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New deep eutectic solvents composed of crown ether, hydroxide and polyethylene glycol for extraction of non-basic N-compounds 被引量:7
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作者 Mohammad Chand Ali Ruirui Liu +5 位作者 Jia Chen Tianpei Cai Haijuan Zhang Zhan Li Honglin Zhai Hongdeng Qiu 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第4期871-874,共4页
Here we firstly report a series of new deep eutectic solvents(DESs) induced by small amounts of crown ether complex and mainly formed by polyethylene glycol. These DESs not only presented the ultra-deep extraction of ... Here we firstly report a series of new deep eutectic solvents(DESs) induced by small amounts of crown ether complex and mainly formed by polyethylene glycol. These DESs not only presented the ultra-deep extraction of non-basic N-compounds from fuel oils, but also opened up the possibility of other new applications in chemistry and materials science. 展开更多
关键词 Deep eutectic solvents EXTRACTION non-basic n-compounds Regeneration Selectivity
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Research on deformation mechanism of AZ31 magnesium alloy sheet with non-basal texture during uniaxial tension at room temperature:A visco-plastic self-consistent analysis 被引量:3
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作者 Li Hu Huyuan Lv +5 位作者 Laixin Shi Yu Chen Qiang Chen Tao Zhou Mingao Li Mingbo Yang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第7期1994-2008,共15页
The relationship between activities of involved deformation mechanisms and the evolution of microstructure and texture during uniaxial tension of AZ31 magnesium alloy with a rare non-basal texture has been thoroughly ... The relationship between activities of involved deformation mechanisms and the evolution of microstructure and texture during uniaxial tension of AZ31 magnesium alloy with a rare non-basal texture has been thoroughly investigated in the present study by means of electron backscattered diffraction(EBSD) measurement and visco-plastic self-consistent(VPSC) modeling. These results show that except basal slip and prismatic slip, {10■2} extension twin(ET) also plays a significant role during plastic deformation. With the increasing tilted angle between loading direction and rolling direction(RD) of sheet, the activity of {10■2} ET possesses a decreasing tendency and its role in plastic deformation changes from the one mainly sustaining plastic strain to the one mainly accommodating local strain between individual grains. When {10■2} ET serves as a carrier of plastic strain, it mainly results in the formation of basal texture component(c-axis//ND, normal direction). By comparison, when the role of {10■2} ET is to accommodate local strain, it mainly brings about the formation of prismatic texture component(c-axis//TD, transverse direction). At large plastic deformation, the competition between basal slip and pyramidal<c+a> slip is responsible for the concentration of tilted basal poles towards ND within all deformed samples. The larger difference is between the activities of basal slip and pyramidal <c+a> slip, the smaller separation is between these two tilted basal poles. Besides,VPSC modeling overesttmates volume fractions of {10■2} ET in samples with angle of 0 to 30° between loading direction and RD of sheet because interactions between twin variants are not included in VPSC modeling procedure at the present form. In addition, as compatible deformation between individual grains cannot be considered in VPSC modeling, the predicted volume fractions of {10■2} ET in samples with angle of 45 to 90° between loading direction and RD of sheet are smaller than the correspondingly measured results. 展开更多
关键词 AZ31 magnesium alloy non-basal texture Plastic deformation VPSC
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Influence of bimodal non-basal texture on microstructure characteristics,texture evolution and deformation mechanisms of AZ31 magnesium alloy sheet rolled at liquid-nitrogen temperature 被引量:4
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作者 Shouzuo Zhang Li Hu +7 位作者 Yutao Ruan Tao Zhou Qiang Chen Yang Zhong Laixin Shi Mingao Li Mingbo Yang Shuyong Jiang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第7期2600-2609,共10页
Cryogenic rolling experiments have been conducted on the AZ31 magnesium(Mg)alloy sheet with bimodal non-basal texture,which is fabricated via the newly developed equal channel angular rolling and continuous bending pr... Cryogenic rolling experiments have been conducted on the AZ31 magnesium(Mg)alloy sheet with bimodal non-basal texture,which is fabricated via the newly developed equal channel angular rolling and continuous bending process with subsequent annealing(ECAR-CB-A)process.Results demonstrate that this sheet shows no edge cracks until the accumulated thickness reduction reaches about 18.5%,which is about 105.6%larger than that of the sheet with traditional basal texture.Characterization experiments including optical microstructure(OM),X-ray diffractometer(XRD),and electron backscatter diffraction(EBSD)measurements are then performed to explore the microstructure characteristics,texture evolution and deformation mechanisms during cryogenic rolling.Experimental observations confirm the occurrence of abundant{10–12}extension twins(ETs),twin-twin interactions among{10–12}ET variants and{10–12}-{10–12}double twins(DTs).The twinning behaviors as for{10–12}ETs are responsible for the concentration of c-axes of grains towards normal direction(ND)and the formation of transverse direction(TD)-component texture at the beginning of cryogenic rolling.The twinning behaviors with respect to{10–12}-{10–12}DTs are responsible for the disappearance of TD-component texture at the later stage of cryogenic rolling.The involved deformation mechanisms can be summarized as follows:Firstly{10–12}ETs dominate the plastic deformation.Subsequently,dislocation slip,especially basal<a>slip,starts to sustain more plastic strain,while{10–12}ETs occur more frequently and enlarge continuously,resulting in the formation of twin-twin interaction among{10–12}ET variants.With the increasing rolling passes,{10–12}-{10–12}DTs incorporate in the plastic deformation and dislocation slip serves as the major one to sustain plastic strain.The activities of basal<a>slip,{10–12}ETs and{10–12}-{10–12}DTs benefit in accommodating the plastic strain in sheet thickness,which contributes to the improved rolling formability in AZ31 Mg alloy sheet with bimodal non-basal texture during cryogenic rolling. 展开更多
关键词 AZ31 Mg alloy Bimodal non-basal texture Cryogenic rolling Microstructure evolution Deformation mechanism
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Clinicopathologic features and related prognosis factors analysis of the basal and non-basal phenotype of triple negative breast cancer
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作者 Lin Sun Lin Zhang Shasha Ren Deding Tao Yaqun Wu 《The Chinese-German Journal of Clinical Oncology》 CAS 2010年第5期249-252,共4页
Objective:Triple-negative breast cancer(estrogen receptor-negative,progesterone receptor-negative and Her2-negative) can be classified into two subtypes:basal and non-basal phenotype.And the basal phenotype is associa... Objective:Triple-negative breast cancer(estrogen receptor-negative,progesterone receptor-negative and Her2-negative) can be classified into two subtypes:basal and non-basal phenotype.And the basal phenotype is associated with poor outcome.The purpose of this study was to figure out the differences of clinicopathological characters and related factors of prognosis between these two subtypes.Methods:Immunohistochemical staining was performed for the CK5/6,CK17 basal markers and EGFR on biopsy samples from 40 triple-negative patients and the clinicopathology features of these samples were investigated.Results:Seventy percent of the patients were diagnosed as the basal phenotype.Compared with the non-basal phenotype,the basal phenotype lesions were significantly larger in diameter with a high nuclear grade.In the node-negative group the basal phenotype clearly showed the same clinicopathological differences.There was statistically significant concordance among all three antibodies.Conclusion:Expression of basal markers identifies a biologically and clinically distinct subgroup of TN tumors,justifying the use of basal markers to define the basal or the non-basal phenotype.It is important to help the doctor deciding the therapeutic strategy for patient with triple-negative breast cancer. 展开更多
关键词 breast cancer TRIPLE-NEGATIVE basal phenotype non-basal phenotype CLINICOPATHOLOGY PROGNOSIS
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Enhancing the strain hardening and ductility of Mg-Y alloy by introducing stacking faults 被引量:11
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作者 Kang Wei Lirong Xiao +6 位作者 Bo Gao Lei Li Yi Liu Zhigang Ding Wei Liu Hao Zhou Yonghao Zhao 《Journal of Magnesium and Alloys》 SCIE EI CAS 2020年第4期1221-1227,共7页
Due to the insufficient slip systems,Mg and its alloys exhibit poor ductility during plastic deformation at room temperature.To solve this problem,alloying is considered as a most effective method to improve the ducti... Due to the insufficient slip systems,Mg and its alloys exhibit poor ductility during plastic deformation at room temperature.To solve this problem,alloying is considered as a most effective method to improve the ductility of Mg alloys,which attracts wide attentions of industries.However,it is still a challenge to understand the ductilization mechanism,because of the complicated alloying elements and their interactions with Mg matrix.In this work,pure Mg and Mg-Y alloys were comparatively studied to investigate the effect of Y addition on microstructure evolution and mechanical properties.A huge increase of uniform elongation,from 5.3%to 20.7%,was achieved via only 3 wt%addition of yttrium.TEM results revealed that the only activated slip system in pure Mg was basalslip,led to its poor ductility at room temperature.In contrast,a large number of stacking faults and non-basal dislocations with<c>component were observed in the deformed Mg-Y alloy,which was proposed as the main reason for significant improvement of strain hardening and ductility.High resolution TEM indicated that most of the stacking faults were II and 12 intrinsic faults,which played a critical role in improving the ductility of Mg-Y alloy.Addition of Y into Mg alloy decreased the stacking fault energy,which induced high density stacking faults in the grain interior. 展开更多
关键词 Magnesium alloys DUCTILITY Stacking faults non-basal slip Transmission electron microscopy
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Effect of 1Al addition on deformation behavior of Mg 被引量:7
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作者 Ji Hyun Hwang A.Zargaran +3 位作者 Gyeongbae Park O.Lee B.-J.Lee Nack J.Kim 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第2期489-498,共10页
Deformation behavior of 1 Al containing Mg alloy has been investigated in the present study.After annealing,the Mg-1 Al alloy shows a typical basal texture.When compared to the pure Mg having a similar texture and gra... Deformation behavior of 1 Al containing Mg alloy has been investigated in the present study.After annealing,the Mg-1 Al alloy shows a typical basal texture.When compared to the pure Mg having a similar texture and grain size,the Mg-1 Al alloy shows much higher strength and larger elongation.Slip trace analyses of the tensile strained specimens show that non-basal slips such as pyramidal I and II slips can be easily activated at an early stage of deformation in the Mg-1 Al alloy and the grains in the Mg-1 Al alloy are seen to accommodate a larger degree of deformation than those in the pure Mg at a given strain.With increasing tensile strain,however,there is a strain localization along the initially formed slip lines of non-basal slips,forming surface steps without activating multiple slip lines. 展开更多
关键词 Deformation behavior Slip trace analysis non-basal slip Strain localization DUCTILITY
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Underlying slip/twinning activities of Mg-xGd alloys investigated by modified lattice rotation analysis 被引量:2
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作者 Biaobiao Yang Chenying Shi +7 位作者 Xianjue Ye Jianwei Teng Ruilin Lai Yujie Cui Dikai Guan Hongwei Cui Yunping Li Akihiko Chiba 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第3期998-1015,共18页
The inconsistencies regarding the fundamental correlation between Gd content and slip(twinning)activities of Mg alloys appeal further investigations.However,the traditional slip dislocations analysis by TEM is time-co... The inconsistencies regarding the fundamental correlation between Gd content and slip(twinning)activities of Mg alloys appeal further investigations.However,the traditional slip dislocations analysis by TEM is time-consuming,and that by SEM/EBSD cannot recognize the partial slip modes.These urge a more efficient and comprehensive approach to easily distinguish all potential slip modes occurred concurrently in alloy matrix.Here we report a modified lattice rotation analysis that can distinguish all slip systems and provide statistical results for slip activities in Mg alloy matrix.Using this method,the high ductility of Mg-Gd alloy ascribed to the enhanced non-basal slips,cross-slip,and postponed twinning activities by Gd addition is quantitatively clarified. 展开更多
关键词 Mg-Gd alloy non-basal slips Postponed twinning Grain boundary segregation Modified lattice rotation analysis
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Supercritical Water as a Reaction Medium for Nitrogen-Containing Heterocycles 被引量:1
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作者 Wahyudiono Yui Matsunaga +2 位作者 Siti Machmudah Mitsuru Sasaki Motonobu Gotol 《Journal of Chemistry and Chemical Engineering》 2012年第10期897-910,共14页
Supercritical water has been focused on as an environmentally attractive reaction media, in which organic materials can be decomposed into smaller molecules. The reaction behavior of pyrrole as a simple model compound... Supercritical water has been focused on as an environmentally attractive reaction media, in which organic materials can be decomposed into smaller molecules. The reaction behavior of pyrrole as a simple model compound of nonbasic nitrogen compounds found in petroleum residua was studied in supercritical water with a batch type reactor. The reaction was carried out at temperatures of 698-748 K and at various pressures under an argon atmosphere. The chemical species in the aqueous products were identified by GCMS (gas chromatography mass spectrometry) and quantified using GC-FID (gas chromatography flame ionization detector). The effect of temperature and reaction time on the conversion process of pyrrole is presented. Under supercritical water conditions, pyrrole underwent successful decomposition in water into its derived compounds. The conversion of pyrrole could approach 81.12 wt% at 723 K and 40 MPa within 240 min of reaction time. The decomposition process was accelerated with the existence of water at the same temperature. Ultimate analysis of solid products was also conducted using a CHN analyzer. The process investigated in this study may form the basis for an efficient method of nitrogen compound decomposition in future. 展开更多
关键词 Supercritical water PYRROLE HYDRODENITROGENATION non-basic aromatic nitrogen compound conversion.
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Effect of twinning on flow stress during initial stage of hot compression of twin roll cast Mg-5.51Zn-0.49Zr alloy
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作者 刘志义 徐静 +1 位作者 侯延辉 KANG S.B. 《Journal of Central South University》 SCIE EI CAS 2010年第2期197-201,共5页
A Thermecmastor-Z hot deformation simulator,optical microscopy,XRD and TEM were employed to characterize the flow stress behavior and microstructure of twin roll cast ZK60 magnesium alloy during initial stage of hot c... A Thermecmastor-Z hot deformation simulator,optical microscopy,XRD and TEM were employed to characterize the flow stress behavior and microstructure of twin roll cast ZK60 magnesium alloy during initial stage of hot compression at elevated temperature of 300 ℃ and 400 ℃ and a given strain rate of 10-2s-1.The results suggest that flow stress drop during initial stage of hot compression at 300℃,generally led by dynamic recrystallization,is attributed to twinning,correspondingly to dynamic recrystallization as deformation temperature is raised to 400 ℃. 展开更多
关键词 magnesium alloy basal slip non-basal slip TWINNING hot deformation recrystallization
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Combined insertion of basic and non-basic amino acids at hemagglutinin cleavage site of highly pathogenic H7N9 virus promotes replication and pathogenicity in chickens and mice
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作者 Aobaixue Zhou Jiahao Zhang +10 位作者 Huanan Li Qiang Xu Yiqun Chen Bo Li Wanying Liu Guanming Su Xingxing Ren Guangjie Lao Baozheng Luo Ming Liao Wenbao Qi 《Virologica Sinica》 SCIE CAS CSCD 2022年第1期38-47,共10页
Since mid-2016,the low pathogenic H7N9 influenza virus has evolved into a highly pathogenic(HP)phenotype in China,raising many concerns about public health and poultry industry.The insertion of a“KRTA”motif at hemag... Since mid-2016,the low pathogenic H7N9 influenza virus has evolved into a highly pathogenic(HP)phenotype in China,raising many concerns about public health and poultry industry.The insertion of a“KRTA”motif at hemagglutinin cleavage site(HACS)occurred in the early stage of HP H7N9 variants.During the co-circulation,the HACS of HP-H7N9 variants were more polymorphic in birds and humans.Although HP-H7N9 variants,unlike the H5 subtype virus,exhibited the insertions of basic and non-basic amino acids,the underlying function of those insertions and substitutions remains unclear.The results of bioinformatics analysis indicated that the PEVPKRKRTAR/G motif of HACS had become the dominant motif in China.Then,we generated six H7N9 viruses bearing the PEIPKGR/G,PEVPKGR/G,PEVPKRKRTAR/G,PEVPKGKRTAR/G,PEVPKGKRIAR/G,and PEVPKRKRR/G motifs.Interestingly,after the deletion of threonine and alanine(TA)at HACS,the H7N9 viruses manifested decreased thermostability and virulence in mice,and the PEVPKRKRTAR/G-motif virus is prevalent in birds and humans probably due to its increased transmissibility and moderate virulence.By contrast,the insertion of non-basic amino acid isoleucine and alanine(IA)decreased the transmissibility in chickens and virulence in mice.Remarkably,the I335V substitution of H7N9 virus enhanced infectivity and transmission in chickens,suggesting that the combination of mutations and insertions of amino acids at the HACS promoted replication and pathogenicity in chickens and mice.The ongoing evolution of H7N9 increasingly threatens public health and poultry industry,so,its comprehensive surveillance and prevention of H7N9 viruses should be pursued. 展开更多
关键词 H7N9 Highly pathogenic Cleavage site Basic and non-basic amino acids PATHOGENICITY
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Dependence of Microstructure Evolution and Mechanical Properties on Loading Direction for AZ31 Magnesium Alloy Sheet with Non-basal Texture During In-Plane Uniaxial Tension 被引量:1
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作者 Li Hu Mingao Li +3 位作者 Qiang Chen Tao Zhou Laixin Shi Mingbo Yang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2022年第2期223-234,共12页
In-plane uniaxial tension of AZ31 magnesium alloy sheet with non-basal texture has been conducted in order to demonstrate the effects of loading direction on the microstructure evolution and mechanical properties at a... In-plane uniaxial tension of AZ31 magnesium alloy sheet with non-basal texture has been conducted in order to demonstrate the effects of loading direction on the microstructure evolution and mechanical properties at ambient temperature.Loading axes are chosen to be along five directions distributed between rolling direction(RD)and transverse direction(TD),allowing various activities in involved slip and twinning modes to take place.As for twinning modes,electron backscattered diffraction observations confirm that the contribution of{1011}compression twinning is minimal to the plastic deformation of all deformed samples.By comparison,{1012}extension twinning(ET)not only serves as an important carrier on sustaining and accommodating plastic strain but also contributes to the emergence of TD-component texture with the progression of plastic strain.In terms of slip modes,analysis on Schmid factor demonstrates that the increasing tilted angle between loading direction and RD of sheet is unfavorable to the activation of basalslip,whereas it contributes to the activation of prismaticslip.These observations consequently explain the increasing tendency of 0.2%proof yield stress.Moreover,the activations of basalslip and{1012}ET collectively contribute to the concentration of two tilted basal poles toward normal direction.With increasing angle between loading direction and RD,the activations of basalslip and{1012}ET are gradually weakened.This leads to a weakening tendency about concentration of two tilted basal poles,a generally increasing tendency about Lankford value(r-value)and a generally decreasing tendency about strain-hardening exponent(n-value). 展开更多
关键词 AZ31 magnesium alloy non-basal texture Plastic deformation Microstructure evolution
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Newly observed irrational crystallographic features of non-basal Mg_(2)Sn precipitates in a Mg-4Sn alloy aged at 160℃
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作者 Xuefei Huang Baoqin Fu Weigang Huang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第18期237-243,共7页
Two novel types of irrational orientation relationships(ORs)betweenβ-Mg_(2)Sn precipitates and theα-Mg matrix were observed in a Mg-4 Sn alloy aged at 160℃.In contrast to that for the dominantβ-Mg_(2)Sn laths lyin... Two novel types of irrational orientation relationships(ORs)betweenβ-Mg_(2)Sn precipitates and theα-Mg matrix were observed in a Mg-4 Sn alloy aged at 160℃.In contrast to that for the dominantβ-Mg_(2)Sn laths lying on the(0001)_αbasal plane of the matrix,the precipitates with the irrational ORs are inclined or normal to(0001)_α.Specifically,the precipitates that adopt the OR of[011]_(β)//[2110]_α,with(111)_(β)deviating approximately 4.7°from(0002)_α,have a long axis parallel to[0001]_α.The precipitates with the OR of[011]_(β)//[2110]_α,with(111)_(β)deviating approximately 13.50 from(0002)_α,exhibit a long axis of[0211]_α.Both types of precipitates have a habit plane(HP)of(2110)_α.The interface orientations of the precipitates associated with the irrational ORs are interpreted by a good matching sites(GMS)method.A thorough examination of the crystallographic features of theβ-Mg_(2)Sn precipitates in the literature shows that the precipitates with most rational ORs have a HP parallel to(0001)_α,and those with most irrational ORs have a HP(or long axis)inclined or normal to(0001)_α.The preferences of the precipitates with different irrational ORs have also been analyzed by examining the lattice matching condition across the interfaces between the precipitates and the matrix. 展开更多
关键词 Mg alloy non-basal precipitates CRYSTALLOGRAPHY Good matching sites Orientation relationship β-Mg_(2)Sn
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HDPairFinder:A data processing platform for hydrogen/deuterium isotopic labeling-based nontargeted analysis of trace-level amino-containing chemicals in environmental water
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作者 Tingting Zhao Kristin Carroll +5 位作者 Caley B.Craven Nicholas J.P.Wawryk Shipei Xing Jian Guo Xing-Fang Li Tao Huan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第2期583-593,共11页
The combination of hydrogen/deuterium(H/D)formaldehyde-based isotopic methyl labeling with solid-phase extraction and high-performance liquid chromatography–high resolution mass spectrometry(HPLC-HRMS)is a powerful a... The combination of hydrogen/deuterium(H/D)formaldehyde-based isotopic methyl labeling with solid-phase extraction and high-performance liquid chromatography–high resolution mass spectrometry(HPLC-HRMS)is a powerful analytical solution for nontargeted analysis of trace-level amino-containing chemicals in water samples.Given the huge amount of chemical information generated in HPLC-HRMS analysis,identifying all possible H/Dlabeled amino chemicals presents a significant challenge in data processing.To address this,we designed a streamlined data processing pipeline that can automatically extract H/D-labeled amino chemicals from the raw HPLC-HRMS data with high accuracy and efficiency.First,we developed a cross-correlation algorithm to correct the retention time shift resulting from deuterium isotopic effects,which enables reliable pairing of H-and D-labeled peaks.Second,we implemented several bioinformatic solutions to remove false chemical features generated by in-source fragmentation,salt adduction,and natural13C isotopes.Third,we used a data mining strategy to construct the AMINES library that consists of over 38,000 structure-disjointed primary and secondary amines to facilitate putative compound annotation.Finally,we integrated these modules into a freely available R program,HDPairFinder.R.The rationale of each module was justified and its performance tested using experimental H/D-labeled chemical standards and authentic water samples.We further demonstrated the application of HDPairFinder to effectively extract N-containing contaminants,thus enabling the monitoring of changes of primary and secondary N-compounds in authentic water samples.HDPairFinder is a reliable bioinformatic tool for rapid processing of H/D isotopic methyl labeling-based nontargeted analysis of water samples,and will facilitate a better understanding of N-containing chemical compounds in water. 展开更多
关键词 Isotope labeling Nontargeted analysis Reactive n-compounds HPLC-HRMS Source water
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Mg-Sc-Nd-xZn series alloys with medium strength and high plasticity
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作者 Fulong Xue Zhuangzhuang Feng +5 位作者 Yubo Gao Di Mei Baolin Chang Jianfeng Wang Shijie Zhu Shaokang Guan 《Journal of Rare Earths》 SCIE EI CAS CSCD 2024年第12期2362-2373,I0006,共13页
Different application scenarios put forward diverse requirements of mechanical properties for magnesium alloys.In this study,the extruded Mg-Sc-Nd-Zn alloy series with high plasticity and medium strength was developed... Different application scenarios put forward diverse requirements of mechanical properties for magnesium alloys.In this study,the extruded Mg-Sc-Nd-Zn alloy series with high plasticity and medium strength was developed.The uniformly distributed Mg_(3)Nd(β_(1))phase,high-density twins,and the activated non-basal dislocation slips contribute to the high plasticity of Mg-Sc-Nd alloy.With the addition of Zn element,the appearance of coarse ScZn phases,which prevents the activation of{1012}tensile twins,leads to an increase in strength but a simultaneous decrease in the plasticity of the extruded alloys.Adjusting the Zn content in the Mg-Sc-Nd-xZn allows a series of alloys with various strengths and plasticity matching.The results obtained in this work are of great importance for developing a regulatable magnesium alloy series that aims at different application scenarios. 展开更多
关键词 Magnesium alloy Tension twin non-basal slip High plasticity Rare earths
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Simultaneously enhancing the strength and ductility of as-extruded AlN/AZ91 composites via nano-precipitation and pyramidal slip
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作者 Bin Zhang Yunxia Sun +5 位作者 Tuo Liang Yunzhen Li Tian Li Jingchao Wang Ruiru Cai Changlin Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第5期240-254,共15页
Age hardening is often used to optimize the mechanical properties of as-deformed Mg-based materials in industry,whereas the improvement of strength is usually accompanied by the significant loss of ductility,which hin... Age hardening is often used to optimize the mechanical properties of as-deformed Mg-based materials in industry,whereas the improvement of strength is usually accompanied by the significant loss of ductility,which hinders the application of Mg-based materials in structural components.In the present work,high strength-ductility synergy(the yield strength of 263±9 MPa,ultimate tensile strength of 398±7 MPa and elongation to fracture of 34%±1%)was realized in as-extruded AlN/AZ91 composites after optimiz-ing aging processes.Microstructural characterization shows that AlN particles induced a large number of geometrically necessary dislocations around the AlN/Mg interface during extrusion,which decreased the nucleation barrier and provided more heterogeneous nucleation sites forγ-Mg 17 Al 12 continuous precipi-tation.Meanwhile,95%of residual dislocations in as-extruded AlN/AZ91 composites were annihilated dur-ing peak-aging,suppressing the growth and coarsening of continuous precipitates.Therefore,high density of nano-sizedγ-Mg 17 Al 12 continuous precipitates was produced in as-extruded AlN/AZ91 composites af-ter peak-aging.During tension,gliding dislocations bypassed sphericalγ-Mg 17 Al 12 nano-precipitates by Orowan looping rather than cutting mechanism,which induced a strong block on dislocation motion.So high yield strength was mainly attributed to the high density of non-shearableγ-Mg 17 Al 12 nano-precipitates with spherical morphology,which was different from other Mg-Al-based systems.The results of texture evolution and slip trace analysis demonstrated that the suppression of extension twinning and less basal slip was due to the enhanced activity of pyramidalc+aslip in as-extruded AlN/AZ91 com-posites after peak-aging during the room temperature tension,meanwhile,the dislocation density of as-extruded AlN/AZ91 composites was significantly decreased during peak-aging,then higher elongation to fracture was achieved. 展开更多
关键词 Magnesium matrix composites Mechanical properties Precipitation Deformation mechanisms non-basal slip
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Weakened anisotropy of mechanical properties in rolled ZK60 magnesium alloy sheets with elevated deformation temperature 被引量:5
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作者 Wenke Wang Wenzhen Chen +2 位作者 Wencong Zhang Guorong Cui Erde Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2018年第11期2042-2050,共9页
The rolling direction(RD) and the transverse direction(TD) samples were obtained from an as-rolled ZK60 magnesium alloy sheet with strong anisotropy of initial texture and their mechanical properties were tested a... The rolling direction(RD) and the transverse direction(TD) samples were obtained from an as-rolled ZK60 magnesium alloy sheet with strong anisotropy of initial texture and their mechanical properties were tested at various deformation temperatures. Meanwhile, the microstructure and texture of these samples after fracture were investigated. Results revealed that a higher flow stress along the RD than that along the TD at room temperature were ascribed to the strong anisotropy of transitional texture, and this texture effect was remarkably weakened with the increase of deformation temperature. Deformation structure was dominant at 100℃, and was replaced by dynamic recrystallization structure when the deformation temperature increased to 200℃ and 300℃. The texture presented a strong texture(transitional texture in the RD sample and basal texture in the TD sample) at 100℃, but its intensity visibly decreased and texture components became more disperse at 200℃ and 300℃. These microstructure and texture results were employed in conjunction with calculated results to argue that raising deformation temperature could increase the activity of non-basal slip by tailoring the relative critical resolved shear stress of each deformation mode and finally result in low texture effect on mechanical anisotropy. 展开更多
关键词 ZK60 magnesium alloy Deformation temperature Texture anisotropy Dynamic recrystallization non-basal slip
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Seed provenance determines germination responses of Rumex crispus (L.) under water stress and nutrient availability
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作者 María Pérez-Fernández Carole PElliott +1 位作者 Alex Valentine JoséAntonio Oyola 《Journal of Plant Ecology》 SCIE CSCD 2019年第6期949-961,共13页
Aims Seeds of Rumex crispus from six provenances were studied in relation to their germination under drought and presence of nitrogen in the germination and emergence media.We also investigated whether adaptation to s... Aims Seeds of Rumex crispus from six provenances were studied in relation to their germination under drought and presence of nitrogen in the germination and emergence media.We also investigated whether adaptation to soil increases the ability of the species to colonize and establish in contrasting environments along a longitudinal gradient in western Spain by means of a reciprocal transplantation experiment.Methods We conducted a germination trial in the lab to test for the germination responses to water scarcity along a polyethylene glycol gradient and to varying concentrations of nitrogen compounds.Simultaneously reciprocal transplantations experiment was conducted,where seeds from six provenances were grown in the soils from the very same provenances.Seedling emergence,survivorship and fitness-related variables were measured in all plots.Important Findings We found that R.crispus has a cold-stratification requirement that enhances its germination.Significant differences between the six provenances were detected for time-to-germination,total seedling emergence,plant mortality and reproductive effort in all the experiments.The differences between provenances with respect to germination were confirmed by the significant statistical analyses of the variance,thus providing evidence that seeds from parent plants grown in different environmental conditions have an intrinsically different abilities to germinate and establish.Soil nitrogen content where seed germination and seedlings establish also play an important role in their performance in terms of survivorship and reproduction,being the higher levels of inorganic nitrogen and of microbial biomass those that increased biomass production,enhanced inflorescence formation and reduced plant mortality.We conclude that one of the main reasons for the spread and maintenance of R.crispus would be the increased levels of nitrogen in agricultural soils. 展开更多
关键词 seed provenance GERMINATION latitudinal gradient DROUGHT n-compounds soil properties
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In Situ Electron Backscatter Diff raction Analysis for Microstructure Evolution and Deformation Models of Mg–Ce Alloy During Uniaxial Loading
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作者 Fang-Wei Jiao Li Jin +1 位作者 Jie Dong Feng-Hua Wang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2019年第2期263-268,共6页
Previous studies showed that signifi cant increases in elongation in Mg–Ce alloys due to the Ce addition and the solute drag eff ect by Ce addition were ascribed to the non-basal dislocation slip activating and the t... Previous studies showed that signifi cant increases in elongation in Mg–Ce alloys due to the Ce addition and the solute drag eff ect by Ce addition were ascribed to the non-basal dislocation slip activating and the texture altering. The microstructure evolution and deformation models of extruded Mg-0.5 wt%Ce alloy rods under uniaxial tension have been studied using in situ electron backscatter diff raction. The basal and non-basal slips were characterized by using slip line trace analysis. The results provide evidence for that pyramidal slip activated during deformation, besides basal slip and extension twinning, which contributes to the texture weakening and ductility increasing in Mg-0.5 wt%Ce alloy. 展开更多
关键词 Texture non-basal SLIP TWINNING In SITU ELECTRON backscattered diff raction(EBSD) Trace ANALYSIS
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Dominant Deformation Mechanisms in Mg–Zn–Ca Alloy
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作者 Tao Ying Mingdi Yu +3 位作者 Yiwen Chen Huan Zhang Jingya Wang Xiaoqin Zeng 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2022年第12期1973-1982,共10页
The coaddition of Zn and Ca has great potential to improve the ductility of Mg alloys.Herein,the mechanical properties of an extruded Mg-Zn-Ca solid-solution alloy were studied by quasi-in situ electron backscatter di... The coaddition of Zn and Ca has great potential to improve the ductility of Mg alloys.Herein,the mechanical properties of an extruded Mg-Zn-Ca solid-solution alloy were studied by quasi-in situ electron backscatter diffraction(EBSD)-assisted slip trace analysis.The dominant deformation mechanisms of the Mg-Zn-Ca alloy were studied,and the origins of enhanced ductility were systematically revealed.The results indicate that most grains deformed by basal slip.In addition,multiple non-bas al slip traces were detected(particularly prismatic,pyramidal I,and pyramidal I<c+a>slip traces),and their activation frequency was promoted with increasing tensile strain.The enhanced participation of non-basal slip systems is believed to play a critical role in achieving homogeneous plastic deformation,thus effectively promoting the ductility of the Mg-Zn-Ca alloy.Furthermore,first-principle calculations revealed that the coaddition of Zn and Ca significantly reduces the unstable stacking fault energy for non-basal slip,which contributes to the activation of non-basal slip systems during plastic deformation. 展开更多
关键词 Mg-Zn-Ca alloy non-basal slip activities First-principle calculations Generalized stacking fault energy Deformation mechanisms
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