针叶木浆磨浆过程中浆料的流动、纤维受力及形变

分析了磨浆过程中浆料的流动形式,磨齿作用力,纤维受力、形变和相应的磨浆效果,探讨了磨齿前刃对纤维的作用力,讨论了纤维切断、纤维分层和内部细纤维化、纤维"剥皮"及表面细纤维化的原因。

木质纤维表面特性与纤维间结合性能的响应关系

木质纤维原料的表面性能直接影响着纤维之间的结合性能,进而影响纸页结构及其物理性能。综述了纤维的电荷特性、形变性以及纤维的表面自由能三种表面性能的评价方法,并探究每一种纤维自身性能与纤维间结合性能的响应关系。

试论丝绸文物塑性形变机理与恢复技术

分析发现,丝绸文物的形变源自纤维在外力或环境因素作用下产生的形变,其形变可分为急弹性、缓弹性和塑性形变,其中塑性形变是因外力负荷大且作用时间长而形成的无法自行恢复的形变。通过提升纤维的吸湿水平,可以提升纤维形变回弹率,回弹率的增加意味着纤维塑性形变恢复的可能性增加。本文对利用纤维湿度调节技术,恢复丝绸文物形变的技术操作进行了探索。

Study on High Strength Concrete Confined by Continuous Carbon Fiber Sheet

Eight high strength concrete (HSC) prisms strengthened with continuous carbon fiber sheet(CFS)were tested.As a result of the confinement provided by CFS,the concrete would fail at a greater strain than the unconfined and then a significant increase in ductility can be achieved.The lateral pressure exerted by CFS would increase the compressive strength of the concrete,resulting in higher load bearing capacity.This paper proposes the stress strain curve of this kind of hybrid specimen,which agrees well with the test results.Based on the stress strain relationship and the assumptions proposed in this paper,a computer program was developed to analyze HSC columns,confined by CFS,which were subjected to axial compression and biaxial bending.The results shown in this paper indicate that the ductility of HSC column is significantly improved and the strength is also increased by some degree.

基于眼动技术的TMA界面评估及优化

利用眼动追踪技术对胶原纤维热形变分析仪TMA用户界面进行可用性评估,提出一种优化设计方案。以现有的胶原纤维热形变分析仪TMA界面为原型,通过专家指导,选定4个设计要素,重新设计了2款风格不同的用户界面,进行眼动实验,采集眼动数据,利用SPSS进行数据分析,结合问卷调查,对用户界面的背景颜色和布局类型进行可用性评估。胶原纤维热形变分析仪的用户界面背景颜色和布局类型均会影响受试的用户体验,T型布局在各方面均优于上下框架型布局。该方案提出了实验仪器用户界面的设计原则,优化了设计师依靠经验主观设计原版界面的不足,可为实验类仪器界面设计提供参考思路,进一步提升设计方案的科学性、合理性。

Deformation behavior of high performance fiber reinforced cementitious composite prepared with asphalt emulsion

A novel engineered cementitious composite(ECC) was prepared with the complex binder of Portland cement and asphalt emulsion.By adjusting the amount of asphalt emulsion,different mixture proportions were adopted in experiments,including four-point bending test,compressive test,and scanning electric microscopy(SEM).The SEM observation was conducted to evaluate the contribution of polyvinyl alcohol(PVA) fiber and asphalt emulsion to the composite toughening mechanism.The tests results show that the most remarkable deflection-hardening behavior and saturated multiple cracking are achieved when the content of asphalt emulsion is 10%.However,excessive content of asphalt emulsion causes severe damages on the deformation behavior as well as loss in compressive strength of the mixture.SEM observation indicates that the influence of asphalt emulsion on the fiber/matrix interfacial property changes the dominant fiber failure type from rupture into pull-out mode,and thus causes beneficial effects for strain-hardening behavior.

Is portal vein cavernous transformation a component of congenital hepatic fibrosis?

Congenital hepatic fibrosis (CHF) is an autosomal recessive disorder that belongs to the family of fibropolycystic liver diseases. This family includes a spectrum of disorders which are usually found in combination with each other and are usually inherited. Clinically fibropolycystic diseases have three effects being present in different proportions, those of a space occupying lesion, of portal hypertension and of cholangitis. In most patients, the first manifestations of CHF are signs and symptoms related to portal hypertension such as splenomegaly and varices. Portal hypertension in these patients has been attributed to the hypoplasia or compression of the portal vein radicles in the fibrous bands. Cavernous transformation of the portal vein (CTPV) is a relatively rare condition resulting from extrahepatic portal vein obstruction with recanalization or collateral vein formation to bypass the obstruction. It has been found that patients with CHF having an accompanying CTPV have relatively large splenomegaly and suffers more frequent episodes of bleeding from esophageal varices.We believe that CTPV is a congenital component of CHF and also one of the important causative factors of portal hypertension in these patients.

cytoplasmic domain of tissue factor promotes liver fibrosis in mice

To evaluate the role of tissue factor (TF) and protease activated receptor (PAR)-2 in liver fibrosis. METHODSUsing CCl4 administration for eight weeks, we induced hepatic fibrosis in wild-type C57BL/6 mice and in mice with deletion of the cytoplasmic signalling domain of TF (TF§CT/§CT), deletion of PAR-2 (PAR-2-/-) and combined deletion of TF signalling domain and PAR-2 (TF§CT/§CT/PAR-2-/-). Hepatic fibrosis area was assessed by quantitative imaging of picrosirius red staining. Hepatic collagen content was assessed by hydroxyproline levels. Hepatic stellate cells (αSMA positive) and hepatic macrophages (CD68 positive) were identified by immunohistochemistry. Hepatic gene expression was determined by PCR and liver TGFβ1 content by ELISA. RESULTSCCl4 treated mice with deletion of the PAR-2 gene (PAR-2-/-) and the cytoplasmic domain of TF (TF§CT/§CT) developed significantly less hepatic fibrosis, characterised by reduced liver fibrosis area and hydroxyproline content, compared to control wildtype mice treated with CCl4. The observed reduction in histological fibrosis was accompanied by a significant decrease in the hepatic content of TGFβ, the prototypic fibrogenic cytokine, as well as fewer activated hepatic stellate cells and hepatic macrophages. Deletion of the TF cytoplasmic signalling domain reduced hepatic fibrosis to levels similar to those observed in mice lacking PAR-2 signalling but combined deletion provided no added protection against fibrosis indicating a lack of mutual modulating effects that have been observed in other contexts such as angiogenic responses. CONCLUSIONTissue factor cytoplasmic domain is involved in TF-PAR-2 signalling initiating hepatic fibrosis and is a potential therapeutic target, as its deletion would not impact coagulation.

Temperature dependence of microstructure and texture in cold drawn aluminum wire

The effect of strain and drawing temperature on the evolution of microstructure and fiber textures of aluminum wiresdrawn at room temperature and cryogenic temperature was investigated by TEM and EBSD observations.The results show that lowangle boundaries frequency increases and high angle boundaries frequency decreases with strain increasing when the strain is low.Athigh strain,most of grain and dislocation boundaries are parallel to the drawn direction and low angle boundaries frequencydecreases and high angle boundaries frequency increases with strain increasing.The decrease of deformation temperature leads tomicrostructure finer and low angle boundaries frequency increasing.Texture analysis indicates that volume fraction of complextexture component decreases with strain increasing and a mixture of?111?and?100?fiber texture forms at high strain.?111?is stableat low strains but?100?becomes stable at high strain.The decrease of temperature can enhance the stability of?111?orientation athigh strain.

The effect of heat treatment on the structure and morphology of poly （p-phenylene benzobisoxazole） fiber

The effect of heat treatment on the structure of Poly（p-phenylene benzobisoxazole） （PBO） fiber was studied by wide angle X-ray diffraction （WAXD） and differential scanning calorimetry-（DSC）, which resuits in confirmation of secondary crystallization in the heat treatment process. The effect of heat treatment on the structure and morphology of PBO fiber＇ s surface was investigated with X-ray photoelectron spectroscopic analysis （XPS）, scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The results show that heat treatment not only has an effect on the composition of PBO fiber＇s surface, but also improves the microstmcture of PBO fiber, makes fiber more regular.

Yarn Architecture Analysis of Two-step 3D Braided Composites

A comprehensive study of yarn architecture of two-step rectangle 3D braided composites is presented. Firstly, the braided surface, the shapes of yarns and the intertwining between braider yams and axial yams are analyzed from experimentation. With the microstructure being defined, three levels of unit cell structure are identified, i.e. large unit cell, second unit cell and minimal unit cell. Secondly, based on the minimal unit cell in the interior and on the boundary of the entire cross-section, the deformations of axial yams squashed by braider yams contribute to the increase of the fiber packing factors of axial yams. Finally, the predicted fiber volume fraction of the composites decreases with the increase of linear density of the braider yam and the pitch length. Favorable correlations between the predicted and the experimental results arc found for six groups of the composites.

Propagation characteristics of six-core photonic liquid crystal fibers

We demonstrate a new kind of multi-core photonic liquid crystal fibers (PLCFs) which have six liquid crystal cores arrayed in the ring-type geometry and separated by the air holes. Through analyzing the structure of this kind of PLCFs, it can be found that they have the ability to resist the structure deformation. Due to the effective index of the liquid crystal can be adjusted by temperature and wavelength, the energy in the six liquid crystal cores is increased with the temperature increasing and wavelength decreasing. The effective index of the PLCFs is decreased, the effective fundamental mode area is increased and the dispersion properties are gently affected with the wavelength increasing and temperature decreasing.