为原子核科学研究用的原子核乳膠核-2,核-3,制备方法的研究

本文对于原子核乳胶核—2、核—3制备方法中的几个主要问题进行了初步研究。通过这些研究,我们掌握了制备过程中各种主要因素的关系和它们对于乳胶性能的影响,从而制成了性能良好的原子核乳胶。我们用控制乳化过程中溴离子浓度的方法解决了颗粒大小均匀问题;选择适当的成熟条件和用三乙醇胺增感解决了乳胶对质子的灵敏度问题;用加金盐的方法解决了潜影衰退问题;用纯化明胶的方法解决了雾点问题。     

分子核间距对非时序双电离的影响

利用半经典再散射模型研究了激光强度在一定范围内时分子核间距对非时序双电离过程的影响.分别计算了非时序双电离率、两电子的电离能、两电子的动量相关、Coulomb和激光场的复合势随分子核间距的变化关系.研究表明,分子核间距在1.0—6.0 a.u.范围内时,非时序双电离率和两电子动量和为零的双电离事件数随着分子核间距的增大而增大.当分子核间距继续增大(大于6.0 a.u.)时,非时序双电离率和两电子动量和为零的双电离事件数却减小.     

一个相对论性氧原子核碎裂事例的观测及其机制解释

本文分析了用200GeV/核子氧原子核轰击的乳胶叠,对一个相对论性氧原子核碎裂为三个氦原子核及一些最小电离粒子的三分裂事例进行了测量.对碎裂的机制进行了解释.认为相对论性氧原子核的这类碎裂现象为氧原子核的结团模型提供了直接的实验证据.     

CMOS器件60Co γ射线、电子和质子电离辐射损伤比较

利用TRIM95蒙特卡罗软件计算了质子在二氧化硅中的质量阻止本领和能量沉积，比较了质子在二氧化硅中的电离阻止本领与核阻止本领，分析了质子在材料的表面吸收剂量与灵敏区实际吸收剂量的关系.利用⁶⁰Co γ射线、1MeV电子和2—9 MeV质子对CC4007RH和CC4011器件进行辐照实验，比较⁶⁰Co γ射线和带电粒子的电离辐射损伤情况.实验结果表明，⁶⁰Co γ射线、1MeV 电子和2—7MeV质子辐照损伤效应中，在0V栅压下可以相互等效； 关键词： γ射线 电子 质子 辐射损伤     

相对论性核-核碰撞中的弹核碎裂过程

本文概括了14.6AGeV,60AGeV,200AGeV~(16)O,14.5AGeV~(28)Si和200AGeV~(32)S与固定靶碰撞的弹核碎裂过程的主要实验结果,分析了弹核电磁离解截面与弹核和靶核电荷大小及弹核能量间的关系,核反应截面与弹核和靶核大小及弹核能量间的关系,得到了弹核碎片的电荷分布、横动量分布和发射角分布以及α粒子多重数分布等规律,讨论了弹核碎裂过程包括电磁离解与核反应碎裂的机制,还评述了相对论性核-核碰撞中弹核碎片的次级作用问题。     

类锂离子C^3＋激发态（1s^2 2p）^2P光电离的计算

文中首次运用R—矩阵方法，在三态密耦近似下计算了类锂离子C^3 激发态(1s^2 2p)^2P光电离截面，主要给出了不同过程和不同分波的光电离截面。计算结果显示了光电离过程中非常丰富的Rydberg系列共振结构。     

2-甲基-6-(2-甲苯基)-2-庚烯的波谱学研究

采用色谱法从蒲儿根花部位中分离得到2-甲基-6-(2-甲苯基)-2-庚烯,该化合物第一次以单体的形式得到,通过测定氢-氢相关谱(1H-1H COSY)、DEPT谱、异核单量子相关谱(HSQC)及异核多键相关谱(HMBC)等二维谱确定了该化合物的结构,并对该化合物的1H NMR和13C NMR谱进行了归属.     

LiⅠ等电子序列[(1s2p)3P,4d]2P0及 [(1s2s)1S,5p]2P0自电离态的计算

利用鞍点复转动及全实加关联的方法,计算了LiⅠ等电子序列[(1s2p)3P,4d]2P0及[(1s2s)1S,5p]2P0自电离态的能量和宽度.计算结果中包括相对论修正和质量极化修正.文中讨论了自电离宽度随核电荷数Z的变化关系,同时也讨论了精细结构分裂值及相对论修正随核电荷数Z的变化关系.     

类锂体系(Z=21—30)基态1s22s电离能和相对论项能的理论计算

使用全实加关联方法和里兹(Ritz)变分方法计算了类锂体系(Z=21—30)基态1s²2s的非相对论能量和波函数；包括动能修正、电子-电子接触项、轨道-轨道相互作用项以及Darwin项的相对论修正和质量极化项由全实加关联波函数的一阶微扰给出，量子电动力学修正QED(quantum electronic dynamic)由有效核电荷方法和类氢公式计算；给出了中等核电荷的高电离类锂体系基态的电离能、相对论效应的项能(term energy)，并将计算结果与实验数据进行了比较，表明FCPC 关键词： 类锂体系 全实加关联 电离能 项能     

2D—NMR对皂皮酸—3—氧—葡萄糖醛酸^13C,^1H的完全指定—介绍HMBC和HOHAHA

HMBC是一种测定远程偶合~1H—~(13)C相关的十分灵敏的方法,特别适用于检测和甲基质子远程偶合(~2J,~3J)的碳.HOHAHA谱显示出多次Relay信息,选择适当参数可通过一次实验得到独立自旋体系中所有质子相关信息.本文用HMBC和HOHAHA实验结合同核(~1H)COSY和导核(~(13)C-~1H)COSY确认了Qwhaic acid—3—O—glucuronic acid分子中所有~(13)C和~1H的归属.     

Spatial dosimetry and spectrometry with neutron activation of remaining Ag from nuclear emulsion

Certain characteristics of nuclear emulsion make it suitable for dosimetric measurements in space. It serves as an integrating medium of all ionizing effects i.e. the total dose absorbed within the detector, which leads to developable grains. Their number or the mass of silver, remaining after processing can be determined by neutron activation of the Ag nuclides. Using emulsions with different sensitivity thresholds (Ilford K5÷K0) allows to differentiate to a certain degree LET-classes of the ionizing radiation, and to obtain a rough composition of the flux over a wide range of dose. The results of the calibration with gamma rays, protons and oxygen for emulsions of different sensitivities are given. Results from various space experiments (Bion 10, 1, , 2, 2) are presented too.     

柴油、乙醇和水三组元乳化液流变特性的研究

研究了柴油、乙醇和水三组元乳化液的流变特性。实验发现乳化液在本文的组分配比下近似为牛顿流体,而且乳化剂的种类、含量以及乳化液的组分等均对乳化液的流变特性具有显著的影响。对于组分相同的乳化液,乳化液的粘度随着乳化剂含量和粘度的增加而增加;当乳化剂的含量和粘度相同时,若乙醇和水之间的相对质量分数保持不变,减少乳化液中柴油的含量(柴油不少于50％),乳化液的粘度随之增加。但是,柴油、乙醇和水三组元乳化液的粘度要比柴油、甲醇和水三组元乳化液的粘度大2到3倍。     

The cosmic ray boron and carbon isotopic composition measured in nuclear emulsions

A study is made of the isotopic composition of primary cosmic ray boron and carbon in the energy interval 135–390 MeV/n. The quotients¹¹B/(¹⁰B +¹¹B) = 0.61 ±0.12 and¹³C/(¹²C +¹³C) = 0.06 ±0.04, valid at the top of the atmosphere, are obtained from photometric measurements on tracks found in an Ilford G5 emulsion stack exposed to the radiation.     

NMR Q-space microscopy of concentrated oil-in-water emulsions

The pulsed field gradient stimulated echo technique with selective excitation is used to probe the diffusion of water in the continuous phase of concentrated oil-in-water emulsions. The dependence of the echo amplitude, S(q,Delta), on wavevector, q, and diffusion time, Delta, shows that the water diffusion propagator is sensitive to emulsion microstructure. This is analyzed using a multiple exponential time series expansion of S(q,Delta) in Delta, with wavevector dependent expansion coefficients. These coefficients are compared with predictions from several theoretical models for three types of stable emulsion, each differing in microstructure. The relationship between the nuclear magnetic resonance q-space measurements and bulk rheology for all three types of emulsion is also explored.     

Track theory and nuclear photographic emulsions for Dark Matter searches

This work is devoted to the analysis of possibilities of nuclear emulsions for Dark Matter search, particles of which can produce slow recoil-nuclei. Tracks of such recoil-nuclei in developed nuclear emulsion consist from several emulsion grains. The analysis was carried out with Monte-Carlo calculations made on the basis of the Track Theory and the various factors influencing Dark Matter particles registration efficiency were investigated. Problems, which should be solved for optimal utilization of nuclear emulsions in Dark Matter search, were formulated."Body     

Enhanced creaming of milk fat globules in milk emulsions by the application of ultrasound and detection by means of optical methods

The effects of application of ultrasonic waves to recombined milk emulsions (3.5% fat, 7% total solids) and raw milk on fat destabilization and creaming were examined. Coarse and fine recombined emulsions (D[4,3]=9.3 μm and 2.7 μm, respectively) and raw milk (D[4,3]=4.9 μm) were subjected to ultrasound for 5 min at 35°C and 400 kHz or 1.6 MHz (using a single transducer) or 400 kHz (where the emulsion was sandwiched between two transducers). Creaming, as calculated from Turbiscan measurements, was more evident in the coarse recombined emulsion and raw milk compared to that of the recombined fine emulsion. Micrographs confirmed that there was flocculation and coalescence in creamed layer of emulsion. Coalescence was confirmed by particle size measurement. These results imply that ultrasound has potential to pre-dispose fat particles in milk emulsions to creaming in standing wave systems and in systems with inhomogeneous sound distributions.     

Spatially resolved emulsion droplet sizing using inverse Abel transforms

Pulsed field gradient (PFG) nuclear magnetic resonance (NMR) is well established as a tool for determining emulsion droplet-size distributions via measurement of restricted self-diffusion. Most measurements made to date have not been spatially resolved, but have measured an average size distribution for a certain volume of emulsion. This paper demonstrates a rapid method of performing spatially resolved, restricted diffusion measurements, which enables emulsion droplet sizing to be spatially resolved as a function of radius in cylindrical geometries or pipes. This is achieved by the use of an Abel transform. The technique is demonstrated in various annular systems containing two emulsions, with different droplet-size distributions, and/or a pure fluid. It is also shown that by modifying the pulse sequence by the inclusion of flow-compensating magnetic field gradients, the technique can measure spatially resolved droplet-size distributions in flowing emulsions, with potential applications in spatially resolved on-line droplet-size analysis.     

Ferulic acid loaded pickering emulsions stabilized by resistant starch nanoparticles using ultrasonication: Characterization,in vitro release and nutraceutical potential

The use of starch based nanoparticles have gained momentum in stabilizing pickering emulsions for it’s numerous advantages. In present study resistant starch (RS) was isolated from lotus stem using enzymatic digestion and subjected to nanoprecipitation and ultrasonication to yield resistant starch nanoparticles (RSN). RSN of varying concentrations (2%, 10% and 20%) were used to stabilize the flax seed-oil water mixture to form pickering emulsions. The emulsions were used to nanoencapsulate ferulic acid (FA) – a well known bioactive via ultrasonication. The emulsions were lyophilized to form FA loaded lyophilized pickering emulsion (FA-LPE). The FA-LPE (2%, 10 % and 20%) were characterized using dynamic light scattering (DLS), light microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and attenuated total reflectance fourier transform infra-spectroscopy (ATR-FTIR). AFM showed FA-LPE as spherical droplets embedded in the matrix with maximum peak height of 8.47 nm and maximum pit height of 1.69 nm. SEM presented FA-LPE as an irregular and continuous surface having multiple folds and holes. The ATR-FTIR spectra of all the samples displayed peaks of C = C aromatic rings of FA at 1600 cm⁻¹ and 1439 cm⁻¹, signifying successful encapsulation. In vitro release assay displayed more controlled release of FA from FA-LPE (20%). Bioactivity of FA-LPE was evaluated in terms of anti-cancer, anti-diabetic, angiotensin converting enzyme (ACE) inhibition and prevention against oxidative damage under simulated gastro-intestinal conditions (SGID). The bioactivity of FA-LPE (20%) was significantly higher than FA-LPE (2%) and FA-LPE (10%). Key findings reveal that pickering emulsions can prevent FA under harsh SGID conditions and provide an approach to facilitate the design of pickering emulsions with high stability for nutraceutical delivery in food and supplement products.     

Analysis of Transition Mechanism of Cubic Boron Nitride Single Crystals under High Pressure-High Temperature with Valence Electron Structure Calculation

The possibilities of hexagonal boron nitride(hBN) and lithium boron nitride(Li_3BN_2) transition into cubic boron nitride(cBN) under synthetic pressure 5.0 GPa and synthetic temperature 1700 K are analyzed with the use of the empirical electron theory of solids and molecules. The relative differences in electron density are calculated for dozens of bi-phase interfaces hBN/cBN, Li_3BN_2/cBN. These relative differences of hBN/cBN are in good agreement with the first order of approximation(10%), while those of Li_3BN_2/cBN are much greater than 10%.This analysis suggests that Li_3BN_2 is impossible to be intermediate phase but is a catalyst and cBN should be directly transformed by hBN.