Referring expression comprehension(REC)aims to locate a specific region in an image described by a natural language.Existing two-stage methods generate multiple candidate proposals in the first stage,followed by selec...Referring expression comprehension(REC)aims to locate a specific region in an image described by a natural language.Existing two-stage methods generate multiple candidate proposals in the first stage,followed by selecting one of these proposals as the grounding result in the second stage.Nevertheless,the number of candidate proposals generated in the first stage significantly exceeds ground truth and the recall of critical objects is inadequate,thereby enormously limiting the overall network performance.To address the above issues,the authors propose an innovative method termed Separate Non-Maximum Suppression(Sep-NMS)for two-stage REC.Particularly,Sep-NMS models information from the two stages independently and collaboratively,ultimately achieving an overall improvement in comprehension and identification of the target objects.Specifically,the authors propose a Ref-Relatedness module for filtering referent proposals rigorously,decreasing the redundancy of referent proposals.A CLIP†Relatedness module based on robust multimodal pre-trained encoders is built to precisely assess the relevance between language and proposals to improve the recall of critical objects.It is worth mentioning that the authors are the pioneers in utilising a multimodal pre-training model for proposal filtering in the first stage.Moreover,an Information Fusion module is designed to effectively amalgamate the multimodal information across two stages,ensuring maximum uti-lisation of the available information.Extensive experiments demonstrate that the approach achieves competitive performance with previous state-of-the-art methods.The datasets used are publicly available:RefCOCO,RefCOCO+:https://doi.org/10.1007/978-3-319-46475-6_5 and RefCOCOg:https://doi.org/10.1109/CVPR.2016.9.展开更多
To address the issue of disturbance compensation deviation in linear active disturbance rejection control(LADRC),a linear active disturbance rejection control method with reference to the integral chain model(LADRC-R)...To address the issue of disturbance compensation deviation in linear active disturbance rejection control(LADRC),a linear active disturbance rejection control method with reference to the integral chain model(LADRC-R)is proposed.By constructing an ideal control reference model,a dynamic correlation between output deviation and uncompensated disturbances is established,and a dual-loop compensation mechanism is designed.Based on theoretical analysis and frequency-domain characteristics of typical first/second-order systems,this method maintains the parameter-tuning advantages of LADRC while reducing disturbance effects by 50%and introducing no phase lag during low-frequency disturbance suppression.Simulations on second-order systems verify its robustness under parameter perturbations,gain mismatch,and complex disturbances,and an optimized design scheme for the deviation compensator is proposed to suppress discontinuous measurement noise interference.Finally,the engineering effectiveness of this method in precision motion control is validated on an electromagnetic suspension platform,providing a new approach to improving the control performance of LADRC in environments with uncertain disturbances.展开更多
Background: Justification is the process of weighing the potential benefit of the exposure against potential detriment for that individual. Its role has been largely delegated to imaging professionals. Nevertheless, j...Background: Justification is the process of weighing the potential benefit of the exposure against potential detriment for that individual. Its role has been largely delegated to imaging professionals. Nevertheless, justification process involves referring physicians, radiographers and radiologists. Objective: To assess the knowledge of referring physicians regarding justification of irradiating examinations in medical imaging at the university-affiliated hospitals in Yaoundé Cameroon. Materials and Methods: A questionnaire (18 questions) based on the French guide for the proper use of medical imaging tests in relation to the justification of irradiating examinations, was self-administered to 151 referring physicians in Yaounde (Cameroon) between October 2012 and January 2013. The pre-tested questionnaire was completed in the presence of the investigator. A scoring system was then adopted with a total of 15 points from the level of knowledge on justification which could be classified as satisfactory or not. Results: Referring physicians were 75 (49.7%) GPs, 53 (35.1%) residents and 23 (15.2%) specialists. Knowledge on justification was unsatisfactory for 79.5% of referring physicians with no significant difference in terms of professional experience (p = 0.95) or specialty (p = 0.119). The concepts of “useful exam” and “justified exam” were not known by 113 (74.8%) and 95 (62.9%) practitioners. MRI was selected as irradiating by 62 (41.1%), SPECT and PET-scan as non-radiating examinations by 98 (64.9%) and 115 (76.1%) participants. The main reasons for repeating a giving radiology exam were: unsatisfactory interpretation, unknown of where it was performing and poor quality exam respectively for 23 (15.2%), 37 (24.5%) and 43 (28.5%) referring physicians. Justification was the responsibility of the referring physician alone for 57% of respondent. Only 11 clinicians knew the reference of “Justification-Optimization-Limitation” to radiation protection. Conclusion: The knowledge of physicians on radiating medical procedures and justification of requests for these procedures is inadequate. Training in radiation protection and the introduction of guidelines for the proper use of imaging tests could improve physicians’ justification of radiating examinations.展开更多
Referring expressions comprehension is the task of locating the image region described by a natural language expression,which refer to the properties of the region or the relationships with other regions.Most previous...Referring expressions comprehension is the task of locating the image region described by a natural language expression,which refer to the properties of the region or the relationships with other regions.Most previous work handles this problem by selecting the most relevant regions from a set of candidate regions,when there are many candidate regions in the set these methods are inefficient.Inspired by recent success of image captioning by using deep learning methods,in this paper we proposed a framework to understand the referring expressions by multiple steps of reasoning.We present a model for referring expressions comprehension by selecting the most relevant region directly from the image.The core of our model is a recurrent attention network which can be seen as an extension of Memory Network.The proposed model capable of improving the results by multiple computational hops.We evaluate the proposed model on two referring expression datasets:Visual Genome and Flickr30k Entities.The experimental results demonstrate that the proposed model outperform previous state-of-the-art methods both in accuracy and efficiency.We also conduct an ablation experiment to show that the performance of the model is not getting better with the increase of the attention layers.展开更多
Based on a review of the theories on meaning in the field of philosophy, semantics and pragmatics, this paper suggests that language meaning, subject to constant change in real communication,is a concept different fro...Based on a review of the theories on meaning in the field of philosophy, semantics and pragmatics, this paper suggests that language meaning, subject to constant change in real communication,is a concept different from relatively static sense and reference which are mutual inter-dependent to each other. Sense and reference constitute the personal images of any given words.Three sources of meaning are elaborated: the dictionary sense, the personal images of any given words, and the dynamic context.A combination of traditional semantic meaning and dynamic pragmatic meaning analysis is suggested through examining the meaning derivation process in the cases of the use of referring expressions in definite, indefinite descriptions, and incomplete sentences.展开更多
In referring segmentation,modeling the complicated constraints in the multimodal information is one of the most challenging problems.As the information in a given language expression and image becomes increasingly abu...In referring segmentation,modeling the complicated constraints in the multimodal information is one of the most challenging problems.As the information in a given language expression and image becomes increasingly abundant,most of the current one-stage methods that directly output the segmentation mask encounter difficulties in understanding the complicated relationships between the image and the expression.In this work,we propose a PrimitiveNet to decompose the difficult global constraints into a set of simple primitives.Each primitive produces a primitive mask that represents only simple semantic meanings,e.g.,all instances from the same category.Then,the output segmentation mask is computed by selectively combining these primitives according to the language expression.Furthermore,we propose a cross-primitive attention(CPA)module and a language-primitive attention(LPA)module to exchange information among all primitives and the language expression,respectively.The proposed CPA and LPA help the network find appropriate weights for primitive masks,so as to recover the target object.Extensive experiments have proven the effectiveness of our design and verified that the proposed network outperforms current state-of-the-art referring segmentation methods on three RefCOCO datasets.展开更多
This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signa...This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning accuracy.Managed by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude regions.Ina-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast Asia.We provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this network.We generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific research.Two preliminary findings from the ROTI maps of Ina-CORS are noteworthy.First,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther eastward.Second,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East Asia.We have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,2024.We observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities post-midnight.By sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionospheric research.展开更多
This paper introduces a high-precision bandgap reference(BGR)designed for battery management systems(BMS),fea-turing an ultra-low temperature coefficient(TC)and line sensitivity(LS).The BGR employs a current-mode sche...This paper introduces a high-precision bandgap reference(BGR)designed for battery management systems(BMS),fea-turing an ultra-low temperature coefficient(TC)and line sensitivity(LS).The BGR employs a current-mode scheme with chopped op-amps and internal clock generators to eliminate op-amp offset.A low dropout regulator(LDO)and a pre-regula-tor enhance output driving and LS,respectively.Curvature compensation enhances the TC by addressing higher-order nonlinear-ity.These approaches,effective near room temperature,employs trimming at both 20 and 60°C.When combined with fixed cur-vature correction currents,it achieves an ultra-low TC for each chip.Implemented in a CMOS 180 nm process,the BGR occu-pies 0.548 mm²and operates at 2.5 V with 84μA current draw from a 5 V supply.An average TC of 2.69 ppm/℃ with two-point trimming and 0.81 ppm/℃ with multi-point trimming are achieved over the temperature range of-40 to 125℃.It accommo-dates a load current of 1 mA and an LS of 42 ppm/V,making it suitable for precise BMS applications.展开更多
The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within ...The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within the field of computerized ionospheric tomography(CIT)to facilitate three-dimensional reconstruction of the ionospheric morphology.However,reconstruction accuracy elicits recurrent disputes over its practical application,and people usually attribute this issue to incomplete and uneven coverage of the measurements.The Thermosphere Ionosphere Electrodynamics General Circulation Model(TIEGCM)offers a reasonable physics-based ionospheric background and is widely utilized in ionospheric research.We use the TIEGCM simulations as the targeted ionosphere because the current measurements are far from able to realistically reproduce the ionosphere in detail.Optimized designations of satellite measurements are conducted to investigate the limiting performance of CIT methods in ionospheric reconstruction.Similar to common practice,electron density distributions from outputs of the International Reference Ionosphere(IRI)model are used as the iterative initial value in CIT applications.The outcomes suggest that despite data coverage,iterative initial conditions also play an essential role in ionospheric reconstruction.In particular,in the longitudinal sectors where the iterative initial height of the F2-layer peak electron density(hmF2)differs substantially from the background densities,none of the three CIT methods can reproduce the exact background profile.When hmF2 is close but the ionospheric F2-layer peak density(NmF2)is different between the targeted background and initial conditions,the MART performs better than the ART and SIRT,as evidenced by the correlation coefficients of MART being above 0.97 and those of ART and SIRT being below 0.85.In summary,this investigation reveals the potential uncertainties in traditional CIT reconstruction,particularly when realistic hmF2 or NmF2 values differ substantially from the initial CIT conditions.展开更多
Talking about and referring to others is a fundamentally human activity that relies on the meaningful use of referring expressions for interlocuters to be able to identify the specific individual( s) being spoken of. ...Talking about and referring to others is a fundamentally human activity that relies on the meaningful use of referring expressions for interlocuters to be able to identify the specific individual( s) being spoken of. With a primary focus on practices for referring to third parties,the broad aim of this paper is to show that whilst the selection of referring expression is based on complex,deeply social and cultural conventions,it is also a highly systematic and orderly activity. More specifically,this paper explores an interactional 'puzzle' contained in a single piece of data,in which a daughter — in conversation with her mother — refers to her father( her mother's ex-husband) in three different ways in quick succession. In doing so,we illustrate the potential interactional import of referring expressions for accomplishing social action beyond indexing an individual. In analysing this single case,one procedure for doing conversation analytic work is also illustrated. That is,in contrast to building and analysing collections,this paper draws on and applies what is already known from previous conversation analytic literature about practices for referring to persons. In analysing one fragment in which reference to a third party is made,we will review the fundamentals of the organisation of person reference in English.展开更多
BACKGROUND Pepsinogen(PG)and the PG I/II ratio(PGR)are critical indicators for diagnosing Helicobacter pylori infection and chronic atrophic gastritis,and assessing gastric cancer risk.Existing reference intervals(RIs...BACKGROUND Pepsinogen(PG)and the PG I/II ratio(PGR)are critical indicators for diagnosing Helicobacter pylori infection and chronic atrophic gastritis,and assessing gastric cancer risk.Existing reference intervals(RIs)often overlook age,sex,and demographic variations.Partitioned RIs,while considering these factors,fail to capture the gradual age-related physiological changes.Next-generation RIs offer a solution to this limitation.AIM To investigate age-and sex-specific dynamics of PG and establish next-generation RIs for adults and the elderly in northern China.METHODS After screening,708 healthy individuals were included in this observational study.Serum PG was measured using chemiluminescence immunoassay.Age-and sex-related effects on PG were analyzed with a two-way analysis of variance.RI partitioning was determined by the standard deviation ratio(SDR).Traditional RIs were established using a non-parametric approach.Generalized Additive Models for Location,Scale,and Shape(GAMLSS)modeled age-related trends and continuous reference percentiles for PG I and PG II.Reference limit flagging rates for both RI types were compared.RESULTS PG I and PG II levels were influenced by age(P<0.001)and sex(P<0.001),while PGR remained stable.Age-specific RIs were required for PG I(SDR=0.366)and PG II(SDR=0.424).Partitioned RIs were established for PG I and PG II,with a single RI for PGR.GAMLSS modeling revealed distinct age-dependent trajectories:PG I increased from a median of 39.75μg/L at age 20 years to 49.75μg/L at age 60 years,a 25.16%increase,after which it plateaued through age 80 years.In contrast,PG II showed a continuous rise throughout the age range,with the median value increasing from 5.07μg/L at age 20 years to 8.36μg/L at age 80 years,corresponding to a 64.89%increase.Continuous reference percentiles intuitively reflected these trends and were detailed in this study.Next-generation RIs demonstrated superior accuracy compared to partitioned RIs when applied to specific age subgroups.CONCLUSION This study elucidates the age-and sex-specific dynamics of PG and,to our knowledge,is the first to establish next-generation RIs for PG,supporting more individualized interpretation in laboratory medicine.展开更多
Reference Evapotranspiration(ETo)iswidely used to assess totalwater loss between land and atmosphere due to its importance in maintaining the atmospheric water balance,especially in agricultural and environmental mana...Reference Evapotranspiration(ETo)iswidely used to assess totalwater loss between land and atmosphere due to its importance in maintaining the atmospheric water balance,especially in agricultural and environmental management.Accurate estimation of ETo is challenging due to its dependency onmultiple climatic variables,including temperature,humidity,and solar radiation,making it a complexmultivariate time-series problem.Traditional machine learning and deep learning models have been applied to forecast ETo,achieving moderate success.However,the introduction of transformer-based architectures in time-series forecasting has opened new possibilities formore precise ETo predictions.In this study,a novel algorithm for ETo forecasting is proposed,focusing on four transformer-based models:Vanilla Transformer,Informer,Autoformer,and FEDformer(Frequency Enhanced Decomposed Transformer),applied to an ETo dataset from the Andalusian region.The novelty of the proposed algorithm lies in determining optimized window sizes based on seasonal trends and variations,which were then used with each model to enhance prediction accuracy.This custom window-sizing method allows the models to capture ETo’s unique seasonal patterns more effectively.Finally,results demonstrate that the Informer model outperformed other transformer-based models,achievingmean square error(MSE)values of 0.1404 and 0.1445 for forecast windows(15,7)and(30,15),respectively.The Vanilla Transformer also showed strong performance,closely following the Informermodel.These findings suggest that the proposed optimized window-sizing approach,combined with transformer-based architectures,is highly effective for ETo modelling.This novel strategy has the potential to be adapted in othermultivariate time-series forecasting tasks that require seasonality-sensitive approaches.展开更多
Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences,especially in ore deposits where sulfide-sulfate pair coprecipitates widely.However,...Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences,especially in ore deposits where sulfide-sulfate pair coprecipitates widely.However,in-situ S isotope determination of barite is challenging without natural matrix-matched reference material.In this study,we present two natural barite reference materials(1-YS and 294-YS)for in-situ sulfur isotopic analysis.Independent LA-MC-ICP-MS laboratories were utilized to test theδ34S micron-scale homogeneity of 1-YS and 294-YS barites that have 2s repeatabilities of better than±0.45‰and±0.41‰,respectively.Meanwhile,the in-situ analysis results are consistent with the results of the bulk analysis by GS-IRMS within uncertainty.The grand meanδ~(34)S values of 1-YS(13.37‰±0.42‰,2s)and 294-YS(14.38‰±0.44‰,2s)are the final recommended values obtained from four independent laboratories.All the results confirm the suitability of 1-YS and 294-YS barite used as calibration materials with respect to in-situ S isotopic analysis.Moreover,the new developed barite reference materials were used as matrix-matched standard to calibrate the barite samples from the Huayangchuan carbonatite-hosted U-polymetallic deposit(Qinling orogenic belt,western China)to obtainδ34S values.Utilizing the temperaturedependentδ34S fractionation of barite-pyrite pair,we calculate the formation temperature of barite(i.e.,506 to 537°C)and theδ34S value of mineralizing fluid(i.e.,-7.11‰to-7.59‰)in the Huayangchuan deposit.The results indicate an involvement of sedimentary sulfur,presumably acting as a potential uranium source(e.g.,upper crustal materials)for the giant Huayangchuan deposit.展开更多
Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce th...Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce the uncertainty of radiative forcing estimation and source apportionment.The accurate separation of OC and EC is controversial due to the charring of OC.Therefore,the development of reference materials(RM)for the validation of OC/EC separation is an important basis for further study.Previous RMs were mainly based on ambient air sampling,which could not provide traceability of OC and EC concentration.To develop traceable RMs with known OC/EC contents,our study applied an improved aerosol generation and mixing technique,providing uniform deposition of particles on quartz filters.To generate OC aerosol with similar pyrolytic property of ambient aerosol,both water soluble organic carbon(WSOC)and water insoluble organic carbon(WIOC)were used,and amorphous carbon was selected for EC surrogate.The RMs were analyzed using different protocols.The homogeneity within the filter was validated,reaching below 2%.The long-term stability of RMs has been validated with RSD ranged from 1.7%–3.2%.Good correlationwas observed between nominal concentration of RMswithmeasured concentration by two protocols,while the difference of EC concentration was within 20%.The results indicated that the newly developed RMs were acceptable for the calibration of OC and EC,which could improve the accuracy of carbonaceous aerosol measurement.Moreover,the laboratory-generated EC-RMs could be suitable for the calibration of equivalent BC concentration by Aethalometers.展开更多
Bamboo was one of the first plants to be cultivated in China and is widely used in industry and daily life.The study of gene function has become an important part of bamboo breeding,whereas quantitative real-time PCR(...Bamboo was one of the first plants to be cultivated in China and is widely used in industry and daily life.The study of gene function has become an important part of bamboo breeding,whereas quantitative real-time PCR(qRT-PCR)is a powerful tool for gene expression analysis.The accuracy of qRT-PCR results largely depends on suitable reference genes.In this study,a transcriptome-wide identification of reference genes was conducted based on 447 transcriptome datasets,comprising 200 tissue samples,107 treated samples,and 140 samples from various moso bamboo(Phyllostachys edulis)forms.A total of 3444,1013,and 3962 stably expressed genes were identified from these three groups,respectively.Functional enrichment analysis revealed significant enrichment of these genes in pathways,including the spliceosome,proteasome,and oxidative phosphorylation.Eight candidate genes(ADPRE,GAPDH,TRX,TUBA,NRP,MBF,UNK,and CAM1),were selected for qRT-PCR validation using 112 samples.To assess their stability,five statistical methods(geNorm,NormFinder,BestKeeper,Delta-Ct,and RefFinder)were employed.The most suitable reference genes were ADPRE and GAPDH for different tissues,GAPDH and CAM1 for different treatments,and GAPDH and TRX for various moso bamboo forms.Overall,ADPRE and GAPDH were the most stable reference genes across all conditions,while TUBA and TRX were the least stable reference genes.In addition,a significant negative correlation was found between the Ct values of RT-qPCR and the log2TPM values from the transcriptome data(Ct=-1.534x+37.221),providing a potential method for estimating gene expression levels.The identified reference genes,particularly ADPRE and GAPDH,provide a robust set of references for gene expression studies in moso bamboo.展开更多
This brief presents a cryogenic voltage reference circuit designed to operate effectively across a wide temperature range from 30 to 300 K.A key feature of the proposed design is utilizing a current subtraction techni...This brief presents a cryogenic voltage reference circuit designed to operate effectively across a wide temperature range from 30 to 300 K.A key feature of the proposed design is utilizing a current subtraction technique for temperature compensation of the reference current,avoiding the deployment of bipolar transistors to reduce area and power consumption.Implemented with a 0.18-μm CMOS process,the circuit achieves a temperature coefficient(TC)of 67.5 ppm/K,which was not achieved in previous works.The design can also attain a power supply rejection(PSR)of 58 d B at 10 k Hz.Meanwhile,the average reference voltage is 1.2 V within a 1.6%3σ-accuracy spread.Additionally,the design is characterized by a minimal power dissipation of 1μW at 30 K and a compact chip area of 0.0035 mm~2.展开更多
To solve the problem of the lack of reference material(RM)for determination of allergenic ingredients in food,a RM of cashew nut powder was developed in the study.Cashew nut powder was prepared from cashew nut kernel ...To solve the problem of the lack of reference material(RM)for determination of allergenic ingredients in food,a RM of cashew nut powder was developed in the study.Cashew nut powder was prepared from cashew nut kernel by selecting,cleaning,crushing,n-hexane degreasing and sieving treatment.The reliability and traceability of RM was verified using real-time quantitative polymerase chain reaction(qPCR)and phylogenetic tree analysis.The cashew nut powder RM showed good homogeneity,and good stability under long-term storage at 4℃and short-term simulated transportation from-20 to 45℃.The RM was determined jointly by 8 collaborative laboratories,and the characteristic CT value was 24.732,and the extended uncertainty was 1.052%(k=2).The RM was applied to verify the amplification efficiency and the limit of detection for qPCR assay,and showed good applicability.The RM could be used for method validation and quality control,for the determination of allergenic ingredients in food mixed with trace amounts of cashew nut.展开更多
Highly accurate international height reference frames with long-term stability,global consistency,and homogeneity are crucial for monitoring sea level variations,understanding climate change,managing disasters,and sup...Highly accurate international height reference frames with long-term stability,global consistency,and homogeneity are crucial for monitoring sea level variations,understanding climate change,managing disasters,and supporting other applications that benefit scientific research and societal well-being.Currently,there are over 100 local height reference systems worldwide.Unifying these systems is a pivotal step toward constructing international height reference frames.The method introduced in this study-the gravity frequency shift via Satellite Frequency Signal Transfer(SFST)-represents a groundbreaking relativistic geodetic approach,demonstrating its potential to surpass the constraints of conventional techniques.The advent of high-precision optical atomic clocks(OAC)with an accuracy level of 1×10^(-18) has facilitated this method's implementation.The International Association of Geodesy(IAG)has established the International Height Reference System(IHRS)and its practical realization,the International Height Reference Frame(IHRF).Our study focuses on two neighbouring height systems:the China Height System(CHS)and the Nepal Height System(NHS),separated by the Himalayas and the Xizang plateau.We aim to unify these two systems by determining the geopotential and orthometric height differences between their respective height datum stations:the Qingdao Height Datum Station(QHDS)and the Madar Height Datum Station(MHDS)using a simulation experiment with the method mentioned above.Using an OAC with an accuracy of 1×10^(-18),we identified a geopotential difference of-8.348±0.464 m^(2)s^(-2) and an orthometric height difference of 0.786±0.047 m between QHDS and MHDS.These results suggest that the introduced method could unify any two height systems with fewcentimeter-level precision,emphasizing its significance in contributing to the construction of the IHRS/IHRF with today's required precision.In summary,the SFST technique is a novel geodetic method that offers an alternative for height system unification,delivering centimeter-level precision,surpassing traditional methods,and supporting the development of the IHRF.展开更多
基金funded by the National Natural Science Foundation of China(No.62076032).
文摘Referring expression comprehension(REC)aims to locate a specific region in an image described by a natural language.Existing two-stage methods generate multiple candidate proposals in the first stage,followed by selecting one of these proposals as the grounding result in the second stage.Nevertheless,the number of candidate proposals generated in the first stage significantly exceeds ground truth and the recall of critical objects is inadequate,thereby enormously limiting the overall network performance.To address the above issues,the authors propose an innovative method termed Separate Non-Maximum Suppression(Sep-NMS)for two-stage REC.Particularly,Sep-NMS models information from the two stages independently and collaboratively,ultimately achieving an overall improvement in comprehension and identification of the target objects.Specifically,the authors propose a Ref-Relatedness module for filtering referent proposals rigorously,decreasing the redundancy of referent proposals.A CLIP†Relatedness module based on robust multimodal pre-trained encoders is built to precisely assess the relevance between language and proposals to improve the recall of critical objects.It is worth mentioning that the authors are the pioneers in utilising a multimodal pre-training model for proposal filtering in the first stage.Moreover,an Information Fusion module is designed to effectively amalgamate the multimodal information across two stages,ensuring maximum uti-lisation of the available information.Extensive experiments demonstrate that the approach achieves competitive performance with previous state-of-the-art methods.The datasets used are publicly available:RefCOCO,RefCOCO+:https://doi.org/10.1007/978-3-319-46475-6_5 and RefCOCOg:https://doi.org/10.1109/CVPR.2016.9.
基金supported by the National Natural Science Foundation of China(Nos.62063009,52262050)the National Key Research and Development Program during the 14th 5-Year Plan(No.2023YFB4302100)the Major Science and Technology Research and Development Special Project in Jiangxi Province(No.20232ACE01011).
文摘To address the issue of disturbance compensation deviation in linear active disturbance rejection control(LADRC),a linear active disturbance rejection control method with reference to the integral chain model(LADRC-R)is proposed.By constructing an ideal control reference model,a dynamic correlation between output deviation and uncompensated disturbances is established,and a dual-loop compensation mechanism is designed.Based on theoretical analysis and frequency-domain characteristics of typical first/second-order systems,this method maintains the parameter-tuning advantages of LADRC while reducing disturbance effects by 50%and introducing no phase lag during low-frequency disturbance suppression.Simulations on second-order systems verify its robustness under parameter perturbations,gain mismatch,and complex disturbances,and an optimized design scheme for the deviation compensator is proposed to suppress discontinuous measurement noise interference.Finally,the engineering effectiveness of this method in precision motion control is validated on an electromagnetic suspension platform,providing a new approach to improving the control performance of LADRC in environments with uncertain disturbances.
文摘Background: Justification is the process of weighing the potential benefit of the exposure against potential detriment for that individual. Its role has been largely delegated to imaging professionals. Nevertheless, justification process involves referring physicians, radiographers and radiologists. Objective: To assess the knowledge of referring physicians regarding justification of irradiating examinations in medical imaging at the university-affiliated hospitals in Yaoundé Cameroon. Materials and Methods: A questionnaire (18 questions) based on the French guide for the proper use of medical imaging tests in relation to the justification of irradiating examinations, was self-administered to 151 referring physicians in Yaounde (Cameroon) between October 2012 and January 2013. The pre-tested questionnaire was completed in the presence of the investigator. A scoring system was then adopted with a total of 15 points from the level of knowledge on justification which could be classified as satisfactory or not. Results: Referring physicians were 75 (49.7%) GPs, 53 (35.1%) residents and 23 (15.2%) specialists. Knowledge on justification was unsatisfactory for 79.5% of referring physicians with no significant difference in terms of professional experience (p = 0.95) or specialty (p = 0.119). The concepts of “useful exam” and “justified exam” were not known by 113 (74.8%) and 95 (62.9%) practitioners. MRI was selected as irradiating by 62 (41.1%), SPECT and PET-scan as non-radiating examinations by 98 (64.9%) and 115 (76.1%) participants. The main reasons for repeating a giving radiology exam were: unsatisfactory interpretation, unknown of where it was performing and poor quality exam respectively for 23 (15.2%), 37 (24.5%) and 43 (28.5%) referring physicians. Justification was the responsibility of the referring physician alone for 57% of respondent. Only 11 clinicians knew the reference of “Justification-Optimization-Limitation” to radiation protection. Conclusion: The knowledge of physicians on radiating medical procedures and justification of requests for these procedures is inadequate. Training in radiation protection and the introduction of guidelines for the proper use of imaging tests could improve physicians’ justification of radiating examinations.
基金This work was supported in part by audio-visual new media laboratory operation and maintenance of Academy of Broadcasting Science,Grant No.200304in part by the National Key Research and Development Program of China(Grant No.2019YFB1406201).
文摘Referring expressions comprehension is the task of locating the image region described by a natural language expression,which refer to the properties of the region or the relationships with other regions.Most previous work handles this problem by selecting the most relevant regions from a set of candidate regions,when there are many candidate regions in the set these methods are inefficient.Inspired by recent success of image captioning by using deep learning methods,in this paper we proposed a framework to understand the referring expressions by multiple steps of reasoning.We present a model for referring expressions comprehension by selecting the most relevant region directly from the image.The core of our model is a recurrent attention network which can be seen as an extension of Memory Network.The proposed model capable of improving the results by multiple computational hops.We evaluate the proposed model on two referring expression datasets:Visual Genome and Flickr30k Entities.The experimental results demonstrate that the proposed model outperform previous state-of-the-art methods both in accuracy and efficiency.We also conduct an ablation experiment to show that the performance of the model is not getting better with the increase of the attention layers.
文摘Based on a review of the theories on meaning in the field of philosophy, semantics and pragmatics, this paper suggests that language meaning, subject to constant change in real communication,is a concept different from relatively static sense and reference which are mutual inter-dependent to each other. Sense and reference constitute the personal images of any given words.Three sources of meaning are elaborated: the dictionary sense, the personal images of any given words, and the dynamic context.A combination of traditional semantic meaning and dynamic pragmatic meaning analysis is suggested through examining the meaning derivation process in the cases of the use of referring expressions in definite, indefinite descriptions, and incomplete sentences.
基金partially supported by the research grant of NTU Presidential Postdoctoral Fellowship.
文摘In referring segmentation,modeling the complicated constraints in the multimodal information is one of the most challenging problems.As the information in a given language expression and image becomes increasingly abundant,most of the current one-stage methods that directly output the segmentation mask encounter difficulties in understanding the complicated relationships between the image and the expression.In this work,we propose a PrimitiveNet to decompose the difficult global constraints into a set of simple primitives.Each primitive produces a primitive mask that represents only simple semantic meanings,e.g.,all instances from the same category.Then,the output segmentation mask is computed by selectively combining these primitives according to the language expression.Furthermore,we propose a cross-primitive attention(CPA)module and a language-primitive attention(LPA)module to exchange information among all primitives and the language expression,respectively.The proposed CPA and LPA help the network find appropriate weights for primitive masks,so as to recover the target object.Extensive experiments have proven the effectiveness of our design and verified that the proposed network outperforms current state-of-the-art referring segmentation methods on three RefCOCO datasets.
基金JSPS KAKENHI Grant Number16H06286 supports global GNSS ionospheric maps (TEC,ROTI,and detrended TEC maps) developed by the Institute for SpaceEarth Environmental Research (ISEE) of Nagoya Universitysupport of the 2024 JASSO Follow-up Research Fellowship Program for a 90-day visiting research at the Institute for Space-Earth Environmental Research (ISEE),Nagoya University+3 种基金the support received from Telkom University under the“Skema Penelitian Terapan Periode I Tahun Anggaran 2024”the Memorandum of Understanding for Research Collaboration on Regional Ionospheric Observation (No:092/SAM3/TE-DEK/2021)the National Institute of Information and Communications Technology (NICT) International Exchange Program 2024-2025(No.2024-007)support for a one-year visiting research at Hokkaido University
文摘This paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning accuracy.Managed by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude regions.Ina-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast Asia.We provide a practical tool for EPB research,by sharing two-dimensional rate of Total Electron Content(TEC)change index(ROTI)derived from this network.We generate ROTI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific research.Two preliminary findings from the ROTI maps of Ina-CORS are noteworthy.First,the Ina-CORS ROTI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther eastward.Second,we demonstrate that combined ROTI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East Asia.We have demonstrated the combined ROTI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,2024.We observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities post-midnight.By sharing ROTI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionospheric research.
基金supported by the National Natural Science Foundation of China(NSFC)under grant No.62204235。
文摘This paper introduces a high-precision bandgap reference(BGR)designed for battery management systems(BMS),fea-turing an ultra-low temperature coefficient(TC)and line sensitivity(LS).The BGR employs a current-mode scheme with chopped op-amps and internal clock generators to eliminate op-amp offset.A low dropout regulator(LDO)and a pre-regula-tor enhance output driving and LS,respectively.Curvature compensation enhances the TC by addressing higher-order nonlinear-ity.These approaches,effective near room temperature,employs trimming at both 20 and 60°C.When combined with fixed cur-vature correction currents,it achieves an ultra-low TC for each chip.Implemented in a CMOS 180 nm process,the BGR occu-pies 0.548 mm²and operates at 2.5 V with 84μA current draw from a 5 V supply.An average TC of 2.69 ppm/℃ with two-point trimming and 0.81 ppm/℃ with multi-point trimming are achieved over the temperature range of-40 to 125℃.It accommo-dates a load current of 1 mA and an LS of 42 ppm/V,making it suitable for precise BMS applications.
基金supported by the National Key R&D Program of China (Grant No. 2022YFF0503702)the National Natural Science Foundation of China (Grant No. 42074186)
文摘The algebraic reconstruction technique(ART),multiplicative algebraic reconstruction technique(MART),and simultaneous iterative reconstruction technique(SIRT)are computational methodologies extensively utilized within the field of computerized ionospheric tomography(CIT)to facilitate three-dimensional reconstruction of the ionospheric morphology.However,reconstruction accuracy elicits recurrent disputes over its practical application,and people usually attribute this issue to incomplete and uneven coverage of the measurements.The Thermosphere Ionosphere Electrodynamics General Circulation Model(TIEGCM)offers a reasonable physics-based ionospheric background and is widely utilized in ionospheric research.We use the TIEGCM simulations as the targeted ionosphere because the current measurements are far from able to realistically reproduce the ionosphere in detail.Optimized designations of satellite measurements are conducted to investigate the limiting performance of CIT methods in ionospheric reconstruction.Similar to common practice,electron density distributions from outputs of the International Reference Ionosphere(IRI)model are used as the iterative initial value in CIT applications.The outcomes suggest that despite data coverage,iterative initial conditions also play an essential role in ionospheric reconstruction.In particular,in the longitudinal sectors where the iterative initial height of the F2-layer peak electron density(hmF2)differs substantially from the background densities,none of the three CIT methods can reproduce the exact background profile.When hmF2 is close but the ionospheric F2-layer peak density(NmF2)is different between the targeted background and initial conditions,the MART performs better than the ART and SIRT,as evidenced by the correlation coefficients of MART being above 0.97 and those of ART and SIRT being below 0.85.In summary,this investigation reveals the potential uncertainties in traditional CIT reconstruction,particularly when realistic hmF2 or NmF2 values differ substantially from the initial CIT conditions.
文摘Talking about and referring to others is a fundamentally human activity that relies on the meaningful use of referring expressions for interlocuters to be able to identify the specific individual( s) being spoken of. With a primary focus on practices for referring to third parties,the broad aim of this paper is to show that whilst the selection of referring expression is based on complex,deeply social and cultural conventions,it is also a highly systematic and orderly activity. More specifically,this paper explores an interactional 'puzzle' contained in a single piece of data,in which a daughter — in conversation with her mother — refers to her father( her mother's ex-husband) in three different ways in quick succession. In doing so,we illustrate the potential interactional import of referring expressions for accomplishing social action beyond indexing an individual. In analysing this single case,one procedure for doing conversation analytic work is also illustrated. That is,in contrast to building and analysing collections,this paper draws on and applies what is already known from previous conversation analytic literature about practices for referring to persons. In analysing one fragment in which reference to a third party is made,we will review the fundamentals of the organisation of person reference in English.
文摘BACKGROUND Pepsinogen(PG)and the PG I/II ratio(PGR)are critical indicators for diagnosing Helicobacter pylori infection and chronic atrophic gastritis,and assessing gastric cancer risk.Existing reference intervals(RIs)often overlook age,sex,and demographic variations.Partitioned RIs,while considering these factors,fail to capture the gradual age-related physiological changes.Next-generation RIs offer a solution to this limitation.AIM To investigate age-and sex-specific dynamics of PG and establish next-generation RIs for adults and the elderly in northern China.METHODS After screening,708 healthy individuals were included in this observational study.Serum PG was measured using chemiluminescence immunoassay.Age-and sex-related effects on PG were analyzed with a two-way analysis of variance.RI partitioning was determined by the standard deviation ratio(SDR).Traditional RIs were established using a non-parametric approach.Generalized Additive Models for Location,Scale,and Shape(GAMLSS)modeled age-related trends and continuous reference percentiles for PG I and PG II.Reference limit flagging rates for both RI types were compared.RESULTS PG I and PG II levels were influenced by age(P<0.001)and sex(P<0.001),while PGR remained stable.Age-specific RIs were required for PG I(SDR=0.366)and PG II(SDR=0.424).Partitioned RIs were established for PG I and PG II,with a single RI for PGR.GAMLSS modeling revealed distinct age-dependent trajectories:PG I increased from a median of 39.75μg/L at age 20 years to 49.75μg/L at age 60 years,a 25.16%increase,after which it plateaued through age 80 years.In contrast,PG II showed a continuous rise throughout the age range,with the median value increasing from 5.07μg/L at age 20 years to 8.36μg/L at age 80 years,corresponding to a 64.89%increase.Continuous reference percentiles intuitively reflected these trends and were detailed in this study.Next-generation RIs demonstrated superior accuracy compared to partitioned RIs when applied to specific age subgroups.CONCLUSION This study elucidates the age-and sex-specific dynamics of PG and,to our knowledge,is the first to establish next-generation RIs for PG,supporting more individualized interpretation in laboratory medicine.
基金funded by Princess Nourah bint Abdulrahman University and Researchers Supporting Project number(PNURSP2024R136),Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia.
文摘Reference Evapotranspiration(ETo)iswidely used to assess totalwater loss between land and atmosphere due to its importance in maintaining the atmospheric water balance,especially in agricultural and environmental management.Accurate estimation of ETo is challenging due to its dependency onmultiple climatic variables,including temperature,humidity,and solar radiation,making it a complexmultivariate time-series problem.Traditional machine learning and deep learning models have been applied to forecast ETo,achieving moderate success.However,the introduction of transformer-based architectures in time-series forecasting has opened new possibilities formore precise ETo predictions.In this study,a novel algorithm for ETo forecasting is proposed,focusing on four transformer-based models:Vanilla Transformer,Informer,Autoformer,and FEDformer(Frequency Enhanced Decomposed Transformer),applied to an ETo dataset from the Andalusian region.The novelty of the proposed algorithm lies in determining optimized window sizes based on seasonal trends and variations,which were then used with each model to enhance prediction accuracy.This custom window-sizing method allows the models to capture ETo’s unique seasonal patterns more effectively.Finally,results demonstrate that the Informer model outperformed other transformer-based models,achievingmean square error(MSE)values of 0.1404 and 0.1445 for forecast windows(15,7)and(30,15),respectively.The Vanilla Transformer also showed strong performance,closely following the Informermodel.These findings suggest that the proposed optimized window-sizing approach,combined with transformer-based architectures,is highly effective for ETo modelling.This novel strategy has the potential to be adapted in othermultivariate time-series forecasting tasks that require seasonality-sensitive approaches.
基金supported by the National Natural Science Foundation of China(Nos.42003014,42363004,42073051,42303023)Jiangxi Provincial Natural Science Foundation(No.20232BAB213070)the Natural Science Foundation of Shandong Province(No.ZR2022QD050)。
文摘Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences,especially in ore deposits where sulfide-sulfate pair coprecipitates widely.However,in-situ S isotope determination of barite is challenging without natural matrix-matched reference material.In this study,we present two natural barite reference materials(1-YS and 294-YS)for in-situ sulfur isotopic analysis.Independent LA-MC-ICP-MS laboratories were utilized to test theδ34S micron-scale homogeneity of 1-YS and 294-YS barites that have 2s repeatabilities of better than±0.45‰and±0.41‰,respectively.Meanwhile,the in-situ analysis results are consistent with the results of the bulk analysis by GS-IRMS within uncertainty.The grand meanδ~(34)S values of 1-YS(13.37‰±0.42‰,2s)and 294-YS(14.38‰±0.44‰,2s)are the final recommended values obtained from four independent laboratories.All the results confirm the suitability of 1-YS and 294-YS barite used as calibration materials with respect to in-situ S isotopic analysis.Moreover,the new developed barite reference materials were used as matrix-matched standard to calibrate the barite samples from the Huayangchuan carbonatite-hosted U-polymetallic deposit(Qinling orogenic belt,western China)to obtainδ34S values.Utilizing the temperaturedependentδ34S fractionation of barite-pyrite pair,we calculate the formation temperature of barite(i.e.,506 to 537°C)and theδ34S value of mineralizing fluid(i.e.,-7.11‰to-7.59‰)in the Huayangchuan deposit.The results indicate an involvement of sedimentary sulfur,presumably acting as a potential uranium source(e.g.,upper crustal materials)for the giant Huayangchuan deposit.
基金supported by the National Natural Science Foundation of China(No.22206180)the funds for establishing basic quality and technology capabilities(No.ANL2203)the special fund for basic scientific research business of central public research institutes(No.AKYZD2207-4)。
文摘Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce the uncertainty of radiative forcing estimation and source apportionment.The accurate separation of OC and EC is controversial due to the charring of OC.Therefore,the development of reference materials(RM)for the validation of OC/EC separation is an important basis for further study.Previous RMs were mainly based on ambient air sampling,which could not provide traceability of OC and EC concentration.To develop traceable RMs with known OC/EC contents,our study applied an improved aerosol generation and mixing technique,providing uniform deposition of particles on quartz filters.To generate OC aerosol with similar pyrolytic property of ambient aerosol,both water soluble organic carbon(WSOC)and water insoluble organic carbon(WIOC)were used,and amorphous carbon was selected for EC surrogate.The RMs were analyzed using different protocols.The homogeneity within the filter was validated,reaching below 2%.The long-term stability of RMs has been validated with RSD ranged from 1.7%–3.2%.Good correlationwas observed between nominal concentration of RMswithmeasured concentration by two protocols,while the difference of EC concentration was within 20%.The results indicated that the newly developed RMs were acceptable for the calibration of OC and EC,which could improve the accuracy of carbonaceous aerosol measurement.Moreover,the laboratory-generated EC-RMs could be suitable for the calibration of equivalent BC concentration by Aethalometers.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFD2200502)the National Natural Science Foundation of China(Grant No.31971736).
文摘Bamboo was one of the first plants to be cultivated in China and is widely used in industry and daily life.The study of gene function has become an important part of bamboo breeding,whereas quantitative real-time PCR(qRT-PCR)is a powerful tool for gene expression analysis.The accuracy of qRT-PCR results largely depends on suitable reference genes.In this study,a transcriptome-wide identification of reference genes was conducted based on 447 transcriptome datasets,comprising 200 tissue samples,107 treated samples,and 140 samples from various moso bamboo(Phyllostachys edulis)forms.A total of 3444,1013,and 3962 stably expressed genes were identified from these three groups,respectively.Functional enrichment analysis revealed significant enrichment of these genes in pathways,including the spliceosome,proteasome,and oxidative phosphorylation.Eight candidate genes(ADPRE,GAPDH,TRX,TUBA,NRP,MBF,UNK,and CAM1),were selected for qRT-PCR validation using 112 samples.To assess their stability,five statistical methods(geNorm,NormFinder,BestKeeper,Delta-Ct,and RefFinder)were employed.The most suitable reference genes were ADPRE and GAPDH for different tissues,GAPDH and CAM1 for different treatments,and GAPDH and TRX for various moso bamboo forms.Overall,ADPRE and GAPDH were the most stable reference genes across all conditions,while TUBA and TRX were the least stable reference genes.In addition,a significant negative correlation was found between the Ct values of RT-qPCR and the log2TPM values from the transcriptome data(Ct=-1.534x+37.221),providing a potential method for estimating gene expression levels.The identified reference genes,particularly ADPRE and GAPDH,provide a robust set of references for gene expression studies in moso bamboo.
基金supported in part by the National Key Research and Development Program of China(2021YFA0715503)。
文摘This brief presents a cryogenic voltage reference circuit designed to operate effectively across a wide temperature range from 30 to 300 K.A key feature of the proposed design is utilizing a current subtraction technique for temperature compensation of the reference current,avoiding the deployment of bipolar transistors to reduce area and power consumption.Implemented with a 0.18-μm CMOS process,the circuit achieves a temperature coefficient(TC)of 67.5 ppm/K,which was not achieved in previous works.The design can also attain a power supply rejection(PSR)of 58 d B at 10 k Hz.Meanwhile,the average reference voltage is 1.2 V within a 1.6%3σ-accuracy spread.Additionally,the design is characterized by a minimal power dissipation of 1μW at 30 K and a compact chip area of 0.0035 mm~2.
基金supported by the National Key Research and Development Pro-gram of China(2021YFF0601902)the National Reference Material Development Project(S2022234).
文摘To solve the problem of the lack of reference material(RM)for determination of allergenic ingredients in food,a RM of cashew nut powder was developed in the study.Cashew nut powder was prepared from cashew nut kernel by selecting,cleaning,crushing,n-hexane degreasing and sieving treatment.The reliability and traceability of RM was verified using real-time quantitative polymerase chain reaction(qPCR)and phylogenetic tree analysis.The cashew nut powder RM showed good homogeneity,and good stability under long-term storage at 4℃and short-term simulated transportation from-20 to 45℃.The RM was determined jointly by 8 collaborative laboratories,and the characteristic CT value was 24.732,and the extended uncertainty was 1.052%(k=2).The RM was applied to verify the amplification efficiency and the limit of detection for qPCR assay,and showed good applicability.The RM could be used for method validation and quality control,for the determination of allergenic ingredients in food mixed with trace amounts of cashew nut.
基金the National Natural Science Foundation of China(NSFC)(Grant Nos.42030105,42274011,42074019,41974034,42204006)。
文摘Highly accurate international height reference frames with long-term stability,global consistency,and homogeneity are crucial for monitoring sea level variations,understanding climate change,managing disasters,and supporting other applications that benefit scientific research and societal well-being.Currently,there are over 100 local height reference systems worldwide.Unifying these systems is a pivotal step toward constructing international height reference frames.The method introduced in this study-the gravity frequency shift via Satellite Frequency Signal Transfer(SFST)-represents a groundbreaking relativistic geodetic approach,demonstrating its potential to surpass the constraints of conventional techniques.The advent of high-precision optical atomic clocks(OAC)with an accuracy level of 1×10^(-18) has facilitated this method's implementation.The International Association of Geodesy(IAG)has established the International Height Reference System(IHRS)and its practical realization,the International Height Reference Frame(IHRF).Our study focuses on two neighbouring height systems:the China Height System(CHS)and the Nepal Height System(NHS),separated by the Himalayas and the Xizang plateau.We aim to unify these two systems by determining the geopotential and orthometric height differences between their respective height datum stations:the Qingdao Height Datum Station(QHDS)and the Madar Height Datum Station(MHDS)using a simulation experiment with the method mentioned above.Using an OAC with an accuracy of 1×10^(-18),we identified a geopotential difference of-8.348±0.464 m^(2)s^(-2) and an orthometric height difference of 0.786±0.047 m between QHDS and MHDS.These results suggest that the introduced method could unify any two height systems with fewcentimeter-level precision,emphasizing its significance in contributing to the construction of the IHRS/IHRF with today's required precision.In summary,the SFST technique is a novel geodetic method that offers an alternative for height system unification,delivering centimeter-level precision,surpassing traditional methods,and supporting the development of the IHRF.
