Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This impo...Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This imposes a reevaluation of the drawing procedure for constructing field curves with a constant field values around multiple parallel electrical conducting wires. To achieve this, we employ methods akin to those used for creating contours on topographical maps, ensuring a consistent numerical field value along the entire length of the field curves. Subsequent calculations will be conducted for scenarios where wires are not parallel.展开更多
To study the evolution of nanoparticles during Al wire electrical explosion,a nanoparticle formation model that considered layered motion was developed,and an experimental system was set up to carry out electrical exp...To study the evolution of nanoparticles during Al wire electrical explosion,a nanoparticle formation model that considered layered motion was developed,and an experimental system was set up to carry out electrical explosion experiments using 0.1 mm and 0.2 mm Al wires.The characteristic parameters and evolution process during the formation of nanoparticles were calculated and analyzed.The results show that the maximum velocities of the innermost and outermost layers are about 1200 m·s-1and 1600 m·s-1,and the velocity of the middle layer is about 1400 m·s-1,respectively.Most of the nanoparticles are formed in the temperature range of2600 K-2500 K.The characteristic temperature for the formation of Al nanoparticles is~2520K,which is also the characteristic temperature of other parameters.The size distribution range of the formed nanoparticles is 18 to 110 nm,and most of them are around 22 nm.The variation of saturated vapor pressure determines the temperature distribution range of particle nucleation.There is a minimum critical diameter of particles(~25 nm);particles smaller than the critical diameter can grow into larger particles during surface growth.Particle motion has an effect on the surface growth and aggregation process of particles,and also on the distribution area of larger-diameter particles.The simulation results are in good agreement with the experiments.We provide a method to estimate the size and distribution of nanoparticles,which is of great significance to understand the formation process of particles during the evolution of wire electrical explosion.展开更多
Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance(GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricate...Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance(GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricated by using electroless deposition methods and the magnetoimpedance properties were investigated. The maximum GMI ratio of 114% was acquired at 60 MHz in the composite wires with a ferromagnetic core, whereas, 116% of maximum GMI ratio was found in the composite wires with a conductive core at low frequency of 600 k Hz. These results exhibit that the GMI ratio reaches the maximum when magnetoresistance ratio ?R/R and magnetoinductance ratio ?X/X make the comparative contributions to the total magnetoimpedance(MI). The obvious GMI effect obtained in the composite wires with conductive core frequency may provide a candidate for applications in magnetic sensors, especially at low frequencies.展开更多
Objective Supracondylar humerus fractures are the most frequent fractures of the paediatric elbow.The present study introduced a modified surgical procedure for treatment of supracondylar humerus fractures in children...Objective Supracondylar humerus fractures are the most frequent fractures of the paediatric elbow.The present study introduced a modified surgical procedure for treatment of supracondylar humerus fractures in children.Methods From February 2015 to August 2019,73 patients with Gartland’s type II and III supracondylar fractures were treated with this modified method.Totally,68 of all patients were followed up for 3–12 months(mean 8.25 months).The evaluation results included fracture nonunion,ulnar nerve injury,pin track infection,carrying angle and elbow joint Flynn score.Results The results showed that bone union was observed in all children,one case had an iatrogenic ulnar nerve injury,and the symptoms were completely relieved in 4 months after removing of the medial-side pin.All children had no cubitus varus deformity and no pin track infection,and the rate of satisfactory results according to Flynn’s criteria score was 100%.Conclusion The modified closed reduction and Kirschner wires internal fixation could effectively reduce the rate of open reduction,the risk of iatrogenic ulnar nerve injury,and the incidence of cubitus varus deformity in treatment of supracondylar humerus fractures in children.展开更多
The cyclotron resonance of magnetopolaron in quantum well wires (QWWs) have been studied withthe use of variational solutions to the effective mass equation. The results show that both the abso-lute value of the elect...The cyclotron resonance of magnetopolaron in quantum well wires (QWWs) have been studied withthe use of variational solutions to the effective mass equation. The results show that both the abso-lute value of the electron-phonon interaction energy and the cyclotron resonance frequency de-crease with the increase of the sizes of QWWs, and also that the cyclotron resonance frequency in-creases with the external magnetic field.展开更多
Epoxy resin/polytetrafluorethylene coating TiNi arch wires have been fabricated by dipping method.The vickers hardness,adhesion force,the maximum static friction force and biocompatibility also have been examined.The ...Epoxy resin/polytetrafluorethylene coating TiNi arch wires have been fabricated by dipping method.The vickers hardness,adhesion force,the maximum static friction force and biocompatibility also have been examined.The results show that the vickers hardness,adhesion force and the maximum static friction force increase with the increase of the content of epoxy resin.And the epoxy resin/polytetrafluorethylene coatings are nontoxic.展开更多
During the past several years, giant magneto-impedance effect (GMI) in amorphous wires has generated growing interest in the science community because of their applications in sensors. The giant magneto-impedance effe...During the past several years, giant magneto-impedance effect (GMI) in amorphous wires has generated growing interest in the science community because of their applications in sensors. The giant magneto-impedance effect in Co71.8Fe4.9Nb0.8Si7.5B15 amorphous glass-covered wires (AGCW) consists of strong changes in the high frequency impedance with a small DC magnetic field. When f=1 MHz, there is no GMI effect due to the fact that the magnetic penetration depth is higher than their radius. As the frequency increases, the GMI effect becomes important in both the glass-covered wire and the wire after glass removal. Field dependence of the impedance has a similar behaviour to the AGCW ones, when a tensile stress is applied to the wire without glass cover.展开更多
Based on classic theory of elastic rod,the warp-knitted loop geometry in plane is independent of yarn properties,while there is a certain gap between the geometrical model and the actual fabrics.According to this prob...Based on classic theory of elastic rod,the warp-knitted loop geometry in plane is independent of yarn properties,while there is a certain gap between the geometrical model and the actual fabrics.According to this problem,further analysis of loop geometry is done based on the theory of elastic rod with theoretical calculation and experiments.The theoretical analysis found that the distance between the contacted points at the loop root affected the loop geometry,and the distance was affected by the ratio of bending rigidity and the friction between yarns.The experiments,forming simple loop by taking the yarn as an elastic rod,found that the bending rigidity affected the loop geometry.Then the relationships between warp-knitted loop geometry in plane of metallic fabrics and wires properties were studied.The results show that metallic fabrics are more suitable for the theory of elastic rod;the friction and bending rigidity of wire yarns affect the loop geometry in plane.Also,the elongation of yarn affects the loop geometry in the actual warp-knitted fabric.展开更多
Low dimensional materials are suitable candidates applying in next-generation high-performance electronic,optoelectronic,and energy storage devices because of their uniquely physical and chemical properties.In particu...Low dimensional materials are suitable candidates applying in next-generation high-performance electronic,optoelectronic,and energy storage devices because of their uniquely physical and chemical properties.In particular,one-dimensional(1D)atomic wires(AWs)exfoliating from 1D van der Waals(vdW)bulks are more promising in next generation nanometer(nm)even sub-nm device applications owing to their width of few-atoms scale and free dandling bonds states.Although several 1D AWs have been experimentally prepared,few 1D AW candidates could be practically applied in devices owing to lack of enough suitable 1D AWs.Herein,367 kinds of 1D AWs have been screened and the corresponding computational database including structures,electronic structures,magnetic states,and stabilities of these 1D AWs has been organized and established.Among these systems,unary and binary 1D AWs with relatively small exfoliation energy are thermodynamically stable and theoretically feasible to be exfoliated.More significantly,rich quantum states emerge,such as 1D semiconductors,1D metals,1D semimetals,and 1D magnetism.This database will offer an ideal platform to further explore exotic quantum states and exploit practical device applications using 1D materials.The database are openly available at http://www.dx.doi.org/10.11922/sciencedb.j00113.00004.展开更多
The characteristic of near-surface microstructure and its effects on the torsion performance of cold-drawn pearlitic steel wires for bridge cables were investigated by focused ion beam-scanning electron microscope,tra...The characteristic of near-surface microstructure and its effects on the torsion performance of cold-drawn pearlitic steel wires for bridge cables were investigated by focused ion beam-scanning electron microscope,transmission electron microscopy and differential scanning calorimetry.The samples with similar tensile strength before and after hot-dip galvanizing process are,respectively,characterized as delaminated and non-delaminated in torsion test which indicates that the tensile strength is independent of the toughness value(i e,reduction area and torsion ability).It is interesting to find that there exists submicron granular ferrite on near-surface of the wires,which can be attributed to dislocation rearrangement and sub-grains rotation during cold drawing and hot-dip galvanizing process.And their distribution can suggest homogeneousness of deformation degree to a certain extent:the closer to the surface of their distribution,the more homogeneous deformation of the wires.There is a close relationship between the thermal stability of the cementite layer and distribution of granular ferrite:differential scanning calorimetry(DSC)analysis shows that the sample is accompanied by submicron granular ferrite which is located closer to the surface has higher thermal stability under galvanizing temperature(450°C).A new mechanism of the torsion delamination of pearlitic steel wires is discussed in terms of the thermal stability of the cementite layer and distribution of granular ferrite.展开更多
Rechargeable alkaline batteries(RABs)have received remarkable attention in the past decade for their high energy,low cost,safe operation,facile manufacture,and ecofriendly nature.To date,expensive electrode materials ...Rechargeable alkaline batteries(RABs)have received remarkable attention in the past decade for their high energy,low cost,safe operation,facile manufacture,and ecofriendly nature.To date,expensive electrode materials and current collectors were predominantly applied for RABs,which have limited their real-world efficacy.In the present work,we propose a scalable process to utilize electronic waste(e-waste)Cu wires as a cost-effective current collector for high-energy wire-type RABs.Initially,the vertically aligned CuO nanowires were prepared over the waste Cu wires via in situ alkaline corrosion.Then,both atomiclayer-deposited NiO and NiCo-hydroxide were applied to the CuO nanowires to form a uniform dendritic-structured NiCo-hydroxide/NiO/CuO/Cu electrode.When the prepared dendritic-structured electrode was applied to the RAB,it showed excellent electrochemical features,namely high-energy-density(82.42 Wh kg−1),excellent specific capacity(219 mAh g−1),and long-term cycling stability(94%capacity retention over 5000 cycles).The presented approach and material meet the requirements of a cost-effective,abundant,and highly efficient electrode for advanced eco-friendly RABs.More importantly,the present method provides an efficient path to recycle e-waste for value-added energy storage applications.展开更多
Class III malocclusion associated with posterior crossbite, anterior open bite pattern with asymmetric occlusion in adults can be a challenging orthodontic problem, especially for the nonsurgical treatment. Skeletal C...Class III malocclusion associated with posterior crossbite, anterior open bite pattern with asymmetric occlusion in adults can be a challenging orthodontic problem, especially for the nonsurgical treatment. Skeletal Class III anteroposterior discrepancies in adult patients are generally managed either by surgical-orthodontic treatment or by orthodontic camouflage through dentoalveolar compensation. Although correction with surgery may be the most effective and stable way, many patients refuse surgical treatment plan because of the costs and traumas it may bring. This case report describes the successful use of TADs with expansion auxiliary wire to treat a 24-year-old man with skeletal class III malocclusion, posterior crossbite, anterior open-bite and asymmetric occlusion, mild upper and lower dental spacing and a chief manifestation of anterior crossbite. The patient refused surgery. A treatment plan was formulated consisting of using auxiliary expansion wire to expand the maxillary arch, 8 mm mini-screws between the roots of the mandibular canines and first premolars, preadjusted edgewise brackets to align the teeth, Class III and asymmetric elastics to correct the canines, premolars, and molars relationship and midline deviation, reverse curve of the nickel-titanium wire combined with anterior vertical elastics to intrude molars and correct the anterior open-bite. In this case, without going through surgery, the posterior cross-bite was corrected, and ideal overjet and overbite relationships, midline coincidence and functional occlusion were all achieved. Satisfactory occlusal, functional, esthetic and stable results were obtained.展开更多
Icing of wires is a product of rain, fog, and freezing rain, and is a common meteorological disaster in winter in Guizhou Province of China. It is extremely harmful to facilities such as power transmission and communi...Icing of wires is a product of rain, fog, and freezing rain, and is a common meteorological disaster in winter in Guizhou Province of China. It is extremely harmful to facilities such as power transmission and communication lines, and has caused huge economic loss up to 48.9566 billion dollars a year. Based on the meteorological records of Guizhou from 1967, we analyze the meteorological characteristics during the icing of wires, and obtain the temperature, wind speed and direction conditions of the ice accident. The icing of wires is carried out by supercooling raindrops, freezing of the clouds, freezing and spreading on the wires. Different types of supercooled raindrops and cloud freezing and freezing processes will form different types of ice accretion;wind direction and wind speed will affect the growth of ice accretion by changing the speed of sub-cooling raindrops and cloud falling. The weight of rain-type ice accretion is between 24 and 152 g, and the weight of smog-type ice is between 40 - 76 g. The average ice density of these two places can be calculated to be 0.2 - 0.5 g/cm3. The longer the icing of wires, the higher the ice disaster rate.展开更多
To assess, in vitro, the cellular viability in a murine macrophage cell line J774 with 9 different orthodontic wires and to evaluate the effects of its NO production. To assess cellular viability by MTT: 3-(4,5-dimeth...To assess, in vitro, the cellular viability in a murine macrophage cell line J774 with 9 different orthodontic wires and to evaluate the effects of its NO production. To assess cellular viability by MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide assay in the cell line J774 with 9 different orthodontic wires and quantify NO production by these macrophages. Cell cultures were evaluated at 24, 48 and 72 hours. There was no significant difference of the means of cellular viability between the control and the group of wires in the respective time intervals. In the comparison with the control group, there was significant difference in the NO production in groups 1, 6, and 9 at 24 hours interval. Group 8 showed significant difference in relation to the control group at final time interval. Cellular viability in all groups was higher at the final time interval than at the initial time interval. This increase was significant in the control group. In the material groups, the final mean of cellular viability at 72 hours showed no significant difference when compared with the control group. NO production in all groups was higher at the final time interval than at the initial time interval. This increase was significant in the control group. In the material groups, the final mean of NO production at 72 hours was only significant in group 8 (betatitanium) when compared with the control group.展开更多
The Kirschner wires (K-wires) are stiff and straight wires made of smooth stainless steel. These are used in surgery to aid in repairing the process of a fractured bone. In forefoot elective surgeries, these pins are ...The Kirschner wires (K-wires) are stiff and straight wires made of smooth stainless steel. These are used in surgery to aid in repairing the process of a fractured bone. In forefoot elective surgeries, these pins are mostly used for fixation of the phalangeal or metatarsal area. These wires are usually either buried or exposed, The exposed wires do not require another operation to remove them and are generally preferred. In using the forefoot surgery history of a single surgeon which was taken for 3 years<span>.</span><span> The purpose of this study is to evaluate the occurrence of infections following elective surgeries of the forefoot that were fixed using k-pins and to indicate an effective treatment option for resolving the infection. The inclusion criteria set for this study was to remove any patient having any disease except for diabetes. Moreover, the age limit was set to be 18</span><span> </span><span>-</span><span> </span><span>44, making a final sample of 50 people, prescribed prophylactic antibiotics or early removal of k-pins, where necessary. The researcher recorded demographic and biological data from the patients such as age, BMI, and smoking status were recorded. The researcher conducted a Univariate analysis via a Chi-square test. 50</span><b><span> </span></b><span>Patients (82 K-wires) were analyzed. Results showed that surgery type, BMI, and smoking were three variables that affect the infection growth significantly while diabetes and type of cleaning disinfectant had marginal effects. Further study is required to clarify the best treatments in this area, as the treatment option antibiotics have nearly similar results.</span>展开更多
Cyanopolyynes (H[C≡C]n-CN or HC2n+1N, where n = 1, 2, 3, …, n) are commonly observed in the interstellar medium (ISM) as well as in the envelopes of carbon-rich stars. These linear molecular structures can be well d...Cyanopolyynes (H[C≡C]n-CN or HC2n+1N, where n = 1, 2, 3, …, n) are commonly observed in the interstellar medium (ISM) as well as in the envelopes of carbon-rich stars. These linear molecular structures can be well described with a one-dimensional conduction model, which considers the scattering processes of electrons through the charge transfer conduction bridge of the H[C≡C]n-molecular wire containing the CN group as an electron-acceptor terminal unit. Therefore, our results using this model enable a better understanding of the longest molecules observed in interstellar space and provide new insight into why these particular cyanopolyynes reach a maximum length, such as is observed from astronomical experimental spectral data and cosmological chemical models. Dipole moments and geometrical parameters of these cyanopolyynes were obtained from ab initio molecular orbital calculations using the restricted Hartree-Fock approach and 6-311G* basis set, in order to obtain the inner resistance as a new parameter of chemical reaction feasibility for this molecular series. Using this last molecular parameter, we have been able to analyze the possibility of identifying long molecular species that can be found under local thermodynamic equilibrium in some ISM such us HC25H, HC27H, and HC29N, which have not been observed at present.展开更多
We present a theoretical investigation of the influence of photo-excitation and spin wave scattering on magnetization of the (Ga,Mn)As diluted magnetic semiconductor (DMS) quantum wires (QWRs) and quantum wells (QWs)....We present a theoretical investigation of the influence of photo-excitation and spin wave scattering on magnetization of the (Ga,Mn)As diluted magnetic semiconductor (DMS) quantum wires (QWRs) and quantum wells (QWs). Double time temperature dependent Green’s function formalism is used for the description of dispersion and spectral density of the systems. Our analysis indicates that spin wave scattering plays an influential role in magnetism of both systems while application of light is insignificant in quantum wells. In the absence of spin wave scattering and at sufficiently low temperatures, a result corresponding to the specific heat of dominating electronic contributions in metals is obtained in QWs. In QWRs, however, this magnetic property is found to vary with T1/2 and α2T1/2 so that light matter coupling has a leading effect on lower temperatures, where α is the light matter coupling factor and T is the temperature.展开更多
In this study, the mechanical properties of tungsten-rhenium wires with nanofibrous microstructure were investigated at both room temperature(RT) and 800?C. The strengthening mechanism associated to the nanofibrous mi...In this study, the mechanical properties of tungsten-rhenium wires with nanofibrous microstructure were investigated at both room temperature(RT) and 800?C. The strengthening mechanism associated to the nanofibrous microstructure was discussed. The results showed that the tungsten-rhenium wires with nanofibrous grains exhibited a very high tensile strength reaching values of 3.5 GPa and 4.4 GPa for the coarse(grains diameter of 240 nm) and fine(grains diameter of 80 nm) wires, respectively. With increasing the temperature from RT to 800?C, the tensile strength decreased slightly but still held high values(1.8 GPa and 3.8 GPa). All the fracture surfaces exhibited apparent necking and characteristics of spear-edge shaped fracture surface, indicating excellent ductility of the wires. A model of the strengthening mechanism of these tungsten-rhenium wires was proposed.展开更多
The effect of different regimes of heat treatment on the tensile strength of SiC coatedcomposite of C fibers reinforced Al wires has been investigated.Their tensile strengthmay increase under treatment either at 500℃...The effect of different regimes of heat treatment on the tensile strength of SiC coatedcomposite of C fibers reinforced Al wires has been investigated.Their tensile strengthmay increase under treatment either at 500℃ for 2h or 550℃ for 1h,but decreaseover 600℃.After the strength tests of extracted fibers from composite wires,theSiC coating is an excellent protection to C fibers.EPMA and EDAX showed that theC/Al interface of the composite wires is stable under treatment below 600℃,butunstable at展开更多
文摘Building on a new model proposed recently for calculating constant electro-magnetic field values, the present article explores the electro-magnetic field configuration generated by parallel electrical wires. This imposes a reevaluation of the drawing procedure for constructing field curves with a constant field values around multiple parallel electrical conducting wires. To achieve this, we employ methods akin to those used for creating contours on topographical maps, ensuring a consistent numerical field value along the entire length of the field curves. Subsequent calculations will be conducted for scenarios where wires are not parallel.
文摘To study the evolution of nanoparticles during Al wire electrical explosion,a nanoparticle formation model that considered layered motion was developed,and an experimental system was set up to carry out electrical explosion experiments using 0.1 mm and 0.2 mm Al wires.The characteristic parameters and evolution process during the formation of nanoparticles were calculated and analyzed.The results show that the maximum velocities of the innermost and outermost layers are about 1200 m·s-1and 1600 m·s-1,and the velocity of the middle layer is about 1400 m·s-1,respectively.Most of the nanoparticles are formed in the temperature range of2600 K-2500 K.The characteristic temperature for the formation of Al nanoparticles is~2520K,which is also the characteristic temperature of other parameters.The size distribution range of the formed nanoparticles is 18 to 110 nm,and most of them are around 22 nm.The variation of saturated vapor pressure determines the temperature distribution range of particle nucleation.There is a minimum critical diameter of particles(~25 nm);particles smaller than the critical diameter can grow into larger particles during surface growth.Particle motion has an effect on the surface growth and aggregation process of particles,and also on the distribution area of larger-diameter particles.The simulation results are in good agreement with the experiments.We provide a method to estimate the size and distribution of nanoparticles,which is of great significance to understand the formation process of particles during the evolution of wire electrical explosion.
基金Shanghai Automotive Science and Technology Development Foundation (SAISTDF/12-06)East China Normal University Program (78210142, 78210183)Shanghai Ocean University Program (A-2600-10-0054, B-5406-12-0012)
文摘Composite structure materials were potential sensing elements for magnetic sensors due to Giant magnetoimpedance(GMI) effect. Two kinds of composite wires with different magnetic/non-magnetic structures were fabricated by using electroless deposition methods and the magnetoimpedance properties were investigated. The maximum GMI ratio of 114% was acquired at 60 MHz in the composite wires with a ferromagnetic core, whereas, 116% of maximum GMI ratio was found in the composite wires with a conductive core at low frequency of 600 k Hz. These results exhibit that the GMI ratio reaches the maximum when magnetoresistance ratio ?R/R and magnetoinductance ratio ?X/X make the comparative contributions to the total magnetoimpedance(MI). The obvious GMI effect obtained in the composite wires with conductive core frequency may provide a candidate for applications in magnetic sensors, especially at low frequencies.
基金supported by Program of the National Natural Science Foundation of China(No.82074233)Scientific Research Foundation for Advanced Talents,Xiang’an Hospital of Xiamen University(No.PM201809170009).
文摘Objective Supracondylar humerus fractures are the most frequent fractures of the paediatric elbow.The present study introduced a modified surgical procedure for treatment of supracondylar humerus fractures in children.Methods From February 2015 to August 2019,73 patients with Gartland’s type II and III supracondylar fractures were treated with this modified method.Totally,68 of all patients were followed up for 3–12 months(mean 8.25 months).The evaluation results included fracture nonunion,ulnar nerve injury,pin track infection,carrying angle and elbow joint Flynn score.Results The results showed that bone union was observed in all children,one case had an iatrogenic ulnar nerve injury,and the symptoms were completely relieved in 4 months after removing of the medial-side pin.All children had no cubitus varus deformity and no pin track infection,and the rate of satisfactory results according to Flynn’s criteria score was 100%.Conclusion The modified closed reduction and Kirschner wires internal fixation could effectively reduce the rate of open reduction,the risk of iatrogenic ulnar nerve injury,and the incidence of cubitus varus deformity in treatment of supracondylar humerus fractures in children.
文摘The cyclotron resonance of magnetopolaron in quantum well wires (QWWs) have been studied withthe use of variational solutions to the effective mass equation. The results show that both the abso-lute value of the electron-phonon interaction energy and the cyclotron resonance frequency de-crease with the increase of the sizes of QWWs, and also that the cyclotron resonance frequency in-creases with the external magnetic field.
文摘Epoxy resin/polytetrafluorethylene coating TiNi arch wires have been fabricated by dipping method.The vickers hardness,adhesion force,the maximum static friction force and biocompatibility also have been examined.The results show that the vickers hardness,adhesion force and the maximum static friction force increase with the increase of the content of epoxy resin.And the epoxy resin/polytetrafluorethylene coatings are nontoxic.
基金This work was financially supported by the National High-Tech Research and Development Program (No. 2002AA302601) and the National Key Technologies Research and Development Program (No. 2004BA310A51).
文摘During the past several years, giant magneto-impedance effect (GMI) in amorphous wires has generated growing interest in the science community because of their applications in sensors. The giant magneto-impedance effect in Co71.8Fe4.9Nb0.8Si7.5B15 amorphous glass-covered wires (AGCW) consists of strong changes in the high frequency impedance with a small DC magnetic field. When f=1 MHz, there is no GMI effect due to the fact that the magnetic penetration depth is higher than their radius. As the frequency increases, the GMI effect becomes important in both the glass-covered wire and the wire after glass removal. Field dependence of the impedance has a similar behaviour to the AGCW ones, when a tensile stress is applied to the wire without glass cover.
基金Young and Middle-aged Teacher's Education and Research of Fujian Province,China(No.JA15405)the Excellent Academic Leaders Project of Shanghai Municipal Science and Technology Commission,China(No.12XD1400400)+2 种基金the Natural Science Foundation of Shanghai Municipal Science and Technology Commission,China(No.13ZR1400500)the Fundamental Research Funds for the Central Universities,China(No.13D110126)National Innovation Experiment Program for University Students,China(No.131025501)
文摘Based on classic theory of elastic rod,the warp-knitted loop geometry in plane is independent of yarn properties,while there is a certain gap between the geometrical model and the actual fabrics.According to this problem,further analysis of loop geometry is done based on the theory of elastic rod with theoretical calculation and experiments.The theoretical analysis found that the distance between the contacted points at the loop root affected the loop geometry,and the distance was affected by the ratio of bending rigidity and the friction between yarns.The experiments,forming simple loop by taking the yarn as an elastic rod,found that the bending rigidity affected the loop geometry.Then the relationships between warp-knitted loop geometry in plane of metallic fabrics and wires properties were studied.The results show that metallic fabrics are more suitable for the theory of elastic rod;the friction and bending rigidity of wire yarns affect the loop geometry in plane.Also,the elongation of yarn affects the loop geometry in the actual warp-knitted fabric.
基金the National Key Research and Development Program of China(Grant No.2017YFE0129000)the National Natural Science Foundation of China(Grant Nos.51871121,11874223,and 11404172).
文摘Low dimensional materials are suitable candidates applying in next-generation high-performance electronic,optoelectronic,and energy storage devices because of their uniquely physical and chemical properties.In particular,one-dimensional(1D)atomic wires(AWs)exfoliating from 1D van der Waals(vdW)bulks are more promising in next generation nanometer(nm)even sub-nm device applications owing to their width of few-atoms scale and free dandling bonds states.Although several 1D AWs have been experimentally prepared,few 1D AW candidates could be practically applied in devices owing to lack of enough suitable 1D AWs.Herein,367 kinds of 1D AWs have been screened and the corresponding computational database including structures,electronic structures,magnetic states,and stabilities of these 1D AWs has been organized and established.Among these systems,unary and binary 1D AWs with relatively small exfoliation energy are thermodynamically stable and theoretically feasible to be exfoliated.More significantly,rich quantum states emerge,such as 1D semiconductors,1D metals,1D semimetals,and 1D magnetism.This database will offer an ideal platform to further explore exotic quantum states and exploit practical device applications using 1D materials.The database are openly available at http://www.dx.doi.org/10.11922/sciencedb.j00113.00004.
基金Funded by the National Key R&D Program of China(No.2017YFB0304801)。
文摘The characteristic of near-surface microstructure and its effects on the torsion performance of cold-drawn pearlitic steel wires for bridge cables were investigated by focused ion beam-scanning electron microscope,transmission electron microscopy and differential scanning calorimetry.The samples with similar tensile strength before and after hot-dip galvanizing process are,respectively,characterized as delaminated and non-delaminated in torsion test which indicates that the tensile strength is independent of the toughness value(i e,reduction area and torsion ability).It is interesting to find that there exists submicron granular ferrite on near-surface of the wires,which can be attributed to dislocation rearrangement and sub-grains rotation during cold drawing and hot-dip galvanizing process.And their distribution can suggest homogeneousness of deformation degree to a certain extent:the closer to the surface of their distribution,the more homogeneous deformation of the wires.There is a close relationship between the thermal stability of the cementite layer and distribution of granular ferrite:differential scanning calorimetry(DSC)analysis shows that the sample is accompanied by submicron granular ferrite which is located closer to the surface has higher thermal stability under galvanizing temperature(450°C).A new mechanism of the torsion delamination of pearlitic steel wires is discussed in terms of the thermal stability of the cementite layer and distribution of granular ferrite.
基金supported by the National Research Foundation of Korea (NRF-2017R1E1A1A03070930)
文摘Rechargeable alkaline batteries(RABs)have received remarkable attention in the past decade for their high energy,low cost,safe operation,facile manufacture,and ecofriendly nature.To date,expensive electrode materials and current collectors were predominantly applied for RABs,which have limited their real-world efficacy.In the present work,we propose a scalable process to utilize electronic waste(e-waste)Cu wires as a cost-effective current collector for high-energy wire-type RABs.Initially,the vertically aligned CuO nanowires were prepared over the waste Cu wires via in situ alkaline corrosion.Then,both atomiclayer-deposited NiO and NiCo-hydroxide were applied to the CuO nanowires to form a uniform dendritic-structured NiCo-hydroxide/NiO/CuO/Cu electrode.When the prepared dendritic-structured electrode was applied to the RAB,it showed excellent electrochemical features,namely high-energy-density(82.42 Wh kg−1),excellent specific capacity(219 mAh g−1),and long-term cycling stability(94%capacity retention over 5000 cycles).The presented approach and material meet the requirements of a cost-effective,abundant,and highly efficient electrode for advanced eco-friendly RABs.More importantly,the present method provides an efficient path to recycle e-waste for value-added energy storage applications.
文摘Class III malocclusion associated with posterior crossbite, anterior open bite pattern with asymmetric occlusion in adults can be a challenging orthodontic problem, especially for the nonsurgical treatment. Skeletal Class III anteroposterior discrepancies in adult patients are generally managed either by surgical-orthodontic treatment or by orthodontic camouflage through dentoalveolar compensation. Although correction with surgery may be the most effective and stable way, many patients refuse surgical treatment plan because of the costs and traumas it may bring. This case report describes the successful use of TADs with expansion auxiliary wire to treat a 24-year-old man with skeletal class III malocclusion, posterior crossbite, anterior open-bite and asymmetric occlusion, mild upper and lower dental spacing and a chief manifestation of anterior crossbite. The patient refused surgery. A treatment plan was formulated consisting of using auxiliary expansion wire to expand the maxillary arch, 8 mm mini-screws between the roots of the mandibular canines and first premolars, preadjusted edgewise brackets to align the teeth, Class III and asymmetric elastics to correct the canines, premolars, and molars relationship and midline deviation, reverse curve of the nickel-titanium wire combined with anterior vertical elastics to intrude molars and correct the anterior open-bite. In this case, without going through surgery, the posterior cross-bite was corrected, and ideal overjet and overbite relationships, midline coincidence and functional occlusion were all achieved. Satisfactory occlusal, functional, esthetic and stable results were obtained.
文摘Icing of wires is a product of rain, fog, and freezing rain, and is a common meteorological disaster in winter in Guizhou Province of China. It is extremely harmful to facilities such as power transmission and communication lines, and has caused huge economic loss up to 48.9566 billion dollars a year. Based on the meteorological records of Guizhou from 1967, we analyze the meteorological characteristics during the icing of wires, and obtain the temperature, wind speed and direction conditions of the ice accident. The icing of wires is carried out by supercooling raindrops, freezing of the clouds, freezing and spreading on the wires. Different types of supercooled raindrops and cloud freezing and freezing processes will form different types of ice accretion;wind direction and wind speed will affect the growth of ice accretion by changing the speed of sub-cooling raindrops and cloud falling. The weight of rain-type ice accretion is between 24 and 152 g, and the weight of smog-type ice is between 40 - 76 g. The average ice density of these two places can be calculated to be 0.2 - 0.5 g/cm3. The longer the icing of wires, the higher the ice disaster rate.
文摘To assess, in vitro, the cellular viability in a murine macrophage cell line J774 with 9 different orthodontic wires and to evaluate the effects of its NO production. To assess cellular viability by MTT: 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide assay in the cell line J774 with 9 different orthodontic wires and quantify NO production by these macrophages. Cell cultures were evaluated at 24, 48 and 72 hours. There was no significant difference of the means of cellular viability between the control and the group of wires in the respective time intervals. In the comparison with the control group, there was significant difference in the NO production in groups 1, 6, and 9 at 24 hours interval. Group 8 showed significant difference in relation to the control group at final time interval. Cellular viability in all groups was higher at the final time interval than at the initial time interval. This increase was significant in the control group. In the material groups, the final mean of cellular viability at 72 hours showed no significant difference when compared with the control group. NO production in all groups was higher at the final time interval than at the initial time interval. This increase was significant in the control group. In the material groups, the final mean of NO production at 72 hours was only significant in group 8 (betatitanium) when compared with the control group.
文摘The Kirschner wires (K-wires) are stiff and straight wires made of smooth stainless steel. These are used in surgery to aid in repairing the process of a fractured bone. In forefoot elective surgeries, these pins are mostly used for fixation of the phalangeal or metatarsal area. These wires are usually either buried or exposed, The exposed wires do not require another operation to remove them and are generally preferred. In using the forefoot surgery history of a single surgeon which was taken for 3 years<span>.</span><span> The purpose of this study is to evaluate the occurrence of infections following elective surgeries of the forefoot that were fixed using k-pins and to indicate an effective treatment option for resolving the infection. The inclusion criteria set for this study was to remove any patient having any disease except for diabetes. Moreover, the age limit was set to be 18</span><span> </span><span>-</span><span> </span><span>44, making a final sample of 50 people, prescribed prophylactic antibiotics or early removal of k-pins, where necessary. The researcher recorded demographic and biological data from the patients such as age, BMI, and smoking status were recorded. The researcher conducted a Univariate analysis via a Chi-square test. 50</span><b><span> </span></b><span>Patients (82 K-wires) were analyzed. Results showed that surgery type, BMI, and smoking were three variables that affect the infection growth significantly while diabetes and type of cleaning disinfectant had marginal effects. Further study is required to clarify the best treatments in this area, as the treatment option antibiotics have nearly similar results.</span>
文摘Cyanopolyynes (H[C≡C]n-CN or HC2n+1N, where n = 1, 2, 3, …, n) are commonly observed in the interstellar medium (ISM) as well as in the envelopes of carbon-rich stars. These linear molecular structures can be well described with a one-dimensional conduction model, which considers the scattering processes of electrons through the charge transfer conduction bridge of the H[C≡C]n-molecular wire containing the CN group as an electron-acceptor terminal unit. Therefore, our results using this model enable a better understanding of the longest molecules observed in interstellar space and provide new insight into why these particular cyanopolyynes reach a maximum length, such as is observed from astronomical experimental spectral data and cosmological chemical models. Dipole moments and geometrical parameters of these cyanopolyynes were obtained from ab initio molecular orbital calculations using the restricted Hartree-Fock approach and 6-311G* basis set, in order to obtain the inner resistance as a new parameter of chemical reaction feasibility for this molecular series. Using this last molecular parameter, we have been able to analyze the possibility of identifying long molecular species that can be found under local thermodynamic equilibrium in some ISM such us HC25H, HC27H, and HC29N, which have not been observed at present.
文摘We present a theoretical investigation of the influence of photo-excitation and spin wave scattering on magnetization of the (Ga,Mn)As diluted magnetic semiconductor (DMS) quantum wires (QWRs) and quantum wells (QWs). Double time temperature dependent Green’s function formalism is used for the description of dispersion and spectral density of the systems. Our analysis indicates that spin wave scattering plays an influential role in magnetism of both systems while application of light is insignificant in quantum wells. In the absence of spin wave scattering and at sufficiently low temperatures, a result corresponding to the specific heat of dominating electronic contributions in metals is obtained in QWs. In QWRs, however, this magnetic property is found to vary with T1/2 and α2T1/2 so that light matter coupling has a leading effect on lower temperatures, where α is the light matter coupling factor and T is the temperature.
基金financially supported by the National Natural Science Foundation of China(No.51271021)Beijing Natural Science Foundation(No.2162025)State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing
文摘In this study, the mechanical properties of tungsten-rhenium wires with nanofibrous microstructure were investigated at both room temperature(RT) and 800?C. The strengthening mechanism associated to the nanofibrous microstructure was discussed. The results showed that the tungsten-rhenium wires with nanofibrous grains exhibited a very high tensile strength reaching values of 3.5 GPa and 4.4 GPa for the coarse(grains diameter of 240 nm) and fine(grains diameter of 80 nm) wires, respectively. With increasing the temperature from RT to 800?C, the tensile strength decreased slightly but still held high values(1.8 GPa and 3.8 GPa). All the fracture surfaces exhibited apparent necking and characteristics of spear-edge shaped fracture surface, indicating excellent ductility of the wires. A model of the strengthening mechanism of these tungsten-rhenium wires was proposed.
文摘The effect of different regimes of heat treatment on the tensile strength of SiC coatedcomposite of C fibers reinforced Al wires has been investigated.Their tensile strengthmay increase under treatment either at 500℃ for 2h or 550℃ for 1h,but decreaseover 600℃.After the strength tests of extracted fibers from composite wires,theSiC coating is an excellent protection to C fibers.EPMA and EDAX showed that theC/Al interface of the composite wires is stable under treatment below 600℃,butunstable at