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| 1 | Effect of circumferential strain rate on dynamic recrystallization and texture of Mg-13Gd-4Y-2Zn-0.5Zr alloy during rotary backward extrusion显示文摘Gleeble-3500 thermal simulator was applied to realize the rotary backward extrusion forming of Mg-13Gd-4Y-2Zn-0.5Zr(wt%)alloy at different circumferential strain rate from 0.009 s^(-1)to 0.027 s^(-1)at 400℃and the dynamic recrystallization mechanism and texture evolution were studied.The results show that the grain size of the alloy was obviously refined after rotary backward extrusion.As the circumferenlial strain rate increased,the dynamic recrystallization fraction gradually increased causing the grain size decreased and the distribution of microstructure became more uniform.At the same time,the texture of{0001},{10-10},{11-20}was weakened and the grain orientation distribution became more random.With the increase of circumferential strain rate,the discontinuous dynamic recrystallization mechanism became dominant,which promoted the weakening of texture and grain refinement of the alloy. | Yingze Meng Jianmin Yu Guanshi Zhang Yaojin Wu Zhimin Zhang Zheng Shi | 2020 | Journal of Magnesium and Alloys2020，8，4： | 7 |
| 2 | Wideband tunable passively Q-switched fiber laser at 2.8 μm using a broadband carbon nanotube saturable absorber显示文摘We propose and demonstrate a widely tunable passively Q-switched Ho^(3+)∕Pr^(3+)-codoped ZrF_4-BaF_2-LaF_3-AlF_3-NaF fiber laser operating in the 2.8 μm mid-infrared(MIR) waveband based on a single-walled carbon nanotube(SWCNT) saturable absorber(SA). The SWCNTs have diameters ranging from 1.4 to 1.7 nm. The modulation depth and saturation intensity of the SWCNT SA measured at 2850 nm are 16.5% and 1.66 MW∕cm^2, respectively. Stable Q-switched pulses with the shortest pulse duration of 1.46 μs and the maximum pulse energy of 0.43 μJ are achieved at a launched pump power of 445.6 mW. The combined use of a broadband SWCNT SA and a plane ruled grating ensures a broad continuously tuning range of 55.0 nm from 2837.6 to 2892.6 nm.The output powers, emission spectra, repetition rates, and pulse durations at different tuning wavelengths are also characterized and analyzed. Our results indicate that SWCNTs can be excellent broadband SAs in the 3 μm MIR region. To the author's knowledge, this is the first demonstration of a widely tunable carbon-nanotubeenabled passively Q-switched fiber laser operating in the 2.8 μm MIR waveband. | YANJIA Lü CHEN WEI HAN ZHANG ZHE KANG GUANSHI QIN YONG LIU | 2019 | Photonics Research2019，7，1： | 5 |
| 3 | Kinetics model for leaching of ion-adsorption type rare earth ores显示文摘This paper aims to establish a mathematical model that can analyze the whole leaching kinetics process of ion-adsorption type rare earth ores.This leaching process is composed of three steps:(1)ammonium ions arrive at the ore particle surface through the diffusion layer;(2)ammonium ions exchange with rare earth ions;and(3)rare earth ions enter into the external solution through the diffusion layer.In the leaching process,it is hypothesized that the ore particle size remains constant The process of ammonium ions and rare earth ions passing through the diffusion layer was described by the Fick law,and the reversible ion exchange process between ammonium ions and rare earth ions was described by the Kerr model,A leaching kinetics model of rare earth ions by ammonium ions was constructed.Accuracy of this kinetics model was verified with laboratory tests.It is found that the correlation coefficients of all data are greater than 0.9000.The proposed kinetics model is therefore feasible for kinetics analysis throughout the leaching process. | Ping Long Guanshi Wang Chao Zhang Yaojie Yang Xiaojing Cao Zibo Shi | 2020 | Journal of Rare Earths2020，38，12： | 5 |
| 4 | Ultraflat, broadband, and highly coherent supercontinuum generation in all-solid microstructured optical fibers with all-normal dispersion显示文摘High flatness, wide bandwidth, and high-coherence properties of supercontinuum(SC) generation in fibers are crucial in many applications. It is challenging to achieve SC spectra in a combination of the properties, since special dispersion profiles are required, especially when pump pulses with duration over 100 fs are employed. We propose an all-solid microstructured fiber composed only of hexagonal glass elements. The optimized fiber possesses an ultraflat all-normal dispersion profile, covering a wide wavelength interval of approximately 1.55 μm. An SC spectrum spanning from approximately 1030 to 2030 nm(corresponding to nearly one octave) with flatness<3 dB is numerically generated in the fiber with 200 fs pump pulses at 1.55 μm. The results indicate that the broadband ultraflat SC sources can be all-fiber and miniaturized due to commercially achievable 200-fs fiber lasers. Moreover, the SC pulses feature high coherence and a single pulse in the time domain, which can be compressed to 13.9-fs pulses with high quality even for simple linear chirp compensation. The Fourier-limited pulse duration of the spectrum is 3.19 fs, corresponding to only 0.62 optical cycles. | CHUNLEI HUANG MEISONG LIAO WANJUN BI XIA LI LILI HU LONG ZHANG LONGFEI WANG GUANSHI QIN TIANFENG XUE DANPING CHEN WEIQING GAO | 2018 | Photonics Research2018，6，6： | 4 |
| 5 | A two-parameter model for ion exchange process of ion-adsorption type rare earth ores显示文摘The establishment of a mathematical model for the ion exchange process is key to creating a theoretical basis for the mining of ion-adsorption type rare earth ores.Ore samples from Xinfeng,Xunwu and Anyuan were used as the test ore samples in the present study and equilibrium batch tests of ore sample leaching using various ammonium sulfate concentrations were performed.The results show that,after leaching,there is a negative exponential relationship between the ratio of the solid-phase rare earth ion concentration to the aqueous-phase rare earth ion concentration and the initial ammonium ion concentration.However,there is a linear relationship between the natural logarithm of the ratio of the solidphase ammonium ion concentration to the aqueous-phase ammonium ion concentration and the initial ammonium ion concentration.Based on the above two functional relationships,a two-parameter model for the equilibrium ion exchange process of ion-adsorption type rare earth ores was established.Using the established model to analyze the test data the model error for the Xunwu ore sample is found to be less than 5%.The proposed model is more accurate compared with the Kerr model.The two-parameter model proposed in this study provides theoretical support for the numerical simulation of column leaching(in-situ leaching)of ion-adsorption type rare earth ores. | Ping Long Guanshi Wang Chao Zhang Ying Huang Sihai Luo | 2020 | Journal of Rare Earths2020，38，11： | 4 |
| 6 | Microstructure evolution,texture and mechanical properties of a Mg-Gd-Y-Zn-Zr alloy fabricated by cyclic expansion extrusion with an asymmetrical extrusion cavity:The influence of passes and processing route显示文摘In the present work,two processing routes(A and B)with 3 CEE-AEC passes are performed on Mg-13 Gd-4 Y-2 Zn-0.4 Zr alloys,and the resultant microstructure evolution,texture analysis and mechanical properties are investigated systematically.The core difference between the two processing routes is the orientation between the expansion and extrusion steps,i.e.,they are parallel to each other for on route A and perpendicular to each other for route B.The results show that a remarkable grain refinement is achieved via both processing routes due to dynamic recrystallization(DRX).Fine equiaxed grains are observed in the samples processed with route B with a final size of 3.6±0.4μm compared to the grain size of 4.5±0.5μm with route A.With an increasing number of CEE-AEC passes,the overall texture intensity decreases,and the basal texture gradually changes to the mixed texture components.The shear deformation introduced by the asymmetrical extrusion cavity promotes a broad angular distribution of the basal planes on routes A and B,leading to an obvious increase in the Schmid factor for the activation of the basal a slip system.The tensile test at ambient temperature reveals that the comprehensive mechanical properties are improved,and the conventional mechanical anisotropy of as-received alloys is alleviated by successive CEE-AEC processing,which is mainly derived from the competitive balance relation between the grain refinement and texture modification. | Zhaoming Yan Xubin Li Jie Zheng Zhimin Zhang Qiang Wang Kaihua Xu Hongzhi Fan Guanshi Zhang Jiaxuan Zhu Yong Xue | 2021 | Journal of Magnesium and Alloys2021，9，3： | 2 |
| 7 | Occurrence of retained placenta is preceded by an inflammatory state and alterations of energy metabolism in transition dairy cows显示文摘Background: Failure to expel fetal membranes within 24 h of calving is a pathological condition defined as retained placenta(RP). The objective of this investigation was to evaluate whether there are alterations in several selected serum variables related to innate immunity and carbohydrate and lipid metabolism that precede occurrence of RP in transition Holstein dairy cows.Methods: One hundred multiparous Holstein dairy cows were involved in the study. Blood samples were collected from the coccygeal vein during the-8 to +4 wks around parturition, once per week before the morning feeding.Six healthy control cows(CON) and 6 cows with RP were selected and serum samples at-8,-4, time of diagnosis of disease, and +4 wks relative to parturition were used for analyses. All samples were analyzed for lactate, nonesterified fatty acids(NEFA), β-hydroxybutyrate(BHBA), interleukin-1(IL-1), interleukin-6(IL-6), tumor necrosis factor(TNF), haptoglobin(Hp), and serum amyloid A(SAA).Results: Cows with RP had greater concentrations of serum lactate, IL-1, IL-6, TNF, and SAA in comparison with CON cows. Intriguingly, elevated concentrations of all five variables were observed at-8 and-4 wks before the occurrence of RP compared to healthy cows. Cows with RP also had lower DMI and milk production vs CON animals; however milk composition was not affected by RP.Conclusions: Cows with RP showed an activated innate immunity 8 wks prior to diagnosis of disease. Overall results suggest that serum IL-1, IL- 6, and TNF, and lactate can be used as screening biomarkers to indicate cows that might have health issues during the transition period. | Elda Dervishi Guanshi Zhang Dagnachew Hailemariam Suzana M.Dunn Burim N.Ametaj | 2016 | Journal of Animal Science and Biotechnology2016，7，3： | 2 |
| 8 | Optical Amplification at 1525 nm in BaYF5: 20% Yb3+, 2% Er3+ Nanocrystals Doped SU-8 Polymer Waveguide显示文摘 | Pengcheng Zhao Meiling Zhang Tianjiao Wang Xinyang Liu Xuesong Zhai Guanshi Qin Weiping Qin Fei Wang Daming Zhang Tong Zhang | 2014 | Journal of Nanomaterials2014，，： | 1 |
| 9 | Significant enhancement of multiple resonant sidebands in a soliton fiber laser显示文摘Resonant sidebands in soliton fiber lasers have garnered substantial interest in recent years due to their crucial role in understanding soliton propagation and interaction dynamics.However,most previous studies and applications were restricted to focusing on only the first few low-order resonant sidebands because higher-order sidebands usually decay exponentially as their wavelengths shift far away from the soliton center and are negligibly weak.Here we report numerically and experimentally significant enhancement of multiple resonant sidebands in a soliton fiber laser mode-locked by a nonlinear polarization evolution mechanism.The birefringence and the gain profile of the laser cavity were shown to be critical for this phenomenon.Multiple intense resonant sidebands were generated whose maximum intensity was more than 30 d B higher than that of the soliton,which is the highest yet reported,to our knowledge.To accurately predict the wavelengths of all high-order resonant sidebands,an explicit formula was derived by taking the third-order dispersion effect into account.The temporal features of multiple orders of resonant sidebands were characterized,which all exhibit exponentially decaying leading edges.This study provides insight into understanding the properties of high-order resonant sidebands in a soliton laser and opens possibilities for constructing multi-wavelength laser sources. | TIANQI ZHANG FANCHAO MENG QI YAN CHUANZE ZHANG ZHIXU JIA WEIPING QIN GUANSHI QIN HUAILIANG XU | 2023 | Photonics Research2023，11，11： | 0 |
| 10 | Living environment shaped residents’willingness to pay for ecosystem services in Yangtze River Middle Reaches Megalopolis,China显示文摘Profound understanding on the diversity of local residents’willingness to pay(WTP)for ecosystem services(ESs)may aid evaluation of policy impacts by uncovering trade-offs and synergies for achieving sustainable environmental resource management.However,the reasons for the spatial preference heterogeneity of WTP are still unclear.In this study,an extensive survey with 4,580 residents in the Yangtze River Middle Reaches Megalopolis(YRMRM),central China,was carried out to investigate the public’s WTP to maintain and improve ESs.We identified key influencing factors and explored how they shaped the preference heterogeneity in WTP by random forest model and surface fitting method.Our results showed that 81.4% of residents reported WTP for ESs greater than zero.Water supply,waste treatment,food supply and raw material supply were the preferred ESs for residents.Living environment factors(i.e.,extent of farmland,water and forest near the residence)were found as the key drivers of WTP.Proximity to farmland,water and forests resulted in high WTP values for a series of specific ESs.The reasons for the heterogeneity of WTP are(1)the difference in proximity to farmland,water and forest(i.e.,the contributor to ESs),(2)the divergence of local residents’preferences for ESs.This study disclosed the heterogeneity and causes of public preferences in YRMRM,which could help policy and decision makers to develop eco-compensation initiatives towards conservative and sustainable use of the environmental resources. | Guanshi Zhang Qi Zhang Xin Yang Ruying Fang Hongjuan Wu Sen Li | 2023 | Geography and Sustainability2023，4，3： | 0 |
| 11 | 10-GHz broadband optical frequency comb generation at 1550/1310 nm显示文摘The generation of high-repetition rate(frep≥10 GHz)ultra-broadband optical frequency combs(OFCs)at 1550 nm and 1310 nm is investigated by seeding two types of highly nonlinear fibers(HNLFs)with 10 GHz picosecond pulses at the pump wavelength of 1550 nm.When pumped near the zero dispersion wavelength(ZDW)in the normal dispersion region of a HNLF,10 GHz flat-topped OFC with 43 nm bandwidth within 5 dB power variation is generated by self-phase modulation(SPM)-based OFC spectral broadening at 26.5 dBm pump power,and 291 fs pulse trains with 10 GHz repetition rate are obtained at 18 dBm pump power without complicated pulse shaping methods.Furthermore,when pumped in the abnormal dispersion region of a HNLF,OFCs with dispersive waves around 1310 nm are studied using a common HNLF and fluorotellurite fibers,which maintain the good coherence of the pump light at 1550 nm.At the same time,sufficient tunability of the generated dispersive waves is achieved when tuning the pump power or ZDW. | Junyuan Han Yali Huang Jiliang Wu Zhenrui Li Yuede Yang Jinlong Xiao Daming Zhang Guanshi Qin Yongzhen Huang | 2020 | Opto-Electronic Advances2020，3，7： | 0 |
| 12 | Fully Conjugated Covalent Organic Frameworks:Synthesis,Structures and Applications显示文摘This review presents a comprehensive examination of fully conjugated covalent organic frameworks(COFs),which constitute an emerging class of porous materials with immense potential for diverse applications.This article focuses on diversified fully conjugated COFs,including sp2 carbon-carbon linkages,pyrazine linkages,benzobisoxazole linkages,dioxin linkages,β-aminoalkenone linkages,etc.The synthesis techniques and structural attributes of these COFs are expounded upon in great detail,along with their potential applications in various fields.The review thus provides a valuable resource for researchers keen on delving into the synthesis and applications of fully conjugated COFs,thereby highlighting their potential for developing novel functional materials with distinctive properties. | Yueshuai Xu Guanshi Ren Dianqi Zhang Lishui Sun Yingjie Zhao | 2023 | Chinese Journal of Chemistry2023，41，23： | 0 |
| 13 | Combination of effective color information and machine learning for rapid prediction of soil water content显示文摘Soil water content(SWC)is one of the critical indicators in various fields such as geotechnical engineering and agriculture.To avoid the time-consuming,destructive,and laborious drawbacks of conventional SWC measurements,the image-based SWC prediction is considered based on recent advances in quantitative soil color analysis.In this study,a promising method based on the Gaussian-fitting gray histogram is proposed for extracting characteristic parameters by analyzing soil images,aiming to alleviate the interference of complex surface conditions with color information extraction.In addition,an identity matrix consisting of 32 characteristic parameters from eight color spaces is constituted to describe the multi-dimensional information of the soil images.Meanwhile,a subset of 10 parameters is identified through three variable analytical methods.Then,four machine learning models for SWC prediction based on partial least squares regression(PLSR),random forest(RF),support vector machines regression(SVMR),and Gaussian process regression(GPR),are established using 32 and 10 characteristic parameters,and their performance is compared.The results show that the characteristic parameters obtained by Gaussian-fitting can effectively reduce the interference from soil surface conditions.The RGB,CIEXYZ,and CIELCH color spaces and lightness parameters,as the inputs,are more suitable for the SWC prediction models.Furthermore,it is found that 10 parameters could also serve as optimal and generalizable predictors without considerably reducing prediction accuracy,and the GPR model has the best prediction performance(R^(2)≥0.95,RMSE≤2.01%,RPD≥4.95,and RPIQ≥6.37).The proposed image-based SWC predictive models combined with effective color information and machine learning can achieve a transient and highly precise SWC prediction,providing valuable insights for mapping soil moisture fields. | Guanshi Liu Shengkui Tian Guofang Xu Chengcheng Zhang Mingxuan Cai | 2023 | Journal of Rock Mechanics and Geotechnical Engineering2023，15，9： | 0 |
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