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1Health risk assessment of heavy metals in soils and vegetables from wastewater irrigated area,Beijing-Tianjin city cluster,China显示文摘The possible health risks of heavy metals contamination to local population through food chain were evaluated in Beijing and Tianjin city cluster,China,where have a long history of sewage irrigation.The transfer factors(TF) for heavy metals from soil to vegetables for six elements including Cu,Zn,Pb,Cr,As and Cd were calculated and the pollution load indexes(PLI) were also assessed.Results indicate that only Cd exceeded the maximum acceptable limit in these sites.So far,the heavy metal concentrations in soils and vegetables were all below the permissible limits set by the Ministry of Environmental Protection of China and World Health Organization.The transfer factors of six heavy metals showed the trend as Cd > Zn > Cu > Pb > As > Cr,which were dependent on the vegetable species.The estimated dietary intakes of Cu,Zn,Pb,Cr,As and Cd were far below the tolerable limits and the target hazard quotient(THQ) values were less than 1,which suggested that the health risks of heavy metals exposure through consuming vegetables were generally assumed to be safe.Yanchun Wang Min Qiao Yunxia Liu Yongguan Zhu 2012Journal of Environmental Sciences2012,24,4:52
2High entropy defective fluorite structured rare-earth niobates and tantalates for thermal barrier applications显示文摘Rare-earth tantalates and niobates(REjTaO7 and REjNbO7)have been considered as promising candidate thermal barrier coating(TBC)materials in next generation gas-turbine engines due to their ultra-low thermal conductivity and better thermal stability than yttria-stabilized zirconia(YSZ).However,the low Vickers hardness and toughness are the main shortcomings of RE;TaO-and REjNbOr that limit their applications as TBC materials.To increase the hardness,high entropy(Yu3Ybu3Er/3)sTaOr,(Y13YbnErns)NbO,and(Sm1/6Eu1/6Y 1/6Yb1/6Lu1/6Er1/6)3(Nb1/2Ta1/2)O7 are designed and synthesized in this study.These high entropy ceramics exhibit high Vickers hardness(10.912.0 GPa),close thermal expansion coefficients to that of single-principal-component RE3TaO,and RE;NbO,(7.9×10^-6-10.8×10-6 C-1 at room temperature),good phase stability,and good chemical compatibility with thermally grown Al2O3,which make them promising for applications as candidate TBC materials.Zifan ZHAO Heng CHEN Huimin XIANG Fu-Zhi DAI Xiaohui WANG Wei XU Kuang SUN Zhjjian PENG Yanchun ZHOU 2020Journal of Advanced Ceramics2020,9,3:27
3High-entropy ceramics:Present status,challenges,and a look forward显示文摘High-entropy ceramics (HECs) are solid solutions of inorganic compounds with one or more Wyckoff sites shared by equal or near-equal atomic ratios of multi-principal elements.Although in the infant stage,the emerging of this new family of materials has brought new opportunities for material design and property tailoring.Distinct from metals,the diversity in crystal structure and electronic structure of ceramics provides huge space for properties tuning through band structure engineering and phonon engineering.Aside from strengthening,hardening,and low thermal conductivity that have already been found in high-entropy alloys,new properties like colossal dielectric constant,super ionic conductivity,severe anisotropic thermal expansion coefficient,strong electromagnetic wave absorption,etc.,have been discovered in HECs.As a response to the rapid development in this nascent field,this article gives a comprehensive review on the structure features,theoretical methods for stability and property prediction,processing routes,novel properties,and prospective applications of HECs.The challenges on processing,characterization,and property predictions are also emphasized.Finally,future directions for new material exploration,novel processing,fundamental understanding,in-depth characterization,and database assessments are given.Huimin XIANG Yan XING Fu-zhi DAI Hongjie WANG Lei SU Lei MIAO Guojun ZHANG Yiguang WANG Xiwei QI Lei YAO Hailong WANG Biao ZHAO Jianqiang LI Yanchun ZHOU 2021Journal of Advanced Ceramics2021,10,3:28
4Whole-genome sequencing of 508 patients identifies key molecular features associated with poor prognosis in esophageal squamous cell carcinoma显示文摘Esophageal squamous cell carcinoma(ESCC)is a poor-prognosis cancer type with limited understanding of its molecular etiology.Using 508 ESCC genomes,we identified five novel significantly mutated genes and uncovered mutational signature clusters associated with metastasis and patients’outcomes.Several functional assays implicated that NFE2L2 may act as a tumor suppressor in ESCC and that mutations in NFE2L2 probably impaired its tumor-suppressive function,or even conferred oncogenic activities.Additionally,we found that the NFE2L2 mutations were significantly associated with worse prognosis of ESCC.We also identified potential noncoding driver mutations including hotspot mutations in the promoter region of SLC35E2 that were correlated with worse survival.Approximately 5.9%and 15.2%of patients had high tumor mutation burden or actionable mutations,respectively,and may benefit from immunotherapy or targeted therapies.We found clinically relevant coding and noncoding genomic alterations and revealed three major subtypes that robustly predicted patients’outcomes.Collectively,we report the largest dataset of genomic profiling of ESCC useful for developing ESCC-specific biomarkers for diagnosis and treatment.Yongping Cui Hongyan Chen Ruibin Xi Heyang Cui Yahui Zhao Enwei Xu Ting Yan Xiaomei Lu Furong Huang Pengzhou Kong Yang Li Xiaolin Zhu Jiawei Wang Wenjie Zhu Jie Wang Yanchun Ma Yong Zhou Shiping Guo Ling Zhang Yiqian Liu Bin Wang Yanfeng Xi Ruifang Sun Xiao Yu Yuanfang Zhai Fang Wang Jian Yang Bin Yang Caixia Cheng Jing Liu Bin Song Hongyi Li Yi Wang Yingchun Zhang Xiaolong Cheng Qimin Zhan Yanhong Li Zhihua Liu-Show 2020Cell Research2020,30,10:19
5(La0.2Ce0.2Nd0.2Sm0.2Eu0.2)PO4: A high-entropy rare-earth phosphate monazite ceramic with low thermal conductivity and good compatibility with Al2O3显示文摘Low thermal conductivity, matched thermal expansion coefficient and good compatibility are general requirements for the environmental/thermal barrier coatings(EBCs/TBCs) and interphases for Al2O3 f/Al2O3 composites. In this work, a novel high-entropy(HE) rare-earth phosphate monazite ceramic (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)PO4 is designed and successfully synthesized. This new type of HE rare-earth phosphate monazite exhibits good chemical compatibility with Al2O3, without reaction with Al2O3 as high as 1600℃ in air. Moreover, the thermal expansion coefficient(TEC) of HE (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)PO4(8.9 × 10^-6/℃ at 300–1000℃) is close to that of Al2O3. The thermal conductivity of HE (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)PO4 at room temperature is as low as 2.08 W·m^-1·K^-1, which is about 42% lower than that of La PO4. Good chemical compatibility, close TEC to that of Al2O3, and low thermal conductivity indicate that HE (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)PO4 is suitable as a candidate EBC/TBC material and an interphase for Al2O3 f/Al2O3 composites.Zifan Zhao Heng Chen Huimin Xiang Fu-Zhi Dai Xiaohui Wang Zhijian Peng Yanchun Zhou 2019Journal of Materials Science & Technology2019,35,12:15
6High-entropy(Nd_(0.2)Sm_(0.2)Eu_(0.2)Y_(0.2)Yb_(0.2))_(4)Al_(2)O_(9) with good high temperature stability,low thermal conductivity,and anisotropic thermal expansivity显示文摘The critical requirements for the environmental barrier coating(EBC)materials of silicon-based ceramic matrix composites(CMCs)include good tolerance to harsh environments,thermal expansion matches with the interlayer mullite,good high-temperature phase stability,and low thermal conductivity.Cuspidine-structured rare-earth aluminates RE_(4)Al_(2)O_(9) have been considered as candidates of EBCs for their superior mechanical and thermal properties,but the phase transition at high temperatures is a notable drawback of these materials.To suppress the phase transition and improve the phase stability,a novel cuspidine-structured rare-earth aluminate solid solution(Nd_(0.2)Sm_(0.2)Eu_(0.2)Y_(0.2)Yb_(0.2))_(4)Al_(2)O_(9) was designed and successfully synthesized inspired by entropy stabilization effect of high-entropy ceramics(HECs).The as-synthesized HE(Nd_(0.2)Sm_(0.2)Eu_(0.2)Y_(0.2)Yb_(0.2))_(4)Al_(2)O_(9) exhibits a close thermal expansion coefficient(6.96×10^(-6) K^(-1) at 300-1473 K)to that of mullite,good phase stability from 300 to 1473 K,and low thermal conductivity(1.50 W·m^(-1)·K^(-1) at room temperature).In addition,strong anisotropic thermal expansion has been observed compared to Y_(4)Al_(2)O_(9) and Yb_(4)Al_(2)O_(9).The mechanism for low thermal conductivity is attributed to the lattice distortion and mass difference of the constituent atoms,and the anisotropic thermal expansion is due to the anisotropic chemical bonding enhanced by the large size rare-earth cations.Zifan ZHAO Huimin XIANG Heng CHEN Fu-Zhi DAI Xiaohui WANG Zhijian PENG Yanchun ZHOU 2020Journal of Advanced Ceramics2020,9,5:12
7Preparation and properties of CMAS resistant bixbyite structured high-entropy oxides RE_(2)O_(3)(RE=Sm,Eu,Er,Lu,Y,and Yb):Promising environmental barrier coating materials for Al_(2)O_(3)f/Al_(2)O_(3) composites显示文摘Y_(2)O_(3) is regarded as one of the potential environmental barrier coating(EBC)materials for Al_(2)O_(3)f/Al_(2)O_(3)ceramic matrix composites owing to its high melting point and close thermal expansion coefficient to Al_(2)O_(3).However,the relatively high thermal conductivity and unsatisfactory calcium-magnesium-aluminosilicate(CMAS)resistance are the main obstacles for the practical application of Y_(2)O_(3).In order to reduce the thermal conductivity and increase the CMAS resistance,four cubic bixbyite structured high-entropy oxides RE_(2)O_(3),including(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3),(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3),(Sm_(0.2)Eu_(0.2)Er_(0.2)Y_(0.2)Yb_(0.2))2O_(3),and(Sm_(0.2)Eu_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)were designed and synthesized,among which(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)and(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)bulks were prepared by spark plasma sintering(SPS)to investigate their mechanical and thermal properties as well as CMAS resistance.The mechanical properties of(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3)and(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3) are close to those of Y_(2)O_(3) but become more brittle than Y_(2)O_(3).The thermal conductivities of(Eu_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb_(0.2))2O_(3) and(Sm_(0.2)Er_(0.2)Lu_(0.2)Y_(0.2)Yb02)2O_(3)(5.1 and 4.6 W·m^(-1)·K^(-1))are only 23.8%and 21.5%respectively of that of Y_(2)O_(3)(21.4 W·m^(-1)·K^(-1)),while their thermal expansion coefficients are close to those of Y_(2)O_(3) and A12O_(3).Most importantly,HE RE_(2)O_(3) ceramics exhibit good CMAS resistance.After being attacked by CMAS at 1350℃for 4 h,the HE RE_(2)O_(3) ceramics maintain their original morphologies without forming pores or cracks,making them promising as EBC materials for Al_(2)O_(3)f/Al_(2)O_(3) composites.Yanan SUN Huimin XIANG Fu-Zhi DAI Xiaohui WANG Yan XING Xiaojun ZHAO Yanchun ZHOU 2021Journal of Advanced Ceramics2021,10,3:10
8New Technique of Casting-rolling Strips for Semi-solid Magnesium Alloys显示文摘The conjugation of semi-solid process technique and casting-rolling technique applied to produce the magnesium stripswas studied. The semi-solid slurry has been prepared continuously by the mechanical method and its temperaturewas controlled strictly at the same time. AZ91D and AZ31 casting magnesium alloys were applied to the experiment.The casting-rolling strips with non-dendritic structure were obtained and its main mechanical property is better. Theprocess ability of the casting-rolling strips was studied. It is significative to link the semi-solid process techniques andcasting-rolling techniques, through which we can get high quality magnesium alloy strips with non-dendritic structureand improve the overall properties of the products.Shuisheng XIE Maopeng GENG Xinmin ZHOU Ying ZHANG Songyang ZHANG Yanchun WANG Guojie HUANG 2005Journal of Materials Science & Technology2005,21,6:9
9High-entropy(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3:A promising thermal/environmental barrier material for oxide/oxide composites显示文摘Yttrium aluminum perovskite(YAl O3)is a promising candidate material for environmental barrier coatings(EBCs)to protect Al2 O3 f/Al2 O3 ceramic matrix composites(CMCs)from the corrosion of high-temperature water vapor in combustion environments.Nevertheless,the relatively high thermal conductivity is a notable drawback of YAl O3 for environmental barrier coating application.Herein,in order to make REAl O3 more thermal insulating,a novel high-entropy rare-earth aluminate ceramic(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3 was designed and synthesized.The as-prepared(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3 ceramic possesses close thermal expansion coefficient(9.02×10-6/oC measured from room temperature to 1200℃)to that of Al2 O3.The thermal conductivity of(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3 at room temperature is 4.1 W·m-1K-1,which is almost one third of the value of YAl O3.Furthermore,to effectively prevent the penetration of water vapor from possible pores/cracks of coating layer,which are often observed in T/EBCs,a tri-layer EBC system REAl O3/RE3 Al5 O12/(Al2 O3 f/Al2 O3 CMCs)is designed.Close thermal expansion coefficient to Al2 O3 and low thermal conductivity of(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3,as well as the formation of dense garnet layer at(Y0.2Nd0.2Sm0.2Eu0.2Er0.2)AlO3/Al2 O3 interface,indicate that this new type of high-entropy ceramic is suitable as a candidate environmental barrier coating material for Al2 O3 f/Al2 O3 CMCs.Zifan Zhao Heng Chen Huimin Xiang Fu-Zhi Dai Xiaohui Wang Wei Xu Kuang Sun Zhijian Peng Yanchun Zhou 2020Journal of Materials Science & Technology2020,47,12:9
10Microstructure and mechanical properties of Mg-4.0Zn alloy reinforced by NiO-coated CNTs显示文摘Mg-4.0Zn alloy composite reinforced by NiO-coated CNTs(NiO@CNTs) was synthesized by combining ball-milling and a casting process. The yield strength(YS) and elongation to failure of the composite were dramatically increased by 44.9% and 38.6%, respectively, compared to its alloy counterpart. The significantly enhanced mechanical properties of the as-synthesized composite are mainly ascribed to an improved interfacial bond, grain refinement and good dispersion of CNTs in the matrix via. coating NiO on CNTs.It is shown that the NiO-nanolayer on the CNTs significantly enhances the interfacial bonding strength and effectively prevents the agglomeration of CNTs. NiO@CNTs are, therefore, expected to be a highly sustainable and dispersible reinforcement for magnesium matrix composites with superior performance.Qiuhong Yuan Xiaoshu Zeng Yanchun Wang Lan Luo Yan Ding Dejiang Li Yong Liu 2017Journal of Materials Science & Technology2017,33,5:8
11Comprehensive reform of community health service in east,middle and west regions of China:from patients’perspective显示文摘Objectives:To analyze the satisfaction of patients with community health service(CHS)and the changes of the CHS delivered before and after the new health reform in different regions of China,and to put forward relevant policy recommendations for CHS development.Methods:Twelve community health centers were selected by random sampling in each of the eight typical cities in the east,middle and west regions of China.Questionnaire survey was conducted among patients visiting these institutions during daily work hours.Results:The proportions of the participants who stated that the medical environment,service attitude and medical skills of the doctors were improved were higher in the west region than those of the east and middle regions;but the percentage of patients who held that the drug price had lowered was higher in the east region than those of the middle and west region,the differences were of statistical significance(P<0.0125).The patients’satisfaction rates with medical environment,service attitude,and technical skills of the medical staff in the west region were 88.9%,91.5%and 81.6%respectively,which were higher than those in the east and middle regions.In the east region,the satisfaction rate with the reimbursement for this visit was 58.5%,which was highest among the three regions;in the west region,patients’satisfaction rates with drug types and preventive care were 51.5%and 65.9%,respectively,which was significantly higher than those in the east and middle regions(P<0.0125).As recommended by the participants,the top three aspects of health services that need to be improved were drug type and quality(25.3%),drug prices(21.8%)and technical skills(18.2%)in the east region;infrastructure(28.2%),drug prices(21.8%)and drug types and quality(21.2%)in the middle region;infrastructure(30.8%),drug types and quality(28.1%)and reimbursement(27.9%)in the west region.Conclusions:The comprehensive CHS reform should take the opinions of patients into account;essential drug system should be consolidated continually;and the reform of the payment system should be promoted by actively cooperating with the health insurance organizations.JIANGMEI QIN YANCHUN ZHANG LIFANG ZHANG LIQUN LIU WEI ZHOU CAILING LIU LIKUN WANG JING LI 2013Family Medicine and Community Health2013,1,2:6
12Aerobic Oxidation of Benzyl Alcohol Catalyzed by Cu-Mn Mixed Oxides and 2,2,6,6-Tetramethyl-piperidyl-1-oxyl显示文摘异构的 Cu-Mn 混合了氧化物能调停由在中立状况下面的分子的氧的本甲基酒精的催化速度的选择氧化,并且是 recyclable。在超过 1 的 Cu 和 Mn 的摩尔比率的情况中,在 Cu-Mn 内的高度分散的 CuO 混合了氧化物为在催化氧化的好表演负责。给词调音:Cu-Mn 氧化物;2,2,6,6-tetramethyl-piperidyl-l-oxyl;氧气的氧化;Yanchun Guo Junfeng Zhao Jinxia Xu Wei Wang Fengshou Tian Guanyu Yang Maoping Song 2007Journal of Natural Gas Chemistry2007,16,2:6
13The application of perovskite materials in solar water splitting显示文摘Solar water splitting is a promising strategy for sustainable production of renewable hydrogen,and solving the crisis of energy and environment in the world.However,large-scale application of this method is hampered by the efficiency and the expense of the solar water splitting systems.Searching for non-toxic,low-cost,efficient and stable photocatalysts is an important way for solar water splitting.Due to the simplicity of structure and the flexibility of composition,perovskite based photocatalysts have recently attracted widespread attention for application in solar water splitting.In this review,the recent developments of perovskite based photocatalysts for water splitting are summarized.An introduction including the structures and properties of perovskite materials,and the fundamentals of solar water splitting is first provided.Then,it specifically focuses on the strategies for designing and modulating perovskite materials to improve their photocatalytic performance for solar water splitting.The current challenges and perspectives of perovskite materials in solar water splitting are also reviewed.The aim of this review is to summarize recent findings and developments of perovskite based photocatalysts and provide some useful guidance for the future research on the design and development of highly efficient perovskite based photocatalysts and the relevant systems for water splitting.Yanbin Huang Jun Liu Yanchun Deng Yuanyuan Qian Xiaohao Jia Mengmeng Ma Cheng Yang Kong Liu Zhijie Wang Shengchun Qu Zhanguo Wang 2020Journal of Semiconductors2020,41,1:6
14A joint high-resolution processing method and its application for thin inter-beds显示文摘Seismic processing characterizing thickness and borders of thin inter-beds has gradually evolved from post-stack migration to pre-stack migration,and the latter considers both vertical and lateral resolutions.As the key processing methods for improving vertical and lateral resolution,conventional deconvolution and pre-stack time migration(PSTM) are not simply dominated by the estimation and compression of the wavelet because of its instability.Therefore,considering the variations of wavelet frequency before,during and after PSTM can obtain good common reflection point(CRP) gathers and imaging profiles of thin inter-beds.Based on the frequency characteristics of the wavelet before,during and after PSTM,a joint high-resolution processing method for thin inter-beds is proposed in this paper,including inverse Q filtering for high-frequency compensation before PSTM,optimum weighting Kirchhoff PSTM for preserving high-frequencies during PSTM,and wavelet harmonizer deconvolution for consistent processing and frequency-band broadening after PSTM.An application to real data characterized by mudstone beds in the Oriente Basin proved that the joint high-resolution processing method is effective for determining the thickness and borders of thin inter-beds and is favorable for subsequent reservoir prediction and seismic inversions.Liu Zhiwei Wang Yanchun 2013Petroleum Science2013,10,2:6
15Electroacupuncture-regulated neurotrophic factor mRNA expression in the substantia nigra of Parkinson's disease rats显示文摘Acupuncture for the treatment of Parkinson's disease has a precise clinical outcome.This study investigated the effect of electroacupuncture at Fengfu (GV16) and Taichong (LR3) acupoints in rat models of Parkinson's disease induced by subcutaneous injection of rotenone into rat neck and back.Reverse transcription-PCR demonstrated that brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor mRNA expression was significantly increased in the substantia nigra of rat models of Parkinson's disease,and that abnormal behavior of rats was significantly improved following electroacupuncture treatment.These results indicated that electroacupuncture treatment upregulated brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor mRNA expression in the substantia nigra of rat models of Parkinson's disease.Thus,electroacupuncture may be useful in the treatment of Parkinson's disease.Shuju Wang Jianqiao Fang Jun Ma Yanchun Wang Shaorong Liang Dan Zhou Guojie Sun 2013Neural Regeneration Research2013,8,6:4
16Correlation between Expression of P38 MAPK-Signaling and uPA in Breast Cancer显示文摘OBJECTIVE To study the expression of phosphorylated p38 mitogen-activated protein kinase(p-p38)and uPA and the correlation of their expression with breast cancer clinicopathological characteristics,and to investigate the role of the p38MAPK-signaling pathway in regulating uPA expression in breast cancer cells. METHODS Immunohistochemistry(S-P) was used to test the expression of p-p38 and uPA in 60 specimens of breast cancer tissues.Western blots were adopted to detect expression of the p-p38 and uPA proteins in MDA-MB-231 and MCF-7 breast cancer cells,and uPA expression a er treatment with SB203580,a specific inhibitor of p38 MAPK. RESULTS The positive rate of the p-p38 protein and uPA protein expression in the breast cancer tissues was 56.7% and 60.0%,respectively.The expression of p-p38 was positively related to the expression of uPA(r=0.316,P<0.05).The expression of p-p38 and uPA was related to lymph node metastas is and the TNM stage(P<0.05),but it was not related to the patient’s age or tumor size(P>0.05).The expression of p-p38 and uPA in MDA-MB-231 cells was higher than that in MCF-7 cells.SB203580 inhibited the p38 MAPK pathway and reduced uPA protein expression. CONCLUSION The p38 MAPK-signaling pathway promotes breast cancer malignant progression by up-regulating uPA expression,and it may be an important process in breast cancer invasion and metastasis.Yanchun Han Luying Liu Dongxia Yan Guihua Wang 2008Chinese Journal of Clinical Oncology2008,5,3:4
17To inhibit coffee ring effect in inkjet printing of light-emitting polymer films by decreasing capillary force显示文摘Polymer thin film with uniform thickness and flat surface profile is the key point for polymer light emitting diodes(PLEDs) by inkjet printing. However, the coffee ring effect is usually observed due to the mismatch between the evaporation of the solvent and the decrease of solution volume, which promotes the formation of radial flow from the interior of the drop to the edge. In this paper, coffee ring effects of inkjet printed poly(spirobifluorene) films were proposed to be restrained by decreasing capillary force by adding co-solvent with high boiling point and high viscosity to the main solvent. The low evaporation rate of the co-solvent can reduce the driving force of the radial flow; meanwhile the high viscosity of the co-solvent can increase the resistance of the radial flow. Thus, polymer films with improve uniformity can be obtained due to the suppression of the radial flow. The device performance was greatly improved under the condition of proper film thickness and film uniformity and the maximum luminous efficiency of devices with inkjet printed poly(spirobifluorene) can reach 80% of the spin-coated devices.Xinhong Yu Rubo Xing Zhongxiang Peng Yangming Lin Zhonghui Du Junqiao Ding Lixiang Wang Yanchun Han 2019Chinese Chemical Letters2019,30,1:4
18Enabling 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 2021Journal of Advanced Ceramics2021,10,6:4
19A Deep Reinforcement Learning Algorithm for the Power Order Optimization Allocation of AGC in Interconnected Power Grids显示文摘The integration of distributed generations(solar power,wind power),energy storage devices,and electric vehicles,causes unpredictable disturbances in power grids.It has become a top priority to coordinate the distributed generations,loads,and energy storages in order to better facilitate the utilization of new energy.Therefore,a novel algorithm based on deep reinforcement learning,namely the deep PDWoLF-PHC(policy dynamics based win or learn fast-policy hill climbing)network(DPDPN),is proposed to allocate power order among the various generators.The proposed algorithm combines the decision mechanism of reinforcement learning with the prediction mechanism of a deep neural network to obtain the optimal coordinated control for the source-grid-load.Consequently it solves the problem brought by stochastic disturbances and improves the utilization rate of new energy.Simulations are conducted with the case of the improved IEEE two-area and a case in the Guangdong power grid.Results show that the adaptability and control performance of the power system are improved using the proposed algorithm as compared with using other existing strategies.Lei Xi Lipeng Zhou Lang Liu Dongliang Duan Yanchun Xu Liuqing Yang Shouxiang Wang 2020CSEE Journal of Power and Energy Systems2020,6,3:4
20Enhanced mechanical properties of AZ31 magnesium alloy sheets by continuous bending process after V-bending显示文摘The effects of V-bending process, continuous bending process and combination process on the microstructure and mechanical properties and formability of an AZ31 magnesium alloy sheet were investigated. The experimental results showed that no twins were found in the microstructure of all samples after processes due to the fine grain. The V-bending and continuous bending processes were proved to be an effective approach to modify the mechanical properties and formability. While the samples after the combination process exhibited better mechanical properties and formability than the single processed sample. The yield strength significantly decreased with the value of 100 MPa and the fracture elongation enhanced to 18.3% at room temperature. The Erichsen value was 5.0 mm which was significantly increased by 117% compared with as-received sample. The superior formability of combination processed samples was mainly attributed to the smaller r-value and n-value.Tingzhuang Han Guangsheng Huang Yougen Wang Guangang Wang Yanchun Zhao Fusheng Pan 2016Progress in Natural Science:Materials International2016,26,1:4
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