The construction of a municipal industry-education consortium is one of the important measures for the“one body,two wings,and five key points”reform of China’s modern vocational education system in the new era.It i...The construction of a municipal industry-education consortium is one of the important measures for the“one body,two wings,and five key points”reform of China’s modern vocational education system in the new era.It is of great significance for the integrated promotion of the three major national strategies of education,technology,and talent.Exploring the construction path of municipal industry-education consortia from the perspective of“four-chain integration”is essential for improving the quality of vocational education talents,comprehensively promoting local economic and social development,and serving the national strategy of revitalizing the country through science and education.The new generation of information technology industry-education consortium in Chengdu actively explores new paths of industry-education integration,science-education integration,and vocational-education integration.It has formed a“park+alliance”to establish a diversified collaborative construction and management mechanism,a“professional+industry”school-enterprise cooperation to promote industrial transformation and upgrading,a“teaching+research and development”to build an industry-university research innovation platform to empower high-quality development,and a“cultivation+employment”to explore a matrix style talent cultivation model,thus promoting regional governments,industries enterprises,and higher education institutions.Fully leveraging complementary advantages involves capitalizing on the spatial cluster effect.It requires a foundation in the education chain,guided by the industrial chain,activation of the innovation chain,establishment of a talent chain,enhancement of the value chain,and the promotion of a modern vocational education structure.This structure should align with market demand and industry structure,ultimately promoting regional economic and social development.展开更多
Accelerating the construction of modern vocational education groups and promoting the integrated training of secondary vocational,vocational,and undergraduate talents,providing talent support for regional economic dev...Accelerating the construction of modern vocational education groups and promoting the integrated training of secondary vocational,vocational,and undergraduate talents,providing talent support for regional economic development,are inevitable choices to enhance the adaptability of vocational education.Based on the new development and requirements in the new situation,vocational colleges actively explore the path of connecting and cultivating secondary vocational,vocational,and undergraduate talents in accordance with the talent needs of local economic development and industrial system development.The linkage between government,school,and enterprise is established to build a modern vocational education group,aiming to build a professional chain in the industrial chain and promote innovative development of the new industrial system.Relying on the development needs of professional clusters,a multi-level system of connecting and cultivating secondary vocational,vocational,and undergraduate talents is constructed,which is in line with industry and enterprise standards.It is also necessary to build a“post-course competition certification”talent training model for connecting secondary vocational,vocational,and undergraduate students,rely on the advantages of multiple schools and enterprises,establish a platform for integrating industry and education,and innovate the evaluation system for connecting secondary vocational,vocational,and undergraduate students.展开更多
Terahertz(THz) and millimeter Wave(mmWave) have been considered as potential frequency bands for 6G cellular systems to meet the need of ultra-high data rates. However, indoor communications could be blocked in THz/mm...Terahertz(THz) and millimeter Wave(mmWave) have been considered as potential frequency bands for 6G cellular systems to meet the need of ultra-high data rates. However, indoor communications could be blocked in THz/mmW cellular systems due to the high free-space propagation loss. Deploying a large number of small base stations indoors has been considered as a promising solution for solving indoor coverage problems. However, base station dense deployment leads to a significant increase in system energy consumption. In this paper, we develop a novel ultra-efficient energy-saving mechanism with the aim of reducing energy consumption in 6G distributed indoor base station scenarios. Unlike the existing relevant protocol framework of 3GPP, which operates the cellular system based on constant system signaling messages(including cell ID, cell reselection information, etc.), the proposed mechanism eliminates the need for system messages. The intuition comes from the observation that the probability of having no users within the coverage area of an indoor base station is high, hence continuously sending system messages to guarantee the quality of service is unnecessary in indoor scenarios. Specifically, we design a dedicated beacon signal to detect whether there are users in the coverage area of the base station and switch off the main communication module when there are no active users for energy saving. The beacon frame structure is carefully designed based on the existing 3GPP specifications with minimal protocol modifications, and the protocol parameters involved are optimized. Simulation results show that the proposed mechanism can reduce the system energy from the order of tens of watts to the order of hundreds of milliwatts. Compared to traditional energy-saving schemes, the proposed mechanism achieves an average energy-saving gain of 58%, with a peak energy-saving gain of 90%.展开更多
In this work,a frame work for time-varying channel modeling and simulation is proposed by using neural network(NN)to overcome the shortcomings in geometry based stochastic model(GBSM)and simulation approach.Two NN mod...In this work,a frame work for time-varying channel modeling and simulation is proposed by using neural network(NN)to overcome the shortcomings in geometry based stochastic model(GBSM)and simulation approach.Two NN models are developed for modeling of path loss together with shadow fading(SF)and joint small scale channel parameters.The NN models can predict path loss plus SF and small scale channel parameters accurately compared with measurement at 26 GHz performed in an outdoor microcell.The time-varying path loss and small scale channel parameters generated by the NN models are proposed to replace the empirical path loss and channel parameter random numbers in GBSM-based framework to playback the measured channel and match with its environment.Moreover,the sparse feature of clusters,delay and angular spread,channel capacity are investigated by a virtual array measurement at 28 GHz in a large waiting hall.展开更多
The increasing demands for wearable electronics have stimulated the rapid development of flexible energy storage devices.MXenes are considered as promising flexible electrodes due to the ultrahigh volumetric specific ...The increasing demands for wearable electronics have stimulated the rapid development of flexible energy storage devices.MXenes are considered as promising flexible electrodes due to the ultrahigh volumetric specific capacitance,metallic conductivity,superior hydrophily,and rich surface chemistry.展开更多
To investigate whether transcription of hepatitis B virus （HBV） gene occurs in human sperm, total RNA was extracted from sperm of patients with chronic HBV infection （test-I）, from donor sperm transfected with a p...To investigate whether transcription of hepatitis B virus （HBV） gene occurs in human sperm, total RNA was extracted from sperm of patients with chronic HBV infection （test-I）, from donor sperm transfected with a plasmid containing the full-length HBV genome （test-2）, and from nontransfected donor sperm （control）, used as the template for reverse transcription-polymerase chain reaction （RT-PCR）. Positive bands for HBV DNA were observed in the test groups but not in the control. Next, to identify the role of host genes in regulating viral gene transcription in sperm, total RNA was extracted from 2-cell embryos derived from hamster oocytes fertilized in vitro by HBV-transfected （test） or nontransfected （control） human sperm and successively subjected to SMART-PCR, suppression subtractive hybridization, T/A cloning, bacterial amplification, microarray hybridization, sequencing and the Basic Local Alignment Search Tool （BLAST） search to isolate differentially expressed genes. Twenty-nine sequences showing significant identity to five human gene families were identified, with chorionic somatomammotropin hormone 2 （CSH2）, eukaryotic translation initiation factor 4 gamma 2 （EIF4G2）, pterin-4 alpha-carbinolamine dehydratase 2 （PCBD2）, pregnancy-specific beta-l-glycoprotein 4 （PSG4） and titin （TTN） selected to represent target genes. Using real-time quantitative RT-PCR （qRT-PCR）, when CSH2 and PCBD2 （or EIF4G2, PSG4 and TTN） were silenced by RNA interference, transcriptional levels of HBV s and x genes significantly decreased （or increased） （P 〈 0.05）. Silencing of a control gene in sperm did not significantly change transcription of HBV s and x genes （P 〉 0.05）. This study provides the first experimental evidence that transcription of HBV genes occurs in human sperm and is regulated by host genes.展开更多
This paper proposes a mode selection scheme to improve the spectral efficiency for coordinated multi-point(CoMP) transmission with phase synchronization errors(PSE). Upper bounds of average achievable rate for differe...This paper proposes a mode selection scheme to improve the spectral efficiency for coordinated multi-point(CoMP) transmission with phase synchronization errors(PSE). Upper bounds of average achievable rate for different CoMP transmission modes, such as coordinated beamforming(CB) and joint processing(JP), are derived by random matrix theory and asymptotic mathematical approximation. According to these upper bounds, the proposed scheme switches CoMP transmission mode between CB and JP adaptively to enhance the average achievable rate. Simulation results show that these upper bounds agree well with the average achievable rates for both JP and CB, and the proposed scheme outperforms traditional single mode CoMP transmission when PSE exist.展开更多
Auxetic mechanical metamaterials are artificially architected materials that possess negative Poisson’s ratio,demonstrating transversal contracting deformation under external vertical compression loading.Their physic...Auxetic mechanical metamaterials are artificially architected materials that possess negative Poisson’s ratio,demonstrating transversal contracting deformation under external vertical compression loading.Their physical properties are mainly determined by spatial topological configurations.Traditionally,classical auxetic mechanical metamaterials exhibit relatively lower mechanical stiffness,compared to classic stretching dominated architectures.Nevertheless,in recent years,several novel auxetic mechanical metamaterials with high stiffness have been designed and proposed for energy absorption,load-bearing,and thermal-mechanical coupling applications.In this paper,mechanical design methods for designing auxetic structures with soft and stiff mechanical behavior are summarized and classified.For soft auxetic mechanical metamaterials,classic methods,such as using soft basic material,hierarchical design,tensile braided design,and curved ribs,are proposed.In comparison,for stiff auxetic mechanical metamaterials,design schemes,such as hard base material,hierarchical design,composite design,and adding additional load-bearing ribs,are proposed.Multi-functional applications of soft and stiff auxetic mechanical metamaterials are then reviewed.We hope this study could provide some guidelines for designing programmed auxetics with specified mechanical stiffness and deformation abilities according to demand.展开更多
BACKGROUND Pneumothorax is one of the most common causes of acute dyspnea.In patients under general anesthesia,the symptoms may not be obvious,which may delay diagnosis and treatment.Computed tomography is the gold st...BACKGROUND Pneumothorax is one of the most common causes of acute dyspnea.In patients under general anesthesia,the symptoms may not be obvious,which may delay diagnosis and treatment.Computed tomography is the gold standard for the diagnosis of pneumothorax,but is not suitable for rapid diagnosis of this complication.In contrast,lung ultrasonography can provide rapid diagnosis and treatment of pneumothorax.CASE SUMMARY The patient was a 53-year-old man admitted for rupture of the spleen caused by an accidental fall and emergency splenectomy was planned.Anesthesia was induced,and tracheal intubation was performed successfully with a video laryngoscope.About 2 min after tracheal intubation,the airway peak pressure increased to 50 cm H2O and the oxygen saturation dropped to 70%.According to the BLUE protocol,a recommended area of the chest was scanned by ultrasound.The pleural slide sign disappeared and obvious parallel line sign could be seen in the left lung.The boundary of pneumothorax(lung points)were rapidly confirmed by ultrasound.To avoid lung injury,a closed thoracic drainage tube was placed in the involved area.On day 9 after surgery,the patient was discharged from the hospital without any complications.CONCLUSION Perioperative pneumothorax is rare but dangerous.It can be rapidly diagnosed and treated with ultrasound guidance.展开更多
The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based ...The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based cutting fluid accounts for more than 90%of the consumption of cutting fluid.However,long-term recycling of water-based cutting fluid could easily cause deterioration,and the breeding of bacteria could cause the cutting fluid to fail,increase manufacturing costs,and even endanger the health of workers.Traditional bactericides could improve the biological stability of cutting fluids,but they are toxic to the environment and do not conform to the development trend of low-carbon manufacturing.Low-carbon manufacturing is inevitable and the direction of sustainable manufacturing.The use of nanomaterials,transition metal complexes,and physical sterilization methods on the bacterial cell membrane and genetic material could effectively solve this problem.In this article,the mechanism of action of additives and microbial metabolites was first analyzed.Then,the denaturation mechanism of traditional bactericides on the target protein and the effect of sterilization efficiency were summarized.Further,the mechanism of nanomaterials disrupting cell membrane potential was discussed.The effects of lipophilicity and the atomic number of transition metal complexes on cell membrane penetration were also summarized,and the effects of ultraviolet rays and ozone on the destruction of bacterial genetic material were reviewed.In other words,the bactericidal performance,hazard,degradability,and economics of various sterilization methods were comprehensively evaluated,and the potential development direction of improving the biological stability of cutting fluid was proposed.展开更多
First of all a simple and practical rectangular transform is given,and then thevector quantization technique which is rapidly developing recently is introduced.We combinethe rectangular transform with vector quantizat...First of all a simple and practical rectangular transform is given,and then thevector quantization technique which is rapidly developing recently is introduced.We combinethe rectangular transform with vector quantization technique for image data compression.Thecombination cuts down the dimensions of vector coding.The size of the codebook can reasonablybe reduced.This method can reduce the computation complexity and pick up the vector codingprocess.Experiments using image processing system show that this method is very effective inthe field of image data compression.展开更多
Channel prediction is critical to address the channel aging issue in mobile scenarios.Existing channel prediction techniques are mainly designed for discrete channel prediction,which can only predict the future channe...Channel prediction is critical to address the channel aging issue in mobile scenarios.Existing channel prediction techniques are mainly designed for discrete channel prediction,which can only predict the future channel in a fixed time slot per frame,while the other intra-frame channels are usually recovered by interpolation.However,these approaches suffer from a serious interpolation loss,especially for mobile millimeter-wave communications.To solve this challenging problem,we propose a tensor neural ordinary differential equation(TN-ODE)based continuous-time channel prediction scheme to realize the direct prediction of intra-frame channels.Specifically,inspired by the recently developed continuous mapping model named neural ODE in the field of machine learning,we first utilize the neural ODE model to predict future continuous-time channels.To improve the channel prediction accuracy and reduce computational complexity,we then propose the TN-ODE scheme to learn the structural characteristics of the high-dimensional channel by low-dimensional learnable transform.Simulation results show that the proposed scheme is able to achieve higher intra-frame channel prediction accuracy than existing schemes.展开更多
The development mechanism and mode and the new technical characteristics of the modern cutting technology are studied and analyzed. It is presented that to speed up the development of cutting technology and fully use ...The development mechanism and mode and the new technical characteristics of the modern cutting technology are studied and analyzed. It is presented that to speed up the development of cutting technology and fully use the good-quality technical resource of cutting tool have the significant meaning for construction of powerful manufacturing industry of China.展开更多
It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet...It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet the high demand of cooling and lubrication due to high heat generation during machining.Nano-biolubricants,especially non-toxic carbon group nano-enhancers(CGNs)are used,can solve this technical bottleneck.However,the machining mechanisms under lubrication of CGNs are unclear at complex interface between tool and workpiece,which characterized by high temperature,pressure,and speed,limited its application in factories and necessitates in-depth understanding.To fill this gap,this study concentrates on the comprehensive quantitative assessment of tribological characteristics based on force,tool wear,chip,and surface integrity in titanium alloy and nickel alloy machining and attempts to answer mechanisms systematically.First,to establish evaluation standard,the cutting mechanisms and performance improvement behavior covering antifriction,antiwear,tool failure,material removal,and surface formation of MQL were revealed.Second,the unique film formation and lubrication behaviors of CGNs in MQL turning,milling,and grinding are concluded.The influence law of molecular structure and micromorphology of CGNs was also answered and optimized options were recommended by considering diverse boundary conditions.Finally,in view of CGNs limitations in MQL,the future development direction is proposed,which needs to be improved in thermal stability of lubricant,activity of CGNs,controllable atomization and transportation methods,and intelligent formation of processing technology solutions.展开更多
The delivery of targeted family education guidance services is essential for establishing a three-in-one education model that encompasses families,schools,and communities.It is also the key to creating a favorable edu...The delivery of targeted family education guidance services is essential for establishing a three-in-one education model that encompasses families,schools,and communities.It is also the key to creating a favorable educational environment that promotes the comprehensive and healthy development of individual students.To gain a comprehensive understanding of family education characteristics and trends in Chinese counties,accurately tap into the educational needs of parents,and effectively identify strengths and weaknesses in family education guidance services,this paper employed a quantitative research method based on a questionnaire survey and interview data from J district of C city after years of continuous monitoring of the quality of family education in the area,aiming to explore these issues and put forward several suggestions for improvement.The results indicate that the family learning environment and atmosphere in the district are generally favorable,while parental educational competence requires further improvement.Parents express a strong desire for interactive,systematic,and fragmented family education guidance from schools.Most parents acknowledge the significance of receiving guidance on family education,yet they are disinclined to actively engage in learning-related activities.While the operational mechanisms of county-level family education guidance services have been continuously improved,there is a need for greater overall coordination.Furthermore,the potential of school-led family education guidance services has yet to be fully tapped,and the scientific and professional standards of such guidance need to be further enhanced.Based on the aforementioned findings,we propose recommendations for improvement.Using J district’s effective improvement practices in management,curriculum,and teams as an example,we intend to explore practical ways to promote county-level family education guidance services and provide a valuable reference for the establishment of a comprehensive and effective system to improve such services.展开更多
Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been report...Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been reported,the development of H2O2 ratiometric fluorescent probe with large Stokes shift remains rather limited.Such probes have shown distinct advantages,such as minimized interference from environment and improved signal-to noise ratio.In this work,we reported a new pyrene-based compound Py-VPB as H2O2 fluorescent probe in vitro.The probe demonstrated ratiometric detection behavior,large Stokes shift and large emission shift.In addition,the probe showed high sensitivity and selectivity towards H2O2 in vitro.Based on these excellent properties,we successfully applied Py-VPB to the visualization of exogenous and endogenous H2O2 in living cells.Cell imaging study also showed that our probe was localized in the mitochondria.We envision that the probe can provide a useful tool for unmasking the biological roles of mitochondrial H2O2 in living systems.展开更多
This paper constructs a feasible framework of new infrastructure of smart campus guided by the industry requirements for the construction of new infrastructure of smart campus and based on the technical cooperation of...This paper constructs a feasible framework of new infrastructure of smart campus guided by the industry requirements for the construction of new infrastructure of smart campus and based on the technical cooperation of 5G+ABCDNETS.This paper puts forward the deployment parameter table of 5G hybrid private network in the basic network around 3 sub items and 9 construction environments.We designed the specific deployment links of intelligent laboratory,security supervision and scientific research collaboration supported by 14 key technologies such as heterogeneous computing in ABCDNETS,taking the sub item of“smart scientific research facilities”as an example.The research findings of this paper provide preliminary exploration for promoting the implementation of technology in the six construction directions of new infrastructure for education.展开更多
Amorphous/nanocrystalline dual-phase structures have recently emerged as an effective way for over-coming the strength-ductility trade-offand breaking the limitation of the reverse Hall-Petch effect.Here,we proposed a...Amorphous/nanocrystalline dual-phase structures have recently emerged as an effective way for over-coming the strength-ductility trade-offand breaking the limitation of the reverse Hall-Petch effect.Here,we proposed a new strategy to develop a hierarchical and interconnected amorphous-crystalline nanocomposite arising from the nanoscale elemental interdiffusion and oxygen adsorption behavior dur-ing thermal treatment processes.The nanocomposite consisted of a three-dimensional(3D)hierarchical network structure where the crystalline phase(Cr-Co-Ni-Al)was embedded into the Al-O-based amor-phous phase network with critical feature sizes encompassing three orders of magnitude(from microm-eter to nanometer scale).It can achieve ultrahigh compression yield strength of-3.6 GPa with large homogeneous deformation of over 50%strain.The massive interstitial atoms induced lattice distortion and hierarchical amorphous phase boundary contributed to the strength improvement.in situ Uniaxial compression inside a transmission electron microscope(TEM)revealed that the exceptional deformability of the nanocomposites resulted from the homogenous plastic flow of nano-sized amorphous phase and the plastic co-deformation behavior restricted by the nano-architected dual-phase interface.The proposed dual-phase synthesis approach can outperform conventional nanolaminates design strategies in terms of the mechanical properties achievable while providing a pathway to easily tune the microstructure of these nanolaminates.展开更多
The quality indicators of cotton will change during storage.Taking the 5.89 million t of Xinjiang cotton from 2016 to 2021 as a sample,this paper analyzed the main fiber quality indicator data of warehouse-in and ware...The quality indicators of cotton will change during storage.Taking the 5.89 million t of Xinjiang cotton from 2016 to 2021 as a sample,this paper analyzed the main fiber quality indicator data of warehouse-in and warehouse-out cotton for storage of 1.5,3.0,4.0,5.0,6.0,and 7.0 years.It was found that the color grade of cotton decreased with the extension of storage time.The cotton with storage time of 5.0 years mainly changed from white cotton grade 2 and white cotton grade 3 to light yellow stained cotton grade 1 and yellow stained cotton grade 1.Among them,the increase of light yellow stained cotton grade 1 was the largest,and the change to yellow stained cotton grade 1 was the largest at the storage 6.0-7.0 years.In addition,there were no significant changes in moisture regain,Micronaire value,upper half mean length,length uniformity index and fiber strength.展开更多
基金2022-2024 Sichuan Vocational Education Talent Training and Education and Teaching Reform Research Project:Research and Practice on Comprehensive Education of Digital Media Technology Major"Posts,Courses,Competitions,and Certificates in Higher Vocational Colleges from the Perspective of Talent Chain,Innovation Chain,Education Chain,and Industrial Chain Integration"(Chuanjiaohan[2023]No.100,GZJG2022-107)2023 Sichuan Education and Scientific Research Project Key Project"Based on the Skills Master Studio's'Three-Pairs,Three-Levels,and Four-Integration'Education Path Research and Practice in Digital Media Technology Major in Higher Vocational Education"(Chuanjiaohan[2023]No.478,SCJG23A077)+2 种基金14th Five-Year Plan for Education Information Technology Research in Sichuan Province 2022 Project(DSJ2022100)2022 Chengdu Agricultural College Key Education and Teaching Reform Project(JG-202202-11)Chengdu Philosophy and Social Sciences Key Research Base:Chengdu Craftsman Culture Research Center Project(2023ZC03)。
文摘The construction of a municipal industry-education consortium is one of the important measures for the“one body,two wings,and five key points”reform of China’s modern vocational education system in the new era.It is of great significance for the integrated promotion of the three major national strategies of education,technology,and talent.Exploring the construction path of municipal industry-education consortia from the perspective of“four-chain integration”is essential for improving the quality of vocational education talents,comprehensively promoting local economic and social development,and serving the national strategy of revitalizing the country through science and education.The new generation of information technology industry-education consortium in Chengdu actively explores new paths of industry-education integration,science-education integration,and vocational-education integration.It has formed a“park+alliance”to establish a diversified collaborative construction and management mechanism,a“professional+industry”school-enterprise cooperation to promote industrial transformation and upgrading,a“teaching+research and development”to build an industry-university research innovation platform to empower high-quality development,and a“cultivation+employment”to explore a matrix style talent cultivation model,thus promoting regional governments,industries enterprises,and higher education institutions.Fully leveraging complementary advantages involves capitalizing on the spatial cluster effect.It requires a foundation in the education chain,guided by the industrial chain,activation of the innovation chain,establishment of a talent chain,enhancement of the value chain,and the promotion of a modern vocational education structure.This structure should align with market demand and industry structure,ultimately promoting regional economic and social development.
基金2022-2024 Sichuan Provincial Department of Education Vocational Education Talent Training and Education Reform Research Project General Project(Project number:Chuanjiaohan[2023]No.100,GZJG2022-107,Host:Li Hui):Comprehensive Education Research and Practice of“Post-Course Competition Certificate”in Higher Vocational Digital Media Majors from the Perspective of“Four Chains”Integration2023 Sichuan Provincial Education and Research Project(Key Project)(Project number:Chuanjiaohan[2023]-67,Host:Li Hui):Based on the"Three Double,Three Stage,and Four Integration"Vocational Digital Media Professional Education Path Research and Practice of the Skills Master Studio+2 种基金2022 Chengdu Agricultural College Key Education and Teaching Reform Project(JG-202202-11)The Education Reform Project of Chengdu Agricultural College in 2021(21JG-29)The 2022 Chengdu Education and Research Planning Project(CY2022ZZ31)。
文摘Accelerating the construction of modern vocational education groups and promoting the integrated training of secondary vocational,vocational,and undergraduate talents,providing talent support for regional economic development,are inevitable choices to enhance the adaptability of vocational education.Based on the new development and requirements in the new situation,vocational colleges actively explore the path of connecting and cultivating secondary vocational,vocational,and undergraduate talents in accordance with the talent needs of local economic development and industrial system development.The linkage between government,school,and enterprise is established to build a modern vocational education group,aiming to build a professional chain in the industrial chain and promote innovative development of the new industrial system.Relying on the development needs of professional clusters,a multi-level system of connecting and cultivating secondary vocational,vocational,and undergraduate talents is constructed,which is in line with industry and enterprise standards.It is also necessary to build a“post-course competition certification”talent training model for connecting secondary vocational,vocational,and undergraduate students,rely on the advantages of multiple schools and enterprises,establish a platform for integrating industry and education,and innovate the evaluation system for connecting secondary vocational,vocational,and undergraduate students.
基金supported by the National Natural Science Foundation of China under Grant No. 62201121the Fundamental Research Funds for Central Universities under Grant No. ZYGX2024XJ070.
文摘Terahertz(THz) and millimeter Wave(mmWave) have been considered as potential frequency bands for 6G cellular systems to meet the need of ultra-high data rates. However, indoor communications could be blocked in THz/mmW cellular systems due to the high free-space propagation loss. Deploying a large number of small base stations indoors has been considered as a promising solution for solving indoor coverage problems. However, base station dense deployment leads to a significant increase in system energy consumption. In this paper, we develop a novel ultra-efficient energy-saving mechanism with the aim of reducing energy consumption in 6G distributed indoor base station scenarios. Unlike the existing relevant protocol framework of 3GPP, which operates the cellular system based on constant system signaling messages(including cell ID, cell reselection information, etc.), the proposed mechanism eliminates the need for system messages. The intuition comes from the observation that the probability of having no users within the coverage area of an indoor base station is high, hence continuously sending system messages to guarantee the quality of service is unnecessary in indoor scenarios. Specifically, we design a dedicated beacon signal to detect whether there are users in the coverage area of the base station and switch off the main communication module when there are no active users for energy saving. The beacon frame structure is carefully designed based on the existing 3GPP specifications with minimal protocol modifications, and the protocol parameters involved are optimized. Simulation results show that the proposed mechanism can reduce the system energy from the order of tens of watts to the order of hundreds of milliwatts. Compared to traditional energy-saving schemes, the proposed mechanism achieves an average energy-saving gain of 58%, with a peak energy-saving gain of 90%.
基金supported by the National Nature Science Foundation of China(NSFC)under grant No.61771194supported by Key Program of Beijing Municipal Natural Science Foundation with No.17L20052
文摘In this work,a frame work for time-varying channel modeling and simulation is proposed by using neural network(NN)to overcome the shortcomings in geometry based stochastic model(GBSM)and simulation approach.Two NN models are developed for modeling of path loss together with shadow fading(SF)and joint small scale channel parameters.The NN models can predict path loss plus SF and small scale channel parameters accurately compared with measurement at 26 GHz performed in an outdoor microcell.The time-varying path loss and small scale channel parameters generated by the NN models are proposed to replace the empirical path loss and channel parameter random numbers in GBSM-based framework to playback the measured channel and match with its environment.Moreover,the sparse feature of clusters,delay and angular spread,channel capacity are investigated by a virtual array measurement at 28 GHz in a large waiting hall.
基金This research was supported by GRF Scheme under Project CityU 11305218The work was also partially sponsored by the project 2017JY0088 supported by Science&Technology Department of Sichuan Provincewas partially supported by the Chengdu Research Institute(2017JY0088),City University of Hong Kong.
文摘The increasing demands for wearable electronics have stimulated the rapid development of flexible energy storage devices.MXenes are considered as promising flexible electrodes due to the ultrahigh volumetric specific capacitance,metallic conductivity,superior hydrophily,and rich surface chemistry.
基金This work was supported by the National Natural Science Foundation of China （No. 30972526） and by the Applied Basic Research Programs of Sichuan Province （No. 20141Y0110）. The authors thank Prof. Stanley Lin for his assistance in revising the final draft of the manuscript and editing for English grammar and syntax.
文摘To investigate whether transcription of hepatitis B virus （HBV） gene occurs in human sperm, total RNA was extracted from sperm of patients with chronic HBV infection （test-I）, from donor sperm transfected with a plasmid containing the full-length HBV genome （test-2）, and from nontransfected donor sperm （control）, used as the template for reverse transcription-polymerase chain reaction （RT-PCR）. Positive bands for HBV DNA were observed in the test groups but not in the control. Next, to identify the role of host genes in regulating viral gene transcription in sperm, total RNA was extracted from 2-cell embryos derived from hamster oocytes fertilized in vitro by HBV-transfected （test） or nontransfected （control） human sperm and successively subjected to SMART-PCR, suppression subtractive hybridization, T/A cloning, bacterial amplification, microarray hybridization, sequencing and the Basic Local Alignment Search Tool （BLAST） search to isolate differentially expressed genes. Twenty-nine sequences showing significant identity to five human gene families were identified, with chorionic somatomammotropin hormone 2 （CSH2）, eukaryotic translation initiation factor 4 gamma 2 （EIF4G2）, pterin-4 alpha-carbinolamine dehydratase 2 （PCBD2）, pregnancy-specific beta-l-glycoprotein 4 （PSG4） and titin （TTN） selected to represent target genes. Using real-time quantitative RT-PCR （qRT-PCR）, when CSH2 and PCBD2 （or EIF4G2, PSG4 and TTN） were silenced by RNA interference, transcriptional levels of HBV s and x genes significantly decreased （or increased） （P 〈 0.05）. Silencing of a control gene in sperm did not significantly change transcription of HBV s and x genes （P 〉 0.05）. This study provides the first experimental evidence that transcription of HBV genes occurs in human sperm and is regulated by host genes.
基金supported in part by National High Technology Research and Development Program Of China(863 Program)under Grant No.2014AA01A704National Natural Science Foundation Of China under Grant No.61101092
文摘This paper proposes a mode selection scheme to improve the spectral efficiency for coordinated multi-point(CoMP) transmission with phase synchronization errors(PSE). Upper bounds of average achievable rate for different CoMP transmission modes, such as coordinated beamforming(CB) and joint processing(JP), are derived by random matrix theory and asymptotic mathematical approximation. According to these upper bounds, the proposed scheme switches CoMP transmission mode between CB and JP adaptively to enhance the average achievable rate. Simulation results show that these upper bounds agree well with the average achievable rates for both JP and CB, and the proposed scheme outperforms traditional single mode CoMP transmission when PSE exist.
基金support from the National Natural Science Foundation of China(Grant No.12102193)Shenzhen-Hong KongMacao Science and Technology Program(Category C)(SGDX2020110309300301)+1 种基金Key R&D Program from the Science and Technology Department of Sichuan Province(Key Science&Technology Project)(No.2022YFSY0001)Changsha Municipal Science and Technology Bureau under the Grant kh2201035.
文摘Auxetic mechanical metamaterials are artificially architected materials that possess negative Poisson’s ratio,demonstrating transversal contracting deformation under external vertical compression loading.Their physical properties are mainly determined by spatial topological configurations.Traditionally,classical auxetic mechanical metamaterials exhibit relatively lower mechanical stiffness,compared to classic stretching dominated architectures.Nevertheless,in recent years,several novel auxetic mechanical metamaterials with high stiffness have been designed and proposed for energy absorption,load-bearing,and thermal-mechanical coupling applications.In this paper,mechanical design methods for designing auxetic structures with soft and stiff mechanical behavior are summarized and classified.For soft auxetic mechanical metamaterials,classic methods,such as using soft basic material,hierarchical design,tensile braided design,and curved ribs,are proposed.In comparison,for stiff auxetic mechanical metamaterials,design schemes,such as hard base material,hierarchical design,composite design,and adding additional load-bearing ribs,are proposed.Multi-functional applications of soft and stiff auxetic mechanical metamaterials are then reviewed.We hope this study could provide some guidelines for designing programmed auxetics with specified mechanical stiffness and deformation abilities according to demand.
文摘BACKGROUND Pneumothorax is one of the most common causes of acute dyspnea.In patients under general anesthesia,the symptoms may not be obvious,which may delay diagnosis and treatment.Computed tomography is the gold standard for the diagnosis of pneumothorax,but is not suitable for rapid diagnosis of this complication.In contrast,lung ultrasonography can provide rapid diagnosis and treatment of pneumothorax.CASE SUMMARY The patient was a 53-year-old man admitted for rupture of the spleen caused by an accidental fall and emergency splenectomy was planned.Anesthesia was induced,and tracheal intubation was performed successfully with a video laryngoscope.About 2 min after tracheal intubation,the airway peak pressure increased to 50 cm H2O and the oxygen saturation dropped to 70%.According to the BLUE protocol,a recommended area of the chest was scanned by ultrasound.The pleural slide sign disappeared and obvious parallel line sign could be seen in the left lung.The boundary of pneumothorax(lung points)were rapidly confirmed by ultrasound.To avoid lung injury,a closed thoracic drainage tube was placed in the involved area.On day 9 after surgery,the patient was discharged from the hospital without any complications.CONCLUSION Perioperative pneumothorax is rare but dangerous.It can be rapidly diagnosed and treated with ultrasound guidance.
基金Supported by National Key Research and Development Program of China(Grant No.2020YFB2010500)National Natural Science Foundation of China(Grant Nos.51975305,51905289)+2 种基金Shandong Provincial Major Science and Technology Innovation Engineering Projects of China(Grant No.2019JZZY020111)Shandong Provincial Natural Science Foundation of China(Grant Nos.ZR2020KE027,ZR2020ME158,ZR2019PEE008)Applied Basic Research Youth Project of Qingdao Science and Technology Plan(Grant No.19-6-2-63-cg)。
文摘The application of cutting fluid in the field of engineering manufacturing has a history of hundreds of years,and it plays a vital role in the processing efficiency and surface quality of parts.Among them,water-based cutting fluid accounts for more than 90%of the consumption of cutting fluid.However,long-term recycling of water-based cutting fluid could easily cause deterioration,and the breeding of bacteria could cause the cutting fluid to fail,increase manufacturing costs,and even endanger the health of workers.Traditional bactericides could improve the biological stability of cutting fluids,but they are toxic to the environment and do not conform to the development trend of low-carbon manufacturing.Low-carbon manufacturing is inevitable and the direction of sustainable manufacturing.The use of nanomaterials,transition metal complexes,and physical sterilization methods on the bacterial cell membrane and genetic material could effectively solve this problem.In this article,the mechanism of action of additives and microbial metabolites was first analyzed.Then,the denaturation mechanism of traditional bactericides on the target protein and the effect of sterilization efficiency were summarized.Further,the mechanism of nanomaterials disrupting cell membrane potential was discussed.The effects of lipophilicity and the atomic number of transition metal complexes on cell membrane penetration were also summarized,and the effects of ultraviolet rays and ozone on the destruction of bacterial genetic material were reviewed.In other words,the bactericidal performance,hazard,degradability,and economics of various sterilization methods were comprehensively evaluated,and the potential development direction of improving the biological stability of cutting fluid was proposed.
文摘First of all a simple and practical rectangular transform is given,and then thevector quantization technique which is rapidly developing recently is introduced.We combinethe rectangular transform with vector quantization technique for image data compression.Thecombination cuts down the dimensions of vector coding.The size of the codebook can reasonablybe reduced.This method can reduce the computation complexity and pick up the vector codingprocess.Experiments using image processing system show that this method is very effective inthe field of image data compression.
基金supported in part by the National Key Research and Development Program of China(Grant No.2020YFB1805005)in part by the National Natural Science Foundation of China(Grant No.62031019)in part by the European Commission through the H2020-MSCA-ITN META WIRELESS Research Project under Grant 956256。
文摘Channel prediction is critical to address the channel aging issue in mobile scenarios.Existing channel prediction techniques are mainly designed for discrete channel prediction,which can only predict the future channel in a fixed time slot per frame,while the other intra-frame channels are usually recovered by interpolation.However,these approaches suffer from a serious interpolation loss,especially for mobile millimeter-wave communications.To solve this challenging problem,we propose a tensor neural ordinary differential equation(TN-ODE)based continuous-time channel prediction scheme to realize the direct prediction of intra-frame channels.Specifically,inspired by the recently developed continuous mapping model named neural ODE in the field of machine learning,we first utilize the neural ODE model to predict future continuous-time channels.To improve the channel prediction accuracy and reduce computational complexity,we then propose the TN-ODE scheme to learn the structural characteristics of the high-dimensional channel by low-dimensional learnable transform.Simulation results show that the proposed scheme is able to achieve higher intra-frame channel prediction accuracy than existing schemes.
文摘The development mechanism and mode and the new technical characteristics of the modern cutting technology are studied and analyzed. It is presented that to speed up the development of cutting technology and fully use the good-quality technical resource of cutting tool have the significant meaning for construction of powerful manufacturing industry of China.
基金supported by the National Natural Science Foundation of China(Nos.51975305 and 51905289)the Major Research Project of Shandong Province(No.2019GGX104040)+2 种基金the Major Science and Technology Innovation Engineering Projects of Shandong Province(No.2019JZZY020111)the Natural Science Foundation of Shandong Province(Nos.ZR2020KE027 and ZR2020ME158)the Applied Basic Research Youth Project of Qingdao science and technology plan(No.19-6-2-63-cg)。
文摘It is an inevitable trend of sustainable manufacturing to replace flood and dry machining with minimum quantity lubrication(MQL)technology.Nevertheless,for aeronautical difficult-tomachine materials,MQL couldn’t meet the high demand of cooling and lubrication due to high heat generation during machining.Nano-biolubricants,especially non-toxic carbon group nano-enhancers(CGNs)are used,can solve this technical bottleneck.However,the machining mechanisms under lubrication of CGNs are unclear at complex interface between tool and workpiece,which characterized by high temperature,pressure,and speed,limited its application in factories and necessitates in-depth understanding.To fill this gap,this study concentrates on the comprehensive quantitative assessment of tribological characteristics based on force,tool wear,chip,and surface integrity in titanium alloy and nickel alloy machining and attempts to answer mechanisms systematically.First,to establish evaluation standard,the cutting mechanisms and performance improvement behavior covering antifriction,antiwear,tool failure,material removal,and surface formation of MQL were revealed.Second,the unique film formation and lubrication behaviors of CGNs in MQL turning,milling,and grinding are concluded.The influence law of molecular structure and micromorphology of CGNs was also answered and optimized options were recommended by considering diverse boundary conditions.Finally,in view of CGNs limitations in MQL,the future development direction is proposed,which needs to be improved in thermal stability of lubricant,activity of CGNs,controllable atomization and transportation methods,and intelligent formation of processing technology solutions.
基金the 2020 Chengdu Key Educational Research Project:“Research on School-led Curriculum Development and Implementation for Enhancing Parental Educational Competence”(CY2020ZE11).
文摘The delivery of targeted family education guidance services is essential for establishing a three-in-one education model that encompasses families,schools,and communities.It is also the key to creating a favorable educational environment that promotes the comprehensive and healthy development of individual students.To gain a comprehensive understanding of family education characteristics and trends in Chinese counties,accurately tap into the educational needs of parents,and effectively identify strengths and weaknesses in family education guidance services,this paper employed a quantitative research method based on a questionnaire survey and interview data from J district of C city after years of continuous monitoring of the quality of family education in the area,aiming to explore these issues and put forward several suggestions for improvement.The results indicate that the family learning environment and atmosphere in the district are generally favorable,while parental educational competence requires further improvement.Parents express a strong desire for interactive,systematic,and fragmented family education guidance from schools.Most parents acknowledge the significance of receiving guidance on family education,yet they are disinclined to actively engage in learning-related activities.While the operational mechanisms of county-level family education guidance services have been continuously improved,there is a need for greater overall coordination.Furthermore,the potential of school-led family education guidance services has yet to be fully tapped,and the scientific and professional standards of such guidance need to be further enhanced.Based on the aforementioned findings,we propose recommendations for improvement.Using J district’s effective improvement practices in management,curriculum,and teams as an example,we intend to explore practical ways to promote county-level family education guidance services and provide a valuable reference for the establishment of a comprehensive and effective system to improve such services.
基金This work was supported by the Science Technology and Innovation Committee of Shenzhen Municipality(JCYJ20180507181654823)the National Natural Science Foundation of China(21778044)and Sichuan Science and Technology Program(2018JY0360).
文摘Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been reported,the development of H2O2 ratiometric fluorescent probe with large Stokes shift remains rather limited.Such probes have shown distinct advantages,such as minimized interference from environment and improved signal-to noise ratio.In this work,we reported a new pyrene-based compound Py-VPB as H2O2 fluorescent probe in vitro.The probe demonstrated ratiometric detection behavior,large Stokes shift and large emission shift.In addition,the probe showed high sensitivity and selectivity towards H2O2 in vitro.Based on these excellent properties,we successfully applied Py-VPB to the visualization of exogenous and endogenous H2O2 in living cells.Cell imaging study also showed that our probe was localized in the mitochondria.We envision that the probe can provide a useful tool for unmasking the biological roles of mitochondrial H2O2 in living systems.
基金2021 National High-end Think Tank Key Research Project“Social Experiment Research on Intelligent Technology Transforming Education”(No.Gb2021013)2020 joint annual project of the Ministry of Education of China and China Mobile:“Research on Educational Experiments with AI”(No.MCM20200404)2020 National Education Science Planning Project“Research on the connotation,standard and evaluation system of students’Information Literacy”(No.ACA200008)。
文摘This paper constructs a feasible framework of new infrastructure of smart campus guided by the industry requirements for the construction of new infrastructure of smart campus and based on the technical cooperation of 5G+ABCDNETS.This paper puts forward the deployment parameter table of 5G hybrid private network in the basic network around 3 sub items and 9 construction environments.We designed the specific deployment links of intelligent laboratory,security supervision and scientific research collaboration supported by 14 key technologies such as heterogeneous computing in ABCDNETS,taking the sub item of“smart scientific research facilities”as an example.The research findings of this paper provide preliminary exploration for promoting the implementation of technology in the six construction directions of new infrastructure for education.
基金supported by Shenzhen-Hong Kong-Macao Science and Technology Program(Category C)(No.SGDX2020110309300301)Key R&D Program from the Science and Technology Department of Sichuan Province(Key Science&Technology Project)(No.2022YFSY0001)+1 种基金Changsha Municipal Science and Technology Bureau(No.kh2201035)the Innovation and Technology Commission of Hong Kong(No.GHP/221/21GD).
文摘Amorphous/nanocrystalline dual-phase structures have recently emerged as an effective way for over-coming the strength-ductility trade-offand breaking the limitation of the reverse Hall-Petch effect.Here,we proposed a new strategy to develop a hierarchical and interconnected amorphous-crystalline nanocomposite arising from the nanoscale elemental interdiffusion and oxygen adsorption behavior dur-ing thermal treatment processes.The nanocomposite consisted of a three-dimensional(3D)hierarchical network structure where the crystalline phase(Cr-Co-Ni-Al)was embedded into the Al-O-based amor-phous phase network with critical feature sizes encompassing three orders of magnitude(from microm-eter to nanometer scale).It can achieve ultrahigh compression yield strength of-3.6 GPa with large homogeneous deformation of over 50%strain.The massive interstitial atoms induced lattice distortion and hierarchical amorphous phase boundary contributed to the strength improvement.in situ Uniaxial compression inside a transmission electron microscope(TEM)revealed that the exceptional deformability of the nanocomposites resulted from the homogenous plastic flow of nano-sized amorphous phase and the plastic co-deformation behavior restricted by the nano-architected dual-phase interface.The proposed dual-phase synthesis approach can outperform conventional nanolaminates design strategies in terms of the mechanical properties achievable while providing a pathway to easily tune the microstructure of these nanolaminates.
基金Supported by 2021 Science and Technology Project of China Grain Reserves Group Limited Company(Sinograin)"Research on Natural Variation Law of Reserve Cotton Quality"(2021-11).
文摘The quality indicators of cotton will change during storage.Taking the 5.89 million t of Xinjiang cotton from 2016 to 2021 as a sample,this paper analyzed the main fiber quality indicator data of warehouse-in and warehouse-out cotton for storage of 1.5,3.0,4.0,5.0,6.0,and 7.0 years.It was found that the color grade of cotton decreased with the extension of storage time.The cotton with storage time of 5.0 years mainly changed from white cotton grade 2 and white cotton grade 3 to light yellow stained cotton grade 1 and yellow stained cotton grade 1.Among them,the increase of light yellow stained cotton grade 1 was the largest,and the change to yellow stained cotton grade 1 was the largest at the storage 6.0-7.0 years.In addition,there were no significant changes in moisture regain,Micronaire value,upper half mean length,length uniformity index and fiber strength.
