自保护硼氮共渗膏剂的研究

为研究自配制的自保护硼氮共渗膏剂的性能，对Q235钢、45钢、T8钢和GCrl5钢等试样进行共渗试验。实验表明，45钢以选用890C共渗为宜；钢中的碳阻碍硼的渗入；涂层厚度以4mm为宜；膏剂硼氮共渗试样的耐磨性与固体硼氮复合渗相当，而比固体渗硼试样则好得多；经膏剂硼氮共渗的试样耐100％HCl和30％H2SO4的腐蚀性与固体硼氮复合渗处理过的试样相当，二者均比1Crl8Ni9Ti钢要好；Q235钢高温缓冷后易出现Fe3N相。表明该膏剂共渗性能与固体硼氮相当，而优于固体渗硼。     

低温下纤维增强复合材料阻尼的若干影响因素

研究了纤维种类、升降温方向、加载频率、加载波形、湿度、应力等若干因素对复合材料低温下阻尼性质的影响 .着重考察了这些因素对阻尼峰的影响 ,并对出现的现象给出了解释 ,所得到的结果为应用和进一步的研究工作提供了基础数据 .     

Synthesis and Properties of Photo-functional Hyperbranched Polymers

1 Results UV curing systems have been widely used in various industries such as coatings,printing inks,and photo-resists,because of their low volatile organic compound (VOC),excellent physical properties,and energy saving.Recently,these systems have also been applied to electronics and information technology fields such as display,CD,DVD,optical-fiber,and optical-device. In these curing systems,(meth)acrylate oligomers are mainly used due to their high photochemical reactivity. Recently,dendritic polyme...     

超高压力下通电烧结制备钼铜合金

采用超高压力下通电烧结技术制备了铜体积分数25%～75%的钼铜合金材料. 烧结压力2～10 Gpa,通电功率15 kW,通电时间65 s. 分析了不同成分和制备工艺参数的钼铜合金显微形貌及力学性能. 结果表明,所制备的钼铜合金材料结构致密,力学性能优越,而且超高压力下通电烧结技术能有效地避免晶粒长大和组织偏析.     

非晶CoZrNb磁性薄膜的研究

研究溅射条件和旋转磁场热处理对CoZrNb薄膜结构和性能的影响。结果表明,高的溅射功率和合适的氩气压强对非晶CoZrNb薄膜的形成有用,并且这些薄膜的矫顽力较小。旋转磁场热处理将改善薄膜的软磁性能,使得矫顽力进一步减小。对溅射条件对薄膜性能的影响机制和旋转磁场热处理改善薄膜性能的机制作了简要的讨论。     

Chiral inorganic nanostructures for theranostics

Inorganic chiral nanomaterials have attracted wide attention because of their superior physical properties and chiroptical activities. Great progress in chiral nanostructure preparation has been made, such as noble metals and semiconductors. In this review, we introduce several chiral nanomaterials with feasible biocompatibility and low cytotoxicity that are promising candidates for biological applications, and we focus on their preparation in terms of their circular dichroism (CD) effects and circular luminescence properties. Additionally, we summarize the working function of chiral nanostructures toward some common diseases with high prevalence, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), diabetes and even cancers. The introduction of inorganic chirality will provide a novel way to diagnose and treat these diseases.     

塞拉利昂粘土制造建筑陶瓷的可行性评价

研究了塞拉利昂不同沉积地区的3种粘土的物理、化学和矿物性质，以确定这些粘土是否可用于生产建筑陶瓷。结果表明，Mambolo粘土具有中等可塑性，Nitti和PaLoko粘土具有高可塑性，符合陶瓷制品的原料要求，XRD图谱和SEM照片表明：石英和高岭石是这些粘土的主要矿物成分，它们经1250℃烧成后形成大量的莫来石和少量的α-方石英，表明[ 些粘土适合用于生产建筑陶瓷，但由于Fe2O3含量偏高，故不可直接用于生产白色陶瓷，而需作进一步处理，不过可直接用于生产非白色陶瓷制品，如陶瓷墙地砖等。     

Preparation of 3D graphene-based architectures and their applications in supercapacitors

Three dimensional (3D) graphene-based architectures such as 3D graphene-based hydrogels, aerogels, foams, and sponges have attracted huge attention owing to the combination of the structural interconnectivities and the outstanding properties of graphene which offer these interesting structures with low density, high porosity, large surface area, stable mechanical properties, fast mass and electron transport. They have been extensively studied for a wide range of applications including capacitors, batteries, sensors, catalyst, etc. There are several reviews focusing on the 3D graphene-based architectures and their applications. In this work, we only summarise the latest development on the preparation of 3D graphene-based architectures and their applications in supercapacitors, with emphasis on the preparation strategies.     

Sn-Ag-Sb+M系无铅焊料的基本性能研究

传统的Sn-Pb钎料及Pb基软钎料除有毒外，还存在力学性能方面的问题．因此必须寻找新的性能优良的钎料，对Sn-Ag-Sb M合金系进行了研究，对所选定的合金系进行力学性能。物理性能及界面性能等方面的实验测试．通过对实验数据的综合、处理和分析优化出一种综合性能颇优的合金成分。     

Self-organization of supramolecular helical dendrimers into complex electronic materials

The discovery of electrically conducting organic crystals and polymers has widened the range of potential optoelectronic materials, provided these exhibit sufficiently high charge carrier mobilities and are easy to make and process. Organic single crystals have high charge carrier mobilities but are usually impractical, whereas polymers have good processability but low mobilities. Liquid crystals exhibit mobilities approaching those of single crystals and are suitable for applications, but demanding fabrication and processing methods limit their use. Here we show that the self-assembly of fluorinated tapered dendrons can drive the formation of supramolecular liquid crystals with promising optoelectronic properties from a wide range of organic materials. We find that attaching conducting organic donor or acceptor groups to the apex of the dendrons leads to supramolecular nanometre-scale columns that contain in their cores pi-stacks of donors, acceptors or donor-acceptor complexes exhibiting high charge carrier mobilities. When we use functionalized dendrons and amorphous polymers carrying compatible side groups, these co-assemble so that the polymer is incorporated in the centre of the columns through donor-acceptor interactions and exhibits enhanced charge carrier mobilities. We anticipate that this simple and versatile strategy for producing conductive pi-stacks of aromatic groups, surrounded by helical dendrons, will lead to a new class of supramolecular materials suitable for electronic and optoelectronic applications.     

多相Mo-Si-B合金材料的性质

多相Mo-Si-B合金是非常具有吸引力的新型高温结构材料. 它熔点高、抗氧化性、抗蠕变性和室温断裂韧性好.阐述了Mo-Si-B微观结构对多相Mo-Si-B合金性能的影响,举例说明了多相Mo-Si-B合金的抗氧化性及断裂韧性比钼或钼的硅化物有明显提高.指出了存在的问题和今后努力方向.     

Ductile Fe-based amorphous alloys with high iron content

Fe-based amorphous alloys with high iron content of 76at%–80at% were synthesized in the Fe-Mo-Si-P-C-B alloy system by the single roller melt-spinning technique. The amorphous ribbons exhibit high Vickers microhardness and good ductility, which can be indented and bent 180° without breaking. A number of shear bands could be observed around the indents and the bending traces. Studies on the magnetic properties of the amorphous alloys show that they possess high saturation magnetizations of 1.34–1.6 T, which increases with the increase of iron content. The core losses of these Fe-based amorphous alloys at various magnetic inductions were tested and found to be significantly dependent on their components. The Fe-Mo-Si-P-C-B amorphous alloys with excellent mechanical properties and soft magnetic properties have promising potential in functional applications.     

碳纤维增强水泥复合材料的研究进展

碳纤维增强水泥复合材料是一种集结构和功能于一体的新型材料,与普通水泥比较,它高强、导电,对温度和应力敏感,具有电磁屏蔽等特征,介绍了碳纤维增强水泥复合材料的制备方法、性能、应用及其最新研究进展,着重展望了其在功能材料方面的研究应用前景。     

Neuronal-type Na+ and K+ channels in rabbit cultured Schwann cells

Nerve axons in the central and peripheral nervous system are normally surrounded by satellite cells. These cells, known as Schwann cells in the peripheral nervous system, interact with axons to form a myelin sheath, so allowing nerve impulses to proceed at high speed. Schwann cells are thought to differ from neurones in their membrane properties in one important aspect: they lack excitability. Using the patch-clamp technique we have now measured directly the ionic currents across the membrane of single Schwann cells cultured from newborn rabbits. Surprisingly, we found that these Schwann cells possess voltage-gated sodium and potassium channels that are similar to those present in neuronal membranes.     

Role of visual pigment properties in rod and cone phototransduction

Retinal rods and cones share a phototransduction pathway involving cyclic GMP. Cones are typically 100 times less photosensitive than rods and their response kinetics are several times faster, but the underlying mechanisms remain largely unknown. Almost all proteins involved in phototransduction have distinct rod and cone variants. Differences in properties between rod and cone pigments have been described, such as a 10-fold shorter lifetime of the meta-II state (active conformation) of cone pigment and its higher rate of spontaneous isomerization, but their contributions to the functional differences between rods and cones remain speculative. We have addressed this question by expressing human or salamander red cone pigment in Xenopus rods, and human rod pigment in Xenopus cones. Here we show that rod and cone pigments when present in the same cell produce light responses with identical amplification and kinetics, thereby ruling out any difference in their signalling properties. However, red cone pigment isomerizes spontaneously 10,000 times more frequently than rod pigment. This high spontaneous activity adapts the native cones even in darkness, making them less sensitive and kinetically faster than rods. Nevertheless, additional factors are probably involved in these differences.     

稀土元素Gd、Ho和Dy在磁共振成像应用的研究进展

Gd、Ho和Dy因其独特的光学和磁学性质而在生物成像等方面有着广泛的应用.在镧系元素中,Gd~(3+)具有7个不成对的电子,可以提供高的弛豫度,已被广泛地用于磁共振成像(MRI)造影剂,而Ho~(3+)和Dy~(3+)具有最短的电子弛豫时间和最高的有效磁矩,因此有良好的高场T_2弛豫效果.介绍了基于这3种稀土元素的纳米材料在MRI方面的应用.     

一类高维随机矩阵置乱变换的周期

为了适合多媒体信息量庞大、存在数据冗余的特点,实施可证明安全、高效率的加密解密,使用了数论、近世代数、矩阵变换、算法分析等工具,对高维随机矩阵置乱变换的精确周期进行了研究。将实数域上线性代数的若干结果,推广到模素数有限域上,得到一类整数矩阵及其相关同余方程组之解的若干新性质;在此基础上将用于置乱的矩阵由2维扩展到任意高维,给出广泛一类高维随机整数矩阵A决定的置乱变换,在任意素数幂N=pr模数下,其周期T(A,N)的精确表达式,给出求精确周期算法的时间复杂度。结论可用于建立新型数字多媒体密码体制和信息隐藏体制,扩大其密钥空间,增加其安全性。     

Colloidal nanocrystal synthesis and the organic-inorganic interface

Colloidal nanocrystals are solution-grown, nanometre-sized, inorganic particles that are stabilized by a layer of surfactants attached to their surface. The inorganic cores possess useful properties that are controlled by their composition, size and shape, and the surfactant coating ensures that these structures are easy to fabricate and process further into more complex structures. This combination of features makes colloidal nanocrystals attractive and promising building blocks for advanced materials and devices. Chemists are achieving ever more exquisite control over the composition, size, shape, crystal structure and surface properties of nanocrystals, thus setting the stage for fully exploiting the potential of these remarkable materials.     

求解双曲守恒律方程的高次有限元方法

将Galerkin高次有限元应用于双曲守恒律的Hamilton Jacobi方程 ,得到了求解双曲守恒律的一类数值格式。这类格式在CFL条件下具有TVD性质 ,在更强的条件下 ,其半离散格式的数值解收敛于守恒律方程的熵解。数值结果表明 ,这类格式具有较高的分辨激波的能力。     

高强钢薄壁管梁结构轴向冲击性能的数值分析

以点焊连接闭口帽形结构为例,选择3种典型高强钢材料,比较了不同板厚结构的轴向冲击特性.分析了冲压成形过程造成的帽形结构局部几何和材料属性变化,对该过程进行了数值仿真,将成形结果映射至碰撞仿真模型中,比较了成形因素对不同模型的影响,并与理论解析解进行了比较.研究结果表明:冲压成形过程导致结构局部减薄和材料加工硬化,对双相钢的影响最为明显;引入成形因素改变了轴向冲击变形的屈曲方式和后继变形模式,在先进高强钢材料的碰撞仿真中不可忽视;平均冲击力数值仿真结果与理论解析解存在一定偏差,但均表明双相钢具有更优良的变形吸能特性.