检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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(Fe

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

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

在线全文

学校读者我要写书评

暂无评论

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

Availability analysis of private cloud safety computer platform based on the Markov process

在线全文

学校读者我要写书评

暂无评论

Transportation Safety and Environment 2024年第1期6卷 103-108页

作者： Limin fu Jiakun wen Southwest Jiaotong University The School of Information Science&TechnologyChengduSichuan 610097China CRSC Research&Design Institute Group Co. LtdBeijing 100070China

To ensure the correctness of train control system design and development,the ways of simulation,test and formalization were *** to the safe critical attribute of train control system,the characters related to system safety were propounded such as real time,hybrid,distribution(concurrence)and reactivity,and the specific formal methods associated with every character were introduced in *** analysis and classification of the methods were done based on their mathematical basis and applications,and their advantages and disadvantages were *** result indicates that every method has determinate limitations,which is determined by the essences of model checking and theory *** is pointed out that the presentation of new method,the expansion of existing methods and the integration of many methods will be the development trend of formalization in train control system.

关键词： safety computer Markov process cloud computing availability analysis

Evolution of copper species during heat treatment and its effect on CO oxidation reaction on CuCeZrO_(y) catalyst synthesized by a facile solvent-free route

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第4期42卷 660-667页

作者： Guangying fu Dongsen Mao Jun Yu Qiangsheng guo School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai21418 China The ZeoMat Group Qingdao Institute of Bioenergy and Bioprocess TechnologyCASQingdao26611China

Several ternary oxides CuCeZrO_(y)(CCZ)were synthesized by a facile grinding method followed by calcination at high temperatures,and used as catalysts for CO oxidation at low *** influences of calcination temperature(400-600℃)on the physicochemical properties of the assynthesized ternary oxides were investigated by thermogravimetric analysis/differential scanning calorimetry(TGA/DSC),X-ray diffraction(XRD),transmission electron microscopy(TEM),Raman,inductively coupled plasma-optical emission spectrometry(ICP-OES),N_(2) adsorption,H_(2)-temperature programmed reduction(H_(2)-TPR),and X-ray photoelectron spectroscopy(XPS)*** results show that the increase in calcination temperature from 400 to 500℃is conducive to the high dispersion of CuOx on catalyst surface and the incorporation of Cu species into the support to form the Cu-Ce-Zr-O solid *** raising of calcination temperature from 500 to 600℃,however,leads to the segregation of Cu species from the solid solution to aggregate on support surface and growth of highly dispersed CuOx *** highest catalytic activity is acquired over the CCZ calcined at 500℃,which can be ascribed to the largest contents of Cu+species and oxygen vacancies owing to the formation of the maximum amount of Cu-Ce-Zr-O solid solution.

关键词： CuCeZrO_(y)catalyst co oxidation Calcination temperature Grinding method Oxalate precursor Rare earths

Cationic engineered nanodiamonds for efficient antibacterial surface with strong wear resistance

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 939-948页

作者： fu-Kui Li wen-Bo Zhao Yong Wang wen-Tao Huang Ya-Lun Ku Hang Liu Rui guo Hui-Hui Yu Kai-Kai Liu Chong-Xin Shan Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Materials PhysicsMinistry of Educationand School of Physics&MicroelectronicsZhengzhou UniversityZhengzhou 450052China

The spread of diseases caused by bacterial adhesion and immobilization in public places constitutes a serious threat to public *** of bacteria spread by the construction of an antibacterial surface takes precedence over post-infection ***,we demonstrate an effective antibacterial surface with strong wear resistance by constructing cationic engineered nanodiamonds(C-NDs).The C-NDs with positive surface potentials interact effectively with bacteria through electrostatic interactions,where the C-NDs act on the phospholipid bilayer and lead to bacterial membrane collapse and rupture through hydrogen bonding and residual surface oxygen-containing reactive *** this case,bactericidal rate of 99.99%and bacterial biofilm inhibition rate of more than 80%can be achieved with the C-NDs concentration of 1 mg/*** addition,the C-NDs show outstanding antibacterial stability,retaining over 87%of the antibacterial effect after stimulation by adverse environments of heat,acid,and external ***,an antibacterial surface with high wear resistance obtained by integrating C-NDs with commercial plastics has been *** antibacterial surface with a mass fraction of 1 wt.%C-NDs improved abrasion resistance by 3981 times,with 99%killing of adherent *** work provides an effective strategy for highly efficient antibacterial wear-resistant surface,showing great practical applications in public health environments.

关键词： antibacterial surface cationic engineered nanodiamonds wear-resistant

Significantly Enhanced Melt Memory Effect of Metallocene-made Isotactic Polypropylene Containing Talc

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第2期42卷 213-222,I0008页

作者： Hong-wen Sun fu-Shan Wang Yan Gao fu-Qing Wei Jia-Chun Feng State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China Lanzhou Petrochemical Corporation of PetroChina Lanzhou730060China Lanzhou Petrochemical Research Center Petrochemical Research Institute of PetroChinaLanzhou730060China

The melt memory effect is a widely observed phenomenon in semi-crystalline polymers. In practical applications, various additives are usually introduced into polymers, which may affect their melt memory behavior. In this work, the effect of talc on the melt memory effect of metallocene-made isotactic polypropylene(M-PP) was investigated in detail by using the differential scanning calorimetry. The results indicated that the introduction of talc significantly strengthened the melt memory effect of M-PP. Specifically, the upper limit temperature of Domain II increased from 161 ℃ to 174 ℃, resulting in a substantial widening of the temperature range of Domain IIa from 1 ℃ to 14 ℃. Analysis of the crystal orientation of the M-PP containing talc cooled from various Ts suggested that the remarkably enhanced melt memory effect could be ascribed to the stabilization of oriented nuclei facilitated by talc. This stabilizing effect was likely attributable to the prefreezing effect or the sorption interaction between talc and the M-PP chains.

关键词： Metallocene-made isotactic polypropylene Talc Melt memory effect Crystal orientation

In situ embedded bismuth nanoparticles among highly porous carbon fibers for efficient carbon dioxide reduction

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4312-4320页

作者： Wei-Jian guo Ao Zhou wen-wen Cai Jin-Tao Zhang Key Laboratory for Colloid and Interface Chemistry (Ministry of Education) School of Chemistry and Chemical EngineeringShandong University

Electrocatalysis provides an optimal approach for the conversion of carbon dioxide(CO2) into high-value chemicals, thereby presenting a promising avenue toward achieve carbon neutrality. However, addressing the selectivity and stability challenges of metal catalysts in electrolytic reduction remains a daunting task. In this study, the electrospinning method is employed to fabricate porous carbon nanofibers loaded with bismuth nanoparticles with the help of in situ pyrolysis. The porous carbon nanofibers as conductive support would facilitate the dispersion of bismuth active sites while inhibiting their aggregation and promoting the mass transfer, thus enhancing their electrocatalytic activity and stability. Additionally, nitrogen doping induces electron delocalization in bismuth atoms through metal-support interactions, thus enabling efficient adsorption of intermediates for improving selectivity based on the theoretical calculation. Consequently, Bi@PCNF-500 exhibits the exceptional selectivity and stability across a wide range of potential windows. Notably, its faradaic efficiency(FE) of formate reaches 92.7% in H-cell and94.9% in flow cell, respectively, with good electrocatalytic stability. The in situ characterization and theoretical calculations elucidate the plausible reaction mechanism to obtain basic rules for designing efficient electrocatalyst.

关键词： Carbon dioxide reduction Electron delocalization N-doping Porous carbon nanofiber

Effects of Bisphenol A and Its Substitute, Bisphenol F, on the Gut Microbiota in Mice

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第1期37卷 19-30页

作者： MENG Li Ying TAO wen fu LI Jing ZHU Min ZHONG De Bin ZHOU Jing QIN Xue WEI Rong guo Department of Clinical Laboratory The First Affiliated Hospital of Guangxi Medical UniversityNanning 530021GuangxiChina Department of Clinical Laboratory The Fifth Affiliated Hospital of Guangxi Medical UniversityNanning 530021GuangxiChina Jiangsu Key Laboratory of Environmental Engineering Jiangsu Academy of Environmental SciencesNanjing 210000JiangsuChina

Objective The aim of this study was to assess the impact of bisphenol A(BPA)and its substitute,bisphenol F(BPF),on the colonic fecal community structure and function of *** We exposed 6–8-week-old male C57BL/6 mice to 5 mg/(kg∙day)and 50μg/(kg∙day)of BPA or BPF for 14 *** samples from the colon were analyzed using 16S rRNA *** Gut microbiome community richness and diversity,species composition,and function were significantly altered in mice exposed to BPA or *** change was characterized by elevated levels of Ruminococcaceae UCG-010 and Oscillibacter and decreased levels of Prevotella 9 and ***,pathways related to carbohydrate and amino acid metabolism showed substantial *** Mice exposed to different BP analogs exhibited distinct gut bacterial community richness,composition,and related metabolic *** the essential role of gut bacteria in maintaining intestinal homeostasis,our study highlights the intestinal toxicity of BPs in vertebrates.

关键词： Bisphenol A(BPA) Bisphenol F(BPF) 16S rRNA Microbiota

Spontaneous Infection and Periodic Evolving of Domain in a Diffusive SIS Epidemic Model

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第1期40卷 164-191页

作者： Qiang wen guo-qiang Ren Bin Liu School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan430074China

In this paper, we consider a susceptible-infective-susceptible(SIS) reaction-diffusion epidemic model with spontaneous infection and logistic source in a periodically evolving domain. Using the iterative technique,the uniform boundedness of solution is established. In addition, the spatial-temporal risk index R0(ρ) depending on the domain evolution rate ρ(t) as well as its analytical properties are discussed. The monotonicity of R0(ρ)with respect to the diffusion coefficients of the infected dI, the spontaneous infection rate η(ρ(t)y) and interval length L is investigated under appropriate conditions. further, the existence and asymptotic behavior of periodic endemic equilibria are explored by upper and lower solution method. Finally, some numerical simulations are presented to illustrate our analytical results. Our results provide valuable information for disease control and prevention.

关键词： diffusive SIS model spontaneous infection periodically evolving domain periodic endemic equilibrium