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71.
快重离子在凝聚态物质中引起的效应——电子能损效应   总被引:3,自引:2,他引:1  
简述了快重离子在凝聚态物质中引起的效应——电子能损效应,主要包括缺陷的产生和潜径迹的形成、各向异性的塑性形变、由弹性碰撞产生的缺陷的部分退火、相变(非晶化),以及尝试性的理论解释.  相似文献   
72.
A series of esters of R-tetrahydrothiazo-2-thione-4-carboxylic acid[R-TTCA] was synthesized by direct esterification of R-TTCA with alcohols(CH3OH,C2H5OH,n-C3H7OH,i-C3H7OH,n-C4H9OH,sec-C4H9OH)in the presence of TiCl4 as the catalyst at room temperature without using any other solvent or dehydrant in high yields,91.6%-99.1% for primary alcohols and 55%- 80% for secondary alcohols.The catalyst has a strong chemoselective activity for the esterification of primary alcohols with R-TTCA in the presence of secondary alcohols.Owing to high yield,high chemoselectivity,and mild conditions used,this is an efficient method for the esterification of primary alcohols with R-TTCA.  相似文献   
73.
有机钼及其复合纳米润滑添加剂的摩擦磨损性能研究   总被引:11,自引:1,他引:11  
采用X-P型销-盘摩擦磨损试验机和MRS-10J型四球摩擦磨损试验机考察了N68MD、N68ME、N68和SAE404种含有机钼及其复合纳米润滑添加剂的润滑油的摩擦磨损性能,分别采用扫描电子显微镜和电子衍射能量谱仪分析了摩擦副的磨损形貌及其磨损表面元素分布情况.结果表明:在N68MD润滑时,钢/钢摩擦副具有较低的摩擦系数和磨损量,并且具有良好的抗极压性能;在N68ME润滑时,钢/钢摩擦副除了表现出很小的摩擦系数和良好的抗极压性能以外,还表现出优异的自修复功能,这是由于有机钼与纳米铜协同作用的结果.  相似文献   
74.
建立了急性淋巴细胞白血病患儿血液中红细胞中的硫嘌呤甲基转移酶活性(TPMT)的HPLC测定法。采用反相高效液相色谱法直接测定酶促反应的产物浓度,从而计算红细胞中TPMT的活性。以S-腺苷-L-甲硫氨酸(SAM)作为甲基供给体,6-硫鸟嘌呤(6-TG)作为酶反应底物,TPMT催化6-TG生成2-氨基-6-甲基巯基嘌呤(6-MTG),采用HClO4溶液终止反应及沉淀蛋白,分离上清液进行色谱分析。色谱柱为AichromBond-1 C18柱(5μm,4.6mm i.d.×150mm);等梯度洗脱,流动相为V(乙腈)∶V(0.01mol/L磷酸钾缓冲溶液)=6∶94(用HCl调pH2.74),荧光检测器检测,激发波长为310nm,发射波长为390nm。结果表明,6-MTG在0~250μg/mL范围内呈良好的线性关系,相关系数r=0.9999,检出限为0.093μg/L(S/N=3),回收率为81.4%~106.3%。方法能用地巯基嘌呤类药物药代研究和临床用药监测常规分析。  相似文献   
75.
简要介绍了高能重离子在金属材料中引起辐照效应的主要理论 ,特别是与电子能损引起的缺陷产生与演化、离子潜径迹形成、辐照相变以及各向异性塑性形变等效应相应的理论描述.Experimental results showed that, for high energy heavy ion irradiations, electronic energy loss could play a dominant role in damage process in solid materials. In order to explain the experimental phenomena and results, a series of theoretical models based on Coulomb explosion or thermal spike mechanisms have been proposed. In the present paper, more attention was paid to theoretical expressions of high energy heavy ion irradiation induced effects in metallic materials ...  相似文献   
76.
用能量 50 - 1 1 0 ke V的 N离子在低于 80°C温度下注入 CVD法合成的金刚石薄膜后 ,分别用 X射线光电子谱、红外谱和拉曼谱检测注入后的薄膜中是否形成了 C- N化合物 .结果表明注入后的薄膜中存在有 3种化学键态的 C- N化合物 ,且低能离子注入更有利于 C- N化合物的形成 .由于在注入区内形成了大量的 C- N单键 ,这有利于β- C3N4 的合成 .对 C- N化合物薄膜的场发射特性也做了研究.Diamond films were implanted with 50-110 keV N ions to the dosage of 1×10 17 ions/cm 2 at the temperature below 80 °C . The possibility of the formation of C N compounds in diamond films was investigated by means of X ray photoelectron spectroscopy (XPS), X ray diffraction analysis (XRD), Fourier transform infrared absorption spectroscopy (FTIR) and Raman spectroscopy. New evidence has been presented that plenty of C-N single bonds which are necessary ...  相似文献   
77.
In this paper, we present a scheme for quantum dialogue by using a four-qubit cluster state as quantum channel.The scheme has two cases: Case 1, Sender Alice and receiver Bob share information using an orderly sequence of entangled state as quantum channel which was prepared by Alice. This case is achieved as follows: The two sides agreed to encode quantum state information, then Alice perform a bell state measurement for quantum information which has been encoded. This will convey the information to Bob, then Bob measuring his own qubits, through the analysis of the measurement results of Alice and Bob, Bob can obtain quantum information. For case 2, four-qubit cluster state and quantum state information is transmitted to form a total quantum system. In the Case 2 scenario, Alice and Bob perform bell state measurements for part of the qubits, and tell the measurement result to each other through the classical channel. Finally, according to the measurement result, Alice and Bob operate an appropriate unitary transformation, as a result, Alice’s qubit will be renewed upon Bob’s measurements, and also, Bob’s qubit will be renewed upon Alice’s measurements. Thus, a bidirectional quantum dialogue is achieved. After analysis, this scheme has high security by taking certain eavesdropping attacks into account. There is therefore a certain reference value to the realization of quantum dialogue.  相似文献   
78.
室温下用80keVN离子注入ZnO薄膜样品,注量分别为5.01014,5.01015和5.01016ions/cm2,然后用X射线衍射和透射电镜技术对样品的结构特性进行了表征。实验结果表明,由高度(002)择优取向的致密柱状晶构成的薄膜中,注入5.0×1015ions/cm2时,观测到缺陷生成和局域无序化现象,但薄膜总体结构仍保持柱状晶和(002)择优取向;随着注量的增大,晶格常数c和压应力呈增大趋势。对注入N离子对ZnO薄膜结构特性的影响机理进行了简单的讨论。  相似文献   
79.
〗采用磁控溅射技术在Si衬底上沉积Si/\[Fe(10 nm)/Nb(4 nm)/Fe(4 nm)/Nb(4 nm)\]2/ \[Fe(4 nm)/Nb(4 nm)\]4多层膜。 用2 MeV的 Xe离子在室温下辐照多层膜。采用俄歇深度剖析、X射线衍射和振动样品磁强计分析辐照引起的多层膜元素分布、 结构及磁性变化。AES深度剖析谱显示当辐照注量达到1.0×1014 ions/cm2时, 多层膜界面两侧元素开始混合; 当辐照注量达到2.0×1016ions/cm2时, 多层膜层状结构消失, Fe层与Nb层几乎完全混合。XRD谱显示, 当辐照注量达到1.0×1014ions/cm2时, Nb的衍射峰和Fe的各衍射峰的峰位相对于标准卡片向小角方向偏移, 这说明辐照引起Nb基和Fe基FeNb固溶体相的形成;当辐照注量大于1.0×1015 ions/cm2时, 辐照引起非晶相的出现。 VSM测试显示,多层膜的磁性随着结构的变化而变化。 在此实验基础上, 对离子辐照引起界面混合现象的机理进行了探讨。The behavior of the metallic multilayers of Si/\[Fe(10 nm)/Nb(4 nm)/Fe(4 nm)/ Nb(4 nm)\]2/\[Fe(4 nm)/Nb(4 nm)\]4 under 2 MeV Xe ion irradiation has been investigated by depth profile analysis of Auger electron spectroscopy,X ray diffraction and vibrating sample magnetometer. The obtained experimental results show that the inter mixing between Fe and Nb layers occurs in the 1.0×1014 ions/cm2 irradiated multilayer sample which results in the formation of Nb based and Fe based FeNb solid solution. For the samples irradiated to fluence larger than 1.0×1014 ions/cm2, amorphisation is observed, and moreover, the layered structure of the multilayer samples is broken up completely for the samples under 1.0×1016 or 2.0×1016 ions/cm2 irradiation. Vibrating sample magnetometer measurement also reveals that the magnetization of the samples changes with the evolution of the structure of multilayers. Possible mechanism of the modification in Fe/Nb multilayers induced by Xe ion irradiation is briefly discussed.  相似文献   
80.
自从20世纪50年代开始利用微束辐照生物活细胞以来,由于微束独特的辐照特征, 其在生物学、 材料学、 生物医学、航空航天科学、环境科学、地质学、微加工等领域得到了广泛的应用。 在前人大量研究的基础上, 对微束装置及其应用进行总结概括。 展望了微束的发展趋势并简单介绍中国科学院近代物理研究所正在兴建的中高能重离子微束辐照装置。 Collimated proton microbeam has been used to irradiate the biological living cells since 1850s. Due to its unique characteristic in irradiation, microbeam has been extensively applied to many research fields,such as biology, material science, biomedicine,aeronautics and stronautics, environmental science, geology,micromachining and so on. Based on the much research of predecessors, the microbeam facilities and their corresponding applications are summarized in this paper. At last,prospects on the development trend of microbeam are made, and the intermediate energy and high energy heavy ion microbeam irradiation facility being constructed at the Institute of Modern Physics of Chinese Academy of Sciences is briefly introduced.  相似文献   
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