In this paper we propose a two-layer emergent model for scalable swarm system. The first layer describes the indi-vidual flocking behavior to the local goal position (the center of minimal circumcircle decided by the ...In this paper we propose a two-layer emergent model for scalable swarm system. The first layer describes the indi-vidual flocking behavior to the local goal position (the center of minimal circumcircle decided by the neighbors in the positive visual set of individuals) resulting from the individual motion to one or two farthest neighbors in its positive visual set; the second layer describes the emergent aggregating swarm behavior resulting from the individual motion to its local goal position. The scale of the swarm will not be limited because only local individual information is used for modelling in the two-layer topology. We study the stability properties of the swarm emergent behavior based on Lyapunov stability theory. Simulations showed that the swarm system can converge to goal regions while maintaining cohesiveness.展开更多
Models disagree on a significant number of responses to climate change,such as climate feedback,regional changes,or the strength of equilibrium climate sensitivity.Emergent constraints aim to reduce these uncertaintie...Models disagree on a significant number of responses to climate change,such as climate feedback,regional changes,or the strength of equilibrium climate sensitivity.Emergent constraints aim to reduce these uncertainties by finding links between the inter-model spread in an observable predictor and climate projections.In this paper,the concepts underlying this framework are recalled with an emphasis on the statistical inference used for narrowing uncertainties,and a review of emergent constraints found in the last two decades.Potential links between highlighted predictors are explored,especially those targeting uncertainty reductions in climate sensitivity,cloud feedback,and changes of the hydrological cycle.Yet the disagreement across emergent constraints suggests that the spread in climate sensitivity can not be significantly narrowed.This calls for weighting the realism of emergent constraints by quantifying the level of physical understanding explaining the relationship.This would also permit more efficient model evaluation and better targeted model development.In the context of the upcoming CMIP6 model intercomparison a growing number of new predictors and uncertainty reductions is expected,which call for robust statistical inferences that allow cross-validation of more likely estimates.展开更多
The emergent task is a kind of uncertain event that satellite systems often encounter in the application process.In this paper,the multi-satellite distributed coordinating and scheduling problem considering emergent t...The emergent task is a kind of uncertain event that satellite systems often encounter in the application process.In this paper,the multi-satellite distributed coordinating and scheduling problem considering emergent tasks is studied.Due to the limitation of onboard computational resources and time,common online onboard rescheduling methods for such problems usually adopt simple greedy methods,sacrificing the solution quality to deliver timely solutions.To better solve the problem,a new multi-satellite onboard scheduling and coordinating framework based on multi-solution integration is proposed.This method uses high computational power on the ground and generates multiple solutions,changing the complex onboard rescheduling problem to a solution selection problem.With this method,it is possible that little time is used to generate a solution that is as good as the solutions on the ground.We further propose several multi-satellite coordination methods based on the multi-agent Markov decision process(MMDP)and mixed-integer programming(MIP).These methods enable the satellite to make independent decisions and produce high-quality solutions.Compared with the traditional centralized scheduling method,the proposed distributed method reduces the cost of satellite communication and increases the response speed for emergent tasks.Extensive experiments show that the proposed multi-solution integration framework and the distributed coordinating strategies are efficient and effective for onboard scheduling considering emergent tasks.展开更多
The emergent salt diapirs of the east Zagros, Iran have been investigated by their structural positions. The study area is including of Zagros orogeny belt and Persian Gulf that both of them have been formed on northe...The emergent salt diapirs of the east Zagros, Iran have been investigated by their structural positions. The study area is including of Zagros orogeny belt and Persian Gulf that both of them have been formed on northeastern part of Arabian plate. There are 84 emergent salt diapirs that originated from Hormuz formation with Infra-Cambrian to Cambrian age. Based on location, shape and orientation of the emergent salt domes in the east Zagros hinterland and Persian Gulf foreland basin, internal motivation forces in the salt deposits has been predominant compared to later tectonic forces. In the other words, most of the emergent salt diapirs are pre-orogenic diapirs and they had got prominent role as pines in determining the shape and location of next structures during to the Zagros orogeny. Finally, Neogene continental collision has a supplementary role to diapirism and salt reactivation. However there are an evidence to syn-orogenic emergent diapirs that they have got an important role in the progressive deformation.展开更多
Polarization singularities,which emerge from the incoherent superposition of two vector electric fields with the same frequency,and their evolution in free space are studied analytically and illustrated by numerical e...Polarization singularities,which emerge from the incoherent superposition of two vector electric fields with the same frequency,and their evolution in free space are studied analytically and illustrated by numerical examples.It is shown that there exist C-points,L-lines,in particular,C-lines in incoherently superimposed two-dimensional wavefields.Usually,the C-lines are unstable and disappear during the free-space propagation.The motion,pair creation-annihilation process of the emergent C-points,as well as the distortion of the L-lines may take place,and the degree of polarization of the emergent C-points varies upon propagation and may be less than 1.展开更多
Objective: Since its inception, the use of the percutaneous dilational tracheostomy (PDT) has been contraindicated in the setting of an emergent airway. Emerging in the literature are several cases of successful emerg...Objective: Since its inception, the use of the percutaneous dilational tracheostomy (PDT) has been contraindicated in the setting of an emergent airway. Emerging in the literature are several cases of successful emergent PDTs. Here we present our experience with the use of PDT in managing emergent airways. Study Design: All patients who underwent emergent PDT, using the Ciaglia Blue Rhino Introducer Set (Cook Critical Care, Bloomington,IN), in an academic county hospital setting between February 2010 and May 2012 were included in the study. Electronic medical records were reviewed for demographic and procedural data. Results: Twelve patients were included in the study with ages ranging from 20 to 87 (mean 57) years-old. The most common reason for emergent airway was trauma (7 patients), followed by obstructing neck mass (2 patients), septic shock (2 patients), and angioedema (1 patient). Seven PDTs were performed in the OR, four at bedside and one in the ER. Three of the 12 patients had emergent cricothyroidotomies in place that malfunctioned, requiring emergent conversion. No patients suffered from short term complications. One patient developed a neck abscess at the site of the PDT one month post operatively, two patients had accidental decanulation post operatively, and both were replaced without complication. Conclusions: PDT can be used in the emergent setting in the hands of trained practitioners with minimal complications. A larger, prospective trial is needed to make conclusions regarding patient care.展开更多
Recent experiments [Guo et al., Phys. Rev. Lett. 124 206602(2020)] on thermodynamic properties of the frustrated layered quantum magnet SrCu_(2)(BO_(3))_(2)-the Shastry–Sutherland material-have provided strong eviden...Recent experiments [Guo et al., Phys. Rev. Lett. 124 206602(2020)] on thermodynamic properties of the frustrated layered quantum magnet SrCu_(2)(BO_(3))_(2)-the Shastry–Sutherland material-have provided strong evidence for a lowtemperature phase transition between plaquette-singlet and antiferromagnetic order as a function of pressure. Further motivated by the recently discovered unusual first-order quantum phase transition with an apparent emergent O(4) symmetry of the antiferromagnetic and plaquette-singlet order parameters in a two-dimensional "checkerboard J-Q" quantum spin model[Zhao et al., Nat. Phys. 15 678(2019)], we here study the same model in the presence of weak inter-layer couplings. Our focus is on the evolution of the emergent symmetry as the system crosses over from two to three dimensions and the phase transition extends from strictly zero temperature in two dimensions up to finite temperature as expected in SrCu_(2)(BO_(3))_(2).Using quantum Monte Carlo simulations, we map out the phase boundaries of the plaquette-singlet and antiferromagnetic phases, with particular focus on the triple point where these two ordered phases meet the paramagnetic phase for given strength of the inter-layer coupling. All transitions are first-order in the neighborhood of the triple point. We show that the emergent O(4) symmetry of the coexistence state breaks down clearly when the interlayer coupling becomes sufficiently large, but for a weak coupling, of the magnitude expected experimentally, the enlarged symmetry can still be observed at the triple point up to significant length scales. Thus, it is likely that the plaquette-singlet to antiferromagnetic transition in SrCu_(2)(BO_(3))_(2) exhibits remnants of emergent O(4) symmetry, which should be observable due to additional weakly gapped Goldstone modes.展开更多
The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of f...The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of fidelity between the device and the patient.As regenerative medicine is still in its infancy,the ongoing search for new and effective prosthetic alternatives continues to be essential and highly rewarding.Thanks in part to the progress of imaging and the benefits of 3D printing,previously unimagined emergent technologies are at hand.The emerging technologies of the last few decades and the near future will continue to greatly improve both the quality and quantity of patients' lives.They focus on minimally invasive technologies(keyhole surgery) and approaches for deployment of valves,stent-grafts,leadless pacemakers and adaptation of medical devices for destination therapy(assist devices and artificial hearts).In addition,specific blood conduits for the aortic valves together with the aortic arch and the pulmonary valves are considered.These breakthroughs are currently at various stages of development and acceptability.Innovative biomaterials were essential in the development of cardiovascular devices.They were and they still are the essential support for conduction prosthesis,but their place in signal prosthesis is being revisited.Any new development in medical devices has been frequently driven by surgeons and industry.The emergent technologies are introduced by pioneers.The risks and benefits of devices must be continuously reassessed during the lifetime of the implants based upon sound scientific principles of investigation,clinical experience of the users and retrieval programs.展开更多
In this paper, the model of inverse cascade fractal super-blocks along one direction (in the positive or negative) in the 3-dimensional space is developed to describe the self-similar motion in macromolecular system. ...In this paper, the model of inverse cascade fractal super-blocks along one direction (in the positive or negative) in the 3-dimensional space is developed to describe the self-similar motion in macromolecular system. Microscopically the cohesive and dispersed states of the motion blocks are co-existent states with vastly different probability of occurrence.Experimental results and theoretical analysis show that the microscopic cohesive state energy and dispersed state energy of each motion block are respectively equal to the macroscopic glassy state energy kT8 and molten state energy kTm of the system. This singularity unveils topologically the nonintegrability, mathematically the anholonomy, and macroscopically the emergent property. This singularity also reveals that the glass, viscoelastic and melt states are three distinct emergent properties of macromolecular motion from a macroscopic viewpoint. The fractal concept of excluded volume is introduced to depict the random motion at various scales in the system. The Hausdorff dimensions of the excluded volune and the motion blocks are both found equal to 3/2.展开更多
By interpreting multifractal L-function zero alignment as a decoherence process, the Riemann hypothesis is demonstrated to imply the emergence of classical phase space at zero alignment. This provides a conception of ...By interpreting multifractal L-function zero alignment as a decoherence process, the Riemann hypothesis is demonstrated to imply the emergence of classical phase space at zero alignment. This provides a conception of emergent dynamics in which decoherence leads to classical system formation, and classical system trajectories are characterized by modular forms.展开更多
Entanglement and the tunnel effect phenomena have been repeatedly observed and are generically accepted under orthodox quantum mechanics formalism. However, they remain rather inexplicable in the context of spacetime ...Entanglement and the tunnel effect phenomena have been repeatedly observed and are generically accepted under orthodox quantum mechanics formalism. However, they remain rather inexplicable in the context of spacetime usual conceptualization. In the present work, we suggest an alternative quantum mechanics formalism, refining the pilot-wave theory initially proposed by de Broglie. We suggest that spacetime is an emergent phenomenon from a prior subquantum medium and that entanglement and the tunnel effect can be explained in terms of a nonlinear relation between space and time that is imposed by subquantum waves.展开更多
Based on the screening analysis for the first time in Montenegro, water samples for the presence of emergent wereanalyzed. Results from the locality Vukovci, the lower course of the river Morale, have shown the presen...Based on the screening analysis for the first time in Montenegro, water samples for the presence of emergent wereanalyzed. Results from the locality Vukovci, the lower course of the river Morale, have shown the presence of chemical components that indicate the presence of emergent in the water. Thus identification component is associated with the presence of fiziological groups of microorganisms at the site, which with its functional and significant role in many ways reduce environmental stress.展开更多
At present, the Portuguese education system promotes the development of new literacies in all education levels in response to new requirements of the digital world which imply changes in children＇s education. In fact...At present, the Portuguese education system promotes the development of new literacies in all education levels in response to new requirements of the digital world which imply changes in children＇s education. In fact, reading and writing are no longer limited exclusively to books, rather they are associated with diversified digital media integrating text, sound, image, and video. In this context, we developed an exploratory study in a kindergarten with the children and their family members. Data were collected through participant observation, children conversational interviews, and digital narratives produced by children. Data analysis is based on content analysis with NVivo software support. The emergence of literacy is evident in verbal interactions in peer-group work, in contact with the written text, in ＂writing＂ in various media, and in sharing knowledge, discoveries, and digital narratives produced in an online community （http：//janelajardim.ning.com）. This paper presents： （1） a systematic literature review in the field of digital narrative and emergent literacy; （2） the description of children＇s activities concerning interactive multimodal narrative; （3） the results of this work; and （4） the conclusion about contribution of multimodal narratives to the emergence of reading, writing, and digital skills展开更多
The study investigated the university students＇ attitudes towards the coexistence of the standard discourse and the emergent discourses through a questionnaire. 223 sophomores in Xinjiang Normal University participat...The study investigated the university students＇ attitudes towards the coexistence of the standard discourse and the emergent discourses through a questionnaire. 223 sophomores in Xinjiang Normal University participated in the survey. The results show that these students tend to accept the emergent discourses in terms of their new vocabulary words, such as ＂yumi＂. Although the standard discourse dominates the students＇ life, the emergent discourses are accepted and used by these students. With regard to the view to purify the Chinese language, human concern and tolerance for the coexistence of various discourses are suggested.展开更多
The nonlinear affine Goldstone model of the emergent gravity, built on the nonlinearly realized/ hidden affine symmetry, is concisely revisited. Beyond General Relativity, the explicit violation of general invariance/...The nonlinear affine Goldstone model of the emergent gravity, built on the nonlinearly realized/ hidden affine symmetry, is concisely revisited. Beyond General Relativity, the explicit violation of general invariance/relativity, under preserving general covariance, is exposed. Dependent on a nondynamical affine connection, a generally covariant second-order effective Lagrangian for metric gravity is worked out, with the general relativity violation and the gravitational dark matter serving as the signatures of emergence.展开更多
At present, there are some resistible illegal operations aiming at creating false public opinions in internet public opinions on emergent event, which seriously disrupted the normal Internet order. However, the tradit...At present, there are some resistible illegal operations aiming at creating false public opinions in internet public opinions on emergent event, which seriously disrupted the normal Internet order. However, the traditional research method of internet public opinion pre-waming mainly relies on manual analysis, which is too inefficient to adapt to the analysis of massive internet public opinion information. According to the above analysis, this paper puts forward an internet public opinion pre-warning mechanism on emergent event based on multi-relational data clustering algorithm, discusses the specific pre-waming from the aspects of the state and dissemination of internet public opinions and the historical data, and automatically classifies the internet public opinions through multi-relational data clustering algorithm. And the results show that such method can be used to effectively study the internet public opinion pre-waming on emergent event, with the accuracy rate of as high as 95%.展开更多
The extent of emergent vegetation can be a useful indicator of lake health and identify trends and changes over time. However, field data to characterize emergent vegetation may not be available (especially over longe...The extent of emergent vegetation can be a useful indicator of lake health and identify trends and changes over time. However, field data to characterize emergent vegetation may not be available (especially over longer time periods) or may be limited to small, isolated areas. We present a case study using Lands at data to generate indicators that represent emergent vegetation extent in the near-shoreline and tributary delta areas of Malheur Lake, Oregon, USA. Malheur Lake has a large non-native carp population that may significantly affect emergent vegetation and adversely impact reservoir health. This study evaluates long-term trends in emergent vegetation and correlation with common environmental variables other than carp, to determine if emergent vegetation changes can be explained. We selected late June images for this study as vegetation is relatively mature in late June and visible, but has not completely grown-in providing a better indication of vegetation coverage in satellite images. To explore trends in historic emergent vegetation extent, we identified eight regions-of-interest (ROI): three inlet areas, three wet-shore areas (swampy areas), and two dry-shore areas (less swampy areas) around Malheur Lake and computed the Normalized Difference Vegetation Index (NDVI) using 30 years of Lands at images from 1984 to 2013. For each ROI we generated time-series data to quantify the emergent vegetation as determined by the percent of area covered by pixels that had NDVI values greater than 0.2, using cutoff as an indicator of vegetation. For correlation, we produced a corresponding time series of the lake area using the Modified Normalized Difference Water Index (MNDWI) to identify water pixels. We investigated the correlation of vegetation coverage (an indicator of emergent vegetation) with lake area, June precipitation, and average daily maximum temperatures for a period from two months prior to one month after the June collection (April, May, June, and July);all parameters that could affect vegetation growth. We found minimal correlation over time of the vegetative extent in any of the eight ROIs with the selected parameters, indicating that there are other factors which drive emergent vegetation extent in Malheur Lake. This study demonstrates that Landsat data have sufficient spatial and temporal detail to provide insight into ecosystem changes over relatively long periods and offers a method to study historic trends in reservoir health and evaluate potential influences. We expect future work will explore other potential drivers of emergent vegetation extent in Malheur Lake, such as carp populations. Carp were not considered in this study as we did not have access to data that reflect carp numbers over this 30 year period.展开更多
This paper, in conjunction with recent Flat Space Cosmology (FSC) publications, provides theoretical support for cosmic time being an emergent property of cosmic entropy and temperature. Therefore, if Verlinde’s “em...This paper, in conjunction with recent Flat Space Cosmology (FSC) publications, provides theoretical support for cosmic time being an emergent property of cosmic entropy and temperature. Therefore, if Verlinde’s “emergent gravity” theory is correct, both time and gravity are most fundamentally emergent properties of cosmic thermodynamics. Since emergent properties within complex systems with a huge number of degrees of freedom are often not definable at the smallest scales, these results suggest that quantum time and quantum gravity may be no more definable than consciousness within two connecting neurons. String theorists now struggling to define quantum space-time and quantum gravity should bear this in mind.展开更多
Laparoscopic surgery has become well established in the management of both and malignant colorectal disease.The last decade has seen increasing numbers of surgeons trained to a high standard in minimallyinvasive surge...Laparoscopic surgery has become well established in the management of both and malignant colorectal disease.The last decade has seen increasing numbers of surgeons trained to a high standard in minimallyinvasive surgery.However there has not been the same enthusiasm for the use of laparoscopy in emergency colorectal surgery.There is a perception that emergent surgery is technically more difficult and may lead to worse outcomes.The present review aims to provide a comprehensive and critical appraisal of the available literature on the use of laparoscopic colorectal surgery(LCS)in the emergency setting.The literature is broadly divided by the underlying pathology;that is,inflammatory bowel disease,diverticulitis and malignant obstruction.There were no randomized trials and the majority of the studies were case-matched series or comparative studies.The overall trend was that LCS is associated with shorter hospital stay,par or fewer complications but an increased operating time.Emergency LCS can be safely undertaken for both benign and malignant disease providing there is appropriate patient selection,the surgeon is adequately experienced and there are sufficient resources to allow for a potentially more complex operation.展开更多
基金Project (No. 60574088) supported by the National Natural ScienceFoundation of China
文摘In this paper we propose a two-layer emergent model for scalable swarm system. The first layer describes the indi-vidual flocking behavior to the local goal position (the center of minimal circumcircle decided by the neighbors in the positive visual set of individuals) resulting from the individual motion to one or two farthest neighbors in its positive visual set; the second layer describes the emergent aggregating swarm behavior resulting from the individual motion to its local goal position. The scale of the swarm will not be limited because only local individual information is used for modelling in the two-layer topology. We study the stability properties of the swarm emergent behavior based on Lyapunov stability theory. Simulations showed that the swarm system can converge to goal regions while maintaining cohesiveness.
基金funding from the Agence Nationale de la Recherche (ANR) [grant HIGH-TUNE ANR-16-CE01-0010]
文摘Models disagree on a significant number of responses to climate change,such as climate feedback,regional changes,or the strength of equilibrium climate sensitivity.Emergent constraints aim to reduce these uncertainties by finding links between the inter-model spread in an observable predictor and climate projections.In this paper,the concepts underlying this framework are recalled with an emphasis on the statistical inference used for narrowing uncertainties,and a review of emergent constraints found in the last two decades.Potential links between highlighted predictors are explored,especially those targeting uncertainty reductions in climate sensitivity,cloud feedback,and changes of the hydrological cycle.Yet the disagreement across emergent constraints suggests that the spread in climate sensitivity can not be significantly narrowed.This calls for weighting the realism of emergent constraints by quantifying the level of physical understanding explaining the relationship.This would also permit more efficient model evaluation and better targeted model development.In the context of the upcoming CMIP6 model intercomparison a growing number of new predictors and uncertainty reductions is expected,which call for robust statistical inferences that allow cross-validation of more likely estimates.
基金supported by the National Natural Science Foundation of China(72001212,71701204,71801218)the China Hunan Postgraduate Research Innovating Project(CX2018B020)。
文摘The emergent task is a kind of uncertain event that satellite systems often encounter in the application process.In this paper,the multi-satellite distributed coordinating and scheduling problem considering emergent tasks is studied.Due to the limitation of onboard computational resources and time,common online onboard rescheduling methods for such problems usually adopt simple greedy methods,sacrificing the solution quality to deliver timely solutions.To better solve the problem,a new multi-satellite onboard scheduling and coordinating framework based on multi-solution integration is proposed.This method uses high computational power on the ground and generates multiple solutions,changing the complex onboard rescheduling problem to a solution selection problem.With this method,it is possible that little time is used to generate a solution that is as good as the solutions on the ground.We further propose several multi-satellite coordination methods based on the multi-agent Markov decision process(MMDP)and mixed-integer programming(MIP).These methods enable the satellite to make independent decisions and produce high-quality solutions.Compared with the traditional centralized scheduling method,the proposed distributed method reduces the cost of satellite communication and increases the response speed for emergent tasks.Extensive experiments show that the proposed multi-solution integration framework and the distributed coordinating strategies are efficient and effective for onboard scheduling considering emergent tasks.
文摘The emergent salt diapirs of the east Zagros, Iran have been investigated by their structural positions. The study area is including of Zagros orogeny belt and Persian Gulf that both of them have been formed on northeastern part of Arabian plate. There are 84 emergent salt diapirs that originated from Hormuz formation with Infra-Cambrian to Cambrian age. Based on location, shape and orientation of the emergent salt domes in the east Zagros hinterland and Persian Gulf foreland basin, internal motivation forces in the salt deposits has been predominant compared to later tectonic forces. In the other words, most of the emergent salt diapirs are pre-orogenic diapirs and they had got prominent role as pines in determining the shape and location of next structures during to the Zagros orogeny. Finally, Neogene continental collision has a supplementary role to diapirism and salt reactivation. However there are an evidence to syn-orogenic emergent diapirs that they have got an important role in the progressive deformation.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874125)
文摘Polarization singularities,which emerge from the incoherent superposition of two vector electric fields with the same frequency,and their evolution in free space are studied analytically and illustrated by numerical examples.It is shown that there exist C-points,L-lines,in particular,C-lines in incoherently superimposed two-dimensional wavefields.Usually,the C-lines are unstable and disappear during the free-space propagation.The motion,pair creation-annihilation process of the emergent C-points,as well as the distortion of the L-lines may take place,and the degree of polarization of the emergent C-points varies upon propagation and may be less than 1.
文摘Objective: Since its inception, the use of the percutaneous dilational tracheostomy (PDT) has been contraindicated in the setting of an emergent airway. Emerging in the literature are several cases of successful emergent PDTs. Here we present our experience with the use of PDT in managing emergent airways. Study Design: All patients who underwent emergent PDT, using the Ciaglia Blue Rhino Introducer Set (Cook Critical Care, Bloomington,IN), in an academic county hospital setting between February 2010 and May 2012 were included in the study. Electronic medical records were reviewed for demographic and procedural data. Results: Twelve patients were included in the study with ages ranging from 20 to 87 (mean 57) years-old. The most common reason for emergent airway was trauma (7 patients), followed by obstructing neck mass (2 patients), septic shock (2 patients), and angioedema (1 patient). Seven PDTs were performed in the OR, four at bedside and one in the ER. Three of the 12 patients had emergent cricothyroidotomies in place that malfunctioned, requiring emergent conversion. No patients suffered from short term complications. One patient developed a neck abscess at the site of the PDT one month post operatively, two patients had accidental decanulation post operatively, and both were replaced without complication. Conclusions: PDT can be used in the emergent setting in the hands of trained practitioners with minimal complications. A larger, prospective trial is needed to make conclusions regarding patient care.
基金the support from the RGC of Hong Kong SAR China (Grant Nos. GRF 17303019 and 17301420)the National Key Research and Development Program of China (Grant No. 2016YFA0300502)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No. XDB33000000)support from the National Natural Science Foundation of China (Grant No. 12004020)AWS was supported by the NSF (Grant No. DMR-1710170)by the Simons Foundation (Grant No. 511064)。
文摘Recent experiments [Guo et al., Phys. Rev. Lett. 124 206602(2020)] on thermodynamic properties of the frustrated layered quantum magnet SrCu_(2)(BO_(3))_(2)-the Shastry–Sutherland material-have provided strong evidence for a lowtemperature phase transition between plaquette-singlet and antiferromagnetic order as a function of pressure. Further motivated by the recently discovered unusual first-order quantum phase transition with an apparent emergent O(4) symmetry of the antiferromagnetic and plaquette-singlet order parameters in a two-dimensional "checkerboard J-Q" quantum spin model[Zhao et al., Nat. Phys. 15 678(2019)], we here study the same model in the presence of weak inter-layer couplings. Our focus is on the evolution of the emergent symmetry as the system crosses over from two to three dimensions and the phase transition extends from strictly zero temperature in two dimensions up to finite temperature as expected in SrCu_(2)(BO_(3))_(2).Using quantum Monte Carlo simulations, we map out the phase boundaries of the plaquette-singlet and antiferromagnetic phases, with particular focus on the triple point where these two ordered phases meet the paramagnetic phase for given strength of the inter-layer coupling. All transitions are first-order in the neighborhood of the triple point. We show that the emergent O(4) symmetry of the coexistence state breaks down clearly when the interlayer coupling becomes sufficiently large, but for a weak coupling, of the magnitude expected experimentally, the enlarged symmetry can still be observed at the triple point up to significant length scales. Thus, it is likely that the plaquette-singlet to antiferromagnetic transition in SrCu_(2)(BO_(3))_(2) exhibits remnants of emergent O(4) symmetry, which should be observable due to additional weakly gapped Goldstone modes.
基金"111 Project" Biomedical Textile Material Science and Technology,China(No.B07024)National Natural Science Foundations of China(Nos.31100682,81371648)+2 种基金the Shanghai Construction of College Experiment Technique Team Project,China(No.101-07.0053014)the Fundamental Research Funds for the Central University,China(No.15D110126)the Department of Surgery at Laval University,Quebec and the Fonds de Recherche en Chirurgie Vasculaire of the CHU,Quebec,Canada
文摘The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of fidelity between the device and the patient.As regenerative medicine is still in its infancy,the ongoing search for new and effective prosthetic alternatives continues to be essential and highly rewarding.Thanks in part to the progress of imaging and the benefits of 3D printing,previously unimagined emergent technologies are at hand.The emerging technologies of the last few decades and the near future will continue to greatly improve both the quality and quantity of patients' lives.They focus on minimally invasive technologies(keyhole surgery) and approaches for deployment of valves,stent-grafts,leadless pacemakers and adaptation of medical devices for destination therapy(assist devices and artificial hearts).In addition,specific blood conduits for the aortic valves together with the aortic arch and the pulmonary valves are considered.These breakthroughs are currently at various stages of development and acceptability.Innovative biomaterials were essential in the development of cardiovascular devices.They were and they still are the essential support for conduction prosthesis,but their place in signal prosthesis is being revisited.Any new development in medical devices has been frequently driven by surgeons and industry.The emergent technologies are introduced by pioneers.The risks and benefits of devices must be continuously reassessed during the lifetime of the implants based upon sound scientific principles of investigation,clinical experience of the users and retrieval programs.
文摘In this paper, the model of inverse cascade fractal super-blocks along one direction (in the positive or negative) in the 3-dimensional space is developed to describe the self-similar motion in macromolecular system. Microscopically the cohesive and dispersed states of the motion blocks are co-existent states with vastly different probability of occurrence.Experimental results and theoretical analysis show that the microscopic cohesive state energy and dispersed state energy of each motion block are respectively equal to the macroscopic glassy state energy kT8 and molten state energy kTm of the system. This singularity unveils topologically the nonintegrability, mathematically the anholonomy, and macroscopically the emergent property. This singularity also reveals that the glass, viscoelastic and melt states are three distinct emergent properties of macromolecular motion from a macroscopic viewpoint. The fractal concept of excluded volume is introduced to depict the random motion at various scales in the system. The Hausdorff dimensions of the excluded volune and the motion blocks are both found equal to 3/2.
文摘By interpreting multifractal L-function zero alignment as a decoherence process, the Riemann hypothesis is demonstrated to imply the emergence of classical phase space at zero alignment. This provides a conception of emergent dynamics in which decoherence leads to classical system formation, and classical system trajectories are characterized by modular forms.
文摘Entanglement and the tunnel effect phenomena have been repeatedly observed and are generically accepted under orthodox quantum mechanics formalism. However, they remain rather inexplicable in the context of spacetime usual conceptualization. In the present work, we suggest an alternative quantum mechanics formalism, refining the pilot-wave theory initially proposed by de Broglie. We suggest that spacetime is an emergent phenomenon from a prior subquantum medium and that entanglement and the tunnel effect can be explained in terms of a nonlinear relation between space and time that is imposed by subquantum waves.
文摘Based on the screening analysis for the first time in Montenegro, water samples for the presence of emergent wereanalyzed. Results from the locality Vukovci, the lower course of the river Morale, have shown the presence of chemical components that indicate the presence of emergent in the water. Thus identification component is associated with the presence of fiziological groups of microorganisms at the site, which with its functional and significant role in many ways reduce environmental stress.
文摘At present, the Portuguese education system promotes the development of new literacies in all education levels in response to new requirements of the digital world which imply changes in children＇s education. In fact, reading and writing are no longer limited exclusively to books, rather they are associated with diversified digital media integrating text, sound, image, and video. In this context, we developed an exploratory study in a kindergarten with the children and their family members. Data were collected through participant observation, children conversational interviews, and digital narratives produced by children. Data analysis is based on content analysis with NVivo software support. The emergence of literacy is evident in verbal interactions in peer-group work, in contact with the written text, in ＂writing＂ in various media, and in sharing knowledge, discoveries, and digital narratives produced in an online community （http：//janelajardim.ning.com）. This paper presents： （1） a systematic literature review in the field of digital narrative and emergent literacy; （2） the description of children＇s activities concerning interactive multimodal narrative; （3） the results of this work; and （4） the conclusion about contribution of multimodal narratives to the emergence of reading, writing, and digital skills
文摘The study investigated the university students＇ attitudes towards the coexistence of the standard discourse and the emergent discourses through a questionnaire. 223 sophomores in Xinjiang Normal University participated in the survey. The results show that these students tend to accept the emergent discourses in terms of their new vocabulary words, such as ＂yumi＂. Although the standard discourse dominates the students＇ life, the emergent discourses are accepted and used by these students. With regard to the view to purify the Chinese language, human concern and tolerance for the coexistence of various discourses are suggested.
文摘The nonlinear affine Goldstone model of the emergent gravity, built on the nonlinearly realized/ hidden affine symmetry, is concisely revisited. Beyond General Relativity, the explicit violation of general invariance/relativity, under preserving general covariance, is exposed. Dependent on a nondynamical affine connection, a generally covariant second-order effective Lagrangian for metric gravity is worked out, with the general relativity violation and the gravitational dark matter serving as the signatures of emergence.
文摘At present, there are some resistible illegal operations aiming at creating false public opinions in internet public opinions on emergent event, which seriously disrupted the normal Internet order. However, the traditional research method of internet public opinion pre-waming mainly relies on manual analysis, which is too inefficient to adapt to the analysis of massive internet public opinion information. According to the above analysis, this paper puts forward an internet public opinion pre-warning mechanism on emergent event based on multi-relational data clustering algorithm, discusses the specific pre-waming from the aspects of the state and dissemination of internet public opinions and the historical data, and automatically classifies the internet public opinions through multi-relational data clustering algorithm. And the results show that such method can be used to effectively study the internet public opinion pre-waming on emergent event, with the accuracy rate of as high as 95%.
文摘The extent of emergent vegetation can be a useful indicator of lake health and identify trends and changes over time. However, field data to characterize emergent vegetation may not be available (especially over longer time periods) or may be limited to small, isolated areas. We present a case study using Lands at data to generate indicators that represent emergent vegetation extent in the near-shoreline and tributary delta areas of Malheur Lake, Oregon, USA. Malheur Lake has a large non-native carp population that may significantly affect emergent vegetation and adversely impact reservoir health. This study evaluates long-term trends in emergent vegetation and correlation with common environmental variables other than carp, to determine if emergent vegetation changes can be explained. We selected late June images for this study as vegetation is relatively mature in late June and visible, but has not completely grown-in providing a better indication of vegetation coverage in satellite images. To explore trends in historic emergent vegetation extent, we identified eight regions-of-interest (ROI): three inlet areas, three wet-shore areas (swampy areas), and two dry-shore areas (less swampy areas) around Malheur Lake and computed the Normalized Difference Vegetation Index (NDVI) using 30 years of Lands at images from 1984 to 2013. For each ROI we generated time-series data to quantify the emergent vegetation as determined by the percent of area covered by pixels that had NDVI values greater than 0.2, using cutoff as an indicator of vegetation. For correlation, we produced a corresponding time series of the lake area using the Modified Normalized Difference Water Index (MNDWI) to identify water pixels. We investigated the correlation of vegetation coverage (an indicator of emergent vegetation) with lake area, June precipitation, and average daily maximum temperatures for a period from two months prior to one month after the June collection (April, May, June, and July);all parameters that could affect vegetation growth. We found minimal correlation over time of the vegetative extent in any of the eight ROIs with the selected parameters, indicating that there are other factors which drive emergent vegetation extent in Malheur Lake. This study demonstrates that Landsat data have sufficient spatial and temporal detail to provide insight into ecosystem changes over relatively long periods and offers a method to study historic trends in reservoir health and evaluate potential influences. We expect future work will explore other potential drivers of emergent vegetation extent in Malheur Lake, such as carp populations. Carp were not considered in this study as we did not have access to data that reflect carp numbers over this 30 year period.
文摘This paper, in conjunction with recent Flat Space Cosmology (FSC) publications, provides theoretical support for cosmic time being an emergent property of cosmic entropy and temperature. Therefore, if Verlinde’s “emergent gravity” theory is correct, both time and gravity are most fundamentally emergent properties of cosmic thermodynamics. Since emergent properties within complex systems with a huge number of degrees of freedom are often not definable at the smallest scales, these results suggest that quantum time and quantum gravity may be no more definable than consciousness within two connecting neurons. String theorists now struggling to define quantum space-time and quantum gravity should bear this in mind.
文摘Laparoscopic surgery has become well established in the management of both and malignant colorectal disease.The last decade has seen increasing numbers of surgeons trained to a high standard in minimallyinvasive surgery.However there has not been the same enthusiasm for the use of laparoscopy in emergency colorectal surgery.There is a perception that emergent surgery is technically more difficult and may lead to worse outcomes.The present review aims to provide a comprehensive and critical appraisal of the available literature on the use of laparoscopic colorectal surgery(LCS)in the emergency setting.The literature is broadly divided by the underlying pathology;that is,inflammatory bowel disease,diverticulitis and malignant obstruction.There were no randomized trials and the majority of the studies were case-matched series or comparative studies.The overall trend was that LCS is associated with shorter hospital stay,par or fewer complications but an increased operating time.Emergency LCS can be safely undertaken for both benign and malignant disease providing there is appropriate patient selection,the surgeon is adequately experienced and there are sufficient resources to allow for a potentially more complex operation.
