柚子皮制备多孔碳材料处理聚氯乙烯微塑料废水实验研究

柚子皮是福建漳州常见的农业废弃物,作为垃圾处理对环境造成一定压力,急需开展资源化利用。本论文以柚子皮为原料,碱活化和高温碳化制备多孔碳材料,并将其应用于聚氯乙烯微塑料的处理。实验结果表明,制备的多孔碳材料对聚氯乙烯微塑料具有较好的吸附处理效果。聚氯乙烯微塑料去除率随着吸附时间和多孔碳材料投加量的增加而逐渐增大。多孔柚子皮碳材料适宜在弱酸或弱碱性条件下处理聚氯乙烯微塑料废水。这为柚子皮资源化利用提供了新方向和技术。     

碳化秸秆处理污水中氮磷元素的研究

多孔物质由于具有较大的比表面积,有较强的吸附作用,目前常被利用来吸附氮磷元素。以碳化秸秆为材料,研究了在不同条件下利用多孔物质来处理富营养化水体中氮磷元素的效果。     

Vapor-phase fabrication and properties of continuous-filament ceramic composites

The continuous-filament ceramic composite is becoming recognized as necessary for new, high-temperature structural applications. Yet because of the susceptibility of the filaments to damage from traditional methods for the preparation of ceramics, vapor-phase infiltration has become the fabrication method of choice. The chemical vapor infiltration methods for producing these composites are now being studied in earnest, with the complexity of filament weaves and deposition chemistry being merged with standard heat and mass-transport relationships. Two of the most influential effects on the mechanical properties of these materials are the adhesion and frictional force between the fibers and the matrix, which can be controlled by a tailored interface coating. A variety of materials are available for producing these composites including carbide, nitride, boride, and oxide filaments and matrices. Silicon carbide-based materials are by far the most advanced and are already being used in aerospace applications.     

Polymer replicas of photonic porous silicon for sensing and drug delivery applications

Elaborate one-dimensional photonic crystals are constructed from a variety of organic and biopolymers, which can be dissolved or melted, by templating the solution-cast or injection-molded materials in porous silicon or porous silicon dioxide multilayer (rugate dielectric mirror) structures. After the removal of the template by chemical dissolution, the polymer castings replicate the photonic features and the nanostructure of the master. We demonstrate that these castings can be used as vapor sensors, as deformable and tunable optical filters, and as self-reporting, bioresorbable materials.     

Materials with negative compressibilities in one or more dimensions

Rare crystal phases that expand in one or more dimensions when hydrostatically compressed are identified and shown to have negative Poisson's ratios. Some of these crystals (i) decrease volume and expand in two dimensions when stretched in a particular direction and (ii) increase surface area when hydrostatically compressed. Possible mechanisms for achieving such negative linear and area compressibilities are described for single crystals and composites, and sensor applications are proposed. Materials with these properties may be used to fabricate porous solids that either expand in all directions when hydrostatically compressed with a penetrating fluid or behave as if they are incompressible.     

Porous semiconducting gels and aerogels from chalcogenide clusters

Inorganic porous materials are being developed for use as molecular sieves, ion exchangers, and catalysts, but most are oxides. We show that various sulfide and selenide clusters, when bound to metal ions, yield gels having porous frameworks. These gels are transformed to aerogels after supercritical drying with carbon dioxide. The aerogels have high internal surface area (up to 327 square meters per gram) and broad pore size distribution, depending on the precursors used. The pores of these sulfide and selenide materials preferentially absorb heavy metals. These materials have narrow energy gaps (between 0.2 and 2.0 electron volts) and low densities, and they may be useful in optoelectronics, as photocatalysts, or in the removal of heavy metals from water.     

Composites in armor

Composite materials are traditionally regarded as materials that can save energy in large structures associated with transport. They are used to produce lightweight structures for fuel-efficient aircraft such as the new Boeing 787 Dreamliner; lightweight cars from Lotus, Ferrari and TVR; and high-speed trains, speedboats, and racing yachts. Now, however, some of the most interesting applications of composites are those where the materials are used to save lives and protect property by absorbing the energy of projectiles, impacts, and crashes.     

3种木塑复合材料的耐老化性能比较

木塑复合材料的老化性能直接关系其使用寿命和适用范围。使用稻壳、橡胶木锯末和橡胶籽壳分别与回收聚乙烯混合制备木塑复合材料。通过色差分析、红外光谱分析和差示扫描量热法(DSC),研究了3种木塑复合材料经紫外荧光老化后表面颜色、化学成分及结晶度的变化。结果表明,经2 000 h紫外荧光辐照后,处理B(锯末)ΔL和ΔE值为35和30,处理A(稻壳)为40和37,处理C(橡胶籽壳)为45和43;3种材料表面羰基浓度增大,表面氧化程度加深;紫外荧光辐照1 000 h后,处理B(锯末)结晶度由59.21上升到88.44,增加了49.37%;处理A(稻壳)结晶度由63.53上升到94.00,增加了47.96%;处理C(橡胶籽壳)结晶度由55.42上升到98.35,增加了77.46%。     

Ceramic thin-film formation on functionalized interfaces through biomimetic processing

Processing routes have been developed for the production of thin ceramic films through precipitation from aqueous solutions. The techniques are based on crystal nucleation and growth onto functionalized interfaces. Surface functionalization routes have been developed by the mimicking of schemes used by organisms to produce complex ceramic composites such as teeth, bones, and shells. High-quality, dense polycrystalline films of oxides, hydroxides, and sulfides have now been prepared from "biomimetic" synthesis techniques. Ceramic films can be synthesized on plastics and other materials at temperatures below 100 degrees C. As a low-temperature process in which water rather than organic solvents is used, this synthesis is environmentally benign. Nanocrystalline ceramics can be produced, sometimes with preferred crystallite orientation. The direct deposition of high-resolution patterned films has also been demonstrated. The process is well suited to the production of organic-inorganic composites.     

Bioinspired design and assembly of platelet reinforced polymer films

Although strong and stiff human-made composites have long been developed, the microstructure of today's most advanced composites has yet to achieve the order and sophisticated hierarchy of hybrid materials built up by living organisms in nature. Clay-based nanocomposites with layered structure can reach notable stiffness and strength, but these properties are usually not accompanied by the ductility and flaw tolerance found in the structures generated by natural hybrid materials. By using principles found in natural composites, we showed that layered hybrid films combining high tensile strength and ductile behavior can be obtained through the bottom-up colloidal assembly of strong submicrometer-thick ceramic platelets within a ductile polymer matrix.     

木基金属功能复合材料研究进展

为弥补木材固有的缺陷,改变木材物理、力学、化学性质和构造特征,对木材功能改性的研究从未间断过,从最初的木材塑合技术、浸渍技术、乙酰化技术、热处理技术、压缩和弯曲技术、漂白和染色技术等,到现在较为先进的微波处理技术,均极大地推动了木材科学的发展。随着对木材基本物化性能研究的逐步深入,新型木基复合材料也应运而生,如木基金属功能复合材料,其赋予木材新的电磁屏蔽、导热和导电等功能。根据木基金属复合材料的功能特性,可将其分为3类:电磁屏蔽木材、金属化木材和浸透型磁性木材。电磁屏蔽木材主要用于有射线辐射空间的地板、棚板、壁板等,其制备方法主要有化学镀金属和胶合金属两种,化学镀金属是通过化学的方法使木材表面金属化,胶合金属是通过胶黏剂将金属材料与木材相结合,这两种方法均能提高木材的电磁屏蔽效能,可以减少电磁辐射对人体的伤害。金属化木材是将低熔点合金以熔融状态浸透到木材细胞中并冷却固化后形成的复合材料,熔融状态的金属以木材导管为载体,使复合材料的压缩强度、硬度、导热性、导电性、耐磨性、冲击韧性等大幅度提高,可作导热木材用于地热采暖领域。浸透型磁性木材是在一定的压力下使磁流体浸透到木材内,从而制得带有磁性的木材,可用在磁记录、记忆、电磁转换、屏蔽、防护、医疗和生物技术、分离纯化等诸多领域。目前,木基金属功能复合材料的研究主要集中在木材表面化学镀上,此种制备方法金属只能覆盖在木材表面,而不能浸透到木材内部。金属化木材可以使金属浸透到木材中,但现有研究所用的基材没有经过处理,金属的渗透性不高,如何改善基材,最大限度发挥金属化木材的优异性能,进一步推动木基金属功能复合材料的应用范围,将是下一步研究的重点。本文对3种不同功能复合材料（电磁屏蔽木材、金属化木材和浸透型磁性木材）的研究现状进行概述,同时提出木基金属功能复合材料现有研究中的不足,并展望金属化木材在更多领域的应用和发展前景。      

Composites reinforced in three dimensions by using low magnetic fields

The orientation and distribution of reinforcing particles in artificial composites are key to enable effective reinforcement of the material in mechanically loaded directions, but remain poor if compared to the distinctive architectures present in natural structural composites such as teeth, bone, and seashells. We show that micrometer-sized reinforcing particles coated with minimal concentrations of superparamagnetic nanoparticles (0.01 to 1 volume percent) can be controlled by using ultralow magnetic fields (1 to 10 milliteslas) to produce synthetic composites with tuned three-dimensional orientation and distribution of reinforcements. A variety of structures can be achieved with this simple method, leading to composites with tailored local reinforcement, wear resistance, and shape memory effects.     

山羊同种部份移植的实验研究

<正> 骨的保存和移植在国内、外曾有过许多报导和专著。R.B.Olds指出:“同种骨移植在-20℃或-30℃冰冻3—4个月或-76℃至少冰冻21—25天,移植后得到好的效果”。并认为感染的和未感染的移植物,其吸收是相同的。Fred Langer等认为同种移植骨可使动物产生细胞和体液免疫,但可通过低温冰冻来克服,并证明冰冻在-20℃、     

Comparison of comet 81P/Wild 2 dust with interplanetary dust from comets

The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles appear to be absent from the returned sample, indicating that indigenous outer nebula material is probably rare in 81P/Wild 2. Instead, the sample resembles chondritic meteorites from the asteroid belt, composed mostly of inner solar nebula materials. This surprising finding emphasizes the petrogenetic continuum between comets and asteroids and elevates the astrophysical importance of stratospheric chondritic porous interplanetary dust particles as a precious source of the most cosmically primitive astromaterials.     

硅橡胶复合体系的阻燃特性研究

向硅橡胶复合材料中引入阻燃剂,赋予硅橡胶复合材料阻燃特性,探讨了阻燃剂的选择、阻燃作用和对材料介电性能以及力学性能的影响.结果表明,二硫化钼具有优异的阻燃性能,但因对硅橡胶的击穿场强影响较大而无法使用.适当粒度的Al（OH）3在偶联剂存在下,对硅橡胶复合材料具有更好的阻燃作用,而且对材料介电性能影响小.     

Synthesis of zeolite as ordered multicrystal arrays

Zeolites are crystalline nanoporous aluminosilicates widely used in industry. In order for zeolites to find applications as innovative materials, they need to be organized into large two- and three-dimensional (2D and 3D) arrays. We report that uniformly aligned polyurethane films can serve as templates for the synthesis of uniformly aligned 2D and possibly 3D arrays of silicalite-1 crystals, in which the orientations of the crystals are controlled by the nature of the polymers. We propose that the supramolecularly organized organic-inorganic composites that consist of the hydrolyzed organic products and the seed crystals are responsible for this phenomenon.     

木质素三甲基季铵盐为模板剂制备多孔氧化硅材料

为了探索以小质素为模板剂制备无机多孔材料的方法,提高木质素产品附加值,以小质素三甲 铵盐为模板剂、正硅酸乙酯为硅源,采用溶胶凝胶法和焙烧脱模法制备多孔氧化硅材料。结果表明：小质素三甲基事铵盐行在于煅烧前的复合物中,煅烧后得到的多孔氧化硅材料中木质素三甲基季铵盐吸收峰消失,但具有SiO2特征吸收峰;多扎氧化硅材料孔隙发达...     

Applications of microcomputer-based image digitization in soil and crop sciences

A procedure for microcomputer-based digitization of images is proposed using an IBM-PC microcomputer and a TECMAR digitizer board. Using cross sections of impregnated porous materials such as glass beads, sandstones and soils, procedures are described to determine the porosity, pore (chord) size distribution, and permeability of porous materials. The estimation of root length and width is also carried out using image digitization. A final example is the measurement of eroded soil areas from aerial photographs.     

非金属及复合材料在汽车上的应用与发展

对汽车用非金属及复合材料的应用现状进行了综述。指出了目前在开发与应用中存在的问题，讨论了汽车用非金属及复合材料的开发对我国汽车工业发展的重要意义。     

利用废弃物制备生物炭资源化研究与应用进展

生物炭制备的原材料来源广泛,大部分废弃物可以通过炭化手段得到生物炭。生物炭是一种吸附 材料,其结构多孔,官能团种类多样,在污染修复、改良土壤等方面有应用前景。综述各种可以制备生物炭的材料、 归纳常用的生物炭制备方法和生物炭的表征特性,总结生物炭在修复污染环境、改良土壤环境和作为新型化肥 方面的研究应用,以找出当前废弃物制备生物炭的资源化应用重点和方向,并对生物炭在产量化制备、规模化 应用方面进行展望。