The current problems facing literary criticism are not only the influence of the external environment,but also the understanding of the traditional Chinese culture from the perspective of“globalization”and“diversif...The current problems facing literary criticism are not only the influence of the external environment,but also the understanding of the traditional Chinese culture from the perspective of“globalization”and“diversification”of literature.It is also a guide for related literary criticism.This paper first discusses the pluralism of literary criticism,gives an overview of literary criticism,analyzes the problems of literary criticism in Chinese literature in our country,and finally propoeses relevant suggestions for literary criticism under pluralism.展开更多
X-ray diffraction(XRD)data acquisition and analysis is among the most time-consuming steps in the development cycle of novel thin-film materials.We propose a machine learning-enabled approach to predict crystallograph...X-ray diffraction(XRD)data acquisition and analysis is among the most time-consuming steps in the development cycle of novel thin-film materials.We propose a machine learning-enabled approach to predict crystallographic dimensionality and space group from a limited number of thin-film XRD patterns.We overcome the scarce data problem intrinsic to novel materials development by coupling a supervised machine learning approach with a model-agnostic,physics-informed data augmentation strategy using simulated data from the Inorganic Crystal Structure Database(ICSD)and experimental data.As a test case,115 thin-film metalhalides spanning three dimensionalities and seven space groups are synthesized and classified.After testing various algorithms,we develop and implement an all convolutional neural network,with cross-validated accuracies for dimensionality and space group classification of 93 and 89%,respectively.We propose average class activation maps,computed from a global average pooling layer,to allow high model interpretability by human experimentalists,elucidating the root causes of misclassification.Finally,we systematically evaluate the maximum XRD pattern step size(data acquisition rate)before loss of predictive accuracy occurs,and determine it to be 0.16°2θ,which enables an XRD pattern to be obtained and classified in 5.5 min or less.展开更多
Bayesian optimization(BO)has been leveraged for guiding autonomous and high-throughput experiments in materials science.However,few have evaluated the efficiency of BO across a broad range of experimental materials do...Bayesian optimization(BO)has been leveraged for guiding autonomous and high-throughput experiments in materials science.However,few have evaluated the efficiency of BO across a broad range of experimental materials domains.In this work,we quantify the performance of BO with a collection of surrogate model and acquisition function pairs across five diverse experimental materials systems.By defining acceleration and enhancement metrics for materials optimization objectives,we find that surrogate models such as Gaussian Process(GP)with anisotropic kernels and Random Forest(RF)have comparable performance in BO,and both outperform the commonly used GP with isotropic kernels.GP with anisotropic kernels has demonstrated the most robustness,yet RF is a close alternative and warrants more consideration because it is free from distribution assumptions,has smaller time complexity,and requires less effort in initial hyperparameter selection.We also raise awareness about the benefits of using GP with anisotropic kernels in future materials optimization campaigns.展开更多
Process optimization of photovoltaic devices is a time-intensive,trial-and-error endeavor,which lacks full transparency of the underlying physics and relies on user-imposed constraints that may or may not lead to a gl...Process optimization of photovoltaic devices is a time-intensive,trial-and-error endeavor,which lacks full transparency of the underlying physics and relies on user-imposed constraints that may or may not lead to a global optimum.Herein,we demonstrate that embedding physics domain knowledge into a Bayesian network enables an optimization approach for gallium arsenide(GaAs)solar cells that identifies the root cause(s)of underperformance with layer-by-layer resolution and reveals alternative optimal process windows beyond traditional black-box optimization.Our Bayesian network approach links a key GaAs process variable(growth temperature)to material descriptors(bulk and interface properties,e.g.,bulk lifetime,doping,and surface recombination)and device performance parameters(e.g.,cell efficiency).For this purpose,we combine a Bayesian inference framework with a neural network surrogate device-physics model that is 100×faster than numerical solvers.With the trained surrogate model and only a small number of experimental samples,our approach reduces significantly the time-consuming intervention and characterization required by the experimentalist.As a demonstration of our method,in only five metal organic chemical vapor depositions,we identify a superior growth temperature profile for the window,bulk,and back surface field layer of a GaAs solar cell,without any secondary measurements,and demonstrate a 6.5%relative AM1.5G efficiency improvement above traditional grid search methods.展开更多
While machine learning(ML)in experimental research has demonstrated impressive predictive capabilities,extracting fungible knowledge representations from experimental data remains an elusive task.In this manuscript,we...While machine learning(ML)in experimental research has demonstrated impressive predictive capabilities,extracting fungible knowledge representations from experimental data remains an elusive task.In this manuscript,we use ML to infer the underlying differential equation(DE)from experimental data of degrading organic-inorganic methylammonium lead iodide(MAPI)perovskite thin films under environmental stressors(elevated temperature,humidity,and light).Using a sparse regression algorithm,we find that the underlying DE governing MAPI degradation across a broad temperature range of 35 to 85℃is described minimally by a second-order polynomial.This DE corresponds to the Verhulst logistic function,which describes reaction kinetics analogous to self-propagating reactions.We examine the robustness of our conclusions to experimental variance and Gaussian noise and describe the experimental limits within which this methodology can be applied.Our study highlights the promise and challenges associated with ML-aided scientific discovery by demonstrating its application in experimental chemical and materials systems.展开更多
文摘The current problems facing literary criticism are not only the influence of the external environment,but also the understanding of the traditional Chinese culture from the perspective of“globalization”and“diversification”of literature.It is also a guide for related literary criticism.This paper first discusses the pluralism of literary criticism,gives an overview of literary criticism,analyzes the problems of literary criticism in Chinese literature in our country,and finally propoeses relevant suggestions for literary criticism under pluralism.
基金This work was supported by a TOTAL SA research grant funded through MITei(supporting the experimental XRD),the National Research Foundation(NRF),Singapore through the Singapore Massachusetts Institute of Technology(MIT)Alliance for Research and Technology’s Low Energy Electronic Systems research program(supporting the machine learning algorithm development),the Accelerated Materials Development for Manufacturing Program at A*STAR via the AME Programmatic Fund by the Agency for Science,Technology and Research under Grant No.A1898b0043(for ML algorithm error analysis)by the U.S.Department of Energy under the Photovoltaic Research and Development program under Award DE-EE0007535(for code framework development)This work made use of the CMSE at MIT,which is supported by NSF award DMR-0819762.
文摘X-ray diffraction(XRD)data acquisition and analysis is among the most time-consuming steps in the development cycle of novel thin-film materials.We propose a machine learning-enabled approach to predict crystallographic dimensionality and space group from a limited number of thin-film XRD patterns.We overcome the scarce data problem intrinsic to novel materials development by coupling a supervised machine learning approach with a model-agnostic,physics-informed data augmentation strategy using simulated data from the Inorganic Crystal Structure Database(ICSD)and experimental data.As a test case,115 thin-film metalhalides spanning three dimensionalities and seven space groups are synthesized and classified.After testing various algorithms,we develop and implement an all convolutional neural network,with cross-validated accuracies for dimensionality and space group classification of 93 and 89%,respectively.We propose average class activation maps,computed from a global average pooling layer,to allow high model interpretability by human experimentalists,elucidating the root causes of misclassification.Finally,we systematically evaluate the maximum XRD pattern step size(data acquisition rate)before loss of predictive accuracy occurs,and determine it to be 0.16°2θ,which enables an XRD pattern to be obtained and classified in 5.5 min or less.
基金Q.L.acknowledges generous funding from TOTAL S.A.research grant funded through MITei for supporting his research.A.E.G.,K.A.B.thank Google LLC,the Boston University Dean’s Catalyst Award,The Boston University Rafik B.Hariri Institute for Computing and Computational Science and Engineering,and NSF(CMMI-1661412)for support in this work and studies generating crossed barrel dataset.A.T.,Z.L.,S.S.,T.B.acknowledge support from DARPA under Contract No.HR001118C0036TOTAL S.A.research grant funded through MITei,US National Science Foundation grant CBET-1605547+2 种基金the Skoltech NGP program for research generating Perovskite dataset.Z.R.and T.B.are supported by the National Research Foundation,Prime Minister’s Office,Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)programthrough the Singapore Massachusetts Institute of Technology(MIT)Alliance for Research and Technology’s Low Energy Electronic Systems research program.J.D.,B.M.thank AFOSR Grant 19RHCOR089 for supporting their work in generating the AutoAM datasetD.B.,K.H.acknowledge funding from the Accelerated Materials Development for Manufacturing Program at A*STAR via the AME Programmatic Fund by the Agency for Science,Technology,and Research under Grant No.A1898b0043 and A*STAR Graduate Academy’s SINGA programme for producing P3HT/CNT datasetF.M.B.,S.K.acknowledge support from the Accelerated Materials Development for Manufacturing Program at A*STAR via the AME Programmatic Fund by the Agency for Science,Technology and Research under Grant No.A1898b0043.
文摘Bayesian optimization(BO)has been leveraged for guiding autonomous and high-throughput experiments in materials science.However,few have evaluated the efficiency of BO across a broad range of experimental materials domains.In this work,we quantify the performance of BO with a collection of surrogate model and acquisition function pairs across five diverse experimental materials systems.By defining acceleration and enhancement metrics for materials optimization objectives,we find that surrogate models such as Gaussian Process(GP)with anisotropic kernels and Random Forest(RF)have comparable performance in BO,and both outperform the commonly used GP with isotropic kernels.GP with anisotropic kernels has demonstrated the most robustness,yet RF is a close alternative and warrants more consideration because it is free from distribution assumptions,has smaller time complexity,and requires less effort in initial hyperparameter selection.We also raise awareness about the benefits of using GP with anisotropic kernels in future materials optimization campaigns.
基金This research is supported by the National Research Foundation,Prime Minister’s Office,Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)program and its Energy Innovation Research program EIRP-13(Award No.NRF2015EWT-EIRP003-004)(supporting GaAs device fabrication)by the National Research Foundation(NRF)Singapore through the Singapore Massachusetts Institute of Technology(MIT)Alliance for Research and Technology’s Low Energy Electronic Systems research program(supporting AE and physics-constrained Bayesian inference algorithm development)+1 种基金by the US Department of Energy Photovoltaic Research and Development Program under Award DE-EE0007535(supporting Bayesian optimization algorithm development),and by a TOTAL SA research grant funded through MITei(supporting ML algorithm framing and application)Q.L.acknowledges funding from the Accelerated Materials Development for Manufacturing Program at A*STAR via the AME Programmatic Fund by the Agency for Science,Technology and Research under Grant No.A1898b0043.
文摘Process optimization of photovoltaic devices is a time-intensive,trial-and-error endeavor,which lacks full transparency of the underlying physics and relies on user-imposed constraints that may or may not lead to a global optimum.Herein,we demonstrate that embedding physics domain knowledge into a Bayesian network enables an optimization approach for gallium arsenide(GaAs)solar cells that identifies the root cause(s)of underperformance with layer-by-layer resolution and reveals alternative optimal process windows beyond traditional black-box optimization.Our Bayesian network approach links a key GaAs process variable(growth temperature)to material descriptors(bulk and interface properties,e.g.,bulk lifetime,doping,and surface recombination)and device performance parameters(e.g.,cell efficiency).For this purpose,we combine a Bayesian inference framework with a neural network surrogate device-physics model that is 100×faster than numerical solvers.With the trained surrogate model and only a small number of experimental samples,our approach reduces significantly the time-consuming intervention and characterization required by the experimentalist.As a demonstration of our method,in only five metal organic chemical vapor depositions,we identify a superior growth temperature profile for the window,bulk,and back surface field layer of a GaAs solar cell,without any secondary measurements,and demonstrate a 6.5%relative AM1.5G efficiency improvement above traditional grid search methods.
基金This work was supported by Defense Advanced Research Projects Agency(DARPA)under contract no.HR001118C0036(R.N.,J.T.,A.T.)TotalEnergies SE research grant funded through MITeI Sustng Mbr 9/08(A.T.,S.S.,Z.L.)+2 种基金the U.S.Department of Energy(DOE)under Photovoltaic Research and Development(PVRD)program under Award no.DE-EE0007535(Z.L.)This work was partially supported by the U.S.Department of Energy’s Office of Energy Efficiency and Renewable Energy(EERE)under the Advanced Manufacturing Office(AMO)Award Number DE-EE0009096(R.N.)A.T.acknowledges the Alfred Kordelin Foundation.
文摘While machine learning(ML)in experimental research has demonstrated impressive predictive capabilities,extracting fungible knowledge representations from experimental data remains an elusive task.In this manuscript,we use ML to infer the underlying differential equation(DE)from experimental data of degrading organic-inorganic methylammonium lead iodide(MAPI)perovskite thin films under environmental stressors(elevated temperature,humidity,and light).Using a sparse regression algorithm,we find that the underlying DE governing MAPI degradation across a broad temperature range of 35 to 85℃is described minimally by a second-order polynomial.This DE corresponds to the Verhulst logistic function,which describes reaction kinetics analogous to self-propagating reactions.We examine the robustness of our conclusions to experimental variance and Gaussian noise and describe the experimental limits within which this methodology can be applied.Our study highlights the promise and challenges associated with ML-aided scientific discovery by demonstrating its application in experimental chemical and materials systems.