Interlocked MXene/rGO aerogel with excellent mechanical stability for a health-monitoring device

Two-dimensional(2D)materials have attracted considerable interest thanks to their unique electronic/physical-chemical characteristics and their potential for use in a large variety of sensing applications.However,few-layered nanosheets tend to agglomerate owing to van der Waals forces,which obstruct internal nanoscale transport channels,resulting in low electrochemical activity and restricting their use for sensing purposes.Here,a hybrid MXene/rGO aerogel with a three-dimensional(3D)interlocked network was fabricated via a freeze-drying method.The porous MXene/rGO aerogel has a lightweight and hierarchical porous architecture,which can be compressed and expanded several times without breaking.Additionally,a flexible pressure sensor that uses the aerogel as the sensitive layer has a wide response range of approximately 0-40 kPa and a considerable response within this range,averaging approximately 61.49 kPa^(-1).The excellent sensing performance endows it with a broad range of applications,including human-computer interfaces and human health monitoring.

Topological Confinement in Reversibly Interlocked Polymer Networks

Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.

Strengthening and toughening styrene-butadiene rubber by mechanically interlocked cross-links

Styrene-butadiene rubber(SBR)is an indispensable material in modern society,and the necessity for enhanced mechanical properties in SBR persists,particularly to withstand the rigors of challenging environmental conditions.To surmount the limitations of conventional cross-linking modes,mechanical bonds stabilized by host-guest recognition are incorporated as the cross-linking points of SBR to form mechanically interlocked networks(MINs).Compared with covalently cross-linked network,the representative MIN exhibits superior mechanical performance in terms of elongation(1392%)and breaking strength(4.6 MPa),whose toughness has surged by 17 times.Dissociation of host-guest recognition and subsequent sliding motion provide an effective energy dissipation mechanism,and the release of hidden length is also beneficial to enhance toughness.Furthermore,the introduction of the rotaxane cross-links made the network more pliable and possess damping and elastic properties,which can return to initial state with one minute rest interval.We aspire that this direct introduction method can serve as a blueprint,offering valuable insights for the enhancement of mechanical properties in conventional commercial polymer materials.

3D interlocked all-textile structured triboelectric pressure sensor for accurately measuring epidermal pulse waves in amphibious environments

The performance degradation and even damage of the e-textiles caused by sweat,water,or submersion during all-weather health monitoring are the main reasons that e-textiles have not been commercialized and routinized so far.Herein,we developed an amphibious,high-performance,air-permeable,and comfortable all-textile triboelectric sensor for continuous and precise measurement of epidermal pulse waves during full-day activities.Based on the principle of preparing gas by acid-base neutralization reaction,a one-piece preparation process of amphibious conductive yarn(ACY)with densely porous structures is proposed.An innovative three-dimensional(3D)interlocking fabric knitted from ACYs(0.6 mm in diameter)and polytetrafluoroethylene yarns exhibit high sensitivity(0.433 V·kPa^(-1)),wide bandwidth(up to 10 Hz),and stability(>30,000 cycles).With these benefits,98.8%agreement was achieved between wrist pulse waves acquired by the sensor and a high-precision laser vibrometer.Furthermore,the polytetrafluoroethylene yarn with good compression resilience provides sufficient mechanical support for the contact separation of the ACYs.Meanwhile,the unique skeletonized design of the 3D interlocking structure can effectively relieve the water pressure on the sensor surface to obtain stable and accurate pulse waves(underwater depth of 5 cm).This achievement represents an important step in improving the practicality of e-textiles and early diagnosis of cardiovascular diseases.

Oriented magnetic liquid metal-filled interlocked bilayer films as multifunctional smart electromagnetic devices

Smart electromagnetic functional devices prepared based on electromagnetic wave responsive materials will provide more convenience for human life in the future.Here,we prepare oriented magnetic liquid metal droplet-filled polydimethylsiloxane films with micropillar array patterned surfaces,and further assemble them into bilayer films with interlocked structures.Once compressed,the increase in conductivity of the film due to the tunneling effect between microarrays and the elongation of liquid metal droplets leads to a rapid increase in electromagnetic interference shielding performance.Accordingly,a tunable electromagnetic interference shielding material with high sensitivity and wide control range is obtained,which has potential applications in electromagnetic wave control systems and intelligent electromagnetic protection systems.Meanwhile,we assemble a strain sensor and a magnetic sensor,which can precisely sense pressure and magnetic field according to changes in electromagnetic signal and electrical signal,respectively.

Rational Design and Synthesis of Interlocked[2]Catenanes Fea-turing Half-Sandwich Cp^(*)Rh/Ir Units and Pyrene-Based Ligands

The construction of interlocked topologies by metal-cation-template methods has been extensively explored.However,construction of these species using template-free chemical self-assembly methods is hard to rationally achieve due to the inherent unpredictability of self-assembly processes.In this work,a strategy to construct interlocked[2]catenanes by coordination-driven template-free self-assembly is demonstrated,whereby combining rigid bidentate ligands with large conjugated-πarea units and building blocks with appropriate lengths facilitated construction of interlocked[2]catenane compounds.Two rigid bidentate ligands,L1 and L2,were chosen to self-assemble with three dinuclear building blocks B1,B2 and B3.Ultimately,the successful construction of three[2]catenanes demonstrated the validity of the strategy.Although[2]catenanes are the simplest of all interlocked topologies,this motif is the basis for constructing more intricate topologies.This successful strategy may therefore lead to construction of other,more intricate topologies in the future.

Applying reticular synthesis to the design of Cu-based MOFs with mechanically interlocked linkers

The concept of“robust dynamics”describes the incorporation of mechanically interlocked molecules(MIMs)into metal-organic framework(MOF)materials such that large amplitude motions(e.g.,rotation or translation of a macrocycle)can occur inside the free volume pore of the MOF.To aid in the preparation of such materials,reticular synthesis was used herein to design rigid molecular building blocks with predetermined ordered structures starting from the well-known MOF NOTT-101.New linkers were synthesized that have a T-shape,based on a triphenylene tetra-carboxylate strut,and their incorporation into Cu(II)-based MOFs was investigated.The single-crystal structures of three new MOFs,UWCM-12(fof),β-UWCM-13(loz),UWCM-14(lil),with naked T-shaped linkers were determined;β-UWCM-13 is the first reported example of the loz topology.A fourth MOF,UWDM-14(lil)is analogous to UWCM-14(lil)but contains a[2]rotaxane linker.Variable-temperature,^(2)H solid-state NMR was used to probe the dynamics of a 24-membered macrocycle threaded onto the MOF skeleton.

An interlocked coordination cage based on aromatic amide ligands

An interlocked M_(4) L_(8) coordination cage was synthesized by coordination-driven self-assembly of palladium(Ⅱ)ions with aromatic amide bidentate ligands.The reaction of the ligand and the metal at 2:1 ratio led to the monomeric M_(2) L_(4) cage as the kinetic product,while the thermodynamic product M_(4) L_(8) cage was obtained by prolongating the reaction.This conve rsion and the interlocked structure was clearly revealed by using~1 H NMR,mass spectrometry and X-ray crystallography.The driving force of interlocking was mainly attributed to the interactions(hydrogen bonding,aromatic stacking and electrostatic interaction)arising from the aptitude of flexibility of the amide ligand.

From Mechanically Interlocked Structures to Host-Guest Chemistry Based on Twisted Dimeric Architectures by Adjusting Space Constraints

Mechanically interlocked molecules(MIMs)and host–guest chemistry have received great attention in the past few decades.However,it remains challenging to design architectures with mechanically interlocked features and construct cavities for guest molecule recognition using similar building blocks.In this study,we designed and constructed a series of novel twisted supramolecular structures by assembling various multitopic terpyridine(tpy)ligands with the same diameter and Zn(II)ions.The obtained complexes exhibited evolutional architectures and showed distinctively different space-constraint effects.Specifically,the assembled dimer SA,SB,and SBH displayed mechanically interlocked phenomena,including[2]catenane and[3]catenane,with an increase in concentration.However,no interlocked structures were observed in complexes SC and SCH constructed by hexatopic tpy ligands due to the significant space constraints.The single-crystal data of complex SCH further proved significant space constraints and illustrated the formation of a relatively closed cavity,which showed excellent host–guest properties for different calixarenes,especially high affinity for calix[6]arene.

Research on Ventilation and Heat Insulation Layer Design of Split-Type Roof Greening Based on Topological Interlocking Principle

In this paper,the roof ventilation and heat insulation layer modules are combined with the roof greening,and each module is assembled through the principle of topological interlocking.The assembly of these modules does not require any rivets or cement mortar,and the structural stability of the overall assembled roof is achieved only through the interlocking and limiting the movements of the interlocked units.The green roof designed in this paper has strong applicability and can be applied to roofs of different shapes.Such a roof can not only meet the aesthetic needs,but also beautify the urban environment and reduce carbon emissions.

Preparation of ultra-fine grain Ni-Al-WC coating with interlocking bonding on austenitic stainless steel by laser clad and friction stir processing

The ultra-fine structured Ni?Al?WC layer with interlocking bonding was fabricated on austenitic stainless steel by combination of laser clad and friction stir processing (FSP). Laser was initially applied to Ni?Al elemental powder preplaced on the austenitic stainless steel substrate to produce a coating for further processing. The as-received coating was subjected to FSP treatment, processed by a rotary tool rod made of WC?Co alloy, to obtain sample for inspection. Microstructure, phase constitutions, hardness and wear property were investigated by methods of scanning electronic microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) microanalysis, and X-ray diffraction (XRD), hardness test alongside with dry sliding wear test. The results show that the severe deformation effect exerted on the specimen resulted in an ultra-fine grain layer of about 100μmin thickness and grain size of 1?2μm. Synergy between introduction of WC particles to the deformation layer and deformation strengthening contributes greatly to the increase in hardness and friction resistance. An interlocking bonding between the coating and matrix which significantly improves bonding strength was formed due to the severe deformation effect.

Verification of SEU resistance in 65 nm high-performance SRAM with dual DICE interleaving and EDAC mitigation strategies

A dual double interlocked storage cell(DICE)interleaving layout static random-access memory(SRAM)is designed and manufactured based on 65 nm bulk complementary metal oxide semiconductor technology.The single event upset(SEU)cross sections of this memory are obtained via heavy ion irradiation with a linear energy transfer(LET)value ranging from 1.7 to 83.4 MeV/(mg/cm^(2)).Experimental results show that the upset threshold(LETth)of a 4 KB block is approximately 6 MeV/(mg/cm^(2)),which is much better than that of a standard unhardened SRAM with an identical technology node.A 1 KB block has a higher LETth of 25 MeV/(mg/cm^(2))owing to the use of the error detection and correction(EDAC)code.For a Ta ion irradiation test with the highest LET value(83.4 MeV/(mg/cm^(2))),the benefit of the EDAC code is reduced significantly because the multi-bit upset proportion in the SEU is increased remarkably.Compared with normal incident ions,the memory exhibits a higher SEU sensitivity in the tilt angle irradiation test.Moreover,the SEU cross section indicates a significant dependence on the data pattern.When comprehensively considering HSPICE simulation results and the sensitive area distributions of the DICE cell,it is shown that the data pattern dependence is primarily associated with the arrangement of sensitive transistor pairs in the layout.Finally,some suggestions are provided to further improve the radiation resistance of the memory.By implementing a particular design at the layout level,the SEU tolerance of the memory is improved significantly at a low area cost.Therefore,the designed 65 nm SRAM is suitable for electronic systems operating in serious radiation environments.

Experimental study on the goaf flow field of the ‘‘U+I” type ventilation system for a comprehensive mechanized mining face

＂U＂ and ＂U＋I＂ type ventilation experiments were performed on a three-dimensional fully mechanized caving face simulation experimental platform. The distribution laws of the pressure field and gas field in the mine goal were obtained. Results show that the flow field in the goaf is generally asymmetric; the location of the gas accumulation area changes with ventilation parameters and can be used as an evaluation indicator to study the air leakage extent in the goal. Hence, drainage pipes buried in the goaf to intensively extract gas can be designed in such gas areas, which can give considerations in both improving gas drainage efficiency and reducing air leakage. By comparing the gas extraction effect of model experiments with that of on-site underground practices, the basic laws are commonly consistent according to comparative analysis. Thus the experimental results can be used to guide the application of underground gas prevent!o_n_and.control..

Interlock可解脱弹簧圈系统在冠状动脉-肺动脉瘘栓塞术中的应用

目的探讨Interlock可解脱弹簧圈系统应用于冠状动脉-肺动脉瘘栓塞术的安全性及有效性。方法回顾性分析2016年12月23日至2017年9月7日于中国医学科学院阜外医院选用Interlock可解脱弹簧圈系统行冠状动脉-肺动脉瘘栓塞术的6例冠状动脉-肺动脉瘘患者临床资料,其中包括男性2例,女性4例。所有患者均常规采用右侧桡动脉入径行冠状动脉造影以明确诊断,沿导管置入并释放Interlock可解脱弹簧圈于瘘管或瘤腔内,栓塞后行选择性冠状动脉造影评价疗效,观察术中及术后有无并发症发生。结果 6例选用Interlock可解脱弹簧圈行冠状动脉-肺动脉瘘栓塞术的患者均手术成功,无血管损伤及心肌梗死等术中并发症发生。有4例合并动脉瘤形成,其中3例应用弹簧圈填塞在动脉瘤体,1例栓塞在动脉瘤近心端瘘管。术中共用Interlock可解脱弹簧圈18枚,其中3枚为钻石型,15枚为普通2D型;弹簧圈直径为2～12 mm,长度为2.3～30 cm;瘘口直径为2～3 mm。即刻行选择性冠状动脉造影,其中3例为完全栓塞,3例有少量残余分流。术后所有患者胸闷、胸痛症状均得以缓解;超声心动图提示无异常血流,X线胸片提示弹簧圈位置、形态良好,心电图检查无新发心律失常或心肌缺血等改变。随访12个月,无心肌梗死、心源性休克、心室颤动、心室扑动、心脏破裂或猝死等主要不良心血管事件发生。结论 Interlock可解脱弹簧圈系统可控性高、安全性好,尤其适用于伴有动脉瘤形成、血管迂曲需要准确定位的冠状动脉-肺动脉瘘患者介入治疗。

Modeling the relationship of land use change and some geophysical indicators for the interlock area of farming and pasturing in China

This paper discusses land-use changes in the interlock area of farming and pasturing (IAFP) in northern China. It presents detailed analyses of land-use features in the IAFP, which are controlled by the macro geomorphic units and geophysical conditions-constraints or advantages. Additionally, it selects some indicators, according to the availability in acquiring and processing their quantitative data, to analyze the canonical correlations between the typical conversion of grassland and geophysical conditions. The preliminary study indicates that the physical conditions are of great advantages to the development of grassland. There exists significant correlation between land use change and some geophysical conditions.

The Supervisory Control System for the HL-2A Neutral Beam Injector

Supervisory control and protection system of the neutral beam injector （NBI） in the HL-2A tokamak is presented. The system is used for a safe coordination of all the main NBI subsystems. Because the system is based on computer networks with its transmission medium of optical fiber, its advantages in high operational stability, reliability, security and flexible functional expandability are clearly shown during the NBI commissioning and heating experiment in HL-2A.

Fault diagnosis method for switch control circuit based on SVM-AdaBoost

In order to realize the fault diagnosis of the control circuit of all-electronic computer interlocking system(ACIS)for railway signals,taking a five-wire switch electronic control module as an research object,we propose a method of selecting the sample set of the basic classifier by roulette method and realizing fault diagnosis by using SVM-AdaBoost.The experimental results show that the proportion of basic classifier samples affects classification accuracy,which reaches the highest when the proportion is 85%.When selecting the sample set of basic classifier by roulette method,the fault diagnosis accuracy is generally higher than that of the maximum weight priority method.When the optimal proportion 85%is taken,the accuracy is highest up to 96.3%.More importantly,this way can better adapt to the critical data and improve the anti-interference ability of the algorithm,and therefore it provides a basis for fault diagnosis of ACIS.

Design and Implementation of Quench Protection in the EAST Cryogenic Control System

An outline of the complete design of the cryogenic system, including the detection of quench signals, the processing flow after a quench and the concrete measures of pressure release for EAST is described in this paper. The hardware and software configurations on DeltaV DCS are illustrated in detail. The results of quench protection testing in cooling experiments are also analyzed.

Effect of aggregate gradation on low temperature performance of asphalt paving mixtures

Low temperature cracking has become one of the important factors that diminish asphalt pavement's ride quality and service life.Especially in cold region,cracking caused by low temperature is the main distress form.This paper discussed the effect of aggregate gradation on the low temperature performance in asphalt paving mixtures.A total of 11 asphalt mixtures with 11 different aggregate gradations and one asphalt binder content were studied.Volumetric properties of the coarse aggregate and asphalt mixtures showed aggregate grading has a significant impact on the degree of aggregate interlock in asphalt mixtures.A trend is existed in the low temperature performance with the change of gradation.With the aid of mathematic statistics,it indicates gradation affects the low temperature performance significantly.The findings also indicate the relationship between the degree of aggregate interlock in asphalt mixtures and the low temperature performance:With the stone-to-stone contact developed,the mixture has a high energy to resist contract and deformation at low temperature.The properties of fine aggregate and asphalt play an important part in resisting low temperature cracking in floating structure.But it provides lower energy to resist low temperature cracking compared to the skeleton structure.

Comparative study of intertrochanteric fracture fixation using proximal femoral nail with and without distal interlocking screws

BACKGROUND Intertrochanteric(IT)fracture is one of the most common fractures seen in an orthopaedic practice.Proximal femoral nailing(PFN)is a common modality of fixing IT femur fracture.We retrospectively studied whether a PFN with two proximal lag screws can be done without distal interlocking screws in the 31-A1 and 31-A2 fracture patterns according to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association(AO/OTA)guidelines for IT femur fractures.AIM To compare the outcomes of IT fractures(AO/OTA 31-A1 and 31-A2)treated by PFN with and without distal interlocking screws.METHODS We carried out a retrospective study of 140 patients in a tertiary care centre who had AO/OTA type 31-A1 and 31-A2 IT fractures.We divided the patients into two groups,in which one of the groups received distal interlocking screws(group 1)and the other group did not(group 2).The subjects were followed up for a mean period of 14 mo and assessed for radiological union time,fracture site collapse,mechanical stability of implant,and complications associated with the PFN with distal interlocking and without distal interlocking.Then,the results were compared.RESULTS PFN without distal interlocking screws has several advantages and gives better results over PFN with distal interlocking screws in the AO/OTA 31-A2 fracture pattern.However,similar results were observed in both groups with the fracture pattern AO/OTA 31-A1.In patients with fracture pattern AO/OTA 31-A2 treated by PFN without distal interlocking screws,there were minimal proximal lockrelated complications and no risk of distal interlock-related complications.The operative time,IITV radiation time and time to radiological union were reduced.These patients also had better rotational alignment of the proximal femur,and the anatomy of the proximal femur was well maintained.It was also noted that in the cases where distal interlocking was performed,there was a gradual decrease in neck shaft angle,which led to varus collapse and failure of bone-implant construct in 21.40%.CONCLUSION In fracture pattern AO/OTA 31-A2,PFN without distal interlocking had better results and less complications than PFN with distal interlocking.