Objective To provide new ideas for the effective treatment of many serious diseases and to solve many major medical problems faced by mankind.Methods In this paper,the invention patents in the field of stem cells in C...Objective To provide new ideas for the effective treatment of many serious diseases and to solve many major medical problems faced by mankind.Methods In this paper,the invention patents in the field of stem cells in China from 2010 to 2020 were taken as the research object,and the technology status quo in the field of stem cells was analyzed to predict the future development direction through quantitative analysis method.Results and Conclusion The development of stem cell technology in China is in a period of growth with great potential.Therefore,it is necessary to strengthen the ability of Chinese universities to combine production,education and research.Nowadays,the hotspots in stem cell technology are using culture medium to improve cell proliferation ability,production efficiency,and to induce differentiated cells.Meanwhile,the production efficiency of embryonic stem cells should be improved,and the immunomodulatory effect of embryonic stem cells can be exerted to screen drugs.Besides,the function of hematopoietic stem cells should be enhanced and apply mesenchymal cells in therapy.Since the potential technological gaps are the improvement of therapy,induced differentiation and efficiency of pluripotent stem cells,the improvement of progenitor cell proliferation and the control of cost,we should strengthen R&D investment in culture medium,embryonic stem cells and other technical fields,and achieve the purpose of reducing R&D costs and improving R&D efficiency.展开更多
Pavement distress detection(PDD)plays a vital role in planning timely pavement maintenance that improves pavement service life.In order to promote the development of PDD technologies and find out the insufficiencies i...Pavement distress detection(PDD)plays a vital role in planning timely pavement maintenance that improves pavement service life.In order to promote the development of PDD technologies and find out the insufficiencies in PDD field,this paper reviews the technical development history and characteristics of various PDD technologies,which contributes to the current state of research on PDD.First,processes of PDD are briefly introduced.The PDD technologies based on radar ranging,2D image,laser ranging and 3 D structured light are illustrated.The newest 3D PDD technology based on interference fringe,which has better accuracy,is in progress.The principles and implementation processes of these methods are discussed.Finally,the shortcomings of these technologies in the field of PDD are concluded.Recommendations for future development are provided.The research results show that various PDD technologies have been continuously improved,developed,over the past decade,and have achieved a series of results.However,the measurements from existing PDD technologies can not be metrological traced to acquire the true dimensions of pavement distresses.The lack of metrological traceability technology in the PDD field needs to be further solved.In order to achieve more accurate and efficient PDD,the metrological traceability technology of PDD systems has become the future development direction in this field.展开更多
With the theory and methods of system engineering,new ideas and structure system are used to disuses how to establish modern metrological system in this paper.It deeply studies value transmit system; metrological info...With the theory and methods of system engineering,new ideas and structure system are used to disuses how to establish modern metrological system in this paper.It deeply studies value transmit system; metrological information system; enterprise measurement assurance system,and discusses that the use of system methods can spur modern metrology on to great development.展开更多
This paper, first, presents the main points of national policies and regulations, and a series of technical standards concerning legal metrological units, and bries the importance and urgency of using legal metrologic...This paper, first, presents the main points of national policies and regulations, and a series of technical standards concerning legal metrological units, and bries the importance and urgency of using legal metrological unit in the seismological system. Secondly, it examined the present situation in using legal metrological unit by checking six selected kinds of Seismological periodicals against national standard and provided in the form of tables typical error-correcting examples in using legal metrological unit for the responsibles (authors) and editorial departments.Finally,based on statistic, it analysed the causes for the existing problems and offered proposals for emphasizing the use of legal metrological units in the seismological system.展开更多
The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibra...The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibrate the corresponding instruments.We develop a new reference material with nominal CDs of 160 nm,80 nm,and 40 nm.The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology(NIM)in China.Also,we propose a new characterization method for the precise measurement of CD values.After filtering and leveling the intensity profiles,the line features are characterized by the combination model of the Gaussian and Lorentz functions.The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm.Then the width of the two edges at the half intensity position is regarded as the standard CD value.Finally,the measurement results are evaluated in terms of the sample,instrument,algorithm,and repeatability.The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.展开更多
Wireless M-Bus according to EN-13757-4 is a major contender for local metrological network （LMN） in smart metering and smart grid applications, as it holds the promise of flexible and optimized solutions. It enjoys ...Wireless M-Bus according to EN-13757-4 is a major contender for local metrological network （LMN） in smart metering and smart grid applications, as it holds the promise of flexible and optimized solutions. It enjoys wide popularity in continental Europe, but increasingly in many other regions of the world. However, Wireless M-Bus is characterized by a wide variety of different operation modes （C-, F-, N-, P-, Q-, R-, S-, and T-modes）, which work in different frequency bands （i.e., 868 MHz, 433 MHz, and 169 MHz）. Its application layer can be enhanced by extensions, being defined from vendor alliances, like the Open Metering System （OMS） Group, or from national bodies.展开更多
We propose and experimentally demonstrate a universal and blind polarization-state tracking scheme for M-quadrature amplitude modulation（QAM） signals based on a decision-free radius-directed linear Kalman filter（RD...We propose and experimentally demonstrate a universal and blind polarization-state tracking scheme for M-quadrature amplitude modulation（QAM） signals based on a decision-free radius-directed linear Kalman filter（RD-LKF）.The polarization tracking performance is investigated through simulation and experiments for both quadrature phase-shift keying（QPSK） and 16-QAM signals.The influence of the filter parameters on the static polarization demultiplexing performance and dynamic tracking capability are discussed via simulation.The optimization strategy of the filter parameters in modulation-format-independent scenarios is proposed and simulations are carried out to evaluate the polarization demultiplexing penalty for QPSK,16 QAM,and hybrid QPSK/16 QAM signals.Finally,the proposed decision-free RD-LKF is experimentally compared to the respective algorithms of constant modulus algorithm and multimodulus algorithm for QPSK and 16-QAM and the advantage of ultrafast polarization tracking ability is confirmed.展开更多
It is well known that the solar tracking systems can increase the efficiency of the photovoltaic (PV) panel by about 30 percent. However, these systems require precise control of their components, mainly of the equipm...It is well known that the solar tracking systems can increase the efficiency of the photovoltaic (PV) panel by about 30 percent. However, these systems require precise control of their components, mainly of the equipment’s used for the measurement of energy. In this paper, a metrology analysis is conducted, through of the results obtained by Sunflower prototype. The Sunflower is a solar tracking system developed by H. J. Loschi. A tracking system through a microcontrolled timing logic, sending commands to a linear actuator that moves the system. The deductions, based on in research trials, confirms that the Sunflower prototype is more efficient in relation to fixed PV panels, it is possible to observe the difference in the efficiency of 31%, with a variation of ±0.8% (that depends the solar irradiation). The main purpose of this paper is to attest to the quality of the measurements carried out during the performance tests of the Sunflower prototype, evaluating the uncertainty of measurements collected through the measurements equipment, and, introducing methods to minimize uncertainties of measurement equipment in the PV systems.展开更多
In the era of the new media,the construction of multimodal climate economy discourse has become an effective tool to address climate change,a crucial issue of human society,which is vital to the present and future of ...In the era of the new media,the construction of multimodal climate economy discourse has become an effective tool to address climate change,a crucial issue of human society,which is vital to the present and future of human society and thus has been gaining widespread global attention.This study uses visual grammar as the theoretical framework to examine the multimodal discourse of the 2021 National Low Carbon Day publicity film.By using the analysis tools ELAN and Nvivo12,it claims that this promotional film constructs interpersonal,ideational,and textual meaning by utilizing various visual symbolic resources,such as color,perspective,and character manifestation.This study also discovers that the criteria for using cool and warm colors in this promotional film diverge from the earlier conclusions of the new visual grammar.As a result,it is suggested that color analysis should be conducted in conjunction with the actual corpus in the theoretical framework of the new visual grammar.展开更多
Millimeter range signals have been widely used in biology and medicine over the 20-30 years of the last century.At this time in Ukraine have been developed and implemented treatment technologies,the main ones are mill...Millimeter range signals have been widely used in biology and medicine over the 20-30 years of the last century.At this time in Ukraine have been developed and implemented treatment technologies,the main ones are millimeter therapy(MMT),microwave resonance therapy(MRT),information-wave therapy(IWT).The features of this technologies are the use of signals in the frequency band 40-78 GHz with extremely low signal levels-10-9-10-11 W/cm2,the parameters are immanent to own communication signals of the human body.The author of the article attempts to conduct a combined analysis of hardware and software of these treatment technologies with mm-band signals.Thus the specialized equipment used for the treatment,technologies and the statistical results of its use for various diseases are considered.The problems of metrological support and measuring the weak signals of the mm range are proposed to solve by creating highly sensitive radiometric systems.The results of measurements of microwave signals of natural objects that can be used for physiotherapy and physical bodies that are in contact with or in human environment are submitted.Promising areas of the using the highly sensitive radiometric measurement equipment for research in biology and medicine are presented.展开更多
文摘Objective To provide new ideas for the effective treatment of many serious diseases and to solve many major medical problems faced by mankind.Methods In this paper,the invention patents in the field of stem cells in China from 2010 to 2020 were taken as the research object,and the technology status quo in the field of stem cells was analyzed to predict the future development direction through quantitative analysis method.Results and Conclusion The development of stem cell technology in China is in a period of growth with great potential.Therefore,it is necessary to strengthen the ability of Chinese universities to combine production,education and research.Nowadays,the hotspots in stem cell technology are using culture medium to improve cell proliferation ability,production efficiency,and to induce differentiated cells.Meanwhile,the production efficiency of embryonic stem cells should be improved,and the immunomodulatory effect of embryonic stem cells can be exerted to screen drugs.Besides,the function of hematopoietic stem cells should be enhanced and apply mesenchymal cells in therapy.Since the potential technological gaps are the improvement of therapy,induced differentiation and efficiency of pluripotent stem cells,the improvement of progenitor cell proliferation and the control of cost,we should strengthen R&D investment in culture medium,embryonic stem cells and other technical fields,and achieve the purpose of reducing R&D costs and improving R&D efficiency.
基金supported by National Key Research and Development Program of China(Grant No.2017YFF0205600)。
文摘Pavement distress detection(PDD)plays a vital role in planning timely pavement maintenance that improves pavement service life.In order to promote the development of PDD technologies and find out the insufficiencies in PDD field,this paper reviews the technical development history and characteristics of various PDD technologies,which contributes to the current state of research on PDD.First,processes of PDD are briefly introduced.The PDD technologies based on radar ranging,2D image,laser ranging and 3 D structured light are illustrated.The newest 3D PDD technology based on interference fringe,which has better accuracy,is in progress.The principles and implementation processes of these methods are discussed.Finally,the shortcomings of these technologies in the field of PDD are concluded.Recommendations for future development are provided.The research results show that various PDD technologies have been continuously improved,developed,over the past decade,and have achieved a series of results.However,the measurements from existing PDD technologies can not be metrological traced to acquire the true dimensions of pavement distresses.The lack of metrological traceability technology in the PDD field needs to be further solved.In order to achieve more accurate and efficient PDD,the metrological traceability technology of PDD systems has become the future development direction in this field.
文摘With the theory and methods of system engineering,new ideas and structure system are used to disuses how to establish modern metrological system in this paper.It deeply studies value transmit system; metrological information system; enterprise measurement assurance system,and discusses that the use of system methods can spur modern metrology on to great development.
文摘This paper, first, presents the main points of national policies and regulations, and a series of technical standards concerning legal metrological units, and bries the importance and urgency of using legal metrological unit in the seismological system. Secondly, it examined the present situation in using legal metrological unit by checking six selected kinds of Seismological periodicals against national standard and provided in the form of tables typical error-correcting examples in using legal metrological unit for the responsibles (authors) and editorial departments.Finally,based on statistic, it analysed the causes for the existing problems and offered proposals for emphasizing the use of legal metrological units in the seismological system.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFF0218403)the Basic Scientific Research Operating Fund of NIM(Grant No.AKYZD2007-1)。
文摘The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibrate the corresponding instruments.We develop a new reference material with nominal CDs of 160 nm,80 nm,and 40 nm.The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology(NIM)in China.Also,we propose a new characterization method for the precise measurement of CD values.After filtering and leveling the intensity profiles,the line features are characterized by the combination model of the Gaussian and Lorentz functions.The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm.Then the width of the two edges at the half intensity position is regarded as the standard CD value.Finally,the measurement results are evaluated in terms of the sample,instrument,algorithm,and repeatability.The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.
基金supported by the German Federal Ministry of Economics and Technology under Grant No.16IN0594(DEMAX project)the ARTE-MIS-JU and the Participating Member States under Grant No.100266(ME~3GAS project)the European Commission under Grant No.FP7-SME-2011-286753(WiMBex project)
文摘Wireless M-Bus according to EN-13757-4 is a major contender for local metrological network （LMN） in smart metering and smart grid applications, as it holds the promise of flexible and optimized solutions. It enjoys wide popularity in continental Europe, but increasingly in many other regions of the world. However, Wireless M-Bus is characterized by a wide variety of different operation modes （C-, F-, N-, P-, Q-, R-, S-, and T-modes）, which work in different frequency bands （i.e., 868 MHz, 433 MHz, and 169 MHz）. Its application layer can be enhanced by extensions, being defined from vendor alliances, like the Open Metering System （OMS） Group, or from national bodies.
基金supported by the National Natural Science Foundation of China(Nos.61205046,61401020,and 61575051)the Shenzhen Municipal Science and Technology Plan Project(Nos.JCYJ20150327155705357,KQCX2015032409501296,and JSGG20150529153336124,and JCYJ20150529114045265)the Hong Kong Government General Research Fund(GRF)(No.PolyU152079/14E)
文摘We propose and experimentally demonstrate a universal and blind polarization-state tracking scheme for M-quadrature amplitude modulation（QAM） signals based on a decision-free radius-directed linear Kalman filter（RD-LKF）.The polarization tracking performance is investigated through simulation and experiments for both quadrature phase-shift keying（QPSK） and 16-QAM signals.The influence of the filter parameters on the static polarization demultiplexing performance and dynamic tracking capability are discussed via simulation.The optimization strategy of the filter parameters in modulation-format-independent scenarios is proposed and simulations are carried out to evaluate the polarization demultiplexing penalty for QPSK,16 QAM,and hybrid QPSK/16 QAM signals.Finally,the proposed decision-free RD-LKF is experimentally compared to the respective algorithms of constant modulus algorithm and multimodulus algorithm for QPSK and 16-QAM and the advantage of ultrafast polarization tracking ability is confirmed.
文摘It is well known that the solar tracking systems can increase the efficiency of the photovoltaic (PV) panel by about 30 percent. However, these systems require precise control of their components, mainly of the equipment’s used for the measurement of energy. In this paper, a metrology analysis is conducted, through of the results obtained by Sunflower prototype. The Sunflower is a solar tracking system developed by H. J. Loschi. A tracking system through a microcontrolled timing logic, sending commands to a linear actuator that moves the system. The deductions, based on in research trials, confirms that the Sunflower prototype is more efficient in relation to fixed PV panels, it is possible to observe the difference in the efficiency of 31%, with a variation of ±0.8% (that depends the solar irradiation). The main purpose of this paper is to attest to the quality of the measurements carried out during the performance tests of the Sunflower prototype, evaluating the uncertainty of measurements collected through the measurements equipment, and, introducing methods to minimize uncertainties of measurement equipment in the PV systems.
基金Funding information:Funded by the 11th“China Foreign Language Education Fund”Project(“中国外语教育基金”项目)“Research on the international communication ability of college students to tell China’s stories in foreign languages in the era of digital intelligence”(数智时代大学生用外语讲好中国故事的国际传播能力研究)(ZGWYJYJJ11Z006)。
文摘In the era of the new media,the construction of multimodal climate economy discourse has become an effective tool to address climate change,a crucial issue of human society,which is vital to the present and future of human society and thus has been gaining widespread global attention.This study uses visual grammar as the theoretical framework to examine the multimodal discourse of the 2021 National Low Carbon Day publicity film.By using the analysis tools ELAN and Nvivo12,it claims that this promotional film constructs interpersonal,ideational,and textual meaning by utilizing various visual symbolic resources,such as color,perspective,and character manifestation.This study also discovers that the criteria for using cool and warm colors in this promotional film diverge from the earlier conclusions of the new visual grammar.As a result,it is suggested that color analysis should be conducted in conjunction with the actual corpus in the theoretical framework of the new visual grammar.
文摘Millimeter range signals have been widely used in biology and medicine over the 20-30 years of the last century.At this time in Ukraine have been developed and implemented treatment technologies,the main ones are millimeter therapy(MMT),microwave resonance therapy(MRT),information-wave therapy(IWT).The features of this technologies are the use of signals in the frequency band 40-78 GHz with extremely low signal levels-10-9-10-11 W/cm2,the parameters are immanent to own communication signals of the human body.The author of the article attempts to conduct a combined analysis of hardware and software of these treatment technologies with mm-band signals.Thus the specialized equipment used for the treatment,technologies and the statistical results of its use for various diseases are considered.The problems of metrological support and measuring the weak signals of the mm range are proposed to solve by creating highly sensitive radiometric systems.The results of measurements of microwave signals of natural objects that can be used for physiotherapy and physical bodies that are in contact with or in human environment are submitted.Promising areas of the using the highly sensitive radiometric measurement equipment for research in biology and medicine are presented.
