The Efficacy of High-Intensity Focused Ultrasound (HIFU) in Advanced Pancreatic Cancer

OBJECTIVE To observe the efficacy of high-intensity focused ultrasound (HIFU) in the treatment of late-stage pancreatic cancer. METHODS Sixteen patients with advanced pancreatic cancer received HIFU therapy.Evaluation of efficacy was made on the basis of changes in clinical symptoms and variations in the tumor echo and size. RESULTS Clinical symptoms such as pain were significantly alleviated,echo of the tumor was enhanced with B-US and the quality of life such as eating,sleeping and mental status was markedly improved;no serious complications were observed. CONCLUSION The use of HIFU in the treatment of advanced pancreatic cancer is feasible and safe.It is effective in killing the carcinoma cells and alleviating pain.This technique may offer non-invasive therapy for the treatment of patients with late-stage pancreatic cancer.

基于参数特征偏移的神经网络隐写检测方法

目前,许多深度学习的预训练模型被发布出来用以帮助工程师和研究人员开发基于深度学习的系统或进行研究,从而减少了他们的工作量。过去的工作表明,秘密信息可以被嵌入到神经网络参数中且不影响模型的准确性,恶意开发者可以借此将恶意软件或其他有害信息隐藏到预先训练的模型中。因此,对这些隐写后的预训练模型进行可靠的检测非常重要。我们分析了现有的神经网络隐写方法,发现它们不可避免地会导致参数统计的偏差。针对LSB隐写,实验发现其会造成参数位平面随机性上的偏差;针对COR隐写和SGN隐写,实验发现其会造成参数分布上的偏差。基于这些偏差,我们提出神经网络隐写的隐写分析方法,即从良性和恶性模型中提取特征建立分类器。据我们所知,这是第一个检测神经网络隐写术的工作。实验结果表明,本文提出的检测算法能够可靠地检测出含有嵌入式信息的模型。值得注意的是,我们的检测方法即使在低负载下仍然有效。

Primary renal mucosa-associated lymphoid tissue lymphoma, the result of chronic pyelonephritis?

Objective: To report 2 cases of primary renal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma), and observe the relations between this rare tumor of kidney and chronic pyelonephritis. Methods: 2 renal MALT lymphomas were collected from referral consultation. Detailed clinical information were reviewed, morphological analysis based on the HE section, and immunohistochemistry were performed by CD20, CD79a, CD5, CD10, CD43, CD23, BCL10 and Cyclin D1 antibodies. Results: 2 female patients with age of 48 and 55, respectively, all had a history of chronic pyelonephritis. Under the B ultrasonic and CT scanning a bump in the kidney was found. Renal carcinoma suspected and hereby the whole nephrectomy performed. In the macroscopic, tumors were laid in the renal medulla, with dark red color and ill-defined boundary. In the microscopic, there were mixed lymphoid cells infiltrate which mainly consisted of small lympho- cytes, centrocyte-like cells, lymphoplasmacytoid and plasma cells, reactive follicles and lymphoepithelial lesions also could be seen in the lesion, but follicles colonization was rare. In fact, except changes of lymphoma, basic renal disease also could be seen. Most glomeruli were atrophic, some glomeruli were hyperplastic and hypertrophic. Tubules were dilated or contacted, many dilated tubules contained pink-color glassy-appearing casts that suggest the appearance of thyroid tissue. As a result, those 2 cases showed juxtaposed changes of lymphoma and pyelonephritis. Immunohistochemistry showed that tumor cells were CD20 and CD79a positive, CD43 was weak positive, but CD5, CD10, CD23, BCL10 and Cyclin D1 were all negative. Conclusion: Primary renal MALT lymphoma was very rare disease. According to the clinical manifestation, it’s hard to differentiate from renal cell carcinoma. But the morphological features were consistent with the classic MALT lymphomas in other sites. Immunophenotypic profiles were helpful for diagnosis. Based on the truth that many MALT lymphomas in other sites were connected with chronic inflammations, we suppose that the renal MALT lymphoma may originate from chronic pyelonephritis.

Sunflower-Like SrCo_(2)S_(4)@f-MWCNTs Hybrid Wrapped by Engineering N-Reduced Graphene Oxide for High Performance Dye-Sensitized Solar Cells

A novel sunflower-like nanocomposite of SrCo_(2)S_(4)nanoflakes and functionalized multiwall carbon nanotubes(f-MWCNTs)entanglement enveloped in nitrogen-reduced graphene oxide(N-RGO)is prepared by a cheap process.The unique entanglement structure of the material exhibits higher specific surface area,better electrical conductivity and other properties.This helps to reduce the transfer resistance in the photoelectric process of the battery and improve the electrochemical activity,thus increasing the photoelectric conversion efficiency of the battery.The new ternary cobalt-based sulfide material can replace platinum as the counter electrode(CE)material loaded on dye-sensitized solar cells(DSSCs).DSSCs with SrCo_(2)S_(4)@f-MWCNTs@N-RGO(SCS@f-M@N-R)as CE material show excellent photoelectric conversion efficiency(PCE,8.06%),even surpassing than that of Pt CE material(7.51%).The low cost,excellent electrocatalytic performance and simple preparation method of SCS@f-M@N-R nanomaterial provide feasibility for replacing platinum material as the CE material of DSSCs,which is of great significance and persuasion.

Antifungal Activity of Schinifoline Against Candida Albicans in Caenorhabditis Elegans

Zanthoxylum schinifolium has been used as spices and traditional medicine in China for hundreds of years.A variety of active substances have been isolated from Zanthoxylum schinifolium using biological and chemical techniques.Among these substances,the effect of schinifoline has gradually attracted much attention.Candida albicans is one of the most common pathogens isolated from the gastrointestinal tract,vagina,and mouth in healthy individuals.In a healthy population,there are various mechanisms in host,such as the microbial flora,the epithelial barriers,and the innate immune system,that can control the presence of Candida albicans.However,when host immunity is compromised,an invasive fungal infection is more likely to occur.In this study,we explored the antifungal activity of schinifoline against Candida albicans in Caenorhabditis elegans.To determine the optimal concentration of schinifoline,we investigated the lifespan,defecation cycle and locomotion behavior of Caenorhabditis elegans after treatment with schinifoline.In addition,we examined colony formation in the intestine of Caenorhabditis elegans after Candida albicans infection.The results indicated that 100 and 200 mg/L of schinifoline could prolonged the lifespan,shorten the defecation cycle and increased the locomotion behavior of Caenorhabditis elegans,with 100 mg/L of schinifoline being the optimal concentration.Moreover,100 mg/L of schinifoline increased the lifespan of Caenorhabditis elegans after infection and inhibited the colony formation of Candida albicans in Caenorhabditis elegans intestine.Therefore,we concluded that schinifoline exhibits anti-fungal effects and its potential use as natural drugs should be further explored in future studies.

Clinical Report on Californium-252 Neutron Intraluminal Brachytherapy Combined with External Irradiation for Cervical Carcinoma Treatment

OBJECTIVE To observe the curative effects and complications of californium-252 (252Cf) neutron intraluminal brachytherapy (IBT) combined with external irradiation (El) for treatment of cervical carcinoma. METHODS From December 2000 to December 2004, 128 cases of cervical carcinoma staged intoⅡA-ⅢB according to the International Federation of Gynecology and Obstetrics (FIGO) standards were treated with 2S2Cf neutron IBT using 8-10 Gy per fraction, once a week. The total dose at reference A point was 36-40 Gy in 4-5 fractions. From the second day after 252Cf neutron IBT treatment, the whole pelvic cavity was treated with 60Coγ-ray El, applying 2 Gy per fraction, 4 times per week. After 20-25 Gy of El, the center of the whole pelvic field was blocked with 4 cm of lead in width. The total dose of El was 45-50 Gy. RESULTS The short-term therapeutic effects were CR 95.3% and PR 4.7%. The 3 and 5-year local control rates were 93.5% and 87.9%. The overall 3-year survival rate was 87.5% and for StagesⅡandⅢ, 90.9% and 81.5% respectively; the overall 5-year survival rate was 70% and for StagesⅡandⅢ, 76.2% and 61% respectively. The rate of radiation complications was 4.7% for radiation cystitis, 7.8% for radiation proctitis, 6.3% for vagina contracture and adhesion and 5.5% for protracted radiation proctitis. CONCLUSION An combination of 252Cf neutron IBT with El for treatment of cervical carcinoma can be well -tolerated by cervical carcinoma patients. The rate of local tumor control is high and radiation complications are few.

Coordination-theoretic approach to modelling grid service composition process

A grid service composite process is made up of complex coordinative activities.Developing the appropriate model of grid service coordinative activities is an important foundation for the grid service composition.According to the coordination theory,this paper elaborates the process of the grid service composition by using UML 2.0,and proposes an approach to modelling the grid service composition process based on the coordination theory.This approach helps not only to analyze accurately the task activities and relevant dependencies among task activities,but also to facilitate the adaptability of the grid service orchestration to further realize the connectivity,timeliness,appropriateness and expansibility of the grid service composition.

Instability and Non-reproducibility of Gibbsite Precipitation Process in Alumina Powder Production

Gibbsite (Al2O3 3H2O) powder. used for alumina powder production. can be prepared by the decomposition of sodium alum inate solutions induced by dilution or partial neutral ization, This decomposition process exhibits an incubation period and instability or non-reproducibility in reaction kinetics, UV time-scanning spectra and Raman spectra change have been measured to investigate the solution in incubation period and the factors affecting the grain size of gibbsite precipitate

Deep 3D mesh watermarking with self-adaptive robustness

Robust 3D mesh watermarking is a traditional research topic in computer graphics,which provides an efficient solution to the copyright protection for 3D meshes.Traditionally,researchers need manually design watermarking algorithms to achieve suffcient robustness for the actual application scenarios.In this paper,we propose the first deep learning-based 3D mesh watermarking network,which can provide a more general framework for this problem.In detail,we propose an end-to-end network,consisting of a watermark embedding sub-network,a watermark extracting sub-network and attack layers.We employ the topology-agnostic graph convolutional network(GCN)as the basic convolution operation,therefore our network is not limited by registered meshes(which share a fixed topology).For the specific application scenario,we can integrate the corresponding attack layers to guarantee adaptive robustness against possible attacks.To ensure the visual quality of watermarked 3D meshes,we design the curvature consistency loss function to constrain the local geometry smoothness of watermarked meshes.Experimental results show that the proposed method can achieve more universal robustness while guaranteeing comparable visual quality.

一种统计特征保持的时序数据库水印方案

数据库水印是保护数据库版权最有效的方法之一。然而,传统的数据库水印有一个潜在的缺点:水印的嵌入会改变数据的分布,从而影响数据库的使用和分析。考虑到大多数分析都是基于目标数据库的统计特征,保持统计特征的一致性是确保数据库可分析性的关键。由于统计特征分析往往是分组进行的,与传统的关系数据库相比,时序数据库(TSDBs)具有明显的时间分组特征,更具有分析价值。因此,本文提出了一种鲁棒的时序数据库水印算法,有效地保证了统计特征的一致性。基于TSDBs的时间分组特征,提出了一种基于线性回归、误差补偿和水印验证的三步水印方案RCV。根据线性回归模型和误差补偿的特性,该方案可以生成一组具有相同统计特征的数据。然后,基于验证机制对生成的数据进行验证,直到它可以传递目标的水印消息为止。与现有方法相比,该方法具有更好的鲁棒性和保持统计特征不变的能力。

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

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.

High entropy rare earth hexaborides/tetraborides(HE REB_(6)/HE REB_(4)) composite powders with enhanced electromagnetic wave absorption performance

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.

Past,present,and future of biochar

After entering the twenty-first century,biochar has become a focal point of multidisciplinary research because of its special characteristics,broad application,and promising development prospects.Basic and applied research on the application of biochar in the areas of agriculture,environment,and energy have increased dramatically in the face of food security,environmental pollution,and energy shortage.Although there are some disputes about biochar research,many studies have demonstrated the importance of biochar research from the perspective of scientific advancement and practical application.This paper briefly recalls the history of biochar application;introduces research progress on the basic characteristics of biochar and its associated production technologies;summarizes the research status and existing problems of biochar application in the areas of agriculture,environment,and energy;and analyzes the potential problems and development trends of biochar research in the future.

Achieving ultra-broadband electromagnetic wave absorption in high-entropy transition metal carbides (HE TMCs)

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.

Enabling highly efficient and broadband electromagnetic wave absorption by tuning impedance match in high-entropy transition metal diborides (HETMB_(2))

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.

云与用户之间交互式抗屏摄密文水印协议

现有的云存储服务普遍推出了浏览文件的功能,这为用户通过拍摄屏幕上的文件来窃取信息带来极大的便利,同时也加重了信息泄露的风险.因此,用户通过拍照窃取信息对云存储服务来说是一个潜在的安全性问题.现有的办法是云端在推送图像至用户端前,先嵌入与用户身份相关的抗屏摄水印,那么云端能从拍摄的图像检测到水印,发现用户身份.然而云端和用户端都有含用户水印的图像,我们无法确认被泄露的图像是从云端流出的还是从用户端流出的.为了消除泄露源的二义性,使用密文水印,云端将用户的密文水印嵌入到明文图像,生成含用户水印的密文图像.只有用户端能将之解密,获得相应的明文图像.一旦该图像被偷拍泄露,我们可断定该图像一定是从用户端流出的.但是目前的抗屏摄水印算法不支持上述功能,仅支持明文水印的嵌入.为此,本文提出一个云与用户之间的抗屏摄密文水印协议,旨在保护版权用户对其图像的版权,防止使用图像的用户通过偷拍窃取图像.通过理论分析和仿真实验,本文验证了所提出协议在实施过程中的安全性和有效性.

Development of the straw biochar returning concept in China

Biochar produced from straw has been shown to improve soil physicochemical properties.This review introduces the fundamental concepts,the broad applications,and underlying theory of straw biochar returning.Current developments in biochar industry and the production practices prevalent among enterprises in China are critiques.This review analyzes current knowledge gaps,challenges,and opportunities in the industrial application of straw biochar returning.Biochar standards,the quantitative and qualitative analysis methods for biochar,and high-value-added products that are based on biochar are critically examined with goal of providing recommendations for future studies.We propose production and modification of biochar that is application oriented to enhance its fitness for purpose as well as long-term and large-space-scale field study to better understand its impact on soil properties and ecotoxicology.Finally,we make prospects for the future development of SBR,including constructing a standard system about straw biochar returning and promoting self-discipline of biochar industry and the establishment of a biochar-based agricultural production model.

Enhanced debromination of 4-bromophenol by the UV/sulfite process：Efficiency and mechanism

Halogenated aromatic compounds have attracted increasing concerns due to their toxicity and persistency in the environment, and dehalogenation is one of the promising treatment and detoxification methods. Herein, we systematically studied the debromination efficiency and mechanism of para-bromophenol（4-BP） by a recently developed UV/sulfite process. 4-BP underwent rapid degradation with the kinetics accelerated with the increasing sulfite concentration, pH（6.1–10） and temperature, whereas inhibited by dissolved oxygen and organic solvents. The apparent activation energy was estimated to be 27.8 kJ/mol. The degradation mechanism and pathways of 4-BP were explored by employing N2O and nitrate as the electron scavengers and liquid chromatography/mass spectrometry to identify the intermediates. 4-BP degradation proceeded via at least two pathways including direct photolysis and hydrated electron-induced debromination. The contributions of both pathways were distinguished by quantifying the quantum yields of 4-BP via direct photolysis and hydrated electron production in the system. 4-BP could be readily completely debrominated with all the substituted Br released as Br-, and the degradation pathways were also proposed. This study would shed new light on the efficient dehalogenation of brominated aromatics by using the UV/sulfite process.

利用点缺陷策略提高Zintl相BaAgSb的热电性能

Zintl相化合物由于其独特的"声子玻璃-电子晶体"(PGEC)结构在热电领域具有广泛的应用前景.本文报道了Zintl相热电材料BaAgSb的热电性质.通过引入Ba空位,可以提高p型BaAgSb的载流子浓度,抑制其本征激发,Ba_(0.98)AgSb的ZT值在773 K达到了~0.56.此外,在Ba位进一步合金化Eu,不仅能够引入点缺陷散射降低晶格热导率,而且由于载流子迁移率的提高使其电输运性质也得到了改善.最终,Ba_(0.78)Eu_(0.2)AgSb的ZT值在773 K达到~0.73.

Large electric field-induced strain in the novel BNKTAN-BNBLTZ lead-free ceramics

(1-x)Bi0.5(Na0.82K0.18)0.5Ti0.96(Al0.5Nb0.5)0.04O3-xBi0.46Na0.46Ba0.5La0.02Ti0.97Zr0.03O3 lead-free ceramics(abbreviated as BNKTAN-100x BNBLTZ)was prepared by the conventional solid reaction.XRD patterns and EDS spectrums revealed that a stable solid solution had been formed between BNBLTZ and BNKTAN.With the introduction of BNBLTZ anti-ferroelectric content,BNKTAN relaxor ferroelectrics exhibited the excellent field-induced-strain for x=0.04 corresponding to electric field-induced strain S^0.505%and normal strain d33*~777 pm/V at 65 kV/cm.The large strain response was attributed to the emergence of PNRs in the relaxation process.Additionally,an excellent fatigue resistance performance was obtained within 105cycles(S=0.505%–0.495%and d33*=777–758 pm/V,65 kV/cm).It suggested that prepared ceramics had the great potential to strain sensor and actuators.