In recent years,tuned liquid dampers(TLDs)have emerged as a focal point of research due to their remarkable potential for structural vibration mitigation.Yet,progress in this field remains constrained by an incomplete...In recent years,tuned liquid dampers(TLDs)have emerged as a focal point of research due to their remarkable potential for structural vibration mitigation.Yet,progress in this field remains constrained by an incomplete understanding of the fundamental mechanisms governing sloshing-induced loads in liquid-filled containers.Aqueducts present a distinctive case,as the capacity of their contained water to function effectively as a TLD remains uncertain.To address this gap,the present study investigates the generation mechanisms of sloshing loads under non-resonant cases through a two-dimensional(2D)computational fluid dynamics(CFD)model developed in ANSYS Fluent.The incompressible Reynolds-Averaged Navier–Stokes(RANS)equations are solved,while the Volume of Fluid(VOF)method captures the evolution of the air–water interface.Turbulent flow behavior is modeled using the RNG-approach.The ensuing results reveal the dynamic characteristics of the horizontal force(fℎ)and the fluctuating component of the vertical force(Fof).Fh is predominantly governed by the inertia of the deep-water region and its phase varies coherently with the aqueduct’s acceleration.With increasing excitation amplitude(A)and frequency(f),the contribution of deep-water inertia to𝐹ℎintensifies markedly,accounting for 82.6–92.1%of the total horizontal load at an excitation amplitude of 0.15 m and frequencies of 1.0–1.6 Hz.The extreme values of Fof arise primarily from asymmetric static pressures induced by free-surface fluctuations,which are further amplified when wall gaps appear at large amplitudes(A≥10 cm)and high frequencies(f≥1.4 Hz).Unlike resonant cases dominated by free-surface resonance,non-resonant sloshing loads are principally driven by deep-water inertia and motion-induced surface asymmetry.展开更多
As a core power device in strategic industries such as new energy power generation and electric vehicles,the thermal reliability of IGBT modules directly determines the performance and lifetime of the whole system.A s...As a core power device in strategic industries such as new energy power generation and electric vehicles,the thermal reliability of IGBT modules directly determines the performance and lifetime of the whole system.A synergistic optimization structure of“inlet plate-channel spoiler columns”is proposed for the local hot spot problem during the operation of Insulated Gate Bipolar Transistor(IGBT),combined with the inherent defect of uneven flow distribution of the traditional U-type liquid cooling plate in this paper.The influences of the shape,height(H),and spacing from the spoiler column(b)of the plate on the comprehensive heat dissipation performance of the liquid cooling plate are analyzed at different Reynolds numbers,A dual heat source strategy is introduced and the effect of the optimized structure is evaluated by the temperature inhomogeneity coefficient(Φ).The results show that the optimum effect is achieved when the shape of the plate is square,H=4.5 mm,b=2 mm,and u=0.05 m/s,at which the HTPE=1.09 and Φ are reduced by 40%.In contrast,the maximum temperatures of the IGBT and the FWD(Free Wheeling Diode)chips are reduced by 8.7 and 8.4 K,respectively,and ΔP rises by only 1.58 Pa while keeping ΔT not significantly increased.This optimized configuration achieves a significant reduction in the critical chip temperature and optimization of the flow field uniformity with almost no change in the system flow resistance.It breaks through the limitation of single structure optimization of the traditional liquid cooling plate and effectively solves the problem of uneven flow in the U-shaped cooling plate,which provides a new solution with important engineering value for the thermal management of IGBT modules.展开更多
In recent years,tuned liquid dampers(TLDs)have attracted significant research interest;however,overall progress has been limited due to insufficient understanding of the mechanisms governing sloshing-induced loads.In ...In recent years,tuned liquid dampers(TLDs)have attracted significant research interest;however,overall progress has been limited due to insufficient understanding of the mechanisms governing sloshing-induced loads.In particular,it remains unclear whether the water in aqueducts—common water-diversion structures in many countries—can serve as an effective TLD.This study investigates the generation mechanisms of sloshing loads during the first-order transverse resonance of water in a U-shaped aqueduct using a two-dimensional(2D)numerical model.The results reveal that,at the equilibrium position,the free surface difference between the left and right walls,the horizontal force on the aqueduct,and the fluctuating component of the vertical force all reach their maxima,with energy predominantly stored as potential energy.At the maximum displacement position,the surface difference and horizontal force drop to zero,while the fluctuating vertical force attains its minimum and energy shifts primarily to kinetic form.At this stage,static pressure is governed solely by the vertical convective acceleration,whereas at equilibrium it is closely linked to both the free surface difference and vertical local acceleration of the water.This dynamic energy exchange generates vertical force oscillations even when the free surface appears nearly symmetric.展开更多
Diplodia tip blight,caused by Diplodia sapinea,is a global pine necrotic disease causing heavy economic losses to the pine industry.Chemical control,its main current management,easily induces pathogen resistance and e...Diplodia tip blight,caused by Diplodia sapinea,is a global pine necrotic disease causing heavy economic losses to the pine industry.Chemical control,its main current management,easily induces pathogen resistance and environmental pollution,which biological control avoids.This study investigated juniper essential oil’s efficacy against the disease on Mongolian Scots pine(Pinus sylvestris var.mongolica)and its induced resistance mechanisms via pot experiments,physiological assays(defense enzyme activities,resistant substances)and metabolomic sequencing(secondary metabolites).Results showed varied efficacy:three foliar sprays of 10μL mL^(-1) oil achieved the best control phenylalanine ammonia-lyase(PAL),polyphenol oxidase(82.9%).The 20μL mL^(-1) treatment significantly increased(PPO)activities,and contents of lignin,flavonoids and total phenolics.Metabolomic analysis showed 326 upregulated and 527 downregulated different metabolites in essential oilinduced and pathogen-inoculated pines,compared to 483 upregulated and 277 downregulated metabolites in noninduced but inoculated pines.The differentially expressed metabolites in treated pines were primarily enriched in pathways related to amino acid metabolism and plant secondary metabolite biosynthesis,with notably increased expression levels of ferulic acid,scopoletin,pipecolic acid,D-proline,and DL-arginine.Therefore,juniper essential oil protects against D.sapinea by inducing systemic acquired resistance in Mongolian Scots pine.In conclusion,juniper essential oil controls D.sapinea by inducing systemic acquired resistance(SAR)in Mongolian Scots pine,clarifying the molecular mechanism and supporting biological control of the disease.展开更多
While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model...While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model incorporating rate-and-state friction laws to investigate fault reactivation mechanisms during early-stage CO_(2)injection.The competing effects of pore pressure diffusion and fluid pressurization are systematically investigated,considering three key factors:permeability variations within fault damage zones,normal stress variation coefficients,and injection parameters.Numerical simulations reveal that slower CO_(2)migration causes limited pressure perturbation(<0.3 MPa over 15 d)compared to single-phase fluid injection.Fluid pressurization enhances fault strength and delays reactivation,though this stabilizing effect diminishes in low-permeability damage zones.Highly permeable damage zones promote larger rupture areas despite strengthening from pressurization,as reduced effective stress accelerates failure.Paradoxically,while fluid pressurization increases fault strength,it simultaneously elevates seismic risk through amplified stress drops during slip events.Temporal analysis shows that fluid pressurization dominates initial fault response,while sustained pore pressure diffusion ultimately drives reactivation.Increased normal stress variation coefficients and injection rates accelerate localized rupture initiation but restrict propagation due to non-critically stressed states.This discrepancy demonstrates that regions with positive Coulomb failure stress changes do not correlate well with actual slip zones.These findings highlight the critical interplay between transient pressurization effects and progressive pressure diffusion during early CO_(2)injection phases,providing crucial insights for seismic risk management in CO_(2)storage projects.展开更多
Accurate phenological information is essential for measuring ecosystem dynamics and carbon uptake.Southwest China is one of the country's largest terrestrial carbon sink regions and plays a crucial role in carbon ...Accurate phenological information is essential for measuring ecosystem dynamics and carbon uptake.Southwest China is one of the country's largest terrestrial carbon sink regions and plays a crucial role in carbon peaking and neutrality.However,its complex terrain,fragile ecosystem,and variable climate challenge carbon sink stability.Vegetation phenology significantly impacts carbon absorption and release,making accurate phenological data essential for understanding carbon sequestration dynamics.The widespread distribution of evergreen forests and their weak seasonal variation in canopy introduce significant uncertainties in extracting phenology using traditional remote sensing information in this region.These limitations can lead to inaccurate assessments of carbon sink dynamics.Therefore,precise phenology extraction and analysis are vital for improving ecosystem dynamics and the carbon cycle in Southwest China.Firstly,we employed different ways to evaluate the ability of solar-induced chlorophyll fluorescence(SIF)and traditional remote sensing information to extract phenology.Secondly,based on SIF,we analyzed the spatial and temporal changes in the start of the growing season(SOS),the end of the growing season(EOS),and the length of the growing season(LOS)from 2001 to 2020.Finally,we systematically analyzed the response of SOS and EOS to five preseason climatic factors.The results showed that(1)SIF outperformed traditional remote sensing information in extracting phenology.(2)Vegetation phenology exhibited significant spatial heterogeneity.Moreover,SOS,EOS,and LOS showed trends of advancement,delay,and extension both overall and across all vegetation types.(3)Precipitation was the main factor influencing SOS,while surface downward solar radiation and mean temperature were the main factors affecting EOS,and the phenology of different vegetation types showed a great difference in response to preseason climate factors.These findings improve our understanding of vegetation phenology and its dynamics over Southwest China.展开更多
Oncology Research Editorial Office Published:23 March 2026 The published article titled“MicroRNA 125a-5p Inhibits Cell Proliferation and Induces Apoptosis in Hepatitis B Virus-Related Hepatocellular Carcinoma by Down...Oncology Research Editorial Office Published:23 March 2026 The published article titled“MicroRNA 125a-5p Inhibits Cell Proliferation and Induces Apoptosis in Hepatitis B Virus-Related Hepatocellular Carcinoma by Downregulation of ErbB3”has been retracted from Oncology Research,Vol.27,No.4,2019,pp.449-458.DOI:10.3727/096504017X15016337254623 URL:https://www.techscience.com/or/v27n4/48558.展开更多
Microbially induced calcium carbonate precipitation(MICP)is an eco-friendly technology for soil improvement.Although numerous experiments have been conducted to solidify sand foundations using MICP,the mechanisms by w...Microbially induced calcium carbonate precipitation(MICP)is an eco-friendly technology for soil improvement.Although numerous experiments have been conducted to solidify sand foundations using MICP,the mechanisms by which grain interfacial morphologies influencethe MICP process remain unclear.This study utilized 3D-printed flowcells with different boundary morphologies to investigate the effects of interfacial morphologies on the MICP process.CaCO_(3)precipitation characteristics were investigated through microscopic observation and image quantificationanalysis.The results indicate that low flowvelocities near the interface promote bacterial accumulation due to reduced hydrodynamic shear forces.Rough interfaces,compared to smooth ones,enhance bacterial adsorption owing to the larger regions of low flowvelocity,increased surface area,and the formation of local eddies,which promote greater CaCO_(3)precipitation.Compared to the regions away from the interface,a higher abundance of small CaCO_(3)crystals is observed near the interface because of the high urease activity from bacteria and the reduced shear-induced entrainment due to the low flowvelocity.Besides,larger crystals also preferentially precipitate in proximity to interfaces as the low flowvelocity enhances crystal growth according to the particle attachment theory.The presence of rough interfaces further reduces flowvelocities,leading to the precipitation of larger and more densely packed CaCO_(3)crystals.Therefore,rough interfaces promote the microbially induced calcium carbonate precipitation.This work is expected to enhance the understanding of microbially induced calcium carbonate precipitation characteristics on solid surfaces such as soil grains and contribute to the optimization of MICP applications.展开更多
The innate immune system of the central nervous system(CNS),long viewed as primarily microgliadriven,is now increasingly recognized to include astrocytes as active participants in neuroimmune signaling.Chronic alcohol...The innate immune system of the central nervous system(CNS),long viewed as primarily microgliadriven,is now increasingly recognized to include astrocytes as active participants in neuroimmune signaling.Chronic alcohol exposure trigge rs oxidative stress,glial activation,and sustained inflammation,ultimately contributing to cognitive decline and neuronal injury.展开更多
Light element compounds under high pressure display intriguing properties and applications,owing to their diverse bonding patterns and crystalline structures.However,the system of ternary Be-C-O compounds under high p...Light element compounds under high pressure display intriguing properties and applications,owing to their diverse bonding patterns and crystalline structures.However,the system of ternary Be-C-O compounds under high pressure,as the lightest representative of the IIA-IVA-VIA family,remains largely unexplored.Using a machine-learning-accelerated crystal structure search and first-principles calculations,Be-C-O phase diagrams are investigated at pressures ranging from 0 to 100 GPa.Four ternary compounds are proposed to be stable at corresponding pressures:BeCO_(3),Be_(2)CO_(4),Be_(2)C_(4)O_(3),and BeC_(4)O_(2).Analyses of electronic structure and chemical bonding further reveal how the structural diversity of these compounds is induced.Remarkably,Be_(2)C_(4)O_(3) and BeC_(4)O_(2) are recoverable to ambient conditions and possess both high energy density and high hardness.The volumetric energy densities of Be_(2)C_(4)O_(3) and BeC_(4)O_(2) could approach 9.03 and 7.94 kJ/cm^(3),respectively.The Vickers hardnesses of Be_(2)C_(4)O_(3) and BeC_(4)O_(2) are found to be close to 39.58 and 51.57 GPa,respectively.These findings demonstrate the structural and functional diversity of Be-C-O compounds under high pressure,providing guidance for further exploration of the IIA-IVA-VIA compounds.展开更多
The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotro...The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotrophic lateral sclerosis.Motor neurons generated through different strategies may exhibit substantial differences in purity,maturation,characterization,and even neuronal identity,leading to variable outcomes in disease modeling and drug screening.However,very few comparative studies have been conducted to determine the similarities and differences among motor neurons prepared via different protocols.In this study,we prepared human induced pluripotent stem cell-derived motor neurons via lentiviral delivery of transcription factors and chemical induction and performed a systematic comparative analysis.We found that motor neurons generated by both approaches showed typical motor neuron morphology and robustly expressed motor neuron-specific markers,such as nuclear homeobox transcription factor 9 and choline acetyltransferase.The chemical induction protocol utilizes a combination of small molecules to induce motor neuron differentiation,offering a significantly faster maturation time of 35 days compared to 46 days with lentiviral delivery of transcription factors.Additionally,while lentiviral delivery of transcription factors are suitable for downstream biochemical analysis,chemical induction are more applicable for therapeutic approaches as they avoid the use of lentiviruses.Both approaches produce motor neurons with high purity(>95%)and yield.No significant differences were found between chemical induction and lentiviral delivery of transcription factors in terms of motor neuron markers and maturation markers.These robust methodologies offer researchers powerful tools for investigating motor neuron diseases and potential therapeutic strategies.展开更多
Acute eosinophilic pneumonia(AEP) is a pulmonary condition characterized by acute febrile illness and respiratory distress,with bilateral pulmonary infiltrates,particularly eosinophilic infiltration of the lungs.^([1]...Acute eosinophilic pneumonia(AEP) is a pulmonary condition characterized by acute febrile illness and respiratory distress,with bilateral pulmonary infiltrates,particularly eosinophilic infiltration of the lungs.^([1])Amiodarone,a widely applied antiarrhythmic agent,has been reported as a potential cause of drug-induced AEP.^([2]) Most reported cases of amiodarone-induced AEP typically occur following prolonged exposure for two months or more.展开更多
The loss of control over movement is one of the most devastating consequences of Parkinson’s disease(PD).The loss of control largely results from the gradual but inexorable destruction of dopamine-producing neurons i...The loss of control over movement is one of the most devastating consequences of Parkinson’s disease(PD).The loss of control largely results from the gradual but inexorable destruction of dopamine-producing neurons in the substantia nigra pars compacta.As dopamine levels fall,the ability to initiate,control,learn,and sustain actions declines.Treatment with the dopamine precursor levodopa can partly overcome motor impairments;however,years of use often leads to levodopa-induced dyskinesia(LID),a debilitating condition characterized by uncontrolled writhing and ballistic movements,making continued treatment difficult or impossible.While progress has been made towards unraveling the molecular and cellular processes driving the development of LID,far less is known about the changes in ongoing neuronal activity that contribute to LID expression.展开更多
Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells en...Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.展开更多
The metal‐reduction‐induced dechlorination coupling(MR-DC)strategy enables the first successful synthesis of an all‐inorganic crosslinked phosphazene network(aPN)from hexachlorocyclotriphosphazene(HCCP)under mild r...The metal‐reduction‐induced dechlorination coupling(MR-DC)strategy enables the first successful synthesis of an all‐inorganic crosslinked phosphazene network(aPN)from hexachlorocyclotriphosphazene(HCCP)under mild reaction conditions.Using Cu as a model,the resulting Cu-aPN(copper‐embedded all‐inorganic phosphazene network)retains the intrinsic N_(3)P_(3)backbone and exhibits an amorphous structure where Cu species are uniformly anchored at dense P/N coordination sites of the network.Time of flight secondary ion mass spectrometry(TOF‐SIMS)and X‐ray diffraction(XRD)reveal a gradual CuCl‐to‐CuO phase conversion during ammonia treatment,which effectively ensures the structural stability of the phosphazene framework.In 1 M KOH,Cu-aPN delivers an overpotential of 280 mV at 10 mA cm^(−2)and a Tafel slope of 48 mV dec^(−1),markedly outperforming Ga-aPN.In situ Raman and density functional theory(DFT)analyses indicate stronger Cu-P/N coordination coupling that lowers the*OH formation barrier(0.39 vs.0.88 eV for Ga).This MR-DC route furnishes a general and versatile pathway for constructing metal‐embedded all‐inorganic phosphazene frameworks with tunable coordination environments for advanced electrocatalytic applications.展开更多
The plant immunity inducer, amino-oligosaccharin, has remarkable effects in disease resistance, cold tolerance, growth promotion, yield increase and quality improvement. This paper introduced the action mechanism of a...The plant immunity inducer, amino-oligosaccharin, has remarkable effects in disease resistance, cold tolerance, growth promotion, yield increase and quality improvement. This paper introduced the action mechanism of amino-oligosaccharin, its main application effects on crops and application techniques. In 2013-2014, ex- periments were conducted on a variety of crops at multiple locations by Xinjiang Corps as well as popularization and application in 2013-2014, and it was shown by the popularization and application that the application of amino-oligosaccharin could promote plant growth, reduce the incidence of crop diseases and improve crop yield and product quality.展开更多
Because of the complex constraint effects among layers in multi-layered metallic bellows hydroforming,the stress concentration and defects such as wrinkling and fracture may easily occur.It is a key to reveal the defo...Because of the complex constraint effects among layers in multi-layered metallic bellows hydroforming,the stress concentration and defects such as wrinkling and fracture may easily occur.It is a key to reveal the deformation behaviors in order to obtain a sound product.Based on the ABAQUS platform,a 3 D-FE model of the four-layered U-shaped metallic bellow hydroforming process is established and validated by experiment.The stress and strain distributions,wall thickness variations and bellow profiles of each layer in the whole process,including bulging,folding and springback stages,are studied.Then deformation behaviors of bellows under different forming conditions are discussed.It is found that the wall thinning degrees of different layer vary after hydroforming,and is the largest for the inner layer and smallest for the outer layer.At folding stage,the wall thinning degree of the crown point increases lineally,and the difference among layers increases as the process going.The displacements of the crown point decrease from the inner layer to the outer layer.After springback,the U-shaped cross section changes to a tongue shape,the change of convolution pitch is much larger than the change of convolution height,and the springback values of the inner layer are smaller than the outer layer.An increase in the internal pressure and die spacing cause the maximum wall thinning degree and springback increase.With changing of process parameters,bellows with deep convolution are easily encountered wall thinning during hydroforming and convolution distortion after springback.This research is helpful for precision forming of multi-layered bellows.展开更多
U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently c...U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently cause neurological deficits. The majority of surgeons have limited experience in management of U-shaped sacral fractures. No standard treatment protocol for U-shaped sacral fractures has been available till now. This study aimed to examine the management of U-shaped sacral fractures and the early outcomes. Clinical data of 15 consecutive patients with U-shaped sacral fracture who were admitted to our trauma center between 2009 and 2014 were retrospectively analyzed. Demographics, fracture classification, mechanism of injury and operative treatment and deformity angle were assessed. All the patients were treated with lumbopelvic fixation or （and） sacral decompression. EQ-5d score was applied to evaluate the patients＇ quality of life. Of the 15 consecutive patients with U-shaped sacral fracture, the mean age was 28.8 years （range： 15-55 years） at the time of injury. There were 6 females and 9 males. The mean follow- up time was 22.7 months （range： 9-47 months） and mean full weight-bearing time was 9.9 weeks （range： 8-14 weeks）. Ten patients received lumbopelvic fixation and sacral decompression, one lombosacral fixation, and 4 merely sacral decompression due to delayed diagnosis or surgery. The post-operation deformity angle （mean 27.87°, and range： 8°-90°） of the sacrum was smaller than that pre-operation （mean 35.67; range： 15-90） with no significance difference noted. At the latest follow-up, all patients obtained neurological recovery with different extents. Visual analogue score （VAS） was reduced from preoperative 7.07 （range： 5-9） to postoperetive 1.93 （range： 1-3）. All patients could walk without any aid after treatment. Eight patients were able to care for themselves and undertook some daily activities. Five patients had returned to work full time. In conclusion, lumbopelvic fixation is an effective method for stabilization of U-shaped sacral fractures with fewer complications developed. Effective reduction and firm fixation are the prerequisite of early mobilization and neurological recovery. Sacral decompression effectively promotes neurological recovery even in patients with old U-shaped sacral fractures.展开更多
To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature ...To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working fluid.The pressure fluctuations near the tip region were collected,and the cavity structures under various conditions were documented by a high-speed camera.It is found that large tip clearance distinctly reduces both the non-cavitation and cavitation performance.Three cavitation instabilities,super-synchronous rotating cavitation,synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization results.Large tip clearance displays a remarkable stabilization effect on pressure fluctuation,cavitation surge totally disappears,and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance,whereas super-synchronous rotating cavitation only occurs in the large tip clearance.The cavitation areas are smaller at large tip clearance,while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance,which may be responsible for the worse cavitation performance.展开更多
Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape not...Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape notch on the spool, such as mass flow rates, flow coefficients, effiux angles and steady state flow forces under different operating conditions. At last, the reliability of the mathematical model of the flow area for the sloping U-shape notch orifice on the spool was demonstrated by the comparison between the orifice area curve derived and the corresponding experimental data provided by the test. It is presented that the bottom arc of sloping U-shape notch （ABU） should not be omitted when it is required to accurately calculate the orifice area of ABU. Although the theoretical flow area of plain bottom sloping U-shape notch （PBU） is larger than that of ABU at the same opening, the simulated mass flow and experimental flow area of ABU are both larger than these of PBU at the same opening, while the simulated flow force of PBU is larger than that of ABU at the same opening. Therefore, it should be prior to adapt the ABU when designing the spool with proportional character.展开更多
基金supported by Science and Technology Planning Project of Sichuan Province with Grant No.2023YFS0429supported by Science and Technology Project of China Road and Bridge Corporation with Grant No.P2220447+1 种基金supported by Foundation of Xinjiang Institute of Engineering 2024(Grant No.2024xgy072605)also supported by Sichuan Natural Science Foundation Project(Grant No.2024NSFSC0162).
文摘In recent years,tuned liquid dampers(TLDs)have emerged as a focal point of research due to their remarkable potential for structural vibration mitigation.Yet,progress in this field remains constrained by an incomplete understanding of the fundamental mechanisms governing sloshing-induced loads in liquid-filled containers.Aqueducts present a distinctive case,as the capacity of their contained water to function effectively as a TLD remains uncertain.To address this gap,the present study investigates the generation mechanisms of sloshing loads under non-resonant cases through a two-dimensional(2D)computational fluid dynamics(CFD)model developed in ANSYS Fluent.The incompressible Reynolds-Averaged Navier–Stokes(RANS)equations are solved,while the Volume of Fluid(VOF)method captures the evolution of the air–water interface.Turbulent flow behavior is modeled using the RNG-approach.The ensuing results reveal the dynamic characteristics of the horizontal force(fℎ)and the fluctuating component of the vertical force(Fof).Fh is predominantly governed by the inertia of the deep-water region and its phase varies coherently with the aqueduct’s acceleration.With increasing excitation amplitude(A)and frequency(f),the contribution of deep-water inertia to𝐹ℎintensifies markedly,accounting for 82.6–92.1%of the total horizontal load at an excitation amplitude of 0.15 m and frequencies of 1.0–1.6 Hz.The extreme values of Fof arise primarily from asymmetric static pressures induced by free-surface fluctuations,which are further amplified when wall gaps appear at large amplitudes(A≥10 cm)and high frequencies(f≥1.4 Hz).Unlike resonant cases dominated by free-surface resonance,non-resonant sloshing loads are principally driven by deep-water inertia and motion-induced surface asymmetry.
基金supported by Tianjin Science and Technology Planning Project(22YDTPJC0020).
文摘As a core power device in strategic industries such as new energy power generation and electric vehicles,the thermal reliability of IGBT modules directly determines the performance and lifetime of the whole system.A synergistic optimization structure of“inlet plate-channel spoiler columns”is proposed for the local hot spot problem during the operation of Insulated Gate Bipolar Transistor(IGBT),combined with the inherent defect of uneven flow distribution of the traditional U-type liquid cooling plate in this paper.The influences of the shape,height(H),and spacing from the spoiler column(b)of the plate on the comprehensive heat dissipation performance of the liquid cooling plate are analyzed at different Reynolds numbers,A dual heat source strategy is introduced and the effect of the optimized structure is evaluated by the temperature inhomogeneity coefficient(Φ).The results show that the optimum effect is achieved when the shape of the plate is square,H=4.5 mm,b=2 mm,and u=0.05 m/s,at which the HTPE=1.09 and Φ are reduced by 40%.In contrast,the maximum temperatures of the IGBT and the FWD(Free Wheeling Diode)chips are reduced by 8.7 and 8.4 K,respectively,and ΔP rises by only 1.58 Pa while keeping ΔT not significantly increased.This optimized configuration achieves a significant reduction in the critical chip temperature and optimization of the flow field uniformity with almost no change in the system flow resistance.It breaks through the limitation of single structure optimization of the traditional liquid cooling plate and effectively solves the problem of uneven flow in the U-shaped cooling plate,which provides a new solution with important engineering value for the thermal management of IGBT modules.
基金Science and Technology Planning Project of Sichuan Province with Grant No.2023YFS0429supported by Science and Technology Project of China Road and Bridge Corporation with Grant No.P2220447+1 种基金supported by Foundation of Xinjiang Institute of Engineering 2024(Grant No.2024xgy072605)supported by Sichuan Natural Science Foundation Project(Grant No.2024NSFSC0162).The numerical calculations in this study have been done on Hefei advanced computing center.
文摘In recent years,tuned liquid dampers(TLDs)have attracted significant research interest;however,overall progress has been limited due to insufficient understanding of the mechanisms governing sloshing-induced loads.In particular,it remains unclear whether the water in aqueducts—common water-diversion structures in many countries—can serve as an effective TLD.This study investigates the generation mechanisms of sloshing loads during the first-order transverse resonance of water in a U-shaped aqueduct using a two-dimensional(2D)numerical model.The results reveal that,at the equilibrium position,the free surface difference between the left and right walls,the horizontal force on the aqueduct,and the fluctuating component of the vertical force all reach their maxima,with energy predominantly stored as potential energy.At the maximum displacement position,the surface difference and horizontal force drop to zero,while the fluctuating vertical force attains its minimum and energy shifts primarily to kinetic form.At this stage,static pressure is governed solely by the vertical convective acceleration,whereas at equilibrium it is closely linked to both the free surface difference and vertical local acceleration of the water.This dynamic energy exchange generates vertical force oscillations even when the free surface appears nearly symmetric.
基金supported by the National Key R&D Program of China(2022YFD1401005).
文摘Diplodia tip blight,caused by Diplodia sapinea,is a global pine necrotic disease causing heavy economic losses to the pine industry.Chemical control,its main current management,easily induces pathogen resistance and environmental pollution,which biological control avoids.This study investigated juniper essential oil’s efficacy against the disease on Mongolian Scots pine(Pinus sylvestris var.mongolica)and its induced resistance mechanisms via pot experiments,physiological assays(defense enzyme activities,resistant substances)and metabolomic sequencing(secondary metabolites).Results showed varied efficacy:three foliar sprays of 10μL mL^(-1) oil achieved the best control phenylalanine ammonia-lyase(PAL),polyphenol oxidase(82.9%).The 20μL mL^(-1) treatment significantly increased(PPO)activities,and contents of lignin,flavonoids and total phenolics.Metabolomic analysis showed 326 upregulated and 527 downregulated different metabolites in essential oilinduced and pathogen-inoculated pines,compared to 483 upregulated and 277 downregulated metabolites in noninduced but inoculated pines.The differentially expressed metabolites in treated pines were primarily enriched in pathways related to amino acid metabolism and plant secondary metabolite biosynthesis,with notably increased expression levels of ferulic acid,scopoletin,pipecolic acid,D-proline,and DL-arginine.Therefore,juniper essential oil protects against D.sapinea by inducing systemic acquired resistance in Mongolian Scots pine.In conclusion,juniper essential oil controls D.sapinea by inducing systemic acquired resistance(SAR)in Mongolian Scots pine,clarifying the molecular mechanism and supporting biological control of the disease.
基金funded by Joint Funds of the National Natural Science Foundation of China(Grant No.U23A20671)the Major Project of Inner Mongolia Science and Technology(Grant No.2021ZD0034)the Creative Groups of Natural Science Foundation of Hubei Province,China(Grant No.2021CFA030).
文摘While injection-induced seismicity has been widely studied,its implications for CO_(2)geological storage require reevaluation due to distinct fluid-rock interactions.This study develops a coupled hydromechanical model incorporating rate-and-state friction laws to investigate fault reactivation mechanisms during early-stage CO_(2)injection.The competing effects of pore pressure diffusion and fluid pressurization are systematically investigated,considering three key factors:permeability variations within fault damage zones,normal stress variation coefficients,and injection parameters.Numerical simulations reveal that slower CO_(2)migration causes limited pressure perturbation(<0.3 MPa over 15 d)compared to single-phase fluid injection.Fluid pressurization enhances fault strength and delays reactivation,though this stabilizing effect diminishes in low-permeability damage zones.Highly permeable damage zones promote larger rupture areas despite strengthening from pressurization,as reduced effective stress accelerates failure.Paradoxically,while fluid pressurization increases fault strength,it simultaneously elevates seismic risk through amplified stress drops during slip events.Temporal analysis shows that fluid pressurization dominates initial fault response,while sustained pore pressure diffusion ultimately drives reactivation.Increased normal stress variation coefficients and injection rates accelerate localized rupture initiation but restrict propagation due to non-critically stressed states.This discrepancy demonstrates that regions with positive Coulomb failure stress changes do not correlate well with actual slip zones.These findings highlight the critical interplay between transient pressurization effects and progressive pressure diffusion during early CO_(2)injection phases,providing crucial insights for seismic risk management in CO_(2)storage projects.
基金supported by the National Natural Science Foundation of China[Grant NO.42401465 and 42401464]Yunnan Fundamental Research Projects[Grant NO.202501AT070343,202401AU070169 and 202401CF070161]+1 种基金Natural Science Fund of Kunming University of Science and Technology(KKZ3202421125)Yunnan Provincial Talent Project“High-level Talent Training Support Plan”[YNWR-QNBJ-2020-031]。
文摘Accurate phenological information is essential for measuring ecosystem dynamics and carbon uptake.Southwest China is one of the country's largest terrestrial carbon sink regions and plays a crucial role in carbon peaking and neutrality.However,its complex terrain,fragile ecosystem,and variable climate challenge carbon sink stability.Vegetation phenology significantly impacts carbon absorption and release,making accurate phenological data essential for understanding carbon sequestration dynamics.The widespread distribution of evergreen forests and their weak seasonal variation in canopy introduce significant uncertainties in extracting phenology using traditional remote sensing information in this region.These limitations can lead to inaccurate assessments of carbon sink dynamics.Therefore,precise phenology extraction and analysis are vital for improving ecosystem dynamics and the carbon cycle in Southwest China.Firstly,we employed different ways to evaluate the ability of solar-induced chlorophyll fluorescence(SIF)and traditional remote sensing information to extract phenology.Secondly,based on SIF,we analyzed the spatial and temporal changes in the start of the growing season(SOS),the end of the growing season(EOS),and the length of the growing season(LOS)from 2001 to 2020.Finally,we systematically analyzed the response of SOS and EOS to five preseason climatic factors.The results showed that(1)SIF outperformed traditional remote sensing information in extracting phenology.(2)Vegetation phenology exhibited significant spatial heterogeneity.Moreover,SOS,EOS,and LOS showed trends of advancement,delay,and extension both overall and across all vegetation types.(3)Precipitation was the main factor influencing SOS,while surface downward solar radiation and mean temperature were the main factors affecting EOS,and the phenology of different vegetation types showed a great difference in response to preseason climate factors.These findings improve our understanding of vegetation phenology and its dynamics over Southwest China.
文摘Oncology Research Editorial Office Published:23 March 2026 The published article titled“MicroRNA 125a-5p Inhibits Cell Proliferation and Induces Apoptosis in Hepatitis B Virus-Related Hepatocellular Carcinoma by Downregulation of ErbB3”has been retracted from Oncology Research,Vol.27,No.4,2019,pp.449-458.DOI:10.3727/096504017X15016337254623 URL:https://www.techscience.com/or/v27n4/48558.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3707900)National Natural Science Foundation of China(Grant No.42230710,42525201)Key task project for joint research and development of the Yangtze River Delta Science and Technology Innovation Community(Grant No.2022CSJGG1200).
文摘Microbially induced calcium carbonate precipitation(MICP)is an eco-friendly technology for soil improvement.Although numerous experiments have been conducted to solidify sand foundations using MICP,the mechanisms by which grain interfacial morphologies influencethe MICP process remain unclear.This study utilized 3D-printed flowcells with different boundary morphologies to investigate the effects of interfacial morphologies on the MICP process.CaCO_(3)precipitation characteristics were investigated through microscopic observation and image quantificationanalysis.The results indicate that low flowvelocities near the interface promote bacterial accumulation due to reduced hydrodynamic shear forces.Rough interfaces,compared to smooth ones,enhance bacterial adsorption owing to the larger regions of low flowvelocity,increased surface area,and the formation of local eddies,which promote greater CaCO_(3)precipitation.Compared to the regions away from the interface,a higher abundance of small CaCO_(3)crystals is observed near the interface because of the high urease activity from bacteria and the reduced shear-induced entrainment due to the low flowvelocity.Besides,larger crystals also preferentially precipitate in proximity to interfaces as the low flowvelocity enhances crystal growth according to the particle attachment theory.The presence of rough interfaces further reduces flowvelocities,leading to the precipitation of larger and more densely packed CaCO_(3)crystals.Therefore,rough interfaces promote the microbially induced calcium carbonate precipitation.This work is expected to enhance the understanding of microbially induced calcium carbonate precipitation characteristics on solid surfaces such as soil grains and contribute to the optimization of MICP applications.
基金supported by startup funding from UNMC to Dr.PPpartially by the National Institute on Alcohol Abuse and Alcoholism (AA031444 and P50AA030407-5126,Pilot Core grant) to Dr.SS
文摘The innate immune system of the central nervous system(CNS),long viewed as primarily microgliadriven,is now increasingly recognized to include astrocytes as active participants in neuroimmune signaling.Chronic alcohol exposure trigge rs oxidative stress,glial activation,and sustained inflammation,ultimately contributing to cognitive decline and neuronal injury.
基金supported by the National Key R&D Program of China(Grant Nos.2018YFA0703404 and 2017YFA0403704)the National Natural Science Foundation of China(Grant Nos.11774121 and 91745203)the Program for Changjiang Scholars and Innovative Research Team in University(Grant No.IRT_15R23).
文摘Light element compounds under high pressure display intriguing properties and applications,owing to their diverse bonding patterns and crystalline structures.However,the system of ternary Be-C-O compounds under high pressure,as the lightest representative of the IIA-IVA-VIA family,remains largely unexplored.Using a machine-learning-accelerated crystal structure search and first-principles calculations,Be-C-O phase diagrams are investigated at pressures ranging from 0 to 100 GPa.Four ternary compounds are proposed to be stable at corresponding pressures:BeCO_(3),Be_(2)CO_(4),Be_(2)C_(4)O_(3),and BeC_(4)O_(2).Analyses of electronic structure and chemical bonding further reveal how the structural diversity of these compounds is induced.Remarkably,Be_(2)C_(4)O_(3) and BeC_(4)O_(2) are recoverable to ambient conditions and possess both high energy density and high hardness.The volumetric energy densities of Be_(2)C_(4)O_(3) and BeC_(4)O_(2) could approach 9.03 and 7.94 kJ/cm^(3),respectively.The Vickers hardnesses of Be_(2)C_(4)O_(3) and BeC_(4)O_(2) are found to be close to 39.58 and 51.57 GPa,respectively.These findings demonstrate the structural and functional diversity of Be-C-O compounds under high pressure,providing guidance for further exploration of the IIA-IVA-VIA compounds.
基金National Institute of Health(NIH)National Institute of Neurological Disorders and Stroke(NINDS),Nos.NS112910,NS133252(to BD)Department of Defense(DoD)Peer Reviewed Medical Research Program(PRMRP)Discovery Award,No.W81XWH2010186(to BD).
文摘The generation of human induced pluripotent stem cell-derived motor neurons overcomes limited access to human tissues and offers an unprecedented approach to modeling motor neuron diseases such as dystonia and amyotrophic lateral sclerosis.Motor neurons generated through different strategies may exhibit substantial differences in purity,maturation,characterization,and even neuronal identity,leading to variable outcomes in disease modeling and drug screening.However,very few comparative studies have been conducted to determine the similarities and differences among motor neurons prepared via different protocols.In this study,we prepared human induced pluripotent stem cell-derived motor neurons via lentiviral delivery of transcription factors and chemical induction and performed a systematic comparative analysis.We found that motor neurons generated by both approaches showed typical motor neuron morphology and robustly expressed motor neuron-specific markers,such as nuclear homeobox transcription factor 9 and choline acetyltransferase.The chemical induction protocol utilizes a combination of small molecules to induce motor neuron differentiation,offering a significantly faster maturation time of 35 days compared to 46 days with lentiviral delivery of transcription factors.Additionally,while lentiviral delivery of transcription factors are suitable for downstream biochemical analysis,chemical induction are more applicable for therapeutic approaches as they avoid the use of lentiviruses.Both approaches produce motor neurons with high purity(>95%)and yield.No significant differences were found between chemical induction and lentiviral delivery of transcription factors in terms of motor neuron markers and maturation markers.These robust methodologies offer researchers powerful tools for investigating motor neuron diseases and potential therapeutic strategies.
基金supported by the Anhui Provincial Health and Medical Research Project (AHWJ2023A30277)。
文摘Acute eosinophilic pneumonia(AEP) is a pulmonary condition characterized by acute febrile illness and respiratory distress,with bilateral pulmonary infiltrates,particularly eosinophilic infiltration of the lungs.^([1])Amiodarone,a widely applied antiarrhythmic agent,has been reported as a potential cause of drug-induced AEP.^([2]) Most reported cases of amiodarone-induced AEP typically occur following prolonged exposure for two months or more.
基金supported by Arizona Biomedical Research Commission[ADHS18-198846]the National Institute of Health NINDS[R56-NS109608 and R01-NS122805]Davies,Robert and Peyton,Parkinson’s Disease Research Fund to TF.
文摘The loss of control over movement is one of the most devastating consequences of Parkinson’s disease(PD).The loss of control largely results from the gradual but inexorable destruction of dopamine-producing neurons in the substantia nigra pars compacta.As dopamine levels fall,the ability to initiate,control,learn,and sustain actions declines.Treatment with the dopamine precursor levodopa can partly overcome motor impairments;however,years of use often leads to levodopa-induced dyskinesia(LID),a debilitating condition characterized by uncontrolled writhing and ballistic movements,making continued treatment difficult or impossible.While progress has been made towards unraveling the molecular and cellular processes driving the development of LID,far less is known about the changes in ongoing neuronal activity that contribute to LID expression.
基金supported by the National Natural Science Foundation of China,No.32171356(to YW)Self-Support Research Projects of Shihezi University,No.ZZZC2021105(to WJ)+1 种基金Capital Medical University Natural Science Cultivation Fund,No.PYZ23044(to FQM)Beijing Municipal Natural Science Foundation,No.7244410(to JHD)。
文摘Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.
基金financially supported by the National Natural Science Foundation of China(Grant 22205173)the Innovation Capability Support Program of Shaanxi(Grant 2024CX‐GXPT‐12)。
文摘The metal‐reduction‐induced dechlorination coupling(MR-DC)strategy enables the first successful synthesis of an all‐inorganic crosslinked phosphazene network(aPN)from hexachlorocyclotriphosphazene(HCCP)under mild reaction conditions.Using Cu as a model,the resulting Cu-aPN(copper‐embedded all‐inorganic phosphazene network)retains the intrinsic N_(3)P_(3)backbone and exhibits an amorphous structure where Cu species are uniformly anchored at dense P/N coordination sites of the network.Time of flight secondary ion mass spectrometry(TOF‐SIMS)and X‐ray diffraction(XRD)reveal a gradual CuCl‐to‐CuO phase conversion during ammonia treatment,which effectively ensures the structural stability of the phosphazene framework.In 1 M KOH,Cu-aPN delivers an overpotential of 280 mV at 10 mA cm^(−2)and a Tafel slope of 48 mV dec^(−1),markedly outperforming Ga-aPN.In situ Raman and density functional theory(DFT)analyses indicate stronger Cu-P/N coordination coupling that lowers the*OH formation barrier(0.39 vs.0.88 eV for Ga).This MR-DC route furnishes a general and versatile pathway for constructing metal‐embedded all‐inorganic phosphazene frameworks with tunable coordination environments for advanced electrocatalytic applications.
文摘The plant immunity inducer, amino-oligosaccharin, has remarkable effects in disease resistance, cold tolerance, growth promotion, yield increase and quality improvement. This paper introduced the action mechanism of amino-oligosaccharin, its main application effects on crops and application techniques. In 2013-2014, ex- periments were conducted on a variety of crops at multiple locations by Xinjiang Corps as well as popularization and application in 2013-2014, and it was shown by the popularization and application that the application of amino-oligosaccharin could promote plant growth, reduce the incidence of crop diseases and improve crop yield and product quality.
基金the funds of the National Natural Science Foundation of China(No.51875456)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2019JM-450)+3 种基金the Young Talent fund of University Association for Science and Technology in Shaanxi,China(No.20170518)the Key Laboratory of Advanced Manufacture Technology for Automobile Parts(Chongqing University of Technology),Ministry of Education(No.2018KLMT03)Materials Science and Engineering provincial-level superior discipline funding project of Xi'an Shiyou Universitythe Program for Young Innovative Research Team in Xi'an Shiyou University(No.2015QNKYCXTD02)。
文摘Because of the complex constraint effects among layers in multi-layered metallic bellows hydroforming,the stress concentration and defects such as wrinkling and fracture may easily occur.It is a key to reveal the deformation behaviors in order to obtain a sound product.Based on the ABAQUS platform,a 3 D-FE model of the four-layered U-shaped metallic bellow hydroforming process is established and validated by experiment.The stress and strain distributions,wall thickness variations and bellow profiles of each layer in the whole process,including bulging,folding and springback stages,are studied.Then deformation behaviors of bellows under different forming conditions are discussed.It is found that the wall thinning degrees of different layer vary after hydroforming,and is the largest for the inner layer and smallest for the outer layer.At folding stage,the wall thinning degree of the crown point increases lineally,and the difference among layers increases as the process going.The displacements of the crown point decrease from the inner layer to the outer layer.After springback,the U-shaped cross section changes to a tongue shape,the change of convolution pitch is much larger than the change of convolution height,and the springback values of the inner layer are smaller than the outer layer.An increase in the internal pressure and die spacing cause the maximum wall thinning degree and springback increase.With changing of process parameters,bellows with deep convolution are easily encountered wall thinning during hydroforming and convolution distortion after springback.This research is helpful for precision forming of multi-layered bellows.
文摘U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently cause neurological deficits. The majority of surgeons have limited experience in management of U-shaped sacral fractures. No standard treatment protocol for U-shaped sacral fractures has been available till now. This study aimed to examine the management of U-shaped sacral fractures and the early outcomes. Clinical data of 15 consecutive patients with U-shaped sacral fracture who were admitted to our trauma center between 2009 and 2014 were retrospectively analyzed. Demographics, fracture classification, mechanism of injury and operative treatment and deformity angle were assessed. All the patients were treated with lumbopelvic fixation or （and） sacral decompression. EQ-5d score was applied to evaluate the patients＇ quality of life. Of the 15 consecutive patients with U-shaped sacral fracture, the mean age was 28.8 years （range： 15-55 years） at the time of injury. There were 6 females and 9 males. The mean follow- up time was 22.7 months （range： 9-47 months） and mean full weight-bearing time was 9.9 weeks （range： 8-14 weeks）. Ten patients received lumbopelvic fixation and sacral decompression, one lombosacral fixation, and 4 merely sacral decompression due to delayed diagnosis or surgery. The post-operation deformity angle （mean 27.87°, and range： 8°-90°） of the sacrum was smaller than that pre-operation （mean 35.67; range： 15-90） with no significance difference noted. At the latest follow-up, all patients obtained neurological recovery with different extents. Visual analogue score （VAS） was reduced from preoperative 7.07 （range： 5-9） to postoperetive 1.93 （range： 1-3）. All patients could walk without any aid after treatment. Eight patients were able to care for themselves and undertook some daily activities. Five patients had returned to work full time. In conclusion, lumbopelvic fixation is an effective method for stabilization of U-shaped sacral fractures with fewer complications developed. Effective reduction and firm fixation are the prerequisite of early mobilization and neurological recovery. Sacral decompression effectively promotes neurological recovery even in patients with old U-shaped sacral fractures.
基金supported by the National Basic Research Program of China(No.613321)。
文摘To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working fluid.The pressure fluctuations near the tip region were collected,and the cavity structures under various conditions were documented by a high-speed camera.It is found that large tip clearance distinctly reduces both the non-cavitation and cavitation performance.Three cavitation instabilities,super-synchronous rotating cavitation,synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization results.Large tip clearance displays a remarkable stabilization effect on pressure fluctuation,cavitation surge totally disappears,and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance,whereas super-synchronous rotating cavitation only occurs in the large tip clearance.The cavitation areas are smaller at large tip clearance,while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance,which may be responsible for the worse cavitation performance.
基金Project(51004085)supported by the National Natural Science Foundation of China
文摘Precise function expression of the flow area for the sloping U-shape notch orifice versus the spool stroke was derived. The computational fluid dynamics was used to analyze the flow features of the sloping U-shape notch on the spool, such as mass flow rates, flow coefficients, effiux angles and steady state flow forces under different operating conditions. At last, the reliability of the mathematical model of the flow area for the sloping U-shape notch orifice on the spool was demonstrated by the comparison between the orifice area curve derived and the corresponding experimental data provided by the test. It is presented that the bottom arc of sloping U-shape notch （ABU） should not be omitted when it is required to accurately calculate the orifice area of ABU. Although the theoretical flow area of plain bottom sloping U-shape notch （PBU） is larger than that of ABU at the same opening, the simulated mass flow and experimental flow area of ABU are both larger than these of PBU at the same opening, while the simulated flow force of PBU is larger than that of ABU at the same opening. Therefore, it should be prior to adapt the ABU when designing the spool with proportional character.
