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Effects of operating parameters on the flow field in slab continuous casting molds with narrow widths

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International Journal of Minerals,Metallurgy and Materials 2021年第2期28卷 238-248页

作者： Tao Zhang Jian Yang Gang-jun Xu hong-jun liu jun-jun Zhou Wei Qin State Key Laboratory of Advanced Special Steel Shanghai UniversityShanghai 200444China Hunan Valin Lianyuan Iron&Steel Co. Ltd.Loudi 417000China

Computational simulations and high-temperature measurements of velocities near the surface of a mold were carried out by using the rod deflection method to study the effects of various operating parameters on the flow field in slab continuous casting(CC)molds with narrow widths for the production of automobile exposed *** agreement between the calculated results and measured subsurface velocities of liquid steel was obtained under different operating parameters of the CC *** simulation results reveal that the flow field in the horizontal plane located 50 mm from the meniscus can be used as the characteristic flow field to optimize the flow field of molten steel in the *** in casting speed can increase the subsurface velocity of molten steel and shift the position of the vortex core downward in the downward circulation *** flow field of liquid steel in a 1040 mm-wide slab CC mold can be improved by an Ar gas flow rate of 7 L·min^−1 and casting speed of 1.7 m·min^−*** the present experimental conditions,the double-roll flow pattern is generally stable at a submerged entry nozzle immersion depth of 170 mm.

关键词： flow field rod deflection method continuous casting narrow width numerical simulation operating parameters

Development of a micro gas turbine combustor with T-type vaporizers

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航空动力学报 2007年第7期22卷 1118-1126页

作者： XU Quan-hong liu jun XU Jian LIN Yu-zhen liu Gao-en National Key Laboratory on Aero-Engines School of Jet PropulsionBeijing 13niversity of Aeronautics and Astronautics Beijing 100083 China

The study includes the experimental investigation of the evaporation performance of T-type vaporizer,mainly studied the relationship of the inlet air temperature and vaporizer wall temperature with the evaporation ***,it studied the LBO(lean blow out) and combustion efficiency of the micro aero-engine combustor with T-type vaporizer on the normal pressure test *** inlet air condition is environmental pressure and *** gas analysis method is used to study the combustion efficiency,and the inlet air temperature is 300 K,400 K and 500 *** could be concluded that the evaporation performance is improved with the increasing of the inlet air temperature and vaporizer wall temperature;the average LBO is 0.003;the combustion efficiency rises with the inlet air temperature,and it remain constant when the fuel/air ratio changed in the range from 0.008 to *** vaporization ratio is the key factor to determine the combustion performance.

关键词：离心式喷气发动机燃烧室喷雾器索特平均直径燃气涡轮

Chemical Quenching of Positronium in CuO/Al2O3 Catalysts

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Chinese Physics Letters 2011年第1期28卷 193-196页

作者： ZHANG hong-jun liu Zhe-Wen CHEN Zhi-Quan WANG Shao-Jie Hubei Nuclear Solid Physics Key Laboratory Department of Physics Wuhan University Wuhan 430072

CuO/Al2O3 catalysts were prepared by mixing CuO and environment of the catalysts are characterized by positron v-AI203 nanopowders. Microstrueture and chemical annihilation spectroscopy. The positron annihilation lifetime measurements reveal two long lifetime components 73 and τ4, which correspond to ortho-positronium （o- Ps） annihilating in mierovoids and large pores, respectively. With increasing CuO content from 0 to 40 wt%, both 3-4 and its intensity I4 show significant decrease, which indicates quenching effect of o-Ps. The para-positronium （p-Ps） intensities derived from multi-Gaussian fitting of the coincidence Doppler broadening spectra also decreases gradually with increasing CuO content. This excludes the possibility of spin-conversion of positronium. Therefore, the chemicM quenching by CuO is probably responsible for the decrease of o-Ps lifetime. Variation in the o-Ps annihilation rate A4 （1/T4） as a function of CuO content can be well fitted by a straight line, and the slope of the fitting line is （1.83 ± 0.05） × 10^7 s-1.

关键词： Catalysts Chemicals Measurement

Remission of hepatotoxicity in chronic pulmonary aspergillosis patients after lowering trough concentration of voriconazole

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World Journal of Clinical Cases 2020年第20期8卷 4700-4707页

作者： Guo-Jie Teng Xiang-Rong Bai Lin Zhang hong-jun liu Xiu-hong Nie Department of Pulmonary and Critical Care Medicine Xuanwu Hospital Capital Medical UniversityBeijing 100053China Pharmacy Department Xuanwu Hospital Capital Medical UniversityBeijing 100053China Department of Evidence-based Medicine Xuanwu Hospital Capital Medical UniversityBeijingChinaBeijing 100053China

BACKGROUND Chronic pulmonary aspergillosis(CPA)is a rare syndrome that is often accompanied by gradual lung tissue *** is usually employed as the first-line agent for CPA ***,some patients can develop hepatotoxicity and often were forced to stop voriconazole *** To record the improving trend of liver function and the therapeutic effects in patients after lowering the trough concentration of *** This study retrospectively analyzed 12 adult CPA patients who developed hepatotoxicity during the voriconazole *** these patients,the oral dose was reduced to 3/4 or 1/2 of the standard dose(4 mg/kg,twice daily),and the lower limit of voriconazole trough concentration was maintained more than 0.5μg/m *** trend of remission of liver toxicity after drug reduction in 12 patients was *** the same period,25 patients who received standard doses served as the control *** from the two groups were collected and analyzed for different parameters such as demographic characteristics,underlying pulmonary disorders,laboratory tests,and therapeutic *** differences between the two groups were statistically *** Hepatotoxicity occurred in 12 patients within 28-65 d after oral voriconazole *** was mainly manifested by the significantly increased level of gamma-glutamyltransferase and a slight increase of alanine aminotransferase and aspartate *** oral dose of voriconazole was reduced to approximately 3 mg/kg in seven patients and approximately 2 mg/kg in five *** average trough concentrations for the 12 patients before and after voriconazole oral dose reduction were 3.17±1.47μg/m L(1.5-6.0μg/m L)and 1.70±0.78μg/m L(0.6-3.3μg/m L),respectively(P=0.02).After lowering the trough concentrations,the hepatotoxicity was alleviated in all the ***,gamma-glutamyltransferase levels declined *** 4 mo of treatment,7 of the 12 pat

关键词： Voriconazole Hepatotoxicity Chronic pulmonary aspergillosis CYP2C19 genotypes Reduction Trough concentration

Unraveling role of double-exchange interaction in electrochemical water oxidation by external magnetic field

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Rare Metals 2024年第1期43卷 289-297页

作者： jun Li jun-Ming Li hong hong Dong-Xue liu Qing-Qi Cao Dun-Hui Wang National Laboratory of Solid State Microstructures and Jiangsu Provincial Key Laboratory for Nanotechnology Nanjing UniversityNanjing 210093China School of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018China

Double-exchange(DE) interaction plays an important role in electrocatalytic oxygen evolution reaction(OER).However,precise achievement of DE interaction often requires foreign dopants or vacancy engineering,leading to destabilization of the catalysts and deterioration of *** contrast,the utilization of environmentally friendly,contactless,and continuously adjustable magnetic fields to study the OER process is profitable to avoid aforementioned interference factors and further elucidate the direct relationship_(0.5)between DE interaction and OER ***,by using cobalt hydroxide carbonate(Co(OH)(CO_(3))·xH_(2)O,CoHC) nanostructures as a proof-of-concept study,external magnetic fields are carefully implemented to verify the role of DE interaction during water oxidation *** studies reveal that external magnetic fields effectively enhance the reaction rate of the catalyst,the overpotential decreases from 386 to 355 mV(100 mA·cm^(-2)),while Tafel slopes drastically decline from 93 to 67 mV·dec^(-1)(1.0 T).Moreover,magnetic field increment exhibits robust *** in situ Raman and impedance measurements under external field,it can be found that magnetic field promotes the electron migration between Co^(2+) and Co^(3+) in the CoHC catalysts with the assistance of DE interactions,thus boosting the OER efficiency.

关键词： Magnetic field Double-exchange(DE)interaction Electrocatalysis Oxygen evolution reaction(OER) Cobalt hydroxide carbonate

Lepithiohydimerins A-D:Four Pairs of Neuroprotective Thiohydantoin Dimers Bearing a Disulfide Bond from Maca(Lepidium meyenii Walp.)

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Chinese Journal of Chemistry 2021年第10期39卷 2738-2744页

作者： Xing-Rong Peng Ran-Ran Zhang jun-hong liu Zhong-Rong Li Lin Zhou Ming-Hua Qiu State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan650201 China University of the Chinese Academy of Sciences Beijing 100049China

Main observation and conclusion An HPLC-UV-guided separation was performed and four pairs of unprecedented macathiohydantoin dimers,lepithiohydimerins A—D(1—4)bearing a rare disulfide bond were isolated from the tubers of *** structures were unambiguously confirmed by NMR spectroscopic,X-ray crystallographic and electronic circular dichroism(ECD)*** the concentration of 20μmol/L,compounds 2-1,2-2,and 4-1 increased the viability of PC12 cells with the cell viability at(72.06±1.14)%,(72.64±1.49)%,and(70.93±1.22)%,***,the serial concentration experiment showed that they can protect PC12 cells in a dose-dependent manner.

关键词： Lepidium meyenii Walp. Thiohydantoin dimers Natural products Structure elucidation Biological activity

Substructure Prediction from Infrared Spectra by Using Support Vector Machines

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Chinese Chemical Letters 2005年第10期16卷 1354-1356页

作者： jun hong liu Min Chun LU Fu Sheng NIE Xiao Yu FENG Meng Long LI College of Chemistry Sichuan University Chengdu 610064

The potential of support vector machines （SVMs） for the substructure elucidation of infrared spectra have been investigated. The trained SVMs can identify the 16 substructures with high accuracy.

关键词： Infrared spectra substructures support vector machines.

Enhanced hydrogen evolution reaction in FePt film with remanence due to decrease in domain walls

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Rare Metals 2024年第3期43卷 1108-1115页

作者： hong hong Dong-Xue liu jun Li jun-Ming Li Li-Qian Wu Bo Yang Qing-Qi Cao Dun-Hui Wang National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced MicrostructuresJiangsu Provincial Key Laboratory for NanotechnologySchool of PhysicsNanjing UniversityNanjing210093China Hangzhou Dianzi University Hangzhou310018China Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang110819China

As an effective strategy to improve the properties of electrocatalysts,magnetic field-assisted electrocatalytic water splitting has attracted increasing attention ***,the corresponding enhancements mostly depend on the exertion of an external magnetic field during electrochemical reactions,which results in a high cost of industrial production,and makes the magnetic field manipulation of electrocatalysis become a challenging *** this work,instead of the external magnetic field,a bias magnetic field is self-supplied by the remanence state of a ferromagnetic electrocatalyst of *** to the assistance of this bias magnetic field,the FePt film in the remanence state shows the overpotential of 229 mV during hydrogen evolution reaction,which is much lower than that in its demagnetization state(283 mV).Our findings demonstrate that the remanence in ferromagnetic electrocatalysts can improve the catalytic performance,which is attributed to the decrease in domain walls.

关键词： Remanence Magnetic domains Electrocatalysis Hydrogen evolution reaction(HER)

A New Epidithiodioxopiperazine Metabolite Isolated from Gliocladium roseum YMF1.00133

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Chinese Chemical Letters 2006年第7期17卷 922-924页

作者： Jin Yah DONG Wei ZHOU Lei LI Guo hong LI Ya jun liu Ke Qing ZHANG Laboratory for Conservation and Utilization of Bioresources Yunnan University Kunming 650091

Glioclatine, a novel epidithiodioxopiperazine was isolated from wheat solid-substrate fermentation of Gliocladium roseum YMF1.00133. Its structure was elucidated by HRESI-MS and NMR spectra.

关键词： Glioclatine epidithiodioxopiperazine Gliocladium roseum.