Bubble propagation by disks formed by ion-implantation

The investigation of implantation conditions for bubble propagation points to the necessity for a minimum dose (1.5 times 10^{16}ions cm²) and a sufficiently thick profile (0.4 μ). The use of flat profiles gives uniform implanted layers and allows values of the maximum defect concentration far away from the amorphization threshold. Unlike in permalloy circuits, bubble stability and bias field margins do not increase with the drive field. The propagation is not critically dependent upon disk diameter and spacing.     

Controlled silver delivery by silver-cellulose nanocomposites prepared by a one-pot green synthesis assisted by microwaves

Controlled silver release from cellulosic nanocomposites was achieved by synthesizing silver nanoparticles, under microwave heating for 1-15 min, in a one-pot, versatile and sustainable process in which microcrystalline cellulose simultaneously functions as reducing, stabilizing and supporting agent in water; chitin, starch and other cellulose derivatives could also be used as reducing, stabilizing and supporting agents for silver nanoparticles and the method was also found to be extensible to the preparation of noble metal (Au, Pt) and metal oxide nanoparticle (ZnO, Cu, CuO and Cu(2)O) nanocomposites.     

用数字说话 以实力证明——访中国质量认证中心主任王克娇

中国质量认证中心(CQC)是我国唯一加入IECEE-CB体系的国家认证机构(NCB)。时值我国加入IECEE-CB体系20年、颁发CB测试证书突破20000张之际,本刊记者独家专访CQC主任王克娇,请她谈谈CB进入中国20年来取得的骄人业绩,以及今后的发展计划。记者:王主任,在我国加入CB体系过程中,您参与了我国CB体系从发展到辉煌的整个过程。您能和我们分享一下这段珍贵的历史吗?王克娇:1985年,中国电工产品认证委员会(CCEE)代     

杜比认证的电影红光还音

本文简要地介绍了杜比实验室对我国电影红光还音读出器和放映机的技术测试、技术认证。杜比实验室的认证工作保证了我国电影红光还音的技术质量 ,促进了我国电影红光还音能规范地、顺利地向前发展     

Process tomography system by electrostatic charge carried by particles

Two methods, the back-projection (BP) method and the least-squares (LS) method, were applied to the electrodynamic tomography system. Electrostatic charges were assumed to exist in the sensing zone, and their images were reconstructed using these methods. The reconstructed images were compared with the original ones. The BP method is accurate in detecting the position of the electrostatic charge and is capable of detecting the size of the object. The BP method could not distinguish two charges at separate points in the sensing zone. The LS method could differentiate two points of charge, but the reconstructed images were of poor quality due to the large pixel size. A reconstruction algorithm combining the two methods produced better results.     

Photoresist removal process by hydrogen radicals generated by W catalyst

Hydrogen radical process for photoresist removal by use of hot W catalyst has been investigated for a possible application to advanced Cu/low-k dielectric interconnects in LSI. It is found that etching rates of resists depend critically on sample temperature (T_s) and are higher than 1 μm/min at the optimized condition. H radical irradiation effects on porous methylsilsesquioxane (p-MSQ) have been studied from measurements of k value and capacitance of the advanced interconnect test sample. No radical process is observed to induce the increase in k value of p-MSQ films. These results suggest that the hydrogen radical process for resist removal with W catalyst is promising for production of advanced interconnects.     

Hydrogen trapping by defects in semiconductors studied by anelastic spectroscopy

We review some results obtained by anelastic spectroscopy on H-related defects in III–V semiconductors. Anelastic measurements on InP lead to the formulation of a model explaining the conversion to the semi-insulating (SI) state. Moreover, in GaAs:Zn an extraordinarily fast relaxation rate has been measured and a possible explanation has been suggested. This results are reviewed and discussed in the light of new experiments on InP:Zn, whose spectrum shows a relaxation process similar to the one in GaAs:Zn.     

依次放松约束结点的子结构法

子结构法是大型结构体系分析的有效方法之一。本文推荐一种依次放松约束结点的子结构法,对利用此法和 FORTRAN 语言编写的分析平面框架的计算机程序 APRFUS 作了简要介绍,对结构划分的注意事项作了说明。本文建议的方法,特别适合于用小型计算机分析平面框架和塔架一类结构。     

Nb3Si prepared by high-rate sputtering followed by quenching

Nb₃Si films with the A-15 structure have been prepared by sputtering onto a substrate whose temperature is about 1000 C, followed by quenching to liquid nitrogen temperature. All processes were carried out by using magnetron sputtering in a container full of liquid nitrogen. The quenching just after the deposition was achieved by thermal conduction using a sample holder in contact with the liquid nitrogen container. The highest onset temperature T _on and critical temperature (midpoint of the transition) T _c of the samples are 17.3 and 16.4 K, respectively, with a sharp transition. X-ray diffraction patterns show fine-grained A-15 structure and give a lattice constant of 5.09 Å.Work supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education.     

Development by Hydrazine

The reduction of silver bromide in alkaline solution by hydrozine yields four atoms of silver per molecule of hydrazine. Development of a (lne-grain bromide emulsion takes place at pH levels obove 12 at a rate proportional to the concentration of hydrazine and to the hydroxyl ion concentrotion. The (lrst and rate-determining step is the loss of a single hydrogen ion and an electron from the hydrozine. The density-time plots are sigmoid with a deep toe curvature. E/ectronmicrographs of the developed particle population ot various stages show that the density grows by the increase in the number af centres reaching the developable stage.     

Healthy by choice

How can physical scientists contribute to biomedical applications and healthcare?