Ar+注入对UHMWPE摩擦学性能的影响

采用离子注入技术对超高分子聚乙烯（UHMWPE）进行了Ar＋注入表面改性,采用光学显微镜（OM）、原子力显微镜（AFM）和傅里叶变换红外光谱（FT-IR）观察和测定了Ar＋注入UHMWPE表面特性。采用万能磨损试验机考察了不同剂量Ar＋注入后UHMWPE的摩擦磨损性能。结果表明：Ar＋注入改变了UHMWPE表面颜色、形貌和微观的分子结构,提高了表面硬度和弹性模量。在干摩擦及去离子水润滑条件下,Ar＋注入后UHMWPE耐磨性能得到了明显的提高,且效果随剂量的增加而增强,然而伴随着摩擦系数增大。     

Ar离子束辐照下多壁碳纳米管网络的导电性增强

用Ar离子束辐照800K高温下的多壁碳纳米管(MWCNT)网络,注量为2×1016/cm2时,MWCNT网络的导电性提高～80%。实验结果表明,离子束辐照可通过在多壁碳纳米管间的引入连接改善多壁碳纳米管间的电学接触,制备高导电性的透明碳纳米管网络。     

低能氮离子注入对大豆幼苗脂质过氧化的影响

用N+注入丰豆101的种子,采收子叶伸展后24h和96h的幼苗做为试验材料,研究N+注入对其幼苗过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性以及氧化产物丙二醛(MDA)的含量、电解质外渗率的影响。结果表明,在25keV能量下,当N+注量在6.5×1016-7.8×1016N+/cm2时,幼苗的SOD和CAT活性最高。 而POD活性在小于5.2×1016N+/cm2低剂量下, 活性较恒定, 在大于5.2×1016N+/cm2中高剂量下,活性逐渐增大。此外,N+注入还可降低幼苗子叶中的MDA积累量和电解质外渗率,而且在6.5×1016N+/cm2剂量下,幼苗中的MDA含量和电解质外渗率最低。揭示了一定剂量N+注入大豆种子可削弱幼苗脂质过氧化作用以及提高其抗寒性的关系。     

Optical behaviour of Er doped rutile by ion implantation

Rutile single crystals were implanted at room temperature with fluences of 5 × 10¹⁵ Er⁺/cm² ions with 150 keV energy. Rutherford backscattering/channeling along the 0 0 1 axis reveals complete amorphization of the implanted region. Photoluminescence reveals the presence of an optical centre close to the intra-ionic emission of Er³⁺ in the as-implanted samples. After annealing at 800 °C in air no changes were observed in the aligned RBS spectrum. On the contrary, annealing in reducing atmosphere (vacuum) induces the epitaxy of the damage layer. These results are unexpected, since for implantations of other ions under the same conditions, epitaxial recrystallization of the damage region occurs at this temperature. On the other hand, photoluminescence studies show the presence of new Er-related optical centres with high thermal stability in the samples annealed under oxidizing conditions. Annealing at 1000 °C in vacuum leads to the complete recrystallization of the damaged region. At this temperature a large fraction of Er segregates to the surface.     

Effect of Fe ion implantation on tribological properties and Raman spectra characteristics of diamond-like carbon film

1 Introduction It is well known that DLC (diamond-like carbon)prepared by physical vapor deposition, plasma en-hanced chemical vapor deposition (PECVD) and otherplasma processing is an amorphous carbon materialcontaining sp2 and sp3 bonded carbon atoms. DLCfilm possesses some interesting properties, such ashigh hardness and Young's modulus, chemical inert-ness and low friction coefficient. The property andstructure of DLC film can be modified by addingsome metals. Ion implantation…     

Effects of ion implantation on poly(dimethylsilylene-co-methylphenylsilylene)

The effects of ion implantation on the electrical and structural properties of poly(dimethylsilylene-co-methylphenylsilylene), (DMMPS) thin films have been investigated. Ionic species of krypton, arsenic, fluorine, chlorine, and sulfur were implanted at energies ranging from 35 to 200 keV and with doses of up to 1 × 10¹⁶ ion cm². The conductivity of the polymer increased upon implantation reaching a maximum value of 9.6 × 10⁻⁶ (Ω cm)⁻¹ for the case of arsenic ion at a dose of 1 × 10¹⁶ ion cm² and energy of 100 keV. The results showed that ion implantation induced conduction in DMMPS was primarily due to structural modifications of the material brought about by the, energetic ions. Infrared analysis and Auger electron spectroscopy showed evidence for the formation of a silicon carbide-like structure upon implantation.     

Formation of Au nanoparticles in sapphire by using Ar ion implantation and thermal annealing

In this paper, we present results of the synthesis of gold nanoclusters in sapphire, using Ar ion implantation and annealing in air. Unlike the conventional method of Au implantation followed by thermal annealing, Au was deposited on the surface of m- and a- cut sapphire single crystal samples including those pre-implanted with Ar ions. Au atoms were brought into the substrate by subsequent implantation of Ar ions to form Au nanoparticles. Samples were finally annealed stepwisely in air at temperatures ranging from 400 to 800 °C and then studied using UV-vis absorption spectrometry, transmission electron microscopy and Rutherford backscattered spectrometry. Evidence of the formation Au nanoparticles in the sapphire can be obtained from the characteristic surface plasmon resonance (SPR) absorption band in the optical absorption spectra or directly from the transmission electron microscopy. The results of optical absorption spectra indicate that the specimen orientations and pre-implantation also influence the size and the volume fraction of Au nanoparticles formed. Theoretical calculations using Maxwell-Garnett effective medium theory supply a good interpretation of the optical absorption results.     

离子注入对电器触头性能的影响

对两种电器触头注入1×10~(17)/cm~2的氮离子,然后做低压电器通断试验,测量了触头的重量损失、温升、接触电阻、触头材料转移等参数,发现离子注入方法处理对电器触头性能有不同程度的改善。     

Structure and tribological performance of helium-implanted layer on Ti6Al4V alloy by plasma-based ion implantation

The present paper concentrates on tribological performance of Ti6Al4V alloy treated by helium plasma-based ion implantation with a voltage of −30 kV and a dose range of 1, 3, 6 and 9 × 10¹⁷ He/cm². X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM) and Atomic force microscopy (AFM) were used to characterize composition, structure and surface morphology, respectively. The variation of hardness with indenting depth was measured and tribological performance was evaluated. The uniform cavities with a diameter of several nanometers are formed in the helium-implanted layer on Ti6Al4V alloy. Helium implantation enhances the ingress of O, C and N and produces TiO₂, Al₂O₃, TiC, TiN in the near surface layer on their removal from the vacuum and exposure to normal atmospheric condition. In the near surface layer, the hardness of implanted samples increases remarkably comparing with the untreated sample, and the maximum peak increasing factor is up to 2.9 for the sample implanted with 3 × 10¹⁷ He/cm². A decrease in surface roughness, resulting from the leveling effect of sputtering and re-deposition during implantation, has also been observed. Comparing with the untreated sample, implanted samples have a good wear resistance property. And the maximum increase in wear resistance reaches over seven times that of the untreated one for the sample implanted with 3 × 10¹⁷ He/cm². The wear mechanism of implanted samples is abrasive-dominated.     

N+离子注入对锆-4合金耐腐蚀性能的影响

为了研究N+离子注入对锆-4合金耐腐蚀性能的影响,本文使用直线加速器产生的N+离子注入锆-4合金样品,通过对离子注入后样品电化学曲线的测量,分析不同剂量下N+离子注入对锆-4合金钝化电流密度的影响,同时使用透射电子显微镜分析注入层的微观结构.结果表明,随着注入剂量的提高(0-1×1016cm-2),样品钝化电流密度下降,耐腐蚀性能提高,其原因主要归结于样品表层由多晶结构到非晶结构的转变过程.     

Er+ medium energy ion implantation into lithium niobate

Erbium-doped lithium niobate (Er:LiNbO₃) is a prospective photonics component, operating at 1.5 μm, which could find its use chiefly as an optical amplifier or waveguide laser. In this study, we have focused on the properties of the optically active Er:LiNbO₃ layers, which are fabricated by medium energy ion implantation under various experimental conditions. Erbium ions were implanted at energies of 330 and 500 keV with fluences of 1.0 × 10¹⁵, 2.5 × 10¹⁵ and 1.0 × 10¹⁶ cm^?2 into LiNbO₃ single-crystalline cuts of various orientations. The as-implanted samples were annealed in air at 350 °C for 5 h. The depth distribution and diffusion profiles of the implanted Er were measured by Rutherford Backscattering Spectroscopy (RBS) using 2 MeV He⁺ ions. The projected range R_P and projected range straggling ΔR_P were calculated employing the SRIM code. The damage distribution and structural changes were described using the RBS/channelling method. Changes of the lithium concentration depth distribution were studied by Neutron Depth Profiling (NDP). The photoluminescence spectra of the samples were measured to determine whether the emission was in the desired region of 1.5 μm. The obtained data made it possible to reveal the relations between the structural changes of erbium-implanted lithium niobate and its luminescence properties important for photonics applications.     

离子束辐照甜叶菊种子的当代生物学效应

本文用20keVN+离子束处理甜叶菊种子,注量分别为100×2500、400×2500和1000×2500N+/cm2,研究不同注量下甜叶菊种子发芽势以及发芽率的变化情况,并分析各处理组间差异。经统计分析,不同注量的甜叶菊种子发芽势和发芽率在α=0.05水平上差异显著。结果表明,随注量增大,发芽势和发芽率均呈先升后降趋势;注量为400×2500N+/cm2时,发芽势和发芽率达最高。     

氮离子注入生物絮凝剂产生菌的诱变效应研究

采用30 keV氮离子注入对生物絮凝剂产生菌进行诱变选育,研究低能氮离子对微生物的诱变效应.结果表明:FJ-7 菌株的存活率曲线为典型的"马鞍型"剂量.效应曲线.经5x1015 ions·cm-2 N 注入诱变处理,最终获得一株絮凝活性高、遗传稳定性良好的突变株NIM-192.其发酵产絮凝剂曲线表明,突变株NIM-192的菌体生长速度稍慢于原始菌株,但其絮凝活性一直高于原始菌株,絮凝率比原始菌株提高了34.26%.这很可能是离子注入菌体后所产生的生物学效应使得菌体合成更多的絮凝剂,导致絮凝活性的增强.     

Secondary ion emission from beryllium surfaces by Ar and /or (Ar+D2) mixed ion bombardments

With respect to the impurity emission and erosion of a Be first wall, a secondary ion mass spectrometric investigation was carried out along with surface characterization with X-ray photoelectron spectroscopy. It was found that Be is emitted as distinct types of chemical forms from the surface owing to sputtering with Ar⁺ and an (Ar⁺+ D⁺₂) mixture: (i) Be and Be-cluster, (ii) oxide and hydroxide, and (iii) hydride and/or deuteride.     

N+离子注入阿维拉霉素产生菌诱变效应的研究

选用低能(30keV)N 离子注入阿维拉霉素产生菌SV 56,研究其诱变效应.试验结果表明:SV-56菌株存活率曲线是典型的"马鞍型"剂量-效应曲线,"马鞍型"区域内具有高的正突变率(20.9%-26.2%).通过5×1015cm-2N 注入诱变处理、链霉素抗性筛选,最终获得一株稳定性良好、阿维拉霉素产量稳定在79.6-82.9 mg·L-1之间、较出发菌株提高41.4%-47.2%的突变株SVN-116.     

低能离子注入和UV照射白色链霉菌的生物学效应

低能离子注入和UV辐射经真空处理的白色链霉菌均表现出了复杂的生物学效应。探讨了低能离子注入白色链霉菌产生的“马鞍型”注量效应曲线的形成原因。实验结果表明真空因素不是“马鞍型”注量效应曲线形成的原因，推测“马鞍型”注量效应曲线是低剂量辐射产生的HRS／IRR效应。低剂量UV辐照经真空处理的白色链霉菌仪能表现出IRR效应，同时也表现出兴奋效应（存活率〉100％）。以抗链霉素突变为指标研究低能离子注入和UV辐射白色链霉菌的诱变效果的结果表明，UV是致白色链霉菌产生抗链霉素突变的有效手段。     

Effects of neutron-induced ion implantation into blanket structural materials

The high flux of energetic neutrons in CTR blankets will lead to an appreciable implantation of light particles in structural materials as a consequence of neutron impacts. The influence of implanted helium and lithium on the material properties of CTR structural materials should be known because both media are prospective coolants. 30keV lithium ions were implanted into pre-thinned Nb foils. Electron micrographs showed black dots which were identified as precipitates of Li. A concentration profile of He in Nb, which suitably simulates the implantation profile in CTR's, was obtained with the help of the ¹⁰B(n, α)⁷Li reaction. Nb samples which were irradiated up to a He dose of 6 × 10¹⁶ cm^?2 showed heavily damaged surfaces after annealing. Surface erosion of CTR blanket materials due to this process cannot be excluded.     

Angular distribution of Ag atoms sputtered with A 5 keV Ar+ ion beam

A polycrystalline, high-purity Ag target was sputtered with a normally incident, 5 keV Ar⁺ ion beam under ultrahigh vacuum (UHV) conditions. Sputtered material was collected on a cylindrically shaped Al foil and subsequently analysed in an Auger electron spectrometer. The obtained results show that sputtering under UHV conditions leads to a cosine-like distribution. The distribution taken after prolonged ion bombardment contained a hump at angles of 30–45° superimposed on the general form which we ascribe to an ion beam-induced texturing effect. The results are compared with recent investigations of other authors. The influence of the surface conditions of both the target and the foil used for collection of the sputtered material on the angular distribution measurements has also been investigated.