The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-do...The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.展开更多
Graphene,owing to its exceptional electronic,optical,thermal,and mechanical properties,has emerged as a highly promising material.Currently,the synthesis of large-area graphene films on metal substrates via chemical v...Graphene,owing to its exceptional electronic,optical,thermal,and mechanical properties,has emerged as a highly promising material.Currently,the synthesis of large-area graphene films on metal substrates via chemical vapor deposition remains the predominant approach for producing high-quality graphene.To realize the potential applications of graphene,it is essential to transfer graphene films to target substrates in a manner that is non-destructive,clean,and efficient,as this significantly affects the performance of graphene devices.This review examines the current methods for graphene transfer from three perspectives:non-destructive transfer,clean transfer,and high-efficiency transfer.It analyzes and compares the advancements and limitations of various transfer techniques.Finally,the review identifies the key challenges faced by current graphene transfer methods and anticipates future developmental prospects.展开更多
Through literature analysis and case study, the introduction history, variety selection (high bush, half high bush, low bush) and regional cultivation techniques of blueberry in China were summarized, and the practica...Through literature analysis and case study, the introduction history, variety selection (high bush, half high bush, low bush) and regional cultivation techniques of blueberry in China were summarized, and the practical effects of precision cultivation (water and fertilizer integration, wild planting) and under-forest economic model (forest-blueberry-fungus system, ecological tourism) were evaluated. It provided a technical reference for expanding the planting scale of blueberry and improving the fruit quality.展开更多
Gamma titanium-aluminum intermetallic compounds(γ-TiAl)have gained considerable attentions in the aerospace industry due to their exceptional thermal resilience and comprehensive attributes,making them a prime exampl...Gamma titanium-aluminum intermetallic compounds(γ-TiAl)have gained considerable attentions in the aerospace industry due to their exceptional thermal resilience and comprehensive attributes,making them a prime example of lightweight and advanced materials.To address the frequent occurrence of burns and severe tool deterioration during the process of high-efficiency deep grinding(HEDG)onγ-TiAl alloys,ultrasonic vibration-assisted high-efficiency deep grinding(UVHEDG)has been emerged.Results indicate that in UVHEDG,the grinding temperature is on average 15.4%lower than HEDG due to the employment of ultrasonic vibrations,enhancing coolant penetration into the grinding area and thus reducing heat generation.Besides,UVHEDG possesses superior performance in terms of grinding forces compared to HEDG.As the material removal volume(MRV)increases,the tangential grinding force(F_(t))and normal grinding force(F_(n))of UVHEDG increase but to a lesser extent than in HEDG,with an average reduction of16.25%and 14.7%,respectively.UVHEDG primarily experiences microfracture of grains,whereas HEDG undergoes large-scale wear later in the process due to increased grinding forces.The surface roughness(R_(a))characteristics of UVHEDG are superior,with the average value of R_(a)decreasing by 46.5%compared to HEDG as MRV increases.The surface morphology in UVHEDG exhibits enhanced smoothness and a shallower layer of plastic deformation.Grinding chips generated by UVHEDG show a more shear-like shape,with the applied influence of ultrasonic vibration on chip morphology,thereby impacting material removal behaviors.These aforementioned findings contribute to enhanced machining efficiency and product quality ofγ-TiAl alloys after employing ultrasonic vibrations into HEDG.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
Metal halide perovskite solar cells(PSCs)are one of the most promising photovoltaic devices.Over time,many strategies have been adopted to improve PSC efficiency,and the certified efficiency has reached 26.1%.However,...Metal halide perovskite solar cells(PSCs)are one of the most promising photovoltaic devices.Over time,many strategies have been adopted to improve PSC efficiency,and the certified efficiency has reached 26.1%.However,only a few research groups have fabricated PSCs with an efficiency of>25%,indicating that achieving this efficiency remains uncommon.To develop the PSC industry,outstanding talent must be reserved with the latest technologies.Herein,we summarize the recent developments in high-efficiency PSCs(>25%)and highlight their effective strategies in crystal regulation,interface passivation,and component layer structural design.Finally,we propose perspectives based on current research to further enhance the efficiency and promote the commercialization process of PSCs.展开更多
The isolation of circulating tumor cells(CTCs)from complex biological samples is of paramount signifi-cance for advancing cancer diagnosis,prognosis,and treatment.However,the low concentration of CTCs and nonspecific ...The isolation of circulating tumor cells(CTCs)from complex biological samples is of paramount signifi-cance for advancing cancer diagnosis,prognosis,and treatment.However,the low concentration of CTCs and nonspecific adhesion of white blood cells(WBCs)present challenges that hinder the efficiency and purity of captured CTCs.Microfluidic-based strategies utilize precise fluid control at the micron level to incorporate specific micro/nanostructures or recognition molecules,enabling effective CTCs separation.Moreover,by employing surface modification designs that exhibit exceptional anti-adhesion properties against WBCs,the purity of isolated CTCs can be further enhanced.This review offers an in-depth explo-ration of recent advancements,challenges,and opportunities associated with microfluidic-based CTCs iso-lation from biological samples.Firstly,we will comprehensively introduce the microfluidic-based strate-gies for achieving high-efficiency CTCs isolation,which includes the morphological design of microchan-nels for physical force-based CTCs isolation and the specific modification of microchannel surfaces for affinity-based CTCs isolation.Subsequently,a review of recent research advances in microfluidic-based high-purity CTCs isolation is presented,focusing on strategies that decrease the nonspecific adhesion of WBCs through surface micro-/nanostructure construction or chemical and biological modification.Finally,we will summarize the article by providing the prospective opportunities and challenges for the future development of microfluidic-based CTCs isolation.展开更多
The preparation of Pd-based catalysts with rich electrons and a high atom dispersion rate is of great significance for improving the reactivity of cross-coupling reactions,which is a powerful tool for pharmaceutical a...The preparation of Pd-based catalysts with rich electrons and a high atom dispersion rate is of great significance for improving the reactivity of cross-coupling reactions,which is a powerful tool for pharmaceutical and fine chemical synthesis.Here,we report a PdNi single-atom alloy(SAA)catalyst in which isolated Pd single atoms are anchored onto the surface of Ni nanoparticles(NPs)applied for Suzuki coupling reactions and Heck coupling reactions.The 0.1%PdNi SAA exhibits extraordinary catalytic activity(reaction rate:17,032.25 mmol h^(-1)gPd^(-1))toward the Suzuki cross-coupling reaction between 4-bromoanisole and phenylboronic acid at 80℃for 1 h.The excellent activity is supposed to attribute to the 100 percent utilization rate of Pd atoms and the highly stable surface zero-valance Pd atoms,which provides abundant sites and electrons for the adsorption and fracture of the C-X(X=Cl,Br,I)bond.Moreover,our work demonstrates the excellent application prospect of SAAs for cross-coupling reactions.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
Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve ...Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve rice productivity is to enlarge rice growth areas, such as the northward expansion of the growth region in Heilongjiang Province, the northernmost region of China （Li et al., 2015）. However, the northward cultivation is accompanied with daylength extension and temperature decrease, which are unfavor- able for rice, a tropical short-day plant, to complete flowering and seed setting. Thus, the need for early-maturing rice cultivars with extremely low photoperiod sensitivity is urgent.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
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
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
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
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
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
Acephate pesticide contamination in agricultural production has caused serious human health problems.Metal oxide semiconductor(MOS)gas sensor can be used as a portable and promising alternative tool for efficiently de...Acephate pesticide contamination in agricultural production has caused serious human health problems.Metal oxide semiconductor(MOS)gas sensor can be used as a portable and promising alternative tool for efficiently detection of acephate.In this study,hierarchical assembled SnO_(2)nanosphere,SnO_(2)hollow nanosphere and SnO_2 nanoflower were synthesized respectively as high efficiency sensing materials to build rapid and selective acephate pesticide residues sensors.The morphologies of different SnO_(2)3 D nanostructures were characterized by various material characterization technology.The sensitive performance test results of the 3 D SnO_(2)nanomaterials towards acephate show that hollow nanosphere SnO_(2)based sensor displayed preferable sensitivity,selectivity,and rapid response(9 s)properties toward acephate at the optimal working temperature(300℃).This SnO_(2)hollow nanosphere based gas sensor represents a useful tool for simple and highly effective monitoring of acephate pesticide residues in food and environment.According to the characterization results,particularly Brunauer-Emmett-Teller(BET)and Ultraviolet-Visible Spectroscopy(UV-vis),the obvious and fast response can be attributed to the mesoporous hollow nanosphere structure and appropriate band gap of SnO_2 hollow nanosphere.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
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
An improved indirect scheme for laser positron generation is proposed. The positron yields in high-ZZ metal targets irradiated by laser produced electrons from near-critical density plasmas and underdense plasma are i...An improved indirect scheme for laser positron generation is proposed. The positron yields in high-ZZ metal targets irradiated by laser produced electrons from near-critical density plasmas and underdense plasma are investigated numerically. It is found that the positron yield is mainly affected by the number of electrons of energies up to several hundreds of MeV. Using near-critical density targets for electron acceleration, the number of high energy electrons can be increased dramatically. Through start-to-end simulations, it is shown that up to 6.78×10106.78×1010 positrons can be generated with state-of-the-art Joule-class femtosecond laser systems.展开更多
基金supported from the Natural Science Foundation Project of Shanghai(Nos.23ZR1425300 and 22ZR1426100)Experimental Technical Team Construction Project of Shanghai Education Commission(No.10110N230080)+1 种基金National Natural Science Foundation of China(No.22075183)Research and Innovation Project of Shanghai Municipal Education Commission(No.2023ZKZD54).
文摘The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.
基金supported by the National Key R&D Program of China(2020YFB2009002).
文摘Graphene,owing to its exceptional electronic,optical,thermal,and mechanical properties,has emerged as a highly promising material.Currently,the synthesis of large-area graphene films on metal substrates via chemical vapor deposition remains the predominant approach for producing high-quality graphene.To realize the potential applications of graphene,it is essential to transfer graphene films to target substrates in a manner that is non-destructive,clean,and efficient,as this significantly affects the performance of graphene devices.This review examines the current methods for graphene transfer from three perspectives:non-destructive transfer,clean transfer,and high-efficiency transfer.It analyzes and compares the advancements and limitations of various transfer techniques.Finally,the review identifies the key challenges faced by current graphene transfer methods and anticipates future developmental prospects.
文摘Through literature analysis and case study, the introduction history, variety selection (high bush, half high bush, low bush) and regional cultivation techniques of blueberry in China were summarized, and the practical effects of precision cultivation (water and fertilizer integration, wild planting) and under-forest economic model (forest-blueberry-fungus system, ecological tourism) were evaluated. It provided a technical reference for expanding the planting scale of blueberry and improving the fruit quality.
基金financially supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415 and 52205475)the Science Center for Gas Turbine Project(Nos.P2022-AB-Ⅳ-002-001 and P2023-B-Ⅳ-003-001)+4 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210295)the Superior Postdoctoral Project of Jiangsu Province(No.2022ZB215)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_0355)the Interdisciplinary Innovation Fund for Doctoral Students of Nanjing University of Aeronautics and Astronautics(KXKCXJJ202305)the Fundamental Research Funds for the Central Universities(Nos.NS2023028 and NG2024015)。
文摘Gamma titanium-aluminum intermetallic compounds(γ-TiAl)have gained considerable attentions in the aerospace industry due to their exceptional thermal resilience and comprehensive attributes,making them a prime example of lightweight and advanced materials.To address the frequent occurrence of burns and severe tool deterioration during the process of high-efficiency deep grinding(HEDG)onγ-TiAl alloys,ultrasonic vibration-assisted high-efficiency deep grinding(UVHEDG)has been emerged.Results indicate that in UVHEDG,the grinding temperature is on average 15.4%lower than HEDG due to the employment of ultrasonic vibrations,enhancing coolant penetration into the grinding area and thus reducing heat generation.Besides,UVHEDG possesses superior performance in terms of grinding forces compared to HEDG.As the material removal volume(MRV)increases,the tangential grinding force(F_(t))and normal grinding force(F_(n))of UVHEDG increase but to a lesser extent than in HEDG,with an average reduction of16.25%and 14.7%,respectively.UVHEDG primarily experiences microfracture of grains,whereas HEDG undergoes large-scale wear later in the process due to increased grinding forces.The surface roughness(R_(a))characteristics of UVHEDG are superior,with the average value of R_(a)decreasing by 46.5%compared to HEDG as MRV increases.The surface morphology in UVHEDG exhibits enhanced smoothness and a shallower layer of plastic deformation.Grinding chips generated by UVHEDG show a more shear-like shape,with the applied influence of ultrasonic vibration on chip morphology,thereby impacting material removal behaviors.These aforementioned findings contribute to enhanced machining efficiency and product quality ofγ-TiAl alloys after employing ultrasonic vibrations into HEDG.
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support from the National Natural Science Foundation of China(Grant Nos.52025028,52332008,52372214,and U22A20137)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Metal halide perovskite solar cells(PSCs)are one of the most promising photovoltaic devices.Over time,many strategies have been adopted to improve PSC efficiency,and the certified efficiency has reached 26.1%.However,only a few research groups have fabricated PSCs with an efficiency of>25%,indicating that achieving this efficiency remains uncommon.To develop the PSC industry,outstanding talent must be reserved with the latest technologies.Herein,we summarize the recent developments in high-efficiency PSCs(>25%)and highlight their effective strategies in crystal regulation,interface passivation,and component layer structural design.Finally,we propose perspectives based on current research to further enhance the efficiency and promote the commercialization process of PSCs.
基金supported by the National Natural Science Foundation of China(Nos.52025132,22005255,21975209,21621091,22021001,T2241022)the National Science Foundation of Fujian Province of China(No.2022J02059)+2 种基金the Fundamental Research Funds for the Central Universities of China(No.20720220085)the 111 Project(Nos.B17027,B16029)the Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(No.RD2022070601),the New Cornerstone Science Foundation through the XPLORER PRIZE.
文摘The isolation of circulating tumor cells(CTCs)from complex biological samples is of paramount signifi-cance for advancing cancer diagnosis,prognosis,and treatment.However,the low concentration of CTCs and nonspecific adhesion of white blood cells(WBCs)present challenges that hinder the efficiency and purity of captured CTCs.Microfluidic-based strategies utilize precise fluid control at the micron level to incorporate specific micro/nanostructures or recognition molecules,enabling effective CTCs separation.Moreover,by employing surface modification designs that exhibit exceptional anti-adhesion properties against WBCs,the purity of isolated CTCs can be further enhanced.This review offers an in-depth explo-ration of recent advancements,challenges,and opportunities associated with microfluidic-based CTCs iso-lation from biological samples.Firstly,we will comprehensively introduce the microfluidic-based strate-gies for achieving high-efficiency CTCs isolation,which includes the morphological design of microchan-nels for physical force-based CTCs isolation and the specific modification of microchannel surfaces for affinity-based CTCs isolation.Subsequently,a review of recent research advances in microfluidic-based high-purity CTCs isolation is presented,focusing on strategies that decrease the nonspecific adhesion of WBCs through surface micro-/nanostructure construction or chemical and biological modification.Finally,we will summarize the article by providing the prospective opportunities and challenges for the future development of microfluidic-based CTCs isolation.
基金supported by the financial aid from National Science and Technology Major Project of China(No.2021YFB3500700)National Natural Science Foundation of China(Nos.22020102003,22025506 and 22271274)Program of Science and Technology Development Plan of Jilin Province of China(Nos.20230101035JC and 20230101022JC)。
文摘The preparation of Pd-based catalysts with rich electrons and a high atom dispersion rate is of great significance for improving the reactivity of cross-coupling reactions,which is a powerful tool for pharmaceutical and fine chemical synthesis.Here,we report a PdNi single-atom alloy(SAA)catalyst in which isolated Pd single atoms are anchored onto the surface of Ni nanoparticles(NPs)applied for Suzuki coupling reactions and Heck coupling reactions.The 0.1%PdNi SAA exhibits extraordinary catalytic activity(reaction rate:17,032.25 mmol h^(-1)gPd^(-1))toward the Suzuki cross-coupling reaction between 4-bromoanisole and phenylboronic acid at 80℃for 1 h.The excellent activity is supposed to attribute to the 100 percent utilization rate of Pd atoms and the highly stable surface zero-valance Pd atoms,which provides abundant sites and electrons for the adsorption and fracture of the C-X(X=Cl,Br,I)bond.Moreover,our work demonstrates the excellent application prospect of SAAs for cross-coupling reactions.
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.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDA08040101)the Hundred Talents Program of Chinese Academy of Sciences to Q.Y. Bu+1 种基金the Natural Science Foundation of Heilongjiang (No.ZD2015005)Excellent Academic Leaders of Harbin (No.RC2014XK002003)
文摘Rice is a staple food for more than half of the human population.It has been estimated that by 2030,40%more rice needs to be produced in order to meet the growing demand（Khush,2005）.One of the strategies to improve rice productivity is to enlarge rice growth areas, such as the northward expansion of the growth region in Heilongjiang Province, the northernmost region of China （Li et al., 2015）. However, the northward cultivation is accompanied with daylength extension and temperature decrease, which are unfavor- able for rice, a tropical short-day plant, to complete flowering and seed setting. Thus, the need for early-maturing rice cultivars with extremely low photoperiod sensitivity is urgent.
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 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.
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(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.
基金financially funded by the National Natural Science Foundation of China(No.31701678)the Key Project of Shanghai Agriculture Prosperity through Science and Technology(No.2019-02-08-00-15-F01147)+3 种基金the project of Shanghai Science and Technology Committee(No.19391901600)the Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.20JC1415300)the State Key Laborato ry of Transducer Technology of China(No.SKT1904)the Research Support Project number(No.RSP-2020/155),King Saud University,Riyadh,Saudi Arabia。
文摘Acephate pesticide contamination in agricultural production has caused serious human health problems.Metal oxide semiconductor(MOS)gas sensor can be used as a portable and promising alternative tool for efficiently detection of acephate.In this study,hierarchical assembled SnO_(2)nanosphere,SnO_(2)hollow nanosphere and SnO_2 nanoflower were synthesized respectively as high efficiency sensing materials to build rapid and selective acephate pesticide residues sensors.The morphologies of different SnO_(2)3 D nanostructures were characterized by various material characterization technology.The sensitive performance test results of the 3 D SnO_(2)nanomaterials towards acephate show that hollow nanosphere SnO_(2)based sensor displayed preferable sensitivity,selectivity,and rapid response(9 s)properties toward acephate at the optimal working temperature(300℃).This SnO_(2)hollow nanosphere based gas sensor represents a useful tool for simple and highly effective monitoring of acephate pesticide residues in food and environment.According to the characterization results,particularly Brunauer-Emmett-Teller(BET)and Ultraviolet-Visible Spectroscopy(UV-vis),the obvious and fast response can be attributed to the mesoporous hollow nanosphere structure and appropriate band gap of SnO_2 hollow nanosphere.
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 No 2013CBA01502the National Natural Science Foundation of China under Grant Nos 11575011 and 11535001+1 种基金the National Grand Instrument Project under Grant No2012YQ030142the UK EPSRC under Grant Nos EP/G054950/1,EP/G056803/1,EP/G055165/1 and EP/M022463/1
文摘An improved indirect scheme for laser positron generation is proposed. The positron yields in high-ZZ metal targets irradiated by laser produced electrons from near-critical density plasmas and underdense plasma are investigated numerically. It is found that the positron yield is mainly affected by the number of electrons of energies up to several hundreds of MeV. Using near-critical density targets for electron acceleration, the number of high energy electrons can be increased dramatically. Through start-to-end simulations, it is shown that up to 6.78×10106.78×1010 positrons can be generated with state-of-the-art Joule-class femtosecond laser systems.
