The excitation and emission spectra, the relaxation time of principal spectral lines and multi-diffused reflection spectra in LaOCl: Er, LaOCl: Ho powder samples were measured. The diffused absorption spectrum was der...The excitation and emission spectra, the relaxation time of principal spectral lines and multi-diffused reflection spectra in LaOCl: Er, LaOCl: Ho powder samples were measured. The diffused absorption spectrum was derived from the multi-diffused reflection spectrum. According to Judd-Ofelt theory,the intensity parameters, radiative transition probabilities and quantum efficiencies of luminescence emission were calculated. Then comparison with erbium and holmium doped floride glass and other matrices were made.展开更多
For realizing diffused anode attachment in pure nitrogen arcs, a special arc plasma generator was designed and combined with suitable working parameters such as gas flow rate and arc current. The anode has a flow-rest...For realizing diffused anode attachment in pure nitrogen arcs, a special arc plasma generator was designed and combined with suitable working parameters such as gas flow rate and arc current. The anode has a flow-restrictor channel of 2.8 mm diameter and downstream expansion half-angle of 8°, with the purpose of creating a dispersed nitrogen-arc column by strong gasdynamic expansion effect. Results show that, when thermal blocking condition existed in the flow restrictor and the cathode cavity pressure was higher than that in the exit chamber by at least 9 kPa, the action due to gasdynamic expansion could be much stronger than the self-magnetic contraction effect of the arc and the nitrogen arc column could be effectively dispersed to form a sufficiently diffused attachment on the water-cooled anode surface.展开更多
Rare earth co-permeation of (NH4)3[CrMo6O24H6]·7H2O was reported and the conductivity of (NH4)3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry (XRF), thermogravimetry-dif...Rare earth co-permeation of (NH4)3[CrMo6O24H6]·7H2O was reported and the conductivity of (NH4)3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry (XRF), thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) have been used to character (NH4)3[CrMo6O24H6]·7H2O and permeated sample. Experimental results showed that Nd could be permeated into the body of this sample and the XRD patterns showed great difference between (NH4)3[CrMo6O24H6]·7H2O and permeated sample. The structure of (NH4)3[CrMo6O24H6]·7H2O was destroyed and new compound MoN perhaps formed.展开更多
Improper use of chemical fertilizers is an essential reason for diffused pollution of agriculture. Therefore,finding out influence factors of farmers in application of chemical fertilizers will play a significant role...Improper use of chemical fertilizers is an essential reason for diffused pollution of agriculture. Therefore,finding out influence factors of farmers in application of chemical fertilizers will play a significant role in controlling the diffused pollution of agriculture. Through field survey,a total of 340 samples in 4 counties of Chongqing Municipality were obtained. On the basis of these samples,an empirical study was carried out. The study results indicate that farmers' application of chemical fertilizers is negatively correlated with farmers' age,education level,male labor proportion,and soil fertility,while the annual family income,agricultural production population proportion,commodity trading characteristics,and scientific fertilizer application ability fail to pass the significance test. These results will provide reference for proper application of chemical fertilizers and controlling diffused pollution.展开更多
This article proposes a diffused hepatitis B virus (HBV) model with CTL immune response and nonlinear incidence for the control of viral infections. By means of different Lyapunov functions, the global asymptotical ...This article proposes a diffused hepatitis B virus (HBV) model with CTL immune response and nonlinear incidence for the control of viral infections. By means of different Lyapunov functions, the global asymptotical properties of the viral-free equilibrium and immune-free equilibrium of the model are obtained. Global stability of the positive equilibrium of the model is also considered. The results show that the free diffusion of the virus has no effect on the global stability of such HBV infection problem with Neumann homogeneous boundary conditions.展开更多
To improve the low thermal conductivities and poor wear resistances of TC4(Ti-6Al-4V)alloy,the most widely used titanium alloy,the surface of TC4 alloys is modified by electroplating deposition of Ni and Cu layers,and...To improve the low thermal conductivities and poor wear resistances of TC4(Ti-6Al-4V)alloy,the most widely used titanium alloy,the surface of TC4 alloys is modified by electroplating deposition of Ni and Cu layers,and then heat-treated to increase the diffusivity at the interface.In this paper,the corrosion behavior of Cu/Ni coatings on TC4 alloy at different heat treatment processes was investigated in 3.5 wt%Na Cl by the electrochemical analysis,and the microstructure and composition of corrosion products was carried out to reveal the corrosion resistance mechanism of Cu/Ni coatings.It was found that the corrosion resistance was significantly influenced by heat treatment temperature.With the increasing diffusion treatment temperature from 500 to 700℃,the corrosion potential positively shifted from-330.87 to-201.14 m V,and the corrosion current density decreased from 4.02×10^-3 to 0.514×10^-3 m A/cm^2.However,when heat treatment temperature increased to 800℃,the corrosion potential negatively shifted to-207.21 m V,and the current density increased to 1.62×10^-3 m A/cm^2.The diffusion behavior of Ti,Ni and Cu elements occurred and small amounts of Ni and Ti elements appeared on the specimen surface under different heat treatment temperature.Especially heattreated at 700℃,the smaller pore size,dense Cu2O film,and highly stable Ti O and Ni O oxide layer were formed,which dramatically enhanced the corrosion resistance of Cu/Ni coatings.Finally,a novel model of corrosion resistance was proposed based on the analysis mentioned above.展开更多
The commercial 42 M Nd-Fe-B magnet was treated by grain boundary diffusion(GBD)with Pr_(70)Co_(30)(PC),Pr_(70)Al_(30)(PA)and Pr_(70)Co_(15)Al_(15)(PCA)alloys,respectively.The mechanism of coercivity enhancement in the...The commercial 42 M Nd-Fe-B magnet was treated by grain boundary diffusion(GBD)with Pr_(70)Co_(30)(PC),Pr_(70)Al_(30)(PA)and Pr_(70)Co_(15)Al_(15)(PCA)alloys,respectively.The mechanism of coercivity enhancement in the GBD magnets was investigated.The coercivity was enhanced from 1.63 T to 2.15 T in the PCA GBD magnet,higher than the 1.81 T of the PC GBD magnet and the 2.01 T of the PA GBD magnet.This indicates that the joint addition of Co and Al in the diffusion source can further improve the coercivity.Microstructural investigations show that the coercivity enhancement is mainly attributed to the exchange-decoupling of the GB phases.In the PCA GBD magnet,the wider thin GB phases can be formed and the thin GB phases can still be observed at the diffusion depth of 1500μm due to the combined action of Co and Al.At the same time,the formation of the Pr-rich shell can also be observed,which is helpful for the coercivity enhancement.展开更多
The effects of chemical gas-phase RE diffused permeation on the corrosion resistivity of albronze alloys were studied by X-ray photoelectron spectroscopy, ion probe exfoliation corrosion analysis, and scanning electro...The effects of chemical gas-phase RE diffused permeation on the corrosion resistivity of albronze alloys were studied by X-ray photoelectron spectroscopy, ion probe exfoliation corrosion analysis, and scanning electron microscopy, etc. The results show that small quantity of cerium has permeated and diffused into the surface of this alloy. The potential-time curves, alternating current impedance tests and weight loss tests proved that cerium permeation can improve the corrosion resistivity of the albronze surface.展开更多
This paper focuses on the high intensity filaments (dye patches) embedded in dye plumes in a wall-bounded shear flow, to investigate the shear effect on the dye patch distribution. Motivated by the widely concerned in...This paper focuses on the high intensity filaments (dye patches) embedded in dye plumes in a wall-bounded shear flow, to investigate the shear effect on the dye patch distribution. Motivated by the widely concerned inverse estimation of the source location, we try extracting useful information to know the source location from down-stream dye patches. Accordingly, we changed the dye injection location at different distances from the wall and made observations at different downstream (diffusion) distances from the source. The orientation angle and roundness of dye patches were concerned to examine the shear effect and dye patch characteristics. To capture the dye plume images, a planar laser induced fluorescence (PLIF) technique was used. The orientation and roundness of each dye patch were calculated by least-square fitting. The statistics of both the orientation angle and the roundness were compared with those in homogeneous turbulent cases to reveal the shear effect. Different from uniformly-orientated dye patches in the homogeneous flow, larger occurrence probabilities with positive orientation angles of dye patches are observed in wall-bounded shear flow, in particular, when the injection location is near the wall. As with information extraction for the inverse estimation of source location, it is found that the orientation distribution of dye patches is independent of the diffusion distance, but related with the injection location from the wall. While for the homogeneous flow cases, a strong dependence on the diffusion distance is observed in the orientation distribution profiles. As for the roundness, similar aspects are found regarding the dependencies on the injection location in shear flow and on diffusion distance in homogeneous flow.展开更多
Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) alloys.The effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and...Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) alloys.The effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and elements distribution of GBDed magnets was investigated.When Pr is used to substitute for 75% Tb in diffusion source,Tb consumption per unit coercivity improvement of GBDed magnet reduces by 77%,compared with the Tb_(80)Al_(10)Ga_(10) diffused magnet.Tb element diffuses into magnets and then forms Tb-rich shell with high magneto-crystalline anisotropy field surrounding main phase grains,resulting in substantial coercivity improvement.Pr with low melting point diffuses deeply along liquid grain boundary phase during GBD process.It can eliminate some sharp defects of main phase grains and make grain boundaries smooth,which provides diffusion channels for further diffusion of Tb element.Therefore,there are more diffusion channels for Tb and less Tb enriched at surface region,making Tb diffuse more deeply and improving Tb utilization efficiency.This method significantly improves the coercivity,and realizes the green,efficient and high-quality utilization of heavy rare earth(HRE)elements.展开更多
A vector bending fiber sensor based on core-by-core inscribed fiber Bragg gratings in a twin-core fiber has been proposed and experimentally demonstrated.An in-fiber integrated vector bending sensor is realized by usi...A vector bending fiber sensor based on core-by-core inscribed fiber Bragg gratings in a twin-core fiber has been proposed and experimentally demonstrated.An in-fiber integrated vector bending sensor is realized by using the thermal diffusion technique to fabricate the coupler.The characteristics of the coupler fabricated by thermal diffusion are simulated and experimented.By inscribing fiber Bragg gratings with different reflection wavelengths in the two cores of a symmetrical twin-core fiber,the curvature sensitivity can be enhanced by tracking the wavelength difference between the fiber Bragg gratings of the two cores.The measured bending sensitivity of the fiber Bragg grating ranges from–161.6 pm/m^(−1) to+165.5 pm/m^(−1).The differential sensitivity of the two cores is twice that of a conventional single grating,and the temperature-induced crosstalk is also reduced.The bending sensor proposed in this paper has the advantages of high integration,enhancing the sensitivity and two-dimensional orientation recognizability,and reducing temperature crosstalk,which can be a promising candidate for structural health monitoring or wearable artificial electronics applications.展开更多
Multi-material laser-based powder bed fusion (PBF-LB) allows manufacturing of parts with 3-dimensional gradient and additional functionality in a single step. This research focuses on the combination of thermally-cond...Multi-material laser-based powder bed fusion (PBF-LB) allows manufacturing of parts with 3-dimensional gradient and additional functionality in a single step. This research focuses on the combination of thermally-conductive CuCr1Zr with hard M300 tool steel.Two interface configurations of M300 on CuCr1Zr and CuCr1Zr on M300 were investigated. Ultra-fine grains form at the interface due to the low mutual solubility of Cu and steel. The material mixing zone size is dependent on the configurations and tunable in the range of0.1–0.3 mm by introducing a separate set of parameters for the interface layers. Microcracks and pores mainly occur in the transition zone.Regardless of these defects, the thermal diffusivity of bimetallic parts with 50vol% of CuCr1Zr significantly increases by 70%–150%compared to pure M300. The thermal diffusivity of CuCr1Zr and the hardness of M300 steel can be enhanced simultaneously by applying the aging heat treatment.展开更多
Background: It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease (CAD). Coronary endarterectomy (CE) offers an alternative choice of coronary...Background: It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease (CAD). Coronary endarterectomy (CE) offers an alternative choice of coronary artery reconstruction and revascularization. In this study, short-term result of CE combined with coronary artery bypass graft (CABG) was discussed in the treatment for the diffused CAD. Methods: From January 2012 to April 2014, 221 cases of CABG were performed by the same surgeon in our unit. Among these cases, 38 cases of CE + CABG were pertbrmed, which was about 17.2% (38/221) of the cohort. All these patients were divided into two groups: CE + CABG group (Group A) and CABG alone group and postoperative complications and in-hospital mortality were Chi-square test and Student's t-test respectively. (Group B). All clinical data were compared between the two groups, analyzed. The categorical and continuous variables were analyzed by Results: Diabetes mellitus, hypertension, hyperlipidemia, and peripheral vascular disease were more common in group A. In this cohort, a total of 50 vessels were endarterectomized. Among them, CE was perfbrmed on left anterior descending artery in 11 cases, on right coronary artery in 29 cases, on diagonal artery in 3 cases, on intermediate artery in 2 cases, on obtuse marginal artery in 5 cases. There was no hospital mortality in both groups. The intro-aortic balloon pump was required in 3 cases in Group A (3/38), which was more often than that in Group B (3/183). At the time of follow-up, coronary computed tomography angiogram showed all the grafts with CE were patent (50/50). There is no cardio-related mortality in both groups. All these patients were free from coronary re-intervention. Conclusions: Coronary endarterectomy + CABG can oilier satisfactory result for patients with diffused CAD in a short-term after the operation.展开更多
This compendium review focuses on the spatial distribution of sensitivity to localized absorption changes in optically diffuse media,particularly for measurements relevant to near-infrared spectroscopy.The three tempo...This compendium review focuses on the spatial distribution of sensitivity to localized absorption changes in optically diffuse media,particularly for measurements relevant to near-infrared spectroscopy.The three temporal domains,continuous wave,frequency domain,and time domain,each obtain different optical data types whose changes may be related to effective homogeneous changes in the absorption coefficient.Sensitivity is the relationship between a localized perturbation and the recovered effective homogeneous absorption change.Therefore,spatial sensitivity maps representing the perturbation location can be generated for the numerous optical data types in the three temporal domains.The review first presents a history of the past 30 years of work investigating this sensitivity in optically diffuse media.These works are experimental and theoretical,presenting one-,two-,and three-dimensional sensitivity maps for different Near-Infrared Spectroscopy methods,domains,and data types.Following this history,we present a compendium of sensitivity maps organized by temporal domain and then data type.This compendium provides a valuable tool to compare the spatial sensitivity of various measurement methods and parameters in one document.Methods for one to generate these maps are provided in Appendix A,including the code.This historical review and comprehensive sensitivity map compendium provides a single source researchers may use to visualize,investigate,compare,and generate sensitivity to localized absorption change maps.展开更多
文摘The excitation and emission spectra, the relaxation time of principal spectral lines and multi-diffused reflection spectra in LaOCl: Er, LaOCl: Ho powder samples were measured. The diffused absorption spectrum was derived from the multi-diffused reflection spectrum. According to Judd-Ofelt theory,the intensity parameters, radiative transition probabilities and quantum efficiencies of luminescence emission were calculated. Then comparison with erbium and holmium doped floride glass and other matrices were made.
基金supported by the National Natural Science Foundation of China (11575273)
文摘For realizing diffused anode attachment in pure nitrogen arcs, a special arc plasma generator was designed and combined with suitable working parameters such as gas flow rate and arc current. The anode has a flow-restrictor channel of 2.8 mm diameter and downstream expansion half-angle of 8°, with the purpose of creating a dispersed nitrogen-arc column by strong gasdynamic expansion effect. Results show that, when thermal blocking condition existed in the flow restrictor and the cathode cavity pressure was higher than that in the exit chamber by at least 9 kPa, the action due to gasdynamic expansion could be much stronger than the self-magnetic contraction effect of the arc and the nitrogen arc column could be effectively dispersed to form a sufficiently diffused attachment on the water-cooled anode surface.
基金the Key Science and Technology Foundation of Heilongjiang Province(Grant No.GB02A301) National Natural Science Foundation of China(Grant No.2037101)
文摘Rare earth co-permeation of (NH4)3[CrMo6O24H6]·7H2O was reported and the conductivity of (NH4)3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry (XRF), thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) have been used to character (NH4)3[CrMo6O24H6]·7H2O and permeated sample. Experimental results showed that Nd could be permeated into the body of this sample and the XRD patterns showed great difference between (NH4)3[CrMo6O24H6]·7H2O and permeated sample. The structure of (NH4)3[CrMo6O24H6]·7H2O was destroyed and new compound MoN perhaps formed.
基金Supported by Major Project of Key Research Base of Humanities and Social Science of Chongqing Municipality(11SKB31)Social Science Planning Project of Chongqing Municipality(2014YBGL130)
文摘Improper use of chemical fertilizers is an essential reason for diffused pollution of agriculture. Therefore,finding out influence factors of farmers in application of chemical fertilizers will play a significant role in controlling the diffused pollution of agriculture. Through field survey,a total of 340 samples in 4 counties of Chongqing Municipality were obtained. On the basis of these samples,an empirical study was carried out. The study results indicate that farmers' application of chemical fertilizers is negatively correlated with farmers' age,education level,male labor proportion,and soil fertility,while the annual family income,agricultural production population proportion,commodity trading characteristics,and scientific fertilizer application ability fail to pass the significance test. These results will provide reference for proper application of chemical fertilizers and controlling diffused pollution.
基金supported by the National Natural Science Foundation of China(10971166,10901131)the National High Technology Research and Development Program of China(863 Program,2009AA01A135)the Natural Science Foundation of Xinjiang Province(2010211B04)
文摘This article proposes a diffused hepatitis B virus (HBV) model with CTL immune response and nonlinear incidence for the control of viral infections. By means of different Lyapunov functions, the global asymptotical properties of the viral-free equilibrium and immune-free equilibrium of the model are obtained. Global stability of the positive equilibrium of the model is also considered. The results show that the free diffusion of the virus has no effect on the global stability of such HBV infection problem with Neumann homogeneous boundary conditions.
基金Funded by Key Projects of Shaanxi Natural Science Foundation(No.2019JZ-27)Shaanxi Natural Science Basic Research Program-Shaanxi Coal(No.2019JLM-47)Fundamental Research Funds for the Central Universities CHD(No.300102319304).
文摘To improve the low thermal conductivities and poor wear resistances of TC4(Ti-6Al-4V)alloy,the most widely used titanium alloy,the surface of TC4 alloys is modified by electroplating deposition of Ni and Cu layers,and then heat-treated to increase the diffusivity at the interface.In this paper,the corrosion behavior of Cu/Ni coatings on TC4 alloy at different heat treatment processes was investigated in 3.5 wt%Na Cl by the electrochemical analysis,and the microstructure and composition of corrosion products was carried out to reveal the corrosion resistance mechanism of Cu/Ni coatings.It was found that the corrosion resistance was significantly influenced by heat treatment temperature.With the increasing diffusion treatment temperature from 500 to 700℃,the corrosion potential positively shifted from-330.87 to-201.14 m V,and the corrosion current density decreased from 4.02×10^-3 to 0.514×10^-3 m A/cm^2.However,when heat treatment temperature increased to 800℃,the corrosion potential negatively shifted to-207.21 m V,and the current density increased to 1.62×10^-3 m A/cm^2.The diffusion behavior of Ti,Ni and Cu elements occurred and small amounts of Ni and Ti elements appeared on the specimen surface under different heat treatment temperature.Especially heattreated at 700℃,the smaller pore size,dense Cu2O film,and highly stable Ti O and Ni O oxide layer were formed,which dramatically enhanced the corrosion resistance of Cu/Ni coatings.Finally,a novel model of corrosion resistance was proposed based on the analysis mentioned above.
基金Project supported by the Key Research and Development Program of Zhejiang ProvinceChina(Grant No.2021C01190)+4 种基金the Major Project of Science and Technology Innovation 2025 in Ningbo CityChina(Grant No.2018B10015)Zhejiang Province Public Welfare Technology Application Research Project(Grant No.LGG21E010007)the Inner Mongolia Major Technology Projectthe K.C.Wong Magna Fund in Ningbo University。
文摘The commercial 42 M Nd-Fe-B magnet was treated by grain boundary diffusion(GBD)with Pr_(70)Co_(30)(PC),Pr_(70)Al_(30)(PA)and Pr_(70)Co_(15)Al_(15)(PCA)alloys,respectively.The mechanism of coercivity enhancement in the GBD magnets was investigated.The coercivity was enhanced from 1.63 T to 2.15 T in the PCA GBD magnet,higher than the 1.81 T of the PC GBD magnet and the 2.01 T of the PA GBD magnet.This indicates that the joint addition of Co and Al in the diffusion source can further improve the coercivity.Microstructural investigations show that the coercivity enhancement is mainly attributed to the exchange-decoupling of the GB phases.In the PCA GBD magnet,the wider thin GB phases can be formed and the thin GB phases can still be observed at the diffusion depth of 1500μm due to the combined action of Co and Al.At the same time,the formation of the Pr-rich shell can also be observed,which is helpful for the coercivity enhancement.
文摘The effects of chemical gas-phase RE diffused permeation on the corrosion resistivity of albronze alloys were studied by X-ray photoelectron spectroscopy, ion probe exfoliation corrosion analysis, and scanning electron microscopy, etc. The results show that small quantity of cerium has permeated and diffused into the surface of this alloy. The potential-time curves, alternating current impedance tests and weight loss tests proved that cerium permeation can improve the corrosion resistivity of the albronze surface.
文摘This paper focuses on the high intensity filaments (dye patches) embedded in dye plumes in a wall-bounded shear flow, to investigate the shear effect on the dye patch distribution. Motivated by the widely concerned inverse estimation of the source location, we try extracting useful information to know the source location from down-stream dye patches. Accordingly, we changed the dye injection location at different distances from the wall and made observations at different downstream (diffusion) distances from the source. The orientation angle and roundness of dye patches were concerned to examine the shear effect and dye patch characteristics. To capture the dye plume images, a planar laser induced fluorescence (PLIF) technique was used. The orientation and roundness of each dye patch were calculated by least-square fitting. The statistics of both the orientation angle and the roundness were compared with those in homogeneous turbulent cases to reveal the shear effect. Different from uniformly-orientated dye patches in the homogeneous flow, larger occurrence probabilities with positive orientation angles of dye patches are observed in wall-bounded shear flow, in particular, when the injection location is near the wall. As with information extraction for the inverse estimation of source location, it is found that the orientation distribution of dye patches is independent of the diffusion distance, but related with the injection location from the wall. While for the homogeneous flow cases, a strong dependence on the diffusion distance is observed in the orientation distribution profiles. As for the roundness, similar aspects are found regarding the dependencies on the injection location in shear flow and on diffusion distance in homogeneous flow.
基金Project supported by the National Key Research and Development Program of China (2022YFB3503303)。
文摘Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) alloys.The effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and elements distribution of GBDed magnets was investigated.When Pr is used to substitute for 75% Tb in diffusion source,Tb consumption per unit coercivity improvement of GBDed magnet reduces by 77%,compared with the Tb_(80)Al_(10)Ga_(10) diffused magnet.Tb element diffuses into magnets and then forms Tb-rich shell with high magneto-crystalline anisotropy field surrounding main phase grains,resulting in substantial coercivity improvement.Pr with low melting point diffuses deeply along liquid grain boundary phase during GBD process.It can eliminate some sharp defects of main phase grains and make grain boundaries smooth,which provides diffusion channels for further diffusion of Tb element.Therefore,there are more diffusion channels for Tb and less Tb enriched at surface region,making Tb diffuse more deeply and improving Tb utilization efficiency.This method significantly improves the coercivity,and realizes the green,efficient and high-quality utilization of heavy rare earth(HRE)elements.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2019YFB2203903)National Natural Science Foundation of China(Grant Nos.61827819,61735009,and 61905154)+1 种基金partially supported by special fund for Bagui Scholars Program of Guangxi Zhuang Autonomous Region(Grant No.2019A38)Guangxi Innovation-Driven Development Project(Grant No.AA18242043).
文摘A vector bending fiber sensor based on core-by-core inscribed fiber Bragg gratings in a twin-core fiber has been proposed and experimentally demonstrated.An in-fiber integrated vector bending sensor is realized by using the thermal diffusion technique to fabricate the coupler.The characteristics of the coupler fabricated by thermal diffusion are simulated and experimented.By inscribing fiber Bragg gratings with different reflection wavelengths in the two cores of a symmetrical twin-core fiber,the curvature sensitivity can be enhanced by tracking the wavelength difference between the fiber Bragg gratings of the two cores.The measured bending sensitivity of the fiber Bragg grating ranges from–161.6 pm/m^(−1) to+165.5 pm/m^(−1).The differential sensitivity of the two cores is twice that of a conventional single grating,and the temperature-induced crosstalk is also reduced.The bending sensor proposed in this paper has the advantages of high integration,enhancing the sensitivity and two-dimensional orientation recognizability,and reducing temperature crosstalk,which can be a promising candidate for structural health monitoring or wearable artificial electronics applications.
基金supported by VTT Technical Research Centre of Finland,Aalto University,Aerosint SA,and partially from European Union Horizon 2020 (No.768775)。
文摘Multi-material laser-based powder bed fusion (PBF-LB) allows manufacturing of parts with 3-dimensional gradient and additional functionality in a single step. This research focuses on the combination of thermally-conductive CuCr1Zr with hard M300 tool steel.Two interface configurations of M300 on CuCr1Zr and CuCr1Zr on M300 were investigated. Ultra-fine grains form at the interface due to the low mutual solubility of Cu and steel. The material mixing zone size is dependent on the configurations and tunable in the range of0.1–0.3 mm by introducing a separate set of parameters for the interface layers. Microcracks and pores mainly occur in the transition zone.Regardless of these defects, the thermal diffusivity of bimetallic parts with 50vol% of CuCr1Zr significantly increases by 70%–150%compared to pure M300. The thermal diffusivity of CuCr1Zr and the hardness of M300 steel can be enhanced simultaneously by applying the aging heat treatment.
文摘Background: It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease (CAD). Coronary endarterectomy (CE) offers an alternative choice of coronary artery reconstruction and revascularization. In this study, short-term result of CE combined with coronary artery bypass graft (CABG) was discussed in the treatment for the diffused CAD. Methods: From January 2012 to April 2014, 221 cases of CABG were performed by the same surgeon in our unit. Among these cases, 38 cases of CE + CABG were pertbrmed, which was about 17.2% (38/221) of the cohort. All these patients were divided into two groups: CE + CABG group (Group A) and CABG alone group and postoperative complications and in-hospital mortality were Chi-square test and Student's t-test respectively. (Group B). All clinical data were compared between the two groups, analyzed. The categorical and continuous variables were analyzed by Results: Diabetes mellitus, hypertension, hyperlipidemia, and peripheral vascular disease were more common in group A. In this cohort, a total of 50 vessels were endarterectomized. Among them, CE was perfbrmed on left anterior descending artery in 11 cases, on right coronary artery in 29 cases, on diagonal artery in 3 cases, on intermediate artery in 2 cases, on obtuse marginal artery in 5 cases. There was no hospital mortality in both groups. The intro-aortic balloon pump was required in 3 cases in Group A (3/38), which was more often than that in Group B (3/183). At the time of follow-up, coronary computed tomography angiogram showed all the grafts with CE were patent (50/50). There is no cardio-related mortality in both groups. All these patients were free from coronary re-intervention. Conclusions: Coronary endarterectomy + CABG can oilier satisfactory result for patients with diffused CAD in a short-term after the operation.
文摘This compendium review focuses on the spatial distribution of sensitivity to localized absorption changes in optically diffuse media,particularly for measurements relevant to near-infrared spectroscopy.The three temporal domains,continuous wave,frequency domain,and time domain,each obtain different optical data types whose changes may be related to effective homogeneous changes in the absorption coefficient.Sensitivity is the relationship between a localized perturbation and the recovered effective homogeneous absorption change.Therefore,spatial sensitivity maps representing the perturbation location can be generated for the numerous optical data types in the three temporal domains.The review first presents a history of the past 30 years of work investigating this sensitivity in optically diffuse media.These works are experimental and theoretical,presenting one-,two-,and three-dimensional sensitivity maps for different Near-Infrared Spectroscopy methods,domains,and data types.Following this history,we present a compendium of sensitivity maps organized by temporal domain and then data type.This compendium provides a valuable tool to compare the spatial sensitivity of various measurement methods and parameters in one document.Methods for one to generate these maps are provided in Appendix A,including the code.This historical review and comprehensive sensitivity map compendium provides a single source researchers may use to visualize,investigate,compare,and generate sensitivity to localized absorption change maps.