This study aims to solve the nonlinear fractional-order mathematical model(FOMM)by using the normal and dysregulated bone remodeling of themyeloma bone disease(MBD).For themore precise performance of the model,fractio...This study aims to solve the nonlinear fractional-order mathematical model(FOMM)by using the normal and dysregulated bone remodeling of themyeloma bone disease(MBD).For themore precise performance of the model,fractional-order derivatives have been used to solve the disease model numerically.The FOMM is preliminarily designed to focus on the critical interactions between bone resorption or osteoclasts(OC)and bone formation or osteoblasts(OB).The connections of OC and OB are represented by a nonlinear differential system based on the cellular components,which depict stable fluctuation in the usual bone case and unstable fluctuation through the MBD.Untreated myeloma causes by increasing the OC and reducing the osteoblasts,resulting in net bone waste the tumor growth.The solutions of the FOMM will be provided by using the stochastic framework based on the Levenberg-Marquardt backpropagation(LVMBP)neural networks(NN),i.e.,LVMBPNN.The mathematical performances of three variations of the fractional-order derivative based on the nonlinear disease model using the LVMPNN.The static structural performances are 82%for investigation and 9%for both learning and certification.The performances of the LVMBPNN are authenticated by using the results of the Adams-Bashforth-Moulton mechanism.To accomplish the capability,steadiness,accuracy,and ability of the LVMBPNN,the performances of the error histograms(EHs),mean square error(MSE),recurrence,and state transitions(STs)will be provided.展开更多
Stem cells possess the ability to divide symmetrically or asymmet- rically to allow for maintenance of the stem cell pool or become committed progenitors and differentiate into various cell lineages. The unique self-r...Stem cells possess the ability to divide symmetrically or asymmet- rically to allow for maintenance of the stem cell pool or become committed progenitors and differentiate into various cell lineages. The unique self-renewal capabilities and pluripotency of stem cells are integral to tissue regeneration and repair (Oh et al., 2014). Mul- tiple mechanisms including intracellular programs and extrinsic cues are reported to regulate neural stem cell (NSC) fate (Bond et al., 2015). A recent study, published in Cell Stern Cell, identified a novel mechanism whereby mitochondrial dynamics drive NSC fate (Khacho et al., 2016).展开更多
The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3...The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells. The stem cells give rise to three main progenitors: prepit, preneck and preparietal cells. Parietal cells develop either directly from the noncycling preparietal cells or less commonly via differentiation of the cycling prepit and preneck cell progenitors. The formation of a parietal cell is a sequential process which involves diminishment of glycocalyx, production of cytoplasmic tubulovesicles, an increase in number and length of microvilli, an increase in number and size of mitochondria, and fi nally, expansion and invagination of the apical membrane with the formation of an intracellular canalicular system. Little is known about the genetic counterparts of these morphological events. However, the time dimension of parietal cell production and the consequences of its alteration on the biological features of the gastric gland are well documented. The production of a new parietal cell takes about 2 d. However, mature parietal cells have a long lifespan during which they migrate bidirectionally while their functional activity for acid secretion gradually diminishes. Following an average lifespan of about 54 d, in mice, old parietal cells undergo degeneration and elimination. Various approaches for genetic alteration of the development of parietal cells have provided evidence in support of their role as governors of the stem/progenitor cell proliferation and differentiation programs. Revealing the dynamic features and the various roles of parietal cells would help in a better understanding of the biological features of the gastric glands and would hopefully help in providing a basis for the development of new strategies for prevention, early detection and/or therapy of various gastric disorders in which parietal cells are involved, such as atrophic gastritis, peptic ulcer disease and gastric cancer.展开更多
Current cell-based biosensors have progressed substantially from mere alternatives to molecular bioreceptors into enabling tools for interfacing molecular machineries and gene circuits with microelectronics and for de...Current cell-based biosensors have progressed substantially from mere alternatives to molecular bioreceptors into enabling tools for interfacing molecular machineries and gene circuits with microelectronics and for developing groundbreaking sensing and theragnostic platforms.The recent literature concerning whole-cell biosensors is reviewed with an emphasis on mammalian cells,and the challenges and breakthroughs brought along in biomedical analyses through novel biosensing concepts and the synthetic biology toolbox.These recent innovations allow development of cell-based biosensing platforms having tailored performances and capable to reach the levels of sensitivity,dynamic range,and stability suitable for high analytic/medical relevance.They also pave the way for the construction of flexible biosensing platforms with utility across biological research and clinical applications.The work is intended to stimulate interest in generation of cell-based biosensors and improve their acceptance and exploitation.展开更多
To evaluate the performance of basic shape representation methods for the description of dynamic cellular morphology, several frequently-used shape descriptors are compared. The methods are examined by using 50 lympho...To evaluate the performance of basic shape representation methods for the description of dynamic cellular morphology, several frequently-used shape descriptors are compared. The methods are examined by using 50 lymphocyte video clips including two kinds of lymphocyte cells. Our goal is to represent cell shape in each frame accurately, meanwhile precisely classify the two groups of cells based on the cellular morphological variations in the video clips. Experimental results illustrate that in general the region-based shape descriptors outperform the contour-based ones, since the contourbased methods are excessively sensitive and ignorant to cellular internal information. Due to their robustness to noise, the region-based shape descriptors are suitable for dynamic cell representation. Although region-based methods are more time-consuming, they analyze the entire cell area.展开更多
The dynamic load characteristics of a proton exchange membrane fuel cell(PEMFC) with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity...The dynamic load characteristics of a proton exchange membrane fuel cell(PEMFC) with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity of the cathode on the performances of the fuel cell were investigated. The obtained results show that, with different relative humidity of the cathode at 65 ℃, dynamic loading has little effect on the performances of fuel cell and the electrochemically active surface area(ECSA). However, the fuel cell operating under dynamic load is unstable when the relative humidity is 50%, and at 50 ℃ with 100% relative humidity, applying a dynamic load has a significant influence on the fuel cell performances. Scanning electron microscopy(SEM) showed that both the upstream and middle catalyst layers of the cell were unchanged, whereas the downstream cathode catalyst layer thinned as a response to dynamic load.展开更多
A repeated interdiffusion method is described for phase-stable and high-quality (FA,MA)PbI3 film. The crys- tallization and growth of the perovskite films can be well controlled by adjusting the reactant concentrati...A repeated interdiffusion method is described for phase-stable and high-quality (FA,MA)PbI3 film. The crys- tallization and growth of the perovskite films can be well controlled by adjusting the reactant concentrations. With this method, dense, smooth perovskite films with large crystals have been obtained. Finally, a PCE of 16.5% as well as a steady-state efficiency of 16.3% is achieved in the planar perovskite solar cell.展开更多
Single cell trapping in vitro by microfluidic device is an emerging approach for the study of the relationship between single cells and their dynamic biochemical microenvironments. In this paper, a hydrodynamic-based ...Single cell trapping in vitro by microfluidic device is an emerging approach for the study of the relationship between single cells and their dynamic biochemical microenvironments. In this paper, a hydrodynamic-based microfluidic device for single cell trapping is designed using a combination of stagnation point flow and physical barrier.The microfluidic device overcomes the weakness of the traditional ones, which have been only based upon either stagnation point flows or physical barriers, and can conveniently load dynamic biochemical signals to the trapped cell. In addition, it can connect with a programmable syringe pump and a microscope to constitute an integrated experimental system.It is experimentally verified that the microfluidic system can trap single cells in vitro even under flow disturbance and conveniently load biochemical signals to the trapped cell. The designed micro-device would provide a simple yet effective experimental platform for further study of the interactions between single cells and their microenvironments.展开更多
The phase transitions among the high-pressure polymorphic forms of CaCO_(3)(cc-Ⅰ,cc-Ⅱ,cc-Ⅲ,and cc-Ⅲb)are investigated by dynamic diamond anvil cell(dDAC)and in situ Raman spectroscopy.Experiments are carried out a...The phase transitions among the high-pressure polymorphic forms of CaCO_(3)(cc-Ⅰ,cc-Ⅱ,cc-Ⅲ,and cc-Ⅲb)are investigated by dynamic diamond anvil cell(dDAC)and in situ Raman spectroscopy.Experiments are carried out at room temperature and high pressures up to 12.8 GPa with the pressurizing rate varying from 0.006 GPa/s to 0.056 GPa/s.In situ observation shows that with the increase of pressure,calcite transforms from cc-Ⅰto cc-Ⅱat~1.5 GPa and from cc-Ⅱto cc-Ⅲat~2.5 GPa,and transitions are independent of the pressurizing rate.Further,as the pressure continues to increase,the cc-Ⅲb begins to appear and coexists with cc-Ⅲwithin a pressure range that is inversely proportional to the pressurizing rate.At the pressurizing rates of 0.006,0.012,0.021,and 0.056 GPa/s,the coexistence pressure ranges of cc-Ⅲand cc-Ⅲb are 2.8 GPa-9.8 GPa,3.1 GPa-6.9 GPa,2.7 GPa-6.0 GPa,and 2.8 GPa-4.5 GPa,respectively.The dependence of the coexistence on the pressurizing rate may result from the influence of pressurizing rate on the activation process of transition by reducing the energy barrier.The higher the pressurizing rate,the lower the energy barrier is,and the easier it is to pull the system out of the coexistence state.The results of this in situ study provide new insights into the understanding of the phase transition of calcite.展开更多
The polymer electrolyte membrane(PEM) fuel cell has been regarded as a potential alternative power source,and a model is necessary for its design,control and power management.A hybrid dynamic model of PEM fuel cell,...The polymer electrolyte membrane(PEM) fuel cell has been regarded as a potential alternative power source,and a model is necessary for its design,control and power management.A hybrid dynamic model of PEM fuel cell,which combines the advantages of mechanism model and black-box model,is proposed in this paper.To improve the performance,the static neural network and variable neural network are used to build the black-box model.The static neural network can significantly improve the static performance of the hybrid model,and the variable neural network makes the hybrid dynamic model predict the real PEM fuel cell behavior with required accuracy.Finally,the hybrid dynamic model is validated with a 500 W PEM fuel cell.The static and transient experiment results show that the hybrid dynamic model can predict the behavior of the fuel cell stack accurately and therefore can be effectively utilized in practical application.展开更多
Manufacturing systems are in a dynamically changing e nvironment with uncertainty. Management of complexity, changes and disturbances is one of the key issues of production. The traditional hierarchical control of CIM...Manufacturing systems are in a dynamically changing e nvironment with uncertainty. Management of complexity, changes and disturbances is one of the key issues of production. The traditional hierarchical control of CIM systems limits the agility and the flexibility of the shop floor control sys tems and makes the reconfiguration and maintenance of shop floor control systems need high cost and much time. So new architectures are required to meet these c hallenges for the shop floor control systems. Recent fundamental research in distributed artificial intelligence and related applied research in intelligent manufacturing systems have shown that the Multi -Agent based system is one of the most promising methods. In a multi-agent man ufacturing system, the agents react to the information acquired from environment and communicate with other agents to co-operate to solve the global problem. I n this paper, a framework of reconfigurable shop floor control system based on m ulti-agent is presented. The concept of dynamic and logical manufacturing cell is proposed to organize manufacturing resources to achieve the ability of re configuration in dynamic shop floor environment. The framework is composed of three levels. First, the level of shop floor comp rises order agent, resource management agent, product management agent and t ask agent. Second, the level of dynamical cells consists of production agents an d control agents. Finally, the resource agents, such as AGV agents and machine a gents, belong to the equipment level. The control architecture in the framework is different from hierarchical control. It is hybrids of hierarchical and hetera rchical control architecture. The Contract Net protocol and its bidding mechanism are suitable and efficient t o implement the dynamic and logical manufacturing cells. Based on the Contract N et Model, dynamic negotiation during the process of forming the dynamic and logi cal manufacturing cells is analyzed in the paper. In this paper the dynamic and logical manufacturing cell is the basis of the r econfiguration of multi-agent systems. It is organized in logical way while the traditional cell based on GT (group technology) is organized in physical way. I n the framework, resource agents are organized according to orders coming to sho p floor, and dismissed when the tasks are finished. Dynamically created cells ca n be overlapped in shop floor so that resource agents may belong to more than on e dynamic and logical manufacturing cells at a time. The order-oriented product ion agents and control agents that are created dynamically exist for the dur ation of the task and are destroyed when the task is completed. They have the li fecycle of creation, execution and destruction. Control agents are the coordinat ors and monitors that are responsible for organizing resource agents and monitor ing disturbances, but they are not strict controllers. They may recruit new reso urce agents into cells when disturbances such as machine breakdown appear. In the paper, the software architecture of shop floor control system based on Multi-Agent is also presented. And the distributed object technology based on C ORBA and KQML language are discussed.展开更多
Excitation wavelength dependent(Ex-De) luminescent materials have attracted intense attention due to their great potential in multicolor bioimaging,dynamic anti-counterfeiting,and light emitting devices.However,it rem...Excitation wavelength dependent(Ex-De) luminescent materials have attracted intense attention due to their great potential in multicolor bioimaging,dynamic anti-counterfeiting,and light emitting devices.However,it remains a formidable challenge to construct an Ex-De luminescent biomaterial with green starting materials,excellent biocompatibility,good water solubility,and multiple color emission for dynamic cell imaging.In this work,nanocomposites based on the facile self-assembly strategy of bovine serum albumin(BSA) and Au(Ⅰ)-complex are rationally designed and synthesized to simultaneously present Ex-De fluorescence(429–516 nm) and decent phosphorescence(~615 nm) in a dilute aqueous solution.Combinatory analyses of spectroscopic and microscopic results reveal that the luminescent mechanism of Au(Ⅰ)-BSA nanocomposites is cluster-induced Ex-De fluorescence and metal-to-ligand charge transition(MLCT) based phosphorescence.Importantly,based on the excellent biocompatibility,water-solubility and color-tunable emission over the entire visible region(360–800 nm),the Au(Ⅰ)-BSA nanocomposites are successfully used for cell imaging with multiple and switchable colors on demand.What is more,the solid tablets of Au(Ⅰ)-BSA nanoparticles showed pressure-responsive luminescence and decent room temperature phosphorescence.This work provides an assembling-induced emission strategy for the design of water-soluble,non-cytotoxic,and color-tunable luminescent biomaterials based on the composite of protein and Au nanoparticles.展开更多
A resolved CFD-DEM method is proposed to simulate the fluid-particle interaction for large complex granules.The airflow in a vertical sinter fixed bed is numerically studied using this method.The multi-sphere clumped ...A resolved CFD-DEM method is proposed to simulate the fluid-particle interaction for large complex granules.The airflow in a vertical sinter fixed bed is numerically studied using this method.The multi-sphere clumped method is used to create irregular sinter particles in DEM.The immersed boundary method and dynamic cell refinement are applied to describe the fluid flow around particles with higher resolution,by which the fluid-particle interaction can be simulated more accurately.The simulation results presented the packing voidage distributions and the airflow fields in the sinter beds of different single and mixed particle size ranges.The bed pressure drops were simulated and the results were compared with the corresponding experimental ones.The good agreement indicated that the proposed resolved CFD-DEM method is an effective tool to model the fluid-particle interaction for irregular large granules in the gas-solid multi-phase systems.展开更多
A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane w...A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane wave illumination,the resolution is increased by twofold to around 260 nm,while achieving millisecond-level temporal resolution.In HISTR-SAPM,digital micromirror devices are used to actively change the sample illumination beam angle at high speed with high stability.An off-axis interferometer is used to measure the sample scattered complex fields,which are then processed to reconstruct high-resolution phase images.Using HISTR-SAPM,we are able to map the height profiles of subwavelength photonic structures and resolve the period structures that have 198 nm linewidth and 132 nm gap(i.e.,a full pitch of 330 nm).As the reconstruction averages out laser speckle noise while maintaining high temporal resolution,HISTR-SAPM further enables imaging and quantification of nanoscale dynamics of live cells,such as red blood cell membrane fluctuations and subcellular structure dynamics within nucleated cells.We envision that HISTR-SAPM will broadly benefit research in material science and biology.展开更多
基金Thailand Science Research and Innovation(TSRI).Contract No.FRB650059/NMA/10the NSRF via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(grant number B05F640092).
文摘This study aims to solve the nonlinear fractional-order mathematical model(FOMM)by using the normal and dysregulated bone remodeling of themyeloma bone disease(MBD).For themore precise performance of the model,fractional-order derivatives have been used to solve the disease model numerically.The FOMM is preliminarily designed to focus on the critical interactions between bone resorption or osteoclasts(OC)and bone formation or osteoblasts(OB).The connections of OC and OB are represented by a nonlinear differential system based on the cellular components,which depict stable fluctuation in the usual bone case and unstable fluctuation through the MBD.Untreated myeloma causes by increasing the OC and reducing the osteoblasts,resulting in net bone waste the tumor growth.The solutions of the FOMM will be provided by using the stochastic framework based on the Levenberg-Marquardt backpropagation(LVMBP)neural networks(NN),i.e.,LVMBPNN.The mathematical performances of three variations of the fractional-order derivative based on the nonlinear disease model using the LVMPNN.The static structural performances are 82%for investigation and 9%for both learning and certification.The performances of the LVMBPNN are authenticated by using the results of the Adams-Bashforth-Moulton mechanism.To accomplish the capability,steadiness,accuracy,and ability of the LVMBPNN,the performances of the error histograms(EHs),mean square error(MSE),recurrence,and state transitions(STs)will be provided.
基金AJ-A is a Fonds de recherche du Québec-Santé(FRQS)scholarsupported by a grant from Natural Sciences and Engineering Research Council of Canada(NSERC RGPIN-2016-06605)
文摘Stem cells possess the ability to divide symmetrically or asymmet- rically to allow for maintenance of the stem cell pool or become committed progenitors and differentiate into various cell lineages. The unique self-renewal capabilities and pluripotency of stem cells are integral to tissue regeneration and repair (Oh et al., 2014). Mul- tiple mechanisms including intracellular programs and extrinsic cues are reported to regulate neural stem cell (NSC) fate (Bond et al., 2015). A recent study, published in Cell Stern Cell, identified a novel mechanism whereby mitochondrial dynamics drive NSC fate (Khacho et al., 2016).
基金Supported by Terry Fox Fund for Cancer Research and UAE University
文摘The fact that the acidsecreting parietal cells undergo continuous renewal has been ignored by many gastroenterologists and cell biologists. In the past, it was thought that these cells were static. However, by using 3Hthymidine radioautography in combination with electron microscopy, it was possible to demonstrate that parietal cells belong to a continuously renewing epithelial cell lineage. In the gastric glands, stem cells anchored in the isthmus region are responsible for the production of parietal cells. The stem cells give rise to three main progenitors: prepit, preneck and preparietal cells. Parietal cells develop either directly from the noncycling preparietal cells or less commonly via differentiation of the cycling prepit and preneck cell progenitors. The formation of a parietal cell is a sequential process which involves diminishment of glycocalyx, production of cytoplasmic tubulovesicles, an increase in number and length of microvilli, an increase in number and size of mitochondria, and fi nally, expansion and invagination of the apical membrane with the formation of an intracellular canalicular system. Little is known about the genetic counterparts of these morphological events. However, the time dimension of parietal cell production and the consequences of its alteration on the biological features of the gastric gland are well documented. The production of a new parietal cell takes about 2 d. However, mature parietal cells have a long lifespan during which they migrate bidirectionally while their functional activity for acid secretion gradually diminishes. Following an average lifespan of about 54 d, in mice, old parietal cells undergo degeneration and elimination. Various approaches for genetic alteration of the development of parietal cells have provided evidence in support of their role as governors of the stem/progenitor cell proliferation and differentiation programs. Revealing the dynamic features and the various roles of parietal cells would help in a better understanding of the biological features of the gastric glands and would hopefully help in providing a basis for the development of new strategies for prevention, early detection and/or therapy of various gastric disorders in which parietal cells are involved, such as atrophic gastritis, peptic ulcer disease and gastric cancer.
文摘Current cell-based biosensors have progressed substantially from mere alternatives to molecular bioreceptors into enabling tools for interfacing molecular machineries and gene circuits with microelectronics and for developing groundbreaking sensing and theragnostic platforms.The recent literature concerning whole-cell biosensors is reviewed with an emphasis on mammalian cells,and the challenges and breakthroughs brought along in biomedical analyses through novel biosensing concepts and the synthetic biology toolbox.These recent innovations allow development of cell-based biosensing platforms having tailored performances and capable to reach the levels of sensitivity,dynamic range,and stability suitable for high analytic/medical relevance.They also pave the way for the construction of flexible biosensing platforms with utility across biological research and clinical applications.The work is intended to stimulate interest in generation of cell-based biosensors and improve their acceptance and exploitation.
基金Supported by the National Natural Science Foundation of China(61271112)
文摘To evaluate the performance of basic shape representation methods for the description of dynamic cellular morphology, several frequently-used shape descriptors are compared. The methods are examined by using 50 lymphocyte video clips including two kinds of lymphocyte cells. Our goal is to represent cell shape in each frame accurately, meanwhile precisely classify the two groups of cells based on the cellular morphological variations in the video clips. Experimental results illustrate that in general the region-based shape descriptors outperform the contour-based ones, since the contourbased methods are excessively sensitive and ignorant to cellular internal information. Due to their robustness to noise, the region-based shape descriptors are suitable for dynamic cell representation. Although region-based methods are more time-consuming, they analyze the entire cell area.
基金Funded by the National Natural Science Foundation of China(Nos.51476119 and 51576147)the Natural Science Foundation of Hubei Province(No.2016CFA041)the Fundamental Research Funds for the Central Universities(No.2017 IVA 031)
文摘The dynamic load characteristics of a proton exchange membrane fuel cell(PEMFC) with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity of the cathode on the performances of the fuel cell were investigated. The obtained results show that, with different relative humidity of the cathode at 65 ℃, dynamic loading has little effect on the performances of fuel cell and the electrochemically active surface area(ECSA). However, the fuel cell operating under dynamic load is unstable when the relative humidity is 50%, and at 50 ℃ with 100% relative humidity, applying a dynamic load has a significant influence on the fuel cell performances. Scanning electron microscopy(SEM) showed that both the upstream and middle catalyst layers of the cell were unchanged, whereas the downstream cathode catalyst layer thinned as a response to dynamic load.
基金supported by the National Key Basic Research Program (No.2012CB932903)Natural Science Foundation of China (Nos. 51402348,51421002,91433205,21173260,11474333 and 91233202)
文摘A repeated interdiffusion method is described for phase-stable and high-quality (FA,MA)PbI3 film. The crys- tallization and growth of the perovskite films can be well controlled by adjusting the reactant concentrations. With this method, dense, smooth perovskite films with large crystals have been obtained. Finally, a PCE of 16.5% as well as a steady-state efficiency of 16.3% is achieved in the planar perovskite solar cell.
基金supported by the National Natural Science Foundation of China (Grants 11172060 and 31370948)
文摘Single cell trapping in vitro by microfluidic device is an emerging approach for the study of the relationship between single cells and their dynamic biochemical microenvironments. In this paper, a hydrodynamic-based microfluidic device for single cell trapping is designed using a combination of stagnation point flow and physical barrier.The microfluidic device overcomes the weakness of the traditional ones, which have been only based upon either stagnation point flows or physical barriers, and can conveniently load dynamic biochemical signals to the trapped cell. In addition, it can connect with a programmable syringe pump and a microscope to constitute an integrated experimental system.It is experimentally verified that the microfluidic system can trap single cells in vitro even under flow disturbance and conveniently load biochemical signals to the trapped cell. The designed micro-device would provide a simple yet effective experimental platform for further study of the interactions between single cells and their microenvironments.
基金Project supported by the Fund from the Chinese Academy of Sciences (Grant No. QYZDY-SSW-DQC029)the National Natural Science Foundation of China (Grant No. 41674097)
文摘The phase transitions among the high-pressure polymorphic forms of CaCO_(3)(cc-Ⅰ,cc-Ⅱ,cc-Ⅲ,and cc-Ⅲb)are investigated by dynamic diamond anvil cell(dDAC)and in situ Raman spectroscopy.Experiments are carried out at room temperature and high pressures up to 12.8 GPa with the pressurizing rate varying from 0.006 GPa/s to 0.056 GPa/s.In situ observation shows that with the increase of pressure,calcite transforms from cc-Ⅰto cc-Ⅱat~1.5 GPa and from cc-Ⅱto cc-Ⅲat~2.5 GPa,and transitions are independent of the pressurizing rate.Further,as the pressure continues to increase,the cc-Ⅲb begins to appear and coexists with cc-Ⅲwithin a pressure range that is inversely proportional to the pressurizing rate.At the pressurizing rates of 0.006,0.012,0.021,and 0.056 GPa/s,the coexistence pressure ranges of cc-Ⅲand cc-Ⅲb are 2.8 GPa-9.8 GPa,3.1 GPa-6.9 GPa,2.7 GPa-6.0 GPa,and 2.8 GPa-4.5 GPa,respectively.The dependence of the coexistence on the pressurizing rate may result from the influence of pressurizing rate on the activation process of transition by reducing the energy barrier.The higher the pressurizing rate,the lower the energy barrier is,and the easier it is to pull the system out of the coexistence state.The results of this in situ study provide new insights into the understanding of the phase transition of calcite.
基金Supported by the National Science Fund for Distinguished Young Scholars of China (60925011)
文摘The polymer electrolyte membrane(PEM) fuel cell has been regarded as a potential alternative power source,and a model is necessary for its design,control and power management.A hybrid dynamic model of PEM fuel cell,which combines the advantages of mechanism model and black-box model,is proposed in this paper.To improve the performance,the static neural network and variable neural network are used to build the black-box model.The static neural network can significantly improve the static performance of the hybrid model,and the variable neural network makes the hybrid dynamic model predict the real PEM fuel cell behavior with required accuracy.Finally,the hybrid dynamic model is validated with a 500 W PEM fuel cell.The static and transient experiment results show that the hybrid dynamic model can predict the behavior of the fuel cell stack accurately and therefore can be effectively utilized in practical application.
文摘Manufacturing systems are in a dynamically changing e nvironment with uncertainty. Management of complexity, changes and disturbances is one of the key issues of production. The traditional hierarchical control of CIM systems limits the agility and the flexibility of the shop floor control sys tems and makes the reconfiguration and maintenance of shop floor control systems need high cost and much time. So new architectures are required to meet these c hallenges for the shop floor control systems. Recent fundamental research in distributed artificial intelligence and related applied research in intelligent manufacturing systems have shown that the Multi -Agent based system is one of the most promising methods. In a multi-agent man ufacturing system, the agents react to the information acquired from environment and communicate with other agents to co-operate to solve the global problem. I n this paper, a framework of reconfigurable shop floor control system based on m ulti-agent is presented. The concept of dynamic and logical manufacturing cell is proposed to organize manufacturing resources to achieve the ability of re configuration in dynamic shop floor environment. The framework is composed of three levels. First, the level of shop floor comp rises order agent, resource management agent, product management agent and t ask agent. Second, the level of dynamical cells consists of production agents an d control agents. Finally, the resource agents, such as AGV agents and machine a gents, belong to the equipment level. The control architecture in the framework is different from hierarchical control. It is hybrids of hierarchical and hetera rchical control architecture. The Contract Net protocol and its bidding mechanism are suitable and efficient t o implement the dynamic and logical manufacturing cells. Based on the Contract N et Model, dynamic negotiation during the process of forming the dynamic and logi cal manufacturing cells is analyzed in the paper. In this paper the dynamic and logical manufacturing cell is the basis of the r econfiguration of multi-agent systems. It is organized in logical way while the traditional cell based on GT (group technology) is organized in physical way. I n the framework, resource agents are organized according to orders coming to sho p floor, and dismissed when the tasks are finished. Dynamically created cells ca n be overlapped in shop floor so that resource agents may belong to more than on e dynamic and logical manufacturing cells at a time. The order-oriented product ion agents and control agents that are created dynamically exist for the dur ation of the task and are destroyed when the task is completed. They have the li fecycle of creation, execution and destruction. Control agents are the coordinat ors and monitors that are responsible for organizing resource agents and monitor ing disturbances, but they are not strict controllers. They may recruit new reso urce agents into cells when disturbances such as machine breakdown appear. In the paper, the software architecture of shop floor control system based on Multi-Agent is also presented. And the distributed object technology based on C ORBA and KQML language are discussed.
基金supported by the National Natural Science Foundation of China(22101208,22125803,22020102006)the Fundamental Research Funds for the Central Universitiesthe Program for Professors of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Excitation wavelength dependent(Ex-De) luminescent materials have attracted intense attention due to their great potential in multicolor bioimaging,dynamic anti-counterfeiting,and light emitting devices.However,it remains a formidable challenge to construct an Ex-De luminescent biomaterial with green starting materials,excellent biocompatibility,good water solubility,and multiple color emission for dynamic cell imaging.In this work,nanocomposites based on the facile self-assembly strategy of bovine serum albumin(BSA) and Au(Ⅰ)-complex are rationally designed and synthesized to simultaneously present Ex-De fluorescence(429–516 nm) and decent phosphorescence(~615 nm) in a dilute aqueous solution.Combinatory analyses of spectroscopic and microscopic results reveal that the luminescent mechanism of Au(Ⅰ)-BSA nanocomposites is cluster-induced Ex-De fluorescence and metal-to-ligand charge transition(MLCT) based phosphorescence.Importantly,based on the excellent biocompatibility,water-solubility and color-tunable emission over the entire visible region(360–800 nm),the Au(Ⅰ)-BSA nanocomposites are successfully used for cell imaging with multiple and switchable colors on demand.What is more,the solid tablets of Au(Ⅰ)-BSA nanoparticles showed pressure-responsive luminescence and decent room temperature phosphorescence.This work provides an assembling-induced emission strategy for the design of water-soluble,non-cytotoxic,and color-tunable luminescent biomaterials based on the composite of protein and Au nanoparticles.
基金the financial support for this work from the National Natural Science Foundation of China(grant No.52104340)China Postdoctoral Science Foundation(grant No.2020M672425)+1 种基金The Key Research and Development Program of Hubei Province(grant No.2022BCA058)Natural Science Foundation of Hubei Province(grant No.2020CFB133).
文摘A resolved CFD-DEM method is proposed to simulate the fluid-particle interaction for large complex granules.The airflow in a vertical sinter fixed bed is numerically studied using this method.The multi-sphere clumped method is used to create irregular sinter particles in DEM.The immersed boundary method and dynamic cell refinement are applied to describe the fluid flow around particles with higher resolution,by which the fluid-particle interaction can be simulated more accurately.The simulation results presented the packing voidage distributions and the airflow fields in the sinter beds of different single and mixed particle size ranges.The bed pressure drops were simulated and the results were compared with the corresponding experimental ones.The good agreement indicated that the proposed resolved CFD-DEM method is an effective tool to model the fluid-particle interaction for irregular large granules in the gas-solid multi-phase systems.
基金We acknowledge financial support from Hong Kong Innovation and Technology Fund(Nos.ITS/394/17 and ITS/098/18FP)Shun Hing Institute of Advanced Engineering(No.BME-p3-18)Croucher Innovation Awards 2019,and the U.S.National Institutes of Health(No.5P41EB015871-33).
文摘A new optical microscopy technique,termed high spatial and temporal resolution synthetic aperture phase microscopy(HISTR-SAPM),is proposed to improve the lateral resolution of wide-field coherent imaging.Under plane wave illumination,the resolution is increased by twofold to around 260 nm,while achieving millisecond-level temporal resolution.In HISTR-SAPM,digital micromirror devices are used to actively change the sample illumination beam angle at high speed with high stability.An off-axis interferometer is used to measure the sample scattered complex fields,which are then processed to reconstruct high-resolution phase images.Using HISTR-SAPM,we are able to map the height profiles of subwavelength photonic structures and resolve the period structures that have 198 nm linewidth and 132 nm gap(i.e.,a full pitch of 330 nm).As the reconstruction averages out laser speckle noise while maintaining high temporal resolution,HISTR-SAPM further enables imaging and quantification of nanoscale dynamics of live cells,such as red blood cell membrane fluctuations and subcellular structure dynamics within nucleated cells.We envision that HISTR-SAPM will broadly benefit research in material science and biology.