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The compression behavior of the lattice-walled tubes under variable strain rates are investigated by numerical simulation, and the stress-strain relationship of the structure under quasi-static loading is theoretically analyzed. The finite element software LS-DYNA is used to simulate the structure established by the beam element, and the critical impact velocity is obtained when the structure collapses layer by layer. According to the plastic hinge theory and considering the combined action of the beam's bending moment and axial force in the structure, the stress-strain relationship of the structure under quasi-static loading is derived and compared with the experimental results. The numerical simulation results reveal that the structure of the single-layer gradient tube(SGC) does not undergo shear deformation under quasi-static and low-speed impact. The critical speed of the gradient square tube(GS) is higher than that of a cylindrical tube. The theoretical model can correctly reflect the mechanical response of the structure under uniaxial compression.

The fiber Bragg grating sensor is widely used in strain monitoring of large metal structure and trend to replace the resistance strain gauge due to its advantages of strong stability, high measurement accuracy, multiple points measuring, strong environmental suitability and long transmission distance. The temperature-induced strain, which can have the same order of magnitudes as the mechanically-induced strain, will cause great errors in the strain monitoring. Therefore, the temperature compensation for the sensors is essential to guarantee the measurement accuracy. The existing theoretical models and experiment platforms for analyzing the temperature compensation are established by assuming that the testing temperature is constant. However, the surrounding temperature of some large metal structure is not stable, and the effect of temperature change cannot be neglected. This paper aims to establish an analytic model and an experiment platform to compare the temperature compensation of the fiber bragg grating sensor and the resistance strain gauge. The superiority of the temperature compensation for the fiber bragg grating sensor is verified. The result provides theoretical support for choosing the fiber bragg grating sensor in the long-time strain monitoring.

Purpose This paper aims to investigate the influence of structure parameters on giant-magnetoimpedance (GMI) effect measured by non-contact method. Design/methodology/approach The GMI sensor contains a Co-based internal magnetic core fabricated by laser cutting and an external solenoid. The influences of magnetic permeability of magnetic core and structure parameters on GMI effect were calculated in theoretical model. The output impedance, resistance, reactance and GMI ratio were measured by non-contact method using impedance analyzer. Findings Enhancing external magnetic field intensity can decrease the magnetic permeability of core, which has vital influences on the magnetic property and the output response of GMI sensor. In addition, increasing the width of magnetic core and the number of solenoid turns can increase the maximum GMI ratio. The maximum GMI ratio is 3,230% with core width of 6 mm and solenoid turns of 200. Originality/value Comparing with traditional contact-measured GMI sensor, the maximum GMI ratio and the magnetic field sensitivity are improved and the power consumption is decreased in non-contact measured GMI sensor. GMI sensor measured by non-contact method has a wide range of potential applications in ultra-sensitive magnetic field detection.

With high permeability and low modulus, the cellular substrate can achieve larger elastic stretchability and better wearing comfort than the solid substrate used for stretchable electronics. Since the porosity of the cellular substrate is a dimensionless ratio value, a fixed porosity can result in innumerable cell sizes. And different cell sizes will bring different stiffness, which has a strong impact on the elastic stretchability of stretchable electronics. In this paper, a numerical model is established for a particular structure where the serpentine interconnect is bonded on cellular substrates with the fixed porosity ( ϕ = 80 % ). Eight different cell sizes are selected for this porosity and two stretching directions, along and normal to the cell walls, are studied. Base on the results from the model, the curves of elastic stretchability versus the ratio of wall width to serpentine width ratio ( δ / w ) can be obtained. Results demonstrate that the appropriate ratio δ / w ≈ 1 yields significantly larger elastic stretchability than other cell sizes of cellular substrates. This finding can provide an engineering design regulation for stretchable electronics based on cellular substrates.

The heating process of cured tobacco leaves will largely affect the final composition and content of gas products. The knowledge of the instant thermophysical properties of an individual tobacco leaf are important and necessary for deep understanding and further predicting the process. In this work, the thermal conductivity and volumetric heat capacity of a single tobacco leaf are simultaneously measured using an advanced transient electrothermal technique, in which the heating temperature can be well controlled by simply adjusting the feeding current. The measured thermal conductivities and volumetric heat capacities at different temperatures in the beginning stage of heating shows that the thermal conductivity of a single tobacco leaf decreases against the temperature and dominate the heat transfer process in the tobacco leaves, while the volumetric heat capacity is almost constant in the low temperature range.

The fused filament fabrication (FFF) process deposits thermoplastic material in a layer-by-layer manner, expanding the design space and manufacturing capability compared with traditional manufacturing. However, the FFF process is inherently directional as the material is deposited in a layer-wise manner. Therefore, the in-plane material cannot reach the isotropy character when performing the tensile test. This would cause the strength of the print components to vary based on the different process planning selections (building orientation, toolpath pattern). The existing toolpaths, primarily used in the FFF process, are linear, zigzag, and contour toolpaths, which always accumulate long filaments and are unidirectional. Thus, this would create difficulties in improving the mechanical strength from the existing toolpath strategies due to the material in-plane anisotropy. In this paper, an in-plane isotropy toolpath pattern is generated to enhance the mechanical strength in the FFF process. The in-plane isotropy can be achieved through continuous deposition while maintaining randomized distribution within a layer. By analyzing the tensile strength on the specimens made by traditional in-plane anisotropy toolpath and the proposed in-plane isotropy toolpath, our results suggest that the mechanical strength can be reinforced by at least 20% using our proposed toolpath strategy in extrusion-based additive manufacturing.

Purpose This paper aims to investigate magnetic field anneal in micro-patterned Co-based amorphous ribbon on giant magneto-impedance (GMI) effect enhancement. Design/methodology/approach The amorphous ribbons were annealed in transverse and longitudinal magnetic field. The influence of different field annealing directions on GMI effect and impedance Z, resistance R and reactance X with a series of line width have been deeply analyzed. Findings In comparison with GMI sensors microfabricated by unannealed and transversal field annealed ribbons, GMI sensor which was designed and microfabricated by longitudinal field anneal ribbon performs better. The results can be explained by the domain wall motion and domain rotation during annealing process and the geometric structure of Co-based GMI sensor. In addition, shrinking the line width of GMI sensor can promote GMI effect significantly because of the effect of demagnetizing field, and the optimum GMI ratio is 209.7 per cent in longitudinal field annealed GMI sensor with 200 μm line width. Originality/value In conclusion, annealing in longitudinal magnetic field and decreasing line width can enhance GMI effect in micro-patterned Co-based amorphous ribbon.

为了彻底改善TFT-LCD的Line Zara不良，本文建立了Line Zara失效模型，并分析了Line Zara失效机制，其中Line Zara发生率与外力大小及玻璃弯曲形变程度成正比，与框胶至柱状隔垫物距离、框胶粘结力成反比。基于Line Zara的失效机制，针对性地提出了改善措施并进行了实验验证。实验结果表明，减薄时的抛光工艺、减薄后运输箱的填充密度和框胶粘结力对Line Zara有显著的影响。随着抛光压力的减小和时间缩短，Line Zara发生率逐渐减少。随着运输箱中玻璃数量或隔垫物数量的增加，运输箱的填充密度逐渐增大，玻璃受外力发生的弯曲形变逐渐减小，相应的Line Zara发生率逐渐减小；当隔垫物为无尘纸时，玻璃的弯曲形变最小，Line Zara发生率最低。此外，当框胶与ITO粘结力增加12.5%、与PI粘结力增加66%后，Line Zara的发生率可降低至2%以下。TFT-LCD的Line Zara不良可通过降低抛光压力与时间、增加运输箱的填充密度和增加框胶粘结力彻底改善。

Enhancing the efficiency of visible light degradation is important for the actual application of TiO2/SiO2 (Ti/Si) composite materials for waste water treatment. In this manuscript, graphdiyne-doped TiO2/SiO2 (Ti/Si/GDY) (the Ti/Si composite exhibits a spherical shape with a diameter between 200 and 500 nm) composite material was successfully prepared using a hydrothermal method, which was utilized as photocatalyst for the photocatalytic degradation of methylene blue (MB) in aqueous solution under visible light illumination. Studies showed that Ti/Si/GDY-0.8 wt% exhibited superior photocatalytic degradation efficiency (91.8%) under visible light illumination than other composite materials such as Ti/Si/GDY-0.6 wt% (87.9%), Ti/Si/GDY-1.0 wt% (85.9%), and bare Ti/Si composite (32.3%). Moreover, Ti/Si/GDY also showed a higher photocatalytic degradation efficiency than other carbon materials (graphene (GR) and carbon nanotube (CNT) composited Ti/Si (Ti/Si/GR, Ti/Si/CNT)). The studies of the possible mechanism for the degradation of MA indicated that h+ was the major substance for the smooth degradation of methylene blue. Such a high efficiency photocatalyst might be also useful for the degradation of other contaminates in waste water or air.

The inevitably formed residual stress in the Selective Laser Melting (SLM) process leads to distortion, crack and even delamination of the workpiece. Single laser is commonly applied during SLM processing. However, its productivity is much lower than multiple lasers. In addition, the research of residual stress with multi-laser condition currently is limited in the open documents. In this paper, a three-dimensional (3D) thermo-mechanical model, with considerations of temperature dependent properties of Ti-6Al-4V, phase change and convective flow, is developed at first. Then, the numerical results of maximum temperature and dimensions of the molten pool are validated by available experimental data. Furthermore, a parametric study in regards to a series of scan strategies is investigated. According to the simulation results, the residual stress increases significantly when the laser number reaches four. The “two-zone technique” scan strategy decreases the equivalent residual stress by 10.6% compared to the successive scan strategy. With a shortening scan length, the residual stress first increases slightly, then decreases dramatically and attains the minimum when it is a quarter. Furthermore, for the multi-laser SLM process, carefully planning the scanning sequence and the sweeping direction to decrease heat concentration is beneficial in controlling the residual stress.

The hydrodynamic model for possible pentagonal and decagonal soft-matter quasicrystals is investigated, the effect of fluid which describes the difference of fracture theory between traditional structural material and the present novel material is considered. With this model, taking into account of equation of state, a complete hydrodynamics analysis is carried out. In the plane field of the soft-matter quasicrystals, the phonon, phason and fluid fields in time-spatial domain are quantitatively explored. A fluid stress intensity factor is suggested for the first time, whose physical action here leads to the closing of the crack surface, so is different from that of elastic (or phonon) stress intensity factor which leads to opening of the crack surface. The authors consider the cracking process of soft-matter quasicrystals is a process of competition between action of elastic stress and fluid stress to each other. In other words, the situation around the crack tip of the matter in stable or unstable lies in the competition results.

In this paper, we present a novel MEMS orthogonal fluxgate sensor fabricated by standard micro fabricated technology. The sensor mainly consists of a three-dimensional solenoid pick-up coil and a meander-shaped Co-based amorphous ribbon core. The experimental results demonstrate that the sensitivity and noise can be optimized by tuning operation conditions with excitation current amplitude and frequency. The fabricated sensor exhibits a maximum sensitivity of 575 V/T, a wide linear range of ± 480 μT, and a perming below 0.8 μT for 90 mA rms sinusoidal excitation current at 500 kHz frequency. The equivalent magnetic noise is 0.20 nT/√Hz at 1 Hz, and the RMS noise is 1.09 nT in the frequency range of 0.1–10 Hz under the same excitation. In comparison with other micro fabricated fluxgates in similar dimensions, this device possesses relatively high sensitivity and low noise spectral density.

We report an innovative integrated microfluidic platform based on micro-fluxgate and micro-coils for trapping and detecting magnetic beads. A micro-spiral coil fabricated by microfabrication technology is used to trap the magnetic beads, and the micro-fluxgate is employed to detect the weak magnetic field induced by the trapped magnetic beads. The fabrication process of the magnetic bead trapping system using a micro-coil is highly compatible with that of the micro-fluxgate sensor, making fabrication of this integrated microfluidic system convenient and efficient. It is observed that the magnetic bead trapping ratio increases as the number of magnetic beads is increased with a flow rate of 5 to 16.5 μL·min−1. Samples spiked with different concentrations of magnetic beads can be distinguished clearly using the micro-fluxgate sensor in this microfluidic system. In this study, the results demonstrate that the microfluidic system traps and detects magnetic beads efficiently and is a promising candidate for biomarker capture and detection.

Nickel-based single crystal superalloys have been widely used in modern aircraft, which is related to its high temperature mechanical strength and creep properties. And the initial cubic γ′ precipitates start to coarsen directionally during high temperature creep, which results in the degradation of the mechanical properties, especially the creep properties. Therefore, it is essential to figure out the mechanism of directional coarsening during the period of high temperature creep. In this article, a broad review of rafting mechanism of nickel-based single crystal superalloys is provided. The major work of this critical review is to introduce several experiments and numerical simulations which are used to analyze the evolution of rafting. For three different numerical simulations, their performance, advantage and disadvantage are discussed in detail. Through methods above, the effect on creep properties is summarized.

Purpose The paper aims to investigate the friction and wear properties of three surface-modified piston rings matched with a chromium-plated cylinder liner. Design/methodology/approach Samples were taken from the chromium-plated cylinder liner, Cr-Al2O3 ring, CrN ring and Mo ring. Tribo-tests were conducted on a reciprocating sliding tribometer under fully formulated engine oils. Friction coefficients and wear depths of three friction pairs were tested. Surface morphologies of cylinder liners and piston rings before and after test were analyzed. Findings Experimental results show that in the Cr-Al2O3 piston ring, scuffing occurred easily when matched with the chromium-plated cylinder liner; compared with the Mo ring, the CrN ring could decrease the wear depth of the piston ring from 2.7 to 0.2 μm, and the wear depth of cylinder liner remained; however, the friction coefficient increased from 0.113 to 0.123. The tribological performances of three surface-modified piston rings were significantly different when they matched with chromium-plated cylinder liner. Originality/value Chromium-plated cylinder liner and the three kinds of surface-modified piston rings have excellent friction and wear properties, respectively. However, according to the systematic characteristics of internal combustion (IC) engine tribology, only the appropriate cylinder liner–piston ring can improve the tribological performance of the IC engine. This paper reports the tribological performance of three surface-modified piston rings matched with a chromium-plated cylinder liner. The results can be used as reference for the design of high-power-density diesel engine.

A series of new monodisperse oligofluorenes mainly based on 9,9-bis(2-methylbutyl)fluorene units whose rigid core has been extended with 1-(trifluoromethyl)benzene termini ( F1, F2, F3 ) or hydrogen termini ( 8, 12 ) are designed and synthesized. The effects of conjugated length and end-capper groups on thermal, optical and electrochemical properties are studied. The oligofluorenes exhibit a narrower bandgap, higher HOMO, lower LUMO and red-shift on absorption/emission spectra with increasing number of fluorene units. Based on the comparing data of the compounds which have the same number of fluorene units, oligomers terminaled with electron-withdrawing group have a higher T g , narrower bandgap and red-shifts on absorption/emission spectra. Furthermore, in order to investigate the possibility of using these molecules as emitters in organic light-emitting diodes (OLEDs), solution-processed OLEDs with structure of ITO/PEDOT:PSS/PVK:oligomers/CsF/Al are fabricated. All devices based on the oligomers emit deep-blue light peaked at ca. 392–420 nm. Among these devices, the device based on hydrogen-terminated compound ( 12 ) displays the best performance with a high maximum luminance of 670 cd/m 2 , a low turn-on voltage of 4.20 V, and a maximum luminance efficiency of 0.38 cd/A.

The optical quartz glass is widely applied in optical system , photo communications，inertial navigation，etc.It must have high optical homogeneity. Optical homogeneity of the optical quartz glass directly affects the wavefront quality of the optical transmission system, and changes the wavefront aberration of the system. How to accurately determine the optical homogeneity of the quartz glass is especially important. Currently，the method of test for optical homogeneity mainly used by interference principle. This paper analyzes various existing interference measurement method and test equipment. Summarized the advantages and disadvantages of various test methods，using range and measurement accuracy.

For the key-optical material, the laser induced damage character of fused silica is crucial for the application among the optical laser fitting. As the defect of each point of the silica sample is diverse, and the lasers focus point by point, we divided the sample block into three-dimensional structure for each laser-point to discuss the relationship between the LIDT of each points and the OH-content. The result shows that the LIDT of the center of the sample block is up to 10-11J/cm2 which is consistent after the treatment while the LIDT of border pieces is 9-10 J/cm2. The different temperature and the aggradation during the fusing process and the machine process caused the different OH content of different location of the sample.

Because of its excellent optical performance, photo-physical properties, thermal stability, the fused silica is widely used in laser and aerospace industry. Fused silica can be made to the large-aperture lens for high power laser facilities or the windows for detecting devices. In order to meet the applications, the surface shape of the fused silica must be polished to better than 1/3λ(P-V). If the result of stress-birefringence is big, it is hard to control the surface shape. The permanent stress of a large-aperture fused silica was measured with digital stressmeter and analyzed from manufacturing process stand point.The forming reason and the removing way of different types of stresses were also analyzed in this article. The structure stress is the permanent one in all the types, which also affects the result and the morphology of optical homogeneity.

In this study, we describe an innovative micro-fluxgate immunosensor based on superparamagnetic Dynabeads for the detection of cardiac troponin T (cTnT), an important biomarker for cardiovascular diseases. The fluxgate sensor developed in this study uses a double layer of Co-based amorphous ribbons as a sensing element and three-dimensional solenoid copper coils to control the sensitive core. The system was fabricated through a standard micro-fabrication process, including thick photoresist lithography and electroplating. Superparamagnetic Dynabeads were employed as recognition tags and double polyclonal antibody pairs combined using streptavidin–biotin binding were employed to specifically capture and label the cTnT coupled with magnetic beads on a separate Au film-coated wafer via a classical sandwich immunoassay process. Series optimization of the assay parameters was performed to achieve optimal detection parameters. Under optimal conditions, the detection and quantification of cTnT was performed by sensing the magnetic signal of the cTnT-labeled Dynabeads with the micro-fluxgate sensor. The resulting biosystem successfully detected cTnT with satisfactory sensitivity, reproducibility, stability, and specificity. A minimum detectable limit of 0.01 ng mL−1 was achieved with a linearity range of 0.01–10 ng mL−1, demonstrating the high sensitivity of this novel system. In addition to the superior detection performance, the proposed sensor is convenient to manipulate, entirely lab-free, provides a quick result, and is portable. These factors suggest that this system has the potential to be applied as a point-of-care diagnostic tool for cardiovascular disease.

In this paper, the performance of orthogonal fluxgate sensors with meander-shaped cores is studied in fundamental mode. The meander-shaped cores are made by micro-patterning technology based on a Co-based amorphous ribbon. The main advantage of this structure is that the linear operating range of the sensor can be adjusted simply by changing the number of strips, without affecting the excitation mechanism. Experiments show that a linear range of 560 &mu, T is obtained by a meander-shaped core sensor with 12 strips. The changes in the number of strips can also increase sensitivity and reduce noise of the sensor. We can achieve a sensitivity of 600 V/T and a noise level of 0.64 nT/&radic, Hz at 1 Hz for a meander-shaped core sensor with eight strips. Compared with the performance of the sensors built using a single strip core having the same equivalent cross-sectional area, the use of meander-shaped core can provide a higher sensitivity and linearity, and a lower noise level. We also compare the performance of an eight-strip meander-shaped core orthogonal fluxgate operated in the fundamental and second-harmonic modes. Similar sensitivity for the two modes can be obtained by adjusting the excitation current. In this case, we find that the noise of sensor operating in fundamental mode is about five times lower than that of the sensor operating in second-harmonic mode. This can be interpreted as the suppression of Barkhausen noise by unipolar bias in the fundamental mode.

Manipulation of cells or bio-targets is required in a variety of biological, diagnostic and therapeutic applications. In this paper, we present a novel magnetic separator for magnetic bead labeled-target sorting in microfluidic systems. This micro magnetic separator includes 3D micro copper coil, soft magnetic tips and FeNi wires. The magnetic tips and FeNi wires are first simulated and optimized by MagNet software to increase the magnetic force exerted on magnetic beads, and fabricated by microfabrication technology. The experiment results show the sorting ratio of the magnetic beads can be up to 92.5% with the current of 200 mA and the flow rate of 5 µL/min. The maximum sorting ratio can reach 78.4% for 100 CFU/mL E. coli O157:H7 sample with the current of 200 mA and the flow rate of 0.5 µL/min. On account of the miniaturization, high sorting efficiency, low excitation current, high level of detection automation and easy integration with micro magnetic sensor, this micro magnetic separation system can be a potential application in bio-target sorting and detecting.

The authors describe an integrated microfluidic chip for immunodetection of the prostate specific antigen (PSA) by using giant magnetoimpedance (GMI) sensor. This chip contains an immunoreaction platform and a biomarker detection system. The immunoreaction platform contains an incubation chamber and a reactive chamber to implement immunological reaction in microfluidics. The system can detect PSA rapidly with ultra-high sensitivity. Both are fabricated by MEMS technology. Immunomagnetic beads (If PSA binds to its antibody (that is labeled with immunomagnetic beads; IMBs) it will be trapped on the surface of self-assembled film. Trapped IMBs generate a stray magnetic field under the magnetization of the external applied magnetic field and can be detected by the GMI sensor. The chip can detect PSA with a detection limit as low as 0.1 ng ∙ mL−1 and works in the 0.1 ng ∙ mL−1 to 20 ng ∙ mL−1 concentration range. Compared to established GMI biosensors, the magnetic microfluidic chip reduces assay time, and lends itself to fast detection. It also avoids complex handling steps, enhances reaction efficiency and decreases experimental errors.

With the continuous development of nanotechnology, people have higher and higher requirements for the performances of nanomaterials. In the past few decades, researchers have used various methods to prepare nanomaterials with different dopants, and studied their optical and electrical properties. Nanomaterials with ferromagnetic properties have a wide range of applications, and there have been many reports about the ferromagnetic properties of doped magnetic elements. However, there have been few reports about Cr-doped ZnS and CdS. In order to obtain Cr-doped ZnS and CdS nanosheets with room temperature ferromagnetism, in this paper, using ethanolamine (EA) and ethylenediamine (EN) as mixed solvents, ZnS and CdS semiconductor nanostructures doped with different amounts of chromium are successfully prepared in S, ZnO and CdO sources by simple solvent thermal method. The X-ray diffraction (XRD) measurements show that the ZnS and CdS nanostructure have a wurtzite structure. Scanning electron microscopy (SEM) images show the morphologies of ZnS and CdS with different chromium content. When the content of Cr is 4.31 at% or 7.25 at%, the thickness of Cr-doped ZnS nanosheets is about 210–290 nm, and the morphology of undoped ZnS is composed of sub-morphologies of relatively thick nanosheets. The morphologies of CdS doped with different amounts of Cr are composed of sub-morphologies of snowflake like nanosheets with thickness of about 120–190 nm. Energy dispersive spectrometer (EDS) is used to observe the product composed of Cr, Zn, Cd, and S. The EDS measurement and calculation of the Cr content in Cr-doped ZnS nanosheets are 4.31 at% and 7.25 at% respectively, and those of the Cr content in Cr-doped CdS nanosheets are 1.84 at% and 2.12 at%. The vibration sample magnetometer(VSM) measurements show that ZnS doped with chromium exhibits ferromagnetism at room temperature, while the undoped ZnS exhibits diamagnetism at room temperature. The values of saturation magnetization Ms of Cr-doped ZnS nanosheets with Cr = 4.31 at% and 7.25 at% are 2.314 and 5.683 (10–3 emu/g), and the coercivity values of Hc are 54.721 and 88.441 Oe, respectively. The ferromagnetism of pure CdS is weak, while that of Cr-doped CdS is enhanced at room temperature. The saturation magnetization Ms values of Cr-doped CdS nanosheets with Cr = 0, 1.84 at% and 2.12 at% are 0.854, 2.351 and 7.525(10–3 emu/g), respectively, and the coercivity values of Hc are 74.631, 114.372 and 64.349 Oe, respectively. The values of saturation magnetization of ZnS and CdS increases with the Cr doping increasing. The ferromagnetism of Cr-doped ZnS at room temperature is confirmed by the experimental result, which is consistent with the ferromagnetism of Cr-doped ZnS calculated by the first principle. The origin of ferromagnetism of Cr-doped CdS is related to the doping of Cr in CdS lattice.

Chromium plated cylinder has been wildly used in large bore diesel engines due to its light weight, good durability, and low induced liner wear. Deposits accumulated in the grooves and micro-crack on chromium plated cylinder could smooth the running surface, reduce the oil retention capability, and increase the engine’s oil consumption. In the present research, deposit formation on chromium-plated cylinder in fully formulated oil under different loads and temperatures was investigated by using a reciprocating sliding tester. Surface analytical techniques such as SEM, EDX, and XPS have been used to gain the knowledge about deposits’ origin, distribution, and factors affecting the deposit formation. The deposits are mainly derived from C, O, and S in the lubricating oil and anti-wear additive ZDDP (Zn and P). Deposits only accumulated in the depression (honing grooves and micro-cracks) on chromium plated cylinder surface, and there were no deposits found on the plateaus. The deposit formation increased with the increasing of load and temperature, and increased sharply over 60 MPa and 150℃. The deposit formation on liner surface was significantly different between chromium-plated coating and cast iron in component and distribution.

In order to assess various design concepts and choose a kind of covering cap design scheme which can meet the requirements of airworthiness standard and ensure the safety of fuel tank. Using finite element software ANSYS/LS- DYNA, the impact process of covering cap of aircraft fuel tank by projectile were simulated, in which dynamical characteristics of simple single covering cap and gland double-layer covering cap impacted by titanium alloy projectile and rubber projectile were studied, as well as factor effects on simple single covering cap and gland double-layer covering cap under impact region, impact angle and impact energy were also studied. Though the comparison of critical damage velocity and element deleted number of the covering caps, it shows that the external covering cap has a good protection effect on internal covering cap. The regions close to boundary are vulnerable to appear impact damage with titanium alloy projectile while the regions close to center is vulnerable to occur damage with rubber projectile. Equivalent strain in covering cap is very little when impact angle is less than 15°. Element deleted number in covering cap reaches the maximum when impact angle is between 60°and 65°by titanium alloy projectile. While the bigger the impact angle and the more serious damage of the covering cap will be when rubber projectile impact composite covering cap. The energy needed for occurring damage on external covering cap and internal covering cap is less than and higher than that when single covering cap occur damage, respectively. The energy needed for complete breakdown of double-layer covering cap is much higher than that of single covering cap.

This paper investigated the directional migration behavior of the alloying elements in the rafting process of the single crystal superalloy DD6 with [001] orientation under 300 MPa at 1000 °C. The microstructure of the single crystal superalloy DD6 was acquired by SEM. The results indicate that the rafting direction of γ ' phase is nearly perpendicular to stress axis. The matrix channel running parallel to the stress axis gets wider, but it will fade away gradually in vertical direction. Statistical analysis of the alloy components by TEM reveals the directional migrations of the elements Al, Re and W in the single crystal superalloy DD6. The element Al spreads to the matrix channel which is parallel to the stress axis, while Re and W diffuse to the matrix channel which is perpendicular to the stress axis, and obviously concentrate in the crossing area of the above mentioned channels.

Optical homogeneity of the optical materials directly affects the wavefront quality of the refractive optical system. There are some difficulties of testing large caliber optical materials, four-step method of Fizeau interferometry is a convenient and accurate method for measuring optical homogeneity. The article used the four-step method test the same quartz glass sample in a cavity with different precision and found that the optical homogeneity test results have a larger gap. While this article compared the effect of the fixed cavity surface shape and the changing cavity surface shape on 300 mm diameter quartz glass optical homogeneity test and analyzed the effect of different positions of fixed cavity distortion on optical homogeneity testing.

Synthetic quartz glass is an excellent transmittance material in ultraviolet (UV), visible and near-infrared bands. Homogenization process to synthetic quartz glass optical elements is done in order to make the composition and structure more uniform. The homogenization temperature is above 1800°C. After high-temperature homogenization, the UV transmittance of quartz glass appears a certain extent of decline in the edge partition., After high temperature homogenization process, it is found that the closer the layer to the graphite vessel, the stronger influence on UV transmittance will be. This conclusion is made by comparing the UV transmission of the quartz glass in different layers. Furthermore, the factors affecting the UV transmittance is also analyzed in this article.

The corrosion behaviour and passive films formed on Ni-based single crystal superalloys with different orientations were investigated through the electrochemical testing and microstructural analysis. The results show that the corrosion rates of the different planes increases in the order of (001)

We report an innovative integrated microfluidic platform based on micro-fluxgate and micro-coils for trapping and detecting magnetic beads. A micro-spiral coil fabricated by microfabrication technology is used to trap the magnetic beads, and the micro-fluxgate is employed to detect the weak magnetic field induced by the trapped magnetic beads. The fabrication process of the magnetic bead trapping system using a micro-coil is highly compatible with that of the micro-fluxgate sensor, making fabrication of this integrated microfluidic system convenient and efficient. It is observed that the magnetic bead trapping ratio increases as the number of magnetic beads is increased with a flow rate of 5 to 16.5 μL·min

We present a novel integrated microfluidic platform based on micro-magnetic sensor for manipulating and detecting magnetic beads (MB). A micro-spiral planar coil in MB manipulating system microfabricated by micro-electro-mechanical system technology is implemented to manipulate MB, and a giant magnetoimpedance (GMI) based micro-magnetic sensor is employed to detect the trapped MB. In our work, MB can be efficiently trapped by trapping force generated from micro-coil in microchannel. Next, trapped MB are detected by the changing ratio of impedance, as well as the variation of resistance and reactance in GMI sensor for trapped MB induce weak stray magnetic field under the magnetization by external magnetic field. The maximum difference of GMI ratio between with beads condition and without beads condition is 4.0% at the optimum driving frequency of 20 MHz under the external magnetic field of 15 Oe, and resistance ratio varies more significantly than reactance ratio. In comparison with traditional MB detecting methods by GMI sensor, the integrated microfluidic platform based on GMI sensor can not only manipulate and detect MB signal sensitively, but also enhance detection efficiency and decrease the experiment errors. Furthermore, this platform avoids contamination from the solutions in chemically reactive layers and reduces assay time in future biomarker detection. In our work, the microfluidic platform based on GMI sensor has potential applications in biomarker detection via MB manipulation and detection.

A sensitive and innovative assay system based on a micro-MEMS-fluxgate sensor and immunomagnetic beads-labels was developed for the rapid analysis of C-reactive proteins (CRP). The fluxgate sensor presented in this study was fabricated through standard micro-electro-mechanical system technology. A multi-loop magnetic core made of Fe-based amorphous ribbon was employed as the sensing element, and 3-D solenoid copper coils were used to control the sensing core. Antibody-conjugated immunomagnetic microbeads were strategically utilized as signal tags to label the CRP via the specific conjugation of CRP to polyclonal CRP antibodies. Separate Au film substrates were applied as immunoplatforms to immobilize CRP-beads labels through classical sandwich assays. Detection and quantification of the CRP at different concentrations were implemented by detecting the stray field of CRP labeled magnetic beads using the newly-developed micro-fluxgate sensor. The resulting system exhibited the required sensitivity, stability, reproducibility, and selectivity. A detection limit as low as 0.002 μg/mL CRP with a linearity range from 0.002 μg/mL to 10 μg/mL was achieved, and this suggested that the proposed biosystem possesses high sensitivity. In addition to the extremely low detection limit, the proposed method can be easily manipulated and possesses a quick response time. The response time of our sensor was less than 5 s, and the entire detection period for CRP analysis can be completed in less than 30 min using the current method. Given the detection performance and other advantages such as miniaturization, excellent stability and specificity, the proposed biosensor can be considered as a potential candidate for the rapid analysis of CRP, especially for point-of-care platforms.

Numerical calculations have been performed to study the creep damage evolution of nickel-based single crystal specimens with slant-angled film cooling holes. The emphasis is the effect of different slant angles on creep properties. The slant angles are 0°, 15°, 30° and 45°. The results show that the distributions of the resolved shear stress around film holes are different under different slant angles. The directions of crack propagation are θ =±54° when α =0°, 15°, 30°; however when α =45° the crack propagation directions are along θ =±46°. The specimen with α =30° has the longest failure life. In the higher stress region near the cooling hole, the phenomenon of stress relaxation will appear, such as resolved shear stress, Mises equivalent stress and stress σ 11 . And with the time increasing, they reach stable values. Different specimens have different damage distributions. The maximum damage points appear at locations 0°, 0°, 13° and 26° from horizontal direction when the slant angles are 0°, 15°, 30° and 45°, respectively. And thickness has influence on the distribution of resolved shear stress along the holes.

An all-solid-state Cr:LiSAF laser with a grating-controlled coupled-cavity for dual-wavelength operation is demonstrated. One wavelength is decided by the main-cavity oscillation and fixed at 860 nm. The other wavelength can be tuned from 790 nm to 987 nm by the grating in the coupled cavity. The maximum output power is 10 mW and both the linewidths are narrowed to below 0.2 nm.

High temperature tensile tests of nickel-based superalloy GH3230 were carried out at various strain rates from 10−3 s−1 to 10−1 s−1 over temperature range from 1144 K to 1273 K. The emphasis has been put on the effect of strain rate and temperature on the plastic flow stress. The results show that flow stress increases and the hardening exponent n decreases with the strain rate increasing or temperature decreasing. The strain rate sensitivity exponent m is a constant independent of temperature according to the interdependencies of flow stress, strain rate and temperature. The thermal deformation activation energy of GH3230 was calculated as 441 kJ/mol. The full recrystallization will occur when the temperature is about 1273 K and the microstructures with uniform and fine grains can be obtained. The SEM result shows that the fracture mode of all specimens is micro-porous aggregation ductile fracture caused by damage, the variation of temperature has not much effect on fracture morphology at various temperatures, but fracture dimple becomes deeper and larger while the strain rate decreasing.

This paper reports a novel micro-fluxgate sensor based on a double-layer magnetic core of a Fe⁻Co⁻B-based amorphous ribbon. The melt-spinning technique was carried out to obtain a Fe⁻Co⁻B-based amorphous ribbon composite of Fe58.1Co24.9B16Si₁, and the obtained amorphous ribbon was then annealed at 595 K for 1 h to benefit soft magnetic properties. The prepared ribbon showed excellent soft magnetic behavior with a high saturated magnetic intensity (Bs) of 1.74 T and a coercivity (Hc) of less than 0.2 Oe. Afterward, a micro-fluxgate sensor based on the prepared amorphous ribbon was fabricated via microelectromechanical systems (MEMS) technology combined with chemical wet etching. The resulting sensor exhibited a sensitivity of 1985 V/T, a wide linearity range of ±1.05 mT, and a perming error below 0.4 μT under optimal operating conditions with an excitation current amplitude of 70 mA at 500 kHz frequency. The minimum magnetic field noise was about 36 pT/Hz1/2 at 1 Hz under the same excitation conditions; a superior resolution of 5 nT was also achieved in the fabricated sensor. To the best of our knowledge, a compact micro-fluxgate sensor with such a high-resolution capability has not been reported elsewhere. The microsensor presented here with such improved characteristics may considerably enhance the development of micro-fluxgate sensors.

The surface morphology of quartz glass etched in HF acid is influenced by many factors, such as the quality of polishing, types of the quartz glasses, metal ion in HF acid, etc. This paper conducted an analysis on these factors and tried to make improvements. Meanwhile, this experiment approved of the model of both destructive layer and the varying of closed micro-cracks in the process of etching. Besides, the changing law of both ditch-like and pit-like flaws was investigated in this experiment, and conclusions could be drawn as follows: at the concave curvature, the bigger the radius of curvature is, the faster the etching will be; The etching rate with protruding curvature is higher than that of concave curvature; The etching rate with concave curvature is lower than that on the plane surface.

Optical homogeneity is an important measurement of the optical materials, directly affects wavefront quality of the refractive optical system, changes the system wavefront aberration. As the traditional direct measurement method requires high precision surface shape machining for optical material (PV value < 0.1λ), it was gradually replaced by the method of Fizeau interferometer four step, which requires lower surface shape. This article used 600mm diameter Fizeau interferometer, a four step method tested the optical homogeneity of the same 500 mm diameter fused quartz material with a front surface shape respectively 3.719 λ and 0.427 λ (λ = 632.8nm). Comparison of the test results showed that the PV difference of optical homogeneity between the two was only 0.036 λ, △n inaccuracy was 10-7, and the homogeneity morphology matched exactly. To further analyze the factors affecting the optical homogeneity, the front surface shape of the other sample was sliced ​​in a predetermined direction. This artical analyzed the effect of morphology upon the slicing line on optical homogeneity. The conclusion was that the direct affecting factor on optical homogeneity was the slope of surface morphology, rather than the overall PV value.

This work is focused on the preparation and properties of ternary fatty acid eutectic mixtures/ expanded graphite form-stable phase change materials (PCMs). Based on the theoretical calculation of the mass ratio and ternary eutectic melting temperature, the ternary eutectic mixture of capric acid (CA), lauric acid (LA) and palmitic acid (PA) was prepared firstly, which is for the sake of decreasing the phase transformation temperature. Thermal characteristics such as melting temperature and latent heat of fusion of these developed eutectics measured by using Differential Scanning Calorimetry (DSC) technique, which also showed that the eutectic mixture was composed by CA, LA and PA in the mass ratio of 59.7:30.1:10.02. Then the CA–LA–PA was absorbed in expanded graphite (EG), which acts as a supporting material, the optimum mass ratio of CA–LA–PA to EG is 17:1. The CA–LA–PA/EG composites were characterized by the scanning electronic microscope (SEM), differential scanning calorimeter (DSC). The SEM observations showed that the CA–LA–PA was adsorbed into the porous structure of EG, instead of any chemical action. The DSC results indicated that the phase change temperature and latent heat of the CA–LA–PA and CA–LA–PA/EG were 19.92 °Cand 19.48 °C, and 135.49 J/g and 130.73 J/g respectively. The thermal conductivity of CA–LA–PA /EG composite PCM was improved by the high thermal conductivity of the EG. Thermal cycling test showed that the CA–LA–PA/EG composite had a good thermal reliability. All results indicated that CA–LA–PA/EG composite PCM has a proper melting temperature and latent heat for building energy conservation.

The polyanion of copolymer poly (2-methacryloyloxyethyl phosphorylcholine-co-methacrylic acid) (PMA30) was synthesized by free radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid (MA). The synthesized PMA30 was assembled on chitosan (CS) surfaces formation of chitosan nanoparticles by polyionic complex. The chitosan nanoparticle was prepared using methacrylic acid (MA), 2-methacryloyloxyethyl phosphorylcholine (MPC) by template polymerization. The size distribution and structure properties of chitosan nanoparticles were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential. These results show that a cell outer membrane mimetic surface was formed on the chitosan nanoparticles, which provides an effective way to improve the biocompatibility of chitosan nanoparticles.

This paper presented the influence of crystallographic orientation and friction coefficient on the contact stress and fatigue life in the tenon/groove contact region. A rate-dependent crystallographic plastic slip theory was used to calculate the contact stress and fatigue life in [001], [011] and [111] orientations. In the calculation, complex loading conditions and different friction coefficients of 0, 0.2, 0.4, 0.6, 0.8 and 1.0 were taken into account in tenon/groove. Then the relationship between contact stress, fatigue life and friction coefficient was discussed. Simulation results show that: friction coefficient and crystallographic orientation have significant effect on contact stress and fatigue life. Contact stress in [001], [011] and [111] orientation increases with increasing friction coefficient generally. For [001] and [011] orientation, the fatigue life decreases with increasing friction coefficient firstly. When friction coefficient is 0.4, the fatigue life meets its minimum. Then the fatigue life will increase with increasing friction coefficient. For [111] orientation, the change of fatigue life has no obvious trend, and while friction coefficient exceeds 0.6, the life almost constant.

Anti-lightning strike protection for composite structures is catching great attention to design optimum lightning protection solution. Based on lightning direct effect, optimizations of flame spraying aluminum thickness and composite laminate plies were conducted by combining electrical-thermal analysis procedure and corresponding optimization programs. Optimized thickness was acquired for flame spraying aluminum layer. Meanwhile, non-uniform thick plies and optimized stacking angles were given for anti-lightning strike composite laminate. Comparisons were conducted to investigate changes of lightning direct effects on composite laminates fore and after optimization. Synergetic protections of flame spraying aluminum and laminate plies design were listed. The conclusions can be used as suggestions for lightning strike protection of advanced aircraft.