Dynamical scaling of the structure factor of some non-Euclidean systems

Predictions of nonlinear theories on dynamics of new phase formation have been examined for the hydration of calcium silicates with light water and heavy water. In the case of hydration with light water, reasonable agreement has been observed with dynamical scaling hypothesis with a new measure of the characteristic length. The characteristic length does not follow a power law relation with time. Hydrating mass is found to be mass fractal throughout hydration, with mass fractal dimension increasing with time. But, in the case of hydration with heavy water, no agreement has been observed with the scaling hypothesis. Hydrating mass undergoes transition from mass fractal to surface fractal and finally again to mass fractal. The qualitative features of the kinetics of hydration, as measured in small-angle scattering experiments, are strikingly different for hydration with light water and heavy water.     

精确的量子化条件和不变量

提出并证明了一维量子系统和三维球对称量子系统的一个精确的量子化条件.在此精确量子化条件中, 除了通常的Nπ项外, 还有一积分项, 称为修正项. 发现该修正项正是在超对称量子力学中所谓的有形状不变势的量子系统的一个不变量，它不依赖于波函数的节点数.对这些系统, 可用基态能级和波函数确定此不变量的值, 从而由精确的量子化条件容易算出全部束缚态的能级. 计算得到能级的正确性又反过来验证了在有形状不变势的量子系统中此修正项确实是不变量.计算的有形状不变势的量子系统, 包括一维的有限方势阱、Morse势及其变形、R 关键词： 量子化条件 超对称量子力学 形状不变势 不变量     

KOPLS-DA在掺杂牛奶判别中的应用

运用核隐变量正交投影(kernel orthogonal projection to latent structure, KOPLS)方法,建立掺杂牛奶与纯牛奶的判别模型。分别配置含有三聚氰胺牛奶(0.01～3 g·L-1)和尿素牛奶(1～20 g·L-1)样品各40个,采集纯牛奶及掺杂牛奶样品的近红外光谱。选择4 200～4 800 cm-1为建模区间,采用KOPLS分别建立掺杂三聚氰胺、掺杂尿素、两种掺杂牛奶与纯牛奶的判别模型,并利用这些模型对未知样品进行判别。研究结果表明：与偏最小二乘判别(partial least squares discriminant analysis, PLS-DA)和隐变量正交投影判别(orthogonal projections to latent structures discriminant analysis, OPLS-DA)建模方法相比,KOPLS-DA具有更强的掺杂判别能力,对掺杂三聚氰胺、掺杂尿素牛奶和两种掺杂牛奶的判别正确率分别为95%,100%和97.5%。     

Rosochatius Deformed Soliton Hierarchy with Self-Consistent Sources

Integrable Rosochatius deformations of finite-dimensional integrable systems are generalized to the soliton hierarchy with self-consistent sources. The integrable Rosochatius deformations of the Kaup-Newell hierarchy with self-consistent sources, of the TD hierarchy with self-consistent sources, and of the Jaulent-Miodek hierarchy with self-consistent sources, together with their Lax representations are presented.     

采用铜铝复合管的翅片管换热器性能试验研究

针对铜铝复合管(ACC管)在空调用翅片管换热器中替代铜管应用进行了试验研究。分别对Ф7.94mm型管的全铜管、过冷段铜铝复合管、全铜铝复合管三种换热器进行了性能比较和成本分析。研究结果表明,在风速和风量不变的情况下,过冷段铜铝复合管换热器能力为8634.22W,高于全铜铝复合管的换热器的8389.36W,低于全铜管换热器的8989.07W。制冷剂侧能力测试中,过冷段铜铝复合管换热器平均值为8.885kW,与全铜铝复合管换热器平均值8.775kW相比高1.24%,与全铜管换热器平均值9.101kW相比低2.37%,与能力测试结果基本一致。与原换热器铜管相比,在相同条件下,铜铝复合管可以降低管材成本29.5%。综上所述,过冷段采用铜铝复合管的换热器能够取代铜管换热器应用在空调中,在不影响其换热性能的基础上,降低成本效果明显。     

表面电荷密度法的应用研究

本文介绍了一种边界积分方程法——表面电荷密度法。它可用于处理轴对称电场和三维电场,特别是包含介质和开放边界的系统;还可用来精确确定各种形状电极间的电容。本文对应用此法所遇到的各种奇异性问题进行了讨论,在理论推导的基础上,编制了通用程序,它可处理包含圆形、直线形电极和介质的轴对称系统,可处理矩形平面电极的三维场。利用这个程序,对尖端发射体外的电位分布及快速变像管中一种常用的聚焦系统的空间电位分布进行了计算,与差分法作了比较,还计算了考虑介质边界后的影响;计算了单球体的空间电位分布,并与解析值进行了比较,计算了几种模型的电容,并与解析值和极限值进行了比较。     

多辊轧机冷轧技术在靶材料制备中的应用

 叙述了多辊轧机轧制金属薄膜原理,以Ti膜制备为例,借助多辊轧机冷轧技术进行1.5 μm厚钛薄带的制备工艺研究。对薄膜的特性测试结果表明：工作辊的表面粗糙度对于轧制薄膜的表面粗糙度的影响很大,降低工作辊表面的粗糙度可以得到粗糙度为25.2 nm的金属薄膜。     

Off-axial contribution of beam self-focusing in plasma with density ripple

Off-axial contribution of beam self-focusing in plasma with density ripple is investigated. Apply paraxial ray theory and Wentzel–Krammers–Brillouin approximation, the results shown that, in interaction of laser and plasma with density ripple, beam self-focusing presents some interesting diverse features when off-axial contribution is obvious. In the paper, we find, on the one hand, density ripple can minimize the defocusing and beam still retains a localized profile with an oscillatory self-focusing and defocusing, on the other hand, with the increase of off-axial contribution, laser beams presents four various self-focusing features, which laser beam intensity profile splits into three-splitted with central axial convex profile, three-splitted with equal amplitude profile, three-splitted with central axial concave profile and two-splitted intensity profile.     

Optical properties of the surface transition-metal structures in fluoride ionic crystals and peculiarities of their formation during thermal diffusion

The possibility of forming surface films with an elevated concentration of an impurity metal during high-temperature diffusion has been analyzed for a wide series of ionic crystals: LiF with Co, Ni, Mg, Ca, Ba, and Sr impurities; NaF with Co, Mn, Mg, Ca, and Sr; MgF₂ with Co and Ni; and CaF₂ with Co. It is established that films are formed only on alkali halide crystals with impurities of transition metals and are not formed on alkaline earth fluorides with transition metals, as well as on alkali halide crystals activated with other divalent cationic impurities. The dynamics of the increase and decrease in the intensity of centers related to impurity-vacancy dipoles during thermal diffusion is shown. The mechanisms of film formation are explained in terms of the features of growth and structure of ionic crystals with cationic impurities and on the basis of isomorphism rules.     

Magnetic resonance of the inferior vena cava.

MRI was performed in 54 patients with abnormalities of the inferior vena cava (IVC). These included 16 patients with extrinsic IVC compression, 32 patients with intrinsic IVC abnormalities, and 6 patients with IVC dilatation. All patients had spin-echo imaging, and 21 had MR angiography. While presaturated spin-echo images showed intrinsic lesions to advantage, collateral vessels were best appreciated with MR angiography. The IVC is well evaluated with MRI techniques.     

The structure of vocal sounds produced with the mouth closed or with the mouth open in treefrogs

Frogs and toads mostly call with their mouths shut, unlike many other vertebrates. Sound is generated when air crosses the larynx, but there is no direct airflow to the external environment and radiation occurs at the skin. This study directly compares the acoustic output obtained from euthanized frogs with the mouth open against the output obtained with the mouth closed during activation of the larynx by airflow. With the mouth closed, the vocal sac was inflated and the acoustic energy was concentrated in the same harmonics as in the advertisement call, whereas with the mouth open, energy was spread in a wide range of harmonics. The acoustic output at the dominant frequency was more intense with the mouth closed than with the mouth open. More sound was radiated through the vocal sac and head than through the rest of the body. The spectral differences between open and closed mouth treatments matched the differences observed between natural advertisement calls, produced with the mouth closed, and distress calls, produced with the mouth open. By calling with the mouth closed, treefrogs can potentially produce advertisement calls with the energy concentrated in a narrower frequency range than with the mouth open.     

Evolution of star clusters with a mass distribution of binaries

Summary The dynamical evolution of star clusters with a initial population of binaries strongly depends on the parameters of the bounded pairs. We performed computational simulation with directN-body codes, on models withN=300 objects, with initial fraction of 20% of binaries with the same orbital semi-axis and with a Salpeter mass spectrum. The results are compared with previous analysis on similar equal-mass star models. The calculation points out that binaries with different mass companions determine an enhanced and sudden expansion of the system with neither core collapse nor central mass segregation. Paper presented at the 2° Convegno Nazionale di Fisica Cosmica, held at L'Aquila, 29 May – 2 June 1984.     

基于SSPCM的新型储能型太阳能蒸馏器实验研究

本文基于定型相变材料(SSPCM)建立了新型储能型太阳能蒸馏器的实验系统,并分别对普通SSPCM和高导热SSPCM的蒸馏特性进行了实验研究.研究发现:与传统太阳能蒸馏器相比,基于普通SSPCM的储能型蒸馏器的日产量提升了 7.5％,采用高导热SSPCM的日产量提升了 39％.此外,本文还对蒸馏器结构进行了优化研究,研制...     

NMR imaging of solids with magic angle spinning.

Different aspects of solid state NMR imaging are reviewed, with emphasis on imaging in combination with line narrowing, especially in combination with magic angle spinning. Experimental results obtained with the latter technique are discussed, along with the implications of magic angle spinning on slice selection.     

The Acoustic Performance of 3D Printed Multiple Jet Nozzles with Different Configurations

This work investigated multiple jet nozzles with various geometrical shape, number of exits, and material on reducing noise radiated from jet flows. Nozzles are categorized in two groups with few and many exit numbers, each with various exit shapes, slot and circular, and geometry. Firstly, nozzles are designed and then fabricated by a 3D printer, Form Labs, Form2USA, with polymeric resin. Also, the nozzle with the most noise reduction made of stainless steel. Noise and air thrust were measured at three air pressure gauges, 3, 5, 7 BAR and directions from nozzle apex, 30°, 90°, 135°. Nozzles with slot exit shape made of both plastic and stainless steel revealed the most noise reduction among all nozzles with few exit numbers, nearly 11–14 dB(A) and 11.5–15 dB(A), respectively. On average, slotted nozzle noise reduction was nearly 5–6 dB(A) more than finned nozzle. However, nozzles with more exit numbers, finned and finned-central exit, illustrated much more noise reduction than nozzles with few exit numbers, by almost 16–18 dB(A), they represented similar sound. All tested nozzles and open pipe demonstrated equal air thrust at each pressure gauges. The nozzles with slotted exit shape, either plastic or stainless steel, can provide reasonable noise reduction in comparison to other configuration with few exit numbers. In contrast, nozzles with more exit numbers demonstrated the most noise reduction.     

星载高分辨率超光谱成像仪分光方式的选择

从多个方面分析了棱镜和光栅色散分光的优缺点,分析结果表明棱镜更适于星载高分辨率超光谱成像仪的分光。在透过率方面,棱镜光谱仪透过率高达95.24％(VNIR),而光栅的衍射效率仅为60%~70%。在杂散光方面,棱镜光谱仪的杂散光可达10－4,而光栅的杂散光为10－2。在0.4 －2.5 范围,棱镜光谱仪相对光栅光谱仪有优越性。在色散线性方面,光栅光谱仪基本线性,棱镜光谱仪的短波非线性问题可通过复合棱镜进行补偿。可靠性方面,棱镜光谱仪较光栅光谱仪有优势;在光谱带宽和成本方面,棱镜光谱仪与光栅光谱仪基本接近。     

Surface-coated fly ash reinforced biodegradable poly(vinyl alcohol) composite films: part 2-analysis and characterization

Composite films of poly(vinyl alcohol) (PVA) reinforced with 5, 10, 15, 20 and 25 wt.% surface-coated fly ash by surfactant, sodium lauryl sulphate (SLS-FA) along with 1 wt.% cross-linking agent, glutaraldehyde (GLA) were prepared by aqueous casting method. The tensile strengths of the composite films were increased proportionally with the addition of SLS-FA. The maximum 75% higher strength of the composite with 20 wt.% was achieved compared to that of neat PVA. The modulus of the composites was also increased proportionally with SLS-FA and the maximum 218% reached in composite with 20 wt.%, but the strain at break was decreased with addition of SLS-FA. Changes in FTIR spectra reflect the chemical and/or physical bonding in the ternary PVA, SLS-FA and GLA component systems. In the study of surface morphology, the connectivity was visualized in SEM images along with interstitial voids. The films with SLS-FA show 53% smoother surface calculated with AFM compared to unmodified FA composite films.     

聚酰亚胺/铜纳米颗粒复合物的分子动力学模拟研究

通过分子动力学模拟对聚酰亚胺/铜纳米颗粒复合物的形态结构、 热力学性质、力学特性进行计算, 分析其随模拟温度和纳米颗粒尺寸的变化规律. 模拟结果表明, 聚酰亚胺/铜纳米颗粒复合物为各向同性的无定形态结构, 铜纳米颗粒与聚酰亚胺基体之间通过较强的范德华作用结合在一起使结构更加稳定, 铜纳米颗粒表面多个原子层呈现无定形状态, 在铜颗粒和聚酰亚胺基体之间形成界面层, 界面区域随颗粒尺寸和温度的增加分别减小和增加. 聚酰亚胺/铜纳米颗粒复合物的等容热容随着颗粒尺寸增大而明显增高, 随温度变化比聚酰亚胺体系更为缓慢, 在较低温度下较小颗粒尺寸复合物的热容比聚酰亚胺体系更低. 聚酰亚胺/铜纳米颗粒复合物的热压力系数随颗粒尺寸增加而显著增大, 比聚酰亚胺体系的热压力系数更小, 且随温度升高而减小的程度要小得多. 聚酰亚胺/铜纳米颗粒复合物的热力学性质表现出明显的尺度效应, 温度稳定性明显高于聚酰亚胺体系. 聚酰亚胺/铜纳米颗粒复合物的力学特性表现出各向同性材料的弹性常数张量, 具有比聚酰亚胺体系更低的杨氏模量和泊松比, 随温度升高分别减小和增大, 与聚酰亚胺体系随温度的变化趋势相反, 且杨氏模量的温度稳定性显著提高, 同时泊松比随纳米颗粒尺寸增大而减小, 具有明显的尺度效应. 加入铜纳米颗粒形成复合物可获得与聚酰亚胺体系显著不同的力学新特性. 关键词： 分子动力学模拟 聚合物纳米复合物 聚酰亚胺 纳米颗粒     

Studies on modified power law inflation

In this study, we evaluate power law inflation (PLI) with a monomial potential and obtain a novel exact solution. It is well known that the conventional PLI with an exponential potential is inconsistent with the Planck data. Unlike the standard PLI, the present model does not encounter the graceful exit problem, and the results agree fairly well with recent observations. In our analysis, we calculate the spectral index and the tensor-to-scalar ratio, both of which agree very well with recent observational data and are comparable with those of other modified inflationary models. The employed technique reveals that the large cosmological constant decreases with the expansion of the universe in the case of the PLI. The coupling of the inflaton with gravitation is the primary factor in this technique. The basic assumption here is that the two metric tensors in the gravitational and inflaton parts correspond to different conformal frames, which contradicts with the conventional PLI, where the inflaton is directly coupled with the background metric tensor. This fact has direct applications to different dark energy models and the assisted quintessence theory.     

1-氨甲基-6,7-二甲氧基-1,2,3,4-四氢异喹啉盐酸盐的合成及表征

以3,4-二甲氧基苯乙胺为原料,经氯乙酰氯酰化得到N-氯乙酰基-3,4-二甲氧基苯乙胺,通过与邻苯二甲酰亚胺钾烃化,在P2O5的作用下经Bischler-Napieralski环合后,用水合肼肼解,硼氢化钾还原后与盐酸作用得1-氨甲基-6,7-二甲氧基-1,2,3,4-四氢异喹啉盐酸盐。产品结构经IR、1H NMR、MS确证。