The preparation of γ-Fe<sub>2</sub>O<sub>3</sub>/Gd<sub>2</sub>O<sub>3</sub> nanocomposite for possible use in magnetic hyperthermia application was done by ball millin...The preparation of γ-Fe<sub>2</sub>O<sub>3</sub>/Gd<sub>2</sub>O<sub>3</sub> nanocomposite for possible use in magnetic hyperthermia application was done by ball milling technique. The nanocomposite was characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The heating efficiency and the effect of milling time (5 h and 30 h) on the structural and magnetic properties of the nanocomposite were reported. XRD analysis confirms the formation of the nanocomposite, while magnetization measurements show that the milled sample present hysteresis with low coercivity and remanence. The specific absorption rate (SAR) under an alternating magnetic field is investigated as a function of the milling time. A mean heating efficiency of 68 W/g and 28.7 W/g are obtained for 5 h and 30 h milling times respectively at 332 kHz and 170 Oe. The results showed that the obtained nanocomposite for 5 h milling time is a promising candidate for magnetic hyperthermia due to his properties which show an interesting magnetic behavior and high specific absorption rate.展开更多
Flaxseed has displayed the potential beneficial as functional foods.However,most studies focused on effects of flaxseed extracts or ingredients in flaxseed.Besides,few studies showed that flaxseed extracts contributed...Flaxseed has displayed the potential beneficial as functional foods.However,most studies focused on effects of flaxseed extracts or ingredients in flaxseed.Besides,few studies showed that flaxseed extracts contributed to anti-type 1 diabetes(T1D),yet the underlying mechanism is still unknown.In the present study,16.7% of milled flaxseed(MF)-added diet was given to diabetic mice induced by streptozocin for 6 weeks.The results showed that MF feeding 1)slightly decreased blood glucose levels and improved the ability of glucose tolerance by oral glucose tolerance test,2)decreased liver tumor necrosis factor-αlevels and increased liver glycogen levels with significance via down-regulating TLR4/NF-κB pathways,3)and significantly altered some beneficial bacteria in gut microbiota.In conclusion,the present study showed that milled flaxseed showed the potential on anti-T1D through anti-inflammation via TLR4/NF-κB and altering the gut microbiota in STZ-induced diabetic mice.展开更多
Transmission spectra of triangular lattice photonic crystals milled in the top surface of an annealed protonexchange waveguide are numerically simulated.The effects of the finite depth,conical shape,trapezoidal shape ...Transmission spectra of triangular lattice photonic crystals milled in the top surface of an annealed protonexchange waveguide are numerically simulated.The effects of the finite depth,conical shape,trapezoidal shape and hybrid shape of holes are theoretically analyzed.Due to the difficulty of milling high aspect-ratio cylindrical holes in lithium niobate(LiNbO_3),a compromised solution is proposed to improve the overlap between shallow holes and the waveguide mode,and useful transmission spectra with strong contrast and sharp band edges are achieved.展开更多
<span style="font-family:Verdana;">In work reported here, the dynamic properties and low-velocity impact response of woven carbon/epoxy laminates incorporating a novel 3D interlaminar reinforcement con...<span style="font-family:Verdana;">In work reported here, the dynamic properties and low-velocity impact response of woven carbon/epoxy laminates incorporating a novel 3D interlaminar reinforcement concept with dense layers of Z-axis oriented milled carbon fiber Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> prepregs, are presented. Impulse-frequency response vibration technique is used for non-destructive evaluation of the dynamic flexural modulus (stiffness) and loss factor (intrinsic damping) of woven carbon/epoxy control and Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminates. Low-velocity punch-shear tests were performed on control and Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminates according to ASTM D3763 Standard using a drop-weight impact test system. Control panels had all layers of 3K plain woven carbon/epoxy prepregs, with a dense interlaminar reinforcement of milled carbon fibers in Z-</span><span style="font-family:;" "=""> </span><span><span style="font-family:Verdana;">direction used in designing the Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminate—both having same areal density. Impulse-frequency response vibration experiments show that with a 50% replacement of woven carbon fabric in control panel with milled carbon fibers in Z direction dynamic flexural modulus reduced 25%</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">30% (loss in stiffness) and damping increased by about the same 25%</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">30%. Low-velocity punch-shear tests demonstrated about</span><span style="font-family:;" "=""> </span><span><span style="font-family:Verdana;">25% reduction in energy absorption for Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminates with the replacement of 50% woven carbon fabric in control panel.</span></span>展开更多
The aluminum alloy Al Mn1 Cu has been broadly applied for functional parts production because of its good properties. But few researches about the machining mechanism and the surface roughness were reported. The high-...The aluminum alloy Al Mn1 Cu has been broadly applied for functional parts production because of its good properties. But few researches about the machining mechanism and the surface roughness were reported. The high-speed milling experiments are carried out in order to improve the machining quality and reveal the machining mechanism. The typical topography features of machined surface are observed by scan electron microscope(SEM). The results show that the milled surface topography is mainly characterized by the plastic shearing deformation surface and material piling zone. The material flows plastically along the end cutting edge of the flat-end milling tool and meanwhile is extruded by the end cutting edge, resulting in that materials partly adhere to the machined surface and form the material piling zone. As the depth of cut and the feed per tooth increase, the plastic flow of materials is strengthened and the machined surface becomes rougher. However, as the cutting speed increases, the plastic flow of materials is weakened and the milled surface becomes smoother. The cutting parameters(e.g. cutting speed, feed per tooth and depth of cut)influencing the surface roughness are analyzed. It can be concluded that the roughness of the machined surface formed by the end cutting edge is less than that by the cylindrical cutting edge when a cylindrical flat-end mill tool is used for milling. The proposed research provides the typical topography features of machined surface of the anti-rust aluminum alloy Al Mn1 Cu in high speed milling.展开更多
The influence of spark plasma sintering(SPS)temperature on microstructure,hardness and corrosion behavior of a high-energy ball milled Mg-10wt%Al alloy was investigated in this work.The holding time and sintering pres...The influence of spark plasma sintering(SPS)temperature on microstructure,hardness and corrosion behavior of a high-energy ball milled Mg-10wt%Al alloy was investigated in this work.The holding time and sintering pressure for SPS were kept constant while varying the sintering temperature from 200 to 350℃.The grain size and microstructure were studied using X-ray diffraction analysis,scanning electron microscopy,energy dispersive X-ray spectroscopy,and Archimedes'based density measurement.Corrosion behavior was investigated using potentiodynamic polarization tests.The nanocrystalline regime(grain size<100nm)was maintained even after SPS up to 350℃.The density of the alloy increased with increasing the SPS temperature.Vickers'hardness and corrosion performance improved up to 300℃ followed by a decrease after SPS at 350℃.Possible reasons for densification,strengthening,and corrosion behavior have been discussed in the light of reduced porosity and microstructural changes.展开更多
The Ti6Al4V parts produced by the existing selective laser melting(SLM)are mainly confronted with poor surface finish and inevitable interior defects,which substantially deteriorates the mechanical properties and perf...The Ti6Al4V parts produced by the existing selective laser melting(SLM)are mainly confronted with poor surface finish and inevitable interior defects,which substantially deteriorates the mechanical properties and performances of the parts.In this regard,ultrasonically-assisted machining(UAM)technique is commonly introduced to improve the machining quality due to its merits in increasing tool life and reducing cutting force.However,most of the previous studies focus on the performance of UAM with ultrasonic vibrations applied in the tangential and feed directions,whereas few of them on the impact of ultrasonic vibration along the vertical direction.In this study,the effects of feed rate on surface integrity in ultrasonically-assisted vertical milling(UAVM)of the Ti6Al4V alloy manufactured by SLM were systemically investigated compared with the conventional machining(CM)method.The results revealed that the milling forces in UAVM showed a lower amplitude than that in CM due to the intermittent cutting style.The surface roughness values of the parts produced by UAVM were generally greater than that by CM owing to the extra sinusoidal vibration textures induced by the milling cutter.Moreover,the extra vertical ultrasonic vibration in UAVM was beneficial to suppressing machining chatter.As feed rate increased,surface microhardness and thickness of the plastic deformation zone in CM raised due to more intensive plastic deformation,while these two material properties in UAVM were reduced owing to the mitigated impact effect by the high-frequency vibration of the milling cutter.Therefore,the improved surface microhardness and reduced thickness of the subsurface deformation layer in UAVM were ascribed to the vertical high-frequency impact of the milling cutter in UAVM.In general,the results of this study provided an in-depth understanding in UAVM of Ti6Al4V parts manufactured by SLM.展开更多
Based on analyzing various factors influencing milled surface topography, firstly, a generalized model for milled surface topography is proposed. Secondly, using the principles of transformation matrix and vector oper...Based on analyzing various factors influencing milled surface topography, firstly, a generalized model for milled surface topography is proposed. Secondly, using the principles of transformation matrix and vector operation, the trajectory equation of cutting edge relative to workpiece is derived. Then, a three dimensional topography simulation algorithm is constructed through dividing the workpiece into regular grids. Finally, taking the peripheral milling process as an example, the generalized model is simplified, and the corresponding simulation examples are given. The results indicate that it is very efficient for the generalized model to be used to analyze and simulate the peripherally milled surface topography.展开更多
In order to improve the utilization of milling materials,save stone resources and reduce milling energy consumption,the aged Styrene-butadiene-styrene(SBS)modified asphalt was used as a binder to prepare AC-16 asphal...In order to improve the utilization of milling materials,save stone resources and reduce milling energy consumption,the aged Styrene-butadiene-styrene(SBS)modified asphalt was used as a binder to prepare AC-16 asphalt mixture to simulate old asphalt pavement materials.First,the test and discrete element simulation results of uniaxial compression tests were used to calibrate the parameters of the parallel bonding contact model between asphalt mortar and aggregates.On this basis,a microscopic model of the asphalt mixture was established to simulate the old asphalt pavement.Then,the discrete element software PFC(Particle Flow Code)was used to simulate the milling process of the old asphalt pavement.Analyzed the force of the cutting tool and the utilization rate of milling materials,and the optimal milling speed and milling depth were determined.Finally,the energy consumption in the milling process was measured.It is concluded that in the process of milling the old asphalt pavement,using a cutting angle of 42°,milling speed of 0.5 m/s and milling depth of 20 mm can reduce the wear of the cutting tool.In this case,the direct utilization rate of milling materials is 85.3%,and the rate of energy consumption reduction is 33.53%.After parameter optimization,the utilization rate of milling materials can be increased by 17.4%.展开更多
The nanostructures of the ball milled FeCo particles were characterized as functions of the ball milling time (t) using quantitative X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) an...The nanostructures of the ball milled FeCo particles were characterized as functions of the ball milling time (t) using quantitative X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) analysis techniques. The results show that the nanocrystalline bcc FeCo particles are available using carbonyl iron and cobalt powders as the start materials during the high-energy ball milling. At the early stage of ball milling, Co powders are easily mashed into nanocrystalllites,by which the surface of the larger Fe particles of about 80-150 nm is coated. With t increasing, the refinement of grain size and the incorporation of defects including dislocations, disclinations and grain boundaries happen, and then FeCo alloy with a certain layered structure is formed, finally the layered structure disappears with the formation of isotropic grains having a steady-state grain size in the nanometer regime after a certain period of t.展开更多
In this investigation,mechanical grinding was applied to fabricating the Mg-based alloys La_(7)Sm_(3)Mg_(80)Ni_(10)+5 wt.%M(M=None,TiO_(2),La_(2)O_(3))(named La_(7)Sm_(3)Mg_(80)Ni_(10)-5 M(M=None,TiO_(2),La_(2)O_(3)))...In this investigation,mechanical grinding was applied to fabricating the Mg-based alloys La_(7)Sm_(3)Mg_(80)Ni_(10)+5 wt.%M(M=None,TiO_(2),La_(2)O_(3))(named La_(7)Sm_(3)Mg_(80)Ni_(10)-5 M(M=None,TiO_(2),La_(2)O_(3))).The result reveals that the structures of as-milled alloys consist of amorphous and nanocrystalline.The particle sizes of the added M(M=TiO_(2),La_(2)O_(3))alloys obviously diminish in comparison with the M=None specimen,suggesting that the catalysts TiO_(2)and La_(2)O_(3)can enhance the grinding efficiency.What’s more,the additives TiO_(2)and La_(2)O_(3)observably improve the activation performance and reaction kinetics of the composite.The time required by releasing 3 wt.%hydrogen at553,573 and 593 K is 988,553 and 419 s for the M=None sample,and 578,352 and 286 s for the M=TiO_(2)composite,and 594,366,301 s for the La_(2)O_(3)containing alloy,respectively.The absolute value of hydrogenation enthalpy change|△H|of the M(M=None,TiO_(2),La_(2)O_(3))alloys is 77.13,74.28 and 75.28 kJ/mol.Furthermore,the addition of catalysts reduces the hydrogen desorption activation energy(E_(a)^(de)).展开更多
Due to the hydrogen embrittlement effect,La(Fe,Si)_(13)-based hydrides can only exist in powder form,which limits their practical application.In this work,ductile and thermally conductive Al metal was homogeneously mi...Due to the hydrogen embrittlement effect,La(Fe,Si)_(13)-based hydrides can only exist in powder form,which limits their practical application.In this work,ductile and thermally conductive Al metal was homogeneously mixed with La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)B_(0.2)using the ball milling method.Then hydrogenation and compactness shaping of the magnetocaloric composites were performed in one step via a sintering process under high hydrogen pressure.As the Al content reached 9 wt.%,the La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)B_(0.2)H_(y)/Al composite showed the mechanical behavior of a ductile material with a yield strength of~44 MPa and an ultimate strength of 269 MPa accompanied by a pronounced improvement in thermal conductivity.Due to the ease of formation of Fe-Al-Si phases and the several micron and submicron sizes of the composite particles caused by ball milling process,the magnetic entropy change of the composites was substantially reduced to~1.2 J/kg·K-1.5 J/kg·K at 0 T-1.5 T.展开更多
This paper reports a study on nanocrystalline ceria powder prepared by high energy ball-milling and combustion synthesis methods. The combustion synthesis was carried out using ceric ammonium nitrate as oxidizer and c...This paper reports a study on nanocrystalline ceria powder prepared by high energy ball-milling and combustion synthesis methods. The combustion synthesis was carried out using ceric ammonium nitrate as oxidizer and citric acid, glycine or citric acid plus glycine as fuel. The minimum crystallite size of ceria powder is obtained by combustion synthesis of ceric ammonium nitrate and citric acid. The ceria powder produced by combustion synthesis of ceric ammonium nitrate and citric acid and glycine has less agglomeration of particles than other techniques.展开更多
The loss on drying method,which is regarded as the standard method of rice moisture content analysis,provides the most reliable results but is both labor intensive and time consuming.In order to improve the detection ...The loss on drying method,which is regarded as the standard method of rice moisture content analysis,provides the most reliable results but is both labor intensive and time consuming.In order to improve the detection efficiency of the loss on drying method,this study investigated the drying characteristics of milled rice and developed an information fusion algorithm with which to predict milled rice moisture content based on the Weibull distribution and Levenberg-Marquardt(LM)algorithm.Application of the Weibull distribution model was investigated regarding its description of the drying kinetics of milled rice during infrared drying.An adaptive mechanism was applied to algorithm design,with the starting point of the estimation algorithm determined by calculating the drying rate at each measuring point,and the end-point distinguished using a two-level threshold algorithm.The calculated results were then compared with the measured data regarding the infrared drying of milled rice.For milled rice samples varying in moisture content from 14.44%-17.67%(dry basis),the relative error between predicted and observed values ranged 0.0037-0.0589,with a reduction in test time of 50.71%-67.87%.展开更多
High-quality rice flour is the foundation for the production of various rice-based products.Milling is an essential step in obtaining rice flour,during which significant changes occur in the physicochemical and qualit...High-quality rice flour is the foundation for the production of various rice-based products.Milling is an essential step in obtaining rice flour,during which significant changes occur in the physicochemical and quality characteristics of the flour.Although rice flour obtained through mainstream wet milling methods exhibits superior quality,low production efficiency and wastewater discharge limit the development of the industry.Dry milling,on the other hand,conserves water resources,but adversely affects flour performance due to excessive heat generation.As an emerging powder-making technique,semi-dry milling offers a promising solution by enhancing flour quality and reducing environmental impact.This is achieved by minimizing soaking time through hot air treatment while reducing mechanical energy consumption to reach saturated water absorption levels.However,continuous production remains a challenge.This comprehensive review summarizes the effects of various milling technologies on rice flour properties and product qualities.It also discusses key control indicators and technical considerations for rice flour processing equipment and processes.展开更多
Fermentation substrates of rice with different milling degrees(MDs) were prepared and fermented with human feces to compare their fermentation properties and effects on gut microbiota.MD 0s,MD 5s and MD 60s represente...Fermentation substrates of rice with different milling degrees(MDs) were prepared and fermented with human feces to compare their fermentation properties and effects on gut microbiota.MD 0s,MD 5s and MD 60s represented brown rice,moderately-milled rice and white rice,respectively.After in vitro fermentation,the MD 5s group showed higher starch utilization,compared with the MD 0s and 60s groups evaluated by Fourier transform infrared spectrometer,and confocal laser scanning microscope.Effects of fermentation substrates of rice with different MDs on gut microbiota were evaluated by 16S rDNA sequencing.All the sample groups reduced the pH and produced short-chain fatty acids(SCFAs) and branched-chain fatty acids.The MD 5s group exhibited higher α-diversity than the MD 0s and 60s groups.Abundances of Phascolarctobacterium,Blautia and norank_f_Ruminococcaceae were higher in the MD 0s and 5s groups,compared with the MD 60s group.These bacteria were also positively correlated with the SCFAs production via Spearman correlation analysis.In vitro culture assay revealed that fermentation substrates of MD 0s and 5s promoted the growth of two probiotics(Akkermansia muciniphila and Bifidobacterium adolescentis).Our results showed that moderate milling might be an appropriate way to produce rice products with richer nutrients and better fermentation properties.展开更多
The reliable operation of high-speed wire rod finishing mills is crucial in the steel production enterprise.As complex system-level equipment,it is difficult for high-speed wire rod finishing mills to realize fault lo...The reliable operation of high-speed wire rod finishing mills is crucial in the steel production enterprise.As complex system-level equipment,it is difficult for high-speed wire rod finishing mills to realize fault location and real-time monitoring.To solve the above problems,an expert experience and data-driven-based hybrid fault diagnosis method for high-speed wire rod finishing mills is proposed in this paper.First,based on its mechanical structure,time and frequency domain analysis are improved in fault feature extraction.The approach of combining virtual value,peak value with kurtosis value index,is adopted in time domain analysis.Speed adjustment and side frequency analysis are proposed in frequency domain analysis to obtain accurate component characteristic frequency and its corresponding sideband.Then,according to time and frequency domain characteristics,fault location based on expert experience is proposed to get an accurate fault result.Finally,the proposed method is implemented in the equipment intelligent diagnosis system.By taking an equipment fault on site,for example,the effectiveness of the proposed method is illustrated in the system.展开更多
Introduction: Noise is the second leading cause of hearing loss in adults after presbycusis. The objective of this work was to study hearing loss induced by the noise of mills in the markets of Parakou. Methods: This ...Introduction: Noise is the second leading cause of hearing loss in adults after presbycusis. The objective of this work was to study hearing loss induced by the noise of mills in the markets of Parakou. Methods: This was a descriptive and analytical cross-sectional study, conducted from February 3 to June 3, 2021 in the markets of Parakou. It concerned millers and sellers located within a 5 meter radius around the mills and among whom pure-tone audiometry was performed to detect a hearing loss. Subjects with no particular medical health history, under 55 years of age and having been working in these markets since more than 12 months, were included. Results: In this study, 103 subjects were selected, including 43 millers and 61 sellers. Their average age was 29 ± 13 years. The sex ratio was 0.49. The average length of service in the profession was 8 years with the extremes of 3 months and 47 years. They were exposed to noise on average 10 hours per day and 6 days a week. The average duration of weekly noise exposure was 23 h 28 min ± 13 h 32 min with the extremes of 5 h 00 min and 52 h 30 min. The average level of noise exposure was 90 dB with the extremes of 72 and 110 dB. 24 subjects reported symptoms related to noise such as headache, tinnitus, and hearing loss, with respective proportions of 22.33%, 20.39% and 06.80%. The prevalence of noise-related hearing loss was 26.21% (n = 27/103). Subjects with a notch at 4000 Hz and normal Average Hearing Loss (AHL) (20.39%) had a seven-time greater risk of developing noise-induced hearing loss (OR = 6.58;95% CI [2.54 - 18.8], p Conclusion: Hearing loss related to the noise of mills affected both millers and sellers near the mills in markets, hence the importance of regulating mills.展开更多
In this study, aluminum alloy (Al-2 wt% Cu) matrix composites reinforced with 1, 2 and 4 wt% boron carbide nanoparticles fabricated through mechanical milling with average size of 100 nm were fabricated via stir casti...In this study, aluminum alloy (Al-2 wt% Cu) matrix composites reinforced with 1, 2 and 4 wt% boron carbide nanoparticles fabricated through mechanical milling with average size of 100 nm were fabricated via stir casting method at 850℃. Cast ingots of the matrix alloy and the composites were extruded at 500℃ at an extrusion ratio of 10:1 to investigate the effects of hot extrusion on the mechanical properties of the composites. The microstructures of the as-cast and the extruded composites were investigated by scanning electron microscopy (SEM). Density measurement, hardness and tensile tests were carried out to identify the mechanical properties of the composites. The extruded samples revealed a more uniform distribution of B4C nanoparticles. Also, the extruded samples had strength and ductility values superior to those of the as-cast counterparts. In the as-cast and the extruded samples, with increasing amount of B4C nanoparticles, yield strength and tensile strength increased but elongation to fracture decreased.展开更多
文摘The preparation of γ-Fe<sub>2</sub>O<sub>3</sub>/Gd<sub>2</sub>O<sub>3</sub> nanocomposite for possible use in magnetic hyperthermia application was done by ball milling technique. The nanocomposite was characterized by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The heating efficiency and the effect of milling time (5 h and 30 h) on the structural and magnetic properties of the nanocomposite were reported. XRD analysis confirms the formation of the nanocomposite, while magnetization measurements show that the milled sample present hysteresis with low coercivity and remanence. The specific absorption rate (SAR) under an alternating magnetic field is investigated as a function of the milling time. A mean heating efficiency of 68 W/g and 28.7 W/g are obtained for 5 h and 30 h milling times respectively at 332 kHz and 170 Oe. The results showed that the obtained nanocomposite for 5 h milling time is a promising candidate for magnetic hyperthermia due to his properties which show an interesting magnetic behavior and high specific absorption rate.
基金the support from National Key Research and Development Program of China(NO.2016YFD400604-02)the National Natural Science Foundation of China(NO.82003457)+1 种基金Jiangsu Province Science Foundation for Youths(NO.BK20200366)the Fundamental Research Funds for the Central Universities and“Zhishan”Scholars Programs of Southeast University.
文摘Flaxseed has displayed the potential beneficial as functional foods.However,most studies focused on effects of flaxseed extracts or ingredients in flaxseed.Besides,few studies showed that flaxseed extracts contributed to anti-type 1 diabetes(T1D),yet the underlying mechanism is still unknown.In the present study,16.7% of milled flaxseed(MF)-added diet was given to diabetic mice induced by streptozocin for 6 weeks.The results showed that MF feeding 1)slightly decreased blood glucose levels and improved the ability of glucose tolerance by oral glucose tolerance test,2)decreased liver tumor necrosis factor-αlevels and increased liver glycogen levels with significance via down-regulating TLR4/NF-κB pathways,3)and significantly altered some beneficial bacteria in gut microbiota.In conclusion,the present study showed that milled flaxseed showed the potential on anti-T1D through anti-inflammation via TLR4/NF-κB and altering the gut microbiota in STZ-induced diabetic mice.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50872089,61077039 and 61377060the Research Grants Council of the Hong Kong Special Administrative Region of China under Grant No 11211014+1 种基金the Key Program for Research on Fundamental to Application and Leading Technology of Tianjin Science and Technology Commission of China under Grant No 11JCZDJC15500the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 20100032110052
文摘Transmission spectra of triangular lattice photonic crystals milled in the top surface of an annealed protonexchange waveguide are numerically simulated.The effects of the finite depth,conical shape,trapezoidal shape and hybrid shape of holes are theoretically analyzed.Due to the difficulty of milling high aspect-ratio cylindrical holes in lithium niobate(LiNbO_3),a compromised solution is proposed to improve the overlap between shallow holes and the waveguide mode,and useful transmission spectra with strong contrast and sharp band edges are achieved.
文摘<span style="font-family:Verdana;">In work reported here, the dynamic properties and low-velocity impact response of woven carbon/epoxy laminates incorporating a novel 3D interlaminar reinforcement concept with dense layers of Z-axis oriented milled carbon fiber Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> prepregs, are presented. Impulse-frequency response vibration technique is used for non-destructive evaluation of the dynamic flexural modulus (stiffness) and loss factor (intrinsic damping) of woven carbon/epoxy control and Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminates. Low-velocity punch-shear tests were performed on control and Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminates according to ASTM D3763 Standard using a drop-weight impact test system. Control panels had all layers of 3K plain woven carbon/epoxy prepregs, with a dense interlaminar reinforcement of milled carbon fibers in Z-</span><span style="font-family:;" "=""> </span><span><span style="font-family:Verdana;">direction used in designing the Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminate—both having same areal density. Impulse-frequency response vibration experiments show that with a 50% replacement of woven carbon fabric in control panel with milled carbon fibers in Z direction dynamic flexural modulus reduced 25%</span></span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">30% (loss in stiffness) and damping increased by about the same 25%</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">30%. Low-velocity punch-shear tests demonstrated about</span><span style="font-family:;" "=""> </span><span><span style="font-family:Verdana;">25% reduction in energy absorption for Supercomposite</span><sup><span style="font-family:Verdana;">TM</span></sup><span style="font-family:Verdana;"> laminates with the replacement of 50% woven carbon fabric in control panel.</span></span>
基金Supported by Jiangsu Provincial Natural Science Foundation of China(Grant No.BK20141400)National Natural Science Foundation of China(Grant No.51105207)Priority Academic Program Development of Jiangsu Higher Education Institutions of China
文摘The aluminum alloy Al Mn1 Cu has been broadly applied for functional parts production because of its good properties. But few researches about the machining mechanism and the surface roughness were reported. The high-speed milling experiments are carried out in order to improve the machining quality and reveal the machining mechanism. The typical topography features of machined surface are observed by scan electron microscope(SEM). The results show that the milled surface topography is mainly characterized by the plastic shearing deformation surface and material piling zone. The material flows plastically along the end cutting edge of the flat-end milling tool and meanwhile is extruded by the end cutting edge, resulting in that materials partly adhere to the machined surface and form the material piling zone. As the depth of cut and the feed per tooth increase, the plastic flow of materials is strengthened and the machined surface becomes rougher. However, as the cutting speed increases, the plastic flow of materials is weakened and the milled surface becomes smoother. The cutting parameters(e.g. cutting speed, feed per tooth and depth of cut)influencing the surface roughness are analyzed. It can be concluded that the roughness of the machined surface formed by the end cutting edge is less than that by the cylindrical cutting edge when a cylindrical flat-end mill tool is used for milling. The proposed research provides the typical topography features of machined surface of the anti-rust aluminum alloy Al Mn1 Cu in high speed milling.
基金RKG acknowledges the financial support from the National Science Foundation(NSF-CMMI 1846887)under the direction of Dr.Alexis Lewis.
文摘The influence of spark plasma sintering(SPS)temperature on microstructure,hardness and corrosion behavior of a high-energy ball milled Mg-10wt%Al alloy was investigated in this work.The holding time and sintering pressure for SPS were kept constant while varying the sintering temperature from 200 to 350℃.The grain size and microstructure were studied using X-ray diffraction analysis,scanning electron microscopy,energy dispersive X-ray spectroscopy,and Archimedes'based density measurement.Corrosion behavior was investigated using potentiodynamic polarization tests.The nanocrystalline regime(grain size<100nm)was maintained even after SPS up to 350℃.The density of the alloy increased with increasing the SPS temperature.Vickers'hardness and corrosion performance improved up to 300℃ followed by a decrease after SPS at 350℃.Possible reasons for densification,strengthening,and corrosion behavior have been discussed in the light of reduced porosity and microstructural changes.
基金Supported by Shenzhen Municipal Science and Technology Innovation Commission of China(Grant Nos.Y01336107,GJHZ20180411143506667,JCYJ20170817111811303).
文摘The Ti6Al4V parts produced by the existing selective laser melting(SLM)are mainly confronted with poor surface finish and inevitable interior defects,which substantially deteriorates the mechanical properties and performances of the parts.In this regard,ultrasonically-assisted machining(UAM)technique is commonly introduced to improve the machining quality due to its merits in increasing tool life and reducing cutting force.However,most of the previous studies focus on the performance of UAM with ultrasonic vibrations applied in the tangential and feed directions,whereas few of them on the impact of ultrasonic vibration along the vertical direction.In this study,the effects of feed rate on surface integrity in ultrasonically-assisted vertical milling(UAVM)of the Ti6Al4V alloy manufactured by SLM were systemically investigated compared with the conventional machining(CM)method.The results revealed that the milling forces in UAVM showed a lower amplitude than that in CM due to the intermittent cutting style.The surface roughness values of the parts produced by UAVM were generally greater than that by CM owing to the extra sinusoidal vibration textures induced by the milling cutter.Moreover,the extra vertical ultrasonic vibration in UAVM was beneficial to suppressing machining chatter.As feed rate increased,surface microhardness and thickness of the plastic deformation zone in CM raised due to more intensive plastic deformation,while these two material properties in UAVM were reduced owing to the mitigated impact effect by the high-frequency vibration of the milling cutter.Therefore,the improved surface microhardness and reduced thickness of the subsurface deformation layer in UAVM were ascribed to the vertical high-frequency impact of the milling cutter in UAVM.In general,the results of this study provided an in-depth understanding in UAVM of Ti6Al4V parts manufactured by SLM.
文摘Based on analyzing various factors influencing milled surface topography, firstly, a generalized model for milled surface topography is proposed. Secondly, using the principles of transformation matrix and vector operation, the trajectory equation of cutting edge relative to workpiece is derived. Then, a three dimensional topography simulation algorithm is constructed through dividing the workpiece into regular grids. Finally, taking the peripheral milling process as an example, the generalized model is simplified, and the corresponding simulation examples are given. The results indicate that it is very efficient for the generalized model to be used to analyze and simulate the peripherally milled surface topography.
文摘In order to improve the utilization of milling materials,save stone resources and reduce milling energy consumption,the aged Styrene-butadiene-styrene(SBS)modified asphalt was used as a binder to prepare AC-16 asphalt mixture to simulate old asphalt pavement materials.First,the test and discrete element simulation results of uniaxial compression tests were used to calibrate the parameters of the parallel bonding contact model between asphalt mortar and aggregates.On this basis,a microscopic model of the asphalt mixture was established to simulate the old asphalt pavement.Then,the discrete element software PFC(Particle Flow Code)was used to simulate the milling process of the old asphalt pavement.Analyzed the force of the cutting tool and the utilization rate of milling materials,and the optimal milling speed and milling depth were determined.Finally,the energy consumption in the milling process was measured.It is concluded that in the process of milling the old asphalt pavement,using a cutting angle of 42°,milling speed of 0.5 m/s and milling depth of 20 mm can reduce the wear of the cutting tool.In this case,the direct utilization rate of milling materials is 85.3%,and the rate of energy consumption reduction is 33.53%.After parameter optimization,the utilization rate of milling materials can be increased by 17.4%.
基金Funded by the 863 High Technology Research Project ( No.2001AA339020 and 2002AA305302) fromthe Ministry of Scienceand Technology of China ,and bythe Excellent Young Teachers Pro-gramof MOE(2002[350])
文摘The nanostructures of the ball milled FeCo particles were characterized as functions of the ball milling time (t) using quantitative X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) analysis techniques. The results show that the nanocrystalline bcc FeCo particles are available using carbonyl iron and cobalt powders as the start materials during the high-energy ball milling. At the early stage of ball milling, Co powders are easily mashed into nanocrystalllites,by which the surface of the larger Fe particles of about 80-150 nm is coated. With t increasing, the refinement of grain size and the incorporation of defects including dislocations, disclinations and grain boundaries happen, and then FeCo alloy with a certain layered structure is formed, finally the layered structure disappears with the formation of isotropic grains having a steady-state grain size in the nanometer regime after a certain period of t.
基金financially supported by the National Natural Science Foundation of China(Nos.51901105,51871125,and 51761032)Natural Science Foundation of Inner Mongolia,China(2019BS05005)+1 种基金Inner Mongolia University of Science and Technology Innovation Fund(2019QDL-B11)Major Science and Technology Innovation Projects in Shandong Province(2019JZZY010320)
文摘In this investigation,mechanical grinding was applied to fabricating the Mg-based alloys La_(7)Sm_(3)Mg_(80)Ni_(10)+5 wt.%M(M=None,TiO_(2),La_(2)O_(3))(named La_(7)Sm_(3)Mg_(80)Ni_(10)-5 M(M=None,TiO_(2),La_(2)O_(3))).The result reveals that the structures of as-milled alloys consist of amorphous and nanocrystalline.The particle sizes of the added M(M=TiO_(2),La_(2)O_(3))alloys obviously diminish in comparison with the M=None specimen,suggesting that the catalysts TiO_(2)and La_(2)O_(3)can enhance the grinding efficiency.What’s more,the additives TiO_(2)and La_(2)O_(3)observably improve the activation performance and reaction kinetics of the composite.The time required by releasing 3 wt.%hydrogen at553,573 and 593 K is 988,553 and 419 s for the M=None sample,and 578,352 and 286 s for the M=TiO_(2)composite,and 594,366,301 s for the La_(2)O_(3)containing alloy,respectively.The absolute value of hydrogenation enthalpy change|△H|of the M(M=None,TiO_(2),La_(2)O_(3))alloys is 77.13,74.28 and 75.28 kJ/mol.Furthermore,the addition of catalysts reduces the hydrogen desorption activation energy(E_(a)^(de)).
基金Project supported by the Open Research Project of State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilizationthe National Natural Science Foundation of China(Grant Nos.51771197 and 52171187)。
文摘Due to the hydrogen embrittlement effect,La(Fe,Si)_(13)-based hydrides can only exist in powder form,which limits their practical application.In this work,ductile and thermally conductive Al metal was homogeneously mixed with La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)B_(0.2)using the ball milling method.Then hydrogenation and compactness shaping of the magnetocaloric composites were performed in one step via a sintering process under high hydrogen pressure.As the Al content reached 9 wt.%,the La_(0.5)Pr_(0.5)Fe_(11.4)Si_(1.6)B_(0.2)H_(y)/Al composite showed the mechanical behavior of a ductile material with a yield strength of~44 MPa and an ultimate strength of 269 MPa accompanied by a pronounced improvement in thermal conductivity.Due to the ease of formation of Fe-Al-Si phases and the several micron and submicron sizes of the composite particles caused by ball milling process,the magnetic entropy change of the composites was substantially reduced to~1.2 J/kg·K-1.5 J/kg·K at 0 T-1.5 T.
文摘This paper reports a study on nanocrystalline ceria powder prepared by high energy ball-milling and combustion synthesis methods. The combustion synthesis was carried out using ceric ammonium nitrate as oxidizer and citric acid, glycine or citric acid plus glycine as fuel. The minimum crystallite size of ceria powder is obtained by combustion synthesis of ceric ammonium nitrate and citric acid. The ceria powder produced by combustion synthesis of ceric ammonium nitrate and citric acid and glycine has less agglomeration of particles than other techniques.
基金This study supported by a grant from the National Natural Science Foundation of China(No.61663039)Natural Science Foundation of Ningxia Hui Autonomous Region(No.NZ1648)the Natural Science Funds of Ningxia University(ZR15010).
文摘The loss on drying method,which is regarded as the standard method of rice moisture content analysis,provides the most reliable results but is both labor intensive and time consuming.In order to improve the detection efficiency of the loss on drying method,this study investigated the drying characteristics of milled rice and developed an information fusion algorithm with which to predict milled rice moisture content based on the Weibull distribution and Levenberg-Marquardt(LM)algorithm.Application of the Weibull distribution model was investigated regarding its description of the drying kinetics of milled rice during infrared drying.An adaptive mechanism was applied to algorithm design,with the starting point of the estimation algorithm determined by calculating the drying rate at each measuring point,and the end-point distinguished using a two-level threshold algorithm.The calculated results were then compared with the measured data regarding the infrared drying of milled rice.For milled rice samples varying in moisture content from 14.44%-17.67%(dry basis),the relative error between predicted and observed values ranged 0.0037-0.0589,with a reduction in test time of 50.71%-67.87%.
基金supported by the National Natural Science Foundation of China(Grant No.31972005)Xinjiang Uygur Autonomous Region‘Tianshan Talent’Training Plan Project,China(Grant No.2022TSYCCX0063).
文摘High-quality rice flour is the foundation for the production of various rice-based products.Milling is an essential step in obtaining rice flour,during which significant changes occur in the physicochemical and quality characteristics of the flour.Although rice flour obtained through mainstream wet milling methods exhibits superior quality,low production efficiency and wastewater discharge limit the development of the industry.Dry milling,on the other hand,conserves water resources,but adversely affects flour performance due to excessive heat generation.As an emerging powder-making technique,semi-dry milling offers a promising solution by enhancing flour quality and reducing environmental impact.This is achieved by minimizing soaking time through hot air treatment while reducing mechanical energy consumption to reach saturated water absorption levels.However,continuous production remains a challenge.This comprehensive review summarizes the effects of various milling technologies on rice flour properties and product qualities.It also discusses key control indicators and technical considerations for rice flour processing equipment and processes.
基金supported by the National Natural Science Foundation of China (32202051)the Shanghai Sailing Program (21YF1431800, 20YF1433400)+1 种基金Shanghai Agriculture Applied Technology Development Program, China (2021-02-08-0012-F00780 )the National Key R&D Program of China (2022YFF1100104, 2023YFF1103404)。
文摘Fermentation substrates of rice with different milling degrees(MDs) were prepared and fermented with human feces to compare their fermentation properties and effects on gut microbiota.MD 0s,MD 5s and MD 60s represented brown rice,moderately-milled rice and white rice,respectively.After in vitro fermentation,the MD 5s group showed higher starch utilization,compared with the MD 0s and 60s groups evaluated by Fourier transform infrared spectrometer,and confocal laser scanning microscope.Effects of fermentation substrates of rice with different MDs on gut microbiota were evaluated by 16S rDNA sequencing.All the sample groups reduced the pH and produced short-chain fatty acids(SCFAs) and branched-chain fatty acids.The MD 5s group exhibited higher α-diversity than the MD 0s and 60s groups.Abundances of Phascolarctobacterium,Blautia and norank_f_Ruminococcaceae were higher in the MD 0s and 5s groups,compared with the MD 60s group.These bacteria were also positively correlated with the SCFAs production via Spearman correlation analysis.In vitro culture assay revealed that fermentation substrates of MD 0s and 5s promoted the growth of two probiotics(Akkermansia muciniphila and Bifidobacterium adolescentis).Our results showed that moderate milling might be an appropriate way to produce rice products with richer nutrients and better fermentation properties.
基金the National Key Research and Development Program of China under Grant 2021YFB3301300the National Natural Science Foundation of China under Grant 62203213+1 种基金the Natural Science Foundation of Jiangsu Province under Grant BK20220332the Open Project Program of Fujian Provincial Key Laboratory of Intelligent Identification and Control of Complex Dynamic System under Grant 2022A0004.
文摘The reliable operation of high-speed wire rod finishing mills is crucial in the steel production enterprise.As complex system-level equipment,it is difficult for high-speed wire rod finishing mills to realize fault location and real-time monitoring.To solve the above problems,an expert experience and data-driven-based hybrid fault diagnosis method for high-speed wire rod finishing mills is proposed in this paper.First,based on its mechanical structure,time and frequency domain analysis are improved in fault feature extraction.The approach of combining virtual value,peak value with kurtosis value index,is adopted in time domain analysis.Speed adjustment and side frequency analysis are proposed in frequency domain analysis to obtain accurate component characteristic frequency and its corresponding sideband.Then,according to time and frequency domain characteristics,fault location based on expert experience is proposed to get an accurate fault result.Finally,the proposed method is implemented in the equipment intelligent diagnosis system.By taking an equipment fault on site,for example,the effectiveness of the proposed method is illustrated in the system.
文摘Introduction: Noise is the second leading cause of hearing loss in adults after presbycusis. The objective of this work was to study hearing loss induced by the noise of mills in the markets of Parakou. Methods: This was a descriptive and analytical cross-sectional study, conducted from February 3 to June 3, 2021 in the markets of Parakou. It concerned millers and sellers located within a 5 meter radius around the mills and among whom pure-tone audiometry was performed to detect a hearing loss. Subjects with no particular medical health history, under 55 years of age and having been working in these markets since more than 12 months, were included. Results: In this study, 103 subjects were selected, including 43 millers and 61 sellers. Their average age was 29 ± 13 years. The sex ratio was 0.49. The average length of service in the profession was 8 years with the extremes of 3 months and 47 years. They were exposed to noise on average 10 hours per day and 6 days a week. The average duration of weekly noise exposure was 23 h 28 min ± 13 h 32 min with the extremes of 5 h 00 min and 52 h 30 min. The average level of noise exposure was 90 dB with the extremes of 72 and 110 dB. 24 subjects reported symptoms related to noise such as headache, tinnitus, and hearing loss, with respective proportions of 22.33%, 20.39% and 06.80%. The prevalence of noise-related hearing loss was 26.21% (n = 27/103). Subjects with a notch at 4000 Hz and normal Average Hearing Loss (AHL) (20.39%) had a seven-time greater risk of developing noise-induced hearing loss (OR = 6.58;95% CI [2.54 - 18.8], p Conclusion: Hearing loss related to the noise of mills affected both millers and sellers near the mills in markets, hence the importance of regulating mills.
文摘In this study, aluminum alloy (Al-2 wt% Cu) matrix composites reinforced with 1, 2 and 4 wt% boron carbide nanoparticles fabricated through mechanical milling with average size of 100 nm were fabricated via stir casting method at 850℃. Cast ingots of the matrix alloy and the composites were extruded at 500℃ at an extrusion ratio of 10:1 to investigate the effects of hot extrusion on the mechanical properties of the composites. The microstructures of the as-cast and the extruded composites were investigated by scanning electron microscopy (SEM). Density measurement, hardness and tensile tests were carried out to identify the mechanical properties of the composites. The extruded samples revealed a more uniform distribution of B4C nanoparticles. Also, the extruded samples had strength and ductility values superior to those of the as-cast counterparts. In the as-cast and the extruded samples, with increasing amount of B4C nanoparticles, yield strength and tensile strength increased but elongation to fracture decreased.