New developments at nuclear emulsion experiment

Three new nuclear cmulsion techniques used for measuring emission angles ofcharged particles in central events at ultra-high evergy heavy-ion collisions are fully described.

Forward-backward multiplicity correlations 4.5 A GeV/c ^16O-emulsion interactions

A detailed study of the mechanisms of the emissions of pions and protons in the forward and backward hemispheres in 4.5 A GeV/c oxygen-emulsion interactions has been carried out. The correlations between the multiplicities of secondary charged particles in the backward and forward hemispheres are investigated.

Features of the total disintegration events of heavy emulsion targets caused by 4.5 A GeV/c ^16O

Total disintegration events produced by 4.5 A GeV/c ^16O-AgBr interactions are analysed to investigate the characteristics of secondary charged particles produced in such collisions. The multiplicity distributions of grey, black, and relativistic charged particles can be well represented by Gaussian distribution. The average multiplicity of grey particles is found to increase with the mass of projectile increasing, while that of black particles is found to decrease with the mass of projectile increasing. This result is in good agreement with the prediction of fireball model. Finally, the linear dependence between grey and black particles is observed, but there is no distinct dependence between the production of relativistic charged particles and the target excitation.

Intermittency in 3.7 A GeV ^16O-emulsion interactions

The intermittency effect has been studied for an interaction of 3.7 A GeV ^16O with emulsion using the distributions of both the pseudorapidity intervals and the azimuthal angle intervals of the shower particles emitted in a central rapidity region. The scaled factorial moments, reduced scaled factorial moments and multifractal moments as functions of the bin size in pseudorapidity and in azimuthal angle have been calculated and have revealed the presence of an intermittent behaviour which may be due to the random cascading property of the reaction. The anomalous fractal dimension has been found to increase with the increase of rank of the moment.

Fragmentation in ^16 O-emulsion interactions at 3.7 A GeV

The topology of ^16 O fragmentation at 3.7 A GeV in reactions with emulsion nuclei is presented. The multiplicity distributions of projectile fragments, charged secondaries and their dependences on the projectile residues are discussed.

Evidence of self-affine multiplicity fluctuation of particle production in ^84Kr-emulsion interactions at 1.7 A GeV

Self-affine multiplicity fluctuation is investigated by using the two-dimensional factorial moment methodology and the concept of the Hurst exponent （H）. Investigation on the experimental data of compound particles and target fragments emitted in ^84Kr-AgBr interactions at 1.7 A GeV reveals that the best power law behaviours are exhibited at H=0.7 and 0.6 respectively, and the data for shower particles produced in ^84Kr-emulsion interactions at 1.7 A GeV indicate that the best power law behaviour occurs at H=0.6, all of which show the self-affine multiplicity fluctuation patterns. The multifractality and the non-thermal phase transition occurring during producing the compound particles, the target fragments, and the shower particles in the ^84Kr -AgBr interaction and the ^84Kr-emulsion interaction are also discussed. The multifractality is observed during producing compound particles, target fragments, and shower particles. In the target fragment production, an evidence of non-thermal phase transition is observed, but in the shower particle production and the compound particle production, no evidence of non-thermal phase transition is observed.

Helium production from ^84Kr- and ^197Au-emulsion interactions at high energies

The properties of the relativistic helium fragments produced in interactions of ^84Kr at 1.8 A GeV and ^197Au at 10.7 A GeV in emulsion are investigated. The experimental results are compared with those obtained from various projectiles with emulsion collisions at different energies. It is found that the multiplicity distribution of helium projectile fragments （HPFs） is well described by the Koba-Nielsen Olesen （KNO） scaling presentation. The second Mueller moment f2 of the HPF multiplicity distribution is independent of the projectile energy for the same projectile, but it is dependent on the projectile mass number. The value of f2 increases with the increase of projectile mass number Ap. The negative value of f2, when Ap 〈 69, means that the emission of HPFs is anticorrelated, but positive value of f2, when Ap 〉 69, refers to that the emission of HPFs is correlated. The non-zero f2 moment in this experiment implies the strong correlation existing between the HPFs.

Single source emission of proton projectile fragments in nucleus-emulsion interactions

The projected angular distribution and transverse momentum distribution of proton projectile fragments produced in 3.7A GeV 160, 500A MeV 56Fe, and 1.7A GeV S4Kr induced by different kinds of emulsion target （H, CNO, and AgBr） interactions are investigated. It is found that the projected angular distribution and transverse momentum distribution can be well represented by a single Gaussian distribution. Comparison of transverse momentum distribution with the Maxwell-Boltzmann distribution reveals that proton projectile fragments are emitted from a single-temperature emission source. The temperature is different for different colliding systems, and linearly depends on the target size.

Interaction of 28Si with Emulsion Nuclei at 4.5 AGeV/c in View of Thermo-Statistical Approach

In this work, we study some changes of nuclear matter in the interactions of 28Si with emulsion nuclei at 4.5 AGeV/c. From the experimental quantities investigated using Tsallis’ statistics, we deduced the temperature, entropy density and non-equilibrium factor of the nuclear medium. These obtained parameters were used to reveal variations in the nuclear matter at the stated interaction energy. The results that came up from this study were compared with their corresponding results obtained from other heavy ion collision experiments at wide energy range.

ABS接枝粉料结构及抗氧剂用量对ABS树脂性能的影响

采用乳液接枝聚合技术,制备了核壳比为60/40、70/30且接枝过程中引发剂用量不同的ABS接枝共聚物胶乳,系统研究了丙烯腈⁃丁二烯⁃苯乙烯塑料(ABS)壳层厚度及水性抗氧剂用量对ABS接枝共聚物热氧老化性能的影响,同时通过熔融共混技术生产ABS树脂,测试了水性抗氧剂加入量和ABS壳层厚度对ABS树脂力学性能和表观性能的影响。研究表明:ABS壳层越薄,其ABS接枝共聚物的热氧老化性能越差。ABS壳层厚度对树脂冲击强度和表观性能均有影响。本研究使用的水性抗氧剂加入量在胶乳总重的1%(质量分数,下同)以下时,水性抗氧剂加入量越高,ABS接枝共聚物的氧化诱导期和氧化诱导温度越高。抗氧剂加入量在0.75%时,抗热氧老化能力达到较高水平。抗氧剂加入量对ABS树脂的力学性能无影响,对其表观性能如白度、黄色指数影响明显。

鸦胆子油乳注射液对结肠炎相关性结直肠癌小鼠的作用及机制研究

目的:建立结肠炎相关性结直肠癌(CAC)小鼠模型,研究鸦胆子油乳注射液(BJOEI)的抗癌作用及机制。方法:将60只SPF级C57BL/6雄性小鼠随机分为正常组、模型组、阿司匹林组和BJOEI低、中、高剂量组,每组10只。除空白组外,各组小鼠均采用氧化偶氮甲烷(AOM)和葡聚糖硫酸钠(DSS)诱导CAC小鼠模型,从第3周开始,各组予以相应药物治疗,阿司匹林组25 mg/kg灌胃,BJOEI低、中、高剂量组分别以1.5 mL/kg、3.0 mL/kg、4.5 mL/kg剂量腹腔注射BJOEI,空白组和模型组腹腔注射等体积生理盐水,1次/d,连续给药10周后取材并记录结直肠肿瘤个数,计算脾脏指数;HE染色观察小鼠的结肠组织病理变化,并进行病理学评分;ELISA法检测小鼠血清白细胞介素(IL)-6水平;免疫组化检测结肠组织Ki67、肿瘤坏死因子(TNF)-α和血管内皮生长因子(VEGF)的表达;Western blot检测结肠组织磷酸化核因子-κB(p-NF-κB)/NF-κB蛋白相对表达量。结果:与模型组相比,BJOEI低、中、高剂量组肠道肿瘤个数和脾脏指数均减少,有统计学意义(P<0.05),肠组织病理学评分和Ki67、TNF-α、VEGF、p-NF-κB/NF-κB表达水平均降低,有统计学意义(P<0.05),BJOEI中、高剂量组血清IL-6水平降低,有统计学意义(P<0.05)。结论:BJOEI可能通过抑制NF-κB通路来减轻肠黏膜炎症反应发挥抗CAC作用。

宇宙线相关的诺贝尔物理学奖

20世纪初,物理学家在对大气导电性的研究中发现了宇宙线,时至今日,宇宙线的发现已过百年.宇宙线是指来自宇宙空间的高能粒子,是人类能够获得的来自太阳系以外的唯一物质样品,包括原子核、电子、光子和中微子,以及其它目前尚未被探测到的未知粒子,它们主要来自宇宙空间中的宇宙线源或者是宇宙线在传播时与空间物质相互作用的产物.在现代物理学发展史中,宇宙线的研究占有重要地位,许多新粒子都是首先在宇宙线研究中发现的,且目前人类已知的最高能量的粒子也来自于宇宙线的观测.作为联系微观粒子和宏观宇宙的桥梁,宇宙线研究既对粒子物理也对天体物理做出了重要贡献.本文重点梳理了在宇宙线研究过程中,荣获的诺贝尔物理学奖,详细介绍了其实验原理、实验仪器和实验成果.

1.7 AGeV ^(84)Kr诱发乳胶核反应慢粒子产生

对1.7 AGeV 84Kr诱发乳胶核反应慢粒子产生进行研究。实验结果表明,黑径迹粒子、灰径迹粒子和重电离粒子平均多重数随碰撞中心度及靶核大小的增加而增加;灰径迹粒子和重电离粒子平均多重数随黑径迹粒子数的增加而增加;重电离粒子平均多重数随灰径迹粒子数的增加而增加,而黑径迹粒子平均多重数随灰径迹粒子数的增加表现出先增加后趋于饱和的趋势;灰径迹粒子平均多重数随重电离粒子数的增加而增加,而黑径迹粒子平均多重数随重电离粒子数的增加表现出先增加后趋于饱和。以上结果均可利用核碰撞几何模型来解释。

三元复合驱驱油机理及乳液渗流规律NMRI研究

通过先进的实验手段—核磁共振成像技术(即Nuclear Magnetic Resonance Imaging,简称NMRI),首先阐述了三元复合驱驱油过程的微观机理,既而在此基础上从细观水平实验研究了原油/三元复合体系乳状液的流变性,进而揭示了其在多孔介质中的渗流规律,最后建立了原油/三元复合体系乳状液在多孔介质中渗流的数学模型,实验结果表明与理论分析结论基本吻合,说明所建数学模型是合理的。

新全球动力学理论与壳幔的形成

地壳从地幔中熔融出来是地质学立论的基础 ,也是板块构造运动的基本原因。上述理论阐明不了大陆岩石圈、大陆造山带的组成 ,结构与演化 ,也与当代的基础理论不尽吻合。为此特提出在地球自转速度变化制约下的多层扭动涡旋甩出说———核幔壳“风暴”所引发的热核反应是地球发展与演化的唯一的、统一的“动力”来源 ,也是壳幔形成的根本原因。

深部天然核反应堆——一种可能的山脉隆升动力源

板块碰撞造山模式难以解释造山作用在时间上的“滞后”和在空间上的“差位”现象。大量研究表明山脉隆升的动力来自深部,因此,探索深部地质过程的物理和化学机制及其导致的能量再分配是认识山脉隆升动力学机制的关键。若干线索表明地幔中的核反应可能在岩石圈动力学演化过程中起过不可忽视的作用。通过分析U、Th等元素的地球化学性质及其在深变质过程中的行为,认为伴随板块俯冲发生的陆壳物质向地幔的再循环有可能在软流圈顶部形成富含U、Th、K等放射性亲石元素和碳质(石墨)的地质体。通过理论上的论证和对Oklo天然核反应堆遗迹的反演表明这些地质体可能有一部分具备了形成天然石墨核反应堆的条件。这种反应堆在亚临界状态下的断续运行有可能为其上方岩石圈中的岩浆作用提供热源,进入超临界状态时将可能导致深部核爆炸,成为地震、火山爆发和岩石圈破裂的动力来源。据此建立的山脉隆升的动力学初步模式,可以解释造山带的形成、高原的隆升、深源地震及其前兆的成因和金刚石及其相关岩石在地壳浅部置位的机制。

高能核乳胶室的数控测量

西欧核子研究中心的CERN/SPS加速器上能量高达每核子200GeV的氧和硫离子束流运行,开辟了研究超相对论核-核作用的新能区,本文报告了最近建立的一套核乳胶室数控测量装置,它可以有效地测量这个新能区的重离子诱发核反应的高多重数中心事件。

新型的核乳胶探测技术

介绍了三种可以准确、快速、半自动（全自动）测量的核乳胶实验新技术。这些技术特别适合于测量超高能重离子碰撞中心事例中带电粒子的发射角。

超高压处理对低脂乳化肠水分分布及微观结构的影响

以低脂乳化肠为材料,对0.1、100、200、300 MPa处理组进行保水性、低场核磁共振检测和扫描电子显微镜观察,并进行主成分分析,从水分子弛豫特性变化和微观结构角度揭示高压改善低脂乳化肠保水性的原因。结果表明:与对照组相比,压强从100 MPa增大到300 MPa时,结合水和不易流动水比例显著增加,自由水比例显著减少(P<0.05),其中200 MPa处理组水分分布情况最佳;扫描电子显微镜观察结果显示各组低脂乳化肠微观结构存在明显差异,超高压处理显著增加了凝胶结构中孔隙数量和大小;主成分分析表明保水性、微观结构和水分分布密切相关。因此,适当的超高压处理可以改善乳化肠的微观结构,降低凝胶水分分布中自由水含量,提高低脂乳化肠的保水性。

4.5 AGeV/c ^(16)O-Em作用末态产生粒子前后关联研究

介绍了 4 5AGeV/c16O Em作用末态产生粒子的多重数分布 ;讨论了簇射粒子、灰径迹粒子和黑径迹粒子向前后半球内发射的关联。实验结果表明 :簇射粒子、灰径迹粒子在前后半球内的分布明显不同 ,而黑径迹粒子多重数在前后半球内的分布并无显著差别 ;在前半球内 ,簇射粒子及灰粒子数随后半球内的簇射粒子及灰粒子数的增加明显增加 ,且增加幅度随束流质量的增加而提高 ;后半球内的簇射粒子及灰粒子平均多重数随前半球内的簇射粒子及灰粒子数的增加而增加 ,但增加的幅度随射弹质量的增加而减弱。