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Solvent-free synthesis of zeolite catalysts

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Science China Chemistry 2015年第1期58卷 6-13页

作者： Xiangju meng Qinming Wu Fang Chen feng-Shou Xiao Key Lab of Applied Chemistry of Zhejiang Province Department of Chemistry Zhejiang University

The most used method for preparation of zeolites is hydrothermal synthesis from silicate or aluminosilicate gels at temperatures in the range of 60-200 ℃. Excess water used in the industrial process results in several issues, including high autogeneous pressure, low efficiency, pollution, etc. To solve these problems, several strategies have been developed. This review describes the solvent-free synthesis of zeolites. The combination of solvent-free synthesis and organotemplate-free synthesis can open the pathway to a highly sustainable zeolite synthesis protocol in industry.

关键词： zeolites solvent-free sustainable

Precise determination of the pole position of the exotic Z_(c)(3900)

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 84-90页

作者： y.n-Hua Chen meng-Lin Du feng-Kun Guo School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083China School of Physics University of Electronic Science and Technology of ChinaChengdu 611731China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Peng Huanwu Collaborative Center for Research and Education Beihang UniversityBeijing 100191China

We perform a unified description of the experimental data of the π^(+)π^(-)and J/ψπ^(±)invariant mass spectra for e^(+)e^(-)→J/ψπ^(+)π^(-)and the D^(0)D^(*-)mass spectrum for e^(+)e^(-)→D^(0)D^(*-)π^(+)at e^(+)e^(-)center-of-mass energies 4.23 and 4.26 *** analysis takes into account open-charm meson loops that contain triangle singularities,the J/ψπ-DD^(*)coupled-channel interaction respecting unitarity,and the strong ππ-KK final state interaction using dispersion *** analysis leads to a precise determination of the Z_(c)(3900)pole with the pole mass and width(3880.7±1.7_(stat)±22.4_(syst))MeV and(35.9±1.4_(stat)±15.3_(syst))MeV,respectively,and hints at that the DD^(*)molecular and non-molecular components are of similar importance in the Z_(c)(3900)formation.

关键词： exotic hadrons dispersion relations final state interaction triangle singularity

Application of machine learning in predicting the rate-dependent compressive strength of rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1356-1365页

作者： Mingdong Wei Wenzhao meng feng Dai Wei Wu School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China

Accurate prediction of compressive strength of rocks relies on the rate-dependent behaviors of rocks, and correlation among the geometrical, physical, and mechanical properties of rocks. However, these properties may.not be easy to control in laboratory experiments, particularly in dynamic compression experiments. By training three machine learning models based on the support vector machine(SVM), backpropagation neural network(BPnn), and random forest(RF) algorithms, we isolated different input parameters, such as static compressive strength, P-wave velocity, specimen dimension, grain size, bulk density, and strain rate, to identify their importance in the strength prediction. Our results demonstrated that the RF algorithm shows a better performance than the other two algorithms. The strain rate is a key input parameter influencing the performance of these models, while the others(e.g. static compressive strength and P-wave velocity) are less important as their roles can be compensated by alternative parameters. The results also revealed that the effect of specimen dimension on the rock strength can be overshadowed at high strain rates, while the effect on the dynamic increase factor(i.e. the ratio of dynamic to static compressive strength) becomes significant. The dynamic increase factors for different specimen dimensions bifurcate when the strain rate reaches a relatively high value, a clue to improve our understanding of the transitional behaviors of rocks from low to high strain rates.

关键词： Machine learning Rock dynamics Compressive strength Strain rate

Clinical characteristics and outcomes of patients with hepatic veno-occlusive disease induced by Gynura segetum: A retrospective study

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Journal of Integrative Medicine 2020年第5期18卷 434-440页

作者： meng-xiao feng y.n Shen yuan-qiang Lu Department of Emergengy Medicine the First Afiliated HospitalSchool of MedicineZhejiong UniversityHangzhou 310003Zhejiang ProvinceChina Department of Geriatric Medicine the First Afliated HospitalSchool of MedicineZhejiang UniversityHangzhou 3100030 Zhejiang ProvinceChina Zhejiang Provincial Key Laborotory for Dignosis and Treatment 0f Aging and Physiccemical Injury Diseases the First Aliliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310003.Zhefiang ProvinceChina Department of Hepaobillary and Pancrearic Surgery.the First Afilited Hospial School of Medicine.Zhejiang UniversityHangzhou 310003Zhejiang ProvinceChina

Objective: Hepatic veno-occlusive disease(HVOD) has attracted increasing attention in recent years due to its relationship with ingestion of Gynura segetum. The mortality of severe HVOD remains high due to the lack of specific therapies. The aim of the study was to delineate the clinical characteristics and outcomes and explore the potential prognostic factors of ***: This was a single-center retrospective study. Eighty.nine HVOD patients were screened from the First Affiliated Hospital of Zhejiang University with an ingestion history of G. segetum before developing symptoms from January 2009 to May 2018. The enrolled patients were divided into the survivor and death groups according to the clinical follow-up that ended on September 1, 2019. The demographic variables and clinical data of the patients were recorded. A binary logistic regression analysis and receiver operating characteristic curve were conducted to identify the prognostic factors and assess the prognostic value for predicting death, and a survival analysis was performed to evaluate the clinical ***: Sixty-four patients were eligible for further analysis. Most patients showed abdominal distension and were positive for migrating dullness in the abdomen(P = 0.740 and P = 0.732, respectively). The patients who died had higher levels of model for end-stage liver disease score, and higher prothrombin time than those who survived(both P nts in both the survival and death groups showed ascites with abnormal imaging presentations of the liver parenchyma and hepatic blood ***, we found that hydrothorax was detected in 21(65.63%) patients in the death group and 19(59.38%) patients in the survivor group during hospitalization, which was rarely mentioned in previous studies. Furthermore, international normalized ratio(InR) and creatinine are found to be potential independent prognostic factors for predicting death. Six severe patients achieved clinical

关键词： Hepatic veno-occlusive disease Gynura segetum Clinical characteristics Prognostic Survival analysis

Fully fluorinated hybrid zeolite imidazole/Prussian blue analogs with combined advantages for efficient oxygen evolution reaction

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Chinese Chemical Letters 2024年第6期35卷 222-228页

作者： Jiayu Xu meng Li Baoxia Dong Ligang feng School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Hybrid metal-organic framework(MOF)derivatives play a significant role in the novel catalyst development in energy conversion ***,we demonstrated the low-temperature fully fluorinated zeolitic imidazole framework(ZIF)coupled with a three-dimensional open framework Prussian blue analog(PBA)with combined advantages for electrocatalytic oxygen evolution reaction(OER)in water splitting *** spectroscopic analysis and the electrochemical studies revealed the combined advantages of efficient electronic effect and active site *** of good conductivity improvement by.ndoped carbon derived from ZIF and the high electrochemical surface area and active site exposure from PBA derivatives,good catalytic performance was obtained on the optimal catalyst of Co ni ZIF/Co Fe-PBAF-300,which required a low overpotential of 250 m V to reach 10 m A/cm^(2)loaded on the glassy carbon electrode,with Tafel slope of 47.4 m V/dec,and very high dynamic and steady *** addition,the multi-component with the mixed structure from highly polar metal fluorides promoted the easy formation of the active phase as revealed by the post-sample *** current results showed a novel composite catalyst materials development from the hybrid MOF derivatives,which would be promising in the electrolysis of water oxidation reactions and energy-relevant catalysis reactions.

关键词： Metal-organic framework Zeolitic imidazole framework Prussian blue analog Fluoridation Multi-component Oxygen evolution reaction

Cu,n codoped carbon nanosheets encapsulating ultrasmall Cu nanoparticles for enhancing selective 1,2-propanediol oxidation

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Journal of Energy Chemistry 2024年第4期91卷 27-35页

作者： y.nghai feng Min yu Minjia meng Lei Liu Dewei Rao Institute for Advanced Materials School of Materials Science and EngineeringJiangsu UniversityZhenjiang 212013JiangsuChina School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

In the selective oxidation of biomass-based 1,2-propanediol(PDO)with oxygen as the terminal oxidant,it is challenging to improve the lactic acid(LA)selectivity for nonnoble metal nanoparticles(nPs)due to their limited oxygen reduction rate and easy C-C *** the high economic feasibility of nonnoble metals,i.e.,Cu,in this work,copper and nitrogen codoped porous carbon nanosheets encapsulating ultrafine Cu nanoparticles(Cu@Cu-n-C)were developed to realize highly selective of PDO oxidation to *** carbon-encapsulated ultrasmall Cu^(0)nPs in Cu@Cu-n-C have high PDO dehydrogenation activity while n-coordinated Cu(Cu-n)sites are responsible for the high oxygen reduction ***,the performance of catalytic PDO conversion to LA is optimized by a proposed pathway of PDO→hydroxylacetone→lactaldehyde→***,the enhanced LA selectivity is 88.5%,and the PDO conversion is up to 75.1%in an O_(2)-pressurized reaction system(1.0 MPa O_(2)),superior to other Cu-based catalysts,while in a milder nonpressurized system(O_(2)flow rate of 100 mL min-1),a remarkable LA selectivity(94.2%)is obtained with 39.8%PDO conversion,2.2 times higher than that of supported Au nanoparticles(1%Au/C).Moreover,carbon encapsulation offers Cu@Cu-n-C with strong leaching resistance for better recycling.

关键词： Selective oxidation Copper and nitrogen doped carbon 1,2-Propanediol Ultrasmall Cu nanoparticles Lactic acid

Multistimuli Responsive and Thermoregulated Capability of Coaxial Electrospun Membranes with Core-sheath Structure and Functional Polypyrrole Layer

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Chinese Journal of Polymer Science 2022年第11期40卷 1380-1388页

作者： meng-Hang Gao Wen feng Xiao-Dong Qi y.ng Wang Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science&EngineeringSouthwest Jiaotong UniversityChengdu610031China

Developing thermal management fabrics with good energy storage and multistimuli responsive properties is important for regulating the body temperature in complex ***,the intelligent nonwoven membranes were fabricated via a coaxial electrospinning method,resulting in a core-sheath structure with poly(ethylene glycol)(PEG)as core and polyurethane(PU)as ***,polypyrrole(PPy)with good light absorption ability and electrical conductivity was deposited onto the surface of the PU@PEG electrospun fibers via electrochemical *** PPy layer enabled the membranes to respond quickly to sunlight and electrical *** membranes could heat up to 86°C under simulated sunlight within 200 s or produce remarkable electrothermal effect under a low voltage input of only 1V,exhibiting efficient energy conversion and storage *** photothermal and electrothermal conversion effect could be easily adjusted by controlling the polymerization time of ***,the multifunctional membranes with high latent heat,good mechanical properties as well as excellent photothermal/electrothermal conversion ability are promising in personal thermal management applications.

关键词： Phase change materials Polypyrrole Coaxial electrospinning Photothermal conversion Electrothermal conversion

Assessment of water-based cutting fluids with green additives in broaching

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Friction 2020年第6期8卷 1051-1062页

作者： Jing nI Kai feng Lihua HE Xiaofan LIU Zhen meng School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310018China

In order to improve the cutting performance in broaching,the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green ***,water-based solutions with castor oil,surfactant(linear alkylbenzene sulfonate,LAS),and nanographite were prepared by ultrasonic agitation and sprayed into the zone of broaching via *** performances of the cutting fluids,in terms of the viscosity,specific heat,wetting angle,and droplet size,were evaluated to discuss their effects on the broaching *** the fluids,the addition of LAS into oil-in-water(WO-S),where its cutting fluid with 10 wt.%castor oil and 1.5 wt.%surfactant,exhibited the lowest broaching *** regard to the lubricating and cleaning mechanisms,WO-S has good wettability and permeability,and hence,can lubricate the cutting edge of the tool to decrease the cutting load,cool the cutting edge to keep it sturdy,and clean the surface of the cutting edge to keep it *** results reveal that the simultaneous addition of castor oil and LAS had remarkable effects on the lubrication and cleaning,and resulted in a broaching load reduction of more than 10%compared to commercial cutting ***,the addition of nanographite could not improve the lubrication owing to its agglomeration.

关键词： cutting fluid castor oil linear alkylbenzene sulfonate nanographite broaching

Polyethylenimine-modified graphene quantum dots promote endothelial cell proliferation

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Regenerative Biomaterials 2024年第2期3卷 137-146页

作者： Qirong Xu Chen Li Xiangy.n meng Xinghong Duo yakai feng School of Chemistry and Chemical Engineering Qinghai University for NationalitiesXining 810007PR China Key Laboratory of national Ethnic Affairs Commission of Resource Chemistry and Ecological Environment Protection on Qinghai-Tibet Plateau Xining 810007PR China institute of Disaster and Emergency Medicine Tianjin UniversityTianjin 300072PR China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350PR China Key Laboratory of Systems Bioengineering(Ministry of Education) Tianjin UniversityTianjin 300072PR China

Endothelial cell proliferation plays an important role in angiogenesis and treatment of related *** aim of this study was to evaluate the effect of polyethylenimine(PEI)-modified graphene quantum dots(GQDs)gene vectors on endothelial cell *** GQDs-cationic polymer gene vectors were synthesized by amidation reaction,and used to deliver pznF580 gene to Human umbilical vein endothelial cells(HUVECs)for promoting their *** chemical modification of GQDs can ad-just gene vectors'surface properties and charge distribution,thereby enhancing their interaction with gene molecules,which could effectively compress the pZnF580 *** CCK-8 assay showed that the cell viability was higher than 80%at higher vector concentration(40μg/mL),demonstrating that the GQDs-cationic polymer gene vectors and their gene complex nanoparticles(nPs)having low *** results of the live/dead cell double staining assay were consistent with those of the CCK-8 assay,in which the cell viability of the A-GQDs/pZnF580(94.38±6.39%),C-GQDs-PEI-polylactic acid-co-polyacetic acid(PLGA)/pZnF580(98.65±6.60%)and n-GQDs-PEI-PLGA/pZnF580(90.08±1.60%)groups was significantly higher than that of the Lipofectamine 2000/pznF580(71.98±3.53%)positive treatment *** results of transfection and western blot experiments showed that the vector significantly enhanced the delivery of plasmid to HUVECs and increased the expression of pZnF580 in *** addition,the gene nPs better promote endothelial cell migration and *** cell migration rate and proliferation ability of C-GQDs-PEI-PLGA/pZnF580 and n-GQDs-PEI-PLGA/pZnF580 treatment groupS were higher than those of Lipofectamine 2000/pDnA treatment *** GQDs possess the potential to serve as efficient gene *** tightly bind gene molecules through charge and other non-covalent interactions,significantly improving the effciency of gene delivery and ensuring the smooth release of genes with

关键词： graphene quantum dots polyethylenimine ZnF580 gene endothelial cell proliferation