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Post-treatment of Ti-MWW zeolite with potassium fluoride for propylene epoxidation

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FRONTIERS OF CHEMICAL SCIENCE AND ENGINEERING 2024年第8期18卷 88-0页

作者： Li, Xintong Gong, Xianchen Wang, Jilong Jin, Shengbo Xu, hao wu, Peng East China Normal Univ Sch Chem & Mol Engn State Key Lab Petr Mol & Proc Engn Shanghai Key Lab Green Chem & Chem Proc Shanghai 200062 Peoples R China

Epoxidation of propylene to propylene oxide (PO) with hydrogen peroxide (HPPO) is an environmentally friendly and cost-efficient process in which titanosilicates are used as catalysts. Ti-MWW is a potential industrial catalyst for this process, which involves the addition of HPPO to PO. The silanol groups generated during secondary crystallization unavoidably result in ring-opening of PO and inefficient decomposition of HPPO, which diminish the PO selectivity and the lifespan of Ti-MWW. To address this issue, we conducted post-treatment modifications of the structured Bf-Ti-MWW catalyst with potassium fluoride aqueous solutions. By quenching the silanol groups with potassium fluoride and implanting electron-withdrawing fluoride groups into the Ti-MWW framework, both the catalytic activity and HPPO utilization efficiency were increased. Moreover, the ring opening reaction of PO was prohibited. In a continuous fixed-bed liquid-phase propylene epoxidation reaction, the KF-treated structured Ti-MWW catalyst displayed an exceptionally long lifespan of 2700 h, with a PO yield of 590 gkg-1h-1.

关键词： titanosilicates Ti-MWW propylene epoxidation structured catalyst KF modification ENHANCED CATALYTIC-ACTIVITY EFFICIENT EPOXIDATION ALKENE EPOXIDATION HYDROGEN-PEROXIDE WATER-ADSORPTION TITANOSILICATE TITANIUM PERFORMANCE ETHYLENE MECHANISM

Non-monotonic behavior of jam probability and stretched exponential distribution in pedestrian counterflow

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CHINESE PHYSICS B 2024年第9期33卷 259-266页

作者： Chen, ze-hao wu, zhi-Xi Guan, Jian-Yue Guangxi Normal Univ Guilin 541004 Peoples R China Lanzhou Univ Lanzhou Ctr Theoret Phys Key Lab Theoret Phys Gansu Prov Lanzhou 730000 Peoples R China Lanzhou Univ Key Lab Quantum Theory & Applicat Minist Educ Lanzhou 730000 Peoples R China

We adopt a floor field cellular automata model to study the statistical properties of bidirectional pedestrian flow moving in a straight corridor. We introduce a game-theoretic framework to deal with the conflict of multiple pedestrians trying to move to the same target location. By means of computer simulations, we show that the complementary cumulative distribution of the time interval between two consecutive pedestrians leaving the corridor can be fitted by a stretched exponential distribution, and surprisingly, the statistical properties of the two types of pedestrian flows are affected differently by the flow ratio, i.e., the ratio of the pedestrians walking toward different directions. We also find that the jam probability exhibits a non-monotonic behavior with the flow ratio, where the worst performance arises at an intermediate flow ratio of around 0.2. Our simulation results are consistent with some empirical observations, which suggest that the peculiar characteristics of the pedestrians may attributed to the anticipation mechanism of collision avoidance.

关键词： traffic and crowd dynamics evolutionary game theory 02.50.Le 45.70.Vn FLOW CHARACTERISTICS DYNAMICS

Characteristics,origins,and significance of pyrites in deep-water shales

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Science China Earth Sciences 2024年第2期67卷 313-342页

作者： Chao LIANG Shichao JI Yingchang CAO Keyu LIU Jing wu Fang hao National Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao266580China School of Geosciences China University of PetroleumQingdao266000China Laboratory for Marine Mineral Resource Qingdao National Laboratory for Marine Science and TechnologyQingdao266071China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao266590China

As important metal sulfides in the geochemical cycle of sulfur,the characteristics and formation processes of pyrites can provide useful clues regarding their *** on previous findings,shale pyrites were divided into three major classes(euhedral pyrites,framboidal pyrites(framboids)and metasomatic pyrites)and six sub-classes in this *** the microscopic scale,each type of pyrite is associated with a different formation *** are formed by burst nucleation in environments with a homogeneous distribution of nutrients while euhedral pyrites are usually formed on pre-existing sites(such as=FeS on the minerals surface)in the heterogeneous *** pyrites formed by the replacement of other ions in accountable material by iron ions and hydrogen sulfide ions in hydrothermal *** morphology and isotope value of pyrite provide information to track the origins of their nutrient and characteristics of sulfur and iron *** addition,the trace element content of pyrite can serve as a proxy for paleo-ocean trace element abundance,indicating changes in atmospheric oxygen ***,pyrite can also serves as an indicator of shale gas reservoirs.

关键词： Shale Pyrite Sulfate reduction reaction Isotope fractionation Pyrite element

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Probing the Bardeen-Kiselev black hole with the cosmological constant caused by Einstein equations coupled with nonlinear electrodynamics using quasinormal modes and greybody bounds

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Communications in Theoretical Physics 2024年第6期76卷 102-119页

作者： S R wu B Q Wang z W Long College of Physics Guizhou UniversityGuiyang 550025China College Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China

In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field *** compute the quasinormal frequencies for the Bardeen-Kiselev BH with the cosmological constant due to electromagnetic and gravitational *** varying the BH parameters,we discuss the behavior of both real and imaginary parts of the BH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de Sitter BH surrounded by quintessence(RN-dSQ).Interestingly,it is shown that the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ are different only when the charge parameter q is ***,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime *** interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev BH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates *** also study the reflection and transmission coefficients along with the absorption cross section in the Bardeen-Kiselev BH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.

关键词： quasinormal modes greybody factors Bardeen-Kiselev black hole with cosmological constant

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The nature of electron density enhancement over a wide altitude range during ionosphere heating experiments at EISCAT

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Earth and Planetary Physics 2024年第2期8卷 408-414页

作者： Jun wu Jian wu Jie Feng QingLiang Li ShuJi hao zhengWen Xu HaiSheng zhao YaBin zhang National Key Laboratory of Electromagnetic Environment China Research Institute of Radio Wave PropagationBeijing 102206China School of Physics Xidian UniversityXi’an 710071China

During the course of ionospheric heating experiments, researchers at the European Incoherent Scatter Scientific Association (EISCAT) observed an apparent electron density enhancement. The enhancement extended over a wide range of altitudes, above the reflection altitude of the high-frequency pump wave. However, whether this enhancement actually corresponds to a true enhancement in electron density remains an open question. When the dispersion relation of ion acoustic waves is followed, the frequency ratio of the enhanced ion line to the background ion line suggests that the profile of the effective ion mass may have remained unchanged. Furthermore, the solar radio flux and ion drift velocity indicate no significant changes in the ion species and their densities. In conclusion, the electron density enhancement observed at EISCAT should not, in fact, be considered a true enhancement.

关键词： incoherent scatter radar(ISR) ionospheric heating electron density ion acoustic wave

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Selective photocatalytic oxidation of methane to C1 oxygenates by regulating sizes and facets over Au/znO

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Nano Research 2024年第5期17卷 3810-3818页

作者： Qiang zhou Xinyu Wang Xiaojie Tan Qinhua zhang hao Yang Tao Xing Mingqing Wang Mingbo wu Wenting wu State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical Engineering&Institute of New EnergyChina University of Petroleum(East China)Qingdao 266580China National Engineering Research Center of Coal Gasification and Coal-Based Advanced Materials ShanDong Energy Group CO.LTDJinan 250101China

Photocatalytic oxidation of methane to value-added chemicals is a promising process under mild conditions,nevertheless confronting great challenges in efficiently activating C-H bonds and inhibiting ***,we propose a comprehensive strategy for the selective generation of reactive oxygen species(ROS)by regulating the sizes and facets of Au nanoparticles loaded on *** photocatalytic methane oxidation at ambient temperature,a high oxygenates yield of 36.4 mmol·g^(-1)·h^(-1) with a nearly 100%selectivity has been achieved over the optimized 1.0%Au/znO-9.6(1%Au with(111)facet and 9.6 nm size on znO)photocatalyst,exceeding most reported *** investigations reveal that 1.0%Au/znO-9.6 with the medium size and Au(111)facet guarantees the favourable formation of superoxide radicals(·OOH)through mild oxygen reduction,ultimately leading to excellent photocatalytic methane oxidation *** work provides some guidance for the delicate design of photocatalysts for efficient photocatalytic methane oxidation and oxygen utilization.

关键词： photocatalysis methane oxidation radical regulation oxygen activation nanomaterial

A universal calibration method for eliminating topographydependent current in conductive AFM and its application in nanoscale imaging

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Nano Research 2024年第7期17卷 6509-6517页

作者： Chunlin hao hao Xu Shiquan Lin Yaju zhang Jinmiao He Bei Liu Yuanzheng zhang Banghao wu Guozhen Shen Haiwu zheng Henan Province Engineering Research Center of Smart Micro-nano Sensing Technology and Application School of Physics and ElectronicsHenan UniversityKaifeng 475004China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 100083China

The topography and electrical properties are two crucial characteristics that determine the roles and functionalities of *** atomic force microscopy(CAFM)is widely recognized for its ability to independently measure the topography and *** increasing trend towards miniaturization in electrical devices and sensors has encouraged an urgent demand for enhancing the accuracy of CAFM ***,when performing CAFM tests on Bi_(0.5)Na_(0.5)TiO_(3)bulk ceramic,it is interesting to observe significant currents related to the *** do insulators exhibit“conductivity”in CAFM testing?Herein,we thoroughly investigated the topography-dependent current during CAFM testing for the first *** on the linear dependence between the current and the first derivative of topography,the calibration method has been proposed to eliminate the topographic *** method is evaluated on Bi_(0.5)Na_(0.5)TiO_(3)bulk ceramic,one-dimensional(1D)znO nanowire,twodimensional(2D)NbOI_(2)flake,and biological lotus *** corresponding results of negligible topography-interference current affirm the feasibility and universality of this calibration *** work effectively addresses the challenge of topographic crosstalk in CAFM characterization,thereby preventing the erroneous estimation of the conductivity of any unknown sample.

关键词： conductive atomic force microscopy topographic crosstalk current error calibration method

Gigantic occipital epidermal cyst in a 56-year-old female:A case report

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World Journal of Clinical Cases 2024年第6期12卷 1169-1173页

作者： Yao Wei Peng Chen hao wu Department of Neurosurgery The Second Affiliated Hospital of Xi’an Medical UniversityXi'an 710038Shaanxi ProvinceChina

BACKGROUND Gigantic epidermal cysts(GECs)are rare benign skin appendicular tumours also known as *** have a high incidence and their wall is made up of *** cysts can occur in any part of the skin;clinical manifestations include skin colour hemispherical swelling;cystic;mobile;0.5 cm to several centimetres in diameter;and slow *** SUMMARY Herein,we report a case involving a 56-year-old female with a GEC in the *** July 25,2023,a patient with a GEC was admitted to the neurosurgery Department of the Second Affiliated Hospital of Xi'an Medical *** phyma was shown to be a solid mass during the operation and was confirmed to be a GEC based on pathological *** Epidermal cysts are common cystic nodules on the surface of the body,the aetiology is unclear,the clinical manifestations can vary,and the misdiagnosis rate is ***,giant epidermal cysts are *** most cases,however,the prognosis is *** paper analyses and summarizes the population,location,clinical and pathological characteristics and pathogenesis of the disease to strengthen the understanding of this disease and improve the accuracy of clinical diagnosis.

关键词： Epidermal cyst Occipital Brain Cyst Case report

Multiple types of disease-associated RNAs identification for disease prognosis and therapy using heterogeneous graph learning

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Science China(Information Sciences) 2024年第8期67卷 341-342页

作者： Wenxiang zHANG Hang WEI Wenjing zHANG hao wu Bin LIU School of Computer Science and Technology Beijing Institute of Technology School of Computer Science and Technology Xidian University Department of Teaching and Research Shenzhen University General Hospital Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging National-Regional Key Technology Engineering Laboratory for Medical UltrasoundSchool of Biomedical Engineering Shenzhen University Medical School Advanced Research Institute of Multidisciplinary Science Beijing Institute of Technology

Identifying disease-associated RNAs is crucial in revealing the pathogenic mechanisms of diseases [1], and biologists have made notable progress in this field [2]. However, more effective computational methods are needed to provide reference disease-associated RNAs, reducing the manpower and material resources required for biological experiments.

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