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Impact Toughness of an NM400 Wear-Resistant Steel

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Journal of Iron and Steel Research International 2013年第8期20卷 72-77页

作者： SONG hong-yu li Can-ming LAN liang-yun zhao De-wen wang Guo-dong State Key Laboratory of Rolling and Automation Northeastern University Laiwu Iron and Steel Group Co. Ltd.

An NM400 wear-resistant steel was hot rolled and then the plates were heat-treated by direct quenching and tempering （DQT） and reheat quenching and tempering （RQT） techniques, respectively. The Charpy impact test was carried out with an instrumented Charpy impact tester. The microstructure and fracture surface were investiga-ted by a combination of optical microscopy, transmission electron microscopy and scanning electron microscopy methods. It was found that the impact toughness of DQT specimen was much higher than that of RQT specimen. The microstructure of both DQT and RQT specimens was characterized by a mixture of tempered lath martensite and lower hainite. The lower bainite in DQT specimen extended into prior austenite grains and the content was higher than that in RQT specimen. The lower bainite in DOT specimen improved the impact toughness by increasing the proportion of large-angle boundaries and relieving the stress concentration at the crack tip. A number of fine and dis-persed carbides in DQT specimen also contributed to the improvement of the impact toughness.

关键词： impact toughness direct quenching tempering lower bainite martensite packet

Effects of B_2O_3 and CaF_2 on Melting Temperatures of CaO-SiO_2-Fe_2O_3 System Fluxes

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Journal of Iron and Steel Research International 2013年第6期20卷 21-24页

作者： wang hong-ming YANG li-li li Gui-rong ZHU Xiang ZHU Hua zhao yu-tao School of Materials Science and Engineering Jiangsu University Jiangsu Shasteel Group

Fluorite is widely employed as fluxing agent in metallurgy flux , which inevitably leads to serious fluorine pollution.B2O3 is employed as fluxing agent of CaO-SiO2-Fe2O3steelmaking fluxes to substitute for *** effects of B2O3 and CaF2 on the melting properties of this system were *** melting temperatures of fluxes including softening temperature （Ts）, hemispherical temperature （Th）, and flow temperature （Tf） were measured using the hemisphere *** results indicate that the fluxing effect of B2O3is more significant than that of CaF2 .When the addition amount of B2O3 （mass percent） exceeds 6% , the melting temperatures of fluxes including Ts , Th and Tf are decreased lower than 1 300℃.The basicity of fluxes has a significant effect on the melting temperature , and the melting temperatures of the fluxes increase with the increase of fluxes *** , when B2O3 is used as fluxing agent , the melting temperature changes little with the basicity increasing from 2.5 to 5.0. These characteristics are suitable for steelmaking *** , Fe2O3 has an important fluxing effect on this CaO-based steelmaking *** indicates that the fluxes system is suitable for steelmaking process.

关键词： boron oxide calcium fluoride melting temperature CaO-SiO2-Fe2O3 system steelmaking flux

Coercivity enhancement of hot-deformed Nd-Fe-B magnets with Pr-Cu alloy addition

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Rare Metals 2023年第4期42卷 1403-1407页

作者： Jun-ming wang zhao-Hui Guo Zheng Jing Xiao Du Neng-Jun yu Meng-yu li ming-Gang Zhu Wei li Division of Functional Materials Central Iron&Steel Research InstituteBeijing100081China

Effects of low-melting Pr-Cu alloy addition on the microstructure and magnetic properties of the hot-deformation Nd-Fe-B magnets were investigated.A small amount of Pr-Cu addition enhances the coercivity of the hot-deformation Nd-Fe-B magnets *** coercivity of the hotdeformation Nd-Fe-B magnets with 4.0 wt%Pr_(85)Cu_(15)addition increases to 1271 kA·m^(-1),75.69%higher than that of Pr-Cu-free magnet(723 kA·m^(-1)),and then decreases with5 wt%Pr_(85)Cu_(15)*** is observed that there a uniform RE-rich phase is formed wrapping the Nd2Fe14B main phase in the sample with 4.0%Pr_(85)Cu_(15)addition by scanning electron microscopy(SEM),which promotes the *** angular dependence of coercivity for the hot-deformation Nd-Fe-B magnets indicates that the coercivity mechanism is nucleation combined with domain wall *** domain wall pinning is weakened,while the nucleation is enhanced after Pr-Cu ***,intrinsic coercivity,and maximum magnetic energy product of the original Nd-Fe-B magnet are 1.45 T,723 kA·m^(-1),and 419.8 kJ·m^(-3),respectively,and those of the sample with 4.0%Pr_(85)Cu_(15)alloy addition are 1.30 T,1271 kA·m^(-1),and 330.0 kJ·m^(-3),respectively.

关键词： Nd-Fe-B Low-melting alloy Hot-deformation Microstructure Coercivity mechanism

Multiphase flow inside a four-strand continuous casting tundish using three types of ladle shrouds

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Journal of Iron and Steel Research International 2023年第6期30卷 1171-1181页

作者： Jiang-shan Zhang Bang-ming Qin yu-hong liu Quan-hui li Xiao-tan Zuo Chao wang Shu-feng Yang Qing liu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China Research Institute Nanjing Iron and Steel Co.Ltd.Nanjing 210035JiangsuChina Wuhu Xinxing Ductile Iron Pipes Co. Ltd.Wuhu 241002AnhuiChina School of Advanced Engineering University of Science and Technology BeijingBeijing 100083China

Numerical and physical models have been built and validated to study the multiphase flow inside three ladle shrouds and a four-strand tundish.A conventional straight ladle shroud and two types of trumpet-shaped ladle shroud(TLS)have been comparatively *** maximum velocity at ladle shroud outlet reduces from 1.3 to 0.5 m/s,which indicates a quieter tundish *** is demonstrated that the use of a TLS can also decrease the maximum surface velocity from 0.16 to 0.13 m/s,which reduces the tendency of forming tundish open *** flow pattern and mixing behavior are improved inside the tundish,especially in enlarging the plug volume from 6.61%to 9.04%.The difference between the near and far outlets is narrowed when the TLS is applied.A computational program was developed to calculate characteristic parameters of different ladle shroud designs,and a dimensionless index was proposed to evaluate their mass and inner *** trials have been carried out,and the results showed that TLS can reduce level fluctuation in the pouring zone,which is beneficial to promoting better protective performance from secondary contamination and heat loss during continuous casting.

关键词： Tundish metallurgy Multiphase flow Ladle shroud Modeling Plant trial

Rapid identification of Psathyrostachys huashanica Keng chromosomes in wheat background based on ND-FISH and SNP array methods

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Journal of Integrative Agriculture 2023年第10期22卷 2934-2948页

作者： li Jia-chuang li Jiao-jiao zhao li zhao Ji-xin WU Jun CHEN Xin-hong ZHANG li-yu DONG Pu-hui wang li-ming zhao De-hui wang Chun-ping PANG yu-hui College of Agronomy Henan University of Science and TechnologyLuoyang 471023P.R.China The Shennong Laboratory Henan ProvienceZhengzhou 450002P.R.China College of Agronomy Northwest A&F UniversityYangling 712100P.R.China

Psathyrostachys huashanica Keng(2n=2x=14,NsNs)is regarded as a valuable wild relative species for common wheat cultivar improvement because of its abundant beneficial agronomic ***,although the development of many wheat–***-derived lines provides a germplasm base for the transfer of excellent traits,the lag in the identification of *** chromosomes in the wheat background has limited the study of these *** this study,three novel nondenaturing fluorescence in situ hybridization(ND-FISH)-positive oligo probes were *** them,HS-TZ3 and HS-TZ4 could specifically hybridize with *** chromosomes,mainly in the telomere area,and HS-CHTZ5 could hybridize with the chromosomal centromere *** sequentially constructed a *** FISH karyotype and idiogram that helped identify the homologous groups of introduced *** *** detail,1Ns and 2Ns had opposite signals on the short and long arms,3Ns,4Ns,and 7Ns had superposed two-color signals,5Ns and 6Ns had fluorescent signals only on their short arms,and 7Ns had signals on the intercalary of the long *** addition,we evaluated different ways to identify alien introgression lines by using low-density single nucleotide polymorphism(SNP)arrays and recommended the SNP homozygosity rate in each chromosome as a statistical *** 15K SNP array is widely applicable for addition,substitution,and translocation lines,and the 40K SNP array is the most accurate for recognizing transposed intervals between wheat and alien *** research provided convenient methods to distinguish the homologous group of *** chromosomes in a common wheat background based on ND-FISH and SNP arrays,which is of great significance for efficiently identifying wheat–***-derived lines and the further application of Ns chromosomes.

关键词： Psathyrostachys huashanica Ns chromosomes ND-FISH SNP array common wheat

Permeability and heterogeneity adaptability of surfactant-alternating-gas foam for recovering oil from low-permeability reservoirs

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Petroleum Science 2022年第3期19卷 1185-1197页

作者： ming-Chen Ding Qiang li yu-Jing yuan Ye-Fei wang Ning zhao yu-Gui Han School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongP.R.China Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)) Ministry of EducationQingdao266580ShandongP.R.China Research Institute of Petroleum Engineering Technology Shengli Oilfield CompanyDongying257000ShandongP.R.China Bohai Oilfield Research Institute Tianjin Branch of CNOOC Ltd.Tianjin300450P.R.China

As the traditional polymer stabilizer is eliminated to improve the injectability of foam in lowpermeability reservoirs,the stability,plugging capacity,conformance control and oil recovery performance of the surfactant-alternating-gas(SAG)foam become significantly important for determining its adaptability to permeability and heterogeneity,which were focused and experimentally researched in this *** show that the SAG bubbles are highly stable in micron-sized channels and porous media(than in the conventional unconstrained graduated cylinder),making it possible to use in enhanced oil recovery(EOR).Such bubbles formed in porous media could be passively adjusted to match their diameter with the size of the *** endows the SAG foam with underlying excellent injectability and deep migration *** adaptability results indicate a reduced plugging capacity,but,increased incremental oil recovery by the SAG foam with decreased *** makes it a good candidate for EOR over a wide range of permeability,however,parallel core floods demonstrate that there is a limiting heterogeneity for SAG application,which is determined to be a permeability contrast of 12.0(for a reservoir containing oil of 9.9 m Pa s).Beyond this limit,the foam would become ineffective.

关键词： SAG foam EOR Low-permeability reservoir Permeability Heterogeneity

Synthesis, Crystal Structure and Insecticidal Activities of Novel Neonicotinoid Derivatives

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Chemical Research in Chinese Universities 2010年第3期26卷 380-383页

作者： zhao yu wang Gang li Yong-qiang wang Su-hua li Zheng-ming State Key Laboratory of Elemento-Organic Chemistry Research Institute of Elemento-Organic Chemistry National Pesticide Engineering Research Center（Tianjin） Nankai University Tianjin 300071 P. R. China

Ten new N-oxalyl derivatives of neonicotinoid compound were designed and synthesized. Their structures were confirmed by ^1H NMR spectra, elemental analysis and X-ray diffraction. The preliminary insecticidal activities of the new compounds were evaluated. The results of bioassays indicate that the title Compounds exhibit moderate insecticidal activities. Surprisingly, the insecticidal activity of compound 7b against bean aphids at 200 mg/kg is 100%, which is comoarable to that of the commercialized imidacloprid.

关键词： Neonicotinoid N-Oxalyl derivative Insecticidal activity Bean aphid Imidacloprid

Colorless to black switching with high contrast ratio via the electrochemical process of a hybrid organic-inorganic perovskite

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Carbon Energy 2023年第11期5卷 90-100页

作者： ming Xu Jianmin Gu Zixun Fang yu li Xing wang Xiaoyu zhao Tifeng Jiao Wei wang State Key Laboratory of Metastable Materials Science and Technology(MMST) Hebei Key Laboratory of Applied ChemistryYanshan UniversityQinhuangdaoChina Department of Food and Pharmaceutical Engineering Suihua UniversitySuihuaChina Department of Chemistry Centre for PharmacyUniversity of BergenBergenNorway

Colorless‐to‐black switching has attracted widespread attention for smart windows and multifunctional displays because they are more useful to control solar ***,it still remains a challenge owing to the tremendous difficulties in the design of completely reverse absorptions in transmissive and colored ***,we report on an electrochemical device that can switch between colorless and black by using the electrochemical process of hybrid organic–inorganic perovskite MAPbBr_(3),which shows a high integrated contrast ratio of up to 73%from 400 to 800 *** perovskite solution can be used as the active layer to assemble the device,showing superior transmittance over the entire visible region in neutral *** applying an appropriate voltage,the device undergoes reversible switching between colorless and black,which is attributed to the formation of lead and Br_(2)in the redox reaction induced by the electron transfer process in MAPbBr_(3).In addition,the contrast ratio can be modulated over the entire visible region by changing the concentration and the applied *** results contribute toward gaining an insightful understanding of the electrochemical process of perovskites and greatly promoting the development of switchable devices.

关键词： colorless to black switching electrochemical process high integrated contrast ratio hybrid organic-inorganic perovskite switchable devices

South drying and north wetting over the Tibetan Plateau modulated by a zonal temperature dipole across timescales

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Advances in Climate Change Research 2023年第2期14卷 276-285页

作者： Ru-Cong yu Jian li ming-ming ZHANG Ni-Na li Yin zhao State Key Laboratory of Severe Weather and Institute of Tibetan Plateau Meteorology Chinese Academy of Meteorological SciencesBeijing 100081China Department of Meteorology University of ReadingReading RG66AHUK National Meteorological Center China Meteorological AdministrationBeijing 100081China

Precipitation over the Tibetan Plateau and surrounding highlands is a crucial process in the hydrological cycle and is very important for local and downstream ecology,and previous research mainly focused on a certain range of timescales.A better understanding of the variability across various timescales,which has been largely ignored,can provide new insight on the regional weather and ***,a north‒south dipole pattern of precipitation shaped by a zonal dipole of the upper-tropospheric temperature is revealed in this *** dipole patterns of the precipitation and the accompanied temperature exist from daily to interdecadal *** three-dimensional circulation anomalies connecting the temperature and precipitation dipoles are consistent across various *** frequencies of daily events with opposite phases of the temperature dipole modulate the interannual and interdecadal variability in *** south drying and north wetting pattern over the Tibetan Plateau is an interdecadal manifestation of the precipitation dipole and can be ascribed to the temperature trend favourable for the positive phase of the zonal temperature *** consistent dipole pattern constructs a more complete portrayal of precipitation over the Tibetan Plateau from synoptic scale to climatology.

关键词： Tibetan plateau Dipole of precipitation Daily scale Interannual scale Interdecadal scale