The rapid advancement of quantum technology poses significant security risks to blockchain systems.However,quantum technology can also provide solutions for enhancing blockchain security.In this paper,we propose a qua...The rapid advancement of quantum technology poses significant security risks to blockchain systems.However,quantum technology can also provide solutions for enhancing blockchain security.In this paper,we propose a quantum-enhanced blockchain scheme to achieve a high level of security against quantum computing attacks.We first discuss quantum computing attacks on classic blockchains,including attacks on hash functions,digital signatures,and consensus mechanisms.We then introduce quantum technologies,such as a quantum hash function(QHF),a quantum digital signature(QDS),and proof of authority(PoA)consensus mechanism,into our scheme to improve the security of the blockchain system.Our security analysis demonstrates that our scheme offers superior security against quantum and classic attacks.Finally,we compare our scheme with previous works,showing that our scheme has achieved a perfect balance in terms of practicality,reliability,scalability,and efficiency.Overall,this work contributes to the ongoing research on quantum blockchain in the quantum era.展开更多
The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significan...The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significantly,such as the Global Navigation Satellite System(GNSS).Meanwhile,the GNSS is also an essential technique for sensing the variation of ionosphere.During the years of 2019—2023,a large number of Chinese geodesy scientists devoted much efforts to the geodesy related ionosphere.Due to the very limited length,the achievements are carried out from the following six aspects,including:①The ionospheric correction models for BDS and BDSBAS;②Real-time global ionospheric monitoring and modeling;③The ionospheric 2D and 3D modeling based on GNSS and LEO satellites;④The ionospheric prediction based on artificial intelligence;⑤The monitoring and mitigation of ionospheric disturbances for GNSS users;⑥The ionospheric related data products and classical applications.展开更多
The aim of our study was to evaluate the clinical efficacy of m FOLFOX-HAIC combined with donafenib and sintilimab conversion therapy followed by surgical resection of large hepatocellular carcinoma with portal vein t...The aim of our study was to evaluate the clinical efficacy of m FOLFOX-HAIC combined with donafenib and sintilimab conversion therapy followed by surgical resection of large hepatocellular carcinoma with portal vein tumor thrombus(PVTT).The clinical data of two patients with large hepatocellular carcinoma who were admitted to the Second Affiliated Hospital of Kunming Medical University were retrospectively collected.Both patients received m FOLFOX-HAIC combined with donafenib and sintilimab conversion therapy,followed by hepatectomy.Clinical data were reported,and clinical efficacy was evaluated.One patient had a 14.5×11.1 cm tumor with a tumor thrombus in the right portal vein.The other patient had a 12.1×8.3 cm tumor with portal and hepatic vein tumor thrombi.Both patients had CNLC stageⅢa prior to conversion therapy,which was reduced to stageⅠb after conversion therapy.Subsequently,the patient underwent open and laparoscopic right hemihepatectomies.Short-term high-intensity conversion therapy with m FOLFOXHAIC combined with donafenib and sintilimab is a feasible and effective treatment for patients with large hepatocellular carcinoma with PVTT.展开更多
Although a series of hypotheses have been proposed,the mechanism underlying coal and gas outburst remains unclear.Given the low-index outbursts encountered in mining practice,we attempt to explore this mechanism using...Although a series of hypotheses have been proposed,the mechanism underlying coal and gas outburst remains unclear.Given the low-index outbursts encountered in mining practice,we attempt to explore this mechanism using a multiphysics coupling model considering the effects of coal strength and gas mass transfer on failure.Based on force analysis of coal ahead of the heading face,a risk identification index C_(m)and a critical criterion(C_(m)≥1)of coal instability are proposed.According to this criterion,the driving force of an outburst consists of stress and gas pressure gradients along the heading direction of the roadway,whereas resistance depends on the shear and tensile strengths of the coal.The results show that outburst risk decreases slightly,followed by a rapid increase,with increasing vertical stress,whereas it decreases with increasing coal strength and increases with gas pressure monotonically.Using the response surface method,a coupled multi-factor model for the risk identification index is developed.The results indicate strong interactions among the controlling factors.Moreover,the critical values of the factors corresponding to outburst change depending on the environment of the coal seams,rather than being constants.As the buried depth of a coal seam increases,the critical values of gas pressure and coal strength decrease slightly,followed by a rapid increase.According to its controlling factors,outburst can be divided into stress-dominated,coal-strength-dominated,gas-pressure-dominated,and multi-factor compound types.Based on this classification,a classified control method is proposed to enable more targeted outburst prevention.展开更多
This paper focuses on anisotropy of coal permeability and its stress sensitivity.Coal blocks were taken from Xinjing Coal Mine in Yangquan Coal District.Coal cores were then drilled along the strike,dip,and vertical d...This paper focuses on anisotropy of coal permeability and its stress sensitivity.Coal blocks were taken from Xinjing Coal Mine in Yangquan Coal District.Coal cores were then drilled along the strike,dip,and vertical directions.Coal permeabilities were measured with respect to stress by using a self-developed coal permeability measurement system.The used samples exhibited significant permeability anisotropy.The permeability along the strike direction was greatest among the three directions,the permeability along the vertical direction was the smallest,and the permeability along the dip direction was between the other two directions.The sensitivity of coal permeability to stress was transversely isotropic.The stress sensitivity coefficient was greater along the horizontal directions than along the vertical directions.Coal permeability exhibited anisotropic stress sensitivity due to anisotropy in Young’s modulus and porosity.The results obtained in this study are useful for optimizing the arrangement of pre-drainage boreholes.展开更多
Coal-water interactions have profound influences on gas extraction from coal and coal utilization.Experimental measurements on three coals using X-ray photoelectron spectroscopy(XPS),low-temperature nitrogen adsorptio...Coal-water interactions have profound influences on gas extraction from coal and coal utilization.Experimental measurements on three coals using X-ray photoelectron spectroscopy(XPS),low-temperature nitrogen adsorption and dynamic water vapor sorption(DVS)were conducted.A mechanism-based isotherm model was proposed to estimate the water vapor uptake at various relative humidities,which is well validated with the DVS data.The validated isotherm model of sorption was further used to derive the isosteric heat of water vapor sorption.The specific surface area of coal pores is not the determining parameter that controls water vapor sorption at least during the primary adsorption stage.Oxidation degree dominates the primary adsorption,and which togethering with the cumulative pore volume determine the secondary adsorption.Higher temperature has limited effects on primary adsorption process.The isosteric heat of water adsorption decreases as water vapor uptake increases,which is found to be close to the latent heat of bulk water condensation at higher relative humidity.The results confirmed that the primary adsorption is controlled by the stronger bonding energy while the interaction energy between water molecules during secondary adsorption stage is relatively weak.However,the thermodynamics of coal-water interactions are complicated since the internal bonding interactions within the coal are disrupted at the same time as new bonding interactions take place within water molecules.Coal has a shrinkage/swelling colloidal structure with moisture loss/gain and it may exhibit collapse behavior with some collapses irreversible as a function of relative humidity,which further plays a significant role in determining moisture retention.展开更多
The rapid development of information and communication technologies(ICTs)and cyber-physical systems(CPSs)has paved the way for the increasing popularity of smart products.Context-awareness is an important facet of pro...The rapid development of information and communication technologies(ICTs)and cyber-physical systems(CPSs)has paved the way for the increasing popularity of smart products.Context-awareness is an important facet of product smartness.Unlike artifacts,various bio-systems are naturally characterized by their extraordinary context-awareness.Biologically inspired design(BID)is one of the most commonly employed design strategies.However,few studies have examined the BID of context-aware smart products to date.This paper presents a structured design framework to support the BID of context-aware smart products.The meaning of context-awareness is defined from the perspective of product design.The framework is developed based on the theoretical foundations of the situated function-behavior-structure ontology.A structured design process is prescribed to leverage various biological inspirations in order to support different conceptual design activities,such as problem formulation,structure reformulation,behavior reformulation,and function reformulation.Some existing design methods and emerging design tools are incorporated into the framework.A case study is presented to showcase how this framework can be followed to redesign a robot vacuum cleaner and make it more context-aware.展开更多
High nitrogen stainless steel with nitrogen content of 0.75%was welded by gas metal arc welding with Ar-N_(2)-O_(2)ternary shielding gas.The effect of the ternary shielding gas on the retention and improvement of nitr...High nitrogen stainless steel with nitrogen content of 0.75%was welded by gas metal arc welding with Ar-N_(2)-O_(2)ternary shielding gas.The effect of the ternary shielding gas on the retention and improvement of nitrogen content in the weld was identified.Surfacing test was conducted first to compare the ability of O_(2)and CO_(2)in prompting nitrogen dissolution.The nitrogen content of the surfacing metal with O_(2)is slightly higher than CO_(2).And then AreN_(2)-O_(2)shielding gas was applied to weld high nitrogen stainless steel.After using N_(2)-containing shielding gas,the nitrogen content of the weld was improved by 0.1 wt%.As N_(2)continued to increase,the increment of nitrogen content was not obvious,but the ferrite decreased from the top to the bottom.When the proportion of N_(2)reached 20%,a full austenitic weld was obtained and the tensile strength was improved by 8.7%.Combined with the results of surfacing test and welding test,it is concluded that the main effect of N_(2)is to inhibit the escape of nitrogen and suppress the nitrogen diffusion from bottom to the top in the molten pool.展开更多
Paraphlomis is a genus of Lamiaceae with about 30 species distributed mainly in subtropical China.In this study,we carried out the first molecular phylogenetic analyses to elucidate the relationships within the genus ...Paraphlomis is a genus of Lamiaceae with about 30 species distributed mainly in subtropical China.In this study,we carried out the first molecular phylogenetic analyses to elucidate the relationships within the genus based on two nuclear and four plastid DNA regions.Our results,which recovered a species of Matsumurella within Paraphlomis,indicate that the genus is not monophyletic.The two sections and most of the series previously described within the genus are also shown to be polyphyletic.Combining with morphological evidence,our study indicates that nutlet morphology rather than calyx morphology is of phylogenetic value for the infrageneric classification of Paraphlomis.Moreover,P.jiangyongensis,a new species from southern China,is here described,and P.coronata,formerly treated as a variety of P.javanica,is here resurrected as a distinct species within the genus.展开更多
The 19th National Congress of the Communist Party of China put forward the strategy of Rural Revitalization.Effective governance is the key to rural revitalization.Effective rural governance needs to properly deal wit...The 19th National Congress of the Communist Party of China put forward the strategy of Rural Revitalization.Effective governance is the key to rural revitalization.Effective rural governance needs to properly deal with the ethical relationship in the process of governance.The study of rural governance ethics in China includes three kinds of path choices.They are paradigm shift from top-down to bottom-up,organic integration of special and general,and interweaving between tradition and modernity.The paradigm shift from top-down to bottom-up needs to be done by methods,such as the use of the relationship between theory and practice,the change from abstract research to applied research,and the implementation of fieldwork surveys.Special and general organic integration depends on methods,such as the law of contradiction specificity and universality,the cooperation of induction and deduction,the operation of case studies,etc.The interweaving of tradition and modernity requires methods to be realized,such as the negation of negation,moral narrative,and non-intrusive research.展开更多
To ensure the performance of the optical system, the machining accuracy of lens with long focal lengths is required to ensure the image quality. A new method for lens transmission wavefront power spectral density (PSD...To ensure the performance of the optical system, the machining accuracy of lens with long focal lengths is required to ensure the image quality. A new method for lens transmission wavefront power spectral density (PSD) in mid-frequency domain measurement using binary phase computer-generated hologram (CGH) is presented. This technique is widely applicable and is particularly useful for measuring large-size lenses with long focal lengths. A comparison experiment of the CGH measurement with results from a Fizeau sphere interferometry method is carried out to verify the accuracy and convenience of the measurement. Furthermore, measurement uncertainty due to CGH fabrication process is analysed. Analysis of the CGH test showed the overall accuracy of less than 1 nm RMS for a sphere lens with over 30 m focal length and Φ410 mm clear aperture. CGH can provide reference spheres with high precision, in the meantime greatly shorten air space, thus reducing the effect of vibration and air turbulence, therefore is of great importance for lens transmission wavefront PSD measurement. The realization of high precision, high efficiency and nondestructive testing of long focal-lens wavefront PSD ensure the ultra-precision and certainty level of machining, hence improving the comprehensive performance of the optical system.展开更多
To optimize the experimental conditions of MTT colorimetric assay for HSS bioactivity in vitro,we studied the optimal combination of the major conditions of the MTT assay by orthogonal test and other experiments,and c...To optimize the experimental conditions of MTT colorimetric assay for HSS bioactivity in vitro,we studied the optimal combination of the major conditions of the MTT assay by orthogonal test and other experiments,and compared HSS bioactivity in vitro measured by the improved MTT protocol and published MTT assay at serial protein doses.Results showed that the absorbance value(A value)of the MTT assay directly correlated with the number of human hepatoma cell lines SMMC7721.The result of orthogonal test was the number of 5×104 SMMC7721 cells/ml,culture period 6 h before adding HSS,concentration of HSS 100μg/ml,incubation time with HSS 36 h.Additionally,several experiments demonstrated the optimal combination of other conditions was 50μg MTT,incubation time for MTT 6 h,DMSO was used to dissolve the MTT formazan crystals and measured with ELISA scanner at 570 nm.The result of determining HSS bio-activity in vitro by optimized MTT protocol showed that sHSS bio-activity increased with the growth of protein dose,but decreased when it beyond a certain dose.The optimized MTT protocol was a sensitive,convenient and stable quantitative method to evaluate HSS bio-activity.展开更多
The availability of raw Global Navigation Satellite System(GNSS)measurements from Android smart devices gives new possibilities for precise positioning solutions,e.g.,Precise Point Positioning(PPP).However,the accurac...The availability of raw Global Navigation Satellite System(GNSS)measurements from Android smart devices gives new possibilities for precise positioning solutions,e.g.,Precise Point Positioning(PPP).However,the accuracy of the PPP with smart devices currently is a few meters due to the poor quality of the raw GNSS measurements in a kinematic scenario and in urban environments,particularly when the smart devices are placed inside vehicles.To promote the application of GNSS PPP for land vehicle navigation with smart devices,this contribution studies the real-time PPP with smartphones.For data quality analysis and positioning performance validation,two vehicle-based kinematic positioning tests were carried out using two Huawei Mate30 smartphones and two Huawei P40 smartphones with different installation modes:the vehicle-roof mode with smartphones mounted on the top roof outside the vehicle,and the dashboard mode with smartphones stabilized on the dashboard inside the vehicle.To realize high accuracy positioning,we proposed a real-time smartphone PPP method with the data processing strategies adapted for smart devices.Positioning results show that the real-time PPP can achieve the horizontal positioning accuracy of about 1–1.5 m in terms of root-mean-square and better than 2.5 m at the 95th percentile for the vehicle-based kinematic positioning with the experimental smartphones mounted on the dashboard inside the vehicle,which is the real scenario in vehicle navigation.展开更多
Sweat is a biofluid with rich information that can reflect an individual’s state of health or activity.But the real-time in situ sweat sensors lack the ability of long-term monitoring.Against this background,this art...Sweat is a biofluid with rich information that can reflect an individual’s state of health or activity.But the real-time in situ sweat sensors lack the ability of long-term monitoring.Against this background,this article provides a holistic review on the necessary process and methods for sweat sensing,including sweat collection,composition analysis,energy supply,and data processing.The impacts of the environment in stimulating sweat production,providing energy supply,and intelligent health monitoring are discussed.Based on the review of previous endeavors,the future development in material,structure and artificial intelligence application of long-term sweat monitoring is envisioned.展开更多
As a new Ionosphere Associate Analysis Center(IAAC)of the International GNSS Service(IGS),Chinese Academy of Sciences(CAS)started the routine computation of the real-time,rapid,and final Global Ionospheric Maps(GIMs)i...As a new Ionosphere Associate Analysis Center(IAAC)of the International GNSS Service(IGS),Chinese Academy of Sciences(CAS)started the routine computation of the real-time,rapid,and final Global Ionospheric Maps(GIMs)in 2015.The method for the generation of CAS rapid and final GIMs and recent updates are presented in the paper.The quality of CAS post-processed GIMs is assessed during 2015-2018 after the maximum of solar cycle 24.To perform an independent and fair assessment,Jason-2/3 Vertical Total Electron Contents(VTEC)are first used as the references over the ocean.GPS differential Slant TECs(dSTEC)generated from 55 Multi-GNSS Experimental(MGEX)stations of the IGS are also employed,which provides a complementing way to evaluate the ability of electron content models to reproduce the spatial and temporal gradients in the ionosphere.During the test period,Jet Propulsion Laboratory(JPL)GIMs present significantly positive deviations compared to the Jason VTEC and GPS dSTEC.Technical University of Catalonia(UPC)rapid GIM UQRG exhibits the best performance in both Jason VTEC and GPS dSTEC analysis.The CAS GIMs show comparable performance with the results of the first four IAACs of the IGS.As expected,the poor performance of all GIMs is in equatorial regions and the high latitudes of the southern hemisphere.The consideration of generating multi-layer or three-dimensional ionospheric maps is emphasized to mitigate the inadequacy of ionospheric single-layer assumption in the presence of pronounced latitudinal gradients.The use of ionospheric observations from the new GNSS constellations and other space-or ground-based observation techniques is also suggested in the generation of future GIMs,given the sparse GPS/GLONASS stations in the southern hemisphere.展开更多
Complexity management is one of the most crucial and challenging issues in manufacturing.As an emerging technology,digital twin provides an innovative approach to manage complexity in a more autonomous,analytical and ...Complexity management is one of the most crucial and challenging issues in manufacturing.As an emerging technology,digital twin provides an innovative approach to manage complexity in a more autonomous,analytical and comprehensive manner.This paper proposes an innovative framework of digital twin-driven complexity management in intelligent manufacturing.The framework will cover three sources of manufacturing complexity,including product design,production lines and supply chains.Digital twin provides three services to manage complexity:(1)real-time monitors and data collections;(2)identifications,diagnoses and predictions of manufacturing complexity;(3)fortification of human-machine interaction.A case study of airplane manufacturing is presented to illustrate the proposed framework.展开更多
基金supported byResearch on SatelliteQuantumKeyNetwork Security Architecture(No.AHY180500)This work was supported by the Research on Digital Identity Trust System for Massive Heterogeneous Terminals in Road Traffic System(No.2022YFB3104402)+2 种基金This work was supported in part by National Key RD Program of China(No.2018YFB0803401)in part by the China Postdoctoral Science Foundation under Grant 2019M650606in part by First-class Discipline Construction Project of Beijing Electronic Science and Technology Institute(No.3201012).
文摘The rapid advancement of quantum technology poses significant security risks to blockchain systems.However,quantum technology can also provide solutions for enhancing blockchain security.In this paper,we propose a quantum-enhanced blockchain scheme to achieve a high level of security against quantum computing attacks.We first discuss quantum computing attacks on classic blockchains,including attacks on hash functions,digital signatures,and consensus mechanisms.We then introduce quantum technologies,such as a quantum hash function(QHF),a quantum digital signature(QDS),and proof of authority(PoA)consensus mechanism,into our scheme to improve the security of the blockchain system.Our security analysis demonstrates that our scheme offers superior security against quantum and classic attacks.Finally,we compare our scheme with previous works,showing that our scheme has achieved a perfect balance in terms of practicality,reliability,scalability,and efficiency.Overall,this work contributes to the ongoing research on quantum blockchain in the quantum era.
基金National Key R&D Program of China(No.2021YFB3901301)National Natural Science Foundation of China(Nos.42074043,42122026,42174038)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y9E006033D)。
文摘The ionosphere is the ionized part of the upper atmosphere of the Earth,which plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere.It influences radio propagation significantly,such as the Global Navigation Satellite System(GNSS).Meanwhile,the GNSS is also an essential technique for sensing the variation of ionosphere.During the years of 2019—2023,a large number of Chinese geodesy scientists devoted much efforts to the geodesy related ionosphere.Due to the very limited length,the achievements are carried out from the following six aspects,including:①The ionospheric correction models for BDS and BDSBAS;②Real-time global ionospheric monitoring and modeling;③The ionospheric 2D and 3D modeling based on GNSS and LEO satellites;④The ionospheric prediction based on artificial intelligence;⑤The monitoring and mitigation of ionospheric disturbances for GNSS users;⑥The ionospheric related data products and classical applications.
基金Supported by grants from the Clinical Research Program of Kunming Medical University(No.yn IIT20211013)the Joint Special Fund Project of Kunming Medical University(No.202201AY070001-105)。
文摘The aim of our study was to evaluate the clinical efficacy of m FOLFOX-HAIC combined with donafenib and sintilimab conversion therapy followed by surgical resection of large hepatocellular carcinoma with portal vein tumor thrombus(PVTT).The clinical data of two patients with large hepatocellular carcinoma who were admitted to the Second Affiliated Hospital of Kunming Medical University were retrospectively collected.Both patients received m FOLFOX-HAIC combined with donafenib and sintilimab conversion therapy,followed by hepatectomy.Clinical data were reported,and clinical efficacy was evaluated.One patient had a 14.5×11.1 cm tumor with a tumor thrombus in the right portal vein.The other patient had a 12.1×8.3 cm tumor with portal and hepatic vein tumor thrombi.Both patients had CNLC stageⅢa prior to conversion therapy,which was reduced to stageⅠb after conversion therapy.Subsequently,the patient underwent open and laparoscopic right hemihepatectomies.Short-term high-intensity conversion therapy with m FOLFOXHAIC combined with donafenib and sintilimab is a feasible and effective treatment for patients with large hepatocellular carcinoma with PVTT.
基金This work was supported by the National Natural Science Foundation of China(52004276)National Postdoctoral Program for Innovative Talents(BX20190369)+1 种基金Natural Science Foundation of Jiangsu Province(BK20200636)China Postdoctoral Science Foundation(2019M661996).
文摘Although a series of hypotheses have been proposed,the mechanism underlying coal and gas outburst remains unclear.Given the low-index outbursts encountered in mining practice,we attempt to explore this mechanism using a multiphysics coupling model considering the effects of coal strength and gas mass transfer on failure.Based on force analysis of coal ahead of the heading face,a risk identification index C_(m)and a critical criterion(C_(m)≥1)of coal instability are proposed.According to this criterion,the driving force of an outburst consists of stress and gas pressure gradients along the heading direction of the roadway,whereas resistance depends on the shear and tensile strengths of the coal.The results show that outburst risk decreases slightly,followed by a rapid increase,with increasing vertical stress,whereas it decreases with increasing coal strength and increases with gas pressure monotonically.Using the response surface method,a coupled multi-factor model for the risk identification index is developed.The results indicate strong interactions among the controlling factors.Moreover,the critical values of the factors corresponding to outburst change depending on the environment of the coal seams,rather than being constants.As the buried depth of a coal seam increases,the critical values of gas pressure and coal strength decrease slightly,followed by a rapid increase.According to its controlling factors,outburst can be divided into stress-dominated,coal-strength-dominated,gas-pressure-dominated,and multi-factor compound types.Based on this classification,a classified control method is proposed to enable more targeted outburst prevention.
基金funding support of the State Key Research Development Program of China (Nos. 2016YFC0600708 and 2016YFC0801402)
文摘This paper focuses on anisotropy of coal permeability and its stress sensitivity.Coal blocks were taken from Xinjing Coal Mine in Yangquan Coal District.Coal cores were then drilled along the strike,dip,and vertical directions.Coal permeabilities were measured with respect to stress by using a self-developed coal permeability measurement system.The used samples exhibited significant permeability anisotropy.The permeability along the strike direction was greatest among the three directions,the permeability along the vertical direction was the smallest,and the permeability along the dip direction was between the other two directions.The sensitivity of coal permeability to stress was transversely isotropic.The stress sensitivity coefficient was greater along the horizontal directions than along the vertical directions.Coal permeability exhibited anisotropic stress sensitivity due to anisotropy in Young’s modulus and porosity.The results obtained in this study are useful for optimizing the arrangement of pre-drainage boreholes.
基金This study was sponsored by the Open Fund Project Funded by State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University(Grant#2011DA105287-FW201903)We also want to thank the China Scholarship Council(CSC)for the financial support(Grant#201806430028).
文摘Coal-water interactions have profound influences on gas extraction from coal and coal utilization.Experimental measurements on three coals using X-ray photoelectron spectroscopy(XPS),low-temperature nitrogen adsorption and dynamic water vapor sorption(DVS)were conducted.A mechanism-based isotherm model was proposed to estimate the water vapor uptake at various relative humidities,which is well validated with the DVS data.The validated isotherm model of sorption was further used to derive the isosteric heat of water vapor sorption.The specific surface area of coal pores is not the determining parameter that controls water vapor sorption at least during the primary adsorption stage.Oxidation degree dominates the primary adsorption,and which togethering with the cumulative pore volume determine the secondary adsorption.Higher temperature has limited effects on primary adsorption process.The isosteric heat of water adsorption decreases as water vapor uptake increases,which is found to be close to the latent heat of bulk water condensation at higher relative humidity.The results confirmed that the primary adsorption is controlled by the stronger bonding energy while the interaction energy between water molecules during secondary adsorption stage is relatively weak.However,the thermodynamics of coal-water interactions are complicated since the internal bonding interactions within the coal are disrupted at the same time as new bonding interactions take place within water molecules.Coal has a shrinkage/swelling colloidal structure with moisture loss/gain and it may exhibit collapse behavior with some collapses irreversible as a function of relative humidity,which further plays a significant role in determining moisture retention.
基金This work was supported in part by the project of the National Natural Science Foundation of China(51875030).
文摘The rapid development of information and communication technologies(ICTs)and cyber-physical systems(CPSs)has paved the way for the increasing popularity of smart products.Context-awareness is an important facet of product smartness.Unlike artifacts,various bio-systems are naturally characterized by their extraordinary context-awareness.Biologically inspired design(BID)is one of the most commonly employed design strategies.However,few studies have examined the BID of context-aware smart products to date.This paper presents a structured design framework to support the BID of context-aware smart products.The meaning of context-awareness is defined from the perspective of product design.The framework is developed based on the theoretical foundations of the situated function-behavior-structure ontology.A structured design process is prescribed to leverage various biological inspirations in order to support different conceptual design activities,such as problem formulation,structure reformulation,behavior reformulation,and function reformulation.Some existing design methods and emerging design tools are incorporated into the framework.A case study is presented to showcase how this framework can be followed to redesign a robot vacuum cleaner and make it more context-aware.
文摘High nitrogen stainless steel with nitrogen content of 0.75%was welded by gas metal arc welding with Ar-N_(2)-O_(2)ternary shielding gas.The effect of the ternary shielding gas on the retention and improvement of nitrogen content in the weld was identified.Surfacing test was conducted first to compare the ability of O_(2)and CO_(2)in prompting nitrogen dissolution.The nitrogen content of the surfacing metal with O_(2)is slightly higher than CO_(2).And then AreN_(2)-O_(2)shielding gas was applied to weld high nitrogen stainless steel.After using N_(2)-containing shielding gas,the nitrogen content of the weld was improved by 0.1 wt%.As N_(2)continued to increase,the increment of nitrogen content was not obvious,but the ferrite decreased from the top to the bottom.When the proportion of N_(2)reached 20%,a full austenitic weld was obtained and the tensile strength was improved by 8.7%.Combined with the results of surfacing test and welding test,it is concluded that the main effect of N_(2)is to inhibit the escape of nitrogen and suppress the nitrogen diffusion from bottom to the top in the molten pool.
基金This work was supported by the National Natural Science Foundation of China(Grant No.31872648)the Yunnan Fundamental Research Projects(Grant No.2019FI009)+1 种基金the“Ten Thousand Talents Program of Yunnan”(Grant No.YNWRQNBJ-2018-279)CLX,the CAS“Light of West China”program to CLX and YPC,and the“Special Investigation on Wild Orchidaceae Plant Resources in Hunan Province”program(Grant No.2020070711)to XLY.
文摘Paraphlomis is a genus of Lamiaceae with about 30 species distributed mainly in subtropical China.In this study,we carried out the first molecular phylogenetic analyses to elucidate the relationships within the genus based on two nuclear and four plastid DNA regions.Our results,which recovered a species of Matsumurella within Paraphlomis,indicate that the genus is not monophyletic.The two sections and most of the series previously described within the genus are also shown to be polyphyletic.Combining with morphological evidence,our study indicates that nutlet morphology rather than calyx morphology is of phylogenetic value for the infrageneric classification of Paraphlomis.Moreover,P.jiangyongensis,a new species from southern China,is here described,and P.coronata,formerly treated as a variety of P.javanica,is here resurrected as a distinct species within the genus.
基金Funding for this work was provided through the Project of Philosophy and Social Science Research in Colleges and Universities in Jiangsu Province(Project No.2019SJB072),the National Philosophy and Social Science Foundation(Project No.15ZDB014),the Jiangsu Province Social Science Foundation Youth Program(Project No.18ZXC003),key research base of philosophy and social science in universities in Jiangsu Province:Rural Culture Revitalization Research Center(Project No.2018ZDJD-A005).
文摘The 19th National Congress of the Communist Party of China put forward the strategy of Rural Revitalization.Effective governance is the key to rural revitalization.Effective rural governance needs to properly deal with the ethical relationship in the process of governance.The study of rural governance ethics in China includes three kinds of path choices.They are paradigm shift from top-down to bottom-up,organic integration of special and general,and interweaving between tradition and modernity.The paradigm shift from top-down to bottom-up needs to be done by methods,such as the use of the relationship between theory and practice,the change from abstract research to applied research,and the implementation of fieldwork surveys.Special and general organic integration depends on methods,such as the law of contradiction specificity and universality,the cooperation of induction and deduction,the operation of case studies,etc.The interweaving of tradition and modernity requires methods to be realized,such as the negation of negation,moral narrative,and non-intrusive research.
文摘To ensure the performance of the optical system, the machining accuracy of lens with long focal lengths is required to ensure the image quality. A new method for lens transmission wavefront power spectral density (PSD) in mid-frequency domain measurement using binary phase computer-generated hologram (CGH) is presented. This technique is widely applicable and is particularly useful for measuring large-size lenses with long focal lengths. A comparison experiment of the CGH measurement with results from a Fizeau sphere interferometry method is carried out to verify the accuracy and convenience of the measurement. Furthermore, measurement uncertainty due to CGH fabrication process is analysed. Analysis of the CGH test showed the overall accuracy of less than 1 nm RMS for a sphere lens with over 30 m focal length and Φ410 mm clear aperture. CGH can provide reference spheres with high precision, in the meantime greatly shorten air space, thus reducing the effect of vibration and air turbulence, therefore is of great importance for lens transmission wavefront PSD measurement. The realization of high precision, high efficiency and nondestructive testing of long focal-lens wavefront PSD ensure the ultra-precision and certainty level of machining, hence improving the comprehensive performance of the optical system.
文摘To optimize the experimental conditions of MTT colorimetric assay for HSS bioactivity in vitro,we studied the optimal combination of the major conditions of the MTT assay by orthogonal test and other experiments,and compared HSS bioactivity in vitro measured by the improved MTT protocol and published MTT assay at serial protein doses.Results showed that the absorbance value(A value)of the MTT assay directly correlated with the number of human hepatoma cell lines SMMC7721.The result of orthogonal test was the number of 5×104 SMMC7721 cells/ml,culture period 6 h before adding HSS,concentration of HSS 100μg/ml,incubation time with HSS 36 h.Additionally,several experiments demonstrated the optimal combination of other conditions was 50μg MTT,incubation time for MTT 6 h,DMSO was used to dissolve the MTT formazan crystals and measured with ELISA scanner at 570 nm.The result of determining HSS bio-activity in vitro by optimized MTT protocol showed that sHSS bio-activity increased with the growth of protein dose,but decreased when it beyond a certain dose.The optimized MTT protocol was a sensitive,convenient and stable quantitative method to evaluate HSS bio-activity.
基金National Natural Science Foundation of China(42104027)cooperative research project with Huawei,the Alliance of International Science Organizations(ANSO-CRKP-2020-12)Youth Innovation Promotion Association and Future Star Program of the Chinese Academy of Sciences.
文摘The availability of raw Global Navigation Satellite System(GNSS)measurements from Android smart devices gives new possibilities for precise positioning solutions,e.g.,Precise Point Positioning(PPP).However,the accuracy of the PPP with smart devices currently is a few meters due to the poor quality of the raw GNSS measurements in a kinematic scenario and in urban environments,particularly when the smart devices are placed inside vehicles.To promote the application of GNSS PPP for land vehicle navigation with smart devices,this contribution studies the real-time PPP with smartphones.For data quality analysis and positioning performance validation,two vehicle-based kinematic positioning tests were carried out using two Huawei Mate30 smartphones and two Huawei P40 smartphones with different installation modes:the vehicle-roof mode with smartphones mounted on the top roof outside the vehicle,and the dashboard mode with smartphones stabilized on the dashboard inside the vehicle.To realize high accuracy positioning,we proposed a real-time smartphone PPP method with the data processing strategies adapted for smart devices.Positioning results show that the real-time PPP can achieve the horizontal positioning accuracy of about 1–1.5 m in terms of root-mean-square and better than 2.5 m at the 95th percentile for the vehicle-based kinematic positioning with the experimental smartphones mounted on the dashboard inside the vehicle,which is the real scenario in vehicle navigation.
基金supported by the State Key Laboratory of Mechanical System and Vibration Project (Grant no.MSVZD202108)the open project of National Research Center for Translational Medicine,Shanghai (Project no.TMSK2021-146).
文摘Sweat is a biofluid with rich information that can reflect an individual’s state of health or activity.But the real-time in situ sweat sensors lack the ability of long-term monitoring.Against this background,this article provides a holistic review on the necessary process and methods for sweat sensing,including sweat collection,composition analysis,energy supply,and data processing.The impacts of the environment in stimulating sweat production,providing energy supply,and intelligent health monitoring are discussed.Based on the review of previous endeavors,the future development in material,structure and artificial intelligence application of long-term sweat monitoring is envisioned.
基金the National Key Research Program of China(No.2017YFE0131400)the Alliance of International Science Organizations(No.ANSO-CR-KP-2020-12)+3 种基金the National Natural Science Foundation of China(42074043)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(YJKYYQ20190071)AK acknowledges the financial support from Ministry of Science and Higher Education(MSHE),Poland(MSHE Decision Nos.DIR/WK/2016/2017/05-1 and 59/E-383/SPUB/SP/2019.1)the National Centre for Research and Development,Poland(Decision No.DWM/PL-CHN/97/2019,WPC1/ARTEMIS/2019).
文摘As a new Ionosphere Associate Analysis Center(IAAC)of the International GNSS Service(IGS),Chinese Academy of Sciences(CAS)started the routine computation of the real-time,rapid,and final Global Ionospheric Maps(GIMs)in 2015.The method for the generation of CAS rapid and final GIMs and recent updates are presented in the paper.The quality of CAS post-processed GIMs is assessed during 2015-2018 after the maximum of solar cycle 24.To perform an independent and fair assessment,Jason-2/3 Vertical Total Electron Contents(VTEC)are first used as the references over the ocean.GPS differential Slant TECs(dSTEC)generated from 55 Multi-GNSS Experimental(MGEX)stations of the IGS are also employed,which provides a complementing way to evaluate the ability of electron content models to reproduce the spatial and temporal gradients in the ionosphere.During the test period,Jet Propulsion Laboratory(JPL)GIMs present significantly positive deviations compared to the Jason VTEC and GPS dSTEC.Technical University of Catalonia(UPC)rapid GIM UQRG exhibits the best performance in both Jason VTEC and GPS dSTEC analysis.The CAS GIMs show comparable performance with the results of the first four IAACs of the IGS.As expected,the poor performance of all GIMs is in equatorial regions and the high latitudes of the southern hemisphere.The consideration of generating multi-layer or three-dimensional ionospheric maps is emphasized to mitigate the inadequacy of ionospheric single-layer assumption in the presence of pronounced latitudinal gradients.The use of ionospheric observations from the new GNSS constellations and other space-or ground-based observation techniques is also suggested in the generation of future GIMs,given the sparse GPS/GLONASS stations in the southern hemisphere.
基金This research is funded by the Key Project of International(Regional)Cooperation and Exchange of the National Natural Science Foundation of China(52120105008).The principal investigators are Fei Tao and Ang Liu.
文摘Complexity management is one of the most crucial and challenging issues in manufacturing.As an emerging technology,digital twin provides an innovative approach to manage complexity in a more autonomous,analytical and comprehensive manner.This paper proposes an innovative framework of digital twin-driven complexity management in intelligent manufacturing.The framework will cover three sources of manufacturing complexity,including product design,production lines and supply chains.Digital twin provides three services to manage complexity:(1)real-time monitors and data collections;(2)identifications,diagnoses and predictions of manufacturing complexity;(3)fortification of human-machine interaction.A case study of airplane manufacturing is presented to illustrate the proposed framework.
