel cells. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： High temperature proton exchange membrane Poly[4,4 '-(diphenylether)-5,5 '-bibenzimidazole] Ferric sulfophenyl phosphate Glass fiber Hydrogen bond

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Comprehensive performance enhancement of polybenzimidazole based high temperature proton exchange membranes by doping with a novel intercalated proton conductor

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2018年第21期43卷 9994-10003页

作者： wang, suwen Sun, Peng Li, Zhongfang Liu, Guohong Yin, Xiaoyan Shandong Univ Technol Sch Chem & Chem Engn Zibo 255049 Peoples R China

On the study of high temperature proton exchange membrane (HTPEM), the trade-off between proton conductivity and physico-chemical property (such as mechanical strength, dimensional stability and methanol resistance) remained a main obstacle for comprehensive performance enhancement. To address this issue, novel HTPEM was prepared by doping phosphotungstic acid intercalated ferric sulfophenyl phosphate (FeSPP-PWA) into polybenzimidazole (PBI) via hot pressed method. Intense hydrogen bonding network was built between PBI and FeSPP-PWA, rendering construction of proton channels and reinforcement of physico-chemical property. As a novel proton conductor, FeSPP-PWA facilitated formation of efficient proton transfer pathway. The layered morphology and inorganic intrinsity of FeSPP-PWA also improved the mechanical and dimensional stability while reducing the methanol permeability of the PBI/FeSPP-PWA membranes. The composite membrane exhibited good thermal stability up to 200 degrees C. The proton conductivity of PBI/FeSPP-PWA (30 wt%) reached 110 mS cm(-1) at 170 degrees C and 100% RH, and was 69.3 mS cm(-1) at 180 degrees C and 50% RH. The PBI/FeSPP-PWA also showed low methanol permeability and high membrane selectivity for application in direct methanol fuel cells. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： High temperature proton exchange membrane Polybenzimidazole Hydrogen bonding network Intercalated proton conductor Proton conductivity

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Preparation and properties of medium temperature membranes based on zirconium sulfophenylphosphate/sulfonated poly(phthalazinone ether sulfone ketone) for direct methanol fuel cells

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JOURNAL OF MEMBRANE SCIENCE 2010年第1-2期351卷 50-57页

作者： Li, Zhongfang Dong, Feilong Xu, Lijuan wang, suwen Yu, Xianjin Shandong Univ Technol Sch Chem Engn Zibo 255049 Shandong Peoples R China

Novel polymer composite membranes composed of sulfonated poly(phthalazinone ether sulfone ketone) (SPPESK) and inorgano-organic zirconium sulfophenyl phosphate (ZrSPP) were prepared by solution casting. Three ZrSPP concentrations were used: 10, 20 and 30 wt%. The degrees of sulfonation (DS) of SPPESK were 34.6% and 76%. The DS of ZrSPP was 95%. Membranes were characterized by infrared spectroscopy (IR), X-ray diffraction spectroscopy (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). IR results indicated intense hydrogen bonds formed between ZrSPP and SPPESK molecules. SEM micrographs showed that ZrSPP mixed well with SPPESK and formed dense structures. The proton conductivity of the 10 wt% SPPESK (DS 76%)/ZrSPP composite membrane reached 0.393 S/cm at 120 degrees C and that of the 30 wt% of SPPESK (DS 34.6%)/ZrSPP composite membrane reached 0.23 S/cm at 160 degrees C and 100% relative humidity (RH). Proton conductivities of the SPPESK/ZrSPP composite membranes were better than that of the Nafion (R) 117 membrane in the temperature range of 80-160 degrees C. The methanol permeabilities of the SPPESK/ZrSPP composite membranes were in the range of 1.9 x 10(-8) to 0.15 x 10(-8) cm(2)/s, much lower than that of Nafion (R) 117 (2.4 x 10(-6) cm(2)/s). The composite membranes exhibited good thermal stabilities, proton conductivities, and good methanol resistance properties. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Direct methanol fuel cells Composite membrane Medium temperature proton exchange membrane Zirconium sulfophenyl phosphate Sulfonated poly(phthalazinone ether sulfone ketone)

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Spinel MnCo₂O₄ Nanoparticles Supported on Three-Dimensional Graphene with Enhanced Mass Transfer as an Efficient Electrocatalyst for the Oxygen Reduction Reaction

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CHEMSUSCHEM 2018年第16期11卷 2730-2736页

作者： Zhang, Tingwei Li, Zhongfang wang, Likai Sun, Peng Zhang, Zhixu wang, suwen Shandong Univ Technol Sch Chem & Chem Engn 266 Xincun West Rd Zibo 255049 Shandong Peoples R China

The rational design of highly efficient and durable oxygen reduction reaction (ORR) catalysts is critical for the commercial application of fuel cells. Herein, three-dimensional graphene (3D-G) is synthesized by the template method, which used coal tar pitch as the carbon source and nano MgO as the template. Then, spinel MnCo2O4 is in situ supported on the 3D-G by a facile hydrothermal method, giving MnCo2O4/3D-G. The resultant MnCo2O4/3D-G retains the multilayered mesoporous graphene structure where MnCo2O4 nanoparticles are deposited on the inner walls of pores in the 3D-G. The catalyst MnCo2O4/3D-G shows high electrocatalytic activity with a half-wave potential of 0.81V versus reversible hydrogen electrode, which is clearly superior to those of MnCo2O4/reduced graphene oxide (0.78V), MnCo2O4/carbon nanotubes (0.74V), MnCo2O4/C (0.72V), and 20wt% Pt/C (0.80V). The electron transfer number of MnCo2O4/3D-G indicates a four-electron process of ORR. The durability test demonstrates that the MnCo2O4/3D-G catalyst has a much better durability than 20wt% Pt/C. Our work makes an inspiring strategy to prepare high-performance electrocatalysts for the development of fuel cells.

关键词： fuel cells hydrothermal method oxygen reduction reaction spinel MnCo2O4 three-dimensional graphene

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A novel cathode catalyst for aluminum-air fuel cells: Activity and durability of polytetraphenylporphyrin iron (II) absorbed on carbon black

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2014年第35期39卷 20171-20182页

作者： Xu, Shihua Li, Zhongfang Ji, Yanfeng wang, suwen Yin, Xiaoyan wang, Yuxin Shandong Univ Technol Sch Chem Engn Zibo 255049 Peoples R China Tianjin Univ Sch Chem Engn State Key Lab Chem Engn Tianjin 300072 Peoples R China

A polytetraphenylporphyrin iron (II) (PTPPFe) oxygen reduction reaction (ORR) catalyst for aluminum-air fuel cells (AAFCs) is prepared. Thermogravimetric analysis results show that PTPPFe is stable at temperatures below 600 degrees C. X-ray photoelectron spectroscopy reveals that the active site of PTPPFe/C is Fe-N-4 in the porphyrin ring. Rotating disk electrode measurements in 1 mol L-1 NaOH solution demonstrate that the initial potential for ORR is 0.142 V vs. Hg/HgO/OH- (1 mol L-1 KOH, 0.098 V vs. NHE) at 20 degrees C, and that ORR mainly occurs through a four-electron process. The half-wave potentials for PTPPFe/C and the Pt/C catalyst are 0.071 and 0.079 V, respectively. Almost no performance degradation is observed over continuous cyclic voltammetry at 10 000 cycles, linear sweep voltammetry at 200 cycles, and 60 h of chronoamperometry test. After durability tests, the ultraviolet visible spectrum of PTPPFe does not change from the initial characteristics. The discharge performance of AAFC has a power density of 47.5 mW cm(-2) at 20 degrees C in 6 mol L-1 NaOH electrolyte solution. During continuous discharge for 10 h, the potential of AAFC decreases by less than 0.01 V at 40 mA cm(-2). Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Aluminum-air fuel cells Air electrode Polytetraphenylporphyrin iron Oxygen reduction reaction Durability

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Hydrothermal synthesis of hierarchical zeolite T aggregates using tetramethylammonium hydroxide as single template

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MICROPOROUS AND MESOPOROUS MATERIALS 2015年第C期201卷 247-257页

作者： Yin, Xiaoyan Li, Zhongfang wang, suwen Chu, Naibo Yang, Jianhua wang, Jinqu Shandong Univ Technol Sch Chem Engn Zibo 255049 Peoples R China Cent Res Inst Yantai WH Polyurethane Co Ltd Yantai 264002 Peoples R China Dalian Univ Technol Sch Chem Engn Dalian 116012 Peoples R China

In this paper, the hierarchical zeolite T aggregates with different sizes have been successfully synthesized by hydrothermal method with the aid of single template (tetramethylammonium hydroxide, TMAOH). The products have been studied in detail by XRD, SEM, TEM and N-2 adsorption-desorption techniques. The influences of the preparation parameters including the amounts of TMAOH and water, crystallization temperature, pre-crystallization, seeding and aging on the synthesis of zeolite T aggregates have been investigated thoroughly. The synthesized samples typically display the column-like aggregates consisted of tightly packed primary nanocrystal grains. The additional mesopores of samples are attributed to the interstitial voids existing between the nanocrystals. The decreased crystallization temperature, pre-crystallization, seeding and aging disposals can reduce the particle sizes and improve the mesoporous properties of zeolite T aggregates. Among all the prepared samples, zeolite T sample which first statically aged at room temperature for 48 h and then synthesized at 373 K for 48 h had the highest BET surface area (S-BET) of 461 m(2)/g and mesopore volume (V-meso) of 0.231 cm(3)/g. This paper provides an efficient and facile route to prepare hierarchical zeolite T aggregates. (C) 2014 Elsevier Inc. All rights reserved.

关键词： Zeolite T Mesoporous zeolite Hierarchical structure Single template

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High temperature proton exchange membranes based on cerium sulfophenyl phosphate doped polybenzimidazole by end-group protection and hot-pressing method

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2017年第1期42卷 486-495页

作者： Sun, Peng Li, Zhongfang Dong, Feilong wang, suwen Yin, Xiaoyan wang, Yuxin Shandong Univ Technol Sch Chem Engn Zibo 255049 Peoples R China Tianjin Univ Sch Chem Engn State Key Lab Chem Engn Tianjin 300072 Peoples R China

Cerium sulfophenyl phosphate (CeSPP) doped polybenzimidazole (PBI) composite membranes were prepared by hot-pressing method as promising candidates for high temperature proton exchange membranes. In order to improve the oxidative stability of the composite membrane (PBI/CeSPP), the active vicinal diamino groups on polymer ends were protected by transformation into benzimidazolones. It was found that the membranes prepared from end-group protected PBI (e-PBI) had an evidently enhanced oxidative stability in comparison with the membrane made from unprotected PBI (u-PBI). CeSPP was found to be well dispersed in the polymer matrix due to its organic-inorganic nature and the strong ionic/hydrogen bonding between PBI and it. The composite membrane exhibited good mechanical strength and thermal stability up to 200 degrees C. The temperature and relative humidity dependence of the proton conductivity was investigated. The proton conductivity of e-PBI/CeSPP (25 wt%) at 180 degrees C reached 0.11, 0.039 and 0.0024 S cm(-1) at 100%, 50% and 0 relative humidity, respectively. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： High temperature proton exchange membrane Composite membrane Polybenzimidazole Cerium sulfophenyl phosphate End-group protection

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