The efficient utilization of propeller slipstream energy is important for improving the ultra-short takeoff and landing capability of Distributed Electric Propulsion(DEP)aircraft.This paper presents a quasi-three-dime...The efficient utilization of propeller slipstream energy is important for improving the ultra-short takeoff and landing capability of Distributed Electric Propulsion(DEP)aircraft.This paper presents a quasi-three-dimensional(2.5D)high-lift wing design approach considering the three-dimensional(3D)effects of slipstream for DEP aircraft,aiming at maximizing the comprehensive lift enhancement benefit of the airframe-propulsion coupling unit.A high-precision and efficient momentum source method is adopted to simulate the slipstream effects,and the distributed propellers are replaced by a rectangular actuator disk to reduce the difficulty of grid generation and improve the grid quality.A detailed comparison of the 2.5D and 3D configurations based on the X-57 ModⅣis performed in terms of flow characteristics and computational cost to demonstrate the rationality of the above design approach.The optimization results of the high-lift wing of the X-57 ModⅣshow that the aerodynamic performance of the landing configuration is significantly improved,for instance,the lift coefficient increases by 0.094 at the angle of attack of 7°,and 0.097 at the angle of attack of 14°.This novel approach achieves efficient and effective design of high-lift wings under the influence of distributed slipstream,which has the potential to improve the design level of DEP aircraft.展开更多
BACKGROUND Esophageal cancer is one of the most common malignant tumors.The three-dimensional quality structure model is a quality assessment theory that includes three dimensions:Structure,process,and results.AIM To ...BACKGROUND Esophageal cancer is one of the most common malignant tumors.The three-dimensional quality structure model is a quality assessment theory that includes three dimensions:Structure,process,and results.AIM To investigate the effects of nursing interventions with three-dimensional quality assessment on the efficacy and disease management ability of patients undergoing esophageal cancer surgery.METHODS In this prospective study,the control group received routine nursing,and the intervention group additionally received a three-dimensional quality assessment intervention based on the above routine care.Self-efficacy and patient disease management abilities were evaluated using the General Self-Efficacy Scale(GSES)and Exercise of Self-Care Agency scale,respectively.IBM SPSS Statistics for Windows,version 17.0,was used for the data processing.RESULTS This study recruited 112 patients who were assigned to the control and experi-mental groups(n=56 per group).Before the intervention,there was no significant difference in GSES scores between the two groups(P>0.05).After the inter-vention,the GSES scores of both groups increased,with the experimental group showing higher values(P<0.05).At the time of discharge and three months after discharge,the scores for positive attitudes,self-stress reduction,and total score of health promotion in the experimental group were higher than those in the control group(P<0.05).CONCLUSION The implementation of a three-dimensional quality structure model for postoperative patients with esophageal cancer can effectively improve their self-management ability and self-efficacy of postoperative patients.展开更多
Excellent progress has been made in the last few decades in the cure rates of pediatric malignancies,with more than 80%of children with cancer who have access to contemporary treatment being cured.However,the therapie...Excellent progress has been made in the last few decades in the cure rates of pediatric malignancies,with more than 80%of children with cancer who have access to contemporary treatment being cured.However,the therapies responsible for this survival can also produce adverse physical and psychological long-term outcomes,referred to as late effects,which appear months to years after the completion of cancer treatment.Research has shown that 60%to 90%of childhood cancer survivors(CCSs)develop one or more chronic health conditions,and 20%to 80%of survivors experience severe or life-threatening complications during adulthood.Therefore,understanding the late side effects of such treatments is important to improve the health and quality of life of the growing population of CCSs.展开更多
A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-indu...A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-induced volume loss effects.The numerical model was verified based on the results of a centrifuge test and a set of parametric studies was implemented based on this model.There is good agreement between the trend of the results of the centrifuge test and the present model.The results of parametric studies show that the tunnelling-induced pile internal force and deformation depend mainly on the pile?tunnel distance,the pile length to tunnel depth ratio and the volume loss.Two different zones are separated by a 45° line projected from the tunnel springline.Within the zone of influence,the pile is subjected to tensile force and large settlement;whereas outside the zone of influence,dragload and small settlement are induced.It is also established that the impact of tunnelling on a pile group is substantially smaller as compared with a single pile in the same location with the rear pile in a group,demonstrating a positive pile group effect.展开更多
A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED, which has been developed through introducing wave-enhanced bottom shear stress, wave dependent surface...A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED, which has been developed through introducing wave-enhanced bottom shear stress, wave dependent surface drag coefficient, wave-induced surface mixing, SWAN, damping function of sediment on turbulence, sediment model and depth-dependent wave radiation stress to COHERENS. The COHERENS-SED is adopted to study the effects induced by wave-induced three-dimensional longshore current on suspended sediment spreading of the Huanghe River (Yellow River) mouth. Several different cases divided by setting different wave parameters of inputting boundary waves are carried out. The modeling results agree with measurement data. In terms of simulation results, it is easy to know that three-dimensional wave radiation stress plays an obvious role when inputting boundary wave height is stronger than 3 m. Moreover, wave direction also affects the sediment spreading rules of the mouth strongly too.展开更多
The fabrication process dependent effects on single event effects (SEEs) are investigated in a commercial silicon- germanium heterojunction bipolar transistor (SiGe HBT) using three-dimensional (3D) TCAD simulat...The fabrication process dependent effects on single event effects (SEEs) are investigated in a commercial silicon- germanium heterojunction bipolar transistor (SiGe HBT) using three-dimensional (3D) TCAD simulations. The influences of device structure and doping concentration on SEEs are discussed via analysis of current transient and charge collection induced by ions strike. The results show that the SEEs representation of current transient is different from representation of the charge collection for the same process parameters. To be specific, the area of C/S junction is the key parameter that affects charge collection of SEE. Both current transient and charge collection are dependent on the doping of collector and substrate. The base doping slightly influences transient currents of base, emitter, and collector terminals. However, the SEEs of SiGe HBT are hardly affected by the doping of epitaxial base and the content of Ge.展开更多
Due to seasonal climate alterations,the microstructure and permeability of granite residual soil are easily affected by multiple dry-wet cycles.The X-ray micro computed tomography(micro-CT)acted as a nondestructive to...Due to seasonal climate alterations,the microstructure and permeability of granite residual soil are easily affected by multiple dry-wet cycles.The X-ray micro computed tomography(micro-CT)acted as a nondestructive tool for characterizing the microstructure of soil samples exposed to a range of damage levels induced by dry-wet cycles.Subsequently,the variations of pore distribution and permeability due to drywet cycling effects were revealed based on three-dimensional(3D)pore distribution analysis and seepage simulations.According to the results,granite residual soils could be separated into four different components,namely,pores,clay,quartz,and hematite,from micro-CT images.The reconstructed 3D pore models dynamically demonstrated the expanding and connecting patterns of pore structures during drywet cycles.The values of porosity and connectivity are positively correlated with the number of dry-wet cycles,which were expressed by exponential and linear functions,respectively.The pore volume probability distribution curves of granite residual soil coincide with the χ^(2)distribution curve,which verifies the effectiveness of the assumption of χ^(2)distribution probability.The pore volume distribution curves suggest that the pores in soils were divided into four types based on their volumes,i.e.micropores,mesopores,macropores,and cracks.From a quantitative and visual perspective,considerable small pores are gradually transformed into cracks with a large volume and a high connectivity.Under the action of dry-wet cycles,the number of seepage flow streamlines which contribute to water permeation in seepage simulation increases distinctly,as well as the permeability and hydraulic conductivity.The calculated hydraulic conductivity is comparable with measured ones with an acceptable error margin in general,verifying the accuracy of seepage simulations based on micro-CT results.展开更多
The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) has been used to investigate the extra-area effects of silver iodide (AgI) seeding on stratiform clouds performed at the supercooled layer.A bulk two-moment m...The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) has been used to investigate the extra-area effects of silver iodide (AgI) seeding on stratiform clouds performed at the supercooled layer.A bulk two-moment microphysical scheme and the new software package for silver iodide are incorporated in MM5.Extra conservation equations are applied to trace the seeding agent,which is transported along the flow field and interacts with the supercooled cloud fields.In this study,the model was run using three nested grids,with 3.3 km × 3.3 km horizontal resolution in the finest grid.The model results showed that seeding with AgI at the 5 to 15℃ levels had microphysical effects on the simulated clouds and that the simulation produced a longer-lasting seeding effect because of the transport of the seeding agent by upper-level winds.Most of the AgI particles acted as deposition nuclei,and the deposition nucleation process contributed mostly to additional cloud ice formation in this study.The results showed that more precipitation results from seeded than unseeded case,and the precipitation was redistributed downwind of the target.Augmented precipitation (varying from 5% to 25% downwind) was confined in space to within 250 km of the seeding target and in time to the 3-h period after initial seeding.展开更多
Heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface were addressed.Analysis was performed in the presence of internal heat generation/absorption. Concentration and therm...Heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface were addressed.Analysis was performed in the presence of internal heat generation/absorption. Concentration and thermal buoyancy effects were accounted. Convective boundary conditions for heat and mass transfer analysis were explored. Series solutions of the resulting problem were developed. Effects of mixed convection, internal heat generation/absorption parameter and Biot numbers on the dimensionless velocity, temperature and concentration distributions were illustrated graphically. Numerical values of local Nusselt and Sherwood numbers were obtained and analyzed for all the physical parameters. It is found that both thermal and concentration boundary layer thicknesses are decreasing functions of stretching ratio. Variations of mixed convection parameter and concentration buoyancy parameter on the velocity profiles and associated boundary layer thicknesses are enhanced. Velocity profiles and temperature increase in the case of internal heat generation while they reduce for heat absorption. Heat transfer Biot number increases the thermal boundary layer thickness and temperature. Also concentration and its associated boundary layer are enhanced with an increase in mass transfer Biot number. The local Nusselt and Sherwood numbers have quite similar behaviors for increasing values of mixed convection parameter, concentration buoyancy parameter and Deborah number.展开更多
Long-term settlements for underground structures, such as tunnels and pipelines, are generally observed after the completion of construction in soft clay. The soil consolidation characteristic has great influences on ...Long-term settlements for underground structures, such as tunnels and pipelines, are generally observed after the completion of construction in soft clay. The soil consolidation characteristic has great influences on the long-term deformation for underground structures. A three-dimensional consolidation analysis method under the asymmetric loads is developed for porous layered soil based on Biot's classical theory. Time-displacement effects can be fully considered in this work and the analytical solutions are obtained by the state space approach in the Cartesian coordinate. The Laplace and double Fourier integral transform are applied to the state variables in order to reduce the partial differential equations into algebraic differential equations and easily obtain the state space solution. Starting from the governing equations of saturated porous soil, the basic relationship of state space variables is established between the ground surface and the arbitrary depth in the integral transform domain. Based on the continuity conditions and boundary conditions of the multi-layered pore soil model, the multi-layered pore half-space solutions are obtained by means of the transfer matrix method and the inverse integral transforms. The accuracy of proposed method is demonstrated with existing classical solutions. The results indicate that the porous homogenous soils as well as the porous non-homogenous layered soils can be considered in this proposed method. When the consolidation time factor is 0.01, the value of immediate consolidation settlement coefficient calculated by the weighted homogenous solution is 27.4% bigger than the one calculated by the non-homogeneity solution. When the consolidation time factor is 0.05, the value of excess pore water pressure for the weighted homogenous solution is 27.2% bigger than the one for the non-homogeneity solution. It is shown that the material non-homogeneity has a great influence on the long-term settlements and the dissipation process of excess pore water pressure.展开更多
Objective: To observe the recently therapeutic effects and toxicity of three-dimensional conformal radiotherapy combined with whole brain irradiation for patients with brain metastasis. Methods: 33 cases were treate...Objective: To observe the recently therapeutic effects and toxicity of three-dimensional conformal radiotherapy combined with whole brain irradiation for patients with brain metastasis. Methods: 33 cases were treated by whole brain irradiation at first, the dose of which was 36-40 Gy (18-20 f). Then three-dimensional conformal radiotherapy was added to the focus with a total dose of 20-25 Gy, whose fractionated dose was 2-5 Gy/time, 5 times/week or 3 times/week. Results: Within 1 month after radiotherapy, according to imaging of the brain, the CR of all patients was 45.5%, PR 36.4%, NC 15.1%, and PD 3%. For the 32 cases with neural symptoms before radiation, the CR of the symptoms was 40.6% and PR 59.4%. All patients gained different increases in KPS grade. By the end of the follow-up period, there were 22 deaths with the mean survival time up to 9.3 months. Conclusion: Three-dimensional conformal radiotherapy combined with whole brain irradiation can not only effectively control brain metastases and improve life quality, but also tends to prolong survival time.展开更多
The effects of fiber volume fraction on damping properties of carbon fiber three-dimensional and five-directional( 3D-5Dir)braided carbon fiber / epoxyres in composite cantilever beams were studied by experimental mod...The effects of fiber volume fraction on damping properties of carbon fiber three-dimensional and five-directional( 3D-5Dir)braided carbon fiber / epoxyres in composite cantilever beams were studied by experimental modal analysis method. Meanwhile,carbon fiber plain woven laminated / epoxy resin composites with different fiber volume fraction were concerned for comparison. The experimental result of braided specimens shows that the first three orders of natural frequency increase and the first three orders of the damping ratios of specimens decrease, when the fiber volume fraction increases. Furthermore,larger fiber volume fraction will be valuable for the better anti-exiting property of braided composites,and get an opposite effect on dissipation of vibration energy. The fiber volume fraction is an important factor for vibration performance design of braided composites. The comparison between the braided specimens and laminated specimens reveals that 3D braided composites have a wider range of damping properties than laminated composites with the same fiber volume fractions.展开更多
In this paper,we introduce a method of quantitatively evaluating and controlling the space charge effect of a lasercooled three-dimensional(3 D) ion system in a linear Paul trap.The relationship among cooling effici...In this paper,we introduce a method of quantitatively evaluating and controlling the space charge effect of a lasercooled three-dimensional(3 D) ion system in a linear Paul trap.The relationship among cooling efficiency,ion quantity,and trapping strength is analyzed quantitatively,and the dynamic space distribution and temporal evolution of the 3 D ion system on a secular motion period time scale in the cooling process are obtained.The ion number influences the eigen-micromotion feature of the ion system.When trapping parameter q is ~ 0.3,relatively ideal cooling efficiency and equilibrium temperature can be obtained.The decrease of axial electrostatic potential is helpful in reducing the micromotion heating effect and the degradation in the total energy.Within a single secular motion period under different cooling conditions,ions transform from the cloud state(each ion disperses throughout the envelope of the ion system) to the liquid state(each ion is concentrated at a specific location in the ion system) and then to the crystal state(each ion is subjected to a fixed motion track).These results are conducive to long-term storage and precise control,motion effect suppression,high-efficiency cooling,and increasing the precision of spectroscopy for a 3 D ion system.展开更多
A mathematical model is constructed to investigate the three-dimensional flow of a non-Newtonian fluid. An in-compressible viscoelastic fluid is used in mathematical formulation. The conjugate convective process (in ...A mathematical model is constructed to investigate the three-dimensional flow of a non-Newtonian fluid. An in-compressible viscoelastic fluid is used in mathematical formulation. The conjugate convective process (in which heat the transfer rate from the bounding surface with a finite capacity is proportional to the local surface temperature) in three-dimensional flow of a differential type of non-Newtonian fluid is analyzed for the first time. Series solutions for the nonlinear differential system are computed. Plots are presented for the description of emerging parameters entering into the problem. It is observed that the conjugate heating phenomenon causes an appreciable increase in the temperature at the stretching wall.展开更多
Porous three-dimensional (3D) structures generally improve the performance of electrodes by increasing their active surface area and the diffusion speed of electrolyte ions during charging/discharging.Threedimensional...Porous three-dimensional (3D) structures generally improve the performance of electrodes by increasing their active surface area and the diffusion speed of electrolyte ions during charging/discharging.Threedimensional polypyrrole (PPy) based films were created by electrodepositing PPy in the presence of varying amounts of chloride anions (Cl^(-)) and polyanionic ribbonlike nanoparticles (carboxylated cellulose nanocrystals (CNC-COO-)) as scaffold material.The assembly mechanism of the 3D PPy electrodes combines the effect of different nucleation and growth mechanisms during electropolymerization and deposition of the formed PPy with CNC-COO-and with Cl^(-).The highest area capacitance of these electrode materials was 1.39 F cm^(-2)(150.2 F g^(-1)) at a current density of 1 m A cm^(-2)(0.1 A g^(-1)).More importantly,at a high current density of 20 m A cm^(-2)(2.2 A g^(-1)),the thick (ca.130μm),3D,and high mass loading(9.2 mg cm^(-2)) Cl^(-):CNC-COO-/PPy films exhibited an excellent areal capacitance of 0.85 F cm^(-2)(70.8 F g^(-1)),increasing about 16%over CNC-COO-/PPy films prepared without Cl^(-)present during electrodeposition.In addition,an aqueous Cl^(-):CNC-COO-/PPy (with Cl^(-):CNC-COO-=2.0) symmetric supercapacitor had an outstanding energy density of 41.15μWh cm^(-2)(4.46 Wh kg^(-1)) and excellent cycling stability,while even improving on its original areal capacitance (to 111.2%of its original capacitance) after cycling3000 cycles at 8 m A cm^(-2),indicating their potential in energy storage devices.展开更多
To shorten the preparation process of semi-solid billets,semi-solid billets of 2A14 aluminum alloy were prepared by wrought aluminum directly semi-solid isothermal treatment(WADSSIT)process.Three-dimension(3D)combined...To shorten the preparation process of semi-solid billets,semi-solid billets of 2A14 aluminum alloy were prepared by wrought aluminum directly semi-solid isothermal treatment(WADSSIT)process.Three-dimension(3D)combined microstructure evolution,namely transverse direction(TD)surface,rolling direction(RD)surface,and normal direction(ND)surface,was studied.Effects of temperature and holding time on average grain size and average shape factor were investigated.The results showed that the optimum conditions for preparation of 2A14 semi-solid billets by this process were 615℃ and 20 min(average grain size of 124μm and shape factor of 0.81).Electron backscatter diffraction(EBSD)observations indicated that the microstructure was completely recrystallized when it was heated to 600℃.Grain size was increased with the increase of temperature and grew up slowly with the holding time prolonging.Roundness was increased with increase of holding time but was not sensitive to temperature.展开更多
Objective: Radiation therapy is an important component of the multidisciplinary management of esophageal carcinoma. Three-dimensional conformal radiation therapy requires the precise definition of the target volume. ...Objective: Radiation therapy is an important component of the multidisciplinary management of esophageal carcinoma. Three-dimensional conformal radiation therapy requires the precise definition of the target volume. We aimed to compare the treatment results and radiation toxicities between three-dimensional conformal radiotherapy (3D-CRT) and conventional radiotherapy (CR) for patients with cervical and thoracic esophageal carcinoma. Methods: From June 2004 to December 2006, a random study was performed on 106 patients treated with 3D-CRT or CR, 53 patients in each group. The patients in CR group received conventional radiotherapy in 2.0 Gy/f, 5 f/week and total dose was 66-70 Gy in 6.5 or 7 weeks. The patients in 3D-CRT group were treated by 3D-CRT in 2.0 Gy/f, 5 f/week and total dose was 64-70 Gy in 6 weeks. The local control rates, survival rates and radiation toxicities for the two groups were investigated. Results: The 1-year and 3-year local control rates were 83.0% and 60.4% in 3D-CRT group and 64.2% (x^2 = 4.853, P = 0.028) and 32.1% (x^2 = 9.812, P = 0.002) in CR group. The 1-year and 3-year survival rates were 73.6% and 50.9% in 3D-CRT group and 54.7% (x^2 = 4.102, P = 0.043) and 32.1% (x^2 = 3.886, P = 0.049) in CR group. Between the two groups, there was no significant difference in radiation toxicities. Conclusien: The 1-year and 3-year local control rates and survival rates of patients with esophageal carcinoma treated by 3D-CRT is superior to CR. However, longer-term results and radiation toxicity need further study which involves more patients and prolonged follow-up.展开更多
This work systematically investigates the microstructure-property relationship in Mg alloys. Emphasis is placed on understanding, through high resolution crystal plasticity modeling, how grain size and texture collect...This work systematically investigates the microstructure-property relationship in Mg alloys. Emphasis is placed on understanding, through high resolution crystal plasticity modeling, how grain size and texture collectively impact material strengthening and hardening, net plastic anisotropy, and tension-compression asymmetry. To achieve this, 528 fully three-dimensional finite element calculations are performed, which comprise eleven textures, four grain sizes, six loading orientations, and two uniaxial loading states(tension and compression). The grain size effect follows Hall-Petch relation that depends on both, loading orientation and initial texture. The reduction in extension twinning with grain size refinement is influenced by texture as well. Below a threshold textural strength, grain size refinement leads to an appreciable reduction in the net plastic anisotropy at yield, quantified using Hill anisotropy, and reduced tension-compression asymmetry. Using a micromechanical basis, the effect of grain size and texture on material ductility is predicted to be non-monotonic. The computational predictions serve as synthetic data sets for experimental validation and reduced-order modeling.展开更多
Three-dimensional direct numerical simulations of the wake flow downstream of a near-wall circular cylinder at different gap ratios and boundary layer thicknesses are carried out by using the iterative immersed bounda...Three-dimensional direct numerical simulations of the wake flow downstream of a near-wall circular cylinder at different gap ratios and boundary layer thicknesses are carried out by using the iterative immersed boundary method.The non-dimensional gap between the cylinder and the wall,G/D=0.2,0.6 and 1.0,the non-dimensional boundary layer thickness,δ/D=0.0,0.7 and 1.6,the Reynolds number,Re=350,and the aspect ratio of the cylinder,L/D=25are adopted.High-resolution visualizations of the complex vortex structures at differentδ/D and G/D are presented.The transition of the streamwise vortex mode,the combined effects ofδ/D and G/D on the flow statistics,the pressure and shear stress distribution and the hydrodynamic forces are analyzed.Results show that with decreasing G/D and increasingδ/D,the gap flow and its vortex-shedding are significantly weakened,together with an elongated wake and an enlarged low-velocity area near the wall,leading to the wake mode transition from the two-sided to one-sided vortex-shedding.Different relative positions of the cylinder regarding the boundary layer alter the flow features of the shear layers.With an increase inδ/D,the front stagnation point shifts to the upper surface,and the distance between the flow divergence point and the maximum pressure position increases.The mean drag coefficient and r.m.s.values of drag and lift coefficients decrease with a decrease in G/D and an increase inδ/D,while the mean lift coefficient increases with decreasing G/D but decreases with increasingδ/D.展开更多
Formulation/pharmaceutical excipients play a major role in formulating drug candidates,with the objectives of ease of administration,targeted delivery and complete availability.Many excipients used in pharmaceutical f...Formulation/pharmaceutical excipients play a major role in formulating drug candidates,with the objectives of ease of administration,targeted delivery and complete availability.Many excipients used in pharmaceutical formulations are orphanized in preclinical drug discovery.These orphan excipients could enhance formulatability of highly lipophilic compounds.Additionally,they are safe in preclinical species when used below the LD50 values.However,when the excipients are used in formulating compounds with diverse physico-chemical properties,they pose challenges by modulating study results through their bioanalytical matrix effects.Excipients invariably present in study samples and not in the calibration curve standards cause over-/under-estimation of exposures.Thus,the mechanism by which excipients cause matrix effects and strategies to nullify these effects needs to be revisited.Furthermore,formulation excipients cause drug interactions by moderating the pathways of drug metabolizing enzymes and drug transport proteins.Although it is not possible to get rid of excipient driven interactions,it is always advised to be aware of these interactions and apply the knowledge to draw meaningful conclusions from study results.In this review,we will comprehensively discuss a)orphan excipients that have wider applications in preclinical formulations,b)bioanalytical matrix effects and possible approaches to mitigating these effects,and c)excipient driven drug interactions and strategies to alleviate the impacts of drug interactions.展开更多
文摘The efficient utilization of propeller slipstream energy is important for improving the ultra-short takeoff and landing capability of Distributed Electric Propulsion(DEP)aircraft.This paper presents a quasi-three-dimensional(2.5D)high-lift wing design approach considering the three-dimensional(3D)effects of slipstream for DEP aircraft,aiming at maximizing the comprehensive lift enhancement benefit of the airframe-propulsion coupling unit.A high-precision and efficient momentum source method is adopted to simulate the slipstream effects,and the distributed propellers are replaced by a rectangular actuator disk to reduce the difficulty of grid generation and improve the grid quality.A detailed comparison of the 2.5D and 3D configurations based on the X-57 ModⅣis performed in terms of flow characteristics and computational cost to demonstrate the rationality of the above design approach.The optimization results of the high-lift wing of the X-57 ModⅣshow that the aerodynamic performance of the landing configuration is significantly improved,for instance,the lift coefficient increases by 0.094 at the angle of attack of 7°,and 0.097 at the angle of attack of 14°.This novel approach achieves efficient and effective design of high-lift wings under the influence of distributed slipstream,which has the potential to improve the design level of DEP aircraft.
文摘BACKGROUND Esophageal cancer is one of the most common malignant tumors.The three-dimensional quality structure model is a quality assessment theory that includes three dimensions:Structure,process,and results.AIM To investigate the effects of nursing interventions with three-dimensional quality assessment on the efficacy and disease management ability of patients undergoing esophageal cancer surgery.METHODS In this prospective study,the control group received routine nursing,and the intervention group additionally received a three-dimensional quality assessment intervention based on the above routine care.Self-efficacy and patient disease management abilities were evaluated using the General Self-Efficacy Scale(GSES)and Exercise of Self-Care Agency scale,respectively.IBM SPSS Statistics for Windows,version 17.0,was used for the data processing.RESULTS This study recruited 112 patients who were assigned to the control and experi-mental groups(n=56 per group).Before the intervention,there was no significant difference in GSES scores between the two groups(P>0.05).After the inter-vention,the GSES scores of both groups increased,with the experimental group showing higher values(P<0.05).At the time of discharge and three months after discharge,the scores for positive attitudes,self-stress reduction,and total score of health promotion in the experimental group were higher than those in the control group(P<0.05).CONCLUSION The implementation of a three-dimensional quality structure model for postoperative patients with esophageal cancer can effectively improve their self-management ability and self-efficacy of postoperative patients.
文摘Excellent progress has been made in the last few decades in the cure rates of pediatric malignancies,with more than 80%of children with cancer who have access to contemporary treatment being cured.However,the therapies responsible for this survival can also produce adverse physical and psychological long-term outcomes,referred to as late effects,which appear months to years after the completion of cancer treatment.Research has shown that 60%to 90%of childhood cancer survivors(CCSs)develop one or more chronic health conditions,and 20%to 80%of survivors experience severe or life-threatening complications during adulthood.Therefore,understanding the late side effects of such treatments is important to improve the health and quality of life of the growing population of CCSs.
文摘A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-induced volume loss effects.The numerical model was verified based on the results of a centrifuge test and a set of parametric studies was implemented based on this model.There is good agreement between the trend of the results of the centrifuge test and the present model.The results of parametric studies show that the tunnelling-induced pile internal force and deformation depend mainly on the pile?tunnel distance,the pile length to tunnel depth ratio and the volume loss.Two different zones are separated by a 45° line projected from the tunnel springline.Within the zone of influence,the pile is subjected to tensile force and large settlement;whereas outside the zone of influence,dragload and small settlement are induced.It is also established that the impact of tunnelling on a pile group is substantially smaller as compared with a single pile in the same location with the rear pile in a group,demonstrating a positive pile group effect.
基金The Natural Science Foundation Study on Mechanics of Non-breaking wave-induced vertical mixing on Pollutant Dispersion of Huanghe River Estuary under contract No.51179178Project from Establishment of Fine Sediment Transport Modeling System for the Yellow Sea+1 种基金which is a sub-project of Development of Operational Oceanographic systemScience & Technology Development Project of Qingdao under contract No.09-1-3-18-jch
文摘A three-dimensional wave radiation stress is introduced into the hydrodynamic sediment coupled model COHERENS-SED, which has been developed through introducing wave-enhanced bottom shear stress, wave dependent surface drag coefficient, wave-induced surface mixing, SWAN, damping function of sediment on turbulence, sediment model and depth-dependent wave radiation stress to COHERENS. The COHERENS-SED is adopted to study the effects induced by wave-induced three-dimensional longshore current on suspended sediment spreading of the Huanghe River (Yellow River) mouth. Several different cases divided by setting different wave parameters of inputting boundary waves are carried out. The modeling results agree with measurement data. In terms of simulation results, it is easy to know that three-dimensional wave radiation stress plays an obvious role when inputting boundary wave height is stronger than 3 m. Moreover, wave direction also affects the sediment spreading rules of the mouth strongly too.
基金supported by the National Natural Science Foundation of China(Grant Nos.61274106,11175138,and 61601352)
文摘The fabrication process dependent effects on single event effects (SEEs) are investigated in a commercial silicon- germanium heterojunction bipolar transistor (SiGe HBT) using three-dimensional (3D) TCAD simulations. The influences of device structure and doping concentration on SEEs are discussed via analysis of current transient and charge collection induced by ions strike. The results show that the SEEs representation of current transient is different from representation of the charge collection for the same process parameters. To be specific, the area of C/S junction is the key parameter that affects charge collection of SEE. Both current transient and charge collection are dependent on the doping of collector and substrate. The base doping slightly influences transient currents of base, emitter, and collector terminals. However, the SEEs of SiGe HBT are hardly affected by the doping of epitaxial base and the content of Ge.
基金supported by the National Natural Science Foundation of China (Grant Nos. 12102312 and 41372314)State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Open Foundation, Chengdu University of Technology, China (Grant No. SKLGP2021K011)
文摘Due to seasonal climate alterations,the microstructure and permeability of granite residual soil are easily affected by multiple dry-wet cycles.The X-ray micro computed tomography(micro-CT)acted as a nondestructive tool for characterizing the microstructure of soil samples exposed to a range of damage levels induced by dry-wet cycles.Subsequently,the variations of pore distribution and permeability due to drywet cycling effects were revealed based on three-dimensional(3D)pore distribution analysis and seepage simulations.According to the results,granite residual soils could be separated into four different components,namely,pores,clay,quartz,and hematite,from micro-CT images.The reconstructed 3D pore models dynamically demonstrated the expanding and connecting patterns of pore structures during drywet cycles.The values of porosity and connectivity are positively correlated with the number of dry-wet cycles,which were expressed by exponential and linear functions,respectively.The pore volume probability distribution curves of granite residual soil coincide with the χ^(2)distribution curve,which verifies the effectiveness of the assumption of χ^(2)distribution probability.The pore volume distribution curves suggest that the pores in soils were divided into four types based on their volumes,i.e.micropores,mesopores,macropores,and cracks.From a quantitative and visual perspective,considerable small pores are gradually transformed into cracks with a large volume and a high connectivity.Under the action of dry-wet cycles,the number of seepage flow streamlines which contribute to water permeation in seepage simulation increases distinctly,as well as the permeability and hydraulic conductivity.The calculated hydraulic conductivity is comparable with measured ones with an acceptable error margin in general,verifying the accuracy of seepage simulations based on micro-CT results.
基金supported by the National Natural Science Foundation of China (Grant No. 40805056)the National Key Technologies R&D Program of China (Grant No. 2006BAC12B00)
文摘The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) has been used to investigate the extra-area effects of silver iodide (AgI) seeding on stratiform clouds performed at the supercooled layer.A bulk two-moment microphysical scheme and the new software package for silver iodide are incorporated in MM5.Extra conservation equations are applied to trace the seeding agent,which is transported along the flow field and interacts with the supercooled cloud fields.In this study,the model was run using three nested grids,with 3.3 km × 3.3 km horizontal resolution in the finest grid.The model results showed that seeding with AgI at the 5 to 15℃ levels had microphysical effects on the simulated clouds and that the simulation produced a longer-lasting seeding effect because of the transport of the seeding agent by upper-level winds.Most of the AgI particles acted as deposition nuclei,and the deposition nucleation process contributed mostly to additional cloud ice formation in this study.The results showed that more precipitation results from seeded than unseeded case,and the precipitation was redistributed downwind of the target.Augmented precipitation (varying from 5% to 25% downwind) was confined in space to within 250 km of the seeding target and in time to the 3-h period after initial seeding.
文摘Heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface were addressed.Analysis was performed in the presence of internal heat generation/absorption. Concentration and thermal buoyancy effects were accounted. Convective boundary conditions for heat and mass transfer analysis were explored. Series solutions of the resulting problem were developed. Effects of mixed convection, internal heat generation/absorption parameter and Biot numbers on the dimensionless velocity, temperature and concentration distributions were illustrated graphically. Numerical values of local Nusselt and Sherwood numbers were obtained and analyzed for all the physical parameters. It is found that both thermal and concentration boundary layer thicknesses are decreasing functions of stretching ratio. Variations of mixed convection parameter and concentration buoyancy parameter on the velocity profiles and associated boundary layer thicknesses are enhanced. Velocity profiles and temperature increase in the case of internal heat generation while they reduce for heat absorption. Heat transfer Biot number increases the thermal boundary layer thickness and temperature. Also concentration and its associated boundary layer are enhanced with an increase in mass transfer Biot number. The local Nusselt and Sherwood numbers have quite similar behaviors for increasing values of mixed convection parameter, concentration buoyancy parameter and Deborah number.
基金Project(51008188)supported by National Natural Science Foundation of ChinaProject(KLE-TJGE-B1302)supported by Key Laboratory Fund of Geotechnical and Underground Engineering of Ministry of Education,ChinaProject(SKLGDUEK1205)supported by Open Program of State Key Laboratory for Geomechanics and Deep Underground Engineering,China
文摘Long-term settlements for underground structures, such as tunnels and pipelines, are generally observed after the completion of construction in soft clay. The soil consolidation characteristic has great influences on the long-term deformation for underground structures. A three-dimensional consolidation analysis method under the asymmetric loads is developed for porous layered soil based on Biot's classical theory. Time-displacement effects can be fully considered in this work and the analytical solutions are obtained by the state space approach in the Cartesian coordinate. The Laplace and double Fourier integral transform are applied to the state variables in order to reduce the partial differential equations into algebraic differential equations and easily obtain the state space solution. Starting from the governing equations of saturated porous soil, the basic relationship of state space variables is established between the ground surface and the arbitrary depth in the integral transform domain. Based on the continuity conditions and boundary conditions of the multi-layered pore soil model, the multi-layered pore half-space solutions are obtained by means of the transfer matrix method and the inverse integral transforms. The accuracy of proposed method is demonstrated with existing classical solutions. The results indicate that the porous homogenous soils as well as the porous non-homogenous layered soils can be considered in this proposed method. When the consolidation time factor is 0.01, the value of immediate consolidation settlement coefficient calculated by the weighted homogenous solution is 27.4% bigger than the one calculated by the non-homogeneity solution. When the consolidation time factor is 0.05, the value of excess pore water pressure for the weighted homogenous solution is 27.2% bigger than the one for the non-homogeneity solution. It is shown that the material non-homogeneity has a great influence on the long-term settlements and the dissipation process of excess pore water pressure.
文摘Objective: To observe the recently therapeutic effects and toxicity of three-dimensional conformal radiotherapy combined with whole brain irradiation for patients with brain metastasis. Methods: 33 cases were treated by whole brain irradiation at first, the dose of which was 36-40 Gy (18-20 f). Then three-dimensional conformal radiotherapy was added to the focus with a total dose of 20-25 Gy, whose fractionated dose was 2-5 Gy/time, 5 times/week or 3 times/week. Results: Within 1 month after radiotherapy, according to imaging of the brain, the CR of all patients was 45.5%, PR 36.4%, NC 15.1%, and PD 3%. For the 32 cases with neural symptoms before radiation, the CR of the symptoms was 40.6% and PR 59.4%. All patients gained different increases in KPS grade. By the end of the follow-up period, there were 22 deaths with the mean survival time up to 9.3 months. Conclusion: Three-dimensional conformal radiotherapy combined with whole brain irradiation can not only effectively control brain metastases and improve life quality, but also tends to prolong survival time.
基金Tianjin Municipal Science and Technologies Commission,China(Nos.10SYSYJC27800,1ZCKFSF00500)
文摘The effects of fiber volume fraction on damping properties of carbon fiber three-dimensional and five-directional( 3D-5Dir)braided carbon fiber / epoxyres in composite cantilever beams were studied by experimental modal analysis method. Meanwhile,carbon fiber plain woven laminated / epoxy resin composites with different fiber volume fraction were concerned for comparison. The experimental result of braided specimens shows that the first three orders of natural frequency increase and the first three orders of the damping ratios of specimens decrease, when the fiber volume fraction increases. Furthermore,larger fiber volume fraction will be valuable for the better anti-exiting property of braided composites,and get an opposite effect on dissipation of vibration energy. The fiber volume fraction is an important factor for vibration performance design of braided composites. The comparison between the braided specimens and laminated specimens reveals that 3D braided composites have a wider range of damping properties than laminated composites with the same fiber volume fractions.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0304401)the National Natural Science Foundation of China(Grant Nos.11622434,11474318,91336211,and 11634013)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB21030100)Hubei Province Science Fund for Distinguished Young Scholars(Grant No.2017CFA040)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2015274)
文摘In this paper,we introduce a method of quantitatively evaluating and controlling the space charge effect of a lasercooled three-dimensional(3 D) ion system in a linear Paul trap.The relationship among cooling efficiency,ion quantity,and trapping strength is analyzed quantitatively,and the dynamic space distribution and temporal evolution of the 3 D ion system on a secular motion period time scale in the cooling process are obtained.The ion number influences the eigen-micromotion feature of the ion system.When trapping parameter q is ~ 0.3,relatively ideal cooling efficiency and equilibrium temperature can be obtained.The decrease of axial electrostatic potential is helpful in reducing the micromotion heating effect and the degradation in the total energy.Within a single secular motion period under different cooling conditions,ions transform from the cloud state(each ion disperses throughout the envelope of the ion system) to the liquid state(each ion is concentrated at a specific location in the ion system) and then to the crystal state(each ion is subjected to a fixed motion track).These results are conducive to long-term storage and precise control,motion effect suppression,high-efficiency cooling,and increasing the precision of spectroscopy for a 3 D ion system.
基金Project supported by the Deanship of Scientific Research(DSR),King Abdulaziz University,Jeddah(Grant No.10-130/1434HiCi)
文摘A mathematical model is constructed to investigate the three-dimensional flow of a non-Newtonian fluid. An in-compressible viscoelastic fluid is used in mathematical formulation. The conjugate convective process (in which heat the transfer rate from the bounding surface with a finite capacity is proportional to the local surface temperature) in three-dimensional flow of a differential type of non-Newtonian fluid is analyzed for the first time. Series solutions for the nonlinear differential system are computed. Plots are presented for the description of emerging parameters entering into the problem. It is observed that the conjugate heating phenomenon causes an appreciable increase in the temperature at the stretching wall.
基金supported by the Research Foundation Flanders,Belgium(3E181170 and 12Y0319N)supported by the China Scholarship Council,China(CSC,201806220066)。
文摘Porous three-dimensional (3D) structures generally improve the performance of electrodes by increasing their active surface area and the diffusion speed of electrolyte ions during charging/discharging.Threedimensional polypyrrole (PPy) based films were created by electrodepositing PPy in the presence of varying amounts of chloride anions (Cl^(-)) and polyanionic ribbonlike nanoparticles (carboxylated cellulose nanocrystals (CNC-COO-)) as scaffold material.The assembly mechanism of the 3D PPy electrodes combines the effect of different nucleation and growth mechanisms during electropolymerization and deposition of the formed PPy with CNC-COO-and with Cl^(-).The highest area capacitance of these electrode materials was 1.39 F cm^(-2)(150.2 F g^(-1)) at a current density of 1 m A cm^(-2)(0.1 A g^(-1)).More importantly,at a high current density of 20 m A cm^(-2)(2.2 A g^(-1)),the thick (ca.130μm),3D,and high mass loading(9.2 mg cm^(-2)) Cl^(-):CNC-COO-/PPy films exhibited an excellent areal capacitance of 0.85 F cm^(-2)(70.8 F g^(-1)),increasing about 16%over CNC-COO-/PPy films prepared without Cl^(-)present during electrodeposition.In addition,an aqueous Cl^(-):CNC-COO-/PPy (with Cl^(-):CNC-COO-=2.0) symmetric supercapacitor had an outstanding energy density of 41.15μWh cm^(-2)(4.46 Wh kg^(-1)) and excellent cycling stability,while even improving on its original areal capacitance (to 111.2%of its original capacitance) after cycling3000 cycles at 8 m A cm^(-2),indicating their potential in energy storage devices.
基金financially supported by the National Natural Science Foundation of China (No.51875124)the National Key Research and Development Project,China (No.2019YFB2006503)。
文摘To shorten the preparation process of semi-solid billets,semi-solid billets of 2A14 aluminum alloy were prepared by wrought aluminum directly semi-solid isothermal treatment(WADSSIT)process.Three-dimension(3D)combined microstructure evolution,namely transverse direction(TD)surface,rolling direction(RD)surface,and normal direction(ND)surface,was studied.Effects of temperature and holding time on average grain size and average shape factor were investigated.The results showed that the optimum conditions for preparation of 2A14 semi-solid billets by this process were 615℃ and 20 min(average grain size of 124μm and shape factor of 0.81).Electron backscatter diffraction(EBSD)observations indicated that the microstructure was completely recrystallized when it was heated to 600℃.Grain size was increased with the increase of temperature and grew up slowly with the holding time prolonging.Roundness was increased with increase of holding time but was not sensitive to temperature.
文摘Objective: Radiation therapy is an important component of the multidisciplinary management of esophageal carcinoma. Three-dimensional conformal radiation therapy requires the precise definition of the target volume. We aimed to compare the treatment results and radiation toxicities between three-dimensional conformal radiotherapy (3D-CRT) and conventional radiotherapy (CR) for patients with cervical and thoracic esophageal carcinoma. Methods: From June 2004 to December 2006, a random study was performed on 106 patients treated with 3D-CRT or CR, 53 patients in each group. The patients in CR group received conventional radiotherapy in 2.0 Gy/f, 5 f/week and total dose was 66-70 Gy in 6.5 or 7 weeks. The patients in 3D-CRT group were treated by 3D-CRT in 2.0 Gy/f, 5 f/week and total dose was 64-70 Gy in 6 weeks. The local control rates, survival rates and radiation toxicities for the two groups were investigated. Results: The 1-year and 3-year local control rates were 83.0% and 60.4% in 3D-CRT group and 64.2% (x^2 = 4.853, P = 0.028) and 32.1% (x^2 = 9.812, P = 0.002) in CR group. The 1-year and 3-year survival rates were 73.6% and 50.9% in 3D-CRT group and 54.7% (x^2 = 4.102, P = 0.043) and 32.1% (x^2 = 3.886, P = 0.049) in CR group. Between the two groups, there was no significant difference in radiation toxicities. Conclusien: The 1-year and 3-year local control rates and survival rates of patients with esophageal carcinoma treated by 3D-CRT is superior to CR. However, longer-term results and radiation toxicity need further study which involves more patients and prolonged follow-up.
基金support provided by the National Science Foundation under Grant Number CMMI-1932976the U.S.Army Research Laboratory under Cooperative Agreement Number W911NF-12-2-0022。
文摘This work systematically investigates the microstructure-property relationship in Mg alloys. Emphasis is placed on understanding, through high resolution crystal plasticity modeling, how grain size and texture collectively impact material strengthening and hardening, net plastic anisotropy, and tension-compression asymmetry. To achieve this, 528 fully three-dimensional finite element calculations are performed, which comprise eleven textures, four grain sizes, six loading orientations, and two uniaxial loading states(tension and compression). The grain size effect follows Hall-Petch relation that depends on both, loading orientation and initial texture. The reduction in extension twinning with grain size refinement is influenced by texture as well. Below a threshold textural strength, grain size refinement leads to an appreciable reduction in the net plastic anisotropy at yield, quantified using Hill anisotropy, and reduced tension-compression asymmetry. Using a micromechanical basis, the effect of grain size and texture on material ductility is predicted to be non-monotonic. The computational predictions serve as synthetic data sets for experimental validation and reduced-order modeling.
基金financially supported by the National Key R&D Program of China (Grant No.2022YFB2603000)the National Natural Science Foundation of China (Grant Nos.51779172 and 52179076)。
文摘Three-dimensional direct numerical simulations of the wake flow downstream of a near-wall circular cylinder at different gap ratios and boundary layer thicknesses are carried out by using the iterative immersed boundary method.The non-dimensional gap between the cylinder and the wall,G/D=0.2,0.6 and 1.0,the non-dimensional boundary layer thickness,δ/D=0.0,0.7 and 1.6,the Reynolds number,Re=350,and the aspect ratio of the cylinder,L/D=25are adopted.High-resolution visualizations of the complex vortex structures at differentδ/D and G/D are presented.The transition of the streamwise vortex mode,the combined effects ofδ/D and G/D on the flow statistics,the pressure and shear stress distribution and the hydrodynamic forces are analyzed.Results show that with decreasing G/D and increasingδ/D,the gap flow and its vortex-shedding are significantly weakened,together with an elongated wake and an enlarged low-velocity area near the wall,leading to the wake mode transition from the two-sided to one-sided vortex-shedding.Different relative positions of the cylinder regarding the boundary layer alter the flow features of the shear layers.With an increase inδ/D,the front stagnation point shifts to the upper surface,and the distance between the flow divergence point and the maximum pressure position increases.The mean drag coefficient and r.m.s.values of drag and lift coefficients decrease with a decrease in G/D and an increase inδ/D,while the mean lift coefficient increases with decreasing G/D but decreases with increasingδ/D.
文摘Formulation/pharmaceutical excipients play a major role in formulating drug candidates,with the objectives of ease of administration,targeted delivery and complete availability.Many excipients used in pharmaceutical formulations are orphanized in preclinical drug discovery.These orphan excipients could enhance formulatability of highly lipophilic compounds.Additionally,they are safe in preclinical species when used below the LD50 values.However,when the excipients are used in formulating compounds with diverse physico-chemical properties,they pose challenges by modulating study results through their bioanalytical matrix effects.Excipients invariably present in study samples and not in the calibration curve standards cause over-/under-estimation of exposures.Thus,the mechanism by which excipients cause matrix effects and strategies to nullify these effects needs to be revisited.Furthermore,formulation excipients cause drug interactions by moderating the pathways of drug metabolizing enzymes and drug transport proteins.Although it is not possible to get rid of excipient driven interactions,it is always advised to be aware of these interactions and apply the knowledge to draw meaningful conclusions from study results.In this review,we will comprehensively discuss a)orphan excipients that have wider applications in preclinical formulations,b)bioanalytical matrix effects and possible approaches to mitigating these effects,and c)excipient driven drug interactions and strategies to alleviate the impacts of drug interactions.