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Numerical study of inhibition mechanism of high-pressure hydrogen leakage self-ignition with the addition of ammonia

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Petroleum Science 2023年第5期20卷 3184-3193页

作者： lin Teng Xi-Gui li Zhi-Wei Shan Wei-Dong li Xin Huang Peng-Bo Yin Yong-Zhen liu jiang Bian Yu Luo li-long jiang National Engineering Research Center of Chemical Fertilizer Catalyst(NERC-CFC) College of Chemical EngineeringFuzhou UniversityFuzhou350000FujianChina Qingyuan Innovation Laboratory(QYIL Fujian Innovation Laboratory of Chemical Engineering)Quanzhou362000FujianChina cEngineering China University of Petroleum(East China)Qingdao266580ShandongChina State Key Laboratory of Automobile Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing100084China

Hydrogen and ammonia have attracted increasing attention as carbon-free *** is considered to be an effective energy storage and hydrogen storage ***,a small amount of unremoved NH3 is still present in the product during the decomposition of ammonia to produce ***,it is very essential to investigate the self-ignition of hydrogen-ammonia mixtures in order to accommodate the various scenarios of hydrogen energy *** this paper,the effect of NH3 addition on the self-ignition of high-pressure hydrogen release is numerically *** RNG k-εturbulence model,EDC combustion model,and 213-step detailed NH_(3)/H_(2) combustion mechanism are ***-Pro programs for zero-dimensional homogeneous and constant volume adiabatic reactor models are used for sensitivity analysis and ignition delay time of the chemical reaction *** results showed that the minimum burst pressure required for self-ignition increased significantly after the addition of *** maximum temperature and shock wave intensity inside the tube decreases with increasing ammonia *** ignition delay time and H,HO2,and OH radicals reduce with increasing ammonia concentration.H and HO2 radicals are suggested as indicators for tracking the second and third flame branches,respectively.

关键词： Ammonia-hydrogen energy Self-ignition Shock waves Diffusion ignition Computational fluid dynamics

顶空-气相色谱质谱法快速测定土壤和固废中二甲基亚砜的含量

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化学工程师 2024年第3期38卷 23-25,22页

作者：魏厚道李恩帅陈攀新李江龙舒耀皋上海化工院检测有限公司上海200062

本文针对固体样品,通过无水Na_(2)SO_(4)消除水分对二甲亚砜的干扰,利用顶空-气相色谱质谱联用技术建立了一种土壤和固废中二甲基亚砜的测定方法。结果表明,该方法二甲基亚砜峰形良好,检测灵敏度高,线性相关系数R^(2)大于0.999,检出限为... 详细信息

本文针对固体样品,通过无水Na_(2)SO_(4)消除水分对二甲亚砜的干扰,利用顶空-气相色谱质谱联用技术建立了一种土壤和固废中二甲基亚砜的测定方法。结果表明,该方法二甲基亚砜峰形良好,检测灵敏度高,线性相关系数R^(2)大于0.999,检出限为0.02mg·kg^(-1),不同固体样品不同浓度平均加标回收率为96.0%~112%,其相对标准偏差为0.8%~14.9%。该方法前处理简便,自动化程度高,快速灵敏,满足土壤和固废等固体样品对二甲基亚砜的检测要求。

关键词：土壤固废二甲基亚砜顶空气相色谱质谱法

Highly Improved Creep Resistance in Polypropylene Through Thermally Reduced Graphene Oxide and Its Creep lifetime Prediction

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Chinese Journal of Polymer Science 2024年第2期42卷 256-266,I0010页

作者： Can-Can Zhang Jun-long Yang Ya-jiang Huang Guang-Xian li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Polypropylene(PP) exhibits suboptimal creep resistance due to the presence of methyl groups on its main chain, leading to irregular chain segment distribution, diminished inter-chain interaction, and crystallinity. This structural feature causes chain slippage in PP under stress,significantly constraining its service lifetime. In this study, thermally reduced graphene oxide(TrGO) nanosheets were incorporated into the PP matrix, yielding a nanocomposite with exceptional creep resistance performance. Results demonstrated that at a stress of 25 MPa, a 2.0 wt% TrGO content could enhance the creep failure lifetime of PP by 21.5 times compared to neat PP. Rheology, transmission electron microscopy(TEM),and scanning electron microscopy(SEM) characterization techniques were employed to analyze the mechanism of TrGO's influence on PP's creep behavior. It was observed that when TrGO content exceeded 1.0 wt%, an effective particle network structure formed within the PP matrix. This homogeneously dispersed TrGO-formed particle network structure restricted the migration and rearrangement of PP molecular chains, enabling prolonged stress resistance without structural failure. By combining the time-strain superposition method with the critical failure strain as a criterion, generalized creep compliance curves for PP and its composites were established, facilitating the prediction of material creep failure lifetimes, with a strong agreement between experimental and predicted lifetime values. This research proposes a novel strategy aimed at developing polypropylene materials and products with enhanced long-term stability and durability, thus extending service life, reducing failure risk, and broadening their potential across various application domains.

关键词： Thermally reduced graphene oxide Polypropylene Creep failure and lifetime prediction

Promoted hydrogenation of CO2 to methanol over single-atom Cu sites with Na+-decorated microenvironment

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National Science Review 2024年第6期11卷 264-272页

作者： li-li ling Xinyu Guan Xiaoshuo liu Xiao-Mei Lei Zhongyuan lin Hai-long jiang Hefei National Research Center for Physical Sciences at the Microscale Department of Chemistry University of Science and Technology of China School of Energy and Power Engineering North China Electric Power University School of Energy and Environment Southeast University

Although single-atom Cu sites exhibit high efficiency in CO2hydrogenation to methanol,they are prone to forming Cu nanoparticles due to reduction and aggregation under reaction conditions,especially at high ***,single-atom Cu sites stabilized by adjacent Na+ions have been successfully constructed within a metal-organic framework（MOF）-based catalyst,namely *** is found that the electrostatic interaction between the Na+and Hδ-species plays a pivotal role in upholding the atomic dispersion of Cu in MOF-808-NaCu during CO2hydrogenation,even at temperatures of up to 275℃.This exceptional stabilization effect endows the catalyst with excellent activity(306 g·kgcat-1·h-1),high selectivity to methanol（93%） and long-term stability at elevated reaction temperatures,far surpassing the counterpart in the absence of Na+（denoted as MOF-808-Cu）.This work develops an effective strategy for the fabrication of stable single-atom sites for advanced catalysis by creating an alkali-decorated microenvironment in close proximity.

关键词： single-atom sites metal–organic framework CO2 hydrogenation heterogeneous catalysis alkali-metal decoration

The Effect of Blending Ratio on the Structure and Properties of the PPR/PS In situ Fiber Reinforced System Prepared by Multi-Flow Vibration Injection Molding

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Chinese Journal of Polymer Science 2024年第6期42卷 851-863页

作者： Yan-jiang li Meng-long Hu Jun-Wen Zhang Qiang Fu Jie Zhang College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

To enhance the mechanical properties of polypropylene random copolymer(PPR),polystyrene(PS)with four different contents were added to the PPR matrix through melt ***,using the Multi-Flow Vibration Injection Molding(MFVIM)technology,PPR/PS in situ microfiber composites(MFC)with different blending ratios were *** results indicated that blending ratio had a great impact on the phase morphology and crystal structure of MFVIM samples,which was different from those of conventional injection molding(CIM)*** ultrafine fibers could be formed under the shear field and could absorb the PPR molecular chains to form hybrid shish-kebab ***,the PPR matrix could also form shish-kebab structures under the effect of strong *** the PS content reached 20%,under the combined action of PS in situ microfibers and highly oriented crystal structure,the tensile strength and Young’s modulus of the sample were obviously improved and the impact strength remained at a relatively high *** a strong and tough balanced PPR based material was *** results provide valuable insights for expanding the industrial and daily-life applications of PPR and show promising development prospects.

关键词： PPR MFVIM In situ microfibers Shearfield Hybrid shish-kebab structures

Experimental Study on Wire Melting Control Ability of Twin-Body Plasma Arc

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 184-194页

作者： Ruiying Zhang Fan jiang long Xue School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China Beijing Academy of Safety Engineering and Technology Beijing 102617China College of Mechanical and Energy Engineering Beijing University of TechnologyBeijing 100124China

The twin-body plasma arc has the decoupling control ability of heat transfer and mass transfer,which is beneficial to shape and property control in wire arc additive *** this paper,with the wire feeding speed as a characteristic quantity,the wire melting control ability of twin-body plasma arc was studied by adjusting the current separation ratio(under the condition of a constant total current),the wire current/main current and the position of the wire in the arc axial *** results showed that under the premise that the total current remains unchanged(100 A),as the current separation ratio increased,the middle and minimum melting amounts increased approximately synchronously under the effect of anode effect power,the first melting mass range remained constant;the maximum melting amount increased twice as fast as the middle melting amount under the effect of the wire feeding speed,and the second melting mass range was *** the wire current increased,the anode effect power and the plasma arc power were both factors causing the increase in the wire melting amount;however,when the main current increased,the plasma arc power was the only factor causing the increase in the wire melting *** average wire melting increment caused by the anode effect power was approximately 2.7 times that caused by the plasma arc *** minimum melting amount was not affected by the wire-torch distance under any current separation ratio *** the current separation ratio increased and reached a threshold,the middle melting amount remained constant with increasing wire-torch *** the current separation ratio continued to increase and reached the next threshold,the maximum melting amount remained constant with the increasing wire-torch *** effect of the wire-torch distance on the wire melting amount reduced with the increase in the current separation *** this study,the decoupling mechanism and ability of this innovative

关键词： Twin-body plasma arc Melting control ability Melting amount Current separation ratio

One stone three birds:Ni-catalyzed asymmetric allenylic substitution of allenic ethers,hydroalkylation of 1,3-enynes and double alkylation of enynyl ethers

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Chinese Chemical Letters 2024年第8期35卷 282-287页

作者： Zhirong Yang Shan Wang Ming jiang Gengchen li long li Fangzhi Peng Zhihui Shao Key Laboratory of Medicinal Chemistry for Natural Resource Ministry of EducationSchool of Chemical Science and TechnologyYunnan Provincial Center for Research&Development of Natural Productsand State Key Laboratory for Conservation and Utilization of Bio-Resources in YunnanYunnan UniversityKunming 650091China

The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric *** we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions:allenylic substitution of racemic allenic ethers,1,4-hydroalkylation of prochiral 1,3-enynes and double alkylation of newly designed enynyl ether *** methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3,5-dione unit,which is widely present in drugs and biologically active molecules with versatile pharmacological activities.

关键词： Nickel Asymmetric catalysis Allenylic substitution Hydroalkylation Double alkylation Allene 1,3-Enyne Pyrazolidine-3,5-dione

How Well does BCC_CSM1.1 Reproduce the 20th Century Climate Change over China?

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Atmospheric and Oceanic Science Letters 2013年第1期6卷 21-26页

作者： XIN Xiao-Ge WU Tong-Wen li jiang-long WANG Zai-Zhi li Wei-Ping WU Fang-Hua Beijing Climate Center China Meteorological Administration

The historical simulation of phase five of the Coupled Model Intercomparison Project （CMIP5） ex- periments performed by the Beijing Climate Center cli- mate system model （BCC_CSM1.1） is evaluated regard- ing the time evolutions of the global and China mean sur- face air temperature （SAT） and surface climate change over China in recent decades. BCC CSM1.1 has better capability at reproducing the time evolutions of the global and China mean SAT than BCC_CSM1.0. By the year 2005, the BCC_CSM1.1 model simulates a warming am- plitude of approximately I℃ in China over the 1961- 1990 mean, which is consistent with observation. The distributions of the warming trend over China in the four seasons during 1958-2004 are basically reproduced by BCC CSM1.1, with the warmest occurring in winter. Al- though the cooling signal of Southwest China in spring is partly reproduced by BCC_CSM1.1, the cooling trend over central eastern China in summer is omitted by the model. For the precipitation change, BCC_CSM1.1 has good performance in spring, with drought in Southeast China. After removing the linear trend, the interannual correlation map between the model and the observation shows that the model has better capability at reproducing the summer SAT over China and spring precipitation over Southeast China.

关键词： BCC_CSM climate system model simula- tion climate change

Boost the Utilization of Dense FeN_(4) Sites for High-Performance Proton Exchange Membrane Fuel Cells

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Energy & Environmental Materials 2024年第3期7卷 398-405页

作者： Yanrong li Shuhu Yin long Chen Xiaoyang Cheng Chongtai Wang Yanxia jiang Shigang Sun State Key Laboratory of Physical Chemistry of Solid Surfaces Engineering Research Center of Electrochemical Technologies of Ministry of EducationCollege of Chemistry and Chemical Engineering and Discipline of Intelligent Instrument and EquipmentXiamen UniversityXiamen 361005China College of Chemistry and Chemical Engineering Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan ProvinceHainan Normal UniversityHaikou 571158China

Iron-nitrogen-carbon(Fe-N-C)catalysts for the oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs)have seriously been hindered by their poor ORR performance of Fe-N-C due to the low active site density(SD)and site ***,we reported a melamine-assisted vapor deposition approach to overcome these *** melamine not only compensates for the loss of nitrogen caused by high-temperature pyrolysis but also effectively etches the carbon substrate,increasing the external surface area and mesoporous porosity of the carbon *** can provide more useful area for subsequent vapor deposition on active *** prepared 0.20Mela-FeNC catalyst shows a fourfold higher SD value and site utilization than the FeNC without the treatment of *** a result,0.20Mela-FeNC catalyst exhibits a high ORR activity with a half-wave potential(E_(1/2))of 0.861 V and 12-fold higher ORR mass activity than the FeNC in acidic *** the cathode in a H_(2)-O_(2)PEMFCs,0.20Mela-FeNC catalyst demonstrates a high peak power density of 1.30 W cm^(-2),outstripping most of the reported Fe-N-C *** developed melamine-assisted vapor deposition approach for boosting the SD and utilization of Fe-N-C catalysts offers a new insight into high-performance ORR electrocatalysts.

关键词： fuel cells melamine oxygen reduction reaction site density utilization