We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse ...We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse with a plasma and one or multiple photon beams supplied by intense lasers.Owing to nonlinear effects,two-or multiphoton absorption dominates over the conventional multistep one-photon process for an optimized γ flash.Moreover,this nonlinear effect can be greatly enhanced with the help of externally supplied low-energy photons coming from another laser.These low-energy photons act such that the effective cross-section experienced by the γ photons becomes tunable,growing with the intensity I_(0) of the beam.Assuming I_(0)~10^(18) W·cm^(-2) for the photon beam,an effective cross-section as large as 10^(-21)-10^(-28) cm^(2) for the γ photons can be achieved.Thus,with state-of-the-art 10 PW laser facilities,the yields from two-photon absorption can reach 10^(6)-10^(9) isomers per shot for selected states that are separated from their ground state by E2 transitions.Similar yields for transitions with higher multipolarities can be accommodated by multiphoton absorption with additional photons provided.展开更多
This research investigates the design and optimization of a photovoltaic(PV)water pumping system to address seasonal water demands across five locations with varying elevation heads.The systemdraws water froma deep we...This research investigates the design and optimization of a photovoltaic(PV)water pumping system to address seasonal water demands across five locations with varying elevation heads.The systemdraws water froma deep well with a static water level of 30mand a dynamic level of 50m,serving agricultural and livestock needs.The objective of this study is to accurately size a PV system that balances energy generation and demand while minimizing grid dependency.Meanwhile,the study presents a comprehensivemethodology to calculate flowrates,pumping power,daily energy consumption,and system capacity.Therefore,the PV system rating,energy output,and economic performance were evaluated using metrics such as discounted payback period(DPP),net present value(NPV),and sensitivity analysis.The results show that a 2.74 kWp PV system is optimal,producing 4767 kWh/year to meet the system’s annual energy demand of 4686 kWh.In summer,energy demand peaks at 1532.7 kWh,while in winter,it drops to 692.1 kWh.Meanwhile,flow rates range from 11.71 m^(3)/h at 57 m head to 10.49 m^(3)/h at 70 m head,demonstrating the system’s adaptability to diverse hydraulic conditions.Economic analysis reveals that at a 5%interest rate and an electricity price of$0.15/kWh,the NPV is$6981.82 with a DPP of 3.76 years.However,a 30%increase in electricity prices improves the NPV to$10,005.18 and shortens the DPP to 2.76 years,whereas a 20%interest rate reduces the NPV to$1038.79 and extends the DPP to 6.08 years.Nevertheless,the annual PV energy generation exceeds total energy demand by 81 kWh,reducing grid dependency and lowering electricity costs.Additionally,the PV system avoids approximately 3956.6 kg of CO_(2) emissions annually,underscoring its environmental benefits over traditional pumping systems.As a result,this study highlights the economic and environmental viability of PV-powered water pumping systems,offering actionable insights for sustainable energy solutions in agriculture.展开更多
The study was carried out in the Tahoua region at the market gardening sites of the Taddis 1 and 2 valley. Small-scale pumping irrigation is one of the most interesting uses of solar energy. The objective of this stud...The study was carried out in the Tahoua region at the market gardening sites of the Taddis 1 and 2 valley. Small-scale pumping irrigation is one of the most interesting uses of solar energy. The objective of this study is to carry out a comparative analysis of two dewatering pumping systems (Solar Kit and GMP) for water mobilization on a certain number of criteria such as sustainable use, economic aspect and performance. To achieve this, the adapted methodology consisted first of all in the development of a data collection tool in the field. Then flow measurements, estimation of fuel consumption, pressure height, etc., were carried out. Thus, the data collection involved a sample of 120 irrigators who had to use the two (2) types of pumping systems. The collected data were analyzed and processed with appropriate software. The results of the study show that the two pumping systems studied have strengths and constraints. Thus, the solar pumping system has a significant investment cost, very low maintenance and a low operating cost. On the other hand, the system with a generator has a relatively low investment cost (25 to 30 times less than solar), but a relatively high operating, upkeep and maintenance cost. He adds that these assets and constraints must be taken into consideration when an investment is made. This study shows that 74% of producers use GMP compared to 26% who use the Solar Kit. But in practice, the Solar Kit is more reliable for producers from the point of view of planted area, environmental management and investment costs, supply of fuel and lubricant. These results indicate better performance of the solar pumping system compared to GMP at the study sites.展开更多
Background Acute Myocardial Infarction(AMI)is a critical and commonly encountered condition in the field of cardiovascular medicine.When AMI is complicated by cardiogenic shock(CS),the clinical scenario becomes signif...Background Acute Myocardial Infarction(AMI)is a critical and commonly encountered condition in the field of cardiovascular medicine.When AMI is complicated by cardiogenic shock(CS),the clinical scenario becomes significantly more complex and perilous,with a marked increase in patient mortality.Currently,traditional thera-peutic approaches such as intra-aortic balloon pumping(IABP)have demonstrated efficacy in improving myocardi-al perfusion and hemodynamics.However,the supportive capacity of IABP is limited in patients with severe heart failure.In recent years,extracorporeal membrane oxygenation(ECMO),as an advanced extracorporeal circulatory support technology,has been increasingly utilized in clinical practice,offering a novel therapeutic option for pa-tients with severe heart failure.This study aimed to investigate the clinical efficacy of combining IABP and ECMO in patients with AMI complicated by CS,evaluating its impact on myocardial injury,hemodynamic stability,and clinical outcomes.Methods This study retrospectively analyzed the clinical data of 52 patients with AMI compli-cated by CS admitted to our hospital between May 2023 and May 2024.Based on the treatment methods,the pa-tients were divided into an ECMO group(n=26)and a non-ECMO group(n=26).Post-treatment comparisons were made between the two groups regarding myocardial injury markers such as cardiac troponin I,lactate,and creatine kinase-MB,hemodynamic parameters such as mean arterial pressure,cardiac output,and central venous pressure,and the incidence of complications such as acute kidney injury,bleeding,infection.The primary endpoint of this study was the post-treatment mortality rate and the incidence of complications.Secondary endpoints included changes in myocardial injury markers[cardiac troponin I(cTnI),lactic acid(LAC),creatine kinase isoenzymes(CK-MB)]and improvements in hemodynamic parameters[mean arterial pressure(MAP),cardiac output(CO),central venous pressure(CVP)].The results of multivariate regression analyses were used to explore the incidence of EC-MO complications.Results After treatment,the levels of myocardial injury markers such as cTnI,LAC,and CK-MB in ECMO group were significantly lower than non-ECMO group(P<0.05);MAP and CO in ECMO group were significantly higher than non-ECMO group,while CVP was significantly lower(P<0.05);the mortality rate and the incidence of complications in ECMO group were lower than non-ECMO group(P<0.05).Further multivariate re-gression analysis showed that age,smoking,hyperlipidaemia and diabetes could affect the incidence of ECMO complications(P<0.05).Conclusions The combined use of IABP and ECMO exhibits substantial therapeutic benefits,including the mitigation of myocardial injury,enhancement of hemodynamic stability,and improvement in clinical prognosis among patients with AMI complicated by CS.Clinicians applying ECMO therapy should pay particular attention to older patients or those with concomitant diabetes mellitus or hyperlipidemia,as they might re-quire more intensive monitoring and prophylactic measures to mitigate the occurrence of complications.展开更多
Coupled-waveguide devices are essential in photonic integrated circuits for coupling,polarization handling,and mode manipulation.However,the performance of these devices usually suffers from high wavelength and struct...Coupled-waveguide devices are essential in photonic integrated circuits for coupling,polarization handling,and mode manipulation.However,the performance of these devices usually suffers from high wavelength and structure sensitivity,which makes it challenging to realize broadband and reliable on-chip optical functions.Recently,topological pumping of edge states has emerged as a promising solution for implementing robust optical couplings.In this paper,we propose and experimentally demonstrate broadband on-chip mode manipulation with very large fabrication tolerance based on the Rice–Mele modeled silicon waveguide arrays.The Thouless pumping mechanism is employed in the design to implement broadband and robust mode conversion and multiplexing.The experimental results prove that various mode-order conversions with low insertion losses and intermodal crosstalk can be achieved over a broad bandwidth of 80 nm ranging from 1500 to 1580 nm.Thanks to such a topological design,the device has a remarkable fabrication tolerance of±70 nm for the structural deviations in waveguide width and gap distance,which is,to the best of our knowledge,the highest among the coupled-waveguide mode-handling devices reported so far.As a proof-of-concept experiment,we cascade the topological mode-order converters to form a four-channel mode-division multiplexer and demonstrate the transmission of a 200-Gb/s 16-quadrature amplitude modulation signal for each mode channel,with the bit error rates below the 7%forward error correction threshold of 3.8×10^(-3).We reveal the possibility of developing new classes of broadband and fabrication-tolerant coupled-waveguide devices with topological photonic approaches,which may find applications in many fields,including optical interconnects,quantum communications,and optical computing.展开更多
In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,th...In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,the average output power of the fundamental laser at 1064 nm reaches as high as 20.98 W at a repetition rate of 50 Hz with a maximum single pulse energy of 419.6 mJ,corresponding to a maximum optical conversion efficiency of 38.8%and a slope efficiency of 41%.展开更多
High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an eff...High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis method.However,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational effort.Additionally,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different moments.Thus,there is heterogeneity in field data,which can dramatically impair the diagnostic accuracy.To solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this paper.First,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC data.Subsequently,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data heterogeneity.Finally,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the 4S-TFSM.Experiments on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational cost.To the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS.展开更多
As an emerging technology to convert environmental high-entropy energy into electrical energy,triboelectric nanogenerator(TENG)has great demands for further enhancing the service lifetime and output performance in pra...As an emerging technology to convert environmental high-entropy energy into electrical energy,triboelectric nanogenerator(TENG)has great demands for further enhancing the service lifetime and output performance in practical applications.Here,an ultra-robust and high-performance rotational triboelectric nanogenerator(R-TENG)by bearing charge pumping is proposed.The R-TENG composes of a pumping TENG(P-TENG),an output TENG(O-TENG),a voltage-multiplying circuit(VMC),and a buffer capacitor.The P-TENG is designed with freestanding mode based on a rolling ball bearing,which can also act as the rotating mechanical energy harvester.The output low charge from the P-TENG is accumulated and pumped to the non-contact O-TENG,which can simultaneously realize ultralow mechanical wear and high output performance.The matched instantaneous power of R-TENG is increased by 32 times under 300 r/min.Furthermore,the transferring charge of R-TENG can remain 95%during 15 days(6.4×10^(6)cycles)continuous operation.This work presents a realizable method to further enhance the durability of TENG,which would facilitate the practical applications of high-performance TENG in harvesting distributed ambient micro mechanical energy.展开更多
The spin pumping effect in magnetic heterostructures and multilayers is a highly effective method for the generationand transmission of spin currents. In the increasingly prominent synthetic antiferromagnetic structur...The spin pumping effect in magnetic heterostructures and multilayers is a highly effective method for the generationand transmission of spin currents. In the increasingly prominent synthetic antiferromagnetic structures, the two ferromagneticlayers demonstrate in-phase and out-of-phase states, corresponding to acoustic and optical precession modes. Withinthis context, our study explores the spin pumping effect in Py/Ru/Py synthetic antiferromagnetic structures across differentmodes. The heightened magnetic damping resulting from the spin pumping effect in the in-phase state initially decreaseswith increasing Py thickness before stabilizing. Conversely, in the out-of-phase state, the amplified damping exceeds thatof the in-phase state, suggesting a greater spin relaxation within this configuration, which demonstrates sensitivity to alterationsin static exchange interactions. These findings contribute to advancing the application of synthetic antiferromagneticstructures in magnonic devices.展开更多
A novel high quality-factor(Q)micro-ring resonator(MRR)structure based on the Si_(3)N_(4) ridge-slot waveguide is proposed,and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb.We optim...A novel high quality-factor(Q)micro-ring resonator(MRR)structure based on the Si_(3)N_(4) ridge-slot waveguide is proposed,and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb.We optimized the structure of MRR by the finite element method and precise dispersion engineering,which finally obtained the suitable MRR geometry with negative dispersion characteristics at 1550 nm,having Q of 1.7×10^(7)and the absorption loss as low as 2.6×10^(-5) dB/cm.The simulation model of generating dual-comb is established as coupled Lugiato-Lefever equation(LLE),which takes the higher order dispersion,cross-phase modulation(XPM),multiphoton absorption,and external pumping into account.Solved by the split-step Fourier method(SSFM)and the fourth-order Runge-Kutta(RK4)method,the numerical results show that the generated dual-comb is periodically equally spaced distribution,but with slightly different intensities in the time domain.In the frequency domain,there are 64 comb teeth with intensities higher than-100 dBm with a bandwidth of 120 nm.Particularly,in the case of bicolor orthogonal polarization pumping,a smaller amount of detuning does not greatly affect the bandwidth of the dual-comb.展开更多
In the dry tropical zone where access to water is increasingly difficult for populations, solar pumping units are increasingly installed to provide water to population. In the local market, there are essentially two t...In the dry tropical zone where access to water is increasingly difficult for populations, solar pumping units are increasingly installed to provide water to population. In the local market, there are essentially two types of solar panels, namely monocrystalline and polycrystalline. However, the part of the local market is more dominated by the polycrystalline panel. In this work, comparative studies are carried out in order to characterize the two types of solar panels with regard to local constraints. Tests were carried out over the course of the sun to establish the performance of each type. The panels used have the same electrical characteristics and are connected to loads with same characteristics. Under the set operating conditions, the monocrystalline panel presents more performance than the polycrystalline panel. Although the local market is dominated by the polycrystalline panel, dust deposition tests on the surface of the panels show that the performance of the polycrystalline panel is more affected compared to the performance of the monocrystalline panel.展开更多
This article examines the determinants of the adoption of solar pumping systems (PV) by vegetable farmers in the Niayes area of Senegal. To measure the determinants, we used a sequential logit model to translate the a...This article examines the determinants of the adoption of solar pumping systems (PV) by vegetable farmers in the Niayes area of Senegal. To measure the determinants, we used a sequential logit model to translate the adoption process from becoming aware of solar pumping systems to testing them, i.e. using them at least once, and then continuing to use them over time. The results show that the main variables affecting awareness of the use of solar pumping systems (PV) are age, marital status, experience, access to credit, the farmer’s knowledge of climate change, the farmer’s origin in the Thiès region and length of time in the Niayes area. The first use of PVs is influenced by factors such as the size of the plot, the distance of the plot from the main road or from the market. Finally, the decision to adopt or continue use is influenced by gender, experience, household size and access to credit. Surprisingly, access to credit does not affect the first use of solar pumping systems, but plays a key role in their continued use.展开更多
Tonoplast-enriched vesicles were prepared from suspension-cultured Populus euphratica Oliv. cells by differential centrifugation and discontinuous sucrose density gradient centrifugation. The properties of the proton ...Tonoplast-enriched vesicles were prepared from suspension-cultured Populus euphratica Oliv. cells by differential centrifugation and discontinuous sucrose density gradient centrifugation. The properties of the proton pumping activity of H+-ATPases in tonoplast vesicles were studied by acridine orange fluorescent quenching measured at 22 degreesC. The proton pumping activity of ATPase was ATP-dependent with apparent Michaelis-Menten Constant (K-m) for ATP about 0.65 mmol/L. The optimal pH for H+-ATPases activity was 7.5. The proton pumping activity of H+-ATPase could be initiated by some divalent cations, Mg2+ being highly efficient, much more than Fe2+; and Ca2+, Cu2+ and Zn2+ were inefficient under the experimental condition. The proton translocation could be stimulated by halide anions, with potencies decreasing in the order Cl- > Br- > I- > F-. The proton pumping activity was greatly inhibited by N-ethylmaleimide (NEM), N, N'-dicyclohexylcarbodiimide (DCCD), NO3- and Bafilomycin A(1), but not by orthovanadate and azide. These results demonstrated that the H+-ATPase in the tonoplast of Populus euphratica belonged to vacuolar type ATPase. This work was the first time that tonoplast-enriched vesicles were isolated from Populus euphratica cells.展开更多
Using the Keldysh-Green function,we present a theoretical study on the electron transport properties of two coupled quantum dots under optical pumping. Plateaus in the I-V curve and resonant peaks in the transmission ...Using the Keldysh-Green function,we present a theoretical study on the electron transport properties of two coupled quantum dots under optical pumping. Plateaus in the I-V curve and resonant peaks in the transmission coefficient occur and can be explained by the local electron density of states in the quantum dots. The effects of the optical pumping frequency and intensity on the transport properties of the system are also discussed. The electron dynamical localization phenomenon occurs when the optical pumping frequency is equal to the discrete hole energy level. This result can be used to realize optical control switches.展开更多
Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping unit...Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping units have many intrinsic disadvantages such as low efficiency, complex transmission devices, poor flexibility, tremendous volume and weight in long stroke, etc.Therefore, a novel direct driven linear electromagnetic pumping unit (EMPU) has been developed by combining oil extraction technology with linear motor technology. The thrust of EMPU matches the changing of suspension center load to improve the system efficiency and cut down the consumption of energy. Based on previous experience, a small-scale prototype was developed and a simulation was conducted with it. Both theoretical analyses and experimental study showed that the problems exiting in beam pumping units can be solved with EMPU system, and this is a new method which can be used to solve high energy waste in oil fields.展开更多
Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the supe...Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.展开更多
The aim of this study was to evaluate the effects of pumping height and repeated pumping on the generalized stress response and gross injuries in harvest sized Atlantic salmon. Fish pumped from a net pen at either hig...The aim of this study was to evaluate the effects of pumping height and repeated pumping on the generalized stress response and gross injuries in harvest sized Atlantic salmon. Fish pumped from a net pen at either high (5.2 m) or low (3.6 m) pumping heights showed an elevated, but not severe physiological stress response (pH, pCO<sub>2</sub>, lactate, potassium, haematocrit, and sodium) compared to fish netted (not pumped), while effects of different pumping heights were overall not demonstrated. Repeated pumping (either 3 or 6 times) also caused an increase in stress response (pH, pCO<sub>2</sub>, pO<sub>2</sub>, lactate, potassium and sodium) compared to control fish, and a positive dose-response relationship was found for lactate. No fish died as a result of pumping, nor were injuries observed that could exclusively be attributed to pumping. In conclusion, although elevated from the control groups, the stress response following increasing pumping height and repeated pumping as conducted in these experiments were not indicative of causing severe stress or injuries.展开更多
基金supported by the Extreme Light Infrastructure Nuclear Physics(ELI-NP)Phase Ⅱ,a project co-financed by the Romanian Government and the European Union through the European Regional Development Fund—the Competitiveness Operational Programme(1/07.07.2016,COP,ID 1334)the Romanian Ministry of Research and Innovation:PN23210105(Phase 2,the Program Nucleu),ELI-RO grants Proiectul ELI-RO/RDI_2024_AMAP,ELI-RO_RDI_2024_LaLuThe,ELIRO_RDI_2024_SPARC+4 种基金ELI10/01.10.2020 of the Romanian Governmentthe European Union,the Romanian Governmentthe Health Program,within the project“Medical Applications of High-Power Lasers—Dr.LASER”SMIS Code:326475the IOSIN funds for research infrastructures of national interest.
文摘We propose a novel scheme for the population and depletion of nuclear isomers.This scheme combines the γ photons with energiesà 10 keV emitted during the interaction of a contemporary high-intensity laser pulse with a plasma and one or multiple photon beams supplied by intense lasers.Owing to nonlinear effects,two-or multiphoton absorption dominates over the conventional multistep one-photon process for an optimized γ flash.Moreover,this nonlinear effect can be greatly enhanced with the help of externally supplied low-energy photons coming from another laser.These low-energy photons act such that the effective cross-section experienced by the γ photons becomes tunable,growing with the intensity I_(0) of the beam.Assuming I_(0)~10^(18) W·cm^(-2) for the photon beam,an effective cross-section as large as 10^(-21)-10^(-28) cm^(2) for the γ photons can be achieved.Thus,with state-of-the-art 10 PW laser facilities,the yields from two-photon absorption can reach 10^(6)-10^(9) isomers per shot for selected states that are separated from their ground state by E2 transitions.Similar yields for transitions with higher multipolarities can be accommodated by multiphoton absorption with additional photons provided.
文摘This research investigates the design and optimization of a photovoltaic(PV)water pumping system to address seasonal water demands across five locations with varying elevation heads.The systemdraws water froma deep well with a static water level of 30mand a dynamic level of 50m,serving agricultural and livestock needs.The objective of this study is to accurately size a PV system that balances energy generation and demand while minimizing grid dependency.Meanwhile,the study presents a comprehensivemethodology to calculate flowrates,pumping power,daily energy consumption,and system capacity.Therefore,the PV system rating,energy output,and economic performance were evaluated using metrics such as discounted payback period(DPP),net present value(NPV),and sensitivity analysis.The results show that a 2.74 kWp PV system is optimal,producing 4767 kWh/year to meet the system’s annual energy demand of 4686 kWh.In summer,energy demand peaks at 1532.7 kWh,while in winter,it drops to 692.1 kWh.Meanwhile,flow rates range from 11.71 m^(3)/h at 57 m head to 10.49 m^(3)/h at 70 m head,demonstrating the system’s adaptability to diverse hydraulic conditions.Economic analysis reveals that at a 5%interest rate and an electricity price of$0.15/kWh,the NPV is$6981.82 with a DPP of 3.76 years.However,a 30%increase in electricity prices improves the NPV to$10,005.18 and shortens the DPP to 2.76 years,whereas a 20%interest rate reduces the NPV to$1038.79 and extends the DPP to 6.08 years.Nevertheless,the annual PV energy generation exceeds total energy demand by 81 kWh,reducing grid dependency and lowering electricity costs.Additionally,the PV system avoids approximately 3956.6 kg of CO_(2) emissions annually,underscoring its environmental benefits over traditional pumping systems.As a result,this study highlights the economic and environmental viability of PV-powered water pumping systems,offering actionable insights for sustainable energy solutions in agriculture.
文摘The study was carried out in the Tahoua region at the market gardening sites of the Taddis 1 and 2 valley. Small-scale pumping irrigation is one of the most interesting uses of solar energy. The objective of this study is to carry out a comparative analysis of two dewatering pumping systems (Solar Kit and GMP) for water mobilization on a certain number of criteria such as sustainable use, economic aspect and performance. To achieve this, the adapted methodology consisted first of all in the development of a data collection tool in the field. Then flow measurements, estimation of fuel consumption, pressure height, etc., were carried out. Thus, the data collection involved a sample of 120 irrigators who had to use the two (2) types of pumping systems. The collected data were analyzed and processed with appropriate software. The results of the study show that the two pumping systems studied have strengths and constraints. Thus, the solar pumping system has a significant investment cost, very low maintenance and a low operating cost. On the other hand, the system with a generator has a relatively low investment cost (25 to 30 times less than solar), but a relatively high operating, upkeep and maintenance cost. He adds that these assets and constraints must be taken into consideration when an investment is made. This study shows that 74% of producers use GMP compared to 26% who use the Solar Kit. But in practice, the Solar Kit is more reliable for producers from the point of view of planted area, environmental management and investment costs, supply of fuel and lubricant. These results indicate better performance of the solar pumping system compared to GMP at the study sites.
文摘Background Acute Myocardial Infarction(AMI)is a critical and commonly encountered condition in the field of cardiovascular medicine.When AMI is complicated by cardiogenic shock(CS),the clinical scenario becomes significantly more complex and perilous,with a marked increase in patient mortality.Currently,traditional thera-peutic approaches such as intra-aortic balloon pumping(IABP)have demonstrated efficacy in improving myocardi-al perfusion and hemodynamics.However,the supportive capacity of IABP is limited in patients with severe heart failure.In recent years,extracorporeal membrane oxygenation(ECMO),as an advanced extracorporeal circulatory support technology,has been increasingly utilized in clinical practice,offering a novel therapeutic option for pa-tients with severe heart failure.This study aimed to investigate the clinical efficacy of combining IABP and ECMO in patients with AMI complicated by CS,evaluating its impact on myocardial injury,hemodynamic stability,and clinical outcomes.Methods This study retrospectively analyzed the clinical data of 52 patients with AMI compli-cated by CS admitted to our hospital between May 2023 and May 2024.Based on the treatment methods,the pa-tients were divided into an ECMO group(n=26)and a non-ECMO group(n=26).Post-treatment comparisons were made between the two groups regarding myocardial injury markers such as cardiac troponin I,lactate,and creatine kinase-MB,hemodynamic parameters such as mean arterial pressure,cardiac output,and central venous pressure,and the incidence of complications such as acute kidney injury,bleeding,infection.The primary endpoint of this study was the post-treatment mortality rate and the incidence of complications.Secondary endpoints included changes in myocardial injury markers[cardiac troponin I(cTnI),lactic acid(LAC),creatine kinase isoenzymes(CK-MB)]and improvements in hemodynamic parameters[mean arterial pressure(MAP),cardiac output(CO),central venous pressure(CVP)].The results of multivariate regression analyses were used to explore the incidence of EC-MO complications.Results After treatment,the levels of myocardial injury markers such as cTnI,LAC,and CK-MB in ECMO group were significantly lower than non-ECMO group(P<0.05);MAP and CO in ECMO group were significantly higher than non-ECMO group,while CVP was significantly lower(P<0.05);the mortality rate and the incidence of complications in ECMO group were lower than non-ECMO group(P<0.05).Further multivariate re-gression analysis showed that age,smoking,hyperlipidaemia and diabetes could affect the incidence of ECMO complications(P<0.05).Conclusions The combined use of IABP and ECMO exhibits substantial therapeutic benefits,including the mitigation of myocardial injury,enhancement of hemodynamic stability,and improvement in clinical prognosis among patients with AMI complicated by CS.Clinicians applying ECMO therapy should pay particular attention to older patients or those with concomitant diabetes mellitus or hyperlipidemia,as they might re-quire more intensive monitoring and prophylactic measures to mitigate the occurrence of complications.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2905503)the National Natural Science Foundation of China(Grant Nos.62035016,62105200,62475146,and 62341508).
文摘Coupled-waveguide devices are essential in photonic integrated circuits for coupling,polarization handling,and mode manipulation.However,the performance of these devices usually suffers from high wavelength and structure sensitivity,which makes it challenging to realize broadband and reliable on-chip optical functions.Recently,topological pumping of edge states has emerged as a promising solution for implementing robust optical couplings.In this paper,we propose and experimentally demonstrate broadband on-chip mode manipulation with very large fabrication tolerance based on the Rice–Mele modeled silicon waveguide arrays.The Thouless pumping mechanism is employed in the design to implement broadband and robust mode conversion and multiplexing.The experimental results prove that various mode-order conversions with low insertion losses and intermodal crosstalk can be achieved over a broad bandwidth of 80 nm ranging from 1500 to 1580 nm.Thanks to such a topological design,the device has a remarkable fabrication tolerance of±70 nm for the structural deviations in waveguide width and gap distance,which is,to the best of our knowledge,the highest among the coupled-waveguide mode-handling devices reported so far.As a proof-of-concept experiment,we cascade the topological mode-order converters to form a four-channel mode-division multiplexer and demonstrate the transmission of a 200-Gb/s 16-quadrature amplitude modulation signal for each mode channel,with the bit error rates below the 7%forward error correction threshold of 3.8×10^(-3).We reveal the possibility of developing new classes of broadband and fabrication-tolerant coupled-waveguide devices with topological photonic approaches,which may find applications in many fields,including optical interconnects,quantum communications,and optical computing.
基金supported by the Nanjing University of Posts and Telecommunications Foundation,China(Grant Nos.JUH219002 and JUH219007)the Key R&D Program of Shandong Province,China(Grant No.2021CXGC010202)。
文摘In this paper,we present a high peak power passively Q-switched intracavity frequency-doubled green laser based on an efficient LED-pumped Nd:YAG dual-rod laser module.In quasi-continuous wave(QCW)running operation,the average output power of the fundamental laser at 1064 nm reaches as high as 20.98 W at a repetition rate of 50 Hz with a maximum single pulse energy of 419.6 mJ,corresponding to a maximum optical conversion efficiency of 38.8%and a slope efficiency of 41%.
基金We would like to thank the associate editor and the reviewers for their constructive comments.This work was supported in part by the National Natural Science Foundation of China under Grant 62203234in part by the State Key Laboratory of Robotics of China under Grant 2023-Z03+1 种基金in part by the Natural Science Foundation of Liaoning Province under Grant 2023-BS-025in part by the Research Program of Liaoning Liaohe Laboratory under Grant LLL23ZZ-02-02.
文摘High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well operations.Deep learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis method.However,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational effort.Additionally,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different moments.Thus,there is heterogeneity in field data,which can dramatically impair the diagnostic accuracy.To solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this paper.First,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC data.Subsequently,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data heterogeneity.Finally,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the 4S-TFSM.Experiments on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational cost.To the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS.
基金supported by the National Natural Science Foundation of China(Nos.51922023,61874011)Fundamental Research Funds for the Central Universities(E1EG6804)
文摘As an emerging technology to convert environmental high-entropy energy into electrical energy,triboelectric nanogenerator(TENG)has great demands for further enhancing the service lifetime and output performance in practical applications.Here,an ultra-robust and high-performance rotational triboelectric nanogenerator(R-TENG)by bearing charge pumping is proposed.The R-TENG composes of a pumping TENG(P-TENG),an output TENG(O-TENG),a voltage-multiplying circuit(VMC),and a buffer capacitor.The P-TENG is designed with freestanding mode based on a rolling ball bearing,which can also act as the rotating mechanical energy harvester.The output low charge from the P-TENG is accumulated and pumped to the non-contact O-TENG,which can simultaneously realize ultralow mechanical wear and high output performance.The matched instantaneous power of R-TENG is increased by 32 times under 300 r/min.Furthermore,the transferring charge of R-TENG can remain 95%during 15 days(6.4×10^(6)cycles)continuous operation.This work presents a realizable method to further enhance the durability of TENG,which would facilitate the practical applications of high-performance TENG in harvesting distributed ambient micro mechanical energy.
基金National Key Research and De-velopment Program of China(Grant No.2023YFA1406603)the National Natural Science Foundation of China(Grant Nos.52071079,12274071,12374112,and T2394473)Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2023ZB491).
文摘The spin pumping effect in magnetic heterostructures and multilayers is a highly effective method for the generationand transmission of spin currents. In the increasingly prominent synthetic antiferromagnetic structures, the two ferromagneticlayers demonstrate in-phase and out-of-phase states, corresponding to acoustic and optical precession modes. Withinthis context, our study explores the spin pumping effect in Py/Ru/Py synthetic antiferromagnetic structures across differentmodes. The heightened magnetic damping resulting from the spin pumping effect in the in-phase state initially decreaseswith increasing Py thickness before stabilizing. Conversely, in the out-of-phase state, the amplified damping exceeds thatof the in-phase state, suggesting a greater spin relaxation within this configuration, which demonstrates sensitivity to alterationsin static exchange interactions. These findings contribute to advancing the application of synthetic antiferromagneticstructures in magnonic devices.
基金supported by the National Natural Science Foundation of China(No.61505160)the Innovation Capability Support Program of Shaanxi (No.2018KJXX-042)+2 种基金the Natural Science Basic Research Program of Shaanxi(No.2019JM-084)the State Key Laboratory of Transient Optics and Photonics(No.SKLST202108)the Postgraduate Innovation and Practice Ability Development Fund of Xi’an Shiyou University(No.YCS22213174)。
文摘A novel high quality-factor(Q)micro-ring resonator(MRR)structure based on the Si_(3)N_(4) ridge-slot waveguide is proposed,and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb.We optimized the structure of MRR by the finite element method and precise dispersion engineering,which finally obtained the suitable MRR geometry with negative dispersion characteristics at 1550 nm,having Q of 1.7×10^(7)and the absorption loss as low as 2.6×10^(-5) dB/cm.The simulation model of generating dual-comb is established as coupled Lugiato-Lefever equation(LLE),which takes the higher order dispersion,cross-phase modulation(XPM),multiphoton absorption,and external pumping into account.Solved by the split-step Fourier method(SSFM)and the fourth-order Runge-Kutta(RK4)method,the numerical results show that the generated dual-comb is periodically equally spaced distribution,but with slightly different intensities in the time domain.In the frequency domain,there are 64 comb teeth with intensities higher than-100 dBm with a bandwidth of 120 nm.Particularly,in the case of bicolor orthogonal polarization pumping,a smaller amount of detuning does not greatly affect the bandwidth of the dual-comb.
文摘In the dry tropical zone where access to water is increasingly difficult for populations, solar pumping units are increasingly installed to provide water to population. In the local market, there are essentially two types of solar panels, namely monocrystalline and polycrystalline. However, the part of the local market is more dominated by the polycrystalline panel. In this work, comparative studies are carried out in order to characterize the two types of solar panels with regard to local constraints. Tests were carried out over the course of the sun to establish the performance of each type. The panels used have the same electrical characteristics and are connected to loads with same characteristics. Under the set operating conditions, the monocrystalline panel presents more performance than the polycrystalline panel. Although the local market is dominated by the polycrystalline panel, dust deposition tests on the surface of the panels show that the performance of the polycrystalline panel is more affected compared to the performance of the monocrystalline panel.
文摘This article examines the determinants of the adoption of solar pumping systems (PV) by vegetable farmers in the Niayes area of Senegal. To measure the determinants, we used a sequential logit model to translate the adoption process from becoming aware of solar pumping systems to testing them, i.e. using them at least once, and then continuing to use them over time. The results show that the main variables affecting awareness of the use of solar pumping systems (PV) are age, marital status, experience, access to credit, the farmer’s knowledge of climate change, the farmer’s origin in the Thiès region and length of time in the Niayes area. The first use of PVs is influenced by factors such as the size of the plot, the distance of the plot from the main road or from the market. Finally, the decision to adopt or continue use is influenced by gender, experience, household size and access to credit. Surprisingly, access to credit does not affect the first use of solar pumping systems, but plays a key role in their continued use.
文摘Tonoplast-enriched vesicles were prepared from suspension-cultured Populus euphratica Oliv. cells by differential centrifugation and discontinuous sucrose density gradient centrifugation. The properties of the proton pumping activity of H+-ATPases in tonoplast vesicles were studied by acridine orange fluorescent quenching measured at 22 degreesC. The proton pumping activity of ATPase was ATP-dependent with apparent Michaelis-Menten Constant (K-m) for ATP about 0.65 mmol/L. The optimal pH for H+-ATPases activity was 7.5. The proton pumping activity of H+-ATPase could be initiated by some divalent cations, Mg2+ being highly efficient, much more than Fe2+; and Ca2+, Cu2+ and Zn2+ were inefficient under the experimental condition. The proton translocation could be stimulated by halide anions, with potencies decreasing in the order Cl- > Br- > I- > F-. The proton pumping activity was greatly inhibited by N-ethylmaleimide (NEM), N, N'-dicyclohexylcarbodiimide (DCCD), NO3- and Bafilomycin A(1), but not by orthovanadate and azide. These results demonstrated that the H+-ATPase in the tonoplast of Populus euphratica belonged to vacuolar type ATPase. This work was the first time that tonoplast-enriched vesicles were isolated from Populus euphratica cells.
文摘Using the Keldysh-Green function,we present a theoretical study on the electron transport properties of two coupled quantum dots under optical pumping. Plateaus in the I-V curve and resonant peaks in the transmission coefficient occur and can be explained by the local electron density of states in the quantum dots. The effects of the optical pumping frequency and intensity on the transport properties of the system are also discussed. The electron dynamical localization phenomenon occurs when the optical pumping frequency is equal to the discrete hole energy level. This result can be used to realize optical control switches.
文摘Obtaining petroleum at the cost of electrical energy is a common problem in almost all oil fields, and it is mainly caused by low duty radio of induction motor used in beam pumping units. Traditional beam-pumping units have many intrinsic disadvantages such as low efficiency, complex transmission devices, poor flexibility, tremendous volume and weight in long stroke, etc.Therefore, a novel direct driven linear electromagnetic pumping unit (EMPU) has been developed by combining oil extraction technology with linear motor technology. The thrust of EMPU matches the changing of suspension center load to improve the system efficiency and cut down the consumption of energy. Based on previous experience, a small-scale prototype was developed and a simulation was conducted with it. Both theoretical analyses and experimental study showed that the problems exiting in beam pumping units can be solved with EMPU system, and this is a new method which can be used to solve high energy waste in oil fields.
基金The National Natural Science Foundation of China ( No. 50476022 )Ministries and Commissions of Science and Technology of Shanghai Government (No. 03DZ 14014)
文摘Cryogenic ground supporting equipment (CGSE) developed for international cooperation scientific experimental item AMS-02 is the ground supporting and cooling system, which will complete the cooling process of the superconductor of AMS-02 from ambient temperature to 1.8 K. Obtaining 1.8 K He Ⅱ by vacuum-pumping is discussed in detail and compared with the other three schemes. The results show that the scheme of vacuum-pumping not only could meet the requirement of the project much better but also has higher reliability compared with other schemes. To select the vacuum pump, the energy conservation model is presented according to the experimental system of CGSE. Therefore, the pumping speed is also determined.
文摘The aim of this study was to evaluate the effects of pumping height and repeated pumping on the generalized stress response and gross injuries in harvest sized Atlantic salmon. Fish pumped from a net pen at either high (5.2 m) or low (3.6 m) pumping heights showed an elevated, but not severe physiological stress response (pH, pCO<sub>2</sub>, lactate, potassium, haematocrit, and sodium) compared to fish netted (not pumped), while effects of different pumping heights were overall not demonstrated. Repeated pumping (either 3 or 6 times) also caused an increase in stress response (pH, pCO<sub>2</sub>, pO<sub>2</sub>, lactate, potassium and sodium) compared to control fish, and a positive dose-response relationship was found for lactate. No fish died as a result of pumping, nor were injuries observed that could exclusively be attributed to pumping. In conclusion, although elevated from the control groups, the stress response following increasing pumping height and repeated pumping as conducted in these experiments were not indicative of causing severe stress or injuries.
