钢丝类打捆机线结强度与成形条件的实验研究

影响钢丝类打捆机线结强度的因素有很多方面 ,通过实验的方法就总扭结角度、捆线材料。

Influence of expanded polystyrene size on deformation characteristics of light weight soil

Deformation characteristics of light weight soil with different EPS (expanded polystyrene) sizes were investigated by consolidation tests.The results show that the confined stress-strain relation curve is in S shape,which has a good homologous relation with e-p curve and e-lgp curve,and three types of curves reflect obvious structural characteristics of light weight soil.When cement mixed ratio and EPS volume ratio are the same for different specimens,structural strength decreases with the increase of EPS size,but compressibility indexes basically keep unchanged within the structural strength.The settlement of light weight soil can be divided into instantaneous settlement and primary consolidation settlement.It has no obvious rheology property,and 90% of total consolidation deformation can be finished in 1 min.Settlement-time relation of light weight soil can be predicted by the hyperbolic model.S-lgt curve of light weight soil is not in anti-S shape.It is proved that there is no secondary consolidation section,so consolidation coefficient cannot be obtained by time logarithm method.Structural strength and unit price decrease with the increase of EPS size,but the reducing rate of the structural strength is lower than that of the unit price,so the cost of mixed soil can be reduced by increasing the EPS size.The EPS beads with 3-5 mm in diameter are suggested to be used in the construction process,and the prescription of mixed soil can be optimized.

Thermal decomposition and mechanical properties of hydroxyapatite ceramic

Pure hydroxyapatite（HAP）ceramic and HAP composite ceramic with B2O3 were prepared by isostatic press forming and pressureless sintering.The relationships between thermal decomposition ratio and mechanical properties for pure HAP ceramic and the composite ceramic were investigated by means of FTIR,X-ray diffraction and three-point bending method.The results indicate that the decomposition ratio of pure HAP ceramic increases with ascending the sintering temperature and nearly reaches 80%at 1 350？殆or the HAP composite ceramic,the thermal decomposition is inhibited obviously due to the addition of B2O3.The added B atoms incorporate into the crystal lattice of HAP to form solid solution,resulting in an enlargement in the crystal spacing and an improvement in the binding strength of HAP crystal cell.Thermal decomposition ratio of HAP decreases but bending strength and fracture toughness are enhanced for HAP composite ceramics.However,when the added B2O3 is more than 5%（mass fraction）,HAP decomposition is promoted and a steady？-TCP is formed due to the fact that when B atoms with higher negative electricity are combined with O,sp2 and a full-air p are formed,and those voids have a strong trend to intake of the outer electrons.So,it is very possible to occupy the place where HAP loses OH - or PO4 3- .

Meso-structure and fracture mechanism of mudstone at high temperature

The meso-structure mineral composition and fracture mechanism of uniaxial compressed mudstone samples at high temperature were analyzed by XRD and scanning electron microscopy. The effect of tem- perature on mudstone composition and fracture mechanism were studied from a meso-structural per- spective, and the relationship between meso-structure and macro-mechanical characteristics at high temperature was revealed. The findings demonstrated that the fluctuation in diffraction intensity of kao- linite in the mudstone caused the fluctuation in its mechanical properties. The overall structure under- went a phase change around 600℃, which led to the sudden change in the mechanical properties of mudstone samples. When the temperature reached 600 ℃, the crystalline state worsened and kaolinite disappeared; however, some illite was produced, indicating that the chemical reaction of the structure and sudden drop of bearing capacity of the mudstone. Mudst0ne fracturing at high temperature involves mainly intergranular and transgranular fractures, which are typical in micro-brittle tensile failure. Con- sidering the macro-fracture characteristics of mudstone, the results suggested that macro-fracture under external force corresoonds to the meso-fracture.

MR Imaging Features of Solitary Plasmacytoma of the Spine

OBJECTIVE To evaluate the MR imaging features of solitary plasmacytomas of the spine. METHODS The MR images of 7 patients with histologically proven solitary plasmacytomas of the spine were reviewed. RESULTS All tumors showed predominantly isoto hypointensity relative to muscle on Tl-weighted MR images and intermediate signal intensity between muscle and fat on T2- weighted images. Curvilinear low signal intensity structures were seen within the lesions on T1 and T2-weighted images in five tumors. Moderate to strong enhancement was seen in all 6 tumors that underwent contrast enhanced MR examination. All tumors showed areas of high signal intensity on T2-weighted images and heterogeneous enhancement, except the 2 largest tumors without pathologic fracture in the sacrum. Intervertebral discs were preserved in all tumors. CONCLUSION The MR imaging features that suggest plasmacytorna of the spine include predominant intermediate signal intensity on T2-weighted images, curvilinear low signal intensity structures, moderate to strong enhancement, relatively homogeneous appearance if there are no pathologic fracture and preservation of the intervertebral discs.

Independent dual-responsive Janus chromic fibers

Daily exposure under solar ultraviolet(UV)and infrared(IR)is prone to cause skin cancer and photoaging.Real-time monitoring of the environmental UV index and IR radiation temperature during outdoor activities can enhance awareness and strengthen personal protection.It is a challenge to design flexible,wearable devices(with measurement capabilities)that can be integrated with apparels.Here,microfluidic spinning technology(MST)was used for the continuous and large-scale fabrication of eco-friendly coresheath Janus fibers with a well-defined axially symmetric Janus core.One side of the core was sensitive to UV light and the opposite was sensitive to IR radiation.Textiles woven with Janus fibers showed excellent independent reversible color responses to dual-wavelength stimulation.Such textiles switched among four colors under UV and IR irradiation,both individually and in combination.The color gradient of the textiles changed significantly with increasing UV intensity(UV index).After 60 cycles of UV/IR stimulation and 50 washes,the change rate of the comprehensive chromatic aberration(ΔE_(ab)^(*))of the textiles under different conditions was only 0.42%-4.71%.This was attributed to the unique structure of the fibers.The three-line striped textiles demonstrated the potential of the fibers to be used as wearable energy-free realtime visual monitors of the UV index and IR radiation temperature.