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Preparation of Highly Active Pt-K/γ-Al_2O_3 Catalyst for o-Phenylphenol Synthesis from o-Cyclohexenyl-cyclohexanone Dehydrogenation

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Chemical Research in Chinese Universities 2008年第6期24卷 726-730页

作者： DING Jie-lian LIN Ling XU jian-dong ZENG Chong-yu College of Chemistry and Chemical Engineering Nanjing University of Technology Nanjing 210009 P R. China

0.5%Pt-K/γ-Al2O3 catalysts for the synthesis of o-phenylphenol（OPP） from o-cyclohexenyl-cyclohexanone （dimer） dehydrogenation were prepared by means of a two subsequent impregnation method. The effects of catalyst preparation parameters, such as K promoters, calcination, and reduction conditions, were investigated. The results showed that the addition of K2SO4 to Pt/γ-Al2O3 catalyst notably promoted the selectivity of OPP, and its optimum content was found to be 6% in mass fraction. The higher activity was obtained when Pt/γ-Al2O3 catalyst was calcined in nitrogen atmosphere at 400--500 ℃ and then reduced at the same temperature for 3 h in hydrogen atmosphere. The conversion of the dimer and the selectivity of OPP were always above 99% and 90%, respectively, over 0.5%Pt-6% K2SO4/γ-Al2O3 catalyst during the pilot scale test of 8000 h.

关键词： o-Phenylphenol Pt catalyst K promoters Calcinations Reduction

Accurate simulations of pure-viscoacoustic wave propagation in tilted transversely isotropic media

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Petroleum Science 2024年第2期21卷 866-884页

作者： Qiang Mao jian-Ping Huang Xin-Ru Mu Ji-dong Yang yu-jian Zhang Geosciences Department China University of Petroleum(East China)Qingdao266580ShandongChina Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao266207ShandongChina

Forward modeling of seismic wave propagation is crucial for the realization of reverse time migration(RTM) and full waveform inversion(FWI) in attenuating transversely isotropic media. To describe the attenuation and anisotropy properties of subsurface media, the pure-viscoacoustic anisotropic wave equations are established for wavefield simulations, because they can provide clear and stable wavefields. However, due to the use of several approximations in deriving the wave equation and the introduction of a fractional Laplacian approximation in solving the derived equation, the wavefields simulated by the previous pure-viscoacoustic tilted transversely isotropic(TTI) wave equations has low accuracy. To accurately simulate wavefields in media with velocity anisotropy and attenuation anisotropy, we first derive a new pure-viscoacoustic TTI wave equation from the exact complex-valued dispersion formula in viscoelastic vertical transversely isotropic(VTI) media. Then, we present the hybrid finite-difference and low-rank decomposition(HFDLRD) method to accurately solve our proposed pure-viscoacoustic TTI wave equation. Theoretical analysis and numerical examples suggest that our pure-viscoacoustic TTI wave equation has higher accuracy than previous pure-viscoacoustic TTI wave equations in describing q P-wave kinematic and attenuation characteristics. Additionally, the numerical experiment in a simple two-layer model shows that the HFDLRD technique outperforms the hybrid finite-difference and pseudo-spectral(HFDPS) method in terms of accuracy of wavefield modeling.

关键词： Pure-viscoacoustic TTI wave equation Attenuation anisotropy Seismic modeling Low-rank decomposition method

Block dual Toeplitz Operators on the Orthogonal Complements of Fock Spaces

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1967-1988页

作者： jian Xiang dong Chun Xu XU yu Feng LU School of Mathematical Sciences Dalian University of TechnologyDalian 116024P.R.China School of Mathematics and Information Science Guangzhou UniversityGuangzhou 510006P.R.China

In this paper,we characterize the boundedness and compactness of the block dual Toeplitz operators acting on the orthogonal complement of the Fock spaces,and the compactness of the finite sum of two dual Toeplitz oper... 详细信息

关键词： Block dual Toeplitz operators boundedness compactness Fock space (semi)-commutator

Dual face of axonal inhibitory inputs in the modulation of neuronal excitability in cortical pyramidal neurons

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Neural Regeneration Research 2017年第7期12卷 1079-1085页

作者： Lei jiang Hong Ni Qi-yi Wang Li Huang Shi-di Zhao jian-dong yu Rong-jing Ge Department of Pathophysiology Bengbu Medical College Bengbu Anhui Province China Department of General Surgery The Second Affiliated Hospital of Bengbu Medical College Bengbu Anhui Province China Department of Physiology Bengbu Medical College Bengbu Anhui Province China Guangdong-Hongkong-Macao Institute of CNS Regeneration Joint International Research Laboratory of CNS Regeneration Ministry of Education Jinan University Guangzhou Guangdong Province China

Limited by the tiny structure of axons,the effects of these axonal hyperpolarizing inputs on neuronal activity have not been directly ***,we imitated these processes by simultaneously recording the activities of the somas and proximal axons of cortical pyramidal *** found that spikes and subthreshold potentials propagate between somas and axons with high ***,inhibitory inputs on axons have opposite effects on neuronal activity according to their temporal integration with upstream *** with somatic depolarization,inhibitory inputs on axons decrease neuronal excitability and impede spike *** addition,following action potentials,inhibitory inputs on an axon increase neuronal spike capacity and improve spike *** results indicate that inhibitory inputs on proximal axons have dual regulatory functions in neuronal activity（suppression or facilitation）according to neuronal network patterns.

关键词： nerve regeneration cortex pyramidal neuron soma axon hyperpolarization neuronal network feedforward inhibition temporalintegration feedback inhibition excitability neural regeneration

Influence of pore structure heterogeneity on channeling channels during hot water flooding in heavy oil reservoir based on CT scanning

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Petroleum Science 2024年第4期21卷 2407-2419页

作者： Qing-Jun Du Hao-yu Zheng jian Hou Yong-Ge Liu jian-Fang Sun dong Zhao State Key Laboratory of Deep Oil and Gas China University of Petroleum (East China) School of Petroleum Engineering China University of Petroleum (East China) Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Petroleum Exploration and Production Research Institute

Hot water flooding is an effective way to develop heavy oil reservoirs. However, local channeling channels may form, possibly leading to a low thermal utilization efficiency and high water cut in the reservoir. The pore structure heterogeneity is an important factor in forming these channels. This study proposes a method that mixes quartz sand with different particle sizes to prepare weakly heterogeneous and strongly heterogeneous models through which hot water flooding experiments are *** the experiments, computer tomography(CT) scanning identifies the pore structure and micro remaining oil saturation distribution to analyze the influence of the pore structure heterogeneity on the channeling channels. The oil saturation reduction and average pore size are divided into three levels to quantitatively describe the relationship between the channeling channel distribution and pore structure heterogeneity. The zone where oil saturation reduction exceeds 20% is defined as a channeling *** scanning area is divided into 180 equally sized zones based on the CT scanning images, and threedimensional(3D) distributions of the channeling channels are developed. Four micro remaining oil distribution patterns are proposed, and the morphology characteristics of micro remaining oil inside and outside the channeling channels are analyzed. The results show that hot water flooding is more balanced in the weakly heterogeneous model, and the oil saturation decreases by more than 20% in most zones without narrow channeling channels forming. In the strongly heterogeneous model, hot water flooding is unbalanced, and three narrow channeling channels of different lengths form. In the weakly heterogeneous model, the oil saturation reduction is greater in zones with larger pores. The distribution range of the average pore size is larger in the strongly heterogeneous model. The network remaining oil inside the channeling channels is less than outside the channeling channels,

关键词： Heavy oil Hot water flooding Pore structure Channeling channels CT scanning

Molecularly imprinted sensor based on carboxylated carbon nanotubes/Keggin-type polyoxometalates nanocomposite for the detection of furazolidone

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Tungsten 2024年第2期6卷 394-409页

作者： yu-Lan Huang Bing Zhang yu-Lian Li Li Wang Le dong jian Li College of Ocean Food and Biological Engineering Jimei UniversityXiamen 361021China College of Oceanology and Food Science Quanzhou Normal UniversityQuanzhou 362000China

Due to its properties of mutagenic,teratogenic,and carcinogenic,the detection of furazolidone(FZD)in aquaculture is of great importance for food safety and human *** this study,molecularly imprinted fi lms modifi ed with carboxylated multi-walled carbon nanotube-phosphomolybdic acid composite were used to fabricate an electrochemical sensor for the determination of *** nanocomposites were characterized using infrared spectroscopy,scanning electron microscopy,energy-dispersive X-ray spectroscopy,and X-ray diff *** electrochemical characteristics of the modifi ed electrodes were examined using electrochemical impedance spectroscopy,cyclic voltammetry,and diff erential pulse *** sensor exhibited exceptional catalytic *** calibration curves were acquired in the concentration range of 6 nmol·L^(−1)to 0.6μmol·L^(−1),with a limit of detection of 3.38 nmol·L^(−1).Additionally,the sensor proved successful in recognizing FZD in shrimp samples with satisfactory recoveries and *** method provides a strategy to construct a molecularly imprinted electrochemical sensing platform using nanomaterials,which has great promise in the field of food safety.

关键词： Phosphomolybdate Furazolidone Polyoxometalates Carboxylated multi-walled carbon nanotube Molecularly imprinted polymers Electrochemical sensor

Microbial spectrum and drug resistance of pathogens cultured from gallbladder bile specimens of patients with cholelithiasis:A singlecenter retrospective study

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World Journal of Gastrointestinal Surgery 2022年第12期14卷 1340-1349页

作者： Xiao-Ming Huang Zong-Jin Zhang Nan-Rong Zhang jian-dong yu Xiang-Jun Qian Xian-Hua Zhuo Jia-yu Huang Wei-dong Pan yun-Le Wan Department of Pancreatic-Hepato-Biliary-Surgery The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655Guangdong ProvinceChina Department of Colorectal Surgery The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655Guangdong ProvinceChina Department of Anesthesiology The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655Guangdong ProvinceChina Department of Hepatobiliary Surgery The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655Guangdong ProvinceChina Department of Otorhinolaryngology Sun Yat-sen Memorial HospitalSun Yatsen UniversityGuangzhou 510520Guangdong ProvinceChina Department of Urology The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655Guangdong ProvinceChina

BACKGROUND Bacterial infection is an important cause of cholelithiasis or gallstones and interferes with its *** is no consensus on bile microbial culture profiles in previous studies,and identified microbial spectrum and drug resistance is helpful for targeted preventive and therapeutic drugs in the perioperative *** To analyze the bile microbial spectrum of patients with cholelithiasis and the drug susceptibility patterns in order to establish an empirical antibiotic treatment for cholelithiasis-associated *** A retrospective single-center study was conducted on patients diagnosed with cholelithiasis between May 2013 and December *** This study included 185 patients,of whom 163(88.1%)were diagnosed with gallstones and 22(11.9%)were diagnosed with gallstones and common bile duct stones(CBDSs).Bile culture in 38 cases(20.5%)was *** presence of CBDSs(OR=5.4,95%CI:1.3-21.9,P=0.03)and longer operation time(>80 min)(OR=4.3,95%CI:1.4-13.1,P=0.01)were identified as independent risk factors for positive bile ***-negative bacteria were detected in 28 positive bile specimens,and Escherichia coli(***)(19/28)and Klebsiella pneumoniae(5/28)were the most frequently identified ***-positive bacteria were present in 10 *** resistance rate to cephalosporin in *** was above 42%and varied across *** the isolated *** strains were sensitive to carbapenems,with the exception of one imipenem-resistant *** showed a similar resistance spectrum to *** *** largely sensitive to glycopeptides and penicillin,except for a few strains of *** The presence of common bile duct stones and longer operation time were identified as independent risk factors for positive bile culture in patients with *** most commonly detected bacterium was *** combination ofβ-lactam antibiotics andβ-lactamase inhibitors prescribed perioperatively app

关键词： Bacterial infection Drug resistance Cholelithiasis Gallbladder bile culture

Single-atom Rh catalysts for efficiently degrading Rhodamine B with high concentration

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Rare Metals 2024年第5期43卷 2331-2338页

作者： Shou-Yao Hu jian-Ping Guan Run-Ze Ma yu Tao dong-Hao Liu Jia-Xin Gong yu Xiong Department of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China

Highly concentrated dye wastewater has a serious effect on the quality of natural waters;thus,developing novel catalysts to degrade dyes rapidly and efficiently is of great *** the first time,this study reports an Rh single atom loaded on a nitrogen-doped carbon(SA-Rh/CN)*** catalyst exhibits an excellent processing capacity for high concentrations of Rhodamine B(Rh B),high catalytic activity(95.7% degradation of Rh B in60 min)and excellent stability(93.5% degradation efficiency after 10 stable runs).

关键词： catalyst. catalysts loaded

Study on tungsten sintering temperature field based on electromagnetic simulation and computational fluid dynamics

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Tungsten 2024年第2期6卷 355-366页

作者： Lu-Yan Wang yue-Guang yu jian-Xin dong Kai-Ping Du Shan-yu Liu Cao-Bing Li University of Science and Technology Beijing Beijing 100083China BGRIMM Technology Group Beijing 100160China China Iron&Steel Research Institute Group Beijing 100081China

In order to study the influence of various sintering variables more intuitively and clearly,electromagnetic field analysis and computational fl uid dynamics are used to analyze the infl uence of gas flow,heating power and other process parameters on the temperature range of medium-frequency sintering in this *** results indicate that the uniformity of temperature fi eld is determined by the gas flow rate and heating *** the heating power is 50 kW,the stable temperature drops about 10 K for every 1 m^(3)·h^(−1)increase of hydrogen *** peak value of the maximum temperature diff erence on the tungsten rods gradually increases with the increase of the hydrogen flow rate,and it appears slightly *** temperature distribution of tungsten rods in furnace is similar with diff erent hydrogen flow *** the same time,the closer to the furnace wall,the higher the temperature of the tungsten *** temperature diff erence between tungsten rods mainly occurred within 1 h after the beginning of *** the heating power can improve the stable temperature,but has little eff ect on the heating *** heating power can increase the peak value of the maximum temperature diff erence on the tungsten rods,but has little eff ect on the occurrence time of the peak value of the maximum temperature diff erence on the tungsten *** the heating power will increase the temperature diff erence of a single tungsten rod,but the temperature diff erence of a single tungsten rod never exceeds 65 *** study can be used to guide the process optimization *** with numerical simulation calculation,the sintering parameters with low energy consumption and high temperature uniformity can be quickly and eff ectively found,thus improving the microstructure and properties of sintered tungsten products.

关键词： Tungsten products Sintering Hydrogen flow rate Heating power