Benefiting from the abrupt phase changes within subwavelength thicknesses,metasurfaces have been widely applied for lightweight and compact optical systems.Simultaneous broadband and high-efficiency characteristics ar...Benefiting from the abrupt phase changes within subwavelength thicknesses,metasurfaces have been widely applied for lightweight and compact optical systems.Simultaneous broadband and high-efficiency characteristics are highly attractive for the practical implementation of metasurfaces.However,current metasurface devices mostly adopt discrete micro/nano structures,which rarely realize both merits simultaneously.In this paper,dielectric metasurfaces composed of quasi-continuous nanostrips are proposed to overcome this limitation.Via quasi-continuous nanostrips metasurface,a normal focusing metalens and a superoscillatory lens overcoming the diffraction limit are designed and experimentally demonstrated.The quasi-continuous metadevices can operate in a broadband wavelength ranging from 450 nm to 1000nm and keep a high power efficiency.The average efficiency of the fabricated metalens reaches 54.24%,showing a significant improvement compared to the previously reported metalenses with the same thickness.The proposed methodology can be easily extended to design other metadevices with the advantages of broadband and high-efficiency in practical optical systems.展开更多
To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put fo...To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put forward.The carbonation effect of modified recycled coarse aggregate with three different carbonation methods was evaluated,and water absorption,apparent density and crush index of modified recycled coarse aggregate were measured.Combined with XRD,SEM,and MIP microscopic analysis,the high-efficiency carbonation strengthening mechanism of modified recycled coarse aggregate was revealed.The experimental results show that,compared with the non-carbonated recycled coarse aggregate,the physical and microscopic properties of carbonated recycled coarse aggregate are improved.The method of carbonation with nano-SiO_(2) pre-soaking can realize the high-efficiency carbonation of recycled coarse aggregate,for modified recycled coarse aggregate with the method,water absorption is reduced by 23.03%,porosity is reduced by 44.06%,and the average pore diameter is 21.82 nm.The high-efficiency carbonation strengthening mechanism show that the pre-socked nano-SiO_(2) is bound to the hydration product Ca(OH)_(2) of the old mortar with nano-scale C-S-H,which can improve the CO_(2) absorption rate,accelerate the carbonation reaction,generate more stable CaCO_(3) and nano-scale silica gel,and bond to the dense three-dimensional network structure to realize the bidirectional enhancement of nano-materials and pressurized carbonation.It is concluded that the method of carbonation with nano-SiO_(2) pre-soaking is a novel high-efficiency carbonation modification of recycled coarse aggregate.展开更多
The unique advantages of one-dimensional(1D)oriented nanostructures in light-trapping and chargetransport make them competitive candidates in photovoltaic(PV)devices.Since the emergence of perovskite solar cells(PSCs)...The unique advantages of one-dimensional(1D)oriented nanostructures in light-trapping and chargetransport make them competitive candidates in photovoltaic(PV)devices.Since the emergence of perovskite solar cells(PSCs),1D nanostructured electron transport materials(ETMs)have drawn tremendous interest.However,the power conversion efficiencies(PCEs)of these devices have always significantly lagged behind their mesoscopic and planar counterparts.High-efficiency PSCs with 1D ETMs showing efficiency over 22%were just realized in the most recent studies.It yet lacks a comprehensive review covering the development of 1D ETMs and their application in PSCs.We hence timely summarize the advances in 1D ETMs-based solar cells,emphasizing on the fundamental and optimization issues of charge separation and collection ability,and their influence on PV performance.After sketching the classification and requirements for high-efficiency 1D nanostructured solar cells,we highlight the applicability of 1D TiO_(2)nanostructures in PSCs,including nanotubes,nanorods,nanocones,and nanopyramids,and carefully analyze how the electrostatic field affects cell performance.Other kinds of oriented nanostructures,e.g.,ZnO and SnO_(2)ETMs,are also described.Finally,we discuss the challenges and propose some potential strategies to further boost device performance.This review provides a broad range of valuable work in this fast-developing field,which we hope will stimulate research enthusiasm to push PSCs to an unprecedented level.展开更多
[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were...[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were determined.[Results]The yield of Shengfeier,Xiuyu 170 and Xihulu 309 increased by 11.4%,6.9%and 4.6%,respectively compared with S68(control),and zucchini was straight,looked pleasing to the eye,and had strong disease resistance.[Conclusions]The zucchini varieties were selected and the high-quality,high-yield and high-efficiency cultivation techniques were integrated.展开更多
This paper aims to solve large-scale and complex isogeometric topology optimization problems that consumesignificant computational resources. A novel isogeometric topology optimization method with a hybrid parallelstr...This paper aims to solve large-scale and complex isogeometric topology optimization problems that consumesignificant computational resources. A novel isogeometric topology optimization method with a hybrid parallelstrategy of CPU/GPU is proposed, while the hybrid parallel strategies for stiffness matrix assembly, equationsolving, sensitivity analysis, and design variable update are discussed in detail. To ensure the high efficiency ofCPU/GPU computing, a workload balancing strategy is presented for optimally distributing the workload betweenCPU and GPU. To illustrate the advantages of the proposedmethod, three benchmark examples are tested to verifythe hybrid parallel strategy in this paper. The results show that the efficiency of the hybrid method is faster thanserial CPU and parallel GPU, while the speedups can be up to two orders of magnitude.展开更多
The high-efficiency planting mode for five crops a year of fresh edible "faba bean/spring maize+soybean-autumn maize/autumn soybean" was introduced, and its yield and economic benefits were compared with the planti...The high-efficiency planting mode for five crops a year of fresh edible "faba bean/spring maize+soybean-autumn maize/autumn soybean" was introduced, and its yield and economic benefits were compared with the planting mode of three crops a year of "faba bean-spring maize/red bean". The results showed that the planting method for fresh edible "faba bean/spring maize+soybean-autumn maize/autumn soybean" was much easier to operate with the input-output ratio of about185.6%, and its yield and economic benefits were 2.09 and 1.83 times of that of the planting mode for three crops a year, significantly improving the agricultural yield and income of farmers. In addition, the cropping index of the planting mode for fresh edible fresh edible "faba bean/spring maize +soybean-autumn maize/autumn soybean" reached up to 350%, and planting faba bean once a year and soybean twice a year could make the biological fixation amount of nitrogen increase 350-450kg/m^2, which equaled to up to 700 kg/m^2 of urea, showing significant ecological and social benefits. Based on the comparison results, the high-yield culture techniques of the planting mode of fresh edible "faba bean/spring maize+soybean-autumn maize/autumn soybean" were summarized.展开更多
Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters...Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters,as the core technology for energy conversion and control,play a crucial role in enhancing the efficiency and stability of renewable energy systems.This paper explores the basic principles and functions of power electronics converters and their specific applications in photovoltaic power generation,wind power generation,and energy storage systems.Additionally,it analyzes the current innovations in high-efficiency energy conversion,multilevel conversion technology,and the application of new materials and devices.By studying these technologies,the aim is to promote the widespread application of power electronics converters in renewable energy systems and provide theoretical and technical support for achieving sustainable energy development.展开更多
We propose a controllable high-efficiency electrostatic surface trap for cold polar molecules on a chip by using two insulator-embedded charged rings and a grounded conductor plate. We calculate Stark energy structure...We propose a controllable high-efficiency electrostatic surface trap for cold polar molecules on a chip by using two insulator-embedded charged rings and a grounded conductor plate. We calculate Stark energy structure pattern of ND3 molecules in an external electric field using the method of matrix diagonalization. We analyze how the voltages that are applied to the ring electrodes affect the depth of the efficient well and the controllability of the distance between the trap center and the surface of the chip. To obtain a better understanding, we simulate the dynamical loading and trapping processes of ND3 molecules in a |J, KM = |1,-1 state by using classical Monte–Carlo method. Our study shows that the loading efficiency of our trap can reach ~ 88%. Finally, we study the adiabatic cooling of cold molecules in our surface trap by linearly lowering the potential-well depth(i.e., lowering the trapping voltage), and find that the temperature of the trapped ND3 molecules can be adiabatically cooled from 34.5 m K to ~ 5.8 m K when the trapping voltage is reduced from-35 k V to-3 k V.展开更多
A new thermal model with triangular heat flux distribution is given in high-efficiency deep grinding. The mathematical expressions are driven to calculate the surface temperature. The transient behavior of the maximum...A new thermal model with triangular heat flux distribution is given in high-efficiency deep grinding. The mathematical expressions are driven to calculate the surface temperature. The transient behavior of the maximum temperature on contact area is investigated in different grinding conditions with a J-type thermocouple. The maximum contact temperatures measured in different conditions are found to be between 1 000 ℃ and 1 500 ℃ in burn-out conditions. The experiment results show good agreement with the new thermal model.展开更多
We demonstrate a high-emciency mid-infrared picosecond optical parametric oscillator (OPO) based on MgO doped periodically poled lithium niobate (MgO:PPLN) with a laser diode array (LDA) pumped Innoslab amplifi...We demonstrate a high-emciency mid-infrared picosecond optical parametric oscillator (OPO) based on MgO doped periodically poled lithium niobate (MgO:PPLN) with a laser diode array (LDA) pumped Innoslab amplifier as the pumping source. Under a 16 W synchronously pumping power, 4.5 W of idler light at 2896nm is obtained. A tuning range of idler light from 2688nm to 3016nm is achieved, within which the highest optical-optical conversion ettlciency from pump power to OPO output is 35.1%. Moreover, a signal light of -500mW from 1644 to 1700nm with a repetition rate of 233.8 MHz is generated.展开更多
In this paper,the structure and characteristics of the NS high-efficiency composite trays based on the doublelayer aperture jet sieve plate and compositely structured packing were investigated.The effect of aperture a...In this paper,the structure and characteristics of the NS high-efficiency composite trays based on the doublelayer aperture jet sieve plate and compositely structured packing were investigated.The effect of aperture and opening ratio of plate on the fluid dynamics of the NS high-efficiency composite trays,such as the dry tray pressure drop,the wet tray pressure drop,the entrainment,the froth height,the leakage and mass transfer characteristics,were investigated.As a result, the low pressure drop,the high efficiency and the high capacity are the main advantages of the NS high-efficiency composite trays compared to other types of trays.According to this study,small aperture is useful for reducing the pressure drop and entrainment with a high mass transfer efficiency;while large aperture can achieve high capacity and efficiency in a broader operating range at the same pressure drop and entrainment.展开更多
The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base edit...The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.展开更多
The Si tandem solar cells composes of III-V, II-VI, chalcogenide and perovskite top cells and Si bottom cells are very attractive for creation of new markets. The perovskite/Si tandem solar cells are thought to be one...The Si tandem solar cells composes of III-V, II-VI, chalcogenide and perovskite top cells and Si bottom cells are very attractive for creation of new markets. The perovskite/Si tandem solar cells are thought to be one of the most promising PV devices because of high-efficiency and low-cost potential. However, efficiencies of perovskite/Si tandem solar cells with an efficiency of 29.8% are lower compared to 39.5% with III-V 3-junction tandem solar cells and 35.9% with III-V/Si 3-junction tandem solar cells. Therefore, it is necessary to clarify and reduce several losses of perovskite/Si tandem solar cells. This paper presents high efficiency potential of perovskite/Si tandem solar cells analyzed by using our analytical procedure and discusses about non-radiative recombination, optical and resistance losses in those tandem solar cells. The perovskite/Si 2-junction tandem solar cells is shown to have efficiency potential of 37.4% as a result of non-radiative recombination loss of 2.3%, optical loss of 2.7% and resistance loss of 3.1%. Although the perovskite/Si 3-junction tandem solar cells are thought to be very attractive because of higher efficiency with an efficiency of more than 42%, decreasing non-radiative recombination loss in wide bandgap perovskite solar cell materials is pointed out to be necessary.展开更多
The Si tandem solar cells are very attractive for realizing high efficiency and low cost. This paper overviews current status of III-V/Si tandem solar cells including our results. The analytical results for efficiency...The Si tandem solar cells are very attractive for realizing high efficiency and low cost. This paper overviews current status of III-V/Si tandem solar cells including our results. The analytical results for efficiency potential of Si tandem solar cells and loss analysis of Si bottom cells as well as bandgap energy optimization of sub-cells are presented. The 2-junction and 3-junction Si tandem solar cells have potential efficiencies of 36% and 42%, respectively. ERE (external radiative efficiency) analysis for Si solar cells is analyzed in or</span><span style="font-family:Verdana;">der to clarify properties of Si bottom solar cells. Properties of single-crystalline Si heterojunction solar cell</span><span style="font-family:Verdana;"> fabricated in this study were analyzed. The current </span><span><span style="font-family:Verdana;">status of efficiencies of our Si bottom cell, upper III-V 2-junction solar cell and III-V/Si 3-junction tandem solar cell was shown to be 5.2% and 28.6% and 33.8%. Achievement of </span><span style="white-space:nowrap;font-family:Verdana;"><i></span><span style="font-family:Verdana;"></span><i><span style="font-family:Verdana;">J</span><sub><span style="font-family:Verdana;">sc</span><span style="white-space:nowrap;font-family:Verdana;"></i></span><span style="font-family:Verdana;"></span></sub></i><span style="font-family:Verdana;"> of 12 mA/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> for Si bottom cell is necessary to realize high-efficiency 3-junction Si tandem solar cells with an efficiency of</span></span><span style="font-family:Verdana;"> more than 37%. In addition, this paper presents ERE analysis of III-V 2-junction upper solar cells for improving III-V/Si 3-junction tandem solar cells. Several ways to improve efficiency of III-V/Si 3-junction tandem solar cells by reducing non-radiative recombination, optical and resistance losses are shown.展开更多
Development of highly-efficient photovoltaic (PV) modules and expanding its application fields are significant for the further development of PV technologies and realization of innovative green energy infrastructure b...Development of highly-efficient photovoltaic (PV) modules and expanding its application fields are significant for the further development of PV technologies and realization of innovative green energy infrastructure based on PV. Especially, development of solar-powered vehicles as a new application is highly desired and very important for this end. This paper presents the impact of PV cell/module conversion efficiency on reduction in CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> emission and increase in driving range of the electric based vehicles. Our studies show that the utilization of a highly-efficient (higher than 30%) PV module enables the solar-powered vehicle to drive 30 km/day without charging in the case of light weig</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">h</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">t cars with elec</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">t</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ric mileage of 17</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">km/kWh under solar irrad</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">i</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">t</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ion of 3.7</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">kWh/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">/day, which means that the majority of the family cars in Japan can run only by the sunlight without supplying fossil fuels. Thus, it is essential to develop high-efficiency as well as low-cost solar cells and modules for automotive applications. The analytical results developed by the authors for conversion efficiency potential of various solar cells for choosing candidates of the PV modules for automotive applications are shown. Then we overview the conversion efficiency potential and recent progress of various Si tandem solar cells, such as III-V/Si, II-VI/Si, chalcopyrite/Si, and perovskite/Si tandem solar cells. The III-V/Si tandem solar cells are expected to have a high potential for various applications because of its high conversion efficiency of larger than 36% for dual-junction and 42% for triple-junction solar cells under 1-sun AM1.5 G illumination, lightweight and low-cost potentials. The analysis show</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> that III-V based multi-junction and Si based tandem solar cells are considered to be promising candidates for the automotive application. Finally, we report recent results for our 28.2% efficiency and Sharp’s 33% mechanically stacked InGaP/GaAs/Si triple-junction solar cell. In addition, new approaches which </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">are</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> suitable for automotive applications by using III-V triple-junction, and static low concentrator PV modules are also presented.展开更多
Superconducting nanowire single-photon detectors (SNSPDs) with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and t...Superconducting nanowire single-photon detectors (SNSPDs) with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and the response bandwidth. Numerical simulation by the finite-difference time-domain method shows that the photon absorption capacity of SNSPDs with a composite optical structure can be enhanced significantly by adjusting the parameters of the phase-grating and optical cavity structures at multiple frequency bands. The absorption capacity of the superconducting nanowires reaches 70%, 72%, 60.73%, 61.7%, 41.2%, and 46.5% at wavelengths of 684, 850, 732, 924, 1256, and 1426nm, respectively. The use of a composite optical structure reduces the total filling factor of superconducting nanowires to only 0.25, decreases the kinetic inductance of SNSPDs, and improves the count rates.展开更多
We present a polarization converter composed of bi-layered metal films perforated with rectangle hole pairs in each film. The proposed converter can convert the polarization of an incident linearly-polarized electroma...We present a polarization converter composed of bi-layered metal films perforated with rectangle hole pairs in each film. The proposed converter can convert the polarization of an incident linearly-polarized electromagnetic wave to its orthogonal direction with high efficiency and large bandwidth in the infrared or microwave regions.To make sure of the mechanism of polarization conversion, the current and electric-field distributions at different resonant frequencies are analyzed. It is found that the cross-polarized transmission is due to the near-field coupling between hole pairs in neighboring metal films. Finally, a prototype of the proposed converter is fabricated and measured in the microwave region. Good agreement between the experimental and simulated results is obtained.展开更多
Efficiently routing the quantum signals between different channels is essential in a quantum multichannel network.We investigate the quantum routing in a multi-cross-shaped waveguide coupled to driven three-level syst...Efficiently routing the quantum signals between different channels is essential in a quantum multichannel network.We investigate the quantum routing in a multi-cross-shaped waveguide coupled to driven three-level systems.Numerical results show that the high routing capacity transferring from the input channel to the other channels can be explicitly enhanced by effective reflection potentials. The proposed system may be utilized as a scalable quantum device to control single-photon routing.展开更多
Proceeding from the specific characteristics of PAL television signals adopted in China this paper points out that if the fs = 2fsc of sub-Nyquist sampling and DPCM encoding is used for PAL complete signal and if the ...Proceeding from the specific characteristics of PAL television signals adopted in China this paper points out that if the fs = 2fsc of sub-Nyquist sampling and DPCM encoding is used for PAL complete signal and if the blanking time is utilized to transmit code of effective area, it is possible to transmit a color TV signal over PCM three-group channel.展开更多
A high-efficiency green phosphorescent organic light emitting diode with a simplified structure is achieved that is free of a hole transport layer. The design of this kind of device structure not only saves the consum...A high-efficiency green phosphorescent organic light emitting diode with a simplified structure is achieved that is free of a hole transport layer. The design of this kind of device structure not only saves the consumption of organic materials but also greatly reduces the structural heterogeneities and effectively facilitates the charge injection into the emissive layer. The resulting green phosphorescent organic light-emitting diodes (PHOLEDs) exhibit higher electroluminescent efficiency. The maximum external quantum efficiency and current efficiency reach 23.7% and 88 cd/A, respectively. Moreover the device demonstrates satisfactory stability, keeping 23.7% and 88cd/A, 22% and 82cd/A, respectively, at a luminance of 100 and 1000cd/m2. The working mechanism for achieving high efficiency based on such a simple device structure is discussed correspondingly. The improved charge carrier injection and transport balance are proved to prominently contribute to achieve the high efficiency and great stability at high luminance in the green PHOLEDs.展开更多
基金the financial support by National Natural Science Foundation of China under contract No.61905031,61905073National Key R&D Program of China under contract No.2020YFC1522900Natural Science Foundation of Chongqing under contract No.CSTB2023NSCQMSX0992。
文摘Benefiting from the abrupt phase changes within subwavelength thicknesses,metasurfaces have been widely applied for lightweight and compact optical systems.Simultaneous broadband and high-efficiency characteristics are highly attractive for the practical implementation of metasurfaces.However,current metasurface devices mostly adopt discrete micro/nano structures,which rarely realize both merits simultaneously.In this paper,dielectric metasurfaces composed of quasi-continuous nanostrips are proposed to overcome this limitation.Via quasi-continuous nanostrips metasurface,a normal focusing metalens and a superoscillatory lens overcoming the diffraction limit are designed and experimentally demonstrated.The quasi-continuous metadevices can operate in a broadband wavelength ranging from 450 nm to 1000nm and keep a high power efficiency.The average efficiency of the fabricated metalens reaches 54.24%,showing a significant improvement compared to the previously reported metalenses with the same thickness.The proposed methodology can be easily extended to design other metadevices with the advantages of broadband and high-efficiency in practical optical systems.
基金Funded by Joint Funds of the National Natural Science Foundation of China(No.U1904188)the Jiangxi Provincial Department of Education Science and Technology Project(Nos.GJJ171079,GJJ181023,and GJJ181022)。
文摘To solve the problem of only surface carbonation and realize high-efficiency carbonation of recycled coarse aggregate,the method of carbonated recycled coarse aggregate with nano materials pre-soaking was first put forward.The carbonation effect of modified recycled coarse aggregate with three different carbonation methods was evaluated,and water absorption,apparent density and crush index of modified recycled coarse aggregate were measured.Combined with XRD,SEM,and MIP microscopic analysis,the high-efficiency carbonation strengthening mechanism of modified recycled coarse aggregate was revealed.The experimental results show that,compared with the non-carbonated recycled coarse aggregate,the physical and microscopic properties of carbonated recycled coarse aggregate are improved.The method of carbonation with nano-SiO_(2) pre-soaking can realize the high-efficiency carbonation of recycled coarse aggregate,for modified recycled coarse aggregate with the method,water absorption is reduced by 23.03%,porosity is reduced by 44.06%,and the average pore diameter is 21.82 nm.The high-efficiency carbonation strengthening mechanism show that the pre-socked nano-SiO_(2) is bound to the hydration product Ca(OH)_(2) of the old mortar with nano-scale C-S-H,which can improve the CO_(2) absorption rate,accelerate the carbonation reaction,generate more stable CaCO_(3) and nano-scale silica gel,and bond to the dense three-dimensional network structure to realize the bidirectional enhancement of nano-materials and pressurized carbonation.It is concluded that the method of carbonation with nano-SiO_(2) pre-soaking is a novel high-efficiency carbonation modification of recycled coarse aggregate.
基金supported by the National Natural Science Foundation of China(61904166,22209145)the Natural Science Foundation of Sichuan Province(2022NSFSC0258)the Fundamental Research Funds for the Central Universities(YJ2021129)。
文摘The unique advantages of one-dimensional(1D)oriented nanostructures in light-trapping and chargetransport make them competitive candidates in photovoltaic(PV)devices.Since the emergence of perovskite solar cells(PSCs),1D nanostructured electron transport materials(ETMs)have drawn tremendous interest.However,the power conversion efficiencies(PCEs)of these devices have always significantly lagged behind their mesoscopic and planar counterparts.High-efficiency PSCs with 1D ETMs showing efficiency over 22%were just realized in the most recent studies.It yet lacks a comprehensive review covering the development of 1D ETMs and their application in PSCs.We hence timely summarize the advances in 1D ETMs-based solar cells,emphasizing on the fundamental and optimization issues of charge separation and collection ability,and their influence on PV performance.After sketching the classification and requirements for high-efficiency 1D nanostructured solar cells,we highlight the applicability of 1D TiO_(2)nanostructures in PSCs,including nanotubes,nanorods,nanocones,and nanopyramids,and carefully analyze how the electrostatic field affects cell performance.Other kinds of oriented nanostructures,e.g.,ZnO and SnO_(2)ETMs,are also described.Finally,we discuss the challenges and propose some potential strategies to further boost device performance.This review provides a broad range of valuable work in this fast-developing field,which we hope will stimulate research enthusiasm to push PSCs to an unprecedented level.
文摘[Objectives]To select zucchini varieties suitable for cultivation in Zibo City and test its high-yield cultivation techniques.[Methods]Six zucchini varieties were introduced,and their commercial quality and yield were determined.[Results]The yield of Shengfeier,Xiuyu 170 and Xihulu 309 increased by 11.4%,6.9%and 4.6%,respectively compared with S68(control),and zucchini was straight,looked pleasing to the eye,and had strong disease resistance.[Conclusions]The zucchini varieties were selected and the high-quality,high-yield and high-efficiency cultivation techniques were integrated.
基金the National Key R&D Program of China(2020YFB1708300)the National Natural Science Foundation of China(52005192)the Project of Ministry of Industry and Information Technology(TC210804R-3).
文摘This paper aims to solve large-scale and complex isogeometric topology optimization problems that consumesignificant computational resources. A novel isogeometric topology optimization method with a hybrid parallelstrategy of CPU/GPU is proposed, while the hybrid parallel strategies for stiffness matrix assembly, equationsolving, sensitivity analysis, and design variable update are discussed in detail. To ensure the high efficiency ofCPU/GPU computing, a workload balancing strategy is presented for optimally distributing the workload betweenCPU and GPU. To illustrate the advantages of the proposedmethod, three benchmark examples are tested to verifythe hybrid parallel strategy in this paper. The results show that the efficiency of the hybrid method is faster thanserial CPU and parallel GPU, while the speedups can be up to two orders of magnitude.
基金Supported by the China Agriculture Research System(CARS-09)the Technological Innovation and Industrialization Project for the Rural Area of Nantong City,Jiangsu Province(H12014012)~~
文摘The high-efficiency planting mode for five crops a year of fresh edible "faba bean/spring maize+soybean-autumn maize/autumn soybean" was introduced, and its yield and economic benefits were compared with the planting mode of three crops a year of "faba bean-spring maize/red bean". The results showed that the planting method for fresh edible "faba bean/spring maize+soybean-autumn maize/autumn soybean" was much easier to operate with the input-output ratio of about185.6%, and its yield and economic benefits were 2.09 and 1.83 times of that of the planting mode for three crops a year, significantly improving the agricultural yield and income of farmers. In addition, the cropping index of the planting mode for fresh edible fresh edible "faba bean/spring maize +soybean-autumn maize/autumn soybean" reached up to 350%, and planting faba bean once a year and soybean twice a year could make the biological fixation amount of nitrogen increase 350-450kg/m^2, which equaled to up to 700 kg/m^2 of urea, showing significant ecological and social benefits. Based on the comparison results, the high-yield culture techniques of the planting mode of fresh edible "faba bean/spring maize+soybean-autumn maize/autumn soybean" were summarized.
文摘Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters,as the core technology for energy conversion and control,play a crucial role in enhancing the efficiency and stability of renewable energy systems.This paper explores the basic principles and functions of power electronics converters and their specific applications in photovoltaic power generation,wind power generation,and energy storage systems.Additionally,it analyzes the current innovations in high-efficiency energy conversion,multilevel conversion technology,and the application of new materials and devices.By studying these technologies,the aim is to promote the widespread application of power electronics converters in renewable energy systems and provide theoretical and technical support for achieving sustainable energy development.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10674047,10804031,10904037,10904060,10974055,11034002,and61205198)the National Key Basic Research and Development Program of China(Grant Nos.2006CB921604 and 2011CB921602)+2 种基金the Basic Key Program of Shanghai Municipality,China(Grant No.07JC14017)the Fundamental Research Funds for the Central Universitiesthe Shanghai Leading Academic Discipline Project,China(Grant No.B408)
文摘We propose a controllable high-efficiency electrostatic surface trap for cold polar molecules on a chip by using two insulator-embedded charged rings and a grounded conductor plate. We calculate Stark energy structure pattern of ND3 molecules in an external electric field using the method of matrix diagonalization. We analyze how the voltages that are applied to the ring electrodes affect the depth of the efficient well and the controllability of the distance between the trap center and the surface of the chip. To obtain a better understanding, we simulate the dynamical loading and trapping processes of ND3 molecules in a |J, KM = |1,-1 state by using classical Monte–Carlo method. Our study shows that the loading efficiency of our trap can reach ~ 88%. Finally, we study the adiabatic cooling of cold molecules in our surface trap by linearly lowering the potential-well depth(i.e., lowering the trapping voltage), and find that the temperature of the trapped ND3 molecules can be adiabatically cooled from 34.5 m K to ~ 5.8 m K when the trapping voltage is reduced from-35 k V to-3 k V.
基金This project is supported by National Natural Science Foundation of China (No.50475052)Provincial Natural Science Foundation of Liaoning (No.20022161)Provincial Scientific Research Plan of Education Office of Uaoning(No.202223206).
文摘A new thermal model with triangular heat flux distribution is given in high-efficiency deep grinding. The mathematical expressions are driven to calculate the surface temperature. The transient behavior of the maximum temperature on contact area is investigated in different grinding conditions with a J-type thermocouple. The maximum contact temperatures measured in different conditions are found to be between 1 000 ℃ and 1 500 ℃ in burn-out conditions. The experiment results show good agreement with the new thermal model.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61275142,61308042,and 51321091the National Key Scientific Instrument and Equipment Development Project under Grant No 2011YQ030127the China Postdoctoral Science Foundation under Grant No 2014T70633
文摘We demonstrate a high-emciency mid-infrared picosecond optical parametric oscillator (OPO) based on MgO doped periodically poled lithium niobate (MgO:PPLN) with a laser diode array (LDA) pumped Innoslab amplifier as the pumping source. Under a 16 W synchronously pumping power, 4.5 W of idler light at 2896nm is obtained. A tuning range of idler light from 2688nm to 3016nm is achieved, within which the highest optical-optical conversion ettlciency from pump power to OPO output is 35.1%. Moreover, a signal light of -500mW from 1644 to 1700nm with a repetition rate of 233.8 MHz is generated.
基金supported by the Key Project of Chinese National Programs for Fundamental Research and Development(973 Program) (contract number:2005CB221204-5)
文摘In this paper,the structure and characteristics of the NS high-efficiency composite trays based on the doublelayer aperture jet sieve plate and compositely structured packing were investigated.The effect of aperture and opening ratio of plate on the fluid dynamics of the NS high-efficiency composite trays,such as the dry tray pressure drop,the wet tray pressure drop,the entrainment,the froth height,the leakage and mass transfer characteristics,were investigated.As a result, the low pressure drop,the high efficiency and the high capacity are the main advantages of the NS high-efficiency composite trays compared to other types of trays.According to this study,small aperture is useful for reducing the pressure drop and entrainment with a high mass transfer efficiency;while large aperture can achieve high capacity and efficiency in a broader operating range at the same pressure drop and entrainment.
基金supported by the Beijing Scholars Program[BSP041]。
文摘The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.
文摘The Si tandem solar cells composes of III-V, II-VI, chalcogenide and perovskite top cells and Si bottom cells are very attractive for creation of new markets. The perovskite/Si tandem solar cells are thought to be one of the most promising PV devices because of high-efficiency and low-cost potential. However, efficiencies of perovskite/Si tandem solar cells with an efficiency of 29.8% are lower compared to 39.5% with III-V 3-junction tandem solar cells and 35.9% with III-V/Si 3-junction tandem solar cells. Therefore, it is necessary to clarify and reduce several losses of perovskite/Si tandem solar cells. This paper presents high efficiency potential of perovskite/Si tandem solar cells analyzed by using our analytical procedure and discusses about non-radiative recombination, optical and resistance losses in those tandem solar cells. The perovskite/Si 2-junction tandem solar cells is shown to have efficiency potential of 37.4% as a result of non-radiative recombination loss of 2.3%, optical loss of 2.7% and resistance loss of 3.1%. Although the perovskite/Si 3-junction tandem solar cells are thought to be very attractive because of higher efficiency with an efficiency of more than 42%, decreasing non-radiative recombination loss in wide bandgap perovskite solar cell materials is pointed out to be necessary.
文摘The Si tandem solar cells are very attractive for realizing high efficiency and low cost. This paper overviews current status of III-V/Si tandem solar cells including our results. The analytical results for efficiency potential of Si tandem solar cells and loss analysis of Si bottom cells as well as bandgap energy optimization of sub-cells are presented. The 2-junction and 3-junction Si tandem solar cells have potential efficiencies of 36% and 42%, respectively. ERE (external radiative efficiency) analysis for Si solar cells is analyzed in or</span><span style="font-family:Verdana;">der to clarify properties of Si bottom solar cells. Properties of single-crystalline Si heterojunction solar cell</span><span style="font-family:Verdana;"> fabricated in this study were analyzed. The current </span><span><span style="font-family:Verdana;">status of efficiencies of our Si bottom cell, upper III-V 2-junction solar cell and III-V/Si 3-junction tandem solar cell was shown to be 5.2% and 28.6% and 33.8%. Achievement of </span><span style="white-space:nowrap;font-family:Verdana;"><i></span><span style="font-family:Verdana;"></span><i><span style="font-family:Verdana;">J</span><sub><span style="font-family:Verdana;">sc</span><span style="white-space:nowrap;font-family:Verdana;"></i></span><span style="font-family:Verdana;"></span></sub></i><span style="font-family:Verdana;"> of 12 mA/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> for Si bottom cell is necessary to realize high-efficiency 3-junction Si tandem solar cells with an efficiency of</span></span><span style="font-family:Verdana;"> more than 37%. In addition, this paper presents ERE analysis of III-V 2-junction upper solar cells for improving III-V/Si 3-junction tandem solar cells. Several ways to improve efficiency of III-V/Si 3-junction tandem solar cells by reducing non-radiative recombination, optical and resistance losses are shown.
文摘Development of highly-efficient photovoltaic (PV) modules and expanding its application fields are significant for the further development of PV technologies and realization of innovative green energy infrastructure based on PV. Especially, development of solar-powered vehicles as a new application is highly desired and very important for this end. This paper presents the impact of PV cell/module conversion efficiency on reduction in CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> emission and increase in driving range of the electric based vehicles. Our studies show that the utilization of a highly-efficient (higher than 30%) PV module enables the solar-powered vehicle to drive 30 km/day without charging in the case of light weig</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">h</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">t cars with elec</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">t</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ric mileage of 17</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">km/kWh under solar irrad</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">i</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">t</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ion of 3.7</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">kWh/m</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">/day, which means that the majority of the family cars in Japan can run only by the sunlight without supplying fossil fuels. Thus, it is essential to develop high-efficiency as well as low-cost solar cells and modules for automotive applications. The analytical results developed by the authors for conversion efficiency potential of various solar cells for choosing candidates of the PV modules for automotive applications are shown. Then we overview the conversion efficiency potential and recent progress of various Si tandem solar cells, such as III-V/Si, II-VI/Si, chalcopyrite/Si, and perovskite/Si tandem solar cells. The III-V/Si tandem solar cells are expected to have a high potential for various applications because of its high conversion efficiency of larger than 36% for dual-junction and 42% for triple-junction solar cells under 1-sun AM1.5 G illumination, lightweight and low-cost potentials. The analysis show</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> that III-V based multi-junction and Si based tandem solar cells are considered to be promising candidates for the automotive application. Finally, we report recent results for our 28.2% efficiency and Sharp’s 33% mechanically stacked InGaP/GaAs/Si triple-junction solar cell. In addition, new approaches which </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">are</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> suitable for automotive applications by using III-V triple-junction, and static low concentrator PV modules are also presented.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00100 and 2011CBA00200the National Natural Science Foundation of China under Grant Nos 11227904 and 61101012+1 种基金the National High-Technology ResearchDevelopment Program of China under Grant No 2011AA010204the Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves
文摘Superconducting nanowire single-photon detectors (SNSPDs) with a composite optical structure composed of phase-grating and optical cavity structures are designed to enhance both the system detection efficiency and the response bandwidth. Numerical simulation by the finite-difference time-domain method shows that the photon absorption capacity of SNSPDs with a composite optical structure can be enhanced significantly by adjusting the parameters of the phase-grating and optical cavity structures at multiple frequency bands. The absorption capacity of the superconducting nanowires reaches 70%, 72%, 60.73%, 61.7%, 41.2%, and 46.5% at wavelengths of 684, 850, 732, 924, 1256, and 1426nm, respectively. The use of a composite optical structure reduces the total filling factor of superconducting nanowires to only 0.25, decreases the kinetic inductance of SNSPDs, and improves the count rates.
文摘We present a polarization converter composed of bi-layered metal films perforated with rectangle hole pairs in each film. The proposed converter can convert the polarization of an incident linearly-polarized electromagnetic wave to its orthogonal direction with high efficiency and large bandwidth in the infrared or microwave regions.To make sure of the mechanism of polarization conversion, the current and electric-field distributions at different resonant frequencies are analyzed. It is found that the cross-polarized transmission is due to the near-field coupling between hole pairs in neighboring metal films. Finally, a prototype of the proposed converter is fabricated and measured in the microwave region. Good agreement between the experimental and simulated results is obtained.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11247032 and 61765007the Scientific Research Foundation of the Jiangxi Provincial Education Department under Grant Nos GJJ170556 and GJJ180424
文摘Efficiently routing the quantum signals between different channels is essential in a quantum multichannel network.We investigate the quantum routing in a multi-cross-shaped waveguide coupled to driven three-level systems.Numerical results show that the high routing capacity transferring from the input channel to the other channels can be explicitly enhanced by effective reflection potentials. The proposed system may be utilized as a scalable quantum device to control single-photon routing.
文摘Proceeding from the specific characteristics of PAL television signals adopted in China this paper points out that if the fs = 2fsc of sub-Nyquist sampling and DPCM encoding is used for PAL complete signal and if the blanking time is utilized to transmit code of effective area, it is possible to transmit a color TV signal over PCM three-group channel.
基金Supported by the Nanjing University of Telecommunication and Posts under Grant No NY212010the National Natural Science Foundation of China under Grant Nos 91233117,50973104 and 51333007+2 种基金the Natural Science Fund of Jiangsu Province under Grant No BK2012834the National Basic Research Program of China under Grant No 2015CB932200the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘A high-efficiency green phosphorescent organic light emitting diode with a simplified structure is achieved that is free of a hole transport layer. The design of this kind of device structure not only saves the consumption of organic materials but also greatly reduces the structural heterogeneities and effectively facilitates the charge injection into the emissive layer. The resulting green phosphorescent organic light-emitting diodes (PHOLEDs) exhibit higher electroluminescent efficiency. The maximum external quantum efficiency and current efficiency reach 23.7% and 88 cd/A, respectively. Moreover the device demonstrates satisfactory stability, keeping 23.7% and 88cd/A, 22% and 82cd/A, respectively, at a luminance of 100 and 1000cd/m2. The working mechanism for achieving high efficiency based on such a simple device structure is discussed correspondingly. The improved charge carrier injection and transport balance are proved to prominently contribute to achieve the high efficiency and great stability at high luminance in the green PHOLEDs.