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Single molecule electro-catalysis of non-fluorescent molecule

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Chinese Chemical Letters 2015年第12期26卷 1514-1517页

作者： Fei-Fei Li Jun-Nan Gu xiao-chun zhou Division of Advanced Nanomaterials Suzhou Institute of Nano-tech and Nano-bionics Chinese Academy of Sciences

Single molecule catalysis is very powerful in revealing catalytic mechanism at the single molecule *** fluorescent molecule is always necessary to take part into the catalysis directly in previous *** order to study the single molecule electro-catalysis of non-fluorescent molecule（SMECNFM） on nanocatalyst, we couple the SMECNFM with a single molecule fluorescence reaction. A certain number of fluorescent molecules will be generated and detected when the SMECNFM happens. Through this method, we can detect the electro-oxidation reaction of one HCOONa molecule. The stability of Pt nanocatalyst supported on active carbon is studied at the single molecule level by this method. This paper also provides a general way to make ultra-sensitive sensor, and to study the SMECNFM for the molecules,such as formic acid, hydrogen, oxygen, etc., on single nanoparticle.

关键词： catalysis powerful reactant silica stoichiometric detecting camera slide redox revealing

Experimental study on motion and mechanical characteristics of the vertical wheel in the rock-breaking process

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Petroleum Science 2023年第1期20卷 495-506页

作者： Yan Yang Ying-Xin Yang Hai-Tao Ren Qing-Liang Qi Ze-Quan Huang chun-xiao zhou International Faculty of Applied Technology Yibin UniversityYibinSichuan 644000China College of Mechanical and Electrical Engineering Southwest Petroleum UniversityChengduSichuan 610500China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengduSichuan 610500China Faculty of Intelligence Manufacturing Yibin UniversityYibinSichuan 644000China College of Engineering Southwest Petroleum UniversityNanchongSichuan 637001China

Polycrystalline diamond compact(PDC)drill bit often performs with low ROP,short service life and poor stability under complicated and difficult to drill ***,a vertical wheel PDC bit is proposed,which is a new drill bit technology applying an integrated unit combining the tooth wheel and the rotary shaft ***,the experiments on motion and mechanical characteristics of the vertical wheel under the conditions of tooth shape and number of teeth,normal deflection angle of the wheel,and different cutting depth were carried out using variable parameter experimental device,and the movement,force law,and crushing specific work of vertical wheel under different experimental conditions were *** comparative experiments of PDC cutting rock breaking under the conditions of parallel cutting of PDC unit and pre-damage of the wheel were also carried out,and the cutting load of PDC teeth under pre-damage conditions is between 38.72% and 70.95%lower than that of parallel cutting was ***,a comparative experiment of indoor drilling between vertical wheel PDC bit and conventional PDC bit was carried *** show than when drilling in gravel rock,under the same WOB,the torque response of vertical wheel PDC bit is equivalent to that of the PDC bit,while the ROP of vertical wheel PDC bit is 22.94%-53.33% higher than that of conventional PDC bit,and the threedimensional acceleration of the vertical wheel PDC bit is 19.17%-76.23% of that of the PDC *** experimental results contribute to a better understanding of vertical wheels and provide technical support for their use in PDC bits.

关键词： Difficult to drill formation Vertical wheel Vertical wheel PDC bit Rock-breaking mechanism Pre-damage

Hydrogen generation from methanol reforming under unprecedented mild conditions

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Chinese Chemical Letters 2017年第7期28卷 1353-1357页

作者： Yu-Lu Zhan Yang-Bin Shen Shu-Ping Li Bao-Hua Yue xiao-chun zhou Department of Chemistry College of ScienceShanghai UniversityShanghai 200444China Division of Advanced Nanomaterials Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215125China University of Chinese Academy of Sciences Beijing 100049China

A homogeneous catalyst [Cp＊Rh（NH3）（H2O）2]-（3＋） has been found for the clean conversion of methanol and water to hydrogen and carbon dioxide. The simple and easily available reaction steps can circumvent the formation of CO, therefore, making it possible to avoid inactivating catalysts and contaminating the hydrogen fuel. Different from conventional reforming method for hydrogen production, no additional alkaline or organic substances are required in this method. Valuable hydrogen can be obtained under ambient pressure at 70 C, corresponding TOF is 83.2 h 1. This is an unprecedented success in reforming methanol to hydrogen. Effects of reaction conditions, such as reaction temperature, initial methanol concentration and the initial p H value of buffer solution on the hydrogen evolution are all systematically investigated. In a certain range, higher reaction temperature will accelerate reaction rate. The slightly acidic condition is conducive to rapid hydrogen production. These findings are of great significance to the present establishment of the carbon-neutral methanol economy.

关键词： Homogeneous catalysts Methanol reforming Hydrogen Low temperature Low CO

Highly active iridium catalyst for hydrogen production from formic acid

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Chinese Chemical Letters 2017年第8期28卷 1746-1750页

作者： Ying Du Yang-Bin Shen Yu-Lu Zhan Fan-Di Ning Liu-Ming Yan xiao-chun zhou Department of Chemistry Shanghai UniversityShanghai 200444China Division of Advanced Nanomaterials Suzhou Institute of Nano-tech and Nano-bionicsChinese Academy of SciencesSuzhou 215125China University of Chinese Academy of Sciences Beijing 100049China University of Science and Technology of China Hefei 230026China

Formic acid（FA） dehydrogenation has attracted a lot of attentions since it is a convenient method for H_2 production. In this work, we designed a self-supporting fuel cell system, in which H_2 from FA is supplied into the fuel cell, and the exhaust heat from the fuel cell supported the FA dehydrogenation. In order to realize the system, we synthesized a highly active and selective homogeneous catalyst Ir Cp＊Cl_2 bpym for FA dehydrogenation. The turnover frequency（TOF） of the catalyst for FA dehydrogenation is as high as7150 h^（-1）at 50°C, and is up to 144,000 h^（-1）at 90°C. The catalyst also shows excellent catalytic stability for FA dehydrogenation after several cycles of test. The conversion ratio of FA can achieve 93.2%, and no carbon monoxide is detected in the evolved gas. Therefore, the evolved gas could be applied in the proton exchange membrane fuel cell（PEMFC） directly. This is a potential technology for hydrogen storage and generation. The power density of the PEMFC driven by the evolved gas could approximate to that using pure hydrogen.

关键词： Formic acid Hydrogen generation Homogeneous catalyst Catalytic performance Proton exchange membrane fuel cell

Effect of stress-relief annealing on thermal fatigue cracks for die-casting die steels

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Journal of Iron and Steel Research International 2024年第5期31卷 1164-1176页

作者： Zhi-xiong Bai xiao-chun Wu School of Materials Science and Engineering Shanghai UniversityShanghai200444China

The effect of stress-relief annealing at different stages of thermal fatigue tests on crack growth was investigated using a self-built thermal cycle *** results showed that annealing could limit crack expansion *** reduced dislocation density and released the accumulation of residual *** addition,the strain accumulation in carbides was reduced by this *** was also found that double annealing was even more effective at inhibiting crack expansion compared to single stress-relief *** 1000 cycles,the maximum crack length was reduced by 31.1%and 45.2%for the samples after using the optimal single and double annealing processes,*** single stress-relief annealing,earlier annealing provides more benefit in delaying crack ***,effective double stress-relief annealing requires a suitable time interval between the annealing ***,after 800 cycles,surface hardness decreased significantly accompanied by an increase in the size and number of carbides,and cracks expanded predominantly along grain boundaries.

关键词： Thermal fatigue Steel Carbide Stress-relief annealing Dislocation Residual stress

Effect of Molecular Weight on Thermoelectric Performance of P3HT Analogues with 2-Propoxyethyl Side Chains

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 268-281页

作者：董得福 WANG Wei ZHAN chun LI Chenglong zhou Qisheng 肖生强 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

By replacing hexyl chains in poly(3-hexylthiophene)(P3HT)with 2-propoxyethyls,four poly(3-(2-propoxyethyl)thiophene)(P3POET)homopolymers with comparable polydispersity indexes(PDI)and regioregularities were prepared herein in addition with step increment of about 7 kDa on numberaverage molecular weight(M_(n))from around 11 to 32 kDa(accordingly denoted as P11k,P18k,P25k,and P32k).When doped in film by FeCl_(3)at the optimized conditions,the maximum power factor(PF_(max))increases greatly from 4.3μW·m^(-1)·K^(-2)for P11k to 8.8μW·m^(-1)·K^(-2)for P18k,and further to 9.7μW·m^(-1)·K^(-2)for P25k,followed by a slight decrease to 9.2μW·m^(-1)·K^(-2)for *** close Seebeck coefficients(S)at PF_(max)are observed in these doped polymer films due to their consistent frontier orbital energy levels and Fermi *** main contribution to this PF_(max)evolution thus comes from the corresponding conductivities(σ).Theσvariation of the doped films can be rationally correlated with their microstructure evolution.

关键词： conjugated polymer molecular weight microstructure thermoelectric performance

Correction to:Assembly-level analysis on temperature coefficient of reactivity in a graphite-moderated fuel salt reactor fueled with low-enriched uranium

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Nuclear Science and Techniques 2024年第2期35卷 234-235页

作者： xiao-xiao Li De-Yang Cui chun-Yan Zou Jian-Hui Wu Xiang-zhou Cai Jin-Gen Chen Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China CAS Innovative Academy in TMSR Energy System Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

Following publication of the original article,the authors observed that both Fig.5 and Fig.4 depict the same *** 5 was inaccurately referenced and *** correct Fig.5 is copied below:The original article has been updated.

关键词： fuel enriched reactivity

Remote sensing of air pollution incorporating integrated-path differential-absorption and coherent-Doppler lidar

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Defence Technology（防务技术） 2024年第1期31卷 594-601页

作者： Ze-hou Yang Yong Chen chun-li Chen Yong-ke Zhang Ji-hui Dong Tao Peng xiao-feng Li Ding-fu zhou School of Physics Beijing Institute of TechnologyBeijing 100081China Southwest Institute of Technical Physics Chengdu 610041SichuanChina School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China

An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and *** system incorporates integrated-path differential absorption lidar(DIAL) and coherent-doppler lidar(CDL) techniques using a dual tunable TEA CO_(2)laser in the 9—11 μm band and a 1.55 μm fiber *** combining the principles of differential absorption detection and pulsed coherent detection,the system enables agile and remote sensing of atmospheric *** static tests validate the system’s real-time detection capabilities,including the measurement of concentration-path-length product(CL),front distance,and path wind speed of air pollution plumes over long distances exceeding 4 *** experiments is conducted with the *** of the pollutant concentration and the wind field is carried out in an approximately 1 km slant range over scanning angle ranges from 45°to 65°,with a radial resolution of 30 m and10 *** test results demonstrate the system’s ability to spatially map atmospheric pollution plumes and predict their motion and dispersion patterns,thereby ensuring the protection of public safety.

关键词： Differential absorption LIDAR Coherent Doppler lidar Remoting sensing Atmospheric pollution

RARRES2 regulates lipid metabolic reprogramming to mediate the development of brain metastasis in triple negative breast cancer

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Military Medical Research 2024年第1期11卷 34-49页

作者： Yi-Qun Li Fang-zhou Sun chun-xiao Li Hong-Nan Mo Yan-Tong zhou Dan Lv Jing-Tong Zhai Hai-Li Qian Fei Ma Department of Medical Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China State Key Laboratory of Molecular Oncology National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China

Background Triple negative breast cancer(TNBC),the most aggressive subtype of breast cancer,is characterized by a high incidence of brain metastasis(BrM)and a poor *** the most lethal form of breast cancer,BrM remains a major clinical challenge due to its rising incidence and lack of effective treatment *** evidence suggested a potential role of lipid metabolic reprogramming in breast cancer brain metastasis(BCBrM),but the underlying mechanisms are far from being fully *** Through analysis of BCBrM transcriptome data from mice and patients,and immunohistochemical validation on patient tissues,we identified and verified the specific down-regulation of retinoic acid receptor responder 2(RARRES2),a multifunctional adipokine and chemokine,in BrM of *** investigated the effect of aberrant RARRES2 expression of BrM in both in vitro and in vivo *** signaling pathway components were evaluated using multi-omics *** were performed to elucidate the regulation of lipid metabolic reprogramming of *** We found that downregulation of RARRES2 is specifically associated with BCBrM,and that RARRES2 deficiency promoted BCBrM through lipid metabolic ***,reduced expression of RARRES2 in brain metastatic potential TNBC cells resulted in increased levels of glycerophospholipid and decreased levels of triacylglycerols by regulating phosphatase and tensin homologue(PTEN)-mammalian target of rapamycin(mTOR)-sterol regulatory element-binding protein 1(SREBP1)signaling pathway to facilitate the survival of breast cancer cells in the unique brain *** Our work uncovers an essential role of RARRES2 in linking lipid metabolic reprogramming and the development of ***2-dependent metabolic functions may serve as potential biomarkers or therapeutic targets for BCBrM.

关键词： RARRES2 Lipid metabolic reprogramming Brain metastasis(BrM) Breast cancer