可控降解抗感染材料的合成和表征

在聚己内酯(PCL)与六亚甲基二异氰酸酯(HDI)缩合体系中加入抗菌药物环丙沙星(CF),制备CF嵌入聚氨酯(PU)主链的聚氨酯前药CFPU。用UV、FTIR、H-NMR表征其结构;GPC法测定分子量;UV法测定载药率;摸索影响其分子量和载药率的主要因素;并用琼脂稀释法测定其胆固醇酯酶(CE)降解液对金黄色葡萄球菌的抗菌活性。结果表明,确已成功制得目标产物;PCL浓度和HDI加料方式分别对其平均分子量和载药率有较大影响;而其CE降解液对金黄色葡萄球菌具有抗菌活性。因此,当其用作医用内植物的涂层材料时,能被炎症组织所分泌的CE可控降解为这种具抗菌活性的降解液,从而可发挥抗感染作用。     

可控降解抗感染材料的体外释药机制研究

在前期合成并表征了可控降解抗感染材料环丙沙星聚氨酯（CFPU）的基础上,建立高效液相色谱法（HPLC）测定其体外降解释放抗菌药物环丙沙星的含量;通过制作累积药物释放曲线,考察不同降解介质及其浓度对药物释放的影响;并对累积药物释放曲线进行拟合,研究其体外可控降解的药物释放机制。结果表明建立的HPLC法简单准确可靠。该材料的降解具有生物响应性,且符合一级动力学;药物释放是以Ritger-Pappas方程（0.45     

Fe-based metallic glass: An efficient and energy-saving electrode material for electrocatalytic degradation of water contaminants

Excessive consumption of electrical energy has hampered the widespread application of electrochemical technology for degradation of various contaminants. In this paper, a Fe-based metallic glass (MG) was demonstrated as a new type of electrocatalyst to effectively and economically degrade an azo dye. In comparison to other typical electrodes, Fe-based MG electrodes exhibit a minimized degradation time, and the specific energy is 4–6 orders of magnitude lower than that of dimensionally stable anode (DSA), metal-like boron-doped diamond (BDD) and other electrodes. As sacrificial electrode materials, Fe-based MGs have less specific electrode mass consumption than iron electrodes. The use of Fe-based MGs will promote the practical application of electrochemical technology and the use of MGs as functional materials.     

炭材料负载金属催化剂在活化过硫酸盐中的应用进展

近年来,基于硫酸根自由基的高级氧化技术在环境污染治理中的应用受到越来越广泛的关注,而炭材料负载金属催化剂在活化过硫酸盐去除环境污染物方面展示出巨大的优势。全面总结了炭材料负载金属离子、金属单质、金属氧化物等而制备的不同催化剂在活化过硫酸盐中的作用机制以及对污染物的降解效果等方面的研究进展,并指出了该类催化剂在活化过硫酸盐氧化中的应用前景与未来的研究方向。     

细菌纤维素负载TiO_2用于DDNP废水光催化降解研究

细菌纤维素(BC)是一种环保可再生的生物材料,其具有很强的机械性能,很好的化学稳定性以及低廉的价格等优点。选用细菌纤维素为载体制备出具有优异形貌的TiO2/BC杂化纤维。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FT-IR),X射线光电子能谱(XPS)等对负载型TiO2的结构及形貌进行表征。最后通过测试杂化纤维对DDNP(二硝基重氮酚)废水的光催化降解效率和重复使用率评价其光催化性能。结果显示了该杂化材料对DDNP废水具有优异的光催化降解性能。     

Enzymatic degradation of native and acetylated starch-based extruded blends

Blends including natural wheat starch and acetylated starch (with substitution degree 1.5) have been extruded so as to obtain a new packaging material. The influence of this extrusion upon the biodegradability of the blends was studied for several acetylated to natural starch ratios both by a colourimetric method (measure of reducing sugars) and by chromatographic analysis (determination of quantities of degradation products). The action of a single α-amylase (Fungamyl 800 from Aspergillus oryzae) only leads to degradation of the unmodified part of the starch. On the other hand, an acetylesterase (Viscozyme from Aspergillus niger) acting in synergy with the same α-amylase leads to significant degradation of the two major components of the extruded blends. For instance, with 10% acetylated starch 100% of the blend is degraded. The major product of degradation is glucose (97%) because Viscozyme also has α-glucosidase activity. So, the present study shows the degradable character of this new packaging material even with a high acetylation value. © 1998 John Wiley & Sons, Ltd.     

Applications of nonlinear ultrasonics to the NDE of material degradation

Nonlinear ultrasonics is suggested as a new approach for the effective evaluation of material degradation. As its quantification, the parameter beta is introduced on the basis of nonlinear elasticity, and a new method to measure the parameter beta using bispectral analysis is proposed. Then, the correlation between beta and material degradation is investigated. From the results for several mild steel (SS41, SS45) specimens that were degraded by stretching and cyclic loads, it was confirmed that the parameter beta has a strong correlation with material degradation. As another practical application, the evaluation of the aging degradation in a high temperature material is tried. For this, Cr-Mo-V specimens that are generally used in turbine rotors in power plants were prepared, and the variation of beta caused by aging time was investigated. For comparison, the fracture appearance transition temperature (FATT) of the specimen was measured, and its behavior showed good agreement with beta. In addition, for all of the experiments, no noticeable change in attenuation and sound velocity in the same specimens with change of degradation were observed. From these results, it may be concluded that nonlinear ultrasonics could be applied to the quantitative evaluation of material degradation.     

Amphiphilic carbonaceous material modified graphite as anode material for lithium-ion batteries

Artificial graphite powder was coated by amphiphilic carbonaceous material (ACM) in aqueous solutions. SEM and XRD results show that the surface defects and edge sites of original graphite are uniformly covered by the ACM coating layer after modification. The overall characteristics of graphite, however, are not severely changed. Electrochemical measurements were then carried out to evaluate the anode performances of samples in lithium-ion batteries. The modified graphite shows an initial efficiency up to 90.6% and discharge capacitance of 366.4 mAhg^− 1. Meanwhile, its capacitance remains as high as 350 mAhg^− 1 after 30 cycles charge/discharge tests, evincing good cyclic performance. Compared with conventional methods, the abovementioned non-organic solvent coating presents an economic, facile, and green pathway for graphite mass utilisation as an alternative anode material in lithium-ion batteries.     

吸波材料研究进展及其对军事隐身技术的影响

隐身技术是通过应用特殊的材料和结构来达到降低可探测性的技术,吸波材料就是其中一种重要的军事隐身功能材料。按材料成型工艺和承载能力,吸波材料可分为涂覆型和结构型两种。其在当今军事上各个领域的应用将对隐身技术的发展产生深远影响,军用吸波材料的未来前途一片光明。     

Determination of the thermal state of material subjected to erosive degradation

The experimental data are generalized and governing parameters and analytic relations for estimating the thermal state of material subjected to the thermoerosive action of a dusty gas flow are proposed. Comparison of the results of numerical calculations obtained using the method described in [1] with estimates based on the relations proposed gives the error of the latter.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 52, No. 2, pp. 209–215, February, 1987.     

Mechanical degradation of foam-cored sandwich materials exposed to high moisture

Sandwich specimens composed of E-glass/polyester face sheets bonded to a PVC foam core were exposed to high moisture (95% RH) and immersed in sea-water for extended periods of time. Degradation of mechanical properties of the face sheets, foam core and face/core interface were progressively evaluated using flexural testing of the laminates, through-thickness tension of the foam core and interfacial sandwich DCB fracture testing. Testing reveals substantial flexural stiffness and strength reductions for the laminated composites, and only minor reduction in the tensile stiffness and strength of the foam. Degradation of the interfacial face/core fracture toughness is weak for specimens subjected to elevated moisture and more pronounced for sandwich specimens immersed in sea-water. After 30 days of exposure to high moisture, foam damage is visible in the form of cracks and pits on the cell walls. Optical examinations of expansional strains show that moisture absorbed by the foam penetrates only about to 2–3 mm from the core free surface for the 95% RH condition, while penetrates deeply for the immersed condition.     

材料的表情

材料是产品构成中的物质要素,而材料的表情是一种审美情感,所以对材料表情的合理使用关系到产品的审美功能的发挥,从3个方面进行讨论:材料与色彩的同构性,材料表情与形态、加工工艺的密切关系,材料表情的应用.从而说明设计师要抓住材料的表情、学会用材料进行思维的重要性,指出研究材料表情的意义.     

Environmental degradation using functionally graded material approach

Attempts to model the degradation of polymer composites have been restricted to modelling the effects of selected degradation mechanisms. No comprehensive model has yet been accepted to predict the effect of the natural environment on the strength of polymer composites. From a review of available literature, it appears that the matrix of a polymer composite is most affected by exposure to the natural environment. Further, the damage appears to progress from the surface into the interior of the laminate. An approach has been developed to determine the properties of the damaged layer and combine the properties of the damaged and undamaged layer to obtain bulk material properties of the laminate.     

云南传统包装材料的探索

我国正提倡西部经济的开发,而包装对云南经济的发展有极大的促进作用.云南的包装要体现出特色离不开对传统包装材料的探索,多样的材料以及合理化的应用,这些都将为现代包装设计提供重要的借鉴.     

Polycarbonate as a photoelastic material

The use of commercial grade polycarbonate for photoelastic models is evaluated and hints given on methods of annealing, machining, stress freezing and preparation of slices for viewing.     

Utilizing three-dimensional fluorescence's red-shift cascade effect to monitor mycobacterium PRY-1 degradation of aged petroleum

Samples of Mycobacterium PRY-1 inoculated motor oil are subjected to three-dimensional fluorescence spectroscopy to document the shifting of excitation/emission maxima as the solutions undergo serial dilutions. Effects such as self-quenching of individual polycyclic aromatic hydrocarbons (PAHs) and energy transfer between PAHs combine to produce large red-shifts in the resulting fluorescence emission spectra. This process is repeated over a series of weeks and is compared to preceding spectra to gauge the microbial degradation of the petroleum. Results show a two-fold, or 75%, PAH contaminant degradation by Mycobacterium PRY-1 over a 140-day growth period.     

辐射降解法制备低聚水溶性壳聚糖之一:辐射降解方法研究

以食品级大分子壳聚糖为原料,在几种不同的状态下,利用辐射降解的方法,对制备低聚壳聚糖的条件进行了研究。结果表明,在溶液状态下,采用较小的辐照剂量,就可以得到分子量＜10000的低聚水溶性壳聚糖。     

一种新型的多功能热致调光材料

提出了一种新型的多功能热致调光材料,其光学透光率在0.6%～92%之间可通过温度进行调节.介绍了其工作原理,报道了光学性能、热稳定性、电学性能,以及在智能窗、温度传感器、热可逆记录等热光学领域的器件和应用.     

制备多孔壳聚糖膜的新方法:选择性酶解原位成孔

利用溶菌酶对中等脱乙酰度壳聚糖的选择性降解,将其与高脱乙酰度壳聚糖以不同比例混合浇铸成膜.考察了降解过程中材料的失重和溶液还原糖含量的变化,用傅立叶红外光谱分析了混合膜的成分改变和降解过程中膜的变化,并用扫描电镜观察了混合膜降解后的形态变化.结果表明,壳聚糖混合膜中的中等脱乙酰度壳聚糖被溶菌酶选择性的降解,而且当混合膜中该组分含量为0.5时,降解后膜表面及内部均产生了互相贯穿的纳米尺寸的孔,剩余的高脱乙酰度成分表现为纳米尺寸的纤维.该方法通过壳聚糖的选择性酶解原位成孔,为制备纳米结构的多孔壳聚糖膜提供了一个新颖的途径.     

纳米镍/炭复合材料的制备与磁性表征

以废弱酸型聚丙烯酸系阳离子交换树脂为炭前驱体,经过与镍离子交换后,再经热解制备纳米镍粒子均匀分散于炭基体的纳米镍/炭(Ni/C)复合材料.以XRD、TEM为主要分析手段研究了热解条件对纳米镍粒子在Ni/C复合材料中的形貌、大小的影响.结果表明:通过热解条件可以控制Ni/C复合材料中纳米镍粒子的平均粒径;热解温度的升高和热解保温时间的增加都可使Ni/C中纳米镍粒径增大.磁性能测试结果表明: Ni/C-500表现为超顺磁特性,而Ni/C-600、Ni/C-700为铁磁性;Ni/C-600、Ni/C-700的比剩磁化强度、矫顽力都要大于微米镍粉与块体镍,但其比饱和磁化强度要小于微米镍粉和块体镍.