Based on a pseudo-spectral large eddy simulation (LES) model, an LES model with an anisotropy turbulent kinetic energy (TKE) closure model and an explicit multi-stage third-order Runge-Kutta scheme is established. The...Based on a pseudo-spectral large eddy simulation (LES) model, an LES model with an anisotropy turbulent kinetic energy (TKE) closure model and an explicit multi-stage third-order Runge-Kutta scheme is established. The modeling and analysis show that the LES model can simulate the planetary boundary layer (PBL) with a uniform underlying surface under various stratifications very well. Then, similar to the description of a forest canopy, the drag term on momentum and the production term of TKE by subgrid city buildings are introduced into the LES equations to account for the area-averaged effect of the subgrid urban canopy elements and to simulate the meteorological fields of the urban boundary layer (UBL). Numerical experiments and comparison analysis show that: (1) the result from the LES of the UBL with a proposed formula for the drag coefficient is consistent and comparable with that from wind tunnel experiments and an urban subdomain scale model; (2) due to the effect of urban buildings, the wind velocity near the canopy is decreased, turbulence is intensified, TKE, variance, and momentum flux are increased, the momentum and heat flux at the top of the PBL are increased, and the development of the PBL is quickened; (3) the height of the roughness sublayer (RS) of the actual city buildings is the maximum building height (1.5-3 times the mean building height), and a constant flux layer (CFL) exists in the lower part of the UBL.展开更多
Poly(3-hydroxy butyrate)-co-(3-hydroxy valerate)(PHBV)is a biobased and biodegradable polyester.This semicrystalline bioplastic could be a good candidate for the replacement of some commodity plastics derived from oil...Poly(3-hydroxy butyrate)-co-(3-hydroxy valerate)(PHBV)is a biobased and biodegradable polyester.This semicrystalline bioplastic could be a good candidate for the replacement of some commodity plastics derived from oil.However,the control of the conditions of its processing in order to obtain optimal properties of the finished products remains a current research subject.The objective of this work is to better understand the crystallization under injection molding conditions by inline measurements during the process.We focused on the influence of two key processing parameters,namely,mold temperature and packing pressure.The modeling of inline temperature measurements allowed an inverse estimation of the thermodynamic melting temperature of PHBV and of the heat of crystallization’s variations with processing parameters.展开更多
Natural rubber(NR),besides being an abundant renewable resource for the elastomer industry,can be a potential resource for the design of innovative biobased polymer networks.The present work is based on“telechelic”l...Natural rubber(NR),besides being an abundant renewable resource for the elastomer industry,can be a potential resource for the design of innovative biobased polymer networks.The present work is based on“telechelic”liquid natural rubber oligomers obtained by controlled chemical degradation of NR.The chain ends of such oligomers can then be functionalized(with acrylate functions in the present case)and reacted with multifunctional crosslinkers in order to form networks.What’s more,the initial solubility of such thermosetting system in an ionic liquid(IL)can be used for the formulation of ionogels.Such solid networks typically containing 80%of IL were produced,resulting in high ionic conductivity performances.The oligomer chain length was shown to affect IL fragility due to confinement and specific interactions of ions with the host polymer network.展开更多
In this article it is investigated the case of a three-part ultimatum game,where the proposer makes repeated sharing suggestions to the responder and a"third".This"third"is the regulatory factor of...In this article it is investigated the case of a three-part ultimatum game,where the proposer makes repeated sharing suggestions to the responder and a"third".This"third"is the regulatory factor of recurring bids,at a rate-at each time of the immediately preceding.This article answers to question like"what share would the proposer be willing to give to the responder in the case of three taking part in the ultimatum game?"Which would be moral and which fair?At which point of distribution would it be accepted by the responder?A Chi Square(x^(2))test is used.For this reason,after investigating the social integration factors through the literature,two small surveys trying to identify the distribution rate are conducted.We conclude that a share 0.40 could be accepted by the responder and the"third".展开更多
We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model.This study confirms the nonlocal feature of the hyperon weak radiative transition operators,which are domin...We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model.This study confirms the nonlocal feature of the hyperon weak radiative transition operators,which are dominated by the pole terms,and an overall self-consistent description of the available experimental data for the Cabibbofavored hyperon weak radiative decays is presented.It provides a natural mechanism for evading the Hara theorem,where sizeable parity-violating contributions can come from the intermediate orbital excitations.Cancellations between pole terms also explain the significant SU(3)flavor symmetry breaking manifested by the experimental data.We also discuss several interesting selection rules arising from either the electromagnetic or the weak interaction vertices.These features suggest nontrivial relations among various hyperon decays.展开更多
Peptide-based nanostructures have received much attention in the field of drug targeting. In fact, peptides have many advantages such as simplicity of the structure, biocompatibility, and chemical diversity. Moreover,...Peptide-based nanostructures have received much attention in the field of drug targeting. In fact, peptides have many advantages such as simplicity of the structure, biocompatibility, and chemical diversity. Moreover, some peptides, which are called cell-penetrating peptides, can cross cellular membranes and carry small molecules, small interfering RNA, or viruses inside live cells. These molecules are often covalently or noncovalently linked to cargoes, thus forming amphiphilic conjugates that can self-assemble. Supramolecular nanostructures formed from peptides are used in nanomedicine as a carrier to protect a drug and to target cancer cells. This review explores aliphatic-chain-conjugated peptides and drug-conjugated peptides that can self-assemble. Special emphasis is placed on the synthesis procedure, nanostructure formation, and biological activity.展开更多
The increasing deployment of deep learning models for distinguishing weeds and crops has witnessed notable strides in agricultural scenarios.However,a conspicuous gap endures in the literature concerning the training ...The increasing deployment of deep learning models for distinguishing weeds and crops has witnessed notable strides in agricultural scenarios.However,a conspicuous gap endures in the literature concerning the training and testing of models across disparate environmental conditions.Predominant methodologies either delineate a single dataset distribution into training,validation,and testing subsets or merge datasets from diverse condi-tions or distributions before their division into the subsets.Our study aims to ameliorate this gap by extending to several broadleaf weed categories across varied distributions,evaluating the impact of training convolutional neural networks on datasets specific to particular conditions or distributions,and assessing their performance in entirely distinct settings through three experiments.By evaluating diverse network architectures and training approaches(finetuning versus feature extraction),testing various architectures,employing different training strategies,and amalgamating data,we devised straightforward guidelines to ensure the model's deployability in contrasting environments with sustained precision and accuracy.In Experiment 1,conducted in a uniform environment,accuracy ranged from 80%to 100%across all models and training strategies,with finetune mode achieving a superior performance of 94%to 99.9%compared to the feature extraction mode at 80%to 92.96%.Experiment 2 underscored a significant performance decline,with accuracy fig-ures between 25%and 60%,primarily at 40%,when the origin of the test data deviated from the train and valida-tion sets.Experiment 3,spotlighting dataset and distribution amalgamation,yielded promising accuracy metrics,notably a peak of 99.6%for ResNet in finetuning mode to a low of 69.9%for InceptionV3 in feature extraction mode.These pivotal findings emphasize that merging data from diverse distributions,coupled with finetuned training on advanced architectures like ResNet and MobileNet,markedly enhances performance,contrasting with the rel-atively lower performance exhibited by simpler networks like AlexNet.Our results suggest that embracing data diversity and flexible training methodologies are crucial for optimizing weed classification models when dispa-rate data distributions are available.This study gives a practical alternative for treating diverse datasets with real-world agricultural variances.展开更多
基金The research was supported by the National Natural Science Foundation of China under Grant Nos.40333027 and 40075004.
文摘Based on a pseudo-spectral large eddy simulation (LES) model, an LES model with an anisotropy turbulent kinetic energy (TKE) closure model and an explicit multi-stage third-order Runge-Kutta scheme is established. The modeling and analysis show that the LES model can simulate the planetary boundary layer (PBL) with a uniform underlying surface under various stratifications very well. Then, similar to the description of a forest canopy, the drag term on momentum and the production term of TKE by subgrid city buildings are introduced into the LES equations to account for the area-averaged effect of the subgrid urban canopy elements and to simulate the meteorological fields of the urban boundary layer (UBL). Numerical experiments and comparison analysis show that: (1) the result from the LES of the UBL with a proposed formula for the drag coefficient is consistent and comparable with that from wind tunnel experiments and an urban subdomain scale model; (2) due to the effect of urban buildings, the wind velocity near the canopy is decreased, turbulence is intensified, TKE, variance, and momentum flux are increased, the momentum and heat flux at the top of the PBL are increased, and the development of the PBL is quickened; (3) the height of the roughness sublayer (RS) of the actual city buildings is the maximum building height (1.5-3 times the mean building height), and a constant flux layer (CFL) exists in the lower part of the UBL.
文摘Poly(3-hydroxy butyrate)-co-(3-hydroxy valerate)(PHBV)is a biobased and biodegradable polyester.This semicrystalline bioplastic could be a good candidate for the replacement of some commodity plastics derived from oil.However,the control of the conditions of its processing in order to obtain optimal properties of the finished products remains a current research subject.The objective of this work is to better understand the crystallization under injection molding conditions by inline measurements during the process.We focused on the influence of two key processing parameters,namely,mold temperature and packing pressure.The modeling of inline temperature measurements allowed an inverse estimation of the thermodynamic melting temperature of PHBV and of the heat of crystallization’s variations with processing parameters.
文摘Natural rubber(NR),besides being an abundant renewable resource for the elastomer industry,can be a potential resource for the design of innovative biobased polymer networks.The present work is based on“telechelic”liquid natural rubber oligomers obtained by controlled chemical degradation of NR.The chain ends of such oligomers can then be functionalized(with acrylate functions in the present case)and reacted with multifunctional crosslinkers in order to form networks.What’s more,the initial solubility of such thermosetting system in an ionic liquid(IL)can be used for the formulation of ionogels.Such solid networks typically containing 80%of IL were produced,resulting in high ionic conductivity performances.The oligomer chain length was shown to affect IL fragility due to confinement and specific interactions of ions with the host polymer network.
文摘In this article it is investigated the case of a three-part ultimatum game,where the proposer makes repeated sharing suggestions to the responder and a"third".This"third"is the regulatory factor of recurring bids,at a rate-at each time of the immediately preceding.This article answers to question like"what share would the proposer be willing to give to the responder in the case of three taking part in the ultimatum game?"Which would be moral and which fair?At which point of distribution would it be accepted by the responder?A Chi Square(x^(2))test is used.For this reason,after investigating the social integration factors through the literature,two small surveys trying to identify the distribution rate are conducted.We conclude that a share 0.40 could be accepted by the responder and the"third".
基金Supported by the National Natural Science Foundation of China(11425525,11521505)DFG and NSFC funds to the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”(NSFC)(11261130311)+3 种基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB34030302)National Key Basic Research Program of China(2015CB856700)supported by the research startup funding at SCNU,Guangdong Provincial funding with(2019QN01X172)Science and Technology Program of Guangzhou(2019050001)。
文摘We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model.This study confirms the nonlocal feature of the hyperon weak radiative transition operators,which are dominated by the pole terms,and an overall self-consistent description of the available experimental data for the Cabibbofavored hyperon weak radiative decays is presented.It provides a natural mechanism for evading the Hara theorem,where sizeable parity-violating contributions can come from the intermediate orbital excitations.Cancellations between pole terms also explain the significant SU(3)flavor symmetry breaking manifested by the experimental data.We also discuss several interesting selection rules arising from either the electromagnetic or the weak interaction vertices.These features suggest nontrivial relations among various hyperon decays.
文摘Peptide-based nanostructures have received much attention in the field of drug targeting. In fact, peptides have many advantages such as simplicity of the structure, biocompatibility, and chemical diversity. Moreover, some peptides, which are called cell-penetrating peptides, can cross cellular membranes and carry small molecules, small interfering RNA, or viruses inside live cells. These molecules are often covalently or noncovalently linked to cargoes, thus forming amphiphilic conjugates that can self-assemble. Supramolecular nanostructures formed from peptides are used in nanomedicine as a carrier to protect a drug and to target cancer cells. This review explores aliphatic-chain-conjugated peptides and drug-conjugated peptides that can self-assemble. Special emphasis is placed on the synthesis procedure, nanostructure formation, and biological activity.
基金part of the“New elements of integrated weed management in the south-central zone of Chile”,project 502602-70,financed by the Ministry of Agriculture of Chile.
文摘The increasing deployment of deep learning models for distinguishing weeds and crops has witnessed notable strides in agricultural scenarios.However,a conspicuous gap endures in the literature concerning the training and testing of models across disparate environmental conditions.Predominant methodologies either delineate a single dataset distribution into training,validation,and testing subsets or merge datasets from diverse condi-tions or distributions before their division into the subsets.Our study aims to ameliorate this gap by extending to several broadleaf weed categories across varied distributions,evaluating the impact of training convolutional neural networks on datasets specific to particular conditions or distributions,and assessing their performance in entirely distinct settings through three experiments.By evaluating diverse network architectures and training approaches(finetuning versus feature extraction),testing various architectures,employing different training strategies,and amalgamating data,we devised straightforward guidelines to ensure the model's deployability in contrasting environments with sustained precision and accuracy.In Experiment 1,conducted in a uniform environment,accuracy ranged from 80%to 100%across all models and training strategies,with finetune mode achieving a superior performance of 94%to 99.9%compared to the feature extraction mode at 80%to 92.96%.Experiment 2 underscored a significant performance decline,with accuracy fig-ures between 25%and 60%,primarily at 40%,when the origin of the test data deviated from the train and valida-tion sets.Experiment 3,spotlighting dataset and distribution amalgamation,yielded promising accuracy metrics,notably a peak of 99.6%for ResNet in finetuning mode to a low of 69.9%for InceptionV3 in feature extraction mode.These pivotal findings emphasize that merging data from diverse distributions,coupled with finetuned training on advanced architectures like ResNet and MobileNet,markedly enhances performance,contrasting with the rel-atively lower performance exhibited by simpler networks like AlexNet.Our results suggest that embracing data diversity and flexible training methodologies are crucial for optimizing weed classification models when dispa-rate data distributions are available.This study gives a practical alternative for treating diverse datasets with real-world agricultural variances.
