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| 1 | One-step synthesis and electromagnetic absorption properties of high entropy rare earth hexaborides(HE REB6)and high entropy rare earth hexaborides/borates(HE REB6/HE REB03)composite powders显示文摘Considering the emergence of severe electromagnetic interference problems,it is vital to develop electromagnetic(EM)wave absorbing materials with high dielectric,magnetic loss and optimized impedance matching.However,realizing the synergistic dielectric and magnetic losses in a single phase material is still a challenge.Herein,high entropy(HE)rare earth hexaborides(REB6)powders with coupling of dielectric and magnetic losses were designed and successfully synthesized through a facial one-step boron carbide reduction method,and the effects of high entropy borates intermedia phases on the EM wave absorption properties were investigated.Five HE REB6 ceramics including(Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6,(Ce0.2Hu0.2Sm0.2Er0.2Yb0.2)B6,(Ce0.2Y0.2Eu0.2Er0.2Yb0.2)B6,(Ce0.2Ya2Sm0.2Eu0.2Yb0.2)B6,and(Nd0.2Y0.2Sm0.2Eu0.2Yb0.2)B6 possess CsCl-type cubic crystal structure,and their theoretical densities range from 4.84 to 5.25 g/cm^(3).(Ce02Y0.2Sm0.2Er0.2Yb02)B6 powders with the average particle size of 1.86 jim were found to possess the best EM wave absorption properties among these hexaborides.The RLmin value of(Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6 reaches-33.4 dB at 11.5 GHz at thickness of 2 mm;meanwhile,the optimized effective absorption bandwidth(EAB)is 3.9 GHz from 13.6 to 17.5 GHz with a thickness of 1.5 mm.The introduction of HE REB03(RE=Ce,Y,Sm,Eu,Er,Yb)as intermediate phase will give rise to the mismatching impedance,which will further lead to the reduction of reflection loss.Intriguingly,the HEREB6/HEREB03 still possess wide effective absorption bandwidth of 4.1 GHz with the relative low thickness of 1.7 mm.Considering the better stability,low density,and good EM wave absorption properties,HE REB6 ceramics are promising as a new type of EM wave absorbing materials. | Weiming ZHANG Biao ZHAO Huimin XIANG Fu-Zhi DAI Shijiang WU Yanchun ZHOU | 2021 | Journal of Advanced Ceramics2021，10，1： | 15 |
| 2 | Electromagnetic wave absorbing properties of TMCs(TM=Ti,Zr,Hf,Nb and Ta)and high entropy(Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C显示文摘Electromagnetic wave(EMW)absorbing materials play a vital role in modern communication and information processing technologies to inhibit information leakage and prevent possible damages to environment and human bodies.Currently,most of EMW absorbing materials are either composites of two or more phases or in the form of nanosheets,nanowires or nanofibers in order to enhance the EMW absorption performance through dielectric loss,magnetic loss and dielectric/magnetic loss coupling.However,the combination of complex shapes/multi phases and nanosizes may compound the difficulties of materials processing,composition and interfaces control as well as performance maintenance during service.Thus,searching for single phase materials with good stability and superior EMW absorbing properties is appealing.To achieve this goal,the EMW absorbing properties of transition metal carbides TMCs(TM=Ti,Zr,Hf,Nb and Ta)and high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C which belong to ultrahigh temperature ceramics,were investigated in this work.Due to the good electrical conductivity and splitting of d orbitals into lower energy t2glevel and higher energy eglevel in TMC6octahedral arrangement,TMCs(TM=Ti,Zr,Hf,Nb and Ta)exhibit good EMW absorbing properties.Especially,Hf C and Ta C exhibit superior EMW absorbing properties.The minimum reflection loss(RLmin)value of Hf C is-55.8 d B at 6.0 GHz with the thickness of 3.8 mm and the effective absorption bandwidth(E_(AB))is 6.0 GHz from 12.0 to 18.0 GHz at thickness of 1.9 mm;the RL_(minvalue)of Ta C reaches-41.1 d B at 16.2 GHz with a thickness of 2.0 mm and the EABis 6.1 GHz with a thickness of 2.2 mm.Intriguingly,the electromagnetic parameters,i.e.,complex permittivity and permeability are tunable by forming single phase solid solution or high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C.The R_(Lminvalue)of high entropy(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))C is-38.5 d B at 9.5 GHz with the thickness of 1.9 mm,and the EABis 2.3 GHz(from 11.3 to 13.6 GHz)at thickness of 1.5 mm.The significance of this work is that it opens a new window to design single phase high performance EMW absorbing materials by dielectric/magnetic loss coupling through tuning the conductivity and crystal field splitting energy of d orbitals of transition metals in carbides,nitrides and possibly borides. | Yanchun Zhou Biao Zhao Heng Chen Huimin Xiang Fu-Zi Dai Shijiang Wu Wei Xu | 2021 | Journal of Materials Science & Technology2021，，15： | 13 |
| 3 | High entropy rare earth hexaborides/tetraborides(HE REB_(6)/HE REB_(4)) composite powders with enhanced electromagnetic wave absorption performance显示文摘The increasing electromagnetic hazards including electromagnetic interference and electromagnetic pollution,which were stemmed from massive usage of electromagnetic technology,have triggered widespread concerns.To cope with this challenge,electromagnetic wave absorbing materials with high performance are greatly needed.Composite construction has been widely applied in electromagnetic(EM)wave absorbing materials to achieve high permittivity,high permeability and impedance matching.However,high-temperature stability,oxidation and corrosion resistance are still unignorable issues.Herein,high entropy hexaborides/tetraborides(HE REB_(6)/HE REB_(4))composites with synergistic dielectric and magnetic losses were designed and successfully synthesized through a one-step boron carbide reduction method.The five as-prepared(Y_(0.2) Nd_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2))B_(6)/(Y_(0.2) Nd_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2))B_(4),(Y_(0.2) Nd_(0.2) Sm_(0.2) Er_(0.2) Yb_(0.2))B_(6)/(Y_(0.2) Nd_(0.2) Sm_(0.2) Er_(0.2) Yb_(0.2))B_(4),(Y_(0.2) Nd_(0.2) Eu_(0.2) Er_(0.2) Yb_(0.2))B_(6)/(Y_(0.2) Nd_(0.2) Eu_(0.2) Er_(0.2) Yb_(0.2))B_(4),(Nd_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2) Yb_(0.2))B_(6)/(Nd_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2) Yb_(0.2))B_(4) and(Y_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2) Yb_(0.2))B_(6)/(Y_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2) Yb_(0.2))B_(4) contain two phases of HE REB_(6) and HE REB_(4).Among them(Y_(0.2) Nd_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2))B_(6)/(Y_(0.2) Nd_(0.2) Sm_(0.2) Eu_(0.2) Er_(0.2))B_(4)(HE REB_(6)/HE REB_(4)-1)and(Y_(0.2) Nd_(0.2) Sm_(0.2) Er_(0.2) Yb_(0.2))B_(6)/(Y_(0.2) Nd_(0.2) Sm_(0.2) Er_(0.2) Yb_(0.2))B_(4)(HE REB_(6)/HE REB_(4)-2)exhibit excellent EM wave absorption properties.The optimal minimum reflection loss(RL_(m in))and effective absorption bandwidth(E_(AB))of HE REB_(6)/HE REB_(4)-1 and HE REB_(6)/HE REB_(4)-2 are–53.3 dB(at 1.7 mm),4.2 GHz(at 1.5 mm)and–43.5 dB(1.3 mm),4.2 GHz(1.5 mm),respectively.The combination of conducting HE REB_(4) with magnetism into HE REB_(6) as a second phase enhances dielectric and magnetic losses,which lead to enhanced EM wave absorption performance.Considering superior high-temperature stability,oxidation and corrosion resistance of HE REB_(6) and HE REB_(4),HE REB_(6)/HE REB_(4) composite ceramics are promising as a new type of high-performance EM wave absorbing materials. | Weiming Zhang Biao Zhao Na Ni Huimin Xiang Fu-Zhi Dai Shijiang Wu Yanchun Zhou | 2021 | Journal of Materials Science & Technology2021，，28： | 9 |
| 4 | Diagnosis and surgical treatment of intraveneous leiomyomatosis extending into the heart:two cases report and review of the literature显示文摘Objective:To investigate the clinical characteristics,diagnosis and surgical treatment of intravenous leiomyomatosis(IVL),and outline the differences between Chinese and overseas cases.Methods:Clinical data of two IVL cases,treated in our hospital,were analyzed retrospectively and the related literature was also reviewed.The data of preoperative diagnostic rate,surgical procedures,and postoperative recurrence between patients in China and other countries were compared.Results:The first stage operation was performed successfully in 2 patients.However,they refused subsequent therapies,including a second stage operation to excise the remnants of the tumor,uterus,bilateral oviducts and ovaries,and anti-estrogen therapy.Both suffered from IVL recurrence,one at 6-month and the other at 9-month,and died at 16-month and 12-month respectively after the first stage surgery.Worldwide reports of 110 IVL cases were reviewed,which included 28 cases in China and 82 cases in other countries.In the majority of the Chinese patients,tumors only extended into the right atrium rather than the right ventricle(RA 22 cases vs RV 4 cases).However,among the overseas patients,the rate of extension into the right atrium was similar to that of extension into the right ventricle(RA 41 cases vs RV 38 cases).The rate of hysterectomies was not significantly different between Chinese and overseas patients(67.86% vs 55.9%,P=0.278).The rate of correct preoperative diagnosis in the Chinese patients was significantly lower than that in the overseas patients(32.14% vs 80%,P=0.000002),as well as the rate of complete excision of the tumor(22.7% vs 75.5%,P=0.000001).The proportion of patients who undergoing a single-stage or a two-stage operation was similar in Chinese and overseas patients.The recurrence rate was significantly higher in the Chinese patients than in the overseas patients(36.8% vs 9.1%,P=0.0055),and the patients with tumor recurrence were partial tumor excision patients.Conclusion:The possibility of IVL should be considered if echocardiography in female patients demonstrates a tumor in the right heart and a mass in the inferior vena cava(IVC).Further imaging should be performed to confirm the diagnosis.The correct diagnosis and accurate preoperative delineation of tumor extension are essential for an optimal surgical outcome.The key point in IVL treatment is the complete excision of tumors(single-stage or two-stage surgical procedure). | Xiaowei Wang Lin Zhang Yijiang Chen Shijiang Zhang Jianwei Qin Yanhu Wu Jinhua Luo | 2009 | Journal of Nanjing Medical University2009，23，5： | 5 |
| 5 | Achieving ultra-broadband electromagnetic wave absorption in high-entropy transition metal carbides (HE TMCs)显示文摘Electronic devices pervade everyday life,which has triggered severe electromagnetic(EM)wave pollution.To face this challenge,developing EM wave absorbers with ultra-broadband absorption capacity is critically required.Currently,nano-composite construction has been widely utilized to realize impedance match and broadband absorption.However,complex experimental procedures,limited thermal stability,and interior oxidation resistance are still unneglectable issues.Therefore,it is appealing to realize ultra-broadband EM wave absorption in single-phase materials with good stability.Aiming at this target,two high-entropy transition metal carbides(HE TMCs)including(Zr,Hf,Nb,Ta)C(HE TMC-2)and(Cr,Zr,Hf,Nb,Ta)C(HE TMC-3)are designed and synthesized,of which the microwave absorption performance is investigated in comparison with previously reported(Ti,Zr,Hf,Nb,Ta)C(HE TMC-1).Due to the synergistic effects of dielectric and magnetic losses,HE TMC-2 and HE TMC-3 exhibit better impedance match and wider effective absorption bandwidth(EAB).In specific,the exclusion of Ti element in HE TMC-2 endows it optimal minimum reflection loss(RL_(min))and EAB of−41.7 dB(2.11 mm,10.52 GHz)and 3.5 GHz(at 3.0 mm),respectively.Remarkably,the incorporation of Cr element in HE TMC-3 significantly improves the impedance match,thus realizing EAB of 10.5,9.2,and 13.9 GHz at 2,3,and 4 mm,respectively.The significance of this study lays on realizing ultra-broadband capacity in HE TMC-3(Cr,Zr,Hf,Nb,Ta),demonstrating the effectiveness of high-entropy component design in tailoring the impedance match. | Weiming ZHANG Huimin XIANG Fu-Zhi DAI Biao ZHAO Shijiang WU Yanchun ZHOU | 2022 | Journal of Advanced Ceramics2022，11，4： | 5 |
| 6 | Preparation of Layered Potassium Titanate Whiskers with Large Length-diameter Ratio by KDC Method显示文摘Pure K2Ti4O9 whiskers were prepared by KDC(Kneading-Drying-Calcination) method with TiO2 and K2CO3 as raw materials. The influences of TiO2/K2CO3 molar ratio(RT/K), calcination temperature(TC) and cooling process on phase composition and morphology of the whiskers were investigated by TG-DSC(thermo gravimetric-differential scanning calorimeter), XRD(X-ray diffraction), and SEM(scanning electron microscope). Pure K2Ti4O9 potassium titanate whiskers with large length-diameter ratio(r)(over 250) can be obtained at RT/K = 2.9 and TC = 950 ℃. | 吉晓莉 WU Shijiang 章嵩 ZHAO Xiujian | 2014 | Journal of Wuhan University of Technology(Materials Science)2014，29，4： | 4 |
| 7 | Enabling highly efficient and broadband electromagnetic wave absorption by tuning impedance match in high-entropy transition metal diborides (HETMB_(2))显示文摘The advance in communication technology has triggered worldwide concern on electromagnetic wave pollution.To cope with this challenge,exploring high-performance electromagnetic(EM)wave absorbing materials with dielectric and magnetic losses coupling is urgently required.Of the EM wave absorbers,transition metal diborides(TMB2)possess excellent dielectric loss capability.However,akin to other single dielectric materials,poor impedance match leads to inferior performance.High-entropy engineering is expected to be effective in tailoring the balance between dielectric and magnetic losses through compositional design.Herein,three HE TMB2 powders with nominal equimolar TM including HE TMB2-I(TM=Zr,Hf,Nb,Ta),HE TMB2-2(TM=Ti,Zr,Hf,Nb,Ta),and HE TMB2-3(TM=Cr,Zr,Hf,Nb,Ta)have been designed and prepared by one-step boro/carbothermal reduction.As a result of synergistic effects of strong attenuation capability and impedance match,HE TMB2-1 shows much improved performance with the optimal minimum reflection loss(RL_(min))of-59.6 dB(8.48 GHz,2.68 mm)and effective absorption bandwidth(EAB)of 7.6 GHz(2.3 mm).Most impressively,incorporating Cr in HE TMB2-3 greatly improves the impedance match over 1-18 GHz,thus achieving the RLmin of-56.2 dB(8.48 GHz,2.63 mm)and the EAB of 11.0 GHz(2.2 mm),which is superior to most other EM wave absorbing materials.This work reveals that constructing high-entropy compounds,especially by incorporating magnetic elements,is effectual in tailoring the impedance match for highly conductive compounds,i.e.,tuning electrical conductivity and boosting magnetic loss to realize highly efficient and broadband EM wave absorption with dielectric and magnetic coupling in single-phase materials. | Weiming ZHANG Fu-Zhi DAI Huimin XIANG Biao ZHAO Xiaohui WANG Na NI Rajamallu KARRE Shijiang WU Yanchun ZHOU | 2021 | Journal of Advanced Ceramics2021，10，6： | 4 |
| 8 | 高场动物功能磁共振成像的实验设计、准备、扫描和后处理的浅见显示文摘 | 鲜军舫 王振常 Qian Yin Xiping Liu Chunming Xie Gaohong Wu Shijiang Li | 2008 | 中国医学影像技术2008，24，9： | 3 |
| 9 | Periostin expression is upregulated and associated with myocardial fibrosis in human failing hearts显示文摘 | Sheng Zhao Hengfang Wu Wenlong Xia Xiangjian Chen Shushu Zhu Shijiang Zhang Yongfeng Shao Wenzhu Ma Di Yang Jinan Zhang | 2013 | Journal of Cardiology2013，，： | 1 |
| 10 | Fast Estimation of Loader’s Shovel Load Volume by 3D Reconstruction of Material Piles显示文摘Fast and accurate measurement of the volume of earthmoving materials is of great signifcance for the real-time evaluation of loader operation efciency and the realization of autonomous operation. Existing methods for volume measurement, such as total station-based methods, cannot measure the volume in real time, while the bucket-based method also has the disadvantage of poor universality. In this study, a fast estimation method for a loader’s shovel load volume by 3D reconstruction of material piles is proposed. First, a dense stereo matching method (QORB–MAPM) was proposed by integrating the improved quadtree ORB algorithm (QORB) and the maximum a posteriori probability model (MAPM), which achieves fast matching of feature points and dense 3D reconstruction of material piles. Second, the 3D point cloud model of the material piles before and after shoveling was registered and segmented to obtain the 3D point cloud model of the shoveling area, and the Alpha-shape algorithm of Delaunay triangulation was used to estimate the volume of the 3D point cloud model. Finally, a shovel loading volume measurement experiment was conducted under loose-soil working conditions. The results show that the shovel loading volume estimation method (QORB–MAPM VE) proposed in this study has higher estimation accuracy and less calculation time in volume estimation and bucket fll factor estimation, and it has signifcant theoretical research and engineering application value. | Binyun Wu Shaojie Wang Haojing Lin Shijiang Li Liang Hou | 2023 | Chinese Journal of Mechanical Engineering2023，36，5： | 0 |
| 11 | Theoretical predictions and experimental verification on the phase stability of enthalpy-stabilized HE TMREB_(2)s显示文摘Transition metal diborides(TMB_(2)s)are the materials of choice in extreme environments due to their excellent thermal and chemical stabilities.However,the degradation of oxidation resistance of TMB_(2)s at elevated temperature still hinders their applications.To cope with this challenge,it is effective to incorporate rare earth elements to form high-entropy transition and rare-earth metal diborides(HE TMREBs).To obtain thermodynamically stable single-phase structures for HE TMREB_(2)s,a“16×16 mixed enthalpy matrix”is constructed using first-principles calculations to predict the single-phase formation ability of120 two-component diborides(TCBs).Through the use of the“16×16 mixed enthalpy matrix”of TCBs,specific combinations of TMB_(2)s and REB_(2)s that are most likely to form single-phase HE TMREB_(2)s are confirmed.Subsequently,based on the energy distribution of the local mixing enthalpies of all possible configurations,the enthalpy and entropy descriptors of HE TMREB_(2)s(RE=Sc,Lu,Tm,Er,Ho and Dy)are investigated.It is found that the mixing enthalpy plays a critical role in the stability of the single-phase HE TMREB_(2)s,i.e.,HE TMREB_(2)s are enthalpy-stabilized materials.The experimental results further confirm that enthalpy dominates the thermodynamic domain and drives the stability of REB_(2)s in HE TMREB_(2)s.This study validates that enthalpy-stabilized HE TMREB_(2)s can further expand the compositional space of ultrahigh temperature ceramics(UHTCs)and is expected to further improve the oxidation resistance and high temperature properties of UHTCs. | Ze Zhang Shizhen Zhu Fu-Zhi Dai Huimin Xiang Yanbo Liu Ling Liu Zhuang Ma Shijiang Wu Fei Liu Kuang Sun Yanchun Zhou | 2022 | Journal of Materials Science & Technology2022，，26： | 0 |
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