ABS/PETG合金的制备与性能

采取熔融共混、双螺杆挤出的工艺方法制备ABS/PETG合金。采用DSC测试合金材料的相容性能,采用挤出式毛细管流变仪测定ABS/PETG合金的流变性能,采用电子万能实验机和冲击实验机测试了合金的拉伸性能和冲击性能。结果表明,ABS/PETG合金属于部分相容体系,当ABS/PETG配比为40/60时,合金相容性较好。在215℃至240℃温度范围内,ABS/PETG合金表现出假塑性流体的流动行为。增容剂PE—g—MAH可显著增强增韧ABS/PETG合金,当PE-g-MAH含量为1%时,ABS/PETG合金的拉伸强度和冲击强度分别由原来的48.56 MPa和116.7 KJ/m2提高到50.38 MPa和361.7 KJ/m2。

高强度与高性能混凝土有关问题的论述

介绍高强度与高性能混凝土和普通混凝土性能特征的区别。对配制混凝土原材料的质量要求,水泥、外加剂与掺合料等组成的相容性及相互作用的问题进行论述。介绍加掺合料,最大限度地减少水泥用量降低水化热、改善混凝土的施工性能、减少收缩与裂缝、提高混凝土的耐久性等问题的研究成果。提出高强度与高性能混凝土的质量控制、质量评定及解决质量问题的一些技术措施。

香精微胶囊与再生纤维素的相容性

芳香型再生纤维素纤维是利用再生纤维素与香味精油或香料融合,制成纺丝原液,然后进行纺丝制得芳香型再生纤维素纤维。采用β-环糊精对香精分子进行包覆制得β-环糊精/香精微胶囊来改善香精与再生纤维素的相容性,将制得的微胶囊放在尼康显微镜及扫描电镜下观察并测试其相容性能。结果表明:香精微胶囊在100℃沸水、酸性条件和碱性条件下颗粒没有明显的变化,说明其具有良好的热稳定性、耐酸性及耐碱性,适合生产芳香型再生纤维素纤维。

载P/Ag微结构Ti表面的生物学性能和抗菌性能

钛(Ti)是医用临床中广泛使用的金属植入材料,但由于其生物惰性及无抗菌性,导致植入手术失败的案例时有发生。本文在Ti表面构建了一种新型的、含P、Ag的微结构,以赋予植入材料良好的生物学性能和抗菌性能。首先通过阳极氧化技术在Ti表面制备载P的微结构,然后通过离心和紫外光辐照的技术将Ag引入到Ti表面。然后采用模拟体液浸泡试验(SBF)评价改性Ti表面的生物活性,通过体外细胞培养试验考察其细胞相容性,采用菌落数法测试其对大肠杆菌的抑制效果。结果表明,P、Ag和微结构的引入使得Ti表面可诱导类骨磷灰石形成,促进细胞在其表面的黏附和增殖,抑制细菌的生长。基于以上结果,可以证实本文研制的载P/Ag微结构Ti表面作为植入材料具有良好的应用前景。

沥青改性再生剂制备与其性能研究

为提高再生沥青混合料的性能,优选沥青再生剂基础油分、增塑剂、增黏剂以及增容剂,制备改性再生剂,并对改性再生剂的再生性能、扩散性能,与老化沥青的相容性能及再生沥青的抗二次老化性能进行试验。结果表明,再生性能方面,改性再生剂再生沥青的三大指标性能均优于普通再生剂再生沥青,且改性再生剂再生沥青更为节约再生剂掺量。扩散性能方面,提出一种根据扩散性能指标系数的新型方法检测再生剂扩散性能,并得到改性再生剂的扩散性能指标系数K为12.088,均高于再生剂B、C、D的9.856、9.779、9.615。相容性能方面提出相容度P指标进行评价,计算得到改性再生剂的相容度P为71.2%,均优于再生剂B、C、D的42.7%、45.6%、50.1%。再生沥青抗二次老化方面,得到改性再生沥青在模拟服役8~12年后的性能评价指标优于普通再生沥青模拟服役5~8年后的性能评价指标。

Laser processing effects on Ti−45Nb alloy surface,corrosive and biocompatible properties

The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatment,(Ti,Nb)O scale was formed and various morphological features appeared on the alloy surface.The electrochemical behavior of Ti−45Nb alloy in simulated body conditions was evaluated and showed that the alloy was highly resistant to corrosion deterioration regardless of additional laser surface modification treatment.Nevertheless,the improved corrosion resistance after laser treatment was evident(the corrosion current density of the alloy before laser irradiation was 2.84×10^(−8)A/cm^(2),while that after laser treatment with 5 mJ was 0.65×10^(−8)A/cm^(2))and ascribed to the rapid formation of a complex and passivating bi-modal surface oxide layer.Alloy cytotoxicity and effects of the Ti−45Nb alloy laser surface modification on the MRC-5 cell viability,morphology,and proliferation were also investigated.The Ti−45Nb alloy showed no cytotoxic effect.Moreover,cells showed improved viability and adherence to the alloy surface after the laser irradiation treatment.The highest average cell viability of 115.37%was attained for the alloy laser-irradiated with 15 mJ.Results showed that the laser surface modification can be successfully utilized to significantly improve alloy performance in a biological environment.

Effect of graphene oxide with different oxidation degrees on mechanical properties of styrene-butadiene rubber: Experiment and molecular simulation

Graphene oxide(GO)has proven to be an effective reinfor-cing filler for rubber[1].GO has superior mechanical properties,barrier properties,large specific surface area and abundant oxygen-containing functional groups[2].However,the change in the oxidation degree of GO has a great effect on its chemical properties,the interaction between GO and the matrix,and the dispersion uniformity in the rubber matrix,which has a great effect on the reinforcement of rubber[3].

对SBS改性沥青试验中异常现象的研究

对星型 SBS改性沥青进行研究 ,通过与其它类型改性沥青对比 ,讨论了 SBS改性沥青试验过程中的异常现象 ;在试验和分析的基础上 ,对改性沥青的相容性作了澄清和说明 ,提出了性能相容和储存稳定性相容的概念。

In vitro corrosion and biocompatibility of phosphating modified WE43 magnesium alloy

Phospahting coated WE43 magnesium alloy was prepared by an immersion method. The microstructure, corrosion resistance and biocompatibility of the coated alloy were investigated. Scanning electron microscopy （SEM） and X-ray diffraction （XRD） were used to examine the microstructure and the composition of the coated alloy. The corrosion resistance was studied by means of potentiodynamic polarization method and the biocompatibility of the surface modified WE43 alloy was evaluated by （3-（4,5）-Dimethylthiazol-2, yl）-2,5-diphenyltetrazolium bromide （MTT） and hemolysis test. The results show that the phosphating coating can enhance the corrosion resistance of WE43 alloy and can be a good candidate to increase the biocompatibility of WE43 alloy.

Surface modification with SiO_2 coating on biomedical TiNi shape memory alloy by sol-gel method

The effect of heat treatment on the transformation temperature of Ti?52.2%Ni (mole fraction) alloy was studied using differential scanning calorimetry (DSC). The transformation temperatures of the alloy can be adjusted effectively by heat treatment. Dense and stable SiO2 coatings were deposited on the surface of the pre-oxidized TiNi alloy by sol?gel method. The bonding strength of films and matrix was (65.9±1.5) N. The electrochemical corrosion test shows that the TiNi alloy with SiO2 coating has excellent corrosion resistance in the Hank’s simulated body fluid. The release behaviors of Ni ion of the alloy with and without SiO2 coating implanted in the acoustic vesicle of guinea pig were studied by EDS testing, which was inhibited effectively by the dense and stable SiO2 coating on the alloy.

链的柔顺性对高分子交联网溶胀及相分离影响

通过对高分子极稀溶液体系得到的高分子交联网络进行理论计算 ,分析了高分子链的柔顺性对高分子交联网在溶剂或增塑剂中的溶胀及体系相分离影响 .并对非极性高分子交联网的相分离条件进行了分析 .结果表明 :在网状交联体系中溶剂的平衡浓度比线性高分子溶液的高 ;随着链的柔顺性提高 。

Microwave dielectric properties and compatibility with silver of low-fired Li_2MgTi_3O_8 ceramics with Li_2O-MgO-B_2O_3 frit

The effects of Li2O-MgO-B2O3 （LMB） glass additive on the sintering characteristics, phase purity, microstructure, and microwave dielectric properties of Li2MgTi3O8 ceramics were investigated. The experimental results demonstrate that the addition of LMB glass effectively lowers the sintering temperature of Li2MgTi3O8 ceramic from 1025 ℃ to 875 ℃ and induces no obvious degradation of the microwave dielectric properties. Typically, the 1.5%LMB glass-added Li2MgTi3O8 ceramic sintered at 875 ℃ for 4 h shows excellent microwave dielectric properties of Q×f=45403 GHz, εr=25.9 and τf≈0 ℃-1. The dielectric ceramic exhibits stability against the reaction with the Ag electrode, which indicates that the ceramics could be applied in multilayer microwave devices requiring low firing temperatures.

基于观测器的船用调距桨控制系统故障分析与仿真试验

针对船用调距桨控制系统传感器恒偏差、恒增益及液压缸完全失效三种典型故障模式,建立了相应的故障模型,并提出了相容多性能指标约束下的故障诊断观测器算法。进而对MCP34-C/4调距桨螺距控制系统进行了典型故障下的仿真实验和传统观测器诊断方法的对比研究。仿真表明,所提出的故障观测器诊断方法具有快速性、鲁棒性和灵敏性特点,适用于线性模型下船用调距桨控制系统的故障诊断。

浅析外加剂对混凝土的影响成因

在我国建筑行业不断发展的今天,我国的建筑工程在数量上以及质量上都有了非常大的提升和改进。在我国建筑工程施工建设的过程中,混凝土的用量以及质量直接影响着建筑工程的建筑质量以及使用质量,因此在进行混凝土施工的过程中,我们要对混凝土的施工质量给予格外的重视。作为建筑工程中使用量最大,同时也是用途施工最广的施工材料,混凝土施工材料是建筑工程施工中的一种常用施工材料。我们为了有效地提升混凝土的施工质量以及施工性能,我们要在混凝土的施工过程中添加相应的添加剂来改善混凝土的施工性能。本文主要针对外加剂对于混凝土的影响成因进行详细的阐述以及分析,希望通过本文的阐述以及分析能够有效地提升我国混凝土的施工质量,更加有效合理的提升外加剂的添加比例,同时也为我国的建筑工程施工质量的不断提升贡献力量。

新型骨圆针材料的研制与应用

骨圆针是骨科常用的内固定材料,近几年应用范围进一步扩大.但目前临床所应用的国产骨圆针存在易弯曲和成角现象,我们借鉴国外的先进经验研制了YG-1型骨圆针材料,经力学测试和临床应用其性能达到国外产品标准,现总结如下.

The application study of polycarboxylates water-reducing admixture in passenger dedicated line engineering

Polycarboxylate water-reducing admixture possesses the capability which could meet with the comprehensive performance of high performance concrete used in passenger dedicated line engineering.The problems of polycarboxylates water-reducing admixtures existed in the engineering application of were analyzed.At present the key for polycarboxylates application was to settle the compatibility between the water-reducing admixture and the cement and to keep the quality retention of this admixture.

Comparison of nickle release and cytocompatibility between porous and dense NiTi alloy

The porous NiTi(pNiTi)samples were produced by sintering evaporation using Ti−50.8Ni(at.%)gasatomized powders.The samples were analyzed by metallographic microscope and X-ray dispersive spectroscopy(XRD).A comparison of nickel(Ni)release and cytocompatibility between pNiTi and dense NiTi(dNiTi)was made.The results showed that the pNiTi has good mechanical properties.Ni releases from pNiTi in vitro and in vivo are more serious than those form dNiTi.The proliferation and differentiation of cells cultured with the pNiTi extracting liquid are significantly worse,and the rate of early apoptosis is higher.In conclusion,pNiTi is mechanically similar to bone,but pNiTi releases more Ni and interferes with cell proliferation and differentiation.A significantly cautious approach should be adopted when using it as a medical implant.

In vitro biodegradability and biocompatibility of porous Mg-Zn scaffolds coated with nano hydroxyapatite via pulse electrodeposition

The biodegradability and biocompatibility of porous Mg-2Zn（mass fraction, %） scaffolds coated with nano hydroxyapatite（HAP） were investigated. The nano HAP coating on Mg-2Zn scaffolds was prepared by the pulse electrodeposition method. The as-deposited scaffolds were then post-treated with alkaline solution to improve the biodegradation behavior and biocompatibility for implant applications. The microstructure and composition of scaffold and nano HAP coating, as well as their degradation and cytotoxicity behavior in simulated body fluid（SBF） were investigated. The post-treated coating is composed of needle-like HAP with the diameter less than 100 nm developed almost perpendicularly to the substrate, which exhibits a similar composition to natural bone. It is found that the products of immersion in SBF are identified to be HAP,（Ca,Mg）3（PO4）2 and Mg（OH）2. The bioactivity, biocompatibility and cell viabilities for the as-coated and post-treated scaffold extracts are higher than those for the uncoated scaffold. MG63 cells are found to adhere and proliferate on the surface of the as-coated and post-treated scaffolds, making it a promising choice for medical application. The results show that the pulse electrodeposition of nano HAP coating and alkaline treatment is a useful approach to improve the biodegradability and bioactivity of porous Mg-Zn scaffolds.

Enhancing Structural Stability and Pervaporation Performance of Composite Membranes by Coating Gelatin onto Hydrophilically Modified Support Layer

The interfacial compatibility of composite membrane is an important factor to its structural stability, andseparation performance. In this study, poly （ether sulfone） （PES） support layer was first hydrophilically modified with poly（vinyl alcohol） （PVA） via surface segregation during the phase inversion process. Gelatin （GE） was then cast on the PVA-modified PES support layer as the active layer followed by crosslinking to fabricate composite membranes for ethanol dehydration. The enrichment of PVA on the surface of support layer improved interfacial compatibility of the as-prepared GE/PVA-PES composite membrane. The water contact angle measurement and X-ray photoelectron spectroscopy （XPS） data confirmed the surface segregation of PVA with a surface coverage density of -80%. T-peel test showed that the maxima/force to separate the support layer and the active layer was enhanced by 3 times compared with the GE/PES membrane. The effects of PVA content in the support layer, crosslinking of GE active layer and operating parameters on the pervaporative dehydration performance were investigated. The operational stability of the composite membrane was tested by immersing the membrane in ethanol aqueous solution for a period of time. Stable pervaporation performance for dehydration of 90% ethanol solution was obtained for GE/PVA-PES membrane with a separation factor of -60 and a permeation flux of -1910 g.m^-2.h1 without peeling over 28 days immersion.