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Hydrogen storage thermodynamics and kinetics of as-cast Ce-Mg-Ni-based alloy

Journal of Iron and Steel Research(International) 2024年第3期31卷 752-766页

作者： Yan Qi Xin Zhang jun li Dong-liang Zhao Shi-hai guo Yang-huan Zhang Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China China Rare Earth New Material(Weishan)Co..Ltd. Jining 277600ShandongChina Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou 014010Inner MongoliaChina

The reaction kinetics of alloys based on magnesium are known to be greatly improved by the partial substitution of Mg with rare earths and transition metals,particularly *** enhanced superficial hydrogen dissociation rate,the weakened Mg-H bond and the lower activation energy following element replacement are thought to be related to the better *** experimental alloys Ce5Mg_(95-x)Ni_(x)(x=5,10,15)were smelted by the vacuum induction *** phase transformation and structural evolution of experimental alloys before and after reaction with hydrogen were char-acterized by X-ray diffraction,scanning electron microscopy and transmission electron *** cast specimens contain CeMg_(12),Mg and Mg_(2)Ni phases,and the increase in Ni content results in an obvious growth of Mg_(2)Ni *** isothermal and non-isothermal hydrogenation and dehydrogenation kinetics of the experimental specimens were investi-gated using the Sievert apparatus,differential scanning calorimetry and thermal gravimetric *** activation energy may be calculated using the Arrhenius and Kissinger *** experimental alloys have been shown to have good activation properties,with a reversible hydriding and dehydriding capacities of around 5.0 wt.%in the first *** initial dehydrogenation temperature of MgH_(2) decreases from 557.5 to 537.7 K with changing Ni content from 5 to 15 at.%.The dehydrogenation activation energy also reduces from 77.09 to 62.96 kJ/mol,which explains the improved hydrogen storage performance caused by Ni *** can be shown that the impact of Ni on the decomposition enthalpy of MgH_(2) is quite modest,with the absolute enthalpy(ΔHr)only decreasing from 78.48 to 76.15 kJ/mol.

关键词： Mg-based alloy Ni content Hydrogen storage kinetics Thermodynamic property Activation energy

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New insights into the deposition of natural gas hydrate on pipeline surfaces:A molecular dynamics simulation study

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Petroleum Science 2024年第1期21卷 694-704页

作者： jun Zhang Hai-Qiang Fu Mu-Zhi guo Zhao Wang li-Wen li Qi Yin You-guo Yan Wei Wei Wei-Feng Han Jie Zhong School of Materials Science and Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina School of Petroleum Engineering China University of Petroleum(East China)Qingdao 266580ShandongChina Department of Alternative Energy PetroChina Research Institute of Petroleum Exploration&DevelopmentLangfang 065007HebeiChina

Natural gas hydrate(NgH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low *** hydrate adhesion on pipelines is viewed as an efficient way to prevent NgH *** studies suggested the water film can greatly increase hydrate adhesion in gas-dominant ***,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion ***,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film *** water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate *** absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fegion of liquid layer,the process of which becomes harder as liquid layer *** a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant ***,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces.

关键词： Deposition Natural gas hydrate Pipelines Water affinity Adhesion strength

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Prospect of ultrahigh-resolution fast neutron absorption spectroscopy based on a laser plasma electron accelerator

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High Power Laser Science and Engineering 2024年第1期12卷 108-115页

作者： Wen-Zhao Wang Jie Feng Xiao-Peng Zhang Yao-jun li Wei-jun Zhou Wen-Chao Yan guo-Qiang Zhang Chang-Bo Fu li-Ming Chen Key Laboratory of Laser Plasma(MoE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina IFSA Collaborative Innovation Center Shanghai Jiao Tong UniversityShanghaiChina Institute of High Energy Physics Chinese Academy of SciencesBeijingChina Shanghai Advanced Research Institute Chinese Academy of SciencesShanghaiChina Key Laboratory of Nuclear Physics and Ion-beam Application(MoE) Institute of Modern PhysicsFudan UniversityShanghaiChina

Fast neutron absorption spectroscopy is widely used in the study of nuclear structure and element analysis. However,due to the traditional neutron source pulse duration being of the order of nanoseconds, it is difficult to obtain a high-resolution absorption spectrum. Thus, we present a method of ultrahigh energy-resolution absorption spectroscopy via a high repetition rate, picosecond duration pulsed neutron source driven by a terawatt laser. The technology of single neutron count is used, which results in easily distinguishing the width of approximately 20 keV at 2 MeV and an asymmetric shape of the neutron absorption peak. The absorption spectroscopy based on a laser neutron source has one order of magnitude higher energy-resolution power than the state-of-the-art traditional neutron sources, which could be of benefit for precisely measuring nuclear structure data.

关键词： fast neutron absorption spectroscopy laser plasma accelerator photo-nuclear neutrons single neutron count

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In situ modification of heavy oil catalyzed by nanosized metal-organic framework at mild temperature and its mechanism

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Chinese Journal of Chemical Engineering 2024年第3期67卷 166-173页

作者： li Wang Ji-Xiang guo Rui-Ying Xiong Chen-Hao gao Xiao-jun Zhang Dan Luo The Unconventional Oil and gas Institute China University of Petroleum-BeijingBeijing 102200China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China

Two catalysts, nano-sized cobalt-metal-organic framework(Co-MOF) and nickel(Ni)-MOF, were successfully prepared by the modification method. Tetralin(C10H12) was used as the hydrogen donor for the catalytic cracking and hydrogenation modification study of the dehydrated crude oil from the Shengli Oilfield. The optimal reaction conditions were determined through orthogonal experiments, and the components of the crude oil and modified oil samples were analyzed. The results revealed that the nanoMOF catalysts were successfully prepared and exhibited high catalytic activity. They could catalyze the cracking of large molecules in heavy oil at mild temperatures(g to the decomposition of the hydrogen donor. When the mass fraction of the catalyst was 0.2%, the mass fraction of the hydrogen donor was 1%, and the reaction temperature was 280°C, the Ni-MOF showed the best catalytic viscosity reduction effect. It could reduce the viscosity of heavy oil at 50°C from 15761.9 m Pa.s to 1266.2 m Pa.s,with a viscosity reduction rate of 91.97%. The modification effect of Co-MOF was the next best, which could reduce the viscosity of heavy oil to 2500.1 m Pa.s with a viscosity reduction rate of 84.14%. Molecular dynamics simulations revealed a strong interaction force between the MOF surface and asphaltene molecules. In the process of heavy-oil catalytic hydrogenation, the nano-MOF catalyst exhibited high catalytic activity. On the one hand, the empty d orbitals outside the metal atoms in the catalyst could polarize the carbon atoms in the organic matter, accelerating the breaking of long chains. On the other hand, the metal atoms in the catalyst could bond with the carbon σ bonds, breaking the carbon-carbon bonds. This disrupted the structure of the recombined components in the crude oil, irreversibly reducing the viscosity of the heavy oil and improving its fluidity.

关键词： Nano-sized MOF Petroleum Viscosity reduction Catalyst Nanomaterials

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Labial inverse dilaceration of bilateral maxillary central incisors: A case report

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World Journal of Clinical Cases 2024年第1期12卷 180-187页

作者： jun-Min Wang li-Feng guo li-Qiong Ma Jing Zhang Stomatological Hospital and College Key Laboratory of Oral Diseases Research of Anhui ProvinceAnhui Medical UniversityHefei 230032Anhui ProvinceChina Stomatological Hospital and College Anhui Medical UniversityHefei 230032Anhui ProvinceChina

BACKgROUND Dilaceration is a rare dental developmental anomaly characterized by an abrupt deviation along the longitudinal axis of the root in which an angulation forms between the root and the ***,we report on dilacerated bilateral maxi-llary central incisors in mixed *** SUMMARY A 10-year-old girl presented with a chief complaint of unerupted central *** oral examination and radiography provided the basis for a diagnosis of dilaceration of the maxillary central *** surgical exposure of the impacted teeth,a button with an attached chain was applied to the palatal surface of teeth 11 and *** 8 mo,a button was bonded to the labial surface of the crown to fix an elastic chain and move the teeth toward the maxillary ***,a fixed appliance was applied to tooth alignment to Class 1 malocclusion using a 0.019×0.025-inch nickel-titanium *** 3 years of follow-up,the clinical findings and radiographic assessment showed that the roots had developed with vital dental pulp and healthy periodontium,were acceptable aesthetically,and showed no *** The rare occurrences of dilacerated bilateral maxillary central incisors can be successfully treated through surgical exposure and orthodontics.

关键词： Dilaceration Traumatic injury Central incisors Child Primary tooth Case report

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Outcomes of endoscopic sclerotherapy for jejunal varices at the site of choledochojejunostomy (with video): Three case reports

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World Journal of gastroenterology 2024年第14期30卷 2059-2067页

作者： jun liu Peng Wang li-Mei Wang Jing guo Ning Zhong Department of gastroenterology Qilu Hospital of Shandong UniversityJinan 250012Shandong ProvinceChina

BACKgROUND Hemorrhage associated with varices at the site of choledochojejunostomy is an unusual,difficult to treat,and often fatal manifestation of portal *** far,no treatment guidelines have been *** SUMMARY We reported three patients with jejunal varices at the site of choledochojejun-ostomy managed by endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoacrylate injection at our institution between june 2021 and August *** reviewed all patient records,clinical presentation,endoscopic findings and treatment,outcomes and *** patients who underwent pancre-aticoduodenectomy with a Whipple anastomosis were examined using conven-tional upper gastrointestinal endoscopy for suspected hemorrhage from the afferent jejunal *** with stigmata of recent hemorrhage or active he-morrhage were observed around the choledochojejunostomy site in all three *** injection of lauromacrogol/α-butyl cyanoacrylate was carried out at jejunal varices for all three *** bleeding ceased and patency was observed for 26 and 2 months in two *** one patient with multiorgan failure and internal environment disturbance,rebleeding occurred 1 month after endoscopic sclerotherapy,and despite a second endoscopic sclero-therapy,repeated episodes of bleeding and multiorgan failure resulted in eventual *** We conclude that endoscopic sclerotherapy with lauromacrogol/α-butyl cyanoac-rylate injection can be an easy,effective,safe and low-cost treatment option for jejunal varicose bleeding at the site of choledochojejunostomy.

关键词： Endoscopic sclerotherapy Jejunal varices Choledochojejunostomy Portal vein hypertension Case report

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In situ anchoring in carbon matrix of Bi_(2)O_(2)CO_(3) as a high-performance anode material for li-ion batteries

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Rare Metals 2024年第8期43卷 3634-3646页

作者： Pu-Qiang He jun guo Hui Huang Zhong-Cheng guo Faculty of Metallurgy and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Research Center of Metallurgical Electrode Materials Engineering Technology Kunming 650106China Kunming Hendera Science and Technology Co. Ltd.Kunming 650106China

Bismuth-based anode materials have been regarded as promising li-ion batteries due to their high theoretical ***,their low conductivity and associated volume expansion inhabited their *** this work,Bi_(2)O_(2)CO_(3)@C composites were successfully synthesized by in situ anchoring of flower-like Bi_(2)O_(2)CO_(3) nanosheets on a carbon-based substrate via *** unique composited structure of Bi_2O_(2)-CO_(3)@C leads to a stable specific capacity of 547 mAh·g^(-1)after 100 cycles at a current density of 0.1 A·g^(-1).Notably,it demonstrates excellent rate capability with a specific capacity of 210 mAh·g^(-1)at 5 A·g^(-1).After 550 cycles at a current density of 0.5 A·g^(-1),a high reversible capacity of nearly 400 mAh·g^(-1)was ***,in situ X-ray diffraction measurements clearly demonstrate the conversion between Bi and li_(3)Bi during alloying/dealloying,confirming the good electrochemical reversibility of the materials for li *** reaction kinetics of Bi_(2)O_(2)CO_(3)@C were further investigated using galvanostatic intermittent titration ***,Bi_2O_(2)-CO_(3)@C exhibited excellent long-term stability,maintaining its high reversible capacity for over 200 cycles at a current density of 0.5 A·g^(-1)in a full cell configuration using li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) as the cathode *** result further underscores its promising potential for lithium-ion *** work may provide inspiration for the design of alloy-type negative electrode materials for high-performance rechargeable batteries.

关键词： Bi_(2)O_(2)CO_(3) Composite materials Anode materials Full batteries

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Strain‑Induced Surface Interface Dual Polarization Constructs PML‑Cu/Bi_(12)O_(17)Br_(2) High‑Density Active Sites for CO_(2) Photoreduction

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Nano-Micro Letters 2024年第5期16卷 169-183页

作者： Yi Zhang Fangyu guo jun Di Keke Wang Molly Meng‑jung li Jiayu Dai Yuanbin She Jiexiang Xia Huaming li School of Chemistry and Chemical Engineering Institute for Energy ResearchSchool of the Environment and Safety EngineeringJiangsu UniversityZhenjiang 212013People’s Republic of China State Key Laboratory Breeding Base of green Chemistry‑Synthesis Technology College of Chemical EngineeringZhejiang University of TechnologyHangzhou 310014People’s Republic of China College of Science and Hunan Key Laboratory of Extreme Matter and ApplicationsNational University of Defense TechnologyChangsha 410073People’s Republic of China Department of Applied Physics The Hong Kong Polytechnic UniversityHung HomHong KongPeople’s Republic of China School of Chemistry and Chemical Engineering National Special Superfine Powder Engineering Research CenterNanjing University of Science and TechnologyNanjing 210094People’s Republic of China Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Zhejiang Normal UniversityJinhua 321004People’s Republic of China

The insufficient active sites and slow interfacial charge trans-fer of photocatalysts restrict the efficiency of CO_(2) *** synchronized modulation of the above key issues is demanding and ***,strain-induced strategy is developed to construct the Bi–O-bonded interface in Cu porphyrin-based monoatomic layer(PML-Cu)and Bi_(12)O_(17)Br_(2)(BOB),which triggers the surface interface dual polarization of PML-Cu/BOB(PBOB).In this multi-step polarization,the built-in electric field formed between the interfaces induces the electron transfer from con-duction band(CB)of BOB to CB of PML-Cu and suppresses its reverse ***,the surface polarization of PML-Cu further promotes the electron converge in Cu *** introduction of PML-Cu endows a high density of dispersed Cu active sites on the surface of PBOB,significantly promoting the adsorption and activation of CO_(2) and CO *** conversion rate of CO_(2) photoreduction to CO for PBOB can reach 584.3μmol g-1,which is 7.83 times higher than BOB and 20.01 times than *** work offers valuable insights into multi-step polarization regulation and active site design for catalysts.

关键词： Bi_(12)O_(17)Br_(2) Porphyrin CO_(2)photoreduction Polarization Active sites

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Multiple exciton generation effect in photocatalytic overall water splitting

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Science China Chemistry 2024年第2期67卷 424-425页

作者： Xiaolei guo Ji-jun Zou Key Laboratory for green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

This highlight is based on recent research published in Nature Energy by li and co-workers [1] from Northwestern Polytechnology University, reporting an exceeding 100% internal quantum efficiency(IQE) in photocatalytic overall water splitting. This breakthrough promises a bright future for efficient photocatalyst design by utilizing the multiple exciton effect(MEg).

关键词： splitting effect utilizing

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Micro-nanoarchitectonic of aluminum-hydrogel propellant with static stability and dynamic rheology

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 87-96页

作者： Huiyan guo Huaiyu li Hongzhi Zhang Lun Pan Chengxiang Shi Kang Xue Xiangwen Zhang Ji-jun Zou Key Laboratory for Advanced Fuel and Propellant of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

The aluminum-water system is a promising propellant due to high energy and low signal characteristics,and the gel form is easier to store and *** this work,hydrogels of water and aluminum particles were prepared using the low-molecular-weight gellant *** various physical properties of gel systems,including the water loss rate,phase transition temperature,and centrifugal stability at different gellant and aluminum contents,were *** properties were assessed through shear thinning tests,thixotropy tests,strain sweep analysis,and frequency sweep *** microstructure of the gel was obtained through scanning electron microscopy *** results show that the aluminum-hydrogel network structure is composed of micron-scale aluminum and agarose nanosheets,and the unique micro-nanostructure endows the gel with excellent mechanical strength and thermal stability,which improve with increasing gellant and aluminum ***,the gel with 2% agarose and 20% aluminum had the best performance;the storage modulus reached 90647 Pa,which was within the linear viscoelastic region,and the maximum withstand pressure was 111.2 kPa,which was 118.8% greater than that of the pure ***,the gel demonstrates remarkable shear thinning behavior and can undergo gel-sol transformation upon shearing or heating to exceeding 114℃.

关键词： aluminum-water propellant gelled propellant rheological property mechanical strength

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