effects of rotate speed on magnetorheological fluid viscosity、sedimentation stability and rheological property are investigated during its preparation under taking carbonyl iron particle and silicone oil as dispersed phase and continuous phase separately while adopting the method of using high performance ball mill to disperse. The research showed that rotate speed greatly influenced the magnetorheological fluid performance. With constant increasing of rotate speed, the fluids viscosity presented decreasing first and then increasing trend, when rotate speed reached 300rpm, the obtained viscosity was lowest. There was a good corresponding relation between its sedimentation stability and viscosity that meant fluids with strong viscosity sedimentate lowly and fluids with weak viscosity sedimentate quickly. When rotate speed was 400rpm, it could get best sedimentation stability and highest shear stress. Therefore, basing on the fixed composition of magnetorheological fluid, the fluids viscosity、sedimentation stability and rheological property can be changed by changing ball mill rotate speed during magnetorheological fluid preparation.

The effects of Co microalloying and annealing technology on the transformation, microstructure and shape memory effect (SME) of Ti-Ni shape memory alloy were investigated by differential scanning calorimetry, optical microscopy, X-ray diffraction and tensile test for Ti-49.8Ni and Ti-49.8Ni-1.0Co alloys annealed at 400℃ and 600℃, respectively. The results are described as follows. The A→R→M (A-parent phase, R-R phase, M-martensite) two-stage transformations takes place in Ti-49.8Ni and Ti-49.8Ni-1.0Co alloys during cooling from 400℃ annealing, while during heating the M→A one stage and M→R→A two-stage transformations takes place in Ti-49.8Ni and Ti-49.8Ni-1.0Co alloys, respectively. The 400℃ annealed Ti-49.8Ni and Ti-49.8Ni-1.0Co alloys show fiber microstructure and poor plasticity, and the 600℃ annealed alloys shown equiaxed grains and good plasticity. Since Ti-49.8Ni alloy at room temperature consist of a single martensite, the alloy exhibits SEM, while Ti-49.8Ni-1.0Co alloy consist of a single parent phase B2, and thus shows superelasticity (SE). The effect of the annealing time on microstructure and properties of Ti-Ni alloy is not obvious. The transformation temperature of the Ti-Ni alloy increases slowly with increasing annealing time. The deforming temperature obviously affects the SE of Ti-Ni alloy. The SE stress increases and the SE loop area decreases in Ti-Ni alloys with increasing deformation temperature.

The evaluation indicator of thixotropy of magnetorheological (MR) fluid was studied by experiment. Experimental results show that, the thixotropic crack index which got from the relationship between apparent viscosity and shear rate has better testability and repeatability, and can be used as evaluation indicator of thixotropy of MR fluid. And as its test results also have good stability and possessing lots of performance information of MR fluid, thixotropic loop can also be used as evaluation indicator of thixotropy. Moreover, lower shear rate and shorter duration are apt to get distinct thixotropic loop.

A novel kind of thermoresponsive shape memory fiber was prepared by mixing the P(SA-co-AA) copolymers of stearyl acrylate (SA), and acrylic acid (AA), with PVA polyvinyl alcohol through chemically crosslinking after spinning and drawing. The molecular structure, thermomechanical properties and shape memory behaviors of mixed fibers with different drawing ratio were investigated. It was found that the rupture strength of fibers increased and the swelling ratio of them decreased with the increasing of drawing ratio. The crystal melting temperature increased and the module of fibers increased.The drawed P(SA-co-AA)/PVA fibers also showed a good shape memory effect, and the shape reversion ratio increased with the increasing drawing ratio.

Electrospinning technique is considered as a simple and potential method for synthesizing nanofibers with various materials, which has been applied to many fields. In this manuscript, the electrospinning technique and factors which affect the quality and the morphology of namofibers were summarized. The synthesis of semiconductor oxide nanofibers by electrospinning and their applications in gas sensor field were described. Gas sensing properties of some materials of nanofibers and nanowires or nanotubes were compared. The mechanism of excellent performance of gas sensiors made of nanofibers is analyzed.

Carbon nanotubes gas sensors are attracted more attentions for its exceptional properties of lower work temperature and detection limit. While the oxide semiconductor doping with carbon nanotubes gas sensors have the advantages both of carbon nanotubes gas sensors and oxide semiconductor gas sensors, such as higher sensitive, lower work temperature and detection limit. The progress and gas-sensing mechanism of this two kinds of gas sensors are introduced and summarized in this paper, and also the problems and developing tendency are pointed out.

Sr-doped LaFeO3 powder was prepared by the method of microwave chemical synthesis. The crystal structure and morphologies of Sr-LaFeO3 were characterized. The results show that the La0.91Sr0.09FeO3 was pure perovskite structure, the dispersive of La0.91Sr0.09FeO3 particle is uniform and the particle size is about 65nm. The sensitivity and selectivity of La0.91Sr0.09FeO3 for 10 ppm toluene are good, and the response-recovery times are about 40 and 50s, respectively.

Abstract: The safety of MRF is an important guarantee for its application, so it's of significance to research the conductive properties (insulating properties) of MRF. The aim of this paper is measuring the MRF's resistance with the magnetic field, and anglicizing its electric properties. The article has designed MRF resistors, which is made of metal cylinder containers and filled with magnetorheological fluid. With the magnetic field effect, the magnetic particles between two metal plates connected into chains, which make conductivity between two plates change, causing the decrease of resistance. We deduced resistance expression, and the experimental results matched the expection.

Taking into account the effects of the magnetic saturation and non-linear magnetization, a finite element analysis is performed for the magnetic-mechanic responses of a single chain in a magnetorheological fluid (MRF). The effect of the number of the particles in a chain on the shear resistance is investigated. Making used of a statistical approach, the critical shear stress of MRFs are obtained, and the results are identical with the experimental results. It is found that finite element method can be used to describe the response of MRFs, which may be of help for the initial design and optimization of high-performance MRFs.

Abstract: Mg-doped LaFeO3 powder was prepared by the method of microwave chemical synthesis. The crystal structure and morphologies of Mg-LaFeO3 were characterized. The results show that the LaFe0.7Mg0.3O3 was pure perovskite structure, the dispersive of LaFe0.7Mg 0.3O3 particle is uniform and the particle size is about 20nm. The sensitivity and selectivity of LaFe0.7Mg 0.3O3 for 100 ppm formaldehyde are good, and the response-recovery times are about 55 and 25s, respectively.

The effects of oleic acid and lauric acid on the stabilization of magnetorheological fluids (MRF) were investigated experimentally. Several groups of samples were prepared, with both lauric acid and oleic acid as additives. The variations of the zero-field viscosity, mechanical property and sedimentation rate of these samples against time were tested, and the effects of volume fractions of lauric acid, oleic acid and carbonyl iron on the stabilization and mechanical property of the MRF samples were studied. The results indicate that the proper addition of lauric acid and oleic acid could significantly improve the mechanical property of magnetorheological fluids.

Abstract: The WO3 material with interwoven meshwork conformation was successfully prepared using eggshell membrane as template by an aqueous soakage technique followed by calcination treatment. The phase composition and microstructure of the prepared nano-material were characterized by XRD and SEM. The sensitivity to H2S sensing properties was measured, the effects of calcination temperature, sensor operating temperature and concentrations of H2S gas on the sensitivity were investigated．The results show that the sensitivity of material calcinated at 700℃ to 30ppmH2S reaches 687 with a short response time and there has a good linear between sensitivity and concentration.

High driving frequency of magnetic field is one of the key factors which restrict the popularization and application of giant magnetostrictive thin film device. The research on how to reduce the magnetic field driving frequency of giant magnetostrictive thin film device has important significance to the popularization and application of this kind of device. Based on the deep analysis of fundamental reason which cause giant magnetostrictive thin film existing anisotropy, combining the motion mechanism of domains in the magnetostrictive process of thin film, the paper puts forward a new idea that as long as it is able to overcome the demagnetizing field existing in giant magnetostrictive thin film, better dynamic characteristics can be obtained in the direction of hard magnetization axis under low driving frequency of magnetic field. An experiment is carried out in the hard magnetization axis experimental system of giant magnetostrictive thin film. The results show that it is able to make the thin film generate superharmonic resonance with excellent response through applying a suitable bias magnetic field to overcome demagnetizing field. The experimental results provide a new way for reducing the diving frequency of giant magnetostrictive thin film device.

The effects of electropulsing ageing on microstructure and shape memory effect in Fe14Mn6Si8Cr5Ni alloy have been studied. The results show that electropulsing ageing after pre deformation has a much more remarkable improvement in shape memory effect than directly electropulsing after water quenching. The shape recovery ration in Fe14Mn6Si8Cr5Ni alloy can rise up to 70.3±1.0% through electropulsing ageing for 1 s, up to 87.5±1.0% for 300 s after 10% tensile pre deformation. The shape recovery ration of 87.5% is increased by 82.3% compared to that in a water-quenching alloy, while it can be only increased by 22.3% through directly electropulsing ageing. Metallographic and TEM analysis show that no thermal induced ε martensite in an alloy electropulsing aged after pre deformation appears and it results in increase of the austenite matrix. What is more, electropulse can accelerate collapsing of vacancies and dislocations introduced by pre deformation and the formation of stacking faults. It was the above two reasons that make the rapid improvement in shape memory effect through electropulsing ageing after pre deformation.

Abstract: Magnetorheological fluid is an excellent fluid material with intelligence. Its fluid properties, damping characteristic and magnetism characteristic have been widely studied, but its electrical properties’ research is relatively slow. This paper used MRF - J01T type MRF and inductance coil to constitute magnetorheological inductance and deduced the formula of calculating magnetorheological inductance. Besides, the article designed experiments to test the magnetorheological inductance’s properties with the change of the external magnetic field and analyzed the experimental phenomena in theory. So the paper provides an adjustment for magnetorheological inductance’s application in electronic measurement and sensing technology .

The Tb0.3Dy0.7Fe1.95-xZrx (x=0, 0.03, 0.06, 0.09) alloys were prepared by arc melting furnace. The crystal structure, microstructure and the magnetostriction of the Tb0.3Dy0.7Fe1.95-xZrx (x=0, 0.03, 0.06, 0.09) alloys were studied. Results demonstrated that the matrix phase of the Tb0.3Dy0.7Fe1.95-xZrx (x=0.03, 0.06, 0.09) alloys consisted predominantly of the cubic Laves phase with MgCu2(C15-type) structure. After Zr addition, the lattice parameter of the Laves phase in the alloys decreased by substituting rare earth elements Tb and Dy. The formation of the ZrFe2 phase as the primary phase made the solidifying liquid become rich in rare earths and suppressed the formation of the deleterious RFe3 phase. Zr was found to be limited soluble in the matrix RFe2 phase and negligible soluble in Re-rich phase. ZrFe2(C15-type) phase could dissolve into the RFe2 phase which crystal structure is C15-type and form the matrix (Re,Zr)Fe2 phase. The solubility of Zr in the matrix phase was found to be supersaturated(x=0.09), and Zr-rich phase formed as a new phase on the matrix (Re,Zr)Fe2 phase. The concentration of the element Zr affected the magnetostriction significantly. The improvement in magnetostriction was remarkably for the element Zr addition alloys with a low concentration as compared to the parent alloy Tb0.3Dy0.7Fe1.95. However, the decrease in magnetostriction at a higher concentration (x=0.09) was due to the formation of Zr-rich and Re-rich phases affecting magnetostriction. Whereas the magnetostriction had little improvement as compared to the parent alloy Tb0.3Dy0.7Fe1.95.

Ce-doped WO3 nanoparticles were synthesized by sol–gel method starting from ammonium tungstate hydrate, Cerous nitrate, alcohol, ammonia and nitric acid. The crystal structure and phase of the nanoparticles were characterized by XRD. The results shows a small number of doping Ce can get a single crystal and enhance crystallinity. The morphology of nanoparticles was characterized by Scanning Electrons Microscope and BET. The thermal decomposition behavior of the 5%Ce+WO3 xerogel was investigated by TG-DTA. The results show that as-synthesized nanoparticles contain the adsorbed water and some organic compounds below 450℃. Pure WO3 and Ce-doped WO3 thick film sensors were prepared and tested for specific sensitivity to H2S. Compared to the pure WO3 sensor, Ce-doped WO3 sensors have better ability of anti-humidity during the relative humidity RH=20~70%.

Abstract: Electroless nickel and nitriding on the surface of iron powder in suspended phase can improve the property of magnetorheological fluid. The antioxidation of iron powder is improved through the electroless nickel and nitriding by SEM、TG、XRD and magnetization characteristic, Fe4N is formed on the surface of iron powder through the nitriding. The wear resistance of magnetorheological fluid is improved through nitriding by friction performance analysis.

Abstract: The electrical characteristics of magnetorheological fluid can be widely used in automatic control, medical, automotive, aircraft manufacturing and many other areas . This article have derived the formula of MRF between capacitance and Dielectric constant,made the Capacitors which can load the MRF. And then we measure the change of capacitance when the MRF is seen as a kind of electrolyte during the time of magnetic field change . And we also measure the sensitivity of the dielectric constant of different concentrations of MRF as the magnetic field changes.And at last,we have made the Curve of the capacitance - magnetic induction intensity , capacitance- concentration and Then the experimental results have been analyzed.We have the Conclusion that When the magnetic field increases, the dielectric constant is also larger, resulting in increased capacitance of the conclusions of MRF.

Abstract: The gas sensitivity of different matels doped ZnO nanowires to different concentration of H2 and CO was measured at 350℃.The results showed that the highest gas sensitivity of Ni doped ZnO nanowire to CO was 45.158 at its concentration of 3.92×10-3, and the highest gas sensitivity of Ag doped ZnO nanowires to H2 was 28.549 at its concentration of 2.52×10-3. In addition, linear fitting was applied on the basis of gas sensitivity curve by Origin software, by which the unkown concentration of H2 was determinated effectively. In the end, the reason of the improvement of gas sensitivity of ZnO nanowires by metal dopant was disccussed. It was believed that the chemical state of the metal was the essential reason to enhance the gas sensitivity of ZnO nanowires.

The influences of rapidly solidification on the structure and property of the Fe-Mn-Si base shape memory alloy were studied.The results show that the because rapidly solidification big refined structure, Thus causes the alloy yield strength enhancement,At the same time, produce many martensite in rapidly solidification sample, this kind saves in advance the martensite is also helpful in enhances the substrate the intensity, thus suppresses the irreversible plastic deformation the production,lets more distortions undertake by the stress-inducedεmartensite,compares with the rolling sample, the shape memory effect enhances about 13%~200%; Because the crystal grain of the rapidly solidification sample is tiny, the crystal boundary are many, may supply the magnus build nucleus the position to be also many, therefore theεmartensite is long quite tiny, also easy to have the overlapping traversing phenomenon.

The surface modification of powdered carbonyl iron is necessary for the enhancement of its adhesion to silicon oil and MRF sedimentation stability by dispersion-polymerization. In this paper, Silane coupling agent was used for the surface modification of Carbonyl iron powder. The structure, morphologies and particle size of unmodified and modified carbonyl iron powder were characterized by fourier transform infrared spectroscopy, SEM as well as laser particle size analyzer. The results showed that carbonyl iron powder surface adsorbed coupling agent and particle size increased 2.4 times while there was good affinity with silicon oil. The modified carbonyl iron powders can be used for enhancement of MRF sedimentation stability. Adding coupling agent can strengthen MRF viscosity, but it effects weakly on rheological property.

Abstract: The light-thermal sensitive microcapsule is synthesized by interfacial polymerization method, which can act as novel information recording material, and the capsule core is distinguished by the encapsulated monomer. The surface topography of unencapsulated core material UV-curing is studied by atomic force microscopy, and the monomer curing property in microcapsule is analyzed by infrared spectroscopy technology, and the developing density of light-thermal sensitive microcapsule is detected by thermal imaging technology. The results show that curing speed of different monomer mainly depended on the function groups and surface topography of curing product have related on the contents of unsaturated C=C bond in monomer. The curing speed of different monomer and cross-link density of curing product are the main factors effecting on the developing density of light- thermal sensitive microcapsule. Base on the experimental results, the effect of monomer on the developing density is ranked as: TMPTA>(PO3)TMPTA>DPGDA.

Cellulose acetate film was prepared by solution casting method. Composite sensing film can be obtained via immobilization of fluorescent indicator and glucose oxidase on cellulose acetate film. Surface morphology of composite sensitive film and enzymatic activity were analyzed by scanning electron microscope and UV-visible spectrometer. Fluorescent indicator does not leak. The stability of the immobilized enzyme was higher than the free enzyme. All above indicate this kind of cellulose acetate film can be a good immobilization carrier of fluorescent indicator and enzyme.

To ensure the torque transmission properties of magnetorheological transmission device, the experimental method is used to analyze the effect of material, rough, surface morphology of disk, slip speed and working gap on the torque transmission properties. The results indicate that material of wall has a significant influence on the properties, the lower the permeability of material, the smaller the torque transmits, and the wall effect will appear; the surface morphology of disk has also an important influence on the transmission properties, the concave convex concentric circles surface reduces the torque; when the slip speed is higher, the process of particles chains formed is complex and the torque will be lower, the working distance has little effect on the transmission properties.

Abstract: This paper dealt with the preparing conditions and morphology of flower-like, tetrapod-like and amorphous zinc oxide whiskers, which were prepared by oxidation of zinc metal in the air and by introducing active carbon as a reaction catalyst. The product was pure zinc oxide verified by XRD patterns of ZnO whisker, in which the peaks are sharp with narrow half-widths and can be identified as a wurtzite ZnO structure. Morphology of ZnO whiskers was affected greatly by carbon black usage and the reaction temperature. The possible growth mechanisms on the ZnO nano-whiskers were proposed in this paper. The gas sensing properties of the ZnO layers were tested with CH3OH, C2H5OH, CH3COCH3 and n-C3H7OH, respectively. The ZnO sensors show typical n-type metal oxide semiconductor behavior, the resistance decreases as the gases are increased. The sensors has a higher sensitivity to n-C3H7OH than the sensitivity to other gases. The zinc oxide sensor has higher gas response values and a fast response.

Polyaniline (PANI) and its doped materials (In2O3-PANI, TiO2-PANI and SnO2-PANI) were synthesized by chemical polymerization of protonic acid method in 0℃ water bath. Aniline was oxidized by ammonium persulfate in hydrochloric acid solutions. The polyaniline and its composite materials were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and FT-IR spectromete (FI-IR). The gas sensors were fabricated based on polyaniline and its doped materials to detect NH3 at the room temperature. The response sensitivity of the gas sensors to NH3 was measured in NH3 concentration range of 10 ppm ~ 150 ppm. The relationships of the sensitivity of the sensors vs the NH3 concentration basically showed linearity. The sensitivity of the gas sensor based on In2O3 doped PANI was the highest and it is 50 for 150 ppm NH3 at room temperature. While response times of the gas sensor based on TiO2 doped PANI was the shortest in these four kinds of gas sensors and the response times was 60 s. The gas sensitive mechanism of polyaniline and its doped materials was analyzed. The doping of metal oxides has great effect on the properties of PANI materials such as response sensitivity, response and recovery times and selectivity.

Mn1.05-xCo0.92Ni0.03PbxO4(0.04≦x≦0.16) series NTC thermistor ceramics were studied using XRD ，SEM and electrical properties measurement，especially focusing on the variation of sintering characteristics and electrical parameters with Pb-doped amount. The results showed that the sintering temperature and the resistivity were decreasing while increasing the amount of Pb-doped. The sample with the best stability and largest contractibility was obtained when x=0.12. At the same time, the optimum sintering temperature decreased to 900~950℃. The value of ρ25 and B for the sample sintered at 950℃ were 490Ω?cm and 3969K.

Abstract: To improve the accuracy of calculating the rheological behavior of magnetorheological fluid by dipole approximation, the limits of validity for dipole approximation is analyzed by the method of comparing the dipole model with the finite element model, the errors of dipole approximation of magnetorheologcial fluid with different volume fractions are calculated. The results indicate that the particles are mainly affected by the adjacent particles, the maximum relative error of dipole approximation appears in the point nearing the adjacent particle and the value is 62%. When the volume fraction of magnetorheological fluid is 6.5%, the maximum error of dipole approximation is 3% and the dipole model is valid; while the volume fraction is 20%, the maximum error change to 19% and the dipole model is invalid. The external magnetic field has influence on the error of dipole approximation, the stronger the magnetic field, the little the relative error.

Shape memory alloy is a kind of metal intelligent material which can change phase under the action of temperature and pressure. It has been widely used in transportation, aerospace, biomedicine and many other fields. With the continuous improvement of advanced engineering technology for the intelligent and functional diversification of metal structure materials, the traditional mechanical transmission structure shows disadvantages such as poor stability and complex structure, which are increasingly difficult to meet the needs of the present stage. Shape memory alloy has attracted great attention by virtue of its excellent mechanical properties. It is urgent to analyze its multi-field application in order to promote the interdisciplinary integration and the formation of a complete knowledge system. In this paper, we review application frontier of shape memory alloy in automobile industry, aerospace, biomedical, and building at home and abroad, analyze research progress of basic features such as shape memory effect, superelasticity, high damping property, biocompatibility and elastothermal effect, and discuss the shortcomings of shape memory alloy research at present and the future application prospect and development direction.

Effect of the times of thermo-mechanical training on the shape memory of Fe-Mn-Si shape memory alloy was studied in this paper. The results show that with the increase of the number of training, alloy strain recovery rate rises to the highest 1.95% after three training sessions and then begins to decrease. Microstructure analysis showed that the rise of it in the initial stage could be attributed mainly to thermo-mechanical training, inducing martensitic preferred orientation and resulting in a uniform distribution of martensite which is running parallel with each other with few of crossover. While the decrease of the recovery rate is primarily due to the serious dislocation tangle forming inside the alloy matrix, which leads to irreversible plastic deformation.

The thermal expansion behaviors and spontaneous magnetostrictive of Gd2Fe14Cr3 compound have been studied by means of X-Ray diffraction and magnetization measurements.The results show that the Gd2Fe14Cr3 compound has a hexagonal Th2Zn17-type structure from the temperature 294K to 692K,the Curie temperature of Gd2Fe14Cr3 compound is about 540K,the value is 30K higher as compared to the Gd2Fe17 compound. The Gd2Fe14Cr3 compound has negative thermal expansion in the temperature range 452~512K, the value is -1.6×10-5/K,and the results of magnetostrictive show that the spontaneous magnetostrictive of Gd2Fe14Cr3 compound is anisotropy, the spontaneous volume magnetostrictive deformation comes mainly from the contribution of the spontaneous linear magnetostrictive deformation along the c axis .

Carbonyl iron powders were produced in different sizes by using ball mill and controlling the milling time, and 8 MRFs with single-sized particles and 6 MRFs with dual-sized particles were obtained. Zero-field viscosity and shear stress were tested through rotational rheometer. Test results show that shearing stress of MRFs with dual-sized particles was enhanced comparing with MRFs with single-sized particles in the same magnetic fields. The enhanced effect was closely related to the composition of particles. Also, its zero-field viscosity and sedimentation stability had tiny differences comparing with MRFs with single-sized particles.

　　 SnO2 morph-genetic ceramic with special ramie form has been prepared by taking modified ramie fibers as templates. The phase composition and microstructure of the prepared materials are discussed, and their specific surface area, pore size distribution and gas sensitive property of multiple gas (liquid) are tested. The results show that the structure and properties of morph-genetic materials can be controlled effectively by modifying textile fibers. The modification of templates has great influence on specific surface area and pore structure parameters of SnO2 morph-genetic ceramic, but less for grain size. Especially the SnO2 fabricated by ramie fibers template treated with alkali liquor shows high specific surface area and superior absorption characteristic for HCHO、C2H5OH and Petrol gas (liquid).

P(DHCA-co-LCA)-b-PEG polyesters were synthesized by polycondensation of 3,4-dihydroxycinnamic acid (DHCA, caffeic acid), lithocholic acid (LCA) and poly(ethylene glycol) (PEG). The structure and molecular weight of the P(DHCA-co-LCA)-b-PEG polyesters were characterized by fourier transform infrared (FTIR), nuclear magnetic resonance (1H-NMR) and gel permeation chromatography (GPC). The thermal and photosensitive properties of the polyesters were investigated by differential scanning calorimeter (DSC), UV spectroscopy and fluorescence spectroscopy. It is proved that glass transition temperature (Tg) and fluorescence emission intensity of the polyesters decreased when PEG increased in feed, but the fluorescence emission intensity of the polyesters obviously higher than DHCA monomer. P(DHCA-co-LCA)-b-PEG polyesters could be photo-crosslinked under λ>310nm UV light and its reversible photo-cleavage could take place under UV light of 254nm. The micelle nanoparticles were obtained by self-assembly at selective solvent. It was found that these nanoparticles have a nice spherical morphology with a smooth surface and possessed a certain photosensitivity based on the analysis of laser light scattering (LLS) and transmission electron microscopy (TEM). Their average diameter was about 378nm.

Negative temperature coefficient (NTC) ceramic with spinel structure of Fe-Co-Mn-Ni composition, doped by the ion La3+, was prepared by the Pechini method. The phase composition and microstructure of materials were characterized by means of X-ray diffraction and scanning electron microscope，and the electric properties and aging were also measured. The experimental results show that thermo-sensitive ceramics obtained at 1100℃ was steady, the prepared sensors have resistance in the range from 90 kΩ to 120 kΩ at 20 K, the sensitivity ranged from 0.5 kΩ/K to 45 kΩ/K in the temperature range from 45 K to20 K. The current-induced temperature error is less than 0.1 K at 20 K. The values of thermistor constant, B20 K/40 K range from180 K to 210 K.

杆形颗粒磁流变液是新近出现的新型磁流变液，它比传统磁流变液具有更好的力学性能。基于磁力学理论，通过分析磁化链中杆形颗粒的受力，包括磁力、压力、摩擦力及磁场对颗粒的力矩等，建立了磁流变液的剪切屈服应力模型。计算结果表明，该模型能描述不同磁场强度下杆形颗粒磁流变液的屈服应力，并通过分析摩擦的影响，发现颗粒摩擦系数对磁流变材料的剪应力影响较大。

A novel mineral oil-based magnetorheological fluids was prepared with carbonyl iron powder for magnetic particle and SiO2 particles as thixotropic agent，The effect of particle size of SiO2 on magnetorheology, stability and tribological performance of magnetorheologicalfluids was studied by measuring the zero field viscosity, rheological curve, sedimentation rate, and the friction coefficient et al.. The results indicated that the SiO2 with middle particle size as a thixotropic agent could significantly improve the zero-field viscosity, and field-induced shear stress was enhanced with SiO2 in small particle size. Sedimentation stability was improved significantly with the increase of the particle size of SiO2, but the dispersion performance was poor with larger apparent viscosity of sediment. In addition the magnetorheological fluid showed good anti-friction performance with average SiO2 particle size in 15nm and 100nm.

In this paper,The impact of temperature on magnetorheological fluid responsive particles,carrier liquid and additives is studied. The magnetorheological fluid with Excellent temperature performance is prepared.The magnetorheological fluid viscosity-temperature relationship is analyzed. At the same time,the performance of magnetorheological fluid shock absorber at different temperature is discussed.

Cyclic tensile tests of shape memory alloy bars with four different diameters were conducted. The effects of heat treatment, cyclic loading-unloading numbers, strain amplitude on the mechanicalbehaviour of SMA bars were analyzed. The mechanical parameters such as residual strain, energy dissipation per cycle, secant stiffness, equivalent damping ratio were studied with different strain amplitude and cyclic loading-unloading numbers. The experimental results indicate that the phase transformation stress was higher when the heat treatment scheme was 400 ℃ for 15 min for 14 mm SMA bar. The mechanical properties were basically stable after 5 cyclic loading-unloading cycles, which should be considered in engineering applications. The test results provided a basis for the use of large size SMA bars in self-centering structures.