Electrochemical reduction of acetonitrile to ethylamine with a high selectivity is a novel approach to manufacture valuable primary amines which are important raw material in organic chemical industry. However, the po...Electrochemical reduction of acetonitrile to ethylamine with a high selectivity is a novel approach to manufacture valuable primary amines which are important raw material in organic chemical industry. However, the poor ethylamine Faradic efficiency(FE_(ethylamine)) and catalyst stability at the high current density prohibit this method from being practically used. Herein, CuNi alloy ultrafine-nano-particles based on the d-orbital coupling modulation were synthesized through the electrodeposition and their catalytic performance towards acetonitrile reduction reaction(ACNRR) has been systematically studied. The highest FE_(ethylamine)(97%) is achieved with the current density of-114 mA cm^(-2). For practical application, the current density can reach-602.8 mA cm^(-2) with 82.8% FE_(ethylamine)maintained. With the appearance of other organics which co-exist with acetonitrile in the SOHIO process, CuNi can also hydrogenate acetonitrile in it with more than 80% FE_(ethylamine). Our in-situ spectroscopy analysis and DFT calculations towards the acetonitrile hydrogenation behavior reveal that the evenly dispersed Ni in Cu modulates the dband so as to endow CuNi with the better acetonitrile adsorption, milder binding energy with the reaction intermediates, smaller barrier for *CH_3CH_2NH_2 desorption and higher ability for H_2O dissociation to provide *H.展开更多
The Tianshan Mountains of Central Asia,highly sensitive to climate change,has been comprehensively assessed for its ecosystem vulnerability across multiple aspects.However,studies on the region's main river system...The Tianshan Mountains of Central Asia,highly sensitive to climate change,has been comprehensively assessed for its ecosystem vulnerability across multiple aspects.However,studies on the region's main river systems and hydropower resources remain limited.Thus,examining the impact of climate change on the runoff and gross hydropower potential(GHP)of this region is essential for promoting sustainable development and effective management of water and hydropower resources.This study focused on the Kaidu River Basin that is situated above the Dashankou Hydropower Station on the southern slope of the Tianshan Mountains,China.By utilizing an ensemble of bias-corrected global climate models(GCMs)from Coupled Model Intercomparison Project Phase 6(CMIP6)and the Variable Infiltration Capacity(VIC)model coupled with a glacier module(VIC-Glacier),we examined the variations in future runoff and GHP during 2017-2070 under four shared socio-economic pathway(SSP)scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5)compared to the baseline period(1985-2016).The findings indicated that precipitation and temperature in the Kaidu River Basin exhibit a general upward trend under the four SSP scenarios,with the fastest rate of increase in precipitation under the SSP2-4.5 scenario and the most significant changes in mean,maximum,and minimum temperatures under the SSP5-8.5 scenario,compared to the baseline period(1980-2016).Future runoff in the basin is projected to decrease,with rates of decline under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios being 3.09,3.42,7.04,and 7.20 m^(3)/s per decade,respectively.The trends in GHP are consistent with runoff,with rates of decline in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios at 507.74,563.33,1158.44,and 1184.52 MW/10a,respectively.Compared to the baseline period(1985-2016),the rates of change in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios are-20.66%,-20.93%,-18.91%,and-17.49%,respectively.The Kaidu River Basin will face significant challenges in water and hydropower resources in the future,underscoring the need to adjust water resource management and hydropower planning within the basin.展开更多
Stress is a major risk factor for the development of mental illness,such as major depression disorder (MDD)[1].Despite decades of progress,including findings that stressinduced depression corresponds with numerous mor...Stress is a major risk factor for the development of mental illness,such as major depression disorder (MDD)[1].Despite decades of progress,including findings that stressinduced depression corresponds with numerous morphological and functional neuronal changes within brain structures associated with cognition and mood,such as the medial prefrontal cortex (mPFC)[1-3],a thorough understanding of how stress induces the core symptoms of depression,such as hopelessness,is still lacking.In an exciting new paper in mice,Yin et al.show that astrocyteneuronal metabolic coupling in the mPFC is critically involved in the stress-induced passive coping response in mice [4].展开更多
An improved coupling of numerical and physical models for simulating 2D wave propagation is developed in this paper. In the proposed model, an unstructured finite element model （FEM） based Boussinesq equations is ap...An improved coupling of numerical and physical models for simulating 2D wave propagation is developed in this paper. In the proposed model, an unstructured finite element model （FEM） based Boussinesq equations is applied for the numerical wave simulation, and a 2D piston-type wavemaker is used for the physical wave generation. An innovative scheme combining fourth-order Lagrange interpolation and Runge-Kutta scheme is described for solving the coupling equation. A Transfer function modulation method is presented to minimize the errors induced from the hydrodynamic invalidity of the coupling model and/or the mechanical capability of the wavemaker in area where nonlinearities or dispersion predominate. The overall performance and applicability of the coupling model has been experimentally validated by accounting for both regular and irregular waves and varying bathymetry. Experimental results show that the proposed numerical scheme and transfer function modulation method are efficient for the data transfer from the numerical model to the physical model up to a deterministic level.展开更多
The emission spectrum of a two-level atom interacting with a single mode radiation field in the case of periodic oscillation coupling coefficient is investigated.A general expression for the emission spectrum is deriv...The emission spectrum of a two-level atom interacting with a single mode radiation field in the case of periodic oscillation coupling coefficient is investigated.A general expression for the emission spectrum is derived.The numerical results for the initial field in pure number stare are calculated.It is found that the effect of the coupling coefficient modulation on the spectral structure is very obvious in the case of a low modulation frequency and larger amplitude when the initial field is vacuum,which is potentially useful for exploring a modulated light source.展开更多
The equivalent refractive index(ERI)method is employed to analyze the function of the strip waveguide directional coupling modulator(SWM).Through deducing the diagnostic equation of the Exmn mode of the four-layer med...The equivalent refractive index(ERI)method is employed to analyze the function of the strip waveguide directional coupling modulator(SWM).Through deducing the diagnostic equation of the Exmn mode of the four-layer media film waveguide equivalent to the SWM,the transmission constant of the symmetrical mode of the positive phase and negative one and the coupling length of powerful transference are obtained.The veracity of ERI is validated with the example of Ex11 basal mode under conditions of comparing the three results of ERI,EIM and Marcatili.展开更多
The coupling efficiency of the beam combination and the fiber-coupled module is limited due to the large vertical divergent angle of conventional semiconductor laser diodes. We present a high coupling efficiency modul...The coupling efficiency of the beam combination and the fiber-coupled module is limited due to the large vertical divergent angle of conventional semiconductor laser diodes. We present a high coupling efficiency module using photonic-band-crystal （PBC） laser diodes with narrow vertical divergent angles. Three PBC single-emitter laser diodes are combined into a fiber with core diameter of 105μm and numerical aperture of 0.22. A high coupling efficiency of 94.4% is achieved and the brightness is calculated to be 1.T MW/（cm2.sr） with the injection current of 8A.展开更多
We construct various novel exact solutions of two coupled dynamical nonlinear Schrōdinger equations. Based on the similarity transformation, we reduce the coupled nonlinear Schrōdinger equations with time-and space-...We construct various novel exact solutions of two coupled dynamical nonlinear Schrōdinger equations. Based on the similarity transformation, we reduce the coupled nonlinear Schrōdinger equations with time-and space-dependent potentials, nonlinearities, and gain or loss to the coupled dynamical nonlinear Schrrdinger equations. Some special types of non-travelling wave solutions, such as periodic, resonant, and quasiperiodically oscillating solitons, are used to exhibit the wave propagations by choosing some arbitrary functions. Our results show that the number of the localized wave of one component is always twice that of the other one. In addition, the stability analysis of the solutions is discussed numerically.展开更多
Atmospheric pressure plasma jet(APPJ)arrays have shown a potential in a wide range of applications ranging from material processing to biomedicine.In these applications,targets with complex three-dimensional structure...Atmospheric pressure plasma jet(APPJ)arrays have shown a potential in a wide range of applications ranging from material processing to biomedicine.In these applications,targets with complex three-dimensional structures often easily affect plasma uniformity.However,the uniformity is usually crucially important in application areas such as biomedicine,etc.In this work,the flow and electric field collaborative modulations are used to improve the uniformity of the plasma downstream.Taking a two-dimensional sloped metallic substrate with a 10°inclined angle as an example,the influences of both flow and electric field on the electron and typical active species distributions downstream are studied based on a multi-field coupling model.The electric and flow fields modulations are first separately applied to test the influence.Results show that the electric field modulation has an obvious improvement on the uniformity of plasma while the flow field modulation effect is limited.Based on such outputs,a collaborative modulation of both fields is then applied,and shows a much better effect on the uniformity.To make further advances,a basic strategy of uniformity improvement is thus acquired.To achieve the goal,an artificial neural network method with reasonable accuracy is then used to predict the correlation between plasma processing parameters and downstream uniformity properties for further improvement of the plasma uniformity.An optional scheme taking advantage of the flexibility of APPJ arrays is then developed for practical demands.展开更多
Natrium superionic conductor(NASICON)-type phosphates have aroused a great interest as cathode materials for sodium-ion batteries(SIBs)by virtue of their stable 3-dimensional frameworks,flexible molecular formula tuna...Natrium superionic conductor(NASICON)-type phosphates have aroused a great interest as cathode materials for sodium-ion batteries(SIBs)by virtue of their stable 3-dimensional frameworks,flexible molecular formula tunability,and superior ionic conductivity.Nevertheless,the intrinsic low electronic conductivity and relatively low theoretical specific capacity place obstacles in their way toward achieving higher electrochemical performance.In addition,only 2-electron reactions in most NASICON cathodes and poor reversibility of high-voltage redox couples severely limit their energy density.To address the above tough issues,an in-depth understanding of transition metal selection,elements ratio optimization,and Na-storage mechanism is of paramount importance.Here,this mini review summarizes the latest progresses on the NASICON-type phosphate cathodes for SIBs from the perspective of redox couple modulation.NASICON cathodes featuring high operating voltage and multielectron reactions are discussed in detail.Finally,the remaining challenges and personal outlooks based on redox couple regulation are put forward,shedding light on the designing rules for high-energy and long-durability NASICON-type phosphate cathodes for SIBs in the future.展开更多
During the operation of pressurized water reactors,erosion products can be deposited on the surfaces of the fuel rods,and these deposits lead to enrichment of boric acid,which influences the power distribution along t...During the operation of pressurized water reactors,erosion products can be deposited on the surfaces of the fuel rods,and these deposits lead to enrichment of boric acid,which influences the power distribution along the axial direction and results in axial offset anomaly(AOA)/Chalk River unidentified deposit(CRUD)-induced power shift(CIPS).In this paper,a fully integrated CIPS risk prediction framework is proposed.The framework comprises three coupled modules:CRUD deposition prediction,boron concentration calculation,and neutron flux calculation.These modules are dynamically coupled through CRUD deposition distribution and boric acid concentration data,ensuring comprehensive and up-to-date predictions.To demonstrate the framework’s capabilities,we provide a case study involving a 500-day reactor operation.Our results indicate a maximum CRUD thickness approaching 40μm,primarily located in the upper half of the fuel rod.This deposition corresponds to a maximum boric acid concentration ratio exceeding 300,which significantly reduces heat flux in the affected region and precipitates a severe AOA/CIPS incident.展开更多
Based on the high-speed development of the fiber laser in recent years, the development of researching 915 nm semiconductor laser as main pumping sources of the fiber laser is at a high speed. Because the beam quality...Based on the high-speed development of the fiber laser in recent years, the development of researching 915 nm semiconductor laser as main pumping sources of the fiber laser is at a high speed. Because the beam quality of the laser diode is very poor, the 915 nm laser diode is generally based on optical fiber coupling module to output the laser. Using the beam-shaping and fiber-coupling technology to improve the quality of output beam light, we present a kind of high-power and high-brightness semiconductor laser module, which can output 13.22 W through the optical fiber. Based on 915 nm GaAs semiconductor laser diode which has output power of 13.91 W, we describe a thoroughly detailed procedure for reshaping the beam output from the semiconductor laser diode and coupling the beam into the optical fiber of which the core diameter is 105 μm and the numerical aperture is 0.18. We get 13.22 W from the output fiber of the module at 14.5 A, the coupling efficiency of the whole module is 95.03% and the brightness is 1.5 MW/cm2-str. The output power of the single chip semiconductor laser module achieves the advanced level in the domestic use.展开更多
A Kerr-lens, mode-locked YVO4∕Nd:YVO4laser coupled with an acousto-optic modulator（AOM） Q-switching near1064 nm was employed to pump an intracavity KTi OPO4（KTP） optical parametric oscillator. A subnanosecond sig...A Kerr-lens, mode-locked YVO4∕Nd:YVO4laser coupled with an acousto-optic modulator（AOM） Q-switching near1064 nm was employed to pump an intracavity KTi OPO4（KTP） optical parametric oscillator. A subnanosecond signal wave near 1572 nm with low repetition rate was realized. At an AOM repetition rate of 8 kHz, the maximum output power was 165 mW. The highest average pulse energy, the shortest duration, and the highest peak power of a mode-locking signal pulse were estimated to be ～10.3 μJ, ～120 ps, and ～82 kW, respectively.展开更多
基金the National Natural Science Foundation of China (12025503, 12105208)the Fundamental Research Funds for the Central Universities of China (2042022kf1181)China Postdoctoral Science Foundation (2020M682469)。
文摘Electrochemical reduction of acetonitrile to ethylamine with a high selectivity is a novel approach to manufacture valuable primary amines which are important raw material in organic chemical industry. However, the poor ethylamine Faradic efficiency(FE_(ethylamine)) and catalyst stability at the high current density prohibit this method from being practically used. Herein, CuNi alloy ultrafine-nano-particles based on the d-orbital coupling modulation were synthesized through the electrodeposition and their catalytic performance towards acetonitrile reduction reaction(ACNRR) has been systematically studied. The highest FE_(ethylamine)(97%) is achieved with the current density of-114 mA cm^(-2). For practical application, the current density can reach-602.8 mA cm^(-2) with 82.8% FE_(ethylamine)maintained. With the appearance of other organics which co-exist with acetonitrile in the SOHIO process, CuNi can also hydrogenate acetonitrile in it with more than 80% FE_(ethylamine). Our in-situ spectroscopy analysis and DFT calculations towards the acetonitrile hydrogenation behavior reveal that the evenly dispersed Ni in Cu modulates the dband so as to endow CuNi with the better acetonitrile adsorption, milder binding energy with the reaction intermediates, smaller barrier for *CH_3CH_2NH_2 desorption and higher ability for H_2O dissociation to provide *H.
基金funded by the National Natural Science Foundation of China(42067062).
文摘The Tianshan Mountains of Central Asia,highly sensitive to climate change,has been comprehensively assessed for its ecosystem vulnerability across multiple aspects.However,studies on the region's main river systems and hydropower resources remain limited.Thus,examining the impact of climate change on the runoff and gross hydropower potential(GHP)of this region is essential for promoting sustainable development and effective management of water and hydropower resources.This study focused on the Kaidu River Basin that is situated above the Dashankou Hydropower Station on the southern slope of the Tianshan Mountains,China.By utilizing an ensemble of bias-corrected global climate models(GCMs)from Coupled Model Intercomparison Project Phase 6(CMIP6)and the Variable Infiltration Capacity(VIC)model coupled with a glacier module(VIC-Glacier),we examined the variations in future runoff and GHP during 2017-2070 under four shared socio-economic pathway(SSP)scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5)compared to the baseline period(1985-2016).The findings indicated that precipitation and temperature in the Kaidu River Basin exhibit a general upward trend under the four SSP scenarios,with the fastest rate of increase in precipitation under the SSP2-4.5 scenario and the most significant changes in mean,maximum,and minimum temperatures under the SSP5-8.5 scenario,compared to the baseline period(1980-2016).Future runoff in the basin is projected to decrease,with rates of decline under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios being 3.09,3.42,7.04,and 7.20 m^(3)/s per decade,respectively.The trends in GHP are consistent with runoff,with rates of decline in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios at 507.74,563.33,1158.44,and 1184.52 MW/10a,respectively.Compared to the baseline period(1985-2016),the rates of change in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios are-20.66%,-20.93%,-18.91%,and-17.49%,respectively.The Kaidu River Basin will face significant challenges in water and hydropower resources in the future,underscoring the need to adjust water resource management and hydropower planning within the basin.
文摘Stress is a major risk factor for the development of mental illness,such as major depression disorder (MDD)[1].Despite decades of progress,including findings that stressinduced depression corresponds with numerous morphological and functional neuronal changes within brain structures associated with cognition and mood,such as the medial prefrontal cortex (mPFC)[1-3],a thorough understanding of how stress induces the core symptoms of depression,such as hopelessness,is still lacking.In an exciting new paper in mice,Yin et al.show that astrocyteneuronal metabolic coupling in the mPFC is critically involved in the stress-induced passive coping response in mice [4].
基金supported by the National Natural Science Foundation of China(Grant Nos.51079023 and 51221961)the National Basic Research Program of China(973 Program,Grant Nos.2013CB036101 and 2011CB013703)
文摘An improved coupling of numerical and physical models for simulating 2D wave propagation is developed in this paper. In the proposed model, an unstructured finite element model （FEM） based Boussinesq equations is applied for the numerical wave simulation, and a 2D piston-type wavemaker is used for the physical wave generation. An innovative scheme combining fourth-order Lagrange interpolation and Runge-Kutta scheme is described for solving the coupling equation. A Transfer function modulation method is presented to minimize the errors induced from the hydrodynamic invalidity of the coupling model and/or the mechanical capability of the wavemaker in area where nonlinearities or dispersion predominate. The overall performance and applicability of the coupling model has been experimentally validated by accounting for both regular and irregular waves and varying bathymetry. Experimental results show that the proposed numerical scheme and transfer function modulation method are efficient for the data transfer from the numerical model to the physical model up to a deterministic level.
基金Supported by the Shandong Province Natural Science Foundation under Grant No.ZR2009AM019
文摘The emission spectrum of a two-level atom interacting with a single mode radiation field in the case of periodic oscillation coupling coefficient is investigated.A general expression for the emission spectrum is derived.The numerical results for the initial field in pure number stare are calculated.It is found that the effect of the coupling coefficient modulation on the spectral structure is very obvious in the case of a low modulation frequency and larger amplitude when the initial field is vacuum,which is potentially useful for exploring a modulated light source.
文摘The equivalent refractive index(ERI)method is employed to analyze the function of the strip waveguide directional coupling modulator(SWM).Through deducing the diagnostic equation of the Exmn mode of the four-layer media film waveguide equivalent to the SWM,the transmission constant of the symmetrical mode of the positive phase and negative one and the coupling length of powerful transference are obtained.The veracity of ERI is validated with the example of Ex11 basal mode under conditions of comparing the three results of ERI,EIM and Marcatili.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61535013,61321063 and 61404133the National Key Research and Development Program of China under Grant Nos 2016YFB0402203,2016YFB0401804 and2016YFA0301102the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2014096
文摘The coupling efficiency of the beam combination and the fiber-coupled module is limited due to the large vertical divergent angle of conventional semiconductor laser diodes. We present a high coupling efficiency module using photonic-band-crystal （PBC） laser diodes with narrow vertical divergent angles. Three PBC single-emitter laser diodes are combined into a fiber with core diameter of 105μm and numerical aperture of 0.22. A high coupling efficiency of 94.4% is achieved and the brightness is calculated to be 1.T MW/（cm2.sr） with the injection current of 8A.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11275072,11075055,and 11271211)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120076110024)+3 种基金the Innovative Research Team Program of the National Natural Science Foundation of China(Grant No.61021004)the Shanghai Leading Academic Discipline Project,China(Grant No.B412)the National High Technology Research and Development Program of China(Grant No.2011AA010101)the Shanghai Knowledge Service Platform for Trustworthy Internet of Things,China(Grant No.ZF1213)
文摘We construct various novel exact solutions of two coupled dynamical nonlinear Schrōdinger equations. Based on the similarity transformation, we reduce the coupled nonlinear Schrōdinger equations with time-and space-dependent potentials, nonlinearities, and gain or loss to the coupled dynamical nonlinear Schrrdinger equations. Some special types of non-travelling wave solutions, such as periodic, resonant, and quasiperiodically oscillating solitons, are used to exhibit the wave propagations by choosing some arbitrary functions. Our results show that the number of the localized wave of one component is always twice that of the other one. In addition, the stability analysis of the solutions is discussed numerically.
基金National Natural Science Foundation of China(Nos.51577044 and 52022026).
文摘Atmospheric pressure plasma jet(APPJ)arrays have shown a potential in a wide range of applications ranging from material processing to biomedicine.In these applications,targets with complex three-dimensional structures often easily affect plasma uniformity.However,the uniformity is usually crucially important in application areas such as biomedicine,etc.In this work,the flow and electric field collaborative modulations are used to improve the uniformity of the plasma downstream.Taking a two-dimensional sloped metallic substrate with a 10°inclined angle as an example,the influences of both flow and electric field on the electron and typical active species distributions downstream are studied based on a multi-field coupling model.The electric and flow fields modulations are first separately applied to test the influence.Results show that the electric field modulation has an obvious improvement on the uniformity of plasma while the flow field modulation effect is limited.Based on such outputs,a collaborative modulation of both fields is then applied,and shows a much better effect on the uniformity.To make further advances,a basic strategy of uniformity improvement is thus acquired.To achieve the goal,an artificial neural network method with reasonable accuracy is then used to predict the correlation between plasma processing parameters and downstream uniformity properties for further improvement of the plasma uniformity.An optional scheme taking advantage of the flexibility of APPJ arrays is then developed for practical demands.
基金financially supported by the National Natural Science Foundation of China(22075016 and 52372171)National Program for Support of Top-notch Young Professionals,Interdisciplinary Research Project for Young Teachers of USTB(FRF-IDRY-21-011)+2 种基金State Key Laboratory for Advanced Metals and Materials(2022Z-17)Fundamental Research Funds for the Central Universities(QNXM20220060)“Xiaomi Young Scholar”Funding Project,and 111 Project(B170003).
文摘Natrium superionic conductor(NASICON)-type phosphates have aroused a great interest as cathode materials for sodium-ion batteries(SIBs)by virtue of their stable 3-dimensional frameworks,flexible molecular formula tunability,and superior ionic conductivity.Nevertheless,the intrinsic low electronic conductivity and relatively low theoretical specific capacity place obstacles in their way toward achieving higher electrochemical performance.In addition,only 2-electron reactions in most NASICON cathodes and poor reversibility of high-voltage redox couples severely limit their energy density.To address the above tough issues,an in-depth understanding of transition metal selection,elements ratio optimization,and Na-storage mechanism is of paramount importance.Here,this mini review summarizes the latest progresses on the NASICON-type phosphate cathodes for SIBs from the perspective of redox couple modulation.NASICON cathodes featuring high operating voltage and multielectron reactions are discussed in detail.Finally,the remaining challenges and personal outlooks based on redox couple regulation are put forward,shedding light on the designing rules for high-energy and long-durability NASICON-type phosphate cathodes for SIBs in the future.
基金the financial support of the Zhejiang Provincial Natural Science Foundation of China under Grant No.LZ25A020005.
文摘During the operation of pressurized water reactors,erosion products can be deposited on the surfaces of the fuel rods,and these deposits lead to enrichment of boric acid,which influences the power distribution along the axial direction and results in axial offset anomaly(AOA)/Chalk River unidentified deposit(CRUD)-induced power shift(CIPS).In this paper,a fully integrated CIPS risk prediction framework is proposed.The framework comprises three coupled modules:CRUD deposition prediction,boron concentration calculation,and neutron flux calculation.These modules are dynamically coupled through CRUD deposition distribution and boric acid concentration data,ensuring comprehensive and up-to-date predictions.To demonstrate the framework’s capabilities,we provide a case study involving a 500-day reactor operation.Our results indicate a maximum CRUD thickness approaching 40μm,primarily located in the upper half of the fuel rod.This deposition corresponds to a maximum boric acid concentration ratio exceeding 300,which significantly reduces heat flux in the affected region and precipitates a severe AOA/CIPS incident.
文摘Based on the high-speed development of the fiber laser in recent years, the development of researching 915 nm semiconductor laser as main pumping sources of the fiber laser is at a high speed. Because the beam quality of the laser diode is very poor, the 915 nm laser diode is generally based on optical fiber coupling module to output the laser. Using the beam-shaping and fiber-coupling technology to improve the quality of output beam light, we present a kind of high-power and high-brightness semiconductor laser module, which can output 13.22 W through the optical fiber. Based on 915 nm GaAs semiconductor laser diode which has output power of 13.91 W, we describe a thoroughly detailed procedure for reshaping the beam output from the semiconductor laser diode and coupling the beam into the optical fiber of which the core diameter is 105 μm and the numerical aperture is 0.18. We get 13.22 W from the output fiber of the module at 14.5 A, the coupling efficiency of the whole module is 95.03% and the brightness is 1.5 MW/cm2-str. The output power of the single chip semiconductor laser module achieves the advanced level in the domestic use.
基金supported by the National Natural Science Foundation of China (61378022)the National Natural Science Foundation of China for Youths (61205145)+2 种基金the Fundamental Research Funds of Shandong University (2014JC032)the China Postdoctoral Science Foundation (2013M541901)Independent Innovation Foundation of Shandong University, IIFSDU (2013HW013 and 2014TB011)
文摘A Kerr-lens, mode-locked YVO4∕Nd:YVO4laser coupled with an acousto-optic modulator（AOM） Q-switching near1064 nm was employed to pump an intracavity KTi OPO4（KTP） optical parametric oscillator. A subnanosecond signal wave near 1572 nm with low repetition rate was realized. At an AOM repetition rate of 8 kHz, the maximum output power was 165 mW. The highest average pulse energy, the shortest duration, and the highest peak power of a mode-locking signal pulse were estimated to be ～10.3 μJ, ～120 ps, and ～82 kW, respectively.
