Enhanced KR-Fundamental Measure Functional for Inhomogeneous Binary and Ternary Hard Sphere Mixtures

An enhanced KR-fundamental measure functional (FMF) is elaborated andemployed to investigate binary and ternary hard sphere fluids near a planarhard wall or confined within two planar hard walls separated by certaininterval. The present enhanced KR-FMF incorporates respectively, for aim ofcomparison, a recent 3rd-order expansion equation of state (EOS) and aBoublik's extension of Kolafa's EOS for HS mixtures. It is indicated that the two versions of the EOS lead to, in the framework of the enhanced KR-FMF, similar density profiles, but the 3rd-order EOS is more consistent with an exact scaled particle theory (SPT) relation than the BK EOS. Extensive comparison between the enhanced KR-FMF-3rd-order EOS predictionsand corresponding density profiles produced in different periods indicatesthe excellent performance of the present enhanced KR-FMF-3rd-order EOS incomparison with other available density functional approximations (DFAs).There are two anomalous situations from whose density profiles all DFAsstudied deviate significantly; however, subsequent new computer simulationresults for state conditions similar to the two anomalous situations are invery excellent agreement with the present enhanced KR-FMF-3rd-order EOS. The present paper indicates that (i) the validity of the ``naive' substitutionelaborated in the present paper and peculiar to the original KR-FMF is stillin operation even if inhomogeneous mixtures are being dealt with; (ii) thehigh accuracy and self-consistency of the third order EOS seem to allow forapplication of the KR-FMF-third order EOS to more severe state conditions;and (iii) the ``naive' substitution enables very easy the combination of theoriginal KR-FMF with future's more accurate but potentially more complicatedEOS of hard sphere mixtures.     

纳米锡/硬碳复合材料作为嵌锂负极的研究

利用金属铁和钴纳米颗粒的催化活化作用,制备了多孔硬碳球.应用聚焦离子束切割技术,观察到扩孔后的硬碳球中充满彼此连通的发达中孔.在此多孔硬碳球中填入纳米锡(Sn)颗粒,对复合材料的电化学性能进行了测试.     

Characterization of gold]PMMA hybrid nanomaterials synthesized by hard X-ray synchrotron radiation

In this study, new types of hybrid gold poly（methyl methacrylate） （PMMA） nanomaterials are synthesized. Both PMMA spheres coated with gold nanoparticles and gold nanoparticles coated with PMMA can be synthesized using different ratios of HAuCl4 and MMA precursors, by exposing the mixtures to hard X-ray synchrotron radiation without the use of a reducing agent. According to the photochemical mechanism, gold nanoparticles will precipitate from a solution of HAuCl4 on exposure to synchrotron radiation, followed by the synthesis of PMMA by the polymerization of MMA monomers. These reactions can result in the formation of two different types of new hybrid nanomaterials. When a 1：1 volume ratio of HAuCI4 to MMA is used, we obtain PMMA spheres coated with gold nanoparticles. When a 10：1 ratio of HAuCl4 and MMA is used, we obtain gold nanoparticles coated with PMMA. The hybrid gold/PMMA nanostructures are characterized by transmission electron microscopy, elemental analysis, dynamic-light scattering analysis, gel permeation chromatography and Raman spectroscopy. The hybrid nanomaterials have potential application in the fields of biosensors and drug delivery.     

淬硬45钢在高温、高应变率下的动态力学性能及本构关系

在20℃~800℃的温度范围和10-3~104s-1的应变率范围内,采用电子万能试验机和分离式霍 普金森压杆,对淬硬45钢(45HRC)分别进行准静态实验和动态压缩力学性能实验,得到应力应变曲线。结 果表明:淬硬45钢的流动应力对应变率敏感性一般,但表现出较强的温度敏感性,随着应变率的增大而增大, 随着温度的升高而降低。采用以高斯函数表示温度效应的改进Johnson-Cook本构方程拟合了淬硬45钢在 高应变率和高温条件下的本构关系,拟合曲线与实验数据吻合较好。     

激光车床

日本福冈工业大学的专家研制成一种使用紫外激光的激光车床,该车床能够把直径约1000μm的聚酰亚胺硬树脂加工成微型叶轮和轴承等零件．还可加工陶瓷和钻石等坚硬材料。     

聚氨酯/环氧树脂互穿网络聚合物的性能研究

互穿聚合物网络（Interpenetrating polymer net-work,简称IPN）广泛应用的为聚氨酯基的互穿网络聚合物。其合成多集中在弹性体方面。本文用同步法合成的聚氨酯／环氧树脂互穿网络硬质泡沫塑料材料（简称PU／ERIPNF）,机械性能较好,并研究了其动态力学性能及形态变化。     

微波等离子体化学气相沉积法制备C_3N_4薄膜的研究

本文采用微波等离子体化学气相沉积法(MPCVD),高纯N2(99.999%)和CH4(99.9%)作反应气体,在多晶Pt(99.99%)基片上沉积C3N4薄膜。X-射线能谱(EDX)分析结果表明N/C原子比为1.0～1.4,接近C3N4的化学比;X射线衍射谱说明薄膜主要由β和α-C3N4组成;FT-IR谱和Raman谱支持C-N键的存在。     

如何连接家里的数字音响

<正> 笔者主持电台的音响节目,曾发表过一些有关MD的文章,有不少读者来信问:该如何将数字音源与MD连在一起,让MD可以录制数字音源?用什么方式连接家里的数字音响设备才可得到最佳效果?因此,本文介绍数字音响常用的民用数字接口。 常见的数字音源有CD、MD、LD、DVD、DV、DAT、DCC等播放机。并不是所有的数字音源都同时兼具输入接口和输出接口,有些只具备输入接口或者输出接口。其实个人电脑也算是     

聚氨酯硬链段球晶生长与软硬链锻混容性的关系

线型可溶性聚氨酯的硬链段结晶难以长成球晶 ,然而本实验室已经证明即使从熔体结晶硬链段也是能够长成球晶的 .研究了聚酯与聚醚型聚氨酯硬链段长球晶的规律 ,并发现聚氨酯硬链段长球晶的难易与聚氨酯软硬链段混容性密切相关 .动态力学分析 (DMA)与示差扫描量热 (DSC)实验表明聚ε 已内酯 (PCL)、聚已二酸丁二醇酯 (PTMA)、聚四氢呋喃 (PTMO)及聚环氧丙烷 (PPO)型聚氨酯的软硬链段混容性从前至后递减 .从熔体退火结晶时 ,聚氨酯硬链段长成球晶的退火温度范围是有限的 ,软硬链段混容性越好 ,聚氨酯硬链段能长成球晶的温度范围越窄 ,所需长的时间越长 .聚氨酯硬链段长球晶的下限温度取决于软硬链段间所存在的氢键作用 ,聚氨酯硬链段长球晶的上限温度与软硬链段混容性直接相关 .     

上海深部硬土渗透特性试验研究

上海深部硬土层的沉降显著滞后于水位变化, 本文通过一系列渗透试验进行了相关问题的研究, 包括初始水力坡度, 结核对渗透性的影响, 压力对渗透性的作用, 以及孔隙比与渗透系数之间规律的研究。结果表明硬土的渗透速率与水力坡度之间符合良好的线性关系, 满足达西定律; 大量的致密结核对渗透性影响微弱; 应力增加导致渗透性降低, 渗透系数与孔隙比呈指数规律变化。基于试验成果评价了1989～2007年天然硬土的渗透性变化, 此期间硬土层边界水位下降了近30m, 硬土层的沉降造成了该层渗透性的降低, 但土层的平均渗透系数改变不大。