二茂铁基长链烷基β-二酮的反相色谱分析

以乙腈－水，甲醇－「乙酸－水（１０％，Ｖ／Ｖ）」为ＲＰ－ＴＬＣ和ＢＰ－ＨＰＬＣ流动相测定了二茂铁锘长链烷基β－二酮同系物的反相色谱行为，同系物的保留值ＲＭ和ｌｏｇｋ＾１与化合物的长链烷基碳原子数及流动相中有机改性剂的体积分数均成线性关第八ｓ＾１和截距ｌｏｇｋｗ值也线性相关。     

酚类化合物苯环碳原子的化学位移与其净电荷的关？…

用ＡＢ－ＩＮＩＴＩＯ法对只含酚羟基的７种酚化合物的苯环碳原子的净电荷做了计算，并测定或查阅了它们的＾１３ＣＮＭＲ谱，参考标准图谱找出了Ｃｉ对应的化学位移δｉ，发现Ｑｉ－δｉ间呈现较好的线性关系。每种化合物均有最负净电荷与最低化学位移（δｍｉｎ），Ｑｍｉｎ与δｍｉｎ出现在酚羟在邻位同一碳原子上，而这一碳原子具有最大的亲核－亲电反应活性。那些δｉ〉１３０的碳原子反应活性极小，以至不能发生亲核－亲电反应     

酚类化合物苯环碳原子的化学位移与其净电荷的关系（ …

用从头算ＲＨＦ／６－３１Ｇ方法对卤代酚苯环碳原子的电荷分布进行量子化学计算,从标准图谱上查阅了这些化合物苯环碳原子的化学位移,氟能使其邻、对位负电荷明显增加,化学位移减小,氯,溴的效应不明显,碘呈现出相反的作用,苯环各碳原子Ｃｉ的化学位移δｉ与其净电荷Ｑｉ值基本呈线性关系,较大的卤素取代基本身起大的电荷屏蔽作用,使邻近碳原子化学位移受到影响,化学位移有助于判断卤代酚类化合物的反应活性,可推测氟代酚     

SiC长纤维增强玻璃陶瓷基复合材料的研究

采用涨浆浸渍热压工艺制备ＫＤ－１ＳｉＣ长纤维增强玻璃陶瓷其复合材料。研究烧结温度和纤维体积分数对复合材料力学的影响。ＳｉＣｆ／ＢＡＳ复合材料的抗弯强度和断裂韧性最大达到４９４．１ＭＰａ和１８．２８ＭＰａ．ｍ＾１／２,ＳｉＣｆ／ＭＡＳ复合材料的抗弯强度和断裂韧性最大达到５３８．７ＭＰａ和１６．７０ＭＰａ．ｍ＾１／２。结合试样的断口形貌和抗载荷－位移曲线分析了复合材料的失效方式。     

关于亚纯函数的唯一性定理

本文结合导数、亏量对仪洪勋发表于中国科学（Ａ辑，１９９４．５，Ｐ．４５７－４６６）的一个结果进行研究，得到了定理：“设Ｓ１＝｛１，ω，…，ω＾ＴＲ－｝，Ｓ２＝｛∞｝，其中ω＝ｃｘｐ（２π／ｍ，ｆ和ｇ是非常数亚纯函数。如果ｍ≥４且δ（０，ｆ）＋δ（∞，ｆ）〉２，Ｅｆ（π）（Ｓｉ）＝Ｅｇ（π）（Ｓｉ）（ｉ＝１，２），其中ｎ是非负整数，那么ｆ＾ｎ≡ｇ＾ｎ或［ｆ＾（ｎ）ｇ＾（ｎ）＾１Ｒ］≡１。”例子表明此     

判断取代基相对诱导效应强度的新方法——Ⅰ取代基中与甲基碳原子相连原子不具有不饱和键的情况

以CH4为母体,甲烷1个氢原子被取代基R取代生成的CH3R为模型,计算CH3R中甲基碳原子化学位移与甲烷碳原子化学位移的差值Δδ以及CH3R中甲基碳原子净电荷值与甲烷碳原子净电荷的差值ΔQ,将其作为判断基团相对氢原子诱导效应强度的新方法.研究结果表明,当取代基中与甲基碳原子相连原子不具有不饱和键时,2种计算结果具有紧密的相关性.就本文所列基团而言,由这2种新方法得到的相对诱导效应强弱与已有的化学规律甚为吻合.     

C^n中单位球上函数空间及其对偶

设φ和φ是Ｃ＾ｎ中单位球Ｂ上分别满足当／ｚ／→１时φ（ｚ）→为和∫Ｂψｄｖ〈∞的正连续函数。令Ａ０（φ）和Ａ∞（φ）分别表示由Ｂ上满足条件当／ｚ／→１时,／ｆ（ｚ／φ（ｚ）→０和／ｆ（ｚ）／φ（ｚ）〈Ｃ（Ｃ为正常数）的解析函数全体按范数∥ｆ∥＝ｓｕｐ／ｆ（ｚ）φ（ｚ）／所成的Ｂａｎａｃｈ空间,Ａ＾１（ψ）表示Ｂ上解析函数全体按范数∥ｆ∥＝∫Ｂ／ｆ／ψｄｖ〈∞所成的空间。该文指出如果权函数φ,ψ为一     

高阶Schrodinger方程的一类半隐式差分格式

构造高阶Ｓｃｈｒｏｄｉｎｇｅｒ方程ｉδｕ／δｔ＋（－１）＾ｍδ＾２ｍｕ／δｘ＾２ｍ＝０的一类半隐式差分格式，给出了它们的稳定性条件。     

亚纯函数涉及亏函数的相对亏量

该文研究了整函数和亚纯函数涉及亏函数的相对亏量，将Ｓｉｎｇｈ关于亚纯函数相对亏量的结果推广到亏函数的情况，主要得到了下面的一些关系式：（１）Ｈｒ＾（ｋ）（Ａ（Ｚ），ｆ）≤２－｛δ（０，ｆ）＋Ｈ（∞，ｆ）｝Ａ（Ｚ）≠０，∞；（２）δ＾（ｋ）ｒ（∞，ｆ）≤３／２－１／２｛δ（０，ｆ）δ（Ａ（Ｚ），ｆ）｝，Ａ（Ｚ）≠０，∞；（３）如果δ（０，ｆ）＝δ（∞，ｆ）＝１，则Ｈ＾（ｋ）ｒ（Ａ（Ｚ），ｆ）＝０。     

奥氏体晶粒尺寸对45V非调质钢组织和性能的影响

研究了４５Ｖ钢初始状态奥氏体晶粒尺寸对其组织和性能的影响，得出显微组织和力学性能的关系。结果表明，随相变前奥氏体晶粒尺寸增大，铁素体数量减小，硬度与强度提高，塑性降低。４５Ｖ钢先共析铁素体体积分数（ｆα）与硬度（ＨＶ）、缺口试样的强度（σｂＮ）和塑性（ΨＮ）的关系为ＨＶ＝３７０－４２Ｆα１／３，σｂＮ＝１４６６－１１１０ｆα１／３，ΨＮ＝３２＋０．５７ｆα。     

基于电容电感移相单元的MEMS移相器

为减小基本结构开关线型微机电(MEMS)移相器的面积,提出了一种新型的基于电容电感移相单元的小型化3位开关线型MEMS移相器。该移相器用MEMS工艺制成的交叠结构的电容电感移相单元代替原始的延迟传输线,其90°移相单元的长度比传统90°延迟线的缩短近3/4,45°移相单元的长度比原始延迟线的缩短近1/2,有效缩小了移相器的整体面积。用HFSS(high frequency structuresimulator)软件进行了仿真及优化设计。仿真结果表明:在20GHz到40GHz频段内,45°移相单元的回波损耗优于-27.25dB,插入损耗优于-0.33dB;90°移相单元的回波损耗优于-26.25dB,插入损耗优于-0.51dB。在35GHz时,整个3位移相器能够完成0～360°、间隔为45°的移相,平均插入损耗为-2.63dB,回波损耗优于-15dB,平均相位误差为3.67°。根据仿真结果,所设计的MEMS移相器适用于35GHz小型化相控阵雷达。     

Atomic phase diagram

Based on the Thomas-Fermi-Dirac-Cheng model, atomic phase diagram or electron density versus atomic radius diagram describing the interaction properties of atoms of different kinds in equilibrium state is developed. Atomic phase diagram is established based on the two-atoms model. Besides atomic radius, electron density and continuity condition for electron density on interfaces between atoms, the lever law of atomic phase diagram involving other physical parameters is taken into account, such as the binding energy, for the sake of simplicity.     

Colloidal ordering from phase separation in a liquid-crystalline continuous phase

Some binary mixtures exist as a single phase at high temperatures and as two phases at lower temperatures; rapid cooling therefore induces phase separation that proceeds through the initial formation of small particles and subsequent growth and coarsening. In solid and liquid media, this process leads to growing particles with a range of sizes, which eventually separate to form a macroscopically distinct phase. Such behaviour is of particular interest in systems composed of an isotropic fluid and a liquid crystal, where the random distribution of liquid-crystal droplets in an isotropic polymer matrix may give rise to interesting electro-optical properties. Here we report that a binary mixture consisting of an isotropic fluid and a liquid crystal forming the continuous phase does not fully separate into two phases, but self-organizes into highly ordered arrays of monodisperse colloidal droplet chains. We find that the size and spatial organization of the droplets are controlled by the orientational elasticity of the liquid-crystal phase and the defects caused by droplets exceeding a critical size. We expect that our approach to forming monodisperse, spatially ordered droplets in liquid crystals will allow the controlled design of ordered composites that may have useful rheological and optical properties.     

调合石蜡的相平衡参数和相变动力学特性

使用正规溶液模型的Scatchard-Hildebrand方程对调合石蜡的熔点、浊点以及固-液和组元相变速率进行了计算.以切片石蜡作为被调合石蜡的计算结果表明,烷烃的相变温度和切片石蜡相近时,该烷烃对调合石蜡的熔点、浊点以及相变动力学特性影响较小.增加C22类轻质烷烃的质量分数,调合石蜡的熔点、浊点降低;熔程内较低温度下,轻质烷烃相变速率变慢,重质烷烃相变速率变快.增加C35类重质烷烃的质量分数,调合石蜡的浊点升高,熔点呈现复杂的变化,对C24以下烷烃的相变速率几乎没有影响,C25以上烷烃在熔程内较低温度下相变速率变慢.计算结果可以为相变储能中选用具有适当相变温度及相变动力学特性的调合石蜡提供指导.     

投影栅相位法三维检测的频域相对解相技术

为提高投影栅相位法在三维检测实际应用中的解相精度 ,分析了频谱混叠及移频方法的不准确对解相精度造成的影响 ,建立了一种新的频域相对解相技术。基于小波变换得到相对栅线图像 ,其频谱中背景成分基本消除 ,有利于有用频带的提取。同时 ,通过计算两幅图像的相对位相 ,避免了单幅图像移频方法所带来的系统误差。实例证明该技术改善了解相的精度和稳定性 ,提高了投影栅相位法的应用水平     

Coherent quantum phase slip

A hundred years after the discovery of superconductivity, one fundamental prediction of the theory, coherent quantum phase slip (CQPS), has not been observed. CQPS is a phenomenon exactly dual to the Josephson effect; whereas the latter is a coherent transfer of charges between superconducting leads, the former is a coherent transfer of vortices or fluxes across a superconducting wire. In contrast to previously reported observations of incoherent phase slip, CQPS has been only a subject of theoretical study. Its experimental demonstration is made difficult by quasiparticle dissipation due to gapless excitations in nanowires or in vortex cores. This difficulty might be overcome by using certain strongly disordered superconductors near the superconductor-insulator transition. Here we report direct observation of CQPS in a narrow segment of a superconducting loop made of strongly disordered indium oxide; the effect is made manifest through the superposition of quantum states with different numbers of flux quanta. As with the Josephson effect, our observation should lead to new applications in superconducting electronics and quantum metrology.     

Room-temperature electronic phase transitions in the continuous phase diagrams of perovskite manganites

Highly correlated electronic systems--such as transition-metal oxides that are doped Mott insulators--are complex systems which exhibit puzzling phenomena, including high-temperature superconductivity and colossal magnetoresistivity. Recent studies suggest that in such systems collective electronic phenomena are important, arising from long-range Coulomb interactions and magnetic effects. The qualitative behaviour of these systems is strongly dependent on charge filling (the level of doping) and the lattice constant. Here we report a time-efficient and systematic experimental approach for studying the phase diagrams of condensed-matter systems. It involves the continuous mapping of the physical properties of epitaxial thin films of perovskite manganites (a class of doped Mott insulator) as their composition is varied. We discover evidence that suggests the presence of phase boundaries of electronic origin at room temperature.