A pyridine-anchor co-adsorbent of N,N＇-bis（（pyridin-2-yl）（methyl） methylene）-o-phenylenediamine（named BPPI） is prepared and employed as co-adsorbent in dye-sensitized solar cells（DSSCs）. The prepared co-ads...A pyridine-anchor co-adsorbent of N,N＇-bis（（pyridin-2-yl）（methyl） methylene）-o-phenylenediamine（named BPPI） is prepared and employed as co-adsorbent in dye-sensitized solar cells（DSSCs）. The prepared co-adsorbent could overcome the deficiency of N719 absorption in the low wavelength region of visible spectrum, offset competitive visible light absorption of I_3^-, enhance the spectral responses of the co-adsorbed TiO_2 film in region from 300 nm to 750 nm, suppress charge recombination, prolong electron lifetime, and decrease the total resistance of DSSCs. The optimized cell device co-sensitized by BPPI/N719 dye gives a short circuit current density of 12.98 m A cm^（-2）, an open circuit voltage of 0.73 V,and a fill factor of 0.66 corresponding to an overall conversion efficiency of 6.22% under standard global AM 1.5 solar irradiation, which is much higher than that of device solely sensitized by N719（5.29%）under the same conditions. Mechanistic investigations are carried out by various spectral and electrochemical characterizations.展开更多
Owing to its thickness-modulated direct energy band gap, relatively strong light–matter interaction, and unique nonlinear optical response at a long wavelength, few-layer black phosphorus, or phosphorene, becomes ver...Owing to its thickness-modulated direct energy band gap, relatively strong light–matter interaction, and unique nonlinear optical response at a long wavelength, few-layer black phosphorus, or phosphorene, becomes very attractive in ultrafast photonics applications. Herein, we synthesized a graphene/phosphorene nano-heterojunction using a liquid phase-stripping method. Tiny lattice distortions in graphene and phosphorene suggest the formation of a nano-heterojunction between graphene and phosphorene nanosheets. In addition, we systematically investigate their nonlinear optical responses at different wavelength regimes. Our experiments indicate that the combined advantages of ultrafast relaxation, broadband response in graphene, and the strong light–matter interaction in phosphorene can be combined together by nano-heterojunction. We have further fabricated two-dimensional(2D) nano-heterojunction based optical saturable absorbers and integrated them into an erbium-doped fiber laser to demonstrate the generation of a stable ultrashort pulse down to 148 fs. Our results indicate that a graphene/phosphorene nano-heterojunction can operate as a promising saturable absorber for ultrafast laser systems with ultrahigh pulse energy and ultranarrow pulse duration. We believe this work opens up a new approach to designing 2D heterointerfaces for applications in ultrafast photonics and other research.The fabrication of a 2D nano-heterojunction assembled from stacking different 2D materials, via this facile and scalable growth approach, paves the way for the formation and tuning of new 2D materials with desirable photonic properties and applications.展开更多
Ni-rich cathode material is one of the most promising materials for Li-ion batteries in electric vehicles.However,fading capacity,poor cyclic stability and high p H value are still major challenges,which suppress its ...Ni-rich cathode material is one of the most promising materials for Li-ion batteries in electric vehicles.However,fading capacity,poor cyclic stability and high p H value are still major challenges,which suppress its practical application.In this study,spherical LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)powders with 0.4 wt%TiO_(2)coating layer were prepared by impregnation-hydrolysis method.Scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD)results show that TiO_(2)is uniformly coated on the surface of LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particle and slightly embedded into LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particles.After 100 cycles at 2.0 C,0.4 wt%TiO_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode delivers much higher discharge capacity retention(77.0%)than the pristine LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode(63.3%).The excellent cycling performance of 0.4 wt%Ti O_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode at a high discharge ratio is due to a TiO_(2)coating layer which can effectively reduce the direct contact between cathode material and electrolyte,suppress the oxidation of electrolyte,improve electrical conductivity of the electrode and increase the stability of the structure.展开更多
Aiming at the problem of large fading noise in Rayleigh Brillouin optical time domain analysis system, a wavelength scanning technique is proposed to enhance the performance of the temperature sensing system. The prin...Aiming at the problem of large fading noise in Rayleigh Brillouin optical time domain analysis system, a wavelength scanning technique is proposed to enhance the performance of the temperature sensing system. The principle of the proposed technique to reduce the fading noise is introduced based on the analysis of Rayleigh Brillouin optical time domain analysis system. The experimental results show that the signal-to-noise ratio(SNR) at the end of optical fiber with length of 50 m after 17 times wavelength scanning is 5.21 d B higher than that with single wavelength, the Brillouin frequency shift(BFS) on the heated fiber with length of 70 m inserted at the center of sensing fiber can be accurately measured as 0.19 MHz, which is equivalent to a measurement accuracy of 0.19 °C. It indicates that the proposed technique can realize high-accuracy temperature measurement and has huge potential in the field of long-distance and high-accuracy sensing.展开更多
Ag3PO4 microcrystals with highly enhanced visible light photocatalytic activity are prepared by a facile and simple solid state reaction at room temperature. The composition, morphology and optical properties of the a...Ag3PO4 microcrystals with highly enhanced visible light photocatalytic activity are prepared by a facile and simple solid state reaction at room temperature. The composition, morphology and optical properties of the asprepared Ag3PO4 microcrystMs are characterized by x-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectra. The photocatalytie properties of Ag3PO4 are investigated by the degradation of both methylene blue and methyl orange dyes under visible light irradiation. The as-prepared Ag3PO4 microcrystals possess high photocatalytic oxygen production with the rate of 673μmolh-1g-1. Moreover, the as-prepared Ag3PO4 microcrystals show an enhanced photoelectrochemistry performance under irradiation of visible light.展开更多
Background:Despite the wide use of compression garments to enhance athletic running performance,evidence supporting improvements has not been conclusive.This updated systematic review and meta-analysis of randomized c...Background:Despite the wide use of compression garments to enhance athletic running performance,evidence supporting improvements has not been conclusive.This updated systematic review and meta-analysis of randomized controlled trials(RCTs)compared the effects of compression garment wearing with those of non-compression garment wearing(controls)during running on improving running performance.Methods:A comprehensive search was conducted in the electronic databases(Web of Science,EBSCOhost,PubMed,Embase,Scopus,and Cochrane)for RCTs comparing running performance between runners wearing compression garments and controls during running,from inception to September 2024.Independent reviewers screened studies,extracted data,appraised risk of bias(RoB 2)and certainty of evidence(Grading of Recommendations Assessments,Development and Evaluation(GRADE)).Primary outcomes were race time and time to exhaustion.Secondary outcomes covered running speed and race pace,submaximal oxygen uptake,tissue oxygenation,and soft tissue vibration.Randomeffects meta-analyses were conducted to generate pooled estimates,expressed in standardized mean difference(SMD).Subgroup differences of garment,race type,and contact surface were tested in moderator analyses.Results:The search yielded 51 eligible studies comprising 899 participants,of which 33 studies were available for meta-analysis of primary outcomes.Runners wearing compression garments during running showed no significant improvement in race time(SMD=-0.07,95%CI:-0.22 to 0.09;p=0.40)or time to exhaustion(SMD=0.04,95%CI:-0.20 to 0.29;p=0.72).Moderator analyses indicated no effects from garment type,race type,or surface.Secondary outcomes also showed no performance benefits,although compression garments significantly reduced soft tissue vibration(SMD=-0.43,95%CI:-0.70 to-0.15;p<0.01).Certainty of evidence was rated low to very low.Conclusion:Data synthesis of current RCTs offers no updated evidence favoring the support of wearing compression garments during running as a viable strategy for improving running and endurance performance among runners of varying performance levels and types of running races.展开更多
Thermoelectric air conditioning systems based on the Peltier effect had two modes:heating and cooling.In this work,the proposed design provides continuous improvement in COP from the first minute of operation.In cooli...Thermoelectric air conditioning systems based on the Peltier effect had two modes:heating and cooling.In this work,the proposed design provides continuous improvement in COP from the first minute of operation.In cooling mode,the coefficient of performance(COP)was 1.176 due to the techniques used in this device,and it increased to 1.24 in the last minute of operation.Concerning the steady-state scenario,from the first minute,the Qc was larger than the W for the entire duration of the operation.The output temperature reaches 18.97℃ ,and the temperature on the cold side reaches 4.96℃ in the fifteen minutes of operation.The cooling mood was checked in Iraq/Baghdad in October with a temperature of 31℃ .Furthermore,the heating mode was checked in December with a temperature of 22℃ .Due to the size of the component on the cold side being small compared with the size of the component on the heat side,it reached a steady state in 13 min.This means the COP in heating mode reached 1.01 in 14 min.Furthermore,due to the presence of a thermal insulator made inside the device to separate the cold side and the hot side,the difference in temperature causes a noticeable little ascent.This is why the COP increased because it kept the degree differences low.Performance enhancements were achieved by optimizing the behavior of thermoelectric materials.The device contains 3 Peltier elements,a water-cooled system with one Peltier,a heat sink,and a fan.The design of the dehumidification system addresses the humidity issue commonly associated with thermoelectric air conditioners.In this context,the results indicate that the humidity rates had decreased and the cooling rate had increased with these innovative techniques,and thus,excellent performance can be achieved even if the Seebeck coefficient is not at its highest based on the condition of providing the Peltier elements’reliability and optimal thermal performance for various applications requiring both cooling and heating functions.The insulation plays a critical role in maintaining the efficiency of the system,reducing energy consumption,and ensuring long-term functionality.The proposed system is valuable for devices or environments that demand precise and dual thermal control with minimal energy wastage.展开更多
Sensors play an important role in information perception during the age of intelligence,particularly in areas such as environmental monitoring and human perception.To meet the huge demands for information acquisition ...Sensors play an important role in information perception during the age of intelligence,particularly in areas such as environmental monitoring and human perception.To meet the huge demands for information acquisition in the whole society,the development of elaborated sensor structures using patterned manufacturing technology is important to improve the performance of sensors.Creating patterned structures can enhance the interaction between the sensitive material and target matter,increase the contact area between the sensor and the target matter,amplify the effect of target matter on the sensor structure,and enhance the density of information sensing by building arrays.This review presents a comprehensive overview of patterned micro-nanostructure manufacturing techniques for performance enhancement of flexible sensors,including printing,exposure lithography,mould method,soft lithography,nanoimprinting lithography,and laser direct writing technology.Meanwhile,it introduces the evaluation methods of flexible sensor performance and discusses how patterned structures influence this performance.Finally,some practical application examples of patterned manufacturing techniques are introduced according to different types of flexible sensors.This review also summarises and provides an outlook on the role of these techniques in enhancing sensor performance offering valuable insights for future developments in the patterned manufacturing of flexible sensors.展开更多
Layered alkali-metal titanate materials are considered as attractive anodes for sodium ion batteries due to their favorable safety and low cost.However,their practical implementation faces major challenges of low elec...Layered alkali-metal titanate materials are considered as attractive anodes for sodium ion batteries due to their favorable safety and low cost.However,their practical implementation faces major challenges of low electronic conductivity and inevitable volume variation during Na^(+)intercalation and de-intercalation,which are generally difficult to conquer by a single modification method.Herein,a synergistic ally enhancing strategy to promote the electrochemical performance of Na_(2)Ti_(2)O_(5)nanowire array anode via simultaneous hydrogenation and carbon coating is developed.Hydrogenation leads to partially reduced titanium;together with conductive carbon layer,it endows Na_(2)Ti_(2)O_(5)with fast electron transport and structural stability.The resulting H-Na_(2)Ti_(2)O_(5)@C anode exhibits enhanced rate capability(8.0C,165 mAh·g^(-1))and stable cycle performance up to 1000 times in sodium-ion half-cells(the capacity of H-Na_(2)Ti_(2)O_(5)without carbon fades drastically after only 100 cycles).In addition,a newcoupling full cell is further designed with graphene hybridized high-voltage Na_(3)(VO_(0.5))_(2)(PO4)_(2)F_(2)as cathode,capable of delivering a high specific energy density of 212.1 Wh·kg^(-1)(based on the mass of both anode and cathode)and good rate and cycling stability.This work may offer inspiration for synergistic optimization of electrode materials for advanced electrochemical energy storage devices.展开更多
Introduction of asymmetric units into conjugated polymers is an important strategy to regulate the photophysical and electronic properties of polymers,as asymmetric units can not only regulate solubility and energy le...Introduction of asymmetric units into conjugated polymers is an important strategy to regulate the photophysical and electronic properties of polymers,as asymmetric units can not only regulate solubility and energy levels,but also molecular stacking and orientation,thus giving much higher optoelectronic properties.However,very few studies have been reported in this field.The semiconducting properties of conjugated polymers could be regulated through regioregularity adjustment.Here,we took the asymmetric thiophene/pyridine side group DPP as core and developed the regioregular monomer T-Py-DPP through three steps:alkyl chain introduction,tin monomer coupling and NBS double bromination.The T-Py-DPP monomer was polymerized into reg-PPy TDPP-2FBT with a head-to-head structure.The regioregularity of T-Py-DPP unit endowed reg-PPy TDPP-2FBT with backbone planarity,self-assembly orientation,network-like morphology and high crystallinity in films,thus the superior bipolar transport properties.The highest hole and electron mobilities of reg-PPy TDPP-2FBT were 0.93 and 0.57 cm^(2)·V^(-1)·s^(-1),respectively,with 40%improvement relative to the regiorandom polymer.展开更多
In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Comp...In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Compared to the commercial polypropylene(PP) separator,the sponge-like PSA/SiO_2 composite possesses better physical and electrochemical properties,such as higher porosity,ionic conductivity,thermal stability and flame retarding ability.The LiCoO_2/Li half-cells using the sponge-like composite separator demonstrate superior rate capability and cyclability over those using the commercial PP separator.Moreover,the sponge-like composite separator can ensure the normal operation of LiCoO_2/Li half-cell at an extremely high temperature of 90 °C,while the commercial PP separator cannot.All these encouraging results suggest that this phase inversion based sponge-like PSA/SiO_2 composite separator is really a promising separator for high performance LIBs.展开更多
The present study performed a numerical investigation to explore the performance enhancement of a co-flow jet(CFJ)airfoil with simple high-lift device configuration,with a specific goal to examine the feasibility and ...The present study performed a numerical investigation to explore the performance enhancement of a co-flow jet(CFJ)airfoil with simple high-lift device configuration,with a specific goal to examine the feasibility and capability of the proposed configuration for low-speed take-off and landing.Computations have been accomplished by an in-house-programmed Reynoldsaveraged Navier-Stokes solver enclosed by k-ωshear stress transport turbulence model.Three crucial geometric parameters,viz.,injection slot location,suction slot location and its angle were selected for the sake of revealing their effects on aerodynamic lift,drag,power consumption and equivalent lift-to-drag ratio.Results show that using simple high-lift devices on CFJ airfoil can significantly augment the aerodynamic associated lift and efficiency which evidences the feasibility of CFJ for short take-off and landing with small angle of attack.The injection and suction slot locations are more influential with respect to the aerodynamic performance of CFJ airfoil compared with the suction slot angle.The injection location is preferable to be located in the downstream of the pressure suction peak on leading edge to reduce the power expenditure of the pumping system for a relative higher equivalent lift-to-drag ratio.Another concluded criterion is that the suction slot should be oriented on the trailing edge flap for achieving more aerodynamic gain,meanwhile,carefully selecting this location is crucial in determining the aerodynamic enhancement of CFJ airfoil with deflected flaps.展开更多
Electrically controlled rotor （ECR） system has the potential to enhance the rotor perfor- mance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enha...Electrically controlled rotor （ECR） system has the potential to enhance the rotor perfor- mance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor performance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3% rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.展开更多
In this article,we review the recent progress and our research activity on the synthesis of inorganic shell nanostructures to enhance the catalytic performance and stability of metal nanoparticles in catalytic applica...In this article,we review the recent progress and our research activity on the synthesis of inorganic shell nanostructures to enhance the catalytic performance and stability of metal nanoparticles in catalytic applications.First,we introduce general synthetic strategies for the fabrication of inorganic nanoscale shell layers,including template-assisted sol-gel coating,hydrothermal(or solvothermal)synthesis and the self-templating process.We also discuss recent examples of metal nanoparticles(NPs)with nanoscale shell layers,namely core-shell,yolk-shell and multiple NPs-embedded nanoscale shell.We then discuss the performance and stability of metal particles in practical catalytic applications.Finally,we conclude with a summary and perspective on the further progress of inorganic nanostructure with nanoscale shell layers for catalytic applications.展开更多
Purpose： To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods： A total of 17 published studies, two of which provided two samples, were located. Accepted me...Purpose： To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods： A total of 17 published studies, two of which provided two samples, were located. Accepted meta-analytic procedures were used with Hedges g as the effect size metric. From the 17 studies, 73 effect sizes were calculated.Results： Results based on a random effects model indicated that the performance goal contrast had the largest facilitative impact on performance followed by the mastery and performance approach goals. Both of the avoidance goals performance and mastery had small non-significant and detrimental effects on performance. The homogeneity statistics revealed significant heterogeneity for the approach and avoidance performance goals. Categorical moderator variables were examined for study sex composition（male, female, or mixed）, mean age of sample（〈18 years or 18 years）, study setting（lab or naturalistic）, and nature of performance variable（objective or subjective）.Conclusion： The performance goal contrast holds value for sport performance research. Contrary to approach-avoidance predictions, the mastery-approach goal and performance effect size was significant and of equal magnitude as the performance approach goal and performance effect size. Thus, future research should closely test the efficacy of both the mastery- and performance contrasts in impacting performance of sport tasks. Last, the significant effect sizes reported in this review are in stark contrast to contemporary meta-analytic findings in education.Differences in the approach-avoidance goals in sport and education relative to performance should be researched further.展开更多
In the present study,the insulation mechanism of building walls during the summer days and nights is investigated with a realistic approach to enhance their performance.A fiber layer,as a porous medium with air gaps,i...In the present study,the insulation mechanism of building walls during the summer days and nights is investigated with a realistic approach to enhance their performance.A fiber layer,as a porous medium with air gaps,is used along the wall layers to decrease the energy loss.Meanwhile,the radiation heat flux variation during five days in a row has been considered for each side of the building,and it is tried to reach the optimum values for geometrical factors and find suitable insulation for each side of the building.A lattice Boltzmann method(LBM) based code is developed to simulate the actual chain of the heat transfer which consists of radiation,conduction,forced and natural convection combination within wall layers including fiber porous insulation.The results indicate that for the current insulation model,the effect of natural convection on the heat transfer is not negligible and the existence of the porous layer has caused a positive impact on the heat loss reduction by decreasing the circulation speed.Also,by using the optimum location and thickness for the insulation layer,it is showed that each side of the building has different rates of energy loss during a day,and for the appropriate insulation,they need to be evaluated separately.展开更多
The seismic performance of bridges depends on the ductile behavior of its column, as the deck and other substructural components except pile foundations are normally designed to be elastic to facilitate bridge retrofi...The seismic performance of bridges depends on the ductile behavior of its column, as the deck and other substructural components except pile foundations are normally designed to be elastic to facilitate bridge retrofitting. Codes such as AASHTO, Caltrans, IRC： 112 etc. give guidelines for the seismic performance enhancement of columns through ductile detailing. In the present study, a methodology for the seismic performance enhancement of bridges is discussed by using a ＂Parameter-Based Influence Factor＂ （PIF） developed from factorial analysis. The parameters considered in the factorial analysis are： percentage of longitudinal reinforcement （Pt）, compressive strength of concrete （f＇c）, yield strength of steel （fy）, spacing of lateral ties （5） and column height （/4）. The influence of each parameter and their combination on the limit states considered is estimated. Pushover analysis is used to evaluate the capacity of columns, considering shear failure criteria. A total of 243 （35 combinations） analysis results are compiled to develop ＇PIF＇ used in the performance enhancement process. The study also encompasses other sub-objectives such as evaluating the discrepancies in using the Importance Factor （/） in designing bridges of varied functional importance; and estimating the aspect ratio and slenderness ratio values of bridge columns for its initial sizing.展开更多
The concept of combining metallic honeycomb with folded thin metallic sheets （corrugation） to construct a novel core type for lightweight sandwich structures is proposed. The honeycomb-corrugation hybrid core is man...The concept of combining metallic honeycomb with folded thin metallic sheets （corrugation） to construct a novel core type for lightweight sandwich structures is proposed. The honeycomb-corrugation hybrid core is manufactured by filling the interstices of aluminum corrugations with precision-cut trapezoidal aluminum honeycomb blocks, bonded together using epoxy glue. The performance of such hybrid-cored sandwich panels subjected to out-of-plane compression, transverse shear, and three-point bending is investigated, both experimentally and numerically. The strength and energy absorption of the sandwich are dramatically enhanced, compared to those of a sandwich with either empty corrugation or honeycomb core. The enhancement is induced by the beneficial interaction effects of honeycomb blocks and folded panels on improved buckling resistance as well as altered crushing modes at large plastic deformation. The present approach provides an effective method to further improve the mechanical properties of conventional honeycomb-cored sandwich constructions with low relative densities.展开更多
In order to increase the efficiency of solar collector, a methodology is proposed based on the analysis of its influencing factors, such as thermal conductivity of filled layer, structure forms of filled layer and hea...In order to increase the efficiency of solar collector, a methodology is proposed based on the analysis of its influencing factors, such as thermal conductivity of filled layer, structure forms of filled layer and heat loss coefficient. The results of analysis show that the heat transfer between pipes in evacuated tube is one of the most important factors, which can lead to the decrease of the outlet temperature of working fluid. In order to eliminate the negative influence of the heat transfer between pipes, the hollow filled-type evacuated tube with U-tube(HUFET) was developed, and the heat transfer characteristics of HUFET were analyzed by theoretical and experimental studies. The results show that the thermal resistances decrease with the increase of the thermal conductivity of filled layer. When the thermal conductivity is over 10 W/(m·K), the change of thermal resistances is very little.Furthermore, the larger the thermal conductivity of filled layer, the less the rate of the energy transfer between the two pipes to the total energy transfer, which is between the absorber tube and the working fluid. There is a little difference between the efficiencies of HUFET and UFET, with the efficiency of HUFET 2.4% higher than that of UFET. Meanwhile, the validation of the model developed was confirmed by the experiment.展开更多
The analytic method, part of the epistemonic method, provides us with a way to cope with perplexed cases, without even referring to the world out there. We are able to predict all possible variations of consent, and g...The analytic method, part of the epistemonic method, provides us with a way to cope with perplexed cases, without even referring to the world out there. We are able to predict all possible variations of consent, and go on forming minimum logical quadripoles, 8-poles, 16-poles, etc., before even trying to make any connection to the world. This way, there are two major outcomes： All possible scenarios are predicted, and, because of that, our ＂logical generator＂ produces scenarios we couldn＇t even think of. Consent is, therefore, neither binary （existence or absence）, nor just a continuum from existence to absence, but a cladistic tree stemming from the basic quadripole ＂existence of consent/not existence of consent/absence of consent/not absence of consent.＂ The complexity increases rapidly when other terms are included; try： ＂existence of informed consent＂ or ＂existence of unintentional consent.＂ More levels develop as we examine relevant terms, such as ＂exposure,＂ ＂protection,＂ or ＂consumption.＂ In our case-study, we shall examine how different aspects of consent are expressed regarding the issue of performance enhancement and consider some implications for the notion of expertise within an SEA （Science of Exceptional Achievement） context. Many different terms may describe the most common situations, namely, ＂uniformed consent,＂ ＂unintentional consent,＂ ＂non-intentional consent,＂ ＂not absence of consent,＂ and also, ＂unintentional exposure,＂ ＂intentional non-protection,＂ and so on. In Greek language, the possible variations are even more （there are two kinds of negation in Greek）. All the aforementioned terms have different ethical consequences. We shall also examine whether doping is an inherent part of expertise attainment.展开更多
基金supported by National Natural Science Foundation of China (Nos. 21171044 and 21371040)the National Key Basic Research Program of China (973 Program, No. 2013CB632900)+1 种基金the Fundamental Research Funds for the Central Universities (No. HIT. IBRSEM. A201409)Program for Innovation Research of Science in Harbin Institute of Technology (PIRS of HIT Nos. A201418, A201416 and B201414)
文摘A pyridine-anchor co-adsorbent of N,N＇-bis（（pyridin-2-yl）（methyl） methylene）-o-phenylenediamine（named BPPI） is prepared and employed as co-adsorbent in dye-sensitized solar cells（DSSCs）. The prepared co-adsorbent could overcome the deficiency of N719 absorption in the low wavelength region of visible spectrum, offset competitive visible light absorption of I_3^-, enhance the spectral responses of the co-adsorbed TiO_2 film in region from 300 nm to 750 nm, suppress charge recombination, prolong electron lifetime, and decrease the total resistance of DSSCs. The optimized cell device co-sensitized by BPPI/N719 dye gives a short circuit current density of 12.98 m A cm^（-2）, an open circuit voltage of 0.73 V,and a fill factor of 0.66 corresponding to an overall conversion efficiency of 6.22% under standard global AM 1.5 solar irradiation, which is much higher than that of device solely sensitized by N719（5.29%）under the same conditions. Mechanistic investigations are carried out by various spectral and electrochemical characterizations.
基金National Natural Science Foundation of China(NSFC)(61435010,61575089)Shenzhen-Hong Kong Innovation Cooperation Project(SGLH20150205162842428)+3 种基金Science and Technology Innovation Commission of Shenzhen JCYJ20150625103619275,JCYJ20170302153540973,JCYJ20170412111625378,KQTD2015032416270385)Science and Technology Planning Project of Guangdong Province(2016B050501005)Educational Commission ofGuangdong Province 2016KCXTD006)Student Innovation Development Fund of Shenzhen University(PIDFPZR2017002)
文摘Owing to its thickness-modulated direct energy band gap, relatively strong light–matter interaction, and unique nonlinear optical response at a long wavelength, few-layer black phosphorus, or phosphorene, becomes very attractive in ultrafast photonics applications. Herein, we synthesized a graphene/phosphorene nano-heterojunction using a liquid phase-stripping method. Tiny lattice distortions in graphene and phosphorene suggest the formation of a nano-heterojunction between graphene and phosphorene nanosheets. In addition, we systematically investigate their nonlinear optical responses at different wavelength regimes. Our experiments indicate that the combined advantages of ultrafast relaxation, broadband response in graphene, and the strong light–matter interaction in phosphorene can be combined together by nano-heterojunction. We have further fabricated two-dimensional(2D) nano-heterojunction based optical saturable absorbers and integrated them into an erbium-doped fiber laser to demonstrate the generation of a stable ultrashort pulse down to 148 fs. Our results indicate that a graphene/phosphorene nano-heterojunction can operate as a promising saturable absorber for ultrafast laser systems with ultrahigh pulse energy and ultranarrow pulse duration. We believe this work opens up a new approach to designing 2D heterointerfaces for applications in ultrafast photonics and other research.The fabrication of a 2D nano-heterojunction assembled from stacking different 2D materials, via this facile and scalable growth approach, paves the way for the formation and tuning of new 2D materials with desirable photonic properties and applications.
基金the National Natural Science Foundation of China(No.51701173)。
文摘Ni-rich cathode material is one of the most promising materials for Li-ion batteries in electric vehicles.However,fading capacity,poor cyclic stability and high p H value are still major challenges,which suppress its practical application.In this study,spherical LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)powders with 0.4 wt%TiO_(2)coating layer were prepared by impregnation-hydrolysis method.Scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD)results show that TiO_(2)is uniformly coated on the surface of LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particle and slightly embedded into LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)particles.After 100 cycles at 2.0 C,0.4 wt%TiO_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode delivers much higher discharge capacity retention(77.0%)than the pristine LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode(63.3%).The excellent cycling performance of 0.4 wt%Ti O_(2)-coated LiNi_(0.)9Co_(0.08)Al_(0.02)O_(2)electrode at a high discharge ratio is due to a TiO_(2)coating layer which can effectively reduce the direct contact between cathode material and electrolyte,suppress the oxidation of electrolyte,improve electrical conductivity of the electrode and increase the stability of the structure.
基金supported by the National Natural Science Foundation of China(No.61377088)the Natural Science Foundation of Hebei Province of China(Nos.E2015502053 and F2015502059)the Fundamental Research Funds for the Central Universities(No.2016XS104)
文摘Aiming at the problem of large fading noise in Rayleigh Brillouin optical time domain analysis system, a wavelength scanning technique is proposed to enhance the performance of the temperature sensing system. The principle of the proposed technique to reduce the fading noise is introduced based on the analysis of Rayleigh Brillouin optical time domain analysis system. The experimental results show that the signal-to-noise ratio(SNR) at the end of optical fiber with length of 50 m after 17 times wavelength scanning is 5.21 d B higher than that with single wavelength, the Brillouin frequency shift(BFS) on the heated fiber with length of 70 m inserted at the center of sensing fiber can be accurately measured as 0.19 MHz, which is equivalent to a measurement accuracy of 0.19 °C. It indicates that the proposed technique can realize high-accuracy temperature measurement and has huge potential in the field of long-distance and high-accuracy sensing.
基金Supported by the Beijing Higher Education Young Elite Teacher Project under Grant No YETP1297the Fundamental Research Funds for the Central Universities under Grant No 2014MDLXYZY05+1 种基金the Undergraduate Innovative Test Program of China under Grant Nos GCCX2015110009 and BEIJ2015110024the National Natural Science Foundation of China under Grant Nos11074312 and 11374377
文摘Ag3PO4 microcrystals with highly enhanced visible light photocatalytic activity are prepared by a facile and simple solid state reaction at room temperature. The composition, morphology and optical properties of the asprepared Ag3PO4 microcrystMs are characterized by x-ray diffraction, scanning electron microscopy and UV-vis diffuse reflectance spectra. The photocatalytie properties of Ag3PO4 are investigated by the degradation of both methylene blue and methyl orange dyes under visible light irradiation. The as-prepared Ag3PO4 microcrystals possess high photocatalytic oxygen production with the rate of 673μmolh-1g-1. Moreover, the as-prepared Ag3PO4 microcrystals show an enhanced photoelectrochemistry performance under irradiation of visible light.
基金supported by the National Natural Science Foundation of China(Grant No.NSFC11932013)National Key Research and Development Program of China(Grant No.2022YFB3805800).
文摘Background:Despite the wide use of compression garments to enhance athletic running performance,evidence supporting improvements has not been conclusive.This updated systematic review and meta-analysis of randomized controlled trials(RCTs)compared the effects of compression garment wearing with those of non-compression garment wearing(controls)during running on improving running performance.Methods:A comprehensive search was conducted in the electronic databases(Web of Science,EBSCOhost,PubMed,Embase,Scopus,and Cochrane)for RCTs comparing running performance between runners wearing compression garments and controls during running,from inception to September 2024.Independent reviewers screened studies,extracted data,appraised risk of bias(RoB 2)and certainty of evidence(Grading of Recommendations Assessments,Development and Evaluation(GRADE)).Primary outcomes were race time and time to exhaustion.Secondary outcomes covered running speed and race pace,submaximal oxygen uptake,tissue oxygenation,and soft tissue vibration.Randomeffects meta-analyses were conducted to generate pooled estimates,expressed in standardized mean difference(SMD).Subgroup differences of garment,race type,and contact surface were tested in moderator analyses.Results:The search yielded 51 eligible studies comprising 899 participants,of which 33 studies were available for meta-analysis of primary outcomes.Runners wearing compression garments during running showed no significant improvement in race time(SMD=-0.07,95%CI:-0.22 to 0.09;p=0.40)or time to exhaustion(SMD=0.04,95%CI:-0.20 to 0.29;p=0.72).Moderator analyses indicated no effects from garment type,race type,or surface.Secondary outcomes also showed no performance benefits,although compression garments significantly reduced soft tissue vibration(SMD=-0.43,95%CI:-0.70 to-0.15;p<0.01).Certainty of evidence was rated low to very low.Conclusion:Data synthesis of current RCTs offers no updated evidence favoring the support of wearing compression garments during running as a viable strategy for improving running and endurance performance among runners of varying performance levels and types of running races.
文摘Thermoelectric air conditioning systems based on the Peltier effect had two modes:heating and cooling.In this work,the proposed design provides continuous improvement in COP from the first minute of operation.In cooling mode,the coefficient of performance(COP)was 1.176 due to the techniques used in this device,and it increased to 1.24 in the last minute of operation.Concerning the steady-state scenario,from the first minute,the Qc was larger than the W for the entire duration of the operation.The output temperature reaches 18.97℃ ,and the temperature on the cold side reaches 4.96℃ in the fifteen minutes of operation.The cooling mood was checked in Iraq/Baghdad in October with a temperature of 31℃ .Furthermore,the heating mode was checked in December with a temperature of 22℃ .Due to the size of the component on the cold side being small compared with the size of the component on the heat side,it reached a steady state in 13 min.This means the COP in heating mode reached 1.01 in 14 min.Furthermore,due to the presence of a thermal insulator made inside the device to separate the cold side and the hot side,the difference in temperature causes a noticeable little ascent.This is why the COP increased because it kept the degree differences low.Performance enhancements were achieved by optimizing the behavior of thermoelectric materials.The device contains 3 Peltier elements,a water-cooled system with one Peltier,a heat sink,and a fan.The design of the dehumidification system addresses the humidity issue commonly associated with thermoelectric air conditioners.In this context,the results indicate that the humidity rates had decreased and the cooling rate had increased with these innovative techniques,and thus,excellent performance can be achieved even if the Seebeck coefficient is not at its highest based on the condition of providing the Peltier elements’reliability and optimal thermal performance for various applications requiring both cooling and heating functions.The insulation plays a critical role in maintaining the efficiency of the system,reducing energy consumption,and ensuring long-term functionality.The proposed system is valuable for devices or environments that demand precise and dual thermal control with minimal energy wastage.
基金financial support from the National Key Research and Development Program of China(Grant 2024YFB3212100)National Natural Science Foundation of China(NSFC Grant Nos.62422409,62174152 and 62374159)from the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020115)。
文摘Sensors play an important role in information perception during the age of intelligence,particularly in areas such as environmental monitoring and human perception.To meet the huge demands for information acquisition in the whole society,the development of elaborated sensor structures using patterned manufacturing technology is important to improve the performance of sensors.Creating patterned structures can enhance the interaction between the sensitive material and target matter,increase the contact area between the sensor and the target matter,amplify the effect of target matter on the sensor structure,and enhance the density of information sensing by building arrays.This review presents a comprehensive overview of patterned micro-nanostructure manufacturing techniques for performance enhancement of flexible sensors,including printing,exposure lithography,mould method,soft lithography,nanoimprinting lithography,and laser direct writing technology.Meanwhile,it introduces the evaluation methods of flexible sensor performance and discusses how patterned structures influence this performance.Finally,some practical application examples of patterned manufacturing techniques are introduced according to different types of flexible sensors.This review also summarises and provides an outlook on the role of these techniques in enhancing sensor performance offering valuable insights for future developments in the patterned manufacturing of flexible sensors.
基金financially supported by the National Natural Science Foundation of China(Nos.52072136,51872104,51972257 and 52172229)the National Key R&D Program of China(No.2016YFA0202602)the Fundamental Research Funds for the Central Universities(No.WUT:2021IVA115)
文摘Layered alkali-metal titanate materials are considered as attractive anodes for sodium ion batteries due to their favorable safety and low cost.However,their practical implementation faces major challenges of low electronic conductivity and inevitable volume variation during Na^(+)intercalation and de-intercalation,which are generally difficult to conquer by a single modification method.Herein,a synergistic ally enhancing strategy to promote the electrochemical performance of Na_(2)Ti_(2)O_(5)nanowire array anode via simultaneous hydrogenation and carbon coating is developed.Hydrogenation leads to partially reduced titanium;together with conductive carbon layer,it endows Na_(2)Ti_(2)O_(5)with fast electron transport and structural stability.The resulting H-Na_(2)Ti_(2)O_(5)@C anode exhibits enhanced rate capability(8.0C,165 mAh·g^(-1))and stable cycle performance up to 1000 times in sodium-ion half-cells(the capacity of H-Na_(2)Ti_(2)O_(5)without carbon fades drastically after only 100 cycles).In addition,a newcoupling full cell is further designed with graphene hybridized high-voltage Na_(3)(VO_(0.5))_(2)(PO4)_(2)F_(2)as cathode,capable of delivering a high specific energy density of 212.1 Wh·kg^(-1)(based on the mass of both anode and cathode)and good rate and cycling stability.This work may offer inspiration for synergistic optimization of electrode materials for advanced electrochemical energy storage devices.
基金financially supported by the Ministry of Science and Technology of China(Nos.2018YFA0703200 and 2022YFB3603800)the National Natural Science Foundation of China(Nos.21875259,52233010,51725304,61890943,52103245 and 22021002)+2 种基金the CAS Project for Young Scientists in Basic Research(No.YSBR-053)the Youth Innovation Promotion Association of the Chinese Academy of Sciences,the National Program for Support of Top-notch Young Professionals,the Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202012)the Key Research Program of the Chinese Academy of Sciences(Nos.XDPB13 and 121111KYSB20200004)。
文摘Introduction of asymmetric units into conjugated polymers is an important strategy to regulate the photophysical and electronic properties of polymers,as asymmetric units can not only regulate solubility and energy levels,but also molecular stacking and orientation,thus giving much higher optoelectronic properties.However,very few studies have been reported in this field.The semiconducting properties of conjugated polymers could be regulated through regioregularity adjustment.Here,we took the asymmetric thiophene/pyridine side group DPP as core and developed the regioregular monomer T-Py-DPP through three steps:alkyl chain introduction,tin monomer coupling and NBS double bromination.The T-Py-DPP monomer was polymerized into reg-PPy TDPP-2FBT with a head-to-head structure.The regioregularity of T-Py-DPP unit endowed reg-PPy TDPP-2FBT with backbone planarity,self-assembly orientation,network-like morphology and high crystallinity in films,thus the superior bipolar transport properties.The highest hole and electron mobilities of reg-PPy TDPP-2FBT were 0.93 and 0.57 cm^(2)·V^(-1)·s^(-1),respectively,with 40%improvement relative to the regiorandom polymer.
基金Supported by the funding from "135" Projects Fund of CAS-QIBEBT Director Innovation FoundationThink-Tank Mutual Fund of Qingdao Energy Storage Industry Scientific Research+3 种基金Qingdao Key Lab of Solar Energy Utilization and Energy Storage Technologythe Strategic Priority Research Program of the Chinese Academy of Sciences(XDA09010105)National Natural Science Foundation of China(51502319)Shandong Provincial Natural Science Foundation(ZR2016BQ18)
文摘In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Compared to the commercial polypropylene(PP) separator,the sponge-like PSA/SiO_2 composite possesses better physical and electrochemical properties,such as higher porosity,ionic conductivity,thermal stability and flame retarding ability.The LiCoO_2/Li half-cells using the sponge-like composite separator demonstrate superior rate capability and cyclability over those using the commercial PP separator.Moreover,the sponge-like composite separator can ensure the normal operation of LiCoO_2/Li half-cell at an extremely high temperature of 90 °C,while the commercial PP separator cannot.All these encouraging results suggest that this phase inversion based sponge-like PSA/SiO_2 composite separator is really a promising separator for high performance LIBs.
基金supported by the National Natural Science Foundation of China(No.11672133)the Research Funds for Central Universities(No.kfjj20180104)support from Rotor Aerodynamics Key Laboratory(No.RAL20190202-2)。
文摘The present study performed a numerical investigation to explore the performance enhancement of a co-flow jet(CFJ)airfoil with simple high-lift device configuration,with a specific goal to examine the feasibility and capability of the proposed configuration for low-speed take-off and landing.Computations have been accomplished by an in-house-programmed Reynoldsaveraged Navier-Stokes solver enclosed by k-ωshear stress transport turbulence model.Three crucial geometric parameters,viz.,injection slot location,suction slot location and its angle were selected for the sake of revealing their effects on aerodynamic lift,drag,power consumption and equivalent lift-to-drag ratio.Results show that using simple high-lift devices on CFJ airfoil can significantly augment the aerodynamic associated lift and efficiency which evidences the feasibility of CFJ for short take-off and landing with small angle of attack.The injection and suction slot locations are more influential with respect to the aerodynamic performance of CFJ airfoil compared with the suction slot angle.The injection location is preferable to be located in the downstream of the pressure suction peak on leading edge to reduce the power expenditure of the pumping system for a relative higher equivalent lift-to-drag ratio.Another concluded criterion is that the suction slot should be oriented on the trailing edge flap for achieving more aerodynamic gain,meanwhile,carefully selecting this location is crucial in determining the aerodynamic enhancement of CFJ airfoil with deflected flaps.
基金supported by the National Natural Science Foundation of China (No. 51375229)
文摘Electrically controlled rotor （ECR） system has the potential to enhance the rotor perfor- mance by applying higher harmonic flap inputs. In order to explore the feasibility and effectiveness for ECR performance enhancement using closed-loop control method, firstly, an ECR rotor performance analysis model based on helicopter flight dynamic model is established, which can reflect the performance characteristics of ECR helicopter at high advance ratio. Based on the simulation platform, an active control method named adaptive T-matrix algorithm is adopted to explore the feasibility and effectiveness for ECR performance enhancement. The simulation results verify the effectiveness of this closed-loop control method. For the sample ECR helicopter, about 3% rotor power reduction is obtained with the optimum 2/rev flap inputs at the advance ratio of 0.34. And through analyzing the distributions of attack of angle and drag in rotor disk, the underlying physical essence of ECR power reduction is cleared. Furthermore, the influence of the key control parameters, including convergence factor and weighting matrix, on the effectiveness of closed-loop control for ECR performance enhancement is explored. Some useful results are summarized, which can be used to direct the future active control law design of ECR performance enhancement.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry and Energy(MOTIE,No.20174010201490)financially supported by the Korea Environment Industry&Technology Institute(KEITI)through"The Chemical Accident Prevention Technology Development Project"granted by the Korea Ministry of Environment(MOE,No.2017001960004)。
文摘In this article,we review the recent progress and our research activity on the synthesis of inorganic shell nanostructures to enhance the catalytic performance and stability of metal nanoparticles in catalytic applications.First,we introduce general synthetic strategies for the fabrication of inorganic nanoscale shell layers,including template-assisted sol-gel coating,hydrothermal(or solvothermal)synthesis and the self-templating process.We also discuss recent examples of metal nanoparticles(NPs)with nanoscale shell layers,namely core-shell,yolk-shell and multiple NPs-embedded nanoscale shell.We then discuss the performance and stability of metal particles in practical catalytic applications.Finally,we conclude with a summary and perspective on the further progress of inorganic nanostructure with nanoscale shell layers for catalytic applications.
文摘Purpose： To summarize the approach-avoidance achievement goal and performance in the sport psychology literature.Methods： A total of 17 published studies, two of which provided two samples, were located. Accepted meta-analytic procedures were used with Hedges g as the effect size metric. From the 17 studies, 73 effect sizes were calculated.Results： Results based on a random effects model indicated that the performance goal contrast had the largest facilitative impact on performance followed by the mastery and performance approach goals. Both of the avoidance goals performance and mastery had small non-significant and detrimental effects on performance. The homogeneity statistics revealed significant heterogeneity for the approach and avoidance performance goals. Categorical moderator variables were examined for study sex composition（male, female, or mixed）, mean age of sample（〈18 years or 18 years）, study setting（lab or naturalistic）, and nature of performance variable（objective or subjective）.Conclusion： The performance goal contrast holds value for sport performance research. Contrary to approach-avoidance predictions, the mastery-approach goal and performance effect size was significant and of equal magnitude as the performance approach goal and performance effect size. Thus, future research should closely test the efficacy of both the mastery- and performance contrasts in impacting performance of sport tasks. Last, the significant effect sizes reported in this review are in stark contrast to contemporary meta-analytic findings in education.Differences in the approach-avoidance goals in sport and education relative to performance should be researched further.
文摘In the present study,the insulation mechanism of building walls during the summer days and nights is investigated with a realistic approach to enhance their performance.A fiber layer,as a porous medium with air gaps,is used along the wall layers to decrease the energy loss.Meanwhile,the radiation heat flux variation during five days in a row has been considered for each side of the building,and it is tried to reach the optimum values for geometrical factors and find suitable insulation for each side of the building.A lattice Boltzmann method(LBM) based code is developed to simulate the actual chain of the heat transfer which consists of radiation,conduction,forced and natural convection combination within wall layers including fiber porous insulation.The results indicate that for the current insulation model,the effect of natural convection on the heat transfer is not negligible and the existence of the porous layer has caused a positive impact on the heat loss reduction by decreasing the circulation speed.Also,by using the optimum location and thickness for the insulation layer,it is showed that each side of the building has different rates of energy loss during a day,and for the appropriate insulation,they need to be evaluated separately.
文摘The seismic performance of bridges depends on the ductile behavior of its column, as the deck and other substructural components except pile foundations are normally designed to be elastic to facilitate bridge retrofitting. Codes such as AASHTO, Caltrans, IRC： 112 etc. give guidelines for the seismic performance enhancement of columns through ductile detailing. In the present study, a methodology for the seismic performance enhancement of bridges is discussed by using a ＂Parameter-Based Influence Factor＂ （PIF） developed from factorial analysis. The parameters considered in the factorial analysis are： percentage of longitudinal reinforcement （Pt）, compressive strength of concrete （f＇c）, yield strength of steel （fy）, spacing of lateral ties （5） and column height （/4）. The influence of each parameter and their combination on the limit states considered is estimated. Pushover analysis is used to evaluate the capacity of columns, considering shear failure criteria. A total of 243 （35 combinations） analysis results are compiled to develop ＇PIF＇ used in the performance enhancement process. The study also encompasses other sub-objectives such as evaluating the discrepancies in using the Importance Factor （/） in designing bridges of varied functional importance; and estimating the aspect ratio and slenderness ratio values of bridge columns for its initial sizing.
基金supported by the National Natural Science Foundation of China(11472208)the National 111 Project of China(B06024)
文摘The concept of combining metallic honeycomb with folded thin metallic sheets （corrugation） to construct a novel core type for lightweight sandwich structures is proposed. The honeycomb-corrugation hybrid core is manufactured by filling the interstices of aluminum corrugations with precision-cut trapezoidal aluminum honeycomb blocks, bonded together using epoxy glue. The performance of such hybrid-cored sandwich panels subjected to out-of-plane compression, transverse shear, and three-point bending is investigated, both experimentally and numerically. The strength and energy absorption of the sandwich are dramatically enhanced, compared to those of a sandwich with either empty corrugation or honeycomb core. The enhancement is induced by the beneficial interaction effects of honeycomb blocks and folded panels on improved buckling resistance as well as altered crushing modes at large plastic deformation. The present approach provides an effective method to further improve the mechanical properties of conventional honeycomb-cored sandwich constructions with low relative densities.
基金Projects(2011BAJ03B12-3,2013BAJ10B02-03) supported by the National Science and Technology Program during the 12th Five-year Plan Period,ChinaProject(51378005) supported by the National Natural Science Foundation,China+1 种基金Projects(DUT14RC(3)123,DUT14RC(3)129) supported by Fundamental Research Funds for the Dalian University of Tecnology,ChinaProject(DUT14ZD210) supported by the Fundamental Research Funds for the Central Universities of China
文摘In order to increase the efficiency of solar collector, a methodology is proposed based on the analysis of its influencing factors, such as thermal conductivity of filled layer, structure forms of filled layer and heat loss coefficient. The results of analysis show that the heat transfer between pipes in evacuated tube is one of the most important factors, which can lead to the decrease of the outlet temperature of working fluid. In order to eliminate the negative influence of the heat transfer between pipes, the hollow filled-type evacuated tube with U-tube(HUFET) was developed, and the heat transfer characteristics of HUFET were analyzed by theoretical and experimental studies. The results show that the thermal resistances decrease with the increase of the thermal conductivity of filled layer. When the thermal conductivity is over 10 W/(m·K), the change of thermal resistances is very little.Furthermore, the larger the thermal conductivity of filled layer, the less the rate of the energy transfer between the two pipes to the total energy transfer, which is between the absorber tube and the working fluid. There is a little difference between the efficiencies of HUFET and UFET, with the efficiency of HUFET 2.4% higher than that of UFET. Meanwhile, the validation of the model developed was confirmed by the experiment.
文摘The analytic method, part of the epistemonic method, provides us with a way to cope with perplexed cases, without even referring to the world out there. We are able to predict all possible variations of consent, and go on forming minimum logical quadripoles, 8-poles, 16-poles, etc., before even trying to make any connection to the world. This way, there are two major outcomes： All possible scenarios are predicted, and, because of that, our ＂logical generator＂ produces scenarios we couldn＇t even think of. Consent is, therefore, neither binary （existence or absence）, nor just a continuum from existence to absence, but a cladistic tree stemming from the basic quadripole ＂existence of consent/not existence of consent/absence of consent/not absence of consent.＂ The complexity increases rapidly when other terms are included; try： ＂existence of informed consent＂ or ＂existence of unintentional consent.＂ More levels develop as we examine relevant terms, such as ＂exposure,＂ ＂protection,＂ or ＂consumption.＂ In our case-study, we shall examine how different aspects of consent are expressed regarding the issue of performance enhancement and consider some implications for the notion of expertise within an SEA （Science of Exceptional Achievement） context. Many different terms may describe the most common situations, namely, ＂uniformed consent,＂ ＂unintentional consent,＂ ＂non-intentional consent,＂ ＂not absence of consent,＂ and also, ＂unintentional exposure,＂ ＂intentional non-protection,＂ and so on. In Greek language, the possible variations are even more （there are two kinds of negation in Greek）. All the aforementioned terms have different ethical consequences. We shall also examine whether doping is an inherent part of expertise attainment.
