Studies have shown that vascular dysfunction is closely related to the pathogenesis of Alzheimer's disease.The middle temporal gyrus region of the brain is susceptible to pronounced impairment in Alzheimer's d...Studies have shown that vascular dysfunction is closely related to the pathogenesis of Alzheimer's disease.The middle temporal gyrus region of the brain is susceptible to pronounced impairment in Alzheimer's disease.Identification of the molecules involved in vascular aberrance of the middle temporal gyrus would support elucidation of the mechanisms underlying Alzheimer's disease and discove ry of novel targets for intervention.We carried out single-cell transcriptomic analysis of the middle temporal gyrus in the brains of patients with Alzheimer's disease and healthy controls,revealing obvious changes in vascular function.CellChat analysis of intercellular communication in the middle temporal gyrus showed that the number of cell interactions in this region was decreased in Alzheimer's disease patients,with altered intercellular communication of endothelial cells and pericytes being the most prominent.Differentially expressed genes were also identified.Using the CellChat results,AUCell evaluation of the pathway activity of specific cells showed that the obvious changes in vascular function in the middle temporal gyrus in Alzheimer's disease were directly related to changes in the vascular endothelial growth factor(VEGF)A-VEGF receptor(VEGFR)2 pathway.AUCell analysis identified subtypes of endothelial cells and pericytes directly related to VEGFA-VEGFR2 pathway activity.Two subtypes of middle temporal gyrus cells showed significant alteration in AD:endothelial cells with high expression of Erb-B2 receptor tyrosine kinase 4(ERBB4^(high))and pericytes with high expression of angiopoietin-like 4(ANGPTL4^(high)).Finally,combining bulk RNA sequencing data and two machine learning algorithms(least absolute shrinkage and selection operator and random forest),four characteristic Alzheimer's disease feature genes were identified:somatostatin(SST),protein tyrosine phosphatase non-receptor type 3(PTPN3),glutinase(GL3),and tropomyosin 3(PTM3).These genes were downregulated in the middle temporal gyrus of patients with Alzheimer's disease and may be used to target the VEGF pathway.Alzheimer's disease mouse models demonstrated consistent altered expression of these genes in the middle temporal gyrus.In conclusion,this study detected changes in intercellular communication between endothelial cells and pericytes in the middle temporal gyrus and identified four novel feature genes related to middle temporal gyrus and vascular functioning in patients with Alzheimer's disease.These findings contribute to a deeper understanding of the molecular mechanisms underlying Alzheimer's disease and present novel treatment targets.展开更多
Although biomass-derived carbon(biochar)has been widely used in the energy field,the relation between the carbonization condition and the physical/chemical property of the product remains elusive.Here,we revealed the ...Although biomass-derived carbon(biochar)has been widely used in the energy field,the relation between the carbonization condition and the physical/chemical property of the product remains elusive.Here,we revealed the carbonization condition's effect on the morphology,surface property,and electrochemical performance of the obtained carbon.An open slit pore structure with shower-puff-like nanoparticles can be obtained by finely tuning the carbonization temperature,and its unique pore structure and surface properties enable the Li–O_(2) battery with cycling longevity(221 cycles with 99.8%Coulombic efficiency at 0.2 mA cm^(−2) and controlled discharge–charge depths of 500 mAh g^(−1))and high capacity(16,334 mAh g^(−1) at 0.02 mA cm^(−2)).This work provides a greater understanding of the mechanism of the biochar carbonization procedure under various pyrolysis conditions,paving the way for future study of energy storage devices.展开更多
Intersections are quite important and complex traffic scenarios,where the future motion of surrounding vehicles is an indispensable reference factor for the decision-making or path planning of autonomous vehicles.Cons...Intersections are quite important and complex traffic scenarios,where the future motion of surrounding vehicles is an indispensable reference factor for the decision-making or path planning of autonomous vehicles.Considering that the motion trajectory of a vehicle at an intersection partly obeys the statistical law of historical data once its driving intention is determined,this paper proposes a long short-term memory based(LSTM-based)framework that combines intention prediction and trajectory prediction together.First,we build an intersection prior trajectories model(IPTM)by clustering and statistically analyzing a large number of prior traffic flow trajectories.The prior trajectories model with fitted probabilistic density is used to approximate the distribution of the predicted trajectory,and also serves as a reference for credibility evaluation.Second,we conduct the intention prediction through another LSTM model and regard it as a crucial cue for a trajectory forecast at the early stage.Furthermore,the predicted intention is also a key that is associated with the prior trajectories model.The proposed framework is validated on two publically released datasets,next generation simulation(NGSIM)and INTERACTION.Compared with other prediction methods,our framework is able to sample a trajectory from the estimated distribution,with its accuracy improved by about 20%.Finally,the credibility evaluation,which is based on the prior trajectories model,makes the framework more practical in the real-world applications.展开更多
Designing high-performance nanostructured electrode materials is the current core of electrochemical energy storage devices.Multi-scaled nanomaterials have triggered considerable interest because they effectively comb...Designing high-performance nanostructured electrode materials is the current core of electrochemical energy storage devices.Multi-scaled nanomaterials have triggered considerable interest because they effectively combine a library of advantages of each component on different scales for energy storage.However,serious aggregation,structural degradation,and even poor stability of nanomaterials are well-known issues during electrochemically driven volume expansion/contraction processes.The confinement strategy provides a new route to construct controllable internal void spaces to avoid the intrinsic volume effects of nanomaterials during the reaction or charge/discharge process.Herein,we discuss the confinement strategies and methods for energy storage-related electrode materials with a one-dimensional channel,two-dimensional interlayer,and three-dimensional space as reaction environments.For each confinement environment,the correlation between the confinement condition/structure and the behavioral characteristics of energy storage devices in the scope of metal-ion batteries(e.g.,Li-ion,Na-ion,K-ion,and Mg-ion batteries),Li-S batteries(LSBs),Zn-air batteries(ZIBs),and supercapacitors.Finally,we discussed the challenges and perspectives on future nanomaterial confinement strategies for electrochemical energy storage devices.展开更多
The rational design of large-area exposure,nonagglomeration,and longrange dispersion of metal nanoparticles(NPs)in the catalysts is critical for the development of energy storage and conversion systems.Little attentio...The rational design of large-area exposure,nonagglomeration,and longrange dispersion of metal nanoparticles(NPs)in the catalysts is critical for the development of energy storage and conversion systems.Little attention has been focused on modulating and developing catalyst interface contact engineering between a carbon substrate and dispersed metal.Here,a highly dispersed ultrafine ruthenium(Ru)NP strategy by double spatial confinement is proposed,that is,incorporating directed growth of metal–organic framework crystals into a bacterial cellulose templating substrate to integrate their respective merits as an excellent electrocatalytic cathode catalyst for a quasi-solid-state Li–O_(2) battery.The porous carbon matrix with highly dispersed ultrafine Ru NPs is well designed and used as cathode catalysts in a Li–O_(2) battery,demonstrating a high discharge areal capacity of 6.82 mAh cm^(–2) at 0.02 mA cm^(–2),a high-rate capability of 4.93 mAh cm^(–2) at 0.2 mA cm^(–2),and stable discharge/charge cycling for up to 500 cycles(2000 h)with low overpotentials of~1.4 V.This fundamental understanding of the structure–performance relationship demonstrates a new and promising approach to optimize highly efficient cathode catalysts for solid-state Li–O_(2) batteries.展开更多
In the present paper, we establish direct and converse theorems for weight-ed Bernstein-Durrmeyer operators under weighted L^p-norm with Jacobi weight w（x）=x^a（1-x）β.All the results involved have no restriction a...In the present paper, we establish direct and converse theorems for weight-ed Bernstein-Durrmeyer operators under weighted L^p-norm with Jacobi weight w（x）=x^a（1-x）β.All the results involved have no restriction a,β〈1-1/p,which indicates that the weighted Bemstein-Durrmeyer operators have some better approxi- mation properties than the usual Bernstein-Durrmeyer operators.展开更多
China-Africa corporate advertising is emerging as an example of the corporate advertising genre in response to the specific rhetorical context of China-Africa win-win cooperation.Drawing on Bhatia’s Critical Genre An...China-Africa corporate advertising is emerging as an example of the corporate advertising genre in response to the specific rhetorical context of China-Africa win-win cooperation.Drawing on Bhatia’s Critical Genre Analysis(2017),this study explores the text-internal and text-external generic features of China-Africa corporate advertising by analyzing 50 collected samples.The analysis of text-internal prominence shows that China-Africa corporate advertising is unique in its frequent use of win-win-oriented and sector-dependent technical lexicons to indicate the promotional intent.It is also found that move structures vary across different sub-types of ChinaAfrica corporate advertising.Text-externally,the findings reveal a mixture of different discourses within the discursive space of China-Africa corporate advertising.In addition,the results suggest that Chinese companies invest more rhetorical efforts in enhancing the China-Africa community than African counterparts who tend to perceive China-Africa cooperation as the main avenue to attract worldwide partnerships.The findings have some practical implications for discourse construction in the Belt and Road Initiative context and shed light on the evolving nature of advertising discourse,particularly in the China-Africa win-win business context.展开更多
Breast cancer has become a common tumor worldwide which seriously endangers people＇s health. Earlydiagnosis and treatment are particularly urgent in order to reduce the onset risk, mortality, and prolongthe five-year...Breast cancer has become a common tumor worldwide which seriously endangers people＇s health. Earlydiagnosis and treatment are particularly urgent in order to reduce the onset risk, mortality, and prolongthe five-year survival rate. Therefore, we need a kind of diagnosis and treatment technology with highspecificity, sensitivity and selectivity. In recent years, because of its unique properties in biologicalapplications, fluorescence imaging has become an attractive research subject. Fluorescence imagingoffers innovative ideas of targetable recognition of breast cancer cells, breast cancer imaging in vivoanimal models, anticancer drugs delivery for guiding the mammary surgery via a noninvasive way withhigh sensitively and specifically. In this review, we summarized the recent advances of fluorescent probesfor breast cancer imaging, which were classified according to different biomarkers the probes recognized.Moreover, we discussed the strengths, built-in problems as well as the challenges about the fluorescentprobe as a unique potential method for the better application in breast cancer diagnosis and treatment.~ 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.展开更多
The navigation problem of the lifting reentry vehicles has attracted much research interest in the past decade. This paper researches the navigation in the blackout zone during the reentry phase of the aircraft, when ...The navigation problem of the lifting reentry vehicles has attracted much research interest in the past decade. This paper researches the navigation in the blackout zone during the reentry phase of the aircraft, when the communication signals are attenuated and even interrupted by the blackout zone. However, when calculating altitude, a pure classic inertial navigation algorithm appears imprecise and divergent. In order to obtain a more precise aircraft altitude, this paper applies an integrated navigation method based on inertial navigation algorithms, which uses drag derived altitude to aid the inertial navigation during the blackout zone. This method can overcome the shortcomings of the inertial navigation system and improve the navigation accuracy. To further improve the navigation accuracy, the applicable condition and the main error factors, such as the atmospheric coefficient error and drag coefficient error are analyzed in detail. Then the damping circuit design of the navigation control system and the damping coefficients determination is introduced. The feasibility of the method is verified by the typical reentry trajectory simulation, and the influence of the iterative times on the accuracy is analyzed. Simulation results show that iterative three times achieves the best effect.展开更多
A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing ...A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing molecular-scale grids(diameter~2.0 nm)allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process.A subsequent activation step produces activated porous carbons(APCs)with tailored pore structures,which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites.Coupled with large specific surface area and abundant heteroatoms,the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor.The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg,which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles.Moreover,this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.展开更多
Because of abundant redox activity,broad tunability,and specific atomic structure,polyoxometalates(POMs or POM)clusters have attracted burgeoning interests in electrochemical especially energy stor-age fields.Neverthe...Because of abundant redox activity,broad tunability,and specific atomic structure,polyoxometalates(POMs or POM)clusters have attracted burgeoning interests in electrochemical especially energy stor-age fields.Nevertheless,due to the high solubility and fully oxidized state,they often suffer from elec-trically insulation as well as chemical and electrochemical instability.Traditional noncovalent loading or covalent grafting of POMs on conductive substrates have been successfully performed to overcome this problem.However,severe shedding or agglomeration of POMs arising from weak interactions with substrates or excessive entrapment or weak destruction in conductive supports cause significantly re-duced availability and stability.To this end,precise confinement of POMs into conductive supports has been tried to improve their dispersibility and stability.Herein,recent progress of PoMs from surface loading to precise confinement in the electrochemistry energy storage field is reviewed.Firstly,we il-lustrate the typical non-confinement methods(viz.covalent and non-covalent)for supported POMs in energy storage applications.Secondly,different strategies for precise confinement of PoMs in organic and inorganic materials for related applications are also discussed.Finally,future research directions and opportunities for confined POMs,and derived ultrafine nanostructures are also proposed.This re-view seeks to point out future research directions of supported PoMs in the electrochemistry-related fields.展开更多
Aggregation of polyoxometalates(POM)is largely responsible for the reduced performance of POM-based energy-storage systems.To address this challenge,here,the precise confinement of single Keggin-type POM molecule in a...Aggregation of polyoxometalates(POM)is largely responsible for the reduced performance of POM-based energy-storage systems.To address this challenge,here,the precise confinement of single Keggin-type POM molecule in a porous carbon(PC)of unimodal super-micropore(micro-PC)is realized.Such precise single-molecule confinement enables sufficient activity center exposure and maximum electron-transfer from micro-PC to POM,which well stabilizes the electron-accepting molecules and thoroughly activates its inherent multi-electron redox-activity.In particular,the redox-activities and electron-accepting properties of the confined POM molecule are revealed to be super-micropore pore size-dependent by experiment and spectroscopy as well as theoretical calculation.Meanwhile,the molecularly dispersed POM molecules confined steadily in the“cage”of micro-PC exhibit unprecedented large-negative-potential stability and multiple-peak redox-activity at an ultra-low loading of~11.4 wt%.As a result,the fabricated solid-state supercapacitor achieves a remarkable areal capacitance,ultrahigh energy and power density of 443 mF cm^(-2),0.12 mWh cm^(-2)and 21.1 mW cm^(-2),respectively.This work establishes a novel strategy for the precise confinement of single POM molecule,providing a versatile approach to inducing the intrinsic activity of POMs for advanced energy-storage systems.展开更多
Magnesium oxide was found to have high-phosphate-affinity as an effective component to enhance the phosphate removal ability of common adsorbent materials.However,the currently prepared MgO-based hybrid adsorbents by ...Magnesium oxide was found to have high-phosphate-affinity as an effective component to enhance the phosphate removal ability of common adsorbent materials.However,the currently prepared MgO-based hybrid adsorbents by conventional methods still suffer from the limited low loading of MgO and inferior removal performances,much far away from practical application.In this study,an ingenious carbon coated MgO nanocomposite is designed by directly burning magnesium in CO_(2),a well-known textbook reaction.X-ray diffraction analysis,scanning electron microscope and aberration-corrected high-resolution transmission electron microscope demonstrate the sample is well prepared.Consequently,the high content of nanosized MgO combined with defect-rich carbon layer brings unprecedented phosphate removal capacity of 1135.0 mg/g,removal rate of 99% and benign compatibility with coexisting anions and solution pH.Furthermore,the removal mechanism is also investigated in detail by characterizing the sample before and after adsorption.展开更多
Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence...Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence remain elusive.In this study,we characterized one up-regulated gene PhOBF1,belonging to the basic leucine zipper transcription factor family,in senescing petals of petunia(Petunia hybrida).Exogenous treatments with ethylene and GA3 provoked a dramatic increase in PhOBF1 transcripts.Compared with wild-type plants,PhOBF1-RNAi transgenic petunia plants exhibited shortened f lower longevity,while overexpression of PhOBF1 resulted in delayed flower senescence.Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants.Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways,as well as accumulation levels of bioactive GAs GA1 and GA3.Application of GA3 restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines,and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1,PhACS1,and PhACS2.Moreover,PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif.Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence.Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated f lower senescence by modulating the GA production.展开更多
Della Vecchia et al. （see [2]） introduced a kind of modified Bernstein operators which can be used to approximate functions with singularities at endpoints on [0,1]. In the present paper, we obtain a kind of pointwi...Della Vecchia et al. （see [2]） introduced a kind of modified Bernstein operators which can be used to approximate functions with singularities at endpoints on [0,1]. In the present paper, we obtain a kind of pointwise Stechkin-type inequalities for weighted approximation by the modified Bemsetin operators.展开更多
The transmembrane protein HER2 is overexpressed in approximately 30% of breast cancer patients.HER2-positive breast cancers tend to spread more aggressively, which result in increased mortality inwomen. Nowadays, the ...The transmembrane protein HER2 is overexpressed in approximately 30% of breast cancer patients.HER2-positive breast cancers tend to spread more aggressively, which result in increased mortality inwomen. Nowadays, the real-time monitoring of HER2 status is important in clinical diagnosis andtreatment for HER2-positive patients. Although IHC and FISH assay are standard methods to evaluate thetissue HER2 status, both approaches which required high quality tissue samples and are not suitable formonitoring the status of HER2 in real time. Since extracellular domain （ECD） of the HER2 receptor can beshed into the circulation, the serum test of HER2 ECD has been developed as an additional approach toprobe HER2 overexpression. The serum test will be able to monitor the dynamic changes of HER2 status.In this paper, we detected serum HER2 ECD using CyS-labeled HB5 aptamer as a result of its specificbinding ability to HER2 ECD. This aptamer-based fluorescent probe is easily synthesized and modifiedand as sensitive as anti-HER2 antibodies. We believe that Cy5-HB5 may have application potentials inserum HER2 test for clinical utility of breast cancer, such as recurrence and metastases.展开更多
Intrinsic ferroelectric materials play a critical role in the development of high-density integrated device. Despite some two-dimensional (2D) ferroelectrics have been reported, the research on one-dimensional (1D) in...Intrinsic ferroelectric materials play a critical role in the development of high-density integrated device. Despite some two-dimensional (2D) ferroelectrics have been reported, the research on one-dimensional (1D) intrinsic ferroelectric materials remains relatively scare since 1D atomic structures limit their van der Waals (vdW) epitaxy growth. Here, we report the synthesis of 1D intrinsic vdW ferroelectric SbSI nanowires via a confined-space chemical vapor deposition. By precisely controlling the partial vapor pressure of I2 and reaction temperature, we can effectively manipulate kinetics and thermodynamics processes, and thus obtain high quality of SbSI nanowires, which is determined by Raman spectroscopy and high-resolution scanning transmission electron microscopy characterizations. The ferroelectricity in SbSI is confirmed by piezo-response force microscopy measurements and the ferroelectric transition temperature of 300 K is demonstrated by second harmonic generation. Moreover, the in-plane polarization switching can be maintained in the thin SbSI nanowires with a thickness of 20 nm. Our prepared 1D vdW ferroelectric SbSI nanowires not only enrich the vdW ferroelectric systems, but also open a new possibility for high-power energy storage nanodevices.展开更多
基金supported by the Natural Science Foundation of Shanxi Province,No.20210302123299The Belt and Road Program of Shanxi Province,No.110000261420228002(both to CZ)。
文摘Studies have shown that vascular dysfunction is closely related to the pathogenesis of Alzheimer's disease.The middle temporal gyrus region of the brain is susceptible to pronounced impairment in Alzheimer's disease.Identification of the molecules involved in vascular aberrance of the middle temporal gyrus would support elucidation of the mechanisms underlying Alzheimer's disease and discove ry of novel targets for intervention.We carried out single-cell transcriptomic analysis of the middle temporal gyrus in the brains of patients with Alzheimer's disease and healthy controls,revealing obvious changes in vascular function.CellChat analysis of intercellular communication in the middle temporal gyrus showed that the number of cell interactions in this region was decreased in Alzheimer's disease patients,with altered intercellular communication of endothelial cells and pericytes being the most prominent.Differentially expressed genes were also identified.Using the CellChat results,AUCell evaluation of the pathway activity of specific cells showed that the obvious changes in vascular function in the middle temporal gyrus in Alzheimer's disease were directly related to changes in the vascular endothelial growth factor(VEGF)A-VEGF receptor(VEGFR)2 pathway.AUCell analysis identified subtypes of endothelial cells and pericytes directly related to VEGFA-VEGFR2 pathway activity.Two subtypes of middle temporal gyrus cells showed significant alteration in AD:endothelial cells with high expression of Erb-B2 receptor tyrosine kinase 4(ERBB4^(high))and pericytes with high expression of angiopoietin-like 4(ANGPTL4^(high)).Finally,combining bulk RNA sequencing data and two machine learning algorithms(least absolute shrinkage and selection operator and random forest),four characteristic Alzheimer's disease feature genes were identified:somatostatin(SST),protein tyrosine phosphatase non-receptor type 3(PTPN3),glutinase(GL3),and tropomyosin 3(PTM3).These genes were downregulated in the middle temporal gyrus of patients with Alzheimer's disease and may be used to target the VEGF pathway.Alzheimer's disease mouse models demonstrated consistent altered expression of these genes in the middle temporal gyrus.In conclusion,this study detected changes in intercellular communication between endothelial cells and pericytes in the middle temporal gyrus and identified four novel feature genes related to middle temporal gyrus and vascular functioning in patients with Alzheimer's disease.These findings contribute to a deeper understanding of the molecular mechanisms underlying Alzheimer's disease and present novel treatment targets.
基金supported by the National Natural Science Foundation of China(NSFC No.22179005)the BIT Research and Innovation Promoting Project(Grant No.2022YCXY008)supported by Cunzhong Zhang at the Beijing Institute of Technology.
文摘Although biomass-derived carbon(biochar)has been widely used in the energy field,the relation between the carbonization condition and the physical/chemical property of the product remains elusive.Here,we revealed the carbonization condition's effect on the morphology,surface property,and electrochemical performance of the obtained carbon.An open slit pore structure with shower-puff-like nanoparticles can be obtained by finely tuning the carbonization temperature,and its unique pore structure and surface properties enable the Li–O_(2) battery with cycling longevity(221 cycles with 99.8%Coulombic efficiency at 0.2 mA cm^(−2) and controlled discharge–charge depths of 500 mAh g^(−1))and high capacity(16,334 mAh g^(−1) at 0.02 mA cm^(−2)).This work provides a greater understanding of the mechanism of the biochar carbonization procedure under various pyrolysis conditions,paving the way for future study of energy storage devices.
基金partly supported by the National Natural Science Foundation of China(61903034,U1913203,61973034,91120003)the Program for Changjiang Scholars and Innovative Research Team in University(IRT-16R06,T2014224)+1 种基金China Postdoctoral Science Foundation funded project(2019TQ0035)Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘Intersections are quite important and complex traffic scenarios,where the future motion of surrounding vehicles is an indispensable reference factor for the decision-making or path planning of autonomous vehicles.Considering that the motion trajectory of a vehicle at an intersection partly obeys the statistical law of historical data once its driving intention is determined,this paper proposes a long short-term memory based(LSTM-based)framework that combines intention prediction and trajectory prediction together.First,we build an intersection prior trajectories model(IPTM)by clustering and statistically analyzing a large number of prior traffic flow trajectories.The prior trajectories model with fitted probabilistic density is used to approximate the distribution of the predicted trajectory,and also serves as a reference for credibility evaluation.Second,we conduct the intention prediction through another LSTM model and regard it as a crucial cue for a trajectory forecast at the early stage.Furthermore,the predicted intention is also a key that is associated with the prior trajectories model.The proposed framework is validated on two publically released datasets,next generation simulation(NGSIM)and INTERACTION.Compared with other prediction methods,our framework is able to sample a trajectory from the estimated distribution,with its accuracy improved by about 20%.Finally,the credibility evaluation,which is based on the prior trajectories model,makes the framework more practical in the real-world applications.
基金funding from the National Natural Science Foundation of China(Nos.51902222,51972221).
文摘Designing high-performance nanostructured electrode materials is the current core of electrochemical energy storage devices.Multi-scaled nanomaterials have triggered considerable interest because they effectively combine a library of advantages of each component on different scales for energy storage.However,serious aggregation,structural degradation,and even poor stability of nanomaterials are well-known issues during electrochemically driven volume expansion/contraction processes.The confinement strategy provides a new route to construct controllable internal void spaces to avoid the intrinsic volume effects of nanomaterials during the reaction or charge/discharge process.Herein,we discuss the confinement strategies and methods for energy storage-related electrode materials with a one-dimensional channel,two-dimensional interlayer,and three-dimensional space as reaction environments.For each confinement environment,the correlation between the confinement condition/structure and the behavioral characteristics of energy storage devices in the scope of metal-ion batteries(e.g.,Li-ion,Na-ion,K-ion,and Mg-ion batteries),Li-S batteries(LSBs),Zn-air batteries(ZIBs),and supercapacitors.Finally,we discussed the challenges and perspectives on future nanomaterial confinement strategies for electrochemical energy storage devices.
基金National Natural Science Foundation of China,Grant/Award Number:22179005National Key Research and Development Program of China,Grant/Award Number:2018YFC1900102。
文摘The rational design of large-area exposure,nonagglomeration,and longrange dispersion of metal nanoparticles(NPs)in the catalysts is critical for the development of energy storage and conversion systems.Little attention has been focused on modulating and developing catalyst interface contact engineering between a carbon substrate and dispersed metal.Here,a highly dispersed ultrafine ruthenium(Ru)NP strategy by double spatial confinement is proposed,that is,incorporating directed growth of metal–organic framework crystals into a bacterial cellulose templating substrate to integrate their respective merits as an excellent electrocatalytic cathode catalyst for a quasi-solid-state Li–O_(2) battery.The porous carbon matrix with highly dispersed ultrafine Ru NPs is well designed and used as cathode catalysts in a Li–O_(2) battery,demonstrating a high discharge areal capacity of 6.82 mAh cm^(–2) at 0.02 mA cm^(–2),a high-rate capability of 4.93 mAh cm^(–2) at 0.2 mA cm^(–2),and stable discharge/charge cycling for up to 500 cycles(2000 h)with low overpotentials of~1.4 V.This fundamental understanding of the structure–performance relationship demonstrates a new and promising approach to optimize highly efficient cathode catalysts for solid-state Li–O_(2) batteries.
文摘In the present paper, we establish direct and converse theorems for weight-ed Bernstein-Durrmeyer operators under weighted L^p-norm with Jacobi weight w（x）=x^a（1-x）β.All the results involved have no restriction a,β〈1-1/p,which indicates that the weighted Bemstein-Durrmeyer operators have some better approxi- mation properties than the usual Bernstein-Durrmeyer operators.
基金the research output of the National Social Sciences research project entitled“A Genre-based Study of the Dynamic Intertextual and Interdiscursive System in Chinese and Foreign Professional Discourse”(NO.17BYY033)。
文摘China-Africa corporate advertising is emerging as an example of the corporate advertising genre in response to the specific rhetorical context of China-Africa win-win cooperation.Drawing on Bhatia’s Critical Genre Analysis(2017),this study explores the text-internal and text-external generic features of China-Africa corporate advertising by analyzing 50 collected samples.The analysis of text-internal prominence shows that China-Africa corporate advertising is unique in its frequent use of win-win-oriented and sector-dependent technical lexicons to indicate the promotional intent.It is also found that move structures vary across different sub-types of ChinaAfrica corporate advertising.Text-externally,the findings reveal a mixture of different discourses within the discursive space of China-Africa corporate advertising.In addition,the results suggest that Chinese companies invest more rhetorical efforts in enhancing the China-Africa community than African counterparts who tend to perceive China-Africa cooperation as the main avenue to attract worldwide partnerships.The findings have some practical implications for discourse construction in the Belt and Road Initiative context and shed light on the evolving nature of advertising discourse,particularly in the China-Africa win-win business context.
基金financial supports from the National Natural Science Foundation of China(Nos.31370391,81772812,21422606,21402191)Dalian Cultivation Fund for Distinguished Young Scholars(Nos.2014J11JH130 and 2015J12JH205)The Foundation of Dalian Science Department(No.2015E12SF149)
文摘Breast cancer has become a common tumor worldwide which seriously endangers people＇s health. Earlydiagnosis and treatment are particularly urgent in order to reduce the onset risk, mortality, and prolongthe five-year survival rate. Therefore, we need a kind of diagnosis and treatment technology with highspecificity, sensitivity and selectivity. In recent years, because of its unique properties in biologicalapplications, fluorescence imaging has become an attractive research subject. Fluorescence imagingoffers innovative ideas of targetable recognition of breast cancer cells, breast cancer imaging in vivoanimal models, anticancer drugs delivery for guiding the mammary surgery via a noninvasive way withhigh sensitively and specifically. In this review, we summarized the recent advances of fluorescent probesfor breast cancer imaging, which were classified according to different biomarkers the probes recognized.Moreover, we discussed the strengths, built-in problems as well as the challenges about the fluorescentprobe as a unique potential method for the better application in breast cancer diagnosis and treatment.~ 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.
基金supported by the National Natural Science Foundation of China (No.61573059)
文摘The navigation problem of the lifting reentry vehicles has attracted much research interest in the past decade. This paper researches the navigation in the blackout zone during the reentry phase of the aircraft, when the communication signals are attenuated and even interrupted by the blackout zone. However, when calculating altitude, a pure classic inertial navigation algorithm appears imprecise and divergent. In order to obtain a more precise aircraft altitude, this paper applies an integrated navigation method based on inertial navigation algorithms, which uses drag derived altitude to aid the inertial navigation during the blackout zone. This method can overcome the shortcomings of the inertial navigation system and improve the navigation accuracy. To further improve the navigation accuracy, the applicable condition and the main error factors, such as the atmospheric coefficient error and drag coefficient error are analyzed in detail. Then the damping circuit design of the navigation control system and the damping coefficients determination is introduced. The feasibility of the method is verified by the typical reentry trajectory simulation, and the influence of the iterative times on the accuracy is analyzed. Simulation results show that iterative three times achieves the best effect.
基金financial support from National Natural Science Foundation of China(Nos.51902222,51603142,U1610255)Key Laboratory of Yarn Materials Forming and Composite Processing Technology,Zhejiang Province(No.MTC2019-03)+2 种基金Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(Nos.2019L0164 and 2019L0255)the Shanxi Provincial Key Innovative Research Team in Science and Technology(Nos.2015013002-10 and 201605D131045-10)Key R&D Program of Shanxi Province(International Cooperation,No.201903D421077)。
文摘A template-free carbonization-activation route is developed to fabricate sub-nanopore-containing porous carbon by using a novel polypyrrole(PPy)hydrogel as a precursor.This design of PPy hydrogel precursor containing molecular-scale grids(diameter~2.0 nm)allows for homogeneous N,O-codoping into the porous carbon scaffold during the pyrolysis process.A subsequent activation step produces activated porous carbons(APCs)with tailored pore structures,which renders the APCs abundant subnanopores on their surface to increase the specific capacitance as extra capacitance sites.Coupled with large specific surface area and abundant heteroatoms,the optimized APC4/1 displays excellent specific capacitance of 379 F/g for liquid-state supercapacitor and 230 F/g for solid-state supercapacitor.The solid-state supercapacitor shows a high energy density of 22.99 Wh/kg at power density of 420 W/kg,which is higher than most reported porous carbon materials and satisfy the urgent requirements of elementary power source for electric vehicles.Moreover,this method can be easily modified to fabricate sub-nanopore-containing porous carbons with preferred structures and compositions for many applications.
基金National Natural Science Foundation of China(Nos.51902222 and 62174013)The Central Government Guides Local Funds for Science and Technology Development(No.YDZJSX2022A021)+1 种基金National Natural Science Foundation of China(No.52201019)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(STIP,No.2022L036).
文摘Because of abundant redox activity,broad tunability,and specific atomic structure,polyoxometalates(POMs or POM)clusters have attracted burgeoning interests in electrochemical especially energy stor-age fields.Nevertheless,due to the high solubility and fully oxidized state,they often suffer from elec-trically insulation as well as chemical and electrochemical instability.Traditional noncovalent loading or covalent grafting of POMs on conductive substrates have been successfully performed to overcome this problem.However,severe shedding or agglomeration of POMs arising from weak interactions with substrates or excessive entrapment or weak destruction in conductive supports cause significantly re-duced availability and stability.To this end,precise confinement of POMs into conductive supports has been tried to improve their dispersibility and stability.Herein,recent progress of PoMs from surface loading to precise confinement in the electrochemistry energy storage field is reviewed.Firstly,we il-lustrate the typical non-confinement methods(viz.covalent and non-covalent)for supported POMs in energy storage applications.Secondly,different strategies for precise confinement of PoMs in organic and inorganic materials for related applications are also discussed.Finally,future research directions and opportunities for confined POMs,and derived ultrafine nanostructures are also proposed.This re-view seeks to point out future research directions of supported PoMs in the electrochemistry-related fields.
基金the National Natural Science Foundation of China(No.51902222,5197222 and 62174013)
文摘Aggregation of polyoxometalates(POM)is largely responsible for the reduced performance of POM-based energy-storage systems.To address this challenge,here,the precise confinement of single Keggin-type POM molecule in a porous carbon(PC)of unimodal super-micropore(micro-PC)is realized.Such precise single-molecule confinement enables sufficient activity center exposure and maximum electron-transfer from micro-PC to POM,which well stabilizes the electron-accepting molecules and thoroughly activates its inherent multi-electron redox-activity.In particular,the redox-activities and electron-accepting properties of the confined POM molecule are revealed to be super-micropore pore size-dependent by experiment and spectroscopy as well as theoretical calculation.Meanwhile,the molecularly dispersed POM molecules confined steadily in the“cage”of micro-PC exhibit unprecedented large-negative-potential stability and multiple-peak redox-activity at an ultra-low loading of~11.4 wt%.As a result,the fabricated solid-state supercapacitor achieves a remarkable areal capacitance,ultrahigh energy and power density of 443 mF cm^(-2),0.12 mWh cm^(-2)and 21.1 mW cm^(-2),respectively.This work establishes a novel strategy for the precise confinement of single POM molecule,providing a versatile approach to inducing the intrinsic activity of POMs for advanced energy-storage systems.
基金This study was supported by the National Key R&D Program of China through grant 2018YFC1900102A portion of this work was conducted at Argonne National Laboratory.Argonne National Laboratory is operated for DOE Office of Science by UChicago Argonne,LLC,under contract number DE-AC02-06CH11357This study was performed,in part,at the Center for Nanoscale Materials,a US Department of Energy Office of Science User Facility,and supported by the US Department of Energy,Office of Science,under Contract No.DE-AC02-06CH11357.
文摘Magnesium oxide was found to have high-phosphate-affinity as an effective component to enhance the phosphate removal ability of common adsorbent materials.However,the currently prepared MgO-based hybrid adsorbents by conventional methods still suffer from the limited low loading of MgO and inferior removal performances,much far away from practical application.In this study,an ingenious carbon coated MgO nanocomposite is designed by directly burning magnesium in CO_(2),a well-known textbook reaction.X-ray diffraction analysis,scanning electron microscope and aberration-corrected high-resolution transmission electron microscope demonstrate the sample is well prepared.Consequently,the high content of nanosized MgO combined with defect-rich carbon layer brings unprecedented phosphate removal capacity of 1135.0 mg/g,removal rate of 99% and benign compatibility with coexisting anions and solution pH.Furthermore,the removal mechanism is also investigated in detail by characterizing the sample before and after adsorption.
基金funded by the National Natural Science Foundation of China(Grant no.32271953 and 31801895)Postdoctoral Special Funding Project of China(Grant no.2019T120958)the Basic Scientific Research Expense of Northwest A&F University(Grant no.Z1090322159).
文摘Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins(GAs)in plants.However,the detailed mechanisms for the antagonism of these hormones during f lower senescence remain elusive.In this study,we characterized one up-regulated gene PhOBF1,belonging to the basic leucine zipper transcription factor family,in senescing petals of petunia(Petunia hybrida).Exogenous treatments with ethylene and GA3 provoked a dramatic increase in PhOBF1 transcripts.Compared with wild-type plants,PhOBF1-RNAi transgenic petunia plants exhibited shortened f lower longevity,while overexpression of PhOBF1 resulted in delayed flower senescence.Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants.Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways,as well as accumulation levels of bioactive GAs GA1 and GA3.Application of GA3 restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines,and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1,PhACS1,and PhACS2.Moreover,PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif.Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence.Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated f lower senescence by modulating the GA production.
文摘Della Vecchia et al. （see [2]） introduced a kind of modified Bernstein operators which can be used to approximate functions with singularities at endpoints on [0,1]. In the present paper, we obtain a kind of pointwise Stechkin-type inequalities for weighted approximation by the modified Bemsetin operators.
基金financially supported by the National Natural Science Foundation of China(Nos.81772812,21422606,21402191,and 21502189)Dalian Cultivation Fund for Distinguished Young Scholars(Nos.2014J11JH130 and 2015J12JH205)the Foundation of Dalian Science Department(No.2015E12SF149)
文摘The transmembrane protein HER2 is overexpressed in approximately 30% of breast cancer patients.HER2-positive breast cancers tend to spread more aggressively, which result in increased mortality inwomen. Nowadays, the real-time monitoring of HER2 status is important in clinical diagnosis andtreatment for HER2-positive patients. Although IHC and FISH assay are standard methods to evaluate thetissue HER2 status, both approaches which required high quality tissue samples and are not suitable formonitoring the status of HER2 in real time. Since extracellular domain （ECD） of the HER2 receptor can beshed into the circulation, the serum test of HER2 ECD has been developed as an additional approach toprobe HER2 overexpression. The serum test will be able to monitor the dynamic changes of HER2 status.In this paper, we detected serum HER2 ECD using CyS-labeled HB5 aptamer as a result of its specificbinding ability to HER2 ECD. This aptamer-based fluorescent probe is easily synthesized and modifiedand as sensitive as anti-HER2 antibodies. We believe that Cy5-HB5 may have application potentials inserum HER2 test for clinical utility of breast cancer, such as recurrence and metastases.
基金supported by the National Key R&D Program of China(Nos.2022YFA1203901 and 202221855043)the National Natural Science Foundation of China(Nos.62174013,92265111,and 12104050)+2 种基金the National Science Foundation for Distinguished Young Scholars(No.JQ23007)the Beijing Natural Science Foundation(No.JQ23007)the special fund for Science and Technology Innovation Teams of Shanxi Province(No.202304051001026)。
文摘Intrinsic ferroelectric materials play a critical role in the development of high-density integrated device. Despite some two-dimensional (2D) ferroelectrics have been reported, the research on one-dimensional (1D) intrinsic ferroelectric materials remains relatively scare since 1D atomic structures limit their van der Waals (vdW) epitaxy growth. Here, we report the synthesis of 1D intrinsic vdW ferroelectric SbSI nanowires via a confined-space chemical vapor deposition. By precisely controlling the partial vapor pressure of I2 and reaction temperature, we can effectively manipulate kinetics and thermodynamics processes, and thus obtain high quality of SbSI nanowires, which is determined by Raman spectroscopy and high-resolution scanning transmission electron microscopy characterizations. The ferroelectricity in SbSI is confirmed by piezo-response force microscopy measurements and the ferroelectric transition temperature of 300 K is demonstrated by second harmonic generation. Moreover, the in-plane polarization switching can be maintained in the thin SbSI nanowires with a thickness of 20 nm. Our prepared 1D vdW ferroelectric SbSI nanowires not only enrich the vdW ferroelectric systems, but also open a new possibility for high-power energy storage nanodevices.
