Data services,knowledge services,and information services are the core service elements of university libraries in the context of the Double First-Class Initiative.Combined with the current situation of insufficient o...Data services,knowledge services,and information services are the core service elements of university libraries in the context of the Double First-Class Initiative.Combined with the current situation of insufficient overall service capacity of libraries,this paper proposed strategies and implementation paths for optimizing the service system from three aspects:the construction of the professional qualification system for librarians,the establishment of post institutions,and the construction of library culture.Long-term path:putting library human resource management into the legal track,taking the lead in local legislation,and promoting the construction of library legislation and professional qualification certification system;optimizing the personnel system,implementing hierarchical management and classified assessment for professional librarians and auxiliary librarians.Short-term path:intensive post allocation,namely,assigning the core strength in the core post,and tackling the temporary major work combining multiple forces in the form of a"working group";building an open knowledge service ecosystem,accelerate the cross-border integration of libraries and other organizations,and striving to build the core competitiveness of libraries.展开更多
Purpose:This critical policy analysis aims to comprehensively examine the second round of China's first-class discipline development project,commonly known as the Double First-Class Initiative(DFC Initiative or Sh...Purpose:This critical policy analysis aims to comprehensively examine the second round of China's first-class discipline development project,commonly known as the Double First-Class Initiative(DFC Initiative or Shuang Yiliu Jianshe).Design/Approach/Methods:We conducted desk research between May 2022 and December 2023 using relevant policy documents,academic literature,news sources,and commentaries that specifically focused on the second round of the DFC Initiative in China.Employing a critical policy analysis approach,we analyzed the gathered data from three key perspectives:policy as text,policy as discourse,and policy effects(including both first-and second-order effects).Findings:The second round of the DFC Initiative was implemented within the context of strengthened state regulation,prevalent managerialism,and an emphasis on promoting education equality in China's higher education development.A notable shift in structural dynamics occurred between the first and second round.These include the possibility of universities being added to or removed from the official list,increased academic autonomy for selected universities,and the promotion of interdisciplinary research within specific institutions.The implementation of the second round of the DFC Initiative reflects China's commitment to developing an internationalization strategy with Chinese characteristics.This strategy aims to align with China's national strategic needs and position the country as a cooperative partner,promoter,competitor,and potential leader in global scholarship.Originality/Value:By employing a critical policy analysis approach,this study offers a comprehensive examination of the second round of the DFC Initiative in China,contributing to existing knowledge on the development of world-class university policies in the country.展开更多
With the advancement of the“Double First-Class”initiative,universities are increasingly focusing on attracting top-tier talent to enhance faculty quality and strengthen academic disciplines.The blind competition for...With the advancement of the“Double First-Class”initiative,universities are increasingly focusing on attracting top-tier talent to enhance faculty quality and strengthen academic disciplines.The blind competition for high-end talent among universities reflects an overshadowing of academic values by economic considerations,neglecting the growth patterns of top talent and the development laws of higher education.This study investigates and reflects on the real-world challenges of faculty mobility in universities,aiming to provide effective guidance for managing university faculty teams.展开更多
This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”c...This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”construction and university library subject services,the study analyzes the current state of subject services,including resource development,service models,and team building.Drawing on domestic and international case studies,the paper proposes a series of targeted and practical strategies to enhance the quality of subject services in university libraries,thereby providing robust support for the advancement of the“double first-class”initiative.展开更多
Against the background of the“double first-class”construction,the training of innovative graduate talent has become an important issue in higher education.This article discusses the importance of the training of top...Against the background of the“double first-class”construction,the training of innovative graduate talent has become an important issue in higher education.This article discusses the importance of the training of top graduate innovative talent,analyzes the status of the training of top graduate innovative talent at home and abroad,and summarizes the current challenges in the training of graduate innovative talent in China.Lastly,this paper proposes relevant reform suggestions in response to problems in the training of innovative graduate talent,which provides important references for improving the quality of innovative graduate training.展开更多
The reinforced concrete(RC) structural component might suffer a great damage under close-in explosion.Different from distant explosions, blast loads generated by the close-in explosion are non-uniformly distributed on...The reinforced concrete(RC) structural component might suffer a great damage under close-in explosion.Different from distant explosions, blast loads generated by the close-in explosion are non-uniformly distributed on the structural component and may cause both local and structural failure. In this study,an experimental study was conducted to investigate the dynamic responses of RC beams under doubleend-initiated close-in explosions. The experimental results show that the distribution of blast loads generated by the double-end-initiated explosion is much more non-uniform than those generated by single-point detonation, which is caused by the self-Mach-reflection effects. A 3 D finite element model was developed and validated in LS-DYNA by employing the modified K&C model. Intensive numerical calculations were conducted to study the influences of the initiation way, scaled distance and longitudinal reinforcement ratio on the dynamic responses and failure modes of RC beams. Numerical results show that the RC beam suffers greater damage as the cylindrical explosive is detonated at its double ends than the scenario in which the cylindrical explosive is detonated at its central point. RC beams mainly suffer flexural failure and flexure-shear failure under the double-end close-in explosion, and the failure modes of RC beams change from the flexural damage to flexure-shear damage as the scaled distance or the longitudinal reinforcement ratio decreases. The direct shear failure mode is not usually observed in the double-end-initiated explosion, since the intense blast loads is basically concentrated in the midspan of RC beam, which is due to self-Mach-reflection enhancement.展开更多
The effect of initial longitudinal velocity of the tunnelled electron on the non-sequential double ionization （NSDI） process in an elliptically polarized laser field is studied by a semiclassical model. We find that...The effect of initial longitudinal velocity of the tunnelled electron on the non-sequential double ionization （NSDI） process in an elliptically polarized laser field is studied by a semiclassical model. We find that the non-zero initial longitudinal velocity has a suppressing effect on single-return collision （SRC） events in the double ionization process, more specifically, it results in an obvious reduction in the center part of the correlation momentum distributions in the direction of the major polarization axis （z axis） and makes the distribution of single-return collision in the minor polarization axis （x axis） become narrower.展开更多
The formation mechanism of an EFP(explosively formed projectile)using a double curvature liner under the overpressure effect generated by a regular oblique reflection was investigated in this paper.Based on the detona...The formation mechanism of an EFP(explosively formed projectile)using a double curvature liner under the overpressure effect generated by a regular oblique reflection was investigated in this paper.Based on the detonation wave propagation theory,the change of the incident angle of the detonation wave collision at different positions and the distribution area of the overpressure on the surface of the liner were calculated.Three dimensional numerical simulations of the formation process of the EFP with tail.as well as the ability to penetrate 45#steel were performed using LS-DYNA software,and the EFP ve locity,the penetration ability,and the forming were assessed via experiments and x_ray photographs.The experimental results coincides with those of the simulations.Results indicate that the collision of the detonation wave was controlled to be a regular oblique reflection acting on the liner by setting the di-mensions of the unit charge and maintai ning the pressure at the collision point region at more than 2.4 times the CJ detonation when the incident angle approached the cnitical angle.The distance from the liner midline to the boundary of the area within which the pressure ratio of the regular oblique reflection pressure to the qJ detonation pressure was greater than 2.5,2,and 15was approximately 0.66 mm,132 mm,and 3.3 mm,respectively.Itis noted that pressure gradient caused the liner to turn inside out in the middle to form the head of the EFP and close the two tails of the EFP at approximately 120μs.The penetration depth of the EFP into a 45#steel target exceeded 30 mm,and there was radial expansion between the head and tail of the EFP,increasing the penetration resistance of the EFP.Therefore,the structural size of the unit charge and the liner can be further optimized to reduce resist ance to increase the penetration ability of the EFP.展开更多
From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competiti...From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competitiveness of international higher education.In line with the national“double first-class”international development strategy of higher education,based on the cultivation of students’overall quality,the improvement of teachers’professional ability,and the development of school’s improvement of quality and efficiency,we School of Software,Northwestern Polytechnical University,explore new ideas and new measures for the cultivation of international software engineering talents,build a set of international teaching resources construction system,to form a reference standard and scheme for the cultivation of international software engineering talents.At present,we have achieved excellent results.展开更多
To build the top class of higher education by focusing on the goal of the“Double First-Class”,it needs to analyze the defect and deficiency and identify the demand for the training of the talent under the background...To build the top class of higher education by focusing on the goal of the“Double First-Class”,it needs to analyze the defect and deficiency and identify the demand for the training of the talent under the background of“Double First-Class”.Considering of those issues,it is suggested that building the curriculum system scientifically and rationally in following aspects:deepening the training objectives,professionalizing the structure and contents of the curriculum system,optimizing the content,enhancing the construction of practical education system and internationalizing the curriculum system.Also,with those aspects,a reference is provided for the cultivation of talents with innovative consciousness and ability to solve complex engineering problems under the background of the“Double First-Class”construction.展开更多
The construction of“double first-class”universities is the strategic goal of the development of Chinese universities in the new period.On the basis of fully researching the domestic“double first-class”talent train...The construction of“double first-class”universities is the strategic goal of the development of Chinese universities in the new period.On the basis of fully researching the domestic“double first-class”talent training model,this paper builds a new type of talent training model with Chinese characteristics suitable for the“double first-class”development requirements through reference,digestion,comparison and integration,hoping to further improve universities Quality of teaching.展开更多
Throughout the world＇s first-class universities, the university culture is the soul of the universities＇ survival and development, and the cultural competitiveness has become an important symbol of the core competit...Throughout the world＇s first-class universities, the university culture is the soul of the universities＇ survival and development, and the cultural competitiveness has become an important symbol of the core competitiveness of the universities. The first-class university culture is very important to the construction of the ＂double first-class＂. Therefore, our country should bring the university cultural construction into the big pattern of the ＂double first-class＂ construction, guide the construction of the university cultures with the socialist core values, strengthen the cultural confidence, inherit the Chinese excellent traditional cultures, pay attention to the rational exchange of the multicultural cultures, highlight the Chinese characteristics of the first-class university cultures, and realize the dream of the Chinese nation of a power of the higher education.展开更多
Objective: to explore the application effect of virtual medical technology in reproductive teaching under the background of "two-class" universities. Methods: the subjects of the study were the undergraduate...Objective: to explore the application effect of virtual medical technology in reproductive teaching under the background of "two-class" universities. Methods: the subjects of the study were the undergraduate students of clinical medicine in Anhui Medical University. The number is about 80. They were randomly divided into two groups with 40 people in each group. There was no significant difference in learning achievement and intelligence test scores between the two groups. The teaching time and place of the two groups of students are basically the same. All students are required to preview the teaching contents in advance. The traditional teaching group was the control group, while the virtual medical technology teaching group was the research group (P<0.05). Results: after comparison, the study group's students' academic performance was higher than that of the control group, and the study group's students' satisfaction with the teaching methods was higher than that of the control group (P<0.05). Conclusion: the effect of applying virtual medical technology in reproductive teaching is better than that of traditional teaching method. The students' test scores are ideal and they have high recognition of virtual medical technology.展开更多
Pressure-gain combustion has gained attention for airbreathing ramjet engine applications owing to its better thermodynamic efficiency and fuel consumption rate. In contrast with traditional detonation induced by a si...Pressure-gain combustion has gained attention for airbreathing ramjet engine applications owing to its better thermodynamic efficiency and fuel consumption rate. In contrast with traditional detonation induced by a single wedge, the present study considers oblique shock interactions attached to double wedges in a hypersonic combustible flow. The temperature/pressure increases sharply across the interaction zone that initiates an exothermic reaction, finally resulting in an Oblique Detonation Wave(ODW). Compared with the case for a single-wedge ODW, the double-wedge geometry has great potential to control the initiation of the ODW. As a tentative study, two-dimensional compressible Euler equations with a two-step induction-reaction kinetic model are used to solve the detonation dynamics triggered by a double wedge. The effects of the wedge angles and wedge corner locations on the initiation structures are investigated numerically.The results show an ODW complex comprising three Oblique Shock Waves(OSWs), an induction zone, a curved detonation front, and an unburned/low-temperature gas belt close to the surface of the second wedge. Both the increasing wedge angle and downstream wedge corner location lead to an abrupt OSW–ODW transition type, whereas the former corresponds to the shock–shock interaction and the later has a greater effect on the exothermic chemical process. Analysis of the shock polar and flow scale confirms that the OSW–ODW initiation structure mainly depends on the coupling of shocks and heat release in a confined initiation zone.展开更多
The purpose of initial orbit determination,especially in the case of angles-only data for observation,is to obtain an initial estimate that is close enough to the true orbit to enable subsequent precision orbit determ...The purpose of initial orbit determination,especially in the case of angles-only data for observation,is to obtain an initial estimate that is close enough to the true orbit to enable subsequent precision orbit determination processing to be successful.However,the classical angles-only initial orbit determination methods cannot deal with the observation data whose Earth-central angle is larger than 360°.In this paper,an improved double r-iteration initial orbit determination method to deal with the above case is presented to monitor geosynchronous Earth orbit objects for a spacebased surveillance system.Simulation results indicate that the improved double r-iteration method is feasible,and the accuracy of the obtained initial orbit meets the requirements of re-acquiring the object.展开更多
How cells accomplish cell size homeostasis is a fascinating topic, and several cell size regulation mechanisms were proposed: timer, sizer, and adder. Recently the adder model has received a great deal of attention. A...How cells accomplish cell size homeostasis is a fascinating topic, and several cell size regulation mechanisms were proposed: timer, sizer, and adder. Recently the adder model has received a great deal of attention. Adder property was also found in the DNA replication cycle. This paper aims to explain the adder phenomenon both in the division-centric picture and replication-centric picture at the molecular level. We established a self-replication model, and the system reached a steady state quickly based on evolution rules. We collected tens of thousands of cells in the same trajectory and calculated the Pearson correlation coefficient between biological variables to decide which regulatory mechanism was adopted by cells. Our simulation results confirmed the double-adder mechanism. Chromosome replication initiation and cell division control are independent and regulated by respective proteins.Cell size homeostasis originates from division control and has nothing to do with replication initiation control. At a slow growth rate, the deviation from adder toward sizer comes from a significant division protein degradation rate when division protein is auto-inhibited. Our results indicated the two necessary conditions in the double-adder mechanism: one is balanced biosynthesis, and the other is that there is a protein trigger threshold to inspire DNA replication initiation and cell division. Our results give insight to the regulatory mechanism of cell size and instructive to synthetic biology.展开更多
The study object is the angular output velocity of the drive shaft which is made up of two series-wound cross universal joints. We have deduced the function relation between the angular output velocity and initiative ...The study object is the angular output velocity of the drive shaft which is made up of two series-wound cross universal joints. We have deduced the function relation between the angular output velocity and initiative input angle of the drive shaft with double cross universal joints that is based on the calculation formula of the angular output velocity of a single cross universal joint, and by analyzing the relation between the two input angles. By using this function relation, the constant velocity condition of the drive shaft with double cross universal joints＂ is verified. The step-by-step searching algorithm is adopted to obtain the optimal phase angle that leads to the minimum fluctuate index of the angular output velocity in the vary velocity condition. At the same time, we worked out the maximal and minimum value of the angular output velocity, and their initiative input angle. The correctness of the function of the angular output velocity and the step-by-step search algorithm are verified by an ADAMS simulation example.展开更多
文摘Data services,knowledge services,and information services are the core service elements of university libraries in the context of the Double First-Class Initiative.Combined with the current situation of insufficient overall service capacity of libraries,this paper proposed strategies and implementation paths for optimizing the service system from three aspects:the construction of the professional qualification system for librarians,the establishment of post institutions,and the construction of library culture.Long-term path:putting library human resource management into the legal track,taking the lead in local legislation,and promoting the construction of library legislation and professional qualification certification system;optimizing the personnel system,implementing hierarchical management and classified assessment for professional librarians and auxiliary librarians.Short-term path:intensive post allocation,namely,assigning the core strength in the core post,and tackling the temporary major work combining multiple forces in the form of a"working group";building an open knowledge service ecosystem,accelerate the cross-border integration of libraries and other organizations,and striving to build the core competitiveness of libraries.
基金supported by China's National Education Scientific Planning Project(CGA230337).
文摘Purpose:This critical policy analysis aims to comprehensively examine the second round of China's first-class discipline development project,commonly known as the Double First-Class Initiative(DFC Initiative or Shuang Yiliu Jianshe).Design/Approach/Methods:We conducted desk research between May 2022 and December 2023 using relevant policy documents,academic literature,news sources,and commentaries that specifically focused on the second round of the DFC Initiative in China.Employing a critical policy analysis approach,we analyzed the gathered data from three key perspectives:policy as text,policy as discourse,and policy effects(including both first-and second-order effects).Findings:The second round of the DFC Initiative was implemented within the context of strengthened state regulation,prevalent managerialism,and an emphasis on promoting education equality in China's higher education development.A notable shift in structural dynamics occurred between the first and second round.These include the possibility of universities being added to or removed from the official list,increased academic autonomy for selected universities,and the promotion of interdisciplinary research within specific institutions.The implementation of the second round of the DFC Initiative reflects China's commitment to developing an internationalization strategy with Chinese characteristics.This strategy aims to align with China's national strategic needs and position the country as a cooperative partner,promoter,competitor,and potential leader in global scholarship.Originality/Value:By employing a critical policy analysis approach,this study offers a comprehensive examination of the second round of the DFC Initiative in China,contributing to existing knowledge on the development of world-class university policies in the country.
基金Sponsored by the Ministry of Education Humanities and Social Sciences Research Planning Fund Project(22YJA880085)the Project of the Center for Party Political Construction Research,Ministry of Industry and Information Technology(GXZY2245).
文摘With the advancement of the“Double First-Class”initiative,universities are increasingly focusing on attracting top-tier talent to enhance faculty quality and strengthen academic disciplines.The blind competition for high-end talent among universities reflects an overshadowing of academic values by economic considerations,neglecting the growth patterns of top talent and the development laws of higher education.This study investigates and reflects on the real-world challenges of faculty mobility in universities,aiming to provide effective guidance for managing university faculty teams.
基金Heilongjiang Provincial Library Work Committee Project“Double First-Class Construction Research on the Development Strategy of Subject Services in University Libraries”(2024-016-B)。
文摘This paper aims to explore the development strategies for subject services in university libraries within the context of the“double first-class”initiative.By examining the relationship between“double first-class”construction and university library subject services,the study analyzes the current state of subject services,including resource development,service models,and team building.Drawing on domestic and international case studies,the paper proposes a series of targeted and practical strategies to enhance the quality of subject services in university libraries,thereby providing robust support for the advancement of the“double first-class”initiative.
基金Foundation for Development Research of Disciplines of China University of Geosciences(Beijing)(2022XK218 and 2023XK110)。
文摘Against the background of the“double first-class”construction,the training of innovative graduate talent has become an important issue in higher education.This article discusses the importance of the training of top graduate innovative talent,analyzes the status of the training of top graduate innovative talent at home and abroad,and summarizes the current challenges in the training of graduate innovative talent in China.Lastly,this paper proposes relevant reform suggestions in response to problems in the training of innovative graduate talent,which provides important references for improving the quality of innovative graduate training.
基金supported by the National Natural Science Foundations of China(Nos. 51622812, and 51427807)National Basic Research Program of China(No. 2015CB058003)China Postdoctoral Science Foundation(No. 2017M613379)
文摘The reinforced concrete(RC) structural component might suffer a great damage under close-in explosion.Different from distant explosions, blast loads generated by the close-in explosion are non-uniformly distributed on the structural component and may cause both local and structural failure. In this study,an experimental study was conducted to investigate the dynamic responses of RC beams under doubleend-initiated close-in explosions. The experimental results show that the distribution of blast loads generated by the double-end-initiated explosion is much more non-uniform than those generated by single-point detonation, which is caused by the self-Mach-reflection effects. A 3 D finite element model was developed and validated in LS-DYNA by employing the modified K&C model. Intensive numerical calculations were conducted to study the influences of the initiation way, scaled distance and longitudinal reinforcement ratio on the dynamic responses and failure modes of RC beams. Numerical results show that the RC beam suffers greater damage as the cylindrical explosive is detonated at its double ends than the scenario in which the cylindrical explosive is detonated at its central point. RC beams mainly suffer flexural failure and flexure-shear failure under the double-end close-in explosion, and the failure modes of RC beams change from the flexural damage to flexure-shear damage as the scaled distance or the longitudinal reinforcement ratio decreases. The direct shear failure mode is not usually observed in the double-end-initiated explosion, since the intense blast loads is basically concentrated in the midspan of RC beam, which is due to self-Mach-reflection enhancement.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11074026 and 11074155)the Program for New Century Excellent Talents in University of the Ministry of Education of China (Grant No. NCET-08-0883)
文摘The effect of initial longitudinal velocity of the tunnelled electron on the non-sequential double ionization （NSDI） process in an elliptically polarized laser field is studied by a semiclassical model. We find that the non-zero initial longitudinal velocity has a suppressing effect on single-return collision （SRC） events in the double ionization process, more specifically, it results in an obvious reduction in the center part of the correlation momentum distributions in the direction of the major polarization axis （z axis） and makes the distribution of single-return collision in the minor polarization axis （x axis） become narrower.
基金The work presented in this paper has been supported by the science foundation(YT20-01-02)of Nanjing Vocational University of Industry Technology and the National Science Foundation of China under NO.11802141.
文摘The formation mechanism of an EFP(explosively formed projectile)using a double curvature liner under the overpressure effect generated by a regular oblique reflection was investigated in this paper.Based on the detonation wave propagation theory,the change of the incident angle of the detonation wave collision at different positions and the distribution area of the overpressure on the surface of the liner were calculated.Three dimensional numerical simulations of the formation process of the EFP with tail.as well as the ability to penetrate 45#steel were performed using LS-DYNA software,and the EFP ve locity,the penetration ability,and the forming were assessed via experiments and x_ray photographs.The experimental results coincides with those of the simulations.Results indicate that the collision of the detonation wave was controlled to be a regular oblique reflection acting on the liner by setting the di-mensions of the unit charge and maintai ning the pressure at the collision point region at more than 2.4 times the CJ detonation when the incident angle approached the cnitical angle.The distance from the liner midline to the boundary of the area within which the pressure ratio of the regular oblique reflection pressure to the qJ detonation pressure was greater than 2.5,2,and 15was approximately 0.66 mm,132 mm,and 3.3 mm,respectively.Itis noted that pressure gradient caused the liner to turn inside out in the middle to form the head of the EFP and close the two tails of the EFP at approximately 120μs.The penetration depth of the EFP into a 45#steel target exceeded 30 mm,and there was radial expansion between the head and tail of the EFP,increasing the penetration resistance of the EFP.Therefore,the structural size of the unit charge and the liner can be further optimized to reduce resist ance to increase the penetration ability of the EFP.
文摘From the perspective of the development of world-class universities,internationalization is an essential strategic choice and external feature,and also an inevitable choice to improve the discourse power and competitiveness of international higher education.In line with the national“double first-class”international development strategy of higher education,based on the cultivation of students’overall quality,the improvement of teachers’professional ability,and the development of school’s improvement of quality and efficiency,we School of Software,Northwestern Polytechnical University,explore new ideas and new measures for the cultivation of international software engineering talents,build a set of international teaching resources construction system,to form a reference standard and scheme for the cultivation of international software engineering talents.At present,we have achieved excellent results.
文摘To build the top class of higher education by focusing on the goal of the“Double First-Class”,it needs to analyze the defect and deficiency and identify the demand for the training of the talent under the background of“Double First-Class”.Considering of those issues,it is suggested that building the curriculum system scientifically and rationally in following aspects:deepening the training objectives,professionalizing the structure and contents of the curriculum system,optimizing the content,enhancing the construction of practical education system and internationalizing the curriculum system.Also,with those aspects,a reference is provided for the cultivation of talents with innovative consciousness and ability to solve complex engineering problems under the background of the“Double First-Class”construction.
文摘The construction of“double first-class”universities is the strategic goal of the development of Chinese universities in the new period.On the basis of fully researching the domestic“double first-class”talent training model,this paper builds a new type of talent training model with Chinese characteristics suitable for the“double first-class”development requirements through reference,digestion,comparison and integration,hoping to further improve universities Quality of teaching.
文摘Throughout the world＇s first-class universities, the university culture is the soul of the universities＇ survival and development, and the cultural competitiveness has become an important symbol of the core competitiveness of the universities. The first-class university culture is very important to the construction of the ＂double first-class＂. Therefore, our country should bring the university cultural construction into the big pattern of the ＂double first-class＂ construction, guide the construction of the university cultures with the socialist core values, strengthen the cultural confidence, inherit the Chinese excellent traditional cultures, pay attention to the rational exchange of the multicultural cultures, highlight the Chinese characteristics of the first-class university cultures, and realize the dream of the Chinese nation of a power of the higher education.
文摘Objective: to explore the application effect of virtual medical technology in reproductive teaching under the background of "two-class" universities. Methods: the subjects of the study were the undergraduate students of clinical medicine in Anhui Medical University. The number is about 80. They were randomly divided into two groups with 40 people in each group. There was no significant difference in learning achievement and intelligence test scores between the two groups. The teaching time and place of the two groups of students are basically the same. All students are required to preview the teaching contents in advance. The traditional teaching group was the control group, while the virtual medical technology teaching group was the research group (P<0.05). Results: after comparison, the study group's students' academic performance was higher than that of the control group, and the study group's students' satisfaction with the teaching methods was higher than that of the control group (P<0.05). Conclusion: the effect of applying virtual medical technology in reproductive teaching is better than that of traditional teaching method. The students' test scores are ideal and they have high recognition of virtual medical technology.
基金supported by the National Natural Science Foundation of China(No.11822202)。
文摘Pressure-gain combustion has gained attention for airbreathing ramjet engine applications owing to its better thermodynamic efficiency and fuel consumption rate. In contrast with traditional detonation induced by a single wedge, the present study considers oblique shock interactions attached to double wedges in a hypersonic combustible flow. The temperature/pressure increases sharply across the interaction zone that initiates an exothermic reaction, finally resulting in an Oblique Detonation Wave(ODW). Compared with the case for a single-wedge ODW, the double-wedge geometry has great potential to control the initiation of the ODW. As a tentative study, two-dimensional compressible Euler equations with a two-step induction-reaction kinetic model are used to solve the detonation dynamics triggered by a double wedge. The effects of the wedge angles and wedge corner locations on the initiation structures are investigated numerically.The results show an ODW complex comprising three Oblique Shock Waves(OSWs), an induction zone, a curved detonation front, and an unburned/low-temperature gas belt close to the surface of the second wedge. Both the increasing wedge angle and downstream wedge corner location lead to an abrupt OSW–ODW transition type, whereas the former corresponds to the shock–shock interaction and the later has a greater effect on the exothermic chemical process. Analysis of the shock polar and flow scale confirms that the OSW–ODW initiation structure mainly depends on the coupling of shocks and heat release in a confined initiation zone.
文摘The purpose of initial orbit determination,especially in the case of angles-only data for observation,is to obtain an initial estimate that is close enough to the true orbit to enable subsequent precision orbit determination processing to be successful.However,the classical angles-only initial orbit determination methods cannot deal with the observation data whose Earth-central angle is larger than 360°.In this paper,an improved double r-iteration initial orbit determination method to deal with the above case is presented to monitor geosynchronous Earth orbit objects for a spacebased surveillance system.Simulation results indicate that the improved double r-iteration method is feasible,and the accuracy of the obtained initial orbit meets the requirements of re-acquiring the object.
文摘How cells accomplish cell size homeostasis is a fascinating topic, and several cell size regulation mechanisms were proposed: timer, sizer, and adder. Recently the adder model has received a great deal of attention. Adder property was also found in the DNA replication cycle. This paper aims to explain the adder phenomenon both in the division-centric picture and replication-centric picture at the molecular level. We established a self-replication model, and the system reached a steady state quickly based on evolution rules. We collected tens of thousands of cells in the same trajectory and calculated the Pearson correlation coefficient between biological variables to decide which regulatory mechanism was adopted by cells. Our simulation results confirmed the double-adder mechanism. Chromosome replication initiation and cell division control are independent and regulated by respective proteins.Cell size homeostasis originates from division control and has nothing to do with replication initiation control. At a slow growth rate, the deviation from adder toward sizer comes from a significant division protein degradation rate when division protein is auto-inhibited. Our results indicated the two necessary conditions in the double-adder mechanism: one is balanced biosynthesis, and the other is that there is a protein trigger threshold to inspire DNA replication initiation and cell division. Our results give insight to the regulatory mechanism of cell size and instructive to synthetic biology.
文摘The study object is the angular output velocity of the drive shaft which is made up of two series-wound cross universal joints. We have deduced the function relation between the angular output velocity and initiative input angle of the drive shaft with double cross universal joints that is based on the calculation formula of the angular output velocity of a single cross universal joint, and by analyzing the relation between the two input angles. By using this function relation, the constant velocity condition of the drive shaft with double cross universal joints＂ is verified. The step-by-step searching algorithm is adopted to obtain the optimal phase angle that leads to the minimum fluctuate index of the angular output velocity in the vary velocity condition. At the same time, we worked out the maximal and minimum value of the angular output velocity, and their initiative input angle. The correctness of the function of the angular output velocity and the step-by-step search algorithm are verified by an ADAMS simulation example.
