以Ba云母为主晶相的可切削玻璃陶瓷

基于Ｂａ０．５Ｍｇ３（Ｓｉ３ＡｌＯ１０）Ｆ２－Ｍｇ２Ａ１４Ｓｉ５Ｏ１８－Ｃａ３（ＰＯ４）２系统，制备出了以含Ｂａ碱士云母为主晶相的可切削玻璃陶瓷，弯曲强度σｂ＝２２９ＭＰａ，断裂韧性Ｋｌｃ＝２．４８ＭＰ·ｍ１／２；钻孔速度大于７ｍｍ／ｍｉｎ．优良性能的获得借助于Ｂａ云母玻璃陶瓷可控的显微组织，即相互交错的云母体和“卷心菜”的组织特征．观察到了两类类型的断口形貌：云母晶体层内断的层状花样和沿（００１）晶面层间断的小刻面花样．     

复合材料成形工艺用吸胶材料应用研究

对上海无纺布厂生产的４０ｇ／ｍ＾２及７０ｇ／ｍ＾２热压法涤纶无纺布和杭州新华造纸厂生产的９０ｇ／ｍ＾２、１２０ｇ／ｍ＾２及１７０ｇ。ｍ＾２滤纸与美国Ａｉｒｔｅｃｈ公司的牌号为Ａｉｒｗｅａｖｅ ＦＲ吸胶材料进行了性能对比研究，证明国产５种吸胶材料全部能满足复合材料成形工艺的要求，而且，其中上海无纺布厂生产的两种材料性能优于美国材料。因此，上海无纺布厂生产的４０ｇ／ｍ＾２及７０ｇ／ｍ＾２热压法涤纶无纺     

纳米级LiMn2O4尖晶石合成及电化学性能研究

以Ｌｉ２ＣＯ３和Ｍｎ（ＮＯ３）２为原料,以聚丙烯酰胺为高分子网络剂制得前驱体后,用微波加热技术敢纳米晶尖晶石ＬｉＭｎ２Ｏ４粉体后,通过循环伏安及充放电技术对其进行电化学性能测试表明,该材料的电化学比容量为１２０ｍＡｈ／ｇ,循环５０次后衰减率为４．７％;通过ＳＥＭ及ＸＲＤ分析蓁同观形貌表明,材料不仅相纯度高,粒度返于纳米级,有利于Ｌｉ＾＋的嵌入／脱嵌,本文所的微波－高分子网络技术不仅惧有优良性能的锂     

PS／粉末SBR—g—S共混体研究：Ⅱ.粉末SBR—g—S的相结构 …

测定了ＳＢＲ－ｇ－Ｓ的接枝率,用ＴＥＭ检测了粉末ＳＢＲ－ｇ－Ｓ（ＰＲ）的相结构。用ＤＳＣ测定了ＰＳ／ＰＲ共混体的Ｔｇ,研究了ＰＳ／ＰＲ共混体的相容性。结果发现,在接枝率为３２．６％的粉末非交联ＳＢＲ－ｇ－Ｓ（ＰＲ１）的相结构中ＳＢＲ为连续相,在连续相中均匀分布着直径约０．０１μ的ＰＳ微区;ＰＳ为细胞状分散相,粒径１～５μｍ,分散相含有ＳＢＲ包藏物。在接枝率为８．５％的粉末交联ＳＢＲ－ｇ－Ｓ（ＰＲ２     

普通螺纹测量的模量近似算法

普通螺纹测量的模量近似算法苏宗康（湖北工程机械厂枣阳市４４１２００）１螺纹精密测量的模量原理阿基米德螺纹跨线测量的精确公式是：令：ｄ２ｍ＝ｄ２／Ｐ，２Ｒｍ＝２Ｒ／Ｐ，２Ｆｍ＝２Ｆ／Ｐ，Ｍｍ＝Ｍ／Ｐ，将上述无量纲的模量代入式（１），有：显然，式（２）和...     

Ti系高效催化剂乙烯—1—相烯气相共聚反应及共聚物结构…

研究了Ｔｉ－Ｍｇ催化剂（ＭＧ型）的乙烯－１－丁烯气相共聚合。常压下聚合动力学曲线为衰减型。催化效率为１０．２－１１．０ｋｇ ＰＥ／ｇＴｉ，产物密度ｄ＝０．９０５－０．９２２ｇ／ｃｍ＾３。Φ－１００流化床共聚合（１．２ＰＭａ）催化效率为１３７－１７３ｋｇＰＥ／ｇＴｉ。产物特性粘度「η」ＭＩ２．１６、ＭＦＲ１０．０／２．１６分别为１．０９－２．２２、１．０－６．９、７．８－１０．４。共聚物熔点、结晶度     

镁合金微等离子体氧化膜的特性

采用ｘ射线衍射（ＸＲＤ）、扫描电镜（ＳＥＭ）等方法初步研究了镁合金微等离子体氧化膜的相组成及形貌特征。结果表明，该技术能在镁合金表面生长一层厚度大于１００μｍ并与基体结合良好的氧化膜，提高了合金的耐蚀性。在ＮａＡｌＯ２溶液中对ＭＢ１５镁合金微等离子体氧化时，氧化膜由ＭｇＯ和ＭｇＡｌ２Ｏ４相组成。铝元素已扩散到膜内层，但膜表层存在铝元素富集区。     

二价离子替代的Nasicon及其应用研究

含二价阳离子的Ｎａｓｉｃｏｎ，Ｍ￣（２＋）Ｎａｓｉｃｏｎ（Ｍ＝Ｍｇ、Ｃａ、Ｓｒ、Ｚｎ）可由母体Ｎａ＿３Ｚｒ＿２Ｓｉ＿２ＰＯ＿（１２）（Ｎａｓｉｃｏｎ）为起始原料与相应的二价离子的盐浓液或熔盐进行离子交换而制得。Ｘ射线衍射分析结果表明离子交换后的产物Ｍ￣（２＋）－Ｎａｓｉｃｏｎ大多保持原母体的Ｃ＿（２／ｃ）结构。交流阻抗技术测定的电导率数据显示含不同的二价替代离子的Ｎａｓｉｃｏｎ的电导率相差甚大。其中最好的是Ｍｇ￣（２＋）－Ｎａｓｉｃｏｎ，其电导率在４００℃时可达到１．４８×１０￣（－２）Ｓ／ｃｍ。Ｍｇ￣（２＋）－Ｎａｓｉｃｏｎ用作微功率固态电池Ｍｇ／ＣｕＣｌ的电解质，该电池的开路电压为２．０７Ｖ，短路电流为１ｍＡ。平均放电电压为１．６Ｖ，电池的放电容量是３．４ｍＡＨ。     

结构陶瓷的高温疲劳强度衰减理论

提出了陶瓷材料疲劳强度衰减理论并由此导出了各种疲劳关系式。建立了疲劳基本方程ｄσ＿ｒ／ｄ＿ｉ＝一Ａσ（ｔ）￣ｎｔ￣（－ｍ），得出了疲劳寿命公式Ｔ＝Ｍ（σ＿０－σ）／Ａσ￣ｎ（静疲劳时Ｍ＝１，连续增载疲劳时Ｍ＝ｎ＋１，循环疲劳时Ｍ＝（ｎ＋１）／（１＋Ｒ＋Ｒ￣２＋……＋Ｒ￣ｎ），逐级加载时，并导出不同疲劳方式下疲劳寿命间的关系。同时，用多种Ｓｉ＿３Ｎ＿４材料在高温中作了论证试验，结果与理论一致。     

NH3-MBE生长极化场二维电子气材料

介绍了用ＮＨ３－ＭＢＥ技术在蓝宝石Ｃ面上外延的高质量的ＧａＮ单层膜以及ＧＮ／ＡｌＮ／ＧａＮ极化感应二维电子气材料。外延膜都是Ｎ面材料。形成的二维电子气是“倒置二维电子气”。ＧａＮ单层膜的室温电子迁移率为３００ｃｍ＾２／Ｖｓ。二维电子气材料的迁移率为６８０ｃｍ＾２／Ｖｓ（ＲＴ）和１７００ｃｍ＾２／Ｖｓ（７７Ｋ）,相应的二维电子气的面密度为３．２＊１０＾１３ｃｍ＾－２（ＲＴ）和２．６ｘ１０＾１３ｃｍ＾     

炭纤维织物复合材料微结构超声成像方法

超声波在炭纤维织物复合材料中树脂囊界面声压反射系数可达 21 %,在层间界面的反射则与树脂层的厚度和声波频率有关,在缺陷界面则会产生绝对反射。研究了入射声波在织物复合材料内部树脂囊、编织纤维束和层间界面产生的声波反射信息,揭示织物复合材料内部铺层和层间界面微结构的三维分布特征。结果表明,采用高分辨率超声成像方法,可以较好地再现织物复合材料中的树脂囊和纤维束形状、取向、铺层方向及层间界面等三维分布特征,为织物复合材料提供一种有效的微结构表征和缺陷检测方法。      

Finite Element Computation of Woven Ply Laminated Composite Structures up to Rupture

For unidirectional ply laminates, the great diversity of the damage mechanisms and their patterns of evolution make it extremely difficult to estimate the strength margins. In the case of woven ply laminates, the number of damage mechanisms is fairly small (no transverse rupture occurs and the material has a greater resistance to delamination) and the behaviour of the material is fairly simple to model up to rupture. In this study, a numerical model for woven ply laminated composite structures up to rupture is developed. The implementation is performed in a Euler Backward scheme and the consistent tangent stiffness matrix is calculated. Comparison with some experiments on structures are made and the model predicts these experiments well.     

A generalized damage model for woven ply laminates under static and fatigue loading conditions

A generalized non-linear cumulative damage model for woven ply laminates subjected to static and fatigue loading is developed in this paper. The damage, consisting of small cracks running parallel to the fibers, leads to a loss of stiffness in the warp, weft and shear directions. The model presented here describes the evolution of the damage up to failure of the first ply. By replacing the woven ply by two stacked unidirectional plies corresponding to the warp and weft thicknesses, this general model is extended to cover a broad range of plies, from quasi-unidirectional to balanced woven plies. A continuum damage approach (CDM) is then used to define the behaviour of the two virtual unidirectional plies under static and fatigue loading conditions. The model is applied here to an unbalanced woven ply with glass reinforcement and the results of the simulations are compared with experimental data.     

Experimental investigation of three-dimensional woven composites

This paper summarizes an extensive experimental study of composites reinforced with three-dimensional woven preforms subjected to tensile, compressive and in-plane shear loading. Three innovative three-dimensional woven architectures were examined that utilize large 12 K and 24 K IM7 carbon tows, including two ply to ply angle interlock architectures and one orthogonal architecture. Additionally, a two-dimensional quasi-isotropic woven material was evaluated for comparison. Loads were applied in both the warp and the weft directions for tensile and compressive loading. Digital image correlation was used to investigate full field strains leading up to quasi-static failure. Experimental results including ultimate strengths and moduli are analyzed alongside representative failure modes. The orthogonal woven material was found to have both greater strength and modulus in tension and compression, though a ply to ply woven architecture was found to outperform the remaining three-dimensional architectures. Recommendations are made for improving the manufacturing processes of certain three-dimensional woven architectures.     

Oxidation of As(III) in aqueous solutions by means of macroporous redox copolymers with N-chlorosulfonamide pendant groups

The possibility of oxidizing As(III) to As(V) in aqueous solutions by means of heterogeneous oxidants, i.e. synthetic macromolecular redox compounds, was studied. The materials contain N-chlorosulfonamide functional groups in the sodium form: [P]-SO(2)NClNa (R/ClNa, 2.1 mmol/g) or in the hydrogen form: [P]-SO(2)NClH (R/ClH, 2.4 mmol/g), attached to a cross-linked macroporous poly(styrene-divinylbenzene) matrix. They were obtained through the transformation of Amberlyst 15 (Rohm and Haas) commercial cation exchanger's sulfonic functional groups. The experiments were conducted in the H(2)O and 0.01 M NaOH environment (R/ClNa) and in the H(2)O and 0.01 M H(2)SO(4) environment (R/ClH), using the batch process and the column process and NaAsO(2) solutions (93-375 mg As(III)/dm(3)). The experiments showed that the two copolymers' capacity to oxidize As(III) is high and depends on the process conditions. In the column process experiments, conducted using NaAsO(2) solutions with a concentration of ～ 93 mg As(III)/dm(3) at a flow rate of 4 BV/h (R/ClH) and 6 BV/h (R/ClNa), a breakthrough (defined as the exceedance of 0.05 mg As(III)/dm(3) in the effluent) would occur after the solutions amounting to about 400 bed volumes had been passed through the column.     

铺层混杂对复合材料层压板侵彻性能的影响

本文利用MTS和冲击侵彻测试装置，研究了由芳香族聚酰胺纤维、高强聚乙烯醇纤维制成的织物通过不同铺层方式与酚醛/PVB树脂复合的层压板的准静态和冲击侵彻性能。结果表明，芳香族聚酰胺织物层的加入能显著提高高强维纶织物树脂复合材料层压板的准静态侵彻刚度。随着芳纶混杂体积分数的提高，铺层混杂复合材料层压板的准静态侵彻阻力、穿孔能量（或单位面密度穿孔能量）将随之增加。从防护装具性能/重量比和性能/价格比的角度考虑，在芳香族聚酰胺与高强聚乙烯醇织物铺层混杂复合材料层压板中，高强聚乙烯醇纤维混杂体积分数可以确定为20%左右。     

A non-local criterion for modelling unbalanced woven ply laminates with stress concentrations

A non-local ply scale criterion [Hochard C, Lahellec N, Bordreuil C. A ply scale non-local fibre rupture criterion for CFRP woven ply laminated structures. Compos Struct 2007;80:321–26] was previously developed for predicting the failure of balanced woven ply structures with stress concentrations. This non-local criterion was based on the mean values determined over a Fracture Characteristic Volume (FCV) corresponding to a cylinder with a circular area and the same thickness as the ply. This non-local approach along with a ply scale continuum damage behavioural model was implemented in the ABAQUS Finite Element Code. The behavioural model was developed from a classical Continuum Damage Mechanics (CDM) model [Ladevèze P. A damage computational method for composite structures. Comput Struct 1992;44:79–87]. In the present study, this approach was extended to the case of unbalanced woven ply. The FCV approach and the CDM behavioural model are presented and comparisons are made between the experimental data and the modelling predictions obtained on plates with open holes, notches and saw cuts.     

Synthesis of porous cross-linked polymer monoliths using 1,1,1,2-tetrafluoroethane (R134a) as the porogen

In this paper, we describe the synthesis of porous, cross-linked polymethacrylate monoliths by free radical polymerization using 1,1,1,2-tetrafluoroethane (R134a) as the porogenic solvent. Solvent separations were simple (boiling point R134a=−26.5 °C) and the reactions were carried out at relatively low pressures (<20 bar). It was found that the surface area and the median pore diameter of the materials could be varied over a wide range (5–320 m²/g and 15 nm–5 μm, respectively) by varying the monomer concentration. By contrast, pressure had little influence on the structure of the materials due to the relatively incompressible nature of liquid R134a.     

Higher order models on the eigenfrequency analysis and optimal design of laminated composite structures

This paper deals with the structural optimization of multilaminated composite plate structures of arbitrary geometry and lay up, using single layer higher order shear deformation theory discrete models. The structural and sensitivity analysis formulation is developed for a family of C⁰ Lagrangian elements. The design sensitivities of free vibration response for objective and/or constraint functions with respect to ply angles and ply thickness are presented. The objectives of the design are the maximization of natural frequencies of specified modes and/or the minimization of the structure weight or volume. The accuracy and relative performance of the proposed discrete models are compared and discussed among developed elements and alternative models. Several test designs are optimized to show the applicability of the proposed refined discrete models.     

Interlaminar and intralaminar reinforcement of composite laminates with aligned carbon nanotubes

Three-dimensional reinforcement of woven advanced polymer–matrix composites using aligned carbon nanotubes (CNTs) is explored experimentally and theoretically. Radially-aligned CNTs grown in situ on the surface of fibers in a woven cloth provide significant three-dimensional reinforcement, as measured by Mode I interlaminar fracture testing and tension-bearing experiments. Aligned CNTs bridge the ply interfaces giving enhancement in both initiation and steady-state toughness, improving the already tough system by 76% in steady state (more than 1.5 kJ/m² increase). CNT pull-out on the crack faces is the observed toughening mechanism, and an analytical model is correlated to the experimental fracture data. In the plane of the laminate, aligned CNTs enhance the tension-bearing response with increases of: 19% in bearing stiffness, 9% in critical strength, and 5% in ultimate strength accompanied by a clear change in failure mode from shear-out failure (matrix dominated) without CNTs to tensile fracture (fiber dominated) with CNTs.