Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the...Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the coordination with virtual power plants(VPPs).The proposed strategy improves systemflexibility and responsiveness by optimizing the power adjustment of flexible resources.In the proposed strategy,theGaussian Process Regression(GPR)is firstly employed to determine the adjustable range of aggregated power within the VPP,facilitating an assessment of its potential contribution to power supply support.Then,an optimal dispatch model based on a leader-follower game is developed to maximize the benefits of the VPP and flexible resources while guaranteeing the power balance at the same time.To solve the proposed optimal dispatch model efficiently,the constraints of the problem are reformulated and resolved using the Karush-Kuhn-Tucker(KKT)optimality conditions and linear programming duality theorem.The effectiveness of the strategy is illustrated through a detailed case study.展开更多
Endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)are well-established therapeutics for gastrointestinal neoplasias,but complications after EMR/ESD,including bleeding and perforation,result in ...Endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)are well-established therapeutics for gastrointestinal neoplasias,but complications after EMR/ESD,including bleeding and perforation,result in additional treatment morbidity and even threaten the lives of patients.Thus,designing biomaterials to treat gastric bleeding and wound healing after endoscopic treatment is highly desired and remains a challenge.Herein,a series of injectable pH-responsive selfhealing adhesive hydrogels based on acryloyl-6-aminocaproic acid(AA)and AA-g-N-hydroxysuccinimide(AA-NHS)were developed,and their great potential as endoscopic sprayable bioadhesive materials to efficiently stop hemorrhage and promote the wound healing process was further demonstrated in a swine gastric hemorrhage/wound model.The hydrogels showed a suitable gelation time,an autonomous and efficient self-healing capacity,hemostatic properties,and good biocompatibility.With the introduction of AA-NHS as a micro-cross-linker,the hydrogels exhibited enhanced adhesive strength.A swine gastric hemorrhage in vivo model demonstrated that the hydrogels showed good hemostatic performance by stopping acute arterial bleeding and preventing delayed bleeding.A gastric wound model indicated that the hydrogels showed excellent treatment effects with significantly enhanced wound healing with type I collagen deposition,α-SMA expression,and blood vessel formation.These injectable self-healing adhesive hydrogels exhibited great potential to treat gastric wounds after endoscopic treatment.展开更多
Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous nar...Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous narrow beams,and complex satellite-terrestrial channels,the initial access between the LEO satellites and user terminals(UEs)becomes more complicated.To establish a stable link,a beam search is required between the satellite and the UE.However,tradi-tional beam search methods(e.g.,exhaustive search)have high time complexity which is not suit-able in high-speed scenarios.Therefore,in this paper,a sensing-aided hierarchical beam search method is proposed,which is performed in two stages.In the first stage,wide beam scanning is per-formed to find the optimal angular range.In the second stage,after determining the directions of narrow beams via sensing the direction of arrival(DOA)of satellite signals,the narrow beams gen-erated at estimated directions are used to sweep the satellite beams.This method can help fast beam alignment and obtain high beam search accuracy,which is verified by simulation results.Moreover,we analyze the gain of beam alignment from the two-stage beam search method.展开更多
臭氧是一种环境友好型氧化剂,可直接用于消毒、杀菌和废水处理,对于维护和促进公共卫生安全至关重要.由于臭氧容易分解,不利于储存,因此需要现制即用.目前臭氧生成技术主要包括:电晕放电法和电催化臭氧生产(EOP)技术.相较于电晕放电法,...臭氧是一种环境友好型氧化剂,可直接用于消毒、杀菌和废水处理,对于维护和促进公共卫生安全至关重要.由于臭氧容易分解,不利于储存,因此需要现制即用.目前臭氧生成技术主要包括:电晕放电法和电催化臭氧生产(EOP)技术.相较于电晕放电法,EOP是一种本质安全的臭氧生产技术.然而,该工艺相较于电晕放电技术电能消耗量大,为了使其更具商业可行性,有必要开发高活性且低成本的电催化剂.此外,合理的电解槽设计对于实现高效EOP过程也至关重要.然而,目前研究主要集中在提高EOP催化剂活性方面,对电解槽的结构设计优化的关注较少.本文通过开发高效电催化剂进而将其应用于结构优化后的电解槽中,实现了更加高效的EOP过程.本文采用水热方法成功制备了一种具有较高EOP活性的方形氧化铅(PbO_(x)-CTAB-120)电催化剂.在标准三电极测试系统中,电流密度为50 mA cm^(-2)的测试条件下,法拉第效率(FE)可达20.7%,与商用β-PbO_(2)(17.1%)相比提高了21.1%.此外,设计了具有平行流场的可视化EOP电解槽,该可视化电解槽在传质和传热方面具有明显优势,有利于实现更加高效的EOP过程.将催化剂PbO_(x)-CTAB-120组装至可视化电解槽中,在1.0 A cm^(-2)的测试电流密度下,电解液为超纯水,该体系气态臭氧产量可以达到588 mg h^(-1)g^(-1)catalyst,比能量消耗(PEOP)为56 Wh g^(-1)gaseous ozone.体系臭氧产量约为商用β-PbO_(2)在传统电解槽中产量的2倍,并且PEOP降低率超过62%.原位18O同位素标记差分电化学质谱和密度泛函理论计算结果表明,PbO_(x)-CTAB-120电催化剂在EOP过程中遵循晶格氧机理路径,晶格氧迁移产生的氧空位能有效稳定OOH^(*)和O_(2)^(*)反应中间体,因此有利于催化剂在EOP过程中保持较好的反应活性和稳定性.同时,还利用先进的高速摄像可视化工具和计算流体力学(CFD)仿真模拟研究了平行流场EOP电解槽的运行过程和高效传质传热的原理.CFD模拟结果表明,与传统流场模型相比,平行流场对应的出口气泡停留时间更长,说明平行流场更有利于产物气泡从出口逸出,即气泡容易快速扩散,与实验结果一致.因此,PbO_(x)-CTAB-120电催化剂与新型可视化电解槽相结合,有助于在超纯水中实现较好的气态臭氧产率和较低比能耗.此外,二者的结合充分发挥了电催化剂的EOP活性和电解槽的传质特性所带来的优势,实现了反应性和传输性的协同增强,从而极大促进了原位有机污染物降解效率.综上所述,本文在制备高效阳极催化剂的基础上,同时利用优化电解槽结构实现了提升臭氧产率和降低过程能耗,为高活性电催化剂与优化的电解槽耦合以实现高效EOP过程及其有效应用提供参考.展开更多
Multi-label text categorization refers to the problem of categorizing text througha multi-label learning algorithm. Text classification for Asian languages such as Chinese isdifferent from work for other languages suc...Multi-label text categorization refers to the problem of categorizing text througha multi-label learning algorithm. Text classification for Asian languages such as Chinese isdifferent from work for other languages such as English which use spaces to separate words.Before classifying text, it is necessary to perform a word segmentation operation to converta continuous language into a list of separate words and then convert it into a vector of acertain dimension. Generally, multi-label learning algorithms can be divided into twocategories, problem transformation methods and adapted algorithms. This work will usecustomer's comments about some hotels as a training data set, which contains labels for allaspects of the hotel evaluation, aiming to analyze and compare the performance of variousmulti-label learning algorithms on Chinese text classification. The experiment involves threebasic methods of problem transformation methods: Support Vector Machine, Random Forest,k-Nearest-Neighbor;and one adapted algorithm of Convolutional Neural Network. Theexperimental results show that the Support Vector Machine has better performance.展开更多
[Objectives]To determine the content of hyperin and luteolin in Vernonia cinerea(L.)Less.,and to provide basic experimental data for experimental research and clinical application of V.cinerea(L.)Less.[Methods]The com...[Objectives]To determine the content of hyperin and luteolin in Vernonia cinerea(L.)Less.,and to provide basic experimental data for experimental research and clinical application of V.cinerea(L.)Less.[Methods]The components to be determined were extracted by ultrasonic extraction,and the hyperin and luteolin in V.cinerea(L.)Less.were separated and determined by reversed-phase high performance liquid chromatography(chromatographic conditions:reverse C 18 column,methanol-0.4%phosphoric acid as mobile phase for gradient elution,flow rate of 1.0 mL/min,detector wavelength of 360 nm).[Results]The precision and repeatability of the experimental method were good,and the solution of V.cinerea(L.)Less.was stable within 18 h.There was a good linear relationship between the injection volume of hyperin and luteolin and the chromatographic peak area within the prescribed range,and the recovery rate was qualified.The content of hyperin and luteolin in V.cinerea(L.)Less.was 0.0665 mg/g(n=3)and 0.1004 mg/g(n=3),respectively.[Conclusions]The experimental method is sensitive,specific,stable,accurate and reliable,and can be used for the determination of hyperin and luteolin in V.cinerea(L.)Less.展开更多
Objective:We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release.Impact Statement:This design is inspired by the skin baroreceptors,which are mechanosensitive elements of...Objective:We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release.Impact Statement:This design is inspired by the skin baroreceptors,which are mechanosensitive elements of the peripheral nervous system.We adopt the finger touching to trigger the electric stimulation,ensuring a fast-response and user-friendly administration with potentially minimal off-target effects.Introduction:Chronic skin diseases bring about large,recurrent skin damage and often require convenient and timely transdermal treatment.Traditional methods lack spatiotemporal controllable dosage,leaving a risk of skin irritation or drug resistance issues.Methods:The patch consists of drug-containing microneedles and stretchable electrode array.The electrode array,integrated with the piezoconductive switch and flexible battery,provides a mild electric current only at the spot that is pressed.Drugs in microneedles will then flow along the current into the skin tissues.The stretchable feature also provides the mechanical robustness and electric stability of the device on large skin area.Results:This device delivers Cy3 dye in pig skin with spatiotemporally controlled dosage,showing~8 times higher fluorescence intensity than the passive delivery.We also deliver insulin and observe the reduction of the blood glucose level in the mouse model upon pressing.Compared with passive delivery without pressing,the dosage of drugs released by the simulation is 2.83 times higher.Conclusion:This baroreceptor-inspired microneedle skin patch acts as a good example of the biomimicking microneedle device in the precise control of the drug release profile at the spatiotemporal resolution.展开更多
Transdermal drug delivery systems(TDDs) avoid gastrointestinal degradation and hepatic first-pass metabolism, providing good drug bioavailability and patient compliance. One emerging type of TDDs is the wearable patch...Transdermal drug delivery systems(TDDs) avoid gastrointestinal degradation and hepatic first-pass metabolism, providing good drug bioavailability and patient compliance. One emerging type of TDDs is the wearable patch worn on the skin surface to deliver medication through the skin. They can generally be grouped into passive and active types, depending on the properties of materials,design principles and integrated devices. This review describes the latest advancement in the development of wearable patches, focusing on the integration of stimulus-responsive materials and electronics.This development is deemed to provide a dosage, temporal, and spatial control of therapeutics delivery.展开更多
In this paper,the electromagnetic scattering from overfilled cavities with inhomogeneous anisotropic media is investigated.To solve the scattering problem,a Petrov-Galerkin finite element interfacemethod on non-body-f...In this paper,the electromagnetic scattering from overfilled cavities with inhomogeneous anisotropic media is investigated.To solve the scattering problem,a Petrov-Galerkin finite element interfacemethod on non-body-fitted grids is presented.We reduce the infinite domain of scattering to a bounded domain problem by introducing a transparent boundary condition.The level set function is used to capture complex boundary and interface geometry that is not aligned with the mesh.Nonbody-fitted grids allow us to save computational costs during mesh generation and significantly reduce the amount of computer memory required.The solution is built by connecting two linear polynomials across the interfaces to satisfy the jump conditions.The proposed method can handle matrix coefficients produced by permittivity and permeability tensors of anisotropic media.The final linear system is sparse,making it more suitable for most iterative methods.Numerical experiments show that the proposed method has good convergence and realizability.Meanwhile,we discover that the absorbing properties of anisotropic media clearly and positively influence the reduction of radar cross section.It has also been demonstrated that the method can achieve second-order accuracy.展开更多
Background:Diagnosis of fatal hypothermia is challenging by autopsy approach alone.Aims and Objectives:To explore the features of fatal hypothermia on postmortem computed tomography(PMCT)and study their diagnostic val...Background:Diagnosis of fatal hypothermia is challenging by autopsy approach alone.Aims and Objectives:To explore the features of fatal hypothermia on postmortem computed tomography(PMCT)and study their diagnostic value in such cases.Materials and Methods:A retrospective study was conducted on the imaging data of three cases of low-temperature death.The study compared the images of lung tissue in the control group and used statistical tools to analyze typical changes associated with low-temperature death.The potential applications of cadaveric imaging in these cases were also discussed.Results:The typical postmortem imaging manifestations of death from hypothermia include increased volume of bilateral lung tissue,decreased density of bilateral lung tissue,and absence of pulmonary hypostasis.By comparison,it has been proven that PMCT can quickly detect typical changes in postmortem imaging of death from hypothermia.After applying PMCT,combined with the results of postmortem imaging,physical and chemical,and the environmental condition of the scene,in the absence of individual deaths because of other reasons,it can be determined that the individual died from hypothermia.Conclusions:The case of the death from hypothermia is a tough issue in forensic pathology examination.Through this review,it was found that the death from hypothermia cases have typical postmortem imaging.After combining the case,on-site investigation,and toxicology testing,we found the PMCT can solve the case of the death from hypothermia.展开更多
Skin-integrated electronics,also known as electronic skin(e-skin);are rapidly developing and are gradually being adopted in biomedical fields as well as in our daily lives.E-skin capable of providing sensitive and hig...Skin-integrated electronics,also known as electronic skin(e-skin);are rapidly developing and are gradually being adopted in biomedical fields as well as in our daily lives.E-skin capable of providing sensitive and high-resolution tactile sensations and haptic feedback to the human body would open a new e-skin paradigm for closed-loop human-machine interfaces.Here,we report a class of materials and mechanical designs for the miniaturization of mechanical actuators and strategies for their integration into thin,soft e-skin for haptic interfaces.The mechanical actuators exhibit small dimensions of 5 mm diameter and 1.45 mm thickness and work in an electromagnetically driven vibrotactile mode with resonance frequency overlapping the most sensitive frequency of human skin.Nine mini actuators can be integrated simultaneously in a small area of 2 cm×2 cm to form a 3×3 haptic feedback array,which is small and compact enough to mount on a thumb tip.Furthermore,the thin,soft haptic interface exhibits good mechanical properties that work properly during stretching,bending,and twisting and therefore can conformally fit onto various parts of the human body to afford programmable tactile enhancement and Braille recognition with an accuracy rate over 85%.展开更多
The premature failure phenomenon that occurs in solid insulation under the application of repetitive impulse voltages is known as the accumulative effect of impulse voltages on a solid dielectric.The accumulative fail...The premature failure phenomenon that occurs in solid insulation under the application of repetitive impulse voltages is known as the accumulative effect of impulse voltages on a solid dielectric.The accumulative failure of winding insulation is considered to be a core problem resulting from this phenomenon.The main problems include the accumulative failure of motor winding insulation under pulse-width modulation impulses and the accumulative failure of transformer winding insulation under the application of overvoltages,and these problems represent new challenges in the safe and stable operation of power grids.With regards to the above problems,this study reviews the results of recent research on the accumulative failure characteristics and mechanisms of winding insulation when subjected to repetitive impulse voltages.The challenges faced are discussed at the end of this study.展开更多
Background:As traditional autopsy rates decline,the importance of forensic imaging,particularly postmortem computed tomography(PMCT),grows for non-invasive cause of death determination and evidence collection in legal...Background:As traditional autopsy rates decline,the importance of forensic imaging,particularly postmortem computed tomography(PMCT),grows for non-invasive cause of death determination and evidence collection in legal investigations,with unique considerations required for frozen corpses due to the lack of systematic imaging characteristic studies.Aims and Objectives:This study aims to fill the gap in current knowledge by systematically analyzing the PMCT imaging characteristics of frozen corpses.Materials and Methods:This study utilized postmortem computed tomography(PMCT)and postmortem computed tomography angiography(PMCTA)to examine tissue changes during the freezing and thawing process in a total of 61 corpses.Results:The results demonstrated that imaging changes in the brain were most pronounced during freezing and thawing,with a clear correlation to the duration of freezing/thawing and the position of the corpses.Typical ice crystal artifacts were observed in body fluids after freezing,while thawing led to a marked increase and redistribution of internal gas.Serial angiographic studies revealed"pseudo-brain hemorrhage"in the brainstem and cerebellum in several cases due to incomplete thawing and transport.Conclusion:This study provides a comprehensive analysis of the CT imaging characteristics of frozen corpses,elucidating the imaging features during the freezing and thawing processes.展开更多
基金supported by the Science and Technology Project of Sichuan Electric Power Company“Power Supply Guarantee Strategy for Urban Distribution Networks Considering Coordination with Virtual Power Plant during Extreme Weather Event”(No.521920230003).
文摘Ensuring reliable power supply in urban distribution networks is a complex and critical task.To address the increased demand during extreme scenarios,this paper proposes an optimal dispatch strategy that considers the coordination with virtual power plants(VPPs).The proposed strategy improves systemflexibility and responsiveness by optimizing the power adjustment of flexible resources.In the proposed strategy,theGaussian Process Regression(GPR)is firstly employed to determine the adjustable range of aggregated power within the VPP,facilitating an assessment of its potential contribution to power supply support.Then,an optimal dispatch model based on a leader-follower game is developed to maximize the benefits of the VPP and flexible resources while guaranteeing the power balance at the same time.To solve the proposed optimal dispatch model efficiently,the constraints of the problem are reformulated and resolved using the Karush-Kuhn-Tucker(KKT)optimality conditions and linear programming duality theorem.The effectiveness of the strategy is illustrated through a detailed case study.
基金This work was jointly supported by the National Natural Science Foundation of China(grant Nos.:51973172,51673155,81201927,82002957 and 81672460)the National Key Research and Development Plan of China(No.2018YFC0115300)+5 种基金the State Key Laboratory for Mechanical Behavior of Materials,the World-Class Universities(Disciplines)the Characteristic Development Guidance Funds for the Central Universities,the Natural Science Foundation of Shaanxi Province(No.2020JC-03 and 2019TD-020)the Innovation Talent Promotion Plan of Shaanxi(No.2017KJXX-07)the Key Research and Development Program of Shaanxi Province(No.2019SF-012)the Opening Project of Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research,College of Stomatology,Xi’an Jiaotong University(No.2019LHM-KFKT008)Fundamental Research Funds for the Central Universities of China(No.xjj2018090).
文摘Endoscopic mucosal resection(EMR)and endoscopic submucosal dissection(ESD)are well-established therapeutics for gastrointestinal neoplasias,but complications after EMR/ESD,including bleeding and perforation,result in additional treatment morbidity and even threaten the lives of patients.Thus,designing biomaterials to treat gastric bleeding and wound healing after endoscopic treatment is highly desired and remains a challenge.Herein,a series of injectable pH-responsive selfhealing adhesive hydrogels based on acryloyl-6-aminocaproic acid(AA)and AA-g-N-hydroxysuccinimide(AA-NHS)were developed,and their great potential as endoscopic sprayable bioadhesive materials to efficiently stop hemorrhage and promote the wound healing process was further demonstrated in a swine gastric hemorrhage/wound model.The hydrogels showed a suitable gelation time,an autonomous and efficient self-healing capacity,hemostatic properties,and good biocompatibility.With the introduction of AA-NHS as a micro-cross-linker,the hydrogels exhibited enhanced adhesive strength.A swine gastric hemorrhage in vivo model demonstrated that the hydrogels showed good hemostatic performance by stopping acute arterial bleeding and preventing delayed bleeding.A gastric wound model indicated that the hydrogels showed excellent treatment effects with significantly enhanced wound healing with type I collagen deposition,α-SMA expression,and blood vessel formation.These injectable self-healing adhesive hydrogels exhibited great potential to treat gastric wounds after endoscopic treatment.
基金supported in part by Chongqing Natural Science Foundation Innovation and Development Joint Fund(No.CSTB2024NSCQ-LMX0024)in part by Shanghai Natu-ral Science Foundation(No.24ZR1421800)。
文摘Low earth orbit(LEO)satellite communication which can provide global wireless ser-vice plays a critical role in the future wireless communication networks.However,due to the high speed of satellite motion,numerous narrow beams,and complex satellite-terrestrial channels,the initial access between the LEO satellites and user terminals(UEs)becomes more complicated.To establish a stable link,a beam search is required between the satellite and the UE.However,tradi-tional beam search methods(e.g.,exhaustive search)have high time complexity which is not suit-able in high-speed scenarios.Therefore,in this paper,a sensing-aided hierarchical beam search method is proposed,which is performed in two stages.In the first stage,wide beam scanning is per-formed to find the optimal angular range.In the second stage,after determining the directions of narrow beams via sensing the direction of arrival(DOA)of satellite signals,the narrow beams gen-erated at estimated directions are used to sweep the satellite beams.This method can help fast beam alignment and obtain high beam search accuracy,which is verified by simulation results.Moreover,we analyze the gain of beam alignment from the two-stage beam search method.
文摘臭氧是一种环境友好型氧化剂,可直接用于消毒、杀菌和废水处理,对于维护和促进公共卫生安全至关重要.由于臭氧容易分解,不利于储存,因此需要现制即用.目前臭氧生成技术主要包括:电晕放电法和电催化臭氧生产(EOP)技术.相较于电晕放电法,EOP是一种本质安全的臭氧生产技术.然而,该工艺相较于电晕放电技术电能消耗量大,为了使其更具商业可行性,有必要开发高活性且低成本的电催化剂.此外,合理的电解槽设计对于实现高效EOP过程也至关重要.然而,目前研究主要集中在提高EOP催化剂活性方面,对电解槽的结构设计优化的关注较少.本文通过开发高效电催化剂进而将其应用于结构优化后的电解槽中,实现了更加高效的EOP过程.本文采用水热方法成功制备了一种具有较高EOP活性的方形氧化铅(PbO_(x)-CTAB-120)电催化剂.在标准三电极测试系统中,电流密度为50 mA cm^(-2)的测试条件下,法拉第效率(FE)可达20.7%,与商用β-PbO_(2)(17.1%)相比提高了21.1%.此外,设计了具有平行流场的可视化EOP电解槽,该可视化电解槽在传质和传热方面具有明显优势,有利于实现更加高效的EOP过程.将催化剂PbO_(x)-CTAB-120组装至可视化电解槽中,在1.0 A cm^(-2)的测试电流密度下,电解液为超纯水,该体系气态臭氧产量可以达到588 mg h^(-1)g^(-1)catalyst,比能量消耗(PEOP)为56 Wh g^(-1)gaseous ozone.体系臭氧产量约为商用β-PbO_(2)在传统电解槽中产量的2倍,并且PEOP降低率超过62%.原位18O同位素标记差分电化学质谱和密度泛函理论计算结果表明,PbO_(x)-CTAB-120电催化剂在EOP过程中遵循晶格氧机理路径,晶格氧迁移产生的氧空位能有效稳定OOH^(*)和O_(2)^(*)反应中间体,因此有利于催化剂在EOP过程中保持较好的反应活性和稳定性.同时,还利用先进的高速摄像可视化工具和计算流体力学(CFD)仿真模拟研究了平行流场EOP电解槽的运行过程和高效传质传热的原理.CFD模拟结果表明,与传统流场模型相比,平行流场对应的出口气泡停留时间更长,说明平行流场更有利于产物气泡从出口逸出,即气泡容易快速扩散,与实验结果一致.因此,PbO_(x)-CTAB-120电催化剂与新型可视化电解槽相结合,有助于在超纯水中实现较好的气态臭氧产率和较低比能耗.此外,二者的结合充分发挥了电催化剂的EOP活性和电解槽的传质特性所带来的优势,实现了反应性和传输性的协同增强,从而极大促进了原位有机污染物降解效率.综上所述,本文在制备高效阳极催化剂的基础上,同时利用优化电解槽结构实现了提升臭氧产率和降低过程能耗,为高活性电催化剂与优化的电解槽耦合以实现高效EOP过程及其有效应用提供参考.
基金supported by the NSFC (Grant Nos. 61772281,61703212, 61602254)Jiangsu Province Natural Science Foundation [grant numberBK2160968]the Priority Academic Program Development of Jiangsu Higher Edu-cationInstitutions (PAPD) and Jiangsu Collaborative Innovation Center on AtmosphericEnvironment and Equipment Technology (CICAEET).
文摘Multi-label text categorization refers to the problem of categorizing text througha multi-label learning algorithm. Text classification for Asian languages such as Chinese isdifferent from work for other languages such as English which use spaces to separate words.Before classifying text, it is necessary to perform a word segmentation operation to converta continuous language into a list of separate words and then convert it into a vector of acertain dimension. Generally, multi-label learning algorithms can be divided into twocategories, problem transformation methods and adapted algorithms. This work will usecustomer's comments about some hotels as a training data set, which contains labels for allaspects of the hotel evaluation, aiming to analyze and compare the performance of variousmulti-label learning algorithms on Chinese text classification. The experiment involves threebasic methods of problem transformation methods: Support Vector Machine, Random Forest,k-Nearest-Neighbor;and one adapted algorithm of Convolutional Neural Network. Theexperimental results show that the Support Vector Machine has better performance.
基金Supported by Independent Research Project of Key Laboratory of Extraction,Purification and Quality Analysis of Traditional Chinese Medicine in Guangxi Universities(J1606701).
文摘[Objectives]To determine the content of hyperin and luteolin in Vernonia cinerea(L.)Less.,and to provide basic experimental data for experimental research and clinical application of V.cinerea(L.)Less.[Methods]The components to be determined were extracted by ultrasonic extraction,and the hyperin and luteolin in V.cinerea(L.)Less.were separated and determined by reversed-phase high performance liquid chromatography(chromatographic conditions:reverse C 18 column,methanol-0.4%phosphoric acid as mobile phase for gradient elution,flow rate of 1.0 mL/min,detector wavelength of 360 nm).[Results]The precision and repeatability of the experimental method were good,and the solution of V.cinerea(L.)Less.was stable within 18 h.There was a good linear relationship between the injection volume of hyperin and luteolin and the chromatographic peak area within the prescribed range,and the recovery rate was qualified.The content of hyperin and luteolin in V.cinerea(L.)Less.was 0.0665 mg/g(n=3)and 0.1004 mg/g(n=3),respectively.[Conclusions]The experimental method is sensitive,specific,stable,accurate and reliable,and can be used for the determination of hyperin and luteolin in V.cinerea(L.)Less.
基金support by General Research Fund(GRF)grant from the Research Grants Council(RGC)of the Hong Kong Special Administrative Region China(CityU11200820,CityU11100323)the Mainland/Hong Kong Joint Research Scheme sponsored by the RGC Hong Kong and the National Natural Science Foundation of China(N_CityU118/20).
文摘Objective:We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release.Impact Statement:This design is inspired by the skin baroreceptors,which are mechanosensitive elements of the peripheral nervous system.We adopt the finger touching to trigger the electric stimulation,ensuring a fast-response and user-friendly administration with potentially minimal off-target effects.Introduction:Chronic skin diseases bring about large,recurrent skin damage and often require convenient and timely transdermal treatment.Traditional methods lack spatiotemporal controllable dosage,leaving a risk of skin irritation or drug resistance issues.Methods:The patch consists of drug-containing microneedles and stretchable electrode array.The electrode array,integrated with the piezoconductive switch and flexible battery,provides a mild electric current only at the spot that is pressed.Drugs in microneedles will then flow along the current into the skin tissues.The stretchable feature also provides the mechanical robustness and electric stability of the device on large skin area.Results:This device delivers Cy3 dye in pig skin with spatiotemporally controlled dosage,showing~8 times higher fluorescence intensity than the passive delivery.We also deliver insulin and observe the reduction of the blood glucose level in the mouse model upon pressing.Compared with passive delivery without pressing,the dosage of drugs released by the simulation is 2.83 times higher.Conclusion:This baroreceptor-inspired microneedle skin patch acts as a good example of the biomimicking microneedle device in the precise control of the drug release profile at the spatiotemporal resolution.
基金support by Strategic Interdisciplinary Research Grant (7020029) from City University of Hong KongGeneral Research Fund (GRF) grant from the Research Grants Council (RGC) of the Hong Kong Special Administrative Region, China (City U 11200820, 11202222)+2 种基金the Mainland/Hong Kong Joint Research Scheme sponsored by the RGC Hong Kongthe National Natural Science Foundation of China (N_City U118/20)the Inno HK funding support from the Hong Kong Centre for Cerebro-cardiovascular Health Engineering (COCHE)。
文摘Transdermal drug delivery systems(TDDs) avoid gastrointestinal degradation and hepatic first-pass metabolism, providing good drug bioavailability and patient compliance. One emerging type of TDDs is the wearable patch worn on the skin surface to deliver medication through the skin. They can generally be grouped into passive and active types, depending on the properties of materials,design principles and integrated devices. This review describes the latest advancement in the development of wearable patches, focusing on the integration of stimulus-responsive materials and electronics.This development is deemed to provide a dosage, temporal, and spatial control of therapeutics delivery.
基金supported by the National Natural Science Foundation of China(No.12271159)the Natural Science Foundation of Hebei Province(No.A2020502003)+2 种基金the Fundamental Research Funds for the Central Universities(No.2021MS115)supported by the National Natural Science Foundation of China(No.12171482)the State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(No.PRP/DX-2307).
文摘In this paper,the electromagnetic scattering from overfilled cavities with inhomogeneous anisotropic media is investigated.To solve the scattering problem,a Petrov-Galerkin finite element interfacemethod on non-body-fitted grids is presented.We reduce the infinite domain of scattering to a bounded domain problem by introducing a transparent boundary condition.The level set function is used to capture complex boundary and interface geometry that is not aligned with the mesh.Nonbody-fitted grids allow us to save computational costs during mesh generation and significantly reduce the amount of computer memory required.The solution is built by connecting two linear polynomials across the interfaces to satisfy the jump conditions.The proposed method can handle matrix coefficients produced by permittivity and permeability tensors of anisotropic media.The final linear system is sparse,making it more suitable for most iterative methods.Numerical experiments show that the proposed method has good convergence and realizability.Meanwhile,we discover that the absorbing properties of anisotropic media clearly and positively influence the reduction of radar cross section.It has also been demonstrated that the method can achieve second-order accuracy.
文摘Background:Diagnosis of fatal hypothermia is challenging by autopsy approach alone.Aims and Objectives:To explore the features of fatal hypothermia on postmortem computed tomography(PMCT)and study their diagnostic value in such cases.Materials and Methods:A retrospective study was conducted on the imaging data of three cases of low-temperature death.The study compared the images of lung tissue in the control group and used statistical tools to analyze typical changes associated with low-temperature death.The potential applications of cadaveric imaging in these cases were also discussed.Results:The typical postmortem imaging manifestations of death from hypothermia include increased volume of bilateral lung tissue,decreased density of bilateral lung tissue,and absence of pulmonary hypostasis.By comparison,it has been proven that PMCT can quickly detect typical changes in postmortem imaging of death from hypothermia.After applying PMCT,combined with the results of postmortem imaging,physical and chemical,and the environmental condition of the scene,in the absence of individual deaths because of other reasons,it can be determined that the individual died from hypothermia.Conclusions:The case of the death from hypothermia is a tough issue in forensic pathology examination.Through this review,it was found that the death from hypothermia cases have typical postmortem imaging.After combining the case,on-site investigation,and toxicology testing,we found the PMCT can solve the case of the death from hypothermia.
基金the City University of Hong Kong(Grant Nos.9610423,9667199,9667221,9680322)Research Grants Council of the Hong Kong Special Administrative Region(Grant Nos.21210820,11213721)+5 种基金Hong Kong Center for Cerebra-Cardiovascular Health Engineering,Tencent Robotics X(Grant No.9231409)Shenzhen Science and Technology Innovation Commission(Grant No.JCYJ20200109110201713)Science and Technology of Sichuan Province(Grant No.2020YFH0181)National Natural Science Foundation of China(Grant No.12072057)LiaoNing Revitalization Talents Program(Grant No.XLYC2007196)Fundamental Research Funds for the Central Universities(Grant No.DUT20RC⑶032).
文摘Skin-integrated electronics,also known as electronic skin(e-skin);are rapidly developing and are gradually being adopted in biomedical fields as well as in our daily lives.E-skin capable of providing sensitive and high-resolution tactile sensations and haptic feedback to the human body would open a new e-skin paradigm for closed-loop human-machine interfaces.Here,we report a class of materials and mechanical designs for the miniaturization of mechanical actuators and strategies for their integration into thin,soft e-skin for haptic interfaces.The mechanical actuators exhibit small dimensions of 5 mm diameter and 1.45 mm thickness and work in an electromagnetically driven vibrotactile mode with resonance frequency overlapping the most sensitive frequency of human skin.Nine mini actuators can be integrated simultaneously in a small area of 2 cm×2 cm to form a 3×3 haptic feedback array,which is small and compact enough to mount on a thumb tip.Furthermore,the thin,soft haptic interface exhibits good mechanical properties that work properly during stretching,bending,and twisting and therefore can conformally fit onto various parts of the human body to afford programmable tactile enhancement and Braille recognition with an accuracy rate over 85%.
基金the National Natural Science Foundation of China(51707023)the National Basic Research Program(973 Program)(2015CB251003)+2 种基金the National Key R&D Program of China(2017YFB0902702)the China's Postdoctoral Science Fund(2017M622962)the Chongqing Postdoctoral Science Special Foundation(Xm2017197).
文摘The premature failure phenomenon that occurs in solid insulation under the application of repetitive impulse voltages is known as the accumulative effect of impulse voltages on a solid dielectric.The accumulative failure of winding insulation is considered to be a core problem resulting from this phenomenon.The main problems include the accumulative failure of motor winding insulation under pulse-width modulation impulses and the accumulative failure of transformer winding insulation under the application of overvoltages,and these problems represent new challenges in the safe and stable operation of power grids.With regards to the above problems,this study reviews the results of recent research on the accumulative failure characteristics and mechanisms of winding insulation when subjected to repetitive impulse voltages.The challenges faced are discussed at the end of this study.
文摘Background:As traditional autopsy rates decline,the importance of forensic imaging,particularly postmortem computed tomography(PMCT),grows for non-invasive cause of death determination and evidence collection in legal investigations,with unique considerations required for frozen corpses due to the lack of systematic imaging characteristic studies.Aims and Objectives:This study aims to fill the gap in current knowledge by systematically analyzing the PMCT imaging characteristics of frozen corpses.Materials and Methods:This study utilized postmortem computed tomography(PMCT)and postmortem computed tomography angiography(PMCTA)to examine tissue changes during the freezing and thawing process in a total of 61 corpses.Results:The results demonstrated that imaging changes in the brain were most pronounced during freezing and thawing,with a clear correlation to the duration of freezing/thawing and the position of the corpses.Typical ice crystal artifacts were observed in body fluids after freezing,while thawing led to a marked increase and redistribution of internal gas.Serial angiographic studies revealed"pseudo-brain hemorrhage"in the brainstem and cerebellum in several cases due to incomplete thawing and transport.Conclusion:This study provides a comprehensive analysis of the CT imaging characteristics of frozen corpses,elucidating the imaging features during the freezing and thawing processes.
