Enhancing the fermentation efficiency of waste in waste warehouses is pivotal for accelerating the pyrolysis process and minimizing harmful gas emissions.This study proposes an integrated approach,combining hot air in...Enhancing the fermentation efficiency of waste in waste warehouses is pivotal for accelerating the pyrolysis process and minimizing harmful gas emissions.This study proposes an integrated approach,combining hot air injection with dual atomizing nozzles,for the thermal treatment of waste piles.Numerical simulations are employed to investigate the influence of various parameters,namely,nozzle height,nozzle tilt angle,inlet air velocity and air temperature,on the droplet diffusion process,spread area,droplet temperature,and droplet size distribution.The results show that reducing the nozzle height increases the temperature of droplets upon their deposition on the waste pile.Specifically,when the nozzle height is lowered to 1.5 m,the temperature of the droplets reaching the waste pile is 1℃higher than when the nozzle height is set at 2 m.Furthermore,an increase in the nozzle tilt angle expands the overlapping heating area.For instance,when the nozzle angle is increased from 15°to 30°,the overlapping spread area expands by 3.21 m2.Additionally,increasing the inlet air velocity enhances the droplet diffusion range.At an air velocity of 2 m/s,the droplet diffusion range grows to 14.4 m,representing a 6.7%increase compared to the nowind condition.While the average droplet diameter decreases to 1.53 mm,the droplet temperature decreases by 1℃.Moreover,the droplet temperature is found to become smaller as the ambient temperature inside the waste warehouse declines.Specifically,a 5℃reduction in the ambient temperature results in a 1℃decrease in the average temperature of the atomized droplets.The study concludes that a nozzle height of 1.5 m and a nozzle tilt angle of 30°effectively meet practical heating requirements.展开更多
BACKGROUND： Latest researches at home and abroad indicate that glycerol trinitrate plays its function because it can metabolize into nitrogen monoxide （NO） in vivo. OBJECTIVE： To study the therapeutic effects of N...BACKGROUND： Latest researches at home and abroad indicate that glycerol trinitrate plays its function because it can metabolize into nitrogen monoxide （NO） in vivo. OBJECTIVE： To study the therapeutic effects of NO vector of ultrasonic atomizing inhalation on vertebro-basilar artery insufficiency （VBI） through transcranial Doppler （TCD） detection and serum NO content and indirect effect of TCD on cerebral blood flow changes. DESIGN： Randomized grouping and controlled clinical study. SETTING： Department of Neurology, the Fourth People＇s Hospital of Jinan. PARTICIPANTS： A total of 130 patients who were diagnosed as VBI were selected from Department of Neurology, the Fourth People＇s Hospital of Jinan from December 2001 to December 2005. The involved inpatients were checked by CT and MRI, and met the VBI diagnostic standard enacted by the Fourth National Academic Meeting of Cerebrovascular Disease in 1995. All patients and their relatives provided the confumed consent. They were randomly divided into low-dose treatment group （n =60）, high-lose treatment group （n =30） and control group （n =40）. METHODS： Patients in the low-dose and high-dose treatment groups were given ultrasonic atomizing inhalation of 3 mg and 5 mg glycerol trinitrate, respectively, for 20 minutes, once a day. In addition, ligustrazine and energy mixture were used once a day for three days in a course. Cases in the control group were only given ligustrazine and energy mixture. All selected cases accepted TCD, blood NO content was checked at the time of beginning, after the first time and after a period of treatment. According to the TCD test, VBI patients were divided into two groups （high-low flow velocity）. The vertebral artery （VA） and basal artery （BA） of left or right sides were detected by 2 Hz detector via occipital window. MAIN OUTCOME MEASURES： ①Blood flow velocity of systolic phase, blood flow velocity of diastole phase and vascular resistance in left and right VA and BA detected by using TCD before treatment, after treatment for one course; ②content of serum NO indirectly measured by using nitric acid disoxidation technique. RESULTS： All 130 VBI patients were involved in the final analysis. ①Changes of hemodynamic indexes： Systolic phase of VA and diastole phase of BA were higher in low-dose treatment group than that in the control group after first treatment, and there was significant difference （P 〈 0.05）; meanwhile, systolic phase and diastole phase of VA and systolic phase of BA were also higher in treatment group than that in the control group after one course （P 〈 0.05）. However, both systolic phase and diastole phase of VA and BA were lower in high-dose treatment group than that in the control group after first treatment and one course, and there was significant difference （P 〈 0.05）. ②Content of serum NO： After first treatment, there was no significant difference between low-dose treatment group and high-dose treatment group （P 〉 0.05）; but both groups were higher than control group, and there was significant difference （P 〈 0.05, 0.01）. CONCLUSION： NO vector of ultrasonic atomizing inhalation can improve VBI so as to improve cerebral blood-supply state.展开更多
A finite element method (FEM) procedure was developed in order to simulatethe quenching process for drilling pipe (DP). The calculating model was based ontime-temperature-transformation (TTT) diagrams, and incorporate...A finite element method (FEM) procedure was developed in order to simulatethe quenching process for drilling pipe (DP). The calculating model was based ontime-temperature-transformation (TTT) diagrams, and incorporated with material properties dependenton temperature. The procedure was used to calculate the temperature-time histories, describe thephase transformations of atomizing spray quenching for DP in the welding zone, and predict thehardness distribution in radius direction after quenching in the zone. The calculated results metwell with that of experiments. It was easy to determine the parameters such as volume and pressureof the cooling water and compressed gas by use of the numerical calculation and experiments, becausethe value of convection coefficient was decided greatly by the mixture of the cooling water andcompressed gas. Moreover, the simulating results were helpful not only to design the quenchingequipment, but also to optimize the quenching process for DP's welding zone.展开更多
Aiming at the problem of air-cooled condenser output limit, a spray humidification system was presented to reduce the inlet air temperature. The pressure atomizing nozzle TF8 was chosen for inlet air spray cooling, an...Aiming at the problem of air-cooled condenser output limit, a spray humidification system was presented to reduce the inlet air temperature. The pressure atomizing nozzle TF8 was chosen for inlet air spray cooling, and the spray cooling experiment with different layouts of nozzles were conducted. Through heat and mass transfer analysis, the cooling effect fitting correlation was acquired with evaporative cooling being the major cooling mechanism. The experimental results under different nozzle layouts show that when the product of dry ball and wet ball temperature difference and spray rate is smaller than 75 ~C-m3/h, opening the TF8 nozzles in row 1 and row 2 （row distance is 500 mm） has better cooling effect than those in row 1 and row 3 （row distance is 1 000 mm）, while when the product is larger than 75 ~C＇m3/h, opening the TF8 nozzles in row 1 and row 3 is superior in cooling effect to those in row 1 and row 2.展开更多
A Computational Fluid Dynamics Software was used to calculate the atomizing gas fields generated by a self-designed atomizer and to analyze the effects of key atomizing variables such as gas pressure and protrusion le...A Computational Fluid Dynamics Software was used to calculate the atomizing gas fields generated by a self-designed atomizer and to analyze the effects of key atomizing variables such as gas pressure and protrusion length of delivery tube on the gas flow state at the tip of or inside the delivery tube. Increasing the length of delivery tube to a certain extent, the eddy flow region with positive pressure moves away from the tip of delivery tube, which is favorable to achieve the effective atomization of the melt.展开更多
Objective: to analyze the effect of nursing intervention for inhalation of aerosolized acute chronic pharyngitis. Methods: 73 patients with acute and chronic pharyngitis were randomly divided into two groups, 36 cases...Objective: to analyze the effect of nursing intervention for inhalation of aerosolized acute chronic pharyngitis. Methods: 73 patients with acute and chronic pharyngitis were randomly divided into two groups, 36 cases in the control group and 37 cases in the study group. Results: the total efficiency of the study group was significantly higher than that of the control group (P<0.05). Conclusion: the reasonable nursing intervention can accelerate the recovery of patients with acute and chronic pharyngitis by atomizing inhalation, which is worth popularizing.展开更多
In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale in...In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale inequalities of mixed quasi-martingale Hardy spaces.Moreover,we furnish sufficient conditions for the boundedness ofσ-sublinear operators in these spaces.These findings extend the existing conclusions regarding mixed quasi-martingale Hardy spaces defined with the help of the mixed L_(p)-norm.展开更多
Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom a...Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom arrays,scalability is primarily constrained by the capacity to generate large numbers of optical tweezers,and conventional techniques using acousto-optic deflectors or spatial light modulators struggle to produce arrays much beyond∼10,000 tweezers.Moreover,these methods require additional microscope objectives to focus the light into micrometer-sized spots,which further complicates system integration and scalability.Here,we demonstrate the experimental generation of an optical tweezer array containing 280×280 spots using a metasurface,nearly an order of magnitude more than most existing systems.The metasurface leverages a large number of subwavelength phase-control pixels to engineer the wavefront of the incident light,enabling both large-scale tweezer generation and direct focusing into micron-scale spots without the need for a microscope.This result shifts the scalability bottleneck for atom arrays from the tweezer generation hardware to the available laser power.Furthermore,the array shows excellent intensity uniformity exceeding 90%,making it suitable for homogeneous single-atom loading and paving the way for trapping arrays of more than 10,000 atoms in the near future.展开更多
Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturiza...Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturization.In particular,the spin-exchange relaxation-free(SERF)atomic gyroscope relies on optical pumping to polarize atoms,enabling rotation sensing through the Faraday optical rotation angle(FORA).However,fluctuations in atomic density introduce systematic errors in FORA measurements,limiting long-term stability.We present a data-driven decoupling method that isolates atomic density fluctuations from the FORA signal by modeling spatially resolved light absorption in the vapor cell.The model accounts for the spatial distribution of spin polarization in the pump-light interaction volume,density-dependent relaxation rates,wall-induced relaxation,and polarization diffusion,and is implemented within a finite-element framework.Compared to the conventional Lambert-Beer law,which assumes one-dimensional homogeneity,our approach captures the full threedimensional density and polarization distribution,significantly improving the accuracy of light absorption modeling.The resulting absorption-density maps are used to train a feedforward neural network,yielding a high-precision estimator for atomic density fluctuations.This estimator enables the construction of a decoupling equation that separates the density contribution from the FORA signal.Experimental validation shows that this method improves the bias instability atσ(100 s)of the gyroscope was improved by 73.1%compared to traditional platinum-resistance-based stabilization.The proposed framework is general and can be extended to other optical pumping-based sensors,such as optically pumped magnetometers.展开更多
We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and...We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and tested using X-ray diffraction(XRD),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM),respectively.The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples.Among the compositions studied,the Co_(45)Pt_(55)sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10^(5) A/m is achieved.The morphology and microstructure of the nanoparticles were analyzed by TEM images,indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles.展开更多
Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the effica...Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.展开更多
The development of catalytic multicomponent reactions for constructing complex organic scaffolds from readily accessible commodity chemicals is a key pursuit in contemporary synthetic chemistry.Current methods for syn...The development of catalytic multicomponent reactions for constructing complex organic scaffolds from readily accessible commodity chemicals is a key pursuit in contemporary synthetic chemistry.Current methods for synthesizing thioesters primarily rely on the acylation of thiols,which produces substantial waste and requires malodorous,unstable sulfur sources.In this work,we introduce a photocatalyzed hydrogen transfer strategy that enables a three-component synthesis of thioesters using abundant primary alcohols,easily available alkenes and elemental sulfur under mild conditions.This protocol demonstrates broad applicability and high chemo-and regioselectivity for both primary alcohols and alkenes,highlighting the advantage and potential of photo-mediated hydrogen transfer in facilitating multicomponent reactions using primary alcohol and elemental sulfur feedstocks.展开更多
The development of catalysts with highly efficient oxygen evolution performance and low-Ir loading is key to scaling up the application of proton exchange membrane(PEM)water electrolysis technology.Here,an Ir-skin cat...The development of catalysts with highly efficient oxygen evolution performance and low-Ir loading is key to scaling up the application of proton exchange membrane(PEM)water electrolysis technology.Here,an Ir-skin catalyst(Ir@KM)is realized on a potassium-manganese oxide(K_(0.25)MnO_(x)(KM))using an ion-exchange method.The Ir-skin over the prepared Ir@KM has a low Ir-Ir atomic distance,endowing an energetically favorable oxide path mechanism to allow a low theoretical overpotential of 0.13 V.Ir@KM offers a low overpotential of~280 mV at a current density of 10 mA cm^(-2)and provides a high mass activity of up to 18,500 A at a cell voltage of 1.8 V in PEM,which is 17.6 times higher than that of IrO_(2),demonstrating a significant advantage in reducing the cost of the membrane electrode.The presented Ir-skin concept represents a promising strategy to fabricate low-Ir catalyst with high activity and durability for practical applications of PEM.展开更多
Ice premelting,the formation of a quasi-liquid layer on ice surfaces below the bulk melting point,plays a crucial role in various processes,ranging from glacier dynamics to ice friction and surface chemistry.Despite i...Ice premelting,the formation of a quasi-liquid layer on ice surfaces below the bulk melting point,plays a crucial role in various processes,ranging from glacier dynamics to ice friction and surface chemistry.Despite intensive research,the microscopic structure of the premelting layer and underlying molecular mechanisms remain poorly understood.In this work,we studied the temperature-and pressure-dependent structural disordering of crystalline Ih(0001)surface near the onset of premelting on the atomic scale by qPlus-based cryogenic atomic force microscopy.The linear correlation between the density of planar local structure(PLS)and the fraction of disordered surface region showed that the PLS mediated early-stage premelting by serving as a metastable seeding state.Notably,the associated surface disordering is cooperative,extending over an area of roughly~2 nm^(2) around a PLS.We further found a striking structural similarity between the kinetic-trapped regime below the surface crystallization temperature(T_(c))and the premelting-dominated regime above T_(c).As the deposition pressure increased,the characteristic temperature dependence was preserved,with only T_(c) shifting to higher values due to kinetic effects.Finally,we proposed a surface phase diagram for ice Ih(0001)based on our experimental observations.展开更多
Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibite...Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibited very high performance in peroxymonosulfate activation.The Fe single-atom filled an N vacancy on the triazine ring edge of C_(3)N_(4),as confirmed through X-ray absorption fine structure,density functional calculation and elec-tron paramagnetic resonance.The SAFe_(0.4)–C_(3)N_(4)/PMS system could completely remove phenol(20 mg/L)within 10 min and its first-order kinetic constant was 12.3 times that of the Fe_(3)O_(4)/PMS system.Under different ini-tial pH levels and in various anionic environments,SAFe_(0.4)–C_(3)N_(4) still demonstrated excellent catalytic activity,achieving a removal rate of over 90%for phenol within 12 min.In addition,SAFe_(0.4)–C_(3)N_(4) exhibited outstanding selectivity in reaction systems with different pollutants,showing excellent degradation effects on electron-rich pollutants only.Hydroxyl radicals(•OH),singlet oxygen(1O_(2))and high-valent iron oxide(Fe(Ⅳ)=O)were de-tected in the SAFe_(0.4)–C_(3)N_(4)/PMS system through free radical capture experiments.Further experiments on the quenching of active species and a methyl phenyl sulfoxide probe confirmed that 1O_(2) and Fe(Ⅳ)=O played dom-inant roles.Additionally,the change in the current response after adding PMS and phenol in succession proved that a direct electron transfer path between organic matter and the catalyst surface was unlikely to exist in the SAFe_(0.4)–C_(3)N_(4)/PMS/Phenol degradation system.This study provides a new demonstration of the catalytic mech-anism of single-atom catalysts.展开更多
The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulat...The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulate the electronic structure of MoS_(2),thereby obtaining a multifunctional catalyst that serves as an efficient sulfur host.The W/V dual single-atomdoped MoS_(2)grown on carbon nanofibers(CMWVS)demonstrates a strong adsorption ability for lithium polysulfides,suppressing the shuttle effects.Additionally,the doping process also results in the phase transition from 2H-MoS_(2)to 1T-MoS_(2)and generates sufficient edge sulfur atoms,promoting the charge/electron transfer and enriching the reaction sites.All these merits contribute to the superior conversion reaction kinetics,leading to the outstanding Li-S battery performance.When fabricated as cathodes by compositing with sulfur,the CMWVS/S cathode delivers a high capacity of 1481.7 mAh g^(-1)at 0.1 C(1 C=1672 mAh g^(-1))and maintains 816.3 m Ah g^(-1)after 1000 cycles at 1.0 C,indicating outstanding cycling stability.Even under a high sulfur loading of 7.9 mg cm^(-2)and lean electrolyte conditions(E/S ratio of 9.0μL mg^(-1)),the cathode achieves a high areal capacity of 8.2 m Ah cm^(-2),showing great promise for practical Li-S battery applications.This work broadens the scope of doping strategies in transition-metal dichalcogenides by tailoring their electronic structures,providing insightful direction for the rational development of high-efficiency electrocatalysts for advanced Li-S battery applications.展开更多
A visible-light-induced synergistic hydrogen atom transfer(HAT)and proton transfer(PT)catalysis was developed for the defluorinative carboxylation of α-CF_(2)R-substituted alkenes.This system affords a variety of γ,...A visible-light-induced synergistic hydrogen atom transfer(HAT)and proton transfer(PT)catalysis was developed for the defluorinative carboxylation of α-CF_(2)R-substituted alkenes.This system affords a variety of γ,γ-difluoro-and γ-monofluoro-vinylacetic acids without stepwise acidification,exhibiting good functional group tolerance,broad scope,and facile scalability.Mechanism studies support that thiol plays the role of the hydrogen relay,which s a hydrogen atom through HAT and then outputs a proton via PT.This strategy also takes full advantage of formate for photocatalytic carboxylation reaction in a step-and atomeconomical way.展开更多
文摘Enhancing the fermentation efficiency of waste in waste warehouses is pivotal for accelerating the pyrolysis process and minimizing harmful gas emissions.This study proposes an integrated approach,combining hot air injection with dual atomizing nozzles,for the thermal treatment of waste piles.Numerical simulations are employed to investigate the influence of various parameters,namely,nozzle height,nozzle tilt angle,inlet air velocity and air temperature,on the droplet diffusion process,spread area,droplet temperature,and droplet size distribution.The results show that reducing the nozzle height increases the temperature of droplets upon their deposition on the waste pile.Specifically,when the nozzle height is lowered to 1.5 m,the temperature of the droplets reaching the waste pile is 1℃higher than when the nozzle height is set at 2 m.Furthermore,an increase in the nozzle tilt angle expands the overlapping heating area.For instance,when the nozzle angle is increased from 15°to 30°,the overlapping spread area expands by 3.21 m2.Additionally,increasing the inlet air velocity enhances the droplet diffusion range.At an air velocity of 2 m/s,the droplet diffusion range grows to 14.4 m,representing a 6.7%increase compared to the nowind condition.While the average droplet diameter decreases to 1.53 mm,the droplet temperature decreases by 1℃.Moreover,the droplet temperature is found to become smaller as the ambient temperature inside the waste warehouse declines.Specifically,a 5℃reduction in the ambient temperature results in a 1℃decrease in the average temperature of the atomized droplets.The study concludes that a nozzle height of 1.5 m and a nozzle tilt angle of 30°effectively meet practical heating requirements.
文摘BACKGROUND： Latest researches at home and abroad indicate that glycerol trinitrate plays its function because it can metabolize into nitrogen monoxide （NO） in vivo. OBJECTIVE： To study the therapeutic effects of NO vector of ultrasonic atomizing inhalation on vertebro-basilar artery insufficiency （VBI） through transcranial Doppler （TCD） detection and serum NO content and indirect effect of TCD on cerebral blood flow changes. DESIGN： Randomized grouping and controlled clinical study. SETTING： Department of Neurology, the Fourth People＇s Hospital of Jinan. PARTICIPANTS： A total of 130 patients who were diagnosed as VBI were selected from Department of Neurology, the Fourth People＇s Hospital of Jinan from December 2001 to December 2005. The involved inpatients were checked by CT and MRI, and met the VBI diagnostic standard enacted by the Fourth National Academic Meeting of Cerebrovascular Disease in 1995. All patients and their relatives provided the confumed consent. They were randomly divided into low-dose treatment group （n =60）, high-lose treatment group （n =30） and control group （n =40）. METHODS： Patients in the low-dose and high-dose treatment groups were given ultrasonic atomizing inhalation of 3 mg and 5 mg glycerol trinitrate, respectively, for 20 minutes, once a day. In addition, ligustrazine and energy mixture were used once a day for three days in a course. Cases in the control group were only given ligustrazine and energy mixture. All selected cases accepted TCD, blood NO content was checked at the time of beginning, after the first time and after a period of treatment. According to the TCD test, VBI patients were divided into two groups （high-low flow velocity）. The vertebral artery （VA） and basal artery （BA） of left or right sides were detected by 2 Hz detector via occipital window. MAIN OUTCOME MEASURES： ①Blood flow velocity of systolic phase, blood flow velocity of diastole phase and vascular resistance in left and right VA and BA detected by using TCD before treatment, after treatment for one course; ②content of serum NO indirectly measured by using nitric acid disoxidation technique. RESULTS： All 130 VBI patients were involved in the final analysis. ①Changes of hemodynamic indexes： Systolic phase of VA and diastole phase of BA were higher in low-dose treatment group than that in the control group after first treatment, and there was significant difference （P 〈 0.05）; meanwhile, systolic phase and diastole phase of VA and systolic phase of BA were also higher in treatment group than that in the control group after one course （P 〈 0.05）. However, both systolic phase and diastole phase of VA and BA were lower in high-dose treatment group than that in the control group after first treatment and one course, and there was significant difference （P 〈 0.05）. ②Content of serum NO： After first treatment, there was no significant difference between low-dose treatment group and high-dose treatment group （P 〉 0.05）; but both groups were higher than control group, and there was significant difference （P 〈 0.05, 0.01）. CONCLUSION： NO vector of ultrasonic atomizing inhalation can improve VBI so as to improve cerebral blood-supply state.
文摘A finite element method (FEM) procedure was developed in order to simulatethe quenching process for drilling pipe (DP). The calculating model was based ontime-temperature-transformation (TTT) diagrams, and incorporated with material properties dependenton temperature. The procedure was used to calculate the temperature-time histories, describe thephase transformations of atomizing spray quenching for DP in the welding zone, and predict thehardness distribution in radius direction after quenching in the zone. The calculated results metwell with that of experiments. It was easy to determine the parameters such as volume and pressureof the cooling water and compressed gas by use of the numerical calculation and experiments, becausethe value of convection coefficient was decided greatly by the mixture of the cooling water andcompressed gas. Moreover, the simulating results were helpful not only to design the quenchingequipment, but also to optimize the quenching process for DP's welding zone.
基金National Key Technologies R&D Program in the 12th Five-Year Plan of China(No. 2011BAJ08B09)
文摘Aiming at the problem of air-cooled condenser output limit, a spray humidification system was presented to reduce the inlet air temperature. The pressure atomizing nozzle TF8 was chosen for inlet air spray cooling, and the spray cooling experiment with different layouts of nozzles were conducted. Through heat and mass transfer analysis, the cooling effect fitting correlation was acquired with evaporative cooling being the major cooling mechanism. The experimental results under different nozzle layouts show that when the product of dry ball and wet ball temperature difference and spray rate is smaller than 75 ~C-m3/h, opening the TF8 nozzles in row 1 and row 2 （row distance is 500 mm） has better cooling effect than those in row 1 and row 3 （row distance is 1 000 mm）, while when the product is larger than 75 ~C＇m3/h, opening the TF8 nozzles in row 1 and row 3 is superior in cooling effect to those in row 1 and row 2.
文摘A Computational Fluid Dynamics Software was used to calculate the atomizing gas fields generated by a self-designed atomizer and to analyze the effects of key atomizing variables such as gas pressure and protrusion length of delivery tube on the gas flow state at the tip of or inside the delivery tube. Increasing the length of delivery tube to a certain extent, the eddy flow region with positive pressure moves away from the tip of delivery tube, which is favorable to achieve the effective atomization of the melt.
文摘Objective: to analyze the effect of nursing intervention for inhalation of aerosolized acute chronic pharyngitis. Methods: 73 patients with acute and chronic pharyngitis were randomly divided into two groups, 36 cases in the control group and 37 cases in the study group. Results: the total efficiency of the study group was significantly higher than that of the control group (P<0.05). Conclusion: the reasonable nursing intervention can accelerate the recovery of patients with acute and chronic pharyngitis by atomizing inhalation, which is worth popularizing.
基金Supported by the National Natural Science Foundation of China(11871195)。
文摘In this article,we conduct a study on mixed quasi-martingale Hardy spaces that are defined by means of the mixed L_(p)-norm.By utilizing Doob’s inequalities,we explore the atomic decomposition and quasi-martingale inequalities of mixed quasi-martingale Hardy spaces.Moreover,we furnish sufficient conditions for the boundedness ofσ-sublinear operators in these spaces.These findings extend the existing conclusions regarding mixed quasi-martingale Hardy spaces defined with the help of the mixed L_(p)-norm.
基金supported by the National Natural Science Foundation of China (Grant No.92576208)Tsinghua University Initiative Scientific Research Program+1 种基金Beijing Science and Technology Planning ProjectTsinghua University Dushi Program。
文摘Scalability remains a major challenge in building practical fault-tolerant quantum computers.Currently,the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands.In atom arrays,scalability is primarily constrained by the capacity to generate large numbers of optical tweezers,and conventional techniques using acousto-optic deflectors or spatial light modulators struggle to produce arrays much beyond∼10,000 tweezers.Moreover,these methods require additional microscope objectives to focus the light into micrometer-sized spots,which further complicates system integration and scalability.Here,we demonstrate the experimental generation of an optical tweezer array containing 280×280 spots using a metasurface,nearly an order of magnitude more than most existing systems.The metasurface leverages a large number of subwavelength phase-control pixels to engineer the wavefront of the incident light,enabling both large-scale tweezer generation and direct focusing into micron-scale spots without the need for a microscope.This result shifts the scalability bottleneck for atom arrays from the tweezer generation hardware to the available laser power.Furthermore,the array shows excellent intensity uniformity exceeding 90%,making it suitable for homogeneous single-atom loading and paving the way for trapping arrays of more than 10,000 atoms in the near future.
基金supported by the Beijing Natural Science Foundation(Grant No.3252013)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300402)+1 种基金the National Natural Science Foundation of China(Grant No.61673041)Key Area Research and Development Program of Guangdong Province(Grant No.2021B0101410005)。
文摘Atomic spin gyroscopes are promising candidates for next-generation inertial navigation due to extremely high theoretical precision,relatively small size among atomic gyroscopes,and promising potential for miniaturization.In particular,the spin-exchange relaxation-free(SERF)atomic gyroscope relies on optical pumping to polarize atoms,enabling rotation sensing through the Faraday optical rotation angle(FORA).However,fluctuations in atomic density introduce systematic errors in FORA measurements,limiting long-term stability.We present a data-driven decoupling method that isolates atomic density fluctuations from the FORA signal by modeling spatially resolved light absorption in the vapor cell.The model accounts for the spatial distribution of spin polarization in the pump-light interaction volume,density-dependent relaxation rates,wall-induced relaxation,and polarization diffusion,and is implemented within a finite-element framework.Compared to the conventional Lambert-Beer law,which assumes one-dimensional homogeneity,our approach captures the full threedimensional density and polarization distribution,significantly improving the accuracy of light absorption modeling.The resulting absorption-density maps are used to train a feedforward neural network,yielding a high-precision estimator for atomic density fluctuations.This estimator enables the construction of a decoupling equation that separates the density contribution from the FORA signal.Experimental validation shows that this method improves the bias instability atσ(100 s)of the gyroscope was improved by 73.1%compared to traditional platinum-resistance-based stabilization.The proposed framework is general and can be extended to other optical pumping-based sensors,such as optically pumped magnetometers.
基金Funded by the National Natural Science Foundation of China(No.52371169)。
文摘We prepared Co_(x)Pt_(100-x)(x=40,45,50,55,60)nanoparticles by the sol-gel method.The phase composition and crystal structure,morphology and microstructure,and magnetic properties of the samples were characterized and tested using X-ray diffraction(XRD),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM),respectively.The results demonstrate that the coercivity of CoPt nanoparticles can be effectively controlled by adjusting the atomic ratio of Co and Pt in the samples.Among the compositions studied,the Co_(45)Pt_(55)sample synthesized by the sol-gel method exhibits smaller grain size and a coercivity as high as 6.65×10^(5) A/m is achieved.The morphology and microstructure of the nanoparticles were analyzed by TEM images,indicating that a slight excess of Pt can effectively enhance the coercivity of CoPt nanoparticles.
基金supported by the National Key R&D Program of China(2021YFA1502802)the National Natural Science Foundation of China(U21B2092,22202213,22402210,22502215,22502214,22572200,and 22579171)+4 种基金the International Partnership Program of Chinese Academy of Sciences(172GJHZ2022028MI)the Shenyang Bureau of Science and Technology(24-213-3-25)the Natural Science Foundation of Liaoning Province(2025BS0153)Zhongke Technology Achievement Transfer and Transformation Center of Henan Province 2025119The XAS experiments were conducted in Beijing Synchrotron Radiation Facility(BSRF)and Shanghai Synchrotron Radiation Facility(SSRF).
文摘Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.
基金National Natural Science Foundation of China (Nos.22071185 and 22271224)the Fundamental Research Funds for the Central Universities (No.2042019kf0008)Wuhan University startup funding for financial support。
文摘The development of catalytic multicomponent reactions for constructing complex organic scaffolds from readily accessible commodity chemicals is a key pursuit in contemporary synthetic chemistry.Current methods for synthesizing thioesters primarily rely on the acylation of thiols,which produces substantial waste and requires malodorous,unstable sulfur sources.In this work,we introduce a photocatalyzed hydrogen transfer strategy that enables a three-component synthesis of thioesters using abundant primary alcohols,easily available alkenes and elemental sulfur under mild conditions.This protocol demonstrates broad applicability and high chemo-and regioselectivity for both primary alcohols and alkenes,highlighting the advantage and potential of photo-mediated hydrogen transfer in facilitating multicomponent reactions using primary alcohol and elemental sulfur feedstocks.
基金supported by the Hainan Province Science and Technology Special Fund(ZDYF2023GXJS165)the National Natural Science Foundation of China(52164028,22109035,52274297)+2 种基金the Foundation of State Key Laboratory of Marine Resource Utilization in South China Sea(Hainan University,MRUKF2021029)the Start-up Research Foundation of Hainan University(KYQD(ZR)-20008,20084,21170)the Specific Research Fund of the Innovation Platform for Academicians of Hainan Province。
文摘The development of catalysts with highly efficient oxygen evolution performance and low-Ir loading is key to scaling up the application of proton exchange membrane(PEM)water electrolysis technology.Here,an Ir-skin catalyst(Ir@KM)is realized on a potassium-manganese oxide(K_(0.25)MnO_(x)(KM))using an ion-exchange method.The Ir-skin over the prepared Ir@KM has a low Ir-Ir atomic distance,endowing an energetically favorable oxide path mechanism to allow a low theoretical overpotential of 0.13 V.Ir@KM offers a low overpotential of~280 mV at a current density of 10 mA cm^(-2)and provides a high mass activity of up to 18,500 A at a cell voltage of 1.8 V in PEM,which is 17.6 times higher than that of IrO_(2),demonstrating a significant advantage in reducing the cost of the membrane electrode.The presented Ir-skin concept represents a promising strategy to fabricate low-Ir catalyst with high activity and durability for practical applications of PEM.
基金Project supported by the National Key R&D Program of China(Grant Nos.2021YFA1400500 and 2025YFF1502400)the National Natural Science Foundation of China(Grant Nos.92361302,12250001,12535001,and U22A20260)+3 种基金the China Postdoctoral Science Foundation(Grant Nos.BX20230021,2023T160011,and 2024M760068)support from the National Program for Support of Top-notch Young professionalssupport from Beijing Outstanding Young Scientist Program(Grant No.JWZQ20240101002)the New Cornerstone Science Foundation through the New Cornerstone Investigator Program and the XPLORER PRIZE。
文摘Ice premelting,the formation of a quasi-liquid layer on ice surfaces below the bulk melting point,plays a crucial role in various processes,ranging from glacier dynamics to ice friction and surface chemistry.Despite intensive research,the microscopic structure of the premelting layer and underlying molecular mechanisms remain poorly understood.In this work,we studied the temperature-and pressure-dependent structural disordering of crystalline Ih(0001)surface near the onset of premelting on the atomic scale by qPlus-based cryogenic atomic force microscopy.The linear correlation between the density of planar local structure(PLS)and the fraction of disordered surface region showed that the PLS mediated early-stage premelting by serving as a metastable seeding state.Notably,the associated surface disordering is cooperative,extending over an area of roughly~2 nm^(2) around a PLS.We further found a striking structural similarity between the kinetic-trapped regime below the surface crystallization temperature(T_(c))and the premelting-dominated regime above T_(c).As the deposition pressure increased,the characteristic temperature dependence was preserved,with only T_(c) shifting to higher values due to kinetic effects.Finally,we proposed a surface phase diagram for ice Ih(0001)based on our experimental observations.
基金supported by the National Natural Science Foundation of China(Nos.22406081,22276086,22306086)the Natural Science Foundation of Jiangxi Province(No.20232BAB213029),all of which are greatly acknowledged by the authors.
文摘Fenton-like technology based on peroxymonosulfate activation has shown great potential in refractory organics degradation.In this work,single Fe atom catalysts were synthesized through facile ball milling and exhibited very high performance in peroxymonosulfate activation.The Fe single-atom filled an N vacancy on the triazine ring edge of C_(3)N_(4),as confirmed through X-ray absorption fine structure,density functional calculation and elec-tron paramagnetic resonance.The SAFe_(0.4)–C_(3)N_(4)/PMS system could completely remove phenol(20 mg/L)within 10 min and its first-order kinetic constant was 12.3 times that of the Fe_(3)O_(4)/PMS system.Under different ini-tial pH levels and in various anionic environments,SAFe_(0.4)–C_(3)N_(4) still demonstrated excellent catalytic activity,achieving a removal rate of over 90%for phenol within 12 min.In addition,SAFe_(0.4)–C_(3)N_(4) exhibited outstanding selectivity in reaction systems with different pollutants,showing excellent degradation effects on electron-rich pollutants only.Hydroxyl radicals(•OH),singlet oxygen(1O_(2))and high-valent iron oxide(Fe(Ⅳ)=O)were de-tected in the SAFe_(0.4)–C_(3)N_(4)/PMS system through free radical capture experiments.Further experiments on the quenching of active species and a methyl phenyl sulfoxide probe confirmed that 1O_(2) and Fe(Ⅳ)=O played dom-inant roles.Additionally,the change in the current response after adding PMS and phenol in succession proved that a direct electron transfer path between organic matter and the catalyst surface was unlikely to exist in the SAFe_(0.4)–C_(3)N_(4)/PMS/Phenol degradation system.This study provides a new demonstration of the catalytic mech-anism of single-atom catalysts.
基金supported by the National Natural Science Foundation of China(52402166)the Science and Technology Development Fund+2 种基金Macao SAR(0065/2023/AFJ,0116/2022/A3)the Australian Research Council(DE220100154)the Natural Science Foundation of Guangdong Province(2025A1515011120)。
文摘The dissolvable polysulfides and sluggish Li_2S conversion kinetics are acknowledged as two significant challenges in the application lithium-sulfur(Li-S)batteries.Herein,we introduce a dual-doping strategy to modulate the electronic structure of MoS_(2),thereby obtaining a multifunctional catalyst that serves as an efficient sulfur host.The W/V dual single-atomdoped MoS_(2)grown on carbon nanofibers(CMWVS)demonstrates a strong adsorption ability for lithium polysulfides,suppressing the shuttle effects.Additionally,the doping process also results in the phase transition from 2H-MoS_(2)to 1T-MoS_(2)and generates sufficient edge sulfur atoms,promoting the charge/electron transfer and enriching the reaction sites.All these merits contribute to the superior conversion reaction kinetics,leading to the outstanding Li-S battery performance.When fabricated as cathodes by compositing with sulfur,the CMWVS/S cathode delivers a high capacity of 1481.7 mAh g^(-1)at 0.1 C(1 C=1672 mAh g^(-1))and maintains 816.3 m Ah g^(-1)after 1000 cycles at 1.0 C,indicating outstanding cycling stability.Even under a high sulfur loading of 7.9 mg cm^(-2)and lean electrolyte conditions(E/S ratio of 9.0μL mg^(-1)),the cathode achieves a high areal capacity of 8.2 m Ah cm^(-2),showing great promise for practical Li-S battery applications.This work broadens the scope of doping strategies in transition-metal dichalcogenides by tailoring their electronic structures,providing insightful direction for the rational development of high-efficiency electrocatalysts for advanced Li-S battery applications.
基金supported by the National Natural Science Foundation of China (22472031,U24A20567,22032002)the 111 Project。
文摘A visible-light-induced synergistic hydrogen atom transfer(HAT)and proton transfer(PT)catalysis was developed for the defluorinative carboxylation of α-CF_(2)R-substituted alkenes.This system affords a variety of γ,γ-difluoro-and γ-monofluoro-vinylacetic acids without stepwise acidification,exhibiting good functional group tolerance,broad scope,and facile scalability.Mechanism studies support that thiol plays the role of the hydrogen relay,which s a hydrogen atom through HAT and then outputs a proton via PT.This strategy also takes full advantage of formate for photocatalytic carboxylation reaction in a step-and atomeconomical way.
