Aiming at mitigating the high risks associated with conventional explosive blasting,this study developed a safe directional fracturing technique,i.e.instantaneous expansion with a single fracture(IESF),using a coal-ba...Aiming at mitigating the high risks associated with conventional explosive blasting,this study developed a safe directional fracturing technique,i.e.instantaneous expansion with a single fracture(IESF),using a coal-based solid waste expanding agent.First,the mechanism of directional fracturing blasting by the IESF was analyzed,and the criterion of directional crack initiation was established.On this basis,laboratory experiments and numerical simulations were conducted to systematically evaluate the directional fracturing blasting performance of the IESF.The results indicate that the IESF presents an excellent directional fracturing effect,with average surface undulation differences ranging from 8.1 mm to 22.7 mm on the fracture surfaces.Moreover,during concrete fracturing tests,the stresses and strains in the fracturing direction are measured to be 2.16-3.71 times and 8 times larger than those in the nonfracturing direction,respectively.Finally,the IESF technique was implemented for no-pillar mining with gob-side entry retaining through roof cutting and pressure relief in an underground coal mine.The IESF technique effectively created directional cracks in the roof without causing severe roadway deformation,achieving an average cutting rate and maximum roadway deformation of 94%and 197 mm,respectively.These on-site test results verified its excellent directional rock fracturing performance.The IESF technique,which is safe,efficient,and green,has considerable application prospects in the field of rock mechanics and engineering.展开更多
Astronomical extreme events or phenomena include black holes as well as nebulae systems that resemble the Milky Way. Meteorological extreme events or phenomena include tornadoes and tropical cyclones. The new high ene...Astronomical extreme events or phenomena include black holes as well as nebulae systems that resemble the Milky Way. Meteorological extreme events or phenomena include tornadoes and tropical cyclones. The new high energy state of matter expanding outwards by spin jets from the two poles of an astronomical black hole, the new high energy state of matter in a funnel-shaped vortex showed a meteorological tornado expanding downwards from a rotated disk of cumulonimbus clouds, the new high energy state of matter in a tropical cyclone and the new high energy state of a nebulae system converging celestial materials are phenomena across disciplines and multiple time-space scales that have not yet been physically explained. In this paper, the theory of orthogonal collision in the rotational contraction continuum is used to unify the understanding of diverse extreme events or phenomena through a single dynamical mechanism, offering insights into natural processes across disciplines. In the field of astronomy, the orthogonal collision of two-beam rotating and contracting particles or stars associated with centripetal forces forms a new high-energy state of matter at the collision point and the new high-energy particles have expanding forces outward to both sides of the collision plane. In the field of meteorology, the orthogonal collision of multiple horizontally rotating and contracting airflows associated with centripetal forces forms a new high energy state of matter at the collision point as well as an updraft force and a downdraft force vertically. The updraft force and downdraft force formed by the collision of anomalous wet airflows in the lower atmosphere can well indicate tornado, thunderstorm and extreme precipitation. The orthogonal collision theory can be applied to explain new states of matter in disciplines from the astronomical scale to the meteorological scale and the Planck scale.展开更多
Confronting the escalating global challenge of counterfeit products,developing advanced anticounterfeiting materials and structures with physical unclonable functions(PUFs)has become imperative.All-optical PUFs,distin...Confronting the escalating global challenge of counterfeit products,developing advanced anticounterfeiting materials and structures with physical unclonable functions(PUFs)has become imperative.All-optical PUFs,distinguished by their high output complexity and expansive response space,offer a promising alternative to conventional electronic counterparts.For practical authentications,the expansion of optical PUF keys usually involves intricate spatial or spectral shaping of excitation light using bulky external apparatus,which largely hinders the applications of optical PUFs.Here,we report a plasmonic PUF system based on heterogeneous nanostructures.The template-assisted shadow deposition technique was employed to adjust the morphological diversity of densely packed metal nanoparticles in individual PUFs.Transmission images were processed via a hash algorithm,and the generated PUF keys with a scalable capacity from 2875 to 243401 exhibit excellent uniqueness,randomness,and reproducibility.Furthermore,the wavelength and the polarization state of the excitation light are harnessed as two distinct expanding strategies,offering the potential for multiscenario applications via a single PUF.Overall,our reported plasmonic PUFs operated with the multidimensional expanding strategy are envisaged to serve as easy-to-integrate,easy-to-use systems and promise efficacy across a broad spectrum of applications,from anticounterfeiting to data encryption and authentication.展开更多
Purpose:This study aims to foster a dialog between the experiences and identities of Nigerian female breast cancer survivors and Margaret Newman’s theory of health as expanding consciousness.The theory was employed t...Purpose:This study aims to foster a dialog between the experiences and identities of Nigerian female breast cancer survivors and Margaret Newman’s theory of health as expanding consciousness.The theory was employed to explore and describe the structure and meaning of these survivors’experiences and identities.Methods:Twenty-two participants were interviewed using a qualitative approach.The interviews were digitally recorded and transcribed verbatim.Data analysis was conducted using NVivo 14 software to identify recurring patterns within the data.Results:Three core themes emerged:(1)Encountering Selfhood-Otherhood in the survivorship journey,(2)navigating the rhythms of change,and(3)living the paradox of order and disorder.These themes reflect the unique and paradoxical rhythm of life as a breast cancer survivor,integrating these experiences conceptually.Conclusions:This study illuminates how Nigerian breast cancer survivors construct the patterns of meaning of their experiences by shifting the focus from solely evidence-based interventions to a deeper exploration of lived experience,cultural narratives,and expanding consciousness.Through compassionate and insightful nursing interactions,women can explore their evolving identities,foster resilience,and redefine their lives in meaningful and fulfilling ways within their unique contexts.Implications for Cancer Survivors:Greater attention is required to address the emotional,temporal,and economic dimensions of breast cancer survivorship in Nigeria.Nurses play a crucial role in helping survivors find meaning in their experiences,recognizing that order and disorder in life are integral to expanding consciousness.Survivors should be empowered to identify their patterns of living and leverage their strengths in navigating the survivorship journey and finding meaning in their lives.展开更多
Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of th...Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality.展开更多
Additive manufacturing(AM),commonly known as 3D printing,has become a transformative technology that has a profound impact on various industrial sectors.AM encompasses a set of techniques for building objects layer by...Additive manufacturing(AM),commonly known as 3D printing,has become a transformative technology that has a profound impact on various industrial sectors.AM encompasses a set of techniques for building objects layer by layer from digital models.Unlike conventional subtractive manufacturing methods that involve removing material from large blocks,AM adds material incrementally,providing unprecedented design flexibility and efficiency.展开更多
The CICG President Du Zhanyuan shares his insights about China-Europe talent cooperation.THE history of exchange between China and Europe is long and profound.Since the 16th century,European thinkers represented by Vo...The CICG President Du Zhanyuan shares his insights about China-Europe talent cooperation.THE history of exchange between China and Europe is long and profound.Since the 16th century,European thinkers represented by Voltaire,Bertrand Russell,and Arnold Joseph Toynbee have taken Chinese philosophy as a valuable complement to the European ideological system.China has also absorbed the ideas of European giants such as Adam Smith,Georg Wilhelm Friedrich Hegel,and Karl Marx for its transformation and progress.In recent years,exchanges and interactions between the two sides in various fields have become increasingly close.展开更多
This work identifies the branch point, which was never explicit in EM treatises, from which came the choice of abandoning the Galilean transformations in favor of the Lorentz covariance, a path that originated the var...This work identifies the branch point, which was never explicit in EM treatises, from which came the choice of abandoning the Galilean transformations in favor of the Lorentz covariance, a path that originated the various relativistic theories. The need arising from the expanding Earth for a hydrodynamic mechanism for Newtonian and Coulomb fields is discussed. This hydrodynamic material mechanism is shown to constitute a completion of the Newton and Maxwell concepts of the fields, which were only a phenomenological description of physical reality. It is shown that the analogy between Maxwell’s equations and hydrodynamics cannot become a perfect correspondence. The lack of coupling of the electromagnetic field to the underlying material “causing field”—which induces hydrodynamical forces and accelerations observed only phenomenologically—gives rise to inaccuracies in the formulation of its equations, which are incorrect for Galilean covariance. But the most serious flaw in the original formulation of electromagnetism is the erroneous identification of the flow velocity of the field (variable as 1/r2) with the speed of light c, with which it was demonstrated that the fields of charges in motion contract in the direction of motion (the Heaviside ellipsoid, 1888, 1889). From this error, historically due to the incomplete development of many hydrodynamics sectors (a situation that persists today), came Fitz Gerald’s contractions and finally, the relativistic theories. Some future research lines are proposed for a return to realistic physics and a possible but still weak form of Galilean covariance.展开更多
The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack int...The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack into unbranched fibrils.Stranger still,a single protein sequence can adopt wildly different two-dimensional conformations,yielding distinct fibril polymorphs.展开更多
BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on s...BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures.展开更多
Based on the parametric analysis of the expanding zone of the vacuum dust suction mouth,the flow in the vacuum dust suction mouth was simulated by computational fluid dynamics(CFD)software,Fluent.The effects of the ex...Based on the parametric analysis of the expanding zone of the vacuum dust suction mouth,the flow in the vacuum dust suction mouth was simulated by computational fluid dynamics(CFD)software,Fluent.The effects of the expanding zone parameters on flow simulation were analyzed.The results show that simulation effects depend on threshold values of the expanding zone parameters of the dust suction mouth,and the threshold values of the expanding zone can be obtained according to the different structures of the vacuum dust suction mouth and be selected as the geometric parameters in calculating,and also corners of the expanding zone make unobvious difference in calculation accuracy and in computational efficiency compared with no corner.The simulation results provide practical guidance to the flow simulation on the dust suction mouth.展开更多
For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testin...For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testing produces the uniform stress and strain rates but the testing is expensive. The Taylor test is relatively inexpensive but produces non-uniform stress and strain fields, and the results are not so easily inferred for material modeling. In the split-Hopkinson bar(SHB), which may be used in compression, tension and torsion testing, the strain rates never exceeds 103/s. In the present work, we use the expanding ring test where the strain rate is 104e105/s. A streak camera is used to examine the expanding ring velocity, and a water tank is used to collect the fragments. The experimental results are compared with the numerical simulations using the hydrocodes AUTODYN, IMPETUS Afea and a regularized smooth particle(RSPH) software. The number of fragments increases with the increase in the expansion velocity of the rings. The number of fragments is similar to the experimental results. The RSPH software shows much the same results as the AUTODYN where the Lagrangian solver is used for the ring. The IMPETUS Afea solver shows a somewhat different fragmentation characteristic due to the node splitting algorithm that induces pronounced tensile splitting.展开更多
The two major challenges in industrial enzymatic catalysis are the limited number of chemical reaction types that are catalyzed by enzymes and the instability of enzymes under harsh conditions in industrial catalysis....The two major challenges in industrial enzymatic catalysis are the limited number of chemical reaction types that are catalyzed by enzymes and the instability of enzymes under harsh conditions in industrial catalysis.Expanding enzyme catalysis to a larger substrate scope and greater variety of chemical reactions and tuning the microenvironment surrounding enzyme molecules to achieve high enzyme performance are urgently needed.In this account,we focus on our efforts using the de novo approach to synthesis hybrid enzyme catalysts that can address these two challenges and the structure-function relationship is discussed to reveal the principles of designing hybrid enzyme catalysts.We hope that this account will promote further efforts toward fundamental research and wide applications of designed enzyme hybrid catalysts for expanding biocatalysis.展开更多
A new severe plastic deformation method for manufacturing tubes made of AZ31 magnesium alloy with a large diameter was developed,which is called the TCESE(tube continuous extrusion−shear−expanding)process.The process ...A new severe plastic deformation method for manufacturing tubes made of AZ31 magnesium alloy with a large diameter was developed,which is called the TCESE(tube continuous extrusion−shear−expanding)process.The process combines direct extrusion with a two-step shear−expanding process.The influences of expanding ratios,extrusion temperatures on the deformation of finite element meshes,strain evolution and flow velocity of tube blanks during the TCESE process were researched based on numerical simulations by using DEFORM-3D software.Simulation results show that the maximum expanding ratio is 3.0 in the TCESE process.The deformation of finite element meshes of tube blanks is inhomogeneous in the shear−expanding zone,and the equivalent strains increase significantly during the TCESE process of the AZ31 magnesium alloy.A extrusion temperature of 380°C and expanding ratio of 2.0 were selected as the optimized process parameters from the numerical simulation results.The average grain size of tubes fabricated by the TCESE process is approximately 10μm.The TCESE process can refine grains of magnesium alloy tubes with the occurrence of dynamic recrystallization.The(0001)basal texture intensities of the magnesium alloy tube blanks decrease due to continuous plastic deformation during the TCESE process.The average hardness of the extruded tubes is approximately HV 75,which is obviously improved.展开更多
BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer ...BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer involving the gastroesophageal junction and the gastric cardia. Anti-reflux stents with valve have been designed to prevent the acid reflux. The superiority of anti-reflux stent over standard stent in preventing gastroesophageal reflux has not been established well. This study compares the anti-reflux stent and the standard stent in terms of their efficacy to prevent acid reflux.AIM To compare the standard and the anti-reflux stents in terms of their efficacy,safety, and complications.METHODS The meta-analysis included 8 randomized clinical trials(RCTs) to compare pooled outcomes of total 395 patients. Primary outcomes include improvement in reflux symptoms and dysphagia score. Secondary outcomes include complications of stent migration, occlusion, and bleeding.RESULTS A total of eight RCTs were included in the meta-analysis. Compared to the standard stent, the anti-reflux stent showed a trend towards reduction in the dysphagia score without reaching a statistical significance [Standardized mean difference(SMD):-0.33(-0.71, 0.05); P = 0.09, I2: 37%]. There was no statistical difference in the gastrointestinal reflux(GER) scores between the two types of stents [SMD:-0.17(-0.78, 0.45); P = 0.008, I2: 74%]. Compared to standard stent,anti-reflux stent showed no difference in the risk of stent migration [OR: 1.37(0.66, 2.83); P = 0.40, I2: 0 %], bleeding [OR: 1.43(0.40, 5.13); P = 0.59, I2: 0 %], and obstruction [OR: 1.66(0.60, 4.60); P = 0.33, I2: 0 %].CONCLUSION Traditional self-expanding standard esophageal stent and anti-reflux stent with valve are similar in terms of outcomes and complications.展开更多
Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During rang...Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During range expansion, native species also encounter many new plant competitors. Thus, allelochemicals from native expanding species may also be more novel and allelopathic than those from non-expanding species to other plant competitors in the expanded range. We test this hypothesis using the native expanding Merremia boisiana and its non-expanding congener M. vitifolia in year 2012 inthe expanded range inHainan. In petridish bioassays, we found that aqueous extracts of M. boisiana leaves were often less inhibitory or more stimulatory to seed germination and seedling growth of five vegetable species than those of M. vitifolia leaves. In pot culture, we also found that aqueous leaf extracts of the two congeners could both inhibit the growth of a naturally co-occurring plant Paederia scanden, but their effects did not differ from each other. These results indicate that while allelopathy may contribute to the competitive ability of M. boisiana, it may not act as a novel weapon explaining its success in the expanded range in Hainan.展开更多
Dear Editor,There were an estimated 9.4 million patients with chronic hepatitis C virus(HCV)in China,putting a considerable burden on public health(Polaris Observatory HCV Collaborators,2022).What is more,the incidenc...Dear Editor,There were an estimated 9.4 million patients with chronic hepatitis C virus(HCV)in China,putting a considerable burden on public health(Polaris Observatory HCV Collaborators,2022).What is more,the incidence of HCV infection increased 14.5%every year based on data from China's National Notifiable Diseases Reporting System(Zhang et al.,2019).Approximately 75%of individuals infected with HCV develops chronic hepatitis,while long-term chronic HCV infection is the most important cause of liver fibrosis,cirrhosis,and hepatocellular carcinoma.展开更多
In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homot...In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homotopy analysis method （HAM） is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail.展开更多
On the basis of defining the concept of "immiserizing growth in expanding economies",through analysing the status quo of economy in China's rural areas in the new era,this paper aims to find out the fact...On the basis of defining the concept of "immiserizing growth in expanding economies",through analysing the status quo of economy in China's rural areas in the new era,this paper aims to find out the factors responsible for economic weakness of China's rural residents.It analyses the impact of market consuming economy on growth economy,and points out the phenomenon of "immiserizing growth in expanding economies" which may be triggered by China's rapid rural economic growth as follows:first,the income disparity between urban and rural residents increases ceaselessly,the commodity prices continuously soar,and the rural residents' market consuming capacity is short;second,the wealth concentrates highly and the majority of farmers' income is low.Thus we put forward the countermeasures and proposals for preventing "immiserizing growth in expanding economies" in rural areas as follows:we should reform household registration system so that the rural residents have the right to migrate freely,and farmers' status is promoted;we should coordinate urban-rural development,strengthen agriculture and rural infrastructure building and achieve impartial allocation of public resources;we should carry out redistribution on income scientifically and effectively,consolidate rural social security system,bridge urban-rural income gap,transform the comparative advantage into competitive advantage,so as to circumvent "immiserizing growth in expanding economies".展开更多
We extend two known dynamical systems obtained by Blaszak, et al. via choosing Casimir functions and utilizing Novikov-Lax equation so that a series of novel dynamical systems including generalized Burgers dynamical s...We extend two known dynamical systems obtained by Blaszak, et al. via choosing Casimir functions and utilizing Novikov-Lax equation so that a series of novel dynamical systems including generalized Burgers dynamical system, heat equation, and so on, are followed to be generated. Then we expand some differential operators presented in the paper to deduce two types of expanding dynamical models. By taking the generalized Burgers dynamical system as an example, we deform its expanding model to get a half-expanding system, whose recurrence operator is derived from Lax representation, and its Hamiltonian structure is also obtained by adopting a new way. Finally, we expand the generalized Burgers dynamical system to the （29-1）-dimensional case whose Hamiltonian structure is derived by Poisson tensor and gradient of the Casimir function. Besides, a kind of （29-1）-dimensional expanding dynamical model of the （29-1）-dimensionaJ dynamical system is generated as well.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52404155)State Key Laboratory of Mining Disaster Prevention and Control(Shandong University of Science and Technology)+1 种基金Ministry of Education(Grant No.JMDPC202402)supported by the opening project of State Key Laboratory of Explosion Science and Safety Protection(Beijing Institute of Technology).The opening project number is KFJJ24-20M.
文摘Aiming at mitigating the high risks associated with conventional explosive blasting,this study developed a safe directional fracturing technique,i.e.instantaneous expansion with a single fracture(IESF),using a coal-based solid waste expanding agent.First,the mechanism of directional fracturing blasting by the IESF was analyzed,and the criterion of directional crack initiation was established.On this basis,laboratory experiments and numerical simulations were conducted to systematically evaluate the directional fracturing blasting performance of the IESF.The results indicate that the IESF presents an excellent directional fracturing effect,with average surface undulation differences ranging from 8.1 mm to 22.7 mm on the fracture surfaces.Moreover,during concrete fracturing tests,the stresses and strains in the fracturing direction are measured to be 2.16-3.71 times and 8 times larger than those in the nonfracturing direction,respectively.Finally,the IESF technique was implemented for no-pillar mining with gob-side entry retaining through roof cutting and pressure relief in an underground coal mine.The IESF technique effectively created directional cracks in the roof without causing severe roadway deformation,achieving an average cutting rate and maximum roadway deformation of 94%and 197 mm,respectively.These on-site test results verified its excellent directional rock fracturing performance.The IESF technique,which is safe,efficient,and green,has considerable application prospects in the field of rock mechanics and engineering.
文摘Astronomical extreme events or phenomena include black holes as well as nebulae systems that resemble the Milky Way. Meteorological extreme events or phenomena include tornadoes and tropical cyclones. The new high energy state of matter expanding outwards by spin jets from the two poles of an astronomical black hole, the new high energy state of matter in a funnel-shaped vortex showed a meteorological tornado expanding downwards from a rotated disk of cumulonimbus clouds, the new high energy state of matter in a tropical cyclone and the new high energy state of a nebulae system converging celestial materials are phenomena across disciplines and multiple time-space scales that have not yet been physically explained. In this paper, the theory of orthogonal collision in the rotational contraction continuum is used to unify the understanding of diverse extreme events or phenomena through a single dynamical mechanism, offering insights into natural processes across disciplines. In the field of astronomy, the orthogonal collision of two-beam rotating and contracting particles or stars associated with centripetal forces forms a new high-energy state of matter at the collision point and the new high-energy particles have expanding forces outward to both sides of the collision plane. In the field of meteorology, the orthogonal collision of multiple horizontally rotating and contracting airflows associated with centripetal forces forms a new high energy state of matter at the collision point as well as an updraft force and a downdraft force vertically. The updraft force and downdraft force formed by the collision of anomalous wet airflows in the lower atmosphere can well indicate tornado, thunderstorm and extreme precipitation. The orthogonal collision theory can be applied to explain new states of matter in disciplines from the astronomical scale to the meteorological scale and the Planck scale.
基金supported by the National Natural Science Foundation of China(Grant Nos.62422503,62105080,22004016,and U22A2093)the Guangdong Basic and Applied Basic Research Foundation Regional Joint Fund(Grant Nos.2023A1515011944,2020B1515130006,and 2021B515120056)+1 种基金the Talent Recruitment Project of Guangdong(Grant No.2021QN02X179)the Science and Technology Innovation Commission of Shenzhen(Grant Nos.JCYJ20220531095604009 and RCYX20221008092907027).
文摘Confronting the escalating global challenge of counterfeit products,developing advanced anticounterfeiting materials and structures with physical unclonable functions(PUFs)has become imperative.All-optical PUFs,distinguished by their high output complexity and expansive response space,offer a promising alternative to conventional electronic counterparts.For practical authentications,the expansion of optical PUF keys usually involves intricate spatial or spectral shaping of excitation light using bulky external apparatus,which largely hinders the applications of optical PUFs.Here,we report a plasmonic PUF system based on heterogeneous nanostructures.The template-assisted shadow deposition technique was employed to adjust the morphological diversity of densely packed metal nanoparticles in individual PUFs.Transmission images were processed via a hash algorithm,and the generated PUF keys with a scalable capacity from 2875 to 243401 exhibit excellent uniqueness,randomness,and reproducibility.Furthermore,the wavelength and the polarization state of the excitation light are harnessed as two distinct expanding strategies,offering the potential for multiscenario applications via a single PUF.Overall,our reported plasmonic PUFs operated with the multidimensional expanding strategy are envisaged to serve as easy-to-integrate,easy-to-use systems and promise efficacy across a broad spectrum of applications,from anticounterfeiting to data encryption and authentication.
文摘Purpose:This study aims to foster a dialog between the experiences and identities of Nigerian female breast cancer survivors and Margaret Newman’s theory of health as expanding consciousness.The theory was employed to explore and describe the structure and meaning of these survivors’experiences and identities.Methods:Twenty-two participants were interviewed using a qualitative approach.The interviews were digitally recorded and transcribed verbatim.Data analysis was conducted using NVivo 14 software to identify recurring patterns within the data.Results:Three core themes emerged:(1)Encountering Selfhood-Otherhood in the survivorship journey,(2)navigating the rhythms of change,and(3)living the paradox of order and disorder.These themes reflect the unique and paradoxical rhythm of life as a breast cancer survivor,integrating these experiences conceptually.Conclusions:This study illuminates how Nigerian breast cancer survivors construct the patterns of meaning of their experiences by shifting the focus from solely evidence-based interventions to a deeper exploration of lived experience,cultural narratives,and expanding consciousness.Through compassionate and insightful nursing interactions,women can explore their evolving identities,foster resilience,and redefine their lives in meaningful and fulfilling ways within their unique contexts.Implications for Cancer Survivors:Greater attention is required to address the emotional,temporal,and economic dimensions of breast cancer survivorship in Nigeria.Nurses play a crucial role in helping survivors find meaning in their experiences,recognizing that order and disorder in life are integral to expanding consciousness.Survivors should be empowered to identify their patterns of living and leverage their strengths in navigating the survivorship journey and finding meaning in their lives.
基金Supported by National Key Research and Development Program of China(Grant No.2022YFB4700402).
文摘Existing mobile robots mostly use graph search algorithms for path planning,which suffer from relatively low planning efficiency owing to high redundancy and large computational complexity.Due to the limitations of the neighborhood search strategy,the robots could hardly obtain the most optimal global path.A global path planning algorithm,denoted as EDG*,is proposed by expanding nodes using a well-designed expanding disconnected graph operator(EDG)in this paper.Firstly,all obstacles are marked and their corners are located through the map pre-processing.Then,the EDG operator is designed to find points in non-obstruction areas to complete the rapid expansion of disconnected nodes.Finally,the EDG*heuristic iterative algorithm is proposed.It selects the candidate node through a specific valuation function and realizes the node expansion while avoiding collision with a minimum offset.Path planning experiments were conducted in a typical indoor environment and on the public dataset CSM.The result shows that the proposed EDG*reduced the planning time by more than 90%and total length of paths reduced by more than 4.6%.Compared to A*,Dijkstra and JPS,EDG*does not show an exponential explosion effect in map size.The EDG*showed better performance in terms of path smoothness,and collision avoidance.This shows that the EDG*algorithm proposed in this paper can improve the efficiency of path planning and enhance path quality.
文摘Additive manufacturing(AM),commonly known as 3D printing,has become a transformative technology that has a profound impact on various industrial sectors.AM encompasses a set of techniques for building objects layer by layer from digital models.Unlike conventional subtractive manufacturing methods that involve removing material from large blocks,AM adds material incrementally,providing unprecedented design flexibility and efficiency.
文摘The CICG President Du Zhanyuan shares his insights about China-Europe talent cooperation.THE history of exchange between China and Europe is long and profound.Since the 16th century,European thinkers represented by Voltaire,Bertrand Russell,and Arnold Joseph Toynbee have taken Chinese philosophy as a valuable complement to the European ideological system.China has also absorbed the ideas of European giants such as Adam Smith,Georg Wilhelm Friedrich Hegel,and Karl Marx for its transformation and progress.In recent years,exchanges and interactions between the two sides in various fields have become increasingly close.
文摘This work identifies the branch point, which was never explicit in EM treatises, from which came the choice of abandoning the Galilean transformations in favor of the Lorentz covariance, a path that originated the various relativistic theories. The need arising from the expanding Earth for a hydrodynamic mechanism for Newtonian and Coulomb fields is discussed. This hydrodynamic material mechanism is shown to constitute a completion of the Newton and Maxwell concepts of the fields, which were only a phenomenological description of physical reality. It is shown that the analogy between Maxwell’s equations and hydrodynamics cannot become a perfect correspondence. The lack of coupling of the electromagnetic field to the underlying material “causing field”—which induces hydrodynamical forces and accelerations observed only phenomenologically—gives rise to inaccuracies in the formulation of its equations, which are incorrect for Galilean covariance. But the most serious flaw in the original formulation of electromagnetism is the erroneous identification of the flow velocity of the field (variable as 1/r2) with the speed of light c, with which it was demonstrated that the fields of charges in motion contract in the direction of motion (the Heaviside ellipsoid, 1888, 1889). From this error, historically due to the incomplete development of many hydrodynamics sectors (a situation that persists today), came Fitz Gerald’s contractions and finally, the relativistic theories. Some future research lines are proposed for a return to realistic physics and a possible but still weak form of Galilean covariance.
文摘The hidden world of amyloid biology has suddenly snapped into atomic-level focus,revealing over 80 amyloid protein fibrils,both pathogenic and functional.Unlike globular proteins,amyloid proteins flatten and stack into unbranched fibrils.Stranger still,a single protein sequence can adopt wildly different two-dimensional conformations,yielding distinct fibril polymorphs.
文摘BACKGROUND Endoscopic management is the first-line therapy for post-liver-transplant anas-tomotic strictures.Although the optimal duration of treatment with plastic stents has been reported to be 8-12 months,data on safety and duration for metal stents in this setting is scarce.Due to limited access to endoscopic retrograde cholan-giopancreatography(ERCP)during the coronavirus disease 2019 pandemic in our centre,there was a change in practice towards increased usage and length-of-stay of the Kaffes biliary intraductal self-expanding stent in patients with suitable anatomy.This was mainly due to the theoretical benefit of Kaffes stents allowing for longer indwelling periods compared to the traditional plastic stents.METHODS Adult liver transplant recipients aged 18 years and above who underwent ERCP were retrospectively identified during a 10-year period through a database query.Unplanned admissions post-Kaffes stent insertion were identified manually through electronic and scanned medical records.The main outcome was the incidence of complications when stents were left indwelling for 3 months vs 6 months.Stent efficacy was calculated via rates of stricture recurrence between patients that had stenting courses for≤120 d or>120 d.RESULTS During the study period,a total of 66 ERCPs with Kaffes insertion were performed in 54 patients throughout their stenting course.In 33 ERCPs,the stent was removed or exchanged on a 3-month interval.No pancreatitis,perfor-ations or deaths occurred.Minor post-ERCP complications were similar between the 3-month(abdominal pain and intraductal migration)and 6-month(abdominal pain,septic shower and embedded stent)groups-6.1%vs 9.1%respectively,P=0.40.All strictures resolved at the end of the stenting course,but the stenting course was variable from 3 to 22 months.The recurrence rate for stenting courses lasting for up to 120 d was 71.4%and 21.4%for stenting courses of 121 d or over(P=0.03).There were 28 patients that were treated with a single ERCP with Kaffes,21 with removal after 120 d and 7 within 120 d.There was a significant improvement in stricture recurrence when the Kaffes was removed after 120 d when a single ERCP was used for the entire stenting course(71.0%vs 10.0%,P=0.01).CONCLUSION Utilising a single Kaffes intraductal fully-covered metal stent for at least 4 months is safe and efficacious for the management of post-transplant anastomotic strictures.
基金Project(2012zzts082)supported by the Fundamental Research Funds of Central South University,ChinaProject(02JJY2005)supported by the Natural Science Foundation of Hunan Province,ChinaProject(20130843023)supported by China Scholarship Council
文摘Based on the parametric analysis of the expanding zone of the vacuum dust suction mouth,the flow in the vacuum dust suction mouth was simulated by computational fluid dynamics(CFD)software,Fluent.The effects of the expanding zone parameters on flow simulation were analyzed.The results show that simulation effects depend on threshold values of the expanding zone parameters of the dust suction mouth,and the threshold values of the expanding zone can be obtained according to the different structures of the vacuum dust suction mouth and be selected as the geometric parameters in calculating,and also corners of the expanding zone make unobvious difference in calculation accuracy and in computational efficiency compared with no corner.The simulation results provide practical guidance to the flow simulation on the dust suction mouth.
文摘For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testing produces the uniform stress and strain rates but the testing is expensive. The Taylor test is relatively inexpensive but produces non-uniform stress and strain fields, and the results are not so easily inferred for material modeling. In the split-Hopkinson bar(SHB), which may be used in compression, tension and torsion testing, the strain rates never exceeds 103/s. In the present work, we use the expanding ring test where the strain rate is 104e105/s. A streak camera is used to examine the expanding ring velocity, and a water tank is used to collect the fragments. The experimental results are compared with the numerical simulations using the hydrocodes AUTODYN, IMPETUS Afea and a regularized smooth particle(RSPH) software. The number of fragments increases with the increase in the expansion velocity of the rings. The number of fragments is similar to the experimental results. The RSPH software shows much the same results as the AUTODYN where the Lagrangian solver is used for the ring. The IMPETUS Afea solver shows a somewhat different fragmentation characteristic due to the node splitting algorithm that induces pronounced tensile splitting.
文摘The two major challenges in industrial enzymatic catalysis are the limited number of chemical reaction types that are catalyzed by enzymes and the instability of enzymes under harsh conditions in industrial catalysis.Expanding enzyme catalysis to a larger substrate scope and greater variety of chemical reactions and tuning the microenvironment surrounding enzyme molecules to achieve high enzyme performance are urgently needed.In this account,we focus on our efforts using the de novo approach to synthesis hybrid enzyme catalysts that can address these two challenges and the structure-function relationship is discussed to reveal the principles of designing hybrid enzyme catalysts.We hope that this account will promote further efforts toward fundamental research and wide applications of designed enzyme hybrid catalysts for expanding biocatalysis.
基金financially supported by the National Natural Science Foundation of China (Nos.52071042,51771038)the Chongqing Talent Plan,China (No.CQYC202003047)Chongqing Natural Science Foundation,China (Nos.cstc2018jcyj AX0249,cstc2018jcyj AX0653)。
文摘A new severe plastic deformation method for manufacturing tubes made of AZ31 magnesium alloy with a large diameter was developed,which is called the TCESE(tube continuous extrusion−shear−expanding)process.The process combines direct extrusion with a two-step shear−expanding process.The influences of expanding ratios,extrusion temperatures on the deformation of finite element meshes,strain evolution and flow velocity of tube blanks during the TCESE process were researched based on numerical simulations by using DEFORM-3D software.Simulation results show that the maximum expanding ratio is 3.0 in the TCESE process.The deformation of finite element meshes of tube blanks is inhomogeneous in the shear−expanding zone,and the equivalent strains increase significantly during the TCESE process of the AZ31 magnesium alloy.A extrusion temperature of 380°C and expanding ratio of 2.0 were selected as the optimized process parameters from the numerical simulation results.The average grain size of tubes fabricated by the TCESE process is approximately 10μm.The TCESE process can refine grains of magnesium alloy tubes with the occurrence of dynamic recrystallization.The(0001)basal texture intensities of the magnesium alloy tube blanks decrease due to continuous plastic deformation during the TCESE process.The average hardness of the extruded tubes is approximately HV 75,which is obviously improved.
文摘BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer involving the gastroesophageal junction and the gastric cardia. Anti-reflux stents with valve have been designed to prevent the acid reflux. The superiority of anti-reflux stent over standard stent in preventing gastroesophageal reflux has not been established well. This study compares the anti-reflux stent and the standard stent in terms of their efficacy to prevent acid reflux.AIM To compare the standard and the anti-reflux stents in terms of their efficacy,safety, and complications.METHODS The meta-analysis included 8 randomized clinical trials(RCTs) to compare pooled outcomes of total 395 patients. Primary outcomes include improvement in reflux symptoms and dysphagia score. Secondary outcomes include complications of stent migration, occlusion, and bleeding.RESULTS A total of eight RCTs were included in the meta-analysis. Compared to the standard stent, the anti-reflux stent showed a trend towards reduction in the dysphagia score without reaching a statistical significance [Standardized mean difference(SMD):-0.33(-0.71, 0.05); P = 0.09, I2: 37%]. There was no statistical difference in the gastrointestinal reflux(GER) scores between the two types of stents [SMD:-0.17(-0.78, 0.45); P = 0.008, I2: 74%]. Compared to standard stent,anti-reflux stent showed no difference in the risk of stent migration [OR: 1.37(0.66, 2.83); P = 0.40, I2: 0 %], bleeding [OR: 1.43(0.40, 5.13); P = 0.59, I2: 0 %], and obstruction [OR: 1.66(0.60, 4.60); P = 0.33, I2: 0 %].CONCLUSION Traditional self-expanding standard esophageal stent and anti-reflux stent with valve are similar in terms of outcomes and complications.
文摘Exotic invaders may possess novel biochemical weapons that native plants do not have, and these novel biochemical weapons may be more allelopathic than those from native plants to other native competitors. During range expansion, native species also encounter many new plant competitors. Thus, allelochemicals from native expanding species may also be more novel and allelopathic than those from non-expanding species to other plant competitors in the expanded range. We test this hypothesis using the native expanding Merremia boisiana and its non-expanding congener M. vitifolia in year 2012 inthe expanded range inHainan. In petridish bioassays, we found that aqueous extracts of M. boisiana leaves were often less inhibitory or more stimulatory to seed germination and seedling growth of five vegetable species than those of M. vitifolia leaves. In pot culture, we also found that aqueous leaf extracts of the two congeners could both inhibit the growth of a naturally co-occurring plant Paederia scanden, but their effects did not differ from each other. These results indicate that while allelopathy may contribute to the competitive ability of M. boisiana, it may not act as a novel weapon explaining its success in the expanded range in Hainan.
基金supported by grants from National Natural Science Foundation of China (32000666 and 81772208)Guangdong Basic and Applied Research Foundation (2020A1515010118)Medical Science and Technology Research Foundation of Guangdong Province 2020 (B2020090)
文摘Dear Editor,There were an estimated 9.4 million patients with chronic hepatitis C virus(HCV)in China,putting a considerable burden on public health(Polaris Observatory HCV Collaborators,2022).What is more,the incidence of HCV infection increased 14.5%every year based on data from China's National Notifiable Diseases Reporting System(Zhang et al.,2019).Approximately 75%of individuals infected with HCV develops chronic hepatitis,while long-term chronic HCV infection is the most important cause of liver fibrosis,cirrhosis,and hepatocellular carcinoma.
基金supported by the National Natural Science Foundations of China (50936003, 50905013)The Open Project of State Key Lab. for Adv. Matals and Materials (2009Z-02)Research Foundation of Engineering Research Institute of USTB
文摘In this paper, the asymmetric laminar flow in a porous channel with expanding or contracting walls is investigated. The governing equations are reduced to ordinary ones by using suitable similar transformations. Homotopy analysis method （HAM） is employed to obtain the expres- sions for velocity fields. Graphs are sketched for values of parameters and associated dynamic characteristics, especially the expansion ratio, are analyzed in detail.
文摘On the basis of defining the concept of "immiserizing growth in expanding economies",through analysing the status quo of economy in China's rural areas in the new era,this paper aims to find out the factors responsible for economic weakness of China's rural residents.It analyses the impact of market consuming economy on growth economy,and points out the phenomenon of "immiserizing growth in expanding economies" which may be triggered by China's rapid rural economic growth as follows:first,the income disparity between urban and rural residents increases ceaselessly,the commodity prices continuously soar,and the rural residents' market consuming capacity is short;second,the wealth concentrates highly and the majority of farmers' income is low.Thus we put forward the countermeasures and proposals for preventing "immiserizing growth in expanding economies" in rural areas as follows:we should reform household registration system so that the rural residents have the right to migrate freely,and farmers' status is promoted;we should coordinate urban-rural development,strengthen agriculture and rural infrastructure building and achieve impartial allocation of public resources;we should carry out redistribution on income scientifically and effectively,consolidate rural social security system,bridge urban-rural income gap,transform the comparative advantage into competitive advantage,so as to circumvent "immiserizing growth in expanding economies".
基金Supported by the Fundamental Research Funds for the Central University under Grant No.2017XKZD11
文摘We extend two known dynamical systems obtained by Blaszak, et al. via choosing Casimir functions and utilizing Novikov-Lax equation so that a series of novel dynamical systems including generalized Burgers dynamical system, heat equation, and so on, are followed to be generated. Then we expand some differential operators presented in the paper to deduce two types of expanding dynamical models. By taking the generalized Burgers dynamical system as an example, we deform its expanding model to get a half-expanding system, whose recurrence operator is derived from Lax representation, and its Hamiltonian structure is also obtained by adopting a new way. Finally, we expand the generalized Burgers dynamical system to the （29-1）-dimensional case whose Hamiltonian structure is derived by Poisson tensor and gradient of the Casimir function. Besides, a kind of （29-1）-dimensional expanding dynamical model of the （29-1）-dimensionaJ dynamical system is generated as well.
