Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachm...Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachment and complex fabrication process introduce surface defects,compromising device stability and efficiency.In this work,we propose a solution-phase ligand exchange(SPLE)method utilizing inorganic ligands to develop stable p-type lead sulfide(PbS)CQD inks for the first time.Various amounts of tin(Ⅱ)iodide(SnI_(2))were mixed with lead halide(PbX_(2);X=I,Br)in the ligand solution.By precisely controlling the SnI_(2)concentration,we regulate the transition of PbS QDs from n-type to p-type.PbS CQDSCs were fabricated using two different HTL approaches:one with 1,2-ethanedithiol(EDT)-passivated QDs via the LbL method(control)and another with inorganic ligand-passivated QD ink(target).The target devices achieved a higher power conversion efficiency(PCE)of 10.93%,compared to 9.83%for the control devices.This improvement is attributed to reduced interfacial defects and enhanced carrier mobility.The proposed technique offers an efficient pathway for producing stable p-type PbS CQD inks using inorganic ligands,paving the way for high-performance and flexible CQD-based optoelectronic devices.展开更多
Cookies are considered a fundamental means of web application services for authenticating various Hypertext Transfer Protocol(HTTP)requests andmaintains the states of clients’information over the Internet.HTTP cookie...Cookies are considered a fundamental means of web application services for authenticating various Hypertext Transfer Protocol(HTTP)requests andmaintains the states of clients’information over the Internet.HTTP cookies are exploited to carry client patterns observed by a website.These client patterns facilitate the particular client’s future visit to the corresponding website.However,security and privacy are the primary concerns owing to the value of information over public channels and the storage of client information on the browser.Several protocols have been introduced that maintain HTTP cookies,but many of those fail to achieve the required security,or require a lot of resource overheads.In this article,we have introduced a lightweight Elliptic Curve Cryptographic(ECC)based protocol for authenticating client and server transactions to maintain the privacy and security of HTTP cookies.Our proposed protocol uses a secret key embedded within a cookie.The proposed protocol ismore efficient and lightweight than related protocols because of its reduced computation,storage,and communication costs.Moreover,the analysis presented in this paper confirms that proposed protocol resists various known attacks.展开更多
Rhodopsin is a seven-helical transmembrane protein with a retinal chromophore covalently bound to a conserved lysine in helix G via a retinal protonated Schiff base(RPSB).Microbial rhodopsins absorb light through chro...Rhodopsin is a seven-helical transmembrane protein with a retinal chromophore covalently bound to a conserved lysine in helix G via a retinal protonated Schiff base(RPSB).Microbial rhodopsins absorb light through chromophore and play a fundamental role in optogenetics.Numerous microbial rhodopsins have been discovered,contributing to diverse functions and colors.Solid-state NMR spectroscopy has been instrumental in elucidating the conformation of chromophores and the three-dimensional structure of microbial rhodopsins.This review focuses on the 15N chemical shift values of RPSB and summarizes recent progress in the field.We displayed the correlation between the 15N isotropic chemical shift values of RPSB and the maximum absorption wavelength of rhodopsin using solid-state NMR spectroscopy.展开更多
MgH_(2) and TiH_(2) have been extensively studied as potential anode materials due to their high theoretical specific capacities of 2036 and 1024 mAh/g,respectively.However,the large volume changes that these compound...MgH_(2) and TiH_(2) have been extensively studied as potential anode materials due to their high theoretical specific capacities of 2036 and 1024 mAh/g,respectively.However,the large volume changes that these compounds undergo during cycling affects their performance and limits practical applications.The present work demonstrates a novel approach to limiting the volume changes of active materials.This effect is based on mechanical support from an intimate interface generated in situ via the reaction between MgH_(2) and Ti within the electrode prior to lithiation to form Mg and TiH_(2).The resulting Mg can be transformed back to MgH_(2) by reaction with LiH during delithiation.In addition,the TiH_(2) improves the reaction kinetics of MgH_(2) and enhances electrochemical performance.The intimate interface produced in this manner is found to improve the electrochemical properties of a MgH_(2)-Ti-LiH electrode.An exceptional reversible capacity of 800 mAh/g is observed even after 200 cycles with a high current density of 1 mA/cm^(2) and a high proportion of active material(90 wt.%)at an operation temperature of 120℃.This study therefore showcases a new means of improving the performance of electrodes by limiting the volume changes of active materials.展开更多
Learning from demonstration is widely regarded as a promising paradigm for robots to acquire diverse skills.Other than the artificial learning from observation-action pairs for machines,humans can learn to imitate in ...Learning from demonstration is widely regarded as a promising paradigm for robots to acquire diverse skills.Other than the artificial learning from observation-action pairs for machines,humans can learn to imitate in a more versatile and effective manner:acquiring skills through mere“observation”.Video to Command task is widely perceived as a promising approach for task-based learning,which yet faces two key challenges:(1)High redundancy and low frame rate of fine-grained action sequences make it difficult to manipulate objects robustly and accurately.(2)Video to Command models often prioritize accuracy and richness of output commands over physical capabilities,leading to impractical or unsafe instructions for robots.This article presents a novel Video to Command framework that employs multiple data associations and physical constraints.First,we introduce an object-level appearancecontrasting multiple data association strategy to effectively associate manipulated objects in visually complex environments,capturing dynamic changes in video content.Then,we propose a multi-task Video to Command model that utilizes object-level video content changes to compile expert demonstrations into manipulation commands.Finally,a multi-task hybrid loss function is proposed to train a Video to Command model that adheres to the constraints of the physical world and manipulation tasks.Our method achieved over 10%on BLEU_N,METEOR,ROUGE_L,and CIDEr compared to the up-to-date methods.The dual-arm robot prototype was established to demonstrate the whole process of learning from an expert demonstration of multiple skills and then executing the tasks by a robot.展开更多
There are many short-lived animals,but those displaying a lifecycle with more than one generation per year(multivoltine lifecycle)are rare amongterrestrial vertebrates.The multivoltine lifecycle requires rapid growth ...There are many short-lived animals,but those displaying a lifecycle with more than one generation per year(multivoltine lifecycle)are rare amongterrestrial vertebrates.The multivoltine lifecycle requires rapid growth and maturation and a long active season.Thus,small lizards in humidtropical or subtropical areas are candidates for multivoltine lifecycles.To test this prediction,we conducted a capture-mark-recapture study of asubtropical grass lizard,Takydromus toyamai,endemic to Miyako Islands,Japan.Juveniles grew very quickly,averaging 0.3 mm/day in the warmseason,and attained sexual maturity at 2.5 months post-hatching.The breeding season was very long,and hatchlings emerged from May toNovember.The prolonged breeding season and rapid growth to maturity allowed some individuals to produce a second generation in their frstyear.Estimates of hatching date from growth rates indicated that many females that hatched in May-June became gravid 76-120 days afterhatching and 122-165 days after oviposition of the eggs from which they hatched.Analyses of juvenile survivorship and month of hatching suggest that nearly half of breeding adults were members of multivoltine generations,although the 2 generations were not discrete.The species isshort-lived,with only 16% of individuals surviving beyond 12 months,and few individuals reproduced in a second year.We refer to this conditionas a“semi-multivoltine lifecycle.”Individuals that hatch late in the season defer reproduction until the following year and become founders ofthe next season’s cohort.This putative advantage of late-hatching individuals may have driven the evolution of this lifecycle.展开更多
Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recover...Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recovery ventilator and to investigate the effect of the air supply arrangement. Three types of mixing ventilation are chosen for the analysis of coupling ANSYS/FLUENT (a computational fluid dynamics (CFD) program) with TRNSYS (a building energy simulation (BES) software). The adoption of mutual complementary boundary conditions for CFD and BES provides more accurate and complete information of indoor air distribution and thermal performance in buildings. A typical office-space situated in a middle storey is chosen for the analysis. The office-space is equipped with air-conditioners on the ceiling. A heat recovery ventilation system directly supplies flesh air to the office space. Its thermal performance and indoor air distribution predicted by the coupled method are compared under three types of ventilation system. When the supply and return openings for ventilation are arranged on the ceiling, there is no critical difference between the predictions of the coupled method and BES on the energy consumption of HVAC because PID control is adopted for the supply air temperature of the occupied zone. On the other hand, approximately 21% discrepancy for the heat recovery estimation in the maximum between the simulated results of coupled method and BES-only can be obviously found in the floor air supply ventilation case. The discrepancy emphasizes the necessity of coupling CFD with BES when vertical air temperature gradient exists. Our future target is to estimate the optimum design of heat recovery ventilation system to control CO2 concentration by adjusting flow rate of flesh air.展开更多
We present a study concerning Fe-0. 176C-1.31Si-1.58Mn-0.26Al-0.3Cr (wt%) steel subjected to a quenching and partitioning (Q&P) process. The results of scanning electron microscopy, transmission electron microsco...We present a study concerning Fe-0. 176C-1.31Si-1.58Mn-0.26Al-0.3Cr (wt%) steel subjected to a quenching and partitioning (Q&P) process. The results of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and tensile tests demon- strate that the microstructures primarily consist of lath martensite, retained austenite, lower bainite (LB), and a small amount of tempered martensite; moreover, few twin austenite grains were observed. In the microstrucmre, three types of retained austenite with different sizes and morphologies were observed: blocky retained austenite (-300 nm in width), film-like retained austenite (80-120 nm in width), and ul- tra-fine film-like retained austenite (30-40 nm in width). Because of the effect of the retained austenite/martensite/LB triplex microstructure, the specimens prepared using different quenching temperatures exhibit high ultimate tensile strength and yield strength. Furthermore, the strength effect of LB can partially counteract the decreasing strength effect of martensite. The formation of LB substantially reduces the amount of retained austenite. Analyses of the retained austenite and the amount of blocky retained austenite indicated that the carbon content is critical to the total elongation of Q&P steel.展开更多
A nested circulation model system based on the Princeton ocean model (POM) is set up to simulate the currentmeter data from a bottom-mounted Acoustic Doppler Profiler (ADP) deployed at the 30 m depth in the Lunan...A nested circulation model system based on the Princeton ocean model (POM) is set up to simulate the currentmeter data from a bottom-mounted Acoustic Doppler Profiler (ADP) deployed at the 30 m depth in the Lunan(South Shandong Province, China) Trough south of the Shandong Peninsula in the summer of 2008, and to study the dynamics of the circulation in the southwestern Huanghai Sea (Yellow Sea). The model has reproduced well the observed subtidal current at the mooring site. The results of the model simulation suggest that the bottom topography has strong steering effects on the regional circulation in summer. The model simulation shows that the Subei (North Jiangsu Province, China)coastal current flows north- ward in summer, in contrast to the southeastward current in the center of the Lunan Trough measured by the moored currentmeter. The analyses of the model results suggest that the southeastward current at the mooring site in the Lunan Trough is forced by the westward wind-driven current along the Lunan coast, which meets the northward Subei coastal current at the head of the Haizhou Bay to flow along an offshore path in the southeastward direction in the Lunan Trough. Analysis suggests that the Subei coastal current, the Lunan coastal current, and the circulation in the Lunan Trough are independent current systems con- trolled by different dynamics. Therefore, the current measurements in the Lunan Trough cannot be used to represent the Subei coastal current in general.展开更多
In underground mines, high air temperatures in the summer months lead to an increase in inlet airflow temperatures. This leads to seasonal thermal pollution in the mines. This paper examines the dynamics and effects o...In underground mines, high air temperatures in the summer months lead to an increase in inlet airflow temperatures. This leads to seasonal thermal pollution in the mines. This paper examines the dynamics and effects of seasonal variation in surface air temperatures and surrounding rock temperatures in deep coal mines. It also examines temperature variations in the main ventilation circuit, working face, and surrounding rock. The study results revealed that airflow temperatures were significantly affected by seasonal air temperature variations. The greater the distance was between the inlet and the wellhead of the ventilation shaft, the less the effect was on temperature. Moreover, slight temperature variations (1.0-3.0 ℃) were observed between various points on the return route during the summer months. Airflow temperatures along the airflow inlet to the return route of the working face first decreased, but then increased. The temperature field of the surrounding rock increased gradually with increased distance between the mine roadway and inlet, with recorded rock temperatures as high as 40.53 ℃. The radius of the heat-adjusting layer was between 28 and 33 m.展开更多
The adsorption/plasma decomposition with the combination of adsorption honeycomb-sheets and a plasma element is a new technology for small-sized apparatuses to decompose volatile organic compounds (VOCs) at concentr...The adsorption/plasma decomposition with the combination of adsorption honeycomb-sheets and a plasma element is a new technology for small-sized apparatuses to decompose volatile organic compounds (VOCs) at concentrations lower than about 100 ppm. The feasibility of the prototype adsorption/plasma decomposition apparatus was evaluated with the simulated exhausts containing one VOC component and with real exhausts from a painting booth and an adhesion factory. The apparatus decomposed VOCs effectively at the painting booth exhaust but not always satisfactorily at the adhesion factory exhaust. The performance test results with real exhausts were discussed with respect to the concentration and discharge pattern of the exhausts and the basic properties of the system such as cooperation of adsorption and plasma reaction and the concentration dependence of the performance.展开更多
An overview of diagnostic tools e test limiters and collector probes e used over the years for material migration studies in the TEXTOR tokamak is presented.Probe transfer systems are shown and their technical capabil...An overview of diagnostic tools e test limiters and collector probes e used over the years for material migration studies in the TEXTOR tokamak is presented.Probe transfer systems are shown and their technical capabilities are described.This is accompanied by a brief pre-sentation of selected results and conclusions from the research on material erosion e deposition processes including tests of candidate materials(e.g.W,Mo,carbon-based composites)for plasma-facing components in controlled fusion devices.The use of tracer techniques and methods for analysis of materials retrieved from the tokamak are summarized.The impact of research on the reactor wall technology is addressed.展开更多
Many experiment researches have been developed before. But most of them were carried out with the condition that the tunnel’s ratio of length and diameter (x/D) is under 1000. Recently, the process that compression w...Many experiment researches have been developed before. But most of them were carried out with the condition that the tunnel’s ratio of length and diameter (x/D) is under 1000. Recently, the process that compression wave convents into shock wave in the overlong tunnel has also been paid attention. In this paper, features of shock wave as it propagates through a overlong tunnel is investigated, rupturing thin films at the entrance to obtain three kinds of shock wave with different intensities. Then study their features respectively during they propagates through a overlong tunnel with x/D over 6000 at most. Comprehend shock wave more deeply by comparing the results of experiments.展开更多
The trend of distance learning education has increased year by year because of the rapid advancement of information and communication technologies. Distance learning system can be regarded as one of ubiquitous computi...The trend of distance learning education has increased year by year because of the rapid advancement of information and communication technologies. Distance learning system can be regarded as one of ubiquitous computing applications since the learners can study anywhere even in mobile environments. However, the instructor cannot know if the learners comprehend the lecture or not since each learner is physically isolated. Therefore, a framework which detects the learners’ concentration condition is required. If a distance learning system obtains the information that many learners are not concentrated on the class due to the incomprehensible lecture style, the instructor can perceive it through the system and change the presentation strategy. This is a context-aware technology which is widely used for ubiquitous computing services. In this paper, an efficient distance learning system, which accurately detects learners’ concentration condition during a class, is proposed. The proposed system uses multiple biological information which are learners’ eye movement metrics, i.e. fixation counts, fixation rate, fixation duration and average saccade length obtained by an eye tracking system. The learners’ concentration condition is classified by using machine learning techniques. The proposed system has performed the detection accuracy of 90.7% when Multilayer Perceptron is used as a classifier. In addition, the effectiveness of the proposed eye metrics has been confirmed. Furthermore, it has been clarified that the fixation duration is the most important eye metric among the four metrics based on the investigation of evaluation experiment.展开更多
Skeletochronology is a method commonly used for estimating the age of amphibians and reptiles in the wild. However, the number of lines of arrested growth (LAGs) does not necessarily reflect age in some species. We ...Skeletochronology is a method commonly used for estimating the age of amphibians and reptiles in the wild. However, the number of lines of arrested growth (LAGs) does not necessarily reflect age in some species. We validated the applicability of this method to an endangered eublepharid gecko, Goniurosaurus kuroiwae, then inferred its longevity and age structures in wild populations. We classified young geckos into three groups using previously published data for early growth: Group 1 contained hatchlings before the first winter, Group 2 contained hatchlings after the first win- ter, and Group 3 included yearlings after the second winter. LAG numbers in these groups were then compared. All individuals in Group 1 possessed a single LAG, which was considered as a hatching line. Most individuals in Groups 2 and 3 possessed one and two additional LAGs, respectively (LAG1 and LAG2), corroborating the notion that LAGs are formed annually. A few geckos exhibited fewer LAGs than expected. Analysis of variations in LAG and marrow cavity diameter demonstrated that in animals with fewer LAGs, endosteal resorption or fusion of hatching line and LAG1 had occurred. LAG2 was never lost by endosteal resorption and was identifiable by its diameter. Thus, the age of adult geckos could be determined by counting LAGs outward from LAG2. Application of this method to wild populations re- vealed that the longevity of this species is not less than 83 months, but that almost all individuals in fragmented habitats die before 50 months, suggesting lower population sustainability in such habitats.展开更多
In this work, low-carbon steel specimens were subjected to the quenching and partitioning process after being partially or fully austenitized to investigate their microstructural evolution and mechanical properties. A...In this work, low-carbon steel specimens were subjected to the quenching and partitioning process after being partially or fully austenitized to investigate their microstructural evolution and mechanical properties. According to the results of scanning electron microscopy and transmission electron microscopy observations, X-ray diffraction analysis, and tensile tests, upper bainite or tempered martensite appears successively in the microstructure with increasing austenitization temperature or increasing partitioning time. In the partially austenitized specimens, the retained austenite grains are carbon-enriched twice during the heat treatment, which can significantly stabilize the phases at room temperature. Furthermore, after partial austenitization, the specimen exhibits excellent elongation, with a maximum elongation of 37.1%. By contrast, after full austenitization, the specimens exhibit good ultimate tensile strength and high yield strength. In the case of a specimen with a yield strength of 969 MPa, the maximum value of the ultimate tensile strength reaches 1222 MPa. During the partitioning process, carbon partitioning and carbon homogenization within austenite affect interface migration. In addition, the volume fraction and grain size of retained austenite observed in the final microstructure will also be affected.展开更多
This research aimed to mechanically analyze vertebral stress concentration in one healthy subject and one subject with osteoporotic first lumbar (L1) vertebral compression fracture by using finite element analysis (FE...This research aimed to mechanically analyze vertebral stress concentration in one healthy subject and one subject with osteoporotic first lumbar (L1) vertebral compression fracture by using finite element analysis (FEA). We constructed three-dimensional image-based finite element (FE) models (Th12L2) by using computed tomographic (CT) digital imaging and communications in medicine (DICOM) for each patient and then conducted exercise stress simulations on the spine models. The loadings on the 12th thoracic vertebra (Th12) due to compression, flexion, extension, lateral bending, and axial rotation were examined within the virtual space for both spine models. The healthy and vertebral compression fracture models were then compared based on the application of equivalent vertebral stress. The comparison showed that vertebral stress concentration increased with all stresses in the vertebral compression fracture models. In particular, compression and axial rotation caused remarkable increases in stress concentration in the vertebral compression fracture models. These results suggest that secondary vertebral compression fractures are caused not only by bone fragility but possibly also by the increase in vertebral stress concentration around the site of the initial展开更多
A millimeter wave solid state source—far infrared laser combined interferometer system(MFCI)consisting of a three-channel 890 GHz hydrogen cyanide(HCN)laser interferometer and a threechannel 340 GHz solid state sourc...A millimeter wave solid state source—far infrared laser combined interferometer system(MFCI)consisting of a three-channel 890 GHz hydrogen cyanide(HCN)laser interferometer and a threechannel 340 GHz solid state source interferometer(SSI)is developed for real-time line-integrated electron density feedback and electron density profile of the EXL-50 spherical tokamak device.The interferometer system is a Mach–Zehnder type,with all probe-channels measured vertically,covering the plasma magnetic axis to the outermost closed magnetic plane.The HCN laser interferometer uses an HCN laser with a frequency of 890 GHz as a light source and modulates a100 k Hz beat signal by a rotating grating,giving a temporal resolution of 10μs.The SSI uses two independent 340 GHz solid-state diode sources as the light source,the frequency of the two sources is adjustable,and the temporal resolution of SSI can reach 1μs by setting the frequency difference of the two lasers at 1 MHz.The main optical path of the two interferometers is compactly installed on a set of double-layer optical platform directly below EXL-50.Dual optical path design using corner cube reflectors avoids the large support structures.Collinear the probebeams of two wavelengths,then the phase error caused by vibration can be compensated.At present,the phase noise of the HCN Interferometer is 0.08 rad,corresponding to a line-integrated electron density of 0.88×10^(17)m^(-2),one channel of measuring result was obtained by the MFCI system,and the highest density measured is about 0.7×10^(19)m^(-2).展开更多
A compression wave is generated ahead of a high-speed train, while entering a tunnel. This compression wave propa- gates to the tunnel exit and spouts out as a micro pressure wave, causing an exploding sound. In order...A compression wave is generated ahead of a high-speed train, while entering a tunnel. This compression wave propa- gates to the tunnel exit and spouts out as a micro pressure wave, causing an exploding sound. In order to estimate the magnitude correctly, the mechanism of the attenuation and distortion of a compression wave propagating along a tunnel must be understood and experimental information on these phenomena is required. An experimental and numerical in- vestigation is carried out to clarify the mechanism of the propagating compression wave in a tube. The final objective of our study is to understand the mechanism of the attenuation and distortion of propagating compression waves in a tun- nel. In the present paper, experimental investigations are carried out on the transition of the unsteady boundary layer induced by a propagating compression wave in a model tunnel by means of a developed laser differential interferometry technique.展开更多
基金supported by MEXT KAKENHI Grant(24K01295,26286013).
文摘Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachment and complex fabrication process introduce surface defects,compromising device stability and efficiency.In this work,we propose a solution-phase ligand exchange(SPLE)method utilizing inorganic ligands to develop stable p-type lead sulfide(PbS)CQD inks for the first time.Various amounts of tin(Ⅱ)iodide(SnI_(2))were mixed with lead halide(PbX_(2);X=I,Br)in the ligand solution.By precisely controlling the SnI_(2)concentration,we regulate the transition of PbS QDs from n-type to p-type.PbS CQDSCs were fabricated using two different HTL approaches:one with 1,2-ethanedithiol(EDT)-passivated QDs via the LbL method(control)and another with inorganic ligand-passivated QD ink(target).The target devices achieved a higher power conversion efficiency(PCE)of 10.93%,compared to 9.83%for the control devices.This improvement is attributed to reduced interfacial defects and enhanced carrier mobility.The proposed technique offers an efficient pathway for producing stable p-type PbS CQD inks using inorganic ligands,paving the way for high-performance and flexible CQD-based optoelectronic devices.
基金support from Abu Dhabi University’s Office of Research and Sponsored Programs Grant Number:19300810.
文摘Cookies are considered a fundamental means of web application services for authenticating various Hypertext Transfer Protocol(HTTP)requests andmaintains the states of clients’information over the Internet.HTTP cookies are exploited to carry client patterns observed by a website.These client patterns facilitate the particular client’s future visit to the corresponding website.However,security and privacy are the primary concerns owing to the value of information over public channels and the storage of client information on the browser.Several protocols have been introduced that maintain HTTP cookies,but many of those fail to achieve the required security,or require a lot of resource overheads.In this article,we have introduced a lightweight Elliptic Curve Cryptographic(ECC)based protocol for authenticating client and server transactions to maintain the privacy and security of HTTP cookies.Our proposed protocol uses a secret key embedded within a cookie.The proposed protocol ismore efficient and lightweight than related protocols because of its reduced computation,storage,and communication costs.Moreover,the analysis presented in this paper confirms that proposed protocol resists various known attacks.
基金supported in part by JSPS KAKENHI Grant Numbers in Japan(JP21H05229 to I.K.)JST CREST(JPMJCR21B2)The authors also thank Nobuko Yamaguchi for the financial support.
文摘Rhodopsin is a seven-helical transmembrane protein with a retinal chromophore covalently bound to a conserved lysine in helix G via a retinal protonated Schiff base(RPSB).Microbial rhodopsins absorb light through chromophore and play a fundamental role in optogenetics.Numerous microbial rhodopsins have been discovered,contributing to diverse functions and colors.Solid-state NMR spectroscopy has been instrumental in elucidating the conformation of chromophores and the three-dimensional structure of microbial rhodopsins.This review focuses on the 15N chemical shift values of RPSB and summarizes recent progress in the field.We displayed the correlation between the 15N isotropic chemical shift values of RPSB and the maximum absorption wavelength of rhodopsin using solid-state NMR spectroscopy.
基金supported in part by JSPS KAKENHI grants (nos. JP21K05243 and JP22H04621grants-in-aid for Scientific Research on Innovative Areas “Interface Ionics”)+1 种基金by a JST grant (no. JPMJFS2132,for the establishment of university fellowships toward the creation of science technology innovation)by the Suzuki foundation
文摘MgH_(2) and TiH_(2) have been extensively studied as potential anode materials due to their high theoretical specific capacities of 2036 and 1024 mAh/g,respectively.However,the large volume changes that these compounds undergo during cycling affects their performance and limits practical applications.The present work demonstrates a novel approach to limiting the volume changes of active materials.This effect is based on mechanical support from an intimate interface generated in situ via the reaction between MgH_(2) and Ti within the electrode prior to lithiation to form Mg and TiH_(2).The resulting Mg can be transformed back to MgH_(2) by reaction with LiH during delithiation.In addition,the TiH_(2) improves the reaction kinetics of MgH_(2) and enhances electrochemical performance.The intimate interface produced in this manner is found to improve the electrochemical properties of a MgH_(2)-Ti-LiH electrode.An exceptional reversible capacity of 800 mAh/g is observed even after 200 cycles with a high current density of 1 mA/cm^(2) and a high proportion of active material(90 wt.%)at an operation temperature of 120℃.This study therefore showcases a new means of improving the performance of electrodes by limiting the volume changes of active materials.
基金Supported by Zhejiang Provincial Key Research and Development Program(Grant No.2021C04015)。
文摘Learning from demonstration is widely regarded as a promising paradigm for robots to acquire diverse skills.Other than the artificial learning from observation-action pairs for machines,humans can learn to imitate in a more versatile and effective manner:acquiring skills through mere“observation”.Video to Command task is widely perceived as a promising approach for task-based learning,which yet faces two key challenges:(1)High redundancy and low frame rate of fine-grained action sequences make it difficult to manipulate objects robustly and accurately.(2)Video to Command models often prioritize accuracy and richness of output commands over physical capabilities,leading to impractical or unsafe instructions for robots.This article presents a novel Video to Command framework that employs multiple data associations and physical constraints.First,we introduce an object-level appearancecontrasting multiple data association strategy to effectively associate manipulated objects in visually complex environments,capturing dynamic changes in video content.Then,we propose a multi-task Video to Command model that utilizes object-level video content changes to compile expert demonstrations into manipulation commands.Finally,a multi-task hybrid loss function is proposed to train a Video to Command model that adheres to the constraints of the physical world and manipulation tasks.Our method achieved over 10%on BLEU_N,METEOR,ROUGE_L,and CIDEr compared to the up-to-date methods.The dual-arm robot prototype was established to demonstrate the whole process of learning from an expert demonstration of multiple skills and then executing the tasks by a robot.
基金supported fnancially by the Nanseishoto Project of WWFJ,Pro Natura Foundation Japan’s 31st Pro Natura Fundthe Project for Biodiversity Conservation Promotion of the Japan Ministry of the Environment.
文摘There are many short-lived animals,but those displaying a lifecycle with more than one generation per year(multivoltine lifecycle)are rare amongterrestrial vertebrates.The multivoltine lifecycle requires rapid growth and maturation and a long active season.Thus,small lizards in humidtropical or subtropical areas are candidates for multivoltine lifecycles.To test this prediction,we conducted a capture-mark-recapture study of asubtropical grass lizard,Takydromus toyamai,endemic to Miyako Islands,Japan.Juveniles grew very quickly,averaging 0.3 mm/day in the warmseason,and attained sexual maturity at 2.5 months post-hatching.The breeding season was very long,and hatchlings emerged from May toNovember.The prolonged breeding season and rapid growth to maturity allowed some individuals to produce a second generation in their frstyear.Estimates of hatching date from growth rates indicated that many females that hatched in May-June became gravid 76-120 days afterhatching and 122-165 days after oviposition of the eggs from which they hatched.Analyses of juvenile survivorship and month of hatching suggest that nearly half of breeding adults were members of multivoltine generations,although the 2 generations were not discrete.The species isshort-lived,with only 16% of individuals surviving beyond 12 months,and few individuals reproduced in a second year.We refer to this conditionas a“semi-multivoltine lifecycle.”Individuals that hatch late in the season defer reproduction until the following year and become founders ofthe next season’s cohort.This putative advantage of late-hatching individuals may have driven the evolution of this lifecycle.
基金Project supported by Grant-in-Aid for Scientific Research (JSPS KAKENHI for Young Scientists (S), 21676005)
文摘Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recovery ventilator and to investigate the effect of the air supply arrangement. Three types of mixing ventilation are chosen for the analysis of coupling ANSYS/FLUENT (a computational fluid dynamics (CFD) program) with TRNSYS (a building energy simulation (BES) software). The adoption of mutual complementary boundary conditions for CFD and BES provides more accurate and complete information of indoor air distribution and thermal performance in buildings. A typical office-space situated in a middle storey is chosen for the analysis. The office-space is equipped with air-conditioners on the ceiling. A heat recovery ventilation system directly supplies flesh air to the office space. Its thermal performance and indoor air distribution predicted by the coupled method are compared under three types of ventilation system. When the supply and return openings for ventilation are arranged on the ceiling, there is no critical difference between the predictions of the coupled method and BES on the energy consumption of HVAC because PID control is adopted for the supply air temperature of the occupied zone. On the other hand, approximately 21% discrepancy for the heat recovery estimation in the maximum between the simulated results of coupled method and BES-only can be obviously found in the floor air supply ventilation case. The discrepancy emphasizes the necessity of coupling CFD with BES when vertical air temperature gradient exists. Our future target is to estimate the optimum design of heat recovery ventilation system to control CO2 concentration by adjusting flow rate of flesh air.
基金funded by the China Scholarship Council (No. 201406460053)
文摘We present a study concerning Fe-0. 176C-1.31Si-1.58Mn-0.26Al-0.3Cr (wt%) steel subjected to a quenching and partitioning (Q&P) process. The results of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and tensile tests demon- strate that the microstructures primarily consist of lath martensite, retained austenite, lower bainite (LB), and a small amount of tempered martensite; moreover, few twin austenite grains were observed. In the microstrucmre, three types of retained austenite with different sizes and morphologies were observed: blocky retained austenite (-300 nm in width), film-like retained austenite (80-120 nm in width), and ul- tra-fine film-like retained austenite (30-40 nm in width). Because of the effect of the retained austenite/martensite/LB triplex microstructure, the specimens prepared using different quenching temperatures exhibit high ultimate tensile strength and yield strength. Furthermore, the strength effect of LB can partially counteract the decreasing strength effect of martensite. The formation of LB substantially reduces the amount of retained austenite. Analyses of the retained austenite and the amount of blocky retained austenite indicated that the carbon content is critical to the total elongation of Q&P steel.
基金The 973 Project of China under contract No.2012CB95600the National Natural Science Foundation of China under contract Nos 40888001 and 41176019+1 种基金the Chinese Academy of Sciences under contract No. KZCX2-YW-JS204Qingdao Municipal under contract No.10-3-3-38jh
文摘A nested circulation model system based on the Princeton ocean model (POM) is set up to simulate the currentmeter data from a bottom-mounted Acoustic Doppler Profiler (ADP) deployed at the 30 m depth in the Lunan(South Shandong Province, China) Trough south of the Shandong Peninsula in the summer of 2008, and to study the dynamics of the circulation in the southwestern Huanghai Sea (Yellow Sea). The model has reproduced well the observed subtidal current at the mooring site. The results of the model simulation suggest that the bottom topography has strong steering effects on the regional circulation in summer. The model simulation shows that the Subei (North Jiangsu Province, China)coastal current flows north- ward in summer, in contrast to the southeastward current in the center of the Lunan Trough measured by the moored currentmeter. The analyses of the model results suggest that the southeastward current at the mooring site in the Lunan Trough is forced by the westward wind-driven current along the Lunan coast, which meets the northward Subei coastal current at the head of the Haizhou Bay to flow along an offshore path in the southeastward direction in the Lunan Trough. Analysis suggests that the Subei coastal current, the Lunan coastal current, and the circulation in the Lunan Trough are independent current systems con- trolled by different dynamics. Therefore, the current measurements in the Lunan Trough cannot be used to represent the Subei coastal current in general.
基金This work was supported by the National Natural Science Foundation of China (Nos. 5157-4139 and 5180-4247)De Montfort University through its distinguished Vice-Chancellor 2020 ProgrammeUK Science and Technology Facilities Council (STFC) through Batteries Early Career Researcher Award.
文摘In underground mines, high air temperatures in the summer months lead to an increase in inlet airflow temperatures. This leads to seasonal thermal pollution in the mines. This paper examines the dynamics and effects of seasonal variation in surface air temperatures and surrounding rock temperatures in deep coal mines. It also examines temperature variations in the main ventilation circuit, working face, and surrounding rock. The study results revealed that airflow temperatures were significantly affected by seasonal air temperature variations. The greater the distance was between the inlet and the wellhead of the ventilation shaft, the less the effect was on temperature. Moreover, slight temperature variations (1.0-3.0 ℃) were observed between various points on the return route during the summer months. Airflow temperatures along the airflow inlet to the return route of the working face first decreased, but then increased. The temperature field of the surrounding rock increased gradually with increased distance between the mine roadway and inlet, with recorded rock temperatures as high as 40.53 ℃. The radius of the heat-adjusting layer was between 28 and 33 m.
基金supported by Okabe MicaCo.,Ltd.and NEDO (New Energy and Industrial Technology Development Organization) of Japan
文摘The adsorption/plasma decomposition with the combination of adsorption honeycomb-sheets and a plasma element is a new technology for small-sized apparatuses to decompose volatile organic compounds (VOCs) at concentrations lower than about 100 ppm. The feasibility of the prototype adsorption/plasma decomposition apparatus was evaluated with the simulated exhausts containing one VOC component and with real exhausts from a painting booth and an adhesion factory. The apparatus decomposed VOCs effectively at the painting booth exhaust but not always satisfactorily at the adhesion factory exhaust. The performance test results with real exhausts were discussed with respect to the concentration and discharge pattern of the exhausts and the basic properties of the system such as cooperation of adsorption and plasma reaction and the concentration dependence of the performance.
文摘An overview of diagnostic tools e test limiters and collector probes e used over the years for material migration studies in the TEXTOR tokamak is presented.Probe transfer systems are shown and their technical capabilities are described.This is accompanied by a brief pre-sentation of selected results and conclusions from the research on material erosion e deposition processes including tests of candidate materials(e.g.W,Mo,carbon-based composites)for plasma-facing components in controlled fusion devices.The use of tracer techniques and methods for analysis of materials retrieved from the tokamak are summarized.The impact of research on the reactor wall technology is addressed.
文摘Many experiment researches have been developed before. But most of them were carried out with the condition that the tunnel’s ratio of length and diameter (x/D) is under 1000. Recently, the process that compression wave convents into shock wave in the overlong tunnel has also been paid attention. In this paper, features of shock wave as it propagates through a overlong tunnel is investigated, rupturing thin films at the entrance to obtain three kinds of shock wave with different intensities. Then study their features respectively during they propagates through a overlong tunnel with x/D over 6000 at most. Comprehend shock wave more deeply by comparing the results of experiments.
文摘The trend of distance learning education has increased year by year because of the rapid advancement of information and communication technologies. Distance learning system can be regarded as one of ubiquitous computing applications since the learners can study anywhere even in mobile environments. However, the instructor cannot know if the learners comprehend the lecture or not since each learner is physically isolated. Therefore, a framework which detects the learners’ concentration condition is required. If a distance learning system obtains the information that many learners are not concentrated on the class due to the incomprehensible lecture style, the instructor can perceive it through the system and change the presentation strategy. This is a context-aware technology which is widely used for ubiquitous computing services. In this paper, an efficient distance learning system, which accurately detects learners’ concentration condition during a class, is proposed. The proposed system uses multiple biological information which are learners’ eye movement metrics, i.e. fixation counts, fixation rate, fixation duration and average saccade length obtained by an eye tracking system. The learners’ concentration condition is classified by using machine learning techniques. The proposed system has performed the detection accuracy of 90.7% when Multilayer Perceptron is used as a classifier. In addition, the effectiveness of the proposed eye metrics has been confirmed. Furthermore, it has been clarified that the fixation duration is the most important eye metric among the four metrics based on the investigation of evaluation experiment.
基金supported by the Zoshinkai Fund for Protection of Endangered Animals and the Grant from the Japan Society for the Promotion of Science (JSPS KAKENHI Grant number 22510244)
文摘Skeletochronology is a method commonly used for estimating the age of amphibians and reptiles in the wild. However, the number of lines of arrested growth (LAGs) does not necessarily reflect age in some species. We validated the applicability of this method to an endangered eublepharid gecko, Goniurosaurus kuroiwae, then inferred its longevity and age structures in wild populations. We classified young geckos into three groups using previously published data for early growth: Group 1 contained hatchlings before the first winter, Group 2 contained hatchlings after the first win- ter, and Group 3 included yearlings after the second winter. LAG numbers in these groups were then compared. All individuals in Group 1 possessed a single LAG, which was considered as a hatching line. Most individuals in Groups 2 and 3 possessed one and two additional LAGs, respectively (LAG1 and LAG2), corroborating the notion that LAGs are formed annually. A few geckos exhibited fewer LAGs than expected. Analysis of variations in LAG and marrow cavity diameter demonstrated that in animals with fewer LAGs, endosteal resorption or fusion of hatching line and LAG1 had occurred. LAG2 was never lost by endosteal resorption and was identifiable by its diameter. Thus, the age of adult geckos could be determined by counting LAGs outward from LAG2. Application of this method to wild populations re- vealed that the longevity of this species is not less than 83 months, but that almost all individuals in fragmented habitats die before 50 months, suggesting lower population sustainability in such habitats.
基金funded by China Scholarship Council (No. 201406460053)
文摘In this work, low-carbon steel specimens were subjected to the quenching and partitioning process after being partially or fully austenitized to investigate their microstructural evolution and mechanical properties. According to the results of scanning electron microscopy and transmission electron microscopy observations, X-ray diffraction analysis, and tensile tests, upper bainite or tempered martensite appears successively in the microstructure with increasing austenitization temperature or increasing partitioning time. In the partially austenitized specimens, the retained austenite grains are carbon-enriched twice during the heat treatment, which can significantly stabilize the phases at room temperature. Furthermore, after partial austenitization, the specimen exhibits excellent elongation, with a maximum elongation of 37.1%. By contrast, after full austenitization, the specimens exhibit good ultimate tensile strength and high yield strength. In the case of a specimen with a yield strength of 969 MPa, the maximum value of the ultimate tensile strength reaches 1222 MPa. During the partitioning process, carbon partitioning and carbon homogenization within austenite affect interface migration. In addition, the volume fraction and grain size of retained austenite observed in the final microstructure will also be affected.
文摘This research aimed to mechanically analyze vertebral stress concentration in one healthy subject and one subject with osteoporotic first lumbar (L1) vertebral compression fracture by using finite element analysis (FEA). We constructed three-dimensional image-based finite element (FE) models (Th12L2) by using computed tomographic (CT) digital imaging and communications in medicine (DICOM) for each patient and then conducted exercise stress simulations on the spine models. The loadings on the 12th thoracic vertebra (Th12) due to compression, flexion, extension, lateral bending, and axial rotation were examined within the virtual space for both spine models. The healthy and vertebral compression fracture models were then compared based on the application of equivalent vertebral stress. The comparison showed that vertebral stress concentration increased with all stresses in the vertebral compression fracture models. In particular, compression and axial rotation caused remarkable increases in stress concentration in the vertebral compression fracture models. These results suggest that secondary vertebral compression fractures are caused not only by bone fragility but possibly also by the increase in vertebral stress concentration around the site of the initial
基金supported by the National MCF Energy R&D Program(Nos.2019YFE03040003 and 2017YFE0301205)supported in part by Key Program of Research and Development of Hefei Science Center,CAS(No.2019HSC-KPRD001)partly supported by the Collaborative Research Program of the Research Institute for Applied Mechanics,Kyushu University.
文摘A millimeter wave solid state source—far infrared laser combined interferometer system(MFCI)consisting of a three-channel 890 GHz hydrogen cyanide(HCN)laser interferometer and a threechannel 340 GHz solid state source interferometer(SSI)is developed for real-time line-integrated electron density feedback and electron density profile of the EXL-50 spherical tokamak device.The interferometer system is a Mach–Zehnder type,with all probe-channels measured vertically,covering the plasma magnetic axis to the outermost closed magnetic plane.The HCN laser interferometer uses an HCN laser with a frequency of 890 GHz as a light source and modulates a100 k Hz beat signal by a rotating grating,giving a temporal resolution of 10μs.The SSI uses two independent 340 GHz solid-state diode sources as the light source,the frequency of the two sources is adjustable,and the temporal resolution of SSI can reach 1μs by setting the frequency difference of the two lasers at 1 MHz.The main optical path of the two interferometers is compactly installed on a set of double-layer optical platform directly below EXL-50.Dual optical path design using corner cube reflectors avoids the large support structures.Collinear the probebeams of two wavelengths,then the phase error caused by vibration can be compensated.At present,the phase noise of the HCN Interferometer is 0.08 rad,corresponding to a line-integrated electron density of 0.88×10^(17)m^(-2),one channel of measuring result was obtained by the MFCI system,and the highest density measured is about 0.7×10^(19)m^(-2).
文摘A compression wave is generated ahead of a high-speed train, while entering a tunnel. This compression wave propa- gates to the tunnel exit and spouts out as a micro pressure wave, causing an exploding sound. In order to estimate the magnitude correctly, the mechanism of the attenuation and distortion of a compression wave propagating along a tunnel must be understood and experimental information on these phenomena is required. An experimental and numerical in- vestigation is carried out to clarify the mechanism of the propagating compression wave in a tube. The final objective of our study is to understand the mechanism of the attenuation and distortion of propagating compression waves in a tun- nel. In the present paper, experimental investigations are carried out on the transition of the unsteady boundary layer induced by a propagating compression wave in a model tunnel by means of a developed laser differential interferometry technique.