Objective:To clarify the preferences and core demands of professional Master’s students in Tuina at Yunnan University of Chinese Medicine regarding“concentrated”versus“dispersed”rotation schedules in the Tuina de...Objective:To clarify the preferences and core demands of professional Master’s students in Tuina at Yunnan University of Chinese Medicine regarding“concentrated”versus“dispersed”rotation schedules in the Tuina department,as well as their preferred year for primary rotation,providing evidence for optimizing rotation programs and improving the quality of standardized training.Methods:Paper questionnaires,including two multiple-choice questions and one open-ended question,were distributed to 30 professional Tuina Master’s students,completed on site,and collected immediately.Descriptive statistics were used to analyze preference distributions.Results:A total of 30 questionnaires were distributed and 30 valid responses were collected,achieving a 100%response rate.Among them,23 students(76.7%)supported“concentrated training,”while seven students(23.3%)preferred“dispersed training.”Regarding rotation year preference,18 students(60.0%)selected the second year for concentrated Tuina rotations,eight students(26.7%)selected the third year,and four students(13.3%)selected the first year.The core demands supporting concentrated training were“skill continuity,deep involvement in diagnosis and treatment,and smooth mentorship transition,”whereas those supporting dispersed training were“integration of multi-department knowledge,coordination of research time,and avoidance of fatigue from a single department.”Conclusion:Most professional Tuina Master’s students prefer concentrated Tuina rotations in the second year.It is recommended that institutions adopt a“second-year core department concentrated+auxiliary department flexible dispersed”model and establish flexible coordination and feedback mechanisms to balance clinical skill development with individualized growth needs.展开更多
Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ig...Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ignoring the influence of inlet distortions. This study investigates the mechanism of RI in a transonic rotor through full-annulus unsteady simulations, with a particular focus on the effects of boundary layer ingesting distortions. The results show that at the uniform inflow, the RI fluctuations with the broadband hump can be observed over a relatively wide mass flow rate range, and its origin can be attributed to the coupling effect between the tip leakage flow and shear layer instability. At the inlet distortions, the broadband hump only occurs with partial circumferential locations. This kind of flow phenomenon is defined as Partial Rotating Instability (PRI). The PRI only occurs in a narrower mass flow rate range in which the circumferential range of strong shear is sufficiently large and the self-induced unsteady effects are strong enough. Further, this study confirms that the averaged tip leakage flow axial momentum at the onset of RI or PRI is close, so it can be used as the parameter to determine whether RI or PRI occurs.展开更多
Taking simultaneous variations in both particle volume and density into account, the radial mixing and segregation of binary granular bed in a rotating drum half loaded were investigated by a 3D discrete element metho...Taking simultaneous variations in both particle volume and density into account, the radial mixing and segregation of binary granular bed in a rotating drum half loaded were investigated by a 3D discrete element method. Then, based on the competition theory of condensation and percolation, radial segregation due to differences in particle volume and/or density was analyzed. The results show that if either percolation effect induced by volume difference or condensation effect induced by density difference dominates in the active layer of moving bed, separation will occur. Controlling the volume ratio or density ratio of the two types of particles can achieve an equilibrium state between percolation and condensation, and then homogenous mixture can be obtained. When the percolation balances with the condensation, the relationship between volume ratioand density ratiopresents nearly a power function. Scaling up a rotating drum will not affect the mixing degree of the granular bed so long as the volume ratio and density ratio are predefined.展开更多
We propose a novel cooling protocol within a triple-Laguerre-Gaussian cavity optomechanical system,which is designed to suppress the thermal vibrations of a rotating mirror to reach its quantum ground state.The system...We propose a novel cooling protocol within a triple-Laguerre-Gaussian cavity optomechanical system,which is designed to suppress the thermal vibrations of a rotating mirror to reach its quantum ground state.The system incorporates two auxiliary cavities and an atomic ensemble coupled to a Laguerre-Gaussian rotational cavity.By carefully selecting system parameters,the cooling process of the rotating mirror is significantly enhanced,while the heating process is effectively suppressed,enabling efficient ground-state cooling even in the unresolved sideband regime.Compared to previous works,our scheme reduces the stringent restrictions on auxiliary systems,making it more experimentally feasible under broader parameter conditions.These findings provide a robust approach for achieving ground-state cooling in mechanical resonators.展开更多
[Objectives]To investigate the clinical effects of implementing structured phased rehabilitation training,in addition to conventional rehabilitation,on shoulder joint function and pain alleviation in patients with rot...[Objectives]To investigate the clinical effects of implementing structured phased rehabilitation training,in addition to conventional rehabilitation,on shoulder joint function and pain alleviation in patients with rotator cuff injuries managed conservatively.[Methods]Eighty patients diagnosed with rotator cuff injury were selected and randomly assigned to either the control group or the experimental group,each comprising 40 individuals.The control group received conventional rehabilitation treatment,whereas the experimental group underwent phased rehabilitation training in addition to the conventional treatment for 6 weeks.Assessments were conducted prior to treatment,6 weeks following treatment,and 8 weeks after the completion of treatment(follow-up period).The visual analogue scale(VAS)was employed to evaluate pain intensity,the Constant-Murley score was utilized to assess shoulder joint function,and the shoulder joint range of motion was measured.[Results]Prior to treatment,no statistically significant differences were observed between the two patient groups across all measured indicators(P>0.05).Following 6 weeks of treatment and throughout the follow-up period,both groups exhibited significant reductions in VAS scores compared to baseline measurements,alongside improvements in Constant-Murley scores and shoulder joint range of motion(P<0.05).Furthermore,the magnitude of improvement in the experimental group was significantly greater than that in the control group(P<0.05).[Conclusions]Phased rehabilitation training can enhance shoulder joint function and alleviate pain in patients with rotator cuff injuries beyond the effects of conventional rehabilitation treatment,demonstrating notable clinical application value.展开更多
Frequent shifts of output and operating mode require a pump turbine with excellent stability. Current researches show that large partial flow conditions in pump mode experience positive-slope phenomena with a large he...Frequent shifts of output and operating mode require a pump turbine with excellent stability. Current researches show that large partial flow conditions in pump mode experience positive-slope phenomena with a large head drop. The pressure fluctuation at the positive slope is crucial to the pump turbine unit safety. The operating instabilities at large partial flow conditions for a pump turbine are analyzed. The hydraulic performance of a model pump turbine is tested with the pressure fluctuations measured at unstable operating points near a positive slope in the performance curve. The hydraulic performance tests show that there are two separated positive-slope regions for the pump turbine, with the flow discharge for the first positive slope from 0.85 to 0.91 times that at the maximum efficiency point. The amplitudes of the pressure fluctuations at these unstable large partial flow conditions near the first positive slope are much larger than those at stable operating condtions. A dominant frequency is measured at 0.2 times the impeller rotational frequency in the flow passage near the impeller exit, which is believed to be induced by the rotating stall in the flow passage of the wicket gates. The test results also show hysteresis with pressure fluctuations when the pump turbine is operated near the first positive slope. The hysteresis creates different pressure fluctuations for those operation points even though their flow rates and heads are similar respectively. The pressure fluctuation characteristics at large partial flow conditions obtained by the present study will be helpful for the safe operation of pumped storage units.展开更多
Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant sol...Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties(e.g., high water contact angle of 112°), and improved thermal stability of MH. The limiting oxygen index(LOI) further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.展开更多
The particle mixing was studied in a cylindrical stirred tank with elliptical dished bottom by experiments and simulations.The impeller types used were double helical ribbon(HR) + bottom HR,pitched blade ribbon + bott...The particle mixing was studied in a cylindrical stirred tank with elliptical dished bottom by experiments and simulations.The impeller types used were double helical ribbon(HR) + bottom HR,pitched blade ribbon + bottom HR,inner and outer HR + bottom HR,and pitched blade ribbon + Pfaudler + bottom HR labeled as impellers Ⅰ to Ⅳ,respectively.The quantitative correlations among the rotational speed,fill level and power consumption for impeller Ⅰ and impeller Ⅱ were obtained by experiments to validate the discrete element method(DEM) simulations.The particle mixing at different operating conditions was simulated via DEM simulations to calculate the mixing index using the Lacey method,which is a statistical method to provide a mathematical understanding of the mixing state in a binary mixture.The simulation results reveal that as the rotational speed increases,the final mixing index increases,and as the fill level increases,the final mixing index decreases.At the same operating conditions,impeller Ⅲ is the optimal combination,which provides the highest mixing index at the same revolutions.展开更多
Copper（ Ⅱ ） resercyiic acid（CuRes） nanoparticles were synthesized by using reactive precipitation method with resorcylic acid and blue copperas as the raw material in a rotating packed bed. The sample obtained wa...Copper（ Ⅱ ） resercyiic acid（CuRes） nanoparticles were synthesized by using reactive precipitation method with resorcylic acid and blue copperas as the raw material in a rotating packed bed. The sample obtained was characterized by using X-ray diffraction（XRD）, transmission electron micrescopy（TEM）, Fourier transform infrared spectroscopy （FTIR）, thermo-gravimetric analyses （TG）, and element analysis. In addition, the catalytic activity of CuRes nanoparticles on the thermal decomposition of nitrocellulose-nitroglycerine（NC-NG） was also determined via DSC. The results show that the spherical nanoparticles with a diameter of 20 nm were obtained in ethanol solution. The peak temperature of the thermal decomposition of NC-NG-CuRes decreases by 3℃ compared with that of normal CuRes, and the decomposition enthalpy is increased by 735 J/g, and therefore, it is reasonable to assume that CuRes nanoparticles have a better catalytic activity.展开更多
Green manure–crop rotation is a sustainable approach to protect crops against diseases and improve yield.However,the mechanism by which green manuring manipulates the crop-associated microbial community remains to be...Green manure–crop rotation is a sustainable approach to protect crops against diseases and improve yield.However,the mechanism by which green manuring manipulates the crop-associated microbial community remains to be elucidated.In this study,we explored the horizontal processes of bacterial communities in different compartments of the soil–root interface(bulk soil,rhizosphere soil,rhizoplane and endosphere)of tobacco by performing a field experiment including four rotation practices,namely,tobacco rotated with smooth vetch,ryegrass,radish,and winter fallow(without green manure).Results showed that the co-occurrence networks constructed by adjacent compartments of the soil–root interface with green manuring had more edges than without green manuring,indicating dramatic microbial interactions.Green manuring increased the dispersal-niche continuum index between bulk soil and other compartments,indicating that it facilitated the horizontal dispersal of microbes.For the different green manuring practices,the neutral community model explained 24.6–27.6%of detection frequency for bacteria,and at least one compartment under each practice had a normalized stochasticity ratio higher than the 50%boundary point,suggesting that the deterministic and stochastic processes jointly shaped the tobacco microbiome.In conclusion,green manuring generally facilitates bacterial community dispersal across different compartments and enhances potential interactions among adjacent compartments.This study provides empirical evidence for understanding the microbiome assembly under green manure–crop rotation.展开更多
The rotational motions of the optically trapped microscopic particles by the vortex femtosecond laser beam are investigated in this paper.Black particles can be trapped and rotated by a vortex femtosecond laser beam v...The rotational motions of the optically trapped microscopic particles by the vortex femtosecond laser beam are investigated in this paper.Black particles can be trapped and rotated by a vortex femtosecond laser beam very effectively because the vortex beam carries orbital angular momentum due to the helical wave-front structure in assoication with the central phase singularity.Trapped black particles rotate in the vortex beam due to the absorption of the angular momentum transferred from the vortex beam.The rotating directions of the trapped particles can be modulated by reversing the topological charge of the optical vortex in the vortex femtosecond beam.And the rotating speeds of the trapped microscopic particles greatly depend on the topological charges of the vortex tweezer and the used pulse energies.展开更多
Fabrication of superior catalytic performance palladium-based catalysts with affordable cost is the key to develop direct ethanol fuel cell.Herein,Pd-decorated three-dimensional(3D)porous constructed from graphene oxi...Fabrication of superior catalytic performance palladium-based catalysts with affordable cost is the key to develop direct ethanol fuel cell.Herein,Pd-decorated three-dimensional(3D)porous constructed from graphene oxide(GO)and MXene combining with polystyrene(PS)particles as sacrificial templates(Pd/GO-MXene-PS)to elevate the catalytic performance for ethanol oxidation was proposed.The 3D porous interconnected structure of Pd/GO-MXene-PS was characterized by scanning electron microscope(SEM),transmission electron microscope(TEM)and Brunner−Emmet−Teller(BET).By optimizing the doping ratio of MXene to GO,the mass activity of Pd/GO_(5)-MXene_(5)-PS(2944.0 mA·mg^(−1))was 3.0 times higher than that of commercial Pd/C(950.4 mA·mg^(−1))toward ethanol oxidation in base solution.Meanwhile,the rotating disk electrode(RDE)results demonstrated that Pd/GO5-MXene5-PS had a faster kinetics of ethanol oxidation.The enhanced ethanol oxidation over Pd/GO5-MXene5-PS could attribute to the excellent 3D interconnected porous structure,large surface area,good conductivity and homogeneous Pd distribution.This work provided a new idea for creating 3D porous MXene composite materials in electrocatalysis.展开更多
Diluted ferromagnetic semiconductors（DMSs） that combine the properties of semiconductors with ferromagnetism have potential application in spin-sensitive electronic（spintronic） devices. The search for DMS material...Diluted ferromagnetic semiconductors（DMSs） that combine the properties of semiconductors with ferromagnetism have potential application in spin-sensitive electronic（spintronic） devices. The search for DMS materials exploded after the observation of ferromagnetic ordering in Ⅲ-Ⅴ（Ga,Mn）As films. Recently, a series of DMS compounds isostructural to iron-based superconductors have been reported. Among them, the highest Curie temperature TCo f 230 K has been achieved in（Ba,K）（Zn,Mn）2As2. However, most DMSs, including（Ga,Mn）As, are p-type, i.e., the carriers that mediate the ferromagnetism are holes. For practical applications, DMSs with n-type carriers are also advantageous. Very recently,a new DMS Ba（Zn,Co）2As2 with n-type carriers has been synthesized. Here we summarize the recent progress on this research stream. We will show that the homogeneous ferromagnetism in these bulk form DMSs has been confirmed by microscopic techniques, i.e., nuclear magnetic resonance（NMR） and muon spin rotation（μSR）.展开更多
The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-solvent precipitation （HGAP） process. Intensified micromixing and uniform nucl...The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-solvent precipitation （HGAP） process. Intensified micromixing and uniform nucleation environment are created by the high-gravity equipment （rotating packed bed） in carrying out the anti-solvent precipitation process to produce nanoparticles. The average particle size decreases from 55 μm of the raw danazol to 190 nm of the nanoparticles. The Brunauer-Emmett-Teller （BET） surface area sharply increases from 0.66 m^2·g^-1 to 15.08 m^2·g^-l. Accordingly, the dissolution rate is greatly improved. The molecular state, chemical composition, and crystal form of the danazol nanoparticles remains unchanged after processing according to Fourier transform infrared （FTIR） and X-ray diffraction （XRD）, The high recovery ratio and continuous production capacity are highly appreciated in industry. Therefore, the HGAP method might offer a general and facile platform for mass production of hydrophobic pharmaceutical danazol particles in nanometer range.展开更多
Partial surge is a type of instability inception in transonic compressors and occurs in the form of axisymmetric low-frequency disturbances localized in the hub region.Previous studies illustrate that the frequency of...Partial surge is a type of instability inception in transonic compressors and occurs in the form of axisymmetric low-frequency disturbances localized in the hub region.Previous studies illustrate that the frequency of partial surge is set by the Helmholtz frequency of the entire system,which motivates to propose a hypothesis that the system response performs an important role in the formation of partial surge.For further verification,a series of experiments are conducted to explore the link between the propagating of the partial surge and the system feedback in this study.In the first case,an additional test point is set on the wall of the plenum to detect the system response.Combining the flow behaviors inside the plenum with the disturbances in the rotor tip and stator hub/tip regions,the effects of the system feedback on the occurrence of the continuous disturbances and the rotating stall cells are illustrated.In the second case,a screen is mounted at the compressor outlet to prevent positive feedback from the plenum.The experimental results demonstrate that in the absence of system feedback,it is the occurrence of spike-type stall inception that leads to the flow instability instead of that of partial surge.In addition,three flow phenomena in the second case are discussed,including the occurrence of the single pulse,the unstable process during the stall evolution and the switch of instability inception.展开更多
This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a l...This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a lab scale thickener for dewatering of tailing in the flotation circuit.Four thickener operating variables,namely feed flowrate,solid percent,flocculant dosage and feedwell height were changed during the tests based on CCRD.The ranges of values of the thickener variables used in the design were a feed flowrate of 9–21 L/min,solid percent of 8%–20%,flocculant dosage of 1.25–4.25 g/t and feedwell height of 16–26 cm.A total of 30 thickening tests were conducted using lab scale thickener on flotation tailing obtained from the Sarcheshmeh copper mine,Iran.The underflow solid percent and bed height were expressed as functions of four operating parameters of thickener.Predicted values were found to be in good agreement with experimental values(R2values of 0.992 and 0.997 for underflow solid percent and bed height,respectively).This study has shown that the RSM and CCRD could effciently be applied for the modeling of thickener for dewatering of flotation tailing.展开更多
This study investigates the effect of magnetic nanoparticles(NPs) on the weakly polar nematic liquid crystal(NLC).Different parameters of dielectric data were measured for both the homeotropic and planar aligned sampl...This study investigates the effect of magnetic nanoparticles(NPs) on the weakly polar nematic liquid crystal(NLC).Different parameters of dielectric data were measured for both the homeotropic and planar aligned samples as a function of frequency and temperature and the substantial changes have been noticed for the doped systems. Dielectric permittivity has been increased after the dispersion of magnetic NPs in the pure NLC. Dielectric anisotropy has also been influenced by incorporating the magnetic NPs with the NLC molecules. These results were attributed to the dipole–dipole interaction between the magnetic nanoparticles and nematic liquid crystal molecules. Electro-optical study indicated the faster rise time and fall time of the doped systems as compare to pure NLC. Threshold voltage has been calculated and found to be decreased for the doped systems. Moreover, we have also calculated the rotational viscosity and the splay elastic constant for pure and the doped systems. Both the rotational viscosity and splay elastic constant of the doped systems are found to be considerably lower than those of pure NLC. Change in these properties has been explained on the basis of molecular disturbances created by the interaction between the magnetic nanoparticle and LC director. This study reveals that the inclusion of magnetic NPs in weakly polar NLC can be useful to enhance the basic properties of the weakly polar NLC and make it a promising material for many display applications.展开更多
This study investigates the effect of tool rotational speed(TRS)on particle distribution in nugget zone(NZ)through quantitative approach and its consequences on the mechanical property of friction stir welded joints o...This study investigates the effect of tool rotational speed(TRS)on particle distribution in nugget zone(NZ)through quantitative approach and its consequences on the mechanical property of friction stir welded joints of AA6092/17.5 SiCp-T6 composite.6 mm thick plates are welded at a constant tool tilt angle of 2°and tool traverse speed of 1 mm/s by varying the TRS at 1000 rpm,1500 rpm and 2000 rpm with a taper pin profiled tool.Microstructure analysis shows large quantity of uniformly shaped smaller size SiC particle with lower average particle area which are homogeneously distributed in the NZ.The fragmentation of bigger size particles has been observed because of abrading action of the hard tool and resulting shearing effect and severe stress generation due to the rotation of tool.The particles occupy maximum area in the matrix compared to that of the base material(BM)due to the redistribution of broken particles as an effect of TRS.The migration of particles towards the TMAZ-NZ transition zone has been also encountered at higher TRS(2000 rpm).The microhardness analysis depicts variation in average hardness from top to bottom of the NZ,minimum for 1500 rpm and maximum for 2000 rpm.The impact strength at 1000 rpm and 1500 rpm remains close to that of BM(21.6 J)while 2000 rpm shows the accountable reduction.The maximum joint efficiency has been achieved at 1500 rpm(84%)and minimum at 1000 rpm(68%)under tensile loading.Fractographic analysis shows mixed mode of failure for BM,1000 rpm and 1500 rpm,whereas 2000 rpm shows the brittle mode of failure.展开更多
For the bell-less top blast furnace, when particles move along the chute, the particlesr motion direction and the frictional force acting on them will change due to the chute rotation, which consequently influences th...For the bell-less top blast furnace, when particles move along the chute, the particlesr motion direction and the frictional force acting on them will change due to the chute rotation, which consequently influences the velocity at the tip of chute, changes the burden flow width and impact point, and finally affects the stock profile and gas f[ow distribution. So the influence of chute rotation needs to be considered when calculating the burden trajectory with a mathematical model. The mathematical model was established to analyze the influence of Coriolis force on particle velocity at chute tip as well as height and width of burden flow in chute, and to summarize the effect of Coriolis force on burden distribution, thereby making the calculation result more accurate.展开更多
A two-pass annealing/quenching internal spinning process with small-end rotations is proposed to form a curved generatrix conical thin-walled shell.That is,annealing at 360°C for 2 h followed by the 1st pass spin...A two-pass annealing/quenching internal spinning process with small-end rotations is proposed to form a curved generatrix conical thin-walled shell.That is,annealing at 360°C for 2 h followed by the 1st pass spinning,and finally quenching in ice water after holding for 1 h at 498°C followed by the 2nd pass spinning.ABAQUS finite element software is used to simulate the internal spinning process of the products formed under different forming parameters.The distribution laws of spinning force,the stress and strain under different forming processes were compared and analyzed.The mechanical properties and microstructure of the products are subsequently analyzed.The results show that the strain and the residual stress in the skin area of the formed products under two-pass spinning process more uniform,and the hardness and the mechanical performance are improved.The microstructure of the products formed with the 0.15 mm thickness reduction at the 2nd pass is excellent.And the second phase grain size distributed uniformly in the range of 36μm.Whereas,the second phase particles are broken seriously and the size distribution inhomogeneity is increased when the thickness reduction in the skin area is greater than 0.20 mm at the 2nd pass spinning process.展开更多
文摘Objective:To clarify the preferences and core demands of professional Master’s students in Tuina at Yunnan University of Chinese Medicine regarding“concentrated”versus“dispersed”rotation schedules in the Tuina department,as well as their preferred year for primary rotation,providing evidence for optimizing rotation programs and improving the quality of standardized training.Methods:Paper questionnaires,including two multiple-choice questions and one open-ended question,were distributed to 30 professional Tuina Master’s students,completed on site,and collected immediately.Descriptive statistics were used to analyze preference distributions.Results:A total of 30 questionnaires were distributed and 30 valid responses were collected,achieving a 100%response rate.Among them,23 students(76.7%)supported“concentrated training,”while seven students(23.3%)preferred“dispersed training.”Regarding rotation year preference,18 students(60.0%)selected the second year for concentrated Tuina rotations,eight students(26.7%)selected the third year,and four students(13.3%)selected the first year.The core demands supporting concentrated training were“skill continuity,deep involvement in diagnosis and treatment,and smooth mentorship transition,”whereas those supporting dispersed training were“integration of multi-department knowledge,coordination of research time,and avoidance of fatigue from a single department.”Conclusion:Most professional Tuina Master’s students prefer concentrated Tuina rotations in the second year.It is recommended that institutions adopt a“second-year core department concentrated+auxiliary department flexible dispersed”model and establish flexible coordination and feedback mechanisms to balance clinical skill development with individualized growth needs.
基金supports of the National Natural Science Foundation of China(Nos.52076129,92360308,52376027)the Shanghai Municipal Education Commission of China(No.2023-02-4)+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe United Innovation Center(UIC)of Aerothermal Technologies for Turbomachinery of China.
文摘Rotating Instability (RI) is a typical unsteady flow phenomenon in compressors and may cause severe aerodynamic noise and even potential nonsynchronous vibration. Most studies of RI are based on the uniform inflow, ignoring the influence of inlet distortions. This study investigates the mechanism of RI in a transonic rotor through full-annulus unsteady simulations, with a particular focus on the effects of boundary layer ingesting distortions. The results show that at the uniform inflow, the RI fluctuations with the broadband hump can be observed over a relatively wide mass flow rate range, and its origin can be attributed to the coupling effect between the tip leakage flow and shear layer instability. At the inlet distortions, the broadband hump only occurs with partial circumferential locations. This kind of flow phenomenon is defined as Partial Rotating Instability (PRI). The PRI only occurs in a narrower mass flow rate range in which the circumferential range of strong shear is sufficiently large and the self-induced unsteady effects are strong enough. Further, this study confirms that the averaged tip leakage flow axial momentum at the onset of RI or PRI is close, so it can be used as the parameter to determine whether RI or PRI occurs.
基金Projects(5137424151275531)supported by the National Natural Science Foundation of ChinaProject(CX2014B059)supported by the Innovation Foundation for Postgraduate of Hunan Province,China
文摘Taking simultaneous variations in both particle volume and density into account, the radial mixing and segregation of binary granular bed in a rotating drum half loaded were investigated by a 3D discrete element method. Then, based on the competition theory of condensation and percolation, radial segregation due to differences in particle volume and/or density was analyzed. The results show that if either percolation effect induced by volume difference or condensation effect induced by density difference dominates in the active layer of moving bed, separation will occur. Controlling the volume ratio or density ratio of the two types of particles can achieve an equilibrium state between percolation and condensation, and then homogenous mixture can be obtained. When the percolation balances with the condensation, the relationship between volume ratioand density ratiopresents nearly a power function. Scaling up a rotating drum will not affect the mixing degree of the granular bed so long as the volume ratio and density ratio are predefined.
基金Project supported by the National Natural Science Foundation of China(Grant No.62471180)。
文摘We propose a novel cooling protocol within a triple-Laguerre-Gaussian cavity optomechanical system,which is designed to suppress the thermal vibrations of a rotating mirror to reach its quantum ground state.The system incorporates two auxiliary cavities and an atomic ensemble coupled to a Laguerre-Gaussian rotational cavity.By carefully selecting system parameters,the cooling process of the rotating mirror is significantly enhanced,while the heating process is effectively suppressed,enabling efficient ground-state cooling even in the unresolved sideband regime.Compared to previous works,our scheme reduces the stringent restrictions on auxiliary systems,making it more experimentally feasible under broader parameter conditions.These findings provide a robust approach for achieving ground-state cooling in mechanical resonators.
文摘[Objectives]To investigate the clinical effects of implementing structured phased rehabilitation training,in addition to conventional rehabilitation,on shoulder joint function and pain alleviation in patients with rotator cuff injuries managed conservatively.[Methods]Eighty patients diagnosed with rotator cuff injury were selected and randomly assigned to either the control group or the experimental group,each comprising 40 individuals.The control group received conventional rehabilitation treatment,whereas the experimental group underwent phased rehabilitation training in addition to the conventional treatment for 6 weeks.Assessments were conducted prior to treatment,6 weeks following treatment,and 8 weeks after the completion of treatment(follow-up period).The visual analogue scale(VAS)was employed to evaluate pain intensity,the Constant-Murley score was utilized to assess shoulder joint function,and the shoulder joint range of motion was measured.[Results]Prior to treatment,no statistically significant differences were observed between the two patient groups across all measured indicators(P>0.05).Following 6 weeks of treatment and throughout the follow-up period,both groups exhibited significant reductions in VAS scores compared to baseline measurements,alongside improvements in Constant-Murley scores and shoulder joint range of motion(P<0.05).Furthermore,the magnitude of improvement in the experimental group was significantly greater than that in the control group(P<0.05).[Conclusions]Phased rehabilitation training can enhance shoulder joint function and alleviate pain in patients with rotator cuff injuries beyond the effects of conventional rehabilitation treatment,demonstrating notable clinical application value.
基金supported by National Natural Science Foundation of China(Grant No. 50976061)State Key Laboratory of Hydroscience and Engineering of China(Grant No. 2010-ZY-4)Beijing Municipal Natural Science Foundation of China(Grant No. 3072008)
文摘Frequent shifts of output and operating mode require a pump turbine with excellent stability. Current researches show that large partial flow conditions in pump mode experience positive-slope phenomena with a large head drop. The pressure fluctuation at the positive slope is crucial to the pump turbine unit safety. The operating instabilities at large partial flow conditions for a pump turbine are analyzed. The hydraulic performance of a model pump turbine is tested with the pressure fluctuations measured at unstable operating points near a positive slope in the performance curve. The hydraulic performance tests show that there are two separated positive-slope regions for the pump turbine, with the flow discharge for the first positive slope from 0.85 to 0.91 times that at the maximum efficiency point. The amplitudes of the pressure fluctuations at these unstable large partial flow conditions near the first positive slope are much larger than those at stable operating condtions. A dominant frequency is measured at 0.2 times the impeller rotational frequency in the flow passage near the impeller exit, which is believed to be induced by the rotating stall in the flow passage of the wicket gates. The test results also show hysteresis with pressure fluctuations when the pump turbine is operated near the first positive slope. The hysteresis creates different pressure fluctuations for those operation points even though their flow rates and heads are similar respectively. The pressure fluctuation characteristics at large partial flow conditions obtained by the present study will be helpful for the safe operation of pumped storage units.
基金Supported by the National Natural Science Foundation of China(21376229)the Science and Technology of Shanxi Province(2015031019-5)the Natural Science Foundation for Young Scientists of Shanxi Province(2015021033)
文摘Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties(e.g., high water contact angle of 112°), and improved thermal stability of MH. The limiting oxygen index(LOI) further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.
文摘The particle mixing was studied in a cylindrical stirred tank with elliptical dished bottom by experiments and simulations.The impeller types used were double helical ribbon(HR) + bottom HR,pitched blade ribbon + bottom HR,inner and outer HR + bottom HR,and pitched blade ribbon + Pfaudler + bottom HR labeled as impellers Ⅰ to Ⅳ,respectively.The quantitative correlations among the rotational speed,fill level and power consumption for impeller Ⅰ and impeller Ⅱ were obtained by experiments to validate the discrete element method(DEM) simulations.The particle mixing at different operating conditions was simulated via DEM simulations to calculate the mixing index using the Lacey method,which is a statistical method to provide a mathematical understanding of the mixing state in a binary mixture.The simulation results reveal that as the rotational speed increases,the final mixing index increases,and as the fill level increases,the final mixing index decreases.At the same operating conditions,impeller Ⅲ is the optimal combination,which provides the highest mixing index at the same revolutions.
基金the National Natural Science Foundation of China(No 20576128)partially supported by the Natural ScienceFoundation of Shanxi Province(No 20051015)
文摘Copper（ Ⅱ ） resercyiic acid（CuRes） nanoparticles were synthesized by using reactive precipitation method with resorcylic acid and blue copperas as the raw material in a rotating packed bed. The sample obtained was characterized by using X-ray diffraction（XRD）, transmission electron micrescopy（TEM）, Fourier transform infrared spectroscopy （FTIR）, thermo-gravimetric analyses （TG）, and element analysis. In addition, the catalytic activity of CuRes nanoparticles on the thermal decomposition of nitrocellulose-nitroglycerine（NC-NG） was also determined via DSC. The results show that the spherical nanoparticles with a diameter of 20 nm were obtained in ethanol solution. The peak temperature of the thermal decomposition of NC-NG-CuRes decreases by 3℃ compared with that of normal CuRes, and the decomposition enthalpy is increased by 735 J/g, and therefore, it is reasonable to assume that CuRes nanoparticles have a better catalytic activity.
基金supported financially by the National Key Research and Development Program of China(2021YFD1700200)the China Agriculture Research System of MOF and MARA(CARS-22).
文摘Green manure–crop rotation is a sustainable approach to protect crops against diseases and improve yield.However,the mechanism by which green manuring manipulates the crop-associated microbial community remains to be elucidated.In this study,we explored the horizontal processes of bacterial communities in different compartments of the soil–root interface(bulk soil,rhizosphere soil,rhizoplane and endosphere)of tobacco by performing a field experiment including four rotation practices,namely,tobacco rotated with smooth vetch,ryegrass,radish,and winter fallow(without green manure).Results showed that the co-occurrence networks constructed by adjacent compartments of the soil–root interface with green manuring had more edges than without green manuring,indicating dramatic microbial interactions.Green manuring increased the dispersal-niche continuum index between bulk soil and other compartments,indicating that it facilitated the horizontal dispersal of microbes.For the different green manuring practices,the neutral community model explained 24.6–27.6%of detection frequency for bacteria,and at least one compartment under each practice had a normalized stochasticity ratio higher than the 50%boundary point,suggesting that the deterministic and stochastic processes jointly shaped the tobacco microbiome.In conclusion,green manuring generally facilitates bacterial community dispersal across different compartments and enhances potential interactions among adjacent compartments.This study provides empirical evidence for understanding the microbiome assembly under green manure–crop rotation.
基金Project supported by the National Natural Science Foundation for Post-Doctoral Scientists of China (Grant No. 2012M511002)the National Natural Science Foundation of China (Grant Nos. 10904027 and 61108018)the Science and Technology Programs of Heilongjiang Educational Committee,China (Grant No. 12511425)
文摘The rotational motions of the optically trapped microscopic particles by the vortex femtosecond laser beam are investigated in this paper.Black particles can be trapped and rotated by a vortex femtosecond laser beam very effectively because the vortex beam carries orbital angular momentum due to the helical wave-front structure in assoication with the central phase singularity.Trapped black particles rotate in the vortex beam due to the absorption of the angular momentum transferred from the vortex beam.The rotating directions of the trapped particles can be modulated by reversing the topological charge of the optical vortex in the vortex femtosecond beam.And the rotating speeds of the trapped microscopic particles greatly depend on the topological charges of the vortex tweezer and the used pulse energies.
基金financially supported by the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(No.A30B191410)the Sailing Project from Science and Technology Commission of Shanghai Municipality(No.17YF1406600)+6 种基金Chenguang Project Supported by Shanghai Municipal Education Commission(No.18CG68)Gaoyuan Discipline of Shanghai-Materials Science and Engineering(No.A30NH221903)the Open Project of Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices(Soochow University)(No.KS2022)Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devicesthe Project of Guangdong Provincial Education(No.2020KTSCX131)。
文摘Fabrication of superior catalytic performance palladium-based catalysts with affordable cost is the key to develop direct ethanol fuel cell.Herein,Pd-decorated three-dimensional(3D)porous constructed from graphene oxide(GO)and MXene combining with polystyrene(PS)particles as sacrificial templates(Pd/GO-MXene-PS)to elevate the catalytic performance for ethanol oxidation was proposed.The 3D porous interconnected structure of Pd/GO-MXene-PS was characterized by scanning electron microscope(SEM),transmission electron microscope(TEM)and Brunner−Emmet−Teller(BET).By optimizing the doping ratio of MXene to GO,the mass activity of Pd/GO_(5)-MXene_(5)-PS(2944.0 mA·mg^(−1))was 3.0 times higher than that of commercial Pd/C(950.4 mA·mg^(−1))toward ethanol oxidation in base solution.Meanwhile,the rotating disk electrode(RDE)results demonstrated that Pd/GO5-MXene5-PS had a faster kinetics of ethanol oxidation.The enhanced ethanol oxidation over Pd/GO5-MXene5-PS could attribute to the excellent 3D interconnected porous structure,large surface area,good conductivity and homogeneous Pd distribution.This work provided a new idea for creating 3D porous MXene composite materials in electrocatalysis.
基金Project supported by the Chinese Ministry of Science and Technology(Grant No.2016YFA0300402)the National Natural Science Foundation of China(Grant No.11574265)+1 种基金the Natural Science Foundation of Zhejiang Province,China(Grant Nos.LR15A040001 and LY14A040007)the Fundamental Research Funds for the Central Universities,China
文摘Diluted ferromagnetic semiconductors（DMSs） that combine the properties of semiconductors with ferromagnetism have potential application in spin-sensitive electronic（spintronic） devices. The search for DMS materials exploded after the observation of ferromagnetic ordering in Ⅲ-Ⅴ（Ga,Mn）As films. Recently, a series of DMS compounds isostructural to iron-based superconductors have been reported. Among them, the highest Curie temperature TCo f 230 K has been achieved in（Ba,K）（Zn,Mn）2As2. However, most DMSs, including（Ga,Mn）As, are p-type, i.e., the carriers that mediate the ferromagnetism are holes. For practical applications, DMSs with n-type carriers are also advantageous. Very recently,a new DMS Ba（Zn,Co）2As2 with n-type carriers has been synthesized. Here we summarize the recent progress on this research stream. We will show that the homogeneous ferromagnetism in these bulk form DMSs has been confirmed by microscopic techniques, i.e., nuclear magnetic resonance（NMR） and muon spin rotation（μSR）.
基金Supported by the National High Technology Research and Development Program of China (2006AA030202)the Talent Training Program of Beijing (2007B022)
文摘The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-solvent precipitation （HGAP） process. Intensified micromixing and uniform nucleation environment are created by the high-gravity equipment （rotating packed bed） in carrying out the anti-solvent precipitation process to produce nanoparticles. The average particle size decreases from 55 μm of the raw danazol to 190 nm of the nanoparticles. The Brunauer-Emmett-Teller （BET） surface area sharply increases from 0.66 m^2·g^-1 to 15.08 m^2·g^-l. Accordingly, the dissolution rate is greatly improved. The molecular state, chemical composition, and crystal form of the danazol nanoparticles remains unchanged after processing according to Fourier transform infrared （FTIR） and X-ray diffraction （XRD）, The high recovery ratio and continuous production capacity are highly appreciated in industry. Therefore, the HGAP method might offer a general and facile platform for mass production of hydrophobic pharmaceutical danazol particles in nanometer range.
基金the support of National Natural Science Foundation of China(Nos.51706008,51636001,51976005 and 52006002)National Science and Technology Major Project,China(No.2017-Ⅱ-0005-0018)Aeronautics Power Foundation,China(No.6141B09050375)。
文摘Partial surge is a type of instability inception in transonic compressors and occurs in the form of axisymmetric low-frequency disturbances localized in the hub region.Previous studies illustrate that the frequency of partial surge is set by the Helmholtz frequency of the entire system,which motivates to propose a hypothesis that the system response performs an important role in the formation of partial surge.For further verification,a series of experiments are conducted to explore the link between the propagating of the partial surge and the system feedback in this study.In the first case,an additional test point is set on the wall of the plenum to detect the system response.Combining the flow behaviors inside the plenum with the disturbances in the rotor tip and stator hub/tip regions,the effects of the system feedback on the occurrence of the continuous disturbances and the rotating stall cells are illustrated.In the second case,a screen is mounted at the compressor outlet to prevent positive feedback from the plenum.The experimental results demonstrate that in the absence of system feedback,it is the occurrence of spike-type stall inception that leads to the flow instability instead of that of partial surge.In addition,three flow phenomena in the second case are discussed,including the occurrence of the single pulse,the unstable process during the stall evolution and the switch of instability inception.
基金supported by the National Iranian Copper Industry Co.
文摘This study discussed the application of response surface methodology(RSM)and central composite rotatable design(CCRD)for modeling and optimization of the influence of some operating variables on the performance of a lab scale thickener for dewatering of tailing in the flotation circuit.Four thickener operating variables,namely feed flowrate,solid percent,flocculant dosage and feedwell height were changed during the tests based on CCRD.The ranges of values of the thickener variables used in the design were a feed flowrate of 9–21 L/min,solid percent of 8%–20%,flocculant dosage of 1.25–4.25 g/t and feedwell height of 16–26 cm.A total of 30 thickening tests were conducted using lab scale thickener on flotation tailing obtained from the Sarcheshmeh copper mine,Iran.The underflow solid percent and bed height were expressed as functions of four operating parameters of thickener.Predicted values were found to be in good agreement with experimental values(R2values of 0.992 and 0.997 for underflow solid percent and bed height,respectively).This study has shown that the RSM and CCRD could effciently be applied for the modeling of thickener for dewatering of flotation tailing.
文摘This study investigates the effect of magnetic nanoparticles(NPs) on the weakly polar nematic liquid crystal(NLC).Different parameters of dielectric data were measured for both the homeotropic and planar aligned samples as a function of frequency and temperature and the substantial changes have been noticed for the doped systems. Dielectric permittivity has been increased after the dispersion of magnetic NPs in the pure NLC. Dielectric anisotropy has also been influenced by incorporating the magnetic NPs with the NLC molecules. These results were attributed to the dipole–dipole interaction between the magnetic nanoparticles and nematic liquid crystal molecules. Electro-optical study indicated the faster rise time and fall time of the doped systems as compare to pure NLC. Threshold voltage has been calculated and found to be decreased for the doped systems. Moreover, we have also calculated the rotational viscosity and the splay elastic constant for pure and the doped systems. Both the rotational viscosity and splay elastic constant of the doped systems are found to be considerably lower than those of pure NLC. Change in these properties has been explained on the basis of molecular disturbances created by the interaction between the magnetic nanoparticle and LC director. This study reveals that the inclusion of magnetic NPs in weakly polar NLC can be useful to enhance the basic properties of the weakly polar NLC and make it a promising material for many display applications.
基金Ministry of Human Resource,Government of India for providing necessary funding through scholarship to carry out the research activities。
文摘This study investigates the effect of tool rotational speed(TRS)on particle distribution in nugget zone(NZ)through quantitative approach and its consequences on the mechanical property of friction stir welded joints of AA6092/17.5 SiCp-T6 composite.6 mm thick plates are welded at a constant tool tilt angle of 2°and tool traverse speed of 1 mm/s by varying the TRS at 1000 rpm,1500 rpm and 2000 rpm with a taper pin profiled tool.Microstructure analysis shows large quantity of uniformly shaped smaller size SiC particle with lower average particle area which are homogeneously distributed in the NZ.The fragmentation of bigger size particles has been observed because of abrading action of the hard tool and resulting shearing effect and severe stress generation due to the rotation of tool.The particles occupy maximum area in the matrix compared to that of the base material(BM)due to the redistribution of broken particles as an effect of TRS.The migration of particles towards the TMAZ-NZ transition zone has been also encountered at higher TRS(2000 rpm).The microhardness analysis depicts variation in average hardness from top to bottom of the NZ,minimum for 1500 rpm and maximum for 2000 rpm.The impact strength at 1000 rpm and 1500 rpm remains close to that of BM(21.6 J)while 2000 rpm shows the accountable reduction.The maximum joint efficiency has been achieved at 1500 rpm(84%)and minimum at 1000 rpm(68%)under tensile loading.Fractographic analysis shows mixed mode of failure for BM,1000 rpm and 1500 rpm,whereas 2000 rpm shows the brittle mode of failure.
基金Item Sponsored by National Natural Science Foundation of China(60872147)
文摘For the bell-less top blast furnace, when particles move along the chute, the particlesr motion direction and the frictional force acting on them will change due to the chute rotation, which consequently influences the velocity at the tip of chute, changes the burden flow width and impact point, and finally affects the stock profile and gas f[ow distribution. So the influence of chute rotation needs to be considered when calculating the burden trajectory with a mathematical model. The mathematical model was established to analyze the influence of Coriolis force on particle velocity at chute tip as well as height and width of burden flow in chute, and to summarize the effect of Coriolis force on burden distribution, thereby making the calculation result more accurate.
基金Project(51775479)supported by the National Natural Science Foundation of ChinaProject(E2017203046)supported by the Natural Science Foundation of Hebei Province,China
文摘A two-pass annealing/quenching internal spinning process with small-end rotations is proposed to form a curved generatrix conical thin-walled shell.That is,annealing at 360°C for 2 h followed by the 1st pass spinning,and finally quenching in ice water after holding for 1 h at 498°C followed by the 2nd pass spinning.ABAQUS finite element software is used to simulate the internal spinning process of the products formed under different forming parameters.The distribution laws of spinning force,the stress and strain under different forming processes were compared and analyzed.The mechanical properties and microstructure of the products are subsequently analyzed.The results show that the strain and the residual stress in the skin area of the formed products under two-pass spinning process more uniform,and the hardness and the mechanical performance are improved.The microstructure of the products formed with the 0.15 mm thickness reduction at the 2nd pass is excellent.And the second phase grain size distributed uniformly in the range of 36μm.Whereas,the second phase particles are broken seriously and the size distribution inhomogeneity is increased when the thickness reduction in the skin area is greater than 0.20 mm at the 2nd pass spinning process.
