非k积态基于Sandwiched Renyi相对熵的关联测度

在量子信息理论中,Sandwiched Renyi相对熵具有极其重要的应用价值。该研究给出多体复合系统非k积态基于Sandwiched Renyi相对熵的关联测度,同时证明了其满足量子关联度的一些必要性质,包括非负性,酉不变性,在完全正的保迹线性映射下的单调性,联合凸性以及在非相干辅助子系统影响下的不变性。

Phonon Thermal Transport at Interfaces of a Graphene/Vertically Aligned Carbon Nanotubes/Hexagonal Boron Nitride Sandwiched Heterostructure

Molecular dynamics simulation is used to calculate the interfacial thermal resistance of a graphene/carbon nanotubes/hexagonal boron nitride(Gr/CNTs/hBN)sandwiched heterostructure,in which vertically aligned carbon nanotube(VACNT)arrays are covalently bonded to graphene and hexagonal boron nitride layers.We find that the interfacial thermal resistance(ITR)of the Gr/VACNT/hBN sandwiched heterostructure is one to two orders of magnitude smaller than the ITR of a Gr/hBN van der Waals heterostructure with the same plane size.It is observed that covalent bonding effectively enhances the phonon coupling between Gr and hBN layers,resulting in an increase in the overlap factor of phonon density of states between Gr and hBN,thus reducing the ITR of Gr and hBN.In addition,the chirality,size(diameter and length),and packing density of sandwich-layer VACNTs have an important influence on the ITR of the heterostructure.Under the same CNT diameter and length,the ITR of the sandwiched heterostructure with armchair-shaped VACNTs is higher than that of the sandwiched heterostructure with zigzag-shaped VACNTs due to the different chemical bonding of chiral CNTs with Gr and hBN.When the armchair-shaped CNT diameter increases or the length decreases,the ITR of the sandwiched heterostructure tends to decrease.Moreover,the increase in the VACNT packing density also leads to a continuous decrease in the ITR of the sandwiched heterostructure,attributed to the extremely high intrinsic thermal conductivity of CNTs and the increase of out-of-plane heat transfer channels.This work may be helpful for understanding the mechanism for ITR in multilayer vertical heterostructures,and provides theoretical guidance for a new strategy to regulate the interlayer thermal resistance of heterostructures by optimizing the design of sandwich layer thermal interface materials.

Double casing warhead with sandwiched charge:The axial distribution of fragments velocities

The double casing warhead with sandwiched charge is a novel fragmentation warhead that can produce two groups of fragments with different velocity,and the previous work has presented a calculation formula to determine the maximum fragment velocity.The current work builds on the published formula to further develop a formula for calculating the axial distribution characteristics of the fragment velocity.For this type of warhead,the simulation of the dispersion characteristics of the detonation products at different positions shows that the detonation products at the ends have a much larger axial velocity than those in the middle,and the detonation products have a greater axial dispersion velocity when they are closer to the central axis.The loading process and the fragment velocity vary with the axial position for both casing layers,and the total velocity of the fragments is the vector sum of the radial velocity and the axial velocity.At the same axial position,the acceleration time of the inner casing is greater than that of the outer casing.For the same casing,the fragments generated at the ends have a longer acceleration time than the fragments from the middle.The proposed formula is validated with the X-ray radiography results of the four warheads previously tested experimentally and the 3D smoothedparticle hydrodynamics numerical simulation results of several series of new warheads with different configurations.The formula can accurately and reliably calculate the fragment velocity when the lengthto-diameter ratio of the charge is greater than 1.5 and the thickness of the casing is less than 20%its inner radius.This work thus provides a key reference for the theoretical analysis and the design of warheads with multiple casings.

PAD Class教学模式对英语专业学生写作焦虑影响的实证研究

本研究以英语专业大一120名学生为实验对象,进行了为期16周的实证研究,以探讨PAD class教学模式对英语专业学生写作焦虑的影响。基于《二语写作焦虑量表》调查问卷结果表明:英语专业学生总体焦虑处于中等焦虑水平,PAD Class能有效降低学生的写作总体焦虑,其中课堂焦虑、构思焦虑、自信焦虑明显降低,但回避焦虑没有达到显著水平;PAD Class模式对高中低不同写作水平学生的写作焦虑都有影响,对中、低水平学生的写作焦虑缓解比对高水平学生的影响效果更明显。

PBL-Sandwich混合教学模式在临床分子生物学检验技术实习教学中的应用

目的 探讨以问题为基础的教学法(PBL)-Sandwich混合教学模式在临床分子生物学检验技术实习教学中的应用效果。方法 选取2018-2019年进入该院分子生物学实验室实习的82例实习生作为研究对象。以2018年的42例实习生作为对照组,采用传统教学模式;以2019年的40例实习生作为试验组,采用PBL-Sandwich混合教学模式。实习结束后,采用理论考试、操作考核和问卷调查等形式评价实习生的教学效果。结果 试验组的理论考试成绩与操作考核成绩均明显高于对照组,差异均有统计学意义(P<0.05)。共发放调查问卷82份,回收有效问卷80份,其中试验组39份,对照组41份,有效回收率为97.56%(80/82)。试验组在提高学习主动性、激发学习兴趣、增强师生间的交流和互动、提升分析解决临床实际问题能力和教学方法实施满意度方面均优于对照组,差异均有统计学意义(P<0.05)。结论 PBL-Sandwich混合教学模式能有效激发实习生学习兴趣,培养实习生自主学习的主观能动性,提高分析、解决临床实际问题能力,教学质量得到提升。

案例教学法联合Sandwich教学法在老年科教学中的应用

目的探讨案例教学法联合Sandwich教学法在老年科教学中的应用效果。方法选取2022年3月—2023年6月潍坊医学院附属医院的60名参加老年科教学的学生为研究对象,按照随机数表法分为两组,各30名。对照组行常规教学,观察组行案例教学法联合Sandwich教学法教学,比较两组教学效果。结果观察组各项模拟出科考试成绩高于对照组,差异有统计学意义(P均<0.05);观察组对实习教学效果的各项满意度评分高于对照组,差异有统计学意义(P<0.05)。结论案例教学法联合Sandwich教学法可提升老年科教学的效果,并提高学生对实习教学效果的满意度。

Sandwich联合角色扮演教学法在住培医师医患沟通能力培训中的应用

目的 以腰椎穿刺术前谈话为例,探讨Sandwich联合角色扮演教学法在住院医师规范化培训(住培)学员医患沟通能力培训中的应用价值。方法 选取2019年3月至2023年1月在该院神经外科进行住培的40名学员,将其分为A、B组,每组20名。A组通过传统教学方法进行腰椎穿刺术前谈话的教学,B组运用Sandwich联合角色扮演教学法进行教学,在教学前、中、后期分别使用医患沟通技能评价量表对2组学员进行考评,最后对2组学员进行满意度问卷调查,对比2组教学效果及学员对教学的满意度。结果 2组学员在教学前测评得分均较低,在教学后测评较教学前均有提升,差异均有统计学意义(P<0.05);与A组比较,B组在教学中期测评得分明显更高,差异有统计学意义(P<0.05);2组在教学后期测评得分比较,差异无统计学意义(P>0.05)。B组住培学员的满意度高于A组,差异有统计学意义(P<0.05)。结论 Sandwich联合角色扮演教学法能快速提升学员的术前谈话沟通能力,也能提高学员的教学满意度,适合在相关教学活动中推广。

MDT+Sandwich教学法在本科内科学教学中的应用

目的探讨多学科诊疗(MDT)+“三明治”教学法(Sandwich教学法)与传统的以学科为基础的教学法在本科内科学教学中的应用效果。方法选取五年制临床医学专业60名本科生为研究对象,随机分为对照组(n=30)和试验组(n=30)。对照组采用传统的以学科为基础的教学法,试验组采用MDT+Sandwich教学法,课程结束后比较两组教学效果。结果试验组理论考试、临床技能操作考核成绩及课堂教学效果均优于对照组。结论在内科学教学中引入MDT+Sandwich教学法,能够更好地培养学生分析和解决临床问题能力。

Sandwich教学法融入思政教育在超声诊断学中的应用

研究Sandwich教学法融入思政教育模式在超声诊断学教学中应用效果。方法 选择2022年11月-2023年11月在本院接受超声诊断学教学的学生40名,随机分组法分作试验组(Sandwich教学法融入思政教育模式)和对照组(传统教学模式),每组20名,分析不同教学模式的实施效果评价。结果 出科时,试验组考核成绩明显高于对照组,P<0.05;试验组综合能力和批判性思维能力均优于对照组,P<0.05。结论 超声诊断学教学中实施Sandwich教学法融入思政教育模式,可明显提升学生考核成绩、综合素质以及批判性思维能力,可以应用于超声诊断学教学。

Boosting Lithium Storage in Graphene-Sandwiched Cathodes Containing Multi-Carbonyl Polyquinoneimine Nanosheets

Carbonyl polymers as booming electrode materials for lithium-organic batteries are currently limited by low practical capacities and poor rate performance due to their inherent electronic insulation and microscopic agglomeration morphologies.Herein graphene/carbonyl-enriched polyquinoneimine(PQI@Gr)composites were readily prepared by in situ hydrothermal polycondensation of dianhydride and anthraquinone co-monomer salts in the presence of graphene oxide(GO).Conductive graphene sheets derived from hydrothermal reduction of GO are fully sandwiched between densely interlaced quinone-containing polyimide nanosheets.Remarkably,the as-fabricated PQI@Gr cathodes exhibit much larger specific capacity(205 mAh g^(-1)at 0.1 A g^(-1)),higher carbonyl utilization(up to 89.9%),and better rate capability(179.4 mAh g^(-1)at 5.0 A g^(-1))due to a surface-dominated capacitive process via fast kinetics compared to bare PQI electrode(162.5 mAh g^(-1)at 0.1 A g^(-1);67.5%;96.9 mAh g^(-1)at 5 A g^(-1)).The capacity retention as high as 73%for PQI@Gr is also achieved over ultra-long 10000 cycles at 5.0 A g^(-1).Such outstanding electrochemical performances are attributable to the combined merits of polyimides and polyquinones,and robust 3D hierarchical heterostructures with efficient conductive networks,abundant porous channels for electrolyte infiltration and ion accessibility,and highly exposed carbonyl groups.This work offers new insights into the development of high-performance polymer electrodes for sustainable batteries.

Multi-field coupling and free vibration of a sandwiched functionally-graded piezoelectric semiconductor plate

Sandwiched functionally-graded piezoelectric semiconductor(FGPS)plates possess high strength and excellent piezoelectric and semiconductor properties,and have significant potential applications in micro-electro-mechanical systems.The multi-field coupling and free vibration of a sandwiched FGPS plate are studied,and the governing equation and natural frequency are derived with the consideration of electron movement.The material properties in the functionally-graded layers are assumed to vary smoothly,and the first-order shear deformation theory is introduced to derive the multi-field coupling in the plate.The total strain energy of the plate is obtained,and the governing equations are presented by using Hamilton’s principle.By introducing the boundary conditions,the coupling physical fields are solved.In numerical examples,the natural frequencies of sandwiched FGPS plates under different geometrical and physical parameters are discussed.It is found that the initial electron density can be used to modulate the natural frequencies and vibrational displacement of sandwiched FGPS plates in the case of nano-size.The effects of the material properties of FGPS layers on the natural frequencies are also examined in detail.

Sandwich教学方法在非本专业医学本科生临床见习中的应用效果

目的:探讨Sandwich教学方法应用于非麻醉专业本科生在麻醉临床见习中的应用效果。方法:本研究选择2021年4月在首都医科大学附属北京佑安医院参与临床麻醉学见习的51名本科护理学专业学生作为观察对象,根据随机表随机分为对照组(n=26)和试验组(n=25)。其中对照组采用常规的见习教学方法,而试验组采用Sandwich教学方法,最后两组采用理论知识试卷和满意度调查表进行教学效果和教师满意度评价。结果:理论知识掌握方面,试验组和对照组的平均得分分别是(81.80±5.02)分与(66.56±5.13)分,差异具有统计学意义(P<0.05);对见习带教老师满意度方面,试验组显著高于对照组,差异具有统计学意义(P<0.05)。结论:Sandwich教学方法不仅有利于见习生掌握教学大纲内容,而且还有利于提高学生对带教老师的满意度。

含根量对SANDWICH形加筋土界面剪切强度影响--以红叶石楠为例

SANDWICH形加筋土是一种采用粘土夹砂层以及土工格栅而形成的混合填料形式的加筋土结构。采用一系列直接剪切试验研究含根量、竖向应力等因素对筋土界面强度的影响。试验证明,根系的加入对SANDWICH形加筋土界面最大剪应力有所提升且随着竖向应力的增大,土体抗剪强度增幅大。随着粘土中含根量的增加,筋土界面最大剪应力在不同竖向应力作用下出现先增后减的趋势。根据试验数据,利用拟合软件提出了评价筋土界面剪切强度的经验公式,得出理论上含根量的最优值为4.2%。并通过试验验证了拟合公式的有效性和正确性。

Mechanical Performance of Bio-inspired Bidirectional Corrugated Sandwich Pressure Shell Under External Hydrostatic Pressure

This paper aims to enhance the compression capacity of underwater cylindrical shells by adopting the corrugated sandwich structure of cuttlebone.The cuttlebone suffers uniaxial external compression,while underwater cylindrical shells are in a biaxial compressive stress state.To suit the biaxial compressive stress state,a novel bidirectional corrugated sandwich structure is proposed to improve the bearing capacity of cylindrical shells.The static and buckling analysis for the sandwich shell and the unstiffened cylindrical shell with the same volume-weight ratio are studied by numerical simulation.It is indicated that the proposed sandwich shell can effectively reduce the ratio between circumferential and axial stress from 2 to 1.25 and improve the critical buckling load by about 1.63 times.Numerical simulation shows that optimizing and adjusting the structural parameters could significantly improve the advantage of the sandwich shell.Then,the hydrostatic pressure tests for shell models fabricated by 3D printing are carried out.According to the experimental results,the overall failure position of the sandwich shell is at the center part of the sandwich shell.It has been found the average critical load of the proposed sandwich shell models exceeds two times that of the unstiffened shell models.Hence,the proposed bio-inspired bidirectional corrugated sandwich structure can significantly enhance the pressure resistance capability of cylindrical shells.

基于岗位胜任力的WebQuest联合Sandwich教学法在超声医学本科教学的探索

超声医学是一门理论性和实践性较强的综合性学科,对从业人员的专业知识和操作技能均有较高要求。传统超声医学本科教育存在教师单方面授课无法激发学生学习兴趣以及学生实践时间严重不足等问题,超声医学专业人才岗位胜任力的培养存在一定难度。本文基于超声医学本科教学的实际情况,探讨以岗位胜任力为导向的WebQuest联合Sandwich教学法在超声医学专业本科教育体系中的应用前景。

Hybrid treatment of varied orthodontic appliances for a patient with skeletal class II and temporomandibular joint disorders:A case report and review of literature

BACKGROUND The relation between orthodontic treatment and temporomandibular disorders(TMDs)is under debate;the management of TMD during orthodontic treatment has always been a challenge.If TMD symptoms occur during orthodontic treatment,an immediate pause of orthodontic adjustments is recommended;the treatment can resume when the symptoms are managed and stabilized.CASE SUMMARY This case report presents a patient(26-year-old,female)with angle class I,skeletal class II and TMDs.The treatment was a hybrid of clear aligners,fixed appliances and temporary anchorage devices(TADs).After 3 mo resting and treatment on her TMD,the patient’s TMD symptom alleviated,but her anterior occlusion displayed deep overbite.Therefore,the fixed appliances with TAD were used to correct the anterior deep-bite and level maxillary and mandibular deep curves.After the levelling,the patient showed dual bite with centric relation and maximum intercuspation discrepancy on her occlusion.After careful examination of temporomandibular joints(TMJ)position,the stable bite splint and Invisible Mandibular Advancement appliance were used to reconstruct her occlusion.Eventually,the improved facial appearance and relatively stable occlusion were achieved.The 1-year follow-up records showed there was no obvious change in TMJ morphology,and her occlusion was stable.CONCLUSION TMD screening and monitoring is of great clinical importance in the TMD susceptible patients.Hybrid treatment with clear aligners and fixed appliances and TADs is an effective treatment modality for the complex cases.

Sandwich structures with tapered tubes as core:A quasi-static investigation

In this article,the experimental and finite element analysis is utilized to investigate the quasi-static compression features of sandwich constructions built with tapered tubes.3D printing technology was utilized to create the hollow centers of the tapering tubes,with and without corrugations.The results demonstrate that the energy absorption(EA)and specific energy absorption(SEA)of the single corrugated tapered tube sandwich are 51.6% and 19.8% higher,respectively,than those of the conical tube sandwich.Furthermore,the results demonstrate that energy absorbers can benefit from corrugation in order to increase their efficiency.Additionally,the tapered corrugated tubes'resistance to oblique impacts was studied.Compared to a straight tube,the tapered tube is more resistant to oblique loads and has a lower initial peak crushing force(PCF),according to numerical simulations.After conducting a parametric study,it was discovered that the energy absorption performance of the sandwich construction is significantly affected by the amplitude,number of corrugations,and wall thickness.EA and SEA of DTS with corrugation number of 8 increased by 17.4%and 29.6%,respectively,while PCF decreased by 9.2% compared to DTS with corrugation number of 10.

Nonlinear vibration of Timoshenko FG porous sandwich beams subjected to a harmonic axial load

In this study,the instability and bifurcation diagrams of a functionally graded(FG)porous sandwich beam on an elastic,viscous foundation which is influenced by an axial load,are investigated with an analytical attitude.To do so,the Timoshenko beam theory is utilized to take the shear deformations into account,and the nonlinear Von-Karman approach is adopted to acquire the equations of motion.Then,to turn the partial differential equations(PDEs)into ordinary differential equations(ODEs)in the case of equations of motion,the method of Galerkin is employed,followed by the multiple time scale method to solve the resulting equations.The impact of parameters affecting the response of the beam,including the porosity distribution,porosity coefficient,temperature increments,slenderness,thickness,and damping ratios,are explicitly discussed.It is found that the parameters mentioned above affect the bifurcation points and instability of the sandwich porous beams,some of which,including the effect of temperature and porosity distribution,are less noticeable.

Experimental study of 3D printed carbon fibre sandwich structures for lightweight applications

Honeycomb sandwich structures are widely used in lightweight applications.Usually,these structures are subjected to extreme loading conditions,leading to potential failures due to delamination and debonding between the face sheet and the honeycomb core.Therefore,the present study is focused on the mechanical characterisation of honeycomb sandwich structures fabricated using advanced 3D printing technology.The continuous carbon fibres and ONYX-FR matrix materials have been used as raw materials for 3D printing of the specimens needed for various mechanical characterization testing;ONYX-FR is a commercial trade name for flame retardant short carbon fibre filled nylon filaments,used as a reinforcing material in Morkforged 3D printer.Edgewise and flatwise compression tests have been conducted for different configurations of honeycomb sandwich structures,fabricated by varying the face sheet thickness and core cell size,while keeping the core cell thickness and core height constant.Based on these tests,the proposed structure with face sheet thickness of 3.2 mm and a core cell size of 12.7 mm exhibited the highest energy absorption and prevented delamination and debonding failures.Therefore,3D printing technology can also be considered as an alternative method for sandwich structure fabrication.However,detailed parametric studies still need to be conducted to meet various other structural integrity criteria related to the lightweight applications.

Class Imbalanced Problem:Taxonomy,Open Challenges,Applications and State-of-the-Art Solutions

The study of machine learning has revealed that it can unleash new applications in a variety of disciplines.Many limitations limit their expressiveness,and researchers are working to overcome them to fully exploit the power of data-driven machine learning(ML)and deep learning(DL)techniques.The data imbalance presents major hurdles for classification and prediction problems in machine learning,restricting data analytics and acquiring relevant insights in practically all real-world research domains.In visual learning,network information security,failure prediction,digital marketing,healthcare,and a variety of other domains,raw data suffers from a biased data distribution of one class over the other.This article aims to present a taxonomy of the approaches for handling imbalanced data problems and their comparative study on the classification metrics and their application areas.We have explored very recent trends of techniques employed for solutions to class imbalance problems in datasets and have also discussed their limitations.This article has also identified open challenges for further research in the direction of class data imbalance.